tree 8f0d6e4786c8c0d58c39843a57119aef0015c55d
parent 3c0eee3fe6a3a1c745379547c7e7c904aa64f6d5
author Maciej Żenczykowski <zenczykowski@gmail.com> 1285504708 +0000
committer Jan Kara <jack@suse.cz> 1294311134 +0100

ext3: don't update sb journal_devnum when RO dev

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@mit.edu>
Signed-off-by: Maciej Żenczykowski <zenczykowski@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>