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>

1 files changed, 28 insertions, 20 deletions

diff --git a/drivers/md/dm-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 624fe4319b24..9364a02e1646 100644
--- 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;