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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 | 49 | /* All UBLK_F_* have to be included into UBLK_F_ALL */ |
c86019ff Z |
50 | #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \ |
51 | | UBLK_F_URING_CMD_COMP_IN_TASK \ | |
52 | | UBLK_F_NEED_GET_DATA) | |
6d8c5afc | 53 | |
0aa73170 ML |
54 | /* All UBLK_PARAM_TYPE_* should be included here */ |
55 | #define UBLK_PARAM_TYPE_ALL (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD) | |
56 | ||
0edb3696 ML |
57 | struct ublk_rq_data { |
58 | struct callback_head work; | |
59 | }; | |
60 | ||
71f28f31 ML |
61 | struct ublk_uring_cmd_pdu { |
62 | struct request *req; | |
63 | }; | |
64 | ||
65 | /* | |
66 | * io command is active: sqe cmd is received, and its cqe isn't done | |
67 | * | |
68 | * If the flag is set, the io command is owned by ublk driver, and waited | |
69 | * for incoming blk-mq request from the ublk block device. | |
70 | * | |
71 | * If the flag is cleared, the io command will be completed, and owned by | |
72 | * ublk server. | |
73 | */ | |
74 | #define UBLK_IO_FLAG_ACTIVE 0x01 | |
75 | ||
76 | /* | |
77 | * IO command is completed via cqe, and it is being handled by ublksrv, and | |
78 | * not committed yet | |
79 | * | |
80 | * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for | |
81 | * cross verification | |
82 | */ | |
83 | #define UBLK_IO_FLAG_OWNED_BY_SRV 0x02 | |
84 | ||
85 | /* | |
86 | * IO command is aborted, so this flag is set in case of | |
87 | * !UBLK_IO_FLAG_ACTIVE. | |
88 | * | |
89 | * After this flag is observed, any pending or new incoming request | |
90 | * associated with this io command will be failed immediately | |
91 | */ | |
92 | #define UBLK_IO_FLAG_ABORTED 0x04 | |
93 | ||
c86019ff Z |
94 | /* |
95 | * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires | |
96 | * get data buffer address from ublksrv. | |
97 | * | |
98 | * Then, bio data could be copied into this data buffer for a WRITE request | |
99 | * after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset. | |
100 | */ | |
101 | #define UBLK_IO_FLAG_NEED_GET_DATA 0x08 | |
102 | ||
71f28f31 ML |
103 | struct ublk_io { |
104 | /* userspace buffer address from io cmd */ | |
105 | __u64 addr; | |
106 | unsigned int flags; | |
107 | int res; | |
108 | ||
109 | struct io_uring_cmd *cmd; | |
110 | }; | |
111 | ||
112 | struct ublk_queue { | |
113 | int q_id; | |
114 | int q_depth; | |
115 | ||
0edb3696 | 116 | unsigned long flags; |
71f28f31 ML |
117 | struct task_struct *ubq_daemon; |
118 | char *io_cmd_buf; | |
119 | ||
120 | unsigned long io_addr; /* mapped vm address */ | |
121 | unsigned int max_io_sz; | |
122 | bool abort_work_pending; | |
123 | unsigned short nr_io_ready; /* how many ios setup */ | |
124 | struct ublk_device *dev; | |
125 | struct ublk_io ios[0]; | |
126 | }; | |
127 | ||
128 | #define UBLK_DAEMON_MONITOR_PERIOD (5 * HZ) | |
129 | ||
130 | struct ublk_device { | |
131 | struct gendisk *ub_disk; | |
71f28f31 ML |
132 | |
133 | char *__queues; | |
134 | ||
135 | unsigned short queue_size; | |
71f28f31 ML |
136 | struct ublksrv_ctrl_dev_info dev_info; |
137 | ||
138 | struct blk_mq_tag_set tag_set; | |
139 | ||
140 | struct cdev cdev; | |
141 | struct device cdev_dev; | |
142 | ||
8d9fdb60 DC |
143 | #define UB_STATE_OPEN 0 |
144 | #define UB_STATE_USED 1 | |
fa362045 | 145 | unsigned long state; |
71f28f31 ML |
146 | int ub_number; |
147 | ||
148 | struct mutex mutex; | |
149 | ||
e94eb459 | 150 | spinlock_t mm_lock; |
71f28f31 ML |
151 | struct mm_struct *mm; |
152 | ||
0aa73170 ML |
153 | struct ublk_params params; |
154 | ||
71f28f31 ML |
155 | struct completion completion; |
156 | unsigned int nr_queues_ready; | |
157 | atomic_t nr_aborted_queues; | |
158 | ||
159 | /* | |
160 | * Our ubq->daemon may be killed without any notification, so | |
161 | * monitor each queue's daemon periodically | |
162 | */ | |
163 | struct delayed_work monitor_work; | |
164 | struct work_struct stop_work; | |
165 | }; | |
166 | ||
0aa73170 ML |
167 | /* header of ublk_params */ |
168 | struct ublk_params_header { | |
169 | __u32 len; | |
170 | __u32 types; | |
171 | }; | |
172 | ||
71f28f31 ML |
173 | static dev_t ublk_chr_devt; |
174 | static struct class *ublk_chr_class; | |
175 | ||
176 | static DEFINE_IDR(ublk_index_idr); | |
177 | static DEFINE_SPINLOCK(ublk_idr_lock); | |
178 | static wait_queue_head_t ublk_idr_wq; /* wait until one idr is freed */ | |
179 | ||
180 | static DEFINE_MUTEX(ublk_ctl_mutex); | |
181 | ||
182 | static struct miscdevice ublk_misc; | |
183 | ||
0aa73170 ML |
184 | static void ublk_dev_param_basic_apply(struct ublk_device *ub) |
185 | { | |
186 | struct request_queue *q = ub->ub_disk->queue; | |
187 | const struct ublk_param_basic *p = &ub->params.basic; | |
188 | ||
189 | blk_queue_logical_block_size(q, 1 << p->logical_bs_shift); | |
190 | blk_queue_physical_block_size(q, 1 << p->physical_bs_shift); | |
191 | blk_queue_io_min(q, 1 << p->io_min_shift); | |
192 | blk_queue_io_opt(q, 1 << p->io_opt_shift); | |
193 | ||
194 | blk_queue_write_cache(q, p->attrs & UBLK_ATTR_VOLATILE_CACHE, | |
195 | p->attrs & UBLK_ATTR_FUA); | |
196 | if (p->attrs & UBLK_ATTR_ROTATIONAL) | |
197 | blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); | |
198 | else | |
199 | blk_queue_flag_set(QUEUE_FLAG_NONROT, q); | |
200 | ||
201 | blk_queue_max_hw_sectors(q, p->max_sectors); | |
202 | blk_queue_chunk_sectors(q, p->chunk_sectors); | |
203 | blk_queue_virt_boundary(q, p->virt_boundary_mask); | |
204 | ||
205 | if (p->attrs & UBLK_ATTR_READ_ONLY) | |
206 | set_disk_ro(ub->ub_disk, true); | |
207 | ||
208 | set_capacity(ub->ub_disk, p->dev_sectors); | |
209 | } | |
210 | ||
211 | static void ublk_dev_param_discard_apply(struct ublk_device *ub) | |
212 | { | |
213 | struct request_queue *q = ub->ub_disk->queue; | |
214 | const struct ublk_param_discard *p = &ub->params.discard; | |
215 | ||
216 | q->limits.discard_alignment = p->discard_alignment; | |
217 | q->limits.discard_granularity = p->discard_granularity; | |
218 | blk_queue_max_discard_sectors(q, p->max_discard_sectors); | |
219 | blk_queue_max_write_zeroes_sectors(q, | |
220 | p->max_write_zeroes_sectors); | |
221 | blk_queue_max_discard_segments(q, p->max_discard_segments); | |
222 | } | |
223 | ||
224 | static int ublk_validate_params(const struct ublk_device *ub) | |
225 | { | |
226 | /* basic param is the only one which must be set */ | |
227 | if (ub->params.types & UBLK_PARAM_TYPE_BASIC) { | |
228 | const struct ublk_param_basic *p = &ub->params.basic; | |
229 | ||
230 | if (p->logical_bs_shift > PAGE_SHIFT) | |
231 | return -EINVAL; | |
232 | ||
233 | if (p->logical_bs_shift > p->physical_bs_shift) | |
234 | return -EINVAL; | |
235 | ||
4bf9cbf3 | 236 | if (p->max_sectors > (ub->dev_info.max_io_buf_bytes >> 9)) |
0aa73170 ML |
237 | return -EINVAL; |
238 | } else | |
239 | return -EINVAL; | |
240 | ||
241 | if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) { | |
242 | const struct ublk_param_discard *p = &ub->params.discard; | |
243 | ||
244 | /* So far, only support single segment discard */ | |
245 | if (p->max_discard_sectors && p->max_discard_segments != 1) | |
246 | return -EINVAL; | |
247 | ||
248 | if (!p->discard_granularity) | |
249 | return -EINVAL; | |
250 | } | |
251 | ||
252 | return 0; | |
253 | } | |
254 | ||
255 | static int ublk_apply_params(struct ublk_device *ub) | |
256 | { | |
257 | if (!(ub->params.types & UBLK_PARAM_TYPE_BASIC)) | |
258 | return -EINVAL; | |
259 | ||
260 | ublk_dev_param_basic_apply(ub); | |
261 | ||
262 | if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) | |
263 | ublk_dev_param_discard_apply(ub); | |
264 | ||
265 | return 0; | |
266 | } | |
267 | ||
0edb3696 ML |
268 | static inline bool ublk_can_use_task_work(const struct ublk_queue *ubq) |
269 | { | |
270 | if (IS_BUILTIN(CONFIG_BLK_DEV_UBLK) && | |
271 | !(ubq->flags & UBLK_F_URING_CMD_COMP_IN_TASK)) | |
272 | return true; | |
273 | return false; | |
274 | } | |
275 | ||
c86019ff Z |
276 | static inline bool ublk_need_get_data(const struct ublk_queue *ubq) |
277 | { | |
278 | if (ubq->flags & UBLK_F_NEED_GET_DATA) | |
279 | return true; | |
280 | return false; | |
281 | } | |
282 | ||
71f28f31 ML |
283 | static struct ublk_device *ublk_get_device(struct ublk_device *ub) |
284 | { | |
285 | if (kobject_get_unless_zero(&ub->cdev_dev.kobj)) | |
286 | return ub; | |
287 | return NULL; | |
288 | } | |
289 | ||
290 | static void ublk_put_device(struct ublk_device *ub) | |
291 | { | |
292 | put_device(&ub->cdev_dev); | |
293 | } | |
294 | ||
295 | static inline struct ublk_queue *ublk_get_queue(struct ublk_device *dev, | |
296 | int qid) | |
297 | { | |
298 | return (struct ublk_queue *)&(dev->__queues[qid * dev->queue_size]); | |
299 | } | |
300 | ||
301 | static inline bool ublk_rq_has_data(const struct request *rq) | |
302 | { | |
303 | return rq->bio && bio_has_data(rq->bio); | |
304 | } | |
305 | ||
306 | static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq, | |
307 | int tag) | |
308 | { | |
309 | return (struct ublksrv_io_desc *) | |
310 | &(ubq->io_cmd_buf[tag * sizeof(struct ublksrv_io_desc)]); | |
311 | } | |
312 | ||
313 | static inline char *ublk_queue_cmd_buf(struct ublk_device *ub, int q_id) | |
314 | { | |
315 | return ublk_get_queue(ub, q_id)->io_cmd_buf; | |
316 | } | |
317 | ||
318 | static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) | |
319 | { | |
320 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
321 | ||
322 | return round_up(ubq->q_depth * sizeof(struct ublksrv_io_desc), | |
323 | PAGE_SIZE); | |
324 | } | |
325 | ||
6d9e6dfd CH |
326 | static void ublk_free_disk(struct gendisk *disk) |
327 | { | |
328 | struct ublk_device *ub = disk->private_data; | |
329 | ||
330 | clear_bit(UB_STATE_USED, &ub->state); | |
331 | put_device(&ub->cdev_dev); | |
332 | } | |
333 | ||
71f28f31 ML |
334 | static const struct block_device_operations ub_fops = { |
335 | .owner = THIS_MODULE, | |
6d9e6dfd | 336 | .free_disk = ublk_free_disk, |
71f28f31 ML |
337 | }; |
338 | ||
339 | #define UBLK_MAX_PIN_PAGES 32 | |
340 | ||
341 | struct ublk_map_data { | |
342 | const struct ublk_queue *ubq; | |
343 | const struct request *rq; | |
344 | const struct ublk_io *io; | |
345 | unsigned max_bytes; | |
346 | }; | |
347 | ||
348 | struct ublk_io_iter { | |
349 | struct page *pages[UBLK_MAX_PIN_PAGES]; | |
350 | unsigned pg_off; /* offset in the 1st page in pages */ | |
351 | int nr_pages; /* how many page pointers in pages */ | |
352 | struct bio *bio; | |
353 | struct bvec_iter iter; | |
354 | }; | |
355 | ||
356 | static inline unsigned ublk_copy_io_pages(struct ublk_io_iter *data, | |
357 | unsigned max_bytes, bool to_vm) | |
358 | { | |
359 | const unsigned total = min_t(unsigned, max_bytes, | |
360 | PAGE_SIZE - data->pg_off + | |
361 | ((data->nr_pages - 1) << PAGE_SHIFT)); | |
362 | unsigned done = 0; | |
363 | unsigned pg_idx = 0; | |
364 | ||
365 | while (done < total) { | |
366 | struct bio_vec bv = bio_iter_iovec(data->bio, data->iter); | |
367 | const unsigned int bytes = min3(bv.bv_len, total - done, | |
368 | (unsigned)(PAGE_SIZE - data->pg_off)); | |
369 | void *bv_buf = bvec_kmap_local(&bv); | |
370 | void *pg_buf = kmap_local_page(data->pages[pg_idx]); | |
371 | ||
372 | if (to_vm) | |
373 | memcpy(pg_buf + data->pg_off, bv_buf, bytes); | |
374 | else | |
375 | memcpy(bv_buf, pg_buf + data->pg_off, bytes); | |
376 | ||
377 | kunmap_local(pg_buf); | |
378 | kunmap_local(bv_buf); | |
379 | ||
380 | /* advance page array */ | |
381 | data->pg_off += bytes; | |
382 | if (data->pg_off == PAGE_SIZE) { | |
383 | pg_idx += 1; | |
384 | data->pg_off = 0; | |
385 | } | |
386 | ||
387 | done += bytes; | |
388 | ||
389 | /* advance bio */ | |
390 | bio_advance_iter_single(data->bio, &data->iter, bytes); | |
391 | if (!data->iter.bi_size) { | |
392 | data->bio = data->bio->bi_next; | |
393 | if (data->bio == NULL) | |
394 | break; | |
395 | data->iter = data->bio->bi_iter; | |
396 | } | |
397 | } | |
398 | ||
399 | return done; | |
400 | } | |
401 | ||
402 | static inline int ublk_copy_user_pages(struct ublk_map_data *data, | |
403 | bool to_vm) | |
404 | { | |
405 | const unsigned int gup_flags = to_vm ? FOLL_WRITE : 0; | |
406 | const unsigned long start_vm = data->io->addr; | |
407 | unsigned int done = 0; | |
408 | struct ublk_io_iter iter = { | |
409 | .pg_off = start_vm & (PAGE_SIZE - 1), | |
410 | .bio = data->rq->bio, | |
411 | .iter = data->rq->bio->bi_iter, | |
412 | }; | |
413 | const unsigned int nr_pages = round_up(data->max_bytes + | |
414 | (start_vm & (PAGE_SIZE - 1)), PAGE_SIZE) >> PAGE_SHIFT; | |
415 | ||
416 | while (done < nr_pages) { | |
417 | const unsigned to_pin = min_t(unsigned, UBLK_MAX_PIN_PAGES, | |
418 | nr_pages - done); | |
419 | unsigned i, len; | |
420 | ||
421 | iter.nr_pages = get_user_pages_fast(start_vm + | |
422 | (done << PAGE_SHIFT), to_pin, gup_flags, | |
423 | iter.pages); | |
424 | if (iter.nr_pages <= 0) | |
425 | return done == 0 ? iter.nr_pages : done; | |
426 | len = ublk_copy_io_pages(&iter, data->max_bytes, to_vm); | |
427 | for (i = 0; i < iter.nr_pages; i++) { | |
428 | if (to_vm) | |
429 | set_page_dirty(iter.pages[i]); | |
430 | put_page(iter.pages[i]); | |
431 | } | |
432 | data->max_bytes -= len; | |
433 | done += iter.nr_pages; | |
434 | } | |
435 | ||
436 | return done; | |
437 | } | |
438 | ||
439 | static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req, | |
440 | struct ublk_io *io) | |
441 | { | |
442 | const unsigned int rq_bytes = blk_rq_bytes(req); | |
443 | /* | |
444 | * no zero copy, we delay copy WRITE request data into ublksrv | |
445 | * context and the big benefit is that pinning pages in current | |
446 | * context is pretty fast, see ublk_pin_user_pages | |
447 | */ | |
448 | if (req_op(req) != REQ_OP_WRITE && req_op(req) != REQ_OP_FLUSH) | |
449 | return rq_bytes; | |
450 | ||
451 | if (ublk_rq_has_data(req)) { | |
452 | struct ublk_map_data data = { | |
453 | .ubq = ubq, | |
454 | .rq = req, | |
455 | .io = io, | |
456 | .max_bytes = rq_bytes, | |
457 | }; | |
458 | ||
459 | ublk_copy_user_pages(&data, true); | |
460 | ||
461 | return rq_bytes - data.max_bytes; | |
462 | } | |
463 | return rq_bytes; | |
464 | } | |
465 | ||
466 | static int ublk_unmap_io(const struct ublk_queue *ubq, | |
467 | const struct request *req, | |
468 | struct ublk_io *io) | |
469 | { | |
470 | const unsigned int rq_bytes = blk_rq_bytes(req); | |
471 | ||
472 | if (req_op(req) == REQ_OP_READ && ublk_rq_has_data(req)) { | |
473 | struct ublk_map_data data = { | |
474 | .ubq = ubq, | |
475 | .rq = req, | |
476 | .io = io, | |
477 | .max_bytes = io->res, | |
478 | }; | |
479 | ||
480 | WARN_ON_ONCE(io->res > rq_bytes); | |
481 | ||
482 | ublk_copy_user_pages(&data, false); | |
483 | ||
484 | return io->res - data.max_bytes; | |
485 | } | |
486 | return rq_bytes; | |
487 | } | |
488 | ||
489 | static inline unsigned int ublk_req_build_flags(struct request *req) | |
490 | { | |
491 | unsigned flags = 0; | |
492 | ||
493 | if (req->cmd_flags & REQ_FAILFAST_DEV) | |
494 | flags |= UBLK_IO_F_FAILFAST_DEV; | |
495 | ||
496 | if (req->cmd_flags & REQ_FAILFAST_TRANSPORT) | |
497 | flags |= UBLK_IO_F_FAILFAST_TRANSPORT; | |
498 | ||
499 | if (req->cmd_flags & REQ_FAILFAST_DRIVER) | |
500 | flags |= UBLK_IO_F_FAILFAST_DRIVER; | |
501 | ||
502 | if (req->cmd_flags & REQ_META) | |
503 | flags |= UBLK_IO_F_META; | |
504 | ||
71f28f31 ML |
505 | if (req->cmd_flags & REQ_FUA) |
506 | flags |= UBLK_IO_F_FUA; | |
507 | ||
71f28f31 ML |
508 | if (req->cmd_flags & REQ_NOUNMAP) |
509 | flags |= UBLK_IO_F_NOUNMAP; | |
510 | ||
511 | if (req->cmd_flags & REQ_SWAP) | |
512 | flags |= UBLK_IO_F_SWAP; | |
513 | ||
514 | return flags; | |
515 | } | |
516 | ||
f2450f8a | 517 | static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req) |
71f28f31 ML |
518 | { |
519 | struct ublksrv_io_desc *iod = ublk_get_iod(ubq, req->tag); | |
520 | struct ublk_io *io = &ubq->ios[req->tag]; | |
521 | u32 ublk_op; | |
522 | ||
523 | switch (req_op(req)) { | |
524 | case REQ_OP_READ: | |
525 | ublk_op = UBLK_IO_OP_READ; | |
526 | break; | |
527 | case REQ_OP_WRITE: | |
528 | ublk_op = UBLK_IO_OP_WRITE; | |
529 | break; | |
530 | case REQ_OP_FLUSH: | |
531 | ublk_op = UBLK_IO_OP_FLUSH; | |
532 | break; | |
533 | case REQ_OP_DISCARD: | |
534 | ublk_op = UBLK_IO_OP_DISCARD; | |
535 | break; | |
536 | case REQ_OP_WRITE_ZEROES: | |
537 | ublk_op = UBLK_IO_OP_WRITE_ZEROES; | |
538 | break; | |
539 | default: | |
540 | return BLK_STS_IOERR; | |
541 | } | |
542 | ||
543 | /* need to translate since kernel may change */ | |
544 | iod->op_flags = ublk_op | ublk_req_build_flags(req); | |
545 | iod->nr_sectors = blk_rq_sectors(req); | |
546 | iod->start_sector = blk_rq_pos(req); | |
547 | iod->addr = io->addr; | |
548 | ||
549 | return BLK_STS_OK; | |
550 | } | |
551 | ||
552 | static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu( | |
553 | struct io_uring_cmd *ioucmd) | |
554 | { | |
555 | return (struct ublk_uring_cmd_pdu *)&ioucmd->pdu; | |
556 | } | |
557 | ||
966120b5 | 558 | static inline bool ubq_daemon_is_dying(struct ublk_queue *ubq) |
71f28f31 ML |
559 | { |
560 | return ubq->ubq_daemon->flags & PF_EXITING; | |
561 | } | |
562 | ||
563 | /* todo: handle partial completion */ | |
564 | static void ublk_complete_rq(struct request *req) | |
565 | { | |
566 | struct ublk_queue *ubq = req->mq_hctx->driver_data; | |
567 | struct ublk_io *io = &ubq->ios[req->tag]; | |
568 | unsigned int unmapped_bytes; | |
569 | ||
570 | /* failed read IO if nothing is read */ | |
571 | if (!io->res && req_op(req) == REQ_OP_READ) | |
572 | io->res = -EIO; | |
573 | ||
574 | if (io->res < 0) { | |
575 | blk_mq_end_request(req, errno_to_blk_status(io->res)); | |
576 | return; | |
577 | } | |
578 | ||
579 | /* | |
580 | * FLUSH or DISCARD usually won't return bytes returned, so end them | |
581 | * directly. | |
582 | * | |
583 | * Both the two needn't unmap. | |
584 | */ | |
585 | if (req_op(req) != REQ_OP_READ && req_op(req) != REQ_OP_WRITE) { | |
586 | blk_mq_end_request(req, BLK_STS_OK); | |
587 | return; | |
588 | } | |
589 | ||
590 | /* for READ request, writing data in iod->addr to rq buffers */ | |
591 | unmapped_bytes = ublk_unmap_io(ubq, req, io); | |
592 | ||
593 | /* | |
594 | * Extremely impossible since we got data filled in just before | |
595 | * | |
596 | * Re-read simply for this unlikely case. | |
597 | */ | |
598 | if (unlikely(unmapped_bytes < io->res)) | |
599 | io->res = unmapped_bytes; | |
600 | ||
601 | if (blk_update_request(req, BLK_STS_OK, io->res)) | |
602 | blk_mq_requeue_request(req, true); | |
603 | else | |
604 | __blk_mq_end_request(req, BLK_STS_OK); | |
605 | } | |
606 | ||
607 | /* | |
bb241747 Z |
608 | * Since __ublk_rq_task_work always fails requests immediately during |
609 | * exiting, __ublk_fail_req() is only called from abort context during | |
610 | * exiting. So lock is unnecessary. | |
71f28f31 ML |
611 | * |
612 | * Also aborting may not be started yet, keep in mind that one failed | |
613 | * request may be issued by block layer again. | |
614 | */ | |
615 | static void __ublk_fail_req(struct ublk_io *io, struct request *req) | |
616 | { | |
617 | WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); | |
618 | ||
619 | if (!(io->flags & UBLK_IO_FLAG_ABORTED)) { | |
620 | io->flags |= UBLK_IO_FLAG_ABORTED; | |
621 | blk_mq_end_request(req, BLK_STS_IOERR); | |
622 | } | |
623 | } | |
624 | ||
c86019ff Z |
625 | static void ubq_complete_io_cmd(struct ublk_io *io, int res) |
626 | { | |
627 | /* mark this cmd owned by ublksrv */ | |
628 | io->flags |= UBLK_IO_FLAG_OWNED_BY_SRV; | |
629 | ||
630 | /* | |
631 | * clear ACTIVE since we are done with this sqe/cmd slot | |
632 | * We can only accept io cmd in case of being not active. | |
633 | */ | |
634 | io->flags &= ~UBLK_IO_FLAG_ACTIVE; | |
635 | ||
636 | /* tell ublksrv one io request is coming */ | |
637 | io_uring_cmd_done(io->cmd, res, 0); | |
638 | } | |
639 | ||
71f28f31 ML |
640 | #define UBLK_REQUEUE_DELAY_MS 3 |
641 | ||
0edb3696 | 642 | static inline void __ublk_rq_task_work(struct request *req) |
71f28f31 | 643 | { |
71f28f31 | 644 | struct ublk_queue *ubq = req->mq_hctx->driver_data; |
0edb3696 | 645 | struct ublk_device *ub = ubq->dev; |
71f28f31 ML |
646 | int tag = req->tag; |
647 | struct ublk_io *io = &ubq->ios[tag]; | |
966120b5 | 648 | bool task_exiting = current != ubq->ubq_daemon || ubq_daemon_is_dying(ubq); |
71f28f31 ML |
649 | unsigned int mapped_bytes; |
650 | ||
651 | pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n", | |
652 | __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, | |
653 | ublk_get_iod(ubq, req->tag)->addr); | |
654 | ||
655 | if (unlikely(task_exiting)) { | |
656 | blk_mq_end_request(req, BLK_STS_IOERR); | |
657 | mod_delayed_work(system_wq, &ub->monitor_work, 0); | |
658 | return; | |
659 | } | |
660 | ||
c86019ff Z |
661 | if (ublk_need_get_data(ubq) && |
662 | (req_op(req) == REQ_OP_WRITE || | |
663 | req_op(req) == REQ_OP_FLUSH)) { | |
664 | /* | |
665 | * We have not handled UBLK_IO_NEED_GET_DATA command yet, | |
666 | * so immepdately pass UBLK_IO_RES_NEED_GET_DATA to ublksrv | |
667 | * and notify it. | |
668 | */ | |
669 | if (!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA)) { | |
670 | io->flags |= UBLK_IO_FLAG_NEED_GET_DATA; | |
671 | pr_devel("%s: need get data. op %d, qid %d tag %d io_flags %x\n", | |
672 | __func__, io->cmd->cmd_op, ubq->q_id, | |
673 | req->tag, io->flags); | |
674 | ubq_complete_io_cmd(io, UBLK_IO_RES_NEED_GET_DATA); | |
675 | return; | |
676 | } | |
677 | /* | |
678 | * We have handled UBLK_IO_NEED_GET_DATA command, | |
679 | * so clear UBLK_IO_FLAG_NEED_GET_DATA now and just | |
680 | * do the copy work. | |
681 | */ | |
682 | io->flags &= ~UBLK_IO_FLAG_NEED_GET_DATA; | |
92cb6e2e Z |
683 | /* update iod->addr because ublksrv may have passed a new io buffer */ |
684 | ublk_get_iod(ubq, req->tag)->addr = io->addr; | |
685 | pr_devel("%s: update iod->addr: op %d, qid %d tag %d io_flags %x addr %llx\n", | |
686 | __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, | |
687 | ublk_get_iod(ubq, req->tag)->addr); | |
c86019ff Z |
688 | } |
689 | ||
71f28f31 ML |
690 | mapped_bytes = ublk_map_io(ubq, req, io); |
691 | ||
692 | /* partially mapped, update io descriptor */ | |
693 | if (unlikely(mapped_bytes != blk_rq_bytes(req))) { | |
694 | /* | |
695 | * Nothing mapped, retry until we succeed. | |
696 | * | |
697 | * We may never succeed in mapping any bytes here because | |
698 | * of OOM. TODO: reserve one buffer with single page pinned | |
699 | * for providing forward progress guarantee. | |
700 | */ | |
701 | if (unlikely(!mapped_bytes)) { | |
702 | blk_mq_requeue_request(req, false); | |
703 | blk_mq_delay_kick_requeue_list(req->q, | |
704 | UBLK_REQUEUE_DELAY_MS); | |
705 | return; | |
706 | } | |
707 | ||
708 | ublk_get_iod(ubq, req->tag)->nr_sectors = | |
709 | mapped_bytes >> 9; | |
710 | } | |
711 | ||
c86019ff | 712 | ubq_complete_io_cmd(io, UBLK_IO_RES_OK); |
71f28f31 ML |
713 | } |
714 | ||
0edb3696 ML |
715 | static void ublk_rq_task_work_cb(struct io_uring_cmd *cmd) |
716 | { | |
717 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); | |
718 | ||
719 | __ublk_rq_task_work(pdu->req); | |
720 | } | |
721 | ||
722 | static void ublk_rq_task_work_fn(struct callback_head *work) | |
723 | { | |
724 | struct ublk_rq_data *data = container_of(work, | |
725 | struct ublk_rq_data, work); | |
726 | struct request *req = blk_mq_rq_from_pdu(data); | |
727 | ||
728 | __ublk_rq_task_work(req); | |
729 | } | |
730 | ||
71f28f31 ML |
731 | static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, |
732 | const struct blk_mq_queue_data *bd) | |
733 | { | |
734 | struct ublk_queue *ubq = hctx->driver_data; | |
735 | struct request *rq = bd->rq; | |
71f28f31 ML |
736 | blk_status_t res; |
737 | ||
738 | /* fill iod to slot in io cmd buffer */ | |
739 | res = ublk_setup_iod(ubq, rq); | |
740 | if (unlikely(res != BLK_STS_OK)) | |
741 | return BLK_STS_IOERR; | |
742 | ||
743 | blk_mq_start_request(bd->rq); | |
744 | ||
745 | if (unlikely(ubq_daemon_is_dying(ubq))) { | |
0edb3696 | 746 | fail: |
71f28f31 ML |
747 | mod_delayed_work(system_wq, &ubq->dev->monitor_work, 0); |
748 | return BLK_STS_IOERR; | |
749 | } | |
750 | ||
0edb3696 ML |
751 | if (ublk_can_use_task_work(ubq)) { |
752 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq); | |
753 | enum task_work_notify_mode notify_mode = bd->last ? | |
754 | TWA_SIGNAL_NO_IPI : TWA_NONE; | |
755 | ||
756 | if (task_work_add(ubq->ubq_daemon, &data->work, notify_mode)) | |
757 | goto fail; | |
758 | } else { | |
e6190dd0 Z |
759 | struct ublk_io *io = &ubq->ios[rq->tag]; |
760 | struct io_uring_cmd *cmd = io->cmd; | |
0edb3696 ML |
761 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); |
762 | ||
e6190dd0 Z |
763 | /* |
764 | * If the check pass, we know that this is a re-issued request aborted | |
765 | * previously in monitor_work because the ubq_daemon(cmd's task) is | |
766 | * PF_EXITING. We cannot call io_uring_cmd_complete_in_task() anymore | |
767 | * because this ioucmd's io_uring context may be freed now if no inflight | |
768 | * ioucmd exists. Otherwise we may cause null-deref in ctx->fallback_work. | |
769 | * | |
770 | * Note: monitor_work sets UBLK_IO_FLAG_ABORTED and ends this request(releasing | |
771 | * the tag). Then the request is re-started(allocating the tag) and we are here. | |
772 | * Since releasing/allocating a tag implies smp_mb(), finding UBLK_IO_FLAG_ABORTED | |
773 | * guarantees that here is a re-issued request aborted previously. | |
774 | */ | |
775 | if ((io->flags & UBLK_IO_FLAG_ABORTED)) | |
776 | goto fail; | |
777 | ||
0edb3696 ML |
778 | pdu->req = rq; |
779 | io_uring_cmd_complete_in_task(cmd, ublk_rq_task_work_cb); | |
780 | } | |
71f28f31 ML |
781 | |
782 | return BLK_STS_OK; | |
783 | } | |
784 | ||
0edb3696 ML |
785 | static void ublk_commit_rqs(struct blk_mq_hw_ctx *hctx) |
786 | { | |
787 | struct ublk_queue *ubq = hctx->driver_data; | |
788 | ||
789 | if (ublk_can_use_task_work(ubq)) | |
790 | __set_notify_signal(ubq->ubq_daemon); | |
791 | } | |
71f28f31 ML |
792 | |
793 | static int ublk_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data, | |
794 | unsigned int hctx_idx) | |
795 | { | |
cebbe577 | 796 | struct ublk_device *ub = driver_data; |
71f28f31 ML |
797 | struct ublk_queue *ubq = ublk_get_queue(ub, hctx->queue_num); |
798 | ||
799 | hctx->driver_data = ubq; | |
800 | return 0; | |
801 | } | |
802 | ||
0edb3696 ML |
803 | static int ublk_init_rq(struct blk_mq_tag_set *set, struct request *req, |
804 | unsigned int hctx_idx, unsigned int numa_node) | |
805 | { | |
806 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); | |
807 | ||
808 | init_task_work(&data->work, ublk_rq_task_work_fn); | |
809 | return 0; | |
810 | } | |
811 | ||
71f28f31 ML |
812 | static const struct blk_mq_ops ublk_mq_ops = { |
813 | .queue_rq = ublk_queue_rq, | |
0edb3696 | 814 | .commit_rqs = ublk_commit_rqs, |
71f28f31 | 815 | .init_hctx = ublk_init_hctx, |
0edb3696 | 816 | .init_request = ublk_init_rq, |
71f28f31 ML |
817 | }; |
818 | ||
819 | static int ublk_ch_open(struct inode *inode, struct file *filp) | |
820 | { | |
821 | struct ublk_device *ub = container_of(inode->i_cdev, | |
822 | struct ublk_device, cdev); | |
823 | ||
fa362045 CH |
824 | if (test_and_set_bit(UB_STATE_OPEN, &ub->state)) |
825 | return -EBUSY; | |
826 | filp->private_data = ub; | |
827 | return 0; | |
71f28f31 ML |
828 | } |
829 | ||
830 | static int ublk_ch_release(struct inode *inode, struct file *filp) | |
831 | { | |
832 | struct ublk_device *ub = filp->private_data; | |
833 | ||
fa362045 | 834 | clear_bit(UB_STATE_OPEN, &ub->state); |
71f28f31 ML |
835 | return 0; |
836 | } | |
837 | ||
838 | /* map pre-allocated per-queue cmd buffer to ublksrv daemon */ | |
839 | static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma) | |
840 | { | |
841 | struct ublk_device *ub = filp->private_data; | |
842 | size_t sz = vma->vm_end - vma->vm_start; | |
843 | unsigned max_sz = UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc); | |
844 | unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT; | |
845 | int q_id, ret = 0; | |
846 | ||
e94eb459 | 847 | spin_lock(&ub->mm_lock); |
71f28f31 ML |
848 | if (!ub->mm) |
849 | ub->mm = current->mm; | |
850 | if (current->mm != ub->mm) | |
851 | ret = -EINVAL; | |
e94eb459 | 852 | spin_unlock(&ub->mm_lock); |
71f28f31 ML |
853 | |
854 | if (ret) | |
855 | return ret; | |
856 | ||
857 | if (vma->vm_flags & VM_WRITE) | |
858 | return -EPERM; | |
859 | ||
860 | end = UBLKSRV_CMD_BUF_OFFSET + ub->dev_info.nr_hw_queues * max_sz; | |
861 | if (phys_off < UBLKSRV_CMD_BUF_OFFSET || phys_off >= end) | |
862 | return -EINVAL; | |
863 | ||
864 | q_id = (phys_off - UBLKSRV_CMD_BUF_OFFSET) / max_sz; | |
865 | pr_devel("%s: qid %d, pid %d, addr %lx pg_off %lx sz %lu\n", | |
866 | __func__, q_id, current->pid, vma->vm_start, | |
867 | phys_off, (unsigned long)sz); | |
868 | ||
869 | if (sz != ublk_queue_cmd_buf_size(ub, q_id)) | |
870 | return -EINVAL; | |
871 | ||
872 | pfn = virt_to_phys(ublk_queue_cmd_buf(ub, q_id)) >> PAGE_SHIFT; | |
873 | return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot); | |
874 | } | |
875 | ||
876 | static void ublk_commit_completion(struct ublk_device *ub, | |
877 | struct ublksrv_io_cmd *ub_cmd) | |
878 | { | |
879 | u32 qid = ub_cmd->q_id, tag = ub_cmd->tag; | |
880 | struct ublk_queue *ubq = ublk_get_queue(ub, qid); | |
881 | struct ublk_io *io = &ubq->ios[tag]; | |
882 | struct request *req; | |
883 | ||
884 | /* now this cmd slot is owned by nbd driver */ | |
885 | io->flags &= ~UBLK_IO_FLAG_OWNED_BY_SRV; | |
886 | io->res = ub_cmd->result; | |
887 | ||
888 | /* find the io request and complete */ | |
889 | req = blk_mq_tag_to_rq(ub->tag_set.tags[qid], tag); | |
890 | ||
891 | if (req && likely(!blk_should_fake_timeout(req->q))) | |
892 | ublk_complete_rq(req); | |
893 | } | |
894 | ||
895 | /* | |
896 | * When ->ubq_daemon is exiting, either new request is ended immediately, | |
897 | * or any queued io command is drained, so it is safe to abort queue | |
898 | * lockless | |
899 | */ | |
900 | static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) | |
901 | { | |
902 | int i; | |
903 | ||
904 | if (!ublk_get_device(ub)) | |
905 | return; | |
906 | ||
907 | for (i = 0; i < ubq->q_depth; i++) { | |
908 | struct ublk_io *io = &ubq->ios[i]; | |
909 | ||
910 | if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) { | |
911 | struct request *rq; | |
912 | ||
913 | /* | |
914 | * Either we fail the request or ublk_rq_task_work_fn | |
915 | * will do it | |
916 | */ | |
917 | rq = blk_mq_tag_to_rq(ub->tag_set.tags[ubq->q_id], i); | |
918 | if (rq) | |
919 | __ublk_fail_req(io, rq); | |
920 | } | |
921 | } | |
922 | ublk_put_device(ub); | |
923 | } | |
924 | ||
925 | static void ublk_daemon_monitor_work(struct work_struct *work) | |
926 | { | |
927 | struct ublk_device *ub = | |
928 | container_of(work, struct ublk_device, monitor_work.work); | |
929 | int i; | |
930 | ||
931 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) { | |
932 | struct ublk_queue *ubq = ublk_get_queue(ub, i); | |
933 | ||
934 | if (ubq_daemon_is_dying(ubq)) { | |
935 | schedule_work(&ub->stop_work); | |
936 | ||
937 | /* abort queue is for making forward progress */ | |
938 | ublk_abort_queue(ub, ubq); | |
939 | } | |
940 | } | |
941 | ||
942 | /* | |
943 | * We can't schedule monitor work after ublk_remove() is started. | |
944 | * | |
945 | * No need ub->mutex, monitor work are canceled after state is marked | |
946 | * as DEAD, so DEAD state is observed reliably. | |
947 | */ | |
948 | if (ub->dev_info.state != UBLK_S_DEV_DEAD) | |
949 | schedule_delayed_work(&ub->monitor_work, | |
950 | UBLK_DAEMON_MONITOR_PERIOD); | |
951 | } | |
952 | ||
a8ce5f52 ML |
953 | static inline bool ublk_queue_ready(struct ublk_queue *ubq) |
954 | { | |
955 | return ubq->nr_io_ready == ubq->q_depth; | |
956 | } | |
957 | ||
71f28f31 ML |
958 | static void ublk_cancel_queue(struct ublk_queue *ubq) |
959 | { | |
960 | int i; | |
961 | ||
a8ce5f52 ML |
962 | if (!ublk_queue_ready(ubq)) |
963 | return; | |
964 | ||
71f28f31 ML |
965 | for (i = 0; i < ubq->q_depth; i++) { |
966 | struct ublk_io *io = &ubq->ios[i]; | |
967 | ||
968 | if (io->flags & UBLK_IO_FLAG_ACTIVE) | |
969 | io_uring_cmd_done(io->cmd, UBLK_IO_RES_ABORT, 0); | |
970 | } | |
a8ce5f52 ML |
971 | |
972 | /* all io commands are canceled */ | |
973 | ubq->nr_io_ready = 0; | |
71f28f31 ML |
974 | } |
975 | ||
976 | /* Cancel all pending commands, must be called after del_gendisk() returns */ | |
977 | static void ublk_cancel_dev(struct ublk_device *ub) | |
978 | { | |
979 | int i; | |
980 | ||
981 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) | |
982 | ublk_cancel_queue(ublk_get_queue(ub, i)); | |
983 | } | |
984 | ||
985 | static void ublk_stop_dev(struct ublk_device *ub) | |
986 | { | |
987 | mutex_lock(&ub->mutex); | |
6d9e6dfd | 988 | if (ub->dev_info.state != UBLK_S_DEV_LIVE) |
71f28f31 ML |
989 | goto unlock; |
990 | ||
991 | del_gendisk(ub->ub_disk); | |
992 | ub->dev_info.state = UBLK_S_DEV_DEAD; | |
993 | ub->dev_info.ublksrv_pid = -1; | |
6d9e6dfd CH |
994 | put_disk(ub->ub_disk); |
995 | ub->ub_disk = NULL; | |
71f28f31 | 996 | unlock: |
a8ce5f52 | 997 | ublk_cancel_dev(ub); |
71f28f31 ML |
998 | mutex_unlock(&ub->mutex); |
999 | cancel_delayed_work_sync(&ub->monitor_work); | |
1000 | } | |
1001 | ||
71f28f31 ML |
1002 | /* device can only be started after all IOs are ready */ |
1003 | static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq) | |
1004 | { | |
1005 | mutex_lock(&ub->mutex); | |
1006 | ubq->nr_io_ready++; | |
1007 | if (ublk_queue_ready(ubq)) { | |
1008 | ubq->ubq_daemon = current; | |
1009 | get_task_struct(ubq->ubq_daemon); | |
1010 | ub->nr_queues_ready++; | |
1011 | } | |
1012 | if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues) | |
1013 | complete_all(&ub->completion); | |
1014 | mutex_unlock(&ub->mutex); | |
1015 | } | |
1016 | ||
c86019ff Z |
1017 | static void ublk_handle_need_get_data(struct ublk_device *ub, int q_id, |
1018 | int tag, struct io_uring_cmd *cmd) | |
1019 | { | |
1020 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
1021 | struct request *req = blk_mq_tag_to_rq(ub->tag_set.tags[q_id], tag); | |
1022 | ||
1023 | if (ublk_can_use_task_work(ubq)) { | |
1024 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(req); | |
1025 | ||
1026 | /* should not fail since we call it just in ubq->ubq_daemon */ | |
1027 | task_work_add(ubq->ubq_daemon, &data->work, TWA_SIGNAL_NO_IPI); | |
1028 | } else { | |
1029 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(cmd); | |
1030 | ||
1031 | pdu->req = req; | |
1032 | io_uring_cmd_complete_in_task(cmd, ublk_rq_task_work_cb); | |
1033 | } | |
1034 | } | |
1035 | ||
71f28f31 ML |
1036 | static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) |
1037 | { | |
1038 | struct ublksrv_io_cmd *ub_cmd = (struct ublksrv_io_cmd *)cmd->cmd; | |
1039 | struct ublk_device *ub = cmd->file->private_data; | |
1040 | struct ublk_queue *ubq; | |
1041 | struct ublk_io *io; | |
1042 | u32 cmd_op = cmd->cmd_op; | |
1043 | unsigned tag = ub_cmd->tag; | |
1044 | int ret = -EINVAL; | |
1045 | ||
1046 | pr_devel("%s: received: cmd op %d queue %d tag %d result %d\n", | |
1047 | __func__, cmd->cmd_op, ub_cmd->q_id, tag, | |
1048 | ub_cmd->result); | |
1049 | ||
1050 | if (!(issue_flags & IO_URING_F_SQE128)) | |
1051 | goto out; | |
1052 | ||
1053 | if (ub_cmd->q_id >= ub->dev_info.nr_hw_queues) | |
1054 | goto out; | |
1055 | ||
1056 | ubq = ublk_get_queue(ub, ub_cmd->q_id); | |
1057 | if (!ubq || ub_cmd->q_id != ubq->q_id) | |
1058 | goto out; | |
1059 | ||
1060 | if (ubq->ubq_daemon && ubq->ubq_daemon != current) | |
1061 | goto out; | |
1062 | ||
1063 | if (tag >= ubq->q_depth) | |
1064 | goto out; | |
1065 | ||
1066 | io = &ubq->ios[tag]; | |
1067 | ||
1068 | /* there is pending io cmd, something must be wrong */ | |
1069 | if (io->flags & UBLK_IO_FLAG_ACTIVE) { | |
1070 | ret = -EBUSY; | |
1071 | goto out; | |
1072 | } | |
1073 | ||
c86019ff Z |
1074 | /* |
1075 | * ensure that the user issues UBLK_IO_NEED_GET_DATA | |
1076 | * iff the driver have set the UBLK_IO_FLAG_NEED_GET_DATA. | |
1077 | */ | |
1078 | if ((!!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA)) | |
1079 | ^ (cmd_op == UBLK_IO_NEED_GET_DATA)) | |
1080 | goto out; | |
1081 | ||
71f28f31 ML |
1082 | switch (cmd_op) { |
1083 | case UBLK_IO_FETCH_REQ: | |
1084 | /* UBLK_IO_FETCH_REQ is only allowed before queue is setup */ | |
1085 | if (ublk_queue_ready(ubq)) { | |
1086 | ret = -EBUSY; | |
1087 | goto out; | |
1088 | } | |
1089 | /* | |
1090 | * The io is being handled by server, so COMMIT_RQ is expected | |
1091 | * instead of FETCH_REQ | |
1092 | */ | |
1093 | if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV) | |
1094 | goto out; | |
1095 | /* FETCH_RQ has to provide IO buffer */ | |
1096 | if (!ub_cmd->addr) | |
1097 | goto out; | |
1098 | io->cmd = cmd; | |
1099 | io->flags |= UBLK_IO_FLAG_ACTIVE; | |
1100 | io->addr = ub_cmd->addr; | |
1101 | ||
1102 | ublk_mark_io_ready(ub, ubq); | |
1103 | break; | |
1104 | case UBLK_IO_COMMIT_AND_FETCH_REQ: | |
1105 | /* FETCH_RQ has to provide IO buffer */ | |
1106 | if (!ub_cmd->addr) | |
1107 | goto out; | |
1108 | if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) | |
1109 | goto out; | |
1110 | io->addr = ub_cmd->addr; | |
1111 | io->flags |= UBLK_IO_FLAG_ACTIVE; | |
1112 | io->cmd = cmd; | |
1113 | ublk_commit_completion(ub, ub_cmd); | |
1114 | break; | |
c86019ff Z |
1115 | case UBLK_IO_NEED_GET_DATA: |
1116 | if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) | |
1117 | goto out; | |
1118 | io->addr = ub_cmd->addr; | |
1119 | io->cmd = cmd; | |
1120 | io->flags |= UBLK_IO_FLAG_ACTIVE; | |
1121 | ublk_handle_need_get_data(ub, ub_cmd->q_id, ub_cmd->tag, cmd); | |
1122 | break; | |
71f28f31 ML |
1123 | default: |
1124 | goto out; | |
1125 | } | |
1126 | return -EIOCBQUEUED; | |
1127 | ||
1128 | out: | |
71f28f31 ML |
1129 | io_uring_cmd_done(cmd, ret, 0); |
1130 | pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n", | |
1131 | __func__, cmd_op, tag, ret, io->flags); | |
1132 | return -EIOCBQUEUED; | |
1133 | } | |
1134 | ||
1135 | static const struct file_operations ublk_ch_fops = { | |
1136 | .owner = THIS_MODULE, | |
1137 | .open = ublk_ch_open, | |
1138 | .release = ublk_ch_release, | |
1139 | .llseek = no_llseek, | |
1140 | .uring_cmd = ublk_ch_uring_cmd, | |
1141 | .mmap = ublk_ch_mmap, | |
1142 | }; | |
1143 | ||
1144 | static void ublk_deinit_queue(struct ublk_device *ub, int q_id) | |
1145 | { | |
1146 | int size = ublk_queue_cmd_buf_size(ub, q_id); | |
1147 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
1148 | ||
1149 | if (ubq->ubq_daemon) | |
1150 | put_task_struct(ubq->ubq_daemon); | |
1151 | if (ubq->io_cmd_buf) | |
1152 | free_pages((unsigned long)ubq->io_cmd_buf, get_order(size)); | |
1153 | } | |
1154 | ||
1155 | static int ublk_init_queue(struct ublk_device *ub, int q_id) | |
1156 | { | |
1157 | struct ublk_queue *ubq = ublk_get_queue(ub, q_id); | |
1158 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO; | |
1159 | void *ptr; | |
1160 | int size; | |
1161 | ||
6d8c5afc | 1162 | ubq->flags = ub->dev_info.flags; |
71f28f31 ML |
1163 | ubq->q_id = q_id; |
1164 | ubq->q_depth = ub->dev_info.queue_depth; | |
1165 | size = ublk_queue_cmd_buf_size(ub, q_id); | |
1166 | ||
1167 | ptr = (void *) __get_free_pages(gfp_flags, get_order(size)); | |
1168 | if (!ptr) | |
1169 | return -ENOMEM; | |
1170 | ||
1171 | ubq->io_cmd_buf = ptr; | |
1172 | ubq->dev = ub; | |
1173 | return 0; | |
1174 | } | |
1175 | ||
1176 | static void ublk_deinit_queues(struct ublk_device *ub) | |
1177 | { | |
1178 | int nr_queues = ub->dev_info.nr_hw_queues; | |
1179 | int i; | |
1180 | ||
1181 | if (!ub->__queues) | |
1182 | return; | |
1183 | ||
1184 | for (i = 0; i < nr_queues; i++) | |
1185 | ublk_deinit_queue(ub, i); | |
1186 | kfree(ub->__queues); | |
1187 | } | |
1188 | ||
1189 | static int ublk_init_queues(struct ublk_device *ub) | |
1190 | { | |
1191 | int nr_queues = ub->dev_info.nr_hw_queues; | |
1192 | int depth = ub->dev_info.queue_depth; | |
1193 | int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io); | |
1194 | int i, ret = -ENOMEM; | |
1195 | ||
1196 | ub->queue_size = ubq_size; | |
1197 | ub->__queues = kcalloc(nr_queues, ubq_size, GFP_KERNEL); | |
1198 | if (!ub->__queues) | |
1199 | return ret; | |
1200 | ||
1201 | for (i = 0; i < nr_queues; i++) { | |
1202 | if (ublk_init_queue(ub, i)) | |
1203 | goto fail; | |
1204 | } | |
1205 | ||
1206 | init_completion(&ub->completion); | |
1207 | return 0; | |
1208 | ||
1209 | fail: | |
1210 | ublk_deinit_queues(ub); | |
1211 | return ret; | |
1212 | } | |
1213 | ||
fa9482e0 | 1214 | static int ublk_alloc_dev_number(struct ublk_device *ub, int idx) |
71f28f31 ML |
1215 | { |
1216 | int i = idx; | |
1217 | int err; | |
1218 | ||
1219 | spin_lock(&ublk_idr_lock); | |
1220 | /* allocate id, if @id >= 0, we're requesting that specific id */ | |
1221 | if (i >= 0) { | |
1222 | err = idr_alloc(&ublk_index_idr, ub, i, i + 1, GFP_NOWAIT); | |
1223 | if (err == -ENOSPC) | |
1224 | err = -EEXIST; | |
1225 | } else { | |
1226 | err = idr_alloc(&ublk_index_idr, ub, 0, 0, GFP_NOWAIT); | |
1227 | } | |
1228 | spin_unlock(&ublk_idr_lock); | |
1229 | ||
1230 | if (err >= 0) | |
1231 | ub->ub_number = err; | |
1232 | ||
1233 | return err; | |
1234 | } | |
1235 | ||
fa9482e0 | 1236 | static void ublk_free_dev_number(struct ublk_device *ub) |
71f28f31 ML |
1237 | { |
1238 | spin_lock(&ublk_idr_lock); | |
1239 | idr_remove(&ublk_index_idr, ub->ub_number); | |
1240 | wake_up_all(&ublk_idr_wq); | |
1241 | spin_unlock(&ublk_idr_lock); | |
71f28f31 ML |
1242 | } |
1243 | ||
1244 | static void ublk_cdev_rel(struct device *dev) | |
1245 | { | |
1246 | struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev); | |
1247 | ||
71f28f31 | 1248 | blk_mq_free_tag_set(&ub->tag_set); |
71f28f31 | 1249 | ublk_deinit_queues(ub); |
fa9482e0 CH |
1250 | ublk_free_dev_number(ub); |
1251 | mutex_destroy(&ub->mutex); | |
1252 | kfree(ub); | |
71f28f31 ML |
1253 | } |
1254 | ||
1255 | static int ublk_add_chdev(struct ublk_device *ub) | |
1256 | { | |
1257 | struct device *dev = &ub->cdev_dev; | |
1258 | int minor = ub->ub_number; | |
1259 | int ret; | |
1260 | ||
1261 | dev->parent = ublk_misc.this_device; | |
1262 | dev->devt = MKDEV(MAJOR(ublk_chr_devt), minor); | |
1263 | dev->class = ublk_chr_class; | |
1264 | dev->release = ublk_cdev_rel; | |
1265 | device_initialize(dev); | |
1266 | ||
1267 | ret = dev_set_name(dev, "ublkc%d", minor); | |
1268 | if (ret) | |
1269 | goto fail; | |
1270 | ||
1271 | cdev_init(&ub->cdev, &ublk_ch_fops); | |
1272 | ret = cdev_device_add(&ub->cdev, dev); | |
1273 | if (ret) | |
1274 | goto fail; | |
1275 | return 0; | |
1276 | fail: | |
1277 | put_device(dev); | |
1278 | return ret; | |
1279 | } | |
1280 | ||
1281 | static void ublk_stop_work_fn(struct work_struct *work) | |
1282 | { | |
1283 | struct ublk_device *ub = | |
1284 | container_of(work, struct ublk_device, stop_work); | |
1285 | ||
1286 | ublk_stop_dev(ub); | |
1287 | } | |
1288 | ||
4bf9cbf3 | 1289 | /* align max io buffer size with PAGE_SIZE */ |
6d9e6dfd | 1290 | static void ublk_align_max_io_size(struct ublk_device *ub) |
71f28f31 | 1291 | { |
4bf9cbf3 | 1292 | unsigned int max_io_bytes = ub->dev_info.max_io_buf_bytes; |
71f28f31 | 1293 | |
4bf9cbf3 ML |
1294 | ub->dev_info.max_io_buf_bytes = |
1295 | round_down(max_io_bytes, PAGE_SIZE); | |
71f28f31 ML |
1296 | } |
1297 | ||
fa9482e0 | 1298 | static int ublk_add_tag_set(struct ublk_device *ub) |
71f28f31 | 1299 | { |
71f28f31 ML |
1300 | ub->tag_set.ops = &ublk_mq_ops; |
1301 | ub->tag_set.nr_hw_queues = ub->dev_info.nr_hw_queues; | |
1302 | ub->tag_set.queue_depth = ub->dev_info.queue_depth; | |
1303 | ub->tag_set.numa_node = NUMA_NO_NODE; | |
0edb3696 | 1304 | ub->tag_set.cmd_size = sizeof(struct ublk_rq_data); |
71f28f31 ML |
1305 | ub->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; |
1306 | ub->tag_set.driver_data = ub; | |
fa9482e0 | 1307 | return blk_mq_alloc_tag_set(&ub->tag_set); |
71f28f31 ML |
1308 | } |
1309 | ||
1310 | static void ublk_remove(struct ublk_device *ub) | |
1311 | { | |
34d8f2be CH |
1312 | ublk_stop_dev(ub); |
1313 | cancel_work_sync(&ub->stop_work); | |
71f28f31 ML |
1314 | cdev_device_del(&ub->cdev, &ub->cdev_dev); |
1315 | put_device(&ub->cdev_dev); | |
1316 | } | |
1317 | ||
1318 | static struct ublk_device *ublk_get_device_from_id(int idx) | |
1319 | { | |
1320 | struct ublk_device *ub = NULL; | |
1321 | ||
1322 | if (idx < 0) | |
1323 | return NULL; | |
1324 | ||
1325 | spin_lock(&ublk_idr_lock); | |
1326 | ub = idr_find(&ublk_index_idr, idx); | |
1327 | if (ub) | |
1328 | ub = ublk_get_device(ub); | |
1329 | spin_unlock(&ublk_idr_lock); | |
1330 | ||
1331 | return ub; | |
1332 | } | |
1333 | ||
34d8f2be | 1334 | static int ublk_ctrl_start_dev(struct io_uring_cmd *cmd) |
71f28f31 ML |
1335 | { |
1336 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
71f28f31 | 1337 | int ublksrv_pid = (int)header->data[0]; |
34d8f2be | 1338 | struct ublk_device *ub; |
6d9e6dfd | 1339 | struct gendisk *disk; |
34d8f2be | 1340 | int ret = -EINVAL; |
71f28f31 ML |
1341 | |
1342 | if (ublksrv_pid <= 0) | |
34d8f2be CH |
1343 | return -EINVAL; |
1344 | ||
1345 | ub = ublk_get_device_from_id(header->dev_id); | |
1346 | if (!ub) | |
1347 | return -EINVAL; | |
71f28f31 ML |
1348 | |
1349 | wait_for_completion_interruptible(&ub->completion); | |
1350 | ||
1351 | schedule_delayed_work(&ub->monitor_work, UBLK_DAEMON_MONITOR_PERIOD); | |
1352 | ||
1353 | mutex_lock(&ub->mutex); | |
6d9e6dfd CH |
1354 | if (ub->dev_info.state == UBLK_S_DEV_LIVE || |
1355 | test_bit(UB_STATE_USED, &ub->state)) { | |
71f28f31 | 1356 | ret = -EEXIST; |
34d8f2be | 1357 | goto out_unlock; |
71f28f31 | 1358 | } |
71f28f31 | 1359 | |
6d9e6dfd CH |
1360 | disk = blk_mq_alloc_disk(&ub->tag_set, ub); |
1361 | if (IS_ERR(disk)) { | |
1362 | ret = PTR_ERR(disk); | |
1363 | goto out_unlock; | |
34d8f2be | 1364 | } |
6d9e6dfd CH |
1365 | sprintf(disk->disk_name, "ublkb%d", ub->ub_number); |
1366 | disk->fops = &ub_fops; | |
1367 | disk->private_data = ub; | |
1368 | ||
34d8f2be | 1369 | ub->dev_info.ublksrv_pid = ublksrv_pid; |
6d9e6dfd | 1370 | ub->ub_disk = disk; |
0aa73170 ML |
1371 | |
1372 | ret = ublk_apply_params(ub); | |
1373 | if (ret) | |
1374 | goto out_put_disk; | |
1375 | ||
6d9e6dfd CH |
1376 | get_device(&ub->cdev_dev); |
1377 | ret = add_disk(disk); | |
1378 | if (ret) { | |
93d71ec8 ML |
1379 | /* |
1380 | * Has to drop the reference since ->free_disk won't be | |
1381 | * called in case of add_disk failure. | |
1382 | */ | |
1383 | ublk_put_device(ub); | |
0aa73170 | 1384 | goto out_put_disk; |
6d9e6dfd CH |
1385 | } |
1386 | set_bit(UB_STATE_USED, &ub->state); | |
34d8f2be | 1387 | ub->dev_info.state = UBLK_S_DEV_LIVE; |
0aa73170 ML |
1388 | out_put_disk: |
1389 | if (ret) | |
1390 | put_disk(disk); | |
34d8f2be CH |
1391 | out_unlock: |
1392 | mutex_unlock(&ub->mutex); | |
1393 | ublk_put_device(ub); | |
71f28f31 ML |
1394 | return ret; |
1395 | } | |
1396 | ||
71f28f31 ML |
1397 | static int ublk_ctrl_get_queue_affinity(struct io_uring_cmd *cmd) |
1398 | { | |
1399 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1400 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
71f28f31 | 1401 | struct ublk_device *ub; |
c50061f0 | 1402 | cpumask_var_t cpumask; |
71f28f31 ML |
1403 | unsigned long queue; |
1404 | unsigned int retlen; | |
c50061f0 | 1405 | unsigned int i; |
f2450f8a | 1406 | int ret = -EINVAL; |
34d8f2be CH |
1407 | |
1408 | if (header->len * BITS_PER_BYTE < nr_cpu_ids) | |
1409 | return -EINVAL; | |
1410 | if (header->len & (sizeof(unsigned long)-1)) | |
1411 | return -EINVAL; | |
1412 | if (!header->addr) | |
1413 | return -EINVAL; | |
71f28f31 ML |
1414 | |
1415 | ub = ublk_get_device_from_id(header->dev_id); | |
1416 | if (!ub) | |
c50061f0 | 1417 | return -EINVAL; |
71f28f31 | 1418 | |
71f28f31 ML |
1419 | queue = header->data[0]; |
1420 | if (queue >= ub->dev_info.nr_hw_queues) | |
c50061f0 | 1421 | goto out_put_device; |
71f28f31 | 1422 | |
c50061f0 CH |
1423 | ret = -ENOMEM; |
1424 | if (!zalloc_cpumask_var(&cpumask, GFP_KERNEL)) | |
1425 | goto out_put_device; | |
1426 | ||
1427 | for_each_possible_cpu(i) { | |
1428 | if (ub->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[i] == queue) | |
1429 | cpumask_set_cpu(i, cpumask); | |
71f28f31 | 1430 | } |
c50061f0 CH |
1431 | |
1432 | ret = -EFAULT; | |
1433 | retlen = min_t(unsigned short, header->len, cpumask_size()); | |
1434 | if (copy_to_user(argp, cpumask, retlen)) | |
1435 | goto out_free_cpumask; | |
1436 | if (retlen != header->len && | |
1437 | clear_user(argp + retlen, header->len - retlen)) | |
1438 | goto out_free_cpumask; | |
1439 | ||
71f28f31 | 1440 | ret = 0; |
c50061f0 CH |
1441 | out_free_cpumask: |
1442 | free_cpumask_var(cpumask); | |
1443 | out_put_device: | |
1444 | ublk_put_device(ub); | |
71f28f31 ML |
1445 | return ret; |
1446 | } | |
1447 | ||
34d8f2be | 1448 | static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info) |
71f28f31 | 1449 | { |
34d8f2be | 1450 | pr_devel("%s: dev id %d flags %llx\n", __func__, |
6d8c5afc | 1451 | info->dev_id, info->flags); |
4bf9cbf3 ML |
1452 | pr_devel("\t nr_hw_queues %d queue_depth %d\n", |
1453 | info->nr_hw_queues, info->queue_depth); | |
34d8f2be CH |
1454 | } |
1455 | ||
1456 | static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) | |
1457 | { | |
1458 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1459 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
1460 | struct ublksrv_ctrl_dev_info info; | |
71f28f31 | 1461 | struct ublk_device *ub; |
34d8f2be CH |
1462 | int ret = -EINVAL; |
1463 | ||
1464 | if (header->len < sizeof(info) || !header->addr) | |
1465 | return -EINVAL; | |
1466 | if (header->queue_id != (u16)-1) { | |
1467 | pr_warn("%s: queue_id is wrong %x\n", | |
1468 | __func__, header->queue_id); | |
1469 | return -EINVAL; | |
1470 | } | |
1471 | if (copy_from_user(&info, argp, sizeof(info))) | |
1472 | return -EFAULT; | |
1473 | ublk_dump_dev_info(&info); | |
1474 | if (header->dev_id != info.dev_id) { | |
1475 | pr_warn("%s: dev id not match %u %u\n", | |
1476 | __func__, header->dev_id, info.dev_id); | |
1477 | return -EINVAL; | |
1478 | } | |
71f28f31 ML |
1479 | |
1480 | ret = mutex_lock_killable(&ublk_ctl_mutex); | |
1481 | if (ret) | |
1482 | return ret; | |
1483 | ||
cfee7e4d CH |
1484 | ret = -ENOMEM; |
1485 | ub = kzalloc(sizeof(*ub), GFP_KERNEL); | |
1486 | if (!ub) | |
1487 | goto out_unlock; | |
fa9482e0 CH |
1488 | mutex_init(&ub->mutex); |
1489 | spin_lock_init(&ub->mm_lock); | |
1490 | INIT_WORK(&ub->stop_work, ublk_stop_work_fn); | |
1491 | INIT_DELAYED_WORK(&ub->monitor_work, ublk_daemon_monitor_work); | |
cfee7e4d | 1492 | |
fa9482e0 CH |
1493 | ret = ublk_alloc_dev_number(ub, header->dev_id); |
1494 | if (ret < 0) | |
1495 | goto out_free_ub; | |
71f28f31 | 1496 | |
34d8f2be | 1497 | memcpy(&ub->dev_info, &info, sizeof(info)); |
71f28f31 | 1498 | |
34d8f2be CH |
1499 | /* update device id */ |
1500 | ub->dev_info.dev_id = ub->ub_number; | |
1501 | ||
6d8c5afc ML |
1502 | /* |
1503 | * 64bit flags will be copied back to userspace as feature | |
1504 | * negotiation result, so have to clear flags which driver | |
1505 | * doesn't support yet, then userspace can get correct flags | |
1506 | * (features) to handle. | |
1507 | */ | |
1508 | ub->dev_info.flags &= UBLK_F_ALL; | |
1509 | ||
fa9482e0 | 1510 | /* We are not ready to support zero copy */ |
6d8c5afc | 1511 | ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY; |
fa9482e0 | 1512 | |
fa9482e0 CH |
1513 | ub->dev_info.nr_hw_queues = min_t(unsigned int, |
1514 | ub->dev_info.nr_hw_queues, nr_cpu_ids); | |
1515 | ublk_align_max_io_size(ub); | |
1516 | ||
1517 | ret = ublk_init_queues(ub); | |
34d8f2be | 1518 | if (ret) |
fa9482e0 | 1519 | goto out_free_dev_number; |
34d8f2be | 1520 | |
fa9482e0 CH |
1521 | ret = ublk_add_tag_set(ub); |
1522 | if (ret) | |
1523 | goto out_deinit_queues; | |
1524 | ||
1525 | ret = -EFAULT; | |
1526 | if (copy_to_user(argp, &ub->dev_info, sizeof(info))) | |
1527 | goto out_free_tag_set; | |
1528 | ||
1529 | /* | |
1530 | * Add the char dev so that ublksrv daemon can be setup. | |
1531 | * ublk_add_chdev() will cleanup everything if it fails. | |
1532 | */ | |
1533 | ret = ublk_add_chdev(ub); | |
1534 | goto out_unlock; | |
1535 | ||
1536 | out_free_tag_set: | |
1537 | blk_mq_free_tag_set(&ub->tag_set); | |
1538 | out_deinit_queues: | |
1539 | ublk_deinit_queues(ub); | |
1540 | out_free_dev_number: | |
1541 | ublk_free_dev_number(ub); | |
1542 | out_free_ub: | |
1543 | mutex_destroy(&ub->mutex); | |
1544 | kfree(ub); | |
34d8f2be | 1545 | out_unlock: |
71f28f31 | 1546 | mutex_unlock(&ublk_ctl_mutex); |
71f28f31 ML |
1547 | return ret; |
1548 | } | |
1549 | ||
1550 | static inline bool ublk_idr_freed(int id) | |
1551 | { | |
1552 | void *ptr; | |
1553 | ||
1554 | spin_lock(&ublk_idr_lock); | |
1555 | ptr = idr_find(&ublk_index_idr, id); | |
1556 | spin_unlock(&ublk_idr_lock); | |
1557 | ||
1558 | return ptr == NULL; | |
1559 | } | |
1560 | ||
1561 | static int ublk_ctrl_del_dev(int idx) | |
1562 | { | |
1563 | struct ublk_device *ub; | |
1564 | int ret; | |
1565 | ||
1566 | ret = mutex_lock_killable(&ublk_ctl_mutex); | |
1567 | if (ret) | |
1568 | return ret; | |
1569 | ||
1570 | ub = ublk_get_device_from_id(idx); | |
1571 | if (ub) { | |
1572 | ublk_remove(ub); | |
1573 | ublk_put_device(ub); | |
1574 | ret = 0; | |
1575 | } else { | |
1576 | ret = -ENODEV; | |
1577 | } | |
1578 | ||
1579 | /* | |
1580 | * Wait until the idr is removed, then it can be reused after | |
1581 | * DEL_DEV command is returned. | |
1582 | */ | |
1583 | if (!ret) | |
1584 | wait_event(ublk_idr_wq, ublk_idr_freed(idx)); | |
1585 | mutex_unlock(&ublk_ctl_mutex); | |
1586 | ||
1587 | return ret; | |
1588 | } | |
1589 | ||
71f28f31 ML |
1590 | static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd) |
1591 | { | |
1592 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1593 | ||
1594 | pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n", | |
1595 | __func__, cmd->cmd_op, header->dev_id, header->queue_id, | |
1596 | header->data[0], header->addr, header->len); | |
1597 | } | |
1598 | ||
34d8f2be | 1599 | static int ublk_ctrl_stop_dev(struct io_uring_cmd *cmd) |
71f28f31 ML |
1600 | { |
1601 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
34d8f2be | 1602 | struct ublk_device *ub; |
71f28f31 | 1603 | |
34d8f2be CH |
1604 | ub = ublk_get_device_from_id(header->dev_id); |
1605 | if (!ub) | |
1606 | return -EINVAL; | |
71f28f31 | 1607 | |
34d8f2be CH |
1608 | ublk_stop_dev(ub); |
1609 | cancel_work_sync(&ub->stop_work); | |
71f28f31 | 1610 | |
34d8f2be | 1611 | ublk_put_device(ub); |
71f28f31 ML |
1612 | return 0; |
1613 | } | |
1614 | ||
34d8f2be | 1615 | static int ublk_ctrl_get_dev_info(struct io_uring_cmd *cmd) |
71f28f31 ML |
1616 | { |
1617 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1618 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
71f28f31 | 1619 | struct ublk_device *ub; |
34d8f2be CH |
1620 | int ret = 0; |
1621 | ||
1622 | if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr) | |
1623 | return -EINVAL; | |
1624 | ||
1625 | ub = ublk_get_device_from_id(header->dev_id); | |
1626 | if (!ub) | |
1627 | return -EINVAL; | |
1628 | ||
1629 | if (copy_to_user(argp, &ub->dev_info, sizeof(ub->dev_info))) | |
1630 | ret = -EFAULT; | |
1631 | ublk_put_device(ub); | |
1632 | ||
1633 | return ret; | |
1634 | } | |
1635 | ||
0aa73170 ML |
1636 | static int ublk_ctrl_get_params(struct io_uring_cmd *cmd) |
1637 | { | |
1638 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1639 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
1640 | struct ublk_params_header ph; | |
1641 | struct ublk_device *ub; | |
1642 | int ret; | |
1643 | ||
1644 | if (header->len <= sizeof(ph) || !header->addr) | |
1645 | return -EINVAL; | |
1646 | ||
1647 | if (copy_from_user(&ph, argp, sizeof(ph))) | |
1648 | return -EFAULT; | |
1649 | ||
1650 | if (ph.len > header->len || !ph.len) | |
1651 | return -EINVAL; | |
1652 | ||
1653 | if (ph.len > sizeof(struct ublk_params)) | |
1654 | ph.len = sizeof(struct ublk_params); | |
1655 | ||
1656 | ub = ublk_get_device_from_id(header->dev_id); | |
1657 | if (!ub) | |
1658 | return -EINVAL; | |
1659 | ||
1660 | mutex_lock(&ub->mutex); | |
1661 | if (copy_to_user(argp, &ub->params, ph.len)) | |
1662 | ret = -EFAULT; | |
1663 | else | |
1664 | ret = 0; | |
1665 | mutex_unlock(&ub->mutex); | |
1666 | ||
1667 | ublk_put_device(ub); | |
1668 | return ret; | |
1669 | } | |
1670 | ||
1671 | static int ublk_ctrl_set_params(struct io_uring_cmd *cmd) | |
1672 | { | |
1673 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
1674 | void __user *argp = (void __user *)(unsigned long)header->addr; | |
1675 | struct ublk_params_header ph; | |
1676 | struct ublk_device *ub; | |
1677 | int ret = -EFAULT; | |
1678 | ||
1679 | if (header->len <= sizeof(ph) || !header->addr) | |
1680 | return -EINVAL; | |
1681 | ||
1682 | if (copy_from_user(&ph, argp, sizeof(ph))) | |
1683 | return -EFAULT; | |
1684 | ||
1685 | if (ph.len > header->len || !ph.len || !ph.types) | |
1686 | return -EINVAL; | |
1687 | ||
1688 | if (ph.len > sizeof(struct ublk_params)) | |
1689 | ph.len = sizeof(struct ublk_params); | |
1690 | ||
1691 | ub = ublk_get_device_from_id(header->dev_id); | |
1692 | if (!ub) | |
1693 | return -EINVAL; | |
1694 | ||
1695 | /* parameters can only be changed when device isn't live */ | |
1696 | mutex_lock(&ub->mutex); | |
1697 | if (ub->dev_info.state == UBLK_S_DEV_LIVE) { | |
1698 | ret = -EACCES; | |
1699 | } else if (copy_from_user(&ub->params, argp, ph.len)) { | |
1700 | ret = -EFAULT; | |
1701 | } else { | |
1702 | /* clear all we don't support yet */ | |
1703 | ub->params.types &= UBLK_PARAM_TYPE_ALL; | |
1704 | ret = ublk_validate_params(ub); | |
1705 | } | |
1706 | mutex_unlock(&ub->mutex); | |
1707 | ublk_put_device(ub); | |
1708 | ||
1709 | return ret; | |
1710 | } | |
1711 | ||
34d8f2be CH |
1712 | static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, |
1713 | unsigned int issue_flags) | |
1714 | { | |
1715 | struct ublksrv_ctrl_cmd *header = (struct ublksrv_ctrl_cmd *)cmd->cmd; | |
71f28f31 ML |
1716 | int ret = -EINVAL; |
1717 | ||
1718 | ublk_ctrl_cmd_dump(cmd); | |
1719 | ||
1720 | if (!(issue_flags & IO_URING_F_SQE128)) | |
1721 | goto out; | |
1722 | ||
34d8f2be CH |
1723 | ret = -EPERM; |
1724 | if (!capable(CAP_SYS_ADMIN)) | |
71f28f31 ML |
1725 | goto out; |
1726 | ||
1727 | ret = -ENODEV; | |
34d8f2be | 1728 | switch (cmd->cmd_op) { |
71f28f31 | 1729 | case UBLK_CMD_START_DEV: |
34d8f2be | 1730 | ret = ublk_ctrl_start_dev(cmd); |
71f28f31 ML |
1731 | break; |
1732 | case UBLK_CMD_STOP_DEV: | |
34d8f2be | 1733 | ret = ublk_ctrl_stop_dev(cmd); |
71f28f31 ML |
1734 | break; |
1735 | case UBLK_CMD_GET_DEV_INFO: | |
34d8f2be | 1736 | ret = ublk_ctrl_get_dev_info(cmd); |
71f28f31 ML |
1737 | break; |
1738 | case UBLK_CMD_ADD_DEV: | |
34d8f2be | 1739 | ret = ublk_ctrl_add_dev(cmd); |
71f28f31 ML |
1740 | break; |
1741 | case UBLK_CMD_DEL_DEV: | |
1742 | ret = ublk_ctrl_del_dev(header->dev_id); | |
1743 | break; | |
1744 | case UBLK_CMD_GET_QUEUE_AFFINITY: | |
1745 | ret = ublk_ctrl_get_queue_affinity(cmd); | |
1746 | break; | |
0aa73170 ML |
1747 | case UBLK_CMD_GET_PARAMS: |
1748 | ret = ublk_ctrl_get_params(cmd); | |
1749 | break; | |
1750 | case UBLK_CMD_SET_PARAMS: | |
1751 | ret = ublk_ctrl_set_params(cmd); | |
1752 | break; | |
71f28f31 ML |
1753 | default: |
1754 | break; | |
6b1439d2 | 1755 | } |
71f28f31 ML |
1756 | out: |
1757 | io_uring_cmd_done(cmd, ret, 0); | |
1758 | pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n", | |
1759 | __func__, ret, cmd->cmd_op, header->dev_id, header->queue_id); | |
1760 | return -EIOCBQUEUED; | |
1761 | } | |
1762 | ||
1763 | static const struct file_operations ublk_ctl_fops = { | |
1764 | .open = nonseekable_open, | |
1765 | .uring_cmd = ublk_ctrl_uring_cmd, | |
1766 | .owner = THIS_MODULE, | |
1767 | .llseek = noop_llseek, | |
1768 | }; | |
1769 | ||
1770 | static struct miscdevice ublk_misc = { | |
1771 | .minor = MISC_DYNAMIC_MINOR, | |
1772 | .name = "ublk-control", | |
1773 | .fops = &ublk_ctl_fops, | |
1774 | }; | |
1775 | ||
1776 | static int __init ublk_init(void) | |
1777 | { | |
1778 | int ret; | |
1779 | ||
1780 | init_waitqueue_head(&ublk_idr_wq); | |
1781 | ||
1782 | ret = misc_register(&ublk_misc); | |
1783 | if (ret) | |
1784 | return ret; | |
1785 | ||
1786 | ret = alloc_chrdev_region(&ublk_chr_devt, 0, UBLK_MINORS, "ublk-char"); | |
1787 | if (ret) | |
1788 | goto unregister_mis; | |
1789 | ||
1790 | ublk_chr_class = class_create(THIS_MODULE, "ublk-char"); | |
1791 | if (IS_ERR(ublk_chr_class)) { | |
1792 | ret = PTR_ERR(ublk_chr_class); | |
1793 | goto free_chrdev_region; | |
1794 | } | |
1795 | return 0; | |
1796 | ||
1797 | free_chrdev_region: | |
1798 | unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); | |
1799 | unregister_mis: | |
1800 | misc_deregister(&ublk_misc); | |
1801 | return ret; | |
1802 | } | |
1803 | ||
1804 | static void __exit ublk_exit(void) | |
1805 | { | |
1806 | struct ublk_device *ub; | |
1807 | int id; | |
1808 | ||
1809 | class_destroy(ublk_chr_class); | |
1810 | ||
1811 | misc_deregister(&ublk_misc); | |
1812 | ||
1813 | idr_for_each_entry(&ublk_index_idr, ub, id) | |
1814 | ublk_remove(ub); | |
1815 | ||
1816 | idr_destroy(&ublk_index_idr); | |
1817 | unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); | |
1818 | } | |
1819 | ||
1820 | module_init(ublk_init); | |
1821 | module_exit(ublk_exit); | |
1822 | ||
1823 | MODULE_AUTHOR("Ming Lei <ming.lei@redhat.com>"); | |
1824 | MODULE_LICENSE("GPL"); |