From 88724bfa68be792c1487d759e87568c36ac1a1cc Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 24 Sep 2015 14:00:51 +1000 Subject: md: wait for pending superblock updates before switching to read-only If a superblock update is pending, wait for it to complete before letting md_set_readonly() switch to readonly. Otherwise we might lose important information about a device having failed. For external arrays, waiting for superblock updates can wait on user-space, so in that case, just return an error. Reported-and-tested-by: Shaohua Li Signed-off-by: NeilBrown --- drivers/md/md.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/md/md.c') diff --git a/drivers/md/md.c b/drivers/md/md.c index 4f5ecbe94ccb..b8247bc32cf6 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5409,9 +5409,13 @@ static int md_set_readonly(struct mddev *mddev, struct block_device *bdev) * which will now never happen */ wake_up_process(mddev->sync_thread->tsk); + if (mddev->external && test_bit(MD_CHANGE_PENDING, &mddev->flags)) + return -EBUSY; mddev_unlock(mddev); wait_event(resync_wait, !test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)); + wait_event(mddev->sb_wait, + !test_bit(MD_CHANGE_PENDING, &mddev->flags)); mddev_lock_nointr(mddev); mutex_lock(&mddev->open_mutex); -- cgit v1.2.2 From d4929add83ad4660b1824a9282ab5dd4d60140fa Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Fri, 18 Sep 2015 10:20:12 -0700 Subject: md: clear CHANGE_PENDING in readonly array If faulty disks of an array are more than allowed degraded number, the array enters error handling. It will be marked as read-only with MD_CHANGE_PENDING/RECOVERY_NEEDED set. But currently recovery doesn't clear CHANGE_PENDING bit for read-only array. If MD_CHANGE_PENDING is set for a raid5 array, all returned IO will be hold on a list till the bit is clear. But recovery nevery clears this bit, the IO is always in pending state and nevery finish. This has bad effects like upper layer can't get an IO error and the array can't be stopped. Fixes: c3cce6cda162 ("md/raid5: ensure device failure recorded before write request returns.") Signed-off-by: Shaohua Li Signed-off-by: NeilBrown --- drivers/md/md.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/md/md.c') diff --git a/drivers/md/md.c b/drivers/md/md.c index b8247bc32cf6..c702de18207a 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -8164,6 +8164,7 @@ void md_check_recovery(struct mddev *mddev) md_reap_sync_thread(mddev); clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery); clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + clear_bit(MD_CHANGE_PENDING, &mddev->flags); goto unlock; } -- cgit v1.2.2