Make sure all changes to md/dev-XX/state are notified
[pandora-kernel.git] / drivers / md / md.c
index bb3e4b1..dc99d95 100644 (file)
@@ -74,6 +74,8 @@ static DEFINE_SPINLOCK(pers_lock);
 
 static void md_print_devices(void);
 
+static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
+
 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
 
 /*
@@ -167,7 +169,6 @@ void md_new_event(mddev_t *mddev)
 {
        atomic_inc(&md_event_count);
        wake_up(&md_event_waiters);
-       sysfs_notify(&mddev->kobj, NULL, "sync_action");
 }
 EXPORT_SYMBOL_GPL(md_new_event);
 
@@ -274,8 +275,11 @@ static mddev_t * mddev_find(dev_t unit)
        atomic_set(&new->active, 1);
        spin_lock_init(&new->write_lock);
        init_waitqueue_head(&new->sb_wait);
+       init_waitqueue_head(&new->recovery_wait);
        new->reshape_position = MaxSector;
+       new->resync_min = 0;
        new->resync_max = MaxSector;
+       new->level = LEVEL_NONE;
 
        new->queue = blk_alloc_queue(GFP_KERNEL);
        if (!new->queue) {
@@ -1369,6 +1373,11 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
                MD_BUG();
                return -EINVAL;
        }
+
+       /* prevent duplicates */
+       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)) {
                if (mddev->pers) {
@@ -1652,6 +1661,8 @@ static void md_update_sb(mddev_t * mddev, int force_change)
        int sync_req;
        int nospares = 0;
 
+       if (mddev->external)
+               return;
 repeat:
        spin_lock_irq(&mddev->write_lock);
 
@@ -1820,6 +1831,10 @@ state_show(mdk_rdev_t *rdev, char *page)
                len += sprintf(page+len, "%swrite_mostly",sep);
                sep = ",";
        }
+       if (test_bit(Blocked, &rdev->flags)) {
+               len += sprintf(page+len, "%sblocked", sep);
+               sep = ",";
+       }
        if (!test_bit(Faulty, &rdev->flags) &&
            !test_bit(In_sync, &rdev->flags)) {
                len += sprintf(page+len, "%sspare", sep);
@@ -1836,6 +1851,8 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
         *  remove  - disconnects the device
         *  writemostly - sets write_mostly
         *  -writemostly - clears write_mostly
+        *  blocked - sets the Blocked flag
+        *  -blocked - clears the Blocked flag
         */
        int err = -EINVAL;
        if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
@@ -1857,8 +1874,20 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                err = 0;
        } else if (cmd_match(buf, "-writemostly")) {
                clear_bit(WriteMostly, &rdev->flags);
+               err = 0;
+       } else if (cmd_match(buf, "blocked")) {
+               set_bit(Blocked, &rdev->flags);
+               err = 0;
+       } else if (cmd_match(buf, "-blocked")) {
+               clear_bit(Blocked, &rdev->flags);
+               wake_up(&rdev->blocked_wait);
+               set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
+               md_wakeup_thread(rdev->mddev->thread);
+
                err = 0;
        }
+       if (!err)
+               sysfs_notify(&rdev->kobj, NULL, "state");
        return err ? err : len;
 }
 static struct rdev_sysfs_entry rdev_state =
@@ -1904,7 +1933,7 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                slot = -1;
        else if (e==buf || (*e && *e!= '\n'))
                return -EINVAL;
-       if (rdev->mddev->pers) {
+       if (rdev->mddev->pers && slot == -1) {
                /* Setting 'slot' on an active array requires also
                 * updating the 'rd%d' link, and communicating
                 * with the personality with ->hot_*_disk.
@@ -1912,8 +1941,6 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                 * failed/spare devices.  This normally happens automatically,
                 * but not when the metadata is externally managed.
                 */
-               if (slot != -1)
-                       return -EBUSY;
                if (rdev->raid_disk == -1)
                        return -EEXIST;
                /* personality does all needed checks */
@@ -1927,6 +1954,43 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                sysfs_remove_link(&rdev->mddev->kobj, nm);
                set_bit(MD_RECOVERY_NEEDED, &rdev->mddev->recovery);
                md_wakeup_thread(rdev->mddev->thread);
+       } else if (rdev->mddev->pers) {
+               mdk_rdev_t *rdev2;
+               struct list_head *tmp;
+               /* Activating a spare .. or possibly reactivating
+                * if we every get bitmaps working here.
+                */
+
+               if (rdev->raid_disk != -1)
+                       return -EBUSY;
+
+               if (rdev->mddev->pers->hot_add_disk == NULL)
+                       return -EINVAL;
+
+               rdev_for_each(rdev2, tmp, rdev->mddev)
+                       if (rdev2->raid_disk == slot)
+                               return -EEXIST;
+
+               rdev->raid_disk = slot;
+               if (test_bit(In_sync, &rdev->flags))
+                       rdev->saved_raid_disk = slot;
+               else
+                       rdev->saved_raid_disk = -1;
+               err = rdev->mddev->pers->
+                       hot_add_disk(rdev->mddev, rdev);
+               if (err) {
+                       rdev->raid_disk = -1;
+                       return err;
+               } else
+                       sysfs_notify(&rdev->kobj, NULL, "state");
+               sprintf(nm, "rd%d", rdev->raid_disk);
+               if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
+                       printk(KERN_WARNING
+                              "md: cannot register "
+                              "%s for %s\n",
+                              nm, mdname(rdev->mddev));
+
+               /* don't wakeup anyone, leave that to userspace. */
        } else {
                if (slot >= rdev->mddev->raid_disks)
                        return -ENOSPC;
@@ -1935,6 +1999,7 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                clear_bit(Faulty, &rdev->flags);
                clear_bit(WriteMostly, &rdev->flags);
                set_bit(In_sync, &rdev->flags);
+               sysfs_notify(&rdev->kobj, NULL, "state");
        }
        return len;
 }
@@ -1956,7 +2021,7 @@ offset_store(mdk_rdev_t *rdev, const char *buf, size_t len)
        unsigned long long offset = simple_strtoull(buf, &e, 10);
        if (e==buf || (*e && *e != '\n'))
                return -EINVAL;
-       if (rdev->mddev->pers)
+       if (rdev->mddev->pers && rdev->raid_disk >= 0)
                return -EBUSY;
        if (rdev->size && rdev->mddev->external)
                /* Must set offset before size, so overlap checks
@@ -1995,7 +2060,7 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
 
        if (e==buf || (*e && *e != '\n'))
                return -EINVAL;
-       if (my_mddev->pers)
+       if (my_mddev->pers && rdev->raid_disk >= 0)
                return -EBUSY;
        rdev->size = size;
        if (size > oldsize && rdev->mddev->external) {
@@ -2097,7 +2162,7 @@ rdev_attr_store(struct kobject *kobj, struct attribute *attr,
                        rv = -EBUSY;
                else
                        rv = entry->store(rdev, page, length);
-               mddev_unlock(rdev->mddev);
+               mddev_unlock(mddev);
        }
        return rv;
 }
@@ -2186,7 +2251,9 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
                        goto abort_free;
                }
        }
+
        INIT_LIST_HEAD(&rdev->same_set);
+       init_waitqueue_head(&rdev->blocked_wait);
 
        return rdev;
 
@@ -2457,7 +2524,6 @@ resync_start_show(mddev_t *mddev, char *page)
 static ssize_t
 resync_start_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 long n = simple_strtoull(buf, &e, 10);
 
@@ -2591,15 +2657,20 @@ array_state_store(mddev_t *mddev, const char *buf, size_t len)
                        err = do_md_stop(mddev, 1);
                else {
                        mddev->ro = 1;
+                       set_disk_ro(mddev->gendisk, 1);
                        err = do_md_run(mddev);
                }
                break;
        case read_auto:
-               /* stopping an active array */
                if (mddev->pers) {
-                       err = do_md_stop(mddev, 1);
-                       if (err == 0)
-                               mddev->ro = 2; /* FIXME mark devices writable */
+                       if (mddev->ro != 1)
+                               err = do_md_stop(mddev, 1);
+                       else
+                               err = restart_array(mddev);
+                       if (err == 0) {
+                               mddev->ro = 2;
+                               set_disk_ro(mddev->gendisk, 0);
+                       }
                } else {
                        mddev->ro = 2;
                        err = do_md_run(mddev);
@@ -2612,6 +2683,8 @@ array_state_store(mddev_t *mddev, const char *buf, size_t len)
                        if (atomic_read(&mddev->writes_pending) == 0) {
                                if (mddev->in_sync == 0) {
                                        mddev->in_sync = 1;
+                                       if (mddev->safemode == 1)
+                                               mddev->safemode = 0;
                                        if (mddev->persistent)
                                                set_bit(MD_CHANGE_CLEAN,
                                                        &mddev->flags);
@@ -2635,6 +2708,7 @@ array_state_store(mddev_t *mddev, const char *buf, size_t len)
                        err = 0;
                } else {
                        mddev->ro = 0;
+                       set_disk_ro(mddev->gendisk, 0);
                        err = do_md_run(mddev);
                }
                break;
@@ -2645,8 +2719,10 @@ array_state_store(mddev_t *mddev, const char *buf, size_t len)
        }
        if (err)
                return err;
-       else
+       else {
+               sysfs_notify(&mddev->kobj, NULL, "array_state");
                return len;
+       }
 }
 static struct md_sysfs_entry md_array_state =
 __ATTR(array_state, S_IRUGO|S_IWUSR, array_state_show, array_state_store);
@@ -2863,7 +2939,7 @@ action_show(mddev_t *mddev, char *page)
                                type = "check";
                        else
                                type = "repair";
-               } else
+               } else if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
                        type = "recover";
        }
        return sprintf(page, "%s\n", type);
@@ -2885,15 +2961,19 @@ action_store(mddev_t *mddev, const char *page, size_t len)
        } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
                   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
                return -EBUSY;
-       else if (cmd_match(page, "resync") || cmd_match(page, "recover"))
+       else if (cmd_match(page, "resync"))
+               set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+       else if (cmd_match(page, "recover")) {
+               set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-       else if (cmd_match(page, "reshape")) {
+       else if (cmd_match(page, "reshape")) {
                int err;
                if (mddev->pers->start_reshape == NULL)
                        return -EINVAL;
                err = mddev->pers->start_reshape(mddev);
                if (err)
                        return err;
+               sysfs_notify(&mddev->kobj, NULL, "degraded");
        } else {
                if (cmd_match(page, "check"))
                        set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
@@ -2904,6 +2984,7 @@ action_store(mddev_t *mddev, const char *page, size_t len)
        }
        set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
        md_wakeup_thread(mddev->thread);
+       sysfs_notify(&mddev->kobj, NULL, "sync_action");
        return len;
 }
 
@@ -2979,6 +3060,36 @@ degraded_show(mddev_t *mddev, char *page)
 }
 static struct md_sysfs_entry md_degraded = __ATTR_RO(degraded);
 
+static ssize_t
+sync_force_parallel_show(mddev_t *mddev, char *page)
+{
+       return sprintf(page, "%d\n", mddev->parallel_resync);
+}
+
+static ssize_t
+sync_force_parallel_store(mddev_t *mddev, const char *buf, size_t len)
+{
+       long n;
+
+       if (strict_strtol(buf, 10, &n))
+               return -EINVAL;
+
+       if (n != 0 && n != 1)
+               return -EINVAL;
+
+       mddev->parallel_resync = n;
+
+       if (mddev->sync_thread)
+               wake_up(&resync_wait);
+
+       return len;
+}
+
+/* force parallel resync, even with shared block devices */
+static struct md_sysfs_entry md_sync_force_parallel =
+__ATTR(sync_force_parallel, S_IRUGO|S_IWUSR,
+       sync_force_parallel_show, sync_force_parallel_store);
+
 static ssize_t
 sync_speed_show(mddev_t *mddev, char *page)
 {
@@ -3008,6 +3119,36 @@ sync_completed_show(mddev_t *mddev, char *page)
 
 static struct md_sysfs_entry md_sync_completed = __ATTR_RO(sync_completed);
 
+static ssize_t
+min_sync_show(mddev_t *mddev, char *page)
+{
+       return sprintf(page, "%llu\n",
+                      (unsigned long long)mddev->resync_min);
+}
+static ssize_t
+min_sync_store(mddev_t *mddev, const char *buf, size_t len)
+{
+       unsigned long long min;
+       if (strict_strtoull(buf, 10, &min))
+               return -EINVAL;
+       if (min > mddev->resync_max)
+               return -EINVAL;
+       if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
+               return -EBUSY;
+
+       /* Must be a multiple of chunk_size */
+       if (mddev->chunk_size) {
+               if (min & (sector_t)((mddev->chunk_size>>9)-1))
+                       return -EINVAL;
+       }
+       mddev->resync_min = min;
+
+       return len;
+}
+
+static struct md_sysfs_entry md_min_sync =
+__ATTR(sync_min, S_IRUGO|S_IWUSR, min_sync_show, min_sync_store);
+
 static ssize_t
 max_sync_show(mddev_t *mddev, char *page)
 {
@@ -3023,9 +3164,10 @@ max_sync_store(mddev_t *mddev, const char *buf, size_t len)
        if (strncmp(buf, "max", 3) == 0)
                mddev->resync_max = MaxSector;
        else {
-               char *ep;
-               unsigned long long max = simple_strtoull(buf, &ep, 10);
-               if (ep == buf || (*ep != 0 && *ep != '\n'))
+               unsigned long long max;
+               if (strict_strtoull(buf, 10, &max))
+                       return -EINVAL;
+               if (max < mddev->resync_min)
                        return -EINVAL;
                if (max < mddev->resync_max &&
                    test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
@@ -3154,7 +3296,9 @@ static struct attribute *md_redundancy_attrs[] = {
        &md_sync_min.attr,
        &md_sync_max.attr,
        &md_sync_speed.attr,
+       &md_sync_force_parallel.attr,
        &md_sync_completed.attr,
+       &md_min_sync.attr,
        &md_max_sync.attr,
        &md_suspend_lo.attr,
        &md_suspend_hi.attr,
@@ -3259,9 +3403,9 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
        disk->queue = mddev->queue;
        add_disk(disk);
        mddev->gendisk = disk;
-       mutex_unlock(&disks_mutex);
        error = kobject_init_and_add(&mddev->kobj, &md_ktype, &disk->dev.kobj,
                                     "%s", "md");
+       mutex_unlock(&disks_mutex);
        if (error)
                printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
                       disk->disk_name);
@@ -3274,7 +3418,11 @@ static void md_safemode_timeout(unsigned long data)
 {
        mddev_t *mddev = (mddev_t *) data;
 
-       mddev->safemode = 1;
+       if (!atomic_read(&mddev->writes_pending)) {
+               mddev->safemode = 1;
+               if (mddev->external)
+                       sysfs_notify(&mddev->kobj, NULL, "array_state");
+       }
        md_wakeup_thread(mddev->thread);
 }
 
@@ -3381,6 +3529,7 @@ static int do_md_run(mddev_t * mddev)
                                return -EINVAL;
                        }
                }
+               sysfs_notify(&rdev->kobj, NULL, "state");
        }
 
        md_probe(mddev->unit, NULL, NULL);
@@ -3541,6 +3690,9 @@ static int do_md_run(mddev_t * mddev)
 
        mddev->changed = 1;
        md_new_event(mddev);
+       sysfs_notify(&mddev->kobj, NULL, "array_state");
+       sysfs_notify(&mddev->kobj, NULL, "sync_action");
+       sysfs_notify(&mddev->kobj, NULL, "degraded");
        kobject_uevent(&mddev->gendisk->dev.kobj, KOBJ_CHANGE);
        return 0;
 }
@@ -3575,6 +3727,8 @@ static int restart_array(mddev_t *mddev)
                md_wakeup_thread(mddev->thread);
                md_wakeup_thread(mddev->sync_thread);
                err = 0;
+               sysfs_notify(&mddev->kobj, NULL, "array_state");
+
        } else
                err = -EINVAL;
 
@@ -3658,6 +3812,8 @@ static int do_md_stop(mddev_t * mddev, int mode)
 
                        module_put(mddev->pers->owner);
                        mddev->pers = NULL;
+                       /* tell userspace to handle 'inactive' */
+                       sysfs_notify(&mddev->kobj, NULL, "array_state");
 
                        set_capacity(disk, 0);
                        mddev->changed = 1;
@@ -3708,16 +3864,42 @@ static int do_md_stop(mddev_t * mddev, int mode)
                mddev->size = 0;
                mddev->raid_disks = 0;
                mddev->recovery_cp = 0;
+               mddev->resync_min = 0;
                mddev->resync_max = MaxSector;
                mddev->reshape_position = MaxSector;
                mddev->external = 0;
                mddev->persistent = 0;
+               mddev->level = LEVEL_NONE;
+               mddev->clevel[0] = 0;
+               mddev->flags = 0;
+               mddev->ro = 0;
+               mddev->metadata_type[0] = 0;
+               mddev->chunk_size = 0;
+               mddev->ctime = mddev->utime = 0;
+               mddev->layout = 0;
+               mddev->max_disks = 0;
+               mddev->events = 0;
+               mddev->delta_disks = 0;
+               mddev->new_level = LEVEL_NONE;
+               mddev->new_layout = 0;
+               mddev->new_chunk = 0;
+               mddev->curr_resync = 0;
+               mddev->resync_mismatches = 0;
+               mddev->suspend_lo = mddev->suspend_hi = 0;
+               mddev->sync_speed_min = mddev->sync_speed_max = 0;
+               mddev->recovery = 0;
+               mddev->in_sync = 0;
+               mddev->changed = 0;
+               mddev->degraded = 0;
+               mddev->barriers_work = 0;
+               mddev->safemode = 0;
 
        } else if (mddev->pers)
                printk(KERN_INFO "md: %s switched to read-only mode.\n",
                        mdname(mddev));
        err = 0;
        md_new_event(mddev);
+       sysfs_notify(&mddev->kobj, NULL, "array_state");
 out:
        return err;
 }
@@ -3804,8 +3986,10 @@ static void autorun_devices(int part)
 
                md_probe(dev, NULL, NULL);
                mddev = mddev_find(dev);
-               if (!mddev) {
-                       printk(KERN_ERR 
+               if (!mddev || !mddev->gendisk) {
+                       if (mddev)
+                               mddev_put(mddev);
+                       printk(KERN_ERR
                                "md: cannot allocate memory for md drive.\n");
                        break;
                }
@@ -3930,8 +4114,8 @@ static int get_bitmap_file(mddev_t * mddev, void __user * arg)
        if (!buf)
                goto out;
 
-       ptr = file_path(mddev->bitmap->file, buf, sizeof(file->pathname));
-       if (!ptr)
+       ptr = d_path(&mddev->bitmap->file->f_path, buf, sizeof(file->pathname));
+       if (IS_ERR(ptr))
                goto out;
 
        strcpy(file->pathname, ptr);
@@ -4077,8 +4261,12 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
                }
                if (err)
                        export_rdev(rdev);
+               else
+                       sysfs_notify(&rdev->kobj, NULL, "state");
 
                md_update_sb(mddev, 1);
+               if (mddev->degraded)
+                       set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                md_wakeup_thread(mddev->thread);
                return err;
@@ -4137,9 +4325,6 @@ static int hot_remove_disk(mddev_t * mddev, dev_t dev)
        char b[BDEVNAME_SIZE];
        mdk_rdev_t *rdev;
 
-       if (!mddev->pers)
-               return -ENODEV;
-
        rdev = find_rdev(mddev, dev);
        if (!rdev)
                return -ENXIO;
@@ -4716,8 +4901,9 @@ static int md_ioctl(struct inode *inode, struct file *file,
            mddev->ro && mddev->pers) {
                if (mddev->ro == 2) {
                        mddev->ro = 0;
-               set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-               md_wakeup_thread(mddev->thread);
+                       sysfs_notify(&mddev->kobj, NULL, "array_state");
+                       set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+                       md_wakeup_thread(mddev->thread);
 
                } else {
                        err = -EROFS;
@@ -4919,6 +5105,9 @@ void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
 
        if (!rdev || test_bit(Faulty, &rdev->flags))
                return;
+
+       if (mddev->external)
+               set_bit(Blocked, &rdev->flags);
 /*
        dprintk("md_error dev:%s, rdev:(%d:%d), (caller: %p,%p,%p,%p).\n",
                mdname(mddev),
@@ -4931,6 +5120,9 @@ void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
        if (!mddev->pers->error_handler)
                return;
        mddev->pers->error_handler(mddev,rdev);
+       if (mddev->degraded)
+               set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
+       set_bit(StateChanged, &rdev->flags);
        set_bit(MD_RECOVERY_INTR, &mddev->recovery);
        set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
        md_wakeup_thread(mddev->thread);
@@ -5339,7 +5531,7 @@ void md_done_sync(mddev_t *mddev, int blocks, int ok)
        atomic_sub(blocks, &mddev->recovery_active);
        wake_up(&mddev->recovery_wait);
        if (!ok) {
-               set_bit(MD_RECOVERY_ERR, &mddev->recovery);
+               set_bit(MD_RECOVERY_INTR, &mddev->recovery);
                md_wakeup_thread(mddev->thread);
                // stop recovery, signal do_sync ....
        }
@@ -5353,6 +5545,7 @@ void md_done_sync(mddev_t *mddev, int blocks, int ok)
  */
 void md_write_start(mddev_t *mddev, struct bio *bi)
 {
+       int did_change = 0;
        if (bio_data_dir(bi) != WRITE)
                return;
 
@@ -5363,18 +5556,26 @@ void md_write_start(mddev_t *mddev, struct bio *bi)
                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                md_wakeup_thread(mddev->thread);
                md_wakeup_thread(mddev->sync_thread);
+               did_change = 1;
        }
        atomic_inc(&mddev->writes_pending);
+       if (mddev->safemode == 1)
+               mddev->safemode = 0;
        if (mddev->in_sync) {
                spin_lock_irq(&mddev->write_lock);
                if (mddev->in_sync) {
                        mddev->in_sync = 0;
                        set_bit(MD_CHANGE_CLEAN, &mddev->flags);
                        md_wakeup_thread(mddev->thread);
+                       did_change = 1;
                }
                spin_unlock_irq(&mddev->write_lock);
        }
-       wait_event(mddev->sb_wait, mddev->flags==0);
+       if (did_change)
+               sysfs_notify(&mddev->kobj, NULL, "array_state");
+       wait_event(mddev->sb_wait,
+                  !test_bit(MD_CHANGE_CLEAN, &mddev->flags) &&
+                  !test_bit(MD_CHANGE_PENDING, &mddev->flags));
 }
 
 void md_write_end(mddev_t *mddev)
@@ -5399,6 +5600,8 @@ void md_allow_write(mddev_t *mddev)
                return;
        if (mddev->ro)
                return;
+       if (!mddev->pers->sync_request)
+               return;
 
        spin_lock_irq(&mddev->write_lock);
        if (mddev->in_sync) {
@@ -5409,13 +5612,17 @@ void md_allow_write(mddev_t *mddev)
                        mddev->safemode = 1;
                spin_unlock_irq(&mddev->write_lock);
                md_update_sb(mddev, 0);
+
+               sysfs_notify(&mddev->kobj, NULL, "array_state");
+               /* wait for the dirty state to be recorded in the metadata */
+               wait_event(mddev->sb_wait,
+                          !test_bit(MD_CHANGE_CLEAN, &mddev->flags) &&
+                          !test_bit(MD_CHANGE_PENDING, &mddev->flags));
        } else
                spin_unlock_irq(&mddev->write_lock);
 }
 EXPORT_SYMBOL_GPL(md_allow_write);
 
-static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
-
 #define SYNC_MARKS     10
 #define        SYNC_MARK_STEP  (3*HZ)
 void md_do_sync(mddev_t *mddev)
@@ -5479,8 +5686,9 @@ void md_do_sync(mddev_t *mddev)
                for_each_mddev(mddev2, tmp) {
                        if (mddev2 == mddev)
                                continue;
-                       if (mddev2->curr_resync && 
-                           match_mddev_units(mddev,mddev2)) {
+                       if (!mddev->parallel_resync
+                       &&  mddev2->curr_resync
+                       &&  match_mddev_units(mddev, mddev2)) {
                                DEFINE_WAIT(wq);
                                if (mddev < mddev2 && mddev->curr_resync == 2) {
                                        /* arbitrarily yield */
@@ -5517,9 +5725,11 @@ void md_do_sync(mddev_t *mddev)
                max_sectors = mddev->resync_max_sectors;
                mddev->resync_mismatches = 0;
                /* we don't use the checkpoint if there's a bitmap */
-               if (!mddev->bitmap &&
-                   !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+               if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
+                       j = mddev->resync_min;
+               else if (!mddev->bitmap)
                        j = mddev->recovery_cp;
+
        } else if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
                max_sectors = mddev->size << 1;
        else {
@@ -5560,7 +5770,6 @@ void md_do_sync(mddev_t *mddev)
                window/2,(unsigned long long) max_sectors/2);
 
        atomic_set(&mddev->recovery_active, 0);
-       init_waitqueue_head(&mddev->recovery_wait);
        last_check = 0;
 
        if (j>2) {
@@ -5585,7 +5794,7 @@ void md_do_sync(mddev_t *mddev)
                sectors = mddev->pers->sync_request(mddev, j, &skipped,
                                                  currspeed < speed_min(mddev));
                if (sectors == 0) {
-                       set_bit(MD_RECOVERY_ERR, &mddev->recovery);
+                       set_bit(MD_RECOVERY_INTR, &mddev->recovery);
                        goto out;
                }
 
@@ -5608,8 +5817,7 @@ void md_do_sync(mddev_t *mddev)
 
                last_check = io_sectors;
 
-               if (test_bit(MD_RECOVERY_INTR, &mddev->recovery) ||
-                   test_bit(MD_RECOVERY_ERR, &mddev->recovery))
+               if (test_bit(MD_RECOVERY_INTR, &mddev->recovery))
                        break;
 
        repeat:
@@ -5663,8 +5871,7 @@ void md_do_sync(mddev_t *mddev)
        /* tell personality that we are finished */
        mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
 
-       if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
-           !test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
+       if (!test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
            mddev->curr_resync > 2) {
                if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
                        if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
@@ -5691,6 +5898,7 @@ void md_do_sync(mddev_t *mddev)
 
  skip:
        mddev->curr_resync = 0;
+       mddev->resync_min = 0;
        mddev->resync_max = MaxSector;
        sysfs_notify(&mddev->kobj, NULL, "sync_completed");
        wake_up(&resync_wait);
@@ -5719,7 +5927,7 @@ static int remove_and_add_spares(mddev_t *mddev)
 
        rdev_for_each(rdev, rtmp, mddev)
                if (rdev->raid_disk >= 0 &&
-                   !mddev->external &&
+                   !test_bit(Blocked, &rdev->flags) &&
                    (test_bit(Faulty, &rdev->flags) ||
                     ! test_bit(In_sync, &rdev->flags)) &&
                    atomic_read(&rdev->nr_pending)==0) {
@@ -5733,11 +5941,15 @@ static int remove_and_add_spares(mddev_t *mddev)
                }
 
        if (mddev->degraded) {
-               rdev_for_each(rdev, rtmp, mddev)
+               rdev_for_each(rdev, rtmp, mddev) {
+                       if (rdev->raid_disk >= 0 &&
+                           !test_bit(In_sync, &rdev->flags))
+                               spares++;
                        if (rdev->raid_disk < 0
                            && !test_bit(Faulty, &rdev->flags)) {
                                rdev->recovery_offset = 0;
-                               if (mddev->pers->hot_add_disk(mddev,rdev)) {
+                               if (mddev->pers->
+                                   hot_add_disk(mddev, rdev) == 0) {
                                        char nm[20];
                                        sprintf(nm, "rd%d", rdev->raid_disk);
                                        if (sysfs_create_link(&mddev->kobj,
@@ -5751,6 +5963,7 @@ static int remove_and_add_spares(mddev_t *mddev)
                                } else
                                        break;
                        }
+               }
        }
        return spares;
 }
@@ -5764,7 +5977,7 @@ static int remove_and_add_spares(mddev_t *mddev)
  * to do that as needed.
  * When it is determined that resync is needed, we set MD_RECOVERY_RUNNING in
  * "->recovery" and create a thread at ->sync_thread.
- * When the thread finishes it sets MD_RECOVERY_DONE (and might set MD_RECOVERY_ERR)
+ * When the thread finishes it sets MD_RECOVERY_DONE
  * and wakeups up this thread which will reap the thread and finish up.
  * This thread also removes any faulty devices (with nr_pending == 0).
  *
@@ -5789,7 +6002,7 @@ void md_check_recovery(mddev_t *mddev)
                return;
 
        if (signal_pending(current)) {
-               if (mddev->pers->sync_request) {
+               if (mddev->pers->sync_request && !mddev->external) {
                        printk(KERN_INFO "md: %s in immediate safe mode\n",
                               mdname(mddev));
                        mddev->safemode = 2;
@@ -5801,7 +6014,7 @@ void md_check_recovery(mddev_t *mddev)
                (mddev->flags && !mddev->external) ||
                test_bit(MD_RECOVERY_NEEDED, &mddev->recovery) ||
                test_bit(MD_RECOVERY_DONE, &mddev->recovery) ||
-               (mddev->safemode == 1) ||
+               (mddev->external == 0 && mddev->safemode == 1) ||
                (mddev->safemode == 2 && ! atomic_read(&mddev->writes_pending)
                 && !mddev->in_sync && mddev->recovery_cp == MaxSector)
                ))
@@ -5810,20 +6023,32 @@ void md_check_recovery(mddev_t *mddev)
        if (mddev_trylock(mddev)) {
                int spares = 0;
 
-               spin_lock_irq(&mddev->write_lock);
-               if (mddev->safemode && !atomic_read(&mddev->writes_pending) &&
-                   !mddev->in_sync && mddev->recovery_cp == MaxSector) {
-                       mddev->in_sync = 1;
-                       if (mddev->persistent)
-                               set_bit(MD_CHANGE_CLEAN, &mddev->flags);
+               if (!mddev->external) {
+                       int did_change = 0;
+                       spin_lock_irq(&mddev->write_lock);
+                       if (mddev->safemode &&
+                           !atomic_read(&mddev->writes_pending) &&
+                           !mddev->in_sync &&
+                           mddev->recovery_cp == MaxSector) {
+                               mddev->in_sync = 1;
+                               did_change = 1;
+                               if (mddev->persistent)
+                                       set_bit(MD_CHANGE_CLEAN, &mddev->flags);
+                       }
+                       if (mddev->safemode == 1)
+                               mddev->safemode = 0;
+                       spin_unlock_irq(&mddev->write_lock);
+                       if (did_change)
+                               sysfs_notify(&mddev->kobj, NULL, "array_state");
                }
-               if (mddev->safemode == 1)
-                       mddev->safemode = 0;
-               spin_unlock_irq(&mddev->write_lock);
 
                if (mddev->flags)
                        md_update_sb(mddev, 0);
 
+               rdev_for_each(rdev, rtmp, mddev)
+                       if (test_and_clear_bit(StateChanged, &rdev->flags))
+                               sysfs_notify(&rdev->kobj, NULL, "state");
+
 
                if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
                    !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
@@ -5835,11 +6060,12 @@ void md_check_recovery(mddev_t *mddev)
                        /* resync has finished, collect result */
                        md_unregister_thread(mddev->sync_thread);
                        mddev->sync_thread = NULL;
-                       if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
-                           !test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
+                       if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery)) {
                                /* success...*/
                                /* activate any spares */
-                               mddev->pers->spare_active(mddev);
+                               if (mddev->pers->spare_active(mddev))
+                                       sysfs_notify(&mddev->kobj, NULL,
+                                                    "degraded");
                        }
                        md_update_sb(mddev, 1);
 
@@ -5853,14 +6079,18 @@ void md_check_recovery(mddev_t *mddev)
                        mddev->recovery = 0;
                        /* flag recovery needed just to double check */
                        set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
+                       sysfs_notify(&mddev->kobj, NULL, "sync_action");
                        md_new_event(mddev);
                        goto unlock;
                }
+               /* Set RUNNING before clearing NEEDED to avoid
+                * any transients in the value of "sync_action".
+                */
+               set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+               clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                /* Clear some bits that don't mean anything, but
                 * might be left set
                 */
-               clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-               clear_bit(MD_RECOVERY_ERR, &mddev->recovery);
                clear_bit(MD_RECOVERY_INTR, &mddev->recovery);
                clear_bit(MD_RECOVERY_DONE, &mddev->recovery);
 
@@ -5878,17 +6108,19 @@ void md_check_recovery(mddev_t *mddev)
                                /* Cannot proceed */
                                goto unlock;
                        set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
+                       clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                } else if ((spares = remove_and_add_spares(mddev))) {
                        clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
                        clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
+                       set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                } else if (mddev->recovery_cp < MaxSector) {
                        set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
+                       clear_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
                } else if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))
                        /* nothing to be done ... */
                        goto unlock;
 
                if (mddev->pers->sync_request) {
-                       set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
                        if (spares && mddev->bitmap && ! mddev->bitmap->file) {
                                /* We are adding a device or devices to an array
                                 * which has the bitmap stored on all devices.
@@ -5907,13 +6139,30 @@ void md_check_recovery(mddev_t *mddev)
                                mddev->recovery = 0;
                        } else
                                md_wakeup_thread(mddev->sync_thread);
+                       sysfs_notify(&mddev->kobj, NULL, "sync_action");
                        md_new_event(mddev);
                }
        unlock:
+               if (!mddev->sync_thread) {
+                       clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
+                       if (test_and_clear_bit(MD_RECOVERY_RECOVER,
+                                              &mddev->recovery))
+                               sysfs_notify(&mddev->kobj, NULL, "sync_action");
+               }
                mddev_unlock(mddev);
        }
 }
 
+void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
+{
+       sysfs_notify(&rdev->kobj, NULL, "state");
+       wait_event_timeout(rdev->blocked_wait,
+                          !test_bit(Blocked, &rdev->flags),
+                          msecs_to_jiffies(5000));
+       rdev_dec_pending(rdev, mddev);
+}
+EXPORT_SYMBOL(md_wait_for_blocked_rdev);
+
 static int md_notify_reboot(struct notifier_block *this,
                            unsigned long code, void *x)
 {