[PATCH] dm snapshot: fix freeing pending exception
If a snapshot became invalid while there are outstanding pending_exceptions,
when pending_complete() processes each one it forgets to remove the
corresponding exception from its exception table before freeing it.
Fix this by moving the 'out:' label up one statement so that
remove_exception() is always called. Then __invalidate_exception() no longer
needs to call it and its 'pe' argument become superfluous.
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-snap.c b/drivers/md/dm-snap.c
index 638c8d9..5281e00 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -631,8 +631,7 @@
}
}
-static void __invalidate_snapshot(struct dm_snapshot *s,
- struct pending_exception *pe, int err)
+static void __invalidate_snapshot(struct dm_snapshot *s, int err)
{
if (!s->valid)
return;
@@ -642,9 +641,6 @@
else if (err == -ENOMEM)
DMERR("Invalidating snapshot: Unable to allocate exception.");
- if (pe)
- remove_exception(&pe->e);
-
if (s->store.drop_snapshot)
s->store.drop_snapshot(&s->store);
@@ -701,7 +697,7 @@
if (!success) {
/* Read/write error - snapshot is unusable */
down_write(&s->lock);
- __invalidate_snapshot(s, pe, -EIO);
+ __invalidate_snapshot(s, -EIO);
error = 1;
goto out;
}
@@ -709,7 +705,7 @@
e = alloc_exception();
if (!e) {
down_write(&s->lock);
- __invalidate_snapshot(s, pe, -ENOMEM);
+ __invalidate_snapshot(s, -ENOMEM);
error = 1;
goto out;
}
@@ -727,9 +723,9 @@
* in-flight exception from the list.
*/
insert_exception(&s->complete, e);
- remove_exception(&pe->e);
out:
+ remove_exception(&pe->e);
snapshot_bios = bio_list_get(&pe->snapshot_bios);
origin_bios = put_pending_exception(pe);
@@ -909,7 +905,7 @@
if (bio_rw(bio) == WRITE) {
pe = __find_pending_exception(s, bio);
if (!pe) {
- __invalidate_snapshot(s, pe, -ENOMEM);
+ __invalidate_snapshot(s, -ENOMEM);
r = -EIO;
goto out_unlock;
}
@@ -1035,7 +1031,7 @@
pe = __find_pending_exception(snap, bio);
if (!pe) {
- __invalidate_snapshot(snap, pe, -ENOMEM);
+ __invalidate_snapshot(snap, -ENOMEM);
goto next_snapshot;
}