NFS: Move the flock open mode check into nfs_flock()
We only need to check lock exclusive/shared types against open mode when
flock() is used on NFS, so move it into the flock-specific path instead of
checking it for all locks.
Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 6682139..b7f4af3 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -820,9 +820,23 @@ int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK)
is_local = 1;
- /* We're simulating flock() locks using posix locks on the server */
- if (fl->fl_type == F_UNLCK)
+ /*
+ * 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:
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);