NFS: Revert "NFS: Move the flock open mode check into nfs_flock()"

Commit e12937279c "NFS: Move the flock open mode check into nfs_flock()"
changed NFSv3 behavior for flock() such that the open mode must match the
lock type, however that requirement shouldn't be enforced for flock().

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Cc: stable@vger.kernel.org # v4.12
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Benjamin Coddington 2017-11-10 06:27:49 -05:00 committed by Anna Schumaker
parent f02fee227e
commit fcfa447062
2 changed files with 16 additions and 16 deletions

View File

@ -829,23 +829,9 @@ int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK)
is_local = 1;
/*
* VFS doesn't require the open mode to match a flock() lock's type.
* NFS, however, may simulate flock() locking with posix locking which
* requires the open mode to match the lock type.
*/
switch (fl->fl_type) {
case F_UNLCK:
/* We're simulating flock() locks using posix locks on the server */
if (fl->fl_type == F_UNLCK)
return do_unlk(filp, cmd, fl, is_local);
case F_RDLCK:
if (!(filp->f_mode & FMODE_READ))
return -EBADF;
break;
case F_WRLCK:
if (!(filp->f_mode & FMODE_WRITE))
return -EBADF;
}
return do_setlk(filp, cmd, fl, is_local);
}
EXPORT_SYMBOL_GPL(nfs_flock);

View File

@ -6709,6 +6709,20 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
!test_bit(NFS_STATE_POSIX_LOCKS, &state->flags))
return -ENOLCK;
/*
* Don't rely on the VFS having checked the file open mode,
* since it won't do this for flock() locks.
*/
switch (request->fl_type) {
case F_RDLCK:
if (!(filp->f_mode & FMODE_READ))
return -EBADF;
break;
case F_WRLCK:
if (!(filp->f_mode & FMODE_WRITE))
return -EBADF;
}
status = nfs4_set_lock_state(state, request);
if (status != 0)
return status;