[GFS2] Use list_for_each_entry_safe_reverse in gfs2_ail1_start()
This is an attempt to fix Red Hat bz 204364. I don't hit it all
the time, but with these changes, running postmark which used to
trigger it on a regular basis no longer appears to. So I'm not
saying that its 100% certain that its fixed, but it does look
promising at the moment.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 08b80b2..6112d64 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -62,8 +62,9 @@
{
struct list_head *head = &sdp->sd_ail1_list;
u64 sync_gen;
- struct list_head *first, *tmp;
- struct gfs2_ail *first_ai, *ai;
+ struct list_head *first;
+ struct gfs2_ail *first_ai, *ai, *tmp;
+ int done = 0;
gfs2_log_lock(sdp);
if (list_empty(head)) {
@@ -75,27 +76,25 @@
first = head->prev;
first_ai = list_entry(first, struct gfs2_ail, ai_list);
first_ai->ai_sync_gen = sync_gen;
- gfs2_ail1_start_one(sdp, first_ai);
+ gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */
if (flags & DIO_ALL)
first = NULL;
- for (;;) {
+ while(!done) {
if (first && (head->prev != first ||
gfs2_ail1_empty_one(sdp, first_ai, 0)))
break;
- for (tmp = head->prev; tmp != head; tmp = tmp->prev) {
- ai = list_entry(tmp, struct gfs2_ail, ai_list);
+ done = 1;
+ list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) {
if (ai->ai_sync_gen >= sync_gen)
continue;
ai->ai_sync_gen = sync_gen;
- gfs2_ail1_start_one(sdp, ai);
+ gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
+ done = 0;
break;
}
-
- if (tmp == head)
- break;
}
gfs2_log_unlock(sdp);