btrfs: scrub: don't go ordered workqueue for dev-replace

The workqueue fs_info->scrub_worker would go ordered workqueue if it's a
device replace operation.

However the scrub is relying on multiple workers to do data csum
verification, and we always submit several read requests in a row.

Thus there is no need to use ordered workqueue just for dev-replace.
We have extra synchronization (the main thread will always
submit-and-wait for dev-replace writes) to handle it for zoned devices.

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

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 11f943e868940e58f736438449aca3bd3c55f35b..ff2d8b89057a0988f9d07b98a7821ca4ea1d6046 100644 (file)
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2777,8 +2777,7 @@ static void scrub_workers_put(struct btrfs_fs_info *fs_info)
 /*
  * get a reference count on fs_info->scrub_workers. start worker if necessary
  */
-static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
-                                               int is_dev_replace)
+static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info)
 {
        struct workqueue_struct *scrub_workers = NULL;
        unsigned int flags = WQ_FREEZABLE | WQ_UNBOUND;
@@ -2788,10 +2787,7 @@ static noinline_for_stack int scrub_workers_get(struct btrfs_fs_info *fs_info,
        if (refcount_inc_not_zero(&fs_info->scrub_workers_refcnt))
                return 0;
 
-       if (is_dev_replace)
-               scrub_workers = alloc_ordered_workqueue("btrfs-scrub", flags);
-       else
-               scrub_workers = alloc_workqueue("btrfs-scrub", flags, max_active);
+       scrub_workers = alloc_workqueue("btrfs-scrub", flags, max_active);
        if (!scrub_workers)
                return -ENOMEM;
 
@@ -2843,7 +2839,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
        if (IS_ERR(sctx))
                return PTR_ERR(sctx);
 
-       ret = scrub_workers_get(fs_info, is_dev_replace);
+       ret = scrub_workers_get(fs_info);
        if (ret)
                goto out_free_ctx;