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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 | ||
6d8c5afc ML |
49 | /* All UBLK_F_* have to be included into UBLK_F_ALL */ |
50 | #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY | UBLK_F_URING_CMD_COMP_IN_TASK) | |
51 | ||
0edb3696 ML |
52 | struct ublk_rq_data { |
53 | struct callback_head work; | |
54 | }; | |
55 | ||
71f28f31 ML |
56 | struct ublk_uring_cmd_pdu { |
57 | struct request *req; | |
58 | }; | |
59 | ||
60 | /* | |
61 | * io command is active: sqe cmd is received, and its cqe isn't done | |
62 | * | |
63 | * If the flag is set, the io command is owned by ublk driver, and waited | |
64 | * for incoming blk-mq request from the ublk block device. | |
65 | * | |
66 | * If the flag is cleared, the io command will be completed, and owned by | |
67 | * ublk server. | |
68 | */ | |
69 | #define UBLK_IO_FLAG_ACTIVE 0x01 | |
70 | ||
71 | /* | |
72 | * IO command is completed via cqe, and it is being handled by ublksrv, and | |
73 | * not committed yet | |
74 | * | |
75 | * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for | |
76 | * cross verification | |
77 | */ | |
78 | #define UBLK_IO_FLAG_OWNED_BY_SRV 0x02 | |
79 | ||
80 | /* | |
81 | * IO command is aborted, so this flag is set in case of | |
82 | * !UBLK_IO_FLAG_ACTIVE. | |
83 | * | |
84 | * After this flag is observed, any pending or new incoming request | |
85 | * associated with this io command will be failed immediately | |
86 | */ | |
87 | #define UBLK_IO_FLAG_ABORTED 0x04 | |
88 | ||
89 | struct ublk_io { | |
90 | /* userspace buffer address from io cmd */ | |
91 | __u64 addr; | |
92 | unsigned int flags; | |
93 | int res; | |
94 | ||
95 | struct io_uring_cmd *cmd; | |
96 | }; | |
97 | ||
98 | struct ublk_queue { | |
99 | int q_id; | |
100 | int q_depth; | |
101 | ||
0edb3696 | 102 | unsigned long flags; |
71f28f31 ML |
103 | struct task_struct *ubq_daemon; |
104 | char *io_cmd_buf; | |
105 | ||
106 | unsigned long io_addr; /* mapped vm address */ | |
107 | unsigned int max_io_sz; | |
108 | bool abort_work_pending; | |
109 | unsigned short nr_io_ready; /* how many ios setup */ | |
110 | struct ublk_device *dev; | |
111 | struct ublk_io ios[0]; | |
112 | }; | |
113 | ||
114 | #define UBLK_DAEMON_MONITOR_PERIOD (5 * HZ) | |
115 | ||
116 | struct ublk_device { | |
117 | struct gendisk *ub_disk; | |
71f28f31 ML |
118 | |
119 | char *__queues; | |
120 | ||
121 | unsigned short queue_size; | |
122 | unsigned short bs_shift; | |
123 | struct ublksrv_ctrl_dev_info dev_info; | |
124 | ||
125 | struct blk_mq_tag_set tag_set; | |
126 | ||
127 | struct cdev cdev; | |
128 | struct device cdev_dev; | |
129 | ||
8d9fdb60 DC |
130 | #define UB_STATE_OPEN 0 |
131 | #define UB_STATE_USED 1 | |
fa362045 | 132 | unsigned long state; |
71f28f31 ML |
133 | int ub_number; |
134 | ||
135 | struct mutex mutex; | |
136 | ||
e94eb459 | 137 | spinlock_t mm_lock; |
71f28f31 ML |
138 | struct mm_struct *mm; |
139 | ||
140 | struct completion completion; | |
141 | unsigned int nr_queues_ready; | |
142 | atomic_t nr_aborted_queues; | |
143 | ||
144 | /* | |
145 | * Our ubq->daemon may be killed without any notification, so | |
146 | * monitor each queue's daemon periodically | |
147 | */ | |
148 | struct delayed_work monitor_work; | |
149 | struct work_struct stop_work; | |
150 | }; | |
151 | ||
152 | static dev_t ublk_chr_devt; | |
153 | static struct class *ublk_chr_class; | |
154 | ||
155 | static DEFINE_IDR(ublk_index_idr); | |
156 | static DEFINE_SPINLOCK(ublk_idr_lock); | |
157 | static wait_queue_head_t ublk_idr_wq; /* wait until one idr is freed */ | |
158 | ||
159 | static DEFINE_MUTEX(ublk_ctl_mutex); | |
160 | ||
161 | static struct miscdevice ublk_misc; | |
162 | ||
0edb3696 ML |
163 | static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq) |
164 | { | |
165 | if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK) && | |
166 | !(ubq->flags & UBLK_F_URING_CMD_COMP_IN_TASK)) | |
167 | return true; | |
168 | return false; | |
169 | } | |
170 | ||
71f28f31 ML |
171 | static struct ublk_device *ublk_get_device(struct ublk_device *ub) |
172 | { | |
173 | if (kobject_get_unless_zero(&ub->cdev_dev.kobj)) | |
174 | return ub; | |
175 | return NULL; | |
176 | } | |
177 | ||
178 | static void ublk_put_device(struct ublk_device *ub) | |
179 | { | |
180 | put_device(&ub->cdev_dev); | |
181 | } | |
182 | ||
183 | static inline struct ublk_queue *ublk_get_queue(struct ublk_device *dev, | |
184 | int qid) | |
185 | { | |
186 | return (struct ublk_queue *)&(dev->__queues[qid * dev->queue_size]); | |
187 | } | |
188 | ||
189 | static inline bool ublk_rq_has_data(const struct request *rq) | |
190 | { | |
191 | return rq->bio && bio_has_data(rq->bio); | |
192 | } | |
193 | ||
194 | static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq, | |
195 | int tag) | |
196 | { | |
197 | return (struct ublksrv_io_desc *) | |
198 | &(ubq->io_cmd_buf[tag * sizeof(struct ublksrv_io_desc)]); | |
199 | } | |
200 | ||
201 | static inline char *ublk_queue_cmd_buf(struct ublk_device *ub, int q_id) | |
202 | { | |
203 | return ublk_get_queue(ub, q_id)->io_cmd_buf; | |
204 | } | |
205 | ||
206 | static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) | |
207 | { | |
208 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
209 | ||
210 | return round_up(ubq->q_depth * sizeof(struct ublksrv_io_desc), | |
211 | PAGE_SIZE); | |
212 | } | |
213 | ||
6d9e6dfd CH |
214 | static void ublk_free_disk(struct gendisk *disk) |
215 | { | |
216 | struct ublk_device *ub = disk->private_data; | |
217 | ||
218 | clear_bit(UB_STATE_USED, &ub->state); | |
219 | put_device(&ub->cdev_dev); | |
220 | } | |
221 | ||
71f28f31 ML |
222 | static const struct block_device_operations ub_fops = { |
223 | .owner = THIS_MODULE, | |
6d9e6dfd | 224 | .free_disk = ublk_free_disk, |
71f28f31 ML |
225 | }; |
226 | ||
227 | #define UBLK_MAX_PIN_PAGES 32 | |
228 | ||
229 | struct ublk_map_data { | |
230 | const struct ublk_queue *ubq; | |
231 | const struct request *rq; | |
232 | const struct ublk_io *io; | |
233 | unsigned max_bytes; | |
234 | }; | |
235 | ||
236 | struct ublk_io_iter { | |
237 | struct page *pages[UBLK_MAX_PIN_PAGES]; | |
238 | unsigned pg_off; /* offset in the 1st page in pages */ | |
239 | int nr_pages; /* how many page pointers in pages */ | |
240 | struct bio *bio; | |
241 | struct bvec_iter iter; | |
242 | }; | |
243 | ||
244 | static inline unsigned ublk_copy_io_pages(struct ublk_io_iter *data, | |
245 | unsigned max_bytes, bool to_vm) | |
246 | { | |
247 | const unsigned total = min_t(unsigned, max_bytes, | |
248 | PAGE_SIZE - data->pg_off + | |
249 | ((data->nr_pages - 1) << PAGE_SHIFT)); | |
250 | unsigned done = 0; | |
251 | unsigned pg_idx = 0; | |
252 | ||
253 | while (done < total) { | |
254 | struct bio_vec bv = bio_iter_iovec(data->bio, data->iter); | |
255 | const unsigned int bytes = min3(bv.bv_len, total - done, | |
256 | (unsigned)(PAGE_SIZE - data->pg_off)); | |
257 | void *bv_buf = bvec_kmap_local(&bv); | |
258 | void *pg_buf = kmap_local_page(data->pages[pg_idx]); | |
259 | ||
260 | if (to_vm) | |
261 | memcpy(pg_buf + data->pg_off, bv_buf, bytes); | |
262 | else | |
263 | memcpy(bv_buf, pg_buf + data->pg_off, bytes); | |
264 | ||
265 | kunmap_local(pg_buf); | |
266 | kunmap_local(bv_buf); | |
267 | ||
268 | /* advance page array */ | |
269 | data->pg_off += bytes; | |
270 | if (data->pg_off == PAGE_SIZE) { | |
271 | pg_idx += 1; | |
272 | data->pg_off = 0; | |
273 | } | |
274 | ||
275 | done += bytes; | |
276 | ||
277 | /* advance bio */ | |
278 | bio_advance_iter_single(data->bio, &data->iter, bytes); | |
279 | if (!data->iter.bi_size) { | |
280 | data->bio = data->bio->bi_next; | |
281 | if (data->bio == NULL) | |
282 | break; | |
283 | data->iter = data->bio->bi_iter; | |
284 | } | |
285 | } | |
286 | ||
287 | return done; | |
288 | } | |
289 | ||
290 | static inline int ublk_copy_user_pages(struct ublk_map_data *data, | |
291 | bool to_vm) | |
292 | { | |
293 | const unsigned int gup_flags = to_vm ? FOLL_WRITE : 0; | |
294 | const unsigned long start_vm = data->io->addr; | |
295 | unsigned int done = 0; | |
296 | struct ublk_io_iter iter = { | |
297 | .pg_off = start_vm & (PAGE_SIZE - 1), | |
298 | .bio = data->rq->bio, | |
299 | .iter = data->rq->bio->bi_iter, | |
300 | }; | |
301 | const unsigned int nr_pages = round_up(data->max_bytes + | |
302 | (start_vm & (PAGE_SIZE - 1)), PAGE_SIZE) >> PAGE_SHIFT; | |
303 | ||
304 | while (done < nr_pages) { | |
305 | const unsigned to_pin = min_t(unsigned, UBLK_MAX_PIN_PAGES, | |
306 | nr_pages - done); | |
307 | unsigned i, len; | |
308 | ||
309 | iter.nr_pages = get_user_pages_fast(start_vm + | |
310 | (done << PAGE_SHIFT), to_pin, gup_flags, | |
311 | iter.pages); | |
312 | if (iter.nr_pages <= 0) | |
313 | return done == 0 ? iter.nr_pages : done; | |
314 | len = ublk_copy_io_pages(&iter, data->max_bytes, to_vm); | |
315 | for (i = 0; i < iter.nr_pages; i++) { | |
316 | if (to_vm) | |
317 | set_page_dirty(iter.pages[i]); | |
318 | put_page(iter.pages[i]); | |
319 | } | |
320 | data->max_bytes -= len; | |
321 | done += iter.nr_pages; | |
322 | } | |
323 | ||
324 | return done; | |
325 | } | |
326 | ||
327 | static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req, | |
328 | struct ublk_io *io) | |
329 | { | |
330 | const unsigned int rq_bytes = blk_rq_bytes(req); | |
331 | /* | |
332 | * no zero copy, we delay copy WRITE request data into ublksrv | |
333 | * context and the big benefit is that pinning pages in current | |
334 | * context is pretty fast, see ublk_pin_user_pages | |
335 | */ | |
336 | if (req_op(req) != REQ_OP_WRITE && req_op(req) != REQ_OP_FLUSH) | |
337 | return rq_bytes; | |
338 | ||
339 | if (ublk_rq_has_data(req)) { | |
340 | struct ublk_map_data data = { | |
341 | .ubq = ubq, | |
342 | .rq = req, | |
343 | .io = io, | |
344 | .max_bytes = rq_bytes, | |
345 | }; | |
346 | ||
347 | ublk_copy_user_pages(&data, true); | |
348 | ||
349 | return rq_bytes - data.max_bytes; | |
350 | } | |
351 | return rq_bytes; | |
352 | } | |
353 | ||
354 | static int ublk_unmap_io(const struct ublk_queue *ubq, | |
355 | const struct request *req, | |
356 | struct ublk_io *io) | |
357 | { | |
358 | const unsigned int rq_bytes = blk_rq_bytes(req); | |
359 | ||
360 | if (req_op(req) == REQ_OP_READ && ublk_rq_has_data(req)) { | |
361 | struct ublk_map_data data = { | |
362 | .ubq = ubq, | |
363 | .rq = req, | |
364 | .io = io, | |
365 | .max_bytes = io->res, | |
366 | }; | |
367 | ||
368 | WARN_ON_ONCE(io->res > rq_bytes); | |
369 | ||
370 | ublk_copy_user_pages(&data, false); | |
371 | ||
372 | return io->res - data.max_bytes; | |
373 | } | |
374 | return rq_bytes; | |
375 | } | |
376 | ||
377 | static inline unsigned int ublk_req_build_flags(struct request *req) | |
378 | { | |
379 | unsigned flags = 0; | |
380 | ||
381 | if (req->cmd_flags & REQ_FAILFAST_DEV) | |
382 | flags |= UBLK_IO_F_FAILFAST_DEV; | |
383 | ||
384 | if (req->cmd_flags & REQ_FAILFAST_TRANSPORT) | |
385 | flags |= UBLK_IO_F_FAILFAST_TRANSPORT; | |
386 | ||
387 | if (req->cmd_flags & REQ_FAILFAST_DRIVER) | |
388 | flags |= UBLK_IO_F_FAILFAST_DRIVER; | |
389 | ||
390 | if (req->cmd_flags & REQ_META) | |
391 | flags |= UBLK_IO_F_META; | |
392 | ||
71f28f31 ML |
393 | if (req->cmd_flags & REQ_FUA) |
394 | flags |= UBLK_IO_F_FUA; | |
395 | ||
71f28f31 ML |
396 | if (req->cmd_flags & REQ_NOUNMAP) |
397 | flags |= UBLK_IO_F_NOUNMAP; | |
398 | ||
399 | if (req->cmd_flags & REQ_SWAP) | |
400 | flags |= UBLK_IO_F_SWAP; | |
401 | ||
402 | return flags; | |
403 | } | |
404 | ||
f2450f8a | 405 | static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req) |
71f28f31 ML |
406 | { |
407 | struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag); | |
408 | struct ublk_io *io = &ubq->ios[req->tag]; | |
409 | u32 ublk_op; | |
410 | ||
411 | switch (req_op(req)) { | |
412 | case REQ_OP_READ: | |
413 | ublk_op = UBLK_IO_OP_READ; | |
414 | break; | |
415 | case REQ_OP_WRITE: | |
416 | ublk_op = UBLK_IO_OP_WRITE; | |
417 | break; | |
418 | case REQ_OP_FLUSH: | |
419 | ublk_op = UBLK_IO_OP_FLUSH; | |
420 | break; | |
421 | case REQ_OP_DISCARD: | |
422 | ublk_op = UBLK_IO_OP_DISCARD; | |
423 | break; | |
424 | case REQ_OP_WRITE_ZEROES: | |
425 | ublk_op = UBLK_IO_OP_WRITE_ZEROES; | |
426 | break; | |
427 | default: | |
428 | return BLK_STS_IOERR; | |
429 | } | |
430 | ||
431 | /* need to translate since kernel may change */ | |
432 | iod->op_flags = ublk_op | ublk_req_build_flags(req); | |
433 | iod->nr_sectors = blk_rq_sectors(req); | |
434 | iod->start_sector = blk_rq_pos(req); | |
435 | iod->addr = io->addr; | |
436 | ||
437 | return BLK_STS_OK; | |
438 | } | |
439 | ||
440 | static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu( | |
441 | struct io_uring_cmd *ioucmd) | |
442 | { | |
443 | return (struct ublk_uring_cmd_pdu *)&ioucmd->pdu; | |
444 | } | |
445 | ||
446 | static bool ubq_daemon_is_dying(struct ublk_queue *ubq) | |
447 | { | |
448 | return ubq->ubq_daemon->flags & PF_EXITING; | |
449 | } | |
450 | ||
451 | /* todo: handle partial completion */ | |
452 | static void ublk_complete_rq(struct request *req) | |
453 | { | |
454 | struct ublk_queue *ubq = req->mq_hctx->driver_data; | |
455 | struct ublk_io *io = &ubq->ios[req->tag]; | |
456 | unsigned int unmapped_bytes; | |
457 | ||
458 | /* failed read IO if nothing is read */ | |
459 | if (!io->res && req_op(req) == REQ_OP_READ) | |
460 | io->res = -EIO; | |
461 | ||
462 | if (io->res < 0) { | |
463 | blk_mq_end_request(req, errno_to_blk_status(io->res)); | |
464 | return; | |
465 | } | |
466 | ||
467 | /* | |
468 | * FLUSH or DISCARD usually won't return bytes returned, so end them | |
469 | * directly. | |
470 | * | |
471 | * Both the two needn't unmap. | |
472 | */ | |
473 | if (req_op(req) != REQ_OP_READ && req_op(req) != REQ_OP_WRITE) { | |
474 | blk_mq_end_request(req, BLK_STS_OK); | |
475 | return; | |
476 | } | |
477 | ||
478 | /* for READ request, writing data in iod->addr to rq buffers */ | |
479 | unmapped_bytes = ublk_unmap_io(ubq, req, io); | |
480 | ||
481 | /* | |
482 | * Extremely impossible since we got data filled in just before | |
483 | * | |
484 | * Re-read simply for this unlikely case. | |
485 | */ | |
486 | if (unlikely(unmapped_bytes < io->res)) | |
487 | io->res = unmapped_bytes; | |
488 | ||
489 | if (blk_update_request(req, BLK_STS_OK, io->res)) | |
490 | blk_mq_requeue_request(req, true); | |
491 | else | |
492 | __blk_mq_end_request(req, BLK_STS_OK); | |
493 | } | |
494 | ||
495 | /* | |
496 | * __ublk_fail_req() may be called from abort context or ->ubq_daemon | |
497 | * context during exiting, so lock is required. | |
498 | * | |
499 | * Also aborting may not be started yet, keep in mind that one failed | |
500 | * request may be issued by block layer again. | |
501 | */ | |
502 | static void __ublk_fail_req(struct ublk_io *io, struct request *req) | |
503 | { | |
504 | WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); | |
505 | ||
506 | if (!(io->flags & UBLK_IO_FLAG_ABORTED)) { | |
507 | io->flags |= UBLK_IO_FLAG_ABORTED; | |
508 | blk_mq_end_request(req, BLK_STS_IOERR); | |
509 | } | |
510 | } | |
511 | ||
512 | #define UBLK_REQUEUE_DELAY_MS 3 | |
513 | ||
0edb3696 | 514 | static inline void __ublk_rq_task_work(struct request *req) |
71f28f31 | 515 | { |
71f28f31 | 516 | struct ublk_queue *ubq = req->mq_hctx->driver_data; |
0edb3696 | 517 | struct ublk_device *ub = ubq->dev; |
71f28f31 ML |
518 | int tag = req->tag; |
519 | struct ublk_io *io = &ubq->ios[tag]; | |
520 | bool task_exiting = current != ubq->ubq_daemon || | |
521 | (current->flags & PF_EXITING); | |
522 | unsigned int mapped_bytes; | |
523 | ||
524 | pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n", | |
525 | __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, | |
526 | ublk_get_iod(ubq, req->tag)->addr); | |
527 | ||
528 | if (unlikely(task_exiting)) { | |
529 | blk_mq_end_request(req, BLK_STS_IOERR); | |
530 | mod_delayed_work(system_wq, &ub->monitor_work, 0); | |
531 | return; | |
532 | } | |
533 | ||
534 | mapped_bytes = ublk_map_io(ubq, req, io); | |
535 | ||
536 | /* partially mapped, update io descriptor */ | |
537 | if (unlikely(mapped_bytes != blk_rq_bytes(req))) { | |
538 | /* | |
539 | * Nothing mapped, retry until we succeed. | |
540 | * | |
541 | * We may never succeed in mapping any bytes here because | |
542 | * of OOM. TODO: reserve one buffer with single page pinned | |
543 | * for providing forward progress guarantee. | |
544 | */ | |
545 | if (unlikely(!mapped_bytes)) { | |
546 | blk_mq_requeue_request(req, false); | |
547 | blk_mq_delay_kick_requeue_list(req->q, | |
548 | UBLK_REQUEUE_DELAY_MS); | |
549 | return; | |
550 | } | |
551 | ||
552 | ublk_get_iod(ubq, req->tag)->nr_sectors = | |
553 | mapped_bytes >> 9; | |
554 | } | |
555 | ||
556 | /* mark this cmd owned by ublksrv */ | |
557 | io->flags |= UBLK_IO_FLAG_OWNED_BY_SRV; | |
558 | ||
559 | /* | |
560 | * clear ACTIVE since we are done with this sqe/cmd slot | |
561 | * We can only accept io cmd in case of being not active. | |
562 | */ | |
563 | io->flags &= ~UBLK_IO_FLAG_ACTIVE; | |
564 | ||
565 | /* tell ublksrv one io request is coming */ | |
566 | io_uring_cmd_done(io->cmd, UBLK_IO_RES_OK, 0); | |
567 | } | |
568 | ||
0edb3696 ML |
569 | static void ublk_rq_task_work_cb(struct io_uring_cmd *cmd) |
570 | { | |
571 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); | |
572 | ||
573 | __ublk_rq_task_work(pdu->req); | |
574 | } | |
575 | ||
576 | static void ublk_rq_task_work_fn(struct callback_head *work) | |
577 | { | |
578 | struct ublk_rq_data *data = container_of(work, | |
579 | struct ublk_rq_data, work); | |
580 | struct request *req = blk_mq_rq_from_pdu(data); | |
581 | ||
582 | __ublk_rq_task_work(req); | |
583 | } | |
584 | ||
71f28f31 ML |
585 | static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, |
586 | const struct blk_mq_queue_data *bd) | |
587 | { | |
588 | struct ublk_queue *ubq = hctx->driver_data; | |
589 | struct request *rq = bd->rq; | |
71f28f31 ML |
590 | blk_status_t res; |
591 | ||
592 | /* fill iod to slot in io cmd buffer */ | |
593 | res = ublk_setup_iod(ubq, rq); | |
594 | if (unlikely(res != BLK_STS_OK)) | |
595 | return BLK_STS_IOERR; | |
596 | ||
597 | blk_mq_start_request(bd->rq); | |
598 | ||
599 | if (unlikely(ubq_daemon_is_dying(ubq))) { | |
0edb3696 | 600 | fail: |
71f28f31 ML |
601 | mod_delayed_work(system_wq, &ubq->dev->monitor_work, 0); |
602 | return BLK_STS_IOERR; | |
603 | } | |
604 | ||
0edb3696 ML |
605 | if (ublk_can_use_task_work(ubq)) { |
606 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq); | |
607 | enum task_work_notify_mode notify_mode = bd->last ? | |
608 | TWA_SIGNAL_NO_IPI : TWA_NONE; | |
609 | ||
610 | if (task_work_add(ubq->ubq_daemon, &data->work, notify_mode)) | |
611 | goto fail; | |
612 | } else { | |
613 | struct io_uring_cmd *cmd = ubq->ios[rq->tag].cmd; | |
614 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); | |
615 | ||
616 | pdu->req = rq; | |
617 | io_uring_cmd_complete_in_task(cmd, ublk_rq_task_work_cb); | |
618 | } | |
71f28f31 ML |
619 | |
620 | return BLK_STS_OK; | |
621 | } | |
622 | ||
0edb3696 ML |
623 | static void ublk_commit_rqs(struct blk_mq_hw_ctx *hctx) |
624 | { | |
625 | struct ublk_queue *ubq = hctx->driver_data; | |
626 | ||
627 | if (ublk_can_use_task_work(ubq)) | |
628 | __set_notify_signal(ubq->ubq_daemon); | |
629 | } | |
71f28f31 ML |
630 | |
631 | static int ublk_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data, | |
632 | unsigned int hctx_idx) | |
633 | { | |
cebbe577 | 634 | struct ublk_device *ub = driver_data; |
71f28f31 ML |
635 | struct ublk_queue *ubq = ublk_get_queue(ub, hctx->queue_num); |
636 | ||
637 | hctx->driver_data = ubq; | |
638 | return 0; | |
639 | } | |
640 | ||
0edb3696 ML |
641 | static int ublk_init_rq(struct blk_mq_tag_set *set, struct request *req, |
642 | unsigned int hctx_idx, unsigned int numa_node) | |
643 | { | |
644 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); | |
645 | ||
646 | init_task_work(&data->work, ublk_rq_task_work_fn); | |
647 | return 0; | |
648 | } | |
649 | ||
71f28f31 ML |
650 | static const struct blk_mq_ops ublk_mq_ops = { |
651 | .queue_rq = ublk_queue_rq, | |
0edb3696 | 652 | .commit_rqs = ublk_commit_rqs, |
71f28f31 | 653 | .init_hctx = ublk_init_hctx, |
0edb3696 | 654 | .init_request = ublk_init_rq, |
71f28f31 ML |
655 | }; |
656 | ||
657 | static int ublk_ch_open(struct inode *inode, struct file *filp) | |
658 | { | |
659 | struct ublk_device *ub = container_of(inode->i_cdev, | |
660 | struct ublk_device, cdev); | |
661 | ||
fa362045 CH |
662 | if (test_and_set_bit(UB_STATE_OPEN, &ub->state)) |
663 | return -EBUSY; | |
664 | filp->private_data = ub; | |
665 | return 0; | |
71f28f31 ML |
666 | } |
667 | ||
668 | static int ublk_ch_release(struct inode *inode, struct file *filp) | |
669 | { | |
670 | struct ublk_device *ub = filp->private_data; | |
671 | ||
fa362045 | 672 | clear_bit(UB_STATE_OPEN, &ub->state); |
71f28f31 ML |
673 | return 0; |
674 | } | |
675 | ||
676 | /* map pre-allocated per-queue cmd buffer to ublksrv daemon */ | |
677 | static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma) | |
678 | { | |
679 | struct ublk_device *ub = filp->private_data; | |
680 | size_t sz = vma->vm_end - vma->vm_start; | |
681 | unsigned max_sz = UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc); | |
682 | unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT; | |
683 | int q_id, ret = 0; | |
684 | ||
e94eb459 | 685 | spin_lock(&ub->mm_lock); |
71f28f31 ML |
686 | if (!ub->mm) |
687 | ub->mm = current->mm; | |
688 | if (current->mm != ub->mm) | |
689 | ret = -EINVAL; | |
e94eb459 | 690 | spin_unlock(&ub->mm_lock); |
71f28f31 ML |
691 | |
692 | if (ret) | |
693 | return ret; | |
694 | ||
695 | if (vma->vm_flags & VM_WRITE) | |
696 | return -EPERM; | |
697 | ||
698 | end = UBLKSRV_CMD_BUF_OFFSET + ub->dev_info.nr_hw_queues * max_sz; | |
699 | if (phys_off < UBLKSRV_CMD_BUF_OFFSET || phys_off >= end) | |
700 | return -EINVAL; | |
701 | ||
702 | q_id = (phys_off - UBLKSRV_CMD_BUF_OFFSET) / max_sz; | |
703 | pr_devel("%s: qid %d, pid %d, addr %lx pg_off %lx sz %lu\n", | |
704 | __func__, q_id, current->pid, vma->vm_start, | |
705 | phys_off, (unsigned long)sz); | |
706 | ||
707 | if (sz != ublk_queue_cmd_buf_size(ub, q_id)) | |
708 | return -EINVAL; | |
709 | ||
710 | pfn = virt_to_phys(ublk_queue_cmd_buf(ub, q_id)) >> PAGE_SHIFT; | |
711 | return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); | |
712 | } | |
713 | ||
714 | static void ublk_commit_completion(struct ublk_device *ub, | |
715 | struct ublksrv_io_cmd *ub_cmd) | |
716 | { | |
717 | u32 qid = ub_cmd->q_id, tag = ub_cmd->tag; | |
718 | struct ublk_queue *ubq = ublk_get_queue(ub, qid); | |
719 | struct ublk_io *io = &ubq->ios[tag]; | |
720 | struct request *req; | |
721 | ||
722 | /* now this cmd slot is owned by nbd driver */ | |
723 | io->flags &= ~UBLK_IO_FLAG_OWNED_BY_SRV; | |
724 | io->res = ub_cmd->result; | |
725 | ||
726 | /* find the io request and complete */ | |
727 | req = blk_mq_tag_to_rq(ub->tag_set.tags[qid], tag); | |
728 | ||
729 | if (req && likely(!blk_should_fake_timeout(req->q))) | |
730 | ublk_complete_rq(req); | |
731 | } | |
732 | ||
733 | /* | |
734 | * When ->ubq_daemon is exiting, either new request is ended immediately, | |
735 | * or any queued io command is drained, so it is safe to abort queue | |
736 | * lockless | |
737 | */ | |
738 | static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) | |
739 | { | |
740 | int i; | |
741 | ||
742 | if (!ublk_get_device(ub)) | |
743 | return; | |
744 | ||
745 | for (i = 0; i < ubq->q_depth; i++) { | |
746 | struct ublk_io *io = &ubq->ios[i]; | |
747 | ||
748 | if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) { | |
749 | struct request *rq; | |
750 | ||
751 | /* | |
752 | * Either we fail the request or ublk_rq_task_work_fn | |
753 | * will do it | |
754 | */ | |
755 | rq = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], i); | |
756 | if (rq) | |
757 | __ublk_fail_req(io, rq); | |
758 | } | |
759 | } | |
760 | ublk_put_device(ub); | |
761 | } | |
762 | ||
763 | static void ublk_daemon_monitor_work(struct work_struct *work) | |
764 | { | |
765 | struct ublk_device *ub = | |
766 | container_of(work, struct ublk_device, monitor_work.work); | |
767 | int i; | |
768 | ||
769 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) { | |
770 | struct ublk_queue *ubq = ublk_get_queue(ub, i); | |
771 | ||
772 | if (ubq_daemon_is_dying(ubq)) { | |
773 | schedule_work(&ub->stop_work); | |
774 | ||
775 | /* abort queue is for making forward progress */ | |
776 | ublk_abort_queue(ub, ubq); | |
777 | } | |
778 | } | |
779 | ||
780 | /* | |
781 | * We can't schedule monitor work after ublk_remove() is started. | |
782 | * | |
783 | * No need ub->mutex, monitor work are canceled after state is marked | |
784 | * as DEAD, so DEAD state is observed reliably. | |
785 | */ | |
786 | if (ub->dev_info.state != UBLK_S_DEV_DEAD) | |
787 | schedule_delayed_work(&ub->monitor_work, | |
788 | UBLK_DAEMON_MONITOR_PERIOD); | |
789 | } | |
790 | ||
791 | static void ublk_cancel_queue(struct ublk_queue *ubq) | |
792 | { | |
793 | int i; | |
794 | ||
795 | for (i = 0; i < ubq->q_depth; i++) { | |
796 | struct ublk_io *io = &ubq->ios[i]; | |
797 | ||
798 | if (io->flags & UBLK_IO_FLAG_ACTIVE) | |
799 | io_uring_cmd_done(io->cmd, UBLK_IO_RES_ABORT, 0); | |
800 | } | |
801 | } | |
802 | ||
803 | /* Cancel all pending commands, must be called after del_gendisk() returns */ | |
804 | static void ublk_cancel_dev(struct ublk_device *ub) | |
805 | { | |
806 | int i; | |
807 | ||
808 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) | |
809 | ublk_cancel_queue(ublk_get_queue(ub, i)); | |
810 | } | |
811 | ||
812 | static void ublk_stop_dev(struct ublk_device *ub) | |
813 | { | |
814 | mutex_lock(&ub->mutex); | |
6d9e6dfd | 815 | if (ub->dev_info.state != UBLK_S_DEV_LIVE) |
71f28f31 ML |
816 | goto unlock; |
817 | ||
818 | del_gendisk(ub->ub_disk); | |
819 | ub->dev_info.state = UBLK_S_DEV_DEAD; | |
820 | ub->dev_info.ublksrv_pid = -1; | |
821 | ublk_cancel_dev(ub); | |
6d9e6dfd CH |
822 | put_disk(ub->ub_disk); |
823 | ub->ub_disk = NULL; | |
71f28f31 ML |
824 | unlock: |
825 | mutex_unlock(&ub->mutex); | |
826 | cancel_delayed_work_sync(&ub->monitor_work); | |
827 | } | |
828 | ||
71f28f31 ML |
829 | static inline bool ublk_queue_ready(struct ublk_queue *ubq) |
830 | { | |
831 | return ubq->nr_io_ready == ubq->q_depth; | |
832 | } | |
833 | ||
834 | /* device can only be started after all IOs are ready */ | |
835 | static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq) | |
836 | { | |
837 | mutex_lock(&ub->mutex); | |
838 | ubq->nr_io_ready++; | |
839 | if (ublk_queue_ready(ubq)) { | |
840 | ubq->ubq_daemon = current; | |
841 | get_task_struct(ubq->ubq_daemon); | |
842 | ub->nr_queues_ready++; | |
843 | } | |
844 | if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues) | |
845 | complete_all(&ub->completion); | |
846 | mutex_unlock(&ub->mutex); | |
847 | } | |
848 | ||
849 | static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) | |
850 | { | |
851 | struct ublksrv_io_cmd *ub_cmd = (struct ublksrv_io_cmd *)cmd->cmd; | |
852 | struct ublk_device *ub = cmd->file->private_data; | |
853 | struct ublk_queue *ubq; | |
854 | struct ublk_io *io; | |
855 | u32 cmd_op = cmd->cmd_op; | |
856 | unsigned tag = ub_cmd->tag; | |
857 | int ret = -EINVAL; | |
858 | ||
859 | pr_devel("%s: received: cmd op %d queue %d tag %d result %d\n", | |
860 | __func__, cmd->cmd_op, ub_cmd->q_id, tag, | |
861 | ub_cmd->result); | |
862 | ||
863 | if (!(issue_flags & IO_URING_F_SQE128)) | |
864 | goto out; | |
865 | ||
866 | if (ub_cmd->q_id >= ub->dev_info.nr_hw_queues) | |
867 | goto out; | |
868 | ||
869 | ubq = ublk_get_queue(ub, ub_cmd->q_id); | |
870 | if (!ubq || ub_cmd->q_id != ubq->q_id) | |
871 | goto out; | |
872 | ||
873 | if (ubq->ubq_daemon && ubq->ubq_daemon != current) | |
874 | goto out; | |
875 | ||
876 | if (tag >= ubq->q_depth) | |
877 | goto out; | |
878 | ||
879 | io = &ubq->ios[tag]; | |
880 | ||
881 | /* there is pending io cmd, something must be wrong */ | |
882 | if (io->flags & UBLK_IO_FLAG_ACTIVE) { | |
883 | ret = -EBUSY; | |
884 | goto out; | |
885 | } | |
886 | ||
887 | switch (cmd_op) { | |
888 | case UBLK_IO_FETCH_REQ: | |
889 | /* UBLK_IO_FETCH_REQ is only allowed before queue is setup */ | |
890 | if (ublk_queue_ready(ubq)) { | |
891 | ret = -EBUSY; | |
892 | goto out; | |
893 | } | |
894 | /* | |
895 | * The io is being handled by server, so COMMIT_RQ is expected | |
896 | * instead of FETCH_REQ | |
897 | */ | |
898 | if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV) | |
899 | goto out; | |
900 | /* FETCH_RQ has to provide IO buffer */ | |
901 | if (!ub_cmd->addr) | |
902 | goto out; | |
903 | io->cmd = cmd; | |
904 | io->flags |= UBLK_IO_FLAG_ACTIVE; | |
905 | io->addr = ub_cmd->addr; | |
906 | ||
907 | ublk_mark_io_ready(ub, ubq); | |
908 | break; | |
909 | case UBLK_IO_COMMIT_AND_FETCH_REQ: | |
910 | /* FETCH_RQ has to provide IO buffer */ | |
911 | if (!ub_cmd->addr) | |
912 | goto out; | |
913 | if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) | |
914 | goto out; | |
915 | io->addr = ub_cmd->addr; | |
916 | io->flags |= UBLK_IO_FLAG_ACTIVE; | |
917 | io->cmd = cmd; | |
918 | ublk_commit_completion(ub, ub_cmd); | |
919 | break; | |
920 | default: | |
921 | goto out; | |
922 | } | |
923 | return -EIOCBQUEUED; | |
924 | ||
925 | out: | |
71f28f31 ML |
926 | io_uring_cmd_done(cmd, ret, 0); |
927 | pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n", | |
928 | __func__, cmd_op, tag, ret, io->flags); | |
929 | return -EIOCBQUEUED; | |
930 | } | |
931 | ||
932 | static const struct file_operations ublk_ch_fops = { | |
933 | .owner = THIS_MODULE, | |
934 | .open = ublk_ch_open, | |
935 | .release = ublk_ch_release, | |
936 | .llseek = no_llseek, | |
937 | .uring_cmd = ublk_ch_uring_cmd, | |
938 | .mmap = ublk_ch_mmap, | |
939 | }; | |
940 | ||
941 | static void ublk_deinit_queue(struct ublk_device *ub, int q_id) | |
942 | { | |
943 | int size = ublk_queue_cmd_buf_size(ub, q_id); | |
944 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
945 | ||
946 | if (ubq->ubq_daemon) | |
947 | put_task_struct(ubq->ubq_daemon); | |
948 | if (ubq->io_cmd_buf) | |
949 | free_pages((unsigned long)ubq->io_cmd_buf, get_order(size)); | |
950 | } | |
951 | ||
952 | static int ublk_init_queue(struct ublk_device *ub, int q_id) | |
953 | { | |
954 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
955 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO; | |
956 | void *ptr; | |
957 | int size; | |
958 | ||
6d8c5afc | 959 | ubq->flags = ub->dev_info.flags; |
71f28f31 ML |
960 | ubq->q_id = q_id; |
961 | ubq->q_depth = ub->dev_info.queue_depth; | |
962 | size = ublk_queue_cmd_buf_size(ub, q_id); | |
963 | ||
964 | ptr = (void *) __get_free_pages(gfp_flags, get_order(size)); | |
965 | if (!ptr) | |
966 | return -ENOMEM; | |
967 | ||
968 | ubq->io_cmd_buf = ptr; | |
969 | ubq->dev = ub; | |
970 | return 0; | |
971 | } | |
972 | ||
973 | static void ublk_deinit_queues(struct ublk_device *ub) | |
974 | { | |
975 | int nr_queues = ub->dev_info.nr_hw_queues; | |
976 | int i; | |
977 | ||
978 | if (!ub->__queues) | |
979 | return; | |
980 | ||
981 | for (i = 0; i < nr_queues; i++) | |
982 | ublk_deinit_queue(ub, i); | |
983 | kfree(ub->__queues); | |
984 | } | |
985 | ||
986 | static int ublk_init_queues(struct ublk_device *ub) | |
987 | { | |
988 | int nr_queues = ub->dev_info.nr_hw_queues; | |
989 | int depth = ub->dev_info.queue_depth; | |
990 | int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io); | |
991 | int i, ret = -ENOMEM; | |
992 | ||
993 | ub->queue_size = ubq_size; | |
994 | ub->__queues = kcalloc(nr_queues, ubq_size, GFP_KERNEL); | |
995 | if (!ub->__queues) | |
996 | return ret; | |
997 | ||
998 | for (i = 0; i < nr_queues; i++) { | |
999 | if (ublk_init_queue(ub, i)) | |
1000 | goto fail; | |
1001 | } | |
1002 | ||
1003 | init_completion(&ub->completion); | |
1004 | return 0; | |
1005 | ||
1006 | fail: | |
1007 | ublk_deinit_queues(ub); | |
1008 | return ret; | |
1009 | } | |
1010 | ||
fa9482e0 | 1011 | static int ublk_alloc_dev_number(struct ublk_device *ub, int idx) |
71f28f31 ML |
1012 | { |
1013 | int i = idx; | |
1014 | int err; | |
1015 | ||
1016 | spin_lock(&ublk_idr_lock); | |
1017 | /* allocate id, if @id >= 0, we're requesting that specific id */ | |
1018 | if (i >= 0) { | |
1019 | err = idr_alloc(&ublk_index_idr, ub, i, i + 1, GFP_NOWAIT); | |
1020 | if (err == -ENOSPC) | |
1021 | err = -EEXIST; | |
1022 | } else { | |
1023 | err = idr_alloc(&ublk_index_idr, ub, 0, 0, GFP_NOWAIT); | |
1024 | } | |
1025 | spin_unlock(&ublk_idr_lock); | |
1026 | ||
1027 | if (err >= 0) | |
1028 | ub->ub_number = err; | |
1029 | ||
1030 | return err; | |
1031 | } | |
1032 | ||
fa9482e0 | 1033 | static void ublk_free_dev_number(struct ublk_device *ub) |
71f28f31 ML |
1034 | { |
1035 | spin_lock(&ublk_idr_lock); | |
1036 | idr_remove(&ublk_index_idr, ub->ub_number); | |
1037 | wake_up_all(&ublk_idr_wq); | |
1038 | spin_unlock(&ublk_idr_lock); | |
71f28f31 ML |
1039 | } |
1040 | ||
1041 | static void ublk_cdev_rel(struct device *dev) | |
1042 | { | |
1043 | struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev); | |
1044 | ||
71f28f31 | 1045 | blk_mq_free_tag_set(&ub->tag_set); |
71f28f31 | 1046 | ublk_deinit_queues(ub); |
fa9482e0 CH |
1047 | ublk_free_dev_number(ub); |
1048 | mutex_destroy(&ub->mutex); | |
1049 | kfree(ub); | |
71f28f31 ML |
1050 | } |
1051 | ||
1052 | static int ublk_add_chdev(struct ublk_device *ub) | |
1053 | { | |
1054 | struct device *dev = &ub->cdev_dev; | |
1055 | int minor = ub->ub_number; | |
1056 | int ret; | |
1057 | ||
1058 | dev->parent = ublk_misc.this_device; | |
1059 | dev->devt = MKDEV(MAJOR(ublk_chr_devt), minor); | |
1060 | dev->class = ublk_chr_class; | |
1061 | dev->release = ublk_cdev_rel; | |
1062 | device_initialize(dev); | |
1063 | ||
1064 | ret = dev_set_name(dev, "ublkc%d", minor); | |
1065 | if (ret) | |
1066 | goto fail; | |
1067 | ||
1068 | cdev_init(&ub->cdev, &ublk_ch_fops); | |
1069 | ret = cdev_device_add(&ub->cdev, dev); | |
1070 | if (ret) | |
1071 | goto fail; | |
1072 | return 0; | |
1073 | fail: | |
1074 | put_device(dev); | |
1075 | return ret; | |
1076 | } | |
1077 | ||
1078 | static void ublk_stop_work_fn(struct work_struct *work) | |
1079 | { | |
1080 | struct ublk_device *ub = | |
1081 | container_of(work, struct ublk_device, stop_work); | |
1082 | ||
1083 | ublk_stop_dev(ub); | |
1084 | } | |
1085 | ||
6d9e6dfd CH |
1086 | /* align maximum I/O size to PAGE_SIZE */ |
1087 | static void ublk_align_max_io_size(struct ublk_device *ub) | |
71f28f31 | 1088 | { |
6d9e6dfd | 1089 | unsigned int max_rq_bytes = ub->dev_info.rq_max_blocks << ub->bs_shift; |
71f28f31 | 1090 | |
6d9e6dfd CH |
1091 | ub->dev_info.rq_max_blocks = |
1092 | round_down(max_rq_bytes, PAGE_SIZE) >> ub->bs_shift; | |
71f28f31 ML |
1093 | } |
1094 | ||
fa9482e0 | 1095 | static int ublk_add_tag_set(struct ublk_device *ub) |
71f28f31 | 1096 | { |
71f28f31 ML |
1097 | ub->tag_set.ops = &ublk_mq_ops; |
1098 | ub->tag_set.nr_hw_queues = ub->dev_info.nr_hw_queues; | |
1099 | ub->tag_set.queue_depth = ub->dev_info.queue_depth; | |
1100 | ub->tag_set.numa_node = NUMA_NO_NODE; | |
0edb3696 | 1101 | ub->tag_set.cmd_size = sizeof(struct ublk_rq_data); |
71f28f31 ML |
1102 | ub->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; |
1103 | ub->tag_set.driver_data = ub; | |
fa9482e0 | 1104 | return blk_mq_alloc_tag_set(&ub->tag_set); |
71f28f31 ML |
1105 | } |
1106 | ||
1107 | static void ublk_remove(struct ublk_device *ub) | |
1108 | { | |
34d8f2be CH |
1109 | ublk_stop_dev(ub); |
1110 | cancel_work_sync(&ub->stop_work); | |
71f28f31 ML |
1111 | cdev_device_del(&ub->cdev, &ub->cdev_dev); |
1112 | put_device(&ub->cdev_dev); | |
1113 | } | |
1114 | ||
1115 | static struct ublk_device *ublk_get_device_from_id(int idx) | |
1116 | { | |
1117 | struct ublk_device *ub = NULL; | |
1118 | ||
1119 | if (idx < 0) | |
1120 | return NULL; | |
1121 | ||
1122 | spin_lock(&ublk_idr_lock); | |
1123 | ub = idr_find(&ublk_index_idr, idx); | |
1124 | if (ub) | |
1125 | ub = ublk_get_device(ub); | |
1126 | spin_unlock(&ublk_idr_lock); | |
1127 | ||
1128 | return ub; | |
1129 | } | |
1130 | ||
34d8f2be | 1131 | static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd) |
71f28f31 ML |
1132 | { |
1133 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
71f28f31 ML |
1134 | int ublksrv_pid = (int)header->data[0]; |
1135 | unsigned long dev_blocks = header->data[1]; | |
34d8f2be | 1136 | struct ublk_device *ub; |
6d9e6dfd | 1137 | struct gendisk *disk; |
34d8f2be | 1138 | int ret = -EINVAL; |
71f28f31 ML |
1139 | |
1140 | if (ublksrv_pid <= 0) | |
34d8f2be CH |
1141 | return -EINVAL; |
1142 | ||
1143 | ub = ublk_get_device_from_id(header->dev_id); | |
1144 | if (!ub) | |
1145 | return -EINVAL; | |
71f28f31 ML |
1146 | |
1147 | wait_for_completion_interruptible(&ub->completion); | |
1148 | ||
1149 | schedule_delayed_work(&ub->monitor_work, UBLK_DAEMON_MONITOR_PERIOD); | |
1150 | ||
1151 | mutex_lock(&ub->mutex); | |
6d9e6dfd CH |
1152 | if (ub->dev_info.state == UBLK_S_DEV_LIVE || |
1153 | test_bit(UB_STATE_USED, &ub->state)) { | |
71f28f31 | 1154 | ret = -EEXIST; |
34d8f2be | 1155 | goto out_unlock; |
71f28f31 | 1156 | } |
71f28f31 | 1157 | |
34d8f2be | 1158 | /* We may get disk size updated */ |
6d9e6dfd | 1159 | if (dev_blocks) |
34d8f2be | 1160 | ub->dev_info.dev_blocks = dev_blocks; |
6d9e6dfd CH |
1161 | |
1162 | disk = blk_mq_alloc_disk(&ub->tag_set, ub); | |
1163 | if (IS_ERR(disk)) { | |
1164 | ret = PTR_ERR(disk); | |
1165 | goto out_unlock; | |
34d8f2be | 1166 | } |
6d9e6dfd CH |
1167 | sprintf(disk->disk_name, "ublkb%d", ub->ub_number); |
1168 | disk->fops = &ub_fops; | |
1169 | disk->private_data = ub; | |
1170 | ||
1171 | blk_queue_logical_block_size(disk->queue, ub->dev_info.block_size); | |
1172 | blk_queue_physical_block_size(disk->queue, ub->dev_info.block_size); | |
1173 | blk_queue_io_min(disk->queue, ub->dev_info.block_size); | |
1174 | blk_queue_max_hw_sectors(disk->queue, | |
1175 | ub->dev_info.rq_max_blocks << (ub->bs_shift - 9)); | |
1176 | disk->queue->limits.discard_granularity = PAGE_SIZE; | |
1177 | blk_queue_max_discard_sectors(disk->queue, UINT_MAX >> 9); | |
1178 | blk_queue_max_write_zeroes_sectors(disk->queue, UINT_MAX >> 9); | |
1179 | ||
1180 | set_capacity(disk, ub->dev_info.dev_blocks << (ub->bs_shift - 9)); | |
1181 | ||
34d8f2be | 1182 | ub->dev_info.ublksrv_pid = ublksrv_pid; |
6d9e6dfd CH |
1183 | ub->ub_disk = disk; |
1184 | get_device(&ub->cdev_dev); | |
1185 | ret = add_disk(disk); | |
1186 | if (ret) { | |
1187 | put_disk(disk); | |
34d8f2be | 1188 | goto out_unlock; |
6d9e6dfd CH |
1189 | } |
1190 | set_bit(UB_STATE_USED, &ub->state); | |
34d8f2be CH |
1191 | ub->dev_info.state = UBLK_S_DEV_LIVE; |
1192 | out_unlock: | |
1193 | mutex_unlock(&ub->mutex); | |
1194 | ublk_put_device(ub); | |
71f28f31 ML |
1195 | return ret; |
1196 | } | |
1197 | ||
71f28f31 ML |
1198 | static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd) |
1199 | { | |
1200 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1201 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
71f28f31 | 1202 | struct ublk_device *ub; |
c50061f0 | 1203 | cpumask_var_t cpumask; |
71f28f31 ML |
1204 | unsigned long queue; |
1205 | unsigned int retlen; | |
c50061f0 | 1206 | unsigned int i; |
f2450f8a | 1207 | int ret = -EINVAL; |
34d8f2be CH |
1208 | |
1209 | if (header->len * BITS_PER_BYTE < nr_cpu_ids) | |
1210 | return -EINVAL; | |
1211 | if (header->len & (sizeof(unsigned long)-1)) | |
1212 | return -EINVAL; | |
1213 | if (!header->addr) | |
1214 | return -EINVAL; | |
71f28f31 ML |
1215 | |
1216 | ub = ublk_get_device_from_id(header->dev_id); | |
1217 | if (!ub) | |
c50061f0 | 1218 | return -EINVAL; |
71f28f31 | 1219 | |
71f28f31 ML |
1220 | queue = header->data[0]; |
1221 | if (queue >= ub->dev_info.nr_hw_queues) | |
c50061f0 | 1222 | goto out_put_device; |
71f28f31 | 1223 | |
c50061f0 CH |
1224 | ret = -ENOMEM; |
1225 | if (!zalloc_cpumask_var(&cpumask, GFP_KERNEL)) | |
1226 | goto out_put_device; | |
1227 | ||
1228 | for_each_possible_cpu(i) { | |
1229 | if (ub->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[i] == queue) | |
1230 | cpumask_set_cpu(i, cpumask); | |
71f28f31 | 1231 | } |
c50061f0 CH |
1232 | |
1233 | ret = -EFAULT; | |
1234 | retlen = min_t(unsigned short, header->len, cpumask_size()); | |
1235 | if (copy_to_user(argp, cpumask, retlen)) | |
1236 | goto out_free_cpumask; | |
1237 | if (retlen != header->len && | |
1238 | clear_user(argp + retlen, header->len - retlen)) | |
1239 | goto out_free_cpumask; | |
1240 | ||
71f28f31 | 1241 | ret = 0; |
c50061f0 CH |
1242 | out_free_cpumask: |
1243 | free_cpumask_var(cpumask); | |
1244 | out_put_device: | |
1245 | ublk_put_device(ub); | |
71f28f31 ML |
1246 | return ret; |
1247 | } | |
1248 | ||
34d8f2be | 1249 | static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info) |
71f28f31 | 1250 | { |
34d8f2be | 1251 | pr_devel("%s: dev id %d flags %llx\n", __func__, |
6d8c5afc | 1252 | info->dev_id, info->flags); |
34d8f2be CH |
1253 | pr_devel("\t nr_hw_queues %d queue_depth %d block size %d dev_capacity %lld\n", |
1254 | info->nr_hw_queues, info->queue_depth, | |
1255 | info->block_size, info->dev_blocks); | |
1256 | } | |
1257 | ||
1258 | static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) | |
1259 | { | |
1260 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1261 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
1262 | struct ublksrv_ctrl_dev_info info; | |
71f28f31 | 1263 | struct ublk_device *ub; |
34d8f2be CH |
1264 | int ret = -EINVAL; |
1265 | ||
1266 | if (header->len < sizeof(info) || !header->addr) | |
1267 | return -EINVAL; | |
1268 | if (header->queue_id != (u16)-1) { | |
1269 | pr_warn("%s: queue_id is wrong %x\n", | |
1270 | __func__, header->queue_id); | |
1271 | return -EINVAL; | |
1272 | } | |
1273 | if (copy_from_user(&info, argp, sizeof(info))) | |
1274 | return -EFAULT; | |
1275 | ublk_dump_dev_info(&info); | |
1276 | if (header->dev_id != info.dev_id) { | |
1277 | pr_warn("%s: dev id not match %u %u\n", | |
1278 | __func__, header->dev_id, info.dev_id); | |
1279 | return -EINVAL; | |
1280 | } | |
71f28f31 ML |
1281 | |
1282 | ret = mutex_lock_killable(&ublk_ctl_mutex); | |
1283 | if (ret) | |
1284 | return ret; | |
1285 | ||
cfee7e4d CH |
1286 | ret = -ENOMEM; |
1287 | ub = kzalloc(sizeof(*ub), GFP_KERNEL); | |
1288 | if (!ub) | |
1289 | goto out_unlock; | |
fa9482e0 CH |
1290 | mutex_init(&ub->mutex); |
1291 | spin_lock_init(&ub->mm_lock); | |
1292 | INIT_WORK(&ub->stop_work, ublk_stop_work_fn); | |
1293 | INIT_DELAYED_WORK(&ub->monitor_work, ublk_daemon_monitor_work); | |
cfee7e4d | 1294 | |
fa9482e0 CH |
1295 | ret = ublk_alloc_dev_number(ub, header->dev_id); |
1296 | if (ret < 0) | |
1297 | goto out_free_ub; | |
71f28f31 | 1298 | |
34d8f2be | 1299 | memcpy(&ub->dev_info, &info, sizeof(info)); |
71f28f31 | 1300 | |
34d8f2be CH |
1301 | /* update device id */ |
1302 | ub->dev_info.dev_id = ub->ub_number; | |
1303 | ||
6d8c5afc ML |
1304 | /* |
1305 | * 64bit flags will be copied back to userspace as feature | |
1306 | * negotiation result, so have to clear flags which driver | |
1307 | * doesn't support yet, then userspace can get correct flags | |
1308 | * (features) to handle. | |
1309 | */ | |
1310 | ub->dev_info.flags &= UBLK_F_ALL; | |
1311 | ||
fa9482e0 | 1312 | /* We are not ready to support zero copy */ |
6d8c5afc | 1313 | ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY; |
fa9482e0 CH |
1314 | |
1315 | ub->bs_shift = ilog2(ub->dev_info.block_size); | |
1316 | ub->dev_info.nr_hw_queues = min_t(unsigned int, | |
1317 | ub->dev_info.nr_hw_queues, nr_cpu_ids); | |
1318 | ublk_align_max_io_size(ub); | |
1319 | ||
1320 | ret = ublk_init_queues(ub); | |
34d8f2be | 1321 | if (ret) |
fa9482e0 | 1322 | goto out_free_dev_number; |
34d8f2be | 1323 | |
fa9482e0 CH |
1324 | ret = ublk_add_tag_set(ub); |
1325 | if (ret) | |
1326 | goto out_deinit_queues; | |
1327 | ||
1328 | ret = -EFAULT; | |
1329 | if (copy_to_user(argp, &ub->dev_info, sizeof(info))) | |
1330 | goto out_free_tag_set; | |
1331 | ||
1332 | /* | |
1333 | * Add the char dev so that ublksrv daemon can be setup. | |
1334 | * ublk_add_chdev() will cleanup everything if it fails. | |
1335 | */ | |
1336 | ret = ublk_add_chdev(ub); | |
1337 | goto out_unlock; | |
1338 | ||
1339 | out_free_tag_set: | |
1340 | blk_mq_free_tag_set(&ub->tag_set); | |
1341 | out_deinit_queues: | |
1342 | ublk_deinit_queues(ub); | |
1343 | out_free_dev_number: | |
1344 | ublk_free_dev_number(ub); | |
1345 | out_free_ub: | |
1346 | mutex_destroy(&ub->mutex); | |
1347 | kfree(ub); | |
34d8f2be | 1348 | out_unlock: |
71f28f31 | 1349 | mutex_unlock(&ublk_ctl_mutex); |
71f28f31 ML |
1350 | return ret; |
1351 | } | |
1352 | ||
1353 | static inline bool ublk_idr_freed(int id) | |
1354 | { | |
1355 | void *ptr; | |
1356 | ||
1357 | spin_lock(&ublk_idr_lock); | |
1358 | ptr = idr_find(&ublk_index_idr, id); | |
1359 | spin_unlock(&ublk_idr_lock); | |
1360 | ||
1361 | return ptr == NULL; | |
1362 | } | |
1363 | ||
1364 | static int ublk_ctrl_del_dev(int idx) | |
1365 | { | |
1366 | struct ublk_device *ub; | |
1367 | int ret; | |
1368 | ||
1369 | ret = mutex_lock_killable(&ublk_ctl_mutex); | |
1370 | if (ret) | |
1371 | return ret; | |
1372 | ||
1373 | ub = ublk_get_device_from_id(idx); | |
1374 | if (ub) { | |
1375 | ublk_remove(ub); | |
1376 | ublk_put_device(ub); | |
1377 | ret = 0; | |
1378 | } else { | |
1379 | ret = -ENODEV; | |
1380 | } | |
1381 | ||
1382 | /* | |
1383 | * Wait until the idr is removed, then it can be reused after | |
1384 | * DEL_DEV command is returned. | |
1385 | */ | |
1386 | if (!ret) | |
1387 | wait_event(ublk_idr_wq, ublk_idr_freed(idx)); | |
1388 | mutex_unlock(&ublk_ctl_mutex); | |
1389 | ||
1390 | return ret; | |
1391 | } | |
1392 | ||
71f28f31 ML |
1393 | static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd) |
1394 | { | |
1395 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1396 | ||
1397 | pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n", | |
1398 | __func__, cmd->cmd_op, header->dev_id, header->queue_id, | |
1399 | header->data[0], header->addr, header->len); | |
1400 | } | |
1401 | ||
34d8f2be | 1402 | static int ublk_ctrl_stop_dev(struct io_uring_cmd *cmd) |
71f28f31 ML |
1403 | { |
1404 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
34d8f2be | 1405 | struct ublk_device *ub; |
71f28f31 | 1406 | |
34d8f2be CH |
1407 | ub = ublk_get_device_from_id(header->dev_id); |
1408 | if (!ub) | |
1409 | return -EINVAL; | |
71f28f31 | 1410 | |
34d8f2be CH |
1411 | ublk_stop_dev(ub); |
1412 | cancel_work_sync(&ub->stop_work); | |
71f28f31 | 1413 | |
34d8f2be | 1414 | ublk_put_device(ub); |
71f28f31 ML |
1415 | return 0; |
1416 | } | |
1417 | ||
34d8f2be | 1418 | static int ublk_ctrl_get_dev_info(struct io_uring_cmd *cmd) |
71f28f31 ML |
1419 | { |
1420 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1421 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
71f28f31 | 1422 | struct ublk_device *ub; |
34d8f2be CH |
1423 | int ret = 0; |
1424 | ||
1425 | if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr) | |
1426 | return -EINVAL; | |
1427 | ||
1428 | ub = ublk_get_device_from_id(header->dev_id); | |
1429 | if (!ub) | |
1430 | return -EINVAL; | |
1431 | ||
1432 | if (copy_to_user(argp, &ub->dev_info, sizeof(ub->dev_info))) | |
1433 | ret = -EFAULT; | |
1434 | ublk_put_device(ub); | |
1435 | ||
1436 | return ret; | |
1437 | } | |
1438 | ||
1439 | static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, | |
1440 | unsigned int issue_flags) | |
1441 | { | |
1442 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
71f28f31 ML |
1443 | int ret = -EINVAL; |
1444 | ||
1445 | ublk_ctrl_cmd_dump(cmd); | |
1446 | ||
1447 | if (!(issue_flags & IO_URING_F_SQE128)) | |
1448 | goto out; | |
1449 | ||
34d8f2be CH |
1450 | ret = -EPERM; |
1451 | if (!capable(CAP_SYS_ADMIN)) | |
71f28f31 ML |
1452 | goto out; |
1453 | ||
1454 | ret = -ENODEV; | |
34d8f2be | 1455 | switch (cmd->cmd_op) { |
71f28f31 | 1456 | case UBLK_CMD_START_DEV: |
34d8f2be | 1457 | ret = ublk_ctrl_start_dev(cmd); |
71f28f31 ML |
1458 | break; |
1459 | case UBLK_CMD_STOP_DEV: | |
34d8f2be | 1460 | ret = ublk_ctrl_stop_dev(cmd); |
71f28f31 ML |
1461 | break; |
1462 | case UBLK_CMD_GET_DEV_INFO: | |
34d8f2be | 1463 | ret = ublk_ctrl_get_dev_info(cmd); |
71f28f31 ML |
1464 | break; |
1465 | case UBLK_CMD_ADD_DEV: | |
34d8f2be | 1466 | ret = ublk_ctrl_add_dev(cmd); |
71f28f31 ML |
1467 | break; |
1468 | case UBLK_CMD_DEL_DEV: | |
1469 | ret = ublk_ctrl_del_dev(header->dev_id); | |
1470 | break; | |
1471 | case UBLK_CMD_GET_QUEUE_AFFINITY: | |
1472 | ret = ublk_ctrl_get_queue_affinity(cmd); | |
1473 | break; | |
1474 | default: | |
1475 | break; | |
6b1439d2 | 1476 | } |
71f28f31 ML |
1477 | out: |
1478 | io_uring_cmd_done(cmd, ret, 0); | |
1479 | pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n", | |
1480 | __func__, ret, cmd->cmd_op, header->dev_id, header->queue_id); | |
1481 | return -EIOCBQUEUED; | |
1482 | } | |
1483 | ||
1484 | static const struct file_operations ublk_ctl_fops = { | |
1485 | .open = nonseekable_open, | |
1486 | .uring_cmd = ublk_ctrl_uring_cmd, | |
1487 | .owner = THIS_MODULE, | |
1488 | .llseek = noop_llseek, | |
1489 | }; | |
1490 | ||
1491 | static struct miscdevice ublk_misc = { | |
1492 | .minor = MISC_DYNAMIC_MINOR, | |
1493 | .name = "ublk-control", | |
1494 | .fops = &ublk_ctl_fops, | |
1495 | }; | |
1496 | ||
1497 | static int __init ublk_init(void) | |
1498 | { | |
1499 | int ret; | |
1500 | ||
1501 | init_waitqueue_head(&ublk_idr_wq); | |
1502 | ||
1503 | ret = misc_register(&ublk_misc); | |
1504 | if (ret) | |
1505 | return ret; | |
1506 | ||
1507 | ret = alloc_chrdev_region(&ublk_chr_devt, 0, UBLK_MINORS, "ublk-char"); | |
1508 | if (ret) | |
1509 | goto unregister_mis; | |
1510 | ||
1511 | ublk_chr_class = class_create(THIS_MODULE, "ublk-char"); | |
1512 | if (IS_ERR(ublk_chr_class)) { | |
1513 | ret = PTR_ERR(ublk_chr_class); | |
1514 | goto free_chrdev_region; | |
1515 | } | |
1516 | return 0; | |
1517 | ||
1518 | free_chrdev_region: | |
1519 | unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); | |
1520 | unregister_mis: | |
1521 | misc_deregister(&ublk_misc); | |
1522 | return ret; | |
1523 | } | |
1524 | ||
1525 | static void __exit ublk_exit(void) | |
1526 | { | |
1527 | struct ublk_device *ub; | |
1528 | int id; | |
1529 | ||
1530 | class_destroy(ublk_chr_class); | |
1531 | ||
1532 | misc_deregister(&ublk_misc); | |
1533 | ||
1534 | idr_for_each_entry(&ublk_index_idr, ub, id) | |
1535 | ublk_remove(ub); | |
1536 | ||
1537 | idr_destroy(&ublk_index_idr); | |
1538 | unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); | |
1539 | } | |
1540 | ||
1541 | module_init(ublk_init); | |
1542 | module_exit(ublk_exit); | |
1543 | ||
1544 | MODULE_AUTHOR("Ming Lei <ming.lei@redhat.com>"); | |
1545 | MODULE_LICENSE("GPL"); |