1 files changed, 49 insertions, 1 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e990d2d1ba4a..1efeda3b2f6f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -440,7 +440,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
          * allocate blocks for the tree root we can't do the fast caching since
          * we likely hold important locks.
          */
-        if (!trans->transaction->in_commit &&
+        if (trans && (!trans->transaction->in_commit) &&
             (root && root != root->fs_info->tree_root)) {
                 spin_lock(&cache->lock);
                 if (cache->cached != BTRFS_CACHE_NO) {
@@ -8778,3 +8778,51 @@ int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
 {
         return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
 }
+
+int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
+{
+        struct btrfs_fs_info *fs_info = root->fs_info;
+        struct btrfs_block_group_cache *cache = NULL;
+        u64 group_trimmed;
+        u64 start;
+        u64 end;
+        u64 trimmed = 0;
+        int ret = 0;
+
+        cache = btrfs_lookup_block_group(fs_info, range->start);
+
+        while (cache) {
+                if (cache->key.objectid >= (range->start + range->len)) {
+                        btrfs_put_block_group(cache);
+                        break;
+                }
+
+                start = max(range->start, cache->key.objectid);
+                end = min(range->start + range->len,
+                                cache->key.objectid + cache->key.offset);
+
+                if (end - start >= range->minlen) {
+                        if (!block_group_cache_done(cache)) {
+                                ret = cache_block_group(cache, NULL, root, 0);
+                                if (!ret)
+                                        wait_block_group_cache_done(cache);
+                        }
+                        ret = btrfs_trim_block_group(cache,
+                                                     &group_trimmed,
+                                                     start,
+                                                     end,
+                                                     range->minlen);
+
+                        trimmed += group_trimmed;
+                        if (ret) {
+                                btrfs_put_block_group(cache);
+                                break;
+                        }
+                }
+
+                cache = next_block_group(fs_info->tree_root, cache);
+        }
+
+        range->len = trimmed;
+        return ret;
+}