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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> | |
59 | #include <linux/workqueue.h> | |
6c271ce2 | 60 | #include <linux/kthread.h> |
2b188cc1 | 61 | #include <linux/blkdev.h> |
edafccee | 62 | #include <linux/bvec.h> |
2b188cc1 JA |
63 | #include <linux/net.h> |
64 | #include <net/sock.h> | |
65 | #include <net/af_unix.h> | |
6b06314c | 66 | #include <net/scm.h> |
2b188cc1 JA |
67 | #include <linux/anon_inodes.h> |
68 | #include <linux/sched/mm.h> | |
69 | #include <linux/uaccess.h> | |
70 | #include <linux/nospec.h> | |
edafccee JA |
71 | #include <linux/sizes.h> |
72 | #include <linux/hugetlb.h> | |
2b188cc1 JA |
73 | |
74 | #include <uapi/linux/io_uring.h> | |
75 | ||
76 | #include "internal.h" | |
77 | ||
78 | #define IORING_MAX_ENTRIES 4096 | |
6b06314c | 79 | #define IORING_MAX_FIXED_FILES 1024 |
2b188cc1 JA |
80 | |
81 | struct io_uring { | |
82 | u32 head ____cacheline_aligned_in_smp; | |
83 | u32 tail ____cacheline_aligned_in_smp; | |
84 | }; | |
85 | ||
1e84b97b | 86 | /* |
75b28aff HV |
87 | * This data is shared with the application through the mmap at offsets |
88 | * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING. | |
1e84b97b SB |
89 | * |
90 | * The offsets to the member fields are published through struct | |
91 | * io_sqring_offsets when calling io_uring_setup. | |
92 | */ | |
75b28aff | 93 | struct io_rings { |
1e84b97b SB |
94 | /* |
95 | * Head and tail offsets into the ring; the offsets need to be | |
96 | * masked to get valid indices. | |
97 | * | |
75b28aff HV |
98 | * The kernel controls head of the sq ring and the tail of the cq ring, |
99 | * and the application controls tail of the sq ring and the head of the | |
100 | * cq ring. | |
1e84b97b | 101 | */ |
75b28aff | 102 | struct io_uring sq, cq; |
1e84b97b | 103 | /* |
75b28aff | 104 | * Bitmasks to apply to head and tail offsets (constant, equals |
1e84b97b SB |
105 | * ring_entries - 1) |
106 | */ | |
75b28aff HV |
107 | u32 sq_ring_mask, cq_ring_mask; |
108 | /* Ring sizes (constant, power of 2) */ | |
109 | u32 sq_ring_entries, cq_ring_entries; | |
1e84b97b SB |
110 | /* |
111 | * Number of invalid entries dropped by the kernel due to | |
112 | * invalid index stored in array | |
113 | * | |
114 | * Written by the kernel, shouldn't be modified by the | |
115 | * application (i.e. get number of "new events" by comparing to | |
116 | * cached value). | |
117 | * | |
118 | * After a new SQ head value was read by the application this | |
119 | * counter includes all submissions that were dropped reaching | |
120 | * the new SQ head (and possibly more). | |
121 | */ | |
75b28aff | 122 | u32 sq_dropped; |
1e84b97b SB |
123 | /* |
124 | * Runtime flags | |
125 | * | |
126 | * Written by the kernel, shouldn't be modified by the | |
127 | * application. | |
128 | * | |
129 | * The application needs a full memory barrier before checking | |
130 | * for IORING_SQ_NEED_WAKEUP after updating the sq tail. | |
131 | */ | |
75b28aff | 132 | u32 sq_flags; |
1e84b97b SB |
133 | /* |
134 | * Number of completion events lost because the queue was full; | |
135 | * this should be avoided by the application by making sure | |
136 | * there are not more requests pending thatn there is space in | |
137 | * the completion queue. | |
138 | * | |
139 | * Written by the kernel, shouldn't be modified by the | |
140 | * application (i.e. get number of "new events" by comparing to | |
141 | * cached value). | |
142 | * | |
143 | * As completion events come in out of order this counter is not | |
144 | * ordered with any other data. | |
145 | */ | |
75b28aff | 146 | u32 cq_overflow; |
1e84b97b SB |
147 | /* |
148 | * Ring buffer of completion events. | |
149 | * | |
150 | * The kernel writes completion events fresh every time they are | |
151 | * produced, so the application is allowed to modify pending | |
152 | * entries. | |
153 | */ | |
75b28aff | 154 | struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp; |
2b188cc1 JA |
155 | }; |
156 | ||
edafccee JA |
157 | struct io_mapped_ubuf { |
158 | u64 ubuf; | |
159 | size_t len; | |
160 | struct bio_vec *bvec; | |
161 | unsigned int nr_bvecs; | |
162 | }; | |
163 | ||
31b51510 JA |
164 | struct async_list { |
165 | spinlock_t lock; | |
166 | atomic_t cnt; | |
167 | struct list_head list; | |
168 | ||
169 | struct file *file; | |
6d5d5ac5 | 170 | off_t io_start; |
9310a7ba | 171 | size_t io_len; |
31b51510 JA |
172 | }; |
173 | ||
2b188cc1 JA |
174 | struct io_ring_ctx { |
175 | struct { | |
176 | struct percpu_ref refs; | |
177 | } ____cacheline_aligned_in_smp; | |
178 | ||
179 | struct { | |
180 | unsigned int flags; | |
181 | bool compat; | |
182 | bool account_mem; | |
183 | ||
75b28aff HV |
184 | /* |
185 | * Ring buffer of indices into array of io_uring_sqe, which is | |
186 | * mmapped by the application using the IORING_OFF_SQES offset. | |
187 | * | |
188 | * This indirection could e.g. be used to assign fixed | |
189 | * io_uring_sqe entries to operations and only submit them to | |
190 | * the queue when needed. | |
191 | * | |
192 | * The kernel modifies neither the indices array nor the entries | |
193 | * array. | |
194 | */ | |
195 | u32 *sq_array; | |
2b188cc1 JA |
196 | unsigned cached_sq_head; |
197 | unsigned sq_entries; | |
198 | unsigned sq_mask; | |
6c271ce2 | 199 | unsigned sq_thread_idle; |
2b188cc1 | 200 | struct io_uring_sqe *sq_sqes; |
de0617e4 JA |
201 | |
202 | struct list_head defer_list; | |
2b188cc1 JA |
203 | } ____cacheline_aligned_in_smp; |
204 | ||
205 | /* IO offload */ | |
54a91f3b | 206 | struct workqueue_struct *sqo_wq[2]; |
6c271ce2 | 207 | struct task_struct *sqo_thread; /* if using sq thread polling */ |
2b188cc1 | 208 | struct mm_struct *sqo_mm; |
6c271ce2 | 209 | wait_queue_head_t sqo_wait; |
a4c0b3de | 210 | struct completion sqo_thread_started; |
2b188cc1 JA |
211 | |
212 | struct { | |
2b188cc1 JA |
213 | unsigned cached_cq_tail; |
214 | unsigned cq_entries; | |
215 | unsigned cq_mask; | |
216 | struct wait_queue_head cq_wait; | |
217 | struct fasync_struct *cq_fasync; | |
9b402849 | 218 | struct eventfd_ctx *cq_ev_fd; |
2b188cc1 JA |
219 | } ____cacheline_aligned_in_smp; |
220 | ||
75b28aff HV |
221 | struct io_rings *rings; |
222 | ||
6b06314c JA |
223 | /* |
224 | * If used, fixed file set. Writers must ensure that ->refs is dead, | |
225 | * readers must ensure that ->refs is alive as long as the file* is | |
226 | * used. Only updated through io_uring_register(2). | |
227 | */ | |
228 | struct file **user_files; | |
229 | unsigned nr_user_files; | |
230 | ||
edafccee JA |
231 | /* if used, fixed mapped user buffers */ |
232 | unsigned nr_user_bufs; | |
233 | struct io_mapped_ubuf *user_bufs; | |
234 | ||
2b188cc1 JA |
235 | struct user_struct *user; |
236 | ||
237 | struct completion ctx_done; | |
238 | ||
239 | struct { | |
240 | struct mutex uring_lock; | |
241 | wait_queue_head_t wait; | |
242 | } ____cacheline_aligned_in_smp; | |
243 | ||
244 | struct { | |
245 | spinlock_t completion_lock; | |
def596e9 JA |
246 | bool poll_multi_file; |
247 | /* | |
248 | * ->poll_list is protected by the ctx->uring_lock for | |
249 | * io_uring instances that don't use IORING_SETUP_SQPOLL. | |
250 | * For SQPOLL, only the single threaded io_sq_thread() will | |
251 | * manipulate the list, hence no extra locking is needed there. | |
252 | */ | |
253 | struct list_head poll_list; | |
221c5eb2 | 254 | struct list_head cancel_list; |
2b188cc1 JA |
255 | } ____cacheline_aligned_in_smp; |
256 | ||
31b51510 JA |
257 | struct async_list pending_async[2]; |
258 | ||
2b188cc1 JA |
259 | #if defined(CONFIG_UNIX) |
260 | struct socket *ring_sock; | |
261 | #endif | |
262 | }; | |
263 | ||
264 | struct sqe_submit { | |
265 | const struct io_uring_sqe *sqe; | |
266 | unsigned short index; | |
8776f3fa | 267 | u32 sequence; |
2b188cc1 | 268 | bool has_user; |
def596e9 | 269 | bool needs_lock; |
6c271ce2 | 270 | bool needs_fixed_file; |
2b188cc1 JA |
271 | }; |
272 | ||
09bb8394 JA |
273 | /* |
274 | * First field must be the file pointer in all the | |
275 | * iocb unions! See also 'struct kiocb' in <linux/fs.h> | |
276 | */ | |
221c5eb2 JA |
277 | struct io_poll_iocb { |
278 | struct file *file; | |
279 | struct wait_queue_head *head; | |
280 | __poll_t events; | |
8c838788 | 281 | bool done; |
221c5eb2 JA |
282 | bool canceled; |
283 | struct wait_queue_entry wait; | |
284 | }; | |
285 | ||
09bb8394 JA |
286 | /* |
287 | * NOTE! Each of the iocb union members has the file pointer | |
288 | * as the first entry in their struct definition. So you can | |
289 | * access the file pointer through any of the sub-structs, | |
290 | * or directly as just 'ki_filp' in this struct. | |
291 | */ | |
2b188cc1 | 292 | struct io_kiocb { |
221c5eb2 | 293 | union { |
09bb8394 | 294 | struct file *file; |
221c5eb2 JA |
295 | struct kiocb rw; |
296 | struct io_poll_iocb poll; | |
297 | }; | |
2b188cc1 JA |
298 | |
299 | struct sqe_submit submit; | |
300 | ||
301 | struct io_ring_ctx *ctx; | |
302 | struct list_head list; | |
9e645e11 | 303 | struct list_head link_list; |
2b188cc1 | 304 | unsigned int flags; |
c16361c1 | 305 | refcount_t refs; |
8449eeda | 306 | #define REQ_F_NOWAIT 1 /* must not punt to workers */ |
def596e9 | 307 | #define REQ_F_IOPOLL_COMPLETED 2 /* polled IO has completed */ |
6b06314c | 308 | #define REQ_F_FIXED_FILE 4 /* ctx owns file */ |
31b51510 | 309 | #define REQ_F_SEQ_PREV 8 /* sequential with previous */ |
e2033e33 SB |
310 | #define REQ_F_IO_DRAIN 16 /* drain existing IO first */ |
311 | #define REQ_F_IO_DRAINED 32 /* drain done */ | |
9e645e11 | 312 | #define REQ_F_LINK 64 /* linked sqes */ |
f7b76ac9 ZL |
313 | #define REQ_F_LINK_DONE 128 /* linked sqes done */ |
314 | #define REQ_F_FAIL_LINK 256 /* fail rest of links */ | |
4fe2c963 | 315 | #define REQ_F_SHADOW_DRAIN 512 /* link-drain shadow req */ |
2b188cc1 | 316 | u64 user_data; |
9e645e11 | 317 | u32 result; |
de0617e4 | 318 | u32 sequence; |
2b188cc1 JA |
319 | |
320 | struct work_struct work; | |
321 | }; | |
322 | ||
323 | #define IO_PLUG_THRESHOLD 2 | |
def596e9 | 324 | #define IO_IOPOLL_BATCH 8 |
2b188cc1 | 325 | |
9a56a232 JA |
326 | struct io_submit_state { |
327 | struct blk_plug plug; | |
328 | ||
2579f913 JA |
329 | /* |
330 | * io_kiocb alloc cache | |
331 | */ | |
332 | void *reqs[IO_IOPOLL_BATCH]; | |
333 | unsigned int free_reqs; | |
334 | unsigned int cur_req; | |
335 | ||
9a56a232 JA |
336 | /* |
337 | * File reference cache | |
338 | */ | |
339 | struct file *file; | |
340 | unsigned int fd; | |
341 | unsigned int has_refs; | |
342 | unsigned int used_refs; | |
343 | unsigned int ios_left; | |
344 | }; | |
345 | ||
de0617e4 | 346 | static void io_sq_wq_submit_work(struct work_struct *work); |
4fe2c963 | 347 | static void __io_free_req(struct io_kiocb *req); |
de0617e4 | 348 | |
2b188cc1 JA |
349 | static struct kmem_cache *req_cachep; |
350 | ||
351 | static const struct file_operations io_uring_fops; | |
352 | ||
353 | struct sock *io_uring_get_socket(struct file *file) | |
354 | { | |
355 | #if defined(CONFIG_UNIX) | |
356 | if (file->f_op == &io_uring_fops) { | |
357 | struct io_ring_ctx *ctx = file->private_data; | |
358 | ||
359 | return ctx->ring_sock->sk; | |
360 | } | |
361 | #endif | |
362 | return NULL; | |
363 | } | |
364 | EXPORT_SYMBOL(io_uring_get_socket); | |
365 | ||
366 | static void io_ring_ctx_ref_free(struct percpu_ref *ref) | |
367 | { | |
368 | struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); | |
369 | ||
370 | complete(&ctx->ctx_done); | |
371 | } | |
372 | ||
373 | static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) | |
374 | { | |
375 | struct io_ring_ctx *ctx; | |
31b51510 | 376 | int i; |
2b188cc1 JA |
377 | |
378 | ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); | |
379 | if (!ctx) | |
380 | return NULL; | |
381 | ||
21482896 RG |
382 | if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, |
383 | PERCPU_REF_ALLOW_REINIT, GFP_KERNEL)) { | |
2b188cc1 JA |
384 | kfree(ctx); |
385 | return NULL; | |
386 | } | |
387 | ||
388 | ctx->flags = p->flags; | |
389 | init_waitqueue_head(&ctx->cq_wait); | |
390 | init_completion(&ctx->ctx_done); | |
a4c0b3de | 391 | init_completion(&ctx->sqo_thread_started); |
2b188cc1 JA |
392 | mutex_init(&ctx->uring_lock); |
393 | init_waitqueue_head(&ctx->wait); | |
31b51510 JA |
394 | for (i = 0; i < ARRAY_SIZE(ctx->pending_async); i++) { |
395 | spin_lock_init(&ctx->pending_async[i].lock); | |
396 | INIT_LIST_HEAD(&ctx->pending_async[i].list); | |
397 | atomic_set(&ctx->pending_async[i].cnt, 0); | |
398 | } | |
2b188cc1 | 399 | spin_lock_init(&ctx->completion_lock); |
def596e9 | 400 | INIT_LIST_HEAD(&ctx->poll_list); |
221c5eb2 | 401 | INIT_LIST_HEAD(&ctx->cancel_list); |
de0617e4 | 402 | INIT_LIST_HEAD(&ctx->defer_list); |
2b188cc1 JA |
403 | return ctx; |
404 | } | |
405 | ||
de0617e4 JA |
406 | static inline bool io_sequence_defer(struct io_ring_ctx *ctx, |
407 | struct io_kiocb *req) | |
408 | { | |
409 | if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN) | |
410 | return false; | |
411 | ||
75b28aff | 412 | return req->sequence != ctx->cached_cq_tail + ctx->rings->sq_dropped; |
de0617e4 JA |
413 | } |
414 | ||
415 | static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx) | |
416 | { | |
417 | struct io_kiocb *req; | |
418 | ||
419 | if (list_empty(&ctx->defer_list)) | |
420 | return NULL; | |
421 | ||
422 | req = list_first_entry(&ctx->defer_list, struct io_kiocb, list); | |
423 | if (!io_sequence_defer(ctx, req)) { | |
424 | list_del_init(&req->list); | |
425 | return req; | |
426 | } | |
427 | ||
428 | return NULL; | |
429 | } | |
430 | ||
431 | static void __io_commit_cqring(struct io_ring_ctx *ctx) | |
2b188cc1 | 432 | { |
75b28aff | 433 | struct io_rings *rings = ctx->rings; |
2b188cc1 | 434 | |
75b28aff | 435 | if (ctx->cached_cq_tail != READ_ONCE(rings->cq.tail)) { |
2b188cc1 | 436 | /* order cqe stores with ring update */ |
75b28aff | 437 | smp_store_release(&rings->cq.tail, ctx->cached_cq_tail); |
2b188cc1 | 438 | |
2b188cc1 JA |
439 | if (wq_has_sleeper(&ctx->cq_wait)) { |
440 | wake_up_interruptible(&ctx->cq_wait); | |
441 | kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN); | |
442 | } | |
443 | } | |
444 | } | |
445 | ||
18d9be1a JA |
446 | static inline void io_queue_async_work(struct io_ring_ctx *ctx, |
447 | struct io_kiocb *req) | |
448 | { | |
54a91f3b JA |
449 | int rw; |
450 | ||
451 | switch (req->submit.sqe->opcode) { | |
452 | case IORING_OP_WRITEV: | |
453 | case IORING_OP_WRITE_FIXED: | |
454 | rw = !(req->rw.ki_flags & IOCB_DIRECT); | |
455 | break; | |
456 | default: | |
457 | rw = 0; | |
458 | break; | |
459 | } | |
460 | ||
461 | queue_work(ctx->sqo_wq[rw], &req->work); | |
18d9be1a JA |
462 | } |
463 | ||
de0617e4 JA |
464 | static void io_commit_cqring(struct io_ring_ctx *ctx) |
465 | { | |
466 | struct io_kiocb *req; | |
467 | ||
468 | __io_commit_cqring(ctx); | |
469 | ||
470 | while ((req = io_get_deferred_req(ctx)) != NULL) { | |
4fe2c963 JL |
471 | if (req->flags & REQ_F_SHADOW_DRAIN) { |
472 | /* Just for drain, free it. */ | |
473 | __io_free_req(req); | |
474 | continue; | |
475 | } | |
de0617e4 | 476 | req->flags |= REQ_F_IO_DRAINED; |
18d9be1a | 477 | io_queue_async_work(ctx, req); |
de0617e4 JA |
478 | } |
479 | } | |
480 | ||
2b188cc1 JA |
481 | static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx) |
482 | { | |
75b28aff | 483 | struct io_rings *rings = ctx->rings; |
2b188cc1 JA |
484 | unsigned tail; |
485 | ||
486 | tail = ctx->cached_cq_tail; | |
115e12e5 SB |
487 | /* |
488 | * writes to the cq entry need to come after reading head; the | |
489 | * control dependency is enough as we're using WRITE_ONCE to | |
490 | * fill the cq entry | |
491 | */ | |
75b28aff | 492 | if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries) |
2b188cc1 JA |
493 | return NULL; |
494 | ||
495 | ctx->cached_cq_tail++; | |
75b28aff | 496 | return &rings->cqes[tail & ctx->cq_mask]; |
2b188cc1 JA |
497 | } |
498 | ||
499 | static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data, | |
c71ffb67 | 500 | long res) |
2b188cc1 JA |
501 | { |
502 | struct io_uring_cqe *cqe; | |
503 | ||
504 | /* | |
505 | * If we can't get a cq entry, userspace overflowed the | |
506 | * submission (by quite a lot). Increment the overflow count in | |
507 | * the ring. | |
508 | */ | |
509 | cqe = io_get_cqring(ctx); | |
510 | if (cqe) { | |
511 | WRITE_ONCE(cqe->user_data, ki_user_data); | |
512 | WRITE_ONCE(cqe->res, res); | |
c71ffb67 | 513 | WRITE_ONCE(cqe->flags, 0); |
2b188cc1 | 514 | } else { |
75b28aff | 515 | unsigned overflow = READ_ONCE(ctx->rings->cq_overflow); |
2b188cc1 | 516 | |
75b28aff | 517 | WRITE_ONCE(ctx->rings->cq_overflow, overflow + 1); |
2b188cc1 JA |
518 | } |
519 | } | |
520 | ||
8c838788 JA |
521 | static void io_cqring_ev_posted(struct io_ring_ctx *ctx) |
522 | { | |
523 | if (waitqueue_active(&ctx->wait)) | |
524 | wake_up(&ctx->wait); | |
525 | if (waitqueue_active(&ctx->sqo_wait)) | |
526 | wake_up(&ctx->sqo_wait); | |
9b402849 JA |
527 | if (ctx->cq_ev_fd) |
528 | eventfd_signal(ctx->cq_ev_fd, 1); | |
8c838788 JA |
529 | } |
530 | ||
531 | static void io_cqring_add_event(struct io_ring_ctx *ctx, u64 user_data, | |
c71ffb67 | 532 | long res) |
2b188cc1 JA |
533 | { |
534 | unsigned long flags; | |
535 | ||
536 | spin_lock_irqsave(&ctx->completion_lock, flags); | |
c71ffb67 | 537 | io_cqring_fill_event(ctx, user_data, res); |
2b188cc1 JA |
538 | io_commit_cqring(ctx); |
539 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
540 | ||
8c838788 | 541 | io_cqring_ev_posted(ctx); |
2b188cc1 JA |
542 | } |
543 | ||
544 | static void io_ring_drop_ctx_refs(struct io_ring_ctx *ctx, unsigned refs) | |
545 | { | |
546 | percpu_ref_put_many(&ctx->refs, refs); | |
547 | ||
548 | if (waitqueue_active(&ctx->wait)) | |
549 | wake_up(&ctx->wait); | |
550 | } | |
551 | ||
2579f913 JA |
552 | static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, |
553 | struct io_submit_state *state) | |
2b188cc1 | 554 | { |
fd6fab2c | 555 | gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; |
2b188cc1 JA |
556 | struct io_kiocb *req; |
557 | ||
558 | if (!percpu_ref_tryget(&ctx->refs)) | |
559 | return NULL; | |
560 | ||
2579f913 | 561 | if (!state) { |
fd6fab2c | 562 | req = kmem_cache_alloc(req_cachep, gfp); |
2579f913 JA |
563 | if (unlikely(!req)) |
564 | goto out; | |
565 | } else if (!state->free_reqs) { | |
566 | size_t sz; | |
567 | int ret; | |
568 | ||
569 | sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs)); | |
fd6fab2c JA |
570 | ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs); |
571 | ||
572 | /* | |
573 | * Bulk alloc is all-or-nothing. If we fail to get a batch, | |
574 | * retry single alloc to be on the safe side. | |
575 | */ | |
576 | if (unlikely(ret <= 0)) { | |
577 | state->reqs[0] = kmem_cache_alloc(req_cachep, gfp); | |
578 | if (!state->reqs[0]) | |
579 | goto out; | |
580 | ret = 1; | |
581 | } | |
2579f913 JA |
582 | state->free_reqs = ret - 1; |
583 | state->cur_req = 1; | |
584 | req = state->reqs[0]; | |
585 | } else { | |
586 | req = state->reqs[state->cur_req]; | |
587 | state->free_reqs--; | |
588 | state->cur_req++; | |
2b188cc1 JA |
589 | } |
590 | ||
60c112b0 | 591 | req->file = NULL; |
2579f913 JA |
592 | req->ctx = ctx; |
593 | req->flags = 0; | |
e65ef56d JA |
594 | /* one is dropped after submission, the other at completion */ |
595 | refcount_set(&req->refs, 2); | |
9e645e11 | 596 | req->result = 0; |
2579f913 JA |
597 | return req; |
598 | out: | |
2b188cc1 JA |
599 | io_ring_drop_ctx_refs(ctx, 1); |
600 | return NULL; | |
601 | } | |
602 | ||
def596e9 JA |
603 | static void io_free_req_many(struct io_ring_ctx *ctx, void **reqs, int *nr) |
604 | { | |
605 | if (*nr) { | |
606 | kmem_cache_free_bulk(req_cachep, *nr, reqs); | |
607 | io_ring_drop_ctx_refs(ctx, *nr); | |
608 | *nr = 0; | |
609 | } | |
610 | } | |
611 | ||
9e645e11 | 612 | static void __io_free_req(struct io_kiocb *req) |
2b188cc1 | 613 | { |
09bb8394 JA |
614 | if (req->file && !(req->flags & REQ_F_FIXED_FILE)) |
615 | fput(req->file); | |
e65ef56d JA |
616 | io_ring_drop_ctx_refs(req->ctx, 1); |
617 | kmem_cache_free(req_cachep, req); | |
618 | } | |
619 | ||
9e645e11 JA |
620 | static void io_req_link_next(struct io_kiocb *req) |
621 | { | |
622 | struct io_kiocb *nxt; | |
623 | ||
624 | /* | |
625 | * The list should never be empty when we are called here. But could | |
626 | * potentially happen if the chain is messed up, check to be on the | |
627 | * safe side. | |
628 | */ | |
629 | nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb, list); | |
630 | if (nxt) { | |
631 | list_del(&nxt->list); | |
632 | if (!list_empty(&req->link_list)) { | |
633 | INIT_LIST_HEAD(&nxt->link_list); | |
634 | list_splice(&req->link_list, &nxt->link_list); | |
635 | nxt->flags |= REQ_F_LINK; | |
636 | } | |
637 | ||
f7b76ac9 | 638 | nxt->flags |= REQ_F_LINK_DONE; |
9e645e11 | 639 | INIT_WORK(&nxt->work, io_sq_wq_submit_work); |
18d9be1a | 640 | io_queue_async_work(req->ctx, nxt); |
9e645e11 JA |
641 | } |
642 | } | |
643 | ||
644 | /* | |
645 | * Called if REQ_F_LINK is set, and we fail the head request | |
646 | */ | |
647 | static void io_fail_links(struct io_kiocb *req) | |
648 | { | |
649 | struct io_kiocb *link; | |
650 | ||
651 | while (!list_empty(&req->link_list)) { | |
652 | link = list_first_entry(&req->link_list, struct io_kiocb, list); | |
653 | list_del(&link->list); | |
654 | ||
655 | io_cqring_add_event(req->ctx, link->user_data, -ECANCELED); | |
656 | __io_free_req(link); | |
657 | } | |
658 | } | |
659 | ||
660 | static void io_free_req(struct io_kiocb *req) | |
661 | { | |
662 | /* | |
663 | * If LINK is set, we have dependent requests in this chain. If we | |
664 | * didn't fail this request, queue the first one up, moving any other | |
665 | * dependencies to the next request. In case of failure, fail the rest | |
666 | * of the chain. | |
667 | */ | |
668 | if (req->flags & REQ_F_LINK) { | |
669 | if (req->flags & REQ_F_FAIL_LINK) | |
670 | io_fail_links(req); | |
671 | else | |
672 | io_req_link_next(req); | |
673 | } | |
674 | ||
675 | __io_free_req(req); | |
676 | } | |
677 | ||
e65ef56d JA |
678 | static void io_put_req(struct io_kiocb *req) |
679 | { | |
680 | if (refcount_dec_and_test(&req->refs)) | |
681 | io_free_req(req); | |
2b188cc1 JA |
682 | } |
683 | ||
75b28aff | 684 | static unsigned io_cqring_events(struct io_rings *rings) |
a3a0e43f JA |
685 | { |
686 | /* See comment at the top of this file */ | |
687 | smp_rmb(); | |
75b28aff | 688 | return READ_ONCE(rings->cq.tail) - READ_ONCE(rings->cq.head); |
a3a0e43f JA |
689 | } |
690 | ||
def596e9 JA |
691 | /* |
692 | * Find and free completed poll iocbs | |
693 | */ | |
694 | static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, | |
695 | struct list_head *done) | |
696 | { | |
697 | void *reqs[IO_IOPOLL_BATCH]; | |
698 | struct io_kiocb *req; | |
09bb8394 | 699 | int to_free; |
def596e9 | 700 | |
09bb8394 | 701 | to_free = 0; |
def596e9 JA |
702 | while (!list_empty(done)) { |
703 | req = list_first_entry(done, struct io_kiocb, list); | |
704 | list_del(&req->list); | |
705 | ||
9e645e11 | 706 | io_cqring_fill_event(ctx, req->user_data, req->result); |
def596e9 JA |
707 | (*nr_events)++; |
708 | ||
09bb8394 JA |
709 | if (refcount_dec_and_test(&req->refs)) { |
710 | /* If we're not using fixed files, we have to pair the | |
711 | * completion part with the file put. Use regular | |
712 | * completions for those, only batch free for fixed | |
9e645e11 | 713 | * file and non-linked commands. |
09bb8394 | 714 | */ |
9e645e11 JA |
715 | if ((req->flags & (REQ_F_FIXED_FILE|REQ_F_LINK)) == |
716 | REQ_F_FIXED_FILE) { | |
09bb8394 JA |
717 | reqs[to_free++] = req; |
718 | if (to_free == ARRAY_SIZE(reqs)) | |
719 | io_free_req_many(ctx, reqs, &to_free); | |
6b06314c | 720 | } else { |
09bb8394 | 721 | io_free_req(req); |
6b06314c | 722 | } |
9a56a232 | 723 | } |
def596e9 | 724 | } |
def596e9 | 725 | |
09bb8394 | 726 | io_commit_cqring(ctx); |
def596e9 JA |
727 | io_free_req_many(ctx, reqs, &to_free); |
728 | } | |
729 | ||
730 | static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events, | |
731 | long min) | |
732 | { | |
733 | struct io_kiocb *req, *tmp; | |
734 | LIST_HEAD(done); | |
735 | bool spin; | |
736 | int ret; | |
737 | ||
738 | /* | |
739 | * Only spin for completions if we don't have multiple devices hanging | |
740 | * off our complete list, and we're under the requested amount. | |
741 | */ | |
742 | spin = !ctx->poll_multi_file && *nr_events < min; | |
743 | ||
744 | ret = 0; | |
745 | list_for_each_entry_safe(req, tmp, &ctx->poll_list, list) { | |
746 | struct kiocb *kiocb = &req->rw; | |
747 | ||
748 | /* | |
749 | * Move completed entries to our local list. If we find a | |
750 | * request that requires polling, break out and complete | |
751 | * the done list first, if we have entries there. | |
752 | */ | |
753 | if (req->flags & REQ_F_IOPOLL_COMPLETED) { | |
754 | list_move_tail(&req->list, &done); | |
755 | continue; | |
756 | } | |
757 | if (!list_empty(&done)) | |
758 | break; | |
759 | ||
760 | ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin); | |
761 | if (ret < 0) | |
762 | break; | |
763 | ||
764 | if (ret && spin) | |
765 | spin = false; | |
766 | ret = 0; | |
767 | } | |
768 | ||
769 | if (!list_empty(&done)) | |
770 | io_iopoll_complete(ctx, nr_events, &done); | |
771 | ||
772 | return ret; | |
773 | } | |
774 | ||
775 | /* | |
776 | * Poll for a mininum of 'min' events. Note that if min == 0 we consider that a | |
777 | * non-spinning poll check - we'll still enter the driver poll loop, but only | |
778 | * as a non-spinning completion check. | |
779 | */ | |
780 | static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events, | |
781 | long min) | |
782 | { | |
08f5439f | 783 | while (!list_empty(&ctx->poll_list) && !need_resched()) { |
def596e9 JA |
784 | int ret; |
785 | ||
786 | ret = io_do_iopoll(ctx, nr_events, min); | |
787 | if (ret < 0) | |
788 | return ret; | |
789 | if (!min || *nr_events >= min) | |
790 | return 0; | |
791 | } | |
792 | ||
793 | return 1; | |
794 | } | |
795 | ||
796 | /* | |
797 | * We can't just wait for polled events to come to us, we have to actively | |
798 | * find and complete them. | |
799 | */ | |
800 | static void io_iopoll_reap_events(struct io_ring_ctx *ctx) | |
801 | { | |
802 | if (!(ctx->flags & IORING_SETUP_IOPOLL)) | |
803 | return; | |
804 | ||
805 | mutex_lock(&ctx->uring_lock); | |
806 | while (!list_empty(&ctx->poll_list)) { | |
807 | unsigned int nr_events = 0; | |
808 | ||
809 | io_iopoll_getevents(ctx, &nr_events, 1); | |
08f5439f JA |
810 | |
811 | /* | |
812 | * Ensure we allow local-to-the-cpu processing to take place, | |
813 | * in this case we need to ensure that we reap all events. | |
814 | */ | |
815 | cond_resched(); | |
def596e9 JA |
816 | } |
817 | mutex_unlock(&ctx->uring_lock); | |
818 | } | |
819 | ||
820 | static int io_iopoll_check(struct io_ring_ctx *ctx, unsigned *nr_events, | |
821 | long min) | |
822 | { | |
500f9fba JA |
823 | int iters, ret = 0; |
824 | ||
825 | /* | |
826 | * We disallow the app entering submit/complete with polling, but we | |
827 | * still need to lock the ring to prevent racing with polled issue | |
828 | * that got punted to a workqueue. | |
829 | */ | |
830 | mutex_lock(&ctx->uring_lock); | |
def596e9 | 831 | |
500f9fba | 832 | iters = 0; |
def596e9 JA |
833 | do { |
834 | int tmin = 0; | |
835 | ||
a3a0e43f JA |
836 | /* |
837 | * Don't enter poll loop if we already have events pending. | |
838 | * If we do, we can potentially be spinning for commands that | |
839 | * already triggered a CQE (eg in error). | |
840 | */ | |
75b28aff | 841 | if (io_cqring_events(ctx->rings)) |
a3a0e43f JA |
842 | break; |
843 | ||
500f9fba JA |
844 | /* |
845 | * If a submit got punted to a workqueue, we can have the | |
846 | * application entering polling for a command before it gets | |
847 | * issued. That app will hold the uring_lock for the duration | |
848 | * of the poll right here, so we need to take a breather every | |
849 | * now and then to ensure that the issue has a chance to add | |
850 | * the poll to the issued list. Otherwise we can spin here | |
851 | * forever, while the workqueue is stuck trying to acquire the | |
852 | * very same mutex. | |
853 | */ | |
854 | if (!(++iters & 7)) { | |
855 | mutex_unlock(&ctx->uring_lock); | |
856 | mutex_lock(&ctx->uring_lock); | |
857 | } | |
858 | ||
def596e9 JA |
859 | if (*nr_events < min) |
860 | tmin = min - *nr_events; | |
861 | ||
862 | ret = io_iopoll_getevents(ctx, nr_events, tmin); | |
863 | if (ret <= 0) | |
864 | break; | |
865 | ret = 0; | |
866 | } while (min && !*nr_events && !need_resched()); | |
867 | ||
500f9fba | 868 | mutex_unlock(&ctx->uring_lock); |
def596e9 JA |
869 | return ret; |
870 | } | |
871 | ||
2b188cc1 JA |
872 | static void kiocb_end_write(struct kiocb *kiocb) |
873 | { | |
874 | if (kiocb->ki_flags & IOCB_WRITE) { | |
875 | struct inode *inode = file_inode(kiocb->ki_filp); | |
876 | ||
877 | /* | |
878 | * Tell lockdep we inherited freeze protection from submission | |
879 | * thread. | |
880 | */ | |
881 | if (S_ISREG(inode->i_mode)) | |
882 | __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE); | |
883 | file_end_write(kiocb->ki_filp); | |
884 | } | |
885 | } | |
886 | ||
887 | static void io_complete_rw(struct kiocb *kiocb, long res, long res2) | |
888 | { | |
889 | struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); | |
890 | ||
891 | kiocb_end_write(kiocb); | |
892 | ||
9e645e11 JA |
893 | if ((req->flags & REQ_F_LINK) && res != req->result) |
894 | req->flags |= REQ_F_FAIL_LINK; | |
c71ffb67 | 895 | io_cqring_add_event(req->ctx, req->user_data, res); |
e65ef56d | 896 | io_put_req(req); |
2b188cc1 JA |
897 | } |
898 | ||
def596e9 JA |
899 | static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) |
900 | { | |
901 | struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw); | |
902 | ||
903 | kiocb_end_write(kiocb); | |
904 | ||
9e645e11 JA |
905 | if ((req->flags & REQ_F_LINK) && res != req->result) |
906 | req->flags |= REQ_F_FAIL_LINK; | |
907 | req->result = res; | |
def596e9 JA |
908 | if (res != -EAGAIN) |
909 | req->flags |= REQ_F_IOPOLL_COMPLETED; | |
910 | } | |
911 | ||
912 | /* | |
913 | * After the iocb has been issued, it's safe to be found on the poll list. | |
914 | * Adding the kiocb to the list AFTER submission ensures that we don't | |
915 | * find it from a io_iopoll_getevents() thread before the issuer is done | |
916 | * accessing the kiocb cookie. | |
917 | */ | |
918 | static void io_iopoll_req_issued(struct io_kiocb *req) | |
919 | { | |
920 | struct io_ring_ctx *ctx = req->ctx; | |
921 | ||
922 | /* | |
923 | * Track whether we have multiple files in our lists. This will impact | |
924 | * how we do polling eventually, not spinning if we're on potentially | |
925 | * different devices. | |
926 | */ | |
927 | if (list_empty(&ctx->poll_list)) { | |
928 | ctx->poll_multi_file = false; | |
929 | } else if (!ctx->poll_multi_file) { | |
930 | struct io_kiocb *list_req; | |
931 | ||
932 | list_req = list_first_entry(&ctx->poll_list, struct io_kiocb, | |
933 | list); | |
934 | if (list_req->rw.ki_filp != req->rw.ki_filp) | |
935 | ctx->poll_multi_file = true; | |
936 | } | |
937 | ||
938 | /* | |
939 | * For fast devices, IO may have already completed. If it has, add | |
940 | * it to the front so we find it first. | |
941 | */ | |
942 | if (req->flags & REQ_F_IOPOLL_COMPLETED) | |
943 | list_add(&req->list, &ctx->poll_list); | |
944 | else | |
945 | list_add_tail(&req->list, &ctx->poll_list); | |
946 | } | |
947 | ||
3d6770fb | 948 | static void io_file_put(struct io_submit_state *state) |
9a56a232 | 949 | { |
3d6770fb | 950 | if (state->file) { |
9a56a232 JA |
951 | int diff = state->has_refs - state->used_refs; |
952 | ||
953 | if (diff) | |
954 | fput_many(state->file, diff); | |
955 | state->file = NULL; | |
956 | } | |
957 | } | |
958 | ||
959 | /* | |
960 | * Get as many references to a file as we have IOs left in this submission, | |
961 | * assuming most submissions are for one file, or at least that each file | |
962 | * has more than one submission. | |
963 | */ | |
964 | static struct file *io_file_get(struct io_submit_state *state, int fd) | |
965 | { | |
966 | if (!state) | |
967 | return fget(fd); | |
968 | ||
969 | if (state->file) { | |
970 | if (state->fd == fd) { | |
971 | state->used_refs++; | |
972 | state->ios_left--; | |
973 | return state->file; | |
974 | } | |
3d6770fb | 975 | io_file_put(state); |
9a56a232 JA |
976 | } |
977 | state->file = fget_many(fd, state->ios_left); | |
978 | if (!state->file) | |
979 | return NULL; | |
980 | ||
981 | state->fd = fd; | |
982 | state->has_refs = state->ios_left; | |
983 | state->used_refs = 1; | |
984 | state->ios_left--; | |
985 | return state->file; | |
986 | } | |
987 | ||
2b188cc1 JA |
988 | /* |
989 | * If we tracked the file through the SCM inflight mechanism, we could support | |
990 | * any file. For now, just ensure that anything potentially problematic is done | |
991 | * inline. | |
992 | */ | |
993 | static bool io_file_supports_async(struct file *file) | |
994 | { | |
995 | umode_t mode = file_inode(file)->i_mode; | |
996 | ||
997 | if (S_ISBLK(mode) || S_ISCHR(mode)) | |
998 | return true; | |
999 | if (S_ISREG(mode) && file->f_op != &io_uring_fops) | |
1000 | return true; | |
1001 | ||
1002 | return false; | |
1003 | } | |
1004 | ||
6c271ce2 | 1005 | static int io_prep_rw(struct io_kiocb *req, const struct sqe_submit *s, |
8358e3a8 | 1006 | bool force_nonblock) |
2b188cc1 | 1007 | { |
6c271ce2 | 1008 | const struct io_uring_sqe *sqe = s->sqe; |
def596e9 | 1009 | struct io_ring_ctx *ctx = req->ctx; |
2b188cc1 | 1010 | struct kiocb *kiocb = &req->rw; |
09bb8394 JA |
1011 | unsigned ioprio; |
1012 | int ret; | |
2b188cc1 | 1013 | |
09bb8394 JA |
1014 | if (!req->file) |
1015 | return -EBADF; | |
2b188cc1 | 1016 | |
09bb8394 JA |
1017 | if (force_nonblock && !io_file_supports_async(req->file)) |
1018 | force_nonblock = false; | |
6b06314c | 1019 | |
2b188cc1 JA |
1020 | kiocb->ki_pos = READ_ONCE(sqe->off); |
1021 | kiocb->ki_flags = iocb_flags(kiocb->ki_filp); | |
1022 | kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); | |
1023 | ||
1024 | ioprio = READ_ONCE(sqe->ioprio); | |
1025 | if (ioprio) { | |
1026 | ret = ioprio_check_cap(ioprio); | |
1027 | if (ret) | |
09bb8394 | 1028 | return ret; |
2b188cc1 JA |
1029 | |
1030 | kiocb->ki_ioprio = ioprio; | |
1031 | } else | |
1032 | kiocb->ki_ioprio = get_current_ioprio(); | |
1033 | ||
1034 | ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags)); | |
1035 | if (unlikely(ret)) | |
09bb8394 | 1036 | return ret; |
8449eeda SB |
1037 | |
1038 | /* don't allow async punt if RWF_NOWAIT was requested */ | |
1039 | if (kiocb->ki_flags & IOCB_NOWAIT) | |
1040 | req->flags |= REQ_F_NOWAIT; | |
1041 | ||
1042 | if (force_nonblock) | |
2b188cc1 | 1043 | kiocb->ki_flags |= IOCB_NOWAIT; |
8449eeda | 1044 | |
def596e9 | 1045 | if (ctx->flags & IORING_SETUP_IOPOLL) { |
def596e9 JA |
1046 | if (!(kiocb->ki_flags & IOCB_DIRECT) || |
1047 | !kiocb->ki_filp->f_op->iopoll) | |
09bb8394 | 1048 | return -EOPNOTSUPP; |
2b188cc1 | 1049 | |
def596e9 JA |
1050 | kiocb->ki_flags |= IOCB_HIPRI; |
1051 | kiocb->ki_complete = io_complete_rw_iopoll; | |
1052 | } else { | |
09bb8394 JA |
1053 | if (kiocb->ki_flags & IOCB_HIPRI) |
1054 | return -EINVAL; | |
def596e9 JA |
1055 | kiocb->ki_complete = io_complete_rw; |
1056 | } | |
2b188cc1 | 1057 | return 0; |
2b188cc1 JA |
1058 | } |
1059 | ||
1060 | static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) | |
1061 | { | |
1062 | switch (ret) { | |
1063 | case -EIOCBQUEUED: | |
1064 | break; | |
1065 | case -ERESTARTSYS: | |
1066 | case -ERESTARTNOINTR: | |
1067 | case -ERESTARTNOHAND: | |
1068 | case -ERESTART_RESTARTBLOCK: | |
1069 | /* | |
1070 | * We can't just restart the syscall, since previously | |
1071 | * submitted sqes may already be in progress. Just fail this | |
1072 | * IO with EINTR. | |
1073 | */ | |
1074 | ret = -EINTR; | |
1075 | /* fall through */ | |
1076 | default: | |
1077 | kiocb->ki_complete(kiocb, ret, 0); | |
1078 | } | |
1079 | } | |
1080 | ||
edafccee JA |
1081 | static int io_import_fixed(struct io_ring_ctx *ctx, int rw, |
1082 | const struct io_uring_sqe *sqe, | |
1083 | struct iov_iter *iter) | |
1084 | { | |
1085 | size_t len = READ_ONCE(sqe->len); | |
1086 | struct io_mapped_ubuf *imu; | |
1087 | unsigned index, buf_index; | |
1088 | size_t offset; | |
1089 | u64 buf_addr; | |
1090 | ||
1091 | /* attempt to use fixed buffers without having provided iovecs */ | |
1092 | if (unlikely(!ctx->user_bufs)) | |
1093 | return -EFAULT; | |
1094 | ||
1095 | buf_index = READ_ONCE(sqe->buf_index); | |
1096 | if (unlikely(buf_index >= ctx->nr_user_bufs)) | |
1097 | return -EFAULT; | |
1098 | ||
1099 | index = array_index_nospec(buf_index, ctx->nr_user_bufs); | |
1100 | imu = &ctx->user_bufs[index]; | |
1101 | buf_addr = READ_ONCE(sqe->addr); | |
1102 | ||
1103 | /* overflow */ | |
1104 | if (buf_addr + len < buf_addr) | |
1105 | return -EFAULT; | |
1106 | /* not inside the mapped region */ | |
1107 | if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len) | |
1108 | return -EFAULT; | |
1109 | ||
1110 | /* | |
1111 | * May not be a start of buffer, set size appropriately | |
1112 | * and advance us to the beginning. | |
1113 | */ | |
1114 | offset = buf_addr - imu->ubuf; | |
1115 | iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len); | |
bd11b3a3 JA |
1116 | |
1117 | if (offset) { | |
1118 | /* | |
1119 | * Don't use iov_iter_advance() here, as it's really slow for | |
1120 | * using the latter parts of a big fixed buffer - it iterates | |
1121 | * over each segment manually. We can cheat a bit here, because | |
1122 | * we know that: | |
1123 | * | |
1124 | * 1) it's a BVEC iter, we set it up | |
1125 | * 2) all bvecs are PAGE_SIZE in size, except potentially the | |
1126 | * first and last bvec | |
1127 | * | |
1128 | * So just find our index, and adjust the iterator afterwards. | |
1129 | * If the offset is within the first bvec (or the whole first | |
1130 | * bvec, just use iov_iter_advance(). This makes it easier | |
1131 | * since we can just skip the first segment, which may not | |
1132 | * be PAGE_SIZE aligned. | |
1133 | */ | |
1134 | const struct bio_vec *bvec = imu->bvec; | |
1135 | ||
1136 | if (offset <= bvec->bv_len) { | |
1137 | iov_iter_advance(iter, offset); | |
1138 | } else { | |
1139 | unsigned long seg_skip; | |
1140 | ||
1141 | /* skip first vec */ | |
1142 | offset -= bvec->bv_len; | |
1143 | seg_skip = 1 + (offset >> PAGE_SHIFT); | |
1144 | ||
1145 | iter->bvec = bvec + seg_skip; | |
1146 | iter->nr_segs -= seg_skip; | |
99c79f66 | 1147 | iter->count -= bvec->bv_len + offset; |
bd11b3a3 | 1148 | iter->iov_offset = offset & ~PAGE_MASK; |
bd11b3a3 JA |
1149 | } |
1150 | } | |
1151 | ||
edafccee JA |
1152 | return 0; |
1153 | } | |
1154 | ||
87e5e6da JA |
1155 | static ssize_t io_import_iovec(struct io_ring_ctx *ctx, int rw, |
1156 | const struct sqe_submit *s, struct iovec **iovec, | |
1157 | struct iov_iter *iter) | |
2b188cc1 JA |
1158 | { |
1159 | const struct io_uring_sqe *sqe = s->sqe; | |
1160 | void __user *buf = u64_to_user_ptr(READ_ONCE(sqe->addr)); | |
1161 | size_t sqe_len = READ_ONCE(sqe->len); | |
edafccee JA |
1162 | u8 opcode; |
1163 | ||
1164 | /* | |
1165 | * We're reading ->opcode for the second time, but the first read | |
1166 | * doesn't care whether it's _FIXED or not, so it doesn't matter | |
1167 | * whether ->opcode changes concurrently. The first read does care | |
1168 | * about whether it is a READ or a WRITE, so we don't trust this read | |
1169 | * for that purpose and instead let the caller pass in the read/write | |
1170 | * flag. | |
1171 | */ | |
1172 | opcode = READ_ONCE(sqe->opcode); | |
1173 | if (opcode == IORING_OP_READ_FIXED || | |
1174 | opcode == IORING_OP_WRITE_FIXED) { | |
87e5e6da | 1175 | ssize_t ret = io_import_fixed(ctx, rw, sqe, iter); |
edafccee JA |
1176 | *iovec = NULL; |
1177 | return ret; | |
1178 | } | |
2b188cc1 JA |
1179 | |
1180 | if (!s->has_user) | |
1181 | return -EFAULT; | |
1182 | ||
1183 | #ifdef CONFIG_COMPAT | |
1184 | if (ctx->compat) | |
1185 | return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV, | |
1186 | iovec, iter); | |
1187 | #endif | |
1188 | ||
1189 | return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter); | |
1190 | } | |
1191 | ||
6d5d5ac5 JA |
1192 | static inline bool io_should_merge(struct async_list *al, struct kiocb *kiocb) |
1193 | { | |
1194 | if (al->file == kiocb->ki_filp) { | |
1195 | off_t start, end; | |
1196 | ||
1197 | /* | |
1198 | * Allow merging if we're anywhere in the range of the same | |
1199 | * page. Generally this happens for sub-page reads or writes, | |
1200 | * and it's beneficial to allow the first worker to bring the | |
1201 | * page in and the piggy backed work can then work on the | |
1202 | * cached page. | |
1203 | */ | |
1204 | start = al->io_start & PAGE_MASK; | |
1205 | end = (al->io_start + al->io_len + PAGE_SIZE - 1) & PAGE_MASK; | |
1206 | if (kiocb->ki_pos >= start && kiocb->ki_pos <= end) | |
1207 | return true; | |
1208 | } | |
1209 | ||
1210 | al->file = NULL; | |
1211 | return false; | |
1212 | } | |
1213 | ||
31b51510 JA |
1214 | /* |
1215 | * Make a note of the last file/offset/direction we punted to async | |
1216 | * context. We'll use this information to see if we can piggy back a | |
1217 | * sequential request onto the previous one, if it's still hasn't been | |
1218 | * completed by the async worker. | |
1219 | */ | |
1220 | static void io_async_list_note(int rw, struct io_kiocb *req, size_t len) | |
1221 | { | |
1222 | struct async_list *async_list = &req->ctx->pending_async[rw]; | |
1223 | struct kiocb *kiocb = &req->rw; | |
1224 | struct file *filp = kiocb->ki_filp; | |
31b51510 | 1225 | |
6d5d5ac5 | 1226 | if (io_should_merge(async_list, kiocb)) { |
9310a7ba | 1227 | unsigned long max_bytes; |
31b51510 JA |
1228 | |
1229 | /* Use 8x RA size as a decent limiter for both reads/writes */ | |
9310a7ba ZL |
1230 | max_bytes = filp->f_ra.ra_pages << (PAGE_SHIFT + 3); |
1231 | if (!max_bytes) | |
1232 | max_bytes = VM_READAHEAD_PAGES << (PAGE_SHIFT + 3); | |
1233 | ||
1234 | /* If max len are exceeded, reset the state */ | |
1235 | if (async_list->io_len + len <= max_bytes) { | |
31b51510 | 1236 | req->flags |= REQ_F_SEQ_PREV; |
9310a7ba | 1237 | async_list->io_len += len; |
31b51510 | 1238 | } else { |
6d5d5ac5 | 1239 | async_list->file = NULL; |
31b51510 JA |
1240 | } |
1241 | } | |
1242 | ||
1243 | /* New file? Reset state. */ | |
1244 | if (async_list->file != filp) { | |
6d5d5ac5 JA |
1245 | async_list->io_start = kiocb->ki_pos; |
1246 | async_list->io_len = len; | |
31b51510 JA |
1247 | async_list->file = filp; |
1248 | } | |
31b51510 JA |
1249 | } |
1250 | ||
e0c5c576 | 1251 | static int io_read(struct io_kiocb *req, const struct sqe_submit *s, |
8358e3a8 | 1252 | bool force_nonblock) |
2b188cc1 JA |
1253 | { |
1254 | struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; | |
1255 | struct kiocb *kiocb = &req->rw; | |
1256 | struct iov_iter iter; | |
1257 | struct file *file; | |
31b51510 | 1258 | size_t iov_count; |
9d93a3f5 | 1259 | ssize_t read_size, ret; |
2b188cc1 | 1260 | |
8358e3a8 | 1261 | ret = io_prep_rw(req, s, force_nonblock); |
2b188cc1 JA |
1262 | if (ret) |
1263 | return ret; | |
1264 | file = kiocb->ki_filp; | |
1265 | ||
2b188cc1 | 1266 | if (unlikely(!(file->f_mode & FMODE_READ))) |
09bb8394 | 1267 | return -EBADF; |
2b188cc1 | 1268 | if (unlikely(!file->f_op->read_iter)) |
09bb8394 | 1269 | return -EINVAL; |
2b188cc1 JA |
1270 | |
1271 | ret = io_import_iovec(req->ctx, READ, s, &iovec, &iter); | |
87e5e6da | 1272 | if (ret < 0) |
09bb8394 | 1273 | return ret; |
2b188cc1 | 1274 | |
9d93a3f5 | 1275 | read_size = ret; |
9e645e11 JA |
1276 | if (req->flags & REQ_F_LINK) |
1277 | req->result = read_size; | |
1278 | ||
31b51510 JA |
1279 | iov_count = iov_iter_count(&iter); |
1280 | ret = rw_verify_area(READ, file, &kiocb->ki_pos, iov_count); | |
2b188cc1 JA |
1281 | if (!ret) { |
1282 | ssize_t ret2; | |
1283 | ||
2b188cc1 | 1284 | ret2 = call_read_iter(file, kiocb, &iter); |
9d93a3f5 JA |
1285 | /* |
1286 | * In case of a short read, punt to async. This can happen | |
1287 | * if we have data partially cached. Alternatively we can | |
1288 | * return the short read, in which case the application will | |
1289 | * need to issue another SQE and wait for it. That SQE will | |
1290 | * need async punt anyway, so it's more efficient to do it | |
1291 | * here. | |
1292 | */ | |
1293 | if (force_nonblock && ret2 > 0 && ret2 < read_size) | |
1294 | ret2 = -EAGAIN; | |
1295 | /* Catch -EAGAIN return for forced non-blocking submission */ | |
31b51510 | 1296 | if (!force_nonblock || ret2 != -EAGAIN) { |
2b188cc1 | 1297 | io_rw_done(kiocb, ret2); |
31b51510 JA |
1298 | } else { |
1299 | /* | |
1300 | * If ->needs_lock is true, we're already in async | |
1301 | * context. | |
1302 | */ | |
1303 | if (!s->needs_lock) | |
1304 | io_async_list_note(READ, req, iov_count); | |
2b188cc1 | 1305 | ret = -EAGAIN; |
31b51510 | 1306 | } |
2b188cc1 JA |
1307 | } |
1308 | kfree(iovec); | |
2b188cc1 JA |
1309 | return ret; |
1310 | } | |
1311 | ||
e0c5c576 | 1312 | static int io_write(struct io_kiocb *req, const struct sqe_submit *s, |
8358e3a8 | 1313 | bool force_nonblock) |
2b188cc1 JA |
1314 | { |
1315 | struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; | |
1316 | struct kiocb *kiocb = &req->rw; | |
1317 | struct iov_iter iter; | |
1318 | struct file *file; | |
31b51510 | 1319 | size_t iov_count; |
87e5e6da | 1320 | ssize_t ret; |
2b188cc1 | 1321 | |
8358e3a8 | 1322 | ret = io_prep_rw(req, s, force_nonblock); |
2b188cc1 JA |
1323 | if (ret) |
1324 | return ret; | |
2b188cc1 | 1325 | |
2b188cc1 JA |
1326 | file = kiocb->ki_filp; |
1327 | if (unlikely(!(file->f_mode & FMODE_WRITE))) | |
09bb8394 | 1328 | return -EBADF; |
2b188cc1 | 1329 | if (unlikely(!file->f_op->write_iter)) |
09bb8394 | 1330 | return -EINVAL; |
2b188cc1 JA |
1331 | |
1332 | ret = io_import_iovec(req->ctx, WRITE, s, &iovec, &iter); | |
87e5e6da | 1333 | if (ret < 0) |
09bb8394 | 1334 | return ret; |
2b188cc1 | 1335 | |
9e645e11 JA |
1336 | if (req->flags & REQ_F_LINK) |
1337 | req->result = ret; | |
1338 | ||
31b51510 JA |
1339 | iov_count = iov_iter_count(&iter); |
1340 | ||
1341 | ret = -EAGAIN; | |
1342 | if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT)) { | |
1343 | /* If ->needs_lock is true, we're already in async context. */ | |
1344 | if (!s->needs_lock) | |
1345 | io_async_list_note(WRITE, req, iov_count); | |
1346 | goto out_free; | |
1347 | } | |
1348 | ||
1349 | ret = rw_verify_area(WRITE, file, &kiocb->ki_pos, iov_count); | |
2b188cc1 | 1350 | if (!ret) { |
9bf7933f RP |
1351 | ssize_t ret2; |
1352 | ||
2b188cc1 JA |
1353 | /* |
1354 | * Open-code file_start_write here to grab freeze protection, | |
1355 | * which will be released by another thread in | |
1356 | * io_complete_rw(). Fool lockdep by telling it the lock got | |
1357 | * released so that it doesn't complain about the held lock when | |
1358 | * we return to userspace. | |
1359 | */ | |
1360 | if (S_ISREG(file_inode(file)->i_mode)) { | |
1361 | __sb_start_write(file_inode(file)->i_sb, | |
1362 | SB_FREEZE_WRITE, true); | |
1363 | __sb_writers_release(file_inode(file)->i_sb, | |
1364 | SB_FREEZE_WRITE); | |
1365 | } | |
1366 | kiocb->ki_flags |= IOCB_WRITE; | |
9bf7933f RP |
1367 | |
1368 | ret2 = call_write_iter(file, kiocb, &iter); | |
1369 | if (!force_nonblock || ret2 != -EAGAIN) { | |
1370 | io_rw_done(kiocb, ret2); | |
1371 | } else { | |
1372 | /* | |
1373 | * If ->needs_lock is true, we're already in async | |
1374 | * context. | |
1375 | */ | |
1376 | if (!s->needs_lock) | |
1377 | io_async_list_note(WRITE, req, iov_count); | |
1378 | ret = -EAGAIN; | |
1379 | } | |
2b188cc1 | 1380 | } |
31b51510 | 1381 | out_free: |
2b188cc1 | 1382 | kfree(iovec); |
2b188cc1 JA |
1383 | return ret; |
1384 | } | |
1385 | ||
1386 | /* | |
1387 | * IORING_OP_NOP just posts a completion event, nothing else. | |
1388 | */ | |
1389 | static int io_nop(struct io_kiocb *req, u64 user_data) | |
1390 | { | |
1391 | struct io_ring_ctx *ctx = req->ctx; | |
1392 | long err = 0; | |
1393 | ||
def596e9 JA |
1394 | if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
1395 | return -EINVAL; | |
1396 | ||
c71ffb67 | 1397 | io_cqring_add_event(ctx, user_data, err); |
e65ef56d | 1398 | io_put_req(req); |
2b188cc1 JA |
1399 | return 0; |
1400 | } | |
1401 | ||
c992fe29 CH |
1402 | static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
1403 | { | |
6b06314c | 1404 | struct io_ring_ctx *ctx = req->ctx; |
c992fe29 | 1405 | |
09bb8394 JA |
1406 | if (!req->file) |
1407 | return -EBADF; | |
c992fe29 | 1408 | |
6b06314c | 1409 | if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) |
def596e9 | 1410 | return -EINVAL; |
edafccee | 1411 | if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) |
c992fe29 CH |
1412 | return -EINVAL; |
1413 | ||
c992fe29 CH |
1414 | return 0; |
1415 | } | |
1416 | ||
1417 | static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, | |
1418 | bool force_nonblock) | |
1419 | { | |
1420 | loff_t sqe_off = READ_ONCE(sqe->off); | |
1421 | loff_t sqe_len = READ_ONCE(sqe->len); | |
1422 | loff_t end = sqe_off + sqe_len; | |
1423 | unsigned fsync_flags; | |
1424 | int ret; | |
1425 | ||
1426 | fsync_flags = READ_ONCE(sqe->fsync_flags); | |
1427 | if (unlikely(fsync_flags & ~IORING_FSYNC_DATASYNC)) | |
1428 | return -EINVAL; | |
1429 | ||
1430 | ret = io_prep_fsync(req, sqe); | |
1431 | if (ret) | |
1432 | return ret; | |
1433 | ||
1434 | /* fsync always requires a blocking context */ | |
1435 | if (force_nonblock) | |
1436 | return -EAGAIN; | |
1437 | ||
1438 | ret = vfs_fsync_range(req->rw.ki_filp, sqe_off, | |
1439 | end > 0 ? end : LLONG_MAX, | |
1440 | fsync_flags & IORING_FSYNC_DATASYNC); | |
1441 | ||
9e645e11 JA |
1442 | if (ret < 0 && (req->flags & REQ_F_LINK)) |
1443 | req->flags |= REQ_F_FAIL_LINK; | |
c71ffb67 | 1444 | io_cqring_add_event(req->ctx, sqe->user_data, ret); |
e65ef56d | 1445 | io_put_req(req); |
c992fe29 CH |
1446 | return 0; |
1447 | } | |
1448 | ||
5d17b4a4 JA |
1449 | static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
1450 | { | |
1451 | struct io_ring_ctx *ctx = req->ctx; | |
1452 | int ret = 0; | |
1453 | ||
1454 | if (!req->file) | |
1455 | return -EBADF; | |
5d17b4a4 JA |
1456 | |
1457 | if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) | |
1458 | return -EINVAL; | |
1459 | if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index)) | |
1460 | return -EINVAL; | |
1461 | ||
5d17b4a4 JA |
1462 | return ret; |
1463 | } | |
1464 | ||
1465 | static int io_sync_file_range(struct io_kiocb *req, | |
1466 | const struct io_uring_sqe *sqe, | |
1467 | bool force_nonblock) | |
1468 | { | |
1469 | loff_t sqe_off; | |
1470 | loff_t sqe_len; | |
1471 | unsigned flags; | |
1472 | int ret; | |
1473 | ||
1474 | ret = io_prep_sfr(req, sqe); | |
1475 | if (ret) | |
1476 | return ret; | |
1477 | ||
1478 | /* sync_file_range always requires a blocking context */ | |
1479 | if (force_nonblock) | |
1480 | return -EAGAIN; | |
1481 | ||
1482 | sqe_off = READ_ONCE(sqe->off); | |
1483 | sqe_len = READ_ONCE(sqe->len); | |
1484 | flags = READ_ONCE(sqe->sync_range_flags); | |
1485 | ||
1486 | ret = sync_file_range(req->rw.ki_filp, sqe_off, sqe_len, flags); | |
1487 | ||
9e645e11 JA |
1488 | if (ret < 0 && (req->flags & REQ_F_LINK)) |
1489 | req->flags |= REQ_F_FAIL_LINK; | |
c71ffb67 | 1490 | io_cqring_add_event(req->ctx, sqe->user_data, ret); |
5d17b4a4 JA |
1491 | io_put_req(req); |
1492 | return 0; | |
1493 | } | |
1494 | ||
0fa03c62 | 1495 | #if defined(CONFIG_NET) |
aa1fa28f JA |
1496 | static int io_send_recvmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, |
1497 | bool force_nonblock, | |
1498 | long (*fn)(struct socket *, struct user_msghdr __user *, | |
1499 | unsigned int)) | |
1500 | { | |
0fa03c62 JA |
1501 | struct socket *sock; |
1502 | int ret; | |
1503 | ||
1504 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
1505 | return -EINVAL; | |
1506 | ||
1507 | sock = sock_from_file(req->file, &ret); | |
1508 | if (sock) { | |
1509 | struct user_msghdr __user *msg; | |
1510 | unsigned flags; | |
1511 | ||
1512 | flags = READ_ONCE(sqe->msg_flags); | |
1513 | if (flags & MSG_DONTWAIT) | |
1514 | req->flags |= REQ_F_NOWAIT; | |
1515 | else if (force_nonblock) | |
1516 | flags |= MSG_DONTWAIT; | |
1517 | ||
1518 | msg = (struct user_msghdr __user *) (unsigned long) | |
1519 | READ_ONCE(sqe->addr); | |
1520 | ||
aa1fa28f | 1521 | ret = fn(sock, msg, flags); |
0fa03c62 JA |
1522 | if (force_nonblock && ret == -EAGAIN) |
1523 | return ret; | |
1524 | } | |
1525 | ||
c71ffb67 | 1526 | io_cqring_add_event(req->ctx, sqe->user_data, ret); |
5d17b4a4 JA |
1527 | io_put_req(req); |
1528 | return 0; | |
1529 | } | |
aa1fa28f JA |
1530 | #endif |
1531 | ||
1532 | static int io_sendmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, | |
1533 | bool force_nonblock) | |
1534 | { | |
1535 | #if defined(CONFIG_NET) | |
1536 | return io_send_recvmsg(req, sqe, force_nonblock, __sys_sendmsg_sock); | |
1537 | #else | |
1538 | return -EOPNOTSUPP; | |
1539 | #endif | |
1540 | } | |
1541 | ||
1542 | static int io_recvmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, | |
1543 | bool force_nonblock) | |
1544 | { | |
1545 | #if defined(CONFIG_NET) | |
1546 | return io_send_recvmsg(req, sqe, force_nonblock, __sys_recvmsg_sock); | |
0fa03c62 JA |
1547 | #else |
1548 | return -EOPNOTSUPP; | |
1549 | #endif | |
1550 | } | |
5d17b4a4 | 1551 | |
221c5eb2 JA |
1552 | static void io_poll_remove_one(struct io_kiocb *req) |
1553 | { | |
1554 | struct io_poll_iocb *poll = &req->poll; | |
1555 | ||
1556 | spin_lock(&poll->head->lock); | |
1557 | WRITE_ONCE(poll->canceled, true); | |
1558 | if (!list_empty(&poll->wait.entry)) { | |
1559 | list_del_init(&poll->wait.entry); | |
18d9be1a | 1560 | io_queue_async_work(req->ctx, req); |
221c5eb2 JA |
1561 | } |
1562 | spin_unlock(&poll->head->lock); | |
1563 | ||
1564 | list_del_init(&req->list); | |
1565 | } | |
1566 | ||
1567 | static void io_poll_remove_all(struct io_ring_ctx *ctx) | |
1568 | { | |
1569 | struct io_kiocb *req; | |
1570 | ||
1571 | spin_lock_irq(&ctx->completion_lock); | |
1572 | while (!list_empty(&ctx->cancel_list)) { | |
1573 | req = list_first_entry(&ctx->cancel_list, struct io_kiocb,list); | |
1574 | io_poll_remove_one(req); | |
1575 | } | |
1576 | spin_unlock_irq(&ctx->completion_lock); | |
1577 | } | |
1578 | ||
1579 | /* | |
1580 | * Find a running poll command that matches one specified in sqe->addr, | |
1581 | * and remove it if found. | |
1582 | */ | |
1583 | static int io_poll_remove(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
1584 | { | |
1585 | struct io_ring_ctx *ctx = req->ctx; | |
1586 | struct io_kiocb *poll_req, *next; | |
1587 | int ret = -ENOENT; | |
1588 | ||
1589 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
1590 | return -EINVAL; | |
1591 | if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index || | |
1592 | sqe->poll_events) | |
1593 | return -EINVAL; | |
1594 | ||
1595 | spin_lock_irq(&ctx->completion_lock); | |
1596 | list_for_each_entry_safe(poll_req, next, &ctx->cancel_list, list) { | |
1597 | if (READ_ONCE(sqe->addr) == poll_req->user_data) { | |
1598 | io_poll_remove_one(poll_req); | |
1599 | ret = 0; | |
1600 | break; | |
1601 | } | |
1602 | } | |
1603 | spin_unlock_irq(&ctx->completion_lock); | |
1604 | ||
c71ffb67 | 1605 | io_cqring_add_event(req->ctx, sqe->user_data, ret); |
e65ef56d | 1606 | io_put_req(req); |
221c5eb2 JA |
1607 | return 0; |
1608 | } | |
1609 | ||
8c838788 JA |
1610 | static void io_poll_complete(struct io_ring_ctx *ctx, struct io_kiocb *req, |
1611 | __poll_t mask) | |
221c5eb2 | 1612 | { |
8c838788 | 1613 | req->poll.done = true; |
c71ffb67 | 1614 | io_cqring_fill_event(ctx, req->user_data, mangle_poll(mask)); |
8c838788 | 1615 | io_commit_cqring(ctx); |
221c5eb2 JA |
1616 | } |
1617 | ||
1618 | static void io_poll_complete_work(struct work_struct *work) | |
1619 | { | |
1620 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
1621 | struct io_poll_iocb *poll = &req->poll; | |
1622 | struct poll_table_struct pt = { ._key = poll->events }; | |
1623 | struct io_ring_ctx *ctx = req->ctx; | |
1624 | __poll_t mask = 0; | |
1625 | ||
1626 | if (!READ_ONCE(poll->canceled)) | |
1627 | mask = vfs_poll(poll->file, &pt) & poll->events; | |
1628 | ||
1629 | /* | |
1630 | * Note that ->ki_cancel callers also delete iocb from active_reqs after | |
1631 | * calling ->ki_cancel. We need the ctx_lock roundtrip here to | |
1632 | * synchronize with them. In the cancellation case the list_del_init | |
1633 | * itself is not actually needed, but harmless so we keep it in to | |
1634 | * avoid further branches in the fast path. | |
1635 | */ | |
1636 | spin_lock_irq(&ctx->completion_lock); | |
1637 | if (!mask && !READ_ONCE(poll->canceled)) { | |
1638 | add_wait_queue(poll->head, &poll->wait); | |
1639 | spin_unlock_irq(&ctx->completion_lock); | |
1640 | return; | |
1641 | } | |
1642 | list_del_init(&req->list); | |
8c838788 | 1643 | io_poll_complete(ctx, req, mask); |
221c5eb2 JA |
1644 | spin_unlock_irq(&ctx->completion_lock); |
1645 | ||
8c838788 JA |
1646 | io_cqring_ev_posted(ctx); |
1647 | io_put_req(req); | |
221c5eb2 JA |
1648 | } |
1649 | ||
1650 | static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, | |
1651 | void *key) | |
1652 | { | |
1653 | struct io_poll_iocb *poll = container_of(wait, struct io_poll_iocb, | |
1654 | wait); | |
1655 | struct io_kiocb *req = container_of(poll, struct io_kiocb, poll); | |
1656 | struct io_ring_ctx *ctx = req->ctx; | |
1657 | __poll_t mask = key_to_poll(key); | |
8c838788 | 1658 | unsigned long flags; |
221c5eb2 JA |
1659 | |
1660 | /* for instances that support it check for an event match first: */ | |
8c838788 JA |
1661 | if (mask && !(mask & poll->events)) |
1662 | return 0; | |
221c5eb2 | 1663 | |
8c838788 | 1664 | list_del_init(&poll->wait.entry); |
221c5eb2 | 1665 | |
8c838788 JA |
1666 | if (mask && spin_trylock_irqsave(&ctx->completion_lock, flags)) { |
1667 | list_del(&req->list); | |
1668 | io_poll_complete(ctx, req, mask); | |
1669 | spin_unlock_irqrestore(&ctx->completion_lock, flags); | |
221c5eb2 | 1670 | |
8c838788 JA |
1671 | io_cqring_ev_posted(ctx); |
1672 | io_put_req(req); | |
1673 | } else { | |
18d9be1a | 1674 | io_queue_async_work(ctx, req); |
221c5eb2 JA |
1675 | } |
1676 | ||
221c5eb2 JA |
1677 | return 1; |
1678 | } | |
1679 | ||
1680 | struct io_poll_table { | |
1681 | struct poll_table_struct pt; | |
1682 | struct io_kiocb *req; | |
1683 | int error; | |
1684 | }; | |
1685 | ||
1686 | static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head, | |
1687 | struct poll_table_struct *p) | |
1688 | { | |
1689 | struct io_poll_table *pt = container_of(p, struct io_poll_table, pt); | |
1690 | ||
1691 | if (unlikely(pt->req->poll.head)) { | |
1692 | pt->error = -EINVAL; | |
1693 | return; | |
1694 | } | |
1695 | ||
1696 | pt->error = 0; | |
1697 | pt->req->poll.head = head; | |
1698 | add_wait_queue(head, &pt->req->poll.wait); | |
1699 | } | |
1700 | ||
1701 | static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe) | |
1702 | { | |
1703 | struct io_poll_iocb *poll = &req->poll; | |
1704 | struct io_ring_ctx *ctx = req->ctx; | |
1705 | struct io_poll_table ipt; | |
8c838788 | 1706 | bool cancel = false; |
221c5eb2 JA |
1707 | __poll_t mask; |
1708 | u16 events; | |
221c5eb2 JA |
1709 | |
1710 | if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) | |
1711 | return -EINVAL; | |
1712 | if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index) | |
1713 | return -EINVAL; | |
09bb8394 JA |
1714 | if (!poll->file) |
1715 | return -EBADF; | |
221c5eb2 JA |
1716 | |
1717 | INIT_WORK(&req->work, io_poll_complete_work); | |
1718 | events = READ_ONCE(sqe->poll_events); | |
1719 | poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP; | |
1720 | ||
221c5eb2 | 1721 | poll->head = NULL; |
8c838788 | 1722 | poll->done = false; |
221c5eb2 JA |
1723 | poll->canceled = false; |
1724 | ||
1725 | ipt.pt._qproc = io_poll_queue_proc; | |
1726 | ipt.pt._key = poll->events; | |
1727 | ipt.req = req; | |
1728 | ipt.error = -EINVAL; /* same as no support for IOCB_CMD_POLL */ | |
1729 | ||
1730 | /* initialized the list so that we can do list_empty checks */ | |
1731 | INIT_LIST_HEAD(&poll->wait.entry); | |
1732 | init_waitqueue_func_entry(&poll->wait, io_poll_wake); | |
1733 | ||
36703247 JA |
1734 | INIT_LIST_HEAD(&req->list); |
1735 | ||
221c5eb2 | 1736 | mask = vfs_poll(poll->file, &ipt.pt) & poll->events; |
221c5eb2 JA |
1737 | |
1738 | spin_lock_irq(&ctx->completion_lock); | |
8c838788 JA |
1739 | if (likely(poll->head)) { |
1740 | spin_lock(&poll->head->lock); | |
1741 | if (unlikely(list_empty(&poll->wait.entry))) { | |
1742 | if (ipt.error) | |
1743 | cancel = true; | |
1744 | ipt.error = 0; | |
1745 | mask = 0; | |
1746 | } | |
1747 | if (mask || ipt.error) | |
1748 | list_del_init(&poll->wait.entry); | |
1749 | else if (cancel) | |
1750 | WRITE_ONCE(poll->canceled, true); | |
1751 | else if (!poll->done) /* actually waiting for an event */ | |
1752 | list_add_tail(&req->list, &ctx->cancel_list); | |
1753 | spin_unlock(&poll->head->lock); | |
1754 | } | |
1755 | if (mask) { /* no async, we'd stolen it */ | |
221c5eb2 | 1756 | ipt.error = 0; |
8c838788 | 1757 | io_poll_complete(ctx, req, mask); |
221c5eb2 | 1758 | } |
221c5eb2 JA |
1759 | spin_unlock_irq(&ctx->completion_lock); |
1760 | ||
8c838788 JA |
1761 | if (mask) { |
1762 | io_cqring_ev_posted(ctx); | |
e65ef56d | 1763 | io_put_req(req); |
221c5eb2 | 1764 | } |
8c838788 | 1765 | return ipt.error; |
221c5eb2 JA |
1766 | } |
1767 | ||
de0617e4 JA |
1768 | static int io_req_defer(struct io_ring_ctx *ctx, struct io_kiocb *req, |
1769 | const struct io_uring_sqe *sqe) | |
1770 | { | |
1771 | struct io_uring_sqe *sqe_copy; | |
1772 | ||
1773 | if (!io_sequence_defer(ctx, req) && list_empty(&ctx->defer_list)) | |
1774 | return 0; | |
1775 | ||
1776 | sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL); | |
1777 | if (!sqe_copy) | |
1778 | return -EAGAIN; | |
1779 | ||
1780 | spin_lock_irq(&ctx->completion_lock); | |
1781 | if (!io_sequence_defer(ctx, req) && list_empty(&ctx->defer_list)) { | |
1782 | spin_unlock_irq(&ctx->completion_lock); | |
1783 | kfree(sqe_copy); | |
1784 | return 0; | |
1785 | } | |
1786 | ||
1787 | memcpy(sqe_copy, sqe, sizeof(*sqe_copy)); | |
1788 | req->submit.sqe = sqe_copy; | |
1789 | ||
1790 | INIT_WORK(&req->work, io_sq_wq_submit_work); | |
1791 | list_add_tail(&req->list, &ctx->defer_list); | |
1792 | spin_unlock_irq(&ctx->completion_lock); | |
1793 | return -EIOCBQUEUED; | |
1794 | } | |
1795 | ||
2b188cc1 | 1796 | static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, |
8358e3a8 | 1797 | const struct sqe_submit *s, bool force_nonblock) |
2b188cc1 | 1798 | { |
e0c5c576 | 1799 | int ret, opcode; |
2b188cc1 | 1800 | |
9e645e11 JA |
1801 | req->user_data = READ_ONCE(s->sqe->user_data); |
1802 | ||
2b188cc1 JA |
1803 | if (unlikely(s->index >= ctx->sq_entries)) |
1804 | return -EINVAL; | |
2b188cc1 JA |
1805 | |
1806 | opcode = READ_ONCE(s->sqe->opcode); | |
1807 | switch (opcode) { | |
1808 | case IORING_OP_NOP: | |
1809 | ret = io_nop(req, req->user_data); | |
1810 | break; | |
1811 | case IORING_OP_READV: | |
edafccee JA |
1812 | if (unlikely(s->sqe->buf_index)) |
1813 | return -EINVAL; | |
8358e3a8 | 1814 | ret = io_read(req, s, force_nonblock); |
2b188cc1 JA |
1815 | break; |
1816 | case IORING_OP_WRITEV: | |
edafccee JA |
1817 | if (unlikely(s->sqe->buf_index)) |
1818 | return -EINVAL; | |
8358e3a8 | 1819 | ret = io_write(req, s, force_nonblock); |
edafccee JA |
1820 | break; |
1821 | case IORING_OP_READ_FIXED: | |
8358e3a8 | 1822 | ret = io_read(req, s, force_nonblock); |
edafccee JA |
1823 | break; |
1824 | case IORING_OP_WRITE_FIXED: | |
8358e3a8 | 1825 | ret = io_write(req, s, force_nonblock); |
2b188cc1 | 1826 | break; |
c992fe29 CH |
1827 | case IORING_OP_FSYNC: |
1828 | ret = io_fsync(req, s->sqe, force_nonblock); | |
1829 | break; | |
221c5eb2 JA |
1830 | case IORING_OP_POLL_ADD: |
1831 | ret = io_poll_add(req, s->sqe); | |
1832 | break; | |
1833 | case IORING_OP_POLL_REMOVE: | |
1834 | ret = io_poll_remove(req, s->sqe); | |
1835 | break; | |
5d17b4a4 JA |
1836 | case IORING_OP_SYNC_FILE_RANGE: |
1837 | ret = io_sync_file_range(req, s->sqe, force_nonblock); | |
1838 | break; | |
0fa03c62 JA |
1839 | case IORING_OP_SENDMSG: |
1840 | ret = io_sendmsg(req, s->sqe, force_nonblock); | |
1841 | break; | |
aa1fa28f JA |
1842 | case IORING_OP_RECVMSG: |
1843 | ret = io_recvmsg(req, s->sqe, force_nonblock); | |
1844 | break; | |
2b188cc1 JA |
1845 | default: |
1846 | ret = -EINVAL; | |
1847 | break; | |
1848 | } | |
1849 | ||
def596e9 JA |
1850 | if (ret) |
1851 | return ret; | |
1852 | ||
1853 | if (ctx->flags & IORING_SETUP_IOPOLL) { | |
9e645e11 | 1854 | if (req->result == -EAGAIN) |
def596e9 JA |
1855 | return -EAGAIN; |
1856 | ||
1857 | /* workqueue context doesn't hold uring_lock, grab it now */ | |
1858 | if (s->needs_lock) | |
1859 | mutex_lock(&ctx->uring_lock); | |
1860 | io_iopoll_req_issued(req); | |
1861 | if (s->needs_lock) | |
1862 | mutex_unlock(&ctx->uring_lock); | |
1863 | } | |
1864 | ||
1865 | return 0; | |
2b188cc1 JA |
1866 | } |
1867 | ||
31b51510 JA |
1868 | static struct async_list *io_async_list_from_sqe(struct io_ring_ctx *ctx, |
1869 | const struct io_uring_sqe *sqe) | |
1870 | { | |
1871 | switch (sqe->opcode) { | |
1872 | case IORING_OP_READV: | |
1873 | case IORING_OP_READ_FIXED: | |
1874 | return &ctx->pending_async[READ]; | |
1875 | case IORING_OP_WRITEV: | |
1876 | case IORING_OP_WRITE_FIXED: | |
1877 | return &ctx->pending_async[WRITE]; | |
1878 | default: | |
1879 | return NULL; | |
1880 | } | |
1881 | } | |
1882 | ||
edafccee JA |
1883 | static inline bool io_sqe_needs_user(const struct io_uring_sqe *sqe) |
1884 | { | |
1885 | u8 opcode = READ_ONCE(sqe->opcode); | |
1886 | ||
1887 | return !(opcode == IORING_OP_READ_FIXED || | |
1888 | opcode == IORING_OP_WRITE_FIXED); | |
1889 | } | |
1890 | ||
2b188cc1 JA |
1891 | static void io_sq_wq_submit_work(struct work_struct *work) |
1892 | { | |
1893 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
2b188cc1 | 1894 | struct io_ring_ctx *ctx = req->ctx; |
31b51510 JA |
1895 | struct mm_struct *cur_mm = NULL; |
1896 | struct async_list *async_list; | |
1897 | LIST_HEAD(req_list); | |
edafccee | 1898 | mm_segment_t old_fs; |
2b188cc1 JA |
1899 | int ret; |
1900 | ||
31b51510 JA |
1901 | async_list = io_async_list_from_sqe(ctx, req->submit.sqe); |
1902 | restart: | |
1903 | do { | |
1904 | struct sqe_submit *s = &req->submit; | |
1905 | const struct io_uring_sqe *sqe = s->sqe; | |
d0ee8791 | 1906 | unsigned int flags = req->flags; |
2b188cc1 | 1907 | |
8449eeda | 1908 | /* Ensure we clear previously set non-block flag */ |
31b51510 JA |
1909 | req->rw.ki_flags &= ~IOCB_NOWAIT; |
1910 | ||
1911 | ret = 0; | |
1912 | if (io_sqe_needs_user(sqe) && !cur_mm) { | |
1913 | if (!mmget_not_zero(ctx->sqo_mm)) { | |
1914 | ret = -EFAULT; | |
1915 | } else { | |
1916 | cur_mm = ctx->sqo_mm; | |
1917 | use_mm(cur_mm); | |
1918 | old_fs = get_fs(); | |
1919 | set_fs(USER_DS); | |
1920 | } | |
1921 | } | |
1922 | ||
1923 | if (!ret) { | |
1924 | s->has_user = cur_mm != NULL; | |
1925 | s->needs_lock = true; | |
1926 | do { | |
8358e3a8 | 1927 | ret = __io_submit_sqe(ctx, req, s, false); |
31b51510 JA |
1928 | /* |
1929 | * We can get EAGAIN for polled IO even though | |
1930 | * we're forcing a sync submission from here, | |
1931 | * since we can't wait for request slots on the | |
1932 | * block side. | |
1933 | */ | |
1934 | if (ret != -EAGAIN) | |
1935 | break; | |
1936 | cond_resched(); | |
1937 | } while (1); | |
1938 | } | |
817869d2 JA |
1939 | |
1940 | /* drop submission reference */ | |
1941 | io_put_req(req); | |
1942 | ||
31b51510 | 1943 | if (ret) { |
c71ffb67 | 1944 | io_cqring_add_event(ctx, sqe->user_data, ret); |
e65ef56d | 1945 | io_put_req(req); |
31b51510 JA |
1946 | } |
1947 | ||
1948 | /* async context always use a copy of the sqe */ | |
1949 | kfree(sqe); | |
1950 | ||
f7b76ac9 | 1951 | /* req from defer and link list needn't decrease async cnt */ |
d0ee8791 | 1952 | if (flags & (REQ_F_IO_DRAINED | REQ_F_LINK_DONE)) |
f7b76ac9 ZL |
1953 | goto out; |
1954 | ||
31b51510 JA |
1955 | if (!async_list) |
1956 | break; | |
1957 | if (!list_empty(&req_list)) { | |
1958 | req = list_first_entry(&req_list, struct io_kiocb, | |
1959 | list); | |
1960 | list_del(&req->list); | |
1961 | continue; | |
1962 | } | |
1963 | if (list_empty(&async_list->list)) | |
1964 | break; | |
1965 | ||
1966 | req = NULL; | |
1967 | spin_lock(&async_list->lock); | |
1968 | if (list_empty(&async_list->list)) { | |
1969 | spin_unlock(&async_list->lock); | |
1970 | break; | |
1971 | } | |
1972 | list_splice_init(&async_list->list, &req_list); | |
1973 | spin_unlock(&async_list->lock); | |
1974 | ||
1975 | req = list_first_entry(&req_list, struct io_kiocb, list); | |
1976 | list_del(&req->list); | |
1977 | } while (req); | |
edafccee JA |
1978 | |
1979 | /* | |
31b51510 JA |
1980 | * Rare case of racing with a submitter. If we find the count has |
1981 | * dropped to zero AND we have pending work items, then restart | |
1982 | * the processing. This is a tiny race window. | |
edafccee | 1983 | */ |
31b51510 JA |
1984 | if (async_list) { |
1985 | ret = atomic_dec_return(&async_list->cnt); | |
1986 | while (!ret && !list_empty(&async_list->list)) { | |
1987 | spin_lock(&async_list->lock); | |
1988 | atomic_inc(&async_list->cnt); | |
1989 | list_splice_init(&async_list->list, &req_list); | |
1990 | spin_unlock(&async_list->lock); | |
1991 | ||
1992 | if (!list_empty(&req_list)) { | |
1993 | req = list_first_entry(&req_list, | |
1994 | struct io_kiocb, list); | |
1995 | list_del(&req->list); | |
1996 | goto restart; | |
1997 | } | |
1998 | ret = atomic_dec_return(&async_list->cnt); | |
edafccee | 1999 | } |
edafccee | 2000 | } |
2b188cc1 | 2001 | |
f7b76ac9 | 2002 | out: |
31b51510 | 2003 | if (cur_mm) { |
edafccee | 2004 | set_fs(old_fs); |
31b51510 JA |
2005 | unuse_mm(cur_mm); |
2006 | mmput(cur_mm); | |
2b188cc1 | 2007 | } |
31b51510 | 2008 | } |
2b188cc1 | 2009 | |
31b51510 JA |
2010 | /* |
2011 | * See if we can piggy back onto previously submitted work, that is still | |
2012 | * running. We currently only allow this if the new request is sequential | |
2013 | * to the previous one we punted. | |
2014 | */ | |
2015 | static bool io_add_to_prev_work(struct async_list *list, struct io_kiocb *req) | |
2016 | { | |
6d5d5ac5 | 2017 | bool ret; |
31b51510 JA |
2018 | |
2019 | if (!list) | |
2020 | return false; | |
2021 | if (!(req->flags & REQ_F_SEQ_PREV)) | |
2022 | return false; | |
2023 | if (!atomic_read(&list->cnt)) | |
2024 | return false; | |
2025 | ||
2026 | ret = true; | |
2027 | spin_lock(&list->lock); | |
2028 | list_add_tail(&req->list, &list->list); | |
c0e48f9d ZL |
2029 | /* |
2030 | * Ensure we see a simultaneous modification from io_sq_wq_submit_work() | |
2031 | */ | |
2032 | smp_mb(); | |
31b51510 JA |
2033 | if (!atomic_read(&list->cnt)) { |
2034 | list_del_init(&req->list); | |
2035 | ret = false; | |
2036 | } | |
2037 | spin_unlock(&list->lock); | |
2038 | return ret; | |
2b188cc1 JA |
2039 | } |
2040 | ||
09bb8394 JA |
2041 | static bool io_op_needs_file(const struct io_uring_sqe *sqe) |
2042 | { | |
2043 | int op = READ_ONCE(sqe->opcode); | |
2044 | ||
2045 | switch (op) { | |
2046 | case IORING_OP_NOP: | |
2047 | case IORING_OP_POLL_REMOVE: | |
2048 | return false; | |
2049 | default: | |
2050 | return true; | |
2051 | } | |
2052 | } | |
2053 | ||
2054 | static int io_req_set_file(struct io_ring_ctx *ctx, const struct sqe_submit *s, | |
2055 | struct io_submit_state *state, struct io_kiocb *req) | |
2056 | { | |
2057 | unsigned flags; | |
2058 | int fd; | |
2059 | ||
2060 | flags = READ_ONCE(s->sqe->flags); | |
2061 | fd = READ_ONCE(s->sqe->fd); | |
2062 | ||
4fe2c963 | 2063 | if (flags & IOSQE_IO_DRAIN) |
de0617e4 | 2064 | req->flags |= REQ_F_IO_DRAIN; |
4fe2c963 JL |
2065 | /* |
2066 | * All io need record the previous position, if LINK vs DARIN, | |
2067 | * it can be used to mark the position of the first IO in the | |
2068 | * link list. | |
2069 | */ | |
2070 | req->sequence = s->sequence; | |
de0617e4 | 2071 | |
60c112b0 | 2072 | if (!io_op_needs_file(s->sqe)) |
09bb8394 | 2073 | return 0; |
09bb8394 JA |
2074 | |
2075 | if (flags & IOSQE_FIXED_FILE) { | |
2076 | if (unlikely(!ctx->user_files || | |
2077 | (unsigned) fd >= ctx->nr_user_files)) | |
2078 | return -EBADF; | |
2079 | req->file = ctx->user_files[fd]; | |
2080 | req->flags |= REQ_F_FIXED_FILE; | |
2081 | } else { | |
2082 | if (s->needs_fixed_file) | |
2083 | return -EBADF; | |
2084 | req->file = io_file_get(state, fd); | |
2085 | if (unlikely(!req->file)) | |
2086 | return -EBADF; | |
2087 | } | |
2088 | ||
2089 | return 0; | |
2090 | } | |
2091 | ||
4fe2c963 | 2092 | static int __io_queue_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, |
c5766668 | 2093 | struct sqe_submit *s, bool force_nonblock) |
2b188cc1 | 2094 | { |
e0c5c576 | 2095 | int ret; |
2b188cc1 | 2096 | |
c5766668 | 2097 | ret = __io_submit_sqe(ctx, req, s, force_nonblock); |
8449eeda | 2098 | if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) { |
2b188cc1 JA |
2099 | struct io_uring_sqe *sqe_copy; |
2100 | ||
2101 | sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL); | |
2102 | if (sqe_copy) { | |
31b51510 JA |
2103 | struct async_list *list; |
2104 | ||
2b188cc1 JA |
2105 | memcpy(sqe_copy, s->sqe, sizeof(*sqe_copy)); |
2106 | s->sqe = sqe_copy; | |
2107 | ||
2108 | memcpy(&req->submit, s, sizeof(*s)); | |
31b51510 JA |
2109 | list = io_async_list_from_sqe(ctx, s->sqe); |
2110 | if (!io_add_to_prev_work(list, req)) { | |
2111 | if (list) | |
2112 | atomic_inc(&list->cnt); | |
2113 | INIT_WORK(&req->work, io_sq_wq_submit_work); | |
18d9be1a | 2114 | io_queue_async_work(ctx, req); |
31b51510 | 2115 | } |
e65ef56d JA |
2116 | |
2117 | /* | |
2118 | * Queued up for async execution, worker will release | |
9e645e11 | 2119 | * submit reference when the iocb is actually submitted. |
e65ef56d JA |
2120 | */ |
2121 | return 0; | |
2b188cc1 JA |
2122 | } |
2123 | } | |
e65ef56d JA |
2124 | |
2125 | /* drop submission reference */ | |
2126 | io_put_req(req); | |
2127 | ||
2128 | /* and drop final reference, if we failed */ | |
9e645e11 JA |
2129 | if (ret) { |
2130 | io_cqring_add_event(ctx, req->user_data, ret); | |
2131 | if (req->flags & REQ_F_LINK) | |
2132 | req->flags |= REQ_F_FAIL_LINK; | |
e65ef56d | 2133 | io_put_req(req); |
9e645e11 | 2134 | } |
2b188cc1 JA |
2135 | |
2136 | return ret; | |
2137 | } | |
2138 | ||
4fe2c963 | 2139 | static int io_queue_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, |
c5766668 | 2140 | struct sqe_submit *s, bool force_nonblock) |
4fe2c963 JL |
2141 | { |
2142 | int ret; | |
2143 | ||
2144 | ret = io_req_defer(ctx, req, s->sqe); | |
2145 | if (ret) { | |
2146 | if (ret != -EIOCBQUEUED) { | |
2147 | io_free_req(req); | |
2148 | io_cqring_add_event(ctx, s->sqe->user_data, ret); | |
2149 | } | |
2150 | return 0; | |
2151 | } | |
2152 | ||
c5766668 | 2153 | return __io_queue_sqe(ctx, req, s, force_nonblock); |
4fe2c963 JL |
2154 | } |
2155 | ||
2156 | static int io_queue_link_head(struct io_ring_ctx *ctx, struct io_kiocb *req, | |
c5766668 JA |
2157 | struct sqe_submit *s, struct io_kiocb *shadow, |
2158 | bool force_nonblock) | |
4fe2c963 JL |
2159 | { |
2160 | int ret; | |
2161 | int need_submit = false; | |
2162 | ||
2163 | if (!shadow) | |
c5766668 | 2164 | return io_queue_sqe(ctx, req, s, force_nonblock); |
4fe2c963 JL |
2165 | |
2166 | /* | |
2167 | * Mark the first IO in link list as DRAIN, let all the following | |
2168 | * IOs enter the defer list. all IO needs to be completed before link | |
2169 | * list. | |
2170 | */ | |
2171 | req->flags |= REQ_F_IO_DRAIN; | |
2172 | ret = io_req_defer(ctx, req, s->sqe); | |
2173 | if (ret) { | |
2174 | if (ret != -EIOCBQUEUED) { | |
2175 | io_free_req(req); | |
2176 | io_cqring_add_event(ctx, s->sqe->user_data, ret); | |
2177 | return 0; | |
2178 | } | |
2179 | } else { | |
2180 | /* | |
2181 | * If ret == 0 means that all IOs in front of link io are | |
2182 | * running done. let's queue link head. | |
2183 | */ | |
2184 | need_submit = true; | |
2185 | } | |
2186 | ||
2187 | /* Insert shadow req to defer_list, blocking next IOs */ | |
2188 | spin_lock_irq(&ctx->completion_lock); | |
2189 | list_add_tail(&shadow->list, &ctx->defer_list); | |
2190 | spin_unlock_irq(&ctx->completion_lock); | |
2191 | ||
2192 | if (need_submit) | |
c5766668 | 2193 | return __io_queue_sqe(ctx, req, s, force_nonblock); |
4fe2c963 JL |
2194 | |
2195 | return 0; | |
2196 | } | |
2197 | ||
9e645e11 JA |
2198 | #define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK) |
2199 | ||
2200 | static void io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s, | |
c5766668 JA |
2201 | struct io_submit_state *state, struct io_kiocb **link, |
2202 | bool force_nonblock) | |
9e645e11 JA |
2203 | { |
2204 | struct io_uring_sqe *sqe_copy; | |
2205 | struct io_kiocb *req; | |
2206 | int ret; | |
2207 | ||
2208 | /* enforce forwards compatibility on users */ | |
2209 | if (unlikely(s->sqe->flags & ~SQE_VALID_FLAGS)) { | |
2210 | ret = -EINVAL; | |
2211 | goto err; | |
2212 | } | |
2213 | ||
2214 | req = io_get_req(ctx, state); | |
2215 | if (unlikely(!req)) { | |
2216 | ret = -EAGAIN; | |
2217 | goto err; | |
2218 | } | |
2219 | ||
2220 | ret = io_req_set_file(ctx, s, state, req); | |
2221 | if (unlikely(ret)) { | |
2222 | err_req: | |
2223 | io_free_req(req); | |
2224 | err: | |
2225 | io_cqring_add_event(ctx, s->sqe->user_data, ret); | |
2226 | return; | |
2227 | } | |
2228 | ||
9e645e11 JA |
2229 | /* |
2230 | * If we already have a head request, queue this one for async | |
2231 | * submittal once the head completes. If we don't have a head but | |
2232 | * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be | |
2233 | * submitted sync once the chain is complete. If none of those | |
2234 | * conditions are true (normal request), then just queue it. | |
2235 | */ | |
2236 | if (*link) { | |
2237 | struct io_kiocb *prev = *link; | |
2238 | ||
2239 | sqe_copy = kmemdup(s->sqe, sizeof(*sqe_copy), GFP_KERNEL); | |
2240 | if (!sqe_copy) { | |
2241 | ret = -EAGAIN; | |
2242 | goto err_req; | |
2243 | } | |
2244 | ||
2245 | s->sqe = sqe_copy; | |
2246 | memcpy(&req->submit, s, sizeof(*s)); | |
2247 | list_add_tail(&req->list, &prev->link_list); | |
2248 | } else if (s->sqe->flags & IOSQE_IO_LINK) { | |
2249 | req->flags |= REQ_F_LINK; | |
2250 | ||
2251 | memcpy(&req->submit, s, sizeof(*s)); | |
2252 | INIT_LIST_HEAD(&req->link_list); | |
2253 | *link = req; | |
2254 | } else { | |
c5766668 | 2255 | io_queue_sqe(ctx, req, s, force_nonblock); |
9e645e11 JA |
2256 | } |
2257 | } | |
2258 | ||
9a56a232 JA |
2259 | /* |
2260 | * Batched submission is done, ensure local IO is flushed out. | |
2261 | */ | |
2262 | static void io_submit_state_end(struct io_submit_state *state) | |
2263 | { | |
2264 | blk_finish_plug(&state->plug); | |
3d6770fb | 2265 | io_file_put(state); |
2579f913 JA |
2266 | if (state->free_reqs) |
2267 | kmem_cache_free_bulk(req_cachep, state->free_reqs, | |
2268 | &state->reqs[state->cur_req]); | |
9a56a232 JA |
2269 | } |
2270 | ||
2271 | /* | |
2272 | * Start submission side cache. | |
2273 | */ | |
2274 | static void io_submit_state_start(struct io_submit_state *state, | |
2275 | struct io_ring_ctx *ctx, unsigned max_ios) | |
2276 | { | |
2277 | blk_start_plug(&state->plug); | |
2579f913 | 2278 | state->free_reqs = 0; |
9a56a232 JA |
2279 | state->file = NULL; |
2280 | state->ios_left = max_ios; | |
2281 | } | |
2282 | ||
2b188cc1 JA |
2283 | static void io_commit_sqring(struct io_ring_ctx *ctx) |
2284 | { | |
75b28aff | 2285 | struct io_rings *rings = ctx->rings; |
2b188cc1 | 2286 | |
75b28aff | 2287 | if (ctx->cached_sq_head != READ_ONCE(rings->sq.head)) { |
2b188cc1 JA |
2288 | /* |
2289 | * Ensure any loads from the SQEs are done at this point, | |
2290 | * since once we write the new head, the application could | |
2291 | * write new data to them. | |
2292 | */ | |
75b28aff | 2293 | smp_store_release(&rings->sq.head, ctx->cached_sq_head); |
2b188cc1 JA |
2294 | } |
2295 | } | |
2296 | ||
2b188cc1 JA |
2297 | /* |
2298 | * Fetch an sqe, if one is available. Note that s->sqe will point to memory | |
2299 | * that is mapped by userspace. This means that care needs to be taken to | |
2300 | * ensure that reads are stable, as we cannot rely on userspace always | |
2301 | * being a good citizen. If members of the sqe are validated and then later | |
2302 | * used, it's important that those reads are done through READ_ONCE() to | |
2303 | * prevent a re-load down the line. | |
2304 | */ | |
2305 | static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s) | |
2306 | { | |
75b28aff HV |
2307 | struct io_rings *rings = ctx->rings; |
2308 | u32 *sq_array = ctx->sq_array; | |
2b188cc1 JA |
2309 | unsigned head; |
2310 | ||
2311 | /* | |
2312 | * The cached sq head (or cq tail) serves two purposes: | |
2313 | * | |
2314 | * 1) allows us to batch the cost of updating the user visible | |
2315 | * head updates. | |
2316 | * 2) allows the kernel side to track the head on its own, even | |
2317 | * though the application is the one updating it. | |
2318 | */ | |
2319 | head = ctx->cached_sq_head; | |
e523a29c | 2320 | /* make sure SQ entry isn't read before tail */ |
75b28aff | 2321 | if (head == smp_load_acquire(&rings->sq.tail)) |
2b188cc1 JA |
2322 | return false; |
2323 | ||
75b28aff | 2324 | head = READ_ONCE(sq_array[head & ctx->sq_mask]); |
2b188cc1 JA |
2325 | if (head < ctx->sq_entries) { |
2326 | s->index = head; | |
2327 | s->sqe = &ctx->sq_sqes[head]; | |
8776f3fa | 2328 | s->sequence = ctx->cached_sq_head; |
2b188cc1 JA |
2329 | ctx->cached_sq_head++; |
2330 | return true; | |
2331 | } | |
2332 | ||
2333 | /* drop invalid entries */ | |
2334 | ctx->cached_sq_head++; | |
75b28aff | 2335 | rings->sq_dropped++; |
2b188cc1 JA |
2336 | return false; |
2337 | } | |
2338 | ||
6c271ce2 JA |
2339 | static int io_submit_sqes(struct io_ring_ctx *ctx, struct sqe_submit *sqes, |
2340 | unsigned int nr, bool has_user, bool mm_fault) | |
2341 | { | |
2342 | struct io_submit_state state, *statep = NULL; | |
9e645e11 | 2343 | struct io_kiocb *link = NULL; |
4fe2c963 | 2344 | struct io_kiocb *shadow_req = NULL; |
9e645e11 JA |
2345 | bool prev_was_link = false; |
2346 | int i, submitted = 0; | |
6c271ce2 JA |
2347 | |
2348 | if (nr > IO_PLUG_THRESHOLD) { | |
2349 | io_submit_state_start(&state, ctx, nr); | |
2350 | statep = &state; | |
2351 | } | |
2352 | ||
2353 | for (i = 0; i < nr; i++) { | |
9e645e11 JA |
2354 | /* |
2355 | * If previous wasn't linked and we have a linked command, | |
2356 | * that's the end of the chain. Submit the previous link. | |
2357 | */ | |
2358 | if (!prev_was_link && link) { | |
c5766668 JA |
2359 | io_queue_link_head(ctx, link, &link->submit, shadow_req, |
2360 | true); | |
9e645e11 JA |
2361 | link = NULL; |
2362 | } | |
2363 | prev_was_link = (sqes[i].sqe->flags & IOSQE_IO_LINK) != 0; | |
2364 | ||
4fe2c963 JL |
2365 | if (link && (sqes[i].sqe->flags & IOSQE_IO_DRAIN)) { |
2366 | if (!shadow_req) { | |
2367 | shadow_req = io_get_req(ctx, NULL); | |
2368 | shadow_req->flags |= (REQ_F_IO_DRAIN | REQ_F_SHADOW_DRAIN); | |
2369 | refcount_dec(&shadow_req->refs); | |
2370 | } | |
2371 | shadow_req->sequence = sqes[i].sequence; | |
2372 | } | |
2373 | ||
6c271ce2 | 2374 | if (unlikely(mm_fault)) { |
9e645e11 JA |
2375 | io_cqring_add_event(ctx, sqes[i].sqe->user_data, |
2376 | -EFAULT); | |
6c271ce2 JA |
2377 | } else { |
2378 | sqes[i].has_user = has_user; | |
2379 | sqes[i].needs_lock = true; | |
2380 | sqes[i].needs_fixed_file = true; | |
c5766668 | 2381 | io_submit_sqe(ctx, &sqes[i], statep, &link, true); |
6c271ce2 | 2382 | submitted++; |
6c271ce2 | 2383 | } |
6c271ce2 JA |
2384 | } |
2385 | ||
9e645e11 | 2386 | if (link) |
c5766668 | 2387 | io_queue_link_head(ctx, link, &link->submit, shadow_req, true); |
6c271ce2 JA |
2388 | if (statep) |
2389 | io_submit_state_end(&state); | |
2390 | ||
2391 | return submitted; | |
2392 | } | |
2393 | ||
2394 | static int io_sq_thread(void *data) | |
2395 | { | |
2396 | struct sqe_submit sqes[IO_IOPOLL_BATCH]; | |
2397 | struct io_ring_ctx *ctx = data; | |
2398 | struct mm_struct *cur_mm = NULL; | |
2399 | mm_segment_t old_fs; | |
2400 | DEFINE_WAIT(wait); | |
2401 | unsigned inflight; | |
2402 | unsigned long timeout; | |
2403 | ||
a4c0b3de JL |
2404 | complete(&ctx->sqo_thread_started); |
2405 | ||
6c271ce2 JA |
2406 | old_fs = get_fs(); |
2407 | set_fs(USER_DS); | |
2408 | ||
2409 | timeout = inflight = 0; | |
2bbcd6d3 | 2410 | while (!kthread_should_park()) { |
6c271ce2 JA |
2411 | bool all_fixed, mm_fault = false; |
2412 | int i; | |
2413 | ||
2414 | if (inflight) { | |
2415 | unsigned nr_events = 0; | |
2416 | ||
2417 | if (ctx->flags & IORING_SETUP_IOPOLL) { | |
6c271ce2 | 2418 | io_iopoll_check(ctx, &nr_events, 0); |
6c271ce2 JA |
2419 | } else { |
2420 | /* | |
2421 | * Normal IO, just pretend everything completed. | |
2422 | * We don't have to poll completions for that. | |
2423 | */ | |
2424 | nr_events = inflight; | |
2425 | } | |
2426 | ||
2427 | inflight -= nr_events; | |
2428 | if (!inflight) | |
2429 | timeout = jiffies + ctx->sq_thread_idle; | |
2430 | } | |
2431 | ||
2432 | if (!io_get_sqring(ctx, &sqes[0])) { | |
2433 | /* | |
2434 | * We're polling. If we're within the defined idle | |
2435 | * period, then let us spin without work before going | |
2436 | * to sleep. | |
2437 | */ | |
2438 | if (inflight || !time_after(jiffies, timeout)) { | |
2439 | cpu_relax(); | |
2440 | continue; | |
2441 | } | |
2442 | ||
2443 | /* | |
2444 | * Drop cur_mm before scheduling, we can't hold it for | |
2445 | * long periods (or over schedule()). Do this before | |
2446 | * adding ourselves to the waitqueue, as the unuse/drop | |
2447 | * may sleep. | |
2448 | */ | |
2449 | if (cur_mm) { | |
2450 | unuse_mm(cur_mm); | |
2451 | mmput(cur_mm); | |
2452 | cur_mm = NULL; | |
2453 | } | |
2454 | ||
2455 | prepare_to_wait(&ctx->sqo_wait, &wait, | |
2456 | TASK_INTERRUPTIBLE); | |
2457 | ||
2458 | /* Tell userspace we may need a wakeup call */ | |
75b28aff | 2459 | ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP; |
0d7bae69 SB |
2460 | /* make sure to read SQ tail after writing flags */ |
2461 | smp_mb(); | |
6c271ce2 JA |
2462 | |
2463 | if (!io_get_sqring(ctx, &sqes[0])) { | |
2bbcd6d3 | 2464 | if (kthread_should_park()) { |
6c271ce2 JA |
2465 | finish_wait(&ctx->sqo_wait, &wait); |
2466 | break; | |
2467 | } | |
2468 | if (signal_pending(current)) | |
2469 | flush_signals(current); | |
2470 | schedule(); | |
2471 | finish_wait(&ctx->sqo_wait, &wait); | |
2472 | ||
75b28aff | 2473 | ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; |
6c271ce2 JA |
2474 | continue; |
2475 | } | |
2476 | finish_wait(&ctx->sqo_wait, &wait); | |
2477 | ||
75b28aff | 2478 | ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP; |
6c271ce2 JA |
2479 | } |
2480 | ||
2481 | i = 0; | |
2482 | all_fixed = true; | |
2483 | do { | |
2484 | if (all_fixed && io_sqe_needs_user(sqes[i].sqe)) | |
2485 | all_fixed = false; | |
2486 | ||
2487 | i++; | |
2488 | if (i == ARRAY_SIZE(sqes)) | |
2489 | break; | |
2490 | } while (io_get_sqring(ctx, &sqes[i])); | |
2491 | ||
2492 | /* Unless all new commands are FIXED regions, grab mm */ | |
2493 | if (!all_fixed && !cur_mm) { | |
2494 | mm_fault = !mmget_not_zero(ctx->sqo_mm); | |
2495 | if (!mm_fault) { | |
2496 | use_mm(ctx->sqo_mm); | |
2497 | cur_mm = ctx->sqo_mm; | |
2498 | } | |
2499 | } | |
2500 | ||
2501 | inflight += io_submit_sqes(ctx, sqes, i, cur_mm != NULL, | |
2502 | mm_fault); | |
2503 | ||
2504 | /* Commit SQ ring head once we've consumed all SQEs */ | |
2505 | io_commit_sqring(ctx); | |
2506 | } | |
2507 | ||
2508 | set_fs(old_fs); | |
2509 | if (cur_mm) { | |
2510 | unuse_mm(cur_mm); | |
2511 | mmput(cur_mm); | |
2512 | } | |
06058632 | 2513 | |
2bbcd6d3 | 2514 | kthread_parkme(); |
06058632 | 2515 | |
6c271ce2 JA |
2516 | return 0; |
2517 | } | |
2518 | ||
c5766668 JA |
2519 | static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit, |
2520 | bool block_for_last) | |
2b188cc1 | 2521 | { |
9a56a232 | 2522 | struct io_submit_state state, *statep = NULL; |
9e645e11 | 2523 | struct io_kiocb *link = NULL; |
4fe2c963 | 2524 | struct io_kiocb *shadow_req = NULL; |
9e645e11 | 2525 | bool prev_was_link = false; |
5c8b0b54 | 2526 | int i, submit = 0; |
2b188cc1 | 2527 | |
9a56a232 JA |
2528 | if (to_submit > IO_PLUG_THRESHOLD) { |
2529 | io_submit_state_start(&state, ctx, to_submit); | |
2530 | statep = &state; | |
2531 | } | |
2b188cc1 JA |
2532 | |
2533 | for (i = 0; i < to_submit; i++) { | |
c5766668 | 2534 | bool force_nonblock = true; |
2b188cc1 JA |
2535 | struct sqe_submit s; |
2536 | ||
2537 | if (!io_get_sqring(ctx, &s)) | |
2538 | break; | |
2539 | ||
9e645e11 JA |
2540 | /* |
2541 | * If previous wasn't linked and we have a linked command, | |
2542 | * that's the end of the chain. Submit the previous link. | |
2543 | */ | |
2544 | if (!prev_was_link && link) { | |
c5766668 JA |
2545 | io_queue_link_head(ctx, link, &link->submit, shadow_req, |
2546 | force_nonblock); | |
9e645e11 JA |
2547 | link = NULL; |
2548 | } | |
2549 | prev_was_link = (s.sqe->flags & IOSQE_IO_LINK) != 0; | |
2550 | ||
4fe2c963 JL |
2551 | if (link && (s.sqe->flags & IOSQE_IO_DRAIN)) { |
2552 | if (!shadow_req) { | |
2553 | shadow_req = io_get_req(ctx, NULL); | |
2554 | shadow_req->flags |= (REQ_F_IO_DRAIN | REQ_F_SHADOW_DRAIN); | |
2555 | refcount_dec(&shadow_req->refs); | |
2556 | } | |
2557 | shadow_req->sequence = s.sequence; | |
2558 | } | |
2559 | ||
2b188cc1 | 2560 | s.has_user = true; |
def596e9 | 2561 | s.needs_lock = false; |
6c271ce2 | 2562 | s.needs_fixed_file = false; |
5c8b0b54 | 2563 | submit++; |
c5766668 JA |
2564 | |
2565 | /* | |
2566 | * The caller will block for events after submit, submit the | |
2567 | * last IO non-blocking. This is either the only IO it's | |
2568 | * submitting, or it already submitted the previous ones. This | |
2569 | * improves performance by avoiding an async punt that we don't | |
2570 | * need to do. | |
2571 | */ | |
2572 | if (block_for_last && submit == to_submit) | |
2573 | force_nonblock = false; | |
2574 | ||
2575 | io_submit_sqe(ctx, &s, statep, &link, force_nonblock); | |
2b188cc1 JA |
2576 | } |
2577 | io_commit_sqring(ctx); | |
2578 | ||
9e645e11 | 2579 | if (link) |
c5766668 JA |
2580 | io_queue_link_head(ctx, link, &link->submit, shadow_req, |
2581 | block_for_last); | |
9a56a232 JA |
2582 | if (statep) |
2583 | io_submit_state_end(statep); | |
2b188cc1 | 2584 | |
5c8b0b54 | 2585 | return submit; |
2b188cc1 JA |
2586 | } |
2587 | ||
2b188cc1 JA |
2588 | /* |
2589 | * Wait until events become available, if we don't already have some. The | |
2590 | * application must reap them itself, as they reside on the shared cq ring. | |
2591 | */ | |
2592 | static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, | |
2593 | const sigset_t __user *sig, size_t sigsz) | |
2594 | { | |
75b28aff | 2595 | struct io_rings *rings = ctx->rings; |
2b188cc1 JA |
2596 | int ret; |
2597 | ||
75b28aff | 2598 | if (io_cqring_events(rings) >= min_events) |
2b188cc1 JA |
2599 | return 0; |
2600 | ||
2601 | if (sig) { | |
9e75ad5d AB |
2602 | #ifdef CONFIG_COMPAT |
2603 | if (in_compat_syscall()) | |
2604 | ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig, | |
b772434b | 2605 | sigsz); |
9e75ad5d AB |
2606 | else |
2607 | #endif | |
b772434b | 2608 | ret = set_user_sigmask(sig, sigsz); |
9e75ad5d | 2609 | |
2b188cc1 JA |
2610 | if (ret) |
2611 | return ret; | |
2612 | } | |
2613 | ||
75b28aff | 2614 | ret = wait_event_interruptible(ctx->wait, io_cqring_events(rings) >= min_events); |
b772434b | 2615 | restore_saved_sigmask_unless(ret == -ERESTARTSYS); |
97abc889 ON |
2616 | if (ret == -ERESTARTSYS) |
2617 | ret = -EINTR; | |
2b188cc1 | 2618 | |
75b28aff | 2619 | return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; |
2b188cc1 JA |
2620 | } |
2621 | ||
6b06314c JA |
2622 | static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) |
2623 | { | |
2624 | #if defined(CONFIG_UNIX) | |
2625 | if (ctx->ring_sock) { | |
2626 | struct sock *sock = ctx->ring_sock->sk; | |
2627 | struct sk_buff *skb; | |
2628 | ||
2629 | while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL) | |
2630 | kfree_skb(skb); | |
2631 | } | |
2632 | #else | |
2633 | int i; | |
2634 | ||
2635 | for (i = 0; i < ctx->nr_user_files; i++) | |
2636 | fput(ctx->user_files[i]); | |
2637 | #endif | |
2638 | } | |
2639 | ||
2640 | static int io_sqe_files_unregister(struct io_ring_ctx *ctx) | |
2641 | { | |
2642 | if (!ctx->user_files) | |
2643 | return -ENXIO; | |
2644 | ||
2645 | __io_sqe_files_unregister(ctx); | |
2646 | kfree(ctx->user_files); | |
2647 | ctx->user_files = NULL; | |
2648 | ctx->nr_user_files = 0; | |
2649 | return 0; | |
2650 | } | |
2651 | ||
6c271ce2 JA |
2652 | static void io_sq_thread_stop(struct io_ring_ctx *ctx) |
2653 | { | |
2654 | if (ctx->sqo_thread) { | |
a4c0b3de | 2655 | wait_for_completion(&ctx->sqo_thread_started); |
2bbcd6d3 RP |
2656 | /* |
2657 | * The park is a bit of a work-around, without it we get | |
2658 | * warning spews on shutdown with SQPOLL set and affinity | |
2659 | * set to a single CPU. | |
2660 | */ | |
06058632 | 2661 | kthread_park(ctx->sqo_thread); |
6c271ce2 JA |
2662 | kthread_stop(ctx->sqo_thread); |
2663 | ctx->sqo_thread = NULL; | |
2664 | } | |
2665 | } | |
2666 | ||
6b06314c JA |
2667 | static void io_finish_async(struct io_ring_ctx *ctx) |
2668 | { | |
54a91f3b JA |
2669 | int i; |
2670 | ||
6c271ce2 JA |
2671 | io_sq_thread_stop(ctx); |
2672 | ||
54a91f3b JA |
2673 | for (i = 0; i < ARRAY_SIZE(ctx->sqo_wq); i++) { |
2674 | if (ctx->sqo_wq[i]) { | |
2675 | destroy_workqueue(ctx->sqo_wq[i]); | |
2676 | ctx->sqo_wq[i] = NULL; | |
2677 | } | |
6b06314c JA |
2678 | } |
2679 | } | |
2680 | ||
2681 | #if defined(CONFIG_UNIX) | |
2682 | static void io_destruct_skb(struct sk_buff *skb) | |
2683 | { | |
2684 | struct io_ring_ctx *ctx = skb->sk->sk_user_data; | |
2685 | ||
2686 | io_finish_async(ctx); | |
2687 | unix_destruct_scm(skb); | |
2688 | } | |
2689 | ||
2690 | /* | |
2691 | * Ensure the UNIX gc is aware of our file set, so we are certain that | |
2692 | * the io_uring can be safely unregistered on process exit, even if we have | |
2693 | * loops in the file referencing. | |
2694 | */ | |
2695 | static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset) | |
2696 | { | |
2697 | struct sock *sk = ctx->ring_sock->sk; | |
2698 | struct scm_fp_list *fpl; | |
2699 | struct sk_buff *skb; | |
2700 | int i; | |
2701 | ||
2702 | if (!capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) { | |
2703 | unsigned long inflight = ctx->user->unix_inflight + nr; | |
2704 | ||
2705 | if (inflight > task_rlimit(current, RLIMIT_NOFILE)) | |
2706 | return -EMFILE; | |
2707 | } | |
2708 | ||
2709 | fpl = kzalloc(sizeof(*fpl), GFP_KERNEL); | |
2710 | if (!fpl) | |
2711 | return -ENOMEM; | |
2712 | ||
2713 | skb = alloc_skb(0, GFP_KERNEL); | |
2714 | if (!skb) { | |
2715 | kfree(fpl); | |
2716 | return -ENOMEM; | |
2717 | } | |
2718 | ||
2719 | skb->sk = sk; | |
2720 | skb->destructor = io_destruct_skb; | |
2721 | ||
2722 | fpl->user = get_uid(ctx->user); | |
2723 | for (i = 0; i < nr; i++) { | |
2724 | fpl->fp[i] = get_file(ctx->user_files[i + offset]); | |
2725 | unix_inflight(fpl->user, fpl->fp[i]); | |
2726 | } | |
2727 | ||
2728 | fpl->max = fpl->count = nr; | |
2729 | UNIXCB(skb).fp = fpl; | |
2730 | refcount_add(skb->truesize, &sk->sk_wmem_alloc); | |
2731 | skb_queue_head(&sk->sk_receive_queue, skb); | |
2732 | ||
2733 | for (i = 0; i < nr; i++) | |
2734 | fput(fpl->fp[i]); | |
2735 | ||
2736 | return 0; | |
2737 | } | |
2738 | ||
2739 | /* | |
2740 | * If UNIX sockets are enabled, fd passing can cause a reference cycle which | |
2741 | * causes regular reference counting to break down. We rely on the UNIX | |
2742 | * garbage collection to take care of this problem for us. | |
2743 | */ | |
2744 | static int io_sqe_files_scm(struct io_ring_ctx *ctx) | |
2745 | { | |
2746 | unsigned left, total; | |
2747 | int ret = 0; | |
2748 | ||
2749 | total = 0; | |
2750 | left = ctx->nr_user_files; | |
2751 | while (left) { | |
2752 | unsigned this_files = min_t(unsigned, left, SCM_MAX_FD); | |
6b06314c JA |
2753 | |
2754 | ret = __io_sqe_files_scm(ctx, this_files, total); | |
2755 | if (ret) | |
2756 | break; | |
2757 | left -= this_files; | |
2758 | total += this_files; | |
2759 | } | |
2760 | ||
2761 | if (!ret) | |
2762 | return 0; | |
2763 | ||
2764 | while (total < ctx->nr_user_files) { | |
2765 | fput(ctx->user_files[total]); | |
2766 | total++; | |
2767 | } | |
2768 | ||
2769 | return ret; | |
2770 | } | |
2771 | #else | |
2772 | static int io_sqe_files_scm(struct io_ring_ctx *ctx) | |
2773 | { | |
2774 | return 0; | |
2775 | } | |
2776 | #endif | |
2777 | ||
2778 | static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg, | |
2779 | unsigned nr_args) | |
2780 | { | |
2781 | __s32 __user *fds = (__s32 __user *) arg; | |
2782 | int fd, ret = 0; | |
2783 | unsigned i; | |
2784 | ||
2785 | if (ctx->user_files) | |
2786 | return -EBUSY; | |
2787 | if (!nr_args) | |
2788 | return -EINVAL; | |
2789 | if (nr_args > IORING_MAX_FIXED_FILES) | |
2790 | return -EMFILE; | |
2791 | ||
2792 | ctx->user_files = kcalloc(nr_args, sizeof(struct file *), GFP_KERNEL); | |
2793 | if (!ctx->user_files) | |
2794 | return -ENOMEM; | |
2795 | ||
2796 | for (i = 0; i < nr_args; i++) { | |
2797 | ret = -EFAULT; | |
2798 | if (copy_from_user(&fd, &fds[i], sizeof(fd))) | |
2799 | break; | |
2800 | ||
2801 | ctx->user_files[i] = fget(fd); | |
2802 | ||
2803 | ret = -EBADF; | |
2804 | if (!ctx->user_files[i]) | |
2805 | break; | |
2806 | /* | |
2807 | * Don't allow io_uring instances to be registered. If UNIX | |
2808 | * isn't enabled, then this causes a reference cycle and this | |
2809 | * instance can never get freed. If UNIX is enabled we'll | |
2810 | * handle it just fine, but there's still no point in allowing | |
2811 | * a ring fd as it doesn't support regular read/write anyway. | |
2812 | */ | |
2813 | if (ctx->user_files[i]->f_op == &io_uring_fops) { | |
2814 | fput(ctx->user_files[i]); | |
2815 | break; | |
2816 | } | |
2817 | ctx->nr_user_files++; | |
2818 | ret = 0; | |
2819 | } | |
2820 | ||
2821 | if (ret) { | |
2822 | for (i = 0; i < ctx->nr_user_files; i++) | |
2823 | fput(ctx->user_files[i]); | |
2824 | ||
2825 | kfree(ctx->user_files); | |
25adf50f | 2826 | ctx->user_files = NULL; |
6b06314c JA |
2827 | ctx->nr_user_files = 0; |
2828 | return ret; | |
2829 | } | |
2830 | ||
2831 | ret = io_sqe_files_scm(ctx); | |
2832 | if (ret) | |
2833 | io_sqe_files_unregister(ctx); | |
2834 | ||
2835 | return ret; | |
2836 | } | |
2837 | ||
6c271ce2 JA |
2838 | static int io_sq_offload_start(struct io_ring_ctx *ctx, |
2839 | struct io_uring_params *p) | |
2b188cc1 JA |
2840 | { |
2841 | int ret; | |
2842 | ||
6c271ce2 | 2843 | init_waitqueue_head(&ctx->sqo_wait); |
2b188cc1 JA |
2844 | mmgrab(current->mm); |
2845 | ctx->sqo_mm = current->mm; | |
2846 | ||
6c271ce2 | 2847 | if (ctx->flags & IORING_SETUP_SQPOLL) { |
3ec482d1 JA |
2848 | ret = -EPERM; |
2849 | if (!capable(CAP_SYS_ADMIN)) | |
2850 | goto err; | |
2851 | ||
917257da JA |
2852 | ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle); |
2853 | if (!ctx->sq_thread_idle) | |
2854 | ctx->sq_thread_idle = HZ; | |
2855 | ||
6c271ce2 | 2856 | if (p->flags & IORING_SETUP_SQ_AFF) { |
44a9bd18 | 2857 | int cpu = p->sq_thread_cpu; |
6c271ce2 | 2858 | |
917257da | 2859 | ret = -EINVAL; |
44a9bd18 JA |
2860 | if (cpu >= nr_cpu_ids) |
2861 | goto err; | |
7889f44d | 2862 | if (!cpu_online(cpu)) |
917257da JA |
2863 | goto err; |
2864 | ||
6c271ce2 JA |
2865 | ctx->sqo_thread = kthread_create_on_cpu(io_sq_thread, |
2866 | ctx, cpu, | |
2867 | "io_uring-sq"); | |
2868 | } else { | |
2869 | ctx->sqo_thread = kthread_create(io_sq_thread, ctx, | |
2870 | "io_uring-sq"); | |
2871 | } | |
2872 | if (IS_ERR(ctx->sqo_thread)) { | |
2873 | ret = PTR_ERR(ctx->sqo_thread); | |
2874 | ctx->sqo_thread = NULL; | |
2875 | goto err; | |
2876 | } | |
2877 | wake_up_process(ctx->sqo_thread); | |
2878 | } else if (p->flags & IORING_SETUP_SQ_AFF) { | |
2879 | /* Can't have SQ_AFF without SQPOLL */ | |
2880 | ret = -EINVAL; | |
2881 | goto err; | |
2882 | } | |
2883 | ||
2b188cc1 | 2884 | /* Do QD, or 2 * CPUS, whatever is smallest */ |
54a91f3b JA |
2885 | ctx->sqo_wq[0] = alloc_workqueue("io_ring-wq", |
2886 | WQ_UNBOUND | WQ_FREEZABLE, | |
2b188cc1 | 2887 | min(ctx->sq_entries - 1, 2 * num_online_cpus())); |
54a91f3b JA |
2888 | if (!ctx->sqo_wq[0]) { |
2889 | ret = -ENOMEM; | |
2890 | goto err; | |
2891 | } | |
2892 | ||
2893 | /* | |
2894 | * This is for buffered writes, where we want to limit the parallelism | |
2895 | * due to file locking in file systems. As "normal" buffered writes | |
2896 | * should parellelize on writeout quite nicely, limit us to having 2 | |
2897 | * pending. This avoids massive contention on the inode when doing | |
2898 | * buffered async writes. | |
2899 | */ | |
2900 | ctx->sqo_wq[1] = alloc_workqueue("io_ring-write-wq", | |
2901 | WQ_UNBOUND | WQ_FREEZABLE, 2); | |
2902 | if (!ctx->sqo_wq[1]) { | |
2b188cc1 JA |
2903 | ret = -ENOMEM; |
2904 | goto err; | |
2905 | } | |
2906 | ||
2907 | return 0; | |
2908 | err: | |
54a91f3b | 2909 | io_finish_async(ctx); |
2b188cc1 JA |
2910 | mmdrop(ctx->sqo_mm); |
2911 | ctx->sqo_mm = NULL; | |
2912 | return ret; | |
2913 | } | |
2914 | ||
2915 | static void io_unaccount_mem(struct user_struct *user, unsigned long nr_pages) | |
2916 | { | |
2917 | atomic_long_sub(nr_pages, &user->locked_vm); | |
2918 | } | |
2919 | ||
2920 | static int io_account_mem(struct user_struct *user, unsigned long nr_pages) | |
2921 | { | |
2922 | unsigned long page_limit, cur_pages, new_pages; | |
2923 | ||
2924 | /* Don't allow more pages than we can safely lock */ | |
2925 | page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; | |
2926 | ||
2927 | do { | |
2928 | cur_pages = atomic_long_read(&user->locked_vm); | |
2929 | new_pages = cur_pages + nr_pages; | |
2930 | if (new_pages > page_limit) | |
2931 | return -ENOMEM; | |
2932 | } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages, | |
2933 | new_pages) != cur_pages); | |
2934 | ||
2935 | return 0; | |
2936 | } | |
2937 | ||
2938 | static void io_mem_free(void *ptr) | |
2939 | { | |
52e04ef4 MR |
2940 | struct page *page; |
2941 | ||
2942 | if (!ptr) | |
2943 | return; | |
2b188cc1 | 2944 | |
52e04ef4 | 2945 | page = virt_to_head_page(ptr); |
2b188cc1 JA |
2946 | if (put_page_testzero(page)) |
2947 | free_compound_page(page); | |
2948 | } | |
2949 | ||
2950 | static void *io_mem_alloc(size_t size) | |
2951 | { | |
2952 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP | | |
2953 | __GFP_NORETRY; | |
2954 | ||
2955 | return (void *) __get_free_pages(gfp_flags, get_order(size)); | |
2956 | } | |
2957 | ||
75b28aff HV |
2958 | static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries, |
2959 | size_t *sq_offset) | |
2960 | { | |
2961 | struct io_rings *rings; | |
2962 | size_t off, sq_array_size; | |
2963 | ||
2964 | off = struct_size(rings, cqes, cq_entries); | |
2965 | if (off == SIZE_MAX) | |
2966 | return SIZE_MAX; | |
2967 | ||
2968 | #ifdef CONFIG_SMP | |
2969 | off = ALIGN(off, SMP_CACHE_BYTES); | |
2970 | if (off == 0) | |
2971 | return SIZE_MAX; | |
2972 | #endif | |
2973 | ||
2974 | sq_array_size = array_size(sizeof(u32), sq_entries); | |
2975 | if (sq_array_size == SIZE_MAX) | |
2976 | return SIZE_MAX; | |
2977 | ||
2978 | if (check_add_overflow(off, sq_array_size, &off)) | |
2979 | return SIZE_MAX; | |
2980 | ||
2981 | if (sq_offset) | |
2982 | *sq_offset = off; | |
2983 | ||
2984 | return off; | |
2985 | } | |
2986 | ||
2b188cc1 JA |
2987 | static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries) |
2988 | { | |
75b28aff | 2989 | size_t pages; |
2b188cc1 | 2990 | |
75b28aff HV |
2991 | pages = (size_t)1 << get_order( |
2992 | rings_size(sq_entries, cq_entries, NULL)); | |
2993 | pages += (size_t)1 << get_order( | |
2994 | array_size(sizeof(struct io_uring_sqe), sq_entries)); | |
2b188cc1 | 2995 | |
75b28aff | 2996 | return pages; |
2b188cc1 JA |
2997 | } |
2998 | ||
edafccee JA |
2999 | static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx) |
3000 | { | |
3001 | int i, j; | |
3002 | ||
3003 | if (!ctx->user_bufs) | |
3004 | return -ENXIO; | |
3005 | ||
3006 | for (i = 0; i < ctx->nr_user_bufs; i++) { | |
3007 | struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; | |
3008 | ||
3009 | for (j = 0; j < imu->nr_bvecs; j++) | |
27c4d3a3 | 3010 | put_user_page(imu->bvec[j].bv_page); |
edafccee JA |
3011 | |
3012 | if (ctx->account_mem) | |
3013 | io_unaccount_mem(ctx->user, imu->nr_bvecs); | |
d4ef6475 | 3014 | kvfree(imu->bvec); |
edafccee JA |
3015 | imu->nr_bvecs = 0; |
3016 | } | |
3017 | ||
3018 | kfree(ctx->user_bufs); | |
3019 | ctx->user_bufs = NULL; | |
3020 | ctx->nr_user_bufs = 0; | |
3021 | return 0; | |
3022 | } | |
3023 | ||
3024 | static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst, | |
3025 | void __user *arg, unsigned index) | |
3026 | { | |
3027 | struct iovec __user *src; | |
3028 | ||
3029 | #ifdef CONFIG_COMPAT | |
3030 | if (ctx->compat) { | |
3031 | struct compat_iovec __user *ciovs; | |
3032 | struct compat_iovec ciov; | |
3033 | ||
3034 | ciovs = (struct compat_iovec __user *) arg; | |
3035 | if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov))) | |
3036 | return -EFAULT; | |
3037 | ||
3038 | dst->iov_base = (void __user *) (unsigned long) ciov.iov_base; | |
3039 | dst->iov_len = ciov.iov_len; | |
3040 | return 0; | |
3041 | } | |
3042 | #endif | |
3043 | src = (struct iovec __user *) arg; | |
3044 | if (copy_from_user(dst, &src[index], sizeof(*dst))) | |
3045 | return -EFAULT; | |
3046 | return 0; | |
3047 | } | |
3048 | ||
3049 | static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg, | |
3050 | unsigned nr_args) | |
3051 | { | |
3052 | struct vm_area_struct **vmas = NULL; | |
3053 | struct page **pages = NULL; | |
3054 | int i, j, got_pages = 0; | |
3055 | int ret = -EINVAL; | |
3056 | ||
3057 | if (ctx->user_bufs) | |
3058 | return -EBUSY; | |
3059 | if (!nr_args || nr_args > UIO_MAXIOV) | |
3060 | return -EINVAL; | |
3061 | ||
3062 | ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf), | |
3063 | GFP_KERNEL); | |
3064 | if (!ctx->user_bufs) | |
3065 | return -ENOMEM; | |
3066 | ||
3067 | for (i = 0; i < nr_args; i++) { | |
3068 | struct io_mapped_ubuf *imu = &ctx->user_bufs[i]; | |
3069 | unsigned long off, start, end, ubuf; | |
3070 | int pret, nr_pages; | |
3071 | struct iovec iov; | |
3072 | size_t size; | |
3073 | ||
3074 | ret = io_copy_iov(ctx, &iov, arg, i); | |
3075 | if (ret) | |
a278682d | 3076 | goto err; |
edafccee JA |
3077 | |
3078 | /* | |
3079 | * Don't impose further limits on the size and buffer | |
3080 | * constraints here, we'll -EINVAL later when IO is | |
3081 | * submitted if they are wrong. | |
3082 | */ | |
3083 | ret = -EFAULT; | |
3084 | if (!iov.iov_base || !iov.iov_len) | |
3085 | goto err; | |
3086 | ||
3087 | /* arbitrary limit, but we need something */ | |
3088 | if (iov.iov_len > SZ_1G) | |
3089 | goto err; | |
3090 | ||
3091 | ubuf = (unsigned long) iov.iov_base; | |
3092 | end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
3093 | start = ubuf >> PAGE_SHIFT; | |
3094 | nr_pages = end - start; | |
3095 | ||
3096 | if (ctx->account_mem) { | |
3097 | ret = io_account_mem(ctx->user, nr_pages); | |
3098 | if (ret) | |
3099 | goto err; | |
3100 | } | |
3101 | ||
3102 | ret = 0; | |
3103 | if (!pages || nr_pages > got_pages) { | |
3104 | kfree(vmas); | |
3105 | kfree(pages); | |
d4ef6475 | 3106 | pages = kvmalloc_array(nr_pages, sizeof(struct page *), |
edafccee | 3107 | GFP_KERNEL); |
d4ef6475 | 3108 | vmas = kvmalloc_array(nr_pages, |
edafccee JA |
3109 | sizeof(struct vm_area_struct *), |
3110 | GFP_KERNEL); | |
3111 | if (!pages || !vmas) { | |
3112 | ret = -ENOMEM; | |
3113 | if (ctx->account_mem) | |
3114 | io_unaccount_mem(ctx->user, nr_pages); | |
3115 | goto err; | |
3116 | } | |
3117 | got_pages = nr_pages; | |
3118 | } | |
3119 | ||
d4ef6475 | 3120 | imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec), |
edafccee JA |
3121 | GFP_KERNEL); |
3122 | ret = -ENOMEM; | |
3123 | if (!imu->bvec) { | |
3124 | if (ctx->account_mem) | |
3125 | io_unaccount_mem(ctx->user, nr_pages); | |
3126 | goto err; | |
3127 | } | |
3128 | ||
3129 | ret = 0; | |
3130 | down_read(¤t->mm->mmap_sem); | |
932f4a63 IW |
3131 | pret = get_user_pages(ubuf, nr_pages, |
3132 | FOLL_WRITE | FOLL_LONGTERM, | |
3133 | pages, vmas); | |
edafccee JA |
3134 | if (pret == nr_pages) { |
3135 | /* don't support file backed memory */ | |
3136 | for (j = 0; j < nr_pages; j++) { | |
3137 | struct vm_area_struct *vma = vmas[j]; | |
3138 | ||
3139 | if (vma->vm_file && | |
3140 | !is_file_hugepages(vma->vm_file)) { | |
3141 | ret = -EOPNOTSUPP; | |
3142 | break; | |
3143 | } | |
3144 | } | |
3145 | } else { | |
3146 | ret = pret < 0 ? pret : -EFAULT; | |
3147 | } | |
3148 | up_read(¤t->mm->mmap_sem); | |
3149 | if (ret) { | |
3150 | /* | |
3151 | * if we did partial map, or found file backed vmas, | |
3152 | * release any pages we did get | |
3153 | */ | |
27c4d3a3 JH |
3154 | if (pret > 0) |
3155 | put_user_pages(pages, pret); | |
edafccee JA |
3156 | if (ctx->account_mem) |
3157 | io_unaccount_mem(ctx->user, nr_pages); | |
d4ef6475 | 3158 | kvfree(imu->bvec); |
edafccee JA |
3159 | goto err; |
3160 | } | |
3161 | ||
3162 | off = ubuf & ~PAGE_MASK; | |
3163 | size = iov.iov_len; | |
3164 | for (j = 0; j < nr_pages; j++) { | |
3165 | size_t vec_len; | |
3166 | ||
3167 | vec_len = min_t(size_t, size, PAGE_SIZE - off); | |
3168 | imu->bvec[j].bv_page = pages[j]; | |
3169 | imu->bvec[j].bv_len = vec_len; | |
3170 | imu->bvec[j].bv_offset = off; | |
3171 | off = 0; | |
3172 | size -= vec_len; | |
3173 | } | |
3174 | /* store original address for later verification */ | |
3175 | imu->ubuf = ubuf; | |
3176 | imu->len = iov.iov_len; | |
3177 | imu->nr_bvecs = nr_pages; | |
3178 | ||
3179 | ctx->nr_user_bufs++; | |
3180 | } | |
d4ef6475 MR |
3181 | kvfree(pages); |
3182 | kvfree(vmas); | |
edafccee JA |
3183 | return 0; |
3184 | err: | |
d4ef6475 MR |
3185 | kvfree(pages); |
3186 | kvfree(vmas); | |
edafccee JA |
3187 | io_sqe_buffer_unregister(ctx); |
3188 | return ret; | |
3189 | } | |
3190 | ||
9b402849 JA |
3191 | static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg) |
3192 | { | |
3193 | __s32 __user *fds = arg; | |
3194 | int fd; | |
3195 | ||
3196 | if (ctx->cq_ev_fd) | |
3197 | return -EBUSY; | |
3198 | ||
3199 | if (copy_from_user(&fd, fds, sizeof(*fds))) | |
3200 | return -EFAULT; | |
3201 | ||
3202 | ctx->cq_ev_fd = eventfd_ctx_fdget(fd); | |
3203 | if (IS_ERR(ctx->cq_ev_fd)) { | |
3204 | int ret = PTR_ERR(ctx->cq_ev_fd); | |
3205 | ctx->cq_ev_fd = NULL; | |
3206 | return ret; | |
3207 | } | |
3208 | ||
3209 | return 0; | |
3210 | } | |
3211 | ||
3212 | static int io_eventfd_unregister(struct io_ring_ctx *ctx) | |
3213 | { | |
3214 | if (ctx->cq_ev_fd) { | |
3215 | eventfd_ctx_put(ctx->cq_ev_fd); | |
3216 | ctx->cq_ev_fd = NULL; | |
3217 | return 0; | |
3218 | } | |
3219 | ||
3220 | return -ENXIO; | |
3221 | } | |
3222 | ||
2b188cc1 JA |
3223 | static void io_ring_ctx_free(struct io_ring_ctx *ctx) |
3224 | { | |
6b06314c | 3225 | io_finish_async(ctx); |
2b188cc1 JA |
3226 | if (ctx->sqo_mm) |
3227 | mmdrop(ctx->sqo_mm); | |
def596e9 JA |
3228 | |
3229 | io_iopoll_reap_events(ctx); | |
edafccee | 3230 | io_sqe_buffer_unregister(ctx); |
6b06314c | 3231 | io_sqe_files_unregister(ctx); |
9b402849 | 3232 | io_eventfd_unregister(ctx); |
def596e9 | 3233 | |
2b188cc1 | 3234 | #if defined(CONFIG_UNIX) |
355e8d26 EB |
3235 | if (ctx->ring_sock) { |
3236 | ctx->ring_sock->file = NULL; /* so that iput() is called */ | |
2b188cc1 | 3237 | sock_release(ctx->ring_sock); |
355e8d26 | 3238 | } |
2b188cc1 JA |
3239 | #endif |
3240 | ||
75b28aff | 3241 | io_mem_free(ctx->rings); |
2b188cc1 | 3242 | io_mem_free(ctx->sq_sqes); |
2b188cc1 JA |
3243 | |
3244 | percpu_ref_exit(&ctx->refs); | |
3245 | if (ctx->account_mem) | |
3246 | io_unaccount_mem(ctx->user, | |
3247 | ring_pages(ctx->sq_entries, ctx->cq_entries)); | |
3248 | free_uid(ctx->user); | |
3249 | kfree(ctx); | |
3250 | } | |
3251 | ||
3252 | static __poll_t io_uring_poll(struct file *file, poll_table *wait) | |
3253 | { | |
3254 | struct io_ring_ctx *ctx = file->private_data; | |
3255 | __poll_t mask = 0; | |
3256 | ||
3257 | poll_wait(file, &ctx->cq_wait, wait); | |
4f7067c3 SB |
3258 | /* |
3259 | * synchronizes with barrier from wq_has_sleeper call in | |
3260 | * io_commit_cqring | |
3261 | */ | |
2b188cc1 | 3262 | smp_rmb(); |
75b28aff HV |
3263 | if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head != |
3264 | ctx->rings->sq_ring_entries) | |
2b188cc1 | 3265 | mask |= EPOLLOUT | EPOLLWRNORM; |
75b28aff | 3266 | if (READ_ONCE(ctx->rings->sq.head) != ctx->cached_cq_tail) |
2b188cc1 JA |
3267 | mask |= EPOLLIN | EPOLLRDNORM; |
3268 | ||
3269 | return mask; | |
3270 | } | |
3271 | ||
3272 | static int io_uring_fasync(int fd, struct file *file, int on) | |
3273 | { | |
3274 | struct io_ring_ctx *ctx = file->private_data; | |
3275 | ||
3276 | return fasync_helper(fd, file, on, &ctx->cq_fasync); | |
3277 | } | |
3278 | ||
3279 | static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) | |
3280 | { | |
3281 | mutex_lock(&ctx->uring_lock); | |
3282 | percpu_ref_kill(&ctx->refs); | |
3283 | mutex_unlock(&ctx->uring_lock); | |
3284 | ||
221c5eb2 | 3285 | io_poll_remove_all(ctx); |
def596e9 | 3286 | io_iopoll_reap_events(ctx); |
2b188cc1 JA |
3287 | wait_for_completion(&ctx->ctx_done); |
3288 | io_ring_ctx_free(ctx); | |
3289 | } | |
3290 | ||
3291 | static int io_uring_release(struct inode *inode, struct file *file) | |
3292 | { | |
3293 | struct io_ring_ctx *ctx = file->private_data; | |
3294 | ||
3295 | file->private_data = NULL; | |
3296 | io_ring_ctx_wait_and_kill(ctx); | |
3297 | return 0; | |
3298 | } | |
3299 | ||
3300 | static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) | |
3301 | { | |
3302 | loff_t offset = (loff_t) vma->vm_pgoff << PAGE_SHIFT; | |
3303 | unsigned long sz = vma->vm_end - vma->vm_start; | |
3304 | struct io_ring_ctx *ctx = file->private_data; | |
3305 | unsigned long pfn; | |
3306 | struct page *page; | |
3307 | void *ptr; | |
3308 | ||
3309 | switch (offset) { | |
3310 | case IORING_OFF_SQ_RING: | |
75b28aff HV |
3311 | case IORING_OFF_CQ_RING: |
3312 | ptr = ctx->rings; | |
2b188cc1 JA |
3313 | break; |
3314 | case IORING_OFF_SQES: | |
3315 | ptr = ctx->sq_sqes; | |
3316 | break; | |
2b188cc1 JA |
3317 | default: |
3318 | return -EINVAL; | |
3319 | } | |
3320 | ||
3321 | page = virt_to_head_page(ptr); | |
3322 | if (sz > (PAGE_SIZE << compound_order(page))) | |
3323 | return -EINVAL; | |
3324 | ||
3325 | pfn = virt_to_phys(ptr) >> PAGE_SHIFT; | |
3326 | return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); | |
3327 | } | |
3328 | ||
3329 | SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, | |
3330 | u32, min_complete, u32, flags, const sigset_t __user *, sig, | |
3331 | size_t, sigsz) | |
3332 | { | |
3333 | struct io_ring_ctx *ctx; | |
3334 | long ret = -EBADF; | |
3335 | int submitted = 0; | |
3336 | struct fd f; | |
3337 | ||
6c271ce2 | 3338 | if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP)) |
2b188cc1 JA |
3339 | return -EINVAL; |
3340 | ||
3341 | f = fdget(fd); | |
3342 | if (!f.file) | |
3343 | return -EBADF; | |
3344 | ||
3345 | ret = -EOPNOTSUPP; | |
3346 | if (f.file->f_op != &io_uring_fops) | |
3347 | goto out_fput; | |
3348 | ||
3349 | ret = -ENXIO; | |
3350 | ctx = f.file->private_data; | |
3351 | if (!percpu_ref_tryget(&ctx->refs)) | |
3352 | goto out_fput; | |
3353 | ||
6c271ce2 JA |
3354 | /* |
3355 | * For SQ polling, the thread will do all submissions and completions. | |
3356 | * Just return the requested submit count, and wake the thread if | |
3357 | * we were asked to. | |
3358 | */ | |
b2a9eada | 3359 | ret = 0; |
6c271ce2 JA |
3360 | if (ctx->flags & IORING_SETUP_SQPOLL) { |
3361 | if (flags & IORING_ENTER_SQ_WAKEUP) | |
3362 | wake_up(&ctx->sqo_wait); | |
3363 | submitted = to_submit; | |
b2a9eada | 3364 | } else if (to_submit) { |
c5766668 JA |
3365 | bool block_for_last = false; |
3366 | ||
2b188cc1 JA |
3367 | to_submit = min(to_submit, ctx->sq_entries); |
3368 | ||
c5766668 JA |
3369 | /* |
3370 | * Allow last submission to block in a series, IFF the caller | |
3371 | * asked to wait for events and we don't currently have | |
3372 | * enough. This potentially avoids an async punt. | |
3373 | */ | |
3374 | if (to_submit == min_complete && | |
3375 | io_cqring_events(ctx->rings) < min_complete) | |
3376 | block_for_last = true; | |
3377 | ||
2b188cc1 | 3378 | mutex_lock(&ctx->uring_lock); |
c5766668 | 3379 | submitted = io_ring_submit(ctx, to_submit, block_for_last); |
2b188cc1 | 3380 | mutex_unlock(&ctx->uring_lock); |
2b188cc1 JA |
3381 | } |
3382 | if (flags & IORING_ENTER_GETEVENTS) { | |
def596e9 JA |
3383 | unsigned nr_events = 0; |
3384 | ||
2b188cc1 JA |
3385 | min_complete = min(min_complete, ctx->cq_entries); |
3386 | ||
def596e9 | 3387 | if (ctx->flags & IORING_SETUP_IOPOLL) { |
def596e9 | 3388 | ret = io_iopoll_check(ctx, &nr_events, min_complete); |
def596e9 JA |
3389 | } else { |
3390 | ret = io_cqring_wait(ctx, min_complete, sig, sigsz); | |
3391 | } | |
2b188cc1 JA |
3392 | } |
3393 | ||
2b188cc1 JA |
3394 | io_ring_drop_ctx_refs(ctx, 1); |
3395 | out_fput: | |
3396 | fdput(f); | |
3397 | return submitted ? submitted : ret; | |
3398 | } | |
3399 | ||
3400 | static const struct file_operations io_uring_fops = { | |
3401 | .release = io_uring_release, | |
3402 | .mmap = io_uring_mmap, | |
3403 | .poll = io_uring_poll, | |
3404 | .fasync = io_uring_fasync, | |
3405 | }; | |
3406 | ||
3407 | static int io_allocate_scq_urings(struct io_ring_ctx *ctx, | |
3408 | struct io_uring_params *p) | |
3409 | { | |
75b28aff HV |
3410 | struct io_rings *rings; |
3411 | size_t size, sq_array_offset; | |
2b188cc1 | 3412 | |
75b28aff HV |
3413 | size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset); |
3414 | if (size == SIZE_MAX) | |
3415 | return -EOVERFLOW; | |
3416 | ||
3417 | rings = io_mem_alloc(size); | |
3418 | if (!rings) | |
2b188cc1 JA |
3419 | return -ENOMEM; |
3420 | ||
75b28aff HV |
3421 | ctx->rings = rings; |
3422 | ctx->sq_array = (u32 *)((char *)rings + sq_array_offset); | |
3423 | rings->sq_ring_mask = p->sq_entries - 1; | |
3424 | rings->cq_ring_mask = p->cq_entries - 1; | |
3425 | rings->sq_ring_entries = p->sq_entries; | |
3426 | rings->cq_ring_entries = p->cq_entries; | |
3427 | ctx->sq_mask = rings->sq_ring_mask; | |
3428 | ctx->cq_mask = rings->cq_ring_mask; | |
3429 | ctx->sq_entries = rings->sq_ring_entries; | |
3430 | ctx->cq_entries = rings->cq_ring_entries; | |
2b188cc1 JA |
3431 | |
3432 | size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); | |
3433 | if (size == SIZE_MAX) | |
3434 | return -EOVERFLOW; | |
3435 | ||
3436 | ctx->sq_sqes = io_mem_alloc(size); | |
52e04ef4 | 3437 | if (!ctx->sq_sqes) |
2b188cc1 | 3438 | return -ENOMEM; |
2b188cc1 | 3439 | |
2b188cc1 JA |
3440 | return 0; |
3441 | } | |
3442 | ||
3443 | /* | |
3444 | * Allocate an anonymous fd, this is what constitutes the application | |
3445 | * visible backing of an io_uring instance. The application mmaps this | |
3446 | * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled, | |
3447 | * we have to tie this fd to a socket for file garbage collection purposes. | |
3448 | */ | |
3449 | static int io_uring_get_fd(struct io_ring_ctx *ctx) | |
3450 | { | |
3451 | struct file *file; | |
3452 | int ret; | |
3453 | ||
3454 | #if defined(CONFIG_UNIX) | |
3455 | ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP, | |
3456 | &ctx->ring_sock); | |
3457 | if (ret) | |
3458 | return ret; | |
3459 | #endif | |
3460 | ||
3461 | ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC); | |
3462 | if (ret < 0) | |
3463 | goto err; | |
3464 | ||
3465 | file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx, | |
3466 | O_RDWR | O_CLOEXEC); | |
3467 | if (IS_ERR(file)) { | |
3468 | put_unused_fd(ret); | |
3469 | ret = PTR_ERR(file); | |
3470 | goto err; | |
3471 | } | |
3472 | ||
3473 | #if defined(CONFIG_UNIX) | |
3474 | ctx->ring_sock->file = file; | |
6b06314c | 3475 | ctx->ring_sock->sk->sk_user_data = ctx; |
2b188cc1 JA |
3476 | #endif |
3477 | fd_install(ret, file); | |
3478 | return ret; | |
3479 | err: | |
3480 | #if defined(CONFIG_UNIX) | |
3481 | sock_release(ctx->ring_sock); | |
3482 | ctx->ring_sock = NULL; | |
3483 | #endif | |
3484 | return ret; | |
3485 | } | |
3486 | ||
3487 | static int io_uring_create(unsigned entries, struct io_uring_params *p) | |
3488 | { | |
3489 | struct user_struct *user = NULL; | |
3490 | struct io_ring_ctx *ctx; | |
3491 | bool account_mem; | |
3492 | int ret; | |
3493 | ||
3494 | if (!entries || entries > IORING_MAX_ENTRIES) | |
3495 | return -EINVAL; | |
3496 | ||
3497 | /* | |
3498 | * Use twice as many entries for the CQ ring. It's possible for the | |
3499 | * application to drive a higher depth than the size of the SQ ring, | |
3500 | * since the sqes are only used at submission time. This allows for | |
3501 | * some flexibility in overcommitting a bit. | |
3502 | */ | |
3503 | p->sq_entries = roundup_pow_of_two(entries); | |
3504 | p->cq_entries = 2 * p->sq_entries; | |
3505 | ||
3506 | user = get_uid(current_user()); | |
3507 | account_mem = !capable(CAP_IPC_LOCK); | |
3508 | ||
3509 | if (account_mem) { | |
3510 | ret = io_account_mem(user, | |
3511 | ring_pages(p->sq_entries, p->cq_entries)); | |
3512 | if (ret) { | |
3513 | free_uid(user); | |
3514 | return ret; | |
3515 | } | |
3516 | } | |
3517 | ||
3518 | ctx = io_ring_ctx_alloc(p); | |
3519 | if (!ctx) { | |
3520 | if (account_mem) | |
3521 | io_unaccount_mem(user, ring_pages(p->sq_entries, | |
3522 | p->cq_entries)); | |
3523 | free_uid(user); | |
3524 | return -ENOMEM; | |
3525 | } | |
3526 | ctx->compat = in_compat_syscall(); | |
3527 | ctx->account_mem = account_mem; | |
3528 | ctx->user = user; | |
3529 | ||
3530 | ret = io_allocate_scq_urings(ctx, p); | |
3531 | if (ret) | |
3532 | goto err; | |
3533 | ||
6c271ce2 | 3534 | ret = io_sq_offload_start(ctx, p); |
2b188cc1 JA |
3535 | if (ret) |
3536 | goto err; | |
3537 | ||
3538 | ret = io_uring_get_fd(ctx); | |
3539 | if (ret < 0) | |
3540 | goto err; | |
3541 | ||
3542 | memset(&p->sq_off, 0, sizeof(p->sq_off)); | |
75b28aff HV |
3543 | p->sq_off.head = offsetof(struct io_rings, sq.head); |
3544 | p->sq_off.tail = offsetof(struct io_rings, sq.tail); | |
3545 | p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask); | |
3546 | p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries); | |
3547 | p->sq_off.flags = offsetof(struct io_rings, sq_flags); | |
3548 | p->sq_off.dropped = offsetof(struct io_rings, sq_dropped); | |
3549 | p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings; | |
2b188cc1 JA |
3550 | |
3551 | memset(&p->cq_off, 0, sizeof(p->cq_off)); | |
75b28aff HV |
3552 | p->cq_off.head = offsetof(struct io_rings, cq.head); |
3553 | p->cq_off.tail = offsetof(struct io_rings, cq.tail); | |
3554 | p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask); | |
3555 | p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries); | |
3556 | p->cq_off.overflow = offsetof(struct io_rings, cq_overflow); | |
3557 | p->cq_off.cqes = offsetof(struct io_rings, cqes); | |
ac90f249 JA |
3558 | |
3559 | p->features = IORING_FEAT_SINGLE_MMAP; | |
2b188cc1 JA |
3560 | return ret; |
3561 | err: | |
3562 | io_ring_ctx_wait_and_kill(ctx); | |
3563 | return ret; | |
3564 | } | |
3565 | ||
3566 | /* | |
3567 | * Sets up an aio uring context, and returns the fd. Applications asks for a | |
3568 | * ring size, we return the actual sq/cq ring sizes (among other things) in the | |
3569 | * params structure passed in. | |
3570 | */ | |
3571 | static long io_uring_setup(u32 entries, struct io_uring_params __user *params) | |
3572 | { | |
3573 | struct io_uring_params p; | |
3574 | long ret; | |
3575 | int i; | |
3576 | ||
3577 | if (copy_from_user(&p, params, sizeof(p))) | |
3578 | return -EFAULT; | |
3579 | for (i = 0; i < ARRAY_SIZE(p.resv); i++) { | |
3580 | if (p.resv[i]) | |
3581 | return -EINVAL; | |
3582 | } | |
3583 | ||
6c271ce2 JA |
3584 | if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL | |
3585 | IORING_SETUP_SQ_AFF)) | |
2b188cc1 JA |
3586 | return -EINVAL; |
3587 | ||
3588 | ret = io_uring_create(entries, &p); | |
3589 | if (ret < 0) | |
3590 | return ret; | |
3591 | ||
3592 | if (copy_to_user(params, &p, sizeof(p))) | |
3593 | return -EFAULT; | |
3594 | ||
3595 | return ret; | |
3596 | } | |
3597 | ||
3598 | SYSCALL_DEFINE2(io_uring_setup, u32, entries, | |
3599 | struct io_uring_params __user *, params) | |
3600 | { | |
3601 | return io_uring_setup(entries, params); | |
3602 | } | |
3603 | ||
edafccee JA |
3604 | static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode, |
3605 | void __user *arg, unsigned nr_args) | |
b19062a5 JA |
3606 | __releases(ctx->uring_lock) |
3607 | __acquires(ctx->uring_lock) | |
edafccee JA |
3608 | { |
3609 | int ret; | |
3610 | ||
35fa71a0 JA |
3611 | /* |
3612 | * We're inside the ring mutex, if the ref is already dying, then | |
3613 | * someone else killed the ctx or is already going through | |
3614 | * io_uring_register(). | |
3615 | */ | |
3616 | if (percpu_ref_is_dying(&ctx->refs)) | |
3617 | return -ENXIO; | |
3618 | ||
edafccee | 3619 | percpu_ref_kill(&ctx->refs); |
b19062a5 JA |
3620 | |
3621 | /* | |
3622 | * Drop uring mutex before waiting for references to exit. If another | |
3623 | * thread is currently inside io_uring_enter() it might need to grab | |
3624 | * the uring_lock to make progress. If we hold it here across the drain | |
3625 | * wait, then we can deadlock. It's safe to drop the mutex here, since | |
3626 | * no new references will come in after we've killed the percpu ref. | |
3627 | */ | |
3628 | mutex_unlock(&ctx->uring_lock); | |
edafccee | 3629 | wait_for_completion(&ctx->ctx_done); |
b19062a5 | 3630 | mutex_lock(&ctx->uring_lock); |
edafccee JA |
3631 | |
3632 | switch (opcode) { | |
3633 | case IORING_REGISTER_BUFFERS: | |
3634 | ret = io_sqe_buffer_register(ctx, arg, nr_args); | |
3635 | break; | |
3636 | case IORING_UNREGISTER_BUFFERS: | |
3637 | ret = -EINVAL; | |
3638 | if (arg || nr_args) | |
3639 | break; | |
3640 | ret = io_sqe_buffer_unregister(ctx); | |
3641 | break; | |
6b06314c JA |
3642 | case IORING_REGISTER_FILES: |
3643 | ret = io_sqe_files_register(ctx, arg, nr_args); | |
3644 | break; | |
3645 | case IORING_UNREGISTER_FILES: | |
3646 | ret = -EINVAL; | |
3647 | if (arg || nr_args) | |
3648 | break; | |
3649 | ret = io_sqe_files_unregister(ctx); | |
3650 | break; | |
9b402849 JA |
3651 | case IORING_REGISTER_EVENTFD: |
3652 | ret = -EINVAL; | |
3653 | if (nr_args != 1) | |
3654 | break; | |
3655 | ret = io_eventfd_register(ctx, arg); | |
3656 | break; | |
3657 | case IORING_UNREGISTER_EVENTFD: | |
3658 | ret = -EINVAL; | |
3659 | if (arg || nr_args) | |
3660 | break; | |
3661 | ret = io_eventfd_unregister(ctx); | |
3662 | break; | |
edafccee JA |
3663 | default: |
3664 | ret = -EINVAL; | |
3665 | break; | |
3666 | } | |
3667 | ||
3668 | /* bring the ctx back to life */ | |
3669 | reinit_completion(&ctx->ctx_done); | |
3670 | percpu_ref_reinit(&ctx->refs); | |
3671 | return ret; | |
3672 | } | |
3673 | ||
3674 | SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode, | |
3675 | void __user *, arg, unsigned int, nr_args) | |
3676 | { | |
3677 | struct io_ring_ctx *ctx; | |
3678 | long ret = -EBADF; | |
3679 | struct fd f; | |
3680 | ||
3681 | f = fdget(fd); | |
3682 | if (!f.file) | |
3683 | return -EBADF; | |
3684 | ||
3685 | ret = -EOPNOTSUPP; | |
3686 | if (f.file->f_op != &io_uring_fops) | |
3687 | goto out_fput; | |
3688 | ||
3689 | ctx = f.file->private_data; | |
3690 | ||
3691 | mutex_lock(&ctx->uring_lock); | |
3692 | ret = __io_uring_register(ctx, opcode, arg, nr_args); | |
3693 | mutex_unlock(&ctx->uring_lock); | |
3694 | out_fput: | |
3695 | fdput(f); | |
3696 | return ret; | |
3697 | } | |
3698 | ||
2b188cc1 JA |
3699 | static int __init io_uring_init(void) |
3700 | { | |
3701 | req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC); | |
3702 | return 0; | |
3703 | }; | |
3704 | __initcall(io_uring_init); |