Kernel/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2024-12-28 16:53:49 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

ovl: allocate a container struct ovl_file for ovl private context

Browse Source 
Instead of using ->private_data to point at realfile directly, so
that we can add more context per ovl open file.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
This commit is contained in:
Amir Goldstein 2024-10-07 15:22:29 +02:00
parent c2c54b5f34
commit 87a8a76c34
3 changed files with 48 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
fs/overlayfs/dir.c
View File

@ -1323,6 +1323,7 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,
const struct cred *old_cred, *new_cred = NULL;
struct path realparentpath;
struct file *realfile;
struct ovl_file *of;
struct dentry *newdentry;
/* It's okay to set O_NOATIME, since the owner will be current fsuid */
int flags = file->f_flags | OVL_OPEN_FLAGS;
@ -1344,14 +1345,21 @@ static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,
if (err)
goto out_revert_creds;
of = ovl_file_alloc(realfile);
if (!of) {
fput(realfile);
err = -ENOMEM;
goto out_revert_creds;
}
/* ovl_instantiate() consumes the newdentry reference on success */
newdentry = dget(realfile->f_path.dentry);
err = ovl_instantiate(dentry, inode, newdentry, false, file);
if (!err) {
file->private_data = realfile;
file->private_data = of;
} else {
dput(newdentry);
fput(realfile);
ovl_file_free(of);
}
out_revert_creds:
ovl_revert_creds(old_cred);
@ -1407,7 +1415,7 @@ static int ovl_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
put_realfile:
/* Without FMODE_OPENED ->release() won't be called on @file */
if (!(file->f_mode & FMODE_OPENED))
fput(file->private_data);
ovl_file_free(file->private_data);
put_inode:
iput(inode);
drop_write:

40
fs/overlayfs/file.c
View File

@ -89,10 +89,32 @@ static int ovl_change_flags(struct file *file, unsigned int flags)
return 0;
}
struct ovl_file {
struct file *realfile;
};
struct ovl_file *ovl_file_alloc(struct file *realfile)
{
struct ovl_file *of = kzalloc(sizeof(struct ovl_file), GFP_KERNEL);
if (unlikely(!of))
return NULL;
of->realfile = realfile;
return of;
}
void ovl_file_free(struct ovl_file *of)
{
fput(of->realfile);
kfree(of);
}
static int ovl_real_fdget_path(const struct file *file, struct fd *real,
struct path *realpath)
{
struct file *realfile = file->private_data;
struct ovl_file *of = file->private_data;
struct file *realfile = of->realfile;
real->word = (unsigned long)realfile;
@ -144,6 +166,7 @@ static int ovl_open(struct inode *inode, struct file *file)
struct dentry *dentry = file_dentry(file);
struct file *realfile;
struct path realpath;
struct ovl_file *of;
int err;
/* lazy lookup and verify lowerdata */
@ -166,15 +189,20 @@ static int ovl_open(struct inode *inode, struct file *file)
if (IS_ERR(realfile))
return PTR_ERR(realfile);
file->private_data = realfile;
of = ovl_file_alloc(realfile);
if (!of) {
fput(realfile);
return -ENOMEM;
}
file->private_data = of;
return 0;
}
static int ovl_release(struct inode *inode, struct file *file)
{
fput(file->private_data);
ovl_file_free(file->private_data);
return 0;
}
@ -426,13 +454,13 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
{
struct file *realfile = file->private_data;
struct ovl_file *of = file->private_data;
struct backing_file_ctx ctx = {
.cred = ovl_creds(file_inode(file)->i_sb),
.accessed = ovl_file_accessed,
};
return backing_file_mmap(realfile, vma, &ctx);
return backing_file_mmap(of->realfile, vma, &ctx);
}
static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)

3
fs/overlayfs/overlayfs.h
View File

@ -863,6 +863,9 @@ int ovl_real_fileattr_set(const struct path *realpath, struct fileattr *fa);
int ovl_fileattr_get(struct dentry *dentry, struct fileattr *fa);
int ovl_fileattr_set(struct mnt_idmap *idmap,
struct dentry *dentry, struct fileattr *fa);
struct ovl_file;
struct ovl_file *ovl_file_alloc(struct file *realfile);
void ovl_file_free(struct ovl_file *of);
/* copy_up.c */
int ovl_copy_up(struct dentry *dentry);