blob: 6d8a87f252de563f1251872e5bccbd25e2e64cf7 [file] [log] [blame]
Rusty Russelle467cde2007-10-22 11:03:38 +10001//#define DEBUG
2#include <linux/spinlock.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09003#include <linux/slab.h>
Rusty Russelle467cde2007-10-22 11:03:38 +10004#include <linux/blkdev.h>
5#include <linux/hdreg.h>
Paul Gortmaker0c8d44f2011-07-01 15:56:05 -04006#include <linux/module.h>
Michael S. Tsirkin4678d6f2012-01-12 15:44:44 +10307#include <linux/mutex.h>
Rusty Russelle467cde2007-10-22 11:03:38 +10008#include <linux/virtio.h>
9#include <linux/virtio_blk.h>
Jens Axboe3d1266c2007-10-24 13:21:21 +020010#include <linux/scatterlist.h>
Christoph Hellwig7a7c9242011-02-01 21:43:48 +010011#include <linux/string_helpers.h>
Liu Yuan6917f832011-04-24 02:49:26 +080012#include <scsi/scsi_cmnd.h>
Michael S. Tsirkin5087a502011-10-30 21:29:59 +020013#include <linux/idr.h>
Jens Axboe1cf7e9c2013-11-01 10:52:52 -060014#include <linux/blk-mq.h>
15#include <linux/numa.h>
Jens Axboe3d1266c2007-10-24 13:21:21 +020016
Christian Borntraeger4f3bf192008-01-31 15:53:53 +010017#define PART_BITS 4
Rusty Russelle467cde2007-10-22 11:03:38 +100018
Michael S. Tsirkin5087a502011-10-30 21:29:59 +020019static int major;
20static DEFINE_IDA(vd_index_ida);
21
Jonghwan Choi2a647bf2013-05-20 10:25:39 +093022static struct workqueue_struct *virtblk_wq;
Christian Borntraeger4f3bf192008-01-31 15:53:53 +010023
Rusty Russelle467cde2007-10-22 11:03:38 +100024struct virtio_blk
25{
Rusty Russelle467cde2007-10-22 11:03:38 +100026 struct virtio_device *vdev;
27 struct virtqueue *vq;
Jens Axboe1cf7e9c2013-11-01 10:52:52 -060028 spinlock_t vq_lock;
Rusty Russelle467cde2007-10-22 11:03:38 +100029
30 /* The disk structure for the kernel. */
31 struct gendisk *disk;
32
Christoph Hellwig7a7c9242011-02-01 21:43:48 +010033 /* Process context for config space updates */
34 struct work_struct config_work;
35
Michael S. Tsirkin4678d6f2012-01-12 15:44:44 +103036 /* Lock for config space updates */
37 struct mutex config_lock;
38
39 /* enable config space updates */
40 bool config_enable;
41
Rusty Russell0864b792008-12-30 09:26:05 -060042 /* What host tells us, plus 2 for header & tailer. */
43 unsigned int sg_elems;
44
Michael S. Tsirkin5087a502011-10-30 21:29:59 +020045 /* Ida index - used to track minor number allocations. */
46 int index;
Rusty Russelle467cde2007-10-22 11:03:38 +100047};
48
49struct virtblk_req
50{
Rusty Russelle467cde2007-10-22 11:03:38 +100051 struct request *req;
52 struct virtio_blk_outhdr out_hdr;
Hannes Reinecke1cde26f2009-05-18 14:41:30 +020053 struct virtio_scsi_inhdr in_hdr;
Rusty Russellcb38fa22008-05-02 21:50:45 -050054 u8 status;
Asias Hea98755c2012-08-08 16:07:04 +080055 struct scatterlist sg[];
Rusty Russelle467cde2007-10-22 11:03:38 +100056};
57
Asias Hea98755c2012-08-08 16:07:04 +080058static 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
Paolo Bonzini8f39db92013-03-20 15:44:27 +103070static int __virtblk_add_req(struct virtqueue *vq,
Paolo Bonzini20af3cf2013-03-20 15:44:27 +103071 struct virtblk_req *vbr,
72 struct scatterlist *data_sg,
Rusty Russell0a11cc32013-03-20 15:44:27 +103073 bool have_data)
Asias Hec85a1f92012-08-08 16:07:05 +080074{
Paolo Bonzini20af3cf2013-03-20 15:44:27 +103075 struct scatterlist hdr, status, cmd, sense, inhdr, *sgs[6];
Paolo Bonzini8f39db92013-03-20 15:44:27 +103076 unsigned int num_out = 0, num_in = 0;
Paolo Bonzini20af3cf2013-03-20 15:44:27 +103077 int type = vbr->out_hdr.type & ~VIRTIO_BLK_T_OUT;
Paolo Bonzini8f39db92013-03-20 15:44:27 +103078
79 sg_init_one(&hdr, &vbr->out_hdr, sizeof(vbr->out_hdr));
80 sgs[num_out++] = &hdr;
81
Paolo Bonzini20af3cf2013-03-20 15:44:27 +103082 /*
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
Rusty Russell0a11cc32013-03-20 15:44:27 +103093 if (have_data) {
Paolo Bonzini8f39db92013-03-20 15:44:27 +103094 if (vbr->out_hdr.type & VIRTIO_BLK_T_OUT)
Paolo Bonzini20af3cf2013-03-20 15:44:27 +103095 sgs[num_out++] = data_sg;
Paolo Bonzini8f39db92013-03-20 15:44:27 +103096 else
Paolo Bonzini20af3cf2013-03-20 15:44:27 +103097 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;
Paolo Bonzini8f39db92013-03-20 15:44:27 +1030105 }
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);
Paolo Bonzini5ee21a52013-03-20 15:44:27 +1030111}
Asias Hec85a1f92012-08-08 16:07:05 +0800112
Christoph Hellwig5124c282014-02-10 03:24:39 -0800113static inline void virtblk_request_done(struct request *req)
Asias Hec85a1f92012-08-08 16:07:05 +0800114{
Christoph Hellwig5124c282014-02-10 03:24:39 -0800115 struct virtblk_req *vbr = req->special;
Asias Hea98755c2012-08-08 16:07:04 +0800116 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
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600126 blk_mq_end_io(req, error);
Asias Hea98755c2012-08-08 16:07:04 +0800127}
128
129static void virtblk_done(struct virtqueue *vq)
Rusty Russelle467cde2007-10-22 11:03:38 +1000130{
131 struct virtio_blk *vblk = vq->vdev->priv;
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600132 bool req_done = false;
Rusty Russelle467cde2007-10-22 11:03:38 +1000133 struct virtblk_req *vbr;
Rusty Russelle467cde2007-10-22 11:03:38 +1000134 unsigned long flags;
Asias Hea98755c2012-08-08 16:07:04 +0800135 unsigned int len;
Rusty Russelle467cde2007-10-22 11:03:38 +1000136
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600137 spin_lock_irqsave(&vblk->vq_lock, flags);
Asias Hebb811102012-09-25 10:36:17 +0800138 do {
139 virtqueue_disable_cb(vq);
140 while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) {
Christoph Hellwig5124c282014-02-10 03:24:39 -0800141 blk_mq_complete_request(vbr->req);
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600142 req_done = true;
Rusty Russelle467cde2007-10-22 11:03:38 +1000143 }
Heinz Graalfs7f03b172013-10-29 09:40:30 +1030144 if (unlikely(virtqueue_is_broken(vq)))
145 break;
Asias Hebb811102012-09-25 10:36:17 +0800146 } while (!virtqueue_enable_cb(vq));
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600147 spin_unlock_irqrestore(&vblk->vq_lock, flags);
148
Rusty Russelle467cde2007-10-22 11:03:38 +1000149 /* In case queue is stopped waiting for more buffers. */
Asias Hea98755c2012-08-08 16:07:04 +0800150 if (req_done)
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600151 blk_mq_start_stopped_hw_queues(vblk->disk->queue);
Asias Hea98755c2012-08-08 16:07:04 +0800152}
153
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600154static int virtio_queue_rq(struct blk_mq_hw_ctx *hctx, struct request *req)
Rusty Russelle467cde2007-10-22 11:03:38 +1000155{
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600156 struct virtio_blk *vblk = hctx->queue->queuedata;
157 struct virtblk_req *vbr = req->special;
158 unsigned long flags;
Paolo Bonzini20af3cf2013-03-20 15:44:27 +1030159 unsigned int num;
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600160 const bool last = (req->cmd_flags & REQ_END) != 0;
Rusty Russell5261b852014-03-13 11:23:39 +1030161 int err;
Rusty Russelle467cde2007-10-22 11:03:38 +1000162
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600163 BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
Rusty Russelle467cde2007-10-22 11:03:38 +1000164
165 vbr->req = req;
FUJITA Tomonoridd40e452010-07-03 17:45:38 +0900166 if (req->cmd_flags & REQ_FLUSH) {
167 vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
Rusty Russelle467cde2007-10-22 11:03:38 +1000168 vbr->out_hdr.sector = 0;
Fernando Luis Vázquez Cao766ca442008-08-14 09:59:13 +0200169 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
FUJITA Tomonoridd40e452010-07-03 17:45:38 +0900170 } else {
171 switch (req->cmd_type) {
172 case REQ_TYPE_FS:
173 vbr->out_hdr.type = 0;
174 vbr->out_hdr.sector = blk_rq_pos(vbr->req);
175 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
176 break;
177 case REQ_TYPE_BLOCK_PC:
178 vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
Christoph Hellwigf1b0ef062009-09-17 19:57:42 +0200179 vbr->out_hdr.sector = 0;
180 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
181 break;
FUJITA Tomonoridd40e452010-07-03 17:45:38 +0900182 case REQ_TYPE_SPECIAL:
183 vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID;
184 vbr->out_hdr.sector = 0;
185 vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
186 break;
187 default:
188 /* We don't put anything else in the queue. */
189 BUG();
Christoph Hellwigf1b0ef062009-09-17 19:57:42 +0200190 }
Rusty Russelle467cde2007-10-22 11:03:38 +1000191 }
192
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600193 num = blk_rq_map_sg(hctx->queue, vbr->req, vbr->sg);
Hannes Reinecke1cde26f2009-05-18 14:41:30 +0200194 if (num) {
Paolo Bonzini20af3cf2013-03-20 15:44:27 +1030195 if (rq_data_dir(vbr->req) == WRITE)
Hannes Reinecke1cde26f2009-05-18 14:41:30 +0200196 vbr->out_hdr.type |= VIRTIO_BLK_T_OUT;
Paolo Bonzini20af3cf2013-03-20 15:44:27 +1030197 else
Hannes Reinecke1cde26f2009-05-18 14:41:30 +0200198 vbr->out_hdr.type |= VIRTIO_BLK_T_IN;
Rusty Russelle467cde2007-10-22 11:03:38 +1000199 }
200
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600201 spin_lock_irqsave(&vblk->vq_lock, flags);
Rusty Russell5261b852014-03-13 11:23:39 +1030202 err = __virtblk_add_req(vblk->vq, vbr, vbr->sg, num);
203 if (err) {
Shaohua Lif02b9ac2013-11-19 18:57:24 -0700204 virtqueue_kick(vblk->vq);
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600205 spin_unlock_irqrestore(&vblk->vq_lock, flags);
206 blk_mq_stop_hw_queue(hctx);
Rusty Russell5261b852014-03-13 11:23:39 +1030207 /* Out of mem doesn't actually happen, since we fall back
208 * to direct descriptors */
209 if (err == -ENOMEM || err == -ENOSPC)
210 return BLK_MQ_RQ_QUEUE_BUSY;
211 return BLK_MQ_RQ_QUEUE_ERROR;
Asias Hea98755c2012-08-08 16:07:04 +0800212 }
213
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600214 if (last)
215 virtqueue_kick(vblk->vq);
Shaohua Lif02b9ac2013-11-19 18:57:24 -0700216
217 spin_unlock_irqrestore(&vblk->vq_lock, flags);
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600218 return BLK_MQ_RQ_QUEUE_OK;
Asias Hea98755c2012-08-08 16:07:04 +0800219}
220
john cooper4cb2ea22010-03-25 01:33:33 -0400221/* return id (s/n) string for *disk to *id_str
222 */
223static int virtblk_get_id(struct gendisk *disk, char *id_str)
224{
225 struct virtio_blk *vblk = disk->private_data;
226 struct request *req;
227 struct bio *bio;
Mike Snitzere4c47762010-10-09 12:12:13 +1030228 int err;
john cooper4cb2ea22010-03-25 01:33:33 -0400229
230 bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,
231 GFP_KERNEL);
232 if (IS_ERR(bio))
233 return PTR_ERR(bio);
234
235 req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);
236 if (IS_ERR(req)) {
237 bio_put(bio);
238 return PTR_ERR(req);
239 }
240
241 req->cmd_type = REQ_TYPE_SPECIAL;
Mike Snitzere4c47762010-10-09 12:12:13 +1030242 err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
243 blk_put_request(req);
244
245 return err;
john cooper4cb2ea22010-03-25 01:33:33 -0400246}
247
Christoph Hellwigfe5a50a2010-09-15 01:27:23 +0200248static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
249 unsigned int cmd, unsigned long data)
Rusty Russelle467cde2007-10-22 11:03:38 +1000250{
Hannes Reinecke1cde26f2009-05-18 14:41:30 +0200251 struct gendisk *disk = bdev->bd_disk;
252 struct virtio_blk *vblk = disk->private_data;
253
254 /*
255 * Only allow the generic SCSI ioctls if the host can support it.
256 */
257 if (!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_SCSI))
Christoph Hellwigd9ecdea2009-06-20 21:29:41 +0200258 return -ENOTTY;
Hannes Reinecke1cde26f2009-05-18 14:41:30 +0200259
Paolo Bonzini577ebb32012-01-12 16:01:27 +0100260 return scsi_cmd_blk_ioctl(bdev, mode, cmd,
261 (void __user *)data);
Rusty Russelle467cde2007-10-22 11:03:38 +1000262}
263
Christian Borntraeger135da0b2008-01-23 17:56:50 +0100264/* We provide getgeo only to please some old bootloader/partitioning tools */
265static int virtblk_getgeo(struct block_device *bd, struct hd_geometry *geo)
266{
Ryan Harper48e40432008-04-16 13:56:37 -0500267 struct virtio_blk *vblk = bd->bd_disk->private_data;
Ryan Harper48e40432008-04-16 13:56:37 -0500268
269 /* see if the host passed in geometry config */
Rusty Russell855e0c52013-10-14 18:11:51 +1030270 if (virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_GEOMETRY)) {
271 virtio_cread(vblk->vdev, struct virtio_blk_config,
272 geometry.cylinders, &geo->cylinders);
273 virtio_cread(vblk->vdev, struct virtio_blk_config,
274 geometry.heads, &geo->heads);
275 virtio_cread(vblk->vdev, struct virtio_blk_config,
276 geometry.sectors, &geo->sectors);
Ryan Harper48e40432008-04-16 13:56:37 -0500277 } else {
278 /* some standard values, similar to sd */
279 geo->heads = 1 << 6;
280 geo->sectors = 1 << 5;
281 geo->cylinders = get_capacity(bd->bd_disk) >> 11;
282 }
Christian Borntraeger135da0b2008-01-23 17:56:50 +0100283 return 0;
284}
285
Alexey Dobriyan83d5cde2009-09-21 17:01:13 -0700286static const struct block_device_operations virtblk_fops = {
Arnd Bergmann8a6cfeb2010-07-08 10:18:46 +0200287 .ioctl = virtblk_ioctl,
Christian Borntraeger135da0b2008-01-23 17:56:50 +0100288 .owner = THIS_MODULE,
289 .getgeo = virtblk_getgeo,
Rusty Russelle467cde2007-10-22 11:03:38 +1000290};
291
Christian Borntraegerd50ed902008-02-01 09:05:00 +0100292static int index_to_minor(int index)
293{
294 return index << PART_BITS;
295}
296
Michael S. Tsirkin5087a502011-10-30 21:29:59 +0200297static int minor_to_index(int minor)
298{
299 return minor >> PART_BITS;
300}
301
Ryan Harpera5eb9e42010-06-23 22:19:57 -0500302static ssize_t virtblk_serial_show(struct device *dev,
303 struct device_attribute *attr, char *buf)
304{
305 struct gendisk *disk = dev_to_disk(dev);
306 int err;
307
308 /* sysfs gives us a PAGE_SIZE buffer */
309 BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
310
311 buf[VIRTIO_BLK_ID_BYTES] = '\0';
312 err = virtblk_get_id(disk, buf);
313 if (!err)
314 return strlen(buf);
315
316 if (err == -EIO) /* Unsupported? Make it empty. */
317 return 0;
318
319 return err;
320}
321DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
322
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100323static void virtblk_config_changed_work(struct work_struct *work)
324{
325 struct virtio_blk *vblk =
326 container_of(work, struct virtio_blk, config_work);
327 struct virtio_device *vdev = vblk->vdev;
328 struct request_queue *q = vblk->disk->queue;
329 char cap_str_2[10], cap_str_10[10];
Milos Vyletel9d9598b2013-03-12 15:34:40 +1030330 char *envp[] = { "RESIZE=1", NULL };
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100331 u64 capacity, size;
332
Michael S. Tsirkin4678d6f2012-01-12 15:44:44 +1030333 mutex_lock(&vblk->config_lock);
334 if (!vblk->config_enable)
335 goto done;
336
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100337 /* Host must always specify the capacity. */
Rusty Russell855e0c52013-10-14 18:11:51 +1030338 virtio_cread(vdev, struct virtio_blk_config, capacity, &capacity);
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100339
340 /* If capacity is too big, truncate with warning. */
341 if ((sector_t)capacity != capacity) {
342 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
343 (unsigned long long)capacity);
344 capacity = (sector_t)-1;
345 }
346
347 size = capacity * queue_logical_block_size(q);
348 string_get_size(size, STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
349 string_get_size(size, STRING_UNITS_10, cap_str_10, sizeof(cap_str_10));
350
351 dev_notice(&vdev->dev,
352 "new size: %llu %d-byte logical blocks (%s/%s)\n",
353 (unsigned long long)capacity,
354 queue_logical_block_size(q),
355 cap_str_10, cap_str_2);
356
357 set_capacity(vblk->disk, capacity);
Vivek Goyale9986f32012-03-29 10:09:44 +0200358 revalidate_disk(vblk->disk);
Milos Vyletel9d9598b2013-03-12 15:34:40 +1030359 kobject_uevent_env(&disk_to_dev(vblk->disk)->kobj, KOBJ_CHANGE, envp);
Michael S. Tsirkin4678d6f2012-01-12 15:44:44 +1030360done:
361 mutex_unlock(&vblk->config_lock);
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100362}
363
364static void virtblk_config_changed(struct virtio_device *vdev)
365{
366 struct virtio_blk *vblk = vdev->priv;
367
368 queue_work(virtblk_wq, &vblk->config_work);
369}
370
Amit Shah6abd6e52011-12-22 16:58:29 +0530371static int init_vq(struct virtio_blk *vblk)
372{
373 int err = 0;
374
375 /* We expect one virtqueue, for output. */
Asias Hea98755c2012-08-08 16:07:04 +0800376 vblk->vq = virtio_find_single_vq(vblk->vdev, virtblk_done, "requests");
Amit Shah6abd6e52011-12-22 16:58:29 +0530377 if (IS_ERR(vblk->vq))
378 err = PTR_ERR(vblk->vq);
379
380 return err;
381}
382
Ren Mingxinc0aa3e02012-04-10 15:28:05 +0800383/*
384 * Legacy naming scheme used for virtio devices. We are stuck with it for
385 * virtio blk but don't ever use it for any new driver.
386 */
387static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
388{
389 const int base = 'z' - 'a' + 1;
390 char *begin = buf + strlen(prefix);
391 char *end = buf + buflen;
392 char *p;
393 int unit;
394
395 p = end - 1;
396 *p = '\0';
397 unit = base;
398 do {
399 if (p == begin)
400 return -EINVAL;
401 *--p = 'a' + (index % unit);
402 index = (index / unit) - 1;
403 } while (index >= 0);
404
405 memmove(begin, p, end - p);
406 memcpy(buf, prefix, strlen(prefix));
407
408 return 0;
409}
410
Paolo Bonzinicd5d5032012-07-03 15:19:37 +0200411static int virtblk_get_cache_mode(struct virtio_device *vdev)
412{
413 u8 writeback;
414 int err;
415
Rusty Russell855e0c52013-10-14 18:11:51 +1030416 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE,
417 struct virtio_blk_config, wce,
418 &writeback);
Paolo Bonzinicd5d5032012-07-03 15:19:37 +0200419 if (err)
420 writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE);
421
422 return writeback;
423}
424
425static void virtblk_update_cache_mode(struct virtio_device *vdev)
426{
427 u8 writeback = virtblk_get_cache_mode(vdev);
428 struct virtio_blk *vblk = vdev->priv;
429
Asias Hec85a1f92012-08-08 16:07:05 +0800430 if (writeback)
Paolo Bonzinicd5d5032012-07-03 15:19:37 +0200431 blk_queue_flush(vblk->disk->queue, REQ_FLUSH);
432 else
433 blk_queue_flush(vblk->disk->queue, 0);
434
435 revalidate_disk(vblk->disk);
436}
437
438static const char *const virtblk_cache_types[] = {
439 "write through", "write back"
440};
441
442static ssize_t
443virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
444 const char *buf, size_t count)
445{
446 struct gendisk *disk = dev_to_disk(dev);
447 struct virtio_blk *vblk = disk->private_data;
448 struct virtio_device *vdev = vblk->vdev;
449 int i;
Paolo Bonzinicd5d5032012-07-03 15:19:37 +0200450
451 BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
452 for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; )
453 if (sysfs_streq(buf, virtblk_cache_types[i]))
454 break;
455
456 if (i < 0)
457 return -EINVAL;
458
Rusty Russell855e0c52013-10-14 18:11:51 +1030459 virtio_cwrite8(vdev, offsetof(struct virtio_blk_config, wce), i);
Paolo Bonzinicd5d5032012-07-03 15:19:37 +0200460 virtblk_update_cache_mode(vdev);
461 return count;
462}
463
464static ssize_t
465virtblk_cache_type_show(struct device *dev, struct device_attribute *attr,
466 char *buf)
467{
468 struct gendisk *disk = dev_to_disk(dev);
469 struct virtio_blk *vblk = disk->private_data;
470 u8 writeback = virtblk_get_cache_mode(vblk->vdev);
471
472 BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
473 return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
474}
475
476static const struct device_attribute dev_attr_cache_type_ro =
477 __ATTR(cache_type, S_IRUGO,
478 virtblk_cache_type_show, NULL);
479static const struct device_attribute dev_attr_cache_type_rw =
480 __ATTR(cache_type, S_IRUGO|S_IWUSR,
481 virtblk_cache_type_show, virtblk_cache_type_store);
482
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600483static struct blk_mq_ops virtio_mq_ops = {
484 .queue_rq = virtio_queue_rq,
485 .map_queue = blk_mq_map_queue,
486 .alloc_hctx = blk_mq_alloc_single_hw_queue,
487 .free_hctx = blk_mq_free_single_hw_queue,
Christoph Hellwig5124c282014-02-10 03:24:39 -0800488 .complete = virtblk_request_done,
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600489};
490
491static struct blk_mq_reg virtio_mq_reg = {
492 .ops = &virtio_mq_ops,
493 .nr_hw_queues = 1,
Rusty Russellfc4324b2014-03-19 17:08:24 +1030494 .queue_depth = 0, /* Set in virtblk_probe */
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600495 .numa_node = NUMA_NO_NODE,
496 .flags = BLK_MQ_F_SHOULD_MERGE,
497};
Rusty Russellfc4324b2014-03-19 17:08:24 +1030498module_param_named(queue_depth, virtio_mq_reg.queue_depth, uint, 0444);
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600499
Jens Axboe95363ef2014-03-14 10:43:15 -0600500static int virtblk_init_vbr(void *data, struct blk_mq_hw_ctx *hctx,
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600501 struct request *rq, unsigned int nr)
502{
503 struct virtio_blk *vblk = data;
504 struct virtblk_req *vbr = rq->special;
505
506 sg_init_table(vbr->sg, vblk->sg_elems);
Jens Axboe95363ef2014-03-14 10:43:15 -0600507 return 0;
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600508}
509
Greg Kroah-Hartman8d85fce2012-12-21 15:13:49 -0800510static int virtblk_probe(struct virtio_device *vdev)
Rusty Russelle467cde2007-10-22 11:03:38 +1000511{
512 struct virtio_blk *vblk;
Christoph Hellwig69740c82010-02-24 14:22:25 -0600513 struct request_queue *q;
Michael S. Tsirkin5087a502011-10-30 21:29:59 +0200514 int err, index;
Asias Hea98755c2012-08-08 16:07:04 +0800515
Rusty Russelle467cde2007-10-22 11:03:38 +1000516 u64 cap;
Christoph Hellwig69740c82010-02-24 14:22:25 -0600517 u32 v, blk_size, sg_elems, opt_io_size;
518 u16 min_io_size;
519 u8 physical_block_exp, alignment_offset;
Rusty Russelle467cde2007-10-22 11:03:38 +1000520
Michael S. Tsirkin5087a502011-10-30 21:29:59 +0200521 err = ida_simple_get(&vd_index_ida, 0, minor_to_index(1 << MINORBITS),
522 GFP_KERNEL);
523 if (err < 0)
524 goto out;
525 index = err;
Christian Borntraeger4f3bf192008-01-31 15:53:53 +0100526
Rusty Russell0864b792008-12-30 09:26:05 -0600527 /* We need to know how many segments before we allocate. */
Rusty Russell855e0c52013-10-14 18:11:51 +1030528 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SEG_MAX,
529 struct virtio_blk_config, seg_max,
530 &sg_elems);
Christoph Hellwiga5b365a2010-05-25 14:17:54 +0200531
532 /* We need at least one SG element, whatever they say. */
533 if (err || !sg_elems)
Rusty Russell0864b792008-12-30 09:26:05 -0600534 sg_elems = 1;
535
536 /* We need an extra sg elements at head and tail. */
537 sg_elems += 2;
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600538 vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
Rusty Russelle467cde2007-10-22 11:03:38 +1000539 if (!vblk) {
540 err = -ENOMEM;
Michael S. Tsirkin5087a502011-10-30 21:29:59 +0200541 goto out_free_index;
Rusty Russelle467cde2007-10-22 11:03:38 +1000542 }
543
Rusty Russelle467cde2007-10-22 11:03:38 +1000544 vblk->vdev = vdev;
Rusty Russell0864b792008-12-30 09:26:05 -0600545 vblk->sg_elems = sg_elems;
Michael S. Tsirkin4678d6f2012-01-12 15:44:44 +1030546 mutex_init(&vblk->config_lock);
Asias Hea98755c2012-08-08 16:07:04 +0800547
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100548 INIT_WORK(&vblk->config_work, virtblk_config_changed_work);
Michael S. Tsirkin4678d6f2012-01-12 15:44:44 +1030549 vblk->config_enable = true;
Rusty Russelle467cde2007-10-22 11:03:38 +1000550
Amit Shah6abd6e52011-12-22 16:58:29 +0530551 err = init_vq(vblk);
552 if (err)
Rusty Russelle467cde2007-10-22 11:03:38 +1000553 goto out_free_vblk;
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600554 spin_lock_init(&vblk->vq_lock);
Rusty Russelle467cde2007-10-22 11:03:38 +1000555
Rusty Russelle467cde2007-10-22 11:03:38 +1000556 /* FIXME: How many partitions? How long is a piece of string? */
Christian Borntraeger4f3bf192008-01-31 15:53:53 +0100557 vblk->disk = alloc_disk(1 << PART_BITS);
Rusty Russelle467cde2007-10-22 11:03:38 +1000558 if (!vblk->disk) {
559 err = -ENOMEM;
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600560 goto out_free_vq;
Rusty Russelle467cde2007-10-22 11:03:38 +1000561 }
562
Rusty Russellfc4324b2014-03-19 17:08:24 +1030563 /* Default queue sizing is to fill the ring. */
564 if (!virtio_mq_reg.queue_depth) {
565 virtio_mq_reg.queue_depth = vblk->vq->num_free;
566 /* ... but without indirect descs, we use 2 descs per req */
567 if (!virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC))
568 virtio_mq_reg.queue_depth /= 2;
569 }
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600570 virtio_mq_reg.cmd_size =
571 sizeof(struct virtblk_req) +
572 sizeof(struct scatterlist) * sg_elems;
573
574 q = vblk->disk->queue = blk_mq_init_queue(&virtio_mq_reg, vblk);
Christoph Hellwig69740c82010-02-24 14:22:25 -0600575 if (!q) {
Rusty Russelle467cde2007-10-22 11:03:38 +1000576 err = -ENOMEM;
577 goto out_put_disk;
578 }
579
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600580 blk_mq_init_commands(q, virtblk_init_vbr, vblk);
581
Christoph Hellwig69740c82010-02-24 14:22:25 -0600582 q->queuedata = vblk;
Fernando Luis Vázquez Cao7d116b62008-10-27 18:45:15 +0900583
Ren Mingxinc0aa3e02012-04-10 15:28:05 +0800584 virtblk_name_format("vd", index, vblk->disk->disk_name, DISK_NAME_LEN);
Christian Borntraegerd50ed902008-02-01 09:05:00 +0100585
Rusty Russelle467cde2007-10-22 11:03:38 +1000586 vblk->disk->major = major;
Christian Borntraegerd50ed902008-02-01 09:05:00 +0100587 vblk->disk->first_minor = index_to_minor(index);
Rusty Russelle467cde2007-10-22 11:03:38 +1000588 vblk->disk->private_data = vblk;
589 vblk->disk->fops = &virtblk_fops;
Jeremy Katzc4839342008-03-02 17:00:15 -0500590 vblk->disk->driverfs_dev = &vdev->dev;
Michael S. Tsirkin5087a502011-10-30 21:29:59 +0200591 vblk->index = index;
Christian Borntraeger4f3bf192008-01-31 15:53:53 +0100592
Tejun Heo02c42b72010-09-03 11:56:18 +0200593 /* configure queue flush support */
Paolo Bonzinicd5d5032012-07-03 15:19:37 +0200594 virtblk_update_cache_mode(vdev);
Rusty Russelle467cde2007-10-22 11:03:38 +1000595
Christian Borntraeger3ef53602008-05-16 11:17:03 +0200596 /* If disk is read-only in the host, the guest should obey */
597 if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
598 set_disk_ro(vblk->disk, 1);
599
Rusty Russella586d4f2008-02-04 23:49:56 -0500600 /* Host must always specify the capacity. */
Rusty Russell855e0c52013-10-14 18:11:51 +1030601 virtio_cread(vdev, struct virtio_blk_config, capacity, &cap);
Rusty Russelle467cde2007-10-22 11:03:38 +1000602
603 /* If capacity is too big, truncate with warning. */
604 if ((sector_t)cap != cap) {
605 dev_warn(&vdev->dev, "Capacity %llu too large: truncating\n",
606 (unsigned long long)cap);
607 cap = (sector_t)-1;
608 }
609 set_capacity(vblk->disk, cap);
610
Rusty Russell0864b792008-12-30 09:26:05 -0600611 /* We can handle whatever the host told us to handle. */
Martin K. Petersenee714f22010-03-10 00:48:32 -0500612 blk_queue_max_segments(q, vblk->sg_elems-2);
Rusty Russell0864b792008-12-30 09:26:05 -0600613
Christoph Hellwig4eff3ca2009-07-17 21:47:45 -0600614 /* No need to bounce any requests */
Christoph Hellwig69740c82010-02-24 14:22:25 -0600615 blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
Christoph Hellwig4eff3ca2009-07-17 21:47:45 -0600616
Rusty Russell4b7f7e22008-12-30 09:26:04 -0600617 /* No real sector limit. */
Martin K. Petersenee714f22010-03-10 00:48:32 -0500618 blk_queue_max_hw_sectors(q, -1U);
Rusty Russell4b7f7e22008-12-30 09:26:04 -0600619
Rusty Russella586d4f2008-02-04 23:49:56 -0500620 /* Host can optionally specify maximum segment size and number of
621 * segments. */
Rusty Russell855e0c52013-10-14 18:11:51 +1030622 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
623 struct virtio_blk_config, size_max, &v);
Rusty Russelle467cde2007-10-22 11:03:38 +1000624 if (!err)
Christoph Hellwig69740c82010-02-24 14:22:25 -0600625 blk_queue_max_segment_size(q, v);
Rusty Russell4b7f7e22008-12-30 09:26:04 -0600626 else
Christoph Hellwig69740c82010-02-24 14:22:25 -0600627 blk_queue_max_segment_size(q, -1U);
Rusty Russelle467cde2007-10-22 11:03:38 +1000628
Christian Borntraeger066f4d82008-05-29 11:08:26 +0200629 /* Host can optionally specify the block size of the device */
Rusty Russell855e0c52013-10-14 18:11:51 +1030630 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,
631 struct virtio_blk_config, blk_size,
632 &blk_size);
Christian Borntraeger066f4d82008-05-29 11:08:26 +0200633 if (!err)
Christoph Hellwig69740c82010-02-24 14:22:25 -0600634 blk_queue_logical_block_size(q, blk_size);
635 else
636 blk_size = queue_logical_block_size(q);
637
638 /* Use topology information if available */
Rusty Russell855e0c52013-10-14 18:11:51 +1030639 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
640 struct virtio_blk_config, physical_block_exp,
641 &physical_block_exp);
Christoph Hellwig69740c82010-02-24 14:22:25 -0600642 if (!err && physical_block_exp)
643 blk_queue_physical_block_size(q,
644 blk_size * (1 << physical_block_exp));
645
Rusty Russell855e0c52013-10-14 18:11:51 +1030646 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
647 struct virtio_blk_config, alignment_offset,
648 &alignment_offset);
Christoph Hellwig69740c82010-02-24 14:22:25 -0600649 if (!err && alignment_offset)
650 blk_queue_alignment_offset(q, blk_size * alignment_offset);
651
Rusty Russell855e0c52013-10-14 18:11:51 +1030652 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
653 struct virtio_blk_config, min_io_size,
654 &min_io_size);
Christoph Hellwig69740c82010-02-24 14:22:25 -0600655 if (!err && min_io_size)
656 blk_queue_io_min(q, blk_size * min_io_size);
657
Rusty Russell855e0c52013-10-14 18:11:51 +1030658 err = virtio_cread_feature(vdev, VIRTIO_BLK_F_TOPOLOGY,
659 struct virtio_blk_config, opt_io_size,
660 &opt_io_size);
Christoph Hellwig69740c82010-02-24 14:22:25 -0600661 if (!err && opt_io_size)
662 blk_queue_io_opt(q, blk_size * opt_io_size);
663
Rusty Russelle467cde2007-10-22 11:03:38 +1000664 add_disk(vblk->disk);
Ryan Harpera5eb9e42010-06-23 22:19:57 -0500665 err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
666 if (err)
667 goto out_del_disk;
668
Paolo Bonzinicd5d5032012-07-03 15:19:37 +0200669 if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
670 err = device_create_file(disk_to_dev(vblk->disk),
671 &dev_attr_cache_type_rw);
672 else
673 err = device_create_file(disk_to_dev(vblk->disk),
674 &dev_attr_cache_type_ro);
675 if (err)
676 goto out_del_disk;
Rusty Russelle467cde2007-10-22 11:03:38 +1000677 return 0;
678
Ryan Harpera5eb9e42010-06-23 22:19:57 -0500679out_del_disk:
680 del_gendisk(vblk->disk);
681 blk_cleanup_queue(vblk->disk->queue);
Rusty Russelle467cde2007-10-22 11:03:38 +1000682out_put_disk:
683 put_disk(vblk->disk);
Rusty Russelle467cde2007-10-22 11:03:38 +1000684out_free_vq:
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600685 vdev->config->del_vqs(vdev);
Rusty Russelle467cde2007-10-22 11:03:38 +1000686out_free_vblk:
687 kfree(vblk);
Michael S. Tsirkin5087a502011-10-30 21:29:59 +0200688out_free_index:
689 ida_simple_remove(&vd_index_ida, index);
Rusty Russelle467cde2007-10-22 11:03:38 +1000690out:
691 return err;
692}
693
Greg Kroah-Hartman8d85fce2012-12-21 15:13:49 -0800694static void virtblk_remove(struct virtio_device *vdev)
Rusty Russelle467cde2007-10-22 11:03:38 +1000695{
696 struct virtio_blk *vblk = vdev->priv;
Michael S. Tsirkin5087a502011-10-30 21:29:59 +0200697 int index = vblk->index;
Alexander Graff4953fe2013-01-02 15:37:17 +1030698 int refc;
Rusty Russelle467cde2007-10-22 11:03:38 +1000699
Michael S. Tsirkin4678d6f2012-01-12 15:44:44 +1030700 /* Prevent config work handler from accessing the device. */
701 mutex_lock(&vblk->config_lock);
702 vblk->config_enable = false;
703 mutex_unlock(&vblk->config_lock);
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100704
Asias He02e2b122012-05-25 10:34:47 +0800705 del_gendisk(vblk->disk);
Asias He483001c2012-05-25 10:34:48 +0800706 blk_cleanup_queue(vblk->disk->queue);
Asias He02e2b122012-05-25 10:34:47 +0800707
Rusty Russell6e5aa7e2008-02-04 23:50:03 -0500708 /* Stop all the virtqueues. */
709 vdev->config->reset(vdev);
710
Michael S. Tsirkin4678d6f2012-01-12 15:44:44 +1030711 flush_work(&vblk->config_work);
712
Alexander Graff4953fe2013-01-02 15:37:17 +1030713 refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
Rusty Russelle467cde2007-10-22 11:03:38 +1000714 put_disk(vblk->disk);
Michael S. Tsirkind2a7ddd2009-06-12 22:16:36 -0600715 vdev->config->del_vqs(vdev);
Rusty Russelle467cde2007-10-22 11:03:38 +1000716 kfree(vblk);
Alexander Graff4953fe2013-01-02 15:37:17 +1030717
718 /* Only free device id if we don't have any users */
719 if (refc == 1)
720 ida_simple_remove(&vd_index_ida, index);
Rusty Russelle467cde2007-10-22 11:03:38 +1000721}
722
Aaron Lu89107002013-09-17 09:25:23 +0930723#ifdef CONFIG_PM_SLEEP
Amit Shahf8fb5bc2011-12-22 16:58:30 +0530724static int virtblk_freeze(struct virtio_device *vdev)
725{
726 struct virtio_blk *vblk = vdev->priv;
727
728 /* Ensure we don't receive any more interrupts */
729 vdev->config->reset(vdev);
730
731 /* Prevent config work handler from accessing the device. */
732 mutex_lock(&vblk->config_lock);
733 vblk->config_enable = false;
734 mutex_unlock(&vblk->config_lock);
735
736 flush_work(&vblk->config_work);
737
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600738 blk_mq_stop_hw_queues(vblk->disk->queue);
Amit Shahf8fb5bc2011-12-22 16:58:30 +0530739
740 vdev->config->del_vqs(vdev);
741 return 0;
742}
743
744static int virtblk_restore(struct virtio_device *vdev)
745{
746 struct virtio_blk *vblk = vdev->priv;
747 int ret;
748
749 vblk->config_enable = true;
750 ret = init_vq(vdev->priv);
Jens Axboe1cf7e9c2013-11-01 10:52:52 -0600751 if (!ret)
752 blk_mq_start_stopped_hw_queues(vblk->disk->queue);
753
Amit Shahf8fb5bc2011-12-22 16:58:30 +0530754 return ret;
755}
756#endif
757
Márton Németh47483e22010-01-10 13:40:02 +0100758static const struct virtio_device_id id_table[] = {
Rusty Russelle467cde2007-10-22 11:03:38 +1000759 { VIRTIO_ID_BLOCK, VIRTIO_DEV_ANY_ID },
760 { 0 },
761};
762
Rusty Russellc45a6812008-05-02 21:50:50 -0500763static unsigned int features[] = {
Tejun Heo02c42b72010-09-03 11:56:18 +0200764 VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
765 VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
Paolo Bonzinicd5d5032012-07-03 15:19:37 +0200766 VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE
Rusty Russellc45a6812008-05-02 21:50:50 -0500767};
768
Greg Kroah-Hartman8d85fce2012-12-21 15:13:49 -0800769static struct virtio_driver virtio_blk = {
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100770 .feature_table = features,
771 .feature_table_size = ARRAY_SIZE(features),
772 .driver.name = KBUILD_MODNAME,
773 .driver.owner = THIS_MODULE,
774 .id_table = id_table,
775 .probe = virtblk_probe,
Greg Kroah-Hartman8d85fce2012-12-21 15:13:49 -0800776 .remove = virtblk_remove,
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100777 .config_changed = virtblk_config_changed,
Aaron Lu89107002013-09-17 09:25:23 +0930778#ifdef CONFIG_PM_SLEEP
Amit Shahf8fb5bc2011-12-22 16:58:30 +0530779 .freeze = virtblk_freeze,
780 .restore = virtblk_restore,
781#endif
Rusty Russelle467cde2007-10-22 11:03:38 +1000782};
783
784static int __init init(void)
785{
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100786 int error;
787
788 virtblk_wq = alloc_workqueue("virtio-blk", 0, 0);
789 if (!virtblk_wq)
790 return -ENOMEM;
791
Christian Borntraeger4f3bf192008-01-31 15:53:53 +0100792 major = register_blkdev(0, "virtblk");
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100793 if (major < 0) {
794 error = major;
795 goto out_destroy_workqueue;
796 }
797
798 error = register_virtio_driver(&virtio_blk);
799 if (error)
800 goto out_unregister_blkdev;
801 return 0;
802
803out_unregister_blkdev:
804 unregister_blkdev(major, "virtblk");
805out_destroy_workqueue:
806 destroy_workqueue(virtblk_wq);
807 return error;
Rusty Russelle467cde2007-10-22 11:03:38 +1000808}
809
810static void __exit fini(void)
811{
Christian Borntraeger4f3bf192008-01-31 15:53:53 +0100812 unregister_blkdev(major, "virtblk");
Rusty Russelle467cde2007-10-22 11:03:38 +1000813 unregister_virtio_driver(&virtio_blk);
Christoph Hellwig7a7c9242011-02-01 21:43:48 +0100814 destroy_workqueue(virtblk_wq);
Rusty Russelle467cde2007-10-22 11:03:38 +1000815}
816module_init(init);
817module_exit(fini);
818
819MODULE_DEVICE_TABLE(virtio, id_table);
820MODULE_DESCRIPTION("Virtio block driver");
821MODULE_LICENSE("GPL");