]> git.proxmox.com Git - mirror_ubuntu-zesty-kernel.git/blobdiff - drivers/md/raid10.c
md/raid10: handle further errors during fix_read_error better.
[mirror_ubuntu-zesty-kernel.git] / drivers / md / raid10.c
index a5ecea2672b57dff49ed1b7aa0d616821a38f273..8b29cd4f01c89f8213d7dcc43cd1aaf6dd5799c7 100644 (file)
@@ -181,7 +181,7 @@ static void put_all_bios(conf_t *conf, r10bio_t *r10_bio)
 
        for (i = 0; i < conf->copies; i++) {
                struct bio **bio = & r10_bio->devs[i].bio;
-               if (*bio && *bio != IO_BLOCKED)
+               if (!BIO_SPECIAL(*bio))
                        bio_put(*bio);
                *bio = NULL;
        }
@@ -267,7 +267,8 @@ static inline void update_head_pos(int slot, r10bio_t *r10_bio)
 /*
  * Find the disk number which triggered given bio
  */
-static int find_bio_disk(conf_t *conf, r10bio_t *r10_bio, struct bio *bio)
+static int find_bio_disk(conf_t *conf, r10bio_t *r10_bio,
+                        struct bio *bio, int *slotp)
 {
        int slot;
 
@@ -278,6 +279,8 @@ static int find_bio_disk(conf_t *conf, r10bio_t *r10_bio, struct bio *bio)
        BUG_ON(slot == conf->copies);
        update_head_pos(slot, r10_bio);
 
+       if (slotp)
+               *slotp = slot;
        return r10_bio->devs[slot].devnum;
 }
 
@@ -324,23 +327,35 @@ static void raid10_end_read_request(struct bio *bio, int error)
        }
 }
 
+static void close_write(r10bio_t *r10_bio)
+{
+       /* clear the bitmap if all writes complete successfully */
+       bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
+                       r10_bio->sectors,
+                       !test_bit(R10BIO_Degraded, &r10_bio->state),
+                       0);
+       md_write_end(r10_bio->mddev);
+}
+
 static void raid10_end_write_request(struct bio *bio, int error)
 {
        int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
        r10bio_t *r10_bio = bio->bi_private;
        int dev;
+       int dec_rdev = 1;
        conf_t *conf = r10_bio->mddev->private;
+       int slot;
 
-       dev = find_bio_disk(conf, r10_bio, bio);
+       dev = find_bio_disk(conf, r10_bio, bio, &slot);
 
        /*
         * this branch is our 'one mirror IO has finished' event handler:
         */
        if (!uptodate) {
-               md_error(r10_bio->mddev, conf->mirrors[dev].rdev);
-               /* an I/O failed, we can't clear the bitmap */
-               set_bit(R10BIO_Degraded, &r10_bio->state);
-       } else
+               set_bit(WriteErrorSeen, &conf->mirrors[dev].rdev->flags);
+               set_bit(R10BIO_WriteError, &r10_bio->state);
+               dec_rdev = 0;
+       } else {
                /*
                 * Set R10BIO_Uptodate in our master bio, so that
                 * we will return a good error code for to the higher
@@ -350,24 +365,41 @@ static void raid10_end_write_request(struct bio *bio, int error)
                 * user-side. So if something waits for IO, then it will
                 * wait for the 'master' bio.
                 */
+               sector_t first_bad;
+               int bad_sectors;
+
                set_bit(R10BIO_Uptodate, &r10_bio->state);
 
+               /* Maybe we can clear some bad blocks. */
+               if (is_badblock(conf->mirrors[dev].rdev,
+                               r10_bio->devs[slot].addr,
+                               r10_bio->sectors,
+                               &first_bad, &bad_sectors)) {
+                       bio_put(bio);
+                       r10_bio->devs[slot].bio = IO_MADE_GOOD;
+                       dec_rdev = 0;
+                       set_bit(R10BIO_MadeGood, &r10_bio->state);
+               }
+       }
+
        /*
         *
         * Let's see if all mirrored write operations have finished
         * already.
         */
        if (atomic_dec_and_test(&r10_bio->remaining)) {
-               /* clear the bitmap if all writes complete successfully */
-               bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector,
-                               r10_bio->sectors,
-                               !test_bit(R10BIO_Degraded, &r10_bio->state),
-                               0);
-               md_write_end(r10_bio->mddev);
-               raid_end_bio_io(r10_bio);
+               if (test_bit(R10BIO_WriteError, &r10_bio->state))
+                       reschedule_retry(r10_bio);
+               else {
+                       close_write(r10_bio);
+                       if (test_bit(R10BIO_MadeGood, &r10_bio->state))
+                               reschedule_retry(r10_bio);
+                       else
+                               raid_end_bio_io(r10_bio);
+               }
        }
-
-       rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
+       if (dec_rdev)
+               rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev);
 }
 
 
@@ -807,6 +839,8 @@ static int make_request(mddev_t *mddev, struct bio * bio)
        unsigned long flags;
        mdk_rdev_t *blocked_rdev;
        int plugged;
+       int sectors_handled;
+       int max_sectors;
 
        if (unlikely(bio->bi_rw & REQ_FLUSH)) {
                md_flush_request(mddev, bio);
@@ -895,7 +929,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
                /*
                 * read balancing logic:
                 */
-               int max_sectors;
                int disk;
                int slot;
 
@@ -925,8 +958,6 @@ read_again:
                        /* Could not read all from this device, so we will
                         * need another r10_bio.
                         */
-                       int sectors_handled;
-
                        sectors_handled = (r10_bio->sectors + max_sectors
                                           - bio->bi_sector);
                        r10_bio->sectors = max_sectors;
@@ -963,13 +994,22 @@ read_again:
        /* first select target devices under rcu_lock and
         * inc refcount on their rdev.  Record them by setting
         * bios[x] to bio
+        * If there are known/acknowledged bad blocks on any device
+        * on which we have seen a write error, we want to avoid
+        * writing to those blocks.  This potentially requires several
+        * writes to write around the bad blocks.  Each set of writes
+        * gets its own r10_bio with a set of bios attached.  The number
+        * of r10_bios is recored in bio->bi_phys_segments just as with
+        * the read case.
         */
        plugged = mddev_check_plugged(mddev);
 
        raid10_find_phys(conf, r10_bio);
- retry_write:
+retry_write:
        blocked_rdev = NULL;
        rcu_read_lock();
+       max_sectors = r10_bio->sectors;
+
        for (i = 0;  i < conf->copies; i++) {
                int d = r10_bio->devs[i].devnum;
                mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev);
@@ -978,13 +1018,55 @@ read_again:
                        blocked_rdev = rdev;
                        break;
                }
-               if (rdev && !test_bit(Faulty, &rdev->flags)) {
-                       atomic_inc(&rdev->nr_pending);
-                       r10_bio->devs[i].bio = bio;
-               } else {
-                       r10_bio->devs[i].bio = NULL;
+               r10_bio->devs[i].bio = NULL;
+               if (!rdev || test_bit(Faulty, &rdev->flags)) {
                        set_bit(R10BIO_Degraded, &r10_bio->state);
+                       continue;
+               }
+               if (test_bit(WriteErrorSeen, &rdev->flags)) {
+                       sector_t first_bad;
+                       sector_t dev_sector = r10_bio->devs[i].addr;
+                       int bad_sectors;
+                       int is_bad;
+
+                       is_bad = is_badblock(rdev, dev_sector,
+                                            max_sectors,
+                                            &first_bad, &bad_sectors);
+                       if (is_bad < 0) {
+                               /* Mustn't write here until the bad block
+                                * is acknowledged
+                                */
+                               atomic_inc(&rdev->nr_pending);
+                               set_bit(BlockedBadBlocks, &rdev->flags);
+                               blocked_rdev = rdev;
+                               break;
+                       }
+                       if (is_bad && first_bad <= dev_sector) {
+                               /* Cannot write here at all */
+                               bad_sectors -= (dev_sector - first_bad);
+                               if (bad_sectors < max_sectors)
+                                       /* Mustn't write more than bad_sectors
+                                        * to other devices yet
+                                        */
+                                       max_sectors = bad_sectors;
+                               /* We don't set R10BIO_Degraded as that
+                                * only applies if the disk is missing,
+                                * so it might be re-added, and we want to
+                                * know to recover this chunk.
+                                * In this case the device is here, and the
+                                * fact that this chunk is not in-sync is
+                                * recorded in the bad block log.
+                                */
+                               continue;
+                       }
+                       if (is_bad) {
+                               int good_sectors = first_bad - dev_sector;
+                               if (good_sectors < max_sectors)
+                                       max_sectors = good_sectors;
+                       }
                }
+               r10_bio->devs[i].bio = bio;
+               atomic_inc(&rdev->nr_pending);
        }
        rcu_read_unlock();
 
@@ -1004,8 +1086,22 @@ read_again:
                goto retry_write;
        }
 
+       if (max_sectors < r10_bio->sectors) {
+               /* We are splitting this into multiple parts, so
+                * we need to prepare for allocating another r10_bio.
+                */
+               r10_bio->sectors = max_sectors;
+               spin_lock_irq(&conf->device_lock);
+               if (bio->bi_phys_segments == 0)
+                       bio->bi_phys_segments = 2;
+               else
+                       bio->bi_phys_segments++;
+               spin_unlock_irq(&conf->device_lock);
+       }
+       sectors_handled = r10_bio->sector + max_sectors - bio->bi_sector;
+
        atomic_set(&r10_bio->remaining, 1);
-       bitmap_startwrite(mddev->bitmap, bio->bi_sector, r10_bio->sectors, 0);
+       bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0);
 
        for (i = 0; i < conf->copies; i++) {
                struct bio *mbio;
@@ -1014,10 +1110,12 @@ read_again:
                        continue;
 
                mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+               md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
+                           max_sectors);
                r10_bio->devs[i].bio = mbio;
 
-               mbio->bi_sector = r10_bio->devs[i].addr+
-                       conf->mirrors[d].rdev->data_offset;
+               mbio->bi_sector = (r10_bio->devs[i].addr+
+                                  conf->mirrors[d].rdev->data_offset);
                mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
                mbio->bi_end_io = raid10_end_write_request;
                mbio->bi_rw = WRITE | do_sync | do_fua;
@@ -1042,6 +1140,21 @@ read_again:
        /* In case raid10d snuck in to freeze_array */
        wake_up(&conf->wait_barrier);
 
+       if (sectors_handled < (bio->bi_size >> 9)) {
+               /* We need another r10_bio.  It has already been counted
+                * in bio->bi_phys_segments.
+                */
+               r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
+
+               r10_bio->master_bio = bio;
+               r10_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
+
+               r10_bio->mddev = mddev;
+               r10_bio->sector = bio->bi_sector + sectors_handled;
+               r10_bio->state = 0;
+               goto retry_write;
+       }
+
        if (do_sync || !mddev->bitmap || !plugged)
                md_wakeup_thread(mddev->thread);
        return 0;
@@ -1203,9 +1316,6 @@ static int raid10_add_disk(mddev_t *mddev, mdk_rdev_t *rdev)
        int first = 0;
        int last = conf->raid_disks - 1;
 
-       if (rdev->badblocks.count)
-               return -EINVAL;
-
        if (mddev->recovery_cp < MaxSector)
                /* only hot-add to in-sync arrays, as recovery is
                 * very different from resync
@@ -1304,17 +1414,16 @@ static void end_sync_read(struct bio *bio, int error)
        conf_t *conf = r10_bio->mddev->private;
        int d;
 
-       d = find_bio_disk(conf, r10_bio, bio);
+       d = find_bio_disk(conf, r10_bio, bio, NULL);
 
        if (test_bit(BIO_UPTODATE, &bio->bi_flags))
                set_bit(R10BIO_Uptodate, &r10_bio->state);
-       else {
+       else
+               /* The write handler will notice the lack of
+                * R10BIO_Uptodate and record any errors etc
+                */
                atomic_add(r10_bio->sectors,
                           &conf->mirrors[d].rdev->corrected_errors);
-               if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
-                       md_error(r10_bio->mddev,
-                                conf->mirrors[d].rdev);
-       }
 
        /* for reconstruct, we always reschedule after a read.
         * for resync, only after all reads
@@ -1329,35 +1438,60 @@ static void end_sync_read(struct bio *bio, int error)
        }
 }
 
-static void end_sync_write(struct bio *bio, int error)
+static void end_sync_request(r10bio_t *r10_bio)
 {
-       int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
-       r10bio_t *r10_bio = bio->bi_private;
        mddev_t *mddev = r10_bio->mddev;
-       conf_t *conf = mddev->private;
-       int d;
-
-       d = find_bio_disk(conf, r10_bio, bio);
 
-       if (!uptodate)
-               md_error(mddev, conf->mirrors[d].rdev);
-
-       rdev_dec_pending(conf->mirrors[d].rdev, mddev);
        while (atomic_dec_and_test(&r10_bio->remaining)) {
                if (r10_bio->master_bio == NULL) {
                        /* the primary of several recovery bios */
                        sector_t s = r10_bio->sectors;
-                       put_buf(r10_bio);
+                       if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
+                           test_bit(R10BIO_WriteError, &r10_bio->state))
+                               reschedule_retry(r10_bio);
+                       else
+                               put_buf(r10_bio);
                        md_done_sync(mddev, s, 1);
                        break;
                } else {
                        r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio;
-                       put_buf(r10_bio);
+                       if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
+                           test_bit(R10BIO_WriteError, &r10_bio->state))
+                               reschedule_retry(r10_bio);
+                       else
+                               put_buf(r10_bio);
                        r10_bio = r10_bio2;
                }
        }
 }
 
+static void end_sync_write(struct bio *bio, int error)
+{
+       int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
+       r10bio_t *r10_bio = bio->bi_private;
+       mddev_t *mddev = r10_bio->mddev;
+       conf_t *conf = mddev->private;
+       int d;
+       sector_t first_bad;
+       int bad_sectors;
+       int slot;
+
+       d = find_bio_disk(conf, r10_bio, bio, &slot);
+
+       if (!uptodate) {
+               set_bit(WriteErrorSeen, &conf->mirrors[d].rdev->flags);
+               set_bit(R10BIO_WriteError, &r10_bio->state);
+       } else if (is_badblock(conf->mirrors[d].rdev,
+                            r10_bio->devs[slot].addr,
+                            r10_bio->sectors,
+                            &first_bad, &bad_sectors))
+               set_bit(R10BIO_MadeGood, &r10_bio->state);
+
+       rdev_dec_pending(conf->mirrors[d].rdev, mddev);
+
+       end_sync_request(r10_bio);
+}
+
 /*
  * Note: sync and recover and handled very differently for raid10
  * This code is for resync.
@@ -1417,11 +1551,12 @@ static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio)
                        if (j == vcnt)
                                continue;
                        mddev->resync_mismatches += r10_bio->sectors;
+                       if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
+                               /* Don't fix anything. */
+                               continue;
                }
-               if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
-                       /* Don't fix anything. */
-                       continue;
-               /* Ok, we need to write this bio
+               /* Ok, we need to write this bio, either to correct an
+                * inconsistency or to correct an unreadable block.
                 * First we need to fixup bv_offset, bv_len and
                 * bi_vecs, as the read request might have corrupted these
                 */
@@ -1473,6 +1608,84 @@ done:
  * The second for writing.
  *
  */
+static void fix_recovery_read_error(r10bio_t *r10_bio)
+{
+       /* We got a read error during recovery.
+        * We repeat the read in smaller page-sized sections.
+        * If a read succeeds, write it to the new device or record
+        * a bad block if we cannot.
+        * If a read fails, record a bad block on both old and
+        * new devices.
+        */
+       mddev_t *mddev = r10_bio->mddev;
+       conf_t *conf = mddev->private;
+       struct bio *bio = r10_bio->devs[0].bio;
+       sector_t sect = 0;
+       int sectors = r10_bio->sectors;
+       int idx = 0;
+       int dr = r10_bio->devs[0].devnum;
+       int dw = r10_bio->devs[1].devnum;
+
+       while (sectors) {
+               int s = sectors;
+               mdk_rdev_t *rdev;
+               sector_t addr;
+               int ok;
+
+               if (s > (PAGE_SIZE>>9))
+                       s = PAGE_SIZE >> 9;
+
+               rdev = conf->mirrors[dr].rdev;
+               addr = r10_bio->devs[0].addr + sect,
+               ok = sync_page_io(rdev,
+                                 addr,
+                                 s << 9,
+                                 bio->bi_io_vec[idx].bv_page,
+                                 READ, false);
+               if (ok) {
+                       rdev = conf->mirrors[dw].rdev;
+                       addr = r10_bio->devs[1].addr + sect;
+                       ok = sync_page_io(rdev,
+                                         addr,
+                                         s << 9,
+                                         bio->bi_io_vec[idx].bv_page,
+                                         WRITE, false);
+                       if (!ok)
+                               set_bit(WriteErrorSeen, &rdev->flags);
+               }
+               if (!ok) {
+                       /* We don't worry if we cannot set a bad block -
+                        * it really is bad so there is no loss in not
+                        * recording it yet
+                        */
+                       rdev_set_badblocks(rdev, addr, s, 0);
+
+                       if (rdev != conf->mirrors[dw].rdev) {
+                               /* need bad block on destination too */
+                               mdk_rdev_t *rdev2 = conf->mirrors[dw].rdev;
+                               addr = r10_bio->devs[1].addr + sect;
+                               ok = rdev_set_badblocks(rdev2, addr, s, 0);
+                               if (!ok) {
+                                       /* just abort the recovery */
+                                       printk(KERN_NOTICE
+                                              "md/raid10:%s: recovery aborted"
+                                              " due to read error\n",
+                                              mdname(mddev));
+
+                                       conf->mirrors[dw].recovery_disabled
+                                               = mddev->recovery_disabled;
+                                       set_bit(MD_RECOVERY_INTR,
+                                               &mddev->recovery);
+                                       break;
+                               }
+                       }
+               }
+
+               sectors -= s;
+               sect += s;
+               idx++;
+       }
+}
 
 static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
 {
@@ -1480,6 +1693,12 @@ static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
        int d;
        struct bio *wbio;
 
+       if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
+               fix_recovery_read_error(r10_bio);
+               end_sync_request(r10_bio);
+               return;
+       }
+
        /*
         * share the pages with the first bio
         * and submit the write request
@@ -1489,16 +1708,7 @@ static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio)
 
        atomic_inc(&conf->mirrors[d].rdev->nr_pending);
        md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
-       if (test_bit(R10BIO_Uptodate, &r10_bio->state))
-               generic_make_request(wbio);
-       else {
-               printk(KERN_NOTICE
-                      "md/raid10:%s: recovery aborted due to read error\n",
-                      mdname(mddev));
-               conf->mirrors[d].recovery_disabled = mddev->recovery_disabled;
-               set_bit(MD_RECOVERY_INTR, &mddev->recovery);
-               bio_endio(wbio, 0);
-       }
+       generic_make_request(wbio);
 }
 
 
@@ -1539,6 +1749,26 @@ static void check_decay_read_errors(mddev_t *mddev, mdk_rdev_t *rdev)
                atomic_set(&rdev->read_errors, read_errors >> hours_since_last);
 }
 
+static int r10_sync_page_io(mdk_rdev_t *rdev, sector_t sector,
+                           int sectors, struct page *page, int rw)
+{
+       sector_t first_bad;
+       int bad_sectors;
+
+       if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors)
+           && (rw == READ || test_bit(WriteErrorSeen, &rdev->flags)))
+               return -1;
+       if (sync_page_io(rdev, sector, sectors << 9, page, rw, false))
+               /* success */
+               return 1;
+       if (rw == WRITE)
+               set_bit(WriteErrorSeen, &rdev->flags);
+       /* need to record an error - either for the block or the device */
+       if (!rdev_set_badblocks(rdev, sector, sectors, 0))
+               md_error(rdev->mddev, rdev);
+       return 0;
+}
+
 /*
  * This is a kernel thread which:
  *
@@ -1622,9 +1852,19 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                rcu_read_unlock();
 
                if (!success) {
-                       /* Cannot read from anywhere -- bye bye array */
+                       /* Cannot read from anywhere, just mark the block
+                        * as bad on the first device to discourage future
+                        * reads.
+                        */
                        int dn = r10_bio->devs[r10_bio->read_slot].devnum;
-                       md_error(mddev, conf->mirrors[dn].rdev);
+                       rdev = conf->mirrors[dn].rdev;
+
+                       if (!rdev_set_badblocks(
+                                   rdev,
+                                   r10_bio->devs[r10_bio->read_slot].addr
+                                   + sect,
+                                   s, 0))
+                               md_error(mddev, rdev);
                        break;
                }
 
@@ -1645,10 +1885,10 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
 
                        atomic_inc(&rdev->nr_pending);
                        rcu_read_unlock();
-                       if (sync_page_io(rdev,
-                                        r10_bio->devs[sl].addr +
-                                        sect,
-                                        s<<9, conf->tmppage, WRITE, false)
+                       if (r10_sync_page_io(rdev,
+                                            r10_bio->devs[sl].addr +
+                                            sect,
+                                            s<<9, conf->tmppage, WRITE)
                            == 0) {
                                /* Well, this device is dead */
                                printk(KERN_NOTICE
@@ -1663,7 +1903,6 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                                       "drive\n",
                                       mdname(mddev),
                                       bdevname(rdev->bdev, b));
-                               md_error(mddev, rdev);
                        }
                        rdev_dec_pending(rdev, mddev);
                        rcu_read_lock();
@@ -1683,11 +1922,12 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
 
                        atomic_inc(&rdev->nr_pending);
                        rcu_read_unlock();
-                       if (sync_page_io(rdev,
-                                        r10_bio->devs[sl].addr +
-                                        sect,
-                                        s<<9, conf->tmppage,
-                                        READ, false) == 0) {
+                       switch (r10_sync_page_io(rdev,
+                                            r10_bio->devs[sl].addr +
+                                            sect,
+                                            s<<9, conf->tmppage,
+                                                READ)) {
+                       case 0:
                                /* Well, this device is dead */
                                printk(KERN_NOTICE
                                       "md/raid10:%s: unable to read back "
@@ -1701,9 +1941,8 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
                                       "drive\n",
                                       mdname(mddev),
                                       bdevname(rdev->bdev, b));
-
-                               md_error(mddev, rdev);
-                       } else {
+                               break;
+                       case 1:
                                printk(KERN_INFO
                                       "md/raid10:%s: read error corrected"
                                       " (%d sectors at %llu on %s)\n",
@@ -1724,6 +1963,82 @@ static void fix_read_error(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio)
        }
 }
 
+static void bi_complete(struct bio *bio, int error)
+{
+       complete((struct completion *)bio->bi_private);
+}
+
+static int submit_bio_wait(int rw, struct bio *bio)
+{
+       struct completion event;
+       rw |= REQ_SYNC;
+
+       init_completion(&event);
+       bio->bi_private = &event;
+       bio->bi_end_io = bi_complete;
+       submit_bio(rw, bio);
+       wait_for_completion(&event);
+
+       return test_bit(BIO_UPTODATE, &bio->bi_flags);
+}
+
+static int narrow_write_error(r10bio_t *r10_bio, int i)
+{
+       struct bio *bio = r10_bio->master_bio;
+       mddev_t *mddev = r10_bio->mddev;
+       conf_t *conf = mddev->private;
+       mdk_rdev_t *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev;
+       /* bio has the data to be written to slot 'i' where
+        * we just recently had a write error.
+        * We repeatedly clone the bio and trim down to one block,
+        * then try the write.  Where the write fails we record
+        * a bad block.
+        * It is conceivable that the bio doesn't exactly align with
+        * blocks.  We must handle this.
+        *
+        * We currently own a reference to the rdev.
+        */
+
+       int block_sectors;
+       sector_t sector;
+       int sectors;
+       int sect_to_write = r10_bio->sectors;
+       int ok = 1;
+
+       if (rdev->badblocks.shift < 0)
+               return 0;
+
+       block_sectors = 1 << rdev->badblocks.shift;
+       sector = r10_bio->sector;
+       sectors = ((r10_bio->sector + block_sectors)
+                  & ~(sector_t)(block_sectors - 1))
+               - sector;
+
+       while (sect_to_write) {
+               struct bio *wbio;
+               if (sectors > sect_to_write)
+                       sectors = sect_to_write;
+               /* Write at 'sector' for 'sectors' */
+               wbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+               md_trim_bio(wbio, sector - bio->bi_sector, sectors);
+               wbio->bi_sector = (r10_bio->devs[i].addr+
+                                  rdev->data_offset+
+                                  (sector - r10_bio->sector));
+               wbio->bi_bdev = rdev->bdev;
+               if (submit_bio_wait(WRITE, wbio) == 0)
+                       /* Failure! */
+                       ok = rdev_set_badblocks(rdev, sector,
+                                               sectors, 0)
+                               && ok;
+
+               bio_put(wbio);
+               sect_to_write -= sectors;
+               sector += sectors;
+               sectors = block_sectors;
+       }
+       return ok;
+}
+
 static void handle_read_error(mddev_t *mddev, r10bio_t *r10_bio)
 {
        int slot = r10_bio->read_slot;
@@ -1823,6 +2138,67 @@ read_more:
                generic_make_request(bio);
 }
 
+static void handle_write_completed(conf_t *conf, r10bio_t *r10_bio)
+{
+       /* Some sort of write request has finished and it
+        * succeeded in writing where we thought there was a
+        * bad block.  So forget the bad block.
+        * Or possibly if failed and we need to record
+        * a bad block.
+        */
+       int m;
+       mdk_rdev_t *rdev;
+
+       if (test_bit(R10BIO_IsSync, &r10_bio->state) ||
+           test_bit(R10BIO_IsRecover, &r10_bio->state)) {
+               for (m = 0; m < conf->copies; m++) {
+                       int dev = r10_bio->devs[m].devnum;
+                       rdev = conf->mirrors[dev].rdev;
+                       if (r10_bio->devs[m].bio == NULL)
+                               continue;
+                       if (test_bit(BIO_UPTODATE,
+                                    &r10_bio->devs[m].bio->bi_flags)) {
+                               rdev_clear_badblocks(
+                                       rdev,
+                                       r10_bio->devs[m].addr,
+                                       r10_bio->sectors);
+                       } else {
+                               if (!rdev_set_badblocks(
+                                           rdev,
+                                           r10_bio->devs[m].addr,
+                                           r10_bio->sectors, 0))
+                                       md_error(conf->mddev, rdev);
+                       }
+               }
+               put_buf(r10_bio);
+       } else {
+               for (m = 0; m < conf->copies; m++) {
+                       int dev = r10_bio->devs[m].devnum;
+                       struct bio *bio = r10_bio->devs[m].bio;
+                       rdev = conf->mirrors[dev].rdev;
+                       if (bio == IO_MADE_GOOD) {
+                               rdev_clear_badblocks(
+                                       rdev,
+                                       r10_bio->devs[m].addr,
+                                       r10_bio->sectors);
+                               rdev_dec_pending(rdev, conf->mddev);
+                       } else if (bio != NULL &&
+                                  !test_bit(BIO_UPTODATE, &bio->bi_flags)) {
+                               if (!narrow_write_error(r10_bio, m)) {
+                                       md_error(conf->mddev, rdev);
+                                       set_bit(R10BIO_Degraded,
+                                               &r10_bio->state);
+                               }
+                               rdev_dec_pending(rdev, conf->mddev);
+                       }
+               }
+               if (test_bit(R10BIO_WriteError,
+                            &r10_bio->state))
+                       close_write(r10_bio);
+               raid_end_bio_io(r10_bio);
+       }
+}
+
 static void raid10d(mddev_t *mddev)
 {
        r10bio_t *r10_bio;
@@ -1850,7 +2226,10 @@ static void raid10d(mddev_t *mddev)
 
                mddev = r10_bio->mddev;
                conf = mddev->private;
-               if (test_bit(R10BIO_IsSync, &r10_bio->state))
+               if (test_bit(R10BIO_MadeGood, &r10_bio->state) ||
+                   test_bit(R10BIO_WriteError, &r10_bio->state))
+                       handle_write_completed(conf, r10_bio);
+               else if (test_bit(R10BIO_IsSync, &r10_bio->state))
                        sync_request_write(mddev, r10_bio);
                else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
                        recovery_request_write(mddev, r10_bio);
@@ -1927,7 +2306,6 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
        int i;
        int max_sync;
        sector_t sync_blocks;
-
        sector_t sectors_skipped = 0;
        int chunks_skipped = 0;
 
@@ -2009,7 +2387,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
        max_sync = RESYNC_PAGES << (PAGE_SHIFT-9);
        if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
                /* recovery... the complicated one */
-               int j, k;
+               int j;
                r10_bio = NULL;
 
                for (i=0 ; i<conf->raid_disks; i++) {
@@ -2017,6 +2395,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
                        r10bio_t *rb2;
                        sector_t sect;
                        int must_sync;
+                       int any_working;
 
                        if (conf->mirrors[i].rdev == NULL ||
                            test_bit(In_sync, &conf->mirrors[i].rdev->flags)) 
@@ -2068,19 +2447,42 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
                        must_sync = bitmap_start_sync(mddev->bitmap, sect,
                                                      &sync_blocks, still_degraded);
 
+                       any_working = 0;
                        for (j=0; j<conf->copies;j++) {
+                               int k;
                                int d = r10_bio->devs[j].devnum;
+                               sector_t from_addr, to_addr;
+                               mdk_rdev_t *rdev;
+                               sector_t sector, first_bad;
+                               int bad_sectors;
                                if (!conf->mirrors[d].rdev ||
                                    !test_bit(In_sync, &conf->mirrors[d].rdev->flags))
                                        continue;
                                /* This is where we read from */
+                               any_working = 1;
+                               rdev = conf->mirrors[d].rdev;
+                               sector = r10_bio->devs[j].addr;
+
+                               if (is_badblock(rdev, sector, max_sync,
+                                               &first_bad, &bad_sectors)) {
+                                       if (first_bad > sector)
+                                               max_sync = first_bad - sector;
+                                       else {
+                                               bad_sectors -= (sector
+                                                               - first_bad);
+                                               if (max_sync > bad_sectors)
+                                                       max_sync = bad_sectors;
+                                               continue;
+                                       }
+                               }
                                bio = r10_bio->devs[0].bio;
                                bio->bi_next = biolist;
                                biolist = bio;
                                bio->bi_private = r10_bio;
                                bio->bi_end_io = end_sync_read;
                                bio->bi_rw = READ;
-                               bio->bi_sector = r10_bio->devs[j].addr +
+                               from_addr = r10_bio->devs[j].addr;
+                               bio->bi_sector = from_addr +
                                        conf->mirrors[d].rdev->data_offset;
                                bio->bi_bdev = conf->mirrors[d].rdev->bdev;
                                atomic_inc(&conf->mirrors[d].rdev->nr_pending);
@@ -2097,26 +2499,48 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
                                bio->bi_private = r10_bio;
                                bio->bi_end_io = end_sync_write;
                                bio->bi_rw = WRITE;
-                               bio->bi_sector = r10_bio->devs[k].addr +
+                               to_addr = r10_bio->devs[k].addr;
+                               bio->bi_sector = to_addr +
                                        conf->mirrors[i].rdev->data_offset;
                                bio->bi_bdev = conf->mirrors[i].rdev->bdev;
 
                                r10_bio->devs[0].devnum = d;
+                               r10_bio->devs[0].addr = from_addr;
                                r10_bio->devs[1].devnum = i;
+                               r10_bio->devs[1].addr = to_addr;
 
                                break;
                        }
                        if (j == conf->copies) {
-                               /* Cannot recover, so abort the recovery */
+                               /* Cannot recover, so abort the recovery or
+                                * record a bad block */
                                put_buf(r10_bio);
                                if (rb2)
                                        atomic_dec(&rb2->remaining);
                                r10_bio = rb2;
-                               if (!test_and_set_bit(MD_RECOVERY_INTR,
-                                                     &mddev->recovery))
-                                       printk(KERN_INFO "md/raid10:%s: insufficient "
-                                              "working devices for recovery.\n",
-                                              mdname(mddev));
+                               if (any_working) {
+                                       /* problem is that there are bad blocks
+                                        * on other device(s)
+                                        */
+                                       int k;
+                                       for (k = 0; k < conf->copies; k++)
+                                               if (r10_bio->devs[k].devnum == i)
+                                                       break;
+                                       if (!rdev_set_badblocks(
+                                                   conf->mirrors[i].rdev,
+                                                   r10_bio->devs[k].addr,
+                                                   max_sync, 0))
+                                               any_working = 0;
+                               }
+                               if (!any_working)  {
+                                       if (!test_and_set_bit(MD_RECOVERY_INTR,
+                                                             &mddev->recovery))
+                                               printk(KERN_INFO "md/raid10:%s: insufficient "
+                                                      "working devices for recovery.\n",
+                                                      mdname(mddev));
+                                       conf->mirrors[i].recovery_disabled
+                                               = mddev->recovery_disabled;
+                               }
                                break;
                        }
                }
@@ -2160,12 +2584,28 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
 
                for (i=0; i<conf->copies; i++) {
                        int d = r10_bio->devs[i].devnum;
+                       sector_t first_bad, sector;
+                       int bad_sectors;
+
                        bio = r10_bio->devs[i].bio;
                        bio->bi_end_io = NULL;
                        clear_bit(BIO_UPTODATE, &bio->bi_flags);
                        if (conf->mirrors[d].rdev == NULL ||
                            test_bit(Faulty, &conf->mirrors[d].rdev->flags))
                                continue;
+                       sector = r10_bio->devs[i].addr;
+                       if (is_badblock(conf->mirrors[d].rdev,
+                                       sector, max_sync,
+                                       &first_bad, &bad_sectors)) {
+                               if (first_bad > sector)
+                                       max_sync = first_bad - sector;
+                               else {
+                                       bad_sectors -= (sector - first_bad);
+                                       if (max_sync > bad_sectors)
+                                               max_sync = max_sync;
+                                       continue;
+                               }
+                       }
                        atomic_inc(&conf->mirrors[d].rdev->nr_pending);
                        atomic_inc(&r10_bio->remaining);
                        bio->bi_next = biolist;
@@ -2173,7 +2613,7 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
                        bio->bi_private = r10_bio;
                        bio->bi_end_io = end_sync_read;
                        bio->bi_rw = READ;
-                       bio->bi_sector = r10_bio->devs[i].addr +
+                       bio->bi_sector = sector +
                                conf->mirrors[d].rdev->data_offset;
                        bio->bi_bdev = conf->mirrors[d].rdev->bdev;
                        count++;
@@ -2260,7 +2700,8 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr,
        return sectors_skipped + nr_sectors;
  giveup:
        /* There is nowhere to write, so all non-sync
-        * drives must be failed, so try the next chunk...
+        * drives must be failed or in resync, all drives
+        * have a bad block, so try the next chunk...
         */
        if (sector_nr + max_sync < max_sector)
                max_sector = sector_nr + max_sync;
@@ -2431,10 +2872,6 @@ static int run(mddev_t *mddev)
 
        list_for_each_entry(rdev, &mddev->disks, same_set) {
 
-               if (rdev->badblocks.count) {
-                       printk(KERN_ERR "md/raid10: cannot handle bad blocks yet\n");
-                       goto out_free_conf;
-               }
                disk_idx = rdev->raid_disk;
                if (disk_idx >= conf->raid_disks
                    || disk_idx < 0)