1 //#define DEBUG 2 #include <linux/spinlock.h> 3 #include <linux/slab.h> 4 #include <linux/blkdev.h> 5 #include <linux/hdreg.h> 6 #include <linux/module.h> 7 #include <linux/mutex.h> 8 #include <linux/virtio.h> 9 #include <linux/virtio_blk.h> 10 #include <linux/scatterlist.h> 11 #include <linux/string_helpers.h> 12 #include <scsi/scsi_cmnd.h> 13 #include <linux/idr.h> 14 #include <linux/blk-mq.h> 15 #include <linux/numa.h> 16 17 #define PART_BITS 4 18 19 static int major; 20 static DEFINE_IDA(vd_index_ida); 21 22 static struct workqueue_struct *virtblk_wq; 23 24 struct virtio_blk 25 { 26 struct virtio_device *vdev; 27 struct virtqueue *vq; 28 spinlock_t vq_lock; 29 30 /* The disk structure for the kernel. */ 31 struct gendisk *disk; 32 33 /* Process context for config space updates */ 34 struct work_struct config_work; 35 36 /* Lock for config space updates */ 37 struct mutex config_lock; 38 39 /* enable config space updates */ 40 bool config_enable; 41 42 /* What host tells us, plus 2 for header & tailer. */ 43 unsigned int sg_elems; 44 45 /* Ida index - used to track minor number allocations. */ 46 int index; 47 }; 48 49 struct virtblk_req 50 { 51 struct request *req; 52 struct virtio_blk_outhdr out_hdr; 53 struct virtio_scsi_inhdr in_hdr; 54 u8 status; 55 struct scatterlist sg[]; 56 }; 57 58 static inline int virtblk_result(struct virtblk_req *vbr) 59 { 60 switch (vbr->status) { 61 case VIRTIO_BLK_S_OK: 62 return 0; 63 case VIRTIO_BLK_S_UNSUPP: 64 return -ENOTTY; 65 default: 66 return -EIO; 67 } 68 } 69 70 static int __virtblk_add_req(struct virtqueue *vq, 71 struct virtblk_req *vbr, 72 struct scatterlist *data_sg, 73 bool have_data) 74 { 75 struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6]; 76 unsigned int num_out = 0, num_in = 0; 77 int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT; 78 79 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); 80 sgs[num_out++] = &hdr; 81 82 /* 83 * If this is a packet command we need a couple of additional headers. 84 * Behind the normal outhdr we put a segment with the scsi command 85 * block, and before the normal inhdr we put the sense data and the 86 * inhdr with additional status information. 87 */ 88 if (type == VIRTIO_BLK_T_SCSI_CMD) { 89 sg_init_one(&cmd, vbr->req->cmd, vbr->req->cmd_len); 90 sgs[num_out++] = &cmd; 91 } 92 93 if (have_data) { 94 if (vbr->out_hdr.type & VIRTIO_BLK_T_OUT) 95 sgs[num_out++] = data_sg; 96 else 97 sgs[num_out + num_in++] = data_sg; 98 } 99 100 if (type == VIRTIO_BLK_T_SCSI_CMD) { 101 sg_init_one(&sense, vbr->req->sense, SCSI_SENSE_BUFFERSIZE); 102 sgs[num_out + num_in++] = &sense; 103 sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr)); 104 sgs[num_out + num_in++] = &inhdr; 105 } 106 107 sg_init_one(&status, &vbr->status, sizeof(vbr->status)); 108 sgs[num_out + num_in++] = &status; 109 110 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); 111 } 112 113 static inline void virtblk_request_done(struct virtblk_req *vbr) 114 { 115 struct request *req = vbr->req; 116 int error = virtblk_result(vbr); 117 118 if (req->cmd_type == REQ_TYPE_BLOCK_PC) { 119 req->resid_len = vbr->in_hdr.residual; 120 req->sense_len = vbr->in_hdr.sense_len; 121 req->errors = vbr->in_hdr.errors; 122 } else if (req->cmd_type == REQ_TYPE_SPECIAL) { 123 req->errors = (error != 0); 124 } 125 126 blk_mq_end_io(req, error); 127 } 128 129 static void virtblk_done(struct virtqueue *vq) 130 { 131 struct virtio_blk *vblk = vq->vdev->priv; 132 bool req_done = false; 133 struct virtblk_req *vbr; 134 unsigned long flags; 135 unsigned int len; 136 137 spin_lock_irqsave(&vblk->vq_lock, flags); 138 do { 139 virtqueue_disable_cb(vq); 140 while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) { 141 virtblk_request_done(vbr); 142 req_done = true; 143 } 144 if (unlikely(virtqueue_is_broken(vq))) 145 break; 146 } while (!virtqueue_enable_cb(vq)); 147 spin_unlock_irqrestore(&vblk->vq_lock, flags); 148 149 /* In case queue is stopped waiting for more buffers. */ 150 if (req_done) 151 blk_mq_start_stopped_hw_queues(vblk->disk->queue); 152 } 153 154 static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req) 155 { 156 struct virtio_blk *vblk = hctx->queue->queuedata; 157 struct virtblk_req *vbr = req->special; 158 unsigned long flags; 159 unsigned int num; 160 const bool last = (req->cmd_flags & REQ_END) != 0; 161 162 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems); 163 164 vbr->req = req; 165 if (req->cmd_flags & REQ_FLUSH) { 166 vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH; 167 vbr->out_hdr.sector = 0; 168 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req); 169 } else { 170 switch (req->cmd_type) { 171 case REQ_TYPE_FS: 172 vbr->out_hdr.type = 0; 173 vbr->out_hdr.sector = blk_rq_pos(vbr->req); 174 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req); 175 break; 176 case REQ_TYPE_BLOCK_PC: 177 vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD; 178 vbr->out_hdr.sector = 0; 179 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req); 180 break; 181 case REQ_TYPE_SPECIAL: 182 vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID; 183 vbr->out_hdr.sector = 0; 184 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req); 185 break; 186 default: 187 /* We don't put anything else in the queue. */ 188 BUG(); 189 } 190 } 191 192 num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg); 193 if (num) { 194 if (rq_data_dir(vbr->req) == WRITE) 195 vbr->out_hdr.type |= VIRTIO_BLK_T_OUT; 196 else 197 vbr->out_hdr.type |= VIRTIO_BLK_T_IN; 198 } 199 200 spin_lock_irqsave(&vblk->vq_lock, flags); 201 if (__virtblk_add_req(vblk->vq, vbr, vbr->sg, num) < 0) { 202 virtqueue_kick(vblk->vq); 203 spin_unlock_irqrestore(&vblk->vq_lock, flags); 204 blk_mq_stop_hw_queue(hctx); 205 return BLK_MQ_RQ_QUEUE_BUSY; 206 } 207 208 if (last) 209 virtqueue_kick(vblk->vq); 210 211 spin_unlock_irqrestore(&vblk->vq_lock, flags); 212 return BLK_MQ_RQ_QUEUE_OK; 213 } 214 215 /* return id (s/n) string for *disk to *id_str 216 */ 217 static int virtblk_get_id(struct gendisk *disk, char *id_str) 218 { 219 struct virtio_blk *vblk = disk->private_data; 220 struct request *req; 221 struct bio *bio; 222 int err; 223 224 bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES, 225 GFP_KERNEL); 226 if (IS_ERR(bio)) 227 return PTR_ERR(bio); 228 229 req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL); 230 if (IS_ERR(req)) { 231 bio_put(bio); 232 return PTR_ERR(req); 233 } 234 235 req->cmd_type = REQ_TYPE_SPECIAL; 236 err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false); 237 blk_put_request(req); 238 239 return err; 240 } 241 242 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode, 243 unsigned int cmd, unsigned long data) 244 { 245 struct gendisk *disk = bdev->bd_disk; 246 struct virtio_blk *vblk = disk->private_data; 247 248 /* 249 * Only allow the generic SCSI ioctls if the host can support it. 250 */ 251 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI)) 252 return -ENOTTY; 253 254 return scsi_cmd_blk_ioctl(bdev, mode, cmd, 255 (void __user *)data); 256 } 257 258 /* We provide getgeo only to please some old bootloader/partitioning tools */ 259 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) 260 { 261 struct virtio_blk *vblk = bd->bd_disk->private_data; 262 263 /* see if the host passed in geometry config */ 264 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { 265 virtio_cread(vblk->vdev, struct virtio_blk_config, 266 geometry.cylinders, &geo->cylinders); 267 virtio_cread(vblk->vdev, struct virtio_blk_config, 268 geometry.heads, &geo->heads); 269 virtio_cread(vblk->vdev, struct virtio_blk_config, 270 geometry.sectors, &geo->sectors); 271 } else { 272 /* some standard values, similar to sd */ 273 geo->heads = 1 << 6; 274 geo->sectors = 1 << 5; 275 geo->cylinders = get_capacity(bd->bd_disk) >> 11; 276 } 277 return 0; 278 } 279 280 static const struct block_device_operations virtblk_fops = { 281 .ioctl = virtblk_ioctl, 282 .owner = THIS_MODULE, 283 .getgeo = virtblk_getgeo, 284 }; 285 286 static int index_to_minor(int index) 287 { 288 return index << PART_BITS; 289 } 290 291 static int minor_to_index(int minor) 292 { 293 return minor >> PART_BITS; 294 } 295 296 static ssize_t virtblk_serial_show(struct device *dev, 297 struct device_attribute *attr, char *buf) 298 { 299 struct gendisk *disk = dev_to_disk(dev); 300 int err; 301 302 /* sysfs gives us a PAGE_SIZE buffer */ 303 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); 304 305 buf[VIRTIO_BLK_ID_BYTES] = '\0'; 306 err = virtblk_get_id(disk, buf); 307 if (!err) 308 return strlen(buf); 309 310 if (err == -EIO) /* Unsupported? Make it empty. */ 311 return 0; 312 313 return err; 314 } 315 DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL); 316 317 static void virtblk_config_changed_work(struct work_struct *work) 318 { 319 struct virtio_blk *vblk = 320 container_of(work, struct virtio_blk, config_work); 321 struct virtio_device *vdev = vblk->vdev; 322 struct request_queue *q = vblk->disk->queue; 323 char cap_str_2[10], cap_str_10[10]; 324 char *envp[] = { "RESIZE=1", NULL }; 325 u64 capacity, size; 326 327 mutex_lock(&vblk->config_lock); 328 if (!vblk->config_enable) 329 goto done; 330 331 /* Host must always specify the capacity. */ 332 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); 333 334 /* If capacity is too big, truncate with warning. */ 335 if ((sector_t)capacity != capacity) { 336 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n", 337 (unsigned long long)capacity); 338 capacity = (sector_t)-1; 339 } 340 341 size = capacity * queue_logical_block_size(q); 342 string_get_size(size, STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); 343 string_get_size(size, STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); 344 345 dev_notice(&vdev->dev, 346 "new size: %llu %d-byte logical blocks (%s/%s)\n", 347 (unsigned long long)capacity, 348 queue_logical_block_size(q), 349 cap_str_10, cap_str_2); 350 351 set_capacity(vblk->disk, capacity); 352 revalidate_disk(vblk->disk); 353 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp); 354 done: 355 mutex_unlock(&vblk->config_lock); 356 } 357 358 static void virtblk_config_changed(struct virtio_device *vdev) 359 { 360 struct virtio_blk *vblk = vdev->priv; 361 362 queue_work(virtblk_wq, &vblk->config_work); 363 } 364 365 static int init_vq(struct virtio_blk *vblk) 366 { 367 int err = 0; 368 369 /* We expect one virtqueue, for output. */ 370 vblk->vq = virtio_find_single_vq(vblk->vdev, virtblk_done, "requests"); 371 if (IS_ERR(vblk->vq)) 372 err = PTR_ERR(vblk->vq); 373 374 return err; 375 } 376 377 /* 378 * Legacy naming scheme used for virtio devices. We are stuck with it for 379 * virtio blk but don't ever use it for any new driver. 380 */ 381 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) 382 { 383 const int base = 'z' - 'a' + 1; 384 char *begin = buf + strlen(prefix); 385 char *end = buf + buflen; 386 char *p; 387 int unit; 388 389 p = end - 1; 390 *p = '\0'; 391 unit = base; 392 do { 393 if (p == begin) 394 return -EINVAL; 395 *--p = 'a' + (index % unit); 396 index = (index / unit) - 1; 397 } while (index >= 0); 398 399 memmove(begin, p, end - p); 400 memcpy(buf, prefix, strlen(prefix)); 401 402 return 0; 403 } 404 405 static int virtblk_get_cache_mode(struct virtio_device *vdev) 406 { 407 u8 writeback; 408 int err; 409 410 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, 411 struct virtio_blk_config, wce, 412 &writeback); 413 if (err) 414 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE); 415 416 return writeback; 417 } 418 419 static void virtblk_update_cache_mode(struct virtio_device *vdev) 420 { 421 u8 writeback = virtblk_get_cache_mode(vdev); 422 struct virtio_blk *vblk = vdev->priv; 423 424 if (writeback) 425 blk_queue_flush(vblk->disk->queue, REQ_FLUSH); 426 else 427 blk_queue_flush(vblk->disk->queue, 0); 428 429 revalidate_disk(vblk->disk); 430 } 431 432 static const char *const virtblk_cache_types[] = { 433 "write through", "write back" 434 }; 435 436 static ssize_t 437 virtblk_cache_type_store(struct device *dev, struct device_attribute *attr, 438 const char *buf, size_t count) 439 { 440 struct gendisk *disk = dev_to_disk(dev); 441 struct virtio_blk *vblk = disk->private_data; 442 struct virtio_device *vdev = vblk->vdev; 443 int i; 444 445 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); 446 for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; ) 447 if (sysfs_streq(buf, virtblk_cache_types[i])) 448 break; 449 450 if (i < 0) 451 return -EINVAL; 452 453 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); 454 virtblk_update_cache_mode(vdev); 455 return count; 456 } 457 458 static ssize_t 459 virtblk_cache_type_show(struct device *dev, struct device_attribute *attr, 460 char *buf) 461 { 462 struct gendisk *disk = dev_to_disk(dev); 463 struct virtio_blk *vblk = disk->private_data; 464 u8 writeback = virtblk_get_cache_mode(vblk->vdev); 465 466 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); 467 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]); 468 } 469 470 static const struct device_attribute dev_attr_cache_type_ro = 471 __ATTR(cache_type, S_IRUGO, 472 virtblk_cache_type_show, NULL); 473 static const struct device_attribute dev_attr_cache_type_rw = 474 __ATTR(cache_type, S_IRUGO|S_IWUSR, 475 virtblk_cache_type_show, virtblk_cache_type_store); 476 477 static struct blk_mq_ops virtio_mq_ops = { 478 .queue_rq = virtio_queue_rq, 479 .map_queue = blk_mq_map_queue, 480 .alloc_hctx = blk_mq_alloc_single_hw_queue, 481 .free_hctx = blk_mq_free_single_hw_queue, 482 }; 483 484 static struct blk_mq_reg virtio_mq_reg = { 485 .ops = &virtio_mq_ops, 486 .nr_hw_queues = 1, 487 .queue_depth = 64, 488 .numa_node = NUMA_NO_NODE, 489 .flags = BLK_MQ_F_SHOULD_MERGE, 490 }; 491 492 static void virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx, 493 struct request *rq, unsigned int nr) 494 { 495 struct virtio_blk *vblk = data; 496 struct virtblk_req *vbr = rq->special; 497 498 sg_init_table(vbr->sg, vblk->sg_elems); 499 } 500 501 static int virtblk_probe(struct virtio_device *vdev) 502 { 503 struct virtio_blk *vblk; 504 struct request_queue *q; 505 int err, index; 506 507 u64 cap; 508 u32 v, blk_size, sg_elems, opt_io_size; 509 u16 min_io_size; 510 u8 physical_block_exp, alignment_offset; 511 512 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS), 513 GFP_KERNEL); 514 if (err < 0) 515 goto out; 516 index = err; 517 518 /* We need to know how many segments before we allocate. */ 519 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, 520 struct virtio_blk_config, seg_max, 521 &sg_elems); 522 523 /* We need at least one SG element, whatever they say. */ 524 if (err || !sg_elems) 525 sg_elems = 1; 526 527 /* We need an extra sg elements at head and tail. */ 528 sg_elems += 2; 529 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); 530 if (!vblk) { 531 err = -ENOMEM; 532 goto out_free_index; 533 } 534 535 vblk->vdev = vdev; 536 vblk->sg_elems = sg_elems; 537 mutex_init(&vblk->config_lock); 538 539 INIT_WORK(&vblk->config_work, virtblk_config_changed_work); 540 vblk->config_enable = true; 541 542 err = init_vq(vblk); 543 if (err) 544 goto out_free_vblk; 545 spin_lock_init(&vblk->vq_lock); 546 547 /* FIXME: How many partitions? How long is a piece of string? */ 548 vblk->disk = alloc_disk(1 << PART_BITS); 549 if (!vblk->disk) { 550 err = -ENOMEM; 551 goto out_free_vq; 552 } 553 554 virtio_mq_reg.cmd_size = 555 sizeof(struct virtblk_req) + 556 sizeof(struct scatterlist) * sg_elems; 557 558 q = vblk->disk->queue = blk_mq_init_queue(&virtio_mq_reg, vblk); 559 if (!q) { 560 err = -ENOMEM; 561 goto out_put_disk; 562 } 563 564 blk_mq_init_commands(q, virtblk_init_vbr, vblk); 565 566 q->queuedata = vblk; 567 568 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); 569 570 vblk->disk->major = major; 571 vblk->disk->first_minor = index_to_minor(index); 572 vblk->disk->private_data = vblk; 573 vblk->disk->fops = &virtblk_fops; 574 vblk->disk->driverfs_dev = &vdev->dev; 575 vblk->index = index; 576 577 /* configure queue flush support */ 578 virtblk_update_cache_mode(vdev); 579 580 /* If disk is read-only in the host, the guest should obey */ 581 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) 582 set_disk_ro(vblk->disk, 1); 583 584 /* Host must always specify the capacity. */ 585 virtio_cread(vdev, struct virtio_blk_config, capacity, &cap); 586 587 /* If capacity is too big, truncate with warning. */ 588 if ((sector_t)cap != cap) { 589 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n", 590 (unsigned long long)cap); 591 cap = (sector_t)-1; 592 } 593 set_capacity(vblk->disk, cap); 594 595 /* We can handle whatever the host told us to handle. */ 596 blk_queue_max_segments(q, vblk->sg_elems-2); 597 598 /* No need to bounce any requests */ 599 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY); 600 601 /* No real sector limit. */ 602 blk_queue_max_hw_sectors(q, -1U); 603 604 /* Host can optionally specify maximum segment size and number of 605 * segments. */ 606 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, 607 struct virtio_blk_config, size_max, &v); 608 if (!err) 609 blk_queue_max_segment_size(q, v); 610 else 611 blk_queue_max_segment_size(q, -1U); 612 613 /* Host can optionally specify the block size of the device */ 614 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, 615 struct virtio_blk_config, blk_size, 616 &blk_size); 617 if (!err) 618 blk_queue_logical_block_size(q, blk_size); 619 else 620 blk_size = queue_logical_block_size(q); 621 622 /* Use topology information if available */ 623 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 624 struct virtio_blk_config, physical_block_exp, 625 &physical_block_exp); 626 if (!err && physical_block_exp) 627 blk_queue_physical_block_size(q, 628 blk_size * (1 << physical_block_exp)); 629 630 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 631 struct virtio_blk_config, alignment_offset, 632 &alignment_offset); 633 if (!err && alignment_offset) 634 blk_queue_alignment_offset(q, blk_size * alignment_offset); 635 636 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 637 struct virtio_blk_config, min_io_size, 638 &min_io_size); 639 if (!err && min_io_size) 640 blk_queue_io_min(q, blk_size * min_io_size); 641 642 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, 643 struct virtio_blk_config, opt_io_size, 644 &opt_io_size); 645 if (!err && opt_io_size) 646 blk_queue_io_opt(q, blk_size * opt_io_size); 647 648 add_disk(vblk->disk); 649 err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial); 650 if (err) 651 goto out_del_disk; 652 653 if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) 654 err = device_create_file(disk_to_dev(vblk->disk), 655 &dev_attr_cache_type_rw); 656 else 657 err = device_create_file(disk_to_dev(vblk->disk), 658 &dev_attr_cache_type_ro); 659 if (err) 660 goto out_del_disk; 661 return 0; 662 663 out_del_disk: 664 del_gendisk(vblk->disk); 665 blk_cleanup_queue(vblk->disk->queue); 666 out_put_disk: 667 put_disk(vblk->disk); 668 out_free_vq: 669 vdev->config->del_vqs(vdev); 670 out_free_vblk: 671 kfree(vblk); 672 out_free_index: 673 ida_simple_remove(&vd_index_ida, index); 674 out: 675 return err; 676 } 677 678 static void virtblk_remove(struct virtio_device *vdev) 679 { 680 struct virtio_blk *vblk = vdev->priv; 681 int index = vblk->index; 682 int refc; 683 684 /* Prevent config work handler from accessing the device. */ 685 mutex_lock(&vblk->config_lock); 686 vblk->config_enable = false; 687 mutex_unlock(&vblk->config_lock); 688 689 del_gendisk(vblk->disk); 690 blk_cleanup_queue(vblk->disk->queue); 691 692 /* Stop all the virtqueues. */ 693 vdev->config->reset(vdev); 694 695 flush_work(&vblk->config_work); 696 697 refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount); 698 put_disk(vblk->disk); 699 vdev->config->del_vqs(vdev); 700 kfree(vblk); 701 702 /* Only free device id if we don't have any users */ 703 if (refc == 1) 704 ida_simple_remove(&vd_index_ida, index); 705 } 706 707 #ifdef CONFIG_PM_SLEEP 708 static int virtblk_freeze(struct virtio_device *vdev) 709 { 710 struct virtio_blk *vblk = vdev->priv; 711 712 /* Ensure we don't receive any more interrupts */ 713 vdev->config->reset(vdev); 714 715 /* Prevent config work handler from accessing the device. */ 716 mutex_lock(&vblk->config_lock); 717 vblk->config_enable = false; 718 mutex_unlock(&vblk->config_lock); 719 720 flush_work(&vblk->config_work); 721 722 blk_mq_stop_hw_queues(vblk->disk->queue); 723 724 vdev->config->del_vqs(vdev); 725 return 0; 726 } 727 728 static int virtblk_restore(struct virtio_device *vdev) 729 { 730 struct virtio_blk *vblk = vdev->priv; 731 int ret; 732 733 vblk->config_enable = true; 734 ret = init_vq(vdev->priv); 735 if (!ret) 736 blk_mq_start_stopped_hw_queues(vblk->disk->queue); 737 738 return ret; 739 } 740 #endif 741 742 static const struct virtio_device_id id_table[] = { 743 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, 744 { 0 }, 745 }; 746 747 static unsigned int features[] = { 748 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, 749 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI, 750 VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE 751 }; 752 753 static struct virtio_driver virtio_blk = { 754 .feature_table = features, 755 .feature_table_size = ARRAY_SIZE(features), 756 .driver.name = KBUILD_MODNAME, 757 .driver.owner = THIS_MODULE, 758 .id_table = id_table, 759 .probe = virtblk_probe, 760 .remove = virtblk_remove, 761 .config_changed = virtblk_config_changed, 762 #ifdef CONFIG_PM_SLEEP 763 .freeze = virtblk_freeze, 764 .restore = virtblk_restore, 765 #endif 766 }; 767 768 static int __init init(void) 769 { 770 int error; 771 772 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); 773 if (!virtblk_wq) 774 return -ENOMEM; 775 776 major = register_blkdev(0, "virtblk"); 777 if (major < 0) { 778 error = major; 779 goto out_destroy_workqueue; 780 } 781 782 error = register_virtio_driver(&virtio_blk); 783 if (error) 784 goto out_unregister_blkdev; 785 return 0; 786 787 out_unregister_blkdev: 788 unregister_blkdev(major, "virtblk"); 789 out_destroy_workqueue: 790 destroy_workqueue(virtblk_wq); 791 return error; 792 } 793 794 static void __exit fini(void) 795 { 796 unregister_blkdev(major, "virtblk"); 797 unregister_virtio_driver(&virtio_blk); 798 destroy_workqueue(virtblk_wq); 799 } 800 module_init(init); 801 module_exit(fini); 802 803 MODULE_DEVICE_TABLE(virtio, id_table); 804 MODULE_DESCRIPTION("Virtio block driver"); 805 MODULE_LICENSE("GPL"); 806