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71f28f31 ML |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * Userspace block device - block device which IO is handled from userspace | |
4 | * | |
5 | * Take full use of io_uring passthrough command for communicating with | |
6 | * ublk userspace daemon(ublksrvd) for handling basic IO request. | |
7 | * | |
8 | * Copyright 2022 Ming Lei <ming.lei@redhat.com> | |
9 | * | |
10 | * (part of code stolen from loop.c) | |
11 | */ | |
12 | #include <linux/module.h> | |
13 | #include <linux/moduleparam.h> | |
14 | #include <linux/sched.h> | |
15 | #include <linux/fs.h> | |
16 | #include <linux/pagemap.h> | |
17 | #include <linux/file.h> | |
18 | #include <linux/stat.h> | |
19 | #include <linux/errno.h> | |
20 | #include <linux/major.h> | |
21 | #include <linux/wait.h> | |
22 | #include <linux/blkdev.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/swap.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/compat.h> | |
27 | #include <linux/mutex.h> | |
28 | #include <linux/writeback.h> | |
29 | #include <linux/completion.h> | |
30 | #include <linux/highmem.h> | |
31 | #include <linux/sysfs.h> | |
32 | #include <linux/miscdevice.h> | |
33 | #include <linux/falloc.h> | |
34 | #include <linux/uio.h> | |
35 | #include <linux/ioprio.h> | |
36 | #include <linux/sched/mm.h> | |
37 | #include <linux/uaccess.h> | |
38 | #include <linux/cdev.h> | |
39 | #include <linux/io_uring.h> | |
40 | #include <linux/blk-mq.h> | |
41 | #include <linux/delay.h> | |
42 | #include <linux/mm.h> | |
43 | #include <asm/page.h> | |
0edb3696 | 44 | #include <linux/task_work.h> |
71f28f31 ML |
45 | #include <uapi/linux/ublk_cmd.h> |
46 | ||
47 | #define UBLK_MINORS (1U << MINORBITS) | |
48 | ||
0edb3696 ML |
49 | struct ublk_rq_data { |
50 | struct callback_head work; | |
51 | }; | |
52 | ||
71f28f31 ML |
53 | struct ublk_uring_cmd_pdu { |
54 | struct request *req; | |
55 | }; | |
56 | ||
57 | /* | |
58 | * io command is active: sqe cmd is received, and its cqe isn't done | |
59 | * | |
60 | * If the flag is set, the io command is owned by ublk driver, and waited | |
61 | * for incoming blk-mq request from the ublk block device. | |
62 | * | |
63 | * If the flag is cleared, the io command will be completed, and owned by | |
64 | * ublk server. | |
65 | */ | |
66 | #define UBLK_IO_FLAG_ACTIVE 0x01 | |
67 | ||
68 | /* | |
69 | * IO command is completed via cqe, and it is being handled by ublksrv, and | |
70 | * not committed yet | |
71 | * | |
72 | * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for | |
73 | * cross verification | |
74 | */ | |
75 | #define UBLK_IO_FLAG_OWNED_BY_SRV 0x02 | |
76 | ||
77 | /* | |
78 | * IO command is aborted, so this flag is set in case of | |
79 | * !UBLK_IO_FLAG_ACTIVE. | |
80 | * | |
81 | * After this flag is observed, any pending or new incoming request | |
82 | * associated with this io command will be failed immediately | |
83 | */ | |
84 | #define UBLK_IO_FLAG_ABORTED 0x04 | |
85 | ||
86 | struct ublk_io { | |
87 | /* userspace buffer address from io cmd */ | |
88 | __u64 addr; | |
89 | unsigned int flags; | |
90 | int res; | |
91 | ||
92 | struct io_uring_cmd *cmd; | |
93 | }; | |
94 | ||
95 | struct ublk_queue { | |
96 | int q_id; | |
97 | int q_depth; | |
98 | ||
0edb3696 | 99 | unsigned long flags; |
71f28f31 ML |
100 | struct task_struct *ubq_daemon; |
101 | char *io_cmd_buf; | |
102 | ||
103 | unsigned long io_addr; /* mapped vm address */ | |
104 | unsigned int max_io_sz; | |
105 | bool abort_work_pending; | |
106 | unsigned short nr_io_ready; /* how many ios setup */ | |
107 | struct ublk_device *dev; | |
108 | struct ublk_io ios[0]; | |
109 | }; | |
110 | ||
111 | #define UBLK_DAEMON_MONITOR_PERIOD (5 * HZ) | |
112 | ||
113 | struct ublk_device { | |
114 | struct gendisk *ub_disk; | |
71f28f31 ML |
115 | |
116 | char *__queues; | |
117 | ||
118 | unsigned short queue_size; | |
119 | unsigned short bs_shift; | |
120 | struct ublksrv_ctrl_dev_info dev_info; | |
121 | ||
122 | struct blk_mq_tag_set tag_set; | |
123 | ||
124 | struct cdev cdev; | |
125 | struct device cdev_dev; | |
126 | ||
fa362045 | 127 | #define UB_STATE_OPEN (1 << 0) |
6d9e6dfd | 128 | #define UB_STATE_USED (1 << 1) |
fa362045 | 129 | unsigned long state; |
71f28f31 ML |
130 | int ub_number; |
131 | ||
132 | struct mutex mutex; | |
133 | ||
e94eb459 | 134 | spinlock_t mm_lock; |
71f28f31 ML |
135 | struct mm_struct *mm; |
136 | ||
137 | struct completion completion; | |
138 | unsigned int nr_queues_ready; | |
139 | atomic_t nr_aborted_queues; | |
140 | ||
141 | /* | |
142 | * Our ubq->daemon may be killed without any notification, so | |
143 | * monitor each queue's daemon periodically | |
144 | */ | |
145 | struct delayed_work monitor_work; | |
146 | struct work_struct stop_work; | |
147 | }; | |
148 | ||
149 | static dev_t ublk_chr_devt; | |
150 | static struct class *ublk_chr_class; | |
151 | ||
152 | static DEFINE_IDR(ublk_index_idr); | |
153 | static DEFINE_SPINLOCK(ublk_idr_lock); | |
154 | static wait_queue_head_t ublk_idr_wq; /* wait until one idr is freed */ | |
155 | ||
156 | static DEFINE_MUTEX(ublk_ctl_mutex); | |
157 | ||
158 | static struct miscdevice ublk_misc; | |
159 | ||
0edb3696 ML |
160 | static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq) |
161 | { | |
162 | if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK) && | |
163 | !(ubq->flags & UBLK_F_URING_CMD_COMP_IN_TASK)) | |
164 | return true; | |
165 | return false; | |
166 | } | |
167 | ||
71f28f31 ML |
168 | static struct ublk_device *ublk_get_device(struct ublk_device *ub) |
169 | { | |
170 | if (kobject_get_unless_zero(&ub->cdev_dev.kobj)) | |
171 | return ub; | |
172 | return NULL; | |
173 | } | |
174 | ||
175 | static void ublk_put_device(struct ublk_device *ub) | |
176 | { | |
177 | put_device(&ub->cdev_dev); | |
178 | } | |
179 | ||
180 | static inline struct ublk_queue *ublk_get_queue(struct ublk_device *dev, | |
181 | int qid) | |
182 | { | |
183 | return (struct ublk_queue *)&(dev->__queues[qid * dev->queue_size]); | |
184 | } | |
185 | ||
186 | static inline bool ublk_rq_has_data(const struct request *rq) | |
187 | { | |
188 | return rq->bio && bio_has_data(rq->bio); | |
189 | } | |
190 | ||
191 | static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq, | |
192 | int tag) | |
193 | { | |
194 | return (struct ublksrv_io_desc *) | |
195 | &(ubq->io_cmd_buf[tag * sizeof(struct ublksrv_io_desc)]); | |
196 | } | |
197 | ||
198 | static inline char *ublk_queue_cmd_buf(struct ublk_device *ub, int q_id) | |
199 | { | |
200 | return ublk_get_queue(ub, q_id)->io_cmd_buf; | |
201 | } | |
202 | ||
203 | static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) | |
204 | { | |
205 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
206 | ||
207 | return round_up(ubq->q_depth * sizeof(struct ublksrv_io_desc), | |
208 | PAGE_SIZE); | |
209 | } | |
210 | ||
6d9e6dfd CH |
211 | static void ublk_free_disk(struct gendisk *disk) |
212 | { | |
213 | struct ublk_device *ub = disk->private_data; | |
214 | ||
215 | clear_bit(UB_STATE_USED, &ub->state); | |
216 | put_device(&ub->cdev_dev); | |
217 | } | |
218 | ||
71f28f31 ML |
219 | static const struct block_device_operations ub_fops = { |
220 | .owner = THIS_MODULE, | |
6d9e6dfd | 221 | .free_disk = ublk_free_disk, |
71f28f31 ML |
222 | }; |
223 | ||
224 | #define UBLK_MAX_PIN_PAGES 32 | |
225 | ||
226 | struct ublk_map_data { | |
227 | const struct ublk_queue *ubq; | |
228 | const struct request *rq; | |
229 | const struct ublk_io *io; | |
230 | unsigned max_bytes; | |
231 | }; | |
232 | ||
233 | struct ublk_io_iter { | |
234 | struct page *pages[UBLK_MAX_PIN_PAGES]; | |
235 | unsigned pg_off; /* offset in the 1st page in pages */ | |
236 | int nr_pages; /* how many page pointers in pages */ | |
237 | struct bio *bio; | |
238 | struct bvec_iter iter; | |
239 | }; | |
240 | ||
241 | static inline unsigned ublk_copy_io_pages(struct ublk_io_iter *data, | |
242 | unsigned max_bytes, bool to_vm) | |
243 | { | |
244 | const unsigned total = min_t(unsigned, max_bytes, | |
245 | PAGE_SIZE - data->pg_off + | |
246 | ((data->nr_pages - 1) << PAGE_SHIFT)); | |
247 | unsigned done = 0; | |
248 | unsigned pg_idx = 0; | |
249 | ||
250 | while (done < total) { | |
251 | struct bio_vec bv = bio_iter_iovec(data->bio, data->iter); | |
252 | const unsigned int bytes = min3(bv.bv_len, total - done, | |
253 | (unsigned)(PAGE_SIZE - data->pg_off)); | |
254 | void *bv_buf = bvec_kmap_local(&bv); | |
255 | void *pg_buf = kmap_local_page(data->pages[pg_idx]); | |
256 | ||
257 | if (to_vm) | |
258 | memcpy(pg_buf + data->pg_off, bv_buf, bytes); | |
259 | else | |
260 | memcpy(bv_buf, pg_buf + data->pg_off, bytes); | |
261 | ||
262 | kunmap_local(pg_buf); | |
263 | kunmap_local(bv_buf); | |
264 | ||
265 | /* advance page array */ | |
266 | data->pg_off += bytes; | |
267 | if (data->pg_off == PAGE_SIZE) { | |
268 | pg_idx += 1; | |
269 | data->pg_off = 0; | |
270 | } | |
271 | ||
272 | done += bytes; | |
273 | ||
274 | /* advance bio */ | |
275 | bio_advance_iter_single(data->bio, &data->iter, bytes); | |
276 | if (!data->iter.bi_size) { | |
277 | data->bio = data->bio->bi_next; | |
278 | if (data->bio == NULL) | |
279 | break; | |
280 | data->iter = data->bio->bi_iter; | |
281 | } | |
282 | } | |
283 | ||
284 | return done; | |
285 | } | |
286 | ||
287 | static inline int ublk_copy_user_pages(struct ublk_map_data *data, | |
288 | bool to_vm) | |
289 | { | |
290 | const unsigned int gup_flags = to_vm ? FOLL_WRITE : 0; | |
291 | const unsigned long start_vm = data->io->addr; | |
292 | unsigned int done = 0; | |
293 | struct ublk_io_iter iter = { | |
294 | .pg_off = start_vm & (PAGE_SIZE - 1), | |
295 | .bio = data->rq->bio, | |
296 | .iter = data->rq->bio->bi_iter, | |
297 | }; | |
298 | const unsigned int nr_pages = round_up(data->max_bytes + | |
299 | (start_vm & (PAGE_SIZE - 1)), PAGE_SIZE) >> PAGE_SHIFT; | |
300 | ||
301 | while (done < nr_pages) { | |
302 | const unsigned to_pin = min_t(unsigned, UBLK_MAX_PIN_PAGES, | |
303 | nr_pages - done); | |
304 | unsigned i, len; | |
305 | ||
306 | iter.nr_pages = get_user_pages_fast(start_vm + | |
307 | (done << PAGE_SHIFT), to_pin, gup_flags, | |
308 | iter.pages); | |
309 | if (iter.nr_pages <= 0) | |
310 | return done == 0 ? iter.nr_pages : done; | |
311 | len = ublk_copy_io_pages(&iter, data->max_bytes, to_vm); | |
312 | for (i = 0; i < iter.nr_pages; i++) { | |
313 | if (to_vm) | |
314 | set_page_dirty(iter.pages[i]); | |
315 | put_page(iter.pages[i]); | |
316 | } | |
317 | data->max_bytes -= len; | |
318 | done += iter.nr_pages; | |
319 | } | |
320 | ||
321 | return done; | |
322 | } | |
323 | ||
324 | static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req, | |
325 | struct ublk_io *io) | |
326 | { | |
327 | const unsigned int rq_bytes = blk_rq_bytes(req); | |
328 | /* | |
329 | * no zero copy, we delay copy WRITE request data into ublksrv | |
330 | * context and the big benefit is that pinning pages in current | |
331 | * context is pretty fast, see ublk_pin_user_pages | |
332 | */ | |
333 | if (req_op(req) != REQ_OP_WRITE && req_op(req) != REQ_OP_FLUSH) | |
334 | return rq_bytes; | |
335 | ||
336 | if (ublk_rq_has_data(req)) { | |
337 | struct ublk_map_data data = { | |
338 | .ubq = ubq, | |
339 | .rq = req, | |
340 | .io = io, | |
341 | .max_bytes = rq_bytes, | |
342 | }; | |
343 | ||
344 | ublk_copy_user_pages(&data, true); | |
345 | ||
346 | return rq_bytes - data.max_bytes; | |
347 | } | |
348 | return rq_bytes; | |
349 | } | |
350 | ||
351 | static int ublk_unmap_io(const struct ublk_queue *ubq, | |
352 | const struct request *req, | |
353 | struct ublk_io *io) | |
354 | { | |
355 | const unsigned int rq_bytes = blk_rq_bytes(req); | |
356 | ||
357 | if (req_op(req) == REQ_OP_READ && ublk_rq_has_data(req)) { | |
358 | struct ublk_map_data data = { | |
359 | .ubq = ubq, | |
360 | .rq = req, | |
361 | .io = io, | |
362 | .max_bytes = io->res, | |
363 | }; | |
364 | ||
365 | WARN_ON_ONCE(io->res > rq_bytes); | |
366 | ||
367 | ublk_copy_user_pages(&data, false); | |
368 | ||
369 | return io->res - data.max_bytes; | |
370 | } | |
371 | return rq_bytes; | |
372 | } | |
373 | ||
374 | static inline unsigned int ublk_req_build_flags(struct request *req) | |
375 | { | |
376 | unsigned flags = 0; | |
377 | ||
378 | if (req->cmd_flags & REQ_FAILFAST_DEV) | |
379 | flags |= UBLK_IO_F_FAILFAST_DEV; | |
380 | ||
381 | if (req->cmd_flags & REQ_FAILFAST_TRANSPORT) | |
382 | flags |= UBLK_IO_F_FAILFAST_TRANSPORT; | |
383 | ||
384 | if (req->cmd_flags & REQ_FAILFAST_DRIVER) | |
385 | flags |= UBLK_IO_F_FAILFAST_DRIVER; | |
386 | ||
387 | if (req->cmd_flags & REQ_META) | |
388 | flags |= UBLK_IO_F_META; | |
389 | ||
71f28f31 ML |
390 | if (req->cmd_flags & REQ_FUA) |
391 | flags |= UBLK_IO_F_FUA; | |
392 | ||
71f28f31 ML |
393 | if (req->cmd_flags & REQ_NOUNMAP) |
394 | flags |= UBLK_IO_F_NOUNMAP; | |
395 | ||
396 | if (req->cmd_flags & REQ_SWAP) | |
397 | flags |= UBLK_IO_F_SWAP; | |
398 | ||
399 | return flags; | |
400 | } | |
401 | ||
f2450f8a | 402 | static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req) |
71f28f31 ML |
403 | { |
404 | struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag); | |
405 | struct ublk_io *io = &ubq->ios[req->tag]; | |
406 | u32 ublk_op; | |
407 | ||
408 | switch (req_op(req)) { | |
409 | case REQ_OP_READ: | |
410 | ublk_op = UBLK_IO_OP_READ; | |
411 | break; | |
412 | case REQ_OP_WRITE: | |
413 | ublk_op = UBLK_IO_OP_WRITE; | |
414 | break; | |
415 | case REQ_OP_FLUSH: | |
416 | ublk_op = UBLK_IO_OP_FLUSH; | |
417 | break; | |
418 | case REQ_OP_DISCARD: | |
419 | ublk_op = UBLK_IO_OP_DISCARD; | |
420 | break; | |
421 | case REQ_OP_WRITE_ZEROES: | |
422 | ublk_op = UBLK_IO_OP_WRITE_ZEROES; | |
423 | break; | |
424 | default: | |
425 | return BLK_STS_IOERR; | |
426 | } | |
427 | ||
428 | /* need to translate since kernel may change */ | |
429 | iod->op_flags = ublk_op | ublk_req_build_flags(req); | |
430 | iod->nr_sectors = blk_rq_sectors(req); | |
431 | iod->start_sector = blk_rq_pos(req); | |
432 | iod->addr = io->addr; | |
433 | ||
434 | return BLK_STS_OK; | |
435 | } | |
436 | ||
437 | static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu( | |
438 | struct io_uring_cmd *ioucmd) | |
439 | { | |
440 | return (struct ublk_uring_cmd_pdu *)&ioucmd->pdu; | |
441 | } | |
442 | ||
443 | static bool ubq_daemon_is_dying(struct ublk_queue *ubq) | |
444 | { | |
445 | return ubq->ubq_daemon->flags & PF_EXITING; | |
446 | } | |
447 | ||
448 | /* todo: handle partial completion */ | |
449 | static void ublk_complete_rq(struct request *req) | |
450 | { | |
451 | struct ublk_queue *ubq = req->mq_hctx->driver_data; | |
452 | struct ublk_io *io = &ubq->ios[req->tag]; | |
453 | unsigned int unmapped_bytes; | |
454 | ||
455 | /* failed read IO if nothing is read */ | |
456 | if (!io->res && req_op(req) == REQ_OP_READ) | |
457 | io->res = -EIO; | |
458 | ||
459 | if (io->res < 0) { | |
460 | blk_mq_end_request(req, errno_to_blk_status(io->res)); | |
461 | return; | |
462 | } | |
463 | ||
464 | /* | |
465 | * FLUSH or DISCARD usually won't return bytes returned, so end them | |
466 | * directly. | |
467 | * | |
468 | * Both the two needn't unmap. | |
469 | */ | |
470 | if (req_op(req) != REQ_OP_READ && req_op(req) != REQ_OP_WRITE) { | |
471 | blk_mq_end_request(req, BLK_STS_OK); | |
472 | return; | |
473 | } | |
474 | ||
475 | /* for READ request, writing data in iod->addr to rq buffers */ | |
476 | unmapped_bytes = ublk_unmap_io(ubq, req, io); | |
477 | ||
478 | /* | |
479 | * Extremely impossible since we got data filled in just before | |
480 | * | |
481 | * Re-read simply for this unlikely case. | |
482 | */ | |
483 | if (unlikely(unmapped_bytes < io->res)) | |
484 | io->res = unmapped_bytes; | |
485 | ||
486 | if (blk_update_request(req, BLK_STS_OK, io->res)) | |
487 | blk_mq_requeue_request(req, true); | |
488 | else | |
489 | __blk_mq_end_request(req, BLK_STS_OK); | |
490 | } | |
491 | ||
492 | /* | |
493 | * __ublk_fail_req() may be called from abort context or ->ubq_daemon | |
494 | * context during exiting, so lock is required. | |
495 | * | |
496 | * Also aborting may not be started yet, keep in mind that one failed | |
497 | * request may be issued by block layer again. | |
498 | */ | |
499 | static void __ublk_fail_req(struct ublk_io *io, struct request *req) | |
500 | { | |
501 | WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); | |
502 | ||
503 | if (!(io->flags & UBLK_IO_FLAG_ABORTED)) { | |
504 | io->flags |= UBLK_IO_FLAG_ABORTED; | |
505 | blk_mq_end_request(req, BLK_STS_IOERR); | |
506 | } | |
507 | } | |
508 | ||
509 | #define UBLK_REQUEUE_DELAY_MS 3 | |
510 | ||
0edb3696 | 511 | static inline void __ublk_rq_task_work(struct request *req) |
71f28f31 | 512 | { |
71f28f31 | 513 | struct ublk_queue *ubq = req->mq_hctx->driver_data; |
0edb3696 | 514 | struct ublk_device *ub = ubq->dev; |
71f28f31 ML |
515 | int tag = req->tag; |
516 | struct ublk_io *io = &ubq->ios[tag]; | |
517 | bool task_exiting = current != ubq->ubq_daemon || | |
518 | (current->flags & PF_EXITING); | |
519 | unsigned int mapped_bytes; | |
520 | ||
521 | pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n", | |
522 | __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, | |
523 | ublk_get_iod(ubq, req->tag)->addr); | |
524 | ||
525 | if (unlikely(task_exiting)) { | |
526 | blk_mq_end_request(req, BLK_STS_IOERR); | |
527 | mod_delayed_work(system_wq, &ub->monitor_work, 0); | |
528 | return; | |
529 | } | |
530 | ||
531 | mapped_bytes = ublk_map_io(ubq, req, io); | |
532 | ||
533 | /* partially mapped, update io descriptor */ | |
534 | if (unlikely(mapped_bytes != blk_rq_bytes(req))) { | |
535 | /* | |
536 | * Nothing mapped, retry until we succeed. | |
537 | * | |
538 | * We may never succeed in mapping any bytes here because | |
539 | * of OOM. TODO: reserve one buffer with single page pinned | |
540 | * for providing forward progress guarantee. | |
541 | */ | |
542 | if (unlikely(!mapped_bytes)) { | |
543 | blk_mq_requeue_request(req, false); | |
544 | blk_mq_delay_kick_requeue_list(req->q, | |
545 | UBLK_REQUEUE_DELAY_MS); | |
546 | return; | |
547 | } | |
548 | ||
549 | ublk_get_iod(ubq, req->tag)->nr_sectors = | |
550 | mapped_bytes >> 9; | |
551 | } | |
552 | ||
553 | /* mark this cmd owned by ublksrv */ | |
554 | io->flags |= UBLK_IO_FLAG_OWNED_BY_SRV; | |
555 | ||
556 | /* | |
557 | * clear ACTIVE since we are done with this sqe/cmd slot | |
558 | * We can only accept io cmd in case of being not active. | |
559 | */ | |
560 | io->flags &= ~UBLK_IO_FLAG_ACTIVE; | |
561 | ||
562 | /* tell ublksrv one io request is coming */ | |
563 | io_uring_cmd_done(io->cmd, UBLK_IO_RES_OK, 0); | |
564 | } | |
565 | ||
0edb3696 ML |
566 | static void ublk_rq_task_work_cb(struct io_uring_cmd *cmd) |
567 | { | |
568 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); | |
569 | ||
570 | __ublk_rq_task_work(pdu->req); | |
571 | } | |
572 | ||
573 | static void ublk_rq_task_work_fn(struct callback_head *work) | |
574 | { | |
575 | struct ublk_rq_data *data = container_of(work, | |
576 | struct ublk_rq_data, work); | |
577 | struct request *req = blk_mq_rq_from_pdu(data); | |
578 | ||
579 | __ublk_rq_task_work(req); | |
580 | } | |
581 | ||
71f28f31 ML |
582 | static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, |
583 | const struct blk_mq_queue_data *bd) | |
584 | { | |
585 | struct ublk_queue *ubq = hctx->driver_data; | |
586 | struct request *rq = bd->rq; | |
71f28f31 ML |
587 | blk_status_t res; |
588 | ||
589 | /* fill iod to slot in io cmd buffer */ | |
590 | res = ublk_setup_iod(ubq, rq); | |
591 | if (unlikely(res != BLK_STS_OK)) | |
592 | return BLK_STS_IOERR; | |
593 | ||
594 | blk_mq_start_request(bd->rq); | |
595 | ||
596 | if (unlikely(ubq_daemon_is_dying(ubq))) { | |
0edb3696 | 597 | fail: |
71f28f31 ML |
598 | mod_delayed_work(system_wq, &ubq->dev->monitor_work, 0); |
599 | return BLK_STS_IOERR; | |
600 | } | |
601 | ||
0edb3696 ML |
602 | if (ublk_can_use_task_work(ubq)) { |
603 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq); | |
604 | enum task_work_notify_mode notify_mode = bd->last ? | |
605 | TWA_SIGNAL_NO_IPI : TWA_NONE; | |
606 | ||
607 | if (task_work_add(ubq->ubq_daemon, &data->work, notify_mode)) | |
608 | goto fail; | |
609 | } else { | |
610 | struct io_uring_cmd *cmd = ubq->ios[rq->tag].cmd; | |
611 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); | |
612 | ||
613 | pdu->req = rq; | |
614 | io_uring_cmd_complete_in_task(cmd, ublk_rq_task_work_cb); | |
615 | } | |
71f28f31 ML |
616 | |
617 | return BLK_STS_OK; | |
618 | } | |
619 | ||
0edb3696 ML |
620 | static void ublk_commit_rqs(struct blk_mq_hw_ctx *hctx) |
621 | { | |
622 | struct ublk_queue *ubq = hctx->driver_data; | |
623 | ||
624 | if (ublk_can_use_task_work(ubq)) | |
625 | __set_notify_signal(ubq->ubq_daemon); | |
626 | } | |
71f28f31 ML |
627 | |
628 | static int ublk_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data, | |
629 | unsigned int hctx_idx) | |
630 | { | |
cebbe577 | 631 | struct ublk_device *ub = driver_data; |
71f28f31 ML |
632 | struct ublk_queue *ubq = ublk_get_queue(ub, hctx->queue_num); |
633 | ||
634 | hctx->driver_data = ubq; | |
635 | return 0; | |
636 | } | |
637 | ||
0edb3696 ML |
638 | static int ublk_init_rq(struct blk_mq_tag_set *set, struct request *req, |
639 | unsigned int hctx_idx, unsigned int numa_node) | |
640 | { | |
641 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); | |
642 | ||
643 | init_task_work(&data->work, ublk_rq_task_work_fn); | |
644 | return 0; | |
645 | } | |
646 | ||
71f28f31 ML |
647 | static const struct blk_mq_ops ublk_mq_ops = { |
648 | .queue_rq = ublk_queue_rq, | |
0edb3696 | 649 | .commit_rqs = ublk_commit_rqs, |
71f28f31 | 650 | .init_hctx = ublk_init_hctx, |
0edb3696 | 651 | .init_request = ublk_init_rq, |
71f28f31 ML |
652 | }; |
653 | ||
654 | static int ublk_ch_open(struct inode *inode, struct file *filp) | |
655 | { | |
656 | struct ublk_device *ub = container_of(inode->i_cdev, | |
657 | struct ublk_device, cdev); | |
658 | ||
fa362045 CH |
659 | if (test_and_set_bit(UB_STATE_OPEN, &ub->state)) |
660 | return -EBUSY; | |
661 | filp->private_data = ub; | |
662 | return 0; | |
71f28f31 ML |
663 | } |
664 | ||
665 | static int ublk_ch_release(struct inode *inode, struct file *filp) | |
666 | { | |
667 | struct ublk_device *ub = filp->private_data; | |
668 | ||
fa362045 | 669 | clear_bit(UB_STATE_OPEN, &ub->state); |
71f28f31 ML |
670 | return 0; |
671 | } | |
672 | ||
673 | /* map pre-allocated per-queue cmd buffer to ublksrv daemon */ | |
674 | static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma) | |
675 | { | |
676 | struct ublk_device *ub = filp->private_data; | |
677 | size_t sz = vma->vm_end - vma->vm_start; | |
678 | unsigned max_sz = UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc); | |
679 | unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT; | |
680 | int q_id, ret = 0; | |
681 | ||
e94eb459 | 682 | spin_lock(&ub->mm_lock); |
71f28f31 ML |
683 | if (!ub->mm) |
684 | ub->mm = current->mm; | |
685 | if (current->mm != ub->mm) | |
686 | ret = -EINVAL; | |
e94eb459 | 687 | spin_unlock(&ub->mm_lock); |
71f28f31 ML |
688 | |
689 | if (ret) | |
690 | return ret; | |
691 | ||
692 | if (vma->vm_flags & VM_WRITE) | |
693 | return -EPERM; | |
694 | ||
695 | end = UBLKSRV_CMD_BUF_OFFSET + ub->dev_info.nr_hw_queues * max_sz; | |
696 | if (phys_off < UBLKSRV_CMD_BUF_OFFSET || phys_off >= end) | |
697 | return -EINVAL; | |
698 | ||
699 | q_id = (phys_off - UBLKSRV_CMD_BUF_OFFSET) / max_sz; | |
700 | pr_devel("%s: qid %d, pid %d, addr %lx pg_off %lx sz %lu\n", | |
701 | __func__, q_id, current->pid, vma->vm_start, | |
702 | phys_off, (unsigned long)sz); | |
703 | ||
704 | if (sz != ublk_queue_cmd_buf_size(ub, q_id)) | |
705 | return -EINVAL; | |
706 | ||
707 | pfn = virt_to_phys(ublk_queue_cmd_buf(ub, q_id)) >> PAGE_SHIFT; | |
708 | return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); | |
709 | } | |
710 | ||
711 | static void ublk_commit_completion(struct ublk_device *ub, | |
712 | struct ublksrv_io_cmd *ub_cmd) | |
713 | { | |
714 | u32 qid = ub_cmd->q_id, tag = ub_cmd->tag; | |
715 | struct ublk_queue *ubq = ublk_get_queue(ub, qid); | |
716 | struct ublk_io *io = &ubq->ios[tag]; | |
717 | struct request *req; | |
718 | ||
719 | /* now this cmd slot is owned by nbd driver */ | |
720 | io->flags &= ~UBLK_IO_FLAG_OWNED_BY_SRV; | |
721 | io->res = ub_cmd->result; | |
722 | ||
723 | /* find the io request and complete */ | |
724 | req = blk_mq_tag_to_rq(ub->tag_set.tags[qid], tag); | |
725 | ||
726 | if (req && likely(!blk_should_fake_timeout(req->q))) | |
727 | ublk_complete_rq(req); | |
728 | } | |
729 | ||
730 | /* | |
731 | * When ->ubq_daemon is exiting, either new request is ended immediately, | |
732 | * or any queued io command is drained, so it is safe to abort queue | |
733 | * lockless | |
734 | */ | |
735 | static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) | |
736 | { | |
737 | int i; | |
738 | ||
739 | if (!ublk_get_device(ub)) | |
740 | return; | |
741 | ||
742 | for (i = 0; i < ubq->q_depth; i++) { | |
743 | struct ublk_io *io = &ubq->ios[i]; | |
744 | ||
745 | if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) { | |
746 | struct request *rq; | |
747 | ||
748 | /* | |
749 | * Either we fail the request or ublk_rq_task_work_fn | |
750 | * will do it | |
751 | */ | |
752 | rq = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], i); | |
753 | if (rq) | |
754 | __ublk_fail_req(io, rq); | |
755 | } | |
756 | } | |
757 | ublk_put_device(ub); | |
758 | } | |
759 | ||
760 | static void ublk_daemon_monitor_work(struct work_struct *work) | |
761 | { | |
762 | struct ublk_device *ub = | |
763 | container_of(work, struct ublk_device, monitor_work.work); | |
764 | int i; | |
765 | ||
766 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) { | |
767 | struct ublk_queue *ubq = ublk_get_queue(ub, i); | |
768 | ||
769 | if (ubq_daemon_is_dying(ubq)) { | |
770 | schedule_work(&ub->stop_work); | |
771 | ||
772 | /* abort queue is for making forward progress */ | |
773 | ublk_abort_queue(ub, ubq); | |
774 | } | |
775 | } | |
776 | ||
777 | /* | |
778 | * We can't schedule monitor work after ublk_remove() is started. | |
779 | * | |
780 | * No need ub->mutex, monitor work are canceled after state is marked | |
781 | * as DEAD, so DEAD state is observed reliably. | |
782 | */ | |
783 | if (ub->dev_info.state != UBLK_S_DEV_DEAD) | |
784 | schedule_delayed_work(&ub->monitor_work, | |
785 | UBLK_DAEMON_MONITOR_PERIOD); | |
786 | } | |
787 | ||
788 | static void ublk_cancel_queue(struct ublk_queue *ubq) | |
789 | { | |
790 | int i; | |
791 | ||
792 | for (i = 0; i < ubq->q_depth; i++) { | |
793 | struct ublk_io *io = &ubq->ios[i]; | |
794 | ||
795 | if (io->flags & UBLK_IO_FLAG_ACTIVE) | |
796 | io_uring_cmd_done(io->cmd, UBLK_IO_RES_ABORT, 0); | |
797 | } | |
798 | } | |
799 | ||
800 | /* Cancel all pending commands, must be called after del_gendisk() returns */ | |
801 | static void ublk_cancel_dev(struct ublk_device *ub) | |
802 | { | |
803 | int i; | |
804 | ||
805 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) | |
806 | ublk_cancel_queue(ublk_get_queue(ub, i)); | |
807 | } | |
808 | ||
809 | static void ublk_stop_dev(struct ublk_device *ub) | |
810 | { | |
811 | mutex_lock(&ub->mutex); | |
6d9e6dfd | 812 | if (ub->dev_info.state != UBLK_S_DEV_LIVE) |
71f28f31 ML |
813 | goto unlock; |
814 | ||
815 | del_gendisk(ub->ub_disk); | |
816 | ub->dev_info.state = UBLK_S_DEV_DEAD; | |
817 | ub->dev_info.ublksrv_pid = -1; | |
818 | ublk_cancel_dev(ub); | |
6d9e6dfd CH |
819 | put_disk(ub->ub_disk); |
820 | ub->ub_disk = NULL; | |
71f28f31 ML |
821 | unlock: |
822 | mutex_unlock(&ub->mutex); | |
823 | cancel_delayed_work_sync(&ub->monitor_work); | |
824 | } | |
825 | ||
71f28f31 ML |
826 | static inline bool ublk_queue_ready(struct ublk_queue *ubq) |
827 | { | |
828 | return ubq->nr_io_ready == ubq->q_depth; | |
829 | } | |
830 | ||
831 | /* device can only be started after all IOs are ready */ | |
832 | static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq) | |
833 | { | |
834 | mutex_lock(&ub->mutex); | |
835 | ubq->nr_io_ready++; | |
836 | if (ublk_queue_ready(ubq)) { | |
837 | ubq->ubq_daemon = current; | |
838 | get_task_struct(ubq->ubq_daemon); | |
839 | ub->nr_queues_ready++; | |
840 | } | |
841 | if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues) | |
842 | complete_all(&ub->completion); | |
843 | mutex_unlock(&ub->mutex); | |
844 | } | |
845 | ||
846 | static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) | |
847 | { | |
848 | struct ublksrv_io_cmd *ub_cmd = (struct ublksrv_io_cmd *)cmd->cmd; | |
849 | struct ublk_device *ub = cmd->file->private_data; | |
850 | struct ublk_queue *ubq; | |
851 | struct ublk_io *io; | |
852 | u32 cmd_op = cmd->cmd_op; | |
853 | unsigned tag = ub_cmd->tag; | |
854 | int ret = -EINVAL; | |
855 | ||
856 | pr_devel("%s: received: cmd op %d queue %d tag %d result %d\n", | |
857 | __func__, cmd->cmd_op, ub_cmd->q_id, tag, | |
858 | ub_cmd->result); | |
859 | ||
860 | if (!(issue_flags & IO_URING_F_SQE128)) | |
861 | goto out; | |
862 | ||
863 | if (ub_cmd->q_id >= ub->dev_info.nr_hw_queues) | |
864 | goto out; | |
865 | ||
866 | ubq = ublk_get_queue(ub, ub_cmd->q_id); | |
867 | if (!ubq || ub_cmd->q_id != ubq->q_id) | |
868 | goto out; | |
869 | ||
870 | if (ubq->ubq_daemon && ubq->ubq_daemon != current) | |
871 | goto out; | |
872 | ||
873 | if (tag >= ubq->q_depth) | |
874 | goto out; | |
875 | ||
876 | io = &ubq->ios[tag]; | |
877 | ||
878 | /* there is pending io cmd, something must be wrong */ | |
879 | if (io->flags & UBLK_IO_FLAG_ACTIVE) { | |
880 | ret = -EBUSY; | |
881 | goto out; | |
882 | } | |
883 | ||
884 | switch (cmd_op) { | |
885 | case UBLK_IO_FETCH_REQ: | |
886 | /* UBLK_IO_FETCH_REQ is only allowed before queue is setup */ | |
887 | if (ublk_queue_ready(ubq)) { | |
888 | ret = -EBUSY; | |
889 | goto out; | |
890 | } | |
891 | /* | |
892 | * The io is being handled by server, so COMMIT_RQ is expected | |
893 | * instead of FETCH_REQ | |
894 | */ | |
895 | if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV) | |
896 | goto out; | |
897 | /* FETCH_RQ has to provide IO buffer */ | |
898 | if (!ub_cmd->addr) | |
899 | goto out; | |
900 | io->cmd = cmd; | |
901 | io->flags |= UBLK_IO_FLAG_ACTIVE; | |
902 | io->addr = ub_cmd->addr; | |
903 | ||
904 | ublk_mark_io_ready(ub, ubq); | |
905 | break; | |
906 | case UBLK_IO_COMMIT_AND_FETCH_REQ: | |
907 | /* FETCH_RQ has to provide IO buffer */ | |
908 | if (!ub_cmd->addr) | |
909 | goto out; | |
910 | if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) | |
911 | goto out; | |
912 | io->addr = ub_cmd->addr; | |
913 | io->flags |= UBLK_IO_FLAG_ACTIVE; | |
914 | io->cmd = cmd; | |
915 | ublk_commit_completion(ub, ub_cmd); | |
916 | break; | |
917 | default: | |
918 | goto out; | |
919 | } | |
920 | return -EIOCBQUEUED; | |
921 | ||
922 | out: | |
71f28f31 ML |
923 | io_uring_cmd_done(cmd, ret, 0); |
924 | pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n", | |
925 | __func__, cmd_op, tag, ret, io->flags); | |
926 | return -EIOCBQUEUED; | |
927 | } | |
928 | ||
929 | static const struct file_operations ublk_ch_fops = { | |
930 | .owner = THIS_MODULE, | |
931 | .open = ublk_ch_open, | |
932 | .release = ublk_ch_release, | |
933 | .llseek = no_llseek, | |
934 | .uring_cmd = ublk_ch_uring_cmd, | |
935 | .mmap = ublk_ch_mmap, | |
936 | }; | |
937 | ||
938 | static void ublk_deinit_queue(struct ublk_device *ub, int q_id) | |
939 | { | |
940 | int size = ublk_queue_cmd_buf_size(ub, q_id); | |
941 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
942 | ||
943 | if (ubq->ubq_daemon) | |
944 | put_task_struct(ubq->ubq_daemon); | |
945 | if (ubq->io_cmd_buf) | |
946 | free_pages((unsigned long)ubq->io_cmd_buf, get_order(size)); | |
947 | } | |
948 | ||
949 | static int ublk_init_queue(struct ublk_device *ub, int q_id) | |
950 | { | |
951 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
952 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO; | |
953 | void *ptr; | |
954 | int size; | |
955 | ||
0edb3696 | 956 | ubq->flags = ub->dev_info.flags[0]; |
71f28f31 ML |
957 | ubq->q_id = q_id; |
958 | ubq->q_depth = ub->dev_info.queue_depth; | |
959 | size = ublk_queue_cmd_buf_size(ub, q_id); | |
960 | ||
961 | ptr = (void *) __get_free_pages(gfp_flags, get_order(size)); | |
962 | if (!ptr) | |
963 | return -ENOMEM; | |
964 | ||
965 | ubq->io_cmd_buf = ptr; | |
966 | ubq->dev = ub; | |
967 | return 0; | |
968 | } | |
969 | ||
970 | static void ublk_deinit_queues(struct ublk_device *ub) | |
971 | { | |
972 | int nr_queues = ub->dev_info.nr_hw_queues; | |
973 | int i; | |
974 | ||
975 | if (!ub->__queues) | |
976 | return; | |
977 | ||
978 | for (i = 0; i < nr_queues; i++) | |
979 | ublk_deinit_queue(ub, i); | |
980 | kfree(ub->__queues); | |
981 | } | |
982 | ||
983 | static int ublk_init_queues(struct ublk_device *ub) | |
984 | { | |
985 | int nr_queues = ub->dev_info.nr_hw_queues; | |
986 | int depth = ub->dev_info.queue_depth; | |
987 | int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io); | |
988 | int i, ret = -ENOMEM; | |
989 | ||
990 | ub->queue_size = ubq_size; | |
991 | ub->__queues = kcalloc(nr_queues, ubq_size, GFP_KERNEL); | |
992 | if (!ub->__queues) | |
993 | return ret; | |
994 | ||
995 | for (i = 0; i < nr_queues; i++) { | |
996 | if (ublk_init_queue(ub, i)) | |
997 | goto fail; | |
998 | } | |
999 | ||
1000 | init_completion(&ub->completion); | |
1001 | return 0; | |
1002 | ||
1003 | fail: | |
1004 | ublk_deinit_queues(ub); | |
1005 | return ret; | |
1006 | } | |
1007 | ||
fa9482e0 | 1008 | static int ublk_alloc_dev_number(struct ublk_device *ub, int idx) |
71f28f31 ML |
1009 | { |
1010 | int i = idx; | |
1011 | int err; | |
1012 | ||
1013 | spin_lock(&ublk_idr_lock); | |
1014 | /* allocate id, if @id >= 0, we're requesting that specific id */ | |
1015 | if (i >= 0) { | |
1016 | err = idr_alloc(&ublk_index_idr, ub, i, i + 1, GFP_NOWAIT); | |
1017 | if (err == -ENOSPC) | |
1018 | err = -EEXIST; | |
1019 | } else { | |
1020 | err = idr_alloc(&ublk_index_idr, ub, 0, 0, GFP_NOWAIT); | |
1021 | } | |
1022 | spin_unlock(&ublk_idr_lock); | |
1023 | ||
1024 | if (err >= 0) | |
1025 | ub->ub_number = err; | |
1026 | ||
1027 | return err; | |
1028 | } | |
1029 | ||
fa9482e0 | 1030 | static void ublk_free_dev_number(struct ublk_device *ub) |
71f28f31 ML |
1031 | { |
1032 | spin_lock(&ublk_idr_lock); | |
1033 | idr_remove(&ublk_index_idr, ub->ub_number); | |
1034 | wake_up_all(&ublk_idr_wq); | |
1035 | spin_unlock(&ublk_idr_lock); | |
71f28f31 ML |
1036 | } |
1037 | ||
1038 | static void ublk_cdev_rel(struct device *dev) | |
1039 | { | |
1040 | struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev); | |
1041 | ||
71f28f31 | 1042 | blk_mq_free_tag_set(&ub->tag_set); |
71f28f31 | 1043 | ublk_deinit_queues(ub); |
fa9482e0 CH |
1044 | ublk_free_dev_number(ub); |
1045 | mutex_destroy(&ub->mutex); | |
1046 | kfree(ub); | |
71f28f31 ML |
1047 | } |
1048 | ||
1049 | static int ublk_add_chdev(struct ublk_device *ub) | |
1050 | { | |
1051 | struct device *dev = &ub->cdev_dev; | |
1052 | int minor = ub->ub_number; | |
1053 | int ret; | |
1054 | ||
1055 | dev->parent = ublk_misc.this_device; | |
1056 | dev->devt = MKDEV(MAJOR(ublk_chr_devt), minor); | |
1057 | dev->class = ublk_chr_class; | |
1058 | dev->release = ublk_cdev_rel; | |
1059 | device_initialize(dev); | |
1060 | ||
1061 | ret = dev_set_name(dev, "ublkc%d", minor); | |
1062 | if (ret) | |
1063 | goto fail; | |
1064 | ||
1065 | cdev_init(&ub->cdev, &ublk_ch_fops); | |
1066 | ret = cdev_device_add(&ub->cdev, dev); | |
1067 | if (ret) | |
1068 | goto fail; | |
1069 | return 0; | |
1070 | fail: | |
1071 | put_device(dev); | |
1072 | return ret; | |
1073 | } | |
1074 | ||
1075 | static void ublk_stop_work_fn(struct work_struct *work) | |
1076 | { | |
1077 | struct ublk_device *ub = | |
1078 | container_of(work, struct ublk_device, stop_work); | |
1079 | ||
1080 | ublk_stop_dev(ub); | |
1081 | } | |
1082 | ||
6d9e6dfd CH |
1083 | /* align maximum I/O size to PAGE_SIZE */ |
1084 | static void ublk_align_max_io_size(struct ublk_device *ub) | |
71f28f31 | 1085 | { |
6d9e6dfd | 1086 | unsigned int max_rq_bytes = ub->dev_info.rq_max_blocks << ub->bs_shift; |
71f28f31 | 1087 | |
6d9e6dfd CH |
1088 | ub->dev_info.rq_max_blocks = |
1089 | round_down(max_rq_bytes, PAGE_SIZE) >> ub->bs_shift; | |
71f28f31 ML |
1090 | } |
1091 | ||
fa9482e0 | 1092 | static int ublk_add_tag_set(struct ublk_device *ub) |
71f28f31 | 1093 | { |
71f28f31 ML |
1094 | ub->tag_set.ops = &ublk_mq_ops; |
1095 | ub->tag_set.nr_hw_queues = ub->dev_info.nr_hw_queues; | |
1096 | ub->tag_set.queue_depth = ub->dev_info.queue_depth; | |
1097 | ub->tag_set.numa_node = NUMA_NO_NODE; | |
0edb3696 | 1098 | ub->tag_set.cmd_size = sizeof(struct ublk_rq_data); |
71f28f31 ML |
1099 | ub->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; |
1100 | ub->tag_set.driver_data = ub; | |
fa9482e0 | 1101 | return blk_mq_alloc_tag_set(&ub->tag_set); |
71f28f31 ML |
1102 | } |
1103 | ||
1104 | static void ublk_remove(struct ublk_device *ub) | |
1105 | { | |
34d8f2be CH |
1106 | ublk_stop_dev(ub); |
1107 | cancel_work_sync(&ub->stop_work); | |
71f28f31 ML |
1108 | cdev_device_del(&ub->cdev, &ub->cdev_dev); |
1109 | put_device(&ub->cdev_dev); | |
1110 | } | |
1111 | ||
1112 | static struct ublk_device *ublk_get_device_from_id(int idx) | |
1113 | { | |
1114 | struct ublk_device *ub = NULL; | |
1115 | ||
1116 | if (idx < 0) | |
1117 | return NULL; | |
1118 | ||
1119 | spin_lock(&ublk_idr_lock); | |
1120 | ub = idr_find(&ublk_index_idr, idx); | |
1121 | if (ub) | |
1122 | ub = ublk_get_device(ub); | |
1123 | spin_unlock(&ublk_idr_lock); | |
1124 | ||
1125 | return ub; | |
1126 | } | |
1127 | ||
34d8f2be | 1128 | static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd) |
71f28f31 ML |
1129 | { |
1130 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
71f28f31 ML |
1131 | int ublksrv_pid = (int)header->data[0]; |
1132 | unsigned long dev_blocks = header->data[1]; | |
34d8f2be | 1133 | struct ublk_device *ub; |
6d9e6dfd | 1134 | struct gendisk *disk; |
34d8f2be | 1135 | int ret = -EINVAL; |
71f28f31 ML |
1136 | |
1137 | if (ublksrv_pid <= 0) | |
34d8f2be CH |
1138 | return -EINVAL; |
1139 | ||
1140 | ub = ublk_get_device_from_id(header->dev_id); | |
1141 | if (!ub) | |
1142 | return -EINVAL; | |
71f28f31 ML |
1143 | |
1144 | wait_for_completion_interruptible(&ub->completion); | |
1145 | ||
1146 | schedule_delayed_work(&ub->monitor_work, UBLK_DAEMON_MONITOR_PERIOD); | |
1147 | ||
1148 | mutex_lock(&ub->mutex); | |
6d9e6dfd CH |
1149 | if (ub->dev_info.state == UBLK_S_DEV_LIVE || |
1150 | test_bit(UB_STATE_USED, &ub->state)) { | |
71f28f31 | 1151 | ret = -EEXIST; |
34d8f2be | 1152 | goto out_unlock; |
71f28f31 | 1153 | } |
71f28f31 | 1154 | |
34d8f2be | 1155 | /* We may get disk size updated */ |
6d9e6dfd | 1156 | if (dev_blocks) |
34d8f2be | 1157 | ub->dev_info.dev_blocks = dev_blocks; |
6d9e6dfd CH |
1158 | |
1159 | disk = blk_mq_alloc_disk(&ub->tag_set, ub); | |
1160 | if (IS_ERR(disk)) { | |
1161 | ret = PTR_ERR(disk); | |
1162 | goto out_unlock; | |
34d8f2be | 1163 | } |
6d9e6dfd CH |
1164 | sprintf(disk->disk_name, "ublkb%d", ub->ub_number); |
1165 | disk->fops = &ub_fops; | |
1166 | disk->private_data = ub; | |
1167 | ||
1168 | blk_queue_logical_block_size(disk->queue, ub->dev_info.block_size); | |
1169 | blk_queue_physical_block_size(disk->queue, ub->dev_info.block_size); | |
1170 | blk_queue_io_min(disk->queue, ub->dev_info.block_size); | |
1171 | blk_queue_max_hw_sectors(disk->queue, | |
1172 | ub->dev_info.rq_max_blocks << (ub->bs_shift - 9)); | |
1173 | disk->queue->limits.discard_granularity = PAGE_SIZE; | |
1174 | blk_queue_max_discard_sectors(disk->queue, UINT_MAX >> 9); | |
1175 | blk_queue_max_write_zeroes_sectors(disk->queue, UINT_MAX >> 9); | |
1176 | ||
1177 | set_capacity(disk, ub->dev_info.dev_blocks << (ub->bs_shift - 9)); | |
1178 | ||
34d8f2be | 1179 | ub->dev_info.ublksrv_pid = ublksrv_pid; |
6d9e6dfd CH |
1180 | ub->ub_disk = disk; |
1181 | get_device(&ub->cdev_dev); | |
1182 | ret = add_disk(disk); | |
1183 | if (ret) { | |
1184 | put_disk(disk); | |
34d8f2be | 1185 | goto out_unlock; |
6d9e6dfd CH |
1186 | } |
1187 | set_bit(UB_STATE_USED, &ub->state); | |
34d8f2be CH |
1188 | ub->dev_info.state = UBLK_S_DEV_LIVE; |
1189 | out_unlock: | |
1190 | mutex_unlock(&ub->mutex); | |
1191 | ublk_put_device(ub); | |
71f28f31 ML |
1192 | return ret; |
1193 | } | |
1194 | ||
71f28f31 ML |
1195 | static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd) |
1196 | { | |
1197 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1198 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
71f28f31 | 1199 | struct ublk_device *ub; |
c50061f0 | 1200 | cpumask_var_t cpumask; |
71f28f31 ML |
1201 | unsigned long queue; |
1202 | unsigned int retlen; | |
c50061f0 | 1203 | unsigned int i; |
f2450f8a | 1204 | int ret = -EINVAL; |
34d8f2be CH |
1205 | |
1206 | if (header->len * BITS_PER_BYTE < nr_cpu_ids) | |
1207 | return -EINVAL; | |
1208 | if (header->len & (sizeof(unsigned long)-1)) | |
1209 | return -EINVAL; | |
1210 | if (!header->addr) | |
1211 | return -EINVAL; | |
71f28f31 ML |
1212 | |
1213 | ub = ublk_get_device_from_id(header->dev_id); | |
1214 | if (!ub) | |
c50061f0 | 1215 | return -EINVAL; |
71f28f31 | 1216 | |
71f28f31 ML |
1217 | queue = header->data[0]; |
1218 | if (queue >= ub->dev_info.nr_hw_queues) | |
c50061f0 | 1219 | goto out_put_device; |
71f28f31 | 1220 | |
c50061f0 CH |
1221 | ret = -ENOMEM; |
1222 | if (!zalloc_cpumask_var(&cpumask, GFP_KERNEL)) | |
1223 | goto out_put_device; | |
1224 | ||
1225 | for_each_possible_cpu(i) { | |
1226 | if (ub->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[i] == queue) | |
1227 | cpumask_set_cpu(i, cpumask); | |
71f28f31 | 1228 | } |
c50061f0 CH |
1229 | |
1230 | ret = -EFAULT; | |
1231 | retlen = min_t(unsigned short, header->len, cpumask_size()); | |
1232 | if (copy_to_user(argp, cpumask, retlen)) | |
1233 | goto out_free_cpumask; | |
1234 | if (retlen != header->len && | |
1235 | clear_user(argp + retlen, header->len - retlen)) | |
1236 | goto out_free_cpumask; | |
1237 | ||
71f28f31 | 1238 | ret = 0; |
c50061f0 CH |
1239 | out_free_cpumask: |
1240 | free_cpumask_var(cpumask); | |
1241 | out_put_device: | |
1242 | ublk_put_device(ub); | |
71f28f31 ML |
1243 | return ret; |
1244 | } | |
1245 | ||
34d8f2be | 1246 | static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info) |
71f28f31 | 1247 | { |
34d8f2be CH |
1248 | pr_devel("%s: dev id %d flags %llx\n", __func__, |
1249 | info->dev_id, info->flags[0]); | |
1250 | pr_devel("\t nr_hw_queues %d queue_depth %d block size %d dev_capacity %lld\n", | |
1251 | info->nr_hw_queues, info->queue_depth, | |
1252 | info->block_size, info->dev_blocks); | |
1253 | } | |
1254 | ||
1255 | static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) | |
1256 | { | |
1257 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1258 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
1259 | struct ublksrv_ctrl_dev_info info; | |
71f28f31 | 1260 | struct ublk_device *ub; |
34d8f2be CH |
1261 | int ret = -EINVAL; |
1262 | ||
1263 | if (header->len < sizeof(info) || !header->addr) | |
1264 | return -EINVAL; | |
1265 | if (header->queue_id != (u16)-1) { | |
1266 | pr_warn("%s: queue_id is wrong %x\n", | |
1267 | __func__, header->queue_id); | |
1268 | return -EINVAL; | |
1269 | } | |
1270 | if (copy_from_user(&info, argp, sizeof(info))) | |
1271 | return -EFAULT; | |
1272 | ublk_dump_dev_info(&info); | |
1273 | if (header->dev_id != info.dev_id) { | |
1274 | pr_warn("%s: dev id not match %u %u\n", | |
1275 | __func__, header->dev_id, info.dev_id); | |
1276 | return -EINVAL; | |
1277 | } | |
71f28f31 ML |
1278 | |
1279 | ret = mutex_lock_killable(&ublk_ctl_mutex); | |
1280 | if (ret) | |
1281 | return ret; | |
1282 | ||
cfee7e4d CH |
1283 | ret = -ENOMEM; |
1284 | ub = kzalloc(sizeof(*ub), GFP_KERNEL); | |
1285 | if (!ub) | |
1286 | goto out_unlock; | |
fa9482e0 CH |
1287 | mutex_init(&ub->mutex); |
1288 | spin_lock_init(&ub->mm_lock); | |
1289 | INIT_WORK(&ub->stop_work, ublk_stop_work_fn); | |
1290 | INIT_DELAYED_WORK(&ub->monitor_work, ublk_daemon_monitor_work); | |
cfee7e4d | 1291 | |
fa9482e0 CH |
1292 | ret = ublk_alloc_dev_number(ub, header->dev_id); |
1293 | if (ret < 0) | |
1294 | goto out_free_ub; | |
71f28f31 | 1295 | |
34d8f2be | 1296 | memcpy(&ub->dev_info, &info, sizeof(info)); |
71f28f31 | 1297 | |
34d8f2be CH |
1298 | /* update device id */ |
1299 | ub->dev_info.dev_id = ub->ub_number; | |
1300 | ||
fa9482e0 CH |
1301 | /* We are not ready to support zero copy */ |
1302 | ub->dev_info.flags[0] &= ~UBLK_F_SUPPORT_ZERO_COPY; | |
1303 | ||
1304 | ub->bs_shift = ilog2(ub->dev_info.block_size); | |
1305 | ub->dev_info.nr_hw_queues = min_t(unsigned int, | |
1306 | ub->dev_info.nr_hw_queues, nr_cpu_ids); | |
1307 | ublk_align_max_io_size(ub); | |
1308 | ||
1309 | ret = ublk_init_queues(ub); | |
34d8f2be | 1310 | if (ret) |
fa9482e0 | 1311 | goto out_free_dev_number; |
34d8f2be | 1312 | |
fa9482e0 CH |
1313 | ret = ublk_add_tag_set(ub); |
1314 | if (ret) | |
1315 | goto out_deinit_queues; | |
1316 | ||
1317 | ret = -EFAULT; | |
1318 | if (copy_to_user(argp, &ub->dev_info, sizeof(info))) | |
1319 | goto out_free_tag_set; | |
1320 | ||
1321 | /* | |
1322 | * Add the char dev so that ublksrv daemon can be setup. | |
1323 | * ublk_add_chdev() will cleanup everything if it fails. | |
1324 | */ | |
1325 | ret = ublk_add_chdev(ub); | |
1326 | goto out_unlock; | |
1327 | ||
1328 | out_free_tag_set: | |
1329 | blk_mq_free_tag_set(&ub->tag_set); | |
1330 | out_deinit_queues: | |
1331 | ublk_deinit_queues(ub); | |
1332 | out_free_dev_number: | |
1333 | ublk_free_dev_number(ub); | |
1334 | out_free_ub: | |
1335 | mutex_destroy(&ub->mutex); | |
1336 | kfree(ub); | |
34d8f2be | 1337 | out_unlock: |
71f28f31 | 1338 | mutex_unlock(&ublk_ctl_mutex); |
71f28f31 ML |
1339 | return ret; |
1340 | } | |
1341 | ||
1342 | static inline bool ublk_idr_freed(int id) | |
1343 | { | |
1344 | void *ptr; | |
1345 | ||
1346 | spin_lock(&ublk_idr_lock); | |
1347 | ptr = idr_find(&ublk_index_idr, id); | |
1348 | spin_unlock(&ublk_idr_lock); | |
1349 | ||
1350 | return ptr == NULL; | |
1351 | } | |
1352 | ||
1353 | static int ublk_ctrl_del_dev(int idx) | |
1354 | { | |
1355 | struct ublk_device *ub; | |
1356 | int ret; | |
1357 | ||
1358 | ret = mutex_lock_killable(&ublk_ctl_mutex); | |
1359 | if (ret) | |
1360 | return ret; | |
1361 | ||
1362 | ub = ublk_get_device_from_id(idx); | |
1363 | if (ub) { | |
1364 | ublk_remove(ub); | |
1365 | ublk_put_device(ub); | |
1366 | ret = 0; | |
1367 | } else { | |
1368 | ret = -ENODEV; | |
1369 | } | |
1370 | ||
1371 | /* | |
1372 | * Wait until the idr is removed, then it can be reused after | |
1373 | * DEL_DEV command is returned. | |
1374 | */ | |
1375 | if (!ret) | |
1376 | wait_event(ublk_idr_wq, ublk_idr_freed(idx)); | |
1377 | mutex_unlock(&ublk_ctl_mutex); | |
1378 | ||
1379 | return ret; | |
1380 | } | |
1381 | ||
71f28f31 ML |
1382 | static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd) |
1383 | { | |
1384 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1385 | ||
1386 | pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n", | |
1387 | __func__, cmd->cmd_op, header->dev_id, header->queue_id, | |
1388 | header->data[0], header->addr, header->len); | |
1389 | } | |
1390 | ||
34d8f2be | 1391 | static int ublk_ctrl_stop_dev(struct io_uring_cmd *cmd) |
71f28f31 ML |
1392 | { |
1393 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
34d8f2be | 1394 | struct ublk_device *ub; |
71f28f31 | 1395 | |
34d8f2be CH |
1396 | ub = ublk_get_device_from_id(header->dev_id); |
1397 | if (!ub) | |
1398 | return -EINVAL; | |
71f28f31 | 1399 | |
34d8f2be CH |
1400 | ublk_stop_dev(ub); |
1401 | cancel_work_sync(&ub->stop_work); | |
71f28f31 | 1402 | |
34d8f2be | 1403 | ublk_put_device(ub); |
71f28f31 ML |
1404 | return 0; |
1405 | } | |
1406 | ||
34d8f2be | 1407 | static int ublk_ctrl_get_dev_info(struct io_uring_cmd *cmd) |
71f28f31 ML |
1408 | { |
1409 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1410 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
71f28f31 | 1411 | struct ublk_device *ub; |
34d8f2be CH |
1412 | int ret = 0; |
1413 | ||
1414 | if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr) | |
1415 | return -EINVAL; | |
1416 | ||
1417 | ub = ublk_get_device_from_id(header->dev_id); | |
1418 | if (!ub) | |
1419 | return -EINVAL; | |
1420 | ||
1421 | if (copy_to_user(argp, &ub->dev_info, sizeof(ub->dev_info))) | |
1422 | ret = -EFAULT; | |
1423 | ublk_put_device(ub); | |
1424 | ||
1425 | return ret; | |
1426 | } | |
1427 | ||
1428 | static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, | |
1429 | unsigned int issue_flags) | |
1430 | { | |
1431 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
71f28f31 ML |
1432 | int ret = -EINVAL; |
1433 | ||
1434 | ublk_ctrl_cmd_dump(cmd); | |
1435 | ||
1436 | if (!(issue_flags & IO_URING_F_SQE128)) | |
1437 | goto out; | |
1438 | ||
34d8f2be CH |
1439 | ret = -EPERM; |
1440 | if (!capable(CAP_SYS_ADMIN)) | |
71f28f31 ML |
1441 | goto out; |
1442 | ||
1443 | ret = -ENODEV; | |
34d8f2be | 1444 | switch (cmd->cmd_op) { |
71f28f31 | 1445 | case UBLK_CMD_START_DEV: |
34d8f2be | 1446 | ret = ublk_ctrl_start_dev(cmd); |
71f28f31 ML |
1447 | break; |
1448 | case UBLK_CMD_STOP_DEV: | |
34d8f2be | 1449 | ret = ublk_ctrl_stop_dev(cmd); |
71f28f31 ML |
1450 | break; |
1451 | case UBLK_CMD_GET_DEV_INFO: | |
34d8f2be | 1452 | ret = ublk_ctrl_get_dev_info(cmd); |
71f28f31 ML |
1453 | break; |
1454 | case UBLK_CMD_ADD_DEV: | |
34d8f2be | 1455 | ret = ublk_ctrl_add_dev(cmd); |
71f28f31 ML |
1456 | break; |
1457 | case UBLK_CMD_DEL_DEV: | |
1458 | ret = ublk_ctrl_del_dev(header->dev_id); | |
1459 | break; | |
1460 | case UBLK_CMD_GET_QUEUE_AFFINITY: | |
1461 | ret = ublk_ctrl_get_queue_affinity(cmd); | |
1462 | break; | |
1463 | default: | |
1464 | break; | |
6b1439d2 | 1465 | } |
71f28f31 ML |
1466 | out: |
1467 | io_uring_cmd_done(cmd, ret, 0); | |
1468 | pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n", | |
1469 | __func__, ret, cmd->cmd_op, header->dev_id, header->queue_id); | |
1470 | return -EIOCBQUEUED; | |
1471 | } | |
1472 | ||
1473 | static const struct file_operations ublk_ctl_fops = { | |
1474 | .open = nonseekable_open, | |
1475 | .uring_cmd = ublk_ctrl_uring_cmd, | |
1476 | .owner = THIS_MODULE, | |
1477 | .llseek = noop_llseek, | |
1478 | }; | |
1479 | ||
1480 | static struct miscdevice ublk_misc = { | |
1481 | .minor = MISC_DYNAMIC_MINOR, | |
1482 | .name = "ublk-control", | |
1483 | .fops = &ublk_ctl_fops, | |
1484 | }; | |
1485 | ||
1486 | static int __init ublk_init(void) | |
1487 | { | |
1488 | int ret; | |
1489 | ||
1490 | init_waitqueue_head(&ublk_idr_wq); | |
1491 | ||
1492 | ret = misc_register(&ublk_misc); | |
1493 | if (ret) | |
1494 | return ret; | |
1495 | ||
1496 | ret = alloc_chrdev_region(&ublk_chr_devt, 0, UBLK_MINORS, "ublk-char"); | |
1497 | if (ret) | |
1498 | goto unregister_mis; | |
1499 | ||
1500 | ublk_chr_class = class_create(THIS_MODULE, "ublk-char"); | |
1501 | if (IS_ERR(ublk_chr_class)) { | |
1502 | ret = PTR_ERR(ublk_chr_class); | |
1503 | goto free_chrdev_region; | |
1504 | } | |
1505 | return 0; | |
1506 | ||
1507 | free_chrdev_region: | |
1508 | unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); | |
1509 | unregister_mis: | |
1510 | misc_deregister(&ublk_misc); | |
1511 | return ret; | |
1512 | } | |
1513 | ||
1514 | static void __exit ublk_exit(void) | |
1515 | { | |
1516 | struct ublk_device *ub; | |
1517 | int id; | |
1518 | ||
1519 | class_destroy(ublk_chr_class); | |
1520 | ||
1521 | misc_deregister(&ublk_misc); | |
1522 | ||
1523 | idr_for_each_entry(&ublk_index_idr, ub, id) | |
1524 | ublk_remove(ub); | |
1525 | ||
1526 | idr_destroy(&ublk_index_idr); | |
1527 | unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); | |
1528 | } | |
1529 | ||
1530 | module_init(ublk_init); | |
1531 | module_exit(ublk_exit); | |
1532 | ||
1533 | MODULE_AUTHOR("Ming Lei <ming.lei@redhat.com>"); | |
1534 | MODULE_LICENSE("GPL"); |