diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/io-wq.c | 621 | ||||
| -rw-r--r-- | fs/io-wq.h | 35 | ||||
| -rw-r--r-- | fs/io_uring.c | 1043 | ||||
| -rw-r--r-- | fs/proc/self.c | 7 | ||||
| -rw-r--r-- | fs/proc/thread_self.c | 7 |
5 files changed, 661 insertions, 1052 deletions
diff --git a/fs/io-wq.c b/fs/io-wq.c index c36bbcd823ce..44e20248805a 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -13,13 +13,9 @@ #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 <linux/tracehook.h> #include "../kernel/sched/sched.h" #include "io-wq.h" @@ -36,7 +32,6 @@ enum { enum { IO_WQ_BIT_EXIT = 0, /* wq exiting */ - IO_WQ_BIT_ERROR = 1, /* error on setup */ }; enum { @@ -57,14 +52,12 @@ struct io_worker { 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 nsproxy *restore_nsproxy; + + struct completion ref_done; + + struct rcu_head rcu; }; #if BITS_PER_LONG == 64 @@ -93,7 +86,6 @@ 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; @@ -103,6 +95,8 @@ struct io_wqe { struct hlist_nulls_head free_list; struct list_head all_list; + struct wait_queue_entry wait; + struct io_wq *wq; struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS]; }; @@ -119,12 +113,15 @@ struct io_wq { struct task_struct *manager; struct user_struct *user; + + struct io_wq_hash *hash; + refcount_t refs; struct completion done; struct hlist_node cpuhp_node; - refcount_t use_refs; + pid_t task_pid; }; static enum cpuhp_state io_wq_online; @@ -137,62 +134,7 @@ static bool io_worker_get(struct io_worker *worker) 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) { - __acquire(&wqe->lock); - raw_spin_unlock_irq(&wqe->lock); - dropped_lock = true; - - task_lock(current); - current->files = NULL; - current->nsproxy = worker->restore_nsproxy; - task_unlock(current); - } - - if (current->fs) - current->fs = NULL; - - /* - * 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; + complete(&worker->ref_done); } static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe, @@ -204,9 +146,10 @@ static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe, 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) +static inline struct io_wqe_acct *io_wqe_get_acct(struct io_worker *worker) { + struct io_wqe *wqe = worker->wqe; + if (worker->flags & IO_WORKER_F_BOUND) return &wqe->acct[IO_WQ_ACCT_BOUND]; @@ -216,39 +159,36 @@ static inline struct io_wqe_acct *io_wqe_get_acct(struct io_wqe *wqe, 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); + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + unsigned flags; - /* - * 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); + if (refcount_dec_and_test(&worker->ref)) + complete(&worker->ref_done); + wait_for_completion(&worker->ref_done); preempt_disable(); current->flags &= ~PF_IO_WORKER; - if (worker->flags & IO_WORKER_F_RUNNING) + flags = worker->flags; + worker->flags = 0; + if (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(); + if (worker->saved_creds) { + revert_creds(worker->saved_creds); + worker->cur_creds = worker->saved_creds = NULL; + } + raw_spin_lock_irq(&wqe->lock); - hlist_nulls_del_rcu(&worker->nulls_node); + if (flags & IO_WORKER_F_FREE) + 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); + io_wq_put(wqe->wq); } static inline bool io_wqe_run_queue(struct io_wqe *wqe) @@ -306,33 +246,27 @@ static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct) wake_up_process(wqe->wq->manager); } -static void io_wqe_inc_running(struct io_wqe *wqe, struct io_worker *worker) +static void io_wqe_inc_running(struct io_worker *worker) { - struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker); + struct io_wqe_acct *acct = io_wqe_get_acct(worker); atomic_inc(&acct->nr_running); } -static void io_wqe_dec_running(struct io_wqe *wqe, struct io_worker *worker) +static void io_wqe_dec_running(struct io_worker *worker) __must_hold(wqe->lock) { - struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker); + struct io_wqe_acct *acct = io_wqe_get_acct(worker); + struct io_wqe *wqe = worker->wqe; 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) +static void io_worker_start(struct io_worker *worker) { - allow_kernel_signal(SIGINT); - - current->flags |= PF_IO_WORKER; - current->fs = NULL; - current->files = NULL; - worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING); - worker->restore_nsproxy = current->nsproxy; - io_wqe_inc_running(wqe, worker); + io_wqe_inc_running(worker); } /* @@ -357,19 +291,17 @@ static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker, 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); + io_wqe_dec_running(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); + io_wqe_inc_running(worker); } } @@ -380,15 +312,17 @@ static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker, * 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) +static void __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); + if (worker->saved_creds) { + revert_creds(worker->saved_creds); + worker->cur_creds = worker->saved_creds = NULL; + } } static inline unsigned int io_get_work_hash(struct io_wq_work *work) @@ -396,14 +330,31 @@ static inline unsigned int io_get_work_hash(struct io_wq_work *work) return work->flags >> IO_WQ_HASH_SHIFT; } +static void io_wait_on_hash(struct io_wqe *wqe, unsigned int hash) +{ + struct io_wq *wq = wqe->wq; + + spin_lock(&wq->hash->wait.lock); + if (list_empty(&wqe->wait.entry)) { + __add_wait_queue(&wq->hash->wait, &wqe->wait); + if (!test_bit(hash, &wq->hash->map)) { + __set_current_state(TASK_RUNNING); + list_del_init(&wqe->wait.entry); + } + } + spin_unlock(&wq->hash->wait.lock); +} + 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; + unsigned int stall_hash = -1U; wq_list_for_each(node, prev, &wqe->work_list) { + unsigned int hash; + work = container_of(node, struct io_wq_work, list); /* not hashed, can run anytime */ @@ -412,111 +363,60 @@ static struct io_wq_work *io_get_next_work(struct io_wqe *wqe) 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]; + /* all items with this hash lie in [work, tail] */ + tail = wqe->hash_tail[hash]; + + /* hashed, can run if not already running */ + if (!test_and_set_bit(hash, &wqe->wq->hash->map)) { wqe->hash_tail[hash] = NULL; wq_list_cut(&wqe->work_list, &tail->list, prev); return work; } + if (stall_hash == -1U) + stall_hash = hash; + /* fast forward to a next hash, for-each will fix up @prev */ + node = &tail->list; } - 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 (stall_hash != -1U) { + raw_spin_unlock(&wqe->lock); + io_wait_on_hash(wqe, stall_hash); + raw_spin_lock(&wqe->lock); } - 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; + return NULL; } -static inline void io_wq_switch_blkcg(struct io_worker *worker, - struct io_wq_work *work) +static void io_flush_signals(void) { -#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; + if (unlikely(test_tsk_thread_flag(current, TIF_NOTIFY_SIGNAL))) { + if (current->task_works) + task_work_run(); + clear_tsk_thread_flag(current, TIF_NOTIFY_SIGNAL); } -#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); + const struct cred *old_creds = override_creds(work->creds); - worker->cur_creds = work->identity->creds; + worker->cur_creds = work->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); + io_flush_signals(); 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); @@ -550,6 +450,7 @@ get_next: if (!work) break; io_assign_current_work(worker, work); + __set_current_state(TASK_RUNNING); /* handle a whole dependent link */ do { @@ -557,7 +458,8 @@ get_next: unsigned int hash = io_get_work_hash(work); next_hashed = wq_next_work(work); - io_impersonate_work(worker, work); + if (work->creds && worker->cur_creds != work->creds) + io_wq_switch_creds(worker, work); wq->do_work(work); io_assign_current_work(worker, NULL); @@ -572,8 +474,10 @@ get_next: io_wqe_enqueue(wqe, linked); if (hash != -1U && !next_hashed) { + clear_bit(hash, &wq->hash->map); + if (wq_has_sleeper(&wq->hash->wait)) + wake_up(&wq->hash->wait); 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) @@ -592,27 +496,23 @@ static int io_wqe_worker(void *data) struct io_wqe *wqe = worker->wqe; struct io_wq *wq = wqe->wq; - io_worker_start(wqe, worker); + io_worker_start(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; - } + __io_worker_idle(wqe, worker); raw_spin_unlock_irq(&wqe->lock); - if (signal_pending(current)) - flush_signals(current); + io_flush_signals(); if (schedule_timeout(WORKER_IDLE_TIMEOUT)) continue; + if (fatal_signal_pending(current)) + break; /* timed out, exit unless we're the fixed worker */ if (test_bit(IO_WQ_BIT_EXIT, &wq->state) || !(worker->flags & IO_WORKER_F_FIXED)) @@ -636,15 +536,16 @@ loop: */ void io_wq_worker_running(struct task_struct *tsk) { - struct io_worker *worker = kthread_data(tsk); - struct io_wqe *wqe = worker->wqe; + struct io_worker *worker = tsk->pf_io_worker; + if (!worker) + return; 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); + io_wqe_inc_running(worker); } /* @@ -654,9 +555,10 @@ void io_wq_worker_running(struct task_struct *tsk) */ void io_wq_worker_sleeping(struct task_struct *tsk) { - struct io_worker *worker = kthread_data(tsk); - struct io_wqe *wqe = worker->wqe; + struct io_worker *worker = tsk->pf_io_worker; + if (!worker) + return; if (!(worker->flags & IO_WORKER_F_UP)) return; if (!(worker->flags & IO_WORKER_F_RUNNING)) @@ -664,32 +566,27 @@ void io_wq_worker_sleeping(struct task_struct *tsk) worker->flags &= ~IO_WORKER_F_RUNNING; - raw_spin_lock_irq(&wqe->lock); - io_wqe_dec_running(wqe, worker); - raw_spin_unlock_irq(&wqe->lock); + raw_spin_lock_irq(&worker->wqe->lock); + io_wqe_dec_running(worker); + raw_spin_unlock_irq(&worker->wqe->lock); } -static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index) +static int task_thread(void *data, int index) { + struct io_worker *worker = data; + struct io_wqe *wqe = worker->wqe; struct io_wqe_acct *acct = &wqe->acct[index]; - struct io_worker *worker; + struct io_wq *wq = wqe->wq; + char buf[TASK_COMM_LEN]; - worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node); - if (!worker) - return false; + sprintf(buf, "iou-wrk-%d", wq->task_pid); + set_task_comm(current, buf); - refcount_set(&worker->ref, 1); - worker->nulls_node.pprev = NULL; - worker->wqe = wqe; - spin_lock_init(&worker->lock); + current->pf_io_worker = worker; + worker->task = current; - 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)); + set_cpus_allowed_ptr(current, cpumask_of_node(wqe->node)); + current->flags |= PF_NO_SETAFFINITY; raw_spin_lock_irq(&wqe->lock); hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list); @@ -702,11 +599,63 @@ static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index) acct->nr_workers++; raw_spin_unlock_irq(&wqe->lock); - if (index == IO_WQ_ACCT_UNBOUND) - atomic_inc(&wq->user->processes); + io_wqe_worker(data); + do_exit(0); +} + +static int task_thread_bound(void *data) +{ + return task_thread(data, IO_WQ_ACCT_BOUND); +} + +static int task_thread_unbound(void *data) +{ + return task_thread(data, IO_WQ_ACCT_UNBOUND); +} + +pid_t io_wq_fork_thread(int (*fn)(void *), void *arg) +{ + unsigned long flags = CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD| + CLONE_IO|SIGCHLD; + struct kernel_clone_args args = { + .flags = ((lower_32_bits(flags) | CLONE_VM | + CLONE_UNTRACED) & ~CSIGNAL), + .exit_signal = (lower_32_bits(flags) & CSIGNAL), + .stack = (unsigned long)fn, + .stack_size = (unsigned long)arg, + }; + + return kernel_clone(&args); +} + +static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index) +{ + struct io_worker *worker; + pid_t pid; + + __set_current_state(TASK_RUNNING); + + 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); + init_completion(&worker->ref_done); refcount_inc(&wq->refs); - wake_up_process(worker->task); + + if (index == IO_WQ_ACCT_BOUND) + pid = io_wq_fork_thread(task_thread_bound, worker); + else + pid = io_wq_fork_thread(task_thread_unbound, worker); + if (pid < 0) { + io_wq_put(wq); + kfree(worker); + return false; + } return true; } @@ -752,93 +701,57 @@ static bool io_wq_worker_wake(struct io_worker *worker, void *data) return false; } -/* - * Manager thread. Tasked with creating new workers, if we need them. - */ -static int io_wq_manager(void *data) +static void io_wq_check_workers(struct io_wq *wq) { - struct io_wq *wq = data; int node; - /* create fixed workers */ - refcount_set(&wq->refs, 1); for_each_node(node) { + struct io_wqe *wqe = wq->wqes[node]; + bool fork_worker[2] = { false, false }; + 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(); + 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); } - return 0; } -static bool io_wq_can_queue(struct io_wqe *wqe, struct io_wqe_acct *acct, - struct io_wq_work *work) +/* + * Manager thread. Tasked with creating new workers, if we need them. + */ +static int io_wq_manager(void *data) { - bool free_worker; - - if (!(work->flags & IO_WQ_WORK_UNBOUND)) - return true; - if (atomic_read(&acct->nr_running)) - return true; + struct io_wq *wq = data; + char buf[TASK_COMM_LEN]; - rcu_read_lock(); - free_worker = !hlist_nulls_empty(&wqe->free_list); - rcu_read_unlock(); - if (free_worker) - return true; + sprintf(buf, "iou-mgr-%d", wq->task_pid); + set_task_comm(current, buf); + current->flags |= PF_IO_WORKER; + wq->manager = current; - if (atomic_read(&wqe->wq->user->processes) >= acct->max_workers && - !(capable(CAP_SYS_RESOURCE) || capable(CAP_SYS_ADMIN))) - return false; + complete(&wq->done); - return true; + do { + set_current_state(TASK_INTERRUPTIBLE); + io_wq_check_workers(wq); + schedule_timeout(HZ); + if (fatal_signal_pending(current)) + set_bit(IO_WQ_BIT_EXIT, &wq->state); + } while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)); + + io_wq_check_workers(wq); + wq->manager = NULL; + io_wq_put(wq); + do_exit(0); } static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe) @@ -872,20 +785,37 @@ append: wq_list_add_after(&work->list, &tail->list, &wqe->work_list); } +static int io_wq_fork_manager(struct io_wq *wq) +{ + int ret; + + if (wq->manager) + return 0; + + clear_bit(IO_WQ_BIT_EXIT, &wq->state); + refcount_inc(&wq->refs); + current->flags |= PF_IO_WORKER; + ret = io_wq_fork_thread(io_wq_manager, wq); + current->flags &= ~PF_IO_WORKER; + if (ret >= 0) { + wait_for_completion(&wq->done); + return 0; + } + + io_wq_put(wq); + return ret; +} + 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); int work_flags; 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); + /* Can only happen if manager creation fails after exec */ + if (unlikely(io_wq_fork_manager(wqe->wq))) { + work->flags |= IO_WQ_WORK_CANCEL; + wqe->wq->do_work(work); return; } @@ -939,7 +869,7 @@ static bool io_wq_worker_cancel(struct io_worker *worker, void *data) spin_lock_irqsave(&worker->lock, flags); if (worker->cur_work && match->fn(worker->cur_work, match->data)) { - send_sig(SIGINT, worker->task, 1); + set_notify_signal(worker->task); match->nr_running++; } spin_unlock_irqrestore(&worker->lock, flags); @@ -1043,6 +973,24 @@ enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, return IO_WQ_CANCEL_NOTFOUND; } +static int io_wqe_hash_wake(struct wait_queue_entry *wait, unsigned mode, + int sync, void *key) +{ + struct io_wqe *wqe = container_of(wait, struct io_wqe, wait); + int ret; + + list_del_init(&wait->entry); + + rcu_read_lock(); + ret = io_wqe_activate_free_worker(wqe); + rcu_read_unlock(); + + if (!ret) + wake_up_process(wqe->wq->manager); + + return 1; +} + struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) { int ret = -ENOMEM, node; @@ -1063,12 +1011,11 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) if (ret) goto err_wqes; + refcount_inc(&data->hash->refs); + wq->hash = data->hash; wq->free_work = data->free_work; wq->do_work = data->do_work; - /* caller must already hold a reference to this */ - wq->user = data->user; - ret = -ENOMEM; for_each_node(node) { struct io_wqe *wqe; @@ -1083,11 +1030,11 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) wqe->node = alloc_node; wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded; atomic_set(&wqe->acct[IO_WQ_ACCT_BOUND].nr_running, 0); - if (wq->user) { - wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers = + wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers = task_rlimit(current, RLIMIT_NPROC); - } atomic_set(&wqe->acct[IO_WQ_ACCT_UNBOUND].nr_running, 0); + wqe->wait.func = io_wqe_hash_wake; + INIT_LIST_HEAD(&wqe->wait.entry); wqe->wq = wq; raw_spin_lock_init(&wqe->lock); INIT_WQ_LIST(&wqe->work_list); @@ -1095,23 +1042,16 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data) INIT_LIST_HEAD(&wqe->all_list); } + wq->task_pid = current->pid; init_completion(&wq->done); + refcount_set(&wq->refs, 1); - wq->manager = kthread_create(io_wq_manager, wq, "io_wq_manager"); - if (!IS_ERR(wq->manager)) { - wake_up_process(wq->manager); - wait_for_completion(&wq->done); - if (test_bit(IO_WQ_BIT_ERROR, &wq->state)) { - ret = -ENOMEM; - goto err; - } - refcount_set(&wq->use_refs, 1); - reinit_completion(&wq->done); + ret = io_wq_fork_manager(wq); + if (!ret) return wq; - } - ret = PTR_ERR(wq->manager); - complete(&wq->done); + io_wq_put(wq); + io_wq_put_hash(data->hash); err: cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node); for_each_node(node) @@ -1123,15 +1063,7 @@ err_wq: return ERR_PTR(ret); } -bool io_wq_get(struct io_wq *wq, struct io_wq_data *data) -{ - if (data->free_work != wq->free_work || data->do_work != wq->do_work) - return false; - - return refcount_inc_not_zero(&wq->use_refs); -} - -static void __io_wq_destroy(struct io_wq *wq) +static void io_wq_destroy(struct io_wq *wq) { int node; @@ -1139,30 +1071,31 @@ static void __io_wq_destroy(struct io_wq *wq) set_bit(IO_WQ_BIT_EXIT, &wq->state); if (wq->manager) - kthread_stop(wq->manager); + wake_up_process(wq->manager); rcu_read_lock(); for_each_node(node) io_wq_for_each_worker(wq->wqes[node], io_wq_worker_wake, NULL); rcu_read_unlock(); - wait_for_completion(&wq->done); + spin_lock_irq(&wq->hash->wait.lock); + for_each_node(node) { + struct io_wqe *wqe = wq->wqes[node]; - for_each_node(node) - kfree(wq->wqes[node]); + list_del_init(&wqe->wait.entry); + kfree(wqe); + } + spin_unlock_irq(&wq->hash->wait.lock); + io_wq_put_hash(wq->hash); kfree(wq->wqes); kfree(wq); -} -void io_wq_destroy(struct io_wq *wq) -{ - if (refcount_dec_and_test(&wq->use_refs)) - __io_wq_destroy(wq); } -struct task_struct *io_wq_get_task(struct io_wq *wq) +void io_wq_put(struct io_wq *wq) { - return wq->manager; + if (refcount_dec_and_test(&wq->refs)) + io_wq_destroy(wq); } static bool io_wq_worker_affinity(struct io_worker *worker, void *data) diff --git a/fs/io-wq.h b/fs/io-wq.h index 096f1021018e..b6ca12b60c35 100644 --- a/fs/io-wq.h +++ b/fs/io-wq.h @@ -1,6 +1,7 @@ #ifndef INTERNAL_IO_WQ_H #define INTERNAL_IO_WQ_H +#include <linux/refcount.h> #include <linux/io_uring.h> struct io_wq; @@ -11,13 +12,6 @@ enum { IO_WQ_WORK_UNBOUND = 4, IO_WQ_WORK_CONCURRENT = 16, - IO_WQ_WORK_FILES = 32, - IO_WQ_WORK_FS = 64, - IO_WQ_WORK_MM = 128, - IO_WQ_WORK_CREDS = 256, - IO_WQ_WORK_BLKCG = 512, - IO_WQ_WORK_FSIZE = 1024, - IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */ }; @@ -85,7 +79,7 @@ static inline void wq_list_del(struct io_wq_work_list *list, struct io_wq_work { struct io_wq_work_node list; - struct io_identity *identity; + const struct cred *creds; unsigned flags; }; @@ -100,20 +94,32 @@ static inline struct io_wq_work *wq_next_work(struct io_wq_work *work) typedef struct io_wq_work *(free_work_fn)(struct io_wq_work *); typedef void (io_wq_work_fn)(struct io_wq_work *); -struct io_wq_data { - struct user_struct *user; +struct io_wq_hash { + refcount_t refs; + unsigned long map; + struct wait_queue_head wait; +}; +static inline void io_wq_put_hash(struct io_wq_hash *hash) +{ + if (refcount_dec_and_test(&hash->refs)) + kfree(hash); +} + +struct io_wq_data { + struct io_wq_hash *hash; io_wq_work_fn *do_work; free_work_fn *free_work; }; struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data); -bool io_wq_get(struct io_wq *wq, struct io_wq_data *data); -void io_wq_destroy(struct io_wq *wq); +void io_wq_put(struct io_wq *wq); void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work); void io_wq_hash_work(struct io_wq_work *work, void *val); +pid_t io_wq_fork_thread(int (*fn)(void *), void *arg); + static inline bool io_wq_is_hashed(struct io_wq_work *work) { return work->flags & IO_WQ_WORK_HASHED; @@ -124,8 +130,6 @@ typedef bool (work_cancel_fn)(struct io_wq_work *, void *); enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel, void *data, bool cancel_all); -struct task_struct *io_wq_get_task(struct io_wq *wq); - #if defined(CONFIG_IO_WQ) extern void io_wq_worker_sleeping(struct task_struct *); extern void io_wq_worker_running(struct task_struct *); @@ -140,6 +144,7 @@ static inline void io_wq_worker_running(struct task_struct *tsk) static inline bool io_wq_current_is_worker(void) { - return in_task() && (current->flags & PF_IO_WORKER); + return in_task() && (current->flags & PF_IO_WORKER) && + current->pf_io_worker; } #endif diff --git a/fs/io_uring.c b/fs/io_uring.c index c9f5f295c2ac..4a088581b0f2 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -57,7 +57,6 @@ #include <linux/mman.h> #include <linux/percpu.h> #include <linux/slab.h> -#include <linux/kthread.h> #include <linux/blkdev.h> #include <linux/bvec.h> #include <linux/net.h> @@ -254,6 +253,11 @@ struct io_restriction { bool registered; }; +enum { + IO_SQ_THREAD_SHOULD_STOP = 0, + IO_SQ_THREAD_SHOULD_PARK, +}; + struct io_sq_data { refcount_t refs; struct mutex lock; @@ -267,6 +271,13 @@ struct io_sq_data { struct wait_queue_head wait; unsigned sq_thread_idle; + int sq_cpu; + pid_t task_pid; + + unsigned long state; + struct completion startup; + struct completion completion; + struct completion exited; }; #define IO_IOPOLL_BATCH 8 @@ -323,12 +334,12 @@ struct io_ring_ctx { struct { unsigned int flags; unsigned int compat: 1; - unsigned int limit_mem: 1; unsigned int cq_overflow_flushed: 1; unsigned int drain_next: 1; unsigned int eventfd_async: 1; unsigned int restricted: 1; unsigned int sqo_dead: 1; + unsigned int sqo_exec: 1; /* * Ring buffer of indices into array of io_uring_sqe, which is @@ -350,6 +361,9 @@ struct io_ring_ctx { unsigned cached_cq_overflow; unsigned long sq_check_overflow; + /* hashed buffered write serialization */ + struct io_wq_hash *hash_map; + struct list_head defer_list; struct list_head timeout_list; struct list_head cq_overflow_list; @@ -366,22 +380,14 @@ struct io_ring_ctx { struct io_rings *rings; - /* IO offload */ - struct io_wq *io_wq; - /* - * For SQPOLL usage - we hold a reference to the parent task, so we - * have access to the ->files + * For SQPOLL usage */ struct task_struct *sqo_task; /* Only used for accounting purposes */ struct mm_struct *mm_account; -#ifdef CONFIG_BLK_CGROUP - struct cgroup_subsys_state *sqo_blkcg_css; -#endif - struct io_sq_data *sq_data; /* if using sq thread polling */ struct wait_queue_head sqo_sq_wait; @@ -401,13 +407,6 @@ struct io_ring_ctx { struct user_struct *user; - const struct cred *creds; - -#ifdef CONFIG_AUDIT - kuid_t loginuid; - unsigned int sessionid; -#endif - struct completion ref_comp; struct completion sq_thread_comp; @@ -456,6 +455,11 @@ struct io_ring_ctx { struct io_restriction restrictions; + /* exit task_work */ + struct callback_head *exit_task_work; + + struct wait_queue_head hash_wait; + /* Keep this last, we don't need it for the fast path */ struct work_struct exit_work; }; @@ -838,7 +842,6 @@ struct io_op_def { unsigned plug : 1; /* size of async data needed, if any */ unsigned short async_size; - unsigned work_flags; }; static const struct io_op_def io_op_defs[] = { @@ -851,7 +854,6 @@ static const struct io_op_def io_op_defs[] = { .needs_async_data = 1, .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG, }, [IORING_OP_WRITEV] = { .needs_file = 1, @@ -861,12 +863,9 @@ static const struct io_op_def io_op_defs[] = { .needs_async_data = 1, .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FSIZE, }, [IORING_OP_FSYNC] = { .needs_file = 1, - .work_flags = IO_WQ_WORK_BLKCG, }, [IORING_OP_READ_FIXED] = { .needs_file = 1, @@ -874,7 +873,6 @@ static const struct io_op_def io_op_defs[] = { .pollin = 1, .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM, }, [IORING_OP_WRITE_FIXED] = { .needs_file = 1, @@ -883,8 +881,6 @@ static const struct io_op_def io_op_defs[] = { .pollout = 1, .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE | - IO_WQ_WORK_MM, }, [IORING_OP_POLL_ADD] = { .needs_file = 1, @@ -893,7 +889,6 @@ static const struct io_op_def io_op_defs[] = { [IORING_OP_POLL_REMOVE] = {}, [IORING_OP_SYNC_FILE_RANGE] = { .needs_file = 1, - .work_flags = IO_WQ_WORK_BLKCG, }, [IORING_OP_SENDMSG] = { .needs_file = 1, @@ -901,8 +896,6 @@ static const struct io_op_def io_op_defs[] = { .pollout = 1, .needs_async_data = 1, .async_size = sizeof(struct io_async_msghdr), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FS, }, [IORING_OP_RECVMSG] = { .needs_file = 1, @@ -911,29 +904,23 @@ static const struct io_op_def io_op_defs[] = { .buffer_select = 1, .needs_async_data = 1, .async_size = sizeof(struct io_async_msghdr), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FS, }, [IORING_OP_TIMEOUT] = { .needs_async_data = 1, .async_size = sizeof(struct io_timeout_data), - .work_flags = IO_WQ_WORK_MM, }, [IORING_OP_TIMEOUT_REMOVE] = { /* used by timeout updates' prep() */ - .work_flags = IO_WQ_WORK_MM, }, [IORING_OP_ACCEPT] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES, }, [IORING_OP_ASYNC_CANCEL] = {}, [IORING_OP_LINK_TIMEOUT] = { .needs_async_data = 1, .async_size = sizeof(struct io_timeout_data), - .work_flags = IO_WQ_WORK_MM, }, [IORING_OP_CONNECT] = { .needs_file = 1, @@ -941,26 +928,14 @@ static const struct io_op_def io_op_defs[] = { .pollout = 1, .needs_async_data = 1, .async_size = sizeof(struct io_async_connect), - .work_flags = IO_WQ_WORK_MM, }, [IORING_OP_FALLOCATE] = { .needs_file = 1, - .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE, - }, - [IORING_OP_OPENAT] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FS | IO_WQ_WORK_MM, - }, - [IORING_OP_CLOSE] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG, - }, - [IORING_OP_FILES_UPDATE] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM, - }, - [IORING_OP_STATX] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM | - IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG, }, + [IORING_OP_OPENAT] = {}, + [IORING_OP_CLOSE] = {}, + [IORING_OP_FILES_UPDATE] = {}, + [IORING_OP_STATX] = {}, [IORING_OP_READ] = { .needs_file = 1, .unbound_nonreg_file = 1, @@ -968,7 +943,6 @@ static const struct io_op_def io_op_defs[] = { .buffer_select = 1, .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG, }, [IORING_OP_WRITE] = { .needs_file = 1, @@ -976,42 +950,31 @@ static const struct io_op_def io_op_defs[] = { .pollout = 1, .plug = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | - IO_WQ_WORK_FSIZE, }, [IORING_OP_FADVISE] = { .needs_file = 1, - .work_flags = IO_WQ_WORK_BLKCG, - }, - [IORING_OP_MADVISE] = { - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG, }, + [IORING_OP_MADVISE] = {}, [IORING_OP_SEND] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollout = 1, - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG, }, [IORING_OP_RECV] = { .needs_file = 1, .unbound_nonreg_file = 1, .pollin = 1, .buffer_select = 1, - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG, }, [IORING_OP_OPENAT2] = { - .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_FS | - IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM, }, [IORING_OP_EPOLL_CTL] = { .unbound_nonreg_file = 1, - .work_flags = IO_WQ_WORK_FILES, }, [IORING_OP_SPLICE] = { .needs_file = 1, .hash_reg_file = 1, .unbound_nonreg_file = 1, - .work_flags = IO_WQ_WORK_BLKCG, }, [IORING_OP_PROVIDE_BUFFERS] = {}, [IORING_OP_REMOVE_BUFFERS] = {}, @@ -1023,19 +986,14 @@ static const struct io_op_def io_op_defs[] = { [IORING_OP_SHUTDOWN] = { .needs_file = 1, }, - [IORING_OP_RENAMEAT] = { - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES | - IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG, - }, - [IORING_OP_UNLINKAT] = { - .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES | - IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG, - }, + [IORING_OP_RENAMEAT] = {}, + [IORING_OP_UNLINKAT] = {}, }; static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, struct task_struct *task, struct files_struct *files); +static void io_uring_cancel_sqpoll(struct io_ring_ctx *ctx); static void destroy_fixed_rsrc_ref_node(struct fixed_rsrc_ref_node *ref_node); static struct fixed_rsrc_ref_node *alloc_fixed_rsrc_ref_node( struct io_ring_ctx *ctx); @@ -1126,161 +1084,18 @@ static bool io_match_task(struct io_kiocb *head, continue; if (req->file && req->file->f_op == &io_uring_fops) return true; - if ((req->work.flags & IO_WQ_WORK_FILES) && - req->work.identity->files == files) + if (req->task->files == files) return true; } return false; } -static void io_sq_thread_drop_mm_files(void) -{ - struct files_struct *files = current->files; - struct mm_struct *mm = current->mm; - - if (mm) { - kthread_unuse_mm(mm); - mmput(mm); - current->mm = NULL; - } - if (files) { - struct nsproxy *nsproxy = current->nsproxy; - - task_lock(current); - current->files = NULL; - current->nsproxy = NULL; - task_unlock(current); - put_files_struct(files); - put_nsproxy(nsproxy); - } -} - -static int __io_sq_thread_acquire_files(struct io_ring_ctx *ctx) -{ - if (!current->files) { - struct files_struct *files; - struct nsproxy *nsproxy; - - task_lock(ctx->sqo_task); - files = ctx->sqo_task->files; - if (!files) { - task_unlock(ctx->sqo_task); - return -EOWNERDEAD; - } - atomic_inc(&files->count); - get_nsproxy(ctx->sqo_task->nsproxy); - nsproxy = ctx->sqo_task->nsproxy; - task_unlock(ctx->sqo_task); - - task_lock(current); - current->files = files; - current->nsproxy = nsproxy; - task_unlock(current); - } - return 0; -} - -static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx) -{ - struct mm_struct *mm; - - if (current->mm) - return 0; - - task_lock(ctx->sqo_task); - mm = ctx->sqo_task->mm; - if (unlikely(!mm || !mmget_not_zero(mm))) - mm = NULL; - task_unlock(ctx->sqo_task); - - if (mm) { - kthread_use_mm(mm); - return 0; - } - - return -EFAULT; -} - -static int __io_sq_thread_acquire_mm_files(struct io_ring_ctx *ctx, - struct io_kiocb *req) -{ - const struct io_op_def *def = &io_op_defs[req->opcode]; - int ret; - - if (def->work_flags & IO_WQ_WORK_MM) { - ret = __io_sq_thread_acquire_mm(ctx); - if (unlikely(ret)) - return ret; - } - - if (def->needs_file || (def->work_flags & IO_WQ_WORK_FILES)) { - ret = __io_sq_thread_acquire_files(ctx); - if (unlikely(ret)) - return ret; - } - - return 0; -} - -static inline int io_sq_thread_acquire_mm_files(struct io_ring_ctx *ctx, - struct io_kiocb *req) -{ - if (!(ctx->flags & IORING_SETUP_SQPOLL)) - return 0; - return __io_sq_thread_acquire_mm_files(ctx, req); -} - -static void io_sq_thread_associate_blkcg(struct io_ring_ctx *ctx, - struct cgroup_subsys_state **cur_css) - -{ -#ifdef CONFIG_BLK_CGROUP - /* puts the old one when swapping */ - if (*cur_css != ctx->sqo_blkcg_css) { - kthread_associate_blkcg(ctx->sqo_blkcg_css); - *cur_css = ctx->sqo_blkcg_css; - } -#endif -} - -static void io_sq_thread_unassociate_blkcg(void) -{ -#ifdef CONFIG_BLK_CGROUP - kthread_associate_blkcg(NULL); -#endif -} - static inline void req_set_fail_links(struct io_kiocb *req) { if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK) req->flags |= REQ_F_FAIL_LINK; } -/* - * None of these are dereferenced, they are simply used to check if any of - * them have changed. If we're under current and check they are still the - * same, we're fine to grab references to them for actual out-of-line use. - */ -static void io_init_identity(struct io_identity *id) -{ - id->files = current->files; - id->mm = current->mm; -#ifdef CONFIG_BLK_CGROUP - rcu_read_lock(); - id->blkcg_css = blkcg_css(); - rcu_read_unlock(); -#endif - id->creds = current_cred(); - id->nsproxy = current->nsproxy; - id->fs = current->fs; - id->fsize = rlimit(RLIMIT_FSIZE); -#ifdef CONFIG_AUDIT - id->loginuid = current->loginuid; - id->sessionid = current->sessionid; -#endif - refcount_set(&id->count, 1); -} - static inline void __io_req_init_async(struct io_kiocb *req) { memset(&req->work, 0, sizeof(req->work)); @@ -1293,17 +1108,10 @@ static inline void __io_req_init_async(struct io_kiocb *req) */ static inline void io_req_init_async(struct io_kiocb *req) { - struct io_uring_task *tctx = current->io_uring; - if (req->flags & REQ_F_WORK_INITIALIZED) return; __io_req_init_async(req); - - /* Grab a ref if this isn't our static identity */ - req->work.identity = tctx->identity; - if (tctx->identity != &tctx->__identity) - refcount_inc(&req->work.identity->count); } static void io_ring_ctx_ref_free(struct percpu_ref *ref) @@ -1388,40 +1196,14 @@ static bool req_need_defer(struct io_kiocb *req, u32 seq) return false; } -static void io_put_identity(struct io_uring_task *tctx, struct io_kiocb *req) -{ - if (req->work.identity == &tctx->__identity) - return; - if (refcount_dec_and_test(&req->work.identity->count)) - kfree(req->work.identity); -} - static void io_req_clean_work(struct io_kiocb *req) { if (!(req->flags & REQ_F_WORK_INITIALIZED)) return; - if (req->work.flags & IO_WQ_WORK_MM) - mmdrop(req->work.identity->mm); -#ifdef CONFIG_BLK_CGROUP - if (req->work.flags & IO_WQ_WORK_BLKCG) - css_put(req->work.identity->blkcg_css); -#endif - if (req->work.flags & IO_WQ_WORK_CREDS) - put_cred(req->work.identity->creds); - if (req->work.flags & IO_WQ_WORK_FS) { - struct fs_struct *fs = req->work.identity->fs; - - spin_lock(&req->work.identity->fs->lock); - if (--fs->users) - fs = NULL; - spin_unlock(&req->work.identity->fs->lock); - if (fs) - free_fs_struct(fs); - } - if (req->work.flags & IO_WQ_WORK_FILES) { - put_files_struct(req->work.identity->files); - put_nsproxy(req->work.identity->nsproxy); + if (req->work.creds) { + put_cred(req->work.creds); + req->work.creds = NULL; } if (req->flags & REQ_F_INFLIGHT) { struct io_ring_ctx *ctx = req->ctx; @@ -1437,54 +1219,6 @@ static void io_req_clean_work(struct io_kiocb *req) } req->flags &= ~REQ_F_WORK_INITIALIZED; - req->work.flags &= ~(IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG | IO_WQ_WORK_FS | - IO_WQ_WORK_CREDS | IO_WQ_WORK_FILES); - io_put_identity(req->task->io_uring, req); -} - -/* - * Create a private copy of io_identity, since some fields don't match - * the current context. - */ -static bool io_identity_cow(struct io_kiocb *req) -{ - struct io_uring_task *tctx = current->io_uring; - const struct cred *creds = NULL; - struct io_identity *id; - - if (req->work.flags & IO_WQ_WORK_CREDS) - creds = req->work.identity->creds; - - id = kmemdup(req->work.identity, sizeof(*id), GFP_KERNEL); - if (unlikely(!id)) { - req->work.flags |= IO_WQ_WORK_CANCEL; - return false; - } - - /* - * We can safely just re-init the creds we copied Either the field - * matches the current one, or we haven't grabbed it yet. The only - * exception is ->creds, through registered personalities, so handle - * that one separately. - */ - io_init_identity(id); - if (creds) - id->creds = creds; - - /* add one for this request */ - refcount_inc(&id->count); - - /* drop tctx and req identity references, if needed */ - if (tctx->identity != &tctx->__identity && - refcount_dec_and_test(&tctx->identity->count)) - kfree(tctx->identity); - if (req->work.identity != &tctx->__identity && - refcount_dec_and_test(&req->work.identity->count)) - kfree(req->work.identity); - - req->work.identity = id; - tctx->identity = id; - return true; } static void io_req_track_inflight(struct io_kiocb *req) @@ -1501,79 +1235,6 @@ static void io_req_track_inflight(struct io_kiocb *req) } } -static bool io_grab_identity(struct io_kiocb *req) -{ - const struct io_op_def *def = &io_op_defs[req->opcode]; - struct io_identity *id = req->work.identity; - - if (def->work_flags & IO_WQ_WORK_FSIZE) { - if (id->fsize != rlimit(RLIMIT_FSIZE)) - return false; - req->work.flags |= IO_WQ_WORK_FSIZE; - } -#ifdef CONFIG_BLK_CGROUP - if (!(req->work.flags & IO_WQ_WORK_BLKCG) && - (def->work_flags & IO_WQ_WORK_BLKCG)) { - rcu_read_lock(); - if (id->blkcg_css != blkcg_css()) { - rcu_read_unlock(); - return false; - } - /* - * This should be rare, either the cgroup is dying or the task - * is moving cgroups. Just punt to root for the handful of ios. - */ - if (css_tryget_online(id->blkcg_css)) - req->work.flags |= IO_WQ_WORK_BLKCG; - rcu_read_unlock(); - } -#endif - if (!(req->work.flags & IO_WQ_WORK_CREDS)) { - if (id->creds != current_cred()) - return false; - get_cred(id->creds); - req->work.flags |= IO_WQ_WORK_CREDS; - } -#ifdef CONFIG_AUDIT - if (!uid_eq(current->loginuid, id->loginuid) || - current->sessionid != id->sessionid) - return false; -#endif - if (!(req->work.flags & IO_WQ_WORK_FS) && - (def->work_flags & IO_WQ_WORK_FS)) { - if (current->fs != id->fs) - return false; - spin_lock(&id->fs->lock); - if (!id->fs->in_exec) { - id->fs->users++; - req->work.flags |= IO_WQ_WORK_FS; - } else { - req->work.flags |= IO_WQ_WORK_CANCEL; - } - spin_unlock(¤t->fs->lock); - } - if (!(req->work.flags & IO_WQ_WORK_FILES) && - (def->work_flags & IO_WQ_WORK_FILES) && - !(req->flags & REQ_F_NO_FILE_TABLE)) { - if (id->files != current->files || - id->nsproxy != current->nsproxy) - return false; - atomic_inc(&id->files->count); - get_nsproxy(id->nsproxy); - req->work.flags |= IO_WQ_WORK_FILES; - io_req_track_inflight(req); - } - if (!(req->work.flags & IO_WQ_WORK_MM) && - (def->work_flags & IO_WQ_WORK_MM)) { - if (id->mm != current->mm) - return false; - mmgrab(id->mm); - req->work.flags |= IO_WQ_WORK_MM; - } - - return true; -} - static void io_prep_async_work(struct io_kiocb *req) { const struct io_op_def *def = &io_op_defs[req->opcode]; @@ -1591,17 +1252,8 @@ static void io_prep_async_work(struct io_kiocb *req) if (def->unbound_nonreg_file) req->work.flags |= IO_WQ_WORK_UNBOUND; } - - /* if we fail grabbing identity, we must COW, regrab, and retry */ - if (io_grab_identity(req)) - return; - - if (!io_identity_cow(req)) - return; - - /* can't fail at this point */ - if (!io_grab_identity(req)) - WARN_ON(1); + if (!req->work.creds) + req->work.creds = get_current_cred(); } static void io_prep_async_link(struct io_kiocb *req) @@ -1616,10 +1268,14 @@ static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req) { struct io_ring_ctx *ctx = req->ctx; struct io_kiocb *link = io_prep_linked_timeout(req); + struct io_uring_task *tctx = req->task->io_uring; + + BUG_ON(!tctx); + BUG_ON(!tctx->io_wq); trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req, &req->work, req->flags); - io_wq_enqueue(ctx->io_wq, &req->work); + io_wq_enqueue(tctx->io_wq, &req->work); return link; } @@ -2313,11 +1969,14 @@ static int io_req_task_work_add(struct io_kiocb *req) static void io_req_task_work_add_fallback(struct io_kiocb *req, task_work_func_t cb) { - struct task_struct *tsk = io_wq_get_task(req->ctx->io_wq); + struct io_ring_ctx *ctx = req->ctx; + struct callback_head *head; init_task_work(&req->task_work, cb); - task_work_add(tsk, &req->task_work, TWA_NONE); - wake_up_process(tsk); + do { + head = READ_ONCE(ctx->exit_task_work); + req->task_work.next = head; + } while (cmpxchg(&ctx->exit_task_work, head, &req->task_work) != head); } static void __io_req_task_cancel(struct io_kiocb *req, int error) @@ -2351,15 +2010,11 @@ static void __io_req_task_submit(struct io_kiocb *req) /* ctx stays valid until unlock, even if we drop all ours ctx->refs */ mutex_lock(&ctx->uring_lock); - if (!ctx->sqo_dead && !(current->flags & PF_EXITING) && - !io_sq_thread_acquire_mm_files(ctx, req)) + if (!ctx->sqo_dead && !(current->flags & PF_EXITING) && !current->in_execve) __io_queue_sqe(req); else __io_req_task_cancel(req, -EFAULT); mutex_unlock(&ctx->uring_lock); - - if (ctx->flags & IORING_SETUP_SQPOLL) - io_sq_thread_drop_mm_files(); } static void io_req_task_submit(struct callback_head *cb) @@ -2823,7 +2478,6 @@ static bool io_rw_reissue(struct io_kiocb *req) { #ifdef CONFIG_BLOCK umode_t mode = file_inode(req->file)->i_mode; - int ret; if (!S_ISBLK(mode) && !S_ISREG(mode)) return false; @@ -2839,9 +2493,7 @@ static bool io_rw_reissue(struct io_kiocb *req) lockdep_assert_held(&req->ctx->uring_lock); - ret = io_sq_thread_acquire_mm_files(req->ctx, req); - - if (!ret && io_resubmit_prep(req)) { + if (io_resubmit_prep(req)) { refcount_inc(&req->refs); io_queue_async_work(req); return true; @@ -5946,12 +5598,15 @@ static bool io_cancel_cb(struct io_wq_work *work, void *data) return req->user_data == (unsigned long) data; } -static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr) +static int io_async_cancel_one(struct io_uring_task *tctx, void *sqe_addr) { enum io_wq_cancel cancel_ret; int ret = 0; - cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr, false); + if (!tctx->io_wq) + return -ENOENT; + + cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, sqe_addr, false); switch (cancel_ret) { case IO_WQ_CANCEL_OK: ret = 0; @@ -5974,7 +5629,8 @@ static void io_async_find_and_cancel(struct io_ring_ctx *ctx, unsigned long flags; int ret; - ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr); + ret = io_async_cancel_one(req->task->io_uring, + (void *) (unsigned long) sqe_addr); if (ret != -ENOENT) { spin_lock_irqsave(&ctx->completion_lock, flags); goto done; @@ -6563,10 +6219,9 @@ static void __io_queue_sqe(struct io_kiocb *req) const struct cred *old_creds = NULL; int ret; - if ((req->flags & REQ_F_WORK_INITIALIZED) && - (req->work.flags & IO_WQ_WORK_CREDS) && - req->work.identity->creds != current_cred()) - old_creds = override_creds(req->work.identity->creds); + if ((req->flags & REQ_F_WORK_INITIALIZED) && req->work.creds && + req->work.creds != current_cred()) + old_creds = override_creds(req->work.creds); ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER); @@ -6684,9 +6339,6 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, if (unlikely(req->opcode >= IORING_OP_LAST)) return -EINVAL; - if (unlikely(io_sq_thread_acquire_mm_files(ctx, req))) - return -EFAULT; - if (unlikely(!io_check_restriction(ctx, req, sqe_flags))) return -EACCES; @@ -6696,17 +6348,11 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, id = READ_ONCE(sqe->personality); if (id) { - struct io_identity *iod; - - iod = idr_find(&ctx->personality_idr, id); - if (unlikely(!iod)) - return -EINVAL; - refcount_inc(&iod->count); - __io_req_init_async(req); - get_cred(iod->creds); - req->work.identity = iod; - req->work.flags |= IO_WQ_WORK_CREDS; + req->work.creds = idr_find(&ctx->personality_idr, id); + if (unlikely(!req->work.creds)) + return -EINVAL; + get_cred(req->work.creds); } state = &ctx->submit_state; @@ -7008,71 +6654,97 @@ static void io_sqd_init_new(struct io_sq_data *sqd) io_sqd_update_thread_idle(sqd); } +static bool io_sq_thread_should_stop(struct io_sq_data *sqd) +{ + return test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); +} + +static bool io_sq_thread_should_park(struct io_sq_data *sqd) +{ + return test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); +} + +static void io_sq_thread_parkme(struct io_sq_data *sqd) +{ + for (;;) { + /* + * TASK_PARKED is a special state; we must serialize against + * possible pending wakeups to avoid store-store collisions on + * task->state. + * + * Such a collision might possibly result in the task state + * changin from TASK_PARKED and us failing the + * wait_task_inactive() in kthread_park(). + */ + set_special_state(TASK_PARKED); + if (!test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state)) + break; + + /* + * Thread is going to call schedule(), do not preempt it, + * or the caller of kthread_park() may spend more time in + * wait_task_inactive(). + */ + preempt_disable(); + complete(&sqd->completion); + schedule_preempt_disabled(); + preempt_enable(); + } + __set_current_state(TASK_RUNNING); +} + static int io_sq_thread(void *data) { - struct cgroup_subsys_state *cur_css = NULL; - struct files_struct *old_files = current->files; - struct nsproxy *old_nsproxy = current->nsproxy; - const struct cred *old_cred = NULL; struct io_sq_data *sqd = data; struct io_ring_ctx *ctx; unsigned long timeout = 0; + char buf[TASK_COMM_LEN]; DEFINE_WAIT(wait); - task_lock(current); - current->files = NULL; - current->nsproxy = NULL; - task_unlock(current); + sprintf(buf, "iou-sqp-%d", sqd->task_pid); + set_task_comm(current, buf); + sqd->thread = current; + current->pf_io_worker = NULL; + + if (sqd->sq_cpu != -1) + set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu)); + else + set_cpus_allowed_ptr(current, cpu_online_mask); + current->flags |= PF_NO_SETAFFINITY; + + complete(&sqd->completion); - while (!kthread_should_stop()) { + wait_for_completion(&sqd->startup); + + while (!io_sq_thread_should_stop(sqd)) { int ret; bool cap_entries, sqt_spin, needs_sched; /* * Any changes to the sqd lists are synchronized through the - * kthread parking. This synchronizes the thread vs users, + * thread parking. This synchronizes the thread vs users, * the users are synchronized on the sqd->ctx_lock. */ - if (kthread_should_park()) { - kthread_parkme(); - /* - * When sq thread is unparked, in case the previous park operation - * comes from io_put_sq_data(), which means that sq thread is going - * to be stopped, so here needs to have a check. - */ - if (kthread_should_stop()) - break; + if (io_sq_thread_should_park(sqd)) { + io_sq_thread_parkme(sqd); + continue; } - if (unlikely(!list_empty(&sqd->ctx_new_list))) { io_sqd_init_new(sqd); timeout = jiffies + sqd->sq_thread_idle; } - + if (fatal_signal_pending(current)) + break; sqt_spin = false; cap_entries = !list_is_singular(&sqd->ctx_list); list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { - if (current->cred != ctx->creds) { - if (old_cred) - revert_creds(old_cred); - old_cred = override_creds(ctx->creds); - } - io_sq_thread_associate_blkcg(ctx, &cur_css); -#ifdef CONFIG_AUDIT - current->loginuid = ctx->loginuid; - current->sessionid = ctx->sessionid; -#endif - ret = __io_sq_thread(ctx, cap_entries); if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list))) sqt_spin = true; - - io_sq_thread_drop_mm_files(); } if (sqt_spin || !time_after(jiffies, timeout)) { io_run_task_work(); - io_sq_thread_drop_mm_files(); cond_resched(); if (sqt_spin) timeout = jiffies + sqd->sq_thread_idle; @@ -7093,7 +6765,7 @@ static int io_sq_thread(void *data) } } - if (needs_sched && !kthread_should_park()) { + if (needs_sched && !io_sq_thread_should_park(sqd)) { list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) io_ring_set_wakeup_flag(ctx); @@ -7106,22 +6778,25 @@ static int io_sq_thread(void *data) timeout = jiffies + sqd->sq_thread_idle; } - io_run_task_work(); - io_sq_thread_drop_mm_files(); - - if (cur_css) - io_sq_thread_unassociate_blkcg(); - if (old_cred) - revert_creds(old_cred); + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) + io_uring_cancel_sqpoll(ctx); - task_lock(current); - current->files = old_files; - current->nsproxy = old_nsproxy; - task_unlock(current); + io_run_task_work(); - kthread_parkme(); + /* + * Clear thread under lock so that concurrent parks work correctly + */ + complete_all(&sqd->completion); + mutex_lock(&sqd->lock); + sqd->thread = NULL; + list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { + ctx->sqo_exec = 1; + io_ring_set_wakeup_flag(ctx); + } + mutex_unlock(&sqd->lock); - return 0; + complete(&sqd->exited); + do_exit(0); } struct io_wait_queue { @@ -7413,20 +7088,74 @@ static int io_sqe_files_unregister(struct io_ring_ctx *ctx) return 0; } +static void io_sq_thread_unpark(struct io_sq_data *sqd) + __releases(&sqd->lock) +{ + if (!sqd->thread) + return; + if (sqd->thread == current) + return; + clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); + wake_up_state(sqd->thread, TASK_PARKED); + mutex_unlock(&sqd->lock); +} + +static bool io_sq_thread_park(struct io_sq_data *sqd) + __acquires(&sqd->lock) +{ + if (sqd->thread == current) + return true; + mutex_lock(&sqd->lock); + if (!sqd->thread) { + mutex_unlock(&sqd->lock); + return false; + } + set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state); + wake_up_process(sqd->thread); + wait_for_completion(&sqd->completion); + return true; +} + +static void io_sq_thread_stop(struct io_sq_data *sqd) +{ + if (!sqd->thread) + return; + + set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); + WARN_ON_ONCE(test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state)); + wake_up_process(sqd->thread); + wait_for_completion(&sqd->exited); +} + static void io_put_sq_data(struct io_sq_data *sqd) { if (refcount_dec_and_test(&sqd->refs)) { - /* - * The park is a bit of a work-around, without it we get - * warning spews on shutdown with SQPOLL set and affinity - * set to a single CPU. - */ + io_sq_thread_stop(sqd); + kfree(sqd); + } +} + +static void io_sq_thread_finish(struct io_ring_ctx *ctx) +{ + struct io_sq_data *sqd = ctx->sq_data; + + if (sqd) { + complete(&sqd->startup); if (sqd->thread) { - kthread_park(sqd->thread); - kthread_stop(sqd->thread); + wait_for_completion(&ctx->sq_thread_comp); + io_sq_thread_park(sqd); } - kfree(sqd); + mutex_lock(&sqd->ctx_lock); + list_del(&ctx->sqd_list); + io_sqd_update_thread_idle(sqd); + mutex_unlock(&sqd->ctx_lock); + + if (sqd->thread) + io_sq_thread_unpark(sqd); + + io_put_sq_data(sqd); + ctx->sq_data = NULL; } } @@ -7473,68 +7202,12 @@ static struct io_sq_data *io_get_sq_data(struct io_uring_params *p) mutex_init(&sqd->ctx_lock); mutex_init(&sqd->lock); init_waitqueue_head(&sqd->wait); + init_completion(&sqd->startup); + init_completion(&sqd->completion); + init_completion(&sqd->exited); return sqd; } -static void io_sq_thread_unpark(struct io_sq_data *sqd) - __releases(&sqd->lock) -{ - if (!sqd->thread) - return; - kthread_unpark(sqd->thread); - mutex_unlock(&sqd->lock); -} - -static void io_sq_thread_park(struct io_sq_data *sqd) - __acquires(&sqd->lock) -{ - if (!sqd->thread) - return; - mutex_lock(&sqd->lock); - kthread_park(sqd->thread); -} - -static void io_sq_thread_stop(struct io_ring_ctx *ctx) -{ - struct io_sq_data *sqd = ctx->sq_data; - - if (sqd) { - if (sqd->thread) { - /* - * We may arrive here from the error branch in - * io_sq_offload_create() where the kthread is created - * without being waked up, thus wake it up now to make - * sure the wait will complete. - */ - wake_up_process(sqd->thread); - wait_for_completion(&ctx->sq_thread_comp); - - io_sq_thread_park(sqd); - } - - mutex_lock(&sqd->ctx_lock); - list_del(&ctx->sqd_list); - io_sqd_update_thread_idle(sqd); - mutex_unlock(&sqd->ctx_lock); - - if (sqd->thread) - io_sq_thread_unpark(sqd); - - io_put_sq_data(sqd); - ctx->sq_data = NULL; - } -} - -static void io_finish_async(struct io_ring_ctx *ctx) -{ - io_sq_thread_stop(ctx); - - if (ctx->io_wq) { - io_wq_destroy(ctx->io_wq); - ctx->io_wq = NULL; - } -} - #if defined(CONFIG_UNIX) /* * Ensure the UNIX gc is aware of our file set, so we are certain that @@ -7561,7 +7234,7 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) skb->sk = sk; nr_files = 0; - fpl->user = get_uid(ctx->user); + fpl->user = get_uid(current_user()); for (i = 0; i < nr; i++) { struct file *file = io_file_from_index(ctx, i + offset); @@ -8093,54 +7766,34 @@ static struct io_wq_work *io_free_work(struct io_wq_work *work) return req ? &req->work : NULL; } -static int io_init_wq_offload(struct io_ring_ctx *ctx, - struct io_uring_params *p) +static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx) { + struct io_wq_hash *hash; struct io_wq_data data; - struct fd f; - struct io_ring_ctx *ctx_attach; unsigned int concurrency; - int ret = 0; - - data.user = ctx->user; - data.free_work = io_free_work; - data.do_work = io_wq_submit_work; - - if (!(p->flags & IORING_SETUP_ATTACH_WQ)) { - /* Do QD, or 4 * CPUS, whatever is smallest */ - concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); - ctx->io_wq = io_wq_create(concurrency, &data); - if (IS_ERR(ctx->io_wq)) { - ret = PTR_ERR(ctx->io_wq); - ctx->io_wq = NULL; - } - return ret; + hash = ctx->hash_map; + if (!hash) { + hash = kzalloc(sizeof(*hash), GFP_KERNEL); + if (!hash) + return ERR_PTR(-ENOMEM); + refcount_set(&hash->refs, 1); + init_waitqueue_head(&hash->wait); + ctx->hash_map = hash; } - f = fdget(p->wq_fd); - if (!f.file) - return -EBADF; - - if (f.file->f_op != &io_uring_fops) { - ret = -EINVAL; - goto out_fput; - } + data.hash = hash; + data.free_work = io_free_work; + data.do_work = io_wq_submit_work; - ctx_attach = f.file->private_data; - /* @io_wq is protected by holding the fd */ - if (!io_wq_get(ctx_attach->io_wq, &data)) { - ret = -EINVAL; - goto out_fput; - } + /* Do QD, or 4 * CPUS, whatever is smallest */ + concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); - ctx->io_wq = ctx_attach->io_wq; -out_fput: - fdput(f); - return ret; + return io_wq_create(concurrency, &data); } -static int io_uring_alloc_task_context(struct task_struct *task) +static int io_uring_alloc_task_context(struct task_struct *task, + struct io_ring_ctx *ctx) { struct io_uring_task *tctx; int ret; @@ -8155,13 +7808,19 @@ static int io_uring_alloc_task_context(struct task_struct *task) return ret; } + tctx->io_wq = io_init_wq_offload(ctx); + if (IS_ERR(tctx->io_wq)) { + ret = PTR_ERR(tctx->io_wq); + percpu_counter_destroy(&tctx->inflight); + kfree(tctx); + return ret; + } + xa_init(&tctx->xa); init_waitqueue_head(&tctx->wait); tctx->last = NULL; atomic_set(&tctx->in_idle, 0); tctx->sqpoll = false; - io_init_identity(&tctx->__identity); - tctx->identity = &tctx->__identity; task->io_uring = tctx; spin_lock_init(&tctx->task_lock); INIT_WQ_LIST(&tctx->task_list); @@ -8175,19 +7834,49 @@ void __io_uring_free(struct task_struct *tsk) struct io_uring_task *tctx = tsk->io_uring; WARN_ON_ONCE(!xa_empty(&tctx->xa)); - WARN_ON_ONCE(refcount_read(&tctx->identity->count) != 1); - if (tctx->identity != &tctx->__identity) - kfree(tctx->identity); percpu_counter_destroy(&tctx->inflight); kfree(tctx); tsk->io_uring = NULL; } +static int io_sq_thread_fork(struct io_sq_data *sqd, struct io_ring_ctx *ctx) +{ + int ret; + + clear_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state); + reinit_completion(&sqd->completion); + ctx->sqo_dead = ctx->sqo_exec = 0; + sqd->task_pid = current->pid; + current->flags |= PF_IO_WORKER; + ret = io_wq_fork_thread(io_sq_thread, sqd); + current->flags &= ~PF_IO_WORKER; + if (ret < 0) { + sqd->thread = NULL; + return ret; + } + wait_for_completion(&sqd->completion); + return io_uring_alloc_task_context(sqd->thread, ctx); +} + static int io_sq_offload_create(struct io_ring_ctx *ctx, struct io_uring_params *p) { int ret; + /* Retain compatibility with failing for an invalid attach attempt */ + if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) == + IORING_SETUP_ATTACH_WQ) { + struct fd f; + + f = fdget(p->wq_fd); + if (!f.file) + return -ENXIO; + if (f.file->f_op != &io_uring_fops) { + fdput(f); + return -EINVAL; + } + fdput(f); + } if (ctx->flags & IORING_SETUP_SQPOLL) { struct io_sq_data *sqd; @@ -8213,7 +7902,7 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, ctx->sq_thread_idle = HZ; if (sqd->thread) - goto done; + return 0; if (p->flags & IORING_SETUP_SQ_AFF) { int cpu = p->sq_thread_cpu; @@ -8224,18 +7913,21 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, if (!cpu_online(cpu)) goto err; - sqd->thread = kthread_create_on_cpu(io_sq_thread, sqd, - cpu, "io_uring-sq"); + sqd->sq_cpu = cpu; } else { - sqd->thread = kthread_create(io_sq_thread, sqd, - "io_uring-sq"); + sqd->sq_cpu = -1; } - if (IS_ERR(sqd->thread)) { - ret = PTR_ERR(sqd->thread); + + sqd->task_pid = current->pid; + current->flags |= PF_IO_WORKER; + ret = io_wq_fork_thread(io_sq_thread, sqd); + current->flags &= ~PF_IO_WORKER; + if (ret < 0) { sqd->thread = NULL; goto err; } - ret = io_uring_alloc_task_context(sqd->thread); + wait_for_completion(&sqd->completion); + ret = io_uring_alloc_task_context(sqd->thread, ctx); if (ret) goto err; } else if (p->flags & IORING_SETUP_SQ_AFF) { @@ -8244,14 +7936,9 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx, goto err; } -done: - ret = io_init_wq_offload(ctx, p); - if (ret) - goto err; - return 0; err: - io_finish_async(ctx); + io_sq_thread_finish(ctx); return ret; } @@ -8259,8 +7946,8 @@ static void io_sq_offload_start(struct io_ring_ctx *ctx) { struct io_sq_data *sqd = ctx->sq_data; - if ((ctx->flags & IORING_SETUP_SQPOLL) && sqd->thread) - wake_up_process(sqd->thread); + if (ctx->flags & IORING_SETUP_SQPOLL) + complete(&sqd->startup); } static inline void __io_unaccount_mem(struct user_struct *user, @@ -8290,7 +7977,7 @@ static inline int __io_account_mem(struct user_struct *user, static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) { - if (ctx->limit_mem) + if (ctx->user) __io_unaccount_mem(ctx->user, nr_pages); if (ctx->mm_account) @@ -8301,7 +7988,7 @@ static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) { int ret; - if (ctx->limit_mem) { + if (ctx->user) { ret = __io_account_mem(ctx->user, nr_pages); if (ret) return ret; @@ -8730,21 +8417,14 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) mutex_lock(&ctx->uring_lock); mutex_unlock(&ctx->uring_lock); - io_finish_async(ctx); + io_sq_thread_finish(ctx); io_sqe_buffers_unregister(ctx); - if (ctx->sqo_task) { - put_task_struct(ctx->sqo_task); - ctx->sqo_task = NULL; + if (ctx->mm_account) { mmdrop(ctx->mm_account); ctx->mm_account = NULL; } -#ifdef CONFIG_BLK_CGROUP - if (ctx->sqo_blkcg_css) - css_put(ctx->sqo_blkcg_css); -#endif - mutex_lock(&ctx->uring_lock); io_sqe_files_unregister(ctx); mutex_unlock(&ctx->uring_lock); @@ -8764,8 +8444,9 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx) percpu_ref_exit(&ctx->refs); free_uid(ctx->user); - put_cred(ctx->creds); io_req_caches_free(ctx, NULL); + if (ctx->hash_map) + io_wq_put_hash(ctx->hash_map); kfree(ctx->cancel_hash); kfree(ctx); } @@ -8812,13 +8493,11 @@ static int io_uring_fasync(int fd, struct file *file, int on) static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id) { - struct io_identity *iod; + const struct cred *creds; - iod = idr_remove(&ctx->personality_idr, id); - if (iod) { - put_cred(iod->creds); - if (refcount_dec_and_test(&iod->count)) - kfree(iod); + creds = idr_remove(&ctx->personality_idr, id); + if (creds) { + put_cred(creds); return 0; } @@ -8833,6 +8512,28 @@ static int io_remove_personalities(int id, void *p, void *data) return 0; } +static void io_run_ctx_fallback(struct io_ring_ctx *ctx) +{ + struct callback_head *work, *head, *next; + + do { + do { + head = NULL; + work = READ_ONCE(ctx->exit_task_work); + } while (cmpxchg(&ctx->exit_task_work, work, head) != work); + + if (!work) + break; + + do { + next = work->next; + work->func(work); + work = next; + cond_resched(); + } while (work); + } while (1); +} + static void io_ring_exit_work(struct work_struct *work) { struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, @@ -8846,17 +8547,11 @@ static void io_ring_exit_work(struct work_struct *work) */ do { io_uring_try_cancel_requests(ctx, NULL, NULL); + io_run_ctx_fallback(ctx); } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20)); io_ring_ctx_free(ctx); } -static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data) -{ - struct io_kiocb *req = container_of(work, struct io_kiocb, work); - - return req->ctx == data; -} - static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) { mutex_lock(&ctx->uring_lock); @@ -8875,9 +8570,6 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) io_kill_timeouts(ctx, NULL, NULL); io_poll_remove_all(ctx, NULL, NULL); - if (ctx->io_wq) - io_wq_cancel_cb(ctx->io_wq, io_cancel_ctx_cb, ctx, true); - /* if we failed setting up the ctx, we might not have any rings */ io_iopoll_try_reap_events(ctx); @@ -8956,13 +8648,14 @@ static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx, struct files_struct *files) { struct io_task_cancel cancel = { .task = task, .files = files, }; + struct io_uring_task *tctx = current->io_uring; while (1) { enum io_wq_cancel cret; bool ret = false; - if (ctx->io_wq) { - cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, + if (tctx && tctx->io_wq) { + cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb, &cancel, true); ret |= (cret != IO_WQ_CANCEL_NOTFOUND); } @@ -9045,12 +8738,15 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, struct files_struct *files) { struct task_struct *task = current; + bool did_park = false; if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { io_disable_sqo_submit(ctx); - task = ctx->sq_data->thread; - atomic_inc(&task->io_uring->in_idle); - io_sq_thread_park(ctx->sq_data); + did_park = io_sq_thread_park(ctx->sq_data); + if (did_park) { + task = ctx->sq_data->thread; + atomic_inc(&task->io_uring->in_idle); + } } io_cancel_defer_files(ctx, task, files); @@ -9059,7 +8755,7 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, if (!files) io_uring_try_cancel_requests(ctx, task, NULL); - if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { + if (did_park) { atomic_dec(&task->io_uring->in_idle); io_sq_thread_unpark(ctx->sq_data); } @@ -9074,7 +8770,7 @@ static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file) int ret; if (unlikely(!tctx)) { - ret = io_uring_alloc_task_context(current); + ret = io_uring_alloc_task_context(current, ctx); if (unlikely(ret)) return ret; tctx = current->io_uring; @@ -9144,8 +8840,13 @@ void __io_uring_files_cancel(struct files_struct *files) io_uring_cancel_task_requests(file->private_data, files); atomic_dec(&tctx->in_idle); - if (files) + if (files) { io_uring_remove_task_files(tctx); + if (tctx->io_wq) { + io_wq_put(tctx->io_wq); + tctx->io_wq = NULL; + } + } } static s64 tctx_inflight(struct io_uring_task *tctx) @@ -9155,14 +8856,17 @@ static s64 tctx_inflight(struct io_uring_task *tctx) static void io_uring_cancel_sqpoll(struct io_ring_ctx *ctx) { + struct io_sq_data *sqd = ctx->sq_data; struct io_uring_task *tctx; s64 inflight; DEFINE_WAIT(wait); - if (!ctx->sq_data) + if (!sqd) return; - tctx = ctx->sq_data->thread->io_uring; io_disable_sqo_submit(ctx); + if (!io_sq_thread_park(sqd)) + return; + tctx = ctx->sq_data->thread->io_uring; atomic_inc(&tctx->in_idle); do { @@ -9183,6 +8887,7 @@ static void io_uring_cancel_sqpoll(struct io_ring_ctx *ctx) finish_wait(&tctx->wait, &wait); } while (1); atomic_dec(&tctx->in_idle); + io_sq_thread_unpark(sqd); } /* @@ -9236,11 +8941,17 @@ static int io_uring_flush(struct file *file, void *data) struct io_uring_task *tctx = current->io_uring; struct io_ring_ctx *ctx = file->private_data; + /* Ignore helper thread files exit */ + if (current->flags & PF_IO_WORKER) + return 0; + if (fatal_signal_pending(current) || (current->flags & PF_EXITING)) { io_uring_cancel_task_requests(ctx, NULL); io_req_caches_free(ctx, current); } + io_run_ctx_fallback(ctx); + if (!tctx) return 0; @@ -9439,6 +9150,12 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, if (ctx->flags & IORING_SETUP_SQPOLL) { io_cqring_overflow_flush(ctx, false, NULL, NULL); + if (unlikely(ctx->sqo_exec)) { + ret = io_sq_thread_fork(ctx->sq_data, ctx); + if (ret) + goto out; + ctx->sqo_exec = 0; + } ret = -EOWNERDEAD; if (unlikely(ctx->sqo_dead)) goto out; @@ -9495,8 +9212,7 @@ out_fput: #ifdef CONFIG_PROC_FS static int io_uring_show_cred(int id, void *p, void *data) { - struct io_identity *iod = p; - const struct cred *cred = iod->creds; + const struct cred *cred = p; struct seq_file *m = data; struct user_namespace *uns = seq_user_ns(m); struct group_info *gi; @@ -9541,8 +9257,11 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) */ has_lock = mutex_trylock(&ctx->uring_lock); - if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) + if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) { sq = ctx->sq_data; + if (!sq->thread) + sq = NULL; + } seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1); seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1); @@ -9702,7 +9421,6 @@ static struct file *io_uring_get_file(struct io_ring_ctx *ctx) static int io_uring_create(unsigned entries, struct io_uring_params *p, struct io_uring_params __user *params) { - struct user_struct *user = NULL; struct io_ring_ctx *ctx; struct file *file; int ret; @@ -9744,22 +9462,13 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, p->cq_entries = 2 * p->sq_entries; } - user = get_uid(current_user()); - ctx = io_ring_ctx_alloc(p); - if (!ctx) { - free_uid(user); + if (!ctx) return -ENOMEM; - } ctx->compat = in_compat_syscall(); - ctx->limit_mem = !capable(CAP_IPC_LOCK); - ctx->user = user; - ctx->creds = get_current_cred(); -#ifdef CONFIG_AUDIT - ctx->loginuid = current->loginuid; - ctx->sessionid = current->sessionid; -#endif - ctx->sqo_task = get_task_struct(current); + if (!capable(CAP_IPC_LOCK)) + ctx->user = get_uid(current_user()); + ctx->sqo_task = current; /* * This is just grabbed for accounting purposes. When a process exits, @@ -9770,24 +9479,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, mmgrab(current->mm); ctx->mm_account = current->mm; -#ifdef CONFIG_BLK_CGROUP - /* - * The sq thread will belong to the original cgroup it was inited in. - * If the cgroup goes offline (e.g. disabling the io controller), then - * issued bios will be associated with the closest cgroup later in the - * block layer. - */ - rcu_read_lock(); - ctx->sqo_blkcg_css = blkcg_css(); - ret = css_tryget_online(ctx->sqo_blkcg_css); - rcu_read_unlock(); - if (!ret) { - /* don't init against a dying cgroup, have the user try again */ - ctx->sqo_blkcg_css = NULL; - ret = -ENODEV; - goto err; - } -#endif ret = io_allocate_scq_urings(ctx, p); if (ret) goto err; @@ -9821,7 +9512,7 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS | IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL | IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED | - IORING_FEAT_EXT_ARG; + IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS; if (copy_to_user(params, p, sizeof(*p))) { ret = -EFAULT; @@ -9927,21 +9618,15 @@ out: static int io_register_personality(struct io_ring_ctx *ctx) { - struct io_identity *id; + const struct cred *creds; int ret; - id = kmalloc(sizeof(*id), GFP_KERNEL); - if (unlikely(!id)) - return -ENOMEM; - - io_init_identity(id); - id->creds = get_current_cred(); + creds = get_current_cred(); - ret = idr_alloc_cyclic(&ctx->personality_idr, id, 1, USHRT_MAX, GFP_KERNEL); - if (ret < 0) { - put_cred(id->creds); - kfree(id); - } + ret = idr_alloc_cyclic(&ctx->personality_idr, (void *) creds, 1, + USHRT_MAX, GFP_KERNEL); + if (ret < 0) + put_cred(creds); return ret; } diff --git a/fs/proc/self.c b/fs/proc/self.c index a4012154e109..72cd69bcaf4a 100644 --- a/fs/proc/self.c +++ b/fs/proc/self.c @@ -16,13 +16,6 @@ static const char *proc_self_get_link(struct dentry *dentry, pid_t tgid = task_tgid_nr_ns(current, ns); char *name; - /* - * Not currently supported. Once we can inherit all of struct pid, - * we can allow this. - */ - if (current->flags & PF_IO_WORKER) - return ERR_PTR(-EOPNOTSUPP); - if (!tgid) return ERR_PTR(-ENOENT); /* max length of unsigned int in decimal + NULL term */ diff --git a/fs/proc/thread_self.c b/fs/proc/thread_self.c index d56681d86d28..a553273fbd41 100644 --- a/fs/proc/thread_self.c +++ b/fs/proc/thread_self.c @@ -17,13 +17,6 @@ static const char *proc_thread_self_get_link(struct dentry *dentry, pid_t pid = task_pid_nr_ns(current, ns); char *name; - /* - * Not currently supported. Once we can inherit all of struct pid, - * we can allow this. - */ - if (current->flags & PF_IO_WORKER) - return ERR_PTR(-EOPNOTSUPP); - if (!pid) return ERR_PTR(-ENOENT); name = kmalloc(10 + 6 + 10 + 1, dentry ? GFP_KERNEL : GFP_ATOMIC); |