imsm: fix num_data_stripes after raid0 takeover

After raid1 to raid0 migration num_data_stripes value is
incorrect because was additionally divided by 2.

Create dedicated setters for num_data_stripes and num_domains
and propagate it across the code to unify alghoritms and
eliminate similar mistakes.

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

diff --git a/super-intel.c b/super-intel.c
index da376251ce4e4eea5368afef11ebee49e1857e8e..afb0fca7ee37c160a1654fb6e238941dd0e952c7 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -1228,6 +1228,33 @@ static unsigned long long total_blocks(struct imsm_disk *disk)
        return join_u32(disk->total_blocks_lo, disk->total_blocks_hi);
 }
 
+/**
+ * imsm_num_data_members() - get data drives count for an array.
+ * @map: Map to analyze.
+ *
+ * num_data_members value represents minimal count of drives for level.
+ * The name of the property could be misleading for RAID5 with asymmetric layout
+ * because some data required to be calculated from parity.
+ * The property is extracted from level and num_members value.
+ *
+ * Return: num_data_members value on success, zero otherwise.
+ */
+static __u8 imsm_num_data_members(struct imsm_map *map)
+{
+       switch (get_imsm_raid_level(map)) {
+       case 0:
+               return map->num_members;
+       case 1:
+       case 10:
+               return map->num_members / 2;
+       case 5:
+               return map->num_members - 1;
+       default:
+               dprintf("unsupported raid level\n");
+               return 0;
+       }
+}
+
 static unsigned long long pba_of_lba0(struct imsm_map *map)
 {
        if (map == NULL)
@@ -1301,6 +1328,24 @@ static void set_total_blocks(struct imsm_disk *disk, unsigned long long n)
        split_ull(n, &disk->total_blocks_lo, &disk->total_blocks_hi);
 }
 
+/**
+ * set_num_domains() - Set number of domains for an array.
+ * @map: Map to be updated.
+ *
+ * num_domains property represents copies count of each data drive, thus make
+ * it meaningful only for RAID1 and RAID10. IMSM supports two domains for
+ * raid1 and raid10.
+ */
+static void set_num_domains(struct imsm_map *map)
+{
+       int level = get_imsm_raid_level(map);
+
+       if (level == 1 || level == 10)
+               map->num_domains = 2;
+       else
+               map->num_domains = 1;
+}
+
 static void set_pba_of_lba0(struct imsm_map *map, unsigned long long n)
 {
        split_ull(n, &map->pba_of_lba0_lo, &map->pba_of_lba0_hi);
@@ -1316,6 +1361,24 @@ static void set_num_data_stripes(struct imsm_map *map, unsigned long long n)
        split_ull(n, &map->num_data_stripes_lo, &map->num_data_stripes_hi);
 }
 
+/**
+ * update_num_data_stripes() - Calculate and update num_data_stripes value.
+ * @map: map to be updated.
+ * @dev_size: size of volume.
+ *
+ * num_data_stripes value is addictionally divided by num_domains, therefore for
+ * levels where num_domains is not 1, nds is a part of real value.
+ */
+static void update_num_data_stripes(struct imsm_map *map,
+                                    unsigned long long dev_size)
+{
+       unsigned long long nds = dev_size / imsm_num_data_members(map);
+
+       nds /= map->num_domains;
+       nds /= map->blocks_per_strip;
+       set_num_data_stripes(map, nds);
+}
+
 static void set_vol_curr_migr_unit(struct imsm_dev *dev, unsigned long long n)
 {
        if (dev == NULL)
@@ -2872,26 +2935,6 @@ static __u32 num_stripes_per_unit_rebuild(struct imsm_dev *dev)
                return num_stripes_per_unit_resync(dev);
 }
 
-static __u8 imsm_num_data_members(struct imsm_map *map)
-{
-       /* named 'imsm_' because raid0, raid1 and raid10
-        * counter-intuitively have the same number of data disks
-        */
-       switch (get_imsm_raid_level(map)) {
-       case 0:
-               return map->num_members;
-               break;
-       case 1:
-       case 10:
-               return map->num_members/2;
-       case 5:
-               return map->num_members - 1;
-       default:
-               dprintf("unsupported raid level\n");
-               return 0;
-       }
-}
-
 static unsigned long long calc_component_size(struct imsm_map *map,
                                              struct imsm_dev *dev)
 {
@@ -5433,7 +5476,6 @@ static int init_super_imsm_volume(struct supertype *st, mdu_array_info_t *info,
        int namelen;
        unsigned long long array_blocks;
        size_t size_old, size_new;
-       unsigned long long num_data_stripes;
        unsigned int data_disks;
        unsigned long long size_per_member;
 
@@ -5551,18 +5593,9 @@ static int init_super_imsm_volume(struct supertype *st, mdu_array_info_t *info,
        }
 
        map->raid_level = info->level;
-       if (info->level == 10) {
+       if (info->level == 10)
                map->raid_level = 1;
-               map->num_domains = info->raid_disks / 2;
-       } else if (info->level == 1)
-               map->num_domains = info->raid_disks;
-       else
-               map->num_domains = 1;
-
-       /* info->size is only int so use the 'size' parameter instead */
-       num_data_stripes = size_per_member / info_to_blocks_per_strip(info);
-       num_data_stripes /= map->num_domains;
-       set_num_data_stripes(map, num_data_stripes);
+       set_num_domains(map);
 
        size_per_member += NUM_BLOCKS_DIRTY_STRIPE_REGION;
        set_blocks_per_member(map, info_to_blocks_per_member(info,
@@ -5570,6 +5603,7 @@ static int init_super_imsm_volume(struct supertype *st, mdu_array_info_t *info,
                                                             BLOCKS_PER_KB));
 
        map->num_members = info->raid_disks;
+       update_num_data_stripes(map, array_blocks);
        for (i = 0; i < map->num_members; i++) {
                /* initialized in add_to_super */
                set_imsm_ord_tbl_ent(map, i, IMSM_ORD_REBUILD);
@@ -9384,7 +9418,6 @@ static int apply_reshape_migration_update(struct imsm_update_reshape_migration *
                        /* update chunk size
                         */
                        if (u->new_chunksize > 0) {
-                               unsigned long long num_data_stripes;
                                struct imsm_map *dest_map =
                                        get_imsm_map(dev, MAP_0);
                                int used_disks =
@@ -9395,11 +9428,7 @@ static int apply_reshape_migration_update(struct imsm_update_reshape_migration *
 
                                map->blocks_per_strip =
                                        __cpu_to_le16(u->new_chunksize * 2);
-                               num_data_stripes =
-                                       imsm_dev_size(dev) / used_disks;
-                               num_data_stripes /= map->blocks_per_strip;
-                               num_data_stripes /= map->num_domains;
-                               set_num_data_stripes(map, num_data_stripes);
+                               update_num_data_stripes(map, imsm_dev_size(dev));
                        }
 
                        /* ensure blocks_per_member has valid value
@@ -9473,7 +9502,6 @@ static int apply_size_change_update(struct imsm_update_size_change *u,
                        struct imsm_map *map = get_imsm_map(dev, MAP_0);
                        int used_disks = imsm_num_data_members(map);
                        unsigned long long blocks_per_member;
-                       unsigned long long num_data_stripes;
                        unsigned long long new_size_per_disk;
 
                        if (used_disks == 0)
@@ -9484,16 +9512,10 @@ static int apply_size_change_update(struct imsm_update_size_change *u,
                        new_size_per_disk = u->new_size / used_disks;
                        blocks_per_member = new_size_per_disk +
                                            NUM_BLOCKS_DIRTY_STRIPE_REGION;
-                       num_data_stripes = new_size_per_disk /
-                                          map->blocks_per_strip;
-                       num_data_stripes /= map->num_domains;
-                       dprintf("(size: %llu, blocks per member: %llu, num_data_stipes: %llu)\n",
-                               u->new_size, new_size_per_disk,
-                               num_data_stripes);
-                       set_blocks_per_member(map, blocks_per_member);
-                       set_num_data_stripes(map, num_data_stripes);
-                       imsm_set_array_size(dev, u->new_size);
 
+                       imsm_set_array_size(dev, u->new_size);
+                       set_blocks_per_member(map, blocks_per_member);
+                       update_num_data_stripes(map, u->new_size);
                        ret_val = 1;
                        break;
                }
@@ -9775,8 +9797,6 @@ static int apply_takeover_update(struct imsm_update_takeover *u,
        map = get_imsm_map(dev, MAP_0);
 
        if (u->direction == R10_TO_R0) {
-               unsigned long long num_data_stripes;
-
                /* Number of failed disks must be half of initial disk number */
                if (imsm_count_failed(super, dev, MAP_0) !=
                                (map->num_members / 2))
@@ -9797,19 +9817,16 @@ static int apply_takeover_update(struct imsm_update_takeover *u,
                        }
                }
                /* update map */
-               map->num_members = map->num_members / 2;
+               map->num_members /= map->num_domains;
                map->map_state = IMSM_T_STATE_NORMAL;
-               map->num_domains = 1;
                map->raid_level = 0;
+               set_num_domains(map);
+               update_num_data_stripes(map, imsm_dev_size(dev));
                map->failed_disk_num = -1;
-               num_data_stripes = imsm_dev_size(dev) / 2;
-               num_data_stripes /= map->blocks_per_strip;
-               set_num_data_stripes(map, num_data_stripes);
        }
 
        if (u->direction == R0_TO_R10) {
                void **space;
-               unsigned long long num_data_stripes;
 
                /* update slots in current disk list */
                for (dm = super->disks; dm; dm = dm->next) {
@@ -9844,14 +9861,12 @@ static int apply_takeover_update(struct imsm_update_takeover *u,
                memcpy(dev_new, dev, sizeof(*dev));
                /* update new map */
                map = get_imsm_map(dev_new, MAP_0);
-               map->num_members = map->num_members * 2;
+
                map->map_state = IMSM_T_STATE_DEGRADED;
-               map->num_domains = 2;
                map->raid_level = 1;
-               num_data_stripes = imsm_dev_size(dev) / 2;
-               num_data_stripes /= map->blocks_per_strip;
-               num_data_stripes /= map->num_domains;
-               set_num_data_stripes(map, num_data_stripes);
+               set_num_domains(map);
+               map->num_members = map->num_members * map->num_domains;
+               update_num_data_stripes(map, imsm_dev_size(dev));
 
                /* replace dev<->dev_new */
                dv->dev = dev_new;