3 files changed, 59 insertions, 8 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 227620993bce..f63c9b3f6e08 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2156,6 +2156,9 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
                              u64 num_bytes, u64 *refs, u64 *flags);
 int btrfs_pin_extent(struct btrfs_root *root,
                      u64 bytenr, u64 num, int reserved);
+int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
+                                    struct btrfs_root *root,
+                                    u64 bytenr, u64 num_bytes);
 int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans,
                           struct btrfs_root *root,
                           u64 objectid, u64 offset, u64 bytenr);
@@ -2206,6 +2209,8 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans,
                       u64 root_objectid, u64 owner, u64 offset);
 
 int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len);
+int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
+                                       u64 start, u64 len);
 int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
                                 struct btrfs_root *root);
 int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 28c4809851a5..cb7626646bba 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4344,6 +4344,34 @@ int btrfs_pin_extent(struct btrfs_root *root,
         return 0;
 }
 
+/*
+ * this function must be called within transaction
+ */
+int btrfs_pin_extent_for_log_replay(struct btrfs_trans_handle *trans,
+                                    struct btrfs_root *root,
+                                    u64 bytenr, u64 num_bytes)
+{
+        struct btrfs_block_group_cache *cache;
+
+        cache = btrfs_lookup_block_group(root->fs_info, bytenr);
+        BUG_ON(!cache);
+
+        /*
+         * pull in the free space cache (if any) so that our pin
+         * removes the free space from the cache.  We have load_only set
+         * to one because the slow code to read in the free extents does check
+         * the pinned extents.
+         */
+        cache_block_group(cache, trans, root, 1);
+
+        pin_down_extent(root, cache, bytenr, num_bytes, 0);
+
+        /* remove us from the free space cache (if we're there at all) */
+        btrfs_remove_free_space(cache, bytenr, num_bytes);
+        btrfs_put_block_group(cache);
+        return 0;
+}
+
 /**
  * btrfs_update_reserved_bytes - update the block_group and space info counters
  * @cache:      The cache we are manipulating
@@ -5487,7 +5515,8 @@ again:
         return ret;
 }
 
-int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
+static int __btrfs_free_reserved_extent(struct btrfs_root *root,
+                                        u64 start, u64 len, int pin)
 {
         struct btrfs_block_group_cache *cache;
         int ret = 0;
@@ -5502,8 +5531,12 @@ int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
         if (btrfs_test_opt(root, DISCARD))
                 ret = btrfs_discard_extent(root, start, len, NULL);
 
-        btrfs_add_free_space(cache, start, len);
-        btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
+        if (pin)
+                pin_down_extent(root, cache, start, len, 1);
+        else {
+                btrfs_add_free_space(cache, start, len);
+                btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
+        }
         btrfs_put_block_group(cache);
 
         trace_btrfs_reserved_extent_free(root, start, len);
@@ -5511,6 +5544,18 @@ int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len)
         return ret;
 }
 
+int btrfs_free_reserved_extent(struct btrfs_root *root,
+                                        u64 start, u64 len)
+{
+        return __btrfs_free_reserved_extent(root, start, len, 0);
+}
+
+int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root,
+                                       u64 start, u64 len)
+{
+        return __btrfs_free_reserved_extent(root, start, len, 1);
+}
+
 static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
                                       struct btrfs_root *root,
                                       u64 parent, u64 root_objectid,
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 310ab22cfe58..8ca1b6b83bd1 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -276,8 +276,9 @@ static int process_one_buffer(struct btrfs_root *log,
                               struct walk_control *wc, u64 gen)
 {
         if (wc->pin)
-                btrfs_pin_extent(log->fs_info->extent_root,
-                                 eb->start, eb->len, 0);
+                btrfs_pin_extent_for_log_replay(wc->trans,
+                                                log->fs_info->extent_root,
+                                                eb->start, eb->len);
 
         if (btrfs_buffer_uptodate(eb, gen)) {
                 if (wc->write)
@@ -1760,7 +1761,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 
                                 WARN_ON(root_owner !=
                                         BTRFS_TREE_LOG_OBJECTID);
-                                ret = btrfs_free_reserved_extent(root,
+                                ret = btrfs_free_and_pin_reserved_extent(root,
                                                          bytenr, blocksize);
                                 BUG_ON(ret);
                         }
@@ -1828,7 +1829,7 @@ static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
                                 btrfs_tree_unlock(next);
 
                                 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
-                                ret = btrfs_free_reserved_extent(root,
+                                ret = btrfs_free_and_pin_reserved_extent(root,
                                                 path->nodes[*level]->start,
                                                 path->nodes[*level]->len);
                                 BUG_ON(ret);
@@ -1897,7 +1898,7 @@ static int walk_log_tree(struct btrfs_trans_handle *trans,
 
                         WARN_ON(log->root_key.objectid !=
                                 BTRFS_TREE_LOG_OBJECTID);
-                        ret = btrfs_free_reserved_extent(log, next->start,
+                        ret = btrfs_free_and_pin_reserved_extent(log, next->start,
                                                          next->len);
                         BUG_ON(ret);
                 }