[PATCH] dm snapshot: fix metadata writing when suspending
When suspending a device-mapper device, dm_suspend() sleeps until all
necessary I/O is completed. This state is triggered by a callback from
persistent_commit(). But some I/O can still be issued *after* the callback
(to prepare the next metadata area for use if the current one is full). This
patch delays the callback until after that I/O is complete.
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index 002417d..99cdffa 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -536,6 +536,16 @@
if (r)
ps->valid = 0;
+ /*
+ * Have we completely filled the current area ?
+ */
+ if (ps->current_committed == ps->exceptions_per_area) {
+ ps->current_committed = 0;
+ r = zero_area(ps, ps->current_area + 1);
+ if (r)
+ ps->valid = 0;
+ }
+
for (i = 0; i < ps->callback_count; i++) {
cb = ps->callbacks + i;
cb->callback(cb->context, r == 0 ? 1 : 0);
@@ -543,16 +553,6 @@
ps->callback_count = 0;
}
-
- /*
- * Have we completely filled the current area ?
- */
- if (ps->current_committed == ps->exceptions_per_area) {
- ps->current_committed = 0;
- r = zero_area(ps, ps->current_area + 1);
- if (r)
- ps->valid = 0;
- }
}
static void persistent_drop(struct exception_store *store)