8 files changed, 219 insertions, 95 deletions

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index e30b490055aa..4d8d90b4fe78 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -154,17 +154,6 @@ config MD_RAID456
 
           If unsure, say Y.
 
-config MULTICORE_RAID456
-        bool "RAID-4/RAID-5/RAID-6 Multicore processing (EXPERIMENTAL)"
-        depends on MD_RAID456
-        depends on SMP
-        depends on EXPERIMENTAL
-        ---help---
-          Enable the raid456 module to dispatch per-stripe raid operations to a
-          thread pool.
-
-          If unsure, say N.
-
 config MD_MULTIPATH
         tristate "Multipath I/O support"
         depends on BLK_DEV_MD
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 9a01d1e4c783..311e3d35b272 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -91,15 +91,44 @@ static struct raid_type {
         {"raid6_nc", "RAID6 (N continue)",              2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
 };
 
+static char *raid10_md_layout_to_format(int layout)
+{
+        /*
+         * Bit 16 and 17 stand for "offset" and "use_far_sets"
+         * Refer to MD's raid10.c for details
+         */
+        if ((layout & 0x10000) && (layout & 0x20000))
+                return "offset";
+
+        if ((layout & 0xFF) > 1)
+                return "near";
+
+        return "far";
+}
+
 static unsigned raid10_md_layout_to_copies(int layout)
 {
-        return layout & 0xFF;
+        if ((layout & 0xFF) > 1)
+                return layout & 0xFF;
+        return (layout >> 8) & 0xFF;
 }
 
 static int raid10_format_to_md_layout(char *format, unsigned copies)
 {
-        /* 1 "far" copy, and 'copies' "near" copies */
-        return (1 << 8) | (copies & 0xFF);
+        unsigned n = 1, f = 1;
+
+        if (!strcmp("near", format))
+                n = copies;
+        else
+                f = copies;
+
+        if (!strcmp("offset", format))
+                return 0x30000 | (f << 8) | n;
+
+        if (!strcmp("far", format))
+                return 0x20000 | (f << 8) | n;
+
+        return (f << 8) | n;
 }
 
 static struct raid_type *get_raid_type(char *name)
@@ -352,6 +381,7 @@ static int validate_raid_redundancy(struct raid_set *rs)
 {
         unsigned i, rebuild_cnt = 0;
         unsigned rebuilds_per_group, copies, d;
+        unsigned group_size, last_group_start;
 
         for (i = 0; i < rs->md.raid_disks; i++)
                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
@@ -379,9 +409,6 @@ static int validate_raid_redundancy(struct raid_set *rs)
                  * as long as the failed devices occur in different mirror
                  * groups (i.e. different stripes).
                  *
-                 * Right now, we only allow for "near" copies.  When other
-                 * formats are added, we will have to check those too.
-                 *
                  * When checking "near" format, make sure no adjacent devices
                  * have failed beyond what can be handled.  In addition to the
                  * simple case where the number of devices is a multiple of the
@@ -391,14 +418,41 @@ static int validate_raid_redundancy(struct raid_set *rs)
                  *          A    A    B    B    C
                  *          C    D    D    E    E
                  */
-                for (i = 0; i < rs->md.raid_disks * copies; i++) {
-                        if (!(i % copies))
+                if (!strcmp("near", raid10_md_layout_to_format(rs->md.layout))) {
+                        for (i = 0; i < rs->md.raid_disks * copies; i++) {
+                                if (!(i % copies))
+                                        rebuilds_per_group = 0;
+                                d = i % rs->md.raid_disks;
+                                if ((!rs->dev[d].rdev.sb_page ||
+                                     !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
+                                    (++rebuilds_per_group >= copies))
+                                        goto too_many;
+                        }
+                        break;
+                }
+
+                /*
+                 * When checking "far" and "offset" formats, we need to ensure
+                 * that the device that holds its copy is not also dead or
+                 * being rebuilt.  (Note that "far" and "offset" formats only
+                 * support two copies right now.  These formats also only ever
+                 * use the 'use_far_sets' variant.)
+                 *
+                 * This check is somewhat complicated by the need to account
+                 * for arrays that are not a multiple of (far) copies.  This
+                 * results in the need to treat the last (potentially larger)
+                 * set differently.
+                 */
+                group_size = (rs->md.raid_disks / copies);
+                last_group_start = (rs->md.raid_disks / group_size) - 1;
+                last_group_start *= group_size;
+                for (i = 0; i < rs->md.raid_disks; i++) {
+                        if (!(i % copies) && !(i > last_group_start))
                                 rebuilds_per_group = 0;
-                        d = i % rs->md.raid_disks;
-                        if ((!rs->dev[d].rdev.sb_page ||
-                             !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
+                        if ((!rs->dev[i].rdev.sb_page ||
+                             !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
                             (++rebuilds_per_group >= copies))
-                                goto too_many;
+                                        goto too_many;
                 }
                 break;
         default:
@@ -433,7 +487,7 @@ too_many:
  *
  * RAID10-only options:
  *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
- *    [raid10_format <near>]            Layout algorithm.  (Default: near)
+ *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
  */
 static int parse_raid_params(struct raid_set *rs, char **argv,
                              unsigned num_raid_params)
@@ -520,7 +574,9 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
                                 rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
                                 return -EINVAL;
                         }
-                        if (strcmp("near", argv[i])) {
+                        if (strcmp("near", argv[i]) &&
+                            strcmp("far", argv[i]) &&
+                            strcmp("offset", argv[i])) {
                                 rs->ti->error = "Invalid 'raid10_format' value given";
                                 return -EINVAL;
                         }
@@ -644,6 +700,15 @@ static int parse_raid_params(struct raid_set *rs, char **argv,
                         return -EINVAL;
                 }
 
+                /*
+                 * If the format is not "near", we only support
+                 * two copies at the moment.
+                 */
+                if (strcmp("near", raid10_format) && (raid10_copies > 2)) {
+                        rs->ti->error = "Too many copies for given RAID10 format.";
+                        return -EINVAL;
+                }
+
                 /* (Len * #mirrors) / #devices */
                 sectors_per_dev = rs->ti->len * raid10_copies;
                 sector_div(sectors_per_dev, rs->md.raid_disks);
@@ -854,17 +919,30 @@ static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
         /*
          * Reshaping is not currently allowed
          */
-        if ((le32_to_cpu(sb->level) != mddev->level) ||
-            (le32_to_cpu(sb->layout) != mddev->layout) ||
-            (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
-                DMERR("Reshaping arrays not yet supported.");
+        if (le32_to_cpu(sb->level) != mddev->level) {
+                DMERR("Reshaping arrays not yet supported. (RAID level change)");
+                return -EINVAL;
+        }
+        if (le32_to_cpu(sb->layout) != mddev->layout) {
+                DMERR("Reshaping arrays not yet supported. (RAID layout change)");
+                DMERR("  0x%X vs 0x%X", le32_to_cpu(sb->layout), mddev->layout);
+                DMERR("  Old layout: %s w/ %d copies",
+                      raid10_md_layout_to_format(le32_to_cpu(sb->layout)),
+                      raid10_md_layout_to_copies(le32_to_cpu(sb->layout)));
+                DMERR("  New layout: %s w/ %d copies",
+                      raid10_md_layout_to_format(mddev->layout),
+                      raid10_md_layout_to_copies(mddev->layout));
+                return -EINVAL;
+        }
+        if (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors) {
+                DMERR("Reshaping arrays not yet supported. (stripe sectors change)");
                 return -EINVAL;
         }
 
         /* We can only change the number of devices in RAID1 right now */
         if ((rs->raid_type->level != 1) &&
             (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
-                DMERR("Reshaping arrays not yet supported.");
+                DMERR("Reshaping arrays not yet supported. (device count change)");
                 return -EINVAL;
         }
 
@@ -1329,7 +1407,8 @@ static void raid_status(struct dm_target *ti, status_type_t type,
                                raid10_md_layout_to_copies(rs->md.layout));
 
                 if (rs->print_flags & DMPF_RAID10_FORMAT)
-                        DMEMIT(" raid10_format near");
+                        DMEMIT(" raid10_format %s",
+                               raid10_md_layout_to_format(rs->md.layout));
 
                 DMEMIT(" %d", rs->md.raid_disks);
                 for (i = 0; i < rs->md.raid_disks; i++) {
@@ -1418,6 +1497,10 @@ static struct target_type raid_target = {
 
 static int __init dm_raid_init(void)
 {
+        DMINFO("Loading target version %u.%u.%u",
+               raid_target.version[0],
+               raid_target.version[1],
+               raid_target.version[2]);
         return dm_register_target(&raid_target);
 }
 
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3db3d1b271f7..fcb878f88796 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -307,6 +307,10 @@ static void md_make_request(struct request_queue *q, struct bio *bio)
                 bio_io_error(bio);
                 return;
         }
+        if (mddev->ro == 1 && unlikely(rw == WRITE)) {
+                bio_endio(bio, bio_sectors(bio) == 0 ? 0 : -EROFS);
+                return;
+        }
         smp_rmb(); /* Ensure implications of  'active' are visible */
         rcu_read_lock();
         if (mddev->suspended) {
@@ -2994,6 +2998,9 @@ rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
                 } else if (!sectors)
                         sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
                                 rdev->data_offset;
+                if (!my_mddev->pers->resize)
+                        /* Cannot change size for RAID0 or Linear etc */
+                        return -EINVAL;
         }
         if (sectors < my_mddev->dev_sectors)
                 return -EINVAL; /* component must fit device */
@@ -6525,7 +6532,17 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
                         mddev->ro = 0;
                         sysfs_notify_dirent_safe(mddev->sysfs_state);
                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-                        md_wakeup_thread(mddev->thread);
+                        /* mddev_unlock will wake thread */
+                        /* If a device failed while we were read-only, we
+                         * need to make sure the metadata is updated now.
+                         */
+                        if (test_bit(MD_CHANGE_DEVS, &mddev->flags)) {
+                                mddev_unlock(mddev);
+                                wait_event(mddev->sb_wait,
+                                           !test_bit(MD_CHANGE_DEVS, &mddev->flags) &&
+                                           !test_bit(MD_CHANGE_PENDING, &mddev->flags));
+                                mddev_lock(mddev);
+                        }
                 } else {
                         err = -EROFS;
                         goto abort_unlock;
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 24b359717a7e..0505452de8d6 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -175,7 +175,13 @@ static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf)
                         rdev1->new_raid_disk = j;
                 }
 
-                if (j < 0 || j >= mddev->raid_disks) {
+                if (j < 0) {
+                        printk(KERN_ERR
+                               "md/raid0:%s: remove inactive devices before converting to RAID0\n",
+                               mdname(mddev));
+                        goto abort;
+                }
+                if (j >= mddev->raid_disks) {
                         printk(KERN_ERR "md/raid0:%s: bad disk number %d - "
                                "aborting!\n", mdname(mddev), j);
                         goto abort;
@@ -289,7 +295,7 @@ abort:
         kfree(conf->strip_zone);
         kfree(conf->devlist);
         kfree(conf);
-        *private_conf = NULL;
+        *private_conf = ERR_PTR(err);
         return err;
 }
 
@@ -411,7 +417,8 @@ static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks
                   "%s does not support generic reshape\n", __func__);
 
         rdev_for_each(rdev, mddev)
-                array_sectors += rdev->sectors;
+                array_sectors += (rdev->sectors &
+                                  ~(sector_t)(mddev->chunk_sectors-1));
 
         return array_sectors;
 }
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index d5bddfc4010e..fd86b372692d 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -967,6 +967,7 @@ static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule)
                 bio_list_merge(&conf->pending_bio_list, &plug->pending);
                 conf->pending_count += plug->pending_cnt;
                 spin_unlock_irq(&conf->device_lock);
+                wake_up(&conf->wait_barrier);
                 md_wakeup_thread(mddev->thread);
                 kfree(plug);
                 return;
@@ -1000,6 +1001,7 @@ static void make_request(struct mddev *mddev, struct bio * bio)
         const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
         const unsigned long do_discard = (bio->bi_rw
                                           & (REQ_DISCARD | REQ_SECURE));
+        const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
         struct md_rdev *blocked_rdev;
         struct blk_plug_cb *cb;
         struct raid1_plug_cb *plug = NULL;
@@ -1301,7 +1303,8 @@ read_again:
                                    conf->mirrors[i].rdev->data_offset);
                 mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
                 mbio->bi_end_io = raid1_end_write_request;
-                mbio->bi_rw = WRITE | do_flush_fua | do_sync | do_discard;
+                mbio->bi_rw =
+                        WRITE | do_flush_fua | do_sync | do_discard | do_same;
                 mbio->bi_private = r1_bio;
 
                 atomic_inc(&r1_bio->remaining);
@@ -2818,6 +2821,9 @@ static int run(struct mddev *mddev)
         if (IS_ERR(conf))
                 return PTR_ERR(conf);
 
+        if (mddev->queue)
+                blk_queue_max_write_same_sectors(mddev->queue,
+                                                 mddev->chunk_sectors);
         rdev_for_each(rdev, mddev) {
                 if (!mddev->gendisk)
                         continue;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 64d48249c03b..77b562d18a90 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -38,21 +38,36 @@
  *    near_copies (stored in low byte of layout)
  *    far_copies (stored in second byte of layout)
  *    far_offset (stored in bit 16 of layout )
+ *    use_far_sets (stored in bit 17 of layout )
  *
- * The data to be stored is divided into chunks using chunksize.
- * Each device is divided into far_copies sections.
- * In each section, chunks are laid out in a style similar to raid0, but
- * near_copies copies of each chunk is stored (each on a different drive).
- * The starting device for each section is offset near_copies from the starting
- * device of the previous section.
- * Thus they are (near_copies*far_copies) of each chunk, and each is on a different
- * drive.
- * near_copies and far_copies must be at least one, and their product is at most
- * raid_disks.
+ * The data to be stored is divided into chunks using chunksize.  Each device
+ * is divided into far_copies sections.   In each section, chunks are laid out
+ * in a style similar to raid0, but near_copies copies of each chunk is stored
+ * (each on a different drive).  The starting device for each section is offset
+ * near_copies from the starting device of the previous section.  Thus there
+ * are (near_copies * far_copies) of each chunk, and each is on a different
+ * drive.  near_copies and far_copies must be at least one, and their product
+ * is at most raid_disks.
  *
  * If far_offset is true, then the far_copies are handled a bit differently.
- * The copies are still in different stripes, but instead of be very far apart
- * on disk, there are adjacent stripes.
+ * The copies are still in different stripes, but instead of being very far
+ * apart on disk, there are adjacent stripes.
+ *
+ * The far and offset algorithms are handled slightly differently if
+ * 'use_far_sets' is true.  In this case, the array's devices are grouped into
+ * sets that are (near_copies * far_copies) in size.  The far copied stripes
+ * are still shifted by 'near_copies' devices, but this shifting stays confined
+ * to the set rather than the entire array.  This is done to improve the number
+ * of device combinations that can fail without causing the array to fail.
+ * Example 'far' algorithm w/o 'use_far_sets' (each letter represents a chunk
+ * on a device):
+ *    A B C D    A B C D E
+ *      ...         ...
+ *    D A B C    E A B C D
+ * Example 'far' algorithm w/ 'use_far_sets' enabled (sets illustrated w/ []'s):
+ *    [A B] [C D]    [A B] [C D E]
+ *    |...| |...|    |...| | ... |
+ *    [B A] [D C]    [B A] [E C D]
  */
 
 /*
@@ -535,6 +550,13 @@ static void __raid10_find_phys(struct geom *geo, struct r10bio *r10bio)
         sector_t stripe;
         int dev;
         int slot = 0;
+        int last_far_set_start, last_far_set_size;
+
+        last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
+        last_far_set_start *= geo->far_set_size;
+
+        last_far_set_size = geo->far_set_size;
+        last_far_set_size += (geo->raid_disks % geo->far_set_size);
 
         /* now calculate first sector/dev */
         chunk = r10bio->sector >> geo->chunk_shift;
@@ -551,15 +573,25 @@ static void __raid10_find_phys(struct geom *geo, struct r10bio *r10bio)
         /* and calculate all the others */
         for (n = 0; n < geo->near_copies; n++) {
                 int d = dev;
+                int set;
                 sector_t s = sector;
-                r10bio->devs[slot].addr = sector;
                 r10bio->devs[slot].devnum = d;
+                r10bio->devs[slot].addr = s;
                 slot++;
 
                 for (f = 1; f < geo->far_copies; f++) {
+                        set = d / geo->far_set_size;
                         d += geo->near_copies;
-                        if (d >= geo->raid_disks)
-                                d -= geo->raid_disks;
+
+                        if ((geo->raid_disks % geo->far_set_size) &&
+                            (d > last_far_set_start)) {
+                                d -= last_far_set_start;
+                                d %= last_far_set_size;
+                                d += last_far_set_start;
+                        } else {
+                                d %= geo->far_set_size;
+                                d += geo->far_set_size * set;
+                        }
                         s += geo->stride;
                         r10bio->devs[slot].devnum = d;
                         r10bio->devs[slot].addr = s;
@@ -595,6 +627,20 @@ static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
          * or recovery, so reshape isn't happening
          */
         struct geom *geo = &conf->geo;
+        int far_set_start = (dev / geo->far_set_size) * geo->far_set_size;
+        int far_set_size = geo->far_set_size;
+        int last_far_set_start;
+
+        if (geo->raid_disks % geo->far_set_size) {
+                last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1;
+                last_far_set_start *= geo->far_set_size;
+
+                if (dev >= last_far_set_start) {
+                        far_set_size = geo->far_set_size;
+                        far_set_size += (geo->raid_disks % geo->far_set_size);
+                        far_set_start = last_far_set_start;
+                }
+        }
 
         offset = sector & geo->chunk_mask;
         if (geo->far_offset) {
@@ -602,13 +648,13 @@ static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev)
                 chunk = sector >> geo->chunk_shift;
                 fc = sector_div(chunk, geo->far_copies);
                 dev -= fc * geo->near_copies;
-                if (dev < 0)
-                        dev += geo->raid_disks;
+                if (dev < far_set_start)
+                        dev += far_set_size;
         } else {
                 while (sector >= geo->stride) {
                         sector -= geo->stride;
-                        if (dev < geo->near_copies)
-                                dev += geo->raid_disks - geo->near_copies;
+                        if (dev < (geo->near_copies + far_set_start))
+                                dev += far_set_size - geo->near_copies;
                         else
                                 dev -= geo->near_copies;
                 }
@@ -1073,6 +1119,7 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule)
                 bio_list_merge(&conf->pending_bio_list, &plug->pending);
                 conf->pending_count += plug->pending_cnt;
                 spin_unlock_irq(&conf->device_lock);
+                wake_up(&conf->wait_barrier);
                 md_wakeup_thread(mddev->thread);
                 kfree(plug);
                 return;
@@ -1105,6 +1152,7 @@ static void make_request(struct mddev *mddev, struct bio * bio)
         const unsigned long do_fua = (bio->bi_rw & REQ_FUA);
         const unsigned long do_discard = (bio->bi_rw
                                           & (REQ_DISCARD | REQ_SECURE));
+        const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME);
         unsigned long flags;
         struct md_rdev *blocked_rdev;
         struct blk_plug_cb *cb;
@@ -1460,7 +1508,8 @@ retry_write:
                                                               rdev));
                         mbio->bi_bdev = rdev->bdev;
                         mbio->bi_end_io = raid10_end_write_request;
-                        mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
+                        mbio->bi_rw =
+                                WRITE | do_sync | do_fua | do_discard | do_same;
                         mbio->bi_private = r10_bio;
 
                         atomic_inc(&r10_bio->remaining);
@@ -1502,7 +1551,8 @@ retry_write:
                                                    r10_bio, rdev));
                         mbio->bi_bdev = rdev->bdev;
                         mbio->bi_end_io = raid10_end_write_request;
-                        mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
+                        mbio->bi_rw =
+                                WRITE | do_sync | do_fua | do_discard | do_same;
                         mbio->bi_private = r10_bio;
 
                         atomic_inc(&r10_bio->remaining);
@@ -3436,7 +3486,7 @@ static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new)
                 disks = mddev->raid_disks + mddev->delta_disks;
                 break;
         }
-        if (layout >> 17)
+        if (layout >> 18)
                 return -1;
         if (chunk < (PAGE_SIZE >> 9) ||
             !is_power_of_2(chunk))
@@ -3448,6 +3498,7 @@ static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new)
         geo->near_copies = nc;
         geo->far_copies = fc;
         geo->far_offset = fo;
+        geo->far_set_size = (layout & (1<<17)) ? disks / fc : disks;
         geo->chunk_mask = chunk - 1;
         geo->chunk_shift = ffz(~chunk);
         return nc*fc;
@@ -3569,6 +3620,8 @@ static int run(struct mddev *mddev)
         if (mddev->queue) {
                 blk_queue_max_discard_sectors(mddev->queue,
                                               mddev->chunk_sectors);
+                blk_queue_max_write_same_sectors(mddev->queue,
+                                                 mddev->chunk_sectors);
                 blk_queue_io_min(mddev->queue, chunk_size);
                 if (conf->geo.raid_disks % conf->geo.near_copies)
                         blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h
index 1054cf602345..157d69e83ff4 100644
--- a/drivers/md/raid10.h
+++ b/drivers/md/raid10.h
@@ -33,6 +33,11 @@ struct r10conf {
                                                * far_offset, in which case it is
                                                * 1 stripe.
                                                */
+                int             far_set_size; /* The number of devices in a set,
+                                               * where a 'set' are devices that
+                                               * contain far/offset copies of
+                                               * each other.
+                                               */
                 int             chunk_shift; /* shift from chunks to sectors */
                 sector_t        chunk_mask;
         } prev, geo;
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 5af2d2709081..3ee2912889e7 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1403,7 +1403,7 @@ static void ops_run_check_pq(struct stripe_head *sh, struct raid5_percpu *percpu
                            &sh->ops.zero_sum_result, percpu->spare_page, &submit);
 }
 
-static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
+static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
 {
         int overlap_clear = 0, i, disks = sh->disks;
         struct dma_async_tx_descriptor *tx = NULL;
@@ -1468,36 +1468,6 @@ static void __raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
         put_cpu();
 }
 
-#ifdef CONFIG_MULTICORE_RAID456
-static void async_run_ops(void *param, async_cookie_t cookie)
-{
-        struct stripe_head *sh = param;
-        unsigned long ops_request = sh->ops.request;
-
-        clear_bit_unlock(STRIPE_OPS_REQ_PENDING, &sh->state);
-        wake_up(&sh->ops.wait_for_ops);
-
-        __raid_run_ops(sh, ops_request);
-        release_stripe(sh);
-}
-
-static void raid_run_ops(struct stripe_head *sh, unsigned long ops_request)
-{
-        /* since handle_stripe can be called outside of raid5d context
-         * we need to ensure sh->ops.request is de-staged before another
-         * request arrives
-         */
-        wait_event(sh->ops.wait_for_ops,
-                   !test_and_set_bit_lock(STRIPE_OPS_REQ_PENDING, &sh->state));
-        sh->ops.request = ops_request;
-
-        atomic_inc(&sh->count);
-        async_schedule(async_run_ops, sh);
-}
-#else
-#define raid_run_ops __raid_run_ops
-#endif
-
 static int grow_one_stripe(struct r5conf *conf)
 {
         struct stripe_head *sh;
@@ -1506,9 +1476,6 @@ static int grow_one_stripe(struct r5conf *conf)
                 return 0;
 
         sh->raid_conf = conf;
-        #ifdef CONFIG_MULTICORE_RAID456
-        init_waitqueue_head(&sh->ops.wait_for_ops);
-        #endif
 
         spin_lock_init(&sh->stripe_lock);
 
@@ -1627,9 +1594,6 @@ static int resize_stripes(struct r5conf *conf, int newsize)
                         break;
 
                 nsh->raid_conf = conf;
-                #ifdef CONFIG_MULTICORE_RAID456
-                init_waitqueue_head(&nsh->ops.wait_for_ops);
-                #endif
                 spin_lock_init(&nsh->stripe_lock);
 
                 list_add(&nsh->lru, &newstripes);