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