bcache: Fix for when no journal entries are found
The journal replay code didn't handle this case, causing it to go into
an infinite loop...
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index c0017ca..f5203df 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -153,7 +153,8 @@
bitmap_zero(bitmap, SB_JOURNAL_BUCKETS);
pr_debug("%u journal buckets", ca->sb.njournal_buckets);
- /* Read journal buckets ordered by golden ratio hash to quickly
+ /*
+ * Read journal buckets ordered by golden ratio hash to quickly
* find a sequence of buckets with valid journal entries
*/
for (i = 0; i < ca->sb.njournal_buckets; i++) {
@@ -166,18 +167,20 @@
goto bsearch;
}
- /* If that fails, check all the buckets we haven't checked
+ /*
+ * If that fails, check all the buckets we haven't checked
* already
*/
pr_debug("falling back to linear search");
- for (l = 0; l < ca->sb.njournal_buckets; l++) {
- if (test_bit(l, bitmap))
- continue;
-
+ for (l = find_first_zero_bit(bitmap, ca->sb.njournal_buckets);
+ l < ca->sb.njournal_buckets;
+ l = find_next_zero_bit(bitmap, ca->sb.njournal_buckets, l + 1))
if (read_bucket(l))
goto bsearch;
- }
+
+ if (list_empty(list))
+ continue;
bsearch:
/* Binary search */
m = r = find_next_bit(bitmap, ca->sb.njournal_buckets, l + 1);
@@ -197,10 +200,12 @@
r = m;
}
- /* Read buckets in reverse order until we stop finding more
+ /*
+ * Read buckets in reverse order until we stop finding more
* journal entries
*/
- pr_debug("finishing up");
+ pr_debug("finishing up: m %u njournal_buckets %u",
+ m, ca->sb.njournal_buckets);
l = m;
while (1) {
@@ -228,9 +233,10 @@
}
}
- c->journal.seq = list_entry(list->prev,
- struct journal_replay,
- list)->j.seq;
+ if (!list_empty(list))
+ c->journal.seq = list_entry(list->prev,
+ struct journal_replay,
+ list)->j.seq;
return 0;
#undef read_bucket
