If there is a lock resource conflict on multiple nodes, the lock on
convert queue may not be granted forever.
EX.)
grant queue:
node0 grmode NL / rqmode IV
node1 grmode NL / rqmode IV
convert queue:
node2 grmode NL / rqmode EX
node3 grmode PR / rqmode EX
wait queue:
node4 grmode IV / rqmode PR
node5 grmode IV / rqmode PR
When the lock conversion (node PR -> NL) of node 0 is completed, the lock
of node 2 should be grantable. However, __can_be_granted() returns 0
because the grmode of the lock on node 3 in convert queue is PR.
When checking the lock at the head of convert queue, exclude
queue_conflict() targeting convert queue.
Signed-off-by: Tadashi Miyauchi <miyau...@toshiba-tops.co.jp>
Signed-off-by: Tsutomu Owa <tsutomu....@toshiba.co.jp>
---
fs/dlm/lock.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 35502d4..dcdd26d 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -2336,7 +2336,8 @@ static int _can_be_granted(struct dlm_rsb *r, struct
dlm_lkb *lkb, int now,
* locks
*/
- if (queue_conflict(&r->res_convertqueue, lkb))
+ if (!first_in_list(lkb, &r->res_convertqueue) &&
+ queue_conflict(&r->res_convertqueue, lkb))
return 0;
/*
--
2.7.4
