Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linus
[pandora-kernel.git] / drivers / md / raid5.c
index 15348c3..9ea17d6 100644 (file)
@@ -53,6 +53,7 @@
 #include <linux/slab.h>
 #include "md.h"
 #include "raid5.h"
+#include "raid0.h"
 #include "bitmap.h"
 
 /*
@@ -1509,7 +1510,7 @@ static void raid5_end_read_request(struct bio * bi, int error)
                set_bit(R5_UPTODATE, &sh->dev[i].flags);
                if (test_bit(R5_ReadError, &sh->dev[i].flags)) {
                        rdev = conf->disks[i].rdev;
-                       printk_rl(KERN_INFO "raid5:%s: read error corrected"
+                       printk_rl(KERN_INFO "md/raid:%s: read error corrected"
                                  " (%lu sectors at %llu on %s)\n",
                                  mdname(conf->mddev), STRIPE_SECTORS,
                                  (unsigned long long)(sh->sector
@@ -1529,7 +1530,7 @@ static void raid5_end_read_request(struct bio * bi, int error)
                atomic_inc(&rdev->read_errors);
                if (conf->mddev->degraded >= conf->max_degraded)
                        printk_rl(KERN_WARNING
-                                 "raid5:%s: read error not correctable "
+                                 "md/raid:%s: read error not correctable "
                                  "(sector %llu on %s).\n",
                                  mdname(conf->mddev),
                                  (unsigned long long)(sh->sector
@@ -1538,7 +1539,7 @@ static void raid5_end_read_request(struct bio * bi, int error)
                else if (test_bit(R5_ReWrite, &sh->dev[i].flags))
                        /* Oh, no!!! */
                        printk_rl(KERN_WARNING
-                                 "raid5:%s: read error NOT corrected!! "
+                                 "md/raid:%s: read error NOT corrected!! "
                                  "(sector %llu on %s).\n",
                                  mdname(conf->mddev),
                                  (unsigned long long)(sh->sector
@@ -1547,7 +1548,7 @@ static void raid5_end_read_request(struct bio * bi, int error)
                else if (atomic_read(&rdev->read_errors)
                         > conf->max_nr_stripes)
                        printk(KERN_WARNING
-                              "raid5:%s: Too many read errors, failing device %s.\n",
+                              "md/raid:%s: Too many read errors, failing device %s.\n",
                               mdname(conf->mddev), bdn);
                else
                        retry = 1;
@@ -1619,8 +1620,8 @@ static void raid5_build_block(struct stripe_head *sh, int i, int previous)
 static void error(mddev_t *mddev, mdk_rdev_t *rdev)
 {
        char b[BDEVNAME_SIZE];
-       raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
-       pr_debug("raid5: error called\n");
+       raid5_conf_t *conf = mddev->private;
+       pr_debug("raid456: error called\n");
 
        if (!test_bit(Faulty, &rdev->flags)) {
                set_bit(MD_CHANGE_DEVS, &mddev->flags);
@@ -1636,9 +1637,13 @@ static void error(mddev_t *mddev, mdk_rdev_t *rdev)
                }
                set_bit(Faulty, &rdev->flags);
                printk(KERN_ALERT
-                      "raid5: Disk failure on %s, disabling device.\n"
-                      "raid5: Operation continuing on %d devices.\n",
-                      bdevname(rdev->bdev,b), conf->raid_disks - mddev->degraded);
+                      "md/raid:%s: Disk failure on %s, disabling device.\n"
+                      KERN_ALERT
+                      "md/raid:%s: Operation continuing on %d devices.\n",
+                      mdname(mddev),
+                      bdevname(rdev->bdev, b),
+                      mdname(mddev),
+                      conf->raid_disks - mddev->degraded);
        }
 }
 
@@ -1714,8 +1719,6 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
                        pd_idx = data_disks;
                        break;
                default:
-                       printk(KERN_ERR "raid5: unsupported algorithm %d\n",
-                               algorithm);
                        BUG();
                }
                break;
@@ -1832,10 +1835,7 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector,
                        qd_idx = raid_disks - 1;
                        break;
 
-
                default:
-                       printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
-                              algorithm);
                        BUG();
                }
                break;
@@ -1898,8 +1898,6 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
                case ALGORITHM_PARITY_N:
                        break;
                default:
-                       printk(KERN_ERR "raid5: unsupported algorithm %d\n",
-                              algorithm);
                        BUG();
                }
                break;
@@ -1958,8 +1956,6 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
                        i -= 1;
                        break;
                default:
-                       printk(KERN_CRIT "raid6: unsupported algorithm %d\n",
-                              algorithm);
                        BUG();
                }
                break;
@@ -1972,7 +1968,8 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous)
                                     previous, &dummy1, &sh2);
        if (check != sh->sector || dummy1 != dd_idx || sh2.pd_idx != sh->pd_idx
                || sh2.qd_idx != sh->qd_idx) {
-               printk(KERN_ERR "compute_blocknr: map not correct\n");
+               printk(KERN_ERR "md/raid:%s: compute_blocknr: map not correct\n",
+                      mdname(conf->mddev));
                return 0;
        }
        return r_sector;
@@ -3709,10 +3706,10 @@ static void raid5_align_endio(struct bio *bi, int error)
 
        bio_put(bi);
 
-       mddev = raid_bi->bi_bdev->bd_disk->queue->queuedata;
-       conf = mddev->private;
        rdev = (void*)raid_bi->bi_next;
        raid_bi->bi_next = NULL;
+       mddev = rdev->mddev;
+       conf = mddev->private;
 
        rdev_dec_pending(rdev, conf->mddev);
 
@@ -3749,9 +3746,8 @@ static int bio_fits_rdev(struct bio *bi)
 }
 
 
-static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio)
+static int chunk_aligned_read(mddev_t *mddev, struct bio * raid_bio)
 {
-       mddev_t *mddev = q->queuedata;
        raid5_conf_t *conf = mddev->private;
        int dd_idx;
        struct bio* align_bi;
@@ -3866,16 +3862,15 @@ static struct stripe_head *__get_priority_stripe(raid5_conf_t *conf)
        return sh;
 }
 
-static int make_request(struct request_queue *q, struct bio * bi)
+static int make_request(mddev_t *mddev, struct bio * bi)
 {
-       mddev_t *mddev = q->queuedata;
        raid5_conf_t *conf = mddev->private;
        int dd_idx;
        sector_t new_sector;
        sector_t logical_sector, last_sector;
        struct stripe_head *sh;
        const int rw = bio_data_dir(bi);
-       int cpu, remaining;
+       int remaining;
 
        if (unlikely(bio_rw_flagged(bi, BIO_RW_BARRIER))) {
                /* Drain all pending writes.  We only really need
@@ -3890,15 +3885,9 @@ static int make_request(struct request_queue *q, struct bio * bi)
 
        md_write_start(mddev, bi);
 
-       cpu = part_stat_lock();
-       part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
-       part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
-                     bio_sectors(bi));
-       part_stat_unlock();
-
        if (rw == READ &&
             mddev->reshape_position == MaxSector &&
-            chunk_aligned_read(q,bi))
+            chunk_aligned_read(mddev,bi))
                return 0;
 
        logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1);
@@ -3946,7 +3935,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
                new_sector = raid5_compute_sector(conf, logical_sector,
                                                  previous,
                                                  &dd_idx, NULL);
-               pr_debug("raid5: make_request, sector %llu logical %llu\n",
+               pr_debug("raid456: make_request, sector %llu logical %llu\n",
                        (unsigned long long)new_sector, 
                        (unsigned long long)logical_sector);
 
@@ -4054,7 +4043,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped
         * As the reads complete, handle_stripe will copy the data
         * into the destination stripe and release that stripe.
         */
-       raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+       raid5_conf_t *conf = mddev->private;
        struct stripe_head *sh;
        sector_t first_sector, last_sector;
        int raid_disks = conf->previous_raid_disks;
@@ -4263,7 +4252,7 @@ static sector_t reshape_request(mddev_t *mddev, sector_t sector_nr, int *skipped
 /* FIXME go_faster isn't used */
 static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
 {
-       raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+       raid5_conf_t *conf = mddev->private;
        struct stripe_head *sh;
        sector_t max_sector = mddev->dev_sectors;
        int sync_blocks;
@@ -4725,7 +4714,7 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
        if (mddev->new_level != 5
            && mddev->new_level != 4
            && mddev->new_level != 6) {
-               printk(KERN_ERR "raid5: %s: raid level not set to 4/5/6 (%d)\n",
+               printk(KERN_ERR "md/raid:%s: raid level not set to 4/5/6 (%d)\n",
                       mdname(mddev), mddev->new_level);
                return ERR_PTR(-EIO);
        }
@@ -4733,12 +4722,12 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
             && !algorithm_valid_raid5(mddev->new_layout)) ||
            (mddev->new_level == 6
             && !algorithm_valid_raid6(mddev->new_layout))) {
-               printk(KERN_ERR "raid5: %s: layout %d not supported\n",
+               printk(KERN_ERR "md/raid:%s: layout %d not supported\n",
                       mdname(mddev), mddev->new_layout);
                return ERR_PTR(-EIO);
        }
        if (mddev->new_level == 6 && mddev->raid_disks < 4) {
-               printk(KERN_ERR "raid6: not enough configured devices for %s (%d, minimum 4)\n",
+               printk(KERN_ERR "md/raid:%s: not enough configured devices (%d, minimum 4)\n",
                       mdname(mddev), mddev->raid_disks);
                return ERR_PTR(-EINVAL);
        }
@@ -4746,8 +4735,8 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
        if (!mddev->new_chunk_sectors ||
            (mddev->new_chunk_sectors << 9) % PAGE_SIZE ||
            !is_power_of_2(mddev->new_chunk_sectors)) {
-               printk(KERN_ERR "raid5: invalid chunk size %d for %s\n",
-                      mddev->new_chunk_sectors << 9, mdname(mddev));
+               printk(KERN_ERR "md/raid:%s: invalid chunk size %d\n",
+                      mdname(mddev), mddev->new_chunk_sectors << 9);
                return ERR_PTR(-EINVAL);
        }
 
@@ -4789,7 +4778,7 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
        if (raid5_alloc_percpu(conf) != 0)
                goto abort;
 
-       pr_debug("raid5: run(%s) called.\n", mdname(mddev));
+       pr_debug("raid456: run(%s) called.\n", mdname(mddev));
 
        list_for_each_entry(rdev, &mddev->disks, same_set) {
                raid_disk = rdev->raid_disk;
@@ -4802,9 +4791,9 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
 
                if (test_bit(In_sync, &rdev->flags)) {
                        char b[BDEVNAME_SIZE];
-                       printk(KERN_INFO "raid5: device %s operational as raid"
-                               " disk %d\n", bdevname(rdev->bdev,b),
-                               raid_disk);
+                       printk(KERN_INFO "md/raid:%s: device %s operational as raid"
+                              " disk %d\n",
+                              mdname(mddev), bdevname(rdev->bdev, b), raid_disk);
                } else
                        /* Cannot rely on bitmap to complete recovery */
                        conf->fullsync = 1;
@@ -4828,16 +4817,17 @@ static raid5_conf_t *setup_conf(mddev_t *mddev)
                 max_disks * ((sizeof(struct bio) + PAGE_SIZE))) / 1024;
        if (grow_stripes(conf, conf->max_nr_stripes)) {
                printk(KERN_ERR
-                       "raid5: couldn't allocate %dkB for buffers\n", memory);
+                      "md/raid:%s: couldn't allocate %dkB for buffers\n",
+                      mdname(mddev), memory);
                goto abort;
        } else
-               printk(KERN_INFO "raid5: allocated %dkB for %s\n",
-                       memory, mdname(mddev));
+               printk(KERN_INFO "md/raid:%s: allocated %dkB\n",
+                      mdname(mddev), memory);
 
        conf->thread = md_register_thread(raid5d, mddev, NULL);
        if (!conf->thread) {
                printk(KERN_ERR
-                      "raid5: couldn't allocate thread for %s\n",
+                      "md/raid:%s: couldn't allocate thread.\n",
                       mdname(mddev));
                goto abort;
        }
@@ -4888,7 +4878,7 @@ static int run(mddev_t *mddev)
        sector_t reshape_offset = 0;
 
        if (mddev->recovery_cp != MaxSector)
-               printk(KERN_NOTICE "raid5: %s is not clean"
+               printk(KERN_NOTICE "md/raid:%s: not clean"
                       " -- starting background reconstruction\n",
                       mdname(mddev));
        if (mddev->reshape_position != MaxSector) {
@@ -4902,7 +4892,7 @@ static int run(mddev_t *mddev)
                int max_degraded = (mddev->level == 6 ? 2 : 1);
 
                if (mddev->new_level != mddev->level) {
-                       printk(KERN_ERR "raid5: %s: unsupported reshape "
+                       printk(KERN_ERR "md/raid:%s: unsupported reshape "
                               "required - aborting.\n",
                               mdname(mddev));
                        return -EINVAL;
@@ -4915,8 +4905,8 @@ static int run(mddev_t *mddev)
                here_new = mddev->reshape_position;
                if (sector_div(here_new, mddev->new_chunk_sectors *
                               (mddev->raid_disks - max_degraded))) {
-                       printk(KERN_ERR "raid5: reshape_position not "
-                              "on a stripe boundary\n");
+                       printk(KERN_ERR "md/raid:%s: reshape_position not "
+                              "on a stripe boundary\n", mdname(mddev));
                        return -EINVAL;
                }
                reshape_offset = here_new * mddev->new_chunk_sectors;
@@ -4937,8 +4927,9 @@ static int run(mddev_t *mddev)
                        if ((here_new * mddev->new_chunk_sectors != 
                             here_old * mddev->chunk_sectors) ||
                            mddev->ro == 0) {
-                               printk(KERN_ERR "raid5: in-place reshape must be started"
-                                      " in read-only mode - aborting\n");
+                               printk(KERN_ERR "md/raid:%s: in-place reshape must be started"
+                                      " in read-only mode - aborting\n",
+                                      mdname(mddev));
                                return -EINVAL;
                        }
                } else if (mddev->delta_disks < 0
@@ -4947,11 +4938,13 @@ static int run(mddev_t *mddev)
                    : (here_new * mddev->new_chunk_sectors >=
                       here_old * mddev->chunk_sectors)) {
                        /* Reading from the same stripe as writing to - bad */
-                       printk(KERN_ERR "raid5: reshape_position too early for "
-                              "auto-recovery - aborting.\n");
+                       printk(KERN_ERR "md/raid:%s: reshape_position too early for "
+                              "auto-recovery - aborting.\n",
+                              mdname(mddev));
                        return -EINVAL;
                }
-               printk(KERN_INFO "raid5: reshape will continue\n");
+               printk(KERN_INFO "md/raid:%s: reshape will continue\n",
+                      mdname(mddev));
                /* OK, we should be able to continue; */
        } else {
                BUG_ON(mddev->level != mddev->new_level);
@@ -4993,18 +4986,6 @@ static int run(mddev_t *mddev)
                    mddev->minor_version > 90)
                        rdev->recovery_offset = reshape_offset;
                        
-               printk("%d: w=%d pa=%d pr=%d m=%d a=%d r=%d op1=%d op2=%d\n",
-                      rdev->raid_disk, working_disks, conf->prev_algo,
-                      conf->previous_raid_disks, conf->max_degraded,
-                      conf->algorithm, conf->raid_disks, 
-                      only_parity(rdev->raid_disk,
-                                  conf->prev_algo,
-                                  conf->previous_raid_disks,
-                                  conf->max_degraded),
-                      only_parity(rdev->raid_disk,
-                                  conf->algorithm,
-                                  conf->raid_disks,
-                                  conf->max_degraded));
                if (rdev->recovery_offset < reshape_offset) {
                        /* We need to check old and new layout */
                        if (!only_parity(rdev->raid_disk,
@@ -5025,7 +5006,7 @@ static int run(mddev_t *mddev)
                           - working_disks);
 
        if (mddev->degraded > conf->max_degraded) {
-               printk(KERN_ERR "raid5: not enough operational devices for %s"
+               printk(KERN_ERR "md/raid:%s: not enough operational devices"
                        " (%d/%d failed)\n",
                        mdname(mddev), mddev->degraded, conf->raid_disks);
                goto abort;
@@ -5039,32 +5020,32 @@ static int run(mddev_t *mddev)
            mddev->recovery_cp != MaxSector) {
                if (mddev->ok_start_degraded)
                        printk(KERN_WARNING
-                              "raid5: starting dirty degraded array: %s"
-                              "- data corruption possible.\n",
+                              "md/raid:%s: starting dirty degraded array"
+                              " - data corruption possible.\n",
                               mdname(mddev));
                else {
                        printk(KERN_ERR
-                              "raid5: cannot start dirty degraded array for %s\n",
+                              "md/raid:%s: cannot start dirty degraded array.\n",
                               mdname(mddev));
                        goto abort;
                }
        }
 
        if (mddev->degraded == 0)
-               printk("raid5: raid level %d set %s active with %d out of %d"
-                      " devices, algorithm %d\n", conf->level, mdname(mddev),
+               printk(KERN_INFO "md/raid:%s: raid level %d active with %d out of %d"
+                      " devices, algorithm %d\n", mdname(mddev), conf->level,
                       mddev->raid_disks-mddev->degraded, mddev->raid_disks,
                       mddev->new_layout);
        else
-               printk(KERN_ALERT "raid5: raid level %d set %s active with %d"
-                       " out of %d devices, algorithm %d\n", conf->level,
-                       mdname(mddev), mddev->raid_disks - mddev->degraded,
-                       mddev->raid_disks, mddev->new_layout);
+               printk(KERN_ALERT "md/raid:%s: raid level %d active with %d"
+                      " out of %d devices, algorithm %d\n",
+                      mdname(mddev), conf->level,
+                      mddev->raid_disks - mddev->degraded,
+                      mddev->raid_disks, mddev->new_layout);
 
        print_raid5_conf(conf);
 
        if (conf->reshape_progress != MaxSector) {
-               printk("...ok start reshape thread\n");
                conf->reshape_safe = conf->reshape_progress;
                atomic_set(&conf->reshape_stripes, 0);
                clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
@@ -5087,9 +5068,11 @@ static int run(mddev_t *mddev)
        }
 
        /* Ok, everything is just fine now */
-       if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
+       if (mddev->to_remove == &raid5_attrs_group)
+               mddev->to_remove = NULL;
+       else if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
                printk(KERN_WARNING
-                      "raid5: failed to create sysfs attributes for %s\n",
+                      "md/raid:%s: failed to create sysfs attributes.\n",
                       mdname(mddev));
 
        mddev->queue->queue_lock = &conf->device_lock;
@@ -5119,22 +5102,21 @@ abort:
                free_conf(conf);
        }
        mddev->private = NULL;
-       printk(KERN_ALERT "raid5: failed to run raid set %s\n", mdname(mddev));
+       printk(KERN_ALERT "md/raid:%s: failed to run raid set.\n", mdname(mddev));
        return -EIO;
 }
 
-
-
 static int stop(mddev_t *mddev)
 {
-       raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+       raid5_conf_t *conf = mddev->private;
 
        md_unregister_thread(mddev->thread);
        mddev->thread = NULL;
        mddev->queue->backing_dev_info.congested_fn = NULL;
        blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
        free_conf(conf);
-       mddev->private = &raid5_attrs_group;
+       mddev->private = NULL;
+       mddev->to_remove = &raid5_attrs_group;
        return 0;
 }
 
@@ -5175,7 +5157,7 @@ static void printall(struct seq_file *seq, raid5_conf_t *conf)
 
 static void status(struct seq_file *seq, mddev_t *mddev)
 {
-       raid5_conf_t *conf = (raid5_conf_t *) mddev->private;
+       raid5_conf_t *conf = mddev->private;
        int i;
 
        seq_printf(seq, " level %d, %dk chunk, algorithm %d", mddev->level,
@@ -5197,21 +5179,22 @@ static void print_raid5_conf (raid5_conf_t *conf)
        int i;
        struct disk_info *tmp;
 
-       printk("RAID5 conf printout:\n");
+       printk(KERN_DEBUG "RAID conf printout:\n");
        if (!conf) {
                printk("(conf==NULL)\n");
                return;
        }
-       printk(" --- rd:%d wd:%d\n", conf->raid_disks,
-                conf->raid_disks - conf->mddev->degraded);
+       printk(KERN_DEBUG " --- level:%d rd:%d wd:%d\n", conf->level,
+              conf->raid_disks,
+              conf->raid_disks - conf->mddev->degraded);
 
        for (i = 0; i < conf->raid_disks; i++) {
                char b[BDEVNAME_SIZE];
                tmp = conf->disks + i;
                if (tmp->rdev)
-               printk(" disk %d, o:%d, dev:%s\n",
-                       i, !test_bit(Faulty, &tmp->rdev->flags),
-                       bdevname(tmp->rdev->bdev,b));
+                       printk(KERN_DEBUG " disk %d, o:%d, dev:%s\n",
+                              i, !test_bit(Faulty, &tmp->rdev->flags),
+                              bdevname(tmp->rdev->bdev, b));
        }
 }
 
@@ -5334,7 +5317,6 @@ static int raid5_resize(mddev_t *mddev, sector_t sectors)
            raid5_size(mddev, sectors, mddev->raid_disks))
                return -EINVAL;
        set_capacity(mddev->gendisk, mddev->array_sectors);
-       mddev->changed = 1;
        revalidate_disk(mddev->gendisk);
        if (sectors > mddev->dev_sectors && mddev->recovery_cp == MaxSector) {
                mddev->recovery_cp = mddev->dev_sectors;
@@ -5360,7 +5342,8 @@ static int check_stripe_cache(mddev_t *mddev)
            > conf->max_nr_stripes ||
            ((mddev->new_chunk_sectors << 9) / STRIPE_SIZE) * 4
            > conf->max_nr_stripes) {
-               printk(KERN_WARNING "raid5: reshape: not enough stripes.  Needed %lu\n",
+               printk(KERN_WARNING "md/raid:%s: reshape: not enough stripes.  Needed %lu\n",
+                      mdname(mddev),
                       ((max(mddev->chunk_sectors, mddev->new_chunk_sectors) << 9)
                        / STRIPE_SIZE)*4);
                return 0;
@@ -5431,7 +5414,7 @@ static int raid5_start_reshape(mddev_t *mddev)
         */
        if (raid5_size(mddev, 0, conf->raid_disks + mddev->delta_disks)
            < mddev->array_sectors) {
-               printk(KERN_ERR "md%s: array size must be reduced "
+               printk(KERN_ERR "md/raid:%s: array size must be reduced "
                       "before number of disks\n", mdname(mddev));
                return -EINVAL;
        }
@@ -5469,9 +5452,9 @@ static int raid5_start_reshape(mddev_t *mddev)
                                if (sysfs_create_link(&mddev->kobj,
                                                      &rdev->kobj, nm))
                                        printk(KERN_WARNING
-                                              "raid5: failed to create "
-                                              " link %s for %s\n",
-                                              nm, mdname(mddev));
+                                              "md/raid:%s: failed to create "
+                                              " link %s\n",
+                                              mdname(mddev), nm);
                        } else
                                break;
                }
@@ -5548,7 +5531,6 @@ static void raid5_finish_reshape(mddev_t *mddev)
                if (mddev->delta_disks > 0) {
                        md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
                        set_capacity(mddev->gendisk, mddev->array_sectors);
-                       mddev->changed = 1;
                        revalidate_disk(mddev->gendisk);
                } else {
                        int d;
@@ -5613,6 +5595,29 @@ static void raid5_quiesce(mddev_t *mddev, int state)
 }
 
 
+static void *raid45_takeover_raid0(mddev_t *mddev, int level)
+{
+       struct raid0_private_data *raid0_priv = mddev->private;
+
+       /* for raid0 takeover only one zone is supported */
+       if (raid0_priv->nr_strip_zones > 1) {
+               printk(KERN_ERR "md/raid:%s: cannot takeover raid0 with more than one zone.\n",
+                      mdname(mddev));
+               return ERR_PTR(-EINVAL);
+       }
+
+       mddev->new_level = level;
+       mddev->new_layout = ALGORITHM_PARITY_N;
+       mddev->new_chunk_sectors = mddev->chunk_sectors;
+       mddev->raid_disks += 1;
+       mddev->delta_disks = 1;
+       /* make sure it will be not marked as dirty */
+       mddev->recovery_cp = MaxSector;
+
+       return setup_conf(mddev);
+}
+
+
 static void *raid5_takeover_raid1(mddev_t *mddev)
 {
        int chunksect;
@@ -5737,12 +5742,13 @@ static int raid6_check_reshape(mddev_t *mddev)
 static void *raid5_takeover(mddev_t *mddev)
 {
        /* raid5 can take over:
-        *  raid0 - if all devices are the same - make it a raid4 layout
+        *  raid0 - if there is only one strip zone - make it a raid4 layout
         *  raid1 - if there are two drives.  We need to know the chunk size
         *  raid4 - trivial - just use a raid4 layout.
         *  raid6 - Providing it is a *_6 layout
         */
-
+       if (mddev->level == 0)
+               return raid45_takeover_raid0(mddev, 5);
        if (mddev->level == 1)
                return raid5_takeover_raid1(mddev);
        if (mddev->level == 4) {
@@ -5756,6 +5762,22 @@ static void *raid5_takeover(mddev_t *mddev)
        return ERR_PTR(-EINVAL);
 }
 
+static void *raid4_takeover(mddev_t *mddev)
+{
+       /* raid4 can take over:
+        *  raid0 - if there is only one strip zone
+        *  raid5 - if layout is right
+        */
+       if (mddev->level == 0)
+               return raid45_takeover_raid0(mddev, 4);
+       if (mddev->level == 5 &&
+           mddev->layout == ALGORITHM_PARITY_N) {
+               mddev->new_layout = 0;
+               mddev->new_level = 4;
+               return setup_conf(mddev);
+       }
+       return ERR_PTR(-EINVAL);
+}
 
 static struct mdk_personality raid5_personality;
 
@@ -5871,6 +5893,7 @@ static struct mdk_personality raid4_personality =
        .start_reshape  = raid5_start_reshape,
        .finish_reshape = raid5_finish_reshape,
        .quiesce        = raid5_quiesce,
+       .takeover       = raid4_takeover,
 };
 
 static int __init raid5_init(void)