btrfs: qgroup: Refactor btrfs_qgroup_trace_subtree_swap

Refactor btrfs_qgroup_trace_subtree_swap() into
qgroup_trace_subtree_swap(), which only needs two extent buffer and some
other bool to control the behavior.

This provides the basis for later delayed subtree scan work.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 4e473a9982191b0bc0f2fd9036cfdb88fe51194b..7a69489896555b5f478d870d2a6b4021590e7625 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -2017,6 +2017,59 @@ out:
        return ret;
 }
 
+static int qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
+                               struct extent_buffer *src_eb,
+                               struct extent_buffer *dst_eb,
+                               u64 last_snapshot, bool trace_leaf)
+{
+       struct btrfs_fs_info *fs_info = trans->fs_info;
+       struct btrfs_path *dst_path = NULL;
+       int level;
+       int ret;
+
+       if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
+               return 0;
+
+       /* Wrong parameter order */
+       if (btrfs_header_generation(src_eb) > btrfs_header_generation(dst_eb)) {
+               btrfs_err_rl(fs_info,
+               "%s: bad parameter order, src_gen=%llu dst_gen=%llu", __func__,
+                            btrfs_header_generation(src_eb),
+                            btrfs_header_generation(dst_eb));
+               return -EUCLEAN;
+       }
+
+       if (!extent_buffer_uptodate(src_eb) || !extent_buffer_uptodate(dst_eb)) {
+               ret = -EIO;
+               goto out;
+       }
+
+       level = btrfs_header_level(dst_eb);
+       dst_path = btrfs_alloc_path();
+       if (!dst_path) {
+               ret = -ENOMEM;
+               goto out;
+       }
+       /* For dst_path */
+       extent_buffer_get(dst_eb);
+       dst_path->nodes[level] = dst_eb;
+       dst_path->slots[level] = 0;
+       dst_path->locks[level] = 0;
+
+       /* Do the generation aware breadth-first search */
+       ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
+                                             level, last_snapshot, trace_leaf);
+       if (ret < 0)
+               goto out;
+       ret = 0;
+
+out:
+       btrfs_free_path(dst_path);
+       if (ret < 0)
+               fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
+       return ret;
+}
+
 /*
  * Inform qgroup to trace subtree swap used in balance.
  *
@@ -2042,14 +2095,12 @@ int btrfs_qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
                                u64 last_snapshot)
 {
        struct btrfs_fs_info *fs_info = trans->fs_info;
-       struct btrfs_path *dst_path = NULL;
        struct btrfs_key first_key;
        struct extent_buffer *src_eb = NULL;
        struct extent_buffer *dst_eb = NULL;
        bool trace_leaf = false;
        u64 child_gen;
        u64 child_bytenr;
-       int level;
        int ret;
 
        if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
@@ -2100,22 +2151,9 @@ int btrfs_qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
                goto out;
        }
 
-       level = btrfs_header_level(dst_eb);
-       dst_path = btrfs_alloc_path();
-       if (!dst_path) {
-               ret = -ENOMEM;
-               goto out;
-       }
-
-       /* For dst_path */
-       extent_buffer_get(dst_eb);
-       dst_path->nodes[level] = dst_eb;
-       dst_path->slots[level] = 0;
-       dst_path->locks[level] = 0;
-
-       /* Do the generation-aware breadth-first search */
-       ret = qgroup_trace_new_subtree_blocks(trans, src_eb, dst_path, level,
-                                             level, last_snapshot, trace_leaf);
+       /* Do the generation aware breadth-first search */
+       ret = qgroup_trace_subtree_swap(trans, src_eb, dst_eb, last_snapshot,
+                                       trace_leaf);
        if (ret < 0)
                goto out;
        ret = 0;
@@ -2123,9 +2161,6 @@ int btrfs_qgroup_trace_subtree_swap(struct btrfs_trans_handle *trans,
 out:
        free_extent_buffer(src_eb);
        free_extent_buffer(dst_eb);
-       btrfs_free_path(dst_path);
-       if (ret < 0)
-               fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
        return ret;
 }