dm log writes: make sure super sector log updates are written in order

Currently, although we submit super bios in order (and super.nr_entries
is incremented by each logged entry), submit_bio() is async so each
super sector may not be written to log device in order and then the
final nr_entries may be smaller than it should be.

This problem can be reproduced by the xfstests generic/455 with ext4:

  QA output created by 455
 -Silence is golden
 +mark 'end' does not exist

Fix this by serializing submission of super sectors to make sure each
is written to the log disk in order.

Fixes: 0e9cebe724597 ("dm: add log writes target")
Cc: [email protected]
Signed-off-by: zhangyi (F) <[email protected]>
Suggested-by: Josef Bacik <[email protected]>
Reviewed-by: Josef Bacik <[email protected]>
Signed-off-by: Mike Snitzer <[email protected]>

0 files changed, 0 insertions, 0 deletions