Freezer: make kernel threads nonfreezable by default
[safe/jmp/linux-2.6] / drivers / md / md.c
index d2bcb41..9aefc4a 100644 (file)
@@ -33,6 +33,7 @@
 */
 
 #include <linux/module.h>
+#include <linux/kernel.h>
 #include <linux/kthread.h>
 #include <linux/linkage.h>
 #include <linux/raid/md.h>
@@ -273,6 +274,7 @@ 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);
+       new->reshape_position = MaxSector;
 
        new->queue = blk_alloc_queue(GFP_KERNEL);
        if (!new->queue) {
@@ -589,14 +591,41 @@ abort:
        return ret;
 }
 
+
+static u32 md_csum_fold(u32 csum)
+{
+       csum = (csum & 0xffff) + (csum >> 16);
+       return (csum & 0xffff) + (csum >> 16);
+}
+
 static unsigned int calc_sb_csum(mdp_super_t * sb)
 {
+       u64 newcsum = 0;
+       u32 *sb32 = (u32*)sb;
+       int i;
        unsigned int disk_csum, csum;
 
        disk_csum = sb->sb_csum;
        sb->sb_csum = 0;
-       csum = csum_partial((void *)sb, MD_SB_BYTES, 0);
+
+       for (i = 0; i < MD_SB_BYTES/4 ; i++)
+               newcsum += sb32[i];
+       csum = (newcsum & 0xffffffff) + (newcsum>>32);
+
+
+#ifdef CONFIG_ALPHA
+       /* This used to use csum_partial, which was wrong for several
+        * reasons including that different results are returned on
+        * different architectures.  It isn't critical that we get exactly
+        * the same return value as before (we always csum_fold before
+        * testing, and that removes any differences).  However as we
+        * know that csum_partial always returned a 16bit value on
+        * alphas, do a fold to maximise conformity to previous behaviour.
+        */
+       sb->sb_csum = md_csum_fold(disk_csum);
+#else
        sb->sb_csum = disk_csum;
+#endif
        return csum;
 }
 
@@ -684,7 +713,7 @@ static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version
        if (sb->raid_disks <= 0)
                goto abort;
 
-       if (csum_fold(calc_sb_csum(sb)) != csum_fold(sb->sb_csum)) {
+       if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
                printk(KERN_WARNING "md: invalid superblock checksum on %s\n",
                        b);
                goto abort;
@@ -694,6 +723,17 @@ static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version
        rdev->data_offset = 0;
        rdev->sb_size = MD_SB_BYTES;
 
+       if (sb->state & (1<<MD_SB_BITMAP_PRESENT)) {
+               if (sb->level != 1 && sb->level != 4
+                   && sb->level != 5 && sb->level != 6
+                   && sb->level != 10) {
+                       /* FIXME use a better test */
+                       printk(KERN_WARNING
+                              "md: bitmaps not supported for this level.\n");
+                       goto abort;
+               }
+       }
+
        if (sb->level == LEVEL_MULTIPATH)
                rdev->desc_nr = -1;
        else
@@ -792,16 +832,8 @@ static int super_90_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                mddev->max_disks = MD_SB_DISKS;
 
                if (sb->state & (1<<MD_SB_BITMAP_PRESENT) &&
-                   mddev->bitmap_file == NULL) {
-                       if (mddev->level != 1 && mddev->level != 4
-                           && mddev->level != 5 && mddev->level != 6
-                           && mddev->level != 10) {
-                               /* FIXME use a better test */
-                               printk(KERN_WARNING "md: bitmaps not supported for this level.\n");
-                               return -EINVAL;
-                       }
+                   mddev->bitmap_file == NULL)
                        mddev->bitmap_offset = mddev->default_bitmap_offset;
-               }
 
        } else if (mddev->pers == NULL) {
                /* Insist on good event counter while assembling */
@@ -1058,6 +1090,18 @@ static int super_1_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version)
                       bdevname(rdev->bdev,b));
                return -EINVAL;
        }
+       if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET)) {
+               if (sb->level != cpu_to_le32(1) &&
+                   sb->level != cpu_to_le32(4) &&
+                   sb->level != cpu_to_le32(5) &&
+                   sb->level != cpu_to_le32(6) &&
+                   sb->level != cpu_to_le32(10)) {
+                       printk(KERN_WARNING
+                              "md: bitmaps not supported for this level.\n");
+                       return -EINVAL;
+               }
+       }
+
        rdev->preferred_minor = 0xffff;
        rdev->data_offset = le64_to_cpu(sb->data_offset);
        atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
@@ -1141,14 +1185,9 @@ static int super_1_validate(mddev_t *mddev, mdk_rdev_t *rdev)
                mddev->max_disks =  (4096-256)/2;
 
                if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET) &&
-                   mddev->bitmap_file == NULL ) {
-                       if (mddev->level != 1 && mddev->level != 5 && mddev->level != 6
-                           && mddev->level != 10) {
-                               printk(KERN_WARNING "md: bitmaps not supported for this level.\n");
-                               return -EINVAL;
-                       }
+                   mddev->bitmap_file == NULL )
                        mddev->bitmap_offset = (__s32)le32_to_cpu(sb->bitmap_offset);
-               }
+
                if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE)) {
                        mddev->reshape_position = le64_to_cpu(sb->reshape_position);
                        mddev->delta_disks = le32_to_cpu(sb->delta_disks);
@@ -1259,8 +1298,9 @@ static void super_1_sync(mddev_t *mddev, mdk_rdev_t *rdev)
        ITERATE_RDEV(mddev,rdev2,tmp)
                if (rdev2->desc_nr+1 > max_dev)
                        max_dev = rdev2->desc_nr+1;
-       
-       sb->max_dev = cpu_to_le32(max_dev);
+
+       if (max_dev > le32_to_cpu(sb->max_dev))
+               sb->max_dev = cpu_to_le32(max_dev);
        for (i=0; i<max_dev;i++)
                sb->dev_roles[i] = cpu_to_le16(0xfffe);
        
@@ -1296,27 +1336,17 @@ static struct super_type super_types[] = {
                .sync_super     = super_1_sync,
        },
 };
-       
-static mdk_rdev_t * match_dev_unit(mddev_t *mddev, mdk_rdev_t *dev)
-{
-       struct list_head *tmp;
-       mdk_rdev_t *rdev;
-
-       ITERATE_RDEV(mddev,rdev,tmp)
-               if (rdev->bdev->bd_contains == dev->bdev->bd_contains)
-                       return rdev;
-
-       return NULL;
-}
 
 static int match_mddev_units(mddev_t *mddev1, mddev_t *mddev2)
 {
-       struct list_head *tmp;
-       mdk_rdev_t *rdev;
+       struct list_head *tmp, *tmp2;
+       mdk_rdev_t *rdev, *rdev2;
 
        ITERATE_RDEV(mddev1,rdev,tmp)
-               if (match_dev_unit(mddev2, rdev))
-                       return 1;
+               ITERATE_RDEV(mddev2, rdev2, tmp2)
+                       if (rdev->bdev->bd_contains ==
+                           rdev2->bdev->bd_contains)
+                               return 1;
 
        return 0;
 }
@@ -1325,10 +1355,10 @@ static LIST_HEAD(pending_raid_disks);
 
 static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
 {
-       mdk_rdev_t *same_pdev;
-       char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
+       char b[BDEVNAME_SIZE];
        struct kobject *ko;
        char *s;
+       int err;
 
        if (rdev->mddev) {
                MD_BUG();
@@ -1336,20 +1366,16 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
        }
        /* make sure rdev->size exceeds mddev->size */
        if (rdev->size && (mddev->size == 0 || rdev->size < mddev->size)) {
-               if (mddev->pers)
-                       /* Cannot change size, so fail */
-                       return -ENOSPC;
-               else
+               if (mddev->pers) {
+                       /* Cannot change size, so fail
+                        * If mddev->level <= 0, then we don't care
+                        * about aligning sizes (e.g. linear)
+                        */
+                       if (mddev->level > 0)
+                               return -ENOSPC;
+               } else
                        mddev->size = rdev->size;
        }
-       same_pdev = match_dev_unit(mddev, rdev);
-       if (same_pdev)
-               printk(KERN_WARNING
-                       "%s: WARNING: %s appears to be on the same physical"
-                       " disk as %s. True\n     protection against single-disk"
-                       " failure might be compromised.\n",
-                       mdname(mddev), bdevname(rdev->bdev,b),
-                       bdevname(same_pdev->bdev,b2));
 
        /* Verify rdev->desc_nr is unique.
         * If it is -1, assign a free number, else
@@ -1371,20 +1397,35 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
        while ( (s=strchr(rdev->kobj.k_name, '/')) != NULL)
                *s = '!';
                        
-       list_add(&rdev->same_set, &mddev->disks);
        rdev->mddev = mddev;
        printk(KERN_INFO "md: bind<%s>\n", b);
 
        rdev->kobj.parent = &mddev->kobj;
-       kobject_add(&rdev->kobj);
+       if ((err = kobject_add(&rdev->kobj)))
+               goto fail;
 
        if (rdev->bdev->bd_part)
                ko = &rdev->bdev->bd_part->kobj;
        else
                ko = &rdev->bdev->bd_disk->kobj;
-       sysfs_create_link(&rdev->kobj, ko, "block");
+       if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
+               kobject_del(&rdev->kobj);
+               goto fail;
+       }
+       list_add(&rdev->same_set, &mddev->disks);
        bd_claim_by_disk(rdev->bdev, rdev, mddev->gendisk);
        return 0;
+
+ fail:
+       printk(KERN_WARNING "md: failed to register dev-%s for %s\n",
+              b, mdname(mddev));
+       return err;
+}
+
+static void delayed_delete(struct work_struct *ws)
+{
+       mdk_rdev_t *rdev = container_of(ws, mdk_rdev_t, del_work);
+       kobject_del(&rdev->kobj);
 }
 
 static void unbind_rdev_from_array(mdk_rdev_t * rdev)
@@ -1399,7 +1440,12 @@ static void unbind_rdev_from_array(mdk_rdev_t * rdev)
        printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
        rdev->mddev = NULL;
        sysfs_remove_link(&rdev->kobj, "block");
-       kobject_del(&rdev->kobj);
+
+       /* We need to delay this, otherwise we can deadlock when
+        * writing to 'remove' to "dev/state"
+        */
+       INIT_WORK(&rdev->del_work, delayed_delete);
+       schedule_work(&rdev->del_work);
 }
 
 /*
@@ -1633,7 +1679,8 @@ repeat:
         * and 'events' is odd, we can roll back to the previous clean state */
        if (nospares
            && (mddev->in_sync && mddev->recovery_cp == MaxSector)
-           && (mddev->events & 1))
+           && (mddev->events & 1)
+           && mddev->events != 1)
                mddev->events--;
        else {
                /* otherwise we have to go forward and ... */
@@ -1792,7 +1839,8 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                else {
                        mddev_t *mddev = rdev->mddev;
                        kick_rdev_from_array(rdev);
-                       md_update_sb(mddev, 1);
+                       if (mddev->pers)
+                               md_update_sb(mddev, 1);
                        md_new_event(mddev);
                        err = 0;
                }
@@ -2004,6 +2052,7 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
 
        rdev->desc_nr = -1;
        rdev->saved_raid_disk = -1;
+       rdev->raid_disk = -1;
        rdev->flags = 0;
        rdev->data_offset = 0;
        rdev->sb_events = 0;
@@ -2098,6 +2147,9 @@ static void analyze_sbs(mddev_t * mddev)
                        rdev->desc_nr = i++;
                        rdev->raid_disk = rdev->desc_nr;
                        set_bit(In_sync, &rdev->flags);
+               } else if (rdev->raid_disk >= mddev->raid_disks) {
+                       rdev->raid_disk = -1;
+                       clear_bit(In_sync, &rdev->flags);
                }
        }
 
@@ -2199,6 +2251,10 @@ static ssize_t
 layout_show(mddev_t *mddev, char *page)
 {
        /* just a number, not meaningful for all levels */
+       if (mddev->reshape_position != MaxSector &&
+           mddev->layout != mddev->new_layout)
+               return sprintf(page, "%d (%d)\n",
+                              mddev->new_layout, mddev->layout);
        return sprintf(page, "%d\n", mddev->layout);
 }
 
@@ -2207,13 +2263,16 @@ layout_store(mddev_t *mddev, const char *buf, size_t len)
 {
        char *e;
        unsigned long n = simple_strtoul(buf, &e, 10);
-       if (mddev->pers)
-               return -EBUSY;
 
        if (!*buf || (*e && *e != '\n'))
                return -EINVAL;
 
-       mddev->layout = n;
+       if (mddev->pers)
+               return -EBUSY;
+       if (mddev->reshape_position != MaxSector)
+               mddev->new_layout = n;
+       else
+               mddev->layout = n;
        return len;
 }
 static struct md_sysfs_entry md_layout =
@@ -2225,6 +2284,10 @@ raid_disks_show(mddev_t *mddev, char *page)
 {
        if (mddev->raid_disks == 0)
                return 0;
+       if (mddev->reshape_position != MaxSector &&
+           mddev->delta_disks != 0)
+               return sprintf(page, "%d (%d)\n", mddev->raid_disks,
+                              mddev->raid_disks - mddev->delta_disks);
        return sprintf(page, "%d\n", mddev->raid_disks);
 }
 
@@ -2233,7 +2296,6 @@ static int update_raid_disks(mddev_t *mddev, int raid_disks);
 static ssize_t
 raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
 {
-       /* can only set raid_disks if array is not yet active */
        char *e;
        int rv = 0;
        unsigned long n = simple_strtoul(buf, &e, 10);
@@ -2243,7 +2305,11 @@ raid_disks_store(mddev_t *mddev, const char *buf, size_t len)
 
        if (mddev->pers)
                rv = update_raid_disks(mddev, n);
-       else
+       else if (mddev->reshape_position != MaxSector) {
+               int olddisks = mddev->raid_disks - mddev->delta_disks;
+               mddev->delta_disks = n - olddisks;
+               mddev->raid_disks = n;
+       } else
                mddev->raid_disks = n;
        return rv ? rv : len;
 }
@@ -2253,6 +2319,10 @@ __ATTR(raid_disks, S_IRUGO|S_IWUSR, raid_disks_show, raid_disks_store);
 static ssize_t
 chunk_size_show(mddev_t *mddev, char *page)
 {
+       if (mddev->reshape_position != MaxSector &&
+           mddev->chunk_size != mddev->new_chunk)
+               return sprintf(page, "%d (%d)\n", mddev->new_chunk,
+                              mddev->chunk_size);
        return sprintf(page, "%d\n", mddev->chunk_size);
 }
 
@@ -2263,12 +2333,15 @@ chunk_size_store(mddev_t *mddev, const char *buf, size_t len)
        char *e;
        unsigned long n = simple_strtoul(buf, &e, 10);
 
-       if (mddev->pers)
-               return -EBUSY;
        if (!*buf || (*e && *e != '\n'))
                return -EINVAL;
 
-       mddev->chunk_size = n;
+       if (mddev->pers)
+               return -EBUSY;
+       else if (mddev->reshape_position != MaxSector)
+               mddev->new_chunk = n;
+       else
+               mddev->chunk_size = n;
        return len;
 }
 static struct md_sysfs_entry md_chunk_size =
@@ -2631,10 +2704,9 @@ metadata_store(mddev_t *mddev, const char *buf, size_t len)
                return -EINVAL;
        buf = e+1;
        minor = simple_strtoul(buf, &e, 10);
-       if (e==buf || *e != '\n')
+       if (e==buf || (*e && *e != '\n') )
                return -EINVAL;
-       if (major >= sizeof(super_types)/sizeof(super_types[0]) ||
-           super_types[major].name == NULL)
+       if (major >= ARRAY_SIZE(super_types) || super_types[major].name == NULL)
                return -ENOENT;
        mddev->major_version = major;
        mddev->minor_version = minor;
@@ -2855,6 +2927,37 @@ suspend_hi_store(mddev_t *mddev, const char *buf, size_t len)
 static struct md_sysfs_entry md_suspend_hi =
 __ATTR(suspend_hi, S_IRUGO|S_IWUSR, suspend_hi_show, suspend_hi_store);
 
+static ssize_t
+reshape_position_show(mddev_t *mddev, char *page)
+{
+       if (mddev->reshape_position != MaxSector)
+               return sprintf(page, "%llu\n",
+                              (unsigned long long)mddev->reshape_position);
+       strcpy(page, "none\n");
+       return 5;
+}
+
+static ssize_t
+reshape_position_store(mddev_t *mddev, const char *buf, size_t len)
+{
+       char *e;
+       unsigned long long new = simple_strtoull(buf, &e, 10);
+       if (mddev->pers)
+               return -EBUSY;
+       if (buf == e || (*e && *e != '\n'))
+               return -EINVAL;
+       mddev->reshape_position = new;
+       mddev->delta_disks = 0;
+       mddev->new_level = mddev->level;
+       mddev->new_layout = mddev->layout;
+       mddev->new_chunk = mddev->chunk_size;
+       return len;
+}
+
+static struct md_sysfs_entry md_reshape_position =
+__ATTR(reshape_position, S_IRUGO|S_IWUSR, reshape_position_show,
+       reshape_position_store);
+
 
 static struct attribute *md_default_attrs[] = {
        &md_level.attr,
@@ -2867,6 +2970,7 @@ static struct attribute *md_default_attrs[] = {
        &md_new_device.attr,
        &md_safe_delay.attr,
        &md_array_state.attr,
+       &md_reshape_position.attr,
        NULL,
 };
 
@@ -2983,7 +3087,9 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
        mddev->kobj.k_name = NULL;
        snprintf(mddev->kobj.name, KOBJ_NAME_LEN, "%s", "md");
        mddev->kobj.ktype = &md_ktype;
-       kobject_register(&mddev->kobj);
+       if (kobject_register(&mddev->kobj))
+               printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
+                      disk->disk_name);
        return NULL;
 }
 
@@ -3074,7 +3180,7 @@ static int do_md_run(mddev_t * mddev)
                if (test_bit(Faulty, &rdev->flags))
                        continue;
                sync_blockdev(rdev->bdev);
-               invalidate_bdev(rdev->bdev, 0);
+               invalidate_bdev(rdev->bdev);
        }
 
        md_probe(mddev->unit, NULL, NULL);
@@ -3107,6 +3213,36 @@ static int do_md_run(mddev_t * mddev)
                return -EINVAL;
        }
 
+       if (pers->sync_request) {
+               /* Warn if this is a potentially silly
+                * configuration.
+                */
+               char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
+               mdk_rdev_t *rdev2;
+               struct list_head *tmp2;
+               int warned = 0;
+               ITERATE_RDEV(mddev, rdev, tmp) {
+                       ITERATE_RDEV(mddev, rdev2, tmp2) {
+                               if (rdev < rdev2 &&
+                                   rdev->bdev->bd_contains ==
+                                   rdev2->bdev->bd_contains) {
+                                       printk(KERN_WARNING
+                                              "%s: WARNING: %s appears to be"
+                                              " on the same physical disk as"
+                                              " %s.\n",
+                                              mdname(mddev),
+                                              bdevname(rdev->bdev,b),
+                                              bdevname(rdev2->bdev,b2));
+                                       warned = 1;
+                               }
+                       }
+               }
+               if (warned)
+                       printk(KERN_WARNING
+                              "True protection against single-disk"
+                              " failure might be compromised.\n");
+       }
+
        mddev->recovery = 0;
        mddev->resync_max_sectors = mddev->size << 1; /* may be over-ridden by personality */
        mddev->barriers_work = 1;
@@ -3131,9 +3267,12 @@ static int do_md_run(mddev_t * mddev)
                bitmap_destroy(mddev);
                return err;
        }
-       if (mddev->pers->sync_request)
-               sysfs_create_group(&mddev->kobj, &md_redundancy_group);
-       else if (mddev->ro == 2) /* auto-readonly not meaningful */
+       if (mddev->pers->sync_request) {
+               if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
+                       printk(KERN_WARNING
+                              "md: cannot register extra attributes for %s\n",
+                              mdname(mddev));
+       } else if (mddev->ro == 2) /* auto-readonly not meaningful */
                mddev->ro = 0;
 
        atomic_set(&mddev->writes_pending,0);
@@ -3147,7 +3286,9 @@ static int do_md_run(mddev_t * mddev)
                if (rdev->raid_disk >= 0) {
                        char nm[20];
                        sprintf(nm, "rd%d", rdev->raid_disk);
-                       sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
+                       if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
+                               printk("md: cannot register %s for %s\n",
+                                      nm, mdname(mddev));
                }
        
        set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -3309,11 +3450,19 @@ static int do_md_stop(mddev_t * mddev, int mode)
                                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->issue_flush_fn = NULL;
+                       mddev->queue->backing_dev_info.congested_fn = NULL;
                        if (mddev->pers->sync_request)
                                sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
 
                        module_put(mddev->pers->owner);
                        mddev->pers = NULL;
+
+                       set_capacity(disk, 0);
+                       mddev->changed = 1;
+
                        if (mddev->ro)
                                mddev->ro = 0;
                }
@@ -3333,7 +3482,7 @@ static int do_md_stop(mddev_t * mddev, int mode)
        if (mode == 0) {
                mdk_rdev_t *rdev;
                struct list_head *tmp;
-               struct gendisk *disk;
+
                printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
 
                bitmap_destroy(mddev);
@@ -3351,17 +3500,17 @@ static int do_md_stop(mddev_t * mddev, int mode)
                                sysfs_remove_link(&mddev->kobj, nm);
                        }
 
+               /* make sure all delayed_delete calls have finished */
+               flush_scheduled_work();
+
                export_array(mddev);
 
                mddev->array_size = 0;
                mddev->size = 0;
                mddev->raid_disks = 0;
                mddev->recovery_cp = 0;
+               mddev->reshape_position = MaxSector;
 
-               disk = mddev->gendisk;
-               if (disk)
-                       set_capacity(disk, 0);
-               mddev->changed = 1;
        } else if (mddev->pers)
                printk(KERN_INFO "md: %s switched to read-only mode.\n",
                        mdname(mddev));
@@ -3371,6 +3520,7 @@ out:
        return err;
 }
 
+#ifndef MODULE
 static void autorun_array(mddev_t *mddev)
 {
        mdk_rdev_t *rdev;
@@ -3485,6 +3635,7 @@ static void autorun_devices(int part)
        }
        printk(KERN_INFO "md: ... autorun DONE.\n");
 }
+#endif /* !MODULE */
 
 static int get_version(void __user * arg)
 {
@@ -3560,6 +3711,8 @@ static int get_bitmap_file(mddev_t * mddev, void __user * arg)
        char *ptr, *buf = NULL;
        int err = -ENOMEM;
 
+       md_allow_write(mddev);
+
        file = kmalloc(sizeof(*file), GFP_KERNEL);
        if (!file)
                goto out;
@@ -3722,6 +3875,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
                if (err)
                        export_rdev(rdev);
 
+               md_update_sb(mddev, 1);
                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                md_wakeup_thread(mddev->thread);
                return err;
@@ -3966,7 +4120,7 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
        if (info->raid_disks == 0) {
                /* just setting version number for superblock loading */
                if (info->major_version < 0 ||
-                   info->major_version >= sizeof(super_types)/sizeof(super_types[0]) ||
+                   info->major_version >= ARRAY_SIZE(super_types) ||
                    super_types[info->major_version].name == NULL) {
                        /* maybe try to auto-load a module? */
                        printk(KERN_INFO 
@@ -3977,6 +4131,7 @@ static int set_array_info(mddev_t * mddev, mdu_array_info_t *info)
                mddev->major_version = info->major_version;
                mddev->minor_version = info->minor_version;
                mddev->patch_version = info->patch_version;
+               mddev->persistent = !info->not_persistent;
                return 0;
        }
        mddev->major_version = MD_MAJOR_VERSION;
@@ -4301,9 +4456,10 @@ static int md_ioctl(struct inode *inode, struct file *file,
         * Commands querying/configuring an existing array:
         */
        /* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
-        * RUN_ARRAY, and SET_BITMAP_FILE are allowed */
+        * RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
        if (!mddev->raid_disks && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
-                       && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE) {
+                       && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
+                       && cmd != GET_BITMAP_FILE) {
                err = -ENODEV;
                goto abort_unlock;
        }
@@ -4423,7 +4579,7 @@ static int md_open(struct inode *inode, struct file *file)
        mddev_t *mddev = inode->i_bdev->bd_disk->private_data;
        int err;
 
-       if ((err = mddev_lock(mddev)))
+       if ((err = mutex_lock_interruptible_nested(&mddev->reconfig_mutex, 1)))
                goto out;
 
        err = 0;
@@ -4486,7 +4642,6 @@ static int md_thread(void * arg)
         * many dirty RAID5 blocks.
         */
 
-       current->flags |= PF_NOFREEZE;
        allow_signal(SIGKILL);
        while (!kthread_should_stop()) {
 
@@ -4846,8 +5001,8 @@ static int md_seq_show(struct seq_file *seq, void *v)
                                chunk_kb ? "KB" : "B");
                        if (bitmap->file) {
                                seq_printf(seq, ", file: ");
-                               seq_path(seq, bitmap->file->f_vfsmnt,
-                                        bitmap->file->f_dentry," \t\n");
+                               seq_path(seq, bitmap->file->f_path.mnt,
+                                        bitmap->file->f_path.dentry," \t\n");
                        }
 
                        seq_printf(seq, "\n");
@@ -4886,15 +5041,6 @@ static int md_seq_open(struct inode *inode, struct file *file)
        return error;
 }
 
-static int md_seq_release(struct inode *inode, struct file *file)
-{
-       struct seq_file *m = file->private_data;
-       struct mdstat_info *mi = m->private;
-       m->private = NULL;
-       kfree(mi);
-       return seq_release(inode, file);
-}
-
 static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
 {
        struct seq_file *m = filp->private_data;
@@ -4911,12 +5057,12 @@ static unsigned int mdstat_poll(struct file *filp, poll_table *wait)
        return mask;
 }
 
-static struct file_operations md_seq_fops = {
+static const struct file_operations md_seq_fops = {
        .owner          = THIS_MODULE,
        .open           = md_seq_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
-       .release        = md_seq_release,
+       .release        = seq_release_private,
        .poll           = mdstat_poll,
 };
 
@@ -4964,7 +5110,7 @@ static int is_mddev_idle(mddev_t *mddev)
                 *
                 * Note: the following is an unsigned comparison.
                 */
-               if ((curr_events - rdev->last_events + 4096) > 8192) {
+               if ((long)curr_events - (long)rdev->last_events > 4096) {
                        rdev->last_events = curr_events;
                        idle = 0;
                }
@@ -5025,6 +5171,33 @@ void md_write_end(mddev_t *mddev)
        }
 }
 
+/* md_allow_write(mddev)
+ * Calling this ensures that the array is marked 'active' so that writes
+ * may proceed without blocking.  It is important to call this before
+ * attempting a GFP_KERNEL allocation while holding the mddev lock.
+ * Must be called with mddev_lock held.
+ */
+void md_allow_write(mddev_t *mddev)
+{
+       if (!mddev->pers)
+               return;
+       if (mddev->ro)
+               return;
+
+       spin_lock_irq(&mddev->write_lock);
+       if (mddev->in_sync) {
+               mddev->in_sync = 0;
+               set_bit(MD_CHANGE_CLEAN, &mddev->flags);
+               if (mddev->safemode_delay &&
+                   mddev->safemode == 0)
+                       mddev->safemode = 1;
+               spin_unlock_irq(&mddev->write_lock);
+               md_update_sb(mddev, 0);
+       } else
+               spin_unlock_irq(&mddev->write_lock);
+}
+EXPORT_SYMBOL_GPL(md_allow_write);
+
 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
 
 #define SYNC_MARKS     10
@@ -5273,7 +5446,6 @@ void md_do_sync(mddev_t *mddev)
        mddev->pers->sync_request(mddev, max_sectors, &skipped, 1);
 
        if (!test_bit(MD_RECOVERY_ERR, &mddev->recovery) &&
-           test_bit(MD_RECOVERY_SYNC, &mddev->recovery) &&
            !test_bit(MD_RECOVERY_CHECK, &mddev->recovery) &&
            mddev->curr_resync > 2) {
                if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
@@ -5297,6 +5469,7 @@ void md_do_sync(mddev_t *mddev)
                                        rdev->recovery_offset = mddev->curr_resync;
                }
        }
+       set_bit(MD_CHANGE_DEVS, &mddev->flags);
 
  skip:
        mddev->curr_resync = 0;
@@ -5307,6 +5480,48 @@ void md_do_sync(mddev_t *mddev)
 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;
+
+       ITERATE_RDEV(mddev,rdev,rtmp)
+               if (rdev->raid_disk >= 0 &&
+                   (test_bit(Faulty, &rdev->flags) ||
+                    ! test_bit(In_sync, &rdev->flags)) &&
+                   atomic_read(&rdev->nr_pending)==0) {
+                       if (mddev->pers->hot_remove_disk(
+                                   mddev, rdev->raid_disk)==0) {
+                               char nm[20];
+                               sprintf(nm,"rd%d", rdev->raid_disk);
+                               sysfs_remove_link(&mddev->kobj, nm);
+                               rdev->raid_disk = -1;
+                       }
+               }
+
+       if (mddev->degraded) {
+               ITERATE_RDEV(mddev,rdev,rtmp)
+                       if (rdev->raid_disk < 0
+                           && !test_bit(Faulty, &rdev->flags)) {
+                               rdev->recovery_offset = 0;
+                               if (mddev->pers->hot_add_disk(mddev,rdev)) {
+                                       char nm[20];
+                                       sprintf(nm, "rd%d", rdev->raid_disk);
+                                       if (sysfs_create_link(&mddev->kobj,
+                                                             &rdev->kobj, nm))
+                                               printk(KERN_WARNING
+                                                      "md: cannot register "
+                                                      "%s for %s\n",
+                                                      nm, mdname(mddev));
+                                       spares++;
+                                       md_new_event(mddev);
+                               } else
+                                       break;
+                       }
+       }
+       return spares;
+}
 /*
  * This routine is regularly called by all per-raid-array threads to
  * deal with generic issues like resync and super-block update.
@@ -5361,7 +5576,7 @@ void md_check_recovery(mddev_t *mddev)
                return;
 
        if (mddev_trylock(mddev)) {
-               int spares =0;
+               int spares = 0;
 
                spin_lock_irq(&mddev->write_lock);
                if (mddev->safemode && !atomic_read(&mddev->writes_pending) &&
@@ -5424,35 +5639,13 @@ void md_check_recovery(mddev_t *mddev)
                 * Spare are also removed and re-added, to allow
                 * the personality to fail the re-add.
                 */
-               ITERATE_RDEV(mddev,rdev,rtmp)
-                       if (rdev->raid_disk >= 0 &&
-                           (test_bit(Faulty, &rdev->flags) || ! test_bit(In_sync, &rdev->flags)) &&
-                           atomic_read(&rdev->nr_pending)==0) {
-                               if (mddev->pers->hot_remove_disk(mddev, rdev->raid_disk)==0) {
-                                       char nm[20];
-                                       sprintf(nm,"rd%d", rdev->raid_disk);
-                                       sysfs_remove_link(&mddev->kobj, nm);
-                                       rdev->raid_disk = -1;
-                               }
-                       }
 
-               if (mddev->degraded) {
-                       ITERATE_RDEV(mddev,rdev,rtmp)
-                               if (rdev->raid_disk < 0
-                                   && !test_bit(Faulty, &rdev->flags)) {
-                                       rdev->recovery_offset = 0;
-                                       if (mddev->pers->hot_add_disk(mddev,rdev)) {
-                                               char nm[20];
-                                               sprintf(nm, "rd%d", rdev->raid_disk);
-                                               sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
-                                               spares++;
-                                               md_new_event(mddev);
-                                       } else
-                                               break;
-                               }
-               }
-
-               if (spares) {
+               if (mddev->reshape_position != MaxSector) {
+                       if (mddev->pers->check_reshape(mddev) != 0)
+                               /* Cannot proceed */
+                               goto unlock;
+                       set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery);
+               } else if ((spares = remove_and_add_spares(mddev))) {
                        clear_bit(MD_RECOVERY_SYNC, &mddev->recovery);
                        clear_bit(MD_RECOVERY_CHECK, &mddev->recovery);
                } else if (mddev->recovery_cp < MaxSector) {
@@ -5545,7 +5738,7 @@ static int __init md_init(void)
                            md_probe, NULL, NULL);
 
        register_reboot_notifier(&md_notifier);
-       raid_table_header = register_sysctl_table(raid_root_table, 1);
+       raid_table_header = register_sysctl_table(raid_root_table);
 
        md_geninit();
        return (0);
@@ -5593,7 +5786,7 @@ static void autostart_arrays(int part)
        autorun_devices(part);
 }
 
-#endif
+#endif /* !MODULE */
 
 static __exit void md_exit(void)
 {
@@ -5620,7 +5813,7 @@ static __exit void md_exit(void)
        }
 }
 
-module_init(md_init)
+subsys_initcall(md_init);
 module_exit(md_exit)
 
 static int get_ro(char *buffer, struct kernel_param *kp)