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

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. Reported-by: Nageswara R Sastry <[email protected]> Signed-off-by: Jan Kara <[email protected]>
RyanHsu · Jul 15, 2009 · 7447a66 · 7447a66
1 parent e9e961c
commit 7447a66
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
@@ -848,6 +848,12 @@ static int journal_reset(journal_t *journal)
 
 	first = be32_to_cpu(sb->s_first);
 	last = be32_to_cpu(sb->s_maxlen);
+	if (first + JFS_MIN_JOURNAL_BLOCKS > last + 1) {
+		printk(KERN_ERR "JBD: Journal too short (blocks %lu-%lu).\n",
+		       first, last);
+		journal_fail_superblock(journal);
+		return -EINVAL;
+	}
 
 	journal->j_first = first;
 	journal->j_last = last;