jbd: Fail to load a journal if it is too short
Jan Kara [Wed, 15 Jul 2009 18:36:08 +0000 (20:36 +0200)]
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 <rnsastry@linux.vnet.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/jbd/journal.c

index 737f724..94a64a1 100644 (file)
@@ -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;