On Fri, Nov 1, 2024 at 10:30 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> On Fri, Nov 01, 2024 at 03:37:03PM -0400, Stefan Berger wrote:
> > From: Stefan Berger <stefanb@xxxxxxxxxxxxx>
> >
> > Commit 8a924db2d7b5 ("fs: Pass AT_GETATTR_NOSEC flag to getattr interface
> > function")' introduced the AT_GETATTR_NOSEC flag to ensure that the
> > call paths only call vfs_getattr_nosec if it is set instead of vfs_getattr.
> > Now, simplify the getattr interface functions of filesystems where the flag
> > AT_GETATTR_NOSEC is checked.
> >
> > There is only a single caller of inode_operations getattr function and it
> > is located in fs/stat.c in vfs_getattr_nosec. The caller there is the only
> > one from which the AT_GETATTR_NOSEC flag is passed from.
> >
> > Two filesystems are checking this flag in .getattr and the flag is always
> > passed to them unconditionally from only vfs_getattr_nosec:
> >
> > - ecryptfs: Simplify by always calling vfs_getattr_nosec in
> > ecryptfs_getattr. From there the flag is passed to no other
> > function and this function is not called otherwise.
> >
> > - overlayfs: Simplify by always calling vfs_getattr_nosec in
> > ovl_getattr. From there the flag is passed to no other
> > function and this function is not called otherwise.
> >
> > The query_flags in vfs_getattr_nosec will mask-out AT_GETATTR_NOSEC from
> > any caller using AT_STATX_SYNC_TYPE as mask so that the flag is not
> > important inside this function. Also, since no filesystem is checking the
> > flag anymore, remove the flag entirely now, including the BUG_ON check that
> > never triggered.
> >
> > The net change of the changes here combined with the originan commit is
> > that ecryptfs and overlayfs do not call vfs_getattr but only
> > vfs_getattr_nosec.
> >
> > Fixes: 8a924db2d7b5 ("fs: Pass AT_GETATTR_NOSEC flag to getattr interface function")
> > Reported-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> > Closes: https://lore.kernel.org/linux-fsdevel/20241101011724.GN1350452@ZenIV/T/#u
> > Cc: Tyler Hicks <code@xxxxxxxxxxx>
> > Cc: ecryptfs@xxxxxxxxxxxxxxx
> > Cc: Miklos Szeredi <miklos@xxxxxxxxxx>
> > Cc: Amir Goldstein <amir73il@xxxxxxxxx>
> > Cc: linux-unionfs@xxxxxxxxxxxxxxx
> > Cc: Christian Brauner <brauner@xxxxxxxxxx>
> > Cc: linux-fsdevel@xxxxxxxxxxxxxxx
> > Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
>
> Applied (viro/vfs.git#work.statx2)
Acked-by: Amir Goldstein <amir73il@xxxxxxxxx>
