dm raid: support delta_disks for raid1, fix table output

Add "delta_disks" constructor argument support to raid1 to allow for
consistent userspace disk addition/removal handling.

Fix raid_status() to report all raid disks with status and table output
on disk adding reshapes, not just the ones listed on the mddev; optimize
its rebuild and writemostly output.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index 473c6d9..4caf51f 100644 (file)
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -132,6 +132,7 @@ struct raid_dev {
                                 CTR_FLAG_MAX_RECOVERY_RATE | \
                                 CTR_FLAG_MAX_WRITE_BEHIND | \
                                 CTR_FLAG_REGION_SIZE | \
+                                CTR_FLAG_DELTA_DISKS | \
                                 CTR_FLAG_DATA_OFFSET)
 
 /* "raid10" does not accept any raid1 or stripe cache options */
@@ -1714,9 +1715,13 @@ static bool rs_reshape_requested(struct raid_set *rs)
                 rs->delta_disks;
 
        /* Historical case to support raid1 reshape without delta disks */
-       if (mddev->level == 1)
+       if (mddev->level == 1) {
+               if (rs->delta_disks)
+                       return !!rs->delta_disks;
+
                return !change &&
                       mddev->raid_disks != rs->raid_disks;
+       }
 
        if (mddev->level == 10)
                return change &&
@@ -1837,8 +1842,8 @@ static int rs_check_reshape(struct raid_set *rs)
                rs->ti->error = "Convert request on recovering raid set prohibited";
        else if (rs_is_reshaping(rs))
                rs->ti->error = "raid set already reshaping!";
-       else if (!(rs_is_raid10(rs) || rs_is_raid456(rs)))
-               rs->ti->error = "Reshaping only supported for raid4/5/6/10";
+       else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
+               rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
        else
                return 0;
 
@@ -2566,16 +2571,17 @@ static int rs_prepare_reshape(struct raid_set *rs)
        } else if (rs_is_raid456(rs))
                reshape = true;
 
-       /*
-        * HM FIXME: process raid1 via delta_disks as well?
-        *           Would cause allocations in raid1->check_reshape
-        *           though, thus more issues with potential failures
-        */
        else if (rs_is_raid1(rs)) {
-               set_bit(RT_FLAG_KEEP_RS_FROZEN, &rs->runtime_flags);
-               mddev->raid_disks = rs->raid_disks;
-               reshape = false;
-
+               if (rs->delta_disks) {
+                       /* Process raid1 via delta_disks */
+                       mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
+                       reshape = true;
+               } else {
+                       /* Process raid1 without delta_disks */
+                       mddev->raid_disks = rs->raid_disks;
+                       set_bit(RT_FLAG_KEEP_RS_FROZEN, &rs->runtime_flags);
+                       reshape = false;
+               }
        } else {
                rs->ti->error = "Called with bogus raid type";
                return -EINVAL;
@@ -2585,12 +2591,9 @@ static int rs_prepare_reshape(struct raid_set *rs)
                set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
                set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
                set_bit(RT_FLAG_KEEP_RS_FROZEN, &rs->runtime_flags);
-       }
-       /* Create new superblocks and bitmaps, if any */
-       if (mddev->raid_disks < rs->raid_disks) {
+       } else if (mddev->raid_disks < rs->raid_disks)
+               /* Create new superblocks and bitmaps, if any new disks */
                set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
-               rs_set_cur(rs);
-       }
 
        return 0;
 }
@@ -2656,7 +2659,7 @@ static int rs_setup_reshape(struct raid_set *rs)
                        rdev->raid_disk = d;
 
                        rdev->sectors = mddev->dev_sectors;
-                       rdev->recovery_offset = MaxSector;
+                       rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
                }
 
                mddev->reshape_backwards = 0; /* adding disks -> forward reshape */
@@ -2971,10 +2974,12 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
                /* Restore new, ctr requested layout to perform check */
                rs_config_restore(rs, &rs_layout);
 
-               r = rs->md.pers->check_reshape(&rs->md);
-               if (r) {
-                       ti->error = "Reshape check failed";
-                       goto bad_check_reshape;
+               if (rs->md.pers->start_reshape) {
+                       r = rs->md.pers->check_reshape(&rs->md);
+                       if (r) {
+                               ti->error = "Reshape check failed";
+                               goto bad_check_reshape;
+                       }
                }
        }
 
@@ -3150,10 +3155,11 @@ static void raid_status(struct dm_target *ti, status_type_t type,
        struct raid_set *rs = ti->private;
        struct mddev *mddev = &rs->md;
        struct r5conf *conf = mddev->private;
-       int max_nr_stripes = conf ? conf->max_nr_stripes : 0;
+       int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
        bool array_in_sync;
        unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
        unsigned int sz = 0;
+       unsigned int rebuild_disks;
        unsigned int write_mostly_params = 0;
        sector_t progress, resync_max_sectors, resync_mismatches;
        const char *sync_action;
@@ -3181,7 +3187,8 @@ static void raid_status(struct dm_target *ti, status_type_t type,
 
                /* HM FIXME: do we want another state char for raid0? It shows 'D' or 'A' now */
                rdev_for_each(rdev, mddev)
-                       DMEMIT(__raid_dev_status(rdev, array_in_sync));
+               for (i = 0; i < rs->raid_disks; i++)
+                       DMEMIT(__raid_dev_status(&rs->dev[i].rdev, array_in_sync));
 
                /*
                 * In-sync/Reshape ratio:
@@ -3233,11 +3240,11 @@ static void raid_status(struct dm_target *ti, status_type_t type,
                /* Report the table line string you would use to construct this raid set */
 
                /* Calculate raid parameter count */
-               rdev_for_each(rdev, mddev)
-                       if (test_bit(WriteMostly, &rdev->flags))
+               for (i = 0; i < rs->raid_disks; i++)
+                       if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
                                write_mostly_params += 2;
-               raid_param_cnt += memweight(rs->rebuild_disks,
-                                           DISKS_ARRAY_ELEMS * sizeof(*rs->rebuild_disks)) * 2 +
+               rebuild_disks = memweight(rs->rebuild_disks, DISKS_ARRAY_ELEMS * sizeof(*rs->rebuild_disks));
+               raid_param_cnt += rebuild_disks * 2 +
                                  write_mostly_params +
                                  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
                                  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
@@ -3264,18 +3271,20 @@ static void raid_status(struct dm_target *ti, status_type_t type,
                                          mddev->bitmap_info.daemon_sleep);
                if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
-                                        mddev->delta_disks);
+                                        max(rs->delta_disks, mddev->delta_disks));
                if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
                                         max_nr_stripes);
-               rdev_for_each(rdev, mddev)
-                       if (test_bit(rdev->raid_disk, (void *) rs->rebuild_disks))
-                               DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD),
-                                                rdev->raid_disk);
-               rdev_for_each(rdev, mddev)
-                       if (test_bit(WriteMostly, &rdev->flags))
-                               DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
-                                                rdev->raid_disk);
+               if (rebuild_disks)
+                       for (i = 0; i < rs->raid_disks; i++)
+                               if (test_bit(rs->dev[i].rdev.raid_disk, (void *) rs->rebuild_disks))
+                                       DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD),
+                                                        rs->dev[i].rdev.raid_disk);
+               if (write_mostly_params)
+                       for (i = 0; i < rs->raid_disks; i++)
+                               if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
+                                       DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
+                                              rs->dev[i].rdev.raid_disk);
                if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
                        DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
                                          mddev->bitmap_info.max_write_behind);
@@ -3286,12 +3295,9 @@ static void raid_status(struct dm_target *ti, status_type_t type,
                        DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
                                         mddev->sync_speed_min);
                DMEMIT(" %d", rs->raid_disks);
-               rdev_for_each(rdev, mddev) {
-                       struct raid_dev *rd = container_of(rdev, struct raid_dev, rdev);
-
-                       DMEMIT(" %s %s", __get_dev_name(rd->meta_dev),
-                                        __get_dev_name(rd->data_dev));
-               }
+               for (i = 0; i < rs->raid_disks; i++)
+                       DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
+                                        __get_dev_name(rs->dev[i].data_dev));
        }
 }