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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
[linux/fpc-iii.git] / drivers / block / virtio_blk.c
blob588479d58f52f1496d8395c99ec410a3c1a10da3
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 spin_unlock_irqrestore(&vblk->vq_lock, flags);
203 blk_mq_stop_hw_queue(hctx);
204 virtqueue_kick(vblk->vq);
205 return BLK_MQ_RQ_QUEUE_BUSY;
206 }
207 spin_unlock_irqrestore(&vblk->vq_lock, flags);
208
209 if (last)
210 virtqueue_kick(vblk->vq);
211 return BLK_MQ_RQ_QUEUE_OK;
212 }
213
214 /* return id (s/n) string for *disk to *id_str
215 */
216 static int virtblk_get_id(struct gendisk *disk, char *id_str)
217 {
218 struct virtio_blk *vblk = disk->private_data;
219 struct request *req;
220 struct bio *bio;
221 int err;
222
223 bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,
224 GFP_KERNEL);
225 if (IS_ERR(bio))
226 return PTR_ERR(bio);
227
228 req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);
229 if (IS_ERR(req)) {
230 bio_put(bio);
231 return PTR_ERR(req);
232 }
233
234 req->cmd_type = REQ_TYPE_SPECIAL;
235 err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
236 blk_put_request(req);
237
238 return err;
239 }
240
241 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
242 unsigned int cmd, unsigned long data)
243 {
244 struct gendisk *disk = bdev->bd_disk;
245 struct virtio_blk *vblk = disk->private_data;
246
247 /*
248 * Only allow the generic SCSI ioctls if the host can support it.
249 */
250 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
251 return -ENOTTY;
252
253 return scsi_cmd_blk_ioctl(bdev, mode, cmd,
254 (void __user *)data);
255 }
256
257 /* We provide getgeo only to please some old bootloader/partitioning tools */
258 static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
259 {
260 struct virtio_blk *vblk = bd->bd_disk->private_data;
261
262 /* see if the host passed in geometry config */
263 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
264 virtio_cread(vblk->vdev, struct virtio_blk_config,
265 geometry.cylinders, &geo->cylinders);
266 virtio_cread(vblk->vdev, struct virtio_blk_config,
267 geometry.heads, &geo->heads);
268 virtio_cread(vblk->vdev, struct virtio_blk_config,
269 geometry.sectors, &geo->sectors);
270 } else {
271 /* some standard values, similar to sd */
272 geo->heads = 1 << 6;
273 geo->sectors = 1 << 5;
274 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
275 }
276 return 0;
277 }
278
279 static const struct block_device_operations virtblk_fops = {
280 .ioctl = virtblk_ioctl,
281 .owner = THIS_MODULE,
282 .getgeo = virtblk_getgeo,
283 };
284
285 static int index_to_minor(int index)
286 {
287 return index << PART_BITS;
288 }
289
290 static int minor_to_index(int minor)
291 {
292 return minor >> PART_BITS;
293 }
294
295 static ssize_t virtblk_serial_show(struct device *dev,
296 struct device_attribute *attr, char *buf)
297 {
298 struct gendisk *disk = dev_to_disk(dev);
299 int err;
300
301 /* sysfs gives us a PAGE_SIZE buffer */
302 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
303
304 buf[VIRTIO_BLK_ID_BYTES] = '\0';
305 err = virtblk_get_id(disk, buf);
306 if (!err)
307 return strlen(buf);
308
309 if (err == -EIO) /* Unsupported? Make it empty. */
310 return 0;
311
312 return err;
313 }
314 DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
315
316 static void virtblk_config_changed_work(struct work_struct *work)
317 {
318 struct virtio_blk *vblk =
319 container_of(work, struct virtio_blk, config_work);
320 struct virtio_device *vdev = vblk->vdev;
321 struct request_queue *q = vblk->disk->queue;
322 char cap_str_2[10], cap_str_10[10];
323 char *envp[] = { "RESIZE=1", NULL };
324 u64 capacity, size;
325
326 mutex_lock(&vblk->config_lock);
327 if (!vblk->config_enable)
328 goto done;
329
330 /* Host must always specify the capacity. */
331 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
332
333 /* If capacity is too big, truncate with warning. */
334 if ((sector_t)capacity != capacity) {
335 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
336 (unsigned long long)capacity);
337 capacity = (sector_t)-1;
338 }
339
340 size = capacity * queue_logical_block_size(q);
341 string_get_size(size, STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
342 string_get_size(size, STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
343
344 dev_notice(&vdev->dev,
345 "new size: %llu %d-byte logical blocks (%s/%s)\n",
346 (unsigned long long)capacity,
347 queue_logical_block_size(q),
348 cap_str_10, cap_str_2);
349
350 set_capacity(vblk->disk, capacity);
351 revalidate_disk(vblk->disk);
352 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
353 done:
354 mutex_unlock(&vblk->config_lock);
355 }
356
357 static void virtblk_config_changed(struct virtio_device *vdev)
358 {
359 struct virtio_blk *vblk = vdev->priv;
360
361 queue_work(virtblk_wq, &vblk->config_work);
362 }
363
364 static int init_vq(struct virtio_blk *vblk)
365 {
366 int err = 0;
367
368 /* We expect one virtqueue, for output. */
369 vblk->vq = virtio_find_single_vq(vblk->vdev, virtblk_done, "requests");
370 if (IS_ERR(vblk->vq))
371 err = PTR_ERR(vblk->vq);
372
373 return err;
374 }
375
376 /*
377 * Legacy naming scheme used for virtio devices. We are stuck with it for
378 * virtio blk but don't ever use it for any new driver.
379 */
380 static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
381 {
382 const int base = 'z' - 'a' + 1;
383 char *begin = buf + strlen(prefix);
384 char *end = buf + buflen;
385 char *p;
386 int unit;
387
388 p = end - 1;
389 *p = '\0';
390 unit = base;
391 do {
392 if (p == begin)
393 return -EINVAL;
394 *--p = 'a' + (index % unit);
395 index = (index / unit) - 1;
396 } while (index >= 0);
397
398 memmove(begin, p, end - p);
399 memcpy(buf, prefix, strlen(prefix));
400
401 return 0;
402 }
403
404 static int virtblk_get_cache_mode(struct virtio_device *vdev)
405 {
406 u8 writeback;
407 int err;
408
409 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
410 struct virtio_blk_config, wce,
411 &writeback);
412 if (err)
413 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE);
414
415 return writeback;
416 }
417
418 static void virtblk_update_cache_mode(struct virtio_device *vdev)
419 {
420 u8 writeback = virtblk_get_cache_mode(vdev);
421 struct virtio_blk *vblk = vdev->priv;
422
423 if (writeback)
424 blk_queue_flush(vblk->disk->queue, REQ_FLUSH);
425 else
426 blk_queue_flush(vblk->disk->queue, 0);
427
428 revalidate_disk(vblk->disk);
429 }
430
431 static const char *const virtblk_cache_types[] = {
432 "write through", "write back"
433 };
434
435 static ssize_t
436 virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
437 const char *buf, size_t count)
438 {
439 struct gendisk *disk = dev_to_disk(dev);
440 struct virtio_blk *vblk = disk->private_data;
441 struct virtio_device *vdev = vblk->vdev;
442 int i;
443
444 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
445 for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; )
446 if (sysfs_streq(buf, virtblk_cache_types[i]))
447 break;
448
449 if (i < 0)
450 return -EINVAL;
451
452 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
453 virtblk_update_cache_mode(vdev);
454 return count;
455 }
456
457 static ssize_t
458 virtblk_cache_type_show(struct device *dev, struct device_attribute *attr,
459 char *buf)
460 {
461 struct gendisk *disk = dev_to_disk(dev);
462 struct virtio_blk *vblk = disk->private_data;
463 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
464
465 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
466 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
467 }
468
469 static const struct device_attribute dev_attr_cache_type_ro =
470 __ATTR(cache_type, S_IRUGO,
471 virtblk_cache_type_show, NULL);
472 static const struct device_attribute dev_attr_cache_type_rw =
473 __ATTR(cache_type, S_IRUGO|S_IWUSR,
474 virtblk_cache_type_show, virtblk_cache_type_store);
475
476 static struct blk_mq_ops virtio_mq_ops = {
477 .queue_rq = virtio_queue_rq,
478 .map_queue = blk_mq_map_queue,
479 .alloc_hctx = blk_mq_alloc_single_hw_queue,
480 .free_hctx = blk_mq_free_single_hw_queue,
481 };
482
483 static struct blk_mq_reg virtio_mq_reg = {
484 .ops = &virtio_mq_ops,
485 .nr_hw_queues = 1,
486 .queue_depth = 64,
487 .numa_node = NUMA_NO_NODE,
488 .flags = BLK_MQ_F_SHOULD_MERGE,
489 };
490
491 static void virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx,
492 struct request *rq, unsigned int nr)
493 {
494 struct virtio_blk *vblk = data;
495 struct virtblk_req *vbr = rq->special;
496
497 sg_init_table(vbr->sg, vblk->sg_elems);
498 }
499
500 static int virtblk_probe(struct virtio_device *vdev)
501 {
502 struct virtio_blk *vblk;
503 struct request_queue *q;
504 int err, index;
505
506 u64 cap;
507 u32 v, blk_size, sg_elems, opt_io_size;
508 u16 min_io_size;
509 u8 physical_block_exp, alignment_offset;
510
511 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
512 GFP_KERNEL);
513 if (err < 0)
514 goto out;
515 index = err;
516
517 /* We need to know how many segments before we allocate. */
518 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
519 struct virtio_blk_config, seg_max,
520 &sg_elems);
521
522 /* We need at least one SG element, whatever they say. */
523 if (err || !sg_elems)
524 sg_elems = 1;
525
526 /* We need an extra sg elements at head and tail. */
527 sg_elems += 2;
528 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
529 if (!vblk) {
530 err = -ENOMEM;
531 goto out_free_index;
532 }
533
534 vblk->vdev = vdev;
535 vblk->sg_elems = sg_elems;
536 mutex_init(&vblk->config_lock);
537
538 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
539 vblk->config_enable = true;
540
541 err = init_vq(vblk);
542 if (err)
543 goto out_free_vblk;
544 spin_lock_init(&vblk->vq_lock);
545
546 /* FIXME: How many partitions? How long is a piece of string? */
547 vblk->disk = alloc_disk(1 << PART_BITS);
548 if (!vblk->disk) {
549 err = -ENOMEM;
550 goto out_free_vq;
551 }
552
553 virtio_mq_reg.cmd_size =
554 sizeof(struct virtblk_req) +
555 sizeof(struct scatterlist) * sg_elems;
556
557 q = vblk->disk->queue = blk_mq_init_queue(&virtio_mq_reg, vblk);
558 if (!q) {
559 err = -ENOMEM;
560 goto out_put_disk;
561 }
562
563 blk_mq_init_commands(q, virtblk_init_vbr, vblk);
564
565 q->queuedata = vblk;
566
567 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
568
569 vblk->disk->major = major;
570 vblk->disk->first_minor = index_to_minor(index);
571 vblk->disk->private_data = vblk;
572 vblk->disk->fops = &virtblk_fops;
573 vblk->disk->driverfs_dev = &vdev->dev;
574 vblk->index = index;
575
576 /* configure queue flush support */
577 virtblk_update_cache_mode(vdev);
578
579 /* If disk is read-only in the host, the guest should obey */
580 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
581 set_disk_ro(vblk->disk, 1);
582
583 /* Host must always specify the capacity. */
584 virtio_cread(vdev, struct virtio_blk_config, capacity, &cap);
585
586 /* If capacity is too big, truncate with warning. */
587 if ((sector_t)cap != cap) {
588 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
589 (unsigned long long)cap);
590 cap = (sector_t)-1;
591 }
592 set_capacity(vblk->disk, cap);
593
594 /* We can handle whatever the host told us to handle. */
595 blk_queue_max_segments(q, vblk->sg_elems-2);
596
597 /* No need to bounce any requests */
598 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
599
600 /* No real sector limit. */
601 blk_queue_max_hw_sectors(q, -1U);
602
603 /* Host can optionally specify maximum segment size and number of
604 * segments. */
605 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
606 struct virtio_blk_config, size_max, &v);
607 if (!err)
608 blk_queue_max_segment_size(q, v);
609 else
610 blk_queue_max_segment_size(q, -1U);
611
612 /* Host can optionally specify the block size of the device */
613 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
614 struct virtio_blk_config, blk_size,
615 &blk_size);
616 if (!err)
617 blk_queue_logical_block_size(q, blk_size);
618 else
619 blk_size = queue_logical_block_size(q);
620
621 /* Use topology information if available */
622 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
623 struct virtio_blk_config, physical_block_exp,
624 &physical_block_exp);
625 if (!err && physical_block_exp)
626 blk_queue_physical_block_size(q,
627 blk_size * (1 << physical_block_exp));
628
629 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
630 struct virtio_blk_config, alignment_offset,
631 &alignment_offset);
632 if (!err && alignment_offset)
633 blk_queue_alignment_offset(q, blk_size * alignment_offset);
634
635 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
636 struct virtio_blk_config, min_io_size,
637 &min_io_size);
638 if (!err && min_io_size)
639 blk_queue_io_min(q, blk_size * min_io_size);
640
641 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
642 struct virtio_blk_config, opt_io_size,
643 &opt_io_size);
644 if (!err && opt_io_size)
645 blk_queue_io_opt(q, blk_size * opt_io_size);
646
647 add_disk(vblk->disk);
648 err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
649 if (err)
650 goto out_del_disk;
651
652 if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
653 err = device_create_file(disk_to_dev(vblk->disk),
654 &dev_attr_cache_type_rw);
655 else
656 err = device_create_file(disk_to_dev(vblk->disk),
657 &dev_attr_cache_type_ro);
658 if (err)
659 goto out_del_disk;
660 return 0;
661
662 out_del_disk:
663 del_gendisk(vblk->disk);
664 blk_cleanup_queue(vblk->disk->queue);
665 out_put_disk:
666 put_disk(vblk->disk);
667 out_free_vq:
668 vdev->config->del_vqs(vdev);
669 out_free_vblk:
670 kfree(vblk);
671 out_free_index:
672 ida_simple_remove(&vd_index_ida, index);
673 out:
674 return err;
675 }
676
677 static void virtblk_remove(struct virtio_device *vdev)
678 {
679 struct virtio_blk *vblk = vdev->priv;
680 int index = vblk->index;
681 int refc;
682
683 /* Prevent config work handler from accessing the device. */
684 mutex_lock(&vblk->config_lock);
685 vblk->config_enable = false;
686 mutex_unlock(&vblk->config_lock);
687
688 del_gendisk(vblk->disk);
689 blk_cleanup_queue(vblk->disk->queue);
690
691 /* Stop all the virtqueues. */
692 vdev->config->reset(vdev);
693
694 flush_work(&vblk->config_work);
695
696 refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
697 put_disk(vblk->disk);
698 vdev->config->del_vqs(vdev);
699 kfree(vblk);
700
701 /* Only free device id if we don't have any users */
702 if (refc == 1)
703 ida_simple_remove(&vd_index_ida, index);
704 }
705
706 #ifdef CONFIG_PM_SLEEP
707 static int virtblk_freeze(struct virtio_device *vdev)
708 {
709 struct virtio_blk *vblk = vdev->priv;
710
711 /* Ensure we don't receive any more interrupts */
712 vdev->config->reset(vdev);
713
714 /* Prevent config work handler from accessing the device. */
715 mutex_lock(&vblk->config_lock);
716 vblk->config_enable = false;
717 mutex_unlock(&vblk->config_lock);
718
719 flush_work(&vblk->config_work);
720
721 blk_mq_stop_hw_queues(vblk->disk->queue);
722
723 vdev->config->del_vqs(vdev);
724 return 0;
725 }
726
727 static int virtblk_restore(struct virtio_device *vdev)
728 {
729 struct virtio_blk *vblk = vdev->priv;
730 int ret;
731
732 vblk->config_enable = true;
733 ret = init_vq(vdev->priv);
734 if (!ret)
735 blk_mq_start_stopped_hw_queues(vblk->disk->queue);
736
737 return ret;
738 }
739 #endif
740
741 static const struct virtio_device_id id_table[] = {
742 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
743 { 0 },
744 };
745
746 static unsigned int features[] = {
747 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
748 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
749 VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE
750 };
751
752 static struct virtio_driver virtio_blk = {
753 .feature_table = features,
754 .feature_table_size = ARRAY_SIZE(features),
755 .driver.name = KBUILD_MODNAME,
756 .driver.owner = THIS_MODULE,
757 .id_table = id_table,
758 .probe = virtblk_probe,
759 .remove = virtblk_remove,
760 .config_changed = virtblk_config_changed,
761 #ifdef CONFIG_PM_SLEEP
762 .freeze = virtblk_freeze,
763 .restore = virtblk_restore,
764 #endif
765 };
766
767 static int __init init(void)
768 {
769 int error;
770
771 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
772 if (!virtblk_wq)
773 return -ENOMEM;
774
775 major = register_blkdev(0, "virtblk");
776 if (major < 0) {
777 error = major;
778 goto out_destroy_workqueue;
779 }
780
781 error = register_virtio_driver(&virtio_blk);
782 if (error)
783 goto out_unregister_blkdev;
784 return 0;
785
786 out_unregister_blkdev:
787 unregister_blkdev(major, "virtblk");
788 out_destroy_workqueue:
789 destroy_workqueue(virtblk_wq);
790 return error;
791 }
792
793 static void __exit fini(void)
794 {
795 unregister_blkdev(major, "virtblk");
796 unregister_virtio_driver(&virtio_blk);
797 destroy_workqueue(virtblk_wq);
798 }
799 module_init(init);
800 module_exit(fini);
801
802 MODULE_DEVICE_TABLE(virtio, id_table);
803 MODULE_DESCRIPTION("Virtio block driver");
804 MODULE_LICENSE("GPL");
Linux with added FPC-III support