If a bitmap recovery is interrupted and later restarted, then sectors below the recovery offset, written between interruption and resumption, will not be copied. This results in corruption. See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=777511 for a script that can be used to repro this. Seems like ignoring the recovery_offset if a bitmap exists is the way to go. Signed-off-by: Nate Dailey <nate.dailey@xxxxxxxxxxx> --- drivers/md/md.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 0c2a4e8..79c6285 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -7738,16 +7738,18 @@ void md_do_sync(struct md_thread *thread) else { /* recovery follows the physical size of devices */ max_sectors = mddev->dev_sectors; - j = MaxSector; - rcu_read_lock(); - rdev_for_each_rcu(rdev, mddev) - if (rdev->raid_disk >= 0 && - !test_bit(Faulty, &rdev->flags) && - !test_bit(In_sync, &rdev->flags) && - rdev->recovery_offset < j) - j = rdev->recovery_offset; - rcu_read_unlock(); - + /* we don't use the offset if there's a bitmap */ + if (!mddev->bitmap) { + j = MaxSector; + rcu_read_lock(); + rdev_for_each_rcu(rdev, mddev) + if (rdev->raid_disk >= 0 && + !test_bit(Faulty, &rdev->flags) && + !test_bit(In_sync, &rdev->flags) && + rdev->recovery_offset < j) + j = rdev->recovery_offset; + rcu_read_unlock(); + } /* If there is a bitmap, we need to make sure all * writes that started before we added a spare * complete before we start doing a recovery. @@ -7756,7 +7758,7 @@ void md_do_sync(struct md_thread *thread) * recovery has checked that bit and skipped that * region. */ - if (mddev->bitmap) { + else { mddev->pers->quiesce(mddev, 1); mddev->pers->quiesce(mddev, 0); } -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
