CIFS: Fix lock consistensy bug in cifs_setlk

If we netogiate mandatory locking style, have a read lock and try
to set a write lock we end up with a write lock in vfs cache and
no lock in cifs lock cache - that's wrong. Fix it by returning
from cifs_setlk immediately if a error occurs during setting a lock.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 67fe0b811f2..bceffa8c034 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1443,16 +1443,18 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
                         return -ENOMEM;
 
                 rc = cifs_lock_add_if(cfile, lock, wait_flag);
-                if (rc < 0)
+                if (rc < 0) {
                         kfree(lock);
-                if (rc <= 0)
+                        return rc;
+                }
+                if (!rc)
                         goto out;
 
                 rc = server->ops->mand_lock(xid, cfile, flock->fl_start, length,
                                             type, 1, 0, wait_flag);
                 if (rc) {
                         kfree(lock);
-                        goto out;
+                        return rc;
                 }
 
                 cifs_lock_add(cfile, lock);