1 #ifndef IO_URING_TYPES_H
2 #define IO_URING_TYPES_H
3
4 #include <linux/blkdev.h>
5 #include <linux/task_work.h>
6 #include <linux/bitmap.h>
7 #include <linux/llist.h>
8 #include <uapi/linux/io_uring.h>
9
10 struct io_wq_work_node {
11 struct io_wq_work_node *next;
12 };
13
14 struct io_wq_work_list {
15 struct io_wq_work_node *first;
16 struct io_wq_work_node *last;
17 };
18
19 struct io_wq_work {
20 struct io_wq_work_node list;
21 unsigned flags;
22 /* place it here instead of io_kiocb as it fills padding and saves 4B */
23 int cancel_seq;
24 };
25
26 struct io_fixed_file {
27 /* file * with additional FFS_* flags */
28 unsigned long file_ptr;
29 };
30
31 struct io_file_table {
32 struct io_fixed_file *files;
33 unsigned long *bitmap;
34 unsigned int alloc_hint;
35 };
36
37 struct io_hash_bucket {
38 spinlock_t lock;
39 struct hlist_head list;
40 } ____cacheline_aligned_in_smp;
41
42 struct io_hash_table {
43 struct io_hash_bucket *hbs;
44 unsigned hash_bits;
45 };
46
47 /*
48 * Arbitrary limit, can be raised if need be
49 */
50 #define IO_RINGFD_REG_MAX 16
51
52 struct io_uring_task {
53 /* submission side */
54 int cached_refs;
55 const struct io_ring_ctx *last;
56 struct io_wq *io_wq;
57 struct file *registered_rings[IO_RINGFD_REG_MAX];
58
59 struct xarray xa;
60 struct wait_queue_head wait;
61 atomic_t in_idle;
62 atomic_t inflight_tracked;
63 struct percpu_counter inflight;
64
65 struct { /* task_work */
66 struct llist_head task_list;
67 struct callback_head task_work;
68 } ____cacheline_aligned_in_smp;
69 };
70
71 struct io_uring {
72 u32 head ____cacheline_aligned_in_smp;
73 u32 tail ____cacheline_aligned_in_smp;
74 };
75
76 /*
77 * This data is shared with the application through the mmap at offsets
78 * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
79 *
80 * The offsets to the member fields are published through struct
81 * io_sqring_offsets when calling io_uring_setup.
82 */
83 struct io_rings {
84 /*
85 * Head and tail offsets into the ring; the offsets need to be
86 * masked to get valid indices.
87 *
88 * The kernel controls head of the sq ring and the tail of the cq ring,
89 * and the application controls tail of the sq ring and the head of the
90 * cq ring.
91 */
92 struct io_uring sq, cq;
93 /*
94 * Bitmasks to apply to head and tail offsets (constant, equals
95 * ring_entries - 1)
96 */
97 u32 sq_ring_mask, cq_ring_mask;
98 /* Ring sizes (constant, power of 2) */
99 u32 sq_ring_entries, cq_ring_entries;
100 /*
101 * Number of invalid entries dropped by the kernel due to
102 * invalid index stored in array
103 *
104 * Written by the kernel, shouldn't be modified by the
105 * application (i.e. get number of "new events" by comparing to
106 * cached value).
107 *
108 * After a new SQ head value was read by the application this
109 * counter includes all submissions that were dropped reaching
110 * the new SQ head (and possibly more).
111 */
112 u32 sq_dropped;
113 /*
114 * Runtime SQ flags
115 *
116 * Written by the kernel, shouldn't be modified by the
117 * application.
118 *
119 * The application needs a full memory barrier before checking
120 * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
121 */
122 atomic_t sq_flags;
123 /*
124 * Runtime CQ flags
125 *
126 * Written by the application, shouldn't be modified by the
127 * kernel.
128 */
129 u32 cq_flags;
130 /*
131 * Number of completion events lost because the queue was full;
132 * this should be avoided by the application by making sure
133 * there are not more requests pending than there is space in
134 * the completion queue.
135 *
136 * Written by the kernel, shouldn't be modified by the
137 * application (i.e. get number of "new events" by comparing to
138 * cached value).
139 *
140 * As completion events come in out of order this counter is not
141 * ordered with any other data.
142 */
143 u32 cq_overflow;
144 /*
145 * Ring buffer of completion events.
146 *
147 * The kernel writes completion events fresh every time they are
148 * produced, so the application is allowed to modify pending
149 * entries.
150 */
151 struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
152 };
153
154 struct io_restriction {
155 DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
156 DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
157 u8 sqe_flags_allowed;
158 u8 sqe_flags_required;
159 bool registered;
160 };
161
162 struct io_submit_link {
163 struct io_kiocb *head;
164 struct io_kiocb *last;
165 };
166
167 struct io_submit_state {
168 /* inline/task_work completion list, under ->uring_lock */
169 struct io_wq_work_node free_list;
170 /* batch completion logic */
171 struct io_wq_work_list compl_reqs;
172 struct io_submit_link link;
173
174 bool plug_started;
175 bool need_plug;
176 unsigned short submit_nr;
177 struct blk_plug plug;
178 };
179
180 struct io_ev_fd {
181 struct eventfd_ctx *cq_ev_fd;
182 unsigned int eventfd_async: 1;
183 struct rcu_head rcu;
184 atomic_t refs;
185 atomic_t ops;
186 };
187
188 struct io_alloc_cache {
189 struct hlist_head list;
190 unsigned int nr_cached;
191 };
192
193 struct io_ring_ctx {
194 /* const or read-mostly hot data */
195 struct {
196 struct percpu_ref refs;
197
198 struct io_rings *rings;
199 unsigned int flags;
200 enum task_work_notify_mode notify_method;
201 unsigned int compat: 1;
202 unsigned int drain_next: 1;
203 unsigned int restricted: 1;
204 unsigned int off_timeout_used: 1;
205 unsigned int drain_active: 1;
206 unsigned int drain_disabled: 1;
207 unsigned int has_evfd: 1;
208 unsigned int syscall_iopoll: 1;
209 } ____cacheline_aligned_in_smp;
210
211 /* submission data */
212 struct {
213 struct mutex uring_lock;
214
215 /*
216 * Ring buffer of indices into array of io_uring_sqe, which is
217 * mmapped by the application using the IORING_OFF_SQES offset.
218 *
219 * This indirection could e.g. be used to assign fixed
220 * io_uring_sqe entries to operations and only submit them to
221 * the queue when needed.
222 *
223 * The kernel modifies neither the indices array nor the entries
224 * array.
225 */
226 u32 *sq_array;
227 struct io_uring_sqe *sq_sqes;
228 unsigned cached_sq_head;
229 unsigned sq_entries;
230
231 /*
232 * Fixed resources fast path, should be accessed only under
233 * uring_lock, and updated through io_uring_register(2)
234 */
235 struct io_rsrc_node *rsrc_node;
236 int rsrc_cached_refs;
237 atomic_t cancel_seq;
238 struct io_file_table file_table;
239 unsigned nr_user_files;
240 unsigned nr_user_bufs;
241 struct io_mapped_ubuf **user_bufs;
242
243 struct io_submit_state submit_state;
244
245 struct io_buffer_list *io_bl;
246 struct xarray io_bl_xa;
247 struct list_head io_buffers_cache;
248
249 struct io_hash_table cancel_table_locked;
250 struct list_head cq_overflow_list;
251 struct io_alloc_cache apoll_cache;
252 struct io_alloc_cache netmsg_cache;
253 } ____cacheline_aligned_in_smp;
254
255 /* IRQ completion list, under ->completion_lock */
256 struct io_wq_work_list locked_free_list;
257 unsigned int locked_free_nr;
258
259 const struct cred *sq_creds; /* cred used for __io_sq_thread() */
260 struct io_sq_data *sq_data; /* if using sq thread polling */
261
262 struct wait_queue_head sqo_sq_wait;
263 struct list_head sqd_list;
264
265 unsigned long check_cq;
266
267 unsigned int file_alloc_start;
268 unsigned int file_alloc_end;
269
270 struct xarray personalities;
271 u32 pers_next;
272
273 struct {
274 /*
275 * We cache a range of free CQEs we can use, once exhausted it
276 * should go through a slower range setup, see __io_get_cqe()
277 */
278 struct io_uring_cqe *cqe_cached;
279 struct io_uring_cqe *cqe_sentinel;
280
281 unsigned cached_cq_tail;
282 unsigned cq_entries;
283 struct io_ev_fd __rcu *io_ev_fd;
284 struct wait_queue_head cq_wait;
285 unsigned cq_extra;
286 } ____cacheline_aligned_in_smp;
287
288 struct {
289 spinlock_t completion_lock;
290
291 /*
292 * ->iopoll_list is protected by the ctx->uring_lock for
293 * io_uring instances that don't use IORING_SETUP_SQPOLL.
294 * For SQPOLL, only the single threaded io_sq_thread() will
295 * manipulate the list, hence no extra locking is needed there.
296 */
297 struct io_wq_work_list iopoll_list;
298 struct io_hash_table cancel_table;
299 bool poll_multi_queue;
300
301 struct llist_head work_llist;
302
303 struct list_head io_buffers_comp;
304 } ____cacheline_aligned_in_smp;
305
306 /* timeouts */
307 struct {
308 spinlock_t timeout_lock;
309 atomic_t cq_timeouts;
310 struct list_head timeout_list;
311 struct list_head ltimeout_list;
312 unsigned cq_last_tm_flush;
313 } ____cacheline_aligned_in_smp;
314
315 /* Keep this last, we don't need it for the fast path */
316
317 struct io_restriction restrictions;
318 struct task_struct *submitter_task;
319
320 /* slow path rsrc auxilary data, used by update/register */
321 struct io_rsrc_node *rsrc_backup_node;
322 struct io_mapped_ubuf *dummy_ubuf;
323 struct io_rsrc_data *file_data;
324 struct io_rsrc_data *buf_data;
325
326 struct delayed_work rsrc_put_work;
327 struct llist_head rsrc_put_llist;
328 struct list_head rsrc_ref_list;
329 spinlock_t rsrc_ref_lock;
330
331 struct list_head io_buffers_pages;
332
333 #if defined(CONFIG_UNIX)
334 struct socket *ring_sock;
335 #endif
336 /* hashed buffered write serialization */
337 struct io_wq_hash *hash_map;
338
339 /* Only used for accounting purposes */
340 struct user_struct *user;
341 struct mm_struct *mm_account;
342
343 /* ctx exit and cancelation */
344 struct llist_head fallback_llist;
345 struct delayed_work fallback_work;
346 struct work_struct exit_work;
347 struct list_head tctx_list;
348 struct completion ref_comp;
349
350 /* io-wq management, e.g. thread count */
351 u32 iowq_limits[2];
352 bool iowq_limits_set;
353
354 struct list_head defer_list;
355 unsigned sq_thread_idle;
356 /* protected by ->completion_lock */
357 unsigned evfd_last_cq_tail;
358 };
359
360 enum {
361 REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
362 REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
363 REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
364 REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
365 REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
366 REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
367 REQ_F_CQE_SKIP_BIT = IOSQE_CQE_SKIP_SUCCESS_BIT,
368
369 /* first byte is taken by user flags, shift it to not overlap */
370 REQ_F_FAIL_BIT = 8,
371 REQ_F_INFLIGHT_BIT,
372 REQ_F_CUR_POS_BIT,
373 REQ_F_NOWAIT_BIT,
374 REQ_F_LINK_TIMEOUT_BIT,
375 REQ_F_NEED_CLEANUP_BIT,
376 REQ_F_POLLED_BIT,
377 REQ_F_BUFFER_SELECTED_BIT,
378 REQ_F_BUFFER_RING_BIT,
379 REQ_F_REISSUE_BIT,
380 REQ_F_CREDS_BIT,
381 REQ_F_REFCOUNT_BIT,
382 REQ_F_ARM_LTIMEOUT_BIT,
383 REQ_F_ASYNC_DATA_BIT,
384 REQ_F_SKIP_LINK_CQES_BIT,
385 REQ_F_SINGLE_POLL_BIT,
386 REQ_F_DOUBLE_POLL_BIT,
387 REQ_F_PARTIAL_IO_BIT,
388 REQ_F_CQE32_INIT_BIT,
389 REQ_F_APOLL_MULTISHOT_BIT,
390 REQ_F_CLEAR_POLLIN_BIT,
391 REQ_F_HASH_LOCKED_BIT,
392 /* keep async read/write and isreg together and in order */
393 REQ_F_SUPPORT_NOWAIT_BIT,
394 REQ_F_ISREG_BIT,
395
396 /* not a real bit, just to check we're not overflowing the space */
397 __REQ_F_LAST_BIT,
398 };
399
400 enum {
401 /* ctx owns file */
402 REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
403 /* drain existing IO first */
404 REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
405 /* linked sqes */
406 REQ_F_LINK = BIT(REQ_F_LINK_BIT),
407 /* doesn't sever on completion < 0 */
408 REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
409 /* IOSQE_ASYNC */
410 REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
411 /* IOSQE_BUFFER_SELECT */
412 REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
413 /* IOSQE_CQE_SKIP_SUCCESS */
414 REQ_F_CQE_SKIP = BIT(REQ_F_CQE_SKIP_BIT),
415
416 /* fail rest of links */
417 REQ_F_FAIL = BIT(REQ_F_FAIL_BIT),
418 /* on inflight list, should be cancelled and waited on exit reliably */
419 REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
420 /* read/write uses file position */
421 REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
422 /* must not punt to workers */
423 REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
424 /* has or had linked timeout */
425 REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
426 /* needs cleanup */
427 REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
428 /* already went through poll handler */
429 REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
430 /* buffer already selected */
431 REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
432 /* buffer selected from ring, needs commit */
433 REQ_F_BUFFER_RING = BIT(REQ_F_BUFFER_RING_BIT),
434 /* caller should reissue async */
435 REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT),
436 /* supports async reads/writes */
437 REQ_F_SUPPORT_NOWAIT = BIT(REQ_F_SUPPORT_NOWAIT_BIT),
438 /* regular file */
439 REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
440 /* has creds assigned */
441 REQ_F_CREDS = BIT(REQ_F_CREDS_BIT),
442 /* skip refcounting if not set */
443 REQ_F_REFCOUNT = BIT(REQ_F_REFCOUNT_BIT),
444 /* there is a linked timeout that has to be armed */
445 REQ_F_ARM_LTIMEOUT = BIT(REQ_F_ARM_LTIMEOUT_BIT),
446 /* ->async_data allocated */
447 REQ_F_ASYNC_DATA = BIT(REQ_F_ASYNC_DATA_BIT),
448 /* don't post CQEs while failing linked requests */
449 REQ_F_SKIP_LINK_CQES = BIT(REQ_F_SKIP_LINK_CQES_BIT),
450 /* single poll may be active */
451 REQ_F_SINGLE_POLL = BIT(REQ_F_SINGLE_POLL_BIT),
452 /* double poll may active */
453 REQ_F_DOUBLE_POLL = BIT(REQ_F_DOUBLE_POLL_BIT),
454 /* request has already done partial IO */
455 REQ_F_PARTIAL_IO = BIT(REQ_F_PARTIAL_IO_BIT),
456 /* fast poll multishot mode */
457 REQ_F_APOLL_MULTISHOT = BIT(REQ_F_APOLL_MULTISHOT_BIT),
458 /* ->extra1 and ->extra2 are initialised */
459 REQ_F_CQE32_INIT = BIT(REQ_F_CQE32_INIT_BIT),
460 /* recvmsg special flag, clear EPOLLIN */
461 REQ_F_CLEAR_POLLIN = BIT(REQ_F_CLEAR_POLLIN_BIT),
462 /* hashed into ->cancel_hash_locked, protected by ->uring_lock */
463 REQ_F_HASH_LOCKED = BIT(REQ_F_HASH_LOCKED_BIT),
464 };
465
466 typedef void (*io_req_tw_func_t)(struct io_kiocb *req, bool *locked);
467
468 struct io_task_work {
469 struct llist_node node;
470 io_req_tw_func_t func;
471 };
472
473 struct io_cqe {
474 __u64 user_data;
475 __s32 res;
476 /* fd initially, then cflags for completion */
477 union {
478 __u32 flags;
479 int fd;
480 };
481 };
482
483 /*
484 * Each request type overlays its private data structure on top of this one.
485 * They must not exceed this one in size.
486 */
487 struct io_cmd_data {
488 struct file *file;
489 /* each command gets 56 bytes of data */
490 __u8 data[56];
491 };
492
io_kiocb_cmd_sz_check(size_t cmd_sz)493 static inline void io_kiocb_cmd_sz_check(size_t cmd_sz)
494 {
495 BUILD_BUG_ON(cmd_sz > sizeof(struct io_cmd_data));
496 }
497 #define io_kiocb_to_cmd(req, cmd_type) ( \
498 io_kiocb_cmd_sz_check(sizeof(cmd_type)) , \
499 ((cmd_type *)&(req)->cmd) \
500 )
501 #define cmd_to_io_kiocb(ptr) ((struct io_kiocb *) ptr)
502
503 struct io_kiocb {
504 union {
505 /*
506 * NOTE! Each of the io_kiocb union members has the file pointer
507 * as the first entry in their struct definition. So you can
508 * access the file pointer through any of the sub-structs,
509 * or directly as just 'file' in this struct.
510 */
511 struct file *file;
512 struct io_cmd_data cmd;
513 };
514
515 u8 opcode;
516 /* polled IO has completed */
517 u8 iopoll_completed;
518 /*
519 * Can be either a fixed buffer index, or used with provided buffers.
520 * For the latter, before issue it points to the buffer group ID,
521 * and after selection it points to the buffer ID itself.
522 */
523 u16 buf_index;
524 unsigned int flags;
525
526 struct io_cqe cqe;
527
528 struct io_ring_ctx *ctx;
529 struct task_struct *task;
530
531 struct io_rsrc_node *rsrc_node;
532
533 union {
534 /* store used ubuf, so we can prevent reloading */
535 struct io_mapped_ubuf *imu;
536
537 /* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */
538 struct io_buffer *kbuf;
539
540 /*
541 * stores buffer ID for ring provided buffers, valid IFF
542 * REQ_F_BUFFER_RING is set.
543 */
544 struct io_buffer_list *buf_list;
545 };
546
547 union {
548 /* used by request caches, completion batching and iopoll */
549 struct io_wq_work_node comp_list;
550 /* cache ->apoll->events */
551 __poll_t apoll_events;
552 };
553 atomic_t refs;
554 atomic_t poll_refs;
555 struct io_task_work io_task_work;
556 /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
557 union {
558 struct hlist_node hash_node;
559 struct {
560 u64 extra1;
561 u64 extra2;
562 };
563 };
564 /* internal polling, see IORING_FEAT_FAST_POLL */
565 struct async_poll *apoll;
566 /* opcode allocated if it needs to store data for async defer */
567 void *async_data;
568 /* linked requests, IFF REQ_F_HARDLINK or REQ_F_LINK are set */
569 struct io_kiocb *link;
570 /* custom credentials, valid IFF REQ_F_CREDS is set */
571 const struct cred *creds;
572 struct io_wq_work work;
573 };
574
575 struct io_overflow_cqe {
576 struct list_head list;
577 struct io_uring_cqe cqe;
578 };
579
580 #endif
581