btrfs: qgroup: Switch rescan to new mechanism.

Switch rescan to use the new new extent oriented mechanism.

As rescan is also based on extent, new mechanism is just a perfect match
for rescan.

With re-designed internal functions, rescan is quite easy, just call
btrfs_find_all_roots() and then btrfs_qgroup_account_one_extent().

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 607c6ca349559acab9df20952fc3202a70a26aac..70c366f27e25ca52fff2d1e7d09ae2aacb2c39a2 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -3002,15 +3002,13 @@ void assert_qgroups_uptodate(struct btrfs_trans_handle *trans)
  */
 static int
 qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
-                  struct btrfs_trans_handle *trans, struct ulist *qgroups,
-                  struct ulist *tmp, struct extent_buffer *scratch_leaf)
+                  struct btrfs_trans_handle *trans,
+                  struct extent_buffer *scratch_leaf)
 {
        struct btrfs_key found;
        struct ulist *roots = NULL;
        struct seq_list tree_mod_seq_elem = SEQ_LIST_INIT(tree_mod_seq_elem);
        u64 num_bytes;
-       u64 seq;
-       int new_roots;
        int slot;
        int ret;
 
@@ -3060,33 +3058,15 @@ qgroup_rescan_leaf(struct btrfs_fs_info *fs_info, struct btrfs_path *path,
                else
                        num_bytes = found.offset;
 
-               ulist_reinit(qgroups);
                ret = btrfs_find_all_roots(NULL, fs_info, found.objectid, 0,
                                           &roots);
                if (ret < 0)
                        goto out;
-               spin_lock(&fs_info->qgroup_lock);
-               seq = fs_info->qgroup_seq;
-               fs_info->qgroup_seq += roots->nnodes + 1; /* max refcnt */
-
-               new_roots = 0;
-               ret = qgroup_calc_old_refcnt(fs_info, 0, tmp, roots, qgroups,
-                                            seq, &new_roots, 1);
-               if (ret < 0) {
-                       spin_unlock(&fs_info->qgroup_lock);
-                       ulist_free(roots);
-                       goto out;
-               }
-
-               ret = qgroup_adjust_counters(fs_info, 0, num_bytes, qgroups,
-                                            seq, 0, new_roots, 1);
-               if (ret < 0) {
-                       spin_unlock(&fs_info->qgroup_lock);
-                       ulist_free(roots);
+               /* For rescan, just pass old_roots as NULL */
+               ret = btrfs_qgroup_account_extent(trans, fs_info,
+                               found.objectid, num_bytes, NULL, roots);
+               if (ret < 0)
                        goto out;
-               }
-               spin_unlock(&fs_info->qgroup_lock);
-               ulist_free(roots);
        }
 out:
        btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
@@ -3100,7 +3080,6 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
                                                     qgroup_rescan_work);
        struct btrfs_path *path;
        struct btrfs_trans_handle *trans = NULL;
-       struct ulist *tmp = NULL, *qgroups = NULL;
        struct extent_buffer *scratch_leaf = NULL;
        int err = -ENOMEM;
        int ret = 0;
@@ -3108,12 +3087,6 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
        path = btrfs_alloc_path();
        if (!path)
                goto out;
-       qgroups = ulist_alloc(GFP_NOFS);
-       if (!qgroups)
-               goto out;
-       tmp = ulist_alloc(GFP_NOFS);
-       if (!tmp)
-               goto out;
        scratch_leaf = kmalloc(sizeof(*scratch_leaf), GFP_NOFS);
        if (!scratch_leaf)
                goto out;
@@ -3129,7 +3102,7 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
                        err = -EINTR;
                } else {
                        err = qgroup_rescan_leaf(fs_info, path, trans,
-                                                qgroups, tmp, scratch_leaf);
+                                                scratch_leaf);
                }
                if (err > 0)
                        btrfs_commit_transaction(trans, fs_info->fs_root);
@@ -3139,8 +3112,6 @@ static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
 
 out:
        kfree(scratch_leaf);
-       ulist_free(qgroups);
-       ulist_free(tmp);
        btrfs_free_path(path);
 
        mutex_lock(&fs_info->qgroup_rescan_lock);