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Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
e467cde2 RR |
2 | //#define DEBUG |
3 | #include <linux/spinlock.h> | |
5a0e3ad6 | 4 | #include <linux/slab.h> |
e467cde2 RR |
5 | #include <linux/blkdev.h> |
6 | #include <linux/hdreg.h> | |
0c8d44f2 | 7 | #include <linux/module.h> |
4678d6f9 | 8 | #include <linux/mutex.h> |
ad71473d | 9 | #include <linux/interrupt.h> |
e467cde2 RR |
10 | #include <linux/virtio.h> |
11 | #include <linux/virtio_blk.h> | |
3d1266c7 | 12 | #include <linux/scatterlist.h> |
7a7c924c | 13 | #include <linux/string_helpers.h> |
5087a50e | 14 | #include <linux/idr.h> |
1cf7e9c6 | 15 | #include <linux/blk-mq.h> |
ad71473d | 16 | #include <linux/blk-mq-virtio.h> |
1cf7e9c6 | 17 | #include <linux/numa.h> |
55a2415b | 18 | #include <uapi/linux/virtio_ring.h> |
3d1266c7 | 19 | |
4f3bf19c | 20 | #define PART_BITS 4 |
6a27b656 | 21 | #define VQ_NAME_LEN 16 |
1f23816b | 22 | #define MAX_DISCARD_SEGMENTS 256u |
e467cde2 | 23 | |
5087a50e MT |
24 | static int major; |
25 | static DEFINE_IDA(vd_index_ida); | |
26 | ||
2a647bfe | 27 | static struct workqueue_struct *virtblk_wq; |
4f3bf19c | 28 | |
6a27b656 ML |
29 | struct virtio_blk_vq { |
30 | struct virtqueue *vq; | |
31 | spinlock_t lock; | |
32 | char name[VQ_NAME_LEN]; | |
33 | } ____cacheline_aligned_in_smp; | |
34 | ||
bb6ec576 | 35 | struct virtio_blk { |
e467cde2 | 36 | struct virtio_device *vdev; |
e467cde2 RR |
37 | |
38 | /* The disk structure for the kernel. */ | |
39 | struct gendisk *disk; | |
40 | ||
24d2f903 CH |
41 | /* Block layer tags. */ |
42 | struct blk_mq_tag_set tag_set; | |
43 | ||
7a7c924c CH |
44 | /* Process context for config space updates */ |
45 | struct work_struct config_work; | |
46 | ||
0864b79a RR |
47 | /* What host tells us, plus 2 for header & tailer. */ |
48 | unsigned int sg_elems; | |
49 | ||
5087a50e MT |
50 | /* Ida index - used to track minor number allocations. */ |
51 | int index; | |
6a27b656 ML |
52 | |
53 | /* num of vqs */ | |
54 | int num_vqs; | |
55 | struct virtio_blk_vq *vqs; | |
e467cde2 RR |
56 | }; |
57 | ||
bb6ec576 | 58 | struct virtblk_req { |
97b50a65 | 59 | struct virtio_blk_outhdr out_hdr; |
cb38fa23 | 60 | u8 status; |
a98755c5 | 61 | struct scatterlist sg[]; |
e467cde2 RR |
62 | }; |
63 | ||
2a842aca | 64 | static inline blk_status_t virtblk_result(struct virtblk_req *vbr) |
a98755c5 AH |
65 | { |
66 | switch (vbr->status) { | |
67 | case VIRTIO_BLK_S_OK: | |
2a842aca | 68 | return BLK_STS_OK; |
a98755c5 | 69 | case VIRTIO_BLK_S_UNSUPP: |
2a842aca | 70 | return BLK_STS_NOTSUPP; |
a98755c5 | 71 | default: |
2a842aca | 72 | return BLK_STS_IOERR; |
a98755c5 AH |
73 | } |
74 | } | |
75 | ||
97b50a65 CH |
76 | static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr, |
77 | struct scatterlist *data_sg, bool have_data) | |
78 | { | |
79 | struct scatterlist hdr, status, *sgs[3]; | |
80 | unsigned int num_out = 0, num_in = 0; | |
81 | ||
82 | sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr)); | |
83 | sgs[num_out++] = &hdr; | |
20af3cfd | 84 | |
0a11cc36 | 85 | if (have_data) { |
19c1c5a6 | 86 | if (vbr->out_hdr.type & cpu_to_virtio32(vq->vdev, VIRTIO_BLK_T_OUT)) |
20af3cfd | 87 | sgs[num_out++] = data_sg; |
8f39db9d | 88 | else |
20af3cfd PB |
89 | sgs[num_out + num_in++] = data_sg; |
90 | } | |
91 | ||
8f39db9d PB |
92 | sg_init_one(&status, &vbr->status, sizeof(vbr->status)); |
93 | sgs[num_out + num_in++] = &status; | |
94 | ||
95 | return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC); | |
5ee21a52 PB |
96 | } |
97 | ||
1f23816b CL |
98 | static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap) |
99 | { | |
100 | unsigned short segments = blk_rq_nr_discard_segments(req); | |
101 | unsigned short n = 0; | |
102 | struct virtio_blk_discard_write_zeroes *range; | |
103 | struct bio *bio; | |
104 | u32 flags = 0; | |
105 | ||
106 | if (unmap) | |
107 | flags |= VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP; | |
108 | ||
109 | range = kmalloc_array(segments, sizeof(*range), GFP_ATOMIC); | |
110 | if (!range) | |
111 | return -ENOMEM; | |
112 | ||
113 | __rq_for_each_bio(bio, req) { | |
114 | u64 sector = bio->bi_iter.bi_sector; | |
115 | u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; | |
116 | ||
117 | range[n].flags = cpu_to_le32(flags); | |
118 | range[n].num_sectors = cpu_to_le32(num_sectors); | |
119 | range[n].sector = cpu_to_le64(sector); | |
120 | n++; | |
121 | } | |
122 | ||
123 | req->special_vec.bv_page = virt_to_page(range); | |
124 | req->special_vec.bv_offset = offset_in_page(range); | |
125 | req->special_vec.bv_len = sizeof(*range) * segments; | |
126 | req->rq_flags |= RQF_SPECIAL_PAYLOAD; | |
127 | ||
128 | return 0; | |
129 | } | |
130 | ||
5124c285 | 131 | static inline void virtblk_request_done(struct request *req) |
a98755c5 | 132 | { |
9d74e257 | 133 | struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); |
a98755c5 | 134 | |
1f23816b CL |
135 | if (req->rq_flags & RQF_SPECIAL_PAYLOAD) { |
136 | kfree(page_address(req->special_vec.bv_page) + | |
137 | req->special_vec.bv_offset); | |
138 | } | |
139 | ||
d19633d5 | 140 | blk_mq_end_request(req, virtblk_result(vbr)); |
a98755c5 AH |
141 | } |
142 | ||
143 | static void virtblk_done(struct virtqueue *vq) | |
e467cde2 RR |
144 | { |
145 | struct virtio_blk *vblk = vq->vdev->priv; | |
1cf7e9c6 | 146 | bool req_done = false; |
6a27b656 | 147 | int qid = vq->index; |
e467cde2 | 148 | struct virtblk_req *vbr; |
e467cde2 | 149 | unsigned long flags; |
a98755c5 | 150 | unsigned int len; |
e467cde2 | 151 | |
6a27b656 | 152 | spin_lock_irqsave(&vblk->vqs[qid].lock, flags); |
bb811108 AH |
153 | do { |
154 | virtqueue_disable_cb(vq); | |
6a27b656 | 155 | while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) { |
85dada09 CH |
156 | struct request *req = blk_mq_rq_from_pdu(vbr); |
157 | ||
08e0029a | 158 | blk_mq_complete_request(req); |
1cf7e9c6 | 159 | req_done = true; |
33659ebb | 160 | } |
7f03b17d HG |
161 | if (unlikely(virtqueue_is_broken(vq))) |
162 | break; | |
bb811108 | 163 | } while (!virtqueue_enable_cb(vq)); |
1cf7e9c6 | 164 | |
e467cde2 | 165 | /* In case queue is stopped waiting for more buffers. */ |
a98755c5 | 166 | if (req_done) |
1b4a3258 | 167 | blk_mq_start_stopped_hw_queues(vblk->disk->queue, true); |
6a27b656 | 168 | spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); |
a98755c5 AH |
169 | } |
170 | ||
944e7c87 JA |
171 | static void virtio_commit_rqs(struct blk_mq_hw_ctx *hctx) |
172 | { | |
173 | struct virtio_blk *vblk = hctx->queue->queuedata; | |
174 | struct virtio_blk_vq *vq = &vblk->vqs[hctx->queue_num]; | |
175 | bool kick; | |
176 | ||
177 | spin_lock_irq(&vq->lock); | |
178 | kick = virtqueue_kick_prepare(vq->vq); | |
179 | spin_unlock_irq(&vq->lock); | |
180 | ||
181 | if (kick) | |
182 | virtqueue_notify(vq->vq); | |
183 | } | |
184 | ||
fc17b653 | 185 | static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx, |
74c45052 | 186 | const struct blk_mq_queue_data *bd) |
e467cde2 | 187 | { |
1cf7e9c6 | 188 | struct virtio_blk *vblk = hctx->queue->queuedata; |
74c45052 | 189 | struct request *req = bd->rq; |
9d74e257 | 190 | struct virtblk_req *vbr = blk_mq_rq_to_pdu(req); |
1cf7e9c6 | 191 | unsigned long flags; |
20af3cfd | 192 | unsigned int num; |
6a27b656 | 193 | int qid = hctx->queue_num; |
5261b85e | 194 | int err; |
e8edca6f | 195 | bool notify = false; |
1f23816b | 196 | bool unmap = false; |
aebf526b | 197 | u32 type; |
e467cde2 | 198 | |
1cf7e9c6 | 199 | BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems); |
e467cde2 | 200 | |
aebf526b CH |
201 | switch (req_op(req)) { |
202 | case REQ_OP_READ: | |
203 | case REQ_OP_WRITE: | |
204 | type = 0; | |
205 | break; | |
206 | case REQ_OP_FLUSH: | |
207 | type = VIRTIO_BLK_T_FLUSH; | |
208 | break; | |
1f23816b CL |
209 | case REQ_OP_DISCARD: |
210 | type = VIRTIO_BLK_T_DISCARD; | |
211 | break; | |
212 | case REQ_OP_WRITE_ZEROES: | |
213 | type = VIRTIO_BLK_T_WRITE_ZEROES; | |
214 | unmap = !(req->cmd_flags & REQ_NOUNMAP); | |
215 | break; | |
aebf526b CH |
216 | case REQ_OP_DRV_IN: |
217 | type = VIRTIO_BLK_T_GET_ID; | |
218 | break; | |
219 | default: | |
220 | WARN_ON_ONCE(1); | |
fc17b653 | 221 | return BLK_STS_IOERR; |
e467cde2 RR |
222 | } |
223 | ||
aebf526b CH |
224 | vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, type); |
225 | vbr->out_hdr.sector = type ? | |
226 | 0 : cpu_to_virtio64(vblk->vdev, blk_rq_pos(req)); | |
227 | vbr->out_hdr.ioprio = cpu_to_virtio32(vblk->vdev, req_get_ioprio(req)); | |
228 | ||
e2490073 CH |
229 | blk_mq_start_request(req); |
230 | ||
1f23816b CL |
231 | if (type == VIRTIO_BLK_T_DISCARD || type == VIRTIO_BLK_T_WRITE_ZEROES) { |
232 | err = virtblk_setup_discard_write_zeroes(req, unmap); | |
233 | if (err) | |
234 | return BLK_STS_RESOURCE; | |
235 | } | |
236 | ||
85dada09 | 237 | num = blk_rq_map_sg(hctx->queue, req, vbr->sg); |
1cde26f9 | 238 | if (num) { |
85dada09 | 239 | if (rq_data_dir(req) == WRITE) |
19c1c5a6 | 240 | vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_OUT); |
20af3cfd | 241 | else |
19c1c5a6 | 242 | vbr->out_hdr.type |= cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_IN); |
e467cde2 RR |
243 | } |
244 | ||
6a27b656 | 245 | spin_lock_irqsave(&vblk->vqs[qid].lock, flags); |
782e067d | 246 | err = virtblk_add_req(vblk->vqs[qid].vq, vbr, vbr->sg, num); |
5261b85e | 247 | if (err) { |
6a27b656 | 248 | virtqueue_kick(vblk->vqs[qid].vq); |
f5f6b95c HP |
249 | /* Don't stop the queue if -ENOMEM: we may have failed to |
250 | * bounce the buffer due to global resource outage. | |
251 | */ | |
252 | if (err == -ENOSPC) | |
253 | blk_mq_stop_hw_queue(hctx); | |
6a27b656 | 254 | spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); |
3d973b2e HP |
255 | switch (err) { |
256 | case -ENOSPC: | |
86ff7c2a | 257 | return BLK_STS_DEV_RESOURCE; |
3d973b2e HP |
258 | case -ENOMEM: |
259 | return BLK_STS_RESOURCE; | |
260 | default: | |
261 | return BLK_STS_IOERR; | |
262 | } | |
a98755c5 AH |
263 | } |
264 | ||
74c45052 | 265 | if (bd->last && virtqueue_kick_prepare(vblk->vqs[qid].vq)) |
e8edca6f | 266 | notify = true; |
6a27b656 | 267 | spin_unlock_irqrestore(&vblk->vqs[qid].lock, flags); |
e8edca6f ML |
268 | |
269 | if (notify) | |
6a27b656 | 270 | virtqueue_notify(vblk->vqs[qid].vq); |
fc17b653 | 271 | return BLK_STS_OK; |
a98755c5 AH |
272 | } |
273 | ||
4cb2ea28 | 274 | /* return id (s/n) string for *disk to *id_str |
275 | */ | |
276 | static int virtblk_get_id(struct gendisk *disk, char *id_str) | |
277 | { | |
278 | struct virtio_blk *vblk = disk->private_data; | |
f9596695 | 279 | struct request_queue *q = vblk->disk->queue; |
4cb2ea28 | 280 | struct request *req; |
e4c4776d | 281 | int err; |
4cb2ea28 | 282 | |
ff005a06 | 283 | req = blk_get_request(q, REQ_OP_DRV_IN, 0); |
f9596695 | 284 | if (IS_ERR(req)) |
4cb2ea28 | 285 | return PTR_ERR(req); |
f9596695 CH |
286 | |
287 | err = blk_rq_map_kern(q, req, id_str, VIRTIO_BLK_ID_BYTES, GFP_KERNEL); | |
288 | if (err) | |
289 | goto out; | |
290 | ||
b7819b92 | 291 | blk_execute_rq(vblk->disk->queue, vblk->disk, req, false); |
2a842aca | 292 | err = blk_status_to_errno(virtblk_result(blk_mq_rq_to_pdu(req))); |
f9596695 | 293 | out: |
e4c4776d | 294 | blk_put_request(req); |
e4c4776d | 295 | return err; |
4cb2ea28 | 296 | } |
297 | ||
135da0b0 CB |
298 | /* We provide getgeo only to please some old bootloader/partitioning tools */ |
299 | static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo) | |
300 | { | |
48e4043d | 301 | struct virtio_blk *vblk = bd->bd_disk->private_data; |
48e4043d RH |
302 | |
303 | /* see if the host passed in geometry config */ | |
855e0c52 RR |
304 | if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) { |
305 | virtio_cread(vblk->vdev, struct virtio_blk_config, | |
306 | geometry.cylinders, &geo->cylinders); | |
307 | virtio_cread(vblk->vdev, struct virtio_blk_config, | |
308 | geometry.heads, &geo->heads); | |
309 | virtio_cread(vblk->vdev, struct virtio_blk_config, | |
310 | geometry.sectors, &geo->sectors); | |
48e4043d RH |
311 | } else { |
312 | /* some standard values, similar to sd */ | |
313 | geo->heads = 1 << 6; | |
314 | geo->sectors = 1 << 5; | |
315 | geo->cylinders = get_capacity(bd->bd_disk) >> 11; | |
316 | } | |
135da0b0 CB |
317 | return 0; |
318 | } | |
319 | ||
83d5cde4 | 320 | static const struct block_device_operations virtblk_fops = { |
135da0b0 CB |
321 | .owner = THIS_MODULE, |
322 | .getgeo = virtblk_getgeo, | |
e467cde2 RR |
323 | }; |
324 | ||
d50ed907 CB |
325 | static int index_to_minor(int index) |
326 | { | |
327 | return index << PART_BITS; | |
328 | } | |
329 | ||
5087a50e MT |
330 | static int minor_to_index(int minor) |
331 | { | |
332 | return minor >> PART_BITS; | |
333 | } | |
334 | ||
e982c4d0 HR |
335 | static ssize_t serial_show(struct device *dev, |
336 | struct device_attribute *attr, char *buf) | |
a5eb9e4f RH |
337 | { |
338 | struct gendisk *disk = dev_to_disk(dev); | |
339 | int err; | |
340 | ||
341 | /* sysfs gives us a PAGE_SIZE buffer */ | |
342 | BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES); | |
343 | ||
344 | buf[VIRTIO_BLK_ID_BYTES] = '\0'; | |
345 | err = virtblk_get_id(disk, buf); | |
346 | if (!err) | |
347 | return strlen(buf); | |
348 | ||
349 | if (err == -EIO) /* Unsupported? Make it empty. */ | |
350 | return 0; | |
351 | ||
352 | return err; | |
353 | } | |
393c525b | 354 | |
e982c4d0 | 355 | static DEVICE_ATTR_RO(serial); |
a5eb9e4f | 356 | |
daf2a501 SH |
357 | /* The queue's logical block size must be set before calling this */ |
358 | static void virtblk_update_capacity(struct virtio_blk *vblk, bool resize) | |
7a7c924c | 359 | { |
7a7c924c CH |
360 | struct virtio_device *vdev = vblk->vdev; |
361 | struct request_queue *q = vblk->disk->queue; | |
362 | char cap_str_2[10], cap_str_10[10]; | |
1046d304 | 363 | unsigned long long nblocks; |
b9f28d86 | 364 | u64 capacity; |
7a7c924c CH |
365 | |
366 | /* Host must always specify the capacity. */ | |
855e0c52 | 367 | virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity); |
7a7c924c CH |
368 | |
369 | /* If capacity is too big, truncate with warning. */ | |
370 | if ((sector_t)capacity != capacity) { | |
371 | dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n", | |
372 | (unsigned long long)capacity); | |
373 | capacity = (sector_t)-1; | |
374 | } | |
375 | ||
1046d304 SH |
376 | nblocks = DIV_ROUND_UP_ULL(capacity, queue_logical_block_size(q) >> 9); |
377 | ||
378 | string_get_size(nblocks, queue_logical_block_size(q), | |
b9f28d86 | 379 | STRING_UNITS_2, cap_str_2, sizeof(cap_str_2)); |
1046d304 | 380 | string_get_size(nblocks, queue_logical_block_size(q), |
b9f28d86 | 381 | STRING_UNITS_10, cap_str_10, sizeof(cap_str_10)); |
7a7c924c CH |
382 | |
383 | dev_notice(&vdev->dev, | |
daf2a501 SH |
384 | "[%s] %s%llu %d-byte logical blocks (%s/%s)\n", |
385 | vblk->disk->disk_name, | |
386 | resize ? "new size: " : "", | |
1046d304 SH |
387 | nblocks, |
388 | queue_logical_block_size(q), | |
389 | cap_str_10, | |
390 | cap_str_2); | |
7a7c924c | 391 | |
662155e2 | 392 | set_capacity_revalidate_and_notify(vblk->disk, capacity, true); |
daf2a501 SH |
393 | } |
394 | ||
395 | static void virtblk_config_changed_work(struct work_struct *work) | |
396 | { | |
397 | struct virtio_blk *vblk = | |
398 | container_of(work, struct virtio_blk, config_work); | |
daf2a501 SH |
399 | |
400 | virtblk_update_capacity(vblk, true); | |
7a7c924c CH |
401 | } |
402 | ||
403 | static void virtblk_config_changed(struct virtio_device *vdev) | |
404 | { | |
405 | struct virtio_blk *vblk = vdev->priv; | |
406 | ||
407 | queue_work(virtblk_wq, &vblk->config_work); | |
408 | } | |
409 | ||
6abd6e5a AS |
410 | static int init_vq(struct virtio_blk *vblk) |
411 | { | |
2ff98449 | 412 | int err; |
6a27b656 ML |
413 | int i; |
414 | vq_callback_t **callbacks; | |
415 | const char **names; | |
416 | struct virtqueue **vqs; | |
417 | unsigned short num_vqs; | |
418 | struct virtio_device *vdev = vblk->vdev; | |
ad71473d | 419 | struct irq_affinity desc = { 0, }; |
6a27b656 ML |
420 | |
421 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_MQ, | |
422 | struct virtio_blk_config, num_queues, | |
423 | &num_vqs); | |
424 | if (err) | |
425 | num_vqs = 1; | |
426 | ||
bf348f9b DZ |
427 | num_vqs = min_t(unsigned int, nr_cpu_ids, num_vqs); |
428 | ||
668866b6 | 429 | vblk->vqs = kmalloc_array(num_vqs, sizeof(*vblk->vqs), GFP_KERNEL); |
347a5293 MH |
430 | if (!vblk->vqs) |
431 | return -ENOMEM; | |
6a27b656 | 432 | |
668866b6 ME |
433 | names = kmalloc_array(num_vqs, sizeof(*names), GFP_KERNEL); |
434 | callbacks = kmalloc_array(num_vqs, sizeof(*callbacks), GFP_KERNEL); | |
435 | vqs = kmalloc_array(num_vqs, sizeof(*vqs), GFP_KERNEL); | |
347a5293 MH |
436 | if (!names || !callbacks || !vqs) { |
437 | err = -ENOMEM; | |
438 | goto out; | |
439 | } | |
6abd6e5a | 440 | |
6a27b656 ML |
441 | for (i = 0; i < num_vqs; i++) { |
442 | callbacks[i] = virtblk_done; | |
443 | snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i); | |
444 | names[i] = vblk->vqs[i].name; | |
445 | } | |
446 | ||
447 | /* Discover virtqueues and write information to configuration. */ | |
9b2bbdb2 | 448 | err = virtio_find_vqs(vdev, num_vqs, vqs, callbacks, names, &desc); |
6a27b656 | 449 | if (err) |
347a5293 | 450 | goto out; |
6abd6e5a | 451 | |
6a27b656 ML |
452 | for (i = 0; i < num_vqs; i++) { |
453 | spin_lock_init(&vblk->vqs[i].lock); | |
454 | vblk->vqs[i].vq = vqs[i]; | |
455 | } | |
456 | vblk->num_vqs = num_vqs; | |
457 | ||
347a5293 | 458 | out: |
6a27b656 | 459 | kfree(vqs); |
6a27b656 | 460 | kfree(callbacks); |
6a27b656 | 461 | kfree(names); |
6a27b656 ML |
462 | if (err) |
463 | kfree(vblk->vqs); | |
6abd6e5a AS |
464 | return err; |
465 | } | |
466 | ||
c0aa3e09 RM |
467 | /* |
468 | * Legacy naming scheme used for virtio devices. We are stuck with it for | |
469 | * virtio blk but don't ever use it for any new driver. | |
470 | */ | |
471 | static int virtblk_name_format(char *prefix, int index, char *buf, int buflen) | |
472 | { | |
473 | const int base = 'z' - 'a' + 1; | |
474 | char *begin = buf + strlen(prefix); | |
475 | char *end = buf + buflen; | |
476 | char *p; | |
477 | int unit; | |
478 | ||
479 | p = end - 1; | |
480 | *p = '\0'; | |
481 | unit = base; | |
482 | do { | |
483 | if (p == begin) | |
484 | return -EINVAL; | |
485 | *--p = 'a' + (index % unit); | |
486 | index = (index / unit) - 1; | |
487 | } while (index >= 0); | |
488 | ||
489 | memmove(begin, p, end - p); | |
490 | memcpy(buf, prefix, strlen(prefix)); | |
491 | ||
492 | return 0; | |
493 | } | |
494 | ||
cd5d5038 PB |
495 | static int virtblk_get_cache_mode(struct virtio_device *vdev) |
496 | { | |
497 | u8 writeback; | |
498 | int err; | |
499 | ||
855e0c52 RR |
500 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE, |
501 | struct virtio_blk_config, wce, | |
502 | &writeback); | |
592002f5 MT |
503 | |
504 | /* | |
505 | * If WCE is not configurable and flush is not available, | |
506 | * assume no writeback cache is in use. | |
507 | */ | |
cd5d5038 | 508 | if (err) |
592002f5 | 509 | writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH); |
cd5d5038 PB |
510 | |
511 | return writeback; | |
512 | } | |
513 | ||
514 | static void virtblk_update_cache_mode(struct virtio_device *vdev) | |
515 | { | |
516 | u8 writeback = virtblk_get_cache_mode(vdev); | |
517 | struct virtio_blk *vblk = vdev->priv; | |
518 | ||
ad9126ac | 519 | blk_queue_write_cache(vblk->disk->queue, writeback, false); |
cd5d5038 PB |
520 | revalidate_disk(vblk->disk); |
521 | } | |
522 | ||
523 | static const char *const virtblk_cache_types[] = { | |
524 | "write through", "write back" | |
525 | }; | |
526 | ||
527 | static ssize_t | |
e982c4d0 HR |
528 | cache_type_store(struct device *dev, struct device_attribute *attr, |
529 | const char *buf, size_t count) | |
cd5d5038 PB |
530 | { |
531 | struct gendisk *disk = dev_to_disk(dev); | |
532 | struct virtio_blk *vblk = disk->private_data; | |
533 | struct virtio_device *vdev = vblk->vdev; | |
534 | int i; | |
cd5d5038 PB |
535 | |
536 | BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE)); | |
f53d5aa0 | 537 | i = sysfs_match_string(virtblk_cache_types, buf); |
cd5d5038 | 538 | if (i < 0) |
f53d5aa0 | 539 | return i; |
cd5d5038 | 540 | |
855e0c52 | 541 | virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i); |
cd5d5038 PB |
542 | virtblk_update_cache_mode(vdev); |
543 | return count; | |
544 | } | |
545 | ||
546 | static ssize_t | |
e982c4d0 | 547 | cache_type_show(struct device *dev, struct device_attribute *attr, char *buf) |
cd5d5038 PB |
548 | { |
549 | struct gendisk *disk = dev_to_disk(dev); | |
550 | struct virtio_blk *vblk = disk->private_data; | |
551 | u8 writeback = virtblk_get_cache_mode(vblk->vdev); | |
552 | ||
553 | BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types)); | |
554 | return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]); | |
555 | } | |
556 | ||
e982c4d0 HR |
557 | static DEVICE_ATTR_RW(cache_type); |
558 | ||
559 | static struct attribute *virtblk_attrs[] = { | |
560 | &dev_attr_serial.attr, | |
561 | &dev_attr_cache_type.attr, | |
562 | NULL, | |
563 | }; | |
564 | ||
565 | static umode_t virtblk_attrs_are_visible(struct kobject *kobj, | |
566 | struct attribute *a, int n) | |
567 | { | |
568 | struct device *dev = container_of(kobj, struct device, kobj); | |
569 | struct gendisk *disk = dev_to_disk(dev); | |
570 | struct virtio_blk *vblk = disk->private_data; | |
571 | struct virtio_device *vdev = vblk->vdev; | |
572 | ||
573 | if (a == &dev_attr_cache_type.attr && | |
574 | !virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE)) | |
575 | return S_IRUGO; | |
576 | ||
577 | return a->mode; | |
578 | } | |
579 | ||
580 | static const struct attribute_group virtblk_attr_group = { | |
581 | .attrs = virtblk_attrs, | |
582 | .is_visible = virtblk_attrs_are_visible, | |
583 | }; | |
584 | ||
585 | static const struct attribute_group *virtblk_attr_groups[] = { | |
586 | &virtblk_attr_group, | |
587 | NULL, | |
588 | }; | |
cd5d5038 | 589 | |
d6296d39 CH |
590 | static int virtblk_init_request(struct blk_mq_tag_set *set, struct request *rq, |
591 | unsigned int hctx_idx, unsigned int numa_node) | |
e9b267d9 | 592 | { |
d6296d39 | 593 | struct virtio_blk *vblk = set->driver_data; |
e9b267d9 CH |
594 | struct virtblk_req *vbr = blk_mq_rq_to_pdu(rq); |
595 | ||
596 | sg_init_table(vbr->sg, vblk->sg_elems); | |
597 | return 0; | |
598 | } | |
599 | ||
ad71473d CH |
600 | static int virtblk_map_queues(struct blk_mq_tag_set *set) |
601 | { | |
602 | struct virtio_blk *vblk = set->driver_data; | |
603 | ||
9bc00750 DZ |
604 | return blk_mq_virtio_map_queues(&set->map[HCTX_TYPE_DEFAULT], |
605 | vblk->vdev, 0); | |
ad71473d CH |
606 | } |
607 | ||
f363b089 | 608 | static const struct blk_mq_ops virtio_mq_ops = { |
1cf7e9c6 | 609 | .queue_rq = virtio_queue_rq, |
944e7c87 | 610 | .commit_rqs = virtio_commit_rqs, |
5124c285 | 611 | .complete = virtblk_request_done, |
24d2f903 | 612 | .init_request = virtblk_init_request, |
ad71473d | 613 | .map_queues = virtblk_map_queues, |
1cf7e9c6 JA |
614 | }; |
615 | ||
24d2f903 CH |
616 | static unsigned int virtblk_queue_depth; |
617 | module_param_named(queue_depth, virtblk_queue_depth, uint, 0444); | |
1cf7e9c6 | 618 | |
8d85fce7 | 619 | static int virtblk_probe(struct virtio_device *vdev) |
e467cde2 RR |
620 | { |
621 | struct virtio_blk *vblk; | |
69740c8b | 622 | struct request_queue *q; |
5087a50e | 623 | int err, index; |
a98755c5 | 624 | |
fd1068e1 | 625 | u32 v, blk_size, max_size, sg_elems, opt_io_size; |
69740c8b CH |
626 | u16 min_io_size; |
627 | u8 physical_block_exp, alignment_offset; | |
e467cde2 | 628 | |
a4379fd8 MT |
629 | if (!vdev->config->get) { |
630 | dev_err(&vdev->dev, "%s failure: config access disabled\n", | |
631 | __func__); | |
632 | return -EINVAL; | |
633 | } | |
634 | ||
5087a50e MT |
635 | err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS), |
636 | GFP_KERNEL); | |
637 | if (err < 0) | |
638 | goto out; | |
639 | index = err; | |
4f3bf19c | 640 | |
0864b79a | 641 | /* We need to know how many segments before we allocate. */ |
855e0c52 RR |
642 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX, |
643 | struct virtio_blk_config, seg_max, | |
644 | &sg_elems); | |
a5b365a6 CH |
645 | |
646 | /* We need at least one SG element, whatever they say. */ | |
647 | if (err || !sg_elems) | |
0864b79a RR |
648 | sg_elems = 1; |
649 | ||
650 | /* We need an extra sg elements at head and tail. */ | |
651 | sg_elems += 2; | |
1cf7e9c6 | 652 | vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL); |
e467cde2 RR |
653 | if (!vblk) { |
654 | err = -ENOMEM; | |
5087a50e | 655 | goto out_free_index; |
e467cde2 RR |
656 | } |
657 | ||
e467cde2 | 658 | vblk->vdev = vdev; |
0864b79a | 659 | vblk->sg_elems = sg_elems; |
a98755c5 | 660 | |
7a7c924c | 661 | INIT_WORK(&vblk->config_work, virtblk_config_changed_work); |
e467cde2 | 662 | |
6abd6e5a AS |
663 | err = init_vq(vblk); |
664 | if (err) | |
e467cde2 | 665 | goto out_free_vblk; |
e467cde2 | 666 | |
e467cde2 | 667 | /* FIXME: How many partitions? How long is a piece of string? */ |
4f3bf19c | 668 | vblk->disk = alloc_disk(1 << PART_BITS); |
e467cde2 RR |
669 | if (!vblk->disk) { |
670 | err = -ENOMEM; | |
1cf7e9c6 | 671 | goto out_free_vq; |
e467cde2 RR |
672 | } |
673 | ||
fc4324b4 | 674 | /* Default queue sizing is to fill the ring. */ |
24d2f903 | 675 | if (!virtblk_queue_depth) { |
6a27b656 | 676 | virtblk_queue_depth = vblk->vqs[0].vq->num_free; |
fc4324b4 RR |
677 | /* ... but without indirect descs, we use 2 descs per req */ |
678 | if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC)) | |
24d2f903 | 679 | virtblk_queue_depth /= 2; |
fc4324b4 | 680 | } |
24d2f903 CH |
681 | |
682 | memset(&vblk->tag_set, 0, sizeof(vblk->tag_set)); | |
683 | vblk->tag_set.ops = &virtio_mq_ops; | |
24d2f903 CH |
684 | vblk->tag_set.queue_depth = virtblk_queue_depth; |
685 | vblk->tag_set.numa_node = NUMA_NO_NODE; | |
686 | vblk->tag_set.flags = BLK_MQ_F_SHOULD_MERGE; | |
687 | vblk->tag_set.cmd_size = | |
1cf7e9c6 JA |
688 | sizeof(struct virtblk_req) + |
689 | sizeof(struct scatterlist) * sg_elems; | |
24d2f903 | 690 | vblk->tag_set.driver_data = vblk; |
6a27b656 | 691 | vblk->tag_set.nr_hw_queues = vblk->num_vqs; |
1cf7e9c6 | 692 | |
24d2f903 CH |
693 | err = blk_mq_alloc_tag_set(&vblk->tag_set); |
694 | if (err) | |
695 | goto out_put_disk; | |
696 | ||
6bf6b0aa | 697 | q = blk_mq_init_queue(&vblk->tag_set); |
35b489d3 | 698 | if (IS_ERR(q)) { |
e467cde2 | 699 | err = -ENOMEM; |
24d2f903 | 700 | goto out_free_tags; |
e467cde2 | 701 | } |
6bf6b0aa | 702 | vblk->disk->queue = q; |
e467cde2 | 703 | |
69740c8b | 704 | q->queuedata = vblk; |
7d116b62 | 705 | |
c0aa3e09 | 706 | virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN); |
d50ed907 | 707 | |
e467cde2 | 708 | vblk->disk->major = major; |
d50ed907 | 709 | vblk->disk->first_minor = index_to_minor(index); |
e467cde2 RR |
710 | vblk->disk->private_data = vblk; |
711 | vblk->disk->fops = &virtblk_fops; | |
5fa3142d | 712 | vblk->disk->flags |= GENHD_FL_EXT_DEVT; |
5087a50e | 713 | vblk->index = index; |
4f3bf19c | 714 | |
02c42b7a | 715 | /* configure queue flush support */ |
cd5d5038 | 716 | virtblk_update_cache_mode(vdev); |
e467cde2 | 717 | |
3ef53609 CB |
718 | /* If disk is read-only in the host, the guest should obey */ |
719 | if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO)) | |
720 | set_disk_ro(vblk->disk, 1); | |
721 | ||
0864b79a | 722 | /* We can handle whatever the host told us to handle. */ |
ee714f2d | 723 | blk_queue_max_segments(q, vblk->sg_elems-2); |
0864b79a | 724 | |
4b7f7e20 | 725 | /* No real sector limit. */ |
ee714f2d | 726 | blk_queue_max_hw_sectors(q, -1U); |
4b7f7e20 | 727 | |
fd1068e1 JR |
728 | max_size = virtio_max_dma_size(vdev); |
729 | ||
a586d4f6 RR |
730 | /* Host can optionally specify maximum segment size and number of |
731 | * segments. */ | |
855e0c52 RR |
732 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX, |
733 | struct virtio_blk_config, size_max, &v); | |
e467cde2 | 734 | if (!err) |
fd1068e1 JR |
735 | max_size = min(max_size, v); |
736 | ||
737 | blk_queue_max_segment_size(q, max_size); | |
e467cde2 | 738 | |
066f4d82 | 739 | /* Host can optionally specify the block size of the device */ |
855e0c52 RR |
740 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, |
741 | struct virtio_blk_config, blk_size, | |
742 | &blk_size); | |
066f4d82 | 743 | if (!err) |
69740c8b CH |
744 | blk_queue_logical_block_size(q, blk_size); |
745 | else | |
746 | blk_size = queue_logical_block_size(q); | |
747 | ||
748 | /* Use topology information if available */ | |
855e0c52 RR |
749 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, |
750 | struct virtio_blk_config, physical_block_exp, | |
751 | &physical_block_exp); | |
69740c8b CH |
752 | if (!err && physical_block_exp) |
753 | blk_queue_physical_block_size(q, | |
754 | blk_size * (1 << physical_block_exp)); | |
755 | ||
855e0c52 RR |
756 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, |
757 | struct virtio_blk_config, alignment_offset, | |
758 | &alignment_offset); | |
69740c8b CH |
759 | if (!err && alignment_offset) |
760 | blk_queue_alignment_offset(q, blk_size * alignment_offset); | |
761 | ||
855e0c52 RR |
762 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, |
763 | struct virtio_blk_config, min_io_size, | |
764 | &min_io_size); | |
69740c8b CH |
765 | if (!err && min_io_size) |
766 | blk_queue_io_min(q, blk_size * min_io_size); | |
767 | ||
855e0c52 RR |
768 | err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY, |
769 | struct virtio_blk_config, opt_io_size, | |
770 | &opt_io_size); | |
69740c8b CH |
771 | if (!err && opt_io_size) |
772 | blk_queue_io_opt(q, blk_size * opt_io_size); | |
773 | ||
1f23816b CL |
774 | if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { |
775 | q->limits.discard_granularity = blk_size; | |
776 | ||
777 | virtio_cread(vdev, struct virtio_blk_config, | |
778 | discard_sector_alignment, &v); | |
779 | q->limits.discard_alignment = v ? v << SECTOR_SHIFT : 0; | |
780 | ||
781 | virtio_cread(vdev, struct virtio_blk_config, | |
782 | max_discard_sectors, &v); | |
783 | blk_queue_max_discard_sectors(q, v ? v : UINT_MAX); | |
784 | ||
785 | virtio_cread(vdev, struct virtio_blk_config, max_discard_seg, | |
786 | &v); | |
787 | blk_queue_max_discard_segments(q, | |
788 | min_not_zero(v, | |
789 | MAX_DISCARD_SEGMENTS)); | |
790 | ||
791 | blk_queue_flag_set(QUEUE_FLAG_DISCARD, q); | |
792 | } | |
793 | ||
794 | if (virtio_has_feature(vdev, VIRTIO_BLK_F_WRITE_ZEROES)) { | |
795 | virtio_cread(vdev, struct virtio_blk_config, | |
796 | max_write_zeroes_sectors, &v); | |
797 | blk_queue_max_write_zeroes_sectors(q, v ? v : UINT_MAX); | |
798 | } | |
799 | ||
daf2a501 | 800 | virtblk_update_capacity(vblk, false); |
7a11370e MT |
801 | virtio_device_ready(vdev); |
802 | ||
e982c4d0 | 803 | device_add_disk(&vdev->dev, vblk->disk, virtblk_attr_groups); |
e467cde2 RR |
804 | return 0; |
805 | ||
24d2f903 CH |
806 | out_free_tags: |
807 | blk_mq_free_tag_set(&vblk->tag_set); | |
e467cde2 RR |
808 | out_put_disk: |
809 | put_disk(vblk->disk); | |
e467cde2 | 810 | out_free_vq: |
d2a7ddda | 811 | vdev->config->del_vqs(vdev); |
e467cde2 RR |
812 | out_free_vblk: |
813 | kfree(vblk); | |
5087a50e MT |
814 | out_free_index: |
815 | ida_simple_remove(&vd_index_ida, index); | |
e467cde2 RR |
816 | out: |
817 | return err; | |
818 | } | |
819 | ||
8d85fce7 | 820 | static void virtblk_remove(struct virtio_device *vdev) |
e467cde2 RR |
821 | { |
822 | struct virtio_blk *vblk = vdev->priv; | |
5087a50e | 823 | int index = vblk->index; |
f4953fe6 | 824 | int refc; |
e467cde2 | 825 | |
cc74f719 MT |
826 | /* Make sure no work handler is accessing the device. */ |
827 | flush_work(&vblk->config_work); | |
7a7c924c | 828 | |
02e2b124 | 829 | del_gendisk(vblk->disk); |
483001c7 | 830 | blk_cleanup_queue(vblk->disk->queue); |
02e2b124 | 831 | |
24d2f903 CH |
832 | blk_mq_free_tag_set(&vblk->tag_set); |
833 | ||
6e5aa7ef RR |
834 | /* Stop all the virtqueues. */ |
835 | vdev->config->reset(vdev); | |
836 | ||
2c935bc5 | 837 | refc = kref_read(&disk_to_dev(vblk->disk)->kobj.kref); |
e467cde2 | 838 | put_disk(vblk->disk); |
d2a7ddda | 839 | vdev->config->del_vqs(vdev); |
6a27b656 | 840 | kfree(vblk->vqs); |
e467cde2 | 841 | kfree(vblk); |
f4953fe6 AG |
842 | |
843 | /* Only free device id if we don't have any users */ | |
844 | if (refc == 1) | |
845 | ida_simple_remove(&vd_index_ida, index); | |
e467cde2 RR |
846 | } |
847 | ||
89107000 | 848 | #ifdef CONFIG_PM_SLEEP |
f8fb5bc2 AS |
849 | static int virtblk_freeze(struct virtio_device *vdev) |
850 | { | |
851 | struct virtio_blk *vblk = vdev->priv; | |
852 | ||
853 | /* Ensure we don't receive any more interrupts */ | |
854 | vdev->config->reset(vdev); | |
855 | ||
cc74f719 | 856 | /* Make sure no work handler is accessing the device. */ |
f8fb5bc2 AS |
857 | flush_work(&vblk->config_work); |
858 | ||
9b3e9905 | 859 | blk_mq_quiesce_queue(vblk->disk->queue); |
f8fb5bc2 AS |
860 | |
861 | vdev->config->del_vqs(vdev); | |
862 | return 0; | |
863 | } | |
864 | ||
865 | static int virtblk_restore(struct virtio_device *vdev) | |
866 | { | |
867 | struct virtio_blk *vblk = vdev->priv; | |
868 | int ret; | |
869 | ||
f8fb5bc2 | 870 | ret = init_vq(vdev->priv); |
6d62c37f MT |
871 | if (ret) |
872 | return ret; | |
873 | ||
874 | virtio_device_ready(vdev); | |
1cf7e9c6 | 875 | |
9b3e9905 | 876 | blk_mq_unquiesce_queue(vblk->disk->queue); |
6d62c37f | 877 | return 0; |
f8fb5bc2 AS |
878 | } |
879 | #endif | |
880 | ||
47483e25 | 881 | static const struct virtio_device_id id_table[] = { |
e467cde2 RR |
882 | { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID }, |
883 | { 0 }, | |
884 | }; | |
885 | ||
19c1c5a6 | 886 | static unsigned int features_legacy[] = { |
02c42b7a | 887 | VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, |
97b50a65 | 888 | VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, |
592002f5 | 889 | VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, |
1f23816b | 890 | VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, |
19c1c5a6 MT |
891 | } |
892 | ; | |
893 | static unsigned int features[] = { | |
894 | VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY, | |
895 | VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, | |
592002f5 | 896 | VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE, |
1f23816b | 897 | VIRTIO_BLK_F_MQ, VIRTIO_BLK_F_DISCARD, VIRTIO_BLK_F_WRITE_ZEROES, |
c45a6816 RR |
898 | }; |
899 | ||
8d85fce7 | 900 | static struct virtio_driver virtio_blk = { |
19c1c5a6 MT |
901 | .feature_table = features, |
902 | .feature_table_size = ARRAY_SIZE(features), | |
903 | .feature_table_legacy = features_legacy, | |
904 | .feature_table_size_legacy = ARRAY_SIZE(features_legacy), | |
905 | .driver.name = KBUILD_MODNAME, | |
906 | .driver.owner = THIS_MODULE, | |
907 | .id_table = id_table, | |
908 | .probe = virtblk_probe, | |
909 | .remove = virtblk_remove, | |
910 | .config_changed = virtblk_config_changed, | |
89107000 | 911 | #ifdef CONFIG_PM_SLEEP |
19c1c5a6 MT |
912 | .freeze = virtblk_freeze, |
913 | .restore = virtblk_restore, | |
f8fb5bc2 | 914 | #endif |
e467cde2 RR |
915 | }; |
916 | ||
917 | static int __init init(void) | |
918 | { | |
7a7c924c CH |
919 | int error; |
920 | ||
921 | virtblk_wq = alloc_workqueue("virtio-blk", 0, 0); | |
922 | if (!virtblk_wq) | |
923 | return -ENOMEM; | |
924 | ||
4f3bf19c | 925 | major = register_blkdev(0, "virtblk"); |
7a7c924c CH |
926 | if (major < 0) { |
927 | error = major; | |
928 | goto out_destroy_workqueue; | |
929 | } | |
930 | ||
931 | error = register_virtio_driver(&virtio_blk); | |
932 | if (error) | |
933 | goto out_unregister_blkdev; | |
934 | return 0; | |
935 | ||
936 | out_unregister_blkdev: | |
937 | unregister_blkdev(major, "virtblk"); | |
938 | out_destroy_workqueue: | |
939 | destroy_workqueue(virtblk_wq); | |
940 | return error; | |
e467cde2 RR |
941 | } |
942 | ||
943 | static void __exit fini(void) | |
944 | { | |
945 | unregister_virtio_driver(&virtio_blk); | |
38f37b57 | 946 | unregister_blkdev(major, "virtblk"); |
7a7c924c | 947 | destroy_workqueue(virtblk_wq); |
e467cde2 RR |
948 | } |
949 | module_init(init); | |
950 | module_exit(fini); | |
951 | ||
952 | MODULE_DEVICE_TABLE(virtio, id_table); | |
953 | MODULE_DESCRIPTION("Virtio block driver"); | |
954 | MODULE_LICENSE("GPL"); |