In exfat, not only the newly allocated space will be mapped as
the new buffer, but also the space between ->valid_size and the
file size will be mapped as the new buffer. If the buffer is
mapped as new in ->write_begin(), it will be zeroed. But if the
buffer has been mapped as new before ->write_begin(), ->write_begin()
will not zero them, resulting in access to uninitialized data.
So this commit uses folio_zero_new_buffers() to zero the new buffers
after ->write_begin().
Fixes: 6630ea4910 ("exfat: move extend valid_size into ->page_mkwrite()")
Reported-by: syzbot+91ae49e1c1a2634d20c0@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=91ae49e1c1a2634d20c0
Tested-by: syzbot+91ae49e1c1a2634d20c0@syzkaller.appspotmail.com
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
If the file system is corrupted so that a cluster is linked to
itself in the cluster chain, and there is an unused directory
entry in the cluster, 'dentry' will not be incremented, causing
condition 'dentry < max_dentries' unable to prevent an infinite
loop.
This infinite loop causes s_lock not to be released, and other
tasks will hang, such as exfat_sync_fs().
This commit stops traversing the cluster chain when there is unused
directory entry in the cluster to avoid this infinite loop.
Reported-by: syzbot+205c2644abdff9d3f9fc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=205c2644abdff9d3f9fc
Tested-by: syzbot+205c2644abdff9d3f9fc@syzkaller.appspotmail.com
Fixes: ca06197382 ("exfat: add directory operations")
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
In __exfat_free_cluster(), the cluster chain is traversed until the
EOF cluster. If the cluster chain includes a loop due to file system
corruption, the EOF cluster cannot be traversed, resulting in an
infinite loop.
To avoid this infinite loop, this commit changes to only traverse and
free the number of clusters indicated by the file size.
Reported-by: syzbot+1de5a37cb85a2d536330@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1de5a37cb85a2d536330
Tested-by: syzbot+1de5a37cb85a2d536330@syzkaller.appspotmail.com
Fixes: 31023864e6 ("exfat: add fat entry operations")
Suggested-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
On failure, "dentry" is the error code. If the error code indicates
that there is no space, a new cluster may need to be allocated; for
other errors, it should be returned directly.
Only on success, "dentry" is the index of the directory entry, and
it needs to be converted into the directory entry index within the
cluster where it is located.
Fixes: 8a3f5711ad ("exfat: reduce FAT chain traversal")
Reported-by: syzbot+6f6c9397e0078ef60bce@syzkaller.appspotmail.com
Tested-by: syzbot+6f6c9397e0078ef60bce@syzkaller.appspotmail.com
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Before this commit, ->dir and ->entry of exfat_inode_info record the
first cluster of the parent directory and the directory entry index
starting from this cluster.
The directory entry set will be gotten during write-back-inode/rmdir/
unlink/rename. If the clusters of the parent directory are not
continuous, the FAT chain will be traversed from the first cluster of
the parent directory to find the cluster where ->entry is located.
After this commit, ->dir records the cluster where the first directory
entry in the directory entry set is located, and ->entry records the
directory entry index in the cluster, so that there is almost no need
to access the FAT when getting the directory entry set.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Daniel Palmer <daniel.palmer@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
For the root directory and other directories, the clusters
allocated to them can be obtained from exfat_inode_info, and
there is no need to distinguish them.
And there is no need to initialize atime/ctime/mtime/size in
exfat_readdir(), because exfat_iterate() does not use them.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Daniel Palmer <daniel.palmer@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
The output of argument 'p_dir' of exfat_add_entry() is not used
in either exfat_mkdir() or exfat_create(), remove the argument.
Code refinement, no functional changes.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Daniel Palmer <daniel.palmer@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
__exfat_resolve_path() mixes two functions. The first one is to
resolve and check if the path is valid. The second one is to output
the cluster assigned to the directory.
The second one is only needed when need to traverse the directory
entries, and calling exfat_chain_set() so early causes p_dir to be
passed as an argument multiple times, increasing the complexity of
the code.
This commit moves the call to exfat_chain_set() before traversing
directory entries.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Daniel Palmer <daniel.palmer@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
This helper gets the directory entry set of the file for the exfat
inode which has been created.
It's used to remove all the instances of the pattern it replaces
making the code cleaner, it's also a preparation for changing ->dir
to record the cluster where the directory entry set is located and
changing ->entry to record the index of the directory entry within
the cluster.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Daniel Palmer <daniel.palmer@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
In this exfat implementation, the relationship between inode and ei
is ei=EXFAT_I(inode). However, in the arguments of exfat_move_file()
and exfat_rename_file(), argument 'inode' indicates the parent
directory, but argument 'ei' indicates the target file to be renamed.
They do not have the above relationship, which is not friendly to code
readers.
So this commit renames 'inode' to 'parent_inode', making the argument
name match its role.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
To determine whether it is a directory, there is no need to read its
directory entry, just use S_ISDIR(inode->i_mode).
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Daniel Palmer <daniel.palmer@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Unaligned direct writes are invalid and should return an error
without making any changes, rather than extending ->valid_size
and then returning an error. Therefore, alignment checking is
required before extending ->valid_size.
Fixes: 11a347fb6c ("exfat: change to get file size from DataLength")
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Co-developed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
There is no check if stream size and start_clu are invalid.
If start_clu is EOF cluster and stream size is 4096, It will
cause uninit value access. because ei->hint_femp.eidx could
be 128(if cluster size is 4K) and wrong hint will allocate
next cluster. and this cluster will be same with the cluster
that is allocated by exfat_extend_valid_size(). The previous
patch will check invalid start_clu, but for clarity, initialize
hint_femp.eidx to zero.
Cc: stable@vger.kernel.org
Reported-by: syzbot+01218003be74b5e1213a@syzkaller.appspotmail.com
Tested-by: syzbot+01218003be74b5e1213a@syzkaller.appspotmail.com
Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
In the case of the directory size is greater than or equal to
the cluster size, if start_clu becomes an EOF cluster(an invalid
cluster) due to file system corruption, then the directory entry
where ei->hint_femp.eidx hint is outside the directory, resulting
in an out-of-bounds access, which may cause further file system
corruption.
This commit adds a check for start_clu, if it is an invalid cluster,
the file or directory will be treated as empty.
Cc: stable@vger.kernel.org
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Co-developed-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.
auto-generated by the following:
for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
If exfat_load_upcase_table reaches end and returns -EINVAL,
allocated memory doesn't get freed and while
exfat_load_default_upcase_table allocates more memory, leading to a
memory leak.
Here's link to syzkaller crash report illustrating this issue:
https://syzkaller.appspot.com/text?tag=CrashReport&x=1406c201980000
Reported-by: syzbot+e1c69cadec0f1a078e3d@syzkaller.appspotmail.com
Fixes: a13d1a4de3 ("exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper")
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Yang <danielyangkang@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
It is not a good way to extend valid_size to the end of the
mmap area by writing zeros in mmap. Because after calling mmap,
no data may be written, or only a small amount of data may be
written to the head of the mmap area.
This commit moves extending valid_size to exfat_page_mkwrite().
In exfat_page_mkwrite() only extend valid_size to the starting
position of new data writing, which reduces unnecessary writing
of zeros.
If the block is not mapped and is marked as new after being
mapped for writing, block_write_begin() will zero the page
cache corresponding to the block, so there is no need to call
zero_user_segment() in exfat_file_zeroed_range(). And after moving
extending valid_size to exfat_page_mkwrite(), the data written by
mmap will be copied to the page cache but the page cache may be
not mapped to the disk. Calling zero_user_segment() will cause
the data written by mmap to be cleared. So this commit removes
calling zero_user_segment() from exfat_file_zeroed_range() and
renames exfat_file_zeroed_range() to exfat_extend_valid_size().
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
If the first directory entry in the root directory is not a bitmap
directory entry, 'bh' will not be released and reassigned, which
will cause a memory leak.
Fixes: 1e49a94cf7 ("exfat: add bitmap operations")
Cc: stable@vger.kernel.org
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
We found that when writing a large file through buffer write, if the
disk is inaccessible, exFAT does not return an error normally, which
leads to the writing process not stopping properly.
To easily reproduce this issue, you can follow the steps below:
1. format a device to exFAT and then mount (with a full disk erase)
2. dd if=/dev/zero of=/exfat_mount/test.img bs=1M count=8192
3. eject the device
You may find that the dd process does not stop immediately and may
continue for a long time.
The root cause of this issue is that during buffer write process,
exFAT does not need to access the disk to look up directory entries
or the FAT table (whereas FAT would do) every time data is written.
Instead, exFAT simply marks the buffer as dirty and returns,
delegating the writeback operation to the writeback process.
If the disk cannot be accessed at this time, the error will only be
returned to the writeback process, and the original process will not
receive the error, so it cannot be returned to the user side.
When the disk cannot be accessed normally, an error should be returned
to stop the writing process.
Implement sops->shutdown and ioctl to shut down the file system
when underlying block device is marked dead.
Signed-off-by: Dongliang Cui <dongliang.cui@unisoc.com>
Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
After commit(11a347fb6c exfat: change to get file size from
DataLength), the remaining area or hole had been filled with
zeros before calling exfat_direct_IO(), so there is no need to
fallback to buffered write, and ->i_size_aligned is no longer
needed, drop it.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
->i_size_ondisk is no longer used by exfat_write_begin() after
commit(11a347fb6c exfat: change to get file size from DataLength),
drop it.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
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>
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>
When accessing a file with more entries than ES_MAX_ENTRY_NUM, the bh-array
is allocated in __exfat_get_entry_set. The problem is that the bh-array is
allocated with GFP_KERNEL. It does not make sense. In the following cases,
a deadlock for sbi->s_lock between the two processes may occur.
CPU0 CPU1
---- ----
kswapd
balance_pgdat
lock(fs_reclaim)
exfat_iterate
lock(&sbi->s_lock)
exfat_readdir
exfat_get_uniname_from_ext_entry
exfat_get_dentry_set
__exfat_get_dentry_set
kmalloc_array
...
lock(fs_reclaim)
...
evict
exfat_evict_inode
lock(&sbi->s_lock)
To fix this, let's allocate bh-array with GFP_NOFS.
Fixes: a3ff29a95f ("exfat: support dynamic allocate bh for exfat_entry_set_cache")
Cc: stable@vger.kernel.org # v6.2+
Reported-by: syzbot+412a392a2cd4a65e71db@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/000000000000fef47e0618c0327f@google.com
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Pass the idmapped mount information to the different helper
functions. Adapt the uid/gid checks in exfat_setattr to use the
vfsuid/vfsgid helpers.
Based on the fat implementation in commit 4b78993681
("fat: handle idmapped mounts") by Christian Brauner.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
From exFAT specification, the reserved fields should initialize
to zero and should not use for any purpose.
If create a new dentry set in the UNUSED dentries, all fields
had been zeroed when allocating cluster to parent directory.
But if create a new dentry set in the DELETED dentries, the
reserved fields in file and stream extension dentries may be
non-zero. Because only the valid bit of the type field of the
dentry is cleared in exfat_remove_entries(), if the type of
dentry is different from the original(For example, a dentry that
was originally a file name dentry, then set to deleted dentry,
and then set as a file dentry), the reserved fields is non-zero.
So this commit initializes the dentry to 0 before createing file
dentry and stream extension dentry.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Commit(f55c096f62 exfat: do not zero the extended part) changed
the timing of synchronizing bitmap and inode in exfat_cont_expand().
The change caused xfstests generic/013 to fail if 'dirsync' or 'sync'
is enabled. So this commit restores the timing.
Fixes: f55c096f62 ("exfat: do not zero the extended part")
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
- Improve dirsync performance by syncing on a dentry-set rather than
on a per-directory entry
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Merge tag 'exfat-for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat
Pull exfat updates from Namjae Jeon:
- Improve dirsync performance by syncing on a dentry-set rather than on
a per-directory entry
* tag 'exfat-for-6.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat:
exfat: remove duplicate update parent dir
exfat: do not sync parent dir if just update timestamp
exfat: remove unused functions
exfat: convert exfat_find_empty_entry() to use dentry cache
exfat: convert exfat_init_ext_entry() to use dentry cache
exfat: move free cluster out of exfat_init_ext_entry()
exfat: convert exfat_remove_entries() to use dentry cache
exfat: convert exfat_add_entry() to use dentry cache
exfat: add exfat_get_empty_dentry_set() helper
exfat: add __exfat_get_dentry_set() helper
For renaming, the directory only needs to be updated once if it
is in the same directory.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
When sync or dir_sync is enabled, there is no need to sync the
parent directory's inode if only for updating its timestamp.
1. If an unexpected power failure occurs, the timestamp of the
parent directory is not updated to the storage, which has no
impact on the user.
2. The number of writes will be greatly reduced, which can not
only improve performance, but also prolong device life.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
exfat_count_ext_entries() is no longer called, remove it.
exfat_update_dir_chksum() is no longer called, remove it and
rename exfat_update_dir_chksum_with_entry_set() to it.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Before this conversion, each dentry traversed needs to be read
from the storage device or page cache. There are at least 16
dentries in a sector. This will result in frequent page cache
searches.
After this conversion, if all directory entries in a sector are
used, the sector only needs to be read once.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Before this conversion, in exfat_init_ext_entry(), to init
the dentries in a dentry set, the sync times is equals the
dentry number if 'dirsync' or 'sync' is enabled.
That affects not only performance but also device life.
After this conversion, only needs to be synchronized once if
'dirsync' or 'sync' is enabled.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
exfat_init_ext_entry() is an init function, it's a bit strange
to free cluster in it. And the argument 'inode' will be removed
from exfat_init_ext_entry(). So this commit changes to free the
cluster in exfat_remove_entries().
Code refinement, no functional changes.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Before this conversion, in exfat_remove_entries(), to mark the
dentries in a dentry set as deleted, the sync times is equals
the dentry numbers if 'dirsync' or 'sync' is enabled.
That affects not only performance but also device life.
After this conversion, only needs to be synchronized once if
'dirsync' or 'sync' is enabled.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
After this conversion, if "dirsync" or "sync" is enabled, the
number of synchronized dentries in exfat_add_entry() will change
from 2 to 1.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
This helper is used to lookup empty dentry set. If there are
no enough empty dentries at the input location, this helper will
return the number of dentries that need to be skipped for the
next lookup.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Since exfat_get_dentry_set() invokes the validate functions of
exfat_validate_entry(), it only supports getting a directory
entry set of an existing file, doesn't support getting an empty
entry set.
To remove the limitation, add this helper.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Yes, yes, I know the slab people were planning on going slow and letting
every subsystem fight this thing on their own. But let's just rip off
the band-aid and get it over and done with. I don't want to see a
number of unnecessary pull requests just to get rid of a flag that no
longer has any meaning.
This was mainly done with a couple of 'sed' scripts and then some manual
cleanup of the end result.
Link: https://lore.kernel.org/all/CAHk-=wji0u+OOtmAOD-5JV3SXcRJF___k_+8XNKmak0yd5vW1Q@mail.gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
pathwalk. This series is a result of code audit (the second round
of it) and it should deal with most of that stuff. Exceptions: ntfs3
->d_hash()/->d_compare() and ceph_d_revalidate(). Up to maintainers (a
note for NTFS folks - when documentation says that a method may not block,
it *does* imply that blocking allocations are to be avoided. Really).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull RCU pathwalk fixes from Al Viro:
"We still have some races in filesystem methods when exposed to RCU
pathwalk. This series is a result of code audit (the second round of
it) and it should deal with most of that stuff.
Still pending: ntfs3 ->d_hash()/->d_compare() and ceph_d_revalidate().
Up to maintainers (a note for NTFS folks - when documentation says
that a method may not block, it *does* imply that blocking allocations
are to be avoided. Really)"
[ More explanations for people who aren't familiar with the vagaries of
RCU path walking: most of it is hidden from filesystems, but if a
filesystem actively participates in the low-level path walking it
needs to make sure the fields involved in that walk are RCU-safe.
That "actively participate in low-level path walking" includes things
like having its own ->d_hash()/->d_compare() routines, or by having
its own directory permission function that doesn't just use the common
helpers. Having a ->d_revalidate() function will also have this issue.
Note that instead of making everything RCU safe you can also choose to
abort the RCU pathwalk if your operation cannot be done safely under
RCU, but that obviously comes with a performance penalty. One common
pattern is to allow the simple cases under RCU, and abort only if you
need to do something more complicated.
So not everything needs to be RCU-safe, and things like the inode etc
that the VFS itself maintains obviously already are. But these fixes
tend to be about properly RCU-delaying things like ->s_fs_info that
are maintained by the filesystem and that got potentially released too
early. - Linus ]
* tag 'pull-fixes.pathwalk-rcu-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ext4_get_link(): fix breakage in RCU mode
cifs_get_link(): bail out in unsafe case
fuse: fix UAF in rcu pathwalks
procfs: make freeing proc_fs_info rcu-delayed
procfs: move dropping pde and pid from ->evict_inode() to ->free_inode()
nfs: fix UAF on pathwalk running into umount
nfs: make nfs_set_verifier() safe for use in RCU pathwalk
afs: fix __afs_break_callback() / afs_drop_open_mmap() race
hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info
exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper
affs: free affs_sb_info with kfree_rcu()
rcu pathwalk: prevent bogus hard errors from may_lookup()
fs/super.c: don't drop ->s_user_ns until we free struct super_block itself
That stuff can be accessed by ->d_hash()/->d_compare(); as it is, we have
a hard-to-hit UAF if rcu pathwalk manages to get into ->d_hash() on a filesystem
that is in process of getting shut down.
Besides, having nls and upcase table cleanup moved from ->put_super() towards
the place where sbi is freed makes for simpler failure exits.
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Eric Hong found that when using ftruncate to expand an empty file,
exfat_ent_set() will fail if discontinuous clusters are allocated.
The reason is that the empty file does not have a cluster chain,
but exfat_ent_set() attempts to append the newly allocated cluster
to the cluster chain. In addition, exfat_find_last_cluster() only
supports finding the last cluster in a non-empty file.
So this commit adds a check whether the file is empty. If the file
is empty, exfat_find_last_cluster() and exfat_ent_set() are no longer
called as they do not need to be called.
Fixes: f55c096f62 ("exfat: do not zero the extended part")
Reported-by: Eric Hong <erichong@qnap.com>
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
For dio read, bio will be leave in flight when a successful partial
aio read have been setup, blockdev_direct_IO() will return
-EIOCBQUEUED. In the case, iter->iov_offset will be not advanced,
the oops reported by syzbot will occur if revert iter->iov_offset
with iov_iter_revert(). The unwritten part had been zeroed by aio
read, so there is no need to zero it in dio read.
Reported-by: syzbot+fd404f6b03a58e8bc403@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=fd404f6b03a58e8bc403
Fixes: 11a347fb6c ("exfat: change to get file size from DataLength")
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Since the read operation beyond the ValidDataLength returns zero,
if we just extend the size of the file, we don't need to zero the
extended part, but only change the DataLength without changing
the ValidDataLength.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
In stream extension directory entry, the ValidDataLength
field describes how far into the data stream user data has
been written, and the DataLength field describes the file
size.
Signed-off-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Reviewed-by: Andy Wu <Andy.Wu@sony.com>
Reviewed-by: Aoyama Wataru <wataru.aoyama@sony.com>
Reviewed-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Replaced the internal table lookup algorithm with ffs of
the bitops library with better performance.
Use it to increase the single processing length of the
exfat_find_free_bitmap function, from single-byte search to long type.
Signed-off-by: John Sanpe <sanpeqf@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Replace the internal table lookup algorithm with the hweight
library, which has instruction set acceleration capabilities.
Use it to increase the length of a single calculation of
the exfat_find_free_bitmap function to the long type.
Signed-off-by: John Sanpe <sanpeqf@gmail.com>
Acked-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
