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| author | Miklos Szeredi <mszeredi@redhat.com> | 2021-04-07 14:36:42 +0200 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2021-04-12 15:04:23 +0200 |
| commit | 4c5b479975212065ef39786e115fde42847e95a9 (patch) | |
| tree | fb285b479c8025061763e768c23a326edf6ec4ff /Documentation/filesystems/locking.rst | |
| parent | e49d033bddf5b565044e2abe4241353959bc9120 (diff) | |
| download | linux-stable-4c5b479975212065ef39786e115fde42847e95a9.tar.gz linux-stable-4c5b479975212065ef39786e115fde42847e95a9.tar.bz2 linux-stable-4c5b479975212065ef39786e115fde42847e95a9.zip | |
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>
Diffstat (limited to 'Documentation/filesystems/locking.rst')
| -rw-r--r-- | Documentation/filesystems/locking.rst | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst index b7dcc86c92a4..729ce492b662 100644 --- a/Documentation/filesystems/locking.rst +++ b/Documentation/filesystems/locking.rst @@ -80,13 +80,16 @@ prototypes:: struct file *, unsigned open_flag, umode_t create_mode); int (*tmpfile) (struct inode *, struct dentry *, umode_t); + int (*fileattr_set)(struct user_namespace *mnt_userns, + struct dentry *dentry, struct fileattr *fa); + int (*fileattr_get)(struct dentry *dentry, struct fileattr *fa); locking rules: all may block -============ ============================================= +============= ============================================= ops i_rwsem(inode) -============ ============================================= +============= ============================================= lookup: shared create: exclusive link: exclusive (both) @@ -107,7 +110,9 @@ fiemap: no update_time: no atomic_open: shared (exclusive if O_CREAT is set in open flags) tmpfile: no -============ ============================================= +fileattr_get: no or exclusive +fileattr_set: exclusive +============= ============================================= Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_rwsem |