Merge tag 'md/3.13-fixes' of git://neil.brown.name/md

Pull late md fixes from Neil Brown:
 "Half a dozen md bug fixes.

  All of these fix real bugs the people have hit, and are tagged for
  -stable.  Sorry they are late ....  Christmas holidays and all that.
  Hopefully they can still squeak into 3.13"

* tag 'md/3.13-fixes' of git://neil.brown.name/md:
  md: fix problem when adding device to read-only array with bitmap.
  md/raid10: fix bug when raid10 recovery fails to recover a block.
  md/raid5: fix a recently broken BUG_ON().
  md/raid1: fix request counting bug in new 'barrier' code.
  md/raid10: fix two bugs in handling of known-bad-blocks.
  md/raid5: Fix possible confusion when multiple write errors occur.

5 files changed, 29 insertions, 14 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 21f4d7ff0da2..369d919bdafe 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1077,6 +1077,7 @@ 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) {
@@ -1155,6 +1156,8 @@ 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 */
@@ -1563,6 +1566,7 @@ 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) {
@@ -1645,6 +1649,8 @@ 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 */
@@ -2788,6 +2794,7 @@ 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) {
@@ -5760,6 +5767,7 @@ 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
@@ -7706,7 +7714,8 @@ 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;
@@ -7787,9 +7796,12 @@ 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 2f5cc8a7ef3e..0095ec84ffc7 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
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 1e5a540995e9..a49cfcc7a343 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -924,9 +924,8 @@ static sector_t wait_barrier(struct r1conf *conf, struct bio *bio)
                                 conf->next_window_requests++;
                         else
                                 conf->current_window_requests++;
-                }
-                if (bio->bi_sector >= conf->start_next_window)
                         sector = conf->start_next_window;
+                }
         }
 
         conf->nr_pending++;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index c504e8389e69..06eeb99ea6fc 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1319,7 +1319,7 @@ read_again:
                         /* Could not read all from this device, so we will
                          * need another r10_bio.
                          */
-                        sectors_handled = (r10_bio->sectors + max_sectors
+                        sectors_handled = (r10_bio->sector + max_sectors
                                            - bio->bi_sector);
                         r10_bio->sectors = max_sectors;
                         spin_lock_irq(&conf->device_lock);
@@ -1327,7 +1327,7 @@ read_again:
                                 bio->bi_phys_segments = 2;
                         else
                                 bio->bi_phys_segments++;
-                        spin_unlock(&conf->device_lock);
+                        spin_unlock_irq(&conf->device_lock);
                         /* Cannot call generic_make_request directly
                          * as that will be queued in __generic_make_request
                          * and subsequent mempool_alloc might block
@@ -3218,10 +3218,6 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
                         if (j == conf->copies) {
                                 /* Cannot recover, so abort the recovery or
                                  * record a bad block */
-                                put_buf(r10_bio);
-                                if (rb2)
-                                        atomic_dec(&rb2->remaining);
-                                r10_bio = rb2;
                                 if (any_working) {
                                         /* problem is that there are bad blocks
                                          * on other device(s)
@@ -3253,6 +3249,10 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
                                         mirror->recovery_disabled
                                                 = mddev->recovery_disabled;
                                 }
+                                put_buf(r10_bio);
+                                if (rb2)
+                                        atomic_dec(&rb2->remaining);
+                                r10_bio = rb2;
                                 break;
                         }
                 }
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index cc055da02e2a..cbb15716a5db 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -687,7 +687,8 @@ get_active_stripe(struct r5conf *conf, sector_t sector,
                         } else {
                                 if (!test_bit(STRIPE_HANDLE, &sh->state))
                                         atomic_inc(&conf->active_stripes);
-                                BUG_ON(list_empty(&sh->lru));
+                                BUG_ON(list_empty(&sh->lru) &&
+                                       !test_bit(STRIPE_EXPANDING, &sh->state));
                                 list_del_init(&sh->lru);
                                 if (sh->group) {
                                         sh->group->stripes_cnt--;
@@ -3608,7 +3609,7 @@ static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
                          */
                         set_bit(R5_Insync, &dev->flags);
 
-                if (rdev && test_bit(R5_WriteError, &dev->flags)) {
+                if (test_bit(R5_WriteError, &dev->flags)) {
                         /* This flag does not apply to '.replacement'
                          * only to .rdev, so make sure to check that*/
                         struct md_rdev *rdev2 = rcu_dereference(
@@ -3621,7 +3622,7 @@ static void analyse_stripe(struct stripe_head *sh, struct stripe_head_state *s)
                         } else
                                 clear_bit(R5_WriteError, &dev->flags);
                 }
-                if (rdev && test_bit(R5_MadeGood, &dev->flags)) {
+                if (test_bit(R5_MadeGood, &dev->flags)) {
                         /* This flag does not apply to '.replacement'
                          * only to .rdev, so make sure to check that*/
                         struct md_rdev *rdev2 = rcu_dereference(