btrfs: Introduce unaccount_log_buffer

This function correctly adjusts the reserved bytes occupied by a log
tree extent buffer. It will be used instead of calling
btrfs_pin_reserved_extent.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 4ea47ba..32b087f 100644 (file)
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -18,6 +18,8 @@
 #include "compression.h"
 #include "qgroup.h"
 #include "inode-map.h"
+#include "block-group.h"
+#include "space-info.h"
 
 /* magic values for the inode_only field in btrfs_log_inode:
  *
@@ -2664,6 +2666,29 @@ static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
        return ret;
 }
 
+/*
+ * Correctly adjust the reserved bytes occupied by a log tree extent buffer
+ */
+static void unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start)
+{
+       struct btrfs_block_group *cache;
+
+       cache = btrfs_lookup_block_group(fs_info, start);
+       if (!cache) {
+               btrfs_err(fs_info, "unable to find block group for %llu", start);
+               return;
+       }
+
+       spin_lock(&cache->space_info->lock);
+       spin_lock(&cache->lock);
+       cache->reserved -= fs_info->nodesize;
+       cache->space_info->bytes_reserved -= fs_info->nodesize;
+       spin_unlock(&cache->lock);
+       spin_unlock(&cache->space_info->lock);
+
+       btrfs_put_block_group(cache);
+}
+
 static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
                                   struct btrfs_root *root,
                                   struct btrfs_path *path, int *level,