Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md:
  md: don't retry recovery of raid1 that fails due to error on source drive.
  md: Allow md devices to be created by name.
  md: make devices disappear when they are no longer needed.
  md: centralise all freeing of an 'mddev' in 'md_free'
  md: move allocation of ->queue from mddev_find to md_probe
  md: need another print_sb for mdp_superblock_1
  md: use list_for_each_entry macro directly
  md: raid0: make hash_spacing and preshift sector-based.
  md: raid0: Represent the size of strip zones in sectors.
  md: raid0 create_strip_zones(): Add KERN_INFO/KERN_ERR to printk's.
  md: raid0 create_strip_zones(): Make two local variables sector-based.
  md: raid0: Represent zone->zone_offset in sectors.
  md: raid0: Represent device offset in sectors.
  md: raid0_make_request(): Replace local variable block by sector.
  md: raid0_make_request(): Remove local variable chunk_size.
  md: raid0_make_request(): Replace chunksize_bits by chunksect_bits.
  md: use sysfs_notify_dirent to notify changes to md/sync_action.
  md: fix bitmap-on-external-file bug.

1 files changed, 293 insertions, 123 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 1b1d32694f6f..41e2509bf896 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -214,20 +214,33 @@ static inline mddev_t *mddev_get(mddev_t *mddev)
         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_put(mddev_t *mddev)
 {
         if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
                 return;
-        if (!mddev->raid_disks && list_empty(&mddev->disks)) {
+        if (!mddev->raid_disks && list_empty(&mddev->disks) &&
+            !mddev->hold_active) {
                 list_del(&mddev->all_mddevs);
-                spin_unlock(&all_mddevs_lock);
-                blk_cleanup_queue(mddev->queue);
-                if (mddev->sysfs_state)
-                        sysfs_put(mddev->sysfs_state);
-                mddev->sysfs_state = NULL;
-                kobject_put(&mddev->kobj);
-        } else
-                spin_unlock(&all_mddevs_lock);
+                if (mddev->gendisk) {
+                        /* we did a probe so need to clean up.
+                         * Call schedule_work inside the spinlock
+                         * so that flush_scheduled_work() after
+                         * mddev_find will succeed in waiting for the
+                         * work to be done.
+                         */
+                        INIT_WORK(&mddev->del_work, mddev_delayed_delete);
+                        schedule_work(&mddev->del_work);
+                } else
+                        kfree(mddev);
+        }
+        spin_unlock(&all_mddevs_lock);
 }
 
 static mddev_t * mddev_find(dev_t unit)
@@ -236,15 +249,50 @@ static mddev_t * mddev_find(dev_t unit)
 
  retry:
         spin_lock(&all_mddevs_lock);
-        list_for_each_entry(mddev, &all_mddevs, all_mddevs)
-                if (mddev->unit == unit) {
-                        mddev_get(mddev);
+
+        if (unit) {
+                list_for_each_entry(mddev, &all_mddevs, all_mddevs)
+                        if (mddev->unit == unit) {
+                                mddev_get(mddev);
+                                spin_unlock(&all_mddevs_lock);
+                                kfree(new);
+                                return mddev;
+                        }
+
+                if (new) {
+                        list_add(&new->all_mddevs, &all_mddevs);
                         spin_unlock(&all_mddevs_lock);
-                        kfree(new);
-                        return mddev;
+                        new->hold_active = UNTIL_IOCTL;
+                        return new;
                 }
-
-        if (new) {
+        } else if (new) {
+                /* find an unused unit number */
+                static int next_minor = 512;
+                int start = next_minor;
+                int is_free = 0;
+                int dev = 0;
+                while (!is_free) {
+                        dev = MKDEV(MD_MAJOR, next_minor);
+                        next_minor++;
+                        if (next_minor > MINORMASK)
+                                next_minor = 0;
+                        if (next_minor == start) {
+                                /* Oh dear, all in use. */
+                                spin_unlock(&all_mddevs_lock);
+                                kfree(new);
+                                return NULL;
+                        }
+                                
+                        is_free = 1;
+                        list_for_each_entry(mddev, &all_mddevs, all_mddevs)
+                                if (mddev->unit == dev) {
+                                        is_free = 0;
+                                        break;
+                                }
+                }
+                new->unit = dev;
+                new->md_minor = MINOR(dev);
+                new->hold_active = UNTIL_STOP;
                 list_add(&new->all_mddevs, &all_mddevs);
                 spin_unlock(&all_mddevs_lock);
                 return new;
@@ -275,16 +323,6 @@ static mddev_t * mddev_find(dev_t unit)
         new->resync_max = MaxSector;
         new->level = LEVEL_NONE;
 
-        new->queue = blk_alloc_queue(GFP_KERNEL);
-        if (!new->queue) {
-                kfree(new);
-                return NULL;
-        }
-        /* Can be unlocked because the queue is new: no concurrency */
-        queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, new->queue);
-
-        blk_queue_make_request(new->queue, md_fail_request);
-
         goto retry;
 }
 
@@ -307,25 +345,23 @@ static inline void mddev_unlock(mddev_t * mddev)
 
 static mdk_rdev_t * find_rdev_nr(mddev_t *mddev, int nr)
 {
-        mdk_rdev_t * rdev;
-        struct list_head *tmp;
+        mdk_rdev_t *rdev;
 
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set)
                 if (rdev->desc_nr == nr)
                         return rdev;
-        }
+
         return NULL;
 }
 
 static mdk_rdev_t * find_rdev(mddev_t * mddev, dev_t dev)
 {
-        struct list_head *tmp;
         mdk_rdev_t *rdev;
 
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set)
                 if (rdev->bdev->bd_dev == dev)
                         return rdev;
-        }
+
         return NULL;
 }
 
@@ -861,7 +897,6 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 {
         mdp_super_t *sb;
-        struct list_head *tmp;
         mdk_rdev_t *rdev2;
         int next_spare = mddev->raid_disks;
 
@@ -933,7 +968,7 @@ static void super_90_sync(mddev_t *mddev, mdk_rdev_t *rdev)
                 sb->state |= (1<<MD_SB_BITMAP_PRESENT);
 
         sb->disks[0].state = (1<<MD_DISK_REMOVED);
-        rdev_for_each(rdev2, tmp, mddev) {
+        list_for_each_entry(rdev2, &mddev->disks, same_set) {
                 mdp_disk_t *d;
                 int desc_nr;
                 if (rdev2->raid_disk >= 0 && test_bit(In_sync, &rdev2->flags)
@@ -1259,7 +1294,6 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 {
         struct mdp_superblock_1 *sb;
-        struct list_head *tmp;
         mdk_rdev_t *rdev2;
         int max_dev, i;
         /* make rdev->sb match mddev and rdev data. */
@@ -1307,7 +1341,7 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
         }
 
         max_dev = 0;
-        rdev_for_each(rdev2, tmp, mddev)
+        list_for_each_entry(rdev2, &mddev->disks, same_set)
                 if (rdev2->desc_nr+1 > max_dev)
                         max_dev = rdev2->desc_nr+1;
 
@@ -1316,7 +1350,7 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
         for (i=0; i<max_dev;i++)
                 sb->dev_roles[i] = cpu_to_le16(0xfffe);
         
-        rdev_for_each(rdev2, tmp, mddev) {
+        list_for_each_entry(rdev2, &mddev->disks, same_set) {
                 i = rdev2->desc_nr;
                 if (test_bit(Faulty, &rdev2->flags))
                         sb->dev_roles[i] = cpu_to_le16(0xfffe);
@@ -1466,6 +1500,9 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
 
         list_add_rcu(&rdev->same_set, &mddev->disks);
         bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
+
+        /* May as well allow recovery to be retried once */
+        mddev->recovery_disabled = 0;
         return 0;
 
  fail:
@@ -1571,8 +1608,7 @@ static void kick_rdev_from_array(mdk_rdev_t * rdev)
 
 static void export_array(mddev_t *mddev)
 {
-        struct list_head *tmp;
-        mdk_rdev_t *rdev;
+        mdk_rdev_t *rdev, *tmp;
 
         rdev_for_each(rdev, tmp, mddev) {
                 if (!rdev->mddev) {
@@ -1593,7 +1629,7 @@ static void print_desc(mdp_disk_t *desc)
                 desc->major,desc->minor,desc->raid_disk,desc->state);
 }
 
-static void print_sb(mdp_super_t *sb)
+static void print_sb_90(mdp_super_t *sb)
 {
         int i;
 
@@ -1624,10 +1660,57 @@ static void print_sb(mdp_super_t *sb)
         }
         printk(KERN_INFO "md:     THIS: ");
         print_desc(&sb->this_disk);
-
 }
 
-static void print_rdev(mdk_rdev_t *rdev)
+static void print_sb_1(struct mdp_superblock_1 *sb)
+{
+        __u8 *uuid;
+
+        uuid = sb->set_uuid;
+        printk(KERN_INFO "md:  SB: (V:%u) (F:0x%08x) Array-ID:<%02x%02x%02x%02x"
+                        ":%02x%02x:%02x%02x:%02x%02x:%02x%02x%02x%02x%02x%02x>\n"
+               KERN_INFO "md:    Name: \"%s\" CT:%llu\n",
+                le32_to_cpu(sb->major_version),
+                le32_to_cpu(sb->feature_map),
+                uuid[0], uuid[1], uuid[2], uuid[3],
+                uuid[4], uuid[5], uuid[6], uuid[7],
+                uuid[8], uuid[9], uuid[10], uuid[11],
+                uuid[12], uuid[13], uuid[14], uuid[15],
+                sb->set_name,
+                (unsigned long long)le64_to_cpu(sb->ctime)
+                       & MD_SUPERBLOCK_1_TIME_SEC_MASK);
+
+        uuid = sb->device_uuid;
+        printk(KERN_INFO "md:       L%u SZ%llu RD:%u LO:%u CS:%u DO:%llu DS:%llu SO:%llu"
+                        " RO:%llu\n"
+               KERN_INFO "md:     Dev:%08x UUID: %02x%02x%02x%02x:%02x%02x:%02x%02x:%02x%02x"
+                        ":%02x%02x%02x%02x%02x%02x\n"
+               KERN_INFO "md:       (F:0x%08x) UT:%llu Events:%llu ResyncOffset:%llu CSUM:0x%08x\n"
+               KERN_INFO "md:         (MaxDev:%u) \n",
+                le32_to_cpu(sb->level),
+                (unsigned long long)le64_to_cpu(sb->size),
+                le32_to_cpu(sb->raid_disks),
+                le32_to_cpu(sb->layout),
+                le32_to_cpu(sb->chunksize),
+                (unsigned long long)le64_to_cpu(sb->data_offset),
+                (unsigned long long)le64_to_cpu(sb->data_size),
+                (unsigned long long)le64_to_cpu(sb->super_offset),
+                (unsigned long long)le64_to_cpu(sb->recovery_offset),
+                le32_to_cpu(sb->dev_number),
+                uuid[0], uuid[1], uuid[2], uuid[3],
+                uuid[4], uuid[5], uuid[6], uuid[7],
+                uuid[8], uuid[9], uuid[10], uuid[11],
+                uuid[12], uuid[13], uuid[14], uuid[15],
+                sb->devflags,
+                (unsigned long long)le64_to_cpu(sb->utime) & MD_SUPERBLOCK_1_TIME_SEC_MASK,
+                (unsigned long long)le64_to_cpu(sb->events),
+                (unsigned long long)le64_to_cpu(sb->resync_offset),
+                le32_to_cpu(sb->sb_csum),
+                le32_to_cpu(sb->max_dev)
+                );
+}
+
+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",
@@ -1635,15 +1718,22 @@ static void print_rdev(mdk_rdev_t *rdev)
                 test_bit(Faulty, &rdev->flags), test_bit(In_sync, &rdev->flags),
                 rdev->desc_nr);
         if (rdev->sb_loaded) {
-                printk(KERN_INFO "md: rdev superblock:\n");
-                print_sb((mdp_super_t*)page_address(rdev->sb_page));
+                printk(KERN_INFO "md: rdev superblock (MJ:%d):\n", major_version);
+                switch (major_version) {
+                case 0:
+                        print_sb_90((mdp_super_t*)page_address(rdev->sb_page));
+                        break;
+                case 1:
+                        print_sb_1((struct mdp_superblock_1 *)page_address(rdev->sb_page));
+                        break;
+                }
         } else
                 printk(KERN_INFO "md: no rdev superblock!\n");
 }
 
 static void md_print_devices(void)
 {
-        struct list_head *tmp, *tmp2;
+        struct list_head *tmp;
         mdk_rdev_t *rdev;
         mddev_t *mddev;
         char b[BDEVNAME_SIZE];
@@ -1658,12 +1748,12 @@ static void md_print_devices(void)
                         bitmap_print_sb(mddev->bitmap);
                 else
                         printk("%s: ", mdname(mddev));
-                rdev_for_each(rdev, tmp2, mddev)
+                list_for_each_entry(rdev, &mddev->disks, same_set)
                         printk("<%s>", bdevname(rdev->bdev,b));
                 printk("\n");
 
-                rdev_for_each(rdev, tmp2, mddev)
-                        print_rdev(rdev);
+                list_for_each_entry(rdev, &mddev->disks, same_set)
+                        print_rdev(rdev, mddev->major_version);
         }
         printk("md:     **********************************\n");
         printk("\n");
@@ -1679,9 +1769,8 @@ static void sync_sbs(mddev_t * mddev, int nospares)
          * with the rest of the array)
          */
         mdk_rdev_t *rdev;
-        struct list_head *tmp;
 
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
                 if (rdev->sb_events == mddev->events ||
                     (nospares &&
                      rdev->raid_disk < 0 &&
@@ -1699,7 +1788,6 @@ static void sync_sbs(mddev_t * mddev, int nospares)
 
 static void md_update_sb(mddev_t * mddev, int force_change)
 {
-        struct list_head *tmp;
         mdk_rdev_t *rdev;
         int sync_req;
         int nospares = 0;
@@ -1790,7 +1878,7 @@ repeat:
                 mdname(mddev),mddev->in_sync);
 
         bitmap_update_sb(mddev->bitmap);
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
                 char b[BDEVNAME_SIZE];
                 dprintk(KERN_INFO "md: ");
                 if (rdev->sb_loaded != 1)
@@ -1999,7 +2087,6 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                 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.
                  */
@@ -2010,7 +2097,7 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                 if (rdev->mddev->pers->hot_add_disk == NULL)
                         return -EINVAL;
 
-                rdev_for_each(rdev2, tmp, rdev->mddev)
+                list_for_each_entry(rdev2, &rdev->mddev->disks, same_set)
                         if (rdev2->raid_disk == slot)
                                 return -EEXIST;
 
@@ -2125,14 +2212,14 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                  */
                 mddev_t *mddev;
                 int overlap = 0;
-                struct list_head *tmp, *tmp2;
+                struct list_head *tmp;
 
                 mddev_unlock(my_mddev);
                 for_each_mddev(mddev, tmp) {
                         mdk_rdev_t *rdev2;
 
                         mddev_lock(mddev);
-                        rdev_for_each(rdev2, tmp2, mddev)
+                        list_for_each_entry(rdev2, &mddev->disks, same_set)
                                 if (test_bit(AllReserved, &rdev2->flags) ||
                                     (rdev->bdev == rdev2->bdev &&
                                      rdev != rdev2 &&
@@ -2328,8 +2415,7 @@ abort_free:
 static void analyze_sbs(mddev_t * mddev)
 {
         int i;
-        struct list_head *tmp;
-        mdk_rdev_t *rdev, *freshest;
+        mdk_rdev_t *rdev, *freshest, *tmp;
         char b[BDEVNAME_SIZE];
 
         freshest = NULL;
@@ -3046,7 +3132,7 @@ 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");
+        sysfs_notify_dirent(mddev->sysfs_action);
         return len;
 }
 
@@ -3404,6 +3490,8 @@ md_attr_store(struct kobject *kobj, struct attribute *attr,
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
         rv = mddev_lock(mddev);
+        if (mddev->hold_active == UNTIL_IOCTL)
+                mddev->hold_active = 0;
         if (!rv) {
                 rv = entry->store(mddev, page, length);
                 mddev_unlock(mddev);
@@ -3414,6 +3502,17 @@ md_attr_store(struct kobject *kobj, struct attribute *attr,
 static void md_free(struct kobject *ko)
 {
         mddev_t *mddev = container_of(ko, mddev_t, kobj);
+
+        if (mddev->sysfs_state)
+                sysfs_put(mddev->sysfs_state);
+
+        if (mddev->gendisk) {
+                del_gendisk(mddev->gendisk);
+                put_disk(mddev->gendisk);
+        }
+        if (mddev->queue)
+                blk_cleanup_queue(mddev->queue);
+
         kfree(mddev);
 }
 
@@ -3429,34 +3528,74 @@ static struct kobj_type md_ktype = {
 
 int mdp_major = 0;
 
-static struct kobject *md_probe(dev_t dev, int *part, void *data)
+static int md_alloc(dev_t dev, char *name)
 {
         static DEFINE_MUTEX(disks_mutex);
         mddev_t *mddev = mddev_find(dev);
         struct gendisk *disk;
-        int partitioned = (MAJOR(dev) != MD_MAJOR);
-        int shift = partitioned ? MdpMinorShift : 0;
-        int unit = MINOR(dev) >> shift;
+        int partitioned;
+        int shift;
+        int unit;
         int error;
 
         if (!mddev)
-                return NULL;
+                return -ENODEV;
+
+        partitioned = (MAJOR(mddev->unit) != MD_MAJOR);
+        shift = partitioned ? MdpMinorShift : 0;
+        unit = MINOR(mddev->unit) >> shift;
+
+        /* wait for any previous instance if this device
+         * to be completed removed (mddev_delayed_delete).
+         */
+        flush_scheduled_work();
 
         mutex_lock(&disks_mutex);
         if (mddev->gendisk) {
                 mutex_unlock(&disks_mutex);
                 mddev_put(mddev);
-                return NULL;
+                return -EEXIST;
+        }
+
+        if (name) {
+                /* Need to ensure that 'name' is not a duplicate.
+                 */
+                mddev_t *mddev2;
+                spin_lock(&all_mddevs_lock);
+
+                list_for_each_entry(mddev2, &all_mddevs, all_mddevs)
+                        if (mddev2->gendisk &&
+                            strcmp(mddev2->gendisk->disk_name, name) == 0) {
+                                spin_unlock(&all_mddevs_lock);
+                                return -EEXIST;
+                        }
+                spin_unlock(&all_mddevs_lock);
+        }
+
+        mddev->queue = blk_alloc_queue(GFP_KERNEL);
+        if (!mddev->queue) {
+                mutex_unlock(&disks_mutex);
+                mddev_put(mddev);
+                return -ENOMEM;
         }
+        /* 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);
+
         disk = alloc_disk(1 << shift);
         if (!disk) {
                 mutex_unlock(&disks_mutex);
+                blk_cleanup_queue(mddev->queue);
+                mddev->queue = NULL;
                 mddev_put(mddev);
-                return NULL;
+                return -ENOMEM;
         }
-        disk->major = MAJOR(dev);
+        disk->major = MAJOR(mddev->unit);
         disk->first_minor = unit << shift;
-        if (partitioned)
+        if (name)
+                strcpy(disk->disk_name, name);
+        else if (partitioned)
                 sprintf(disk->disk_name, "md_d%d", unit);
         else
                 sprintf(disk->disk_name, "md%d", unit);
@@ -3464,7 +3603,7 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
         disk->private_data = mddev;
         disk->queue = mddev->queue;
         /* Allow extended partitions.  This makes the
-         * 'mdp' device redundant, but we can really
+         * 'mdp' device redundant, but we can't really
          * remove it now.
          */
         disk->flags |= GENHD_FL_EXT_DEVT;
@@ -3480,9 +3619,35 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
                 kobject_uevent(&mddev->kobj, KOBJ_ADD);
                 mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, "array_state");
         }
+        mddev_put(mddev);
+        return 0;
+}
+
+static struct kobject *md_probe(dev_t dev, int *part, void *data)
+{
+        md_alloc(dev, NULL);
         return NULL;
 }
 
+static int add_named_array(const char *val, struct kernel_param *kp)
+{
+        /* val must be "md_*" where * is not all digits.
+         * We allocate an array with a large free minor number, and
+         * set the name to val.  val must not already be an active name.
+         */
+        int len = strlen(val);
+        char buf[DISK_NAME_LEN];
+
+        while (len && val[len-1] == '\n')
+                len--;
+        if (len >= DISK_NAME_LEN)
+                return -E2BIG;
+        strlcpy(buf, val, len+1);
+        if (strncmp(buf, "md_", 3) != 0)
+                return -EINVAL;
+        return md_alloc(0, buf);
+}
+
 static void md_safemode_timeout(unsigned long data)
 {
         mddev_t *mddev = (mddev_t *) data;
@@ -3501,7 +3666,6 @@ static int do_md_run(mddev_t * mddev)
 {
         int err;
         int chunk_size;
-        struct list_head *tmp;
         mdk_rdev_t *rdev;
         struct gendisk *disk;
         struct mdk_personality *pers;
@@ -3540,7 +3704,7 @@ static int do_md_run(mddev_t * mddev)
                 }
 
                 /* devices must have minimum size of one chunk */
-                rdev_for_each(rdev, tmp, mddev) {
+                list_for_each_entry(rdev, &mddev->disks, same_set) {
                         if (test_bit(Faulty, &rdev->flags))
                                 continue;
                         if (rdev->size < chunk_size / 1024) {
@@ -3565,7 +3729,7 @@ static int do_md_run(mddev_t * mddev)
          * the only valid external interface is through the md
          * device.
          */
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
                 if (test_bit(Faulty, &rdev->flags))
                         continue;
                 sync_blockdev(rdev->bdev);
@@ -3630,10 +3794,10 @@ static int do_md_run(mddev_t * mddev)
                  */
                 char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
                 mdk_rdev_t *rdev2;
-                struct list_head *tmp2;
                 int warned = 0;
-                rdev_for_each(rdev, tmp, mddev) {
-                        rdev_for_each(rdev2, tmp2, mddev) {
+
+                list_for_each_entry(rdev, &mddev->disks, same_set)
+                        list_for_each_entry(rdev2, &mddev->disks, same_set) {
                                 if (rdev < rdev2 &&
                                     rdev->bdev->bd_contains ==
                                     rdev2->bdev->bd_contains) {
@@ -3647,7 +3811,7 @@ static int do_md_run(mddev_t * mddev)
                                         warned = 1;
                                 }
                         }
-                }
+
                 if (warned)
                         printk(KERN_WARNING
                                "True protection against single-disk"
@@ -3684,6 +3848,7 @@ static int do_md_run(mddev_t * mddev)
                         printk(KERN_WARNING
                                "md: cannot register extra attributes for %s\n",
                                mdname(mddev));
+                mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, "sync_action");
         } else if (mddev->ro == 2) /* auto-readonly not meaningful */
                 mddev->ro = 0;
 
@@ -3694,7 +3859,7 @@ static int do_md_run(mddev_t * mddev)
         mddev->safemode_delay = (200 * HZ)/1000 +1; /* 200 msec delay */
         mddev->in_sync = 1;
 
-        rdev_for_each(rdev, tmp, mddev)
+        list_for_each_entry(rdev, &mddev->disks, same_set)
                 if (rdev->raid_disk >= 0) {
                         char nm[20];
                         sprintf(nm, "rd%d", rdev->raid_disk);
@@ -3725,9 +3890,8 @@ static int do_md_run(mddev_t * mddev)
          * it will remove the drives and not do the right thing
          */
         if (mddev->degraded && !mddev->sync_thread) {
-                struct list_head *rtmp;
                 int spares = 0;
-                rdev_for_each(rdev, rtmp, mddev)
+                list_for_each_entry(rdev, &mddev->disks, same_set)
                         if (rdev->raid_disk >= 0 &&
                             !test_bit(In_sync, &rdev->flags) &&
                             !test_bit(Faulty, &rdev->flags))
@@ -3754,7 +3918,8 @@ static int do_md_run(mddev_t * mddev)
         mddev->changed = 1;
         md_new_event(mddev);
         sysfs_notify_dirent(mddev->sysfs_state);
-        sysfs_notify(&mddev->kobj, NULL, "sync_action");
+        if (mddev->sysfs_action)
+                sysfs_notify_dirent(mddev->sysfs_action);
         sysfs_notify(&mddev->kobj, NULL, "degraded");
         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
         return 0;
@@ -3854,9 +4019,12 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                         mddev->queue->merge_bvec_fn = NULL;
                         mddev->queue->unplug_fn = NULL;
                         mddev->queue->backing_dev_info.congested_fn = NULL;
-                        if (mddev->pers->sync_request)
+                        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);
                         mddev->pers = NULL;
                         /* tell userspace to handle 'inactive' */
@@ -3883,7 +4051,6 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
          */
         if (mode == 0) {
                 mdk_rdev_t *rdev;
-                struct list_head *tmp;
 
                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
 
@@ -3895,7 +4062,7 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                 }
                 mddev->bitmap_offset = 0;
 
-                rdev_for_each(rdev, tmp, mddev)
+                list_for_each_entry(rdev, &mddev->disks, same_set)
                         if (rdev->raid_disk >= 0) {
                                 char nm[20];
                                 sprintf(nm, "rd%d", rdev->raid_disk);
@@ -3941,6 +4108,8 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                 mddev->barriers_work = 0;
                 mddev->safemode = 0;
                 kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
+                if (mddev->hold_active == UNTIL_STOP)
+                        mddev->hold_active = 0;
 
         } else if (mddev->pers)
                 printk(KERN_INFO "md: %s switched to read-only mode.\n",
@@ -3956,7 +4125,6 @@ out:
 static void autorun_array(mddev_t *mddev)
 {
         mdk_rdev_t *rdev;
-        struct list_head *tmp;
         int err;
 
         if (list_empty(&mddev->disks))
@@ -3964,7 +4132,7 @@ static void autorun_array(mddev_t *mddev)
 
         printk(KERN_INFO "md: running: ");
 
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
                 char b[BDEVNAME_SIZE];
                 printk("<%s>", bdevname(rdev->bdev,b));
         }
@@ -3991,8 +4159,7 @@ static void autorun_array(mddev_t *mddev)
  */
 static void autorun_devices(int part)
 {
-        struct list_head *tmp;
-        mdk_rdev_t *rdev0, *rdev;
+        mdk_rdev_t *rdev0, *rdev, *tmp;
         mddev_t *mddev;
         char b[BDEVNAME_SIZE];
 
@@ -4007,7 +4174,7 @@ static void autorun_devices(int part)
                 printk(KERN_INFO "md: considering %s ...\n",
                         bdevname(rdev0->bdev,b));
                 INIT_LIST_HEAD(&candidates);
-                rdev_for_each_list(rdev, tmp, pending_raid_disks)
+                rdev_for_each_list(rdev, tmp, &pending_raid_disks)
                         if (super_90_load(rdev, rdev0, 0) >= 0) {
                                 printk(KERN_INFO "md:  adding %s ...\n",
                                         bdevname(rdev->bdev,b));
@@ -4053,7 +4220,7 @@ static void autorun_devices(int part)
                 } else {
                         printk(KERN_INFO "md: created %s\n", mdname(mddev));
                         mddev->persistent = 1;
-                        rdev_for_each_list(rdev, tmp, candidates) {
+                        rdev_for_each_list(rdev, tmp, &candidates) {
                                 list_del_init(&rdev->same_set);
                                 if (bind_rdev_to_array(rdev, mddev))
                                         export_rdev(rdev);
@@ -4064,7 +4231,7 @@ static void autorun_devices(int part)
                 /* on success, candidates will be empty, on error
                  * it won't...
                  */
-                rdev_for_each_list(rdev, tmp, candidates) {
+                rdev_for_each_list(rdev, tmp, &candidates) {
                         list_del_init(&rdev->same_set);
                         export_rdev(rdev);
                 }
@@ -4093,10 +4260,9 @@ static int get_array_info(mddev_t * mddev, void __user * arg)
         mdu_array_info_t info;
         int nr,working,active,failed,spare;
         mdk_rdev_t *rdev;
-        struct list_head *tmp;
 
         nr=working=active=failed=spare=0;
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
                 nr++;
                 if (test_bit(Faulty, &rdev->flags))
                         failed++;
@@ -4614,9 +4780,8 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
 
 static int update_size(mddev_t *mddev, sector_t num_sectors)
 {
-        mdk_rdev_t * rdev;
+        mdk_rdev_t *rdev;
         int rv;
-        struct list_head *tmp;
         int fit = (num_sectors == 0);
 
         if (mddev->pers->resize == NULL)
@@ -4638,7 +4803,7 @@ static int update_size(mddev_t *mddev, sector_t num_sectors)
                  * grow, and re-add.
                  */
                 return -EBUSY;
-        rdev_for_each(rdev, tmp, mddev) {
+        list_for_each_entry(rdev, &mddev->disks, same_set) {
                 sector_t avail;
                 avail = rdev->size * 2;
 
@@ -5000,6 +5165,9 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
 
 done_unlock:
 abort_unlock:
+        if (mddev->hold_active == UNTIL_IOCTL &&
+            err != -EINVAL)
+                mddev->hold_active = 0;
         mddev_unlock(mddev);
 
         return err;
@@ -5016,14 +5184,25 @@ static int md_open(struct block_device *bdev, fmode_t mode)
          * Succeed if we can lock the mddev, which confirms that
          * it isn't being stopped right now.
          */
-        mddev_t *mddev = bdev->bd_disk->private_data;
+        mddev_t *mddev = mddev_find(bdev->bd_dev);
         int err;
 
+        if (mddev->gendisk != bdev->bd_disk) {
+                /* we are racing with mddev_put which is discarding this
+                 * bd_disk.
+                 */
+                mddev_put(mddev);
+                /* Wait until bdev->bd_disk is definitely gone */
+                flush_scheduled_work();
+                /* Then retry the open from the top */
+                return -ERESTARTSYS;
+        }
+        BUG_ON(mddev != bdev->bd_disk->private_data);
+
         if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1)))
                 goto out;
 
         err = 0;
-        mddev_get(mddev);
         atomic_inc(&mddev->openers);
         mddev_unlock(mddev);
 
@@ -5187,11 +5366,10 @@ static void status_unused(struct seq_file *seq)
 {
         int i = 0;
         mdk_rdev_t *rdev;
-        struct list_head *tmp;
 
         seq_printf(seq, "unused devices: ");
 
-        rdev_for_each_list(rdev, tmp, pending_raid_disks) {
+        list_for_each_entry(rdev, &pending_raid_disks, same_set) {
                 char b[BDEVNAME_SIZE];
                 i++;
                 seq_printf(seq, "%s ",
@@ -5350,7 +5528,6 @@ static int md_seq_show(struct seq_file *seq, void *v)
 {
         mddev_t *mddev = v;
         sector_t size;
-        struct list_head *tmp2;
         mdk_rdev_t *rdev;
         struct mdstat_info *mi = seq->private;
         struct bitmap *bitmap;
@@ -5387,7 +5564,7 @@ static int md_seq_show(struct seq_file *seq, void *v)
                 }
 
                 size = 0;
-                rdev_for_each(rdev, tmp2, mddev) {
+                list_for_each_entry(rdev, &mddev->disks, same_set) {
                         char b[BDEVNAME_SIZE];
                         seq_printf(seq, " %s[%d]",
                                 bdevname(rdev->bdev,b), rdev->desc_nr);
@@ -5694,7 +5871,6 @@ void md_do_sync(mddev_t *mddev)
         struct list_head *tmp;
         sector_t last_check;
         int skipped = 0;
-        struct list_head *rtmp;
         mdk_rdev_t *rdev;
         char *desc;
 
@@ -5799,7 +5975,7 @@ void md_do_sync(mddev_t *mddev)
                 /* recovery follows the physical size of devices */
                 max_sectors = mddev->size << 1;
                 j = MaxSector;
-                rdev_for_each(rdev, rtmp, mddev)
+                list_for_each_entry(rdev, &mddev->disks, same_set)
                         if (rdev->raid_disk >= 0 &&
                             !test_bit(Faulty, &rdev->flags) &&
                             !test_bit(In_sync, &rdev->flags) &&
@@ -5949,7 +6125,7 @@ void md_do_sync(mddev_t *mddev)
                 } else {
                         if (!test_bit(MD_RECOVERY_INTR, &mddev->recovery))
                                 mddev->curr_resync = MaxSector;
-                        rdev_for_each(rdev, rtmp, mddev)
+                        list_for_each_entry(rdev, &mddev->disks, same_set)
                                 if (rdev->raid_disk >= 0 &&
                                     !test_bit(Faulty, &rdev->flags) &&
                                     !test_bit(In_sync, &rdev->flags) &&
@@ -5985,10 +6161,9 @@ EXPORT_SYMBOL_GPL(md_do_sync);
 static int remove_and_add_spares(mddev_t *mddev)
 {
         mdk_rdev_t *rdev;
-        struct list_head *rtmp;
         int spares = 0;
 
-        rdev_for_each(rdev, rtmp, mddev)
+        list_for_each_entry(rdev, &mddev->disks, same_set)
                 if (rdev->raid_disk >= 0 &&
                     !test_bit(Blocked, &rdev->flags) &&
                     (test_bit(Faulty, &rdev->flags) ||
@@ -6003,8 +6178,8 @@ static int remove_and_add_spares(mddev_t *mddev)
                         }
                 }
 
-        if (mddev->degraded && ! mddev->ro) {
-                rdev_for_each(rdev, rtmp, mddev) {
+        if (mddev->degraded && ! mddev->ro && !mddev->recovery_disabled) {
+                list_for_each_entry(rdev, &mddev->disks, same_set) {
                         if (rdev->raid_disk >= 0 &&
                             !test_bit(In_sync, &rdev->flags) &&
                             !test_bit(Blocked, &rdev->flags))
@@ -6056,7 +6231,6 @@ static int remove_and_add_spares(mddev_t *mddev)
 void md_check_recovery(mddev_t *mddev)
 {
         mdk_rdev_t *rdev;
-        struct list_head *rtmp;
 
 
         if (mddev->bitmap)
@@ -6120,7 +6294,7 @@ void md_check_recovery(mddev_t *mddev)
                 if (mddev->flags)
                         md_update_sb(mddev, 0);
 
-                rdev_for_each(rdev, rtmp, mddev)
+                list_for_each_entry(rdev, &mddev->disks, same_set)
                         if (test_and_clear_bit(StateChanged, &rdev->flags))
                                 sysfs_notify_dirent(rdev->sysfs_state);
 
@@ -6149,13 +6323,13 @@ void md_check_recovery(mddev_t *mddev)
                          * information must be scrapped
                          */
                         if (!mddev->degraded)
-                                rdev_for_each(rdev, rtmp, mddev)
+                                list_for_each_entry(rdev, &mddev->disks, same_set)
                                         rdev->saved_raid_disk = -1;
 
                         mddev->recovery = 0;
                         /* flag recovery needed just to double check */
                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-                        sysfs_notify(&mddev->kobj, NULL, "sync_action");
+                        sysfs_notify_dirent(mddev->sysfs_action);
                         md_new_event(mddev);
                         goto unlock;
                 }
@@ -6216,7 +6390,7 @@ void md_check_recovery(mddev_t *mddev)
                                 mddev->recovery = 0;
                         } else
                                 md_wakeup_thread(mddev->sync_thread);
-                        sysfs_notify(&mddev->kobj, NULL, "sync_action");
+                        sysfs_notify_dirent(mddev->sysfs_action);
                         md_new_event(mddev);
                 }
         unlock:
@@ -6224,7 +6398,8 @@ void md_check_recovery(mddev_t *mddev)
                         clear_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
                         if (test_and_clear_bit(MD_RECOVERY_RECOVER,
                                                &mddev->recovery))
-                                sysfs_notify(&mddev->kobj, NULL, "sync_action");
+                                if (mddev->sysfs_action)
+                                        sysfs_notify_dirent(mddev->sysfs_action);
                 }
                 mddev_unlock(mddev);
         }
@@ -6386,14 +6561,8 @@ static __exit void md_exit(void)
         unregister_sysctl_table(raid_table_header);
         remove_proc_entry("mdstat", NULL);
         for_each_mddev(mddev, tmp) {
-                struct gendisk *disk = mddev->gendisk;
-                if (!disk)
-                        continue;
                 export_array(mddev);
-                del_gendisk(disk);
-                put_disk(disk);
-                mddev->gendisk = NULL;
-                mddev_put(mddev);
+                mddev->hold_active = 0;
         }
 }
 
@@ -6418,6 +6587,7 @@ static int set_ro(const char *val, struct kernel_param *kp)
 module_param_call(start_ro, set_ro, get_ro, NULL, S_IRUSR|S_IWUSR);
 module_param(start_dirty_degraded, int, S_IRUGO|S_IWUSR);
 
+module_param_call(new_array, add_named_array, NULL, NULL, S_IWUSR);
 
 EXPORT_SYMBOL(register_md_personality);
 EXPORT_SYMBOL(unregister_md_personality);