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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux/fpc-iii.git] / drivers / block / virtio_blk.c
blob6a680d4de7f1c3dcfa7999e45efc98b4b14d99fc
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");
Linux with added FPC-III support