dm cache metadata: use bitset cursor api to load discard bitset

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 624fe4319b24ad0f338e912a07a5040ad91ad4c9..9364a02e1646f38f7df07e2c257d7118a7788e42 100644 (file)
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -995,14 +995,6 @@ static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b)
                                   from_dblock(b), &cmd->discard_root);
 }
 
-static int __is_discarded(struct dm_cache_metadata *cmd, dm_dblock_t b,
-                         bool *is_discarded)
-{
-       return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root,
-                                 from_dblock(b), &cmd->discard_root,
-                                 is_discarded);
-}
-
 static int __discard(struct dm_cache_metadata *cmd,
                     dm_dblock_t dblock, bool discard)
 {
@@ -1032,22 +1024,38 @@ static int __load_discards(struct dm_cache_metadata *cmd,
                           load_discard_fn fn, void *context)
 {
        int r = 0;
-       dm_block_t b;
-       bool discard;
+       uint32_t b;
+       struct dm_bitset_cursor c;
 
-       for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
-               dm_dblock_t dblock = to_dblock(b);
+       if (from_dblock(cmd->discard_nr_blocks) == 0)
+               /* nothing to do */
+               return 0;
 
-               if (cmd->clean_when_opened) {
-                       r = __is_discarded(cmd, dblock, &discard);
-                       if (r)
-                               return r;
-               } else
-                       discard = false;
+       if (cmd->clean_when_opened) {
+               r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root);
+               if (r)
+                       return r;
 
-               r = fn(context, cmd->discard_block_size, dblock, discard);
+               r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root,
+                                          from_dblock(cmd->discard_nr_blocks), &c);
                if (r)
-                       break;
+                       return r;
+
+               for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
+                       r = fn(context, cmd->discard_block_size, to_dblock(b),
+                              dm_bitset_cursor_get_value(&c));
+                       if (r)
+                               break;
+               }
+
+               dm_bitset_cursor_end(&c);
+
+       } else {
+               for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) {
+                       r = fn(context, cmd->discard_block_size, to_dblock(b), false);
+                       if (r)
+                               return r;
+               }
        }
 
        return r;