From ed8b45a3679eb49069b094c0711b30833f27c734 Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Thu, 10 Dec 2015 14:37:53 +0000
Subject: [PATCH] dm btree: fix bufio buffer leaks in dm_btree_del() error path
If dm_btree_del()'s call to push_frame() fails, e.g. due to
btree_node_validator finding invalid metadata, the dm_btree_del() error
path must unlock all frames (which have active dm-bufio buffers) that
were pushed onto the del_stack.
Otherwise, dm_bufio_client_destroy() will BUG_ON() because dm-bufio
buffers have leaked, e.g.:
device-mapper: bufio: leaked buffer 3, hold count 1, list 0
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
---
drivers/md/persistent-data/dm-btree.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c
index 7e5b7f12958a..b1ced58eb5e1 100644
--- a/drivers/md/persistent-data/dm-btree.c
+++ b/drivers/md/persistent-data/dm-btree.c
@@ -257,6 +257,16 @@ static void pop_frame(struct del_stack *s)
dm_tm_unlock(s->tm, f->b);
}
+static void unlock_all_frames(struct del_stack *s)
+{
+ struct frame *f;
+
+ while (unprocessed_frames(s)) {
+ f = s->spine + s->top--;
+ dm_tm_unlock(s->tm, f->b);
+ }
+}
+
int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
{
int r;
@@ -313,9 +323,13 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root)
pop_frame(s);
}
}
-
out:
+ if (r) {
+ /* cleanup all frames of del_stack */
+ unlock_all_frames(s);
+ }
kfree(s);
+
return r;
}
EXPORT_SYMBOL_GPL(dm_btree_del);
--
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