4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Benjamin Coddington <bcodding@xxxxxxxxxx>
commit fcfa447062b2061e11f68b846d61cbfe60d0d604 upstream.
Commit e12937279c8b "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@xxxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/file.c | 18 ++----------------
fs/nfs/nfs4proc.c | 14 ++++++++++++++
2 files changed, 16 insertions(+), 16 deletions(-)
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -829,23 +829,9 @@ int nfs_flock(struct file *filp, int cmd
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);
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6568,6 +6568,20 @@ nfs4_proc_lock(struct file *filp, int cm
!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;