btrfs: Move qgroup rescan on quota enable to btrfs_quota_enable

Currently btrfs_run_qgroups is doing a bit too much. Not only is it
responsible for synchronizing in-memory state of qgroups to disk but
it also contains code to trigger the initial qgroup rescan when
quota is enabled initially. This condition is detected by checking that
BTRFS_FS_QUOTA_ENABLED is not set and BTRFS_FS_QUOTA_ENABLING is set.
Nothing really requires from the code to be structured (and scattered)
the way it is so let's streamline things. First move the quota rescan
code into btrfs_quota_enable, where its invocation is closer to the
use. This also makes the FS_QUOTA_ENABLING flag redundant so let's
remove it as well.

This has been tested with a full xfstest run with qgroups enabled on
the scratch device of every xfstest and no regressions were observed.

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

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 024d5fe..fa29ad8 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -707,7 +707,6 @@ struct btrfs_delayed_root;
 #define BTRFS_FS_LOG_RECOVERING                        4
 #define BTRFS_FS_OPEN                          5
 #define BTRFS_FS_QUOTA_ENABLED                 6
-#define BTRFS_FS_QUOTA_ENABLING                        7
 #define BTRFS_FS_UPDATE_UUID_TREE_GEN          9
 #define BTRFS_FS_CREATING_FREE_SPACE_TREE      10
 #define BTRFS_FS_BTREE_ERR                     11

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index aa259d6..0fa4f07 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -826,10 +826,8 @@ int btrfs_quota_enable(struct btrfs_trans_handle *trans,
        int slot;
 
        mutex_lock(&fs_info->qgroup_ioctl_lock);
-       if (fs_info->quota_root) {
-               set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
+       if (fs_info->quota_root)
                goto out;
-       }
 
        fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
        if (!fs_info->qgroup_ulist) {
@@ -923,8 +921,15 @@ out_add_root:
        }
        spin_lock(&fs_info->qgroup_lock);
        fs_info->quota_root = quota_root;
-       set_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags);
+       set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
        spin_unlock(&fs_info->qgroup_lock);
+       ret = qgroup_rescan_init(fs_info, 0, 1);
+       if (!ret) {
+               qgroup_rescan_zero_tracking(fs_info);
+               btrfs_queue_work(fs_info->qgroup_rescan_workers,
+                                &fs_info->qgroup_rescan_work);
+       }
+
 out_free_path:
        btrfs_free_path(path);
 out_free_root:
@@ -2080,17 +2085,9 @@ int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
 {
        struct btrfs_root *quota_root = fs_info->quota_root;
        int ret = 0;
-       int start_rescan_worker = 0;
 
        if (!quota_root)
-               goto out;
-
-       if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags) &&
-           test_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
-               start_rescan_worker = 1;
-
-       if (test_and_clear_bit(BTRFS_FS_QUOTA_ENABLING, &fs_info->flags))
-               set_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
+               return ret;
 
        spin_lock(&fs_info->qgroup_lock);
        while (!list_empty(&fs_info->dirty_qgroups)) {
@@ -2119,18 +2116,6 @@ int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
        if (ret)
                fs_info->qgroup_flags |= BTRFS_QGROUP_STATUS_FLAG_INCONSISTENT;
 
-       if (!ret && start_rescan_worker) {
-               ret = qgroup_rescan_init(fs_info, 0, 1);
-               if (!ret) {
-                       qgroup_rescan_zero_tracking(fs_info);
-                       btrfs_queue_work(fs_info->qgroup_rescan_workers,
-                                        &fs_info->qgroup_rescan_work);
-               }
-               ret = 0;
-       }
-
-out:
-
        return ret;
 }