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authortsutomu.owa@toshiba.co.jp <tsutomu.owa@toshiba.co.jp>2017-09-15 14:17:23 -0500
committerDavid Teigland <teigland@redhat.com>2017-09-25 12:45:21 -0500
commit294e7e458763dc1d229cbbe7147a6034bfc6e39a (patch)
tree5b5d3cda6d51e5f5c8a4817b7f4446a2c181515f
parent173a31fe2b23b3ccc45d0b70edb225b1d836c31d (diff)
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DLM: fix conversion deadlock when DLM_LKF_NODLCKWT flag is set
When the DLM_LKF_NODLCKWT flag was set, even if conversion deadlock was detected, the caller of can_be_granted() was unknown. We change the behavior of can_be_granted() and change it to detect conversion deadlock regardless of whether the DLM_LKF_NODLCKWT flag is set or not. And depending on whether the DLM_LKF_NODLCKWT flag is set or not, we change the behavior at the caller of can_be_granted(). This fix has no effect except when using DLM_LKF_NODLCKWT flag. Currently, ocfs2 uses the DLM_LKF_NODLCKWT flag and does not expect a cancel operation from conversion deadlock when calling dlm_lock(). ocfs2 is implemented to perform a cancel operation by requesting BASTs (callback). Signed-off-by: Tadashi Miyauchi <miyauchi@toshiba-tops.co.jp> Signed-off-by: Tsutomu Owa <tsutomu.owa@toshiba.co.jp> Signed-off-by: David Teigland <teigland@redhat.com>
-rw-r--r--fs/dlm/lock.c42
1 files changed, 23 insertions, 19 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index d4aaddec1b16..f145a2a9d6cb 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -2465,14 +2465,12 @@ static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
if (lkb->lkb_exflags & DLM_LKF_CONVDEADLK) {
lkb->lkb_grmode = DLM_LOCK_NL;
lkb->lkb_sbflags |= DLM_SBF_DEMOTED;
- } else if (!(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
- if (err)
- *err = -EDEADLK;
- else {
- log_print("can_be_granted deadlock %x now %d",
- lkb->lkb_id, now);
- dlm_dump_rsb(r);
- }
+ } else if (err) {
+ *err = -EDEADLK;
+ } else {
+ log_print("can_be_granted deadlock %x now %d",
+ lkb->lkb_id, now);
+ dlm_dump_rsb(r);
}
goto out;
}
@@ -2501,13 +2499,6 @@ static int can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now,
return rv;
}
-/* FIXME: I don't think that can_be_granted() can/will demote or find deadlock
- for locks pending on the convert list. Once verified (watch for these
- log_prints), we should be able to just call _can_be_granted() and not
- bother with the demote/deadlk cases here (and there's no easy way to deal
- with a deadlk here, we'd have to generate something like grant_lock with
- the deadlk error.) */
-
/* Returns the highest requested mode of all blocked conversions; sets
cw if there's a blocked conversion to DLM_LOCK_CW. */
@@ -2545,9 +2536,22 @@ static int grant_pending_convert(struct dlm_rsb *r, int high, int *cw,
}
if (deadlk) {
- log_print("WARN: pending deadlock %x node %d %s",
- lkb->lkb_id, lkb->lkb_nodeid, r->res_name);
- dlm_dump_rsb(r);
+ /*
+ * If DLM_LKB_NODLKWT flag is set and conversion
+ * deadlock is detected, we request blocking AST and
+ * down (or cancel) conversion.
+ */
+ if (lkb->lkb_exflags & DLM_LKF_NODLCKWT) {
+ if (lkb->lkb_highbast < lkb->lkb_rqmode) {
+ queue_bast(r, lkb, lkb->lkb_rqmode);
+ lkb->lkb_highbast = lkb->lkb_rqmode;
+ }
+ } else {
+ log_print("WARN: pending deadlock %x node %d %s",
+ lkb->lkb_id, lkb->lkb_nodeid,
+ r->res_name);
+ dlm_dump_rsb(r);
+ }
continue;
}
@@ -3123,7 +3127,7 @@ static int do_convert(struct dlm_rsb *r, struct dlm_lkb *lkb)
deadlock, so we leave it on the granted queue and return EDEADLK in
the ast for the convert. */
- if (deadlk) {
+ if (deadlk && !(lkb->lkb_exflags & DLM_LKF_NODLCKWT)) {
/* it's left on the granted queue */
revert_lock(r, lkb);
queue_cast(r, lkb, -EDEADLK);