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2b188cc1 JA |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * Shared application/kernel submission and completion ring pairs, for | |
4 | * supporting fast/efficient IO. | |
5 | * | |
6 | * A note on the read/write ordering memory barriers that are matched between | |
1e84b97b SB |
7 | * the application and kernel side. |
8 | * | |
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 | |
16 | * CQ entries. | |
17 | * | |
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 | |
23 | * head will do). | |
24 | * | |
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 | |
28 | * between. | |
2b188cc1 JA |
29 | * |
30 | * Also see the examples in the liburing library: | |
31 | * | |
32 | * git://git.kernel.dk/liburing | |
33 | * | |
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. | |
38 | * | |
39 | * Copyright (C) 2018-2019 Jens Axboe | |
c992fe29 | 40 | * Copyright (c) 2018-2019 Christoph Hellwig |
2b188cc1 JA |
41 | */ |
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 | ||
50 | #include <linux/sched/signal.h> | |
51 | #include <linux/fs.h> | |
52 | #include <linux/file.h> | |
53 | #include <linux/fdtable.h> | |
54 | #include <linux/mm.h> | |
55 | #include <linux/mman.h> | |
56 | #include <linux/mmu_context.h> | |
57 | #include <linux/percpu.h> | |
58 | #include <linux/slab.h> | |
6c271ce2 | 59 | #include <linux/kthread.h> |
2b188cc1 | 60 | #include <linux/blkdev.h> |
edafccee | 61 | #include <linux/bvec.h> |
2b188cc1 JA |
62 | #include <linux/net.h> |
63 | #include <net/sock.h> | |
64 | #include <net/af_unix.h> | |
6b06314c | 65 | #include <net/scm.h> |
2b188cc1 JA |
66 | #include <linux/anon_inodes.h> |
67 | #include <linux/sched/mm.h> | |
68 | #include <linux/uaccess.h> | |
69 | #include <linux/nospec.h> | |
edafccee JA |
70 | #include <linux/sizes.h> |
71 | #include <linux/hugetlb.h> | |
aa4c3967 | 72 | #include <linux/highmem.h> |
2b188cc1 | 73 | |
c826bd7a DD |
74 | #define CREATE_TRACE_POINTS |
75 | #include <trace/events/io_uring.h> | |
76 | ||
2b188cc1 JA |
77 | #include <uapi/linux/io_uring.h> |
78 | ||
79 | #include "internal.h" | |
561fb04a | 80 | #include "io-wq.h" |
2b188cc1 | 81 | |
5277deaa | 82 | #define IORING_MAX_ENTRIES 32768 |
33a107f0 | 83 | #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) |
65e19f54 JA |
84 | |
85 | /* | |
86 | * Shift of 9 is 512 entries, or exactly one page on 64-bit archs | |
87 | */ | |
88 | #define IORING_FILE_TABLE_SHIFT 9 | |
89 | #define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT) | |
90 | #define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1) | |
91 | #define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE) | |
2b188cc1 JA |
92 | |
93 | struct io_uring { | |
94 | u32 head ____cacheline_aligned_in_smp; | |
95 | u32 tail ____cacheline_aligned_in_smp; | |
96 | }; | |
97 | ||
1e84b97b | 98 | /* |
75b28aff HV |
99 | * This data is shared with the application through the mmap at offsets |
100 | * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING. | |
1e84b97b SB |
101 | * |
102 | * The offsets to the member fields are published through struct | |
103 | * io_sqring_offsets when calling io_uring_setup. | |
104 | */ | |
75b28aff | 105 | struct io_rings { |
1e84b97b SB |
106 | /* |
107 | * Head and tail offsets into the ring; the offsets need to be | |
108 | * masked to get valid indices. | |
109 | * | |
75b28aff HV |
110 | * The kernel controls head of the sq ring and the tail of the cq ring, |
111 | * and the application controls tail of the sq ring and the head of the | |
112 | * cq ring. | |
1e84b97b | 113 | */ |
75b28aff | 114 | struct io_uring sq, cq; |
1e84b97b | 115 | /* |
75b28aff | 116 | * Bitmasks to apply to head and tail offsets (constant, equals |
1e84b97b SB |
117 | * ring_entries - 1) |
118 | */ | |
75b28aff HV |
119 | u32 sq_ring_mask, cq_ring_mask; |
120 | /* Ring sizes (constant, power of 2) */ | |
121 | u32 sq_ring_entries, cq_ring_entries; | |
1e84b97b SB |
122 | /* |
123 | * Number of invalid entries dropped by the kernel due to | |
124 | * invalid index stored in array | |
125 | * | |
126 | * Written by the kernel, shouldn't be modified by the | |
127 | * application (i.e. get number of "new events" by comparing to | |
128 | * cached value). | |
129 | * | |
130 | * After a new SQ head value was read by the application this | |
131 | * counter includes all submissions that were dropped reaching | |
132 | * the new SQ head (and possibly more). | |
133 | */ | |
75b28aff | 134 | u32 sq_dropped; |
1e84b97b SB |
135 | /* |
136 | * Runtime flags | |
137 | * | |
138 | * Written by the kernel, shouldn't be modified by the | |
139 | * application. | |
140 | * | |
141 | * The application needs a full memory barrier before checking | |
142 | * for IORING_SQ_NEED_WAKEUP after updating the sq tail. | |
143 | */ | |
75b28aff | 144 | u32 sq_flags; |
1e84b97b SB |
145 | /* |
146 | * Number of completion events lost because the queue was full; | |
147 | * this should be avoided by the application by making sure | |
0b4295b5 | 148 | * there are not more requests pending than there is space in |
1e84b97b SB |
149 | * the completion queue. |
150 | * | |
151 | * Written by the kernel, shouldn't be modified by the | |
152 | * application (i.e. get number of "new events" by comparing to | |
153 | * cached value). | |
154 | * | |
155 | * As completion events come in out of order this counter is not | |
156 | * ordered with any other data. | |
157 | */ | |
75b28aff | 158 | u32 cq_overflow; |
1e84b97b SB |
159 | /* |
160 | * Ring buffer of completion events. | |
161 | * | |
162 | * The kernel writes completion events fresh every time they are | |
163 | * produced, so the application is allowed to modify pending | |
164 | * entries. | |
165 | */ | |
75b28aff | 166 | struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp; |
2b188cc1 JA |
167 | }; |
168 | ||
edafccee JA |
169 | struct io_mapped_ubuf { |
170 | u64 ubuf; | |
171 | size_t len; | |
172 | struct bio_vec *bvec; | |
173 | unsigned int nr_bvecs; | |
174 | }; | |
175 | ||
65e19f54 JA |
176 | struct fixed_file_table { |
177 | struct file **files; | |
31b51510 JA |
178 | }; |
179 | ||
2b188cc1 JA |
180 | struct io_ring_ctx { |
181 | struct { | |
182 | struct percpu_ref refs; | |
183 | } ____cacheline_aligned_in_smp; | |
184 | ||
185 | struct { | |
186 | unsigned int flags; | |
187 | bool compat; | |
188 | bool account_mem; | |
1d7bb1d5 | 189 | bool cq_overflow_flushed; |
1b4a51b6 | 190 | bool drain_next; |
2b188cc1 | 191 | |
75b28aff HV |
192 | /* |
193 | * Ring buffer of indices into array of io_uring_sqe, which is | |
194 | * mmapped by the application using the IORING_OFF_SQES offset. | |
195 | * | |
196 | * This indirection could e.g. be used to assign fixed | |
197 | * io_uring_sqe entries to operations and only submit them to | |
198 | * the queue when needed. | |
199 | * | |
200 | * The kernel modifies neither the indices array nor the entries | |
201 | * array. | |
202 | */ | |
203 | u32 *sq_array; | |
2b188cc1 JA |
204 | unsigned cached_sq_head; |
205 | unsigned sq_entries; | |
206 | unsigned sq_mask; | |
6c271ce2 | 207 | unsigned sq_thread_idle; |
498ccd9e | 208 | unsigned cached_sq_dropped; |
206aefde | 209 | atomic_t cached_cq_overflow; |
2b188cc1 | 210 | struct io_uring_sqe *sq_sqes; |
de0617e4 JA |
211 | |
212 | struct list_head defer_list; | |
5262f567 | 213 | struct list_head timeout_list; |
1d7bb1d5 | 214 | struct list_head cq_overflow_list; |
fcb323cc JA |
215 | |
216 | wait_queue_head_t inflight_wait; | |
2b188cc1 JA |
217 | } ____cacheline_aligned_in_smp; |
218 | ||
206aefde JA |
219 | struct io_rings *rings; |
220 | ||
2b188cc1 | 221 | /* IO offload */ |
561fb04a | 222 | struct io_wq *io_wq; |
6c271ce2 | 223 | struct task_struct *sqo_thread; /* if using sq thread polling */ |
2b188cc1 | 224 | struct mm_struct *sqo_mm; |
6c271ce2 | 225 | wait_queue_head_t sqo_wait; |
75b28aff | 226 | |
6b06314c JA |
227 | /* |
228 | * If used, fixed file set. Writers must ensure that ->refs is dead, | |
229 | * readers must ensure that ->refs is alive as long as the file* is | |
230 | * used. Only updated through io_uring_register(2). | |
231 | */ | |
65e19f54 | 232 | struct fixed_file_table *file_table; |
6b06314c JA |
233 | unsigned nr_user_files; |
234 | ||
edafccee JA |
235 | /* if used, fixed mapped user buffers */ |
236 | unsigned nr_user_bufs; | |
237 | struct io_mapped_ubuf *user_bufs; | |
238 | ||
2b188cc1 JA |
239 | struct user_struct *user; |
240 | ||
0b8c0ec7 | 241 | const struct cred *creds; |
181e448d | 242 | |
206aefde JA |
243 | /* 0 is for ctx quiesce/reinit/free, 1 is for sqo_thread started */ |
244 | struct completion *completions; | |
245 | ||
0ddf92e8 JA |
246 | /* if all else fails... */ |
247 | struct io_kiocb *fallback_req; | |
248 | ||
206aefde JA |
249 | #if defined(CONFIG_UNIX) |
250 | struct socket *ring_sock; | |
251 | #endif | |
252 | ||
253 | struct { | |
254 | unsigned cached_cq_tail; | |
255 | unsigned cq_entries; | |
256 | unsigned cq_mask; | |
257 | atomic_t cq_timeouts; | |
258 | struct wait_queue_head cq_wait; | |
259 | struct fasync_struct *cq_fasync; | |
260 | struct eventfd_ctx *cq_ev_fd; | |
261 | } ____cacheline_aligned_in_smp; | |
2b188cc1 JA |
262 | |
263 | struct { | |
264 | struct mutex uring_lock; | |
265 | wait_queue_head_t wait; | |
266 | } ____cacheline_aligned_in_smp; | |
267 | ||
268 | struct { | |
269 | spinlock_t completion_lock; | |
def596e9 JA |
270 | bool poll_multi_file; |
271 | /* | |
272 | * ->poll_list is protected by the ctx->uring_lock for | |
273 | * io_uring instances that don't use IORING_SETUP_SQPOLL. | |
274 | * For SQPOLL, only the single threaded io_sq_thread() will | |
275 | * manipulate the list, hence no extra locking is needed there. | |
276 | */ | |
277 | struct list_head poll_list; | |
78076bb6 JA |
278 | struct hlist_head *cancel_hash; |
279 | unsigned cancel_hash_bits; | |
31b51510 | 280 | |
fcb323cc JA |
281 | spinlock_t inflight_lock; |
282 | struct list_head inflight_list; | |
2b188cc1 | 283 | } ____cacheline_aligned_in_smp; |
2b188cc1 JA |
284 | }; |
285 | ||
09bb8394 JA |
286 | /* |
287 | * First field must be the file pointer in all the | |
288 | * iocb unions! See also 'struct kiocb' in <linux/fs.h> | |
289 | */ | |
221c5eb2 JA |
290 | struct io_poll_iocb { |
291 | struct file *file; | |
0969e783 JA |
292 | union { |
293 | struct wait_queue_head *head; | |
294 | u64 addr; | |
295 | }; | |
221c5eb2 | 296 | __poll_t events; |
8c838788 | 297 | bool done; |
221c5eb2 | 298 | bool canceled; |
392edb45 | 299 | struct wait_queue_entry wait; |
221c5eb2 JA |
300 | }; |
301 | ||
ad8a48ac JA |
302 | struct io_timeout_data { |
303 | struct io_kiocb *req; | |
304 | struct hrtimer timer; | |
305 | struct timespec64 ts; | |
306 | enum hrtimer_mode mode; | |
cc42e0ac | 307 | u32 seq_offset; |
ad8a48ac JA |
308 | }; |
309 | ||
8ed8d3c3 JA |
310 | struct io_accept { |
311 | struct file *file; | |
312 | struct sockaddr __user *addr; | |
313 | int __user *addr_len; | |
314 | int flags; | |
315 | }; | |
316 | ||
317 | struct io_sync { | |
318 | struct file *file; | |
319 | loff_t len; | |
320 | loff_t off; | |
321 | int flags; | |
322 | }; | |
323 | ||
fbf23849 JA |
324 | struct io_cancel { |
325 | struct file *file; | |
326 | u64 addr; | |
327 | }; | |
328 | ||
b29472ee JA |
329 | struct io_timeout { |
330 | struct file *file; | |
331 | u64 addr; | |
332 | int flags; | |
26a61679 | 333 | unsigned count; |
b29472ee JA |
334 | }; |
335 | ||
9adbd45d JA |
336 | struct io_rw { |
337 | /* NOTE: kiocb has the file as the first member, so don't do it here */ | |
338 | struct kiocb kiocb; | |
339 | u64 addr; | |
340 | u64 len; | |
341 | }; | |
342 | ||
3fbb51c1 JA |
343 | struct io_connect { |
344 | struct file *file; | |
345 | struct sockaddr __user *addr; | |
346 | int addr_len; | |
347 | }; | |
348 | ||
e47293fd JA |
349 | struct io_sr_msg { |
350 | struct file *file; | |
351 | struct user_msghdr __user *msg; | |
352 | int msg_flags; | |
353 | }; | |
354 | ||
f499a021 JA |
355 | struct io_async_connect { |
356 | struct sockaddr_storage address; | |
357 | }; | |
358 | ||
03b1230c JA |
359 | struct io_async_msghdr { |
360 | struct iovec fast_iov[UIO_FASTIOV]; | |
361 | struct iovec *iov; | |
362 | struct sockaddr __user *uaddr; | |
363 | struct msghdr msg; | |
364 | }; | |
365 | ||
f67676d1 JA |
366 | struct io_async_rw { |
367 | struct iovec fast_iov[UIO_FASTIOV]; | |
368 | struct iovec *iov; | |
369 | ssize_t nr_segs; | |
370 | ssize_t size; | |
371 | }; | |
372 | ||
1a6b74fc | 373 | struct io_async_ctx { |
f67676d1 JA |
374 | union { |
375 | struct io_async_rw rw; | |
03b1230c | 376 | struct io_async_msghdr msg; |
f499a021 | 377 | struct io_async_connect connect; |
2d28390a | 378 | struct io_timeout_data timeout; |
f67676d1 | 379 | }; |
1a6b74fc JA |
380 | }; |
381 | ||
09bb8394 JA |
382 | /* |
383 | * NOTE! Each of the iocb union members has the file pointer | |
384 | * as the first entry in their struct definition. So you can | |
385 | * access the file pointer through any of the sub-structs, | |
386 | * or directly as just 'ki_filp' in this struct. | |
387 | */ | |
2b188cc1 | 388 | struct io_kiocb { |
221c5eb2 | 389 | union { |
09bb8394 | 390 | struct file *file; |
9adbd45d | 391 | struct io_rw rw; |
221c5eb2 | 392 | struct io_poll_iocb poll; |
8ed8d3c3 JA |
393 | struct io_accept accept; |
394 | struct io_sync sync; | |
fbf23849 | 395 | struct io_cancel cancel; |
b29472ee | 396 | struct io_timeout timeout; |
3fbb51c1 | 397 | struct io_connect connect; |
e47293fd | 398 | struct io_sr_msg sr_msg; |
221c5eb2 | 399 | }; |
2b188cc1 | 400 | |
1a6b74fc | 401 | struct io_async_ctx *io; |
cf6fd4bd PB |
402 | struct file *ring_file; |
403 | int ring_fd; | |
404 | bool has_user; | |
405 | bool in_async; | |
406 | bool needs_fixed_file; | |
d625c6ee | 407 | u8 opcode; |
2b188cc1 JA |
408 | |
409 | struct io_ring_ctx *ctx; | |
eac406c6 JA |
410 | union { |
411 | struct list_head list; | |
78076bb6 | 412 | struct hlist_node hash_node; |
eac406c6 | 413 | }; |
9e645e11 | 414 | struct list_head link_list; |
2b188cc1 | 415 | unsigned int flags; |
c16361c1 | 416 | refcount_t refs; |
8449eeda | 417 | #define REQ_F_NOWAIT 1 /* must not punt to workers */ |
def596e9 | 418 | #define REQ_F_IOPOLL_COMPLETED 2 /* polled IO has completed */ |
6b06314c | 419 | #define REQ_F_FIXED_FILE 4 /* ctx owns file */ |
4d7dd462 | 420 | #define REQ_F_LINK_NEXT 8 /* already grabbed next link */ |
e2033e33 SB |
421 | #define REQ_F_IO_DRAIN 16 /* drain existing IO first */ |
422 | #define REQ_F_IO_DRAINED 32 /* drain done */ | |
9e645e11 | 423 | #define REQ_F_LINK 64 /* linked sqes */ |
2665abfd | 424 | #define REQ_F_LINK_TIMEOUT 128 /* has linked timeout */ |
f7b76ac9 | 425 | #define REQ_F_FAIL_LINK 256 /* fail rest of links */ |
1b4a51b6 | 426 | #define REQ_F_DRAIN_LINK 512 /* link should be fully drained */ |
5262f567 | 427 | #define REQ_F_TIMEOUT 1024 /* timeout request */ |
491381ce JA |
428 | #define REQ_F_ISREG 2048 /* regular file */ |
429 | #define REQ_F_MUST_PUNT 4096 /* must be punted even for NONBLOCK */ | |
93bd25bb | 430 | #define REQ_F_TIMEOUT_NOSEQ 8192 /* no timeout sequence */ |
fb4b3d3f LT |
431 | #define REQ_F_INFLIGHT 16384 /* on inflight list */ |
432 | #define REQ_F_COMP_LOCKED 32768 /* completion under lock */ | |
4e88d6e7 | 433 | #define REQ_F_HARDLINK 65536 /* doesn't sever on completion < 0 */ |
2b188cc1 | 434 | u64 user_data; |
9e645e11 | 435 | u32 result; |
de0617e4 | 436 | u32 sequence; |
2b188cc1 | 437 | |
fcb323cc JA |
438 | struct list_head inflight_entry; |
439 | ||
561fb04a | 440 | struct io_wq_work work; |
2b188cc1 JA |
441 | }; |
442 | ||
443 | #define IO_PLUG_THRESHOLD 2 | |
def596e9 | 444 | #define IO_IOPOLL_BATCH 8 |
2b188cc1 | 445 | |
9a56a232 JA |
446 | struct io_submit_state { |
447 | struct blk_plug plug; | |
448 | ||
2579f913 JA |
449 | /* |
450 | * io_kiocb alloc cache | |
451 | */ | |
452 | void *reqs[IO_IOPOLL_BATCH]; | |
453 | unsigned int free_reqs; | |
454 | unsigned int cur_req; | |
455 | ||
9a56a232 JA |
456 | /* |
457 | * File reference cache | |
458 | */ | |
459 | struct file *file; | |
460 | unsigned int fd; | |
461 | unsigned int has_refs; | |
462 | unsigned int used_refs; | |
463 | unsigned int ios_left; | |
464 | }; | |
465 | ||
561fb04a | 466 | static void io_wq_submit_work(struct io_wq_work **workptr); |
78e19bbe | 467 | static void io_cqring_fill_event(struct io_kiocb *req, long res); |
4fe2c963 | 468 | static void __io_free_req(struct io_kiocb *req); |
ec9c02ad | 469 | static void io_put_req(struct io_kiocb *req); |
78e19bbe | 470 | static void io_double_put_req(struct io_kiocb *req); |
978db57e | 471 | static void __io_double_put_req(struct io_kiocb *req); |
94ae5e77 JA |
472 | static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req); |
473 | static void io_queue_linked_timeout(struct io_kiocb *req); | |
de0617e4 | 474 | |
2b188cc1 JA |
475 | static struct kmem_cache *req_cachep; |
476 | ||
477 | static const struct file_operations io_uring_fops; | |
478 | ||
479 | struct sock *io_uring_get_socket(struct file *file) | |
480 | { | |
481 | #if defined(CONFIG_UNIX) | |
482 | if (file->f_op == &io_uring_fops) { | |
483 | struct io_ring_ctx *ctx = file->private_data; | |
484 | ||
485 | return ctx->ring_sock->sk; | |
486 | } | |
487 | #endif | |
488 | return NULL; | |
489 | } | |
490 | EXPORT_SYMBOL(io_uring_get_socket); | |
491 | ||
492 | static void io_ring_ctx_ref_free(struct percpu_ref *ref) | |
493 | { | |
494 | struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); | |
495 | ||
206aefde | 496 | complete(&ctx->completions[0]); |
2b188cc1 JA |
497 | } |
498 | ||
499 | static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) | |
500 | { | |
501 | struct io_ring_ctx *ctx; | |
78076bb6 | 502 | int hash_bits; |
2b188cc1 JA |
503 | |
504 | ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); | |
505 | if (!ctx) | |
506 | return NULL; | |
507 | ||
0ddf92e8 JA |
508 | ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL); |
509 | if (!ctx->fallback_req) | |
510 | goto err; | |
511 | ||
206aefde JA |
512 | ctx->completions = kmalloc(2 * sizeof(struct completion), GFP_KERNEL); |
513 | if (!ctx->completions) | |
514 | goto err; | |
515 | ||
78076bb6 JA |
516 | /* |
517 | * Use 5 bits less than the max cq entries, that should give us around | |
518 | * 32 entries per hash list if totally full and uniformly spread. | |
519 | */ | |
520 | hash_bits = ilog2(p->cq_entries); | |
521 | hash_bits -= 5; | |
522 | if (hash_bits <= 0) | |
523 | hash_bits = 1; | |
524 | ctx->cancel_hash_bits = hash_bits; | |
525 | ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head), | |
526 | GFP_KERNEL); | |
527 | if (!ctx->cancel_hash) | |
528 | goto err; | |
529 | __hash_init(ctx->cancel_hash, 1U << hash_bits); | |
530 | ||
21482896 | 531 | if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, |
206aefde JA |
532 | PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) |
533 | goto err; | |
2b188cc1 JA |
534 | |
535 | ctx->flags = p->flags; | |
536 | init_waitqueue_head(&ctx->cq_wait); | |
1d7bb1d5 | 537 | INIT_LIST_HEAD(&ctx->cq_overflow_list); |
206aefde JA |
538 | init_completion(&ctx->completions[0]); |
539 | init_completion(&ctx->completions[1]); | |
2b188cc1 JA |
540 | mutex_init(&ctx->uring_lock); |
541 | init_waitqueue_head(&ctx->wait); | |
542 | spin_lock_init(&ctx->completion_lock); | |
def596e9 | 543 | INIT_LIST_HEAD(&ctx->poll_list); |
de0617e4 | 544 | INIT_LIST_HEAD(&ctx->defer_list); |
5262f567 | 545 | INIT_LIST_HEAD(&ctx->timeout_list); |
fcb323cc JA |
546 | init_waitqueue_head(&ctx->inflight_wait); |
547 | spin_lock_init(&ctx->inflight_lock); | |
548 | INIT_LIST_HEAD(&ctx->inflight_list); | |
2b188cc1 | 549 | return ctx; |
206aefde | 550 | err: |
0ddf92e8 JA |
551 | if (ctx->fallback_req) |
552 | kmem_cache_free(req_cachep, ctx->fallback_req); | |
206aefde | 553 | kfree(ctx->completions); |
78076bb6 | 554 | kfree(ctx->cancel_hash); |
206aefde JA |
555 | kfree(ctx); |
556 | return NULL; | |
2b188cc1 JA |
557 | } |
558 | ||
9d858b21 | 559 | static inline bool __req_need_defer(struct io_kiocb *req) |
7adf4eaf | 560 | { |
a197f664 JL |
561 | struct io_ring_ctx *ctx = req->ctx; |
562 | ||
498ccd9e JA |
563 | return req->sequence != ctx->cached_cq_tail + ctx->cached_sq_dropped |
564 | + atomic_read(&ctx->cached_cq_overflow); | |
7adf4eaf JA |
565 | } |
566 | ||
9d858b21 | 567 | static inline bool req_need_defer(struct io_kiocb *req) |
de0617e4 | 568 | { |
9d858b21 BL |
569 | if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) == REQ_F_IO_DRAIN) |
570 | return __req_need_defer(req); | |
de0617e4 | 571 | |
9d858b21 | 572 | return false; |
de0617e4 JA |
573 | } |
574 | ||
7adf4eaf | 575 | static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx) |
de0617e4 JA |
576 | { |
577 | struct io_kiocb *req; | |
578 | ||
7adf4eaf | 579 | req = list_first_entry_or_null(&ctx->defer_list, struct io_kiocb, list); |
9d858b21 | 580 | if (req && !req_need_defer(req)) { |
de0617e4 JA |
581 | list_del_init(&req->list); |
582 | return req; | |
583 | } | |
584 | ||
585 | return NULL; | |
586 | } | |
587 | ||
5262f567 JA |
588 | static struct io_kiocb *io_get_timeout_req(struct io_ring_ctx *ctx) |
589 | { | |
7adf4eaf JA |
590 | struct io_kiocb *req; |
591 | ||
592 | req = list_first_entry_or_null(&ctx->timeout_list, struct io_kiocb, list); | |
93bd25bb JA |
593 | if (req) { |
594 | if (req->flags & REQ_F_TIMEOUT_NOSEQ) | |
595 | return NULL; | |
fb4b3d3f | 596 | if (!__req_need_defer(req)) { |
93bd25bb JA |
597 | list_del_init(&req->list); |
598 | return req; | |
599 | } | |
7adf4eaf JA |
600 | } |
601 | ||
602 | return NULL; | |
5262f567 JA |
603 | } |
604 | ||
de0617e4 | 605 | static void __io_commit_cqring(struct io_ring_ctx *ctx) |
2b188cc1 | 606 | { |
75b28aff | 607 | struct io_rings *rings = ctx->rings; |
2b188cc1 | 608 | |
75b28aff | 609 | if (ctx->cached_cq_tail != READ_ONCE(rings->cq.tail)) { |
2b188cc1 | 610 | /* order cqe stores with ring update */ |
75b28aff | 611 | smp_store_release(&rings->cq.tail, ctx->cached_cq_tail); |
2b188cc1 | 612 | |
2b188cc1 JA |
613 | if (wq_has_sleeper(&ctx->cq_wait)) { |
614 | wake_up_interruptible(&ctx->cq_wait); | |
615 | kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); | |
616 | } | |
617 | } | |
618 | } | |
619 | ||
d625c6ee | 620 | static inline bool io_req_needs_user(struct io_kiocb *req) |
18d9be1a | 621 | { |
d625c6ee JA |
622 | return !(req->opcode == IORING_OP_READ_FIXED || |
623 | req->opcode == IORING_OP_WRITE_FIXED); | |
561fb04a JA |
624 | } |
625 | ||
94ae5e77 JA |
626 | static inline bool io_prep_async_work(struct io_kiocb *req, |
627 | struct io_kiocb **link) | |
18d9be1a | 628 | { |
561fb04a | 629 | bool do_hashed = false; |
54a91f3b | 630 | |
3529d8c2 JA |
631 | switch (req->opcode) { |
632 | case IORING_OP_WRITEV: | |
633 | case IORING_OP_WRITE_FIXED: | |
634 | /* only regular files should be hashed for writes */ | |
635 | if (req->flags & REQ_F_ISREG) | |
636 | do_hashed = true; | |
637 | /* fall-through */ | |
638 | case IORING_OP_READV: | |
639 | case IORING_OP_READ_FIXED: | |
640 | case IORING_OP_SENDMSG: | |
641 | case IORING_OP_RECVMSG: | |
642 | case IORING_OP_ACCEPT: | |
643 | case IORING_OP_POLL_ADD: | |
644 | case IORING_OP_CONNECT: | |
645 | /* | |
646 | * We know REQ_F_ISREG is not set on some of these | |
647 | * opcodes, but this enables us to keep the check in | |
648 | * just one place. | |
649 | */ | |
650 | if (!(req->flags & REQ_F_ISREG)) | |
651 | req->work.flags |= IO_WQ_WORK_UNBOUND; | |
652 | break; | |
54a91f3b | 653 | } |
3529d8c2 JA |
654 | if (io_req_needs_user(req)) |
655 | req->work.flags |= IO_WQ_WORK_NEEDS_USER; | |
54a91f3b | 656 | |
94ae5e77 | 657 | *link = io_prep_linked_timeout(req); |
561fb04a JA |
658 | return do_hashed; |
659 | } | |
660 | ||
a197f664 | 661 | static inline void io_queue_async_work(struct io_kiocb *req) |
561fb04a | 662 | { |
a197f664 | 663 | struct io_ring_ctx *ctx = req->ctx; |
94ae5e77 JA |
664 | struct io_kiocb *link; |
665 | bool do_hashed; | |
666 | ||
667 | do_hashed = io_prep_async_work(req, &link); | |
561fb04a JA |
668 | |
669 | trace_io_uring_queue_async_work(ctx, do_hashed, req, &req->work, | |
670 | req->flags); | |
671 | if (!do_hashed) { | |
672 | io_wq_enqueue(ctx->io_wq, &req->work); | |
673 | } else { | |
674 | io_wq_enqueue_hashed(ctx->io_wq, &req->work, | |
675 | file_inode(req->file)); | |
676 | } | |
94ae5e77 JA |
677 | |
678 | if (link) | |
679 | io_queue_linked_timeout(link); | |
18d9be1a JA |
680 | } |
681 | ||
5262f567 JA |
682 | static void io_kill_timeout(struct io_kiocb *req) |
683 | { | |
684 | int ret; | |
685 | ||
2d28390a | 686 | ret = hrtimer_try_to_cancel(&req->io->timeout.timer); |
5262f567 JA |
687 | if (ret != -1) { |
688 | atomic_inc(&req->ctx->cq_timeouts); | |
842f9612 | 689 | list_del_init(&req->list); |
78e19bbe | 690 | io_cqring_fill_event(req, 0); |
ec9c02ad | 691 | io_put_req(req); |
5262f567 JA |
692 | } |
693 | } | |
694 | ||
695 | static void io_kill_timeouts(struct io_ring_ctx *ctx) | |
696 | { | |
697 | struct io_kiocb *req, *tmp; | |
698 | ||
699 | spin_lock_irq(&ctx->completion_lock); | |
700 | list_for_each_entry_safe(req, tmp, &ctx->timeout_list, list) | |
701 | io_kill_timeout(req); | |
702 | spin_unlock_irq(&ctx->completion_lock); | |
703 | } | |
704 | ||
de0617e4 JA |
705 | static void io_commit_cqring(struct io_ring_ctx *ctx) |
706 | { | |
707 | struct io_kiocb *req; | |
708 | ||
5262f567 JA |
709 | while ((req = io_get_timeout_req(ctx)) != NULL) |
710 | io_kill_timeout(req); | |
711 | ||
de0617e4 JA |
712 | __io_commit_cqring(ctx); |
713 | ||
714 | while ((req = io_get_deferred_req(ctx)) != NULL) { | |
715 | req->flags |= REQ_F_IO_DRAINED; | |
a197f664 | 716 | io_queue_async_work(req); |
de0617e4 JA |
717 | } |
718 | } | |
719 | ||
2b188cc1 JA |
720 | static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) |
721 | { | |
75b28aff | 722 | struct io_rings *rings = ctx->rings; |
2b188cc1 JA |
723 | unsigned tail; |
724 | ||
725 | tail = ctx->cached_cq_tail; | |
115e12e5 SB |
726 | /* |
727 | * writes to the cq entry need to come after reading head; the | |
728 | * control dependency is enough as we're using WRITE_ONCE to | |
729 | * fill the cq entry | |
730 | */ | |
75b28aff | 731 | if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries) |
2b188cc1 JA |
732 | return NULL; |
733 | ||
734 | ctx->cached_cq_tail++; | |
75b28aff | 735 | return &rings->cqes[tail & ctx->cq_mask]; |
2b188cc1 JA |
736 | } |
737 | ||
1d7bb1d5 JA |
738 | static void io_cqring_ev_posted(struct io_ring_ctx *ctx) |
739 | { | |
740 | if (waitqueue_active(&ctx->wait)) | |
741 | wake_up(&ctx->wait); | |
742 | if (waitqueue_active(&ctx->sqo_wait)) | |
743 | wake_up(&ctx->sqo_wait); | |
744 | if (ctx->cq_ev_fd) | |
745 | eventfd_signal(ctx->cq_ev_fd, 1); | |
746 | } | |
747 | ||
c4a2ed72 JA |
748 | /* Returns true if there are no backlogged entries after the flush */ |
749 | static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force) | |
1d7bb1d5 JA |
750 | { |
751 | struct io_rings *rings = ctx->rings; | |
752 | struct io_uring_cqe *cqe; | |
753 | struct io_kiocb *req; | |
754 | unsigned long flags; | |
755 | LIST_HEAD(list); | |
756 | ||
757 | if (!force) { | |
758 | if (list_empty_careful(&ctx->cq_overflow_list)) | |
c4a2ed72 | 759 | return true; |
1d7bb1d5 JA |
760 | if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) == |
761 | rings->cq_ring_entries)) | |
c4a2ed72 | 762 | return false; |
1d7bb1d5 JA |
763 | } |
764 | ||
765 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
766 | ||
767 | /* if force is set, the ring is going away. always drop after that */ | |
768 | if (force) | |
769 | ctx->cq_overflow_flushed = true; | |
770 | ||
c4a2ed72 | 771 | cqe = NULL; |
1d7bb1d5 JA |
772 | while (!list_empty(&ctx->cq_overflow_list)) { |
773 | cqe = io_get_cqring(ctx); | |
774 | if (!cqe && !force) | |
775 | break; | |
776 | ||
777 | req = list_first_entry(&ctx->cq_overflow_list, struct io_kiocb, | |
778 | list); | |
779 | list_move(&req->list, &list); | |
780 | if (cqe) { | |
781 | WRITE_ONCE(cqe->user_data, req->user_data); | |
782 | WRITE_ONCE(cqe->res, req->result); | |
783 | WRITE_ONCE(cqe->flags, 0); | |
784 | } else { | |
785 | WRITE_ONCE(ctx->rings->cq_overflow, | |
786 | atomic_inc_return(&ctx->cached_cq_overflow)); | |
787 | } | |
788 | } | |
789 | ||
790 | io_commit_cqring(ctx); | |
791 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
792 | io_cqring_ev_posted(ctx); | |
793 | ||
794 | while (!list_empty(&list)) { | |
795 | req = list_first_entry(&list, struct io_kiocb, list); | |
796 | list_del(&req->list); | |
ec9c02ad | 797 | io_put_req(req); |
1d7bb1d5 | 798 | } |
c4a2ed72 JA |
799 | |
800 | return cqe != NULL; | |
1d7bb1d5 JA |
801 | } |
802 | ||
78e19bbe | 803 | static void io_cqring_fill_event(struct io_kiocb *req, long res) |
2b188cc1 | 804 | { |
78e19bbe | 805 | struct io_ring_ctx *ctx = req->ctx; |
2b188cc1 JA |
806 | struct io_uring_cqe *cqe; |
807 | ||
78e19bbe | 808 | trace_io_uring_complete(ctx, req->user_data, res); |
51c3ff62 | 809 | |
2b188cc1 JA |
810 | /* |
811 | * If we can't get a cq entry, userspace overflowed the | |
812 | * submission (by quite a lot). Increment the overflow count in | |
813 | * the ring. | |
814 | */ | |
815 | cqe = io_get_cqring(ctx); | |
1d7bb1d5 | 816 | if (likely(cqe)) { |
78e19bbe | 817 | WRITE_ONCE(cqe->user_data, req->user_data); |
2b188cc1 | 818 | WRITE_ONCE(cqe->res, res); |
c71ffb67 | 819 | WRITE_ONCE(cqe->flags, 0); |
1d7bb1d5 | 820 | } else if (ctx->cq_overflow_flushed) { |
498ccd9e JA |
821 | WRITE_ONCE(ctx->rings->cq_overflow, |
822 | atomic_inc_return(&ctx->cached_cq_overflow)); | |
1d7bb1d5 JA |
823 | } else { |
824 | refcount_inc(&req->refs); | |
825 | req->result = res; | |
826 | list_add_tail(&req->list, &ctx->cq_overflow_list); | |
2b188cc1 JA |
827 | } |
828 | } | |
829 | ||
78e19bbe | 830 | static void io_cqring_add_event(struct io_kiocb *req, long res) |
2b188cc1 | 831 | { |
78e19bbe | 832 | struct io_ring_ctx *ctx = req->ctx; |
2b188cc1 JA |
833 | unsigned long flags; |
834 | ||
835 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
78e19bbe | 836 | io_cqring_fill_event(req, res); |
2b188cc1 JA |
837 | io_commit_cqring(ctx); |
838 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
839 | ||
8c838788 | 840 | io_cqring_ev_posted(ctx); |
2b188cc1 JA |
841 | } |
842 | ||
0ddf92e8 JA |
843 | static inline bool io_is_fallback_req(struct io_kiocb *req) |
844 | { | |
845 | return req == (struct io_kiocb *) | |
846 | ((unsigned long) req->ctx->fallback_req & ~1UL); | |
847 | } | |
848 | ||
849 | static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx) | |
850 | { | |
851 | struct io_kiocb *req; | |
852 | ||
853 | req = ctx->fallback_req; | |
854 | if (!test_and_set_bit_lock(0, (unsigned long *) ctx->fallback_req)) | |
855 | return req; | |
856 | ||
857 | return NULL; | |
858 | } | |
859 | ||
2579f913 JA |
860 | static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, |
861 | struct io_submit_state *state) | |
2b188cc1 | 862 | { |
fd6fab2c | 863 | gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; |
2b188cc1 JA |
864 | struct io_kiocb *req; |
865 | ||
866 | if (!percpu_ref_tryget(&ctx->refs)) | |
867 | return NULL; | |
868 | ||
2579f913 | 869 | if (!state) { |
fd6fab2c | 870 | req = kmem_cache_alloc(req_cachep, gfp); |
2579f913 | 871 | if (unlikely(!req)) |
0ddf92e8 | 872 | goto fallback; |
2579f913 JA |
873 | } else if (!state->free_reqs) { |
874 | size_t sz; | |
875 | int ret; | |
876 | ||
877 | sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs)); | |
fd6fab2c JA |
878 | ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs); |
879 | ||
880 | /* | |
881 | * Bulk alloc is all-or-nothing. If we fail to get a batch, | |
882 | * retry single alloc to be on the safe side. | |
883 | */ | |
884 | if (unlikely(ret <= 0)) { | |
885 | state->reqs[0] = kmem_cache_alloc(req_cachep, gfp); | |
886 | if (!state->reqs[0]) | |
0ddf92e8 | 887 | goto fallback; |
fd6fab2c JA |
888 | ret = 1; |
889 | } | |
2579f913 JA |
890 | state->free_reqs = ret - 1; |
891 | state->cur_req = 1; | |
892 | req = state->reqs[0]; | |
893 | } else { | |
894 | req = state->reqs[state->cur_req]; | |
895 | state->free_reqs--; | |
896 | state->cur_req++; | |
2b188cc1 JA |
897 | } |
898 | ||
0ddf92e8 | 899 | got_it: |
1a6b74fc | 900 | req->io = NULL; |
cf6fd4bd | 901 | req->ring_file = NULL; |
60c112b0 | 902 | req->file = NULL; |
2579f913 JA |
903 | req->ctx = ctx; |
904 | req->flags = 0; | |
e65ef56d JA |
905 | /* one is dropped after submission, the other at completion */ |
906 | refcount_set(&req->refs, 2); | |
9e645e11 | 907 | req->result = 0; |
561fb04a | 908 | INIT_IO_WORK(&req->work, io_wq_submit_work); |
2579f913 | 909 | return req; |
0ddf92e8 JA |
910 | fallback: |
911 | req = io_get_fallback_req(ctx); | |
912 | if (req) | |
913 | goto got_it; | |
6805b32e | 914 | percpu_ref_put(&ctx->refs); |
2b188cc1 JA |
915 | return NULL; |
916 | } | |
917 | ||
def596e9 JA |
918 | static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr) |
919 | { | |
920 | if (*nr) { | |
921 | kmem_cache_free_bulk(req_cachep, *nr, reqs); | |
6805b32e | 922 | percpu_ref_put_many(&ctx->refs, *nr); |
def596e9 JA |
923 | *nr = 0; |
924 | } | |
925 | } | |
926 | ||
9e645e11 | 927 | static void __io_free_req(struct io_kiocb *req) |
2b188cc1 | 928 | { |
fcb323cc JA |
929 | struct io_ring_ctx *ctx = req->ctx; |
930 | ||
1a6b74fc JA |
931 | if (req->io) |
932 | kfree(req->io); | |
09bb8394 JA |
933 | if (req->file && !(req->flags & REQ_F_FIXED_FILE)) |
934 | fput(req->file); | |
fcb323cc JA |
935 | if (req->flags & REQ_F_INFLIGHT) { |
936 | unsigned long flags; | |
937 | ||
938 | spin_lock_irqsave(&ctx->inflight_lock, flags); | |
939 | list_del(&req->inflight_entry); | |
940 | if (waitqueue_active(&ctx->inflight_wait)) | |
941 | wake_up(&ctx->inflight_wait); | |
942 | spin_unlock_irqrestore(&ctx->inflight_lock, flags); | |
943 | } | |
944 | percpu_ref_put(&ctx->refs); | |
0ddf92e8 JA |
945 | if (likely(!io_is_fallback_req(req))) |
946 | kmem_cache_free(req_cachep, req); | |
947 | else | |
948 | clear_bit_unlock(0, (unsigned long *) ctx->fallback_req); | |
e65ef56d JA |
949 | } |
950 | ||
a197f664 | 951 | static bool io_link_cancel_timeout(struct io_kiocb *req) |
2665abfd | 952 | { |
a197f664 | 953 | struct io_ring_ctx *ctx = req->ctx; |
2665abfd JA |
954 | int ret; |
955 | ||
2d28390a | 956 | ret = hrtimer_try_to_cancel(&req->io->timeout.timer); |
2665abfd | 957 | if (ret != -1) { |
78e19bbe | 958 | io_cqring_fill_event(req, -ECANCELED); |
2665abfd JA |
959 | io_commit_cqring(ctx); |
960 | req->flags &= ~REQ_F_LINK; | |
ec9c02ad | 961 | io_put_req(req); |
2665abfd JA |
962 | return true; |
963 | } | |
964 | ||
965 | return false; | |
e65ef56d JA |
966 | } |
967 | ||
ba816ad6 | 968 | static void io_req_link_next(struct io_kiocb *req, struct io_kiocb **nxtptr) |
9e645e11 | 969 | { |
2665abfd | 970 | struct io_ring_ctx *ctx = req->ctx; |
2665abfd | 971 | bool wake_ev = false; |
9e645e11 | 972 | |
4d7dd462 JA |
973 | /* Already got next link */ |
974 | if (req->flags & REQ_F_LINK_NEXT) | |
975 | return; | |
976 | ||
9e645e11 JA |
977 | /* |
978 | * The list should never be empty when we are called here. But could | |
979 | * potentially happen if the chain is messed up, check to be on the | |
980 | * safe side. | |
981 | */ | |
4493233e PB |
982 | while (!list_empty(&req->link_list)) { |
983 | struct io_kiocb *nxt = list_first_entry(&req->link_list, | |
984 | struct io_kiocb, link_list); | |
94ae5e77 | 985 | |
4493233e PB |
986 | if (unlikely((req->flags & REQ_F_LINK_TIMEOUT) && |
987 | (nxt->flags & REQ_F_TIMEOUT))) { | |
988 | list_del_init(&nxt->link_list); | |
94ae5e77 | 989 | wake_ev |= io_link_cancel_timeout(nxt); |
94ae5e77 JA |
990 | req->flags &= ~REQ_F_LINK_TIMEOUT; |
991 | continue; | |
992 | } | |
9e645e11 | 993 | |
4493233e PB |
994 | list_del_init(&req->link_list); |
995 | if (!list_empty(&nxt->link_list)) | |
996 | nxt->flags |= REQ_F_LINK; | |
b18fdf71 | 997 | *nxtptr = nxt; |
94ae5e77 | 998 | break; |
9e645e11 | 999 | } |
2665abfd | 1000 | |
4d7dd462 | 1001 | req->flags |= REQ_F_LINK_NEXT; |
2665abfd JA |
1002 | if (wake_ev) |
1003 | io_cqring_ev_posted(ctx); | |
9e645e11 JA |
1004 | } |
1005 | ||
1006 | /* | |
1007 | * Called if REQ_F_LINK is set, and we fail the head request | |
1008 | */ | |
1009 | static void io_fail_links(struct io_kiocb *req) | |
1010 | { | |
2665abfd | 1011 | struct io_ring_ctx *ctx = req->ctx; |
2665abfd JA |
1012 | unsigned long flags; |
1013 | ||
1014 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
9e645e11 JA |
1015 | |
1016 | while (!list_empty(&req->link_list)) { | |
4493233e PB |
1017 | struct io_kiocb *link = list_first_entry(&req->link_list, |
1018 | struct io_kiocb, link_list); | |
9e645e11 | 1019 | |
4493233e | 1020 | list_del_init(&link->link_list); |
c826bd7a | 1021 | trace_io_uring_fail_link(req, link); |
2665abfd JA |
1022 | |
1023 | if ((req->flags & REQ_F_LINK_TIMEOUT) && | |
d625c6ee | 1024 | link->opcode == IORING_OP_LINK_TIMEOUT) { |
a197f664 | 1025 | io_link_cancel_timeout(link); |
2665abfd | 1026 | } else { |
78e19bbe | 1027 | io_cqring_fill_event(link, -ECANCELED); |
978db57e | 1028 | __io_double_put_req(link); |
2665abfd | 1029 | } |
5d960724 | 1030 | req->flags &= ~REQ_F_LINK_TIMEOUT; |
9e645e11 | 1031 | } |
2665abfd JA |
1032 | |
1033 | io_commit_cqring(ctx); | |
1034 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
1035 | io_cqring_ev_posted(ctx); | |
9e645e11 JA |
1036 | } |
1037 | ||
4d7dd462 | 1038 | static void io_req_find_next(struct io_kiocb *req, struct io_kiocb **nxt) |
9e645e11 | 1039 | { |
4d7dd462 | 1040 | if (likely(!(req->flags & REQ_F_LINK))) |
2665abfd | 1041 | return; |
2665abfd | 1042 | |
9e645e11 JA |
1043 | /* |
1044 | * If LINK is set, we have dependent requests in this chain. If we | |
1045 | * didn't fail this request, queue the first one up, moving any other | |
1046 | * dependencies to the next request. In case of failure, fail the rest | |
1047 | * of the chain. | |
1048 | */ | |
2665abfd JA |
1049 | if (req->flags & REQ_F_FAIL_LINK) { |
1050 | io_fail_links(req); | |
7c9e7f0f JA |
1051 | } else if ((req->flags & (REQ_F_LINK_TIMEOUT | REQ_F_COMP_LOCKED)) == |
1052 | REQ_F_LINK_TIMEOUT) { | |
2665abfd JA |
1053 | struct io_ring_ctx *ctx = req->ctx; |
1054 | unsigned long flags; | |
1055 | ||
1056 | /* | |
1057 | * If this is a timeout link, we could be racing with the | |
1058 | * timeout timer. Grab the completion lock for this case to | |
7c9e7f0f | 1059 | * protect against that. |
2665abfd JA |
1060 | */ |
1061 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
1062 | io_req_link_next(req, nxt); | |
1063 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
1064 | } else { | |
1065 | io_req_link_next(req, nxt); | |
9e645e11 | 1066 | } |
4d7dd462 | 1067 | } |
9e645e11 | 1068 | |
c69f8dbe JL |
1069 | static void io_free_req(struct io_kiocb *req) |
1070 | { | |
944e58bf PB |
1071 | struct io_kiocb *nxt = NULL; |
1072 | ||
1073 | io_req_find_next(req, &nxt); | |
70cf9f32 | 1074 | __io_free_req(req); |
944e58bf PB |
1075 | |
1076 | if (nxt) | |
1077 | io_queue_async_work(nxt); | |
c69f8dbe JL |
1078 | } |
1079 | ||
ba816ad6 JA |
1080 | /* |
1081 | * Drop reference to request, return next in chain (if there is one) if this | |
1082 | * was the last reference to this request. | |
1083 | */ | |
f9bd67f6 | 1084 | __attribute__((nonnull)) |
ec9c02ad | 1085 | static void io_put_req_find_next(struct io_kiocb *req, struct io_kiocb **nxtptr) |
e65ef56d | 1086 | { |
f9bd67f6 | 1087 | io_req_find_next(req, nxtptr); |
4d7dd462 | 1088 | |
e65ef56d | 1089 | if (refcount_dec_and_test(&req->refs)) |
4d7dd462 | 1090 | __io_free_req(req); |
2b188cc1 JA |
1091 | } |
1092 | ||
e65ef56d JA |
1093 | static void io_put_req(struct io_kiocb *req) |
1094 | { | |
1095 | if (refcount_dec_and_test(&req->refs)) | |
1096 | io_free_req(req); | |
2b188cc1 JA |
1097 | } |
1098 | ||
978db57e JA |
1099 | /* |
1100 | * Must only be used if we don't need to care about links, usually from | |
1101 | * within the completion handling itself. | |
1102 | */ | |
1103 | static void __io_double_put_req(struct io_kiocb *req) | |
78e19bbe JA |
1104 | { |
1105 | /* drop both submit and complete references */ | |
1106 | if (refcount_sub_and_test(2, &req->refs)) | |
1107 | __io_free_req(req); | |
1108 | } | |
1109 | ||
978db57e JA |
1110 | static void io_double_put_req(struct io_kiocb *req) |
1111 | { | |
1112 | /* drop both submit and complete references */ | |
1113 | if (refcount_sub_and_test(2, &req->refs)) | |
1114 | io_free_req(req); | |
1115 | } | |
1116 | ||
1d7bb1d5 | 1117 | static unsigned io_cqring_events(struct io_ring_ctx *ctx, bool noflush) |
a3a0e43f | 1118 | { |
84f97dc2 JA |
1119 | struct io_rings *rings = ctx->rings; |
1120 | ||
1d7bb1d5 JA |
1121 | /* |
1122 | * noflush == true is from the waitqueue handler, just ensure we wake | |
1123 | * up the task, and the next invocation will flush the entries. We | |
1124 | * cannot safely to it from here. | |
1125 | */ | |
1126 | if (noflush && !list_empty(&ctx->cq_overflow_list)) | |
1127 | return -1U; | |
1128 | ||
1129 | io_cqring_overflow_flush(ctx, false); | |
1130 | ||
a3a0e43f JA |
1131 | /* See comment at the top of this file */ |
1132 | smp_rmb(); | |
75b28aff | 1133 | return READ_ONCE(rings->cq.tail) - READ_ONCE(rings->cq.head); |
a3a0e43f JA |
1134 | } |
1135 | ||
fb5ccc98 PB |
1136 | static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx) |
1137 | { | |
1138 | struct io_rings *rings = ctx->rings; | |
1139 | ||
1140 | /* make sure SQ entry isn't read before tail */ | |
1141 | return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head; | |
1142 | } | |
1143 | ||
def596e9 JA |
1144 | /* |
1145 | * Find and free completed poll iocbs | |
1146 | */ | |
1147 | static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, | |
1148 | struct list_head *done) | |
1149 | { | |
1150 | void *reqs[IO_IOPOLL_BATCH]; | |
1151 | struct io_kiocb *req; | |
09bb8394 | 1152 | int to_free; |
def596e9 | 1153 | |
09bb8394 | 1154 | to_free = 0; |
def596e9 JA |
1155 | while (!list_empty(done)) { |
1156 | req = list_first_entry(done, struct io_kiocb, list); | |
1157 | list_del(&req->list); | |
1158 | ||
78e19bbe | 1159 | io_cqring_fill_event(req, req->result); |
def596e9 JA |
1160 | (*nr_events)++; |
1161 | ||
09bb8394 JA |
1162 | if (refcount_dec_and_test(&req->refs)) { |
1163 | /* If we're not using fixed files, we have to pair the | |
1164 | * completion part with the file put. Use regular | |
1165 | * completions for those, only batch free for fixed | |
9e645e11 | 1166 | * file and non-linked commands. |
09bb8394 | 1167 | */ |
1a6b74fc JA |
1168 | if (((req->flags & (REQ_F_FIXED_FILE|REQ_F_LINK)) == |
1169 | REQ_F_FIXED_FILE) && !io_is_fallback_req(req) && | |
1170 | !req->io) { | |
09bb8394 JA |
1171 | reqs[to_free++] = req; |
1172 | if (to_free == ARRAY_SIZE(reqs)) | |
1173 | io_free_req_many(ctx, reqs, &to_free); | |
6b06314c | 1174 | } else { |
09bb8394 | 1175 | io_free_req(req); |
6b06314c | 1176 | } |
9a56a232 | 1177 | } |
def596e9 | 1178 | } |
def596e9 | 1179 | |
09bb8394 | 1180 | io_commit_cqring(ctx); |
def596e9 JA |
1181 | io_free_req_many(ctx, reqs, &to_free); |
1182 | } | |
1183 | ||
1184 | static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, | |
1185 | long min) | |
1186 | { | |
1187 | struct io_kiocb *req, *tmp; | |
1188 | LIST_HEAD(done); | |
1189 | bool spin; | |
1190 | int ret; | |
1191 | ||
1192 | /* | |
1193 | * Only spin for completions if we don't have multiple devices hanging | |
1194 | * off our complete list, and we're under the requested amount. | |
1195 | */ | |
1196 | spin = !ctx->poll_multi_file && *nr_events < min; | |
1197 | ||
1198 | ret = 0; | |
1199 | list_for_each_entry_safe(req, tmp, &ctx->poll_list, list) { | |
9adbd45d | 1200 | struct kiocb *kiocb = &req->rw.kiocb; |
def596e9 JA |
1201 | |
1202 | /* | |
1203 | * Move completed entries to our local list. If we find a | |
1204 | * request that requires polling, break out and complete | |
1205 | * the done list first, if we have entries there. | |
1206 | */ | |
1207 | if (req->flags & REQ_F_IOPOLL_COMPLETED) { | |
1208 | list_move_tail(&req->list, &done); | |
1209 | continue; | |
1210 | } | |
1211 | if (!list_empty(&done)) | |
1212 | break; | |
1213 | ||
1214 | ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin); | |
1215 | if (ret < 0) | |
1216 | break; | |
1217 | ||
1218 | if (ret && spin) | |
1219 | spin = false; | |
1220 | ret = 0; | |
1221 | } | |
1222 | ||
1223 | if (!list_empty(&done)) | |
1224 | io_iopoll_complete(ctx, nr_events, &done); | |
1225 | ||
1226 | return ret; | |
1227 | } | |
1228 | ||
1229 | /* | |
d195a66e | 1230 | * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a |
def596e9 JA |
1231 | * non-spinning poll check - we'll still enter the driver poll loop, but only |
1232 | * as a non-spinning completion check. | |
1233 | */ | |
1234 | static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events, | |
1235 | long min) | |
1236 | { | |
08f5439f | 1237 | while (!list_empty(&ctx->poll_list) && !need_resched()) { |
def596e9 JA |
1238 | int ret; |
1239 | ||
1240 | ret = io_do_iopoll(ctx, nr_events, min); | |
1241 | if (ret < 0) | |
1242 | return ret; | |
1243 | if (!min || *nr_events >= min) | |
1244 | return 0; | |
1245 | } | |
1246 | ||
1247 | return 1; | |
1248 | } | |
1249 | ||
1250 | /* | |
1251 | * We can't just wait for polled events to come to us, we have to actively | |
1252 | * find and complete them. | |
1253 | */ | |
1254 | static void io_iopoll_reap_events(struct io_ring_ctx *ctx) | |
1255 | { | |
1256 | if (!(ctx->flags & IORING_SETUP_IOPOLL)) | |
1257 | return; | |
1258 | ||
1259 | mutex_lock(&ctx->uring_lock); | |
1260 | while (!list_empty(&ctx->poll_list)) { | |
1261 | unsigned int nr_events = 0; | |
1262 | ||
1263 | io_iopoll_getevents(ctx, &nr_events, 1); | |
08f5439f JA |
1264 | |
1265 | /* | |
1266 | * Ensure we allow local-to-the-cpu processing to take place, | |
1267 | * in this case we need to ensure that we reap all events. | |
1268 | */ | |
1269 | cond_resched(); | |
def596e9 JA |
1270 | } |
1271 | mutex_unlock(&ctx->uring_lock); | |
1272 | } | |
1273 | ||
2b2ed975 JA |
1274 | static int __io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, |
1275 | long min) | |
def596e9 | 1276 | { |
2b2ed975 | 1277 | int iters = 0, ret = 0; |
500f9fba | 1278 | |
def596e9 JA |
1279 | do { |
1280 | int tmin = 0; | |
1281 | ||
a3a0e43f JA |
1282 | /* |
1283 | * Don't enter poll loop if we already have events pending. | |
1284 | * If we do, we can potentially be spinning for commands that | |
1285 | * already triggered a CQE (eg in error). | |
1286 | */ | |
1d7bb1d5 | 1287 | if (io_cqring_events(ctx, false)) |
a3a0e43f JA |
1288 | break; |
1289 | ||
500f9fba JA |
1290 | /* |
1291 | * If a submit got punted to a workqueue, we can have the | |
1292 | * application entering polling for a command before it gets | |
1293 | * issued. That app will hold the uring_lock for the duration | |
1294 | * of the poll right here, so we need to take a breather every | |
1295 | * now and then to ensure that the issue has a chance to add | |
1296 | * the poll to the issued list. Otherwise we can spin here | |
1297 | * forever, while the workqueue is stuck trying to acquire the | |
1298 | * very same mutex. | |
1299 | */ | |
1300 | if (!(++iters & 7)) { | |
1301 | mutex_unlock(&ctx->uring_lock); | |
1302 | mutex_lock(&ctx->uring_lock); | |
1303 | } | |
1304 | ||
def596e9 JA |
1305 | if (*nr_events < min) |
1306 | tmin = min - *nr_events; | |
1307 | ||
1308 | ret = io_iopoll_getevents(ctx, nr_events, tmin); | |
1309 | if (ret <= 0) | |
1310 | break; | |
1311 | ret = 0; | |
1312 | } while (min && !*nr_events && !need_resched()); | |
1313 | ||
2b2ed975 JA |
1314 | return ret; |
1315 | } | |
1316 | ||
1317 | static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, | |
1318 | long min) | |
1319 | { | |
1320 | int ret; | |
1321 | ||
1322 | /* | |
1323 | * We disallow the app entering submit/complete with polling, but we | |
1324 | * still need to lock the ring to prevent racing with polled issue | |
1325 | * that got punted to a workqueue. | |
1326 | */ | |
1327 | mutex_lock(&ctx->uring_lock); | |
1328 | ret = __io_iopoll_check(ctx, nr_events, min); | |
500f9fba | 1329 | mutex_unlock(&ctx->uring_lock); |
def596e9 JA |
1330 | return ret; |
1331 | } | |
1332 | ||
491381ce | 1333 | static void kiocb_end_write(struct io_kiocb *req) |
2b188cc1 | 1334 | { |
491381ce JA |
1335 | /* |
1336 | * Tell lockdep we inherited freeze protection from submission | |
1337 | * thread. | |
1338 | */ | |
1339 | if (req->flags & REQ_F_ISREG) { | |
1340 | struct inode *inode = file_inode(req->file); | |
2b188cc1 | 1341 | |
491381ce | 1342 | __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); |
2b188cc1 | 1343 | } |
491381ce | 1344 | file_end_write(req->file); |
2b188cc1 JA |
1345 | } |
1346 | ||
4e88d6e7 JA |
1347 | static inline void req_set_fail_links(struct io_kiocb *req) |
1348 | { | |
1349 | if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK) | |
1350 | req->flags |= REQ_F_FAIL_LINK; | |
1351 | } | |
1352 | ||
ba816ad6 | 1353 | static void io_complete_rw_common(struct kiocb *kiocb, long res) |
2b188cc1 | 1354 | { |
9adbd45d | 1355 | struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
2b188cc1 | 1356 | |
491381ce JA |
1357 | if (kiocb->ki_flags & IOCB_WRITE) |
1358 | kiocb_end_write(req); | |
2b188cc1 | 1359 | |
4e88d6e7 JA |
1360 | if (res != req->result) |
1361 | req_set_fail_links(req); | |
78e19bbe | 1362 | io_cqring_add_event(req, res); |
ba816ad6 JA |
1363 | } |
1364 | ||
1365 | static void io_complete_rw(struct kiocb *kiocb, long res, long res2) | |
1366 | { | |
9adbd45d | 1367 | struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
ba816ad6 JA |
1368 | |
1369 | io_complete_rw_common(kiocb, res); | |
e65ef56d | 1370 | io_put_req(req); |
2b188cc1 JA |
1371 | } |
1372 | ||
ba816ad6 JA |
1373 | static struct io_kiocb *__io_complete_rw(struct kiocb *kiocb, long res) |
1374 | { | |
9adbd45d | 1375 | struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
ec9c02ad | 1376 | struct io_kiocb *nxt = NULL; |
ba816ad6 JA |
1377 | |
1378 | io_complete_rw_common(kiocb, res); | |
ec9c02ad JL |
1379 | io_put_req_find_next(req, &nxt); |
1380 | ||
1381 | return nxt; | |
2b188cc1 JA |
1382 | } |
1383 | ||
def596e9 JA |
1384 | static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) |
1385 | { | |
9adbd45d | 1386 | struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb); |
def596e9 | 1387 | |
491381ce JA |
1388 | if (kiocb->ki_flags & IOCB_WRITE) |
1389 | kiocb_end_write(req); | |
def596e9 | 1390 | |
4e88d6e7 JA |
1391 | if (res != req->result) |
1392 | req_set_fail_links(req); | |
9e645e11 | 1393 | req->result = res; |
def596e9 JA |
1394 | if (res != -EAGAIN) |
1395 | req->flags |= REQ_F_IOPOLL_COMPLETED; | |
1396 | } | |
1397 | ||
1398 | /* | |
1399 | * After the iocb has been issued, it's safe to be found on the poll list. | |
1400 | * Adding the kiocb to the list AFTER submission ensures that we don't | |
1401 | * find it from a io_iopoll_getevents() thread before the issuer is done | |
1402 | * accessing the kiocb cookie. | |
1403 | */ | |
1404 | static void io_iopoll_req_issued(struct io_kiocb *req) | |
1405 | { | |
1406 | struct io_ring_ctx *ctx = req->ctx; | |
1407 | ||
1408 | /* | |
1409 | * Track whether we have multiple files in our lists. This will impact | |
1410 | * how we do polling eventually, not spinning if we're on potentially | |
1411 | * different devices. | |
1412 | */ | |
1413 | if (list_empty(&ctx->poll_list)) { | |
1414 | ctx->poll_multi_file = false; | |
1415 | } else if (!ctx->poll_multi_file) { | |
1416 | struct io_kiocb *list_req; | |
1417 | ||
1418 | list_req = list_first_entry(&ctx->poll_list, struct io_kiocb, | |
1419 | list); | |
9adbd45d | 1420 | if (list_req->file != req->file) |
def596e9 JA |
1421 | ctx->poll_multi_file = true; |
1422 | } | |
1423 | ||
1424 | /* | |
1425 | * For fast devices, IO may have already completed. If it has, add | |
1426 | * it to the front so we find it first. | |
1427 | */ | |
1428 | if (req->flags & REQ_F_IOPOLL_COMPLETED) | |
1429 | list_add(&req->list, &ctx->poll_list); | |
1430 | else | |
1431 | list_add_tail(&req->list, &ctx->poll_list); | |
1432 | } | |
1433 | ||
3d6770fb | 1434 | static void io_file_put(struct io_submit_state *state) |
9a56a232 | 1435 | { |
3d6770fb | 1436 | if (state->file) { |
9a56a232 JA |
1437 | int diff = state->has_refs - state->used_refs; |
1438 | ||
1439 | if (diff) | |
1440 | fput_many(state->file, diff); | |
1441 | state->file = NULL; | |
1442 | } | |
1443 | } | |
1444 | ||
1445 | /* | |
1446 | * Get as many references to a file as we have IOs left in this submission, | |
1447 | * assuming most submissions are for one file, or at least that each file | |
1448 | * has more than one submission. | |
1449 | */ | |
1450 | static struct file *io_file_get(struct io_submit_state *state, int fd) | |
1451 | { | |
1452 | if (!state) | |
1453 | return fget(fd); | |
1454 | ||
1455 | if (state->file) { | |
1456 | if (state->fd == fd) { | |
1457 | state->used_refs++; | |
1458 | state->ios_left--; | |
1459 | return state->file; | |
1460 | } | |
3d6770fb | 1461 | io_file_put(state); |
9a56a232 JA |
1462 | } |
1463 | state->file = fget_many(fd, state->ios_left); | |
1464 | if (!state->file) | |
1465 | return NULL; | |
1466 | ||
1467 | state->fd = fd; | |
1468 | state->has_refs = state->ios_left; | |
1469 | state->used_refs = 1; | |
1470 | state->ios_left--; | |
1471 | return state->file; | |
1472 | } | |
1473 | ||
2b188cc1 JA |
1474 | /* |
1475 | * If we tracked the file through the SCM inflight mechanism, we could support | |
1476 | * any file. For now, just ensure that anything potentially problematic is done | |
1477 | * inline. | |
1478 | */ | |
1479 | static bool io_file_supports_async(struct file *file) | |
1480 | { | |
1481 | umode_t mode = file_inode(file)->i_mode; | |
1482 | ||
10d59345 | 1483 | if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISSOCK(mode)) |
2b188cc1 JA |
1484 | return true; |
1485 | if (S_ISREG(mode) && file->f_op != &io_uring_fops) | |
1486 | return true; | |
1487 | ||
1488 | return false; | |
1489 | } | |
1490 | ||
3529d8c2 JA |
1491 | static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
1492 | bool force_nonblock) | |
2b188cc1 | 1493 | { |
def596e9 | 1494 | struct io_ring_ctx *ctx = req->ctx; |
9adbd45d | 1495 | struct kiocb *kiocb = &req->rw.kiocb; |
09bb8394 JA |
1496 | unsigned ioprio; |
1497 | int ret; | |
2b188cc1 | 1498 | |
09bb8394 JA |
1499 | if (!req->file) |
1500 | return -EBADF; | |
2b188cc1 | 1501 | |
491381ce JA |
1502 | if (S_ISREG(file_inode(req->file)->i_mode)) |
1503 | req->flags |= REQ_F_ISREG; | |
1504 | ||
2b188cc1 JA |
1505 | kiocb->ki_pos = READ_ONCE(sqe->off); |
1506 | kiocb->ki_flags = iocb_flags(kiocb->ki_filp); | |
1507 | kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); | |
1508 | ||
1509 | ioprio = READ_ONCE(sqe->ioprio); | |
1510 | if (ioprio) { | |
1511 | ret = ioprio_check_cap(ioprio); | |
1512 | if (ret) | |
09bb8394 | 1513 | return ret; |
2b188cc1 JA |
1514 | |
1515 | kiocb->ki_ioprio = ioprio; | |
1516 | } else | |
1517 | kiocb->ki_ioprio = get_current_ioprio(); | |
1518 | ||
1519 | ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); | |
1520 | if (unlikely(ret)) | |
09bb8394 | 1521 | return ret; |
8449eeda SB |
1522 | |
1523 | /* don't allow async punt if RWF_NOWAIT was requested */ | |
491381ce JA |
1524 | if ((kiocb->ki_flags & IOCB_NOWAIT) || |
1525 | (req->file->f_flags & O_NONBLOCK)) | |
8449eeda SB |
1526 | req->flags |= REQ_F_NOWAIT; |
1527 | ||
1528 | if (force_nonblock) | |
2b188cc1 | 1529 | kiocb->ki_flags |= IOCB_NOWAIT; |
8449eeda | 1530 | |
def596e9 | 1531 | if (ctx->flags & IORING_SETUP_IOPOLL) { |
def596e9 JA |
1532 | if (!(kiocb->ki_flags & IOCB_DIRECT) || |
1533 | !kiocb->ki_filp->f_op->iopoll) | |
09bb8394 | 1534 | return -EOPNOTSUPP; |
2b188cc1 | 1535 | |
def596e9 JA |
1536 | kiocb->ki_flags |= IOCB_HIPRI; |
1537 | kiocb->ki_complete = io_complete_rw_iopoll; | |
6873e0bd | 1538 | req->result = 0; |
def596e9 | 1539 | } else { |
09bb8394 JA |
1540 | if (kiocb->ki_flags & IOCB_HIPRI) |
1541 | return -EINVAL; | |
def596e9 JA |
1542 | kiocb->ki_complete = io_complete_rw; |
1543 | } | |
9adbd45d | 1544 | |
3529d8c2 JA |
1545 | req->rw.addr = READ_ONCE(sqe->addr); |
1546 | req->rw.len = READ_ONCE(sqe->len); | |
9adbd45d JA |
1547 | /* we own ->private, reuse it for the buffer index */ |
1548 | req->rw.kiocb.private = (void *) (unsigned long) | |
3529d8c2 | 1549 | READ_ONCE(sqe->buf_index); |
2b188cc1 | 1550 | return 0; |
2b188cc1 JA |
1551 | } |
1552 | ||
1553 | static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) | |
1554 | { | |
1555 | switch (ret) { | |
1556 | case -EIOCBQUEUED: | |
1557 | break; | |
1558 | case -ERESTARTSYS: | |
1559 | case -ERESTARTNOINTR: | |
1560 | case -ERESTARTNOHAND: | |
1561 | case -ERESTART_RESTARTBLOCK: | |
1562 | /* | |
1563 | * We can't just restart the syscall, since previously | |
1564 | * submitted sqes may already be in progress. Just fail this | |
1565 | * IO with EINTR. | |
1566 | */ | |
1567 | ret = -EINTR; | |
1568 | /* fall through */ | |
1569 | default: | |
1570 | kiocb->ki_complete(kiocb, ret, 0); | |
1571 | } | |
1572 | } | |
1573 | ||
ba816ad6 JA |
1574 | static void kiocb_done(struct kiocb *kiocb, ssize_t ret, struct io_kiocb **nxt, |
1575 | bool in_async) | |
1576 | { | |
f9bd67f6 | 1577 | if (in_async && ret >= 0 && kiocb->ki_complete == io_complete_rw) |
ba816ad6 JA |
1578 | *nxt = __io_complete_rw(kiocb, ret); |
1579 | else | |
1580 | io_rw_done(kiocb, ret); | |
1581 | } | |
1582 | ||
9adbd45d | 1583 | static ssize_t io_import_fixed(struct io_kiocb *req, int rw, |
7d009165 | 1584 | struct iov_iter *iter) |
edafccee | 1585 | { |
9adbd45d JA |
1586 | struct io_ring_ctx *ctx = req->ctx; |
1587 | size_t len = req->rw.len; | |
edafccee JA |
1588 | struct io_mapped_ubuf *imu; |
1589 | unsigned index, buf_index; | |
1590 | size_t offset; | |
1591 | u64 buf_addr; | |
1592 | ||
1593 | /* attempt to use fixed buffers without having provided iovecs */ | |
1594 | if (unlikely(!ctx->user_bufs)) | |
1595 | return -EFAULT; | |
1596 | ||
9adbd45d | 1597 | buf_index = (unsigned long) req->rw.kiocb.private; |
edafccee JA |
1598 | if (unlikely(buf_index >= ctx->nr_user_bufs)) |
1599 | return -EFAULT; | |
1600 | ||
1601 | index = array_index_nospec(buf_index, ctx->nr_user_bufs); | |
1602 | imu = &ctx->user_bufs[index]; | |
9adbd45d | 1603 | buf_addr = req->rw.addr; |
edafccee JA |
1604 | |
1605 | /* overflow */ | |
1606 | if (buf_addr + len < buf_addr) | |
1607 | return -EFAULT; | |
1608 | /* not inside the mapped region */ | |
1609 | if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len) | |
1610 | return -EFAULT; | |
1611 | ||
1612 | /* | |
1613 | * May not be a start of buffer, set size appropriately | |
1614 | * and advance us to the beginning. | |
1615 | */ | |
1616 | offset = buf_addr - imu->ubuf; | |
1617 | iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len); | |
bd11b3a3 JA |
1618 | |
1619 | if (offset) { | |
1620 | /* | |
1621 | * Don't use iov_iter_advance() here, as it's really slow for | |
1622 | * using the latter parts of a big fixed buffer - it iterates | |
1623 | * over each segment manually. We can cheat a bit here, because | |
1624 | * we know that: | |
1625 | * | |
1626 | * 1) it's a BVEC iter, we set it up | |
1627 | * 2) all bvecs are PAGE_SIZE in size, except potentially the | |
1628 | * first and last bvec | |
1629 | * | |
1630 | * So just find our index, and adjust the iterator afterwards. | |
1631 | * If the offset is within the first bvec (or the whole first | |
1632 | * bvec, just use iov_iter_advance(). This makes it easier | |
1633 | * since we can just skip the first segment, which may not | |
1634 | * be PAGE_SIZE aligned. | |
1635 | */ | |
1636 | const struct bio_vec *bvec = imu->bvec; | |
1637 | ||
1638 | if (offset <= bvec->bv_len) { | |
1639 | iov_iter_advance(iter, offset); | |
1640 | } else { | |
1641 | unsigned long seg_skip; | |
1642 | ||
1643 | /* skip first vec */ | |
1644 | offset -= bvec->bv_len; | |
1645 | seg_skip = 1 + (offset >> PAGE_SHIFT); | |
1646 | ||
1647 | iter->bvec = bvec + seg_skip; | |
1648 | iter->nr_segs -= seg_skip; | |
99c79f66 | 1649 | iter->count -= bvec->bv_len + offset; |
bd11b3a3 | 1650 | iter->iov_offset = offset & ~PAGE_MASK; |
bd11b3a3 JA |
1651 | } |
1652 | } | |
1653 | ||
5e559561 | 1654 | return len; |
edafccee JA |
1655 | } |
1656 | ||
cf6fd4bd PB |
1657 | static ssize_t io_import_iovec(int rw, struct io_kiocb *req, |
1658 | struct iovec **iovec, struct iov_iter *iter) | |
2b188cc1 | 1659 | { |
9adbd45d JA |
1660 | void __user *buf = u64_to_user_ptr(req->rw.addr); |
1661 | size_t sqe_len = req->rw.len; | |
edafccee JA |
1662 | u8 opcode; |
1663 | ||
d625c6ee | 1664 | opcode = req->opcode; |
7d009165 | 1665 | if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) { |
edafccee | 1666 | *iovec = NULL; |
9adbd45d | 1667 | return io_import_fixed(req, rw, iter); |
edafccee | 1668 | } |
2b188cc1 | 1669 | |
9adbd45d JA |
1670 | /* buffer index only valid with fixed read/write */ |
1671 | if (req->rw.kiocb.private) | |
1672 | return -EINVAL; | |
1673 | ||
f67676d1 JA |
1674 | if (req->io) { |
1675 | struct io_async_rw *iorw = &req->io->rw; | |
1676 | ||
1677 | *iovec = iorw->iov; | |
1678 | iov_iter_init(iter, rw, *iovec, iorw->nr_segs, iorw->size); | |
1679 | if (iorw->iov == iorw->fast_iov) | |
1680 | *iovec = NULL; | |
1681 | return iorw->size; | |
1682 | } | |
1683 | ||
cf6fd4bd | 1684 | if (!req->has_user) |
2b188cc1 JA |
1685 | return -EFAULT; |
1686 | ||
1687 | #ifdef CONFIG_COMPAT | |
cf6fd4bd | 1688 | if (req->ctx->compat) |
2b188cc1 JA |
1689 | return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV, |
1690 | iovec, iter); | |
1691 | #endif | |
1692 | ||
1693 | return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter); | |
1694 | } | |
1695 | ||
31b51510 | 1696 | /* |
32960613 JA |
1697 | * For files that don't have ->read_iter() and ->write_iter(), handle them |
1698 | * by looping over ->read() or ->write() manually. | |
31b51510 | 1699 | */ |
32960613 JA |
1700 | static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb, |
1701 | struct iov_iter *iter) | |
1702 | { | |
1703 | ssize_t ret = 0; | |
1704 | ||
1705 | /* | |
1706 | * Don't support polled IO through this interface, and we can't | |
1707 | * support non-blocking either. For the latter, this just causes | |
1708 | * the kiocb to be handled from an async context. | |
1709 | */ | |
1710 | if (kiocb->ki_flags & IOCB_HIPRI) | |
1711 | return -EOPNOTSUPP; | |
1712 | if (kiocb->ki_flags & IOCB_NOWAIT) | |
1713 | return -EAGAIN; | |
1714 | ||
1715 | while (iov_iter_count(iter)) { | |
311ae9e1 | 1716 | struct iovec iovec; |
32960613 JA |
1717 | ssize_t nr; |
1718 | ||
311ae9e1 PB |
1719 | if (!iov_iter_is_bvec(iter)) { |
1720 | iovec = iov_iter_iovec(iter); | |
1721 | } else { | |
1722 | /* fixed buffers import bvec */ | |
1723 | iovec.iov_base = kmap(iter->bvec->bv_page) | |
1724 | + iter->iov_offset; | |
1725 | iovec.iov_len = min(iter->count, | |
1726 | iter->bvec->bv_len - iter->iov_offset); | |
1727 | } | |
1728 | ||
32960613 JA |
1729 | if (rw == READ) { |
1730 | nr = file->f_op->read(file, iovec.iov_base, | |
1731 | iovec.iov_len, &kiocb->ki_pos); | |
1732 | } else { | |
1733 | nr = file->f_op->write(file, iovec.iov_base, | |
1734 | iovec.iov_len, &kiocb->ki_pos); | |
1735 | } | |
1736 | ||
311ae9e1 PB |
1737 | if (iov_iter_is_bvec(iter)) |
1738 | kunmap(iter->bvec->bv_page); | |
1739 | ||
32960613 JA |
1740 | if (nr < 0) { |
1741 | if (!ret) | |
1742 | ret = nr; | |
1743 | break; | |
1744 | } | |
1745 | ret += nr; | |
1746 | if (nr != iovec.iov_len) | |
1747 | break; | |
1748 | iov_iter_advance(iter, nr); | |
1749 | } | |
1750 | ||
1751 | return ret; | |
1752 | } | |
1753 | ||
b7bb4f7d | 1754 | static void io_req_map_rw(struct io_kiocb *req, ssize_t io_size, |
f67676d1 JA |
1755 | struct iovec *iovec, struct iovec *fast_iov, |
1756 | struct iov_iter *iter) | |
1757 | { | |
1758 | req->io->rw.nr_segs = iter->nr_segs; | |
1759 | req->io->rw.size = io_size; | |
1760 | req->io->rw.iov = iovec; | |
1761 | if (!req->io->rw.iov) { | |
1762 | req->io->rw.iov = req->io->rw.fast_iov; | |
1763 | memcpy(req->io->rw.iov, fast_iov, | |
1764 | sizeof(struct iovec) * iter->nr_segs); | |
1765 | } | |
1766 | } | |
1767 | ||
b7bb4f7d | 1768 | static int io_alloc_async_ctx(struct io_kiocb *req) |
f67676d1 JA |
1769 | { |
1770 | req->io = kmalloc(sizeof(*req->io), GFP_KERNEL); | |
06b76d44 | 1771 | return req->io == NULL; |
b7bb4f7d JA |
1772 | } |
1773 | ||
1774 | static void io_rw_async(struct io_wq_work **workptr) | |
1775 | { | |
1776 | struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); | |
1777 | struct iovec *iov = NULL; | |
1778 | ||
1779 | if (req->io->rw.iov != req->io->rw.fast_iov) | |
1780 | iov = req->io->rw.iov; | |
1781 | io_wq_submit_work(workptr); | |
1782 | kfree(iov); | |
1783 | } | |
1784 | ||
1785 | static int io_setup_async_rw(struct io_kiocb *req, ssize_t io_size, | |
1786 | struct iovec *iovec, struct iovec *fast_iov, | |
1787 | struct iov_iter *iter) | |
1788 | { | |
74566df3 JA |
1789 | if (req->opcode == IORING_OP_READ_FIXED || |
1790 | req->opcode == IORING_OP_WRITE_FIXED) | |
1791 | return 0; | |
b7bb4f7d JA |
1792 | if (!req->io && io_alloc_async_ctx(req)) |
1793 | return -ENOMEM; | |
1794 | ||
1795 | io_req_map_rw(req, io_size, iovec, fast_iov, iter); | |
1796 | req->work.func = io_rw_async; | |
1797 | return 0; | |
f67676d1 JA |
1798 | } |
1799 | ||
3529d8c2 JA |
1800 | static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
1801 | bool force_nonblock) | |
f67676d1 | 1802 | { |
3529d8c2 JA |
1803 | struct io_async_ctx *io; |
1804 | struct iov_iter iter; | |
f67676d1 JA |
1805 | ssize_t ret; |
1806 | ||
3529d8c2 JA |
1807 | ret = io_prep_rw(req, sqe, force_nonblock); |
1808 | if (ret) | |
1809 | return ret; | |
f67676d1 | 1810 | |
3529d8c2 JA |
1811 | if (unlikely(!(req->file->f_mode & FMODE_READ))) |
1812 | return -EBADF; | |
f67676d1 | 1813 | |
3529d8c2 JA |
1814 | if (!req->io) |
1815 | return 0; | |
1816 | ||
1817 | io = req->io; | |
1818 | io->rw.iov = io->rw.fast_iov; | |
1819 | req->io = NULL; | |
1820 | ret = io_import_iovec(READ, req, &io->rw.iov, &iter); | |
1821 | req->io = io; | |
1822 | if (ret < 0) | |
1823 | return ret; | |
1824 | ||
1825 | io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter); | |
1826 | return 0; | |
f67676d1 JA |
1827 | } |
1828 | ||
267bc904 | 1829 | static int io_read(struct io_kiocb *req, struct io_kiocb **nxt, |
8358e3a8 | 1830 | bool force_nonblock) |
2b188cc1 JA |
1831 | { |
1832 | struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; | |
9adbd45d | 1833 | struct kiocb *kiocb = &req->rw.kiocb; |
2b188cc1 | 1834 | struct iov_iter iter; |
31b51510 | 1835 | size_t iov_count; |
f67676d1 | 1836 | ssize_t io_size, ret; |
2b188cc1 | 1837 | |
3529d8c2 | 1838 | ret = io_import_iovec(READ, req, &iovec, &iter); |
06b76d44 JA |
1839 | if (ret < 0) |
1840 | return ret; | |
2b188cc1 | 1841 | |
fd6c2e4c JA |
1842 | /* Ensure we clear previously set non-block flag */ |
1843 | if (!force_nonblock) | |
9adbd45d | 1844 | req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT; |
fd6c2e4c | 1845 | |
797f3f53 | 1846 | req->result = 0; |
f67676d1 | 1847 | io_size = ret; |
9e645e11 | 1848 | if (req->flags & REQ_F_LINK) |
f67676d1 JA |
1849 | req->result = io_size; |
1850 | ||
1851 | /* | |
1852 | * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so | |
1853 | * we know to async punt it even if it was opened O_NONBLOCK | |
1854 | */ | |
9adbd45d | 1855 | if (force_nonblock && !io_file_supports_async(req->file)) { |
f67676d1 JA |
1856 | req->flags |= REQ_F_MUST_PUNT; |
1857 | goto copy_iov; | |
1858 | } | |
9e645e11 | 1859 | |
31b51510 | 1860 | iov_count = iov_iter_count(&iter); |
9adbd45d | 1861 | ret = rw_verify_area(READ, req->file, &kiocb->ki_pos, iov_count); |
2b188cc1 JA |
1862 | if (!ret) { |
1863 | ssize_t ret2; | |
1864 | ||
9adbd45d JA |
1865 | if (req->file->f_op->read_iter) |
1866 | ret2 = call_read_iter(req->file, kiocb, &iter); | |
32960613 | 1867 | else |
9adbd45d | 1868 | ret2 = loop_rw_iter(READ, req->file, kiocb, &iter); |
32960613 | 1869 | |
9d93a3f5 | 1870 | /* Catch -EAGAIN return for forced non-blocking submission */ |
f67676d1 | 1871 | if (!force_nonblock || ret2 != -EAGAIN) { |
cf6fd4bd | 1872 | kiocb_done(kiocb, ret2, nxt, req->in_async); |
f67676d1 JA |
1873 | } else { |
1874 | copy_iov: | |
b7bb4f7d | 1875 | ret = io_setup_async_rw(req, io_size, iovec, |
f67676d1 JA |
1876 | inline_vecs, &iter); |
1877 | if (ret) | |
1878 | goto out_free; | |
1879 | return -EAGAIN; | |
1880 | } | |
2b188cc1 | 1881 | } |
f67676d1 | 1882 | out_free: |
b7bb4f7d JA |
1883 | if (!io_wq_current_is_worker()) |
1884 | kfree(iovec); | |
2b188cc1 JA |
1885 | return ret; |
1886 | } | |
1887 | ||
3529d8c2 JA |
1888 | static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
1889 | bool force_nonblock) | |
f67676d1 | 1890 | { |
3529d8c2 JA |
1891 | struct io_async_ctx *io; |
1892 | struct iov_iter iter; | |
f67676d1 JA |
1893 | ssize_t ret; |
1894 | ||
3529d8c2 JA |
1895 | ret = io_prep_rw(req, sqe, force_nonblock); |
1896 | if (ret) | |
1897 | return ret; | |
f67676d1 | 1898 | |
3529d8c2 JA |
1899 | if (unlikely(!(req->file->f_mode & FMODE_WRITE))) |
1900 | return -EBADF; | |
f67676d1 | 1901 | |
3529d8c2 JA |
1902 | if (!req->io) |
1903 | return 0; | |
1904 | ||
1905 | io = req->io; | |
1906 | io->rw.iov = io->rw.fast_iov; | |
1907 | req->io = NULL; | |
1908 | ret = io_import_iovec(WRITE, req, &io->rw.iov, &iter); | |
1909 | req->io = io; | |
1910 | if (ret < 0) | |
1911 | return ret; | |
1912 | ||
1913 | io_req_map_rw(req, ret, io->rw.iov, io->rw.fast_iov, &iter); | |
1914 | return 0; | |
f67676d1 JA |
1915 | } |
1916 | ||
267bc904 | 1917 | static int io_write(struct io_kiocb *req, struct io_kiocb **nxt, |
8358e3a8 | 1918 | bool force_nonblock) |
2b188cc1 JA |
1919 | { |
1920 | struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; | |
9adbd45d | 1921 | struct kiocb *kiocb = &req->rw.kiocb; |
2b188cc1 | 1922 | struct iov_iter iter; |
31b51510 | 1923 | size_t iov_count; |
f67676d1 | 1924 | ssize_t ret, io_size; |
2b188cc1 | 1925 | |
3529d8c2 | 1926 | ret = io_import_iovec(WRITE, req, &iovec, &iter); |
06b76d44 JA |
1927 | if (ret < 0) |
1928 | return ret; | |
2b188cc1 | 1929 | |
fd6c2e4c JA |
1930 | /* Ensure we clear previously set non-block flag */ |
1931 | if (!force_nonblock) | |
9adbd45d | 1932 | req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT; |
fd6c2e4c | 1933 | |
797f3f53 | 1934 | req->result = 0; |
f67676d1 | 1935 | io_size = ret; |
9e645e11 | 1936 | if (req->flags & REQ_F_LINK) |
f67676d1 | 1937 | req->result = io_size; |
9e645e11 | 1938 | |
f67676d1 JA |
1939 | /* |
1940 | * If the file doesn't support async, mark it as REQ_F_MUST_PUNT so | |
1941 | * we know to async punt it even if it was opened O_NONBLOCK | |
1942 | */ | |
1943 | if (force_nonblock && !io_file_supports_async(req->file)) { | |
1944 | req->flags |= REQ_F_MUST_PUNT; | |
1945 | goto copy_iov; | |
1946 | } | |
31b51510 | 1947 | |
10d59345 JA |
1948 | /* file path doesn't support NOWAIT for non-direct_IO */ |
1949 | if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) && | |
1950 | (req->flags & REQ_F_ISREG)) | |
f67676d1 | 1951 | goto copy_iov; |
31b51510 | 1952 | |
f67676d1 | 1953 | iov_count = iov_iter_count(&iter); |
9adbd45d | 1954 | ret = rw_verify_area(WRITE, req->file, &kiocb->ki_pos, iov_count); |
2b188cc1 | 1955 | if (!ret) { |
9bf7933f RP |
1956 | ssize_t ret2; |
1957 | ||
2b188cc1 JA |
1958 | /* |
1959 | * Open-code file_start_write here to grab freeze protection, | |
1960 | * which will be released by another thread in | |
1961 | * io_complete_rw(). Fool lockdep by telling it the lock got | |
1962 | * released so that it doesn't complain about the held lock when | |
1963 | * we return to userspace. | |
1964 | */ | |
491381ce | 1965 | if (req->flags & REQ_F_ISREG) { |
9adbd45d | 1966 | __sb_start_write(file_inode(req->file)->i_sb, |
2b188cc1 | 1967 | SB_FREEZE_WRITE, true); |
9adbd45d | 1968 | __sb_writers_release(file_inode(req->file)->i_sb, |
2b188cc1 JA |
1969 | SB_FREEZE_WRITE); |
1970 | } | |
1971 | kiocb->ki_flags |= IOCB_WRITE; | |
9bf7933f | 1972 | |
9adbd45d JA |
1973 | if (req->file->f_op->write_iter) |
1974 | ret2 = call_write_iter(req->file, kiocb, &iter); | |
32960613 | 1975 | else |
9adbd45d | 1976 | ret2 = loop_rw_iter(WRITE, req->file, kiocb, &iter); |
f67676d1 | 1977 | if (!force_nonblock || ret2 != -EAGAIN) { |
cf6fd4bd | 1978 | kiocb_done(kiocb, ret2, nxt, req->in_async); |
f67676d1 JA |
1979 | } else { |
1980 | copy_iov: | |
b7bb4f7d | 1981 | ret = io_setup_async_rw(req, io_size, iovec, |
f67676d1 JA |
1982 | inline_vecs, &iter); |
1983 | if (ret) | |
1984 | goto out_free; | |
1985 | return -EAGAIN; | |
1986 | } | |
2b188cc1 | 1987 | } |
31b51510 | 1988 | out_free: |
b7bb4f7d JA |
1989 | if (!io_wq_current_is_worker()) |
1990 | kfree(iovec); | |
2b188cc1 JA |
1991 | return ret; |
1992 | } | |
1993 | ||
1994 | /* | |
1995 | * IORING_OP_NOP just posts a completion event, nothing else. | |
1996 | */ | |
78e19bbe | 1997 | static int io_nop(struct io_kiocb *req) |
2b188cc1 JA |
1998 | { |
1999 | struct io_ring_ctx *ctx = req->ctx; | |
2b188cc1 | 2000 | |
def596e9 JA |
2001 | if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
2002 | return -EINVAL; | |
2003 | ||
78e19bbe | 2004 | io_cqring_add_event(req, 0); |
e65ef56d | 2005 | io_put_req(req); |
2b188cc1 JA |
2006 | return 0; |
2007 | } | |
2008 | ||
3529d8c2 | 2009 | static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
c992fe29 | 2010 | { |
6b06314c | 2011 | struct io_ring_ctx *ctx = req->ctx; |
c992fe29 | 2012 | |
09bb8394 JA |
2013 | if (!req->file) |
2014 | return -EBADF; | |
c992fe29 | 2015 | |
6b06314c | 2016 | if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
def596e9 | 2017 | return -EINVAL; |
edafccee | 2018 | if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) |
c992fe29 CH |
2019 | return -EINVAL; |
2020 | ||
8ed8d3c3 JA |
2021 | req->sync.flags = READ_ONCE(sqe->fsync_flags); |
2022 | if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC)) | |
2023 | return -EINVAL; | |
2024 | ||
2025 | req->sync.off = READ_ONCE(sqe->off); | |
2026 | req->sync.len = READ_ONCE(sqe->len); | |
c992fe29 CH |
2027 | return 0; |
2028 | } | |
2029 | ||
8ed8d3c3 JA |
2030 | static bool io_req_cancelled(struct io_kiocb *req) |
2031 | { | |
2032 | if (req->work.flags & IO_WQ_WORK_CANCEL) { | |
2033 | req_set_fail_links(req); | |
2034 | io_cqring_add_event(req, -ECANCELED); | |
2035 | io_put_req(req); | |
2036 | return true; | |
2037 | } | |
2038 | ||
2039 | return false; | |
2040 | } | |
2041 | ||
78912934 JA |
2042 | static void io_link_work_cb(struct io_wq_work **workptr) |
2043 | { | |
2044 | struct io_wq_work *work = *workptr; | |
2045 | struct io_kiocb *link = work->data; | |
2046 | ||
2047 | io_queue_linked_timeout(link); | |
2048 | work->func = io_wq_submit_work; | |
2049 | } | |
2050 | ||
2051 | static void io_wq_assign_next(struct io_wq_work **workptr, struct io_kiocb *nxt) | |
2052 | { | |
2053 | struct io_kiocb *link; | |
2054 | ||
2055 | io_prep_async_work(nxt, &link); | |
2056 | *workptr = &nxt->work; | |
2057 | if (link) { | |
2058 | nxt->work.flags |= IO_WQ_WORK_CB; | |
2059 | nxt->work.func = io_link_work_cb; | |
2060 | nxt->work.data = link; | |
2061 | } | |
2062 | } | |
2063 | ||
8ed8d3c3 JA |
2064 | static void io_fsync_finish(struct io_wq_work **workptr) |
2065 | { | |
2066 | struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); | |
2067 | loff_t end = req->sync.off + req->sync.len; | |
2068 | struct io_kiocb *nxt = NULL; | |
2069 | int ret; | |
2070 | ||
2071 | if (io_req_cancelled(req)) | |
2072 | return; | |
2073 | ||
9adbd45d | 2074 | ret = vfs_fsync_range(req->file, req->sync.off, |
8ed8d3c3 JA |
2075 | end > 0 ? end : LLONG_MAX, |
2076 | req->sync.flags & IORING_FSYNC_DATASYNC); | |
2077 | if (ret < 0) | |
2078 | req_set_fail_links(req); | |
2079 | io_cqring_add_event(req, ret); | |
2080 | io_put_req_find_next(req, &nxt); | |
2081 | if (nxt) | |
78912934 | 2082 | io_wq_assign_next(workptr, nxt); |
8ed8d3c3 JA |
2083 | } |
2084 | ||
fc4df999 JA |
2085 | static int io_fsync(struct io_kiocb *req, struct io_kiocb **nxt, |
2086 | bool force_nonblock) | |
c992fe29 | 2087 | { |
8ed8d3c3 | 2088 | struct io_wq_work *work, *old_work; |
c992fe29 CH |
2089 | |
2090 | /* fsync always requires a blocking context */ | |
8ed8d3c3 JA |
2091 | if (force_nonblock) { |
2092 | io_put_req(req); | |
2093 | req->work.func = io_fsync_finish; | |
c992fe29 | 2094 | return -EAGAIN; |
8ed8d3c3 | 2095 | } |
c992fe29 | 2096 | |
8ed8d3c3 JA |
2097 | work = old_work = &req->work; |
2098 | io_fsync_finish(&work); | |
2099 | if (work && work != old_work) | |
2100 | *nxt = container_of(work, struct io_kiocb, work); | |
c992fe29 CH |
2101 | return 0; |
2102 | } | |
2103 | ||
3529d8c2 | 2104 | static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
5d17b4a4 JA |
2105 | { |
2106 | struct io_ring_ctx *ctx = req->ctx; | |
5d17b4a4 JA |
2107 | |
2108 | if (!req->file) | |
2109 | return -EBADF; | |
5d17b4a4 JA |
2110 | |
2111 | if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) | |
2112 | return -EINVAL; | |
2113 | if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) | |
2114 | return -EINVAL; | |
2115 | ||
8ed8d3c3 JA |
2116 | req->sync.off = READ_ONCE(sqe->off); |
2117 | req->sync.len = READ_ONCE(sqe->len); | |
2118 | req->sync.flags = READ_ONCE(sqe->sync_range_flags); | |
8ed8d3c3 JA |
2119 | return 0; |
2120 | } | |
2121 | ||
2122 | static void io_sync_file_range_finish(struct io_wq_work **workptr) | |
2123 | { | |
2124 | struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); | |
2125 | struct io_kiocb *nxt = NULL; | |
2126 | int ret; | |
2127 | ||
2128 | if (io_req_cancelled(req)) | |
2129 | return; | |
2130 | ||
9adbd45d | 2131 | ret = sync_file_range(req->file, req->sync.off, req->sync.len, |
8ed8d3c3 JA |
2132 | req->sync.flags); |
2133 | if (ret < 0) | |
2134 | req_set_fail_links(req); | |
2135 | io_cqring_add_event(req, ret); | |
2136 | io_put_req_find_next(req, &nxt); | |
2137 | if (nxt) | |
78912934 | 2138 | io_wq_assign_next(workptr, nxt); |
5d17b4a4 JA |
2139 | } |
2140 | ||
fc4df999 | 2141 | static int io_sync_file_range(struct io_kiocb *req, struct io_kiocb **nxt, |
5d17b4a4 JA |
2142 | bool force_nonblock) |
2143 | { | |
8ed8d3c3 | 2144 | struct io_wq_work *work, *old_work; |
5d17b4a4 JA |
2145 | |
2146 | /* sync_file_range always requires a blocking context */ | |
8ed8d3c3 JA |
2147 | if (force_nonblock) { |
2148 | io_put_req(req); | |
2149 | req->work.func = io_sync_file_range_finish; | |
5d17b4a4 | 2150 | return -EAGAIN; |
8ed8d3c3 | 2151 | } |
5d17b4a4 | 2152 | |
8ed8d3c3 JA |
2153 | work = old_work = &req->work; |
2154 | io_sync_file_range_finish(&work); | |
2155 | if (work && work != old_work) | |
2156 | *nxt = container_of(work, struct io_kiocb, work); | |
5d17b4a4 JA |
2157 | return 0; |
2158 | } | |
2159 | ||
b7bb4f7d JA |
2160 | #if defined(CONFIG_NET) |
2161 | static void io_sendrecv_async(struct io_wq_work **workptr) | |
2162 | { | |
2163 | struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); | |
2164 | struct iovec *iov = NULL; | |
2165 | ||
2166 | if (req->io->rw.iov != req->io->rw.fast_iov) | |
2167 | iov = req->io->msg.iov; | |
2168 | io_wq_submit_work(workptr); | |
2169 | kfree(iov); | |
2170 | } | |
2171 | #endif | |
2172 | ||
3529d8c2 | 2173 | static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
03b1230c | 2174 | { |
0fa03c62 | 2175 | #if defined(CONFIG_NET) |
e47293fd | 2176 | struct io_sr_msg *sr = &req->sr_msg; |
3529d8c2 | 2177 | struct io_async_ctx *io = req->io; |
03b1230c | 2178 | |
e47293fd JA |
2179 | sr->msg_flags = READ_ONCE(sqe->msg_flags); |
2180 | sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr)); | |
3529d8c2 JA |
2181 | |
2182 | if (!io) | |
2183 | return 0; | |
2184 | ||
d9688565 | 2185 | io->msg.iov = io->msg.fast_iov; |
3529d8c2 | 2186 | return sendmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags, |
e47293fd | 2187 | &io->msg.iov); |
03b1230c | 2188 | #else |
e47293fd | 2189 | return -EOPNOTSUPP; |
03b1230c JA |
2190 | #endif |
2191 | } | |
2192 | ||
fc4df999 JA |
2193 | static int io_sendmsg(struct io_kiocb *req, struct io_kiocb **nxt, |
2194 | bool force_nonblock) | |
aa1fa28f | 2195 | { |
03b1230c | 2196 | #if defined(CONFIG_NET) |
0b416c3e | 2197 | struct io_async_msghdr *kmsg = NULL; |
0fa03c62 JA |
2198 | struct socket *sock; |
2199 | int ret; | |
2200 | ||
2201 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
2202 | return -EINVAL; | |
2203 | ||
2204 | sock = sock_from_file(req->file, &ret); | |
2205 | if (sock) { | |
b7bb4f7d | 2206 | struct io_async_ctx io; |
03b1230c | 2207 | struct sockaddr_storage addr; |
0fa03c62 JA |
2208 | unsigned flags; |
2209 | ||
03b1230c | 2210 | if (req->io) { |
0b416c3e JA |
2211 | kmsg = &req->io->msg; |
2212 | kmsg->msg.msg_name = &addr; | |
2213 | /* if iov is set, it's allocated already */ | |
2214 | if (!kmsg->iov) | |
2215 | kmsg->iov = kmsg->fast_iov; | |
2216 | kmsg->msg.msg_iter.iov = kmsg->iov; | |
03b1230c | 2217 | } else { |
3529d8c2 JA |
2218 | struct io_sr_msg *sr = &req->sr_msg; |
2219 | ||
0b416c3e JA |
2220 | kmsg = &io.msg; |
2221 | kmsg->msg.msg_name = &addr; | |
3529d8c2 JA |
2222 | |
2223 | io.msg.iov = io.msg.fast_iov; | |
2224 | ret = sendmsg_copy_msghdr(&io.msg.msg, sr->msg, | |
2225 | sr->msg_flags, &io.msg.iov); | |
03b1230c | 2226 | if (ret) |
3529d8c2 | 2227 | return ret; |
03b1230c | 2228 | } |
0fa03c62 | 2229 | |
e47293fd JA |
2230 | flags = req->sr_msg.msg_flags; |
2231 | if (flags & MSG_DONTWAIT) | |
2232 | req->flags |= REQ_F_NOWAIT; | |
2233 | else if (force_nonblock) | |
2234 | flags |= MSG_DONTWAIT; | |
2235 | ||
0b416c3e | 2236 | ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags); |
03b1230c | 2237 | if (force_nonblock && ret == -EAGAIN) { |
b7bb4f7d JA |
2238 | if (req->io) |
2239 | return -EAGAIN; | |
2240 | if (io_alloc_async_ctx(req)) | |
2241 | return -ENOMEM; | |
2242 | memcpy(&req->io->msg, &io.msg, sizeof(io.msg)); | |
2243 | req->work.func = io_sendrecv_async; | |
0b416c3e | 2244 | return -EAGAIN; |
03b1230c | 2245 | } |
441cdbd5 JA |
2246 | if (ret == -ERESTARTSYS) |
2247 | ret = -EINTR; | |
0fa03c62 JA |
2248 | } |
2249 | ||
b7bb4f7d | 2250 | if (!io_wq_current_is_worker() && kmsg && kmsg->iov != kmsg->fast_iov) |
0b416c3e | 2251 | kfree(kmsg->iov); |
78e19bbe | 2252 | io_cqring_add_event(req, ret); |
4e88d6e7 JA |
2253 | if (ret < 0) |
2254 | req_set_fail_links(req); | |
ec9c02ad | 2255 | io_put_req_find_next(req, nxt); |
5d17b4a4 | 2256 | return 0; |
03b1230c JA |
2257 | #else |
2258 | return -EOPNOTSUPP; | |
aa1fa28f | 2259 | #endif |
03b1230c | 2260 | } |
aa1fa28f | 2261 | |
3529d8c2 JA |
2262 | static int io_recvmsg_prep(struct io_kiocb *req, |
2263 | const struct io_uring_sqe *sqe) | |
aa1fa28f JA |
2264 | { |
2265 | #if defined(CONFIG_NET) | |
e47293fd | 2266 | struct io_sr_msg *sr = &req->sr_msg; |
3529d8c2 JA |
2267 | struct io_async_ctx *io = req->io; |
2268 | ||
2269 | sr->msg_flags = READ_ONCE(sqe->msg_flags); | |
2270 | sr->msg = u64_to_user_ptr(READ_ONCE(sqe->addr)); | |
06b76d44 | 2271 | |
3529d8c2 | 2272 | if (!io) |
06b76d44 | 2273 | return 0; |
03b1230c | 2274 | |
d9688565 | 2275 | io->msg.iov = io->msg.fast_iov; |
3529d8c2 | 2276 | return recvmsg_copy_msghdr(&io->msg.msg, sr->msg, sr->msg_flags, |
e47293fd | 2277 | &io->msg.uaddr, &io->msg.iov); |
aa1fa28f | 2278 | #else |
e47293fd | 2279 | return -EOPNOTSUPP; |
aa1fa28f JA |
2280 | #endif |
2281 | } | |
2282 | ||
fc4df999 JA |
2283 | static int io_recvmsg(struct io_kiocb *req, struct io_kiocb **nxt, |
2284 | bool force_nonblock) | |
aa1fa28f JA |
2285 | { |
2286 | #if defined(CONFIG_NET) | |
0b416c3e | 2287 | struct io_async_msghdr *kmsg = NULL; |
03b1230c JA |
2288 | struct socket *sock; |
2289 | int ret; | |
2290 | ||
2291 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
2292 | return -EINVAL; | |
2293 | ||
2294 | sock = sock_from_file(req->file, &ret); | |
2295 | if (sock) { | |
b7bb4f7d | 2296 | struct io_async_ctx io; |
03b1230c | 2297 | struct sockaddr_storage addr; |
03b1230c JA |
2298 | unsigned flags; |
2299 | ||
03b1230c | 2300 | if (req->io) { |
0b416c3e JA |
2301 | kmsg = &req->io->msg; |
2302 | kmsg->msg.msg_name = &addr; | |
2303 | /* if iov is set, it's allocated already */ | |
2304 | if (!kmsg->iov) | |
2305 | kmsg->iov = kmsg->fast_iov; | |
2306 | kmsg->msg.msg_iter.iov = kmsg->iov; | |
03b1230c | 2307 | } else { |
3529d8c2 JA |
2308 | struct io_sr_msg *sr = &req->sr_msg; |
2309 | ||
0b416c3e JA |
2310 | kmsg = &io.msg; |
2311 | kmsg->msg.msg_name = &addr; | |
3529d8c2 JA |
2312 | |
2313 | io.msg.iov = io.msg.fast_iov; | |
2314 | ret = recvmsg_copy_msghdr(&io.msg.msg, sr->msg, | |
2315 | sr->msg_flags, &io.msg.uaddr, | |
2316 | &io.msg.iov); | |
03b1230c | 2317 | if (ret) |
3529d8c2 | 2318 | return ret; |
03b1230c JA |
2319 | } |
2320 | ||
e47293fd JA |
2321 | flags = req->sr_msg.msg_flags; |
2322 | if (flags & MSG_DONTWAIT) | |
2323 | req->flags |= REQ_F_NOWAIT; | |
2324 | else if (force_nonblock) | |
2325 | flags |= MSG_DONTWAIT; | |
2326 | ||
2327 | ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.msg, | |
2328 | kmsg->uaddr, flags); | |
03b1230c | 2329 | if (force_nonblock && ret == -EAGAIN) { |
b7bb4f7d JA |
2330 | if (req->io) |
2331 | return -EAGAIN; | |
2332 | if (io_alloc_async_ctx(req)) | |
2333 | return -ENOMEM; | |
2334 | memcpy(&req->io->msg, &io.msg, sizeof(io.msg)); | |
2335 | req->work.func = io_sendrecv_async; | |
0b416c3e | 2336 | return -EAGAIN; |
03b1230c JA |
2337 | } |
2338 | if (ret == -ERESTARTSYS) | |
2339 | ret = -EINTR; | |
2340 | } | |
2341 | ||
b7bb4f7d | 2342 | if (!io_wq_current_is_worker() && kmsg && kmsg->iov != kmsg->fast_iov) |
0b416c3e | 2343 | kfree(kmsg->iov); |
03b1230c | 2344 | io_cqring_add_event(req, ret); |
4e88d6e7 JA |
2345 | if (ret < 0) |
2346 | req_set_fail_links(req); | |
03b1230c JA |
2347 | io_put_req_find_next(req, nxt); |
2348 | return 0; | |
0fa03c62 JA |
2349 | #else |
2350 | return -EOPNOTSUPP; | |
2351 | #endif | |
2352 | } | |
5d17b4a4 | 2353 | |
3529d8c2 | 2354 | static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
17f2fe35 JA |
2355 | { |
2356 | #if defined(CONFIG_NET) | |
8ed8d3c3 JA |
2357 | struct io_accept *accept = &req->accept; |
2358 | ||
17f2fe35 JA |
2359 | if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) |
2360 | return -EINVAL; | |
8042d6ce | 2361 | if (sqe->ioprio || sqe->len || sqe->buf_index) |
17f2fe35 JA |
2362 | return -EINVAL; |
2363 | ||
d55e5f5b JA |
2364 | accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
2365 | accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2)); | |
8ed8d3c3 | 2366 | accept->flags = READ_ONCE(sqe->accept_flags); |
8ed8d3c3 JA |
2367 | return 0; |
2368 | #else | |
2369 | return -EOPNOTSUPP; | |
2370 | #endif | |
2371 | } | |
17f2fe35 | 2372 | |
8ed8d3c3 JA |
2373 | #if defined(CONFIG_NET) |
2374 | static int __io_accept(struct io_kiocb *req, struct io_kiocb **nxt, | |
2375 | bool force_nonblock) | |
2376 | { | |
2377 | struct io_accept *accept = &req->accept; | |
2378 | unsigned file_flags; | |
2379 | int ret; | |
2380 | ||
2381 | file_flags = force_nonblock ? O_NONBLOCK : 0; | |
2382 | ret = __sys_accept4_file(req->file, file_flags, accept->addr, | |
2383 | accept->addr_len, accept->flags); | |
2384 | if (ret == -EAGAIN && force_nonblock) | |
17f2fe35 | 2385 | return -EAGAIN; |
8e3cca12 JA |
2386 | if (ret == -ERESTARTSYS) |
2387 | ret = -EINTR; | |
4e88d6e7 JA |
2388 | if (ret < 0) |
2389 | req_set_fail_links(req); | |
78e19bbe | 2390 | io_cqring_add_event(req, ret); |
ec9c02ad | 2391 | io_put_req_find_next(req, nxt); |
17f2fe35 | 2392 | return 0; |
8ed8d3c3 JA |
2393 | } |
2394 | ||
2395 | static void io_accept_finish(struct io_wq_work **workptr) | |
2396 | { | |
2397 | struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work); | |
2398 | struct io_kiocb *nxt = NULL; | |
2399 | ||
2400 | if (io_req_cancelled(req)) | |
2401 | return; | |
2402 | __io_accept(req, &nxt, false); | |
2403 | if (nxt) | |
78912934 | 2404 | io_wq_assign_next(workptr, nxt); |
8ed8d3c3 JA |
2405 | } |
2406 | #endif | |
2407 | ||
2408 | static int io_accept(struct io_kiocb *req, struct io_kiocb **nxt, | |
2409 | bool force_nonblock) | |
2410 | { | |
2411 | #if defined(CONFIG_NET) | |
2412 | int ret; | |
2413 | ||
8ed8d3c3 JA |
2414 | ret = __io_accept(req, nxt, force_nonblock); |
2415 | if (ret == -EAGAIN && force_nonblock) { | |
2416 | req->work.func = io_accept_finish; | |
2417 | req->work.flags |= IO_WQ_WORK_NEEDS_FILES; | |
2418 | io_put_req(req); | |
2419 | return -EAGAIN; | |
2420 | } | |
2421 | return 0; | |
0fa03c62 JA |
2422 | #else |
2423 | return -EOPNOTSUPP; | |
2424 | #endif | |
2425 | } | |
5d17b4a4 | 2426 | |
3529d8c2 | 2427 | static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
f499a021 JA |
2428 | { |
2429 | #if defined(CONFIG_NET) | |
3529d8c2 JA |
2430 | struct io_connect *conn = &req->connect; |
2431 | struct io_async_ctx *io = req->io; | |
f499a021 | 2432 | |
3fbb51c1 JA |
2433 | if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL))) |
2434 | return -EINVAL; | |
2435 | if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags) | |
2436 | return -EINVAL; | |
2437 | ||
3529d8c2 JA |
2438 | conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr)); |
2439 | conn->addr_len = READ_ONCE(sqe->addr2); | |
2440 | ||
2441 | if (!io) | |
2442 | return 0; | |
2443 | ||
2444 | return move_addr_to_kernel(conn->addr, conn->addr_len, | |
3fbb51c1 | 2445 | &io->connect.address); |
f499a021 | 2446 | #else |
3fbb51c1 | 2447 | return -EOPNOTSUPP; |
f499a021 JA |
2448 | #endif |
2449 | } | |
2450 | ||
fc4df999 JA |
2451 | static int io_connect(struct io_kiocb *req, struct io_kiocb **nxt, |
2452 | bool force_nonblock) | |
f8e85cf2 JA |
2453 | { |
2454 | #if defined(CONFIG_NET) | |
f499a021 | 2455 | struct io_async_ctx __io, *io; |
f8e85cf2 | 2456 | unsigned file_flags; |
3fbb51c1 | 2457 | int ret; |
f8e85cf2 | 2458 | |
f499a021 JA |
2459 | if (req->io) { |
2460 | io = req->io; | |
2461 | } else { | |
3529d8c2 JA |
2462 | ret = move_addr_to_kernel(req->connect.addr, |
2463 | req->connect.addr_len, | |
2464 | &__io.connect.address); | |
f499a021 JA |
2465 | if (ret) |
2466 | goto out; | |
2467 | io = &__io; | |
2468 | } | |
2469 | ||
3fbb51c1 JA |
2470 | file_flags = force_nonblock ? O_NONBLOCK : 0; |
2471 | ||
2472 | ret = __sys_connect_file(req->file, &io->connect.address, | |
2473 | req->connect.addr_len, file_flags); | |
87f80d62 | 2474 | if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) { |
b7bb4f7d JA |
2475 | if (req->io) |
2476 | return -EAGAIN; | |
2477 | if (io_alloc_async_ctx(req)) { | |
f499a021 JA |
2478 | ret = -ENOMEM; |
2479 | goto out; | |
2480 | } | |
b7bb4f7d | 2481 | memcpy(&req->io->connect, &__io.connect, sizeof(__io.connect)); |
f8e85cf2 | 2482 | return -EAGAIN; |
f499a021 | 2483 | } |
f8e85cf2 JA |
2484 | if (ret == -ERESTARTSYS) |
2485 | ret = -EINTR; | |
f499a021 | 2486 | out: |
4e88d6e7 JA |
2487 | if (ret < 0) |
2488 | req_set_fail_links(req); | |
f8e85cf2 JA |
2489 | io_cqring_add_event(req, ret); |
2490 | io_put_req_find_next(req, nxt); | |
2491 | return 0; | |
2492 | #else | |
2493 | return -EOPNOTSUPP; | |
2494 | #endif | |
2495 | } | |
2496 | ||
221c5eb2 JA |
2497 | static void io_poll_remove_one(struct io_kiocb *req) |
2498 | { | |
2499 | struct io_poll_iocb *poll = &req->poll; | |
2500 | ||
2501 | spin_lock(&poll->head->lock); | |
2502 | WRITE_ONCE(poll->canceled, true); | |
392edb45 JA |
2503 | if (!list_empty(&poll->wait.entry)) { |
2504 | list_del_init(&poll->wait.entry); | |
a197f664 | 2505 | io_queue_async_work(req); |
221c5eb2 JA |
2506 | } |
2507 | spin_unlock(&poll->head->lock); | |
78076bb6 | 2508 | hash_del(&req->hash_node); |
221c5eb2 JA |
2509 | } |
2510 | ||
2511 | static void io_poll_remove_all(struct io_ring_ctx *ctx) | |
2512 | { | |
78076bb6 | 2513 | struct hlist_node *tmp; |
221c5eb2 | 2514 | struct io_kiocb *req; |
78076bb6 | 2515 | int i; |
221c5eb2 JA |
2516 | |
2517 | spin_lock_irq(&ctx->completion_lock); | |
78076bb6 JA |
2518 | for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) { |
2519 | struct hlist_head *list; | |
2520 | ||
2521 | list = &ctx->cancel_hash[i]; | |
2522 | hlist_for_each_entry_safe(req, tmp, list, hash_node) | |
2523 | io_poll_remove_one(req); | |
221c5eb2 JA |
2524 | } |
2525 | spin_unlock_irq(&ctx->completion_lock); | |
2526 | } | |
2527 | ||
47f46768 JA |
2528 | static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr) |
2529 | { | |
78076bb6 | 2530 | struct hlist_head *list; |
47f46768 JA |
2531 | struct io_kiocb *req; |
2532 | ||
78076bb6 JA |
2533 | list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)]; |
2534 | hlist_for_each_entry(req, list, hash_node) { | |
2535 | if (sqe_addr == req->user_data) { | |
eac406c6 JA |
2536 | io_poll_remove_one(req); |
2537 | return 0; | |
2538 | } | |
47f46768 JA |
2539 | } |
2540 | ||
2541 | return -ENOENT; | |
2542 | } | |
2543 | ||
3529d8c2 JA |
2544 | static int io_poll_remove_prep(struct io_kiocb *req, |
2545 | const struct io_uring_sqe *sqe) | |
0969e783 | 2546 | { |
0969e783 JA |
2547 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
2548 | return -EINVAL; | |
2549 | if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index || | |
2550 | sqe->poll_events) | |
2551 | return -EINVAL; | |
2552 | ||
2553 | req->poll.addr = READ_ONCE(sqe->addr); | |
0969e783 JA |
2554 | return 0; |
2555 | } | |
2556 | ||
221c5eb2 JA |
2557 | /* |
2558 | * Find a running poll command that matches one specified in sqe->addr, | |
2559 | * and remove it if found. | |
2560 | */ | |
fc4df999 | 2561 | static int io_poll_remove(struct io_kiocb *req) |
221c5eb2 JA |
2562 | { |
2563 | struct io_ring_ctx *ctx = req->ctx; | |
0969e783 | 2564 | u64 addr; |
47f46768 | 2565 | int ret; |
221c5eb2 | 2566 | |
0969e783 | 2567 | addr = req->poll.addr; |
221c5eb2 | 2568 | spin_lock_irq(&ctx->completion_lock); |
0969e783 | 2569 | ret = io_poll_cancel(ctx, addr); |
221c5eb2 JA |
2570 | spin_unlock_irq(&ctx->completion_lock); |
2571 | ||
78e19bbe | 2572 | io_cqring_add_event(req, ret); |
4e88d6e7 JA |
2573 | if (ret < 0) |
2574 | req_set_fail_links(req); | |
e65ef56d | 2575 | io_put_req(req); |
221c5eb2 JA |
2576 | return 0; |
2577 | } | |
2578 | ||
b0dd8a41 | 2579 | static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error) |
221c5eb2 | 2580 | { |
a197f664 JL |
2581 | struct io_ring_ctx *ctx = req->ctx; |
2582 | ||
8c838788 | 2583 | req->poll.done = true; |
b0dd8a41 JA |
2584 | if (error) |
2585 | io_cqring_fill_event(req, error); | |
2586 | else | |
2587 | io_cqring_fill_event(req, mangle_poll(mask)); | |
8c838788 | 2588 | io_commit_cqring(ctx); |
221c5eb2 JA |
2589 | } |
2590 | ||
561fb04a | 2591 | static void io_poll_complete_work(struct io_wq_work **workptr) |
221c5eb2 | 2592 | { |
561fb04a | 2593 | struct io_wq_work *work = *workptr; |
221c5eb2 JA |
2594 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
2595 | struct io_poll_iocb *poll = &req->poll; | |
2596 | struct poll_table_struct pt = { ._key = poll->events }; | |
2597 | struct io_ring_ctx *ctx = req->ctx; | |
89723d0b | 2598 | struct io_kiocb *nxt = NULL; |
221c5eb2 | 2599 | __poll_t mask = 0; |
b0dd8a41 | 2600 | int ret = 0; |
221c5eb2 | 2601 | |
b0dd8a41 | 2602 | if (work->flags & IO_WQ_WORK_CANCEL) { |
561fb04a | 2603 | WRITE_ONCE(poll->canceled, true); |
b0dd8a41 JA |
2604 | ret = -ECANCELED; |
2605 | } else if (READ_ONCE(poll->canceled)) { | |
2606 | ret = -ECANCELED; | |
2607 | } | |
561fb04a | 2608 | |
b0dd8a41 | 2609 | if (ret != -ECANCELED) |
221c5eb2 JA |
2610 | mask = vfs_poll(poll->file, &pt) & poll->events; |
2611 | ||
2612 | /* | |
2613 | * Note that ->ki_cancel callers also delete iocb from active_reqs after | |
2614 | * calling ->ki_cancel. We need the ctx_lock roundtrip here to | |
2615 | * synchronize with them. In the cancellation case the list_del_init | |
2616 | * itself is not actually needed, but harmless so we keep it in to | |
2617 | * avoid further branches in the fast path. | |
2618 | */ | |
2619 | spin_lock_irq(&ctx->completion_lock); | |
b0dd8a41 | 2620 | if (!mask && ret != -ECANCELED) { |
392edb45 | 2621 | add_wait_queue(poll->head, &poll->wait); |
221c5eb2 JA |
2622 | spin_unlock_irq(&ctx->completion_lock); |
2623 | return; | |
2624 | } | |
78076bb6 | 2625 | hash_del(&req->hash_node); |
b0dd8a41 | 2626 | io_poll_complete(req, mask, ret); |
221c5eb2 JA |
2627 | spin_unlock_irq(&ctx->completion_lock); |
2628 | ||
8c838788 | 2629 | io_cqring_ev_posted(ctx); |
89723d0b | 2630 | |
4e88d6e7 JA |
2631 | if (ret < 0) |
2632 | req_set_fail_links(req); | |
ec9c02ad | 2633 | io_put_req_find_next(req, &nxt); |
89723d0b | 2634 | if (nxt) |
78912934 | 2635 | io_wq_assign_next(workptr, nxt); |
221c5eb2 JA |
2636 | } |
2637 | ||
2638 | static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, | |
2639 | void *key) | |
2640 | { | |
e944475e | 2641 | struct io_poll_iocb *poll = wait->private; |
221c5eb2 JA |
2642 | struct io_kiocb *req = container_of(poll, struct io_kiocb, poll); |
2643 | struct io_ring_ctx *ctx = req->ctx; | |
2644 | __poll_t mask = key_to_poll(key); | |
8c838788 | 2645 | unsigned long flags; |
221c5eb2 JA |
2646 | |
2647 | /* for instances that support it check for an event match first: */ | |
8c838788 JA |
2648 | if (mask && !(mask & poll->events)) |
2649 | return 0; | |
221c5eb2 | 2650 | |
392edb45 | 2651 | list_del_init(&poll->wait.entry); |
221c5eb2 | 2652 | |
7c9e7f0f JA |
2653 | /* |
2654 | * Run completion inline if we can. We're using trylock here because | |
2655 | * we are violating the completion_lock -> poll wq lock ordering. | |
2656 | * If we have a link timeout we're going to need the completion_lock | |
2657 | * for finalizing the request, mark us as having grabbed that already. | |
2658 | */ | |
8c838788 | 2659 | if (mask && spin_trylock_irqsave(&ctx->completion_lock, flags)) { |
78076bb6 | 2660 | hash_del(&req->hash_node); |
b0dd8a41 | 2661 | io_poll_complete(req, mask, 0); |
7c9e7f0f JA |
2662 | req->flags |= REQ_F_COMP_LOCKED; |
2663 | io_put_req(req); | |
8c838788 | 2664 | spin_unlock_irqrestore(&ctx->completion_lock, flags); |
221c5eb2 | 2665 | |
8c838788 | 2666 | io_cqring_ev_posted(ctx); |
8c838788 | 2667 | } else { |
a197f664 | 2668 | io_queue_async_work(req); |
221c5eb2 JA |
2669 | } |
2670 | ||
221c5eb2 JA |
2671 | return 1; |
2672 | } | |
2673 | ||
2674 | struct io_poll_table { | |
2675 | struct poll_table_struct pt; | |
2676 | struct io_kiocb *req; | |
2677 | int error; | |
2678 | }; | |
2679 | ||
2680 | static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, | |
2681 | struct poll_table_struct *p) | |
2682 | { | |
2683 | struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); | |
2684 | ||
2685 | if (unlikely(pt->req->poll.head)) { | |
2686 | pt->error = -EINVAL; | |
2687 | return; | |
2688 | } | |
2689 | ||
2690 | pt->error = 0; | |
2691 | pt->req->poll.head = head; | |
392edb45 | 2692 | add_wait_queue(head, &pt->req->poll.wait); |
221c5eb2 JA |
2693 | } |
2694 | ||
eac406c6 JA |
2695 | static void io_poll_req_insert(struct io_kiocb *req) |
2696 | { | |
2697 | struct io_ring_ctx *ctx = req->ctx; | |
78076bb6 JA |
2698 | struct hlist_head *list; |
2699 | ||
2700 | list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)]; | |
2701 | hlist_add_head(&req->hash_node, list); | |
eac406c6 JA |
2702 | } |
2703 | ||
3529d8c2 | 2704 | static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
221c5eb2 JA |
2705 | { |
2706 | struct io_poll_iocb *poll = &req->poll; | |
221c5eb2 | 2707 | u16 events; |
221c5eb2 JA |
2708 | |
2709 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
2710 | return -EINVAL; | |
2711 | if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index) | |
2712 | return -EINVAL; | |
09bb8394 JA |
2713 | if (!poll->file) |
2714 | return -EBADF; | |
221c5eb2 | 2715 | |
221c5eb2 JA |
2716 | events = READ_ONCE(sqe->poll_events); |
2717 | poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP; | |
0969e783 JA |
2718 | return 0; |
2719 | } | |
2720 | ||
2721 | static int io_poll_add(struct io_kiocb *req, struct io_kiocb **nxt) | |
2722 | { | |
2723 | struct io_poll_iocb *poll = &req->poll; | |
2724 | struct io_ring_ctx *ctx = req->ctx; | |
2725 | struct io_poll_table ipt; | |
2726 | bool cancel = false; | |
2727 | __poll_t mask; | |
0969e783 JA |
2728 | |
2729 | INIT_IO_WORK(&req->work, io_poll_complete_work); | |
78076bb6 | 2730 | INIT_HLIST_NODE(&req->hash_node); |
221c5eb2 | 2731 | |
221c5eb2 | 2732 | poll->head = NULL; |
8c838788 | 2733 | poll->done = false; |
221c5eb2 JA |
2734 | poll->canceled = false; |
2735 | ||
2736 | ipt.pt._qproc = io_poll_queue_proc; | |
2737 | ipt.pt._key = poll->events; | |
2738 | ipt.req = req; | |
2739 | ipt.error = -EINVAL; /* same as no support for IOCB_CMD_POLL */ | |
2740 | ||
2741 | /* initialized the list so that we can do list_empty checks */ | |
392edb45 JA |
2742 | INIT_LIST_HEAD(&poll->wait.entry); |
2743 | init_waitqueue_func_entry(&poll->wait, io_poll_wake); | |
2744 | poll->wait.private = poll; | |
221c5eb2 | 2745 | |
36703247 JA |
2746 | INIT_LIST_HEAD(&req->list); |
2747 | ||
221c5eb2 | 2748 | mask = vfs_poll(poll->file, &ipt.pt) & poll->events; |
221c5eb2 JA |
2749 | |
2750 | spin_lock_irq(&ctx->completion_lock); | |
8c838788 JA |
2751 | if (likely(poll->head)) { |
2752 | spin_lock(&poll->head->lock); | |
392edb45 | 2753 | if (unlikely(list_empty(&poll->wait.entry))) { |
8c838788 JA |
2754 | if (ipt.error) |
2755 | cancel = true; | |
2756 | ipt.error = 0; | |
2757 | mask = 0; | |
2758 | } | |
2759 | if (mask || ipt.error) | |
392edb45 | 2760 | list_del_init(&poll->wait.entry); |
8c838788 JA |
2761 | else if (cancel) |
2762 | WRITE_ONCE(poll->canceled, true); | |
2763 | else if (!poll->done) /* actually waiting for an event */ | |
eac406c6 | 2764 | io_poll_req_insert(req); |
8c838788 JA |
2765 | spin_unlock(&poll->head->lock); |
2766 | } | |
2767 | if (mask) { /* no async, we'd stolen it */ | |
221c5eb2 | 2768 | ipt.error = 0; |
b0dd8a41 | 2769 | io_poll_complete(req, mask, 0); |
221c5eb2 | 2770 | } |
221c5eb2 JA |
2771 | spin_unlock_irq(&ctx->completion_lock); |
2772 | ||
8c838788 JA |
2773 | if (mask) { |
2774 | io_cqring_ev_posted(ctx); | |
ec9c02ad | 2775 | io_put_req_find_next(req, nxt); |
221c5eb2 | 2776 | } |
8c838788 | 2777 | return ipt.error; |
221c5eb2 JA |
2778 | } |
2779 | ||
5262f567 JA |
2780 | static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) |
2781 | { | |
ad8a48ac JA |
2782 | struct io_timeout_data *data = container_of(timer, |
2783 | struct io_timeout_data, timer); | |
2784 | struct io_kiocb *req = data->req; | |
2785 | struct io_ring_ctx *ctx = req->ctx; | |
5262f567 JA |
2786 | unsigned long flags; |
2787 | ||
5262f567 JA |
2788 | atomic_inc(&ctx->cq_timeouts); |
2789 | ||
2790 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
ef03681a | 2791 | /* |
11365043 JA |
2792 | * We could be racing with timeout deletion. If the list is empty, |
2793 | * then timeout lookup already found it and will be handling it. | |
ef03681a | 2794 | */ |
842f9612 | 2795 | if (!list_empty(&req->list)) { |
11365043 | 2796 | struct io_kiocb *prev; |
5262f567 | 2797 | |
11365043 JA |
2798 | /* |
2799 | * Adjust the reqs sequence before the current one because it | |
d195a66e | 2800 | * will consume a slot in the cq_ring and the cq_tail |
11365043 JA |
2801 | * pointer will be increased, otherwise other timeout reqs may |
2802 | * return in advance without waiting for enough wait_nr. | |
2803 | */ | |
2804 | prev = req; | |
2805 | list_for_each_entry_continue_reverse(prev, &ctx->timeout_list, list) | |
2806 | prev->sequence++; | |
11365043 | 2807 | list_del_init(&req->list); |
11365043 | 2808 | } |
5262f567 | 2809 | |
78e19bbe | 2810 | io_cqring_fill_event(req, -ETIME); |
5262f567 JA |
2811 | io_commit_cqring(ctx); |
2812 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
2813 | ||
2814 | io_cqring_ev_posted(ctx); | |
4e88d6e7 | 2815 | req_set_fail_links(req); |
5262f567 JA |
2816 | io_put_req(req); |
2817 | return HRTIMER_NORESTART; | |
2818 | } | |
2819 | ||
47f46768 JA |
2820 | static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data) |
2821 | { | |
2822 | struct io_kiocb *req; | |
2823 | int ret = -ENOENT; | |
2824 | ||
2825 | list_for_each_entry(req, &ctx->timeout_list, list) { | |
2826 | if (user_data == req->user_data) { | |
2827 | list_del_init(&req->list); | |
2828 | ret = 0; | |
2829 | break; | |
2830 | } | |
2831 | } | |
2832 | ||
2833 | if (ret == -ENOENT) | |
2834 | return ret; | |
2835 | ||
2d28390a | 2836 | ret = hrtimer_try_to_cancel(&req->io->timeout.timer); |
47f46768 JA |
2837 | if (ret == -1) |
2838 | return -EALREADY; | |
2839 | ||
4e88d6e7 | 2840 | req_set_fail_links(req); |
47f46768 JA |
2841 | io_cqring_fill_event(req, -ECANCELED); |
2842 | io_put_req(req); | |
2843 | return 0; | |
2844 | } | |
2845 | ||
3529d8c2 JA |
2846 | static int io_timeout_remove_prep(struct io_kiocb *req, |
2847 | const struct io_uring_sqe *sqe) | |
b29472ee | 2848 | { |
b29472ee JA |
2849 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
2850 | return -EINVAL; | |
2851 | if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->len) | |
2852 | return -EINVAL; | |
2853 | ||
2854 | req->timeout.addr = READ_ONCE(sqe->addr); | |
2855 | req->timeout.flags = READ_ONCE(sqe->timeout_flags); | |
2856 | if (req->timeout.flags) | |
2857 | return -EINVAL; | |
2858 | ||
b29472ee JA |
2859 | return 0; |
2860 | } | |
2861 | ||
11365043 JA |
2862 | /* |
2863 | * Remove or update an existing timeout command | |
2864 | */ | |
fc4df999 | 2865 | static int io_timeout_remove(struct io_kiocb *req) |
11365043 JA |
2866 | { |
2867 | struct io_ring_ctx *ctx = req->ctx; | |
47f46768 | 2868 | int ret; |
11365043 | 2869 | |
11365043 | 2870 | spin_lock_irq(&ctx->completion_lock); |
b29472ee | 2871 | ret = io_timeout_cancel(ctx, req->timeout.addr); |
11365043 | 2872 | |
47f46768 | 2873 | io_cqring_fill_event(req, ret); |
11365043 JA |
2874 | io_commit_cqring(ctx); |
2875 | spin_unlock_irq(&ctx->completion_lock); | |
5262f567 | 2876 | io_cqring_ev_posted(ctx); |
4e88d6e7 JA |
2877 | if (ret < 0) |
2878 | req_set_fail_links(req); | |
ec9c02ad | 2879 | io_put_req(req); |
11365043 | 2880 | return 0; |
5262f567 JA |
2881 | } |
2882 | ||
3529d8c2 | 2883 | static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
2d28390a | 2884 | bool is_timeout_link) |
5262f567 | 2885 | { |
ad8a48ac | 2886 | struct io_timeout_data *data; |
a41525ab | 2887 | unsigned flags; |
5262f567 | 2888 | |
ad8a48ac | 2889 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
5262f567 | 2890 | return -EINVAL; |
ad8a48ac | 2891 | if (sqe->ioprio || sqe->buf_index || sqe->len != 1) |
a41525ab | 2892 | return -EINVAL; |
2d28390a JA |
2893 | if (sqe->off && is_timeout_link) |
2894 | return -EINVAL; | |
a41525ab JA |
2895 | flags = READ_ONCE(sqe->timeout_flags); |
2896 | if (flags & ~IORING_TIMEOUT_ABS) | |
5262f567 | 2897 | return -EINVAL; |
bdf20073 | 2898 | |
26a61679 JA |
2899 | req->timeout.count = READ_ONCE(sqe->off); |
2900 | ||
3529d8c2 | 2901 | if (!req->io && io_alloc_async_ctx(req)) |
26a61679 JA |
2902 | return -ENOMEM; |
2903 | ||
2904 | data = &req->io->timeout; | |
ad8a48ac | 2905 | data->req = req; |
ad8a48ac JA |
2906 | req->flags |= REQ_F_TIMEOUT; |
2907 | ||
2908 | if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr))) | |
5262f567 JA |
2909 | return -EFAULT; |
2910 | ||
11365043 | 2911 | if (flags & IORING_TIMEOUT_ABS) |
ad8a48ac | 2912 | data->mode = HRTIMER_MODE_ABS; |
11365043 | 2913 | else |
ad8a48ac | 2914 | data->mode = HRTIMER_MODE_REL; |
11365043 | 2915 | |
ad8a48ac JA |
2916 | hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode); |
2917 | return 0; | |
2918 | } | |
2919 | ||
fc4df999 | 2920 | static int io_timeout(struct io_kiocb *req) |
ad8a48ac JA |
2921 | { |
2922 | unsigned count; | |
2923 | struct io_ring_ctx *ctx = req->ctx; | |
2924 | struct io_timeout_data *data; | |
2925 | struct list_head *entry; | |
2926 | unsigned span = 0; | |
ad8a48ac | 2927 | |
2d28390a | 2928 | data = &req->io->timeout; |
93bd25bb | 2929 | |
5262f567 JA |
2930 | /* |
2931 | * sqe->off holds how many events that need to occur for this | |
93bd25bb JA |
2932 | * timeout event to be satisfied. If it isn't set, then this is |
2933 | * a pure timeout request, sequence isn't used. | |
5262f567 | 2934 | */ |
26a61679 | 2935 | count = req->timeout.count; |
93bd25bb JA |
2936 | if (!count) { |
2937 | req->flags |= REQ_F_TIMEOUT_NOSEQ; | |
2938 | spin_lock_irq(&ctx->completion_lock); | |
2939 | entry = ctx->timeout_list.prev; | |
2940 | goto add; | |
2941 | } | |
5262f567 JA |
2942 | |
2943 | req->sequence = ctx->cached_sq_head + count - 1; | |
2d28390a | 2944 | data->seq_offset = count; |
5262f567 JA |
2945 | |
2946 | /* | |
2947 | * Insertion sort, ensuring the first entry in the list is always | |
2948 | * the one we need first. | |
2949 | */ | |
5262f567 JA |
2950 | spin_lock_irq(&ctx->completion_lock); |
2951 | list_for_each_prev(entry, &ctx->timeout_list) { | |
2952 | struct io_kiocb *nxt = list_entry(entry, struct io_kiocb, list); | |
5da0fb1a | 2953 | unsigned nxt_sq_head; |
2954 | long long tmp, tmp_nxt; | |
2d28390a | 2955 | u32 nxt_offset = nxt->io->timeout.seq_offset; |
5262f567 | 2956 | |
93bd25bb JA |
2957 | if (nxt->flags & REQ_F_TIMEOUT_NOSEQ) |
2958 | continue; | |
2959 | ||
5da0fb1a | 2960 | /* |
2961 | * Since cached_sq_head + count - 1 can overflow, use type long | |
2962 | * long to store it. | |
2963 | */ | |
2964 | tmp = (long long)ctx->cached_sq_head + count - 1; | |
cc42e0ac PB |
2965 | nxt_sq_head = nxt->sequence - nxt_offset + 1; |
2966 | tmp_nxt = (long long)nxt_sq_head + nxt_offset - 1; | |
5da0fb1a | 2967 | |
2968 | /* | |
2969 | * cached_sq_head may overflow, and it will never overflow twice | |
2970 | * once there is some timeout req still be valid. | |
2971 | */ | |
2972 | if (ctx->cached_sq_head < nxt_sq_head) | |
8b07a65a | 2973 | tmp += UINT_MAX; |
5da0fb1a | 2974 | |
a1f58ba4 | 2975 | if (tmp > tmp_nxt) |
5262f567 | 2976 | break; |
a1f58ba4 | 2977 | |
2978 | /* | |
2979 | * Sequence of reqs after the insert one and itself should | |
2980 | * be adjusted because each timeout req consumes a slot. | |
2981 | */ | |
2982 | span++; | |
2983 | nxt->sequence++; | |
5262f567 | 2984 | } |
a1f58ba4 | 2985 | req->sequence -= span; |
93bd25bb | 2986 | add: |
5262f567 | 2987 | list_add(&req->list, entry); |
ad8a48ac JA |
2988 | data->timer.function = io_timeout_fn; |
2989 | hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode); | |
5262f567 | 2990 | spin_unlock_irq(&ctx->completion_lock); |
5262f567 JA |
2991 | return 0; |
2992 | } | |
5262f567 | 2993 | |
62755e35 JA |
2994 | static bool io_cancel_cb(struct io_wq_work *work, void *data) |
2995 | { | |
2996 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
2997 | ||
2998 | return req->user_data == (unsigned long) data; | |
2999 | } | |
3000 | ||
e977d6d3 | 3001 | static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr) |
62755e35 | 3002 | { |
62755e35 | 3003 | enum io_wq_cancel cancel_ret; |
62755e35 JA |
3004 | int ret = 0; |
3005 | ||
62755e35 JA |
3006 | cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr); |
3007 | switch (cancel_ret) { | |
3008 | case IO_WQ_CANCEL_OK: | |
3009 | ret = 0; | |
3010 | break; | |
3011 | case IO_WQ_CANCEL_RUNNING: | |
3012 | ret = -EALREADY; | |
3013 | break; | |
3014 | case IO_WQ_CANCEL_NOTFOUND: | |
3015 | ret = -ENOENT; | |
3016 | break; | |
3017 | } | |
3018 | ||
e977d6d3 JA |
3019 | return ret; |
3020 | } | |
3021 | ||
47f46768 JA |
3022 | static void io_async_find_and_cancel(struct io_ring_ctx *ctx, |
3023 | struct io_kiocb *req, __u64 sqe_addr, | |
b0dd8a41 | 3024 | struct io_kiocb **nxt, int success_ret) |
47f46768 JA |
3025 | { |
3026 | unsigned long flags; | |
3027 | int ret; | |
3028 | ||
3029 | ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr); | |
3030 | if (ret != -ENOENT) { | |
3031 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
3032 | goto done; | |
3033 | } | |
3034 | ||
3035 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
3036 | ret = io_timeout_cancel(ctx, sqe_addr); | |
3037 | if (ret != -ENOENT) | |
3038 | goto done; | |
3039 | ret = io_poll_cancel(ctx, sqe_addr); | |
3040 | done: | |
b0dd8a41 JA |
3041 | if (!ret) |
3042 | ret = success_ret; | |
47f46768 JA |
3043 | io_cqring_fill_event(req, ret); |
3044 | io_commit_cqring(ctx); | |
3045 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
3046 | io_cqring_ev_posted(ctx); | |
3047 | ||
4e88d6e7 JA |
3048 | if (ret < 0) |
3049 | req_set_fail_links(req); | |
47f46768 JA |
3050 | io_put_req_find_next(req, nxt); |
3051 | } | |
3052 | ||
3529d8c2 JA |
3053 | static int io_async_cancel_prep(struct io_kiocb *req, |
3054 | const struct io_uring_sqe *sqe) | |
e977d6d3 | 3055 | { |
fbf23849 | 3056 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) |
e977d6d3 JA |
3057 | return -EINVAL; |
3058 | if (sqe->flags || sqe->ioprio || sqe->off || sqe->len || | |
3059 | sqe->cancel_flags) | |
3060 | return -EINVAL; | |
3061 | ||
fbf23849 JA |
3062 | req->cancel.addr = READ_ONCE(sqe->addr); |
3063 | return 0; | |
3064 | } | |
3065 | ||
3066 | static int io_async_cancel(struct io_kiocb *req, struct io_kiocb **nxt) | |
3067 | { | |
3068 | struct io_ring_ctx *ctx = req->ctx; | |
fbf23849 JA |
3069 | |
3070 | io_async_find_and_cancel(ctx, req, req->cancel.addr, nxt, 0); | |
5262f567 JA |
3071 | return 0; |
3072 | } | |
3073 | ||
3529d8c2 JA |
3074 | static int io_req_defer_prep(struct io_kiocb *req, |
3075 | const struct io_uring_sqe *sqe) | |
f67676d1 | 3076 | { |
e781573e | 3077 | ssize_t ret = 0; |
f67676d1 | 3078 | |
d625c6ee | 3079 | switch (req->opcode) { |
e781573e JA |
3080 | case IORING_OP_NOP: |
3081 | break; | |
f67676d1 JA |
3082 | case IORING_OP_READV: |
3083 | case IORING_OP_READ_FIXED: | |
3529d8c2 | 3084 | ret = io_read_prep(req, sqe, true); |
f67676d1 JA |
3085 | break; |
3086 | case IORING_OP_WRITEV: | |
3087 | case IORING_OP_WRITE_FIXED: | |
3529d8c2 | 3088 | ret = io_write_prep(req, sqe, true); |
f67676d1 | 3089 | break; |
0969e783 | 3090 | case IORING_OP_POLL_ADD: |
3529d8c2 | 3091 | ret = io_poll_add_prep(req, sqe); |
0969e783 JA |
3092 | break; |
3093 | case IORING_OP_POLL_REMOVE: | |
3529d8c2 | 3094 | ret = io_poll_remove_prep(req, sqe); |
0969e783 | 3095 | break; |
8ed8d3c3 | 3096 | case IORING_OP_FSYNC: |
3529d8c2 | 3097 | ret = io_prep_fsync(req, sqe); |
8ed8d3c3 JA |
3098 | break; |
3099 | case IORING_OP_SYNC_FILE_RANGE: | |
3529d8c2 | 3100 | ret = io_prep_sfr(req, sqe); |
8ed8d3c3 | 3101 | break; |
03b1230c | 3102 | case IORING_OP_SENDMSG: |
3529d8c2 | 3103 | ret = io_sendmsg_prep(req, sqe); |
03b1230c JA |
3104 | break; |
3105 | case IORING_OP_RECVMSG: | |
3529d8c2 | 3106 | ret = io_recvmsg_prep(req, sqe); |
03b1230c | 3107 | break; |
f499a021 | 3108 | case IORING_OP_CONNECT: |
3529d8c2 | 3109 | ret = io_connect_prep(req, sqe); |
f499a021 | 3110 | break; |
2d28390a | 3111 | case IORING_OP_TIMEOUT: |
3529d8c2 | 3112 | ret = io_timeout_prep(req, sqe, false); |
b7bb4f7d | 3113 | break; |
b29472ee | 3114 | case IORING_OP_TIMEOUT_REMOVE: |
3529d8c2 | 3115 | ret = io_timeout_remove_prep(req, sqe); |
b29472ee | 3116 | break; |
fbf23849 | 3117 | case IORING_OP_ASYNC_CANCEL: |
3529d8c2 | 3118 | ret = io_async_cancel_prep(req, sqe); |
fbf23849 | 3119 | break; |
2d28390a | 3120 | case IORING_OP_LINK_TIMEOUT: |
3529d8c2 | 3121 | ret = io_timeout_prep(req, sqe, true); |
b7bb4f7d | 3122 | break; |
8ed8d3c3 | 3123 | case IORING_OP_ACCEPT: |
3529d8c2 | 3124 | ret = io_accept_prep(req, sqe); |
8ed8d3c3 | 3125 | break; |
f67676d1 | 3126 | default: |
e781573e JA |
3127 | printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n", |
3128 | req->opcode); | |
3129 | ret = -EINVAL; | |
b7bb4f7d | 3130 | break; |
f67676d1 JA |
3131 | } |
3132 | ||
b7bb4f7d | 3133 | return ret; |
f67676d1 JA |
3134 | } |
3135 | ||
3529d8c2 | 3136 | static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
de0617e4 | 3137 | { |
a197f664 | 3138 | struct io_ring_ctx *ctx = req->ctx; |
f67676d1 | 3139 | int ret; |
de0617e4 | 3140 | |
9d858b21 BL |
3141 | /* Still need defer if there is pending req in defer list. */ |
3142 | if (!req_need_defer(req) && list_empty(&ctx->defer_list)) | |
de0617e4 JA |
3143 | return 0; |
3144 | ||
3529d8c2 | 3145 | if (!req->io && io_alloc_async_ctx(req)) |
de0617e4 JA |
3146 | return -EAGAIN; |
3147 | ||
3529d8c2 | 3148 | ret = io_req_defer_prep(req, sqe); |
b7bb4f7d | 3149 | if (ret < 0) |
2d28390a | 3150 | return ret; |
2d28390a | 3151 | |
de0617e4 | 3152 | spin_lock_irq(&ctx->completion_lock); |
9d858b21 | 3153 | if (!req_need_defer(req) && list_empty(&ctx->defer_list)) { |
de0617e4 | 3154 | spin_unlock_irq(&ctx->completion_lock); |
de0617e4 JA |
3155 | return 0; |
3156 | } | |
3157 | ||
915967f6 | 3158 | trace_io_uring_defer(ctx, req, req->user_data); |
de0617e4 JA |
3159 | list_add_tail(&req->list, &ctx->defer_list); |
3160 | spin_unlock_irq(&ctx->completion_lock); | |
3161 | return -EIOCBQUEUED; | |
3162 | } | |
3163 | ||
3529d8c2 JA |
3164 | static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
3165 | struct io_kiocb **nxt, bool force_nonblock) | |
2b188cc1 | 3166 | { |
a197f664 | 3167 | struct io_ring_ctx *ctx = req->ctx; |
d625c6ee | 3168 | int ret; |
2b188cc1 | 3169 | |
d625c6ee | 3170 | switch (req->opcode) { |
2b188cc1 | 3171 | case IORING_OP_NOP: |
78e19bbe | 3172 | ret = io_nop(req); |
2b188cc1 JA |
3173 | break; |
3174 | case IORING_OP_READV: | |
edafccee | 3175 | case IORING_OP_READ_FIXED: |
3529d8c2 JA |
3176 | if (sqe) { |
3177 | ret = io_read_prep(req, sqe, force_nonblock); | |
3178 | if (ret < 0) | |
3179 | break; | |
3180 | } | |
267bc904 | 3181 | ret = io_read(req, nxt, force_nonblock); |
edafccee | 3182 | break; |
3529d8c2 | 3183 | case IORING_OP_WRITEV: |
edafccee | 3184 | case IORING_OP_WRITE_FIXED: |
3529d8c2 JA |
3185 | if (sqe) { |
3186 | ret = io_write_prep(req, sqe, force_nonblock); | |
3187 | if (ret < 0) | |
3188 | break; | |
3189 | } | |
267bc904 | 3190 | ret = io_write(req, nxt, force_nonblock); |
2b188cc1 | 3191 | break; |
c992fe29 | 3192 | case IORING_OP_FSYNC: |
3529d8c2 JA |
3193 | if (sqe) { |
3194 | ret = io_prep_fsync(req, sqe); | |
3195 | if (ret < 0) | |
3196 | break; | |
3197 | } | |
fc4df999 | 3198 | ret = io_fsync(req, nxt, force_nonblock); |
c992fe29 | 3199 | break; |
221c5eb2 | 3200 | case IORING_OP_POLL_ADD: |
3529d8c2 JA |
3201 | if (sqe) { |
3202 | ret = io_poll_add_prep(req, sqe); | |
3203 | if (ret) | |
3204 | break; | |
3205 | } | |
fc4df999 | 3206 | ret = io_poll_add(req, nxt); |
221c5eb2 JA |
3207 | break; |
3208 | case IORING_OP_POLL_REMOVE: | |
3529d8c2 JA |
3209 | if (sqe) { |
3210 | ret = io_poll_remove_prep(req, sqe); | |
3211 | if (ret < 0) | |
3212 | break; | |
3213 | } | |
fc4df999 | 3214 | ret = io_poll_remove(req); |
221c5eb2 | 3215 | break; |
5d17b4a4 | 3216 | case IORING_OP_SYNC_FILE_RANGE: |
3529d8c2 JA |
3217 | if (sqe) { |
3218 | ret = io_prep_sfr(req, sqe); | |
3219 | if (ret < 0) | |
3220 | break; | |
3221 | } | |
fc4df999 | 3222 | ret = io_sync_file_range(req, nxt, force_nonblock); |
5d17b4a4 | 3223 | break; |
0fa03c62 | 3224 | case IORING_OP_SENDMSG: |
3529d8c2 JA |
3225 | if (sqe) { |
3226 | ret = io_sendmsg_prep(req, sqe); | |
3227 | if (ret < 0) | |
3228 | break; | |
3229 | } | |
fc4df999 | 3230 | ret = io_sendmsg(req, nxt, force_nonblock); |
0fa03c62 | 3231 | break; |
aa1fa28f | 3232 | case IORING_OP_RECVMSG: |
3529d8c2 JA |
3233 | if (sqe) { |
3234 | ret = io_recvmsg_prep(req, sqe); | |
3235 | if (ret) | |
3236 | break; | |
3237 | } | |
fc4df999 | 3238 | ret = io_recvmsg(req, nxt, force_nonblock); |
aa1fa28f | 3239 | break; |
5262f567 | 3240 | case IORING_OP_TIMEOUT: |
3529d8c2 JA |
3241 | if (sqe) { |
3242 | ret = io_timeout_prep(req, sqe, false); | |
3243 | if (ret) | |
3244 | break; | |
3245 | } | |
fc4df999 | 3246 | ret = io_timeout(req); |
5262f567 | 3247 | break; |
11365043 | 3248 | case IORING_OP_TIMEOUT_REMOVE: |
3529d8c2 JA |
3249 | if (sqe) { |
3250 | ret = io_timeout_remove_prep(req, sqe); | |
3251 | if (ret) | |
3252 | break; | |
3253 | } | |
fc4df999 | 3254 | ret = io_timeout_remove(req); |
11365043 | 3255 | break; |
17f2fe35 | 3256 | case IORING_OP_ACCEPT: |
3529d8c2 JA |
3257 | if (sqe) { |
3258 | ret = io_accept_prep(req, sqe); | |
3259 | if (ret) | |
3260 | break; | |
3261 | } | |
fc4df999 | 3262 | ret = io_accept(req, nxt, force_nonblock); |
17f2fe35 | 3263 | break; |
f8e85cf2 | 3264 | case IORING_OP_CONNECT: |
3529d8c2 JA |
3265 | if (sqe) { |
3266 | ret = io_connect_prep(req, sqe); | |
3267 | if (ret) | |
3268 | break; | |
3269 | } | |
fc4df999 | 3270 | ret = io_connect(req, nxt, force_nonblock); |
f8e85cf2 | 3271 | break; |
62755e35 | 3272 | case IORING_OP_ASYNC_CANCEL: |
3529d8c2 JA |
3273 | if (sqe) { |
3274 | ret = io_async_cancel_prep(req, sqe); | |
3275 | if (ret) | |
3276 | break; | |
3277 | } | |
fc4df999 | 3278 | ret = io_async_cancel(req, nxt); |
62755e35 | 3279 | break; |
2b188cc1 JA |
3280 | default: |
3281 | ret = -EINVAL; | |
3282 | break; | |
3283 | } | |
3284 | ||
def596e9 JA |
3285 | if (ret) |
3286 | return ret; | |
3287 | ||
3288 | if (ctx->flags & IORING_SETUP_IOPOLL) { | |
11ba820b JA |
3289 | const bool in_async = io_wq_current_is_worker(); |
3290 | ||
9e645e11 | 3291 | if (req->result == -EAGAIN) |
def596e9 JA |
3292 | return -EAGAIN; |
3293 | ||
11ba820b JA |
3294 | /* workqueue context doesn't hold uring_lock, grab it now */ |
3295 | if (in_async) | |
3296 | mutex_lock(&ctx->uring_lock); | |
3297 | ||
def596e9 | 3298 | io_iopoll_req_issued(req); |
11ba820b JA |
3299 | |
3300 | if (in_async) | |
3301 | mutex_unlock(&ctx->uring_lock); | |
def596e9 JA |
3302 | } |
3303 | ||
3304 | return 0; | |
2b188cc1 JA |
3305 | } |
3306 | ||
561fb04a | 3307 | static void io_wq_submit_work(struct io_wq_work **workptr) |
2b188cc1 | 3308 | { |
561fb04a | 3309 | struct io_wq_work *work = *workptr; |
2b188cc1 | 3310 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
561fb04a JA |
3311 | struct io_kiocb *nxt = NULL; |
3312 | int ret = 0; | |
2b188cc1 | 3313 | |
561fb04a JA |
3314 | if (work->flags & IO_WQ_WORK_CANCEL) |
3315 | ret = -ECANCELED; | |
31b51510 | 3316 | |
561fb04a | 3317 | if (!ret) { |
cf6fd4bd PB |
3318 | req->has_user = (work->flags & IO_WQ_WORK_HAS_MM) != 0; |
3319 | req->in_async = true; | |
561fb04a | 3320 | do { |
3529d8c2 | 3321 | ret = io_issue_sqe(req, NULL, &nxt, false); |
561fb04a JA |
3322 | /* |
3323 | * We can get EAGAIN for polled IO even though we're | |
3324 | * forcing a sync submission from here, since we can't | |
3325 | * wait for request slots on the block side. | |
3326 | */ | |
3327 | if (ret != -EAGAIN) | |
3328 | break; | |
3329 | cond_resched(); | |
3330 | } while (1); | |
3331 | } | |
31b51510 | 3332 | |
561fb04a | 3333 | /* drop submission reference */ |
ec9c02ad | 3334 | io_put_req(req); |
817869d2 | 3335 | |
561fb04a | 3336 | if (ret) { |
4e88d6e7 | 3337 | req_set_fail_links(req); |
78e19bbe | 3338 | io_cqring_add_event(req, ret); |
817869d2 | 3339 | io_put_req(req); |
edafccee | 3340 | } |
2b188cc1 | 3341 | |
561fb04a | 3342 | /* if a dependent link is ready, pass it back */ |
78912934 JA |
3343 | if (!ret && nxt) |
3344 | io_wq_assign_next(workptr, nxt); | |
2b188cc1 JA |
3345 | } |
3346 | ||
9e3aa61a JA |
3347 | static bool io_req_op_valid(int op) |
3348 | { | |
3349 | return op >= IORING_OP_NOP && op < IORING_OP_LAST; | |
3350 | } | |
3351 | ||
d625c6ee | 3352 | static int io_req_needs_file(struct io_kiocb *req) |
09bb8394 | 3353 | { |
d625c6ee | 3354 | switch (req->opcode) { |
09bb8394 JA |
3355 | case IORING_OP_NOP: |
3356 | case IORING_OP_POLL_REMOVE: | |
5683e540 | 3357 | case IORING_OP_TIMEOUT: |
a320e9fa PB |
3358 | case IORING_OP_TIMEOUT_REMOVE: |
3359 | case IORING_OP_ASYNC_CANCEL: | |
3360 | case IORING_OP_LINK_TIMEOUT: | |
9e3aa61a | 3361 | return 0; |
09bb8394 | 3362 | default: |
d625c6ee | 3363 | if (io_req_op_valid(req->opcode)) |
9e3aa61a JA |
3364 | return 1; |
3365 | return -EINVAL; | |
09bb8394 JA |
3366 | } |
3367 | } | |
3368 | ||
65e19f54 JA |
3369 | static inline struct file *io_file_from_index(struct io_ring_ctx *ctx, |
3370 | int index) | |
3371 | { | |
3372 | struct fixed_file_table *table; | |
3373 | ||
3374 | table = &ctx->file_table[index >> IORING_FILE_TABLE_SHIFT]; | |
3375 | return table->files[index & IORING_FILE_TABLE_MASK]; | |
3376 | } | |
3377 | ||
3529d8c2 JA |
3378 | static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req, |
3379 | const struct io_uring_sqe *sqe) | |
09bb8394 | 3380 | { |
a197f664 | 3381 | struct io_ring_ctx *ctx = req->ctx; |
09bb8394 | 3382 | unsigned flags; |
9e3aa61a | 3383 | int fd, ret; |
09bb8394 | 3384 | |
3529d8c2 JA |
3385 | flags = READ_ONCE(sqe->flags); |
3386 | fd = READ_ONCE(sqe->fd); | |
09bb8394 | 3387 | |
4fe2c963 | 3388 | if (flags & IOSQE_IO_DRAIN) |
de0617e4 | 3389 | req->flags |= REQ_F_IO_DRAIN; |
de0617e4 | 3390 | |
d625c6ee | 3391 | ret = io_req_needs_file(req); |
9e3aa61a JA |
3392 | if (ret <= 0) |
3393 | return ret; | |
09bb8394 JA |
3394 | |
3395 | if (flags & IOSQE_FIXED_FILE) { | |
65e19f54 | 3396 | if (unlikely(!ctx->file_table || |
09bb8394 JA |
3397 | (unsigned) fd >= ctx->nr_user_files)) |
3398 | return -EBADF; | |
b7620121 | 3399 | fd = array_index_nospec(fd, ctx->nr_user_files); |
65e19f54 JA |
3400 | req->file = io_file_from_index(ctx, fd); |
3401 | if (!req->file) | |
08a45173 | 3402 | return -EBADF; |
09bb8394 JA |
3403 | req->flags |= REQ_F_FIXED_FILE; |
3404 | } else { | |
cf6fd4bd | 3405 | if (req->needs_fixed_file) |
09bb8394 | 3406 | return -EBADF; |
c826bd7a | 3407 | trace_io_uring_file_get(ctx, fd); |
09bb8394 JA |
3408 | req->file = io_file_get(state, fd); |
3409 | if (unlikely(!req->file)) | |
3410 | return -EBADF; | |
3411 | } | |
3412 | ||
3413 | return 0; | |
3414 | } | |
3415 | ||
a197f664 | 3416 | static int io_grab_files(struct io_kiocb *req) |
fcb323cc JA |
3417 | { |
3418 | int ret = -EBADF; | |
a197f664 | 3419 | struct io_ring_ctx *ctx = req->ctx; |
fcb323cc JA |
3420 | |
3421 | rcu_read_lock(); | |
3422 | spin_lock_irq(&ctx->inflight_lock); | |
3423 | /* | |
3424 | * We use the f_ops->flush() handler to ensure that we can flush | |
3425 | * out work accessing these files if the fd is closed. Check if | |
3426 | * the fd has changed since we started down this path, and disallow | |
3427 | * this operation if it has. | |
3428 | */ | |
cf6fd4bd | 3429 | if (fcheck(req->ring_fd) == req->ring_file) { |
fcb323cc JA |
3430 | list_add(&req->inflight_entry, &ctx->inflight_list); |
3431 | req->flags |= REQ_F_INFLIGHT; | |
3432 | req->work.files = current->files; | |
3433 | ret = 0; | |
3434 | } | |
3435 | spin_unlock_irq(&ctx->inflight_lock); | |
3436 | rcu_read_unlock(); | |
3437 | ||
3438 | return ret; | |
3439 | } | |
3440 | ||
2665abfd | 3441 | static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer) |
2b188cc1 | 3442 | { |
ad8a48ac JA |
3443 | struct io_timeout_data *data = container_of(timer, |
3444 | struct io_timeout_data, timer); | |
3445 | struct io_kiocb *req = data->req; | |
2665abfd JA |
3446 | struct io_ring_ctx *ctx = req->ctx; |
3447 | struct io_kiocb *prev = NULL; | |
3448 | unsigned long flags; | |
2665abfd JA |
3449 | |
3450 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
3451 | ||
3452 | /* | |
3453 | * We don't expect the list to be empty, that will only happen if we | |
3454 | * race with the completion of the linked work. | |
3455 | */ | |
4493233e PB |
3456 | if (!list_empty(&req->link_list)) { |
3457 | prev = list_entry(req->link_list.prev, struct io_kiocb, | |
3458 | link_list); | |
5d960724 | 3459 | if (refcount_inc_not_zero(&prev->refs)) { |
4493233e | 3460 | list_del_init(&req->link_list); |
5d960724 JA |
3461 | prev->flags &= ~REQ_F_LINK_TIMEOUT; |
3462 | } else | |
76a46e06 | 3463 | prev = NULL; |
2665abfd JA |
3464 | } |
3465 | ||
3466 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
3467 | ||
3468 | if (prev) { | |
4e88d6e7 | 3469 | req_set_fail_links(prev); |
b0dd8a41 JA |
3470 | io_async_find_and_cancel(ctx, req, prev->user_data, NULL, |
3471 | -ETIME); | |
76a46e06 | 3472 | io_put_req(prev); |
47f46768 JA |
3473 | } else { |
3474 | io_cqring_add_event(req, -ETIME); | |
3475 | io_put_req(req); | |
2665abfd | 3476 | } |
2665abfd JA |
3477 | return HRTIMER_NORESTART; |
3478 | } | |
3479 | ||
ad8a48ac | 3480 | static void io_queue_linked_timeout(struct io_kiocb *req) |
2665abfd | 3481 | { |
76a46e06 | 3482 | struct io_ring_ctx *ctx = req->ctx; |
2665abfd | 3483 | |
76a46e06 JA |
3484 | /* |
3485 | * If the list is now empty, then our linked request finished before | |
3486 | * we got a chance to setup the timer | |
3487 | */ | |
3488 | spin_lock_irq(&ctx->completion_lock); | |
4493233e | 3489 | if (!list_empty(&req->link_list)) { |
2d28390a | 3490 | struct io_timeout_data *data = &req->io->timeout; |
94ae5e77 | 3491 | |
ad8a48ac JA |
3492 | data->timer.function = io_link_timeout_fn; |
3493 | hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), | |
3494 | data->mode); | |
2665abfd | 3495 | } |
76a46e06 | 3496 | spin_unlock_irq(&ctx->completion_lock); |
2665abfd | 3497 | |
2665abfd | 3498 | /* drop submission reference */ |
76a46e06 JA |
3499 | io_put_req(req); |
3500 | } | |
2665abfd | 3501 | |
ad8a48ac | 3502 | static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) |
2665abfd JA |
3503 | { |
3504 | struct io_kiocb *nxt; | |
3505 | ||
3506 | if (!(req->flags & REQ_F_LINK)) | |
3507 | return NULL; | |
3508 | ||
4493233e PB |
3509 | nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, |
3510 | link_list); | |
d625c6ee | 3511 | if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT) |
76a46e06 | 3512 | return NULL; |
2665abfd | 3513 | |
76a46e06 | 3514 | req->flags |= REQ_F_LINK_TIMEOUT; |
76a46e06 | 3515 | return nxt; |
2665abfd JA |
3516 | } |
3517 | ||
3529d8c2 | 3518 | static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
2b188cc1 | 3519 | { |
4a0a7a18 | 3520 | struct io_kiocb *linked_timeout; |
f9bd67f6 | 3521 | struct io_kiocb *nxt = NULL; |
e0c5c576 | 3522 | int ret; |
2b188cc1 | 3523 | |
4a0a7a18 JA |
3524 | again: |
3525 | linked_timeout = io_prep_linked_timeout(req); | |
3526 | ||
3529d8c2 | 3527 | ret = io_issue_sqe(req, sqe, &nxt, true); |
491381ce JA |
3528 | |
3529 | /* | |
3530 | * We async punt it if the file wasn't marked NOWAIT, or if the file | |
3531 | * doesn't support non-blocking read/write attempts | |
3532 | */ | |
3533 | if (ret == -EAGAIN && (!(req->flags & REQ_F_NOWAIT) || | |
3534 | (req->flags & REQ_F_MUST_PUNT))) { | |
bbad27b2 PB |
3535 | if (req->work.flags & IO_WQ_WORK_NEEDS_FILES) { |
3536 | ret = io_grab_files(req); | |
3537 | if (ret) | |
3538 | goto err; | |
2b188cc1 | 3539 | } |
bbad27b2 PB |
3540 | |
3541 | /* | |
3542 | * Queued up for async execution, worker will release | |
3543 | * submit reference when the iocb is actually submitted. | |
3544 | */ | |
3545 | io_queue_async_work(req); | |
4a0a7a18 | 3546 | goto done_req; |
2b188cc1 | 3547 | } |
e65ef56d | 3548 | |
fcb323cc | 3549 | err: |
76a46e06 | 3550 | /* drop submission reference */ |
ec9c02ad | 3551 | io_put_req(req); |
e65ef56d | 3552 | |
f9bd67f6 | 3553 | if (linked_timeout) { |
76a46e06 | 3554 | if (!ret) |
f9bd67f6 | 3555 | io_queue_linked_timeout(linked_timeout); |
76a46e06 | 3556 | else |
f9bd67f6 | 3557 | io_put_req(linked_timeout); |
76a46e06 JA |
3558 | } |
3559 | ||
e65ef56d | 3560 | /* and drop final reference, if we failed */ |
9e645e11 | 3561 | if (ret) { |
78e19bbe | 3562 | io_cqring_add_event(req, ret); |
4e88d6e7 | 3563 | req_set_fail_links(req); |
e65ef56d | 3564 | io_put_req(req); |
9e645e11 | 3565 | } |
4a0a7a18 JA |
3566 | done_req: |
3567 | if (nxt) { | |
3568 | req = nxt; | |
3569 | nxt = NULL; | |
3570 | goto again; | |
3571 | } | |
2b188cc1 JA |
3572 | } |
3573 | ||
3529d8c2 | 3574 | static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
4fe2c963 JL |
3575 | { |
3576 | int ret; | |
3577 | ||
1b4a51b6 PB |
3578 | if (unlikely(req->ctx->drain_next)) { |
3579 | req->flags |= REQ_F_IO_DRAIN; | |
3580 | req->ctx->drain_next = false; | |
3581 | } | |
3582 | req->ctx->drain_next = (req->flags & REQ_F_DRAIN_LINK); | |
3583 | ||
3529d8c2 | 3584 | ret = io_req_defer(req, sqe); |
4fe2c963 JL |
3585 | if (ret) { |
3586 | if (ret != -EIOCBQUEUED) { | |
78e19bbe | 3587 | io_cqring_add_event(req, ret); |
4e88d6e7 | 3588 | req_set_fail_links(req); |
78e19bbe | 3589 | io_double_put_req(req); |
4fe2c963 | 3590 | } |
0e0702da | 3591 | } else |
3529d8c2 | 3592 | __io_queue_sqe(req, sqe); |
4fe2c963 JL |
3593 | } |
3594 | ||
1b4a51b6 | 3595 | static inline void io_queue_link_head(struct io_kiocb *req) |
4fe2c963 | 3596 | { |
94ae5e77 | 3597 | if (unlikely(req->flags & REQ_F_FAIL_LINK)) { |
1b4a51b6 PB |
3598 | io_cqring_add_event(req, -ECANCELED); |
3599 | io_double_put_req(req); | |
3600 | } else | |
3529d8c2 | 3601 | io_queue_sqe(req, NULL); |
4fe2c963 JL |
3602 | } |
3603 | ||
4e88d6e7 JA |
3604 | #define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \ |
3605 | IOSQE_IO_HARDLINK) | |
9e645e11 | 3606 | |
3529d8c2 JA |
3607 | static bool io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
3608 | struct io_submit_state *state, struct io_kiocb **link) | |
9e645e11 | 3609 | { |
a197f664 | 3610 | struct io_ring_ctx *ctx = req->ctx; |
9e645e11 JA |
3611 | int ret; |
3612 | ||
3613 | /* enforce forwards compatibility on users */ | |
3529d8c2 | 3614 | if (unlikely(sqe->flags & ~SQE_VALID_FLAGS)) { |
9e645e11 | 3615 | ret = -EINVAL; |
196be95c | 3616 | goto err_req; |
9e645e11 JA |
3617 | } |
3618 | ||
3529d8c2 | 3619 | ret = io_req_set_file(state, req, sqe); |
9e645e11 JA |
3620 | if (unlikely(ret)) { |
3621 | err_req: | |
78e19bbe JA |
3622 | io_cqring_add_event(req, ret); |
3623 | io_double_put_req(req); | |
2e6e1fde | 3624 | return false; |
9e645e11 JA |
3625 | } |
3626 | ||
9e645e11 JA |
3627 | /* |
3628 | * If we already have a head request, queue this one for async | |
3629 | * submittal once the head completes. If we don't have a head but | |
3630 | * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be | |
3631 | * submitted sync once the chain is complete. If none of those | |
3632 | * conditions are true (normal request), then just queue it. | |
3633 | */ | |
3634 | if (*link) { | |
3635 | struct io_kiocb *prev = *link; | |
3636 | ||
3529d8c2 | 3637 | if (sqe->flags & IOSQE_IO_DRAIN) |
1b4a51b6 PB |
3638 | (*link)->flags |= REQ_F_DRAIN_LINK | REQ_F_IO_DRAIN; |
3639 | ||
3529d8c2 | 3640 | if (sqe->flags & IOSQE_IO_HARDLINK) |
4e88d6e7 JA |
3641 | req->flags |= REQ_F_HARDLINK; |
3642 | ||
b7bb4f7d | 3643 | if (io_alloc_async_ctx(req)) { |
9e645e11 JA |
3644 | ret = -EAGAIN; |
3645 | goto err_req; | |
3646 | } | |
3647 | ||
3529d8c2 | 3648 | ret = io_req_defer_prep(req, sqe); |
2d28390a | 3649 | if (ret) { |
4e88d6e7 | 3650 | /* fail even hard links since we don't submit */ |
2d28390a | 3651 | prev->flags |= REQ_F_FAIL_LINK; |
f67676d1 | 3652 | goto err_req; |
2d28390a | 3653 | } |
c826bd7a | 3654 | trace_io_uring_link(ctx, req, prev); |
4493233e | 3655 | list_add_tail(&req->link_list, &prev->link_list); |
3529d8c2 | 3656 | } else if (sqe->flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK)) { |
9e645e11 | 3657 | req->flags |= REQ_F_LINK; |
3529d8c2 | 3658 | if (sqe->flags & IOSQE_IO_HARDLINK) |
4e88d6e7 | 3659 | req->flags |= REQ_F_HARDLINK; |
9e645e11 | 3660 | |
9e645e11 | 3661 | INIT_LIST_HEAD(&req->link_list); |
3529d8c2 JA |
3662 | ret = io_req_defer_prep(req, sqe); |
3663 | if (ret) | |
3664 | req->flags |= REQ_F_FAIL_LINK; | |
9e645e11 JA |
3665 | *link = req; |
3666 | } else { | |
3529d8c2 | 3667 | io_queue_sqe(req, sqe); |
9e645e11 | 3668 | } |
2e6e1fde PB |
3669 | |
3670 | return true; | |
9e645e11 JA |
3671 | } |
3672 | ||
9a56a232 JA |
3673 | /* |
3674 | * Batched submission is done, ensure local IO is flushed out. | |
3675 | */ | |
3676 | static void io_submit_state_end(struct io_submit_state *state) | |
3677 | { | |
3678 | blk_finish_plug(&state->plug); | |
3d6770fb | 3679 | io_file_put(state); |
2579f913 JA |
3680 | if (state->free_reqs) |
3681 | kmem_cache_free_bulk(req_cachep, state->free_reqs, | |
3682 | &state->reqs[state->cur_req]); | |
9a56a232 JA |
3683 | } |
3684 | ||
3685 | /* | |
3686 | * Start submission side cache. | |
3687 | */ | |
3688 | static void io_submit_state_start(struct io_submit_state *state, | |
22efde59 | 3689 | unsigned int max_ios) |
9a56a232 JA |
3690 | { |
3691 | blk_start_plug(&state->plug); | |
2579f913 | 3692 | state->free_reqs = 0; |
9a56a232 JA |
3693 | state->file = NULL; |
3694 | state->ios_left = max_ios; | |
3695 | } | |
3696 | ||
2b188cc1 JA |
3697 | static void io_commit_sqring(struct io_ring_ctx *ctx) |
3698 | { | |
75b28aff | 3699 | struct io_rings *rings = ctx->rings; |
2b188cc1 | 3700 | |
75b28aff | 3701 | if (ctx->cached_sq_head != READ_ONCE(rings->sq.head)) { |
2b188cc1 JA |
3702 | /* |
3703 | * Ensure any loads from the SQEs are done at this point, | |
3704 | * since once we write the new head, the application could | |
3705 | * write new data to them. | |
3706 | */ | |
75b28aff | 3707 | smp_store_release(&rings->sq.head, ctx->cached_sq_head); |
2b188cc1 JA |
3708 | } |
3709 | } | |
3710 | ||
2b188cc1 | 3711 | /* |
3529d8c2 | 3712 | * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory |
2b188cc1 JA |
3713 | * that is mapped by userspace. This means that care needs to be taken to |
3714 | * ensure that reads are stable, as we cannot rely on userspace always | |
3715 | * being a good citizen. If members of the sqe are validated and then later | |
3716 | * used, it's important that those reads are done through READ_ONCE() to | |
3717 | * prevent a re-load down the line. | |
3718 | */ | |
3529d8c2 JA |
3719 | static bool io_get_sqring(struct io_ring_ctx *ctx, struct io_kiocb *req, |
3720 | const struct io_uring_sqe **sqe_ptr) | |
2b188cc1 | 3721 | { |
75b28aff HV |
3722 | struct io_rings *rings = ctx->rings; |
3723 | u32 *sq_array = ctx->sq_array; | |
2b188cc1 JA |
3724 | unsigned head; |
3725 | ||
3726 | /* | |
3727 | * The cached sq head (or cq tail) serves two purposes: | |
3728 | * | |
3729 | * 1) allows us to batch the cost of updating the user visible | |
3730 | * head updates. | |
3731 | * 2) allows the kernel side to track the head on its own, even | |
3732 | * though the application is the one updating it. | |
3733 | */ | |
3734 | head = ctx->cached_sq_head; | |
e523a29c | 3735 | /* make sure SQ entry isn't read before tail */ |
9835d6fa | 3736 | if (unlikely(head == smp_load_acquire(&rings->sq.tail))) |
2b188cc1 JA |
3737 | return false; |
3738 | ||
75b28aff | 3739 | head = READ_ONCE(sq_array[head & ctx->sq_mask]); |
9835d6fa | 3740 | if (likely(head < ctx->sq_entries)) { |
cf6fd4bd PB |
3741 | /* |
3742 | * All io need record the previous position, if LINK vs DARIN, | |
3743 | * it can be used to mark the position of the first IO in the | |
3744 | * link list. | |
3745 | */ | |
3746 | req->sequence = ctx->cached_sq_head; | |
3529d8c2 JA |
3747 | *sqe_ptr = &ctx->sq_sqes[head]; |
3748 | req->opcode = READ_ONCE((*sqe_ptr)->opcode); | |
3749 | req->user_data = READ_ONCE((*sqe_ptr)->user_data); | |
2b188cc1 JA |
3750 | ctx->cached_sq_head++; |
3751 | return true; | |
3752 | } | |
3753 | ||
3754 | /* drop invalid entries */ | |
3755 | ctx->cached_sq_head++; | |
498ccd9e JA |
3756 | ctx->cached_sq_dropped++; |
3757 | WRITE_ONCE(rings->sq_dropped, ctx->cached_sq_dropped); | |
2b188cc1 JA |
3758 | return false; |
3759 | } | |
3760 | ||
fb5ccc98 | 3761 | static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr, |
ae9428ca PB |
3762 | struct file *ring_file, int ring_fd, |
3763 | struct mm_struct **mm, bool async) | |
6c271ce2 JA |
3764 | { |
3765 | struct io_submit_state state, *statep = NULL; | |
9e645e11 | 3766 | struct io_kiocb *link = NULL; |
9e645e11 | 3767 | int i, submitted = 0; |
95a1b3ff | 3768 | bool mm_fault = false; |
6c271ce2 | 3769 | |
c4a2ed72 JA |
3770 | /* if we have a backlog and couldn't flush it all, return BUSY */ |
3771 | if (!list_empty(&ctx->cq_overflow_list) && | |
3772 | !io_cqring_overflow_flush(ctx, false)) | |
1d7bb1d5 | 3773 | return -EBUSY; |
6c271ce2 JA |
3774 | |
3775 | if (nr > IO_PLUG_THRESHOLD) { | |
22efde59 | 3776 | io_submit_state_start(&state, nr); |
6c271ce2 JA |
3777 | statep = &state; |
3778 | } | |
3779 | ||
3780 | for (i = 0; i < nr; i++) { | |
3529d8c2 | 3781 | const struct io_uring_sqe *sqe; |
196be95c | 3782 | struct io_kiocb *req; |
50585b9a | 3783 | unsigned int sqe_flags; |
fb5ccc98 | 3784 | |
196be95c PB |
3785 | req = io_get_req(ctx, statep); |
3786 | if (unlikely(!req)) { | |
3787 | if (!submitted) | |
3788 | submitted = -EAGAIN; | |
fb5ccc98 | 3789 | break; |
196be95c | 3790 | } |
3529d8c2 | 3791 | if (!io_get_sqring(ctx, req, &sqe)) { |
196be95c PB |
3792 | __io_free_req(req); |
3793 | break; | |
3794 | } | |
fb5ccc98 | 3795 | |
d625c6ee | 3796 | if (io_req_needs_user(req) && !*mm) { |
95a1b3ff PB |
3797 | mm_fault = mm_fault || !mmget_not_zero(ctx->sqo_mm); |
3798 | if (!mm_fault) { | |
3799 | use_mm(ctx->sqo_mm); | |
3800 | *mm = ctx->sqo_mm; | |
3801 | } | |
9e645e11 | 3802 | } |
9e645e11 | 3803 | |
2e6e1fde | 3804 | submitted++; |
3529d8c2 | 3805 | sqe_flags = sqe->flags; |
50585b9a | 3806 | |
cf6fd4bd PB |
3807 | req->ring_file = ring_file; |
3808 | req->ring_fd = ring_fd; | |
3809 | req->has_user = *mm != NULL; | |
3810 | req->in_async = async; | |
3811 | req->needs_fixed_file = async; | |
d625c6ee | 3812 | trace_io_uring_submit_sqe(ctx, req->user_data, true, async); |
3529d8c2 | 3813 | if (!io_submit_sqe(req, sqe, statep, &link)) |
2e6e1fde | 3814 | break; |
e5eb6366 PB |
3815 | /* |
3816 | * If previous wasn't linked and we have a linked command, | |
3817 | * that's the end of the chain. Submit the previous link. | |
3818 | */ | |
ffbb8d6b | 3819 | if (!(sqe_flags & (IOSQE_IO_LINK|IOSQE_IO_HARDLINK)) && link) { |
1b4a51b6 | 3820 | io_queue_link_head(link); |
e5eb6366 | 3821 | link = NULL; |
6c271ce2 | 3822 | } |
6c271ce2 JA |
3823 | } |
3824 | ||
9e645e11 | 3825 | if (link) |
1b4a51b6 | 3826 | io_queue_link_head(link); |
6c271ce2 JA |
3827 | if (statep) |
3828 | io_submit_state_end(&state); | |
3829 | ||
ae9428ca PB |
3830 | /* Commit SQ ring head once we've consumed and submitted all SQEs */ |
3831 | io_commit_sqring(ctx); | |
3832 | ||
6c271ce2 JA |
3833 | return submitted; |
3834 | } | |
3835 | ||
3836 | static int io_sq_thread(void *data) | |
3837 | { | |
6c271ce2 JA |
3838 | struct io_ring_ctx *ctx = data; |
3839 | struct mm_struct *cur_mm = NULL; | |
181e448d | 3840 | const struct cred *old_cred; |
6c271ce2 JA |
3841 | mm_segment_t old_fs; |
3842 | DEFINE_WAIT(wait); | |
3843 | unsigned inflight; | |
3844 | unsigned long timeout; | |
c1edbf5f | 3845 | int ret; |
6c271ce2 | 3846 | |
206aefde | 3847 | complete(&ctx->completions[1]); |
a4c0b3de | 3848 | |
6c271ce2 JA |
3849 | old_fs = get_fs(); |
3850 | set_fs(USER_DS); | |
181e448d | 3851 | old_cred = override_creds(ctx->creds); |
6c271ce2 | 3852 | |
c1edbf5f | 3853 | ret = timeout = inflight = 0; |
2bbcd6d3 | 3854 | while (!kthread_should_park()) { |
fb5ccc98 | 3855 | unsigned int to_submit; |
6c271ce2 JA |
3856 | |
3857 | if (inflight) { | |
3858 | unsigned nr_events = 0; | |
3859 | ||
3860 | if (ctx->flags & IORING_SETUP_IOPOLL) { | |
2b2ed975 JA |
3861 | /* |
3862 | * inflight is the count of the maximum possible | |
3863 | * entries we submitted, but it can be smaller | |
3864 | * if we dropped some of them. If we don't have | |
3865 | * poll entries available, then we know that we | |
3866 | * have nothing left to poll for. Reset the | |
3867 | * inflight count to zero in that case. | |
3868 | */ | |
3869 | mutex_lock(&ctx->uring_lock); | |
3870 | if (!list_empty(&ctx->poll_list)) | |
3871 | __io_iopoll_check(ctx, &nr_events, 0); | |
3872 | else | |
3873 | inflight = 0; | |
3874 | mutex_unlock(&ctx->uring_lock); | |
6c271ce2 JA |
3875 | } else { |
3876 | /* | |
3877 | * Normal IO, just pretend everything completed. | |
3878 | * We don't have to poll completions for that. | |
3879 | */ | |
3880 | nr_events = inflight; | |
3881 | } | |
3882 | ||
3883 | inflight -= nr_events; | |
3884 | if (!inflight) | |
3885 | timeout = jiffies + ctx->sq_thread_idle; | |
3886 | } | |
3887 | ||
fb5ccc98 | 3888 | to_submit = io_sqring_entries(ctx); |
c1edbf5f JA |
3889 | |
3890 | /* | |
3891 | * If submit got -EBUSY, flag us as needing the application | |
3892 | * to enter the kernel to reap and flush events. | |
3893 | */ | |
3894 | if (!to_submit || ret == -EBUSY) { | |
6c271ce2 JA |
3895 | /* |
3896 | * We're polling. If we're within the defined idle | |
3897 | * period, then let us spin without work before going | |
c1edbf5f JA |
3898 | * to sleep. The exception is if we got EBUSY doing |
3899 | * more IO, we should wait for the application to | |
3900 | * reap events and wake us up. | |
6c271ce2 | 3901 | */ |
c1edbf5f JA |
3902 | if (inflight || |
3903 | (!time_after(jiffies, timeout) && ret != -EBUSY)) { | |
9831a90c | 3904 | cond_resched(); |
6c271ce2 JA |
3905 | continue; |
3906 | } | |
3907 | ||
3908 | /* | |
3909 | * Drop cur_mm before scheduling, we can't hold it for | |
3910 | * long periods (or over schedule()). Do this before | |
3911 | * adding ourselves to the waitqueue, as the unuse/drop | |
3912 | * may sleep. | |
3913 | */ | |
3914 | if (cur_mm) { | |
3915 | unuse_mm(cur_mm); | |
3916 | mmput(cur_mm); | |
3917 | cur_mm = NULL; | |
3918 | } | |
3919 | ||
3920 | prepare_to_wait(&ctx->sqo_wait, &wait, | |
3921 | TASK_INTERRUPTIBLE); | |
3922 | ||
3923 | /* Tell userspace we may need a wakeup call */ | |
75b28aff | 3924 | ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP; |
0d7bae69 SB |
3925 | /* make sure to read SQ tail after writing flags */ |
3926 | smp_mb(); | |
6c271ce2 | 3927 | |
fb5ccc98 | 3928 | to_submit = io_sqring_entries(ctx); |
c1edbf5f | 3929 | if (!to_submit || ret == -EBUSY) { |
2bbcd6d3 | 3930 | if (kthread_should_park()) { |
6c271ce2 JA |
3931 | finish_wait(&ctx->sqo_wait, &wait); |
3932 | break; | |
3933 | } | |
3934 | if (signal_pending(current)) | |
3935 | flush_signals(current); | |
3936 | schedule(); | |
3937 | finish_wait(&ctx->sqo_wait, &wait); | |
3938 | ||
75b28aff | 3939 | ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; |
6c271ce2 JA |
3940 | continue; |
3941 | } | |
3942 | finish_wait(&ctx->sqo_wait, &wait); | |
3943 | ||
75b28aff | 3944 | ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; |
6c271ce2 JA |
3945 | } |
3946 | ||
fb5ccc98 | 3947 | to_submit = min(to_submit, ctx->sq_entries); |
8a4955ff | 3948 | mutex_lock(&ctx->uring_lock); |
1d7bb1d5 | 3949 | ret = io_submit_sqes(ctx, to_submit, NULL, -1, &cur_mm, true); |
8a4955ff | 3950 | mutex_unlock(&ctx->uring_lock); |
1d7bb1d5 JA |
3951 | if (ret > 0) |
3952 | inflight += ret; | |
6c271ce2 JA |
3953 | } |
3954 | ||
3955 | set_fs(old_fs); | |
3956 | if (cur_mm) { | |
3957 | unuse_mm(cur_mm); | |
3958 | mmput(cur_mm); | |
3959 | } | |
181e448d | 3960 | revert_creds(old_cred); |
06058632 | 3961 | |
2bbcd6d3 | 3962 | kthread_parkme(); |
06058632 | 3963 | |
6c271ce2 JA |
3964 | return 0; |
3965 | } | |
3966 | ||
bda52162 JA |
3967 | struct io_wait_queue { |
3968 | struct wait_queue_entry wq; | |
3969 | struct io_ring_ctx *ctx; | |
3970 | unsigned to_wait; | |
3971 | unsigned nr_timeouts; | |
3972 | }; | |
3973 | ||
1d7bb1d5 | 3974 | static inline bool io_should_wake(struct io_wait_queue *iowq, bool noflush) |
bda52162 JA |
3975 | { |
3976 | struct io_ring_ctx *ctx = iowq->ctx; | |
3977 | ||
3978 | /* | |
d195a66e | 3979 | * Wake up if we have enough events, or if a timeout occurred since we |
bda52162 JA |
3980 | * started waiting. For timeouts, we always want to return to userspace, |
3981 | * regardless of event count. | |
3982 | */ | |
1d7bb1d5 | 3983 | return io_cqring_events(ctx, noflush) >= iowq->to_wait || |
bda52162 JA |
3984 | atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; |
3985 | } | |
3986 | ||
3987 | static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode, | |
3988 | int wake_flags, void *key) | |
3989 | { | |
3990 | struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, | |
3991 | wq); | |
3992 | ||
1d7bb1d5 JA |
3993 | /* use noflush == true, as we can't safely rely on locking context */ |
3994 | if (!io_should_wake(iowq, true)) | |
bda52162 JA |
3995 | return -1; |
3996 | ||
3997 | return autoremove_wake_function(curr, mode, wake_flags, key); | |
3998 | } | |
3999 | ||
2b188cc1 JA |
4000 | /* |
4001 | * Wait until events become available, if we don't already have some. The | |
4002 | * application must reap them itself, as they reside on the shared cq ring. | |
4003 | */ | |
4004 | static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, | |
4005 | const sigset_t __user *sig, size_t sigsz) | |
4006 | { | |
bda52162 JA |
4007 | struct io_wait_queue iowq = { |
4008 | .wq = { | |
4009 | .private = current, | |
4010 | .func = io_wake_function, | |
4011 | .entry = LIST_HEAD_INIT(iowq.wq.entry), | |
4012 | }, | |
4013 | .ctx = ctx, | |
4014 | .to_wait = min_events, | |
4015 | }; | |
75b28aff | 4016 | struct io_rings *rings = ctx->rings; |
e9ffa5c2 | 4017 | int ret = 0; |
2b188cc1 | 4018 | |
1d7bb1d5 | 4019 | if (io_cqring_events(ctx, false) >= min_events) |
2b188cc1 JA |
4020 | return 0; |
4021 | ||
4022 | if (sig) { | |
9e75ad5d AB |
4023 | #ifdef CONFIG_COMPAT |
4024 | if (in_compat_syscall()) | |
4025 | ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig, | |
b772434b | 4026 | sigsz); |
9e75ad5d AB |
4027 | else |
4028 | #endif | |
b772434b | 4029 | ret = set_user_sigmask(sig, sigsz); |
9e75ad5d | 4030 | |
2b188cc1 JA |
4031 | if (ret) |
4032 | return ret; | |
4033 | } | |
4034 | ||
bda52162 | 4035 | iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts); |
c826bd7a | 4036 | trace_io_uring_cqring_wait(ctx, min_events); |
bda52162 JA |
4037 | do { |
4038 | prepare_to_wait_exclusive(&ctx->wait, &iowq.wq, | |
4039 | TASK_INTERRUPTIBLE); | |
1d7bb1d5 | 4040 | if (io_should_wake(&iowq, false)) |
bda52162 JA |
4041 | break; |
4042 | schedule(); | |
4043 | if (signal_pending(current)) { | |
e9ffa5c2 | 4044 | ret = -EINTR; |
bda52162 JA |
4045 | break; |
4046 | } | |
4047 | } while (1); | |
4048 | finish_wait(&ctx->wait, &iowq.wq); | |
4049 | ||
e9ffa5c2 | 4050 | restore_saved_sigmask_unless(ret == -EINTR); |
2b188cc1 | 4051 | |
75b28aff | 4052 | return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; |
2b188cc1 JA |
4053 | } |
4054 | ||
6b06314c JA |
4055 | static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) |
4056 | { | |
4057 | #if defined(CONFIG_UNIX) | |
4058 | if (ctx->ring_sock) { | |
4059 | struct sock *sock = ctx->ring_sock->sk; | |
4060 | struct sk_buff *skb; | |
4061 | ||
4062 | while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL) | |
4063 | kfree_skb(skb); | |
4064 | } | |
4065 | #else | |
4066 | int i; | |
4067 | ||
65e19f54 JA |
4068 | for (i = 0; i < ctx->nr_user_files; i++) { |
4069 | struct file *file; | |
4070 | ||
4071 | file = io_file_from_index(ctx, i); | |
4072 | if (file) | |
4073 | fput(file); | |
4074 | } | |
6b06314c JA |
4075 | #endif |
4076 | } | |
4077 | ||
4078 | static int io_sqe_files_unregister(struct io_ring_ctx *ctx) | |
4079 | { | |
65e19f54 JA |
4080 | unsigned nr_tables, i; |
4081 | ||
4082 | if (!ctx->file_table) | |
6b06314c JA |
4083 | return -ENXIO; |
4084 | ||
4085 | __io_sqe_files_unregister(ctx); | |
65e19f54 JA |
4086 | nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE); |
4087 | for (i = 0; i < nr_tables; i++) | |
4088 | kfree(ctx->file_table[i].files); | |
4089 | kfree(ctx->file_table); | |
4090 | ctx->file_table = NULL; | |
6b06314c JA |
4091 | ctx->nr_user_files = 0; |
4092 | return 0; | |
4093 | } | |
4094 | ||
6c271ce2 JA |
4095 | static void io_sq_thread_stop(struct io_ring_ctx *ctx) |
4096 | { | |
4097 | if (ctx->sqo_thread) { | |
206aefde | 4098 | wait_for_completion(&ctx->completions[1]); |
2bbcd6d3 RP |
4099 | /* |
4100 | * The park is a bit of a work-around, without it we get | |
4101 | * warning spews on shutdown with SQPOLL set and affinity | |
4102 | * set to a single CPU. | |
4103 | */ | |
06058632 | 4104 | kthread_park(ctx->sqo_thread); |
6c271ce2 JA |
4105 | kthread_stop(ctx->sqo_thread); |
4106 | ctx->sqo_thread = NULL; | |
4107 | } | |
4108 | } | |
4109 | ||
6b06314c JA |
4110 | static void io_finish_async(struct io_ring_ctx *ctx) |
4111 | { | |
6c271ce2 JA |
4112 | io_sq_thread_stop(ctx); |
4113 | ||
561fb04a JA |
4114 | if (ctx->io_wq) { |
4115 | io_wq_destroy(ctx->io_wq); | |
4116 | ctx->io_wq = NULL; | |
6b06314c JA |
4117 | } |
4118 | } | |
4119 | ||
4120 | #if defined(CONFIG_UNIX) | |
4121 | static void io_destruct_skb(struct sk_buff *skb) | |
4122 | { | |
4123 | struct io_ring_ctx *ctx = skb->sk->sk_user_data; | |
8a997340 | 4124 | |
561fb04a JA |
4125 | if (ctx->io_wq) |
4126 | io_wq_flush(ctx->io_wq); | |
6b06314c | 4127 | |
6b06314c JA |
4128 | unix_destruct_scm(skb); |
4129 | } | |
4130 | ||
4131 | /* | |
4132 | * Ensure the UNIX gc is aware of our file set, so we are certain that | |
4133 | * the io_uring can be safely unregistered on process exit, even if we have | |
4134 | * loops in the file referencing. | |
4135 | */ | |
4136 | static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) | |
4137 | { | |
4138 | struct sock *sk = ctx->ring_sock->sk; | |
4139 | struct scm_fp_list *fpl; | |
4140 | struct sk_buff *skb; | |
08a45173 | 4141 | int i, nr_files; |
6b06314c JA |
4142 | |
4143 | if (!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) { | |
4144 | unsigned long inflight = ctx->user->unix_inflight + nr; | |
4145 | ||
4146 | if (inflight > task_rlimit(current, RLIMIT_NOFILE)) | |
4147 | return -EMFILE; | |
4148 | } | |
4149 | ||
4150 | fpl = kzalloc(sizeof(*fpl), GFP_KERNEL); | |
4151 | if (!fpl) | |
4152 | return -ENOMEM; | |
4153 | ||
4154 | skb = alloc_skb(0, GFP_KERNEL); | |
4155 | if (!skb) { | |
4156 | kfree(fpl); | |
4157 | return -ENOMEM; | |
4158 | } | |
4159 | ||
4160 | skb->sk = sk; | |
6b06314c | 4161 | |
08a45173 | 4162 | nr_files = 0; |
6b06314c JA |
4163 | fpl->user = get_uid(ctx->user); |
4164 | for (i = 0; i < nr; i++) { | |
65e19f54 JA |
4165 | struct file *file = io_file_from_index(ctx, i + offset); |
4166 | ||
4167 | if (!file) | |
08a45173 | 4168 | continue; |
65e19f54 | 4169 | fpl->fp[nr_files] = get_file(file); |
08a45173 JA |
4170 | unix_inflight(fpl->user, fpl->fp[nr_files]); |
4171 | nr_files++; | |
6b06314c JA |
4172 | } |
4173 | ||
08a45173 JA |
4174 | if (nr_files) { |
4175 | fpl->max = SCM_MAX_FD; | |
4176 | fpl->count = nr_files; | |
4177 | UNIXCB(skb).fp = fpl; | |
4178 | skb->destructor = io_destruct_skb; | |
4179 | refcount_add(skb->truesize, &sk->sk_wmem_alloc); | |
4180 | skb_queue_head(&sk->sk_receive_queue, skb); | |
6b06314c | 4181 | |
08a45173 JA |
4182 | for (i = 0; i < nr_files; i++) |
4183 | fput(fpl->fp[i]); | |
4184 | } else { | |
4185 | kfree_skb(skb); | |
4186 | kfree(fpl); | |
4187 | } | |
6b06314c JA |
4188 | |
4189 | return 0; | |
4190 | } | |
4191 | ||
4192 | /* | |
4193 | * If UNIX sockets are enabled, fd passing can cause a reference cycle which | |
4194 | * causes regular reference counting to break down. We rely on the UNIX | |
4195 | * garbage collection to take care of this problem for us. | |
4196 | */ | |
4197 | static int io_sqe_files_scm(struct io_ring_ctx *ctx) | |
4198 | { | |
4199 | unsigned left, total; | |
4200 | int ret = 0; | |
4201 | ||
4202 | total = 0; | |
4203 | left = ctx->nr_user_files; | |
4204 | while (left) { | |
4205 | unsigned this_files = min_t(unsigned, left, SCM_MAX_FD); | |
6b06314c JA |
4206 | |
4207 | ret = __io_sqe_files_scm(ctx, this_files, total); | |
4208 | if (ret) | |
4209 | break; | |
4210 | left -= this_files; | |
4211 | total += this_files; | |
4212 | } | |
4213 | ||
4214 | if (!ret) | |
4215 | return 0; | |
4216 | ||
4217 | while (total < ctx->nr_user_files) { | |
65e19f54 JA |
4218 | struct file *file = io_file_from_index(ctx, total); |
4219 | ||
4220 | if (file) | |
4221 | fput(file); | |
6b06314c JA |
4222 | total++; |
4223 | } | |
4224 | ||
4225 | return ret; | |
4226 | } | |
4227 | #else | |
4228 | static int io_sqe_files_scm(struct io_ring_ctx *ctx) | |
4229 | { | |
4230 | return 0; | |
4231 | } | |
4232 | #endif | |
4233 | ||
65e19f54 JA |
4234 | static int io_sqe_alloc_file_tables(struct io_ring_ctx *ctx, unsigned nr_tables, |
4235 | unsigned nr_files) | |
4236 | { | |
4237 | int i; | |
4238 | ||
4239 | for (i = 0; i < nr_tables; i++) { | |
4240 | struct fixed_file_table *table = &ctx->file_table[i]; | |
4241 | unsigned this_files; | |
4242 | ||
4243 | this_files = min(nr_files, IORING_MAX_FILES_TABLE); | |
4244 | table->files = kcalloc(this_files, sizeof(struct file *), | |
4245 | GFP_KERNEL); | |
4246 | if (!table->files) | |
4247 | break; | |
4248 | nr_files -= this_files; | |
4249 | } | |
4250 | ||
4251 | if (i == nr_tables) | |
4252 | return 0; | |
4253 | ||
4254 | for (i = 0; i < nr_tables; i++) { | |
4255 | struct fixed_file_table *table = &ctx->file_table[i]; | |
4256 | kfree(table->files); | |
4257 | } | |
4258 | return 1; | |
4259 | } | |
4260 | ||
6b06314c JA |
4261 | static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, |
4262 | unsigned nr_args) | |
4263 | { | |
4264 | __s32 __user *fds = (__s32 __user *) arg; | |
65e19f54 | 4265 | unsigned nr_tables; |
6b06314c JA |
4266 | int fd, ret = 0; |
4267 | unsigned i; | |
4268 | ||
65e19f54 | 4269 | if (ctx->file_table) |
6b06314c JA |
4270 | return -EBUSY; |
4271 | if (!nr_args) | |
4272 | return -EINVAL; | |
4273 | if (nr_args > IORING_MAX_FIXED_FILES) | |
4274 | return -EMFILE; | |
4275 | ||
65e19f54 JA |
4276 | nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE); |
4277 | ctx->file_table = kcalloc(nr_tables, sizeof(struct fixed_file_table), | |
4278 | GFP_KERNEL); | |
4279 | if (!ctx->file_table) | |
6b06314c JA |
4280 | return -ENOMEM; |
4281 | ||
65e19f54 JA |
4282 | if (io_sqe_alloc_file_tables(ctx, nr_tables, nr_args)) { |
4283 | kfree(ctx->file_table); | |
46568e9b | 4284 | ctx->file_table = NULL; |
65e19f54 JA |
4285 | return -ENOMEM; |
4286 | } | |
4287 | ||
08a45173 | 4288 | for (i = 0; i < nr_args; i++, ctx->nr_user_files++) { |
65e19f54 JA |
4289 | struct fixed_file_table *table; |
4290 | unsigned index; | |
4291 | ||
6b06314c JA |
4292 | ret = -EFAULT; |
4293 | if (copy_from_user(&fd, &fds[i], sizeof(fd))) | |
4294 | break; | |
08a45173 JA |
4295 | /* allow sparse sets */ |
4296 | if (fd == -1) { | |
4297 | ret = 0; | |
4298 | continue; | |
4299 | } | |
6b06314c | 4300 | |
65e19f54 JA |
4301 | table = &ctx->file_table[i >> IORING_FILE_TABLE_SHIFT]; |
4302 | index = i & IORING_FILE_TABLE_MASK; | |
4303 | table->files[index] = fget(fd); | |
6b06314c JA |
4304 | |
4305 | ret = -EBADF; | |
65e19f54 | 4306 | if (!table->files[index]) |
6b06314c JA |
4307 | break; |
4308 | /* | |
4309 | * Don't allow io_uring instances to be registered. If UNIX | |
4310 | * isn't enabled, then this causes a reference cycle and this | |
4311 | * instance can never get freed. If UNIX is enabled we'll | |
4312 | * handle it just fine, but there's still no point in allowing | |
4313 | * a ring fd as it doesn't support regular read/write anyway. | |
4314 | */ | |
65e19f54 JA |
4315 | if (table->files[index]->f_op == &io_uring_fops) { |
4316 | fput(table->files[index]); | |
6b06314c JA |
4317 | break; |
4318 | } | |
6b06314c JA |
4319 | ret = 0; |
4320 | } | |
4321 | ||
4322 | if (ret) { | |
65e19f54 JA |
4323 | for (i = 0; i < ctx->nr_user_files; i++) { |
4324 | struct file *file; | |
6b06314c | 4325 | |
65e19f54 JA |
4326 | file = io_file_from_index(ctx, i); |
4327 | if (file) | |
4328 | fput(file); | |
4329 | } | |
4330 | for (i = 0; i < nr_tables; i++) | |
4331 | kfree(ctx->file_table[i].files); | |
6b06314c | 4332 | |
65e19f54 JA |
4333 | kfree(ctx->file_table); |
4334 | ctx->file_table = NULL; | |
6b06314c JA |
4335 | ctx->nr_user_files = 0; |
4336 | return ret; | |
4337 | } | |
4338 | ||
4339 | ret = io_sqe_files_scm(ctx); | |
4340 | if (ret) | |
4341 | io_sqe_files_unregister(ctx); | |
4342 | ||
4343 | return ret; | |
4344 | } | |
4345 | ||
c3a31e60 JA |
4346 | static void io_sqe_file_unregister(struct io_ring_ctx *ctx, int index) |
4347 | { | |
4348 | #if defined(CONFIG_UNIX) | |
65e19f54 | 4349 | struct file *file = io_file_from_index(ctx, index); |
c3a31e60 JA |
4350 | struct sock *sock = ctx->ring_sock->sk; |
4351 | struct sk_buff_head list, *head = &sock->sk_receive_queue; | |
4352 | struct sk_buff *skb; | |
4353 | int i; | |
4354 | ||
4355 | __skb_queue_head_init(&list); | |
4356 | ||
4357 | /* | |
4358 | * Find the skb that holds this file in its SCM_RIGHTS. When found, | |
4359 | * remove this entry and rearrange the file array. | |
4360 | */ | |
4361 | skb = skb_dequeue(head); | |
4362 | while (skb) { | |
4363 | struct scm_fp_list *fp; | |
4364 | ||
4365 | fp = UNIXCB(skb).fp; | |
4366 | for (i = 0; i < fp->count; i++) { | |
4367 | int left; | |
4368 | ||
4369 | if (fp->fp[i] != file) | |
4370 | continue; | |
4371 | ||
4372 | unix_notinflight(fp->user, fp->fp[i]); | |
4373 | left = fp->count - 1 - i; | |
4374 | if (left) { | |
4375 | memmove(&fp->fp[i], &fp->fp[i + 1], | |
4376 | left * sizeof(struct file *)); | |
4377 | } | |
4378 | fp->count--; | |
4379 | if (!fp->count) { | |
4380 | kfree_skb(skb); | |
4381 | skb = NULL; | |
4382 | } else { | |
4383 | __skb_queue_tail(&list, skb); | |
4384 | } | |
4385 | fput(file); | |
4386 | file = NULL; | |
4387 | break; | |
4388 | } | |
4389 | ||
4390 | if (!file) | |
4391 | break; | |
4392 | ||
4393 | __skb_queue_tail(&list, skb); | |
4394 | ||
4395 | skb = skb_dequeue(head); | |
4396 | } | |
4397 | ||
4398 | if (skb_peek(&list)) { | |
4399 | spin_lock_irq(&head->lock); | |
4400 | while ((skb = __skb_dequeue(&list)) != NULL) | |
4401 | __skb_queue_tail(head, skb); | |
4402 | spin_unlock_irq(&head->lock); | |
4403 | } | |
4404 | #else | |
65e19f54 | 4405 | fput(io_file_from_index(ctx, index)); |
c3a31e60 JA |
4406 | #endif |
4407 | } | |
4408 | ||
4409 | static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file, | |
4410 | int index) | |
4411 | { | |
4412 | #if defined(CONFIG_UNIX) | |
4413 | struct sock *sock = ctx->ring_sock->sk; | |
4414 | struct sk_buff_head *head = &sock->sk_receive_queue; | |
4415 | struct sk_buff *skb; | |
4416 | ||
4417 | /* | |
4418 | * See if we can merge this file into an existing skb SCM_RIGHTS | |
4419 | * file set. If there's no room, fall back to allocating a new skb | |
4420 | * and filling it in. | |
4421 | */ | |
4422 | spin_lock_irq(&head->lock); | |
4423 | skb = skb_peek(head); | |
4424 | if (skb) { | |
4425 | struct scm_fp_list *fpl = UNIXCB(skb).fp; | |
4426 | ||
4427 | if (fpl->count < SCM_MAX_FD) { | |
4428 | __skb_unlink(skb, head); | |
4429 | spin_unlock_irq(&head->lock); | |
4430 | fpl->fp[fpl->count] = get_file(file); | |
4431 | unix_inflight(fpl->user, fpl->fp[fpl->count]); | |
4432 | fpl->count++; | |
4433 | spin_lock_irq(&head->lock); | |
4434 | __skb_queue_head(head, skb); | |
4435 | } else { | |
4436 | skb = NULL; | |
4437 | } | |
4438 | } | |
4439 | spin_unlock_irq(&head->lock); | |
4440 | ||
4441 | if (skb) { | |
4442 | fput(file); | |
4443 | return 0; | |
4444 | } | |
4445 | ||
4446 | return __io_sqe_files_scm(ctx, 1, index); | |
4447 | #else | |
4448 | return 0; | |
4449 | #endif | |
4450 | } | |
4451 | ||
4452 | static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg, | |
4453 | unsigned nr_args) | |
4454 | { | |
4455 | struct io_uring_files_update up; | |
4456 | __s32 __user *fds; | |
4457 | int fd, i, err; | |
4458 | __u32 done; | |
4459 | ||
65e19f54 | 4460 | if (!ctx->file_table) |
c3a31e60 JA |
4461 | return -ENXIO; |
4462 | if (!nr_args) | |
4463 | return -EINVAL; | |
4464 | if (copy_from_user(&up, arg, sizeof(up))) | |
4465 | return -EFAULT; | |
1292e972 ES |
4466 | if (up.resv) |
4467 | return -EINVAL; | |
c3a31e60 JA |
4468 | if (check_add_overflow(up.offset, nr_args, &done)) |
4469 | return -EOVERFLOW; | |
4470 | if (done > ctx->nr_user_files) | |
4471 | return -EINVAL; | |
4472 | ||
4473 | done = 0; | |
1292e972 | 4474 | fds = u64_to_user_ptr(up.fds); |
c3a31e60 | 4475 | while (nr_args) { |
65e19f54 JA |
4476 | struct fixed_file_table *table; |
4477 | unsigned index; | |
4478 | ||
c3a31e60 JA |
4479 | err = 0; |
4480 | if (copy_from_user(&fd, &fds[done], sizeof(fd))) { | |
4481 | err = -EFAULT; | |
4482 | break; | |
4483 | } | |
4484 | i = array_index_nospec(up.offset, ctx->nr_user_files); | |
65e19f54 JA |
4485 | table = &ctx->file_table[i >> IORING_FILE_TABLE_SHIFT]; |
4486 | index = i & IORING_FILE_TABLE_MASK; | |
4487 | if (table->files[index]) { | |
c3a31e60 | 4488 | io_sqe_file_unregister(ctx, i); |
65e19f54 | 4489 | table->files[index] = NULL; |
c3a31e60 JA |
4490 | } |
4491 | if (fd != -1) { | |
4492 | struct file *file; | |
4493 | ||
4494 | file = fget(fd); | |
4495 | if (!file) { | |
4496 | err = -EBADF; | |
4497 | break; | |
4498 | } | |
4499 | /* | |
4500 | * Don't allow io_uring instances to be registered. If | |
4501 | * UNIX isn't enabled, then this causes a reference | |
4502 | * cycle and this instance can never get freed. If UNIX | |
4503 | * is enabled we'll handle it just fine, but there's | |
4504 | * still no point in allowing a ring fd as it doesn't | |
4505 | * support regular read/write anyway. | |
4506 | */ | |
4507 | if (file->f_op == &io_uring_fops) { | |
4508 | fput(file); | |
4509 | err = -EBADF; | |
4510 | break; | |
4511 | } | |
65e19f54 | 4512 | table->files[index] = file; |
c3a31e60 JA |
4513 | err = io_sqe_file_register(ctx, file, i); |
4514 | if (err) | |
4515 | break; | |
4516 | } | |
4517 | nr_args--; | |
4518 | done++; | |
4519 | up.offset++; | |
4520 | } | |
4521 | ||
4522 | return done ? done : err; | |
4523 | } | |
4524 | ||
7d723065 JA |
4525 | static void io_put_work(struct io_wq_work *work) |
4526 | { | |
4527 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
4528 | ||
4529 | io_put_req(req); | |
4530 | } | |
4531 | ||
4532 | static void io_get_work(struct io_wq_work *work) | |
4533 | { | |
4534 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
4535 | ||
4536 | refcount_inc(&req->refs); | |
4537 | } | |
4538 | ||
6c271ce2 JA |
4539 | static int io_sq_offload_start(struct io_ring_ctx *ctx, |
4540 | struct io_uring_params *p) | |
2b188cc1 | 4541 | { |
576a347b | 4542 | struct io_wq_data data; |
561fb04a | 4543 | unsigned concurrency; |
2b188cc1 JA |
4544 | int ret; |
4545 | ||
6c271ce2 | 4546 | init_waitqueue_head(&ctx->sqo_wait); |
2b188cc1 JA |
4547 | mmgrab(current->mm); |
4548 | ctx->sqo_mm = current->mm; | |
4549 | ||
6c271ce2 | 4550 | if (ctx->flags & IORING_SETUP_SQPOLL) { |
3ec482d1 JA |
4551 | ret = -EPERM; |
4552 | if (!capable(CAP_SYS_ADMIN)) | |
4553 | goto err; | |
4554 | ||
917257da JA |
4555 | ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle); |
4556 | if (!ctx->sq_thread_idle) | |
4557 | ctx->sq_thread_idle = HZ; | |
4558 | ||
6c271ce2 | 4559 | if (p->flags & IORING_SETUP_SQ_AFF) { |
44a9bd18 | 4560 | int cpu = p->sq_thread_cpu; |
6c271ce2 | 4561 | |
917257da | 4562 | ret = -EINVAL; |
44a9bd18 JA |
4563 | if (cpu >= nr_cpu_ids) |
4564 | goto err; | |
7889f44d | 4565 | if (!cpu_online(cpu)) |
917257da JA |
4566 | goto err; |
4567 | ||
6c271ce2 JA |
4568 | ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread, |
4569 | ctx, cpu, | |
4570 | "io_uring-sq"); | |
4571 | } else { | |
4572 | ctx->sqo_thread = kthread_create(io_sq_thread, ctx, | |
4573 | "io_uring-sq"); | |
4574 | } | |
4575 | if (IS_ERR(ctx->sqo_thread)) { | |
4576 | ret = PTR_ERR(ctx->sqo_thread); | |
4577 | ctx->sqo_thread = NULL; | |
4578 | goto err; | |
4579 | } | |
4580 | wake_up_process(ctx->sqo_thread); | |
4581 | } else if (p->flags & IORING_SETUP_SQ_AFF) { | |
4582 | /* Can't have SQ_AFF without SQPOLL */ | |
4583 | ret = -EINVAL; | |
4584 | goto err; | |
4585 | } | |
4586 | ||
576a347b JA |
4587 | data.mm = ctx->sqo_mm; |
4588 | data.user = ctx->user; | |
181e448d | 4589 | data.creds = ctx->creds; |
576a347b JA |
4590 | data.get_work = io_get_work; |
4591 | data.put_work = io_put_work; | |
4592 | ||
561fb04a JA |
4593 | /* Do QD, or 4 * CPUS, whatever is smallest */ |
4594 | concurrency = min(ctx->sq_entries, 4 * num_online_cpus()); | |
576a347b | 4595 | ctx->io_wq = io_wq_create(concurrency, &data); |
975c99a5 JA |
4596 | if (IS_ERR(ctx->io_wq)) { |
4597 | ret = PTR_ERR(ctx->io_wq); | |
4598 | ctx->io_wq = NULL; | |
2b188cc1 JA |
4599 | goto err; |
4600 | } | |
4601 | ||
4602 | return 0; | |
4603 | err: | |
54a91f3b | 4604 | io_finish_async(ctx); |
2b188cc1 JA |
4605 | mmdrop(ctx->sqo_mm); |
4606 | ctx->sqo_mm = NULL; | |
4607 | return ret; | |
4608 | } | |
4609 | ||
4610 | static void io_unaccount_mem(struct user_struct *user, unsigned long nr_pages) | |
4611 | { | |
4612 | atomic_long_sub(nr_pages, &user->locked_vm); | |
4613 | } | |
4614 | ||
4615 | static int io_account_mem(struct user_struct *user, unsigned long nr_pages) | |
4616 | { | |
4617 | unsigned long page_limit, cur_pages, new_pages; | |
4618 | ||
4619 | /* Don't allow more pages than we can safely lock */ | |
4620 | page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
4621 | ||
4622 | do { | |
4623 | cur_pages = atomic_long_read(&user->locked_vm); | |
4624 | new_pages = cur_pages + nr_pages; | |
4625 | if (new_pages > page_limit) | |
4626 | return -ENOMEM; | |
4627 | } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages, | |
4628 | new_pages) != cur_pages); | |
4629 | ||
4630 | return 0; | |
4631 | } | |
4632 | ||
4633 | static void io_mem_free(void *ptr) | |
4634 | { | |
52e04ef4 MR |
4635 | struct page *page; |
4636 | ||
4637 | if (!ptr) | |
4638 | return; | |
2b188cc1 | 4639 | |
52e04ef4 | 4640 | page = virt_to_head_page(ptr); |
2b188cc1 JA |
4641 | if (put_page_testzero(page)) |
4642 | free_compound_page(page); | |
4643 | } | |
4644 | ||
4645 | static void *io_mem_alloc(size_t size) | |
4646 | { | |
4647 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP | | |
4648 | __GFP_NORETRY; | |
4649 | ||
4650 | return (void *) __get_free_pages(gfp_flags, get_order(size)); | |
4651 | } | |
4652 | ||
75b28aff HV |
4653 | static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries, |
4654 | size_t *sq_offset) | |
4655 | { | |
4656 | struct io_rings *rings; | |
4657 | size_t off, sq_array_size; | |
4658 | ||
4659 | off = struct_size(rings, cqes, cq_entries); | |
4660 | if (off == SIZE_MAX) | |
4661 | return SIZE_MAX; | |
4662 | ||
4663 | #ifdef CONFIG_SMP | |
4664 | off = ALIGN(off, SMP_CACHE_BYTES); | |
4665 | if (off == 0) | |
4666 | return SIZE_MAX; | |
4667 | #endif | |
4668 | ||
4669 | sq_array_size = array_size(sizeof(u32), sq_entries); | |
4670 | if (sq_array_size == SIZE_MAX) | |
4671 | return SIZE_MAX; | |
4672 | ||
4673 | if (check_add_overflow(off, sq_array_size, &off)) | |
4674 | return SIZE_MAX; | |
4675 | ||
4676 | if (sq_offset) | |
4677 | *sq_offset = off; | |
4678 | ||
4679 | return off; | |
4680 | } | |
4681 | ||
2b188cc1 JA |
4682 | static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries) |
4683 | { | |
75b28aff | 4684 | size_t pages; |
2b188cc1 | 4685 | |
75b28aff HV |
4686 | pages = (size_t)1 << get_order( |
4687 | rings_size(sq_entries, cq_entries, NULL)); | |
4688 | pages += (size_t)1 << get_order( | |
4689 | array_size(sizeof(struct io_uring_sqe), sq_entries)); | |
2b188cc1 | 4690 | |
75b28aff | 4691 | return pages; |
2b188cc1 JA |
4692 | } |
4693 | ||
edafccee JA |
4694 | static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx) |
4695 | { | |
4696 | int i, j; | |
4697 | ||
4698 | if (!ctx->user_bufs) | |
4699 | return -ENXIO; | |
4700 | ||
4701 | for (i = 0; i < ctx->nr_user_bufs; i++) { | |
4702 | struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; | |
4703 | ||
4704 | for (j = 0; j < imu->nr_bvecs; j++) | |
27c4d3a3 | 4705 | put_user_page(imu->bvec[j].bv_page); |
edafccee JA |
4706 | |
4707 | if (ctx->account_mem) | |
4708 | io_unaccount_mem(ctx->user, imu->nr_bvecs); | |
d4ef6475 | 4709 | kvfree(imu->bvec); |
edafccee JA |
4710 | imu->nr_bvecs = 0; |
4711 | } | |
4712 | ||
4713 | kfree(ctx->user_bufs); | |
4714 | ctx->user_bufs = NULL; | |
4715 | ctx->nr_user_bufs = 0; | |
4716 | return 0; | |
4717 | } | |
4718 | ||
4719 | static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, | |
4720 | void __user *arg, unsigned index) | |
4721 | { | |
4722 | struct iovec __user *src; | |
4723 | ||
4724 | #ifdef CONFIG_COMPAT | |
4725 | if (ctx->compat) { | |
4726 | struct compat_iovec __user *ciovs; | |
4727 | struct compat_iovec ciov; | |
4728 | ||
4729 | ciovs = (struct compat_iovec __user *) arg; | |
4730 | if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov))) | |
4731 | return -EFAULT; | |
4732 | ||
d55e5f5b | 4733 | dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base); |
edafccee JA |
4734 | dst->iov_len = ciov.iov_len; |
4735 | return 0; | |
4736 | } | |
4737 | #endif | |
4738 | src = (struct iovec __user *) arg; | |
4739 | if (copy_from_user(dst, &src[index], sizeof(*dst))) | |
4740 | return -EFAULT; | |
4741 | return 0; | |
4742 | } | |
4743 | ||
4744 | static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, | |
4745 | unsigned nr_args) | |
4746 | { | |
4747 | struct vm_area_struct **vmas = NULL; | |
4748 | struct page **pages = NULL; | |
4749 | int i, j, got_pages = 0; | |
4750 | int ret = -EINVAL; | |
4751 | ||
4752 | if (ctx->user_bufs) | |
4753 | return -EBUSY; | |
4754 | if (!nr_args || nr_args > UIO_MAXIOV) | |
4755 | return -EINVAL; | |
4756 | ||
4757 | ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf), | |
4758 | GFP_KERNEL); | |
4759 | if (!ctx->user_bufs) | |
4760 | return -ENOMEM; | |
4761 | ||
4762 | for (i = 0; i < nr_args; i++) { | |
4763 | struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; | |
4764 | unsigned long off, start, end, ubuf; | |
4765 | int pret, nr_pages; | |
4766 | struct iovec iov; | |
4767 | size_t size; | |
4768 | ||
4769 | ret = io_copy_iov(ctx, &iov, arg, i); | |
4770 | if (ret) | |
a278682d | 4771 | goto err; |
edafccee JA |
4772 | |
4773 | /* | |
4774 | * Don't impose further limits on the size and buffer | |
4775 | * constraints here, we'll -EINVAL later when IO is | |
4776 | * submitted if they are wrong. | |
4777 | */ | |
4778 | ret = -EFAULT; | |
4779 | if (!iov.iov_base || !iov.iov_len) | |
4780 | goto err; | |
4781 | ||
4782 | /* arbitrary limit, but we need something */ | |
4783 | if (iov.iov_len > SZ_1G) | |
4784 | goto err; | |
4785 | ||
4786 | ubuf = (unsigned long) iov.iov_base; | |
4787 | end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
4788 | start = ubuf >> PAGE_SHIFT; | |
4789 | nr_pages = end - start; | |
4790 | ||
4791 | if (ctx->account_mem) { | |
4792 | ret = io_account_mem(ctx->user, nr_pages); | |
4793 | if (ret) | |
4794 | goto err; | |
4795 | } | |
4796 | ||
4797 | ret = 0; | |
4798 | if (!pages || nr_pages > got_pages) { | |
4799 | kfree(vmas); | |
4800 | kfree(pages); | |
d4ef6475 | 4801 | pages = kvmalloc_array(nr_pages, sizeof(struct page *), |
edafccee | 4802 | GFP_KERNEL); |
d4ef6475 | 4803 | vmas = kvmalloc_array(nr_pages, |
edafccee JA |
4804 | sizeof(struct vm_area_struct *), |
4805 | GFP_KERNEL); | |
4806 | if (!pages || !vmas) { | |
4807 | ret = -ENOMEM; | |
4808 | if (ctx->account_mem) | |
4809 | io_unaccount_mem(ctx->user, nr_pages); | |
4810 | goto err; | |
4811 | } | |
4812 | got_pages = nr_pages; | |
4813 | } | |
4814 | ||
d4ef6475 | 4815 | imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec), |
edafccee JA |
4816 | GFP_KERNEL); |
4817 | ret = -ENOMEM; | |
4818 | if (!imu->bvec) { | |
4819 | if (ctx->account_mem) | |
4820 | io_unaccount_mem(ctx->user, nr_pages); | |
4821 | goto err; | |
4822 | } | |
4823 | ||
4824 | ret = 0; | |
4825 | down_read(¤t->mm->mmap_sem); | |
932f4a63 IW |
4826 | pret = get_user_pages(ubuf, nr_pages, |
4827 | FOLL_WRITE | FOLL_LONGTERM, | |
4828 | pages, vmas); | |
edafccee JA |
4829 | if (pret == nr_pages) { |
4830 | /* don't support file backed memory */ | |
4831 | for (j = 0; j < nr_pages; j++) { | |
4832 | struct vm_area_struct *vma = vmas[j]; | |
4833 | ||
4834 | if (vma->vm_file && | |
4835 | !is_file_hugepages(vma->vm_file)) { | |
4836 | ret = -EOPNOTSUPP; | |
4837 | break; | |
4838 | } | |
4839 | } | |
4840 | } else { | |
4841 | ret = pret < 0 ? pret : -EFAULT; | |
4842 | } | |
4843 | up_read(¤t->mm->mmap_sem); | |
4844 | if (ret) { | |
4845 | /* | |
4846 | * if we did partial map, or found file backed vmas, | |
4847 | * release any pages we did get | |
4848 | */ | |
27c4d3a3 JH |
4849 | if (pret > 0) |
4850 | put_user_pages(pages, pret); | |
edafccee JA |
4851 | if (ctx->account_mem) |
4852 | io_unaccount_mem(ctx->user, nr_pages); | |
d4ef6475 | 4853 | kvfree(imu->bvec); |
edafccee JA |
4854 | goto err; |
4855 | } | |
4856 | ||
4857 | off = ubuf & ~PAGE_MASK; | |
4858 | size = iov.iov_len; | |
4859 | for (j = 0; j < nr_pages; j++) { | |
4860 | size_t vec_len; | |
4861 | ||
4862 | vec_len = min_t(size_t, size, PAGE_SIZE - off); | |
4863 | imu->bvec[j].bv_page = pages[j]; | |
4864 | imu->bvec[j].bv_len = vec_len; | |
4865 | imu->bvec[j].bv_offset = off; | |
4866 | off = 0; | |
4867 | size -= vec_len; | |
4868 | } | |
4869 | /* store original address for later verification */ | |
4870 | imu->ubuf = ubuf; | |
4871 | imu->len = iov.iov_len; | |
4872 | imu->nr_bvecs = nr_pages; | |
4873 | ||
4874 | ctx->nr_user_bufs++; | |
4875 | } | |
d4ef6475 MR |
4876 | kvfree(pages); |
4877 | kvfree(vmas); | |
edafccee JA |
4878 | return 0; |
4879 | err: | |
d4ef6475 MR |
4880 | kvfree(pages); |
4881 | kvfree(vmas); | |
edafccee JA |
4882 | io_sqe_buffer_unregister(ctx); |
4883 | return ret; | |
4884 | } | |
4885 | ||
9b402849 JA |
4886 | static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg) |
4887 | { | |
4888 | __s32 __user *fds = arg; | |
4889 | int fd; | |
4890 | ||
4891 | if (ctx->cq_ev_fd) | |
4892 | return -EBUSY; | |
4893 | ||
4894 | if (copy_from_user(&fd, fds, sizeof(*fds))) | |
4895 | return -EFAULT; | |
4896 | ||
4897 | ctx->cq_ev_fd = eventfd_ctx_fdget(fd); | |
4898 | if (IS_ERR(ctx->cq_ev_fd)) { | |
4899 | int ret = PTR_ERR(ctx->cq_ev_fd); | |
4900 | ctx->cq_ev_fd = NULL; | |
4901 | return ret; | |
4902 | } | |
4903 | ||
4904 | return 0; | |
4905 | } | |
4906 | ||
4907 | static int io_eventfd_unregister(struct io_ring_ctx *ctx) | |
4908 | { | |
4909 | if (ctx->cq_ev_fd) { | |
4910 | eventfd_ctx_put(ctx->cq_ev_fd); | |
4911 | ctx->cq_ev_fd = NULL; | |
4912 | return 0; | |
4913 | } | |
4914 | ||
4915 | return -ENXIO; | |
4916 | } | |
4917 | ||
2b188cc1 JA |
4918 | static void io_ring_ctx_free(struct io_ring_ctx *ctx) |
4919 | { | |
6b06314c | 4920 | io_finish_async(ctx); |
2b188cc1 JA |
4921 | if (ctx->sqo_mm) |
4922 | mmdrop(ctx->sqo_mm); | |
def596e9 JA |
4923 | |
4924 | io_iopoll_reap_events(ctx); | |
edafccee | 4925 | io_sqe_buffer_unregister(ctx); |
6b06314c | 4926 | io_sqe_files_unregister(ctx); |
9b402849 | 4927 | io_eventfd_unregister(ctx); |
def596e9 | 4928 | |
2b188cc1 | 4929 | #if defined(CONFIG_UNIX) |
355e8d26 EB |
4930 | if (ctx->ring_sock) { |
4931 | ctx->ring_sock->file = NULL; /* so that iput() is called */ | |
2b188cc1 | 4932 | sock_release(ctx->ring_sock); |
355e8d26 | 4933 | } |
2b188cc1 JA |
4934 | #endif |
4935 | ||
75b28aff | 4936 | io_mem_free(ctx->rings); |
2b188cc1 | 4937 | io_mem_free(ctx->sq_sqes); |
2b188cc1 JA |
4938 | |
4939 | percpu_ref_exit(&ctx->refs); | |
4940 | if (ctx->account_mem) | |
4941 | io_unaccount_mem(ctx->user, | |
4942 | ring_pages(ctx->sq_entries, ctx->cq_entries)); | |
4943 | free_uid(ctx->user); | |
181e448d | 4944 | put_cred(ctx->creds); |
206aefde | 4945 | kfree(ctx->completions); |
78076bb6 | 4946 | kfree(ctx->cancel_hash); |
0ddf92e8 | 4947 | kmem_cache_free(req_cachep, ctx->fallback_req); |
2b188cc1 JA |
4948 | kfree(ctx); |
4949 | } | |
4950 | ||
4951 | static __poll_t io_uring_poll(struct file *file, poll_table *wait) | |
4952 | { | |
4953 | struct io_ring_ctx *ctx = file->private_data; | |
4954 | __poll_t mask = 0; | |
4955 | ||
4956 | poll_wait(file, &ctx->cq_wait, wait); | |
4f7067c3 SB |
4957 | /* |
4958 | * synchronizes with barrier from wq_has_sleeper call in | |
4959 | * io_commit_cqring | |
4960 | */ | |
2b188cc1 | 4961 | smp_rmb(); |
75b28aff HV |
4962 | if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head != |
4963 | ctx->rings->sq_ring_entries) | |
2b188cc1 | 4964 | mask |= EPOLLOUT | EPOLLWRNORM; |
daa5de54 | 4965 | if (READ_ONCE(ctx->rings->cq.head) != ctx->cached_cq_tail) |
2b188cc1 JA |
4966 | mask |= EPOLLIN | EPOLLRDNORM; |
4967 | ||
4968 | return mask; | |
4969 | } | |
4970 | ||
4971 | static int io_uring_fasync(int fd, struct file *file, int on) | |
4972 | { | |
4973 | struct io_ring_ctx *ctx = file->private_data; | |
4974 | ||
4975 | return fasync_helper(fd, file, on, &ctx->cq_fasync); | |
4976 | } | |
4977 | ||
4978 | static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) | |
4979 | { | |
4980 | mutex_lock(&ctx->uring_lock); | |
4981 | percpu_ref_kill(&ctx->refs); | |
4982 | mutex_unlock(&ctx->uring_lock); | |
4983 | ||
5262f567 | 4984 | io_kill_timeouts(ctx); |
221c5eb2 | 4985 | io_poll_remove_all(ctx); |
561fb04a JA |
4986 | |
4987 | if (ctx->io_wq) | |
4988 | io_wq_cancel_all(ctx->io_wq); | |
4989 | ||
def596e9 | 4990 | io_iopoll_reap_events(ctx); |
15dff286 JA |
4991 | /* if we failed setting up the ctx, we might not have any rings */ |
4992 | if (ctx->rings) | |
4993 | io_cqring_overflow_flush(ctx, true); | |
206aefde | 4994 | wait_for_completion(&ctx->completions[0]); |
2b188cc1 JA |
4995 | io_ring_ctx_free(ctx); |
4996 | } | |
4997 | ||
4998 | static int io_uring_release(struct inode *inode, struct file *file) | |
4999 | { | |
5000 | struct io_ring_ctx *ctx = file->private_data; | |
5001 | ||
5002 | file->private_data = NULL; | |
5003 | io_ring_ctx_wait_and_kill(ctx); | |
5004 | return 0; | |
5005 | } | |
5006 | ||
fcb323cc JA |
5007 | static void io_uring_cancel_files(struct io_ring_ctx *ctx, |
5008 | struct files_struct *files) | |
5009 | { | |
5010 | struct io_kiocb *req; | |
5011 | DEFINE_WAIT(wait); | |
5012 | ||
5013 | while (!list_empty_careful(&ctx->inflight_list)) { | |
768134d4 | 5014 | struct io_kiocb *cancel_req = NULL; |
fcb323cc JA |
5015 | |
5016 | spin_lock_irq(&ctx->inflight_lock); | |
5017 | list_for_each_entry(req, &ctx->inflight_list, inflight_entry) { | |
768134d4 JA |
5018 | if (req->work.files != files) |
5019 | continue; | |
5020 | /* req is being completed, ignore */ | |
5021 | if (!refcount_inc_not_zero(&req->refs)) | |
5022 | continue; | |
5023 | cancel_req = req; | |
5024 | break; | |
fcb323cc | 5025 | } |
768134d4 | 5026 | if (cancel_req) |
fcb323cc | 5027 | prepare_to_wait(&ctx->inflight_wait, &wait, |
768134d4 | 5028 | TASK_UNINTERRUPTIBLE); |
fcb323cc JA |
5029 | spin_unlock_irq(&ctx->inflight_lock); |
5030 | ||
768134d4 JA |
5031 | /* We need to keep going until we don't find a matching req */ |
5032 | if (!cancel_req) | |
fcb323cc | 5033 | break; |
2f6d9b9d BL |
5034 | |
5035 | io_wq_cancel_work(ctx->io_wq, &cancel_req->work); | |
5036 | io_put_req(cancel_req); | |
fcb323cc JA |
5037 | schedule(); |
5038 | } | |
768134d4 | 5039 | finish_wait(&ctx->inflight_wait, &wait); |
fcb323cc JA |
5040 | } |
5041 | ||
5042 | static int io_uring_flush(struct file *file, void *data) | |
5043 | { | |
5044 | struct io_ring_ctx *ctx = file->private_data; | |
5045 | ||
5046 | io_uring_cancel_files(ctx, data); | |
1d7bb1d5 JA |
5047 | if (fatal_signal_pending(current) || (current->flags & PF_EXITING)) { |
5048 | io_cqring_overflow_flush(ctx, true); | |
fcb323cc | 5049 | io_wq_cancel_all(ctx->io_wq); |
1d7bb1d5 | 5050 | } |
fcb323cc JA |
5051 | return 0; |
5052 | } | |
5053 | ||
6c5c240e RP |
5054 | static void *io_uring_validate_mmap_request(struct file *file, |
5055 | loff_t pgoff, size_t sz) | |
2b188cc1 | 5056 | { |
2b188cc1 | 5057 | struct io_ring_ctx *ctx = file->private_data; |
6c5c240e | 5058 | loff_t offset = pgoff << PAGE_SHIFT; |
2b188cc1 JA |
5059 | struct page *page; |
5060 | void *ptr; | |
5061 | ||
5062 | switch (offset) { | |
5063 | case IORING_OFF_SQ_RING: | |
75b28aff HV |
5064 | case IORING_OFF_CQ_RING: |
5065 | ptr = ctx->rings; | |
2b188cc1 JA |
5066 | break; |
5067 | case IORING_OFF_SQES: | |
5068 | ptr = ctx->sq_sqes; | |
5069 | break; | |
2b188cc1 | 5070 | default: |
6c5c240e | 5071 | return ERR_PTR(-EINVAL); |
2b188cc1 JA |
5072 | } |
5073 | ||
5074 | page = virt_to_head_page(ptr); | |
a50b854e | 5075 | if (sz > page_size(page)) |
6c5c240e RP |
5076 | return ERR_PTR(-EINVAL); |
5077 | ||
5078 | return ptr; | |
5079 | } | |
5080 | ||
5081 | #ifdef CONFIG_MMU | |
5082 | ||
5083 | static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) | |
5084 | { | |
5085 | size_t sz = vma->vm_end - vma->vm_start; | |
5086 | unsigned long pfn; | |
5087 | void *ptr; | |
5088 | ||
5089 | ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz); | |
5090 | if (IS_ERR(ptr)) | |
5091 | return PTR_ERR(ptr); | |
2b188cc1 JA |
5092 | |
5093 | pfn = virt_to_phys(ptr) >> PAGE_SHIFT; | |
5094 | return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); | |
5095 | } | |
5096 | ||
6c5c240e RP |
5097 | #else /* !CONFIG_MMU */ |
5098 | ||
5099 | static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) | |
5100 | { | |
5101 | return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL; | |
5102 | } | |
5103 | ||
5104 | static unsigned int io_uring_nommu_mmap_capabilities(struct file *file) | |
5105 | { | |
5106 | return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE; | |
5107 | } | |
5108 | ||
5109 | static unsigned long io_uring_nommu_get_unmapped_area(struct file *file, | |
5110 | unsigned long addr, unsigned long len, | |
5111 | unsigned long pgoff, unsigned long flags) | |
5112 | { | |
5113 | void *ptr; | |
5114 | ||
5115 | ptr = io_uring_validate_mmap_request(file, pgoff, len); | |
5116 | if (IS_ERR(ptr)) | |
5117 | return PTR_ERR(ptr); | |
5118 | ||
5119 | return (unsigned long) ptr; | |
5120 | } | |
5121 | ||
5122 | #endif /* !CONFIG_MMU */ | |
5123 | ||
2b188cc1 JA |
5124 | SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, |
5125 | u32, min_complete, u32, flags, const sigset_t __user *, sig, | |
5126 | size_t, sigsz) | |
5127 | { | |
5128 | struct io_ring_ctx *ctx; | |
5129 | long ret = -EBADF; | |
5130 | int submitted = 0; | |
5131 | struct fd f; | |
5132 | ||
6c271ce2 | 5133 | if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP)) |
2b188cc1 JA |
5134 | return -EINVAL; |
5135 | ||
5136 | f = fdget(fd); | |
5137 | if (!f.file) | |
5138 | return -EBADF; | |
5139 | ||
5140 | ret = -EOPNOTSUPP; | |
5141 | if (f.file->f_op != &io_uring_fops) | |
5142 | goto out_fput; | |
5143 | ||
5144 | ret = -ENXIO; | |
5145 | ctx = f.file->private_data; | |
5146 | if (!percpu_ref_tryget(&ctx->refs)) | |
5147 | goto out_fput; | |
5148 | ||
6c271ce2 JA |
5149 | /* |
5150 | * For SQ polling, the thread will do all submissions and completions. | |
5151 | * Just return the requested submit count, and wake the thread if | |
5152 | * we were asked to. | |
5153 | */ | |
b2a9eada | 5154 | ret = 0; |
6c271ce2 | 5155 | if (ctx->flags & IORING_SETUP_SQPOLL) { |
c1edbf5f JA |
5156 | if (!list_empty_careful(&ctx->cq_overflow_list)) |
5157 | io_cqring_overflow_flush(ctx, false); | |
6c271ce2 JA |
5158 | if (flags & IORING_ENTER_SQ_WAKEUP) |
5159 | wake_up(&ctx->sqo_wait); | |
5160 | submitted = to_submit; | |
b2a9eada | 5161 | } else if (to_submit) { |
ae9428ca | 5162 | struct mm_struct *cur_mm; |
2b188cc1 | 5163 | |
44d28279 JA |
5164 | if (current->mm != ctx->sqo_mm || |
5165 | current_cred() != ctx->creds) { | |
5166 | ret = -EPERM; | |
5167 | goto out; | |
5168 | } | |
5169 | ||
ae9428ca | 5170 | to_submit = min(to_submit, ctx->sq_entries); |
2b188cc1 | 5171 | mutex_lock(&ctx->uring_lock); |
ae9428ca PB |
5172 | /* already have mm, so io_submit_sqes() won't try to grab it */ |
5173 | cur_mm = ctx->sqo_mm; | |
5174 | submitted = io_submit_sqes(ctx, to_submit, f.file, fd, | |
5175 | &cur_mm, false); | |
2b188cc1 | 5176 | mutex_unlock(&ctx->uring_lock); |
7c504e65 PB |
5177 | |
5178 | if (submitted != to_submit) | |
5179 | goto out; | |
2b188cc1 JA |
5180 | } |
5181 | if (flags & IORING_ENTER_GETEVENTS) { | |
def596e9 JA |
5182 | unsigned nr_events = 0; |
5183 | ||
2b188cc1 JA |
5184 | min_complete = min(min_complete, ctx->cq_entries); |
5185 | ||
def596e9 | 5186 | if (ctx->flags & IORING_SETUP_IOPOLL) { |
def596e9 | 5187 | ret = io_iopoll_check(ctx, &nr_events, min_complete); |
def596e9 JA |
5188 | } else { |
5189 | ret = io_cqring_wait(ctx, min_complete, sig, sigsz); | |
5190 | } | |
2b188cc1 JA |
5191 | } |
5192 | ||
7c504e65 | 5193 | out: |
6805b32e | 5194 | percpu_ref_put(&ctx->refs); |
2b188cc1 JA |
5195 | out_fput: |
5196 | fdput(f); | |
5197 | return submitted ? submitted : ret; | |
5198 | } | |
5199 | ||
5200 | static const struct file_operations io_uring_fops = { | |
5201 | .release = io_uring_release, | |
fcb323cc | 5202 | .flush = io_uring_flush, |
2b188cc1 | 5203 | .mmap = io_uring_mmap, |
6c5c240e RP |
5204 | #ifndef CONFIG_MMU |
5205 | .get_unmapped_area = io_uring_nommu_get_unmapped_area, | |
5206 | .mmap_capabilities = io_uring_nommu_mmap_capabilities, | |
5207 | #endif | |
2b188cc1 JA |
5208 | .poll = io_uring_poll, |
5209 | .fasync = io_uring_fasync, | |
5210 | }; | |
5211 | ||
5212 | static int io_allocate_scq_urings(struct io_ring_ctx *ctx, | |
5213 | struct io_uring_params *p) | |
5214 | { | |
75b28aff HV |
5215 | struct io_rings *rings; |
5216 | size_t size, sq_array_offset; | |
2b188cc1 | 5217 | |
75b28aff HV |
5218 | size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset); |
5219 | if (size == SIZE_MAX) | |
5220 | return -EOVERFLOW; | |
5221 | ||
5222 | rings = io_mem_alloc(size); | |
5223 | if (!rings) | |
2b188cc1 JA |
5224 | return -ENOMEM; |
5225 | ||
75b28aff HV |
5226 | ctx->rings = rings; |
5227 | ctx->sq_array = (u32 *)((char *)rings + sq_array_offset); | |
5228 | rings->sq_ring_mask = p->sq_entries - 1; | |
5229 | rings->cq_ring_mask = p->cq_entries - 1; | |
5230 | rings->sq_ring_entries = p->sq_entries; | |
5231 | rings->cq_ring_entries = p->cq_entries; | |
5232 | ctx->sq_mask = rings->sq_ring_mask; | |
5233 | ctx->cq_mask = rings->cq_ring_mask; | |
5234 | ctx->sq_entries = rings->sq_ring_entries; | |
5235 | ctx->cq_entries = rings->cq_ring_entries; | |
2b188cc1 JA |
5236 | |
5237 | size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); | |
eb065d30 JA |
5238 | if (size == SIZE_MAX) { |
5239 | io_mem_free(ctx->rings); | |
5240 | ctx->rings = NULL; | |
2b188cc1 | 5241 | return -EOVERFLOW; |
eb065d30 | 5242 | } |
2b188cc1 JA |
5243 | |
5244 | ctx->sq_sqes = io_mem_alloc(size); | |
eb065d30 JA |
5245 | if (!ctx->sq_sqes) { |
5246 | io_mem_free(ctx->rings); | |
5247 | ctx->rings = NULL; | |
2b188cc1 | 5248 | return -ENOMEM; |
eb065d30 | 5249 | } |
2b188cc1 | 5250 | |
2b188cc1 JA |
5251 | return 0; |
5252 | } | |
5253 | ||
5254 | /* | |
5255 | * Allocate an anonymous fd, this is what constitutes the application | |
5256 | * visible backing of an io_uring instance. The application mmaps this | |
5257 | * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled, | |
5258 | * we have to tie this fd to a socket for file garbage collection purposes. | |
5259 | */ | |
5260 | static int io_uring_get_fd(struct io_ring_ctx *ctx) | |
5261 | { | |
5262 | struct file *file; | |
5263 | int ret; | |
5264 | ||
5265 | #if defined(CONFIG_UNIX) | |
5266 | ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP, | |
5267 | &ctx->ring_sock); | |
5268 | if (ret) | |
5269 | return ret; | |
5270 | #endif | |
5271 | ||
5272 | ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC); | |
5273 | if (ret < 0) | |
5274 | goto err; | |
5275 | ||
5276 | file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx, | |
5277 | O_RDWR | O_CLOEXEC); | |
5278 | if (IS_ERR(file)) { | |
5279 | put_unused_fd(ret); | |
5280 | ret = PTR_ERR(file); | |
5281 | goto err; | |
5282 | } | |
5283 | ||
5284 | #if defined(CONFIG_UNIX) | |
5285 | ctx->ring_sock->file = file; | |
6b06314c | 5286 | ctx->ring_sock->sk->sk_user_data = ctx; |
2b188cc1 JA |
5287 | #endif |
5288 | fd_install(ret, file); | |
5289 | return ret; | |
5290 | err: | |
5291 | #if defined(CONFIG_UNIX) | |
5292 | sock_release(ctx->ring_sock); | |
5293 | ctx->ring_sock = NULL; | |
5294 | #endif | |
5295 | return ret; | |
5296 | } | |
5297 | ||
5298 | static int io_uring_create(unsigned entries, struct io_uring_params *p) | |
5299 | { | |
5300 | struct user_struct *user = NULL; | |
5301 | struct io_ring_ctx *ctx; | |
5302 | bool account_mem; | |
5303 | int ret; | |
5304 | ||
5305 | if (!entries || entries > IORING_MAX_ENTRIES) | |
5306 | return -EINVAL; | |
5307 | ||
5308 | /* | |
5309 | * Use twice as many entries for the CQ ring. It's possible for the | |
5310 | * application to drive a higher depth than the size of the SQ ring, | |
5311 | * since the sqes are only used at submission time. This allows for | |
33a107f0 JA |
5312 | * some flexibility in overcommitting a bit. If the application has |
5313 | * set IORING_SETUP_CQSIZE, it will have passed in the desired number | |
5314 | * of CQ ring entries manually. | |
2b188cc1 JA |
5315 | */ |
5316 | p->sq_entries = roundup_pow_of_two(entries); | |
33a107f0 JA |
5317 | if (p->flags & IORING_SETUP_CQSIZE) { |
5318 | /* | |
5319 | * If IORING_SETUP_CQSIZE is set, we do the same roundup | |
5320 | * to a power-of-two, if it isn't already. We do NOT impose | |
5321 | * any cq vs sq ring sizing. | |
5322 | */ | |
5323 | if (p->cq_entries < p->sq_entries || p->cq_entries > IORING_MAX_CQ_ENTRIES) | |
5324 | return -EINVAL; | |
5325 | p->cq_entries = roundup_pow_of_two(p->cq_entries); | |
5326 | } else { | |
5327 | p->cq_entries = 2 * p->sq_entries; | |
5328 | } | |
2b188cc1 JA |
5329 | |
5330 | user = get_uid(current_user()); | |
5331 | account_mem = !capable(CAP_IPC_LOCK); | |
5332 | ||
5333 | if (account_mem) { | |
5334 | ret = io_account_mem(user, | |
5335 | ring_pages(p->sq_entries, p->cq_entries)); | |
5336 | if (ret) { | |
5337 | free_uid(user); | |
5338 | return ret; | |
5339 | } | |
5340 | } | |
5341 | ||
5342 | ctx = io_ring_ctx_alloc(p); | |
5343 | if (!ctx) { | |
5344 | if (account_mem) | |
5345 | io_unaccount_mem(user, ring_pages(p->sq_entries, | |
5346 | p->cq_entries)); | |
5347 | free_uid(user); | |
5348 | return -ENOMEM; | |
5349 | } | |
5350 | ctx->compat = in_compat_syscall(); | |
5351 | ctx->account_mem = account_mem; | |
5352 | ctx->user = user; | |
0b8c0ec7 | 5353 | ctx->creds = get_current_cred(); |
2b188cc1 JA |
5354 | |
5355 | ret = io_allocate_scq_urings(ctx, p); | |
5356 | if (ret) | |
5357 | goto err; | |
5358 | ||
6c271ce2 | 5359 | ret = io_sq_offload_start(ctx, p); |
2b188cc1 JA |
5360 | if (ret) |
5361 | goto err; | |
5362 | ||
2b188cc1 | 5363 | memset(&p->sq_off, 0, sizeof(p->sq_off)); |
75b28aff HV |
5364 | p->sq_off.head = offsetof(struct io_rings, sq.head); |
5365 | p->sq_off.tail = offsetof(struct io_rings, sq.tail); | |
5366 | p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask); | |
5367 | p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries); | |
5368 | p->sq_off.flags = offsetof(struct io_rings, sq_flags); | |
5369 | p->sq_off.dropped = offsetof(struct io_rings, sq_dropped); | |
5370 | p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings; | |
2b188cc1 JA |
5371 | |
5372 | memset(&p->cq_off, 0, sizeof(p->cq_off)); | |
75b28aff HV |
5373 | p->cq_off.head = offsetof(struct io_rings, cq.head); |
5374 | p->cq_off.tail = offsetof(struct io_rings, cq.tail); | |
5375 | p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask); | |
5376 | p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries); | |
5377 | p->cq_off.overflow = offsetof(struct io_rings, cq_overflow); | |
5378 | p->cq_off.cqes = offsetof(struct io_rings, cqes); | |
ac90f249 | 5379 | |
044c1ab3 JA |
5380 | /* |
5381 | * Install ring fd as the very last thing, so we don't risk someone | |
5382 | * having closed it before we finish setup | |
5383 | */ | |
5384 | ret = io_uring_get_fd(ctx); | |
5385 | if (ret < 0) | |
5386 | goto err; | |
5387 | ||
da8c9690 JA |
5388 | p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP | |
5389 | IORING_FEAT_SUBMIT_STABLE; | |
c826bd7a | 5390 | trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); |
2b188cc1 JA |
5391 | return ret; |
5392 | err: | |
5393 | io_ring_ctx_wait_and_kill(ctx); | |
5394 | return ret; | |
5395 | } | |
5396 | ||
5397 | /* | |
5398 | * Sets up an aio uring context, and returns the fd. Applications asks for a | |
5399 | * ring size, we return the actual sq/cq ring sizes (among other things) in the | |
5400 | * params structure passed in. | |
5401 | */ | |
5402 | static long io_uring_setup(u32 entries, struct io_uring_params __user *params) | |
5403 | { | |
5404 | struct io_uring_params p; | |
5405 | long ret; | |
5406 | int i; | |
5407 | ||
5408 | if (copy_from_user(&p, params, sizeof(p))) | |
5409 | return -EFAULT; | |
5410 | for (i = 0; i < ARRAY_SIZE(p.resv); i++) { | |
5411 | if (p.resv[i]) | |
5412 | return -EINVAL; | |
5413 | } | |
5414 | ||
6c271ce2 | 5415 | if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL | |
33a107f0 | 5416 | IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE)) |
2b188cc1 JA |
5417 | return -EINVAL; |
5418 | ||
5419 | ret = io_uring_create(entries, &p); | |
5420 | if (ret < 0) | |
5421 | return ret; | |
5422 | ||
5423 | if (copy_to_user(params, &p, sizeof(p))) | |
5424 | return -EFAULT; | |
5425 | ||
5426 | return ret; | |
5427 | } | |
5428 | ||
5429 | SYSCALL_DEFINE2(io_uring_setup, u32, entries, | |
5430 | struct io_uring_params __user *, params) | |
5431 | { | |
5432 | return io_uring_setup(entries, params); | |
5433 | } | |
5434 | ||
edafccee JA |
5435 | static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, |
5436 | void __user *arg, unsigned nr_args) | |
b19062a5 JA |
5437 | __releases(ctx->uring_lock) |
5438 | __acquires(ctx->uring_lock) | |
edafccee JA |
5439 | { |
5440 | int ret; | |
5441 | ||
35fa71a0 JA |
5442 | /* |
5443 | * We're inside the ring mutex, if the ref is already dying, then | |
5444 | * someone else killed the ctx or is already going through | |
5445 | * io_uring_register(). | |
5446 | */ | |
5447 | if (percpu_ref_is_dying(&ctx->refs)) | |
5448 | return -ENXIO; | |
5449 | ||
edafccee | 5450 | percpu_ref_kill(&ctx->refs); |
b19062a5 JA |
5451 | |
5452 | /* | |
5453 | * Drop uring mutex before waiting for references to exit. If another | |
5454 | * thread is currently inside io_uring_enter() it might need to grab | |
5455 | * the uring_lock to make progress. If we hold it here across the drain | |
5456 | * wait, then we can deadlock. It's safe to drop the mutex here, since | |
5457 | * no new references will come in after we've killed the percpu ref. | |
5458 | */ | |
5459 | mutex_unlock(&ctx->uring_lock); | |
206aefde | 5460 | wait_for_completion(&ctx->completions[0]); |
b19062a5 | 5461 | mutex_lock(&ctx->uring_lock); |
edafccee JA |
5462 | |
5463 | switch (opcode) { | |
5464 | case IORING_REGISTER_BUFFERS: | |
5465 | ret = io_sqe_buffer_register(ctx, arg, nr_args); | |
5466 | break; | |
5467 | case IORING_UNREGISTER_BUFFERS: | |
5468 | ret = -EINVAL; | |
5469 | if (arg || nr_args) | |
5470 | break; | |
5471 | ret = io_sqe_buffer_unregister(ctx); | |
5472 | break; | |
6b06314c JA |
5473 | case IORING_REGISTER_FILES: |
5474 | ret = io_sqe_files_register(ctx, arg, nr_args); | |
5475 | break; | |
5476 | case IORING_UNREGISTER_FILES: | |
5477 | ret = -EINVAL; | |
5478 | if (arg || nr_args) | |
5479 | break; | |
5480 | ret = io_sqe_files_unregister(ctx); | |
5481 | break; | |
c3a31e60 JA |
5482 | case IORING_REGISTER_FILES_UPDATE: |
5483 | ret = io_sqe_files_update(ctx, arg, nr_args); | |
5484 | break; | |
9b402849 JA |
5485 | case IORING_REGISTER_EVENTFD: |
5486 | ret = -EINVAL; | |
5487 | if (nr_args != 1) | |
5488 | break; | |
5489 | ret = io_eventfd_register(ctx, arg); | |
5490 | break; | |
5491 | case IORING_UNREGISTER_EVENTFD: | |
5492 | ret = -EINVAL; | |
5493 | if (arg || nr_args) | |
5494 | break; | |
5495 | ret = io_eventfd_unregister(ctx); | |
5496 | break; | |
edafccee JA |
5497 | default: |
5498 | ret = -EINVAL; | |
5499 | break; | |
5500 | } | |
5501 | ||
5502 | /* bring the ctx back to life */ | |
206aefde | 5503 | reinit_completion(&ctx->completions[0]); |
edafccee JA |
5504 | percpu_ref_reinit(&ctx->refs); |
5505 | return ret; | |
5506 | } | |
5507 | ||
5508 | SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, | |
5509 | void __user *, arg, unsigned int, nr_args) | |
5510 | { | |
5511 | struct io_ring_ctx *ctx; | |
5512 | long ret = -EBADF; | |
5513 | struct fd f; | |
5514 | ||
5515 | f = fdget(fd); | |
5516 | if (!f.file) | |
5517 | return -EBADF; | |
5518 | ||
5519 | ret = -EOPNOTSUPP; | |
5520 | if (f.file->f_op != &io_uring_fops) | |
5521 | goto out_fput; | |
5522 | ||
5523 | ctx = f.file->private_data; | |
5524 | ||
5525 | mutex_lock(&ctx->uring_lock); | |
5526 | ret = __io_uring_register(ctx, opcode, arg, nr_args); | |
5527 | mutex_unlock(&ctx->uring_lock); | |
c826bd7a DD |
5528 | trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs, |
5529 | ctx->cq_ev_fd != NULL, ret); | |
edafccee JA |
5530 | out_fput: |
5531 | fdput(f); | |
5532 | return ret; | |
5533 | } | |
5534 | ||
2b188cc1 JA |
5535 | static int __init io_uring_init(void) |
5536 | { | |
5537 | req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC); | |
5538 | return 0; | |
5539 | }; | |
5540 | __initcall(io_uring_init); |