]> nv-tegra.nvidia Code Review - linux-2.6.git/blobdiff - drivers/md/raid1.c
md: support blocking writes to an array on device failure
[linux-2.6.git] / drivers / md / raid1.c
index 656fae912fe3550e06a17f14a851f05a7dd63fd2..6778b7cb39bd5dd94eb719683267a6bef926e3cf 100644 (file)
@@ -9,7 +9,7 @@
  *
  * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000
  *
- * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
+ * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk>
  * Various fixes by Neil Brown <neilb@cse.unsw.edu.au>
  *
  * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support
@@ -238,7 +238,7 @@ static void raid_end_bio_io(r1bio_t *r1_bio)
                        (unsigned long long) bio->bi_sector +
                                (bio->bi_size >> 9) - 1);
 
-               bio_endio(bio, bio->bi_size,
+               bio_endio(bio,
                        test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO);
        }
        free_r1bio(r1_bio);
@@ -255,37 +255,38 @@ static inline void update_head_pos(int disk, r1bio_t *r1_bio)
                r1_bio->sector + (r1_bio->sectors);
 }
 
-static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int error)
+static void raid1_end_read_request(struct bio *bio, int error)
 {
        int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
        r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
        int mirror;
        conf_t *conf = mddev_to_conf(r1_bio->mddev);
 
-       if (bio->bi_size)
-               return 1;
-       
        mirror = r1_bio->read_disk;
        /*
         * this branch is our 'one mirror IO has finished' event handler:
         */
        update_head_pos(mirror, r1_bio);
 
-       if (uptodate || (conf->raid_disks - conf->mddev->degraded) <= 1) {
-               /*
-                * Set R1BIO_Uptodate in our master bio, so that
-                * we will return a good error code for to the higher
-                * levels even if IO on some other mirrored buffer fails.
-                *
-                * The 'master' represents the composite IO operation to
-                * user-side. So if something waits for IO, then it will
-                * wait for the 'master' bio.
+       if (uptodate)
+               set_bit(R1BIO_Uptodate, &r1_bio->state);
+       else {
+               /* If all other devices have failed, we want to return
+                * the error upwards rather than fail the last device.
+                * Here we redefine "uptodate" to mean "Don't want to retry"
                 */
-               if (uptodate)
-                       set_bit(R1BIO_Uptodate, &r1_bio->state);
+               unsigned long flags;
+               spin_lock_irqsave(&conf->device_lock, flags);
+               if (r1_bio->mddev->degraded == conf->raid_disks ||
+                   (r1_bio->mddev->degraded == conf->raid_disks-1 &&
+                    !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)))
+                       uptodate = 1;
+               spin_unlock_irqrestore(&conf->device_lock, flags);
+       }
 
+       if (uptodate)
                raid_end_bio_io(r1_bio);
-       else {
+       else {
                /*
                 * oops, read error:
                 */
@@ -297,10 +298,9 @@ static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int
        }
 
        rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev);
-       return 0;
 }
 
-static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int error)
+static void raid1_end_write_request(struct bio *bio, int error)
 {
        int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
        r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
@@ -308,8 +308,6 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
        conf_t *conf = mddev_to_conf(r1_bio->mddev);
        struct bio *to_put = NULL;
 
-       if (bio->bi_size)
-               return 1;
 
        for (mirror = 0; mirror < conf->raid_disks; mirror++)
                if (r1_bio->bios[mirror] == bio)
@@ -362,7 +360,7 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
                                               (unsigned long long) mbio->bi_sector,
                                               (unsigned long long) mbio->bi_sector +
                                               (mbio->bi_size >> 9) - 1);
-                                       bio_endio(mbio, mbio->bi_size, 0);
+                                       bio_endio(mbio, 0);
                                }
                        }
                }
@@ -396,8 +394,6 @@ static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int
 
        if (to_put)
                bio_put(to_put);
-
-       return 0;
 }
 
 
@@ -548,13 +544,12 @@ static void unplug_slaves(mddev_t *mddev)
        for (i=0; i<mddev->raid_disks; i++) {
                mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
                if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
-                       request_queue_t *r_queue = bdev_get_queue(rdev->bdev);
+                       struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
 
                        atomic_inc(&rdev->nr_pending);
                        rcu_read_unlock();
 
-                       if (r_queue->unplug_fn)
-                               r_queue->unplug_fn(r_queue);
+                       blk_unplug(r_queue);
 
                        rdev_dec_pending(rdev, mddev);
                        rcu_read_lock();
@@ -563,7 +558,7 @@ static void unplug_slaves(mddev_t *mddev)
        rcu_read_unlock();
 }
 
-static void raid1_unplug(request_queue_t *q)
+static void raid1_unplug(struct request_queue *q)
 {
        mddev_t *mddev = q->queuedata;
 
@@ -571,36 +566,6 @@ static void raid1_unplug(request_queue_t *q)
        md_wakeup_thread(mddev->thread);
 }
 
-static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk,
-                            sector_t *error_sector)
-{
-       mddev_t *mddev = q->queuedata;
-       conf_t *conf = mddev_to_conf(mddev);
-       int i, ret = 0;
-
-       rcu_read_lock();
-       for (i=0; i<mddev->raid_disks && ret == 0; i++) {
-               mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
-               if (rdev && !test_bit(Faulty, &rdev->flags)) {
-                       struct block_device *bdev = rdev->bdev;
-                       request_queue_t *r_queue = bdev_get_queue(bdev);
-
-                       if (!r_queue->issue_flush_fn)
-                               ret = -EOPNOTSUPP;
-                       else {
-                               atomic_inc(&rdev->nr_pending);
-                               rcu_read_unlock();
-                               ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk,
-                                                             error_sector);
-                               rdev_dec_pending(rdev, mddev);
-                               rcu_read_lock();
-                       }
-               }
-       }
-       rcu_read_unlock();
-       return ret;
-}
-
 static int raid1_congested(void *data, int bits)
 {
        mddev_t *mddev = data;
@@ -611,7 +576,7 @@ static int raid1_congested(void *data, int bits)
        for (i = 0; i < mddev->raid_disks; i++) {
                mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
                if (rdev && !test_bit(Faulty, &rdev->flags)) {
-                       request_queue_t *q = bdev_get_queue(rdev->bdev);
+                       struct request_queue *q = bdev_get_queue(rdev->bdev);
 
                        /* Note the '|| 1' - when read_balance prefers
                         * non-congested targets, it can be removed
@@ -627,6 +592,37 @@ static int raid1_congested(void *data, int bits)
 }
 
 
+static int flush_pending_writes(conf_t *conf)
+{
+       /* Any writes that have been queued but are awaiting
+        * bitmap updates get flushed here.
+        * We return 1 if any requests were actually submitted.
+        */
+       int rv = 0;
+
+       spin_lock_irq(&conf->device_lock);
+
+       if (conf->pending_bio_list.head) {
+               struct bio *bio;
+               bio = bio_list_get(&conf->pending_bio_list);
+               blk_remove_plug(conf->mddev->queue);
+               spin_unlock_irq(&conf->device_lock);
+               /* flush any pending bitmap writes to
+                * disk before proceeding w/ I/O */
+               bitmap_unplug(conf->mddev->bitmap);
+
+               while (bio) { /* submit pending writes */
+                       struct bio *next = bio->bi_next;
+                       bio->bi_next = NULL;
+                       generic_make_request(bio);
+                       bio = next;
+               }
+               rv = 1;
+       } else
+               spin_unlock_irq(&conf->device_lock);
+       return rv;
+}
+
 /* Barriers....
  * Sometimes we need to suspend IO while we do something else,
  * either some resync/recovery, or reconfigure the array.
@@ -708,15 +704,23 @@ static void freeze_array(conf_t *conf)
        /* stop syncio and normal IO and wait for everything to
         * go quite.
         * We increment barrier and nr_waiting, and then
-        * wait until barrier+nr_pending match nr_queued+2
+        * wait until nr_pending match nr_queued+1
+        * This is called in the context of one normal IO request
+        * that has failed. Thus any sync request that might be pending
+        * will be blocked by nr_pending, and we need to wait for
+        * pending IO requests to complete or be queued for re-try.
+        * Thus the number queued (nr_queued) plus this request (1)
+        * must match the number of pending IOs (nr_pending) before
+        * we continue.
         */
        spin_lock_irq(&conf->resync_lock);
        conf->barrier++;
        conf->nr_waiting++;
        wait_event_lock_irq(conf->wait_barrier,
-                           conf->barrier+conf->nr_pending == conf->nr_queued+2,
+                           conf->nr_pending == conf->nr_queued+1,
                            conf->resync_lock,
-                           raid1_unplug(conf->mddev->queue));
+                           ({ flush_pending_writes(conf);
+                              raid1_unplug(conf->mddev->queue); }));
        spin_unlock_irq(&conf->resync_lock);
 }
 static void unfreeze_array(conf_t *conf)
@@ -761,7 +765,7 @@ do_sync_io:
        return NULL;
 }
 
-static int make_request(request_queue_t *q, struct bio * bio)
+static int make_request(struct request_queue *q, struct bio * bio)
 {
        mddev_t *mddev = q->queuedata;
        conf_t *conf = mddev_to_conf(mddev);
@@ -769,13 +773,14 @@ static int make_request(request_queue_t *q, struct bio * bio)
        r1bio_t *r1_bio;
        struct bio *read_bio;
        int i, targets = 0, disks;
-       mdk_rdev_t *rdev;
        struct bitmap *bitmap = mddev->bitmap;
        unsigned long flags;
        struct bio_list bl;
        struct page **behind_pages = NULL;
        const int rw = bio_data_dir(bio);
+       const int do_sync = bio_sync(bio);
        int do_barriers;
+       mdk_rdev_t *blocked_rdev;
 
        /*
         * Register the new request and wait if the reconstruction
@@ -791,7 +796,7 @@ static int make_request(request_queue_t *q, struct bio * bio)
        if (unlikely(!mddev->barriers_work && bio_barrier(bio))) {
                if (rw == WRITE)
                        md_write_end(mddev);
-               bio_endio(bio, bio->bi_size, -EOPNOTSUPP);
+               bio_endio(bio, -EOPNOTSUPP);
                return 0;
        }
 
@@ -835,7 +840,7 @@ static int make_request(request_queue_t *q, struct bio * bio)
                read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset;
                read_bio->bi_bdev = mirror->rdev->bdev;
                read_bio->bi_end_io = raid1_end_read_request;
-               read_bio->bi_rw = READ;
+               read_bio->bi_rw = READ | do_sync;
                read_bio->bi_private = r1_bio;
 
                generic_make_request(read_bio);
@@ -857,10 +862,17 @@ static int make_request(request_queue_t *q, struct bio * bio)
        first = 0;
        }
 #endif
+ retry_write:
+       blocked_rdev = NULL;
        rcu_read_lock();
        for (i = 0;  i < disks; i++) {
-               if ((rdev=rcu_dereference(conf->mirrors[i].rdev)) != NULL &&
-                   !test_bit(Faulty, &rdev->flags)) {
+               mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
+               if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
+                       atomic_inc(&rdev->nr_pending);
+                       blocked_rdev = rdev;
+                       break;
+               }
+               if (rdev && !test_bit(Faulty, &rdev->flags)) {
                        atomic_inc(&rdev->nr_pending);
                        if (test_bit(Faulty, &rdev->flags)) {
                                rdev_dec_pending(rdev, mddev);
@@ -873,6 +885,20 @@ static int make_request(request_queue_t *q, struct bio * bio)
        }
        rcu_read_unlock();
 
+       if (unlikely(blocked_rdev)) {
+               /* Wait for this device to become unblocked */
+               int j;
+
+               for (j = 0; j < i; j++)
+                       if (r1_bio->bios[j])
+                               rdev_dec_pending(conf->mirrors[j].rdev, mddev);
+
+               allow_barrier(conf);
+               md_wait_for_blocked_rdev(blocked_rdev, mddev);
+               wait_barrier(conf);
+               goto retry_write;
+       }
+
        BUG_ON(targets == 0); /* we never fail the last device */
 
        if (targets < conf->raid_disks) {
@@ -906,7 +932,7 @@ static int make_request(request_queue_t *q, struct bio * bio)
                mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
                mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
                mbio->bi_end_io = raid1_end_write_request;
-               mbio->bi_rw = WRITE | do_barriers;
+               mbio->bi_rw = WRITE | do_barriers | do_sync;
                mbio->bi_private = r1_bio;
 
                if (behind_pages) {
@@ -941,6 +967,11 @@ static int make_request(request_queue_t *q, struct bio * bio)
        blk_plug_device(mddev->queue);
        spin_unlock_irqrestore(&conf->device_lock, flags);
 
+       /* In case raid1d snuck into freeze_array */
+       wake_up(&conf->wait_barrier);
+
+       if (do_sync)
+               md_wakeup_thread(mddev->thread);
 #if 0
        while ((bio = bio_list_pop(&bl)) != NULL)
                generic_make_request(bio);
@@ -989,16 +1020,17 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
                unsigned long flags;
                spin_lock_irqsave(&conf->device_lock, flags);
                mddev->degraded++;
+               set_bit(Faulty, &rdev->flags);
                spin_unlock_irqrestore(&conf->device_lock, flags);
                /*
                 * if recovery is running, make sure it aborts.
                 */
                set_bit(MD_RECOVERY_ERR, &mddev->recovery);
-       }
-       set_bit(Faulty, &rdev->flags);
+       } else
+               set_bit(Faulty, &rdev->flags);
        set_bit(MD_CHANGE_DEVS, &mddev->flags);
-       printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n"
-               "       Operation continuing on %d devices\n",
+       printk(KERN_ALERT "raid1: Disk failure on %s, disabling device.\n"
+               "raid1: Operation continuing on %d devices.\n",
                bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
 }
 
@@ -1129,14 +1161,11 @@ abort:
 }
 
 
-static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
+static void end_sync_read(struct bio *bio, int error)
 {
        r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
        int i;
 
-       if (bio->bi_size)
-               return 1;
-
        for (i=r1_bio->mddev->raid_disks; i--; )
                if (r1_bio->bios[i] == bio)
                        break;
@@ -1152,10 +1181,9 @@ static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
 
        if (atomic_dec_and_test(&r1_bio->remaining))
                reschedule_retry(r1_bio);
-       return 0;
 }
 
-static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
+static void end_sync_write(struct bio *bio, int error)
 {
        int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
        r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private);
@@ -1164,9 +1192,6 @@ static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
        int i;
        int mirror=0;
 
-       if (bio->bi_size)
-               return 1;
-
        for (i = 0; i < conf->raid_disks; i++)
                if (r1_bio->bios[i] == bio) {
                        mirror = i;
@@ -1192,7 +1217,6 @@ static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
                md_done_sync(mddev, r1_bio->sectors, uptodate);
                put_buf(r1_bio);
        }
-       return 0;
 }
 
 static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
@@ -1232,20 +1256,28 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
                        }
                r1_bio->read_disk = primary;
                for (i=0; i<mddev->raid_disks; i++)
-                       if (r1_bio->bios[i]->bi_end_io == end_sync_read &&
-                           test_bit(BIO_UPTODATE, &r1_bio->bios[i]->bi_flags)) {
+                       if (r1_bio->bios[i]->bi_end_io == end_sync_read) {
                                int j;
                                int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
                                struct bio *pbio = r1_bio->bios[primary];
                                struct bio *sbio = r1_bio->bios[i];
-                               for (j = vcnt; j-- ; )
-                                       if (memcmp(page_address(pbio->bi_io_vec[j].bv_page),
-                                                  page_address(sbio->bi_io_vec[j].bv_page),
-                                                  PAGE_SIZE))
-                                               break;
+
+                               if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) {
+                                       for (j = vcnt; j-- ; ) {
+                                               struct page *p, *s;
+                                               p = pbio->bi_io_vec[j].bv_page;
+                                               s = sbio->bi_io_vec[j].bv_page;
+                                               if (memcmp(page_address(p),
+                                                          page_address(s),
+                                                          PAGE_SIZE))
+                                                       break;
+                                       }
+                               } else
+                                       j = 0;
                                if (j >= 0)
                                        mddev->resync_mismatches += r1_bio->sectors;
-                               if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
+                               if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
+                                             && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
                                        sbio->bi_end_io = NULL;
                                        rdev_dec_pending(conf->mirrors[i].rdev, mddev);
                                } else {
@@ -1263,6 +1295,11 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
                                        sbio->bi_sector = r1_bio->sector +
                                                conf->mirrors[i].rdev->data_offset;
                                        sbio->bi_bdev = conf->mirrors[i].rdev->bdev;
+                                       for (j = 0; j < vcnt ; j++)
+                                               memcpy(page_address(sbio->bi_io_vec[j].bv_page),
+                                                      page_address(pbio->bi_io_vec[j].bv_page),
+                                                      PAGE_SIZE);
+
                                }
                        }
        }
@@ -1499,29 +1536,14 @@ static void raid1d(mddev_t *mddev)
        
        for (;;) {
                char b[BDEVNAME_SIZE];
-               spin_lock_irqsave(&conf->device_lock, flags);
 
-               if (conf->pending_bio_list.head) {
-                       bio = bio_list_get(&conf->pending_bio_list);
-                       blk_remove_plug(mddev->queue);
-                       spin_unlock_irqrestore(&conf->device_lock, flags);
-                       /* flush any pending bitmap writes to disk before proceeding w/ I/O */
-                       if (bitmap_unplug(mddev->bitmap) != 0)
-                               printk("%s: bitmap file write failed!\n", mdname(mddev));
-
-                       while (bio) { /* submit pending writes */
-                               struct bio *next = bio->bi_next;
-                               bio->bi_next = NULL;
-                               generic_make_request(bio);
-                               bio = next;
-                       }
-                       unplug = 1;
-
-                       continue;
-               }
+               unplug += flush_pending_writes(conf);
 
-               if (list_empty(head))
+               spin_lock_irqsave(&conf->device_lock, flags);
+               if (list_empty(head)) {
+                       spin_unlock_irqrestore(&conf->device_lock, flags);
                        break;
+               }
                r1_bio = list_entry(head->prev, r1bio_t, retry_list);
                list_del(head->prev);
                conf->nr_queued--;
@@ -1541,6 +1563,7 @@ static void raid1d(mddev_t *mddev)
                         * We already have a nr_pending reference on these rdevs.
                         */
                        int i;
+                       const int do_sync = bio_sync(r1_bio->master_bio);
                        clear_bit(R1BIO_BarrierRetry, &r1_bio->state);
                        clear_bit(R1BIO_Barrier, &r1_bio->state);
                        for (i=0; i < conf->raid_disks; i++)
@@ -1561,7 +1584,7 @@ static void raid1d(mddev_t *mddev)
                                                conf->mirrors[i].rdev->data_offset;
                                        bio->bi_bdev = conf->mirrors[i].rdev->bdev;
                                        bio->bi_end_io = raid1_end_write_request;
-                                       bio->bi_rw = WRITE;
+                                       bio->bi_rw = WRITE | do_sync;
                                        bio->bi_private = r1_bio;
                                        r1_bio->bios[i] = bio;
                                        generic_make_request(bio);
@@ -1593,6 +1616,7 @@ static void raid1d(mddev_t *mddev)
                                       (unsigned long long)r1_bio->sector);
                                raid_end_bio_io(r1_bio);
                        } else {
+                               const int do_sync = bio_sync(r1_bio->master_bio);
                                r1_bio->bios[r1_bio->read_disk] =
                                        mddev->ro ? IO_BLOCKED : NULL;
                                r1_bio->read_disk = disk;
@@ -1608,14 +1632,13 @@ static void raid1d(mddev_t *mddev)
                                bio->bi_sector = r1_bio->sector + rdev->data_offset;
                                bio->bi_bdev = rdev->bdev;
                                bio->bi_end_io = raid1_end_read_request;
-                               bio->bi_rw = READ;
+                               bio->bi_rw = READ | do_sync;
                                bio->bi_private = r1_bio;
                                unplug = 1;
                                generic_make_request(bio);
                        }
                }
        }
-       spin_unlock_irqrestore(&conf->device_lock, flags);
        if (unplug)
                unplug_slaves(mddev);
 }
@@ -1709,6 +1732,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
        if (!go_faster && conf->nr_waiting)
                msleep_interruptible(1000);
 
+       bitmap_cond_end_sync(mddev->bitmap, sector_nr);
        raise_barrier(conf);
 
        conf->next_resync = sector_nr;
@@ -1736,7 +1760,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                /* take from bio_init */
                bio->bi_next = NULL;
                bio->bi_flags |= 1 << BIO_UPTODATE;
-               bio->bi_rw = 0;
+               bio->bi_rw = READ;
                bio->bi_vcnt = 0;
                bio->bi_idx = 0;
                bio->bi_phys_segments = 0;
@@ -1791,6 +1815,8 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
                return rv;
        }
 
+       if (max_sector > mddev->resync_max)
+               max_sector = mddev->resync_max; /* Don't do IO beyond here */
        nr_sectors = 0;
        sync_blocks = 0;
        do {
@@ -1909,7 +1935,7 @@ static int run(mddev_t *mddev)
        if (!conf->r1bio_pool)
                goto out_no_mem;
 
-       ITERATE_RDEV(mddev, rdev, tmp) {
+       rdev_for_each(rdev, tmp, mddev) {
                disk_idx = rdev->raid_disk;
                if (disk_idx >= mddev->raid_disks
                    || disk_idx < 0)
@@ -1951,6 +1977,8 @@ static int run(mddev_t *mddev)
                    !test_bit(In_sync, &disk->rdev->flags)) {
                        disk->head_position = 0;
                        mddev->degraded++;
+                       if (disk->rdev)
+                               conf->fullsync = 1;
                }
        }
        if (mddev->degraded == conf->raid_disks) {
@@ -1990,7 +2018,6 @@ static int run(mddev_t *mddev)
        mddev->array_size = mddev->size;
 
        mddev->queue->unplug_fn = raid1_unplug;
-       mddev->queue->issue_flush_fn = raid1_issue_flush;
        mddev->queue->backing_dev_info.congested_fn = raid1_congested;
        mddev->queue->backing_dev_info.congested_data = mddev;
 
@@ -2093,6 +2120,8 @@ static int raid1_reshape(mddev_t *mddev)
                return -EINVAL;
        }
 
+       md_allow_write(mddev);
+
        raid_disks = mddev->raid_disks + mddev->delta_disks;
 
        if (raid_disks < conf->raid_disks) {
@@ -2129,11 +2158,25 @@ static int raid1_reshape(mddev_t *mddev)
        oldpool = conf->r1bio_pool;
        conf->r1bio_pool = newpool;
 
-       for (d=d2=0; d < conf->raid_disks; d++)
-               if (conf->mirrors[d].rdev) {
-                       conf->mirrors[d].rdev->raid_disk = d2;
-                       newmirrors[d2++].rdev = conf->mirrors[d].rdev;
+       for (d = d2 = 0; d < conf->raid_disks; d++) {
+               mdk_rdev_t *rdev = conf->mirrors[d].rdev;
+               if (rdev && rdev->raid_disk != d2) {
+                       char nm[20];
+                       sprintf(nm, "rd%d", rdev->raid_disk);
+                       sysfs_remove_link(&mddev->kobj, nm);
+                       rdev->raid_disk = d2;
+                       sprintf(nm, "rd%d", rdev->raid_disk);
+                       sysfs_remove_link(&mddev->kobj, nm);
+                       if (sysfs_create_link(&mddev->kobj,
+                                             &rdev->kobj, nm))
+                               printk(KERN_WARNING
+                                      "md/raid1: cannot register "
+                                      "%s for %s\n",
+                                      nm, mdname(mddev));
                }
+               if (rdev)
+                       newmirrors[d2++].rdev = rdev;
+       }
        kfree(conf->mirrors);
        conf->mirrors = newmirrors;
        kfree(conf->poolinfo);