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 <linux/refcount.h>
48 #include <linux/uio.h>
49 #include <linux/bits.h>
51 #include <linux/sched/signal.h>
53 #include <linux/file.h>
54 #include <linux/fdtable.h>
56 #include <linux/mman.h>
57 #include <linux/mmu_context.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>
79 #define CREATE_TRACE_POINTS
80 #include <trace/events/io_uring.h>
82 #include <uapi/linux/io_uring.h>
87 #define IORING_MAX_ENTRIES 32768
88 #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
91 * Shift of 9 is 512 entries, or exactly one page on 64-bit archs
93 #define IORING_FILE_TABLE_SHIFT 9
94 #define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT)
95 #define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1)
96 #define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE)
99 u32 head ____cacheline_aligned_in_smp
;
100 u32 tail ____cacheline_aligned_in_smp
;
104 * This data is shared with the application through the mmap at offsets
105 * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
107 * The offsets to the member fields are published through struct
108 * io_sqring_offsets when calling io_uring_setup.
112 * Head and tail offsets into the ring; the offsets need to be
113 * masked to get valid indices.
115 * The kernel controls head of the sq ring and the tail of the cq ring,
116 * and the application controls tail of the sq ring and the head of the
119 struct io_uring sq
, cq
;
121 * Bitmasks to apply to head and tail offsets (constant, equals
124 u32 sq_ring_mask
, cq_ring_mask
;
125 /* Ring sizes (constant, power of 2) */
126 u32 sq_ring_entries
, cq_ring_entries
;
128 * Number of invalid entries dropped by the kernel due to
129 * invalid index stored in array
131 * Written by the kernel, shouldn't be modified by the
132 * application (i.e. get number of "new events" by comparing to
135 * After a new SQ head value was read by the application this
136 * counter includes all submissions that were dropped reaching
137 * the new SQ head (and possibly more).
143 * Written by the kernel, shouldn't be modified by the
146 * The application needs a full memory barrier before checking
147 * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
151 * Number of completion events lost because the queue was full;
152 * this should be avoided by the application by making sure
153 * there are not more requests pending than there is space in
154 * the completion queue.
156 * Written by the kernel, shouldn't be modified by the
157 * application (i.e. get number of "new events" by comparing to
160 * As completion events come in out of order this counter is not
161 * ordered with any other data.
165 * Ring buffer of completion events.
167 * The kernel writes completion events fresh every time they are
168 * produced, so the application is allowed to modify pending
171 struct io_uring_cqe cqes
[] ____cacheline_aligned_in_smp
;
174 struct io_mapped_ubuf
{
177 struct bio_vec
*bvec
;
178 unsigned int nr_bvecs
;
181 struct fixed_file_table
{
189 struct fixed_file_data
{
190 struct fixed_file_table
*table
;
191 struct io_ring_ctx
*ctx
;
193 struct percpu_ref refs
;
194 struct llist_head put_llist
;
196 struct work_struct ref_work
;
197 struct completion done
;
202 struct percpu_ref refs
;
203 } ____cacheline_aligned_in_smp
;
209 int cq_overflow_flushed
: 1;
211 int eventfd_async
: 1;
214 * Ring buffer of indices into array of io_uring_sqe, which is
215 * mmapped by the application using the IORING_OFF_SQES offset.
217 * This indirection could e.g. be used to assign fixed
218 * io_uring_sqe entries to operations and only submit them to
219 * the queue when needed.
221 * The kernel modifies neither the indices array nor the entries
225 unsigned cached_sq_head
;
228 unsigned sq_thread_idle
;
229 unsigned cached_sq_dropped
;
230 atomic_t cached_cq_overflow
;
231 unsigned long sq_check_overflow
;
233 struct list_head defer_list
;
234 struct list_head timeout_list
;
235 struct list_head cq_overflow_list
;
237 wait_queue_head_t inflight_wait
;
238 struct io_uring_sqe
*sq_sqes
;
239 } ____cacheline_aligned_in_smp
;
241 struct io_rings
*rings
;
245 struct task_struct
*sqo_thread
; /* if using sq thread polling */
246 struct mm_struct
*sqo_mm
;
247 wait_queue_head_t sqo_wait
;
250 * If used, fixed file set. Writers must ensure that ->refs is dead,
251 * readers must ensure that ->refs is alive as long as the file* is
252 * used. Only updated through io_uring_register(2).
254 struct fixed_file_data
*file_data
;
255 unsigned nr_user_files
;
257 struct file
*ring_file
;
259 /* if used, fixed mapped user buffers */
260 unsigned nr_user_bufs
;
261 struct io_mapped_ubuf
*user_bufs
;
263 struct user_struct
*user
;
265 const struct cred
*creds
;
267 /* 0 is for ctx quiesce/reinit/free, 1 is for sqo_thread started */
268 struct completion
*completions
;
270 /* if all else fails... */
271 struct io_kiocb
*fallback_req
;
273 #if defined(CONFIG_UNIX)
274 struct socket
*ring_sock
;
277 struct idr personality_idr
;
280 unsigned cached_cq_tail
;
283 atomic_t cq_timeouts
;
284 unsigned long cq_check_overflow
;
285 struct wait_queue_head cq_wait
;
286 struct fasync_struct
*cq_fasync
;
287 struct eventfd_ctx
*cq_ev_fd
;
288 } ____cacheline_aligned_in_smp
;
291 struct mutex uring_lock
;
292 wait_queue_head_t wait
;
293 } ____cacheline_aligned_in_smp
;
296 spinlock_t completion_lock
;
297 struct llist_head poll_llist
;
300 * ->poll_list is protected by the ctx->uring_lock for
301 * io_uring instances that don't use IORING_SETUP_SQPOLL.
302 * For SQPOLL, only the single threaded io_sq_thread() will
303 * manipulate the list, hence no extra locking is needed there.
305 struct list_head poll_list
;
306 struct hlist_head
*cancel_hash
;
307 unsigned cancel_hash_bits
;
308 bool poll_multi_file
;
310 spinlock_t inflight_lock
;
311 struct list_head inflight_list
;
312 } ____cacheline_aligned_in_smp
;
316 * First field must be the file pointer in all the
317 * iocb unions! See also 'struct kiocb' in <linux/fs.h>
319 struct io_poll_iocb
{
322 struct wait_queue_head
*head
;
328 struct wait_queue_entry wait
;
333 struct file
*put_file
;
337 struct io_timeout_data
{
338 struct io_kiocb
*req
;
339 struct hrtimer timer
;
340 struct timespec64 ts
;
341 enum hrtimer_mode mode
;
347 struct sockaddr __user
*addr
;
348 int __user
*addr_len
;
373 /* NOTE: kiocb has the file as the first member, so don't do it here */
381 struct sockaddr __user
*addr
;
388 struct user_msghdr __user
*msg
;
401 struct filename
*filename
;
402 struct statx __user
*buffer
;
406 struct io_files_update
{
432 struct epoll_event event
;
435 struct io_async_connect
{
436 struct sockaddr_storage address
;
439 struct io_async_msghdr
{
440 struct iovec fast_iov
[UIO_FASTIOV
];
442 struct sockaddr __user
*uaddr
;
447 struct iovec fast_iov
[UIO_FASTIOV
];
453 struct io_async_open
{
454 struct filename
*filename
;
457 struct io_async_ctx
{
459 struct io_async_rw rw
;
460 struct io_async_msghdr msg
;
461 struct io_async_connect connect
;
462 struct io_timeout_data timeout
;
463 struct io_async_open open
;
468 REQ_F_FIXED_FILE_BIT
= IOSQE_FIXED_FILE_BIT
,
469 REQ_F_IO_DRAIN_BIT
= IOSQE_IO_DRAIN_BIT
,
470 REQ_F_LINK_BIT
= IOSQE_IO_LINK_BIT
,
471 REQ_F_HARDLINK_BIT
= IOSQE_IO_HARDLINK_BIT
,
472 REQ_F_FORCE_ASYNC_BIT
= IOSQE_ASYNC_BIT
,
479 REQ_F_IOPOLL_COMPLETED_BIT
,
480 REQ_F_LINK_TIMEOUT_BIT
,
484 REQ_F_TIMEOUT_NOSEQ_BIT
,
485 REQ_F_COMP_LOCKED_BIT
,
490 REQ_F_FIXED_FILE
= BIT(REQ_F_FIXED_FILE_BIT
),
491 /* drain existing IO first */
492 REQ_F_IO_DRAIN
= BIT(REQ_F_IO_DRAIN_BIT
),
494 REQ_F_LINK
= BIT(REQ_F_LINK_BIT
),
495 /* doesn't sever on completion < 0 */
496 REQ_F_HARDLINK
= BIT(REQ_F_HARDLINK_BIT
),
498 REQ_F_FORCE_ASYNC
= BIT(REQ_F_FORCE_ASYNC_BIT
),
500 /* already grabbed next link */
501 REQ_F_LINK_NEXT
= BIT(REQ_F_LINK_NEXT_BIT
),
502 /* fail rest of links */
503 REQ_F_FAIL_LINK
= BIT(REQ_F_FAIL_LINK_BIT
),
504 /* on inflight list */
505 REQ_F_INFLIGHT
= BIT(REQ_F_INFLIGHT_BIT
),
506 /* read/write uses file position */
507 REQ_F_CUR_POS
= BIT(REQ_F_CUR_POS_BIT
),
508 /* must not punt to workers */
509 REQ_F_NOWAIT
= BIT(REQ_F_NOWAIT_BIT
),
510 /* polled IO has completed */
511 REQ_F_IOPOLL_COMPLETED
= BIT(REQ_F_IOPOLL_COMPLETED_BIT
),
512 /* has linked timeout */
513 REQ_F_LINK_TIMEOUT
= BIT(REQ_F_LINK_TIMEOUT_BIT
),
514 /* timeout request */
515 REQ_F_TIMEOUT
= BIT(REQ_F_TIMEOUT_BIT
),
517 REQ_F_ISREG
= BIT(REQ_F_ISREG_BIT
),
518 /* must be punted even for NONBLOCK */
519 REQ_F_MUST_PUNT
= BIT(REQ_F_MUST_PUNT_BIT
),
520 /* no timeout sequence */
521 REQ_F_TIMEOUT_NOSEQ
= BIT(REQ_F_TIMEOUT_NOSEQ_BIT
),
522 /* completion under lock */
523 REQ_F_COMP_LOCKED
= BIT(REQ_F_COMP_LOCKED_BIT
),
527 * NOTE! Each of the iocb union members has the file pointer
528 * as the first entry in their struct definition. So you can
529 * access the file pointer through any of the sub-structs,
530 * or directly as just 'ki_filp' in this struct.
536 struct io_poll_iocb poll
;
537 struct io_accept accept
;
539 struct io_cancel cancel
;
540 struct io_timeout timeout
;
541 struct io_connect connect
;
542 struct io_sr_msg sr_msg
;
544 struct io_close close
;
545 struct io_files_update files_update
;
546 struct io_fadvise fadvise
;
547 struct io_madvise madvise
;
548 struct io_epoll epoll
;
551 struct io_async_ctx
*io
;
553 * llist_node is only used for poll deferred completions
555 struct llist_node llist_node
;
558 bool needs_fixed_file
;
561 struct io_ring_ctx
*ctx
;
563 struct list_head list
;
564 struct hlist_node hash_node
;
566 struct list_head link_list
;
573 struct list_head inflight_entry
;
575 struct io_wq_work work
;
578 #define IO_PLUG_THRESHOLD 2
579 #define IO_IOPOLL_BATCH 8
581 struct io_submit_state
{
582 struct blk_plug plug
;
585 * io_kiocb alloc cache
587 void *reqs
[IO_IOPOLL_BATCH
];
588 unsigned int free_reqs
;
591 * File reference cache
595 unsigned int has_refs
;
596 unsigned int used_refs
;
597 unsigned int ios_left
;
601 /* needs req->io allocated for deferral/async */
602 unsigned async_ctx
: 1;
603 /* needs current->mm setup, does mm access */
604 unsigned needs_mm
: 1;
605 /* needs req->file assigned */
606 unsigned needs_file
: 1;
607 /* needs req->file assigned IFF fd is >= 0 */
608 unsigned fd_non_neg
: 1;
609 /* hash wq insertion if file is a regular file */
610 unsigned hash_reg_file
: 1;
611 /* unbound wq insertion if file is a non-regular file */
612 unsigned unbound_nonreg_file
: 1;
613 /* opcode is not supported by this kernel */
614 unsigned not_supported
: 1;
615 /* needs file table */
616 unsigned file_table
: 1;
619 static const struct io_op_def io_op_defs
[] = {
620 [IORING_OP_NOP
] = {},
621 [IORING_OP_READV
] = {
625 .unbound_nonreg_file
= 1,
627 [IORING_OP_WRITEV
] = {
632 .unbound_nonreg_file
= 1,
634 [IORING_OP_FSYNC
] = {
637 [IORING_OP_READ_FIXED
] = {
639 .unbound_nonreg_file
= 1,
641 [IORING_OP_WRITE_FIXED
] = {
644 .unbound_nonreg_file
= 1,
646 [IORING_OP_POLL_ADD
] = {
648 .unbound_nonreg_file
= 1,
650 [IORING_OP_POLL_REMOVE
] = {},
651 [IORING_OP_SYNC_FILE_RANGE
] = {
654 [IORING_OP_SENDMSG
] = {
658 .unbound_nonreg_file
= 1,
660 [IORING_OP_RECVMSG
] = {
664 .unbound_nonreg_file
= 1,
666 [IORING_OP_TIMEOUT
] = {
670 [IORING_OP_TIMEOUT_REMOVE
] = {},
671 [IORING_OP_ACCEPT
] = {
674 .unbound_nonreg_file
= 1,
677 [IORING_OP_ASYNC_CANCEL
] = {},
678 [IORING_OP_LINK_TIMEOUT
] = {
682 [IORING_OP_CONNECT
] = {
686 .unbound_nonreg_file
= 1,
688 [IORING_OP_FALLOCATE
] = {
691 [IORING_OP_OPENAT
] = {
696 [IORING_OP_CLOSE
] = {
700 [IORING_OP_FILES_UPDATE
] = {
704 [IORING_OP_STATX
] = {
712 .unbound_nonreg_file
= 1,
714 [IORING_OP_WRITE
] = {
717 .unbound_nonreg_file
= 1,
719 [IORING_OP_FADVISE
] = {
722 [IORING_OP_MADVISE
] = {
728 .unbound_nonreg_file
= 1,
733 .unbound_nonreg_file
= 1,
735 [IORING_OP_OPENAT2
] = {
740 [IORING_OP_EPOLL_CTL
] = {
741 .unbound_nonreg_file
= 1,
746 static void io_wq_submit_work(struct io_wq_work
**workptr
);
747 static void io_cqring_fill_event(struct io_kiocb
*req
, long res
);
748 static void io_put_req(struct io_kiocb
*req
);
749 static void __io_double_put_req(struct io_kiocb
*req
);
750 static struct io_kiocb
*io_prep_linked_timeout(struct io_kiocb
*req
);
751 static void io_queue_linked_timeout(struct io_kiocb
*req
);
752 static int __io_sqe_files_update(struct io_ring_ctx
*ctx
,
753 struct io_uring_files_update
*ip
,
755 static int io_grab_files(struct io_kiocb
*req
);
756 static void io_ring_file_ref_flush(struct fixed_file_data
*data
);
758 static struct kmem_cache
*req_cachep
;
760 static const struct file_operations io_uring_fops
;
762 struct sock
*io_uring_get_socket(struct file
*file
)
764 #if defined(CONFIG_UNIX)
765 if (file
->f_op
== &io_uring_fops
) {
766 struct io_ring_ctx
*ctx
= file
->private_data
;
768 return ctx
->ring_sock
->sk
;
773 EXPORT_SYMBOL(io_uring_get_socket
);
775 static void io_ring_ctx_ref_free(struct percpu_ref
*ref
)
777 struct io_ring_ctx
*ctx
= container_of(ref
, struct io_ring_ctx
, refs
);
779 complete(&ctx
->completions
[0]);
782 static struct io_ring_ctx
*io_ring_ctx_alloc(struct io_uring_params
*p
)
784 struct io_ring_ctx
*ctx
;
787 ctx
= kzalloc(sizeof(*ctx
), GFP_KERNEL
);
791 ctx
->fallback_req
= kmem_cache_alloc(req_cachep
, GFP_KERNEL
);
792 if (!ctx
->fallback_req
)
795 ctx
->completions
= kmalloc(2 * sizeof(struct completion
), GFP_KERNEL
);
796 if (!ctx
->completions
)
800 * Use 5 bits less than the max cq entries, that should give us around
801 * 32 entries per hash list if totally full and uniformly spread.
803 hash_bits
= ilog2(p
->cq_entries
);
807 ctx
->cancel_hash_bits
= hash_bits
;
808 ctx
->cancel_hash
= kmalloc((1U << hash_bits
) * sizeof(struct hlist_head
),
810 if (!ctx
->cancel_hash
)
812 __hash_init(ctx
->cancel_hash
, 1U << hash_bits
);
814 if (percpu_ref_init(&ctx
->refs
, io_ring_ctx_ref_free
,
815 PERCPU_REF_ALLOW_REINIT
, GFP_KERNEL
))
818 ctx
->flags
= p
->flags
;
819 init_waitqueue_head(&ctx
->cq_wait
);
820 INIT_LIST_HEAD(&ctx
->cq_overflow_list
);
821 init_completion(&ctx
->completions
[0]);
822 init_completion(&ctx
->completions
[1]);
823 idr_init(&ctx
->personality_idr
);
824 mutex_init(&ctx
->uring_lock
);
825 init_waitqueue_head(&ctx
->wait
);
826 spin_lock_init(&ctx
->completion_lock
);
827 init_llist_head(&ctx
->poll_llist
);
828 INIT_LIST_HEAD(&ctx
->poll_list
);
829 INIT_LIST_HEAD(&ctx
->defer_list
);
830 INIT_LIST_HEAD(&ctx
->timeout_list
);
831 init_waitqueue_head(&ctx
->inflight_wait
);
832 spin_lock_init(&ctx
->inflight_lock
);
833 INIT_LIST_HEAD(&ctx
->inflight_list
);
836 if (ctx
->fallback_req
)
837 kmem_cache_free(req_cachep
, ctx
->fallback_req
);
838 kfree(ctx
->completions
);
839 kfree(ctx
->cancel_hash
);
844 static inline bool __req_need_defer(struct io_kiocb
*req
)
846 struct io_ring_ctx
*ctx
= req
->ctx
;
848 return req
->sequence
!= ctx
->cached_cq_tail
+ ctx
->cached_sq_dropped
849 + atomic_read(&ctx
->cached_cq_overflow
);
852 static inline bool req_need_defer(struct io_kiocb
*req
)
854 if (unlikely(req
->flags
& REQ_F_IO_DRAIN
))
855 return __req_need_defer(req
);
860 static struct io_kiocb
*io_get_deferred_req(struct io_ring_ctx
*ctx
)
862 struct io_kiocb
*req
;
864 req
= list_first_entry_or_null(&ctx
->defer_list
, struct io_kiocb
, list
);
865 if (req
&& !req_need_defer(req
)) {
866 list_del_init(&req
->list
);
873 static struct io_kiocb
*io_get_timeout_req(struct io_ring_ctx
*ctx
)
875 struct io_kiocb
*req
;
877 req
= list_first_entry_or_null(&ctx
->timeout_list
, struct io_kiocb
, list
);
879 if (req
->flags
& REQ_F_TIMEOUT_NOSEQ
)
881 if (!__req_need_defer(req
)) {
882 list_del_init(&req
->list
);
890 static void __io_commit_cqring(struct io_ring_ctx
*ctx
)
892 struct io_rings
*rings
= ctx
->rings
;
894 /* order cqe stores with ring update */
895 smp_store_release(&rings
->cq
.tail
, ctx
->cached_cq_tail
);
897 if (wq_has_sleeper(&ctx
->cq_wait
)) {
898 wake_up_interruptible(&ctx
->cq_wait
);
899 kill_fasync(&ctx
->cq_fasync
, SIGIO
, POLL_IN
);
903 static inline void io_req_work_grab_env(struct io_kiocb
*req
,
904 const struct io_op_def
*def
)
906 if (!req
->work
.mm
&& def
->needs_mm
) {
908 req
->work
.mm
= current
->mm
;
910 if (!req
->work
.creds
)
911 req
->work
.creds
= get_current_cred();
914 static inline void io_req_work_drop_env(struct io_kiocb
*req
)
917 mmdrop(req
->work
.mm
);
920 if (req
->work
.creds
) {
921 put_cred(req
->work
.creds
);
922 req
->work
.creds
= NULL
;
926 static inline bool io_prep_async_work(struct io_kiocb
*req
,
927 struct io_kiocb
**link
)
929 const struct io_op_def
*def
= &io_op_defs
[req
->opcode
];
930 bool do_hashed
= false;
932 if (req
->flags
& REQ_F_ISREG
) {
933 if (def
->hash_reg_file
)
936 if (def
->unbound_nonreg_file
)
937 req
->work
.flags
|= IO_WQ_WORK_UNBOUND
;
940 io_req_work_grab_env(req
, def
);
942 *link
= io_prep_linked_timeout(req
);
946 static inline void io_queue_async_work(struct io_kiocb
*req
)
948 struct io_ring_ctx
*ctx
= req
->ctx
;
949 struct io_kiocb
*link
;
952 do_hashed
= io_prep_async_work(req
, &link
);
954 trace_io_uring_queue_async_work(ctx
, do_hashed
, req
, &req
->work
,
957 io_wq_enqueue(ctx
->io_wq
, &req
->work
);
959 io_wq_enqueue_hashed(ctx
->io_wq
, &req
->work
,
960 file_inode(req
->file
));
964 io_queue_linked_timeout(link
);
967 static void io_kill_timeout(struct io_kiocb
*req
)
971 ret
= hrtimer_try_to_cancel(&req
->io
->timeout
.timer
);
973 atomic_inc(&req
->ctx
->cq_timeouts
);
974 list_del_init(&req
->list
);
975 io_cqring_fill_event(req
, 0);
980 static void io_kill_timeouts(struct io_ring_ctx
*ctx
)
982 struct io_kiocb
*req
, *tmp
;
984 spin_lock_irq(&ctx
->completion_lock
);
985 list_for_each_entry_safe(req
, tmp
, &ctx
->timeout_list
, list
)
986 io_kill_timeout(req
);
987 spin_unlock_irq(&ctx
->completion_lock
);
990 static void io_commit_cqring(struct io_ring_ctx
*ctx
)
992 struct io_kiocb
*req
;
994 while ((req
= io_get_timeout_req(ctx
)) != NULL
)
995 io_kill_timeout(req
);
997 __io_commit_cqring(ctx
);
999 while ((req
= io_get_deferred_req(ctx
)) != NULL
)
1000 io_queue_async_work(req
);
1003 static struct io_uring_cqe
*io_get_cqring(struct io_ring_ctx
*ctx
)
1005 struct io_rings
*rings
= ctx
->rings
;
1008 tail
= ctx
->cached_cq_tail
;
1010 * writes to the cq entry need to come after reading head; the
1011 * control dependency is enough as we're using WRITE_ONCE to
1014 if (tail
- READ_ONCE(rings
->cq
.head
) == rings
->cq_ring_entries
)
1017 ctx
->cached_cq_tail
++;
1018 return &rings
->cqes
[tail
& ctx
->cq_mask
];
1021 static inline bool io_should_trigger_evfd(struct io_ring_ctx
*ctx
)
1025 if (!ctx
->eventfd_async
)
1027 return io_wq_current_is_worker() || in_interrupt();
1030 static void __io_cqring_ev_posted(struct io_ring_ctx
*ctx
, bool trigger_ev
)
1032 if (waitqueue_active(&ctx
->wait
))
1033 wake_up(&ctx
->wait
);
1034 if (waitqueue_active(&ctx
->sqo_wait
))
1035 wake_up(&ctx
->sqo_wait
);
1037 eventfd_signal(ctx
->cq_ev_fd
, 1);
1040 static void io_cqring_ev_posted(struct io_ring_ctx
*ctx
)
1042 __io_cqring_ev_posted(ctx
, io_should_trigger_evfd(ctx
));
1045 /* Returns true if there are no backlogged entries after the flush */
1046 static bool io_cqring_overflow_flush(struct io_ring_ctx
*ctx
, bool force
)
1048 struct io_rings
*rings
= ctx
->rings
;
1049 struct io_uring_cqe
*cqe
;
1050 struct io_kiocb
*req
;
1051 unsigned long flags
;
1055 if (list_empty_careful(&ctx
->cq_overflow_list
))
1057 if ((ctx
->cached_cq_tail
- READ_ONCE(rings
->cq
.head
) ==
1058 rings
->cq_ring_entries
))
1062 spin_lock_irqsave(&ctx
->completion_lock
, flags
);
1064 /* if force is set, the ring is going away. always drop after that */
1066 ctx
->cq_overflow_flushed
= 1;
1069 while (!list_empty(&ctx
->cq_overflow_list
)) {
1070 cqe
= io_get_cqring(ctx
);
1074 req
= list_first_entry(&ctx
->cq_overflow_list
, struct io_kiocb
,
1076 list_move(&req
->list
, &list
);
1078 WRITE_ONCE(cqe
->user_data
, req
->user_data
);
1079 WRITE_ONCE(cqe
->res
, req
->result
);
1080 WRITE_ONCE(cqe
->flags
, 0);
1082 WRITE_ONCE(ctx
->rings
->cq_overflow
,
1083 atomic_inc_return(&ctx
->cached_cq_overflow
));
1087 io_commit_cqring(ctx
);
1089 clear_bit(0, &ctx
->sq_check_overflow
);
1090 clear_bit(0, &ctx
->cq_check_overflow
);
1092 spin_unlock_irqrestore(&ctx
->completion_lock
, flags
);
1093 io_cqring_ev_posted(ctx
);
1095 while (!list_empty(&list
)) {
1096 req
= list_first_entry(&list
, struct io_kiocb
, list
);
1097 list_del(&req
->list
);
1104 static void io_cqring_fill_event(struct io_kiocb
*req
, long res
)
1106 struct io_ring_ctx
*ctx
= req
->ctx
;
1107 struct io_uring_cqe
*cqe
;
1109 trace_io_uring_complete(ctx
, req
->user_data
, res
);
1112 * If we can't get a cq entry, userspace overflowed the
1113 * submission (by quite a lot). Increment the overflow count in
1116 cqe
= io_get_cqring(ctx
);
1118 WRITE_ONCE(cqe
->user_data
, req
->user_data
);
1119 WRITE_ONCE(cqe
->res
, res
);
1120 WRITE_ONCE(cqe
->flags
, 0);
1121 } else if (ctx
->cq_overflow_flushed
) {
1122 WRITE_ONCE(ctx
->rings
->cq_overflow
,
1123 atomic_inc_return(&ctx
->cached_cq_overflow
));
1125 if (list_empty(&ctx
->cq_overflow_list
)) {
1126 set_bit(0, &ctx
->sq_check_overflow
);
1127 set_bit(0, &ctx
->cq_check_overflow
);
1129 refcount_inc(&req
->refs
);
1131 list_add_tail(&req
->list
, &ctx
->cq_overflow_list
);
1135 static void io_cqring_add_event(struct io_kiocb
*req
, long res
)
1137 struct io_ring_ctx
*ctx
= req
->ctx
;
1138 unsigned long flags
;
1140 spin_lock_irqsave(&ctx
->completion_lock
, flags
);
1141 io_cqring_fill_event(req
, res
);
1142 io_commit_cqring(ctx
);
1143 spin_unlock_irqrestore(&ctx
->completion_lock
, flags
);
1145 io_cqring_ev_posted(ctx
);
1148 static inline bool io_is_fallback_req(struct io_kiocb
*req
)
1150 return req
== (struct io_kiocb
*)
1151 ((unsigned long) req
->ctx
->fallback_req
& ~1UL);
1154 static struct io_kiocb
*io_get_fallback_req(struct io_ring_ctx
*ctx
)
1156 struct io_kiocb
*req
;
1158 req
= ctx
->fallback_req
;
1159 if (!test_and_set_bit_lock(0, (unsigned long *) ctx
->fallback_req
))
1165 static struct io_kiocb
*io_get_req(struct io_ring_ctx
*ctx
,
1166 struct io_submit_state
*state
)
1168 gfp_t gfp
= GFP_KERNEL
| __GFP_NOWARN
;
1169 struct io_kiocb
*req
;
1172 req
= kmem_cache_alloc(req_cachep
, gfp
);
1175 } else if (!state
->free_reqs
) {
1179 sz
= min_t(size_t, state
->ios_left
, ARRAY_SIZE(state
->reqs
));
1180 ret
= kmem_cache_alloc_bulk(req_cachep
, gfp
, sz
, state
->reqs
);
1183 * Bulk alloc is all-or-nothing. If we fail to get a batch,
1184 * retry single alloc to be on the safe side.
1186 if (unlikely(ret
<= 0)) {
1187 state
->reqs
[0] = kmem_cache_alloc(req_cachep
, gfp
);
1188 if (!state
->reqs
[0])
1192 state
->free_reqs
= ret
- 1;
1193 req
= state
->reqs
[ret
- 1];
1196 req
= state
->reqs
[state
->free_reqs
];
1204 /* one is dropped after submission, the other at completion */
1205 refcount_set(&req
->refs
, 2);
1207 INIT_IO_WORK(&req
->work
, io_wq_submit_work
);
1210 req
= io_get_fallback_req(ctx
);
1213 percpu_ref_put(&ctx
->refs
);
1217 static void __io_req_do_free(struct io_kiocb
*req
)
1219 if (likely(!io_is_fallback_req(req
)))
1220 kmem_cache_free(req_cachep
, req
);
1222 clear_bit_unlock(0, (unsigned long *) req
->ctx
->fallback_req
);
1225 static void __io_req_aux_free(struct io_kiocb
*req
)
1227 struct io_ring_ctx
*ctx
= req
->ctx
;
1231 if (req
->flags
& REQ_F_FIXED_FILE
)
1232 percpu_ref_put(&ctx
->file_data
->refs
);
1237 io_req_work_drop_env(req
);
1240 static void __io_free_req(struct io_kiocb
*req
)
1242 __io_req_aux_free(req
);
1244 if (req
->flags
& REQ_F_INFLIGHT
) {
1245 struct io_ring_ctx
*ctx
= req
->ctx
;
1246 unsigned long flags
;
1248 spin_lock_irqsave(&ctx
->inflight_lock
, flags
);
1249 list_del(&req
->inflight_entry
);
1250 if (waitqueue_active(&ctx
->inflight_wait
))
1251 wake_up(&ctx
->inflight_wait
);
1252 spin_unlock_irqrestore(&ctx
->inflight_lock
, flags
);
1255 percpu_ref_put(&req
->ctx
->refs
);
1256 __io_req_do_free(req
);
1260 void *reqs
[IO_IOPOLL_BATCH
];
1265 static void io_free_req_many(struct io_ring_ctx
*ctx
, struct req_batch
*rb
)
1267 int fixed_refs
= rb
->to_free
;
1271 if (rb
->need_iter
) {
1272 int i
, inflight
= 0;
1273 unsigned long flags
;
1276 for (i
= 0; i
< rb
->to_free
; i
++) {
1277 struct io_kiocb
*req
= rb
->reqs
[i
];
1279 if (req
->flags
& REQ_F_FIXED_FILE
) {
1283 if (req
->flags
& REQ_F_INFLIGHT
)
1285 __io_req_aux_free(req
);
1290 spin_lock_irqsave(&ctx
->inflight_lock
, flags
);
1291 for (i
= 0; i
< rb
->to_free
; i
++) {
1292 struct io_kiocb
*req
= rb
->reqs
[i
];
1294 if (req
->flags
& REQ_F_INFLIGHT
) {
1295 list_del(&req
->inflight_entry
);
1300 spin_unlock_irqrestore(&ctx
->inflight_lock
, flags
);
1302 if (waitqueue_active(&ctx
->inflight_wait
))
1303 wake_up(&ctx
->inflight_wait
);
1306 kmem_cache_free_bulk(req_cachep
, rb
->to_free
, rb
->reqs
);
1308 percpu_ref_put_many(&ctx
->file_data
->refs
, fixed_refs
);
1309 percpu_ref_put_many(&ctx
->refs
, rb
->to_free
);
1310 rb
->to_free
= rb
->need_iter
= 0;
1313 static bool io_link_cancel_timeout(struct io_kiocb
*req
)
1315 struct io_ring_ctx
*ctx
= req
->ctx
;
1318 ret
= hrtimer_try_to_cancel(&req
->io
->timeout
.timer
);
1320 io_cqring_fill_event(req
, -ECANCELED
);
1321 io_commit_cqring(ctx
);
1322 req
->flags
&= ~REQ_F_LINK
;
1330 static void io_req_link_next(struct io_kiocb
*req
, struct io_kiocb
**nxtptr
)
1332 struct io_ring_ctx
*ctx
= req
->ctx
;
1333 bool wake_ev
= false;
1335 /* Already got next link */
1336 if (req
->flags
& REQ_F_LINK_NEXT
)
1340 * The list should never be empty when we are called here. But could
1341 * potentially happen if the chain is messed up, check to be on the
1344 while (!list_empty(&req
->link_list
)) {
1345 struct io_kiocb
*nxt
= list_first_entry(&req
->link_list
,
1346 struct io_kiocb
, link_list
);
1348 if (unlikely((req
->flags
& REQ_F_LINK_TIMEOUT
) &&
1349 (nxt
->flags
& REQ_F_TIMEOUT
))) {
1350 list_del_init(&nxt
->link_list
);
1351 wake_ev
|= io_link_cancel_timeout(nxt
);
1352 req
->flags
&= ~REQ_F_LINK_TIMEOUT
;
1356 list_del_init(&req
->link_list
);
1357 if (!list_empty(&nxt
->link_list
))
1358 nxt
->flags
|= REQ_F_LINK
;
1363 req
->flags
|= REQ_F_LINK_NEXT
;
1365 io_cqring_ev_posted(ctx
);
1369 * Called if REQ_F_LINK is set, and we fail the head request
1371 static void io_fail_links(struct io_kiocb
*req
)
1373 struct io_ring_ctx
*ctx
= req
->ctx
;
1374 unsigned long flags
;
1376 spin_lock_irqsave(&ctx
->completion_lock
, flags
);
1378 while (!list_empty(&req
->link_list
)) {
1379 struct io_kiocb
*link
= list_first_entry(&req
->link_list
,
1380 struct io_kiocb
, link_list
);
1382 list_del_init(&link
->link_list
);
1383 trace_io_uring_fail_link(req
, link
);
1385 if ((req
->flags
& REQ_F_LINK_TIMEOUT
) &&
1386 link
->opcode
== IORING_OP_LINK_TIMEOUT
) {
1387 io_link_cancel_timeout(link
);
1389 io_cqring_fill_event(link
, -ECANCELED
);
1390 __io_double_put_req(link
);
1392 req
->flags
&= ~REQ_F_LINK_TIMEOUT
;
1395 io_commit_cqring(ctx
);
1396 spin_unlock_irqrestore(&ctx
->completion_lock
, flags
);
1397 io_cqring_ev_posted(ctx
);
1400 static void io_req_find_next(struct io_kiocb
*req
, struct io_kiocb
**nxt
)
1402 if (likely(!(req
->flags
& REQ_F_LINK
)))
1406 * If LINK is set, we have dependent requests in this chain. If we
1407 * didn't fail this request, queue the first one up, moving any other
1408 * dependencies to the next request. In case of failure, fail the rest
1411 if (req
->flags
& REQ_F_FAIL_LINK
) {
1413 } else if ((req
->flags
& (REQ_F_LINK_TIMEOUT
| REQ_F_COMP_LOCKED
)) ==
1414 REQ_F_LINK_TIMEOUT
) {
1415 struct io_ring_ctx
*ctx
= req
->ctx
;
1416 unsigned long flags
;
1419 * If this is a timeout link, we could be racing with the
1420 * timeout timer. Grab the completion lock for this case to
1421 * protect against that.
1423 spin_lock_irqsave(&ctx
->completion_lock
, flags
);
1424 io_req_link_next(req
, nxt
);
1425 spin_unlock_irqrestore(&ctx
->completion_lock
, flags
);
1427 io_req_link_next(req
, nxt
);
1431 static void io_free_req(struct io_kiocb
*req
)
1433 struct io_kiocb
*nxt
= NULL
;
1435 io_req_find_next(req
, &nxt
);
1439 io_queue_async_work(nxt
);
1443 * Drop reference to request, return next in chain (if there is one) if this
1444 * was the last reference to this request.
1446 __attribute__((nonnull
))
1447 static void io_put_req_find_next(struct io_kiocb
*req
, struct io_kiocb
**nxtptr
)
1449 io_req_find_next(req
, nxtptr
);
1451 if (refcount_dec_and_test(&req
->refs
))
1455 static void io_put_req(struct io_kiocb
*req
)
1457 if (refcount_dec_and_test(&req
->refs
))
1462 * Must only be used if we don't need to care about links, usually from
1463 * within the completion handling itself.
1465 static void __io_double_put_req(struct io_kiocb
*req
)
1467 /* drop both submit and complete references */
1468 if (refcount_sub_and_test(2, &req
->refs
))
1472 static void io_double_put_req(struct io_kiocb
*req
)
1474 /* drop both submit and complete references */
1475 if (refcount_sub_and_test(2, &req
->refs
))
1479 static unsigned io_cqring_events(struct io_ring_ctx
*ctx
, bool noflush
)
1481 struct io_rings
*rings
= ctx
->rings
;
1483 if (test_bit(0, &ctx
->cq_check_overflow
)) {
1485 * noflush == true is from the waitqueue handler, just ensure
1486 * we wake up the task, and the next invocation will flush the
1487 * entries. We cannot safely to it from here.
1489 if (noflush
&& !list_empty(&ctx
->cq_overflow_list
))
1492 io_cqring_overflow_flush(ctx
, false);
1495 /* See comment at the top of this file */
1497 return ctx
->cached_cq_tail
- READ_ONCE(rings
->cq
.head
);
1500 static inline unsigned int io_sqring_entries(struct io_ring_ctx
*ctx
)
1502 struct io_rings
*rings
= ctx
->rings
;
1504 /* make sure SQ entry isn't read before tail */
1505 return smp_load_acquire(&rings
->sq
.tail
) - ctx
->cached_sq_head
;
1508 static inline bool io_req_multi_free(struct req_batch
*rb
, struct io_kiocb
*req
)
1510 if ((req
->flags
& REQ_F_LINK
) || io_is_fallback_req(req
))
1513 if (!(req
->flags
& REQ_F_FIXED_FILE
) || req
->io
)
1516 rb
->reqs
[rb
->to_free
++] = req
;
1517 if (unlikely(rb
->to_free
== ARRAY_SIZE(rb
->reqs
)))
1518 io_free_req_many(req
->ctx
, rb
);
1523 * Find and free completed poll iocbs
1525 static void io_iopoll_complete(struct io_ring_ctx
*ctx
, unsigned int *nr_events
,
1526 struct list_head
*done
)
1528 struct req_batch rb
;
1529 struct io_kiocb
*req
;
1531 rb
.to_free
= rb
.need_iter
= 0;
1532 while (!list_empty(done
)) {
1533 req
= list_first_entry(done
, struct io_kiocb
, list
);
1534 list_del(&req
->list
);
1536 io_cqring_fill_event(req
, req
->result
);
1539 if (refcount_dec_and_test(&req
->refs
) &&
1540 !io_req_multi_free(&rb
, req
))
1544 io_commit_cqring(ctx
);
1545 io_free_req_many(ctx
, &rb
);
1548 static int io_do_iopoll(struct io_ring_ctx
*ctx
, unsigned int *nr_events
,
1551 struct io_kiocb
*req
, *tmp
;
1557 * Only spin for completions if we don't have multiple devices hanging
1558 * off our complete list, and we're under the requested amount.
1560 spin
= !ctx
->poll_multi_file
&& *nr_events
< min
;
1563 list_for_each_entry_safe(req
, tmp
, &ctx
->poll_list
, list
) {
1564 struct kiocb
*kiocb
= &req
->rw
.kiocb
;
1567 * Move completed entries to our local list. If we find a
1568 * request that requires polling, break out and complete
1569 * the done list first, if we have entries there.
1571 if (req
->flags
& REQ_F_IOPOLL_COMPLETED
) {
1572 list_move_tail(&req
->list
, &done
);
1575 if (!list_empty(&done
))
1578 ret
= kiocb
->ki_filp
->f_op
->iopoll(kiocb
, spin
);
1587 if (!list_empty(&done
))
1588 io_iopoll_complete(ctx
, nr_events
, &done
);
1594 * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a
1595 * non-spinning poll check - we'll still enter the driver poll loop, but only
1596 * as a non-spinning completion check.
1598 static int io_iopoll_getevents(struct io_ring_ctx
*ctx
, unsigned int *nr_events
,
1601 while (!list_empty(&ctx
->poll_list
) && !need_resched()) {
1604 ret
= io_do_iopoll(ctx
, nr_events
, min
);
1607 if (!min
|| *nr_events
>= min
)
1615 * We can't just wait for polled events to come to us, we have to actively
1616 * find and complete them.
1618 static void io_iopoll_reap_events(struct io_ring_ctx
*ctx
)
1620 if (!(ctx
->flags
& IORING_SETUP_IOPOLL
))
1623 mutex_lock(&ctx
->uring_lock
);
1624 while (!list_empty(&ctx
->poll_list
)) {
1625 unsigned int nr_events
= 0;
1627 io_iopoll_getevents(ctx
, &nr_events
, 1);
1630 * Ensure we allow local-to-the-cpu processing to take place,
1631 * in this case we need to ensure that we reap all events.
1635 mutex_unlock(&ctx
->uring_lock
);
1638 static int __io_iopoll_check(struct io_ring_ctx
*ctx
, unsigned *nr_events
,
1641 int iters
= 0, ret
= 0;
1647 * Don't enter poll loop if we already have events pending.
1648 * If we do, we can potentially be spinning for commands that
1649 * already triggered a CQE (eg in error).
1651 if (io_cqring_events(ctx
, false))
1655 * If a submit got punted to a workqueue, we can have the
1656 * application entering polling for a command before it gets
1657 * issued. That app will hold the uring_lock for the duration
1658 * of the poll right here, so we need to take a breather every
1659 * now and then to ensure that the issue has a chance to add
1660 * the poll to the issued list. Otherwise we can spin here
1661 * forever, while the workqueue is stuck trying to acquire the
1664 if (!(++iters
& 7)) {
1665 mutex_unlock(&ctx
->uring_lock
);
1666 mutex_lock(&ctx
->uring_lock
);
1669 if (*nr_events
< min
)
1670 tmin
= min
- *nr_events
;
1672 ret
= io_iopoll_getevents(ctx
, nr_events
, tmin
);
1676 } while (min
&& !*nr_events
&& !need_resched());
1681 static int io_iopoll_check(struct io_ring_ctx
*ctx
, unsigned *nr_events
,
1687 * We disallow the app entering submit/complete with polling, but we
1688 * still need to lock the ring to prevent racing with polled issue
1689 * that got punted to a workqueue.
1691 mutex_lock(&ctx
->uring_lock
);
1692 ret
= __io_iopoll_check(ctx
, nr_events
, min
);
1693 mutex_unlock(&ctx
->uring_lock
);
1697 static void kiocb_end_write(struct io_kiocb
*req
)
1700 * Tell lockdep we inherited freeze protection from submission
1703 if (req
->flags
& REQ_F_ISREG
) {
1704 struct inode
*inode
= file_inode(req
->file
);
1706 __sb_writers_acquired(inode
->i_sb
, SB_FREEZE_WRITE
);
1708 file_end_write(req
->file
);
1711 static inline void req_set_fail_links(struct io_kiocb
*req
)
1713 if ((req
->flags
& (REQ_F_LINK
| REQ_F_HARDLINK
)) == REQ_F_LINK
)
1714 req
->flags
|= REQ_F_FAIL_LINK
;
1717 static void io_complete_rw_common(struct kiocb
*kiocb
, long res
)
1719 struct io_kiocb
*req
= container_of(kiocb
, struct io_kiocb
, rw
.kiocb
);
1721 if (kiocb
->ki_flags
& IOCB_WRITE
)
1722 kiocb_end_write(req
);
1724 if (res
!= req
->result
)
1725 req_set_fail_links(req
);
1726 io_cqring_add_event(req
, res
);
1729 static void io_complete_rw(struct kiocb
*kiocb
, long res
, long res2
)
1731 struct io_kiocb
*req
= container_of(kiocb
, struct io_kiocb
, rw
.kiocb
);
1733 io_complete_rw_common(kiocb
, res
);
1737 static struct io_kiocb
*__io_complete_rw(struct kiocb
*kiocb
, long res
)
1739 struct io_kiocb
*req
= container_of(kiocb
, struct io_kiocb
, rw
.kiocb
);
1740 struct io_kiocb
*nxt
= NULL
;
1742 io_complete_rw_common(kiocb
, res
);
1743 io_put_req_find_next(req
, &nxt
);
1748 static void io_complete_rw_iopoll(struct kiocb
*kiocb
, long res
, long res2
)
1750 struct io_kiocb
*req
= container_of(kiocb
, struct io_kiocb
, rw
.kiocb
);
1752 if (kiocb
->ki_flags
& IOCB_WRITE
)
1753 kiocb_end_write(req
);
1755 if (res
!= req
->result
)
1756 req_set_fail_links(req
);
1759 req
->flags
|= REQ_F_IOPOLL_COMPLETED
;
1763 * After the iocb has been issued, it's safe to be found on the poll list.
1764 * Adding the kiocb to the list AFTER submission ensures that we don't
1765 * find it from a io_iopoll_getevents() thread before the issuer is done
1766 * accessing the kiocb cookie.
1768 static void io_iopoll_req_issued(struct io_kiocb
*req
)
1770 struct io_ring_ctx
*ctx
= req
->ctx
;
1773 * Track whether we have multiple files in our lists. This will impact
1774 * how we do polling eventually, not spinning if we're on potentially
1775 * different devices.
1777 if (list_empty(&ctx
->poll_list
)) {
1778 ctx
->poll_multi_file
= false;
1779 } else if (!ctx
->poll_multi_file
) {
1780 struct io_kiocb
*list_req
;
1782 list_req
= list_first_entry(&ctx
->poll_list
, struct io_kiocb
,
1784 if (list_req
->file
!= req
->file
)
1785 ctx
->poll_multi_file
= true;
1789 * For fast devices, IO may have already completed. If it has, add
1790 * it to the front so we find it first.
1792 if (req
->flags
& REQ_F_IOPOLL_COMPLETED
)
1793 list_add(&req
->list
, &ctx
->poll_list
);
1795 list_add_tail(&req
->list
, &ctx
->poll_list
);
1798 static void io_file_put(struct io_submit_state
*state
)
1801 int diff
= state
->has_refs
- state
->used_refs
;
1804 fput_many(state
->file
, diff
);
1810 * Get as many references to a file as we have IOs left in this submission,
1811 * assuming most submissions are for one file, or at least that each file
1812 * has more than one submission.
1814 static struct file
*io_file_get(struct io_submit_state
*state
, int fd
)
1820 if (state
->fd
== fd
) {
1827 state
->file
= fget_many(fd
, state
->ios_left
);
1832 state
->has_refs
= state
->ios_left
;
1833 state
->used_refs
= 1;
1839 * If we tracked the file through the SCM inflight mechanism, we could support
1840 * any file. For now, just ensure that anything potentially problematic is done
1843 static bool io_file_supports_async(struct file
*file
)
1845 umode_t mode
= file_inode(file
)->i_mode
;
1847 if (S_ISBLK(mode
) || S_ISCHR(mode
) || S_ISSOCK(mode
))
1849 if (S_ISREG(mode
) && file
->f_op
!= &io_uring_fops
)
1855 static int io_prep_rw(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
,
1856 bool force_nonblock
)
1858 struct io_ring_ctx
*ctx
= req
->ctx
;
1859 struct kiocb
*kiocb
= &req
->rw
.kiocb
;
1863 if (S_ISREG(file_inode(req
->file
)->i_mode
))
1864 req
->flags
|= REQ_F_ISREG
;
1866 kiocb
->ki_pos
= READ_ONCE(sqe
->off
);
1867 if (kiocb
->ki_pos
== -1 && !(req
->file
->f_mode
& FMODE_STREAM
)) {
1868 req
->flags
|= REQ_F_CUR_POS
;
1869 kiocb
->ki_pos
= req
->file
->f_pos
;
1871 kiocb
->ki_hint
= ki_hint_validate(file_write_hint(kiocb
->ki_filp
));
1872 kiocb
->ki_flags
= iocb_flags(kiocb
->ki_filp
);
1873 ret
= kiocb_set_rw_flags(kiocb
, READ_ONCE(sqe
->rw_flags
));
1877 ioprio
= READ_ONCE(sqe
->ioprio
);
1879 ret
= ioprio_check_cap(ioprio
);
1883 kiocb
->ki_ioprio
= ioprio
;
1885 kiocb
->ki_ioprio
= get_current_ioprio();
1887 /* don't allow async punt if RWF_NOWAIT was requested */
1888 if ((kiocb
->ki_flags
& IOCB_NOWAIT
) ||
1889 (req
->file
->f_flags
& O_NONBLOCK
))
1890 req
->flags
|= REQ_F_NOWAIT
;
1893 kiocb
->ki_flags
|= IOCB_NOWAIT
;
1895 if (ctx
->flags
& IORING_SETUP_IOPOLL
) {
1896 if (!(kiocb
->ki_flags
& IOCB_DIRECT
) ||
1897 !kiocb
->ki_filp
->f_op
->iopoll
)
1900 kiocb
->ki_flags
|= IOCB_HIPRI
;
1901 kiocb
->ki_complete
= io_complete_rw_iopoll
;
1904 if (kiocb
->ki_flags
& IOCB_HIPRI
)
1906 kiocb
->ki_complete
= io_complete_rw
;
1909 req
->rw
.addr
= READ_ONCE(sqe
->addr
);
1910 req
->rw
.len
= READ_ONCE(sqe
->len
);
1911 /* we own ->private, reuse it for the buffer index */
1912 req
->rw
.kiocb
.private = (void *) (unsigned long)
1913 READ_ONCE(sqe
->buf_index
);
1917 static inline void io_rw_done(struct kiocb
*kiocb
, ssize_t ret
)
1923 case -ERESTARTNOINTR
:
1924 case -ERESTARTNOHAND
:
1925 case -ERESTART_RESTARTBLOCK
:
1927 * We can't just restart the syscall, since previously
1928 * submitted sqes may already be in progress. Just fail this
1934 kiocb
->ki_complete(kiocb
, ret
, 0);
1938 static void kiocb_done(struct kiocb
*kiocb
, ssize_t ret
, struct io_kiocb
**nxt
,
1941 struct io_kiocb
*req
= container_of(kiocb
, struct io_kiocb
, rw
.kiocb
);
1943 if (req
->flags
& REQ_F_CUR_POS
)
1944 req
->file
->f_pos
= kiocb
->ki_pos
;
1945 if (in_async
&& ret
>= 0 && kiocb
->ki_complete
== io_complete_rw
)
1946 *nxt
= __io_complete_rw(kiocb
, ret
);
1948 io_rw_done(kiocb
, ret
);
1951 static ssize_t
io_import_fixed(struct io_kiocb
*req
, int rw
,
1952 struct iov_iter
*iter
)
1954 struct io_ring_ctx
*ctx
= req
->ctx
;
1955 size_t len
= req
->rw
.len
;
1956 struct io_mapped_ubuf
*imu
;
1957 unsigned index
, buf_index
;
1961 /* attempt to use fixed buffers without having provided iovecs */
1962 if (unlikely(!ctx
->user_bufs
))
1965 buf_index
= (unsigned long) req
->rw
.kiocb
.private;
1966 if (unlikely(buf_index
>= ctx
->nr_user_bufs
))
1969 index
= array_index_nospec(buf_index
, ctx
->nr_user_bufs
);
1970 imu
= &ctx
->user_bufs
[index
];
1971 buf_addr
= req
->rw
.addr
;
1974 if (buf_addr
+ len
< buf_addr
)
1976 /* not inside the mapped region */
1977 if (buf_addr
< imu
->ubuf
|| buf_addr
+ len
> imu
->ubuf
+ imu
->len
)
1981 * May not be a start of buffer, set size appropriately
1982 * and advance us to the beginning.
1984 offset
= buf_addr
- imu
->ubuf
;
1985 iov_iter_bvec(iter
, rw
, imu
->bvec
, imu
->nr_bvecs
, offset
+ len
);
1989 * Don't use iov_iter_advance() here, as it's really slow for
1990 * using the latter parts of a big fixed buffer - it iterates
1991 * over each segment manually. We can cheat a bit here, because
1994 * 1) it's a BVEC iter, we set it up
1995 * 2) all bvecs are PAGE_SIZE in size, except potentially the
1996 * first and last bvec
1998 * So just find our index, and adjust the iterator afterwards.
1999 * If the offset is within the first bvec (or the whole first
2000 * bvec, just use iov_iter_advance(). This makes it easier
2001 * since we can just skip the first segment, which may not
2002 * be PAGE_SIZE aligned.
2004 const struct bio_vec
*bvec
= imu
->bvec
;
2006 if (offset
<= bvec
->bv_len
) {
2007 iov_iter_advance(iter
, offset
);
2009 unsigned long seg_skip
;
2011 /* skip first vec */
2012 offset
-= bvec
->bv_len
;
2013 seg_skip
= 1 + (offset
>> PAGE_SHIFT
);
2015 iter
->bvec
= bvec
+ seg_skip
;
2016 iter
->nr_segs
-= seg_skip
;
2017 iter
->count
-= bvec
->bv_len
+ offset
;
2018 iter
->iov_offset
= offset
& ~PAGE_MASK
;
2025 static ssize_t
io_import_iovec(int rw
, struct io_kiocb
*req
,
2026 struct iovec
**iovec
, struct iov_iter
*iter
)
2028 void __user
*buf
= u64_to_user_ptr(req
->rw
.addr
);
2029 size_t sqe_len
= req
->rw
.len
;
2032 opcode
= req
->opcode
;
2033 if (opcode
== IORING_OP_READ_FIXED
|| opcode
== IORING_OP_WRITE_FIXED
) {
2035 return io_import_fixed(req
, rw
, iter
);
2038 /* buffer index only valid with fixed read/write */
2039 if (req
->rw
.kiocb
.private)
2042 if (opcode
== IORING_OP_READ
|| opcode
== IORING_OP_WRITE
) {
2044 ret
= import_single_range(rw
, buf
, sqe_len
, *iovec
, iter
);
2050 struct io_async_rw
*iorw
= &req
->io
->rw
;
2053 iov_iter_init(iter
, rw
, *iovec
, iorw
->nr_segs
, iorw
->size
);
2054 if (iorw
->iov
== iorw
->fast_iov
)
2062 #ifdef CONFIG_COMPAT
2063 if (req
->ctx
->compat
)
2064 return compat_import_iovec(rw
, buf
, sqe_len
, UIO_FASTIOV
,
2068 return import_iovec(rw
, buf
, sqe_len
, UIO_FASTIOV
, iovec
, iter
);
2072 * For files that don't have ->read_iter() and ->write_iter(), handle them
2073 * by looping over ->read() or ->write() manually.
2075 static ssize_t
loop_rw_iter(int rw
, struct file
*file
, struct kiocb
*kiocb
,
2076 struct iov_iter
*iter
)
2081 * Don't support polled IO through this interface, and we can't
2082 * support non-blocking either. For the latter, this just causes
2083 * the kiocb to be handled from an async context.
2085 if (kiocb
->ki_flags
& IOCB_HIPRI
)
2087 if (kiocb
->ki_flags
& IOCB_NOWAIT
)
2090 while (iov_iter_count(iter
)) {
2094 if (!iov_iter_is_bvec(iter
)) {
2095 iovec
= iov_iter_iovec(iter
);
2097 /* fixed buffers import bvec */
2098 iovec
.iov_base
= kmap(iter
->bvec
->bv_page
)
2100 iovec
.iov_len
= min(iter
->count
,
2101 iter
->bvec
->bv_len
- iter
->iov_offset
);
2105 nr
= file
->f_op
->read(file
, iovec
.iov_base
,
2106 iovec
.iov_len
, &kiocb
->ki_pos
);
2108 nr
= file
->f_op
->write(file
, iovec
.iov_base
,
2109 iovec
.iov_len
, &kiocb
->ki_pos
);
2112 if (iov_iter_is_bvec(iter
))
2113 kunmap(iter
->bvec
->bv_page
);
2121 if (nr
!= iovec
.iov_len
)
2123 iov_iter_advance(iter
, nr
);
2129 static void io_req_map_rw(struct io_kiocb
*req
, ssize_t io_size
,
2130 struct iovec
*iovec
, struct iovec
*fast_iov
,
2131 struct iov_iter
*iter
)
2133 req
->io
->rw
.nr_segs
= iter
->nr_segs
;
2134 req
->io
->rw
.size
= io_size
;
2135 req
->io
->rw
.iov
= iovec
;
2136 if (!req
->io
->rw
.iov
) {
2137 req
->io
->rw
.iov
= req
->io
->rw
.fast_iov
;
2138 memcpy(req
->io
->rw
.iov
, fast_iov
,
2139 sizeof(struct iovec
) * iter
->nr_segs
);
2143 static int io_alloc_async_ctx(struct io_kiocb
*req
)
2145 if (!io_op_defs
[req
->opcode
].async_ctx
)
2147 req
->io
= kmalloc(sizeof(*req
->io
), GFP_KERNEL
);
2148 return req
->io
== NULL
;
2151 static void io_rw_async(struct io_wq_work
**workptr
)
2153 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
2154 struct iovec
*iov
= NULL
;
2156 if (req
->io
->rw
.iov
!= req
->io
->rw
.fast_iov
)
2157 iov
= req
->io
->rw
.iov
;
2158 io_wq_submit_work(workptr
);
2162 static int io_setup_async_rw(struct io_kiocb
*req
, ssize_t io_size
,
2163 struct iovec
*iovec
, struct iovec
*fast_iov
,
2164 struct iov_iter
*iter
)
2166 if (!io_op_defs
[req
->opcode
].async_ctx
)
2169 if (io_alloc_async_ctx(req
))
2172 io_req_map_rw(req
, io_size
, iovec
, fast_iov
, iter
);
2174 req
->work
.func
= io_rw_async
;
2178 static int io_read_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
,
2179 bool force_nonblock
)
2181 struct io_async_ctx
*io
;
2182 struct iov_iter iter
;
2185 ret
= io_prep_rw(req
, sqe
, force_nonblock
);
2189 if (unlikely(!(req
->file
->f_mode
& FMODE_READ
)))
2196 io
->rw
.iov
= io
->rw
.fast_iov
;
2198 ret
= io_import_iovec(READ
, req
, &io
->rw
.iov
, &iter
);
2203 io_req_map_rw(req
, ret
, io
->rw
.iov
, io
->rw
.fast_iov
, &iter
);
2207 static int io_read(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2208 bool force_nonblock
)
2210 struct iovec inline_vecs
[UIO_FASTIOV
], *iovec
= inline_vecs
;
2211 struct kiocb
*kiocb
= &req
->rw
.kiocb
;
2212 struct iov_iter iter
;
2214 ssize_t io_size
, ret
;
2216 ret
= io_import_iovec(READ
, req
, &iovec
, &iter
);
2220 /* Ensure we clear previously set non-block flag */
2221 if (!force_nonblock
)
2222 req
->rw
.kiocb
.ki_flags
&= ~IOCB_NOWAIT
;
2226 if (req
->flags
& REQ_F_LINK
)
2227 req
->result
= io_size
;
2230 * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
2231 * we know to async punt it even if it was opened O_NONBLOCK
2233 if (force_nonblock
&& !io_file_supports_async(req
->file
)) {
2234 req
->flags
|= REQ_F_MUST_PUNT
;
2238 iov_count
= iov_iter_count(&iter
);
2239 ret
= rw_verify_area(READ
, req
->file
, &kiocb
->ki_pos
, iov_count
);
2243 if (req
->file
->f_op
->read_iter
)
2244 ret2
= call_read_iter(req
->file
, kiocb
, &iter
);
2246 ret2
= loop_rw_iter(READ
, req
->file
, kiocb
, &iter
);
2248 /* Catch -EAGAIN return for forced non-blocking submission */
2249 if (!force_nonblock
|| ret2
!= -EAGAIN
) {
2250 kiocb_done(kiocb
, ret2
, nxt
, req
->in_async
);
2253 ret
= io_setup_async_rw(req
, io_size
, iovec
,
2254 inline_vecs
, &iter
);
2261 if (!io_wq_current_is_worker())
2266 static int io_write_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
,
2267 bool force_nonblock
)
2269 struct io_async_ctx
*io
;
2270 struct iov_iter iter
;
2273 ret
= io_prep_rw(req
, sqe
, force_nonblock
);
2277 if (unlikely(!(req
->file
->f_mode
& FMODE_WRITE
)))
2284 io
->rw
.iov
= io
->rw
.fast_iov
;
2286 ret
= io_import_iovec(WRITE
, req
, &io
->rw
.iov
, &iter
);
2291 io_req_map_rw(req
, ret
, io
->rw
.iov
, io
->rw
.fast_iov
, &iter
);
2295 static int io_write(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2296 bool force_nonblock
)
2298 struct iovec inline_vecs
[UIO_FASTIOV
], *iovec
= inline_vecs
;
2299 struct kiocb
*kiocb
= &req
->rw
.kiocb
;
2300 struct iov_iter iter
;
2302 ssize_t ret
, io_size
;
2304 ret
= io_import_iovec(WRITE
, req
, &iovec
, &iter
);
2308 /* Ensure we clear previously set non-block flag */
2309 if (!force_nonblock
)
2310 req
->rw
.kiocb
.ki_flags
&= ~IOCB_NOWAIT
;
2314 if (req
->flags
& REQ_F_LINK
)
2315 req
->result
= io_size
;
2318 * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so
2319 * we know to async punt it even if it was opened O_NONBLOCK
2321 if (force_nonblock
&& !io_file_supports_async(req
->file
)) {
2322 req
->flags
|= REQ_F_MUST_PUNT
;
2326 /* file path doesn't support NOWAIT for non-direct_IO */
2327 if (force_nonblock
&& !(kiocb
->ki_flags
& IOCB_DIRECT
) &&
2328 (req
->flags
& REQ_F_ISREG
))
2331 iov_count
= iov_iter_count(&iter
);
2332 ret
= rw_verify_area(WRITE
, req
->file
, &kiocb
->ki_pos
, iov_count
);
2337 * Open-code file_start_write here to grab freeze protection,
2338 * which will be released by another thread in
2339 * io_complete_rw(). Fool lockdep by telling it the lock got
2340 * released so that it doesn't complain about the held lock when
2341 * we return to userspace.
2343 if (req
->flags
& REQ_F_ISREG
) {
2344 __sb_start_write(file_inode(req
->file
)->i_sb
,
2345 SB_FREEZE_WRITE
, true);
2346 __sb_writers_release(file_inode(req
->file
)->i_sb
,
2349 kiocb
->ki_flags
|= IOCB_WRITE
;
2351 if (req
->file
->f_op
->write_iter
)
2352 ret2
= call_write_iter(req
->file
, kiocb
, &iter
);
2354 ret2
= loop_rw_iter(WRITE
, req
->file
, kiocb
, &iter
);
2355 if (!force_nonblock
|| ret2
!= -EAGAIN
) {
2356 kiocb_done(kiocb
, ret2
, nxt
, req
->in_async
);
2359 ret
= io_setup_async_rw(req
, io_size
, iovec
,
2360 inline_vecs
, &iter
);
2367 if (!io_wq_current_is_worker())
2373 * IORING_OP_NOP just posts a completion event, nothing else.
2375 static int io_nop(struct io_kiocb
*req
)
2377 struct io_ring_ctx
*ctx
= req
->ctx
;
2379 if (unlikely(ctx
->flags
& IORING_SETUP_IOPOLL
))
2382 io_cqring_add_event(req
, 0);
2387 static int io_prep_fsync(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2389 struct io_ring_ctx
*ctx
= req
->ctx
;
2394 if (unlikely(ctx
->flags
& IORING_SETUP_IOPOLL
))
2396 if (unlikely(sqe
->addr
|| sqe
->ioprio
|| sqe
->buf_index
))
2399 req
->sync
.flags
= READ_ONCE(sqe
->fsync_flags
);
2400 if (unlikely(req
->sync
.flags
& ~IORING_FSYNC_DATASYNC
))
2403 req
->sync
.off
= READ_ONCE(sqe
->off
);
2404 req
->sync
.len
= READ_ONCE(sqe
->len
);
2408 static bool io_req_cancelled(struct io_kiocb
*req
)
2410 if (req
->work
.flags
& IO_WQ_WORK_CANCEL
) {
2411 req_set_fail_links(req
);
2412 io_cqring_add_event(req
, -ECANCELED
);
2420 static void io_link_work_cb(struct io_wq_work
**workptr
)
2422 struct io_wq_work
*work
= *workptr
;
2423 struct io_kiocb
*link
= work
->data
;
2425 io_queue_linked_timeout(link
);
2426 work
->func
= io_wq_submit_work
;
2429 static void io_wq_assign_next(struct io_wq_work
**workptr
, struct io_kiocb
*nxt
)
2431 struct io_kiocb
*link
;
2433 io_prep_async_work(nxt
, &link
);
2434 *workptr
= &nxt
->work
;
2436 nxt
->work
.flags
|= IO_WQ_WORK_CB
;
2437 nxt
->work
.func
= io_link_work_cb
;
2438 nxt
->work
.data
= link
;
2442 static void io_fsync_finish(struct io_wq_work
**workptr
)
2444 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
2445 loff_t end
= req
->sync
.off
+ req
->sync
.len
;
2446 struct io_kiocb
*nxt
= NULL
;
2449 if (io_req_cancelled(req
))
2452 ret
= vfs_fsync_range(req
->file
, req
->sync
.off
,
2453 end
> 0 ? end
: LLONG_MAX
,
2454 req
->sync
.flags
& IORING_FSYNC_DATASYNC
);
2456 req_set_fail_links(req
);
2457 io_cqring_add_event(req
, ret
);
2458 io_put_req_find_next(req
, &nxt
);
2460 io_wq_assign_next(workptr
, nxt
);
2463 static int io_fsync(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2464 bool force_nonblock
)
2466 struct io_wq_work
*work
, *old_work
;
2468 /* fsync always requires a blocking context */
2469 if (force_nonblock
) {
2471 req
->work
.func
= io_fsync_finish
;
2475 work
= old_work
= &req
->work
;
2476 io_fsync_finish(&work
);
2477 if (work
&& work
!= old_work
)
2478 *nxt
= container_of(work
, struct io_kiocb
, work
);
2482 static void io_fallocate_finish(struct io_wq_work
**workptr
)
2484 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
2485 struct io_kiocb
*nxt
= NULL
;
2488 ret
= vfs_fallocate(req
->file
, req
->sync
.mode
, req
->sync
.off
,
2491 req_set_fail_links(req
);
2492 io_cqring_add_event(req
, ret
);
2493 io_put_req_find_next(req
, &nxt
);
2495 io_wq_assign_next(workptr
, nxt
);
2498 static int io_fallocate_prep(struct io_kiocb
*req
,
2499 const struct io_uring_sqe
*sqe
)
2501 if (sqe
->ioprio
|| sqe
->buf_index
|| sqe
->rw_flags
)
2504 req
->sync
.off
= READ_ONCE(sqe
->off
);
2505 req
->sync
.len
= READ_ONCE(sqe
->addr
);
2506 req
->sync
.mode
= READ_ONCE(sqe
->len
);
2510 static int io_fallocate(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2511 bool force_nonblock
)
2513 struct io_wq_work
*work
, *old_work
;
2515 /* fallocate always requiring blocking context */
2516 if (force_nonblock
) {
2518 req
->work
.func
= io_fallocate_finish
;
2522 work
= old_work
= &req
->work
;
2523 io_fallocate_finish(&work
);
2524 if (work
&& work
!= old_work
)
2525 *nxt
= container_of(work
, struct io_kiocb
, work
);
2530 static int io_openat_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2532 const char __user
*fname
;
2535 if (sqe
->ioprio
|| sqe
->buf_index
)
2538 req
->open
.dfd
= READ_ONCE(sqe
->fd
);
2539 req
->open
.how
.mode
= READ_ONCE(sqe
->len
);
2540 fname
= u64_to_user_ptr(READ_ONCE(sqe
->addr
));
2541 req
->open
.how
.flags
= READ_ONCE(sqe
->open_flags
);
2543 req
->open
.filename
= getname(fname
);
2544 if (IS_ERR(req
->open
.filename
)) {
2545 ret
= PTR_ERR(req
->open
.filename
);
2546 req
->open
.filename
= NULL
;
2553 static int io_openat2_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2555 struct open_how __user
*how
;
2556 const char __user
*fname
;
2560 if (sqe
->ioprio
|| sqe
->buf_index
)
2563 req
->open
.dfd
= READ_ONCE(sqe
->fd
);
2564 fname
= u64_to_user_ptr(READ_ONCE(sqe
->addr
));
2565 how
= u64_to_user_ptr(READ_ONCE(sqe
->addr2
));
2566 len
= READ_ONCE(sqe
->len
);
2568 if (len
< OPEN_HOW_SIZE_VER0
)
2571 ret
= copy_struct_from_user(&req
->open
.how
, sizeof(req
->open
.how
), how
,
2576 if (!(req
->open
.how
.flags
& O_PATH
) && force_o_largefile())
2577 req
->open
.how
.flags
|= O_LARGEFILE
;
2579 req
->open
.filename
= getname(fname
);
2580 if (IS_ERR(req
->open
.filename
)) {
2581 ret
= PTR_ERR(req
->open
.filename
);
2582 req
->open
.filename
= NULL
;
2589 static int io_openat2(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2590 bool force_nonblock
)
2592 struct open_flags op
;
2599 ret
= build_open_flags(&req
->open
.how
, &op
);
2603 ret
= get_unused_fd_flags(req
->open
.how
.flags
);
2607 file
= do_filp_open(req
->open
.dfd
, req
->open
.filename
, &op
);
2610 ret
= PTR_ERR(file
);
2612 fsnotify_open(file
);
2613 fd_install(ret
, file
);
2616 putname(req
->open
.filename
);
2618 req_set_fail_links(req
);
2619 io_cqring_add_event(req
, ret
);
2620 io_put_req_find_next(req
, nxt
);
2624 static int io_openat(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2625 bool force_nonblock
)
2627 req
->open
.how
= build_open_how(req
->open
.how
.flags
, req
->open
.how
.mode
);
2628 return io_openat2(req
, nxt
, force_nonblock
);
2631 static int io_epoll_ctl_prep(struct io_kiocb
*req
,
2632 const struct io_uring_sqe
*sqe
)
2634 #if defined(CONFIG_EPOLL)
2635 if (sqe
->ioprio
|| sqe
->buf_index
)
2638 req
->epoll
.epfd
= READ_ONCE(sqe
->fd
);
2639 req
->epoll
.op
= READ_ONCE(sqe
->len
);
2640 req
->epoll
.fd
= READ_ONCE(sqe
->off
);
2642 if (ep_op_has_event(req
->epoll
.op
)) {
2643 struct epoll_event __user
*ev
;
2645 ev
= u64_to_user_ptr(READ_ONCE(sqe
->addr
));
2646 if (copy_from_user(&req
->epoll
.event
, ev
, sizeof(*ev
)))
2656 static int io_epoll_ctl(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2657 bool force_nonblock
)
2659 #if defined(CONFIG_EPOLL)
2660 struct io_epoll
*ie
= &req
->epoll
;
2663 ret
= do_epoll_ctl(ie
->epfd
, ie
->op
, ie
->fd
, &ie
->event
, force_nonblock
);
2664 if (force_nonblock
&& ret
== -EAGAIN
)
2668 req_set_fail_links(req
);
2669 io_cqring_add_event(req
, ret
);
2670 io_put_req_find_next(req
, nxt
);
2677 static int io_madvise_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2679 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
2680 if (sqe
->ioprio
|| sqe
->buf_index
|| sqe
->off
)
2683 req
->madvise
.addr
= READ_ONCE(sqe
->addr
);
2684 req
->madvise
.len
= READ_ONCE(sqe
->len
);
2685 req
->madvise
.advice
= READ_ONCE(sqe
->fadvise_advice
);
2692 static int io_madvise(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2693 bool force_nonblock
)
2695 #if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
2696 struct io_madvise
*ma
= &req
->madvise
;
2702 ret
= do_madvise(ma
->addr
, ma
->len
, ma
->advice
);
2704 req_set_fail_links(req
);
2705 io_cqring_add_event(req
, ret
);
2706 io_put_req_find_next(req
, nxt
);
2713 static int io_fadvise_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2715 if (sqe
->ioprio
|| sqe
->buf_index
|| sqe
->addr
)
2718 req
->fadvise
.offset
= READ_ONCE(sqe
->off
);
2719 req
->fadvise
.len
= READ_ONCE(sqe
->len
);
2720 req
->fadvise
.advice
= READ_ONCE(sqe
->fadvise_advice
);
2724 static int io_fadvise(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2725 bool force_nonblock
)
2727 struct io_fadvise
*fa
= &req
->fadvise
;
2730 if (force_nonblock
) {
2731 switch (fa
->advice
) {
2732 case POSIX_FADV_NORMAL
:
2733 case POSIX_FADV_RANDOM
:
2734 case POSIX_FADV_SEQUENTIAL
:
2741 ret
= vfs_fadvise(req
->file
, fa
->offset
, fa
->len
, fa
->advice
);
2743 req_set_fail_links(req
);
2744 io_cqring_add_event(req
, ret
);
2745 io_put_req_find_next(req
, nxt
);
2749 static int io_statx_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2751 const char __user
*fname
;
2752 unsigned lookup_flags
;
2755 if (sqe
->ioprio
|| sqe
->buf_index
)
2758 req
->open
.dfd
= READ_ONCE(sqe
->fd
);
2759 req
->open
.mask
= READ_ONCE(sqe
->len
);
2760 fname
= u64_to_user_ptr(READ_ONCE(sqe
->addr
));
2761 req
->open
.buffer
= u64_to_user_ptr(READ_ONCE(sqe
->addr2
));
2762 req
->open
.how
.flags
= READ_ONCE(sqe
->statx_flags
);
2764 if (vfs_stat_set_lookup_flags(&lookup_flags
, req
->open
.how
.flags
))
2767 req
->open
.filename
= getname_flags(fname
, lookup_flags
, NULL
);
2768 if (IS_ERR(req
->open
.filename
)) {
2769 ret
= PTR_ERR(req
->open
.filename
);
2770 req
->open
.filename
= NULL
;
2777 static int io_statx(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2778 bool force_nonblock
)
2780 struct io_open
*ctx
= &req
->open
;
2781 unsigned lookup_flags
;
2789 if (vfs_stat_set_lookup_flags(&lookup_flags
, ctx
->how
.flags
))
2793 /* filename_lookup() drops it, keep a reference */
2794 ctx
->filename
->refcnt
++;
2796 ret
= filename_lookup(ctx
->dfd
, ctx
->filename
, lookup_flags
, &path
,
2801 ret
= vfs_getattr(&path
, &stat
, ctx
->mask
, ctx
->how
.flags
);
2803 if (retry_estale(ret
, lookup_flags
)) {
2804 lookup_flags
|= LOOKUP_REVAL
;
2808 ret
= cp_statx(&stat
, ctx
->buffer
);
2810 putname(ctx
->filename
);
2812 req_set_fail_links(req
);
2813 io_cqring_add_event(req
, ret
);
2814 io_put_req_find_next(req
, nxt
);
2818 static int io_close_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2821 * If we queue this for async, it must not be cancellable. That would
2822 * leave the 'file' in an undeterminate state.
2824 req
->work
.flags
|= IO_WQ_WORK_NO_CANCEL
;
2826 if (sqe
->ioprio
|| sqe
->off
|| sqe
->addr
|| sqe
->len
||
2827 sqe
->rw_flags
|| sqe
->buf_index
)
2829 if (sqe
->flags
& IOSQE_FIXED_FILE
)
2832 req
->close
.fd
= READ_ONCE(sqe
->fd
);
2833 if (req
->file
->f_op
== &io_uring_fops
||
2834 req
->close
.fd
== req
->ctx
->ring_fd
)
2840 static void io_close_finish(struct io_wq_work
**workptr
)
2842 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
2843 struct io_kiocb
*nxt
= NULL
;
2845 /* Invoked with files, we need to do the close */
2846 if (req
->work
.files
) {
2849 ret
= filp_close(req
->close
.put_file
, req
->work
.files
);
2851 req_set_fail_links(req
);
2852 io_cqring_add_event(req
, ret
);
2855 fput(req
->close
.put_file
);
2857 io_put_req_find_next(req
, &nxt
);
2859 io_wq_assign_next(workptr
, nxt
);
2862 static int io_close(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2863 bool force_nonblock
)
2867 req
->close
.put_file
= NULL
;
2868 ret
= __close_fd_get_file(req
->close
.fd
, &req
->close
.put_file
);
2872 /* if the file has a flush method, be safe and punt to async */
2873 if (req
->close
.put_file
->f_op
->flush
&& !io_wq_current_is_worker())
2877 * No ->flush(), safely close from here and just punt the
2878 * fput() to async context.
2880 ret
= filp_close(req
->close
.put_file
, current
->files
);
2883 req_set_fail_links(req
);
2884 io_cqring_add_event(req
, ret
);
2886 if (io_wq_current_is_worker()) {
2887 struct io_wq_work
*old_work
, *work
;
2889 old_work
= work
= &req
->work
;
2890 io_close_finish(&work
);
2891 if (work
&& work
!= old_work
)
2892 *nxt
= container_of(work
, struct io_kiocb
, work
);
2897 req
->work
.func
= io_close_finish
;
2899 * Do manual async queue here to avoid grabbing files - we don't
2900 * need the files, and it'll cause io_close_finish() to close
2901 * the file again and cause a double CQE entry for this request
2903 io_queue_async_work(req
);
2907 static int io_prep_sfr(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2909 struct io_ring_ctx
*ctx
= req
->ctx
;
2914 if (unlikely(ctx
->flags
& IORING_SETUP_IOPOLL
))
2916 if (unlikely(sqe
->addr
|| sqe
->ioprio
|| sqe
->buf_index
))
2919 req
->sync
.off
= READ_ONCE(sqe
->off
);
2920 req
->sync
.len
= READ_ONCE(sqe
->len
);
2921 req
->sync
.flags
= READ_ONCE(sqe
->sync_range_flags
);
2925 static void io_sync_file_range_finish(struct io_wq_work
**workptr
)
2927 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
2928 struct io_kiocb
*nxt
= NULL
;
2931 if (io_req_cancelled(req
))
2934 ret
= sync_file_range(req
->file
, req
->sync
.off
, req
->sync
.len
,
2937 req_set_fail_links(req
);
2938 io_cqring_add_event(req
, ret
);
2939 io_put_req_find_next(req
, &nxt
);
2941 io_wq_assign_next(workptr
, nxt
);
2944 static int io_sync_file_range(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2945 bool force_nonblock
)
2947 struct io_wq_work
*work
, *old_work
;
2949 /* sync_file_range always requires a blocking context */
2950 if (force_nonblock
) {
2952 req
->work
.func
= io_sync_file_range_finish
;
2956 work
= old_work
= &req
->work
;
2957 io_sync_file_range_finish(&work
);
2958 if (work
&& work
!= old_work
)
2959 *nxt
= container_of(work
, struct io_kiocb
, work
);
2963 #if defined(CONFIG_NET)
2964 static void io_sendrecv_async(struct io_wq_work
**workptr
)
2966 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
2967 struct iovec
*iov
= NULL
;
2969 if (req
->io
->rw
.iov
!= req
->io
->rw
.fast_iov
)
2970 iov
= req
->io
->msg
.iov
;
2971 io_wq_submit_work(workptr
);
2976 static int io_sendmsg_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
2978 #if defined(CONFIG_NET)
2979 struct io_sr_msg
*sr
= &req
->sr_msg
;
2980 struct io_async_ctx
*io
= req
->io
;
2982 sr
->msg_flags
= READ_ONCE(sqe
->msg_flags
);
2983 sr
->msg
= u64_to_user_ptr(READ_ONCE(sqe
->addr
));
2984 sr
->len
= READ_ONCE(sqe
->len
);
2986 if (!io
|| req
->opcode
== IORING_OP_SEND
)
2989 io
->msg
.iov
= io
->msg
.fast_iov
;
2990 return sendmsg_copy_msghdr(&io
->msg
.msg
, sr
->msg
, sr
->msg_flags
,
2997 static int io_sendmsg(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
2998 bool force_nonblock
)
3000 #if defined(CONFIG_NET)
3001 struct io_async_msghdr
*kmsg
= NULL
;
3002 struct socket
*sock
;
3005 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
3008 sock
= sock_from_file(req
->file
, &ret
);
3010 struct io_async_ctx io
;
3011 struct sockaddr_storage addr
;
3015 kmsg
= &req
->io
->msg
;
3016 kmsg
->msg
.msg_name
= &addr
;
3017 /* if iov is set, it's allocated already */
3019 kmsg
->iov
= kmsg
->fast_iov
;
3020 kmsg
->msg
.msg_iter
.iov
= kmsg
->iov
;
3022 struct io_sr_msg
*sr
= &req
->sr_msg
;
3025 kmsg
->msg
.msg_name
= &addr
;
3027 io
.msg
.iov
= io
.msg
.fast_iov
;
3028 ret
= sendmsg_copy_msghdr(&io
.msg
.msg
, sr
->msg
,
3029 sr
->msg_flags
, &io
.msg
.iov
);
3034 flags
= req
->sr_msg
.msg_flags
;
3035 if (flags
& MSG_DONTWAIT
)
3036 req
->flags
|= REQ_F_NOWAIT
;
3037 else if (force_nonblock
)
3038 flags
|= MSG_DONTWAIT
;
3040 ret
= __sys_sendmsg_sock(sock
, &kmsg
->msg
, flags
);
3041 if (force_nonblock
&& ret
== -EAGAIN
) {
3044 if (io_alloc_async_ctx(req
))
3046 memcpy(&req
->io
->msg
, &io
.msg
, sizeof(io
.msg
));
3047 req
->work
.func
= io_sendrecv_async
;
3050 if (ret
== -ERESTARTSYS
)
3054 if (!io_wq_current_is_worker() && kmsg
&& kmsg
->iov
!= kmsg
->fast_iov
)
3056 io_cqring_add_event(req
, ret
);
3058 req_set_fail_links(req
);
3059 io_put_req_find_next(req
, nxt
);
3066 static int io_send(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
3067 bool force_nonblock
)
3069 #if defined(CONFIG_NET)
3070 struct socket
*sock
;
3073 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
3076 sock
= sock_from_file(req
->file
, &ret
);
3078 struct io_sr_msg
*sr
= &req
->sr_msg
;
3083 ret
= import_single_range(WRITE
, sr
->buf
, sr
->len
, &iov
,
3088 msg
.msg_name
= NULL
;
3089 msg
.msg_control
= NULL
;
3090 msg
.msg_controllen
= 0;
3091 msg
.msg_namelen
= 0;
3093 flags
= req
->sr_msg
.msg_flags
;
3094 if (flags
& MSG_DONTWAIT
)
3095 req
->flags
|= REQ_F_NOWAIT
;
3096 else if (force_nonblock
)
3097 flags
|= MSG_DONTWAIT
;
3099 msg
.msg_flags
= flags
;
3100 ret
= sock_sendmsg(sock
, &msg
);
3101 if (force_nonblock
&& ret
== -EAGAIN
)
3103 if (ret
== -ERESTARTSYS
)
3107 io_cqring_add_event(req
, ret
);
3109 req_set_fail_links(req
);
3110 io_put_req_find_next(req
, nxt
);
3117 static int io_recvmsg_prep(struct io_kiocb
*req
,
3118 const struct io_uring_sqe
*sqe
)
3120 #if defined(CONFIG_NET)
3121 struct io_sr_msg
*sr
= &req
->sr_msg
;
3122 struct io_async_ctx
*io
= req
->io
;
3124 sr
->msg_flags
= READ_ONCE(sqe
->msg_flags
);
3125 sr
->msg
= u64_to_user_ptr(READ_ONCE(sqe
->addr
));
3126 sr
->len
= READ_ONCE(sqe
->len
);
3128 if (!io
|| req
->opcode
== IORING_OP_RECV
)
3131 io
->msg
.iov
= io
->msg
.fast_iov
;
3132 return recvmsg_copy_msghdr(&io
->msg
.msg
, sr
->msg
, sr
->msg_flags
,
3133 &io
->msg
.uaddr
, &io
->msg
.iov
);
3139 static int io_recvmsg(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
3140 bool force_nonblock
)
3142 #if defined(CONFIG_NET)
3143 struct io_async_msghdr
*kmsg
= NULL
;
3144 struct socket
*sock
;
3147 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
3150 sock
= sock_from_file(req
->file
, &ret
);
3152 struct io_async_ctx io
;
3153 struct sockaddr_storage addr
;
3157 kmsg
= &req
->io
->msg
;
3158 kmsg
->msg
.msg_name
= &addr
;
3159 /* if iov is set, it's allocated already */
3161 kmsg
->iov
= kmsg
->fast_iov
;
3162 kmsg
->msg
.msg_iter
.iov
= kmsg
->iov
;
3164 struct io_sr_msg
*sr
= &req
->sr_msg
;
3167 kmsg
->msg
.msg_name
= &addr
;
3169 io
.msg
.iov
= io
.msg
.fast_iov
;
3170 ret
= recvmsg_copy_msghdr(&io
.msg
.msg
, sr
->msg
,
3171 sr
->msg_flags
, &io
.msg
.uaddr
,
3177 flags
= req
->sr_msg
.msg_flags
;
3178 if (flags
& MSG_DONTWAIT
)
3179 req
->flags
|= REQ_F_NOWAIT
;
3180 else if (force_nonblock
)
3181 flags
|= MSG_DONTWAIT
;
3183 ret
= __sys_recvmsg_sock(sock
, &kmsg
->msg
, req
->sr_msg
.msg
,
3184 kmsg
->uaddr
, flags
);
3185 if (force_nonblock
&& ret
== -EAGAIN
) {
3188 if (io_alloc_async_ctx(req
))
3190 memcpy(&req
->io
->msg
, &io
.msg
, sizeof(io
.msg
));
3191 req
->work
.func
= io_sendrecv_async
;
3194 if (ret
== -ERESTARTSYS
)
3198 if (!io_wq_current_is_worker() && kmsg
&& kmsg
->iov
!= kmsg
->fast_iov
)
3200 io_cqring_add_event(req
, ret
);
3202 req_set_fail_links(req
);
3203 io_put_req_find_next(req
, nxt
);
3210 static int io_recv(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
3211 bool force_nonblock
)
3213 #if defined(CONFIG_NET)
3214 struct socket
*sock
;
3217 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
3220 sock
= sock_from_file(req
->file
, &ret
);
3222 struct io_sr_msg
*sr
= &req
->sr_msg
;
3227 ret
= import_single_range(READ
, sr
->buf
, sr
->len
, &iov
,
3232 msg
.msg_name
= NULL
;
3233 msg
.msg_control
= NULL
;
3234 msg
.msg_controllen
= 0;
3235 msg
.msg_namelen
= 0;
3236 msg
.msg_iocb
= NULL
;
3239 flags
= req
->sr_msg
.msg_flags
;
3240 if (flags
& MSG_DONTWAIT
)
3241 req
->flags
|= REQ_F_NOWAIT
;
3242 else if (force_nonblock
)
3243 flags
|= MSG_DONTWAIT
;
3245 ret
= sock_recvmsg(sock
, &msg
, flags
);
3246 if (force_nonblock
&& ret
== -EAGAIN
)
3248 if (ret
== -ERESTARTSYS
)
3252 io_cqring_add_event(req
, ret
);
3254 req_set_fail_links(req
);
3255 io_put_req_find_next(req
, nxt
);
3263 static int io_accept_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
3265 #if defined(CONFIG_NET)
3266 struct io_accept
*accept
= &req
->accept
;
3268 if (unlikely(req
->ctx
->flags
& (IORING_SETUP_IOPOLL
|IORING_SETUP_SQPOLL
)))
3270 if (sqe
->ioprio
|| sqe
->len
|| sqe
->buf_index
)
3273 accept
->addr
= u64_to_user_ptr(READ_ONCE(sqe
->addr
));
3274 accept
->addr_len
= u64_to_user_ptr(READ_ONCE(sqe
->addr2
));
3275 accept
->flags
= READ_ONCE(sqe
->accept_flags
);
3282 #if defined(CONFIG_NET)
3283 static int __io_accept(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
3284 bool force_nonblock
)
3286 struct io_accept
*accept
= &req
->accept
;
3287 unsigned file_flags
;
3290 file_flags
= force_nonblock
? O_NONBLOCK
: 0;
3291 ret
= __sys_accept4_file(req
->file
, file_flags
, accept
->addr
,
3292 accept
->addr_len
, accept
->flags
);
3293 if (ret
== -EAGAIN
&& force_nonblock
)
3295 if (ret
== -ERESTARTSYS
)
3298 req_set_fail_links(req
);
3299 io_cqring_add_event(req
, ret
);
3300 io_put_req_find_next(req
, nxt
);
3304 static void io_accept_finish(struct io_wq_work
**workptr
)
3306 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
3307 struct io_kiocb
*nxt
= NULL
;
3309 if (io_req_cancelled(req
))
3311 __io_accept(req
, &nxt
, false);
3313 io_wq_assign_next(workptr
, nxt
);
3317 static int io_accept(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
3318 bool force_nonblock
)
3320 #if defined(CONFIG_NET)
3323 ret
= __io_accept(req
, nxt
, force_nonblock
);
3324 if (ret
== -EAGAIN
&& force_nonblock
) {
3325 req
->work
.func
= io_accept_finish
;
3335 static int io_connect_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
3337 #if defined(CONFIG_NET)
3338 struct io_connect
*conn
= &req
->connect
;
3339 struct io_async_ctx
*io
= req
->io
;
3341 if (unlikely(req
->ctx
->flags
& (IORING_SETUP_IOPOLL
|IORING_SETUP_SQPOLL
)))
3343 if (sqe
->ioprio
|| sqe
->len
|| sqe
->buf_index
|| sqe
->rw_flags
)
3346 conn
->addr
= u64_to_user_ptr(READ_ONCE(sqe
->addr
));
3347 conn
->addr_len
= READ_ONCE(sqe
->addr2
);
3352 return move_addr_to_kernel(conn
->addr
, conn
->addr_len
,
3353 &io
->connect
.address
);
3359 static int io_connect(struct io_kiocb
*req
, struct io_kiocb
**nxt
,
3360 bool force_nonblock
)
3362 #if defined(CONFIG_NET)
3363 struct io_async_ctx __io
, *io
;
3364 unsigned file_flags
;
3370 ret
= move_addr_to_kernel(req
->connect
.addr
,
3371 req
->connect
.addr_len
,
3372 &__io
.connect
.address
);
3378 file_flags
= force_nonblock
? O_NONBLOCK
: 0;
3380 ret
= __sys_connect_file(req
->file
, &io
->connect
.address
,
3381 req
->connect
.addr_len
, file_flags
);
3382 if ((ret
== -EAGAIN
|| ret
== -EINPROGRESS
) && force_nonblock
) {
3385 if (io_alloc_async_ctx(req
)) {
3389 memcpy(&req
->io
->connect
, &__io
.connect
, sizeof(__io
.connect
));
3392 if (ret
== -ERESTARTSYS
)
3396 req_set_fail_links(req
);
3397 io_cqring_add_event(req
, ret
);
3398 io_put_req_find_next(req
, nxt
);
3405 static void io_poll_remove_one(struct io_kiocb
*req
)
3407 struct io_poll_iocb
*poll
= &req
->poll
;
3409 spin_lock(&poll
->head
->lock
);
3410 WRITE_ONCE(poll
->canceled
, true);
3411 if (!list_empty(&poll
->wait
.entry
)) {
3412 list_del_init(&poll
->wait
.entry
);
3413 io_queue_async_work(req
);
3415 spin_unlock(&poll
->head
->lock
);
3416 hash_del(&req
->hash_node
);
3419 static void io_poll_remove_all(struct io_ring_ctx
*ctx
)
3421 struct hlist_node
*tmp
;
3422 struct io_kiocb
*req
;
3425 spin_lock_irq(&ctx
->completion_lock
);
3426 for (i
= 0; i
< (1U << ctx
->cancel_hash_bits
); i
++) {
3427 struct hlist_head
*list
;
3429 list
= &ctx
->cancel_hash
[i
];
3430 hlist_for_each_entry_safe(req
, tmp
, list
, hash_node
)
3431 io_poll_remove_one(req
);
3433 spin_unlock_irq(&ctx
->completion_lock
);
3436 static int io_poll_cancel(struct io_ring_ctx
*ctx
, __u64 sqe_addr
)
3438 struct hlist_head
*list
;
3439 struct io_kiocb
*req
;
3441 list
= &ctx
->cancel_hash
[hash_long(sqe_addr
, ctx
->cancel_hash_bits
)];
3442 hlist_for_each_entry(req
, list
, hash_node
) {
3443 if (sqe_addr
== req
->user_data
) {
3444 io_poll_remove_one(req
);
3452 static int io_poll_remove_prep(struct io_kiocb
*req
,
3453 const struct io_uring_sqe
*sqe
)
3455 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
3457 if (sqe
->ioprio
|| sqe
->off
|| sqe
->len
|| sqe
->buf_index
||
3461 req
->poll
.addr
= READ_ONCE(sqe
->addr
);
3466 * Find a running poll command that matches one specified in sqe->addr,
3467 * and remove it if found.
3469 static int io_poll_remove(struct io_kiocb
*req
)
3471 struct io_ring_ctx
*ctx
= req
->ctx
;
3475 addr
= req
->poll
.addr
;
3476 spin_lock_irq(&ctx
->completion_lock
);
3477 ret
= io_poll_cancel(ctx
, addr
);
3478 spin_unlock_irq(&ctx
->completion_lock
);
3480 io_cqring_add_event(req
, ret
);
3482 req_set_fail_links(req
);
3487 static void io_poll_complete(struct io_kiocb
*req
, __poll_t mask
, int error
)
3489 struct io_ring_ctx
*ctx
= req
->ctx
;
3491 req
->poll
.done
= true;
3493 io_cqring_fill_event(req
, error
);
3495 io_cqring_fill_event(req
, mangle_poll(mask
));
3496 io_commit_cqring(ctx
);
3499 static void io_poll_complete_work(struct io_wq_work
**workptr
)
3501 struct io_wq_work
*work
= *workptr
;
3502 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
3503 struct io_poll_iocb
*poll
= &req
->poll
;
3504 struct poll_table_struct pt
= { ._key
= poll
->events
};
3505 struct io_ring_ctx
*ctx
= req
->ctx
;
3506 struct io_kiocb
*nxt
= NULL
;
3510 if (work
->flags
& IO_WQ_WORK_CANCEL
) {
3511 WRITE_ONCE(poll
->canceled
, true);
3513 } else if (READ_ONCE(poll
->canceled
)) {
3517 if (ret
!= -ECANCELED
)
3518 mask
= vfs_poll(poll
->file
, &pt
) & poll
->events
;
3521 * Note that ->ki_cancel callers also delete iocb from active_reqs after
3522 * calling ->ki_cancel. We need the ctx_lock roundtrip here to
3523 * synchronize with them. In the cancellation case the list_del_init
3524 * itself is not actually needed, but harmless so we keep it in to
3525 * avoid further branches in the fast path.
3527 spin_lock_irq(&ctx
->completion_lock
);
3528 if (!mask
&& ret
!= -ECANCELED
) {
3529 add_wait_queue(poll
->head
, &poll
->wait
);
3530 spin_unlock_irq(&ctx
->completion_lock
);
3533 hash_del(&req
->hash_node
);
3534 io_poll_complete(req
, mask
, ret
);
3535 spin_unlock_irq(&ctx
->completion_lock
);
3537 io_cqring_ev_posted(ctx
);
3540 req_set_fail_links(req
);
3541 io_put_req_find_next(req
, &nxt
);
3543 io_wq_assign_next(workptr
, nxt
);
3546 static void __io_poll_flush(struct io_ring_ctx
*ctx
, struct llist_node
*nodes
)
3548 struct io_kiocb
*req
, *tmp
;
3549 struct req_batch rb
;
3551 rb
.to_free
= rb
.need_iter
= 0;
3552 spin_lock_irq(&ctx
->completion_lock
);
3553 llist_for_each_entry_safe(req
, tmp
, nodes
, llist_node
) {
3554 hash_del(&req
->hash_node
);
3555 io_poll_complete(req
, req
->result
, 0);
3557 if (refcount_dec_and_test(&req
->refs
) &&
3558 !io_req_multi_free(&rb
, req
)) {
3559 req
->flags
|= REQ_F_COMP_LOCKED
;
3563 spin_unlock_irq(&ctx
->completion_lock
);
3565 io_cqring_ev_posted(ctx
);
3566 io_free_req_many(ctx
, &rb
);
3569 static void io_poll_flush(struct io_wq_work
**workptr
)
3571 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
3572 struct llist_node
*nodes
;
3574 nodes
= llist_del_all(&req
->ctx
->poll_llist
);
3576 __io_poll_flush(req
->ctx
, nodes
);
3579 static void io_poll_trigger_evfd(struct io_wq_work
**workptr
)
3581 struct io_kiocb
*req
= container_of(*workptr
, struct io_kiocb
, work
);
3583 eventfd_signal(req
->ctx
->cq_ev_fd
, 1);
3587 static int io_poll_wake(struct wait_queue_entry
*wait
, unsigned mode
, int sync
,
3590 struct io_poll_iocb
*poll
= wait
->private;
3591 struct io_kiocb
*req
= container_of(poll
, struct io_kiocb
, poll
);
3592 struct io_ring_ctx
*ctx
= req
->ctx
;
3593 __poll_t mask
= key_to_poll(key
);
3595 /* for instances that support it check for an event match first: */
3596 if (mask
&& !(mask
& poll
->events
))
3599 list_del_init(&poll
->wait
.entry
);
3602 * Run completion inline if we can. We're using trylock here because
3603 * we are violating the completion_lock -> poll wq lock ordering.
3604 * If we have a link timeout we're going to need the completion_lock
3605 * for finalizing the request, mark us as having grabbed that already.
3608 unsigned long flags
;
3610 if (llist_empty(&ctx
->poll_llist
) &&
3611 spin_trylock_irqsave(&ctx
->completion_lock
, flags
)) {
3614 hash_del(&req
->hash_node
);
3615 io_poll_complete(req
, mask
, 0);
3617 trigger_ev
= io_should_trigger_evfd(ctx
);
3618 if (trigger_ev
&& eventfd_signal_count()) {
3620 req
->work
.func
= io_poll_trigger_evfd
;
3622 req
->flags
|= REQ_F_COMP_LOCKED
;
3626 spin_unlock_irqrestore(&ctx
->completion_lock
, flags
);
3627 __io_cqring_ev_posted(ctx
, trigger_ev
);
3630 req
->llist_node
.next
= NULL
;
3631 /* if the list wasn't empty, we're done */
3632 if (!llist_add(&req
->llist_node
, &ctx
->poll_llist
))
3635 req
->work
.func
= io_poll_flush
;
3639 io_queue_async_work(req
);
3644 struct io_poll_table
{
3645 struct poll_table_struct pt
;
3646 struct io_kiocb
*req
;
3650 static void io_poll_queue_proc(struct file
*file
, struct wait_queue_head
*head
,
3651 struct poll_table_struct
*p
)
3653 struct io_poll_table
*pt
= container_of(p
, struct io_poll_table
, pt
);
3655 if (unlikely(pt
->req
->poll
.head
)) {
3656 pt
->error
= -EINVAL
;
3661 pt
->req
->poll
.head
= head
;
3662 add_wait_queue(head
, &pt
->req
->poll
.wait
);
3665 static void io_poll_req_insert(struct io_kiocb
*req
)
3667 struct io_ring_ctx
*ctx
= req
->ctx
;
3668 struct hlist_head
*list
;
3670 list
= &ctx
->cancel_hash
[hash_long(req
->user_data
, ctx
->cancel_hash_bits
)];
3671 hlist_add_head(&req
->hash_node
, list
);
3674 static int io_poll_add_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
3676 struct io_poll_iocb
*poll
= &req
->poll
;
3679 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
3681 if (sqe
->addr
|| sqe
->ioprio
|| sqe
->off
|| sqe
->len
|| sqe
->buf_index
)
3686 events
= READ_ONCE(sqe
->poll_events
);
3687 poll
->events
= demangle_poll(events
) | EPOLLERR
| EPOLLHUP
;
3691 static int io_poll_add(struct io_kiocb
*req
, struct io_kiocb
**nxt
)
3693 struct io_poll_iocb
*poll
= &req
->poll
;
3694 struct io_ring_ctx
*ctx
= req
->ctx
;
3695 struct io_poll_table ipt
;
3696 bool cancel
= false;
3699 INIT_IO_WORK(&req
->work
, io_poll_complete_work
);
3700 INIT_HLIST_NODE(&req
->hash_node
);
3704 poll
->canceled
= false;
3706 ipt
.pt
._qproc
= io_poll_queue_proc
;
3707 ipt
.pt
._key
= poll
->events
;
3709 ipt
.error
= -EINVAL
; /* same as no support for IOCB_CMD_POLL */
3711 /* initialized the list so that we can do list_empty checks */
3712 INIT_LIST_HEAD(&poll
->wait
.entry
);
3713 init_waitqueue_func_entry(&poll
->wait
, io_poll_wake
);
3714 poll
->wait
.private = poll
;
3716 INIT_LIST_HEAD(&req
->list
);
3718 mask
= vfs_poll(poll
->file
, &ipt
.pt
) & poll
->events
;
3720 spin_lock_irq(&ctx
->completion_lock
);
3721 if (likely(poll
->head
)) {
3722 spin_lock(&poll
->head
->lock
);
3723 if (unlikely(list_empty(&poll
->wait
.entry
))) {
3729 if (mask
|| ipt
.error
)
3730 list_del_init(&poll
->wait
.entry
);
3732 WRITE_ONCE(poll
->canceled
, true);
3733 else if (!poll
->done
) /* actually waiting for an event */
3734 io_poll_req_insert(req
);
3735 spin_unlock(&poll
->head
->lock
);
3737 if (mask
) { /* no async, we'd stolen it */
3739 io_poll_complete(req
, mask
, 0);
3741 spin_unlock_irq(&ctx
->completion_lock
);
3744 io_cqring_ev_posted(ctx
);
3745 io_put_req_find_next(req
, nxt
);
3750 static enum hrtimer_restart
io_timeout_fn(struct hrtimer
*timer
)
3752 struct io_timeout_data
*data
= container_of(timer
,
3753 struct io_timeout_data
, timer
);
3754 struct io_kiocb
*req
= data
->req
;
3755 struct io_ring_ctx
*ctx
= req
->ctx
;
3756 unsigned long flags
;
3758 atomic_inc(&ctx
->cq_timeouts
);
3760 spin_lock_irqsave(&ctx
->completion_lock
, flags
);
3762 * We could be racing with timeout deletion. If the list is empty,
3763 * then timeout lookup already found it and will be handling it.
3765 if (!list_empty(&req
->list
)) {
3766 struct io_kiocb
*prev
;
3769 * Adjust the reqs sequence before the current one because it
3770 * will consume a slot in the cq_ring and the cq_tail
3771 * pointer will be increased, otherwise other timeout reqs may
3772 * return in advance without waiting for enough wait_nr.
3775 list_for_each_entry_continue_reverse(prev
, &ctx
->timeout_list
, list
)
3777 list_del_init(&req
->list
);
3780 io_cqring_fill_event(req
, -ETIME
);
3781 io_commit_cqring(ctx
);
3782 spin_unlock_irqrestore(&ctx
->completion_lock
, flags
);
3784 io_cqring_ev_posted(ctx
);
3785 req_set_fail_links(req
);
3787 return HRTIMER_NORESTART
;
3790 static int io_timeout_cancel(struct io_ring_ctx
*ctx
, __u64 user_data
)
3792 struct io_kiocb
*req
;
3795 list_for_each_entry(req
, &ctx
->timeout_list
, list
) {
3796 if (user_data
== req
->user_data
) {
3797 list_del_init(&req
->list
);
3806 ret
= hrtimer_try_to_cancel(&req
->io
->timeout
.timer
);
3810 req_set_fail_links(req
);
3811 io_cqring_fill_event(req
, -ECANCELED
);
3816 static int io_timeout_remove_prep(struct io_kiocb
*req
,
3817 const struct io_uring_sqe
*sqe
)
3819 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
3821 if (sqe
->flags
|| sqe
->ioprio
|| sqe
->buf_index
|| sqe
->len
)
3824 req
->timeout
.addr
= READ_ONCE(sqe
->addr
);
3825 req
->timeout
.flags
= READ_ONCE(sqe
->timeout_flags
);
3826 if (req
->timeout
.flags
)
3833 * Remove or update an existing timeout command
3835 static int io_timeout_remove(struct io_kiocb
*req
)
3837 struct io_ring_ctx
*ctx
= req
->ctx
;
3840 spin_lock_irq(&ctx
->completion_lock
);
3841 ret
= io_timeout_cancel(ctx
, req
->timeout
.addr
);
3843 io_cqring_fill_event(req
, ret
);
3844 io_commit_cqring(ctx
);
3845 spin_unlock_irq(&ctx
->completion_lock
);
3846 io_cqring_ev_posted(ctx
);
3848 req_set_fail_links(req
);
3853 static int io_timeout_prep(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
,
3854 bool is_timeout_link
)
3856 struct io_timeout_data
*data
;
3859 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
3861 if (sqe
->ioprio
|| sqe
->buf_index
|| sqe
->len
!= 1)
3863 if (sqe
->off
&& is_timeout_link
)
3865 flags
= READ_ONCE(sqe
->timeout_flags
);
3866 if (flags
& ~IORING_TIMEOUT_ABS
)
3869 req
->timeout
.count
= READ_ONCE(sqe
->off
);
3871 if (!req
->io
&& io_alloc_async_ctx(req
))
3874 data
= &req
->io
->timeout
;
3876 req
->flags
|= REQ_F_TIMEOUT
;
3878 if (get_timespec64(&data
->ts
, u64_to_user_ptr(sqe
->addr
)))
3881 if (flags
& IORING_TIMEOUT_ABS
)
3882 data
->mode
= HRTIMER_MODE_ABS
;
3884 data
->mode
= HRTIMER_MODE_REL
;
3886 hrtimer_init(&data
->timer
, CLOCK_MONOTONIC
, data
->mode
);
3890 static int io_timeout(struct io_kiocb
*req
)
3893 struct io_ring_ctx
*ctx
= req
->ctx
;
3894 struct io_timeout_data
*data
;
3895 struct list_head
*entry
;
3898 data
= &req
->io
->timeout
;
3901 * sqe->off holds how many events that need to occur for this
3902 * timeout event to be satisfied. If it isn't set, then this is
3903 * a pure timeout request, sequence isn't used.
3905 count
= req
->timeout
.count
;
3907 req
->flags
|= REQ_F_TIMEOUT_NOSEQ
;
3908 spin_lock_irq(&ctx
->completion_lock
);
3909 entry
= ctx
->timeout_list
.prev
;
3913 req
->sequence
= ctx
->cached_sq_head
+ count
- 1;
3914 data
->seq_offset
= count
;
3917 * Insertion sort, ensuring the first entry in the list is always
3918 * the one we need first.
3920 spin_lock_irq(&ctx
->completion_lock
);
3921 list_for_each_prev(entry
, &ctx
->timeout_list
) {
3922 struct io_kiocb
*nxt
= list_entry(entry
, struct io_kiocb
, list
);
3923 unsigned nxt_sq_head
;
3924 long long tmp
, tmp_nxt
;
3925 u32 nxt_offset
= nxt
->io
->timeout
.seq_offset
;
3927 if (nxt
->flags
& REQ_F_TIMEOUT_NOSEQ
)
3931 * Since cached_sq_head + count - 1 can overflow, use type long
3934 tmp
= (long long)ctx
->cached_sq_head
+ count
- 1;
3935 nxt_sq_head
= nxt
->sequence
- nxt_offset
+ 1;
3936 tmp_nxt
= (long long)nxt_sq_head
+ nxt_offset
- 1;
3939 * cached_sq_head may overflow, and it will never overflow twice
3940 * once there is some timeout req still be valid.
3942 if (ctx
->cached_sq_head
< nxt_sq_head
)
3949 * Sequence of reqs after the insert one and itself should
3950 * be adjusted because each timeout req consumes a slot.
3955 req
->sequence
-= span
;
3957 list_add(&req
->list
, entry
);
3958 data
->timer
.function
= io_timeout_fn
;
3959 hrtimer_start(&data
->timer
, timespec64_to_ktime(data
->ts
), data
->mode
);
3960 spin_unlock_irq(&ctx
->completion_lock
);
3964 static bool io_cancel_cb(struct io_wq_work
*work
, void *data
)
3966 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
3968 return req
->user_data
== (unsigned long) data
;
3971 static int io_async_cancel_one(struct io_ring_ctx
*ctx
, void *sqe_addr
)
3973 enum io_wq_cancel cancel_ret
;
3976 cancel_ret
= io_wq_cancel_cb(ctx
->io_wq
, io_cancel_cb
, sqe_addr
);
3977 switch (cancel_ret
) {
3978 case IO_WQ_CANCEL_OK
:
3981 case IO_WQ_CANCEL_RUNNING
:
3984 case IO_WQ_CANCEL_NOTFOUND
:
3992 static void io_async_find_and_cancel(struct io_ring_ctx
*ctx
,
3993 struct io_kiocb
*req
, __u64 sqe_addr
,
3994 struct io_kiocb
**nxt
, int success_ret
)
3996 unsigned long flags
;
3999 ret
= io_async_cancel_one(ctx
, (void *) (unsigned long) sqe_addr
);
4000 if (ret
!= -ENOENT
) {
4001 spin_lock_irqsave(&ctx
->completion_lock
, flags
);
4005 spin_lock_irqsave(&ctx
->completion_lock
, flags
);
4006 ret
= io_timeout_cancel(ctx
, sqe_addr
);
4009 ret
= io_poll_cancel(ctx
, sqe_addr
);
4013 io_cqring_fill_event(req
, ret
);
4014 io_commit_cqring(ctx
);
4015 spin_unlock_irqrestore(&ctx
->completion_lock
, flags
);
4016 io_cqring_ev_posted(ctx
);
4019 req_set_fail_links(req
);
4020 io_put_req_find_next(req
, nxt
);
4023 static int io_async_cancel_prep(struct io_kiocb
*req
,
4024 const struct io_uring_sqe
*sqe
)
4026 if (unlikely(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
4028 if (sqe
->flags
|| sqe
->ioprio
|| sqe
->off
|| sqe
->len
||
4032 req
->cancel
.addr
= READ_ONCE(sqe
->addr
);
4036 static int io_async_cancel(struct io_kiocb
*req
, struct io_kiocb
**nxt
)
4038 struct io_ring_ctx
*ctx
= req
->ctx
;
4040 io_async_find_and_cancel(ctx
, req
, req
->cancel
.addr
, nxt
, 0);
4044 static int io_files_update_prep(struct io_kiocb
*req
,
4045 const struct io_uring_sqe
*sqe
)
4047 if (sqe
->flags
|| sqe
->ioprio
|| sqe
->rw_flags
)
4050 req
->files_update
.offset
= READ_ONCE(sqe
->off
);
4051 req
->files_update
.nr_args
= READ_ONCE(sqe
->len
);
4052 if (!req
->files_update
.nr_args
)
4054 req
->files_update
.arg
= READ_ONCE(sqe
->addr
);
4058 static int io_files_update(struct io_kiocb
*req
, bool force_nonblock
)
4060 struct io_ring_ctx
*ctx
= req
->ctx
;
4061 struct io_uring_files_update up
;
4067 up
.offset
= req
->files_update
.offset
;
4068 up
.fds
= req
->files_update
.arg
;
4070 mutex_lock(&ctx
->uring_lock
);
4071 ret
= __io_sqe_files_update(ctx
, &up
, req
->files_update
.nr_args
);
4072 mutex_unlock(&ctx
->uring_lock
);
4075 req_set_fail_links(req
);
4076 io_cqring_add_event(req
, ret
);
4081 static int io_req_defer_prep(struct io_kiocb
*req
,
4082 const struct io_uring_sqe
*sqe
)
4086 if (io_op_defs
[req
->opcode
].file_table
) {
4087 ret
= io_grab_files(req
);
4092 io_req_work_grab_env(req
, &io_op_defs
[req
->opcode
]);
4094 switch (req
->opcode
) {
4097 case IORING_OP_READV
:
4098 case IORING_OP_READ_FIXED
:
4099 case IORING_OP_READ
:
4100 ret
= io_read_prep(req
, sqe
, true);
4102 case IORING_OP_WRITEV
:
4103 case IORING_OP_WRITE_FIXED
:
4104 case IORING_OP_WRITE
:
4105 ret
= io_write_prep(req
, sqe
, true);
4107 case IORING_OP_POLL_ADD
:
4108 ret
= io_poll_add_prep(req
, sqe
);
4110 case IORING_OP_POLL_REMOVE
:
4111 ret
= io_poll_remove_prep(req
, sqe
);
4113 case IORING_OP_FSYNC
:
4114 ret
= io_prep_fsync(req
, sqe
);
4116 case IORING_OP_SYNC_FILE_RANGE
:
4117 ret
= io_prep_sfr(req
, sqe
);
4119 case IORING_OP_SENDMSG
:
4120 case IORING_OP_SEND
:
4121 ret
= io_sendmsg_prep(req
, sqe
);
4123 case IORING_OP_RECVMSG
:
4124 case IORING_OP_RECV
:
4125 ret
= io_recvmsg_prep(req
, sqe
);
4127 case IORING_OP_CONNECT
:
4128 ret
= io_connect_prep(req
, sqe
);
4130 case IORING_OP_TIMEOUT
:
4131 ret
= io_timeout_prep(req
, sqe
, false);
4133 case IORING_OP_TIMEOUT_REMOVE
:
4134 ret
= io_timeout_remove_prep(req
, sqe
);
4136 case IORING_OP_ASYNC_CANCEL
:
4137 ret
= io_async_cancel_prep(req
, sqe
);
4139 case IORING_OP_LINK_TIMEOUT
:
4140 ret
= io_timeout_prep(req
, sqe
, true);
4142 case IORING_OP_ACCEPT
:
4143 ret
= io_accept_prep(req
, sqe
);
4145 case IORING_OP_FALLOCATE
:
4146 ret
= io_fallocate_prep(req
, sqe
);
4148 case IORING_OP_OPENAT
:
4149 ret
= io_openat_prep(req
, sqe
);
4151 case IORING_OP_CLOSE
:
4152 ret
= io_close_prep(req
, sqe
);
4154 case IORING_OP_FILES_UPDATE
:
4155 ret
= io_files_update_prep(req
, sqe
);
4157 case IORING_OP_STATX
:
4158 ret
= io_statx_prep(req
, sqe
);
4160 case IORING_OP_FADVISE
:
4161 ret
= io_fadvise_prep(req
, sqe
);
4163 case IORING_OP_MADVISE
:
4164 ret
= io_madvise_prep(req
, sqe
);
4166 case IORING_OP_OPENAT2
:
4167 ret
= io_openat2_prep(req
, sqe
);
4169 case IORING_OP_EPOLL_CTL
:
4170 ret
= io_epoll_ctl_prep(req
, sqe
);
4173 printk_once(KERN_WARNING
"io_uring: unhandled opcode %d\n",
4182 static int io_req_defer(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
4184 struct io_ring_ctx
*ctx
= req
->ctx
;
4187 /* Still need defer if there is pending req in defer list. */
4188 if (!req_need_defer(req
) && list_empty(&ctx
->defer_list
))
4191 if (!req
->io
&& io_alloc_async_ctx(req
))
4194 ret
= io_req_defer_prep(req
, sqe
);
4198 spin_lock_irq(&ctx
->completion_lock
);
4199 if (!req_need_defer(req
) && list_empty(&ctx
->defer_list
)) {
4200 spin_unlock_irq(&ctx
->completion_lock
);
4204 trace_io_uring_defer(ctx
, req
, req
->user_data
);
4205 list_add_tail(&req
->list
, &ctx
->defer_list
);
4206 spin_unlock_irq(&ctx
->completion_lock
);
4207 return -EIOCBQUEUED
;
4210 static int io_issue_sqe(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
,
4211 struct io_kiocb
**nxt
, bool force_nonblock
)
4213 struct io_ring_ctx
*ctx
= req
->ctx
;
4216 switch (req
->opcode
) {
4220 case IORING_OP_READV
:
4221 case IORING_OP_READ_FIXED
:
4222 case IORING_OP_READ
:
4224 ret
= io_read_prep(req
, sqe
, force_nonblock
);
4228 ret
= io_read(req
, nxt
, force_nonblock
);
4230 case IORING_OP_WRITEV
:
4231 case IORING_OP_WRITE_FIXED
:
4232 case IORING_OP_WRITE
:
4234 ret
= io_write_prep(req
, sqe
, force_nonblock
);
4238 ret
= io_write(req
, nxt
, force_nonblock
);
4240 case IORING_OP_FSYNC
:
4242 ret
= io_prep_fsync(req
, sqe
);
4246 ret
= io_fsync(req
, nxt
, force_nonblock
);
4248 case IORING_OP_POLL_ADD
:
4250 ret
= io_poll_add_prep(req
, sqe
);
4254 ret
= io_poll_add(req
, nxt
);
4256 case IORING_OP_POLL_REMOVE
:
4258 ret
= io_poll_remove_prep(req
, sqe
);
4262 ret
= io_poll_remove(req
);
4264 case IORING_OP_SYNC_FILE_RANGE
:
4266 ret
= io_prep_sfr(req
, sqe
);
4270 ret
= io_sync_file_range(req
, nxt
, force_nonblock
);
4272 case IORING_OP_SENDMSG
:
4273 case IORING_OP_SEND
:
4275 ret
= io_sendmsg_prep(req
, sqe
);
4279 if (req
->opcode
== IORING_OP_SENDMSG
)
4280 ret
= io_sendmsg(req
, nxt
, force_nonblock
);
4282 ret
= io_send(req
, nxt
, force_nonblock
);
4284 case IORING_OP_RECVMSG
:
4285 case IORING_OP_RECV
:
4287 ret
= io_recvmsg_prep(req
, sqe
);
4291 if (req
->opcode
== IORING_OP_RECVMSG
)
4292 ret
= io_recvmsg(req
, nxt
, force_nonblock
);
4294 ret
= io_recv(req
, nxt
, force_nonblock
);
4296 case IORING_OP_TIMEOUT
:
4298 ret
= io_timeout_prep(req
, sqe
, false);
4302 ret
= io_timeout(req
);
4304 case IORING_OP_TIMEOUT_REMOVE
:
4306 ret
= io_timeout_remove_prep(req
, sqe
);
4310 ret
= io_timeout_remove(req
);
4312 case IORING_OP_ACCEPT
:
4314 ret
= io_accept_prep(req
, sqe
);
4318 ret
= io_accept(req
, nxt
, force_nonblock
);
4320 case IORING_OP_CONNECT
:
4322 ret
= io_connect_prep(req
, sqe
);
4326 ret
= io_connect(req
, nxt
, force_nonblock
);
4328 case IORING_OP_ASYNC_CANCEL
:
4330 ret
= io_async_cancel_prep(req
, sqe
);
4334 ret
= io_async_cancel(req
, nxt
);
4336 case IORING_OP_FALLOCATE
:
4338 ret
= io_fallocate_prep(req
, sqe
);
4342 ret
= io_fallocate(req
, nxt
, force_nonblock
);
4344 case IORING_OP_OPENAT
:
4346 ret
= io_openat_prep(req
, sqe
);
4350 ret
= io_openat(req
, nxt
, force_nonblock
);
4352 case IORING_OP_CLOSE
:
4354 ret
= io_close_prep(req
, sqe
);
4358 ret
= io_close(req
, nxt
, force_nonblock
);
4360 case IORING_OP_FILES_UPDATE
:
4362 ret
= io_files_update_prep(req
, sqe
);
4366 ret
= io_files_update(req
, force_nonblock
);
4368 case IORING_OP_STATX
:
4370 ret
= io_statx_prep(req
, sqe
);
4374 ret
= io_statx(req
, nxt
, force_nonblock
);
4376 case IORING_OP_FADVISE
:
4378 ret
= io_fadvise_prep(req
, sqe
);
4382 ret
= io_fadvise(req
, nxt
, force_nonblock
);
4384 case IORING_OP_MADVISE
:
4386 ret
= io_madvise_prep(req
, sqe
);
4390 ret
= io_madvise(req
, nxt
, force_nonblock
);
4392 case IORING_OP_OPENAT2
:
4394 ret
= io_openat2_prep(req
, sqe
);
4398 ret
= io_openat2(req
, nxt
, force_nonblock
);
4400 case IORING_OP_EPOLL_CTL
:
4402 ret
= io_epoll_ctl_prep(req
, sqe
);
4406 ret
= io_epoll_ctl(req
, nxt
, force_nonblock
);
4416 if (ctx
->flags
& IORING_SETUP_IOPOLL
) {
4417 const bool in_async
= io_wq_current_is_worker();
4419 if (req
->result
== -EAGAIN
)
4422 /* workqueue context doesn't hold uring_lock, grab it now */
4424 mutex_lock(&ctx
->uring_lock
);
4426 io_iopoll_req_issued(req
);
4429 mutex_unlock(&ctx
->uring_lock
);
4435 static void io_wq_submit_work(struct io_wq_work
**workptr
)
4437 struct io_wq_work
*work
= *workptr
;
4438 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
4439 struct io_kiocb
*nxt
= NULL
;
4442 /* if NO_CANCEL is set, we must still run the work */
4443 if ((work
->flags
& (IO_WQ_WORK_CANCEL
|IO_WQ_WORK_NO_CANCEL
)) ==
4444 IO_WQ_WORK_CANCEL
) {
4449 req
->has_user
= (work
->flags
& IO_WQ_WORK_HAS_MM
) != 0;
4450 req
->in_async
= true;
4452 ret
= io_issue_sqe(req
, NULL
, &nxt
, false);
4454 * We can get EAGAIN for polled IO even though we're
4455 * forcing a sync submission from here, since we can't
4456 * wait for request slots on the block side.
4464 /* drop submission reference */
4468 req_set_fail_links(req
);
4469 io_cqring_add_event(req
, ret
);
4473 /* if a dependent link is ready, pass it back */
4475 io_wq_assign_next(workptr
, nxt
);
4478 static int io_req_needs_file(struct io_kiocb
*req
, int fd
)
4480 if (!io_op_defs
[req
->opcode
].needs_file
)
4482 if (fd
== -1 && io_op_defs
[req
->opcode
].fd_non_neg
)
4487 static inline struct file
*io_file_from_index(struct io_ring_ctx
*ctx
,
4490 struct fixed_file_table
*table
;
4492 table
= &ctx
->file_data
->table
[index
>> IORING_FILE_TABLE_SHIFT
];
4493 return table
->files
[index
& IORING_FILE_TABLE_MASK
];;
4496 static int io_req_set_file(struct io_submit_state
*state
, struct io_kiocb
*req
,
4497 const struct io_uring_sqe
*sqe
)
4499 struct io_ring_ctx
*ctx
= req
->ctx
;
4503 flags
= READ_ONCE(sqe
->flags
);
4504 fd
= READ_ONCE(sqe
->fd
);
4506 if (!io_req_needs_file(req
, fd
))
4509 if (flags
& IOSQE_FIXED_FILE
) {
4510 if (unlikely(!ctx
->file_data
||
4511 (unsigned) fd
>= ctx
->nr_user_files
))
4513 fd
= array_index_nospec(fd
, ctx
->nr_user_files
);
4514 req
->file
= io_file_from_index(ctx
, fd
);
4517 req
->flags
|= REQ_F_FIXED_FILE
;
4518 percpu_ref_get(&ctx
->file_data
->refs
);
4520 if (req
->needs_fixed_file
)
4522 trace_io_uring_file_get(ctx
, fd
);
4523 req
->file
= io_file_get(state
, fd
);
4524 if (unlikely(!req
->file
))
4531 static int io_grab_files(struct io_kiocb
*req
)
4534 struct io_ring_ctx
*ctx
= req
->ctx
;
4536 if (req
->work
.files
)
4538 if (!ctx
->ring_file
)
4542 spin_lock_irq(&ctx
->inflight_lock
);
4544 * We use the f_ops->flush() handler to ensure that we can flush
4545 * out work accessing these files if the fd is closed. Check if
4546 * the fd has changed since we started down this path, and disallow
4547 * this operation if it has.
4549 if (fcheck(ctx
->ring_fd
) == ctx
->ring_file
) {
4550 list_add(&req
->inflight_entry
, &ctx
->inflight_list
);
4551 req
->flags
|= REQ_F_INFLIGHT
;
4552 req
->work
.files
= current
->files
;
4555 spin_unlock_irq(&ctx
->inflight_lock
);
4561 static enum hrtimer_restart
io_link_timeout_fn(struct hrtimer
*timer
)
4563 struct io_timeout_data
*data
= container_of(timer
,
4564 struct io_timeout_data
, timer
);
4565 struct io_kiocb
*req
= data
->req
;
4566 struct io_ring_ctx
*ctx
= req
->ctx
;
4567 struct io_kiocb
*prev
= NULL
;
4568 unsigned long flags
;
4570 spin_lock_irqsave(&ctx
->completion_lock
, flags
);
4573 * We don't expect the list to be empty, that will only happen if we
4574 * race with the completion of the linked work.
4576 if (!list_empty(&req
->link_list
)) {
4577 prev
= list_entry(req
->link_list
.prev
, struct io_kiocb
,
4579 if (refcount_inc_not_zero(&prev
->refs
)) {
4580 list_del_init(&req
->link_list
);
4581 prev
->flags
&= ~REQ_F_LINK_TIMEOUT
;
4586 spin_unlock_irqrestore(&ctx
->completion_lock
, flags
);
4589 req_set_fail_links(prev
);
4590 io_async_find_and_cancel(ctx
, req
, prev
->user_data
, NULL
,
4594 io_cqring_add_event(req
, -ETIME
);
4597 return HRTIMER_NORESTART
;
4600 static void io_queue_linked_timeout(struct io_kiocb
*req
)
4602 struct io_ring_ctx
*ctx
= req
->ctx
;
4605 * If the list is now empty, then our linked request finished before
4606 * we got a chance to setup the timer
4608 spin_lock_irq(&ctx
->completion_lock
);
4609 if (!list_empty(&req
->link_list
)) {
4610 struct io_timeout_data
*data
= &req
->io
->timeout
;
4612 data
->timer
.function
= io_link_timeout_fn
;
4613 hrtimer_start(&data
->timer
, timespec64_to_ktime(data
->ts
),
4616 spin_unlock_irq(&ctx
->completion_lock
);
4618 /* drop submission reference */
4622 static struct io_kiocb
*io_prep_linked_timeout(struct io_kiocb
*req
)
4624 struct io_kiocb
*nxt
;
4626 if (!(req
->flags
& REQ_F_LINK
))
4629 nxt
= list_first_entry_or_null(&req
->link_list
, struct io_kiocb
,
4631 if (!nxt
|| nxt
->opcode
!= IORING_OP_LINK_TIMEOUT
)
4634 req
->flags
|= REQ_F_LINK_TIMEOUT
;
4638 static void __io_queue_sqe(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
4640 struct io_kiocb
*linked_timeout
;
4641 struct io_kiocb
*nxt
= NULL
;
4645 linked_timeout
= io_prep_linked_timeout(req
);
4647 ret
= io_issue_sqe(req
, sqe
, &nxt
, true);
4650 * We async punt it if the file wasn't marked NOWAIT, or if the file
4651 * doesn't support non-blocking read/write attempts
4653 if (ret
== -EAGAIN
&& (!(req
->flags
& REQ_F_NOWAIT
) ||
4654 (req
->flags
& REQ_F_MUST_PUNT
))) {
4656 if (io_op_defs
[req
->opcode
].file_table
) {
4657 ret
= io_grab_files(req
);
4663 * Queued up for async execution, worker will release
4664 * submit reference when the iocb is actually submitted.
4666 io_queue_async_work(req
);
4671 /* drop submission reference */
4674 if (linked_timeout
) {
4676 io_queue_linked_timeout(linked_timeout
);
4678 io_put_req(linked_timeout
);
4681 /* and drop final reference, if we failed */
4683 io_cqring_add_event(req
, ret
);
4684 req_set_fail_links(req
);
4692 if (req
->flags
& REQ_F_FORCE_ASYNC
)
4698 static void io_queue_sqe(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
)
4702 ret
= io_req_defer(req
, sqe
);
4704 if (ret
!= -EIOCBQUEUED
) {
4706 io_cqring_add_event(req
, ret
);
4707 req_set_fail_links(req
);
4708 io_double_put_req(req
);
4710 } else if (req
->flags
& REQ_F_FORCE_ASYNC
) {
4711 ret
= io_req_defer_prep(req
, sqe
);
4712 if (unlikely(ret
< 0))
4715 * Never try inline submit of IOSQE_ASYNC is set, go straight
4716 * to async execution.
4718 req
->work
.flags
|= IO_WQ_WORK_CONCURRENT
;
4719 io_queue_async_work(req
);
4721 __io_queue_sqe(req
, sqe
);
4725 static inline void io_queue_link_head(struct io_kiocb
*req
)
4727 if (unlikely(req
->flags
& REQ_F_FAIL_LINK
)) {
4728 io_cqring_add_event(req
, -ECANCELED
);
4729 io_double_put_req(req
);
4731 io_queue_sqe(req
, NULL
);
4734 #define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
4735 IOSQE_IO_HARDLINK | IOSQE_ASYNC)
4737 static bool io_submit_sqe(struct io_kiocb
*req
, const struct io_uring_sqe
*sqe
,
4738 struct io_submit_state
*state
, struct io_kiocb
**link
)
4740 const struct cred
*old_creds
= NULL
;
4741 struct io_ring_ctx
*ctx
= req
->ctx
;
4742 unsigned int sqe_flags
;
4745 sqe_flags
= READ_ONCE(sqe
->flags
);
4747 /* enforce forwards compatibility on users */
4748 if (unlikely(sqe_flags
& ~SQE_VALID_FLAGS
)) {
4753 id
= READ_ONCE(sqe
->personality
);
4755 const struct cred
*personality_creds
;
4757 personality_creds
= idr_find(&ctx
->personality_idr
, id
);
4758 if (unlikely(!personality_creds
)) {
4762 old_creds
= override_creds(personality_creds
);
4765 /* same numerical values with corresponding REQ_F_*, safe to copy */
4766 req
->flags
|= sqe_flags
& (IOSQE_IO_DRAIN
|IOSQE_IO_HARDLINK
|
4769 ret
= io_req_set_file(state
, req
, sqe
);
4770 if (unlikely(ret
)) {
4772 io_cqring_add_event(req
, ret
);
4773 io_double_put_req(req
);
4775 revert_creds(old_creds
);
4780 * If we already have a head request, queue this one for async
4781 * submittal once the head completes. If we don't have a head but
4782 * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
4783 * submitted sync once the chain is complete. If none of those
4784 * conditions are true (normal request), then just queue it.
4787 struct io_kiocb
*head
= *link
;
4790 * Taking sequential execution of a link, draining both sides
4791 * of the link also fullfils IOSQE_IO_DRAIN semantics for all
4792 * requests in the link. So, it drains the head and the
4793 * next after the link request. The last one is done via
4794 * drain_next flag to persist the effect across calls.
4796 if (sqe_flags
& IOSQE_IO_DRAIN
) {
4797 head
->flags
|= REQ_F_IO_DRAIN
;
4798 ctx
->drain_next
= 1;
4800 if (io_alloc_async_ctx(req
)) {
4805 ret
= io_req_defer_prep(req
, sqe
);
4807 /* fail even hard links since we don't submit */
4808 head
->flags
|= REQ_F_FAIL_LINK
;
4811 trace_io_uring_link(ctx
, req
, head
);
4812 list_add_tail(&req
->link_list
, &head
->link_list
);
4814 /* last request of a link, enqueue the link */
4815 if (!(sqe_flags
& (IOSQE_IO_LINK
|IOSQE_IO_HARDLINK
))) {
4816 io_queue_link_head(head
);
4820 if (unlikely(ctx
->drain_next
)) {
4821 req
->flags
|= REQ_F_IO_DRAIN
;
4822 req
->ctx
->drain_next
= 0;
4824 if (sqe_flags
& (IOSQE_IO_LINK
|IOSQE_IO_HARDLINK
)) {
4825 req
->flags
|= REQ_F_LINK
;
4826 INIT_LIST_HEAD(&req
->link_list
);
4827 ret
= io_req_defer_prep(req
, sqe
);
4829 req
->flags
|= REQ_F_FAIL_LINK
;
4832 io_queue_sqe(req
, sqe
);
4837 revert_creds(old_creds
);
4842 * Batched submission is done, ensure local IO is flushed out.
4844 static void io_submit_state_end(struct io_submit_state
*state
)
4846 blk_finish_plug(&state
->plug
);
4848 if (state
->free_reqs
)
4849 kmem_cache_free_bulk(req_cachep
, state
->free_reqs
, state
->reqs
);
4853 * Start submission side cache.
4855 static void io_submit_state_start(struct io_submit_state
*state
,
4856 unsigned int max_ios
)
4858 blk_start_plug(&state
->plug
);
4859 state
->free_reqs
= 0;
4861 state
->ios_left
= max_ios
;
4864 static void io_commit_sqring(struct io_ring_ctx
*ctx
)
4866 struct io_rings
*rings
= ctx
->rings
;
4869 * Ensure any loads from the SQEs are done at this point,
4870 * since once we write the new head, the application could
4871 * write new data to them.
4873 smp_store_release(&rings
->sq
.head
, ctx
->cached_sq_head
);
4877 * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory
4878 * that is mapped by userspace. This means that care needs to be taken to
4879 * ensure that reads are stable, as we cannot rely on userspace always
4880 * being a good citizen. If members of the sqe are validated and then later
4881 * used, it's important that those reads are done through READ_ONCE() to
4882 * prevent a re-load down the line.
4884 static bool io_get_sqring(struct io_ring_ctx
*ctx
, struct io_kiocb
*req
,
4885 const struct io_uring_sqe
**sqe_ptr
)
4887 u32
*sq_array
= ctx
->sq_array
;
4891 * The cached sq head (or cq tail) serves two purposes:
4893 * 1) allows us to batch the cost of updating the user visible
4895 * 2) allows the kernel side to track the head on its own, even
4896 * though the application is the one updating it.
4898 head
= READ_ONCE(sq_array
[ctx
->cached_sq_head
& ctx
->sq_mask
]);
4899 if (likely(head
< ctx
->sq_entries
)) {
4901 * All io need record the previous position, if LINK vs DARIN,
4902 * it can be used to mark the position of the first IO in the
4905 req
->sequence
= ctx
->cached_sq_head
;
4906 *sqe_ptr
= &ctx
->sq_sqes
[head
];
4907 req
->opcode
= READ_ONCE((*sqe_ptr
)->opcode
);
4908 req
->user_data
= READ_ONCE((*sqe_ptr
)->user_data
);
4909 ctx
->cached_sq_head
++;
4913 /* drop invalid entries */
4914 ctx
->cached_sq_head
++;
4915 ctx
->cached_sq_dropped
++;
4916 WRITE_ONCE(ctx
->rings
->sq_dropped
, ctx
->cached_sq_dropped
);
4920 static int io_submit_sqes(struct io_ring_ctx
*ctx
, unsigned int nr
,
4921 struct file
*ring_file
, int ring_fd
,
4922 struct mm_struct
**mm
, bool async
)
4924 struct io_submit_state state
, *statep
= NULL
;
4925 struct io_kiocb
*link
= NULL
;
4926 int i
, submitted
= 0;
4927 bool mm_fault
= false;
4929 /* if we have a backlog and couldn't flush it all, return BUSY */
4930 if (test_bit(0, &ctx
->sq_check_overflow
)) {
4931 if (!list_empty(&ctx
->cq_overflow_list
) &&
4932 !io_cqring_overflow_flush(ctx
, false))
4936 /* make sure SQ entry isn't read before tail */
4937 nr
= min3(nr
, ctx
->sq_entries
, io_sqring_entries(ctx
));
4939 if (!percpu_ref_tryget_many(&ctx
->refs
, nr
))
4942 if (nr
> IO_PLUG_THRESHOLD
) {
4943 io_submit_state_start(&state
, nr
);
4947 ctx
->ring_fd
= ring_fd
;
4948 ctx
->ring_file
= ring_file
;
4950 for (i
= 0; i
< nr
; i
++) {
4951 const struct io_uring_sqe
*sqe
;
4952 struct io_kiocb
*req
;
4954 req
= io_get_req(ctx
, statep
);
4955 if (unlikely(!req
)) {
4957 submitted
= -EAGAIN
;
4960 if (!io_get_sqring(ctx
, req
, &sqe
)) {
4961 __io_req_do_free(req
);
4965 /* will complete beyond this point, count as submitted */
4968 if (unlikely(req
->opcode
>= IORING_OP_LAST
)) {
4969 io_cqring_add_event(req
, -EINVAL
);
4970 io_double_put_req(req
);
4974 if (io_op_defs
[req
->opcode
].needs_mm
&& !*mm
) {
4975 mm_fault
= mm_fault
|| !mmget_not_zero(ctx
->sqo_mm
);
4977 use_mm(ctx
->sqo_mm
);
4982 req
->has_user
= *mm
!= NULL
;
4983 req
->in_async
= async
;
4984 req
->needs_fixed_file
= async
;
4985 trace_io_uring_submit_sqe(ctx
, req
->opcode
, req
->user_data
,
4987 if (!io_submit_sqe(req
, sqe
, statep
, &link
))
4991 if (unlikely(submitted
!= nr
)) {
4992 int ref_used
= (submitted
== -EAGAIN
) ? 0 : submitted
;
4994 percpu_ref_put_many(&ctx
->refs
, nr
- ref_used
);
4997 io_queue_link_head(link
);
4999 io_submit_state_end(&state
);
5001 /* Commit SQ ring head once we've consumed and submitted all SQEs */
5002 io_commit_sqring(ctx
);
5007 static int io_sq_thread(void *data
)
5009 struct io_ring_ctx
*ctx
= data
;
5010 struct mm_struct
*cur_mm
= NULL
;
5011 const struct cred
*old_cred
;
5012 mm_segment_t old_fs
;
5015 unsigned long timeout
;
5018 complete(&ctx
->completions
[1]);
5022 old_cred
= override_creds(ctx
->creds
);
5024 ret
= timeout
= inflight
= 0;
5025 while (!kthread_should_park()) {
5026 unsigned int to_submit
;
5029 unsigned nr_events
= 0;
5031 if (ctx
->flags
& IORING_SETUP_IOPOLL
) {
5033 * inflight is the count of the maximum possible
5034 * entries we submitted, but it can be smaller
5035 * if we dropped some of them. If we don't have
5036 * poll entries available, then we know that we
5037 * have nothing left to poll for. Reset the
5038 * inflight count to zero in that case.
5040 mutex_lock(&ctx
->uring_lock
);
5041 if (!list_empty(&ctx
->poll_list
))
5042 __io_iopoll_check(ctx
, &nr_events
, 0);
5045 mutex_unlock(&ctx
->uring_lock
);
5048 * Normal IO, just pretend everything completed.
5049 * We don't have to poll completions for that.
5051 nr_events
= inflight
;
5054 inflight
-= nr_events
;
5056 timeout
= jiffies
+ ctx
->sq_thread_idle
;
5059 to_submit
= io_sqring_entries(ctx
);
5062 * If submit got -EBUSY, flag us as needing the application
5063 * to enter the kernel to reap and flush events.
5065 if (!to_submit
|| ret
== -EBUSY
) {
5067 * We're polling. If we're within the defined idle
5068 * period, then let us spin without work before going
5069 * to sleep. The exception is if we got EBUSY doing
5070 * more IO, we should wait for the application to
5071 * reap events and wake us up.
5074 (!time_after(jiffies
, timeout
) && ret
!= -EBUSY
&&
5075 !percpu_ref_is_dying(&ctx
->refs
))) {
5081 * Drop cur_mm before scheduling, we can't hold it for
5082 * long periods (or over schedule()). Do this before
5083 * adding ourselves to the waitqueue, as the unuse/drop
5092 prepare_to_wait(&ctx
->sqo_wait
, &wait
,
5093 TASK_INTERRUPTIBLE
);
5095 /* Tell userspace we may need a wakeup call */
5096 ctx
->rings
->sq_flags
|= IORING_SQ_NEED_WAKEUP
;
5097 /* make sure to read SQ tail after writing flags */
5100 to_submit
= io_sqring_entries(ctx
);
5101 if (!to_submit
|| ret
== -EBUSY
) {
5102 if (kthread_should_park()) {
5103 finish_wait(&ctx
->sqo_wait
, &wait
);
5106 if (signal_pending(current
))
5107 flush_signals(current
);
5109 finish_wait(&ctx
->sqo_wait
, &wait
);
5111 ctx
->rings
->sq_flags
&= ~IORING_SQ_NEED_WAKEUP
;
5114 finish_wait(&ctx
->sqo_wait
, &wait
);
5116 ctx
->rings
->sq_flags
&= ~IORING_SQ_NEED_WAKEUP
;
5119 mutex_lock(&ctx
->uring_lock
);
5120 ret
= io_submit_sqes(ctx
, to_submit
, NULL
, -1, &cur_mm
, true);
5121 mutex_unlock(&ctx
->uring_lock
);
5131 revert_creds(old_cred
);
5138 struct io_wait_queue
{
5139 struct wait_queue_entry wq
;
5140 struct io_ring_ctx
*ctx
;
5142 unsigned nr_timeouts
;
5145 static inline bool io_should_wake(struct io_wait_queue
*iowq
, bool noflush
)
5147 struct io_ring_ctx
*ctx
= iowq
->ctx
;
5150 * Wake up if we have enough events, or if a timeout occurred since we
5151 * started waiting. For timeouts, we always want to return to userspace,
5152 * regardless of event count.
5154 return io_cqring_events(ctx
, noflush
) >= iowq
->to_wait
||
5155 atomic_read(&ctx
->cq_timeouts
) != iowq
->nr_timeouts
;
5158 static int io_wake_function(struct wait_queue_entry
*curr
, unsigned int mode
,
5159 int wake_flags
, void *key
)
5161 struct io_wait_queue
*iowq
= container_of(curr
, struct io_wait_queue
,
5164 /* use noflush == true, as we can't safely rely on locking context */
5165 if (!io_should_wake(iowq
, true))
5168 return autoremove_wake_function(curr
, mode
, wake_flags
, key
);
5172 * Wait until events become available, if we don't already have some. The
5173 * application must reap them itself, as they reside on the shared cq ring.
5175 static int io_cqring_wait(struct io_ring_ctx
*ctx
, int min_events
,
5176 const sigset_t __user
*sig
, size_t sigsz
)
5178 struct io_wait_queue iowq
= {
5181 .func
= io_wake_function
,
5182 .entry
= LIST_HEAD_INIT(iowq
.wq
.entry
),
5185 .to_wait
= min_events
,
5187 struct io_rings
*rings
= ctx
->rings
;
5190 if (io_cqring_events(ctx
, false) >= min_events
)
5194 #ifdef CONFIG_COMPAT
5195 if (in_compat_syscall())
5196 ret
= set_compat_user_sigmask((const compat_sigset_t __user
*)sig
,
5200 ret
= set_user_sigmask(sig
, sigsz
);
5206 iowq
.nr_timeouts
= atomic_read(&ctx
->cq_timeouts
);
5207 trace_io_uring_cqring_wait(ctx
, min_events
);
5209 prepare_to_wait_exclusive(&ctx
->wait
, &iowq
.wq
,
5210 TASK_INTERRUPTIBLE
);
5211 if (io_should_wake(&iowq
, false))
5214 if (signal_pending(current
)) {
5219 finish_wait(&ctx
->wait
, &iowq
.wq
);
5221 restore_saved_sigmask_unless(ret
== -EINTR
);
5223 return READ_ONCE(rings
->cq
.head
) == READ_ONCE(rings
->cq
.tail
) ? ret
: 0;
5226 static void __io_sqe_files_unregister(struct io_ring_ctx
*ctx
)
5228 #if defined(CONFIG_UNIX)
5229 if (ctx
->ring_sock
) {
5230 struct sock
*sock
= ctx
->ring_sock
->sk
;
5231 struct sk_buff
*skb
;
5233 while ((skb
= skb_dequeue(&sock
->sk_receive_queue
)) != NULL
)
5239 for (i
= 0; i
< ctx
->nr_user_files
; i
++) {
5242 file
= io_file_from_index(ctx
, i
);
5249 static void io_file_ref_kill(struct percpu_ref
*ref
)
5251 struct fixed_file_data
*data
;
5253 data
= container_of(ref
, struct fixed_file_data
, refs
);
5254 complete(&data
->done
);
5257 static int io_sqe_files_unregister(struct io_ring_ctx
*ctx
)
5259 struct fixed_file_data
*data
= ctx
->file_data
;
5260 unsigned nr_tables
, i
;
5265 percpu_ref_kill_and_confirm(&data
->refs
, io_file_ref_kill
);
5266 flush_work(&data
->ref_work
);
5267 wait_for_completion(&data
->done
);
5268 io_ring_file_ref_flush(data
);
5269 percpu_ref_exit(&data
->refs
);
5271 __io_sqe_files_unregister(ctx
);
5272 nr_tables
= DIV_ROUND_UP(ctx
->nr_user_files
, IORING_MAX_FILES_TABLE
);
5273 for (i
= 0; i
< nr_tables
; i
++)
5274 kfree(data
->table
[i
].files
);
5277 ctx
->file_data
= NULL
;
5278 ctx
->nr_user_files
= 0;
5282 static void io_sq_thread_stop(struct io_ring_ctx
*ctx
)
5284 if (ctx
->sqo_thread
) {
5285 wait_for_completion(&ctx
->completions
[1]);
5287 * The park is a bit of a work-around, without it we get
5288 * warning spews on shutdown with SQPOLL set and affinity
5289 * set to a single CPU.
5291 kthread_park(ctx
->sqo_thread
);
5292 kthread_stop(ctx
->sqo_thread
);
5293 ctx
->sqo_thread
= NULL
;
5297 static void io_finish_async(struct io_ring_ctx
*ctx
)
5299 io_sq_thread_stop(ctx
);
5302 io_wq_destroy(ctx
->io_wq
);
5307 #if defined(CONFIG_UNIX)
5309 * Ensure the UNIX gc is aware of our file set, so we are certain that
5310 * the io_uring can be safely unregistered on process exit, even if we have
5311 * loops in the file referencing.
5313 static int __io_sqe_files_scm(struct io_ring_ctx
*ctx
, int nr
, int offset
)
5315 struct sock
*sk
= ctx
->ring_sock
->sk
;
5316 struct scm_fp_list
*fpl
;
5317 struct sk_buff
*skb
;
5320 if (!capable(CAP_SYS_RESOURCE
) && !capable(CAP_SYS_ADMIN
)) {
5321 unsigned long inflight
= ctx
->user
->unix_inflight
+ nr
;
5323 if (inflight
> task_rlimit(current
, RLIMIT_NOFILE
))
5327 fpl
= kzalloc(sizeof(*fpl
), GFP_KERNEL
);
5331 skb
= alloc_skb(0, GFP_KERNEL
);
5340 fpl
->user
= get_uid(ctx
->user
);
5341 for (i
= 0; i
< nr
; i
++) {
5342 struct file
*file
= io_file_from_index(ctx
, i
+ offset
);
5346 fpl
->fp
[nr_files
] = get_file(file
);
5347 unix_inflight(fpl
->user
, fpl
->fp
[nr_files
]);
5352 fpl
->max
= SCM_MAX_FD
;
5353 fpl
->count
= nr_files
;
5354 UNIXCB(skb
).fp
= fpl
;
5355 skb
->destructor
= unix_destruct_scm
;
5356 refcount_add(skb
->truesize
, &sk
->sk_wmem_alloc
);
5357 skb_queue_head(&sk
->sk_receive_queue
, skb
);
5359 for (i
= 0; i
< nr_files
; i
++)
5370 * If UNIX sockets are enabled, fd passing can cause a reference cycle which
5371 * causes regular reference counting to break down. We rely on the UNIX
5372 * garbage collection to take care of this problem for us.
5374 static int io_sqe_files_scm(struct io_ring_ctx
*ctx
)
5376 unsigned left
, total
;
5380 left
= ctx
->nr_user_files
;
5382 unsigned this_files
= min_t(unsigned, left
, SCM_MAX_FD
);
5384 ret
= __io_sqe_files_scm(ctx
, this_files
, total
);
5388 total
+= this_files
;
5394 while (total
< ctx
->nr_user_files
) {
5395 struct file
*file
= io_file_from_index(ctx
, total
);
5405 static int io_sqe_files_scm(struct io_ring_ctx
*ctx
)
5411 static int io_sqe_alloc_file_tables(struct io_ring_ctx
*ctx
, unsigned nr_tables
,
5416 for (i
= 0; i
< nr_tables
; i
++) {
5417 struct fixed_file_table
*table
= &ctx
->file_data
->table
[i
];
5418 unsigned this_files
;
5420 this_files
= min(nr_files
, IORING_MAX_FILES_TABLE
);
5421 table
->files
= kcalloc(this_files
, sizeof(struct file
*),
5425 nr_files
-= this_files
;
5431 for (i
= 0; i
< nr_tables
; i
++) {
5432 struct fixed_file_table
*table
= &ctx
->file_data
->table
[i
];
5433 kfree(table
->files
);
5438 static void io_ring_file_put(struct io_ring_ctx
*ctx
, struct file
*file
)
5440 #if defined(CONFIG_UNIX)
5441 struct sock
*sock
= ctx
->ring_sock
->sk
;
5442 struct sk_buff_head list
, *head
= &sock
->sk_receive_queue
;
5443 struct sk_buff
*skb
;
5446 __skb_queue_head_init(&list
);
5449 * Find the skb that holds this file in its SCM_RIGHTS. When found,
5450 * remove this entry and rearrange the file array.
5452 skb
= skb_dequeue(head
);
5454 struct scm_fp_list
*fp
;
5456 fp
= UNIXCB(skb
).fp
;
5457 for (i
= 0; i
< fp
->count
; i
++) {
5460 if (fp
->fp
[i
] != file
)
5463 unix_notinflight(fp
->user
, fp
->fp
[i
]);
5464 left
= fp
->count
- 1 - i
;
5466 memmove(&fp
->fp
[i
], &fp
->fp
[i
+ 1],
5467 left
* sizeof(struct file
*));
5474 __skb_queue_tail(&list
, skb
);
5484 __skb_queue_tail(&list
, skb
);
5486 skb
= skb_dequeue(head
);
5489 if (skb_peek(&list
)) {
5490 spin_lock_irq(&head
->lock
);
5491 while ((skb
= __skb_dequeue(&list
)) != NULL
)
5492 __skb_queue_tail(head
, skb
);
5493 spin_unlock_irq(&head
->lock
);
5500 struct io_file_put
{
5501 struct llist_node llist
;
5503 struct completion
*done
;
5506 static void io_ring_file_ref_flush(struct fixed_file_data
*data
)
5508 struct io_file_put
*pfile
, *tmp
;
5509 struct llist_node
*node
;
5511 while ((node
= llist_del_all(&data
->put_llist
)) != NULL
) {
5512 llist_for_each_entry_safe(pfile
, tmp
, node
, llist
) {
5513 io_ring_file_put(data
->ctx
, pfile
->file
);
5515 complete(pfile
->done
);
5522 static void io_ring_file_ref_switch(struct work_struct
*work
)
5524 struct fixed_file_data
*data
;
5526 data
= container_of(work
, struct fixed_file_data
, ref_work
);
5527 io_ring_file_ref_flush(data
);
5528 percpu_ref_get(&data
->refs
);
5529 percpu_ref_switch_to_percpu(&data
->refs
);
5532 static void io_file_data_ref_zero(struct percpu_ref
*ref
)
5534 struct fixed_file_data
*data
;
5536 data
= container_of(ref
, struct fixed_file_data
, refs
);
5539 * We can't safely switch from inside this context, punt to wq. If
5540 * the table ref is going away, the table is being unregistered.
5541 * Don't queue up the async work for that case, the caller will
5544 if (!percpu_ref_is_dying(&data
->refs
))
5545 queue_work(system_wq
, &data
->ref_work
);
5548 static int io_sqe_files_register(struct io_ring_ctx
*ctx
, void __user
*arg
,
5551 __s32 __user
*fds
= (__s32 __user
*) arg
;
5561 if (nr_args
> IORING_MAX_FIXED_FILES
)
5564 ctx
->file_data
= kzalloc(sizeof(*ctx
->file_data
), GFP_KERNEL
);
5565 if (!ctx
->file_data
)
5567 ctx
->file_data
->ctx
= ctx
;
5568 init_completion(&ctx
->file_data
->done
);
5570 nr_tables
= DIV_ROUND_UP(nr_args
, IORING_MAX_FILES_TABLE
);
5571 ctx
->file_data
->table
= kcalloc(nr_tables
,
5572 sizeof(struct fixed_file_table
),
5574 if (!ctx
->file_data
->table
) {
5575 kfree(ctx
->file_data
);
5576 ctx
->file_data
= NULL
;
5580 if (percpu_ref_init(&ctx
->file_data
->refs
, io_file_data_ref_zero
,
5581 PERCPU_REF_ALLOW_REINIT
, GFP_KERNEL
)) {
5582 kfree(ctx
->file_data
->table
);
5583 kfree(ctx
->file_data
);
5584 ctx
->file_data
= NULL
;
5587 ctx
->file_data
->put_llist
.first
= NULL
;
5588 INIT_WORK(&ctx
->file_data
->ref_work
, io_ring_file_ref_switch
);
5590 if (io_sqe_alloc_file_tables(ctx
, nr_tables
, nr_args
)) {
5591 percpu_ref_exit(&ctx
->file_data
->refs
);
5592 kfree(ctx
->file_data
->table
);
5593 kfree(ctx
->file_data
);
5594 ctx
->file_data
= NULL
;
5598 for (i
= 0; i
< nr_args
; i
++, ctx
->nr_user_files
++) {
5599 struct fixed_file_table
*table
;
5603 if (copy_from_user(&fd
, &fds
[i
], sizeof(fd
)))
5605 /* allow sparse sets */
5611 table
= &ctx
->file_data
->table
[i
>> IORING_FILE_TABLE_SHIFT
];
5612 index
= i
& IORING_FILE_TABLE_MASK
;
5620 * Don't allow io_uring instances to be registered. If UNIX
5621 * isn't enabled, then this causes a reference cycle and this
5622 * instance can never get freed. If UNIX is enabled we'll
5623 * handle it just fine, but there's still no point in allowing
5624 * a ring fd as it doesn't support regular read/write anyway.
5626 if (file
->f_op
== &io_uring_fops
) {
5631 table
->files
[index
] = file
;
5635 for (i
= 0; i
< ctx
->nr_user_files
; i
++) {
5636 file
= io_file_from_index(ctx
, i
);
5640 for (i
= 0; i
< nr_tables
; i
++)
5641 kfree(ctx
->file_data
->table
[i
].files
);
5643 kfree(ctx
->file_data
->table
);
5644 kfree(ctx
->file_data
);
5645 ctx
->file_data
= NULL
;
5646 ctx
->nr_user_files
= 0;
5650 ret
= io_sqe_files_scm(ctx
);
5652 io_sqe_files_unregister(ctx
);
5657 static int io_sqe_file_register(struct io_ring_ctx
*ctx
, struct file
*file
,
5660 #if defined(CONFIG_UNIX)
5661 struct sock
*sock
= ctx
->ring_sock
->sk
;
5662 struct sk_buff_head
*head
= &sock
->sk_receive_queue
;
5663 struct sk_buff
*skb
;
5666 * See if we can merge this file into an existing skb SCM_RIGHTS
5667 * file set. If there's no room, fall back to allocating a new skb
5668 * and filling it in.
5670 spin_lock_irq(&head
->lock
);
5671 skb
= skb_peek(head
);
5673 struct scm_fp_list
*fpl
= UNIXCB(skb
).fp
;
5675 if (fpl
->count
< SCM_MAX_FD
) {
5676 __skb_unlink(skb
, head
);
5677 spin_unlock_irq(&head
->lock
);
5678 fpl
->fp
[fpl
->count
] = get_file(file
);
5679 unix_inflight(fpl
->user
, fpl
->fp
[fpl
->count
]);
5681 spin_lock_irq(&head
->lock
);
5682 __skb_queue_head(head
, skb
);
5687 spin_unlock_irq(&head
->lock
);
5694 return __io_sqe_files_scm(ctx
, 1, index
);
5700 static void io_atomic_switch(struct percpu_ref
*ref
)
5702 struct fixed_file_data
*data
;
5704 data
= container_of(ref
, struct fixed_file_data
, refs
);
5705 clear_bit(FFD_F_ATOMIC
, &data
->state
);
5708 static bool io_queue_file_removal(struct fixed_file_data
*data
,
5711 struct io_file_put
*pfile
, pfile_stack
;
5712 DECLARE_COMPLETION_ONSTACK(done
);
5715 * If we fail allocating the struct we need for doing async reomval
5716 * of this file, just punt to sync and wait for it.
5718 pfile
= kzalloc(sizeof(*pfile
), GFP_KERNEL
);
5720 pfile
= &pfile_stack
;
5721 pfile
->done
= &done
;
5725 llist_add(&pfile
->llist
, &data
->put_llist
);
5727 if (pfile
== &pfile_stack
) {
5728 if (!test_and_set_bit(FFD_F_ATOMIC
, &data
->state
)) {
5729 percpu_ref_put(&data
->refs
);
5730 percpu_ref_switch_to_atomic(&data
->refs
,
5733 wait_for_completion(&done
);
5734 flush_work(&data
->ref_work
);
5741 static int __io_sqe_files_update(struct io_ring_ctx
*ctx
,
5742 struct io_uring_files_update
*up
,
5745 struct fixed_file_data
*data
= ctx
->file_data
;
5746 bool ref_switch
= false;
5752 if (check_add_overflow(up
->offset
, nr_args
, &done
))
5754 if (done
> ctx
->nr_user_files
)
5758 fds
= u64_to_user_ptr(up
->fds
);
5760 struct fixed_file_table
*table
;
5764 if (copy_from_user(&fd
, &fds
[done
], sizeof(fd
))) {
5768 i
= array_index_nospec(up
->offset
, ctx
->nr_user_files
);
5769 table
= &ctx
->file_data
->table
[i
>> IORING_FILE_TABLE_SHIFT
];
5770 index
= i
& IORING_FILE_TABLE_MASK
;
5771 if (table
->files
[index
]) {
5772 file
= io_file_from_index(ctx
, index
);
5773 table
->files
[index
] = NULL
;
5774 if (io_queue_file_removal(data
, file
))
5784 * Don't allow io_uring instances to be registered. If
5785 * UNIX isn't enabled, then this causes a reference
5786 * cycle and this instance can never get freed. If UNIX
5787 * is enabled we'll handle it just fine, but there's
5788 * still no point in allowing a ring fd as it doesn't
5789 * support regular read/write anyway.
5791 if (file
->f_op
== &io_uring_fops
) {
5796 table
->files
[index
] = file
;
5797 err
= io_sqe_file_register(ctx
, file
, i
);
5806 if (ref_switch
&& !test_and_set_bit(FFD_F_ATOMIC
, &data
->state
)) {
5807 percpu_ref_put(&data
->refs
);
5808 percpu_ref_switch_to_atomic(&data
->refs
, io_atomic_switch
);
5811 return done
? done
: err
;
5813 static int io_sqe_files_update(struct io_ring_ctx
*ctx
, void __user
*arg
,
5816 struct io_uring_files_update up
;
5818 if (!ctx
->file_data
)
5822 if (copy_from_user(&up
, arg
, sizeof(up
)))
5827 return __io_sqe_files_update(ctx
, &up
, nr_args
);
5830 static void io_put_work(struct io_wq_work
*work
)
5832 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
5837 static void io_get_work(struct io_wq_work
*work
)
5839 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
5841 refcount_inc(&req
->refs
);
5844 static int io_init_wq_offload(struct io_ring_ctx
*ctx
,
5845 struct io_uring_params
*p
)
5847 struct io_wq_data data
;
5849 struct io_ring_ctx
*ctx_attach
;
5850 unsigned int concurrency
;
5853 data
.user
= ctx
->user
;
5854 data
.get_work
= io_get_work
;
5855 data
.put_work
= io_put_work
;
5857 if (!(p
->flags
& IORING_SETUP_ATTACH_WQ
)) {
5858 /* Do QD, or 4 * CPUS, whatever is smallest */
5859 concurrency
= min(ctx
->sq_entries
, 4 * num_online_cpus());
5861 ctx
->io_wq
= io_wq_create(concurrency
, &data
);
5862 if (IS_ERR(ctx
->io_wq
)) {
5863 ret
= PTR_ERR(ctx
->io_wq
);
5869 f
= fdget(p
->wq_fd
);
5873 if (f
.file
->f_op
!= &io_uring_fops
) {
5878 ctx_attach
= f
.file
->private_data
;
5879 /* @io_wq is protected by holding the fd */
5880 if (!io_wq_get(ctx_attach
->io_wq
, &data
)) {
5885 ctx
->io_wq
= ctx_attach
->io_wq
;
5891 static int io_sq_offload_start(struct io_ring_ctx
*ctx
,
5892 struct io_uring_params
*p
)
5896 init_waitqueue_head(&ctx
->sqo_wait
);
5897 mmgrab(current
->mm
);
5898 ctx
->sqo_mm
= current
->mm
;
5900 if (ctx
->flags
& IORING_SETUP_SQPOLL
) {
5902 if (!capable(CAP_SYS_ADMIN
))
5905 ctx
->sq_thread_idle
= msecs_to_jiffies(p
->sq_thread_idle
);
5906 if (!ctx
->sq_thread_idle
)
5907 ctx
->sq_thread_idle
= HZ
;
5909 if (p
->flags
& IORING_SETUP_SQ_AFF
) {
5910 int cpu
= p
->sq_thread_cpu
;
5913 if (cpu
>= nr_cpu_ids
)
5915 if (!cpu_online(cpu
))
5918 ctx
->sqo_thread
= kthread_create_on_cpu(io_sq_thread
,
5922 ctx
->sqo_thread
= kthread_create(io_sq_thread
, ctx
,
5925 if (IS_ERR(ctx
->sqo_thread
)) {
5926 ret
= PTR_ERR(ctx
->sqo_thread
);
5927 ctx
->sqo_thread
= NULL
;
5930 wake_up_process(ctx
->sqo_thread
);
5931 } else if (p
->flags
& IORING_SETUP_SQ_AFF
) {
5932 /* Can't have SQ_AFF without SQPOLL */
5937 ret
= io_init_wq_offload(ctx
, p
);
5943 io_finish_async(ctx
);
5944 mmdrop(ctx
->sqo_mm
);
5949 static void io_unaccount_mem(struct user_struct
*user
, unsigned long nr_pages
)
5951 atomic_long_sub(nr_pages
, &user
->locked_vm
);
5954 static int io_account_mem(struct user_struct
*user
, unsigned long nr_pages
)
5956 unsigned long page_limit
, cur_pages
, new_pages
;
5958 /* Don't allow more pages than we can safely lock */
5959 page_limit
= rlimit(RLIMIT_MEMLOCK
) >> PAGE_SHIFT
;
5962 cur_pages
= atomic_long_read(&user
->locked_vm
);
5963 new_pages
= cur_pages
+ nr_pages
;
5964 if (new_pages
> page_limit
)
5966 } while (atomic_long_cmpxchg(&user
->locked_vm
, cur_pages
,
5967 new_pages
) != cur_pages
);
5972 static void io_mem_free(void *ptr
)
5979 page
= virt_to_head_page(ptr
);
5980 if (put_page_testzero(page
))
5981 free_compound_page(page
);
5984 static void *io_mem_alloc(size_t size
)
5986 gfp_t gfp_flags
= GFP_KERNEL
| __GFP_ZERO
| __GFP_NOWARN
| __GFP_COMP
|
5989 return (void *) __get_free_pages(gfp_flags
, get_order(size
));
5992 static unsigned long rings_size(unsigned sq_entries
, unsigned cq_entries
,
5995 struct io_rings
*rings
;
5996 size_t off
, sq_array_size
;
5998 off
= struct_size(rings
, cqes
, cq_entries
);
5999 if (off
== SIZE_MAX
)
6003 off
= ALIGN(off
, SMP_CACHE_BYTES
);
6008 sq_array_size
= array_size(sizeof(u32
), sq_entries
);
6009 if (sq_array_size
== SIZE_MAX
)
6012 if (check_add_overflow(off
, sq_array_size
, &off
))
6021 static unsigned long ring_pages(unsigned sq_entries
, unsigned cq_entries
)
6025 pages
= (size_t)1 << get_order(
6026 rings_size(sq_entries
, cq_entries
, NULL
));
6027 pages
+= (size_t)1 << get_order(
6028 array_size(sizeof(struct io_uring_sqe
), sq_entries
));
6033 static int io_sqe_buffer_unregister(struct io_ring_ctx
*ctx
)
6037 if (!ctx
->user_bufs
)
6040 for (i
= 0; i
< ctx
->nr_user_bufs
; i
++) {
6041 struct io_mapped_ubuf
*imu
= &ctx
->user_bufs
[i
];
6043 for (j
= 0; j
< imu
->nr_bvecs
; j
++)
6044 unpin_user_page(imu
->bvec
[j
].bv_page
);
6046 if (ctx
->account_mem
)
6047 io_unaccount_mem(ctx
->user
, imu
->nr_bvecs
);
6052 kfree(ctx
->user_bufs
);
6053 ctx
->user_bufs
= NULL
;
6054 ctx
->nr_user_bufs
= 0;
6058 static int io_copy_iov(struct io_ring_ctx
*ctx
, struct iovec
*dst
,
6059 void __user
*arg
, unsigned index
)
6061 struct iovec __user
*src
;
6063 #ifdef CONFIG_COMPAT
6065 struct compat_iovec __user
*ciovs
;
6066 struct compat_iovec ciov
;
6068 ciovs
= (struct compat_iovec __user
*) arg
;
6069 if (copy_from_user(&ciov
, &ciovs
[index
], sizeof(ciov
)))
6072 dst
->iov_base
= u64_to_user_ptr((u64
)ciov
.iov_base
);
6073 dst
->iov_len
= ciov
.iov_len
;
6077 src
= (struct iovec __user
*) arg
;
6078 if (copy_from_user(dst
, &src
[index
], sizeof(*dst
)))
6083 static int io_sqe_buffer_register(struct io_ring_ctx
*ctx
, void __user
*arg
,
6086 struct vm_area_struct
**vmas
= NULL
;
6087 struct page
**pages
= NULL
;
6088 int i
, j
, got_pages
= 0;
6093 if (!nr_args
|| nr_args
> UIO_MAXIOV
)
6096 ctx
->user_bufs
= kcalloc(nr_args
, sizeof(struct io_mapped_ubuf
),
6098 if (!ctx
->user_bufs
)
6101 for (i
= 0; i
< nr_args
; i
++) {
6102 struct io_mapped_ubuf
*imu
= &ctx
->user_bufs
[i
];
6103 unsigned long off
, start
, end
, ubuf
;
6108 ret
= io_copy_iov(ctx
, &iov
, arg
, i
);
6113 * Don't impose further limits on the size and buffer
6114 * constraints here, we'll -EINVAL later when IO is
6115 * submitted if they are wrong.
6118 if (!iov
.iov_base
|| !iov
.iov_len
)
6121 /* arbitrary limit, but we need something */
6122 if (iov
.iov_len
> SZ_1G
)
6125 ubuf
= (unsigned long) iov
.iov_base
;
6126 end
= (ubuf
+ iov
.iov_len
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
6127 start
= ubuf
>> PAGE_SHIFT
;
6128 nr_pages
= end
- start
;
6130 if (ctx
->account_mem
) {
6131 ret
= io_account_mem(ctx
->user
, nr_pages
);
6137 if (!pages
|| nr_pages
> got_pages
) {
6140 pages
= kvmalloc_array(nr_pages
, sizeof(struct page
*),
6142 vmas
= kvmalloc_array(nr_pages
,
6143 sizeof(struct vm_area_struct
*),
6145 if (!pages
|| !vmas
) {
6147 if (ctx
->account_mem
)
6148 io_unaccount_mem(ctx
->user
, nr_pages
);
6151 got_pages
= nr_pages
;
6154 imu
->bvec
= kvmalloc_array(nr_pages
, sizeof(struct bio_vec
),
6158 if (ctx
->account_mem
)
6159 io_unaccount_mem(ctx
->user
, nr_pages
);
6164 down_read(¤t
->mm
->mmap_sem
);
6165 pret
= pin_user_pages(ubuf
, nr_pages
,
6166 FOLL_WRITE
| FOLL_LONGTERM
,
6168 if (pret
== nr_pages
) {
6169 /* don't support file backed memory */
6170 for (j
= 0; j
< nr_pages
; j
++) {
6171 struct vm_area_struct
*vma
= vmas
[j
];
6174 !is_file_hugepages(vma
->vm_file
)) {
6180 ret
= pret
< 0 ? pret
: -EFAULT
;
6182 up_read(¤t
->mm
->mmap_sem
);
6185 * if we did partial map, or found file backed vmas,
6186 * release any pages we did get
6189 unpin_user_pages(pages
, pret
);
6190 if (ctx
->account_mem
)
6191 io_unaccount_mem(ctx
->user
, nr_pages
);
6196 off
= ubuf
& ~PAGE_MASK
;
6198 for (j
= 0; j
< nr_pages
; j
++) {
6201 vec_len
= min_t(size_t, size
, PAGE_SIZE
- off
);
6202 imu
->bvec
[j
].bv_page
= pages
[j
];
6203 imu
->bvec
[j
].bv_len
= vec_len
;
6204 imu
->bvec
[j
].bv_offset
= off
;
6208 /* store original address for later verification */
6210 imu
->len
= iov
.iov_len
;
6211 imu
->nr_bvecs
= nr_pages
;
6213 ctx
->nr_user_bufs
++;
6221 io_sqe_buffer_unregister(ctx
);
6225 static int io_eventfd_register(struct io_ring_ctx
*ctx
, void __user
*arg
)
6227 __s32 __user
*fds
= arg
;
6233 if (copy_from_user(&fd
, fds
, sizeof(*fds
)))
6236 ctx
->cq_ev_fd
= eventfd_ctx_fdget(fd
);
6237 if (IS_ERR(ctx
->cq_ev_fd
)) {
6238 int ret
= PTR_ERR(ctx
->cq_ev_fd
);
6239 ctx
->cq_ev_fd
= NULL
;
6246 static int io_eventfd_unregister(struct io_ring_ctx
*ctx
)
6248 if (ctx
->cq_ev_fd
) {
6249 eventfd_ctx_put(ctx
->cq_ev_fd
);
6250 ctx
->cq_ev_fd
= NULL
;
6257 static void io_ring_ctx_free(struct io_ring_ctx
*ctx
)
6259 io_finish_async(ctx
);
6261 mmdrop(ctx
->sqo_mm
);
6263 io_iopoll_reap_events(ctx
);
6264 io_sqe_buffer_unregister(ctx
);
6265 io_sqe_files_unregister(ctx
);
6266 io_eventfd_unregister(ctx
);
6268 #if defined(CONFIG_UNIX)
6269 if (ctx
->ring_sock
) {
6270 ctx
->ring_sock
->file
= NULL
; /* so that iput() is called */
6271 sock_release(ctx
->ring_sock
);
6275 io_mem_free(ctx
->rings
);
6276 io_mem_free(ctx
->sq_sqes
);
6278 percpu_ref_exit(&ctx
->refs
);
6279 if (ctx
->account_mem
)
6280 io_unaccount_mem(ctx
->user
,
6281 ring_pages(ctx
->sq_entries
, ctx
->cq_entries
));
6282 free_uid(ctx
->user
);
6283 put_cred(ctx
->creds
);
6284 kfree(ctx
->completions
);
6285 kfree(ctx
->cancel_hash
);
6286 kmem_cache_free(req_cachep
, ctx
->fallback_req
);
6290 static __poll_t
io_uring_poll(struct file
*file
, poll_table
*wait
)
6292 struct io_ring_ctx
*ctx
= file
->private_data
;
6295 poll_wait(file
, &ctx
->cq_wait
, wait
);
6297 * synchronizes with barrier from wq_has_sleeper call in
6301 if (READ_ONCE(ctx
->rings
->sq
.tail
) - ctx
->cached_sq_head
!=
6302 ctx
->rings
->sq_ring_entries
)
6303 mask
|= EPOLLOUT
| EPOLLWRNORM
;
6304 if (READ_ONCE(ctx
->rings
->cq
.head
) != ctx
->cached_cq_tail
)
6305 mask
|= EPOLLIN
| EPOLLRDNORM
;
6310 static int io_uring_fasync(int fd
, struct file
*file
, int on
)
6312 struct io_ring_ctx
*ctx
= file
->private_data
;
6314 return fasync_helper(fd
, file
, on
, &ctx
->cq_fasync
);
6317 static int io_remove_personalities(int id
, void *p
, void *data
)
6319 struct io_ring_ctx
*ctx
= data
;
6320 const struct cred
*cred
;
6322 cred
= idr_remove(&ctx
->personality_idr
, id
);
6328 static void io_ring_ctx_wait_and_kill(struct io_ring_ctx
*ctx
)
6330 mutex_lock(&ctx
->uring_lock
);
6331 percpu_ref_kill(&ctx
->refs
);
6332 mutex_unlock(&ctx
->uring_lock
);
6335 * Wait for sq thread to idle, if we have one. It won't spin on new
6336 * work after we've killed the ctx ref above. This is important to do
6337 * before we cancel existing commands, as the thread could otherwise
6338 * be queueing new work post that. If that's work we need to cancel,
6339 * it could cause shutdown to hang.
6341 while (ctx
->sqo_thread
&& !wq_has_sleeper(&ctx
->sqo_wait
))
6344 io_kill_timeouts(ctx
);
6345 io_poll_remove_all(ctx
);
6348 io_wq_cancel_all(ctx
->io_wq
);
6350 io_iopoll_reap_events(ctx
);
6351 /* if we failed setting up the ctx, we might not have any rings */
6353 io_cqring_overflow_flush(ctx
, true);
6354 idr_for_each(&ctx
->personality_idr
, io_remove_personalities
, ctx
);
6355 wait_for_completion(&ctx
->completions
[0]);
6356 io_ring_ctx_free(ctx
);
6359 static int io_uring_release(struct inode
*inode
, struct file
*file
)
6361 struct io_ring_ctx
*ctx
= file
->private_data
;
6363 file
->private_data
= NULL
;
6364 io_ring_ctx_wait_and_kill(ctx
);
6368 static void io_uring_cancel_files(struct io_ring_ctx
*ctx
,
6369 struct files_struct
*files
)
6371 struct io_kiocb
*req
;
6374 while (!list_empty_careful(&ctx
->inflight_list
)) {
6375 struct io_kiocb
*cancel_req
= NULL
;
6377 spin_lock_irq(&ctx
->inflight_lock
);
6378 list_for_each_entry(req
, &ctx
->inflight_list
, inflight_entry
) {
6379 if (req
->work
.files
!= files
)
6381 /* req is being completed, ignore */
6382 if (!refcount_inc_not_zero(&req
->refs
))
6388 prepare_to_wait(&ctx
->inflight_wait
, &wait
,
6389 TASK_UNINTERRUPTIBLE
);
6390 spin_unlock_irq(&ctx
->inflight_lock
);
6392 /* We need to keep going until we don't find a matching req */
6396 io_wq_cancel_work(ctx
->io_wq
, &cancel_req
->work
);
6397 io_put_req(cancel_req
);
6400 finish_wait(&ctx
->inflight_wait
, &wait
);
6403 static int io_uring_flush(struct file
*file
, void *data
)
6405 struct io_ring_ctx
*ctx
= file
->private_data
;
6407 io_uring_cancel_files(ctx
, data
);
6411 static void *io_uring_validate_mmap_request(struct file
*file
,
6412 loff_t pgoff
, size_t sz
)
6414 struct io_ring_ctx
*ctx
= file
->private_data
;
6415 loff_t offset
= pgoff
<< PAGE_SHIFT
;
6420 case IORING_OFF_SQ_RING
:
6421 case IORING_OFF_CQ_RING
:
6424 case IORING_OFF_SQES
:
6428 return ERR_PTR(-EINVAL
);
6431 page
= virt_to_head_page(ptr
);
6432 if (sz
> page_size(page
))
6433 return ERR_PTR(-EINVAL
);
6440 static int io_uring_mmap(struct file
*file
, struct vm_area_struct
*vma
)
6442 size_t sz
= vma
->vm_end
- vma
->vm_start
;
6446 ptr
= io_uring_validate_mmap_request(file
, vma
->vm_pgoff
, sz
);
6448 return PTR_ERR(ptr
);
6450 pfn
= virt_to_phys(ptr
) >> PAGE_SHIFT
;
6451 return remap_pfn_range(vma
, vma
->vm_start
, pfn
, sz
, vma
->vm_page_prot
);
6454 #else /* !CONFIG_MMU */
6456 static int io_uring_mmap(struct file
*file
, struct vm_area_struct
*vma
)
6458 return vma
->vm_flags
& (VM_SHARED
| VM_MAYSHARE
) ? 0 : -EINVAL
;
6461 static unsigned int io_uring_nommu_mmap_capabilities(struct file
*file
)
6463 return NOMMU_MAP_DIRECT
| NOMMU_MAP_READ
| NOMMU_MAP_WRITE
;
6466 static unsigned long io_uring_nommu_get_unmapped_area(struct file
*file
,
6467 unsigned long addr
, unsigned long len
,
6468 unsigned long pgoff
, unsigned long flags
)
6472 ptr
= io_uring_validate_mmap_request(file
, pgoff
, len
);
6474 return PTR_ERR(ptr
);
6476 return (unsigned long) ptr
;
6479 #endif /* !CONFIG_MMU */
6481 SYSCALL_DEFINE6(io_uring_enter
, unsigned int, fd
, u32
, to_submit
,
6482 u32
, min_complete
, u32
, flags
, const sigset_t __user
*, sig
,
6485 struct io_ring_ctx
*ctx
;
6490 if (flags
& ~(IORING_ENTER_GETEVENTS
| IORING_ENTER_SQ_WAKEUP
))
6498 if (f
.file
->f_op
!= &io_uring_fops
)
6502 ctx
= f
.file
->private_data
;
6503 if (!percpu_ref_tryget(&ctx
->refs
))
6507 * For SQ polling, the thread will do all submissions and completions.
6508 * Just return the requested submit count, and wake the thread if
6512 if (ctx
->flags
& IORING_SETUP_SQPOLL
) {
6513 if (!list_empty_careful(&ctx
->cq_overflow_list
))
6514 io_cqring_overflow_flush(ctx
, false);
6515 if (flags
& IORING_ENTER_SQ_WAKEUP
)
6516 wake_up(&ctx
->sqo_wait
);
6517 submitted
= to_submit
;
6518 } else if (to_submit
) {
6519 struct mm_struct
*cur_mm
;
6521 mutex_lock(&ctx
->uring_lock
);
6522 /* already have mm, so io_submit_sqes() won't try to grab it */
6523 cur_mm
= ctx
->sqo_mm
;
6524 submitted
= io_submit_sqes(ctx
, to_submit
, f
.file
, fd
,
6526 mutex_unlock(&ctx
->uring_lock
);
6528 if (submitted
!= to_submit
)
6531 if (flags
& IORING_ENTER_GETEVENTS
) {
6532 unsigned nr_events
= 0;
6534 min_complete
= min(min_complete
, ctx
->cq_entries
);
6536 if (ctx
->flags
& IORING_SETUP_IOPOLL
) {
6537 ret
= io_iopoll_check(ctx
, &nr_events
, min_complete
);
6539 ret
= io_cqring_wait(ctx
, min_complete
, sig
, sigsz
);
6544 percpu_ref_put(&ctx
->refs
);
6547 return submitted
? submitted
: ret
;
6550 static int io_uring_show_cred(int id
, void *p
, void *data
)
6552 const struct cred
*cred
= p
;
6553 struct seq_file
*m
= data
;
6554 struct user_namespace
*uns
= seq_user_ns(m
);
6555 struct group_info
*gi
;
6560 seq_printf(m
, "%5d\n", id
);
6561 seq_put_decimal_ull(m
, "\tUid:\t", from_kuid_munged(uns
, cred
->uid
));
6562 seq_put_decimal_ull(m
, "\t\t", from_kuid_munged(uns
, cred
->euid
));
6563 seq_put_decimal_ull(m
, "\t\t", from_kuid_munged(uns
, cred
->suid
));
6564 seq_put_decimal_ull(m
, "\t\t", from_kuid_munged(uns
, cred
->fsuid
));
6565 seq_put_decimal_ull(m
, "\n\tGid:\t", from_kgid_munged(uns
, cred
->gid
));
6566 seq_put_decimal_ull(m
, "\t\t", from_kgid_munged(uns
, cred
->egid
));
6567 seq_put_decimal_ull(m
, "\t\t", from_kgid_munged(uns
, cred
->sgid
));
6568 seq_put_decimal_ull(m
, "\t\t", from_kgid_munged(uns
, cred
->fsgid
));
6569 seq_puts(m
, "\n\tGroups:\t");
6570 gi
= cred
->group_info
;
6571 for (g
= 0; g
< gi
->ngroups
; g
++) {
6572 seq_put_decimal_ull(m
, g
? " " : "",
6573 from_kgid_munged(uns
, gi
->gid
[g
]));
6575 seq_puts(m
, "\n\tCapEff:\t");
6576 cap
= cred
->cap_effective
;
6577 CAP_FOR_EACH_U32(__capi
)
6578 seq_put_hex_ll(m
, NULL
, cap
.cap
[CAP_LAST_U32
- __capi
], 8);
6583 static void __io_uring_show_fdinfo(struct io_ring_ctx
*ctx
, struct seq_file
*m
)
6587 mutex_lock(&ctx
->uring_lock
);
6588 seq_printf(m
, "UserFiles:\t%u\n", ctx
->nr_user_files
);
6589 for (i
= 0; i
< ctx
->nr_user_files
; i
++) {
6590 struct fixed_file_table
*table
;
6593 table
= &ctx
->file_data
->table
[i
>> IORING_FILE_TABLE_SHIFT
];
6594 f
= table
->files
[i
& IORING_FILE_TABLE_MASK
];
6596 seq_printf(m
, "%5u: %s\n", i
, file_dentry(f
)->d_iname
);
6598 seq_printf(m
, "%5u: <none>\n", i
);
6600 seq_printf(m
, "UserBufs:\t%u\n", ctx
->nr_user_bufs
);
6601 for (i
= 0; i
< ctx
->nr_user_bufs
; i
++) {
6602 struct io_mapped_ubuf
*buf
= &ctx
->user_bufs
[i
];
6604 seq_printf(m
, "%5u: 0x%llx/%u\n", i
, buf
->ubuf
,
6605 (unsigned int) buf
->len
);
6607 if (!idr_is_empty(&ctx
->personality_idr
)) {
6608 seq_printf(m
, "Personalities:\n");
6609 idr_for_each(&ctx
->personality_idr
, io_uring_show_cred
, m
);
6611 mutex_unlock(&ctx
->uring_lock
);
6614 static void io_uring_show_fdinfo(struct seq_file
*m
, struct file
*f
)
6616 struct io_ring_ctx
*ctx
= f
->private_data
;
6618 if (percpu_ref_tryget(&ctx
->refs
)) {
6619 __io_uring_show_fdinfo(ctx
, m
);
6620 percpu_ref_put(&ctx
->refs
);
6624 static const struct file_operations io_uring_fops
= {
6625 .release
= io_uring_release
,
6626 .flush
= io_uring_flush
,
6627 .mmap
= io_uring_mmap
,
6629 .get_unmapped_area
= io_uring_nommu_get_unmapped_area
,
6630 .mmap_capabilities
= io_uring_nommu_mmap_capabilities
,
6632 .poll
= io_uring_poll
,
6633 .fasync
= io_uring_fasync
,
6634 .show_fdinfo
= io_uring_show_fdinfo
,
6637 static int io_allocate_scq_urings(struct io_ring_ctx
*ctx
,
6638 struct io_uring_params
*p
)
6640 struct io_rings
*rings
;
6641 size_t size
, sq_array_offset
;
6643 size
= rings_size(p
->sq_entries
, p
->cq_entries
, &sq_array_offset
);
6644 if (size
== SIZE_MAX
)
6647 rings
= io_mem_alloc(size
);
6652 ctx
->sq_array
= (u32
*)((char *)rings
+ sq_array_offset
);
6653 rings
->sq_ring_mask
= p
->sq_entries
- 1;
6654 rings
->cq_ring_mask
= p
->cq_entries
- 1;
6655 rings
->sq_ring_entries
= p
->sq_entries
;
6656 rings
->cq_ring_entries
= p
->cq_entries
;
6657 ctx
->sq_mask
= rings
->sq_ring_mask
;
6658 ctx
->cq_mask
= rings
->cq_ring_mask
;
6659 ctx
->sq_entries
= rings
->sq_ring_entries
;
6660 ctx
->cq_entries
= rings
->cq_ring_entries
;
6662 size
= array_size(sizeof(struct io_uring_sqe
), p
->sq_entries
);
6663 if (size
== SIZE_MAX
) {
6664 io_mem_free(ctx
->rings
);
6669 ctx
->sq_sqes
= io_mem_alloc(size
);
6670 if (!ctx
->sq_sqes
) {
6671 io_mem_free(ctx
->rings
);
6680 * Allocate an anonymous fd, this is what constitutes the application
6681 * visible backing of an io_uring instance. The application mmaps this
6682 * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
6683 * we have to tie this fd to a socket for file garbage collection purposes.
6685 static int io_uring_get_fd(struct io_ring_ctx
*ctx
)
6690 #if defined(CONFIG_UNIX)
6691 ret
= sock_create_kern(&init_net
, PF_UNIX
, SOCK_RAW
, IPPROTO_IP
,
6697 ret
= get_unused_fd_flags(O_RDWR
| O_CLOEXEC
);
6701 file
= anon_inode_getfile("[io_uring]", &io_uring_fops
, ctx
,
6702 O_RDWR
| O_CLOEXEC
);
6705 ret
= PTR_ERR(file
);
6709 #if defined(CONFIG_UNIX)
6710 ctx
->ring_sock
->file
= file
;
6712 fd_install(ret
, file
);
6715 #if defined(CONFIG_UNIX)
6716 sock_release(ctx
->ring_sock
);
6717 ctx
->ring_sock
= NULL
;
6722 static int io_uring_create(unsigned entries
, struct io_uring_params
*p
)
6724 struct user_struct
*user
= NULL
;
6725 struct io_ring_ctx
*ctx
;
6731 if (entries
> IORING_MAX_ENTRIES
) {
6732 if (!(p
->flags
& IORING_SETUP_CLAMP
))
6734 entries
= IORING_MAX_ENTRIES
;
6738 * Use twice as many entries for the CQ ring. It's possible for the
6739 * application to drive a higher depth than the size of the SQ ring,
6740 * since the sqes are only used at submission time. This allows for
6741 * some flexibility in overcommitting a bit. If the application has
6742 * set IORING_SETUP_CQSIZE, it will have passed in the desired number
6743 * of CQ ring entries manually.
6745 p
->sq_entries
= roundup_pow_of_two(entries
);
6746 if (p
->flags
& IORING_SETUP_CQSIZE
) {
6748 * If IORING_SETUP_CQSIZE is set, we do the same roundup
6749 * to a power-of-two, if it isn't already. We do NOT impose
6750 * any cq vs sq ring sizing.
6752 if (p
->cq_entries
< p
->sq_entries
)
6754 if (p
->cq_entries
> IORING_MAX_CQ_ENTRIES
) {
6755 if (!(p
->flags
& IORING_SETUP_CLAMP
))
6757 p
->cq_entries
= IORING_MAX_CQ_ENTRIES
;
6759 p
->cq_entries
= roundup_pow_of_two(p
->cq_entries
);
6761 p
->cq_entries
= 2 * p
->sq_entries
;
6764 user
= get_uid(current_user());
6765 account_mem
= !capable(CAP_IPC_LOCK
);
6768 ret
= io_account_mem(user
,
6769 ring_pages(p
->sq_entries
, p
->cq_entries
));
6776 ctx
= io_ring_ctx_alloc(p
);
6779 io_unaccount_mem(user
, ring_pages(p
->sq_entries
,
6784 ctx
->compat
= in_compat_syscall();
6785 ctx
->account_mem
= account_mem
;
6787 ctx
->creds
= get_current_cred();
6789 ret
= io_allocate_scq_urings(ctx
, p
);
6793 ret
= io_sq_offload_start(ctx
, p
);
6797 memset(&p
->sq_off
, 0, sizeof(p
->sq_off
));
6798 p
->sq_off
.head
= offsetof(struct io_rings
, sq
.head
);
6799 p
->sq_off
.tail
= offsetof(struct io_rings
, sq
.tail
);
6800 p
->sq_off
.ring_mask
= offsetof(struct io_rings
, sq_ring_mask
);
6801 p
->sq_off
.ring_entries
= offsetof(struct io_rings
, sq_ring_entries
);
6802 p
->sq_off
.flags
= offsetof(struct io_rings
, sq_flags
);
6803 p
->sq_off
.dropped
= offsetof(struct io_rings
, sq_dropped
);
6804 p
->sq_off
.array
= (char *)ctx
->sq_array
- (char *)ctx
->rings
;
6806 memset(&p
->cq_off
, 0, sizeof(p
->cq_off
));
6807 p
->cq_off
.head
= offsetof(struct io_rings
, cq
.head
);
6808 p
->cq_off
.tail
= offsetof(struct io_rings
, cq
.tail
);
6809 p
->cq_off
.ring_mask
= offsetof(struct io_rings
, cq_ring_mask
);
6810 p
->cq_off
.ring_entries
= offsetof(struct io_rings
, cq_ring_entries
);
6811 p
->cq_off
.overflow
= offsetof(struct io_rings
, cq_overflow
);
6812 p
->cq_off
.cqes
= offsetof(struct io_rings
, cqes
);
6815 * Install ring fd as the very last thing, so we don't risk someone
6816 * having closed it before we finish setup
6818 ret
= io_uring_get_fd(ctx
);
6822 p
->features
= IORING_FEAT_SINGLE_MMAP
| IORING_FEAT_NODROP
|
6823 IORING_FEAT_SUBMIT_STABLE
| IORING_FEAT_RW_CUR_POS
|
6824 IORING_FEAT_CUR_PERSONALITY
;
6825 trace_io_uring_create(ret
, ctx
, p
->sq_entries
, p
->cq_entries
, p
->flags
);
6828 io_ring_ctx_wait_and_kill(ctx
);
6833 * Sets up an aio uring context, and returns the fd. Applications asks for a
6834 * ring size, we return the actual sq/cq ring sizes (among other things) in the
6835 * params structure passed in.
6837 static long io_uring_setup(u32 entries
, struct io_uring_params __user
*params
)
6839 struct io_uring_params p
;
6843 if (copy_from_user(&p
, params
, sizeof(p
)))
6845 for (i
= 0; i
< ARRAY_SIZE(p
.resv
); i
++) {
6850 if (p
.flags
& ~(IORING_SETUP_IOPOLL
| IORING_SETUP_SQPOLL
|
6851 IORING_SETUP_SQ_AFF
| IORING_SETUP_CQSIZE
|
6852 IORING_SETUP_CLAMP
| IORING_SETUP_ATTACH_WQ
))
6855 ret
= io_uring_create(entries
, &p
);
6859 if (copy_to_user(params
, &p
, sizeof(p
)))
6865 SYSCALL_DEFINE2(io_uring_setup
, u32
, entries
,
6866 struct io_uring_params __user
*, params
)
6868 return io_uring_setup(entries
, params
);
6871 static int io_probe(struct io_ring_ctx
*ctx
, void __user
*arg
, unsigned nr_args
)
6873 struct io_uring_probe
*p
;
6877 size
= struct_size(p
, ops
, nr_args
);
6878 if (size
== SIZE_MAX
)
6880 p
= kzalloc(size
, GFP_KERNEL
);
6885 if (copy_from_user(p
, arg
, size
))
6888 if (memchr_inv(p
, 0, size
))
6891 p
->last_op
= IORING_OP_LAST
- 1;
6892 if (nr_args
> IORING_OP_LAST
)
6893 nr_args
= IORING_OP_LAST
;
6895 for (i
= 0; i
< nr_args
; i
++) {
6897 if (!io_op_defs
[i
].not_supported
)
6898 p
->ops
[i
].flags
= IO_URING_OP_SUPPORTED
;
6903 if (copy_to_user(arg
, p
, size
))
6910 static int io_register_personality(struct io_ring_ctx
*ctx
)
6912 const struct cred
*creds
= get_current_cred();
6915 id
= idr_alloc_cyclic(&ctx
->personality_idr
, (void *) creds
, 1,
6916 USHRT_MAX
, GFP_KERNEL
);
6922 static int io_unregister_personality(struct io_ring_ctx
*ctx
, unsigned id
)
6924 const struct cred
*old_creds
;
6926 old_creds
= idr_remove(&ctx
->personality_idr
, id
);
6928 put_cred(old_creds
);
6935 static bool io_register_op_must_quiesce(int op
)
6938 case IORING_UNREGISTER_FILES
:
6939 case IORING_REGISTER_FILES_UPDATE
:
6940 case IORING_REGISTER_PROBE
:
6941 case IORING_REGISTER_PERSONALITY
:
6942 case IORING_UNREGISTER_PERSONALITY
:
6949 static int __io_uring_register(struct io_ring_ctx
*ctx
, unsigned opcode
,
6950 void __user
*arg
, unsigned nr_args
)
6951 __releases(ctx
->uring_lock
)
6952 __acquires(ctx
->uring_lock
)
6957 * We're inside the ring mutex, if the ref is already dying, then
6958 * someone else killed the ctx or is already going through
6959 * io_uring_register().
6961 if (percpu_ref_is_dying(&ctx
->refs
))
6964 if (io_register_op_must_quiesce(opcode
)) {
6965 percpu_ref_kill(&ctx
->refs
);
6968 * Drop uring mutex before waiting for references to exit. If
6969 * another thread is currently inside io_uring_enter() it might
6970 * need to grab the uring_lock to make progress. If we hold it
6971 * here across the drain wait, then we can deadlock. It's safe
6972 * to drop the mutex here, since no new references will come in
6973 * after we've killed the percpu ref.
6975 mutex_unlock(&ctx
->uring_lock
);
6976 ret
= wait_for_completion_interruptible(&ctx
->completions
[0]);
6977 mutex_lock(&ctx
->uring_lock
);
6979 percpu_ref_resurrect(&ctx
->refs
);
6986 case IORING_REGISTER_BUFFERS
:
6987 ret
= io_sqe_buffer_register(ctx
, arg
, nr_args
);
6989 case IORING_UNREGISTER_BUFFERS
:
6993 ret
= io_sqe_buffer_unregister(ctx
);
6995 case IORING_REGISTER_FILES
:
6996 ret
= io_sqe_files_register(ctx
, arg
, nr_args
);
6998 case IORING_UNREGISTER_FILES
:
7002 ret
= io_sqe_files_unregister(ctx
);
7004 case IORING_REGISTER_FILES_UPDATE
:
7005 ret
= io_sqe_files_update(ctx
, arg
, nr_args
);
7007 case IORING_REGISTER_EVENTFD
:
7008 case IORING_REGISTER_EVENTFD_ASYNC
:
7012 ret
= io_eventfd_register(ctx
, arg
);
7015 if (opcode
== IORING_REGISTER_EVENTFD_ASYNC
)
7016 ctx
->eventfd_async
= 1;
7018 ctx
->eventfd_async
= 0;
7020 case IORING_UNREGISTER_EVENTFD
:
7024 ret
= io_eventfd_unregister(ctx
);
7026 case IORING_REGISTER_PROBE
:
7028 if (!arg
|| nr_args
> 256)
7030 ret
= io_probe(ctx
, arg
, nr_args
);
7032 case IORING_REGISTER_PERSONALITY
:
7036 ret
= io_register_personality(ctx
);
7038 case IORING_UNREGISTER_PERSONALITY
:
7042 ret
= io_unregister_personality(ctx
, nr_args
);
7049 if (io_register_op_must_quiesce(opcode
)) {
7050 /* bring the ctx back to life */
7051 percpu_ref_reinit(&ctx
->refs
);
7053 reinit_completion(&ctx
->completions
[0]);
7058 SYSCALL_DEFINE4(io_uring_register
, unsigned int, fd
, unsigned int, opcode
,
7059 void __user
*, arg
, unsigned int, nr_args
)
7061 struct io_ring_ctx
*ctx
;
7070 if (f
.file
->f_op
!= &io_uring_fops
)
7073 ctx
= f
.file
->private_data
;
7075 mutex_lock(&ctx
->uring_lock
);
7076 ret
= __io_uring_register(ctx
, opcode
, arg
, nr_args
);
7077 mutex_unlock(&ctx
->uring_lock
);
7078 trace_io_uring_register(ctx
, opcode
, ctx
->nr_user_files
, ctx
->nr_user_bufs
,
7079 ctx
->cq_ev_fd
!= NULL
, ret
);
7085 static int __init
io_uring_init(void)
7087 #define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
7088 BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
7089 BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
7092 #define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
7093 __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
7094 BUILD_BUG_ON(sizeof(struct io_uring_sqe
) != 64);
7095 BUILD_BUG_SQE_ELEM(0, __u8
, opcode
);
7096 BUILD_BUG_SQE_ELEM(1, __u8
, flags
);
7097 BUILD_BUG_SQE_ELEM(2, __u16
, ioprio
);
7098 BUILD_BUG_SQE_ELEM(4, __s32
, fd
);
7099 BUILD_BUG_SQE_ELEM(8, __u64
, off
);
7100 BUILD_BUG_SQE_ELEM(8, __u64
, addr2
);
7101 BUILD_BUG_SQE_ELEM(16, __u64
, addr
);
7102 BUILD_BUG_SQE_ELEM(24, __u32
, len
);
7103 BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t
, rw_flags
);
7104 BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags
);
7105 BUILD_BUG_SQE_ELEM(28, /* compat */ __u32
, rw_flags
);
7106 BUILD_BUG_SQE_ELEM(28, __u32
, fsync_flags
);
7107 BUILD_BUG_SQE_ELEM(28, __u16
, poll_events
);
7108 BUILD_BUG_SQE_ELEM(28, __u32
, sync_range_flags
);
7109 BUILD_BUG_SQE_ELEM(28, __u32
, msg_flags
);
7110 BUILD_BUG_SQE_ELEM(28, __u32
, timeout_flags
);
7111 BUILD_BUG_SQE_ELEM(28, __u32
, accept_flags
);
7112 BUILD_BUG_SQE_ELEM(28, __u32
, cancel_flags
);
7113 BUILD_BUG_SQE_ELEM(28, __u32
, open_flags
);
7114 BUILD_BUG_SQE_ELEM(28, __u32
, statx_flags
);
7115 BUILD_BUG_SQE_ELEM(28, __u32
, fadvise_advice
);
7116 BUILD_BUG_SQE_ELEM(32, __u64
, user_data
);
7117 BUILD_BUG_SQE_ELEM(40, __u16
, buf_index
);
7118 BUILD_BUG_SQE_ELEM(42, __u16
, personality
);
7120 BUILD_BUG_ON(ARRAY_SIZE(io_op_defs
) != IORING_OP_LAST
);
7121 req_cachep
= KMEM_CACHE(io_kiocb
, SLAB_HWCACHE_ALIGN
| SLAB_PANIC
);
7124 __initcall(io_uring_init
);