btrfs: Replace fs_info->fixup_workers workqueue with btrfs_workqueue.

Replace the fs_info->fixup_workers with the newly created
btrfs_workqueue.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Tested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fb.com>

fs/btrfs/ctree.h

@@ -1524,7 +1524,7 @@ struct btrfs_fs_info {
 	 * the cow mechanism and make them safe to write.  It happens
 	 * for the sys_munmap function call path
 	 */
-	struct btrfs_workers fixup_workers;
+	struct btrfs_workqueue_struct *fixup_workers;
 	struct btrfs_workers delayed_workers;
 	struct task_struct *transaction_kthread;
 	struct task_struct *cleaner_kthread;

fs/btrfs/disk-io.c

@@ -1995,7 +1995,7 @@ static noinline int next_root_backup(struct btrfs_fs_info *info,
 static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
 {
 	btrfs_stop_workers(&fs_info->generic_worker);
-	btrfs_stop_workers(&fs_info->fixup_workers);
+	btrfs_destroy_workqueue(fs_info->fixup_workers);
 	btrfs_destroy_workqueue(fs_info->delalloc_workers);
 	btrfs_destroy_workqueue(fs_info->workers);
 	btrfs_destroy_workqueue(fs_info->endio_workers);
@@ -2498,8 +2498,8 @@ int open_ctree(struct super_block *sb,
 				      min_t(u64, fs_devices->num_devices,
 					    max_active), 64);
 
-	btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
-			   &fs_info->generic_worker);
+	fs_info->fixup_workers =
+		btrfs_alloc_workqueue("fixup", flags, 1, 0);
 
 	/*
 	 * endios are largely parallel and should have a very
@@ -2532,7 +2532,6 @@ int open_ctree(struct super_block *sb,
 	 * return -ENOMEM if any of these fail.
 	 */
 	ret = btrfs_start_workers(&fs_info->generic_worker);
-	ret |= btrfs_start_workers(&fs_info->fixup_workers);
 	ret |= btrfs_start_workers(&fs_info->delayed_workers);
 	ret |= btrfs_start_workers(&fs_info->qgroup_rescan_workers);
 	if (ret) {
@@ -2545,7 +2544,8 @@ int open_ctree(struct super_block *sb,
 	      fs_info->endio_meta_write_workers &&
 	      fs_info->endio_write_workers && fs_info->endio_raid56_workers &&
 	      fs_info->endio_freespace_worker && fs_info->rmw_workers &&
-	      fs_info->caching_workers && fs_info->readahead_workers)) {
+	      fs_info->caching_workers && fs_info->readahead_workers &&
+	      fs_info->fixup_workers)) {
 		err = -ENOMEM;
 		goto fail_sb_buffer;
 	}

fs/btrfs/inode.c

@@ -1748,10 +1748,10 @@ int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
 /* see btrfs_writepage_start_hook for details on why this is required */
 struct btrfs_writepage_fixup {
 	struct page *page;
-	struct btrfs_work work;
+	struct btrfs_work_struct work;
 };
 
-static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
+static void btrfs_writepage_fixup_worker(struct btrfs_work_struct *work)
 {
 	struct btrfs_writepage_fixup *fixup;
 	struct btrfs_ordered_extent *ordered;
@@ -1842,9 +1842,9 @@ static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
 
 	SetPageChecked(page);
 	page_cache_get(page);
-	fixup->work.func = btrfs_writepage_fixup_worker;
+	btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
 	fixup->page = page;
-	btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
+	btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
 	return -EBUSY;
 }
 

fs/btrfs/super.c

@@ -1328,7 +1328,6 @@ static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
 	btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
 	btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
 	btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
-	btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
 	btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
 	btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
 	btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,