diff options
author | Ingo Molnar <mingo@kernel.org> | 2021-02-12 13:36:43 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2021-02-12 13:36:43 +0100 |
commit | a3251c1a36f595046bea03935ebe37a1e1f1f1d7 (patch) | |
tree | 14b51f8bf1d7e1bb35697cb4704255b51b15baa9 /fs/io_uring.c | |
parent | 72f40a2823d6e16229ab58b898c6f22044e5222f (diff) | |
parent | ab234a260b1f625b26cbefa93ca365b0ae66df33 (diff) | |
download | linux-a3251c1a36f595046bea03935ebe37a1e1f1f1d7.tar.bz2 |
Merge branch 'x86/paravirt' into x86/entry
Merge in the recent paravirt changes to resolve conflicts caused
by objtool annotations.
Conflicts:
arch/x86/xen/xen-asm.S
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'fs/io_uring.c')
-rw-r--r-- | fs/io_uring.c | 209 |
1 files changed, 140 insertions, 69 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 2f305c097bd5..1f68105a41ed 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -354,6 +354,7 @@ struct io_ring_ctx { unsigned cq_entries; unsigned cq_mask; atomic_t cq_timeouts; + unsigned cq_last_tm_flush; unsigned long cq_check_overflow; struct wait_queue_head cq_wait; struct fasync_struct *cq_fasync; @@ -1024,6 +1025,8 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req, static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec, const struct iovec *fast_iov, struct iov_iter *iter, bool force); +static void io_req_drop_files(struct io_kiocb *req); +static void io_req_task_queue(struct io_kiocb *req); static struct kmem_cache *req_cachep; @@ -1047,8 +1050,7 @@ EXPORT_SYMBOL(io_uring_get_socket); static inline void io_clean_op(struct io_kiocb *req) { - if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED | - REQ_F_INFLIGHT)) + if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED)) __io_clean_op(req); } @@ -1068,14 +1070,21 @@ static bool io_match_task(struct io_kiocb *head, { struct io_kiocb *req; - if (task && head->task != task) + if (task && head->task != task) { + /* in terms of cancelation, always match if req task is dead */ + if (head->task->flags & PF_EXITING) + return true; return false; + } if (!files) return true; io_for_each_link(req, head) { - if ((req->flags & REQ_F_WORK_INITIALIZED) && - (req->work.flags & IO_WQ_WORK_FILES) && + if (!(req->flags & REQ_F_WORK_INITIALIZED)) + 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) return true; } @@ -1106,6 +1115,9 @@ static void io_sq_thread_drop_mm_files(void) static int __io_sq_thread_acquire_files(struct io_ring_ctx *ctx) { + if (current->flags & PF_EXITING) + return -EFAULT; + if (!current->files) { struct files_struct *files; struct nsproxy *nsproxy; @@ -1133,6 +1145,8 @@ static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx) { struct mm_struct *mm; + if (current->flags & PF_EXITING) + return -EFAULT; if (current->mm) return 0; @@ -1388,6 +1402,8 @@ static void io_req_clean_work(struct io_kiocb *req) free_fs_struct(fs); req->work.flags &= ~IO_WQ_WORK_FS; } + if (req->flags & REQ_F_INFLIGHT) + io_req_drop_files(req); io_put_identity(req->task->io_uring, req); } @@ -1497,11 +1513,14 @@ static bool io_grab_identity(struct io_kiocb *req) return false; atomic_inc(&id->files->count); get_nsproxy(id->nsproxy); - req->flags |= REQ_F_INFLIGHT; - spin_lock_irq(&ctx->inflight_lock); - list_add(&req->inflight_entry, &ctx->inflight_list); - spin_unlock_irq(&ctx->inflight_lock); + if (!(req->flags & REQ_F_INFLIGHT)) { + req->flags |= REQ_F_INFLIGHT; + + spin_lock_irq(&ctx->inflight_lock); + list_add(&req->inflight_entry, &ctx->inflight_list); + spin_unlock_irq(&ctx->inflight_lock); + } req->work.flags |= IO_WQ_WORK_FILES; } if (!(req->work.flags & IO_WQ_WORK_MM) && @@ -1616,37 +1635,49 @@ static void __io_queue_deferred(struct io_ring_ctx *ctx) do { struct io_defer_entry *de = list_first_entry(&ctx->defer_list, struct io_defer_entry, list); - struct io_kiocb *link; if (req_need_defer(de->req, de->seq)) break; list_del_init(&de->list); - /* punt-init is done before queueing for defer */ - link = __io_queue_async_work(de->req); - if (link) { - __io_queue_linked_timeout(link); - /* drop submission reference */ - io_put_req_deferred(link, 1); - } + io_req_task_queue(de->req); kfree(de); } while (!list_empty(&ctx->defer_list)); } static void io_flush_timeouts(struct io_ring_ctx *ctx) { - while (!list_empty(&ctx->timeout_list)) { + u32 seq; + + if (list_empty(&ctx->timeout_list)) + return; + + seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); + + do { + u32 events_needed, events_got; struct io_kiocb *req = list_first_entry(&ctx->timeout_list, struct io_kiocb, timeout.list); if (io_is_timeout_noseq(req)) break; - if (req->timeout.target_seq != ctx->cached_cq_tail - - atomic_read(&ctx->cq_timeouts)) + + /* + * Since seq can easily wrap around over time, subtract + * the last seq at which timeouts were flushed before comparing. + * Assuming not more than 2^31-1 events have happened since, + * these subtractions won't have wrapped, so we can check if + * target is in [last_seq, current_seq] by comparing the two. + */ + events_needed = req->timeout.target_seq - ctx->cq_last_tm_flush; + events_got = seq - ctx->cq_last_tm_flush; + if (events_got < events_needed) break; list_del_init(&req->timeout.list); io_kill_timeout(req); - } + } while (!list_empty(&ctx->timeout_list)); + + ctx->cq_last_tm_flush = seq; } static void io_commit_cqring(struct io_ring_ctx *ctx) @@ -1742,12 +1773,13 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force, struct io_kiocb *req, *tmp; struct io_uring_cqe *cqe; unsigned long flags; - bool all_flushed; + bool all_flushed, posted; LIST_HEAD(list); if (!force && __io_cqring_events(ctx) == rings->cq_ring_entries) return false; + posted = false; spin_lock_irqsave(&ctx->completion_lock, flags); list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) { if (!io_match_task(req, tsk, files)) @@ -1767,6 +1799,7 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force, WRITE_ONCE(ctx->rings->cq_overflow, ctx->cached_cq_overflow); } + posted = true; } all_flushed = list_empty(&ctx->cq_overflow_list); @@ -1776,9 +1809,11 @@ static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force, ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW; } - io_commit_cqring(ctx); + if (posted) + io_commit_cqring(ctx); spin_unlock_irqrestore(&ctx->completion_lock, flags); - io_cqring_ev_posted(ctx); + if (posted) + io_cqring_ev_posted(ctx); while (!list_empty(&list)) { req = list_first_entry(&list, struct io_kiocb, compl.list); @@ -2170,6 +2205,9 @@ static void __io_req_task_submit(struct io_kiocb *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) @@ -2245,6 +2283,8 @@ static void io_req_free_batch_finish(struct io_ring_ctx *ctx, struct io_uring_task *tctx = rb->task->io_uring; percpu_counter_sub(&tctx->inflight, rb->task_refs); + if (atomic_read(&tctx->in_idle)) + wake_up(&tctx->wait); put_task_struct_many(rb->task, rb->task_refs); rb->task = NULL; } @@ -2263,6 +2303,8 @@ static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req) struct io_uring_task *tctx = rb->task->io_uring; percpu_counter_sub(&tctx->inflight, rb->task_refs); + if (atomic_read(&tctx->in_idle)) + wake_up(&tctx->wait); put_task_struct_many(rb->task, rb->task_refs); } rb->task = req->task; @@ -3523,7 +3565,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, /* read it all, or we did blocking attempt. no retry. */ if (!iov_iter_count(iter) || !force_nonblock || - (req->file->f_flags & O_NONBLOCK)) + (req->file->f_flags & O_NONBLOCK) || !(req->flags & REQ_F_ISREG)) goto done; io_size -= ret; @@ -4443,7 +4485,6 @@ static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) * io_wq_work.flags, so initialize io_wq_work firstly. */ io_req_init_async(req); - req->work.flags |= IO_WQ_WORK_NO_CANCEL; if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) return -EINVAL; @@ -4476,6 +4517,8 @@ static int io_close(struct io_kiocb *req, bool force_nonblock, /* if the file has a flush method, be safe and punt to async */ if (close->put_file->f_op->flush && force_nonblock) { + /* not safe to cancel at this point */ + req->work.flags |= IO_WQ_WORK_NO_CANCEL; /* was never set, but play safe */ req->flags &= ~REQ_F_NOWAIT; /* avoid grabbing files - we don't need the files */ @@ -5832,6 +5875,12 @@ static int io_timeout(struct io_kiocb *req) tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts); req->timeout.target_seq = tail + off; + /* Update the last seq here in case io_flush_timeouts() hasn't. + * This is safe because ->completion_lock is held, and submissions + * and completions are never mixed in the same ->completion_lock section. + */ + ctx->cq_last_tm_flush = tail; + /* * Insertion sort, ensuring the first entry in the list is always * the one we need first. @@ -6126,8 +6175,10 @@ static void io_req_drop_files(struct io_kiocb *req) struct io_uring_task *tctx = req->task->io_uring; unsigned long flags; - put_files_struct(req->work.identity->files); - put_nsproxy(req->work.identity->nsproxy); + if (req->work.flags & IO_WQ_WORK_FILES) { + put_files_struct(req->work.identity->files); + put_nsproxy(req->work.identity->nsproxy); + } spin_lock_irqsave(&ctx->inflight_lock, flags); list_del(&req->inflight_entry); spin_unlock_irqrestore(&ctx->inflight_lock, flags); @@ -6194,9 +6245,6 @@ static void __io_clean_op(struct io_kiocb *req) } req->flags &= ~REQ_F_NEED_CLEANUP; } - - if (req->flags & REQ_F_INFLIGHT) - io_req_drop_files(req); } static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock, @@ -6415,6 +6463,16 @@ static struct file *io_file_get(struct io_submit_state *state, file = __io_file_get(state, fd); } + if (file && file->f_op == &io_uring_fops && + !(req->flags & REQ_F_INFLIGHT)) { + io_req_init_async(req); + req->flags |= REQ_F_INFLIGHT; + + spin_lock_irq(&ctx->inflight_lock); + list_add(&req->inflight_entry, &ctx->inflight_list); + spin_unlock_irq(&ctx->inflight_lock); + } + return file; } @@ -7056,6 +7114,7 @@ static int io_sq_thread(void *data) 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; @@ -7093,6 +7152,7 @@ static int io_sq_thread(void *data) } io_run_task_work(); + io_sq_thread_drop_mm_files(); if (cur_css) io_sq_thread_unassociate_blkcg(); @@ -7212,14 +7272,18 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, TASK_INTERRUPTIBLE); /* make sure we run task_work before checking for signals */ ret = io_run_task_work_sig(); - if (ret > 0) + if (ret > 0) { + finish_wait(&ctx->wait, &iowq.wq); continue; + } else if (ret < 0) break; if (io_should_wake(&iowq)) break; - if (test_bit(0, &ctx->cq_check_overflow)) + if (test_bit(0, &ctx->cq_check_overflow)) { + finish_wait(&ctx->wait, &iowq.wq); continue; + } if (uts) { timeout = schedule_timeout(timeout); if (timeout == 0) { @@ -8811,39 +8875,44 @@ static void io_cancel_defer_files(struct io_ring_ctx *ctx, } } +static int io_uring_count_inflight(struct io_ring_ctx *ctx, + struct task_struct *task, + struct files_struct *files) +{ + struct io_kiocb *req; + int cnt = 0; + + spin_lock_irq(&ctx->inflight_lock); + list_for_each_entry(req, &ctx->inflight_list, inflight_entry) + cnt += io_match_task(req, task, files); + spin_unlock_irq(&ctx->inflight_lock); + return cnt; +} + static void io_uring_cancel_files(struct io_ring_ctx *ctx, struct task_struct *task, struct files_struct *files) { while (!list_empty_careful(&ctx->inflight_list)) { struct io_task_cancel cancel = { .task = task, .files = files }; - struct io_kiocb *req; DEFINE_WAIT(wait); - bool found = false; - - spin_lock_irq(&ctx->inflight_lock); - list_for_each_entry(req, &ctx->inflight_list, inflight_entry) { - if (req->task != task || - req->work.identity->files != files) - continue; - found = true; - break; - } - if (found) - prepare_to_wait(&task->io_uring->wait, &wait, - TASK_UNINTERRUPTIBLE); - spin_unlock_irq(&ctx->inflight_lock); + int inflight; - /* We need to keep going until we don't find a matching req */ - if (!found) + inflight = io_uring_count_inflight(ctx, task, files); + if (!inflight) break; io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true); io_poll_remove_all(ctx, task, files); io_kill_timeouts(ctx, task, files); + io_cqring_overflow_flush(ctx, true, task, files); /* cancellations _may_ trigger task work */ io_run_task_work(); - schedule(); + + prepare_to_wait(&task->io_uring->wait, &wait, + TASK_UNINTERRUPTIBLE); + if (inflight == io_uring_count_inflight(ctx, task, files)) + schedule(); finish_wait(&task->io_uring->wait, &wait); } } @@ -8881,14 +8950,13 @@ static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx, static void io_disable_sqo_submit(struct io_ring_ctx *ctx) { - WARN_ON_ONCE(ctx->sqo_task != current); - mutex_lock(&ctx->uring_lock); ctx->sqo_dead = 1; mutex_unlock(&ctx->uring_lock); /* make sure callers enter the ring to get error */ - io_ring_set_wakeup_flag(ctx); + if (ctx->rings) + io_ring_set_wakeup_flag(ctx); } /* @@ -8902,7 +8970,6 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, struct task_struct *task = current; if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { - /* for SQPOLL only sqo_task has task notes */ io_disable_sqo_submit(ctx); task = ctx->sq_data->thread; atomic_inc(&task->io_uring->in_idle); @@ -8912,19 +8979,12 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx, io_cancel_defer_files(ctx, task, files); io_cqring_overflow_flush(ctx, true, task, files); + io_uring_cancel_files(ctx, task, files); if (!files) __io_uring_cancel_task_requests(ctx, task); - else - io_uring_cancel_files(ctx, task, files); if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) { atomic_dec(&task->io_uring->in_idle); - /* - * If the files that are going away are the ones in the thread - * identity, clear them out. - */ - if (task->io_uring->identity->files == files) - task->io_uring->identity->files = NULL; io_sq_thread_unpark(ctx->sq_data); } } @@ -9048,6 +9108,10 @@ void __io_uring_task_cancel(void) /* make sure overflow events are dropped */ atomic_inc(&tctx->in_idle); + /* trigger io_disable_sqo_submit() */ + if (tctx->sqpoll) + __io_uring_files_cancel(NULL); + do { /* read completions before cancelations */ inflight = tctx_inflight(tctx); @@ -9058,12 +9122,12 @@ void __io_uring_task_cancel(void) prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE); /* - * If we've seen completions, retry. This avoids a race where - * a completion comes in before we did prepare_to_wait(). + * If we've seen completions, retry without waiting. This + * avoids a race where a completion comes in before we did + * prepare_to_wait(). */ - if (inflight != tctx_inflight(tctx)) - continue; - schedule(); + if (inflight == tctx_inflight(tctx)) + schedule(); finish_wait(&tctx->wait, &wait); } while (1); @@ -9077,6 +9141,9 @@ 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; + if (fatal_signal_pending(current) || (current->flags & PF_EXITING)) + io_uring_cancel_task_requests(ctx, NULL); + if (!tctx) return 0; @@ -9093,7 +9160,10 @@ static int io_uring_flush(struct file *file, void *data) if (ctx->flags & IORING_SETUP_SQPOLL) { /* there is only one file note, which is owned by sqo_task */ - WARN_ON_ONCE((ctx->sqo_task == current) == + WARN_ON_ONCE(ctx->sqo_task != current && + xa_load(&tctx->xa, (unsigned long)file)); + /* sqo_dead check is for when this happens after cancellation */ + WARN_ON_ONCE(ctx->sqo_task == current && !ctx->sqo_dead && !xa_load(&tctx->xa, (unsigned long)file)); io_disable_sqo_submit(ctx); @@ -9700,6 +9770,7 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p, */ ret = io_uring_install_fd(ctx, file); if (ret < 0) { + io_disable_sqo_submit(ctx); /* fput will clean it up */ fput(file); return ret; |