1 // SPDX-License-Identifier: GPL-2.0
3 * Shared application/kernel submission and completion ring pairs, for
4 * supporting fast/efficient IO.
6 * A note on the read/write ordering memory barriers that are matched between
7 * the application and kernel side.
9 * After the application reads the CQ ring tail, it must use an
10 * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
11 * before writing the tail (using smp_load_acquire to read the tail will
12 * do). It also needs a smp_mb() before updating CQ head (ordering the
13 * entry load(s) with the head store), pairing with an implicit barrier
14 * through a control-dependency in io_get_cqring (smp_store_release to
15 * store head will do). Failure to do so could lead to reading invalid
18 * Likewise, the application must use an appropriate smp_wmb() before
19 * writing the SQ tail (ordering SQ entry stores with the tail store),
20 * which pairs with smp_load_acquire in io_get_sqring (smp_store_release
21 * to store the tail will do). And it needs a barrier ordering the SQ
22 * head load before writing new SQ entries (smp_load_acquire to read
25 * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
26 * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
27 * updating the SQ tail; a full memory barrier smp_mb() is needed
30 * Also see the examples in the liburing library:
32 * git://git.kernel.dk/liburing
34 * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
35 * from data shared between the kernel and application. This is done both
36 * for ordering purposes, but also to ensure that once a value is loaded from
37 * data that the application could potentially modify, it remains stable.
39 * Copyright (C) 2018-2019 Jens Axboe
40 * Copyright (c) 2018-2019 Christoph Hellwig
42 #include <linux/kernel.h>
43 #include <linux/init.h>
44 #include <linux/errno.h>
45 #include <linux/syscalls.h>
46 #include <linux/compat.h>
47 #include <net/compat.h>
48 #include <linux/refcount.h>
49 #include <linux/uio.h>
50 #include <linux/bits.h>
52 #include <linux/sched/signal.h>
54 #include <linux/file.h>
55 #include <linux/fdtable.h>
57 #include <linux/mman.h>
58 #include <linux/mmu_context.h>
59 #include <linux/percpu.h>
60 #include <linux/slab.h>
61 #include <linux/kthread.h>
62 #include <linux/blkdev.h>
63 #include <linux/bvec.h>
64 #include <linux/net.h>
66 #include <net/af_unix.h>
68 #include <linux/anon_inodes.h>
69 #include <linux/sched/mm.h>
70 #include <linux/uaccess.h>
71 #include <linux/nospec.h>
72 #include <linux/sizes.h>
73 #include <linux/hugetlb.h>
74 #include <linux/highmem.h>
75 #include <linux/namei.h>
76 #include <linux/fsnotify.h>
77 #include <linux/fadvise.h>
78 #include <linux/eventpoll.h>
79 #include <linux/fs_struct.h>
80 #include <linux/splice.h>
81 #include <linux/task_work.h>
83 #define CREATE_TRACE_POINTS
84 #include <trace/events/io_uring.h>
86 #include <uapi/linux/io_uring.h>
91 #define IORING_MAX_ENTRIES 32768
92 #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
95 * Shift of 9 is 512 entries, or exactly one page on 64-bit archs
97 #define IORING_FILE_TABLE_SHIFT 9
98 #define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT)
99 #define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1)
100 #define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE)
103 u32 head ____cacheline_aligned_in_smp;
104 u32 tail ____cacheline_aligned_in_smp;
108 * This data is shared with the application through the mmap at offsets
109 * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
111 * The offsets to the member fields are published through struct
112 * io_sqring_offsets when calling io_uring_setup.
116 * Head and tail offsets into the ring; the offsets need to be
117 * masked to get valid indices.
119 * The kernel controls head of the sq ring and the tail of the cq ring,
120 * and the application controls tail of the sq ring and the head of the
123 struct io_uring sq, cq;
125 * Bitmasks to apply to head and tail offsets (constant, equals
128 u32 sq_ring_mask, cq_ring_mask;
129 /* Ring sizes (constant, power of 2) */
130 u32 sq_ring_entries, cq_ring_entries;
132 * Number of invalid entries dropped by the kernel due to
133 * invalid index stored in array
135 * Written by the kernel, shouldn't be modified by the
136 * application (i.e. get number of "new events" by comparing to
139 * After a new SQ head value was read by the application this
140 * counter includes all submissions that were dropped reaching
141 * the new SQ head (and possibly more).
147 * Written by the kernel, shouldn't be modified by the
150 * The application needs a full memory barrier before checking
151 * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
155 * Number of completion events lost because the queue was full;
156 * this should be avoided by the application by making sure
157 * there are not more requests pending than there is space in
158 * the completion queue.
160 * Written by the kernel, shouldn't be modified by the
161 * application (i.e. get number of "new events" by comparing to
164 * As completion events come in out of order this counter is not
165 * ordered with any other data.
169 * Ring buffer of completion events.
171 * The kernel writes completion events fresh every time they are
172 * produced, so the application is allowed to modify pending
175 struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
178 struct io_mapped_ubuf {
181 struct bio_vec *bvec;
182 unsigned int nr_bvecs;
185 struct fixed_file_table {
189 struct fixed_file_ref_node {
190 struct percpu_ref refs;
191 struct list_head node;
192 struct list_head file_list;
193 struct fixed_file_data *file_data;
194 struct work_struct work;
197 struct fixed_file_data {
198 struct fixed_file_table *table;
199 struct io_ring_ctx *ctx;
201 struct percpu_ref *cur_refs;
202 struct percpu_ref refs;
203 struct completion done;
204 struct list_head ref_list;
209 struct list_head list;
217 struct percpu_ref refs;
218 } ____cacheline_aligned_in_smp;
222 unsigned int compat: 1;
223 unsigned int account_mem: 1;
224 unsigned int cq_overflow_flushed: 1;
225 unsigned int drain_next: 1;
226 unsigned int eventfd_async: 1;
229 * Ring buffer of indices into array of io_uring_sqe, which is
230 * mmapped by the application using the IORING_OFF_SQES offset.
232 * This indirection could e.g. be used to assign fixed
233 * io_uring_sqe entries to operations and only submit them to
234 * the queue when needed.
236 * The kernel modifies neither the indices array nor the entries
240 unsigned cached_sq_head;
243 unsigned sq_thread_idle;
244 unsigned cached_sq_dropped;
245 atomic_t cached_cq_overflow;
246 unsigned long sq_check_overflow;
248 struct list_head defer_list;
249 struct list_head timeout_list;
250 struct list_head cq_overflow_list;
252 wait_queue_head_t inflight_wait;
253 struct io_uring_sqe *sq_sqes;
254 } ____cacheline_aligned_in_smp;
256 struct io_rings *rings;
260 struct task_struct *sqo_thread; /* if using sq thread polling */
261 struct mm_struct *sqo_mm;
262 wait_queue_head_t sqo_wait;
265 * If used, fixed file set. Writers must ensure that ->refs is dead,
266 * readers must ensure that ->refs is alive as long as the file* is
267 * used. Only updated through io_uring_register(2).
269 struct fixed_file_data *file_data;
270 unsigned nr_user_files;
272 struct file *ring_file;
274 /* if used, fixed mapped user buffers */
275 unsigned nr_user_bufs;
276 struct io_mapped_ubuf *user_bufs;
278 struct user_struct *user;
280 const struct cred *creds;
282 /* 0 is for ctx quiesce/reinit/free, 1 is for sqo_thread started */
283 struct completion *completions;
285 /* if all else fails... */
286 struct io_kiocb *fallback_req;
288 #if defined(CONFIG_UNIX)
289 struct socket *ring_sock;
292 struct idr io_buffer_idr;
294 struct idr personality_idr;
297 unsigned cached_cq_tail;
300 atomic_t cq_timeouts;
301 unsigned long cq_check_overflow;
302 struct wait_queue_head cq_wait;
303 struct fasync_struct *cq_fasync;
304 struct eventfd_ctx *cq_ev_fd;
305 } ____cacheline_aligned_in_smp;
308 struct mutex uring_lock;
309 wait_queue_head_t wait;
310 } ____cacheline_aligned_in_smp;
313 spinlock_t completion_lock;
316 * ->poll_list is protected by the ctx->uring_lock for
317 * io_uring instances that don't use IORING_SETUP_SQPOLL.
318 * For SQPOLL, only the single threaded io_sq_thread() will
319 * manipulate the list, hence no extra locking is needed there.
321 struct list_head poll_list;
322 struct hlist_head *cancel_hash;
323 unsigned cancel_hash_bits;
324 bool poll_multi_file;
326 spinlock_t inflight_lock;
327 struct list_head inflight_list;
328 } ____cacheline_aligned_in_smp;
330 struct work_struct exit_work;
334 * First field must be the file pointer in all the
335 * iocb unions! See also 'struct kiocb' in <linux/fs.h>
337 struct io_poll_iocb {
340 struct wait_queue_head *head;
346 struct wait_queue_entry wait;
351 struct file *put_file;
355 struct io_timeout_data {
356 struct io_kiocb *req;
357 struct hrtimer timer;
358 struct timespec64 ts;
359 enum hrtimer_mode mode;
364 struct sockaddr __user *addr;
365 int __user *addr_len;
367 unsigned long nofile;
391 /* NOTE: kiocb has the file as the first member, so don't do it here */
399 struct sockaddr __user *addr;
406 struct user_msghdr __user *msg;
412 struct io_buffer *kbuf;
421 struct filename *filename;
422 struct statx __user *buffer;
424 unsigned long nofile;
427 struct io_files_update {
453 struct epoll_event event;
457 struct file *file_out;
458 struct file *file_in;
465 struct io_provide_buf {
474 struct io_async_connect {
475 struct sockaddr_storage address;
478 struct io_async_msghdr {
479 struct iovec fast_iov[UIO_FASTIOV];
481 struct sockaddr __user *uaddr;
483 struct sockaddr_storage addr;
487 struct iovec fast_iov[UIO_FASTIOV];
493 struct io_async_ctx {
495 struct io_async_rw rw;
496 struct io_async_msghdr msg;
497 struct io_async_connect connect;
498 struct io_timeout_data timeout;
503 REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
504 REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
505 REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
506 REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
507 REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
508 REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
516 REQ_F_IOPOLL_COMPLETED_BIT,
517 REQ_F_LINK_TIMEOUT_BIT,
521 REQ_F_TIMEOUT_NOSEQ_BIT,
522 REQ_F_COMP_LOCKED_BIT,
523 REQ_F_NEED_CLEANUP_BIT,
526 REQ_F_BUFFER_SELECTED_BIT,
527 REQ_F_NO_FILE_TABLE_BIT,
529 /* not a real bit, just to check we're not overflowing the space */
535 REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
536 /* drain existing IO first */
537 REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
539 REQ_F_LINK = BIT(REQ_F_LINK_BIT),
540 /* doesn't sever on completion < 0 */
541 REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
543 REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
544 /* IOSQE_BUFFER_SELECT */
545 REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
548 REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT),
549 /* already grabbed next link */
550 REQ_F_LINK_NEXT = BIT(REQ_F_LINK_NEXT_BIT),
551 /* fail rest of links */
552 REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT),
553 /* on inflight list */
554 REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
555 /* read/write uses file position */
556 REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
557 /* must not punt to workers */
558 REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
559 /* polled IO has completed */
560 REQ_F_IOPOLL_COMPLETED = BIT(REQ_F_IOPOLL_COMPLETED_BIT),
561 /* has linked timeout */
562 REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
563 /* timeout request */
564 REQ_F_TIMEOUT = BIT(REQ_F_TIMEOUT_BIT),
566 REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
567 /* must be punted even for NONBLOCK */
568 REQ_F_MUST_PUNT = BIT(REQ_F_MUST_PUNT_BIT),
569 /* no timeout sequence */
570 REQ_F_TIMEOUT_NOSEQ = BIT(REQ_F_TIMEOUT_NOSEQ_BIT),
571 /* completion under lock */
572 REQ_F_COMP_LOCKED = BIT(REQ_F_COMP_LOCKED_BIT),
574 REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
575 /* in overflow list */
576 REQ_F_OVERFLOW = BIT(REQ_F_OVERFLOW_BIT),
577 /* already went through poll handler */
578 REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
579 /* buffer already selected */
580 REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
581 /* doesn't need file table for this request */
582 REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
586 struct io_poll_iocb poll;
587 struct io_wq_work work;
591 * NOTE! Each of the iocb union members has the file pointer
592 * as the first entry in their struct definition. So you can
593 * access the file pointer through any of the sub-structs,
594 * or directly as just 'ki_filp' in this struct.
600 struct io_poll_iocb poll;
601 struct io_accept accept;
603 struct io_cancel cancel;
604 struct io_timeout timeout;
605 struct io_connect connect;
606 struct io_sr_msg sr_msg;
608 struct io_close close;
609 struct io_files_update files_update;
610 struct io_fadvise fadvise;
611 struct io_madvise madvise;
612 struct io_epoll epoll;
613 struct io_splice splice;
614 struct io_provide_buf pbuf;
617 struct io_async_ctx *io;
619 bool needs_fixed_file;
622 struct io_ring_ctx *ctx;
623 struct list_head list;
626 struct task_struct *task;
632 struct list_head link_list;
634 struct list_head inflight_entry;
636 struct percpu_ref *fixed_file_refs;
640 * Only commands that never go async can use the below fields,
641 * obviously. Right now only IORING_OP_POLL_ADD uses them, and
642 * async armed poll handlers for regular commands. The latter
643 * restore the work, if needed.
646 struct callback_head task_work;
647 struct hlist_node hash_node;
648 struct async_poll *apoll;
650 struct io_wq_work work;
654 #define IO_PLUG_THRESHOLD 2
655 #define IO_IOPOLL_BATCH 8
657 struct io_submit_state {
658 struct blk_plug plug;
661 * io_kiocb alloc cache
663 void *reqs[IO_IOPOLL_BATCH];
664 unsigned int free_reqs;
667 * File reference cache
671 unsigned int has_refs;
672 unsigned int used_refs;
673 unsigned int ios_left;
677 /* needs req->io allocated for deferral/async */
678 unsigned async_ctx : 1;
679 /* needs current->mm setup, does mm access */
680 unsigned needs_mm : 1;
681 /* needs req->file assigned */
682 unsigned needs_file : 1;
683 /* needs req->file assigned IFF fd is >= 0 */
684 unsigned fd_non_neg : 1;
685 /* hash wq insertion if file is a regular file */
686 unsigned hash_reg_file : 1;
687 /* unbound wq insertion if file is a non-regular file */
688 unsigned unbound_nonreg_file : 1;
689 /* opcode is not supported by this kernel */
690 unsigned not_supported : 1;
691 /* needs file table */
692 unsigned file_table : 1;
694 unsigned needs_fs : 1;
695 /* set if opcode supports polled "wait" */
697 unsigned pollout : 1;
698 /* op supports buffer selection */
699 unsigned buffer_select : 1;
702 static const struct io_op_def io_op_defs[] = {
703 [IORING_OP_NOP] = {},
704 [IORING_OP_READV] = {
708 .unbound_nonreg_file = 1,
712 [IORING_OP_WRITEV] = {
717 .unbound_nonreg_file = 1,
720 [IORING_OP_FSYNC] = {
723 [IORING_OP_READ_FIXED] = {
725 .unbound_nonreg_file = 1,
728 [IORING_OP_WRITE_FIXED] = {
731 .unbound_nonreg_file = 1,
734 [IORING_OP_POLL_ADD] = {
736 .unbound_nonreg_file = 1,
738 [IORING_OP_POLL_REMOVE] = {},
739 [IORING_OP_SYNC_FILE_RANGE] = {
742 [IORING_OP_SENDMSG] = {
746 .unbound_nonreg_file = 1,
750 [IORING_OP_RECVMSG] = {
754 .unbound_nonreg_file = 1,
759 [IORING_OP_TIMEOUT] = {
763 [IORING_OP_TIMEOUT_REMOVE] = {},
764 [IORING_OP_ACCEPT] = {
767 .unbound_nonreg_file = 1,
771 [IORING_OP_ASYNC_CANCEL] = {},
772 [IORING_OP_LINK_TIMEOUT] = {
776 [IORING_OP_CONNECT] = {
780 .unbound_nonreg_file = 1,
783 [IORING_OP_FALLOCATE] = {
786 [IORING_OP_OPENAT] = {
792 [IORING_OP_CLOSE] = {
796 [IORING_OP_FILES_UPDATE] = {
800 [IORING_OP_STATX] = {
810 .unbound_nonreg_file = 1,
814 [IORING_OP_WRITE] = {
817 .unbound_nonreg_file = 1,
820 [IORING_OP_FADVISE] = {
823 [IORING_OP_MADVISE] = {
829 .unbound_nonreg_file = 1,
835 .unbound_nonreg_file = 1,
839 [IORING_OP_OPENAT2] = {
845 [IORING_OP_EPOLL_CTL] = {
846 .unbound_nonreg_file = 1,
849 [IORING_OP_SPLICE] = {
852 .unbound_nonreg_file = 1,
854 [IORING_OP_PROVIDE_BUFFERS] = {},
855 [IORING_OP_REMOVE_BUFFERS] = {},
858 static void io_wq_submit_work(struct io_wq_work **workptr);
859 static void io_cqring_fill_event(struct io_kiocb *req, long res);
860 static void io_put_req(struct io_kiocb *req);
861 static void __io_double_put_req(struct io_kiocb *req);
862 static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
863 static void io_queue_linked_timeout(struct io_kiocb *req);
864 static int __io_sqe_files_update(struct io_ring_ctx *ctx,
865 struct io_uring_files_update *ip,
867 static int io_grab_files(struct io_kiocb *req);
868 static void io_cleanup_req(struct io_kiocb *req);
869 static int io_file_get(struct io_submit_state *state, struct io_kiocb *req,
870 int fd, struct file **out_file, bool fixed);
871 static void __io_queue_sqe(struct io_kiocb *req,
872 const struct io_uring_sqe *sqe);
874 static struct kmem_cache *req_cachep;
876 static const struct file_operations io_uring_fops;
878 struct sock *io_uring_get_socket(struct file *file)
880 #if defined(CONFIG_UNIX)
881 if (file->f_op == &io_uring_fops) {
882 struct io_ring_ctx *ctx = file->private_data;
884 return ctx->ring_sock->sk;
889 EXPORT_SYMBOL(io_uring_get_socket);
891 static void io_ring_ctx_ref_free(struct percpu_ref *ref)
893 struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
895 complete(&ctx->completions[0]);
898 static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
900 struct io_ring_ctx *ctx;
903 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
907 ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL);
908 if (!ctx->fallback_req)
911 ctx->completions = kmalloc(2 * sizeof(struct completion), GFP_KERNEL);
912 if (!ctx->completions)
916 * Use 5 bits less than the max cq entries, that should give us around
917 * 32 entries per hash list if totally full and uniformly spread.
919 hash_bits = ilog2(p->cq_entries);
923 ctx->cancel_hash_bits = hash_bits;
924 ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
926 if (!ctx->cancel_hash)
928 __hash_init(ctx->cancel_hash, 1U << hash_bits);
930 if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
931 PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
934 ctx->flags = p->flags;
935 init_waitqueue_head(&ctx->cq_wait);
936 INIT_LIST_HEAD(&ctx->cq_overflow_list);
937 init_completion(&ctx->completions[0]);
938 init_completion(&ctx->completions[1]);
939 idr_init(&ctx->io_buffer_idr);
940 idr_init(&ctx->personality_idr);
941 mutex_init(&ctx->uring_lock);
942 init_waitqueue_head(&ctx->wait);
943 spin_lock_init(&ctx->completion_lock);
944 INIT_LIST_HEAD(&ctx->poll_list);
945 INIT_LIST_HEAD(&ctx->defer_list);
946 INIT_LIST_HEAD(&ctx->timeout_list);
947 init_waitqueue_head(&ctx->inflight_wait);
948 spin_lock_init(&ctx->inflight_lock);
949 INIT_LIST_HEAD(&ctx->inflight_list);
952 if (ctx->fallback_req)
953 kmem_cache_free(req_cachep, ctx->fallback_req);
954 kfree(ctx->completions);
955 kfree(ctx->cancel_hash);
960 static inline bool __req_need_defer(struct io_kiocb *req)
962 struct io_ring_ctx *ctx = req->ctx;
964 return req->sequence != ctx->cached_cq_tail
965 + atomic_read(&ctx->cached_cq_overflow);
968 static inline bool req_need_defer(struct io_kiocb *req)
970 if (unlikely(req->flags & REQ_F_IO_DRAIN))
971 return __req_need_defer(req);
976 static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)
978 struct io_kiocb *req;
980 req = list_first_entry_or_null(&ctx->defer_list, struct io_kiocb, list);
981 if (req && !req_need_defer(req)) {
982 list_del_init(&req->list);
989 static struct io_kiocb *io_get_timeout_req(struct io_ring_ctx *ctx)
991 struct io_kiocb *req;
993 req = list_first_entry_or_null(&ctx->timeout_list, struct io_kiocb, list);
995 if (req->flags & REQ_F_TIMEOUT_NOSEQ)
997 if (!__req_need_defer(req)) {
998 list_del_init(&req->list);
1006 static void __io_commit_cqring(struct io_ring_ctx *ctx)
1008 struct io_rings *rings = ctx->rings;
1010 /* order cqe stores with ring update */
1011 smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
1013 if (wq_has_sleeper(&ctx->cq_wait)) {
1014 wake_up_interruptible(&ctx->cq_wait);
1015 kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
1019 static inline void io_req_work_grab_env(struct io_kiocb *req,
1020 const struct io_op_def *def)
1022 if (!req->work.mm && def->needs_mm) {
1023 mmgrab(current->mm);
1024 req->work.mm = current->mm;
1026 if (!req->work.creds)
1027 req->work.creds = get_current_cred();
1028 if (!req->work.fs && def->needs_fs) {
1029 spin_lock(¤t->fs->lock);
1030 if (!current->fs->in_exec) {
1031 req->work.fs = current->fs;
1032 req->work.fs->users++;
1034 req->work.flags |= IO_WQ_WORK_CANCEL;
1036 spin_unlock(¤t->fs->lock);
1038 if (!req->work.task_pid)
1039 req->work.task_pid = task_pid_vnr(current);
1042 static inline void io_req_work_drop_env(struct io_kiocb *req)
1045 mmdrop(req->work.mm);
1046 req->work.mm = NULL;
1048 if (req->work.creds) {
1049 put_cred(req->work.creds);
1050 req->work.creds = NULL;
1053 struct fs_struct *fs = req->work.fs;
1055 spin_lock(&req->work.fs->lock);
1058 spin_unlock(&req->work.fs->lock);
1064 static inline void io_prep_async_work(struct io_kiocb *req,
1065 struct io_kiocb **link)
1067 const struct io_op_def *def = &io_op_defs[req->opcode];
1069 if (req->flags & REQ_F_ISREG) {
1070 if (def->hash_reg_file)
1071 io_wq_hash_work(&req->work, file_inode(req->file));
1073 if (def->unbound_nonreg_file)
1074 req->work.flags |= IO_WQ_WORK_UNBOUND;
1077 io_req_work_grab_env(req, def);
1079 *link = io_prep_linked_timeout(req);
1082 static inline void io_queue_async_work(struct io_kiocb *req)
1084 struct io_ring_ctx *ctx = req->ctx;
1085 struct io_kiocb *link;
1087 io_prep_async_work(req, &link);
1089 trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
1090 &req->work, req->flags);
1091 io_wq_enqueue(ctx->io_wq, &req->work);
1094 io_queue_linked_timeout(link);
1097 static void io_kill_timeout(struct io_kiocb *req)
1101 ret = hrtimer_try_to_cancel(&req->io->timeout.timer);
1103 atomic_inc(&req->ctx->cq_timeouts);
1104 list_del_init(&req->list);
1105 req->flags |= REQ_F_COMP_LOCKED;
1106 io_cqring_fill_event(req, 0);
1111 static void io_kill_timeouts(struct io_ring_ctx *ctx)
1113 struct io_kiocb *req, *tmp;
1115 spin_lock_irq(&ctx->completion_lock);
1116 list_for_each_entry_safe(req, tmp, &ctx->timeout_list, list)
1117 io_kill_timeout(req);
1118 spin_unlock_irq(&ctx->completion_lock);
1121 static void io_commit_cqring(struct io_ring_ctx *ctx)
1123 struct io_kiocb *req;
1125 while ((req = io_get_timeout_req(ctx)) != NULL)
1126 io_kill_timeout(req);
1128 __io_commit_cqring(ctx);
1130 while ((req = io_get_deferred_req(ctx)) != NULL)
1131 io_queue_async_work(req);
1134 static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
1136 struct io_rings *rings = ctx->rings;
1139 tail = ctx->cached_cq_tail;
1141 * writes to the cq entry need to come after reading head; the
1142 * control dependency is enough as we're using WRITE_ONCE to
1145 if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
1148 ctx->cached_cq_tail++;
1149 return &rings->cqes[tail & ctx->cq_mask];
1152 static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
1156 if (!ctx->eventfd_async)
1158 return io_wq_current_is_worker();
1161 static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
1163 if (waitqueue_active(&ctx->wait))
1164 wake_up(&ctx->wait);
1165 if (waitqueue_active(&ctx->sqo_wait))
1166 wake_up(&ctx->sqo_wait);
1167 if (io_should_trigger_evfd(ctx))
1168 eventfd_signal(ctx->cq_ev_fd, 1);
1171 /* Returns true if there are no backlogged entries after the flush */
1172 static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
1174 struct io_rings *rings = ctx->rings;
1175 struct io_uring_cqe *cqe;
1176 struct io_kiocb *req;
1177 unsigned long flags;
1181 if (list_empty_careful(&ctx->cq_overflow_list))
1183 if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) ==
1184 rings->cq_ring_entries))
1188 spin_lock_irqsave(&ctx->completion_lock, flags);
1190 /* if force is set, the ring is going away. always drop after that */
1192 ctx->cq_overflow_flushed = 1;
1195 while (!list_empty(&ctx->cq_overflow_list)) {
1196 cqe = io_get_cqring(ctx);
1200 req = list_first_entry(&ctx->cq_overflow_list, struct io_kiocb,
1202 list_move(&req->list, &list);
1203 req->flags &= ~REQ_F_OVERFLOW;
1205 WRITE_ONCE(cqe->user_data, req->user_data);
1206 WRITE_ONCE(cqe->res, req->result);
1207 WRITE_ONCE(cqe->flags, req->cflags);
1209 WRITE_ONCE(ctx->rings->cq_overflow,
1210 atomic_inc_return(&ctx->cached_cq_overflow));
1214 io_commit_cqring(ctx);
1216 clear_bit(0, &ctx->sq_check_overflow);
1217 clear_bit(0, &ctx->cq_check_overflow);
1219 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1220 io_cqring_ev_posted(ctx);
1222 while (!list_empty(&list)) {
1223 req = list_first_entry(&list, struct io_kiocb, list);
1224 list_del(&req->list);
1231 static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags)
1233 struct io_ring_ctx *ctx = req->ctx;
1234 struct io_uring_cqe *cqe;
1236 trace_io_uring_complete(ctx, req->user_data, res);
1239 * If we can't get a cq entry, userspace overflowed the
1240 * submission (by quite a lot). Increment the overflow count in
1243 cqe = io_get_cqring(ctx);
1245 WRITE_ONCE(cqe->user_data, req->user_data);
1246 WRITE_ONCE(cqe->res, res);
1247 WRITE_ONCE(cqe->flags, cflags);
1248 } else if (ctx->cq_overflow_flushed) {
1249 WRITE_ONCE(ctx->rings->cq_overflow,
1250 atomic_inc_return(&ctx->cached_cq_overflow));
1252 if (list_empty(&ctx->cq_overflow_list)) {
1253 set_bit(0, &ctx->sq_check_overflow);
1254 set_bit(0, &ctx->cq_check_overflow);
1256 req->flags |= REQ_F_OVERFLOW;
1257 refcount_inc(&req->refs);
1259 req->cflags = cflags;
1260 list_add_tail(&req->list, &ctx->cq_overflow_list);
1264 static void io_cqring_fill_event(struct io_kiocb *req, long res)
1266 __io_cqring_fill_event(req, res, 0);
1269 static void __io_cqring_add_event(struct io_kiocb *req, long res, long cflags)
1271 struct io_ring_ctx *ctx = req->ctx;
1272 unsigned long flags;
1274 spin_lock_irqsave(&ctx->completion_lock, flags);
1275 __io_cqring_fill_event(req, res, cflags);
1276 io_commit_cqring(ctx);
1277 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1279 io_cqring_ev_posted(ctx);
1282 static void io_cqring_add_event(struct io_kiocb *req, long res)
1284 __io_cqring_add_event(req, res, 0);
1287 static inline bool io_is_fallback_req(struct io_kiocb *req)
1289 return req == (struct io_kiocb *)
1290 ((unsigned long) req->ctx->fallback_req & ~1UL);
1293 static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx)
1295 struct io_kiocb *req;
1297 req = ctx->fallback_req;
1298 if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req))
1304 static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx,
1305 struct io_submit_state *state)
1307 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
1308 struct io_kiocb *req;
1311 req = kmem_cache_alloc(req_cachep, gfp);
1314 } else if (!state->free_reqs) {
1318 sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs));
1319 ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs);
1322 * Bulk alloc is all-or-nothing. If we fail to get a batch,
1323 * retry single alloc to be on the safe side.
1325 if (unlikely(ret <= 0)) {
1326 state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
1327 if (!state->reqs[0])
1331 state->free_reqs = ret - 1;
1332 req = state->reqs[ret - 1];
1335 req = state->reqs[state->free_reqs];
1340 return io_get_fallback_req(ctx);
1343 static inline void io_put_file(struct io_kiocb *req, struct file *file,
1347 percpu_ref_put(req->fixed_file_refs);
1352 static void __io_req_aux_free(struct io_kiocb *req)
1354 if (req->flags & REQ_F_NEED_CLEANUP)
1355 io_cleanup_req(req);
1359 io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE));
1361 put_task_struct(req->task);
1363 io_req_work_drop_env(req);
1366 static void __io_free_req(struct io_kiocb *req)
1368 __io_req_aux_free(req);
1370 if (req->flags & REQ_F_INFLIGHT) {
1371 struct io_ring_ctx *ctx = req->ctx;
1372 unsigned long flags;
1374 spin_lock_irqsave(&ctx->inflight_lock, flags);
1375 list_del(&req->inflight_entry);
1376 if (waitqueue_active(&ctx->inflight_wait))
1377 wake_up(&ctx->inflight_wait);
1378 spin_unlock_irqrestore(&ctx->inflight_lock, flags);
1381 percpu_ref_put(&req->ctx->refs);
1382 if (likely(!io_is_fallback_req(req)))
1383 kmem_cache_free(req_cachep, req);
1385 clear_bit_unlock(0, (unsigned long *) &req->ctx->fallback_req);
1389 void *reqs[IO_IOPOLL_BATCH];
1394 static void io_free_req_many(struct io_ring_ctx *ctx, struct req_batch *rb)
1398 if (rb->need_iter) {
1399 int i, inflight = 0;
1400 unsigned long flags;
1402 for (i = 0; i < rb->to_free; i++) {
1403 struct io_kiocb *req = rb->reqs[i];
1405 if (req->flags & REQ_F_FIXED_FILE) {
1407 percpu_ref_put(req->fixed_file_refs);
1409 if (req->flags & REQ_F_INFLIGHT)
1411 __io_req_aux_free(req);
1416 spin_lock_irqsave(&ctx->inflight_lock, flags);
1417 for (i = 0; i < rb->to_free; i++) {
1418 struct io_kiocb *req = rb->reqs[i];
1420 if (req->flags & REQ_F_INFLIGHT) {
1421 list_del(&req->inflight_entry);
1426 spin_unlock_irqrestore(&ctx->inflight_lock, flags);
1428 if (waitqueue_active(&ctx->inflight_wait))
1429 wake_up(&ctx->inflight_wait);
1432 kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs);
1433 percpu_ref_put_many(&ctx->refs, rb->to_free);
1434 rb->to_free = rb->need_iter = 0;
1437 static bool io_link_cancel_timeout(struct io_kiocb *req)
1439 struct io_ring_ctx *ctx = req->ctx;
1442 ret = hrtimer_try_to_cancel(&req->io->timeout.timer);
1444 io_cqring_fill_event(req, -ECANCELED);
1445 io_commit_cqring(ctx);
1446 req->flags &= ~REQ_F_LINK_HEAD;
1454 static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr)
1456 struct io_ring_ctx *ctx = req->ctx;
1457 bool wake_ev = false;
1459 /* Already got next link */
1460 if (req->flags & REQ_F_LINK_NEXT)
1464 * The list should never be empty when we are called here. But could
1465 * potentially happen if the chain is messed up, check to be on the
1468 while (!list_empty(&req->link_list)) {
1469 struct io_kiocb *nxt = list_first_entry(&req->link_list,
1470 struct io_kiocb, link_list);
1472 if (unlikely((req->flags & REQ_F_LINK_TIMEOUT) &&
1473 (nxt->flags & REQ_F_TIMEOUT))) {
1474 list_del_init(&nxt->link_list);
1475 wake_ev |= io_link_cancel_timeout(nxt);
1476 req->flags &= ~REQ_F_LINK_TIMEOUT;
1480 list_del_init(&req->link_list);
1481 if (!list_empty(&nxt->link_list))
1482 nxt->flags |= REQ_F_LINK_HEAD;
1487 req->flags |= REQ_F_LINK_NEXT;
1489 io_cqring_ev_posted(ctx);
1493 * Called if REQ_F_LINK_HEAD is set, and we fail the head request
1495 static void io_fail_links(struct io_kiocb *req)
1497 struct io_ring_ctx *ctx = req->ctx;
1498 unsigned long flags;
1500 spin_lock_irqsave(&ctx->completion_lock, flags);
1502 while (!list_empty(&req->link_list)) {
1503 struct io_kiocb *link = list_first_entry(&req->link_list,
1504 struct io_kiocb, link_list);
1506 list_del_init(&link->link_list);
1507 trace_io_uring_fail_link(req, link);
1509 if ((req->flags & REQ_F_LINK_TIMEOUT) &&
1510 link->opcode == IORING_OP_LINK_TIMEOUT) {
1511 io_link_cancel_timeout(link);
1513 io_cqring_fill_event(link, -ECANCELED);
1514 __io_double_put_req(link);
1516 req->flags &= ~REQ_F_LINK_TIMEOUT;
1519 io_commit_cqring(ctx);
1520 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1521 io_cqring_ev_posted(ctx);
1524 static void io_req_find_next(struct io_kiocb *req, struct io_kiocb **nxt)
1526 if (likely(!(req->flags & REQ_F_LINK_HEAD)))
1530 * If LINK is set, we have dependent requests in this chain. If we
1531 * didn't fail this request, queue the first one up, moving any other
1532 * dependencies to the next request. In case of failure, fail the rest
1535 if (req->flags & REQ_F_FAIL_LINK) {
1537 } else if ((req->flags & (REQ_F_LINK_TIMEOUT | REQ_F_COMP_LOCKED)) ==
1538 REQ_F_LINK_TIMEOUT) {
1539 struct io_ring_ctx *ctx = req->ctx;
1540 unsigned long flags;
1543 * If this is a timeout link, we could be racing with the
1544 * timeout timer. Grab the completion lock for this case to
1545 * protect against that.
1547 spin_lock_irqsave(&ctx->completion_lock, flags);
1548 io_req_link_next(req, nxt);
1549 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1551 io_req_link_next(req, nxt);
1555 static void io_free_req(struct io_kiocb *req)
1557 struct io_kiocb *nxt = NULL;
1559 io_req_find_next(req, &nxt);
1563 io_queue_async_work(nxt);
1566 static void io_link_work_cb(struct io_wq_work **workptr)
1568 struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
1569 struct io_kiocb *link;
1571 link = list_first_entry(&req->link_list, struct io_kiocb, link_list);
1572 io_queue_linked_timeout(link);
1573 io_wq_submit_work(workptr);
1576 static void io_wq_assign_next(struct io_wq_work **workptr, struct io_kiocb *nxt)
1578 struct io_kiocb *link;
1579 const struct io_op_def *def = &io_op_defs[nxt->opcode];
1581 if ((nxt->flags & REQ_F_ISREG) && def->hash_reg_file)
1582 io_wq_hash_work(&nxt->work, file_inode(nxt->file));
1584 *workptr = &nxt->work;
1585 link = io_prep_linked_timeout(nxt);
1587 nxt->work.func = io_link_work_cb;
1591 * Drop reference to request, return next in chain (if there is one) if this
1592 * was the last reference to this request.
1594 __attribute__((nonnull))
1595 static void io_put_req_find_next(struct io_kiocb *req, struct io_kiocb **nxtptr)
1597 if (refcount_dec_and_test(&req->refs)) {
1598 io_req_find_next(req, nxtptr);
1603 static void io_put_req(struct io_kiocb *req)
1605 if (refcount_dec_and_test(&req->refs))
1609 static void io_steal_work(struct io_kiocb *req,
1610 struct io_wq_work **workptr)
1613 * It's in an io-wq worker, so there always should be at least
1614 * one reference, which will be dropped in io_put_work() just
1615 * after the current handler returns.
1617 * It also means, that if the counter dropped to 1, then there is
1618 * no asynchronous users left, so it's safe to steal the next work.
1620 if (refcount_read(&req->refs) == 1) {
1621 struct io_kiocb *nxt = NULL;
1623 io_req_find_next(req, &nxt);
1625 io_wq_assign_next(workptr, nxt);
1630 * Must only be used if we don't need to care about links, usually from
1631 * within the completion handling itself.
1633 static void __io_double_put_req(struct io_kiocb *req)
1635 /* drop both submit and complete references */
1636 if (refcount_sub_and_test(2, &req->refs))
1640 static void io_double_put_req(struct io_kiocb *req)
1642 /* drop both submit and complete references */
1643 if (refcount_sub_and_test(2, &req->refs))
1647 static unsigned io_cqring_events(struct io_ring_ctx *ctx, bool noflush)
1649 struct io_rings *rings = ctx->rings;
1651 if (test_bit(0, &ctx->cq_check_overflow)) {
1653 * noflush == true is from the waitqueue handler, just ensure
1654 * we wake up the task, and the next invocation will flush the
1655 * entries. We cannot safely to it from here.
1657 if (noflush && !list_empty(&ctx->cq_overflow_list))
1660 io_cqring_overflow_flush(ctx, false);
1663 /* See comment at the top of this file */
1665 return ctx->cached_cq_tail - READ_ONCE(rings->cq.head);
1668 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
1670 struct io_rings *rings = ctx->rings;
1672 /* make sure SQ entry isn't read before tail */
1673 return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
1676 static inline bool io_req_multi_free(struct req_batch *rb, struct io_kiocb *req)
1678 if ((req->flags & REQ_F_LINK_HEAD) || io_is_fallback_req(req))
1681 if (!(req->flags & REQ_F_FIXED_FILE) || req->io)
1684 rb->reqs[rb->to_free++] = req;
1685 if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs)))
1686 io_free_req_many(req->ctx, rb);
1690 static int io_put_kbuf(struct io_kiocb *req)
1692 struct io_buffer *kbuf;
1695 kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
1696 cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
1697 cflags |= IORING_CQE_F_BUFFER;
1704 * Find and free completed poll iocbs
1706 static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
1707 struct list_head *done)
1709 struct req_batch rb;
1710 struct io_kiocb *req;
1712 rb.to_free = rb.need_iter = 0;
1713 while (!list_empty(done)) {
1716 req = list_first_entry(done, struct io_kiocb, list);
1717 list_del(&req->list);
1719 if (req->flags & REQ_F_BUFFER_SELECTED)
1720 cflags = io_put_kbuf(req);
1722 __io_cqring_fill_event(req, req->result, cflags);
1725 if (refcount_dec_and_test(&req->refs) &&
1726 !io_req_multi_free(&rb, req))
1730 io_commit_cqring(ctx);
1731 if (ctx->flags & IORING_SETUP_SQPOLL)
1732 io_cqring_ev_posted(ctx);
1733 io_free_req_many(ctx, &rb);
1736 static void io_iopoll_queue(struct list_head *again)
1738 struct io_kiocb *req;
1741 req = list_first_entry(again, struct io_kiocb, list);
1742 list_del(&req->list);
1743 refcount_inc(&req->refs);
1744 io_queue_async_work(req);
1745 } while (!list_empty(again));
1748 static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
1751 struct io_kiocb *req, *tmp;
1758 * Only spin for completions if we don't have multiple devices hanging
1759 * off our complete list, and we're under the requested amount.
1761 spin = !ctx->poll_multi_file && *nr_events < min;
1764 list_for_each_entry_safe(req, tmp, &ctx->poll_list, list) {
1765 struct kiocb *kiocb = &req->rw.kiocb;
1768 * Move completed and retryable entries to our local lists.
1769 * If we find a request that requires polling, break out
1770 * and complete those lists first, if we have entries there.
1772 if (req->flags & REQ_F_IOPOLL_COMPLETED) {
1773 list_move_tail(&req->list, &done);
1776 if (!list_empty(&done))
1779 if (req->result == -EAGAIN) {
1780 list_move_tail(&req->list, &again);
1783 if (!list_empty(&again))
1786 ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
1795 if (!list_empty(&done))
1796 io_iopoll_complete(ctx, nr_events, &done);
1798 if (!list_empty(&again))
1799 io_iopoll_queue(&again);
1805 * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a
1806 * non-spinning poll check - we'll still enter the driver poll loop, but only
1807 * as a non-spinning completion check.
1809 static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events,
1812 while (!list_empty(&ctx->poll_list) && !need_resched()) {
1815 ret = io_do_iopoll(ctx, nr_events, min);
1818 if (!min || *nr_events >= min)
1826 * We can't just wait for polled events to come to us, we have to actively
1827 * find and complete them.
1829 static void io_iopoll_reap_events(struct io_ring_ctx *ctx)
1831 if (!(ctx->flags & IORING_SETUP_IOPOLL))
1834 mutex_lock(&ctx->uring_lock);
1835 while (!list_empty(&ctx->poll_list)) {
1836 unsigned int nr_events = 0;
1838 io_iopoll_getevents(ctx, &nr_events, 1);
1841 * Ensure we allow local-to-the-cpu processing to take place,
1842 * in this case we need to ensure that we reap all events.
1846 mutex_unlock(&ctx->uring_lock);
1849 static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events,
1852 int iters = 0, ret = 0;
1855 * We disallow the app entering submit/complete with polling, but we
1856 * still need to lock the ring to prevent racing with polled issue
1857 * that got punted to a workqueue.
1859 mutex_lock(&ctx->uring_lock);
1864 * Don't enter poll loop if we already have events pending.
1865 * If we do, we can potentially be spinning for commands that
1866 * already triggered a CQE (eg in error).
1868 if (io_cqring_events(ctx, false))
1872 * If a submit got punted to a workqueue, we can have the
1873 * application entering polling for a command before it gets
1874 * issued. That app will hold the uring_lock for the duration
1875 * of the poll right here, so we need to take a breather every
1876 * now and then to ensure that the issue has a chance to add
1877 * the poll to the issued list. Otherwise we can spin here
1878 * forever, while the workqueue is stuck trying to acquire the
1881 if (!(++iters & 7)) {
1882 mutex_unlock(&ctx->uring_lock);
1883 mutex_lock(&ctx->uring_lock);
1886 if (*nr_events < min)
1887 tmin = min - *nr_events;
1889 ret = io_iopoll_getevents(ctx, nr_events, tmin);
1893 } while (min && !*nr_events && !need_resched());
1895 mutex_unlock(&ctx->uring_lock);
1899 static void kiocb_end_write(struct io_kiocb *req)
1902 * Tell lockdep we inherited freeze protection from submission
1905 if (req->flags & REQ_F_ISREG) {
1906 struct inode *inode = file_inode(req->file);
1908 __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
1910 file_end_write(req->file);
1913 static inline void req_set_fail_links(struct io_kiocb *req)
1915 if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK)
1916 req->flags |= REQ_F_FAIL_LINK;
1919 static void io_complete_rw_common(struct kiocb *kiocb, long res)
1921 struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
1924 if (kiocb->ki_flags & IOCB_WRITE)
1925 kiocb_end_write(req);
1927 if (res != req->result)
1928 req_set_fail_links(req);
1929 if (req->flags & REQ_F_BUFFER_SELECTED)
1930 cflags = io_put_kbuf(req);
1931 __io_cqring_add_event(req, res, cflags);
1934 static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
1936 struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
1938 io_complete_rw_common(kiocb, res);
1942 static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
1944 struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
1946 if (kiocb->ki_flags & IOCB_WRITE)
1947 kiocb_end_write(req);
1949 if (res != req->result)
1950 req_set_fail_links(req);
1953 req->flags |= REQ_F_IOPOLL_COMPLETED;
1957 * After the iocb has been issued, it's safe to be found on the poll list.
1958 * Adding the kiocb to the list AFTER submission ensures that we don't
1959 * find it from a io_iopoll_getevents() thread before the issuer is done
1960 * accessing the kiocb cookie.
1962 static void io_iopoll_req_issued(struct io_kiocb *req)
1964 struct io_ring_ctx *ctx = req->ctx;
1967 * Track whether we have multiple files in our lists. This will impact
1968 * how we do polling eventually, not spinning if we're on potentially
1969 * different devices.
1971 if (list_empty(&ctx->poll_list)) {
1972 ctx->poll_multi_file = false;
1973 } else if (!ctx->poll_multi_file) {
1974 struct io_kiocb *list_req;
1976 list_req = list_first_entry(&ctx->poll_list, struct io_kiocb,
1978 if (list_req->file != req->file)
1979 ctx->poll_multi_file = true;
1983 * For fast devices, IO may have already completed. If it has, add
1984 * it to the front so we find it first.
1986 if (req->flags & REQ_F_IOPOLL_COMPLETED)
1987 list_add(&req->list, &ctx->poll_list);
1989 list_add_tail(&req->list, &ctx->poll_list);
1991 if ((ctx->flags & IORING_SETUP_SQPOLL) &&
1992 wq_has_sleeper(&ctx->sqo_wait))
1993 wake_up(&ctx->sqo_wait);
1996 static void io_file_put(struct io_submit_state *state)
1999 int diff = state->has_refs - state->used_refs;
2002 fput_many(state->file, diff);
2008 * Get as many references to a file as we have IOs left in this submission,
2009 * assuming most submissions are for one file, or at least that each file
2010 * has more than one submission.
2012 static struct file *__io_file_get(struct io_submit_state *state, int fd)
2018 if (state->fd == fd) {
2025 state->file = fget_many(fd, state->ios_left);
2030 state->has_refs = state->ios_left;
2031 state->used_refs = 1;
2037 * If we tracked the file through the SCM inflight mechanism, we could support
2038 * any file. For now, just ensure that anything potentially problematic is done
2041 static bool io_file_supports_async(struct file *file, int rw)
2043 umode_t mode = file_inode(file)->i_mode;
2045 if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISSOCK(mode))
2047 if (S_ISREG(mode) && file->f_op != &io_uring_fops)
2050 if (!(file->f_mode & FMODE_NOWAIT))
2054 return file->f_op->read_iter != NULL;
2056 return file->f_op->write_iter != NULL;
2059 static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
2060 bool force_nonblock)
2062 struct io_ring_ctx *ctx = req->ctx;
2063 struct kiocb *kiocb = &req->rw.kiocb;
2067 if (S_ISREG(file_inode(req->file)->i_mode))
2068 req->flags |= REQ_F_ISREG;
2070 kiocb->ki_pos = READ_ONCE(sqe->off);
2071 if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) {
2072 req->flags |= REQ_F_CUR_POS;
2073 kiocb->ki_pos = req->file->f_pos;
2075 kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
2076 kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
2077 ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
2081 ioprio = READ_ONCE(sqe->ioprio);
2083 ret = ioprio_check_cap(ioprio);
2087 kiocb->ki_ioprio = ioprio;
2089 kiocb->ki_ioprio = get_current_ioprio();
2091 /* don't allow async punt if RWF_NOWAIT was requested */
2092 if ((kiocb->ki_flags & IOCB_NOWAIT) ||
2093 (req->file->f_flags & O_NONBLOCK))
2094 req->flags |= REQ_F_NOWAIT;
2097 kiocb->ki_flags |= IOCB_NOWAIT;
2099 if (ctx->flags & IORING_SETUP_IOPOLL) {
2100 if (!(kiocb->ki_flags & IOCB_DIRECT) ||
2101 !kiocb->ki_filp->f_op->iopoll)
2104 kiocb->ki_flags |= IOCB_HIPRI;
2105 kiocb->ki_complete = io_complete_rw_iopoll;
2108 if (kiocb->ki_flags & IOCB_HIPRI)
2110 kiocb->ki_complete = io_complete_rw;
2113 req->rw.addr = READ_ONCE(sqe->addr);
2114 req->rw.len = READ_ONCE(sqe->len);
2115 /* we own ->private, reuse it for the buffer index / buffer ID */
2116 req->rw.kiocb.private = (void *) (unsigned long)
2117 READ_ONCE(sqe->buf_index);
2121 static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
2127 case -ERESTARTNOINTR:
2128 case -ERESTARTNOHAND:
2129 case -ERESTART_RESTARTBLOCK:
2131 * We can't just restart the syscall, since previously
2132 * submitted sqes may already be in progress. Just fail this
2138 kiocb->ki_complete(kiocb, ret, 0);
2142 static void kiocb_done(struct kiocb *kiocb, ssize_t ret)
2144 struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
2146 if (req->flags & REQ_F_CUR_POS)
2147 req->file->f_pos = kiocb->ki_pos;
2148 if (ret >= 0 && kiocb->ki_complete == io_complete_rw)
2149 io_complete_rw(kiocb, ret, 0);
2151 io_rw_done(kiocb, ret);
2154 static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
2155 struct iov_iter *iter)
2157 struct io_ring_ctx *ctx = req->ctx;
2158 size_t len = req->rw.len;
2159 struct io_mapped_ubuf *imu;
2160 unsigned index, buf_index;
2164 /* attempt to use fixed buffers without having provided iovecs */
2165 if (unlikely(!ctx->user_bufs))
2168 buf_index = (unsigned long) req->rw.kiocb.private;
2169 if (unlikely(buf_index >= ctx->nr_user_bufs))
2172 index = array_index_nospec(buf_index, ctx->nr_user_bufs);
2173 imu = &ctx->user_bufs[index];
2174 buf_addr = req->rw.addr;
2177 if (buf_addr + len < buf_addr)
2179 /* not inside the mapped region */
2180 if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len)
2184 * May not be a start of buffer, set size appropriately
2185 * and advance us to the beginning.
2187 offset = buf_addr - imu->ubuf;
2188 iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
2192 * Don't use iov_iter_advance() here, as it's really slow for
2193 * using the latter parts of a big fixed buffer - it iterates
2194 * over each segment manually. We can cheat a bit here, because
2197 * 1) it's a BVEC iter, we set it up
2198 * 2) all bvecs are PAGE_SIZE in size, except potentially the
2199 * first and last bvec
2201 * So just find our index, and adjust the iterator afterwards.
2202 * If the offset is within the first bvec (or the whole first
2203 * bvec, just use iov_iter_advance(). This makes it easier
2204 * since we can just skip the first segment, which may not
2205 * be PAGE_SIZE aligned.
2207 const struct bio_vec *bvec = imu->bvec;
2209 if (offset <= bvec->bv_len) {
2210 iov_iter_advance(iter, offset);
2212 unsigned long seg_skip;
2214 /* skip first vec */
2215 offset -= bvec->bv_len;
2216 seg_skip = 1 + (offset >> PAGE_SHIFT);
2218 iter->bvec = bvec + seg_skip;
2219 iter->nr_segs -= seg_skip;
2220 iter->count -= bvec->bv_len + offset;
2221 iter->iov_offset = offset & ~PAGE_MASK;
2228 static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
2231 mutex_unlock(&ctx->uring_lock);
2234 static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
2237 * "Normal" inline submissions always hold the uring_lock, since we
2238 * grab it from the system call. Same is true for the SQPOLL offload.
2239 * The only exception is when we've detached the request and issue it
2240 * from an async worker thread, grab the lock for that case.
2243 mutex_lock(&ctx->uring_lock);
2246 static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
2247 int bgid, struct io_buffer *kbuf,
2250 struct io_buffer *head;
2252 if (req->flags & REQ_F_BUFFER_SELECTED)
2255 io_ring_submit_lock(req->ctx, needs_lock);
2257 lockdep_assert_held(&req->ctx->uring_lock);
2259 head = idr_find(&req->ctx->io_buffer_idr, bgid);
2261 if (!list_empty(&head->list)) {
2262 kbuf = list_last_entry(&head->list, struct io_buffer,
2264 list_del(&kbuf->list);
2267 idr_remove(&req->ctx->io_buffer_idr, bgid);
2269 if (*len > kbuf->len)
2272 kbuf = ERR_PTR(-ENOBUFS);
2275 io_ring_submit_unlock(req->ctx, needs_lock);
2280 static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
2283 struct io_buffer *kbuf;
2286 kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
2287 bgid = (int) (unsigned long) req->rw.kiocb.private;
2288 kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
2291 req->rw.addr = (u64) (unsigned long) kbuf;
2292 req->flags |= REQ_F_BUFFER_SELECTED;
2293 return u64_to_user_ptr(kbuf->addr);
2296 #ifdef CONFIG_COMPAT
2297 static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
2300 struct compat_iovec __user *uiov;
2301 compat_ssize_t clen;
2305 uiov = u64_to_user_ptr(req->rw.addr);
2306 if (!access_ok(uiov, sizeof(*uiov)))
2308 if (__get_user(clen, &uiov->iov_len))
2314 buf = io_rw_buffer_select(req, &len, needs_lock);
2316 return PTR_ERR(buf);
2317 iov[0].iov_base = buf;
2318 iov[0].iov_len = (compat_size_t) len;
2323 static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
2326 struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
2330 if (copy_from_user(iov, uiov, sizeof(*uiov)))
2333 len = iov[0].iov_len;
2336 buf = io_rw_buffer_select(req, &len, needs_lock);
2338 return PTR_ERR(buf);
2339 iov[0].iov_base = buf;
2340 iov[0].iov_len = len;
2344 static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
2347 if (req->flags & REQ_F_BUFFER_SELECTED)
2351 else if (req->rw.len > 1)
2354 #ifdef CONFIG_COMPAT
2355 if (req->ctx->compat)
2356 return io_compat_import(req, iov, needs_lock);
2359 return __io_iov_buffer_select(req, iov, needs_lock);
2362 static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
2363 struct iovec **iovec, struct iov_iter *iter,
2366 void __user *buf = u64_to_user_ptr(req->rw.addr);
2367 size_t sqe_len = req->rw.len;
2371 opcode = req->opcode;
2372 if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
2374 return io_import_fixed(req, rw, iter);
2377 /* buffer index only valid with fixed read/write, or buffer select */
2378 if (req->rw.kiocb.private && !(req->flags & REQ_F_BUFFER_SELECT))
2381 if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
2382 if (req->flags & REQ_F_BUFFER_SELECT) {
2383 buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
2386 return PTR_ERR(buf);
2388 req->rw.len = sqe_len;
2391 ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
2393 return ret < 0 ? ret : sqe_len;
2397 struct io_async_rw *iorw = &req->io->rw;
2400 iov_iter_init(iter, rw, *iovec, iorw->nr_segs, iorw->size);
2401 if (iorw->iov == iorw->fast_iov)
2406 if (req->flags & REQ_F_BUFFER_SELECT) {
2407 ret = io_iov_buffer_select(req, *iovec, needs_lock);
2409 ret = (*iovec)->iov_len;
2410 iov_iter_init(iter, rw, *iovec, 1, ret);
2416 #ifdef CONFIG_COMPAT
2417 if (req->ctx->compat)
2418 return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
2422 return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter);
2426 * For files that don't have ->read_iter() and ->write_iter(), handle them
2427 * by looping over ->read() or ->write() manually.
2429 static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb,
2430 struct iov_iter *iter)
2435 * Don't support polled IO through this interface, and we can't
2436 * support non-blocking either. For the latter, this just causes
2437 * the kiocb to be handled from an async context.
2439 if (kiocb->ki_flags & IOCB_HIPRI)
2441 if (kiocb->ki_flags & IOCB_NOWAIT)
2444 while (iov_iter_count(iter)) {
2448 if (!iov_iter_is_bvec(iter)) {
2449 iovec = iov_iter_iovec(iter);
2451 /* fixed buffers import bvec */
2452 iovec.iov_base = kmap(iter->bvec->bv_page)
2454 iovec.iov_len = min(iter->count,
2455 iter->bvec->bv_len - iter->iov_offset);
2459 nr = file->f_op->read(file, iovec.iov_base,
2460 iovec.iov_len, &kiocb->ki_pos);
2462 nr = file->f_op->write(file, iovec.iov_base,
2463 iovec.iov_len, &kiocb->ki_pos);
2466 if (iov_iter_is_bvec(iter))
2467 kunmap(iter->bvec->bv_page);
2475 if (nr != iovec.iov_len)
2477 iov_iter_advance(iter, nr);
2483 static void io_req_map_rw(struct io_kiocb *req, ssize_t io_size,
2484 struct iovec *iovec, struct iovec *fast_iov,
2485 struct iov_iter *iter)
2487 req->io->rw.nr_segs = iter->nr_segs;
2488 req->io->rw.size = io_size;
2489 req->io->rw.iov = iovec;
2490 if (!req->io->rw.iov) {
2491 req->io->rw.iov = req->io->rw.fast_iov;
2492 if (req->io->rw.iov != fast_iov)
2493 memcpy(req->io->rw.iov, fast_iov,
2494 sizeof(struct iovec) * iter->nr_segs);
2496 req->flags |= REQ_F_NEED_CLEANUP;
2500 static inline int __io_alloc_async_ctx(struct io_kiocb *req)
2502 req->io = kmalloc(sizeof(*req->io), GFP_KERNEL);
2503 return req->io == NULL;
2506 static int io_alloc_async_ctx(struct io_kiocb *req)
2508 if (!io_op_defs[req->opcode].async_ctx)
2511 return __io_alloc_async_ctx(req);
2514 static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size,
2515 struct iovec *iovec, struct iovec *fast_iov,
2516 struct iov_iter *iter)
2518 if (!io_op_defs[req->opcode].async_ctx)
2521 if (__io_alloc_async_ctx(req))
2524 io_req_map_rw(req, io_size, iovec, fast_iov, iter);
2529 static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
2530 bool force_nonblock)
2532 struct io_async_ctx *io;
2533 struct iov_iter iter;
2536 ret = io_prep_rw(req, sqe, force_nonblock);
2540 if (unlikely(!(req->file->f_mode & FMODE_READ)))
2543 /* either don't need iovec imported or already have it */
2544 if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
2548 io->rw.iov = io->rw.fast_iov;
2550 ret = io_import_iovec(READ, req, &io->rw.iov, &iter, !force_nonblock);
2555 io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter);
2559 static int io_read(struct io_kiocb *req, bool force_nonblock)
2561 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
2562 struct kiocb *kiocb = &req->rw.kiocb;
2563 struct iov_iter iter;
2565 ssize_t io_size, ret;
2567 ret = io_import_iovec(READ, req, &iovec, &iter, !force_nonblock);
2571 /* Ensure we clear previously set non-block flag */
2572 if (!force_nonblock)
2573 kiocb->ki_flags &= ~IOCB_NOWAIT;
2577 if (req->flags & REQ_F_LINK_HEAD)
2578 req->result = io_size;
2581 * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
2582 * we know to async punt it even if it was opened O_NONBLOCK
2584 if (force_nonblock && !io_file_supports_async(req->file, READ))
2587 iov_count = iov_iter_count(&iter);
2588 ret = rw_verify_area(READ, req->file, &kiocb->ki_pos, iov_count);
2592 if (req->file->f_op->read_iter)
2593 ret2 = call_read_iter(req->file, kiocb, &iter);
2595 ret2 = loop_rw_iter(READ, req->file, kiocb, &iter);
2597 /* Catch -EAGAIN return for forced non-blocking submission */
2598 if (!force_nonblock || ret2 != -EAGAIN) {
2599 kiocb_done(kiocb, ret2);
2602 ret = io_setup_async_rw(req, io_size, iovec,
2603 inline_vecs, &iter);
2606 /* any defer here is final, must blocking retry */
2607 if (!(req->flags & REQ_F_NOWAIT) &&
2608 !file_can_poll(req->file))
2609 req->flags |= REQ_F_MUST_PUNT;
2615 req->flags &= ~REQ_F_NEED_CLEANUP;
2619 static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
2620 bool force_nonblock)
2622 struct io_async_ctx *io;
2623 struct iov_iter iter;
2626 ret = io_prep_rw(req, sqe, force_nonblock);
2630 if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
2633 req->fsize = rlimit(RLIMIT_FSIZE);
2635 /* either don't need iovec imported or already have it */
2636 if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
2640 io->rw.iov = io->rw.fast_iov;
2642 ret = io_import_iovec(WRITE, req, &io->rw.iov, &iter, !force_nonblock);
2647 io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter);
2651 static int io_write(struct io_kiocb *req, bool force_nonblock)
2653 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
2654 struct kiocb *kiocb = &req->rw.kiocb;
2655 struct iov_iter iter;
2657 ssize_t ret, io_size;
2659 ret = io_import_iovec(WRITE, req, &iovec, &iter, !force_nonblock);
2663 /* Ensure we clear previously set non-block flag */
2664 if (!force_nonblock)
2665 req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT;
2669 if (req->flags & REQ_F_LINK_HEAD)
2670 req->result = io_size;
2673 * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
2674 * we know to async punt it even if it was opened O_NONBLOCK
2676 if (force_nonblock && !io_file_supports_async(req->file, WRITE))
2679 /* file path doesn't support NOWAIT for non-direct_IO */
2680 if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
2681 (req->flags & REQ_F_ISREG))
2684 iov_count = iov_iter_count(&iter);
2685 ret = rw_verify_area(WRITE, req->file, &kiocb->ki_pos, iov_count);
2690 * Open-code file_start_write here to grab freeze protection,
2691 * which will be released by another thread in
2692 * io_complete_rw(). Fool lockdep by telling it the lock got
2693 * released so that it doesn't complain about the held lock when
2694 * we return to userspace.
2696 if (req->flags & REQ_F_ISREG) {
2697 __sb_start_write(file_inode(req->file)->i_sb,
2698 SB_FREEZE_WRITE, true);
2699 __sb_writers_release(file_inode(req->file)->i_sb,
2702 kiocb->ki_flags |= IOCB_WRITE;
2704 if (!force_nonblock)
2705 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = req->fsize;
2707 if (req->file->f_op->write_iter)
2708 ret2 = call_write_iter(req->file, kiocb, &iter);
2710 ret2 = loop_rw_iter(WRITE, req->file, kiocb, &iter);
2712 if (!force_nonblock)
2713 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
2716 * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
2717 * retry them without IOCB_NOWAIT.
2719 if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
2721 if (!force_nonblock || ret2 != -EAGAIN) {
2722 kiocb_done(kiocb, ret2);
2725 ret = io_setup_async_rw(req, io_size, iovec,
2726 inline_vecs, &iter);
2729 /* any defer here is final, must blocking retry */
2730 if (!file_can_poll(req->file))
2731 req->flags |= REQ_F_MUST_PUNT;
2736 req->flags &= ~REQ_F_NEED_CLEANUP;
2741 static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
2743 struct io_splice* sp = &req->splice;
2744 unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
2747 if (req->flags & REQ_F_NEED_CLEANUP)
2751 sp->off_in = READ_ONCE(sqe->splice_off_in);
2752 sp->off_out = READ_ONCE(sqe->off);
2753 sp->len = READ_ONCE(sqe->len);
2754 sp->flags = READ_ONCE(sqe->splice_flags);
2756 if (unlikely(sp->flags & ~valid_flags))
2759 ret = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in), &sp->file_in,
2760 (sp->flags & SPLICE_F_FD_IN_FIXED));
2763 req->flags |= REQ_F_NEED_CLEANUP;
2765 if (!S_ISREG(file_inode(sp->file_in)->i_mode))
2766 req->work.flags |= IO_WQ_WORK_UNBOUND;
2771 static int io_splice(struct io_kiocb *req, bool force_nonblock)
2773 struct io_splice *sp = &req->splice;
2774 struct file *in = sp->file_in;
2775 struct file *out = sp->file_out;
2776 unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
2777 loff_t *poff_in, *poff_out;
2783 poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
2784 poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
2785 ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
2786 if (force_nonblock && ret == -EAGAIN)
2789 io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
2790 req->flags &= ~REQ_F_NEED_CLEANUP;
2792 io_cqring_add_event(req, ret);
2794 req_set_fail_links(req);
2800 * IORING_OP_NOP just posts a completion event, nothing else.
2802 static int io_nop(struct io_kiocb *req)
2804 struct io_ring_ctx *ctx = req->ctx;
2806 if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
2809 io_cqring_add_event(req, 0);
2814 static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe)
2816 struct io_ring_ctx *ctx = req->ctx;
2821 if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
2823 if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
2826 req->sync.flags = READ_ONCE(sqe->fsync_flags);
2827 if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
2830 req->sync.off = READ_ONCE(sqe->off);
2831 req->sync.len = READ_ONCE(sqe->len);
2835 static bool io_req_cancelled(struct io_kiocb *req)
2837 if (req->work.flags & IO_WQ_WORK_CANCEL) {
2838 req_set_fail_links(req);
2839 io_cqring_add_event(req, -ECANCELED);
2847 static void __io_fsync(struct io_kiocb *req)
2849 loff_t end = req->sync.off + req->sync.len;
2852 ret = vfs_fsync_range(req->file, req->sync.off,
2853 end > 0 ? end : LLONG_MAX,
2854 req->sync.flags & IORING_FSYNC_DATASYNC);
2856 req_set_fail_links(req);
2857 io_cqring_add_event(req, ret);
2861 static void io_fsync_finish(struct io_wq_work **workptr)
2863 struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
2865 if (io_req_cancelled(req))
2868 io_steal_work(req, workptr);
2871 static int io_fsync(struct io_kiocb *req, bool force_nonblock)
2873 /* fsync always requires a blocking context */
2874 if (force_nonblock) {
2875 req->work.func = io_fsync_finish;
2882 static void __io_fallocate(struct io_kiocb *req)
2886 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = req->fsize;
2887 ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
2889 current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
2891 req_set_fail_links(req);
2892 io_cqring_add_event(req, ret);
2896 static void io_fallocate_finish(struct io_wq_work **workptr)
2898 struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
2900 if (io_req_cancelled(req))
2902 __io_fallocate(req);
2903 io_steal_work(req, workptr);
2906 static int io_fallocate_prep(struct io_kiocb *req,
2907 const struct io_uring_sqe *sqe)
2909 if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
2912 req->sync.off = READ_ONCE(sqe->off);
2913 req->sync.len = READ_ONCE(sqe->addr);
2914 req->sync.mode = READ_ONCE(sqe->len);
2915 req->fsize = rlimit(RLIMIT_FSIZE);
2919 static int io_fallocate(struct io_kiocb *req, bool force_nonblock)
2921 /* fallocate always requiring blocking context */
2922 if (force_nonblock) {
2923 req->work.func = io_fallocate_finish;
2927 __io_fallocate(req);
2931 static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
2933 const char __user *fname;
2936 if (sqe->ioprio || sqe->buf_index)
2938 if (req->flags & REQ_F_FIXED_FILE)
2940 if (req->flags & REQ_F_NEED_CLEANUP)
2943 req->open.dfd = READ_ONCE(sqe->fd);
2944 req->open.how.mode = READ_ONCE(sqe->len);
2945 fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
2946 req->open.how.flags = READ_ONCE(sqe->open_flags);
2947 if (force_o_largefile())
2948 req->open.how.flags |= O_LARGEFILE;
2950 req->open.filename = getname(fname);
2951 if (IS_ERR(req->open.filename)) {
2952 ret = PTR_ERR(req->open.filename);
2953 req->open.filename = NULL;
2957 req->open.nofile = rlimit(RLIMIT_NOFILE);
2958 req->flags |= REQ_F_NEED_CLEANUP;
2962 static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
2964 struct open_how __user *how;
2965 const char __user *fname;
2969 if (sqe->ioprio || sqe->buf_index)
2971 if (req->flags & REQ_F_FIXED_FILE)
2973 if (req->flags & REQ_F_NEED_CLEANUP)
2976 req->open.dfd = READ_ONCE(sqe->fd);
2977 fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
2978 how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
2979 len = READ_ONCE(sqe->len);
2981 if (len < OPEN_HOW_SIZE_VER0)
2984 ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
2989 if (!(req->open.how.flags & O_PATH) && force_o_largefile())
2990 req->open.how.flags |= O_LARGEFILE;
2992 req->open.filename = getname(fname);
2993 if (IS_ERR(req->open.filename)) {
2994 ret = PTR_ERR(req->open.filename);
2995 req->open.filename = NULL;
2999 req->open.nofile = rlimit(RLIMIT_NOFILE);
3000 req->flags |= REQ_F_NEED_CLEANUP;
3004 static int io_openat2(struct io_kiocb *req, bool force_nonblock)
3006 struct open_flags op;
3013 ret = build_open_flags(&req->open.how, &op);
3017 ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
3021 file = do_filp_open(req->open.dfd, req->open.filename, &op);
3024 ret = PTR_ERR(file);
3026 fsnotify_open(file);
3027 fd_install(ret, file);
3030 putname(req->open.filename);
3031 req->flags &= ~REQ_F_NEED_CLEANUP;
3033 req_set_fail_links(req);
3034 io_cqring_add_event(req, ret);
3039 static int io_openat(struct io_kiocb *req, bool force_nonblock)
3041 req->open.how = build_open_how(req->open.how.flags, req->open.how.mode);
3042 return io_openat2(req, force_nonblock);
3045 static int io_remove_buffers_prep(struct io_kiocb *req,
3046 const struct io_uring_sqe *sqe)
3048 struct io_provide_buf *p = &req->pbuf;
3051 if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off)
3054 tmp = READ_ONCE(sqe->fd);
3055 if (!tmp || tmp > USHRT_MAX)
3058 memset(p, 0, sizeof(*p));
3060 p->bgid = READ_ONCE(sqe->buf_group);
3064 static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
3065 int bgid, unsigned nbufs)
3069 /* shouldn't happen */
3073 /* the head kbuf is the list itself */
3074 while (!list_empty(&buf->list)) {
3075 struct io_buffer *nxt;
3077 nxt = list_first_entry(&buf->list, struct io_buffer, list);
3078 list_del(&nxt->list);
3085 idr_remove(&ctx->io_buffer_idr, bgid);
3090 static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock)
3092 struct io_provide_buf *p = &req->pbuf;
3093 struct io_ring_ctx *ctx = req->ctx;
3094 struct io_buffer *head;
3097 io_ring_submit_lock(ctx, !force_nonblock);
3099 lockdep_assert_held(&ctx->uring_lock);
3102 head = idr_find(&ctx->io_buffer_idr, p->bgid);
3104 ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
3106 io_ring_submit_lock(ctx, !force_nonblock);
3108 req_set_fail_links(req);
3109 io_cqring_add_event(req, ret);
3114 static int io_provide_buffers_prep(struct io_kiocb *req,
3115 const struct io_uring_sqe *sqe)
3117 struct io_provide_buf *p = &req->pbuf;
3120 if (sqe->ioprio || sqe->rw_flags)
3123 tmp = READ_ONCE(sqe->fd);
3124 if (!tmp || tmp > USHRT_MAX)
3127 p->addr = READ_ONCE(sqe->addr);
3128 p->len = READ_ONCE(sqe->len);
3130 if (!access_ok(u64_to_user_ptr(p->addr), p->len))
3133 p->bgid = READ_ONCE(sqe->buf_group);
3134 tmp = READ_ONCE(sqe->off);
3135 if (tmp > USHRT_MAX)
3141 static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
3143 struct io_buffer *buf;
3144 u64 addr = pbuf->addr;
3145 int i, bid = pbuf->bid;
3147 for (i = 0; i < pbuf->nbufs; i++) {
3148 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
3153 buf->len = pbuf->len;
3158 INIT_LIST_HEAD(&buf->list);
3161 list_add_tail(&buf->list, &(*head)->list);
3165 return i ? i : -ENOMEM;
3168 static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock)
3170 struct io_provide_buf *p = &req->pbuf;
3171 struct io_ring_ctx *ctx = req->ctx;
3172 struct io_buffer *head, *list;
3175 io_ring_submit_lock(ctx, !force_nonblock);
3177 lockdep_assert_held(&ctx->uring_lock);
3179 list = head = idr_find(&ctx->io_buffer_idr, p->bgid);
3181 ret = io_add_buffers(p, &head);
3186 ret = idr_alloc(&ctx->io_buffer_idr, head, p->bgid, p->bgid + 1,
3189 __io_remove_buffers(ctx, head, p->bgid, -1U);
3194 io_ring_submit_unlock(ctx, !force_nonblock);
3196 req_set_fail_links(req);
3197 io_cqring_add_event(req, ret);
3202 static int io_epoll_ctl_prep(struct io_kiocb *req,
3203 const struct io_uring_sqe *sqe)
3205 #if defined(CONFIG_EPOLL)
3206 if (sqe->ioprio || sqe->buf_index)
3209 req->epoll.epfd = READ_ONCE(sqe->fd);
3210 req->epoll.op = READ_ONCE(sqe->len);
3211 req->epoll.fd = READ_ONCE(sqe->off);
3213 if (ep_op_has_event(req->epoll.op)) {
3214 struct epoll_event __user *ev;
3216 ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
3217 if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
3227 static int io_epoll_ctl(struct io_kiocb *req, bool force_nonblock)
3229 #if defined(CONFIG_EPOLL)
3230 struct io_epoll *ie = &req->epoll;
3233 ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
3234 if (force_nonblock && ret == -EAGAIN)
3238 req_set_fail_links(req);
3239 io_cqring_add_event(req, ret);
3247 static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3249 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
3250 if (sqe->ioprio || sqe->buf_index || sqe->off)
3253 req->madvise.addr = READ_ONCE(sqe->addr);
3254 req->madvise.len = READ_ONCE(sqe->len);
3255 req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
3262 static int io_madvise(struct io_kiocb *req, bool force_nonblock)
3264 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
3265 struct io_madvise *ma = &req->madvise;
3271 ret = do_madvise(ma->addr, ma->len, ma->advice);
3273 req_set_fail_links(req);
3274 io_cqring_add_event(req, ret);
3282 static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3284 if (sqe->ioprio || sqe->buf_index || sqe->addr)
3287 req->fadvise.offset = READ_ONCE(sqe->off);
3288 req->fadvise.len = READ_ONCE(sqe->len);
3289 req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
3293 static int io_fadvise(struct io_kiocb *req, bool force_nonblock)
3295 struct io_fadvise *fa = &req->fadvise;
3298 if (force_nonblock) {
3299 switch (fa->advice) {
3300 case POSIX_FADV_NORMAL:
3301 case POSIX_FADV_RANDOM:
3302 case POSIX_FADV_SEQUENTIAL:
3309 ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
3311 req_set_fail_links(req);
3312 io_cqring_add_event(req, ret);
3317 static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3319 const char __user *fname;
3320 unsigned lookup_flags;
3323 if (sqe->ioprio || sqe->buf_index)
3325 if (req->flags & REQ_F_FIXED_FILE)
3327 if (req->flags & REQ_F_NEED_CLEANUP)
3330 req->open.dfd = READ_ONCE(sqe->fd);
3331 req->open.mask = READ_ONCE(sqe->len);
3332 fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
3333 req->open.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
3334 req->open.how.flags = READ_ONCE(sqe->statx_flags);
3336 if (vfs_stat_set_lookup_flags(&lookup_flags, req->open.how.flags))
3339 req->open.filename = getname_flags(fname, lookup_flags, NULL);
3340 if (IS_ERR(req->open.filename)) {
3341 ret = PTR_ERR(req->open.filename);
3342 req->open.filename = NULL;
3346 req->flags |= REQ_F_NEED_CLEANUP;
3350 static int io_statx(struct io_kiocb *req, bool force_nonblock)
3352 struct io_open *ctx = &req->open;
3353 unsigned lookup_flags;
3358 if (force_nonblock) {
3359 /* only need file table for an actual valid fd */
3360 if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
3361 req->flags |= REQ_F_NO_FILE_TABLE;
3365 if (vfs_stat_set_lookup_flags(&lookup_flags, ctx->how.flags))
3369 /* filename_lookup() drops it, keep a reference */
3370 ctx->filename->refcnt++;
3372 ret = filename_lookup(ctx->dfd, ctx->filename, lookup_flags, &path,
3377 ret = vfs_getattr(&path, &stat, ctx->mask, ctx->how.flags);
3379 if (retry_estale(ret, lookup_flags)) {
3380 lookup_flags |= LOOKUP_REVAL;
3384 ret = cp_statx(&stat, ctx->buffer);
3386 putname(ctx->filename);
3387 req->flags &= ~REQ_F_NEED_CLEANUP;
3389 req_set_fail_links(req);
3390 io_cqring_add_event(req, ret);
3395 static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3398 * If we queue this for async, it must not be cancellable. That would
3399 * leave the 'file' in an undeterminate state.
3401 req->work.flags |= IO_WQ_WORK_NO_CANCEL;
3403 if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
3404 sqe->rw_flags || sqe->buf_index)
3406 if (req->flags & REQ_F_FIXED_FILE)
3409 req->close.fd = READ_ONCE(sqe->fd);
3410 if (req->file->f_op == &io_uring_fops ||
3411 req->close.fd == req->ctx->ring_fd)
3417 /* only called when __close_fd_get_file() is done */
3418 static void __io_close_finish(struct io_kiocb *req)
3422 ret = filp_close(req->close.put_file, req->work.files);
3424 req_set_fail_links(req);
3425 io_cqring_add_event(req, ret);
3426 fput(req->close.put_file);
3430 static void io_close_finish(struct io_wq_work **workptr)
3432 struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
3434 /* not cancellable, don't do io_req_cancelled() */
3435 __io_close_finish(req);
3436 io_steal_work(req, workptr);
3439 static int io_close(struct io_kiocb *req, bool force_nonblock)
3443 req->close.put_file = NULL;
3444 ret = __close_fd_get_file(req->close.fd, &req->close.put_file);
3448 /* if the file has a flush method, be safe and punt to async */
3449 if (req->close.put_file->f_op->flush && force_nonblock) {
3450 /* submission ref will be dropped, take it for async */
3451 refcount_inc(&req->refs);
3453 req->work.func = io_close_finish;
3455 * Do manual async queue here to avoid grabbing files - we don't
3456 * need the files, and it'll cause io_close_finish() to close
3457 * the file again and cause a double CQE entry for this request
3459 io_queue_async_work(req);
3464 * No ->flush(), safely close from here and just punt the
3465 * fput() to async context.
3467 __io_close_finish(req);
3471 static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3473 struct io_ring_ctx *ctx = req->ctx;
3478 if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
3480 if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
3483 req->sync.off = READ_ONCE(sqe->off);
3484 req->sync.len = READ_ONCE(sqe->len);
3485 req->sync.flags = READ_ONCE(sqe->sync_range_flags);
3489 static void __io_sync_file_range(struct io_kiocb *req)
3493 ret = sync_file_range(req->file, req->sync.off, req->sync.len,
3496 req_set_fail_links(req);
3497 io_cqring_add_event(req, ret);
3502 static void io_sync_file_range_finish(struct io_wq_work **workptr)
3504 struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
3506 if (io_req_cancelled(req))
3508 __io_sync_file_range(req);
3509 io_steal_work(req, workptr);
3512 static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
3514 /* sync_file_range always requires a blocking context */
3515 if (force_nonblock) {
3516 req->work.func = io_sync_file_range_finish;
3520 __io_sync_file_range(req);
3524 #if defined(CONFIG_NET)
3525 static int io_setup_async_msg(struct io_kiocb *req,
3526 struct io_async_msghdr *kmsg)
3530 if (io_alloc_async_ctx(req)) {
3531 if (kmsg->iov != kmsg->fast_iov)
3535 req->flags |= REQ_F_NEED_CLEANUP;
3536 memcpy(&req->io->msg, kmsg, sizeof(*kmsg));
3540 static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3542 struct io_sr_msg *sr = &req->sr_msg;
3543 struct io_async_ctx *io = req->io;
3546 sr->msg_flags = READ_ONCE(sqe->msg_flags);
3547 sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
3548 sr->len = READ_ONCE(sqe->len);
3550 #ifdef CONFIG_COMPAT
3551 if (req->ctx->compat)
3552 sr->msg_flags |= MSG_CMSG_COMPAT;
3555 if (!io || req->opcode == IORING_OP_SEND)
3557 /* iovec is already imported */
3558 if (req->flags & REQ_F_NEED_CLEANUP)
3561 io->msg.iov = io->msg.fast_iov;
3562 ret = sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags,
3565 req->flags |= REQ_F_NEED_CLEANUP;
3569 static int io_sendmsg(struct io_kiocb *req, bool force_nonblock)
3571 struct io_async_msghdr *kmsg = NULL;
3572 struct socket *sock;
3575 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3578 sock = sock_from_file(req->file, &ret);
3580 struct io_async_ctx io;
3584 kmsg = &req->io->msg;
3585 kmsg->msg.msg_name = &req->io->msg.addr;
3586 /* if iov is set, it's allocated already */
3588 kmsg->iov = kmsg->fast_iov;
3589 kmsg->msg.msg_iter.iov = kmsg->iov;
3591 struct io_sr_msg *sr = &req->sr_msg;
3594 kmsg->msg.msg_name = &io.msg.addr;
3596 io.msg.iov = io.msg.fast_iov;
3597 ret = sendmsg_copy_msghdr(&io.msg.msg, sr->msg,
3598 sr->msg_flags, &io.msg.iov);
3603 flags = req->sr_msg.msg_flags;
3604 if (flags & MSG_DONTWAIT)
3605 req->flags |= REQ_F_NOWAIT;
3606 else if (force_nonblock)
3607 flags |= MSG_DONTWAIT;
3609 ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
3610 if (force_nonblock && ret == -EAGAIN)
3611 return io_setup_async_msg(req, kmsg);
3612 if (ret == -ERESTARTSYS)
3616 if (kmsg && kmsg->iov != kmsg->fast_iov)
3618 req->flags &= ~REQ_F_NEED_CLEANUP;
3619 io_cqring_add_event(req, ret);
3621 req_set_fail_links(req);
3626 static int io_send(struct io_kiocb *req, bool force_nonblock)
3628 struct socket *sock;
3631 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3634 sock = sock_from_file(req->file, &ret);
3636 struct io_sr_msg *sr = &req->sr_msg;
3641 ret = import_single_range(WRITE, sr->buf, sr->len, &iov,
3646 msg.msg_name = NULL;
3647 msg.msg_control = NULL;
3648 msg.msg_controllen = 0;
3649 msg.msg_namelen = 0;
3651 flags = req->sr_msg.msg_flags;
3652 if (flags & MSG_DONTWAIT)
3653 req->flags |= REQ_F_NOWAIT;
3654 else if (force_nonblock)
3655 flags |= MSG_DONTWAIT;
3657 msg.msg_flags = flags;
3658 ret = sock_sendmsg(sock, &msg);
3659 if (force_nonblock && ret == -EAGAIN)
3661 if (ret == -ERESTARTSYS)
3665 io_cqring_add_event(req, ret);
3667 req_set_fail_links(req);
3672 static int __io_recvmsg_copy_hdr(struct io_kiocb *req, struct io_async_ctx *io)
3674 struct io_sr_msg *sr = &req->sr_msg;
3675 struct iovec __user *uiov;
3679 ret = __copy_msghdr_from_user(&io->msg.msg, sr->msg, &io->msg.uaddr,
3684 if (req->flags & REQ_F_BUFFER_SELECT) {
3687 if (copy_from_user(io->msg.iov, uiov, sizeof(*uiov)))
3689 sr->len = io->msg.iov[0].iov_len;
3690 iov_iter_init(&io->msg.msg.msg_iter, READ, io->msg.iov, 1,
3694 ret = import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
3695 &io->msg.iov, &io->msg.msg.msg_iter);
3703 #ifdef CONFIG_COMPAT
3704 static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
3705 struct io_async_ctx *io)
3707 struct compat_msghdr __user *msg_compat;
3708 struct io_sr_msg *sr = &req->sr_msg;
3709 struct compat_iovec __user *uiov;
3714 msg_compat = (struct compat_msghdr __user *) sr->msg;
3715 ret = __get_compat_msghdr(&io->msg.msg, msg_compat, &io->msg.uaddr,
3720 uiov = compat_ptr(ptr);
3721 if (req->flags & REQ_F_BUFFER_SELECT) {
3722 compat_ssize_t clen;
3726 if (!access_ok(uiov, sizeof(*uiov)))
3728 if (__get_user(clen, &uiov->iov_len))
3732 sr->len = io->msg.iov[0].iov_len;
3735 ret = compat_import_iovec(READ, uiov, len, UIO_FASTIOV,
3737 &io->msg.msg.msg_iter);
3746 static int io_recvmsg_copy_hdr(struct io_kiocb *req, struct io_async_ctx *io)
3748 io->msg.iov = io->msg.fast_iov;
3750 #ifdef CONFIG_COMPAT
3751 if (req->ctx->compat)
3752 return __io_compat_recvmsg_copy_hdr(req, io);
3755 return __io_recvmsg_copy_hdr(req, io);
3758 static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
3759 int *cflags, bool needs_lock)
3761 struct io_sr_msg *sr = &req->sr_msg;
3762 struct io_buffer *kbuf;
3764 if (!(req->flags & REQ_F_BUFFER_SELECT))
3767 kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
3772 req->flags |= REQ_F_BUFFER_SELECTED;
3774 *cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
3775 *cflags |= IORING_CQE_F_BUFFER;
3779 static int io_recvmsg_prep(struct io_kiocb *req,
3780 const struct io_uring_sqe *sqe)
3782 struct io_sr_msg *sr = &req->sr_msg;
3783 struct io_async_ctx *io = req->io;
3786 sr->msg_flags = READ_ONCE(sqe->msg_flags);
3787 sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr));
3788 sr->len = READ_ONCE(sqe->len);
3789 sr->bgid = READ_ONCE(sqe->buf_group);
3791 #ifdef CONFIG_COMPAT
3792 if (req->ctx->compat)
3793 sr->msg_flags |= MSG_CMSG_COMPAT;
3796 if (!io || req->opcode == IORING_OP_RECV)
3798 /* iovec is already imported */
3799 if (req->flags & REQ_F_NEED_CLEANUP)
3802 ret = io_recvmsg_copy_hdr(req, io);
3804 req->flags |= REQ_F_NEED_CLEANUP;
3808 static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
3810 struct io_async_msghdr *kmsg = NULL;
3811 struct socket *sock;
3812 int ret, cflags = 0;
3814 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3817 sock = sock_from_file(req->file, &ret);
3819 struct io_buffer *kbuf;
3820 struct io_async_ctx io;
3824 kmsg = &req->io->msg;
3825 kmsg->msg.msg_name = &req->io->msg.addr;
3826 /* if iov is set, it's allocated already */
3828 kmsg->iov = kmsg->fast_iov;
3829 kmsg->msg.msg_iter.iov = kmsg->iov;
3832 kmsg->msg.msg_name = &io.msg.addr;
3834 ret = io_recvmsg_copy_hdr(req, &io);
3839 kbuf = io_recv_buffer_select(req, &cflags, !force_nonblock);
3841 return PTR_ERR(kbuf);
3843 kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
3844 iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov,
3845 1, req->sr_msg.len);
3848 flags = req->sr_msg.msg_flags;
3849 if (flags & MSG_DONTWAIT)
3850 req->flags |= REQ_F_NOWAIT;
3851 else if (force_nonblock)
3852 flags |= MSG_DONTWAIT;
3854 ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.msg,
3855 kmsg->uaddr, flags);
3856 if (force_nonblock && ret == -EAGAIN)
3857 return io_setup_async_msg(req, kmsg);
3858 if (ret == -ERESTARTSYS)
3862 if (kmsg && kmsg->iov != kmsg->fast_iov)
3864 req->flags &= ~REQ_F_NEED_CLEANUP;
3865 __io_cqring_add_event(req, ret, cflags);
3867 req_set_fail_links(req);
3872 static int io_recv(struct io_kiocb *req, bool force_nonblock)
3874 struct io_buffer *kbuf = NULL;
3875 struct socket *sock;
3876 int ret, cflags = 0;
3878 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3881 sock = sock_from_file(req->file, &ret);
3883 struct io_sr_msg *sr = &req->sr_msg;
3884 void __user *buf = sr->buf;
3889 kbuf = io_recv_buffer_select(req, &cflags, !force_nonblock);
3891 return PTR_ERR(kbuf);
3893 buf = u64_to_user_ptr(kbuf->addr);
3895 ret = import_single_range(READ, buf, sr->len, &iov,
3902 req->flags |= REQ_F_NEED_CLEANUP;
3903 msg.msg_name = NULL;
3904 msg.msg_control = NULL;
3905 msg.msg_controllen = 0;
3906 msg.msg_namelen = 0;
3907 msg.msg_iocb = NULL;
3910 flags = req->sr_msg.msg_flags;
3911 if (flags & MSG_DONTWAIT)
3912 req->flags |= REQ_F_NOWAIT;
3913 else if (force_nonblock)
3914 flags |= MSG_DONTWAIT;
3916 ret = sock_recvmsg(sock, &msg, flags);
3917 if (force_nonblock && ret == -EAGAIN)
3919 if (ret == -ERESTARTSYS)
3924 req->flags &= ~REQ_F_NEED_CLEANUP;
3925 __io_cqring_add_event(req, ret, cflags);
3927 req_set_fail_links(req);
3932 static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3934 struct io_accept *accept = &req->accept;
3936 if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
3938 if (sqe->ioprio || sqe->len || sqe->buf_index)
3941 accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
3942 accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
3943 accept->flags = READ_ONCE(sqe->accept_flags);
3944 accept->nofile = rlimit(RLIMIT_NOFILE);
3948 static int __io_accept(struct io_kiocb *req, bool force_nonblock)
3950 struct io_accept *accept = &req->accept;
3951 unsigned file_flags;
3954 file_flags = force_nonblock ? O_NONBLOCK : 0;
3955 ret = __sys_accept4_file(req->file, file_flags, accept->addr,
3956 accept->addr_len, accept->flags,
3958 if (ret == -EAGAIN && force_nonblock)
3960 if (ret == -ERESTARTSYS)
3963 req_set_fail_links(req);
3964 io_cqring_add_event(req, ret);
3969 static void io_accept_finish(struct io_wq_work **workptr)
3971 struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
3973 if (io_req_cancelled(req))
3975 __io_accept(req, false);
3976 io_steal_work(req, workptr);
3979 static int io_accept(struct io_kiocb *req, bool force_nonblock)
3983 ret = __io_accept(req, force_nonblock);
3984 if (ret == -EAGAIN && force_nonblock) {
3985 req->work.func = io_accept_finish;
3991 static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3993 struct io_connect *conn = &req->connect;
3994 struct io_async_ctx *io = req->io;
3996 if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
3998 if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags)
4001 conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
4002 conn->addr_len = READ_ONCE(sqe->addr2);
4007 return move_addr_to_kernel(conn->addr, conn->addr_len,
4008 &io->connect.address);
4011 static int io_connect(struct io_kiocb *req, bool force_nonblock)
4013 struct io_async_ctx __io, *io;
4014 unsigned file_flags;
4020 ret = move_addr_to_kernel(req->connect.addr,
4021 req->connect.addr_len,
4022 &__io.connect.address);
4028 file_flags = force_nonblock ? O_NONBLOCK : 0;
4030 ret = __sys_connect_file(req->file, &io->connect.address,
4031 req->connect.addr_len, file_flags);
4032 if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
4035 if (io_alloc_async_ctx(req)) {
4039 memcpy(&req->io->connect, &__io.connect, sizeof(__io.connect));
4042 if (ret == -ERESTARTSYS)
4046 req_set_fail_links(req);
4047 io_cqring_add_event(req, ret);
4051 #else /* !CONFIG_NET */
4052 static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4057 static int io_sendmsg(struct io_kiocb *req, bool force_nonblock)
4062 static int io_send(struct io_kiocb *req, bool force_nonblock)
4067 static int io_recvmsg_prep(struct io_kiocb *req,
4068 const struct io_uring_sqe *sqe)
4073 static int io_recvmsg(struct io_kiocb *req, bool force_nonblock)
4078 static int io_recv(struct io_kiocb *req, bool force_nonblock)
4083 static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4088 static int io_accept(struct io_kiocb *req, bool force_nonblock)
4093 static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4098 static int io_connect(struct io_kiocb *req, bool force_nonblock)
4102 #endif /* CONFIG_NET */
4104 struct io_poll_table {
4105 struct poll_table_struct pt;
4106 struct io_kiocb *req;
4110 static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
4111 struct wait_queue_head *head)
4113 if (unlikely(poll->head)) {
4114 pt->error = -EINVAL;
4120 add_wait_queue(head, &poll->wait);
4123 static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
4124 struct poll_table_struct *p)
4126 struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
4128 __io_queue_proc(&pt->req->apoll->poll, pt, head);
4131 static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
4132 __poll_t mask, task_work_func_t func)
4134 struct task_struct *tsk;
4137 /* for instances that support it check for an event match first: */
4138 if (mask && !(mask & poll->events))
4141 trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
4143 list_del_init(&poll->wait.entry);
4147 init_task_work(&req->task_work, func);
4149 * If this fails, then the task is exiting. Punt to one of the io-wq
4150 * threads to ensure the work gets run, we can't always rely on exit
4151 * cancelation taking care of this.
4153 ret = task_work_add(tsk, &req->task_work, true);
4154 if (unlikely(ret)) {
4155 tsk = io_wq_get_task(req->ctx->io_wq);
4156 task_work_add(tsk, &req->task_work, true);
4158 wake_up_process(tsk);
4162 static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll)
4163 __acquires(&req->ctx->completion_lock)
4165 struct io_ring_ctx *ctx = req->ctx;
4167 if (!req->result && !READ_ONCE(poll->canceled)) {
4168 struct poll_table_struct pt = { ._key = poll->events };
4170 req->result = vfs_poll(req->file, &pt) & poll->events;
4173 spin_lock_irq(&ctx->completion_lock);
4174 if (!req->result && !READ_ONCE(poll->canceled)) {
4175 add_wait_queue(poll->head, &poll->wait);
4182 static void io_async_task_func(struct callback_head *cb)
4184 struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
4185 struct async_poll *apoll = req->apoll;
4186 struct io_ring_ctx *ctx = req->ctx;
4189 trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);
4191 if (io_poll_rewait(req, &apoll->poll)) {
4192 spin_unlock_irq(&ctx->completion_lock);
4196 if (hash_hashed(&req->hash_node))
4197 hash_del(&req->hash_node);
4199 canceled = READ_ONCE(apoll->poll.canceled);
4201 io_cqring_fill_event(req, -ECANCELED);
4202 io_commit_cqring(ctx);
4205 spin_unlock_irq(&ctx->completion_lock);
4207 /* restore ->work in case we need to retry again */
4208 memcpy(&req->work, &apoll->work, sizeof(req->work));
4212 io_cqring_ev_posted(ctx);
4213 req_set_fail_links(req);
4214 io_double_put_req(req);
4218 __set_current_state(TASK_RUNNING);
4219 mutex_lock(&ctx->uring_lock);
4220 __io_queue_sqe(req, NULL);
4221 mutex_unlock(&ctx->uring_lock);
4226 static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
4229 struct io_kiocb *req = wait->private;
4230 struct io_poll_iocb *poll = &req->apoll->poll;
4232 trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data,
4235 return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func);
4238 static void io_poll_req_insert(struct io_kiocb *req)
4240 struct io_ring_ctx *ctx = req->ctx;
4241 struct hlist_head *list;
4243 list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
4244 hlist_add_head(&req->hash_node, list);
4247 static __poll_t __io_arm_poll_handler(struct io_kiocb *req,
4248 struct io_poll_iocb *poll,
4249 struct io_poll_table *ipt, __poll_t mask,
4250 wait_queue_func_t wake_func)
4251 __acquires(&ctx->completion_lock)
4253 struct io_ring_ctx *ctx = req->ctx;
4254 bool cancel = false;
4256 poll->file = req->file;
4258 poll->done = poll->canceled = false;
4259 poll->events = mask;
4261 ipt->pt._key = mask;
4263 ipt->error = -EINVAL;
4265 INIT_LIST_HEAD(&poll->wait.entry);
4266 init_waitqueue_func_entry(&poll->wait, wake_func);
4267 poll->wait.private = req;
4269 mask = vfs_poll(req->file, &ipt->pt) & poll->events;
4271 spin_lock_irq(&ctx->completion_lock);
4272 if (likely(poll->head)) {
4273 spin_lock(&poll->head->lock);
4274 if (unlikely(list_empty(&poll->wait.entry))) {
4280 if (mask || ipt->error)
4281 list_del_init(&poll->wait.entry);
4283 WRITE_ONCE(poll->canceled, true);
4284 else if (!poll->done) /* actually waiting for an event */
4285 io_poll_req_insert(req);
4286 spin_unlock(&poll->head->lock);
4292 static bool io_arm_poll_handler(struct io_kiocb *req)
4294 const struct io_op_def *def = &io_op_defs[req->opcode];
4295 struct io_ring_ctx *ctx = req->ctx;
4296 struct async_poll *apoll;
4297 struct io_poll_table ipt;
4300 if (!req->file || !file_can_poll(req->file))
4302 if (req->flags & (REQ_F_MUST_PUNT | REQ_F_POLLED))
4304 if (!def->pollin && !def->pollout)
4307 apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
4308 if (unlikely(!apoll))
4311 req->flags |= REQ_F_POLLED;
4312 memcpy(&apoll->work, &req->work, sizeof(req->work));
4314 get_task_struct(current);
4315 req->task = current;
4317 INIT_HLIST_NODE(&req->hash_node);
4321 mask |= POLLIN | POLLRDNORM;
4323 mask |= POLLOUT | POLLWRNORM;
4324 mask |= POLLERR | POLLPRI;
4326 ipt.pt._qproc = io_async_queue_proc;
4328 ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask,
4332 apoll->poll.done = true;
4333 spin_unlock_irq(&ctx->completion_lock);
4334 memcpy(&req->work, &apoll->work, sizeof(req->work));
4338 spin_unlock_irq(&ctx->completion_lock);
4339 trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask,
4340 apoll->poll.events);
4344 static bool __io_poll_remove_one(struct io_kiocb *req,
4345 struct io_poll_iocb *poll)
4347 bool do_complete = false;
4349 spin_lock(&poll->head->lock);
4350 WRITE_ONCE(poll->canceled, true);
4351 if (!list_empty(&poll->wait.entry)) {
4352 list_del_init(&poll->wait.entry);
4355 spin_unlock(&poll->head->lock);
4359 static bool io_poll_remove_one(struct io_kiocb *req)
4361 struct async_poll *apoll = NULL;
4364 if (req->opcode == IORING_OP_POLL_ADD) {
4365 do_complete = __io_poll_remove_one(req, &req->poll);
4368 /* non-poll requests have submit ref still */
4369 do_complete = __io_poll_remove_one(req, &req->apoll->poll);
4374 hash_del(&req->hash_node);
4376 if (do_complete && apoll) {
4378 * restore ->work because we need to call io_req_work_drop_env.
4380 memcpy(&req->work, &apoll->work, sizeof(req->work));
4385 io_cqring_fill_event(req, -ECANCELED);
4386 io_commit_cqring(req->ctx);
4387 req->flags |= REQ_F_COMP_LOCKED;
4394 static void io_poll_remove_all(struct io_ring_ctx *ctx)
4396 struct hlist_node *tmp;
4397 struct io_kiocb *req;
4400 spin_lock_irq(&ctx->completion_lock);
4401 for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
4402 struct hlist_head *list;
4404 list = &ctx->cancel_hash[i];
4405 hlist_for_each_entry_safe(req, tmp, list, hash_node)
4406 posted += io_poll_remove_one(req);
4408 spin_unlock_irq(&ctx->completion_lock);
4411 io_cqring_ev_posted(ctx);
4414 static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
4416 struct hlist_head *list;
4417 struct io_kiocb *req;
4419 list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
4420 hlist_for_each_entry(req, list, hash_node) {
4421 if (sqe_addr != req->user_data)
4423 if (io_poll_remove_one(req))
4431 static int io_poll_remove_prep(struct io_kiocb *req,
4432 const struct io_uring_sqe *sqe)
4434 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
4436 if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
4440 req->poll.addr = READ_ONCE(sqe->addr);
4445 * Find a running poll command that matches one specified in sqe->addr,
4446 * and remove it if found.
4448 static int io_poll_remove(struct io_kiocb *req)
4450 struct io_ring_ctx *ctx = req->ctx;
4454 addr = req->poll.addr;
4455 spin_lock_irq(&ctx->completion_lock);
4456 ret = io_poll_cancel(ctx, addr);
4457 spin_unlock_irq(&ctx->completion_lock);
4459 io_cqring_add_event(req, ret);
4461 req_set_fail_links(req);
4466 static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error)
4468 struct io_ring_ctx *ctx = req->ctx;
4470 req->poll.done = true;
4471 io_cqring_fill_event(req, error ? error : mangle_poll(mask));
4472 io_commit_cqring(ctx);
4475 static void io_poll_task_handler(struct io_kiocb *req, struct io_kiocb **nxt)
4477 struct io_ring_ctx *ctx = req->ctx;
4478 struct io_poll_iocb *poll = &req->poll;
4480 if (io_poll_rewait(req, poll)) {
4481 spin_unlock_irq(&ctx->completion_lock);
4485 hash_del(&req->hash_node);
4486 io_poll_complete(req, req->result, 0);
4487 req->flags |= REQ_F_COMP_LOCKED;
4488 io_put_req_find_next(req, nxt);
4489 spin_unlock_irq(&ctx->completion_lock);
4491 io_cqring_ev_posted(ctx);
4494 static void io_poll_task_func(struct callback_head *cb)
4496 struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
4497 struct io_kiocb *nxt = NULL;
4499 io_poll_task_handler(req, &nxt);
4501 struct io_ring_ctx *ctx = nxt->ctx;
4503 mutex_lock(&ctx->uring_lock);
4504 __io_queue_sqe(nxt, NULL);
4505 mutex_unlock(&ctx->uring_lock);
4509 static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
4512 struct io_kiocb *req = wait->private;
4513 struct io_poll_iocb *poll = &req->poll;
4515 return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func);
4518 static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
4519 struct poll_table_struct *p)
4521 struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
4523 __io_queue_proc(&pt->req->poll, pt, head);
4526 static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4528 struct io_poll_iocb *poll = &req->poll;
4531 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
4533 if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
4538 events = READ_ONCE(sqe->poll_events);
4539 poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP;
4541 get_task_struct(current);
4542 req->task = current;
4546 static int io_poll_add(struct io_kiocb *req)
4548 struct io_poll_iocb *poll = &req->poll;
4549 struct io_ring_ctx *ctx = req->ctx;
4550 struct io_poll_table ipt;
4553 INIT_HLIST_NODE(&req->hash_node);
4554 INIT_LIST_HEAD(&req->list);
4555 ipt.pt._qproc = io_poll_queue_proc;
4557 mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events,
4560 if (mask) { /* no async, we'd stolen it */
4562 io_poll_complete(req, mask, 0);
4564 spin_unlock_irq(&ctx->completion_lock);
4567 io_cqring_ev_posted(ctx);
4573 static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
4575 struct io_timeout_data *data = container_of(timer,
4576 struct io_timeout_data, timer);
4577 struct io_kiocb *req = data->req;
4578 struct io_ring_ctx *ctx = req->ctx;
4579 unsigned long flags;
4581 atomic_inc(&ctx->cq_timeouts);
4583 spin_lock_irqsave(&ctx->completion_lock, flags);
4585 * We could be racing with timeout deletion. If the list is empty,
4586 * then timeout lookup already found it and will be handling it.
4588 if (!list_empty(&req->list)) {
4589 struct io_kiocb *prev;
4592 * Adjust the reqs sequence before the current one because it
4593 * will consume a slot in the cq_ring and the cq_tail
4594 * pointer will be increased, otherwise other timeout reqs may
4595 * return in advance without waiting for enough wait_nr.
4598 list_for_each_entry_continue_reverse(prev, &ctx->timeout_list, list)
4600 list_del_init(&req->list);
4603 io_cqring_fill_event(req, -ETIME);
4604 io_commit_cqring(ctx);
4605 spin_unlock_irqrestore(&ctx->completion_lock, flags);
4607 io_cqring_ev_posted(ctx);
4608 req_set_fail_links(req);
4610 return HRTIMER_NORESTART;
4613 static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
4615 struct io_kiocb *req;
4618 list_for_each_entry(req, &ctx->timeout_list, list) {
4619 if (user_data == req->user_data) {
4620 list_del_init(&req->list);
4629 ret = hrtimer_try_to_cancel(&req->io->timeout.timer);
4633 req_set_fail_links(req);
4634 io_cqring_fill_event(req, -ECANCELED);
4639 static int io_timeout_remove_prep(struct io_kiocb *req,
4640 const struct io_uring_sqe *sqe)
4642 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
4644 if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->len)
4647 req->timeout.addr = READ_ONCE(sqe->addr);
4648 req->timeout.flags = READ_ONCE(sqe->timeout_flags);
4649 if (req->timeout.flags)
4656 * Remove or update an existing timeout command
4658 static int io_timeout_remove(struct io_kiocb *req)
4660 struct io_ring_ctx *ctx = req->ctx;
4663 spin_lock_irq(&ctx->completion_lock);
4664 ret = io_timeout_cancel(ctx, req->timeout.addr);
4666 io_cqring_fill_event(req, ret);
4667 io_commit_cqring(ctx);
4668 spin_unlock_irq(&ctx->completion_lock);
4669 io_cqring_ev_posted(ctx);
4671 req_set_fail_links(req);
4676 static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
4677 bool is_timeout_link)
4679 struct io_timeout_data *data;
4682 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
4684 if (sqe->ioprio || sqe->buf_index || sqe->len != 1)
4686 if (sqe->off && is_timeout_link)
4688 flags = READ_ONCE(sqe->timeout_flags);
4689 if (flags & ~IORING_TIMEOUT_ABS)
4692 req->timeout.count = READ_ONCE(sqe->off);
4694 if (!req->io && io_alloc_async_ctx(req))
4697 data = &req->io->timeout;
4699 req->flags |= REQ_F_TIMEOUT;
4701 if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
4704 if (flags & IORING_TIMEOUT_ABS)
4705 data->mode = HRTIMER_MODE_ABS;
4707 data->mode = HRTIMER_MODE_REL;
4709 hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode);
4713 static int io_timeout(struct io_kiocb *req)
4715 struct io_ring_ctx *ctx = req->ctx;
4716 struct io_timeout_data *data;
4717 struct list_head *entry;
4719 u32 count = req->timeout.count;
4720 u32 seq = req->sequence;
4722 data = &req->io->timeout;
4725 * sqe->off holds how many events that need to occur for this
4726 * timeout event to be satisfied. If it isn't set, then this is
4727 * a pure timeout request, sequence isn't used.
4730 req->flags |= REQ_F_TIMEOUT_NOSEQ;
4731 spin_lock_irq(&ctx->completion_lock);
4732 entry = ctx->timeout_list.prev;
4736 req->sequence = seq + count;
4739 * Insertion sort, ensuring the first entry in the list is always
4740 * the one we need first.
4742 spin_lock_irq(&ctx->completion_lock);
4743 list_for_each_prev(entry, &ctx->timeout_list) {
4744 struct io_kiocb *nxt = list_entry(entry, struct io_kiocb, list);
4746 long long tmp, tmp_nxt;
4747 u32 nxt_offset = nxt->timeout.count;
4749 if (nxt->flags & REQ_F_TIMEOUT_NOSEQ)
4753 * Since seq + count can overflow, use type long
4756 tmp = (long long)seq + count;
4757 nxt_seq = nxt->sequence - nxt_offset;
4758 tmp_nxt = (long long)nxt_seq + nxt_offset;
4761 * cached_sq_head may overflow, and it will never overflow twice
4762 * once there is some timeout req still be valid.
4771 * Sequence of reqs after the insert one and itself should
4772 * be adjusted because each timeout req consumes a slot.
4777 req->sequence -= span;
4779 list_add(&req->list, entry);
4780 data->timer.function = io_timeout_fn;
4781 hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
4782 spin_unlock_irq(&ctx->completion_lock);
4786 static bool io_cancel_cb(struct io_wq_work *work, void *data)
4788 struct io_kiocb *req = container_of(work, struct io_kiocb, work);
4790 return req->user_data == (unsigned long) data;
4793 static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr)
4795 enum io_wq_cancel cancel_ret;
4798 cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr);
4799 switch (cancel_ret) {
4800 case IO_WQ_CANCEL_OK:
4803 case IO_WQ_CANCEL_RUNNING:
4806 case IO_WQ_CANCEL_NOTFOUND:
4814 static void io_async_find_and_cancel(struct io_ring_ctx *ctx,
4815 struct io_kiocb *req, __u64 sqe_addr,
4818 unsigned long flags;
4821 ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr);
4822 if (ret != -ENOENT) {
4823 spin_lock_irqsave(&ctx->completion_lock, flags);
4827 spin_lock_irqsave(&ctx->completion_lock, flags);
4828 ret = io_timeout_cancel(ctx, sqe_addr);
4831 ret = io_poll_cancel(ctx, sqe_addr);
4835 io_cqring_fill_event(req, ret);
4836 io_commit_cqring(ctx);
4837 spin_unlock_irqrestore(&ctx->completion_lock, flags);
4838 io_cqring_ev_posted(ctx);
4841 req_set_fail_links(req);
4845 static int io_async_cancel_prep(struct io_kiocb *req,
4846 const struct io_uring_sqe *sqe)
4848 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
4850 if (sqe->flags || sqe->ioprio || sqe->off || sqe->len ||
4854 req->cancel.addr = READ_ONCE(sqe->addr);
4858 static int io_async_cancel(struct io_kiocb *req)
4860 struct io_ring_ctx *ctx = req->ctx;
4862 io_async_find_and_cancel(ctx, req, req->cancel.addr, 0);
4866 static int io_files_update_prep(struct io_kiocb *req,
4867 const struct io_uring_sqe *sqe)
4869 if (sqe->flags || sqe->ioprio || sqe->rw_flags)
4872 req->files_update.offset = READ_ONCE(sqe->off);
4873 req->files_update.nr_args = READ_ONCE(sqe->len);
4874 if (!req->files_update.nr_args)
4876 req->files_update.arg = READ_ONCE(sqe->addr);
4880 static int io_files_update(struct io_kiocb *req, bool force_nonblock)
4882 struct io_ring_ctx *ctx = req->ctx;
4883 struct io_uring_files_update up;
4889 up.offset = req->files_update.offset;
4890 up.fds = req->files_update.arg;
4892 mutex_lock(&ctx->uring_lock);
4893 ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args);
4894 mutex_unlock(&ctx->uring_lock);
4897 req_set_fail_links(req);
4898 io_cqring_add_event(req, ret);
4903 static int io_req_defer_prep(struct io_kiocb *req,
4904 const struct io_uring_sqe *sqe)
4911 if (io_op_defs[req->opcode].file_table) {
4912 ret = io_grab_files(req);
4917 io_req_work_grab_env(req, &io_op_defs[req->opcode]);
4919 switch (req->opcode) {
4922 case IORING_OP_READV:
4923 case IORING_OP_READ_FIXED:
4924 case IORING_OP_READ:
4925 ret = io_read_prep(req, sqe, true);
4927 case IORING_OP_WRITEV:
4928 case IORING_OP_WRITE_FIXED:
4929 case IORING_OP_WRITE:
4930 ret = io_write_prep(req, sqe, true);
4932 case IORING_OP_POLL_ADD:
4933 ret = io_poll_add_prep(req, sqe);
4935 case IORING_OP_POLL_REMOVE:
4936 ret = io_poll_remove_prep(req, sqe);
4938 case IORING_OP_FSYNC:
4939 ret = io_prep_fsync(req, sqe);
4941 case IORING_OP_SYNC_FILE_RANGE:
4942 ret = io_prep_sfr(req, sqe);
4944 case IORING_OP_SENDMSG:
4945 case IORING_OP_SEND:
4946 ret = io_sendmsg_prep(req, sqe);
4948 case IORING_OP_RECVMSG:
4949 case IORING_OP_RECV:
4950 ret = io_recvmsg_prep(req, sqe);
4952 case IORING_OP_CONNECT:
4953 ret = io_connect_prep(req, sqe);
4955 case IORING_OP_TIMEOUT:
4956 ret = io_timeout_prep(req, sqe, false);
4958 case IORING_OP_TIMEOUT_REMOVE:
4959 ret = io_timeout_remove_prep(req, sqe);
4961 case IORING_OP_ASYNC_CANCEL:
4962 ret = io_async_cancel_prep(req, sqe);
4964 case IORING_OP_LINK_TIMEOUT:
4965 ret = io_timeout_prep(req, sqe, true);
4967 case IORING_OP_ACCEPT:
4968 ret = io_accept_prep(req, sqe);
4970 case IORING_OP_FALLOCATE:
4971 ret = io_fallocate_prep(req, sqe);
4973 case IORING_OP_OPENAT:
4974 ret = io_openat_prep(req, sqe);
4976 case IORING_OP_CLOSE:
4977 ret = io_close_prep(req, sqe);
4979 case IORING_OP_FILES_UPDATE:
4980 ret = io_files_update_prep(req, sqe);
4982 case IORING_OP_STATX:
4983 ret = io_statx_prep(req, sqe);
4985 case IORING_OP_FADVISE:
4986 ret = io_fadvise_prep(req, sqe);
4988 case IORING_OP_MADVISE:
4989 ret = io_madvise_prep(req, sqe);
4991 case IORING_OP_OPENAT2:
4992 ret = io_openat2_prep(req, sqe);
4994 case IORING_OP_EPOLL_CTL:
4995 ret = io_epoll_ctl_prep(req, sqe);
4997 case IORING_OP_SPLICE:
4998 ret = io_splice_prep(req, sqe);
5000 case IORING_OP_PROVIDE_BUFFERS:
5001 ret = io_provide_buffers_prep(req, sqe);
5003 case IORING_OP_REMOVE_BUFFERS:
5004 ret = io_remove_buffers_prep(req, sqe);
5007 printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
5016 static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
5018 struct io_ring_ctx *ctx = req->ctx;
5021 /* Still need defer if there is pending req in defer list. */
5022 if (!req_need_defer(req) && list_empty_careful(&ctx->defer_list))
5025 if (!req->io && io_alloc_async_ctx(req))
5028 ret = io_req_defer_prep(req, sqe);
5032 spin_lock_irq(&ctx->completion_lock);
5033 if (!req_need_defer(req) && list_empty(&ctx->defer_list)) {
5034 spin_unlock_irq(&ctx->completion_lock);
5038 trace_io_uring_defer(ctx, req, req->user_data);
5039 list_add_tail(&req->list, &ctx->defer_list);
5040 spin_unlock_irq(&ctx->completion_lock);
5041 return -EIOCBQUEUED;
5044 static void io_cleanup_req(struct io_kiocb *req)
5046 struct io_async_ctx *io = req->io;
5048 switch (req->opcode) {
5049 case IORING_OP_READV:
5050 case IORING_OP_READ_FIXED:
5051 case IORING_OP_READ:
5052 if (req->flags & REQ_F_BUFFER_SELECTED)
5053 kfree((void *)(unsigned long)req->rw.addr);
5055 case IORING_OP_WRITEV:
5056 case IORING_OP_WRITE_FIXED:
5057 case IORING_OP_WRITE:
5058 if (io->rw.iov != io->rw.fast_iov)
5061 case IORING_OP_RECVMSG:
5062 if (req->flags & REQ_F_BUFFER_SELECTED)
5063 kfree(req->sr_msg.kbuf);
5065 case IORING_OP_SENDMSG:
5066 if (io->msg.iov != io->msg.fast_iov)
5069 case IORING_OP_RECV:
5070 if (req->flags & REQ_F_BUFFER_SELECTED)
5071 kfree(req->sr_msg.kbuf);
5073 case IORING_OP_OPENAT:
5074 case IORING_OP_OPENAT2:
5075 case IORING_OP_STATX:
5076 putname(req->open.filename);
5078 case IORING_OP_SPLICE:
5079 io_put_file(req, req->splice.file_in,
5080 (req->splice.flags & SPLICE_F_FD_IN_FIXED));
5084 req->flags &= ~REQ_F_NEED_CLEANUP;
5087 static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
5088 bool force_nonblock)
5090 struct io_ring_ctx *ctx = req->ctx;
5093 switch (req->opcode) {
5097 case IORING_OP_READV:
5098 case IORING_OP_READ_FIXED:
5099 case IORING_OP_READ:
5101 ret = io_read_prep(req, sqe, force_nonblock);
5105 ret = io_read(req, force_nonblock);
5107 case IORING_OP_WRITEV:
5108 case IORING_OP_WRITE_FIXED:
5109 case IORING_OP_WRITE:
5111 ret = io_write_prep(req, sqe, force_nonblock);
5115 ret = io_write(req, force_nonblock);
5117 case IORING_OP_FSYNC:
5119 ret = io_prep_fsync(req, sqe);
5123 ret = io_fsync(req, force_nonblock);
5125 case IORING_OP_POLL_ADD:
5127 ret = io_poll_add_prep(req, sqe);
5131 ret = io_poll_add(req);
5133 case IORING_OP_POLL_REMOVE:
5135 ret = io_poll_remove_prep(req, sqe);
5139 ret = io_poll_remove(req);
5141 case IORING_OP_SYNC_FILE_RANGE:
5143 ret = io_prep_sfr(req, sqe);
5147 ret = io_sync_file_range(req, force_nonblock);
5149 case IORING_OP_SENDMSG:
5150 case IORING_OP_SEND:
5152 ret = io_sendmsg_prep(req, sqe);
5156 if (req->opcode == IORING_OP_SENDMSG)
5157 ret = io_sendmsg(req, force_nonblock);
5159 ret = io_send(req, force_nonblock);
5161 case IORING_OP_RECVMSG:
5162 case IORING_OP_RECV:
5164 ret = io_recvmsg_prep(req, sqe);
5168 if (req->opcode == IORING_OP_RECVMSG)
5169 ret = io_recvmsg(req, force_nonblock);
5171 ret = io_recv(req, force_nonblock);
5173 case IORING_OP_TIMEOUT:
5175 ret = io_timeout_prep(req, sqe, false);
5179 ret = io_timeout(req);
5181 case IORING_OP_TIMEOUT_REMOVE:
5183 ret = io_timeout_remove_prep(req, sqe);
5187 ret = io_timeout_remove(req);
5189 case IORING_OP_ACCEPT:
5191 ret = io_accept_prep(req, sqe);
5195 ret = io_accept(req, force_nonblock);
5197 case IORING_OP_CONNECT:
5199 ret = io_connect_prep(req, sqe);
5203 ret = io_connect(req, force_nonblock);
5205 case IORING_OP_ASYNC_CANCEL:
5207 ret = io_async_cancel_prep(req, sqe);
5211 ret = io_async_cancel(req);
5213 case IORING_OP_FALLOCATE:
5215 ret = io_fallocate_prep(req, sqe);
5219 ret = io_fallocate(req, force_nonblock);
5221 case IORING_OP_OPENAT:
5223 ret = io_openat_prep(req, sqe);
5227 ret = io_openat(req, force_nonblock);
5229 case IORING_OP_CLOSE:
5231 ret = io_close_prep(req, sqe);
5235 ret = io_close(req, force_nonblock);
5237 case IORING_OP_FILES_UPDATE:
5239 ret = io_files_update_prep(req, sqe);
5243 ret = io_files_update(req, force_nonblock);
5245 case IORING_OP_STATX:
5247 ret = io_statx_prep(req, sqe);
5251 ret = io_statx(req, force_nonblock);
5253 case IORING_OP_FADVISE:
5255 ret = io_fadvise_prep(req, sqe);
5259 ret = io_fadvise(req, force_nonblock);
5261 case IORING_OP_MADVISE:
5263 ret = io_madvise_prep(req, sqe);
5267 ret = io_madvise(req, force_nonblock);
5269 case IORING_OP_OPENAT2:
5271 ret = io_openat2_prep(req, sqe);
5275 ret = io_openat2(req, force_nonblock);
5277 case IORING_OP_EPOLL_CTL:
5279 ret = io_epoll_ctl_prep(req, sqe);
5283 ret = io_epoll_ctl(req, force_nonblock);
5285 case IORING_OP_SPLICE:
5287 ret = io_splice_prep(req, sqe);
5291 ret = io_splice(req, force_nonblock);
5293 case IORING_OP_PROVIDE_BUFFERS:
5295 ret = io_provide_buffers_prep(req, sqe);
5299 ret = io_provide_buffers(req, force_nonblock);
5301 case IORING_OP_REMOVE_BUFFERS:
5303 ret = io_remove_buffers_prep(req, sqe);
5307 ret = io_remove_buffers(req, force_nonblock);
5317 if (ctx->flags & IORING_SETUP_IOPOLL) {
5318 const bool in_async = io_wq_current_is_worker();
5320 if (req->result == -EAGAIN)
5323 /* workqueue context doesn't hold uring_lock, grab it now */
5325 mutex_lock(&ctx->uring_lock);
5327 io_iopoll_req_issued(req);
5330 mutex_unlock(&ctx->uring_lock);
5336 static void io_wq_submit_work(struct io_wq_work **workptr)
5338 struct io_wq_work *work = *workptr;
5339 struct io_kiocb *req = container_of(work, struct io_kiocb, work);
5342 /* if NO_CANCEL is set, we must still run the work */
5343 if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
5344 IO_WQ_WORK_CANCEL) {
5350 ret = io_issue_sqe(req, NULL, false);
5352 * We can get EAGAIN for polled IO even though we're
5353 * forcing a sync submission from here, since we can't
5354 * wait for request slots on the block side.
5363 req_set_fail_links(req);
5364 io_cqring_add_event(req, ret);
5368 io_steal_work(req, workptr);
5371 static int io_req_needs_file(struct io_kiocb *req, int fd)
5373 if (!io_op_defs[req->opcode].needs_file)
5375 if ((fd == -1 || fd == AT_FDCWD) && io_op_defs[req->opcode].fd_non_neg)
5380 static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
5383 struct fixed_file_table *table;
5385 table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT];
5386 return table->files[index & IORING_FILE_TABLE_MASK];;
5389 static int io_file_get(struct io_submit_state *state, struct io_kiocb *req,
5390 int fd, struct file **out_file, bool fixed)
5392 struct io_ring_ctx *ctx = req->ctx;
5396 if (unlikely(!ctx->file_data ||
5397 (unsigned) fd >= ctx->nr_user_files))
5399 fd = array_index_nospec(fd, ctx->nr_user_files);
5400 file = io_file_from_index(ctx, fd);
5403 req->fixed_file_refs = ctx->file_data->cur_refs;
5404 percpu_ref_get(req->fixed_file_refs);
5406 trace_io_uring_file_get(ctx, fd);
5407 file = __io_file_get(state, fd);
5408 if (unlikely(!file))
5416 static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
5417 int fd, unsigned int flags)
5421 if (!io_req_needs_file(req, fd))
5424 fixed = (flags & IOSQE_FIXED_FILE);
5425 if (unlikely(!fixed && req->needs_fixed_file))
5428 return io_file_get(state, req, fd, &req->file, fixed);
5431 static int io_grab_files(struct io_kiocb *req)
5434 struct io_ring_ctx *ctx = req->ctx;
5436 if (req->work.files || (req->flags & REQ_F_NO_FILE_TABLE))
5438 if (!ctx->ring_file)
5442 spin_lock_irq(&ctx->inflight_lock);
5444 * We use the f_ops->flush() handler to ensure that we can flush
5445 * out work accessing these files if the fd is closed. Check if
5446 * the fd has changed since we started down this path, and disallow
5447 * this operation if it has.
5449 if (fcheck(ctx->ring_fd) == ctx->ring_file) {
5450 list_add(&req->inflight_entry, &ctx->inflight_list);
5451 req->flags |= REQ_F_INFLIGHT;
5452 req->work.files = current->files;
5455 spin_unlock_irq(&ctx->inflight_lock);
5461 static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
5463 struct io_timeout_data *data = container_of(timer,
5464 struct io_timeout_data, timer);
5465 struct io_kiocb *req = data->req;
5466 struct io_ring_ctx *ctx = req->ctx;
5467 struct io_kiocb *prev = NULL;
5468 unsigned long flags;
5470 spin_lock_irqsave(&ctx->completion_lock, flags);
5473 * We don't expect the list to be empty, that will only happen if we
5474 * race with the completion of the linked work.
5476 if (!list_empty(&req->link_list)) {
5477 prev = list_entry(req->link_list.prev, struct io_kiocb,
5479 if (refcount_inc_not_zero(&prev->refs)) {
5480 list_del_init(&req->link_list);
5481 prev->flags &= ~REQ_F_LINK_TIMEOUT;
5486 spin_unlock_irqrestore(&ctx->completion_lock, flags);
5489 req_set_fail_links(prev);
5490 io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME);
5493 io_cqring_add_event(req, -ETIME);
5496 return HRTIMER_NORESTART;
5499 static void io_queue_linked_timeout(struct io_kiocb *req)
5501 struct io_ring_ctx *ctx = req->ctx;
5504 * If the list is now empty, then our linked request finished before
5505 * we got a chance to setup the timer
5507 spin_lock_irq(&ctx->completion_lock);
5508 if (!list_empty(&req->link_list)) {
5509 struct io_timeout_data *data = &req->io->timeout;
5511 data->timer.function = io_link_timeout_fn;
5512 hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
5515 spin_unlock_irq(&ctx->completion_lock);
5517 /* drop submission reference */
5521 static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
5523 struct io_kiocb *nxt;
5525 if (!(req->flags & REQ_F_LINK_HEAD))
5527 /* for polled retry, if flag is set, we already went through here */
5528 if (req->flags & REQ_F_POLLED)
5531 nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,
5533 if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT)
5536 req->flags |= REQ_F_LINK_TIMEOUT;
5540 static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
5542 struct io_kiocb *linked_timeout;
5543 struct io_kiocb *nxt;
5544 const struct cred *old_creds = NULL;
5548 linked_timeout = io_prep_linked_timeout(req);
5550 if (req->work.creds && req->work.creds != current_cred()) {
5552 revert_creds(old_creds);
5553 if (old_creds == req->work.creds)
5554 old_creds = NULL; /* restored original creds */
5556 old_creds = override_creds(req->work.creds);
5559 ret = io_issue_sqe(req, sqe, true);
5562 * We async punt it if the file wasn't marked NOWAIT, or if the file
5563 * doesn't support non-blocking read/write attempts
5565 if (ret == -EAGAIN && (!(req->flags & REQ_F_NOWAIT) ||
5566 (req->flags & REQ_F_MUST_PUNT))) {
5567 if (io_arm_poll_handler(req)) {
5569 io_queue_linked_timeout(linked_timeout);
5573 if (io_op_defs[req->opcode].file_table) {
5574 ret = io_grab_files(req);
5580 * Queued up for async execution, worker will release
5581 * submit reference when the iocb is actually submitted.
5583 io_queue_async_work(req);
5589 /* drop submission reference */
5590 io_put_req_find_next(req, &nxt);
5592 if (linked_timeout) {
5594 io_queue_linked_timeout(linked_timeout);
5596 io_put_req(linked_timeout);
5599 /* and drop final reference, if we failed */
5601 io_cqring_add_event(req, ret);
5602 req_set_fail_links(req);
5608 if (req->flags & REQ_F_FORCE_ASYNC)
5614 revert_creds(old_creds);
5617 static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
5621 ret = io_req_defer(req, sqe);
5623 if (ret != -EIOCBQUEUED) {
5625 io_cqring_add_event(req, ret);
5626 req_set_fail_links(req);
5627 io_double_put_req(req);
5629 } else if (req->flags & REQ_F_FORCE_ASYNC) {
5630 ret = io_req_defer_prep(req, sqe);
5631 if (unlikely(ret < 0))
5634 * Never try inline submit of IOSQE_ASYNC is set, go straight
5635 * to async execution.
5637 req->work.flags |= IO_WQ_WORK_CONCURRENT;
5638 io_queue_async_work(req);
5640 __io_queue_sqe(req, sqe);
5644 static inline void io_queue_link_head(struct io_kiocb *req)
5646 if (unlikely(req->flags & REQ_F_FAIL_LINK)) {
5647 io_cqring_add_event(req, -ECANCELED);
5648 io_double_put_req(req);
5650 io_queue_sqe(req, NULL);
5653 static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
5654 struct io_submit_state *state, struct io_kiocb **link)
5656 struct io_ring_ctx *ctx = req->ctx;
5660 * If we already have a head request, queue this one for async
5661 * submittal once the head completes. If we don't have a head but
5662 * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
5663 * submitted sync once the chain is complete. If none of those
5664 * conditions are true (normal request), then just queue it.
5667 struct io_kiocb *head = *link;
5670 * Taking sequential execution of a link, draining both sides
5671 * of the link also fullfils IOSQE_IO_DRAIN semantics for all
5672 * requests in the link. So, it drains the head and the
5673 * next after the link request. The last one is done via
5674 * drain_next flag to persist the effect across calls.
5676 if (req->flags & REQ_F_IO_DRAIN) {
5677 head->flags |= REQ_F_IO_DRAIN;
5678 ctx->drain_next = 1;
5680 if (io_alloc_async_ctx(req))
5683 ret = io_req_defer_prep(req, sqe);
5685 /* fail even hard links since we don't submit */
5686 head->flags |= REQ_F_FAIL_LINK;
5689 trace_io_uring_link(ctx, req, head);
5690 list_add_tail(&req->link_list, &head->link_list);
5692 /* last request of a link, enqueue the link */
5693 if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
5694 io_queue_link_head(head);
5698 if (unlikely(ctx->drain_next)) {
5699 req->flags |= REQ_F_IO_DRAIN;
5700 ctx->drain_next = 0;
5702 if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
5703 req->flags |= REQ_F_LINK_HEAD;
5704 INIT_LIST_HEAD(&req->link_list);
5706 if (io_alloc_async_ctx(req))
5709 ret = io_req_defer_prep(req, sqe);
5711 req->flags |= REQ_F_FAIL_LINK;
5714 io_queue_sqe(req, sqe);
5722 * Batched submission is done, ensure local IO is flushed out.
5724 static void io_submit_state_end(struct io_submit_state *state)
5726 blk_finish_plug(&state->plug);
5728 if (state->free_reqs)
5729 kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
5733 * Start submission side cache.
5735 static void io_submit_state_start(struct io_submit_state *state,
5736 unsigned int max_ios)
5738 blk_start_plug(&state->plug);
5739 state->free_reqs = 0;
5741 state->ios_left = max_ios;
5744 static void io_commit_sqring(struct io_ring_ctx *ctx)
5746 struct io_rings *rings = ctx->rings;
5749 * Ensure any loads from the SQEs are done at this point,
5750 * since once we write the new head, the application could
5751 * write new data to them.
5753 smp_store_release(&rings->sq.head, ctx->cached_sq_head);
5757 * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory
5758 * that is mapped by userspace. This means that care needs to be taken to
5759 * ensure that reads are stable, as we cannot rely on userspace always
5760 * being a good citizen. If members of the sqe are validated and then later
5761 * used, it's important that those reads are done through READ_ONCE() to
5762 * prevent a re-load down the line.
5764 static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
5766 u32 *sq_array = ctx->sq_array;
5770 * The cached sq head (or cq tail) serves two purposes:
5772 * 1) allows us to batch the cost of updating the user visible
5774 * 2) allows the kernel side to track the head on its own, even
5775 * though the application is the one updating it.
5777 head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]);
5778 if (likely(head < ctx->sq_entries))
5779 return &ctx->sq_sqes[head];
5781 /* drop invalid entries */
5782 ctx->cached_sq_dropped++;
5783 WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped);
5787 static inline void io_consume_sqe(struct io_ring_ctx *ctx)
5789 ctx->cached_sq_head++;
5792 #define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
5793 IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
5794 IOSQE_BUFFER_SELECT)
5796 static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
5797 const struct io_uring_sqe *sqe,
5798 struct io_submit_state *state, bool async)
5800 unsigned int sqe_flags;
5804 * All io need record the previous position, if LINK vs DARIN,
5805 * it can be used to mark the position of the first IO in the
5808 req->sequence = ctx->cached_sq_head - ctx->cached_sq_dropped;
5809 req->opcode = READ_ONCE(sqe->opcode);
5810 req->user_data = READ_ONCE(sqe->user_data);
5815 /* one is dropped after submission, the other at completion */
5816 refcount_set(&req->refs, 2);
5819 req->needs_fixed_file = async;
5820 INIT_IO_WORK(&req->work, io_wq_submit_work);
5822 if (unlikely(req->opcode >= IORING_OP_LAST))
5825 if (io_op_defs[req->opcode].needs_mm && !current->mm) {
5826 if (unlikely(!mmget_not_zero(ctx->sqo_mm)))
5828 use_mm(ctx->sqo_mm);
5831 sqe_flags = READ_ONCE(sqe->flags);
5832 /* enforce forwards compatibility on users */
5833 if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
5836 if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
5837 !io_op_defs[req->opcode].buffer_select)
5840 id = READ_ONCE(sqe->personality);
5842 req->work.creds = idr_find(&ctx->personality_idr, id);
5843 if (unlikely(!req->work.creds))
5845 get_cred(req->work.creds);
5848 /* same numerical values with corresponding REQ_F_*, safe to copy */
5849 req->flags |= sqe_flags & (IOSQE_IO_DRAIN | IOSQE_IO_HARDLINK |
5850 IOSQE_ASYNC | IOSQE_FIXED_FILE |
5851 IOSQE_BUFFER_SELECT | IOSQE_IO_LINK);
5853 fd = READ_ONCE(sqe->fd);
5854 return io_req_set_file(state, req, fd, sqe_flags);
5857 static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
5858 struct file *ring_file, int ring_fd, bool async)
5860 struct io_submit_state state, *statep = NULL;
5861 struct io_kiocb *link = NULL;
5862 int i, submitted = 0;
5864 /* if we have a backlog and couldn't flush it all, return BUSY */
5865 if (test_bit(0, &ctx->sq_check_overflow)) {
5866 if (!list_empty(&ctx->cq_overflow_list) &&
5867 !io_cqring_overflow_flush(ctx, false))
5871 /* make sure SQ entry isn't read before tail */
5872 nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
5874 if (!percpu_ref_tryget_many(&ctx->refs, nr))
5877 if (nr > IO_PLUG_THRESHOLD) {
5878 io_submit_state_start(&state, nr);
5882 ctx->ring_fd = ring_fd;
5883 ctx->ring_file = ring_file;
5885 for (i = 0; i < nr; i++) {
5886 const struct io_uring_sqe *sqe;
5887 struct io_kiocb *req;
5890 sqe = io_get_sqe(ctx);
5891 if (unlikely(!sqe)) {
5892 io_consume_sqe(ctx);
5895 req = io_alloc_req(ctx, statep);
5896 if (unlikely(!req)) {
5898 submitted = -EAGAIN;
5902 err = io_init_req(ctx, req, sqe, statep, async);
5903 io_consume_sqe(ctx);
5904 /* will complete beyond this point, count as submitted */
5907 if (unlikely(err)) {
5909 io_cqring_add_event(req, err);
5910 io_double_put_req(req);
5914 trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data,
5916 err = io_submit_sqe(req, sqe, statep, &link);
5921 if (unlikely(submitted != nr)) {
5922 int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
5924 percpu_ref_put_many(&ctx->refs, nr - ref_used);
5927 io_queue_link_head(link);
5929 io_submit_state_end(&state);
5931 /* Commit SQ ring head once we've consumed and submitted all SQEs */
5932 io_commit_sqring(ctx);
5937 static inline void io_sq_thread_drop_mm(struct io_ring_ctx *ctx)
5939 struct mm_struct *mm = current->mm;
5947 static int io_sq_thread(void *data)
5949 struct io_ring_ctx *ctx = data;
5950 const struct cred *old_cred;
5951 mm_segment_t old_fs;
5953 unsigned long timeout;
5956 complete(&ctx->completions[1]);
5960 old_cred = override_creds(ctx->creds);
5962 timeout = jiffies + ctx->sq_thread_idle;
5963 while (!kthread_should_park()) {
5964 unsigned int to_submit;
5966 if (!list_empty(&ctx->poll_list)) {
5967 unsigned nr_events = 0;
5969 mutex_lock(&ctx->uring_lock);
5970 if (!list_empty(&ctx->poll_list))
5971 io_iopoll_getevents(ctx, &nr_events, 0);
5973 timeout = jiffies + ctx->sq_thread_idle;
5974 mutex_unlock(&ctx->uring_lock);
5977 to_submit = io_sqring_entries(ctx);
5980 * If submit got -EBUSY, flag us as needing the application
5981 * to enter the kernel to reap and flush events.
5983 if (!to_submit || ret == -EBUSY) {
5985 * Drop cur_mm before scheduling, we can't hold it for
5986 * long periods (or over schedule()). Do this before
5987 * adding ourselves to the waitqueue, as the unuse/drop
5990 io_sq_thread_drop_mm(ctx);
5993 * We're polling. If we're within the defined idle
5994 * period, then let us spin without work before going
5995 * to sleep. The exception is if we got EBUSY doing
5996 * more IO, we should wait for the application to
5997 * reap events and wake us up.
5999 if (!list_empty(&ctx->poll_list) ||
6000 (!time_after(jiffies, timeout) && ret != -EBUSY &&
6001 !percpu_ref_is_dying(&ctx->refs))) {
6002 if (current->task_works)
6008 prepare_to_wait(&ctx->sqo_wait, &wait,
6009 TASK_INTERRUPTIBLE);
6012 * While doing polled IO, before going to sleep, we need
6013 * to check if there are new reqs added to poll_list, it
6014 * is because reqs may have been punted to io worker and
6015 * will be added to poll_list later, hence check the
6018 if ((ctx->flags & IORING_SETUP_IOPOLL) &&
6019 !list_empty_careful(&ctx->poll_list)) {
6020 finish_wait(&ctx->sqo_wait, &wait);
6024 /* Tell userspace we may need a wakeup call */
6025 ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
6026 /* make sure to read SQ tail after writing flags */
6029 to_submit = io_sqring_entries(ctx);
6030 if (!to_submit || ret == -EBUSY) {
6031 if (kthread_should_park()) {
6032 finish_wait(&ctx->sqo_wait, &wait);
6035 if (current->task_works) {
6037 finish_wait(&ctx->sqo_wait, &wait);
6040 if (signal_pending(current))
6041 flush_signals(current);
6043 finish_wait(&ctx->sqo_wait, &wait);
6045 ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
6048 finish_wait(&ctx->sqo_wait, &wait);
6050 ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
6053 mutex_lock(&ctx->uring_lock);
6054 ret = io_submit_sqes(ctx, to_submit, NULL, -1, true);
6055 mutex_unlock(&ctx->uring_lock);
6056 timeout = jiffies + ctx->sq_thread_idle;
6059 if (current->task_works)
6063 io_sq_thread_drop_mm(ctx);
6064 revert_creds(old_cred);
6071 struct io_wait_queue {
6072 struct wait_queue_entry wq;
6073 struct io_ring_ctx *ctx;
6075 unsigned nr_timeouts;
6078 static inline bool io_should_wake(struct io_wait_queue *iowq, bool noflush)
6080 struct io_ring_ctx *ctx = iowq->ctx;
6083 * Wake up if we have enough events, or if a timeout occurred since we
6084 * started waiting. For timeouts, we always want to return to userspace,
6085 * regardless of event count.
6087 return io_cqring_events(ctx, noflush) >= iowq->to_wait ||
6088 atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
6091 static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
6092 int wake_flags, void *key)
6094 struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
6097 /* use noflush == true, as we can't safely rely on locking context */
6098 if (!io_should_wake(iowq, true))
6101 return autoremove_wake_function(curr, mode, wake_flags, key);
6105 * Wait until events become available, if we don't already have some. The
6106 * application must reap them itself, as they reside on the shared cq ring.
6108 static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
6109 const sigset_t __user *sig, size_t sigsz)
6111 struct io_wait_queue iowq = {
6114 .func = io_wake_function,
6115 .entry = LIST_HEAD_INIT(iowq.wq.entry),
6118 .to_wait = min_events,
6120 struct io_rings *rings = ctx->rings;
6124 if (io_cqring_events(ctx, false) >= min_events)
6126 if (!current->task_works)
6132 #ifdef CONFIG_COMPAT
6133 if (in_compat_syscall())
6134 ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
6138 ret = set_user_sigmask(sig, sigsz);
6144 iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
6145 trace_io_uring_cqring_wait(ctx, min_events);
6147 prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
6148 TASK_INTERRUPTIBLE);
6149 if (current->task_works)
6151 if (io_should_wake(&iowq, false))
6154 if (signal_pending(current)) {
6159 finish_wait(&ctx->wait, &iowq.wq);
6161 restore_saved_sigmask_unless(ret == -EINTR);
6163 return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
6166 static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
6168 #if defined(CONFIG_UNIX)
6169 if (ctx->ring_sock) {
6170 struct sock *sock = ctx->ring_sock->sk;
6171 struct sk_buff *skb;
6173 while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
6179 for (i = 0; i < ctx->nr_user_files; i++) {
6182 file = io_file_from_index(ctx, i);
6189 static void io_file_ref_kill(struct percpu_ref *ref)
6191 struct fixed_file_data *data;
6193 data = container_of(ref, struct fixed_file_data, refs);
6194 complete(&data->done);
6197 static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
6199 struct fixed_file_data *data = ctx->file_data;
6200 struct fixed_file_ref_node *ref_node = NULL;
6201 unsigned nr_tables, i;
6202 unsigned long flags;
6207 spin_lock_irqsave(&data->lock, flags);
6208 if (!list_empty(&data->ref_list))
6209 ref_node = list_first_entry(&data->ref_list,
6210 struct fixed_file_ref_node, node);
6211 spin_unlock_irqrestore(&data->lock, flags);
6213 percpu_ref_kill(&ref_node->refs);
6215 percpu_ref_kill(&data->refs);
6217 /* wait for all refs nodes to complete */
6218 wait_for_completion(&data->done);
6220 __io_sqe_files_unregister(ctx);
6221 nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
6222 for (i = 0; i < nr_tables; i++)
6223 kfree(data->table[i].files);
6225 percpu_ref_exit(&data->refs);
6227 ctx->file_data = NULL;
6228 ctx->nr_user_files = 0;
6232 static void io_sq_thread_stop(struct io_ring_ctx *ctx)
6234 if (ctx->sqo_thread) {
6235 wait_for_completion(&ctx->completions[1]);
6237 * The park is a bit of a work-around, without it we get
6238 * warning spews on shutdown with SQPOLL set and affinity
6239 * set to a single CPU.
6241 kthread_park(ctx->sqo_thread);
6242 kthread_stop(ctx->sqo_thread);
6243 ctx->sqo_thread = NULL;
6247 static void io_finish_async(struct io_ring_ctx *ctx)
6249 io_sq_thread_stop(ctx);
6252 io_wq_destroy(ctx->io_wq);
6257 #if defined(CONFIG_UNIX)
6259 * Ensure the UNIX gc is aware of our file set, so we are certain that
6260 * the io_uring can be safely unregistered on process exit, even if we have
6261 * loops in the file referencing.
6263 static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
6265 struct sock *sk = ctx->ring_sock->sk;
6266 struct scm_fp_list *fpl;
6267 struct sk_buff *skb;
6270 fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
6274 skb = alloc_skb(0, GFP_KERNEL);
6283 fpl->user = get_uid(ctx->user);
6284 for (i = 0; i < nr; i++) {
6285 struct file *file = io_file_from_index(ctx, i + offset);
6289 fpl->fp[nr_files] = get_file(file);
6290 unix_inflight(fpl->user, fpl->fp[nr_files]);
6295 fpl->max = SCM_MAX_FD;
6296 fpl->count = nr_files;
6297 UNIXCB(skb).fp = fpl;
6298 skb->destructor = unix_destruct_scm;
6299 refcount_add(skb->truesize, &sk->sk_wmem_alloc);
6300 skb_queue_head(&sk->sk_receive_queue, skb);
6302 for (i = 0; i < nr_files; i++)
6313 * If UNIX sockets are enabled, fd passing can cause a reference cycle which
6314 * causes regular reference counting to break down. We rely on the UNIX
6315 * garbage collection to take care of this problem for us.
6317 static int io_sqe_files_scm(struct io_ring_ctx *ctx)
6319 unsigned left, total;
6323 left = ctx->nr_user_files;
6325 unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
6327 ret = __io_sqe_files_scm(ctx, this_files, total);
6331 total += this_files;
6337 while (total < ctx->nr_user_files) {
6338 struct file *file = io_file_from_index(ctx, total);
6348 static int io_sqe_files_scm(struct io_ring_ctx *ctx)
6354 static int io_sqe_alloc_file_tables(struct io_ring_ctx *ctx, unsigned nr_tables,
6359 for (i = 0; i < nr_tables; i++) {
6360 struct fixed_file_table *table = &ctx->file_data->table[i];
6361 unsigned this_files;
6363 this_files = min(nr_files, IORING_MAX_FILES_TABLE);
6364 table->files = kcalloc(this_files, sizeof(struct file *),
6368 nr_files -= this_files;
6374 for (i = 0; i < nr_tables; i++) {
6375 struct fixed_file_table *table = &ctx->file_data->table[i];
6376 kfree(table->files);
6381 static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file)
6383 #if defined(CONFIG_UNIX)
6384 struct sock *sock = ctx->ring_sock->sk;
6385 struct sk_buff_head list, *head = &sock->sk_receive_queue;
6386 struct sk_buff *skb;
6389 __skb_queue_head_init(&list);
6392 * Find the skb that holds this file in its SCM_RIGHTS. When found,
6393 * remove this entry and rearrange the file array.
6395 skb = skb_dequeue(head);
6397 struct scm_fp_list *fp;
6399 fp = UNIXCB(skb).fp;
6400 for (i = 0; i < fp->count; i++) {
6403 if (fp->fp[i] != file)
6406 unix_notinflight(fp->user, fp->fp[i]);
6407 left = fp->count - 1 - i;
6409 memmove(&fp->fp[i], &fp->fp[i + 1],
6410 left * sizeof(struct file *));
6417 __skb_queue_tail(&list, skb);
6427 __skb_queue_tail(&list, skb);
6429 skb = skb_dequeue(head);
6432 if (skb_peek(&list)) {
6433 spin_lock_irq(&head->lock);
6434 while ((skb = __skb_dequeue(&list)) != NULL)
6435 __skb_queue_tail(head, skb);
6436 spin_unlock_irq(&head->lock);
6443 struct io_file_put {
6444 struct list_head list;
6448 static void io_file_put_work(struct work_struct *work)
6450 struct fixed_file_ref_node *ref_node;
6451 struct fixed_file_data *file_data;
6452 struct io_ring_ctx *ctx;
6453 struct io_file_put *pfile, *tmp;
6454 unsigned long flags;
6456 ref_node = container_of(work, struct fixed_file_ref_node, work);
6457 file_data = ref_node->file_data;
6458 ctx = file_data->ctx;
6460 list_for_each_entry_safe(pfile, tmp, &ref_node->file_list, list) {
6461 list_del_init(&pfile->list);
6462 io_ring_file_put(ctx, pfile->file);
6466 spin_lock_irqsave(&file_data->lock, flags);
6467 list_del_init(&ref_node->node);
6468 spin_unlock_irqrestore(&file_data->lock, flags);
6470 percpu_ref_exit(&ref_node->refs);
6472 percpu_ref_put(&file_data->refs);
6475 static void io_file_data_ref_zero(struct percpu_ref *ref)
6477 struct fixed_file_ref_node *ref_node;
6479 ref_node = container_of(ref, struct fixed_file_ref_node, refs);
6481 queue_work(system_wq, &ref_node->work);
6484 static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
6485 struct io_ring_ctx *ctx)
6487 struct fixed_file_ref_node *ref_node;
6489 ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
6491 return ERR_PTR(-ENOMEM);
6493 if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero,
6496 return ERR_PTR(-ENOMEM);
6498 INIT_LIST_HEAD(&ref_node->node);
6499 INIT_LIST_HEAD(&ref_node->file_list);
6500 INIT_WORK(&ref_node->work, io_file_put_work);
6501 ref_node->file_data = ctx->file_data;
6506 static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node)
6508 percpu_ref_exit(&ref_node->refs);
6512 static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
6515 __s32 __user *fds = (__s32 __user *) arg;
6520 struct fixed_file_ref_node *ref_node;
6521 unsigned long flags;
6527 if (nr_args > IORING_MAX_FIXED_FILES)
6530 ctx->file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL);
6531 if (!ctx->file_data)
6533 ctx->file_data->ctx = ctx;
6534 init_completion(&ctx->file_data->done);
6535 INIT_LIST_HEAD(&ctx->file_data->ref_list);
6536 spin_lock_init(&ctx->file_data->lock);
6538 nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
6539 ctx->file_data->table = kcalloc(nr_tables,
6540 sizeof(struct fixed_file_table),
6542 if (!ctx->file_data->table) {
6543 kfree(ctx->file_data);
6544 ctx->file_data = NULL;
6548 if (percpu_ref_init(&ctx->file_data->refs, io_file_ref_kill,
6549 PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) {
6550 kfree(ctx->file_data->table);
6551 kfree(ctx->file_data);
6552 ctx->file_data = NULL;
6556 if (io_sqe_alloc_file_tables(ctx, nr_tables, nr_args)) {
6557 percpu_ref_exit(&ctx->file_data->refs);
6558 kfree(ctx->file_data->table);
6559 kfree(ctx->file_data);
6560 ctx->file_data = NULL;
6564 for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
6565 struct fixed_file_table *table;
6569 if (copy_from_user(&fd, &fds[i], sizeof(fd)))
6571 /* allow sparse sets */
6577 table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
6578 index = i & IORING_FILE_TABLE_MASK;
6586 * Don't allow io_uring instances to be registered. If UNIX
6587 * isn't enabled, then this causes a reference cycle and this
6588 * instance can never get freed. If UNIX is enabled we'll
6589 * handle it just fine, but there's still no point in allowing
6590 * a ring fd as it doesn't support regular read/write anyway.
6592 if (file->f_op == &io_uring_fops) {
6597 table->files[index] = file;
6601 for (i = 0; i < ctx->nr_user_files; i++) {
6602 file = io_file_from_index(ctx, i);
6606 for (i = 0; i < nr_tables; i++)
6607 kfree(ctx->file_data->table[i].files);
6609 kfree(ctx->file_data->table);
6610 kfree(ctx->file_data);
6611 ctx->file_data = NULL;
6612 ctx->nr_user_files = 0;
6616 ret = io_sqe_files_scm(ctx);
6618 io_sqe_files_unregister(ctx);
6622 ref_node = alloc_fixed_file_ref_node(ctx);
6623 if (IS_ERR(ref_node)) {
6624 io_sqe_files_unregister(ctx);
6625 return PTR_ERR(ref_node);
6628 ctx->file_data->cur_refs = &ref_node->refs;
6629 spin_lock_irqsave(&ctx->file_data->lock, flags);
6630 list_add(&ref_node->node, &ctx->file_data->ref_list);
6631 spin_unlock_irqrestore(&ctx->file_data->lock, flags);
6632 percpu_ref_get(&ctx->file_data->refs);
6636 static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
6639 #if defined(CONFIG_UNIX)
6640 struct sock *sock = ctx->ring_sock->sk;
6641 struct sk_buff_head *head = &sock->sk_receive_queue;
6642 struct sk_buff *skb;
6645 * See if we can merge this file into an existing skb SCM_RIGHTS
6646 * file set. If there's no room, fall back to allocating a new skb
6647 * and filling it in.
6649 spin_lock_irq(&head->lock);
6650 skb = skb_peek(head);
6652 struct scm_fp_list *fpl = UNIXCB(skb).fp;
6654 if (fpl->count < SCM_MAX_FD) {
6655 __skb_unlink(skb, head);
6656 spin_unlock_irq(&head->lock);
6657 fpl->fp[fpl->count] = get_file(file);
6658 unix_inflight(fpl->user, fpl->fp[fpl->count]);
6660 spin_lock_irq(&head->lock);
6661 __skb_queue_head(head, skb);
6666 spin_unlock_irq(&head->lock);
6673 return __io_sqe_files_scm(ctx, 1, index);
6679 static int io_queue_file_removal(struct fixed_file_data *data,
6682 struct io_file_put *pfile;
6683 struct percpu_ref *refs = data->cur_refs;
6684 struct fixed_file_ref_node *ref_node;
6686 pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
6690 ref_node = container_of(refs, struct fixed_file_ref_node, refs);
6692 list_add(&pfile->list, &ref_node->file_list);
6697 static int __io_sqe_files_update(struct io_ring_ctx *ctx,
6698 struct io_uring_files_update *up,
6701 struct fixed_file_data *data = ctx->file_data;
6702 struct fixed_file_ref_node *ref_node;
6707 unsigned long flags;
6708 bool needs_switch = false;
6710 if (check_add_overflow(up->offset, nr_args, &done))
6712 if (done > ctx->nr_user_files)
6715 ref_node = alloc_fixed_file_ref_node(ctx);
6716 if (IS_ERR(ref_node))
6717 return PTR_ERR(ref_node);
6720 fds = u64_to_user_ptr(up->fds);
6722 struct fixed_file_table *table;
6726 if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
6730 i = array_index_nospec(up->offset, ctx->nr_user_files);
6731 table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
6732 index = i & IORING_FILE_TABLE_MASK;
6733 if (table->files[index]) {
6734 file = io_file_from_index(ctx, index);
6735 err = io_queue_file_removal(data, file);
6738 table->files[index] = NULL;
6739 needs_switch = true;
6748 * Don't allow io_uring instances to be registered. If
6749 * UNIX isn't enabled, then this causes a reference
6750 * cycle and this instance can never get freed. If UNIX
6751 * is enabled we'll handle it just fine, but there's
6752 * still no point in allowing a ring fd as it doesn't
6753 * support regular read/write anyway.
6755 if (file->f_op == &io_uring_fops) {
6760 table->files[index] = file;
6761 err = io_sqe_file_register(ctx, file, i);
6771 percpu_ref_kill(data->cur_refs);
6772 spin_lock_irqsave(&data->lock, flags);
6773 list_add(&ref_node->node, &data->ref_list);
6774 data->cur_refs = &ref_node->refs;
6775 spin_unlock_irqrestore(&data->lock, flags);
6776 percpu_ref_get(&ctx->file_data->refs);
6778 destroy_fixed_file_ref_node(ref_node);
6780 return done ? done : err;
6783 static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
6786 struct io_uring_files_update up;
6788 if (!ctx->file_data)
6792 if (copy_from_user(&up, arg, sizeof(up)))
6797 return __io_sqe_files_update(ctx, &up, nr_args);
6800 static void io_free_work(struct io_wq_work *work)
6802 struct io_kiocb *req = container_of(work, struct io_kiocb, work);
6804 /* Consider that io_steal_work() relies on this ref */
6808 static int io_init_wq_offload(struct io_ring_ctx *ctx,
6809 struct io_uring_params *p)
6811 struct io_wq_data data;
6813 struct io_ring_ctx *ctx_attach;
6814 unsigned int concurrency;
6817 data.user = ctx->user;
6818 data.free_work = io_free_work;
6820 if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {
6821 /* Do QD, or 4 * CPUS, whatever is smallest */
6822 concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
6824 ctx->io_wq = io_wq_create(concurrency, &data);
6825 if (IS_ERR(ctx->io_wq)) {
6826 ret = PTR_ERR(ctx->io_wq);
6832 f = fdget(p->wq_fd);
6836 if (f.file->f_op != &io_uring_fops) {
6841 ctx_attach = f.file->private_data;
6842 /* @io_wq is protected by holding the fd */
6843 if (!io_wq_get(ctx_attach->io_wq, &data)) {
6848 ctx->io_wq = ctx_attach->io_wq;
6854 static int io_sq_offload_start(struct io_ring_ctx *ctx,
6855 struct io_uring_params *p)
6859 init_waitqueue_head(&ctx->sqo_wait);
6860 mmgrab(current->mm);
6861 ctx->sqo_mm = current->mm;
6863 if (ctx->flags & IORING_SETUP_SQPOLL) {
6865 if (!capable(CAP_SYS_ADMIN))
6868 ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
6869 if (!ctx->sq_thread_idle)
6870 ctx->sq_thread_idle = HZ;
6872 if (p->flags & IORING_SETUP_SQ_AFF) {
6873 int cpu = p->sq_thread_cpu;
6876 if (cpu >= nr_cpu_ids)
6878 if (!cpu_online(cpu))
6881 ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread,
6885 ctx->sqo_thread = kthread_create(io_sq_thread, ctx,
6888 if (IS_ERR(ctx->sqo_thread)) {
6889 ret = PTR_ERR(ctx->sqo_thread);
6890 ctx->sqo_thread = NULL;
6893 wake_up_process(ctx->sqo_thread);
6894 } else if (p->flags & IORING_SETUP_SQ_AFF) {
6895 /* Can't have SQ_AFF without SQPOLL */
6900 ret = io_init_wq_offload(ctx, p);
6906 io_finish_async(ctx);
6907 mmdrop(ctx->sqo_mm);
6912 static void io_unaccount_mem(struct user_struct *user, unsigned long nr_pages)
6914 atomic_long_sub(nr_pages, &user->locked_vm);
6917 static int io_account_mem(struct user_struct *user, unsigned long nr_pages)
6919 unsigned long page_limit, cur_pages, new_pages;
6921 /* Don't allow more pages than we can safely lock */
6922 page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
6925 cur_pages = atomic_long_read(&user->locked_vm);
6926 new_pages = cur_pages + nr_pages;
6927 if (new_pages > page_limit)
6929 } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
6930 new_pages) != cur_pages);
6935 static void io_mem_free(void *ptr)
6942 page = virt_to_head_page(ptr);
6943 if (put_page_testzero(page))
6944 free_compound_page(page);
6947 static void *io_mem_alloc(size_t size)
6949 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
6952 return (void *) __get_free_pages(gfp_flags, get_order(size));
6955 static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
6958 struct io_rings *rings;
6959 size_t off, sq_array_size;
6961 off = struct_size(rings, cqes, cq_entries);
6962 if (off == SIZE_MAX)
6966 off = ALIGN(off, SMP_CACHE_BYTES);
6971 sq_array_size = array_size(sizeof(u32), sq_entries);
6972 if (sq_array_size == SIZE_MAX)
6975 if (check_add_overflow(off, sq_array_size, &off))
6984 static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
6988 pages = (size_t)1 << get_order(
6989 rings_size(sq_entries, cq_entries, NULL));
6990 pages += (size_t)1 << get_order(
6991 array_size(sizeof(struct io_uring_sqe), sq_entries));
6996 static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
7000 if (!ctx->user_bufs)
7003 for (i = 0; i < ctx->nr_user_bufs; i++) {
7004 struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
7006 for (j = 0; j < imu->nr_bvecs; j++)
7007 unpin_user_page(imu->bvec[j].bv_page);
7009 if (ctx->account_mem)
7010 io_unaccount_mem(ctx->user, imu->nr_bvecs);
7015 kfree(ctx->user_bufs);
7016 ctx->user_bufs = NULL;
7017 ctx->nr_user_bufs = 0;
7021 static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
7022 void __user *arg, unsigned index)
7024 struct iovec __user *src;
7026 #ifdef CONFIG_COMPAT
7028 struct compat_iovec __user *ciovs;
7029 struct compat_iovec ciov;
7031 ciovs = (struct compat_iovec __user *) arg;
7032 if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
7035 dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
7036 dst->iov_len = ciov.iov_len;
7040 src = (struct iovec __user *) arg;
7041 if (copy_from_user(dst, &src[index], sizeof(*dst)))
7046 static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
7049 struct vm_area_struct **vmas = NULL;
7050 struct page **pages = NULL;
7051 int i, j, got_pages = 0;
7056 if (!nr_args || nr_args > UIO_MAXIOV)
7059 ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
7061 if (!ctx->user_bufs)
7064 for (i = 0; i < nr_args; i++) {
7065 struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
7066 unsigned long off, start, end, ubuf;
7071 ret = io_copy_iov(ctx, &iov, arg, i);
7076 * Don't impose further limits on the size and buffer
7077 * constraints here, we'll -EINVAL later when IO is
7078 * submitted if they are wrong.
7081 if (!iov.iov_base || !iov.iov_len)
7084 /* arbitrary limit, but we need something */
7085 if (iov.iov_len > SZ_1G)
7088 ubuf = (unsigned long) iov.iov_base;
7089 end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
7090 start = ubuf >> PAGE_SHIFT;
7091 nr_pages = end - start;
7093 if (ctx->account_mem) {
7094 ret = io_account_mem(ctx->user, nr_pages);
7100 if (!pages || nr_pages > got_pages) {
7103 pages = kvmalloc_array(nr_pages, sizeof(struct page *),
7105 vmas = kvmalloc_array(nr_pages,
7106 sizeof(struct vm_area_struct *),
7108 if (!pages || !vmas) {
7110 if (ctx->account_mem)
7111 io_unaccount_mem(ctx->user, nr_pages);
7114 got_pages = nr_pages;
7117 imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
7121 if (ctx->account_mem)
7122 io_unaccount_mem(ctx->user, nr_pages);
7127 down_read(¤t->mm->mmap_sem);
7128 pret = pin_user_pages(ubuf, nr_pages,
7129 FOLL_WRITE | FOLL_LONGTERM,
7131 if (pret == nr_pages) {
7132 /* don't support file backed memory */
7133 for (j = 0; j < nr_pages; j++) {
7134 struct vm_area_struct *vma = vmas[j];
7137 !is_file_hugepages(vma->vm_file)) {
7143 ret = pret < 0 ? pret : -EFAULT;
7145 up_read(¤t->mm->mmap_sem);
7148 * if we did partial map, or found file backed vmas,
7149 * release any pages we did get
7152 unpin_user_pages(pages, pret);
7153 if (ctx->account_mem)
7154 io_unaccount_mem(ctx->user, nr_pages);
7159 off = ubuf & ~PAGE_MASK;
7161 for (j = 0; j < nr_pages; j++) {
7164 vec_len = min_t(size_t, size, PAGE_SIZE - off);
7165 imu->bvec[j].bv_page = pages[j];
7166 imu->bvec[j].bv_len = vec_len;
7167 imu->bvec[j].bv_offset = off;
7171 /* store original address for later verification */
7173 imu->len = iov.iov_len;
7174 imu->nr_bvecs = nr_pages;
7176 ctx->nr_user_bufs++;
7184 io_sqe_buffer_unregister(ctx);
7188 static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
7190 __s32 __user *fds = arg;
7196 if (copy_from_user(&fd, fds, sizeof(*fds)))
7199 ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
7200 if (IS_ERR(ctx->cq_ev_fd)) {
7201 int ret = PTR_ERR(ctx->cq_ev_fd);
7202 ctx->cq_ev_fd = NULL;
7209 static int io_eventfd_unregister(struct io_ring_ctx *ctx)
7211 if (ctx->cq_ev_fd) {
7212 eventfd_ctx_put(ctx->cq_ev_fd);
7213 ctx->cq_ev_fd = NULL;
7220 static int __io_destroy_buffers(int id, void *p, void *data)
7222 struct io_ring_ctx *ctx = data;
7223 struct io_buffer *buf = p;
7225 __io_remove_buffers(ctx, buf, id, -1U);
7229 static void io_destroy_buffers(struct io_ring_ctx *ctx)
7231 idr_for_each(&ctx->io_buffer_idr, __io_destroy_buffers, ctx);
7232 idr_destroy(&ctx->io_buffer_idr);
7235 static void io_ring_ctx_free(struct io_ring_ctx *ctx)
7237 io_finish_async(ctx);
7239 mmdrop(ctx->sqo_mm);
7241 io_iopoll_reap_events(ctx);
7242 io_sqe_buffer_unregister(ctx);
7243 io_sqe_files_unregister(ctx);
7244 io_eventfd_unregister(ctx);
7245 io_destroy_buffers(ctx);
7246 idr_destroy(&ctx->personality_idr);
7248 #if defined(CONFIG_UNIX)
7249 if (ctx->ring_sock) {
7250 ctx->ring_sock->file = NULL; /* so that iput() is called */
7251 sock_release(ctx->ring_sock);
7255 io_mem_free(ctx->rings);
7256 io_mem_free(ctx->sq_sqes);
7258 percpu_ref_exit(&ctx->refs);
7259 if (ctx->account_mem)
7260 io_unaccount_mem(ctx->user,
7261 ring_pages(ctx->sq_entries, ctx->cq_entries));
7262 free_uid(ctx->user);
7263 put_cred(ctx->creds);
7264 kfree(ctx->completions);
7265 kfree(ctx->cancel_hash);
7266 kmem_cache_free(req_cachep, ctx->fallback_req);
7270 static __poll_t io_uring_poll(struct file *file, poll_table *wait)
7272 struct io_ring_ctx *ctx = file->private_data;
7275 poll_wait(file, &ctx->cq_wait, wait);
7277 * synchronizes with barrier from wq_has_sleeper call in
7281 if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head !=
7282 ctx->rings->sq_ring_entries)
7283 mask |= EPOLLOUT | EPOLLWRNORM;
7284 if (io_cqring_events(ctx, false))
7285 mask |= EPOLLIN | EPOLLRDNORM;
7290 static int io_uring_fasync(int fd, struct file *file, int on)
7292 struct io_ring_ctx *ctx = file->private_data;
7294 return fasync_helper(fd, file, on, &ctx->cq_fasync);
7297 static int io_remove_personalities(int id, void *p, void *data)
7299 struct io_ring_ctx *ctx = data;
7300 const struct cred *cred;
7302 cred = idr_remove(&ctx->personality_idr, id);
7308 static void io_ring_exit_work(struct work_struct *work)
7310 struct io_ring_ctx *ctx;
7312 ctx = container_of(work, struct io_ring_ctx, exit_work);
7314 io_cqring_overflow_flush(ctx, true);
7316 wait_for_completion(&ctx->completions[0]);
7317 io_ring_ctx_free(ctx);
7320 static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
7322 mutex_lock(&ctx->uring_lock);
7323 percpu_ref_kill(&ctx->refs);
7324 mutex_unlock(&ctx->uring_lock);
7327 * Wait for sq thread to idle, if we have one. It won't spin on new
7328 * work after we've killed the ctx ref above. This is important to do
7329 * before we cancel existing commands, as the thread could otherwise
7330 * be queueing new work post that. If that's work we need to cancel,
7331 * it could cause shutdown to hang.
7333 while (ctx->sqo_thread && !wq_has_sleeper(&ctx->sqo_wait))
7336 io_kill_timeouts(ctx);
7337 io_poll_remove_all(ctx);
7340 io_wq_cancel_all(ctx->io_wq);
7342 io_iopoll_reap_events(ctx);
7343 /* if we failed setting up the ctx, we might not have any rings */
7345 io_cqring_overflow_flush(ctx, true);
7346 idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx);
7347 INIT_WORK(&ctx->exit_work, io_ring_exit_work);
7348 queue_work(system_wq, &ctx->exit_work);
7351 static int io_uring_release(struct inode *inode, struct file *file)
7353 struct io_ring_ctx *ctx = file->private_data;
7355 file->private_data = NULL;
7356 io_ring_ctx_wait_and_kill(ctx);
7360 static void io_uring_cancel_files(struct io_ring_ctx *ctx,
7361 struct files_struct *files)
7363 struct io_kiocb *req;
7366 while (!list_empty_careful(&ctx->inflight_list)) {
7367 struct io_kiocb *cancel_req = NULL;
7369 spin_lock_irq(&ctx->inflight_lock);
7370 list_for_each_entry(req, &ctx->inflight_list, inflight_entry) {
7371 if (req->work.files != files)
7373 /* req is being completed, ignore */
7374 if (!refcount_inc_not_zero(&req->refs))
7380 prepare_to_wait(&ctx->inflight_wait, &wait,
7381 TASK_UNINTERRUPTIBLE);
7382 spin_unlock_irq(&ctx->inflight_lock);
7384 /* We need to keep going until we don't find a matching req */
7388 if (cancel_req->flags & REQ_F_OVERFLOW) {
7389 spin_lock_irq(&ctx->completion_lock);
7390 list_del(&cancel_req->list);
7391 cancel_req->flags &= ~REQ_F_OVERFLOW;
7392 if (list_empty(&ctx->cq_overflow_list)) {
7393 clear_bit(0, &ctx->sq_check_overflow);
7394 clear_bit(0, &ctx->cq_check_overflow);
7396 spin_unlock_irq(&ctx->completion_lock);
7398 WRITE_ONCE(ctx->rings->cq_overflow,
7399 atomic_inc_return(&ctx->cached_cq_overflow));
7402 * Put inflight ref and overflow ref. If that's
7403 * all we had, then we're done with this request.
7405 if (refcount_sub_and_test(2, &cancel_req->refs)) {
7406 io_put_req(cancel_req);
7411 io_wq_cancel_work(ctx->io_wq, &cancel_req->work);
7412 io_put_req(cancel_req);
7415 finish_wait(&ctx->inflight_wait, &wait);
7418 static int io_uring_flush(struct file *file, void *data)
7420 struct io_ring_ctx *ctx = file->private_data;
7422 io_uring_cancel_files(ctx, data);
7425 * If the task is going away, cancel work it may have pending
7427 if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
7428 io_wq_cancel_pid(ctx->io_wq, task_pid_vnr(current));
7433 static void *io_uring_validate_mmap_request(struct file *file,
7434 loff_t pgoff, size_t sz)
7436 struct io_ring_ctx *ctx = file->private_data;
7437 loff_t offset = pgoff << PAGE_SHIFT;
7442 case IORING_OFF_SQ_RING:
7443 case IORING_OFF_CQ_RING:
7446 case IORING_OFF_SQES:
7450 return ERR_PTR(-EINVAL);
7453 page = virt_to_head_page(ptr);
7454 if (sz > page_size(page))
7455 return ERR_PTR(-EINVAL);
7462 static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
7464 size_t sz = vma->vm_end - vma->vm_start;
7468 ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
7470 return PTR_ERR(ptr);
7472 pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
7473 return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
7476 #else /* !CONFIG_MMU */
7478 static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
7480 return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
7483 static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
7485 return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
7488 static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
7489 unsigned long addr, unsigned long len,
7490 unsigned long pgoff, unsigned long flags)
7494 ptr = io_uring_validate_mmap_request(file, pgoff, len);
7496 return PTR_ERR(ptr);
7498 return (unsigned long) ptr;
7501 #endif /* !CONFIG_MMU */
7503 SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
7504 u32, min_complete, u32, flags, const sigset_t __user *, sig,
7507 struct io_ring_ctx *ctx;
7512 if (current->task_works)
7515 if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP))
7523 if (f.file->f_op != &io_uring_fops)
7527 ctx = f.file->private_data;
7528 if (!percpu_ref_tryget(&ctx->refs))
7532 * For SQ polling, the thread will do all submissions and completions.
7533 * Just return the requested submit count, and wake the thread if
7537 if (ctx->flags & IORING_SETUP_SQPOLL) {
7538 if (!list_empty_careful(&ctx->cq_overflow_list))
7539 io_cqring_overflow_flush(ctx, false);
7540 if (flags & IORING_ENTER_SQ_WAKEUP)
7541 wake_up(&ctx->sqo_wait);
7542 submitted = to_submit;
7543 } else if (to_submit) {
7544 mutex_lock(&ctx->uring_lock);
7545 submitted = io_submit_sqes(ctx, to_submit, f.file, fd, false);
7546 mutex_unlock(&ctx->uring_lock);
7548 if (submitted != to_submit)
7551 if (flags & IORING_ENTER_GETEVENTS) {
7552 unsigned nr_events = 0;
7554 min_complete = min(min_complete, ctx->cq_entries);
7557 * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
7558 * space applications don't need to do io completion events
7559 * polling again, they can rely on io_sq_thread to do polling
7560 * work, which can reduce cpu usage and uring_lock contention.
7562 if (ctx->flags & IORING_SETUP_IOPOLL &&
7563 !(ctx->flags & IORING_SETUP_SQPOLL)) {
7564 ret = io_iopoll_check(ctx, &nr_events, min_complete);
7566 ret = io_cqring_wait(ctx, min_complete, sig, sigsz);
7571 percpu_ref_put(&ctx->refs);
7574 return submitted ? submitted : ret;
7577 #ifdef CONFIG_PROC_FS
7578 static int io_uring_show_cred(int id, void *p, void *data)
7580 const struct cred *cred = p;
7581 struct seq_file *m = data;
7582 struct user_namespace *uns = seq_user_ns(m);
7583 struct group_info *gi;
7588 seq_printf(m, "%5d\n", id);
7589 seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
7590 seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
7591 seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
7592 seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
7593 seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
7594 seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
7595 seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
7596 seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
7597 seq_puts(m, "\n\tGroups:\t");
7598 gi = cred->group_info;
7599 for (g = 0; g < gi->ngroups; g++) {
7600 seq_put_decimal_ull(m, g ? " " : "",
7601 from_kgid_munged(uns, gi->gid[g]));
7603 seq_puts(m, "\n\tCapEff:\t");
7604 cap = cred->cap_effective;
7605 CAP_FOR_EACH_U32(__capi)
7606 seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
7611 static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
7615 mutex_lock(&ctx->uring_lock);
7616 seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
7617 for (i = 0; i < ctx->nr_user_files; i++) {
7618 struct fixed_file_table *table;
7621 table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
7622 f = table->files[i & IORING_FILE_TABLE_MASK];
7624 seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
7626 seq_printf(m, "%5u: <none>\n", i);
7628 seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
7629 for (i = 0; i < ctx->nr_user_bufs; i++) {
7630 struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
7632 seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
7633 (unsigned int) buf->len);
7635 if (!idr_is_empty(&ctx->personality_idr)) {
7636 seq_printf(m, "Personalities:\n");
7637 idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
7639 seq_printf(m, "PollList:\n");
7640 spin_lock_irq(&ctx->completion_lock);
7641 for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
7642 struct hlist_head *list = &ctx->cancel_hash[i];
7643 struct io_kiocb *req;
7645 hlist_for_each_entry(req, list, hash_node)
7646 seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
7647 req->task->task_works != NULL);
7649 spin_unlock_irq(&ctx->completion_lock);
7650 mutex_unlock(&ctx->uring_lock);
7653 static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
7655 struct io_ring_ctx *ctx = f->private_data;
7657 if (percpu_ref_tryget(&ctx->refs)) {
7658 __io_uring_show_fdinfo(ctx, m);
7659 percpu_ref_put(&ctx->refs);
7664 static const struct file_operations io_uring_fops = {
7665 .release = io_uring_release,
7666 .flush = io_uring_flush,
7667 .mmap = io_uring_mmap,
7669 .get_unmapped_area = io_uring_nommu_get_unmapped_area,
7670 .mmap_capabilities = io_uring_nommu_mmap_capabilities,
7672 .poll = io_uring_poll,
7673 .fasync = io_uring_fasync,
7674 #ifdef CONFIG_PROC_FS
7675 .show_fdinfo = io_uring_show_fdinfo,
7679 static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
7680 struct io_uring_params *p)
7682 struct io_rings *rings;
7683 size_t size, sq_array_offset;
7685 size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
7686 if (size == SIZE_MAX)
7689 rings = io_mem_alloc(size);
7694 ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
7695 rings->sq_ring_mask = p->sq_entries - 1;
7696 rings->cq_ring_mask = p->cq_entries - 1;
7697 rings->sq_ring_entries = p->sq_entries;
7698 rings->cq_ring_entries = p->cq_entries;
7699 ctx->sq_mask = rings->sq_ring_mask;
7700 ctx->cq_mask = rings->cq_ring_mask;
7701 ctx->sq_entries = rings->sq_ring_entries;
7702 ctx->cq_entries = rings->cq_ring_entries;
7704 size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
7705 if (size == SIZE_MAX) {
7706 io_mem_free(ctx->rings);
7711 ctx->sq_sqes = io_mem_alloc(size);
7712 if (!ctx->sq_sqes) {
7713 io_mem_free(ctx->rings);
7722 * Allocate an anonymous fd, this is what constitutes the application
7723 * visible backing of an io_uring instance. The application mmaps this
7724 * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
7725 * we have to tie this fd to a socket for file garbage collection purposes.
7727 static int io_uring_get_fd(struct io_ring_ctx *ctx)
7732 #if defined(CONFIG_UNIX)
7733 ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
7739 ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
7743 file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
7744 O_RDWR | O_CLOEXEC);
7747 ret = PTR_ERR(file);
7751 #if defined(CONFIG_UNIX)
7752 ctx->ring_sock->file = file;
7754 fd_install(ret, file);
7757 #if defined(CONFIG_UNIX)
7758 sock_release(ctx->ring_sock);
7759 ctx->ring_sock = NULL;
7764 static int io_uring_create(unsigned entries, struct io_uring_params *p)
7766 struct user_struct *user = NULL;
7767 struct io_ring_ctx *ctx;
7773 if (entries > IORING_MAX_ENTRIES) {
7774 if (!(p->flags & IORING_SETUP_CLAMP))
7776 entries = IORING_MAX_ENTRIES;
7780 * Use twice as many entries for the CQ ring. It's possible for the
7781 * application to drive a higher depth than the size of the SQ ring,
7782 * since the sqes are only used at submission time. This allows for
7783 * some flexibility in overcommitting a bit. If the application has
7784 * set IORING_SETUP_CQSIZE, it will have passed in the desired number
7785 * of CQ ring entries manually.
7787 p->sq_entries = roundup_pow_of_two(entries);
7788 if (p->flags & IORING_SETUP_CQSIZE) {
7790 * If IORING_SETUP_CQSIZE is set, we do the same roundup
7791 * to a power-of-two, if it isn't already. We do NOT impose
7792 * any cq vs sq ring sizing.
7794 if (p->cq_entries < p->sq_entries)
7796 if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
7797 if (!(p->flags & IORING_SETUP_CLAMP))
7799 p->cq_entries = IORING_MAX_CQ_ENTRIES;
7801 p->cq_entries = roundup_pow_of_two(p->cq_entries);
7803 p->cq_entries = 2 * p->sq_entries;
7806 user = get_uid(current_user());
7807 account_mem = !capable(CAP_IPC_LOCK);
7810 ret = io_account_mem(user,
7811 ring_pages(p->sq_entries, p->cq_entries));
7818 ctx = io_ring_ctx_alloc(p);
7821 io_unaccount_mem(user, ring_pages(p->sq_entries,
7826 ctx->compat = in_compat_syscall();
7827 ctx->account_mem = account_mem;
7829 ctx->creds = get_current_cred();
7831 ret = io_allocate_scq_urings(ctx, p);
7835 ret = io_sq_offload_start(ctx, p);
7839 memset(&p->sq_off, 0, sizeof(p->sq_off));
7840 p->sq_off.head = offsetof(struct io_rings, sq.head);
7841 p->sq_off.tail = offsetof(struct io_rings, sq.tail);
7842 p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
7843 p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
7844 p->sq_off.flags = offsetof(struct io_rings, sq_flags);
7845 p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
7846 p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
7848 memset(&p->cq_off, 0, sizeof(p->cq_off));
7849 p->cq_off.head = offsetof(struct io_rings, cq.head);
7850 p->cq_off.tail = offsetof(struct io_rings, cq.tail);
7851 p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
7852 p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
7853 p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
7854 p->cq_off.cqes = offsetof(struct io_rings, cqes);
7857 * Install ring fd as the very last thing, so we don't risk someone
7858 * having closed it before we finish setup
7860 ret = io_uring_get_fd(ctx);
7864 p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
7865 IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
7866 IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL;
7867 trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
7870 io_ring_ctx_wait_and_kill(ctx);
7875 * Sets up an aio uring context, and returns the fd. Applications asks for a
7876 * ring size, we return the actual sq/cq ring sizes (among other things) in the
7877 * params structure passed in.
7879 static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
7881 struct io_uring_params p;
7885 if (copy_from_user(&p, params, sizeof(p)))
7887 for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
7892 if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
7893 IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
7894 IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ))
7897 ret = io_uring_create(entries, &p);
7901 if (copy_to_user(params, &p, sizeof(p)))
7907 SYSCALL_DEFINE2(io_uring_setup, u32, entries,
7908 struct io_uring_params __user *, params)
7910 return io_uring_setup(entries, params);
7913 static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
7915 struct io_uring_probe *p;
7919 size = struct_size(p, ops, nr_args);
7920 if (size == SIZE_MAX)
7922 p = kzalloc(size, GFP_KERNEL);
7927 if (copy_from_user(p, arg, size))
7930 if (memchr_inv(p, 0, size))
7933 p->last_op = IORING_OP_LAST - 1;
7934 if (nr_args > IORING_OP_LAST)
7935 nr_args = IORING_OP_LAST;
7937 for (i = 0; i < nr_args; i++) {
7939 if (!io_op_defs[i].not_supported)
7940 p->ops[i].flags = IO_URING_OP_SUPPORTED;
7945 if (copy_to_user(arg, p, size))
7952 static int io_register_personality(struct io_ring_ctx *ctx)
7954 const struct cred *creds = get_current_cred();
7957 id = idr_alloc_cyclic(&ctx->personality_idr, (void *) creds, 1,
7958 USHRT_MAX, GFP_KERNEL);
7964 static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
7966 const struct cred *old_creds;
7968 old_creds = idr_remove(&ctx->personality_idr, id);
7970 put_cred(old_creds);
7977 static bool io_register_op_must_quiesce(int op)
7980 case IORING_UNREGISTER_FILES:
7981 case IORING_REGISTER_FILES_UPDATE:
7982 case IORING_REGISTER_PROBE:
7983 case IORING_REGISTER_PERSONALITY:
7984 case IORING_UNREGISTER_PERSONALITY:
7991 static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
7992 void __user *arg, unsigned nr_args)
7993 __releases(ctx->uring_lock)
7994 __acquires(ctx->uring_lock)
7999 * We're inside the ring mutex, if the ref is already dying, then
8000 * someone else killed the ctx or is already going through
8001 * io_uring_register().
8003 if (percpu_ref_is_dying(&ctx->refs))
8006 if (io_register_op_must_quiesce(opcode)) {
8007 percpu_ref_kill(&ctx->refs);
8010 * Drop uring mutex before waiting for references to exit. If
8011 * another thread is currently inside io_uring_enter() it might
8012 * need to grab the uring_lock to make progress. If we hold it
8013 * here across the drain wait, then we can deadlock. It's safe
8014 * to drop the mutex here, since no new references will come in
8015 * after we've killed the percpu ref.
8017 mutex_unlock(&ctx->uring_lock);
8018 ret = wait_for_completion_interruptible(&ctx->completions[0]);
8019 mutex_lock(&ctx->uring_lock);
8021 percpu_ref_resurrect(&ctx->refs);
8028 case IORING_REGISTER_BUFFERS:
8029 ret = io_sqe_buffer_register(ctx, arg, nr_args);
8031 case IORING_UNREGISTER_BUFFERS:
8035 ret = io_sqe_buffer_unregister(ctx);
8037 case IORING_REGISTER_FILES:
8038 ret = io_sqe_files_register(ctx, arg, nr_args);
8040 case IORING_UNREGISTER_FILES:
8044 ret = io_sqe_files_unregister(ctx);
8046 case IORING_REGISTER_FILES_UPDATE:
8047 ret = io_sqe_files_update(ctx, arg, nr_args);
8049 case IORING_REGISTER_EVENTFD:
8050 case IORING_REGISTER_EVENTFD_ASYNC:
8054 ret = io_eventfd_register(ctx, arg);
8057 if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
8058 ctx->eventfd_async = 1;
8060 ctx->eventfd_async = 0;
8062 case IORING_UNREGISTER_EVENTFD:
8066 ret = io_eventfd_unregister(ctx);
8068 case IORING_REGISTER_PROBE:
8070 if (!arg || nr_args > 256)
8072 ret = io_probe(ctx, arg, nr_args);
8074 case IORING_REGISTER_PERSONALITY:
8078 ret = io_register_personality(ctx);
8080 case IORING_UNREGISTER_PERSONALITY:
8084 ret = io_unregister_personality(ctx, nr_args);
8091 if (io_register_op_must_quiesce(opcode)) {
8092 /* bring the ctx back to life */
8093 percpu_ref_reinit(&ctx->refs);
8095 reinit_completion(&ctx->completions[0]);
8100 SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
8101 void __user *, arg, unsigned int, nr_args)
8103 struct io_ring_ctx *ctx;
8112 if (f.file->f_op != &io_uring_fops)
8115 ctx = f.file->private_data;
8117 mutex_lock(&ctx->uring_lock);
8118 ret = __io_uring_register(ctx, opcode, arg, nr_args);
8119 mutex_unlock(&ctx->uring_lock);
8120 trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
8121 ctx->cq_ev_fd != NULL, ret);
8127 static int __init io_uring_init(void)
8129 #define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
8130 BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
8131 BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
8134 #define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
8135 __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
8136 BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
8137 BUILD_BUG_SQE_ELEM(0, __u8, opcode);
8138 BUILD_BUG_SQE_ELEM(1, __u8, flags);
8139 BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
8140 BUILD_BUG_SQE_ELEM(4, __s32, fd);
8141 BUILD_BUG_SQE_ELEM(8, __u64, off);
8142 BUILD_BUG_SQE_ELEM(8, __u64, addr2);
8143 BUILD_BUG_SQE_ELEM(16, __u64, addr);
8144 BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
8145 BUILD_BUG_SQE_ELEM(24, __u32, len);
8146 BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
8147 BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
8148 BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
8149 BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
8150 BUILD_BUG_SQE_ELEM(28, __u16, poll_events);
8151 BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
8152 BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
8153 BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
8154 BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
8155 BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
8156 BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
8157 BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
8158 BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
8159 BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
8160 BUILD_BUG_SQE_ELEM(32, __u64, user_data);
8161 BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
8162 BUILD_BUG_SQE_ELEM(42, __u16, personality);
8163 BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
8165 BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
8166 BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
8167 req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
8170 __initcall(io_uring_init);