btrfs: don't needlessly create extent-refs kernel thread

BugLink: https://bugs.launchpad.net/bugs/1850456
commit 80ed4548d0711d15ca51be5dee0ff813051cfc90 upstream.

The patch 32b593bfcb58 ("Btrfs: remove no longer used function to run
delayed refs asynchronously") removed the async delayed refs but the
thread has been created, without any use. Remove it to avoid resource
consumption.

Fixes: 32b593bfcb58 ("Btrfs: remove no longer used function to run delayed refs asynchronously")
CC: stable@vger.kernel.org # 5.2+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d9541d58ce3d7e16d1aaaedeac45ad5164ccccbb..e7a1ec075c65238fc0f20e7e7b2c880d339ac7d6 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -908,8 +908,6 @@ struct btrfs_fs_info {
        struct btrfs_workqueue *fixup_workers;
        struct btrfs_workqueue *delayed_workers;
 
-       /* the extent workers do delayed refs on the extent allocation tree */
-       struct btrfs_workqueue *extent_workers;
        struct task_struct *transaction_kthread;
        struct task_struct *cleaner_kthread;
        u32 thread_pool_size;

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 65af7eb3f7bd735cff64f7993f31c7c8d77c6806..46eac7ddf0f7a20aedf7ae592328c48f8d01b6d4 100644 (file)
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2036,7 +2036,6 @@ static void btrfs_stop_all_workers(struct btrfs_fs_info *fs_info)
        btrfs_destroy_workqueue(fs_info->readahead_workers);
        btrfs_destroy_workqueue(fs_info->flush_workers);
        btrfs_destroy_workqueue(fs_info->qgroup_rescan_workers);
-       btrfs_destroy_workqueue(fs_info->extent_workers);
        /*
         * Now that all other work queues are destroyed, we can safely destroy
         * the queues used for metadata I/O, since tasks from those other work
@@ -2242,10 +2241,6 @@ static int btrfs_init_workqueues(struct btrfs_fs_info *fs_info,
                                      max_active, 2);
        fs_info->qgroup_rescan_workers =
                btrfs_alloc_workqueue(fs_info, "qgroup-rescan", flags, 1, 0);
-       fs_info->extent_workers =
-               btrfs_alloc_workqueue(fs_info, "extent-refs", flags,
-                                     min_t(u64, fs_devices->num_devices,
-                                           max_active), 8);
 
        if (!(fs_info->workers && fs_info->delalloc_workers &&
              fs_info->submit_workers && fs_info->flush_workers &&
@@ -2256,7 +2251,6 @@ 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->readahead_workers &&
              fs_info->fixup_workers && fs_info->delayed_workers &&
-             fs_info->extent_workers &&
              fs_info->qgroup_rescan_workers)) {
                return -ENOMEM;
        }