imsm: enable checkpointing of migration (resync/rebuild)

When the array is shutdown, or when mdadm --wait-clean is called, any
active resync process will be idled allowing mdmon to record the current
resync position.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/super-intel.c b/super-intel.c
index 7e1f986ba7d3026ca6aae4baaea471b42e4e7715..80427e4a7c25d29e8e0e2e5771b9ddfa31f04451 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -77,7 +77,8 @@ struct imsm_map {
 } __attribute__ ((packed));
 
 struct imsm_vol {
-       __u32 reserved[2];
+       __u32 curr_migr_unit;
+       __u32 reserved;
        __u8  migr_state;       /* Normal or Migrating */
        __u8  migr_type;        /* Initializing, Rebuilding, ... */
        __u8  dirty;
@@ -751,9 +752,10 @@ static void getinfo_super_imsm_volume(struct supertype *st, struct mdinfo *info)
        info->component_size      = __le32_to_cpu(map->blocks_per_member);
        memset(info->uuid, 0, sizeof(info->uuid));
 
-       if (map->map_state == IMSM_T_STATE_UNINITIALIZED ||
-           dev->vol.dirty || dev->vol.migr_state)
+       if (map->map_state == IMSM_T_STATE_UNINITIALIZED || dev->vol.dirty)
                info->resync_start = 0;
+       else if (dev->vol.migr_state)
+               info->resync_start = __le32_to_cpu(dev->vol.curr_migr_unit);
        else
                info->resync_start = ~0ULL;
 
@@ -1127,11 +1129,21 @@ static void migrate(struct imsm_dev *dev, __u8 to_state, int rebuild_resync)
 
        dev->vol.migr_state = 1;
        dev->vol.migr_type = rebuild_resync;
+       dev->vol.curr_migr_unit = 0;
        dest = get_imsm_map(dev, 1);
 
        memcpy(dest, src, sizeof_imsm_map(src));
        src->map_state = to_state;
 }
+
+static void end_migration(struct imsm_dev *dev, __u8 map_state)
+{
+       struct imsm_map *map = get_imsm_map(dev, 0);
+
+       dev->vol.migr_state = 0;
+       dev->vol.curr_migr_unit = 0;
+       map->map_state = map_state;
+}
 #endif
 
 static int parse_raid_devices(struct intel_super *super)
@@ -1602,6 +1614,7 @@ static int init_super_imsm_volume(struct supertype *st, mdu_array_info_t *info,
        vol->migr_state = 0;
        vol->migr_type = 0;
        vol->dirty = 0;
+       vol->curr_migr_unit = 0;
        for (i = 0; i < idx; i++) {
                struct imsm_dev *prev = get_imsm_dev(super, i);
                struct imsm_map *pmap = get_imsm_map(prev, 0);
@@ -2485,8 +2498,7 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
                 */
                if (is_resyncing(dev)) {
                        dprintf("imsm: mark resync done\n");
-                       dev->vol.migr_state = 0;
-                       map->map_state = map_state;
+                       end_migration(dev, map_state);
                        super->updates_pending++;
                }
        } else if (!is_resyncing(dev) && !failed) {
@@ -2498,6 +2510,14 @@ static int imsm_set_array_state(struct active_array *a, int consistent)
                super->updates_pending++;
        }
 
+       /* check if we can update the migration checkpoint */
+       if (dev->vol.migr_state &&
+           __le32_to_cpu(dev->vol.curr_migr_unit) != a->resync_start) {
+               dprintf("imsm: checkpoint migration (%llu)\n", a->resync_start);
+               dev->vol.curr_migr_unit = __cpu_to_le32(a->resync_start);
+               super->updates_pending++;
+       }
+
        /* mark dirty / clean */
        if (dev->vol.dirty != !consistent) {
                dprintf("imsm: mark '%s' (%llu)\n",
@@ -2557,8 +2577,7 @@ static void imsm_set_disk(struct active_array *a, int n, int state)
 
        /* check if recovery complete, newly degraded, or failed */
        if (map_state == IMSM_T_STATE_NORMAL && is_rebuilding(dev)) {
-               map->map_state = map_state;
-               dev->vol.migr_state = 0;
+               end_migration(dev, map_state);
                super->updates_pending++;
        } else if (map_state == IMSM_T_STATE_DEGRADED &&
                   map->map_state != map_state &&
@@ -2569,8 +2588,7 @@ static void imsm_set_disk(struct active_array *a, int n, int state)
        } else if (map_state == IMSM_T_STATE_FAILED &&
                   map->map_state != map_state) {
                dprintf("imsm: mark failed\n");
-               dev->vol.migr_state = 0;
-               map->map_state = map_state;
+               end_migration(dev, map_state);
                super->updates_pending++;
        }
 }