bcache: Journal replay fix
commit faa5673617656ee58369a3cfe4a312cfcdc59c81 upstream.
The journal replay code starts by finding something that looks like a
valid journal entry, then it does a binary search over the unchecked
region of the journal for the journal entries with the highest sequence
numbers.
Trouble is, the logic was wrong - journal_read_bucket() returns true if
it found journal entries we need, but if the range of journal entries
we're looking for loops around the end of the journal - in that case
journal_read_bucket() could return true when it hadn't found the highest
sequence number we'd seen yet, and in that case the binary search did
the wrong thing. Whoops.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 8c8dfdc..8a54d3b 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -182,9 +182,14 @@
pr_debug("starting binary search, l %u r %u", l, r);
while (l + 1 < r) {
- m = (l + r) >> 1;
+ seq = list_entry(list->prev, struct journal_replay,
+ list)->j.seq;
- if (read_bucket(m))
+ m = (l + r) >> 1;
+ read_bucket(m);
+
+ if (seq != list_entry(list->prev, struct journal_replay,
+ list)->j.seq)
l = m;
else
r = m;