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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 | |
d068b506 | 14 | * through a control-dependency in io_get_cqe (smp_store_release to |
1e84b97b SB |
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> | |
52de1fe1 | 46 | #include <net/compat.h> |
2b188cc1 JA |
47 | #include <linux/refcount.h> |
48 | #include <linux/uio.h> | |
6b47ee6e | 49 | #include <linux/bits.h> |
2b188cc1 JA |
50 | |
51 | #include <linux/sched/signal.h> | |
52 | #include <linux/fs.h> | |
53 | #include <linux/file.h> | |
54 | #include <linux/fdtable.h> | |
55 | #include <linux/mm.h> | |
56 | #include <linux/mman.h> | |
2b188cc1 JA |
57 | #include <linux/percpu.h> |
58 | #include <linux/slab.h> | |
edafccee | 59 | #include <linux/bvec.h> |
2b188cc1 JA |
60 | #include <linux/net.h> |
61 | #include <net/sock.h> | |
62 | #include <net/af_unix.h> | |
63 | #include <linux/anon_inodes.h> | |
64 | #include <linux/sched/mm.h> | |
65 | #include <linux/uaccess.h> | |
66 | #include <linux/nospec.h> | |
aa4c3967 | 67 | #include <linux/highmem.h> |
15b71abe | 68 | #include <linux/fsnotify.h> |
4840e418 | 69 | #include <linux/fadvise.h> |
b41e9852 | 70 | #include <linux/task_work.h> |
0f212204 | 71 | #include <linux/io_uring.h> |
b66509b8 | 72 | #include <linux/io_uring/cmd.h> |
5bd2182d | 73 | #include <linux/audit.h> |
cdc1404a | 74 | #include <linux/security.h> |
d808459b | 75 | #include <asm/shmparam.h> |
2b188cc1 | 76 | |
c826bd7a DD |
77 | #define CREATE_TRACE_POINTS |
78 | #include <trace/events/io_uring.h> | |
79 | ||
2b188cc1 JA |
80 | #include <uapi/linux/io_uring.h> |
81 | ||
561fb04a | 82 | #include "io-wq.h" |
2b188cc1 | 83 | |
de23077e | 84 | #include "io_uring.h" |
329061d3 | 85 | #include "opdef.h" |
e418bbc9 | 86 | #include "refs.h" |
c9f06aa7 | 87 | #include "tctx.h" |
c4320315 | 88 | #include "register.h" |
17437f31 | 89 | #include "sqpoll.h" |
a4ad4f74 | 90 | #include "fdinfo.h" |
3b77495a | 91 | #include "kbuf.h" |
73572984 | 92 | #include "rsrc.h" |
38513c46 | 93 | #include "cancel.h" |
43e0bbbd | 94 | #include "net.h" |
eb42cebb | 95 | #include "notif.h" |
f31ecf67 | 96 | #include "waitid.h" |
194bb58c | 97 | #include "futex.h" |
e27f928e | 98 | |
59915143 | 99 | #include "timeout.h" |
329061d3 | 100 | #include "poll.h" |
c92fcfc2 | 101 | #include "rw.h" |
9b797a37 | 102 | #include "alloc_cache.h" |
5e2a18d9 | 103 | |
5277deaa | 104 | #define IORING_MAX_ENTRIES 32768 |
33a107f0 | 105 | #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES) |
65e19f54 | 106 | |
68fe256a PB |
107 | #define SQE_COMMON_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_LINK | \ |
108 | IOSQE_IO_HARDLINK | IOSQE_ASYNC) | |
109 | ||
5562a8d7 PB |
110 | #define SQE_VALID_FLAGS (SQE_COMMON_FLAGS | IOSQE_BUFFER_SELECT | \ |
111 | IOSQE_IO_DRAIN | IOSQE_CQE_SKIP_SUCCESS) | |
68fe256a | 112 | |
c854357b | 113 | #define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \ |
9cae36a0 JA |
114 | REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS | \ |
115 | REQ_F_ASYNC_DATA) | |
b16fed66 | 116 | |
a538be5b PB |
117 | #define IO_REQ_CLEAN_SLOW_FLAGS (REQ_F_REFCOUNT | REQ_F_LINK | REQ_F_HARDLINK |\ |
118 | IO_REQ_CLEAN_FLAGS) | |
119 | ||
09899b19 PB |
120 | #define IO_TCTX_REFS_CACHE_NR (1U << 10) |
121 | ||
6dd0be1e | 122 | #define IO_COMPL_BATCH 32 |
bf019da7 | 123 | #define IO_REQ_ALLOC_BATCH 8 |
258b29a9 | 124 | |
10988a0a DY |
125 | enum { |
126 | IO_CHECK_CQ_OVERFLOW_BIT, | |
155bc950 | 127 | IO_CHECK_CQ_DROPPED_BIT, |
10988a0a DY |
128 | }; |
129 | ||
27dc8338 PB |
130 | struct io_defer_entry { |
131 | struct list_head list; | |
132 | struct io_kiocb *req; | |
9cf7c104 | 133 | u32 seq; |
2b188cc1 JA |
134 | }; |
135 | ||
0756a869 PB |
136 | /* requests with any of those set should undergo io_disarm_next() */ |
137 | #define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL) | |
da1a08c5 | 138 | #define IO_REQ_LINK_FLAGS (REQ_F_LINK | REQ_F_HARDLINK) |
0756a869 | 139 | |
b4bc35cf PB |
140 | /* |
141 | * No waiters. It's larger than any valid value of the tw counter | |
142 | * so that tests against ->cq_wait_nr would fail and skip wake_up(). | |
143 | */ | |
144 | #define IO_CQ_WAKE_INIT (-1U) | |
145 | /* Forced wake up if there is a waiter regardless of ->cq_wait_nr */ | |
146 | #define IO_CQ_WAKE_FORCE (IO_CQ_WAKE_INIT >> 1) | |
147 | ||
affa87db | 148 | static bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, |
9936c7c2 | 149 | struct task_struct *task, |
3dd0c97a | 150 | bool cancel_all); |
1ffc5422 | 151 | |
cbc2e203 | 152 | static void io_queue_sqe(struct io_kiocb *req); |
de0617e4 | 153 | |
c1755c25 | 154 | struct kmem_cache *req_cachep; |
2b188cc1 | 155 | |
76d3ccec MR |
156 | static int __read_mostly sysctl_io_uring_disabled; |
157 | static int __read_mostly sysctl_io_uring_group = -1; | |
158 | ||
159 | #ifdef CONFIG_SYSCTL | |
160 | static struct ctl_table kernel_io_uring_disabled_table[] = { | |
161 | { | |
162 | .procname = "io_uring_disabled", | |
163 | .data = &sysctl_io_uring_disabled, | |
164 | .maxlen = sizeof(sysctl_io_uring_disabled), | |
165 | .mode = 0644, | |
166 | .proc_handler = proc_dointvec_minmax, | |
167 | .extra1 = SYSCTL_ZERO, | |
168 | .extra2 = SYSCTL_TWO, | |
169 | }, | |
170 | { | |
171 | .procname = "io_uring_group", | |
172 | .data = &sysctl_io_uring_group, | |
173 | .maxlen = sizeof(gid_t), | |
174 | .mode = 0644, | |
175 | .proc_handler = proc_dointvec, | |
176 | }, | |
177 | {}, | |
178 | }; | |
179 | #endif | |
180 | ||
c450178d PB |
181 | static inline void io_submit_flush_completions(struct io_ring_ctx *ctx) |
182 | { | |
931147dd DY |
183 | if (!wq_list_empty(&ctx->submit_state.compl_reqs) || |
184 | ctx->submit_state.cqes_count) | |
c450178d PB |
185 | __io_submit_flush_completions(ctx); |
186 | } | |
187 | ||
faf88dde PB |
188 | static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx) |
189 | { | |
190 | return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head); | |
191 | } | |
192 | ||
0fc8c2ac DY |
193 | static inline unsigned int __io_cqring_events_user(struct io_ring_ctx *ctx) |
194 | { | |
195 | return READ_ONCE(ctx->rings->cq.tail) - READ_ONCE(ctx->rings->cq.head); | |
196 | } | |
197 | ||
9cae36a0 JA |
198 | static bool io_match_linked(struct io_kiocb *head) |
199 | { | |
200 | struct io_kiocb *req; | |
201 | ||
202 | io_for_each_link(req, head) { | |
203 | if (req->flags & REQ_F_INFLIGHT) | |
204 | return true; | |
205 | } | |
206 | return false; | |
6af3f48b PB |
207 | } |
208 | ||
209 | /* | |
210 | * As io_match_task() but protected against racing with linked timeouts. | |
211 | * User must not hold timeout_lock. | |
212 | */ | |
329061d3 JA |
213 | bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task, |
214 | bool cancel_all) | |
6af3f48b | 215 | { |
9cae36a0 JA |
216 | bool matched; |
217 | ||
6af3f48b PB |
218 | if (task && head->task != task) |
219 | return false; | |
9cae36a0 JA |
220 | if (cancel_all) |
221 | return true; | |
222 | ||
223 | if (head->flags & REQ_F_LINK_TIMEOUT) { | |
224 | struct io_ring_ctx *ctx = head->ctx; | |
225 | ||
226 | /* protect against races with linked timeouts */ | |
227 | spin_lock_irq(&ctx->timeout_lock); | |
228 | matched = io_match_linked(head); | |
229 | spin_unlock_irq(&ctx->timeout_lock); | |
230 | } else { | |
231 | matched = io_match_linked(head); | |
232 | } | |
233 | return matched; | |
6af3f48b PB |
234 | } |
235 | ||
a8295b98 HX |
236 | static inline void req_fail_link_node(struct io_kiocb *req, int res) |
237 | { | |
238 | req_set_fail(req); | |
97b388d7 | 239 | io_req_set_res(req, res, 0); |
a8295b98 HX |
240 | } |
241 | ||
fa05457a PB |
242 | static inline void io_req_add_to_cache(struct io_kiocb *req, struct io_ring_ctx *ctx) |
243 | { | |
244 | wq_stack_add_head(&req->comp_list, &ctx->submit_state.free_list); | |
a8295b98 HX |
245 | } |
246 | ||
c072481d | 247 | static __cold void io_ring_ctx_ref_free(struct percpu_ref *ref) |
2b188cc1 JA |
248 | { |
249 | struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs); | |
250 | ||
0f158b4c | 251 | complete(&ctx->ref_comp); |
2b188cc1 JA |
252 | } |
253 | ||
c072481d | 254 | static __cold void io_fallback_req_func(struct work_struct *work) |
f56165e6 PB |
255 | { |
256 | struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, | |
257 | fallback_work.work); | |
258 | struct llist_node *node = llist_del_all(&ctx->fallback_llist); | |
259 | struct io_kiocb *req, *tmp; | |
a282967c | 260 | struct io_tw_state ts = { .locked = true, }; |
f56165e6 | 261 | |
f7b32e78 | 262 | percpu_ref_get(&ctx->refs); |
31f084b7 | 263 | mutex_lock(&ctx->uring_lock); |
3218e5d3 | 264 | llist_for_each_entry_safe(req, tmp, node, io_task_work.node) |
a282967c PB |
265 | req->io_task_work.func(req, &ts); |
266 | if (WARN_ON_ONCE(!ts.locked)) | |
31f084b7 PB |
267 | return; |
268 | io_submit_flush_completions(ctx); | |
269 | mutex_unlock(&ctx->uring_lock); | |
f7b32e78 | 270 | percpu_ref_put(&ctx->refs); |
f56165e6 PB |
271 | } |
272 | ||
e6f89be6 PB |
273 | static int io_alloc_hash_table(struct io_hash_table *table, unsigned bits) |
274 | { | |
275 | unsigned hash_buckets = 1U << bits; | |
276 | size_t hash_size = hash_buckets * sizeof(table->hbs[0]); | |
277 | ||
278 | table->hbs = kmalloc(hash_size, GFP_KERNEL); | |
279 | if (!table->hbs) | |
280 | return -ENOMEM; | |
281 | ||
282 | table->hash_bits = bits; | |
283 | init_hash_table(table, hash_buckets); | |
284 | return 0; | |
285 | } | |
286 | ||
c072481d | 287 | static __cold struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) |
2b188cc1 JA |
288 | { |
289 | struct io_ring_ctx *ctx; | |
9cfc7e94 | 290 | int hash_bits; |
2b188cc1 JA |
291 | |
292 | ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); | |
293 | if (!ctx) | |
294 | return NULL; | |
295 | ||
9cfc7e94 JA |
296 | xa_init(&ctx->io_bl_xa); |
297 | ||
78076bb6 JA |
298 | /* |
299 | * Use 5 bits less than the max cq entries, that should give us around | |
4a07723f PB |
300 | * 32 entries per hash list if totally full and uniformly spread, but |
301 | * don't keep too many buckets to not overconsume memory. | |
78076bb6 | 302 | */ |
4a07723f PB |
303 | hash_bits = ilog2(p->cq_entries) - 5; |
304 | hash_bits = clamp(hash_bits, 1, 8); | |
e6f89be6 | 305 | if (io_alloc_hash_table(&ctx->cancel_table, hash_bits)) |
78076bb6 | 306 | goto err; |
9ca9fb24 PB |
307 | if (io_alloc_hash_table(&ctx->cancel_table_locked, hash_bits)) |
308 | goto err; | |
21482896 | 309 | if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free, |
48904229 | 310 | 0, GFP_KERNEL)) |
206aefde | 311 | goto err; |
2b188cc1 JA |
312 | |
313 | ctx->flags = p->flags; | |
b4bc35cf | 314 | atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT); |
90554200 | 315 | init_waitqueue_head(&ctx->sqo_sq_wait); |
69fb2131 | 316 | INIT_LIST_HEAD(&ctx->sqd_list); |
1d7bb1d5 | 317 | INIT_LIST_HEAD(&ctx->cq_overflow_list); |
cc3cec83 | 318 | INIT_LIST_HEAD(&ctx->io_buffers_cache); |
c392cbec | 319 | INIT_HLIST_HEAD(&ctx->io_buf_list); |
69bbc6ad PB |
320 | io_alloc_cache_init(&ctx->rsrc_node_cache, IO_NODE_ALLOC_CACHE_MAX, |
321 | sizeof(struct io_rsrc_node)); | |
322 | io_alloc_cache_init(&ctx->apoll_cache, IO_ALLOC_CACHE_MAX, | |
323 | sizeof(struct async_poll)); | |
324 | io_alloc_cache_init(&ctx->netmsg_cache, IO_ALLOC_CACHE_MAX, | |
325 | sizeof(struct io_async_msghdr)); | |
194bb58c | 326 | io_futex_cache_init(ctx); |
0f158b4c | 327 | init_completion(&ctx->ref_comp); |
61cf9370 | 328 | xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1); |
2b188cc1 | 329 | mutex_init(&ctx->uring_lock); |
311997b3 | 330 | init_waitqueue_head(&ctx->cq_wait); |
7b235dd8 | 331 | init_waitqueue_head(&ctx->poll_wq); |
4ea15b56 | 332 | init_waitqueue_head(&ctx->rsrc_quiesce_wq); |
2b188cc1 | 333 | spin_lock_init(&ctx->completion_lock); |
89850fce | 334 | spin_lock_init(&ctx->timeout_lock); |
5eef4e87 | 335 | INIT_WQ_LIST(&ctx->iopoll_list); |
cc3cec83 | 336 | INIT_LIST_HEAD(&ctx->io_buffers_comp); |
de0617e4 | 337 | INIT_LIST_HEAD(&ctx->defer_list); |
5262f567 | 338 | INIT_LIST_HEAD(&ctx->timeout_list); |
ef9dd637 | 339 | INIT_LIST_HEAD(&ctx->ltimeout_list); |
d67d2263 | 340 | INIT_LIST_HEAD(&ctx->rsrc_ref_list); |
c0e0d6ba | 341 | init_llist_head(&ctx->work_llist); |
13bf43f5 | 342 | INIT_LIST_HEAD(&ctx->tctx_list); |
c2b6c6bc PB |
343 | ctx->submit_state.free_list.next = NULL; |
344 | INIT_WQ_LIST(&ctx->locked_free_list); | |
f31ecf67 | 345 | INIT_HLIST_HEAD(&ctx->waitid_list); |
194bb58c JA |
346 | #ifdef CONFIG_FUTEX |
347 | INIT_HLIST_HEAD(&ctx->futex_list); | |
348 | #endif | |
9011bf9a | 349 | INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func); |
6f33b0bc | 350 | INIT_WQ_LIST(&ctx->submit_state.compl_reqs); |
93b8cc60 | 351 | INIT_HLIST_HEAD(&ctx->cancelable_uring_cmd); |
2b188cc1 | 352 | return ctx; |
206aefde | 353 | err: |
e6f89be6 | 354 | kfree(ctx->cancel_table.hbs); |
9ca9fb24 | 355 | kfree(ctx->cancel_table_locked.hbs); |
9cfc7e94 JA |
356 | kfree(ctx->io_bl); |
357 | xa_destroy(&ctx->io_bl_xa); | |
206aefde JA |
358 | kfree(ctx); |
359 | return NULL; | |
2b188cc1 JA |
360 | } |
361 | ||
8f6ed49a PB |
362 | static void io_account_cq_overflow(struct io_ring_ctx *ctx) |
363 | { | |
364 | struct io_rings *r = ctx->rings; | |
365 | ||
366 | WRITE_ONCE(r->cq_overflow, READ_ONCE(r->cq_overflow) + 1); | |
367 | ctx->cq_extra--; | |
368 | } | |
369 | ||
9cf7c104 | 370 | static bool req_need_defer(struct io_kiocb *req, u32 seq) |
7adf4eaf | 371 | { |
2bc9930e JA |
372 | if (unlikely(req->flags & REQ_F_IO_DRAIN)) { |
373 | struct io_ring_ctx *ctx = req->ctx; | |
a197f664 | 374 | |
8f6ed49a | 375 | return seq + READ_ONCE(ctx->cq_extra) != ctx->cached_cq_tail; |
2bc9930e | 376 | } |
de0617e4 | 377 | |
9d858b21 | 378 | return false; |
de0617e4 JA |
379 | } |
380 | ||
5a754dea PB |
381 | static void io_clean_op(struct io_kiocb *req) |
382 | { | |
383 | if (req->flags & REQ_F_BUFFER_SELECTED) { | |
384 | spin_lock(&req->ctx->completion_lock); | |
385 | io_put_kbuf_comp(req); | |
386 | spin_unlock(&req->ctx->completion_lock); | |
387 | } | |
388 | ||
389 | if (req->flags & REQ_F_NEED_CLEANUP) { | |
390 | const struct io_cold_def *def = &io_cold_defs[req->opcode]; | |
391 | ||
392 | if (def->cleanup) | |
393 | def->cleanup(req); | |
394 | } | |
395 | if ((req->flags & REQ_F_POLLED) && req->apoll) { | |
396 | kfree(req->apoll->double_poll); | |
397 | kfree(req->apoll); | |
398 | req->apoll = NULL; | |
399 | } | |
400 | if (req->flags & REQ_F_INFLIGHT) { | |
401 | struct io_uring_task *tctx = req->task->io_uring; | |
402 | ||
403 | atomic_dec(&tctx->inflight_tracked); | |
404 | } | |
405 | if (req->flags & REQ_F_CREDS) | |
406 | put_cred(req->creds); | |
407 | if (req->flags & REQ_F_ASYNC_DATA) { | |
408 | kfree(req->async_data); | |
409 | req->async_data = NULL; | |
410 | } | |
411 | req->flags &= ~IO_REQ_CLEAN_FLAGS; | |
412 | } | |
413 | ||
9cae36a0 JA |
414 | static inline void io_req_track_inflight(struct io_kiocb *req) |
415 | { | |
416 | if (!(req->flags & REQ_F_INFLIGHT)) { | |
417 | req->flags |= REQ_F_INFLIGHT; | |
386e4fb6 | 418 | atomic_inc(&req->task->io_uring->inflight_tracked); |
9cae36a0 JA |
419 | } |
420 | } | |
421 | ||
fd08e530 PB |
422 | static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req) |
423 | { | |
906c6caa PB |
424 | if (WARN_ON_ONCE(!req->link)) |
425 | return NULL; | |
426 | ||
4d13d1a4 PB |
427 | req->flags &= ~REQ_F_ARM_LTIMEOUT; |
428 | req->flags |= REQ_F_LINK_TIMEOUT; | |
fd08e530 PB |
429 | |
430 | /* linked timeouts should have two refs once prep'ed */ | |
48dcd38d | 431 | io_req_set_refcount(req); |
4d13d1a4 PB |
432 | __io_req_set_refcount(req->link, 2); |
433 | return req->link; | |
fd08e530 PB |
434 | } |
435 | ||
436 | static inline struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) | |
437 | { | |
4d13d1a4 | 438 | if (likely(!(req->flags & REQ_F_ARM_LTIMEOUT))) |
fd08e530 PB |
439 | return NULL; |
440 | return __io_prep_linked_timeout(req); | |
441 | } | |
442 | ||
cb2d344c PB |
443 | static noinline void __io_arm_ltimeout(struct io_kiocb *req) |
444 | { | |
445 | io_queue_linked_timeout(__io_prep_linked_timeout(req)); | |
446 | } | |
447 | ||
448 | static inline void io_arm_ltimeout(struct io_kiocb *req) | |
449 | { | |
450 | if (unlikely(req->flags & REQ_F_ARM_LTIMEOUT)) | |
451 | __io_arm_ltimeout(req); | |
452 | } | |
453 | ||
1e6fa521 JA |
454 | static void io_prep_async_work(struct io_kiocb *req) |
455 | { | |
a7dd2782 | 456 | const struct io_issue_def *def = &io_issue_defs[req->opcode]; |
1e6fa521 JA |
457 | struct io_ring_ctx *ctx = req->ctx; |
458 | ||
b8e64b53 PB |
459 | if (!(req->flags & REQ_F_CREDS)) { |
460 | req->flags |= REQ_F_CREDS; | |
c10d1f98 | 461 | req->creds = get_current_cred(); |
b8e64b53 | 462 | } |
003e8dcc | 463 | |
e1d675df PB |
464 | req->work.list.next = NULL; |
465 | req->work.flags = 0; | |
8e29da69 | 466 | req->work.cancel_seq = atomic_read(&ctx->cancel_seq); |
feaadc4f PB |
467 | if (req->flags & REQ_F_FORCE_ASYNC) |
468 | req->work.flags |= IO_WQ_WORK_CONCURRENT; | |
469 | ||
3beed235 | 470 | if (req->file && !(req->flags & REQ_F_FIXED_FILE)) |
8487f083 | 471 | req->flags |= io_file_get_flags(req->file); |
f6b543fd | 472 | |
8b1df11f | 473 | if (req->file && (req->flags & REQ_F_ISREG)) { |
d4755e15 JA |
474 | bool should_hash = def->hash_reg_file; |
475 | ||
476 | /* don't serialize this request if the fs doesn't need it */ | |
477 | if (should_hash && (req->file->f_flags & O_DIRECT) && | |
478 | (req->file->f_mode & FMODE_DIO_PARALLEL_WRITE)) | |
479 | should_hash = false; | |
480 | if (should_hash || (ctx->flags & IORING_SETUP_IOPOLL)) | |
1e6fa521 | 481 | io_wq_hash_work(&req->work, file_inode(req->file)); |
4b982bd0 | 482 | } else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) { |
1e6fa521 JA |
483 | if (def->unbound_nonreg_file) |
484 | req->work.flags |= IO_WQ_WORK_UNBOUND; | |
485 | } | |
561fb04a | 486 | } |
cccf0ee8 | 487 | |
cbdcb435 | 488 | static void io_prep_async_link(struct io_kiocb *req) |
561fb04a | 489 | { |
cbdcb435 | 490 | struct io_kiocb *cur; |
54a91f3b | 491 | |
44eff40a PB |
492 | if (req->flags & REQ_F_LINK_TIMEOUT) { |
493 | struct io_ring_ctx *ctx = req->ctx; | |
494 | ||
674ee8e1 | 495 | spin_lock_irq(&ctx->timeout_lock); |
44eff40a PB |
496 | io_for_each_link(cur, req) |
497 | io_prep_async_work(cur); | |
674ee8e1 | 498 | spin_unlock_irq(&ctx->timeout_lock); |
44eff40a PB |
499 | } else { |
500 | io_for_each_link(cur, req) | |
501 | io_prep_async_work(cur); | |
502 | } | |
561fb04a JA |
503 | } |
504 | ||
a282967c | 505 | void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use) |
561fb04a | 506 | { |
cbdcb435 | 507 | struct io_kiocb *link = io_prep_linked_timeout(req); |
5aa75ed5 | 508 | struct io_uring_task *tctx = req->task->io_uring; |
561fb04a | 509 | |
3bfe6106 JA |
510 | BUG_ON(!tctx); |
511 | BUG_ON(!tctx->io_wq); | |
561fb04a | 512 | |
cbdcb435 PB |
513 | /* init ->work of the whole link before punting */ |
514 | io_prep_async_link(req); | |
991468dc JA |
515 | |
516 | /* | |
517 | * Not expected to happen, but if we do have a bug where this _can_ | |
518 | * happen, catch it here and ensure the request is marked as | |
519 | * canceled. That will make io-wq go through the usual work cancel | |
520 | * procedure rather than attempt to run this request (or create a new | |
521 | * worker for it). | |
522 | */ | |
523 | if (WARN_ON_ONCE(!same_thread_group(req->task, current))) | |
524 | req->work.flags |= IO_WQ_WORK_CANCEL; | |
525 | ||
48863ffd | 526 | trace_io_uring_queue_async_work(req, io_wq_is_hashed(&req->work)); |
ebf93667 | 527 | io_wq_enqueue(tctx->io_wq, &req->work); |
7271ef3a JA |
528 | if (link) |
529 | io_queue_linked_timeout(link); | |
cbdcb435 PB |
530 | } |
531 | ||
c072481d | 532 | static __cold void io_queue_deferred(struct io_ring_ctx *ctx) |
de0617e4 | 533 | { |
441b8a78 | 534 | while (!list_empty(&ctx->defer_list)) { |
27dc8338 PB |
535 | struct io_defer_entry *de = list_first_entry(&ctx->defer_list, |
536 | struct io_defer_entry, list); | |
de0617e4 | 537 | |
9cf7c104 | 538 | if (req_need_defer(de->req, de->seq)) |
04518945 | 539 | break; |
27dc8338 | 540 | list_del_init(&de->list); |
907d1df3 | 541 | io_req_task_queue(de->req); |
27dc8338 | 542 | kfree(de); |
441b8a78 | 543 | } |
04518945 PB |
544 | } |
545 | ||
c4320315 | 546 | void io_eventfd_ops(struct rcu_head *rcu) |
f2842ab5 | 547 | { |
d8e9214f | 548 | struct io_ev_fd *ev_fd = container_of(rcu, struct io_ev_fd, rcu); |
21a091b9 | 549 | int ops = atomic_xchg(&ev_fd->ops, 0); |
305bef98 | 550 | |
21a091b9 | 551 | if (ops & BIT(IO_EVENTFD_OP_SIGNAL_BIT)) |
120ae585 | 552 | eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE); |
d8e9214f | 553 | |
21a091b9 DY |
554 | /* IO_EVENTFD_OP_FREE_BIT may not be set here depending on callback |
555 | * ordering in a race but if references are 0 we know we have to free | |
556 | * it regardless. | |
305bef98 | 557 | */ |
21a091b9 DY |
558 | if (atomic_dec_and_test(&ev_fd->refs)) { |
559 | eventfd_ctx_put(ev_fd->cq_ev_fd); | |
560 | kfree(ev_fd); | |
561 | } | |
d8e9214f DY |
562 | } |
563 | ||
77bc59b4 | 564 | static void io_eventfd_signal(struct io_ring_ctx *ctx) |
f2842ab5 | 565 | { |
21a091b9 | 566 | struct io_ev_fd *ev_fd = NULL; |
77bc59b4 | 567 | |
77bc59b4 UA |
568 | rcu_read_lock(); |
569 | /* | |
570 | * rcu_dereference ctx->io_ev_fd once and use it for both for checking | |
571 | * and eventfd_signal | |
572 | */ | |
573 | ev_fd = rcu_dereference(ctx->io_ev_fd); | |
574 | ||
575 | /* | |
576 | * Check again if ev_fd exists incase an io_eventfd_unregister call | |
577 | * completed between the NULL check of ctx->io_ev_fd at the start of | |
578 | * the function and rcu_read_lock. | |
579 | */ | |
580 | if (unlikely(!ev_fd)) | |
581 | goto out; | |
7e55a19c | 582 | if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED) |
77bc59b4 | 583 | goto out; |
21a091b9 DY |
584 | if (ev_fd->eventfd_async && !io_wq_current_is_worker()) |
585 | goto out; | |
77bc59b4 | 586 | |
21a091b9 | 587 | if (likely(eventfd_signal_allowed())) { |
120ae585 | 588 | eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE); |
21a091b9 DY |
589 | } else { |
590 | atomic_inc(&ev_fd->refs); | |
591 | if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops)) | |
44a84da4 | 592 | call_rcu_hurry(&ev_fd->rcu, io_eventfd_ops); |
21a091b9 DY |
593 | else |
594 | atomic_dec(&ev_fd->refs); | |
595 | } | |
596 | ||
77bc59b4 UA |
597 | out: |
598 | rcu_read_unlock(); | |
f2842ab5 JA |
599 | } |
600 | ||
21a091b9 DY |
601 | static void io_eventfd_flush_signal(struct io_ring_ctx *ctx) |
602 | { | |
603 | bool skip; | |
604 | ||
605 | spin_lock(&ctx->completion_lock); | |
606 | ||
607 | /* | |
608 | * Eventfd should only get triggered when at least one event has been | |
609 | * posted. Some applications rely on the eventfd notification count | |
610 | * only changing IFF a new CQE has been added to the CQ ring. There's | |
611 | * no depedency on 1:1 relationship between how many times this | |
612 | * function is called (and hence the eventfd count) and number of CQEs | |
613 | * posted to the CQ ring. | |
614 | */ | |
615 | skip = ctx->cached_cq_tail == ctx->evfd_last_cq_tail; | |
616 | ctx->evfd_last_cq_tail = ctx->cached_cq_tail; | |
617 | spin_unlock(&ctx->completion_lock); | |
618 | if (skip) | |
619 | return; | |
620 | ||
621 | io_eventfd_signal(ctx); | |
622 | } | |
623 | ||
a830ffd2 PB |
624 | void __io_commit_cqring_flush(struct io_ring_ctx *ctx) |
625 | { | |
bca39f39 PB |
626 | if (ctx->poll_activated) |
627 | io_poll_wq_wake(ctx); | |
e5f30f6f PB |
628 | if (ctx->off_timeout_used) |
629 | io_flush_timeouts(ctx); | |
630 | if (ctx->drain_active) { | |
a830ffd2 | 631 | spin_lock(&ctx->completion_lock); |
e5f30f6f | 632 | io_queue_deferred(ctx); |
a830ffd2 PB |
633 | spin_unlock(&ctx->completion_lock); |
634 | } | |
635 | if (ctx->has_evfd) | |
21a091b9 | 636 | io_eventfd_flush_signal(ctx); |
a830ffd2 PB |
637 | } |
638 | ||
f66f7342 | 639 | static inline void __io_cq_lock(struct io_ring_ctx *ctx) |
f66f7342 | 640 | { |
ec26c225 | 641 | if (!ctx->lockless_cq) |
f66f7342 PB |
642 | spin_lock(&ctx->completion_lock); |
643 | } | |
644 | ||
6971253f PB |
645 | static inline void io_cq_lock(struct io_ring_ctx *ctx) |
646 | __acquires(ctx->completion_lock) | |
647 | { | |
648 | spin_lock(&ctx->completion_lock); | |
649 | } | |
650 | ||
f66f7342 | 651 | static inline void __io_cq_unlock_post(struct io_ring_ctx *ctx) |
3181e22f PB |
652 | { |
653 | io_commit_cqring(ctx); | |
54927baf | 654 | if (!ctx->task_complete) { |
ec26c225 PB |
655 | if (!ctx->lockless_cq) |
656 | spin_unlock(&ctx->completion_lock); | |
657 | /* IOPOLL rings only need to wake up if it's also SQPOLL */ | |
658 | if (!ctx->syscall_iopoll) | |
659 | io_cqring_wake(ctx); | |
3181e22f | 660 | } |
54927baf | 661 | io_commit_cqring_flush(ctx); |
3181e22f PB |
662 | } |
663 | ||
0fdb9a19 | 664 | static void io_cq_unlock_post(struct io_ring_ctx *ctx) |
5d772916 | 665 | __releases(ctx->completion_lock) |
25399321 | 666 | { |
f66f7342 PB |
667 | io_commit_cqring(ctx); |
668 | spin_unlock(&ctx->completion_lock); | |
f66f7342 | 669 | io_cqring_wake(ctx); |
54927baf | 670 | io_commit_cqring_flush(ctx); |
25399321 PB |
671 | } |
672 | ||
c4a2ed72 | 673 | /* Returns true if there are no backlogged entries after the flush */ |
a85381d8 PB |
674 | static void io_cqring_overflow_kill(struct io_ring_ctx *ctx) |
675 | { | |
676 | struct io_overflow_cqe *ocqe; | |
677 | LIST_HEAD(list); | |
678 | ||
f432b76b | 679 | spin_lock(&ctx->completion_lock); |
a85381d8 PB |
680 | list_splice_init(&ctx->cq_overflow_list, &list); |
681 | clear_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq); | |
f432b76b | 682 | spin_unlock(&ctx->completion_lock); |
a85381d8 PB |
683 | |
684 | while (!list_empty(&list)) { | |
685 | ocqe = list_first_entry(&list, struct io_overflow_cqe, list); | |
686 | list_del(&ocqe->list); | |
687 | kfree(ocqe); | |
688 | } | |
689 | } | |
690 | ||
1b346e4a | 691 | static void __io_cqring_overflow_flush(struct io_ring_ctx *ctx) |
1d7bb1d5 | 692 | { |
e45a3e05 | 693 | size_t cqe_size = sizeof(struct io_uring_cqe); |
1d7bb1d5 | 694 | |
a85381d8 | 695 | if (__io_cqring_events(ctx) == ctx->cq_entries) |
1b346e4a | 696 | return; |
1d7bb1d5 | 697 | |
e45a3e05 SR |
698 | if (ctx->flags & IORING_SETUP_CQE32) |
699 | cqe_size <<= 1; | |
700 | ||
25399321 | 701 | io_cq_lock(ctx); |
6c2450ae | 702 | while (!list_empty(&ctx->cq_overflow_list)) { |
59fbc409 | 703 | struct io_uring_cqe *cqe; |
6c2450ae | 704 | struct io_overflow_cqe *ocqe; |
e6c8aa9a | 705 | |
59fbc409 | 706 | if (!io_get_cqe_overflow(ctx, &cqe, true)) |
1d7bb1d5 | 707 | break; |
6c2450ae PB |
708 | ocqe = list_first_entry(&ctx->cq_overflow_list, |
709 | struct io_overflow_cqe, list); | |
a85381d8 | 710 | memcpy(cqe, &ocqe->cqe, cqe_size); |
6c2450ae PB |
711 | list_del(&ocqe->list); |
712 | kfree(ocqe); | |
1d7bb1d5 JA |
713 | } |
714 | ||
1b346e4a | 715 | if (list_empty(&ctx->cq_overflow_list)) { |
10988a0a | 716 | clear_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq); |
3a4b89a2 | 717 | atomic_andnot(IORING_SQ_CQ_OVERFLOW, &ctx->rings->sq_flags); |
09e88404 | 718 | } |
25399321 | 719 | io_cq_unlock_post(ctx); |
1d7bb1d5 JA |
720 | } |
721 | ||
52ea806a JA |
722 | static void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx) |
723 | { | |
724 | /* iopoll syncs against uring_lock, not completion_lock */ | |
725 | if (ctx->flags & IORING_SETUP_IOPOLL) | |
726 | mutex_lock(&ctx->uring_lock); | |
727 | __io_cqring_overflow_flush(ctx); | |
728 | if (ctx->flags & IORING_SETUP_IOPOLL) | |
729 | mutex_unlock(&ctx->uring_lock); | |
730 | } | |
731 | ||
1b346e4a | 732 | static void io_cqring_overflow_flush(struct io_ring_ctx *ctx) |
6c503150 | 733 | { |
52ea806a JA |
734 | if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)) |
735 | io_cqring_do_overflow_flush(ctx); | |
6c503150 PB |
736 | } |
737 | ||
5afa4650 | 738 | /* can be called by any task */ |
2fdd6fb5 | 739 | static void io_put_task_remote(struct task_struct *task) |
6a290a14 PB |
740 | { |
741 | struct io_uring_task *tctx = task->io_uring; | |
742 | ||
2fdd6fb5 | 743 | percpu_counter_sub(&tctx->inflight, 1); |
8d664282 | 744 | if (unlikely(atomic_read(&tctx->in_cancel))) |
9d170164 | 745 | wake_up(&tctx->wait); |
2fdd6fb5 | 746 | put_task_struct(task); |
9d170164 PB |
747 | } |
748 | ||
5afa4650 | 749 | /* used by a task to put its own references */ |
2fdd6fb5 | 750 | static void io_put_task_local(struct task_struct *task) |
5afa4650 | 751 | { |
2fdd6fb5 | 752 | task->io_uring->cached_refs++; |
5afa4650 PB |
753 | } |
754 | ||
89800a2d | 755 | /* must to be called somewhat shortly after putting a request */ |
2fdd6fb5 | 756 | static inline void io_put_task(struct task_struct *task) |
89800a2d PB |
757 | { |
758 | if (likely(task == current)) | |
2fdd6fb5 | 759 | io_put_task_local(task); |
89800a2d | 760 | else |
2fdd6fb5 | 761 | io_put_task_remote(task); |
89800a2d PB |
762 | } |
763 | ||
63809137 | 764 | void io_task_refs_refill(struct io_uring_task *tctx) |
9a10867a PB |
765 | { |
766 | unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR; | |
767 | ||
768 | percpu_counter_add(&tctx->inflight, refill); | |
769 | refcount_add(refill, ¤t->usage); | |
770 | tctx->cached_refs += refill; | |
771 | } | |
772 | ||
3cc7fdb9 PB |
773 | static __cold void io_uring_drop_tctx_refs(struct task_struct *task) |
774 | { | |
775 | struct io_uring_task *tctx = task->io_uring; | |
776 | unsigned int refs = tctx->cached_refs; | |
777 | ||
778 | if (refs) { | |
779 | tctx->cached_refs = 0; | |
780 | percpu_counter_sub(&tctx->inflight, refs); | |
781 | put_task_struct_many(task, refs); | |
782 | } | |
783 | } | |
784 | ||
68494a65 PB |
785 | static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data, |
786 | s32 res, u32 cflags, u64 extra1, u64 extra2) | |
2b188cc1 | 787 | { |
cce4b8b0 | 788 | struct io_overflow_cqe *ocqe; |
e45a3e05 SR |
789 | size_t ocq_size = sizeof(struct io_overflow_cqe); |
790 | bool is_cqe32 = (ctx->flags & IORING_SETUP_CQE32); | |
2b188cc1 | 791 | |
f26cc959 PB |
792 | lockdep_assert_held(&ctx->completion_lock); |
793 | ||
e45a3e05 SR |
794 | if (is_cqe32) |
795 | ocq_size += sizeof(struct io_uring_cqe); | |
2b188cc1 | 796 | |
e45a3e05 | 797 | ocqe = kmalloc(ocq_size, GFP_ATOMIC | __GFP_ACCOUNT); |
08dcd028 | 798 | trace_io_uring_cqe_overflow(ctx, user_data, res, cflags, ocqe); |
cce4b8b0 PB |
799 | if (!ocqe) { |
800 | /* | |
801 | * If we're in ring overflow flush mode, or in task cancel mode, | |
802 | * or cannot allocate an overflow entry, then we need to drop it | |
803 | * on the floor. | |
804 | */ | |
8f6ed49a | 805 | io_account_cq_overflow(ctx); |
155bc950 | 806 | set_bit(IO_CHECK_CQ_DROPPED_BIT, &ctx->check_cq); |
cce4b8b0 | 807 | return false; |
2b188cc1 | 808 | } |
cce4b8b0 | 809 | if (list_empty(&ctx->cq_overflow_list)) { |
10988a0a | 810 | set_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq); |
3a4b89a2 | 811 | atomic_or(IORING_SQ_CQ_OVERFLOW, &ctx->rings->sq_flags); |
20c0b380 | 812 | |
cce4b8b0 | 813 | } |
d4d19c19 | 814 | ocqe->cqe.user_data = user_data; |
cce4b8b0 PB |
815 | ocqe->cqe.res = res; |
816 | ocqe->cqe.flags = cflags; | |
e45a3e05 SR |
817 | if (is_cqe32) { |
818 | ocqe->cqe.big_cqe[0] = extra1; | |
819 | ocqe->cqe.big_cqe[1] = extra2; | |
820 | } | |
cce4b8b0 PB |
821 | list_add_tail(&ocqe->list, &ctx->cq_overflow_list); |
822 | return true; | |
2b188cc1 JA |
823 | } |
824 | ||
056695bf | 825 | void io_req_cqe_overflow(struct io_kiocb *req) |
68494a65 | 826 | { |
056695bf PB |
827 | io_cqring_event_overflow(req->ctx, req->cqe.user_data, |
828 | req->cqe.res, req->cqe.flags, | |
b24c5d75 PB |
829 | req->big_cqe.extra1, req->big_cqe.extra2); |
830 | memset(&req->big_cqe, 0, sizeof(req->big_cqe)); | |
68494a65 PB |
831 | } |
832 | ||
faf88dde PB |
833 | /* |
834 | * writes to the cq entry need to come after reading head; the | |
835 | * control dependency is enough as we're using WRITE_ONCE to | |
836 | * fill the cq entry | |
837 | */ | |
20d6b633 | 838 | bool io_cqe_cache_refill(struct io_ring_ctx *ctx, bool overflow) |
faf88dde PB |
839 | { |
840 | struct io_rings *rings = ctx->rings; | |
841 | unsigned int off = ctx->cached_cq_tail & (ctx->cq_entries - 1); | |
faf88dde PB |
842 | unsigned int free, queued, len; |
843 | ||
aa1df3a3 PB |
844 | /* |
845 | * Posting into the CQ when there are pending overflowed CQEs may break | |
846 | * ordering guarantees, which will affect links, F_MORE users and more. | |
847 | * Force overflow the completion. | |
848 | */ | |
849 | if (!overflow && (ctx->check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))) | |
20d6b633 | 850 | return false; |
faf88dde PB |
851 | |
852 | /* userspace may cheat modifying the tail, be safe and do min */ | |
853 | queued = min(__io_cqring_events(ctx), ctx->cq_entries); | |
854 | free = ctx->cq_entries - queued; | |
855 | /* we need a contiguous range, limit based on the current array offset */ | |
856 | len = min(free, ctx->cq_entries - off); | |
857 | if (!len) | |
20d6b633 | 858 | return false; |
faf88dde | 859 | |
b3659a65 PB |
860 | if (ctx->flags & IORING_SETUP_CQE32) { |
861 | off <<= 1; | |
862 | len <<= 1; | |
863 | } | |
864 | ||
faf88dde PB |
865 | ctx->cqe_cached = &rings->cqes[off]; |
866 | ctx->cqe_sentinel = ctx->cqe_cached + len; | |
20d6b633 | 867 | return true; |
faf88dde PB |
868 | } |
869 | ||
f66f7342 PB |
870 | static bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res, |
871 | u32 cflags) | |
bcda7baa | 872 | { |
cd94903d PB |
873 | struct io_uring_cqe *cqe; |
874 | ||
913a571a | 875 | ctx->cq_extra++; |
cd94903d PB |
876 | |
877 | /* | |
878 | * If we can't get a cq entry, userspace overflowed the | |
879 | * submission (by quite a lot). Increment the overflow count in | |
880 | * the ring. | |
881 | */ | |
59fbc409 | 882 | if (likely(io_get_cqe(ctx, &cqe))) { |
e0486f3f DY |
883 | trace_io_uring_complete(ctx, NULL, user_data, res, cflags, 0, 0); |
884 | ||
cd94903d PB |
885 | WRITE_ONCE(cqe->user_data, user_data); |
886 | WRITE_ONCE(cqe->res, res); | |
887 | WRITE_ONCE(cqe->flags, cflags); | |
c5595975 PB |
888 | |
889 | if (ctx->flags & IORING_SETUP_CQE32) { | |
890 | WRITE_ONCE(cqe->big_cqe[0], 0); | |
891 | WRITE_ONCE(cqe->big_cqe[1], 0); | |
892 | } | |
cd94903d PB |
893 | return true; |
894 | } | |
52120f0f | 895 | return false; |
bcda7baa JA |
896 | } |
897 | ||
931147dd DY |
898 | static void __io_flush_post_cqes(struct io_ring_ctx *ctx) |
899 | __must_hold(&ctx->uring_lock) | |
900 | { | |
901 | struct io_submit_state *state = &ctx->submit_state; | |
902 | unsigned int i; | |
903 | ||
904 | lockdep_assert_held(&ctx->uring_lock); | |
905 | for (i = 0; i < state->cqes_count; i++) { | |
0aa7aa5f | 906 | struct io_uring_cqe *cqe = &ctx->completion_cqes[i]; |
931147dd | 907 | |
f66f7342 | 908 | if (!io_fill_cqe_aux(ctx, cqe->user_data, cqe->res, cqe->flags)) { |
27122c07 | 909 | if (ctx->lockless_cq) { |
f66f7342 PB |
910 | spin_lock(&ctx->completion_lock); |
911 | io_cqring_event_overflow(ctx, cqe->user_data, | |
912 | cqe->res, cqe->flags, 0, 0); | |
913 | spin_unlock(&ctx->completion_lock); | |
914 | } else { | |
915 | io_cqring_event_overflow(ctx, cqe->user_data, | |
916 | cqe->res, cqe->flags, 0, 0); | |
917 | } | |
918 | } | |
931147dd DY |
919 | } |
920 | state->cqes_count = 0; | |
921 | } | |
922 | ||
b529c96a DY |
923 | static bool __io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags, |
924 | bool allow_overflow) | |
d245bca6 PB |
925 | { |
926 | bool filled; | |
927 | ||
25399321 | 928 | io_cq_lock(ctx); |
f66f7342 PB |
929 | filled = io_fill_cqe_aux(ctx, user_data, res, cflags); |
930 | if (!filled && allow_overflow) | |
931 | filled = io_cqring_event_overflow(ctx, user_data, res, cflags, 0, 0); | |
932 | ||
25399321 | 933 | io_cq_unlock_post(ctx); |
d245bca6 PB |
934 | return filled; |
935 | } | |
936 | ||
b529c96a DY |
937 | bool io_post_aux_cqe(struct io_ring_ctx *ctx, u64 user_data, s32 res, u32 cflags) |
938 | { | |
939 | return __io_post_aux_cqe(ctx, user_data, res, cflags, true); | |
940 | } | |
941 | ||
b6b2bb58 PB |
942 | /* |
943 | * A helper for multishot requests posting additional CQEs. | |
944 | * Should only be used from a task_work including IO_URING_F_MULTISHOT. | |
945 | */ | |
946 | bool io_fill_cqe_req_aux(struct io_kiocb *req, bool defer, s32 res, u32 cflags) | |
2b188cc1 | 947 | { |
d86eaed1 JA |
948 | struct io_ring_ctx *ctx = req->ctx; |
949 | u64 user_data = req->cqe.user_data; | |
9b8c5475 | 950 | struct io_uring_cqe *cqe; |
9b8c5475 DY |
951 | |
952 | if (!defer) | |
b6b2bb58 | 953 | return __io_post_aux_cqe(ctx, user_data, res, cflags, false); |
9b8c5475 | 954 | |
9b8c5475 DY |
955 | lockdep_assert_held(&ctx->uring_lock); |
956 | ||
0aa7aa5f | 957 | if (ctx->submit_state.cqes_count == ARRAY_SIZE(ctx->completion_cqes)) { |
f66f7342 | 958 | __io_cq_lock(ctx); |
9b8c5475 DY |
959 | __io_flush_post_cqes(ctx); |
960 | /* no need to flush - flush is deferred */ | |
f66f7342 | 961 | __io_cq_unlock_post(ctx); |
9b8c5475 DY |
962 | } |
963 | ||
964 | /* For defered completions this is not as strict as it is otherwise, | |
965 | * however it's main job is to prevent unbounded posted completions, | |
966 | * and in that it works just as well. | |
967 | */ | |
b6b2bb58 | 968 | if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)) |
9b8c5475 DY |
969 | return false; |
970 | ||
0aa7aa5f | 971 | cqe = &ctx->completion_cqes[ctx->submit_state.cqes_count++]; |
9b8c5475 DY |
972 | cqe->user_data = user_data; |
973 | cqe->res = res; | |
974 | cqe->flags = cflags; | |
975 | return true; | |
976 | } | |
977 | ||
ef8ae64f | 978 | static void __io_req_complete_post(struct io_kiocb *req, unsigned issue_flags) |
2b188cc1 | 979 | { |
fa18fa22 | 980 | struct io_ring_ctx *ctx = req->ctx; |
2ad4c6d0 | 981 | struct io_rsrc_node *rsrc_node = NULL; |
fa18fa22 PB |
982 | |
983 | io_cq_lock(ctx); | |
00b0db56 PB |
984 | if (!(req->flags & REQ_F_CQE_SKIP)) { |
985 | if (!io_fill_cqe_req(ctx, req)) | |
986 | io_req_cqe_overflow(req); | |
987 | } | |
fa18fa22 | 988 | |
c7dae4ba JA |
989 | /* |
990 | * If we're the last reference to this request, add to our locked | |
991 | * free_list cache. | |
992 | */ | |
de9b4cca | 993 | if (req_ref_put_and_test(req)) { |
da1a08c5 | 994 | if (req->flags & IO_REQ_LINK_FLAGS) { |
0756a869 | 995 | if (req->flags & IO_DISARM_MASK) |
7a612350 PB |
996 | io_disarm_next(req); |
997 | if (req->link) { | |
998 | io_req_task_queue(req->link); | |
999 | req->link = NULL; | |
1000 | } | |
1001 | } | |
68a2cc1b | 1002 | io_put_kbuf_comp(req); |
3b7a612f PB |
1003 | if (unlikely(req->flags & IO_REQ_CLEAN_FLAGS)) |
1004 | io_clean_op(req); | |
17bc2837 | 1005 | io_put_file(req); |
3b7a612f | 1006 | |
2ad4c6d0 | 1007 | rsrc_node = req->rsrc_node; |
8197b053 PB |
1008 | /* |
1009 | * Selected buffer deallocation in io_clean_op() assumes that | |
1010 | * we don't hold ->completion_lock. Clean them here to avoid | |
1011 | * deadlocks. | |
1012 | */ | |
2fdd6fb5 | 1013 | io_put_task_remote(req->task); |
c2b6c6bc | 1014 | wq_list_add_head(&req->comp_list, &ctx->locked_free_list); |
d0acdee2 | 1015 | ctx->locked_free_nr++; |
180f829f | 1016 | } |
25399321 | 1017 | io_cq_unlock_post(ctx); |
2ad4c6d0 | 1018 | |
ef8ae64f PB |
1019 | if (rsrc_node) { |
1020 | io_ring_submit_lock(ctx, issue_flags); | |
1f2c8f61 | 1021 | io_put_rsrc_node(ctx, rsrc_node); |
ef8ae64f PB |
1022 | io_ring_submit_unlock(ctx, issue_flags); |
1023 | } | |
4e3d9ff9 JA |
1024 | } |
1025 | ||
1bec951c | 1026 | void io_req_complete_post(struct io_kiocb *req, unsigned issue_flags) |
bcda7baa | 1027 | { |
860e1c7f | 1028 | if (req->ctx->task_complete && req->ctx->submitter_task != current) { |
e6aeb272 PB |
1029 | req->io_task_work.func = io_req_task_complete; |
1030 | io_req_task_work_add(req); | |
1031 | } else if (!(issue_flags & IO_URING_F_UNLOCKED) || | |
1032 | !(req->ctx->flags & IORING_SETUP_IOPOLL)) { | |
ef8ae64f | 1033 | __io_req_complete_post(req, issue_flags); |
1bec951c PB |
1034 | } else { |
1035 | struct io_ring_ctx *ctx = req->ctx; | |
1036 | ||
1037 | mutex_lock(&ctx->uring_lock); | |
ef8ae64f | 1038 | __io_req_complete_post(req, issue_flags & ~IO_URING_F_UNLOCKED); |
1bec951c PB |
1039 | mutex_unlock(&ctx->uring_lock); |
1040 | } | |
0ddf92e8 JA |
1041 | } |
1042 | ||
973fc83f | 1043 | void io_req_defer_failed(struct io_kiocb *req, s32 res) |
e276ae34 | 1044 | __must_hold(&ctx->uring_lock) |
f41db273 | 1045 | { |
f30bd4d0 | 1046 | const struct io_cold_def *def = &io_cold_defs[req->opcode]; |
a47b255e | 1047 | |
e276ae34 PB |
1048 | lockdep_assert_held(&req->ctx->uring_lock); |
1049 | ||
93d2bcd2 | 1050 | req_set_fail(req); |
97b388d7 | 1051 | io_req_set_res(req, res, io_put_kbuf(req, IO_URING_F_UNLOCKED)); |
a47b255e PB |
1052 | if (def->fail) |
1053 | def->fail(req); | |
973fc83f | 1054 | io_req_complete_defer(req); |
f41db273 PB |
1055 | } |
1056 | ||
864ea921 PB |
1057 | /* |
1058 | * Don't initialise the fields below on every allocation, but do that in | |
1059 | * advance and keep them valid across allocations. | |
1060 | */ | |
1061 | static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx) | |
1062 | { | |
1063 | req->ctx = ctx; | |
1064 | req->link = NULL; | |
1065 | req->async_data = NULL; | |
1066 | /* not necessary, but safer to zero */ | |
31d3ba92 | 1067 | memset(&req->cqe, 0, sizeof(req->cqe)); |
b24c5d75 | 1068 | memset(&req->big_cqe, 0, sizeof(req->big_cqe)); |
864ea921 PB |
1069 | } |
1070 | ||
dac7a098 | 1071 | static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx, |
cd0ca2e0 | 1072 | struct io_submit_state *state) |
dac7a098 | 1073 | { |
79ebeaee | 1074 | spin_lock(&ctx->completion_lock); |
c2b6c6bc | 1075 | wq_list_splice(&ctx->locked_free_list, &state->free_list); |
d0acdee2 | 1076 | ctx->locked_free_nr = 0; |
79ebeaee | 1077 | spin_unlock(&ctx->completion_lock); |
dac7a098 PB |
1078 | } |
1079 | ||
5d5901a3 PB |
1080 | /* |
1081 | * A request might get retired back into the request caches even before opcode | |
1082 | * handlers and io_issue_sqe() are done with it, e.g. inline completion path. | |
1083 | * Because of that, io_alloc_req() should be called only under ->uring_lock | |
1084 | * and with extra caution to not get a request that is still worked on. | |
1085 | */ | |
bd1a3783 | 1086 | __cold bool __io_alloc_req_refill(struct io_ring_ctx *ctx) |
5d5901a3 | 1087 | __must_hold(&ctx->uring_lock) |
2b188cc1 | 1088 | { |
864ea921 | 1089 | gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; |
3ab665b7 | 1090 | void *reqs[IO_REQ_ALLOC_BATCH]; |
864ea921 | 1091 | int ret, i; |
e5d1bc0a | 1092 | |
23a5c43b PB |
1093 | /* |
1094 | * If we have more than a batch's worth of requests in our IRQ side | |
1095 | * locked cache, grab the lock and move them over to our submission | |
1096 | * side cache. | |
1097 | */ | |
a6d97a8a | 1098 | if (data_race(ctx->locked_free_nr) > IO_COMPL_BATCH) { |
23a5c43b | 1099 | io_flush_cached_locked_reqs(ctx, &ctx->submit_state); |
88ab95be | 1100 | if (!io_req_cache_empty(ctx)) |
23a5c43b PB |
1101 | return true; |
1102 | } | |
e5d1bc0a | 1103 | |
3ab665b7 | 1104 | ret = kmem_cache_alloc_bulk(req_cachep, gfp, ARRAY_SIZE(reqs), reqs); |
fd6fab2c | 1105 | |
864ea921 PB |
1106 | /* |
1107 | * Bulk alloc is all-or-nothing. If we fail to get a batch, | |
1108 | * retry single alloc to be on the safe side. | |
1109 | */ | |
1110 | if (unlikely(ret <= 0)) { | |
3ab665b7 PB |
1111 | reqs[0] = kmem_cache_alloc(req_cachep, gfp); |
1112 | if (!reqs[0]) | |
a33ae9ce | 1113 | return false; |
864ea921 | 1114 | ret = 1; |
2b188cc1 | 1115 | } |
864ea921 | 1116 | |
37f0e767 | 1117 | percpu_ref_get_many(&ctx->refs, ret); |
3ab665b7 | 1118 | for (i = 0; i < ret; i++) { |
23a5c43b | 1119 | struct io_kiocb *req = reqs[i]; |
3ab665b7 PB |
1120 | |
1121 | io_preinit_req(req, ctx); | |
fa05457a | 1122 | io_req_add_to_cache(req, ctx); |
3ab665b7 | 1123 | } |
a33ae9ce PB |
1124 | return true; |
1125 | } | |
1126 | ||
03adabe8 PB |
1127 | __cold void io_free_req(struct io_kiocb *req) |
1128 | { | |
6ec9afc7 PB |
1129 | /* refs were already put, restore them for io_req_task_complete() */ |
1130 | req->flags &= ~REQ_F_REFCOUNT; | |
1131 | /* we only want to free it, don't post CQEs */ | |
1132 | req->flags |= REQ_F_CQE_SKIP; | |
1133 | req->io_task_work.func = io_req_task_complete; | |
03adabe8 PB |
1134 | io_req_task_work_add(req); |
1135 | } | |
1136 | ||
d81499bf PB |
1137 | static void __io_req_find_next_prep(struct io_kiocb *req) |
1138 | { | |
1139 | struct io_ring_ctx *ctx = req->ctx; | |
d81499bf | 1140 | |
6971253f | 1141 | spin_lock(&ctx->completion_lock); |
305bef98 | 1142 | io_disarm_next(req); |
6971253f | 1143 | spin_unlock(&ctx->completion_lock); |
d81499bf PB |
1144 | } |
1145 | ||
1146 | static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req) | |
c69f8dbe | 1147 | { |
33cc89a9 | 1148 | struct io_kiocb *nxt; |
944e58bf | 1149 | |
9e645e11 JA |
1150 | /* |
1151 | * If LINK is set, we have dependent requests in this chain. If we | |
1152 | * didn't fail this request, queue the first one up, moving any other | |
1153 | * dependencies to the next request. In case of failure, fail the rest | |
1154 | * of the chain. | |
1155 | */ | |
d81499bf PB |
1156 | if (unlikely(req->flags & IO_DISARM_MASK)) |
1157 | __io_req_find_next_prep(req); | |
33cc89a9 PB |
1158 | nxt = req->link; |
1159 | req->link = NULL; | |
1160 | return nxt; | |
4d7dd462 | 1161 | } |
9e645e11 | 1162 | |
a282967c | 1163 | static void ctx_flush_and_put(struct io_ring_ctx *ctx, struct io_tw_state *ts) |
2c32395d PB |
1164 | { |
1165 | if (!ctx) | |
1166 | return; | |
ef060ea9 JA |
1167 | if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) |
1168 | atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); | |
a282967c | 1169 | if (ts->locked) { |
c450178d | 1170 | io_submit_flush_completions(ctx); |
2c32395d | 1171 | mutex_unlock(&ctx->uring_lock); |
a282967c | 1172 | ts->locked = false; |
2c32395d PB |
1173 | } |
1174 | percpu_ref_put(&ctx->refs); | |
1175 | } | |
1176 | ||
c6dd763c | 1177 | static unsigned int handle_tw_list(struct llist_node *node, |
a282967c PB |
1178 | struct io_ring_ctx **ctx, |
1179 | struct io_tw_state *ts, | |
c6dd763c | 1180 | struct llist_node *last) |
9f8d032a | 1181 | { |
c6dd763c DY |
1182 | unsigned int count = 0; |
1183 | ||
cb6bf7f2 | 1184 | while (node && node != last) { |
f88262e6 | 1185 | struct llist_node *next = node->next; |
9f8d032a HX |
1186 | struct io_kiocb *req = container_of(node, struct io_kiocb, |
1187 | io_task_work.node); | |
1188 | ||
34d2bfe7 JA |
1189 | prefetch(container_of(next, struct io_kiocb, io_task_work.node)); |
1190 | ||
9f8d032a | 1191 | if (req->ctx != *ctx) { |
a282967c | 1192 | ctx_flush_and_put(*ctx, ts); |
9f8d032a HX |
1193 | *ctx = req->ctx; |
1194 | /* if not contended, grab and improve batching */ | |
a282967c | 1195 | ts->locked = mutex_trylock(&(*ctx)->uring_lock); |
9f8d032a | 1196 | percpu_ref_get(&(*ctx)->refs); |
13bfa6f1 | 1197 | } |
c92fcfc2 JA |
1198 | INDIRECT_CALL_2(req->io_task_work.func, |
1199 | io_poll_task_func, io_req_rw_complete, | |
1200 | req, ts); | |
9f8d032a | 1201 | node = next; |
c6dd763c | 1202 | count++; |
f5868008 | 1203 | if (unlikely(need_resched())) { |
a282967c | 1204 | ctx_flush_and_put(*ctx, ts); |
f5868008 JA |
1205 | *ctx = NULL; |
1206 | cond_resched(); | |
1207 | } | |
3a0c037b | 1208 | } |
c6dd763c DY |
1209 | |
1210 | return count; | |
9f8d032a HX |
1211 | } |
1212 | ||
923d1592 DY |
1213 | /** |
1214 | * io_llist_xchg - swap all entries in a lock-less list | |
1215 | * @head: the head of lock-less list to delete all entries | |
1216 | * @new: new entry as the head of the list | |
1217 | * | |
1218 | * If list is empty, return NULL, otherwise, return the pointer to the first entry. | |
1219 | * The order of entries returned is from the newest to the oldest added one. | |
1220 | */ | |
1221 | static inline struct llist_node *io_llist_xchg(struct llist_head *head, | |
1222 | struct llist_node *new) | |
1223 | { | |
1224 | return xchg(&head->first, new); | |
1225 | } | |
1226 | ||
1227 | /** | |
1228 | * io_llist_cmpxchg - possibly swap all entries in a lock-less list | |
1229 | * @head: the head of lock-less list to delete all entries | |
1230 | * @old: expected old value of the first entry of the list | |
1231 | * @new: new entry as the head of the list | |
1232 | * | |
1233 | * perform a cmpxchg on the first entry of the list. | |
1234 | */ | |
1235 | ||
1236 | static inline struct llist_node *io_llist_cmpxchg(struct llist_head *head, | |
1237 | struct llist_node *old, | |
1238 | struct llist_node *new) | |
1239 | { | |
1240 | return cmpxchg(&head->first, old, new); | |
1241 | } | |
1242 | ||
dfbe5561 | 1243 | static __cold void io_fallback_tw(struct io_uring_task *tctx, bool sync) |
10e1c0d5 JA |
1244 | { |
1245 | struct llist_node *node = llist_del_all(&tctx->task_list); | |
dfbe5561 | 1246 | struct io_ring_ctx *last_ctx = NULL; |
10e1c0d5 JA |
1247 | struct io_kiocb *req; |
1248 | ||
1249 | while (node) { | |
1250 | req = container_of(node, struct io_kiocb, io_task_work.node); | |
1251 | node = node->next; | |
dfbe5561 JA |
1252 | if (sync && last_ctx != req->ctx) { |
1253 | if (last_ctx) { | |
1254 | flush_delayed_work(&last_ctx->fallback_work); | |
1255 | percpu_ref_put(&last_ctx->refs); | |
1256 | } | |
1257 | last_ctx = req->ctx; | |
1258 | percpu_ref_get(&last_ctx->refs); | |
1259 | } | |
10e1c0d5 JA |
1260 | if (llist_add(&req->io_task_work.node, |
1261 | &req->ctx->fallback_llist)) | |
1262 | schedule_delayed_work(&req->ctx->fallback_work, 1); | |
1263 | } | |
dfbe5561 JA |
1264 | |
1265 | if (last_ctx) { | |
1266 | flush_delayed_work(&last_ctx->fallback_work); | |
1267 | percpu_ref_put(&last_ctx->refs); | |
1268 | } | |
10e1c0d5 JA |
1269 | } |
1270 | ||
c9f06aa7 | 1271 | void tctx_task_work(struct callback_head *cb) |
c40f6379 | 1272 | { |
a282967c | 1273 | struct io_tw_state ts = {}; |
ebd0df2e | 1274 | struct io_ring_ctx *ctx = NULL; |
3f18407d PB |
1275 | struct io_uring_task *tctx = container_of(cb, struct io_uring_task, |
1276 | task_work); | |
3a0c037b | 1277 | struct llist_node fake = {}; |
77e443ab | 1278 | struct llist_node *node; |
cb6bf7f2 PB |
1279 | unsigned int loops = 0; |
1280 | unsigned int count = 0; | |
3a0c037b | 1281 | |
77e443ab | 1282 | if (unlikely(current->flags & PF_EXITING)) { |
dfbe5561 | 1283 | io_fallback_tw(tctx, true); |
77e443ab PB |
1284 | return; |
1285 | } | |
3a0c037b | 1286 | |
cb6bf7f2 | 1287 | do { |
c6dd763c | 1288 | loops++; |
3a0c037b | 1289 | node = io_llist_xchg(&tctx->task_list, &fake); |
a282967c | 1290 | count += handle_tw_list(node, &ctx, &ts, &fake); |
50470fc5 PB |
1291 | |
1292 | /* skip expensive cmpxchg if there are items in the list */ | |
1293 | if (READ_ONCE(tctx->task_list.first) != &fake) | |
1294 | continue; | |
a282967c | 1295 | if (ts.locked && !wq_list_empty(&ctx->submit_state.compl_reqs)) { |
50470fc5 PB |
1296 | io_submit_flush_completions(ctx); |
1297 | if (READ_ONCE(tctx->task_list.first) != &fake) | |
1298 | continue; | |
1299 | } | |
3a0c037b | 1300 | node = io_llist_cmpxchg(&tctx->task_list, &fake, NULL); |
cb6bf7f2 | 1301 | } while (node != &fake); |
ebd0df2e | 1302 | |
a282967c | 1303 | ctx_flush_and_put(ctx, &ts); |
3cc7fdb9 | 1304 | |
8d664282 JA |
1305 | /* relaxed read is enough as only the task itself sets ->in_cancel */ |
1306 | if (unlikely(atomic_read(&tctx->in_cancel))) | |
3cc7fdb9 | 1307 | io_uring_drop_tctx_refs(current); |
c6dd763c DY |
1308 | |
1309 | trace_io_uring_task_work_run(tctx, count, loops); | |
7cbf1722 JA |
1310 | } |
1311 | ||
91c7884a | 1312 | static inline void io_req_local_work_add(struct io_kiocb *req, unsigned flags) |
c0e0d6ba DY |
1313 | { |
1314 | struct io_ring_ctx *ctx = req->ctx; | |
8751d154 | 1315 | unsigned nr_wait, nr_tw, nr_tw_prev; |
e8c40771 | 1316 | struct llist_node *head; |
c0e0d6ba | 1317 | |
b4bc35cf PB |
1318 | /* See comment above IO_CQ_WAKE_INIT */ |
1319 | BUILD_BUG_ON(IO_CQ_WAKE_FORCE <= IORING_MAX_CQ_ENTRIES); | |
c0e0d6ba | 1320 | |
b4bc35cf PB |
1321 | /* |
1322 | * We don't know how many reuqests is there in the link and whether | |
1323 | * they can even be queued lazily, fall back to non-lazy. | |
1324 | */ | |
8751d154 PB |
1325 | if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) |
1326 | flags &= ~IOU_F_TWQ_LAZY_WAKE; | |
ce8e04f6 | 1327 | |
e8c40771 | 1328 | head = READ_ONCE(ctx->work_llist.first); |
51509400 | 1329 | do { |
8751d154 | 1330 | nr_tw_prev = 0; |
e8c40771 PB |
1331 | if (head) { |
1332 | struct io_kiocb *first_req = container_of(head, | |
8751d154 PB |
1333 | struct io_kiocb, |
1334 | io_task_work.node); | |
1335 | /* | |
1336 | * Might be executed at any moment, rely on | |
1337 | * SLAB_TYPESAFE_BY_RCU to keep it alive. | |
1338 | */ | |
1339 | nr_tw_prev = READ_ONCE(first_req->nr_tw); | |
1340 | } | |
b4bc35cf PB |
1341 | |
1342 | /* | |
1343 | * Theoretically, it can overflow, but that's fine as one of | |
1344 | * previous adds should've tried to wake the task. | |
1345 | */ | |
8751d154 | 1346 | nr_tw = nr_tw_prev + 1; |
8751d154 | 1347 | if (!(flags & IOU_F_TWQ_LAZY_WAKE)) |
b4bc35cf | 1348 | nr_tw = IO_CQ_WAKE_FORCE; |
8751d154 PB |
1349 | |
1350 | req->nr_tw = nr_tw; | |
e8c40771 PB |
1351 | req->io_task_work.node.next = head; |
1352 | } while (!try_cmpxchg(&ctx->work_llist.first, &head, | |
51509400 PB |
1353 | &req->io_task_work.node)); |
1354 | ||
d381099f PB |
1355 | /* |
1356 | * cmpxchg implies a full barrier, which pairs with the barrier | |
1357 | * in set_current_state() on the io_cqring_wait() side. It's used | |
1358 | * to ensure that either we see updated ->cq_wait_nr, or waiters | |
1359 | * going to sleep will observe the work added to the list, which | |
1360 | * is similar to the wait/wawke task state sync. | |
1361 | */ | |
1362 | ||
e8c40771 | 1363 | if (!head) { |
8751d154 PB |
1364 | if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) |
1365 | atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); | |
1366 | if (ctx->has_evfd) | |
1367 | io_eventfd_signal(ctx); | |
c0e0d6ba DY |
1368 | } |
1369 | ||
8751d154 | 1370 | nr_wait = atomic_read(&ctx->cq_wait_nr); |
b4bc35cf PB |
1371 | /* not enough or no one is waiting */ |
1372 | if (nr_tw < nr_wait) | |
8751d154 | 1373 | return; |
b4bc35cf PB |
1374 | /* the previous add has already woken it up */ |
1375 | if (nr_tw_prev >= nr_wait) | |
8751d154 | 1376 | return; |
8751d154 | 1377 | wake_up_state(ctx->submitter_task, TASK_INTERRUPTIBLE); |
c0e0d6ba DY |
1378 | } |
1379 | ||
91c7884a | 1380 | static void io_req_normal_work_add(struct io_kiocb *req) |
7cbf1722 | 1381 | { |
c34398a8 | 1382 | struct io_uring_task *tctx = req->task->io_uring; |
9f010507 | 1383 | struct io_ring_ctx *ctx = req->ctx; |
7cbf1722 | 1384 | |
7cbf1722 | 1385 | /* task_work already pending, we're done */ |
32d91f05 | 1386 | if (!llist_add(&req->io_task_work.node, &tctx->task_list)) |
e09ee510 | 1387 | return; |
7cbf1722 | 1388 | |
ef060ea9 JA |
1389 | if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) |
1390 | atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); | |
1391 | ||
3fe07bcd | 1392 | if (likely(!task_work_add(req->task, &tctx->task_work, ctx->notify_method))) |
e09ee510 | 1393 | return; |
2215bed9 | 1394 | |
dfbe5561 | 1395 | io_fallback_tw(tctx, false); |
c0e0d6ba DY |
1396 | } |
1397 | ||
91c7884a PB |
1398 | void __io_req_task_work_add(struct io_kiocb *req, unsigned flags) |
1399 | { | |
1400 | if (req->ctx->flags & IORING_SETUP_DEFER_TASKRUN) { | |
1401 | rcu_read_lock(); | |
1402 | io_req_local_work_add(req, flags); | |
1403 | rcu_read_unlock(); | |
1404 | } else { | |
1405 | io_req_normal_work_add(req); | |
1406 | } | |
1407 | } | |
1408 | ||
c0e0d6ba DY |
1409 | static void __cold io_move_task_work_from_local(struct io_ring_ctx *ctx) |
1410 | { | |
1411 | struct llist_node *node; | |
1412 | ||
1413 | node = llist_del_all(&ctx->work_llist); | |
1414 | while (node) { | |
1415 | struct io_kiocb *req = container_of(node, struct io_kiocb, | |
1416 | io_task_work.node); | |
1417 | ||
1418 | node = node->next; | |
91c7884a | 1419 | io_req_normal_work_add(req); |
c0e0d6ba DY |
1420 | } |
1421 | } | |
1422 | ||
a282967c | 1423 | static int __io_run_local_work(struct io_ring_ctx *ctx, struct io_tw_state *ts) |
c0e0d6ba | 1424 | { |
c0e0d6ba | 1425 | struct llist_node *node; |
c3f4d39e | 1426 | unsigned int loops = 0; |
140102ae | 1427 | int ret = 0; |
c0e0d6ba | 1428 | |
140102ae | 1429 | if (WARN_ON_ONCE(ctx->submitter_task != current)) |
c0e0d6ba | 1430 | return -EEXIST; |
c3f4d39e PB |
1431 | if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) |
1432 | atomic_andnot(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); | |
c0e0d6ba | 1433 | again: |
3af0356c JA |
1434 | /* |
1435 | * llists are in reverse order, flip it back the right way before | |
1436 | * running the pending items. | |
1437 | */ | |
1438 | node = llist_reverse_order(io_llist_xchg(&ctx->work_llist, NULL)); | |
c3f4d39e | 1439 | while (node) { |
c0e0d6ba DY |
1440 | struct llist_node *next = node->next; |
1441 | struct io_kiocb *req = container_of(node, struct io_kiocb, | |
1442 | io_task_work.node); | |
1443 | prefetch(container_of(next, struct io_kiocb, io_task_work.node)); | |
c92fcfc2 JA |
1444 | INDIRECT_CALL_2(req->io_task_work.func, |
1445 | io_poll_task_func, io_req_rw_complete, | |
1446 | req, ts); | |
c0e0d6ba DY |
1447 | ret++; |
1448 | node = next; | |
1449 | } | |
c3f4d39e | 1450 | loops++; |
c0e0d6ba | 1451 | |
c3f4d39e | 1452 | if (!llist_empty(&ctx->work_llist)) |
c0e0d6ba | 1453 | goto again; |
a282967c | 1454 | if (ts->locked) { |
c0e0d6ba | 1455 | io_submit_flush_completions(ctx); |
b0b7a7d2 PB |
1456 | if (!llist_empty(&ctx->work_llist)) |
1457 | goto again; | |
1458 | } | |
f75d5036 | 1459 | trace_io_uring_local_work_run(ctx, ret, loops); |
c0e0d6ba | 1460 | return ret; |
8ac5d85a JA |
1461 | } |
1462 | ||
360173ab PB |
1463 | static inline int io_run_local_work_locked(struct io_ring_ctx *ctx) |
1464 | { | |
a282967c | 1465 | struct io_tw_state ts = { .locked = true, }; |
360173ab PB |
1466 | int ret; |
1467 | ||
1468 | if (llist_empty(&ctx->work_llist)) | |
1469 | return 0; | |
1470 | ||
a282967c | 1471 | ret = __io_run_local_work(ctx, &ts); |
360173ab | 1472 | /* shouldn't happen! */ |
a282967c | 1473 | if (WARN_ON_ONCE(!ts.locked)) |
360173ab PB |
1474 | mutex_lock(&ctx->uring_lock); |
1475 | return ret; | |
1476 | } | |
1477 | ||
3e565555 | 1478 | static int io_run_local_work(struct io_ring_ctx *ctx) |
8ac5d85a | 1479 | { |
a282967c | 1480 | struct io_tw_state ts = {}; |
8ac5d85a JA |
1481 | int ret; |
1482 | ||
a282967c PB |
1483 | ts.locked = mutex_trylock(&ctx->uring_lock); |
1484 | ret = __io_run_local_work(ctx, &ts); | |
1485 | if (ts.locked) | |
8ac5d85a JA |
1486 | mutex_unlock(&ctx->uring_lock); |
1487 | ||
1488 | return ret; | |
c0e0d6ba DY |
1489 | } |
1490 | ||
a282967c | 1491 | static void io_req_task_cancel(struct io_kiocb *req, struct io_tw_state *ts) |
c40f6379 | 1492 | { |
a282967c | 1493 | io_tw_lock(req->ctx, ts); |
973fc83f | 1494 | io_req_defer_failed(req, req->cqe.res); |
c40f6379 JA |
1495 | } |
1496 | ||
a282967c | 1497 | void io_req_task_submit(struct io_kiocb *req, struct io_tw_state *ts) |
c40f6379 | 1498 | { |
a282967c | 1499 | io_tw_lock(req->ctx, ts); |
316319e8 | 1500 | /* req->task == current here, checking PF_EXITING is safe */ |
6bb30855 | 1501 | if (unlikely(req->task->flags & PF_EXITING)) |
973fc83f | 1502 | io_req_defer_failed(req, -EFAULT); |
6bb30855 | 1503 | else if (req->flags & REQ_F_FORCE_ASYNC) |
a282967c | 1504 | io_queue_iowq(req, ts); |
6bb30855 DY |
1505 | else |
1506 | io_queue_sqe(req); | |
c40f6379 JA |
1507 | } |
1508 | ||
59915143 | 1509 | void io_req_task_queue_fail(struct io_kiocb *req, int ret) |
c40f6379 | 1510 | { |
97b388d7 | 1511 | io_req_set_res(req, ret, 0); |
5b0a6acc | 1512 | req->io_task_work.func = io_req_task_cancel; |
3fe07bcd | 1513 | io_req_task_work_add(req); |
c40f6379 JA |
1514 | } |
1515 | ||
f3b44f92 | 1516 | void io_req_task_queue(struct io_kiocb *req) |
a3df7698 | 1517 | { |
5b0a6acc | 1518 | req->io_task_work.func = io_req_task_submit; |
3fe07bcd | 1519 | io_req_task_work_add(req); |
a3df7698 PB |
1520 | } |
1521 | ||
59915143 | 1522 | void io_queue_next(struct io_kiocb *req) |
c69f8dbe | 1523 | { |
9b5f7bd9 | 1524 | struct io_kiocb *nxt = io_req_find_next(req); |
944e58bf PB |
1525 | |
1526 | if (nxt) | |
906a8c3f | 1527 | io_req_task_queue(nxt); |
c69f8dbe JL |
1528 | } |
1529 | ||
ec26c225 PB |
1530 | static void io_free_batch_list(struct io_ring_ctx *ctx, |
1531 | struct io_wq_work_node *node) | |
3aa83bfb | 1532 | __must_hold(&ctx->uring_lock) |
5af1d13e | 1533 | { |
3aa83bfb PB |
1534 | do { |
1535 | struct io_kiocb *req = container_of(node, struct io_kiocb, | |
1536 | comp_list); | |
2d6500d4 | 1537 | |
a538be5b PB |
1538 | if (unlikely(req->flags & IO_REQ_CLEAN_SLOW_FLAGS)) { |
1539 | if (req->flags & REQ_F_REFCOUNT) { | |
1540 | node = req->comp_list.next; | |
1541 | if (!req_ref_put_and_test(req)) | |
1542 | continue; | |
1543 | } | |
b605a7fa PB |
1544 | if ((req->flags & REQ_F_POLLED) && req->apoll) { |
1545 | struct async_poll *apoll = req->apoll; | |
1546 | ||
1547 | if (apoll->double_poll) | |
1548 | kfree(apoll->double_poll); | |
9731bc98 JA |
1549 | if (!io_alloc_cache_put(&ctx->apoll_cache, &apoll->cache)) |
1550 | kfree(apoll); | |
b605a7fa PB |
1551 | req->flags &= ~REQ_F_POLLED; |
1552 | } | |
da1a08c5 | 1553 | if (req->flags & IO_REQ_LINK_FLAGS) |
57859f4d | 1554 | io_queue_next(req); |
a538be5b PB |
1555 | if (unlikely(req->flags & IO_REQ_CLEAN_FLAGS)) |
1556 | io_clean_op(req); | |
c1e53a69 | 1557 | } |
17bc2837 | 1558 | io_put_file(req); |
2d6500d4 | 1559 | |
ab409402 | 1560 | io_req_put_rsrc_locked(req, ctx); |
5af1d13e | 1561 | |
2fdd6fb5 | 1562 | io_put_task(req->task); |
c1e53a69 | 1563 | node = req->comp_list.next; |
fa05457a | 1564 | io_req_add_to_cache(req, ctx); |
3aa83bfb | 1565 | } while (node); |
7a743e22 PB |
1566 | } |
1567 | ||
ec26c225 | 1568 | void __io_submit_flush_completions(struct io_ring_ctx *ctx) |
a141dd89 | 1569 | __must_hold(&ctx->uring_lock) |
905c172f | 1570 | { |
cd0ca2e0 | 1571 | struct io_submit_state *state = &ctx->submit_state; |
fa780334 | 1572 | struct io_wq_work_node *node; |
905c172f | 1573 | |
f66f7342 | 1574 | __io_cq_lock(ctx); |
931147dd DY |
1575 | /* must come first to preserve CQE ordering in failure cases */ |
1576 | if (state->cqes_count) | |
1577 | __io_flush_post_cqes(ctx); | |
fa780334 | 1578 | __wq_list_for_each(node, &state->compl_reqs) { |
d9dee430 PB |
1579 | struct io_kiocb *req = container_of(node, struct io_kiocb, |
1580 | comp_list); | |
3d4aeb9f | 1581 | |
f66f7342 | 1582 | if (!(req->flags & REQ_F_CQE_SKIP) && |
00b0db56 | 1583 | unlikely(!io_fill_cqe_req(ctx, req))) { |
27122c07 | 1584 | if (ctx->lockless_cq) { |
f66f7342 PB |
1585 | spin_lock(&ctx->completion_lock); |
1586 | io_req_cqe_overflow(req); | |
1587 | spin_unlock(&ctx->completion_lock); | |
1588 | } else { | |
1589 | io_req_cqe_overflow(req); | |
1590 | } | |
1591 | } | |
905c172f | 1592 | } |
c98c81a4 | 1593 | __io_cq_unlock_post(ctx); |
d9dee430 | 1594 | |
931147dd DY |
1595 | if (!wq_list_empty(&ctx->submit_state.compl_reqs)) { |
1596 | io_free_batch_list(ctx, state->compl_reqs.first); | |
1597 | INIT_WQ_LIST(&state->compl_reqs); | |
1598 | } | |
7a743e22 PB |
1599 | } |
1600 | ||
6c503150 | 1601 | static unsigned io_cqring_events(struct io_ring_ctx *ctx) |
a3a0e43f JA |
1602 | { |
1603 | /* See comment at the top of this file */ | |
1604 | smp_rmb(); | |
e23de15f | 1605 | return __io_cqring_events(ctx); |
a3a0e43f JA |
1606 | } |
1607 | ||
def596e9 JA |
1608 | /* |
1609 | * We can't just wait for polled events to come to us, we have to actively | |
1610 | * find and complete them. | |
1611 | */ | |
c072481d | 1612 | static __cold void io_iopoll_try_reap_events(struct io_ring_ctx *ctx) |
def596e9 JA |
1613 | { |
1614 | if (!(ctx->flags & IORING_SETUP_IOPOLL)) | |
1615 | return; | |
1616 | ||
1617 | mutex_lock(&ctx->uring_lock); | |
5eef4e87 | 1618 | while (!wq_list_empty(&ctx->iopoll_list)) { |
b2edc0a7 | 1619 | /* let it sleep and repeat later if can't complete a request */ |
5ba3c874 | 1620 | if (io_do_iopoll(ctx, true) == 0) |
b2edc0a7 | 1621 | break; |
08f5439f JA |
1622 | /* |
1623 | * Ensure we allow local-to-the-cpu processing to take place, | |
1624 | * in this case we need to ensure that we reap all events. | |
3fcee5a6 | 1625 | * Also let task_work, etc. to progress by releasing the mutex |
08f5439f | 1626 | */ |
3fcee5a6 PB |
1627 | if (need_resched()) { |
1628 | mutex_unlock(&ctx->uring_lock); | |
1629 | cond_resched(); | |
1630 | mutex_lock(&ctx->uring_lock); | |
1631 | } | |
def596e9 JA |
1632 | } |
1633 | mutex_unlock(&ctx->uring_lock); | |
1634 | } | |
1635 | ||
7668b92a | 1636 | static int io_iopoll_check(struct io_ring_ctx *ctx, long min) |
def596e9 | 1637 | { |
7668b92a | 1638 | unsigned int nr_events = 0; |
155bc950 | 1639 | unsigned long check_cq; |
500f9fba | 1640 | |
76de6749 PB |
1641 | if (!io_allowed_run_tw(ctx)) |
1642 | return -EEXIST; | |
1643 | ||
3a08576b PB |
1644 | check_cq = READ_ONCE(ctx->check_cq); |
1645 | if (unlikely(check_cq)) { | |
1646 | if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT)) | |
a85381d8 | 1647 | __io_cqring_overflow_flush(ctx); |
3a08576b PB |
1648 | /* |
1649 | * Similarly do not spin if we have not informed the user of any | |
1650 | * dropped CQE. | |
1651 | */ | |
1652 | if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) | |
1653 | return -EBADR; | |
1654 | } | |
f39c8a5b PB |
1655 | /* |
1656 | * Don't enter poll loop if we already have events pending. | |
1657 | * If we do, we can potentially be spinning for commands that | |
1658 | * already triggered a CQE (eg in error). | |
1659 | */ | |
f39c8a5b | 1660 | if (io_cqring_events(ctx)) |
d487b43c | 1661 | return 0; |
155bc950 | 1662 | |
def596e9 | 1663 | do { |
9e4bef2b JA |
1664 | int ret = 0; |
1665 | ||
500f9fba JA |
1666 | /* |
1667 | * If a submit got punted to a workqueue, we can have the | |
1668 | * application entering polling for a command before it gets | |
1669 | * issued. That app will hold the uring_lock for the duration | |
1670 | * of the poll right here, so we need to take a breather every | |
1671 | * now and then to ensure that the issue has a chance to add | |
1672 | * the poll to the issued list. Otherwise we can spin here | |
1673 | * forever, while the workqueue is stuck trying to acquire the | |
1674 | * very same mutex. | |
1675 | */ | |
dac6a0ea JA |
1676 | if (wq_list_empty(&ctx->iopoll_list) || |
1677 | io_task_work_pending(ctx)) { | |
8f487ef2 PB |
1678 | u32 tail = ctx->cached_cq_tail; |
1679 | ||
8de11cdc | 1680 | (void) io_run_local_work_locked(ctx); |
def596e9 | 1681 | |
dac6a0ea JA |
1682 | if (task_work_pending(current) || |
1683 | wq_list_empty(&ctx->iopoll_list)) { | |
dac6a0ea | 1684 | mutex_unlock(&ctx->uring_lock); |
9d54bd6a | 1685 | io_run_task_work(); |
dac6a0ea | 1686 | mutex_lock(&ctx->uring_lock); |
dac6a0ea | 1687 | } |
8f487ef2 PB |
1688 | /* some requests don't go through iopoll_list */ |
1689 | if (tail != ctx->cached_cq_tail || | |
5eef4e87 | 1690 | wq_list_empty(&ctx->iopoll_list)) |
e9979b36 | 1691 | break; |
500f9fba | 1692 | } |
5ba3c874 | 1693 | ret = io_do_iopoll(ctx, !min); |
9e4bef2b JA |
1694 | if (unlikely(ret < 0)) |
1695 | return ret; | |
dc314886 PB |
1696 | |
1697 | if (task_sigpending(current)) | |
1698 | return -EINTR; | |
9e4bef2b | 1699 | if (need_resched()) |
5ba3c874 | 1700 | break; |
d487b43c | 1701 | |
5ba3c874 | 1702 | nr_events += ret; |
9e4bef2b | 1703 | } while (nr_events < min); |
d487b43c | 1704 | |
9e4bef2b | 1705 | return 0; |
def596e9 | 1706 | } |
7012c815 | 1707 | |
a282967c | 1708 | void io_req_task_complete(struct io_kiocb *req, struct io_tw_state *ts) |
8ef12efe | 1709 | { |
a282967c | 1710 | if (ts->locked) |
9da070b1 | 1711 | io_req_complete_defer(req); |
7012c815 | 1712 | else |
27f35fe9 | 1713 | io_req_complete_post(req, IO_URING_F_UNLOCKED); |
8ef12efe JA |
1714 | } |
1715 | ||
def596e9 JA |
1716 | /* |
1717 | * After the iocb has been issued, it's safe to be found on the poll list. | |
1718 | * Adding the kiocb to the list AFTER submission ensures that we don't | |
f39c8a5b | 1719 | * find it from a io_do_iopoll() thread before the issuer is done |
def596e9 JA |
1720 | * accessing the kiocb cookie. |
1721 | */ | |
9882131c | 1722 | static void io_iopoll_req_issued(struct io_kiocb *req, unsigned int issue_flags) |
def596e9 JA |
1723 | { |
1724 | struct io_ring_ctx *ctx = req->ctx; | |
3b44b371 | 1725 | const bool needs_lock = issue_flags & IO_URING_F_UNLOCKED; |
cb3d8972 PB |
1726 | |
1727 | /* workqueue context doesn't hold uring_lock, grab it now */ | |
3b44b371 | 1728 | if (unlikely(needs_lock)) |
cb3d8972 | 1729 | mutex_lock(&ctx->uring_lock); |
def596e9 JA |
1730 | |
1731 | /* | |
1732 | * Track whether we have multiple files in our lists. This will impact | |
1733 | * how we do polling eventually, not spinning if we're on potentially | |
1734 | * different devices. | |
1735 | */ | |
5eef4e87 | 1736 | if (wq_list_empty(&ctx->iopoll_list)) { |
915b3dde HX |
1737 | ctx->poll_multi_queue = false; |
1738 | } else if (!ctx->poll_multi_queue) { | |
def596e9 JA |
1739 | struct io_kiocb *list_req; |
1740 | ||
5eef4e87 PB |
1741 | list_req = container_of(ctx->iopoll_list.first, struct io_kiocb, |
1742 | comp_list); | |
30da1b45 | 1743 | if (list_req->file != req->file) |
915b3dde | 1744 | ctx->poll_multi_queue = true; |
def596e9 JA |
1745 | } |
1746 | ||
1747 | /* | |
1748 | * For fast devices, IO may have already completed. If it has, add | |
1749 | * it to the front so we find it first. | |
1750 | */ | |
65a6543d | 1751 | if (READ_ONCE(req->iopoll_completed)) |
5eef4e87 | 1752 | wq_list_add_head(&req->comp_list, &ctx->iopoll_list); |
def596e9 | 1753 | else |
5eef4e87 | 1754 | wq_list_add_tail(&req->comp_list, &ctx->iopoll_list); |
bdcd3eab | 1755 | |
3b44b371 | 1756 | if (unlikely(needs_lock)) { |
cb3d8972 PB |
1757 | /* |
1758 | * If IORING_SETUP_SQPOLL is enabled, sqes are either handle | |
1759 | * in sq thread task context or in io worker task context. If | |
1760 | * current task context is sq thread, we don't need to check | |
1761 | * whether should wake up sq thread. | |
1762 | */ | |
1763 | if ((ctx->flags & IORING_SETUP_SQPOLL) && | |
1764 | wq_has_sleeper(&ctx->sq_data->wait)) | |
1765 | wake_up(&ctx->sq_data->wait); | |
1766 | ||
1767 | mutex_unlock(&ctx->uring_lock); | |
1768 | } | |
def596e9 JA |
1769 | } |
1770 | ||
a4ad4f74 | 1771 | unsigned int io_file_get_flags(struct file *file) |
88459b50 | 1772 | { |
88459b50 | 1773 | unsigned int res = 0; |
af197f50 | 1774 | |
53cfd5ce | 1775 | if (S_ISREG(file_inode(file)->i_mode)) |
8487f083 | 1776 | res |= REQ_F_ISREG; |
b9a6c945 | 1777 | if ((file->f_flags & O_NONBLOCK) || (file->f_mode & FMODE_NOWAIT)) |
8487f083 | 1778 | res |= REQ_F_SUPPORT_NOWAIT; |
88459b50 | 1779 | return res; |
2b188cc1 JA |
1780 | } |
1781 | ||
99f15d8d | 1782 | bool io_alloc_async_data(struct io_kiocb *req) |
3d9932a8 | 1783 | { |
f30bd4d0 BL |
1784 | WARN_ON_ONCE(!io_cold_defs[req->opcode].async_size); |
1785 | req->async_data = kmalloc(io_cold_defs[req->opcode].async_size, GFP_KERNEL); | |
d886e185 PB |
1786 | if (req->async_data) { |
1787 | req->flags |= REQ_F_ASYNC_DATA; | |
1788 | return false; | |
1789 | } | |
1790 | return true; | |
3d9932a8 XW |
1791 | } |
1792 | ||
f3b44f92 | 1793 | int io_req_prep_async(struct io_kiocb *req) |
f67676d1 | 1794 | { |
f30bd4d0 | 1795 | const struct io_cold_def *cdef = &io_cold_defs[req->opcode]; |
a7dd2782 | 1796 | const struct io_issue_def *def = &io_issue_defs[req->opcode]; |
0702e536 JA |
1797 | |
1798 | /* assign early for deferred execution for non-fixed file */ | |
54aa7f23 | 1799 | if (def->needs_file && !(req->flags & REQ_F_FIXED_FILE) && !req->file) |
0702e536 | 1800 | req->file = io_file_get_normal(req, req->cqe.fd); |
f30bd4d0 | 1801 | if (!cdef->prep_async) |
0702e536 JA |
1802 | return 0; |
1803 | if (WARN_ON_ONCE(req_has_async_data(req))) | |
1804 | return -EFAULT; | |
f30bd4d0 | 1805 | if (!def->manual_alloc) { |
59169439 PB |
1806 | if (io_alloc_async_data(req)) |
1807 | return -EAGAIN; | |
1808 | } | |
f30bd4d0 | 1809 | return cdef->prep_async(req); |
bfe76559 PB |
1810 | } |
1811 | ||
9cf7c104 PB |
1812 | static u32 io_get_sequence(struct io_kiocb *req) |
1813 | { | |
a3dbdf54 | 1814 | u32 seq = req->ctx->cached_sq_head; |
963c6abb | 1815 | struct io_kiocb *cur; |
9cf7c104 | 1816 | |
a3dbdf54 | 1817 | /* need original cached_sq_head, but it was increased for each req */ |
963c6abb | 1818 | io_for_each_link(cur, req) |
a3dbdf54 PB |
1819 | seq--; |
1820 | return seq; | |
9cf7c104 PB |
1821 | } |
1822 | ||
c072481d | 1823 | static __cold void io_drain_req(struct io_kiocb *req) |
e276ae34 | 1824 | __must_hold(&ctx->uring_lock) |
de0617e4 | 1825 | { |
a197f664 | 1826 | struct io_ring_ctx *ctx = req->ctx; |
27dc8338 | 1827 | struct io_defer_entry *de; |
f67676d1 | 1828 | int ret; |
e0eb71dc | 1829 | u32 seq = io_get_sequence(req); |
3c19966d | 1830 | |
9d858b21 | 1831 | /* Still need defer if there is pending req in defer list. */ |
e302f104 | 1832 | spin_lock(&ctx->completion_lock); |
5e371265 | 1833 | if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list)) { |
e302f104 | 1834 | spin_unlock(&ctx->completion_lock); |
e0eb71dc | 1835 | queue: |
10c66904 | 1836 | ctx->drain_active = false; |
e0eb71dc PB |
1837 | io_req_task_queue(req); |
1838 | return; | |
10c66904 | 1839 | } |
e302f104 | 1840 | spin_unlock(&ctx->completion_lock); |
9cf7c104 | 1841 | |
cbdcb435 | 1842 | io_prep_async_link(req); |
27dc8338 | 1843 | de = kmalloc(sizeof(*de), GFP_KERNEL); |
76cc33d7 | 1844 | if (!de) { |
1b48773f | 1845 | ret = -ENOMEM; |
ef5c600a DY |
1846 | io_req_defer_failed(req, ret); |
1847 | return; | |
76cc33d7 | 1848 | } |
2d28390a | 1849 | |
79ebeaee | 1850 | spin_lock(&ctx->completion_lock); |
9cf7c104 | 1851 | if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) { |
79ebeaee | 1852 | spin_unlock(&ctx->completion_lock); |
27dc8338 | 1853 | kfree(de); |
e0eb71dc | 1854 | goto queue; |
de0617e4 JA |
1855 | } |
1856 | ||
48863ffd | 1857 | trace_io_uring_defer(req); |
27dc8338 | 1858 | de->req = req; |
9cf7c104 | 1859 | de->seq = seq; |
27dc8338 | 1860 | list_add_tail(&de->list, &ctx->defer_list); |
79ebeaee | 1861 | spin_unlock(&ctx->completion_lock); |
de0617e4 JA |
1862 | } |
1863 | ||
f4992544 JA |
1864 | static bool io_assign_file(struct io_kiocb *req, const struct io_issue_def *def, |
1865 | unsigned int issue_flags) | |
6bf9c47a | 1866 | { |
f4992544 | 1867 | if (req->file || !def->needs_file) |
6bf9c47a JA |
1868 | return true; |
1869 | ||
1870 | if (req->flags & REQ_F_FIXED_FILE) | |
cef216fc | 1871 | req->file = io_file_get_fixed(req, req->cqe.fd, issue_flags); |
6bf9c47a | 1872 | else |
cef216fc | 1873 | req->file = io_file_get_normal(req, req->cqe.fd); |
6bf9c47a | 1874 | |
772f5e00 | 1875 | return !!req->file; |
6bf9c47a JA |
1876 | } |
1877 | ||
889fca73 | 1878 | static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) |
2b188cc1 | 1879 | { |
a7dd2782 | 1880 | const struct io_issue_def *def = &io_issue_defs[req->opcode]; |
5730b27e | 1881 | const struct cred *creds = NULL; |
d625c6ee | 1882 | int ret; |
2b188cc1 | 1883 | |
f4992544 | 1884 | if (unlikely(!io_assign_file(req, def, issue_flags))) |
70152140 JA |
1885 | return -EBADF; |
1886 | ||
6878b40e | 1887 | if (unlikely((req->flags & REQ_F_CREDS) && req->creds != current_cred())) |
c10d1f98 | 1888 | creds = override_creds(req->creds); |
5730b27e | 1889 | |
fcde59fe | 1890 | if (!def->audit_skip) |
5bd2182d PM |
1891 | audit_uring_entry(req->opcode); |
1892 | ||
0702e536 | 1893 | ret = def->issue(req, issue_flags); |
2b188cc1 | 1894 | |
fcde59fe | 1895 | if (!def->audit_skip) |
5bd2182d PM |
1896 | audit_uring_exit(!ret, ret); |
1897 | ||
5730b27e JA |
1898 | if (creds) |
1899 | revert_creds(creds); | |
97b388d7 | 1900 | |
75d7b3ae PB |
1901 | if (ret == IOU_OK) { |
1902 | if (issue_flags & IO_URING_F_COMPLETE_DEFER) | |
9da070b1 | 1903 | io_req_complete_defer(req); |
75d7b3ae | 1904 | else |
1bec951c | 1905 | io_req_complete_post(req, issue_flags); |
97b388d7 | 1906 | |
9b43ef3d PB |
1907 | return 0; |
1908 | } | |
def596e9 | 1909 | |
e0b23d99 PB |
1910 | if (ret == IOU_ISSUE_SKIP_COMPLETE) { |
1911 | ret = 0; | |
1912 | io_arm_ltimeout(req); | |
def596e9 | 1913 | |
e0b23d99 PB |
1914 | /* If the op doesn't have a file, we're not polling for it */ |
1915 | if ((req->ctx->flags & IORING_SETUP_IOPOLL) && def->iopoll_queue) | |
1916 | io_iopoll_req_issued(req, issue_flags); | |
1917 | } | |
1918 | return ret; | |
2b188cc1 JA |
1919 | } |
1920 | ||
a282967c | 1921 | int io_poll_issue(struct io_kiocb *req, struct io_tw_state *ts) |
329061d3 | 1922 | { |
a282967c | 1923 | io_tw_lock(req->ctx, ts); |
9a692451 DY |
1924 | return io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_MULTISHOT| |
1925 | IO_URING_F_COMPLETE_DEFER); | |
329061d3 JA |
1926 | } |
1927 | ||
c9f06aa7 | 1928 | struct io_wq_work *io_wq_free_work(struct io_wq_work *work) |
ebc11b6c PB |
1929 | { |
1930 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
247f97a5 | 1931 | struct io_kiocb *nxt = NULL; |
ebc11b6c | 1932 | |
247f97a5 PB |
1933 | if (req_ref_put_and_test(req)) { |
1934 | if (req->flags & IO_REQ_LINK_FLAGS) | |
1935 | nxt = io_req_find_next(req); | |
1936 | io_free_req(req); | |
1937 | } | |
1938 | return nxt ? &nxt->work : NULL; | |
ebc11b6c PB |
1939 | } |
1940 | ||
c9f06aa7 | 1941 | void io_wq_submit_work(struct io_wq_work *work) |
2b188cc1 JA |
1942 | { |
1943 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
a7dd2782 | 1944 | const struct io_issue_def *def = &io_issue_defs[req->opcode]; |
e6aeb272 | 1945 | unsigned int issue_flags = IO_URING_F_UNLOCKED | IO_URING_F_IOWQ; |
d01905db | 1946 | bool needs_poll = false; |
6bf9c47a | 1947 | int ret = 0, err = -ECANCELED; |
2b188cc1 | 1948 | |
23a6c9ac | 1949 | /* one will be dropped by ->io_wq_free_work() after returning to io-wq */ |
48dcd38d PB |
1950 | if (!(req->flags & REQ_F_REFCOUNT)) |
1951 | __io_req_set_refcount(req, 2); | |
1952 | else | |
1953 | req_ref_get(req); | |
5d5901a3 | 1954 | |
cb2d344c | 1955 | io_arm_ltimeout(req); |
6bf9c47a | 1956 | |
dadebc35 | 1957 | /* either cancelled or io-wq is dying, so don't touch tctx->iowq */ |
d01905db | 1958 | if (work->flags & IO_WQ_WORK_CANCEL) { |
0f8da75b | 1959 | fail: |
6bf9c47a | 1960 | io_req_task_queue_fail(req, err); |
d01905db PB |
1961 | return; |
1962 | } | |
f4992544 | 1963 | if (!io_assign_file(req, def, issue_flags)) { |
0f8da75b PB |
1964 | err = -EBADF; |
1965 | work->flags |= IO_WQ_WORK_CANCEL; | |
1966 | goto fail; | |
1967 | } | |
31b51510 | 1968 | |
d01905db | 1969 | if (req->flags & REQ_F_FORCE_ASYNC) { |
afb7f56f PB |
1970 | bool opcode_poll = def->pollin || def->pollout; |
1971 | ||
1972 | if (opcode_poll && file_can_poll(req->file)) { | |
1973 | needs_poll = true; | |
d01905db | 1974 | issue_flags |= IO_URING_F_NONBLOCK; |
afb7f56f | 1975 | } |
561fb04a | 1976 | } |
31b51510 | 1977 | |
d01905db PB |
1978 | do { |
1979 | ret = io_issue_sqe(req, issue_flags); | |
1980 | if (ret != -EAGAIN) | |
1981 | break; | |
a9be2022 JA |
1982 | |
1983 | /* | |
1984 | * If REQ_F_NOWAIT is set, then don't wait or retry with | |
1985 | * poll. -EAGAIN is final for that case. | |
1986 | */ | |
1987 | if (req->flags & REQ_F_NOWAIT) | |
1988 | break; | |
1989 | ||
d01905db PB |
1990 | /* |
1991 | * We can get EAGAIN for iopolled IO even though we're | |
1992 | * forcing a sync submission from here, since we can't | |
1993 | * wait for request slots on the block side. | |
1994 | */ | |
1995 | if (!needs_poll) { | |
e0deb6a0 PB |
1996 | if (!(req->ctx->flags & IORING_SETUP_IOPOLL)) |
1997 | break; | |
45500dc4 PB |
1998 | if (io_wq_worker_stopped()) |
1999 | break; | |
d01905db PB |
2000 | cond_resched(); |
2001 | continue; | |
90fa0288 HX |
2002 | } |
2003 | ||
4d9237e3 | 2004 | if (io_arm_poll_handler(req, issue_flags) == IO_APOLL_OK) |
d01905db PB |
2005 | return; |
2006 | /* aborted or ready, in either case retry blocking */ | |
2007 | needs_poll = false; | |
2008 | issue_flags &= ~IO_URING_F_NONBLOCK; | |
2009 | } while (1); | |
31b51510 | 2010 | |
a3df7698 | 2011 | /* avoid locking problems by failing it from a clean context */ |
97b388d7 | 2012 | if (ret < 0) |
a3df7698 | 2013 | io_req_task_queue_fail(req, ret); |
2b188cc1 JA |
2014 | } |
2015 | ||
531113bb JA |
2016 | inline struct file *io_file_get_fixed(struct io_kiocb *req, int fd, |
2017 | unsigned int issue_flags) | |
09bb8394 | 2018 | { |
5106dd6e | 2019 | struct io_ring_ctx *ctx = req->ctx; |
4bfb0c9a | 2020 | struct io_fixed_file *slot; |
5106dd6e | 2021 | struct file *file = NULL; |
09bb8394 | 2022 | |
93f052cb | 2023 | io_ring_submit_lock(ctx, issue_flags); |
5106dd6e | 2024 | |
ac177053 | 2025 | if (unlikely((unsigned int)fd >= ctx->nr_user_files)) |
5106dd6e | 2026 | goto out; |
ac177053 | 2027 | fd = array_index_nospec(fd, ctx->nr_user_files); |
4bfb0c9a | 2028 | slot = io_fixed_file_slot(&ctx->file_table, fd); |
3f302388 JA |
2029 | if (!req->rsrc_node) |
2030 | __io_req_set_rsrc_node(req, ctx); | |
4bfb0c9a | 2031 | req->flags |= io_slot_flags(slot); |
3f302388 | 2032 | file = io_slot_file(slot); |
5106dd6e | 2033 | out: |
93f052cb | 2034 | io_ring_submit_unlock(ctx, issue_flags); |
ac177053 PB |
2035 | return file; |
2036 | } | |
d44f554e | 2037 | |
531113bb | 2038 | struct file *io_file_get_normal(struct io_kiocb *req, int fd) |
ac177053 | 2039 | { |
62906e89 | 2040 | struct file *file = fget(fd); |
ac177053 | 2041 | |
48863ffd | 2042 | trace_io_uring_file_get(req, fd); |
09bb8394 | 2043 | |
ac177053 | 2044 | /* we don't allow fixed io_uring files */ |
e5550a14 | 2045 | if (file && io_is_uring_fops(file)) |
9cae36a0 | 2046 | io_req_track_inflight(req); |
8371adf5 | 2047 | return file; |
09bb8394 JA |
2048 | } |
2049 | ||
7bfa9bad | 2050 | static void io_queue_async(struct io_kiocb *req, int ret) |
d475a9a6 PB |
2051 | __must_hold(&req->ctx->uring_lock) |
2052 | { | |
7bfa9bad PB |
2053 | struct io_kiocb *linked_timeout; |
2054 | ||
2055 | if (ret != -EAGAIN || (req->flags & REQ_F_NOWAIT)) { | |
973fc83f | 2056 | io_req_defer_failed(req, ret); |
7bfa9bad PB |
2057 | return; |
2058 | } | |
2059 | ||
2060 | linked_timeout = io_prep_linked_timeout(req); | |
d475a9a6 | 2061 | |
4d9237e3 | 2062 | switch (io_arm_poll_handler(req, 0)) { |
d475a9a6 | 2063 | case IO_APOLL_READY: |
336d28a8 | 2064 | io_kbuf_recycle(req, 0); |
d475a9a6 PB |
2065 | io_req_task_queue(req); |
2066 | break; | |
2067 | case IO_APOLL_ABORTED: | |
6436c770 | 2068 | io_kbuf_recycle(req, 0); |
77955efb | 2069 | io_queue_iowq(req, NULL); |
d475a9a6 | 2070 | break; |
b1c62645 | 2071 | case IO_APOLL_OK: |
b1c62645 | 2072 | break; |
d475a9a6 PB |
2073 | } |
2074 | ||
2075 | if (linked_timeout) | |
2076 | io_queue_linked_timeout(linked_timeout); | |
2077 | } | |
2078 | ||
cbc2e203 | 2079 | static inline void io_queue_sqe(struct io_kiocb *req) |
282cdc86 | 2080 | __must_hold(&req->ctx->uring_lock) |
2b188cc1 | 2081 | { |
e0c5c576 | 2082 | int ret; |
2b188cc1 | 2083 | |
c5eef2b9 | 2084 | ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER); |
193155c8 | 2085 | |
491381ce JA |
2086 | /* |
2087 | * We async punt it if the file wasn't marked NOWAIT, or if the file | |
2088 | * doesn't support non-blocking read/write attempts | |
2089 | */ | |
e0b23d99 | 2090 | if (unlikely(ret)) |
7bfa9bad | 2091 | io_queue_async(req, ret); |
2b188cc1 JA |
2092 | } |
2093 | ||
4652fe3f | 2094 | static void io_queue_sqe_fallback(struct io_kiocb *req) |
282cdc86 | 2095 | __must_hold(&req->ctx->uring_lock) |
4fe2c963 | 2096 | { |
17b147f6 PB |
2097 | if (unlikely(req->flags & REQ_F_FAIL)) { |
2098 | /* | |
2099 | * We don't submit, fail them all, for that replace hardlinks | |
2100 | * with normal links. Extra REQ_F_LINK is tolerated. | |
2101 | */ | |
2102 | req->flags &= ~REQ_F_HARDLINK; | |
2103 | req->flags |= REQ_F_LINK; | |
973fc83f | 2104 | io_req_defer_failed(req, req->cqe.res); |
76cc33d7 PB |
2105 | } else { |
2106 | int ret = io_req_prep_async(req); | |
2107 | ||
ef5c600a | 2108 | if (unlikely(ret)) { |
973fc83f | 2109 | io_req_defer_failed(req, ret); |
ef5c600a DY |
2110 | return; |
2111 | } | |
2112 | ||
2113 | if (unlikely(req->ctx->drain_active)) | |
2114 | io_drain_req(req); | |
76cc33d7 | 2115 | else |
77955efb | 2116 | io_queue_iowq(req, NULL); |
ce35a47a | 2117 | } |
4fe2c963 JL |
2118 | } |
2119 | ||
b16fed66 PB |
2120 | /* |
2121 | * Check SQE restrictions (opcode and flags). | |
2122 | * | |
2123 | * Returns 'true' if SQE is allowed, 'false' otherwise. | |
2124 | */ | |
2125 | static inline bool io_check_restriction(struct io_ring_ctx *ctx, | |
2126 | struct io_kiocb *req, | |
2127 | unsigned int sqe_flags) | |
4fe2c963 | 2128 | { |
b16fed66 PB |
2129 | if (!test_bit(req->opcode, ctx->restrictions.sqe_op)) |
2130 | return false; | |
2131 | ||
2132 | if ((sqe_flags & ctx->restrictions.sqe_flags_required) != | |
2133 | ctx->restrictions.sqe_flags_required) | |
2134 | return false; | |
2135 | ||
2136 | if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed | | |
2137 | ctx->restrictions.sqe_flags_required)) | |
2138 | return false; | |
2139 | ||
2140 | return true; | |
4fe2c963 JL |
2141 | } |
2142 | ||
22b2ca31 PB |
2143 | static void io_init_req_drain(struct io_kiocb *req) |
2144 | { | |
2145 | struct io_ring_ctx *ctx = req->ctx; | |
2146 | struct io_kiocb *head = ctx->submit_state.link.head; | |
2147 | ||
2148 | ctx->drain_active = true; | |
2149 | if (head) { | |
2150 | /* | |
2151 | * If we need to drain a request in the middle of a link, drain | |
2152 | * the head request and the next request/link after the current | |
2153 | * link. Considering sequential execution of links, | |
b6c7db32 | 2154 | * REQ_F_IO_DRAIN will be maintained for every request of our |
22b2ca31 PB |
2155 | * link. |
2156 | */ | |
b6c7db32 | 2157 | head->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC; |
22b2ca31 PB |
2158 | ctx->drain_next = true; |
2159 | } | |
2160 | } | |
2161 | ||
b16fed66 PB |
2162 | static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, |
2163 | const struct io_uring_sqe *sqe) | |
282cdc86 | 2164 | __must_hold(&ctx->uring_lock) |
b16fed66 | 2165 | { |
a7dd2782 | 2166 | const struct io_issue_def *def; |
b16fed66 | 2167 | unsigned int sqe_flags; |
fc0ae024 | 2168 | int personality; |
4a04d1d1 | 2169 | u8 opcode; |
b16fed66 | 2170 | |
864ea921 | 2171 | /* req is partially pre-initialised, see io_preinit_req() */ |
4a04d1d1 | 2172 | req->opcode = opcode = READ_ONCE(sqe->opcode); |
b16fed66 PB |
2173 | /* same numerical values with corresponding REQ_F_*, safe to copy */ |
2174 | req->flags = sqe_flags = READ_ONCE(sqe->flags); | |
cef216fc | 2175 | req->cqe.user_data = READ_ONCE(sqe->user_data); |
b16fed66 | 2176 | req->file = NULL; |
c1bdf8ed | 2177 | req->rsrc_node = NULL; |
b16fed66 | 2178 | req->task = current; |
b16fed66 | 2179 | |
4a04d1d1 PB |
2180 | if (unlikely(opcode >= IORING_OP_LAST)) { |
2181 | req->opcode = 0; | |
b16fed66 | 2182 | return -EINVAL; |
4a04d1d1 | 2183 | } |
a7dd2782 | 2184 | def = &io_issue_defs[opcode]; |
68fe256a PB |
2185 | if (unlikely(sqe_flags & ~SQE_COMMON_FLAGS)) { |
2186 | /* enforce forwards compatibility on users */ | |
2187 | if (sqe_flags & ~SQE_VALID_FLAGS) | |
2188 | return -EINVAL; | |
4e906702 | 2189 | if (sqe_flags & IOSQE_BUFFER_SELECT) { |
fcde59fe | 2190 | if (!def->buffer_select) |
4e906702 JA |
2191 | return -EOPNOTSUPP; |
2192 | req->buf_index = READ_ONCE(sqe->buf_group); | |
2193 | } | |
5562a8d7 PB |
2194 | if (sqe_flags & IOSQE_CQE_SKIP_SUCCESS) |
2195 | ctx->drain_disabled = true; | |
2196 | if (sqe_flags & IOSQE_IO_DRAIN) { | |
2197 | if (ctx->drain_disabled) | |
2198 | return -EOPNOTSUPP; | |
22b2ca31 | 2199 | io_init_req_drain(req); |
5562a8d7 | 2200 | } |
2a56a9bd PB |
2201 | } |
2202 | if (unlikely(ctx->restricted || ctx->drain_active || ctx->drain_next)) { | |
2203 | if (ctx->restricted && !io_check_restriction(ctx, req, sqe_flags)) | |
2204 | return -EACCES; | |
2205 | /* knock it to the slow queue path, will be drained there */ | |
2206 | if (ctx->drain_active) | |
2207 | req->flags |= REQ_F_FORCE_ASYNC; | |
2208 | /* if there is no link, we're at "next" request and need to drain */ | |
2209 | if (unlikely(ctx->drain_next) && !ctx->submit_state.link.head) { | |
2210 | ctx->drain_next = false; | |
2211 | ctx->drain_active = true; | |
b6c7db32 | 2212 | req->flags |= REQ_F_IO_DRAIN | REQ_F_FORCE_ASYNC; |
2a56a9bd | 2213 | } |
68fe256a | 2214 | } |
b16fed66 | 2215 | |
fcde59fe | 2216 | if (!def->ioprio && sqe->ioprio) |
73911426 | 2217 | return -EINVAL; |
fcde59fe | 2218 | if (!def->iopoll && (ctx->flags & IORING_SETUP_IOPOLL)) |
73911426 JA |
2219 | return -EINVAL; |
2220 | ||
fcde59fe | 2221 | if (def->needs_file) { |
6d63416d PB |
2222 | struct io_submit_state *state = &ctx->submit_state; |
2223 | ||
cef216fc | 2224 | req->cqe.fd = READ_ONCE(sqe->fd); |
6bf9c47a | 2225 | |
6d63416d PB |
2226 | /* |
2227 | * Plug now if we have more than 2 IO left after this, and the | |
2228 | * target is potentially a read/write to block based storage. | |
2229 | */ | |
fcde59fe | 2230 | if (state->need_plug && def->plug) { |
6d63416d PB |
2231 | state->plug_started = true; |
2232 | state->need_plug = false; | |
5ca7a8b3 | 2233 | blk_start_plug_nr_ios(&state->plug, state->submit_nr); |
6d63416d | 2234 | } |
b16fed66 | 2235 | } |
863e0560 | 2236 | |
003e8dcc JA |
2237 | personality = READ_ONCE(sqe->personality); |
2238 | if (personality) { | |
cdab10bf LT |
2239 | int ret; |
2240 | ||
c10d1f98 PB |
2241 | req->creds = xa_load(&ctx->personalities, personality); |
2242 | if (!req->creds) | |
003e8dcc | 2243 | return -EINVAL; |
c10d1f98 | 2244 | get_cred(req->creds); |
cdc1404a PM |
2245 | ret = security_uring_override_creds(req->creds); |
2246 | if (ret) { | |
2247 | put_cred(req->creds); | |
2248 | return ret; | |
2249 | } | |
b8e64b53 | 2250 | req->flags |= REQ_F_CREDS; |
003e8dcc | 2251 | } |
b16fed66 | 2252 | |
0702e536 | 2253 | return def->prep(req, sqe); |
b16fed66 PB |
2254 | } |
2255 | ||
df3becde PB |
2256 | static __cold int io_submit_fail_init(const struct io_uring_sqe *sqe, |
2257 | struct io_kiocb *req, int ret) | |
2258 | { | |
2259 | struct io_ring_ctx *ctx = req->ctx; | |
2260 | struct io_submit_link *link = &ctx->submit_state.link; | |
2261 | struct io_kiocb *head = link->head; | |
2262 | ||
48863ffd | 2263 | trace_io_uring_req_failed(sqe, req, ret); |
df3becde PB |
2264 | |
2265 | /* | |
2266 | * Avoid breaking links in the middle as it renders links with SQPOLL | |
2267 | * unusable. Instead of failing eagerly, continue assembling the link if | |
2268 | * applicable and mark the head with REQ_F_FAIL. The link flushing code | |
2269 | * should find the flag and handle the rest. | |
2270 | */ | |
2271 | req_fail_link_node(req, ret); | |
2272 | if (head && !(head->flags & REQ_F_FAIL)) | |
2273 | req_fail_link_node(head, -ECANCELED); | |
2274 | ||
2275 | if (!(req->flags & IO_REQ_LINK_FLAGS)) { | |
2276 | if (head) { | |
2277 | link->last->link = req; | |
2278 | link->head = NULL; | |
2279 | req = head; | |
2280 | } | |
2281 | io_queue_sqe_fallback(req); | |
2282 | return ret; | |
2283 | } | |
2284 | ||
2285 | if (head) | |
2286 | link->last->link = req; | |
2287 | else | |
2288 | link->head = req; | |
2289 | link->last = req; | |
2290 | return 0; | |
2291 | } | |
2292 | ||
2293 | static inline int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, | |
a1ab7b35 | 2294 | const struct io_uring_sqe *sqe) |
282cdc86 | 2295 | __must_hold(&ctx->uring_lock) |
9e645e11 | 2296 | { |
a1ab7b35 | 2297 | struct io_submit_link *link = &ctx->submit_state.link; |
ef4ff581 | 2298 | int ret; |
9e645e11 | 2299 | |
a6b8cadc | 2300 | ret = io_init_req(ctx, req, sqe); |
df3becde PB |
2301 | if (unlikely(ret)) |
2302 | return io_submit_fail_init(sqe, req, ret); | |
441b8a78 | 2303 | |
2ad57931 | 2304 | trace_io_uring_submit_req(req); |
a6b8cadc | 2305 | |
9e645e11 JA |
2306 | /* |
2307 | * If we already have a head request, queue this one for async | |
2308 | * submittal once the head completes. If we don't have a head but | |
2309 | * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be | |
2310 | * submitted sync once the chain is complete. If none of those | |
2311 | * conditions are true (normal request), then just queue it. | |
2312 | */ | |
924a07e4 | 2313 | if (unlikely(link->head)) { |
df3becde PB |
2314 | ret = io_req_prep_async(req); |
2315 | if (unlikely(ret)) | |
2316 | return io_submit_fail_init(sqe, req, ret); | |
2317 | ||
48863ffd | 2318 | trace_io_uring_link(req, link->head); |
f2f87370 | 2319 | link->last->link = req; |
863e0560 | 2320 | link->last = req; |
32fe525b | 2321 | |
da1a08c5 | 2322 | if (req->flags & IO_REQ_LINK_FLAGS) |
f15a3431 | 2323 | return 0; |
df3becde PB |
2324 | /* last request of the link, flush it */ |
2325 | req = link->head; | |
f15a3431 | 2326 | link->head = NULL; |
924a07e4 PB |
2327 | if (req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL)) |
2328 | goto fallback; | |
2329 | ||
2330 | } else if (unlikely(req->flags & (IO_REQ_LINK_FLAGS | | |
2331 | REQ_F_FORCE_ASYNC | REQ_F_FAIL))) { | |
2332 | if (req->flags & IO_REQ_LINK_FLAGS) { | |
2333 | link->head = req; | |
2334 | link->last = req; | |
2335 | } else { | |
2336 | fallback: | |
2337 | io_queue_sqe_fallback(req); | |
2338 | } | |
f15a3431 | 2339 | return 0; |
9e645e11 | 2340 | } |
2e6e1fde | 2341 | |
f15a3431 | 2342 | io_queue_sqe(req); |
1d4240cc | 2343 | return 0; |
9e645e11 JA |
2344 | } |
2345 | ||
9a56a232 JA |
2346 | /* |
2347 | * Batched submission is done, ensure local IO is flushed out. | |
2348 | */ | |
553deffd | 2349 | static void io_submit_state_end(struct io_ring_ctx *ctx) |
9a56a232 | 2350 | { |
553deffd PB |
2351 | struct io_submit_state *state = &ctx->submit_state; |
2352 | ||
e126391c PB |
2353 | if (unlikely(state->link.head)) |
2354 | io_queue_sqe_fallback(state->link.head); | |
553deffd | 2355 | /* flush only after queuing links as they can generate completions */ |
c450178d | 2356 | io_submit_flush_completions(ctx); |
27926b68 JA |
2357 | if (state->plug_started) |
2358 | blk_finish_plug(&state->plug); | |
9a56a232 JA |
2359 | } |
2360 | ||
2361 | /* | |
2362 | * Start submission side cache. | |
2363 | */ | |
2364 | static void io_submit_state_start(struct io_submit_state *state, | |
ba88ff11 | 2365 | unsigned int max_ios) |
9a56a232 | 2366 | { |
27926b68 | 2367 | state->plug_started = false; |
4b628aeb | 2368 | state->need_plug = max_ios > 2; |
5ca7a8b3 | 2369 | state->submit_nr = max_ios; |
a1ab7b35 PB |
2370 | /* set only head, no need to init link_last in advance */ |
2371 | state->link.head = NULL; | |
9a56a232 JA |
2372 | } |
2373 | ||
2b188cc1 JA |
2374 | static void io_commit_sqring(struct io_ring_ctx *ctx) |
2375 | { | |
75b28aff | 2376 | struct io_rings *rings = ctx->rings; |
2b188cc1 | 2377 | |
caf582c6 PB |
2378 | /* |
2379 | * Ensure any loads from the SQEs are done at this point, | |
2380 | * since once we write the new head, the application could | |
2381 | * write new data to them. | |
2382 | */ | |
2383 | smp_store_release(&rings->sq.head, ctx->cached_sq_head); | |
2b188cc1 JA |
2384 | } |
2385 | ||
2b188cc1 | 2386 | /* |
dd9ae8a0 | 2387 | * Fetch an sqe, if one is available. Note this returns a pointer to memory |
2b188cc1 JA |
2388 | * that is mapped by userspace. This means that care needs to be taken to |
2389 | * ensure that reads are stable, as we cannot rely on userspace always | |
2390 | * being a good citizen. If members of the sqe are validated and then later | |
2391 | * used, it's important that those reads are done through READ_ONCE() to | |
2392 | * prevent a re-load down the line. | |
2393 | */ | |
b5083dfa | 2394 | static bool io_get_sqe(struct io_ring_ctx *ctx, const struct io_uring_sqe **sqe) |
2b188cc1 | 2395 | { |
2af89abd PB |
2396 | unsigned mask = ctx->sq_entries - 1; |
2397 | unsigned head = ctx->cached_sq_head++ & mask; | |
2398 | ||
2399 | if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) { | |
2400 | head = READ_ONCE(ctx->sq_array[head]); | |
2401 | if (unlikely(head >= ctx->sq_entries)) { | |
2402 | /* drop invalid entries */ | |
2403 | spin_lock(&ctx->completion_lock); | |
2404 | ctx->cq_extra--; | |
2405 | spin_unlock(&ctx->completion_lock); | |
2406 | WRITE_ONCE(ctx->rings->sq_dropped, | |
2407 | READ_ONCE(ctx->rings->sq_dropped) + 1); | |
2408 | return false; | |
2409 | } | |
2410 | } | |
2b188cc1 JA |
2411 | |
2412 | /* | |
2413 | * The cached sq head (or cq tail) serves two purposes: | |
2414 | * | |
2415 | * 1) allows us to batch the cost of updating the user visible | |
2416 | * head updates. | |
2417 | * 2) allows the kernel side to track the head on its own, even | |
2418 | * though the application is the one updating it. | |
2419 | */ | |
2b188cc1 | 2420 | |
2af89abd PB |
2421 | /* double index for 128-byte SQEs, twice as long */ |
2422 | if (ctx->flags & IORING_SETUP_SQE128) | |
2423 | head <<= 1; | |
2424 | *sqe = &ctx->sq_sqes[head]; | |
2425 | return true; | |
709b302f PB |
2426 | } |
2427 | ||
17437f31 | 2428 | int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr) |
282cdc86 | 2429 | __must_hold(&ctx->uring_lock) |
6c271ce2 | 2430 | { |
69629809 | 2431 | unsigned int entries = io_sqring_entries(ctx); |
8e6971a8 PB |
2432 | unsigned int left; |
2433 | int ret; | |
6c271ce2 | 2434 | |
51d48dab | 2435 | if (unlikely(!entries)) |
69629809 | 2436 | return 0; |
ee7d46d9 | 2437 | /* make sure SQ entry isn't read before tail */ |
e3ef728f | 2438 | ret = left = min(nr, entries); |
8e6971a8 PB |
2439 | io_get_task_refs(left); |
2440 | io_submit_state_start(&ctx->submit_state, left); | |
6c271ce2 | 2441 | |
69629809 | 2442 | do { |
3529d8c2 | 2443 | const struct io_uring_sqe *sqe; |
196be95c | 2444 | struct io_kiocb *req; |
fb5ccc98 | 2445 | |
c8576f3e | 2446 | if (unlikely(!io_alloc_req(ctx, &req))) |
fb5ccc98 | 2447 | break; |
b5083dfa | 2448 | if (unlikely(!io_get_sqe(ctx, &sqe))) { |
fa05457a | 2449 | io_req_add_to_cache(req, ctx); |
4fccfcbb PB |
2450 | break; |
2451 | } | |
6c271ce2 | 2452 | |
1cd15904 PB |
2453 | /* |
2454 | * Continue submitting even for sqe failure if the | |
2455 | * ring was setup with IORING_SETUP_SUBMIT_ALL | |
2456 | */ | |
2457 | if (unlikely(io_submit_sqe(ctx, req, sqe)) && | |
2458 | !(ctx->flags & IORING_SETUP_SUBMIT_ALL)) { | |
2459 | left--; | |
2460 | break; | |
bcbb7bf6 | 2461 | } |
1cd15904 | 2462 | } while (--left); |
9466f437 | 2463 | |
8e6971a8 PB |
2464 | if (unlikely(left)) { |
2465 | ret -= left; | |
2466 | /* try again if it submitted nothing and can't allocate a req */ | |
2467 | if (!ret && io_req_cache_empty(ctx)) | |
2468 | ret = -EAGAIN; | |
2469 | current->io_uring->cached_refs += left; | |
9466f437 | 2470 | } |
6c271ce2 | 2471 | |
553deffd | 2472 | io_submit_state_end(ctx); |
ae9428ca PB |
2473 | /* Commit SQ ring head once we've consumed and submitted all SQEs */ |
2474 | io_commit_sqring(ctx); | |
8e6971a8 | 2475 | return ret; |
6c271ce2 JA |
2476 | } |
2477 | ||
bda52162 JA |
2478 | struct io_wait_queue { |
2479 | struct wait_queue_entry wq; | |
2480 | struct io_ring_ctx *ctx; | |
5fd46178 | 2481 | unsigned cq_tail; |
bda52162 | 2482 | unsigned nr_timeouts; |
d33a39e5 | 2483 | ktime_t timeout; |
bda52162 JA |
2484 | }; |
2485 | ||
b4c98d59 DY |
2486 | static inline bool io_has_work(struct io_ring_ctx *ctx) |
2487 | { | |
c0e0d6ba | 2488 | return test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq) || |
490c00eb | 2489 | !llist_empty(&ctx->work_llist); |
b4c98d59 DY |
2490 | } |
2491 | ||
6c503150 | 2492 | static inline bool io_should_wake(struct io_wait_queue *iowq) |
bda52162 JA |
2493 | { |
2494 | struct io_ring_ctx *ctx = iowq->ctx; | |
0fc8c2ac | 2495 | int dist = READ_ONCE(ctx->rings->cq.tail) - (int) iowq->cq_tail; |
bda52162 JA |
2496 | |
2497 | /* | |
d195a66e | 2498 | * Wake up if we have enough events, or if a timeout occurred since we |
bda52162 JA |
2499 | * started waiting. For timeouts, we always want to return to userspace, |
2500 | * regardless of event count. | |
2501 | */ | |
5fd46178 | 2502 | return dist >= 0 || atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts; |
bda52162 JA |
2503 | } |
2504 | ||
2505 | static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode, | |
2506 | int wake_flags, void *key) | |
2507 | { | |
bd550173 | 2508 | struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, wq); |
bda52162 | 2509 | |
6c503150 PB |
2510 | /* |
2511 | * Cannot safely flush overflowed CQEs from here, ensure we wake up | |
2512 | * the task, and the next invocation will do it. | |
2513 | */ | |
bd550173 | 2514 | if (io_should_wake(iowq) || io_has_work(iowq->ctx)) |
6c503150 PB |
2515 | return autoremove_wake_function(curr, mode, wake_flags, key); |
2516 | return -1; | |
bda52162 JA |
2517 | } |
2518 | ||
c0e0d6ba | 2519 | int io_run_task_work_sig(struct io_ring_ctx *ctx) |
af9c1a44 | 2520 | { |
1414d629 | 2521 | if (!llist_empty(&ctx->work_llist)) { |
2f413956 | 2522 | __set_current_state(TASK_RUNNING); |
1414d629 | 2523 | if (io_run_local_work(ctx) > 0) |
d246c759 | 2524 | return 0; |
1414d629 PB |
2525 | } |
2526 | if (io_run_task_work() > 0) | |
d246c759 | 2527 | return 0; |
c5020bc8 OL |
2528 | if (task_sigpending(current)) |
2529 | return -EINTR; | |
2530 | return 0; | |
af9c1a44 JA |
2531 | } |
2532 | ||
7b72d661 JA |
2533 | static bool current_pending_io(void) |
2534 | { | |
2535 | struct io_uring_task *tctx = current->io_uring; | |
2536 | ||
2537 | if (!tctx) | |
2538 | return false; | |
2539 | return percpu_counter_read_positive(&tctx->inflight); | |
2540 | } | |
2541 | ||
eeb60b9a PB |
2542 | /* when returns >0, the caller should retry */ |
2543 | static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx, | |
d33a39e5 | 2544 | struct io_wait_queue *iowq) |
eeb60b9a | 2545 | { |
7b72d661 | 2546 | int io_wait, ret; |
8a796565 | 2547 | |
3fcf19d5 PB |
2548 | if (unlikely(READ_ONCE(ctx->check_cq))) |
2549 | return 1; | |
846072f1 PB |
2550 | if (unlikely(!llist_empty(&ctx->work_llist))) |
2551 | return 1; | |
2552 | if (unlikely(test_thread_flag(TIF_NOTIFY_SIGNAL))) | |
2553 | return 1; | |
2554 | if (unlikely(task_sigpending(current))) | |
2555 | return -EINTR; | |
2556 | if (unlikely(io_should_wake(iowq))) | |
2557 | return 0; | |
8a796565 AF |
2558 | |
2559 | /* | |
7b72d661 JA |
2560 | * Mark us as being in io_wait if we have pending requests, so cpufreq |
2561 | * can take into account that the task is waiting for IO - turns out | |
2562 | * to be important for low QD IO. | |
8a796565 | 2563 | */ |
7b72d661 JA |
2564 | io_wait = current->in_iowait; |
2565 | if (current_pending_io()) | |
2566 | current->in_iowait = 1; | |
8a796565 | 2567 | ret = 0; |
d33a39e5 | 2568 | if (iowq->timeout == KTIME_MAX) |
46ae7eef | 2569 | schedule(); |
d33a39e5 | 2570 | else if (!schedule_hrtimeout(&iowq->timeout, HRTIMER_MODE_ABS)) |
8a796565 | 2571 | ret = -ETIME; |
7b72d661 | 2572 | current->in_iowait = io_wait; |
8a796565 | 2573 | return ret; |
eeb60b9a PB |
2574 | } |
2575 | ||
2b188cc1 JA |
2576 | /* |
2577 | * Wait until events become available, if we don't already have some. The | |
2578 | * application must reap them itself, as they reside on the shared cq ring. | |
2579 | */ | |
2580 | static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, | |
c73ebb68 HX |
2581 | const sigset_t __user *sig, size_t sigsz, |
2582 | struct __kernel_timespec __user *uts) | |
2b188cc1 | 2583 | { |
90291099 | 2584 | struct io_wait_queue iowq; |
75b28aff | 2585 | struct io_rings *rings = ctx->rings; |
c1d5a224 | 2586 | int ret; |
2b188cc1 | 2587 | |
76de6749 PB |
2588 | if (!io_allowed_run_tw(ctx)) |
2589 | return -EEXIST; | |
140102ae PB |
2590 | if (!llist_empty(&ctx->work_llist)) |
2591 | io_run_local_work(ctx); | |
f36ba6cf PB |
2592 | io_run_task_work(); |
2593 | io_cqring_overflow_flush(ctx); | |
2594 | /* if user messes with these they will just get an early return */ | |
2595 | if (__io_cqring_events_user(ctx) >= min_events) | |
2596 | return 0; | |
2b188cc1 JA |
2597 | |
2598 | if (sig) { | |
9e75ad5d AB |
2599 | #ifdef CONFIG_COMPAT |
2600 | if (in_compat_syscall()) | |
2601 | ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig, | |
b772434b | 2602 | sigsz); |
9e75ad5d AB |
2603 | else |
2604 | #endif | |
b772434b | 2605 | ret = set_user_sigmask(sig, sigsz); |
9e75ad5d | 2606 | |
2b188cc1 JA |
2607 | if (ret) |
2608 | return ret; | |
2609 | } | |
2610 | ||
90291099 PB |
2611 | init_waitqueue_func_entry(&iowq.wq, io_wake_function); |
2612 | iowq.wq.private = current; | |
2613 | INIT_LIST_HEAD(&iowq.wq.entry); | |
2614 | iowq.ctx = ctx; | |
bda52162 | 2615 | iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts); |
5fd46178 | 2616 | iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events; |
d33a39e5 PB |
2617 | iowq.timeout = KTIME_MAX; |
2618 | ||
2619 | if (uts) { | |
2620 | struct timespec64 ts; | |
2621 | ||
2622 | if (get_timespec64(&ts, uts)) | |
2623 | return -EFAULT; | |
2624 | iowq.timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns()); | |
2625 | } | |
90291099 | 2626 | |
c826bd7a | 2627 | trace_io_uring_cqring_wait(ctx, min_events); |
bda52162 | 2628 | do { |
3fcf19d5 PB |
2629 | unsigned long check_cq; |
2630 | ||
130bd686 | 2631 | if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) { |
8751d154 PB |
2632 | int nr_wait = (int) iowq.cq_tail - READ_ONCE(ctx->rings->cq.tail); |
2633 | ||
2634 | atomic_set(&ctx->cq_wait_nr, nr_wait); | |
130bd686 PB |
2635 | set_current_state(TASK_INTERRUPTIBLE); |
2636 | } else { | |
2637 | prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq, | |
2638 | TASK_INTERRUPTIBLE); | |
2639 | } | |
2640 | ||
d33a39e5 | 2641 | ret = io_cqring_wait_schedule(ctx, &iowq); |
130bd686 | 2642 | __set_current_state(TASK_RUNNING); |
b4bc35cf | 2643 | atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT); |
d80c0f00 | 2644 | |
846072f1 PB |
2645 | /* |
2646 | * Run task_work after scheduling and before io_should_wake(). | |
2647 | * If we got woken because of task_work being processed, run it | |
2648 | * now rather than let the caller do another wait loop. | |
2649 | */ | |
2650 | io_run_task_work(); | |
2651 | if (!llist_empty(&ctx->work_llist)) | |
2652 | io_run_local_work(ctx); | |
3fcf19d5 | 2653 | |
6ff1407e JA |
2654 | /* |
2655 | * Non-local task_work will be run on exit to userspace, but | |
2656 | * if we're using DEFER_TASKRUN, then we could have waited | |
2657 | * with a timeout for a number of requests. If the timeout | |
2658 | * hits, we could have some requests ready to process. Ensure | |
2659 | * this break is _after_ we have run task_work, to avoid | |
2660 | * deferring running potentially pending requests until the | |
2661 | * next time we wait for events. | |
2662 | */ | |
2663 | if (ret < 0) | |
2664 | break; | |
2665 | ||
3fcf19d5 PB |
2666 | check_cq = READ_ONCE(ctx->check_cq); |
2667 | if (unlikely(check_cq)) { | |
2668 | /* let the caller flush overflows, retry */ | |
326a9e48 | 2669 | if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT)) |
3fcf19d5 | 2670 | io_cqring_do_overflow_flush(ctx); |
3fcf19d5 PB |
2671 | if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) { |
2672 | ret = -EBADR; | |
2673 | break; | |
2674 | } | |
2675 | } | |
2676 | ||
846072f1 PB |
2677 | if (io_should_wake(&iowq)) { |
2678 | ret = 0; | |
35d90f95 | 2679 | break; |
846072f1 | 2680 | } |
ca0a2651 | 2681 | cond_resched(); |
846072f1 | 2682 | } while (1); |
bda52162 | 2683 | |
130bd686 PB |
2684 | if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) |
2685 | finish_wait(&ctx->cq_wait, &iowq.wq); | |
b7db41c9 | 2686 | restore_saved_sigmask_unless(ret == -EINTR); |
2b188cc1 | 2687 | |
75b28aff | 2688 | return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0; |
2b188cc1 JA |
2689 | } |
2690 | ||
edecf168 | 2691 | void io_mem_free(void *ptr) |
b9bd2bea | 2692 | { |
73572984 JA |
2693 | if (!ptr) |
2694 | return; | |
b9bd2bea | 2695 | |
99a9e0b8 | 2696 | folio_put(virt_to_folio(ptr)); |
b9bd2bea PB |
2697 | } |
2698 | ||
03d89a2d JA |
2699 | static void io_pages_free(struct page ***pages, int npages) |
2700 | { | |
2701 | struct page **page_array; | |
2702 | int i; | |
2703 | ||
2704 | if (!pages) | |
2705 | return; | |
8b51a395 | 2706 | |
03d89a2d | 2707 | page_array = *pages; |
8b51a395 JA |
2708 | if (!page_array) |
2709 | return; | |
2710 | ||
03d89a2d JA |
2711 | for (i = 0; i < npages; i++) |
2712 | unpin_user_page(page_array[i]); | |
2713 | kvfree(page_array); | |
2714 | *pages = NULL; | |
2715 | } | |
2716 | ||
2717 | static void *__io_uaddr_map(struct page ***pages, unsigned short *npages, | |
2718 | unsigned long uaddr, size_t size) | |
2719 | { | |
2720 | struct page **page_array; | |
2721 | unsigned int nr_pages; | |
820d070f | 2722 | void *page_addr; |
223ef474 | 2723 | int ret, i; |
03d89a2d JA |
2724 | |
2725 | *npages = 0; | |
2726 | ||
2727 | if (uaddr & (PAGE_SIZE - 1) || !size) | |
2728 | return ERR_PTR(-EINVAL); | |
2729 | ||
2730 | nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; | |
2731 | if (nr_pages > USHRT_MAX) | |
2732 | return ERR_PTR(-EINVAL); | |
2733 | page_array = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL); | |
2734 | if (!page_array) | |
2735 | return ERR_PTR(-ENOMEM); | |
2736 | ||
2737 | ret = pin_user_pages_fast(uaddr, nr_pages, FOLL_WRITE | FOLL_LONGTERM, | |
2738 | page_array); | |
2739 | if (ret != nr_pages) { | |
2740 | err: | |
2741 | io_pages_free(&page_array, ret > 0 ? ret : 0); | |
2742 | return ret < 0 ? ERR_PTR(ret) : ERR_PTR(-EFAULT); | |
2743 | } | |
223ef474 | 2744 | |
820d070f | 2745 | page_addr = page_address(page_array[0]); |
223ef474 | 2746 | for (i = 0; i < nr_pages; i++) { |
820d070f JA |
2747 | ret = -EINVAL; |
2748 | ||
2749 | /* | |
2750 | * Can't support mapping user allocated ring memory on 32-bit | |
2751 | * archs where it could potentially reside in highmem. Just | |
2752 | * fail those with -EINVAL, just like we did on kernels that | |
2753 | * didn't support this feature. | |
2754 | */ | |
2755 | if (PageHighMem(page_array[i])) | |
223ef474 | 2756 | goto err; |
820d070f JA |
2757 | |
2758 | /* | |
2759 | * No support for discontig pages for now, should either be a | |
2760 | * single normal page, or a huge page. Later on we can add | |
2761 | * support for remapping discontig pages, for now we will | |
2762 | * just fail them with EINVAL. | |
2763 | */ | |
2764 | if (page_address(page_array[i]) != page_addr) | |
2765 | goto err; | |
2766 | page_addr += PAGE_SIZE; | |
223ef474 JA |
2767 | } |
2768 | ||
03d89a2d JA |
2769 | *pages = page_array; |
2770 | *npages = nr_pages; | |
2771 | return page_to_virt(page_array[0]); | |
2772 | } | |
2773 | ||
2774 | static void *io_rings_map(struct io_ring_ctx *ctx, unsigned long uaddr, | |
2775 | size_t size) | |
2776 | { | |
2777 | return __io_uaddr_map(&ctx->ring_pages, &ctx->n_ring_pages, uaddr, | |
2778 | size); | |
2779 | } | |
2780 | ||
2781 | static void *io_sqes_map(struct io_ring_ctx *ctx, unsigned long uaddr, | |
2782 | size_t size) | |
2783 | { | |
2784 | return __io_uaddr_map(&ctx->sqe_pages, &ctx->n_sqe_pages, uaddr, | |
2785 | size); | |
2786 | } | |
2787 | ||
9c189eee JA |
2788 | static void io_rings_free(struct io_ring_ctx *ctx) |
2789 | { | |
03d89a2d JA |
2790 | if (!(ctx->flags & IORING_SETUP_NO_MMAP)) { |
2791 | io_mem_free(ctx->rings); | |
2792 | io_mem_free(ctx->sq_sqes); | |
2793 | ctx->rings = NULL; | |
2794 | ctx->sq_sqes = NULL; | |
2795 | } else { | |
2796 | io_pages_free(&ctx->ring_pages, ctx->n_ring_pages); | |
8b51a395 | 2797 | ctx->n_ring_pages = 0; |
03d89a2d | 2798 | io_pages_free(&ctx->sqe_pages, ctx->n_sqe_pages); |
8b51a395 | 2799 | ctx->n_sqe_pages = 0; |
03d89a2d | 2800 | } |
9c189eee JA |
2801 | } |
2802 | ||
edecf168 | 2803 | void *io_mem_alloc(size_t size) |
b9bd2bea | 2804 | { |
73572984 | 2805 | gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP; |
e27cef86 | 2806 | void *ret; |
b9bd2bea | 2807 | |
e27cef86 JA |
2808 | ret = (void *) __get_free_pages(gfp, get_order(size)); |
2809 | if (ret) | |
2810 | return ret; | |
2811 | return ERR_PTR(-ENOMEM); | |
b9bd2bea PB |
2812 | } |
2813 | ||
73572984 JA |
2814 | static unsigned long rings_size(struct io_ring_ctx *ctx, unsigned int sq_entries, |
2815 | unsigned int cq_entries, size_t *sq_offset) | |
6b06314c | 2816 | { |
73572984 JA |
2817 | struct io_rings *rings; |
2818 | size_t off, sq_array_size; | |
6b06314c | 2819 | |
73572984 JA |
2820 | off = struct_size(rings, cqes, cq_entries); |
2821 | if (off == SIZE_MAX) | |
2822 | return SIZE_MAX; | |
2823 | if (ctx->flags & IORING_SETUP_CQE32) { | |
2824 | if (check_shl_overflow(off, 1, &off)) | |
2825 | return SIZE_MAX; | |
2826 | } | |
ab409402 | 2827 | |
73572984 JA |
2828 | #ifdef CONFIG_SMP |
2829 | off = ALIGN(off, SMP_CACHE_BYTES); | |
2830 | if (off == 0) | |
2831 | return SIZE_MAX; | |
2832 | #endif | |
82fbcfa9 | 2833 | |
2af89abd PB |
2834 | if (ctx->flags & IORING_SETUP_NO_SQARRAY) { |
2835 | if (sq_offset) | |
2836 | *sq_offset = SIZE_MAX; | |
2837 | return off; | |
2838 | } | |
2839 | ||
73572984 JA |
2840 | if (sq_offset) |
2841 | *sq_offset = off; | |
82fbcfa9 | 2842 | |
73572984 JA |
2843 | sq_array_size = array_size(sizeof(u32), sq_entries); |
2844 | if (sq_array_size == SIZE_MAX) | |
2845 | return SIZE_MAX; | |
6b06314c | 2846 | |
73572984 JA |
2847 | if (check_add_overflow(off, sq_array_size, &off)) |
2848 | return SIZE_MAX; | |
8bad28d8 | 2849 | |
73572984 | 2850 | return off; |
8bad28d8 HX |
2851 | } |
2852 | ||
73572984 | 2853 | static void io_req_caches_free(struct io_ring_ctx *ctx) |
2b188cc1 | 2854 | { |
c8576f3e | 2855 | struct io_kiocb *req; |
37f0e767 | 2856 | int nr = 0; |
bf019da7 | 2857 | |
9a4fdbd8 | 2858 | mutex_lock(&ctx->uring_lock); |
34f0bc42 | 2859 | io_flush_cached_locked_reqs(ctx, &ctx->submit_state); |
9a4fdbd8 | 2860 | |
88ab95be | 2861 | while (!io_req_cache_empty(ctx)) { |
c8576f3e | 2862 | req = io_extract_req(ctx); |
c2b6c6bc | 2863 | kmem_cache_free(req_cachep, req); |
37f0e767 | 2864 | nr++; |
c2b6c6bc | 2865 | } |
37f0e767 PB |
2866 | if (nr) |
2867 | percpu_ref_put_many(&ctx->refs, nr); | |
9a4fdbd8 JA |
2868 | mutex_unlock(&ctx->uring_lock); |
2869 | } | |
2870 | ||
9eae8655 PB |
2871 | static void io_rsrc_node_cache_free(struct io_cache_entry *entry) |
2872 | { | |
2873 | kfree(container_of(entry, struct io_rsrc_node, cache)); | |
2874 | } | |
2875 | ||
c072481d | 2876 | static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx) |
2b188cc1 | 2877 | { |
37d1e2e3 | 2878 | io_sq_thread_finish(ctx); |
43597aac | 2879 | /* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */ |
0b222eeb PB |
2880 | if (WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list))) |
2881 | return; | |
43597aac | 2882 | |
8bad28d8 | 2883 | mutex_lock(&ctx->uring_lock); |
43597aac | 2884 | if (ctx->buf_data) |
bd54b6fe | 2885 | __io_sqe_buffers_unregister(ctx); |
43597aac | 2886 | if (ctx->file_data) |
08480400 | 2887 | __io_sqe_files_unregister(ctx); |
a85381d8 | 2888 | io_cqring_overflow_kill(ctx); |
9b402849 | 2889 | io_eventfd_unregister(ctx); |
9b797a37 | 2890 | io_alloc_cache_free(&ctx->apoll_cache, io_apoll_cache_free); |
43e0bbbd | 2891 | io_alloc_cache_free(&ctx->netmsg_cache, io_netmsg_cache_free); |
194bb58c | 2892 | io_futex_cache_free(ctx); |
5a2e745d | 2893 | io_destroy_buffers(ctx); |
b4a72c05 | 2894 | mutex_unlock(&ctx->uring_lock); |
07db298a PB |
2895 | if (ctx->sq_creds) |
2896 | put_cred(ctx->sq_creds); | |
97bbdc06 PB |
2897 | if (ctx->submitter_task) |
2898 | put_task_struct(ctx->submitter_task); | |
def596e9 | 2899 | |
a7f0ed5a PB |
2900 | /* there are no registered resources left, nobody uses it */ |
2901 | if (ctx->rsrc_node) | |
9eae8655 | 2902 | io_rsrc_node_destroy(ctx, ctx->rsrc_node); |
a7f0ed5a PB |
2903 | |
2904 | WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list)); | |
ef9dd637 | 2905 | WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list)); |
2b188cc1 | 2906 | |
9eae8655 | 2907 | io_alloc_cache_free(&ctx->rsrc_node_cache, io_rsrc_node_cache_free); |
42b6419d PB |
2908 | if (ctx->mm_account) { |
2909 | mmdrop(ctx->mm_account); | |
2910 | ctx->mm_account = NULL; | |
2911 | } | |
9c189eee | 2912 | io_rings_free(ctx); |
c392cbec | 2913 | io_kbuf_mmap_list_free(ctx); |
2b188cc1 JA |
2914 | |
2915 | percpu_ref_exit(&ctx->refs); | |
2b188cc1 | 2916 | free_uid(ctx->user); |
4010fec4 | 2917 | io_req_caches_free(ctx); |
e941894e JA |
2918 | if (ctx->hash_map) |
2919 | io_wq_put_hash(ctx->hash_map); | |
e6f89be6 | 2920 | kfree(ctx->cancel_table.hbs); |
9ca9fb24 | 2921 | kfree(ctx->cancel_table_locked.hbs); |
9cfc7e94 JA |
2922 | kfree(ctx->io_bl); |
2923 | xa_destroy(&ctx->io_bl_xa); | |
2b188cc1 JA |
2924 | kfree(ctx); |
2925 | } | |
2926 | ||
bca39f39 PB |
2927 | static __cold void io_activate_pollwq_cb(struct callback_head *cb) |
2928 | { | |
2929 | struct io_ring_ctx *ctx = container_of(cb, struct io_ring_ctx, | |
2930 | poll_wq_task_work); | |
2931 | ||
2932 | mutex_lock(&ctx->uring_lock); | |
2933 | ctx->poll_activated = true; | |
2934 | mutex_unlock(&ctx->uring_lock); | |
2935 | ||
2936 | /* | |
2937 | * Wake ups for some events between start of polling and activation | |
2938 | * might've been lost due to loose synchronisation. | |
2939 | */ | |
2940 | wake_up_all(&ctx->poll_wq); | |
2941 | percpu_ref_put(&ctx->refs); | |
2942 | } | |
2943 | ||
c4320315 | 2944 | __cold void io_activate_pollwq(struct io_ring_ctx *ctx) |
bca39f39 PB |
2945 | { |
2946 | spin_lock(&ctx->completion_lock); | |
2947 | /* already activated or in progress */ | |
2948 | if (ctx->poll_activated || ctx->poll_wq_task_work.func) | |
2949 | goto out; | |
2950 | if (WARN_ON_ONCE(!ctx->task_complete)) | |
2951 | goto out; | |
2952 | if (!ctx->submitter_task) | |
2953 | goto out; | |
2954 | /* | |
2955 | * with ->submitter_task only the submitter task completes requests, we | |
2956 | * only need to sync with it, which is done by injecting a tw | |
2957 | */ | |
2958 | init_task_work(&ctx->poll_wq_task_work, io_activate_pollwq_cb); | |
2959 | percpu_ref_get(&ctx->refs); | |
2960 | if (task_work_add(ctx->submitter_task, &ctx->poll_wq_task_work, TWA_SIGNAL)) | |
2961 | percpu_ref_put(&ctx->refs); | |
2962 | out: | |
2963 | spin_unlock(&ctx->completion_lock); | |
2964 | } | |
2965 | ||
2b188cc1 JA |
2966 | static __poll_t io_uring_poll(struct file *file, poll_table *wait) |
2967 | { | |
2968 | struct io_ring_ctx *ctx = file->private_data; | |
2969 | __poll_t mask = 0; | |
2970 | ||
bca39f39 PB |
2971 | if (unlikely(!ctx->poll_activated)) |
2972 | io_activate_pollwq(ctx); | |
2973 | ||
7b235dd8 | 2974 | poll_wait(file, &ctx->poll_wq, wait); |
4f7067c3 SB |
2975 | /* |
2976 | * synchronizes with barrier from wq_has_sleeper call in | |
2977 | * io_commit_cqring | |
2978 | */ | |
2b188cc1 | 2979 | smp_rmb(); |
90554200 | 2980 | if (!io_sqring_full(ctx)) |
2b188cc1 | 2981 | mask |= EPOLLOUT | EPOLLWRNORM; |
ed670c3f HX |
2982 | |
2983 | /* | |
2984 | * Don't flush cqring overflow list here, just do a simple check. | |
2985 | * Otherwise there could possible be ABBA deadlock: | |
2986 | * CPU0 CPU1 | |
2987 | * ---- ---- | |
2988 | * lock(&ctx->uring_lock); | |
2989 | * lock(&ep->mtx); | |
2990 | * lock(&ctx->uring_lock); | |
2991 | * lock(&ep->mtx); | |
2992 | * | |
2993 | * Users may get EPOLLIN meanwhile seeing nothing in cqring, this | |
10d8bc35 | 2994 | * pushes them to do the flush. |
ed670c3f | 2995 | */ |
b4c98d59 | 2996 | |
c10bb646 | 2997 | if (__io_cqring_events_user(ctx) || io_has_work(ctx)) |
2b188cc1 JA |
2998 | mask |= EPOLLIN | EPOLLRDNORM; |
2999 | ||
3000 | return mask; | |
3001 | } | |
3002 | ||
d56d938b PB |
3003 | struct io_tctx_exit { |
3004 | struct callback_head task_work; | |
3005 | struct completion completion; | |
baf186c4 | 3006 | struct io_ring_ctx *ctx; |
d56d938b PB |
3007 | }; |
3008 | ||
c072481d | 3009 | static __cold void io_tctx_exit_cb(struct callback_head *cb) |
d56d938b PB |
3010 | { |
3011 | struct io_uring_task *tctx = current->io_uring; | |
3012 | struct io_tctx_exit *work; | |
3013 | ||
3014 | work = container_of(cb, struct io_tctx_exit, task_work); | |
3015 | /* | |
8d664282 | 3016 | * When @in_cancel, we're in cancellation and it's racy to remove the |
d56d938b | 3017 | * node. It'll be removed by the end of cancellation, just ignore it. |
998b30c3 HM |
3018 | * tctx can be NULL if the queueing of this task_work raced with |
3019 | * work cancelation off the exec path. | |
d56d938b | 3020 | */ |
8d664282 | 3021 | if (tctx && !atomic_read(&tctx->in_cancel)) |
eef51daa | 3022 | io_uring_del_tctx_node((unsigned long)work->ctx); |
d56d938b PB |
3023 | complete(&work->completion); |
3024 | } | |
3025 | ||
c072481d | 3026 | static __cold bool io_cancel_ctx_cb(struct io_wq_work *work, void *data) |
28090c13 PB |
3027 | { |
3028 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); | |
3029 | ||
3030 | return req->ctx == data; | |
3031 | } | |
3032 | ||
c072481d | 3033 | static __cold void io_ring_exit_work(struct work_struct *work) |
85faa7b8 | 3034 | { |
d56d938b | 3035 | struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work); |
b5bb3a24 | 3036 | unsigned long timeout = jiffies + HZ * 60 * 5; |
58d3be2c | 3037 | unsigned long interval = HZ / 20; |
d56d938b PB |
3038 | struct io_tctx_exit exit; |
3039 | struct io_tctx_node *node; | |
3040 | int ret; | |
85faa7b8 | 3041 | |
56952e91 JA |
3042 | /* |
3043 | * If we're doing polled IO and end up having requests being | |
3044 | * submitted async (out-of-line), then completions can come in while | |
3045 | * we're waiting for refs to drop. We need to reap these manually, | |
3046 | * as nobody else will be looking for them. | |
3047 | */ | |
b2edc0a7 | 3048 | do { |
a85381d8 PB |
3049 | if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)) { |
3050 | mutex_lock(&ctx->uring_lock); | |
3051 | io_cqring_overflow_kill(ctx); | |
3052 | mutex_unlock(&ctx->uring_lock); | |
3053 | } | |
3054 | ||
c0e0d6ba DY |
3055 | if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) |
3056 | io_move_task_work_from_local(ctx); | |
3057 | ||
affa87db PB |
3058 | while (io_uring_try_cancel_requests(ctx, NULL, true)) |
3059 | cond_resched(); | |
3060 | ||
28090c13 PB |
3061 | if (ctx->sq_data) { |
3062 | struct io_sq_data *sqd = ctx->sq_data; | |
3063 | struct task_struct *tsk; | |
3064 | ||
3065 | io_sq_thread_park(sqd); | |
3066 | tsk = sqd->thread; | |
3067 | if (tsk && tsk->io_uring && tsk->io_uring->io_wq) | |
3068 | io_wq_cancel_cb(tsk->io_uring->io_wq, | |
3069 | io_cancel_ctx_cb, ctx, true); | |
3070 | io_sq_thread_unpark(sqd); | |
3071 | } | |
b5bb3a24 | 3072 | |
37f0e767 PB |
3073 | io_req_caches_free(ctx); |
3074 | ||
58d3be2c PB |
3075 | if (WARN_ON_ONCE(time_after(jiffies, timeout))) { |
3076 | /* there is little hope left, don't run it too often */ | |
3077 | interval = HZ * 60; | |
3078 | } | |
4826c594 JA |
3079 | /* |
3080 | * This is really an uninterruptible wait, as it has to be | |
3081 | * complete. But it's also run from a kworker, which doesn't | |
3082 | * take signals, so it's fine to make it interruptible. This | |
3083 | * avoids scenarios where we knowingly can wait much longer | |
3084 | * on completions, for example if someone does a SIGSTOP on | |
3085 | * a task that needs to finish task_work to make this loop | |
3086 | * complete. That's a synthetic situation that should not | |
3087 | * cause a stuck task backtrace, and hence a potential panic | |
3088 | * on stuck tasks if that is enabled. | |
3089 | */ | |
3090 | } while (!wait_for_completion_interruptible_timeout(&ctx->ref_comp, interval)); | |
d56d938b | 3091 | |
7f00651a PB |
3092 | init_completion(&exit.completion); |
3093 | init_task_work(&exit.task_work, io_tctx_exit_cb); | |
3094 | exit.ctx = ctx; | |
f7b32e78 | 3095 | |
d56d938b PB |
3096 | mutex_lock(&ctx->uring_lock); |
3097 | while (!list_empty(&ctx->tctx_list)) { | |
b5bb3a24 PB |
3098 | WARN_ON_ONCE(time_after(jiffies, timeout)); |
3099 | ||
d56d938b PB |
3100 | node = list_first_entry(&ctx->tctx_list, struct io_tctx_node, |
3101 | ctx_node); | |
7f00651a PB |
3102 | /* don't spin on a single task if cancellation failed */ |
3103 | list_rotate_left(&ctx->tctx_list); | |
d56d938b PB |
3104 | ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL); |
3105 | if (WARN_ON_ONCE(ret)) | |
3106 | continue; | |
d56d938b PB |
3107 | |
3108 | mutex_unlock(&ctx->uring_lock); | |
4826c594 JA |
3109 | /* |
3110 | * See comment above for | |
3111 | * wait_for_completion_interruptible_timeout() on why this | |
3112 | * wait is marked as interruptible. | |
3113 | */ | |
3114 | wait_for_completion_interruptible(&exit.completion); | |
d56d938b PB |
3115 | mutex_lock(&ctx->uring_lock); |
3116 | } | |
3117 | mutex_unlock(&ctx->uring_lock); | |
79ebeaee JA |
3118 | spin_lock(&ctx->completion_lock); |
3119 | spin_unlock(&ctx->completion_lock); | |
d56d938b | 3120 | |
d73a572d PB |
3121 | /* pairs with RCU read section in io_req_local_work_add() */ |
3122 | if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) | |
3123 | synchronize_rcu(); | |
3124 | ||
85faa7b8 JA |
3125 | io_ring_ctx_free(ctx); |
3126 | } | |
3127 | ||
c072481d | 3128 | static __cold void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) |
2b188cc1 | 3129 | { |
61cf9370 MWO |
3130 | unsigned long index; |
3131 | struct creds *creds; | |
3132 | ||
2b188cc1 JA |
3133 | mutex_lock(&ctx->uring_lock); |
3134 | percpu_ref_kill(&ctx->refs); | |
61cf9370 MWO |
3135 | xa_for_each(&ctx->personalities, index, creds) |
3136 | io_unregister_personality(ctx, index); | |
9ca9fb24 PB |
3137 | if (ctx->rings) |
3138 | io_poll_remove_all(ctx, NULL, true); | |
2b188cc1 JA |
3139 | mutex_unlock(&ctx->uring_lock); |
3140 | ||
02bac94b PB |
3141 | /* |
3142 | * If we failed setting up the ctx, we might not have any rings | |
3143 | * and therefore did not submit any requests | |
3144 | */ | |
3145 | if (ctx->rings) | |
60053be8 | 3146 | io_kill_timeouts(ctx, NULL, true); |
309fc03a | 3147 | |
dfbe5561 JA |
3148 | flush_delayed_work(&ctx->fallback_work); |
3149 | ||
85faa7b8 | 3150 | INIT_WORK(&ctx->exit_work, io_ring_exit_work); |
fc666777 JA |
3151 | /* |
3152 | * Use system_unbound_wq to avoid spawning tons of event kworkers | |
3153 | * if we're exiting a ton of rings at the same time. It just adds | |
3154 | * noise and overhead, there's no discernable change in runtime | |
3155 | * over using system_wq. | |
3156 | */ | |
3157 | queue_work(system_unbound_wq, &ctx->exit_work); | |
2b188cc1 JA |
3158 | } |
3159 | ||
3160 | static int io_uring_release(struct inode *inode, struct file *file) | |
3161 | { | |
3162 | struct io_ring_ctx *ctx = file->private_data; | |
3163 | ||
3164 | file->private_data = NULL; | |
3165 | io_ring_ctx_wait_and_kill(ctx); | |
3166 | return 0; | |
3167 | } | |
3168 | ||
f6edbabb PB |
3169 | struct io_task_cancel { |
3170 | struct task_struct *task; | |
3dd0c97a | 3171 | bool all; |
f6edbabb | 3172 | }; |
f254ac04 | 3173 | |
f6edbabb | 3174 | static bool io_cancel_task_cb(struct io_wq_work *work, void *data) |
b711d4ea | 3175 | { |
9a472ef7 | 3176 | struct io_kiocb *req = container_of(work, struct io_kiocb, work); |
f6edbabb | 3177 | struct io_task_cancel *cancel = data; |
9a472ef7 | 3178 | |
6af3f48b | 3179 | return io_match_task_safe(req, cancel->task, cancel->all); |
b711d4ea JA |
3180 | } |
3181 | ||
c072481d PB |
3182 | static __cold bool io_cancel_defer_files(struct io_ring_ctx *ctx, |
3183 | struct task_struct *task, | |
3184 | bool cancel_all) | |
b7ddce3c | 3185 | { |
e1915f76 | 3186 | struct io_defer_entry *de; |
b7ddce3c PB |
3187 | LIST_HEAD(list); |
3188 | ||
79ebeaee | 3189 | spin_lock(&ctx->completion_lock); |
b7ddce3c | 3190 | list_for_each_entry_reverse(de, &ctx->defer_list, list) { |
6af3f48b | 3191 | if (io_match_task_safe(de->req, task, cancel_all)) { |
b7ddce3c PB |
3192 | list_cut_position(&list, &ctx->defer_list, &de->list); |
3193 | break; | |
3194 | } | |
3195 | } | |
79ebeaee | 3196 | spin_unlock(&ctx->completion_lock); |
e1915f76 PB |
3197 | if (list_empty(&list)) |
3198 | return false; | |
b7ddce3c PB |
3199 | |
3200 | while (!list_empty(&list)) { | |
3201 | de = list_first_entry(&list, struct io_defer_entry, list); | |
3202 | list_del_init(&de->list); | |
e276ae34 | 3203 | io_req_task_queue_fail(de->req, -ECANCELED); |
b7ddce3c PB |
3204 | kfree(de); |
3205 | } | |
e1915f76 | 3206 | return true; |
b7ddce3c PB |
3207 | } |
3208 | ||
c072481d | 3209 | static __cold bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx) |
1b00764f PB |
3210 | { |
3211 | struct io_tctx_node *node; | |
3212 | enum io_wq_cancel cret; | |
3213 | bool ret = false; | |
3214 | ||
3215 | mutex_lock(&ctx->uring_lock); | |
3216 | list_for_each_entry(node, &ctx->tctx_list, ctx_node) { | |
3217 | struct io_uring_task *tctx = node->task->io_uring; | |
3218 | ||
3219 | /* | |
3220 | * io_wq will stay alive while we hold uring_lock, because it's | |
3221 | * killed after ctx nodes, which requires to take the lock. | |
3222 | */ | |
3223 | if (!tctx || !tctx->io_wq) | |
3224 | continue; | |
3225 | cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true); | |
3226 | ret |= (cret != IO_WQ_CANCEL_NOTFOUND); | |
3227 | } | |
3228 | mutex_unlock(&ctx->uring_lock); | |
3229 | ||
3230 | return ret; | |
3231 | } | |
3232 | ||
93b8cc60 ML |
3233 | static bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx *ctx, |
3234 | struct task_struct *task, bool cancel_all) | |
3235 | { | |
3236 | struct hlist_node *tmp; | |
3237 | struct io_kiocb *req; | |
3238 | bool ret = false; | |
3239 | ||
3240 | lockdep_assert_held(&ctx->uring_lock); | |
3241 | ||
3242 | hlist_for_each_entry_safe(req, tmp, &ctx->cancelable_uring_cmd, | |
3243 | hash_node) { | |
3244 | struct io_uring_cmd *cmd = io_kiocb_to_cmd(req, | |
3245 | struct io_uring_cmd); | |
3246 | struct file *file = req->file; | |
3247 | ||
3248 | if (!cancel_all && req->task != task) | |
3249 | continue; | |
3250 | ||
3251 | if (cmd->flags & IORING_URING_CMD_CANCELABLE) { | |
3252 | /* ->sqe isn't available if no async data */ | |
3253 | if (!req_has_async_data(req)) | |
3254 | cmd->sqe = NULL; | |
3255 | file->f_op->uring_cmd(cmd, IO_URING_F_CANCEL); | |
3256 | ret = true; | |
3257 | } | |
3258 | } | |
3259 | io_submit_flush_completions(ctx); | |
3260 | ||
3261 | return ret; | |
3262 | } | |
3263 | ||
affa87db | 3264 | static __cold bool io_uring_try_cancel_requests(struct io_ring_ctx *ctx, |
c072481d PB |
3265 | struct task_struct *task, |
3266 | bool cancel_all) | |
9936c7c2 | 3267 | { |
3dd0c97a | 3268 | struct io_task_cancel cancel = { .task = task, .all = cancel_all, }; |
1b00764f | 3269 | struct io_uring_task *tctx = task ? task->io_uring : NULL; |
affa87db PB |
3270 | enum io_wq_cancel cret; |
3271 | bool ret = false; | |
9936c7c2 | 3272 | |
360cd42c PB |
3273 | /* set it so io_req_local_work_add() would wake us up */ |
3274 | if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) { | |
3275 | atomic_set(&ctx->cq_wait_nr, 1); | |
3276 | smp_mb(); | |
3277 | } | |
3278 | ||
60053be8 PB |
3279 | /* failed during ring init, it couldn't have issued any requests */ |
3280 | if (!ctx->rings) | |
affa87db | 3281 | return false; |
60053be8 | 3282 | |
affa87db PB |
3283 | if (!task) { |
3284 | ret |= io_uring_try_cancel_iowq(ctx); | |
3285 | } else if (tctx && tctx->io_wq) { | |
3286 | /* | |
3287 | * Cancels requests of all rings, not only @ctx, but | |
3288 | * it's fine as the task is in exit/exec. | |
3289 | */ | |
3290 | cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb, | |
3291 | &cancel, true); | |
3292 | ret |= (cret != IO_WQ_CANCEL_NOTFOUND); | |
3293 | } | |
9936c7c2 | 3294 | |
affa87db PB |
3295 | /* SQPOLL thread does its own polling */ |
3296 | if ((!(ctx->flags & IORING_SETUP_SQPOLL) && cancel_all) || | |
3297 | (ctx->sq_data && ctx->sq_data->thread == current)) { | |
3298 | while (!wq_list_empty(&ctx->iopoll_list)) { | |
3299 | io_iopoll_try_reap_events(ctx); | |
3300 | ret = true; | |
fcc926bb | 3301 | cond_resched(); |
9936c7c2 | 3302 | } |
9936c7c2 | 3303 | } |
affa87db | 3304 | |
140102ae PB |
3305 | if ((ctx->flags & IORING_SETUP_DEFER_TASKRUN) && |
3306 | io_allowed_defer_tw_run(ctx)) | |
c0e0d6ba | 3307 | ret |= io_run_local_work(ctx) > 0; |
affa87db PB |
3308 | ret |= io_cancel_defer_files(ctx, task, cancel_all); |
3309 | mutex_lock(&ctx->uring_lock); | |
3310 | ret |= io_poll_remove_all(ctx, task, cancel_all); | |
f31ecf67 | 3311 | ret |= io_waitid_remove_all(ctx, task, cancel_all); |
194bb58c | 3312 | ret |= io_futex_remove_all(ctx, task, cancel_all); |
93b8cc60 | 3313 | ret |= io_uring_try_cancel_uring_cmd(ctx, task, cancel_all); |
affa87db PB |
3314 | mutex_unlock(&ctx->uring_lock); |
3315 | ret |= io_kill_timeouts(ctx, task, cancel_all); | |
3316 | if (task) | |
c0e0d6ba | 3317 | ret |= io_run_task_work() > 0; |
affa87db | 3318 | return ret; |
9936c7c2 PB |
3319 | } |
3320 | ||
3f48cf18 | 3321 | static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked) |
521d6a73 | 3322 | { |
3f48cf18 | 3323 | if (tracked) |
9cae36a0 | 3324 | return atomic_read(&tctx->inflight_tracked); |
521d6a73 PB |
3325 | return percpu_counter_sum(&tctx->inflight); |
3326 | } | |
3327 | ||
78cc687b PB |
3328 | /* |
3329 | * Find any io_uring ctx that this task has registered or done IO on, and cancel | |
78a78060 | 3330 | * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation. |
78cc687b | 3331 | */ |
17437f31 | 3332 | __cold void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd) |
0e9ddb39 | 3333 | { |
521d6a73 | 3334 | struct io_uring_task *tctx = current->io_uring; |
734551df | 3335 | struct io_ring_ctx *ctx; |
360cd42c PB |
3336 | struct io_tctx_node *node; |
3337 | unsigned long index; | |
0e9ddb39 PB |
3338 | s64 inflight; |
3339 | DEFINE_WAIT(wait); | |
fdaf083c | 3340 | |
78cc687b PB |
3341 | WARN_ON_ONCE(sqd && sqd->thread != current); |
3342 | ||
6d042ffb PO |
3343 | if (!current->io_uring) |
3344 | return; | |
17a91051 PB |
3345 | if (tctx->io_wq) |
3346 | io_wq_exit_start(tctx->io_wq); | |
3347 | ||
8d664282 | 3348 | atomic_inc(&tctx->in_cancel); |
0e9ddb39 | 3349 | do { |
affa87db PB |
3350 | bool loop = false; |
3351 | ||
e9dbe221 | 3352 | io_uring_drop_tctx_refs(current); |
0e9ddb39 | 3353 | /* read completions before cancelations */ |
78cc687b | 3354 | inflight = tctx_inflight(tctx, !cancel_all); |
0e9ddb39 PB |
3355 | if (!inflight) |
3356 | break; | |
fdaf083c | 3357 | |
78cc687b | 3358 | if (!sqd) { |
78cc687b PB |
3359 | xa_for_each(&tctx->xa, index, node) { |
3360 | /* sqpoll task will cancel all its requests */ | |
3361 | if (node->ctx->sq_data) | |
3362 | continue; | |
affa87db PB |
3363 | loop |= io_uring_try_cancel_requests(node->ctx, |
3364 | current, cancel_all); | |
78cc687b PB |
3365 | } |
3366 | } else { | |
3367 | list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) | |
affa87db PB |
3368 | loop |= io_uring_try_cancel_requests(ctx, |
3369 | current, | |
3370 | cancel_all); | |
3371 | } | |
3372 | ||
3373 | if (loop) { | |
3374 | cond_resched(); | |
3375 | continue; | |
78cc687b | 3376 | } |
17a91051 | 3377 | |
78a78060 JA |
3378 | prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE); |
3379 | io_run_task_work(); | |
e9dbe221 | 3380 | io_uring_drop_tctx_refs(current); |
360cd42c PB |
3381 | xa_for_each(&tctx->xa, index, node) { |
3382 | if (!llist_empty(&node->ctx->work_llist)) { | |
3383 | WARN_ON_ONCE(node->ctx->submitter_task && | |
3384 | node->ctx->submitter_task != current); | |
3385 | goto end_wait; | |
3386 | } | |
3387 | } | |
0f212204 | 3388 | /* |
a1bb3cd5 PB |
3389 | * If we've seen completions, retry without waiting. This |
3390 | * avoids a race where a completion comes in before we did | |
3391 | * prepare_to_wait(). | |
0f212204 | 3392 | */ |
3dd0c97a | 3393 | if (inflight == tctx_inflight(tctx, !cancel_all)) |
a1bb3cd5 | 3394 | schedule(); |
360cd42c | 3395 | end_wait: |
f57555ed | 3396 | finish_wait(&tctx->wait, &wait); |
d8a6df10 | 3397 | } while (1); |
de7f1d9e | 3398 | |
8452d4a6 | 3399 | io_uring_clean_tctx(tctx); |
3dd0c97a | 3400 | if (cancel_all) { |
3cc7fdb9 PB |
3401 | /* |
3402 | * We shouldn't run task_works after cancel, so just leave | |
8d664282 | 3403 | * ->in_cancel set for normal exit. |
3cc7fdb9 | 3404 | */ |
8d664282 | 3405 | atomic_dec(&tctx->in_cancel); |
3f48cf18 PB |
3406 | /* for exec all current's requests should be gone, kill tctx */ |
3407 | __io_uring_free(current); | |
3408 | } | |
44e728b8 PB |
3409 | } |
3410 | ||
f552a27a | 3411 | void __io_uring_cancel(bool cancel_all) |
78cc687b | 3412 | { |
f552a27a | 3413 | io_uring_cancel_generic(cancel_all, NULL); |
78cc687b PB |
3414 | } |
3415 | ||
6c5c240e RP |
3416 | static void *io_uring_validate_mmap_request(struct file *file, |
3417 | loff_t pgoff, size_t sz) | |
2b188cc1 | 3418 | { |
2b188cc1 | 3419 | struct io_ring_ctx *ctx = file->private_data; |
6c5c240e | 3420 | loff_t offset = pgoff << PAGE_SHIFT; |
2b188cc1 JA |
3421 | struct page *page; |
3422 | void *ptr; | |
3423 | ||
c56e022c | 3424 | switch (offset & IORING_OFF_MMAP_MASK) { |
2b188cc1 | 3425 | case IORING_OFF_SQ_RING: |
75b28aff | 3426 | case IORING_OFF_CQ_RING: |
6f007b14 JA |
3427 | /* Don't allow mmap if the ring was setup without it */ |
3428 | if (ctx->flags & IORING_SETUP_NO_MMAP) | |
3429 | return ERR_PTR(-EINVAL); | |
75b28aff | 3430 | ptr = ctx->rings; |
2b188cc1 JA |
3431 | break; |
3432 | case IORING_OFF_SQES: | |
6f007b14 JA |
3433 | /* Don't allow mmap if the ring was setup without it */ |
3434 | if (ctx->flags & IORING_SETUP_NO_MMAP) | |
3435 | return ERR_PTR(-EINVAL); | |
2b188cc1 JA |
3436 | ptr = ctx->sq_sqes; |
3437 | break; | |
c56e022c JA |
3438 | case IORING_OFF_PBUF_RING: { |
3439 | unsigned int bgid; | |
3440 | ||
3441 | bgid = (offset & ~IORING_OFF_MMAP_MASK) >> IORING_OFF_PBUF_SHIFT; | |
5cf4f52e | 3442 | rcu_read_lock(); |
c56e022c | 3443 | ptr = io_pbuf_get_address(ctx, bgid); |
5cf4f52e | 3444 | rcu_read_unlock(); |
c56e022c JA |
3445 | if (!ptr) |
3446 | return ERR_PTR(-EINVAL); | |
3447 | break; | |
3448 | } | |
2b188cc1 | 3449 | default: |
6c5c240e | 3450 | return ERR_PTR(-EINVAL); |
2b188cc1 JA |
3451 | } |
3452 | ||
3453 | page = virt_to_head_page(ptr); | |
a50b854e | 3454 | if (sz > page_size(page)) |
6c5c240e RP |
3455 | return ERR_PTR(-EINVAL); |
3456 | ||
3457 | return ptr; | |
3458 | } | |
3459 | ||
3460 | #ifdef CONFIG_MMU | |
3461 | ||
c072481d | 3462 | static __cold int io_uring_mmap(struct file *file, struct vm_area_struct *vma) |
6c5c240e RP |
3463 | { |
3464 | size_t sz = vma->vm_end - vma->vm_start; | |
3465 | unsigned long pfn; | |
3466 | void *ptr; | |
3467 | ||
3468 | ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz); | |
3469 | if (IS_ERR(ptr)) | |
3470 | return PTR_ERR(ptr); | |
2b188cc1 JA |
3471 | |
3472 | pfn = virt_to_phys(ptr) >> PAGE_SHIFT; | |
3473 | return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); | |
3474 | } | |
3475 | ||
d808459b HD |
3476 | static unsigned long io_uring_mmu_get_unmapped_area(struct file *filp, |
3477 | unsigned long addr, unsigned long len, | |
3478 | unsigned long pgoff, unsigned long flags) | |
3479 | { | |
d808459b HD |
3480 | void *ptr; |
3481 | ||
3482 | /* | |
3483 | * Do not allow to map to user-provided address to avoid breaking the | |
3484 | * aliasing rules. Userspace is not able to guess the offset address of | |
3485 | * kernel kmalloc()ed memory area. | |
3486 | */ | |
3487 | if (addr) | |
3488 | return -EINVAL; | |
3489 | ||
3490 | ptr = io_uring_validate_mmap_request(filp, pgoff, len); | |
3491 | if (IS_ERR(ptr)) | |
3492 | return -ENOMEM; | |
3493 | ||
32832a40 HD |
3494 | /* |
3495 | * Some architectures have strong cache aliasing requirements. | |
3496 | * For such architectures we need a coherent mapping which aliases | |
3497 | * kernel memory *and* userspace memory. To achieve that: | |
3498 | * - use a NULL file pointer to reference physical memory, and | |
3499 | * - use the kernel virtual address of the shared io_uring context | |
3500 | * (instead of the userspace-provided address, which has to be 0UL | |
3501 | * anyway). | |
56675f8b HD |
3502 | * - use the same pgoff which the get_unmapped_area() uses to |
3503 | * calculate the page colouring. | |
32832a40 HD |
3504 | * For architectures without such aliasing requirements, the |
3505 | * architecture will return any suitable mapping because addr is 0. | |
3506 | */ | |
3507 | filp = NULL; | |
3508 | flags |= MAP_SHARED; | |
3509 | pgoff = 0; /* has been translated to ptr above */ | |
d808459b | 3510 | #ifdef SHM_COLOUR |
32832a40 | 3511 | addr = (uintptr_t) ptr; |
56675f8b | 3512 | pgoff = addr >> PAGE_SHIFT; |
d808459b | 3513 | #else |
32832a40 | 3514 | addr = 0UL; |
d808459b | 3515 | #endif |
32832a40 | 3516 | return current->mm->get_unmapped_area(filp, addr, len, pgoff, flags); |
d808459b HD |
3517 | } |
3518 | ||
6c5c240e RP |
3519 | #else /* !CONFIG_MMU */ |
3520 | ||
3521 | static int io_uring_mmap(struct file *file, struct vm_area_struct *vma) | |
3522 | { | |
fc4f4be9 | 3523 | return is_nommu_shared_mapping(vma->vm_flags) ? 0 : -EINVAL; |
6c5c240e RP |
3524 | } |
3525 | ||
3526 | static unsigned int io_uring_nommu_mmap_capabilities(struct file *file) | |
3527 | { | |
3528 | return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE; | |
3529 | } | |
3530 | ||
3531 | static unsigned long io_uring_nommu_get_unmapped_area(struct file *file, | |
3532 | unsigned long addr, unsigned long len, | |
3533 | unsigned long pgoff, unsigned long flags) | |
3534 | { | |
3535 | void *ptr; | |
3536 | ||
3537 | ptr = io_uring_validate_mmap_request(file, pgoff, len); | |
3538 | if (IS_ERR(ptr)) | |
3539 | return PTR_ERR(ptr); | |
3540 | ||
3541 | return (unsigned long) ptr; | |
3542 | } | |
3543 | ||
3544 | #endif /* !CONFIG_MMU */ | |
3545 | ||
f81440d3 PB |
3546 | static int io_validate_ext_arg(unsigned flags, const void __user *argp, size_t argsz) |
3547 | { | |
3548 | if (flags & IORING_ENTER_EXT_ARG) { | |
3549 | struct io_uring_getevents_arg arg; | |
3550 | ||
3551 | if (argsz != sizeof(arg)) | |
3552 | return -EINVAL; | |
3553 | if (copy_from_user(&arg, argp, sizeof(arg))) | |
3554 | return -EFAULT; | |
3555 | } | |
3556 | return 0; | |
3557 | } | |
3558 | ||
c73ebb68 HX |
3559 | static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz, |
3560 | struct __kernel_timespec __user **ts, | |
3561 | const sigset_t __user **sig) | |
3562 | { | |
3563 | struct io_uring_getevents_arg arg; | |
3564 | ||
3565 | /* | |
3566 | * If EXT_ARG isn't set, then we have no timespec and the argp pointer | |
3567 | * is just a pointer to the sigset_t. | |
3568 | */ | |
3569 | if (!(flags & IORING_ENTER_EXT_ARG)) { | |
3570 | *sig = (const sigset_t __user *) argp; | |
3571 | *ts = NULL; | |
3572 | return 0; | |
3573 | } | |
3574 | ||
3575 | /* | |
3576 | * EXT_ARG is set - ensure we agree on the size of it and copy in our | |
3577 | * timespec and sigset_t pointers if good. | |
3578 | */ | |
3579 | if (*argsz != sizeof(arg)) | |
3580 | return -EINVAL; | |
3581 | if (copy_from_user(&arg, argp, sizeof(arg))) | |
3582 | return -EFAULT; | |
d2347b96 DY |
3583 | if (arg.pad) |
3584 | return -EINVAL; | |
c73ebb68 HX |
3585 | *sig = u64_to_user_ptr(arg.sigmask); |
3586 | *argsz = arg.sigmask_sz; | |
3587 | *ts = u64_to_user_ptr(arg.ts); | |
3588 | return 0; | |
3589 | } | |
3590 | ||
2b188cc1 | 3591 | SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit, |
c73ebb68 HX |
3592 | u32, min_complete, u32, flags, const void __user *, argp, |
3593 | size_t, argsz) | |
2b188cc1 JA |
3594 | { |
3595 | struct io_ring_ctx *ctx; | |
73363c26 | 3596 | struct file *file; |
33f993da | 3597 | long ret; |
2b188cc1 | 3598 | |
33f993da | 3599 | if (unlikely(flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP | |
e7a6c00d JA |
3600 | IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG | |
3601 | IORING_ENTER_REGISTERED_RING))) | |
2b188cc1 JA |
3602 | return -EINVAL; |
3603 | ||
e7a6c00d JA |
3604 | /* |
3605 | * Ring fd has been registered via IORING_REGISTER_RING_FDS, we | |
3606 | * need only dereference our task private array to find it. | |
3607 | */ | |
3608 | if (flags & IORING_ENTER_REGISTERED_RING) { | |
3609 | struct io_uring_task *tctx = current->io_uring; | |
3610 | ||
3273c440 | 3611 | if (unlikely(!tctx || fd >= IO_RINGFD_REG_MAX)) |
e7a6c00d JA |
3612 | return -EINVAL; |
3613 | fd = array_index_nospec(fd, IO_RINGFD_REG_MAX); | |
73363c26 JA |
3614 | file = tctx->registered_rings[fd]; |
3615 | if (unlikely(!file)) | |
3273c440 | 3616 | return -EBADF; |
e7a6c00d | 3617 | } else { |
73363c26 JA |
3618 | file = fget(fd); |
3619 | if (unlikely(!file)) | |
3273c440 PB |
3620 | return -EBADF; |
3621 | ret = -EOPNOTSUPP; | |
73363c26 | 3622 | if (unlikely(!io_is_uring_fops(file))) |
fbb8bb02 | 3623 | goto out; |
e7a6c00d | 3624 | } |
2b188cc1 | 3625 | |
73363c26 | 3626 | ctx = file->private_data; |
7e84e1c7 | 3627 | ret = -EBADFD; |
33f993da | 3628 | if (unlikely(ctx->flags & IORING_SETUP_R_DISABLED)) |
7e84e1c7 SG |
3629 | goto out; |
3630 | ||
6c271ce2 JA |
3631 | /* |
3632 | * For SQ polling, the thread will do all submissions and completions. | |
3633 | * Just return the requested submit count, and wake the thread if | |
3634 | * we were asked to. | |
3635 | */ | |
b2a9eada | 3636 | ret = 0; |
6c271ce2 | 3637 | if (ctx->flags & IORING_SETUP_SQPOLL) { |
90f67366 | 3638 | io_cqring_overflow_flush(ctx); |
89448c47 | 3639 | |
21f96522 JA |
3640 | if (unlikely(ctx->sq_data->thread == NULL)) { |
3641 | ret = -EOWNERDEAD; | |
04147488 | 3642 | goto out; |
21f96522 | 3643 | } |
6c271ce2 | 3644 | if (flags & IORING_ENTER_SQ_WAKEUP) |
534ca6d6 | 3645 | wake_up(&ctx->sq_data->wait); |
88b80534 QF |
3646 | if (flags & IORING_ENTER_SQ_WAIT) |
3647 | io_sqpoll_wait_sq(ctx); | |
3648 | ||
3e813c90 | 3649 | ret = to_submit; |
b2a9eada | 3650 | } else if (to_submit) { |
eef51daa | 3651 | ret = io_uring_add_tctx_node(ctx); |
0f212204 JA |
3652 | if (unlikely(ret)) |
3653 | goto out; | |
7c504e65 | 3654 | |
2b188cc1 | 3655 | mutex_lock(&ctx->uring_lock); |
3e813c90 DY |
3656 | ret = io_submit_sqes(ctx, to_submit); |
3657 | if (ret != to_submit) { | |
d487b43c | 3658 | mutex_unlock(&ctx->uring_lock); |
7c504e65 | 3659 | goto out; |
d487b43c | 3660 | } |
44f87745 PB |
3661 | if (flags & IORING_ENTER_GETEVENTS) { |
3662 | if (ctx->syscall_iopoll) | |
3663 | goto iopoll_locked; | |
3664 | /* | |
3665 | * Ignore errors, we'll soon call io_cqring_wait() and | |
3666 | * it should handle ownership problems if any. | |
3667 | */ | |
3668 | if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) | |
3669 | (void)io_run_local_work_locked(ctx); | |
3670 | } | |
d487b43c | 3671 | mutex_unlock(&ctx->uring_lock); |
2b188cc1 | 3672 | } |
c0e0d6ba | 3673 | |
2b188cc1 | 3674 | if (flags & IORING_ENTER_GETEVENTS) { |
3e813c90 | 3675 | int ret2; |
c0e0d6ba | 3676 | |
773697b6 | 3677 | if (ctx->syscall_iopoll) { |
d487b43c PB |
3678 | /* |
3679 | * We disallow the app entering submit/complete with | |
3680 | * polling, but we still need to lock the ring to | |
3681 | * prevent racing with polled issue that got punted to | |
3682 | * a workqueue. | |
3683 | */ | |
3684 | mutex_lock(&ctx->uring_lock); | |
3685 | iopoll_locked: | |
3e813c90 DY |
3686 | ret2 = io_validate_ext_arg(flags, argp, argsz); |
3687 | if (likely(!ret2)) { | |
3688 | min_complete = min(min_complete, | |
3689 | ctx->cq_entries); | |
3690 | ret2 = io_iopoll_check(ctx, min_complete); | |
d487b43c PB |
3691 | } |
3692 | mutex_unlock(&ctx->uring_lock); | |
def596e9 | 3693 | } else { |
f81440d3 PB |
3694 | const sigset_t __user *sig; |
3695 | struct __kernel_timespec __user *ts; | |
3696 | ||
3e813c90 DY |
3697 | ret2 = io_get_ext_arg(flags, argp, &argsz, &ts, &sig); |
3698 | if (likely(!ret2)) { | |
3699 | min_complete = min(min_complete, | |
3700 | ctx->cq_entries); | |
3701 | ret2 = io_cqring_wait(ctx, min_complete, sig, | |
3702 | argsz, ts); | |
3703 | } | |
def596e9 | 3704 | } |
c73ebb68 | 3705 | |
155bc950 | 3706 | if (!ret) { |
3e813c90 | 3707 | ret = ret2; |
2b188cc1 | 3708 | |
155bc950 DY |
3709 | /* |
3710 | * EBADR indicates that one or more CQE were dropped. | |
3711 | * Once the user has been informed we can clear the bit | |
3712 | * as they are obviously ok with those drops. | |
3713 | */ | |
3714 | if (unlikely(ret2 == -EBADR)) | |
3715 | clear_bit(IO_CHECK_CQ_DROPPED_BIT, | |
3716 | &ctx->check_cq); | |
def596e9 | 3717 | } |
2b188cc1 | 3718 | } |
7c504e65 | 3719 | out: |
73363c26 JA |
3720 | if (!(flags & IORING_ENTER_REGISTERED_RING)) |
3721 | fput(file); | |
3e813c90 | 3722 | return ret; |
2b188cc1 JA |
3723 | } |
3724 | ||
3725 | static const struct file_operations io_uring_fops = { | |
3726 | .release = io_uring_release, | |
3727 | .mmap = io_uring_mmap, | |
6c5c240e RP |
3728 | #ifndef CONFIG_MMU |
3729 | .get_unmapped_area = io_uring_nommu_get_unmapped_area, | |
3730 | .mmap_capabilities = io_uring_nommu_mmap_capabilities, | |
d808459b HD |
3731 | #else |
3732 | .get_unmapped_area = io_uring_mmu_get_unmapped_area, | |
6c5c240e | 3733 | #endif |
2b188cc1 | 3734 | .poll = io_uring_poll, |
bebdb65e | 3735 | #ifdef CONFIG_PROC_FS |
87ce955b | 3736 | .show_fdinfo = io_uring_show_fdinfo, |
bebdb65e | 3737 | #endif |
2b188cc1 JA |
3738 | }; |
3739 | ||
92ac8bea JA |
3740 | bool io_is_uring_fops(struct file *file) |
3741 | { | |
3742 | return file->f_op == &io_uring_fops; | |
3743 | } | |
3744 | ||
c072481d PB |
3745 | static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx, |
3746 | struct io_uring_params *p) | |
2b188cc1 | 3747 | { |
75b28aff HV |
3748 | struct io_rings *rings; |
3749 | size_t size, sq_array_offset; | |
e27cef86 | 3750 | void *ptr; |
2b188cc1 | 3751 | |
bd740481 JA |
3752 | /* make sure these are sane, as we already accounted them */ |
3753 | ctx->sq_entries = p->sq_entries; | |
3754 | ctx->cq_entries = p->cq_entries; | |
3755 | ||
baf9cb64 | 3756 | size = rings_size(ctx, p->sq_entries, p->cq_entries, &sq_array_offset); |
75b28aff HV |
3757 | if (size == SIZE_MAX) |
3758 | return -EOVERFLOW; | |
3759 | ||
03d89a2d JA |
3760 | if (!(ctx->flags & IORING_SETUP_NO_MMAP)) |
3761 | rings = io_mem_alloc(size); | |
3762 | else | |
3763 | rings = io_rings_map(ctx, p->cq_off.user_addr, size); | |
3764 | ||
e27cef86 JA |
3765 | if (IS_ERR(rings)) |
3766 | return PTR_ERR(rings); | |
2b188cc1 | 3767 | |
75b28aff | 3768 | ctx->rings = rings; |
2af89abd PB |
3769 | if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) |
3770 | ctx->sq_array = (u32 *)((char *)rings + sq_array_offset); | |
75b28aff HV |
3771 | rings->sq_ring_mask = p->sq_entries - 1; |
3772 | rings->cq_ring_mask = p->cq_entries - 1; | |
3773 | rings->sq_ring_entries = p->sq_entries; | |
3774 | rings->cq_ring_entries = p->cq_entries; | |
2b188cc1 | 3775 | |
ebdeb7c0 JA |
3776 | if (p->flags & IORING_SETUP_SQE128) |
3777 | size = array_size(2 * sizeof(struct io_uring_sqe), p->sq_entries); | |
3778 | else | |
3779 | size = array_size(sizeof(struct io_uring_sqe), p->sq_entries); | |
eb065d30 | 3780 | if (size == SIZE_MAX) { |
9c189eee | 3781 | io_rings_free(ctx); |
2b188cc1 | 3782 | return -EOVERFLOW; |
eb065d30 | 3783 | } |
2b188cc1 | 3784 | |
03d89a2d JA |
3785 | if (!(ctx->flags & IORING_SETUP_NO_MMAP)) |
3786 | ptr = io_mem_alloc(size); | |
3787 | else | |
3788 | ptr = io_sqes_map(ctx, p->sq_off.user_addr, size); | |
3789 | ||
e27cef86 | 3790 | if (IS_ERR(ptr)) { |
9c189eee | 3791 | io_rings_free(ctx); |
e27cef86 | 3792 | return PTR_ERR(ptr); |
eb065d30 | 3793 | } |
2b188cc1 | 3794 | |
e27cef86 | 3795 | ctx->sq_sqes = ptr; |
2b188cc1 JA |
3796 | return 0; |
3797 | } | |
3798 | ||
6e76ac59 | 3799 | static int io_uring_install_fd(struct file *file) |
9faadcc8 | 3800 | { |
6e76ac59 | 3801 | int fd; |
9faadcc8 PB |
3802 | |
3803 | fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC); | |
3804 | if (fd < 0) | |
3805 | return fd; | |
9faadcc8 PB |
3806 | fd_install(fd, file); |
3807 | return fd; | |
3808 | } | |
3809 | ||
2b188cc1 JA |
3810 | /* |
3811 | * Allocate an anonymous fd, this is what constitutes the application | |
3812 | * visible backing of an io_uring instance. The application mmaps this | |
6e5e6d27 | 3813 | * fd to gain access to the SQ/CQ ring details. |
2b188cc1 | 3814 | */ |
9faadcc8 | 3815 | static struct file *io_uring_get_file(struct io_ring_ctx *ctx) |
2b188cc1 | 3816 | { |
4f0b9194 | 3817 | /* Create a new inode so that the LSM can block the creation. */ |
09d1c6a8 | 3818 | return anon_inode_create_getfile("[io_uring]", &io_uring_fops, ctx, |
91a9ab7c | 3819 | O_RDWR | O_CLOEXEC, NULL); |
2b188cc1 JA |
3820 | } |
3821 | ||
c072481d PB |
3822 | static __cold int io_uring_create(unsigned entries, struct io_uring_params *p, |
3823 | struct io_uring_params __user *params) | |
2b188cc1 | 3824 | { |
2b188cc1 | 3825 | struct io_ring_ctx *ctx; |
6e76ac59 | 3826 | struct io_uring_task *tctx; |
9faadcc8 | 3827 | struct file *file; |
2b188cc1 JA |
3828 | int ret; |
3829 | ||
8110c1a6 | 3830 | if (!entries) |
2b188cc1 | 3831 | return -EINVAL; |
8110c1a6 JA |
3832 | if (entries > IORING_MAX_ENTRIES) { |
3833 | if (!(p->flags & IORING_SETUP_CLAMP)) | |
3834 | return -EINVAL; | |
3835 | entries = IORING_MAX_ENTRIES; | |
3836 | } | |
2b188cc1 | 3837 | |
6e76ac59 JT |
3838 | if ((p->flags & IORING_SETUP_REGISTERED_FD_ONLY) |
3839 | && !(p->flags & IORING_SETUP_NO_MMAP)) | |
3840 | return -EINVAL; | |
3841 | ||
2b188cc1 JA |
3842 | /* |
3843 | * Use twice as many entries for the CQ ring. It's possible for the | |
3844 | * application to drive a higher depth than the size of the SQ ring, | |
3845 | * since the sqes are only used at submission time. This allows for | |
33a107f0 JA |
3846 | * some flexibility in overcommitting a bit. If the application has |
3847 | * set IORING_SETUP_CQSIZE, it will have passed in the desired number | |
3848 | * of CQ ring entries manually. | |
2b188cc1 JA |
3849 | */ |
3850 | p->sq_entries = roundup_pow_of_two(entries); | |
33a107f0 JA |
3851 | if (p->flags & IORING_SETUP_CQSIZE) { |
3852 | /* | |
3853 | * If IORING_SETUP_CQSIZE is set, we do the same roundup | |
3854 | * to a power-of-two, if it isn't already. We do NOT impose | |
3855 | * any cq vs sq ring sizing. | |
3856 | */ | |
eb2667b3 | 3857 | if (!p->cq_entries) |
33a107f0 | 3858 | return -EINVAL; |
8110c1a6 JA |
3859 | if (p->cq_entries > IORING_MAX_CQ_ENTRIES) { |
3860 | if (!(p->flags & IORING_SETUP_CLAMP)) | |
3861 | return -EINVAL; | |
3862 | p->cq_entries = IORING_MAX_CQ_ENTRIES; | |
3863 | } | |
eb2667b3 JQ |
3864 | p->cq_entries = roundup_pow_of_two(p->cq_entries); |
3865 | if (p->cq_entries < p->sq_entries) | |
3866 | return -EINVAL; | |
33a107f0 JA |
3867 | } else { |
3868 | p->cq_entries = 2 * p->sq_entries; | |
3869 | } | |
2b188cc1 | 3870 | |
2b188cc1 | 3871 | ctx = io_ring_ctx_alloc(p); |
62e398be | 3872 | if (!ctx) |
2b188cc1 | 3873 | return -ENOMEM; |
773697b6 | 3874 | |
e6aeb272 PB |
3875 | if ((ctx->flags & IORING_SETUP_DEFER_TASKRUN) && |
3876 | !(ctx->flags & IORING_SETUP_IOPOLL) && | |
3877 | !(ctx->flags & IORING_SETUP_SQPOLL)) | |
3878 | ctx->task_complete = true; | |
3879 | ||
ec26c225 PB |
3880 | if (ctx->task_complete || (ctx->flags & IORING_SETUP_IOPOLL)) |
3881 | ctx->lockless_cq = true; | |
3882 | ||
bca39f39 PB |
3883 | /* |
3884 | * lazy poll_wq activation relies on ->task_complete for synchronisation | |
3885 | * purposes, see io_activate_pollwq() | |
3886 | */ | |
3887 | if (!ctx->task_complete) | |
3888 | ctx->poll_activated = true; | |
3889 | ||
773697b6 PB |
3890 | /* |
3891 | * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user | |
3892 | * space applications don't need to do io completion events | |
3893 | * polling again, they can rely on io_sq_thread to do polling | |
3894 | * work, which can reduce cpu usage and uring_lock contention. | |
3895 | */ | |
3896 | if (ctx->flags & IORING_SETUP_IOPOLL && | |
3897 | !(ctx->flags & IORING_SETUP_SQPOLL)) | |
3898 | ctx->syscall_iopoll = 1; | |
3899 | ||
2b188cc1 | 3900 | ctx->compat = in_compat_syscall(); |
6adc2272 | 3901 | if (!ns_capable_noaudit(&init_user_ns, CAP_IPC_LOCK)) |
62e398be | 3902 | ctx->user = get_uid(current_user()); |
2aede0e4 | 3903 | |
9f010507 | 3904 | /* |
e1169f06 JA |
3905 | * For SQPOLL, we just need a wakeup, always. For !SQPOLL, if |
3906 | * COOP_TASKRUN is set, then IPIs are never needed by the app. | |
9f010507 | 3907 | */ |
e1169f06 JA |
3908 | ret = -EINVAL; |
3909 | if (ctx->flags & IORING_SETUP_SQPOLL) { | |
3910 | /* IPI related flags don't make sense with SQPOLL */ | |
ef060ea9 | 3911 | if (ctx->flags & (IORING_SETUP_COOP_TASKRUN | |
c0e0d6ba DY |
3912 | IORING_SETUP_TASKRUN_FLAG | |
3913 | IORING_SETUP_DEFER_TASKRUN)) | |
e1169f06 | 3914 | goto err; |
9f010507 | 3915 | ctx->notify_method = TWA_SIGNAL_NO_IPI; |
e1169f06 JA |
3916 | } else if (ctx->flags & IORING_SETUP_COOP_TASKRUN) { |
3917 | ctx->notify_method = TWA_SIGNAL_NO_IPI; | |
3918 | } else { | |
c0e0d6ba DY |
3919 | if (ctx->flags & IORING_SETUP_TASKRUN_FLAG && |
3920 | !(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) | |
ef060ea9 | 3921 | goto err; |
9f010507 | 3922 | ctx->notify_method = TWA_SIGNAL; |
e1169f06 | 3923 | } |
9f010507 | 3924 | |
c0e0d6ba DY |
3925 | /* |
3926 | * For DEFER_TASKRUN we require the completion task to be the same as the | |
3927 | * submission task. This implies that there is only one submitter, so enforce | |
3928 | * that. | |
3929 | */ | |
3930 | if (ctx->flags & IORING_SETUP_DEFER_TASKRUN && | |
3931 | !(ctx->flags & IORING_SETUP_SINGLE_ISSUER)) { | |
3932 | goto err; | |
3933 | } | |
3934 | ||
2aede0e4 JA |
3935 | /* |
3936 | * This is just grabbed for accounting purposes. When a process exits, | |
3937 | * the mm is exited and dropped before the files, hence we need to hang | |
3938 | * on to this mm purely for the purposes of being able to unaccount | |
3939 | * memory (locked/pinned vm). It's not used for anything else. | |
3940 | */ | |
6b7898eb | 3941 | mmgrab(current->mm); |
2aede0e4 | 3942 | ctx->mm_account = current->mm; |
6b7898eb | 3943 | |
2b188cc1 JA |
3944 | ret = io_allocate_scq_urings(ctx, p); |
3945 | if (ret) | |
3946 | goto err; | |
3947 | ||
7e84e1c7 | 3948 | ret = io_sq_offload_create(ctx, p); |
2b188cc1 JA |
3949 | if (ret) |
3950 | goto err; | |
2933ae6e PB |
3951 | |
3952 | ret = io_rsrc_init(ctx); | |
47b228ce PB |
3953 | if (ret) |
3954 | goto err; | |
2b188cc1 | 3955 | |
75b28aff HV |
3956 | p->sq_off.head = offsetof(struct io_rings, sq.head); |
3957 | p->sq_off.tail = offsetof(struct io_rings, sq.tail); | |
3958 | p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask); | |
3959 | p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries); | |
3960 | p->sq_off.flags = offsetof(struct io_rings, sq_flags); | |
3961 | p->sq_off.dropped = offsetof(struct io_rings, sq_dropped); | |
2af89abd PB |
3962 | if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) |
3963 | p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings; | |
9b1b58ca | 3964 | p->sq_off.resv1 = 0; |
03d89a2d JA |
3965 | if (!(ctx->flags & IORING_SETUP_NO_MMAP)) |
3966 | p->sq_off.user_addr = 0; | |
2b188cc1 | 3967 | |
75b28aff HV |
3968 | p->cq_off.head = offsetof(struct io_rings, cq.head); |
3969 | p->cq_off.tail = offsetof(struct io_rings, cq.tail); | |
3970 | p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask); | |
3971 | p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries); | |
3972 | p->cq_off.overflow = offsetof(struct io_rings, cq_overflow); | |
3973 | p->cq_off.cqes = offsetof(struct io_rings, cqes); | |
0d9b5b3a | 3974 | p->cq_off.flags = offsetof(struct io_rings, cq_flags); |
9b1b58ca | 3975 | p->cq_off.resv1 = 0; |
03d89a2d JA |
3976 | if (!(ctx->flags & IORING_SETUP_NO_MMAP)) |
3977 | p->cq_off.user_addr = 0; | |
ac90f249 | 3978 | |
7f13657d XW |
3979 | p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP | |
3980 | IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS | | |
5769a351 | 3981 | IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL | |
c73ebb68 | 3982 | IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED | |
9690557e | 3983 | IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS | |
c4212f3e | 3984 | IORING_FEAT_RSRC_TAGS | IORING_FEAT_CQE_SKIP | |
7d3fd88d | 3985 | IORING_FEAT_LINKED_FILE | IORING_FEAT_REG_REG_RING; |
7f13657d XW |
3986 | |
3987 | if (copy_to_user(params, p, sizeof(*p))) { | |
3988 | ret = -EFAULT; | |
3989 | goto err; | |
3990 | } | |
d1719f70 | 3991 | |
7cae596b DY |
3992 | if (ctx->flags & IORING_SETUP_SINGLE_ISSUER |
3993 | && !(ctx->flags & IORING_SETUP_R_DISABLED)) | |
8579538c | 3994 | WRITE_ONCE(ctx->submitter_task, get_task_struct(current)); |
7cae596b | 3995 | |
9faadcc8 PB |
3996 | file = io_uring_get_file(ctx); |
3997 | if (IS_ERR(file)) { | |
3998 | ret = PTR_ERR(file); | |
3999 | goto err; | |
4000 | } | |
4001 | ||
6e76ac59 JT |
4002 | ret = __io_uring_add_tctx_node(ctx); |
4003 | if (ret) | |
4004 | goto err_fput; | |
4005 | tctx = current->io_uring; | |
4006 | ||
044c1ab3 JA |
4007 | /* |
4008 | * Install ring fd as the very last thing, so we don't risk someone | |
4009 | * having closed it before we finish setup | |
4010 | */ | |
6e76ac59 JT |
4011 | if (p->flags & IORING_SETUP_REGISTERED_FD_ONLY) |
4012 | ret = io_ring_add_registered_file(tctx, file, 0, IO_RINGFD_REG_MAX); | |
4013 | else | |
4014 | ret = io_uring_install_fd(file); | |
4015 | if (ret < 0) | |
4016 | goto err_fput; | |
044c1ab3 | 4017 | |
c826bd7a | 4018 | trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags); |
2b188cc1 JA |
4019 | return ret; |
4020 | err: | |
4021 | io_ring_ctx_wait_and_kill(ctx); | |
4022 | return ret; | |
6e76ac59 JT |
4023 | err_fput: |
4024 | fput(file); | |
4025 | return ret; | |
2b188cc1 JA |
4026 | } |
4027 | ||
4028 | /* | |
4029 | * Sets up an aio uring context, and returns the fd. Applications asks for a | |
4030 | * ring size, we return the actual sq/cq ring sizes (among other things) in the | |
4031 | * params structure passed in. | |
4032 | */ | |
4033 | static long io_uring_setup(u32 entries, struct io_uring_params __user *params) | |
4034 | { | |
4035 | struct io_uring_params p; | |
2b188cc1 JA |
4036 | int i; |
4037 | ||
4038 | if (copy_from_user(&p, params, sizeof(p))) | |
4039 | return -EFAULT; | |
4040 | for (i = 0; i < ARRAY_SIZE(p.resv); i++) { | |
4041 | if (p.resv[i]) | |
4042 | return -EINVAL; | |
4043 | } | |
4044 | ||
6c271ce2 | 4045 | if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL | |
8110c1a6 | 4046 | IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE | |
7e84e1c7 | 4047 | IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ | |
e1169f06 | 4048 | IORING_SETUP_R_DISABLED | IORING_SETUP_SUBMIT_ALL | |
ebdeb7c0 | 4049 | IORING_SETUP_COOP_TASKRUN | IORING_SETUP_TASKRUN_FLAG | |
97bbdc06 | 4050 | IORING_SETUP_SQE128 | IORING_SETUP_CQE32 | |
03d89a2d | 4051 | IORING_SETUP_SINGLE_ISSUER | IORING_SETUP_DEFER_TASKRUN | |
2af89abd PB |
4052 | IORING_SETUP_NO_MMAP | IORING_SETUP_REGISTERED_FD_ONLY | |
4053 | IORING_SETUP_NO_SQARRAY)) | |
2b188cc1 JA |
4054 | return -EINVAL; |
4055 | ||
ef060ea9 | 4056 | return io_uring_create(entries, &p, params); |
2b188cc1 JA |
4057 | } |
4058 | ||
76d3ccec MR |
4059 | static inline bool io_uring_allowed(void) |
4060 | { | |
4061 | int disabled = READ_ONCE(sysctl_io_uring_disabled); | |
4062 | kgid_t io_uring_group; | |
4063 | ||
4064 | if (disabled == 2) | |
4065 | return false; | |
4066 | ||
4067 | if (disabled == 0 || capable(CAP_SYS_ADMIN)) | |
4068 | return true; | |
4069 | ||
4070 | io_uring_group = make_kgid(&init_user_ns, sysctl_io_uring_group); | |
4071 | if (!gid_valid(io_uring_group)) | |
4072 | return false; | |
4073 | ||
4074 | return in_group_p(io_uring_group); | |
4075 | } | |
4076 | ||
2b188cc1 JA |
4077 | SYSCALL_DEFINE2(io_uring_setup, u32, entries, |
4078 | struct io_uring_params __user *, params) | |
4079 | { | |
76d3ccec MR |
4080 | if (!io_uring_allowed()) |
4081 | return -EPERM; | |
4082 | ||
2b188cc1 JA |
4083 | return io_uring_setup(entries, params); |
4084 | } | |
4085 | ||
4086 | static int __init io_uring_init(void) | |
4087 | { | |
9c71d39a | 4088 | #define __BUILD_BUG_VERIFY_OFFSET_SIZE(stype, eoffset, esize, ename) do { \ |
d7f62e82 | 4089 | BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \ |
9c71d39a | 4090 | BUILD_BUG_ON(sizeof_field(stype, ename) != esize); \ |
d7f62e82 SM |
4091 | } while (0) |
4092 | ||
4093 | #define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \ | |
9c71d39a SM |
4094 | __BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, sizeof(etype), ename) |
4095 | #define BUILD_BUG_SQE_ELEM_SIZE(eoffset, esize, ename) \ | |
4096 | __BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, esize, ename) | |
d7f62e82 SM |
4097 | BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64); |
4098 | BUILD_BUG_SQE_ELEM(0, __u8, opcode); | |
4099 | BUILD_BUG_SQE_ELEM(1, __u8, flags); | |
4100 | BUILD_BUG_SQE_ELEM(2, __u16, ioprio); | |
4101 | BUILD_BUG_SQE_ELEM(4, __s32, fd); | |
4102 | BUILD_BUG_SQE_ELEM(8, __u64, off); | |
4103 | BUILD_BUG_SQE_ELEM(8, __u64, addr2); | |
9c71d39a SM |
4104 | BUILD_BUG_SQE_ELEM(8, __u32, cmd_op); |
4105 | BUILD_BUG_SQE_ELEM(12, __u32, __pad1); | |
d7f62e82 | 4106 | BUILD_BUG_SQE_ELEM(16, __u64, addr); |
7d67af2c | 4107 | BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in); |
d7f62e82 SM |
4108 | BUILD_BUG_SQE_ELEM(24, __u32, len); |
4109 | BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags); | |
4110 | BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags); | |
4111 | BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags); | |
4112 | BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags); | |
5769a351 JX |
4113 | BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events); |
4114 | BUILD_BUG_SQE_ELEM(28, __u32, poll32_events); | |
d7f62e82 SM |
4115 | BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags); |
4116 | BUILD_BUG_SQE_ELEM(28, __u32, msg_flags); | |
4117 | BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags); | |
4118 | BUILD_BUG_SQE_ELEM(28, __u32, accept_flags); | |
4119 | BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags); | |
4120 | BUILD_BUG_SQE_ELEM(28, __u32, open_flags); | |
4121 | BUILD_BUG_SQE_ELEM(28, __u32, statx_flags); | |
4122 | BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice); | |
7d67af2c | 4123 | BUILD_BUG_SQE_ELEM(28, __u32, splice_flags); |
9c71d39a SM |
4124 | BUILD_BUG_SQE_ELEM(28, __u32, rename_flags); |
4125 | BUILD_BUG_SQE_ELEM(28, __u32, unlink_flags); | |
4126 | BUILD_BUG_SQE_ELEM(28, __u32, hardlink_flags); | |
4127 | BUILD_BUG_SQE_ELEM(28, __u32, xattr_flags); | |
4128 | BUILD_BUG_SQE_ELEM(28, __u32, msg_ring_flags); | |
d7f62e82 SM |
4129 | BUILD_BUG_SQE_ELEM(32, __u64, user_data); |
4130 | BUILD_BUG_SQE_ELEM(40, __u16, buf_index); | |
16340eab | 4131 | BUILD_BUG_SQE_ELEM(40, __u16, buf_group); |
d7f62e82 | 4132 | BUILD_BUG_SQE_ELEM(42, __u16, personality); |
7d67af2c | 4133 | BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in); |
b9445598 | 4134 | BUILD_BUG_SQE_ELEM(44, __u32, file_index); |
b48c312b PB |
4135 | BUILD_BUG_SQE_ELEM(44, __u16, addr_len); |
4136 | BUILD_BUG_SQE_ELEM(46, __u16, __pad3[0]); | |
e9621e2b | 4137 | BUILD_BUG_SQE_ELEM(48, __u64, addr3); |
9c71d39a SM |
4138 | BUILD_BUG_SQE_ELEM_SIZE(48, 0, cmd); |
4139 | BUILD_BUG_SQE_ELEM(56, __u64, __pad2); | |
d7f62e82 | 4140 | |
b0d658ec PB |
4141 | BUILD_BUG_ON(sizeof(struct io_uring_files_update) != |
4142 | sizeof(struct io_uring_rsrc_update)); | |
4143 | BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) > | |
4144 | sizeof(struct io_uring_rsrc_update2)); | |
90499ad0 PB |
4145 | |
4146 | /* ->buf_index is u16 */ | |
c7fb1942 JA |
4147 | BUILD_BUG_ON(offsetof(struct io_uring_buf_ring, bufs) != 0); |
4148 | BUILD_BUG_ON(offsetof(struct io_uring_buf, resv) != | |
4149 | offsetof(struct io_uring_buf_ring, tail)); | |
90499ad0 | 4150 | |
b0d658ec PB |
4151 | /* should fit into one byte */ |
4152 | BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8)); | |
68fe256a PB |
4153 | BUILD_BUG_ON(SQE_COMMON_FLAGS >= (1 << 8)); |
4154 | BUILD_BUG_ON((SQE_VALID_FLAGS | SQE_COMMON_FLAGS) != SQE_VALID_FLAGS); | |
b0d658ec | 4155 | |
32c2d33e | 4156 | BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof(int)); |
16340eab | 4157 | |
3a4b89a2 JA |
4158 | BUILD_BUG_ON(sizeof(atomic_t) != sizeof(u32)); |
4159 | ||
528ce678 ML |
4160 | /* top 8bits are for internal use */ |
4161 | BUILD_BUG_ON((IORING_URING_CMD_MASK & 0xff000000) != 0); | |
4162 | ||
d9b57aa3 | 4163 | io_uring_optable_init(); |
0702e536 | 4164 | |
b97f96e2 JA |
4165 | /* |
4166 | * Allow user copy in the per-command field, which starts after the | |
4167 | * file in io_kiocb and until the opcode field. The openat2 handling | |
4168 | * requires copying in user memory into the io_kiocb object in that | |
4169 | * range, and HARDENED_USERCOPY will complain if we haven't | |
4170 | * correctly annotated this range. | |
4171 | */ | |
4172 | req_cachep = kmem_cache_create_usercopy("io_kiocb", | |
4173 | sizeof(struct io_kiocb), 0, | |
4174 | SLAB_HWCACHE_ALIGN | SLAB_PANIC | | |
4175 | SLAB_ACCOUNT | SLAB_TYPESAFE_BY_RCU, | |
4176 | offsetof(struct io_kiocb, cmd.data), | |
4177 | sizeof_field(struct io_kiocb, cmd.data), NULL); | |
b3a4dbc8 GKB |
4178 | io_buf_cachep = kmem_cache_create("io_buffer", sizeof(struct io_buffer), 0, |
4179 | SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT, | |
4180 | NULL); | |
b97f96e2 | 4181 | |
76d3ccec MR |
4182 | #ifdef CONFIG_SYSCTL |
4183 | register_sysctl_init("kernel", kernel_io_uring_disabled_table); | |
4184 | #endif | |
4185 | ||
2b188cc1 JA |
4186 | return 0; |
4187 | }; | |
4188 | __initcall(io_uring_init); |