Re: [PATCH 2/9] btrfs: use kernel workqueue to replace the btrfs_workers functions

[Stefan Behrens <sbehrens@giantdisaster.de>]

On Wed, 11 Sep 2013 16:52:31 +0800, Qu Wenruo wrote:
> Use the kernel workqueue to replace the btrfs_workers which are only
> used as normal workqueue.
> 
> Other btrfs_workers will use some extra functions like requeue, high
> priority and ordered work.
> These btrfs_workers will not be touched in this patch.
> 
> The followings are the untouched btrfs_workers:
> 
> generic_worker:		As the helper for other btrfs_workers
> workers:		Use the ordering and high priority features
> delalloc_workers: 	Use the ordering feature
> submit_workers:		Use requeue feature
> 
> All other workers can be replaced using the kernel workqueue directly.
> 
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> ---
>  fs/btrfs/ctree.h         |  39 +++++------
>  fs/btrfs/delayed-inode.c |   9 ++-
>  fs/btrfs/disk-io.c       | 164 ++++++++++++++++++-----------------------------
>  fs/btrfs/extent-tree.c   |   6 +-
>  fs/btrfs/inode.c         |  38 +++++------
>  fs/btrfs/ordered-data.c  |  11 ++--
>  fs/btrfs/ordered-data.h  |   4 +-
>  fs/btrfs/qgroup.c        |  16 ++---
>  fs/btrfs/raid56.c        |  37 +++++------
>  fs/btrfs/reada.c         |   8 +--
>  fs/btrfs/scrub.c         |  78 ++++++++++------------
>  fs/btrfs/super.c         |  23 ++++---
>  12 files changed, 190 insertions(+), 243 deletions(-)
> 
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index e795bf1..0dd6ec9 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -1202,7 +1202,7 @@ struct btrfs_caching_control {
>  	struct list_head list;
>  	struct mutex mutex;
>  	wait_queue_head_t wait;
> -	struct btrfs_work work;
> +	struct work_struct work;
>  	struct btrfs_block_group_cache *block_group;
>  	u64 progress;
>  	atomic_t count;
> @@ -1479,25 +1479,26 @@ struct btrfs_fs_info {
>  	struct btrfs_workers generic_worker;
>  	struct btrfs_workers workers;
>  	struct btrfs_workers delalloc_workers;
> -	struct btrfs_workers flush_workers;
> -	struct btrfs_workers endio_workers;
> -	struct btrfs_workers endio_meta_workers;
> -	struct btrfs_workers endio_raid56_workers;
> -	struct btrfs_workers rmw_workers;
> -	struct btrfs_workers endio_meta_write_workers;
> -	struct btrfs_workers endio_write_workers;
> -	struct btrfs_workers endio_freespace_worker;
>  	struct btrfs_workers submit_workers;
> -	struct btrfs_workers caching_workers;
> -	struct btrfs_workers readahead_workers;
> +
> +	struct workqueue_struct *flush_workers;
> +	struct workqueue_struct *endio_workers;
> +	struct workqueue_struct *endio_meta_workers;
> +	struct workqueue_struct *endio_raid56_workers;
> +	struct workqueue_struct *rmw_workers;
> +	struct workqueue_struct *endio_meta_write_workers;
> +	struct workqueue_struct *endio_write_workers;
> +	struct workqueue_struct *endio_freespace_worker;
> +	struct workqueue_struct *caching_workers;
> +	struct workqueue_struct *readahead_workers;
>  
>  	/*
>  	 * fixup workers take dirty pages that didn't properly go through
>  	 * 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_workers delayed_workers;
> +	struct workqueue_struct *fixup_workers;
> +	struct workqueue_struct *delayed_workers;
>  	struct task_struct *transaction_kthread;
>  	struct task_struct *cleaner_kthread;
>  	int thread_pool_size;
> @@ -1576,9 +1577,9 @@ struct btrfs_fs_info {
>  	wait_queue_head_t scrub_pause_wait;
>  	struct rw_semaphore scrub_super_lock;
>  	int scrub_workers_refcnt;
> -	struct btrfs_workers scrub_workers;
> -	struct btrfs_workers scrub_wr_completion_workers;
> -	struct btrfs_workers scrub_nocow_workers;
> +	struct workqueue_struct *scrub_workers;
> +	struct workqueue_struct *scrub_wr_completion_workers;
> +	struct workqueue_struct *scrub_nocow_workers;
>  
>  #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
>  	u32 check_integrity_print_mask;
> @@ -1619,9 +1620,9 @@ struct btrfs_fs_info {
>  	/* qgroup rescan items */
>  	struct mutex qgroup_rescan_lock; /* protects the progress item */
>  	struct btrfs_key qgroup_rescan_progress;
> -	struct btrfs_workers qgroup_rescan_workers;
> +	struct workqueue_struct *qgroup_rescan_workers;
>  	struct completion qgroup_rescan_completion;
> -	struct btrfs_work qgroup_rescan_work;
> +	struct work_struct qgroup_rescan_work;
>  
>  	/* filesystem state */
>  	unsigned long fs_state;
> @@ -3542,7 +3543,7 @@ struct btrfs_delalloc_work {
>  	int delay_iput;
>  	struct completion completion;
>  	struct list_head list;
> -	struct btrfs_work work;
> +	struct work_struct work;
>  };
>  
>  struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
> diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
> index 5615eac..2b8da0a7 100644
> --- a/fs/btrfs/delayed-inode.c
> +++ b/fs/btrfs/delayed-inode.c
> @@ -1258,10 +1258,10 @@ void btrfs_remove_delayed_node(struct inode *inode)
>  struct btrfs_async_delayed_work {
>  	struct btrfs_delayed_root *delayed_root;
>  	int nr;
> -	struct btrfs_work work;
> +	struct work_struct work;
>  };
>  
> -static void btrfs_async_run_delayed_root(struct btrfs_work *work)
> +static void btrfs_async_run_delayed_root(struct work_struct *work)
>  {
>  	struct btrfs_async_delayed_work *async_work;
>  	struct btrfs_delayed_root *delayed_root;
> @@ -1359,11 +1359,10 @@ static int btrfs_wq_run_delayed_node(struct btrfs_delayed_root *delayed_root,
>  		return -ENOMEM;
>  
>  	async_work->delayed_root = delayed_root;
> -	async_work->work.func = btrfs_async_run_delayed_root;
> -	async_work->work.flags = 0;
> +	INIT_WORK(&async_work->work, btrfs_async_run_delayed_root);
>  	async_work->nr = nr;
>  
> -	btrfs_queue_worker(&root->fs_info->delayed_workers, &async_work->work);
> +	queue_work(root->fs_info->delayed_workers, &async_work->work);
>  	return 0;
>  }
>  
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 3c2886c..0f44828 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -54,7 +54,7 @@
>  #endif
>  
>  static struct extent_io_ops btree_extent_io_ops;
> -static void end_workqueue_fn(struct btrfs_work *work);
> +static void end_workqueue_fn(struct work_struct *work);
>  static void free_fs_root(struct btrfs_root *root);
>  static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
>  				    int read_only);
> @@ -86,7 +86,7 @@ struct end_io_wq {
>  	int error;
>  	int metadata;
>  	struct list_head list;
> -	struct btrfs_work work;
> +	struct work_struct work;
>  };
>  
>  /*
> @@ -692,31 +692,30 @@ static void end_workqueue_bio(struct bio *bio, int err)
>  
>  	fs_info = end_io_wq->info;
>  	end_io_wq->error = err;
> -	end_io_wq->work.func = end_workqueue_fn;
> -	end_io_wq->work.flags = 0;
> +	INIT_WORK(&end_io_wq->work, end_workqueue_fn);
>  
>  	if (bio->bi_rw & REQ_WRITE) {
>  		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA)
> -			btrfs_queue_worker(&fs_info->endio_meta_write_workers,
> -					   &end_io_wq->work);
> +			queue_work(fs_info->endio_meta_write_workers,
> +				   &end_io_wq->work);
>  		else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_FREE_SPACE)
> -			btrfs_queue_worker(&fs_info->endio_freespace_worker,
> -					   &end_io_wq->work);
> +			queue_work(fs_info->endio_freespace_worker,
> +				   &end_io_wq->work);
>  		else if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
> -			btrfs_queue_worker(&fs_info->endio_raid56_workers,
> -					   &end_io_wq->work);
> +			queue_work(fs_info->endio_raid56_workers,
> +				   &end_io_wq->work);
>  		else
> -			btrfs_queue_worker(&fs_info->endio_write_workers,
> -					   &end_io_wq->work);
> +			queue_work(fs_info->endio_write_workers,
> +				   &end_io_wq->work);
>  	} else {
>  		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_RAID56)
> -			btrfs_queue_worker(&fs_info->endio_raid56_workers,
> +			queue_work(fs_info->endio_raid56_workers,
>  					   &end_io_wq->work);
>  		else if (end_io_wq->metadata)
> -			btrfs_queue_worker(&fs_info->endio_meta_workers,
> +			queue_work(fs_info->endio_meta_workers,
>  					   &end_io_wq->work);
>  		else
> -			btrfs_queue_worker(&fs_info->endio_workers,
> +			queue_work(fs_info->endio_workers,
>  					   &end_io_wq->work);
>  	}
>  }
> @@ -1662,7 +1661,7 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
>   * called by the kthread helper functions to finally call the bio end_io
>   * functions.  This is where read checksum verification actually happens
>   */
> -static void end_workqueue_fn(struct btrfs_work *work)
> +static void end_workqueue_fn(struct work_struct *work)
>  {
>  	struct bio *bio;
>  	struct end_io_wq *end_io_wq;
> @@ -1987,22 +1986,22 @@ 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_stop_workers(&fs_info->delalloc_workers);
>  	btrfs_stop_workers(&fs_info->workers);
> -	btrfs_stop_workers(&fs_info->endio_workers);
> -	btrfs_stop_workers(&fs_info->endio_meta_workers);
> -	btrfs_stop_workers(&fs_info->endio_raid56_workers);
> -	btrfs_stop_workers(&fs_info->rmw_workers);
> -	btrfs_stop_workers(&fs_info->endio_meta_write_workers);
> -	btrfs_stop_workers(&fs_info->endio_write_workers);
> -	btrfs_stop_workers(&fs_info->endio_freespace_worker);
>  	btrfs_stop_workers(&fs_info->submit_workers);
> -	btrfs_stop_workers(&fs_info->delayed_workers);
> -	btrfs_stop_workers(&fs_info->caching_workers);
> -	btrfs_stop_workers(&fs_info->readahead_workers);
> -	btrfs_stop_workers(&fs_info->flush_workers);
> -	btrfs_stop_workers(&fs_info->qgroup_rescan_workers);
> +	destroy_workqueue(fs_info->fixup_workers);
> +	destroy_workqueue(fs_info->endio_workers);
> +	destroy_workqueue(fs_info->endio_meta_workers);
> +	destroy_workqueue(fs_info->endio_raid56_workers);
> +	destroy_workqueue(fs_info->rmw_workers);
> +	destroy_workqueue(fs_info->endio_meta_write_workers);
> +	destroy_workqueue(fs_info->endio_write_workers);
> +	destroy_workqueue(fs_info->endio_freespace_worker);
> +	destroy_workqueue(fs_info->delayed_workers);
> +	destroy_workqueue(fs_info->caching_workers);
> +	destroy_workqueue(fs_info->readahead_workers);
> +	destroy_workqueue(fs_info->flush_workers);
> +	destroy_workqueue(fs_info->qgroup_rescan_workers);
>  }
>  
>  /* helper to cleanup tree roots */
> @@ -2099,6 +2098,8 @@ int open_ctree(struct super_block *sb,
>  	struct btrfs_root *quota_root;
>  	struct btrfs_root *log_tree_root;
>  	int ret;
> +	int max_active;
> +	int flags = WQ_UNBOUND | WQ_MEM_RECLAIM;
>  	int err = -EINVAL;
>  	int num_backups_tried = 0;
>  	int backup_index = 0;
> @@ -2457,6 +2458,7 @@ int open_ctree(struct super_block *sb,
>  		goto fail_alloc;
>  	}
>  
> +	max_active = fs_info->thread_pool_size;
>  	btrfs_init_workers(&fs_info->generic_worker,
>  			   "genwork", 1, NULL);
>  
> @@ -2468,23 +2470,13 @@ int open_ctree(struct super_block *sb,
>  			   fs_info->thread_pool_size,
>  			   &fs_info->generic_worker);
>  
> -	btrfs_init_workers(&fs_info->flush_workers, "flush_delalloc",
> -			   fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -
> +	fs_info->flush_workers = alloc_workqueue("flush_delalloc", flags,
> +						 max_active);
>  	btrfs_init_workers(&fs_info->submit_workers, "submit",
>  			   min_t(u64, fs_devices->num_devices,
>  			   fs_info->thread_pool_size),
>  			   &fs_info->generic_worker);
> -
> -	btrfs_init_workers(&fs_info->caching_workers, "cache",
> -			   2, &fs_info->generic_worker);
> -
> -	/* a higher idle thresh on the submit workers makes it much more
> -	 * likely that bios will be send down in a sane order to the
> -	 * devices
> -	 */
> -	fs_info->submit_workers.idle_thresh = 64;
> +	fs_info->caching_workers = alloc_workqueue("cache", flags, 2);
>  
>  	fs_info->workers.idle_thresh = 16;
>  	fs_info->workers.ordered = 1;
> @@ -2492,72 +2484,42 @@ int open_ctree(struct super_block *sb,
>  	fs_info->delalloc_workers.idle_thresh = 2;
>  	fs_info->delalloc_workers.ordered = 1;
>  
> -	btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->endio_workers, "endio",
> -			   fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
> -			   fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->endio_meta_write_workers,
> -			   "endio-meta-write", fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->endio_raid56_workers,
> -			   "endio-raid56", fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->rmw_workers,
> -			   "rmw", fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
> -			   fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
> -			   1, &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
> -			   fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->readahead_workers, "readahead",
> -			   fs_info->thread_pool_size,
> -			   &fs_info->generic_worker);
> -	btrfs_init_workers(&fs_info->qgroup_rescan_workers, "qgroup-rescan", 1,
> -			   &fs_info->generic_worker);
> -
> -	/*
> -	 * endios are largely parallel and should have a very
> -	 * low idle thresh
> -	 */
> -	fs_info->endio_workers.idle_thresh = 4;
> -	fs_info->endio_meta_workers.idle_thresh = 4;
> -	fs_info->endio_raid56_workers.idle_thresh = 4;
> -	fs_info->rmw_workers.idle_thresh = 2;
> -
> -	fs_info->endio_write_workers.idle_thresh = 2;
> -	fs_info->endio_meta_write_workers.idle_thresh = 2;
> -	fs_info->readahead_workers.idle_thresh = 2;
> -
> +	fs_info->fixup_workers = alloc_workqueue("fixup", flags, 1);
> +	fs_info->endio_workers = alloc_workqueue("endio", flags, max_active);
> +	fs_info->endio_meta_workers = alloc_workqueue("endio-meta", flags,
> +						      max_active);
> +	fs_info->endio_meta_write_workers = alloc_workqueue("endio-meta-write",
> +							    flags, max_active);
> +	fs_info->endio_raid56_workers = alloc_workqueue("endio-raid56", flags,
> +							max_active);
> +	fs_info->rmw_workers = alloc_workqueue("rmw", flags, max_active);
> +	fs_info->endio_write_workers = alloc_workqueue("endio-write", flags,
> +						       max_active);
> +	fs_info->endio_freespace_worker = alloc_workqueue("freespace-write",
> +							  flags, 1);
> +	fs_info->delayed_workers = alloc_workqueue("delayed_meta", flags,
> +						   max_active);
> +	fs_info->readahead_workers = alloc_workqueue("readahead", flags,
> +						     max_active);
> +	fs_info->qgroup_rescan_workers = alloc_workqueue("group-rescan",
> +							 flags, 1);
>  	/*
>  	 * btrfs_start_workers can really only fail because of ENOMEM so just
>  	 * return -ENOMEM if any of these fail.
>  	 */
>  	ret = btrfs_start_workers(&fs_info->workers);
>  	ret |= btrfs_start_workers(&fs_info->generic_worker);
> -	ret |= btrfs_start_workers(&fs_info->submit_workers);
>  	ret |= btrfs_start_workers(&fs_info->delalloc_workers);
> -	ret |= btrfs_start_workers(&fs_info->fixup_workers);
> -	ret |= btrfs_start_workers(&fs_info->endio_workers);
> -	ret |= btrfs_start_workers(&fs_info->endio_meta_workers);
> -	ret |= btrfs_start_workers(&fs_info->rmw_workers);
> -	ret |= btrfs_start_workers(&fs_info->endio_raid56_workers);
> -	ret |= btrfs_start_workers(&fs_info->endio_meta_write_workers);
> -	ret |= btrfs_start_workers(&fs_info->endio_write_workers);
> -	ret |= btrfs_start_workers(&fs_info->endio_freespace_worker);
> -	ret |= btrfs_start_workers(&fs_info->delayed_workers);
> -	ret |= btrfs_start_workers(&fs_info->caching_workers);
> -	ret |= btrfs_start_workers(&fs_info->readahead_workers);
> -	ret |= btrfs_start_workers(&fs_info->flush_workers);
> -	ret |= btrfs_start_workers(&fs_info->qgroup_rescan_workers);
> -	if (ret) {
> +	ret |= btrfs_start_workers(&fs_info->submit_workers);
> +
> +	if (ret || !(fs_info->flush_workers && fs_info->endio_workers &&
> +		     fs_info->endio_meta_workers &&
> +		     fs_info->endio_raid56_workers &&
> +		     fs_info->rmw_workers &&
> +		     fs_info->endio_meta_write_workers &&
> +		     fs_info->endio_write_workers &&
> +		     fs_info->caching_workers && fs_info->readahead_workers &&
> +		     fs_info->fixup_workers && fs_info->delayed_workers)) {

fs_info->qgroup_rescan_workers is missing?


>  		err = -ENOMEM;
>  		goto fail_sb_buffer;
>  	}
> diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
> index 0236de7..c8f67d9 100644
> --- a/fs/btrfs/extent-tree.c
> +++ b/fs/btrfs/extent-tree.c
> @@ -377,7 +377,7 @@ static u64 add_new_free_space(struct btrfs_block_group_cache *block_group,
>  	return total_added;
>  }
>  
> -static noinline void caching_thread(struct btrfs_work *work)
> +static noinline void caching_thread(struct work_struct *work)
>  {
>  	struct btrfs_block_group_cache *block_group;
>  	struct btrfs_fs_info *fs_info;
> @@ -530,7 +530,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
>  	caching_ctl->block_group = cache;
>  	caching_ctl->progress = cache->key.objectid;
>  	atomic_set(&caching_ctl->count, 1);
> -	caching_ctl->work.func = caching_thread;
> +	INIT_WORK(&caching_ctl->work, caching_thread);
>  
>  	spin_lock(&cache->lock);
>  	/*
> @@ -621,7 +621,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
>  
>  	btrfs_get_block_group(cache);
>  
> -	btrfs_queue_worker(&fs_info->caching_workers, &caching_ctl->work);
> +	queue_work(fs_info->caching_workers, &caching_ctl->work);
>  
>  	return ret;
>  }
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index b7c2487..53901a5 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -1818,10 +1818,10 @@ 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 work_struct work;
>  };
>  
> -static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
> +static void btrfs_writepage_fixup_worker(struct work_struct *work)
>  {
>  	struct btrfs_writepage_fixup *fixup;
>  	struct btrfs_ordered_extent *ordered;
> @@ -1912,9 +1912,9 @@ 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;
> +	INIT_WORK(&fixup->work, btrfs_writepage_fixup_worker);
>  	fixup->page = page;
> -	btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
> +	queue_work(root->fs_info->fixup_workers, &fixup->work);
>  	return -EBUSY;
>  }
>  
> @@ -2780,7 +2780,7 @@ out:
>  	return ret;
>  }
>  
> -static void finish_ordered_fn(struct btrfs_work *work)
> +static void finish_ordered_fn(struct work_struct *work)
>  {
>  	struct btrfs_ordered_extent *ordered_extent;
>  	ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
> @@ -2793,7 +2793,7 @@ static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
>  	struct inode *inode = page->mapping->host;
>  	struct btrfs_root *root = BTRFS_I(inode)->root;
>  	struct btrfs_ordered_extent *ordered_extent = NULL;
> -	struct btrfs_workers *workers;
> +	struct workqueue_struct *workers;
>  
>  	trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
>  
> @@ -2802,14 +2802,13 @@ static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
>  					    end - start + 1, uptodate))
>  		return 0;
>  
> -	ordered_extent->work.func = finish_ordered_fn;
> -	ordered_extent->work.flags = 0;
> +	INIT_WORK(&ordered_extent->work, finish_ordered_fn);
>  
>  	if (btrfs_is_free_space_inode(inode))
> -		workers = &root->fs_info->endio_freespace_worker;
> +		workers = root->fs_info->endio_freespace_worker;
>  	else
> -		workers = &root->fs_info->endio_write_workers;
> -	btrfs_queue_worker(workers, &ordered_extent->work);
> +		workers = root->fs_info->endio_write_workers;
> +	queue_work(workers, &ordered_extent->work);
>  
>  	return 0;
>  }
> @@ -6906,10 +6905,9 @@ again:
>  	if (!ret)
>  		goto out_test;
>  
> -	ordered->work.func = finish_ordered_fn;
> -	ordered->work.flags = 0;
> -	btrfs_queue_worker(&root->fs_info->endio_write_workers,
> -			   &ordered->work);
> +	INIT_WORK(&ordered->work, finish_ordered_fn);
> +	queue_work(root->fs_info->endio_write_workers, &ordered->work);
> +
>  out_test:
>  	/*
>  	 * our bio might span multiple ordered extents.  If we haven't
> @@ -8187,7 +8185,7 @@ out_notrans:
>  	return ret;
>  }
>  
> -static void btrfs_run_delalloc_work(struct btrfs_work *work)
> +static void btrfs_run_delalloc_work(struct work_struct *work)
>  {
>  	struct btrfs_delalloc_work *delalloc_work;
>  
> @@ -8206,7 +8204,7 @@ static void btrfs_run_delalloc_work(struct btrfs_work *work)
>  }
>  
>  struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
> -						    int wait, int delay_iput)
> +						      int wait, int delay_iput)
>  {
>  	struct btrfs_delalloc_work *work;
>  
> @@ -8219,8 +8217,7 @@ struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
>  	work->inode = inode;
>  	work->wait = wait;
>  	work->delay_iput = delay_iput;
> -	work->work.func = btrfs_run_delalloc_work;
> -
> +	INIT_WORK(&work->work, btrfs_run_delalloc_work);
>  	return work;
>  }
>  
> @@ -8267,8 +8264,7 @@ static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
>  			goto out;
>  		}
>  		list_add_tail(&work->list, &works);
> -		btrfs_queue_worker(&root->fs_info->flush_workers,
> -				   &work->work);
> +		queue_work(root->fs_info->flush_workers, &work->work);
>  
>  		cond_resched();
>  		spin_lock(&root->delalloc_lock);
> diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
> index 8136982..9b5ccac 100644
> --- a/fs/btrfs/ordered-data.c
> +++ b/fs/btrfs/ordered-data.c
> @@ -552,7 +552,7 @@ void btrfs_remove_ordered_extent(struct inode *inode,
>  	wake_up(&entry->wait);
>  }
>  
> -static void btrfs_run_ordered_extent_work(struct btrfs_work *work)
> +static void btrfs_run_ordered_extent_work(struct work_struct *work)
>  {
>  	struct btrfs_ordered_extent *ordered;
>  
> @@ -594,10 +594,9 @@ void btrfs_wait_ordered_extents(struct btrfs_root *root, int delay_iput)
>  		atomic_inc(&ordered->refs);
>  		spin_unlock(&root->ordered_extent_lock);
>  
> -		ordered->flush_work.func = btrfs_run_ordered_extent_work;
> +		INIT_WORK(&ordered->flush_work, btrfs_run_ordered_extent_work);
>  		list_add_tail(&ordered->work_list, &works);
> -		btrfs_queue_worker(&root->fs_info->flush_workers,
> -				   &ordered->flush_work);
> +		queue_work(root->fs_info->flush_workers, &ordered->flush_work);
>  
>  		cond_resched();
>  		spin_lock(&root->ordered_extent_lock);
> @@ -706,8 +705,8 @@ int btrfs_run_ordered_operations(struct btrfs_trans_handle *trans,
>  			goto out;
>  		}
>  		list_add_tail(&work->list, &works);
> -		btrfs_queue_worker(&root->fs_info->flush_workers,
> -				   &work->work);
> +		queue_work(root->fs_info->flush_workers,
> +			   &work->work);
>  
>  		cond_resched();
>  		spin_lock(&root->fs_info->ordered_root_lock);
> diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h
> index 68844d5..f4c81d7 100644
> --- a/fs/btrfs/ordered-data.h
> +++ b/fs/btrfs/ordered-data.h
> @@ -123,10 +123,10 @@ struct btrfs_ordered_extent {
>  	/* a per root list of all the pending ordered extents */
>  	struct list_head root_extent_list;
>  
> -	struct btrfs_work work;
> +	struct work_struct work;
>  
>  	struct completion completion;
> -	struct btrfs_work flush_work;
> +	struct work_struct flush_work;
>  	struct list_head work_list;
>  };
>  
> diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
> index 1280eff..a49fdfe 100644
> --- a/fs/btrfs/qgroup.c
> +++ b/fs/btrfs/qgroup.c
> @@ -1528,8 +1528,8 @@ int btrfs_run_qgroups(struct btrfs_trans_handle *trans,
>  		ret = qgroup_rescan_init(fs_info, 0, 1);
>  		if (!ret) {
>  			qgroup_rescan_zero_tracking(fs_info);
> -			btrfs_queue_worker(&fs_info->qgroup_rescan_workers,
> -					   &fs_info->qgroup_rescan_work);
> +			queue_work(fs_info->qgroup_rescan_workers,
> +				   &fs_info->qgroup_rescan_work);
>  		}
>  		ret = 0;
>  	}
> @@ -1994,7 +1994,7 @@ out:
>  	return ret;
>  }
>  
> -static void btrfs_qgroup_rescan_worker(struct btrfs_work *work)
> +static void btrfs_qgroup_rescan_worker(struct work_struct *work)
>  {
>  	struct btrfs_fs_info *fs_info = container_of(work, struct btrfs_fs_info,
>  						     qgroup_rescan_work);
> @@ -2105,7 +2105,7 @@ qgroup_rescan_init(struct btrfs_fs_info *fs_info, u64 progress_objectid,
>  
>  	memset(&fs_info->qgroup_rescan_work, 0,
>  	       sizeof(fs_info->qgroup_rescan_work));
> -	fs_info->qgroup_rescan_work.func = btrfs_qgroup_rescan_worker;
> +	INIT_WORK(&fs_info->qgroup_rescan_work, btrfs_qgroup_rescan_worker);
>  
>  	if (ret) {
>  err:
> @@ -2168,8 +2168,8 @@ btrfs_qgroup_rescan(struct btrfs_fs_info *fs_info)
>  
>  	qgroup_rescan_zero_tracking(fs_info);
>  
> -	btrfs_queue_worker(&fs_info->qgroup_rescan_workers,
> -			   &fs_info->qgroup_rescan_work);
> +	queue_work(fs_info->qgroup_rescan_workers,
> +		   &fs_info->qgroup_rescan_work);
>  
>  	return 0;
>  }
> @@ -2200,6 +2200,6 @@ void
>  btrfs_qgroup_rescan_resume(struct btrfs_fs_info *fs_info)
>  {
>  	if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN)
> -		btrfs_queue_worker(&fs_info->qgroup_rescan_workers,
> -				   &fs_info->qgroup_rescan_work);
> +		queue_work(fs_info->qgroup_rescan_workers,
> +			   &fs_info->qgroup_rescan_work);
>  }
> diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c
> index 0525e13..4b7769d 100644
> --- a/fs/btrfs/raid56.c
> +++ b/fs/btrfs/raid56.c
> @@ -88,7 +88,7 @@ struct btrfs_raid_bio {
>  	/*
>  	 * for scheduling work in the helper threads
>  	 */
> -	struct btrfs_work work;
> +	struct work_struct work;
>  
>  	/*
>  	 * bio list and bio_list_lock are used
> @@ -167,8 +167,8 @@ struct btrfs_raid_bio {
>  
>  static int __raid56_parity_recover(struct btrfs_raid_bio *rbio);
>  static noinline void finish_rmw(struct btrfs_raid_bio *rbio);
> -static void rmw_work(struct btrfs_work *work);
> -static void read_rebuild_work(struct btrfs_work *work);
> +static void rmw_work(struct work_struct *work);
> +static void read_rebuild_work(struct work_struct *work);
>  static void async_rmw_stripe(struct btrfs_raid_bio *rbio);
>  static void async_read_rebuild(struct btrfs_raid_bio *rbio);
>  static int fail_bio_stripe(struct btrfs_raid_bio *rbio, struct bio *bio);
> @@ -1417,20 +1417,16 @@ cleanup:
>  
>  static void async_rmw_stripe(struct btrfs_raid_bio *rbio)
>  {
> -	rbio->work.flags = 0;
> -	rbio->work.func = rmw_work;
> -
> -	btrfs_queue_worker(&rbio->fs_info->rmw_workers,
> -			   &rbio->work);
> +	INIT_WORK(&rbio->work, rmw_work);
> +	queue_work(rbio->fs_info->rmw_workers,
> +		   &rbio->work);
>  }
>  
>  static void async_read_rebuild(struct btrfs_raid_bio *rbio)
>  {
> -	rbio->work.flags = 0;
> -	rbio->work.func = read_rebuild_work;
> -
> -	btrfs_queue_worker(&rbio->fs_info->rmw_workers,
> -			   &rbio->work);
> +	INIT_WORK(&rbio->work, read_rebuild_work);
> +	queue_work(rbio->fs_info->rmw_workers,
> +		   &rbio->work);
>  }
>  
>  /*
> @@ -1589,7 +1585,7 @@ struct btrfs_plug_cb {
>  	struct blk_plug_cb cb;
>  	struct btrfs_fs_info *info;
>  	struct list_head rbio_list;
> -	struct btrfs_work work;
> +	struct work_struct work;
>  };
>  
>  /*
> @@ -1653,7 +1649,7 @@ static void run_plug(struct btrfs_plug_cb *plug)
>   * if the unplug comes from schedule, we have to push the
>   * work off to a helper thread
>   */
> -static void unplug_work(struct btrfs_work *work)
> +static void unplug_work(struct work_struct *work)
>  {
>  	struct btrfs_plug_cb *plug;
>  	plug = container_of(work, struct btrfs_plug_cb, work);
> @@ -1666,10 +1662,9 @@ static void btrfs_raid_unplug(struct blk_plug_cb *cb, bool from_schedule)
>  	plug = container_of(cb, struct btrfs_plug_cb, cb);
>  
>  	if (from_schedule) {
> -		plug->work.flags = 0;
> -		plug->work.func = unplug_work;
> -		btrfs_queue_worker(&plug->info->rmw_workers,
> -				   &plug->work);
> +		INIT_WORK(&plug->work, unplug_work);
> +		queue_work(plug->info->rmw_workers,
> +			   &plug->work);
>  		return;
>  	}
>  	run_plug(plug);
> @@ -2083,7 +2078,7 @@ int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
>  
>  }
>  
> -static void rmw_work(struct btrfs_work *work)
> +static void rmw_work(struct work_struct *work)
>  {
>  	struct btrfs_raid_bio *rbio;
>  
> @@ -2091,7 +2086,7 @@ static void rmw_work(struct btrfs_work *work)
>  	raid56_rmw_stripe(rbio);
>  }
>  
> -static void read_rebuild_work(struct btrfs_work *work)
> +static void read_rebuild_work(struct work_struct *work)
>  {
>  	struct btrfs_raid_bio *rbio;
>  
> diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
> index 1031b69..9607648 100644
> --- a/fs/btrfs/reada.c
> +++ b/fs/btrfs/reada.c
> @@ -91,7 +91,7 @@ struct reada_zone {
>  };
>  
>  struct reada_machine_work {
> -	struct btrfs_work	work;
> +	struct work_struct	work;
>  	struct btrfs_fs_info	*fs_info;
>  };
>  
> @@ -732,7 +732,7 @@ static int reada_start_machine_dev(struct btrfs_fs_info *fs_info,
>  
>  }
>  
> -static void reada_start_machine_worker(struct btrfs_work *work)
> +static void reada_start_machine_worker(struct work_struct *work)
>  {
>  	struct reada_machine_work *rmw;
>  	struct btrfs_fs_info *fs_info;
> @@ -792,10 +792,10 @@ static void reada_start_machine(struct btrfs_fs_info *fs_info)
>  		/* FIXME we cannot handle this properly right now */
>  		BUG();
>  	}
> -	rmw->work.func = reada_start_machine_worker;
> +	INIT_WORK(&rmw->work, reada_start_machine_worker);
>  	rmw->fs_info = fs_info;
>  
> -	btrfs_queue_worker(&fs_info->readahead_workers, &rmw->work);
> +	queue_work(fs_info->readahead_workers, &rmw->work);
>  }
>  
>  #ifdef DEBUG
> diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
> index 4ba2a69..ddb7fa2 100644
> --- a/fs/btrfs/scrub.c
> +++ b/fs/btrfs/scrub.c
> @@ -96,7 +96,7 @@ struct scrub_bio {
>  #endif
>  	int			page_count;
>  	int			next_free;
> -	struct btrfs_work	work;
> +	struct work_struct	work;
>  };
>  
>  struct scrub_block {
> @@ -154,7 +154,7 @@ struct scrub_fixup_nodatasum {
>  	struct btrfs_device	*dev;
>  	u64			logical;
>  	struct btrfs_root	*root;
> -	struct btrfs_work	work;
> +	struct work_struct	work;
>  	int			mirror_num;
>  };
>  
> @@ -164,7 +164,7 @@ struct scrub_copy_nocow_ctx {
>  	u64			len;
>  	int			mirror_num;
>  	u64			physical_for_dev_replace;
> -	struct btrfs_work	work;
> +	struct work_struct	work;
>  };
>  
>  struct scrub_warning {
> @@ -224,7 +224,7 @@ static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
>  		       u64 gen, int mirror_num, u8 *csum, int force,
>  		       u64 physical_for_dev_replace);
>  static void scrub_bio_end_io(struct bio *bio, int err);
> -static void scrub_bio_end_io_worker(struct btrfs_work *work);
> +static void scrub_bio_end_io_worker(struct work_struct *work);
>  static void scrub_block_complete(struct scrub_block *sblock);
>  static void scrub_remap_extent(struct btrfs_fs_info *fs_info,
>  			       u64 extent_logical, u64 extent_len,
> @@ -241,14 +241,14 @@ static int scrub_add_page_to_wr_bio(struct scrub_ctx *sctx,
>  				    struct scrub_page *spage);
>  static void scrub_wr_submit(struct scrub_ctx *sctx);
>  static void scrub_wr_bio_end_io(struct bio *bio, int err);
> -static void scrub_wr_bio_end_io_worker(struct btrfs_work *work);
> +static void scrub_wr_bio_end_io_worker(struct work_struct *work);
>  static int write_page_nocow(struct scrub_ctx *sctx,
>  			    u64 physical_for_dev_replace, struct page *page);
>  static int copy_nocow_pages_for_inode(u64 inum, u64 offset, u64 root,
>  				      void *ctx);
>  static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
>  			    int mirror_num, u64 physical_for_dev_replace);
> -static void copy_nocow_pages_worker(struct btrfs_work *work);
> +static void copy_nocow_pages_worker(struct work_struct *work);
>  
>  
>  static void scrub_pending_bio_inc(struct scrub_ctx *sctx)
> @@ -386,7 +386,7 @@ struct scrub_ctx *scrub_setup_ctx(struct btrfs_device *dev, int is_dev_replace)
>  		sbio->index = i;
>  		sbio->sctx = sctx;
>  		sbio->page_count = 0;
> -		sbio->work.func = scrub_bio_end_io_worker;
> +		INIT_WORK(&sbio->work, scrub_bio_end_io_worker);
>  
>  		if (i != SCRUB_BIOS_PER_SCTX - 1)
>  			sctx->bios[i]->next_free = i + 1;
> @@ -691,7 +691,7 @@ out:
>  	return -EIO;
>  }
>  
> -static void scrub_fixup_nodatasum(struct btrfs_work *work)
> +static void scrub_fixup_nodatasum(struct work_struct *work)
>  {
>  	int ret;
>  	struct scrub_fixup_nodatasum *fixup;
> @@ -956,9 +956,8 @@ nodatasum_case:
>  		fixup_nodatasum->root = fs_info->extent_root;
>  		fixup_nodatasum->mirror_num = failed_mirror_index + 1;
>  		scrub_pending_trans_workers_inc(sctx);
> -		fixup_nodatasum->work.func = scrub_fixup_nodatasum;
> -		btrfs_queue_worker(&fs_info->scrub_workers,
> -				   &fixup_nodatasum->work);
> +		INIT_WORK(&fixup_nodatasum->work, scrub_fixup_nodatasum);
> +		queue_work(fs_info->scrub_workers, &fixup_nodatasum->work);
>  		goto out;
>  	}
>  
> @@ -1592,11 +1591,11 @@ static void scrub_wr_bio_end_io(struct bio *bio, int err)
>  	sbio->err = err;
>  	sbio->bio = bio;
>  
> -	sbio->work.func = scrub_wr_bio_end_io_worker;
> -	btrfs_queue_worker(&fs_info->scrub_wr_completion_workers, &sbio->work);
> +	INIT_WORK(&sbio->work, scrub_wr_bio_end_io_worker);
> +	queue_work(fs_info->scrub_wr_completion_workers, &sbio->work);
>  }
>  
> -static void scrub_wr_bio_end_io_worker(struct btrfs_work *work)
> +static void scrub_wr_bio_end_io_worker(struct work_struct *work)
>  {
>  	struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
>  	struct scrub_ctx *sctx = sbio->sctx;
> @@ -2061,10 +2060,10 @@ static void scrub_bio_end_io(struct bio *bio, int err)
>  	sbio->err = err;
>  	sbio->bio = bio;
>  
> -	btrfs_queue_worker(&fs_info->scrub_workers, &sbio->work);
> +	queue_work(fs_info->scrub_workers, &sbio->work);
>  }
>  
> -static void scrub_bio_end_io_worker(struct btrfs_work *work)
> +static void scrub_bio_end_io_worker(struct work_struct *work)
>  {
>  	struct scrub_bio *sbio = container_of(work, struct scrub_bio, work);
>  	struct scrub_ctx *sctx = sbio->sctx;
> @@ -2778,33 +2777,26 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
>  						int is_dev_replace)
>  {
>  	int ret = 0;
> +	int flags = WQ_UNBOUND | WQ_MEM_RECLAIM;
> +	int max_active = fs_info->thread_pool_size;
>  
>  	mutex_lock(&fs_info->scrub_lock);
>  	if (fs_info->scrub_workers_refcnt == 0) {
>  		if (is_dev_replace)
> -			btrfs_init_workers(&fs_info->scrub_workers, "scrub", 1,
> -					&fs_info->generic_worker);
> +			fs_info->scrub_workers =
> +				alloc_workqueue("scrub", flags, 1);
>  		else
> -			btrfs_init_workers(&fs_info->scrub_workers, "scrub",
> -					fs_info->thread_pool_size,
> -					&fs_info->generic_worker);
> -		fs_info->scrub_workers.idle_thresh = 4;
> -		ret = btrfs_start_workers(&fs_info->scrub_workers);
> -		if (ret)
> +			fs_info->scrub_workers =
> +				alloc_workqueue("scrub", flags, max_active);
> +		if (!fs_info->scrub_workers)

			ret = -ENOMEM;

Plus a pair of curly brackets.

The code behind the out label looks like this:

out:
        mutex_unlock(&fs_info->scrub_lock);

        return ret;
}

>  			goto out;
> -		btrfs_init_workers(&fs_info->scrub_wr_completion_workers,
> -				   "scrubwrc",
> -				   fs_info->thread_pool_size,
> -				   &fs_info->generic_worker);
> -		fs_info->scrub_wr_completion_workers.idle_thresh = 2;
> -		ret = btrfs_start_workers(
> -				&fs_info->scrub_wr_completion_workers);
> -		if (ret)
> +		fs_info->scrub_wr_completion_workers =
> +			alloc_workqueue("scrubwrc", flags, max_active);
> +		if (!fs_info->scrub_wr_completion_workers)

			ret = -ENOMEM;


>  			goto out;
> -		btrfs_init_workers(&fs_info->scrub_nocow_workers, "scrubnc", 1,
> -				   &fs_info->generic_worker);
> -		ret = btrfs_start_workers(&fs_info->scrub_nocow_workers);
> -		if (ret)
> +		fs_info->scrub_nocow_workers =
> +			alloc_workqueue("scrubnc", flags, 1);
> +		if (!fs_info->scrub_nocow_workers)

And here.


>  			goto out;
>  	}
>  	++fs_info->scrub_workers_refcnt;
> @@ -2818,9 +2810,9 @@ static noinline_for_stack void scrub_workers_put(struct btrfs_fs_info *fs_info)
>  {
>  	mutex_lock(&fs_info->scrub_lock);
>  	if (--fs_info->scrub_workers_refcnt == 0) {
> -		btrfs_stop_workers(&fs_info->scrub_workers);
> -		btrfs_stop_workers(&fs_info->scrub_wr_completion_workers);
> -		btrfs_stop_workers(&fs_info->scrub_nocow_workers);
> +		destroy_workqueue(fs_info->scrub_workers);
> +		destroy_workqueue(fs_info->scrub_wr_completion_workers);
> +		destroy_workqueue(fs_info->scrub_nocow_workers);
>  	}
>  	WARN_ON(fs_info->scrub_workers_refcnt < 0);
>  	mutex_unlock(&fs_info->scrub_lock);
> @@ -3130,14 +3122,14 @@ static int copy_nocow_pages(struct scrub_ctx *sctx, u64 logical, u64 len,
>  	nocow_ctx->len = len;
>  	nocow_ctx->mirror_num = mirror_num;
>  	nocow_ctx->physical_for_dev_replace = physical_for_dev_replace;
> -	nocow_ctx->work.func = copy_nocow_pages_worker;
> -	btrfs_queue_worker(&fs_info->scrub_nocow_workers,
> -			   &nocow_ctx->work);
> +	INIT_WORK(&nocow_ctx->work, copy_nocow_pages_worker);
> +	queue_work(fs_info->scrub_nocow_workers,
> +		   &nocow_ctx->work);
>  
>  	return 0;
>  }
>  
> -static void copy_nocow_pages_worker(struct btrfs_work *work)
> +static void copy_nocow_pages_worker(struct work_struct *work)
>  {
>  	struct scrub_copy_nocow_ctx *nocow_ctx =
>  		container_of(work, struct scrub_copy_nocow_ctx, work);
> diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
> index 8eb6191..f557ab6 100644
> --- a/fs/btrfs/super.c
> +++ b/fs/btrfs/super.c
> @@ -1177,16 +1177,19 @@ static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
>  	btrfs_set_max_workers(&fs_info->workers, new_pool_size);
>  	btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
>  	btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
> -	btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
> +	workqueue_set_max_active(fs_info->caching_workers, new_pool_size);
> +	workqueue_set_max_active(fs_info->fixup_workers, new_pool_size);
> +	workqueue_set_max_active(fs_info->endio_workers, new_pool_size);
> +	workqueue_set_max_active(fs_info->endio_meta_workers, new_pool_size);
> +	workqueue_set_max_active(fs_info->endio_meta_write_workers,
> +				 new_pool_size);
> +	workqueue_set_max_active(fs_info->endio_write_workers,
> +				 new_pool_size);
> +	workqueue_set_max_active(fs_info->endio_freespace_worker,
> +				 new_pool_size);
> +	workqueue_set_max_active(fs_info->delayed_workers, new_pool_size);
> +	workqueue_set_max_active(fs_info->readahead_workers, new_pool_size);
> +	workqueue_set_max_active(fs_info->scrub_wr_completion_workers,
>  			      new_pool_size);
>  }