cifs: simplify refcounting for oplock breaks
Currently, we take a sb->s_active reference and a cifsFileInfo reference
when an oplock break workqueue job is queued. This is unnecessary and
more complicated than it needs to be. Also as Al points out,
deactivate_super has non-trivial locking implications so it's best to
avoid that if we can.
Instead, just cancel any pending oplock breaks for this filehandle
synchronously in cifsFileInfo_put after taking it off the lists.
That should ensure that this job doesn't outlive the structures it
depends on.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 03a1f49..7c16933 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -585,15 +585,8 @@
cifs_set_oplock_level(pCifsInode,
pSMB->OplockLevel ? OPLOCK_READ : 0);
- /*
- * cifs_oplock_break_put() can't be called
- * from here. Get reference after queueing
- * succeeded. cifs_oplock_break() will
- * synchronize using cifs_file_list_lock.
- */
- if (queue_work(system_nrt_wq,
- &netfile->oplock_break))
- cifs_oplock_break_get(netfile);
+ queue_work(system_nrt_wq,
+ &netfile->oplock_break);
netfile->oplock_break_cancelled = false;
spin_unlock(&cifs_file_list_lock);