nfsd: don't hold ls_mutex across a layout recall

We do need to serialize layout stateid morphing operations, but we
currently hold the ls_mutex across a layout recall which is pretty
ugly. It's also unnecessary -- once we've bumped the seqid and
copied it, we don't need to serialize the rest of the CB_LAYOUTRECALL
vs. anything else. Just drop the mutex once the copy is done.

This was causing a "workqueue leaked lock or atomic" warning and an
occasional deadlock.

There's more work to be done here but this fixes the immediate
regression.

Fixes: cc8a55320b "nfsd: serialize layout stateid morphing operations"
Cc: stable@vger.kernel.org
Reported-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Jeff Layton 2015-11-29 08:46:14 -05:00 committed by J. Bruce Fields
parent 8005c49d9a
commit be20aa00c6

View File

@ -616,6 +616,7 @@ nfsd4_cb_layout_prepare(struct nfsd4_callback *cb)
mutex_lock(&ls->ls_mutex);
nfs4_inc_and_copy_stateid(&ls->ls_recall_sid, &ls->ls_stid);
mutex_unlock(&ls->ls_mutex);
}
static int
@ -659,7 +660,6 @@ nfsd4_cb_layout_release(struct nfsd4_callback *cb)
trace_layout_recall_release(&ls->ls_stid.sc_stateid);
mutex_unlock(&ls->ls_mutex);
nfsd4_return_all_layouts(ls, &reaplist);
nfsd4_free_layouts(&reaplist);
nfs4_put_stid(&ls->ls_stid);