[PATCH 07/16] btrfs: move btrfs_init_workqueus() and btrfs_stop_all_workers() into open_ctree_seq[]

[Qu Wenruo <wqu@suse.com>]

Those two helpers are already doing all the work, just move them into
the open_ctree_seq[] array.

There is only one small change:

- Call btrfs_stop_all_workers() inside btrfs_init_workqueus() for error
  handling
  Since open_ctree_seq[] makes all error path to call the exit function
  if and only if the corresponding init function finished without error.

  This means, if btrfs_init_workqueus() failed due to -ENOMEM, then we
  won't call btrfs_stop_all_workers() to cleanup whatever is already
  allocatd.

  To fix this problem, call btrfs_stop_all_workers() inside
  btrfs_init_workqueus() when we hit errors.
  Function btrfs_stop_all_workers() already has the checks to
  handle NULL pointers.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/disk-io.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ec9038eeaa0f..0e1fe12c1c99 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2318,11 +2318,12 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info)
 	      fs_info->endio_freespace_worker && fs_info->rmw_workers &&
 	      fs_info->caching_workers && fs_info->fixup_workers &&
 	      fs_info->delayed_workers && fs_info->qgroup_rescan_workers &&
-	      fs_info->discard_ctl.discard_workers)) {
-		return -ENOMEM;
-	}
-
+	      fs_info->discard_ctl.discard_workers))
+		goto error;
 	return 0;
+error:
+	btrfs_stop_all_workers(fs_info);
+	return -ENOMEM;
 }
 
 static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
@@ -3577,6 +3578,9 @@ static const struct init_sequence open_ctree_seq[] = {
 	}, {
 		.init_func = open_ctree_features_init,
 		.exit_func = NULL,
+	}, {
+		.init_func = btrfs_init_workqueues,
+		.exit_func = btrfs_stop_all_workers,
 	}
 };
 
@@ -3604,12 +3608,6 @@ int __cold open_ctree(struct super_block *sb, char *options)
 		open_ctree_res[i] = true;
 	}
 
-	ret = btrfs_init_workqueues(fs_info);
-	if (ret) {
-		err = ret;
-		goto fail_sb_buffer;
-	}
-
 	mutex_lock(&fs_info->chunk_mutex);
 	ret = btrfs_read_sys_array(fs_info);
 	mutex_unlock(&fs_info->chunk_mutex);
@@ -3854,7 +3852,6 @@ int __cold open_ctree(struct super_block *sb, char *options)
 	free_root_pointers(fs_info, true);
 
 fail_sb_buffer:
-	btrfs_stop_all_workers(fs_info);
 	btrfs_free_block_groups(fs_info);
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
 fail:
-- 
2.37.3