md: add possibility to change data-offset for devices.

When reshaping we can avoid costly intermediate backup by
changing the 'start' address of the array on the device
(if there is enough room).

So as a first step, allow such a change to be requested
through sysfs, and recorded in v1.x metadata.

(As we didn't previous check that all 'pad' fields were zero,
 we need a new FEATURE flag for this.
 A (belatedly) check that all remaining 'pad' fields are
 zero to avoid a repeat of this)

The new data offset must be requested separately for each device.
This allows each to have a different change in the data offset.
This is not likely to be used often but as data_offset can be
set per-device, new_data_offset should be too.

This patch also removes the 'acknowledged' arg to rdev_set_badblocks as
it is never used and never will be.  At the same time we add a new
arg ('in_new') which is currently always zero but will be used more
soon.

When a reshape finishes we will need to update the data_offset
and rdev->sectors.  So provide an exported function to do that.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 1ea2e269a1f74f8bce066b63fd3ac1590c3261c9..5f06cf2f062b9490e9de6e76f1285036358eb7d7 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1033,12 +1033,17 @@ static unsigned int calc_sb_csum(mdp_super_t * sb)
 struct super_type  {
        char                *name;
        struct module       *owner;
-       int                 (*load_super)(struct md_rdev *rdev, struct md_rdev *refdev,
+       int                 (*load_super)(struct md_rdev *rdev,
+                                         struct md_rdev *refdev,
                                          int minor_version);
-       int                 (*validate_super)(struct mddev *mddev, struct md_rdev *rdev);
-       void                (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
+       int                 (*validate_super)(struct mddev *mddev,
+                                             struct md_rdev *rdev);
+       void                (*sync_super)(struct mddev *mddev,
+                                         struct md_rdev *rdev);
        unsigned long long  (*rdev_size_change)(struct md_rdev *rdev,
                                                sector_t num_sectors);
+       int                 (*allow_new_offset)(struct md_rdev *rdev,
+                                               unsigned long long new_offset);
 };
 
 /*
@@ -1110,6 +1115,7 @@ static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor
 
        rdev->preferred_minor = sb->md_minor;
        rdev->data_offset = 0;
+       rdev->new_data_offset = 0;
        rdev->sb_size = MD_SB_BYTES;
        rdev->badblocks.shift = -1;
 
@@ -1436,6 +1442,12 @@ super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
        return num_sectors;
 }
 
+static int
+super_90_allow_new_offset(struct md_rdev *rdev, unsigned long long new_offset)
+{
+       /* non-zero offset changes not possible with v0.90 */
+       return new_offset == 0;
+}
 
 /*
  * version 1 superblock
@@ -1471,6 +1483,7 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_
        struct mdp_superblock_1 *sb;
        int ret;
        sector_t sb_start;
+       sector_t sectors;
        char b[BDEVNAME_SIZE], b2[BDEVNAME_SIZE];
        int bmask;
 
@@ -1525,9 +1538,18 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_
                       bdevname(rdev->bdev,b));
                return -EINVAL;
        }
+       if (sb->pad0 ||
+           sb->pad3[0] ||
+           memcmp(sb->pad3, sb->pad3+1, sizeof(sb->pad3) - sizeof(sb->pad3[1])))
+               /* Some padding is non-zero, might be a new feature */
+               return -EINVAL;
 
        rdev->preferred_minor = 0xffff;
        rdev->data_offset = le64_to_cpu(sb->data_offset);
+       rdev->new_data_offset = rdev->data_offset;
+       if ((le32_to_cpu(sb->feature_map) & MD_FEATURE_RESHAPE_ACTIVE) &&
+           (le32_to_cpu(sb->feature_map) & MD_FEATURE_NEW_OFFSET))
+               rdev->new_data_offset += (s32)le32_to_cpu(sb->new_offset);
        atomic_set(&rdev->corrected_errors, le32_to_cpu(sb->cnt_corrected_read));
 
        rdev->sb_size = le32_to_cpu(sb->max_dev) * 2 + 256;
@@ -1538,6 +1560,9 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_
        if (minor_version
            && rdev->data_offset < sb_start + (rdev->sb_size/512))
                return -EINVAL;
+       if (minor_version
+           && rdev->new_data_offset < sb_start + (rdev->sb_size/512))
+               return -EINVAL;
 
        if (sb->level == cpu_to_le32(LEVEL_MULTIPATH))
                rdev->desc_nr = -1;
@@ -1609,16 +1634,14 @@ static int super_1_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor_
                else
                        ret = 0;
        }
-       if (minor_version)
-               rdev->sectors = (i_size_read(rdev->bdev->bd_inode) >> 9) -
-                       le64_to_cpu(sb->data_offset);
-       else
-               rdev->sectors = rdev->sb_start;
-       if (rdev->sectors < le64_to_cpu(sb->data_size))
+       if (minor_version) {
+               sectors = (i_size_read(rdev->bdev->bd_inode) >> 9);
+               sectors -= rdev->data_offset;
+       } else
+               sectors = rdev->sb_start;
+       if (sectors < le64_to_cpu(sb->data_size))
                return -EINVAL;
        rdev->sectors = le64_to_cpu(sb->data_size);
-       if (le64_to_cpu(sb->size) > rdev->sectors)
-               return -EINVAL;
        return ret;
 }
 
@@ -1743,7 +1766,6 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
        sb->feature_map = 0;
        sb->pad0 = 0;
        sb->recovery_offset = cpu_to_le64(0);
-       memset(sb->pad1, 0, sizeof(sb->pad1));
        memset(sb->pad3, 0, sizeof(sb->pad3));
 
        sb->utime = cpu_to_le64((__u64)mddev->utime);
@@ -1765,6 +1787,8 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
                sb->devflags |= WriteMostly1;
        else
                sb->devflags &= ~WriteMostly1;
+       sb->data_offset = cpu_to_le64(rdev->data_offset);
+       sb->data_size = cpu_to_le64(rdev->sectors);
 
        if (mddev->bitmap && mddev->bitmap_info.file == NULL) {
                sb->bitmap_offset = cpu_to_le32((__u32)mddev->bitmap_info.offset);
@@ -1793,6 +1817,12 @@ static void super_1_sync(struct mddev *mddev, struct md_rdev *rdev)
                    mddev->reshape_backwards)
                        sb->feature_map
                                |= cpu_to_le32(MD_FEATURE_RESHAPE_BACKWARDS);
+               if (rdev->new_data_offset != rdev->data_offset) {
+                       sb->feature_map
+                               |= cpu_to_le32(MD_FEATURE_NEW_OFFSET);
+                       sb->new_offset = cpu_to_le32((__u32)(rdev->new_data_offset
+                                                            - rdev->data_offset));
+               }
        }
 
        if (rdev->badblocks.count == 0)
@@ -1869,6 +1899,8 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
        sector_t max_sectors;
        if (num_sectors && num_sectors < rdev->mddev->dev_sectors)
                return 0; /* component must fit device */
+       if (rdev->data_offset != rdev->new_data_offset)
+               return 0; /* too confusing */
        if (rdev->sb_start < rdev->data_offset) {
                /* minor versions 1 and 2; superblock before data */
                max_sectors = i_size_read(rdev->bdev->bd_inode) >> 9;
@@ -1896,6 +1928,40 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
                       rdev->sb_page);
        md_super_wait(rdev->mddev);
        return num_sectors;
+
+}
+
+static int
+super_1_allow_new_offset(struct md_rdev *rdev,
+                        unsigned long long new_offset)
+{
+       /* All necessary checks on new >= old have been done */
+       struct bitmap *bitmap;
+       if (new_offset >= rdev->data_offset)
+               return 1;
+
+       /* with 1.0 metadata, there is no metadata to tread on
+        * so we can always move back */
+       if (rdev->mddev->minor_version == 0)
+               return 1;
+
+       /* otherwise we must be sure not to step on
+        * any metadata, so stay:
+        * 36K beyond start of superblock
+        * beyond end of badblocks
+        * beyond write-intent bitmap
+        */
+       if (rdev->sb_start + (32+4)*2 > new_offset)
+               return 0;
+       bitmap = rdev->mddev->bitmap;
+       if (bitmap && !rdev->mddev->bitmap_info.file &&
+           rdev->sb_start + rdev->mddev->bitmap_info.offset +
+           bitmap->file_pages * (PAGE_SIZE>>9) > new_offset)
+               return 0;
+       if (rdev->badblocks.sector + rdev->badblocks.size > new_offset)
+               return 0;
+
+       return 1;
 }
 
 static struct super_type super_types[] = {
@@ -1906,6 +1972,7 @@ static struct super_type super_types[] = {
                .validate_super     = super_90_validate,
                .sync_super         = super_90_sync,
                .rdev_size_change   = super_90_rdev_size_change,
+               .allow_new_offset   = super_90_allow_new_offset,
        },
        [1] = {
                .name   = "md-1",
@@ -1914,6 +1981,7 @@ static struct super_type super_types[] = {
                .validate_super     = super_1_validate,
                .sync_super         = super_1_sync,
                .rdev_size_change   = super_1_rdev_size_change,
+               .allow_new_offset   = super_1_allow_new_offset,
        },
 };
 
@@ -2821,9 +2889,8 @@ offset_show(struct md_rdev *rdev, char *page)
 static ssize_t
 offset_store(struct md_rdev *rdev, const char *buf, size_t len)
 {
-       char *e;
-       unsigned long long offset = simple_strtoull(buf, &e, 10);
-       if (e==buf || (*e && *e != '\n'))
+       unsigned long long offset;
+       if (strict_strtoull(buf, 10, &offset) < 0)
                return -EINVAL;
        if (rdev->mddev->pers && rdev->raid_disk >= 0)
                return -EBUSY;
@@ -2838,6 +2905,63 @@ offset_store(struct md_rdev *rdev, const char *buf, size_t len)
 static struct rdev_sysfs_entry rdev_offset =
 __ATTR(offset, S_IRUGO|S_IWUSR, offset_show, offset_store);
 
+static ssize_t new_offset_show(struct md_rdev *rdev, char *page)
+{
+       return sprintf(page, "%llu\n",
+                      (unsigned long long)rdev->new_data_offset);
+}
+
+static ssize_t new_offset_store(struct md_rdev *rdev,
+                               const char *buf, size_t len)
+{
+       unsigned long long new_offset;
+       struct mddev *mddev = rdev->mddev;
+
+       if (strict_strtoull(buf, 10, &new_offset) < 0)
+               return -EINVAL;
+
+       if (mddev->sync_thread)
+               return -EBUSY;
+       if (new_offset == rdev->data_offset)
+               /* reset is always permitted */
+               ;
+       else if (new_offset > rdev->data_offset) {
+               /* must not push array size beyond rdev_sectors */
+               if (new_offset - rdev->data_offset
+                   + mddev->dev_sectors > rdev->sectors)
+                               return -E2BIG;
+       }
+       /* Metadata worries about other space details. */
+
+       /* decreasing the offset is inconsistent with a backwards
+        * reshape.
+        */
+       if (new_offset < rdev->data_offset &&
+           mddev->reshape_backwards)
+               return -EINVAL;
+       /* Increasing offset is inconsistent with forwards
+        * reshape.  reshape_direction should be set to
+        * 'backwards' first.
+        */
+       if (new_offset > rdev->data_offset &&
+           !mddev->reshape_backwards)
+               return -EINVAL;
+
+       if (mddev->pers && mddev->persistent &&
+           !super_types[mddev->major_version]
+           .allow_new_offset(rdev, new_offset))
+               return -E2BIG;
+       rdev->new_data_offset = new_offset;
+       if (new_offset > rdev->data_offset)
+               mddev->reshape_backwards = 1;
+       else if (new_offset < rdev->data_offset)
+               mddev->reshape_backwards = 0;
+
+       return len;
+}
+static struct rdev_sysfs_entry rdev_new_offset =
+__ATTR(new_offset, S_IRUGO|S_IWUSR, new_offset_show, new_offset_store);
+
 static ssize_t
 rdev_size_show(struct md_rdev *rdev, char *page)
 {
@@ -2882,6 +3006,8 @@ rdev_size_store(struct md_rdev *rdev, const char *buf, size_t len)
 
        if (strict_blocks_to_sectors(buf, &sectors) < 0)
                return -EINVAL;
+       if (rdev->data_offset != rdev->new_data_offset)
+               return -EINVAL; /* too confusing */
        if (my_mddev->pers && rdev->raid_disk >= 0) {
                if (my_mddev->persistent) {
                        sectors = super_types[my_mddev->major_version].
@@ -3018,6 +3144,7 @@ static struct attribute *rdev_default_attrs[] = {
        &rdev_errors.attr,
        &rdev_slot.attr,
        &rdev_offset.attr,
+       &rdev_new_offset.attr,
        &rdev_size.attr,
        &rdev_recovery_start.attr,
        &rdev_bad_blocks.attr,
@@ -3092,6 +3219,7 @@ int md_rdev_init(struct md_rdev *rdev)
        rdev->raid_disk = -1;
        rdev->flags = 0;
        rdev->data_offset = 0;
+       rdev->new_data_offset = 0;
        rdev->sb_events = 0;
        rdev->last_read_error.tv_sec  = 0;
        rdev->last_read_error.tv_nsec = 0;
@@ -3596,7 +3724,17 @@ raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
        if (mddev->pers)
                rv = update_raid_disks(mddev, n);
        else if (mddev->reshape_position != MaxSector) {
+               struct md_rdev *rdev;
                int olddisks = mddev->raid_disks - mddev->delta_disks;
+
+               rdev_for_each(rdev, mddev) {
+                       if (olddisks < n &&
+                           rdev->data_offset < rdev->new_data_offset)
+                               return -EINVAL;
+                       if (olddisks > n &&
+                           rdev->data_offset > rdev->new_data_offset)
+                               return -EINVAL;
+               }
                mddev->delta_disks = n - olddisks;
                mddev->raid_disks = n;
                mddev->reshape_backwards = (mddev->delta_disks < 0);
@@ -4443,6 +4581,7 @@ reshape_position_show(struct mddev *mddev, char *page)
 static ssize_t
 reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
 {
+       struct md_rdev *rdev;
        char *e;
        unsigned long long new = simple_strtoull(buf, &e, 10);
        if (mddev->pers)
@@ -4455,6 +4594,8 @@ reshape_position_store(struct mddev *mddev, const char *buf, size_t len)
        mddev->new_level = mddev->level;
        mddev->new_layout = mddev->layout;
        mddev->new_chunk_sectors = mddev->chunk_sectors;
+       rdev_for_each(rdev, mddev)
+               rdev->new_data_offset = rdev->data_offset;
        return len;
 }
 
@@ -5999,6 +6140,7 @@ static int update_size(struct mddev *mddev, sector_t num_sectors)
 static int update_raid_disks(struct mddev *mddev, int raid_disks)
 {
        int rv;
+       struct md_rdev *rdev;
        /* change the number of raid disks */
        if (mddev->pers->check_reshape == NULL)
                return -EINVAL;
@@ -6007,6 +6149,16 @@ static int update_raid_disks(struct mddev *mddev, int raid_disks)
                return -EINVAL;
        if (mddev->sync_thread || mddev->reshape_position != MaxSector)
                return -EBUSY;
+
+       rdev_for_each(rdev, mddev) {
+               if (mddev->raid_disks < raid_disks &&
+                   rdev->data_offset < rdev->new_data_offset)
+                       return -EINVAL;
+               if (mddev->raid_disks > raid_disks &&
+                   rdev->data_offset > rdev->new_data_offset)
+                       return -EINVAL;
+       }
+
        mddev->delta_disks = raid_disks - mddev->raid_disks;
        if (mddev->delta_disks < 0)
                mddev->reshape_backwards = 1;
@@ -7707,6 +7859,20 @@ void md_wait_for_blocked_rdev(struct md_rdev *rdev, struct mddev *mddev)
 }
 EXPORT_SYMBOL(md_wait_for_blocked_rdev);
 
+void md_finish_reshape(struct mddev *mddev)
+{
+       /* called be personality module when reshape completes. */
+       struct md_rdev *rdev;
+
+       rdev_for_each(rdev, mddev) {
+               if (rdev->data_offset > rdev->new_data_offset)
+                       rdev->sectors += rdev->data_offset - rdev->new_data_offset;
+               else
+                       rdev->sectors -= rdev->new_data_offset - rdev->data_offset;
+               rdev->data_offset = rdev->new_data_offset;
+       }
+}
+EXPORT_SYMBOL(md_finish_reshape);
 
 /* Bad block management.
  * We can record which blocks on each device are 'bad' and so just
@@ -7955,10 +8121,15 @@ static int md_set_badblocks(struct badblocks *bb, sector_t s, int sectors,
 }
 
 int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
-                      int acknowledged)
+                      int is_new)
 {
-       int rv = md_set_badblocks(&rdev->badblocks,
-                                 s + rdev->data_offset, sectors, acknowledged);
+       int rv;
+       if (is_new)
+               s += rdev->new_data_offset;
+       else
+               s += rdev->data_offset;
+       rv = md_set_badblocks(&rdev->badblocks,
+                             s, sectors, 0);
        if (rv) {
                /* Make sure they get written out promptly */
                sysfs_notify_dirent_safe(rdev->sysfs_state);
@@ -8064,11 +8235,15 @@ out:
        return rv;
 }
 
-int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors)
+int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
+                        int is_new)
 {
+       if (is_new)
+               s += rdev->new_data_offset;
+       else
+               s += rdev->data_offset;
        return md_clear_badblocks(&rdev->badblocks,
-                                 s + rdev->data_offset,
-                                 sectors);
+                                 s, sectors);
 }
 EXPORT_SYMBOL_GPL(rdev_clear_badblocks);
 

diff --git a/drivers/md/md.h b/drivers/md/md.h
index d51c0ca37777e536b3a63adf68616c7d78d76161..98913e8dac1a36e8cf40902235b12201eb09d15e 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -55,6 +55,7 @@ struct md_rdev {
        int             sb_loaded;
        __u64           sb_events;
        sector_t        data_offset;    /* start of data in array */
+       sector_t        new_data_offset;/* only relevant while reshaping */
        sector_t        sb_start;       /* offset of the super block (in 512byte sectors) */
        int             sb_size;        /* bytes in the superblock */
        int             preferred_minor;        /* autorun support */
@@ -193,8 +194,9 @@ static inline int is_badblock(struct md_rdev *rdev, sector_t s, int sectors,
        return 0;
 }
 extern int rdev_set_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
-                             int acknowledged);
-extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors);
+                             int is_new);
+extern int rdev_clear_badblocks(struct md_rdev *rdev, sector_t s, int sectors,
+                               int is_new);
 extern void md_ack_all_badblocks(struct badblocks *bb);
 
 struct mddev {
@@ -592,6 +594,7 @@ extern void md_write_start(struct mddev *mddev, struct bio *bi);
 extern void md_write_end(struct mddev *mddev);
 extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
 extern void md_error(struct mddev *mddev, struct md_rdev *rdev);
+extern void md_finish_reshape(struct mddev *mddev);
 
 extern int mddev_congested(struct mddev *mddev, int bits);
 extern void md_flush_request(struct mddev *mddev, struct bio *bio);

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 15dd59b84e94442c50ae164cb2ec1c130a74bc52..71a7dc038a82316525609fa285e5416f324d43b5 100644 (file)
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2024,7 +2024,7 @@ static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio
                        continue;
                if (test_bit(BIO_UPTODATE, &bio->bi_flags) &&
                    test_bit(R1BIO_MadeGood, &r1_bio->state)) {
-                       rdev_clear_badblocks(rdev, r1_bio->sector, s);
+                       rdev_clear_badblocks(rdev, r1_bio->sector, s, 0);
                }
                if (!test_bit(BIO_UPTODATE, &bio->bi_flags) &&
                    test_bit(R1BIO_WriteError, &r1_bio->state)) {
@@ -2044,7 +2044,7 @@ static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio)
                        struct md_rdev *rdev = conf->mirrors[m].rdev;
                        rdev_clear_badblocks(rdev,
                                             r1_bio->sector,
-                                            r1_bio->sectors);
+                                            r1_bio->sectors, 0);
                        rdev_dec_pending(rdev, conf->mddev);
                } else if (r1_bio->bios[m] != NULL) {
                        /* This drive got a write error.  We need to

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index c8dbb84d53579ab3e5c9ebc012a06cdb5205058f..6419125c2fbff30df7b6f1ccde9981324f4cd457 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2480,7 +2480,7 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
                                rdev_clear_badblocks(
                                        rdev,
                                        r10_bio->devs[m].addr,
-                                       r10_bio->sectors);
+                                       r10_bio->sectors, 0);
                        } else {
                                if (!rdev_set_badblocks(
                                            rdev,
@@ -2496,7 +2496,7 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
                                rdev_clear_badblocks(
                                        rdev,
                                        r10_bio->devs[m].addr,
-                                       r10_bio->sectors);
+                                       r10_bio->sectors, 0);
                        } else {
                                if (!rdev_set_badblocks(
                                            rdev,
@@ -2515,7 +2515,7 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
                                rdev_clear_badblocks(
                                        rdev,
                                        r10_bio->devs[m].addr,
-                                       r10_bio->sectors);
+                                       r10_bio->sectors, 0);
                                rdev_dec_pending(rdev, conf->mddev);
                        } else if (bio != NULL &&
                                   !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
@@ -2532,7 +2532,7 @@ static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
                                rdev_clear_badblocks(
                                        rdev,
                                        r10_bio->devs[m].addr,
-                                       r10_bio->sectors);
+                                       r10_bio->sectors, 0);
                                rdev_dec_pending(rdev, conf->mddev);
                        }
                }

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 0abbd3447cfb9e9c466dcb627af1d6e8285bbdd9..3705585d756700739866350cdf498138b3902f33 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -3561,7 +3561,7 @@ finish:
                        if (test_and_clear_bit(R5_MadeGood, &dev->flags)) {
                                rdev = conf->disks[i].rdev;
                                rdev_clear_badblocks(rdev, sh->sector,
-                                                    STRIPE_SECTORS);
+                                                    STRIPE_SECTORS, 0);
                                rdev_dec_pending(rdev, conf->mddev);
                        }
                        if (test_and_clear_bit(R5_MadeGoodRepl, &dev->flags)) {
@@ -3570,7 +3570,7 @@ finish:
                                        /* rdev have been moved down */
                                        rdev = conf->disks[i].rdev;
                                rdev_clear_badblocks(rdev, sh->sector,
-                                                    STRIPE_SECTORS);
+                                                    STRIPE_SECTORS, 0);
                                rdev_dec_pending(rdev, conf->mddev);
                        }
                }
@@ -5505,10 +5505,14 @@ static int raid5_start_reshape(struct mddev *mddev)
        if (!check_stripe_cache(mddev))
                return -ENOSPC;
 
-       rdev_for_each(rdev, mddev)
+       rdev_for_each(rdev, mddev) {
+               /* Don't support changing data_offset yet */
+               if (rdev->new_data_offset != rdev->data_offset)
+                       return -EINVAL;
                if (!test_bit(In_sync, &rdev->flags)
                    && !test_bit(Faulty, &rdev->flags))
                        spares++;
+       }
 
        if (spares - mddev->degraded < mddev->delta_disks - conf->max_degraded)
                /* Not enough devices even to make a degraded array

diff --git a/include/linux/raid/md_p.h b/include/linux/raid/md_p.h
index 07e05f92d050759e2262f2ca15cecf9d7d693d38..ee753536ab7088350a147e1743805985a6b01ac0 100644 (file)
--- a/include/linux/raid/md_p.h
+++ b/include/linux/raid/md_p.h
@@ -233,7 +233,10 @@ struct mdp_superblock_1 {
        __le32  delta_disks;    /* change in number of raid_disks               */
        __le32  new_layout;     /* new layout                                   */
        __le32  new_chunk;      /* new chunk size (512byte sectors)             */
-       __u8    pad1[128-124];  /* set to 0 when written */
+       __le32  new_offset;     /* signed number to add to data_offset in new
+                                * layout.  0 == no-change.  This can be
+                                * different on each device in the array.
+                                */
 
        /* constant this-device information - 64 bytes */
        __le64  data_offset;    /* sector start of data, often 0 */
@@ -285,11 +288,14 @@ struct mdp_superblock_1 {
                                            * of devices, but is going
                                            * backwards anyway.
                                            */
+#define        MD_FEATURE_NEW_OFFSET           64 /* new_offset must be honoured */
 #define        MD_FEATURE_ALL                  (MD_FEATURE_BITMAP_OFFSET       \
                                        |MD_FEATURE_RECOVERY_OFFSET     \
                                        |MD_FEATURE_RESHAPE_ACTIVE      \
                                        |MD_FEATURE_BAD_BLOCKS          \
                                        |MD_FEATURE_REPLACEMENT         \
-                                       |MD_FEATURE_RESHAPE_BACKWARDS)
+                                       |MD_FEATURE_RESHAPE_BACKWARDS   \
+                                       |MD_FEATURE_NEW_OFFSET          \
+                                       )
 
 #endif