md/raid10: handle recovery of replacement devices.

If there is a replacement device, then recover to it,
reading from any drives - maybe the one being replaced, maybe not.

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

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 8a6862b..403f05a 100644 (file)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1843,7 +1843,7 @@ static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
 {
        struct r10conf *conf = mddev->private;
        int d;
-       struct bio *wbio;
+       struct bio *wbio, *wbio2;
 
        if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) {
                fix_recovery_read_error(r10_bio);
@@ -1855,12 +1855,20 @@ static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio)
         * share the pages with the first bio
         * and submit the write request
         */
-       wbio = r10_bio->devs[1].bio;
        d = r10_bio->devs[1].devnum;
-
-       atomic_inc(&conf->mirrors[d].rdev->nr_pending);
-       md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
-       generic_make_request(wbio);
+       wbio = r10_bio->devs[1].bio;
+       wbio2 = r10_bio->devs[1].repl_bio;
+       if (wbio->bi_end_io) {
+               atomic_inc(&conf->mirrors[d].rdev->nr_pending);
+               md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9);
+               generic_make_request(wbio);
+       }
+       if (wbio2 && wbio2->bi_end_io) {
+               atomic_inc(&conf->mirrors[d].replacement->nr_pending);
+               md_sync_acct(conf->mirrors[d].replacement->bdev,
+                            wbio2->bi_size >> 9);
+               generic_make_request(wbio2);
+       }
 }
 
 
@@ -2590,23 +2598,30 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
                        sector_t sect;
                        int must_sync;
                        int any_working;
-
-                       if (conf->mirrors[i].rdev == NULL ||
-                           test_bit(In_sync, &conf->mirrors[i].rdev->flags)) 
+                       struct mirror_info *mirror = &conf->mirrors[i];
+
+                       if ((mirror->rdev == NULL ||
+                            test_bit(In_sync, &mirror->rdev->flags))
+                           &&
+                           (mirror->replacement == NULL ||
+                            test_bit(Faulty,
+                                     &mirror->replacement->flags)))
                                continue;
 
                        still_degraded = 0;
                        /* want to reconstruct this device */
                        rb2 = r10_bio;
                        sect = raid10_find_virt(conf, sector_nr, i);
-                       /* Unless we are doing a full sync, we only need
-                        * to recover the block if it is set in the bitmap
+                       /* Unless we are doing a full sync, or a replacement
+                        * we only need to recover the block if it is set in
+                        * the bitmap
                         */
                        must_sync = bitmap_start_sync(mddev->bitmap, sect,
                                                      &sync_blocks, 1);
                        if (sync_blocks < max_sync)
                                max_sync = sync_blocks;
                        if (!must_sync &&
+                           mirror->replacement == NULL &&
                            !conf->fullsync) {
                                /* yep, skip the sync_blocks here, but don't assume
                                 * that there will never be anything to do here
@@ -2676,33 +2691,60 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
                                bio->bi_end_io = end_sync_read;
                                bio->bi_rw = READ;
                                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);
-                               atomic_inc(&r10_bio->remaining);
-                               /* and we write to 'i' */
+                               bio->bi_sector = from_addr + rdev->data_offset;
+                               bio->bi_bdev = rdev->bdev;
+                               atomic_inc(&rdev->nr_pending);
+                               /* and we write to 'i' (if not in_sync) */
 
                                for (k=0; k<conf->copies; k++)
                                        if (r10_bio->devs[k].devnum == i)
                                                break;
                                BUG_ON(k == conf->copies);
-                               bio = r10_bio->devs[1].bio;
-                               bio->bi_next = biolist;
-                               biolist = bio;
-                               bio->bi_private = r10_bio;
-                               bio->bi_end_io = end_sync_write;
-                               bio->bi_rw = WRITE;
                                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;
 
+                               rdev = mirror->rdev;
+                               if (!test_bit(In_sync, &rdev->flags)) {
+                                       bio = r10_bio->devs[1].bio;
+                                       bio->bi_next = biolist;
+                                       biolist = bio;
+                                       bio->bi_private = r10_bio;
+                                       bio->bi_end_io = end_sync_write;
+                                       bio->bi_rw = WRITE;
+                                       bio->bi_sector = to_addr
+                                               + rdev->data_offset;
+                                       bio->bi_bdev = rdev->bdev;
+                                       atomic_inc(&r10_bio->remaining);
+                               } else
+                                       r10_bio->devs[1].bio->bi_end_io = NULL;
+
+                               /* and maybe write to replacement */
+                               bio = r10_bio->devs[1].repl_bio;
+                               if (bio)
+                                       bio->bi_end_io = NULL;
+                               rdev = mirror->replacement;
+                               /* Note: if rdev != NULL, then bio
+                                * cannot be NULL as r10buf_pool_alloc will
+                                * have allocated it.
+                                * So the second test here is pointless.
+                                * But it keeps semantic-checkers happy, and
+                                * this comment keeps human reviewers
+                                * happy.
+                                */
+                               if (rdev == NULL || bio == NULL ||
+                                   test_bit(Faulty, &rdev->flags))
+                                       break;
+                               bio->bi_next = biolist;
+                               biolist = bio;
+                               bio->bi_private = r10_bio;
+                               bio->bi_end_io = end_sync_write;
+                               bio->bi_rw = WRITE;
+                               bio->bi_sector = to_addr + rdev->data_offset;
+                               bio->bi_bdev = rdev->bdev;
+                               atomic_inc(&r10_bio->remaining);
                                break;
                        }
                        if (j == conf->copies) {
@@ -2720,8 +2762,16 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
                                        for (k = 0; k < conf->copies; k++)
                                                if (r10_bio->devs[k].devnum == i)
                                                        break;
-                                       if (!rdev_set_badblocks(
-                                                   conf->mirrors[i].rdev,
+                                       if (!test_bit(In_sync,
+                                                     &mirror->rdev->flags)
+                                           && !rdev_set_badblocks(
+                                                   mirror->rdev,
+                                                   r10_bio->devs[k].addr,
+                                                   max_sync, 0))
+                                               any_working = 0;
+                                       if (mirror->replacement &&
+                                           !rdev_set_badblocks(
+                                                   mirror->replacement,
                                                    r10_bio->devs[k].addr,
                                                    max_sync, 0))
                                                any_working = 0;
@@ -2732,7 +2782,7 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr,
                                                printk(KERN_INFO "md/raid10:%s: insufficient "
                                                       "working devices for recovery.\n",
                                                       mdname(mddev));
-                                       conf->mirrors[i].recovery_disabled
+                                       mirror->recovery_disabled
                                                = mddev->recovery_disabled;
                                }
                                break;