Open by handle just grabs an inode by handle and then creates itself
a dentry for it. While this works for regular files it is horribly
broken for directories, where the VFS locking relies on the fact that
there is only just one single dentry for a given inode, and that
these are always connected to the root of the filesystem so that
it's locking algorithms work (see Documentations/filesystems/Locking)
Remove all the existing open by handle code and replace it with a small
wrapper around the exportfs code which deals with all these issues.
At the same time we also make the checks for a valid handle strict
enough to reject all not perfectly well formed handles - given that
we never hand out others that's okay and simplifies the code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
XFS has a mode called invisble I/O that doesn't update any of the
timestamps. It's used for HSM-style applications and exposed through
the nasty open by handle ioctl.
Instead of doing directly assignment of file operations that set an
internal flag for it add a new FMODE_NOCMTIME flag that we can check
in the normal file operations.
(addition of the generic VFS flag has been ACKed by Al as an interims
solution)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
The recent compat patches make xfs_file.c include xfs_ioctl32.h unconditional,
which breaks the build on 32 bit systems which don't have the various compat
defintions.
Remove the include and move the defintion of xfs_file_compat_ioctl to
xfs_ioctl.h so that we can avoid including all the compat defintions in
xfs_file.c
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Add a compat handler for XFS_IOC_ATTRMULTI_BY_HANDLE
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Create a new xfs_ioctl.h file which has prototypes for
ioctl helpers that may be called in compat mode.
Change several compat ioctl cases which are IOW to simply copy
in the userspace argument, then call the common ioctl helper.
This also fixes xfs_compat_ioc_fsgeometry_v1(), which had
it backwards before; it copied in an (empty) arg, then copied
out the native result, which probably corrupted userspace. It
should be translating on the copyout.
Also, a bit of formatting cleanup for consistency, and conversion
of all error returns to use XFS_ERROR().
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
