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blk-mq: fix deadlock when reading cpu_list
[mirror_ubuntu-artful-kernel.git] / drivers / block / virtio_blk.c
CommitLineData
e467cde2
RR
1//#define DEBUG
2#include <linux/spinlock.h>
5a0e3ad6 3#include <linux/slab.h>
e467cde2
RR
4#include <linux/blkdev.h>
5#include <linux/hdreg.h>
0c8d44f2 6#include <linux/module.h>
4678d6f9 7#include <linux/mutex.h>
e467cde2
RR
8#include <linux/virtio.h>
9#include <linux/virtio_blk.h>
3d1266c7 10#include <linux/scatterlist.h>
7a7c924c 11#include <linux/string_helpers.h>
6917f83f 12#include <scsi/scsi_cmnd.h>
5087a50e 13#include <linux/idr.h>
1cf7e9c6
JA
14#include <linux/blk-mq.h>
15#include <linux/numa.h>
3d1266c7 16
4f3bf19c 17#define PART_BITS 4
6a27b656 18#define VQ_NAME_LEN 16
e467cde2 19
5087a50e
MT
20static int major;
21static DEFINE_IDA(vd_index_ida);
22
2a647bfe 23static struct workqueue_struct *virtblk_wq;
4f3bf19c 24
6a27b656
ML
25struct virtio_blk_vq {
26 struct virtqueue *vq;
27 spinlock_t lock;
28 char name[VQ_NAME_LEN];
29} ____cacheline_aligned_in_smp;
30
bb6ec576 31struct virtio_blk {
e467cde2 32 struct virtio_device *vdev;
e467cde2
RR
33
34 /* The disk structure for the kernel. */
35 struct gendisk *disk;
36
24d2f903
CH
37 /* Block layer tags. */
38 struct blk_mq_tag_set tag_set;
39
7a7c924c
CH
40 /* Process context for config space updates */
41 struct work_struct config_work;
42
0864b79a
RR
43 /* What host tells us, plus 2 for header & tailer. */
44 unsigned int sg_elems;
45
5087a50e
MT
46 /* Ida index - used to track minor number allocations. */
47 int index;
6a27b656
ML
48
49 /* num of vqs */
50 int num_vqs;
51 struct virtio_blk_vq *vqs;
e467cde2
RR
52};
53
bb6ec576 54struct virtblk_req {
e467cde2
RR
55 struct request *req;
56 struct virtio_blk_outhdr out_hdr;
1cde26f9 57 struct virtio_scsi_inhdr in_hdr;
cb38fa23 58 u8 status;
a98755c5 59 struct scatterlist sg[];
e467cde2
RR
60};
61
a98755c5
AH
62static inline int virtblk_result(struct virtblk_req *vbr)
63{
64 switch (vbr->status) {
65 case VIRTIO_BLK_S_OK:
66 return 0;
67 case VIRTIO_BLK_S_UNSUPP:
68 return -ENOTTY;
69 default:
70 return -EIO;
71 }
72}
73
8f39db9d 74static int __virtblk_add_req(struct virtqueue *vq,
20af3cfd
PB
75 struct virtblk_req *vbr,
76 struct scatterlist *data_sg,
0a11cc36 77 bool have_data)
c85a1f91 78{
20af3cfd 79 struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6];
8f39db9d 80 unsigned int num_out = 0, num_in = 0;
19c1c5a6 81 __virtio32 type = vbr->out_hdr.type & ~cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT);
8f39db9d
PB
82
83 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
84 sgs[num_out++] = &hdr;
85
20af3cfd
PB
86 /*
87 * If this is a packet command we need a couple of additional headers.
88 * Behind the normal outhdr we put a segment with the scsi command
89 * block, and before the normal inhdr we put the sense data and the
90 * inhdr with additional status information.
91 */
19c1c5a6 92 if (type == cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_SCSI_CMD)) {
20af3cfd
PB
93 sg_init_one(&cmd, vbr->req->cmd, vbr->req->cmd_len);
94 sgs[num_out++] = &cmd;
95 }
96
0a11cc36 97 if (have_data) {
19c1c5a6 98 if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT))
20af3cfd 99 sgs[num_out++] = data_sg;
8f39db9d 100 else
20af3cfd
PB
101 sgs[num_out + num_in++] = data_sg;
102 }
103
19c1c5a6 104 if (type == cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_SCSI_CMD)) {
20af3cfd
PB
105 sg_init_one(&sense, vbr->req->sense, SCSI_SENSE_BUFFERSIZE);
106 sgs[num_out + num_in++] = &sense;
107 sg_init_one(&inhdr, &vbr->in_hdr, sizeof(vbr->in_hdr));
108 sgs[num_out + num_in++] = &inhdr;
8f39db9d
PB
109 }
110
111 sg_init_one(&status, &vbr->status, sizeof(vbr->status));
112 sgs[num_out + num_in++] = &status;
113
114 return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
5ee21a52
PB
115}
116
5124c285 117static inline void virtblk_request_done(struct request *req)
a98755c5 118{
9d74e257 119 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
19c1c5a6 120 struct virtio_blk *vblk = req->q->queuedata;
a98755c5
AH
121 int error = virtblk_result(vbr);
122
123 if (req->cmd_type == REQ_TYPE_BLOCK_PC) {
19c1c5a6
MT
124 req->resid_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.residual);
125 req->sense_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.sense_len);
126 req->errors = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors);
4f8c9510 127 } else if (req->cmd_type == REQ_TYPE_DRV_PRIV) {
a98755c5
AH
128 req->errors = (error != 0);
129 }
130
c8a446ad 131 blk_mq_end_request(req, error);
a98755c5
AH
132}
133
134static void virtblk_done(struct virtqueue *vq)
e467cde2
RR
135{
136 struct virtio_blk *vblk = vq->vdev->priv;
1cf7e9c6 137 bool req_done = false;
6a27b656 138 int qid = vq->index;
e467cde2 139 struct virtblk_req *vbr;
e467cde2 140 unsigned long flags;
a98755c5 141 unsigned int len;
e467cde2 142
6a27b656 143 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
bb811108
AH
144 do {
145 virtqueue_disable_cb(vq);
6a27b656 146 while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
5124c285 147 blk_mq_complete_request(vbr->req);
1cf7e9c6 148 req_done = true;
33659ebb 149 }
7f03b17d
HG
150 if (unlikely(virtqueue_is_broken(vq)))
151 break;
bb811108 152 } while (!virtqueue_enable_cb(vq));
1cf7e9c6 153
e467cde2 154 /* In case queue is stopped waiting for more buffers. */
a98755c5 155 if (req_done)
1b4a3258 156 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
6a27b656 157 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
a98755c5
AH
158}
159
74c45052
JA
160static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
161 const struct blk_mq_queue_data *bd)
e467cde2 162{
1cf7e9c6 163 struct virtio_blk *vblk = hctx->queue->queuedata;
74c45052 164 struct request *req = bd->rq;
9d74e257 165 struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
1cf7e9c6 166 unsigned long flags;
20af3cfd 167 unsigned int num;
6a27b656 168 int qid = hctx->queue_num;
5261b85e 169 int err;
e8edca6f 170 bool notify = false;
e467cde2 171
1cf7e9c6 172 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
e467cde2
RR
173
174 vbr->req = req;
dd40e456 175 if (req->cmd_flags & REQ_FLUSH) {
19c1c5a6 176 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_FLUSH);
4cb2ea28 177 vbr->out_hdr.sector = 0;
19c1c5a6 178 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req));
dd40e456
FT
179 } else {
180 switch (req->cmd_type) {
181 case REQ_TYPE_FS:
182 vbr->out_hdr.type = 0;
19c1c5a6
MT
183 vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, blk_rq_pos(vbr->req));
184 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req));
dd40e456
FT
185 break;
186 case REQ_TYPE_BLOCK_PC:
19c1c5a6 187 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_SCSI_CMD);
f1b0ef06 188 vbr->out_hdr.sector = 0;
19c1c5a6 189 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req));
f1b0ef06 190 break;
4f8c9510 191 case REQ_TYPE_DRV_PRIV:
19c1c5a6 192 vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_GET_ID);
dd40e456 193 vbr->out_hdr.sector = 0;
19c1c5a6 194 vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(vbr->req));
dd40e456
FT
195 break;
196 default:
197 /* We don't put anything else in the queue. */
198 BUG();
f1b0ef06 199 }
e467cde2
RR
200 }
201
e2490073
CH
202 blk_mq_start_request(req);
203
1cf7e9c6 204 num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg);
1cde26f9 205 if (num) {
20af3cfd 206 if (rq_data_dir(vbr->req) == WRITE)
19c1c5a6 207 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT);
20af3cfd 208 else
19c1c5a6 209 vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN);
e467cde2
RR
210 }
211
6a27b656
ML
212 spin_lock_irqsave(&vblk->vqs[qid].lock, flags);
213 err = __virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num);
5261b85e 214 if (err) {
6a27b656 215 virtqueue_kick(vblk->vqs[qid].vq);
1cf7e9c6 216 blk_mq_stop_hw_queue(hctx);
6a27b656 217 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
5261b85e
RR
218 /* Out of mem doesn't actually happen, since we fall back
219 * to direct descriptors */
220 if (err == -ENOMEM || err == -ENOSPC)
221 return BLK_MQ_RQ_QUEUE_BUSY;
222 return BLK_MQ_RQ_QUEUE_ERROR;
a98755c5
AH
223 }
224
74c45052 225 if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq))
e8edca6f 226 notify = true;
6a27b656 227 spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags);
e8edca6f
ML
228
229 if (notify)
6a27b656 230 virtqueue_notify(vblk->vqs[qid].vq);
1cf7e9c6 231 return BLK_MQ_RQ_QUEUE_OK;
a98755c5
AH
232}
233
4cb2ea28 234/* return id (s/n) string for *disk to *id_str
235 */
236static int virtblk_get_id(struct gendisk *disk, char *id_str)
237{
238 struct virtio_blk *vblk = disk->private_data;
239 struct request *req;
240 struct bio *bio;
e4c4776d 241 int err;
4cb2ea28 242
243 bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,
244 GFP_KERNEL);
245 if (IS_ERR(bio))
246 return PTR_ERR(bio);
247
248 req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);
249 if (IS_ERR(req)) {
250 bio_put(bio);
251 return PTR_ERR(req);
252 }
253
4f8c9510 254 req->cmd_type = REQ_TYPE_DRV_PRIV;
e4c4776d
MS
255 err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
256 blk_put_request(req);
257
258 return err;
4cb2ea28 259}
260
fe5a50a1
CH
261static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
262 unsigned int cmd, unsigned long data)
e467cde2 263{
1cde26f9
HR
264 struct gendisk *disk = bdev->bd_disk;
265 struct virtio_blk *vblk = disk->private_data;
266
267 /*
268 * Only allow the generic SCSI ioctls if the host can support it.
269 */
270 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
d9ecdea7 271 return -ENOTTY;
1cde26f9 272
577ebb37
PB
273 return scsi_cmd_blk_ioctl(bdev, mode, cmd,
274 (void __user *)data);
e467cde2
RR
275}
276
135da0b0
CB
277/* We provide getgeo only to please some old bootloader/partitioning tools */
278static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
279{
48e4043d 280 struct virtio_blk *vblk = bd->bd_disk->private_data;
48e4043d
RH
281
282 /* see if the host passed in geometry config */
855e0c52
RR
283 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
284 virtio_cread(vblk->vdev, struct virtio_blk_config,
285 geometry.cylinders, &geo->cylinders);
286 virtio_cread(vblk->vdev, struct virtio_blk_config,
287 geometry.heads, &geo->heads);
288 virtio_cread(vblk->vdev, struct virtio_blk_config,
289 geometry.sectors, &geo->sectors);
48e4043d
RH
290 } else {
291 /* some standard values, similar to sd */
292 geo->heads = 1 << 6;
293 geo->sectors = 1 << 5;
294 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
295 }
135da0b0
CB
296 return 0;
297}
298
83d5cde4 299static const struct block_device_operations virtblk_fops = {
8a6cfeb6 300 .ioctl = virtblk_ioctl,
135da0b0
CB
301 .owner = THIS_MODULE,
302 .getgeo = virtblk_getgeo,
e467cde2
RR
303};
304
d50ed907
CB
305static int index_to_minor(int index)
306{
307 return index << PART_BITS;
308}
309
5087a50e
MT
310static int minor_to_index(int minor)
311{
312 return minor >> PART_BITS;
313}
314
a5eb9e4f
RH
315static ssize_t virtblk_serial_show(struct device *dev,
316 struct device_attribute *attr, char *buf)
317{
318 struct gendisk *disk = dev_to_disk(dev);
319 int err;
320
321 /* sysfs gives us a PAGE_SIZE buffer */
322 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
323
324 buf[VIRTIO_BLK_ID_BYTES] = '\0';
325 err = virtblk_get_id(disk, buf);
326 if (!err)
327 return strlen(buf);
328
329 if (err == -EIO) /* Unsupported? Make it empty. */
330 return 0;
331
332 return err;
333}
393c525b
MT
334
335static DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
a5eb9e4f 336
7a7c924c
CH
337static void virtblk_config_changed_work(struct work_struct *work)
338{
339 struct virtio_blk *vblk =
340 container_of(work, struct virtio_blk, config_work);
341 struct virtio_device *vdev = vblk->vdev;
342 struct request_queue *q = vblk->disk->queue;
343 char cap_str_2[10], cap_str_10[10];
9d9598b8 344 char *envp[] = { "RESIZE=1", NULL };
b9f28d86 345 u64 capacity;
7a7c924c
CH
346
347 /* Host must always specify the capacity. */
855e0c52 348 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
7a7c924c
CH
349
350 /* If capacity is too big, truncate with warning. */
351 if ((sector_t)capacity != capacity) {
352 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
353 (unsigned long long)capacity);
354 capacity = (sector_t)-1;
355 }
356
b9f28d86
JB
357 string_get_size(capacity, queue_logical_block_size(q),
358 STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
359 string_get_size(capacity, queue_logical_block_size(q),
360 STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
7a7c924c
CH
361
362 dev_notice(&vdev->dev,
363 "new size: %llu %d-byte logical blocks (%s/%s)\n",
364 (unsigned long long)capacity,
365 queue_logical_block_size(q),
366 cap_str_10, cap_str_2);
367
368 set_capacity(vblk->disk, capacity);
e9986f30 369 revalidate_disk(vblk->disk);
9d9598b8 370 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
7a7c924c
CH
371}
372
373static void virtblk_config_changed(struct virtio_device *vdev)
374{
375 struct virtio_blk *vblk = vdev->priv;
376
377 queue_work(virtblk_wq, &vblk->config_work);
378}
379
6abd6e5a
AS
380static int init_vq(struct virtio_blk *vblk)
381{
382 int err = 0;
6a27b656
ML
383 int i;
384 vq_callback_t **callbacks;
385 const char **names;
386 struct virtqueue **vqs;
387 unsigned short num_vqs;
388 struct virtio_device *vdev = vblk->vdev;
389
390 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ,
391 struct virtio_blk_config, num_queues,
392 &num_vqs);
393 if (err)
394 num_vqs = 1;
395
396 vblk->vqs = kmalloc(sizeof(*vblk->vqs) * num_vqs, GFP_KERNEL);
397 if (!vblk->vqs) {
398 err = -ENOMEM;
399 goto out;
400 }
401
402 names = kmalloc(sizeof(*names) * num_vqs, GFP_KERNEL);
403 if (!names)
404 goto err_names;
405
406 callbacks = kmalloc(sizeof(*callbacks) * num_vqs, GFP_KERNEL);
407 if (!callbacks)
408 goto err_callbacks;
409
410 vqs = kmalloc(sizeof(*vqs) * num_vqs, GFP_KERNEL);
411 if (!vqs)
412 goto err_vqs;
6abd6e5a 413
6a27b656
ML
414 for (i = 0; i < num_vqs; i++) {
415 callbacks[i] = virtblk_done;
416 snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
417 names[i] = vblk->vqs[i].name;
418 }
419
420 /* Discover virtqueues and write information to configuration. */
421 err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
422 if (err)
423 goto err_find_vqs;
6abd6e5a 424
6a27b656
ML
425 for (i = 0; i < num_vqs; i++) {
426 spin_lock_init(&vblk->vqs[i].lock);
427 vblk->vqs[i].vq = vqs[i];
428 }
429 vblk->num_vqs = num_vqs;
430
431 err_find_vqs:
432 kfree(vqs);
433 err_vqs:
434 kfree(callbacks);
435 err_callbacks:
436 kfree(names);
437 err_names:
438 if (err)
439 kfree(vblk->vqs);
440 out:
6abd6e5a
AS
441 return err;
442}
443
c0aa3e09
RM
444/*
445 * Legacy naming scheme used for virtio devices. We are stuck with it for
446 * virtio blk but don't ever use it for any new driver.
447 */
448static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
449{
450 const int base = 'z' - 'a' + 1;
451 char *begin = buf + strlen(prefix);
452 char *end = buf + buflen;
453 char *p;
454 int unit;
455
456 p = end - 1;
457 *p = '\0';
458 unit = base;
459 do {
460 if (p == begin)
461 return -EINVAL;
462 *--p = 'a' + (index % unit);
463 index = (index / unit) - 1;
464 } while (index >= 0);
465
466 memmove(begin, p, end - p);
467 memcpy(buf, prefix, strlen(prefix));
468
469 return 0;
470}
471
cd5d5038
PB
472static int virtblk_get_cache_mode(struct virtio_device *vdev)
473{
474 u8 writeback;
475 int err;
476
855e0c52
RR
477 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
478 struct virtio_blk_config, wce,
479 &writeback);
cd5d5038 480 if (err)
53eab6fd 481 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE);
cd5d5038
PB
482
483 return writeback;
484}
485
486static void virtblk_update_cache_mode(struct virtio_device *vdev)
487{
488 u8 writeback = virtblk_get_cache_mode(vdev);
489 struct virtio_blk *vblk = vdev->priv;
490
c85a1f91 491 if (writeback)
cd5d5038
PB
492 blk_queue_flush(vblk->disk->queue, REQ_FLUSH);
493 else
494 blk_queue_flush(vblk->disk->queue, 0);
495
496 revalidate_disk(vblk->disk);
497}
498
499static const char *const virtblk_cache_types[] = {
500 "write through", "write back"
501};
502
503static ssize_t
504virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
505 const char *buf, size_t count)
506{
507 struct gendisk *disk = dev_to_disk(dev);
508 struct virtio_blk *vblk = disk->private_data;
509 struct virtio_device *vdev = vblk->vdev;
510 int i;
cd5d5038
PB
511
512 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
513 for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; )
514 if (sysfs_streq(buf, virtblk_cache_types[i]))
515 break;
516
517 if (i < 0)
518 return -EINVAL;
519
855e0c52 520 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
cd5d5038
PB
521 virtblk_update_cache_mode(vdev);
522 return count;
523}
524
525static ssize_t
526virtblk_cache_type_show(struct device *dev, struct device_attribute *attr,
527 char *buf)
528{
529 struct gendisk *disk = dev_to_disk(dev);
530 struct virtio_blk *vblk = disk->private_data;
531 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
532
533 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
534 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
535}
536
537static const struct device_attribute dev_attr_cache_type_ro =
538 __ATTR(cache_type, S_IRUGO,
539 virtblk_cache_type_show, NULL);
540static const struct device_attribute dev_attr_cache_type_rw =
541 __ATTR(cache_type, S_IRUGO|S_IWUSR,
542 virtblk_cache_type_show, virtblk_cache_type_store);
543
24d2f903
CH
544static int virtblk_init_request(void *data, struct request *rq,
545 unsigned int hctx_idx, unsigned int request_idx,
546 unsigned int numa_node)
e9b267d9
CH
547{
548 struct virtio_blk *vblk = data;
549 struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq);
550
551 sg_init_table(vbr->sg, vblk->sg_elems);
552 return 0;
553}
554
1cf7e9c6
JA
555static struct blk_mq_ops virtio_mq_ops = {
556 .queue_rq = virtio_queue_rq,
557 .map_queue = blk_mq_map_queue,
5124c285 558 .complete = virtblk_request_done,
24d2f903 559 .init_request = virtblk_init_request,
1cf7e9c6
JA
560};
561
24d2f903
CH
562static unsigned int virtblk_queue_depth;
563module_param_named(queue_depth, virtblk_queue_depth, uint, 0444);
1cf7e9c6 564
8d85fce7 565static int virtblk_probe(struct virtio_device *vdev)
e467cde2
RR
566{
567 struct virtio_blk *vblk;
69740c8b 568 struct request_queue *q;
5087a50e 569 int err, index;
a98755c5 570
e467cde2 571 u64 cap;
69740c8b
CH
572 u32 v, blk_size, sg_elems, opt_io_size;
573 u16 min_io_size;
574 u8 physical_block_exp, alignment_offset;
e467cde2 575
a4379fd8
MT
576 if (!vdev->config->get) {
577 dev_err(&vdev->dev, "%s failure: config access disabled\n",
578 __func__);
579 return -EINVAL;
580 }
581
5087a50e
MT
582 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
583 GFP_KERNEL);
584 if (err < 0)
585 goto out;
586 index = err;
4f3bf19c 587
0864b79a 588 /* We need to know how many segments before we allocate. */
855e0c52
RR
589 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
590 struct virtio_blk_config, seg_max,
591 &sg_elems);
a5b365a6
CH
592
593 /* We need at least one SG element, whatever they say. */
594 if (err || !sg_elems)
0864b79a
RR
595 sg_elems = 1;
596
597 /* We need an extra sg elements at head and tail. */
598 sg_elems += 2;
1cf7e9c6 599 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
e467cde2
RR
600 if (!vblk) {
601 err = -ENOMEM;
5087a50e 602 goto out_free_index;
e467cde2
RR
603 }
604
e467cde2 605 vblk->vdev = vdev;
0864b79a 606 vblk->sg_elems = sg_elems;
a98755c5 607
7a7c924c 608 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
e467cde2 609
6abd6e5a
AS
610 err = init_vq(vblk);
611 if (err)
e467cde2 612 goto out_free_vblk;
e467cde2 613
e467cde2 614 /* FIXME: How many partitions? How long is a piece of string? */
4f3bf19c 615 vblk->disk = alloc_disk(1 << PART_BITS);
e467cde2
RR
616 if (!vblk->disk) {
617 err = -ENOMEM;
1cf7e9c6 618 goto out_free_vq;
e467cde2
RR
619 }
620
fc4324b4 621 /* Default queue sizing is to fill the ring. */
24d2f903 622 if (!virtblk_queue_depth) {
6a27b656 623 virtblk_queue_depth = vblk->vqs[0].vq->num_free;
fc4324b4
RR
624 /* ... but without indirect descs, we use 2 descs per req */
625 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
24d2f903 626 virtblk_queue_depth /= 2;
fc4324b4 627 }
24d2f903
CH
628
629 memset(&vblk->tag_set, 0, sizeof(vblk->tag_set));
630 vblk->tag_set.ops = &virtio_mq_ops;
24d2f903
CH
631 vblk->tag_set.queue_depth = virtblk_queue_depth;
632 vblk->tag_set.numa_node = NUMA_NO_NODE;
633 vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
634 vblk->tag_set.cmd_size =
1cf7e9c6
JA
635 sizeof(struct virtblk_req) +
636 sizeof(struct scatterlist) * sg_elems;
24d2f903 637 vblk->tag_set.driver_data = vblk;
6a27b656 638 vblk->tag_set.nr_hw_queues = vblk->num_vqs;
1cf7e9c6 639
24d2f903
CH
640 err = blk_mq_alloc_tag_set(&vblk->tag_set);
641 if (err)
642 goto out_put_disk;
643
644 q = vblk->disk->queue = blk_mq_init_queue(&vblk->tag_set);
35b489d3 645 if (IS_ERR(q)) {
e467cde2 646 err = -ENOMEM;
24d2f903 647 goto out_free_tags;
e467cde2
RR
648 }
649
69740c8b 650 q->queuedata = vblk;
7d116b62 651
c0aa3e09 652 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
d50ed907 653
e467cde2 654 vblk->disk->major = major;
d50ed907 655 vblk->disk->first_minor = index_to_minor(index);
e467cde2
RR
656 vblk->disk->private_data = vblk;
657 vblk->disk->fops = &virtblk_fops;
c4839346 658 vblk->disk->driverfs_dev = &vdev->dev;
5fa3142d 659 vblk->disk->flags |= GENHD_FL_EXT_DEVT;
5087a50e 660 vblk->index = index;
4f3bf19c 661
02c42b7a 662 /* configure queue flush support */
cd5d5038 663 virtblk_update_cache_mode(vdev);
e467cde2 664
3ef53609
CB
665 /* If disk is read-only in the host, the guest should obey */
666 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
667 set_disk_ro(vblk->disk, 1);
668
a586d4f6 669 /* Host must always specify the capacity. */
855e0c52 670 virtio_cread(vdev, struct virtio_blk_config, capacity, &cap);
e467cde2
RR
671
672 /* If capacity is too big, truncate with warning. */
673 if ((sector_t)cap != cap) {
674 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
675 (unsigned long long)cap);
676 cap = (sector_t)-1;
677 }
678 set_capacity(vblk->disk, cap);
679
0864b79a 680 /* We can handle whatever the host told us to handle. */
ee714f2d 681 blk_queue_max_segments(q, vblk->sg_elems-2);
0864b79a 682
4eff3cae 683 /* No need to bounce any requests */
69740c8b 684 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
4eff3cae 685
4b7f7e20 686 /* No real sector limit. */
ee714f2d 687 blk_queue_max_hw_sectors(q, -1U);
4b7f7e20 688
a586d4f6
RR
689 /* Host can optionally specify maximum segment size and number of
690 * segments. */
855e0c52
RR
691 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
692 struct virtio_blk_config, size_max, &v);
e467cde2 693 if (!err)
69740c8b 694 blk_queue_max_segment_size(q, v);
4b7f7e20 695 else
69740c8b 696 blk_queue_max_segment_size(q, -1U);
e467cde2 697
066f4d82 698 /* Host can optionally specify the block size of the device */
855e0c52
RR
699 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
700 struct virtio_blk_config, blk_size,
701 &blk_size);
066f4d82 702 if (!err)
69740c8b
CH
703 blk_queue_logical_block_size(q, blk_size);
704 else
705 blk_size = queue_logical_block_size(q);
706
707 /* Use topology information if available */
855e0c52
RR
708 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
709 struct virtio_blk_config, physical_block_exp,
710 &physical_block_exp);
69740c8b
CH
711 if (!err && physical_block_exp)
712 blk_queue_physical_block_size(q,
713 blk_size * (1 << physical_block_exp));
714
855e0c52
RR
715 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
716 struct virtio_blk_config, alignment_offset,
717 &alignment_offset);
69740c8b
CH
718 if (!err && alignment_offset)
719 blk_queue_alignment_offset(q, blk_size * alignment_offset);
720
855e0c52
RR
721 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
722 struct virtio_blk_config, min_io_size,
723 &min_io_size);
69740c8b
CH
724 if (!err && min_io_size)
725 blk_queue_io_min(q, blk_size * min_io_size);
726
855e0c52
RR
727 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
728 struct virtio_blk_config, opt_io_size,
729 &opt_io_size);
69740c8b
CH
730 if (!err && opt_io_size)
731 blk_queue_io_opt(q, blk_size * opt_io_size);
732
7a11370e
MT
733 virtio_device_ready(vdev);
734
e467cde2 735 add_disk(vblk->disk);
a5eb9e4f
RH
736 err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
737 if (err)
738 goto out_del_disk;
739
cd5d5038
PB
740 if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
741 err = device_create_file(disk_to_dev(vblk->disk),
742 &dev_attr_cache_type_rw);
743 else
744 err = device_create_file(disk_to_dev(vblk->disk),
745 &dev_attr_cache_type_ro);
746 if (err)
747 goto out_del_disk;
e467cde2
RR
748 return 0;
749
a5eb9e4f
RH
750out_del_disk:
751 del_gendisk(vblk->disk);
752 blk_cleanup_queue(vblk->disk->queue);
24d2f903
CH
753out_free_tags:
754 blk_mq_free_tag_set(&vblk->tag_set);
e467cde2
RR
755out_put_disk:
756 put_disk(vblk->disk);
e467cde2 757out_free_vq:
d2a7ddda 758 vdev->config->del_vqs(vdev);
e467cde2
RR
759out_free_vblk:
760 kfree(vblk);
5087a50e
MT
761out_free_index:
762 ida_simple_remove(&vd_index_ida, index);
e467cde2
RR
763out:
764 return err;
765}
766
8d85fce7 767static void virtblk_remove(struct virtio_device *vdev)
e467cde2
RR
768{
769 struct virtio_blk *vblk = vdev->priv;
5087a50e 770 int index = vblk->index;
f4953fe6 771 int refc;
e467cde2 772
cc74f719
MT
773 /* Make sure no work handler is accessing the device. */
774 flush_work(&vblk->config_work);
7a7c924c 775
02e2b124 776 del_gendisk(vblk->disk);
483001c7 777 blk_cleanup_queue(vblk->disk->queue);
02e2b124 778
24d2f903
CH
779 blk_mq_free_tag_set(&vblk->tag_set);
780
6e5aa7ef
RR
781 /* Stop all the virtqueues. */
782 vdev->config->reset(vdev);
783
f4953fe6 784 refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
e467cde2 785 put_disk(vblk->disk);
d2a7ddda 786 vdev->config->del_vqs(vdev);
6a27b656 787 kfree(vblk->vqs);
e467cde2 788 kfree(vblk);
f4953fe6
AG
789
790 /* Only free device id if we don't have any users */
791 if (refc == 1)
792 ida_simple_remove(&vd_index_ida, index);
e467cde2
RR
793}
794
89107000 795#ifdef CONFIG_PM_SLEEP
f8fb5bc2
AS
796static int virtblk_freeze(struct virtio_device *vdev)
797{
798 struct virtio_blk *vblk = vdev->priv;
799
800 /* Ensure we don't receive any more interrupts */
801 vdev->config->reset(vdev);
802
cc74f719 803 /* Make sure no work handler is accessing the device. */
f8fb5bc2
AS
804 flush_work(&vblk->config_work);
805
1cf7e9c6 806 blk_mq_stop_hw_queues(vblk->disk->queue);
f8fb5bc2
AS
807
808 vdev->config->del_vqs(vdev);
809 return 0;
810}
811
812static int virtblk_restore(struct virtio_device *vdev)
813{
814 struct virtio_blk *vblk = vdev->priv;
815 int ret;
816
f8fb5bc2 817 ret = init_vq(vdev->priv);
6d62c37f
MT
818 if (ret)
819 return ret;
820
821 virtio_device_ready(vdev);
1cf7e9c6 822
6d62c37f
MT
823 blk_mq_start_stopped_hw_queues(vblk->disk->queue, true);
824 return 0;
f8fb5bc2
AS
825}
826#endif
827
47483e25 828static const struct virtio_device_id id_table[] = {
e467cde2
RR
829 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
830 { 0 },
831};
832
19c1c5a6 833static unsigned int features_legacy[] = {
02c42b7a
TH
834 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
835 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
6a27b656
ML
836 VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
837 VIRTIO_BLK_F_MQ,
19c1c5a6
MT
838}
839;
840static unsigned int features[] = {
841 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
842 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE,
53eab6fd 843 VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE,
19c1c5a6 844 VIRTIO_BLK_F_MQ,
c45a6816
RR
845};
846
8d85fce7 847static struct virtio_driver virtio_blk = {
19c1c5a6
MT
848 .feature_table = features,
849 .feature_table_size = ARRAY_SIZE(features),
850 .feature_table_legacy = features_legacy,
851 .feature_table_size_legacy = ARRAY_SIZE(features_legacy),
852 .driver.name = KBUILD_MODNAME,
853 .driver.owner = THIS_MODULE,
854 .id_table = id_table,
855 .probe = virtblk_probe,
856 .remove = virtblk_remove,
857 .config_changed = virtblk_config_changed,
89107000 858#ifdef CONFIG_PM_SLEEP
19c1c5a6
MT
859 .freeze = virtblk_freeze,
860 .restore = virtblk_restore,
f8fb5bc2 861#endif
e467cde2
RR
862};
863
864static int __init init(void)
865{
7a7c924c
CH
866 int error;
867
868 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
869 if (!virtblk_wq)
870 return -ENOMEM;
871
4f3bf19c 872 major = register_blkdev(0, "virtblk");
7a7c924c
CH
873 if (major < 0) {
874 error = major;
875 goto out_destroy_workqueue;
876 }
877
878 error = register_virtio_driver(&virtio_blk);
879 if (error)
880 goto out_unregister_blkdev;
881 return 0;
882
883out_unregister_blkdev:
884 unregister_blkdev(major, "virtblk");
885out_destroy_workqueue:
886 destroy_workqueue(virtblk_wq);
887 return error;
e467cde2
RR
888}
889
890static void __exit fini(void)
891{
892 unregister_virtio_driver(&virtio_blk);
38f37b57 893 unregister_blkdev(major, "virtblk");
7a7c924c 894 destroy_workqueue(virtblk_wq);
e467cde2
RR
895}
896module_init(init);
897module_exit(fini);
898
899MODULE_DEVICE_TABLE(virtio, id_table);
900MODULE_DESCRIPTION("Virtio block driver");
901MODULE_LICENSE("GPL");