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> |
44 | #include <linux/task_work.h> |
45 | #include <linux/namei.h> |
46 | #include <linux/kref.h> |
47 | #include <uapi/linux/ublk_cmd.h> |
48 | |
49 | #define UBLK_MINORS (1U << MINORBITS) |
50 | |
51 | /* All UBLK_F_* have to be included into UBLK_F_ALL */ |
52 | #define UBLK_F_ALL (UBLK_F_SUPPORT_ZERO_COPY \ |
53 | | UBLK_F_URING_CMD_COMP_IN_TASK \ |
54 | | UBLK_F_NEED_GET_DATA \ |
55 | | UBLK_F_USER_RECOVERY \ |
56 | | UBLK_F_USER_RECOVERY_REISSUE \ |
57 | | UBLK_F_UNPRIVILEGED_DEV \ |
58 | | UBLK_F_CMD_IOCTL_ENCODE \ |
59 | | UBLK_F_USER_COPY \ |
60 | | UBLK_F_ZONED) |
61 | |
62 | /* All UBLK_PARAM_TYPE_* should be included here */ |
63 | #define UBLK_PARAM_TYPE_ALL \ |
64 | (UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD | \ |
65 | UBLK_PARAM_TYPE_DEVT | UBLK_PARAM_TYPE_ZONED) |
66 | |
67 | struct ublk_rq_data { |
68 | struct llist_node node; |
69 | |
70 | struct kref ref; |
71 | __u64 sector; |
72 | __u32 operation; |
73 | __u32 nr_zones; |
74 | }; |
75 | |
76 | struct ublk_uring_cmd_pdu { |
77 | struct ublk_queue *ubq; |
78 | u16 tag; |
79 | }; |
80 | |
81 | /* |
82 | * io command is active: sqe cmd is received, and its cqe isn't done |
83 | * |
84 | * If the flag is set, the io command is owned by ublk driver, and waited |
85 | * for incoming blk-mq request from the ublk block device. |
86 | * |
87 | * If the flag is cleared, the io command will be completed, and owned by |
88 | * ublk server. |
89 | */ |
90 | #define UBLK_IO_FLAG_ACTIVE 0x01 |
91 | |
92 | /* |
93 | * IO command is completed via cqe, and it is being handled by ublksrv, and |
94 | * not committed yet |
95 | * |
96 | * Basically exclusively with UBLK_IO_FLAG_ACTIVE, so can be served for |
97 | * cross verification |
98 | */ |
99 | #define UBLK_IO_FLAG_OWNED_BY_SRV 0x02 |
100 | |
101 | /* |
102 | * IO command is aborted, so this flag is set in case of |
103 | * !UBLK_IO_FLAG_ACTIVE. |
104 | * |
105 | * After this flag is observed, any pending or new incoming request |
106 | * associated with this io command will be failed immediately |
107 | */ |
108 | #define UBLK_IO_FLAG_ABORTED 0x04 |
109 | |
110 | /* |
111 | * UBLK_IO_FLAG_NEED_GET_DATA is set because IO command requires |
112 | * get data buffer address from ublksrv. |
113 | * |
114 | * Then, bio data could be copied into this data buffer for a WRITE request |
115 | * after the IO command is issued again and UBLK_IO_FLAG_NEED_GET_DATA is unset. |
116 | */ |
117 | #define UBLK_IO_FLAG_NEED_GET_DATA 0x08 |
118 | |
119 | /* atomic RW with ubq->cancel_lock */ |
120 | #define UBLK_IO_FLAG_CANCELED 0x80000000 |
121 | |
122 | struct ublk_io { |
123 | /* userspace buffer address from io cmd */ |
124 | __u64 addr; |
125 | unsigned int flags; |
126 | int res; |
127 | |
128 | struct io_uring_cmd *cmd; |
129 | }; |
130 | |
131 | struct ublk_queue { |
132 | int q_id; |
133 | int q_depth; |
134 | |
135 | unsigned long flags; |
136 | struct task_struct *ubq_daemon; |
137 | char *io_cmd_buf; |
138 | |
139 | struct llist_head io_cmds; |
140 | |
141 | unsigned long io_addr; /* mapped vm address */ |
142 | unsigned int max_io_sz; |
143 | bool force_abort; |
144 | bool timeout; |
145 | bool canceling; |
146 | unsigned short nr_io_ready; /* how many ios setup */ |
147 | spinlock_t cancel_lock; |
148 | struct ublk_device *dev; |
149 | struct ublk_io ios[]; |
150 | }; |
151 | |
152 | struct ublk_device { |
153 | struct gendisk *ub_disk; |
154 | |
155 | char *__queues; |
156 | |
157 | unsigned int queue_size; |
158 | struct ublksrv_ctrl_dev_info dev_info; |
159 | |
160 | struct blk_mq_tag_set tag_set; |
161 | |
162 | struct cdev cdev; |
163 | struct device cdev_dev; |
164 | |
165 | #define UB_STATE_OPEN 0 |
166 | #define UB_STATE_USED 1 |
167 | #define UB_STATE_DELETED 2 |
168 | unsigned long state; |
169 | int ub_number; |
170 | |
171 | struct mutex mutex; |
172 | |
173 | spinlock_t lock; |
174 | struct mm_struct *mm; |
175 | |
176 | struct ublk_params params; |
177 | |
178 | struct completion completion; |
179 | unsigned int nr_queues_ready; |
180 | unsigned int nr_privileged_daemon; |
181 | |
182 | struct work_struct quiesce_work; |
183 | struct work_struct stop_work; |
184 | }; |
185 | |
186 | /* header of ublk_params */ |
187 | struct { |
188 | __u32 ; |
189 | __u32 ; |
190 | }; |
191 | |
192 | static bool ublk_abort_requests(struct ublk_device *ub, struct ublk_queue *ubq); |
193 | |
194 | static inline unsigned int ublk_req_build_flags(struct request *req); |
195 | static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq, |
196 | int tag); |
197 | static inline bool ublk_dev_is_user_copy(const struct ublk_device *ub) |
198 | { |
199 | return ub->dev_info.flags & UBLK_F_USER_COPY; |
200 | } |
201 | |
202 | static inline bool ublk_dev_is_zoned(const struct ublk_device *ub) |
203 | { |
204 | return ub->dev_info.flags & UBLK_F_ZONED; |
205 | } |
206 | |
207 | static inline bool ublk_queue_is_zoned(struct ublk_queue *ubq) |
208 | { |
209 | return ubq->flags & UBLK_F_ZONED; |
210 | } |
211 | |
212 | #ifdef CONFIG_BLK_DEV_ZONED |
213 | |
214 | static int ublk_get_nr_zones(const struct ublk_device *ub) |
215 | { |
216 | const struct ublk_param_basic *p = &ub->params.basic; |
217 | |
218 | /* Zone size is a power of 2 */ |
219 | return p->dev_sectors >> ilog2(p->chunk_sectors); |
220 | } |
221 | |
222 | static int ublk_revalidate_disk_zones(struct ublk_device *ub) |
223 | { |
224 | return blk_revalidate_disk_zones(disk: ub->ub_disk, NULL); |
225 | } |
226 | |
227 | static int ublk_dev_param_zoned_validate(const struct ublk_device *ub) |
228 | { |
229 | const struct ublk_param_zoned *p = &ub->params.zoned; |
230 | int nr_zones; |
231 | |
232 | if (!ublk_dev_is_zoned(ub)) |
233 | return -EINVAL; |
234 | |
235 | if (!p->max_zone_append_sectors) |
236 | return -EINVAL; |
237 | |
238 | nr_zones = ublk_get_nr_zones(ub); |
239 | |
240 | if (p->max_active_zones > nr_zones) |
241 | return -EINVAL; |
242 | |
243 | if (p->max_open_zones > nr_zones) |
244 | return -EINVAL; |
245 | |
246 | return 0; |
247 | } |
248 | |
249 | static int ublk_dev_param_zoned_apply(struct ublk_device *ub) |
250 | { |
251 | const struct ublk_param_zoned *p = &ub->params.zoned; |
252 | |
253 | disk_set_zoned(disk: ub->ub_disk, model: BLK_ZONED_HM); |
254 | blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q: ub->ub_disk->queue); |
255 | blk_queue_required_elevator_features(q: ub->ub_disk->queue, |
256 | ELEVATOR_F_ZBD_SEQ_WRITE); |
257 | disk_set_max_active_zones(disk: ub->ub_disk, max_active_zones: p->max_active_zones); |
258 | disk_set_max_open_zones(disk: ub->ub_disk, max_open_zones: p->max_open_zones); |
259 | blk_queue_max_zone_append_sectors(q: ub->ub_disk->queue, max_zone_append_sectors: p->max_zone_append_sectors); |
260 | |
261 | ub->ub_disk->nr_zones = ublk_get_nr_zones(ub); |
262 | |
263 | return 0; |
264 | } |
265 | |
266 | /* Based on virtblk_alloc_report_buffer */ |
267 | static void *ublk_alloc_report_buffer(struct ublk_device *ublk, |
268 | unsigned int nr_zones, size_t *buflen) |
269 | { |
270 | struct request_queue *q = ublk->ub_disk->queue; |
271 | size_t bufsize; |
272 | void *buf; |
273 | |
274 | nr_zones = min_t(unsigned int, nr_zones, |
275 | ublk->ub_disk->nr_zones); |
276 | |
277 | bufsize = nr_zones * sizeof(struct blk_zone); |
278 | bufsize = |
279 | min_t(size_t, bufsize, queue_max_hw_sectors(q) << SECTOR_SHIFT); |
280 | |
281 | while (bufsize >= sizeof(struct blk_zone)) { |
282 | buf = kvmalloc(size: bufsize, GFP_KERNEL | __GFP_NORETRY); |
283 | if (buf) { |
284 | *buflen = bufsize; |
285 | return buf; |
286 | } |
287 | bufsize >>= 1; |
288 | } |
289 | |
290 | *buflen = 0; |
291 | return NULL; |
292 | } |
293 | |
294 | static int ublk_report_zones(struct gendisk *disk, sector_t sector, |
295 | unsigned int nr_zones, report_zones_cb cb, void *data) |
296 | { |
297 | struct ublk_device *ub = disk->private_data; |
298 | unsigned int zone_size_sectors = disk->queue->limits.chunk_sectors; |
299 | unsigned int first_zone = sector >> ilog2(zone_size_sectors); |
300 | unsigned int done_zones = 0; |
301 | unsigned int max_zones_per_request; |
302 | int ret; |
303 | struct blk_zone *buffer; |
304 | size_t buffer_length; |
305 | |
306 | nr_zones = min_t(unsigned int, ub->ub_disk->nr_zones - first_zone, |
307 | nr_zones); |
308 | |
309 | buffer = ublk_alloc_report_buffer(ublk: ub, nr_zones, buflen: &buffer_length); |
310 | if (!buffer) |
311 | return -ENOMEM; |
312 | |
313 | max_zones_per_request = buffer_length / sizeof(struct blk_zone); |
314 | |
315 | while (done_zones < nr_zones) { |
316 | unsigned int remaining_zones = nr_zones - done_zones; |
317 | unsigned int zones_in_request = |
318 | min_t(unsigned int, remaining_zones, max_zones_per_request); |
319 | struct request *req; |
320 | struct ublk_rq_data *pdu; |
321 | blk_status_t status; |
322 | |
323 | memset(buffer, 0, buffer_length); |
324 | |
325 | req = blk_mq_alloc_request(q: disk->queue, opf: REQ_OP_DRV_IN, flags: 0); |
326 | if (IS_ERR(ptr: req)) { |
327 | ret = PTR_ERR(ptr: req); |
328 | goto out; |
329 | } |
330 | |
331 | pdu = blk_mq_rq_to_pdu(rq: req); |
332 | pdu->operation = UBLK_IO_OP_REPORT_ZONES; |
333 | pdu->sector = sector; |
334 | pdu->nr_zones = zones_in_request; |
335 | |
336 | ret = blk_rq_map_kern(disk->queue, req, buffer, buffer_length, |
337 | GFP_KERNEL); |
338 | if (ret) { |
339 | blk_mq_free_request(rq: req); |
340 | goto out; |
341 | } |
342 | |
343 | status = blk_execute_rq(rq: req, at_head: 0); |
344 | ret = blk_status_to_errno(status); |
345 | blk_mq_free_request(rq: req); |
346 | if (ret) |
347 | goto out; |
348 | |
349 | for (unsigned int i = 0; i < zones_in_request; i++) { |
350 | struct blk_zone *zone = buffer + i; |
351 | |
352 | /* A zero length zone means no more zones in this response */ |
353 | if (!zone->len) |
354 | break; |
355 | |
356 | ret = cb(zone, i, data); |
357 | if (ret) |
358 | goto out; |
359 | |
360 | done_zones++; |
361 | sector += zone_size_sectors; |
362 | |
363 | } |
364 | } |
365 | |
366 | ret = done_zones; |
367 | |
368 | out: |
369 | kvfree(addr: buffer); |
370 | return ret; |
371 | } |
372 | |
373 | static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq, |
374 | struct request *req) |
375 | { |
376 | struct ublksrv_io_desc *iod = ublk_get_iod(ubq, tag: req->tag); |
377 | struct ublk_io *io = &ubq->ios[req->tag]; |
378 | struct ublk_rq_data *pdu = blk_mq_rq_to_pdu(rq: req); |
379 | u32 ublk_op; |
380 | |
381 | switch (req_op(req)) { |
382 | case REQ_OP_ZONE_OPEN: |
383 | ublk_op = UBLK_IO_OP_ZONE_OPEN; |
384 | break; |
385 | case REQ_OP_ZONE_CLOSE: |
386 | ublk_op = UBLK_IO_OP_ZONE_CLOSE; |
387 | break; |
388 | case REQ_OP_ZONE_FINISH: |
389 | ublk_op = UBLK_IO_OP_ZONE_FINISH; |
390 | break; |
391 | case REQ_OP_ZONE_RESET: |
392 | ublk_op = UBLK_IO_OP_ZONE_RESET; |
393 | break; |
394 | case REQ_OP_ZONE_APPEND: |
395 | ublk_op = UBLK_IO_OP_ZONE_APPEND; |
396 | break; |
397 | case REQ_OP_ZONE_RESET_ALL: |
398 | ublk_op = UBLK_IO_OP_ZONE_RESET_ALL; |
399 | break; |
400 | case REQ_OP_DRV_IN: |
401 | ublk_op = pdu->operation; |
402 | switch (ublk_op) { |
403 | case UBLK_IO_OP_REPORT_ZONES: |
404 | iod->op_flags = ublk_op | ublk_req_build_flags(req); |
405 | iod->nr_zones = pdu->nr_zones; |
406 | iod->start_sector = pdu->sector; |
407 | return BLK_STS_OK; |
408 | default: |
409 | return BLK_STS_IOERR; |
410 | } |
411 | case REQ_OP_DRV_OUT: |
412 | /* We do not support drv_out */ |
413 | return BLK_STS_NOTSUPP; |
414 | default: |
415 | return BLK_STS_IOERR; |
416 | } |
417 | |
418 | iod->op_flags = ublk_op | ublk_req_build_flags(req); |
419 | iod->nr_sectors = blk_rq_sectors(rq: req); |
420 | iod->start_sector = blk_rq_pos(rq: req); |
421 | iod->addr = io->addr; |
422 | |
423 | return BLK_STS_OK; |
424 | } |
425 | |
426 | #else |
427 | |
428 | #define ublk_report_zones (NULL) |
429 | |
430 | static int ublk_dev_param_zoned_validate(const struct ublk_device *ub) |
431 | { |
432 | return -EOPNOTSUPP; |
433 | } |
434 | |
435 | static int ublk_dev_param_zoned_apply(struct ublk_device *ub) |
436 | { |
437 | return -EOPNOTSUPP; |
438 | } |
439 | |
440 | static int ublk_revalidate_disk_zones(struct ublk_device *ub) |
441 | { |
442 | return 0; |
443 | } |
444 | |
445 | static blk_status_t ublk_setup_iod_zoned(struct ublk_queue *ubq, |
446 | struct request *req) |
447 | { |
448 | return BLK_STS_NOTSUPP; |
449 | } |
450 | |
451 | #endif |
452 | |
453 | static inline void __ublk_complete_rq(struct request *req); |
454 | static void ublk_complete_rq(struct kref *ref); |
455 | |
456 | static dev_t ublk_chr_devt; |
457 | static const struct class ublk_chr_class = { |
458 | .name = "ublk-char" , |
459 | }; |
460 | |
461 | static DEFINE_IDR(ublk_index_idr); |
462 | static DEFINE_SPINLOCK(ublk_idr_lock); |
463 | static wait_queue_head_t ublk_idr_wq; /* wait until one idr is freed */ |
464 | |
465 | static DEFINE_MUTEX(ublk_ctl_mutex); |
466 | |
467 | /* |
468 | * Max ublk devices allowed to add |
469 | * |
470 | * It can be extended to one per-user limit in future or even controlled |
471 | * by cgroup. |
472 | */ |
473 | #define UBLK_MAX_UBLKS UBLK_MINORS |
474 | static unsigned int ublks_max = 64; |
475 | static unsigned int ublks_added; /* protected by ublk_ctl_mutex */ |
476 | |
477 | static struct miscdevice ublk_misc; |
478 | |
479 | static inline unsigned ublk_pos_to_hwq(loff_t pos) |
480 | { |
481 | return ((pos - UBLKSRV_IO_BUF_OFFSET) >> UBLK_QID_OFF) & |
482 | UBLK_QID_BITS_MASK; |
483 | } |
484 | |
485 | static inline unsigned ublk_pos_to_buf_off(loff_t pos) |
486 | { |
487 | return (pos - UBLKSRV_IO_BUF_OFFSET) & UBLK_IO_BUF_BITS_MASK; |
488 | } |
489 | |
490 | static inline unsigned ublk_pos_to_tag(loff_t pos) |
491 | { |
492 | return ((pos - UBLKSRV_IO_BUF_OFFSET) >> UBLK_TAG_OFF) & |
493 | UBLK_TAG_BITS_MASK; |
494 | } |
495 | |
496 | static void ublk_dev_param_basic_apply(struct ublk_device *ub) |
497 | { |
498 | struct request_queue *q = ub->ub_disk->queue; |
499 | const struct ublk_param_basic *p = &ub->params.basic; |
500 | |
501 | blk_queue_logical_block_size(q, 1 << p->logical_bs_shift); |
502 | blk_queue_physical_block_size(q, 1 << p->physical_bs_shift); |
503 | blk_queue_io_min(q, min: 1 << p->io_min_shift); |
504 | blk_queue_io_opt(q, opt: 1 << p->io_opt_shift); |
505 | |
506 | blk_queue_write_cache(q, enabled: p->attrs & UBLK_ATTR_VOLATILE_CACHE, |
507 | fua: p->attrs & UBLK_ATTR_FUA); |
508 | if (p->attrs & UBLK_ATTR_ROTATIONAL) |
509 | blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); |
510 | else |
511 | blk_queue_flag_set(QUEUE_FLAG_NONROT, q); |
512 | |
513 | blk_queue_max_hw_sectors(q, p->max_sectors); |
514 | blk_queue_chunk_sectors(q, p->chunk_sectors); |
515 | blk_queue_virt_boundary(q, p->virt_boundary_mask); |
516 | |
517 | if (p->attrs & UBLK_ATTR_READ_ONLY) |
518 | set_disk_ro(disk: ub->ub_disk, read_only: true); |
519 | |
520 | set_capacity(disk: ub->ub_disk, size: p->dev_sectors); |
521 | } |
522 | |
523 | static void ublk_dev_param_discard_apply(struct ublk_device *ub) |
524 | { |
525 | struct request_queue *q = ub->ub_disk->queue; |
526 | const struct ublk_param_discard *p = &ub->params.discard; |
527 | |
528 | q->limits.discard_alignment = p->discard_alignment; |
529 | q->limits.discard_granularity = p->discard_granularity; |
530 | blk_queue_max_discard_sectors(q, max_discard_sectors: p->max_discard_sectors); |
531 | blk_queue_max_write_zeroes_sectors(q, |
532 | max_write_same_sectors: p->max_write_zeroes_sectors); |
533 | blk_queue_max_discard_segments(q, p->max_discard_segments); |
534 | } |
535 | |
536 | static int ublk_validate_params(const struct ublk_device *ub) |
537 | { |
538 | /* basic param is the only one which must be set */ |
539 | if (ub->params.types & UBLK_PARAM_TYPE_BASIC) { |
540 | const struct ublk_param_basic *p = &ub->params.basic; |
541 | |
542 | if (p->logical_bs_shift > PAGE_SHIFT || p->logical_bs_shift < 9) |
543 | return -EINVAL; |
544 | |
545 | if (p->logical_bs_shift > p->physical_bs_shift) |
546 | return -EINVAL; |
547 | |
548 | if (p->max_sectors > (ub->dev_info.max_io_buf_bytes >> 9)) |
549 | return -EINVAL; |
550 | |
551 | if (ublk_dev_is_zoned(ub) && !p->chunk_sectors) |
552 | return -EINVAL; |
553 | } else |
554 | return -EINVAL; |
555 | |
556 | if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) { |
557 | const struct ublk_param_discard *p = &ub->params.discard; |
558 | |
559 | /* So far, only support single segment discard */ |
560 | if (p->max_discard_sectors && p->max_discard_segments != 1) |
561 | return -EINVAL; |
562 | |
563 | if (!p->discard_granularity) |
564 | return -EINVAL; |
565 | } |
566 | |
567 | /* dev_t is read-only */ |
568 | if (ub->params.types & UBLK_PARAM_TYPE_DEVT) |
569 | return -EINVAL; |
570 | |
571 | if (ub->params.types & UBLK_PARAM_TYPE_ZONED) |
572 | return ublk_dev_param_zoned_validate(ub); |
573 | else if (ublk_dev_is_zoned(ub)) |
574 | return -EINVAL; |
575 | |
576 | return 0; |
577 | } |
578 | |
579 | static int ublk_apply_params(struct ublk_device *ub) |
580 | { |
581 | if (!(ub->params.types & UBLK_PARAM_TYPE_BASIC)) |
582 | return -EINVAL; |
583 | |
584 | ublk_dev_param_basic_apply(ub); |
585 | |
586 | if (ub->params.types & UBLK_PARAM_TYPE_DISCARD) |
587 | ublk_dev_param_discard_apply(ub); |
588 | |
589 | if (ub->params.types & UBLK_PARAM_TYPE_ZONED) |
590 | return ublk_dev_param_zoned_apply(ub); |
591 | |
592 | return 0; |
593 | } |
594 | |
595 | static inline bool ublk_support_user_copy(const struct ublk_queue *ubq) |
596 | { |
597 | return ubq->flags & UBLK_F_USER_COPY; |
598 | } |
599 | |
600 | static inline bool ublk_need_req_ref(const struct ublk_queue *ubq) |
601 | { |
602 | /* |
603 | * read()/write() is involved in user copy, so request reference |
604 | * has to be grabbed |
605 | */ |
606 | return ublk_support_user_copy(ubq); |
607 | } |
608 | |
609 | static inline void ublk_init_req_ref(const struct ublk_queue *ubq, |
610 | struct request *req) |
611 | { |
612 | if (ublk_need_req_ref(ubq)) { |
613 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq: req); |
614 | |
615 | kref_init(kref: &data->ref); |
616 | } |
617 | } |
618 | |
619 | static inline bool ublk_get_req_ref(const struct ublk_queue *ubq, |
620 | struct request *req) |
621 | { |
622 | if (ublk_need_req_ref(ubq)) { |
623 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq: req); |
624 | |
625 | return kref_get_unless_zero(kref: &data->ref); |
626 | } |
627 | |
628 | return true; |
629 | } |
630 | |
631 | static inline void ublk_put_req_ref(const struct ublk_queue *ubq, |
632 | struct request *req) |
633 | { |
634 | if (ublk_need_req_ref(ubq)) { |
635 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq: req); |
636 | |
637 | kref_put(kref: &data->ref, release: ublk_complete_rq); |
638 | } else { |
639 | __ublk_complete_rq(req); |
640 | } |
641 | } |
642 | |
643 | static inline bool ublk_need_get_data(const struct ublk_queue *ubq) |
644 | { |
645 | return ubq->flags & UBLK_F_NEED_GET_DATA; |
646 | } |
647 | |
648 | static struct ublk_device *ublk_get_device(struct ublk_device *ub) |
649 | { |
650 | if (kobject_get_unless_zero(kobj: &ub->cdev_dev.kobj)) |
651 | return ub; |
652 | return NULL; |
653 | } |
654 | |
655 | static void ublk_put_device(struct ublk_device *ub) |
656 | { |
657 | put_device(dev: &ub->cdev_dev); |
658 | } |
659 | |
660 | static inline struct ublk_queue *ublk_get_queue(struct ublk_device *dev, |
661 | int qid) |
662 | { |
663 | return (struct ublk_queue *)&(dev->__queues[qid * dev->queue_size]); |
664 | } |
665 | |
666 | static inline bool ublk_rq_has_data(const struct request *rq) |
667 | { |
668 | return bio_has_data(bio: rq->bio); |
669 | } |
670 | |
671 | static inline struct ublksrv_io_desc *ublk_get_iod(struct ublk_queue *ubq, |
672 | int tag) |
673 | { |
674 | return (struct ublksrv_io_desc *) |
675 | &(ubq->io_cmd_buf[tag * sizeof(struct ublksrv_io_desc)]); |
676 | } |
677 | |
678 | static inline char *ublk_queue_cmd_buf(struct ublk_device *ub, int q_id) |
679 | { |
680 | return ublk_get_queue(dev: ub, qid: q_id)->io_cmd_buf; |
681 | } |
682 | |
683 | static inline int ublk_queue_cmd_buf_size(struct ublk_device *ub, int q_id) |
684 | { |
685 | struct ublk_queue *ubq = ublk_get_queue(dev: ub, qid: q_id); |
686 | |
687 | return round_up(ubq->q_depth * sizeof(struct ublksrv_io_desc), |
688 | PAGE_SIZE); |
689 | } |
690 | |
691 | static inline bool ublk_queue_can_use_recovery_reissue( |
692 | struct ublk_queue *ubq) |
693 | { |
694 | return (ubq->flags & UBLK_F_USER_RECOVERY) && |
695 | (ubq->flags & UBLK_F_USER_RECOVERY_REISSUE); |
696 | } |
697 | |
698 | static inline bool ublk_queue_can_use_recovery( |
699 | struct ublk_queue *ubq) |
700 | { |
701 | return ubq->flags & UBLK_F_USER_RECOVERY; |
702 | } |
703 | |
704 | static inline bool ublk_can_use_recovery(struct ublk_device *ub) |
705 | { |
706 | return ub->dev_info.flags & UBLK_F_USER_RECOVERY; |
707 | } |
708 | |
709 | static void ublk_free_disk(struct gendisk *disk) |
710 | { |
711 | struct ublk_device *ub = disk->private_data; |
712 | |
713 | clear_bit(UB_STATE_USED, addr: &ub->state); |
714 | put_device(dev: &ub->cdev_dev); |
715 | } |
716 | |
717 | static void ublk_store_owner_uid_gid(unsigned int *owner_uid, |
718 | unsigned int *owner_gid) |
719 | { |
720 | kuid_t uid; |
721 | kgid_t gid; |
722 | |
723 | current_uid_gid(&uid, &gid); |
724 | |
725 | *owner_uid = from_kuid(to: &init_user_ns, uid); |
726 | *owner_gid = from_kgid(to: &init_user_ns, gid); |
727 | } |
728 | |
729 | static int ublk_open(struct gendisk *disk, blk_mode_t mode) |
730 | { |
731 | struct ublk_device *ub = disk->private_data; |
732 | |
733 | if (capable(CAP_SYS_ADMIN)) |
734 | return 0; |
735 | |
736 | /* |
737 | * If it is one unprivileged device, only owner can open |
738 | * the disk. Otherwise it could be one trap made by one |
739 | * evil user who grants this disk's privileges to other |
740 | * users deliberately. |
741 | * |
742 | * This way is reasonable too given anyone can create |
743 | * unprivileged device, and no need other's grant. |
744 | */ |
745 | if (ub->dev_info.flags & UBLK_F_UNPRIVILEGED_DEV) { |
746 | unsigned int curr_uid, curr_gid; |
747 | |
748 | ublk_store_owner_uid_gid(owner_uid: &curr_uid, owner_gid: &curr_gid); |
749 | |
750 | if (curr_uid != ub->dev_info.owner_uid || curr_gid != |
751 | ub->dev_info.owner_gid) |
752 | return -EPERM; |
753 | } |
754 | |
755 | return 0; |
756 | } |
757 | |
758 | static const struct block_device_operations ub_fops = { |
759 | .owner = THIS_MODULE, |
760 | .open = ublk_open, |
761 | .free_disk = ublk_free_disk, |
762 | .report_zones = ublk_report_zones, |
763 | }; |
764 | |
765 | #define UBLK_MAX_PIN_PAGES 32 |
766 | |
767 | struct ublk_io_iter { |
768 | struct page *pages[UBLK_MAX_PIN_PAGES]; |
769 | struct bio *bio; |
770 | struct bvec_iter iter; |
771 | }; |
772 | |
773 | /* return how many pages are copied */ |
774 | static void ublk_copy_io_pages(struct ublk_io_iter *data, |
775 | size_t total, size_t pg_off, int dir) |
776 | { |
777 | unsigned done = 0; |
778 | unsigned pg_idx = 0; |
779 | |
780 | while (done < total) { |
781 | struct bio_vec bv = bio_iter_iovec(data->bio, data->iter); |
782 | unsigned int bytes = min3(bv.bv_len, (unsigned)total - done, |
783 | (unsigned)(PAGE_SIZE - pg_off)); |
784 | void *bv_buf = bvec_kmap_local(bvec: &bv); |
785 | void *pg_buf = kmap_local_page(page: data->pages[pg_idx]); |
786 | |
787 | if (dir == ITER_DEST) |
788 | memcpy(pg_buf + pg_off, bv_buf, bytes); |
789 | else |
790 | memcpy(bv_buf, pg_buf + pg_off, bytes); |
791 | |
792 | kunmap_local(pg_buf); |
793 | kunmap_local(bv_buf); |
794 | |
795 | /* advance page array */ |
796 | pg_off += bytes; |
797 | if (pg_off == PAGE_SIZE) { |
798 | pg_idx += 1; |
799 | pg_off = 0; |
800 | } |
801 | |
802 | done += bytes; |
803 | |
804 | /* advance bio */ |
805 | bio_advance_iter_single(bio: data->bio, iter: &data->iter, bytes); |
806 | if (!data->iter.bi_size) { |
807 | data->bio = data->bio->bi_next; |
808 | if (data->bio == NULL) |
809 | break; |
810 | data->iter = data->bio->bi_iter; |
811 | } |
812 | } |
813 | } |
814 | |
815 | static bool ublk_advance_io_iter(const struct request *req, |
816 | struct ublk_io_iter *iter, unsigned int offset) |
817 | { |
818 | struct bio *bio = req->bio; |
819 | |
820 | for_each_bio(bio) { |
821 | if (bio->bi_iter.bi_size > offset) { |
822 | iter->bio = bio; |
823 | iter->iter = bio->bi_iter; |
824 | bio_advance_iter(bio: iter->bio, iter: &iter->iter, bytes: offset); |
825 | return true; |
826 | } |
827 | offset -= bio->bi_iter.bi_size; |
828 | } |
829 | return false; |
830 | } |
831 | |
832 | /* |
833 | * Copy data between request pages and io_iter, and 'offset' |
834 | * is the start point of linear offset of request. |
835 | */ |
836 | static size_t ublk_copy_user_pages(const struct request *req, |
837 | unsigned offset, struct iov_iter *uiter, int dir) |
838 | { |
839 | struct ublk_io_iter iter; |
840 | size_t done = 0; |
841 | |
842 | if (!ublk_advance_io_iter(req, iter: &iter, offset)) |
843 | return 0; |
844 | |
845 | while (iov_iter_count(i: uiter) && iter.bio) { |
846 | unsigned nr_pages; |
847 | ssize_t len; |
848 | size_t off; |
849 | int i; |
850 | |
851 | len = iov_iter_get_pages2(i: uiter, pages: iter.pages, |
852 | maxsize: iov_iter_count(i: uiter), |
853 | UBLK_MAX_PIN_PAGES, start: &off); |
854 | if (len <= 0) |
855 | return done; |
856 | |
857 | ublk_copy_io_pages(data: &iter, total: len, pg_off: off, dir); |
858 | nr_pages = DIV_ROUND_UP(len + off, PAGE_SIZE); |
859 | for (i = 0; i < nr_pages; i++) { |
860 | if (dir == ITER_DEST) |
861 | set_page_dirty(iter.pages[i]); |
862 | put_page(page: iter.pages[i]); |
863 | } |
864 | done += len; |
865 | } |
866 | |
867 | return done; |
868 | } |
869 | |
870 | static inline bool ublk_need_map_req(const struct request *req) |
871 | { |
872 | return ublk_rq_has_data(rq: req) && req_op(req) == REQ_OP_WRITE; |
873 | } |
874 | |
875 | static inline bool ublk_need_unmap_req(const struct request *req) |
876 | { |
877 | return ublk_rq_has_data(rq: req) && |
878 | (req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_DRV_IN); |
879 | } |
880 | |
881 | static int ublk_map_io(const struct ublk_queue *ubq, const struct request *req, |
882 | struct ublk_io *io) |
883 | { |
884 | const unsigned int rq_bytes = blk_rq_bytes(rq: req); |
885 | |
886 | if (ublk_support_user_copy(ubq)) |
887 | return rq_bytes; |
888 | |
889 | /* |
890 | * no zero copy, we delay copy WRITE request data into ublksrv |
891 | * context and the big benefit is that pinning pages in current |
892 | * context is pretty fast, see ublk_pin_user_pages |
893 | */ |
894 | if (ublk_need_map_req(req)) { |
895 | struct iov_iter iter; |
896 | struct iovec iov; |
897 | const int dir = ITER_DEST; |
898 | |
899 | import_single_range(type: dir, u64_to_user_ptr(io->addr), len: rq_bytes, |
900 | iov: &iov, i: &iter); |
901 | |
902 | return ublk_copy_user_pages(req, offset: 0, uiter: &iter, dir); |
903 | } |
904 | return rq_bytes; |
905 | } |
906 | |
907 | static int ublk_unmap_io(const struct ublk_queue *ubq, |
908 | const struct request *req, |
909 | struct ublk_io *io) |
910 | { |
911 | const unsigned int rq_bytes = blk_rq_bytes(rq: req); |
912 | |
913 | if (ublk_support_user_copy(ubq)) |
914 | return rq_bytes; |
915 | |
916 | if (ublk_need_unmap_req(req)) { |
917 | struct iov_iter iter; |
918 | struct iovec iov; |
919 | const int dir = ITER_SOURCE; |
920 | |
921 | WARN_ON_ONCE(io->res > rq_bytes); |
922 | |
923 | import_single_range(type: dir, u64_to_user_ptr(io->addr), len: io->res, |
924 | iov: &iov, i: &iter); |
925 | return ublk_copy_user_pages(req, offset: 0, uiter: &iter, dir); |
926 | } |
927 | return rq_bytes; |
928 | } |
929 | |
930 | static inline unsigned int ublk_req_build_flags(struct request *req) |
931 | { |
932 | unsigned flags = 0; |
933 | |
934 | if (req->cmd_flags & REQ_FAILFAST_DEV) |
935 | flags |= UBLK_IO_F_FAILFAST_DEV; |
936 | |
937 | if (req->cmd_flags & REQ_FAILFAST_TRANSPORT) |
938 | flags |= UBLK_IO_F_FAILFAST_TRANSPORT; |
939 | |
940 | if (req->cmd_flags & REQ_FAILFAST_DRIVER) |
941 | flags |= UBLK_IO_F_FAILFAST_DRIVER; |
942 | |
943 | if (req->cmd_flags & REQ_META) |
944 | flags |= UBLK_IO_F_META; |
945 | |
946 | if (req->cmd_flags & REQ_FUA) |
947 | flags |= UBLK_IO_F_FUA; |
948 | |
949 | if (req->cmd_flags & REQ_NOUNMAP) |
950 | flags |= UBLK_IO_F_NOUNMAP; |
951 | |
952 | if (req->cmd_flags & REQ_SWAP) |
953 | flags |= UBLK_IO_F_SWAP; |
954 | |
955 | return flags; |
956 | } |
957 | |
958 | static blk_status_t ublk_setup_iod(struct ublk_queue *ubq, struct request *req) |
959 | { |
960 | struct ublksrv_io_desc *iod = ublk_get_iod(ubq, tag: req->tag); |
961 | struct ublk_io *io = &ubq->ios[req->tag]; |
962 | enum req_op op = req_op(req); |
963 | u32 ublk_op; |
964 | |
965 | if (!ublk_queue_is_zoned(ubq) && |
966 | (op_is_zone_mgmt(op) || op == REQ_OP_ZONE_APPEND)) |
967 | return BLK_STS_IOERR; |
968 | |
969 | switch (req_op(req)) { |
970 | case REQ_OP_READ: |
971 | ublk_op = UBLK_IO_OP_READ; |
972 | break; |
973 | case REQ_OP_WRITE: |
974 | ublk_op = UBLK_IO_OP_WRITE; |
975 | break; |
976 | case REQ_OP_FLUSH: |
977 | ublk_op = UBLK_IO_OP_FLUSH; |
978 | break; |
979 | case REQ_OP_DISCARD: |
980 | ublk_op = UBLK_IO_OP_DISCARD; |
981 | break; |
982 | case REQ_OP_WRITE_ZEROES: |
983 | ublk_op = UBLK_IO_OP_WRITE_ZEROES; |
984 | break; |
985 | default: |
986 | if (ublk_queue_is_zoned(ubq)) |
987 | return ublk_setup_iod_zoned(ubq, req); |
988 | return BLK_STS_IOERR; |
989 | } |
990 | |
991 | /* need to translate since kernel may change */ |
992 | iod->op_flags = ublk_op | ublk_req_build_flags(req); |
993 | iod->nr_sectors = blk_rq_sectors(rq: req); |
994 | iod->start_sector = blk_rq_pos(rq: req); |
995 | iod->addr = io->addr; |
996 | |
997 | return BLK_STS_OK; |
998 | } |
999 | |
1000 | static inline struct ublk_uring_cmd_pdu *ublk_get_uring_cmd_pdu( |
1001 | struct io_uring_cmd *ioucmd) |
1002 | { |
1003 | return (struct ublk_uring_cmd_pdu *)&ioucmd->pdu; |
1004 | } |
1005 | |
1006 | static inline bool ubq_daemon_is_dying(struct ublk_queue *ubq) |
1007 | { |
1008 | return ubq->ubq_daemon->flags & PF_EXITING; |
1009 | } |
1010 | |
1011 | /* todo: handle partial completion */ |
1012 | static inline void __ublk_complete_rq(struct request *req) |
1013 | { |
1014 | struct ublk_queue *ubq = req->mq_hctx->driver_data; |
1015 | struct ublk_io *io = &ubq->ios[req->tag]; |
1016 | unsigned int unmapped_bytes; |
1017 | blk_status_t res = BLK_STS_OK; |
1018 | |
1019 | /* called from ublk_abort_queue() code path */ |
1020 | if (io->flags & UBLK_IO_FLAG_ABORTED) { |
1021 | res = BLK_STS_IOERR; |
1022 | goto exit; |
1023 | } |
1024 | |
1025 | /* failed read IO if nothing is read */ |
1026 | if (!io->res && req_op(req) == REQ_OP_READ) |
1027 | io->res = -EIO; |
1028 | |
1029 | if (io->res < 0) { |
1030 | res = errno_to_blk_status(errno: io->res); |
1031 | goto exit; |
1032 | } |
1033 | |
1034 | /* |
1035 | * FLUSH, DISCARD or WRITE_ZEROES usually won't return bytes returned, so end them |
1036 | * directly. |
1037 | * |
1038 | * Both the two needn't unmap. |
1039 | */ |
1040 | if (req_op(req) != REQ_OP_READ && req_op(req) != REQ_OP_WRITE && |
1041 | req_op(req) != REQ_OP_DRV_IN) |
1042 | goto exit; |
1043 | |
1044 | /* for READ request, writing data in iod->addr to rq buffers */ |
1045 | unmapped_bytes = ublk_unmap_io(ubq, req, io); |
1046 | |
1047 | /* |
1048 | * Extremely impossible since we got data filled in just before |
1049 | * |
1050 | * Re-read simply for this unlikely case. |
1051 | */ |
1052 | if (unlikely(unmapped_bytes < io->res)) |
1053 | io->res = unmapped_bytes; |
1054 | |
1055 | if (blk_update_request(rq: req, BLK_STS_OK, nr_bytes: io->res)) |
1056 | blk_mq_requeue_request(rq: req, kick_requeue_list: true); |
1057 | else |
1058 | __blk_mq_end_request(rq: req, BLK_STS_OK); |
1059 | |
1060 | return; |
1061 | exit: |
1062 | blk_mq_end_request(rq: req, error: res); |
1063 | } |
1064 | |
1065 | static void ublk_complete_rq(struct kref *ref) |
1066 | { |
1067 | struct ublk_rq_data *data = container_of(ref, struct ublk_rq_data, |
1068 | ref); |
1069 | struct request *req = blk_mq_rq_from_pdu(pdu: data); |
1070 | |
1071 | __ublk_complete_rq(req); |
1072 | } |
1073 | |
1074 | /* |
1075 | * Since __ublk_rq_task_work always fails requests immediately during |
1076 | * exiting, __ublk_fail_req() is only called from abort context during |
1077 | * exiting. So lock is unnecessary. |
1078 | * |
1079 | * Also aborting may not be started yet, keep in mind that one failed |
1080 | * request may be issued by block layer again. |
1081 | */ |
1082 | static void __ublk_fail_req(struct ublk_queue *ubq, struct ublk_io *io, |
1083 | struct request *req) |
1084 | { |
1085 | WARN_ON_ONCE(io->flags & UBLK_IO_FLAG_ACTIVE); |
1086 | |
1087 | if (ublk_queue_can_use_recovery_reissue(ubq)) |
1088 | blk_mq_requeue_request(rq: req, kick_requeue_list: false); |
1089 | else |
1090 | ublk_put_req_ref(ubq, req); |
1091 | } |
1092 | |
1093 | static void ubq_complete_io_cmd(struct ublk_io *io, int res, |
1094 | unsigned issue_flags) |
1095 | { |
1096 | /* mark this cmd owned by ublksrv */ |
1097 | io->flags |= UBLK_IO_FLAG_OWNED_BY_SRV; |
1098 | |
1099 | /* |
1100 | * clear ACTIVE since we are done with this sqe/cmd slot |
1101 | * We can only accept io cmd in case of being not active. |
1102 | */ |
1103 | io->flags &= ~UBLK_IO_FLAG_ACTIVE; |
1104 | |
1105 | /* tell ublksrv one io request is coming */ |
1106 | io_uring_cmd_done(cmd: io->cmd, ret: res, res2: 0, issue_flags); |
1107 | } |
1108 | |
1109 | #define UBLK_REQUEUE_DELAY_MS 3 |
1110 | |
1111 | static inline void __ublk_abort_rq(struct ublk_queue *ubq, |
1112 | struct request *rq) |
1113 | { |
1114 | /* We cannot process this rq so just requeue it. */ |
1115 | if (ublk_queue_can_use_recovery(ubq)) |
1116 | blk_mq_requeue_request(rq, kick_requeue_list: false); |
1117 | else |
1118 | blk_mq_end_request(rq, BLK_STS_IOERR); |
1119 | } |
1120 | |
1121 | static inline void __ublk_rq_task_work(struct request *req, |
1122 | unsigned issue_flags) |
1123 | { |
1124 | struct ublk_queue *ubq = req->mq_hctx->driver_data; |
1125 | int tag = req->tag; |
1126 | struct ublk_io *io = &ubq->ios[tag]; |
1127 | unsigned int mapped_bytes; |
1128 | |
1129 | pr_devel("%s: complete: op %d, qid %d tag %d io_flags %x addr %llx\n" , |
1130 | __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, |
1131 | ublk_get_iod(ubq, req->tag)->addr); |
1132 | |
1133 | /* |
1134 | * Task is exiting if either: |
1135 | * |
1136 | * (1) current != ubq_daemon. |
1137 | * io_uring_cmd_complete_in_task() tries to run task_work |
1138 | * in a workqueue if ubq_daemon(cmd's task) is PF_EXITING. |
1139 | * |
1140 | * (2) current->flags & PF_EXITING. |
1141 | */ |
1142 | if (unlikely(current != ubq->ubq_daemon || current->flags & PF_EXITING)) { |
1143 | __ublk_abort_rq(ubq, rq: req); |
1144 | return; |
1145 | } |
1146 | |
1147 | if (ublk_need_get_data(ubq) && ublk_need_map_req(req)) { |
1148 | /* |
1149 | * We have not handled UBLK_IO_NEED_GET_DATA command yet, |
1150 | * so immepdately pass UBLK_IO_RES_NEED_GET_DATA to ublksrv |
1151 | * and notify it. |
1152 | */ |
1153 | if (!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA)) { |
1154 | io->flags |= UBLK_IO_FLAG_NEED_GET_DATA; |
1155 | pr_devel("%s: need get data. op %d, qid %d tag %d io_flags %x\n" , |
1156 | __func__, io->cmd->cmd_op, ubq->q_id, |
1157 | req->tag, io->flags); |
1158 | ubq_complete_io_cmd(io, UBLK_IO_RES_NEED_GET_DATA, issue_flags); |
1159 | return; |
1160 | } |
1161 | /* |
1162 | * We have handled UBLK_IO_NEED_GET_DATA command, |
1163 | * so clear UBLK_IO_FLAG_NEED_GET_DATA now and just |
1164 | * do the copy work. |
1165 | */ |
1166 | io->flags &= ~UBLK_IO_FLAG_NEED_GET_DATA; |
1167 | /* update iod->addr because ublksrv may have passed a new io buffer */ |
1168 | ublk_get_iod(ubq, tag: req->tag)->addr = io->addr; |
1169 | pr_devel("%s: update iod->addr: op %d, qid %d tag %d io_flags %x addr %llx\n" , |
1170 | __func__, io->cmd->cmd_op, ubq->q_id, req->tag, io->flags, |
1171 | ublk_get_iod(ubq, req->tag)->addr); |
1172 | } |
1173 | |
1174 | mapped_bytes = ublk_map_io(ubq, req, io); |
1175 | |
1176 | /* partially mapped, update io descriptor */ |
1177 | if (unlikely(mapped_bytes != blk_rq_bytes(req))) { |
1178 | /* |
1179 | * Nothing mapped, retry until we succeed. |
1180 | * |
1181 | * We may never succeed in mapping any bytes here because |
1182 | * of OOM. TODO: reserve one buffer with single page pinned |
1183 | * for providing forward progress guarantee. |
1184 | */ |
1185 | if (unlikely(!mapped_bytes)) { |
1186 | blk_mq_requeue_request(rq: req, kick_requeue_list: false); |
1187 | blk_mq_delay_kick_requeue_list(q: req->q, |
1188 | UBLK_REQUEUE_DELAY_MS); |
1189 | return; |
1190 | } |
1191 | |
1192 | ublk_get_iod(ubq, tag: req->tag)->nr_sectors = |
1193 | mapped_bytes >> 9; |
1194 | } |
1195 | |
1196 | ublk_init_req_ref(ubq, req); |
1197 | ubq_complete_io_cmd(io, UBLK_IO_RES_OK, issue_flags); |
1198 | } |
1199 | |
1200 | static inline void ublk_forward_io_cmds(struct ublk_queue *ubq, |
1201 | unsigned issue_flags) |
1202 | { |
1203 | struct llist_node *io_cmds = llist_del_all(head: &ubq->io_cmds); |
1204 | struct ublk_rq_data *data, *tmp; |
1205 | |
1206 | io_cmds = llist_reverse_order(head: io_cmds); |
1207 | llist_for_each_entry_safe(data, tmp, io_cmds, node) |
1208 | __ublk_rq_task_work(req: blk_mq_rq_from_pdu(pdu: data), issue_flags); |
1209 | } |
1210 | |
1211 | static void ublk_rq_task_work_cb(struct io_uring_cmd *cmd, unsigned issue_flags) |
1212 | { |
1213 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(ioucmd: cmd); |
1214 | struct ublk_queue *ubq = pdu->ubq; |
1215 | |
1216 | ublk_forward_io_cmds(ubq, issue_flags); |
1217 | } |
1218 | |
1219 | static void ublk_queue_cmd(struct ublk_queue *ubq, struct request *rq) |
1220 | { |
1221 | struct ublk_rq_data *data = blk_mq_rq_to_pdu(rq); |
1222 | |
1223 | if (llist_add(new: &data->node, head: &ubq->io_cmds)) { |
1224 | struct ublk_io *io = &ubq->ios[rq->tag]; |
1225 | |
1226 | io_uring_cmd_complete_in_task(ioucmd: io->cmd, task_work_cb: ublk_rq_task_work_cb); |
1227 | } |
1228 | } |
1229 | |
1230 | static enum blk_eh_timer_return ublk_timeout(struct request *rq) |
1231 | { |
1232 | struct ublk_queue *ubq = rq->mq_hctx->driver_data; |
1233 | unsigned int nr_inflight = 0; |
1234 | int i; |
1235 | |
1236 | if (ubq->flags & UBLK_F_UNPRIVILEGED_DEV) { |
1237 | if (!ubq->timeout) { |
1238 | send_sig(SIGKILL, ubq->ubq_daemon, 0); |
1239 | ubq->timeout = true; |
1240 | } |
1241 | |
1242 | return BLK_EH_DONE; |
1243 | } |
1244 | |
1245 | if (!ubq_daemon_is_dying(ubq)) |
1246 | return BLK_EH_RESET_TIMER; |
1247 | |
1248 | for (i = 0; i < ubq->q_depth; i++) { |
1249 | struct ublk_io *io = &ubq->ios[i]; |
1250 | |
1251 | if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) |
1252 | nr_inflight++; |
1253 | } |
1254 | |
1255 | /* cancelable uring_cmd can't help us if all commands are in-flight */ |
1256 | if (nr_inflight == ubq->q_depth) { |
1257 | struct ublk_device *ub = ubq->dev; |
1258 | |
1259 | if (ublk_abort_requests(ub, ubq)) { |
1260 | if (ublk_can_use_recovery(ub)) |
1261 | schedule_work(work: &ub->quiesce_work); |
1262 | else |
1263 | schedule_work(work: &ub->stop_work); |
1264 | } |
1265 | return BLK_EH_DONE; |
1266 | } |
1267 | |
1268 | return BLK_EH_RESET_TIMER; |
1269 | } |
1270 | |
1271 | static blk_status_t ublk_queue_rq(struct blk_mq_hw_ctx *hctx, |
1272 | const struct blk_mq_queue_data *bd) |
1273 | { |
1274 | struct ublk_queue *ubq = hctx->driver_data; |
1275 | struct request *rq = bd->rq; |
1276 | blk_status_t res; |
1277 | |
1278 | /* fill iod to slot in io cmd buffer */ |
1279 | res = ublk_setup_iod(ubq, req: rq); |
1280 | if (unlikely(res != BLK_STS_OK)) |
1281 | return BLK_STS_IOERR; |
1282 | |
1283 | /* With recovery feature enabled, force_abort is set in |
1284 | * ublk_stop_dev() before calling del_gendisk(). We have to |
1285 | * abort all requeued and new rqs here to let del_gendisk() |
1286 | * move on. Besides, we cannot not call io_uring_cmd_complete_in_task() |
1287 | * to avoid UAF on io_uring ctx. |
1288 | * |
1289 | * Note: force_abort is guaranteed to be seen because it is set |
1290 | * before request queue is unqiuesced. |
1291 | */ |
1292 | if (ublk_queue_can_use_recovery(ubq) && unlikely(ubq->force_abort)) |
1293 | return BLK_STS_IOERR; |
1294 | |
1295 | if (unlikely(ubq->canceling)) { |
1296 | __ublk_abort_rq(ubq, rq); |
1297 | return BLK_STS_OK; |
1298 | } |
1299 | |
1300 | blk_mq_start_request(rq: bd->rq); |
1301 | ublk_queue_cmd(ubq, rq); |
1302 | |
1303 | return BLK_STS_OK; |
1304 | } |
1305 | |
1306 | static int ublk_init_hctx(struct blk_mq_hw_ctx *hctx, void *driver_data, |
1307 | unsigned int hctx_idx) |
1308 | { |
1309 | struct ublk_device *ub = driver_data; |
1310 | struct ublk_queue *ubq = ublk_get_queue(dev: ub, qid: hctx->queue_num); |
1311 | |
1312 | hctx->driver_data = ubq; |
1313 | return 0; |
1314 | } |
1315 | |
1316 | static const struct blk_mq_ops ublk_mq_ops = { |
1317 | .queue_rq = ublk_queue_rq, |
1318 | .init_hctx = ublk_init_hctx, |
1319 | .timeout = ublk_timeout, |
1320 | }; |
1321 | |
1322 | static int ublk_ch_open(struct inode *inode, struct file *filp) |
1323 | { |
1324 | struct ublk_device *ub = container_of(inode->i_cdev, |
1325 | struct ublk_device, cdev); |
1326 | |
1327 | if (test_and_set_bit(UB_STATE_OPEN, addr: &ub->state)) |
1328 | return -EBUSY; |
1329 | filp->private_data = ub; |
1330 | return 0; |
1331 | } |
1332 | |
1333 | static int ublk_ch_release(struct inode *inode, struct file *filp) |
1334 | { |
1335 | struct ublk_device *ub = filp->private_data; |
1336 | |
1337 | clear_bit(UB_STATE_OPEN, addr: &ub->state); |
1338 | return 0; |
1339 | } |
1340 | |
1341 | /* map pre-allocated per-queue cmd buffer to ublksrv daemon */ |
1342 | static int ublk_ch_mmap(struct file *filp, struct vm_area_struct *vma) |
1343 | { |
1344 | struct ublk_device *ub = filp->private_data; |
1345 | size_t sz = vma->vm_end - vma->vm_start; |
1346 | unsigned max_sz = UBLK_MAX_QUEUE_DEPTH * sizeof(struct ublksrv_io_desc); |
1347 | unsigned long pfn, end, phys_off = vma->vm_pgoff << PAGE_SHIFT; |
1348 | int q_id, ret = 0; |
1349 | |
1350 | spin_lock(lock: &ub->lock); |
1351 | if (!ub->mm) |
1352 | ub->mm = current->mm; |
1353 | if (current->mm != ub->mm) |
1354 | ret = -EINVAL; |
1355 | spin_unlock(lock: &ub->lock); |
1356 | |
1357 | if (ret) |
1358 | return ret; |
1359 | |
1360 | if (vma->vm_flags & VM_WRITE) |
1361 | return -EPERM; |
1362 | |
1363 | end = UBLKSRV_CMD_BUF_OFFSET + ub->dev_info.nr_hw_queues * max_sz; |
1364 | if (phys_off < UBLKSRV_CMD_BUF_OFFSET || phys_off >= end) |
1365 | return -EINVAL; |
1366 | |
1367 | q_id = (phys_off - UBLKSRV_CMD_BUF_OFFSET) / max_sz; |
1368 | pr_devel("%s: qid %d, pid %d, addr %lx pg_off %lx sz %lu\n" , |
1369 | __func__, q_id, current->pid, vma->vm_start, |
1370 | phys_off, (unsigned long)sz); |
1371 | |
1372 | if (sz != ublk_queue_cmd_buf_size(ub, q_id)) |
1373 | return -EINVAL; |
1374 | |
1375 | pfn = virt_to_phys(address: ublk_queue_cmd_buf(ub, q_id)) >> PAGE_SHIFT; |
1376 | return remap_pfn_range(vma, addr: vma->vm_start, pfn, size: sz, vma->vm_page_prot); |
1377 | } |
1378 | |
1379 | static void ublk_commit_completion(struct ublk_device *ub, |
1380 | const struct ublksrv_io_cmd *ub_cmd) |
1381 | { |
1382 | u32 qid = ub_cmd->q_id, tag = ub_cmd->tag; |
1383 | struct ublk_queue *ubq = ublk_get_queue(dev: ub, qid); |
1384 | struct ublk_io *io = &ubq->ios[tag]; |
1385 | struct request *req; |
1386 | |
1387 | /* now this cmd slot is owned by nbd driver */ |
1388 | io->flags &= ~UBLK_IO_FLAG_OWNED_BY_SRV; |
1389 | io->res = ub_cmd->result; |
1390 | |
1391 | /* find the io request and complete */ |
1392 | req = blk_mq_tag_to_rq(tags: ub->tag_set.tags[qid], tag); |
1393 | if (WARN_ON_ONCE(unlikely(!req))) |
1394 | return; |
1395 | |
1396 | if (req_op(req) == REQ_OP_ZONE_APPEND) |
1397 | req->__sector = ub_cmd->zone_append_lba; |
1398 | |
1399 | if (likely(!blk_should_fake_timeout(req->q))) |
1400 | ublk_put_req_ref(ubq, req); |
1401 | } |
1402 | |
1403 | /* |
1404 | * Called from ubq_daemon context via cancel fn, meantime quiesce ublk |
1405 | * blk-mq queue, so we are called exclusively with blk-mq and ubq_daemon |
1406 | * context, so everything is serialized. |
1407 | */ |
1408 | static void ublk_abort_queue(struct ublk_device *ub, struct ublk_queue *ubq) |
1409 | { |
1410 | int i; |
1411 | |
1412 | for (i = 0; i < ubq->q_depth; i++) { |
1413 | struct ublk_io *io = &ubq->ios[i]; |
1414 | |
1415 | if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) { |
1416 | struct request *rq; |
1417 | |
1418 | /* |
1419 | * Either we fail the request or ublk_rq_task_work_fn |
1420 | * will do it |
1421 | */ |
1422 | rq = blk_mq_tag_to_rq(tags: ub->tag_set.tags[ubq->q_id], tag: i); |
1423 | if (rq && blk_mq_request_started(rq)) { |
1424 | io->flags |= UBLK_IO_FLAG_ABORTED; |
1425 | __ublk_fail_req(ubq, io, req: rq); |
1426 | } |
1427 | } |
1428 | } |
1429 | } |
1430 | |
1431 | static bool ublk_abort_requests(struct ublk_device *ub, struct ublk_queue *ubq) |
1432 | { |
1433 | struct gendisk *disk; |
1434 | |
1435 | spin_lock(lock: &ubq->cancel_lock); |
1436 | if (ubq->canceling) { |
1437 | spin_unlock(lock: &ubq->cancel_lock); |
1438 | return false; |
1439 | } |
1440 | ubq->canceling = true; |
1441 | spin_unlock(lock: &ubq->cancel_lock); |
1442 | |
1443 | spin_lock(lock: &ub->lock); |
1444 | disk = ub->ub_disk; |
1445 | if (disk) |
1446 | get_device(disk_to_dev(disk)); |
1447 | spin_unlock(lock: &ub->lock); |
1448 | |
1449 | /* Our disk has been dead */ |
1450 | if (!disk) |
1451 | return false; |
1452 | |
1453 | /* Now we are serialized with ublk_queue_rq() */ |
1454 | blk_mq_quiesce_queue(q: disk->queue); |
1455 | /* abort queue is for making forward progress */ |
1456 | ublk_abort_queue(ub, ubq); |
1457 | blk_mq_unquiesce_queue(q: disk->queue); |
1458 | put_device(disk_to_dev(disk)); |
1459 | |
1460 | return true; |
1461 | } |
1462 | |
1463 | static void ublk_cancel_cmd(struct ublk_queue *ubq, struct ublk_io *io, |
1464 | unsigned int issue_flags) |
1465 | { |
1466 | bool done; |
1467 | |
1468 | if (!(io->flags & UBLK_IO_FLAG_ACTIVE)) |
1469 | return; |
1470 | |
1471 | spin_lock(lock: &ubq->cancel_lock); |
1472 | done = !!(io->flags & UBLK_IO_FLAG_CANCELED); |
1473 | if (!done) |
1474 | io->flags |= UBLK_IO_FLAG_CANCELED; |
1475 | spin_unlock(lock: &ubq->cancel_lock); |
1476 | |
1477 | if (!done) |
1478 | io_uring_cmd_done(cmd: io->cmd, UBLK_IO_RES_ABORT, res2: 0, issue_flags); |
1479 | } |
1480 | |
1481 | /* |
1482 | * The ublk char device won't be closed when calling cancel fn, so both |
1483 | * ublk device and queue are guaranteed to be live |
1484 | */ |
1485 | static void ublk_uring_cmd_cancel_fn(struct io_uring_cmd *cmd, |
1486 | unsigned int issue_flags) |
1487 | { |
1488 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(ioucmd: cmd); |
1489 | struct ublk_queue *ubq = pdu->ubq; |
1490 | struct task_struct *task; |
1491 | struct ublk_device *ub; |
1492 | bool need_schedule; |
1493 | struct ublk_io *io; |
1494 | |
1495 | if (WARN_ON_ONCE(!ubq)) |
1496 | return; |
1497 | |
1498 | if (WARN_ON_ONCE(pdu->tag >= ubq->q_depth)) |
1499 | return; |
1500 | |
1501 | task = io_uring_cmd_get_task(cmd); |
1502 | if (WARN_ON_ONCE(task && task != ubq->ubq_daemon)) |
1503 | return; |
1504 | |
1505 | ub = ubq->dev; |
1506 | need_schedule = ublk_abort_requests(ub, ubq); |
1507 | |
1508 | io = &ubq->ios[pdu->tag]; |
1509 | WARN_ON_ONCE(io->cmd != cmd); |
1510 | ublk_cancel_cmd(ubq, io, issue_flags); |
1511 | |
1512 | if (need_schedule) { |
1513 | if (ublk_can_use_recovery(ub)) |
1514 | schedule_work(work: &ub->quiesce_work); |
1515 | else |
1516 | schedule_work(work: &ub->stop_work); |
1517 | } |
1518 | } |
1519 | |
1520 | static inline bool ublk_queue_ready(struct ublk_queue *ubq) |
1521 | { |
1522 | return ubq->nr_io_ready == ubq->q_depth; |
1523 | } |
1524 | |
1525 | static void ublk_cancel_queue(struct ublk_queue *ubq) |
1526 | { |
1527 | int i; |
1528 | |
1529 | for (i = 0; i < ubq->q_depth; i++) |
1530 | ublk_cancel_cmd(ubq, io: &ubq->ios[i], issue_flags: IO_URING_F_UNLOCKED); |
1531 | } |
1532 | |
1533 | /* Cancel all pending commands, must be called after del_gendisk() returns */ |
1534 | static void ublk_cancel_dev(struct ublk_device *ub) |
1535 | { |
1536 | int i; |
1537 | |
1538 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) |
1539 | ublk_cancel_queue(ubq: ublk_get_queue(dev: ub, qid: i)); |
1540 | } |
1541 | |
1542 | static bool ublk_check_inflight_rq(struct request *rq, void *data) |
1543 | { |
1544 | bool *idle = data; |
1545 | |
1546 | if (blk_mq_request_started(rq)) { |
1547 | *idle = false; |
1548 | return false; |
1549 | } |
1550 | return true; |
1551 | } |
1552 | |
1553 | static void ublk_wait_tagset_rqs_idle(struct ublk_device *ub) |
1554 | { |
1555 | bool idle; |
1556 | |
1557 | WARN_ON_ONCE(!blk_queue_quiesced(ub->ub_disk->queue)); |
1558 | while (true) { |
1559 | idle = true; |
1560 | blk_mq_tagset_busy_iter(tagset: &ub->tag_set, |
1561 | fn: ublk_check_inflight_rq, priv: &idle); |
1562 | if (idle) |
1563 | break; |
1564 | msleep(UBLK_REQUEUE_DELAY_MS); |
1565 | } |
1566 | } |
1567 | |
1568 | static void __ublk_quiesce_dev(struct ublk_device *ub) |
1569 | { |
1570 | pr_devel("%s: quiesce ub: dev_id %d state %s\n" , |
1571 | __func__, ub->dev_info.dev_id, |
1572 | ub->dev_info.state == UBLK_S_DEV_LIVE ? |
1573 | "LIVE" : "QUIESCED" ); |
1574 | blk_mq_quiesce_queue(q: ub->ub_disk->queue); |
1575 | ublk_wait_tagset_rqs_idle(ub); |
1576 | ub->dev_info.state = UBLK_S_DEV_QUIESCED; |
1577 | } |
1578 | |
1579 | static void ublk_quiesce_work_fn(struct work_struct *work) |
1580 | { |
1581 | struct ublk_device *ub = |
1582 | container_of(work, struct ublk_device, quiesce_work); |
1583 | |
1584 | mutex_lock(&ub->mutex); |
1585 | if (ub->dev_info.state != UBLK_S_DEV_LIVE) |
1586 | goto unlock; |
1587 | __ublk_quiesce_dev(ub); |
1588 | unlock: |
1589 | mutex_unlock(lock: &ub->mutex); |
1590 | ublk_cancel_dev(ub); |
1591 | } |
1592 | |
1593 | static void ublk_unquiesce_dev(struct ublk_device *ub) |
1594 | { |
1595 | int i; |
1596 | |
1597 | pr_devel("%s: unquiesce ub: dev_id %d state %s\n" , |
1598 | __func__, ub->dev_info.dev_id, |
1599 | ub->dev_info.state == UBLK_S_DEV_LIVE ? |
1600 | "LIVE" : "QUIESCED" ); |
1601 | /* quiesce_work has run. We let requeued rqs be aborted |
1602 | * before running fallback_wq. "force_abort" must be seen |
1603 | * after request queue is unqiuesced. Then del_gendisk() |
1604 | * can move on. |
1605 | */ |
1606 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) |
1607 | ublk_get_queue(dev: ub, qid: i)->force_abort = true; |
1608 | |
1609 | blk_mq_unquiesce_queue(q: ub->ub_disk->queue); |
1610 | /* We may have requeued some rqs in ublk_quiesce_queue() */ |
1611 | blk_mq_kick_requeue_list(q: ub->ub_disk->queue); |
1612 | } |
1613 | |
1614 | static void ublk_stop_dev(struct ublk_device *ub) |
1615 | { |
1616 | struct gendisk *disk; |
1617 | |
1618 | mutex_lock(&ub->mutex); |
1619 | if (ub->dev_info.state == UBLK_S_DEV_DEAD) |
1620 | goto unlock; |
1621 | if (ublk_can_use_recovery(ub)) { |
1622 | if (ub->dev_info.state == UBLK_S_DEV_LIVE) |
1623 | __ublk_quiesce_dev(ub); |
1624 | ublk_unquiesce_dev(ub); |
1625 | } |
1626 | del_gendisk(gp: ub->ub_disk); |
1627 | |
1628 | /* Sync with ublk_abort_queue() by holding the lock */ |
1629 | spin_lock(lock: &ub->lock); |
1630 | disk = ub->ub_disk; |
1631 | ub->dev_info.state = UBLK_S_DEV_DEAD; |
1632 | ub->dev_info.ublksrv_pid = -1; |
1633 | ub->ub_disk = NULL; |
1634 | spin_unlock(lock: &ub->lock); |
1635 | put_disk(disk); |
1636 | unlock: |
1637 | mutex_unlock(lock: &ub->mutex); |
1638 | ublk_cancel_dev(ub); |
1639 | } |
1640 | |
1641 | /* device can only be started after all IOs are ready */ |
1642 | static void ublk_mark_io_ready(struct ublk_device *ub, struct ublk_queue *ubq) |
1643 | { |
1644 | mutex_lock(&ub->mutex); |
1645 | ubq->nr_io_ready++; |
1646 | if (ublk_queue_ready(ubq)) { |
1647 | ubq->ubq_daemon = current; |
1648 | get_task_struct(t: ubq->ubq_daemon); |
1649 | ub->nr_queues_ready++; |
1650 | |
1651 | if (capable(CAP_SYS_ADMIN)) |
1652 | ub->nr_privileged_daemon++; |
1653 | } |
1654 | if (ub->nr_queues_ready == ub->dev_info.nr_hw_queues) |
1655 | complete_all(&ub->completion); |
1656 | mutex_unlock(lock: &ub->mutex); |
1657 | } |
1658 | |
1659 | static void ublk_handle_need_get_data(struct ublk_device *ub, int q_id, |
1660 | int tag) |
1661 | { |
1662 | struct ublk_queue *ubq = ublk_get_queue(dev: ub, qid: q_id); |
1663 | struct request *req = blk_mq_tag_to_rq(tags: ub->tag_set.tags[q_id], tag); |
1664 | |
1665 | ublk_queue_cmd(ubq, rq: req); |
1666 | } |
1667 | |
1668 | static inline int ublk_check_cmd_op(u32 cmd_op) |
1669 | { |
1670 | u32 ioc_type = _IOC_TYPE(cmd_op); |
1671 | |
1672 | if (!IS_ENABLED(CONFIG_BLKDEV_UBLK_LEGACY_OPCODES) && ioc_type != 'u') |
1673 | return -EOPNOTSUPP; |
1674 | |
1675 | if (ioc_type != 'u' && ioc_type != 0) |
1676 | return -EOPNOTSUPP; |
1677 | |
1678 | return 0; |
1679 | } |
1680 | |
1681 | static inline void ublk_fill_io_cmd(struct ublk_io *io, |
1682 | struct io_uring_cmd *cmd, unsigned long buf_addr) |
1683 | { |
1684 | io->cmd = cmd; |
1685 | io->flags |= UBLK_IO_FLAG_ACTIVE; |
1686 | io->addr = buf_addr; |
1687 | } |
1688 | |
1689 | static inline void ublk_prep_cancel(struct io_uring_cmd *cmd, |
1690 | unsigned int issue_flags, |
1691 | struct ublk_queue *ubq, unsigned int tag) |
1692 | { |
1693 | struct ublk_uring_cmd_pdu *pdu = ublk_get_uring_cmd_pdu(ioucmd: cmd); |
1694 | |
1695 | /* |
1696 | * Safe to refer to @ubq since ublk_queue won't be died until its |
1697 | * commands are completed |
1698 | */ |
1699 | pdu->ubq = ubq; |
1700 | pdu->tag = tag; |
1701 | io_uring_cmd_mark_cancelable(cmd, issue_flags); |
1702 | } |
1703 | |
1704 | static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd, |
1705 | unsigned int issue_flags, |
1706 | const struct ublksrv_io_cmd *ub_cmd) |
1707 | { |
1708 | struct ublk_device *ub = cmd->file->private_data; |
1709 | struct ublk_queue *ubq; |
1710 | struct ublk_io *io; |
1711 | u32 cmd_op = cmd->cmd_op; |
1712 | unsigned tag = ub_cmd->tag; |
1713 | int ret = -EINVAL; |
1714 | struct request *req; |
1715 | |
1716 | pr_devel("%s: received: cmd op %d queue %d tag %d result %d\n" , |
1717 | __func__, cmd->cmd_op, ub_cmd->q_id, tag, |
1718 | ub_cmd->result); |
1719 | |
1720 | if (ub_cmd->q_id >= ub->dev_info.nr_hw_queues) |
1721 | goto out; |
1722 | |
1723 | ubq = ublk_get_queue(dev: ub, qid: ub_cmd->q_id); |
1724 | if (!ubq || ub_cmd->q_id != ubq->q_id) |
1725 | goto out; |
1726 | |
1727 | if (ubq->ubq_daemon && ubq->ubq_daemon != current) |
1728 | goto out; |
1729 | |
1730 | if (tag >= ubq->q_depth) |
1731 | goto out; |
1732 | |
1733 | io = &ubq->ios[tag]; |
1734 | |
1735 | /* there is pending io cmd, something must be wrong */ |
1736 | if (io->flags & UBLK_IO_FLAG_ACTIVE) { |
1737 | ret = -EBUSY; |
1738 | goto out; |
1739 | } |
1740 | |
1741 | /* |
1742 | * ensure that the user issues UBLK_IO_NEED_GET_DATA |
1743 | * iff the driver have set the UBLK_IO_FLAG_NEED_GET_DATA. |
1744 | */ |
1745 | if ((!!(io->flags & UBLK_IO_FLAG_NEED_GET_DATA)) |
1746 | ^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA)) |
1747 | goto out; |
1748 | |
1749 | ret = ublk_check_cmd_op(cmd_op); |
1750 | if (ret) |
1751 | goto out; |
1752 | |
1753 | ret = -EINVAL; |
1754 | switch (_IOC_NR(cmd_op)) { |
1755 | case UBLK_IO_FETCH_REQ: |
1756 | /* UBLK_IO_FETCH_REQ is only allowed before queue is setup */ |
1757 | if (ublk_queue_ready(ubq)) { |
1758 | ret = -EBUSY; |
1759 | goto out; |
1760 | } |
1761 | /* |
1762 | * The io is being handled by server, so COMMIT_RQ is expected |
1763 | * instead of FETCH_REQ |
1764 | */ |
1765 | if (io->flags & UBLK_IO_FLAG_OWNED_BY_SRV) |
1766 | goto out; |
1767 | |
1768 | if (!ublk_support_user_copy(ubq)) { |
1769 | /* |
1770 | * FETCH_RQ has to provide IO buffer if NEED GET |
1771 | * DATA is not enabled |
1772 | */ |
1773 | if (!ub_cmd->addr && !ublk_need_get_data(ubq)) |
1774 | goto out; |
1775 | } else if (ub_cmd->addr) { |
1776 | /* User copy requires addr to be unset */ |
1777 | ret = -EINVAL; |
1778 | goto out; |
1779 | } |
1780 | |
1781 | ublk_fill_io_cmd(io, cmd, buf_addr: ub_cmd->addr); |
1782 | ublk_mark_io_ready(ub, ubq); |
1783 | break; |
1784 | case UBLK_IO_COMMIT_AND_FETCH_REQ: |
1785 | req = blk_mq_tag_to_rq(tags: ub->tag_set.tags[ub_cmd->q_id], tag); |
1786 | |
1787 | if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) |
1788 | goto out; |
1789 | |
1790 | if (!ublk_support_user_copy(ubq)) { |
1791 | /* |
1792 | * COMMIT_AND_FETCH_REQ has to provide IO buffer if |
1793 | * NEED GET DATA is not enabled or it is Read IO. |
1794 | */ |
1795 | if (!ub_cmd->addr && (!ublk_need_get_data(ubq) || |
1796 | req_op(req) == REQ_OP_READ)) |
1797 | goto out; |
1798 | } else if (req_op(req) != REQ_OP_ZONE_APPEND && ub_cmd->addr) { |
1799 | /* |
1800 | * User copy requires addr to be unset when command is |
1801 | * not zone append |
1802 | */ |
1803 | ret = -EINVAL; |
1804 | goto out; |
1805 | } |
1806 | |
1807 | ublk_fill_io_cmd(io, cmd, buf_addr: ub_cmd->addr); |
1808 | ublk_commit_completion(ub, ub_cmd); |
1809 | break; |
1810 | case UBLK_IO_NEED_GET_DATA: |
1811 | if (!(io->flags & UBLK_IO_FLAG_OWNED_BY_SRV)) |
1812 | goto out; |
1813 | ublk_fill_io_cmd(io, cmd, buf_addr: ub_cmd->addr); |
1814 | ublk_handle_need_get_data(ub, q_id: ub_cmd->q_id, tag: ub_cmd->tag); |
1815 | break; |
1816 | default: |
1817 | goto out; |
1818 | } |
1819 | ublk_prep_cancel(cmd, issue_flags, ubq, tag); |
1820 | return -EIOCBQUEUED; |
1821 | |
1822 | out: |
1823 | io_uring_cmd_done(cmd, ret, res2: 0, issue_flags); |
1824 | pr_devel("%s: complete: cmd op %d, tag %d ret %x io_flags %x\n" , |
1825 | __func__, cmd_op, tag, ret, io->flags); |
1826 | return -EIOCBQUEUED; |
1827 | } |
1828 | |
1829 | static inline struct request *__ublk_check_and_get_req(struct ublk_device *ub, |
1830 | struct ublk_queue *ubq, int tag, size_t offset) |
1831 | { |
1832 | struct request *req; |
1833 | |
1834 | if (!ublk_need_req_ref(ubq)) |
1835 | return NULL; |
1836 | |
1837 | req = blk_mq_tag_to_rq(tags: ub->tag_set.tags[ubq->q_id], tag); |
1838 | if (!req) |
1839 | return NULL; |
1840 | |
1841 | if (!ublk_get_req_ref(ubq, req)) |
1842 | return NULL; |
1843 | |
1844 | if (unlikely(!blk_mq_request_started(req) || req->tag != tag)) |
1845 | goto fail_put; |
1846 | |
1847 | if (!ublk_rq_has_data(rq: req)) |
1848 | goto fail_put; |
1849 | |
1850 | if (offset > blk_rq_bytes(rq: req)) |
1851 | goto fail_put; |
1852 | |
1853 | return req; |
1854 | fail_put: |
1855 | ublk_put_req_ref(ubq, req); |
1856 | return NULL; |
1857 | } |
1858 | |
1859 | static inline int ublk_ch_uring_cmd_local(struct io_uring_cmd *cmd, |
1860 | unsigned int issue_flags) |
1861 | { |
1862 | /* |
1863 | * Not necessary for async retry, but let's keep it simple and always |
1864 | * copy the values to avoid any potential reuse. |
1865 | */ |
1866 | const struct ublksrv_io_cmd *ub_src = io_uring_sqe_cmd(sqe: cmd->sqe); |
1867 | const struct ublksrv_io_cmd ub_cmd = { |
1868 | .q_id = READ_ONCE(ub_src->q_id), |
1869 | .tag = READ_ONCE(ub_src->tag), |
1870 | .result = READ_ONCE(ub_src->result), |
1871 | .addr = READ_ONCE(ub_src->addr) |
1872 | }; |
1873 | |
1874 | WARN_ON_ONCE(issue_flags & IO_URING_F_UNLOCKED); |
1875 | |
1876 | return __ublk_ch_uring_cmd(cmd, issue_flags, ub_cmd: &ub_cmd); |
1877 | } |
1878 | |
1879 | static void ublk_ch_uring_cmd_cb(struct io_uring_cmd *cmd, |
1880 | unsigned int issue_flags) |
1881 | { |
1882 | ublk_ch_uring_cmd_local(cmd, issue_flags); |
1883 | } |
1884 | |
1885 | static int ublk_ch_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags) |
1886 | { |
1887 | if (unlikely(issue_flags & IO_URING_F_CANCEL)) { |
1888 | ublk_uring_cmd_cancel_fn(cmd, issue_flags); |
1889 | return 0; |
1890 | } |
1891 | |
1892 | /* well-implemented server won't run into unlocked */ |
1893 | if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) { |
1894 | io_uring_cmd_complete_in_task(ioucmd: cmd, task_work_cb: ublk_ch_uring_cmd_cb); |
1895 | return -EIOCBQUEUED; |
1896 | } |
1897 | |
1898 | return ublk_ch_uring_cmd_local(cmd, issue_flags); |
1899 | } |
1900 | |
1901 | static inline bool ublk_check_ubuf_dir(const struct request *req, |
1902 | int ubuf_dir) |
1903 | { |
1904 | /* copy ubuf to request pages */ |
1905 | if ((req_op(req) == REQ_OP_READ || req_op(req) == REQ_OP_DRV_IN) && |
1906 | ubuf_dir == ITER_SOURCE) |
1907 | return true; |
1908 | |
1909 | /* copy request pages to ubuf */ |
1910 | if ((req_op(req) == REQ_OP_WRITE || |
1911 | req_op(req) == REQ_OP_ZONE_APPEND) && |
1912 | ubuf_dir == ITER_DEST) |
1913 | return true; |
1914 | |
1915 | return false; |
1916 | } |
1917 | |
1918 | static struct request *ublk_check_and_get_req(struct kiocb *iocb, |
1919 | struct iov_iter *iter, size_t *off, int dir) |
1920 | { |
1921 | struct ublk_device *ub = iocb->ki_filp->private_data; |
1922 | struct ublk_queue *ubq; |
1923 | struct request *req; |
1924 | size_t buf_off; |
1925 | u16 tag, q_id; |
1926 | |
1927 | if (!ub) |
1928 | return ERR_PTR(error: -EACCES); |
1929 | |
1930 | if (!user_backed_iter(i: iter)) |
1931 | return ERR_PTR(error: -EACCES); |
1932 | |
1933 | if (ub->dev_info.state == UBLK_S_DEV_DEAD) |
1934 | return ERR_PTR(error: -EACCES); |
1935 | |
1936 | tag = ublk_pos_to_tag(pos: iocb->ki_pos); |
1937 | q_id = ublk_pos_to_hwq(pos: iocb->ki_pos); |
1938 | buf_off = ublk_pos_to_buf_off(pos: iocb->ki_pos); |
1939 | |
1940 | if (q_id >= ub->dev_info.nr_hw_queues) |
1941 | return ERR_PTR(error: -EINVAL); |
1942 | |
1943 | ubq = ublk_get_queue(dev: ub, qid: q_id); |
1944 | if (!ubq) |
1945 | return ERR_PTR(error: -EINVAL); |
1946 | |
1947 | if (tag >= ubq->q_depth) |
1948 | return ERR_PTR(error: -EINVAL); |
1949 | |
1950 | req = __ublk_check_and_get_req(ub, ubq, tag, offset: buf_off); |
1951 | if (!req) |
1952 | return ERR_PTR(error: -EINVAL); |
1953 | |
1954 | if (!req->mq_hctx || !req->mq_hctx->driver_data) |
1955 | goto fail; |
1956 | |
1957 | if (!ublk_check_ubuf_dir(req, ubuf_dir: dir)) |
1958 | goto fail; |
1959 | |
1960 | *off = buf_off; |
1961 | return req; |
1962 | fail: |
1963 | ublk_put_req_ref(ubq, req); |
1964 | return ERR_PTR(error: -EACCES); |
1965 | } |
1966 | |
1967 | static ssize_t ublk_ch_read_iter(struct kiocb *iocb, struct iov_iter *to) |
1968 | { |
1969 | struct ublk_queue *ubq; |
1970 | struct request *req; |
1971 | size_t buf_off; |
1972 | size_t ret; |
1973 | |
1974 | req = ublk_check_and_get_req(iocb, iter: to, off: &buf_off, ITER_DEST); |
1975 | if (IS_ERR(ptr: req)) |
1976 | return PTR_ERR(ptr: req); |
1977 | |
1978 | ret = ublk_copy_user_pages(req, offset: buf_off, uiter: to, ITER_DEST); |
1979 | ubq = req->mq_hctx->driver_data; |
1980 | ublk_put_req_ref(ubq, req); |
1981 | |
1982 | return ret; |
1983 | } |
1984 | |
1985 | static ssize_t ublk_ch_write_iter(struct kiocb *iocb, struct iov_iter *from) |
1986 | { |
1987 | struct ublk_queue *ubq; |
1988 | struct request *req; |
1989 | size_t buf_off; |
1990 | size_t ret; |
1991 | |
1992 | req = ublk_check_and_get_req(iocb, iter: from, off: &buf_off, ITER_SOURCE); |
1993 | if (IS_ERR(ptr: req)) |
1994 | return PTR_ERR(ptr: req); |
1995 | |
1996 | ret = ublk_copy_user_pages(req, offset: buf_off, uiter: from, ITER_SOURCE); |
1997 | ubq = req->mq_hctx->driver_data; |
1998 | ublk_put_req_ref(ubq, req); |
1999 | |
2000 | return ret; |
2001 | } |
2002 | |
2003 | static const struct file_operations ublk_ch_fops = { |
2004 | .owner = THIS_MODULE, |
2005 | .open = ublk_ch_open, |
2006 | .release = ublk_ch_release, |
2007 | .llseek = no_llseek, |
2008 | .read_iter = ublk_ch_read_iter, |
2009 | .write_iter = ublk_ch_write_iter, |
2010 | .uring_cmd = ublk_ch_uring_cmd, |
2011 | .mmap = ublk_ch_mmap, |
2012 | }; |
2013 | |
2014 | static void ublk_deinit_queue(struct ublk_device *ub, int q_id) |
2015 | { |
2016 | int size = ublk_queue_cmd_buf_size(ub, q_id); |
2017 | struct ublk_queue *ubq = ublk_get_queue(dev: ub, qid: q_id); |
2018 | |
2019 | if (ubq->ubq_daemon) |
2020 | put_task_struct(t: ubq->ubq_daemon); |
2021 | if (ubq->io_cmd_buf) |
2022 | free_pages(addr: (unsigned long)ubq->io_cmd_buf, order: get_order(size)); |
2023 | } |
2024 | |
2025 | static int ublk_init_queue(struct ublk_device *ub, int q_id) |
2026 | { |
2027 | struct ublk_queue *ubq = ublk_get_queue(dev: ub, qid: q_id); |
2028 | gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO; |
2029 | void *ptr; |
2030 | int size; |
2031 | |
2032 | spin_lock_init(&ubq->cancel_lock); |
2033 | ubq->flags = ub->dev_info.flags; |
2034 | ubq->q_id = q_id; |
2035 | ubq->q_depth = ub->dev_info.queue_depth; |
2036 | size = ublk_queue_cmd_buf_size(ub, q_id); |
2037 | |
2038 | ptr = (void *) __get_free_pages(gfp_mask: gfp_flags, order: get_order(size)); |
2039 | if (!ptr) |
2040 | return -ENOMEM; |
2041 | |
2042 | ubq->io_cmd_buf = ptr; |
2043 | ubq->dev = ub; |
2044 | return 0; |
2045 | } |
2046 | |
2047 | static void ublk_deinit_queues(struct ublk_device *ub) |
2048 | { |
2049 | int nr_queues = ub->dev_info.nr_hw_queues; |
2050 | int i; |
2051 | |
2052 | if (!ub->__queues) |
2053 | return; |
2054 | |
2055 | for (i = 0; i < nr_queues; i++) |
2056 | ublk_deinit_queue(ub, q_id: i); |
2057 | kfree(objp: ub->__queues); |
2058 | } |
2059 | |
2060 | static int ublk_init_queues(struct ublk_device *ub) |
2061 | { |
2062 | int nr_queues = ub->dev_info.nr_hw_queues; |
2063 | int depth = ub->dev_info.queue_depth; |
2064 | int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io); |
2065 | int i, ret = -ENOMEM; |
2066 | |
2067 | ub->queue_size = ubq_size; |
2068 | ub->__queues = kcalloc(n: nr_queues, size: ubq_size, GFP_KERNEL); |
2069 | if (!ub->__queues) |
2070 | return ret; |
2071 | |
2072 | for (i = 0; i < nr_queues; i++) { |
2073 | if (ublk_init_queue(ub, q_id: i)) |
2074 | goto fail; |
2075 | } |
2076 | |
2077 | init_completion(x: &ub->completion); |
2078 | return 0; |
2079 | |
2080 | fail: |
2081 | ublk_deinit_queues(ub); |
2082 | return ret; |
2083 | } |
2084 | |
2085 | static int ublk_alloc_dev_number(struct ublk_device *ub, int idx) |
2086 | { |
2087 | int i = idx; |
2088 | int err; |
2089 | |
2090 | spin_lock(lock: &ublk_idr_lock); |
2091 | /* allocate id, if @id >= 0, we're requesting that specific id */ |
2092 | if (i >= 0) { |
2093 | err = idr_alloc(&ublk_index_idr, ptr: ub, start: i, end: i + 1, GFP_NOWAIT); |
2094 | if (err == -ENOSPC) |
2095 | err = -EEXIST; |
2096 | } else { |
2097 | err = idr_alloc(&ublk_index_idr, ptr: ub, start: 0, UBLK_MAX_UBLKS, |
2098 | GFP_NOWAIT); |
2099 | } |
2100 | spin_unlock(lock: &ublk_idr_lock); |
2101 | |
2102 | if (err >= 0) |
2103 | ub->ub_number = err; |
2104 | |
2105 | return err; |
2106 | } |
2107 | |
2108 | static void ublk_free_dev_number(struct ublk_device *ub) |
2109 | { |
2110 | spin_lock(lock: &ublk_idr_lock); |
2111 | idr_remove(&ublk_index_idr, id: ub->ub_number); |
2112 | wake_up_all(&ublk_idr_wq); |
2113 | spin_unlock(lock: &ublk_idr_lock); |
2114 | } |
2115 | |
2116 | static void ublk_cdev_rel(struct device *dev) |
2117 | { |
2118 | struct ublk_device *ub = container_of(dev, struct ublk_device, cdev_dev); |
2119 | |
2120 | blk_mq_free_tag_set(set: &ub->tag_set); |
2121 | ublk_deinit_queues(ub); |
2122 | ublk_free_dev_number(ub); |
2123 | mutex_destroy(lock: &ub->mutex); |
2124 | kfree(objp: ub); |
2125 | } |
2126 | |
2127 | static int ublk_add_chdev(struct ublk_device *ub) |
2128 | { |
2129 | struct device *dev = &ub->cdev_dev; |
2130 | int minor = ub->ub_number; |
2131 | int ret; |
2132 | |
2133 | dev->parent = ublk_misc.this_device; |
2134 | dev->devt = MKDEV(MAJOR(ublk_chr_devt), minor); |
2135 | dev->class = &ublk_chr_class; |
2136 | dev->release = ublk_cdev_rel; |
2137 | device_initialize(dev); |
2138 | |
2139 | ret = dev_set_name(dev, name: "ublkc%d" , minor); |
2140 | if (ret) |
2141 | goto fail; |
2142 | |
2143 | cdev_init(&ub->cdev, &ublk_ch_fops); |
2144 | ret = cdev_device_add(cdev: &ub->cdev, dev); |
2145 | if (ret) |
2146 | goto fail; |
2147 | |
2148 | ublks_added++; |
2149 | return 0; |
2150 | fail: |
2151 | put_device(dev); |
2152 | return ret; |
2153 | } |
2154 | |
2155 | static void ublk_stop_work_fn(struct work_struct *work) |
2156 | { |
2157 | struct ublk_device *ub = |
2158 | container_of(work, struct ublk_device, stop_work); |
2159 | |
2160 | ublk_stop_dev(ub); |
2161 | } |
2162 | |
2163 | /* align max io buffer size with PAGE_SIZE */ |
2164 | static void ublk_align_max_io_size(struct ublk_device *ub) |
2165 | { |
2166 | unsigned int max_io_bytes = ub->dev_info.max_io_buf_bytes; |
2167 | |
2168 | ub->dev_info.max_io_buf_bytes = |
2169 | round_down(max_io_bytes, PAGE_SIZE); |
2170 | } |
2171 | |
2172 | static int ublk_add_tag_set(struct ublk_device *ub) |
2173 | { |
2174 | ub->tag_set.ops = &ublk_mq_ops; |
2175 | ub->tag_set.nr_hw_queues = ub->dev_info.nr_hw_queues; |
2176 | ub->tag_set.queue_depth = ub->dev_info.queue_depth; |
2177 | ub->tag_set.numa_node = NUMA_NO_NODE; |
2178 | ub->tag_set.cmd_size = sizeof(struct ublk_rq_data); |
2179 | ub->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; |
2180 | ub->tag_set.driver_data = ub; |
2181 | return blk_mq_alloc_tag_set(set: &ub->tag_set); |
2182 | } |
2183 | |
2184 | static void ublk_remove(struct ublk_device *ub) |
2185 | { |
2186 | ublk_stop_dev(ub); |
2187 | cancel_work_sync(work: &ub->stop_work); |
2188 | cancel_work_sync(work: &ub->quiesce_work); |
2189 | cdev_device_del(cdev: &ub->cdev, dev: &ub->cdev_dev); |
2190 | put_device(dev: &ub->cdev_dev); |
2191 | ublks_added--; |
2192 | } |
2193 | |
2194 | static struct ublk_device *ublk_get_device_from_id(int idx) |
2195 | { |
2196 | struct ublk_device *ub = NULL; |
2197 | |
2198 | if (idx < 0) |
2199 | return NULL; |
2200 | |
2201 | spin_lock(lock: &ublk_idr_lock); |
2202 | ub = idr_find(&ublk_index_idr, id: idx); |
2203 | if (ub) |
2204 | ub = ublk_get_device(ub); |
2205 | spin_unlock(lock: &ublk_idr_lock); |
2206 | |
2207 | return ub; |
2208 | } |
2209 | |
2210 | static int ublk_ctrl_start_dev(struct ublk_device *ub, struct io_uring_cmd *cmd) |
2211 | { |
2212 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2213 | int ublksrv_pid = (int)header->data[0]; |
2214 | struct gendisk *disk; |
2215 | int ret = -EINVAL; |
2216 | |
2217 | if (ublksrv_pid <= 0) |
2218 | return -EINVAL; |
2219 | |
2220 | if (wait_for_completion_interruptible(x: &ub->completion) != 0) |
2221 | return -EINTR; |
2222 | |
2223 | mutex_lock(&ub->mutex); |
2224 | if (ub->dev_info.state == UBLK_S_DEV_LIVE || |
2225 | test_bit(UB_STATE_USED, &ub->state)) { |
2226 | ret = -EEXIST; |
2227 | goto out_unlock; |
2228 | } |
2229 | |
2230 | disk = blk_mq_alloc_disk(&ub->tag_set, NULL); |
2231 | if (IS_ERR(ptr: disk)) { |
2232 | ret = PTR_ERR(ptr: disk); |
2233 | goto out_unlock; |
2234 | } |
2235 | sprintf(buf: disk->disk_name, fmt: "ublkb%d" , ub->ub_number); |
2236 | disk->fops = &ub_fops; |
2237 | disk->private_data = ub; |
2238 | |
2239 | ub->dev_info.ublksrv_pid = ublksrv_pid; |
2240 | ub->ub_disk = disk; |
2241 | |
2242 | ret = ublk_apply_params(ub); |
2243 | if (ret) |
2244 | goto out_put_disk; |
2245 | |
2246 | /* don't probe partitions if any one ubq daemon is un-trusted */ |
2247 | if (ub->nr_privileged_daemon != ub->nr_queues_ready) |
2248 | set_bit(GD_SUPPRESS_PART_SCAN, addr: &disk->state); |
2249 | |
2250 | get_device(dev: &ub->cdev_dev); |
2251 | ub->dev_info.state = UBLK_S_DEV_LIVE; |
2252 | |
2253 | if (ublk_dev_is_zoned(ub)) { |
2254 | ret = ublk_revalidate_disk_zones(ub); |
2255 | if (ret) |
2256 | goto out_put_cdev; |
2257 | } |
2258 | |
2259 | ret = add_disk(disk); |
2260 | if (ret) |
2261 | goto out_put_cdev; |
2262 | |
2263 | set_bit(UB_STATE_USED, addr: &ub->state); |
2264 | |
2265 | out_put_cdev: |
2266 | if (ret) { |
2267 | ub->dev_info.state = UBLK_S_DEV_DEAD; |
2268 | ublk_put_device(ub); |
2269 | } |
2270 | out_put_disk: |
2271 | if (ret) |
2272 | put_disk(disk); |
2273 | out_unlock: |
2274 | mutex_unlock(lock: &ub->mutex); |
2275 | return ret; |
2276 | } |
2277 | |
2278 | static int ublk_ctrl_get_queue_affinity(struct ublk_device *ub, |
2279 | struct io_uring_cmd *cmd) |
2280 | { |
2281 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2282 | void __user *argp = (void __user *)(unsigned long)header->addr; |
2283 | cpumask_var_t cpumask; |
2284 | unsigned long queue; |
2285 | unsigned int retlen; |
2286 | unsigned int i; |
2287 | int ret; |
2288 | |
2289 | if (header->len * BITS_PER_BYTE < nr_cpu_ids) |
2290 | return -EINVAL; |
2291 | if (header->len & (sizeof(unsigned long)-1)) |
2292 | return -EINVAL; |
2293 | if (!header->addr) |
2294 | return -EINVAL; |
2295 | |
2296 | queue = header->data[0]; |
2297 | if (queue >= ub->dev_info.nr_hw_queues) |
2298 | return -EINVAL; |
2299 | |
2300 | if (!zalloc_cpumask_var(mask: &cpumask, GFP_KERNEL)) |
2301 | return -ENOMEM; |
2302 | |
2303 | for_each_possible_cpu(i) { |
2304 | if (ub->tag_set.map[HCTX_TYPE_DEFAULT].mq_map[i] == queue) |
2305 | cpumask_set_cpu(cpu: i, dstp: cpumask); |
2306 | } |
2307 | |
2308 | ret = -EFAULT; |
2309 | retlen = min_t(unsigned short, header->len, cpumask_size()); |
2310 | if (copy_to_user(to: argp, from: cpumask, n: retlen)) |
2311 | goto out_free_cpumask; |
2312 | if (retlen != header->len && |
2313 | clear_user(to: argp + retlen, n: header->len - retlen)) |
2314 | goto out_free_cpumask; |
2315 | |
2316 | ret = 0; |
2317 | out_free_cpumask: |
2318 | free_cpumask_var(mask: cpumask); |
2319 | return ret; |
2320 | } |
2321 | |
2322 | static inline void ublk_dump_dev_info(struct ublksrv_ctrl_dev_info *info) |
2323 | { |
2324 | pr_devel("%s: dev id %d flags %llx\n" , __func__, |
2325 | info->dev_id, info->flags); |
2326 | pr_devel("\t nr_hw_queues %d queue_depth %d\n" , |
2327 | info->nr_hw_queues, info->queue_depth); |
2328 | } |
2329 | |
2330 | static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) |
2331 | { |
2332 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2333 | void __user *argp = (void __user *)(unsigned long)header->addr; |
2334 | struct ublksrv_ctrl_dev_info info; |
2335 | struct ublk_device *ub; |
2336 | int ret = -EINVAL; |
2337 | |
2338 | if (header->len < sizeof(info) || !header->addr) |
2339 | return -EINVAL; |
2340 | if (header->queue_id != (u16)-1) { |
2341 | pr_warn("%s: queue_id is wrong %x\n" , |
2342 | __func__, header->queue_id); |
2343 | return -EINVAL; |
2344 | } |
2345 | |
2346 | if (copy_from_user(to: &info, from: argp, n: sizeof(info))) |
2347 | return -EFAULT; |
2348 | |
2349 | if (capable(CAP_SYS_ADMIN)) |
2350 | info.flags &= ~UBLK_F_UNPRIVILEGED_DEV; |
2351 | else if (!(info.flags & UBLK_F_UNPRIVILEGED_DEV)) |
2352 | return -EPERM; |
2353 | |
2354 | /* |
2355 | * unprivileged device can't be trusted, but RECOVERY and |
2356 | * RECOVERY_REISSUE still may hang error handling, so can't |
2357 | * support recovery features for unprivileged ublk now |
2358 | * |
2359 | * TODO: provide forward progress for RECOVERY handler, so that |
2360 | * unprivileged device can benefit from it |
2361 | */ |
2362 | if (info.flags & UBLK_F_UNPRIVILEGED_DEV) |
2363 | info.flags &= ~(UBLK_F_USER_RECOVERY_REISSUE | |
2364 | UBLK_F_USER_RECOVERY); |
2365 | |
2366 | /* the created device is always owned by current user */ |
2367 | ublk_store_owner_uid_gid(owner_uid: &info.owner_uid, owner_gid: &info.owner_gid); |
2368 | |
2369 | if (header->dev_id != info.dev_id) { |
2370 | pr_warn("%s: dev id not match %u %u\n" , |
2371 | __func__, header->dev_id, info.dev_id); |
2372 | return -EINVAL; |
2373 | } |
2374 | |
2375 | if (header->dev_id != U32_MAX && header->dev_id >= UBLK_MAX_UBLKS) { |
2376 | pr_warn("%s: dev id is too large. Max supported is %d\n" , |
2377 | __func__, UBLK_MAX_UBLKS - 1); |
2378 | return -EINVAL; |
2379 | } |
2380 | |
2381 | ublk_dump_dev_info(info: &info); |
2382 | |
2383 | ret = mutex_lock_killable(&ublk_ctl_mutex); |
2384 | if (ret) |
2385 | return ret; |
2386 | |
2387 | ret = -EACCES; |
2388 | if (ublks_added >= ublks_max) |
2389 | goto out_unlock; |
2390 | |
2391 | ret = -ENOMEM; |
2392 | ub = kzalloc(size: sizeof(*ub), GFP_KERNEL); |
2393 | if (!ub) |
2394 | goto out_unlock; |
2395 | mutex_init(&ub->mutex); |
2396 | spin_lock_init(&ub->lock); |
2397 | INIT_WORK(&ub->quiesce_work, ublk_quiesce_work_fn); |
2398 | INIT_WORK(&ub->stop_work, ublk_stop_work_fn); |
2399 | |
2400 | ret = ublk_alloc_dev_number(ub, idx: header->dev_id); |
2401 | if (ret < 0) |
2402 | goto out_free_ub; |
2403 | |
2404 | memcpy(&ub->dev_info, &info, sizeof(info)); |
2405 | |
2406 | /* update device id */ |
2407 | ub->dev_info.dev_id = ub->ub_number; |
2408 | |
2409 | /* |
2410 | * 64bit flags will be copied back to userspace as feature |
2411 | * negotiation result, so have to clear flags which driver |
2412 | * doesn't support yet, then userspace can get correct flags |
2413 | * (features) to handle. |
2414 | */ |
2415 | ub->dev_info.flags &= UBLK_F_ALL; |
2416 | |
2417 | ub->dev_info.flags |= UBLK_F_CMD_IOCTL_ENCODE | |
2418 | UBLK_F_URING_CMD_COMP_IN_TASK; |
2419 | |
2420 | /* GET_DATA isn't needed any more with USER_COPY */ |
2421 | if (ublk_dev_is_user_copy(ub)) |
2422 | ub->dev_info.flags &= ~UBLK_F_NEED_GET_DATA; |
2423 | |
2424 | /* Zoned storage support requires user copy feature */ |
2425 | if (ublk_dev_is_zoned(ub) && |
2426 | (!IS_ENABLED(CONFIG_BLK_DEV_ZONED) || !ublk_dev_is_user_copy(ub))) { |
2427 | ret = -EINVAL; |
2428 | goto out_free_dev_number; |
2429 | } |
2430 | |
2431 | /* We are not ready to support zero copy */ |
2432 | ub->dev_info.flags &= ~UBLK_F_SUPPORT_ZERO_COPY; |
2433 | |
2434 | ub->dev_info.nr_hw_queues = min_t(unsigned int, |
2435 | ub->dev_info.nr_hw_queues, nr_cpu_ids); |
2436 | ublk_align_max_io_size(ub); |
2437 | |
2438 | ret = ublk_init_queues(ub); |
2439 | if (ret) |
2440 | goto out_free_dev_number; |
2441 | |
2442 | ret = ublk_add_tag_set(ub); |
2443 | if (ret) |
2444 | goto out_deinit_queues; |
2445 | |
2446 | ret = -EFAULT; |
2447 | if (copy_to_user(to: argp, from: &ub->dev_info, n: sizeof(info))) |
2448 | goto out_free_tag_set; |
2449 | |
2450 | /* |
2451 | * Add the char dev so that ublksrv daemon can be setup. |
2452 | * ublk_add_chdev() will cleanup everything if it fails. |
2453 | */ |
2454 | ret = ublk_add_chdev(ub); |
2455 | goto out_unlock; |
2456 | |
2457 | out_free_tag_set: |
2458 | blk_mq_free_tag_set(set: &ub->tag_set); |
2459 | out_deinit_queues: |
2460 | ublk_deinit_queues(ub); |
2461 | out_free_dev_number: |
2462 | ublk_free_dev_number(ub); |
2463 | out_free_ub: |
2464 | mutex_destroy(lock: &ub->mutex); |
2465 | kfree(objp: ub); |
2466 | out_unlock: |
2467 | mutex_unlock(lock: &ublk_ctl_mutex); |
2468 | return ret; |
2469 | } |
2470 | |
2471 | static inline bool ublk_idr_freed(int id) |
2472 | { |
2473 | void *ptr; |
2474 | |
2475 | spin_lock(lock: &ublk_idr_lock); |
2476 | ptr = idr_find(&ublk_index_idr, id); |
2477 | spin_unlock(lock: &ublk_idr_lock); |
2478 | |
2479 | return ptr == NULL; |
2480 | } |
2481 | |
2482 | static int ublk_ctrl_del_dev(struct ublk_device **p_ub) |
2483 | { |
2484 | struct ublk_device *ub = *p_ub; |
2485 | int idx = ub->ub_number; |
2486 | int ret; |
2487 | |
2488 | ret = mutex_lock_killable(&ublk_ctl_mutex); |
2489 | if (ret) |
2490 | return ret; |
2491 | |
2492 | if (!test_bit(UB_STATE_DELETED, &ub->state)) { |
2493 | ublk_remove(ub); |
2494 | set_bit(UB_STATE_DELETED, addr: &ub->state); |
2495 | } |
2496 | |
2497 | /* Mark the reference as consumed */ |
2498 | *p_ub = NULL; |
2499 | ublk_put_device(ub); |
2500 | mutex_unlock(lock: &ublk_ctl_mutex); |
2501 | |
2502 | /* |
2503 | * Wait until the idr is removed, then it can be reused after |
2504 | * DEL_DEV command is returned. |
2505 | * |
2506 | * If we returns because of user interrupt, future delete command |
2507 | * may come: |
2508 | * |
2509 | * - the device number isn't freed, this device won't or needn't |
2510 | * be deleted again, since UB_STATE_DELETED is set, and device |
2511 | * will be released after the last reference is dropped |
2512 | * |
2513 | * - the device number is freed already, we will not find this |
2514 | * device via ublk_get_device_from_id() |
2515 | */ |
2516 | if (wait_event_interruptible(ublk_idr_wq, ublk_idr_freed(idx))) |
2517 | return -EINTR; |
2518 | return 0; |
2519 | } |
2520 | |
2521 | static inline void ublk_ctrl_cmd_dump(struct io_uring_cmd *cmd) |
2522 | { |
2523 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2524 | |
2525 | pr_devel("%s: cmd_op %x, dev id %d qid %d data %llx buf %llx len %u\n" , |
2526 | __func__, cmd->cmd_op, header->dev_id, header->queue_id, |
2527 | header->data[0], header->addr, header->len); |
2528 | } |
2529 | |
2530 | static int ublk_ctrl_stop_dev(struct ublk_device *ub) |
2531 | { |
2532 | ublk_stop_dev(ub); |
2533 | cancel_work_sync(work: &ub->stop_work); |
2534 | cancel_work_sync(work: &ub->quiesce_work); |
2535 | |
2536 | return 0; |
2537 | } |
2538 | |
2539 | static int ublk_ctrl_get_dev_info(struct ublk_device *ub, |
2540 | struct io_uring_cmd *cmd) |
2541 | { |
2542 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2543 | void __user *argp = (void __user *)(unsigned long)header->addr; |
2544 | |
2545 | if (header->len < sizeof(struct ublksrv_ctrl_dev_info) || !header->addr) |
2546 | return -EINVAL; |
2547 | |
2548 | if (copy_to_user(to: argp, from: &ub->dev_info, n: sizeof(ub->dev_info))) |
2549 | return -EFAULT; |
2550 | |
2551 | return 0; |
2552 | } |
2553 | |
2554 | /* TYPE_DEVT is readonly, so fill it up before returning to userspace */ |
2555 | static void ublk_ctrl_fill_params_devt(struct ublk_device *ub) |
2556 | { |
2557 | ub->params.devt.char_major = MAJOR(ub->cdev_dev.devt); |
2558 | ub->params.devt.char_minor = MINOR(ub->cdev_dev.devt); |
2559 | |
2560 | if (ub->ub_disk) { |
2561 | ub->params.devt.disk_major = MAJOR(disk_devt(ub->ub_disk)); |
2562 | ub->params.devt.disk_minor = MINOR(disk_devt(ub->ub_disk)); |
2563 | } else { |
2564 | ub->params.devt.disk_major = 0; |
2565 | ub->params.devt.disk_minor = 0; |
2566 | } |
2567 | ub->params.types |= UBLK_PARAM_TYPE_DEVT; |
2568 | } |
2569 | |
2570 | static int ublk_ctrl_get_params(struct ublk_device *ub, |
2571 | struct io_uring_cmd *cmd) |
2572 | { |
2573 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2574 | void __user *argp = (void __user *)(unsigned long)header->addr; |
2575 | struct ublk_params_header ph; |
2576 | int ret; |
2577 | |
2578 | if (header->len <= sizeof(ph) || !header->addr) |
2579 | return -EINVAL; |
2580 | |
2581 | if (copy_from_user(to: &ph, from: argp, n: sizeof(ph))) |
2582 | return -EFAULT; |
2583 | |
2584 | if (ph.len > header->len || !ph.len) |
2585 | return -EINVAL; |
2586 | |
2587 | if (ph.len > sizeof(struct ublk_params)) |
2588 | ph.len = sizeof(struct ublk_params); |
2589 | |
2590 | mutex_lock(&ub->mutex); |
2591 | ublk_ctrl_fill_params_devt(ub); |
2592 | if (copy_to_user(to: argp, from: &ub->params, n: ph.len)) |
2593 | ret = -EFAULT; |
2594 | else |
2595 | ret = 0; |
2596 | mutex_unlock(lock: &ub->mutex); |
2597 | |
2598 | return ret; |
2599 | } |
2600 | |
2601 | static int ublk_ctrl_set_params(struct ublk_device *ub, |
2602 | struct io_uring_cmd *cmd) |
2603 | { |
2604 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2605 | void __user *argp = (void __user *)(unsigned long)header->addr; |
2606 | struct ublk_params_header ph; |
2607 | int ret = -EFAULT; |
2608 | |
2609 | if (header->len <= sizeof(ph) || !header->addr) |
2610 | return -EINVAL; |
2611 | |
2612 | if (copy_from_user(to: &ph, from: argp, n: sizeof(ph))) |
2613 | return -EFAULT; |
2614 | |
2615 | if (ph.len > header->len || !ph.len || !ph.types) |
2616 | return -EINVAL; |
2617 | |
2618 | if (ph.len > sizeof(struct ublk_params)) |
2619 | ph.len = sizeof(struct ublk_params); |
2620 | |
2621 | /* parameters can only be changed when device isn't live */ |
2622 | mutex_lock(&ub->mutex); |
2623 | if (ub->dev_info.state == UBLK_S_DEV_LIVE) { |
2624 | ret = -EACCES; |
2625 | } else if (copy_from_user(to: &ub->params, from: argp, n: ph.len)) { |
2626 | ret = -EFAULT; |
2627 | } else { |
2628 | /* clear all we don't support yet */ |
2629 | ub->params.types &= UBLK_PARAM_TYPE_ALL; |
2630 | ret = ublk_validate_params(ub); |
2631 | if (ret) |
2632 | ub->params.types = 0; |
2633 | } |
2634 | mutex_unlock(lock: &ub->mutex); |
2635 | |
2636 | return ret; |
2637 | } |
2638 | |
2639 | static void ublk_queue_reinit(struct ublk_device *ub, struct ublk_queue *ubq) |
2640 | { |
2641 | int i; |
2642 | |
2643 | WARN_ON_ONCE(!(ubq->ubq_daemon && ubq_daemon_is_dying(ubq))); |
2644 | |
2645 | /* All old ioucmds have to be completed */ |
2646 | ubq->nr_io_ready = 0; |
2647 | /* old daemon is PF_EXITING, put it now */ |
2648 | put_task_struct(t: ubq->ubq_daemon); |
2649 | /* We have to reset it to NULL, otherwise ub won't accept new FETCH_REQ */ |
2650 | ubq->ubq_daemon = NULL; |
2651 | ubq->timeout = false; |
2652 | ubq->canceling = false; |
2653 | |
2654 | for (i = 0; i < ubq->q_depth; i++) { |
2655 | struct ublk_io *io = &ubq->ios[i]; |
2656 | |
2657 | /* forget everything now and be ready for new FETCH_REQ */ |
2658 | io->flags = 0; |
2659 | io->cmd = NULL; |
2660 | io->addr = 0; |
2661 | } |
2662 | } |
2663 | |
2664 | static int ublk_ctrl_start_recovery(struct ublk_device *ub, |
2665 | struct io_uring_cmd *cmd) |
2666 | { |
2667 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2668 | int ret = -EINVAL; |
2669 | int i; |
2670 | |
2671 | mutex_lock(&ub->mutex); |
2672 | if (!ublk_can_use_recovery(ub)) |
2673 | goto out_unlock; |
2674 | /* |
2675 | * START_RECOVERY is only allowd after: |
2676 | * |
2677 | * (1) UB_STATE_OPEN is not set, which means the dying process is exited |
2678 | * and related io_uring ctx is freed so file struct of /dev/ublkcX is |
2679 | * released. |
2680 | * |
2681 | * (2) UBLK_S_DEV_QUIESCED is set, which means the quiesce_work: |
2682 | * (a)has quiesced request queue |
2683 | * (b)has requeued every inflight rqs whose io_flags is ACTIVE |
2684 | * (c)has requeued/aborted every inflight rqs whose io_flags is NOT ACTIVE |
2685 | * (d)has completed/camceled all ioucmds owned by ther dying process |
2686 | */ |
2687 | if (test_bit(UB_STATE_OPEN, &ub->state) || |
2688 | ub->dev_info.state != UBLK_S_DEV_QUIESCED) { |
2689 | ret = -EBUSY; |
2690 | goto out_unlock; |
2691 | } |
2692 | pr_devel("%s: start recovery for dev id %d.\n" , __func__, header->dev_id); |
2693 | for (i = 0; i < ub->dev_info.nr_hw_queues; i++) |
2694 | ublk_queue_reinit(ub, ubq: ublk_get_queue(dev: ub, qid: i)); |
2695 | /* set to NULL, otherwise new ubq_daemon cannot mmap the io_cmd_buf */ |
2696 | ub->mm = NULL; |
2697 | ub->nr_queues_ready = 0; |
2698 | ub->nr_privileged_daemon = 0; |
2699 | init_completion(x: &ub->completion); |
2700 | ret = 0; |
2701 | out_unlock: |
2702 | mutex_unlock(lock: &ub->mutex); |
2703 | return ret; |
2704 | } |
2705 | |
2706 | static int ublk_ctrl_end_recovery(struct ublk_device *ub, |
2707 | struct io_uring_cmd *cmd) |
2708 | { |
2709 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2710 | int ublksrv_pid = (int)header->data[0]; |
2711 | int ret = -EINVAL; |
2712 | |
2713 | pr_devel("%s: Waiting for new ubq_daemons(nr: %d) are ready, dev id %d...\n" , |
2714 | __func__, ub->dev_info.nr_hw_queues, header->dev_id); |
2715 | /* wait until new ubq_daemon sending all FETCH_REQ */ |
2716 | if (wait_for_completion_interruptible(x: &ub->completion)) |
2717 | return -EINTR; |
2718 | |
2719 | pr_devel("%s: All new ubq_daemons(nr: %d) are ready, dev id %d\n" , |
2720 | __func__, ub->dev_info.nr_hw_queues, header->dev_id); |
2721 | |
2722 | mutex_lock(&ub->mutex); |
2723 | if (!ublk_can_use_recovery(ub)) |
2724 | goto out_unlock; |
2725 | |
2726 | if (ub->dev_info.state != UBLK_S_DEV_QUIESCED) { |
2727 | ret = -EBUSY; |
2728 | goto out_unlock; |
2729 | } |
2730 | ub->dev_info.ublksrv_pid = ublksrv_pid; |
2731 | pr_devel("%s: new ublksrv_pid %d, dev id %d\n" , |
2732 | __func__, ublksrv_pid, header->dev_id); |
2733 | blk_mq_unquiesce_queue(q: ub->ub_disk->queue); |
2734 | pr_devel("%s: queue unquiesced, dev id %d.\n" , |
2735 | __func__, header->dev_id); |
2736 | blk_mq_kick_requeue_list(q: ub->ub_disk->queue); |
2737 | ub->dev_info.state = UBLK_S_DEV_LIVE; |
2738 | ret = 0; |
2739 | out_unlock: |
2740 | mutex_unlock(lock: &ub->mutex); |
2741 | return ret; |
2742 | } |
2743 | |
2744 | static int ublk_ctrl_get_features(struct io_uring_cmd *cmd) |
2745 | { |
2746 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2747 | void __user *argp = (void __user *)(unsigned long)header->addr; |
2748 | u64 features = UBLK_F_ALL & ~UBLK_F_SUPPORT_ZERO_COPY; |
2749 | |
2750 | if (header->len != UBLK_FEATURES_LEN || !header->addr) |
2751 | return -EINVAL; |
2752 | |
2753 | if (copy_to_user(to: argp, from: &features, UBLK_FEATURES_LEN)) |
2754 | return -EFAULT; |
2755 | |
2756 | return 0; |
2757 | } |
2758 | |
2759 | /* |
2760 | * All control commands are sent via /dev/ublk-control, so we have to check |
2761 | * the destination device's permission |
2762 | */ |
2763 | static int ublk_char_dev_permission(struct ublk_device *ub, |
2764 | const char *dev_path, int mask) |
2765 | { |
2766 | int err; |
2767 | struct path path; |
2768 | struct kstat stat; |
2769 | |
2770 | err = kern_path(dev_path, LOOKUP_FOLLOW, &path); |
2771 | if (err) |
2772 | return err; |
2773 | |
2774 | err = vfs_getattr(&path, &stat, STATX_TYPE, AT_STATX_SYNC_AS_STAT); |
2775 | if (err) |
2776 | goto exit; |
2777 | |
2778 | err = -EPERM; |
2779 | if (stat.rdev != ub->cdev_dev.devt || !S_ISCHR(stat.mode)) |
2780 | goto exit; |
2781 | |
2782 | err = inode_permission(&nop_mnt_idmap, |
2783 | d_backing_inode(upper: path.dentry), mask); |
2784 | exit: |
2785 | path_put(&path); |
2786 | return err; |
2787 | } |
2788 | |
2789 | static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub, |
2790 | struct io_uring_cmd *cmd) |
2791 | { |
2792 | struct ublksrv_ctrl_cmd * = (struct ublksrv_ctrl_cmd *)io_uring_sqe_cmd(sqe: cmd->sqe); |
2793 | bool unprivileged = ub->dev_info.flags & UBLK_F_UNPRIVILEGED_DEV; |
2794 | void __user *argp = (void __user *)(unsigned long)header->addr; |
2795 | char *dev_path = NULL; |
2796 | int ret = 0; |
2797 | int mask; |
2798 | |
2799 | if (!unprivileged) { |
2800 | if (!capable(CAP_SYS_ADMIN)) |
2801 | return -EPERM; |
2802 | /* |
2803 | * The new added command of UBLK_CMD_GET_DEV_INFO2 includes |
2804 | * char_dev_path in payload too, since userspace may not |
2805 | * know if the specified device is created as unprivileged |
2806 | * mode. |
2807 | */ |
2808 | if (_IOC_NR(cmd->cmd_op) != UBLK_CMD_GET_DEV_INFO2) |
2809 | return 0; |
2810 | } |
2811 | |
2812 | /* |
2813 | * User has to provide the char device path for unprivileged ublk |
2814 | * |
2815 | * header->addr always points to the dev path buffer, and |
2816 | * header->dev_path_len records length of dev path buffer. |
2817 | */ |
2818 | if (!header->dev_path_len || header->dev_path_len > PATH_MAX) |
2819 | return -EINVAL; |
2820 | |
2821 | if (header->len < header->dev_path_len) |
2822 | return -EINVAL; |
2823 | |
2824 | dev_path = memdup_user_nul(argp, header->dev_path_len); |
2825 | if (IS_ERR(ptr: dev_path)) |
2826 | return PTR_ERR(ptr: dev_path); |
2827 | |
2828 | ret = -EINVAL; |
2829 | switch (_IOC_NR(cmd->cmd_op)) { |
2830 | case UBLK_CMD_GET_DEV_INFO: |
2831 | case UBLK_CMD_GET_DEV_INFO2: |
2832 | case UBLK_CMD_GET_QUEUE_AFFINITY: |
2833 | case UBLK_CMD_GET_PARAMS: |
2834 | case (_IOC_NR(UBLK_U_CMD_GET_FEATURES)): |
2835 | mask = MAY_READ; |
2836 | break; |
2837 | case UBLK_CMD_START_DEV: |
2838 | case UBLK_CMD_STOP_DEV: |
2839 | case UBLK_CMD_ADD_DEV: |
2840 | case UBLK_CMD_DEL_DEV: |
2841 | case UBLK_CMD_SET_PARAMS: |
2842 | case UBLK_CMD_START_USER_RECOVERY: |
2843 | case UBLK_CMD_END_USER_RECOVERY: |
2844 | mask = MAY_READ | MAY_WRITE; |
2845 | break; |
2846 | default: |
2847 | goto exit; |
2848 | } |
2849 | |
2850 | ret = ublk_char_dev_permission(ub, dev_path, mask); |
2851 | if (!ret) { |
2852 | header->len -= header->dev_path_len; |
2853 | header->addr += header->dev_path_len; |
2854 | } |
2855 | pr_devel("%s: dev id %d cmd_op %x uid %d gid %d path %s ret %d\n" , |
2856 | __func__, ub->ub_number, cmd->cmd_op, |
2857 | ub->dev_info.owner_uid, ub->dev_info.owner_gid, |
2858 | dev_path, ret); |
2859 | exit: |
2860 | kfree(objp: dev_path); |
2861 | return ret; |
2862 | } |
2863 | |
2864 | static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd, |
2865 | unsigned int issue_flags) |
2866 | { |
2867 | const struct ublksrv_ctrl_cmd * = io_uring_sqe_cmd(sqe: cmd->sqe); |
2868 | struct ublk_device *ub = NULL; |
2869 | u32 cmd_op = cmd->cmd_op; |
2870 | int ret = -EINVAL; |
2871 | |
2872 | if (issue_flags & IO_URING_F_NONBLOCK) |
2873 | return -EAGAIN; |
2874 | |
2875 | ublk_ctrl_cmd_dump(cmd); |
2876 | |
2877 | if (!(issue_flags & IO_URING_F_SQE128)) |
2878 | goto out; |
2879 | |
2880 | ret = ublk_check_cmd_op(cmd_op); |
2881 | if (ret) |
2882 | goto out; |
2883 | |
2884 | if (cmd_op == UBLK_U_CMD_GET_FEATURES) { |
2885 | ret = ublk_ctrl_get_features(cmd); |
2886 | goto out; |
2887 | } |
2888 | |
2889 | if (_IOC_NR(cmd_op) != UBLK_CMD_ADD_DEV) { |
2890 | ret = -ENODEV; |
2891 | ub = ublk_get_device_from_id(idx: header->dev_id); |
2892 | if (!ub) |
2893 | goto out; |
2894 | |
2895 | ret = ublk_ctrl_uring_cmd_permission(ub, cmd); |
2896 | if (ret) |
2897 | goto put_dev; |
2898 | } |
2899 | |
2900 | switch (_IOC_NR(cmd_op)) { |
2901 | case UBLK_CMD_START_DEV: |
2902 | ret = ublk_ctrl_start_dev(ub, cmd); |
2903 | break; |
2904 | case UBLK_CMD_STOP_DEV: |
2905 | ret = ublk_ctrl_stop_dev(ub); |
2906 | break; |
2907 | case UBLK_CMD_GET_DEV_INFO: |
2908 | case UBLK_CMD_GET_DEV_INFO2: |
2909 | ret = ublk_ctrl_get_dev_info(ub, cmd); |
2910 | break; |
2911 | case UBLK_CMD_ADD_DEV: |
2912 | ret = ublk_ctrl_add_dev(cmd); |
2913 | break; |
2914 | case UBLK_CMD_DEL_DEV: |
2915 | ret = ublk_ctrl_del_dev(p_ub: &ub); |
2916 | break; |
2917 | case UBLK_CMD_GET_QUEUE_AFFINITY: |
2918 | ret = ublk_ctrl_get_queue_affinity(ub, cmd); |
2919 | break; |
2920 | case UBLK_CMD_GET_PARAMS: |
2921 | ret = ublk_ctrl_get_params(ub, cmd); |
2922 | break; |
2923 | case UBLK_CMD_SET_PARAMS: |
2924 | ret = ublk_ctrl_set_params(ub, cmd); |
2925 | break; |
2926 | case UBLK_CMD_START_USER_RECOVERY: |
2927 | ret = ublk_ctrl_start_recovery(ub, cmd); |
2928 | break; |
2929 | case UBLK_CMD_END_USER_RECOVERY: |
2930 | ret = ublk_ctrl_end_recovery(ub, cmd); |
2931 | break; |
2932 | default: |
2933 | ret = -ENOTSUPP; |
2934 | break; |
2935 | } |
2936 | |
2937 | put_dev: |
2938 | if (ub) |
2939 | ublk_put_device(ub); |
2940 | out: |
2941 | io_uring_cmd_done(cmd, ret, res2: 0, issue_flags); |
2942 | pr_devel("%s: cmd done ret %d cmd_op %x, dev id %d qid %d\n" , |
2943 | __func__, ret, cmd->cmd_op, header->dev_id, header->queue_id); |
2944 | return -EIOCBQUEUED; |
2945 | } |
2946 | |
2947 | static const struct file_operations ublk_ctl_fops = { |
2948 | .open = nonseekable_open, |
2949 | .uring_cmd = ublk_ctrl_uring_cmd, |
2950 | .owner = THIS_MODULE, |
2951 | .llseek = noop_llseek, |
2952 | }; |
2953 | |
2954 | static struct miscdevice ublk_misc = { |
2955 | .minor = MISC_DYNAMIC_MINOR, |
2956 | .name = "ublk-control" , |
2957 | .fops = &ublk_ctl_fops, |
2958 | }; |
2959 | |
2960 | static int __init ublk_init(void) |
2961 | { |
2962 | int ret; |
2963 | |
2964 | BUILD_BUG_ON((u64)UBLKSRV_IO_BUF_OFFSET + |
2965 | UBLKSRV_IO_BUF_TOTAL_SIZE < UBLKSRV_IO_BUF_OFFSET); |
2966 | |
2967 | init_waitqueue_head(&ublk_idr_wq); |
2968 | |
2969 | ret = misc_register(misc: &ublk_misc); |
2970 | if (ret) |
2971 | return ret; |
2972 | |
2973 | ret = alloc_chrdev_region(&ublk_chr_devt, 0, UBLK_MINORS, "ublk-char" ); |
2974 | if (ret) |
2975 | goto unregister_mis; |
2976 | |
2977 | ret = class_register(class: &ublk_chr_class); |
2978 | if (ret) |
2979 | goto free_chrdev_region; |
2980 | |
2981 | return 0; |
2982 | |
2983 | free_chrdev_region: |
2984 | unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); |
2985 | unregister_mis: |
2986 | misc_deregister(misc: &ublk_misc); |
2987 | return ret; |
2988 | } |
2989 | |
2990 | static void __exit ublk_exit(void) |
2991 | { |
2992 | struct ublk_device *ub; |
2993 | int id; |
2994 | |
2995 | idr_for_each_entry(&ublk_index_idr, ub, id) |
2996 | ublk_remove(ub); |
2997 | |
2998 | class_unregister(class: &ublk_chr_class); |
2999 | misc_deregister(misc: &ublk_misc); |
3000 | |
3001 | idr_destroy(&ublk_index_idr); |
3002 | unregister_chrdev_region(ublk_chr_devt, UBLK_MINORS); |
3003 | } |
3004 | |
3005 | module_init(ublk_init); |
3006 | module_exit(ublk_exit); |
3007 | |
3008 | static int ublk_set_max_ublks(const char *buf, const struct kernel_param *kp) |
3009 | { |
3010 | return param_set_uint_minmax(val: buf, kp, min: 0, UBLK_MAX_UBLKS); |
3011 | } |
3012 | |
3013 | static int ublk_get_max_ublks(char *buf, const struct kernel_param *kp) |
3014 | { |
3015 | return sysfs_emit(buf, fmt: "%u\n" , ublks_max); |
3016 | } |
3017 | |
3018 | static const struct kernel_param_ops ublk_max_ublks_ops = { |
3019 | .set = ublk_set_max_ublks, |
3020 | .get = ublk_get_max_ublks, |
3021 | }; |
3022 | |
3023 | module_param_cb(ublks_max, &ublk_max_ublks_ops, &ublks_max, 0644); |
3024 | MODULE_PARM_DESC(ublks_max, "max number of ublk devices allowed to add(default: 64)" ); |
3025 | |
3026 | MODULE_AUTHOR("Ming Lei <ming.lei@redhat.com>" ); |
3027 | MODULE_LICENSE("GPL" ); |
3028 | |