From bb4a65df3097524be403d455176710aee14d41f7 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 12 Dec 2013 10:13:33 +1100 Subject: md: fix problem when adding device to read-only array with bitmap. commit 8313b8e57f55b15e5b7f7fc5d1630bbf686a9a97 upstream. If an array is started degraded, and then the missing device is found it can be re-added and a minimal bitmap-based recovery will bring it fully up-to-date. If the array is read-only a recovery would not be allowed. But also if the array is read-only and the missing device was present very recently, then there could be no need for any recovery at all, so we simply include the device in the read-only array without any recovery. However... if the missing device was removed a little longer ago it could be missing some updates, but if a bitmap is present it will be conditionally accepted pending a bitmap-based update. We don't currently detect this case properly and will include that old device into the read-only array with no recovery even though it really needs a recovery. This patch keeps track of whether a bitmap-based-recovery is really needed or not in the new Bitmap_sync rdev flag. If that is set, then the device will not be added to a read-only array. Cc: Andrei Warkentin Fixes: d70ed2e4fafdbef0800e73942482bb075c21578b Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- drivers/md/md.c | 18 +++++++++++++++--- drivers/md/md.h | 3 +++ 2 files changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 2290b95009d..a2dda416c9c 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -1118,6 +1118,7 @@ static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev) rdev->raid_disk = -1; clear_bit(Faulty, &rdev->flags); clear_bit(In_sync, &rdev->flags); + clear_bit(Bitmap_sync, &rdev->flags); clear_bit(WriteMostly, &rdev->flags); if (mddev->raid_disks == 0) { @@ -1196,6 +1197,8 @@ static int super_90_validate(struct mddev *mddev, struct md_rdev *rdev) */ if (ev1 < mddev->bitmap->events_cleared) return 0; + if (ev1 < mddev->events) + set_bit(Bitmap_sync, &rdev->flags); } else { if (ev1 < mddev->events) /* just a hot-add of a new device, leave raid_disk at -1 */ @@ -1604,6 +1607,7 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev) rdev->raid_disk = -1; clear_bit(Faulty, &rdev->flags); clear_bit(In_sync, &rdev->flags); + clear_bit(Bitmap_sync, &rdev->flags); clear_bit(WriteMostly, &rdev->flags); if (mddev->raid_disks == 0) { @@ -1686,6 +1690,8 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev) */ if (ev1 < mddev->bitmap->events_cleared) return 0; + if (ev1 < mddev->events) + set_bit(Bitmap_sync, &rdev->flags); } else { if (ev1 < mddev->events) /* just a hot-add of a new device, leave raid_disk at -1 */ @@ -2829,6 +2835,7 @@ slot_store(struct md_rdev *rdev, const char *buf, size_t len) else rdev->saved_raid_disk = -1; clear_bit(In_sync, &rdev->flags); + clear_bit(Bitmap_sync, &rdev->flags); err = rdev->mddev->pers-> hot_add_disk(rdev->mddev, rdev); if (err) { @@ -5761,6 +5768,7 @@ static int add_new_disk(struct mddev * mddev, mdu_disk_info_t *info) info->raid_disk < mddev->raid_disks) { rdev->raid_disk = info->raid_disk; set_bit(In_sync, &rdev->flags); + clear_bit(Bitmap_sync, &rdev->flags); } else rdev->raid_disk = -1; } else @@ -7694,7 +7702,8 @@ static int remove_and_add_spares(struct mddev *mddev, if (test_bit(Faulty, &rdev->flags)) continue; if (mddev->ro && - rdev->saved_raid_disk < 0) + ! (rdev->saved_raid_disk >= 0 && + !test_bit(Bitmap_sync, &rdev->flags))) continue; rdev->recovery_offset = 0; @@ -7775,9 +7784,12 @@ void md_check_recovery(struct mddev *mddev) * As we only add devices that are already in-sync, * we can activate the spares immediately. */ - clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery); remove_and_add_spares(mddev, NULL); - mddev->pers->spare_active(mddev); + /* There is no thread, but we need to call + * ->spare_active and clear saved_raid_disk + */ + md_reap_sync_thread(mddev); + clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery); goto unlock; } diff --git a/drivers/md/md.h b/drivers/md/md.h index 653f992b687..ebe748e5741 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -129,6 +129,9 @@ struct md_rdev { enum flag_bits { Faulty, /* device is known to have a fault */ In_sync, /* device is in_sync with rest of array */ + Bitmap_sync, /* ..actually, not quite In_sync. Need a + * bitmap-based recovery to get fully in sync + */ Unmerged, /* device is being added to array and should * be considerred for bvec_merge_fn but not * yet for actual IO -- cgit v1.2.3