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/percpu.h>
59 #include <linux/slab.h>
60 #include <linux/kthread.h>
61 #include <linux/blkdev.h>
62 #include <linux/bvec.h>
63 #include <linux/net.h>
65 #include <net/af_unix.h>
67 #include <linux/anon_inodes.h>
68 #include <linux/sched/mm.h>
69 #include <linux/uaccess.h>
70 #include <linux/nospec.h>
71 #include <linux/sizes.h>
72 #include <linux/hugetlb.h>
73 #include <linux/highmem.h>
74 #include <linux/namei.h>
75 #include <linux/fsnotify.h>
76 #include <linux/fadvise.h>
77 #include <linux/eventpoll.h>
78 #include <linux/fs_struct.h>
79 #include <linux/splice.h>
80 #include <linux/task_work.h>
81 #include <linux/pagemap.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.
157 * Written by the application, shouldn't be modified by the
162 * Number of completion events lost because the queue was full;
163 * this should be avoided by the application by making sure
164 * there are not more requests pending than there is space in
165 * the completion queue.
167 * Written by the kernel, shouldn't be modified by the
168 * application (i.e. get number of "new events" by comparing to
171 * As completion events come in out of order this counter is not
172 * ordered with any other data.
176 * Ring buffer of completion events.
178 * The kernel writes completion events fresh every time they are
179 * produced, so the application is allowed to modify pending
182 struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
185 struct io_mapped_ubuf {
188 struct bio_vec *bvec;
189 unsigned int nr_bvecs;
192 struct fixed_file_table {
196 struct fixed_file_ref_node {
197 struct percpu_ref refs;
198 struct list_head node;
199 struct list_head file_list;
200 struct fixed_file_data *file_data;
201 struct llist_node llist;
204 struct fixed_file_data {
205 struct fixed_file_table *table;
206 struct io_ring_ctx *ctx;
208 struct percpu_ref *cur_refs;
209 struct percpu_ref refs;
210 struct completion done;
211 struct list_head ref_list;
216 struct list_head list;
224 struct percpu_ref refs;
225 } ____cacheline_aligned_in_smp;
229 unsigned int compat: 1;
230 unsigned int limit_mem: 1;
231 unsigned int cq_overflow_flushed: 1;
232 unsigned int drain_next: 1;
233 unsigned int eventfd_async: 1;
236 * Ring buffer of indices into array of io_uring_sqe, which is
237 * mmapped by the application using the IORING_OFF_SQES offset.
239 * This indirection could e.g. be used to assign fixed
240 * io_uring_sqe entries to operations and only submit them to
241 * the queue when needed.
243 * The kernel modifies neither the indices array nor the entries
247 unsigned cached_sq_head;
250 unsigned sq_thread_idle;
251 unsigned cached_sq_dropped;
252 atomic_t cached_cq_overflow;
253 unsigned long sq_check_overflow;
255 struct list_head defer_list;
256 struct list_head timeout_list;
257 struct list_head cq_overflow_list;
259 wait_queue_head_t inflight_wait;
260 struct io_uring_sqe *sq_sqes;
261 } ____cacheline_aligned_in_smp;
263 struct io_rings *rings;
267 struct task_struct *sqo_thread; /* if using sq thread polling */
268 struct mm_struct *sqo_mm;
269 wait_queue_head_t sqo_wait;
272 * If used, fixed file set. Writers must ensure that ->refs is dead,
273 * readers must ensure that ->refs is alive as long as the file* is
274 * used. Only updated through io_uring_register(2).
276 struct fixed_file_data *file_data;
277 unsigned nr_user_files;
279 struct file *ring_file;
281 /* if used, fixed mapped user buffers */
282 unsigned nr_user_bufs;
283 struct io_mapped_ubuf *user_bufs;
285 struct user_struct *user;
287 const struct cred *creds;
289 struct completion ref_comp;
290 struct completion sq_thread_comp;
292 /* if all else fails... */
293 struct io_kiocb *fallback_req;
295 #if defined(CONFIG_UNIX)
296 struct socket *ring_sock;
299 struct idr io_buffer_idr;
301 struct idr personality_idr;
304 unsigned cached_cq_tail;
307 atomic_t cq_timeouts;
308 unsigned long cq_check_overflow;
309 struct wait_queue_head cq_wait;
310 struct fasync_struct *cq_fasync;
311 struct eventfd_ctx *cq_ev_fd;
312 } ____cacheline_aligned_in_smp;
315 struct mutex uring_lock;
316 wait_queue_head_t wait;
317 } ____cacheline_aligned_in_smp;
320 spinlock_t completion_lock;
323 * ->iopoll_list is protected by the ctx->uring_lock for
324 * io_uring instances that don't use IORING_SETUP_SQPOLL.
325 * For SQPOLL, only the single threaded io_sq_thread() will
326 * manipulate the list, hence no extra locking is needed there.
328 struct list_head iopoll_list;
329 struct hlist_head *cancel_hash;
330 unsigned cancel_hash_bits;
331 bool poll_multi_file;
333 spinlock_t inflight_lock;
334 struct list_head inflight_list;
335 } ____cacheline_aligned_in_smp;
337 struct delayed_work file_put_work;
338 struct llist_head file_put_llist;
340 struct work_struct exit_work;
344 * First field must be the file pointer in all the
345 * iocb unions! See also 'struct kiocb' in <linux/fs.h>
347 struct io_poll_iocb {
350 struct wait_queue_head *head;
356 struct wait_queue_entry wait;
361 struct file *put_file;
365 struct io_timeout_data {
366 struct io_kiocb *req;
367 struct hrtimer timer;
368 struct timespec64 ts;
369 enum hrtimer_mode mode;
374 struct sockaddr __user *addr;
375 int __user *addr_len;
377 unsigned long nofile;
399 struct list_head list;
403 /* NOTE: kiocb has the file as the first member, so don't do it here */
411 struct sockaddr __user *addr;
418 struct user_msghdr __user *umsg;
424 struct io_buffer *kbuf;
430 struct filename *filename;
432 unsigned long nofile;
435 struct io_files_update {
461 struct epoll_event event;
465 struct file *file_out;
466 struct file *file_in;
473 struct io_provide_buf {
487 const char __user *filename;
488 struct statx __user *buffer;
491 struct io_completion {
493 struct list_head list;
497 struct io_async_connect {
498 struct sockaddr_storage address;
501 struct io_async_msghdr {
502 struct iovec fast_iov[UIO_FASTIOV];
504 struct sockaddr __user *uaddr;
506 struct sockaddr_storage addr;
510 struct iovec fast_iov[UIO_FASTIOV];
511 const struct iovec *free_iovec;
512 struct iov_iter iter;
514 struct wait_page_queue wpq;
517 struct io_async_ctx {
519 struct io_async_rw rw;
520 struct io_async_msghdr msg;
521 struct io_async_connect connect;
522 struct io_timeout_data timeout;
527 REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
528 REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
529 REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
530 REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
531 REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
532 REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
539 REQ_F_LINK_TIMEOUT_BIT,
541 REQ_F_COMP_LOCKED_BIT,
542 REQ_F_NEED_CLEANUP_BIT,
545 REQ_F_BUFFER_SELECTED_BIT,
546 REQ_F_NO_FILE_TABLE_BIT,
547 REQ_F_WORK_INITIALIZED_BIT,
548 REQ_F_TASK_PINNED_BIT,
550 /* not a real bit, just to check we're not overflowing the space */
556 REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
557 /* drain existing IO first */
558 REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
560 REQ_F_LINK = BIT(REQ_F_LINK_BIT),
561 /* doesn't sever on completion < 0 */
562 REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
564 REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
565 /* IOSQE_BUFFER_SELECT */
566 REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
569 REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT),
570 /* fail rest of links */
571 REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT),
572 /* on inflight list */
573 REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
574 /* read/write uses file position */
575 REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
576 /* must not punt to workers */
577 REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
578 /* has linked timeout */
579 REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
581 REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
582 /* completion under lock */
583 REQ_F_COMP_LOCKED = BIT(REQ_F_COMP_LOCKED_BIT),
585 REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
586 /* in overflow list */
587 REQ_F_OVERFLOW = BIT(REQ_F_OVERFLOW_BIT),
588 /* already went through poll handler */
589 REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
590 /* buffer already selected */
591 REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
592 /* doesn't need file table for this request */
593 REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
594 /* io_wq_work is initialized */
595 REQ_F_WORK_INITIALIZED = BIT(REQ_F_WORK_INITIALIZED_BIT),
596 /* req->task is refcounted */
597 REQ_F_TASK_PINNED = BIT(REQ_F_TASK_PINNED_BIT),
601 struct io_poll_iocb poll;
602 struct io_poll_iocb *double_poll;
606 * NOTE! Each of the iocb union members has the file pointer
607 * as the first entry in their struct definition. So you can
608 * access the file pointer through any of the sub-structs,
609 * or directly as just 'ki_filp' in this struct.
615 struct io_poll_iocb poll;
616 struct io_accept accept;
618 struct io_cancel cancel;
619 struct io_timeout timeout;
620 struct io_connect connect;
621 struct io_sr_msg sr_msg;
623 struct io_close close;
624 struct io_files_update files_update;
625 struct io_fadvise fadvise;
626 struct io_madvise madvise;
627 struct io_epoll epoll;
628 struct io_splice splice;
629 struct io_provide_buf pbuf;
630 struct io_statx statx;
631 /* use only after cleaning per-op data, see io_clean_op() */
632 struct io_completion compl;
635 struct io_async_ctx *io;
637 /* polled IO has completed */
643 struct io_ring_ctx *ctx;
646 struct task_struct *task;
649 struct list_head link_list;
652 * 1. used with ctx->iopoll_list with reads/writes
653 * 2. to track reqs with ->files (see io_op_def::file_table)
655 struct list_head inflight_entry;
657 struct percpu_ref *fixed_file_refs;
658 struct callback_head task_work;
659 /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
660 struct hlist_node hash_node;
661 struct async_poll *apoll;
662 struct io_wq_work work;
665 struct io_defer_entry {
666 struct list_head list;
667 struct io_kiocb *req;
671 #define IO_IOPOLL_BATCH 8
673 struct io_comp_state {
675 struct list_head list;
676 struct io_ring_ctx *ctx;
679 struct io_submit_state {
680 struct blk_plug plug;
683 * io_kiocb alloc cache
685 void *reqs[IO_IOPOLL_BATCH];
686 unsigned int free_reqs;
689 * Batch completion logic
691 struct io_comp_state comp;
694 * File reference cache
698 unsigned int has_refs;
699 unsigned int ios_left;
703 /* needs req->io allocated for deferral/async */
704 unsigned async_ctx : 1;
705 /* needs current->mm setup, does mm access */
706 unsigned needs_mm : 1;
707 /* needs req->file assigned */
708 unsigned needs_file : 1;
709 /* don't fail if file grab fails */
710 unsigned needs_file_no_error : 1;
711 /* hash wq insertion if file is a regular file */
712 unsigned hash_reg_file : 1;
713 /* unbound wq insertion if file is a non-regular file */
714 unsigned unbound_nonreg_file : 1;
715 /* opcode is not supported by this kernel */
716 unsigned not_supported : 1;
717 /* needs file table */
718 unsigned file_table : 1;
720 unsigned needs_fs : 1;
721 /* set if opcode supports polled "wait" */
723 unsigned pollout : 1;
724 /* op supports buffer selection */
725 unsigned buffer_select : 1;
726 unsigned needs_fsize : 1;
729 static const struct io_op_def io_op_defs[] = {
730 [IORING_OP_NOP] = {},
731 [IORING_OP_READV] = {
735 .unbound_nonreg_file = 1,
739 [IORING_OP_WRITEV] = {
744 .unbound_nonreg_file = 1,
748 [IORING_OP_FSYNC] = {
751 [IORING_OP_READ_FIXED] = {
753 .unbound_nonreg_file = 1,
756 [IORING_OP_WRITE_FIXED] = {
759 .unbound_nonreg_file = 1,
763 [IORING_OP_POLL_ADD] = {
765 .unbound_nonreg_file = 1,
767 [IORING_OP_POLL_REMOVE] = {},
768 [IORING_OP_SYNC_FILE_RANGE] = {
771 [IORING_OP_SENDMSG] = {
775 .unbound_nonreg_file = 1,
779 [IORING_OP_RECVMSG] = {
783 .unbound_nonreg_file = 1,
788 [IORING_OP_TIMEOUT] = {
792 [IORING_OP_TIMEOUT_REMOVE] = {},
793 [IORING_OP_ACCEPT] = {
796 .unbound_nonreg_file = 1,
800 [IORING_OP_ASYNC_CANCEL] = {},
801 [IORING_OP_LINK_TIMEOUT] = {
805 [IORING_OP_CONNECT] = {
809 .unbound_nonreg_file = 1,
812 [IORING_OP_FALLOCATE] = {
816 [IORING_OP_OPENAT] = {
820 [IORING_OP_CLOSE] = {
822 .needs_file_no_error = 1,
825 [IORING_OP_FILES_UPDATE] = {
829 [IORING_OP_STATX] = {
837 .unbound_nonreg_file = 1,
841 [IORING_OP_WRITE] = {
844 .unbound_nonreg_file = 1,
848 [IORING_OP_FADVISE] = {
851 [IORING_OP_MADVISE] = {
857 .unbound_nonreg_file = 1,
863 .unbound_nonreg_file = 1,
867 [IORING_OP_OPENAT2] = {
871 [IORING_OP_EPOLL_CTL] = {
872 .unbound_nonreg_file = 1,
875 [IORING_OP_SPLICE] = {
878 .unbound_nonreg_file = 1,
880 [IORING_OP_PROVIDE_BUFFERS] = {},
881 [IORING_OP_REMOVE_BUFFERS] = {},
885 .unbound_nonreg_file = 1,
889 enum io_mem_account {
894 static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
895 struct io_comp_state *cs);
896 static void io_cqring_fill_event(struct io_kiocb *req, long res);
897 static void io_put_req(struct io_kiocb *req);
898 static void io_double_put_req(struct io_kiocb *req);
899 static void __io_double_put_req(struct io_kiocb *req);
900 static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
901 static void __io_queue_linked_timeout(struct io_kiocb *req);
902 static void io_queue_linked_timeout(struct io_kiocb *req);
903 static int __io_sqe_files_update(struct io_ring_ctx *ctx,
904 struct io_uring_files_update *ip,
906 static int io_prep_work_files(struct io_kiocb *req);
907 static void __io_clean_op(struct io_kiocb *req);
908 static int io_file_get(struct io_submit_state *state, struct io_kiocb *req,
909 int fd, struct file **out_file, bool fixed);
910 static void __io_queue_sqe(struct io_kiocb *req,
911 const struct io_uring_sqe *sqe,
912 struct io_comp_state *cs);
913 static void io_file_put_work(struct work_struct *work);
915 static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
916 struct iovec **iovec, struct iov_iter *iter,
918 static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
919 const struct iovec *fast_iov,
920 struct iov_iter *iter, bool force);
922 static struct kmem_cache *req_cachep;
924 static const struct file_operations io_uring_fops;
926 struct sock *io_uring_get_socket(struct file *file)
928 #if defined(CONFIG_UNIX)
929 if (file->f_op == &io_uring_fops) {
930 struct io_ring_ctx *ctx = file->private_data;
932 return ctx->ring_sock->sk;
937 EXPORT_SYMBOL(io_uring_get_socket);
939 static void io_get_req_task(struct io_kiocb *req)
941 if (req->flags & REQ_F_TASK_PINNED)
943 get_task_struct(req->task);
944 req->flags |= REQ_F_TASK_PINNED;
947 static inline void io_clean_op(struct io_kiocb *req)
949 if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED))
953 /* not idempotent -- it doesn't clear REQ_F_TASK_PINNED */
954 static void __io_put_req_task(struct io_kiocb *req)
956 if (req->flags & REQ_F_TASK_PINNED)
957 put_task_struct(req->task);
960 static void io_sq_thread_drop_mm(void)
962 struct mm_struct *mm = current->mm;
965 kthread_unuse_mm(mm);
970 static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
973 if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL) ||
974 !mmget_not_zero(ctx->sqo_mm)))
976 kthread_use_mm(ctx->sqo_mm);
982 static int io_sq_thread_acquire_mm(struct io_ring_ctx *ctx,
983 struct io_kiocb *req)
985 if (!io_op_defs[req->opcode].needs_mm)
987 return __io_sq_thread_acquire_mm(ctx);
990 static inline void req_set_fail_links(struct io_kiocb *req)
992 if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK)
993 req->flags |= REQ_F_FAIL_LINK;
997 * Note: must call io_req_init_async() for the first time you
998 * touch any members of io_wq_work.
1000 static inline void io_req_init_async(struct io_kiocb *req)
1002 if (req->flags & REQ_F_WORK_INITIALIZED)
1005 memset(&req->work, 0, sizeof(req->work));
1006 req->flags |= REQ_F_WORK_INITIALIZED;
1009 static inline bool io_async_submit(struct io_ring_ctx *ctx)
1011 return ctx->flags & IORING_SETUP_SQPOLL;
1014 static void io_ring_ctx_ref_free(struct percpu_ref *ref)
1016 struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
1018 complete(&ctx->ref_comp);
1021 static inline bool io_is_timeout_noseq(struct io_kiocb *req)
1023 return !req->timeout.off;
1026 static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
1028 struct io_ring_ctx *ctx;
1031 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
1035 ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL);
1036 if (!ctx->fallback_req)
1040 * Use 5 bits less than the max cq entries, that should give us around
1041 * 32 entries per hash list if totally full and uniformly spread.
1043 hash_bits = ilog2(p->cq_entries);
1047 ctx->cancel_hash_bits = hash_bits;
1048 ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
1050 if (!ctx->cancel_hash)
1052 __hash_init(ctx->cancel_hash, 1U << hash_bits);
1054 if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
1055 PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
1058 ctx->flags = p->flags;
1059 init_waitqueue_head(&ctx->sqo_wait);
1060 init_waitqueue_head(&ctx->cq_wait);
1061 INIT_LIST_HEAD(&ctx->cq_overflow_list);
1062 init_completion(&ctx->ref_comp);
1063 init_completion(&ctx->sq_thread_comp);
1064 idr_init(&ctx->io_buffer_idr);
1065 idr_init(&ctx->personality_idr);
1066 mutex_init(&ctx->uring_lock);
1067 init_waitqueue_head(&ctx->wait);
1068 spin_lock_init(&ctx->completion_lock);
1069 INIT_LIST_HEAD(&ctx->iopoll_list);
1070 INIT_LIST_HEAD(&ctx->defer_list);
1071 INIT_LIST_HEAD(&ctx->timeout_list);
1072 init_waitqueue_head(&ctx->inflight_wait);
1073 spin_lock_init(&ctx->inflight_lock);
1074 INIT_LIST_HEAD(&ctx->inflight_list);
1075 INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work);
1076 init_llist_head(&ctx->file_put_llist);
1079 if (ctx->fallback_req)
1080 kmem_cache_free(req_cachep, ctx->fallback_req);
1081 kfree(ctx->cancel_hash);
1086 static bool req_need_defer(struct io_kiocb *req, u32 seq)
1088 if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
1089 struct io_ring_ctx *ctx = req->ctx;
1091 return seq != ctx->cached_cq_tail
1092 + atomic_read(&ctx->cached_cq_overflow);
1098 static void __io_commit_cqring(struct io_ring_ctx *ctx)
1100 struct io_rings *rings = ctx->rings;
1102 /* order cqe stores with ring update */
1103 smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
1105 if (wq_has_sleeper(&ctx->cq_wait)) {
1106 wake_up_interruptible(&ctx->cq_wait);
1107 kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
1112 * Returns true if we need to defer file table putting. This can only happen
1113 * from the error path with REQ_F_COMP_LOCKED set.
1115 static bool io_req_clean_work(struct io_kiocb *req)
1117 if (!(req->flags & REQ_F_WORK_INITIALIZED))
1120 req->flags &= ~REQ_F_WORK_INITIALIZED;
1123 mmdrop(req->work.mm);
1124 req->work.mm = NULL;
1126 if (req->work.creds) {
1127 put_cred(req->work.creds);
1128 req->work.creds = NULL;
1131 struct fs_struct *fs = req->work.fs;
1133 if (req->flags & REQ_F_COMP_LOCKED)
1136 spin_lock(&req->work.fs->lock);
1139 spin_unlock(&req->work.fs->lock);
1142 req->work.fs = NULL;
1148 static void io_prep_async_work(struct io_kiocb *req)
1150 const struct io_op_def *def = &io_op_defs[req->opcode];
1152 io_req_init_async(req);
1154 if (req->flags & REQ_F_ISREG) {
1155 if (def->hash_reg_file)
1156 io_wq_hash_work(&req->work, file_inode(req->file));
1158 if (def->unbound_nonreg_file)
1159 req->work.flags |= IO_WQ_WORK_UNBOUND;
1161 if (!req->work.mm && def->needs_mm) {
1162 mmgrab(current->mm);
1163 req->work.mm = current->mm;
1165 if (!req->work.creds)
1166 req->work.creds = get_current_cred();
1167 if (!req->work.fs && def->needs_fs) {
1168 spin_lock(¤t->fs->lock);
1169 if (!current->fs->in_exec) {
1170 req->work.fs = current->fs;
1171 req->work.fs->users++;
1173 req->work.flags |= IO_WQ_WORK_CANCEL;
1175 spin_unlock(¤t->fs->lock);
1177 if (def->needs_fsize)
1178 req->work.fsize = rlimit(RLIMIT_FSIZE);
1180 req->work.fsize = RLIM_INFINITY;
1183 static void io_prep_async_link(struct io_kiocb *req)
1185 struct io_kiocb *cur;
1187 io_prep_async_work(req);
1188 if (req->flags & REQ_F_LINK_HEAD)
1189 list_for_each_entry(cur, &req->link_list, link_list)
1190 io_prep_async_work(cur);
1193 static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req)
1195 struct io_ring_ctx *ctx = req->ctx;
1196 struct io_kiocb *link = io_prep_linked_timeout(req);
1198 trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
1199 &req->work, req->flags);
1200 io_wq_enqueue(ctx->io_wq, &req->work);
1204 static void io_queue_async_work(struct io_kiocb *req)
1206 struct io_kiocb *link;
1208 /* init ->work of the whole link before punting */
1209 io_prep_async_link(req);
1210 link = __io_queue_async_work(req);
1213 io_queue_linked_timeout(link);
1216 static void io_kill_timeout(struct io_kiocb *req)
1220 ret = hrtimer_try_to_cancel(&req->io->timeout.timer);
1222 atomic_set(&req->ctx->cq_timeouts,
1223 atomic_read(&req->ctx->cq_timeouts) + 1);
1224 list_del_init(&req->timeout.list);
1225 req->flags |= REQ_F_COMP_LOCKED;
1226 io_cqring_fill_event(req, 0);
1231 static void io_kill_timeouts(struct io_ring_ctx *ctx)
1233 struct io_kiocb *req, *tmp;
1235 spin_lock_irq(&ctx->completion_lock);
1236 list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list)
1237 io_kill_timeout(req);
1238 spin_unlock_irq(&ctx->completion_lock);
1241 static void __io_queue_deferred(struct io_ring_ctx *ctx)
1244 struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
1245 struct io_defer_entry, list);
1246 struct io_kiocb *link;
1248 if (req_need_defer(de->req, de->seq))
1250 list_del_init(&de->list);
1251 /* punt-init is done before queueing for defer */
1252 link = __io_queue_async_work(de->req);
1254 __io_queue_linked_timeout(link);
1255 /* drop submission reference */
1256 link->flags |= REQ_F_COMP_LOCKED;
1260 } while (!list_empty(&ctx->defer_list));
1263 static void io_flush_timeouts(struct io_ring_ctx *ctx)
1265 while (!list_empty(&ctx->timeout_list)) {
1266 struct io_kiocb *req = list_first_entry(&ctx->timeout_list,
1267 struct io_kiocb, timeout.list);
1269 if (io_is_timeout_noseq(req))
1271 if (req->timeout.target_seq != ctx->cached_cq_tail
1272 - atomic_read(&ctx->cq_timeouts))
1275 list_del_init(&req->timeout.list);
1276 io_kill_timeout(req);
1280 static void io_commit_cqring(struct io_ring_ctx *ctx)
1282 io_flush_timeouts(ctx);
1283 __io_commit_cqring(ctx);
1285 if (unlikely(!list_empty(&ctx->defer_list)))
1286 __io_queue_deferred(ctx);
1289 static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
1291 struct io_rings *rings = ctx->rings;
1294 tail = ctx->cached_cq_tail;
1296 * writes to the cq entry need to come after reading head; the
1297 * control dependency is enough as we're using WRITE_ONCE to
1300 if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
1303 ctx->cached_cq_tail++;
1304 return &rings->cqes[tail & ctx->cq_mask];
1307 static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
1311 if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
1313 if (!ctx->eventfd_async)
1315 return io_wq_current_is_worker();
1318 static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
1320 if (waitqueue_active(&ctx->wait))
1321 wake_up(&ctx->wait);
1322 if (waitqueue_active(&ctx->sqo_wait))
1323 wake_up(&ctx->sqo_wait);
1324 if (io_should_trigger_evfd(ctx))
1325 eventfd_signal(ctx->cq_ev_fd, 1);
1328 static void io_cqring_mark_overflow(struct io_ring_ctx *ctx)
1330 if (list_empty(&ctx->cq_overflow_list)) {
1331 clear_bit(0, &ctx->sq_check_overflow);
1332 clear_bit(0, &ctx->cq_check_overflow);
1333 ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW;
1337 /* Returns true if there are no backlogged entries after the flush */
1338 static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
1340 struct io_rings *rings = ctx->rings;
1341 struct io_uring_cqe *cqe;
1342 struct io_kiocb *req;
1343 unsigned long flags;
1347 if (list_empty_careful(&ctx->cq_overflow_list))
1349 if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) ==
1350 rings->cq_ring_entries))
1354 spin_lock_irqsave(&ctx->completion_lock, flags);
1356 /* if force is set, the ring is going away. always drop after that */
1358 ctx->cq_overflow_flushed = 1;
1361 while (!list_empty(&ctx->cq_overflow_list)) {
1362 cqe = io_get_cqring(ctx);
1366 req = list_first_entry(&ctx->cq_overflow_list, struct io_kiocb,
1368 list_move(&req->compl.list, &list);
1369 req->flags &= ~REQ_F_OVERFLOW;
1371 WRITE_ONCE(cqe->user_data, req->user_data);
1372 WRITE_ONCE(cqe->res, req->result);
1373 WRITE_ONCE(cqe->flags, req->compl.cflags);
1375 WRITE_ONCE(ctx->rings->cq_overflow,
1376 atomic_inc_return(&ctx->cached_cq_overflow));
1380 io_commit_cqring(ctx);
1381 io_cqring_mark_overflow(ctx);
1383 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1384 io_cqring_ev_posted(ctx);
1386 while (!list_empty(&list)) {
1387 req = list_first_entry(&list, struct io_kiocb, compl.list);
1388 list_del(&req->compl.list);
1395 static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags)
1397 struct io_ring_ctx *ctx = req->ctx;
1398 struct io_uring_cqe *cqe;
1400 trace_io_uring_complete(ctx, req->user_data, res);
1403 * If we can't get a cq entry, userspace overflowed the
1404 * submission (by quite a lot). Increment the overflow count in
1407 cqe = io_get_cqring(ctx);
1409 WRITE_ONCE(cqe->user_data, req->user_data);
1410 WRITE_ONCE(cqe->res, res);
1411 WRITE_ONCE(cqe->flags, cflags);
1412 } else if (ctx->cq_overflow_flushed) {
1413 WRITE_ONCE(ctx->rings->cq_overflow,
1414 atomic_inc_return(&ctx->cached_cq_overflow));
1416 if (list_empty(&ctx->cq_overflow_list)) {
1417 set_bit(0, &ctx->sq_check_overflow);
1418 set_bit(0, &ctx->cq_check_overflow);
1419 ctx->rings->sq_flags |= IORING_SQ_CQ_OVERFLOW;
1422 req->flags |= REQ_F_OVERFLOW;
1424 req->compl.cflags = cflags;
1425 refcount_inc(&req->refs);
1426 list_add_tail(&req->compl.list, &ctx->cq_overflow_list);
1430 static void io_cqring_fill_event(struct io_kiocb *req, long res)
1432 __io_cqring_fill_event(req, res, 0);
1435 static void io_cqring_add_event(struct io_kiocb *req, long res, long cflags)
1437 struct io_ring_ctx *ctx = req->ctx;
1438 unsigned long flags;
1440 spin_lock_irqsave(&ctx->completion_lock, flags);
1441 __io_cqring_fill_event(req, res, cflags);
1442 io_commit_cqring(ctx);
1443 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1445 io_cqring_ev_posted(ctx);
1448 static void io_submit_flush_completions(struct io_comp_state *cs)
1450 struct io_ring_ctx *ctx = cs->ctx;
1452 spin_lock_irq(&ctx->completion_lock);
1453 while (!list_empty(&cs->list)) {
1454 struct io_kiocb *req;
1456 req = list_first_entry(&cs->list, struct io_kiocb, compl.list);
1457 list_del(&req->compl.list);
1458 __io_cqring_fill_event(req, req->result, req->compl.cflags);
1459 if (!(req->flags & REQ_F_LINK_HEAD)) {
1460 req->flags |= REQ_F_COMP_LOCKED;
1463 spin_unlock_irq(&ctx->completion_lock);
1465 spin_lock_irq(&ctx->completion_lock);
1468 io_commit_cqring(ctx);
1469 spin_unlock_irq(&ctx->completion_lock);
1471 io_cqring_ev_posted(ctx);
1475 static void __io_req_complete(struct io_kiocb *req, long res, unsigned cflags,
1476 struct io_comp_state *cs)
1479 io_cqring_add_event(req, res, cflags);
1484 req->compl.cflags = cflags;
1485 list_add_tail(&req->compl.list, &cs->list);
1487 io_submit_flush_completions(cs);
1491 static void io_req_complete(struct io_kiocb *req, long res)
1493 __io_req_complete(req, res, 0, NULL);
1496 static inline bool io_is_fallback_req(struct io_kiocb *req)
1498 return req == (struct io_kiocb *)
1499 ((unsigned long) req->ctx->fallback_req & ~1UL);
1502 static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx)
1504 struct io_kiocb *req;
1506 req = ctx->fallback_req;
1507 if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req))
1513 static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx,
1514 struct io_submit_state *state)
1516 gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
1517 struct io_kiocb *req;
1519 if (!state->free_reqs) {
1523 sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs));
1524 ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs);
1527 * Bulk alloc is all-or-nothing. If we fail to get a batch,
1528 * retry single alloc to be on the safe side.
1530 if (unlikely(ret <= 0)) {
1531 state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
1532 if (!state->reqs[0])
1536 state->free_reqs = ret - 1;
1537 req = state->reqs[ret - 1];
1540 req = state->reqs[state->free_reqs];
1545 return io_get_fallback_req(ctx);
1548 static inline void io_put_file(struct io_kiocb *req, struct file *file,
1552 percpu_ref_put(req->fixed_file_refs);
1557 static bool io_dismantle_req(struct io_kiocb *req)
1564 io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE));
1566 if (req->flags & REQ_F_INFLIGHT) {
1567 struct io_ring_ctx *ctx = req->ctx;
1568 unsigned long flags;
1570 spin_lock_irqsave(&ctx->inflight_lock, flags);
1571 list_del(&req->inflight_entry);
1572 if (waitqueue_active(&ctx->inflight_wait))
1573 wake_up(&ctx->inflight_wait);
1574 spin_unlock_irqrestore(&ctx->inflight_lock, flags);
1577 return io_req_clean_work(req);
1580 static void __io_free_req_finish(struct io_kiocb *req)
1582 struct io_ring_ctx *ctx = req->ctx;
1584 __io_put_req_task(req);
1585 if (likely(!io_is_fallback_req(req)))
1586 kmem_cache_free(req_cachep, req);
1588 clear_bit_unlock(0, (unsigned long *) &ctx->fallback_req);
1589 percpu_ref_put(&ctx->refs);
1592 static void io_req_task_file_table_put(struct callback_head *cb)
1594 struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
1595 struct fs_struct *fs = req->work.fs;
1597 spin_lock(&req->work.fs->lock);
1600 spin_unlock(&req->work.fs->lock);
1603 req->work.fs = NULL;
1604 __io_free_req_finish(req);
1607 static void __io_free_req(struct io_kiocb *req)
1609 if (!io_dismantle_req(req)) {
1610 __io_free_req_finish(req);
1614 init_task_work(&req->task_work, io_req_task_file_table_put);
1615 ret = task_work_add(req->task, &req->task_work, TWA_RESUME);
1616 if (unlikely(ret)) {
1617 struct task_struct *tsk;
1619 tsk = io_wq_get_task(req->ctx->io_wq);
1620 task_work_add(tsk, &req->task_work, 0);
1625 static bool io_link_cancel_timeout(struct io_kiocb *req)
1627 struct io_ring_ctx *ctx = req->ctx;
1630 ret = hrtimer_try_to_cancel(&req->io->timeout.timer);
1632 io_cqring_fill_event(req, -ECANCELED);
1633 io_commit_cqring(ctx);
1634 req->flags &= ~REQ_F_LINK_HEAD;
1642 static bool __io_kill_linked_timeout(struct io_kiocb *req)
1644 struct io_kiocb *link;
1647 if (list_empty(&req->link_list))
1649 link = list_first_entry(&req->link_list, struct io_kiocb, link_list);
1650 if (link->opcode != IORING_OP_LINK_TIMEOUT)
1653 list_del_init(&link->link_list);
1654 link->flags |= REQ_F_COMP_LOCKED;
1655 wake_ev = io_link_cancel_timeout(link);
1656 req->flags &= ~REQ_F_LINK_TIMEOUT;
1660 static void io_kill_linked_timeout(struct io_kiocb *req)
1662 struct io_ring_ctx *ctx = req->ctx;
1665 if (!(req->flags & REQ_F_COMP_LOCKED)) {
1666 unsigned long flags;
1668 spin_lock_irqsave(&ctx->completion_lock, flags);
1669 wake_ev = __io_kill_linked_timeout(req);
1670 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1672 wake_ev = __io_kill_linked_timeout(req);
1676 io_cqring_ev_posted(ctx);
1679 static struct io_kiocb *io_req_link_next(struct io_kiocb *req)
1681 struct io_kiocb *nxt;
1684 * The list should never be empty when we are called here. But could
1685 * potentially happen if the chain is messed up, check to be on the
1688 if (unlikely(list_empty(&req->link_list)))
1691 nxt = list_first_entry(&req->link_list, struct io_kiocb, link_list);
1692 list_del_init(&req->link_list);
1693 if (!list_empty(&nxt->link_list))
1694 nxt->flags |= REQ_F_LINK_HEAD;
1699 * Called if REQ_F_LINK_HEAD is set, and we fail the head request
1701 static void __io_fail_links(struct io_kiocb *req)
1703 struct io_ring_ctx *ctx = req->ctx;
1705 while (!list_empty(&req->link_list)) {
1706 struct io_kiocb *link = list_first_entry(&req->link_list,
1707 struct io_kiocb, link_list);
1709 list_del_init(&link->link_list);
1710 trace_io_uring_fail_link(req, link);
1712 io_cqring_fill_event(link, -ECANCELED);
1713 link->flags |= REQ_F_COMP_LOCKED;
1714 __io_double_put_req(link);
1715 req->flags &= ~REQ_F_LINK_TIMEOUT;
1718 io_commit_cqring(ctx);
1719 io_cqring_ev_posted(ctx);
1722 static void io_fail_links(struct io_kiocb *req)
1724 struct io_ring_ctx *ctx = req->ctx;
1726 if (!(req->flags & REQ_F_COMP_LOCKED)) {
1727 unsigned long flags;
1729 spin_lock_irqsave(&ctx->completion_lock, flags);
1730 __io_fail_links(req);
1731 spin_unlock_irqrestore(&ctx->completion_lock, flags);
1733 __io_fail_links(req);
1736 io_cqring_ev_posted(ctx);
1739 static struct io_kiocb *__io_req_find_next(struct io_kiocb *req)
1741 req->flags &= ~REQ_F_LINK_HEAD;
1742 if (req->flags & REQ_F_LINK_TIMEOUT)
1743 io_kill_linked_timeout(req);
1746 * If LINK is set, we have dependent requests in this chain. If we
1747 * didn't fail this request, queue the first one up, moving any other
1748 * dependencies to the next request. In case of failure, fail the rest
1751 if (likely(!(req->flags & REQ_F_FAIL_LINK)))
1752 return io_req_link_next(req);
1757 static struct io_kiocb *io_req_find_next(struct io_kiocb *req)
1759 if (likely(!(req->flags & REQ_F_LINK_HEAD)))
1761 return __io_req_find_next(req);
1764 static int io_req_task_work_add(struct io_kiocb *req, struct callback_head *cb)
1766 struct task_struct *tsk = req->task;
1767 struct io_ring_ctx *ctx = req->ctx;
1771 * SQPOLL kernel thread doesn't need notification, just a wakeup. For
1772 * all other cases, use TWA_SIGNAL unconditionally to ensure we're
1773 * processing task_work. There's no reliable way to tell if TWA_RESUME
1777 if (!(ctx->flags & IORING_SETUP_SQPOLL))
1778 notify = TWA_SIGNAL;
1780 ret = task_work_add(tsk, cb, notify);
1782 wake_up_process(tsk);
1787 static void __io_req_task_cancel(struct io_kiocb *req, int error)
1789 struct io_ring_ctx *ctx = req->ctx;
1791 spin_lock_irq(&ctx->completion_lock);
1792 io_cqring_fill_event(req, error);
1793 io_commit_cqring(ctx);
1794 spin_unlock_irq(&ctx->completion_lock);
1796 io_cqring_ev_posted(ctx);
1797 req_set_fail_links(req);
1798 io_double_put_req(req);
1801 static void io_req_task_cancel(struct callback_head *cb)
1803 struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
1805 __io_req_task_cancel(req, -ECANCELED);
1808 static void __io_req_task_submit(struct io_kiocb *req)
1810 struct io_ring_ctx *ctx = req->ctx;
1812 if (!__io_sq_thread_acquire_mm(ctx)) {
1813 mutex_lock(&ctx->uring_lock);
1814 __io_queue_sqe(req, NULL, NULL);
1815 mutex_unlock(&ctx->uring_lock);
1817 __io_req_task_cancel(req, -EFAULT);
1821 static void io_req_task_submit(struct callback_head *cb)
1823 struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
1824 struct io_ring_ctx *ctx = req->ctx;
1826 __io_req_task_submit(req);
1827 percpu_ref_put(&ctx->refs);
1830 static void io_req_task_queue(struct io_kiocb *req)
1834 init_task_work(&req->task_work, io_req_task_submit);
1835 percpu_ref_get(&req->ctx->refs);
1837 ret = io_req_task_work_add(req, &req->task_work);
1838 if (unlikely(ret)) {
1839 struct task_struct *tsk;
1841 init_task_work(&req->task_work, io_req_task_cancel);
1842 tsk = io_wq_get_task(req->ctx->io_wq);
1843 task_work_add(tsk, &req->task_work, 0);
1844 wake_up_process(tsk);
1848 static void io_queue_next(struct io_kiocb *req)
1850 struct io_kiocb *nxt = io_req_find_next(req);
1853 io_req_task_queue(nxt);
1856 static void io_free_req(struct io_kiocb *req)
1863 void *reqs[IO_IOPOLL_BATCH];
1866 struct task_struct *task;
1870 static inline void io_init_req_batch(struct req_batch *rb)
1877 static void __io_req_free_batch_flush(struct io_ring_ctx *ctx,
1878 struct req_batch *rb)
1880 kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs);
1881 percpu_ref_put_many(&ctx->refs, rb->to_free);
1885 static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
1886 struct req_batch *rb)
1889 __io_req_free_batch_flush(ctx, rb);
1891 put_task_struct_many(rb->task, rb->task_refs);
1896 static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req)
1898 if (unlikely(io_is_fallback_req(req))) {
1902 if (req->flags & REQ_F_LINK_HEAD)
1905 if (req->flags & REQ_F_TASK_PINNED) {
1906 if (req->task != rb->task) {
1908 put_task_struct_many(rb->task, rb->task_refs);
1909 rb->task = req->task;
1913 req->flags &= ~REQ_F_TASK_PINNED;
1916 WARN_ON_ONCE(io_dismantle_req(req));
1917 rb->reqs[rb->to_free++] = req;
1918 if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs)))
1919 __io_req_free_batch_flush(req->ctx, rb);
1923 * Drop reference to request, return next in chain (if there is one) if this
1924 * was the last reference to this request.
1926 static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
1928 struct io_kiocb *nxt = NULL;
1930 if (refcount_dec_and_test(&req->refs)) {
1931 nxt = io_req_find_next(req);
1937 static void io_put_req(struct io_kiocb *req)
1939 if (refcount_dec_and_test(&req->refs))
1943 static struct io_wq_work *io_steal_work(struct io_kiocb *req)
1945 struct io_kiocb *nxt;
1948 * A ref is owned by io-wq in which context we're. So, if that's the
1949 * last one, it's safe to steal next work. False negatives are Ok,
1950 * it just will be re-punted async in io_put_work()
1952 if (refcount_read(&req->refs) != 1)
1955 nxt = io_req_find_next(req);
1956 return nxt ? &nxt->work : NULL;
1960 * Must only be used if we don't need to care about links, usually from
1961 * within the completion handling itself.
1963 static void __io_double_put_req(struct io_kiocb *req)
1965 /* drop both submit and complete references */
1966 if (refcount_sub_and_test(2, &req->refs))
1970 static void io_double_put_req(struct io_kiocb *req)
1972 /* drop both submit and complete references */
1973 if (refcount_sub_and_test(2, &req->refs))
1977 static unsigned io_cqring_events(struct io_ring_ctx *ctx, bool noflush)
1979 struct io_rings *rings = ctx->rings;
1981 if (test_bit(0, &ctx->cq_check_overflow)) {
1983 * noflush == true is from the waitqueue handler, just ensure
1984 * we wake up the task, and the next invocation will flush the
1985 * entries. We cannot safely to it from here.
1987 if (noflush && !list_empty(&ctx->cq_overflow_list))
1990 io_cqring_overflow_flush(ctx, false);
1993 /* See comment at the top of this file */
1995 return ctx->cached_cq_tail - READ_ONCE(rings->cq.head);
1998 static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
2000 struct io_rings *rings = ctx->rings;
2002 /* make sure SQ entry isn't read before tail */
2003 return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
2006 static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf)
2008 unsigned int cflags;
2010 cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
2011 cflags |= IORING_CQE_F_BUFFER;
2012 req->flags &= ~REQ_F_BUFFER_SELECTED;
2017 static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
2019 struct io_buffer *kbuf;
2021 kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
2022 return io_put_kbuf(req, kbuf);
2025 static inline bool io_run_task_work(void)
2027 if (current->task_works) {
2028 __set_current_state(TASK_RUNNING);
2036 static void io_iopoll_queue(struct list_head *again)
2038 struct io_kiocb *req;
2041 req = list_first_entry(again, struct io_kiocb, inflight_entry);
2042 list_del(&req->inflight_entry);
2043 __io_complete_rw(req, -EAGAIN, 0, NULL);
2044 } while (!list_empty(again));
2048 * Find and free completed poll iocbs
2050 static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
2051 struct list_head *done)
2053 struct req_batch rb;
2054 struct io_kiocb *req;
2057 /* order with ->result store in io_complete_rw_iopoll() */
2060 io_init_req_batch(&rb);
2061 while (!list_empty(done)) {
2064 req = list_first_entry(done, struct io_kiocb, inflight_entry);
2065 if (READ_ONCE(req->result) == -EAGAIN) {
2066 req->iopoll_completed = 0;
2067 list_move_tail(&req->inflight_entry, &again);
2070 list_del(&req->inflight_entry);
2072 if (req->flags & REQ_F_BUFFER_SELECTED)
2073 cflags = io_put_rw_kbuf(req);
2075 __io_cqring_fill_event(req, req->result, cflags);
2078 if (refcount_dec_and_test(&req->refs))
2079 io_req_free_batch(&rb, req);
2082 io_commit_cqring(ctx);
2083 if (ctx->flags & IORING_SETUP_SQPOLL)
2084 io_cqring_ev_posted(ctx);
2085 io_req_free_batch_finish(ctx, &rb);
2087 if (!list_empty(&again))
2088 io_iopoll_queue(&again);
2091 static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
2094 struct io_kiocb *req, *tmp;
2100 * Only spin for completions if we don't have multiple devices hanging
2101 * off our complete list, and we're under the requested amount.
2103 spin = !ctx->poll_multi_file && *nr_events < min;
2106 list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) {
2107 struct kiocb *kiocb = &req->rw.kiocb;
2110 * Move completed and retryable entries to our local lists.
2111 * If we find a request that requires polling, break out
2112 * and complete those lists first, if we have entries there.
2114 if (READ_ONCE(req->iopoll_completed)) {
2115 list_move_tail(&req->inflight_entry, &done);
2118 if (!list_empty(&done))
2121 ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
2125 /* iopoll may have completed current req */
2126 if (READ_ONCE(req->iopoll_completed))
2127 list_move_tail(&req->inflight_entry, &done);
2134 if (!list_empty(&done))
2135 io_iopoll_complete(ctx, nr_events, &done);
2141 * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a
2142 * non-spinning poll check - we'll still enter the driver poll loop, but only
2143 * as a non-spinning completion check.
2145 static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events,
2148 while (!list_empty(&ctx->iopoll_list) && !need_resched()) {
2151 ret = io_do_iopoll(ctx, nr_events, min);
2154 if (*nr_events >= min)
2162 * We can't just wait for polled events to come to us, we have to actively
2163 * find and complete them.
2165 static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
2167 if (!(ctx->flags & IORING_SETUP_IOPOLL))
2170 mutex_lock(&ctx->uring_lock);
2171 while (!list_empty(&ctx->iopoll_list)) {
2172 unsigned int nr_events = 0;
2174 io_do_iopoll(ctx, &nr_events, 0);
2176 /* let it sleep and repeat later if can't complete a request */
2180 * Ensure we allow local-to-the-cpu processing to take place,
2181 * in this case we need to ensure that we reap all events.
2182 * Also let task_work, etc. to progress by releasing the mutex
2184 if (need_resched()) {
2185 mutex_unlock(&ctx->uring_lock);
2187 mutex_lock(&ctx->uring_lock);
2190 mutex_unlock(&ctx->uring_lock);
2193 static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
2195 unsigned int nr_events = 0;
2196 int iters = 0, ret = 0;
2199 * We disallow the app entering submit/complete with polling, but we
2200 * still need to lock the ring to prevent racing with polled issue
2201 * that got punted to a workqueue.
2203 mutex_lock(&ctx->uring_lock);
2206 * Don't enter poll loop if we already have events pending.
2207 * If we do, we can potentially be spinning for commands that
2208 * already triggered a CQE (eg in error).
2210 if (io_cqring_events(ctx, false))
2214 * If a submit got punted to a workqueue, we can have the
2215 * application entering polling for a command before it gets
2216 * issued. That app will hold the uring_lock for the duration
2217 * of the poll right here, so we need to take a breather every
2218 * now and then to ensure that the issue has a chance to add
2219 * the poll to the issued list. Otherwise we can spin here
2220 * forever, while the workqueue is stuck trying to acquire the
2223 if (!(++iters & 7)) {
2224 mutex_unlock(&ctx->uring_lock);
2226 mutex_lock(&ctx->uring_lock);
2229 ret = io_iopoll_getevents(ctx, &nr_events, min);
2233 } while (min && !nr_events && !need_resched());
2235 mutex_unlock(&ctx->uring_lock);
2239 static void kiocb_end_write(struct io_kiocb *req)
2242 * Tell lockdep we inherited freeze protection from submission
2245 if (req->flags & REQ_F_ISREG) {
2246 struct inode *inode = file_inode(req->file);
2248 __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
2250 file_end_write(req->file);
2253 static void io_complete_rw_common(struct kiocb *kiocb, long res,
2254 struct io_comp_state *cs)
2256 struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
2259 if (kiocb->ki_flags & IOCB_WRITE)
2260 kiocb_end_write(req);
2262 if (res != req->result)
2263 req_set_fail_links(req);
2264 if (req->flags & REQ_F_BUFFER_SELECTED)
2265 cflags = io_put_rw_kbuf(req);
2266 __io_req_complete(req, res, cflags, cs);
2270 static bool io_resubmit_prep(struct io_kiocb *req, int error)
2272 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
2273 ssize_t ret = -ECANCELED;
2274 struct iov_iter iter;
2282 switch (req->opcode) {
2283 case IORING_OP_READV:
2284 case IORING_OP_READ_FIXED:
2285 case IORING_OP_READ:
2288 case IORING_OP_WRITEV:
2289 case IORING_OP_WRITE_FIXED:
2290 case IORING_OP_WRITE:
2294 printk_once(KERN_WARNING "io_uring: bad opcode in resubmit %d\n",
2299 ret = io_import_iovec(rw, req, &iovec, &iter, false);
2302 ret = io_setup_async_rw(req, iovec, inline_vecs, &iter, false);
2307 req_set_fail_links(req);
2308 io_req_complete(req, ret);
2312 static void io_rw_resubmit(struct callback_head *cb)
2314 struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
2315 struct io_ring_ctx *ctx = req->ctx;
2318 err = io_sq_thread_acquire_mm(ctx, req);
2320 if (io_resubmit_prep(req, err)) {
2321 refcount_inc(&req->refs);
2322 io_queue_async_work(req);
2325 percpu_ref_put(&ctx->refs);
2329 static bool io_rw_reissue(struct io_kiocb *req, long res)
2334 if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker())
2337 init_task_work(&req->task_work, io_rw_resubmit);
2338 percpu_ref_get(&req->ctx->refs);
2340 ret = io_req_task_work_add(req, &req->task_work);
2347 static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
2348 struct io_comp_state *cs)
2350 if (!io_rw_reissue(req, res))
2351 io_complete_rw_common(&req->rw.kiocb, res, cs);
2354 static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
2356 struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
2358 __io_complete_rw(req, res, res2, NULL);
2361 static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
2363 struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
2365 if (kiocb->ki_flags & IOCB_WRITE)
2366 kiocb_end_write(req);
2368 if (res != -EAGAIN && res != req->result)
2369 req_set_fail_links(req);
2371 WRITE_ONCE(req->result, res);
2372 /* order with io_poll_complete() checking ->result */
2374 WRITE_ONCE(req->iopoll_completed, 1);
2378 * After the iocb has been issued, it's safe to be found on the poll list.
2379 * Adding the kiocb to the list AFTER submission ensures that we don't
2380 * find it from a io_iopoll_getevents() thread before the issuer is done
2381 * accessing the kiocb cookie.
2383 static void io_iopoll_req_issued(struct io_kiocb *req)
2385 struct io_ring_ctx *ctx = req->ctx;
2388 * Track whether we have multiple files in our lists. This will impact
2389 * how we do polling eventually, not spinning if we're on potentially
2390 * different devices.
2392 if (list_empty(&ctx->iopoll_list)) {
2393 ctx->poll_multi_file = false;
2394 } else if (!ctx->poll_multi_file) {
2395 struct io_kiocb *list_req;
2397 list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb,
2399 if (list_req->file != req->file)
2400 ctx->poll_multi_file = true;
2404 * For fast devices, IO may have already completed. If it has, add
2405 * it to the front so we find it first.
2407 if (READ_ONCE(req->iopoll_completed))
2408 list_add(&req->inflight_entry, &ctx->iopoll_list);
2410 list_add_tail(&req->inflight_entry, &ctx->iopoll_list);
2412 if ((ctx->flags & IORING_SETUP_SQPOLL) &&
2413 wq_has_sleeper(&ctx->sqo_wait))
2414 wake_up(&ctx->sqo_wait);
2417 static void __io_state_file_put(struct io_submit_state *state)
2419 if (state->has_refs)
2420 fput_many(state->file, state->has_refs);
2424 static inline void io_state_file_put(struct io_submit_state *state)
2427 __io_state_file_put(state);
2431 * Get as many references to a file as we have IOs left in this submission,
2432 * assuming most submissions are for one file, or at least that each file
2433 * has more than one submission.
2435 static struct file *__io_file_get(struct io_submit_state *state, int fd)
2441 if (state->fd == fd) {
2446 __io_state_file_put(state);
2448 state->file = fget_many(fd, state->ios_left);
2454 state->has_refs = state->ios_left;
2458 static bool io_bdev_nowait(struct block_device *bdev)
2461 return !bdev || queue_is_mq(bdev_get_queue(bdev));
2468 * If we tracked the file through the SCM inflight mechanism, we could support
2469 * any file. For now, just ensure that anything potentially problematic is done
2472 static bool io_file_supports_async(struct file *file, int rw)
2474 umode_t mode = file_inode(file)->i_mode;
2476 if (S_ISBLK(mode)) {
2477 if (io_bdev_nowait(file->f_inode->i_bdev))
2481 if (S_ISCHR(mode) || S_ISSOCK(mode))
2483 if (S_ISREG(mode)) {
2484 if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
2485 file->f_op != &io_uring_fops)
2490 /* any ->read/write should understand O_NONBLOCK */
2491 if (file->f_flags & O_NONBLOCK)
2494 if (!(file->f_mode & FMODE_NOWAIT))
2498 return file->f_op->read_iter != NULL;
2500 return file->f_op->write_iter != NULL;
2503 static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
2504 bool force_nonblock)
2506 struct io_ring_ctx *ctx = req->ctx;
2507 struct kiocb *kiocb = &req->rw.kiocb;
2511 if (S_ISREG(file_inode(req->file)->i_mode))
2512 req->flags |= REQ_F_ISREG;
2514 kiocb->ki_pos = READ_ONCE(sqe->off);
2515 if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) {
2516 req->flags |= REQ_F_CUR_POS;
2517 kiocb->ki_pos = req->file->f_pos;
2519 kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
2520 kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
2521 ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
2525 ioprio = READ_ONCE(sqe->ioprio);
2527 ret = ioprio_check_cap(ioprio);
2531 kiocb->ki_ioprio = ioprio;
2533 kiocb->ki_ioprio = get_current_ioprio();
2535 /* don't allow async punt if RWF_NOWAIT was requested */
2536 if (kiocb->ki_flags & IOCB_NOWAIT)
2537 req->flags |= REQ_F_NOWAIT;
2539 if (kiocb->ki_flags & IOCB_DIRECT)
2540 io_get_req_task(req);
2543 kiocb->ki_flags |= IOCB_NOWAIT;
2545 if (ctx->flags & IORING_SETUP_IOPOLL) {
2546 if (!(kiocb->ki_flags & IOCB_DIRECT) ||
2547 !kiocb->ki_filp->f_op->iopoll)
2550 kiocb->ki_flags |= IOCB_HIPRI;
2551 kiocb->ki_complete = io_complete_rw_iopoll;
2552 req->iopoll_completed = 0;
2553 io_get_req_task(req);
2555 if (kiocb->ki_flags & IOCB_HIPRI)
2557 kiocb->ki_complete = io_complete_rw;
2560 req->rw.addr = READ_ONCE(sqe->addr);
2561 req->rw.len = READ_ONCE(sqe->len);
2562 req->buf_index = READ_ONCE(sqe->buf_index);
2566 static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
2572 case -ERESTARTNOINTR:
2573 case -ERESTARTNOHAND:
2574 case -ERESTART_RESTARTBLOCK:
2576 * We can't just restart the syscall, since previously
2577 * submitted sqes may already be in progress. Just fail this
2583 kiocb->ki_complete(kiocb, ret, 0);
2587 static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
2588 struct io_comp_state *cs)
2590 struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
2592 /* add previously done IO, if any */
2593 if (req->io && req->io->rw.bytes_done > 0) {
2595 ret = req->io->rw.bytes_done;
2597 ret += req->io->rw.bytes_done;
2600 if (req->flags & REQ_F_CUR_POS)
2601 req->file->f_pos = kiocb->ki_pos;
2602 if (ret >= 0 && kiocb->ki_complete == io_complete_rw)
2603 __io_complete_rw(req, ret, 0, cs);
2605 io_rw_done(kiocb, ret);
2608 static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
2609 struct iov_iter *iter)
2611 struct io_ring_ctx *ctx = req->ctx;
2612 size_t len = req->rw.len;
2613 struct io_mapped_ubuf *imu;
2614 u16 index, buf_index;
2618 /* attempt to use fixed buffers without having provided iovecs */
2619 if (unlikely(!ctx->user_bufs))
2622 buf_index = req->buf_index;
2623 if (unlikely(buf_index >= ctx->nr_user_bufs))
2626 index = array_index_nospec(buf_index, ctx->nr_user_bufs);
2627 imu = &ctx->user_bufs[index];
2628 buf_addr = req->rw.addr;
2631 if (buf_addr + len < buf_addr)
2633 /* not inside the mapped region */
2634 if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len)
2638 * May not be a start of buffer, set size appropriately
2639 * and advance us to the beginning.
2641 offset = buf_addr - imu->ubuf;
2642 iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
2646 * Don't use iov_iter_advance() here, as it's really slow for
2647 * using the latter parts of a big fixed buffer - it iterates
2648 * over each segment manually. We can cheat a bit here, because
2651 * 1) it's a BVEC iter, we set it up
2652 * 2) all bvecs are PAGE_SIZE in size, except potentially the
2653 * first and last bvec
2655 * So just find our index, and adjust the iterator afterwards.
2656 * If the offset is within the first bvec (or the whole first
2657 * bvec, just use iov_iter_advance(). This makes it easier
2658 * since we can just skip the first segment, which may not
2659 * be PAGE_SIZE aligned.
2661 const struct bio_vec *bvec = imu->bvec;
2663 if (offset <= bvec->bv_len) {
2664 iov_iter_advance(iter, offset);
2666 unsigned long seg_skip;
2668 /* skip first vec */
2669 offset -= bvec->bv_len;
2670 seg_skip = 1 + (offset >> PAGE_SHIFT);
2672 iter->bvec = bvec + seg_skip;
2673 iter->nr_segs -= seg_skip;
2674 iter->count -= bvec->bv_len + offset;
2675 iter->iov_offset = offset & ~PAGE_MASK;
2682 static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
2685 mutex_unlock(&ctx->uring_lock);
2688 static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
2691 * "Normal" inline submissions always hold the uring_lock, since we
2692 * grab it from the system call. Same is true for the SQPOLL offload.
2693 * The only exception is when we've detached the request and issue it
2694 * from an async worker thread, grab the lock for that case.
2697 mutex_lock(&ctx->uring_lock);
2700 static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
2701 int bgid, struct io_buffer *kbuf,
2704 struct io_buffer *head;
2706 if (req->flags & REQ_F_BUFFER_SELECTED)
2709 io_ring_submit_lock(req->ctx, needs_lock);
2711 lockdep_assert_held(&req->ctx->uring_lock);
2713 head = idr_find(&req->ctx->io_buffer_idr, bgid);
2715 if (!list_empty(&head->list)) {
2716 kbuf = list_last_entry(&head->list, struct io_buffer,
2718 list_del(&kbuf->list);
2721 idr_remove(&req->ctx->io_buffer_idr, bgid);
2723 if (*len > kbuf->len)
2726 kbuf = ERR_PTR(-ENOBUFS);
2729 io_ring_submit_unlock(req->ctx, needs_lock);
2734 static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
2737 struct io_buffer *kbuf;
2740 kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
2741 bgid = req->buf_index;
2742 kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
2745 req->rw.addr = (u64) (unsigned long) kbuf;
2746 req->flags |= REQ_F_BUFFER_SELECTED;
2747 return u64_to_user_ptr(kbuf->addr);
2750 #ifdef CONFIG_COMPAT
2751 static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
2754 struct compat_iovec __user *uiov;
2755 compat_ssize_t clen;
2759 uiov = u64_to_user_ptr(req->rw.addr);
2760 if (!access_ok(uiov, sizeof(*uiov)))
2762 if (__get_user(clen, &uiov->iov_len))
2768 buf = io_rw_buffer_select(req, &len, needs_lock);
2770 return PTR_ERR(buf);
2771 iov[0].iov_base = buf;
2772 iov[0].iov_len = (compat_size_t) len;
2777 static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
2780 struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
2784 if (copy_from_user(iov, uiov, sizeof(*uiov)))
2787 len = iov[0].iov_len;
2790 buf = io_rw_buffer_select(req, &len, needs_lock);
2792 return PTR_ERR(buf);
2793 iov[0].iov_base = buf;
2794 iov[0].iov_len = len;
2798 static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
2801 if (req->flags & REQ_F_BUFFER_SELECTED) {
2802 struct io_buffer *kbuf;
2804 kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
2805 iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
2806 iov[0].iov_len = kbuf->len;
2811 else if (req->rw.len > 1)
2814 #ifdef CONFIG_COMPAT
2815 if (req->ctx->compat)
2816 return io_compat_import(req, iov, needs_lock);
2819 return __io_iov_buffer_select(req, iov, needs_lock);
2822 static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
2823 struct iovec **iovec, struct iov_iter *iter,
2826 void __user *buf = u64_to_user_ptr(req->rw.addr);
2827 size_t sqe_len = req->rw.len;
2832 struct io_async_rw *iorw = &req->io->rw;
2835 return iov_iter_count(&iorw->iter);
2838 opcode = req->opcode;
2839 if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
2841 return io_import_fixed(req, rw, iter);
2844 /* buffer index only valid with fixed read/write, or buffer select */
2845 if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
2848 if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
2849 if (req->flags & REQ_F_BUFFER_SELECT) {
2850 buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
2853 return PTR_ERR(buf);
2855 req->rw.len = sqe_len;
2858 ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
2860 return ret < 0 ? ret : sqe_len;
2863 if (req->flags & REQ_F_BUFFER_SELECT) {
2864 ret = io_iov_buffer_select(req, *iovec, needs_lock);
2866 ret = (*iovec)->iov_len;
2867 iov_iter_init(iter, rw, *iovec, 1, ret);
2873 #ifdef CONFIG_COMPAT
2874 if (req->ctx->compat)
2875 return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
2879 return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter);
2883 * For files that don't have ->read_iter() and ->write_iter(), handle them
2884 * by looping over ->read() or ->write() manually.
2886 static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb,
2887 struct iov_iter *iter)
2892 * Don't support polled IO through this interface, and we can't
2893 * support non-blocking either. For the latter, this just causes
2894 * the kiocb to be handled from an async context.
2896 if (kiocb->ki_flags & IOCB_HIPRI)
2898 if (kiocb->ki_flags & IOCB_NOWAIT)
2901 while (iov_iter_count(iter)) {
2905 if (!iov_iter_is_bvec(iter)) {
2906 iovec = iov_iter_iovec(iter);
2908 /* fixed buffers import bvec */
2909 iovec.iov_base = kmap(iter->bvec->bv_page)
2911 iovec.iov_len = min(iter->count,
2912 iter->bvec->bv_len - iter->iov_offset);
2916 nr = file->f_op->read(file, iovec.iov_base,
2917 iovec.iov_len, &kiocb->ki_pos);
2919 nr = file->f_op->write(file, iovec.iov_base,
2920 iovec.iov_len, &kiocb->ki_pos);
2923 if (iov_iter_is_bvec(iter))
2924 kunmap(iter->bvec->bv_page);
2932 if (nr != iovec.iov_len)
2934 iov_iter_advance(iter, nr);
2940 static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
2941 const struct iovec *fast_iov, struct iov_iter *iter)
2943 struct io_async_rw *rw = &req->io->rw;
2945 memcpy(&rw->iter, iter, sizeof(*iter));
2946 rw->free_iovec = NULL;
2948 /* can only be fixed buffers, no need to do anything */
2949 if (iter->type == ITER_BVEC)
2952 unsigned iov_off = 0;
2954 rw->iter.iov = rw->fast_iov;
2955 if (iter->iov != fast_iov) {
2956 iov_off = iter->iov - fast_iov;
2957 rw->iter.iov += iov_off;
2959 if (rw->fast_iov != fast_iov)
2960 memcpy(rw->fast_iov + iov_off, fast_iov + iov_off,
2961 sizeof(struct iovec) * iter->nr_segs);
2963 rw->free_iovec = iovec;
2964 req->flags |= REQ_F_NEED_CLEANUP;
2968 static inline int __io_alloc_async_ctx(struct io_kiocb *req)
2970 req->io = kmalloc(sizeof(*req->io), GFP_KERNEL);
2971 return req->io == NULL;
2974 static int io_alloc_async_ctx(struct io_kiocb *req)
2976 if (!io_op_defs[req->opcode].async_ctx)
2979 return __io_alloc_async_ctx(req);
2982 static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
2983 const struct iovec *fast_iov,
2984 struct iov_iter *iter, bool force)
2986 if (!force && !io_op_defs[req->opcode].async_ctx)
2989 if (__io_alloc_async_ctx(req))
2992 io_req_map_rw(req, iovec, fast_iov, iter);
2997 static inline int io_rw_prep_async(struct io_kiocb *req, int rw,
2998 bool force_nonblock)
3000 struct io_async_rw *iorw = &req->io->rw;
3003 iorw->iter.iov = iorw->fast_iov;
3004 /* reset ->io around the iovec import, we don't want to use it */
3006 ret = io_import_iovec(rw, req, (struct iovec **) &iorw->iter.iov,
3007 &iorw->iter, !force_nonblock);
3008 req->io = container_of(iorw, struct io_async_ctx, rw);
3009 if (unlikely(ret < 0))
3012 io_req_map_rw(req, iorw->iter.iov, iorw->fast_iov, &iorw->iter);
3016 static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
3017 bool force_nonblock)
3021 ret = io_prep_rw(req, sqe, force_nonblock);
3025 if (unlikely(!(req->file->f_mode & FMODE_READ)))
3028 /* either don't need iovec imported or already have it */
3029 if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
3031 return io_rw_prep_async(req, READ, force_nonblock);
3035 * This is our waitqueue callback handler, registered through lock_page_async()
3036 * when we initially tried to do the IO with the iocb armed our waitqueue.
3037 * This gets called when the page is unlocked, and we generally expect that to
3038 * happen when the page IO is completed and the page is now uptodate. This will
3039 * queue a task_work based retry of the operation, attempting to copy the data
3040 * again. If the latter fails because the page was NOT uptodate, then we will
3041 * do a thread based blocking retry of the operation. That's the unexpected
3044 static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
3045 int sync, void *arg)
3047 struct wait_page_queue *wpq;
3048 struct io_kiocb *req = wait->private;
3049 struct wait_page_key *key = arg;
3052 wpq = container_of(wait, struct wait_page_queue, wait);
3054 if (!wake_page_match(wpq, key))
3057 list_del_init(&wait->entry);
3059 init_task_work(&req->task_work, io_req_task_submit);
3060 percpu_ref_get(&req->ctx->refs);
3062 /* submit ref gets dropped, acquire a new one */
3063 refcount_inc(&req->refs);
3064 ret = io_req_task_work_add(req, &req->task_work);
3065 if (unlikely(ret)) {
3066 struct task_struct *tsk;
3068 /* queue just for cancelation */
3069 init_task_work(&req->task_work, io_req_task_cancel);
3070 tsk = io_wq_get_task(req->ctx->io_wq);
3071 task_work_add(tsk, &req->task_work, 0);
3072 wake_up_process(tsk);
3077 static inline int kiocb_wait_page_queue_init(struct kiocb *kiocb,
3078 struct wait_page_queue *wait,
3079 wait_queue_func_t func,
3082 /* Can't support async wakeup with polled IO */
3083 if (kiocb->ki_flags & IOCB_HIPRI)
3085 if (kiocb->ki_filp->f_mode & FMODE_BUF_RASYNC) {
3086 wait->wait.func = func;
3087 wait->wait.private = data;
3088 wait->wait.flags = 0;
3089 INIT_LIST_HEAD(&wait->wait.entry);
3090 kiocb->ki_flags |= IOCB_WAITQ;
3091 kiocb->ki_waitq = wait;
3099 * This controls whether a given IO request should be armed for async page
3100 * based retry. If we return false here, the request is handed to the async
3101 * worker threads for retry. If we're doing buffered reads on a regular file,
3102 * we prepare a private wait_page_queue entry and retry the operation. This
3103 * will either succeed because the page is now uptodate and unlocked, or it
3104 * will register a callback when the page is unlocked at IO completion. Through
3105 * that callback, io_uring uses task_work to setup a retry of the operation.
3106 * That retry will attempt the buffered read again. The retry will generally
3107 * succeed, or in rare cases where it fails, we then fall back to using the
3108 * async worker threads for a blocking retry.
3110 static bool io_rw_should_retry(struct io_kiocb *req)
3112 struct kiocb *kiocb = &req->rw.kiocb;
3115 /* never retry for NOWAIT, we just complete with -EAGAIN */
3116 if (req->flags & REQ_F_NOWAIT)
3119 /* Only for buffered IO */
3120 if (kiocb->ki_flags & IOCB_DIRECT)
3123 * just use poll if we can, and don't attempt if the fs doesn't
3124 * support callback based unlocks
3126 if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
3129 ret = kiocb_wait_page_queue_init(kiocb, &req->io->rw.wpq,
3130 io_async_buf_func, req);
3132 io_get_req_task(req);
3139 static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter)
3141 if (req->file->f_op->read_iter)
3142 return call_read_iter(req->file, &req->rw.kiocb, iter);
3143 else if (req->file->f_op->read)
3144 return loop_rw_iter(READ, req->file, &req->rw.kiocb, iter);
3149 static int io_read(struct io_kiocb *req, bool force_nonblock,
3150 struct io_comp_state *cs)
3152 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
3153 struct kiocb *kiocb = &req->rw.kiocb;
3154 struct iov_iter __iter, *iter = &__iter;
3155 ssize_t io_size, ret, ret2;
3159 iter = &req->io->rw.iter;
3161 ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock);
3165 req->result = io_size;
3168 /* Ensure we clear previously set non-block flag */
3169 if (!force_nonblock)
3170 kiocb->ki_flags &= ~IOCB_NOWAIT;
3172 /* If the file doesn't support async, just async punt */
3173 if (force_nonblock && !io_file_supports_async(req->file, READ))
3176 iov_count = iov_iter_count(iter);
3177 ret = rw_verify_area(READ, req->file, &kiocb->ki_pos, iov_count);
3181 ret = io_iter_do_read(req, iter);
3185 } else if (ret == -EIOCBQUEUED) {
3188 } else if (ret == -EAGAIN) {
3189 if (!force_nonblock)
3191 ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
3195 } else if (ret < 0) {
3199 /* read it all, or we did blocking attempt. no retry. */
3200 if (!iov_iter_count(iter) || !force_nonblock ||
3201 (req->file->f_flags & O_NONBLOCK))
3206 ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
3211 /* it's copied and will be cleaned with ->io */
3213 /* now use our persistent iterator, if we aren't already */
3214 iter = &req->io->rw.iter;
3216 req->io->rw.bytes_done += ret;
3217 /* if we can retry, do so with the callbacks armed */
3218 if (!io_rw_should_retry(req)) {
3219 kiocb->ki_flags &= ~IOCB_WAITQ;
3224 * Now retry read with the IOCB_WAITQ parts set in the iocb. If we
3225 * get -EIOCBQUEUED, then we'll get a notification when the desired
3226 * page gets unlocked. We can also get a partial read here, and if we
3227 * do, then just retry at the new offset.
3229 ret = io_iter_do_read(req, iter);
3230 if (ret == -EIOCBQUEUED) {
3233 } else if (ret > 0 && ret < io_size) {
3234 /* we got some bytes, but not all. retry. */
3238 kiocb_done(kiocb, ret, cs);
3246 static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
3247 bool force_nonblock)
3251 ret = io_prep_rw(req, sqe, force_nonblock);
3255 if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
3258 /* either don't need iovec imported or already have it */
3259 if (!req->io || req->flags & REQ_F_NEED_CLEANUP)
3261 return io_rw_prep_async(req, WRITE, force_nonblock);
3264 static int io_write(struct io_kiocb *req, bool force_nonblock,
3265 struct io_comp_state *cs)
3267 struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
3268 struct kiocb *kiocb = &req->rw.kiocb;
3269 struct iov_iter __iter, *iter = &__iter;
3271 ssize_t ret, ret2, io_size;
3274 iter = &req->io->rw.iter;
3276 ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock);
3280 req->result = io_size;
3282 /* Ensure we clear previously set non-block flag */
3283 if (!force_nonblock)
3284 req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT;
3286 /* If the file doesn't support async, just async punt */
3287 if (force_nonblock && !io_file_supports_async(req->file, WRITE))
3290 /* file path doesn't support NOWAIT for non-direct_IO */
3291 if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
3292 (req->flags & REQ_F_ISREG))
3295 iov_count = iov_iter_count(iter);
3296 ret = rw_verify_area(WRITE, req->file, &kiocb->ki_pos, iov_count);
3301 * Open-code file_start_write here to grab freeze protection,
3302 * which will be released by another thread in
3303 * io_complete_rw(). Fool lockdep by telling it the lock got
3304 * released so that it doesn't complain about the held lock when
3305 * we return to userspace.
3307 if (req->flags & REQ_F_ISREG) {
3308 __sb_start_write(file_inode(req->file)->i_sb,
3309 SB_FREEZE_WRITE, true);
3310 __sb_writers_release(file_inode(req->file)->i_sb,
3313 kiocb->ki_flags |= IOCB_WRITE;
3315 if (req->file->f_op->write_iter)
3316 ret2 = call_write_iter(req->file, kiocb, iter);
3317 else if (req->file->f_op->write)
3318 ret2 = loop_rw_iter(WRITE, req->file, kiocb, iter);
3323 * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
3324 * retry them without IOCB_NOWAIT.
3326 if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
3328 if (!force_nonblock || ret2 != -EAGAIN) {
3329 kiocb_done(kiocb, ret2, cs);
3332 ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
3342 static int __io_splice_prep(struct io_kiocb *req,
3343 const struct io_uring_sqe *sqe)
3345 struct io_splice* sp = &req->splice;
3346 unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
3349 if (req->flags & REQ_F_NEED_CLEANUP)
3351 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3355 sp->len = READ_ONCE(sqe->len);
3356 sp->flags = READ_ONCE(sqe->splice_flags);
3358 if (unlikely(sp->flags & ~valid_flags))
3361 ret = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in), &sp->file_in,
3362 (sp->flags & SPLICE_F_FD_IN_FIXED));
3365 req->flags |= REQ_F_NEED_CLEANUP;
3367 if (!S_ISREG(file_inode(sp->file_in)->i_mode)) {
3369 * Splice operation will be punted aync, and here need to
3370 * modify io_wq_work.flags, so initialize io_wq_work firstly.
3372 io_req_init_async(req);
3373 req->work.flags |= IO_WQ_WORK_UNBOUND;
3379 static int io_tee_prep(struct io_kiocb *req,
3380 const struct io_uring_sqe *sqe)
3382 if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
3384 return __io_splice_prep(req, sqe);
3387 static int io_tee(struct io_kiocb *req, bool force_nonblock)
3389 struct io_splice *sp = &req->splice;
3390 struct file *in = sp->file_in;
3391 struct file *out = sp->file_out;
3392 unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
3398 ret = do_tee(in, out, sp->len, flags);
3400 io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
3401 req->flags &= ~REQ_F_NEED_CLEANUP;
3404 req_set_fail_links(req);
3405 io_req_complete(req, ret);
3409 static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3411 struct io_splice* sp = &req->splice;
3413 sp->off_in = READ_ONCE(sqe->splice_off_in);
3414 sp->off_out = READ_ONCE(sqe->off);
3415 return __io_splice_prep(req, sqe);
3418 static int io_splice(struct io_kiocb *req, bool force_nonblock)
3420 struct io_splice *sp = &req->splice;
3421 struct file *in = sp->file_in;
3422 struct file *out = sp->file_out;
3423 unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
3424 loff_t *poff_in, *poff_out;
3430 poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
3431 poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
3434 ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
3436 io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
3437 req->flags &= ~REQ_F_NEED_CLEANUP;
3440 req_set_fail_links(req);
3441 io_req_complete(req, ret);
3446 * IORING_OP_NOP just posts a completion event, nothing else.
3448 static int io_nop(struct io_kiocb *req, struct io_comp_state *cs)
3450 struct io_ring_ctx *ctx = req->ctx;
3452 if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
3455 __io_req_complete(req, 0, 0, cs);
3459 static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3461 struct io_ring_ctx *ctx = req->ctx;
3466 if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
3468 if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
3471 req->sync.flags = READ_ONCE(sqe->fsync_flags);
3472 if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
3475 req->sync.off = READ_ONCE(sqe->off);
3476 req->sync.len = READ_ONCE(sqe->len);
3480 static int io_fsync(struct io_kiocb *req, bool force_nonblock)
3482 loff_t end = req->sync.off + req->sync.len;
3485 /* fsync always requires a blocking context */
3489 ret = vfs_fsync_range(req->file, req->sync.off,
3490 end > 0 ? end : LLONG_MAX,
3491 req->sync.flags & IORING_FSYNC_DATASYNC);
3493 req_set_fail_links(req);
3494 io_req_complete(req, ret);
3498 static int io_fallocate_prep(struct io_kiocb *req,
3499 const struct io_uring_sqe *sqe)
3501 if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
3503 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3506 req->sync.off = READ_ONCE(sqe->off);
3507 req->sync.len = READ_ONCE(sqe->addr);
3508 req->sync.mode = READ_ONCE(sqe->len);
3512 static int io_fallocate(struct io_kiocb *req, bool force_nonblock)
3516 /* fallocate always requiring blocking context */
3519 ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
3522 req_set_fail_links(req);
3523 io_req_complete(req, ret);
3527 static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3529 const char __user *fname;
3532 if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
3534 if (unlikely(sqe->ioprio || sqe->buf_index))
3536 if (unlikely(req->flags & REQ_F_FIXED_FILE))
3539 /* open.how should be already initialised */
3540 if (!(req->open.how.flags & O_PATH) && force_o_largefile())
3541 req->open.how.flags |= O_LARGEFILE;
3543 req->open.dfd = READ_ONCE(sqe->fd);
3544 fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
3545 req->open.filename = getname(fname);
3546 if (IS_ERR(req->open.filename)) {
3547 ret = PTR_ERR(req->open.filename);
3548 req->open.filename = NULL;
3551 req->open.nofile = rlimit(RLIMIT_NOFILE);
3552 req->flags |= REQ_F_NEED_CLEANUP;
3556 static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3560 if (req->flags & REQ_F_NEED_CLEANUP)
3562 mode = READ_ONCE(sqe->len);
3563 flags = READ_ONCE(sqe->open_flags);
3564 req->open.how = build_open_how(flags, mode);
3565 return __io_openat_prep(req, sqe);
3568 static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3570 struct open_how __user *how;
3574 if (req->flags & REQ_F_NEED_CLEANUP)
3576 how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
3577 len = READ_ONCE(sqe->len);
3578 if (len < OPEN_HOW_SIZE_VER0)
3581 ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
3586 return __io_openat_prep(req, sqe);
3589 static int io_openat2(struct io_kiocb *req, bool force_nonblock)
3591 struct open_flags op;
3598 ret = build_open_flags(&req->open.how, &op);
3602 ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
3606 file = do_filp_open(req->open.dfd, req->open.filename, &op);
3609 ret = PTR_ERR(file);
3611 fsnotify_open(file);
3612 fd_install(ret, file);
3615 putname(req->open.filename);
3616 req->flags &= ~REQ_F_NEED_CLEANUP;
3618 req_set_fail_links(req);
3619 io_req_complete(req, ret);
3623 static int io_openat(struct io_kiocb *req, bool force_nonblock)
3625 return io_openat2(req, force_nonblock);
3628 static int io_remove_buffers_prep(struct io_kiocb *req,
3629 const struct io_uring_sqe *sqe)
3631 struct io_provide_buf *p = &req->pbuf;
3634 if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off)
3637 tmp = READ_ONCE(sqe->fd);
3638 if (!tmp || tmp > USHRT_MAX)
3641 memset(p, 0, sizeof(*p));
3643 p->bgid = READ_ONCE(sqe->buf_group);
3647 static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
3648 int bgid, unsigned nbufs)
3652 /* shouldn't happen */
3656 /* the head kbuf is the list itself */
3657 while (!list_empty(&buf->list)) {
3658 struct io_buffer *nxt;
3660 nxt = list_first_entry(&buf->list, struct io_buffer, list);
3661 list_del(&nxt->list);
3668 idr_remove(&ctx->io_buffer_idr, bgid);
3673 static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock,
3674 struct io_comp_state *cs)
3676 struct io_provide_buf *p = &req->pbuf;
3677 struct io_ring_ctx *ctx = req->ctx;
3678 struct io_buffer *head;
3681 io_ring_submit_lock(ctx, !force_nonblock);
3683 lockdep_assert_held(&ctx->uring_lock);
3686 head = idr_find(&ctx->io_buffer_idr, p->bgid);
3688 ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
3690 io_ring_submit_lock(ctx, !force_nonblock);
3692 req_set_fail_links(req);
3693 __io_req_complete(req, ret, 0, cs);
3697 static int io_provide_buffers_prep(struct io_kiocb *req,
3698 const struct io_uring_sqe *sqe)
3700 struct io_provide_buf *p = &req->pbuf;
3703 if (sqe->ioprio || sqe->rw_flags)
3706 tmp = READ_ONCE(sqe->fd);
3707 if (!tmp || tmp > USHRT_MAX)
3710 p->addr = READ_ONCE(sqe->addr);
3711 p->len = READ_ONCE(sqe->len);
3713 if (!access_ok(u64_to_user_ptr(p->addr), (p->len * p->nbufs)))
3716 p->bgid = READ_ONCE(sqe->buf_group);
3717 tmp = READ_ONCE(sqe->off);
3718 if (tmp > USHRT_MAX)
3724 static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
3726 struct io_buffer *buf;
3727 u64 addr = pbuf->addr;
3728 int i, bid = pbuf->bid;
3730 for (i = 0; i < pbuf->nbufs; i++) {
3731 buf = kmalloc(sizeof(*buf), GFP_KERNEL);
3736 buf->len = pbuf->len;
3741 INIT_LIST_HEAD(&buf->list);
3744 list_add_tail(&buf->list, &(*head)->list);
3748 return i ? i : -ENOMEM;
3751 static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock,
3752 struct io_comp_state *cs)
3754 struct io_provide_buf *p = &req->pbuf;
3755 struct io_ring_ctx *ctx = req->ctx;
3756 struct io_buffer *head, *list;
3759 io_ring_submit_lock(ctx, !force_nonblock);
3761 lockdep_assert_held(&ctx->uring_lock);
3763 list = head = idr_find(&ctx->io_buffer_idr, p->bgid);
3765 ret = io_add_buffers(p, &head);
3770 ret = idr_alloc(&ctx->io_buffer_idr, head, p->bgid, p->bgid + 1,
3773 __io_remove_buffers(ctx, head, p->bgid, -1U);
3778 io_ring_submit_unlock(ctx, !force_nonblock);
3780 req_set_fail_links(req);
3781 __io_req_complete(req, ret, 0, cs);
3785 static int io_epoll_ctl_prep(struct io_kiocb *req,
3786 const struct io_uring_sqe *sqe)
3788 #if defined(CONFIG_EPOLL)
3789 if (sqe->ioprio || sqe->buf_index)
3791 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3794 req->epoll.epfd = READ_ONCE(sqe->fd);
3795 req->epoll.op = READ_ONCE(sqe->len);
3796 req->epoll.fd = READ_ONCE(sqe->off);
3798 if (ep_op_has_event(req->epoll.op)) {
3799 struct epoll_event __user *ev;
3801 ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
3802 if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
3812 static int io_epoll_ctl(struct io_kiocb *req, bool force_nonblock,
3813 struct io_comp_state *cs)
3815 #if defined(CONFIG_EPOLL)
3816 struct io_epoll *ie = &req->epoll;
3819 ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
3820 if (force_nonblock && ret == -EAGAIN)
3824 req_set_fail_links(req);
3825 __io_req_complete(req, ret, 0, cs);
3832 static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3834 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
3835 if (sqe->ioprio || sqe->buf_index || sqe->off)
3837 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3840 req->madvise.addr = READ_ONCE(sqe->addr);
3841 req->madvise.len = READ_ONCE(sqe->len);
3842 req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
3849 static int io_madvise(struct io_kiocb *req, bool force_nonblock)
3851 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
3852 struct io_madvise *ma = &req->madvise;
3858 ret = do_madvise(ma->addr, ma->len, ma->advice);
3860 req_set_fail_links(req);
3861 io_req_complete(req, ret);
3868 static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3870 if (sqe->ioprio || sqe->buf_index || sqe->addr)
3872 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3875 req->fadvise.offset = READ_ONCE(sqe->off);
3876 req->fadvise.len = READ_ONCE(sqe->len);
3877 req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
3881 static int io_fadvise(struct io_kiocb *req, bool force_nonblock)
3883 struct io_fadvise *fa = &req->fadvise;
3886 if (force_nonblock) {
3887 switch (fa->advice) {
3888 case POSIX_FADV_NORMAL:
3889 case POSIX_FADV_RANDOM:
3890 case POSIX_FADV_SEQUENTIAL:
3897 ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
3899 req_set_fail_links(req);
3900 io_req_complete(req, ret);
3904 static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3906 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
3908 if (sqe->ioprio || sqe->buf_index)
3910 if (req->flags & REQ_F_FIXED_FILE)
3913 req->statx.dfd = READ_ONCE(sqe->fd);
3914 req->statx.mask = READ_ONCE(sqe->len);
3915 req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));
3916 req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
3917 req->statx.flags = READ_ONCE(sqe->statx_flags);
3922 static int io_statx(struct io_kiocb *req, bool force_nonblock)
3924 struct io_statx *ctx = &req->statx;
3927 if (force_nonblock) {
3928 /* only need file table for an actual valid fd */
3929 if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
3930 req->flags |= REQ_F_NO_FILE_TABLE;
3934 ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
3938 req_set_fail_links(req);
3939 io_req_complete(req, ret);
3943 static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
3946 * If we queue this for async, it must not be cancellable. That would
3947 * leave the 'file' in an undeterminate state, and here need to modify
3948 * io_wq_work.flags, so initialize io_wq_work firstly.
3950 io_req_init_async(req);
3951 req->work.flags |= IO_WQ_WORK_NO_CANCEL;
3953 if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
3955 if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
3956 sqe->rw_flags || sqe->buf_index)
3958 if (req->flags & REQ_F_FIXED_FILE)
3961 req->close.fd = READ_ONCE(sqe->fd);
3962 if ((req->file && req->file->f_op == &io_uring_fops) ||
3963 req->close.fd == req->ctx->ring_fd)
3966 req->close.put_file = NULL;
3970 static int io_close(struct io_kiocb *req, bool force_nonblock,
3971 struct io_comp_state *cs)
3973 struct io_close *close = &req->close;
3976 /* might be already done during nonblock submission */
3977 if (!close->put_file) {
3978 ret = __close_fd_get_file(close->fd, &close->put_file);
3980 return (ret == -ENOENT) ? -EBADF : ret;
3983 /* if the file has a flush method, be safe and punt to async */
3984 if (close->put_file->f_op->flush && force_nonblock) {
3985 /* was never set, but play safe */
3986 req->flags &= ~REQ_F_NOWAIT;
3987 /* avoid grabbing files - we don't need the files */
3988 req->flags |= REQ_F_NO_FILE_TABLE;
3992 /* No ->flush() or already async, safely close from here */
3993 ret = filp_close(close->put_file, req->work.files);
3995 req_set_fail_links(req);
3996 fput(close->put_file);
3997 close->put_file = NULL;
3998 __io_req_complete(req, ret, 0, cs);
4002 static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4004 struct io_ring_ctx *ctx = req->ctx;
4009 if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
4011 if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index))
4014 req->sync.off = READ_ONCE(sqe->off);
4015 req->sync.len = READ_ONCE(sqe->len);
4016 req->sync.flags = READ_ONCE(sqe->sync_range_flags);
4020 static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
4024 /* sync_file_range always requires a blocking context */
4028 ret = sync_file_range(req->file, req->sync.off, req->sync.len,
4031 req_set_fail_links(req);
4032 io_req_complete(req, ret);
4036 #if defined(CONFIG_NET)
4037 static int io_setup_async_msg(struct io_kiocb *req,
4038 struct io_async_msghdr *kmsg)
4042 if (io_alloc_async_ctx(req)) {
4043 if (kmsg->iov != kmsg->fast_iov)
4047 req->flags |= REQ_F_NEED_CLEANUP;
4048 memcpy(&req->io->msg, kmsg, sizeof(*kmsg));
4052 static int io_sendmsg_copy_hdr(struct io_kiocb *req,
4053 struct io_async_msghdr *iomsg)
4055 iomsg->iov = iomsg->fast_iov;
4056 iomsg->msg.msg_name = &iomsg->addr;
4057 return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg,
4058 req->sr_msg.msg_flags, &iomsg->iov);
4061 static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4063 struct io_sr_msg *sr = &req->sr_msg;
4064 struct io_async_ctx *io = req->io;
4067 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
4070 sr->msg_flags = READ_ONCE(sqe->msg_flags);
4071 sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
4072 sr->len = READ_ONCE(sqe->len);
4074 #ifdef CONFIG_COMPAT
4075 if (req->ctx->compat)
4076 sr->msg_flags |= MSG_CMSG_COMPAT;
4079 if (!io || req->opcode == IORING_OP_SEND)
4081 /* iovec is already imported */
4082 if (req->flags & REQ_F_NEED_CLEANUP)
4085 ret = io_sendmsg_copy_hdr(req, &io->msg);
4087 req->flags |= REQ_F_NEED_CLEANUP;
4091 static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
4092 struct io_comp_state *cs)
4094 struct io_async_msghdr iomsg, *kmsg;
4095 struct socket *sock;
4099 sock = sock_from_file(req->file, &ret);
4100 if (unlikely(!sock))
4104 kmsg = &req->io->msg;
4105 kmsg->msg.msg_name = &req->io->msg.addr;
4106 /* if iov is set, it's allocated already */
4108 kmsg->iov = kmsg->fast_iov;
4109 kmsg->msg.msg_iter.iov = kmsg->iov;
4111 ret = io_sendmsg_copy_hdr(req, &iomsg);
4117 flags = req->sr_msg.msg_flags;
4118 if (flags & MSG_DONTWAIT)
4119 req->flags |= REQ_F_NOWAIT;
4120 else if (force_nonblock)
4121 flags |= MSG_DONTWAIT;
4123 ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
4124 if (force_nonblock && ret == -EAGAIN)
4125 return io_setup_async_msg(req, kmsg);
4126 if (ret == -ERESTARTSYS)
4129 if (kmsg->iov != kmsg->fast_iov)
4131 req->flags &= ~REQ_F_NEED_CLEANUP;
4133 req_set_fail_links(req);
4134 __io_req_complete(req, ret, 0, cs);
4138 static int io_send(struct io_kiocb *req, bool force_nonblock,
4139 struct io_comp_state *cs)
4141 struct io_sr_msg *sr = &req->sr_msg;
4144 struct socket *sock;
4148 sock = sock_from_file(req->file, &ret);
4149 if (unlikely(!sock))
4152 ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
4156 msg.msg_name = NULL;
4157 msg.msg_control = NULL;
4158 msg.msg_controllen = 0;
4159 msg.msg_namelen = 0;
4161 flags = req->sr_msg.msg_flags;
4162 if (flags & MSG_DONTWAIT)
4163 req->flags |= REQ_F_NOWAIT;
4164 else if (force_nonblock)
4165 flags |= MSG_DONTWAIT;
4167 msg.msg_flags = flags;
4168 ret = sock_sendmsg(sock, &msg);
4169 if (force_nonblock && ret == -EAGAIN)
4171 if (ret == -ERESTARTSYS)
4175 req_set_fail_links(req);
4176 __io_req_complete(req, ret, 0, cs);
4180 static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
4181 struct io_async_msghdr *iomsg)
4183 struct io_sr_msg *sr = &req->sr_msg;
4184 struct iovec __user *uiov;
4188 ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg,
4189 &iomsg->uaddr, &uiov, &iov_len);
4193 if (req->flags & REQ_F_BUFFER_SELECT) {
4196 if (copy_from_user(iomsg->iov, uiov, sizeof(*uiov)))
4198 sr->len = iomsg->iov[0].iov_len;
4199 iov_iter_init(&iomsg->msg.msg_iter, READ, iomsg->iov, 1,
4203 ret = import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
4204 &iomsg->iov, &iomsg->msg.msg_iter);
4212 #ifdef CONFIG_COMPAT
4213 static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
4214 struct io_async_msghdr *iomsg)
4216 struct compat_msghdr __user *msg_compat;
4217 struct io_sr_msg *sr = &req->sr_msg;
4218 struct compat_iovec __user *uiov;
4223 msg_compat = (struct compat_msghdr __user *) sr->umsg;
4224 ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr,
4229 uiov = compat_ptr(ptr);
4230 if (req->flags & REQ_F_BUFFER_SELECT) {
4231 compat_ssize_t clen;
4235 if (!access_ok(uiov, sizeof(*uiov)))
4237 if (__get_user(clen, &uiov->iov_len))
4241 sr->len = iomsg->iov[0].iov_len;
4244 ret = compat_import_iovec(READ, uiov, len, UIO_FASTIOV,
4246 &iomsg->msg.msg_iter);
4255 static int io_recvmsg_copy_hdr(struct io_kiocb *req,
4256 struct io_async_msghdr *iomsg)
4258 iomsg->msg.msg_name = &iomsg->addr;
4259 iomsg->iov = iomsg->fast_iov;
4261 #ifdef CONFIG_COMPAT
4262 if (req->ctx->compat)
4263 return __io_compat_recvmsg_copy_hdr(req, iomsg);
4266 return __io_recvmsg_copy_hdr(req, iomsg);
4269 static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
4272 struct io_sr_msg *sr = &req->sr_msg;
4273 struct io_buffer *kbuf;
4275 kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
4280 req->flags |= REQ_F_BUFFER_SELECTED;
4284 static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req)
4286 return io_put_kbuf(req, req->sr_msg.kbuf);
4289 static int io_recvmsg_prep(struct io_kiocb *req,
4290 const struct io_uring_sqe *sqe)
4292 struct io_sr_msg *sr = &req->sr_msg;
4293 struct io_async_ctx *io = req->io;
4296 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
4299 sr->msg_flags = READ_ONCE(sqe->msg_flags);
4300 sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
4301 sr->len = READ_ONCE(sqe->len);
4302 sr->bgid = READ_ONCE(sqe->buf_group);
4304 #ifdef CONFIG_COMPAT
4305 if (req->ctx->compat)
4306 sr->msg_flags |= MSG_CMSG_COMPAT;
4309 if (!io || req->opcode == IORING_OP_RECV)
4311 /* iovec is already imported */
4312 if (req->flags & REQ_F_NEED_CLEANUP)
4315 ret = io_recvmsg_copy_hdr(req, &io->msg);
4317 req->flags |= REQ_F_NEED_CLEANUP;
4321 static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
4322 struct io_comp_state *cs)
4324 struct io_async_msghdr iomsg, *kmsg;
4325 struct socket *sock;
4326 struct io_buffer *kbuf;
4328 int ret, cflags = 0;
4330 sock = sock_from_file(req->file, &ret);
4331 if (unlikely(!sock))
4335 kmsg = &req->io->msg;
4336 kmsg->msg.msg_name = &req->io->msg.addr;
4337 /* if iov is set, it's allocated already */
4339 kmsg->iov = kmsg->fast_iov;
4340 kmsg->msg.msg_iter.iov = kmsg->iov;
4342 ret = io_recvmsg_copy_hdr(req, &iomsg);
4348 if (req->flags & REQ_F_BUFFER_SELECT) {
4349 kbuf = io_recv_buffer_select(req, !force_nonblock);
4351 return PTR_ERR(kbuf);
4352 kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
4353 iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov,
4354 1, req->sr_msg.len);
4357 flags = req->sr_msg.msg_flags;
4358 if (flags & MSG_DONTWAIT)
4359 req->flags |= REQ_F_NOWAIT;
4360 else if (force_nonblock)
4361 flags |= MSG_DONTWAIT;
4363 ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
4364 kmsg->uaddr, flags);
4365 if (force_nonblock && ret == -EAGAIN)
4366 return io_setup_async_msg(req, kmsg);
4367 if (ret == -ERESTARTSYS)
4370 if (req->flags & REQ_F_BUFFER_SELECTED)
4371 cflags = io_put_recv_kbuf(req);
4372 if (kmsg->iov != kmsg->fast_iov)
4374 req->flags &= ~REQ_F_NEED_CLEANUP;
4376 req_set_fail_links(req);
4377 __io_req_complete(req, ret, cflags, cs);
4381 static int io_recv(struct io_kiocb *req, bool force_nonblock,
4382 struct io_comp_state *cs)
4384 struct io_buffer *kbuf;
4385 struct io_sr_msg *sr = &req->sr_msg;
4387 void __user *buf = sr->buf;
4388 struct socket *sock;
4391 int ret, cflags = 0;
4393 sock = sock_from_file(req->file, &ret);
4394 if (unlikely(!sock))
4397 if (req->flags & REQ_F_BUFFER_SELECT) {
4398 kbuf = io_recv_buffer_select(req, !force_nonblock);
4400 return PTR_ERR(kbuf);
4401 buf = u64_to_user_ptr(kbuf->addr);
4404 ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter);
4408 msg.msg_name = NULL;
4409 msg.msg_control = NULL;
4410 msg.msg_controllen = 0;
4411 msg.msg_namelen = 0;
4412 msg.msg_iocb = NULL;
4415 flags = req->sr_msg.msg_flags;
4416 if (flags & MSG_DONTWAIT)
4417 req->flags |= REQ_F_NOWAIT;
4418 else if (force_nonblock)
4419 flags |= MSG_DONTWAIT;
4421 ret = sock_recvmsg(sock, &msg, flags);
4422 if (force_nonblock && ret == -EAGAIN)
4424 if (ret == -ERESTARTSYS)
4427 if (req->flags & REQ_F_BUFFER_SELECTED)
4428 cflags = io_put_recv_kbuf(req);
4430 req_set_fail_links(req);
4431 __io_req_complete(req, ret, cflags, cs);
4435 static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4437 struct io_accept *accept = &req->accept;
4439 if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
4441 if (sqe->ioprio || sqe->len || sqe->buf_index)
4444 accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
4445 accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
4446 accept->flags = READ_ONCE(sqe->accept_flags);
4447 accept->nofile = rlimit(RLIMIT_NOFILE);
4451 static int io_accept(struct io_kiocb *req, bool force_nonblock,
4452 struct io_comp_state *cs)
4454 struct io_accept *accept = &req->accept;
4455 unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
4458 if (req->file->f_flags & O_NONBLOCK)
4459 req->flags |= REQ_F_NOWAIT;
4461 ret = __sys_accept4_file(req->file, file_flags, accept->addr,
4462 accept->addr_len, accept->flags,
4464 if (ret == -EAGAIN && force_nonblock)
4467 if (ret == -ERESTARTSYS)
4469 req_set_fail_links(req);
4471 __io_req_complete(req, ret, 0, cs);
4475 static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4477 struct io_connect *conn = &req->connect;
4478 struct io_async_ctx *io = req->io;
4480 if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
4482 if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags)
4485 conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
4486 conn->addr_len = READ_ONCE(sqe->addr2);
4491 return move_addr_to_kernel(conn->addr, conn->addr_len,
4492 &io->connect.address);
4495 static int io_connect(struct io_kiocb *req, bool force_nonblock,
4496 struct io_comp_state *cs)
4498 struct io_async_ctx __io, *io;
4499 unsigned file_flags;
4505 ret = move_addr_to_kernel(req->connect.addr,
4506 req->connect.addr_len,
4507 &__io.connect.address);
4513 file_flags = force_nonblock ? O_NONBLOCK : 0;
4515 ret = __sys_connect_file(req->file, &io->connect.address,
4516 req->connect.addr_len, file_flags);
4517 if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
4520 if (io_alloc_async_ctx(req)) {
4524 memcpy(&req->io->connect, &__io.connect, sizeof(__io.connect));
4527 if (ret == -ERESTARTSYS)
4531 req_set_fail_links(req);
4532 __io_req_complete(req, ret, 0, cs);
4535 #else /* !CONFIG_NET */
4536 static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4541 static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
4542 struct io_comp_state *cs)
4547 static int io_send(struct io_kiocb *req, bool force_nonblock,
4548 struct io_comp_state *cs)
4553 static int io_recvmsg_prep(struct io_kiocb *req,
4554 const struct io_uring_sqe *sqe)
4559 static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
4560 struct io_comp_state *cs)
4565 static int io_recv(struct io_kiocb *req, bool force_nonblock,
4566 struct io_comp_state *cs)
4571 static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4576 static int io_accept(struct io_kiocb *req, bool force_nonblock,
4577 struct io_comp_state *cs)
4582 static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
4587 static int io_connect(struct io_kiocb *req, bool force_nonblock,
4588 struct io_comp_state *cs)
4592 #endif /* CONFIG_NET */
4594 struct io_poll_table {
4595 struct poll_table_struct pt;
4596 struct io_kiocb *req;
4600 static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
4601 __poll_t mask, task_work_func_t func)
4605 /* for instances that support it check for an event match first: */
4606 if (mask && !(mask & poll->events))
4609 trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
4611 list_del_init(&poll->wait.entry);
4614 init_task_work(&req->task_work, func);
4615 percpu_ref_get(&req->ctx->refs);
4618 * If this fails, then the task is exiting. When a task exits, the
4619 * work gets canceled, so just cancel this request as well instead
4620 * of executing it. We can't safely execute it anyway, as we may not
4621 * have the needed state needed for it anyway.
4623 ret = io_req_task_work_add(req, &req->task_work);
4624 if (unlikely(ret)) {
4625 struct task_struct *tsk;
4627 WRITE_ONCE(poll->canceled, true);
4628 tsk = io_wq_get_task(req->ctx->io_wq);
4629 task_work_add(tsk, &req->task_work, 0);
4630 wake_up_process(tsk);
4635 static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll)
4636 __acquires(&req->ctx->completion_lock)
4638 struct io_ring_ctx *ctx = req->ctx;
4640 if (!req->result && !READ_ONCE(poll->canceled)) {
4641 struct poll_table_struct pt = { ._key = poll->events };
4643 req->result = vfs_poll(req->file, &pt) & poll->events;
4646 spin_lock_irq(&ctx->completion_lock);
4647 if (!req->result && !READ_ONCE(poll->canceled)) {
4648 add_wait_queue(poll->head, &poll->wait);
4655 static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req)
4657 /* pure poll stashes this in ->io, poll driven retry elsewhere */
4658 if (req->opcode == IORING_OP_POLL_ADD)
4659 return (struct io_poll_iocb *) req->io;
4660 return req->apoll->double_poll;
4663 static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req)
4665 if (req->opcode == IORING_OP_POLL_ADD)
4667 return &req->apoll->poll;
4670 static void io_poll_remove_double(struct io_kiocb *req)
4672 struct io_poll_iocb *poll = io_poll_get_double(req);
4674 lockdep_assert_held(&req->ctx->completion_lock);
4676 if (poll && poll->head) {
4677 struct wait_queue_head *head = poll->head;
4679 spin_lock(&head->lock);
4680 list_del_init(&poll->wait.entry);
4681 if (poll->wait.private)
4682 refcount_dec(&req->refs);
4684 spin_unlock(&head->lock);
4688 static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error)
4690 struct io_ring_ctx *ctx = req->ctx;
4692 io_poll_remove_double(req);
4693 req->poll.done = true;
4694 io_cqring_fill_event(req, error ? error : mangle_poll(mask));
4695 io_commit_cqring(ctx);
4698 static void io_poll_task_handler(struct io_kiocb *req, struct io_kiocb **nxt)
4700 struct io_ring_ctx *ctx = req->ctx;
4702 if (io_poll_rewait(req, &req->poll)) {
4703 spin_unlock_irq(&ctx->completion_lock);
4707 hash_del(&req->hash_node);
4708 io_poll_complete(req, req->result, 0);
4709 req->flags |= REQ_F_COMP_LOCKED;
4710 *nxt = io_put_req_find_next(req);
4711 spin_unlock_irq(&ctx->completion_lock);
4713 io_cqring_ev_posted(ctx);
4716 static void io_poll_task_func(struct callback_head *cb)
4718 struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
4719 struct io_ring_ctx *ctx = req->ctx;
4720 struct io_kiocb *nxt = NULL;
4722 io_poll_task_handler(req, &nxt);
4724 __io_req_task_submit(nxt);
4725 percpu_ref_put(&ctx->refs);
4728 static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode,
4729 int sync, void *key)
4731 struct io_kiocb *req = wait->private;
4732 struct io_poll_iocb *poll = io_poll_get_single(req);
4733 __poll_t mask = key_to_poll(key);
4735 /* for instances that support it check for an event match first: */
4736 if (mask && !(mask & poll->events))
4739 if (poll && poll->head) {
4742 spin_lock(&poll->head->lock);
4743 done = list_empty(&poll->wait.entry);
4745 list_del_init(&poll->wait.entry);
4746 /* make sure double remove sees this as being gone */
4747 wait->private = NULL;
4748 spin_unlock(&poll->head->lock);
4750 __io_async_wake(req, poll, mask, io_poll_task_func);
4752 refcount_dec(&req->refs);
4756 static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events,
4757 wait_queue_func_t wake_func)
4761 poll->canceled = false;
4762 poll->events = events;
4763 INIT_LIST_HEAD(&poll->wait.entry);
4764 init_waitqueue_func_entry(&poll->wait, wake_func);
4767 static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
4768 struct wait_queue_head *head,
4769 struct io_poll_iocb **poll_ptr)
4771 struct io_kiocb *req = pt->req;
4774 * If poll->head is already set, it's because the file being polled
4775 * uses multiple waitqueues for poll handling (eg one for read, one
4776 * for write). Setup a separate io_poll_iocb if this happens.
4778 if (unlikely(poll->head)) {
4779 /* already have a 2nd entry, fail a third attempt */
4781 pt->error = -EINVAL;
4784 poll = kmalloc(sizeof(*poll), GFP_ATOMIC);
4786 pt->error = -ENOMEM;
4789 io_init_poll_iocb(poll, req->poll.events, io_poll_double_wake);
4790 refcount_inc(&req->refs);
4791 poll->wait.private = req;
4798 if (poll->events & EPOLLEXCLUSIVE)
4799 add_wait_queue_exclusive(head, &poll->wait);
4801 add_wait_queue(head, &poll->wait);
4804 static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
4805 struct poll_table_struct *p)
4807 struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
4808 struct async_poll *apoll = pt->req->apoll;
4810 __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);
4813 static void io_async_task_func(struct callback_head *cb)
4815 struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
4816 struct async_poll *apoll = req->apoll;
4817 struct io_ring_ctx *ctx = req->ctx;
4819 trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);
4821 if (io_poll_rewait(req, &apoll->poll)) {
4822 spin_unlock_irq(&ctx->completion_lock);
4823 percpu_ref_put(&ctx->refs);
4827 /* If req is still hashed, it cannot have been canceled. Don't check. */
4828 if (hash_hashed(&req->hash_node))
4829 hash_del(&req->hash_node);
4831 io_poll_remove_double(req);
4832 spin_unlock_irq(&ctx->completion_lock);
4834 if (!READ_ONCE(apoll->poll.canceled))
4835 __io_req_task_submit(req);
4837 __io_req_task_cancel(req, -ECANCELED);
4839 percpu_ref_put(&ctx->refs);
4840 kfree(apoll->double_poll);
4844 static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
4847 struct io_kiocb *req = wait->private;
4848 struct io_poll_iocb *poll = &req->apoll->poll;
4850 trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data,
4853 return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func);
4856 static void io_poll_req_insert(struct io_kiocb *req)
4858 struct io_ring_ctx *ctx = req->ctx;
4859 struct hlist_head *list;
4861 list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
4862 hlist_add_head(&req->hash_node, list);
4865 static __poll_t __io_arm_poll_handler(struct io_kiocb *req,
4866 struct io_poll_iocb *poll,
4867 struct io_poll_table *ipt, __poll_t mask,
4868 wait_queue_func_t wake_func)
4869 __acquires(&ctx->completion_lock)
4871 struct io_ring_ctx *ctx = req->ctx;
4872 bool cancel = false;
4874 io_init_poll_iocb(poll, mask, wake_func);
4875 poll->file = req->file;
4876 poll->wait.private = req;
4878 ipt->pt._key = mask;
4880 ipt->error = -EINVAL;
4882 mask = vfs_poll(req->file, &ipt->pt) & poll->events;
4884 spin_lock_irq(&ctx->completion_lock);
4885 if (likely(poll->head)) {
4886 spin_lock(&poll->head->lock);
4887 if (unlikely(list_empty(&poll->wait.entry))) {
4893 if (mask || ipt->error)
4894 list_del_init(&poll->wait.entry);
4896 WRITE_ONCE(poll->canceled, true);
4897 else if (!poll->done) /* actually waiting for an event */
4898 io_poll_req_insert(req);
4899 spin_unlock(&poll->head->lock);
4905 static bool io_arm_poll_handler(struct io_kiocb *req)
4907 const struct io_op_def *def = &io_op_defs[req->opcode];
4908 struct io_ring_ctx *ctx = req->ctx;
4909 struct async_poll *apoll;
4910 struct io_poll_table ipt;
4913 if (!req->file || !file_can_poll(req->file))
4915 if (req->flags & REQ_F_POLLED)
4917 if (!def->pollin && !def->pollout)
4920 apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
4921 if (unlikely(!apoll))
4923 apoll->double_poll = NULL;
4925 req->flags |= REQ_F_POLLED;
4926 io_get_req_task(req);
4928 INIT_HLIST_NODE(&req->hash_node);
4932 mask |= POLLIN | POLLRDNORM;
4934 mask |= POLLOUT | POLLWRNORM;
4935 mask |= POLLERR | POLLPRI;
4937 ipt.pt._qproc = io_async_queue_proc;
4939 ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask,
4941 if (ret || ipt.error) {
4942 io_poll_remove_double(req);
4943 spin_unlock_irq(&ctx->completion_lock);
4944 kfree(apoll->double_poll);
4948 spin_unlock_irq(&ctx->completion_lock);
4949 trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask,
4950 apoll->poll.events);
4954 static bool __io_poll_remove_one(struct io_kiocb *req,
4955 struct io_poll_iocb *poll)
4957 bool do_complete = false;
4959 spin_lock(&poll->head->lock);
4960 WRITE_ONCE(poll->canceled, true);
4961 if (!list_empty(&poll->wait.entry)) {
4962 list_del_init(&poll->wait.entry);
4965 spin_unlock(&poll->head->lock);
4966 hash_del(&req->hash_node);
4970 static bool io_poll_remove_one(struct io_kiocb *req)
4974 io_poll_remove_double(req);
4976 if (req->opcode == IORING_OP_POLL_ADD) {
4977 do_complete = __io_poll_remove_one(req, &req->poll);
4979 struct async_poll *apoll = req->apoll;
4981 /* non-poll requests have submit ref still */
4982 do_complete = __io_poll_remove_one(req, &apoll->poll);
4985 kfree(apoll->double_poll);
4991 io_cqring_fill_event(req, -ECANCELED);
4992 io_commit_cqring(req->ctx);
4993 req->flags |= REQ_F_COMP_LOCKED;
4994 req_set_fail_links(req);
5001 static void io_poll_remove_all(struct io_ring_ctx *ctx)
5003 struct hlist_node *tmp;
5004 struct io_kiocb *req;
5007 spin_lock_irq(&ctx->completion_lock);
5008 for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
5009 struct hlist_head *list;
5011 list = &ctx->cancel_hash[i];
5012 hlist_for_each_entry_safe(req, tmp, list, hash_node)
5013 posted += io_poll_remove_one(req);
5015 spin_unlock_irq(&ctx->completion_lock);
5018 io_cqring_ev_posted(ctx);
5021 static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
5023 struct hlist_head *list;
5024 struct io_kiocb *req;
5026 list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
5027 hlist_for_each_entry(req, list, hash_node) {
5028 if (sqe_addr != req->user_data)
5030 if (io_poll_remove_one(req))
5038 static int io_poll_remove_prep(struct io_kiocb *req,
5039 const struct io_uring_sqe *sqe)
5041 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
5043 if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
5047 req->poll.addr = READ_ONCE(sqe->addr);
5052 * Find a running poll command that matches one specified in sqe->addr,
5053 * and remove it if found.
5055 static int io_poll_remove(struct io_kiocb *req)
5057 struct io_ring_ctx *ctx = req->ctx;
5061 addr = req->poll.addr;
5062 spin_lock_irq(&ctx->completion_lock);
5063 ret = io_poll_cancel(ctx, addr);
5064 spin_unlock_irq(&ctx->completion_lock);
5067 req_set_fail_links(req);
5068 io_req_complete(req, ret);
5072 static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
5075 struct io_kiocb *req = wait->private;
5076 struct io_poll_iocb *poll = &req->poll;
5078 return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func);
5081 static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
5082 struct poll_table_struct *p)
5084 struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
5086 __io_queue_proc(&pt->req->poll, pt, head, (struct io_poll_iocb **) &pt->req->io);
5089 static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
5091 struct io_poll_iocb *poll = &req->poll;
5094 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
5096 if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
5101 events = READ_ONCE(sqe->poll32_events);
5103 events = swahw32(events);
5105 poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP |
5106 (events & EPOLLEXCLUSIVE);
5108 io_get_req_task(req);
5112 static int io_poll_add(struct io_kiocb *req)
5114 struct io_poll_iocb *poll = &req->poll;
5115 struct io_ring_ctx *ctx = req->ctx;
5116 struct io_poll_table ipt;
5119 INIT_HLIST_NODE(&req->hash_node);
5120 ipt.pt._qproc = io_poll_queue_proc;
5122 mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events,
5125 if (mask) { /* no async, we'd stolen it */
5127 io_poll_complete(req, mask, 0);
5129 spin_unlock_irq(&ctx->completion_lock);
5132 io_cqring_ev_posted(ctx);
5138 static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
5140 struct io_timeout_data *data = container_of(timer,
5141 struct io_timeout_data, timer);
5142 struct io_kiocb *req = data->req;
5143 struct io_ring_ctx *ctx = req->ctx;
5144 unsigned long flags;
5146 spin_lock_irqsave(&ctx->completion_lock, flags);
5147 atomic_set(&req->ctx->cq_timeouts,
5148 atomic_read(&req->ctx->cq_timeouts) + 1);
5151 * We could be racing with timeout deletion. If the list is empty,
5152 * then timeout lookup already found it and will be handling it.
5154 if (!list_empty(&req->timeout.list))
5155 list_del_init(&req->timeout.list);
5157 io_cqring_fill_event(req, -ETIME);
5158 io_commit_cqring(ctx);
5159 spin_unlock_irqrestore(&ctx->completion_lock, flags);
5161 io_cqring_ev_posted(ctx);
5162 req_set_fail_links(req);
5164 return HRTIMER_NORESTART;
5167 static int __io_timeout_cancel(struct io_kiocb *req)
5171 list_del_init(&req->timeout.list);
5173 ret = hrtimer_try_to_cancel(&req->io->timeout.timer);
5177 req_set_fail_links(req);
5178 req->flags |= REQ_F_COMP_LOCKED;
5179 io_cqring_fill_event(req, -ECANCELED);
5184 static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
5186 struct io_kiocb *req;
5189 list_for_each_entry(req, &ctx->timeout_list, timeout.list) {
5190 if (user_data == req->user_data) {
5199 return __io_timeout_cancel(req);
5202 static int io_timeout_remove_prep(struct io_kiocb *req,
5203 const struct io_uring_sqe *sqe)
5205 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
5207 if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
5209 if (sqe->ioprio || sqe->buf_index || sqe->len)
5212 req->timeout.addr = READ_ONCE(sqe->addr);
5213 req->timeout.flags = READ_ONCE(sqe->timeout_flags);
5214 if (req->timeout.flags)
5221 * Remove or update an existing timeout command
5223 static int io_timeout_remove(struct io_kiocb *req)
5225 struct io_ring_ctx *ctx = req->ctx;
5228 spin_lock_irq(&ctx->completion_lock);
5229 ret = io_timeout_cancel(ctx, req->timeout.addr);
5231 io_cqring_fill_event(req, ret);
5232 io_commit_cqring(ctx);
5233 spin_unlock_irq(&ctx->completion_lock);
5234 io_cqring_ev_posted(ctx);
5236 req_set_fail_links(req);
5241 static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
5242 bool is_timeout_link)
5244 struct io_timeout_data *data;
5246 u32 off = READ_ONCE(sqe->off);
5248 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
5250 if (sqe->ioprio || sqe->buf_index || sqe->len != 1)
5252 if (off && is_timeout_link)
5254 flags = READ_ONCE(sqe->timeout_flags);
5255 if (flags & ~IORING_TIMEOUT_ABS)
5258 req->timeout.off = off;
5260 if (!req->io && io_alloc_async_ctx(req))
5263 data = &req->io->timeout;
5266 if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
5269 if (flags & IORING_TIMEOUT_ABS)
5270 data->mode = HRTIMER_MODE_ABS;
5272 data->mode = HRTIMER_MODE_REL;
5274 hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode);
5278 static int io_timeout(struct io_kiocb *req)
5280 struct io_ring_ctx *ctx = req->ctx;
5281 struct io_timeout_data *data = &req->io->timeout;
5282 struct list_head *entry;
5283 u32 tail, off = req->timeout.off;
5285 spin_lock_irq(&ctx->completion_lock);
5288 * sqe->off holds how many events that need to occur for this
5289 * timeout event to be satisfied. If it isn't set, then this is
5290 * a pure timeout request, sequence isn't used.
5292 if (io_is_timeout_noseq(req)) {
5293 entry = ctx->timeout_list.prev;
5297 tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
5298 req->timeout.target_seq = tail + off;
5301 * Insertion sort, ensuring the first entry in the list is always
5302 * the one we need first.
5304 list_for_each_prev(entry, &ctx->timeout_list) {
5305 struct io_kiocb *nxt = list_entry(entry, struct io_kiocb,
5308 if (io_is_timeout_noseq(nxt))
5310 /* nxt.seq is behind @tail, otherwise would've been completed */
5311 if (off >= nxt->timeout.target_seq - tail)
5315 list_add(&req->timeout.list, entry);
5316 data->timer.function = io_timeout_fn;
5317 hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
5318 spin_unlock_irq(&ctx->completion_lock);
5322 static bool io_cancel_cb(struct io_wq_work *work, void *data)
5324 struct io_kiocb *req = container_of(work, struct io_kiocb, work);
5326 return req->user_data == (unsigned long) data;
5329 static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr)
5331 enum io_wq_cancel cancel_ret;
5334 cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr, false);
5335 switch (cancel_ret) {
5336 case IO_WQ_CANCEL_OK:
5339 case IO_WQ_CANCEL_RUNNING:
5342 case IO_WQ_CANCEL_NOTFOUND:
5350 static void io_async_find_and_cancel(struct io_ring_ctx *ctx,
5351 struct io_kiocb *req, __u64 sqe_addr,
5354 unsigned long flags;
5357 ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr);
5358 if (ret != -ENOENT) {
5359 spin_lock_irqsave(&ctx->completion_lock, flags);
5363 spin_lock_irqsave(&ctx->completion_lock, flags);
5364 ret = io_timeout_cancel(ctx, sqe_addr);
5367 ret = io_poll_cancel(ctx, sqe_addr);
5371 io_cqring_fill_event(req, ret);
5372 io_commit_cqring(ctx);
5373 spin_unlock_irqrestore(&ctx->completion_lock, flags);
5374 io_cqring_ev_posted(ctx);
5377 req_set_fail_links(req);
5381 static int io_async_cancel_prep(struct io_kiocb *req,
5382 const struct io_uring_sqe *sqe)
5384 if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
5386 if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
5388 if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags)
5391 req->cancel.addr = READ_ONCE(sqe->addr);
5395 static int io_async_cancel(struct io_kiocb *req)
5397 struct io_ring_ctx *ctx = req->ctx;
5399 io_async_find_and_cancel(ctx, req, req->cancel.addr, 0);
5403 static int io_files_update_prep(struct io_kiocb *req,
5404 const struct io_uring_sqe *sqe)
5406 if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
5408 if (sqe->ioprio || sqe->rw_flags)
5411 req->files_update.offset = READ_ONCE(sqe->off);
5412 req->files_update.nr_args = READ_ONCE(sqe->len);
5413 if (!req->files_update.nr_args)
5415 req->files_update.arg = READ_ONCE(sqe->addr);
5419 static int io_files_update(struct io_kiocb *req, bool force_nonblock,
5420 struct io_comp_state *cs)
5422 struct io_ring_ctx *ctx = req->ctx;
5423 struct io_uring_files_update up;
5429 up.offset = req->files_update.offset;
5430 up.fds = req->files_update.arg;
5432 mutex_lock(&ctx->uring_lock);
5433 ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args);
5434 mutex_unlock(&ctx->uring_lock);
5437 req_set_fail_links(req);
5438 __io_req_complete(req, ret, 0, cs);
5442 static int io_req_defer_prep(struct io_kiocb *req,
5443 const struct io_uring_sqe *sqe)
5450 if (io_alloc_async_ctx(req))
5452 ret = io_prep_work_files(req);
5456 switch (req->opcode) {
5459 case IORING_OP_READV:
5460 case IORING_OP_READ_FIXED:
5461 case IORING_OP_READ:
5462 ret = io_read_prep(req, sqe, true);
5464 case IORING_OP_WRITEV:
5465 case IORING_OP_WRITE_FIXED:
5466 case IORING_OP_WRITE:
5467 ret = io_write_prep(req, sqe, true);
5469 case IORING_OP_POLL_ADD:
5470 ret = io_poll_add_prep(req, sqe);
5472 case IORING_OP_POLL_REMOVE:
5473 ret = io_poll_remove_prep(req, sqe);
5475 case IORING_OP_FSYNC:
5476 ret = io_prep_fsync(req, sqe);
5478 case IORING_OP_SYNC_FILE_RANGE:
5479 ret = io_prep_sfr(req, sqe);
5481 case IORING_OP_SENDMSG:
5482 case IORING_OP_SEND:
5483 ret = io_sendmsg_prep(req, sqe);
5485 case IORING_OP_RECVMSG:
5486 case IORING_OP_RECV:
5487 ret = io_recvmsg_prep(req, sqe);
5489 case IORING_OP_CONNECT:
5490 ret = io_connect_prep(req, sqe);
5492 case IORING_OP_TIMEOUT:
5493 ret = io_timeout_prep(req, sqe, false);
5495 case IORING_OP_TIMEOUT_REMOVE:
5496 ret = io_timeout_remove_prep(req, sqe);
5498 case IORING_OP_ASYNC_CANCEL:
5499 ret = io_async_cancel_prep(req, sqe);
5501 case IORING_OP_LINK_TIMEOUT:
5502 ret = io_timeout_prep(req, sqe, true);
5504 case IORING_OP_ACCEPT:
5505 ret = io_accept_prep(req, sqe);
5507 case IORING_OP_FALLOCATE:
5508 ret = io_fallocate_prep(req, sqe);
5510 case IORING_OP_OPENAT:
5511 ret = io_openat_prep(req, sqe);
5513 case IORING_OP_CLOSE:
5514 ret = io_close_prep(req, sqe);
5516 case IORING_OP_FILES_UPDATE:
5517 ret = io_files_update_prep(req, sqe);
5519 case IORING_OP_STATX:
5520 ret = io_statx_prep(req, sqe);
5522 case IORING_OP_FADVISE:
5523 ret = io_fadvise_prep(req, sqe);
5525 case IORING_OP_MADVISE:
5526 ret = io_madvise_prep(req, sqe);
5528 case IORING_OP_OPENAT2:
5529 ret = io_openat2_prep(req, sqe);
5531 case IORING_OP_EPOLL_CTL:
5532 ret = io_epoll_ctl_prep(req, sqe);
5534 case IORING_OP_SPLICE:
5535 ret = io_splice_prep(req, sqe);
5537 case IORING_OP_PROVIDE_BUFFERS:
5538 ret = io_provide_buffers_prep(req, sqe);
5540 case IORING_OP_REMOVE_BUFFERS:
5541 ret = io_remove_buffers_prep(req, sqe);
5544 ret = io_tee_prep(req, sqe);
5547 printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
5556 static u32 io_get_sequence(struct io_kiocb *req)
5558 struct io_kiocb *pos;
5559 struct io_ring_ctx *ctx = req->ctx;
5560 u32 total_submitted, nr_reqs = 1;
5562 if (req->flags & REQ_F_LINK_HEAD)
5563 list_for_each_entry(pos, &req->link_list, link_list)
5566 total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped;
5567 return total_submitted - nr_reqs;
5570 static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
5572 struct io_ring_ctx *ctx = req->ctx;
5573 struct io_defer_entry *de;
5577 /* Still need defer if there is pending req in defer list. */
5578 if (likely(list_empty_careful(&ctx->defer_list) &&
5579 !(req->flags & REQ_F_IO_DRAIN)))
5582 seq = io_get_sequence(req);
5583 /* Still a chance to pass the sequence check */
5584 if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
5588 ret = io_req_defer_prep(req, sqe);
5592 io_prep_async_link(req);
5593 de = kmalloc(sizeof(*de), GFP_KERNEL);
5597 spin_lock_irq(&ctx->completion_lock);
5598 if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
5599 spin_unlock_irq(&ctx->completion_lock);
5601 io_queue_async_work(req);
5602 return -EIOCBQUEUED;
5605 trace_io_uring_defer(ctx, req, req->user_data);
5608 list_add_tail(&de->list, &ctx->defer_list);
5609 spin_unlock_irq(&ctx->completion_lock);
5610 return -EIOCBQUEUED;
5613 static void __io_clean_op(struct io_kiocb *req)
5615 struct io_async_ctx *io = req->io;
5617 if (req->flags & REQ_F_BUFFER_SELECTED) {
5618 switch (req->opcode) {
5619 case IORING_OP_READV:
5620 case IORING_OP_READ_FIXED:
5621 case IORING_OP_READ:
5622 kfree((void *)(unsigned long)req->rw.addr);
5624 case IORING_OP_RECVMSG:
5625 case IORING_OP_RECV:
5626 kfree(req->sr_msg.kbuf);
5629 req->flags &= ~REQ_F_BUFFER_SELECTED;
5632 if (req->flags & REQ_F_NEED_CLEANUP) {
5633 switch (req->opcode) {
5634 case IORING_OP_READV:
5635 case IORING_OP_READ_FIXED:
5636 case IORING_OP_READ:
5637 case IORING_OP_WRITEV:
5638 case IORING_OP_WRITE_FIXED:
5639 case IORING_OP_WRITE:
5640 if (io->rw.free_iovec)
5641 kfree(io->rw.free_iovec);
5643 case IORING_OP_RECVMSG:
5644 case IORING_OP_SENDMSG:
5645 if (io->msg.iov != io->msg.fast_iov)
5648 case IORING_OP_SPLICE:
5650 io_put_file(req, req->splice.file_in,
5651 (req->splice.flags & SPLICE_F_FD_IN_FIXED));
5654 req->flags &= ~REQ_F_NEED_CLEANUP;
5658 static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
5659 bool force_nonblock, struct io_comp_state *cs)
5661 struct io_ring_ctx *ctx = req->ctx;
5664 switch (req->opcode) {
5666 ret = io_nop(req, cs);
5668 case IORING_OP_READV:
5669 case IORING_OP_READ_FIXED:
5670 case IORING_OP_READ:
5672 ret = io_read_prep(req, sqe, force_nonblock);
5676 ret = io_read(req, force_nonblock, cs);
5678 case IORING_OP_WRITEV:
5679 case IORING_OP_WRITE_FIXED:
5680 case IORING_OP_WRITE:
5682 ret = io_write_prep(req, sqe, force_nonblock);
5686 ret = io_write(req, force_nonblock, cs);
5688 case IORING_OP_FSYNC:
5690 ret = io_prep_fsync(req, sqe);
5694 ret = io_fsync(req, force_nonblock);
5696 case IORING_OP_POLL_ADD:
5698 ret = io_poll_add_prep(req, sqe);
5702 ret = io_poll_add(req);
5704 case IORING_OP_POLL_REMOVE:
5706 ret = io_poll_remove_prep(req, sqe);
5710 ret = io_poll_remove(req);
5712 case IORING_OP_SYNC_FILE_RANGE:
5714 ret = io_prep_sfr(req, sqe);
5718 ret = io_sync_file_range(req, force_nonblock);
5720 case IORING_OP_SENDMSG:
5721 case IORING_OP_SEND:
5723 ret = io_sendmsg_prep(req, sqe);
5727 if (req->opcode == IORING_OP_SENDMSG)
5728 ret = io_sendmsg(req, force_nonblock, cs);
5730 ret = io_send(req, force_nonblock, cs);
5732 case IORING_OP_RECVMSG:
5733 case IORING_OP_RECV:
5735 ret = io_recvmsg_prep(req, sqe);
5739 if (req->opcode == IORING_OP_RECVMSG)
5740 ret = io_recvmsg(req, force_nonblock, cs);
5742 ret = io_recv(req, force_nonblock, cs);
5744 case IORING_OP_TIMEOUT:
5746 ret = io_timeout_prep(req, sqe, false);
5750 ret = io_timeout(req);
5752 case IORING_OP_TIMEOUT_REMOVE:
5754 ret = io_timeout_remove_prep(req, sqe);
5758 ret = io_timeout_remove(req);
5760 case IORING_OP_ACCEPT:
5762 ret = io_accept_prep(req, sqe);
5766 ret = io_accept(req, force_nonblock, cs);
5768 case IORING_OP_CONNECT:
5770 ret = io_connect_prep(req, sqe);
5774 ret = io_connect(req, force_nonblock, cs);
5776 case IORING_OP_ASYNC_CANCEL:
5778 ret = io_async_cancel_prep(req, sqe);
5782 ret = io_async_cancel(req);
5784 case IORING_OP_FALLOCATE:
5786 ret = io_fallocate_prep(req, sqe);
5790 ret = io_fallocate(req, force_nonblock);
5792 case IORING_OP_OPENAT:
5794 ret = io_openat_prep(req, sqe);
5798 ret = io_openat(req, force_nonblock);
5800 case IORING_OP_CLOSE:
5802 ret = io_close_prep(req, sqe);
5806 ret = io_close(req, force_nonblock, cs);
5808 case IORING_OP_FILES_UPDATE:
5810 ret = io_files_update_prep(req, sqe);
5814 ret = io_files_update(req, force_nonblock, cs);
5816 case IORING_OP_STATX:
5818 ret = io_statx_prep(req, sqe);
5822 ret = io_statx(req, force_nonblock);
5824 case IORING_OP_FADVISE:
5826 ret = io_fadvise_prep(req, sqe);
5830 ret = io_fadvise(req, force_nonblock);
5832 case IORING_OP_MADVISE:
5834 ret = io_madvise_prep(req, sqe);
5838 ret = io_madvise(req, force_nonblock);
5840 case IORING_OP_OPENAT2:
5842 ret = io_openat2_prep(req, sqe);
5846 ret = io_openat2(req, force_nonblock);
5848 case IORING_OP_EPOLL_CTL:
5850 ret = io_epoll_ctl_prep(req, sqe);
5854 ret = io_epoll_ctl(req, force_nonblock, cs);
5856 case IORING_OP_SPLICE:
5858 ret = io_splice_prep(req, sqe);
5862 ret = io_splice(req, force_nonblock);
5864 case IORING_OP_PROVIDE_BUFFERS:
5866 ret = io_provide_buffers_prep(req, sqe);
5870 ret = io_provide_buffers(req, force_nonblock, cs);
5872 case IORING_OP_REMOVE_BUFFERS:
5874 ret = io_remove_buffers_prep(req, sqe);
5878 ret = io_remove_buffers(req, force_nonblock, cs);
5882 ret = io_tee_prep(req, sqe);
5886 ret = io_tee(req, force_nonblock);
5896 /* If the op doesn't have a file, we're not polling for it */
5897 if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) {
5898 const bool in_async = io_wq_current_is_worker();
5900 /* workqueue context doesn't hold uring_lock, grab it now */
5902 mutex_lock(&ctx->uring_lock);
5904 io_iopoll_req_issued(req);
5907 mutex_unlock(&ctx->uring_lock);
5913 static struct io_wq_work *io_wq_submit_work(struct io_wq_work *work)
5915 struct io_kiocb *req = container_of(work, struct io_kiocb, work);
5916 struct io_kiocb *timeout;
5919 timeout = io_prep_linked_timeout(req);
5921 io_queue_linked_timeout(timeout);
5923 /* if NO_CANCEL is set, we must still run the work */
5924 if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
5925 IO_WQ_WORK_CANCEL) {
5931 ret = io_issue_sqe(req, NULL, false, NULL);
5933 * We can get EAGAIN for polled IO even though we're
5934 * forcing a sync submission from here, since we can't
5935 * wait for request slots on the block side.
5944 req_set_fail_links(req);
5945 io_req_complete(req, ret);
5948 return io_steal_work(req);
5951 static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
5954 struct fixed_file_table *table;
5956 table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT];
5957 return table->files[index & IORING_FILE_TABLE_MASK];
5960 static int io_file_get(struct io_submit_state *state, struct io_kiocb *req,
5961 int fd, struct file **out_file, bool fixed)
5963 struct io_ring_ctx *ctx = req->ctx;
5967 if (unlikely(!ctx->file_data ||
5968 (unsigned) fd >= ctx->nr_user_files))
5970 fd = array_index_nospec(fd, ctx->nr_user_files);
5971 file = io_file_from_index(ctx, fd);
5973 req->fixed_file_refs = ctx->file_data->cur_refs;
5974 percpu_ref_get(req->fixed_file_refs);
5977 trace_io_uring_file_get(ctx, fd);
5978 file = __io_file_get(state, fd);
5981 if (file || io_op_defs[req->opcode].needs_file_no_error) {
5988 static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
5993 fixed = (req->flags & REQ_F_FIXED_FILE) != 0;
5994 if (unlikely(!fixed && io_async_submit(req->ctx)))
5997 return io_file_get(state, req, fd, &req->file, fixed);
6000 static int io_grab_files(struct io_kiocb *req)
6003 struct io_ring_ctx *ctx = req->ctx;
6005 io_req_init_async(req);
6007 if (req->work.files || (req->flags & REQ_F_NO_FILE_TABLE))
6009 if (!ctx->ring_file)
6013 spin_lock_irq(&ctx->inflight_lock);
6015 * We use the f_ops->flush() handler to ensure that we can flush
6016 * out work accessing these files if the fd is closed. Check if
6017 * the fd has changed since we started down this path, and disallow
6018 * this operation if it has.
6020 if (fcheck(ctx->ring_fd) == ctx->ring_file) {
6021 list_add(&req->inflight_entry, &ctx->inflight_list);
6022 req->flags |= REQ_F_INFLIGHT;
6023 req->work.files = current->files;
6026 spin_unlock_irq(&ctx->inflight_lock);
6032 static inline int io_prep_work_files(struct io_kiocb *req)
6034 if (!io_op_defs[req->opcode].file_table)
6036 return io_grab_files(req);
6039 static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
6041 struct io_timeout_data *data = container_of(timer,
6042 struct io_timeout_data, timer);
6043 struct io_kiocb *req = data->req;
6044 struct io_ring_ctx *ctx = req->ctx;
6045 struct io_kiocb *prev = NULL;
6046 unsigned long flags;
6048 spin_lock_irqsave(&ctx->completion_lock, flags);
6051 * We don't expect the list to be empty, that will only happen if we
6052 * race with the completion of the linked work.
6054 if (!list_empty(&req->link_list)) {
6055 prev = list_entry(req->link_list.prev, struct io_kiocb,
6057 if (refcount_inc_not_zero(&prev->refs)) {
6058 list_del_init(&req->link_list);
6059 prev->flags &= ~REQ_F_LINK_TIMEOUT;
6064 spin_unlock_irqrestore(&ctx->completion_lock, flags);
6067 req_set_fail_links(prev);
6068 io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME);
6071 io_req_complete(req, -ETIME);
6073 return HRTIMER_NORESTART;
6076 static void __io_queue_linked_timeout(struct io_kiocb *req)
6079 * If the list is now empty, then our linked request finished before
6080 * we got a chance to setup the timer
6082 if (!list_empty(&req->link_list)) {
6083 struct io_timeout_data *data = &req->io->timeout;
6085 data->timer.function = io_link_timeout_fn;
6086 hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
6091 static void io_queue_linked_timeout(struct io_kiocb *req)
6093 struct io_ring_ctx *ctx = req->ctx;
6095 spin_lock_irq(&ctx->completion_lock);
6096 __io_queue_linked_timeout(req);
6097 spin_unlock_irq(&ctx->completion_lock);
6099 /* drop submission reference */
6103 static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
6105 struct io_kiocb *nxt;
6107 if (!(req->flags & REQ_F_LINK_HEAD))
6109 if (req->flags & REQ_F_LINK_TIMEOUT)
6112 nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,
6114 if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT)
6117 req->flags |= REQ_F_LINK_TIMEOUT;
6121 static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
6122 struct io_comp_state *cs)
6124 struct io_kiocb *linked_timeout;
6125 struct io_kiocb *nxt;
6126 const struct cred *old_creds = NULL;
6130 linked_timeout = io_prep_linked_timeout(req);
6132 if ((req->flags & REQ_F_WORK_INITIALIZED) && req->work.creds &&
6133 req->work.creds != current_cred()) {
6135 revert_creds(old_creds);
6136 if (old_creds == req->work.creds)
6137 old_creds = NULL; /* restored original creds */
6139 old_creds = override_creds(req->work.creds);
6142 ret = io_issue_sqe(req, sqe, true, cs);
6145 * We async punt it if the file wasn't marked NOWAIT, or if the file
6146 * doesn't support non-blocking read/write attempts
6148 if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
6149 if (!io_arm_poll_handler(req)) {
6151 ret = io_prep_work_files(req);
6155 * Queued up for async execution, worker will release
6156 * submit reference when the iocb is actually submitted.
6158 io_queue_async_work(req);
6162 io_queue_linked_timeout(linked_timeout);
6166 if (unlikely(ret)) {
6168 /* un-prep timeout, so it'll be killed as any other linked */
6169 req->flags &= ~REQ_F_LINK_TIMEOUT;
6170 req_set_fail_links(req);
6172 io_req_complete(req, ret);
6176 /* drop submission reference */
6177 nxt = io_put_req_find_next(req);
6179 io_queue_linked_timeout(linked_timeout);
6184 if (req->flags & REQ_F_FORCE_ASYNC)
6190 revert_creds(old_creds);
6193 static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
6194 struct io_comp_state *cs)
6198 ret = io_req_defer(req, sqe);
6200 if (ret != -EIOCBQUEUED) {
6202 req_set_fail_links(req);
6204 io_req_complete(req, ret);
6206 } else if (req->flags & REQ_F_FORCE_ASYNC) {
6208 ret = io_req_defer_prep(req, sqe);
6214 * Never try inline submit of IOSQE_ASYNC is set, go straight
6215 * to async execution.
6217 io_req_init_async(req);
6218 req->work.flags |= IO_WQ_WORK_CONCURRENT;
6219 io_queue_async_work(req);
6221 __io_queue_sqe(req, sqe, cs);
6225 static inline void io_queue_link_head(struct io_kiocb *req,
6226 struct io_comp_state *cs)
6228 if (unlikely(req->flags & REQ_F_FAIL_LINK)) {
6230 io_req_complete(req, -ECANCELED);
6232 io_queue_sqe(req, NULL, cs);
6235 static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
6236 struct io_kiocb **link, struct io_comp_state *cs)
6238 struct io_ring_ctx *ctx = req->ctx;
6242 * If we already have a head request, queue this one for async
6243 * submittal once the head completes. If we don't have a head but
6244 * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
6245 * submitted sync once the chain is complete. If none of those
6246 * conditions are true (normal request), then just queue it.
6249 struct io_kiocb *head = *link;
6252 * Taking sequential execution of a link, draining both sides
6253 * of the link also fullfils IOSQE_IO_DRAIN semantics for all
6254 * requests in the link. So, it drains the head and the
6255 * next after the link request. The last one is done via
6256 * drain_next flag to persist the effect across calls.
6258 if (req->flags & REQ_F_IO_DRAIN) {
6259 head->flags |= REQ_F_IO_DRAIN;
6260 ctx->drain_next = 1;
6262 ret = io_req_defer_prep(req, sqe);
6263 if (unlikely(ret)) {
6264 /* fail even hard links since we don't submit */
6265 head->flags |= REQ_F_FAIL_LINK;
6268 trace_io_uring_link(ctx, req, head);
6269 io_get_req_task(req);
6270 list_add_tail(&req->link_list, &head->link_list);
6272 /* last request of a link, enqueue the link */
6273 if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
6274 io_queue_link_head(head, cs);
6278 if (unlikely(ctx->drain_next)) {
6279 req->flags |= REQ_F_IO_DRAIN;
6280 ctx->drain_next = 0;
6282 if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
6283 req->flags |= REQ_F_LINK_HEAD;
6284 INIT_LIST_HEAD(&req->link_list);
6286 ret = io_req_defer_prep(req, sqe);
6288 req->flags |= REQ_F_FAIL_LINK;
6291 io_queue_sqe(req, sqe, cs);
6299 * Batched submission is done, ensure local IO is flushed out.
6301 static void io_submit_state_end(struct io_submit_state *state)
6303 if (!list_empty(&state->comp.list))
6304 io_submit_flush_completions(&state->comp);
6305 blk_finish_plug(&state->plug);
6306 io_state_file_put(state);
6307 if (state->free_reqs)
6308 kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
6312 * Start submission side cache.
6314 static void io_submit_state_start(struct io_submit_state *state,
6315 struct io_ring_ctx *ctx, unsigned int max_ios)
6317 blk_start_plug(&state->plug);
6319 state->plug.nowait = true;
6322 INIT_LIST_HEAD(&state->comp.list);
6323 state->comp.ctx = ctx;
6324 state->free_reqs = 0;
6326 state->ios_left = max_ios;
6329 static void io_commit_sqring(struct io_ring_ctx *ctx)
6331 struct io_rings *rings = ctx->rings;
6334 * Ensure any loads from the SQEs are done at this point,
6335 * since once we write the new head, the application could
6336 * write new data to them.
6338 smp_store_release(&rings->sq.head, ctx->cached_sq_head);
6342 * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory
6343 * that is mapped by userspace. This means that care needs to be taken to
6344 * ensure that reads are stable, as we cannot rely on userspace always
6345 * being a good citizen. If members of the sqe are validated and then later
6346 * used, it's important that those reads are done through READ_ONCE() to
6347 * prevent a re-load down the line.
6349 static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
6351 u32 *sq_array = ctx->sq_array;
6355 * The cached sq head (or cq tail) serves two purposes:
6357 * 1) allows us to batch the cost of updating the user visible
6359 * 2) allows the kernel side to track the head on its own, even
6360 * though the application is the one updating it.
6362 head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]);
6363 if (likely(head < ctx->sq_entries))
6364 return &ctx->sq_sqes[head];
6366 /* drop invalid entries */
6367 ctx->cached_sq_dropped++;
6368 WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped);
6372 static inline void io_consume_sqe(struct io_ring_ctx *ctx)
6374 ctx->cached_sq_head++;
6377 #define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
6378 IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
6379 IOSQE_BUFFER_SELECT)
6381 static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
6382 const struct io_uring_sqe *sqe,
6383 struct io_submit_state *state)
6385 unsigned int sqe_flags;
6388 req->opcode = READ_ONCE(sqe->opcode);
6389 req->user_data = READ_ONCE(sqe->user_data);
6394 /* one is dropped after submission, the other at completion */
6395 refcount_set(&req->refs, 2);
6396 req->task = current;
6399 if (unlikely(req->opcode >= IORING_OP_LAST))
6402 if (unlikely(io_sq_thread_acquire_mm(ctx, req)))
6405 sqe_flags = READ_ONCE(sqe->flags);
6406 /* enforce forwards compatibility on users */
6407 if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
6410 if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
6411 !io_op_defs[req->opcode].buffer_select)
6414 id = READ_ONCE(sqe->personality);
6416 io_req_init_async(req);
6417 req->work.creds = idr_find(&ctx->personality_idr, id);
6418 if (unlikely(!req->work.creds))
6420 get_cred(req->work.creds);
6423 /* same numerical values with corresponding REQ_F_*, safe to copy */
6424 req->flags |= sqe_flags;
6426 if (!io_op_defs[req->opcode].needs_file)
6429 return io_req_set_file(state, req, READ_ONCE(sqe->fd));
6432 static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
6433 struct file *ring_file, int ring_fd)
6435 struct io_submit_state state;
6436 struct io_kiocb *link = NULL;
6437 int i, submitted = 0;
6439 /* if we have a backlog and couldn't flush it all, return BUSY */
6440 if (test_bit(0, &ctx->sq_check_overflow)) {
6441 if (!list_empty(&ctx->cq_overflow_list) &&
6442 !io_cqring_overflow_flush(ctx, false))
6446 /* make sure SQ entry isn't read before tail */
6447 nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
6449 if (!percpu_ref_tryget_many(&ctx->refs, nr))
6452 io_submit_state_start(&state, ctx, nr);
6454 ctx->ring_fd = ring_fd;
6455 ctx->ring_file = ring_file;
6457 for (i = 0; i < nr; i++) {
6458 const struct io_uring_sqe *sqe;
6459 struct io_kiocb *req;
6462 sqe = io_get_sqe(ctx);
6463 if (unlikely(!sqe)) {
6464 io_consume_sqe(ctx);
6467 req = io_alloc_req(ctx, &state);
6468 if (unlikely(!req)) {
6470 submitted = -EAGAIN;
6474 err = io_init_req(ctx, req, sqe, &state);
6475 io_consume_sqe(ctx);
6476 /* will complete beyond this point, count as submitted */
6479 if (unlikely(err)) {
6482 io_req_complete(req, err);
6486 trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data,
6487 true, io_async_submit(ctx));
6488 err = io_submit_sqe(req, sqe, &link, &state.comp);
6493 if (unlikely(submitted != nr)) {
6494 int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
6496 percpu_ref_put_many(&ctx->refs, nr - ref_used);
6499 io_queue_link_head(link, &state.comp);
6500 io_submit_state_end(&state);
6502 /* Commit SQ ring head once we've consumed and submitted all SQEs */
6503 io_commit_sqring(ctx);
6508 static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx)
6510 /* Tell userspace we may need a wakeup call */
6511 spin_lock_irq(&ctx->completion_lock);
6512 ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
6513 spin_unlock_irq(&ctx->completion_lock);
6516 static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx)
6518 spin_lock_irq(&ctx->completion_lock);
6519 ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
6520 spin_unlock_irq(&ctx->completion_lock);
6523 static int io_sq_thread(void *data)
6525 struct io_ring_ctx *ctx = data;
6526 const struct cred *old_cred;
6528 unsigned long timeout;
6531 complete(&ctx->sq_thread_comp);
6533 old_cred = override_creds(ctx->creds);
6535 timeout = jiffies + ctx->sq_thread_idle;
6536 while (!kthread_should_park()) {
6537 unsigned int to_submit;
6539 if (!list_empty(&ctx->iopoll_list)) {
6540 unsigned nr_events = 0;
6542 mutex_lock(&ctx->uring_lock);
6543 if (!list_empty(&ctx->iopoll_list) && !need_resched())
6544 io_do_iopoll(ctx, &nr_events, 0);
6546 timeout = jiffies + ctx->sq_thread_idle;
6547 mutex_unlock(&ctx->uring_lock);
6550 to_submit = io_sqring_entries(ctx);
6553 * If submit got -EBUSY, flag us as needing the application
6554 * to enter the kernel to reap and flush events.
6556 if (!to_submit || ret == -EBUSY || need_resched()) {
6558 * Drop cur_mm before scheduling, we can't hold it for
6559 * long periods (or over schedule()). Do this before
6560 * adding ourselves to the waitqueue, as the unuse/drop
6563 io_sq_thread_drop_mm();
6566 * We're polling. If we're within the defined idle
6567 * period, then let us spin without work before going
6568 * to sleep. The exception is if we got EBUSY doing
6569 * more IO, we should wait for the application to
6570 * reap events and wake us up.
6572 if (!list_empty(&ctx->iopoll_list) || need_resched() ||
6573 (!time_after(jiffies, timeout) && ret != -EBUSY &&
6574 !percpu_ref_is_dying(&ctx->refs))) {
6580 prepare_to_wait(&ctx->sqo_wait, &wait,
6581 TASK_INTERRUPTIBLE);
6584 * While doing polled IO, before going to sleep, we need
6585 * to check if there are new reqs added to iopoll_list,
6586 * it is because reqs may have been punted to io worker
6587 * and will be added to iopoll_list later, hence check
6588 * the iopoll_list again.
6590 if ((ctx->flags & IORING_SETUP_IOPOLL) &&
6591 !list_empty_careful(&ctx->iopoll_list)) {
6592 finish_wait(&ctx->sqo_wait, &wait);
6596 io_ring_set_wakeup_flag(ctx);
6598 to_submit = io_sqring_entries(ctx);
6599 if (!to_submit || ret == -EBUSY) {
6600 if (kthread_should_park()) {
6601 finish_wait(&ctx->sqo_wait, &wait);
6604 if (io_run_task_work()) {
6605 finish_wait(&ctx->sqo_wait, &wait);
6606 io_ring_clear_wakeup_flag(ctx);
6609 if (signal_pending(current))
6610 flush_signals(current);
6612 finish_wait(&ctx->sqo_wait, &wait);
6614 io_ring_clear_wakeup_flag(ctx);
6618 finish_wait(&ctx->sqo_wait, &wait);
6620 io_ring_clear_wakeup_flag(ctx);
6623 mutex_lock(&ctx->uring_lock);
6624 if (likely(!percpu_ref_is_dying(&ctx->refs)))
6625 ret = io_submit_sqes(ctx, to_submit, NULL, -1);
6626 mutex_unlock(&ctx->uring_lock);
6627 timeout = jiffies + ctx->sq_thread_idle;
6632 io_sq_thread_drop_mm();
6633 revert_creds(old_cred);
6640 struct io_wait_queue {
6641 struct wait_queue_entry wq;
6642 struct io_ring_ctx *ctx;
6644 unsigned nr_timeouts;
6647 static inline bool io_should_wake(struct io_wait_queue *iowq, bool noflush)
6649 struct io_ring_ctx *ctx = iowq->ctx;
6652 * Wake up if we have enough events, or if a timeout occurred since we
6653 * started waiting. For timeouts, we always want to return to userspace,
6654 * regardless of event count.
6656 return io_cqring_events(ctx, noflush) >= iowq->to_wait ||
6657 atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
6660 static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
6661 int wake_flags, void *key)
6663 struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
6666 /* use noflush == true, as we can't safely rely on locking context */
6667 if (!io_should_wake(iowq, true))
6670 return autoremove_wake_function(curr, mode, wake_flags, key);
6674 * Wait until events become available, if we don't already have some. The
6675 * application must reap them itself, as they reside on the shared cq ring.
6677 static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
6678 const sigset_t __user *sig, size_t sigsz)
6680 struct io_wait_queue iowq = {
6683 .func = io_wake_function,
6684 .entry = LIST_HEAD_INIT(iowq.wq.entry),
6687 .to_wait = min_events,
6689 struct io_rings *rings = ctx->rings;
6693 if (io_cqring_events(ctx, false) >= min_events)
6695 if (!io_run_task_work())
6700 #ifdef CONFIG_COMPAT
6701 if (in_compat_syscall())
6702 ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
6706 ret = set_user_sigmask(sig, sigsz);
6712 iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
6713 trace_io_uring_cqring_wait(ctx, min_events);
6715 prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
6716 TASK_INTERRUPTIBLE);
6717 /* make sure we run task_work before checking for signals */
6718 if (io_run_task_work())
6720 if (signal_pending(current)) {
6721 if (current->jobctl & JOBCTL_TASK_WORK) {
6722 spin_lock_irq(¤t->sighand->siglock);
6723 current->jobctl &= ~JOBCTL_TASK_WORK;
6724 recalc_sigpending();
6725 spin_unlock_irq(¤t->sighand->siglock);
6731 if (io_should_wake(&iowq, false))
6735 finish_wait(&ctx->wait, &iowq.wq);
6737 restore_saved_sigmask_unless(ret == -EINTR);
6739 return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
6742 static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
6744 #if defined(CONFIG_UNIX)
6745 if (ctx->ring_sock) {
6746 struct sock *sock = ctx->ring_sock->sk;
6747 struct sk_buff *skb;
6749 while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
6755 for (i = 0; i < ctx->nr_user_files; i++) {
6758 file = io_file_from_index(ctx, i);
6765 static void io_file_ref_kill(struct percpu_ref *ref)
6767 struct fixed_file_data *data;
6769 data = container_of(ref, struct fixed_file_data, refs);
6770 complete(&data->done);
6773 static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
6775 struct fixed_file_data *data = ctx->file_data;
6776 struct fixed_file_ref_node *ref_node = NULL;
6777 unsigned nr_tables, i;
6782 spin_lock(&data->lock);
6783 if (!list_empty(&data->ref_list))
6784 ref_node = list_first_entry(&data->ref_list,
6785 struct fixed_file_ref_node, node);
6786 spin_unlock(&data->lock);
6788 percpu_ref_kill(&ref_node->refs);
6790 percpu_ref_kill(&data->refs);
6792 /* wait for all refs nodes to complete */
6793 flush_delayed_work(&ctx->file_put_work);
6794 wait_for_completion(&data->done);
6796 __io_sqe_files_unregister(ctx);
6797 nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
6798 for (i = 0; i < nr_tables; i++)
6799 kfree(data->table[i].files);
6801 percpu_ref_exit(&data->refs);
6803 ctx->file_data = NULL;
6804 ctx->nr_user_files = 0;
6808 static void io_sq_thread_stop(struct io_ring_ctx *ctx)
6810 if (ctx->sqo_thread) {
6811 wait_for_completion(&ctx->sq_thread_comp);
6813 * The park is a bit of a work-around, without it we get
6814 * warning spews on shutdown with SQPOLL set and affinity
6815 * set to a single CPU.
6817 kthread_park(ctx->sqo_thread);
6818 kthread_stop(ctx->sqo_thread);
6819 ctx->sqo_thread = NULL;
6823 static void io_finish_async(struct io_ring_ctx *ctx)
6825 io_sq_thread_stop(ctx);
6828 io_wq_destroy(ctx->io_wq);
6833 #if defined(CONFIG_UNIX)
6835 * Ensure the UNIX gc is aware of our file set, so we are certain that
6836 * the io_uring can be safely unregistered on process exit, even if we have
6837 * loops in the file referencing.
6839 static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
6841 struct sock *sk = ctx->ring_sock->sk;
6842 struct scm_fp_list *fpl;
6843 struct sk_buff *skb;
6846 fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
6850 skb = alloc_skb(0, GFP_KERNEL);
6859 fpl->user = get_uid(ctx->user);
6860 for (i = 0; i < nr; i++) {
6861 struct file *file = io_file_from_index(ctx, i + offset);
6865 fpl->fp[nr_files] = get_file(file);
6866 unix_inflight(fpl->user, fpl->fp[nr_files]);
6871 fpl->max = SCM_MAX_FD;
6872 fpl->count = nr_files;
6873 UNIXCB(skb).fp = fpl;
6874 skb->destructor = unix_destruct_scm;
6875 refcount_add(skb->truesize, &sk->sk_wmem_alloc);
6876 skb_queue_head(&sk->sk_receive_queue, skb);
6878 for (i = 0; i < nr_files; i++)
6889 * If UNIX sockets are enabled, fd passing can cause a reference cycle which
6890 * causes regular reference counting to break down. We rely on the UNIX
6891 * garbage collection to take care of this problem for us.
6893 static int io_sqe_files_scm(struct io_ring_ctx *ctx)
6895 unsigned left, total;
6899 left = ctx->nr_user_files;
6901 unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
6903 ret = __io_sqe_files_scm(ctx, this_files, total);
6907 total += this_files;
6913 while (total < ctx->nr_user_files) {
6914 struct file *file = io_file_from_index(ctx, total);
6924 static int io_sqe_files_scm(struct io_ring_ctx *ctx)
6930 static int io_sqe_alloc_file_tables(struct io_ring_ctx *ctx, unsigned nr_tables,
6935 for (i = 0; i < nr_tables; i++) {
6936 struct fixed_file_table *table = &ctx->file_data->table[i];
6937 unsigned this_files;
6939 this_files = min(nr_files, IORING_MAX_FILES_TABLE);
6940 table->files = kcalloc(this_files, sizeof(struct file *),
6944 nr_files -= this_files;
6950 for (i = 0; i < nr_tables; i++) {
6951 struct fixed_file_table *table = &ctx->file_data->table[i];
6952 kfree(table->files);
6957 static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file)
6959 #if defined(CONFIG_UNIX)
6960 struct sock *sock = ctx->ring_sock->sk;
6961 struct sk_buff_head list, *head = &sock->sk_receive_queue;
6962 struct sk_buff *skb;
6965 __skb_queue_head_init(&list);
6968 * Find the skb that holds this file in its SCM_RIGHTS. When found,
6969 * remove this entry and rearrange the file array.
6971 skb = skb_dequeue(head);
6973 struct scm_fp_list *fp;
6975 fp = UNIXCB(skb).fp;
6976 for (i = 0; i < fp->count; i++) {
6979 if (fp->fp[i] != file)
6982 unix_notinflight(fp->user, fp->fp[i]);
6983 left = fp->count - 1 - i;
6985 memmove(&fp->fp[i], &fp->fp[i + 1],
6986 left * sizeof(struct file *));
6993 __skb_queue_tail(&list, skb);
7003 __skb_queue_tail(&list, skb);
7005 skb = skb_dequeue(head);
7008 if (skb_peek(&list)) {
7009 spin_lock_irq(&head->lock);
7010 while ((skb = __skb_dequeue(&list)) != NULL)
7011 __skb_queue_tail(head, skb);
7012 spin_unlock_irq(&head->lock);
7019 struct io_file_put {
7020 struct list_head list;
7024 static void __io_file_put_work(struct fixed_file_ref_node *ref_node)
7026 struct fixed_file_data *file_data = ref_node->file_data;
7027 struct io_ring_ctx *ctx = file_data->ctx;
7028 struct io_file_put *pfile, *tmp;
7030 list_for_each_entry_safe(pfile, tmp, &ref_node->file_list, list) {
7031 list_del(&pfile->list);
7032 io_ring_file_put(ctx, pfile->file);
7036 spin_lock(&file_data->lock);
7037 list_del(&ref_node->node);
7038 spin_unlock(&file_data->lock);
7040 percpu_ref_exit(&ref_node->refs);
7042 percpu_ref_put(&file_data->refs);
7045 static void io_file_put_work(struct work_struct *work)
7047 struct io_ring_ctx *ctx;
7048 struct llist_node *node;
7050 ctx = container_of(work, struct io_ring_ctx, file_put_work.work);
7051 node = llist_del_all(&ctx->file_put_llist);
7054 struct fixed_file_ref_node *ref_node;
7055 struct llist_node *next = node->next;
7057 ref_node = llist_entry(node, struct fixed_file_ref_node, llist);
7058 __io_file_put_work(ref_node);
7063 static void io_file_data_ref_zero(struct percpu_ref *ref)
7065 struct fixed_file_ref_node *ref_node;
7066 struct io_ring_ctx *ctx;
7070 ref_node = container_of(ref, struct fixed_file_ref_node, refs);
7071 ctx = ref_node->file_data->ctx;
7073 if (percpu_ref_is_dying(&ctx->file_data->refs))
7076 first_add = llist_add(&ref_node->llist, &ctx->file_put_llist);
7078 mod_delayed_work(system_wq, &ctx->file_put_work, 0);
7080 queue_delayed_work(system_wq, &ctx->file_put_work, delay);
7083 static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
7084 struct io_ring_ctx *ctx)
7086 struct fixed_file_ref_node *ref_node;
7088 ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
7090 return ERR_PTR(-ENOMEM);
7092 if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero,
7095 return ERR_PTR(-ENOMEM);
7097 INIT_LIST_HEAD(&ref_node->node);
7098 INIT_LIST_HEAD(&ref_node->file_list);
7099 ref_node->file_data = ctx->file_data;
7103 static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node)
7105 percpu_ref_exit(&ref_node->refs);
7109 static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
7112 __s32 __user *fds = (__s32 __user *) arg;
7117 struct fixed_file_ref_node *ref_node;
7123 if (nr_args > IORING_MAX_FIXED_FILES)
7126 ctx->file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL);
7127 if (!ctx->file_data)
7129 ctx->file_data->ctx = ctx;
7130 init_completion(&ctx->file_data->done);
7131 INIT_LIST_HEAD(&ctx->file_data->ref_list);
7132 spin_lock_init(&ctx->file_data->lock);
7134 nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
7135 ctx->file_data->table = kcalloc(nr_tables,
7136 sizeof(struct fixed_file_table),
7138 if (!ctx->file_data->table) {
7139 kfree(ctx->file_data);
7140 ctx->file_data = NULL;
7144 if (percpu_ref_init(&ctx->file_data->refs, io_file_ref_kill,
7145 PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) {
7146 kfree(ctx->file_data->table);
7147 kfree(ctx->file_data);
7148 ctx->file_data = NULL;
7152 if (io_sqe_alloc_file_tables(ctx, nr_tables, nr_args)) {
7153 percpu_ref_exit(&ctx->file_data->refs);
7154 kfree(ctx->file_data->table);
7155 kfree(ctx->file_data);
7156 ctx->file_data = NULL;
7160 for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
7161 struct fixed_file_table *table;
7165 if (copy_from_user(&fd, &fds[i], sizeof(fd)))
7167 /* allow sparse sets */
7173 table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
7174 index = i & IORING_FILE_TABLE_MASK;
7182 * Don't allow io_uring instances to be registered. If UNIX
7183 * isn't enabled, then this causes a reference cycle and this
7184 * instance can never get freed. If UNIX is enabled we'll
7185 * handle it just fine, but there's still no point in allowing
7186 * a ring fd as it doesn't support regular read/write anyway.
7188 if (file->f_op == &io_uring_fops) {
7193 table->files[index] = file;
7197 for (i = 0; i < ctx->nr_user_files; i++) {
7198 file = io_file_from_index(ctx, i);
7202 for (i = 0; i < nr_tables; i++)
7203 kfree(ctx->file_data->table[i].files);
7205 percpu_ref_exit(&ctx->file_data->refs);
7206 kfree(ctx->file_data->table);
7207 kfree(ctx->file_data);
7208 ctx->file_data = NULL;
7209 ctx->nr_user_files = 0;
7213 ret = io_sqe_files_scm(ctx);
7215 io_sqe_files_unregister(ctx);
7219 ref_node = alloc_fixed_file_ref_node(ctx);
7220 if (IS_ERR(ref_node)) {
7221 io_sqe_files_unregister(ctx);
7222 return PTR_ERR(ref_node);
7225 ctx->file_data->cur_refs = &ref_node->refs;
7226 spin_lock(&ctx->file_data->lock);
7227 list_add(&ref_node->node, &ctx->file_data->ref_list);
7228 spin_unlock(&ctx->file_data->lock);
7229 percpu_ref_get(&ctx->file_data->refs);
7233 static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
7236 #if defined(CONFIG_UNIX)
7237 struct sock *sock = ctx->ring_sock->sk;
7238 struct sk_buff_head *head = &sock->sk_receive_queue;
7239 struct sk_buff *skb;
7242 * See if we can merge this file into an existing skb SCM_RIGHTS
7243 * file set. If there's no room, fall back to allocating a new skb
7244 * and filling it in.
7246 spin_lock_irq(&head->lock);
7247 skb = skb_peek(head);
7249 struct scm_fp_list *fpl = UNIXCB(skb).fp;
7251 if (fpl->count < SCM_MAX_FD) {
7252 __skb_unlink(skb, head);
7253 spin_unlock_irq(&head->lock);
7254 fpl->fp[fpl->count] = get_file(file);
7255 unix_inflight(fpl->user, fpl->fp[fpl->count]);
7257 spin_lock_irq(&head->lock);
7258 __skb_queue_head(head, skb);
7263 spin_unlock_irq(&head->lock);
7270 return __io_sqe_files_scm(ctx, 1, index);
7276 static int io_queue_file_removal(struct fixed_file_data *data,
7279 struct io_file_put *pfile;
7280 struct percpu_ref *refs = data->cur_refs;
7281 struct fixed_file_ref_node *ref_node;
7283 pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
7287 ref_node = container_of(refs, struct fixed_file_ref_node, refs);
7289 list_add(&pfile->list, &ref_node->file_list);
7294 static int __io_sqe_files_update(struct io_ring_ctx *ctx,
7295 struct io_uring_files_update *up,
7298 struct fixed_file_data *data = ctx->file_data;
7299 struct fixed_file_ref_node *ref_node;
7304 bool needs_switch = false;
7306 if (check_add_overflow(up->offset, nr_args, &done))
7308 if (done > ctx->nr_user_files)
7311 ref_node = alloc_fixed_file_ref_node(ctx);
7312 if (IS_ERR(ref_node))
7313 return PTR_ERR(ref_node);
7316 fds = u64_to_user_ptr(up->fds);
7318 struct fixed_file_table *table;
7322 if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
7326 i = array_index_nospec(up->offset, ctx->nr_user_files);
7327 table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
7328 index = i & IORING_FILE_TABLE_MASK;
7329 if (table->files[index]) {
7330 file = io_file_from_index(ctx, index);
7331 err = io_queue_file_removal(data, file);
7334 table->files[index] = NULL;
7335 needs_switch = true;
7344 * Don't allow io_uring instances to be registered. If
7345 * UNIX isn't enabled, then this causes a reference
7346 * cycle and this instance can never get freed. If UNIX
7347 * is enabled we'll handle it just fine, but there's
7348 * still no point in allowing a ring fd as it doesn't
7349 * support regular read/write anyway.
7351 if (file->f_op == &io_uring_fops) {
7356 table->files[index] = file;
7357 err = io_sqe_file_register(ctx, file, i);
7369 percpu_ref_kill(data->cur_refs);
7370 spin_lock(&data->lock);
7371 list_add(&ref_node->node, &data->ref_list);
7372 data->cur_refs = &ref_node->refs;
7373 spin_unlock(&data->lock);
7374 percpu_ref_get(&ctx->file_data->refs);
7376 destroy_fixed_file_ref_node(ref_node);
7378 return done ? done : err;
7381 static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
7384 struct io_uring_files_update up;
7386 if (!ctx->file_data)
7390 if (copy_from_user(&up, arg, sizeof(up)))
7395 return __io_sqe_files_update(ctx, &up, nr_args);
7398 static void io_free_work(struct io_wq_work *work)
7400 struct io_kiocb *req = container_of(work, struct io_kiocb, work);
7402 /* Consider that io_steal_work() relies on this ref */
7406 static int io_init_wq_offload(struct io_ring_ctx *ctx,
7407 struct io_uring_params *p)
7409 struct io_wq_data data;
7411 struct io_ring_ctx *ctx_attach;
7412 unsigned int concurrency;
7415 data.user = ctx->user;
7416 data.free_work = io_free_work;
7417 data.do_work = io_wq_submit_work;
7419 if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {
7420 /* Do QD, or 4 * CPUS, whatever is smallest */
7421 concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
7423 ctx->io_wq = io_wq_create(concurrency, &data);
7424 if (IS_ERR(ctx->io_wq)) {
7425 ret = PTR_ERR(ctx->io_wq);
7431 f = fdget(p->wq_fd);
7435 if (f.file->f_op != &io_uring_fops) {
7440 ctx_attach = f.file->private_data;
7441 /* @io_wq is protected by holding the fd */
7442 if (!io_wq_get(ctx_attach->io_wq, &data)) {
7447 ctx->io_wq = ctx_attach->io_wq;
7453 static int io_sq_offload_start(struct io_ring_ctx *ctx,
7454 struct io_uring_params *p)
7458 mmgrab(current->mm);
7459 ctx->sqo_mm = current->mm;
7461 if (ctx->flags & IORING_SETUP_SQPOLL) {
7463 if (!capable(CAP_SYS_ADMIN))
7466 ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
7467 if (!ctx->sq_thread_idle)
7468 ctx->sq_thread_idle = HZ;
7470 if (p->flags & IORING_SETUP_SQ_AFF) {
7471 int cpu = p->sq_thread_cpu;
7474 if (cpu >= nr_cpu_ids)
7476 if (!cpu_online(cpu))
7479 ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread,
7483 ctx->sqo_thread = kthread_create(io_sq_thread, ctx,
7486 if (IS_ERR(ctx->sqo_thread)) {
7487 ret = PTR_ERR(ctx->sqo_thread);
7488 ctx->sqo_thread = NULL;
7491 wake_up_process(ctx->sqo_thread);
7492 } else if (p->flags & IORING_SETUP_SQ_AFF) {
7493 /* Can't have SQ_AFF without SQPOLL */
7498 ret = io_init_wq_offload(ctx, p);
7504 io_finish_async(ctx);
7506 mmdrop(ctx->sqo_mm);
7512 static inline void __io_unaccount_mem(struct user_struct *user,
7513 unsigned long nr_pages)
7515 atomic_long_sub(nr_pages, &user->locked_vm);
7518 static inline int __io_account_mem(struct user_struct *user,
7519 unsigned long nr_pages)
7521 unsigned long page_limit, cur_pages, new_pages;
7523 /* Don't allow more pages than we can safely lock */
7524 page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
7527 cur_pages = atomic_long_read(&user->locked_vm);
7528 new_pages = cur_pages + nr_pages;
7529 if (new_pages > page_limit)
7531 } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
7532 new_pages) != cur_pages);
7537 static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
7538 enum io_mem_account acct)
7541 __io_unaccount_mem(ctx->user, nr_pages);
7544 if (acct == ACCT_LOCKED)
7545 ctx->sqo_mm->locked_vm -= nr_pages;
7546 else if (acct == ACCT_PINNED)
7547 atomic64_sub(nr_pages, &ctx->sqo_mm->pinned_vm);
7551 static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
7552 enum io_mem_account acct)
7556 if (ctx->limit_mem) {
7557 ret = __io_account_mem(ctx->user, nr_pages);
7563 if (acct == ACCT_LOCKED)
7564 ctx->sqo_mm->locked_vm += nr_pages;
7565 else if (acct == ACCT_PINNED)
7566 atomic64_add(nr_pages, &ctx->sqo_mm->pinned_vm);
7572 static void io_mem_free(void *ptr)
7579 page = virt_to_head_page(ptr);
7580 if (put_page_testzero(page))
7581 free_compound_page(page);
7584 static void *io_mem_alloc(size_t size)
7586 gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
7589 return (void *) __get_free_pages(gfp_flags, get_order(size));
7592 static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
7595 struct io_rings *rings;
7596 size_t off, sq_array_size;
7598 off = struct_size(rings, cqes, cq_entries);
7599 if (off == SIZE_MAX)
7603 off = ALIGN(off, SMP_CACHE_BYTES);
7611 sq_array_size = array_size(sizeof(u32), sq_entries);
7612 if (sq_array_size == SIZE_MAX)
7615 if (check_add_overflow(off, sq_array_size, &off))
7621 static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
7625 pages = (size_t)1 << get_order(
7626 rings_size(sq_entries, cq_entries, NULL));
7627 pages += (size_t)1 << get_order(
7628 array_size(sizeof(struct io_uring_sqe), sq_entries));
7633 static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
7637 if (!ctx->user_bufs)
7640 for (i = 0; i < ctx->nr_user_bufs; i++) {
7641 struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
7643 for (j = 0; j < imu->nr_bvecs; j++)
7644 unpin_user_page(imu->bvec[j].bv_page);
7646 io_unaccount_mem(ctx, imu->nr_bvecs, ACCT_PINNED);
7651 kfree(ctx->user_bufs);
7652 ctx->user_bufs = NULL;
7653 ctx->nr_user_bufs = 0;
7657 static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
7658 void __user *arg, unsigned index)
7660 struct iovec __user *src;
7662 #ifdef CONFIG_COMPAT
7664 struct compat_iovec __user *ciovs;
7665 struct compat_iovec ciov;
7667 ciovs = (struct compat_iovec __user *) arg;
7668 if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
7671 dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
7672 dst->iov_len = ciov.iov_len;
7676 src = (struct iovec __user *) arg;
7677 if (copy_from_user(dst, &src[index], sizeof(*dst)))
7682 static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
7685 struct vm_area_struct **vmas = NULL;
7686 struct page **pages = NULL;
7687 int i, j, got_pages = 0;
7692 if (!nr_args || nr_args > UIO_MAXIOV)
7695 ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
7697 if (!ctx->user_bufs)
7700 for (i = 0; i < nr_args; i++) {
7701 struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
7702 unsigned long off, start, end, ubuf;
7707 ret = io_copy_iov(ctx, &iov, arg, i);
7712 * Don't impose further limits on the size and buffer
7713 * constraints here, we'll -EINVAL later when IO is
7714 * submitted if they are wrong.
7717 if (!iov.iov_base || !iov.iov_len)
7720 /* arbitrary limit, but we need something */
7721 if (iov.iov_len > SZ_1G)
7724 ubuf = (unsigned long) iov.iov_base;
7725 end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
7726 start = ubuf >> PAGE_SHIFT;
7727 nr_pages = end - start;
7729 ret = io_account_mem(ctx, nr_pages, ACCT_PINNED);
7734 if (!pages || nr_pages > got_pages) {
7737 pages = kvmalloc_array(nr_pages, sizeof(struct page *),
7739 vmas = kvmalloc_array(nr_pages,
7740 sizeof(struct vm_area_struct *),
7742 if (!pages || !vmas) {
7744 io_unaccount_mem(ctx, nr_pages, ACCT_PINNED);
7747 got_pages = nr_pages;
7750 imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
7754 io_unaccount_mem(ctx, nr_pages, ACCT_PINNED);
7759 mmap_read_lock(current->mm);
7760 pret = pin_user_pages(ubuf, nr_pages,
7761 FOLL_WRITE | FOLL_LONGTERM,
7763 if (pret == nr_pages) {
7764 /* don't support file backed memory */
7765 for (j = 0; j < nr_pages; j++) {
7766 struct vm_area_struct *vma = vmas[j];
7769 !is_file_hugepages(vma->vm_file)) {
7775 ret = pret < 0 ? pret : -EFAULT;
7777 mmap_read_unlock(current->mm);
7780 * if we did partial map, or found file backed vmas,
7781 * release any pages we did get
7784 unpin_user_pages(pages, pret);
7785 io_unaccount_mem(ctx, nr_pages, ACCT_PINNED);
7790 off = ubuf & ~PAGE_MASK;
7792 for (j = 0; j < nr_pages; j++) {
7795 vec_len = min_t(size_t, size, PAGE_SIZE - off);
7796 imu->bvec[j].bv_page = pages[j];
7797 imu->bvec[j].bv_len = vec_len;
7798 imu->bvec[j].bv_offset = off;
7802 /* store original address for later verification */
7804 imu->len = iov.iov_len;
7805 imu->nr_bvecs = nr_pages;
7807 ctx->nr_user_bufs++;
7815 io_sqe_buffer_unregister(ctx);
7819 static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
7821 __s32 __user *fds = arg;
7827 if (copy_from_user(&fd, fds, sizeof(*fds)))
7830 ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
7831 if (IS_ERR(ctx->cq_ev_fd)) {
7832 int ret = PTR_ERR(ctx->cq_ev_fd);
7833 ctx->cq_ev_fd = NULL;
7840 static int io_eventfd_unregister(struct io_ring_ctx *ctx)
7842 if (ctx->cq_ev_fd) {
7843 eventfd_ctx_put(ctx->cq_ev_fd);
7844 ctx->cq_ev_fd = NULL;
7851 static int __io_destroy_buffers(int id, void *p, void *data)
7853 struct io_ring_ctx *ctx = data;
7854 struct io_buffer *buf = p;
7856 __io_remove_buffers(ctx, buf, id, -1U);
7860 static void io_destroy_buffers(struct io_ring_ctx *ctx)
7862 idr_for_each(&ctx->io_buffer_idr, __io_destroy_buffers, ctx);
7863 idr_destroy(&ctx->io_buffer_idr);
7866 static void io_ring_ctx_free(struct io_ring_ctx *ctx)
7868 io_finish_async(ctx);
7869 io_sqe_buffer_unregister(ctx);
7871 mmdrop(ctx->sqo_mm);
7875 io_sqe_files_unregister(ctx);
7876 io_eventfd_unregister(ctx);
7877 io_destroy_buffers(ctx);
7878 idr_destroy(&ctx->personality_idr);
7880 #if defined(CONFIG_UNIX)
7881 if (ctx->ring_sock) {
7882 ctx->ring_sock->file = NULL; /* so that iput() is called */
7883 sock_release(ctx->ring_sock);
7887 io_mem_free(ctx->rings);
7888 io_mem_free(ctx->sq_sqes);
7890 percpu_ref_exit(&ctx->refs);
7891 free_uid(ctx->user);
7892 put_cred(ctx->creds);
7893 kfree(ctx->cancel_hash);
7894 kmem_cache_free(req_cachep, ctx->fallback_req);
7898 static __poll_t io_uring_poll(struct file *file, poll_table *wait)
7900 struct io_ring_ctx *ctx = file->private_data;
7903 poll_wait(file, &ctx->cq_wait, wait);
7905 * synchronizes with barrier from wq_has_sleeper call in
7909 if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head !=
7910 ctx->rings->sq_ring_entries)
7911 mask |= EPOLLOUT | EPOLLWRNORM;
7912 if (io_cqring_events(ctx, false))
7913 mask |= EPOLLIN | EPOLLRDNORM;
7918 static int io_uring_fasync(int fd, struct file *file, int on)
7920 struct io_ring_ctx *ctx = file->private_data;
7922 return fasync_helper(fd, file, on, &ctx->cq_fasync);
7925 static int io_remove_personalities(int id, void *p, void *data)
7927 struct io_ring_ctx *ctx = data;
7928 const struct cred *cred;
7930 cred = idr_remove(&ctx->personality_idr, id);
7936 static void io_ring_exit_work(struct work_struct *work)
7938 struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
7942 * If we're doing polled IO and end up having requests being
7943 * submitted async (out-of-line), then completions can come in while
7944 * we're waiting for refs to drop. We need to reap these manually,
7945 * as nobody else will be looking for them.
7949 io_cqring_overflow_flush(ctx, true);
7950 io_iopoll_try_reap_events(ctx);
7951 } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20));
7952 io_ring_ctx_free(ctx);
7955 static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
7957 mutex_lock(&ctx->uring_lock);
7958 percpu_ref_kill(&ctx->refs);
7959 mutex_unlock(&ctx->uring_lock);
7961 io_kill_timeouts(ctx);
7962 io_poll_remove_all(ctx);
7965 io_wq_cancel_all(ctx->io_wq);
7967 /* if we failed setting up the ctx, we might not have any rings */
7969 io_cqring_overflow_flush(ctx, true);
7970 io_iopoll_try_reap_events(ctx);
7971 idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx);
7974 * Do this upfront, so we won't have a grace period where the ring
7975 * is closed but resources aren't reaped yet. This can cause
7976 * spurious failure in setting up a new ring.
7978 io_unaccount_mem(ctx, ring_pages(ctx->sq_entries, ctx->cq_entries),
7981 INIT_WORK(&ctx->exit_work, io_ring_exit_work);
7982 queue_work(system_wq, &ctx->exit_work);
7985 static int io_uring_release(struct inode *inode, struct file *file)
7987 struct io_ring_ctx *ctx = file->private_data;
7989 file->private_data = NULL;
7990 io_ring_ctx_wait_and_kill(ctx);
7994 static bool io_wq_files_match(struct io_wq_work *work, void *data)
7996 struct files_struct *files = data;
7998 return work->files == files;
8002 * Returns true if 'preq' is the link parent of 'req'
8004 static bool io_match_link(struct io_kiocb *preq, struct io_kiocb *req)
8006 struct io_kiocb *link;
8008 if (!(preq->flags & REQ_F_LINK_HEAD))
8011 list_for_each_entry(link, &preq->link_list, link_list) {
8020 * We're looking to cancel 'req' because it's holding on to our files, but
8021 * 'req' could be a link to another request. See if it is, and cancel that
8022 * parent request if so.
8024 static bool io_poll_remove_link(struct io_ring_ctx *ctx, struct io_kiocb *req)
8026 struct hlist_node *tmp;
8027 struct io_kiocb *preq;
8031 spin_lock_irq(&ctx->completion_lock);
8032 for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
8033 struct hlist_head *list;
8035 list = &ctx->cancel_hash[i];
8036 hlist_for_each_entry_safe(preq, tmp, list, hash_node) {
8037 found = io_match_link(preq, req);
8039 io_poll_remove_one(preq);
8044 spin_unlock_irq(&ctx->completion_lock);
8048 static bool io_timeout_remove_link(struct io_ring_ctx *ctx,
8049 struct io_kiocb *req)
8051 struct io_kiocb *preq;
8054 spin_lock_irq(&ctx->completion_lock);
8055 list_for_each_entry(preq, &ctx->timeout_list, timeout.list) {
8056 found = io_match_link(preq, req);
8058 __io_timeout_cancel(preq);
8062 spin_unlock_irq(&ctx->completion_lock);
8066 static bool io_cancel_link_cb(struct io_wq_work *work, void *data)
8068 return io_match_link(container_of(work, struct io_kiocb, work), data);
8071 static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
8073 enum io_wq_cancel cret;
8075 /* cancel this particular work, if it's running */
8076 cret = io_wq_cancel_work(ctx->io_wq, &req->work);
8077 if (cret != IO_WQ_CANCEL_NOTFOUND)
8080 /* find links that hold this pending, cancel those */
8081 cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_link_cb, req, true);
8082 if (cret != IO_WQ_CANCEL_NOTFOUND)
8085 /* if we have a poll link holding this pending, cancel that */
8086 if (io_poll_remove_link(ctx, req))
8089 /* final option, timeout link is holding this req pending */
8090 io_timeout_remove_link(ctx, req);
8093 static void io_uring_cancel_files(struct io_ring_ctx *ctx,
8094 struct files_struct *files)
8096 if (list_empty_careful(&ctx->inflight_list))
8099 /* cancel all at once, should be faster than doing it one by one*/
8100 io_wq_cancel_cb(ctx->io_wq, io_wq_files_match, files, true);
8102 while (!list_empty_careful(&ctx->inflight_list)) {
8103 struct io_kiocb *cancel_req = NULL, *req;
8106 spin_lock_irq(&ctx->inflight_lock);
8107 list_for_each_entry(req, &ctx->inflight_list, inflight_entry) {
8108 if (req->work.files != files)
8110 /* req is being completed, ignore */
8111 if (!refcount_inc_not_zero(&req->refs))
8117 prepare_to_wait(&ctx->inflight_wait, &wait,
8118 TASK_UNINTERRUPTIBLE);
8119 spin_unlock_irq(&ctx->inflight_lock);
8121 /* We need to keep going until we don't find a matching req */
8125 if (cancel_req->flags & REQ_F_OVERFLOW) {
8126 spin_lock_irq(&ctx->completion_lock);
8127 list_del(&cancel_req->compl.list);
8128 cancel_req->flags &= ~REQ_F_OVERFLOW;
8130 io_cqring_mark_overflow(ctx);
8131 WRITE_ONCE(ctx->rings->cq_overflow,
8132 atomic_inc_return(&ctx->cached_cq_overflow));
8133 io_commit_cqring(ctx);
8134 spin_unlock_irq(&ctx->completion_lock);
8137 * Put inflight ref and overflow ref. If that's
8138 * all we had, then we're done with this request.
8140 if (refcount_sub_and_test(2, &cancel_req->refs)) {
8141 io_free_req(cancel_req);
8142 finish_wait(&ctx->inflight_wait, &wait);
8146 /* cancel this request, or head link requests */
8147 io_attempt_cancel(ctx, cancel_req);
8148 io_put_req(cancel_req);
8152 finish_wait(&ctx->inflight_wait, &wait);
8156 static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
8158 struct io_kiocb *req = container_of(work, struct io_kiocb, work);
8159 struct task_struct *task = data;
8161 return req->task == task;
8164 static int io_uring_flush(struct file *file, void *data)
8166 struct io_ring_ctx *ctx = file->private_data;
8168 io_uring_cancel_files(ctx, data);
8171 * If the task is going away, cancel work it may have pending
8173 if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
8174 io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, current, true);
8179 static void *io_uring_validate_mmap_request(struct file *file,
8180 loff_t pgoff, size_t sz)
8182 struct io_ring_ctx *ctx = file->private_data;
8183 loff_t offset = pgoff << PAGE_SHIFT;
8188 case IORING_OFF_SQ_RING:
8189 case IORING_OFF_CQ_RING:
8192 case IORING_OFF_SQES:
8196 return ERR_PTR(-EINVAL);
8199 page = virt_to_head_page(ptr);
8200 if (sz > page_size(page))
8201 return ERR_PTR(-EINVAL);
8208 static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
8210 size_t sz = vma->vm_end - vma->vm_start;
8214 ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
8216 return PTR_ERR(ptr);
8218 pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
8219 return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
8222 #else /* !CONFIG_MMU */
8224 static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
8226 return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
8229 static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
8231 return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
8234 static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
8235 unsigned long addr, unsigned long len,
8236 unsigned long pgoff, unsigned long flags)
8240 ptr = io_uring_validate_mmap_request(file, pgoff, len);
8242 return PTR_ERR(ptr);
8244 return (unsigned long) ptr;
8247 #endif /* !CONFIG_MMU */
8249 SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
8250 u32, min_complete, u32, flags, const sigset_t __user *, sig,
8253 struct io_ring_ctx *ctx;
8260 if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP))
8268 if (f.file->f_op != &io_uring_fops)
8272 ctx = f.file->private_data;
8273 if (!percpu_ref_tryget(&ctx->refs))
8277 * For SQ polling, the thread will do all submissions and completions.
8278 * Just return the requested submit count, and wake the thread if
8282 if (ctx->flags & IORING_SETUP_SQPOLL) {
8283 if (!list_empty_careful(&ctx->cq_overflow_list))
8284 io_cqring_overflow_flush(ctx, false);
8285 if (flags & IORING_ENTER_SQ_WAKEUP)
8286 wake_up(&ctx->sqo_wait);
8287 submitted = to_submit;
8288 } else if (to_submit) {
8289 mutex_lock(&ctx->uring_lock);
8290 submitted = io_submit_sqes(ctx, to_submit, f.file, fd);
8291 mutex_unlock(&ctx->uring_lock);
8293 if (submitted != to_submit)
8296 if (flags & IORING_ENTER_GETEVENTS) {
8297 min_complete = min(min_complete, ctx->cq_entries);
8300 * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
8301 * space applications don't need to do io completion events
8302 * polling again, they can rely on io_sq_thread to do polling
8303 * work, which can reduce cpu usage and uring_lock contention.
8305 if (ctx->flags & IORING_SETUP_IOPOLL &&
8306 !(ctx->flags & IORING_SETUP_SQPOLL)) {
8307 ret = io_iopoll_check(ctx, min_complete);
8309 ret = io_cqring_wait(ctx, min_complete, sig, sigsz);
8314 percpu_ref_put(&ctx->refs);
8317 return submitted ? submitted : ret;
8320 #ifdef CONFIG_PROC_FS
8321 static int io_uring_show_cred(int id, void *p, void *data)
8323 const struct cred *cred = p;
8324 struct seq_file *m = data;
8325 struct user_namespace *uns = seq_user_ns(m);
8326 struct group_info *gi;
8331 seq_printf(m, "%5d\n", id);
8332 seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
8333 seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
8334 seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
8335 seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
8336 seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
8337 seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
8338 seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
8339 seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
8340 seq_puts(m, "\n\tGroups:\t");
8341 gi = cred->group_info;
8342 for (g = 0; g < gi->ngroups; g++) {
8343 seq_put_decimal_ull(m, g ? " " : "",
8344 from_kgid_munged(uns, gi->gid[g]));
8346 seq_puts(m, "\n\tCapEff:\t");
8347 cap = cred->cap_effective;
8348 CAP_FOR_EACH_U32(__capi)
8349 seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
8354 static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
8358 mutex_lock(&ctx->uring_lock);
8359 seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
8360 for (i = 0; i < ctx->nr_user_files; i++) {
8361 struct fixed_file_table *table;
8364 table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
8365 f = table->files[i & IORING_FILE_TABLE_MASK];
8367 seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
8369 seq_printf(m, "%5u: <none>\n", i);
8371 seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
8372 for (i = 0; i < ctx->nr_user_bufs; i++) {
8373 struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
8375 seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
8376 (unsigned int) buf->len);
8378 if (!idr_is_empty(&ctx->personality_idr)) {
8379 seq_printf(m, "Personalities:\n");
8380 idr_for_each(&ctx->personality_idr, io_uring_show_cred, m);
8382 seq_printf(m, "PollList:\n");
8383 spin_lock_irq(&ctx->completion_lock);
8384 for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
8385 struct hlist_head *list = &ctx->cancel_hash[i];
8386 struct io_kiocb *req;
8388 hlist_for_each_entry(req, list, hash_node)
8389 seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
8390 req->task->task_works != NULL);
8392 spin_unlock_irq(&ctx->completion_lock);
8393 mutex_unlock(&ctx->uring_lock);
8396 static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
8398 struct io_ring_ctx *ctx = f->private_data;
8400 if (percpu_ref_tryget(&ctx->refs)) {
8401 __io_uring_show_fdinfo(ctx, m);
8402 percpu_ref_put(&ctx->refs);
8407 static const struct file_operations io_uring_fops = {
8408 .release = io_uring_release,
8409 .flush = io_uring_flush,
8410 .mmap = io_uring_mmap,
8412 .get_unmapped_area = io_uring_nommu_get_unmapped_area,
8413 .mmap_capabilities = io_uring_nommu_mmap_capabilities,
8415 .poll = io_uring_poll,
8416 .fasync = io_uring_fasync,
8417 #ifdef CONFIG_PROC_FS
8418 .show_fdinfo = io_uring_show_fdinfo,
8422 static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
8423 struct io_uring_params *p)
8425 struct io_rings *rings;
8426 size_t size, sq_array_offset;
8428 /* make sure these are sane, as we already accounted them */
8429 ctx->sq_entries = p->sq_entries;
8430 ctx->cq_entries = p->cq_entries;
8432 size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
8433 if (size == SIZE_MAX)
8436 rings = io_mem_alloc(size);
8441 ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
8442 rings->sq_ring_mask = p->sq_entries - 1;
8443 rings->cq_ring_mask = p->cq_entries - 1;
8444 rings->sq_ring_entries = p->sq_entries;
8445 rings->cq_ring_entries = p->cq_entries;
8446 ctx->sq_mask = rings->sq_ring_mask;
8447 ctx->cq_mask = rings->cq_ring_mask;
8449 size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
8450 if (size == SIZE_MAX) {
8451 io_mem_free(ctx->rings);
8456 ctx->sq_sqes = io_mem_alloc(size);
8457 if (!ctx->sq_sqes) {
8458 io_mem_free(ctx->rings);
8467 * Allocate an anonymous fd, this is what constitutes the application
8468 * visible backing of an io_uring instance. The application mmaps this
8469 * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
8470 * we have to tie this fd to a socket for file garbage collection purposes.
8472 static int io_uring_get_fd(struct io_ring_ctx *ctx)
8477 #if defined(CONFIG_UNIX)
8478 ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
8484 ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
8488 file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
8489 O_RDWR | O_CLOEXEC);
8492 ret = PTR_ERR(file);
8496 #if defined(CONFIG_UNIX)
8497 ctx->ring_sock->file = file;
8499 fd_install(ret, file);
8502 #if defined(CONFIG_UNIX)
8503 sock_release(ctx->ring_sock);
8504 ctx->ring_sock = NULL;
8509 static int io_uring_create(unsigned entries, struct io_uring_params *p,
8510 struct io_uring_params __user *params)
8512 struct user_struct *user = NULL;
8513 struct io_ring_ctx *ctx;
8519 if (entries > IORING_MAX_ENTRIES) {
8520 if (!(p->flags & IORING_SETUP_CLAMP))
8522 entries = IORING_MAX_ENTRIES;
8526 * Use twice as many entries for the CQ ring. It's possible for the
8527 * application to drive a higher depth than the size of the SQ ring,
8528 * since the sqes are only used at submission time. This allows for
8529 * some flexibility in overcommitting a bit. If the application has
8530 * set IORING_SETUP_CQSIZE, it will have passed in the desired number
8531 * of CQ ring entries manually.
8533 p->sq_entries = roundup_pow_of_two(entries);
8534 if (p->flags & IORING_SETUP_CQSIZE) {
8536 * If IORING_SETUP_CQSIZE is set, we do the same roundup
8537 * to a power-of-two, if it isn't already. We do NOT impose
8538 * any cq vs sq ring sizing.
8540 if (p->cq_entries < p->sq_entries)
8542 if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
8543 if (!(p->flags & IORING_SETUP_CLAMP))
8545 p->cq_entries = IORING_MAX_CQ_ENTRIES;
8547 p->cq_entries = roundup_pow_of_two(p->cq_entries);
8549 p->cq_entries = 2 * p->sq_entries;
8552 user = get_uid(current_user());
8553 limit_mem = !capable(CAP_IPC_LOCK);
8556 ret = __io_account_mem(user,
8557 ring_pages(p->sq_entries, p->cq_entries));
8564 ctx = io_ring_ctx_alloc(p);
8567 __io_unaccount_mem(user, ring_pages(p->sq_entries,
8572 ctx->compat = in_compat_syscall();
8574 ctx->creds = get_current_cred();
8577 * Account memory _before_ installing the file descriptor. Once
8578 * the descriptor is installed, it can get closed at any time. Also
8579 * do this before hitting the general error path, as ring freeing
8580 * will un-account as well.
8582 io_account_mem(ctx, ring_pages(p->sq_entries, p->cq_entries),
8584 ctx->limit_mem = limit_mem;
8586 ret = io_allocate_scq_urings(ctx, p);
8590 ret = io_sq_offload_start(ctx, p);
8594 memset(&p->sq_off, 0, sizeof(p->sq_off));
8595 p->sq_off.head = offsetof(struct io_rings, sq.head);
8596 p->sq_off.tail = offsetof(struct io_rings, sq.tail);
8597 p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
8598 p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
8599 p->sq_off.flags = offsetof(struct io_rings, sq_flags);
8600 p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
8601 p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
8603 memset(&p->cq_off, 0, sizeof(p->cq_off));
8604 p->cq_off.head = offsetof(struct io_rings, cq.head);
8605 p->cq_off.tail = offsetof(struct io_rings, cq.tail);
8606 p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
8607 p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
8608 p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
8609 p->cq_off.cqes = offsetof(struct io_rings, cqes);
8610 p->cq_off.flags = offsetof(struct io_rings, cq_flags);
8612 p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
8613 IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
8614 IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL |
8615 IORING_FEAT_POLL_32BITS;
8617 if (copy_to_user(params, p, sizeof(*p))) {
8623 * Install ring fd as the very last thing, so we don't risk someone
8624 * having closed it before we finish setup
8626 ret = io_uring_get_fd(ctx);
8630 trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
8633 io_ring_ctx_wait_and_kill(ctx);
8638 * Sets up an aio uring context, and returns the fd. Applications asks for a
8639 * ring size, we return the actual sq/cq ring sizes (among other things) in the
8640 * params structure passed in.
8642 static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
8644 struct io_uring_params p;
8647 if (copy_from_user(&p, params, sizeof(p)))
8649 for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
8654 if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
8655 IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
8656 IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ))
8659 return io_uring_create(entries, &p, params);
8662 SYSCALL_DEFINE2(io_uring_setup, u32, entries,
8663 struct io_uring_params __user *, params)
8665 return io_uring_setup(entries, params);
8668 static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
8670 struct io_uring_probe *p;
8674 size = struct_size(p, ops, nr_args);
8675 if (size == SIZE_MAX)
8677 p = kzalloc(size, GFP_KERNEL);
8682 if (copy_from_user(p, arg, size))
8685 if (memchr_inv(p, 0, size))
8688 p->last_op = IORING_OP_LAST - 1;
8689 if (nr_args > IORING_OP_LAST)
8690 nr_args = IORING_OP_LAST;
8692 for (i = 0; i < nr_args; i++) {
8694 if (!io_op_defs[i].not_supported)
8695 p->ops[i].flags = IO_URING_OP_SUPPORTED;
8700 if (copy_to_user(arg, p, size))
8707 static int io_register_personality(struct io_ring_ctx *ctx)
8709 const struct cred *creds = get_current_cred();
8712 id = idr_alloc_cyclic(&ctx->personality_idr, (void *) creds, 1,
8713 USHRT_MAX, GFP_KERNEL);
8719 static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
8721 const struct cred *old_creds;
8723 old_creds = idr_remove(&ctx->personality_idr, id);
8725 put_cred(old_creds);
8732 static bool io_register_op_must_quiesce(int op)
8735 case IORING_UNREGISTER_FILES:
8736 case IORING_REGISTER_FILES_UPDATE:
8737 case IORING_REGISTER_PROBE:
8738 case IORING_REGISTER_PERSONALITY:
8739 case IORING_UNREGISTER_PERSONALITY:
8746 static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
8747 void __user *arg, unsigned nr_args)
8748 __releases(ctx->uring_lock)
8749 __acquires(ctx->uring_lock)
8754 * We're inside the ring mutex, if the ref is already dying, then
8755 * someone else killed the ctx or is already going through
8756 * io_uring_register().
8758 if (percpu_ref_is_dying(&ctx->refs))
8761 if (io_register_op_must_quiesce(opcode)) {
8762 percpu_ref_kill(&ctx->refs);
8765 * Drop uring mutex before waiting for references to exit. If
8766 * another thread is currently inside io_uring_enter() it might
8767 * need to grab the uring_lock to make progress. If we hold it
8768 * here across the drain wait, then we can deadlock. It's safe
8769 * to drop the mutex here, since no new references will come in
8770 * after we've killed the percpu ref.
8772 mutex_unlock(&ctx->uring_lock);
8773 ret = wait_for_completion_interruptible(&ctx->ref_comp);
8774 mutex_lock(&ctx->uring_lock);
8776 percpu_ref_resurrect(&ctx->refs);
8783 case IORING_REGISTER_BUFFERS:
8784 ret = io_sqe_buffer_register(ctx, arg, nr_args);
8786 case IORING_UNREGISTER_BUFFERS:
8790 ret = io_sqe_buffer_unregister(ctx);
8792 case IORING_REGISTER_FILES:
8793 ret = io_sqe_files_register(ctx, arg, nr_args);
8795 case IORING_UNREGISTER_FILES:
8799 ret = io_sqe_files_unregister(ctx);
8801 case IORING_REGISTER_FILES_UPDATE:
8802 ret = io_sqe_files_update(ctx, arg, nr_args);
8804 case IORING_REGISTER_EVENTFD:
8805 case IORING_REGISTER_EVENTFD_ASYNC:
8809 ret = io_eventfd_register(ctx, arg);
8812 if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
8813 ctx->eventfd_async = 1;
8815 ctx->eventfd_async = 0;
8817 case IORING_UNREGISTER_EVENTFD:
8821 ret = io_eventfd_unregister(ctx);
8823 case IORING_REGISTER_PROBE:
8825 if (!arg || nr_args > 256)
8827 ret = io_probe(ctx, arg, nr_args);
8829 case IORING_REGISTER_PERSONALITY:
8833 ret = io_register_personality(ctx);
8835 case IORING_UNREGISTER_PERSONALITY:
8839 ret = io_unregister_personality(ctx, nr_args);
8846 if (io_register_op_must_quiesce(opcode)) {
8847 /* bring the ctx back to life */
8848 percpu_ref_reinit(&ctx->refs);
8850 reinit_completion(&ctx->ref_comp);
8855 SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
8856 void __user *, arg, unsigned int, nr_args)
8858 struct io_ring_ctx *ctx;
8867 if (f.file->f_op != &io_uring_fops)
8870 ctx = f.file->private_data;
8872 mutex_lock(&ctx->uring_lock);
8873 ret = __io_uring_register(ctx, opcode, arg, nr_args);
8874 mutex_unlock(&ctx->uring_lock);
8875 trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
8876 ctx->cq_ev_fd != NULL, ret);
8882 static int __init io_uring_init(void)
8884 #define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
8885 BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
8886 BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
8889 #define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
8890 __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
8891 BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
8892 BUILD_BUG_SQE_ELEM(0, __u8, opcode);
8893 BUILD_BUG_SQE_ELEM(1, __u8, flags);
8894 BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
8895 BUILD_BUG_SQE_ELEM(4, __s32, fd);
8896 BUILD_BUG_SQE_ELEM(8, __u64, off);
8897 BUILD_BUG_SQE_ELEM(8, __u64, addr2);
8898 BUILD_BUG_SQE_ELEM(16, __u64, addr);
8899 BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
8900 BUILD_BUG_SQE_ELEM(24, __u32, len);
8901 BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
8902 BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
8903 BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
8904 BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
8905 BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
8906 BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
8907 BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
8908 BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
8909 BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
8910 BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
8911 BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
8912 BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
8913 BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
8914 BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
8915 BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
8916 BUILD_BUG_SQE_ELEM(32, __u64, user_data);
8917 BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
8918 BUILD_BUG_SQE_ELEM(42, __u16, personality);
8919 BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
8921 BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
8922 BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
8923 req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
8926 __initcall(io_uring_init);