md: constify VFTs
[safe/jmp/linux-2.6] / drivers / md / md.c
index 41e2509..8350bde 100644 (file)
@@ -33,9 +33,9 @@
 */
 
 #include <linux/kthread.h>
-#include <linux/raid/md.h>
-#include <linux/raid/bitmap.h>
+#include <linux/blkdev.h>
 #include <linux/sysctl.h>
+#include <linux/seq_file.h>
 #include <linux/buffer_head.h> /* for invalidate_bdev */
 #include <linux/poll.h>
 #include <linux/ctype.h>
 #include <linux/reboot.h>
 #include <linux/file.h>
 #include <linux/delay.h>
-
-#define MAJOR_NR MD_MAJOR
-
-/* 63 partitions with the alternate major number (mdp) */
-#define MdpMinorShift 6
+#include <linux/raid/md_p.h>
+#include <linux/raid/md_u.h>
+#include "md.h"
+#include "bitmap.h"
 
 #define DEBUG 0
 #define dprintk(x...) ((void)(DEBUG && printk(x)))
@@ -202,24 +201,75 @@ static DEFINE_SPINLOCK(all_mddevs_lock);
                )
 
 
-static int md_fail_request(struct request_queue *q, struct bio *bio)
+/* Rather than calling directly into the personality make_request function,
+ * IO requests come here first so that we can check if the device is
+ * being suspended pending a reconfiguration.
+ * We hold a refcount over the call to ->make_request.  By the time that
+ * call has finished, the bio has been linked into some internal structure
+ * and so is visible to ->quiesce(), so we don't need the refcount any more.
+ */
+static int md_make_request(struct request_queue *q, struct bio *bio)
 {
-       bio_io_error(bio);
-       return 0;
+       mddev_t *mddev = q->queuedata;
+       int rv;
+       if (mddev == NULL || mddev->pers == NULL) {
+               bio_io_error(bio);
+               return 0;
+       }
+       rcu_read_lock();
+       if (mddev->suspended) {
+               DEFINE_WAIT(__wait);
+               for (;;) {
+                       prepare_to_wait(&mddev->sb_wait, &__wait,
+                                       TASK_UNINTERRUPTIBLE);
+                       if (!mddev->suspended)
+                               break;
+                       rcu_read_unlock();
+                       schedule();
+                       rcu_read_lock();
+               }
+               finish_wait(&mddev->sb_wait, &__wait);
+       }
+       atomic_inc(&mddev->active_io);
+       rcu_read_unlock();
+       rv = mddev->pers->make_request(q, bio);
+       if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)
+               wake_up(&mddev->sb_wait);
+
+       return rv;
 }
 
+static void mddev_suspend(mddev_t *mddev)
+{
+       BUG_ON(mddev->suspended);
+       mddev->suspended = 1;
+       synchronize_rcu();
+       wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
+       mddev->pers->quiesce(mddev, 1);
+       md_unregister_thread(mddev->thread);
+       mddev->thread = NULL;
+       /* we now know that no code is executing in the personality module,
+        * except possibly the tail end of a ->bi_end_io function, but that
+        * is certain to complete before the module has a chance to get
+        * unloaded
+        */
+}
+
+static void mddev_resume(mddev_t *mddev)
+{
+       mddev->suspended = 0;
+       wake_up(&mddev->sb_wait);
+       mddev->pers->quiesce(mddev, 0);
+}
+
+
 static inline mddev_t *mddev_get(mddev_t *mddev)
 {
        atomic_inc(&mddev->active);
        return mddev;
 }
 
-static void mddev_delayed_delete(struct work_struct *ws)
-{
-       mddev_t *mddev = container_of(ws, mddev_t, del_work);
-       kobject_del(&mddev->kobj);
-       kobject_put(&mddev->kobj);
-}
+static void mddev_delayed_delete(struct work_struct *ws);
 
 static void mddev_put(mddev_t *mddev)
 {
@@ -315,6 +365,7 @@ static mddev_t * mddev_find(dev_t unit)
        init_timer(&new->safemode_timer);
        atomic_set(&new->active, 1);
        atomic_set(&new->openers, 0);
+       atomic_set(&new->active_io, 0);
        spin_lock_init(&new->write_lock);
        init_waitqueue_head(&new->sb_wait);
        init_waitqueue_head(&new->recovery_wait);
@@ -331,6 +382,11 @@ static inline int mddev_lock(mddev_t * mddev)
        return mutex_lock_interruptible(&mddev->reconfig_mutex);
 }
 
+static inline int mddev_is_locked(mddev_t *mddev)
+{
+       return mutex_is_locked(&mddev->reconfig_mutex);
+}
+
 static inline int mddev_trylock(mddev_t * mddev)
 {
        return mutex_trylock(&mddev->reconfig_mutex);
@@ -414,7 +470,7 @@ static void free_disk_sb(mdk_rdev_t * rdev)
                rdev->sb_loaded = 0;
                rdev->sb_page = NULL;
                rdev->sb_start = 0;
-               rdev->size = 0;
+               rdev->sectors = 0;
        }
 }
 
@@ -474,7 +530,7 @@ void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
         * causes ENOTSUPP, we allocate a spare bio...
         */
        struct bio *bio = bio_alloc(GFP_NOIO, 1);
-       int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNC);
+       int rw = (1<<BIO_RW) | (1<<BIO_RW_SYNCIO) | (1<<BIO_RW_UNPLUG);
 
        bio->bi_bdev = rdev->bdev;
        bio->bi_sector = sector;
@@ -531,7 +587,7 @@ int sync_page_io(struct block_device *bdev, sector_t sector, int size,
        struct completion event;
        int ret;
 
-       rw |= (1 << BIO_RW_SYNC);
+       rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
 
        bio->bi_bdev = bdev;
        bio->bi_sector = sector;
@@ -780,9 +836,9 @@ static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version
                else 
                        ret = 0;
        }
-       rdev->size = calc_num_sectors(rdev, sb->chunk_size) / 2;
+       rdev->sectors = calc_num_sectors(rdev, sb->chunk_size);
 
-       if (rdev->size < sb->size && sb->level > 1)
+       if (rdev->sectors < sb->size * 2 && sb->level > 1)
                /* "this cannot possibly happen" ... */
                ret = -EINVAL;
 
@@ -817,7 +873,7 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                mddev->clevel[0] = 0;
                mddev->layout = sb->layout;
                mddev->raid_disks = sb->raid_disks;
-               mddev->size = sb->size;
+               mddev->dev_sectors = sb->size * 2;
                mddev->events = ev1;
                mddev->bitmap_offset = 0;
                mddev->default_bitmap_offset = MD_SB_BYTES >> 9;
@@ -931,7 +987,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 
        sb->ctime = mddev->ctime;
        sb->level = mddev->level;
-       sb->size  = mddev->size;
+       sb->size = mddev->dev_sectors / 2;
        sb->raid_disks = mddev->raid_disks;
        sb->md_minor = mddev->md_minor;
        sb->not_persistent = 0;
@@ -1029,7 +1085,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 static unsigned long long
 super_90_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
 {
-       if (num_sectors && num_sectors < rdev->mddev->size * 2)
+       if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
                return 0; /* component must fit device */
        if (rdev->mddev->bitmap_offset)
                return 0; /* can't move bitmap */
@@ -1185,16 +1241,17 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
                        ret = 0;
        }
        if (minor_version)
-               rdev->size = ((rdev->bdev->bd_inode->i_size>>9) - le64_to_cpu(sb->data_offset)) / 2;
+               rdev->sectors = (rdev->bdev->bd_inode->i_size >> 9) -
+                       le64_to_cpu(sb->data_offset);
        else
-               rdev->size = rdev->sb_start / 2;
-       if (rdev->size < le64_to_cpu(sb->data_size)/2)
+               rdev->sectors = rdev->sb_start;
+       if (rdev->sectors < le64_to_cpu(sb->data_size))
                return -EINVAL;
-       rdev->size = le64_to_cpu(sb->data_size)/2;
+       rdev->sectors = le64_to_cpu(sb->data_size);
        if (le32_to_cpu(sb->chunksize))
-               rdev->size &= ~((sector_t)le32_to_cpu(sb->chunksize)/2 - 1);
+               rdev->sectors &= ~((sector_t)le32_to_cpu(sb->chunksize) - 1);
 
-       if (le64_to_cpu(sb->size) > rdev->size*2)
+       if (le64_to_cpu(sb->size) > rdev->sectors)
                return -EINVAL;
        return ret;
 }
@@ -1221,7 +1278,7 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                mddev->clevel[0] = 0;
                mddev->layout = le32_to_cpu(sb->layout);
                mddev->raid_disks = le32_to_cpu(sb->raid_disks);
-               mddev->size = le64_to_cpu(sb->size)/2;
+               mddev->dev_sectors = le64_to_cpu(sb->size);
                mddev->events = ev1;
                mddev->bitmap_offset = 0;
                mddev->default_bitmap_offset = 1024 >> 9;
@@ -1317,7 +1374,7 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
        sb->cnt_corrected_read = cpu_to_le32(atomic_read(&rdev->corrected_errors));
 
        sb->raid_disks = cpu_to_le32(mddev->raid_disks);
-       sb->size = cpu_to_le64(mddev->size<<1);
+       sb->size = cpu_to_le64(mddev->dev_sectors);
 
        if (mddev->bitmap && mddev->bitmap_file == NULL) {
                sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_offset);
@@ -1325,10 +1382,15 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
        }
 
        if (rdev->raid_disk >= 0 &&
-           !test_bit(In_sync, &rdev->flags) &&
-           rdev->recovery_offset > 0) {
-               sb->feature_map |= cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
-               sb->recovery_offset = cpu_to_le64(rdev->recovery_offset);
+           !test_bit(In_sync, &rdev->flags)) {
+               if (mddev->curr_resync_completed > rdev->recovery_offset)
+                       rdev->recovery_offset = mddev->curr_resync_completed;
+               if (rdev->recovery_offset > 0) {
+                       sb->feature_map |=
+                               cpu_to_le32(MD_FEATURE_RECOVERY_OFFSET);
+                       sb->recovery_offset =
+                               cpu_to_le64(rdev->recovery_offset);
+               }
        }
 
        if (mddev->reshape_position != MaxSector) {
@@ -1370,7 +1432,7 @@ super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
 {
        struct mdp_superblock_1 *sb;
        sector_t max_sectors;
-       if (num_sectors && num_sectors < rdev->mddev->size * 2)
+       if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
                return 0; /* component must fit device */
        if (rdev->sb_start < rdev->data_offset) {
                /* minor versions 1 and 2; superblock before data */
@@ -1386,7 +1448,7 @@ super_1_rdev_size_change(mdk_rdev_t *rdev, sector_t num_sectors)
                sector_t sb_start;
                sb_start = (rdev->bdev->bd_inode->i_size >> 9) - 8*2;
                sb_start &= ~(sector_t)(4*2 - 1);
-               max_sectors = rdev->size * 2 + sb_start - rdev->sb_start;
+               max_sectors = rdev->sectors + sb_start - rdev->sb_start;
                if (!num_sectors || num_sectors > max_sectors)
                        num_sectors = max_sectors;
                rdev->sb_start = sb_start;
@@ -1438,6 +1500,38 @@ static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
 
 static LIST_HEAD(pending_raid_disks);
 
+static void md_integrity_check(mdk_rdev_t *rdev, mddev_t *mddev)
+{
+       struct mdk_personality *pers = mddev->pers;
+       struct gendisk *disk = mddev->gendisk;
+       struct blk_integrity *bi_rdev = bdev_get_integrity(rdev->bdev);
+       struct blk_integrity *bi_mddev = blk_get_integrity(disk);
+
+       /* Data integrity passthrough not supported on RAID 4, 5 and 6 */
+       if (pers && pers->level >= 4 && pers->level <= 6)
+               return;
+
+       /* If rdev is integrity capable, register profile for mddev */
+       if (!bi_mddev && bi_rdev) {
+               if (blk_integrity_register(disk, bi_rdev))
+                       printk(KERN_ERR "%s: %s Could not register integrity!\n",
+                              __func__, disk->disk_name);
+               else
+                       printk(KERN_NOTICE "Enabling data integrity on %s\n",
+                              disk->disk_name);
+               return;
+       }
+
+       /* Check that mddev and rdev have matching profiles */
+       if (blk_integrity_compare(disk, rdev->bdev->bd_disk) < 0) {
+               printk(KERN_ERR "%s: %s/%s integrity mismatch!\n", __func__,
+                      disk->disk_name, rdev->bdev->bd_disk->disk_name);
+               printk(KERN_NOTICE "Disabling data integrity on %s\n",
+                      disk->disk_name);
+               blk_integrity_unregister(disk);
+       }
+}
+
 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
 {
        char b[BDEVNAME_SIZE];
@@ -1454,8 +1548,9 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
        if (find_rdev(mddev, rdev->bdev->bd_dev))
                return -EEXIST;
 
-       /* make sure rdev->size exceeds mddev->size */
-       if (rdev->size && (mddev->size == 0 || rdev->size < mddev->size)) {
+       /* make sure rdev->sectors exceeds mddev->dev_sectors */
+       if (rdev->sectors && (mddev->dev_sectors == 0 ||
+                       rdev->sectors < mddev->dev_sectors)) {
                if (mddev->pers) {
                        /* Cannot change size, so fail
                         * If mddev->level <= 0, then we don't care
@@ -1464,7 +1559,7 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
                        if (mddev->level > 0)
                                return -ENOSPC;
                } else
-                       mddev->size = rdev->size;
+                       mddev->dev_sectors = rdev->sectors;
        }
 
        /* Verify rdev->desc_nr is unique.
@@ -1481,6 +1576,11 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
                if (find_rdev_nr(mddev, rdev->desc_nr))
                        return -EBUSY;
        }
+       if (mddev->max_disks && rdev->desc_nr >= mddev->max_disks) {
+               printk(KERN_WARNING "md: %s: array is limited to %d devices\n",
+                      mdname(mddev), mddev->max_disks);
+               return -EBUSY;
+       }
        bdevname(rdev->bdev,b);
        while ( (s=strchr(b, '/')) != NULL)
                *s = '!';
@@ -1503,6 +1603,8 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
 
        /* May as well allow recovery to be retried once */
        mddev->recovery_disabled = 0;
+
+       md_integrity_check(rdev, mddev);
        return 0;
 
  fail:
@@ -1713,8 +1815,8 @@ static void print_sb_1(struct mdp_superblock_1 *sb)
 static void print_rdev(mdk_rdev_t *rdev, int major_version)
 {
        char b[BDEVNAME_SIZE];
-       printk(KERN_INFO "md: rdev %s, SZ:%08llu F:%d S:%d DN:%u\n",
-               bdevname(rdev->bdev,b), (unsigned long long)rdev->size,
+       printk(KERN_INFO "md: rdev %s, Sect:%08llu F:%d S:%d DN:%u\n",
+               bdevname(rdev->bdev, b), (unsigned long long)rdev->sectors,
                test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
                rdev->desc_nr);
        if (rdev->sb_loaded) {
@@ -1915,6 +2017,8 @@ repeat:
        clear_bit(MD_CHANGE_PENDING, &mddev->flags);
        spin_unlock_irq(&mddev->write_lock);
        wake_up(&mddev->sb_wait);
+       if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
+               sysfs_notify(&mddev->kobj, NULL, "sync_completed");
 
 }
 
@@ -1984,6 +2088,7 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
         *  -writemostly - clears write_mostly
         *  blocked - sets the Blocked flag
         *  -blocked - clears the Blocked flag
+        *  insync - sets Insync providing device isn't active
         */
        int err = -EINVAL;
        if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
@@ -2016,6 +2121,9 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                md_wakeup_thread(rdev->mddev->thread);
 
                err = 0;
+       } else if (cmd_match(buf, "insync") && rdev->raid_disk == -1) {
+               set_bit(In_sync, &rdev->flags);
+               err = 0;
        }
        if (!err && rdev->sysfs_state)
                sysfs_notify_dirent(rdev->sysfs_state);
@@ -2088,7 +2196,7 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
        } else if (rdev->mddev->pers) {
                mdk_rdev_t *rdev2;
                /* Activating a spare .. or possibly reactivating
-                * if we every get bitmaps working here.
+                * if we ever get bitmaps working here.
                 */
 
                if (rdev->raid_disk != -1)
@@ -2153,7 +2261,7 @@ offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                return -EINVAL;
        if (rdev->mddev->pers && rdev->raid_disk >= 0)
                return -EBUSY;
-       if (rdev->size && rdev->mddev->external)
+       if (rdev->sectors && rdev->mddev->external)
                /* Must set offset before size, so overlap checks
                 * can be sane */
                return -EBUSY;
@@ -2167,7 +2275,7 @@ __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
 static ssize_t
 rdev_size_show(mdk_rdev_t *rdev, char *page)
 {
-       return sprintf(page, "%llu\n", (unsigned long long)rdev->size);
+       return sprintf(page, "%llu\n", (unsigned long long)rdev->sectors / 2);
 }
 
 static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
@@ -2180,34 +2288,52 @@ static int overlaps(sector_t s1, sector_t l1, sector_t s2, sector_t l2)
        return 1;
 }
 
+static int strict_blocks_to_sectors(const char *buf, sector_t *sectors)
+{
+       unsigned long long blocks;
+       sector_t new;
+
+       if (strict_strtoull(buf, 10, &blocks) < 0)
+               return -EINVAL;
+
+       if (blocks & 1ULL << (8 * sizeof(blocks) - 1))
+               return -EINVAL; /* sector conversion overflow */
+
+       new = blocks * 2;
+       if (new != blocks * 2)
+               return -EINVAL; /* unsigned long long to sector_t overflow */
+
+       *sectors = new;
+       return 0;
+}
+
 static ssize_t
 rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
 {
-       unsigned long long size;
-       unsigned long long oldsize = rdev->size;
        mddev_t *my_mddev = rdev->mddev;
+       sector_t oldsectors = rdev->sectors;
+       sector_t sectors;
 
-       if (strict_strtoull(buf, 10, &size) < 0)
+       if (strict_blocks_to_sectors(buf, &sectors) < 0)
                return -EINVAL;
        if (my_mddev->pers && rdev->raid_disk >= 0) {
                if (my_mddev->persistent) {
-                       size = super_types[my_mddev->major_version].
-                               rdev_size_change(rdev, size * 2);
-                       if (!size)
+                       sectors = super_types[my_mddev->major_version].
+                               rdev_size_change(rdev, sectors);
+                       if (!sectors)
                                return -EBUSY;
-               } else if (!size) {
-                       size = (rdev->bdev->bd_inode->i_size >> 10);
-                       size -= rdev->data_offset/2;
-               }
+               } else if (!sectors)
+                       sectors = (rdev->bdev->bd_inode->i_size >> 9) -
+                               rdev->data_offset;
        }
-       if (size < my_mddev->size)
+       if (sectors < my_mddev->dev_sectors)
                return -EINVAL; /* component must fit device */
 
-       rdev->size = size;
-       if (size > oldsize && my_mddev->external) {
+       rdev->sectors = sectors;
+       if (sectors > oldsectors && my_mddev->external) {
                /* need to check that all other rdevs with the same ->bdev
                 * do not overlap.  We need to unlock the mddev to avoid
-                * a deadlock.  We have already changed rdev->size, and if
+                * a deadlock.  We have already changed rdev->sectors, and if
                 * we have to change it back, we will have the lock again.
                 */
                mddev_t *mddev;
@@ -2223,9 +2349,9 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                                if (test_bit(AllReserved, &rdev2->flags) ||
                                    (rdev->bdev == rdev2->bdev &&
                                     rdev != rdev2 &&
-                                    overlaps(rdev->data_offset, rdev->size * 2,
+                                    overlaps(rdev->data_offset, rdev->sectors,
                                              rdev2->data_offset,
-                                             rdev2->size * 2))) {
+                                             rdev2->sectors))) {
                                        overlap = 1;
                                        break;
                                }
@@ -2239,11 +2365,11 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                if (overlap) {
                        /* Someone else could have slipped in a size
                         * change here, but doing so is just silly.
-                        * We put oldsize back because we *know* it is
+                        * We put oldsectors back because we *know* it is
                         * safe, and trust userspace not to race with
                         * itself
                         */
-                       rdev->size = oldsize;
+                       rdev->sectors = oldsectors;
                        return -EBUSY;
                }
        }
@@ -2441,6 +2567,15 @@ static void analyze_sbs(mddev_t * mddev)
 
        i = 0;
        rdev_for_each(rdev, tmp, mddev) {
+               if (rdev->desc_nr >= mddev->max_disks ||
+                   i > mddev->max_disks) {
+                       printk(KERN_WARNING
+                              "md: %s: %s: only %d devices permitted\n",
+                              mdname(mddev), bdevname(rdev->bdev, b),
+                              mddev->max_disks);
+                       kick_rdev_from_array(rdev);
+                       continue;
+               }
                if (rdev != freshest)
                        if (super_types[mddev->major_version].
                            validate_super(mddev, rdev)) {
@@ -2538,18 +2673,101 @@ level_show(mddev_t *mddev, char *page)
 static ssize_t
 level_store(mddev_t *mddev, const char *buf, size_t len)
 {
+       char level[16];
        ssize_t rv = len;
-       if (mddev->pers)
+       struct mdk_personality *pers;
+       void *priv;
+
+       if (mddev->pers == NULL) {
+               if (len == 0)
+                       return 0;
+               if (len >= sizeof(mddev->clevel))
+                       return -ENOSPC;
+               strncpy(mddev->clevel, buf, len);
+               if (mddev->clevel[len-1] == '\n')
+                       len--;
+               mddev->clevel[len] = 0;
+               mddev->level = LEVEL_NONE;
+               return rv;
+       }
+
+       /* request to change the personality.  Need to ensure:
+        *  - array is not engaged in resync/recovery/reshape
+        *  - old personality can be suspended
+        *  - new personality will access other array.
+        */
+
+       if (mddev->sync_thread || mddev->reshape_position != MaxSector)
                return -EBUSY;
-       if (len == 0)
-               return 0;
-       if (len >= sizeof(mddev->clevel))
-               return -ENOSPC;
-       strncpy(mddev->clevel, buf, len);
-       if (mddev->clevel[len-1] == '\n')
+
+       if (!mddev->pers->quiesce) {
+               printk(KERN_WARNING "md: %s: %s does not support online personality change\n",
+                      mdname(mddev), mddev->pers->name);
+               return -EINVAL;
+       }
+
+       /* Now find the new personality */
+       if (len == 0 || len >= sizeof(level))
+               return -EINVAL;
+       strncpy(level, buf, len);
+       if (level[len-1] == '\n')
                len--;
-       mddev->clevel[len] = 0;
-       mddev->level = LEVEL_NONE;
+       level[len] = 0;
+
+       request_module("md-%s", level);
+       spin_lock(&pers_lock);
+       pers = find_pers(LEVEL_NONE, level);
+       if (!pers || !try_module_get(pers->owner)) {
+               spin_unlock(&pers_lock);
+               printk(KERN_WARNING "md: personality %s not loaded\n", level);
+               return -EINVAL;
+       }
+       spin_unlock(&pers_lock);
+
+       if (pers == mddev->pers) {
+               /* Nothing to do! */
+               module_put(pers->owner);
+               return rv;
+       }
+       if (!pers->takeover) {
+               module_put(pers->owner);
+               printk(KERN_WARNING "md: %s: %s does not support personality takeover\n",
+                      mdname(mddev), level);
+               return -EINVAL;
+       }
+
+       /* ->takeover must set new_* and/or delta_disks
+        * if it succeeds, and may set them when it fails.
+        */
+       priv = pers->takeover(mddev);
+       if (IS_ERR(priv)) {
+               mddev->new_level = mddev->level;
+               mddev->new_layout = mddev->layout;
+               mddev->new_chunk = mddev->chunk_size;
+               mddev->raid_disks -= mddev->delta_disks;
+               mddev->delta_disks = 0;
+               module_put(pers->owner);
+               printk(KERN_WARNING "md: %s: %s would not accept array\n",
+                      mdname(mddev), level);
+               return PTR_ERR(priv);
+       }
+
+       /* Looks like we have a winner */
+       mddev_suspend(mddev);
+       mddev->pers->stop(mddev);
+       module_put(mddev->pers->owner);
+       mddev->pers = pers;
+       mddev->private = priv;
+       strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
+       mddev->level = mddev->new_level;
+       mddev->layout = mddev->new_layout;
+       mddev->chunk_size = mddev->new_chunk;
+       mddev->delta_disks = 0;
+       pers->run(mddev);
+       mddev_resume(mddev);
+       set_bit(MD_CHANGE_DEVS, &mddev->flags);
+       set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+       md_wakeup_thread(mddev->thread);
        return rv;
 }
 
@@ -2577,12 +2795,18 @@ layout_store(mddev_t *mddev, const char *buf, size_t len)
        if (!*buf || (*e && *e != '\n'))
                return -EINVAL;
 
-       if (mddev->pers)
-               return -EBUSY;
-       if (mddev->reshape_position != MaxSector)
+       if (mddev->pers) {
+               int err;
+               if (mddev->pers->reconfig == NULL)
+                       return -EBUSY;
+               err = mddev->pers->reconfig(mddev, n, -1);
+               if (err)
+                       return err;
+       } else {
                mddev->new_layout = n;
-       else
-               mddev->layout = n;
+               if (mddev->reshape_position == MaxSector)
+                       mddev->layout = n;
+       }
        return len;
 }
 static struct md_sysfs_entry md_layout =
@@ -2639,19 +2863,24 @@ chunk_size_show(mddev_t *mddev, char *page)
 static ssize_t
 chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
 {
-       /* can only set chunk_size if array is not yet active */
        char *e;
        unsigned long n = simple_strtoul(buf, &e, 10);
 
        if (!*buf || (*e && *e != '\n'))
                return -EINVAL;
 
-       if (mddev->pers)
-               return -EBUSY;
-       else if (mddev->reshape_position != MaxSector)
+       if (mddev->pers) {
+               int err;
+               if (mddev->pers->reconfig == NULL)
+                       return -EBUSY;
+               err = mddev->pers->reconfig(mddev, -1, n);
+               if (err)
+                       return err;
+       } else {
                mddev->new_chunk = n;
-       else
-               mddev->chunk_size = n;
+               if (mddev->reshape_position == MaxSector)
+                       mddev->chunk_size = n;
+       }
        return len;
 }
 static struct md_sysfs_entry md_chunk_size =
@@ -2660,6 +2889,8 @@ __ATTR(chunk_size, S_IRUGO|S_IWUSR, chunk_size_show, chunk_size_store);
 static ssize_t
 resync_start_show(mddev_t *mddev, char *page)
 {
+       if (mddev->recovery_cp == MaxSector)
+               return sprintf(page, "none\n");
        return sprintf(page, "%llu\n", (unsigned long long)mddev->recovery_cp);
 }
 
@@ -2757,7 +2988,7 @@ array_state_show(mddev_t *mddev, char *page)
        else {
                if (list_empty(&mddev->disks) &&
                    mddev->raid_disks == 0 &&
-                   mddev->size == 0)
+                   mddev->dev_sectors == 0)
                        st = clear;
                else
                        st = inactive;
@@ -2964,7 +3195,8 @@ __ATTR(bitmap_set_bits, S_IWUSR, null_show, bitmap_store);
 static ssize_t
 size_show(mddev_t *mddev, char *page)
 {
-       return sprintf(page, "%llu\n", (unsigned long long)mddev->size);
+       return sprintf(page, "%llu\n",
+               (unsigned long long)mddev->dev_sectors / 2);
 }
 
 static int update_size(mddev_t *mddev, sector_t num_sectors);
@@ -2976,20 +3208,18 @@ size_store(mddev_t *mddev, const char *buf, size_t len)
         * not increase it (except from 0).
         * If array is active, we can try an on-line resize
         */
-       char *e;
-       int err = 0;
-       unsigned long long size = simple_strtoull(buf, &e, 10);
-       if (!*buf || *buf == '\n' ||
-           (*e && *e != '\n'))
-               return -EINVAL;
+       sector_t sectors;
+       int err = strict_blocks_to_sectors(buf, &sectors);
 
+       if (err < 0)
+               return err;
        if (mddev->pers) {
-               err = update_size(mddev, size * 2);
+               err = update_size(mddev, sectors);
                md_update_sb(mddev, 1);
        } else {
-               if (mddev->size == 0 ||
-                   mddev->size > size)
-                       mddev->size = size;
+               if (mddev->dev_sectors == 0 ||
+                   mddev->dev_sectors > sectors)
+                       mddev->dev_sectors = sectors;
                else
                        err = -ENOSPC;
        }
@@ -3242,6 +3472,8 @@ static ssize_t
 sync_speed_show(mddev_t *mddev, char *page)
 {
        unsigned long resync, dt, db;
+       if (mddev->curr_resync == 0)
+               return sprintf(page, "none\n");
        resync = mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active);
        dt = (jiffies - mddev->resync_mark) / HZ;
        if (!dt) dt++;
@@ -3254,15 +3486,18 @@ static struct md_sysfs_entry md_sync_speed = __ATTR_RO(sync_speed);
 static ssize_t
 sync_completed_show(mddev_t *mddev, char *page)
 {
-       unsigned long max_blocks, resync;
+       unsigned long max_sectors, resync;
+
+       if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
+               return sprintf(page, "none\n");
 
        if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
-               max_blocks = mddev->resync_max_sectors;
+               max_sectors = mddev->resync_max_sectors;
        else
-               max_blocks = mddev->size << 1;
+               max_sectors = mddev->dev_sectors;
 
-       resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active));
-       return sprintf(page, "%lu / %lu\n", resync, max_blocks);
+       resync = mddev->curr_resync_completed;
+       return sprintf(page, "%lu / %lu\n", resync, max_sectors);
 }
 
 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
@@ -3422,6 +3657,57 @@ static struct md_sysfs_entry md_reshape_position =
 __ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
        reshape_position_store);
 
+static ssize_t
+array_size_show(mddev_t *mddev, char *page)
+{
+       if (mddev->external_size)
+               return sprintf(page, "%llu\n",
+                              (unsigned long long)mddev->array_sectors/2);
+       else
+               return sprintf(page, "default\n");
+}
+
+static ssize_t
+array_size_store(mddev_t *mddev, const char *buf, size_t len)
+{
+       sector_t sectors;
+
+       if (strncmp(buf, "default", 7) == 0) {
+               if (mddev->pers)
+                       sectors = mddev->pers->size(mddev, 0, 0);
+               else
+                       sectors = mddev->array_sectors;
+
+               mddev->external_size = 0;
+       } else {
+               if (strict_blocks_to_sectors(buf, &sectors) < 0)
+                       return -EINVAL;
+               if (mddev->pers && mddev->pers->size(mddev, 0, 0) < sectors)
+                       return -EINVAL;
+
+               mddev->external_size = 1;
+       }
+
+       mddev->array_sectors = sectors;
+       set_capacity(mddev->gendisk, mddev->array_sectors);
+       if (mddev->pers) {
+               struct block_device *bdev = bdget_disk(mddev->gendisk, 0);
+
+               if (bdev) {
+                       mutex_lock(&bdev->bd_inode->i_mutex);
+                       i_size_write(bdev->bd_inode,
+                                    (loff_t)mddev->array_sectors << 9);
+                       mutex_unlock(&bdev->bd_inode->i_mutex);
+                       bdput(bdev);
+               }
+       }
+
+       return len;
+}
+
+static struct md_sysfs_entry md_array_size =
+__ATTR(array_size, S_IRUGO|S_IWUSR, array_size_show,
+       array_size_store);
 
 static struct attribute *md_default_attrs[] = {
        &md_level.attr,
@@ -3435,6 +3721,7 @@ static struct attribute *md_default_attrs[] = {
        &md_safe_delay.attr,
        &md_array_state.attr,
        &md_reshape_position.attr,
+       &md_array_size.attr,
        NULL,
 };
 
@@ -3528,6 +3815,21 @@ static struct kobj_type md_ktype = {
 
 int mdp_major = 0;
 
+static void mddev_delayed_delete(struct work_struct *ws)
+{
+       mddev_t *mddev = container_of(ws, mddev_t, del_work);
+
+       if (mddev->private == &md_redundancy_group) {
+               sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
+               if (mddev->sysfs_action)
+                       sysfs_put(mddev->sysfs_action);
+               mddev->sysfs_action = NULL;
+               mddev->private = NULL;
+       }
+       kobject_del(&mddev->kobj);
+       kobject_put(&mddev->kobj);
+}
+
 static int md_alloc(dev_t dev, char *name)
 {
        static DEFINE_MUTEX(disks_mutex);
@@ -3578,10 +3880,12 @@ static int md_alloc(dev_t dev, char *name)
                mddev_put(mddev);
                return -ENOMEM;
        }
+       mddev->queue->queuedata = mddev;
+
        /* Can be unlocked because the queue is new: no concurrency */
        queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, mddev->queue);
 
-       blk_queue_make_request(mddev->queue, md_fail_request);
+       blk_queue_make_request(mddev->queue, md_make_request);
 
        disk = alloc_disk(1 << shift);
        if (!disk) {
@@ -3707,13 +4011,13 @@ static int do_md_run(mddev_t * mddev)
                list_for_each_entry(rdev, &mddev->disks, same_set) {
                        if (test_bit(Faulty, &rdev->flags))
                                continue;
-                       if (rdev->size < chunk_size / 1024) {
+                       if (rdev->sectors < chunk_size / 512) {
                                printk(KERN_WARNING
                                        "md: Dev %s smaller than chunk_size:"
-                                       " %lluk < %dk\n",
+                                       " %llu < %d\n",
                                        bdevname(rdev->bdev,b),
-                                       (unsigned long long)rdev->size,
-                                       chunk_size / 1024);
+                                       (unsigned long long)rdev->sectors,
+                                       chunk_size / 512);
                                return -EINVAL;
                        }
                }
@@ -3737,11 +4041,11 @@ static int do_md_run(mddev_t * mddev)
 
                /* perform some consistency tests on the device.
                 * We don't want the data to overlap the metadata,
-                * Internal Bitmap issues has handled elsewhere.
+                * Internal Bitmap issues have been handled elsewhere.
                 */
                if (rdev->data_offset < rdev->sb_start) {
-                       if (mddev->size &&
-                           rdev->data_offset + mddev->size*2
+                       if (mddev->dev_sectors &&
+                           rdev->data_offset + mddev->dev_sectors
                            > rdev->sb_start) {
                                printk("md: %s: data overlaps metadata\n",
                                       mdname(mddev));
@@ -3777,9 +4081,16 @@ static int do_md_run(mddev_t * mddev)
        }
        mddev->pers = pers;
        spin_unlock(&pers_lock);
-       mddev->level = pers->level;
+       if (mddev->level != pers->level) {
+               mddev->level = pers->level;
+               mddev->new_level = pers->level;
+       }
        strlcpy(mddev->clevel, pers->name, sizeof(mddev->clevel));
 
+       if (pers->level >= 4 && pers->level <= 6)
+               /* Cannot support integrity (yet) */
+               blk_integrity_unregister(mddev->gendisk);
+
        if (mddev->reshape_position != MaxSector &&
            pers->start_reshape == NULL) {
                /* This personality cannot handle reshaping... */
@@ -3819,7 +4130,9 @@ static int do_md_run(mddev_t * mddev)
        }
 
        mddev->recovery = 0;
-       mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
+       /* may be over-ridden by personality */
+       mddev->resync_max_sectors = mddev->dev_sectors;
+
        mddev->barriers_work = 1;
        mddev->ok_start_degraded = start_dirty_degraded;
 
@@ -3829,7 +4142,17 @@ static int do_md_run(mddev_t * mddev)
        err = mddev->pers->run(mddev);
        if (err)
                printk(KERN_ERR "md: pers->run() failed ...\n");
-       else if (mddev->pers->sync_request) {
+       else if (mddev->pers->size(mddev, 0, 0) < mddev->array_sectors) {
+               WARN_ONCE(!mddev->external_size, "%s: default size too small,"
+                         " but 'external_size' not in effect?\n", __func__);
+               printk(KERN_ERR
+                      "md: invalid array_size %llu > default size %llu\n",
+                      (unsigned long long)mddev->array_sectors / 2,
+                      (unsigned long long)mddev->pers->size(mddev, 0, 0) / 2);
+               err = -EINVAL;
+               mddev->pers->stop(mddev);
+       }
+       if (err == 0 && mddev->pers->sync_request) {
                err = bitmap_create(mddev);
                if (err) {
                        printk(KERN_ERR "%s: failed to create bitmap (%d)\n",
@@ -3875,16 +4198,6 @@ static int do_md_run(mddev_t * mddev)
 
        set_capacity(disk, mddev->array_sectors);
 
-       /* If we call blk_queue_make_request here, it will
-        * re-initialise max_sectors etc which may have been
-        * refined inside -> run.  So just set the bits we need to set.
-        * Most initialisation happended when we called
-        * blk_queue_make_request(..., md_fail_request)
-        * earlier.
-        */
-       mddev->queue->queuedata = mddev;
-       mddev->queue->make_request_fn = mddev->pers->make_request;
-
        /* If there is a partially-recovered drive we need to
         * start recovery here.  If we leave it to md_check_recovery,
         * it will remove the drives and not do the right thing
@@ -4014,18 +4327,14 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                        md_super_wait(mddev);
                        if (mddev->ro)
                                set_disk_ro(disk, 0);
-                       blk_queue_make_request(mddev->queue, md_fail_request);
+
                        mddev->pers->stop(mddev);
                        mddev->queue->merge_bvec_fn = NULL;
                        mddev->queue->unplug_fn = NULL;
                        mddev->queue->backing_dev_info.congested_fn = NULL;
-                       if (mddev->pers->sync_request) {
-                               sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
-                               if (mddev->sysfs_action)
-                                       sysfs_put(mddev->sysfs_action);
-                               mddev->sysfs_action = NULL;
-                       }
                        module_put(mddev->pers->owner);
+                       if (mddev->pers->sync_request)
+                               mddev->private = &md_redundancy_group;
                        mddev->pers = NULL;
                        /* tell userspace to handle 'inactive' */
                        sysfs_notify_dirent(mddev->sysfs_state);
@@ -4075,7 +4384,8 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                export_array(mddev);
 
                mddev->array_sectors = 0;
-               mddev->size = 0;
+               mddev->external_size = 0;
+               mddev->dev_sectors = 0;
                mddev->raid_disks = 0;
                mddev->recovery_cp = 0;
                mddev->resync_min = 0;
@@ -4115,6 +4425,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                printk(KERN_INFO "md: %s switched to read-only mode.\n",
                        mdname(mddev));
        err = 0;
+       blk_integrity_unregister(disk);
        md_new_event(mddev);
        sysfs_notify_dirent(mddev->sysfs_state);
 out:
@@ -4280,8 +4591,8 @@ static int get_array_info(mddev_t * mddev, void __user * arg)
        info.patch_version = MD_PATCHLEVEL_VERSION;
        info.ctime         = mddev->ctime;
        info.level         = mddev->level;
-       info.size          = mddev->size;
-       if (info.size != mddev->size) /* overflow */
+       info.size          = mddev->dev_sectors / 2;
+       if (info.size != mddev->dev_sectors / 2) /* overflow */
                info.size = -1;
        info.nr_disks      = nr;
        info.raid_disks    = mddev->raid_disks;
@@ -4460,6 +4771,8 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
                clear_bit(In_sync, &rdev->flags); /* just to be sure */
                if (info->state & (1<<MD_DISK_WRITEMOSTLY))
                        set_bit(WriteMostly, &rdev->flags);
+               else
+                       clear_bit(WriteMostly, &rdev->flags);
 
                rdev->raid_disk = -1;
                err = bind_rdev_to_array(rdev, mddev);
@@ -4523,7 +4836,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
                        rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
                } else 
                        rdev->sb_start = calc_dev_sboffset(rdev->bdev);
-               rdev->size = calc_num_sectors(rdev, mddev->chunk_size) / 2;
+               rdev->sectors = calc_num_sectors(rdev, mddev->chunk_size);
 
                err = bind_rdev_to_array(rdev, mddev);
                if (err) {
@@ -4593,7 +4906,7 @@ static int hot_add_disk(mddev_t * mddev, dev_t dev)
        else
                rdev->sb_start = rdev->bdev->bd_inode->i_size / 512;
 
-       rdev->size = calc_num_sectors(rdev, mddev->chunk_size) / 2;
+       rdev->sectors = calc_num_sectors(rdev, mddev->chunk_size);
 
        if (test_bit(Faulty, &rdev->flags)) {
                printk(KERN_WARNING 
@@ -4614,13 +4927,6 @@ static int hot_add_disk(mddev_t * mddev, dev_t dev)
         * noticed in interrupt contexts ...
         */
 
-       if (rdev->desc_nr == mddev->max_disks) {
-               printk(KERN_WARNING "%s: can not hot-add to full array!\n",
-                       mdname(mddev));
-               err = -EBUSY;
-               goto abort_unbind_export;
-       }
-
        rdev->raid_disk = -1;
 
        md_update_sb(mddev, 1);
@@ -4634,9 +4940,6 @@ static int hot_add_disk(mddev_t * mddev, dev_t dev)
        md_new_event(mddev);
        return 0;
 
-abort_unbind_export:
-       unbind_rdev_from_array(rdev);
-
 abort_export:
        export_rdev(rdev);
        return err;
@@ -4739,7 +5042,7 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
 
        mddev->level         = info->level;
        mddev->clevel[0]     = 0;
-       mddev->size          = info->size;
+       mddev->dev_sectors   = 2 * (sector_t)info->size;
        mddev->raid_disks    = info->raid_disks;
        /* don't set md_minor, it is determined by which /dev/md* was
         * openned
@@ -4778,6 +5081,17 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
        return 0;
 }
 
+void md_set_array_sectors(mddev_t *mddev, sector_t array_sectors)
+{
+       WARN(!mddev_is_locked(mddev), "%s: unlocked mddev!\n", __func__);
+
+       if (mddev->external_size)
+               return;
+
+       mddev->array_sectors = array_sectors;
+}
+EXPORT_SYMBOL(md_set_array_sectors);
+
 static int update_size(mddev_t *mddev, sector_t num_sectors)
 {
        mdk_rdev_t *rdev;
@@ -4804,8 +5118,7 @@ static int update_size(mddev_t *mddev, sector_t num_sectors)
                 */
                return -EBUSY;
        list_for_each_entry(rdev, &mddev->disks, same_set) {
-               sector_t avail;
-               avail = rdev->size * 2;
+               sector_t avail = rdev->sectors;
 
                if (fit && (num_sectors == 0 || num_sectors > avail))
                        num_sectors = avail;
@@ -4877,12 +5190,18 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
                )
                return -EINVAL;
        /* Check there is only one change */
-       if (info->size >= 0 && mddev->size != info->size) cnt++;
-       if (mddev->raid_disks != info->raid_disks) cnt++;
-       if (mddev->layout != info->layout) cnt++;
-       if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT)) cnt++;
-       if (cnt == 0) return 0;
-       if (cnt > 1) return -EINVAL;
+       if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
+               cnt++;
+       if (mddev->raid_disks != info->raid_disks)
+               cnt++;
+       if (mddev->layout != info->layout)
+               cnt++;
+       if ((state ^ info->state) & (1<<MD_SB_BITMAP_PRESENT))
+               cnt++;
+       if (cnt == 0)
+               return 0;
+       if (cnt > 1)
+               return -EINVAL;
 
        if (mddev->layout != info->layout) {
                /* Change layout
@@ -4894,7 +5213,7 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
                else
                        return mddev->pers->reconfig(mddev, info->layout, -1);
        }
-       if (info->size >= 0 && mddev->size != info->size)
+       if (info->size >= 0 && mddev->dev_sectors / 2 != info->size)
                rv = update_size(mddev, (sector_t)info->size * 2);
 
        if (mddev->raid_disks    != info->raid_disks)
@@ -5321,6 +5640,8 @@ mdk_thread_t *md_register_thread(void (*run) (mddev_t *), mddev_t *mddev,
 
 void md_unregister_thread(mdk_thread_t *thread)
 {
+       if (!thread)
+               return;
        dprintk("interrupting MD-thread pid %d\n", task_pid_nr(thread->tsk));
 
        kthread_stop(thread->tsk);
@@ -5384,37 +5705,38 @@ static void status_unused(struct seq_file *seq)
 
 static void status_resync(struct seq_file *seq, mddev_t * mddev)
 {
-       sector_t max_blocks, resync, res;
-       unsigned long dt, db, rt;
+       sector_t max_sectors, resync, res;
+       unsigned long dt, db;
+       sector_t rt;
        int scale;
        unsigned int per_milli;
 
-       resync = (mddev->curr_resync - atomic_read(&mddev->recovery_active))/2;
+       resync = mddev->curr_resync - atomic_read(&mddev->recovery_active);
 
        if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
-               max_blocks = mddev->resync_max_sectors >> 1;
+               max_sectors = mddev->resync_max_sectors;
        else
-               max_blocks = mddev->size;
+               max_sectors = mddev->dev_sectors;
 
        /*
         * Should not happen.
         */
-       if (!max_blocks) {
+       if (!max_sectors) {
                MD_BUG();
                return;
        }
        /* Pick 'scale' such that (resync>>scale)*1000 will fit
-        * in a sector_t, and (max_blocks>>scale) will fit in a
+        * in a sector_t, and (max_sectors>>scale) will fit in a
         * u32, as those are the requirements for sector_div.
         * Thus 'scale' must be at least 10
         */
        scale = 10;
        if (sizeof(sector_t) > sizeof(unsigned long)) {
-               while ( max_blocks/2 > (1ULL<<(scale+32)))
+               while ( max_sectors/2 > (1ULL<<(scale+32)))
                        scale++;
        }
        res = (resync>>scale)*1000;
-       sector_div(res, (u32)((max_blocks>>scale)+1));
+       sector_div(res, (u32)((max_sectors>>scale)+1));
 
        per_milli = res;
        {
@@ -5435,25 +5757,35 @@ static void status_resync(struct seq_file *seq, mddev_t * mddev)
                     (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ?
                      "resync" : "recovery"))),
                   per_milli/10, per_milli % 10,
-                  (unsigned long long) resync,
-                  (unsigned long long) max_blocks);
+                  (unsigned long long) resync/2,
+                  (unsigned long long) max_sectors/2);
 
        /*
-        * We do not want to overflow, so the order of operands and
-        * the * 100 / 100 trick are important. We do a +1 to be
-        * safe against division by zero. We only estimate anyway.
-        *
         * dt: time from mark until now
         * db: blocks written from mark until now
         * rt: remaining time
+        *
+        * rt is a sector_t, so could be 32bit or 64bit.
+        * So we divide before multiply in case it is 32bit and close
+        * to the limit.
+        * We scale the divisor (db) by 32 to avoid loosing precision
+        * near the end of resync when the number of remaining sectors
+        * is close to 'db'.
+        * We then divide rt by 32 after multiplying by db to compensate.
+        * The '+1' avoids division by zero if db is very small.
         */
        dt = ((jiffies - mddev->resync_mark) / HZ);
        if (!dt) dt++;
        db = (mddev->curr_mark_cnt - atomic_read(&mddev->recovery_active))
                - mddev->resync_mark_cnt;
-       rt = (dt * ((unsigned long)(max_blocks-resync) / (db/2/100+1)))/100;
 
-       seq_printf(seq, " finish=%lu.%lumin", rt / 60, (rt % 60)/6);
+       rt = max_sectors - resync;    /* number of remaining sectors */
+       sector_div(rt, db/32+1);
+       rt *= dt;
+       rt >>= 5;
+
+       seq_printf(seq, " finish=%lu.%lumin", (unsigned long)rt / 60,
+                  ((unsigned long)rt % 60)/6);
 
        seq_printf(seq, " speed=%ldK/sec", db/2/dt);
 }
@@ -5527,7 +5859,7 @@ struct mdstat_info {
 static int md_seq_show(struct seq_file *seq, void *v)
 {
        mddev_t *mddev = v;
-       sector_t size;
+       sector_t sectors;
        mdk_rdev_t *rdev;
        struct mdstat_info *mi = seq->private;
        struct bitmap *bitmap;
@@ -5563,7 +5895,7 @@ static int md_seq_show(struct seq_file *seq, void *v)
                        seq_printf(seq, " %s", mddev->pers->name);
                }
 
-               size = 0;
+               sectors = 0;
                list_for_each_entry(rdev, &mddev->disks, same_set) {
                        char b[BDEVNAME_SIZE];
                        seq_printf(seq, " %s[%d]",
@@ -5575,7 +5907,7 @@ static int md_seq_show(struct seq_file *seq, void *v)
                                continue;
                        } else if (rdev->raid_disk < 0)
                                seq_printf(seq, "(S)"); /* spare */
-                       size += rdev->size;
+                       sectors += rdev->sectors;
                }
 
                if (!list_empty(&mddev->disks)) {
@@ -5585,7 +5917,7 @@ static int md_seq_show(struct seq_file *seq, void *v)
                                           mddev->array_sectors / 2);
                        else
                                seq_printf(seq, "\n      %llu blocks",
-                                          (unsigned long long)size);
+                                          (unsigned long long)sectors / 2);
                }
                if (mddev->persistent) {
                        if (mddev->major_version != 0 ||
@@ -5644,7 +5976,7 @@ static int md_seq_show(struct seq_file *seq, void *v)
        return 0;
 }
 
-static struct seq_operations md_seq_ops = {
+static const struct seq_operations md_seq_ops = {
        .start  = md_seq_start,
        .next   = md_seq_next,
        .stop   = md_seq_stop,
@@ -5712,19 +6044,19 @@ int unregister_md_personality(struct mdk_personality *p)
        return 0;
 }
 
-static int is_mddev_idle(mddev_t *mddev)
+static int is_mddev_idle(mddev_t *mddev, int init)
 {
        mdk_rdev_t * rdev;
        int idle;
-       long curr_events;
+       int curr_events;
 
        idle = 1;
        rcu_read_lock();
        rdev_for_each_rcu(rdev, mddev) {
                struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
-               curr_events = part_stat_read(&disk->part0, sectors[0]) +
-                               part_stat_read(&disk->part0, sectors[1]) -
-                               atomic_read(&disk->sync_io);
+               curr_events = (int)part_stat_read(&disk->part0, sectors[0]) +
+                             (int)part_stat_read(&disk->part0, sectors[1]) -
+                             atomic_read(&disk->sync_io);
                /* sync IO will cause sync_io to increase before the disk_stats
                 * as sync_io is counted when a request starts, and
                 * disk_stats is counted when it completes.
@@ -5747,7 +6079,7 @@ static int is_mddev_idle(mddev_t *mddev)
                 * always make curr_events less than last_events.
                 *
                 */
-               if (curr_events - rdev->last_events > 4096) {
+               if (init || curr_events - rdev->last_events > 64) {
                        rdev->last_events = curr_events;
                        idle = 0;
                }
@@ -5970,10 +6302,10 @@ void md_do_sync(mddev_t *mddev)
                        j = mddev->recovery_cp;
 
        } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
-               max_sectors = mddev->size << 1;
+               max_sectors = mddev->dev_sectors;
        else {
                /* recovery follows the physical size of devices */
-               max_sectors = mddev->size << 1;
+               max_sectors = mddev->dev_sectors;
                j = MaxSector;
                list_for_each_entry(rdev, &mddev->disks, same_set)
                        if (rdev->raid_disk >= 0 &&
@@ -5990,7 +6322,7 @@ void md_do_sync(mddev_t *mddev)
               "(but not more than %d KB/sec) for %s.\n",
               speed_max(mddev), desc);
 
-       is_mddev_idle(mddev); /* this also initializes IO event counters */
+       is_mddev_idle(mddev, 1); /* this initializes IO event counters */
 
        io_sectors = 0;
        for (m = 0; m < SYNC_MARKS; m++) {
@@ -6022,14 +6354,31 @@ void md_do_sync(mddev_t *mddev)
                sector_t sectors;
 
                skipped = 0;
-               if (j >= mddev->resync_max) {
+
+               if ((mddev->curr_resync > mddev->curr_resync_completed &&
+                    (mddev->curr_resync - mddev->curr_resync_completed)
+                   > (max_sectors >> 4)) ||
+                   (j - mddev->curr_resync_completed)*2
+                   >= mddev->resync_max - mddev->curr_resync_completed
+                       ) {
+                       /* time to update curr_resync_completed */
+                       blk_unplug(mddev->queue);
+                       wait_event(mddev->recovery_wait,
+                                  atomic_read(&mddev->recovery_active) == 0);
+                       mddev->curr_resync_completed =
+                               mddev->curr_resync;
+                       set_bit(MD_CHANGE_CLEAN, &mddev->flags);
                        sysfs_notify(&mddev->kobj, NULL, "sync_completed");
+               }
+
+               if (j >= mddev->resync_max)
                        wait_event(mddev->recovery_wait,
                                   mddev->resync_max > j
                                   || kthread_should_stop());
-               }
+
                if (kthread_should_stop())
                        goto interrupted;
+
                sectors = mddev->pers->sync_request(mddev, j, &skipped,
                                                  currspeed < speed_min(mddev));
                if (sectors == 0) {
@@ -6092,7 +6441,7 @@ void md_do_sync(mddev_t *mddev)
 
                if (currspeed > speed_min(mddev)) {
                        if ((currspeed > speed_max(mddev)) ||
-                                       !is_mddev_idle(mddev)) {
+                                       !is_mddev_idle(mddev, 0)) {
                                msleep(500);
                                goto repeat;
                        }
@@ -6137,6 +6486,7 @@ void md_do_sync(mddev_t *mddev)
 
  skip:
        mddev->curr_resync = 0;
+       mddev->curr_resync_completed = 0;
        mddev->resync_min = 0;
        mddev->resync_max = MaxSector;
        sysfs_notify(&mddev->kobj, NULL, "sync_completed");
@@ -6163,6 +6513,8 @@ static int remove_and_add_spares(mddev_t *mddev)
        mdk_rdev_t *rdev;
        int spares = 0;
 
+       mddev->curr_resync_completed = 0;
+
        list_for_each_entry(rdev, &mddev->disks, same_set)
                if (rdev->raid_disk >= 0 &&
                    !test_bit(Blocked, &rdev->flags) &&
@@ -6317,6 +6669,9 @@ void md_check_recovery(mddev_t *mddev)
                                        sysfs_notify(&mddev->kobj, NULL,
                                                     "degraded");
                        }
+                       if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
+                           mddev->pers->finish_reshape)
+                               mddev->pers->finish_reshape(mddev);
                        md_update_sb(mddev, 1);
 
                        /* if array is no-longer degraded, then any saved_raid_disk
@@ -6460,13 +6815,13 @@ static void md_geninit(void)
 
 static int __init md_init(void)
 {
-       if (register_blkdev(MAJOR_NR, "md"))
+       if (register_blkdev(MD_MAJOR, "md"))
                return -1;
        if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
-               unregister_blkdev(MAJOR_NR, "md");
+               unregister_blkdev(MD_MAJOR, "md");
                return -1;
        }
-       blk_register_region(MKDEV(MAJOR_NR, 0), 1UL<<MINORBITS, THIS_MODULE,
+       blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
                            md_probe, NULL, NULL);
        blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
                            md_probe, NULL, NULL);
@@ -6552,10 +6907,10 @@ static __exit void md_exit(void)
        mddev_t *mddev;
        struct list_head *tmp;
 
-       blk_unregister_region(MKDEV(MAJOR_NR,0), 1U << MINORBITS);
+       blk_unregister_region(MKDEV(MD_MAJOR,0), 1U << MINORBITS);
        blk_unregister_region(MKDEV(mdp_major,0), 1U << MINORBITS);
 
-       unregister_blkdev(MAJOR_NR,"md");
+       unregister_blkdev(MD_MAJOR,"md");
        unregister_blkdev(mdp_major, "mdp");
        unregister_reboot_notifier(&md_notifier);
        unregister_sysctl_table(raid_table_header);