Merge tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block

Pull core block updates from Jens Axboe:

 - disk events cleanup (Christoph)

 - gendisk and request queue allocation simplifications (Christoph)

 - bdev_disk_changed cleanups (Christoph)

 - IO priority improvements (Bart)

 - Chained bio completion trace fix (Edward)

 - blk-wbt fixes (Jan)

 - blk-wbt enable/disable fix (Zhang)

 - Scheduler dispatch improvements (Jan, Ming)

 - Shared tagset scheduler improvements (John)

 - BFQ updates (Paolo, Luca, Pietro)

 - BFQ lock inversion fix (Jan)

 - Documentation improvements (Kir)

 - CLONE_IO block cgroup fix (Tejun)

 - Remove of ancient and deprecated block dump feature (zhangyi)

 - Discard merge fix (Ming)

 - Misc fixes or followup fixes (Colin, Damien, Dan, Long, Max, Thomas,
   Yang)

* tag 'for-5.14/block-2021-06-29' of git://git.kernel.dk/linux-block: (129 commits)
  block: fix discard request merge
  block/mq-deadline: Remove a WARN_ON_ONCE() call
  blk-mq: update hctx->dispatch_busy in case of real scheduler
  blk: Fix lock inversion between ioc lock and bfqd lock
  bfq: Remove merged request already in bfq_requests_merged()
  block: pass a gendisk to bdev_disk_changed
  block: move bdev_disk_changed
  block: add the events* attributes to disk_attrs
  block: move the disk events code to a separate file
  block: fix trace completion for chained bio
  block/partitions/msdos: Fix typo inidicator -> indicator
  block, bfq: reset waker pointer with shared queues
  block, bfq: check waker only for queues with no in-flight I/O
  block, bfq: avoid delayed merge of async queues
  block, bfq: boost throughput by extending queue-merging times
  block, bfq: consider also creation time in delayed stable merge
  block, bfq: fix delayed stable merge check
  block, bfq: let also stably merged queues enjoy weight raising
  blk-wbt: make sure throttle is enabled properly
  blk-wbt: introduce a new disable state to prevent false positive by rwb_enabled()
  ...

1 files changed, 9 insertions, 32 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 582d2f18717e..7b06a5fa3cac 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -31,6 +31,7 @@
 #include <linux/tracehook.h>
 #include <linux/psi.h>
 #include "blk.h"
+#include "blk-ioprio.h"
 
 /*
  * blkcg_pol_mutex protects blkcg_policy[] and policy [de]activation.
@@ -1183,15 +1184,18 @@ int blkcg_init_queue(struct request_queue *q)
 	if (preloaded)
 		radix_tree_preload_end();
 
-	ret = blk_throtl_init(q);
+	ret = blk_iolatency_init(q);
 	if (ret)
 		goto err_destroy_all;
 
-	ret = blk_iolatency_init(q);
-	if (ret) {
-		blk_throtl_exit(q);
+	ret = blk_ioprio_init(q);
+	if (ret)
 		goto err_destroy_all;
-	}
+
+	ret = blk_throtl_init(q);
+	if (ret)
+		goto err_destroy_all;
+
 	return 0;
 
 err_destroy_all:
@@ -1217,32 +1221,6 @@ void blkcg_exit_queue(struct request_queue *q)
 	blk_throtl_exit(q);
 }
 
-/*
- * We cannot support shared io contexts, as we have no mean to support
- * two tasks with the same ioc in two different groups without major rework
- * of the main cic data structures.  For now we allow a task to change
- * its cgroup only if it's the only owner of its ioc.
- */
-static int blkcg_can_attach(struct cgroup_taskset *tset)
-{
-	struct task_struct *task;
-	struct cgroup_subsys_state *dst_css;
-	struct io_context *ioc;
-	int ret = 0;
-
-	/* task_lock() is needed to avoid races with exit_io_context() */
-	cgroup_taskset_for_each(task, dst_css, tset) {
-		task_lock(task);
-		ioc = task->io_context;
-		if (ioc && atomic_read(&ioc->nr_tasks) > 1)
-			ret = -EINVAL;
-		task_unlock(task);
-		if (ret)
-			break;
-	}
-	return ret;
-}
-
 static void blkcg_bind(struct cgroup_subsys_state *root_css)
 {
 	int i;
@@ -1275,7 +1253,6 @@ struct cgroup_subsys io_cgrp_subsys = {
 	.css_online = blkcg_css_online,
 	.css_offline = blkcg_css_offline,
 	.css_free = blkcg_css_free,
-	.can_attach = blkcg_can_attach,
 	.css_rstat_flush = blkcg_rstat_flush,
 	.bind = blkcg_bind,
 	.dfl_cftypes = blkcg_files,