io_uring: import 5.15-stable io_uring

No upstream commit exists.

This imports the io_uring codebase from 5.15.85, wholesale. Changes
from that code base:

- Drop IOCB_ALLOC_CACHE, we don't have that in 5.10.
- Drop MKDIRAT/SYMLINKAT/LINKAT. Would require further VFS backports,
  and we don't support these in 5.10 to begin with.
- sock_from_file() old style calling convention.
- Use compat_get_bitmap() only for CONFIG_COMPAT=y

Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

15 files changed, 6667 insertions, 5434 deletions

diff --git a/Makefile b/Makefile
index 68f8efa0cc30..14bb1bb37770 100644
--- a/Makefile
+++ b/Makefile
@@ -1128,7 +1128,7 @@ export MODORDER := $(extmod-prefix)modules.order
 export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps
 
 ifeq ($(KBUILD_EXTMOD),)
-core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
+core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/ io_uring/
 
 vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
 		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
diff --git a/fs/Makefile b/fs/Makefile
index 999d1a23f036..c660ce28f149 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -32,8 +32,6 @@ obj-$(CONFIG_TIMERFD)		+= timerfd.o
 obj-$(CONFIG_EVENTFD)		+= eventfd.o
 obj-$(CONFIG_USERFAULTFD)	+= userfaultfd.o
 obj-$(CONFIG_AIO)               += aio.o
-obj-$(CONFIG_IO_URING)		+= io_uring.o
-obj-$(CONFIG_IO_WQ)		+= io-wq.o
 obj-$(CONFIG_FS_DAX)		+= dax.o
 obj-$(CONFIG_FS_ENCRYPTION)	+= crypto/
 obj-$(CONFIG_FS_VERITY)		+= verity/
diff --git a/fs/io-wq.c b/fs/io-wq.c
deleted file mode 100644
index 3d5fc76b92d0..000000000000
--- a/fs/io-wq.c
+++ /dev/null
@@ -1,1242 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Basic worker thread pool for io_uring
- *
- * Copyright (C) 2019 Jens Axboe
- *
- */
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/errno.h>
-#include <linux/sched/signal.h>
-#include <linux/mm.h>
-#include <linux/sched/mm.h>
-#include <linux/percpu.h>
-#include <linux/slab.h>
-#include <linux/kthread.h>
-#include <linux/rculist_nulls.h>
-#include <linux/fs_struct.h>
-#include <linux/task_work.h>
-#include <linux/blk-cgroup.h>
-#include <linux/audit.h>
-#include <linux/cpu.h>
-
-#include "../kernel/sched/sched.h"
-#include "io-wq.h"
-
-#define WORKER_IDLE_TIMEOUT	(5 * HZ)
-
-enum {
-	IO_WORKER_F_UP		= 1,	/* up and active */
-	IO_WORKER_F_RUNNING	= 2,	/* account as running */
-	IO_WORKER_F_FREE	= 4,	/* worker on free list */
-	IO_WORKER_F_FIXED	= 8,	/* static idle worker */
-	IO_WORKER_F_BOUND	= 16,	/* is doing bounded work */
-};
-
-enum {
-	IO_WQ_BIT_EXIT		= 0,	/* wq exiting */
-	IO_WQ_BIT_CANCEL	= 1,	/* cancel work on list */
-	IO_WQ_BIT_ERROR		= 2,	/* error on setup */
-};
-
-enum {
-	IO_WQE_FLAG_STALLED	= 1,	/* stalled on hash */
-};
-
-/*
- * One for each thread in a wqe pool
- */
-struct io_worker {
-	refcount_t ref;
-	unsigned flags;
-	struct hlist_nulls_node nulls_node;
-	struct list_head all_list;
-	struct task_struct *task;
-	struct io_wqe *wqe;
-
-	struct io_wq_work *cur_work;
-	spinlock_t lock;
-
-	struct rcu_head rcu;
-	struct mm_struct *mm;
-#ifdef CONFIG_BLK_CGROUP
-	struct cgroup_subsys_state *blkcg_css;
-#endif
-	const struct cred *cur_creds;
-	const struct cred *saved_creds;
-	struct files_struct *restore_files;
-	struct nsproxy *restore_nsproxy;
-	struct fs_struct *restore_fs;
-};
-
-#if BITS_PER_LONG == 64
-#define IO_WQ_HASH_ORDER	6
-#else
-#define IO_WQ_HASH_ORDER	5
-#endif
-
-#define IO_WQ_NR_HASH_BUCKETS	(1u << IO_WQ_HASH_ORDER)
-
-struct io_wqe_acct {
-	unsigned nr_workers;
-	unsigned max_workers;
-	atomic_t nr_running;
-};
-
-enum {
-	IO_WQ_ACCT_BOUND,
-	IO_WQ_ACCT_UNBOUND,
-};
-
-/*
- * Per-node worker thread pool
- */
-struct io_wqe {
-	struct {
-		raw_spinlock_t lock;
-		struct io_wq_work_list work_list;
-		unsigned long hash_map;
-		unsigned flags;
-	} ____cacheline_aligned_in_smp;
-
-	int node;
-	struct io_wqe_acct acct[2];
-
-	struct hlist_nulls_head free_list;
-	struct list_head all_list;
-
-	struct io_wq *wq;
-	struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS];
-};
-
-/*
- * Per io_wq state
-  */
-struct io_wq {
-	struct io_wqe **wqes;
-	unsigned long state;
-
-	free_work_fn *free_work;
-	io_wq_work_fn *do_work;
-
-	struct task_struct *manager;
-	struct user_struct *user;
-	refcount_t refs;
-	struct completion done;
-
-	struct hlist_node cpuhp_node;
-
-	refcount_t use_refs;
-};
-
-static enum cpuhp_state io_wq_online;
-
-static bool io_worker_get(struct io_worker *worker)
-{
-	return refcount_inc_not_zero(&worker->ref);
-}
-
-static void io_worker_release(struct io_worker *worker)
-{
-	if (refcount_dec_and_test(&worker->ref))
-		wake_up_process(worker->task);
-}
-
-/*
- * Note: drops the wqe->lock if returning true! The caller must re-acquire
- * the lock in that case. Some callers need to restart handling if this
- * happens, so we can't just re-acquire the lock on behalf of the caller.
- */
-static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker)
-{
-	bool dropped_lock = false;
-
-	if (worker->saved_creds) {
-		revert_creds(worker->saved_creds);
-		worker->cur_creds = worker->saved_creds = NULL;
-	}
-
-	if (current->files != worker->restore_files) {
-		__acquire(&wqe->lock);
-		raw_spin_unlock_irq(&wqe->lock);
-		dropped_lock = true;
-
-		task_lock(current);
-		current->files = worker->restore_files;
-		current->nsproxy = worker->restore_nsproxy;
-		task_unlock(current);
-	}
-
-	if (current->fs != worker->restore_fs)
-		current->fs = worker->restore_fs;
-
-	/*
-	 * If we have an active mm, we need to drop the wq lock before unusing
-	 * it. If we do, return true and let the caller retry the idle loop.
-	 */
-	if (worker->mm) {
-		if (!dropped_lock) {
-			__acquire(&wqe->lock);
-			raw_spin_unlock_irq(&wqe->lock);
-			dropped_lock = true;
-		}
-		__set_current_state(TASK_RUNNING);
-		kthread_unuse_mm(worker->mm);
-		mmput(worker->mm);
-		worker->mm = NULL;
-	}
-
-#ifdef CONFIG_BLK_CGROUP
-	if (worker->blkcg_css) {
-		kthread_associate_blkcg(NULL);
-		worker->blkcg_css = NULL;
-	}
-#endif
-	if (current->signal->rlim[RLIMIT_FSIZE].rlim_cur != RLIM_INFINITY)
-		current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
-	return dropped_lock;
-}
-
-static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe,
-						   struct io_wq_work *work)
-{
-	if (work->flags & IO_WQ_WORK_UNBOUND)
-		return &wqe->acct[IO_WQ_ACCT_UNBOUND];
-
-	return &wqe->acct[IO_WQ_ACCT_BOUND];
-}
-
-static inline struct io_wqe_acct *io_wqe_get_acct(struct io_wqe *wqe,
-						  struct io_worker *worker)
-{
-	if (worker->flags & IO_WORKER_F_BOUND)
-		return &wqe->acct[IO_WQ_ACCT_BOUND];
-
-	return &wqe->acct[IO_WQ_ACCT_UNBOUND];
-}
-
-static void io_worker_exit(struct io_worker *worker)
-{
-	struct io_wqe *wqe = worker->wqe;
-	struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
-
-	/*
-	 * If we're not at zero, someone else is holding a brief reference
-	 * to the worker. Wait for that to go away.
-	 */
-	set_current_state(TASK_INTERRUPTIBLE);
-	if (!refcount_dec_and_test(&worker->ref))
-		schedule();
-	__set_current_state(TASK_RUNNING);
-
-	preempt_disable();
-	current->flags &= ~PF_IO_WORKER;
-	if (worker->flags & IO_WORKER_F_RUNNING)
-		atomic_dec(&acct->nr_running);
-	if (!(worker->flags & IO_WORKER_F_BOUND))
-		atomic_dec(&wqe->wq->user->processes);
-	worker->flags = 0;
-	preempt_enable();
-
-	raw_spin_lock_irq(&wqe->lock);
-	hlist_nulls_del_rcu(&worker->nulls_node);
-	list_del_rcu(&worker->all_list);
-	if (__io_worker_unuse(wqe, worker)) {
-		__release(&wqe->lock);
-		raw_spin_lock_irq(&wqe->lock);
-	}
-	acct->nr_workers--;
-	raw_spin_unlock_irq(&wqe->lock);
-
-	kfree_rcu(worker, rcu);
-	if (refcount_dec_and_test(&wqe->wq->refs))
-		complete(&wqe->wq->done);
-}
-
-static inline bool io_wqe_run_queue(struct io_wqe *wqe)
-	__must_hold(wqe->lock)
-{
-	if (!wq_list_empty(&wqe->work_list) &&
-	    !(wqe->flags & IO_WQE_FLAG_STALLED))
-		return true;
-	return false;
-}
-
-/*
- * Check head of free list for an available worker. If one isn't available,
- * caller must wake up the wq manager to create one.
- */
-static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
-	__must_hold(RCU)
-{
-	struct hlist_nulls_node *n;
-	struct io_worker *worker;
-
-	n = rcu_dereference(hlist_nulls_first_rcu(&wqe->free_list));
-	if (is_a_nulls(n))
-		return false;
-
-	worker = hlist_nulls_entry(n, struct io_worker, nulls_node);
-	if (io_worker_get(worker)) {
-		wake_up_process(worker->task);
-		io_worker_release(worker);
-		return true;
-	}
-
-	return false;
-}
-
-/*
- * We need a worker. If we find a free one, we're good. If not, and we're
- * below the max number of workers, wake up the manager to create one.
- */
-static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
-{
-	bool ret;
-
-	/*
-	 * Most likely an attempt to queue unbounded work on an io_wq that
-	 * wasn't setup with any unbounded workers.
-	 */
-	if (unlikely(!acct->max_workers))
-		pr_warn_once("io-wq is not configured for unbound workers");
-
-	rcu_read_lock();
-	ret = io_wqe_activate_free_worker(wqe);
-	rcu_read_unlock();
-
-	if (!ret && acct->nr_workers < acct->max_workers)
-		wake_up_process(wqe->wq->manager);
-}
-
-static void io_wqe_inc_running(struct io_wqe *wqe, struct io_worker *worker)
-{
-	struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
-
-	atomic_inc(&acct->nr_running);
-}
-
-static void io_wqe_dec_running(struct io_wqe *wqe, struct io_worker *worker)
-	__must_hold(wqe->lock)
-{
-	struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
-
-	if (atomic_dec_and_test(&acct->nr_running) && io_wqe_run_queue(wqe))
-		io_wqe_wake_worker(wqe, acct);
-}
-
-static void io_worker_start(struct io_wqe *wqe, struct io_worker *worker)
-{
-	allow_kernel_signal(SIGINT);
-
-	current->flags |= PF_IO_WORKER;
-
-	worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
-	worker->restore_files = current->files;
-	worker->restore_nsproxy = current->nsproxy;
-	worker->restore_fs = current->fs;
-	io_wqe_inc_running(wqe, worker);
-}
-
-/*
- * Worker will start processing some work. Move it to the busy list, if
- * it's currently on the freelist
- */
-static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker,
-			     struct io_wq_work *work)
-	__must_hold(wqe->lock)
-{
-	bool worker_bound, work_bound;
-
-	if (worker->flags & IO_WORKER_F_FREE) {
-		worker->flags &= ~IO_WORKER_F_FREE;
-		hlist_nulls_del_init_rcu(&worker->nulls_node);
-	}
-
-	/*
-	 * If worker is moving from bound to unbound (or vice versa), then
-	 * ensure we update the running accounting.
-	 */
-	worker_bound = (worker->flags & IO_WORKER_F_BOUND) != 0;
-	work_bound = (work->flags & IO_WQ_WORK_UNBOUND) == 0;
-	if (worker_bound != work_bound) {
-		io_wqe_dec_running(wqe, worker);
-		if (work_bound) {
-			worker->flags |= IO_WORKER_F_BOUND;
-			wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers--;
-			wqe->acct[IO_WQ_ACCT_BOUND].nr_workers++;
-			atomic_dec(&wqe->wq->user->processes);
-		} else {
-			worker->flags &= ~IO_WORKER_F_BOUND;
-			wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers++;
-			wqe->acct[IO_WQ_ACCT_BOUND].nr_workers--;
-			atomic_inc(&wqe->wq->user->processes);
-		}
-		io_wqe_inc_running(wqe, worker);
-	 }
-}
-
-/*
- * No work, worker going to sleep. Move to freelist, and unuse mm if we
- * have one attached. Dropping the mm may potentially sleep, so we drop
- * the lock in that case and return success. Since the caller has to
- * retry the loop in that case (we changed task state), we don't regrab
- * the lock if we return success.
- */
-static bool __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker)
-	__must_hold(wqe->lock)
-{
-	if (!(worker->flags & IO_WORKER_F_FREE)) {
-		worker->flags |= IO_WORKER_F_FREE;
-		hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
-	}
-
-	return __io_worker_unuse(wqe, worker);
-}
-
-static inline unsigned int io_get_work_hash(struct io_wq_work *work)
-{
-	return work->flags >> IO_WQ_HASH_SHIFT;
-}
-
-static struct io_wq_work *io_get_next_work(struct io_wqe *wqe)
-	__must_hold(wqe->lock)
-{
-	struct io_wq_work_node *node, *prev;
-	struct io_wq_work *work, *tail;
-	unsigned int hash;
-
-	wq_list_for_each(node, prev, &wqe->work_list) {
-		work = container_of(node, struct io_wq_work, list);
-
-		/* not hashed, can run anytime */
-		if (!io_wq_is_hashed(work)) {
-			wq_list_del(&wqe->work_list, node, prev);
-			return work;
-		}
-
-		/* hashed, can run if not already running */
-		hash = io_get_work_hash(work);
-		if (!(wqe->hash_map & BIT(hash))) {
-			wqe->hash_map |= BIT(hash);
-			/* all items with this hash lie in [work, tail] */
-			tail = wqe->hash_tail[hash];
-			wqe->hash_tail[hash] = NULL;
-			wq_list_cut(&wqe->work_list, &tail->list, prev);
-			return work;
-		}
-	}
-
-	return NULL;
-}
-
-static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work)
-{
-	if (worker->mm) {
-		kthread_unuse_mm(worker->mm);
-		mmput(worker->mm);
-		worker->mm = NULL;
-	}
-
-	if (mmget_not_zero(work->identity->mm)) {
-		kthread_use_mm(work->identity->mm);
-		worker->mm = work->identity->mm;
-		return;
-	}
-
-	/* failed grabbing mm, ensure work gets cancelled */
-	work->flags |= IO_WQ_WORK_CANCEL;
-}
-
-static inline void io_wq_switch_blkcg(struct io_worker *worker,
-				      struct io_wq_work *work)
-{
-#ifdef CONFIG_BLK_CGROUP
-	if (!(work->flags & IO_WQ_WORK_BLKCG))
-		return;
-	if (work->identity->blkcg_css != worker->blkcg_css) {
-		kthread_associate_blkcg(work->identity->blkcg_css);
-		worker->blkcg_css = work->identity->blkcg_css;
-	}
-#endif
-}
-
-static void io_wq_switch_creds(struct io_worker *worker,
-			       struct io_wq_work *work)
-{
-	const struct cred *old_creds = override_creds(work->identity->creds);
-
-	worker->cur_creds = work->identity->creds;
-	if (worker->saved_creds)
-		put_cred(old_creds); /* creds set by previous switch */
-	else
-		worker->saved_creds = old_creds;
-}
-
-static void io_impersonate_work(struct io_worker *worker,
-				struct io_wq_work *work)
-{
-	if ((work->flags & IO_WQ_WORK_FILES) &&
-	    current->files != work->identity->files) {
-		task_lock(current);
-		current->files = work->identity->files;
-		current->nsproxy = work->identity->nsproxy;
-		task_unlock(current);
-		if (!work->identity->files) {
-			/* failed grabbing files, ensure work gets cancelled */
-			work->flags |= IO_WQ_WORK_CANCEL;
-		}
-	}
-	if ((work->flags & IO_WQ_WORK_FS) && current->fs != work->identity->fs)
-		current->fs = work->identity->fs;
-	if ((work->flags & IO_WQ_WORK_MM) && work->identity->mm != worker->mm)
-		io_wq_switch_mm(worker, work);
-	if ((work->flags & IO_WQ_WORK_CREDS) &&
-	    worker->cur_creds != work->identity->creds)
-		io_wq_switch_creds(worker, work);
-	if (work->flags & IO_WQ_WORK_FSIZE)
-		current->signal->rlim[RLIMIT_FSIZE].rlim_cur = work->identity->fsize;
-	else if (current->signal->rlim[RLIMIT_FSIZE].rlim_cur != RLIM_INFINITY)
-		current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
-	io_wq_switch_blkcg(worker, work);
-#ifdef CONFIG_AUDIT
-	current->loginuid = work->identity->loginuid;
-	current->sessionid = work->identity->sessionid;
-#endif
-}
-
-static void io_assign_current_work(struct io_worker *worker,
-				   struct io_wq_work *work)
-{
-	if (work) {
-		/* flush pending signals before assigning new work */
-		if (signal_pending(current))
-			flush_signals(current);
-		cond_resched();
-	}
-
-#ifdef CONFIG_AUDIT
-	current->loginuid = KUIDT_INIT(AUDIT_UID_UNSET);
-	current->sessionid = AUDIT_SID_UNSET;
-#endif
-
-	spin_lock_irq(&worker->lock);
-	worker->cur_work = work;
-	spin_unlock_irq(&worker->lock);
-}
-
-static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work);
-
-static void io_worker_handle_work(struct io_worker *worker)
-	__releases(wqe->lock)
-{
-	struct io_wqe *wqe = worker->wqe;
-	struct io_wq *wq = wqe->wq;
-
-	do {
-		struct io_wq_work *work;
-get_next:
-		/*
-		 * If we got some work, mark us as busy. If we didn't, but
-		 * the list isn't empty, it means we stalled on hashed work.
-		 * Mark us stalled so we don't keep looking for work when we
-		 * can't make progress, any work completion or insertion will
-		 * clear the stalled flag.
-		 */
-		work = io_get_next_work(wqe);
-		if (work)
-			__io_worker_busy(wqe, worker, work);
-		else if (!wq_list_empty(&wqe->work_list))
-			wqe->flags |= IO_WQE_FLAG_STALLED;
-
-		raw_spin_unlock_irq(&wqe->lock);
-		if (!work)
-			break;
-		io_assign_current_work(worker, work);
-
-		/* handle a whole dependent link */
-		do {
-			struct io_wq_work *old_work, *next_hashed, *linked;
-			unsigned int hash = io_get_work_hash(work);
-
-			next_hashed = wq_next_work(work);
-			io_impersonate_work(worker, work);
-			/*
-			 * OK to set IO_WQ_WORK_CANCEL even for uncancellable
-			 * work, the worker function will do the right thing.
-			 */
-			if (test_bit(IO_WQ_BIT_CANCEL, &wq->state))
-				work->flags |= IO_WQ_WORK_CANCEL;
-
-			old_work = work;
-			linked = wq->do_work(work);
-
-			work = next_hashed;
-			if (!work && linked && !io_wq_is_hashed(linked)) {
-				work = linked;
-				linked = NULL;
-			}
-			io_assign_current_work(worker, work);
-			wq->free_work(old_work);
-
-			if (linked)
-				io_wqe_enqueue(wqe, linked);
-
-			if (hash != -1U && !next_hashed) {
-				raw_spin_lock_irq(&wqe->lock);
-				wqe->hash_map &= ~BIT_ULL(hash);
-				wqe->flags &= ~IO_WQE_FLAG_STALLED;
-				/* skip unnecessary unlock-lock wqe->lock */
-				if (!work)
-					goto get_next;
-				raw_spin_unlock_irq(&wqe->lock);
-			}
-		} while (work);
-
-		raw_spin_lock_irq(&wqe->lock);
-	} while (1);
-}
-
-static int io_wqe_worker(void *data)
-{
-	struct io_worker *worker = data;
-	struct io_wqe *wqe = worker->wqe;
-	struct io_wq *wq = wqe->wq;
-
-	io_worker_start(wqe, worker);
-
-	while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
-		set_current_state(TASK_INTERRUPTIBLE);
-loop:
-		raw_spin_lock_irq(&wqe->lock);
-		if (io_wqe_run_queue(wqe)) {
-			__set_current_state(TASK_RUNNING);
-			io_worker_handle_work(worker);
-			goto loop;
-		}
-		/* drops the lock on success, retry */
-		if (__io_worker_idle(wqe, worker)) {
-			__release(&wqe->lock);
-			goto loop;
-		}
-		raw_spin_unlock_irq(&wqe->lock);
-		if (signal_pending(current))
-			flush_signals(current);
-		if (schedule_timeout(WORKER_IDLE_TIMEOUT))
-			continue;
-		/* timed out, exit unless we're the fixed worker */
-		if (test_bit(IO_WQ_BIT_EXIT, &wq->state) ||
-		    !(worker->flags & IO_WORKER_F_FIXED))
-			break;
-	}
-
-	if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
-		raw_spin_lock_irq(&wqe->lock);
-		if (!wq_list_empty(&wqe->work_list))
-			io_worker_handle_work(worker);
-		else
-			raw_spin_unlock_irq(&wqe->lock);
-	}
-
-	io_worker_exit(worker);
-	return 0;
-}
-
-/*
- * Called when a worker is scheduled in. Mark us as currently running.
- */
-void io_wq_worker_running(struct task_struct *tsk)
-{
-	struct io_worker *worker = kthread_data(tsk);
-	struct io_wqe *wqe = worker->wqe;
-
-	if (!(worker->flags & IO_WORKER_F_UP))
-		return;
-	if (worker->flags & IO_WORKER_F_RUNNING)
-		return;
-	worker->flags |= IO_WORKER_F_RUNNING;
-	io_wqe_inc_running(wqe, worker);
-}
-
-/*
- * Called when worker is going to sleep. If there are no workers currently
- * running and we have work pending, wake up a free one or have the manager
- * set one up.
- */
-void io_wq_worker_sleeping(struct task_struct *tsk)
-{
-	struct io_worker *worker = kthread_data(tsk);
-	struct io_wqe *wqe = worker->wqe;
-
-	if (!(worker->flags & IO_WORKER_F_UP))
-		return;
-	if (!(worker->flags & IO_WORKER_F_RUNNING))
-		return;
-
-	worker->flags &= ~IO_WORKER_F_RUNNING;
-
-	raw_spin_lock_irq(&wqe->lock);
-	io_wqe_dec_running(wqe, worker);
-	raw_spin_unlock_irq(&wqe->lock);
-}
-
-static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
-{
-	struct io_wqe_acct *acct = &wqe->acct[index];
-	struct io_worker *worker;
-
-	worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node);
-	if (!worker)
-		return false;
-
-	refcount_set(&worker->ref, 1);
-	worker->nulls_node.pprev = NULL;
-	worker->wqe = wqe;
-	spin_lock_init(&worker->lock);
-
-	worker->task = kthread_create_on_node(io_wqe_worker, worker, wqe->node,
-				"io_wqe_worker-%d/%d", index, wqe->node);
-	if (IS_ERR(worker->task)) {
-		kfree(worker);
-		return false;
-	}
-	kthread_bind_mask(worker->task, cpumask_of_node(wqe->node));
-
-	raw_spin_lock_irq(&wqe->lock);
-	hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
-	list_add_tail_rcu(&worker->all_list, &wqe->all_list);
-	worker->flags |= IO_WORKER_F_FREE;
-	if (index == IO_WQ_ACCT_BOUND)
-		worker->flags |= IO_WORKER_F_BOUND;
-	if (!acct->nr_workers && (worker->flags & IO_WORKER_F_BOUND))
-		worker->flags |= IO_WORKER_F_FIXED;
-	acct->nr_workers++;
-	raw_spin_unlock_irq(&wqe->lock);
-
-	if (index == IO_WQ_ACCT_UNBOUND)
-		atomic_inc(&wq->user->processes);
-
-	refcount_inc(&wq->refs);
-	wake_up_process(worker->task);
-	return true;
-}
-
-static inline bool io_wqe_need_worker(struct io_wqe *wqe, int index)
-	__must_hold(wqe->lock)
-{
-	struct io_wqe_acct *acct = &wqe->acct[index];
-
-	/* if we have available workers or no work, no need */
-	if (!hlist_nulls_empty(&wqe->free_list) || !io_wqe_run_queue(wqe))
-		return false;
-	return acct->nr_workers < acct->max_workers;
-}
-
-static bool io_wqe_worker_send_sig(struct io_worker *worker, void *data)
-{
-	send_sig(SIGINT, worker->task, 1);
-	return false;
-}
-
-/*
- * Iterate the passed in list and call the specific function for each
- * worker that isn't exiting
- */
-static bool io_wq_for_each_worker(struct io_wqe *wqe,
-				  bool (*func)(struct io_worker *, void *),
-				  void *data)
-{
-	struct io_worker *worker;
-	bool ret = false;
-
-	list_for_each_entry_rcu(worker, &wqe->all_list, all_list) {
-		if (io_worker_get(worker)) {
-			/* no task if node is/was offline */
-			if (worker->task)
-				ret = func(worker, data);
-			io_worker_release(worker);
-			if (ret)
-				break;
-		}
-	}
-
-	return ret;
-}
-
-static bool io_wq_worker_wake(struct io_worker *worker, void *data)
-{
-	wake_up_process(worker->task);
-	return false;
-}
-
-/*
- * Manager thread. Tasked with creating new workers, if we need them.
- */
-static int io_wq_manager(void *data)
-{
-	struct io_wq *wq = data;
-	int node;
-
-	/* create fixed workers */
-	refcount_set(&wq->refs, 1);
-	for_each_node(node) {
-		if (!node_online(node))
-			continue;
-		if (create_io_worker(wq, wq->wqes[node], IO_WQ_ACCT_BOUND))
-			continue;
-		set_bit(IO_WQ_BIT_ERROR, &wq->state);
-		set_bit(IO_WQ_BIT_EXIT, &wq->state);
-		goto out;
-	}
-
-	complete(&wq->done);
-
-	while (!kthread_should_stop()) {
-		if (current->task_works)
-			task_work_run();
-
-		for_each_node(node) {
-			struct io_wqe *wqe = wq->wqes[node];
-			bool fork_worker[2] = { false, false };
-
-			if (!node_online(node))
-				continue;
-
-			raw_spin_lock_irq(&wqe->lock);
-			if (io_wqe_need_worker(wqe, IO_WQ_ACCT_BOUND))
-				fork_worker[IO_WQ_ACCT_BOUND] = true;
-			if (io_wqe_need_worker(wqe, IO_WQ_ACCT_UNBOUND))
-				fork_worker[IO_WQ_ACCT_UNBOUND] = true;
-			raw_spin_unlock_irq(&wqe->lock);
-			if (fork_worker[IO_WQ_ACCT_BOUND])
-				create_io_worker(wq, wqe, IO_WQ_ACCT_BOUND);
-			if (fork_worker[IO_WQ_ACCT_UNBOUND])
-				create_io_worker(wq, wqe, IO_WQ_ACCT_UNBOUND);
-		}
-		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(HZ);
-	}
-
-	if (current->task_works)
-		task_work_run();
-
-out:
-	if (refcount_dec_and_test(&wq->refs)) {
-		complete(&wq->done);
-		return 0;
-	}
-	/* if ERROR is set and we get here, we have workers to wake */
-	if (test_bit(IO_WQ_BIT_ERROR, &wq->state)) {
-		rcu_read_lock();
-		for_each_node(node)
-			io_wq_for_each_worker(wq->wqes[node], io_wq_worker_wake, NULL);
-		rcu_read_unlock();
-	}
-	return 0;
-}
-
-static bool io_wq_can_queue(struct io_wqe *wqe, struct io_wqe_acct *acct,
-			    struct io_wq_work *work)
-{
-	bool free_worker;
-
-	if (!(work->flags & IO_WQ_WORK_UNBOUND))
-		return true;
-	if (atomic_read(&acct->nr_running))
-		return true;
-
-	rcu_read_lock();
-	free_worker = !hlist_nulls_empty(&wqe->free_list);
-	rcu_read_unlock();
-	if (free_worker)
-		return true;
-
-	if (atomic_read(&wqe->wq->user->processes) >= acct->max_workers &&
-	    !(capable(CAP_SYS_RESOURCE) || capable(CAP_SYS_ADMIN)))
-		return false;
-
-	return true;
-}
-
-static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe)
-{
-	struct io_wq *wq = wqe->wq;
-
-	do {
-		struct io_wq_work *old_work = work;
-
-		work->flags |= IO_WQ_WORK_CANCEL;
-		work = wq->do_work(work);
-		wq->free_work(old_work);
-	} while (work);
-}
-
-static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work)
-{
-	unsigned int hash;
-	struct io_wq_work *tail;
-
-	if (!io_wq_is_hashed(work)) {
-append:
-		wq_list_add_tail(&work->list, &wqe->work_list);
-		return;
-	}
-
-	hash = io_get_work_hash(work);
-	tail = wqe->hash_tail[hash];
-	wqe->hash_tail[hash] = work;
-	if (!tail)
-		goto append;
-
-	wq_list_add_after(&work->list, &tail->list, &wqe->work_list);
-}
-
-static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
-{
-	struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
-	bool do_wake;
-	unsigned long flags;
-
-	/*
-	 * Do early check to see if we need a new unbound worker, and if we do,
-	 * if we're allowed to do so. This isn't 100% accurate as there's a
-	 * gap between this check and incrementing the value, but that's OK.
-	 * It's close enough to not be an issue, fork() has the same delay.
-	 */
-	if (unlikely(!io_wq_can_queue(wqe, acct, work))) {
-		io_run_cancel(work, wqe);
-		return;
-	}
-
-	raw_spin_lock_irqsave(&wqe->lock, flags);
-	io_wqe_insert_work(wqe, work);
-	wqe->flags &= ~IO_WQE_FLAG_STALLED;
-	do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) ||
-			!atomic_read(&acct->nr_running);
-	raw_spin_unlock_irqrestore(&wqe->lock, flags);
-
-	if (do_wake)
-		io_wqe_wake_worker(wqe, acct);
-}
-
-void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
-{
-	struct io_wqe *wqe = wq->wqes[numa_node_id()];
-
-	io_wqe_enqueue(wqe, work);
-}
-
-/*
- * Work items that hash to the same value will not be done in parallel.
- * Used to limit concurrent writes, generally hashed by inode.
- */
-void io_wq_hash_work(struct io_wq_work *work, void *val)
-{
-	unsigned int bit;
-
-	bit = hash_ptr(val, IO_WQ_HASH_ORDER);
-	work->flags |= (IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT));
-}
-
-void io_wq_cancel_all(struct io_wq *wq)
-{
-	int node;
-
-	set_bit(IO_WQ_BIT_CANCEL, &wq->state);
-
-	rcu_read_lock();
-	for_each_node(node) {
-		struct io_wqe *wqe = wq->wqes[node];
-
-		io_wq_for_each_worker(wqe, io_wqe_worker_send_sig, NULL);
-	}
-	rcu_read_unlock();
-}
-
-struct io_cb_cancel_data {
-	work_cancel_fn *fn;
-	void *data;
-	int nr_running;
-	int nr_pending;
-	bool cancel_all;
-};
-
-static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
-{
-	struct io_cb_cancel_data *match = data;
-	unsigned long flags;
-
-	/*
-	 * Hold the lock to avoid ->cur_work going out of scope, caller
-	 * may dereference the passed in work.
-	 */
-	spin_lock_irqsave(&worker->lock, flags);
-	if (worker->cur_work &&
-	    !(worker->cur_work->flags & IO_WQ_WORK_NO_CANCEL) &&
-	    match->fn(worker->cur_work, match->data)) {
-		send_sig(SIGINT, worker->task, 1);
-		match->nr_running++;
-	}
-	spin_unlock_irqrestore(&worker->lock, flags);
-
-	return match->nr_running && !match->cancel_all;
-}
-
-static inline void io_wqe_remove_pending(struct io_wqe