From: Jan Kara <jack@suse.cz>
Date: Fri, 17 Jul 2009 14:40:01 +0000 (-0400)
Subject: jbd2: Fail to load a journal if it is too short
X-Git-Tag: v2.6.31.8~88
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=34dd3ffe4b57ce9e38ad3258dae5051c7c6a204b;p=karo-tx-linux.git

jbd2: Fail to load a journal if it is too short

(cherry picked from commit f6f50e28f0cb8d7bcdfaacc83129f005dede11b1)

Due to on disk corruption, it can happen that journal is too short. Fail
to load it in such case so that we don't oops somewhere later.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index e378cb383979..a8a358bc0f21 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1187,6 +1187,12 @@ static int journal_reset(journal_t *journal)
 
 	first = be32_to_cpu(sb->s_first);
 	last = be32_to_cpu(sb->s_maxlen);
+	if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) {
+		printk(KERN_ERR "JBD: Journal too short (blocks %llu-%llu).\n",
+		       first, last);
+		journal_fail_superblock(journal);
+		return -EINVAL;
+	}
 
 	journal->j_first = first;
 	journal->j_last = last;