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linux-stable/Documentation/filesystems/locking.rst

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docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
=======
Locking
=======
The text below describes the locking rules for VFS-related methods.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
It is (believed to be) up-to-date. *Please*, if you change anything in
prototypes or locking protocols - update this file. And update the relevant
instances in the tree, don't leave that to maintainers of filesystems/devices/
etc. At the very least, put the list of dubious cases in the end of this file.
Don't turn it into log - maintainers of out-of-the-tree code are supposed to
be able to use diff(1).
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
Thing currently missing here: socket operations. Alexey?
dentry_operations
=================
prototypes::
stop passing nameidata * to ->d_revalidate() Just the lookup flags. Die, bastard, die... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-10 20:03:43 +00:00
int (*d_revalidate)(struct dentry *, unsigned int);
vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op The following set of operations on a NFS client and server will cause server# mkdir a client# cd a server# mv a a.bak client# sleep 30 # (or whatever the dir attrcache timeout is) client# stat . stat: cannot stat `.': Stale NFS file handle Obviously, we should not be getting an ESTALE error back there since the inode still exists on the server. The problem is that the lookup code will call d_revalidate on the dentry that "." refers to, because NFS has FS_REVAL_DOT set. nfs_lookup_revalidate will see that the parent directory has changed and will try to reverify the dentry by redoing a LOOKUP. That of course fails, so the lookup code returns ESTALE. The problem here is that d_revalidate is really a bad fit for this case. What we really want to know at this point is whether the inode is still good or not, but we don't really care what name it goes by or whether the dcache is still valid. Add a new d_op->d_weak_revalidate operation and have complete_walk call that instead of d_revalidate. The intent there is to allow for a "weaker" d_revalidate that just checks to see whether the inode is still good. This is also gives us an opportunity to kill off the FS_REVAL_DOT special casing. [AV: changed method name, added note in porting, fixed confusion re having it possibly called from RCU mode (it won't be)] Cc: NeilBrown <neilb@suse.de> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-20 16:19:05 +00:00
int (*d_weak_revalidate)(struct dentry *, unsigned int);
Don't pass inode to ->d_hash() and ->d_compare() Instances either don't look at it at all (the majority of cases) or only want it to find the superblock (which can be had as dentry->d_sb). A few cases that want more are actually safe with dentry->d_inode - the only precaution needed is the check that it hadn't been replaced with NULL by rmdir() or by overwriting rename(), which case should be simply treated as cache miss. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-21 22:22:44 +00:00
int (*d_hash)(const struct dentry *, struct qstr *);
get rid of 'parent' argument of ->d_compare() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-31 20:37:25 +00:00
int (*d_compare)(const struct dentry *,
fs: change d_compare for rcu-walk Change d_compare so it may be called from lock-free RCU lookups. This does put significant restrictions on what may be done from the callback, however there don't seem to have been any problems with in-tree fses. If some strange use case pops up that _really_ cannot cope with the rcu-walk rules, we can just add new rcu-unaware callbacks, which would cause name lookup to drop out of rcu-walk mode. For in-tree filesystems, this is just a mechanical change. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 06:49:27 +00:00
unsigned int, const char *, const struct qstr *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*d_delete)(struct dentry *);
vfs: new d_init method Allow filesystem to initialize dentry at allocation time. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-28 09:47:32 +00:00
int (*d_init)(struct dentry *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
VFS: delay the dentry name generation on sockets and pipes 1) Introduces a new method in 'struct dentry_operations'. This method called d_dname() might be called from d_path() to build a pathname for special filesystems. It is called without locks. Future patches (if we succeed in having one common dentry for all pipes/sockets) may need to change prototype of this method, but we now use : char *d_dname(struct dentry *dentry, char *buffer, int buflen); 2) Adds a dynamic_dname() helper function that eases d_dname() implementations 3) Defines d_dname method for sockets : No more sprintf() at socket creation. This is delayed up to the moment someone does an access to /proc/pid/fd/... 4) Defines d_dname method for pipes : No more sprintf() at pipe creation. This is delayed up to the moment someone does an access to /proc/pid/fd/... A benchmark consisting of 1.000.000 calls to pipe()/close()/close() gives a *nice* speedup on my Pentium(M) 1.6 Ghz : 3.090 s instead of 3.450 s Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Acked-by: Christoph Hellwig <hch@infradead.org> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-08 07:26:18 +00:00
char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
Add a dentry op to handle automounting rather than abusing follow_link() Add a dentry op (d_automount) to handle automounting directories rather than abusing the follow_link() inode operation. The operation is keyed off a new dentry flag (DCACHE_NEED_AUTOMOUNT). This also makes it easier to add an AT_ flag to suppress terminal segment automount during pathwalk and removes the need for the kludge code in the pathwalk algorithm to handle directories with follow_link() semantics. The ->d_automount() dentry operation: struct vfsmount *(*d_automount)(struct path *mountpoint); takes a pointer to the directory to be mounted upon, which is expected to provide sufficient data to determine what should be mounted. If successful, it should return the vfsmount struct it creates (which it should also have added to the namespace using do_add_mount() or similar). If there's a collision with another automount attempt, NULL should be returned. If the directory specified by the parameter should be used directly rather than being mounted upon, -EISDIR should be returned. In any other case, an error code should be returned. The ->d_automount() operation is called with no locks held and may sleep. At this point the pathwalk algorithm will be in ref-walk mode. Within fs/namei.c itself, a new pathwalk subroutine (follow_automount()) is added to handle mountpoints. It will return -EREMOTE if the automount flag was set, but no d_automount() op was supplied, -ELOOP if we've encountered too many symlinks or mountpoints, -EISDIR if the walk point should be used without mounting and 0 if successful. The path will be updated to point to the mounted filesystem if a successful automount took place. __follow_mount() is replaced by follow_managed() which is more generic (especially with the patch that adds ->d_manage()). This handles transits from directories during pathwalk, including automounting and skipping over mountpoints (and holding processes with the next patch). __follow_mount_rcu() will jump out of RCU-walk mode if it encounters an automount point with nothing mounted on it. follow_dotdot*() does not handle automounts as you don't want to trigger them whilst following "..". I've also extracted the mount/don't-mount logic from autofs4 and included it here. It makes the mount go ahead anyway if someone calls open() or creat(), tries to traverse the directory, tries to chdir/chroot/etc. into the directory, or sticks a '/' on the end of the pathname. If they do a stat(), however, they'll only trigger the automount if they didn't also say O_NOFOLLOW. I've also added an inode flag (S_AUTOMOUNT) so that filesystems can mark their inodes as automount points. This flag is automatically propagated to the dentry as DCACHE_NEED_AUTOMOUNT by __d_instantiate(). This saves NFS and could save AFS a private flag bit apiece, but is not strictly necessary. It would be preferable to do the propagation in d_set_d_op(), but that doesn't normally have access to the inode. [AV: fixed breakage in case if __follow_mount_rcu() fails and nameidata_drop_rcu() succeeds in RCU case of do_lookup(); we need to fall through to non-RCU case after that, rather than just returning with ungrabbed *path] Signed-off-by: David Howells <dhowells@redhat.com> Was-Acked-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-14 18:45:21 +00:00
struct vfsmount *(*d_automount)(struct path *path);
vfs: change d_manage() to take a struct path For the autofs module to be able to reliably check if a dentry is a mountpoint in a multiple namespace environment the ->d_manage() dentry operation will need to take a path argument instead of a dentry. Link: http://lkml.kernel.org/r/20161011053352.27645.83962.stgit@pluto.themaw.net Signed-off-by: Ian Kent <raven@themaw.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Omar Sandoval <osandov@osandov.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-11-23 21:03:41 +00:00
int (*d_manage)(const struct path *, bool);
fs: remove the inode argument to ->d_real() method The only remaining user of ->d_real() method is d_real_inode(), which passed NULL inode argument to get the real data dentry. There are no longer any users that call ->d_real() with a non-NULL inode argument for getting a detry from a specific underlying layer. Remove the inode argument of the method and replace it with an integer 'type' argument, to allow callers to request the real metadata dentry instead of the real data dentry. All the current users of d_real_inode() (e.g. uprobe) continue to get the real data inode. Caller that need to get the real metadata inode (e.g. IMA/EVM) can use d_inode(d_real(dentry, D_REAL_METADATA)). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Link: https://lore.kernel.org/r/20240202110132.1584111-3-amir73il@gmail.com Tested-by: Stefan Berger <stefanb@linux.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-02-02 11:01:32 +00:00
struct dentry *(*d_real)(struct dentry *, enum d_real_type type);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locking rules:
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
================== =========== ======== ============== ========
ops rename_lock ->d_lock may block rcu-walk
================== =========== ======== ============== ========
d_revalidate: no no yes (ref-walk) maybe
d_weak_revalidate: no no yes no
d_hash no no no maybe
d_compare: yes no no maybe
d_delete: no yes no no
d_init: no no yes no
d_release: no no yes no
d_prune: no yes no no
d_iput: no no yes no
d_dname: no no no no
d_automount: no no yes no
d_manage: no no yes (ref-walk) maybe
d_real no no yes no
================== =========== ======== ============== ========
inode_operations
================
prototypes::
fs: port ->create() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:13 +00:00
int (*create) (struct mnt_idmap *, struct inode *,struct dentry *,umode_t, bool);
stop passing nameidata to ->lookup() Just the flags; only NFS cares even about that, but there are legitimate uses for such argument. And getting rid of that completely would require splitting ->lookup() into a couple of methods (at least), so let's leave that alone for now... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-10 21:13:09 +00:00
struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*link) (struct dentry *,struct inode *,struct dentry *);
int (*unlink) (struct inode *,struct dentry *);
fs: port ->symlink() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:14 +00:00
int (*symlink) (struct mnt_idmap *, struct inode *,struct dentry *,const char *);
fs: port ->mkdir() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:15 +00:00
int (*mkdir) (struct mnt_idmap *, struct inode *,struct dentry *,umode_t);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*rmdir) (struct inode *,struct dentry *);
fs: port ->mknod() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:16 +00:00
int (*mknod) (struct mnt_idmap *, struct inode *,struct dentry *,umode_t,dev_t);
fs: port ->rename() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:17 +00:00
int (*rename) (struct mnt_idmap *, struct inode *, struct dentry *,
vfs: add renameat2 syscall Add new renameat2 syscall, which is the same as renameat with an added flags argument. Pass flags to vfs_rename() and to i_op->rename() as well. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 15:08:42 +00:00
struct inode *, struct dentry *, unsigned int);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*readlink) (struct dentry *, char __user *,int);
Documentation/filesystems/Locking: fix ->get_link() prototype Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-11 23:16:29 +00:00
const char *(*get_link) (struct dentry *, struct inode *, struct delayed_call *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void (*truncate) (struct inode *);
fs: port ->permission() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:22 +00:00
int (*permission) (struct mnt_idmap *, struct inode *, int, unsigned int);
fs: rename current get acl method The current way of setting and getting posix acls through the generic xattr interface is error prone and type unsafe. The vfs needs to interpret and fixup posix acls before storing or reporting it to userspace. Various hacks exist to make this work. The code is hard to understand and difficult to maintain in it's current form. Instead of making this work by hacking posix acls through xattr handlers we are building a dedicated posix acl api around the get and set inode operations. This removes a lot of hackiness and makes the codepaths easier to maintain. A lot of background can be found in [1]. The current inode operation for getting posix acls takes an inode argument but various filesystems (e.g., 9p, cifs, overlayfs) need access to the dentry. In contrast to the ->set_acl() inode operation we cannot simply extend ->get_acl() to take a dentry argument. The ->get_acl() inode operation is called from: acl_permission_check() -> check_acl() -> get_acl() which is part of generic_permission() which in turn is part of inode_permission(). Both generic_permission() and inode_permission() are called in the ->permission() handler of various filesystems (e.g., overlayfs). So simply passing a dentry argument to ->get_acl() would amount to also having to pass a dentry argument to ->permission(). We should avoid this unnecessary change. So instead of extending the existing inode operation rename it from ->get_acl() to ->get_inode_acl() and add a ->get_acl() method later that passes a dentry argument and which filesystems that need access to the dentry can implement instead of ->get_inode_acl(). Filesystems like cifs which allow setting and getting posix acls but not using them for permission checking during lookup can simply not implement ->get_inode_acl(). This is intended to be a non-functional change. Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1] Suggested-by/Inspired-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-09-22 15:17:00 +00:00
struct posix_acl * (*get_inode_acl)(struct inode *, int, bool);
fs: port ->setattr() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:11 +00:00
int (*setattr) (struct mnt_idmap *, struct dentry *, struct iattr *);
fs: port ->getattr() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:12 +00:00
int (*getattr) (struct mnt_idmap *, const struct path *, struct kstat *, u32, unsigned int);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
ssize_t (*listxattr) (struct dentry *, char *, size_t);
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start, u64 len);
fs: introduce inode operation ->update_time Btrfs has to make sure we have space to allocate new blocks in order to modify the inode, so updating time can fail. We've gotten around this by having our own file_update_time but this is kind of a pain, and Christoph has indicated he would like to make xfs do something different with atime updates. So introduce ->update_time, where we will deal with i_version an a/m/c time updates and indicate which changes need to be made. The normal version just does what it has always done, updates the time and marks the inode dirty, and then filesystems can choose to do something different. I've gone through all of the users of file_update_time and made them check for errors with the exception of the fault code since it's complicated and I wasn't quite sure what to do there, also Jan is going to be pushing the file time updates into page_mkwrite for those who have it so that should satisfy btrfs and make it not a big deal to check the file_update_time() return code in the generic fault path. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2012-03-26 13:59:21 +00:00
void (*update_time)(struct inode *, struct timespec *, int);
make ->atomic_open() return int Change of calling conventions: old new NULL 1 file 0 ERR_PTR(-ve) -ve Caller *knows* that struct file *; no need to return it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-22 08:39:14 +00:00
int (*atomic_open)(struct inode *, struct dentry *,
kill struct opendata Just pass struct file *. Methods are happier that way... There's no need to return struct file * from finish_open() now, so let it return int. Next: saner prototypes for parts in namei.c Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-22 08:40:19 +00:00
struct file *, unsigned open_flag,
document ->atomic_open() changes Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-07-09 23:20:08 +00:00
umode_t create_mode);
fs: port ->tmpfile() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:18 +00:00
int (*tmpfile) (struct mnt_idmap *, struct inode *,
vfs: open inside ->tmpfile() This is in preparation for adding tmpfile support to fuse, which requires that the tmpfile creation and opening are done as a single operation. Replace the 'struct dentry *' argument of i_op->tmpfile with 'struct file *'. Call finish_open_simple() as the last thing in ->tmpfile() instances (may be omitted in the error case). Change d_tmpfile() argument to 'struct file *' as well to make callers more readable. Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2022-09-24 05:00:00 +00:00
struct file *, umode_t);
fs: port ->fileattr_set() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:21 +00:00
int (*fileattr_set)(struct mnt_idmap *idmap,
vfs: add fileattr ops There's a substantial amount of boilerplate in filesystems handling FS_IOC_[GS]ETFLAGS/ FS_IOC_FS[GS]ETXATTR ioctls. Also due to userspace buffers being involved in the ioctl API this is difficult to stack, as shown by overlayfs issues related to these ioctls. Introduce a new internal API named "fileattr" (fsxattr can be confused with xattr, xflags is inappropriate, since this is more than just flags). There's significant overlap between flags and xflags and this API handles the conversions automatically, so filesystems may choose which one to use. In ->fileattr_get() a hint is provided to the filesystem whether flags or xattr are being requested by userspace, but in this series this hint is ignored by all filesystems, since generating all the attributes is cheap. If a filesystem doesn't implemement the fileattr API, just fall back to f_op->ioctl(). When all filesystems are converted, the fallback can be removed. 32bit compat ioctls are now handled by the generic code as well. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-07 12:36:42 +00:00
struct dentry *dentry, struct fileattr *fa);
int (*fileattr_get)(struct dentry *dentry, struct fileattr *fa);
fs: port ->get_acl() to pass mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:19 +00:00
struct posix_acl * (*get_acl)(struct mnt_idmap *, struct dentry *, int);
libfs: Add directory operations for stable offsets Create a vector of directory operations in fs/libfs.c that handles directory seeks and readdir via stable offsets instead of the current cursor-based mechanism. For the moment these are unused. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Message-Id: <168814732984.530310.11190772066786107220.stgit@manet.1015granger.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-30 17:48:49 +00:00
struct offset_ctx *(*get_offset_ctx)(struct inode *inode);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locking rules:
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
all may block
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
libfs: Add directory operations for stable offsets Create a vector of directory operations in fs/libfs.c that handles directory seeks and readdir via stable offsets instead of the current cursor-based mechanism. For the moment these are unused. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Message-Id: <168814732984.530310.11190772066786107220.stgit@manet.1015granger.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-30 17:48:49 +00:00
============== ==================================================
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
ops i_rwsem(inode)
libfs: Add directory operations for stable offsets Create a vector of directory operations in fs/libfs.c that handles directory seeks and readdir via stable offsets instead of the current cursor-based mechanism. For the moment these are unused. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Message-Id: <168814732984.530310.11190772066786107220.stgit@manet.1015granger.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-30 17:48:49 +00:00
============== ==================================================
Documentation: filesystems: update filesystem locking documentation Documentation/filesystems/Locking no longer reflects current locking semantics. i_mutex is no longer used for locking, and has been superseded by i_rwsem. Additionally, ->iterate_shared() was not documented. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-24 02:29:10 +00:00
lookup: shared
create: exclusive
link: exclusive (both)
mknod: exclusive
symlink: exclusive
mkdir: exclusive
unlink: exclusive (both)
rmdir: exclusive (both)(see below)
rename(): fix the locking of subdirectories We should never lock two subdirectories without having taken ->s_vfs_rename_mutex; inode pointer order or not, the "order" proposed in 28eceeda130f "fs: Lock moved directories" is not transitive, with the usual consequences. The rationale for locking renamed subdirectory in all cases was the possibility of race between rename modifying .. in a subdirectory to reflect the new parent and another thread modifying the same subdirectory. For a lot of filesystems that's not a problem, but for some it can lead to trouble (e.g. the case when short directory contents is kept in the inode, but creating a file in it might push it across the size limit and copy its contents into separate data block(s)). However, we need that only in case when the parent does change - otherwise ->rename() doesn't need to do anything with .. entry in the first place. Some instances are lazy and do a tautological update anyway, but it's really not hard to avoid. Amended locking rules for rename(): find the parent(s) of source and target if source and target have the same parent lock the common parent else lock ->s_vfs_rename_mutex lock both parents, in ancestor-first order; if neither is an ancestor of another, lock the parent of source first. find the source and target. if source and target have the same parent if operation is an overwriting rename of a subdirectory lock the target subdirectory else if source is a subdirectory lock the source if target is a subdirectory lock the target lock non-directories involved, in inode pointer order if both source and target are such. That way we are guaranteed that parents are locked (for obvious reasons), that any renamed non-directory is locked (nfsd relies upon that), that any victim is locked (emptiness check needs that, among other things) and subdirectory that changes parent is locked (needed to protect the update of .. entries). We are also guaranteed that any operation locking more than one directory either takes ->s_vfs_rename_mutex or locks a parent followed by its child. Cc: stable@vger.kernel.org Fixes: 28eceeda130f "fs: Lock moved directories" Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-11-20 01:25:58 +00:00
rename: exclusive (both parents, some children) (see below)
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
readlink: no
replace ->follow_link() with new method that could stay in RCU mode new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-17 15:20:54 +00:00
get_link: no
Documentation: filesystems: update filesystem locking documentation Documentation/filesystems/Locking no longer reflects current locking semantics. i_mutex is no longer used for locking, and has been superseded by i_rwsem. Additionally, ->iterate_shared() was not documented. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-24 02:29:10 +00:00
setattr: exclusive
fs: provide rcu-walk aware permission i_ops Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 06:49:58 +00:00
permission: no (may not block if called in rcu-walk mode)
fs: rename current get acl method The current way of setting and getting posix acls through the generic xattr interface is error prone and type unsafe. The vfs needs to interpret and fixup posix acls before storing or reporting it to userspace. Various hacks exist to make this work. The code is hard to understand and difficult to maintain in it's current form. Instead of making this work by hacking posix acls through xattr handlers we are building a dedicated posix acl api around the get and set inode operations. This removes a lot of hackiness and makes the codepaths easier to maintain. A lot of background can be found in [1]. The current inode operation for getting posix acls takes an inode argument but various filesystems (e.g., 9p, cifs, overlayfs) need access to the dentry. In contrast to the ->set_acl() inode operation we cannot simply extend ->get_acl() to take a dentry argument. The ->get_acl() inode operation is called from: acl_permission_check() -> check_acl() -> get_acl() which is part of generic_permission() which in turn is part of inode_permission(). Both generic_permission() and inode_permission() are called in the ->permission() handler of various filesystems (e.g., overlayfs). So simply passing a dentry argument to ->get_acl() would amount to also having to pass a dentry argument to ->permission(). We should avoid this unnecessary change. So instead of extending the existing inode operation rename it from ->get_acl() to ->get_inode_acl() and add a ->get_acl() method later that passes a dentry argument and which filesystems that need access to the dentry can implement instead of ->get_inode_acl(). Filesystems like cifs which allow setting and getting posix acls but not using them for permission checking during lookup can simply not implement ->get_inode_acl(). This is intended to be a non-functional change. Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1] Suggested-by/Inspired-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-09-22 15:17:00 +00:00
get_inode_acl: no
fs: add new get acl method The current way of setting and getting posix acls through the generic xattr interface is error prone and type unsafe. The vfs needs to interpret and fixup posix acls before storing or reporting it to userspace. Various hacks exist to make this work. The code is hard to understand and difficult to maintain in it's current form. Instead of making this work by hacking posix acls through xattr handlers we are building a dedicated posix acl api around the get and set inode operations. This removes a lot of hackiness and makes the codepaths easier to maintain. A lot of background can be found in [1]. Since some filesystem rely on the dentry being available to them when setting posix acls (e.g., 9p and cifs) they cannot rely on the old get acl inode operation to retrieve posix acl and need to implement their own custom handlers because of that. In a previous patch we renamed the old get acl inode operation to ->get_inode_acl(). We decided to rename it and implement a new one since ->get_inode_acl() is called generic_permission() and inode_permission() both of which can be called during an filesystem's ->permission() handler. So simply passing a dentry argument to ->get_acl() would have amounted to also having to pass a dentry argument to ->permission(). We avoided that change. This adds a new ->get_acl() inode operations which takes a dentry argument which filesystems such as 9p, cifs, and overlayfs can implement to get posix acls. Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1] Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-09-22 15:17:01 +00:00
get_acl: no
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
getattr: no
listxattr: no
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
fiemap: no
fs: introduce inode operation ->update_time Btrfs has to make sure we have space to allocate new blocks in order to modify the inode, so updating time can fail. We've gotten around this by having our own file_update_time but this is kind of a pain, and Christoph has indicated he would like to make xfs do something different with atime updates. So introduce ->update_time, where we will deal with i_version an a/m/c time updates and indicate which changes need to be made. The normal version just does what it has always done, updates the time and marks the inode dirty, and then filesystems can choose to do something different. I've gone through all of the users of file_update_time and made them check for errors with the exception of the fault code since it's complicated and I wasn't quite sure what to do there, also Jan is going to be pushing the file time updates into page_mkwrite for those who have it so that should satisfy btrfs and make it not a big deal to check the file_update_time() return code in the generic fault path. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2012-03-26 13:59:21 +00:00
update_time: no
Documentation: atomic_open called with shared lock on non-O_CREAT open The exclusive lock is only held when O_CREAT is set. Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-10-30 10:46:54 +00:00
atomic_open: shared (exclusive if O_CREAT is set in open flags)
Document ->tmpfile() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-03 12:19:23 +00:00
tmpfile: no
vfs: add fileattr ops There's a substantial amount of boilerplate in filesystems handling FS_IOC_[GS]ETFLAGS/ FS_IOC_FS[GS]ETXATTR ioctls. Also due to userspace buffers being involved in the ioctl API this is difficult to stack, as shown by overlayfs issues related to these ioctls. Introduce a new internal API named "fileattr" (fsxattr can be confused with xattr, xflags is inappropriate, since this is more than just flags). There's significant overlap between flags and xflags and this API handles the conversions automatically, so filesystems may choose which one to use. In ->fileattr_get() a hint is provided to the filesystem whether flags or xattr are being requested by userspace, but in this series this hint is ignored by all filesystems, since generating all the attributes is cheap. If a filesystem doesn't implemement the fileattr API, just fall back to f_op->ioctl(). When all filesystems are converted, the fallback can be removed. 32bit compat ioctls are now handled by the generic code as well. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-04-07 12:36:42 +00:00
fileattr_get: no or exclusive
fileattr_set: exclusive
libfs: Add directory operations for stable offsets Create a vector of directory operations in fs/libfs.c that handles directory seeks and readdir via stable offsets instead of the current cursor-based mechanism. For the moment these are unused. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Message-Id: <168814732984.530310.11190772066786107220.stgit@manet.1015granger.net> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-06-30 17:48:49 +00:00
get_offset_ctx no
============== ==================================================
fs: introduce inode operation ->update_time Btrfs has to make sure we have space to allocate new blocks in order to modify the inode, so updating time can fail. We've gotten around this by having our own file_update_time but this is kind of a pain, and Christoph has indicated he would like to make xfs do something different with atime updates. So introduce ->update_time, where we will deal with i_version an a/m/c time updates and indicate which changes need to be made. The normal version just does what it has always done, updates the time and marks the inode dirty, and then filesystems can choose to do something different. I've gone through all of the users of file_update_time and made them check for errors with the exception of the fault code since it's complicated and I wasn't quite sure what to do there, also Jan is going to be pushing the file time updates into page_mkwrite for those who have it so that should satisfy btrfs and make it not a big deal to check the file_update_time() return code in the generic fault path. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2012-03-26 13:59:21 +00:00
xattr: Stop calling {get,set,remove}xattr inode operations All filesystems that support xattrs by now do so via xattr handlers. They all define sb->s_xattr, and their getxattr, setxattr, and removexattr inode operations use the generic inode operations. On filesystems that don't support xattrs, the xattr inode operations are all NULL, and sb->s_xattr is also NULL. This means that we can remove the getxattr, setxattr, and removexattr inode operations and directly call the generic handlers, or better, inline expand those handlers into fs/xattr.c. Filesystems that do not support xattrs on some inodes should clear the IOP_XATTR i_opflags flag in those inodes. (Right now, some filesystems have checks to disable xattrs on some inodes in the ->list, ->get, and ->set xattr handler operations instead.) The IOP_XATTR flag is automatically cleared in inodes of filesystems that don't have xattr support. In orangefs, symlinks do have a setxattr iop but no getxattr iop. Add a check for symlinks to orangefs_inode_getxattr to preserve the current, weird behavior; that check may not be necessary though. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-29 15:48:44 +00:00
Documentation: filesystems: update filesystem locking documentation Documentation/filesystems/Locking no longer reflects current locking semantics. i_mutex is no longer used for locking, and has been superseded by i_rwsem. Additionally, ->iterate_shared() was not documented. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-24 02:29:10 +00:00
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_rwsem
exclusive on victim.
fs: rename "rename2" i_op to "rename" Generated patch: sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2` sed -i "s/\brename2\b/rename/g" `git grep -wl rename2` Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-27 09:03:58 +00:00
cross-directory ->rename() has (per-superblock) ->s_vfs_rename_sem.
rename(): fix the locking of subdirectories We should never lock two subdirectories without having taken ->s_vfs_rename_mutex; inode pointer order or not, the "order" proposed in 28eceeda130f "fs: Lock moved directories" is not transitive, with the usual consequences. The rationale for locking renamed subdirectory in all cases was the possibility of race between rename modifying .. in a subdirectory to reflect the new parent and another thread modifying the same subdirectory. For a lot of filesystems that's not a problem, but for some it can lead to trouble (e.g. the case when short directory contents is kept in the inode, but creating a file in it might push it across the size limit and copy its contents into separate data block(s)). However, we need that only in case when the parent does change - otherwise ->rename() doesn't need to do anything with .. entry in the first place. Some instances are lazy and do a tautological update anyway, but it's really not hard to avoid. Amended locking rules for rename(): find the parent(s) of source and target if source and target have the same parent lock the common parent else lock ->s_vfs_rename_mutex lock both parents, in ancestor-first order; if neither is an ancestor of another, lock the parent of source first. find the source and target. if source and target have the same parent if operation is an overwriting rename of a subdirectory lock the target subdirectory else if source is a subdirectory lock the source if target is a subdirectory lock the target lock non-directories involved, in inode pointer order if both source and target are such. That way we are guaranteed that parents are locked (for obvious reasons), that any renamed non-directory is locked (nfsd relies upon that), that any victim is locked (emptiness check needs that, among other things) and subdirectory that changes parent is locked (needed to protect the update of .. entries). We are also guaranteed that any operation locking more than one directory either takes ->s_vfs_rename_mutex or locks a parent followed by its child. Cc: stable@vger.kernel.org Fixes: 28eceeda130f "fs: Lock moved directories" Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2023-11-20 01:25:58 +00:00
->unlink() and ->rename() have ->i_rwsem exclusive on all non-directories
involved.
->rename() has ->i_rwsem exclusive on any subdirectory that changes parent.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
See Documentation/filesystems/directory-locking.rst for more detailed discussion
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
of the locking scheme for directory operations.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
xattr_handler operations
========================
prototypes::
xattr: Stop calling {get,set,remove}xattr inode operations All filesystems that support xattrs by now do so via xattr handlers. They all define sb->s_xattr, and their getxattr, setxattr, and removexattr inode operations use the generic inode operations. On filesystems that don't support xattrs, the xattr inode operations are all NULL, and sb->s_xattr is also NULL. This means that we can remove the getxattr, setxattr, and removexattr inode operations and directly call the generic handlers, or better, inline expand those handlers into fs/xattr.c. Filesystems that do not support xattrs on some inodes should clear the IOP_XATTR i_opflags flag in those inodes. (Right now, some filesystems have checks to disable xattrs on some inodes in the ->list, ->get, and ->set xattr handler operations instead.) The IOP_XATTR flag is automatically cleared in inodes of filesystems that don't have xattr support. In orangefs, symlinks do have a setxattr iop but no getxattr iop. Add a check for symlinks to orangefs_inode_getxattr to preserve the current, weird behavior; that check may not be necessary though. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-29 15:48:44 +00:00
bool (*list)(struct dentry *dentry);
int (*get)(const struct xattr_handler *handler, struct dentry *dentry,
struct inode *inode, const char *name, void *buffer,
size_t size);
acl: handle idmapped mounts The posix acl permission checking helpers determine whether a caller is privileged over an inode according to the acls associated with the inode. Add helpers that make it possible to handle acls on idmapped mounts. The vfs and the filesystems targeted by this first iteration make use of posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to translate basic posix access and default permissions such as the ACL_USER and ACL_GROUP type according to the initial user namespace (or the superblock's user namespace) to and from the caller's current user namespace. Adapt these two helpers to handle idmapped mounts whereby we either map from or into the mount's user namespace depending on in which direction we're translating. Similarly, cap_convert_nscap() is used by the vfs to translate user namespace and non-user namespace aware filesystem capabilities from the superblock's user namespace to the caller's user namespace. Enable it to handle idmapped mounts by accounting for the mount's user namespace. In addition the fileystems targeted in the first iteration of this patch series make use of the posix_acl_chmod() and, posix_acl_update_mode() helpers. Both helpers perform permission checks on the target inode. Let them handle idmapped mounts. These two helpers are called when posix acls are set by the respective filesystems to handle this case we extend the ->set() method to take an additional user namespace argument to pass the mount's user namespace down. Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-21 13:19:27 +00:00
int (*set)(const struct xattr_handler *handler,
fs: port xattr to mnt_idmap Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2023-01-13 11:49:23 +00:00
struct mnt_idmap *idmap,
acl: handle idmapped mounts The posix acl permission checking helpers determine whether a caller is privileged over an inode according to the acls associated with the inode. Add helpers that make it possible to handle acls on idmapped mounts. The vfs and the filesystems targeted by this first iteration make use of posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to translate basic posix access and default permissions such as the ACL_USER and ACL_GROUP type according to the initial user namespace (or the superblock's user namespace) to and from the caller's current user namespace. Adapt these two helpers to handle idmapped mounts whereby we either map from or into the mount's user namespace depending on in which direction we're translating. Similarly, cap_convert_nscap() is used by the vfs to translate user namespace and non-user namespace aware filesystem capabilities from the superblock's user namespace to the caller's user namespace. Enable it to handle idmapped mounts by accounting for the mount's user namespace. In addition the fileystems targeted in the first iteration of this patch series make use of the posix_acl_chmod() and, posix_acl_update_mode() helpers. Both helpers perform permission checks on the target inode. Let them handle idmapped mounts. These two helpers are called when posix acls are set by the respective filesystems to handle this case we extend the ->set() method to take an additional user namespace argument to pass the mount's user namespace down. Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-21 13:19:27 +00:00
struct dentry *dentry, struct inode *inode, const char *name,
const void *buffer, size_t size, int flags);
xattr: Stop calling {get,set,remove}xattr inode operations All filesystems that support xattrs by now do so via xattr handlers. They all define sb->s_xattr, and their getxattr, setxattr, and removexattr inode operations use the generic inode operations. On filesystems that don't support xattrs, the xattr inode operations are all NULL, and sb->s_xattr is also NULL. This means that we can remove the getxattr, setxattr, and removexattr inode operations and directly call the generic handlers, or better, inline expand those handlers into fs/xattr.c. Filesystems that do not support xattrs on some inodes should clear the IOP_XATTR i_opflags flag in those inodes. (Right now, some filesystems have checks to disable xattrs on some inodes in the ->list, ->get, and ->set xattr handler operations instead.) The IOP_XATTR flag is automatically cleared in inodes of filesystems that don't have xattr support. In orangefs, symlinks do have a setxattr iop but no getxattr iop. Add a check for symlinks to orangefs_inode_getxattr to preserve the current, weird behavior; that check may not be necessary though. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-29 15:48:44 +00:00
locking rules:
all may block
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
===== ==============
ops i_rwsem(inode)
===== ==============
xattr: Stop calling {get,set,remove}xattr inode operations All filesystems that support xattrs by now do so via xattr handlers. They all define sb->s_xattr, and their getxattr, setxattr, and removexattr inode operations use the generic inode operations. On filesystems that don't support xattrs, the xattr inode operations are all NULL, and sb->s_xattr is also NULL. This means that we can remove the getxattr, setxattr, and removexattr inode operations and directly call the generic handlers, or better, inline expand those handlers into fs/xattr.c. Filesystems that do not support xattrs on some inodes should clear the IOP_XATTR i_opflags flag in those inodes. (Right now, some filesystems have checks to disable xattrs on some inodes in the ->list, ->get, and ->set xattr handler operations instead.) The IOP_XATTR flag is automatically cleared in inodes of filesystems that don't have xattr support. In orangefs, symlinks do have a setxattr iop but no getxattr iop. Add a check for symlinks to orangefs_inode_getxattr to preserve the current, weird behavior; that check may not be necessary though. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-29 15:48:44 +00:00
list: no
get: no
Documentation: filesystems: update filesystem locking documentation Documentation/filesystems/Locking no longer reflects current locking semantics. i_mutex is no longer used for locking, and has been superseded by i_rwsem. Additionally, ->iterate_shared() was not documented. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-24 02:29:10 +00:00
set: exclusive
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
===== ==============
super_operations
================
prototypes::
xattr: Stop calling {get,set,remove}xattr inode operations All filesystems that support xattrs by now do so via xattr handlers. They all define sb->s_xattr, and their getxattr, setxattr, and removexattr inode operations use the generic inode operations. On filesystems that don't support xattrs, the xattr inode operations are all NULL, and sb->s_xattr is also NULL. This means that we can remove the getxattr, setxattr, and removexattr inode operations and directly call the generic handlers, or better, inline expand those handlers into fs/xattr.c. Filesystems that do not support xattrs on some inodes should clear the IOP_XATTR i_opflags flag in those inodes. (Right now, some filesystems have checks to disable xattrs on some inodes in the ->list, ->get, and ->set xattr handler operations instead.) The IOP_XATTR flag is automatically cleared in inodes of filesystems that don't have xattr support. In orangefs, symlinks do have a setxattr iop but no getxattr iop. Add a check for symlinks to orangefs_inode_getxattr to preserve the current, weird behavior; that check may not be necessary though. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-29 15:48:44 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
struct inode *(*alloc_inode)(struct super_block *sb);
new inode method: ->free_inode() A lot of ->destroy_inode() instances end with call_rcu() of a callback that does RCU-delayed part of freeing. Introduce a new method for doing just that, with saner signature. Rules: ->destroy_inode ->free_inode f g immediate call of f(), RCU-delayed call of g() f NULL immediate call of f(), no RCU-delayed calls NULL g RCU-delayed call of g() NULL NULL RCU-delayed default freeing IOW, NULL ->free_inode gives the same behaviour as now. Note that NULL, NULL is equivalent to NULL, free_inode_nonrcu; we could mandate the latter form, but that would have very little benefit beyond making rules a bit more symmetric. It would break backwards compatibility, require extra boilerplate and expected semantics for (NULL, NULL) pair would have no use whatsoever... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-10 18:43:44 +00:00
void (*free_inode)(struct inode *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void (*destroy_inode)(struct inode *);
fs: pass exact type of data dirties to ->dirty_inode Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or anything else, so that the filesystem can track internally if it needs to push out a transaction for fdatasync or not. This is just the prototype change with no user for it yet. I plan to push large XFS changes for the next merge window, and getting this trivial infrastructure in this window would help a lot to avoid tree interdependencies. Also remove incorrect comments that ->dirty_inode can't block. That has been changed a long time ago, and many implementations rely on it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-27 10:53:02 +00:00
void (*dirty_inode) (struct inode *, int flags);
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
int (*write_inode) (struct inode *, struct writeback_control *wbc);
update VFS documentation for method changes. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-06-08 04:37:12 +00:00
int (*drop_inode) (struct inode *);
void (*evict_inode) (struct inode *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void (*put_super) (struct super_block *);
int (*sync_fs)(struct super_block *sb, int wait);
filesystem freeze: add error handling of write_super_lockfs/unlockfs Currently, ext3 in mainline Linux doesn't have the freeze feature which suspends write requests. So, we cannot take a backup which keeps the filesystem's consistency with the storage device's features (snapshot and replication) while it is mounted. In many case, a commercial filesystem (e.g. VxFS) has the freeze feature and it would be used to get the consistent backup. If Linux's standard filesystem ext3 has the freeze feature, we can do it without a commercial filesystem. So I have implemented the ioctls of the freeze feature. I think we can take the consistent backup with the following steps. 1. Freeze the filesystem with the freeze ioctl. 2. Separate the replication volume or create the snapshot with the storage device's feature. 3. Unfreeze the filesystem with the unfreeze ioctl. 4. Take the backup from the separated replication volume or the snapshot. This patch: VFS: Changed the type of write_super_lockfs and unlockfs from "void" to "int" so that they can return an error. Rename write_super_lockfs and unlockfs of the super block operation freeze_fs and unfreeze_fs to avoid a confusion. ext3, ext4, xfs, gfs2, jfs: Changed the type of write_super_lockfs and unlockfs from "void" to "int" so that write_super_lockfs returns an error if needed, and unlockfs always returns 0. reiserfs: Changed the type of write_super_lockfs and unlockfs from "void" to "int" so that they always return 0 (success) to keep a current behavior. Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com> Signed-off-by: Masayuki Hamaguchi <m-hamaguchi@ys.jp.nec.com> Cc: <xfs-masters@oss.sgi.com> Cc: <linux-ext4@vger.kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-10 00:40:58 +00:00
int (*freeze_fs) (struct super_block *);
int (*unfreeze_fs) (struct super_block *);
[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry Give the statfs superblock operation a dentry pointer rather than a superblock pointer. This complements the get_sb() patch. That reduced the significance of sb->s_root, allowing NFS to place a fake root there. However, NFS does require a dentry to use as a target for the statfs operation. This permits the root in the vfsmount to be used instead. linux/mount.h has been added where necessary to make allyesconfig build successfully. Interest has also been expressed for use with the FUSE and XFS filesystems. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:58 +00:00
int (*statfs) (struct dentry *, struct kstatfs *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*remount_fs) (struct super_block *, int *, char *);
void (*umount_begin) (struct super_block *);
vfs: switch ->show_options() to struct dentry * Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-09 02:32:45 +00:00
int (*show_options)(struct seq_file *, struct dentry *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
locking rules:
update VFS documentation for method changes. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-06-08 04:37:12 +00:00
All may block [not true, see below]
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
====================== ============ ========================
ops s_umount note
====================== ============ ========================
update Documentation/filesystems/Locking The rules for locking in many superblock operations has changed significantly, so update the documentation for it. Also correct some older updates and ommissions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-19 18:22:37 +00:00
alloc_inode:
new inode method: ->free_inode() A lot of ->destroy_inode() instances end with call_rcu() of a callback that does RCU-delayed part of freeing. Introduce a new method for doing just that, with saner signature. Rules: ->destroy_inode ->free_inode f g immediate call of f(), RCU-delayed call of g() f NULL immediate call of f(), no RCU-delayed calls NULL g RCU-delayed call of g() NULL NULL RCU-delayed default freeing IOW, NULL ->free_inode gives the same behaviour as now. Note that NULL, NULL is equivalent to NULL, free_inode_nonrcu; we could mandate the latter form, but that would have very little benefit beyond making rules a bit more symmetric. It would break backwards compatibility, require extra boilerplate and expected semantics for (NULL, NULL) pair would have no use whatsoever... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-10 18:43:44 +00:00
free_inode: called from RCU callback
update Documentation/filesystems/Locking The rules for locking in many superblock operations has changed significantly, so update the documentation for it. Also correct some older updates and ommissions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-19 18:22:37 +00:00
destroy_inode:
fs: pass exact type of data dirties to ->dirty_inode Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or anything else, so that the filesystem can track internally if it needs to push out a transaction for fdatasync or not. This is just the prototype change with no user for it yet. I plan to push large XFS changes for the next merge window, and getting this trivial infrastructure in this window would help a lot to avoid tree interdependencies. Also remove incorrect comments that ->dirty_inode can't block. That has been changed a long time ago, and many implementations rely on it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-27 10:53:02 +00:00
dirty_inode:
update Documentation/filesystems/Locking The rules for locking in many superblock operations has changed significantly, so update the documentation for it. Also correct some older updates and ommissions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-19 18:22:37 +00:00
write_inode:
fs: remove inode_lock from iput_final and prune_icache Now that inode state changes are protected by the inode->i_lock and the inode LRU manipulations by the inode_lru_lock, we can remove the inode_lock from prune_icache and the initial part of iput_final(). instead of using the inode_lock to protect the inode during iput_final, use the inode->i_lock instead. This protects the inode against new references being taken while we change the inode state to I_FREEING, as well as preventing prune_icache from grabbing the inode while we are manipulating it. Hence we no longer need the inode_lock in iput_final prior to setting I_FREEING on the inode. For prune_icache, we no longer need the inode_lock to protect the LRU list, and the inodes themselves are protected against freeing races by the inode->i_lock. Hence we can lift the inode_lock from prune_icache as well. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-22 11:23:39 +00:00
drop_inode: !!!inode->i_lock!!!
update VFS documentation for method changes. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-06-08 04:37:12 +00:00
evict_inode:
update Documentation/filesystems/Locking The rules for locking in many superblock operations has changed significantly, so update the documentation for it. Also correct some older updates and ommissions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-19 18:22:37 +00:00
put_super: write
sync_fs: read
Documentation: Correct s_umount state for freeze_fs/unfreeze_fs freeze_fs/unfreeze_fs ops are called with s_umount held for write, not read. Signed-off-by: Valerie Aurora <val@vaaconsulting.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-12 14:20:48 +00:00
freeze_fs: write
unfreeze_fs: write
update VFS documentation for method changes. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-06-08 04:37:12 +00:00
statfs: maybe(read) (see below)
remount_fs: write
update Documentation/filesystems/Locking The rules for locking in many superblock operations has changed significantly, so update the documentation for it. Also correct some older updates and ommissions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-19 18:22:37 +00:00
umount_begin: no
show_options: no (namespace_sem)
quota_read: no (see below)
quota_write: no (see below)
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
====================== ============ ========================
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
update VFS documentation for method changes. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-06-08 04:37:12 +00:00
->statfs() has s_umount (shared) when called by ustat(2) (native or
compat), but that's an accident of bad API; s_umount is used to pin
the superblock down when we only have dev_t given us by userland to
identify the superblock. Everything else (statfs(), fstatfs(), etc.)
doesn't hold it when calling ->statfs() - superblock is pinned down
by resolving the pathname passed to syscall.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
->quota_read() and ->quota_write() functions are both guaranteed to
be the only ones operating on the quota file by the quota code (via
dqio_sem) (unless an admin really wants to screw up something and
writes to quota files with quotas on). For other details about locking
see also dquot_operations section.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
file_system_type
================
prototypes::
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
struct dentry *(*mount) (struct file_system_type *, int,
const char *, void *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void (*kill_sb) (struct super_block *);
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locking rules:
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
======= =========
ops may block
======= =========
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
mount yes
kill_sb yes
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
======= =========
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
vfs: bury ->get_sb() This is an ex-parrot. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-16 13:07:58 +00:00
->mount() returns ERR_PTR or the root dentry; its superblock should be locked
on return.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
->kill_sb() takes a write-locked superblock, does all shutdown work on it,
unlocks and drops the reference.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
address_space_operations
========================
prototypes::
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*writepage)(struct page *page, struct writeback_control *wbc);
fs: Add read_folio documentation Convert all the ->readpage documentation to ->read_folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-04-29 12:45:43 +00:00
int (*read_folio)(struct file *, struct folio *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*writepages)(struct address_space *, struct writeback_control *);
fs: Add aops->dirty_folio This replaces ->set_page_dirty(). It returns a bool instead of an int and takes the address_space as a parameter instead of expecting the implementations to retrieve the address_space from the page. This is particularly important for filesystems which use FS_OPS for swap. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:22:00 +00:00
bool (*dirty_folio)(struct address_space *, struct folio *folio);
mm: add readahead address space operation This replaces ->readpages with a saner interface: - Return void instead of an ignored error code. - Page cache is already populated with locked pages when ->readahead is called. - New arguments can be passed to the implementation without changing all the filesystems that use a common helper function like mpage_readahead(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Cc: Chao Yu <yuchao0@huawei.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Gao Xiang <gaoxiang25@huawei.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Cc: Miklos Szeredi <mszeredi@redhat.com> Link: http://lkml.kernel.org/r/20200414150233.24495-12-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 04:46:44 +00:00
void (*readahead)(struct readahead_control *);
fs: remove prepare_write/commit_write Nothing uses prepare_write or commit_write. Remove them from the tree completely. [akpm@linux-foundation.org: schedule simple_prepare_write() for unexporting] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-29 21:00:55 +00:00
int (*write_begin)(struct file *, struct address_space *mapping,
fs: Remove flags parameter from aops->write_begin There are no more aop flags left, so remove the parameter. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-02-22 19:31:43 +00:00
loff_t pos, unsigned len,
fs: Convert aops->write_begin to take a folio Convert all callers from working on a page to working on one page of a folio (support for working on an entire folio can come later). Removes a lot of folio->page->folio conversions. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-15 18:24:01 +00:00
struct folio **foliop, void **fsdata);
fs: remove prepare_write/commit_write Nothing uses prepare_write or commit_write. Remove them from the tree completely. [akpm@linux-foundation.org: schedule simple_prepare_write() for unexporting] Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-29 21:00:55 +00:00
int (*write_end)(struct file *, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
fs: Convert aops->write_end to take a folio Most callers have a folio, and most implementations operate on a folio, so remove the conversion from folio->page->folio to fit through this interface. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-10 19:45:32 +00:00
struct folio *folio, void *fsdata);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sector_t (*bmap)(struct address_space *, sector_t);
fs: Add invalidate_folio() aops method This is used in preference to invalidatepage, if defined. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:21:32 +00:00
void (*invalidate_folio) (struct folio *, size_t start, size_t len);
fs: Add aops->release_folio This replaces aops->releasepage. Update the documentation, and call it if it exists. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-04-29 21:00:05 +00:00
bool (*release_folio)(struct folio *, gfp_t);
fs: Add free_folio address space operation Include documentation and convert the callers to use ->free_folio as well as ->freepage. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-01 11:35:31 +00:00
void (*free_folio)(struct folio *);
direct-io: eliminate the offset argument to ->direct_IO Including blkdev_direct_IO and dax_do_io. It has to be ki_pos to actually work, so eliminate the superflous argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-07 15:51:58 +00:00
int (*direct_IO)(struct kiocb *, struct iov_iter *iter);
fs: Add aops->migrate_folio Provide a folio-based replacement for aops->migratepage. Update the documentation to document migrate_folio instead of migratepage. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-06-06 13:00:16 +00:00
int (*migrate_folio)(struct address_space *, struct folio *dst,
struct folio *src, enum migrate_mode);
fs: Add aops->launder_folio Since the only difference between ->launder_page and ->launder_folio is the type of the pointer, these can safely use a union without affecting bisectability. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:21:52 +00:00
int (*launder_folio)(struct folio *);
fs: Convert is_partially_uptodate to folios Since the uptodate property is maintained on a per-folio basis, the is_partially_uptodate method should also take a folio. Fix the types at the same time so it's clear that it returns true/false and takes the count in bytes, not blocks. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:21:27 +00:00
bool (*is_partially_uptodate)(struct folio *, size_t from, size_t count);
fs: convert error_remove_page to error_remove_folio There were already assertions that we were not passing a tail page to error_remove_page(), so make the compiler enforce that by converting everything to pass and use a folio. Link: https://lkml.kernel.org/r/20231117161447.2461643-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-17 16:14:47 +00:00
int (*error_remove_folio)(struct address_space *, struct folio *);
doc: update documentation for swap_activate and swap_rw This documentation for ->swap_activate() has been out-of-date for a long time. This patch updates it to match recent changes, and adds documentation for the associated ->swap_rw() Link: https://lkml.kernel.org/r/164859778126.29473.6778751233552859461.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-10 01:20:48 +00:00
int (*swap_activate)(struct swap_info_struct *sis, struct file *f, sector_t *span)
mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages Currently swapfiles are managed entirely by the core VM by using ->bmap to allocate space and write to the blocks directly. This effectively ensures that the underlying blocks are allocated and avoids the need for the swap subsystem to locate what physical blocks store offsets within a file. If the swap subsystem is to use the filesystem information to locate the blocks, it is critical that information such as block groups, block bitmaps and the block descriptor table that map the swap file were resident in memory. This patch adds address_space_operations that the VM can call when activating or deactivating swap backed by a file. int swap_activate(struct file *); int swap_deactivate(struct file *); The ->swap_activate() method is used to communicate to the file that the VM relies on it, and the address_space should take adequate measures such as reserving space in the underlying device, reserving memory for mempools and pinning information such as the block descriptor table in memory. The ->swap_deactivate() method is called on sys_swapoff() if ->swap_activate() returned success. After a successful swapfile ->swap_activate, the swapfile is marked SWP_FILE and swapper_space.a_ops will proxy to sis->swap_file->f_mappings->a_ops using ->direct_io to write swapcache pages and ->readpage to read. It is perfectly possible that direct_IO be used to read the swap pages but it is an unnecessary complication. Similarly, it is possible that ->writepage be used instead of direct_io to write the pages but filesystem developers have stated that calling writepage from the VM is undesirable for a variety of reasons and using direct_IO opens up the possibility of writing back batches of swap pages in the future. [a.p.zijlstra@chello.nl: Original patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 23:44:55 +00:00
int (*swap_deactivate)(struct file *);
doc: update documentation for swap_activate and swap_rw This documentation for ->swap_activate() has been out-of-date for a long time. This patch updates it to match recent changes, and adds documentation for the associated ->swap_rw() Link: https://lkml.kernel.org/r/164859778126.29473.6778751233552859461.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-10 01:20:48 +00:00
int (*swap_rw)(struct kiocb *iocb, struct iov_iter *iter);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locking rules:
fs: Add free_folio address space operation Include documentation and convert the callers to use ->free_folio as well as ->freepage. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-01 11:35:31 +00:00
All except dirty_folio and free_folio may block
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
mm: Protect operations adding pages to page cache with invalidate_lock Currently, serializing operations such as page fault, read, or readahead against hole punching is rather difficult. The basic race scheme is like: fallocate(FALLOC_FL_PUNCH_HOLE) read / fault / .. truncate_inode_pages_range() <create pages in page cache here> <update fs block mapping and free blocks> Now the problem is in this way read / page fault / readahead can instantiate pages in page cache with potentially stale data (if blocks get quickly reused). Avoiding this race is not simple - page locks do not work because we want to make sure there are *no* pages in given range. inode->i_rwsem does not work because page fault happens under mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes the performance for mixed read-write workloads suffer. So create a new rw_semaphore in the address_space - invalidate_lock - that protects adding of pages to page cache for page faults / reads / readahead. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-01-28 18:19:45 +00:00
====================== ======================== ========= ===============
fs: Add free_folio address space operation Include documentation and convert the callers to use ->free_folio as well as ->freepage. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-01 11:35:31 +00:00
ops folio locked i_rwsem invalidate_lock
mm: Protect operations adding pages to page cache with invalidate_lock Currently, serializing operations such as page fault, read, or readahead against hole punching is rather difficult. The basic race scheme is like: fallocate(FALLOC_FL_PUNCH_HOLE) read / fault / .. truncate_inode_pages_range() <create pages in page cache here> <update fs block mapping and free blocks> Now the problem is in this way read / page fault / readahead can instantiate pages in page cache with potentially stale data (if blocks get quickly reused). Avoiding this race is not simple - page locks do not work because we want to make sure there are *no* pages in given range. inode->i_rwsem does not work because page fault happens under mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes the performance for mixed read-write workloads suffer. So create a new rw_semaphore in the address_space - invalidate_lock - that protects adding of pages to page cache for page faults / reads / readahead. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-01-28 18:19:45 +00:00
====================== ======================== ========= ===============
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
writepage: yes, unlocks (see below)
fs: Add read_folio documentation Convert all the ->readpage documentation to ->read_folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-04-29 12:45:43 +00:00
read_folio: yes, unlocks shared
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
writepages:
fs: Add aops->release_folio This replaces aops->releasepage. Update the documentation, and call it if it exists. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-04-29 21:00:05 +00:00
dirty_folio: maybe
mm: Protect operations adding pages to page cache with invalidate_lock Currently, serializing operations such as page fault, read, or readahead against hole punching is rather difficult. The basic race scheme is like: fallocate(FALLOC_FL_PUNCH_HOLE) read / fault / .. truncate_inode_pages_range() <create pages in page cache here> <update fs block mapping and free blocks> Now the problem is in this way read / page fault / readahead can instantiate pages in page cache with potentially stale data (if blocks get quickly reused). Avoiding this race is not simple - page locks do not work because we want to make sure there are *no* pages in given range. inode->i_rwsem does not work because page fault happens under mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes the performance for mixed read-write workloads suffer. So create a new rw_semaphore in the address_space - invalidate_lock - that protects adding of pages to page cache for page faults / reads / readahead. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-01-28 18:19:45 +00:00
readahead: yes, unlocks shared
fs: Convert aops->write_begin to take a folio Convert all callers from working on a page to working on one page of a folio (support for working on an entire folio can come later). Removes a lot of folio->page->folio conversions. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-07-15 18:24:01 +00:00
write_begin: locks the folio exclusive
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
write_end: yes, unlocks exclusive
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
bmap:
fs: Add invalidate_folio() aops method This is used in preference to invalidatepage, if defined. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:21:32 +00:00
invalidate_folio: yes exclusive
fs: Add aops->release_folio This replaces aops->releasepage. Update the documentation, and call it if it exists. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-04-29 21:00:05 +00:00
release_folio: yes
fs: Add free_folio address space operation Include documentation and convert the callers to use ->free_folio as well as ->freepage. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-01 11:35:31 +00:00
free_folio: yes
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
direct_IO:
fs: Add aops->migrate_folio Provide a folio-based replacement for aops->migratepage. Update the documentation to document migrate_folio instead of migratepage. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-06-06 13:00:16 +00:00
migrate_folio: yes (both)
fs: Add aops->launder_folio Since the only difference between ->launder_page and ->launder_folio is the type of the pointer, these can safely use a union without affecting bisectability. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:21:52 +00:00
launder_folio: yes
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
is_partially_uptodate: yes
fs: convert error_remove_page to error_remove_folio There were already assertions that we were not passing a tail page to error_remove_page(), so make the compiler enforce that by converting everything to pass and use a folio. Link: https://lkml.kernel.org/r/20231117161447.2461643-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-11-17 16:14:47 +00:00
error_remove_folio: yes
mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages Currently swapfiles are managed entirely by the core VM by using ->bmap to allocate space and write to the blocks directly. This effectively ensures that the underlying blocks are allocated and avoids the need for the swap subsystem to locate what physical blocks store offsets within a file. If the swap subsystem is to use the filesystem information to locate the blocks, it is critical that information such as block groups, block bitmaps and the block descriptor table that map the swap file were resident in memory. This patch adds address_space_operations that the VM can call when activating or deactivating swap backed by a file. int swap_activate(struct file *); int swap_deactivate(struct file *); The ->swap_activate() method is used to communicate to the file that the VM relies on it, and the address_space should take adequate measures such as reserving space in the underlying device, reserving memory for mempools and pinning information such as the block descriptor table in memory. The ->swap_deactivate() method is called on sys_swapoff() if ->swap_activate() returned success. After a successful swapfile ->swap_activate, the swapfile is marked SWP_FILE and swapper_space.a_ops will proxy to sis->swap_file->f_mappings->a_ops using ->direct_io to write swapcache pages and ->readpage to read. It is perfectly possible that direct_IO be used to read the swap pages but it is an unnecessary complication. Similarly, it is possible that ->writepage be used instead of direct_io to write the pages but filesystem developers have stated that calling writepage from the VM is undesirable for a variety of reasons and using direct_IO opens up the possibility of writing back batches of swap pages in the future. [a.p.zijlstra@chello.nl: Original patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 23:44:55 +00:00
swap_activate: no
swap_deactivate: no
doc: update documentation for swap_activate and swap_rw This documentation for ->swap_activate() has been out-of-date for a long time. This patch updates it to match recent changes, and adds documentation for the associated ->swap_rw() Link: https://lkml.kernel.org/r/164859778126.29473.6778751233552859461.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-10 01:20:48 +00:00
swap_rw: yes, unlocks
filesystems/locking: fix Malformed table warning Update the bottom border to be the same as the top border. Documentation/filesystems/locking.rst:274: WARNING: Malformed table. Bottom/header table border does not match top border. Fixes: 730633f0b7f9 ("mm: Protect operations adding pages to page cache with invalidate_lock") Link: https://lore.kernel.org/r/20210727232212.12510-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.cz> Cc: linux-fsdevel@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz>
2021-07-27 23:22:12 +00:00
====================== ======================== ========= ===============
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
fs: Add read_folio documentation Convert all the ->readpage documentation to ->read_folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-04-29 12:45:43 +00:00
->write_begin(), ->write_end() and ->read_folio() may be called from
Remove last traces of ->sync_page Commit 7eaceaccab5f removed ->sync_page, but a few mentions of it still existed in documentation and comments, Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-07 04:27:26 +00:00
the request handler (/dev/loop).
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
fs: Add read_folio documentation Convert all the ->readpage documentation to ->read_folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-04-29 12:45:43 +00:00
->read_folio() unlocks the folio, either synchronously or via I/O
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
completion.
fs: Add read_folio documentation Convert all the ->readpage documentation to ->read_folio. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-04-29 12:45:43 +00:00
->readahead() unlocks the folios that I/O is attempted on like ->read_folio().
mm: add readahead address space operation This replaces ->readpages with a saner interface: - Return void instead of an ignored error code. - Page cache is already populated with locked pages when ->readahead is called. - New arguments can be passed to the implementation without changing all the filesystems that use a common helper function like mpage_readahead(). Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: William Kucharski <william.kucharski@oracle.com> Cc: Chao Yu <yuchao0@huawei.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Dave Chinner <dchinner@redhat.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Gao Xiang <gaoxiang25@huawei.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com> Cc: Miklos Szeredi <mszeredi@redhat.com> Link: http://lkml.kernel.org/r/20200414150233.24495-12-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-02 04:46:44 +00:00
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
->writepage() is used for two purposes: for "memory cleansing" and for
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
"sync". These are quite different operations and the behaviour may differ
depending upon the mode.
If writepage is called for sync (wbc->sync_mode != WBC_SYNC_NONE) then
it *must* start I/O against the page, even if that would involve
blocking on in-progress I/O.
If writepage is called for memory cleansing (sync_mode ==
WBC_SYNC_NONE) then its role is to get as much writeout underway as
possible. So writepage should try to avoid blocking against
currently-in-progress I/O.
If the filesystem is not called for "sync" and it determines that it
would need to block against in-progress I/O to be able to start new I/O
against the page the filesystem should redirty the page with
redirty_page_for_writepage(), then unlock the page and return zero.
This may also be done to avoid internal deadlocks, but rarely.
Fix misspellings of "system", "controller", "interrupt" and "necessary". Fix the various misspellings of "system", controller", "interrupt" and "[un]necessary". Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@kernel.org>
2007-10-19 21:10:43 +00:00
If the filesystem is called for sync then it must wait on any
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
in-progress I/O and then start new I/O.
[PATCH] doc: Locking update Make the Locking document truer. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-01 15:58:37 +00:00
The filesystem should unlock the page synchronously, before returning to the
caller, unless ->writepage() returns special WRITEPAGE_ACTIVATE
value. WRITEPAGE_ACTIVATE means that page cannot really be written out
currently, and VM should stop calling ->writepage() on this page for some
time. VM does this by moving page to the head of the active list, hence the
name.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
Unless the filesystem is going to redirty_page_for_writepage(), unlock the page
and return zero, writepage *must* run set_page_writeback() against the page,
followed by unlocking it. Once set_page_writeback() has been run against the
page, write I/O can be submitted and the write I/O completion handler must run
end_page_writeback() once the I/O is complete. If no I/O is submitted, the
filesystem must run end_page_writeback() against the page before returning from
writepage.
That is: after 2.5.12, pages which are under writeout are *not* locked. Note,
if the filesystem needs the page to be locked during writeout, that is ok, too,
the page is allowed to be unlocked at any point in time between the calls to
set_page_writeback() and end_page_writeback().
Note, failure to run either redirty_page_for_writepage() or the combination of
set_page_writeback()/end_page_writeback() on a page submitted to writepage
will leave the page itself marked clean but it will be tagged as dirty in the
radix tree. This incoherency can lead to all sorts of hard-to-debug problems
in the filesystem like having dirty inodes at umount and losing written data.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
->writepages() is used for periodic writeback and for syscall-initiated
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
sync operations. The address_space should start I/O against at least
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
``*nr_to_write`` pages. ``*nr_to_write`` must be decremented for each page
which is written. The address_space implementation may write more (or less)
pages than ``*nr_to_write`` asks for, but it should try to be reasonably close.
If nr_to_write is NULL, all dirty pages must be written.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
writepages should _only_ write pages which are present on
mapping->io_pages.
fs: Add aops->dirty_folio This replaces ->set_page_dirty(). It returns a bool instead of an int and takes the address_space as a parameter instead of expecting the implementations to retrieve the address_space from the page. This is particularly important for filesystems which use FS_OPS for swap. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:22:00 +00:00
->dirty_folio() is called from various places in the kernel when
the target folio is marked as needing writeback. The folio cannot be
truncated because either the caller holds the folio lock, or the caller
has found the folio while holding the page table lock which will block
truncation.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
->bmap() is currently used by legacy ioctl() (FIBMAP) provided by some
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
filesystems and by the swapper. The latter will eventually go away. Please,
keep it that way and don't breed new callers.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
fs: Add invalidate_folio() aops method This is used in preference to invalidatepage, if defined. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:21:32 +00:00
->invalidate_folio() is called when the filesystem must attempt to drop
mm: change invalidatepage prototype to accept length Currently there is no way to truncate partial page where the end truncate point is not at the end of the page. This is because it was not needed and the functionality was enough for file system truncate operation to work properly. However more file systems now support punch hole feature and it can benefit from mm supporting truncating page just up to the certain point. Specifically, with this functionality truncate_inode_pages_range() can be changed so it supports truncating partial page at the end of the range (currently it will BUG_ON() if 'end' is not at the end of the page). This commit changes the invalidatepage() address space operation prototype to accept range to be invalidated and update all the instances for it. We also change the block_invalidatepage() in the same way and actually make a use of the new length argument implementing range invalidation. Actual file system implementations will follow except the file systems where the changes are really simple and should not change the behaviour in any way .Implementation for truncate_page_range() which will be able to accept page unaligned ranges will follow as well. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Hugh Dickins <hughd@google.com>
2013-05-22 03:17:23 +00:00
some or all of the buffers from the page when it is being truncated. It
fs: Add invalidate_folio() aops method This is used in preference to invalidatepage, if defined. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:21:32 +00:00
returns zero on success. The filesystem must exclusively acquire
invalidate_lock before invalidating page cache in truncate / hole punch
path (and thus calling into ->invalidate_folio) to block races between page
cache invalidation and page cache filling functions (fault, read, ...).
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
doc: Correct the description of ->release_folio The filesystem ->release_folio method is called under more circumstances now than when the documentation was written. The second sentence describing the interpretation of the return value is the wrong polarity (false indicates failure, not success). And the third sentence is also wrong (the kernel calls try_to_free_buffers() instead). So replace the entire paragraph with a detailed description of what the state of the folio may be, the meaning of the gfp parameter, why the method is being called and what the filesystem is expected to do. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-06-02 20:33:20 +00:00
->release_folio() is called when the MM wants to make a change to the
folio that would invalidate the filesystem's private data. For example,
it may be about to be removed from the address_space or split. The folio
is locked and not under writeback. It may be dirty. The gfp parameter
is not usually used for allocation, but rather to indicate what the
filesystem may do to attempt to free the private data. The filesystem may
return false to indicate that the folio's private data cannot be freed.
If it returns true, it should have already removed the private data from
the folio. If a filesystem does not provide a ->release_folio method,
the pagecache will assume that private data is buffer_heads and call
try_to_free_buffers().
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
fs: Add free_folio address space operation Include documentation and convert the callers to use ->free_folio as well as ->freepage. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-05-01 11:35:31 +00:00
->free_folio() is called when the kernel has dropped the folio
Call the filesystem back whenever a page is removed from the page cache NFS needs to be able to release objects that are stored in the page cache once the page itself is no longer visible from the page cache. This patch adds a callback to the address space operations that allows filesystems to perform page cleanups once the page has been removed from the page cache. Original patch by: Linus Torvalds <torvalds@linux-foundation.org> [trondmy: cover the cases of invalidate_inode_pages2() and truncate_inode_pages()] Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-01 18:35:19 +00:00
from the page cache.
fs: Add aops->launder_folio Since the only difference between ->launder_page and ->launder_folio is the type of the pointer, these can safely use a union without affecting bisectability. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs Tested-by: David Howells <dhowells@redhat.com> # afs
2022-02-09 20:21:52 +00:00
->launder_folio() may be called prior to releasing a folio if
it is still found to be dirty. It returns zero if the folio was successfully
cleaned, or an error value if not. Note that in order to prevent the folio
[PATCH] NFS: Fix race in nfs_release_page() NFS: Fix race in nfs_release_page() invalidate_inode_pages2() may find the dirty bit has been set on a page owing to the fact that the page may still be mapped after it was locked. Only after the call to unmap_mapping_range() are we sure that the page can no longer be dirtied. In order to fix this, NFS has hooked the releasepage() method and tries to write the page out between the call to unmap_mapping_range() and the call to remove_mapping(). This, however leads to deadlocks in the page reclaim code, where the page may be locked without holding a reference to the inode or dentry. Fix is to add a new address_space_operation, launder_page(), which will attempt to write out a dirty page without releasing the page lock. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Also, the bare SetPageDirty() can skew all sort of accounting leading to other nasties. [akpm@osdl.org: cleanup] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2007-01-11 07:15:39 +00:00
getting mapped back in and redirtied, it needs to be kept locked
across the entire operation.
doc: update documentation for swap_activate and swap_rw This documentation for ->swap_activate() has been out-of-date for a long time. This patch updates it to match recent changes, and adds documentation for the associated ->swap_rw() Link: https://lkml.kernel.org/r/164859778126.29473.6778751233552859461.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-10 01:20:48 +00:00
->swap_activate() will be called to prepare the given file for swap. It
should perform any validation and preparation necessary to ensure that
writes can be performed with minimal memory allocation. It should call
add_swap_extent(), or the helper iomap_swapfile_activate(), and return
the number of extents added. If IO should be submitted through
->swap_rw(), it should set SWP_FS_OPS, otherwise IO will be submitted
directly to the block device ``sis->bdev``.
mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages Currently swapfiles are managed entirely by the core VM by using ->bmap to allocate space and write to the blocks directly. This effectively ensures that the underlying blocks are allocated and avoids the need for the swap subsystem to locate what physical blocks store offsets within a file. If the swap subsystem is to use the filesystem information to locate the blocks, it is critical that information such as block groups, block bitmaps and the block descriptor table that map the swap file were resident in memory. This patch adds address_space_operations that the VM can call when activating or deactivating swap backed by a file. int swap_activate(struct file *); int swap_deactivate(struct file *); The ->swap_activate() method is used to communicate to the file that the VM relies on it, and the address_space should take adequate measures such as reserving space in the underlying device, reserving memory for mempools and pinning information such as the block descriptor table in memory. The ->swap_deactivate() method is called on sys_swapoff() if ->swap_activate() returned success. After a successful swapfile ->swap_activate, the swapfile is marked SWP_FILE and swapper_space.a_ops will proxy to sis->swap_file->f_mappings->a_ops using ->direct_io to write swapcache pages and ->readpage to read. It is perfectly possible that direct_IO be used to read the swap pages but it is an unnecessary complication. Similarly, it is possible that ->writepage be used instead of direct_io to write the pages but filesystem developers have stated that calling writepage from the VM is undesirable for a variety of reasons and using direct_IO opens up the possibility of writing back batches of swap pages in the future. [a.p.zijlstra@chello.nl: Original patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 23:44:55 +00:00
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
->swap_deactivate() will be called in the sys_swapoff()
mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages Currently swapfiles are managed entirely by the core VM by using ->bmap to allocate space and write to the blocks directly. This effectively ensures that the underlying blocks are allocated and avoids the need for the swap subsystem to locate what physical blocks store offsets within a file. If the swap subsystem is to use the filesystem information to locate the blocks, it is critical that information such as block groups, block bitmaps and the block descriptor table that map the swap file were resident in memory. This patch adds address_space_operations that the VM can call when activating or deactivating swap backed by a file. int swap_activate(struct file *); int swap_deactivate(struct file *); The ->swap_activate() method is used to communicate to the file that the VM relies on it, and the address_space should take adequate measures such as reserving space in the underlying device, reserving memory for mempools and pinning information such as the block descriptor table in memory. The ->swap_deactivate() method is called on sys_swapoff() if ->swap_activate() returned success. After a successful swapfile ->swap_activate, the swapfile is marked SWP_FILE and swapper_space.a_ops will proxy to sis->swap_file->f_mappings->a_ops using ->direct_io to write swapcache pages and ->readpage to read. It is perfectly possible that direct_IO be used to read the swap pages but it is an unnecessary complication. Similarly, it is possible that ->writepage be used instead of direct_io to write the pages but filesystem developers have stated that calling writepage from the VM is undesirable for a variety of reasons and using direct_IO opens up the possibility of writing back batches of swap pages in the future. [a.p.zijlstra@chello.nl: Original patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-31 23:44:55 +00:00
path after ->swap_activate() returned success.
doc: update documentation for swap_activate and swap_rw This documentation for ->swap_activate() has been out-of-date for a long time. This patch updates it to match recent changes, and adds documentation for the associated ->swap_rw() Link: https://lkml.kernel.org/r/164859778126.29473.6778751233552859461.stgit@noble.brown Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Tested-by: David Howells <dhowells@redhat.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Trond Myklebust <trond.myklebust@hammerspace.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-05-10 01:20:48 +00:00
->swap_rw will be called for swap IO if SWP_FS_OPS was set by ->swap_activate().
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
file_lock_operations
====================
prototypes::
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void (*fl_copy_lock)(struct file_lock *, struct file_lock *);
void (*fl_release_private)(struct file_lock *);
locking rules:
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
=================== ============= =========
ops inode->i_lock may block
=================== ============= =========
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
fl_copy_lock: yes no
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
fl_release_private: maybe maybe[1]_
=================== ============= =========
.. [1]:
->fl_release_private for flock or POSIX locks is currently allowed
to block. Leases however can still be freed while the i_lock is held and
so fl_release_private called on a lease should not block.
locks: update Locking documentation to clarify fl_release_private behavior Acked-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-08-12 14:38:07 +00:00
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
lock_manager_operations
=======================
prototypes::
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locks: rename lock-manager ops Both the filesystem and the lock manager can associate operations with a lock. Confusingly, one of them (fl_release_private) actually has the same name in both operation structures. It would save some confusion to give the lock-manager ops different names. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-07-21 00:21:59 +00:00
void (*lm_notify)(struct file_lock *); /* unblock callback */
int (*lm_grant)(struct file_lock *, struct file_lock *, int);
void (*lm_break)(struct file_lock *); /* break_lease callback */
int (*lm_change)(struct file_lock **, int);
nfsd: clients don't need to break their own delegations We currently revoke read delegations on any write open or any operation that modifies file data or metadata (including rename, link, and unlink). But if the delegation in question is the only read delegation and is held by the client performing the operation, that's not really necessary. It's not always possible to prevent this in the NFSv4.0 case, because there's not always a way to determine which client an NFSv4.0 delegation came from. (In theory we could try to guess this from the transport layer, e.g., by assuming all traffic on a given TCP connection comes from the same client. But that's not really correct.) In the NFSv4.1 case the session layer always tells us the client. This patch should remove such self-conflicts in all cases where we can reliably determine the client from the compound. To do that we need to track "who" is performing a given (possibly lease-breaking) file operation. We're doing that by storing the information in the svc_rqst and using kthread_data() to map the current task back to a svc_rqst. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-07-28 20:35:15 +00:00
bool (*lm_breaker_owns_lease)(struct file_lock *);
fs/lock: add 2 callbacks to lock_manager_operations to resolve conflict Add 2 new callbacks, lm_lock_expirable and lm_expire_lock, to lock_manager_operations to allow the lock manager to take appropriate action to resolve the lock conflict if possible. A new field, lm_mod_owner, is also added to lock_manager_operations. The lm_mod_owner is used by the fs/lock code to make sure the lock manager module such as nfsd, is not freed while lock conflict is being resolved. lm_lock_expirable checks and returns true to indicate that the lock conflict can be resolved else return false. This callback must be called with the flc_lock held so it can not block. lm_expire_lock is called to resolve the lock conflict if the returned value from lm_lock_expirable is true. This callback is called without the flc_lock held since it's allowed to block. Upon returning from this callback, the lock conflict should be resolved and the caller is expected to restart the conflict check from the beginnning of the list. Lock manager, such as NFSv4 courteous server, uses this callback to resolve conflict by destroying lock owner, or the NFSv4 courtesy client (client that has expired but allowed to maintains its states) that owns the lock. Reviewed-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-05-02 21:19:25 +00:00
bool (*lm_lock_expirable)(struct file_lock *);
void (*lm_expire_lock)(void);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locking rules:
locks: protect most of the file_lock handling with i_lock Having a global lock that protects all of this code is a clear scalability problem. Instead of doing that, move most of the code to be protected by the i_lock instead. The exceptions are the global lists that the ->fl_link sits on, and the ->fl_block list. ->fl_link is what connects these structures to the global lists, so we must ensure that we hold those locks when iterating over or updating these lists. Furthermore, sound deadlock detection requires that we hold the blocked_list state steady while checking for loops. We also must ensure that the search and update to the list are atomic. For the checking and insertion side of the blocked_list, push the acquisition of the global lock into __posix_lock_file and ensure that checking and update of the blocked_list is done without dropping the lock in between. On the removal side, when waking up blocked lock waiters, take the global lock before walking the blocked list and dequeue the waiters from the global list prior to removal from the fl_block list. With this, deadlock detection should be race free while we minimize excessive file_lock_lock thrashing. Finally, in order to avoid a lock inversion problem when handling /proc/locks output we must ensure that manipulations of the fl_block list are also protected by the file_lock_lock. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-21 12:58:15 +00:00
Documentation: fix filesystems/locking.rst malformed table warnings Fix Sphinx malformed table warnings in filesystems/locking.rst: lnx-58-rc1/Documentation/filesystems/locking.rst:443: WARNING: Malformed table. Text in column margin in table line 8. lnx-58-rc1/Documentation/filesystems/locking.rst:620: WARNING: Malformed table. Text in column margin in table line 2. Fixes: ec23eb54fbc7 ("docs: fs: convert docs without extension to ReST") Fixes: c1e8d7c6a7a6 ("mmap locking API: convert mmap_sem comments") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Michel Lespinasse <walken@google.com> Link: https://lore.kernel.org/r/12c2afd1-2dcf-2ea0-02aa-bc2759729c77@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-15 03:22:19 +00:00
====================== ============= ================= =========
fs/lock: documentation cleanup. Replace inode->i_lock with flc_lock. Update lock usage of lock_manager_operations' functions to reflect the changes in commit 6109c85037e5 ("locks: add a dedicated spinlock to protect i_flctx lists"). Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-02-12 18:12:52 +00:00
ops flc_lock blocked_lock_lock may block
Documentation: fix filesystems/locking.rst malformed table warnings Fix Sphinx malformed table warnings in filesystems/locking.rst: lnx-58-rc1/Documentation/filesystems/locking.rst:443: WARNING: Malformed table. Text in column margin in table line 8. lnx-58-rc1/Documentation/filesystems/locking.rst:620: WARNING: Malformed table. Text in column margin in table line 2. Fixes: ec23eb54fbc7 ("docs: fs: convert docs without extension to ReST") Fixes: c1e8d7c6a7a6 ("mmap locking API: convert mmap_sem comments") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Michel Lespinasse <walken@google.com> Link: https://lore.kernel.org/r/12c2afd1-2dcf-2ea0-02aa-bc2759729c77@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-15 03:22:19 +00:00
====================== ============= ================= =========
fs/lock: documentation cleanup. Replace inode->i_lock with flc_lock. Update lock usage of lock_manager_operations' functions to reflect the changes in commit 6109c85037e5 ("locks: add a dedicated spinlock to protect i_flctx lists"). Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-02-12 18:12:52 +00:00
lm_notify: no yes no
locks: give the blocked_hash its own spinlock There's no reason we have to protect the blocked_hash and file_lock_list with the same spinlock. With the tests I have, breaking it in two gives a barely measurable performance benefit, but it seems reasonable to make this locking as granular as possible. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-21 12:58:20 +00:00
lm_grant: no no no
lm_break: yes no no
lm_change yes no no
fs/lock: documentation cleanup. Replace inode->i_lock with flc_lock. Update lock usage of lock_manager_operations' functions to reflect the changes in commit 6109c85037e5 ("locks: add a dedicated spinlock to protect i_flctx lists"). Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-02-12 18:12:52 +00:00
lm_breaker_owns_lease: yes no no
fs/lock: add 2 callbacks to lock_manager_operations to resolve conflict Add 2 new callbacks, lm_lock_expirable and lm_expire_lock, to lock_manager_operations to allow the lock manager to take appropriate action to resolve the lock conflict if possible. A new field, lm_mod_owner, is also added to lock_manager_operations. The lm_mod_owner is used by the fs/lock code to make sure the lock manager module such as nfsd, is not freed while lock conflict is being resolved. lm_lock_expirable checks and returns true to indicate that the lock conflict can be resolved else return false. This callback must be called with the flc_lock held so it can not block. lm_expire_lock is called to resolve the lock conflict if the returned value from lm_lock_expirable is true. This callback is called without the flc_lock held since it's allowed to block. Upon returning from this callback, the lock conflict should be resolved and the caller is expected to restart the conflict check from the beginnning of the list. Lock manager, such as NFSv4 courteous server, uses this callback to resolve conflict by destroying lock owner, or the NFSv4 courtesy client (client that has expired but allowed to maintains its states) that owns the lock. Reviewed-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Dai Ngo <dai.ngo@oracle.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Jeff Layton <jlayton@kernel.org>
2022-05-02 21:19:25 +00:00
lm_lock_expirable yes no no
lm_expire_lock no no yes
Documentation: fix filesystems/locking.rst malformed table warnings Fix Sphinx malformed table warnings in filesystems/locking.rst: lnx-58-rc1/Documentation/filesystems/locking.rst:443: WARNING: Malformed table. Text in column margin in table line 8. lnx-58-rc1/Documentation/filesystems/locking.rst:620: WARNING: Malformed table. Text in column margin in table line 2. Fixes: ec23eb54fbc7 ("docs: fs: convert docs without extension to ReST") Fixes: c1e8d7c6a7a6 ("mmap locking API: convert mmap_sem comments") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Michel Lespinasse <walken@google.com> Link: https://lore.kernel.org/r/12c2afd1-2dcf-2ea0-02aa-bc2759729c77@infradead.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-06-15 03:22:19 +00:00
====================== ============= ================= =========
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
buffer_head
===========
prototypes::
locks: protect most of the file_lock handling with i_lock Having a global lock that protects all of this code is a clear scalability problem. Instead of doing that, move most of the code to be protected by the i_lock instead. The exceptions are the global lists that the ->fl_link sits on, and the ->fl_block list. ->fl_link is what connects these structures to the global lists, so we must ensure that we hold those locks when iterating over or updating these lists. Furthermore, sound deadlock detection requires that we hold the blocked_list state steady while checking for loops. We also must ensure that the search and update to the list are atomic. For the checking and insertion side of the blocked_list, push the acquisition of the global lock into __posix_lock_file and ensure that checking and update of the blocked_list is done without dropping the lock in between. On the removal side, when waking up blocked lock waiters, take the global lock before walking the blocked list and dequeue the waiters from the global list prior to removal from the fl_block list. With this, deadlock detection should be race free while we minimize excessive file_lock_lock thrashing. Finally, in order to avoid a lock inversion problem when handling /proc/locks output we must ensure that manipulations of the fl_block list are also protected by the file_lock_lock. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-21 12:58:15 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
void (*b_end_io)(struct buffer_head *bh, int uptodate);
locking rules:
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
called from interrupts. In other words, extreme care is needed here.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
bh is locked, but that's all warranties we have here. Currently only RAID1,
highmem, fs/buffer.c, and fs/ntfs/aops.c are providing these. Block devices
call this method upon the IO completion.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
block_device_operations
=======================
prototypes::
update block_device_operations documentation Updated Documentation/filesystems/Locking to match the code. Signed-off-by: Christoph Hellwig <hch@lst.de>
2010-10-06 08:46:53 +00:00
int (*open) (struct block_device *, fmode_t);
int (*release) (struct gendisk *, fmode_t);
int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
pmem: kill __pmem address space The __pmem address space was meant to annotate codepaths that touch persistent memory and need to coordinate a call to wmb_pmem(). Now that wmb_pmem() is gone, there is little need to keep this annotation. Cc: Christoph Hellwig <hch@lst.de> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-06-04 01:06:47 +00:00
int (*direct_access) (struct block_device *, sector_t, void **,
pmem, dax: have direct_access use __pmem annotation Update the annotation for the kaddr pointer returned by direct_access() so that it is a __pmem pointer. This is consistent with the PMEM driver and with how this direct_access() pointer is used in the DAX code. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-18 19:55:41 +00:00
unsigned long *);
update block_device_operations documentation Updated Documentation/filesystems/Locking to match the code. Signed-off-by: Christoph Hellwig <hch@lst.de>
2010-10-06 08:46:53 +00:00
void (*unlock_native_capacity) (struct gendisk *);
int (*getgeo)(struct block_device *, struct hd_geometry *);
void (*swap_slot_free_notify) (struct block_device *, unsigned long);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locking rules:
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
======================= ===================
block: move bd_mutex to struct gendisk Replace the per-block device bd_mutex with a per-gendisk open_mutex, thus simplifying locking wherever we deal with partitions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Ming Lei <ming.lei@redhat.com> Acked-by: Roger Pau Monné <roger.pau@citrix.com> Link: https://lore.kernel.org/r/20210525061301.2242282-4-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-05-25 06:12:56 +00:00
ops open_mutex
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
======================= ===================
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
open: yes
release: yes
ioctl: no
compat_ioctl: no
direct_access: no
unlock_native_capacity: no
getgeo: no
swap_slot_free_notify: no (see below)
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
======================= ===================
update block_device_operations documentation Updated Documentation/filesystems/Locking to match the code. Signed-off-by: Christoph Hellwig <hch@lst.de>
2010-10-06 08:46:53 +00:00
swap_slot_free_notify is called with swap_lock and sometimes the page lock
held.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
file_operations
===============
prototypes::
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
loff_t (*llseek) (struct file *, loff_t, int);
ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
new methods: ->read_iter() and ->write_iter() Beginning to introduce those. Just the callers for now, and it's clumsier than it'll eventually become; once we finish converting aio_read and aio_write instances, the things will get nicer. For now, these guys are in parallel to ->aio_read() and ->aio_write(); they take iocb and iov_iter, with everything in iov_iter already validated. File offset is passed in iocb->ki_pos, iov/nr_segs - in iov_iter. Main concerns in that series are stack footprint and ability to split the damn thing cleanly. [fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-02-11 23:37:41 +00:00
ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
documentation: Sync file_operations members with reality Sync listing of struct file_operations members with the real one in fs.h. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-05-10 17:13:53 +00:00
int (*iopoll) (struct kiocb *kiocb, bool spin);
Documentation: filesystems: update filesystem locking documentation Documentation/filesystems/Locking no longer reflects current locking semantics. i_mutex is no longer used for locking, and has been superseded by i_rwsem. Additionally, ->iterate_shared() was not documented. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-24 02:29:10 +00:00
int (*iterate_shared) (struct file *, struct dir_context *);
fs: update documentation to mention __poll_t and match the code Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-02 21:50:45 +00:00
__poll_t (*poll) (struct file *, struct poll_table_struct *);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
int (*mmap) (struct file *, struct vm_area_struct *);
int (*open) (struct inode *, struct file *);
int (*flush) (struct file *);
int (*release) (struct inode *, struct file *);
fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers Btrfs needs to be able to control how filemap_write_and_wait_range() is called in fsync to make it less of a painful operation, so push down taking i_mutex and the calling of filemap_write_and_wait() down into the ->fsync() handlers. Some file systems can drop taking the i_mutex altogether it seems, like ext3 and ocfs2. For correctness sake I just pushed everything down in all cases to make sure that we keep the current behavior the same for everybody, and then each individual fs maintainer can make up their mind about what to do from there. Thanks, Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-17 00:44:56 +00:00
int (*fsync) (struct file *, loff_t start, loff_t end, int datasync);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*fasync) (int, struct file *, int);
int (*lock) (struct file *, int, struct file_lock *);
unsigned long (*get_unmapped_area)(struct file *, unsigned long,
unsigned long, unsigned long, unsigned long);
int (*check_flags)(int);
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
int (*flock) (struct file *, int, struct file_lock *);
ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *,
size_t, unsigned int);
ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *,
size_t, unsigned int);
locks: plumb a "priv" pointer into the setlease routines In later patches, we're going to add a new lock_manager_operation to finish setting up the lease while still holding the i_lock. To do this, we'll need to pass a little bit of info in the fcntl setlease case (primarily an fasync structure). Plumb the extra pointer into there in advance of that. We declare this pointer as a void ** to make it clear that this is private info, and that the caller isn't required to set this unless the lm_setup specifically requires it. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-08-22 14:40:25 +00:00
int (*setlease)(struct file *, long, struct file_lock **, void **);
fallocate should be a file operation Currently all filesystems except XFS implement fallocate asynchronously, while XFS forced a commit. Both of these are suboptimal - in case of O_SYNC I/O we really want our allocation on disk, especially for the !KEEP_SIZE case where we actually grow the file with user-visible zeroes. On the other hand always commiting the transaction is a bad idea for fast-path uses of fallocate like for example in recent Samba versions. Given that block allocation is a data plane operation anyway change it from an inode operation to a file operation so that we have the file structure available that lets us check for O_SYNC. This also includes moving the code around for a few of the filesystems, and remove the already unnedded S_ISDIR checks given that we only wire up fallocate for regular files. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-14 12:07:43 +00:00
long (*fallocate)(struct file *, int, loff_t, loff_t);
documentation: Sync file_operations members with reality Sync listing of struct file_operations members with the real one in fs.h. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-05-10 17:13:53 +00:00
void (*show_fdinfo)(struct seq_file *m, struct file *f);
unsigned (*mmap_capabilities)(struct file *);
ssize_t (*copy_file_range)(struct file *, loff_t, struct file *,
loff_t, size_t, unsigned int);
loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
loff_t len, unsigned int remap_flags);
int (*fadvise)(struct file *, loff_t, loff_t, int);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locking rules:
Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL The poll() changes were not well thought out, and completely unexplained. They also caused a huge performance regression, because "->poll()" was no longer a trivial file operation that just called down to the underlying file operations, but instead did at least two indirect calls. Indirect calls are sadly slow now with the Spectre mitigation, but the performance problem could at least be largely mitigated by changing the "->get_poll_head()" operation to just have a per-file-descriptor pointer to the poll head instead. That gets rid of one of the new indirections. But that doesn't fix the new complexity that is completely unwarranted for the regular case. The (undocumented) reason for the poll() changes was some alleged AIO poll race fixing, but we don't make the common case slower and more complex for some uncommon special case, so this all really needs way more explanations and most likely a fundamental redesign. [ This revert is a revert of about 30 different commits, not reverted individually because that would just be unnecessarily messy - Linus ] Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28 16:43:44 +00:00
All may block.
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
->llseek() locking has moved from llseek to the individual llseek
implementations. If your fs is not using generic_file_llseek, you
need to acquire and release the appropriate locks in your ->llseek().
For many filesystems, it is probably safe to acquire the inode
Documentation/filesystems/Locking: update documentation on llseek() wrt BKL The inode's i_size is not protected by the big kernel lock. Therefore it does not make sense to recommend taking the BKL in filesystems llseek operations. Instead it should use the inode's mutex or use just use i_size_read() instead. Add a note that this is not protecting file->f_pos. Signed-off-by: Jan Blunck <jblunck@suse.de> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Kacur <jkacur@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-26 21:44:54 +00:00
mutex or just to use i_size_read() instead.
Note: this does not protect the file->f_pos against concurrent modifications
since this is something the userspace has to take care about.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
vfs: get rid of old '->iterate' directory operation All users now just use '->iterate_shared()', which only takes the directory inode lock for reading. Filesystems that never got convered to shared mode now instead use a wrapper that drops the lock, re-takes it in write mode, calls the old function, and then downgrades the lock back to read mode. This way the VFS layer and other callers no longer need to care about filesystems that never got converted to the modern era. The filesystems that use the new wrapper are ceph, coda, exfat, jfs, ntfs, ocfs2, overlayfs, and vboxsf. Honestly, several of them look like they really could just iterate their directories in shared mode and skip the wrapper entirely, but the point of this change is to not change semantics or fix filesystems that haven't been fixed in the last 7+ years, but to finally get rid of the dual iterators. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-08-05 19:25:01 +00:00
->iterate_shared() is called with i_rwsem held for reading, and with the
file f_pos_lock held exclusively
Documentation: filesystems: update filesystem locking documentation Documentation/filesystems/Locking no longer reflects current locking semantics. i_mutex is no longer used for locking, and has been superseded by i_rwsem. Additionally, ->iterate_shared() was not documented. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-05-24 02:29:10 +00:00
update Documentation/filesystems/Locking Mostly inspired by all the recent BKL removal changes, but a lot of older updates also weren't properly recorded. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-16 11:04:54 +00:00
->fasync() is responsible for maintaining the FASYNC bit in filp->f_flags.
Most instances call fasync_helper(), which does that maintenance, so it's
not normally something one needs to worry about. Return values > 0 will be
mapped to zero in the VFS layer.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
->readdir() and ->ioctl() on directories must be changed. Ideally we would
move ->readdir() to inode_operations and use a separate method for directory
->ioctl() or kill the latter completely. One of the problems is that for
anything that resembles union-mount we won't have a struct file for all
components. And there are other reasons why the current interface is a mess...
->read on directories probably must go away - we should just enforce -EISDIR
in sys_read() and friends.
locks: move i_lock acquisition into generic_*_lease handlers Now that we have a saner internal API for managing leases, we no longer need to mandate that the inode->i_lock be held over most of the lease code. Push it down into generic_add_lease and generic_delete_lease. Signed-off-by: Jeff Layton <jlayton@primarydata.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-08-22 22:50:48 +00:00
->setlease operations should call generic_setlease() before or after setting
the lease within the individual filesystem to record the result of the
operation
mm: Protect operations adding pages to page cache with invalidate_lock Currently, serializing operations such as page fault, read, or readahead against hole punching is rather difficult. The basic race scheme is like: fallocate(FALLOC_FL_PUNCH_HOLE) read / fault / .. truncate_inode_pages_range() <create pages in page cache here> <update fs block mapping and free blocks> Now the problem is in this way read / page fault / readahead can instantiate pages in page cache with potentially stale data (if blocks get quickly reused). Avoiding this race is not simple - page locks do not work because we want to make sure there are *no* pages in given range. inode->i_rwsem does not work because page fault happens under mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes the performance for mixed read-write workloads suffer. So create a new rw_semaphore in the address_space - invalidate_lock - that protects adding of pages to page cache for page faults / reads / readahead. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-01-28 18:19:45 +00:00
->fallocate implementation must be really careful to maintain page cache
consistency when punching holes or performing other operations that invalidate
page cache contents. Usually the filesystem needs to call
truncate_inode_pages_range() to invalidate relevant range of the page cache.
However the filesystem usually also needs to update its internal (and on disk)
view of file offset -> disk block mapping. Until this update is finished, the
filesystem needs to block page faults and reads from reloading now-stale page
cache contents from the disk. Since VFS acquires mapping->invalidate_lock in
shared mode when loading pages from disk (filemap_fault(), filemap_read(),
readahead paths), the fallocate implementation must take the invalidate_lock to
prevent reloading.
->copy_file_range and ->remap_file_range implementations need to serialize
against modifications of file data while the operation is running. For
blocking changes through write(2) and similar operations inode->i_rwsem can be
used. To block changes to file contents via a memory mapping during the
operation, the filesystem must take mapping->invalidate_lock to coordinate
with ->page_mkwrite.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
dquot_operations
================
prototypes::
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
int (*write_dquot) (struct dquot *);
int (*acquire_dquot) (struct dquot *);
int (*release_dquot) (struct dquot *);
int (*mark_dirty) (struct dquot *);
int (*write_info) (struct super_block *, int);
These operations are intended to be more or less wrapping functions that ensure
a proper locking wrt the filesystem and call the generic quota operations.
What filesystem should expect from the generic quota functions:
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
============== ============ =========================
ops FS recursion Held locks when called
============== ============ =========================
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
write_dquot: yes dqonoff_sem or dqptr_sem
acquire_dquot: yes dqonoff_sem or dqptr_sem
release_dquot: yes dqonoff_sem or dqptr_sem
mark_dirty: no -
write_info: yes dqonoff_sem
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
============== ============ =========================
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
FS recursion means calling ->quota_read() and ->quota_write() from superblock
operations.
More details about quota locking can be found in fs/dquot.c.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
vm_operations_struct
====================
prototypes::
mm: allow ->huge_fault() to be called without the mmap_lock held Remove the checks for the VMA lock being held, allowing the page fault path to call into the filesystem instead of retrying with the mmap_lock held. This will improve scalability for DAX page faults. Also update the documentation to match (and fix some other changes that have happened recently). Link: https://lkml.kernel.org/r/20230818202335.2739663-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 20:23:34 +00:00
void (*open)(struct vm_area_struct *);
void (*close)(struct vm_area_struct *);
vm_fault_t (*fault)(struct vm_fault *);
vm_fault_t (*huge_fault)(struct vm_fault *, unsigned int order);
vm_fault_t (*map_pages)(struct vm_fault *, pgoff_t start, pgoff_t end);
mm: Introduce new type vm_fault_t We have introduce a new return type vm_fault_t for fault, page_mkwrite and pfn_mkwrite handlers. Update the document for the same Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2018-07-22 13:01:34 +00:00
vm_fault_t (*page_mkwrite)(struct vm_area_struct *, struct vm_fault *);
vm_fault_t (*pfn_mkwrite)(struct vm_area_struct *, struct vm_fault *);
access_process_vm device memory infrastructure In order to be able to debug things like the X server and programs using the PPC Cell SPUs, the debugger needs to be able to access device memory through ptrace and /proc/pid/mem. This patch: Add the generic_access_phys access function and put the hooks in place to allow access_process_vm to access device or PPC Cell SPU memory. [riel@redhat.com: Add documentation for the vm_ops->access function] Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Benjamin Herrensmidt <benh@kernel.crashing.org> Cc: Dave Airlie <airlied@linux.ie> Cc: Hugh Dickins <hugh@veritas.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 04:27:05 +00:00
int (*access)(struct vm_area_struct *, unsigned long, void*, int, int);
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
locking rules:
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
mm: allow ->huge_fault() to be called without the mmap_lock held Remove the checks for the VMA lock being held, allowing the page fault path to call into the filesystem instead of retrying with the mmap_lock held. This will improve scalability for DAX page faults. Also update the documentation to match (and fix some other changes that have happened recently). Link: https://lkml.kernel.org/r/20230818202335.2739663-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 20:23:34 +00:00
============= ========== ===========================
mmap locking API: convert mmap_sem comments Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 04:33:54 +00:00
ops mmap_lock PageLocked(page)
mm: allow ->huge_fault() to be called without the mmap_lock held Remove the checks for the VMA lock being held, allowing the page fault path to call into the filesystem instead of retrying with the mmap_lock held. This will improve scalability for DAX page faults. Also update the documentation to match (and fix some other changes that have happened recently). Link: https://lkml.kernel.org/r/20230818202335.2739663-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 20:23:34 +00:00
============= ========== ===========================
open: write
close: read/write
fault: read can return with page locked
huge_fault: maybe-read
map_pages: maybe-read
page_mkwrite: read can return with page locked
pfn_mkwrite: read
access: read
============= ========== ===========================
Document ->page_mkwrite() locking There seems to be very little documentation about this callback in general. The locking in particular is a bit tricky, so it's worth having this in writing. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19 08:47:01 +00:00
mm: Protect operations adding pages to page cache with invalidate_lock Currently, serializing operations such as page fault, read, or readahead against hole punching is rather difficult. The basic race scheme is like: fallocate(FALLOC_FL_PUNCH_HOLE) read / fault / .. truncate_inode_pages_range() <create pages in page cache here> <update fs block mapping and free blocks> Now the problem is in this way read / page fault / readahead can instantiate pages in page cache with potentially stale data (if blocks get quickly reused). Avoiding this race is not simple - page locks do not work because we want to make sure there are *no* pages in given range. inode->i_rwsem does not work because page fault happens under mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes the performance for mixed read-write workloads suffer. So create a new rw_semaphore in the address_space - invalidate_lock - that protects adding of pages to page cache for page faults / reads / readahead. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-01-28 18:19:45 +00:00
->fault() is called when a previously not present pte is about to be faulted
in. The filesystem must find and return the page associated with the passed in
"pgoff" in the vm_fault structure. If it is possible that the page may be
truncated and/or invalidated, then the filesystem must lock invalidate_lock,
then ensure the page is not already truncated (invalidate_lock will block
mm: close page_mkwrite races Change page_mkwrite to allow implementations to return with the page locked, and also change it's callers (in page fault paths) to hold the lock until the page is marked dirty. This allows the filesystem to have full control of page dirtying events coming from the VM. Rather than simply hold the page locked over the page_mkwrite call, we call page_mkwrite with the page unlocked and allow callers to return with it locked, so filesystems can avoid LOR conditions with page lock. The problem with the current scheme is this: a filesystem that wants to associate some metadata with a page as long as the page is dirty, will perform this manipulation in its ->page_mkwrite. It currently then must return with the page unlocked and may not hold any other locks (according to existing page_mkwrite convention). In this window, the VM could write out the page, clearing page-dirty. The filesystem has no good way to detect that a dirty pte is about to be attached, so it will happily write out the page, at which point, the filesystem may manipulate the metadata to reflect that the page is no longer dirty. It is not always possible to perform the required metadata manipulation in ->set_page_dirty, because that function cannot block or fail. The filesystem may need to allocate some data structure, for example. And the VM cannot mark the pte dirty before page_mkwrite, because page_mkwrite is allowed to fail, so we must not allow any window where the page could be written to if page_mkwrite does fail. This solution of holding the page locked over the 3 critical operations (page_mkwrite, setting the pte dirty, and finally setting the page dirty) closes out races nicely, preventing page cleaning for writeout being initiated in that window. This provides the filesystem with a strong synchronisation against the VM here. - Sage needs this race closed for ceph filesystem. - Trond for NFS (http://bugzilla.kernel.org/show_bug.cgi?id=12913). - I need it for fsblock. - I suspect other filesystems may need it too (eg. btrfs). - I have converted buffer.c to the new locking. Even simple block allocation under dirty pages might be susceptible to i_size changing under partial page at the end of file (we also have a buffer.c-side problem here, but it cannot be fixed properly without this patch). - Other filesystems (eg. NFS, maybe btrfs) will need to change their page_mkwrite functions themselves. [ This also moves page_mkwrite another step closer to fault, which should eventually allow page_mkwrite to be moved into ->fault, and thus avoiding a filesystem calldown and page lock/unlock cycle in __do_fault. ] [akpm@linux-foundation.org: fix derefs of NULL ->mapping] Cc: Sage Weil <sage@newdream.net> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-30 22:08:16 +00:00
subsequent truncate), and then return with VM_FAULT_LOCKED, and the page
locked. The VM will unlock the page.
mm: allow ->huge_fault() to be called without the mmap_lock held Remove the checks for the VMA lock being held, allowing the page fault path to call into the filesystem instead of retrying with the mmap_lock held. This will improve scalability for DAX page faults. Also update the documentation to match (and fix some other changes that have happened recently). Link: https://lkml.kernel.org/r/20230818202335.2739663-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-18 20:23:34 +00:00
->huge_fault() is called when there is no PUD or PMD entry present. This
gives the filesystem the opportunity to install a PUD or PMD sized page.
Filesystems can also use the ->fault method to return a PMD sized page,
so implementing this function may not be necessary. In particular,
filesystems should not call filemap_fault() from ->huge_fault().
The mmap_lock may not be held when this method is called.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
->map_pages() is called when VM asks to map easy accessible pages.
mm: introduce fault_env The idea borrowed from Peter's patch from patchset on speculative page faults[1]: Instead of passing around the endless list of function arguments, replace the lot with a single structure so we can change context without endless function signature changes. The changes are mostly mechanical with exception of faultaround code: filemap_map_pages() got reworked a bit. This patch is preparation for the next one. [1] http://lkml.kernel.org/r/20141020222841.302891540@infradead.org Link: http://lkml.kernel.org/r/1466021202-61880-9-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 22:25:20 +00:00
Filesystem should find and map pages associated with offsets from "start_pgoff"
mm: hold the RCU read lock over calls to ->map_pages Prevent filesystems from doing things which sleep in their map_pages method. This is in preparation for a pagefault path protected only by RCU. Link: https://lkml.kernel.org/r/20230327174515.1811532-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-27 17:45:15 +00:00
till "end_pgoff". ->map_pages() is called with the RCU lock held and must
mm: introduce vm_ops->map_pages() Here's new version of faultaround patchset. It took a while to tune it and collect performance data. First patch adds new callback ->map_pages to vm_operations_struct. ->map_pages() is called when VM asks to map easy accessible pages. Filesystem should find and map pages associated with offsets from "pgoff" till "max_pgoff". ->map_pages() is called with page table locked and must not block. If it's not possible to reach a page without blocking, filesystem should skip it. Filesystem should use do_set_pte() to setup page table entry. Pointer to entry associated with offset "pgoff" is passed in "pte" field in vm_fault structure. Pointers to entries for other offsets should be calculated relative to "pte". Currently VM use ->map_pages only on read page fault path. We try to map FAULT_AROUND_PAGES a time. FAULT_AROUND_PAGES is 16 for now. Performance data for different FAULT_AROUND_ORDER is below. TODO: - implement ->map_pages() for shmem/tmpfs; - modify get_user_pages() to be able to use ->map_pages() and implement mmap(MAP_POPULATE|MAP_NONBLOCK) on top. ========================================================================= Tested on 4-socket machine (120 threads) with 128GiB of RAM. Few real-world workloads. The sweet spot for FAULT_AROUND_ORDER here is somewhere between 3 and 5. Let's say 4 :) Linux build (make -j60) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 283,301,572 247,151,987 212,215,789 204,772,882 199,568,944 194,703,779 193,381,485 time, seconds 151.227629483 153.920996480 151.356125472 150.863792049 150.879207877 151.150764954 151.450962358 Linux rebuild (make -j60) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 5,396,854 4,148,444 2,855,286 2,577,282 2,361,957 2,169,573 2,112,643 time, seconds 27.404543757 27.559725591 27.030057426 26.855045126 26.678618635 26.974523490 26.761320095 Git test suite (make -j60 test) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 129,591,823 99,200,751 66,106,718 57,606,410 51,510,808 45,776,813 44,085,515 time, seconds 66.087215026 64.784546905 64.401156567 65.282708668 66.034016829 66.793780811 67.237810413 Two synthetic tests: access every word in file in sequential/random order. It doesn't improve much after FAULT_AROUND_ORDER == 4. Sequential access 16GiB file FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 1 thread minor-faults 4,195,437 2,098,275 525,068 262,251 131,170 32,856 8,282 time, seconds 7.250461742 6.461711074 5.493859139 5.488488147 5.707213983 5.898510832 5.109232856 8 threads minor-faults 33,557,540 16,892,728 4,515,848 2,366,999 1,423,382 442,732 142,339 time, seconds 16.649304881 9.312555263 6.612490639 6.394316732 6.669827501 6.75078944 6.371900528 32 threads minor-faults 134,228,222 67,526,810 17,725,386 9,716,537 4,763,731 1,668,921 537,200 time, seconds 49.164430543 29.712060103 12.938649729 10.175151004 11.840094583 9.594081325 9.928461797 60 threads minor-faults 251,687,988 126,146,952 32,919,406 18,208,804 10,458,947 2,733,907 928,217 time, seconds 86.260656897 49.626551828 22.335007632 17.608243696 16.523119035 16.339489186 16.326390902 120 threads minor-faults 503,352,863 252,939,677 67,039,168 35,191,827 19,170,091 4,688,357 1,471,862 time, seconds 124.589206333 79.757867787 39.508707872 32.167281632 29.972989292 28.729834575 28.042251622 Random access 1GiB file 1 thread minor-faults 262,636 132,743 34,369 17,299 8,527 3,451 1,222 time, seconds 15.351890914 16.613802482 16.569227308 15.179220992 16.557356122 16.578247824 15.365266994 8 threads minor-faults 2,098,948 1,061,871 273,690 154,501 87,110 25,663 7,384 time, seconds 15.040026343 15.096933500 14.474757288 14.289129964 14.411537468 14.296316837 14.395635804 32 threads minor-faults 8,390,734 4,231,023 1,054,432 528,847 269,242 97,746 26,881 time, seconds 20.430433109 21.585235358 22.115062928 14.872878951 14.880856305 14.883370649 14.821261690 60 threads minor-faults 15,733,258 7,892,809 1,973,393 988,266 594,789 164,994 51,691 time, seconds 26.577302548 25.692397770 18.728863715 20.153026398 21.619101933 17.745086260 17.613215273 120 threads minor-faults 31,471,111 15,816,616 3,959,209 1,978,685 1,008,299 264,635 96,010 time, seconds 41.835322703 40.459786095 36.085306105 35.313894834 35.814445675 36.552633793 34.289210594 Touch only one page in page table in 16GiB file FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 1 thread minor-faults 8,372 8,324 8,270 8,260 8,249 8,239 8,237 time, seconds 0.039892712 0.045369149 0.051846126 0.063681685 0.079095975 0.17652406 0.541213386 8 threads minor-faults 65,731 65,681 65,628 65,620 65,608 65,599 65,596 time, seconds 0.124159196 0.488600638 0.156854426 0.191901957 0.242631486 0.543569456 1.677303984 32 threads minor-faults 262,388 262,341 262,285 262,276 262,266 262,257 263,183 time, seconds 0.452421421 0.488600638 0.565020946 0.648229739 0.789850823 1.651584361 5.000361559 60 threads minor-faults 491,822 491,792 491,723 491,711 491,701 491,691 491,825 time, seconds 0.763288616 0.869620515 0.980727360 1.161732354 1.466915814 3.04041448 9.308612938 120 threads minor-faults 983,466 983,655 983,366 983,372 983,363 984,083 984,164 time, seconds 1.595846553 1.667902182 2.008959376 2.425380942 2.941368804 5.977807890 18.401846125 This patch (of 2): Introduce new vm_ops callback ->map_pages() and uses it for mapping easy accessible pages around fault address. On read page fault, if filesystem provides ->map_pages(), we try to map up to FAULT_AROUND_PAGES pages around page fault address in hope to reduce number of minor page faults. We call ->map_pages first and use ->fault() as fallback if page by the offset is not ready to be mapped (cold page cache or something). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <david@fromorbit.com> Cc: Ning Qu <quning@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 22:37:18 +00:00
not block. If it's not possible to reach a page without blocking,
mm: convert do_set_pte() to set_pte_range() set_pte_range() allows to setup page table entries for a specific range. It takes advantage of batched rmap update for large folio. It now takes care of calling update_mmu_cache_range(). Link: https://lkml.kernel.org/r/20230802151406.3735276-37-willy@infradead.org Signed-off-by: Yin Fengwei <fengwei.yin@intel.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-08-02 15:14:04 +00:00
filesystem should skip it. Filesystem should use set_pte_range() to setup
mm: introduce fault_env The idea borrowed from Peter's patch from patchset on speculative page faults[1]: Instead of passing around the endless list of function arguments, replace the lot with a single structure so we can change context without endless function signature changes. The changes are mostly mechanical with exception of faultaround code: filemap_map_pages() got reworked a bit. This patch is preparation for the next one. [1] http://lkml.kernel.org/r/20141020222841.302891540@infradead.org Link: http://lkml.kernel.org/r/1466021202-61880-9-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 22:25:20 +00:00
page table entry. Pointer to entry associated with the page is passed in
mm: join struct fault_env and vm_fault Currently we have two different structures for passing fault information around - struct vm_fault and struct fault_env. DAX will need more information in struct vm_fault to handle its faults so the content of that structure would become event closer to fault_env. Furthermore it would need to generate struct fault_env to be able to call some of the generic functions. So at this point I don't think there's much use in keeping these two structures separate. Just embed into struct vm_fault all that is needed to use it for both purposes. Link: http://lkml.kernel.org/r/1479460644-25076-2-git-send-email-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-14 23:06:58 +00:00
"pte" field in vm_fault structure. Pointers to entries for other offsets
mm: introduce fault_env The idea borrowed from Peter's patch from patchset on speculative page faults[1]: Instead of passing around the endless list of function arguments, replace the lot with a single structure so we can change context without endless function signature changes. The changes are mostly mechanical with exception of faultaround code: filemap_map_pages() got reworked a bit. This patch is preparation for the next one. [1] http://lkml.kernel.org/r/20141020222841.302891540@infradead.org Link: http://lkml.kernel.org/r/1466021202-61880-9-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 22:25:20 +00:00
should be calculated relative to "pte".
mm: introduce vm_ops->map_pages() Here's new version of faultaround patchset. It took a while to tune it and collect performance data. First patch adds new callback ->map_pages to vm_operations_struct. ->map_pages() is called when VM asks to map easy accessible pages. Filesystem should find and map pages associated with offsets from "pgoff" till "max_pgoff". ->map_pages() is called with page table locked and must not block. If it's not possible to reach a page without blocking, filesystem should skip it. Filesystem should use do_set_pte() to setup page table entry. Pointer to entry associated with offset "pgoff" is passed in "pte" field in vm_fault structure. Pointers to entries for other offsets should be calculated relative to "pte". Currently VM use ->map_pages only on read page fault path. We try to map FAULT_AROUND_PAGES a time. FAULT_AROUND_PAGES is 16 for now. Performance data for different FAULT_AROUND_ORDER is below. TODO: - implement ->map_pages() for shmem/tmpfs; - modify get_user_pages() to be able to use ->map_pages() and implement mmap(MAP_POPULATE|MAP_NONBLOCK) on top. ========================================================================= Tested on 4-socket machine (120 threads) with 128GiB of RAM. Few real-world workloads. The sweet spot for FAULT_AROUND_ORDER here is somewhere between 3 and 5. Let's say 4 :) Linux build (make -j60) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 283,301,572 247,151,987 212,215,789 204,772,882 199,568,944 194,703,779 193,381,485 time, seconds 151.227629483 153.920996480 151.356125472 150.863792049 150.879207877 151.150764954 151.450962358 Linux rebuild (make -j60) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 5,396,854 4,148,444 2,855,286 2,577,282 2,361,957 2,169,573 2,112,643 time, seconds 27.404543757 27.559725591 27.030057426 26.855045126 26.678618635 26.974523490 26.761320095 Git test suite (make -j60 test) FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 minor-faults 129,591,823 99,200,751 66,106,718 57,606,410 51,510,808 45,776,813 44,085,515 time, seconds 66.087215026 64.784546905 64.401156567 65.282708668 66.034016829 66.793780811 67.237810413 Two synthetic tests: access every word in file in sequential/random order. It doesn't improve much after FAULT_AROUND_ORDER == 4. Sequential access 16GiB file FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 1 thread minor-faults 4,195,437 2,098,275 525,068 262,251 131,170 32,856 8,282 time, seconds 7.250461742 6.461711074 5.493859139 5.488488147 5.707213983 5.898510832 5.109232856 8 threads minor-faults 33,557,540 16,892,728 4,515,848 2,366,999 1,423,382 442,732 142,339 time, seconds 16.649304881 9.312555263 6.612490639 6.394316732 6.669827501 6.75078944 6.371900528 32 threads minor-faults 134,228,222 67,526,810 17,725,386 9,716,537 4,763,731 1,668,921 537,200 time, seconds 49.164430543 29.712060103 12.938649729 10.175151004 11.840094583 9.594081325 9.928461797 60 threads minor-faults 251,687,988 126,146,952 32,919,406 18,208,804 10,458,947 2,733,907 928,217 time, seconds 86.260656897 49.626551828 22.335007632 17.608243696 16.523119035 16.339489186 16.326390902 120 threads minor-faults 503,352,863 252,939,677 67,039,168 35,191,827 19,170,091 4,688,357 1,471,862 time, seconds 124.589206333 79.757867787 39.508707872 32.167281632 29.972989292 28.729834575 28.042251622 Random access 1GiB file 1 thread minor-faults 262,636 132,743 34,369 17,299 8,527 3,451 1,222 time, seconds 15.351890914 16.613802482 16.569227308 15.179220992 16.557356122 16.578247824 15.365266994 8 threads minor-faults 2,098,948 1,061,871 273,690 154,501 87,110 25,663 7,384 time, seconds 15.040026343 15.096933500 14.474757288 14.289129964 14.411537468 14.296316837 14.395635804 32 threads minor-faults 8,390,734 4,231,023 1,054,432 528,847 269,242 97,746 26,881 time, seconds 20.430433109 21.585235358 22.115062928 14.872878951 14.880856305 14.883370649 14.821261690 60 threads minor-faults 15,733,258 7,892,809 1,973,393 988,266 594,789 164,994 51,691 time, seconds 26.577302548 25.692397770 18.728863715 20.153026398 21.619101933 17.745086260 17.613215273 120 threads minor-faults 31,471,111 15,816,616 3,959,209 1,978,685 1,008,299 264,635 96,010 time, seconds 41.835322703 40.459786095 36.085306105 35.313894834 35.814445675 36.552633793 34.289210594 Touch only one page in page table in 16GiB file FAULT_AROUND_ORDER Baseline 1 3 4 5 7 9 1 thread minor-faults 8,372 8,324 8,270 8,260 8,249 8,239 8,237 time, seconds 0.039892712 0.045369149 0.051846126 0.063681685 0.079095975 0.17652406 0.541213386 8 threads minor-faults 65,731 65,681 65,628 65,620 65,608 65,599 65,596 time, seconds 0.124159196 0.488600638 0.156854426 0.191901957 0.242631486 0.543569456 1.677303984 32 threads minor-faults 262,388 262,341 262,285 262,276 262,266 262,257 263,183 time, seconds 0.452421421 0.488600638 0.565020946 0.648229739 0.789850823 1.651584361 5.000361559 60 threads minor-faults 491,822 491,792 491,723 491,711 491,701 491,691 491,825 time, seconds 0.763288616 0.869620515 0.980727360 1.161732354 1.466915814 3.04041448 9.308612938 120 threads minor-faults 983,466 983,655 983,366 983,372 983,363 984,083 984,164 time, seconds 1.595846553 1.667902182 2.008959376 2.425380942 2.941368804 5.977807890 18.401846125 This patch (of 2): Introduce new vm_ops callback ->map_pages() and uses it for mapping easy accessible pages around fault address. On read page fault, if filesystem provides ->map_pages(), we try to map up to FAULT_AROUND_PAGES pages around page fault address in hope to reduce number of minor page faults. We call ->map_pages first and use ->fault() as fallback if page by the offset is not ready to be mapped (cold page cache or something). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dave Chinner <david@fromorbit.com> Cc: Ning Qu <quning@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 22:37:18 +00:00
mm: Protect operations adding pages to page cache with invalidate_lock Currently, serializing operations such as page fault, read, or readahead against hole punching is rather difficult. The basic race scheme is like: fallocate(FALLOC_FL_PUNCH_HOLE) read / fault / .. truncate_inode_pages_range() <create pages in page cache here> <update fs block mapping and free blocks> Now the problem is in this way read / page fault / readahead can instantiate pages in page cache with potentially stale data (if blocks get quickly reused). Avoiding this race is not simple - page locks do not work because we want to make sure there are *no* pages in given range. inode->i_rwsem does not work because page fault happens under mmap_sem which ranks below inode->i_rwsem. Also using it for reads makes the performance for mixed read-write workloads suffer. So create a new rw_semaphore in the address_space - invalidate_lock - that protects adding of pages to page cache for page faults / reads / readahead. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-01-28 18:19:45 +00:00
->page_mkwrite() is called when a previously read-only pte is about to become
writeable. The filesystem again must ensure that there are no
truncate/invalidate races or races with operations such as ->remap_file_range
or ->copy_file_range, and then return with the page locked. Usually
mapping->invalidate_lock is suitable for proper serialization. If the page has
been truncated, the filesystem should not look up a new page like the ->fault()
handler, but simply return with VM_FAULT_NOPAGE, which will cause the VM to
retry the fault.
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
->pfn_mkwrite() is the same as page_mkwrite but when the pte is
mm: new pfn_mkwrite same as page_mkwrite for VM_PFNMAP This will allow FS that uses VM_PFNMAP | VM_MIXEDMAP (no page structs) to get notified when access is a write to a read-only PFN. This can happen if we mmap() a file then first mmap-read from it to page-in a read-only PFN, than we mmap-write to the same page. We need this functionality to fix a DAX bug, where in the scenario above we fail to set ctime/mtime though we modified the file. An xfstest is attached to this patchset that shows the failure and the fix. (A DAX patch will follow) This functionality is extra important for us, because upon dirtying of a pmem page we also want to RDMA the page to a remote cluster node. We define a new pfn_mkwrite and do not reuse page_mkwrite because 1 - The name ;-) 2 - But mainly because it would take a very long and tedious audit of all page_mkwrite functions of VM_MIXEDMAP/VM_PFNMAP users. To make sure they do not now CRASH. For example current DAX code (which this is for) would crash. If we would want to reuse page_mkwrite, We will need to first patch all users, so to not-crash-on-no-page. Then enable this patch. But even if I did that I would not sleep so well at night. Adding a new vector is the safest thing to do, and is not that expensive. an extra pointer at a static function vector per driver. Also the new vector is better for performance, because else we Will call all current Kernel vectors, so to: check-ha-no-page-do-nothing and return. No need to call it from do_shared_fault because do_wp_page is called to change pte permissions anyway. Signed-off-by: Yigal Korman <yigal@plexistor.com> Signed-off-by: Boaz Harrosh <boaz@plexistor.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 23:15:11 +00:00
VM_PFNMAP or VM_MIXEDMAP with a page-less entry. Expected return is
VM_FAULT_NOPAGE. Or one of the VM_FAULT_ERROR types. The default behavior
after this call is to make the pte read-write, unless pfn_mkwrite returns
an error.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
->access() is called when get_user_pages() fails in
doc: Fix typo (acces_process_vm -> access_process_vm) Signed-off-by: Stefan Weil <sw@weilnetz.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-12-05 19:34:05 +00:00
access_process_vm(), typically used to debug a process through
access_process_vm device memory infrastructure In order to be able to debug things like the X server and programs using the PPC Cell SPUs, the debugger needs to be able to access device memory through ptrace and /proc/pid/mem. This patch: Add the generic_access_phys access function and put the hooks in place to allow access_process_vm to access device or PPC Cell SPU memory. [riel@redhat.com: Add documentation for the vm_ops->access function] Signed-off-by: Rik van Riel <riel@redhat.com> Signed-off-by: Benjamin Herrensmidt <benh@kernel.crashing.org> Cc: Dave Airlie <airlied@linux.ie> Cc: Hugh Dickins <hugh@veritas.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnd Bergmann <arnd@arndb.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-24 04:27:05 +00:00
/proc/pid/mem or ptrace. This function is needed only for
VM_IO | VM_PFNMAP VMAs.
docs: fs: convert docs without extension to ReST There are 3 remaining files without an extension inside the fs docs dir. Manually convert them to ReST. In the case of the nfs/exporting.rst file, as the nfs docs aren't ported yet, I opted to convert and add a :orphan: there, with should be removed when it gets added into a nfs-specific part of the fs documentation. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-07-26 12:51:27 +00:00
--------------------------------------------------------------------------------
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
Dubious stuff
(if you break something or notice that it is broken and do not fix it yourself
- at least put it here)
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