3581696176
Pass the waiting time for __io_napi_adjust_timeout as ktime and get rid of all timespec64 conversions. It's especially simpler since the caller already have a ktime. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/4f5b8e8eed4f53a1879e031a6712b25381adc23d.1722003776.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
3743 lines
100 KiB
C
3743 lines
100 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Shared application/kernel submission and completion ring pairs, for
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* supporting fast/efficient IO.
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*
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* A note on the read/write ordering memory barriers that are matched between
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* the application and kernel side.
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*
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* After the application reads the CQ ring tail, it must use an
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* appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
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* before writing the tail (using smp_load_acquire to read the tail will
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* do). It also needs a smp_mb() before updating CQ head (ordering the
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* entry load(s) with the head store), pairing with an implicit barrier
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* through a control-dependency in io_get_cqe (smp_store_release to
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* store head will do). Failure to do so could lead to reading invalid
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* CQ entries.
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*
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* Likewise, the application must use an appropriate smp_wmb() before
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* writing the SQ tail (ordering SQ entry stores with the tail store),
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* which pairs with smp_load_acquire in io_get_sqring (smp_store_release
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* to store the tail will do). And it needs a barrier ordering the SQ
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* head load before writing new SQ entries (smp_load_acquire to read
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* head will do).
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*
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* When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
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* needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
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* updating the SQ tail; a full memory barrier smp_mb() is needed
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* between.
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*
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* Also see the examples in the liburing library:
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*
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* git://git.kernel.dk/liburing
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*
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* io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
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* from data shared between the kernel and application. This is done both
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* for ordering purposes, but also to ensure that once a value is loaded from
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* data that the application could potentially modify, it remains stable.
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*
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* Copyright (C) 2018-2019 Jens Axboe
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* Copyright (c) 2018-2019 Christoph Hellwig
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/syscalls.h>
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#include <net/compat.h>
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#include <linux/refcount.h>
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#include <linux/uio.h>
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#include <linux/bits.h>
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#include <linux/sched/signal.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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#include <linux/fdtable.h>
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#include <linux/mm.h>
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#include <linux/mman.h>
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#include <linux/percpu.h>
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#include <linux/slab.h>
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#include <linux/bvec.h>
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#include <linux/net.h>
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#include <net/sock.h>
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#include <linux/anon_inodes.h>
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#include <linux/sched/mm.h>
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#include <linux/uaccess.h>
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#include <linux/nospec.h>
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#include <linux/fsnotify.h>
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#include <linux/fadvise.h>
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#include <linux/task_work.h>
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#include <linux/io_uring.h>
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#include <linux/io_uring/cmd.h>
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#include <linux/audit.h>
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#include <linux/security.h>
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#include <asm/shmparam.h>
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#define CREATE_TRACE_POINTS
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#include <trace/events/io_uring.h>
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#include <uapi/linux/io_uring.h>
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#include "io-wq.h"
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#include "io_uring.h"
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#include "opdef.h"
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#include "refs.h"
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#include "tctx.h"
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#include "register.h"
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#include "sqpoll.h"
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#include "fdinfo.h"
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#include "kbuf.h"
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#include "rsrc.h"
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#include "cancel.h"
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#include "net.h"
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#include "notif.h"
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#include "waitid.h"
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#include "futex.h"
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#include "napi.h"
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#include "uring_cmd.h"
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#include "msg_ring.h"
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#include "memmap.h"
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#include "timeout.h"
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#include "poll.h"
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#include "rw.h"
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#include "alloc_cache.h"
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#include "eventfd.h"
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#define IORING_MAX_ENTRIES 32768
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#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
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#define SQE_COMMON_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_LINK | \
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IOSQE_IO_HARDLINK | IOSQE_ASYNC)
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#define SQE_VALID_FLAGS (SQE_COMMON_FLAGS | IOSQE_BUFFER_SELECT | \
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IOSQE_IO_DRAIN | IOSQE_CQE_SKIP_SUCCESS)
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#define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \
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REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS | \
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REQ_F_ASYNC_DATA)
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#define IO_REQ_CLEAN_SLOW_FLAGS (REQ_F_REFCOUNT | REQ_F_LINK | REQ_F_HARDLINK |\
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IO_REQ_CLEAN_FLAGS)
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#define IO_TCTX_REFS_CACHE_NR (1U << 10)
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#define IO_COMPL_BATCH 32
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#define IO_REQ_ALLOC_BATCH 8
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struct io_defer_entry {
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struct list_head list;
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struct io_kiocb *req;
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u32 seq;
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};
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/* requests with any of those set should undergo io_disarm_next() */
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#define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL)
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#define IO_REQ_LINK_FLAGS (REQ_F_LINK | REQ_F_HARDLINK)
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/*
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* No waiters. It's larger than any valid value of the tw counter
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* so that tests against ->cq_wait_nr would fail and skip wake_up().
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*/
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#define IO_CQ_WAKE_INIT (-1U)
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/* Forced wake up if there is a waiter regardless of ->cq_wait_nr */
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#define IO_CQ_WAKE_FORCE (IO_CQ_WAKE_INIT >> 1)
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static bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
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struct task_struct *task,
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bool cancel_all);
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static void io_queue_sqe(struct io_kiocb *req);
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struct kmem_cache *req_cachep;
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static struct workqueue_struct *iou_wq __ro_after_init;
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static int __read_mostly sysctl_io_uring_disabled;
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static int __read_mostly sysctl_io_uring_group = -1;
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#ifdef CONFIG_SYSCTL
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static struct ctl_table kernel_io_uring_disabled_table[] = {
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{
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.procname = "io_uring_disabled",
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.data = &sysctl_io_uring_disabled,
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.maxlen = sizeof(sysctl_io_uring_disabled),
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.mode = 0644,
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.proc_handler = proc_dointvec_minmax,
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.extra1 = SYSCTL_ZERO,
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.extra2 = SYSCTL_TWO,
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},
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{
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.procname = "io_uring_group",
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.data = &sysctl_io_uring_group,
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.maxlen = sizeof(gid_t),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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};
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#endif
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static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
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{
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return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
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}
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static inline unsigned int __io_cqring_events_user(struct io_ring_ctx *ctx)
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{
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return READ_ONCE(ctx->rings->cq.tail) - READ_ONCE(ctx->rings->cq.head);
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}
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static bool io_match_linked(struct io_kiocb *head)
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{
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struct io_kiocb *req;
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io_for_each_link(req, head) {
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if (req->flags & REQ_F_INFLIGHT)
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return true;
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}
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return false;
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}
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/*
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* As io_match_task() but protected against racing with linked timeouts.
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* User must not hold timeout_lock.
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*/
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bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
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bool cancel_all)
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{
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bool matched;
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if (task && head->task != task)
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return false;
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if (cancel_all)
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return true;
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if (head->flags & REQ_F_LINK_TIMEOUT) {
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struct io_ring_ctx *ctx = head->ctx;
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/* protect against races with linked timeouts */
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spin_lock_irq(&ctx->timeout_lock);
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matched = io_match_linked(head);
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spin_unlock_irq(&ctx->timeout_lock);
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} else {
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matched = io_match_linked(head);
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}
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return matched;
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}
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static inline void req_fail_link_node(struct io_kiocb *req, int res)
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{
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req_set_fail(req);
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io_req_set_res(req, res, 0);
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}
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static inline void io_req_add_to_cache(struct io_kiocb *req, struct io_ring_ctx *ctx)
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{
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wq_stack_add_head(&req->comp_list, &ctx->submit_state.free_list);
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}
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static __cold void io_ring_ctx_ref_free(struct percpu_ref *ref)
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{
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struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
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complete(&ctx->ref_comp);
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}
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static __cold void io_fallback_req_func(struct work_struct *work)
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{
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struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
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fallback_work.work);
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struct llist_node *node = llist_del_all(&ctx->fallback_llist);
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struct io_kiocb *req, *tmp;
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struct io_tw_state ts = {};
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percpu_ref_get(&ctx->refs);
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mutex_lock(&ctx->uring_lock);
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llist_for_each_entry_safe(req, tmp, node, io_task_work.node)
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req->io_task_work.func(req, &ts);
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io_submit_flush_completions(ctx);
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mutex_unlock(&ctx->uring_lock);
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percpu_ref_put(&ctx->refs);
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}
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static int io_alloc_hash_table(struct io_hash_table *table, unsigned bits)
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{
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unsigned hash_buckets = 1U << bits;
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size_t hash_size = hash_buckets * sizeof(table->hbs[0]);
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table->hbs = kmalloc(hash_size, GFP_KERNEL);
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if (!table->hbs)
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return -ENOMEM;
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table->hash_bits = bits;
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init_hash_table(table, hash_buckets);
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return 0;
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}
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static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
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{
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struct io_ring_ctx *ctx;
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int hash_bits;
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bool ret;
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ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
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if (!ctx)
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return NULL;
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xa_init(&ctx->io_bl_xa);
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/*
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* Use 5 bits less than the max cq entries, that should give us around
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* 32 entries per hash list if totally full and uniformly spread, but
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* don't keep too many buckets to not overconsume memory.
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*/
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hash_bits = ilog2(p->cq_entries) - 5;
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hash_bits = clamp(hash_bits, 1, 8);
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if (io_alloc_hash_table(&ctx->cancel_table, hash_bits))
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goto err;
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if (io_alloc_hash_table(&ctx->cancel_table_locked, hash_bits))
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goto err;
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if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
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0, GFP_KERNEL))
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goto err;
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ctx->flags = p->flags;
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atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT);
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init_waitqueue_head(&ctx->sqo_sq_wait);
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INIT_LIST_HEAD(&ctx->sqd_list);
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INIT_LIST_HEAD(&ctx->cq_overflow_list);
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INIT_LIST_HEAD(&ctx->io_buffers_cache);
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ret = io_alloc_cache_init(&ctx->rsrc_node_cache, IO_NODE_ALLOC_CACHE_MAX,
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sizeof(struct io_rsrc_node));
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ret |= io_alloc_cache_init(&ctx->apoll_cache, IO_POLL_ALLOC_CACHE_MAX,
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sizeof(struct async_poll));
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ret |= io_alloc_cache_init(&ctx->netmsg_cache, IO_ALLOC_CACHE_MAX,
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sizeof(struct io_async_msghdr));
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ret |= io_alloc_cache_init(&ctx->rw_cache, IO_ALLOC_CACHE_MAX,
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sizeof(struct io_async_rw));
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ret |= io_alloc_cache_init(&ctx->uring_cache, IO_ALLOC_CACHE_MAX,
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sizeof(struct uring_cache));
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spin_lock_init(&ctx->msg_lock);
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ret |= io_alloc_cache_init(&ctx->msg_cache, IO_ALLOC_CACHE_MAX,
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sizeof(struct io_kiocb));
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ret |= io_futex_cache_init(ctx);
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if (ret)
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goto err;
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init_completion(&ctx->ref_comp);
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xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
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mutex_init(&ctx->uring_lock);
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init_waitqueue_head(&ctx->cq_wait);
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init_waitqueue_head(&ctx->poll_wq);
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init_waitqueue_head(&ctx->rsrc_quiesce_wq);
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spin_lock_init(&ctx->completion_lock);
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spin_lock_init(&ctx->timeout_lock);
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INIT_WQ_LIST(&ctx->iopoll_list);
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INIT_LIST_HEAD(&ctx->io_buffers_comp);
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INIT_LIST_HEAD(&ctx->defer_list);
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INIT_LIST_HEAD(&ctx->timeout_list);
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INIT_LIST_HEAD(&ctx->ltimeout_list);
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INIT_LIST_HEAD(&ctx->rsrc_ref_list);
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init_llist_head(&ctx->work_llist);
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INIT_LIST_HEAD(&ctx->tctx_list);
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ctx->submit_state.free_list.next = NULL;
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INIT_HLIST_HEAD(&ctx->waitid_list);
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#ifdef CONFIG_FUTEX
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INIT_HLIST_HEAD(&ctx->futex_list);
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#endif
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INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func);
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INIT_WQ_LIST(&ctx->submit_state.compl_reqs);
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INIT_HLIST_HEAD(&ctx->cancelable_uring_cmd);
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io_napi_init(ctx);
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return ctx;
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err:
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io_alloc_cache_free(&ctx->rsrc_node_cache, kfree);
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io_alloc_cache_free(&ctx->apoll_cache, kfree);
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io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free);
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io_alloc_cache_free(&ctx->rw_cache, io_rw_cache_free);
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io_alloc_cache_free(&ctx->uring_cache, kfree);
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io_alloc_cache_free(&ctx->msg_cache, io_msg_cache_free);
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io_futex_cache_free(ctx);
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kfree(ctx->cancel_table.hbs);
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|
kfree(ctx->cancel_table_locked.hbs);
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xa_destroy(&ctx->io_bl_xa);
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kfree(ctx);
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|
return NULL;
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|
}
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|
|
|
static void io_account_cq_overflow(struct io_ring_ctx *ctx)
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|
{
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|
struct io_rings *r = ctx->rings;
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|
|
|
WRITE_ONCE(r->cq_overflow, READ_ONCE(r->cq_overflow) + 1);
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|
ctx->cq_extra--;
|
|
}
|
|
|
|
static bool req_need_defer(struct io_kiocb *req, u32 seq)
|
|
{
|
|
if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
return seq + READ_ONCE(ctx->cq_extra) != ctx->cached_cq_tail;
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|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void io_clean_op(struct io_kiocb *req)
|
|
{
|
|
if (req->flags & REQ_F_BUFFER_SELECTED) {
|
|
spin_lock(&req->ctx->completion_lock);
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|
io_kbuf_drop(req);
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|
spin_unlock(&req->ctx->completion_lock);
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|
}
|
|
|
|
if (req->flags & REQ_F_NEED_CLEANUP) {
|
|
const struct io_cold_def *def = &io_cold_defs[req->opcode];
|
|
|
|
if (def->cleanup)
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|
def->cleanup(req);
|
|
}
|
|
if ((req->flags & REQ_F_POLLED) && req->apoll) {
|
|
kfree(req->apoll->double_poll);
|
|
kfree(req->apoll);
|
|
req->apoll = NULL;
|
|
}
|
|
if (req->flags & REQ_F_INFLIGHT) {
|
|
struct io_uring_task *tctx = req->task->io_uring;
|
|
|
|
atomic_dec(&tctx->inflight_tracked);
|
|
}
|
|
if (req->flags & REQ_F_CREDS)
|
|
put_cred(req->creds);
|
|
if (req->flags & REQ_F_ASYNC_DATA) {
|
|
kfree(req->async_data);
|
|
req->async_data = NULL;
|
|
}
|
|
req->flags &= ~IO_REQ_CLEAN_FLAGS;
|
|
}
|
|
|
|
static inline void io_req_track_inflight(struct io_kiocb *req)
|
|
{
|
|
if (!(req->flags & REQ_F_INFLIGHT)) {
|
|
req->flags |= REQ_F_INFLIGHT;
|
|
atomic_inc(&req->task->io_uring->inflight_tracked);
|
|
}
|
|
}
|
|
|
|
static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req)
|
|
{
|
|
if (WARN_ON_ONCE(!req->link))
|
|
return NULL;
|
|
|
|
req->flags &= ~REQ_F_ARM_LTIMEOUT;
|
|
req->flags |= REQ_F_LINK_TIMEOUT;
|
|
|
|
/* linked timeouts should have two refs once prep'ed */
|
|
io_req_set_refcount(req);
|
|
__io_req_set_refcount(req->link, 2);
|
|
return req->link;
|
|
}
|
|
|
|
static inline struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
|
|
{
|
|
if (likely(!(req->flags & REQ_F_ARM_LTIMEOUT)))
|
|
return NULL;
|
|
return __io_prep_linked_timeout(req);
|
|
}
|
|
|
|
static noinline void __io_arm_ltimeout(struct io_kiocb *req)
|
|
{
|
|
io_queue_linked_timeout(__io_prep_linked_timeout(req));
|
|
}
|
|
|
|
static inline void io_arm_ltimeout(struct io_kiocb *req)
|
|
{
|
|
if (unlikely(req->flags & REQ_F_ARM_LTIMEOUT))
|
|
__io_arm_ltimeout(req);
|
|
}
|
|
|
|
static void io_prep_async_work(struct io_kiocb *req)
|
|
{
|
|
const struct io_issue_def *def = &io_issue_defs[req->opcode];
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
if (!(req->flags & REQ_F_CREDS)) {
|
|
req->flags |= REQ_F_CREDS;
|
|
req->creds = get_current_cred();
|
|
}
|
|
|
|
req->work.list.next = NULL;
|
|
atomic_set(&req->work.flags, 0);
|
|
if (req->flags & REQ_F_FORCE_ASYNC)
|
|
atomic_or(IO_WQ_WORK_CONCURRENT, &req->work.flags);
|
|
|
|
if (req->file && !(req->flags & REQ_F_FIXED_FILE))
|
|
req->flags |= io_file_get_flags(req->file);
|
|
|
|
if (req->file && (req->flags & REQ_F_ISREG)) {
|
|
bool should_hash = def->hash_reg_file;
|
|
|
|
/* don't serialize this request if the fs doesn't need it */
|
|
if (should_hash && (req->file->f_flags & O_DIRECT) &&
|
|
(req->file->f_op->fop_flags & FOP_DIO_PARALLEL_WRITE))
|
|
should_hash = false;
|
|
if (should_hash || (ctx->flags & IORING_SETUP_IOPOLL))
|
|
io_wq_hash_work(&req->work, file_inode(req->file));
|
|
} else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) {
|
|
if (def->unbound_nonreg_file)
|
|
atomic_or(IO_WQ_WORK_UNBOUND, &req->work.flags);
|
|
}
|
|
}
|
|
|
|
static void io_prep_async_link(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *cur;
|
|
|
|
if (req->flags & REQ_F_LINK_TIMEOUT) {
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
spin_lock_irq(&ctx->timeout_lock);
|
|
io_for_each_link(cur, req)
|
|
io_prep_async_work(cur);
|
|
spin_unlock_irq(&ctx->timeout_lock);
|
|
} else {
|
|
io_for_each_link(cur, req)
|
|
io_prep_async_work(cur);
|
|
}
|
|
}
|
|
|
|
static void io_queue_iowq(struct io_kiocb *req)
|
|
{
|
|
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);
|
|
|
|
/* init ->work of the whole link before punting */
|
|
io_prep_async_link(req);
|
|
|
|
/*
|
|
* Not expected to happen, but if we do have a bug where this _can_
|
|
* happen, catch it here and ensure the request is marked as
|
|
* canceled. That will make io-wq go through the usual work cancel
|
|
* procedure rather than attempt to run this request (or create a new
|
|
* worker for it).
|
|
*/
|
|
if (WARN_ON_ONCE(!same_thread_group(req->task, current)))
|
|
atomic_or(IO_WQ_WORK_CANCEL, &req->work.flags);
|
|
|
|
trace_io_uring_queue_async_work(req, io_wq_is_hashed(&req->work));
|
|
io_wq_enqueue(tctx->io_wq, &req->work);
|
|
if (link)
|
|
io_queue_linked_timeout(link);
|
|
}
|
|
|
|
static __cold void io_queue_deferred(struct io_ring_ctx *ctx)
|
|
{
|
|
while (!list_empty(&ctx->defer_list)) {
|
|
struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
|
|
struct io_defer_entry, list);
|
|
|
|
if (req_need_defer(de->req, de->seq))
|
|
break;
|
|
list_del_init(&de->list);
|
|
io_req_task_queue(de->req);
|
|
kfree(de);
|
|
}
|
|
}
|
|
|
|
void __io_commit_cqring_flush(struct io_ring_ctx *ctx)
|
|
{
|
|
if (ctx->poll_activated)
|
|
io_poll_wq_wake(ctx);
|
|
if (ctx->off_timeout_used)
|
|
io_flush_timeouts(ctx);
|
|
if (ctx->drain_active) {
|
|
spin_lock(&ctx->completion_lock);
|
|
io_queue_deferred(ctx);
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
if (ctx->has_evfd)
|
|
io_eventfd_flush_signal(ctx);
|
|
}
|
|
|
|
static inline void __io_cq_lock(struct io_ring_ctx *ctx)
|
|
{
|
|
if (!ctx->lockless_cq)
|
|
spin_lock(&ctx->completion_lock);
|
|
}
|
|
|
|
static inline void io_cq_lock(struct io_ring_ctx *ctx)
|
|
__acquires(ctx->completion_lock)
|
|
{
|
|
spin_lock(&ctx->completion_lock);
|
|
}
|
|
|
|
static inline void __io_cq_unlock_post(struct io_ring_ctx *ctx)
|
|
{
|
|
io_commit_cqring(ctx);
|
|
if (!ctx->task_complete) {
|
|
if (!ctx->lockless_cq)
|
|
spin_unlock(&ctx->completion_lock);
|
|
/* IOPOLL rings only need to wake up if it's also SQPOLL */
|
|
if (!ctx->syscall_iopoll)
|
|
io_cqring_wake(ctx);
|
|
}
|
|
io_commit_cqring_flush(ctx);
|
|
}
|
|
|
|
static void io_cq_unlock_post(struct io_ring_ctx *ctx)
|
|
__releases(ctx->completion_lock)
|
|
{
|
|
io_commit_cqring(ctx);
|
|
spin_unlock(&ctx->completion_lock);
|
|
io_cqring_wake(ctx);
|
|
io_commit_cqring_flush(ctx);
|
|
}
|
|
|
|
static void __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool dying)
|
|
{
|
|
size_t cqe_size = sizeof(struct io_uring_cqe);
|
|
|
|
lockdep_assert_held(&ctx->uring_lock);
|
|
|
|
/* don't abort if we're dying, entries must get freed */
|
|
if (!dying && __io_cqring_events(ctx) == ctx->cq_entries)
|
|
return;
|
|
|
|
if (ctx->flags & IORING_SETUP_CQE32)
|
|
cqe_size <<= 1;
|
|
|
|
io_cq_lock(ctx);
|
|
while (!list_empty(&ctx->cq_overflow_list)) {
|
|
struct io_uring_cqe *cqe;
|
|
struct io_overflow_cqe *ocqe;
|
|
|
|
ocqe = list_first_entry(&ctx->cq_overflow_list,
|
|
struct io_overflow_cqe, list);
|
|
|
|
if (!dying) {
|
|
if (!io_get_cqe_overflow(ctx, &cqe, true))
|
|
break;
|
|
memcpy(cqe, &ocqe->cqe, cqe_size);
|
|
}
|
|
list_del(&ocqe->list);
|
|
kfree(ocqe);
|
|
}
|
|
|
|
if (list_empty(&ctx->cq_overflow_list)) {
|
|
clear_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq);
|
|
atomic_andnot(IORING_SQ_CQ_OVERFLOW, &ctx->rings->sq_flags);
|
|
}
|
|
io_cq_unlock_post(ctx);
|
|
}
|
|
|
|
static void io_cqring_overflow_kill(struct io_ring_ctx *ctx)
|
|
{
|
|
if (ctx->rings)
|
|
__io_cqring_overflow_flush(ctx, true);
|
|
}
|
|
|
|
static void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx)
|
|
{
|
|
mutex_lock(&ctx->uring_lock);
|
|
__io_cqring_overflow_flush(ctx, false);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
/* can be called by any task */
|
|
static void io_put_task_remote(struct task_struct *task)
|
|
{
|
|
struct io_uring_task *tctx = task->io_uring;
|
|
|
|
percpu_counter_sub(&tctx->inflight, 1);
|
|
if (unlikely(atomic_read(&tctx->in_cancel)))
|
|
wake_up(&tctx->wait);
|
|
put_task_struct(task);
|
|
}
|
|
|
|
/* used by a task to put its own references */
|
|
static void io_put_task_local(struct task_struct *task)
|
|
{
|
|
task->io_uring->cached_refs++;
|
|
}
|
|
|
|
/* must to be called somewhat shortly after putting a request */
|
|
static inline void io_put_task(struct task_struct *task)
|
|
{
|
|
if (likely(task == current))
|
|
io_put_task_local(task);
|
|
else
|
|
io_put_task_remote(task);
|
|
}
|
|
|
|
void io_task_refs_refill(struct io_uring_task *tctx)
|
|
{
|
|
unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;
|
|
|
|
percpu_counter_add(&tctx->inflight, refill);
|
|
refcount_add(refill, ¤t->usage);
|
|
tctx->cached_refs += refill;
|
|
}
|
|
|
|
static __cold void io_uring_drop_tctx_refs(struct task_struct *task)
|
|
{
|
|
struct io_uring_task *tctx = task->io_uring;
|
|
unsigned int refs = tctx->cached_refs;
|
|
|
|
if (refs) {
|
|
tctx->cached_refs = 0;
|
|
percpu_counter_sub(&tctx->inflight, refs);
|
|
put_task_struct_many(task, refs);
|
|
}
|
|
}
|
|
|
|
static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
|
|
s32 res, u32 cflags, u64 extra1, u64 extra2)
|
|
{
|
|
struct io_overflow_cqe *ocqe;
|
|
size_t ocq_size = sizeof(struct io_overflow_cqe);
|
|
bool is_cqe32 = (ctx->flags & IORING_SETUP_CQE32);
|
|
|
|
lockdep_assert_held(&ctx->completion_lock);
|
|
|
|
if (is_cqe32)
|
|
ocq_size += sizeof(struct io_uring_cqe);
|
|
|
|
ocqe = kmalloc(ocq_size, GFP_ATOMIC | __GFP_ACCOUNT);
|
|
trace_io_uring_cqe_overflow(ctx, user_data, res, cflags, ocqe);
|
|
if (!ocqe) {
|
|
/*
|
|
* If we're in ring overflow flush mode, or in task cancel mode,
|
|
* or cannot allocate an overflow entry, then we need to drop it
|
|
* on the floor.
|
|
*/
|
|
io_account_cq_overflow(ctx);
|
|
set_bit(IO_CHECK_CQ_DROPPED_BIT, &ctx->check_cq);
|
|
return false;
|
|
}
|
|
if (list_empty(&ctx->cq_overflow_list)) {
|
|
set_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq);
|
|
atomic_or(IORING_SQ_CQ_OVERFLOW, &ctx->rings->sq_flags);
|
|
|
|
}
|
|
ocqe->cqe.user_data = user_data;
|
|
ocqe->cqe.res = res;
|
|
ocqe->cqe.flags = cflags;
|
|
if (is_cqe32) {
|
|
ocqe->cqe.big_cqe[0] = extra1;
|
|
ocqe->cqe.big_cqe[1] = extra2;
|
|
}
|
|
list_add_tail(&ocqe->list, &ctx->cq_overflow_list);
|
|
return true;
|
|
}
|
|
|
|
static void io_req_cqe_overflow(struct io_kiocb *req)
|
|
{
|
|
io_cqring_event_overflow(req->ctx, req->cqe.user_data,
|
|
req->cqe.res, req->cqe.flags,
|
|
req->big_cqe.extra1, req->big_cqe.extra2);
|
|
memset(&req->big_cqe, 0, sizeof(req->big_cqe));
|
|
}
|
|
|
|
/*
|
|
* writes to the cq entry need to come after reading head; the
|
|
* control dependency is enough as we're using WRITE_ONCE to
|
|
* fill the cq entry
|
|
*/
|
|
bool io_cqe_cache_refill(struct io_ring_ctx *ctx, bool overflow)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
unsigned int off = ctx->cached_cq_tail & (ctx->cq_entries - 1);
|
|
unsigned int free, queued, len;
|
|
|
|
/*
|
|
* Posting into the CQ when there are pending overflowed CQEs may break
|
|
* ordering guarantees, which will affect links, F_MORE users and more.
|
|
* Force overflow the completion.
|
|
*/
|
|
if (!overflow && (ctx->check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT)))
|
|
return false;
|
|
|
|
/* userspace may cheat modifying the tail, be safe and do min */
|
|
queued = min(__io_cqring_events(ctx), ctx->cq_entries);
|
|
free = ctx->cq_entries - queued;
|
|
/* we need a contiguous range, limit based on the current array offset */
|
|
len = min(free, ctx->cq_entries - off);
|
|
if (!len)
|
|
return false;
|
|
|
|
if (ctx->flags & IORING_SETUP_CQE32) {
|
|
off <<= 1;
|
|
len <<= 1;
|
|
}
|
|
|
|
ctx->cqe_cached = &rings->cqes[off];
|
|
ctx->cqe_sentinel = ctx->cqe_cached + len;
|
|
return true;
|
|
}
|
|
|
|
static bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res,
|
|
u32 cflags)
|
|
{
|
|
struct io_uring_cqe *cqe;
|
|
|
|
ctx->cq_extra++;
|
|
|
|
/*
|
|
* If we can't get a cq entry, userspace overflowed the
|
|
* submission (by quite a lot). Increment the overflow count in
|
|
* the ring.
|
|
*/
|
|
if (likely(io_get_cqe(ctx, &cqe))) {
|
|
trace_io_uring_complete(ctx, NULL, user_data, res, cflags, 0, 0);
|
|
|
|
WRITE_ONCE(cqe->user_data, user_data);
|
|
WRITE_ONCE(cqe->res, res);
|
|
WRITE_ONCE(cqe->flags, cflags);
|
|
|
|
if (ctx->flags & IORING_SETUP_CQE32) {
|
|
WRITE_ONCE(cqe->big_cqe[0], 0);
|
|
WRITE_ONCE(cqe->big_cqe[1], 0);
|
|
}
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static bool __io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res,
|
|
u32 cflags)
|
|
{
|
|
bool filled;
|
|
|
|
filled = io_fill_cqe_aux(ctx, user_data, res, cflags);
|
|
if (!filled)
|
|
filled = io_cqring_event_overflow(ctx, user_data, res, cflags, 0, 0);
|
|
|
|
return filled;
|
|
}
|
|
|
|
bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags)
|
|
{
|
|
bool filled;
|
|
|
|
io_cq_lock(ctx);
|
|
filled = __io_post_aux_cqe(ctx, user_data, res, cflags);
|
|
io_cq_unlock_post(ctx);
|
|
return filled;
|
|
}
|
|
|
|
/*
|
|
* Must be called from inline task_work so we now a flush will happen later,
|
|
* and obviously with ctx->uring_lock held (tw always has that).
|
|
*/
|
|
void io_add_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags)
|
|
{
|
|
if (!io_fill_cqe_aux(ctx, user_data, res, cflags)) {
|
|
spin_lock(&ctx->completion_lock);
|
|
io_cqring_event_overflow(ctx, user_data, res, cflags, 0, 0);
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
ctx->submit_state.cq_flush = true;
|
|
}
|
|
|
|
/*
|
|
* A helper for multishot requests posting additional CQEs.
|
|
* Should only be used from a task_work including IO_URING_F_MULTISHOT.
|
|
*/
|
|
bool io_req_post_cqe(struct io_kiocb *req, s32 res, u32 cflags)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
bool posted;
|
|
|
|
lockdep_assert(!io_wq_current_is_worker());
|
|
lockdep_assert_held(&ctx->uring_lock);
|
|
|
|
__io_cq_lock(ctx);
|
|
posted = io_fill_cqe_aux(ctx, req->cqe.user_data, res, cflags);
|
|
ctx->submit_state.cq_flush = true;
|
|
__io_cq_unlock_post(ctx);
|
|
return posted;
|
|
}
|
|
|
|
static void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
/*
|
|
* All execution paths but io-wq use the deferred completions by
|
|
* passing IO_URING_F_COMPLETE_DEFER and thus should not end up here.
|
|
*/
|
|
if (WARN_ON_ONCE(!(issue_flags & IO_URING_F_IOWQ)))
|
|
return;
|
|
|
|
/*
|
|
* Handle special CQ sync cases via task_work. DEFER_TASKRUN requires
|
|
* the submitter task context, IOPOLL protects with uring_lock.
|
|
*/
|
|
if (ctx->task_complete || (ctx->flags & IORING_SETUP_IOPOLL)) {
|
|
req->io_task_work.func = io_req_task_complete;
|
|
io_req_task_work_add(req);
|
|
return;
|
|
}
|
|
|
|
io_cq_lock(ctx);
|
|
if (!(req->flags & REQ_F_CQE_SKIP)) {
|
|
if (!io_fill_cqe_req(ctx, req))
|
|
io_req_cqe_overflow(req);
|
|
}
|
|
io_cq_unlock_post(ctx);
|
|
|
|
/*
|
|
* We don't free the request here because we know it's called from
|
|
* io-wq only, which holds a reference, so it cannot be the last put.
|
|
*/
|
|
req_ref_put(req);
|
|
}
|
|
|
|
void io_req_defer_failed(struct io_kiocb *req, s32 res)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
const struct io_cold_def *def = &io_cold_defs[req->opcode];
|
|
|
|
lockdep_assert_held(&req->ctx->uring_lock);
|
|
|
|
req_set_fail(req);
|
|
io_req_set_res(req, res, io_put_kbuf(req, IO_URING_F_UNLOCKED));
|
|
if (def->fail)
|
|
def->fail(req);
|
|
io_req_complete_defer(req);
|
|
}
|
|
|
|
/*
|
|
* Don't initialise the fields below on every allocation, but do that in
|
|
* advance and keep them valid across allocations.
|
|
*/
|
|
static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
|
|
{
|
|
req->ctx = ctx;
|
|
req->link = NULL;
|
|
req->async_data = NULL;
|
|
/* not necessary, but safer to zero */
|
|
memset(&req->cqe, 0, sizeof(req->cqe));
|
|
memset(&req->big_cqe, 0, sizeof(req->big_cqe));
|
|
}
|
|
|
|
/*
|
|
* A request might get retired back into the request caches even before opcode
|
|
* handlers and io_issue_sqe() are done with it, e.g. inline completion path.
|
|
* Because of that, io_alloc_req() should be called only under ->uring_lock
|
|
* and with extra caution to not get a request that is still worked on.
|
|
*/
|
|
__cold bool __io_alloc_req_refill(struct io_ring_ctx *ctx)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
|
|
void *reqs[IO_REQ_ALLOC_BATCH];
|
|
int ret;
|
|
|
|
ret = kmem_cache_alloc_bulk(req_cachep, gfp, ARRAY_SIZE(reqs), reqs);
|
|
|
|
/*
|
|
* Bulk alloc is all-or-nothing. If we fail to get a batch,
|
|
* retry single alloc to be on the safe side.
|
|
*/
|
|
if (unlikely(ret <= 0)) {
|
|
reqs[0] = kmem_cache_alloc(req_cachep, gfp);
|
|
if (!reqs[0])
|
|
return false;
|
|
ret = 1;
|
|
}
|
|
|
|
percpu_ref_get_many(&ctx->refs, ret);
|
|
while (ret--) {
|
|
struct io_kiocb *req = reqs[ret];
|
|
|
|
io_preinit_req(req, ctx);
|
|
io_req_add_to_cache(req, ctx);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
__cold void io_free_req(struct io_kiocb *req)
|
|
{
|
|
/* refs were already put, restore them for io_req_task_complete() */
|
|
req->flags &= ~REQ_F_REFCOUNT;
|
|
/* we only want to free it, don't post CQEs */
|
|
req->flags |= REQ_F_CQE_SKIP;
|
|
req->io_task_work.func = io_req_task_complete;
|
|
io_req_task_work_add(req);
|
|
}
|
|
|
|
static void __io_req_find_next_prep(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
io_disarm_next(req);
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
|
|
static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt;
|
|
|
|
/*
|
|
* If LINK is set, we have dependent requests in this chain. If we
|
|
* didn't fail this request, queue the first one up, moving any other
|
|
* dependencies to the next request. In case of failure, fail the rest
|
|
* of the chain.
|
|
*/
|
|
if (unlikely(req->flags & IO_DISARM_MASK))
|
|
__io_req_find_next_prep(req);
|
|
nxt = req->link;
|
|
req->link = NULL;
|
|
return nxt;
|
|
}
|
|
|
|
static void ctx_flush_and_put(struct io_ring_ctx *ctx, struct io_tw_state *ts)
|
|
{
|
|
if (!ctx)
|
|
return;
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
|
|
atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
|
|
|
|
io_submit_flush_completions(ctx);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
percpu_ref_put(&ctx->refs);
|
|
}
|
|
|
|
/*
|
|
* Run queued task_work, returning the number of entries processed in *count.
|
|
* If more entries than max_entries are available, stop processing once this
|
|
* is reached and return the rest of the list.
|
|
*/
|
|
struct llist_node *io_handle_tw_list(struct llist_node *node,
|
|
unsigned int *count,
|
|
unsigned int max_entries)
|
|
{
|
|
struct io_ring_ctx *ctx = NULL;
|
|
struct io_tw_state ts = { };
|
|
|
|
do {
|
|
struct llist_node *next = node->next;
|
|
struct io_kiocb *req = container_of(node, struct io_kiocb,
|
|
io_task_work.node);
|
|
|
|
if (req->ctx != ctx) {
|
|
ctx_flush_and_put(ctx, &ts);
|
|
ctx = req->ctx;
|
|
mutex_lock(&ctx->uring_lock);
|
|
percpu_ref_get(&ctx->refs);
|
|
}
|
|
INDIRECT_CALL_2(req->io_task_work.func,
|
|
io_poll_task_func, io_req_rw_complete,
|
|
req, &ts);
|
|
node = next;
|
|
(*count)++;
|
|
if (unlikely(need_resched())) {
|
|
ctx_flush_and_put(ctx, &ts);
|
|
ctx = NULL;
|
|
cond_resched();
|
|
}
|
|
} while (node && *count < max_entries);
|
|
|
|
ctx_flush_and_put(ctx, &ts);
|
|
return node;
|
|
}
|
|
|
|
/**
|
|
* io_llist_xchg - swap all entries in a lock-less list
|
|
* @head: the head of lock-less list to delete all entries
|
|
* @new: new entry as the head of the list
|
|
*
|
|
* If list is empty, return NULL, otherwise, return the pointer to the first entry.
|
|
* The order of entries returned is from the newest to the oldest added one.
|
|
*/
|
|
static inline struct llist_node *io_llist_xchg(struct llist_head *head,
|
|
struct llist_node *new)
|
|
{
|
|
return xchg(&head->first, new);
|
|
}
|
|
|
|
static __cold void io_fallback_tw(struct io_uring_task *tctx, bool sync)
|
|
{
|
|
struct llist_node *node = llist_del_all(&tctx->task_list);
|
|
struct io_ring_ctx *last_ctx = NULL;
|
|
struct io_kiocb *req;
|
|
|
|
while (node) {
|
|
req = container_of(node, struct io_kiocb, io_task_work.node);
|
|
node = node->next;
|
|
if (sync && last_ctx != req->ctx) {
|
|
if (last_ctx) {
|
|
flush_delayed_work(&last_ctx->fallback_work);
|
|
percpu_ref_put(&last_ctx->refs);
|
|
}
|
|
last_ctx = req->ctx;
|
|
percpu_ref_get(&last_ctx->refs);
|
|
}
|
|
if (llist_add(&req->io_task_work.node,
|
|
&req->ctx->fallback_llist))
|
|
schedule_delayed_work(&req->ctx->fallback_work, 1);
|
|
}
|
|
|
|
if (last_ctx) {
|
|
flush_delayed_work(&last_ctx->fallback_work);
|
|
percpu_ref_put(&last_ctx->refs);
|
|
}
|
|
}
|
|
|
|
struct llist_node *tctx_task_work_run(struct io_uring_task *tctx,
|
|
unsigned int max_entries,
|
|
unsigned int *count)
|
|
{
|
|
struct llist_node *node;
|
|
|
|
if (unlikely(current->flags & PF_EXITING)) {
|
|
io_fallback_tw(tctx, true);
|
|
return NULL;
|
|
}
|
|
|
|
node = llist_del_all(&tctx->task_list);
|
|
if (node) {
|
|
node = llist_reverse_order(node);
|
|
node = io_handle_tw_list(node, count, max_entries);
|
|
}
|
|
|
|
/* relaxed read is enough as only the task itself sets ->in_cancel */
|
|
if (unlikely(atomic_read(&tctx->in_cancel)))
|
|
io_uring_drop_tctx_refs(current);
|
|
|
|
trace_io_uring_task_work_run(tctx, *count);
|
|
return node;
|
|
}
|
|
|
|
void tctx_task_work(struct callback_head *cb)
|
|
{
|
|
struct io_uring_task *tctx;
|
|
struct llist_node *ret;
|
|
unsigned int count = 0;
|
|
|
|
tctx = container_of(cb, struct io_uring_task, task_work);
|
|
ret = tctx_task_work_run(tctx, UINT_MAX, &count);
|
|
/* can't happen */
|
|
WARN_ON_ONCE(ret);
|
|
}
|
|
|
|
static inline void io_req_local_work_add(struct io_kiocb *req,
|
|
struct io_ring_ctx *ctx,
|
|
unsigned flags)
|
|
{
|
|
unsigned nr_wait, nr_tw, nr_tw_prev;
|
|
struct llist_node *head;
|
|
|
|
/* See comment above IO_CQ_WAKE_INIT */
|
|
BUILD_BUG_ON(IO_CQ_WAKE_FORCE <= IORING_MAX_CQ_ENTRIES);
|
|
|
|
/*
|
|
* We don't know how many reuqests is there in the link and whether
|
|
* they can even be queued lazily, fall back to non-lazy.
|
|
*/
|
|
if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK))
|
|
flags &= ~IOU_F_TWQ_LAZY_WAKE;
|
|
|
|
guard(rcu)();
|
|
|
|
head = READ_ONCE(ctx->work_llist.first);
|
|
do {
|
|
nr_tw_prev = 0;
|
|
if (head) {
|
|
struct io_kiocb *first_req = container_of(head,
|
|
struct io_kiocb,
|
|
io_task_work.node);
|
|
/*
|
|
* Might be executed at any moment, rely on
|
|
* SLAB_TYPESAFE_BY_RCU to keep it alive.
|
|
*/
|
|
nr_tw_prev = READ_ONCE(first_req->nr_tw);
|
|
}
|
|
|
|
/*
|
|
* Theoretically, it can overflow, but that's fine as one of
|
|
* previous adds should've tried to wake the task.
|
|
*/
|
|
nr_tw = nr_tw_prev + 1;
|
|
if (!(flags & IOU_F_TWQ_LAZY_WAKE))
|
|
nr_tw = IO_CQ_WAKE_FORCE;
|
|
|
|
req->nr_tw = nr_tw;
|
|
req->io_task_work.node.next = head;
|
|
} while (!try_cmpxchg(&ctx->work_llist.first, &head,
|
|
&req->io_task_work.node));
|
|
|
|
/*
|
|
* cmpxchg implies a full barrier, which pairs with the barrier
|
|
* in set_current_state() on the io_cqring_wait() side. It's used
|
|
* to ensure that either we see updated ->cq_wait_nr, or waiters
|
|
* going to sleep will observe the work added to the list, which
|
|
* is similar to the wait/wawke task state sync.
|
|
*/
|
|
|
|
if (!head) {
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
|
|
atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
|
|
if (ctx->has_evfd)
|
|
io_eventfd_signal(ctx);
|
|
}
|
|
|
|
nr_wait = atomic_read(&ctx->cq_wait_nr);
|
|
/* not enough or no one is waiting */
|
|
if (nr_tw < nr_wait)
|
|
return;
|
|
/* the previous add has already woken it up */
|
|
if (nr_tw_prev >= nr_wait)
|
|
return;
|
|
wake_up_state(ctx->submitter_task, TASK_INTERRUPTIBLE);
|
|
}
|
|
|
|
static void io_req_normal_work_add(struct io_kiocb *req)
|
|
{
|
|
struct io_uring_task *tctx = req->task->io_uring;
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
|
|
/* task_work already pending, we're done */
|
|
if (!llist_add(&req->io_task_work.node, &tctx->task_list))
|
|
return;
|
|
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
|
|
atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
|
|
|
|
/* SQPOLL doesn't need the task_work added, it'll run it itself */
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
struct io_sq_data *sqd = ctx->sq_data;
|
|
|
|
if (sqd->thread)
|
|
__set_notify_signal(sqd->thread);
|
|
return;
|
|
}
|
|
|
|
if (likely(!task_work_add(req->task, &tctx->task_work, ctx->notify_method)))
|
|
return;
|
|
|
|
io_fallback_tw(tctx, false);
|
|
}
|
|
|
|
void __io_req_task_work_add(struct io_kiocb *req, unsigned flags)
|
|
{
|
|
if (req->ctx->flags & IORING_SETUP_DEFER_TASKRUN)
|
|
io_req_local_work_add(req, req->ctx, flags);
|
|
else
|
|
io_req_normal_work_add(req);
|
|
}
|
|
|
|
void io_req_task_work_add_remote(struct io_kiocb *req, struct io_ring_ctx *ctx,
|
|
unsigned flags)
|
|
{
|
|
if (WARN_ON_ONCE(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)))
|
|
return;
|
|
io_req_local_work_add(req, ctx, flags);
|
|
}
|
|
|
|
static void __cold io_move_task_work_from_local(struct io_ring_ctx *ctx)
|
|
{
|
|
struct llist_node *node;
|
|
|
|
node = llist_del_all(&ctx->work_llist);
|
|
while (node) {
|
|
struct io_kiocb *req = container_of(node, struct io_kiocb,
|
|
io_task_work.node);
|
|
|
|
node = node->next;
|
|
io_req_normal_work_add(req);
|
|
}
|
|
}
|
|
|
|
static bool io_run_local_work_continue(struct io_ring_ctx *ctx, int events,
|
|
int min_events)
|
|
{
|
|
if (llist_empty(&ctx->work_llist))
|
|
return false;
|
|
if (events < min_events)
|
|
return true;
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
|
|
atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
|
|
return false;
|
|
}
|
|
|
|
static int __io_run_local_work(struct io_ring_ctx *ctx, struct io_tw_state *ts,
|
|
int min_events)
|
|
{
|
|
struct llist_node *node;
|
|
unsigned int loops = 0;
|
|
int ret = 0;
|
|
|
|
if (WARN_ON_ONCE(ctx->submitter_task != current))
|
|
return -EEXIST;
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG)
|
|
atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags);
|
|
again:
|
|
/*
|
|
* llists are in reverse order, flip it back the right way before
|
|
* running the pending items.
|
|
*/
|
|
node = llist_reverse_order(io_llist_xchg(&ctx->work_llist, NULL));
|
|
while (node) {
|
|
struct llist_node *next = node->next;
|
|
struct io_kiocb *req = container_of(node, struct io_kiocb,
|
|
io_task_work.node);
|
|
INDIRECT_CALL_2(req->io_task_work.func,
|
|
io_poll_task_func, io_req_rw_complete,
|
|
req, ts);
|
|
ret++;
|
|
node = next;
|
|
}
|
|
loops++;
|
|
|
|
if (io_run_local_work_continue(ctx, ret, min_events))
|
|
goto again;
|
|
io_submit_flush_completions(ctx);
|
|
if (io_run_local_work_continue(ctx, ret, min_events))
|
|
goto again;
|
|
|
|
trace_io_uring_local_work_run(ctx, ret, loops);
|
|
return ret;
|
|
}
|
|
|
|
static inline int io_run_local_work_locked(struct io_ring_ctx *ctx,
|
|
int min_events)
|
|
{
|
|
struct io_tw_state ts = {};
|
|
|
|
if (llist_empty(&ctx->work_llist))
|
|
return 0;
|
|
return __io_run_local_work(ctx, &ts, min_events);
|
|
}
|
|
|
|
static int io_run_local_work(struct io_ring_ctx *ctx, int min_events)
|
|
{
|
|
struct io_tw_state ts = {};
|
|
int ret;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
ret = __io_run_local_work(ctx, &ts, min_events);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
return ret;
|
|
}
|
|
|
|
static void io_req_task_cancel(struct io_kiocb *req, struct io_tw_state *ts)
|
|
{
|
|
io_tw_lock(req->ctx, ts);
|
|
io_req_defer_failed(req, req->cqe.res);
|
|
}
|
|
|
|
void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts)
|
|
{
|
|
io_tw_lock(req->ctx, ts);
|
|
/* req->task == current here, checking PF_EXITING is safe */
|
|
if (unlikely(req->task->flags & PF_EXITING))
|
|
io_req_defer_failed(req, -EFAULT);
|
|
else if (req->flags & REQ_F_FORCE_ASYNC)
|
|
io_queue_iowq(req);
|
|
else
|
|
io_queue_sqe(req);
|
|
}
|
|
|
|
void io_req_task_queue_fail(struct io_kiocb *req, int ret)
|
|
{
|
|
io_req_set_res(req, ret, 0);
|
|
req->io_task_work.func = io_req_task_cancel;
|
|
io_req_task_work_add(req);
|
|
}
|
|
|
|
void io_req_task_queue(struct io_kiocb *req)
|
|
{
|
|
req->io_task_work.func = io_req_task_submit;
|
|
io_req_task_work_add(req);
|
|
}
|
|
|
|
void io_queue_next(struct io_kiocb *req)
|
|
{
|
|
struct io_kiocb *nxt = io_req_find_next(req);
|
|
|
|
if (nxt)
|
|
io_req_task_queue(nxt);
|
|
}
|
|
|
|
static void io_free_batch_list(struct io_ring_ctx *ctx,
|
|
struct io_wq_work_node *node)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
do {
|
|
struct io_kiocb *req = container_of(node, struct io_kiocb,
|
|
comp_list);
|
|
|
|
if (unlikely(req->flags & IO_REQ_CLEAN_SLOW_FLAGS)) {
|
|
if (req->flags & REQ_F_REFCOUNT) {
|
|
node = req->comp_list.next;
|
|
if (!req_ref_put_and_test(req))
|
|
continue;
|
|
}
|
|
if ((req->flags & REQ_F_POLLED) && req->apoll) {
|
|
struct async_poll *apoll = req->apoll;
|
|
|
|
if (apoll->double_poll)
|
|
kfree(apoll->double_poll);
|
|
if (!io_alloc_cache_put(&ctx->apoll_cache, apoll))
|
|
kfree(apoll);
|
|
req->flags &= ~REQ_F_POLLED;
|
|
}
|
|
if (req->flags & IO_REQ_LINK_FLAGS)
|
|
io_queue_next(req);
|
|
if (unlikely(req->flags & IO_REQ_CLEAN_FLAGS))
|
|
io_clean_op(req);
|
|
}
|
|
io_put_file(req);
|
|
io_put_rsrc_node(ctx, req->rsrc_node);
|
|
io_put_task(req->task);
|
|
|
|
node = req->comp_list.next;
|
|
io_req_add_to_cache(req, ctx);
|
|
} while (node);
|
|
}
|
|
|
|
void __io_submit_flush_completions(struct io_ring_ctx *ctx)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
struct io_submit_state *state = &ctx->submit_state;
|
|
struct io_wq_work_node *node;
|
|
|
|
__io_cq_lock(ctx);
|
|
__wq_list_for_each(node, &state->compl_reqs) {
|
|
struct io_kiocb *req = container_of(node, struct io_kiocb,
|
|
comp_list);
|
|
|
|
if (!(req->flags & REQ_F_CQE_SKIP) &&
|
|
unlikely(!io_fill_cqe_req(ctx, req))) {
|
|
if (ctx->lockless_cq) {
|
|
spin_lock(&ctx->completion_lock);
|
|
io_req_cqe_overflow(req);
|
|
spin_unlock(&ctx->completion_lock);
|
|
} else {
|
|
io_req_cqe_overflow(req);
|
|
}
|
|
}
|
|
}
|
|
__io_cq_unlock_post(ctx);
|
|
|
|
if (!wq_list_empty(&state->compl_reqs)) {
|
|
io_free_batch_list(ctx, state->compl_reqs.first);
|
|
INIT_WQ_LIST(&state->compl_reqs);
|
|
}
|
|
ctx->submit_state.cq_flush = false;
|
|
}
|
|
|
|
static unsigned io_cqring_events(struct io_ring_ctx *ctx)
|
|
{
|
|
/* See comment at the top of this file */
|
|
smp_rmb();
|
|
return __io_cqring_events(ctx);
|
|
}
|
|
|
|
/*
|
|
* We can't just wait for polled events to come to us, we have to actively
|
|
* find and complete them.
|
|
*/
|
|
static __cold void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
|
|
{
|
|
if (!(ctx->flags & IORING_SETUP_IOPOLL))
|
|
return;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
while (!wq_list_empty(&ctx->iopoll_list)) {
|
|
/* let it sleep and repeat later if can't complete a request */
|
|
if (io_do_iopoll(ctx, true) == 0)
|
|
break;
|
|
/*
|
|
* Ensure we allow local-to-the-cpu processing to take place,
|
|
* in this case we need to ensure that we reap all events.
|
|
* Also let task_work, etc. to progress by releasing the mutex
|
|
*/
|
|
if (need_resched()) {
|
|
mutex_unlock(&ctx->uring_lock);
|
|
cond_resched();
|
|
mutex_lock(&ctx->uring_lock);
|
|
}
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
|
|
{
|
|
unsigned int nr_events = 0;
|
|
unsigned long check_cq;
|
|
|
|
lockdep_assert_held(&ctx->uring_lock);
|
|
|
|
if (!io_allowed_run_tw(ctx))
|
|
return -EEXIST;
|
|
|
|
check_cq = READ_ONCE(ctx->check_cq);
|
|
if (unlikely(check_cq)) {
|
|
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
|
|
__io_cqring_overflow_flush(ctx, false);
|
|
/*
|
|
* Similarly do not spin if we have not informed the user of any
|
|
* dropped CQE.
|
|
*/
|
|
if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT))
|
|
return -EBADR;
|
|
}
|
|
/*
|
|
* Don't enter poll loop if we already have events pending.
|
|
* If we do, we can potentially be spinning for commands that
|
|
* already triggered a CQE (eg in error).
|
|
*/
|
|
if (io_cqring_events(ctx))
|
|
return 0;
|
|
|
|
do {
|
|
int ret = 0;
|
|
|
|
/*
|
|
* If a submit got punted to a workqueue, we can have the
|
|
* application entering polling for a command before it gets
|
|
* issued. That app will hold the uring_lock for the duration
|
|
* of the poll right here, so we need to take a breather every
|
|
* now and then to ensure that the issue has a chance to add
|
|
* the poll to the issued list. Otherwise we can spin here
|
|
* forever, while the workqueue is stuck trying to acquire the
|
|
* very same mutex.
|
|
*/
|
|
if (wq_list_empty(&ctx->iopoll_list) ||
|
|
io_task_work_pending(ctx)) {
|
|
u32 tail = ctx->cached_cq_tail;
|
|
|
|
(void) io_run_local_work_locked(ctx, min);
|
|
|
|
if (task_work_pending(current) ||
|
|
wq_list_empty(&ctx->iopoll_list)) {
|
|
mutex_unlock(&ctx->uring_lock);
|
|
io_run_task_work();
|
|
mutex_lock(&ctx->uring_lock);
|
|
}
|
|
/* some requests don't go through iopoll_list */
|
|
if (tail != ctx->cached_cq_tail ||
|
|
wq_list_empty(&ctx->iopoll_list))
|
|
break;
|
|
}
|
|
ret = io_do_iopoll(ctx, !min);
|
|
if (unlikely(ret < 0))
|
|
return ret;
|
|
|
|
if (task_sigpending(current))
|
|
return -EINTR;
|
|
if (need_resched())
|
|
break;
|
|
|
|
nr_events += ret;
|
|
} while (nr_events < min);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts)
|
|
{
|
|
io_req_complete_defer(req);
|
|
}
|
|
|
|
/*
|
|
* After the iocb has been issued, it's safe to be found on the poll list.
|
|
* Adding the kiocb to the list AFTER submission ensures that we don't
|
|
* find it from a io_do_iopoll() thread before the issuer is done
|
|
* accessing the kiocb cookie.
|
|
*/
|
|
static void io_iopoll_req_issued(struct io_kiocb *req, unsigned int issue_flags)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
const bool needs_lock = issue_flags & IO_URING_F_UNLOCKED;
|
|
|
|
/* workqueue context doesn't hold uring_lock, grab it now */
|
|
if (unlikely(needs_lock))
|
|
mutex_lock(&ctx->uring_lock);
|
|
|
|
/*
|
|
* Track whether we have multiple files in our lists. This will impact
|
|
* how we do polling eventually, not spinning if we're on potentially
|
|
* different devices.
|
|
*/
|
|
if (wq_list_empty(&ctx->iopoll_list)) {
|
|
ctx->poll_multi_queue = false;
|
|
} else if (!ctx->poll_multi_queue) {
|
|
struct io_kiocb *list_req;
|
|
|
|
list_req = container_of(ctx->iopoll_list.first, struct io_kiocb,
|
|
comp_list);
|
|
if (list_req->file != req->file)
|
|
ctx->poll_multi_queue = true;
|
|
}
|
|
|
|
/*
|
|
* For fast devices, IO may have already completed. If it has, add
|
|
* it to the front so we find it first.
|
|
*/
|
|
if (READ_ONCE(req->iopoll_completed))
|
|
wq_list_add_head(&req->comp_list, &ctx->iopoll_list);
|
|
else
|
|
wq_list_add_tail(&req->comp_list, &ctx->iopoll_list);
|
|
|
|
if (unlikely(needs_lock)) {
|
|
/*
|
|
* If IORING_SETUP_SQPOLL is enabled, sqes are either handle
|
|
* in sq thread task context or in io worker task context. If
|
|
* current task context is sq thread, we don't need to check
|
|
* whether should wake up sq thread.
|
|
*/
|
|
if ((ctx->flags & IORING_SETUP_SQPOLL) &&
|
|
wq_has_sleeper(&ctx->sq_data->wait))
|
|
wake_up(&ctx->sq_data->wait);
|
|
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
}
|
|
|
|
io_req_flags_t io_file_get_flags(struct file *file)
|
|
{
|
|
io_req_flags_t res = 0;
|
|
|
|
if (S_ISREG(file_inode(file)->i_mode))
|
|
res |= REQ_F_ISREG;
|
|
if ((file->f_flags & O_NONBLOCK) || (file->f_mode & FMODE_NOWAIT))
|
|
res |= REQ_F_SUPPORT_NOWAIT;
|
|
return res;
|
|
}
|
|
|
|
bool io_alloc_async_data(struct io_kiocb *req)
|
|
{
|
|
const struct io_issue_def *def = &io_issue_defs[req->opcode];
|
|
|
|
WARN_ON_ONCE(!def->async_size);
|
|
req->async_data = kmalloc(def->async_size, GFP_KERNEL);
|
|
if (req->async_data) {
|
|
req->flags |= REQ_F_ASYNC_DATA;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static u32 io_get_sequence(struct io_kiocb *req)
|
|
{
|
|
u32 seq = req->ctx->cached_sq_head;
|
|
struct io_kiocb *cur;
|
|
|
|
/* need original cached_sq_head, but it was increased for each req */
|
|
io_for_each_link(cur, req)
|
|
seq--;
|
|
return seq;
|
|
}
|
|
|
|
static __cold void io_drain_req(struct io_kiocb *req)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_defer_entry *de;
|
|
int ret;
|
|
u32 seq = io_get_sequence(req);
|
|
|
|
/* Still need defer if there is pending req in defer list. */
|
|
spin_lock(&ctx->completion_lock);
|
|
if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) {
|
|
spin_unlock(&ctx->completion_lock);
|
|
queue:
|
|
ctx->drain_active = false;
|
|
io_req_task_queue(req);
|
|
return;
|
|
}
|
|
spin_unlock(&ctx->completion_lock);
|
|
|
|
io_prep_async_link(req);
|
|
de = kmalloc(sizeof(*de), GFP_KERNEL);
|
|
if (!de) {
|
|
ret = -ENOMEM;
|
|
io_req_defer_failed(req, ret);
|
|
return;
|
|
}
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
|
|
spin_unlock(&ctx->completion_lock);
|
|
kfree(de);
|
|
goto queue;
|
|
}
|
|
|
|
trace_io_uring_defer(req);
|
|
de->req = req;
|
|
de->seq = seq;
|
|
list_add_tail(&de->list, &ctx->defer_list);
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
|
|
static bool io_assign_file(struct io_kiocb *req, const struct io_issue_def *def,
|
|
unsigned int issue_flags)
|
|
{
|
|
if (req->file || !def->needs_file)
|
|
return true;
|
|
|
|
if (req->flags & REQ_F_FIXED_FILE)
|
|
req->file = io_file_get_fixed(req, req->cqe.fd, issue_flags);
|
|
else
|
|
req->file = io_file_get_normal(req, req->cqe.fd);
|
|
|
|
return !!req->file;
|
|
}
|
|
|
|
static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
|
|
{
|
|
const struct io_issue_def *def = &io_issue_defs[req->opcode];
|
|
const struct cred *creds = NULL;
|
|
int ret;
|
|
|
|
if (unlikely(!io_assign_file(req, def, issue_flags)))
|
|
return -EBADF;
|
|
|
|
if (unlikely((req->flags & REQ_F_CREDS) && req->creds != current_cred()))
|
|
creds = override_creds(req->creds);
|
|
|
|
if (!def->audit_skip)
|
|
audit_uring_entry(req->opcode);
|
|
|
|
ret = def->issue(req, issue_flags);
|
|
|
|
if (!def->audit_skip)
|
|
audit_uring_exit(!ret, ret);
|
|
|
|
if (creds)
|
|
revert_creds(creds);
|
|
|
|
if (ret == IOU_OK) {
|
|
if (issue_flags & IO_URING_F_COMPLETE_DEFER)
|
|
io_req_complete_defer(req);
|
|
else
|
|
io_req_complete_post(req, issue_flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
if (ret == IOU_ISSUE_SKIP_COMPLETE) {
|
|
ret = 0;
|
|
io_arm_ltimeout(req);
|
|
|
|
/* If the op doesn't have a file, we're not polling for it */
|
|
if ((req->ctx->flags & IORING_SETUP_IOPOLL) && def->iopoll_queue)
|
|
io_iopoll_req_issued(req, issue_flags);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts)
|
|
{
|
|
io_tw_lock(req->ctx, ts);
|
|
return io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_MULTISHOT|
|
|
IO_URING_F_COMPLETE_DEFER);
|
|
}
|
|
|
|
struct io_wq_work *io_wq_free_work(struct io_wq_work *work)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
struct io_kiocb *nxt = NULL;
|
|
|
|
if (req_ref_put_and_test(req)) {
|
|
if (req->flags & IO_REQ_LINK_FLAGS)
|
|
nxt = io_req_find_next(req);
|
|
io_free_req(req);
|
|
}
|
|
return nxt ? &nxt->work : NULL;
|
|
}
|
|
|
|
void io_wq_submit_work(struct io_wq_work *work)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
const struct io_issue_def *def = &io_issue_defs[req->opcode];
|
|
unsigned int issue_flags = IO_URING_F_UNLOCKED | IO_URING_F_IOWQ;
|
|
bool needs_poll = false;
|
|
int ret = 0, err = -ECANCELED;
|
|
|
|
/* one will be dropped by ->io_wq_free_work() after returning to io-wq */
|
|
if (!(req->flags & REQ_F_REFCOUNT))
|
|
__io_req_set_refcount(req, 2);
|
|
else
|
|
req_ref_get(req);
|
|
|
|
io_arm_ltimeout(req);
|
|
|
|
/* either cancelled or io-wq is dying, so don't touch tctx->iowq */
|
|
if (atomic_read(&work->flags) & IO_WQ_WORK_CANCEL) {
|
|
fail:
|
|
io_req_task_queue_fail(req, err);
|
|
return;
|
|
}
|
|
if (!io_assign_file(req, def, issue_flags)) {
|
|
err = -EBADF;
|
|
atomic_or(IO_WQ_WORK_CANCEL, &work->flags);
|
|
goto fail;
|
|
}
|
|
|
|
/*
|
|
* If DEFER_TASKRUN is set, it's only allowed to post CQEs from the
|
|
* submitter task context. Final request completions are handed to the
|
|
* right context, however this is not the case of auxiliary CQEs,
|
|
* which is the main mean of operation for multishot requests.
|
|
* Don't allow any multishot execution from io-wq. It's more restrictive
|
|
* than necessary and also cleaner.
|
|
*/
|
|
if (req->flags & REQ_F_APOLL_MULTISHOT) {
|
|
err = -EBADFD;
|
|
if (!io_file_can_poll(req))
|
|
goto fail;
|
|
if (req->file->f_flags & O_NONBLOCK ||
|
|
req->file->f_mode & FMODE_NOWAIT) {
|
|
err = -ECANCELED;
|
|
if (io_arm_poll_handler(req, issue_flags) != IO_APOLL_OK)
|
|
goto fail;
|
|
return;
|
|
} else {
|
|
req->flags &= ~REQ_F_APOLL_MULTISHOT;
|
|
}
|
|
}
|
|
|
|
if (req->flags & REQ_F_FORCE_ASYNC) {
|
|
bool opcode_poll = def->pollin || def->pollout;
|
|
|
|
if (opcode_poll && io_file_can_poll(req)) {
|
|
needs_poll = true;
|
|
issue_flags |= IO_URING_F_NONBLOCK;
|
|
}
|
|
}
|
|
|
|
do {
|
|
ret = io_issue_sqe(req, issue_flags);
|
|
if (ret != -EAGAIN)
|
|
break;
|
|
|
|
/*
|
|
* If REQ_F_NOWAIT is set, then don't wait or retry with
|
|
* poll. -EAGAIN is final for that case.
|
|
*/
|
|
if (req->flags & REQ_F_NOWAIT)
|
|
break;
|
|
|
|
/*
|
|
* We can get EAGAIN for iopolled IO even though we're
|
|
* forcing a sync submission from here, since we can't
|
|
* wait for request slots on the block side.
|
|
*/
|
|
if (!needs_poll) {
|
|
if (!(req->ctx->flags & IORING_SETUP_IOPOLL))
|
|
break;
|
|
if (io_wq_worker_stopped())
|
|
break;
|
|
cond_resched();
|
|
continue;
|
|
}
|
|
|
|
if (io_arm_poll_handler(req, issue_flags) == IO_APOLL_OK)
|
|
return;
|
|
/* aborted or ready, in either case retry blocking */
|
|
needs_poll = false;
|
|
issue_flags &= ~IO_URING_F_NONBLOCK;
|
|
} while (1);
|
|
|
|
/* avoid locking problems by failing it from a clean context */
|
|
if (ret)
|
|
io_req_task_queue_fail(req, ret);
|
|
}
|
|
|
|
inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
|
|
unsigned int issue_flags)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_fixed_file *slot;
|
|
struct file *file = NULL;
|
|
|
|
io_ring_submit_lock(ctx, issue_flags);
|
|
|
|
if (unlikely((unsigned int)fd >= ctx->nr_user_files))
|
|
goto out;
|
|
fd = array_index_nospec(fd, ctx->nr_user_files);
|
|
slot = io_fixed_file_slot(&ctx->file_table, fd);
|
|
if (!req->rsrc_node)
|
|
__io_req_set_rsrc_node(req, ctx);
|
|
req->flags |= io_slot_flags(slot);
|
|
file = io_slot_file(slot);
|
|
out:
|
|
io_ring_submit_unlock(ctx, issue_flags);
|
|
return file;
|
|
}
|
|
|
|
struct file *io_file_get_normal(struct io_kiocb *req, int fd)
|
|
{
|
|
struct file *file = fget(fd);
|
|
|
|
trace_io_uring_file_get(req, fd);
|
|
|
|
/* we don't allow fixed io_uring files */
|
|
if (file && io_is_uring_fops(file))
|
|
io_req_track_inflight(req);
|
|
return file;
|
|
}
|
|
|
|
static void io_queue_async(struct io_kiocb *req, int ret)
|
|
__must_hold(&req->ctx->uring_lock)
|
|
{
|
|
struct io_kiocb *linked_timeout;
|
|
|
|
if (ret != -EAGAIN || (req->flags & REQ_F_NOWAIT)) {
|
|
io_req_defer_failed(req, ret);
|
|
return;
|
|
}
|
|
|
|
linked_timeout = io_prep_linked_timeout(req);
|
|
|
|
switch (io_arm_poll_handler(req, 0)) {
|
|
case IO_APOLL_READY:
|
|
io_kbuf_recycle(req, 0);
|
|
io_req_task_queue(req);
|
|
break;
|
|
case IO_APOLL_ABORTED:
|
|
io_kbuf_recycle(req, 0);
|
|
io_queue_iowq(req);
|
|
break;
|
|
case IO_APOLL_OK:
|
|
break;
|
|
}
|
|
|
|
if (linked_timeout)
|
|
io_queue_linked_timeout(linked_timeout);
|
|
}
|
|
|
|
static inline void io_queue_sqe(struct io_kiocb *req)
|
|
__must_hold(&req->ctx->uring_lock)
|
|
{
|
|
int ret;
|
|
|
|
ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER);
|
|
|
|
/*
|
|
* We async punt it if the file wasn't marked NOWAIT, or if the file
|
|
* doesn't support non-blocking read/write attempts
|
|
*/
|
|
if (unlikely(ret))
|
|
io_queue_async(req, ret);
|
|
}
|
|
|
|
static void io_queue_sqe_fallback(struct io_kiocb *req)
|
|
__must_hold(&req->ctx->uring_lock)
|
|
{
|
|
if (unlikely(req->flags & REQ_F_FAIL)) {
|
|
/*
|
|
* We don't submit, fail them all, for that replace hardlinks
|
|
* with normal links. Extra REQ_F_LINK is tolerated.
|
|
*/
|
|
req->flags &= ~REQ_F_HARDLINK;
|
|
req->flags |= REQ_F_LINK;
|
|
io_req_defer_failed(req, req->cqe.res);
|
|
} else {
|
|
if (unlikely(req->ctx->drain_active))
|
|
io_drain_req(req);
|
|
else
|
|
io_queue_iowq(req);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Check SQE restrictions (opcode and flags).
|
|
*
|
|
* Returns 'true' if SQE is allowed, 'false' otherwise.
|
|
*/
|
|
static inline bool io_check_restriction(struct io_ring_ctx *ctx,
|
|
struct io_kiocb *req,
|
|
unsigned int sqe_flags)
|
|
{
|
|
if (!test_bit(req->opcode, ctx->restrictions.sqe_op))
|
|
return false;
|
|
|
|
if ((sqe_flags & ctx->restrictions.sqe_flags_required) !=
|
|
ctx->restrictions.sqe_flags_required)
|
|
return false;
|
|
|
|
if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed |
|
|
ctx->restrictions.sqe_flags_required))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
static void io_init_req_drain(struct io_kiocb *req)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_kiocb *head = ctx->submit_state.link.head;
|
|
|
|
ctx->drain_active = true;
|
|
if (head) {
|
|
/*
|
|
* If we need to drain a request in the middle of a link, drain
|
|
* the head request and the next request/link after the current
|
|
* link. Considering sequential execution of links,
|
|
* REQ_F_IO_DRAIN will be maintained for every request of our
|
|
* link.
|
|
*/
|
|
head->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC;
|
|
ctx->drain_next = true;
|
|
}
|
|
}
|
|
|
|
static __cold int io_init_fail_req(struct io_kiocb *req, int err)
|
|
{
|
|
/* ensure per-opcode data is cleared if we fail before prep */
|
|
memset(&req->cmd.data, 0, sizeof(req->cmd.data));
|
|
return err;
|
|
}
|
|
|
|
static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
const struct io_issue_def *def;
|
|
unsigned int sqe_flags;
|
|
int personality;
|
|
u8 opcode;
|
|
|
|
/* req is partially pre-initialised, see io_preinit_req() */
|
|
req->opcode = opcode = READ_ONCE(sqe->opcode);
|
|
/* same numerical values with corresponding REQ_F_*, safe to copy */
|
|
sqe_flags = READ_ONCE(sqe->flags);
|
|
req->flags = (io_req_flags_t) sqe_flags;
|
|
req->cqe.user_data = READ_ONCE(sqe->user_data);
|
|
req->file = NULL;
|
|
req->rsrc_node = NULL;
|
|
req->task = current;
|
|
req->cancel_seq_set = false;
|
|
|
|
if (unlikely(opcode >= IORING_OP_LAST)) {
|
|
req->opcode = 0;
|
|
return io_init_fail_req(req, -EINVAL);
|
|
}
|
|
def = &io_issue_defs[opcode];
|
|
if (unlikely(sqe_flags & ~SQE_COMMON_FLAGS)) {
|
|
/* enforce forwards compatibility on users */
|
|
if (sqe_flags & ~SQE_VALID_FLAGS)
|
|
return io_init_fail_req(req, -EINVAL);
|
|
if (sqe_flags & IOSQE_BUFFER_SELECT) {
|
|
if (!def->buffer_select)
|
|
return io_init_fail_req(req, -EOPNOTSUPP);
|
|
req->buf_index = READ_ONCE(sqe->buf_group);
|
|
}
|
|
if (sqe_flags & IOSQE_CQE_SKIP_SUCCESS)
|
|
ctx->drain_disabled = true;
|
|
if (sqe_flags & IOSQE_IO_DRAIN) {
|
|
if (ctx->drain_disabled)
|
|
return io_init_fail_req(req, -EOPNOTSUPP);
|
|
io_init_req_drain(req);
|
|
}
|
|
}
|
|
if (unlikely(ctx->restricted || ctx->drain_active || ctx->drain_next)) {
|
|
if (ctx->restricted && !io_check_restriction(ctx, req, sqe_flags))
|
|
return io_init_fail_req(req, -EACCES);
|
|
/* knock it to the slow queue path, will be drained there */
|
|
if (ctx->drain_active)
|
|
req->flags |= REQ_F_FORCE_ASYNC;
|
|
/* if there is no link, we're at "next" request and need to drain */
|
|
if (unlikely(ctx->drain_next) && !ctx->submit_state.link.head) {
|
|
ctx->drain_next = false;
|
|
ctx->drain_active = true;
|
|
req->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC;
|
|
}
|
|
}
|
|
|
|
if (!def->ioprio && sqe->ioprio)
|
|
return io_init_fail_req(req, -EINVAL);
|
|
if (!def->iopoll && (ctx->flags & IORING_SETUP_IOPOLL))
|
|
return io_init_fail_req(req, -EINVAL);
|
|
|
|
if (def->needs_file) {
|
|
struct io_submit_state *state = &ctx->submit_state;
|
|
|
|
req->cqe.fd = READ_ONCE(sqe->fd);
|
|
|
|
/*
|
|
* Plug now if we have more than 2 IO left after this, and the
|
|
* target is potentially a read/write to block based storage.
|
|
*/
|
|
if (state->need_plug && def->plug) {
|
|
state->plug_started = true;
|
|
state->need_plug = false;
|
|
blk_start_plug_nr_ios(&state->plug, state->submit_nr);
|
|
}
|
|
}
|
|
|
|
personality = READ_ONCE(sqe->personality);
|
|
if (personality) {
|
|
int ret;
|
|
|
|
req->creds = xa_load(&ctx->personalities, personality);
|
|
if (!req->creds)
|
|
return io_init_fail_req(req, -EINVAL);
|
|
get_cred(req->creds);
|
|
ret = security_uring_override_creds(req->creds);
|
|
if (ret) {
|
|
put_cred(req->creds);
|
|
return io_init_fail_req(req, ret);
|
|
}
|
|
req->flags |= REQ_F_CREDS;
|
|
}
|
|
|
|
return def->prep(req, sqe);
|
|
}
|
|
|
|
static __cold int io_submit_fail_init(const struct io_uring_sqe *sqe,
|
|
struct io_kiocb *req, int ret)
|
|
{
|
|
struct io_ring_ctx *ctx = req->ctx;
|
|
struct io_submit_link *link = &ctx->submit_state.link;
|
|
struct io_kiocb *head = link->head;
|
|
|
|
trace_io_uring_req_failed(sqe, req, ret);
|
|
|
|
/*
|
|
* Avoid breaking links in the middle as it renders links with SQPOLL
|
|
* unusable. Instead of failing eagerly, continue assembling the link if
|
|
* applicable and mark the head with REQ_F_FAIL. The link flushing code
|
|
* should find the flag and handle the rest.
|
|
*/
|
|
req_fail_link_node(req, ret);
|
|
if (head && !(head->flags & REQ_F_FAIL))
|
|
req_fail_link_node(head, -ECANCELED);
|
|
|
|
if (!(req->flags & IO_REQ_LINK_FLAGS)) {
|
|
if (head) {
|
|
link->last->link = req;
|
|
link->head = NULL;
|
|
req = head;
|
|
}
|
|
io_queue_sqe_fallback(req);
|
|
return ret;
|
|
}
|
|
|
|
if (head)
|
|
link->last->link = req;
|
|
else
|
|
link->head = req;
|
|
link->last = req;
|
|
return 0;
|
|
}
|
|
|
|
static inline int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
|
|
const struct io_uring_sqe *sqe)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
struct io_submit_link *link = &ctx->submit_state.link;
|
|
int ret;
|
|
|
|
ret = io_init_req(ctx, req, sqe);
|
|
if (unlikely(ret))
|
|
return io_submit_fail_init(sqe, req, ret);
|
|
|
|
trace_io_uring_submit_req(req);
|
|
|
|
/*
|
|
* If we already have a head request, queue this one for async
|
|
* submittal once the head completes. If we don't have a head but
|
|
* IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
|
|
* submitted sync once the chain is complete. If none of those
|
|
* conditions are true (normal request), then just queue it.
|
|
*/
|
|
if (unlikely(link->head)) {
|
|
trace_io_uring_link(req, link->head);
|
|
link->last->link = req;
|
|
link->last = req;
|
|
|
|
if (req->flags & IO_REQ_LINK_FLAGS)
|
|
return 0;
|
|
/* last request of the link, flush it */
|
|
req = link->head;
|
|
link->head = NULL;
|
|
if (req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL))
|
|
goto fallback;
|
|
|
|
} else if (unlikely(req->flags & (IO_REQ_LINK_FLAGS |
|
|
REQ_F_FORCE_ASYNC | REQ_F_FAIL))) {
|
|
if (req->flags & IO_REQ_LINK_FLAGS) {
|
|
link->head = req;
|
|
link->last = req;
|
|
} else {
|
|
fallback:
|
|
io_queue_sqe_fallback(req);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
io_queue_sqe(req);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Batched submission is done, ensure local IO is flushed out.
|
|
*/
|
|
static void io_submit_state_end(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_submit_state *state = &ctx->submit_state;
|
|
|
|
if (unlikely(state->link.head))
|
|
io_queue_sqe_fallback(state->link.head);
|
|
/* flush only after queuing links as they can generate completions */
|
|
io_submit_flush_completions(ctx);
|
|
if (state->plug_started)
|
|
blk_finish_plug(&state->plug);
|
|
}
|
|
|
|
/*
|
|
* Start submission side cache.
|
|
*/
|
|
static void io_submit_state_start(struct io_submit_state *state,
|
|
unsigned int max_ios)
|
|
{
|
|
state->plug_started = false;
|
|
state->need_plug = max_ios > 2;
|
|
state->submit_nr = max_ios;
|
|
/* set only head, no need to init link_last in advance */
|
|
state->link.head = NULL;
|
|
}
|
|
|
|
static void io_commit_sqring(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_rings *rings = ctx->rings;
|
|
|
|
/*
|
|
* Ensure any loads from the SQEs are done at this point,
|
|
* since once we write the new head, the application could
|
|
* write new data to them.
|
|
*/
|
|
smp_store_release(&rings->sq.head, ctx->cached_sq_head);
|
|
}
|
|
|
|
/*
|
|
* Fetch an sqe, if one is available. Note this returns a pointer to memory
|
|
* that is mapped by userspace. This means that care needs to be taken to
|
|
* ensure that reads are stable, as we cannot rely on userspace always
|
|
* being a good citizen. If members of the sqe are validated and then later
|
|
* used, it's important that those reads are done through READ_ONCE() to
|
|
* prevent a re-load down the line.
|
|
*/
|
|
static bool io_get_sqe(struct io_ring_ctx *ctx, const struct io_uring_sqe **sqe)
|
|
{
|
|
unsigned mask = ctx->sq_entries - 1;
|
|
unsigned head = ctx->cached_sq_head++ & mask;
|
|
|
|
if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) {
|
|
head = READ_ONCE(ctx->sq_array[head]);
|
|
if (unlikely(head >= ctx->sq_entries)) {
|
|
/* drop invalid entries */
|
|
spin_lock(&ctx->completion_lock);
|
|
ctx->cq_extra--;
|
|
spin_unlock(&ctx->completion_lock);
|
|
WRITE_ONCE(ctx->rings->sq_dropped,
|
|
READ_ONCE(ctx->rings->sq_dropped) + 1);
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The cached sq head (or cq tail) serves two purposes:
|
|
*
|
|
* 1) allows us to batch the cost of updating the user visible
|
|
* head updates.
|
|
* 2) allows the kernel side to track the head on its own, even
|
|
* though the application is the one updating it.
|
|
*/
|
|
|
|
/* double index for 128-byte SQEs, twice as long */
|
|
if (ctx->flags & IORING_SETUP_SQE128)
|
|
head <<= 1;
|
|
*sqe = &ctx->sq_sqes[head];
|
|
return true;
|
|
}
|
|
|
|
int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
|
|
__must_hold(&ctx->uring_lock)
|
|
{
|
|
unsigned int entries = io_sqring_entries(ctx);
|
|
unsigned int left;
|
|
int ret;
|
|
|
|
if (unlikely(!entries))
|
|
return 0;
|
|
/* make sure SQ entry isn't read before tail */
|
|
ret = left = min(nr, entries);
|
|
io_get_task_refs(left);
|
|
io_submit_state_start(&ctx->submit_state, left);
|
|
|
|
do {
|
|
const struct io_uring_sqe *sqe;
|
|
struct io_kiocb *req;
|
|
|
|
if (unlikely(!io_alloc_req(ctx, &req)))
|
|
break;
|
|
if (unlikely(!io_get_sqe(ctx, &sqe))) {
|
|
io_req_add_to_cache(req, ctx);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Continue submitting even for sqe failure if the
|
|
* ring was setup with IORING_SETUP_SUBMIT_ALL
|
|
*/
|
|
if (unlikely(io_submit_sqe(ctx, req, sqe)) &&
|
|
!(ctx->flags & IORING_SETUP_SUBMIT_ALL)) {
|
|
left--;
|
|
break;
|
|
}
|
|
} while (--left);
|
|
|
|
if (unlikely(left)) {
|
|
ret -= left;
|
|
/* try again if it submitted nothing and can't allocate a req */
|
|
if (!ret && io_req_cache_empty(ctx))
|
|
ret = -EAGAIN;
|
|
current->io_uring->cached_refs += left;
|
|
}
|
|
|
|
io_submit_state_end(ctx);
|
|
/* Commit SQ ring head once we've consumed and submitted all SQEs */
|
|
io_commit_sqring(ctx);
|
|
return ret;
|
|
}
|
|
|
|
static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
|
|
int wake_flags, void *key)
|
|
{
|
|
struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, wq);
|
|
|
|
/*
|
|
* Cannot safely flush overflowed CQEs from here, ensure we wake up
|
|
* the task, and the next invocation will do it.
|
|
*/
|
|
if (io_should_wake(iowq) || io_has_work(iowq->ctx))
|
|
return autoremove_wake_function(curr, mode, wake_flags, key);
|
|
return -1;
|
|
}
|
|
|
|
int io_run_task_work_sig(struct io_ring_ctx *ctx)
|
|
{
|
|
if (!llist_empty(&ctx->work_llist)) {
|
|
__set_current_state(TASK_RUNNING);
|
|
if (io_run_local_work(ctx, INT_MAX) > 0)
|
|
return 0;
|
|
}
|
|
if (io_run_task_work() > 0)
|
|
return 0;
|
|
if (task_sigpending(current))
|
|
return -EINTR;
|
|
return 0;
|
|
}
|
|
|
|
static bool current_pending_io(void)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
|
|
if (!tctx)
|
|
return false;
|
|
return percpu_counter_read_positive(&tctx->inflight);
|
|
}
|
|
|
|
/* when returns >0, the caller should retry */
|
|
static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
|
|
struct io_wait_queue *iowq)
|
|
{
|
|
int ret;
|
|
|
|
if (unlikely(READ_ONCE(ctx->check_cq)))
|
|
return 1;
|
|
if (unlikely(!llist_empty(&ctx->work_llist)))
|
|
return 1;
|
|
if (unlikely(test_thread_flag(TIF_NOTIFY_SIGNAL)))
|
|
return 1;
|
|
if (unlikely(task_sigpending(current)))
|
|
return -EINTR;
|
|
if (unlikely(io_should_wake(iowq)))
|
|
return 0;
|
|
|
|
/*
|
|
* Mark us as being in io_wait if we have pending requests, so cpufreq
|
|
* can take into account that the task is waiting for IO - turns out
|
|
* to be important for low QD IO.
|
|
*/
|
|
if (current_pending_io())
|
|
current->in_iowait = 1;
|
|
ret = 0;
|
|
if (iowq->timeout == KTIME_MAX)
|
|
schedule();
|
|
else if (!schedule_hrtimeout(&iowq->timeout, HRTIMER_MODE_ABS))
|
|
ret = -ETIME;
|
|
current->in_iowait = 0;
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Wait until events become available, if we don't already have some. The
|
|
* application must reap them itself, as they reside on the shared cq ring.
|
|
*/
|
|
static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
|
|
const sigset_t __user *sig, size_t sigsz,
|
|
struct __kernel_timespec __user *uts)
|
|
{
|
|
struct io_wait_queue iowq;
|
|
struct io_rings *rings = ctx->rings;
|
|
int ret;
|
|
|
|
if (!io_allowed_run_tw(ctx))
|
|
return -EEXIST;
|
|
if (!llist_empty(&ctx->work_llist))
|
|
io_run_local_work(ctx, min_events);
|
|
io_run_task_work();
|
|
|
|
if (unlikely(test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)))
|
|
io_cqring_do_overflow_flush(ctx);
|
|
if (__io_cqring_events_user(ctx) >= min_events)
|
|
return 0;
|
|
|
|
init_waitqueue_func_entry(&iowq.wq, io_wake_function);
|
|
iowq.wq.private = current;
|
|
INIT_LIST_HEAD(&iowq.wq.entry);
|
|
iowq.ctx = ctx;
|
|
iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
|
|
iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events;
|
|
iowq.timeout = KTIME_MAX;
|
|
|
|
if (uts) {
|
|
struct timespec64 ts;
|
|
ktime_t dt;
|
|
|
|
if (get_timespec64(&ts, uts))
|
|
return -EFAULT;
|
|
|
|
dt = timespec64_to_ktime(ts);
|
|
iowq.timeout = ktime_add(dt, ktime_get());
|
|
io_napi_adjust_timeout(ctx, &iowq, dt);
|
|
}
|
|
|
|
if (sig) {
|
|
#ifdef CONFIG_COMPAT
|
|
if (in_compat_syscall())
|
|
ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
|
|
sigsz);
|
|
else
|
|
#endif
|
|
ret = set_user_sigmask(sig, sigsz);
|
|
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
io_napi_busy_loop(ctx, &iowq);
|
|
|
|
trace_io_uring_cqring_wait(ctx, min_events);
|
|
do {
|
|
int nr_wait = (int) iowq.cq_tail - READ_ONCE(ctx->rings->cq.tail);
|
|
unsigned long check_cq;
|
|
|
|
if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
|
|
atomic_set(&ctx->cq_wait_nr, nr_wait);
|
|
set_current_state(TASK_INTERRUPTIBLE);
|
|
} else {
|
|
prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq,
|
|
TASK_INTERRUPTIBLE);
|
|
}
|
|
|
|
ret = io_cqring_wait_schedule(ctx, &iowq);
|
|
__set_current_state(TASK_RUNNING);
|
|
atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT);
|
|
|
|
/*
|
|
* Run task_work after scheduling and before io_should_wake().
|
|
* If we got woken because of task_work being processed, run it
|
|
* now rather than let the caller do another wait loop.
|
|
*/
|
|
io_run_task_work();
|
|
if (!llist_empty(&ctx->work_llist))
|
|
io_run_local_work(ctx, nr_wait);
|
|
|
|
/*
|
|
* Non-local task_work will be run on exit to userspace, but
|
|
* if we're using DEFER_TASKRUN, then we could have waited
|
|
* with a timeout for a number of requests. If the timeout
|
|
* hits, we could have some requests ready to process. Ensure
|
|
* this break is _after_ we have run task_work, to avoid
|
|
* deferring running potentially pending requests until the
|
|
* next time we wait for events.
|
|
*/
|
|
if (ret < 0)
|
|
break;
|
|
|
|
check_cq = READ_ONCE(ctx->check_cq);
|
|
if (unlikely(check_cq)) {
|
|
/* let the caller flush overflows, retry */
|
|
if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
|
|
io_cqring_do_overflow_flush(ctx);
|
|
if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) {
|
|
ret = -EBADR;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (io_should_wake(&iowq)) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
cond_resched();
|
|
} while (1);
|
|
|
|
if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN))
|
|
finish_wait(&ctx->cq_wait, &iowq.wq);
|
|
restore_saved_sigmask_unless(ret == -EINTR);
|
|
|
|
return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
|
|
}
|
|
|
|
static void *io_rings_map(struct io_ring_ctx *ctx, unsigned long uaddr,
|
|
size_t size)
|
|
{
|
|
return __io_uaddr_map(&ctx->ring_pages, &ctx->n_ring_pages, uaddr,
|
|
size);
|
|
}
|
|
|
|
static void *io_sqes_map(struct io_ring_ctx *ctx, unsigned long uaddr,
|
|
size_t size)
|
|
{
|
|
return __io_uaddr_map(&ctx->sqe_pages, &ctx->n_sqe_pages, uaddr,
|
|
size);
|
|
}
|
|
|
|
static void io_rings_free(struct io_ring_ctx *ctx)
|
|
{
|
|
if (!(ctx->flags & IORING_SETUP_NO_MMAP)) {
|
|
io_pages_unmap(ctx->rings, &ctx->ring_pages, &ctx->n_ring_pages,
|
|
true);
|
|
io_pages_unmap(ctx->sq_sqes, &ctx->sqe_pages, &ctx->n_sqe_pages,
|
|
true);
|
|
} else {
|
|
io_pages_free(&ctx->ring_pages, ctx->n_ring_pages);
|
|
ctx->n_ring_pages = 0;
|
|
io_pages_free(&ctx->sqe_pages, ctx->n_sqe_pages);
|
|
ctx->n_sqe_pages = 0;
|
|
vunmap(ctx->rings);
|
|
vunmap(ctx->sq_sqes);
|
|
}
|
|
|
|
ctx->rings = NULL;
|
|
ctx->sq_sqes = NULL;
|
|
}
|
|
|
|
static unsigned long rings_size(struct io_ring_ctx *ctx, unsigned int sq_entries,
|
|
unsigned int cq_entries, size_t *sq_offset)
|
|
{
|
|
struct io_rings *rings;
|
|
size_t off, sq_array_size;
|
|
|
|
off = struct_size(rings, cqes, cq_entries);
|
|
if (off == SIZE_MAX)
|
|
return SIZE_MAX;
|
|
if (ctx->flags & IORING_SETUP_CQE32) {
|
|
if (check_shl_overflow(off, 1, &off))
|
|
return SIZE_MAX;
|
|
}
|
|
|
|
#ifdef CONFIG_SMP
|
|
off = ALIGN(off, SMP_CACHE_BYTES);
|
|
if (off == 0)
|
|
return SIZE_MAX;
|
|
#endif
|
|
|
|
if (ctx->flags & IORING_SETUP_NO_SQARRAY) {
|
|
*sq_offset = SIZE_MAX;
|
|
return off;
|
|
}
|
|
|
|
*sq_offset = off;
|
|
|
|
sq_array_size = array_size(sizeof(u32), sq_entries);
|
|
if (sq_array_size == SIZE_MAX)
|
|
return SIZE_MAX;
|
|
|
|
if (check_add_overflow(off, sq_array_size, &off))
|
|
return SIZE_MAX;
|
|
|
|
return off;
|
|
}
|
|
|
|
static void io_req_caches_free(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_kiocb *req;
|
|
int nr = 0;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
|
|
while (!io_req_cache_empty(ctx)) {
|
|
req = io_extract_req(ctx);
|
|
kmem_cache_free(req_cachep, req);
|
|
nr++;
|
|
}
|
|
if (nr)
|
|
percpu_ref_put_many(&ctx->refs, nr);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
|
|
{
|
|
io_sq_thread_finish(ctx);
|
|
/* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */
|
|
if (WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list)))
|
|
return;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
if (ctx->buf_data)
|
|
__io_sqe_buffers_unregister(ctx);
|
|
if (ctx->file_data)
|
|
__io_sqe_files_unregister(ctx);
|
|
io_cqring_overflow_kill(ctx);
|
|
io_eventfd_unregister(ctx);
|
|
io_alloc_cache_free(&ctx->apoll_cache, kfree);
|
|
io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free);
|
|
io_alloc_cache_free(&ctx->rw_cache, io_rw_cache_free);
|
|
io_alloc_cache_free(&ctx->uring_cache, kfree);
|
|
io_alloc_cache_free(&ctx->msg_cache, io_msg_cache_free);
|
|
io_futex_cache_free(ctx);
|
|
io_destroy_buffers(ctx);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
if (ctx->sq_creds)
|
|
put_cred(ctx->sq_creds);
|
|
if (ctx->submitter_task)
|
|
put_task_struct(ctx->submitter_task);
|
|
|
|
/* there are no registered resources left, nobody uses it */
|
|
if (ctx->rsrc_node)
|
|
io_rsrc_node_destroy(ctx, ctx->rsrc_node);
|
|
|
|
WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
|
|
WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
|
|
|
|
io_alloc_cache_free(&ctx->rsrc_node_cache, kfree);
|
|
if (ctx->mm_account) {
|
|
mmdrop(ctx->mm_account);
|
|
ctx->mm_account = NULL;
|
|
}
|
|
io_rings_free(ctx);
|
|
|
|
percpu_ref_exit(&ctx->refs);
|
|
free_uid(ctx->user);
|
|
io_req_caches_free(ctx);
|
|
if (ctx->hash_map)
|
|
io_wq_put_hash(ctx->hash_map);
|
|
io_napi_free(ctx);
|
|
kfree(ctx->cancel_table.hbs);
|
|
kfree(ctx->cancel_table_locked.hbs);
|
|
xa_destroy(&ctx->io_bl_xa);
|
|
kfree(ctx);
|
|
}
|
|
|
|
static __cold void io_activate_pollwq_cb(struct callback_head *cb)
|
|
{
|
|
struct io_ring_ctx *ctx = container_of(cb, struct io_ring_ctx,
|
|
poll_wq_task_work);
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
ctx->poll_activated = true;
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
/*
|
|
* Wake ups for some events between start of polling and activation
|
|
* might've been lost due to loose synchronisation.
|
|
*/
|
|
wake_up_all(&ctx->poll_wq);
|
|
percpu_ref_put(&ctx->refs);
|
|
}
|
|
|
|
__cold void io_activate_pollwq(struct io_ring_ctx *ctx)
|
|
{
|
|
spin_lock(&ctx->completion_lock);
|
|
/* already activated or in progress */
|
|
if (ctx->poll_activated || ctx->poll_wq_task_work.func)
|
|
goto out;
|
|
if (WARN_ON_ONCE(!ctx->task_complete))
|
|
goto out;
|
|
if (!ctx->submitter_task)
|
|
goto out;
|
|
/*
|
|
* with ->submitter_task only the submitter task completes requests, we
|
|
* only need to sync with it, which is done by injecting a tw
|
|
*/
|
|
init_task_work(&ctx->poll_wq_task_work, io_activate_pollwq_cb);
|
|
percpu_ref_get(&ctx->refs);
|
|
if (task_work_add(ctx->submitter_task, &ctx->poll_wq_task_work, TWA_SIGNAL))
|
|
percpu_ref_put(&ctx->refs);
|
|
out:
|
|
spin_unlock(&ctx->completion_lock);
|
|
}
|
|
|
|
static __poll_t io_uring_poll(struct file *file, poll_table *wait)
|
|
{
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
__poll_t mask = 0;
|
|
|
|
if (unlikely(!ctx->poll_activated))
|
|
io_activate_pollwq(ctx);
|
|
|
|
poll_wait(file, &ctx->poll_wq, wait);
|
|
/*
|
|
* synchronizes with barrier from wq_has_sleeper call in
|
|
* io_commit_cqring
|
|
*/
|
|
smp_rmb();
|
|
if (!io_sqring_full(ctx))
|
|
mask |= EPOLLOUT | EPOLLWRNORM;
|
|
|
|
/*
|
|
* Don't flush cqring overflow list here, just do a simple check.
|
|
* Otherwise there could possible be ABBA deadlock:
|
|
* CPU0 CPU1
|
|
* ---- ----
|
|
* lock(&ctx->uring_lock);
|
|
* lock(&ep->mtx);
|
|
* lock(&ctx->uring_lock);
|
|
* lock(&ep->mtx);
|
|
*
|
|
* Users may get EPOLLIN meanwhile seeing nothing in cqring, this
|
|
* pushes them to do the flush.
|
|
*/
|
|
|
|
if (__io_cqring_events_user(ctx) || io_has_work(ctx))
|
|
mask |= EPOLLIN | EPOLLRDNORM;
|
|
|
|
return mask;
|
|
}
|
|
|
|
struct io_tctx_exit {
|
|
struct callback_head task_work;
|
|
struct completion completion;
|
|
struct io_ring_ctx *ctx;
|
|
};
|
|
|
|
static __cold void io_tctx_exit_cb(struct callback_head *cb)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
struct io_tctx_exit *work;
|
|
|
|
work = container_of(cb, struct io_tctx_exit, task_work);
|
|
/*
|
|
* When @in_cancel, we're in cancellation and it's racy to remove the
|
|
* node. It'll be removed by the end of cancellation, just ignore it.
|
|
* tctx can be NULL if the queueing of this task_work raced with
|
|
* work cancelation off the exec path.
|
|
*/
|
|
if (tctx && !atomic_read(&tctx->in_cancel))
|
|
io_uring_del_tctx_node((unsigned long)work->ctx);
|
|
complete(&work->completion);
|
|
}
|
|
|
|
static __cold 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 __cold void io_ring_exit_work(struct work_struct *work)
|
|
{
|
|
struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work);
|
|
unsigned long timeout = jiffies + HZ * 60 * 5;
|
|
unsigned long interval = HZ / 20;
|
|
struct io_tctx_exit exit;
|
|
struct io_tctx_node *node;
|
|
int ret;
|
|
|
|
/*
|
|
* If we're doing polled IO and end up having requests being
|
|
* submitted async (out-of-line), then completions can come in while
|
|
* we're waiting for refs to drop. We need to reap these manually,
|
|
* as nobody else will be looking for them.
|
|
*/
|
|
do {
|
|
if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)) {
|
|
mutex_lock(&ctx->uring_lock);
|
|
io_cqring_overflow_kill(ctx);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
if (ctx->flags & IORING_SETUP_DEFER_TASKRUN)
|
|
io_move_task_work_from_local(ctx);
|
|
|
|
while (io_uring_try_cancel_requests(ctx, NULL, true))
|
|
cond_resched();
|
|
|
|
if (ctx->sq_data) {
|
|
struct io_sq_data *sqd = ctx->sq_data;
|
|
struct task_struct *tsk;
|
|
|
|
io_sq_thread_park(sqd);
|
|
tsk = sqd->thread;
|
|
if (tsk && tsk->io_uring && tsk->io_uring->io_wq)
|
|
io_wq_cancel_cb(tsk->io_uring->io_wq,
|
|
io_cancel_ctx_cb, ctx, true);
|
|
io_sq_thread_unpark(sqd);
|
|
}
|
|
|
|
io_req_caches_free(ctx);
|
|
|
|
if (WARN_ON_ONCE(time_after(jiffies, timeout))) {
|
|
/* there is little hope left, don't run it too often */
|
|
interval = HZ * 60;
|
|
}
|
|
/*
|
|
* This is really an uninterruptible wait, as it has to be
|
|
* complete. But it's also run from a kworker, which doesn't
|
|
* take signals, so it's fine to make it interruptible. This
|
|
* avoids scenarios where we knowingly can wait much longer
|
|
* on completions, for example if someone does a SIGSTOP on
|
|
* a task that needs to finish task_work to make this loop
|
|
* complete. That's a synthetic situation that should not
|
|
* cause a stuck task backtrace, and hence a potential panic
|
|
* on stuck tasks if that is enabled.
|
|
*/
|
|
} while (!wait_for_completion_interruptible_timeout(&ctx->ref_comp, interval));
|
|
|
|
init_completion(&exit.completion);
|
|
init_task_work(&exit.task_work, io_tctx_exit_cb);
|
|
exit.ctx = ctx;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
while (!list_empty(&ctx->tctx_list)) {
|
|
WARN_ON_ONCE(time_after(jiffies, timeout));
|
|
|
|
node = list_first_entry(&ctx->tctx_list, struct io_tctx_node,
|
|
ctx_node);
|
|
/* don't spin on a single task if cancellation failed */
|
|
list_rotate_left(&ctx->tctx_list);
|
|
ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL);
|
|
if (WARN_ON_ONCE(ret))
|
|
continue;
|
|
|
|
mutex_unlock(&ctx->uring_lock);
|
|
/*
|
|
* See comment above for
|
|
* wait_for_completion_interruptible_timeout() on why this
|
|
* wait is marked as interruptible.
|
|
*/
|
|
wait_for_completion_interruptible(&exit.completion);
|
|
mutex_lock(&ctx->uring_lock);
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
spin_lock(&ctx->completion_lock);
|
|
spin_unlock(&ctx->completion_lock);
|
|
|
|
/* pairs with RCU read section in io_req_local_work_add() */
|
|
if (ctx->flags & IORING_SETUP_DEFER_TASKRUN)
|
|
synchronize_rcu();
|
|
|
|
io_ring_ctx_free(ctx);
|
|
}
|
|
|
|
static __cold void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
|
|
{
|
|
unsigned long index;
|
|
struct creds *creds;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
percpu_ref_kill(&ctx->refs);
|
|
xa_for_each(&ctx->personalities, index, creds)
|
|
io_unregister_personality(ctx, index);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
flush_delayed_work(&ctx->fallback_work);
|
|
|
|
INIT_WORK(&ctx->exit_work, io_ring_exit_work);
|
|
/*
|
|
* Use system_unbound_wq to avoid spawning tons of event kworkers
|
|
* if we're exiting a ton of rings at the same time. It just adds
|
|
* noise and overhead, there's no discernable change in runtime
|
|
* over using system_wq.
|
|
*/
|
|
queue_work(iou_wq, &ctx->exit_work);
|
|
}
|
|
|
|
static int io_uring_release(struct inode *inode, struct file *file)
|
|
{
|
|
struct io_ring_ctx *ctx = file->private_data;
|
|
|
|
file->private_data = NULL;
|
|
io_ring_ctx_wait_and_kill(ctx);
|
|
return 0;
|
|
}
|
|
|
|
struct io_task_cancel {
|
|
struct task_struct *task;
|
|
bool all;
|
|
};
|
|
|
|
static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
|
|
{
|
|
struct io_kiocb *req = container_of(work, struct io_kiocb, work);
|
|
struct io_task_cancel *cancel = data;
|
|
|
|
return io_match_task_safe(req, cancel->task, cancel->all);
|
|
}
|
|
|
|
static __cold bool io_cancel_defer_files(struct io_ring_ctx *ctx,
|
|
struct task_struct *task,
|
|
bool cancel_all)
|
|
{
|
|
struct io_defer_entry *de;
|
|
LIST_HEAD(list);
|
|
|
|
spin_lock(&ctx->completion_lock);
|
|
list_for_each_entry_reverse(de, &ctx->defer_list, list) {
|
|
if (io_match_task_safe(de->req, task, cancel_all)) {
|
|
list_cut_position(&list, &ctx->defer_list, &de->list);
|
|
break;
|
|
}
|
|
}
|
|
spin_unlock(&ctx->completion_lock);
|
|
if (list_empty(&list))
|
|
return false;
|
|
|
|
while (!list_empty(&list)) {
|
|
de = list_first_entry(&list, struct io_defer_entry, list);
|
|
list_del_init(&de->list);
|
|
io_req_task_queue_fail(de->req, -ECANCELED);
|
|
kfree(de);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)
|
|
{
|
|
struct io_tctx_node *node;
|
|
enum io_wq_cancel cret;
|
|
bool ret = false;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
|
|
struct io_uring_task *tctx = node->task->io_uring;
|
|
|
|
/*
|
|
* io_wq will stay alive while we hold uring_lock, because it's
|
|
* killed after ctx nodes, which requires to take the lock.
|
|
*/
|
|
if (!tctx || !tctx->io_wq)
|
|
continue;
|
|
cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true);
|
|
ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
|
|
struct task_struct *task,
|
|
bool cancel_all)
|
|
{
|
|
struct io_task_cancel cancel = { .task = task, .all = cancel_all, };
|
|
struct io_uring_task *tctx = task ? task->io_uring : NULL;
|
|
enum io_wq_cancel cret;
|
|
bool ret = false;
|
|
|
|
/* set it so io_req_local_work_add() would wake us up */
|
|
if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
|
|
atomic_set(&ctx->cq_wait_nr, 1);
|
|
smp_mb();
|
|
}
|
|
|
|
/* failed during ring init, it couldn't have issued any requests */
|
|
if (!ctx->rings)
|
|
return false;
|
|
|
|
if (!task) {
|
|
ret |= io_uring_try_cancel_iowq(ctx);
|
|
} else if (tctx && tctx->io_wq) {
|
|
/*
|
|
* Cancels requests of all rings, not only @ctx, but
|
|
* it's fine as the task is in exit/exec.
|
|
*/
|
|
cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb,
|
|
&cancel, true);
|
|
ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
|
|
}
|
|
|
|
/* SQPOLL thread does its own polling */
|
|
if ((!(ctx->flags & IORING_SETUP_SQPOLL) && cancel_all) ||
|
|
(ctx->sq_data && ctx->sq_data->thread == current)) {
|
|
while (!wq_list_empty(&ctx->iopoll_list)) {
|
|
io_iopoll_try_reap_events(ctx);
|
|
ret = true;
|
|
cond_resched();
|
|
}
|
|
}
|
|
|
|
if ((ctx->flags & IORING_SETUP_DEFER_TASKRUN) &&
|
|
io_allowed_defer_tw_run(ctx))
|
|
ret |= io_run_local_work(ctx, INT_MAX) > 0;
|
|
ret |= io_cancel_defer_files(ctx, task, cancel_all);
|
|
mutex_lock(&ctx->uring_lock);
|
|
ret |= io_poll_remove_all(ctx, task, cancel_all);
|
|
ret |= io_waitid_remove_all(ctx, task, cancel_all);
|
|
ret |= io_futex_remove_all(ctx, task, cancel_all);
|
|
ret |= io_uring_try_cancel_uring_cmd(ctx, task, cancel_all);
|
|
mutex_unlock(&ctx->uring_lock);
|
|
ret |= io_kill_timeouts(ctx, task, cancel_all);
|
|
if (task)
|
|
ret |= io_run_task_work() > 0;
|
|
else
|
|
ret |= flush_delayed_work(&ctx->fallback_work);
|
|
return ret;
|
|
}
|
|
|
|
static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked)
|
|
{
|
|
if (tracked)
|
|
return atomic_read(&tctx->inflight_tracked);
|
|
return percpu_counter_sum(&tctx->inflight);
|
|
}
|
|
|
|
/*
|
|
* Find any io_uring ctx that this task has registered or done IO on, and cancel
|
|
* requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation.
|
|
*/
|
|
__cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd)
|
|
{
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
struct io_ring_ctx *ctx;
|
|
struct io_tctx_node *node;
|
|
unsigned long index;
|
|
s64 inflight;
|
|
DEFINE_WAIT(wait);
|
|
|
|
WARN_ON_ONCE(sqd && sqd->thread != current);
|
|
|
|
if (!current->io_uring)
|
|
return;
|
|
if (tctx->io_wq)
|
|
io_wq_exit_start(tctx->io_wq);
|
|
|
|
atomic_inc(&tctx->in_cancel);
|
|
do {
|
|
bool loop = false;
|
|
|
|
io_uring_drop_tctx_refs(current);
|
|
if (!tctx_inflight(tctx, !cancel_all))
|
|
break;
|
|
|
|
/* read completions before cancelations */
|
|
inflight = tctx_inflight(tctx, false);
|
|
if (!inflight)
|
|
break;
|
|
|
|
if (!sqd) {
|
|
xa_for_each(&tctx->xa, index, node) {
|
|
/* sqpoll task will cancel all its requests */
|
|
if (node->ctx->sq_data)
|
|
continue;
|
|
loop |= io_uring_try_cancel_requests(node->ctx,
|
|
current, cancel_all);
|
|
}
|
|
} else {
|
|
list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
|
|
loop |= io_uring_try_cancel_requests(ctx,
|
|
current,
|
|
cancel_all);
|
|
}
|
|
|
|
if (loop) {
|
|
cond_resched();
|
|
continue;
|
|
}
|
|
|
|
prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE);
|
|
io_run_task_work();
|
|
io_uring_drop_tctx_refs(current);
|
|
xa_for_each(&tctx->xa, index, node) {
|
|
if (!llist_empty(&node->ctx->work_llist)) {
|
|
WARN_ON_ONCE(node->ctx->submitter_task &&
|
|
node->ctx->submitter_task != current);
|
|
goto end_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, !cancel_all))
|
|
schedule();
|
|
end_wait:
|
|
finish_wait(&tctx->wait, &wait);
|
|
} while (1);
|
|
|
|
io_uring_clean_tctx(tctx);
|
|
if (cancel_all) {
|
|
/*
|
|
* We shouldn't run task_works after cancel, so just leave
|
|
* ->in_cancel set for normal exit.
|
|
*/
|
|
atomic_dec(&tctx->in_cancel);
|
|
/* for exec all current's requests should be gone, kill tctx */
|
|
__io_uring_free(current);
|
|
}
|
|
}
|
|
|
|
void __io_uring_cancel(bool cancel_all)
|
|
{
|
|
io_uring_cancel_generic(cancel_all, NULL);
|
|
}
|
|
|
|
static int io_validate_ext_arg(unsigned flags, const void __user *argp, size_t argsz)
|
|
{
|
|
if (flags & IORING_ENTER_EXT_ARG) {
|
|
struct io_uring_getevents_arg arg;
|
|
|
|
if (argsz != sizeof(arg))
|
|
return -EINVAL;
|
|
if (copy_from_user(&arg, argp, sizeof(arg)))
|
|
return -EFAULT;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz,
|
|
struct __kernel_timespec __user **ts,
|
|
const sigset_t __user **sig)
|
|
{
|
|
struct io_uring_getevents_arg arg;
|
|
|
|
/*
|
|
* If EXT_ARG isn't set, then we have no timespec and the argp pointer
|
|
* is just a pointer to the sigset_t.
|
|
*/
|
|
if (!(flags & IORING_ENTER_EXT_ARG)) {
|
|
*sig = (const sigset_t __user *) argp;
|
|
*ts = NULL;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* EXT_ARG is set - ensure we agree on the size of it and copy in our
|
|
* timespec and sigset_t pointers if good.
|
|
*/
|
|
if (*argsz != sizeof(arg))
|
|
return -EINVAL;
|
|
if (copy_from_user(&arg, argp, sizeof(arg)))
|
|
return -EFAULT;
|
|
if (arg.pad)
|
|
return -EINVAL;
|
|
*sig = u64_to_user_ptr(arg.sigmask);
|
|
*argsz = arg.sigmask_sz;
|
|
*ts = u64_to_user_ptr(arg.ts);
|
|
return 0;
|
|
}
|
|
|
|
SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
|
|
u32, min_complete, u32, flags, const void __user *, argp,
|
|
size_t, argsz)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
struct file *file;
|
|
long ret;
|
|
|
|
if (unlikely(flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
|
|
IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG |
|
|
IORING_ENTER_REGISTERED_RING)))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Ring fd has been registered via IORING_REGISTER_RING_FDS, we
|
|
* need only dereference our task private array to find it.
|
|
*/
|
|
if (flags & IORING_ENTER_REGISTERED_RING) {
|
|
struct io_uring_task *tctx = current->io_uring;
|
|
|
|
if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX))
|
|
return -EINVAL;
|
|
fd = array_index_nospec(fd, IO_RINGFD_REG_MAX);
|
|
file = tctx->registered_rings[fd];
|
|
if (unlikely(!file))
|
|
return -EBADF;
|
|
} else {
|
|
file = fget(fd);
|
|
if (unlikely(!file))
|
|
return -EBADF;
|
|
ret = -EOPNOTSUPP;
|
|
if (unlikely(!io_is_uring_fops(file)))
|
|
goto out;
|
|
}
|
|
|
|
ctx = file->private_data;
|
|
ret = -EBADFD;
|
|
if (unlikely(ctx->flags & IORING_SETUP_R_DISABLED))
|
|
goto out;
|
|
|
|
/*
|
|
* For SQ polling, the thread will do all submissions and completions.
|
|
* Just return the requested submit count, and wake the thread if
|
|
* we were asked to.
|
|
*/
|
|
ret = 0;
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
if (unlikely(ctx->sq_data->thread == NULL)) {
|
|
ret = -EOWNERDEAD;
|
|
goto out;
|
|
}
|
|
if (flags & IORING_ENTER_SQ_WAKEUP)
|
|
wake_up(&ctx->sq_data->wait);
|
|
if (flags & IORING_ENTER_SQ_WAIT)
|
|
io_sqpoll_wait_sq(ctx);
|
|
|
|
ret = to_submit;
|
|
} else if (to_submit) {
|
|
ret = io_uring_add_tctx_node(ctx);
|
|
if (unlikely(ret))
|
|
goto out;
|
|
|
|
mutex_lock(&ctx->uring_lock);
|
|
ret = io_submit_sqes(ctx, to_submit);
|
|
if (ret != to_submit) {
|
|
mutex_unlock(&ctx->uring_lock);
|
|
goto out;
|
|
}
|
|
if (flags & IORING_ENTER_GETEVENTS) {
|
|
if (ctx->syscall_iopoll)
|
|
goto iopoll_locked;
|
|
/*
|
|
* Ignore errors, we'll soon call io_cqring_wait() and
|
|
* it should handle ownership problems if any.
|
|
*/
|
|
if (ctx->flags & IORING_SETUP_DEFER_TASKRUN)
|
|
(void)io_run_local_work_locked(ctx, min_complete);
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
}
|
|
|
|
if (flags & IORING_ENTER_GETEVENTS) {
|
|
int ret2;
|
|
|
|
if (ctx->syscall_iopoll) {
|
|
/*
|
|
* We disallow the app entering submit/complete with
|
|
* polling, but we still need to lock the ring to
|
|
* prevent racing with polled issue that got punted to
|
|
* a workqueue.
|
|
*/
|
|
mutex_lock(&ctx->uring_lock);
|
|
iopoll_locked:
|
|
ret2 = io_validate_ext_arg(flags, argp, argsz);
|
|
if (likely(!ret2)) {
|
|
min_complete = min(min_complete,
|
|
ctx->cq_entries);
|
|
ret2 = io_iopoll_check(ctx, min_complete);
|
|
}
|
|
mutex_unlock(&ctx->uring_lock);
|
|
} else {
|
|
const sigset_t __user *sig;
|
|
struct __kernel_timespec __user *ts;
|
|
|
|
ret2 = io_get_ext_arg(flags, argp, &argsz, &ts, &sig);
|
|
if (likely(!ret2)) {
|
|
min_complete = min(min_complete,
|
|
ctx->cq_entries);
|
|
ret2 = io_cqring_wait(ctx, min_complete, sig,
|
|
argsz, ts);
|
|
}
|
|
}
|
|
|
|
if (!ret) {
|
|
ret = ret2;
|
|
|
|
/*
|
|
* EBADR indicates that one or more CQE were dropped.
|
|
* Once the user has been informed we can clear the bit
|
|
* as they are obviously ok with those drops.
|
|
*/
|
|
if (unlikely(ret2 == -EBADR))
|
|
clear_bit(IO_CHECK_CQ_DROPPED_BIT,
|
|
&ctx->check_cq);
|
|
}
|
|
}
|
|
out:
|
|
if (!(flags & IORING_ENTER_REGISTERED_RING))
|
|
fput(file);
|
|
return ret;
|
|
}
|
|
|
|
static const struct file_operations io_uring_fops = {
|
|
.release = io_uring_release,
|
|
.mmap = io_uring_mmap,
|
|
.get_unmapped_area = io_uring_get_unmapped_area,
|
|
#ifndef CONFIG_MMU
|
|
.mmap_capabilities = io_uring_nommu_mmap_capabilities,
|
|
#endif
|
|
.poll = io_uring_poll,
|
|
#ifdef CONFIG_PROC_FS
|
|
.show_fdinfo = io_uring_show_fdinfo,
|
|
#endif
|
|
};
|
|
|
|
bool io_is_uring_fops(struct file *file)
|
|
{
|
|
return file->f_op == &io_uring_fops;
|
|
}
|
|
|
|
static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx,
|
|
struct io_uring_params *p)
|
|
{
|
|
struct io_rings *rings;
|
|
size_t size, sq_array_offset;
|
|
void *ptr;
|
|
|
|
/* make sure these are sane, as we already accounted them */
|
|
ctx->sq_entries = p->sq_entries;
|
|
ctx->cq_entries = p->cq_entries;
|
|
|
|
size = rings_size(ctx, p->sq_entries, p->cq_entries, &sq_array_offset);
|
|
if (size == SIZE_MAX)
|
|
return -EOVERFLOW;
|
|
|
|
if (!(ctx->flags & IORING_SETUP_NO_MMAP))
|
|
rings = io_pages_map(&ctx->ring_pages, &ctx->n_ring_pages, size);
|
|
else
|
|
rings = io_rings_map(ctx, p->cq_off.user_addr, size);
|
|
|
|
if (IS_ERR(rings))
|
|
return PTR_ERR(rings);
|
|
|
|
ctx->rings = rings;
|
|
if (!(ctx->flags & IORING_SETUP_NO_SQARRAY))
|
|
ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
|
|
rings->sq_ring_mask = p->sq_entries - 1;
|
|
rings->cq_ring_mask = p->cq_entries - 1;
|
|
rings->sq_ring_entries = p->sq_entries;
|
|
rings->cq_ring_entries = p->cq_entries;
|
|
|
|
if (p->flags & IORING_SETUP_SQE128)
|
|
size = array_size(2 * sizeof(struct io_uring_sqe), p->sq_entries);
|
|
else
|
|
size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
|
|
if (size == SIZE_MAX) {
|
|
io_rings_free(ctx);
|
|
return -EOVERFLOW;
|
|
}
|
|
|
|
if (!(ctx->flags & IORING_SETUP_NO_MMAP))
|
|
ptr = io_pages_map(&ctx->sqe_pages, &ctx->n_sqe_pages, size);
|
|
else
|
|
ptr = io_sqes_map(ctx, p->sq_off.user_addr, size);
|
|
|
|
if (IS_ERR(ptr)) {
|
|
io_rings_free(ctx);
|
|
return PTR_ERR(ptr);
|
|
}
|
|
|
|
ctx->sq_sqes = ptr;
|
|
return 0;
|
|
}
|
|
|
|
static int io_uring_install_fd(struct file *file)
|
|
{
|
|
int fd;
|
|
|
|
fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
|
|
if (fd < 0)
|
|
return fd;
|
|
fd_install(fd, file);
|
|
return fd;
|
|
}
|
|
|
|
/*
|
|
* Allocate an anonymous fd, this is what constitutes the application
|
|
* visible backing of an io_uring instance. The application mmaps this
|
|
* fd to gain access to the SQ/CQ ring details.
|
|
*/
|
|
static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
|
|
{
|
|
/* Create a new inode so that the LSM can block the creation. */
|
|
return anon_inode_create_getfile("[io_uring]", &io_uring_fops, ctx,
|
|
O_RDWR | O_CLOEXEC, NULL);
|
|
}
|
|
|
|
static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
|
|
struct io_uring_params __user *params)
|
|
{
|
|
struct io_ring_ctx *ctx;
|
|
struct io_uring_task *tctx;
|
|
struct file *file;
|
|
int ret;
|
|
|
|
if (!entries)
|
|
return -EINVAL;
|
|
if (entries > IORING_MAX_ENTRIES) {
|
|
if (!(p->flags & IORING_SETUP_CLAMP))
|
|
return -EINVAL;
|
|
entries = IORING_MAX_ENTRIES;
|
|
}
|
|
|
|
if ((p->flags & IORING_SETUP_REGISTERED_FD_ONLY)
|
|
&& !(p->flags & IORING_SETUP_NO_MMAP))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* Use twice as many entries for the CQ ring. It's possible for the
|
|
* application to drive a higher depth than the size of the SQ ring,
|
|
* since the sqes are only used at submission time. This allows for
|
|
* some flexibility in overcommitting a bit. If the application has
|
|
* set IORING_SETUP_CQSIZE, it will have passed in the desired number
|
|
* of CQ ring entries manually.
|
|
*/
|
|
p->sq_entries = roundup_pow_of_two(entries);
|
|
if (p->flags & IORING_SETUP_CQSIZE) {
|
|
/*
|
|
* If IORING_SETUP_CQSIZE is set, we do the same roundup
|
|
* to a power-of-two, if it isn't already. We do NOT impose
|
|
* any cq vs sq ring sizing.
|
|
*/
|
|
if (!p->cq_entries)
|
|
return -EINVAL;
|
|
if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
|
|
if (!(p->flags & IORING_SETUP_CLAMP))
|
|
return -EINVAL;
|
|
p->cq_entries = IORING_MAX_CQ_ENTRIES;
|
|
}
|
|
p->cq_entries = roundup_pow_of_two(p->cq_entries);
|
|
if (p->cq_entries < p->sq_entries)
|
|
return -EINVAL;
|
|
} else {
|
|
p->cq_entries = 2 * p->sq_entries;
|
|
}
|
|
|
|
ctx = io_ring_ctx_alloc(p);
|
|
if (!ctx)
|
|
return -ENOMEM;
|
|
|
|
if ((ctx->flags & IORING_SETUP_DEFER_TASKRUN) &&
|
|
!(ctx->flags & IORING_SETUP_IOPOLL) &&
|
|
!(ctx->flags & IORING_SETUP_SQPOLL))
|
|
ctx->task_complete = true;
|
|
|
|
if (ctx->task_complete || (ctx->flags & IORING_SETUP_IOPOLL))
|
|
ctx->lockless_cq = true;
|
|
|
|
/*
|
|
* lazy poll_wq activation relies on ->task_complete for synchronisation
|
|
* purposes, see io_activate_pollwq()
|
|
*/
|
|
if (!ctx->task_complete)
|
|
ctx->poll_activated = true;
|
|
|
|
/*
|
|
* When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
|
|
* space applications don't need to do io completion events
|
|
* polling again, they can rely on io_sq_thread to do polling
|
|
* work, which can reduce cpu usage and uring_lock contention.
|
|
*/
|
|
if (ctx->flags & IORING_SETUP_IOPOLL &&
|
|
!(ctx->flags & IORING_SETUP_SQPOLL))
|
|
ctx->syscall_iopoll = 1;
|
|
|
|
ctx->compat = in_compat_syscall();
|
|
if (!ns_capable_noaudit(&init_user_ns, CAP_IPC_LOCK))
|
|
ctx->user = get_uid(current_user());
|
|
|
|
/*
|
|
* For SQPOLL, we just need a wakeup, always. For !SQPOLL, if
|
|
* COOP_TASKRUN is set, then IPIs are never needed by the app.
|
|
*/
|
|
ret = -EINVAL;
|
|
if (ctx->flags & IORING_SETUP_SQPOLL) {
|
|
/* IPI related flags don't make sense with SQPOLL */
|
|
if (ctx->flags & (IORING_SETUP_COOP_TASKRUN |
|
|
IORING_SETUP_TASKRUN_FLAG |
|
|
IORING_SETUP_DEFER_TASKRUN))
|
|
goto err;
|
|
ctx->notify_method = TWA_SIGNAL_NO_IPI;
|
|
} else if (ctx->flags & IORING_SETUP_COOP_TASKRUN) {
|
|
ctx->notify_method = TWA_SIGNAL_NO_IPI;
|
|
} else {
|
|
if (ctx->flags & IORING_SETUP_TASKRUN_FLAG &&
|
|
!(ctx->flags & IORING_SETUP_DEFER_TASKRUN))
|
|
goto err;
|
|
ctx->notify_method = TWA_SIGNAL;
|
|
}
|
|
|
|
/*
|
|
* For DEFER_TASKRUN we require the completion task to be the same as the
|
|
* submission task. This implies that there is only one submitter, so enforce
|
|
* that.
|
|
*/
|
|
if (ctx->flags & IORING_SETUP_DEFER_TASKRUN &&
|
|
!(ctx->flags & IORING_SETUP_SINGLE_ISSUER)) {
|
|
goto err;
|
|
}
|
|
|
|
/*
|
|
* This is just grabbed for accounting purposes. When a process exits,
|
|
* the mm is exited and dropped before the files, hence we need to hang
|
|
* on to this mm purely for the purposes of being able to unaccount
|
|
* memory (locked/pinned vm). It's not used for anything else.
|
|
*/
|
|
mmgrab(current->mm);
|
|
ctx->mm_account = current->mm;
|
|
|
|
ret = io_allocate_scq_urings(ctx, p);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = io_sq_offload_create(ctx, p);
|
|
if (ret)
|
|
goto err;
|
|
|
|
ret = io_rsrc_init(ctx);
|
|
if (ret)
|
|
goto err;
|
|
|
|
p->sq_off.head = offsetof(struct io_rings, sq.head);
|
|
p->sq_off.tail = offsetof(struct io_rings, sq.tail);
|
|
p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
|
|
p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
|
|
p->sq_off.flags = offsetof(struct io_rings, sq_flags);
|
|
p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
|
|
if (!(ctx->flags & IORING_SETUP_NO_SQARRAY))
|
|
p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
|
|
p->sq_off.resv1 = 0;
|
|
if (!(ctx->flags & IORING_SETUP_NO_MMAP))
|
|
p->sq_off.user_addr = 0;
|
|
|
|
p->cq_off.head = offsetof(struct io_rings, cq.head);
|
|
p->cq_off.tail = offsetof(struct io_rings, cq.tail);
|
|
p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
|
|
p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
|
|
p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
|
|
p->cq_off.cqes = offsetof(struct io_rings, cqes);
|
|
p->cq_off.flags = offsetof(struct io_rings, cq_flags);
|
|
p->cq_off.resv1 = 0;
|
|
if (!(ctx->flags & IORING_SETUP_NO_MMAP))
|
|
p->cq_off.user_addr = 0;
|
|
|
|
p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
|
|
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_NATIVE_WORKERS |
|
|
IORING_FEAT_RSRC_TAGS | IORING_FEAT_CQE_SKIP |
|
|
IORING_FEAT_LINKED_FILE | IORING_FEAT_REG_REG_RING |
|
|
IORING_FEAT_RECVSEND_BUNDLE;
|
|
|
|
if (copy_to_user(params, p, sizeof(*p))) {
|
|
ret = -EFAULT;
|
|
goto err;
|
|
}
|
|
|
|
if (ctx->flags & IORING_SETUP_SINGLE_ISSUER
|
|
&& !(ctx->flags & IORING_SETUP_R_DISABLED))
|
|
WRITE_ONCE(ctx->submitter_task, get_task_struct(current));
|
|
|
|
file = io_uring_get_file(ctx);
|
|
if (IS_ERR(file)) {
|
|
ret = PTR_ERR(file);
|
|
goto err;
|
|
}
|
|
|
|
ret = __io_uring_add_tctx_node(ctx);
|
|
if (ret)
|
|
goto err_fput;
|
|
tctx = current->io_uring;
|
|
|
|
/*
|
|
* Install ring fd as the very last thing, so we don't risk someone
|
|
* having closed it before we finish setup
|
|
*/
|
|
if (p->flags & IORING_SETUP_REGISTERED_FD_ONLY)
|
|
ret = io_ring_add_registered_file(tctx, file, 0, IO_RINGFD_REG_MAX);
|
|
else
|
|
ret = io_uring_install_fd(file);
|
|
if (ret < 0)
|
|
goto err_fput;
|
|
|
|
trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
|
|
return ret;
|
|
err:
|
|
io_ring_ctx_wait_and_kill(ctx);
|
|
return ret;
|
|
err_fput:
|
|
fput(file);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Sets up an aio uring context, and returns the fd. Applications asks for a
|
|
* ring size, we return the actual sq/cq ring sizes (among other things) in the
|
|
* params structure passed in.
|
|
*/
|
|
static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
|
|
{
|
|
struct io_uring_params p;
|
|
int i;
|
|
|
|
if (copy_from_user(&p, params, sizeof(p)))
|
|
return -EFAULT;
|
|
for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
|
|
if (p.resv[i])
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
|
|
IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
|
|
IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
|
|
IORING_SETUP_R_DISABLED | IORING_SETUP_SUBMIT_ALL |
|
|
IORING_SETUP_COOP_TASKRUN | IORING_SETUP_TASKRUN_FLAG |
|
|
IORING_SETUP_SQE128 | IORING_SETUP_CQE32 |
|
|
IORING_SETUP_SINGLE_ISSUER | IORING_SETUP_DEFER_TASKRUN |
|
|
IORING_SETUP_NO_MMAP | IORING_SETUP_REGISTERED_FD_ONLY |
|
|
IORING_SETUP_NO_SQARRAY))
|
|
return -EINVAL;
|
|
|
|
return io_uring_create(entries, &p, params);
|
|
}
|
|
|
|
static inline bool io_uring_allowed(void)
|
|
{
|
|
int disabled = READ_ONCE(sysctl_io_uring_disabled);
|
|
kgid_t io_uring_group;
|
|
|
|
if (disabled == 2)
|
|
return false;
|
|
|
|
if (disabled == 0 || capable(CAP_SYS_ADMIN))
|
|
return true;
|
|
|
|
io_uring_group = make_kgid(&init_user_ns, sysctl_io_uring_group);
|
|
if (!gid_valid(io_uring_group))
|
|
return false;
|
|
|
|
return in_group_p(io_uring_group);
|
|
}
|
|
|
|
SYSCALL_DEFINE2(io_uring_setup, u32, entries,
|
|
struct io_uring_params __user *, params)
|
|
{
|
|
if (!io_uring_allowed())
|
|
return -EPERM;
|
|
|
|
return io_uring_setup(entries, params);
|
|
}
|
|
|
|
static int __init io_uring_init(void)
|
|
{
|
|
#define __BUILD_BUG_VERIFY_OFFSET_SIZE(stype, eoffset, esize, ename) do { \
|
|
BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
|
|
BUILD_BUG_ON(sizeof_field(stype, ename) != esize); \
|
|
} while (0)
|
|
|
|
#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
|
|
__BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, sizeof(etype), ename)
|
|
#define BUILD_BUG_SQE_ELEM_SIZE(eoffset, esize, ename) \
|
|
__BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, esize, ename)
|
|
BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
|
|
BUILD_BUG_SQE_ELEM(0, __u8, opcode);
|
|
BUILD_BUG_SQE_ELEM(1, __u8, flags);
|
|
BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
|
|
BUILD_BUG_SQE_ELEM(4, __s32, fd);
|
|
BUILD_BUG_SQE_ELEM(8, __u64, off);
|
|
BUILD_BUG_SQE_ELEM(8, __u64, addr2);
|
|
BUILD_BUG_SQE_ELEM(8, __u32, cmd_op);
|
|
BUILD_BUG_SQE_ELEM(12, __u32, __pad1);
|
|
BUILD_BUG_SQE_ELEM(16, __u64, addr);
|
|
BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
|
|
BUILD_BUG_SQE_ELEM(24, __u32, len);
|
|
BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
|
|
BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
|
|
BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
|
|
BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, rename_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, unlink_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, hardlink_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, xattr_flags);
|
|
BUILD_BUG_SQE_ELEM(28, __u32, msg_ring_flags);
|
|
BUILD_BUG_SQE_ELEM(32, __u64, user_data);
|
|
BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
|
|
BUILD_BUG_SQE_ELEM(40, __u16, buf_group);
|
|
BUILD_BUG_SQE_ELEM(42, __u16, personality);
|
|
BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
|
|
BUILD_BUG_SQE_ELEM(44, __u32, file_index);
|
|
BUILD_BUG_SQE_ELEM(44, __u16, addr_len);
|
|
BUILD_BUG_SQE_ELEM(46, __u16, __pad3[0]);
|
|
BUILD_BUG_SQE_ELEM(48, __u64, addr3);
|
|
BUILD_BUG_SQE_ELEM_SIZE(48, 0, cmd);
|
|
BUILD_BUG_SQE_ELEM(56, __u64, __pad2);
|
|
|
|
BUILD_BUG_ON(sizeof(struct io_uring_files_update) !=
|
|
sizeof(struct io_uring_rsrc_update));
|
|
BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) >
|
|
sizeof(struct io_uring_rsrc_update2));
|
|
|
|
/* ->buf_index is u16 */
|
|
BUILD_BUG_ON(offsetof(struct io_uring_buf_ring, bufs) != 0);
|
|
BUILD_BUG_ON(offsetof(struct io_uring_buf, resv) !=
|
|
offsetof(struct io_uring_buf_ring, tail));
|
|
|
|
/* should fit into one byte */
|
|
BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));
|
|
BUILD_BUG_ON(SQE_COMMON_FLAGS >= (1 << 8));
|
|
BUILD_BUG_ON((SQE_VALID_FLAGS | SQE_COMMON_FLAGS) != SQE_VALID_FLAGS);
|
|
|
|
BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof_field(struct io_kiocb, flags));
|
|
|
|
BUILD_BUG_ON(sizeof(atomic_t) != sizeof(u32));
|
|
|
|
/* top 8bits are for internal use */
|
|
BUILD_BUG_ON((IORING_URING_CMD_MASK & 0xff000000) != 0);
|
|
|
|
io_uring_optable_init();
|
|
|
|
/*
|
|
* Allow user copy in the per-command field, which starts after the
|
|
* file in io_kiocb and until the opcode field. The openat2 handling
|
|
* requires copying in user memory into the io_kiocb object in that
|
|
* range, and HARDENED_USERCOPY will complain if we haven't
|
|
* correctly annotated this range.
|
|
*/
|
|
req_cachep = kmem_cache_create_usercopy("io_kiocb",
|
|
sizeof(struct io_kiocb), 0,
|
|
SLAB_HWCACHE_ALIGN | SLAB_PANIC |
|
|
SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU,
|
|
offsetof(struct io_kiocb, cmd.data),
|
|
sizeof_field(struct io_kiocb, cmd.data), NULL);
|
|
io_buf_cachep = KMEM_CACHE(io_buffer,
|
|
SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT);
|
|
|
|
iou_wq = alloc_workqueue("iou_exit", WQ_UNBOUND, 64);
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
register_sysctl_init("kernel", kernel_io_uring_disabled_table);
|
|
#endif
|
|
|
|
return 0;
|
|
};
|
|
__initcall(io_uring_init);
|