dm thin metadata: add dm_thin_remove_range()

Removes a range of blocks from the btree.

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

2 files changed, 56 insertions, 0 deletions

diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 94cf0db8a22e..8b521e3e1e1b 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -1526,6 +1526,47 @@ static int __remove(struct dm_thin_device *td, dm_block_t block)
         return 0;
 }
 
+static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end)
+{
+        int r;
+        unsigned count;
+        struct dm_pool_metadata *pmd = td->pmd;
+        dm_block_t keys[1] = { td->id };
+        __le64 value;
+        dm_block_t mapping_root;
+
+        /*
+         * Find the mapping tree
+         */
+        r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value);
+        if (r)
+                return r;
+
+        /*
+         * Remove from the mapping tree, taking care to inc the
+         * ref count so it doesn't get deleted.
+         */
+        mapping_root = le64_to_cpu(value);
+        dm_tm_inc(pmd->tm, mapping_root);
+        r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root);
+        if (r)
+                return r;
+
+        r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count);
+        if (r)
+                return r;
+
+        td->mapped_blocks -= count;
+        td->changed = 1;
+
+        /*
+         * Reinsert the mapping tree.
+         */
+        value = cpu_to_le64(mapping_root);
+        __dm_bless_for_disk(&value);
+        return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root);
+}
+
 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
 {
         int r = -EINVAL;
@@ -1538,6 +1579,19 @@ int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
         return r;
 }
 
+int dm_thin_remove_range(struct dm_thin_device *td,
+                         dm_block_t begin, dm_block_t end)
+{
+        int r = -EINVAL;
+
+        down_write(&td->pmd->root_lock);
+        if (!td->pmd->fail_io)
+                r = __remove_range(td, begin, end);
+        up_write(&td->pmd->root_lock);
+
+        return r;
+}
+
 int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result)
 {
         int r;
diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h
index f11f14095b93..a938babe4258 100644
--- a/drivers/md/dm-thin-metadata.h
+++ b/drivers/md/dm-thin-metadata.h
@@ -167,6 +167,8 @@ int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
                          dm_block_t data_block);
 
 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block);
+int dm_thin_remove_range(struct dm_thin_device *td,
+                         dm_block_t begin, dm_block_t end);
 
 /*
  * Queries.