Commit faa56736 authored Jul 11, 2013 by Kent Overstreet

bcache: Journal replay fix



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>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10

parent 5caa52af

drivers/md/bcache/journal.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -184,9 +184,14 @@ bsearch:
		pr_debug("starting binary search, l %u r %u", l, r);

		while (l + 1 < r) {
		seq = list_entry(list->prev, struct journal_replay,
		list)->j.seq;

		m = (l + r) >> 1;
		read_bucket(m);

		if (read_bucket(m))
		if (seq != list_entry(list->prev, struct journal_replay,
		list)->j.seq)
		l = m;
		else
		r = m;