An ext3 filesystem on a read-only device, with an external journal
which is at a different device number then recorded in the superblock
will fail to honor the read-only setting of the device and trigger
a superblock update (write).
For example:
- ext3 on a software raid which is in read-only mode
- external journal on a read-write device which has changed device num
- attempt to mount with -o journal_dev=<new_number>
- hits BUG_ON(mddev->ro = 1) in md.c
Cc: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Maciej Åenczykowski <zenczykowski@xxxxxxxxx>
---
fs/ext3/super.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 5dbf4db..19dfbe9 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -2299,7 +2299,7 @@ static int ext3_load_journal(struct super_block *sb,
EXT3_SB(sb)->s_journal = journal;
ext3_clear_journal_err(sb, es);
- if (journal_devnum &&
+ if (!really_read_only && journal_devnum &&
journal_devnum != le32_to_cpu(es->s_journal_dev)) {
es->s_journal_dev = cpu_to_le32(journal_devnum);
--
1.7.2.3
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
