Commit | Line | Data |
---|---|---|
4d05a28d KRW |
1 | /* Xenbus code for blkif backend |
2 | Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au> | |
3 | Copyright (C) 2005 XenSource Ltd | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 2 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
4d05a28d KRW |
15 | */ |
16 | ||
77387b82 TC |
17 | #define pr_fmt(fmt) "xen-blkback: " fmt |
18 | ||
4d05a28d KRW |
19 | #include <stdarg.h> |
20 | #include <linux/module.h> | |
21 | #include <linux/kthread.h> | |
ee9ff853 KRW |
22 | #include <xen/events.h> |
23 | #include <xen/grant_table.h> | |
4d05a28d KRW |
24 | #include "common.h" |
25 | ||
1375590d TC |
26 | /* Enlarge the array size in order to fully show blkback name. */ |
27 | #define BLKBACK_NAME_LEN (20) | |
86839c56 | 28 | #define RINGREF_NAME_LEN (20) |
1375590d | 29 | |
d6091b21 | 30 | struct backend_info { |
01f37f2d | 31 | struct xenbus_device *dev; |
51854322 | 32 | struct xen_blkif *blkif; |
01f37f2d KRW |
33 | struct xenbus_watch backend_watch; |
34 | unsigned major; | |
35 | unsigned minor; | |
36 | char *mode; | |
4d05a28d KRW |
37 | }; |
38 | ||
8b6bf747 | 39 | static struct kmem_cache *xen_blkif_cachep; |
4d05a28d KRW |
40 | static void connect(struct backend_info *); |
41 | static int connect_ring(struct backend_info *); | |
42 | static void backend_changed(struct xenbus_watch *, const char **, | |
43 | unsigned int); | |
814d04e7 VP |
44 | static void xen_blkif_free(struct xen_blkif *blkif); |
45 | static void xen_vbd_free(struct xen_vbd *vbd); | |
4d05a28d | 46 | |
8b6bf747 | 47 | struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be) |
98e036a3 JF |
48 | { |
49 | return be->dev; | |
50 | } | |
51 | ||
814d04e7 VP |
52 | /* |
53 | * The last request could free the device from softirq context and | |
54 | * xen_blkif_free() can sleep. | |
55 | */ | |
56 | static void xen_blkif_deferred_free(struct work_struct *work) | |
57 | { | |
58 | struct xen_blkif *blkif; | |
59 | ||
60 | blkif = container_of(work, struct xen_blkif, free_work); | |
61 | xen_blkif_free(blkif); | |
62 | } | |
63 | ||
30fd1502 | 64 | static int blkback_name(struct xen_blkif *blkif, char *buf) |
4d05a28d KRW |
65 | { |
66 | char *devpath, *devname; | |
67 | struct xenbus_device *dev = blkif->be->dev; | |
68 | ||
69 | devpath = xenbus_read(XBT_NIL, dev->nodename, "dev", NULL); | |
70 | if (IS_ERR(devpath)) | |
71 | return PTR_ERR(devpath); | |
72 | ||
d6091b21 KRW |
73 | devname = strstr(devpath, "/dev/"); |
74 | if (devname != NULL) | |
4d05a28d KRW |
75 | devname += strlen("/dev/"); |
76 | else | |
77 | devname = devpath; | |
78 | ||
1375590d | 79 | snprintf(buf, BLKBACK_NAME_LEN, "blkback.%d.%s", blkif->domid, devname); |
4d05a28d KRW |
80 | kfree(devpath); |
81 | ||
82 | return 0; | |
83 | } | |
84 | ||
30fd1502 | 85 | static void xen_update_blkif_status(struct xen_blkif *blkif) |
4d05a28d KRW |
86 | { |
87 | int err; | |
1375590d | 88 | char name[BLKBACK_NAME_LEN]; |
4d05a28d KRW |
89 | |
90 | /* Not ready to connect? */ | |
59795700 | 91 | if (!blkif->ring.irq || !blkif->vbd.bdev) |
4d05a28d KRW |
92 | return; |
93 | ||
94 | /* Already connected? */ | |
95 | if (blkif->be->dev->state == XenbusStateConnected) | |
96 | return; | |
97 | ||
98 | /* Attempt to connect: exit if we fail to. */ | |
99 | connect(blkif->be); | |
100 | if (blkif->be->dev->state != XenbusStateConnected) | |
101 | return; | |
102 | ||
103 | err = blkback_name(blkif, name); | |
104 | if (err) { | |
105 | xenbus_dev_error(blkif->be->dev, err, "get blkback dev name"); | |
106 | return; | |
107 | } | |
108 | ||
cbf46290 CL |
109 | err = filemap_write_and_wait(blkif->vbd.bdev->bd_inode->i_mapping); |
110 | if (err) { | |
111 | xenbus_dev_error(blkif->be->dev, err, "block flush"); | |
112 | return; | |
113 | } | |
114 | invalidate_inode_pages2(blkif->vbd.bdev->bd_inode->i_mapping); | |
115 | ||
59795700 BL |
116 | blkif->ring.xenblkd = kthread_run(xen_blkif_schedule, &blkif->ring, "%s", name); |
117 | if (IS_ERR(blkif->ring.xenblkd)) { | |
118 | err = PTR_ERR(blkif->ring.xenblkd); | |
119 | blkif->ring.xenblkd = NULL; | |
4d05a28d | 120 | xenbus_dev_error(blkif->be->dev, err, "start xenblkd"); |
3f3aad5e | 121 | return; |
4d05a28d KRW |
122 | } |
123 | } | |
124 | ||
30fd1502 | 125 | static struct xen_blkif *xen_blkif_alloc(domid_t domid) |
ee9ff853 | 126 | { |
30fd1502 | 127 | struct xen_blkif *blkif; |
59795700 | 128 | struct xen_blkif_ring *ring; |
ee9ff853 | 129 | |
402b27f9 | 130 | BUILD_BUG_ON(MAX_INDIRECT_PAGES > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST); |
ee9ff853 | 131 | |
654dbef2 | 132 | blkif = kmem_cache_zalloc(xen_blkif_cachep, GFP_KERNEL); |
ee9ff853 KRW |
133 | if (!blkif) |
134 | return ERR_PTR(-ENOMEM); | |
135 | ||
ee9ff853 | 136 | blkif->domid = domid; |
ee9ff853 | 137 | atomic_set(&blkif->refcnt, 1); |
29bde093 | 138 | init_completion(&blkif->drain_complete); |
59795700 | 139 | INIT_WORK(&blkif->free_work, xen_blkif_deferred_free); |
c6cc142d RPM |
140 | spin_lock_init(&blkif->free_pages_lock); |
141 | INIT_LIST_HEAD(&blkif->free_pages); | |
ef753411 | 142 | INIT_LIST_HEAD(&blkif->persistent_purge_list); |
59795700 | 143 | blkif->st_print = jiffies; |
abb97b8c | 144 | INIT_WORK(&blkif->persistent_purge_work, xen_blkbk_unmap_purged_grants); |
ee9ff853 | 145 | |
59795700 BL |
146 | ring = &blkif->ring; |
147 | ring->blkif = blkif; | |
148 | spin_lock_init(&ring->blk_ring_lock); | |
149 | init_waitqueue_head(&ring->wq); | |
150 | ||
151 | INIT_LIST_HEAD(&ring->pending_free); | |
152 | spin_lock_init(&ring->pending_free_lock); | |
153 | init_waitqueue_head(&ring->pending_free_wq); | |
154 | init_waitqueue_head(&ring->shutdown_wq); | |
ee9ff853 KRW |
155 | |
156 | return blkif; | |
157 | } | |
158 | ||
59795700 | 159 | static int xen_blkif_map(struct xen_blkif_ring *ring, grant_ref_t *gref, |
86839c56 | 160 | unsigned int nr_grefs, unsigned int evtchn) |
ee9ff853 KRW |
161 | { |
162 | int err; | |
59795700 | 163 | struct xen_blkif *blkif = ring->blkif; |
ee9ff853 KRW |
164 | |
165 | /* Already connected through? */ | |
59795700 | 166 | if (ring->irq) |
ee9ff853 KRW |
167 | return 0; |
168 | ||
86839c56 | 169 | err = xenbus_map_ring_valloc(blkif->be->dev, gref, nr_grefs, |
59795700 | 170 | &ring->blk_ring); |
2d073846 | 171 | if (err < 0) |
ee9ff853 | 172 | return err; |
ee9ff853 KRW |
173 | |
174 | switch (blkif->blk_protocol) { | |
175 | case BLKIF_PROTOCOL_NATIVE: | |
176 | { | |
177 | struct blkif_sring *sring; | |
59795700 BL |
178 | sring = (struct blkif_sring *)ring->blk_ring; |
179 | BACK_RING_INIT(&ring->blk_rings.native, sring, | |
67de5dfb | 180 | XEN_PAGE_SIZE * nr_grefs); |
ee9ff853 KRW |
181 | break; |
182 | } | |
183 | case BLKIF_PROTOCOL_X86_32: | |
184 | { | |
185 | struct blkif_x86_32_sring *sring_x86_32; | |
59795700 BL |
186 | sring_x86_32 = (struct blkif_x86_32_sring *)ring->blk_ring; |
187 | BACK_RING_INIT(&ring->blk_rings.x86_32, sring_x86_32, | |
67de5dfb | 188 | XEN_PAGE_SIZE * nr_grefs); |
ee9ff853 KRW |
189 | break; |
190 | } | |
191 | case BLKIF_PROTOCOL_X86_64: | |
192 | { | |
193 | struct blkif_x86_64_sring *sring_x86_64; | |
59795700 BL |
194 | sring_x86_64 = (struct blkif_x86_64_sring *)ring->blk_ring; |
195 | BACK_RING_INIT(&ring->blk_rings.x86_64, sring_x86_64, | |
67de5dfb | 196 | XEN_PAGE_SIZE * nr_grefs); |
ee9ff853 KRW |
197 | break; |
198 | } | |
199 | default: | |
200 | BUG(); | |
201 | } | |
202 | ||
8b6bf747 KRW |
203 | err = bind_interdomain_evtchn_to_irqhandler(blkif->domid, evtchn, |
204 | xen_blkif_be_int, 0, | |
59795700 | 205 | "blkif-backend", ring); |
ee9ff853 | 206 | if (err < 0) { |
59795700 BL |
207 | xenbus_unmap_ring_vfree(blkif->be->dev, ring->blk_ring); |
208 | ring->blk_rings.common.sring = NULL; | |
ee9ff853 KRW |
209 | return err; |
210 | } | |
59795700 | 211 | ring->irq = err; |
ee9ff853 KRW |
212 | |
213 | return 0; | |
214 | } | |
215 | ||
814d04e7 | 216 | static int xen_blkif_disconnect(struct xen_blkif *blkif) |
ee9ff853 | 217 | { |
f929d42c RPM |
218 | struct pending_req *req, *n; |
219 | int i = 0, j; | |
59795700 | 220 | struct xen_blkif_ring *ring = &blkif->ring; |
f929d42c | 221 | |
59795700 BL |
222 | if (ring->xenblkd) { |
223 | kthread_stop(ring->xenblkd); | |
224 | wake_up(&ring->shutdown_wq); | |
225 | ring->xenblkd = NULL; | |
ee9ff853 KRW |
226 | } |
227 | ||
814d04e7 VP |
228 | /* The above kthread_stop() guarantees that at this point we |
229 | * don't have any discard_io or other_io requests. So, checking | |
230 | * for inflight IO is enough. | |
231 | */ | |
59795700 | 232 | if (atomic_read(&ring->inflight) > 0) |
814d04e7 | 233 | return -EBUSY; |
ee9ff853 | 234 | |
59795700 BL |
235 | if (ring->irq) { |
236 | unbind_from_irqhandler(ring->irq, ring); | |
237 | ring->irq = 0; | |
ee9ff853 KRW |
238 | } |
239 | ||
59795700 BL |
240 | if (ring->blk_rings.common.sring) { |
241 | xenbus_unmap_ring_vfree(blkif->be->dev, ring->blk_ring); | |
242 | ring->blk_rings.common.sring = NULL; | |
ee9ff853 | 243 | } |
814d04e7 | 244 | |
12ea7296 | 245 | /* Remove all persistent grants and the cache of ballooned pages. */ |
59795700 | 246 | xen_blkbk_free_caches(ring); |
12ea7296 | 247 | |
f929d42c | 248 | /* Check that there is no request in use */ |
59795700 | 249 | list_for_each_entry_safe(req, n, &ring->pending_free, free_list) { |
f929d42c RPM |
250 | list_del(&req->free_list); |
251 | ||
252 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) | |
253 | kfree(req->segments[j]); | |
254 | ||
255 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) | |
256 | kfree(req->indirect_pages[j]); | |
257 | ||
258 | kfree(req); | |
259 | i++; | |
260 | } | |
261 | ||
262 | WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif->nr_ring_pages)); | |
263 | blkif->nr_ring_pages = 0; | |
264 | ||
814d04e7 | 265 | return 0; |
ee9ff853 KRW |
266 | } |
267 | ||
2911758f | 268 | static void xen_blkif_free(struct xen_blkif *blkif) |
ee9ff853 | 269 | { |
bf0720c4 | 270 | |
814d04e7 VP |
271 | xen_blkif_disconnect(blkif); |
272 | xen_vbd_free(&blkif->vbd); | |
bf0720c4 | 273 | |
ef753411 RPM |
274 | /* Make sure everything is drained before shutting down */ |
275 | BUG_ON(blkif->persistent_gnt_c != 0); | |
276 | BUG_ON(atomic_read(&blkif->persistent_gnt_in_use) != 0); | |
277 | BUG_ON(blkif->free_pages_num != 0); | |
278 | BUG_ON(!list_empty(&blkif->persistent_purge_list)); | |
279 | BUG_ON(!list_empty(&blkif->free_pages)); | |
280 | BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts)); | |
281 | ||
8b6bf747 | 282 | kmem_cache_free(xen_blkif_cachep, blkif); |
ee9ff853 KRW |
283 | } |
284 | ||
8b6bf747 | 285 | int __init xen_blkif_interface_init(void) |
ee9ff853 | 286 | { |
8b6bf747 | 287 | xen_blkif_cachep = kmem_cache_create("blkif_cache", |
30fd1502 | 288 | sizeof(struct xen_blkif), |
8b6bf747 KRW |
289 | 0, 0, NULL); |
290 | if (!xen_blkif_cachep) | |
ee9ff853 KRW |
291 | return -ENOMEM; |
292 | ||
293 | return 0; | |
294 | } | |
4d05a28d | 295 | |
a1397fa3 | 296 | /* |
4d05a28d KRW |
297 | * sysfs interface for VBD I/O requests |
298 | */ | |
299 | ||
300 | #define VBD_SHOW(name, format, args...) \ | |
301 | static ssize_t show_##name(struct device *_dev, \ | |
302 | struct device_attribute *attr, \ | |
303 | char *buf) \ | |
304 | { \ | |
305 | struct xenbus_device *dev = to_xenbus_device(_dev); \ | |
5cf6e4f6 | 306 | struct backend_info *be = dev_get_drvdata(&dev->dev); \ |
4d05a28d KRW |
307 | \ |
308 | return sprintf(buf, format, ##args); \ | |
309 | } \ | |
310 | static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL) | |
311 | ||
986cacbd ZK |
312 | VBD_SHOW(oo_req, "%llu\n", be->blkif->st_oo_req); |
313 | VBD_SHOW(rd_req, "%llu\n", be->blkif->st_rd_req); | |
314 | VBD_SHOW(wr_req, "%llu\n", be->blkif->st_wr_req); | |
315 | VBD_SHOW(f_req, "%llu\n", be->blkif->st_f_req); | |
316 | VBD_SHOW(ds_req, "%llu\n", be->blkif->st_ds_req); | |
317 | VBD_SHOW(rd_sect, "%llu\n", be->blkif->st_rd_sect); | |
318 | VBD_SHOW(wr_sect, "%llu\n", be->blkif->st_wr_sect); | |
4d05a28d | 319 | |
3d814731 | 320 | static struct attribute *xen_vbdstat_attrs[] = { |
4d05a28d KRW |
321 | &dev_attr_oo_req.attr, |
322 | &dev_attr_rd_req.attr, | |
323 | &dev_attr_wr_req.attr, | |
24f567f9 | 324 | &dev_attr_f_req.attr, |
b3cb0d6a | 325 | &dev_attr_ds_req.attr, |
4d05a28d KRW |
326 | &dev_attr_rd_sect.attr, |
327 | &dev_attr_wr_sect.attr, | |
328 | NULL | |
329 | }; | |
330 | ||
3d814731 | 331 | static struct attribute_group xen_vbdstat_group = { |
4d05a28d | 332 | .name = "statistics", |
3d814731 | 333 | .attrs = xen_vbdstat_attrs, |
4d05a28d KRW |
334 | }; |
335 | ||
336 | VBD_SHOW(physical_device, "%x:%x\n", be->major, be->minor); | |
337 | VBD_SHOW(mode, "%s\n", be->mode); | |
338 | ||
2911758f | 339 | static int xenvbd_sysfs_addif(struct xenbus_device *dev) |
4d05a28d KRW |
340 | { |
341 | int error; | |
342 | ||
343 | error = device_create_file(&dev->dev, &dev_attr_physical_device); | |
d6091b21 | 344 | if (error) |
4d05a28d KRW |
345 | goto fail1; |
346 | ||
347 | error = device_create_file(&dev->dev, &dev_attr_mode); | |
348 | if (error) | |
349 | goto fail2; | |
350 | ||
3d814731 | 351 | error = sysfs_create_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
352 | if (error) |
353 | goto fail3; | |
354 | ||
355 | return 0; | |
356 | ||
3d814731 | 357 | fail3: sysfs_remove_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
358 | fail2: device_remove_file(&dev->dev, &dev_attr_mode); |
359 | fail1: device_remove_file(&dev->dev, &dev_attr_physical_device); | |
360 | return error; | |
361 | } | |
362 | ||
2911758f | 363 | static void xenvbd_sysfs_delif(struct xenbus_device *dev) |
4d05a28d | 364 | { |
3d814731 | 365 | sysfs_remove_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
366 | device_remove_file(&dev->dev, &dev_attr_mode); |
367 | device_remove_file(&dev->dev, &dev_attr_physical_device); | |
368 | } | |
369 | ||
42c7841d | 370 | |
3d814731 | 371 | static void xen_vbd_free(struct xen_vbd *vbd) |
42c7841d KRW |
372 | { |
373 | if (vbd->bdev) | |
374 | blkdev_put(vbd->bdev, vbd->readonly ? FMODE_READ : FMODE_WRITE); | |
375 | vbd->bdev = NULL; | |
376 | } | |
377 | ||
3d814731 KRW |
378 | static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle, |
379 | unsigned major, unsigned minor, int readonly, | |
380 | int cdrom) | |
42c7841d | 381 | { |
3d814731 | 382 | struct xen_vbd *vbd; |
42c7841d | 383 | struct block_device *bdev; |
24f567f9 | 384 | struct request_queue *q; |
42c7841d KRW |
385 | |
386 | vbd = &blkif->vbd; | |
387 | vbd->handle = handle; | |
388 | vbd->readonly = readonly; | |
389 | vbd->type = 0; | |
390 | ||
391 | vbd->pdevice = MKDEV(major, minor); | |
392 | ||
393 | bdev = blkdev_get_by_dev(vbd->pdevice, vbd->readonly ? | |
394 | FMODE_READ : FMODE_WRITE, NULL); | |
395 | ||
396 | if (IS_ERR(bdev)) { | |
77387b82 | 397 | pr_warn("xen_vbd_create: device %08x could not be opened\n", |
42c7841d KRW |
398 | vbd->pdevice); |
399 | return -ENOENT; | |
400 | } | |
401 | ||
402 | vbd->bdev = bdev; | |
42c7841d | 403 | if (vbd->bdev->bd_disk == NULL) { |
77387b82 | 404 | pr_warn("xen_vbd_create: device %08x doesn't exist\n", |
42c7841d | 405 | vbd->pdevice); |
3d814731 | 406 | xen_vbd_free(vbd); |
42c7841d KRW |
407 | return -ENOENT; |
408 | } | |
6464920a | 409 | vbd->size = vbd_sz(vbd); |
42c7841d KRW |
410 | |
411 | if (vbd->bdev->bd_disk->flags & GENHD_FL_CD || cdrom) | |
412 | vbd->type |= VDISK_CDROM; | |
413 | if (vbd->bdev->bd_disk->flags & GENHD_FL_REMOVABLE) | |
414 | vbd->type |= VDISK_REMOVABLE; | |
415 | ||
24f567f9 KRW |
416 | q = bdev_get_queue(bdev); |
417 | if (q && q->flush_flags) | |
418 | vbd->flush_support = true; | |
419 | ||
5ea42986 KRW |
420 | if (q && blk_queue_secdiscard(q)) |
421 | vbd->discard_secure = true; | |
422 | ||
77387b82 | 423 | pr_debug("Successful creation of handle=%04x (dom=%u)\n", |
42c7841d KRW |
424 | handle, blkif->domid); |
425 | return 0; | |
426 | } | |
8b6bf747 | 427 | static int xen_blkbk_remove(struct xenbus_device *dev) |
4d05a28d | 428 | { |
5cf6e4f6 | 429 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
4d05a28d | 430 | |
77387b82 | 431 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); |
4d05a28d KRW |
432 | |
433 | if (be->major || be->minor) | |
434 | xenvbd_sysfs_delif(dev); | |
435 | ||
436 | if (be->backend_watch.node) { | |
437 | unregister_xenbus_watch(&be->backend_watch); | |
438 | kfree(be->backend_watch.node); | |
439 | be->backend_watch.node = NULL; | |
440 | } | |
441 | ||
814d04e7 VP |
442 | dev_set_drvdata(&dev->dev, NULL); |
443 | ||
4d05a28d | 444 | if (be->blkif) { |
8b6bf747 | 445 | xen_blkif_disconnect(be->blkif); |
814d04e7 | 446 | xen_blkif_put(be->blkif); |
4d05a28d KRW |
447 | } |
448 | ||
9d092603 | 449 | kfree(be->mode); |
4d05a28d | 450 | kfree(be); |
4d05a28d KRW |
451 | return 0; |
452 | } | |
453 | ||
24f567f9 KRW |
454 | int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt, |
455 | struct backend_info *be, int state) | |
4d05a28d KRW |
456 | { |
457 | struct xenbus_device *dev = be->dev; | |
458 | int err; | |
459 | ||
24f567f9 | 460 | err = xenbus_printf(xbt, dev->nodename, "feature-flush-cache", |
4d05a28d KRW |
461 | "%d", state); |
462 | if (err) | |
3389bb8b | 463 | dev_warn(&dev->dev, "writing feature-flush-cache (%d)", err); |
4d05a28d KRW |
464 | |
465 | return err; | |
466 | } | |
467 | ||
3389bb8b | 468 | static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be) |
b3cb0d6a LD |
469 | { |
470 | struct xenbus_device *dev = be->dev; | |
471 | struct xen_blkif *blkif = be->blkif; | |
b3cb0d6a | 472 | int err; |
c926b701 | 473 | int state = 0, discard_enable; |
4dae7670 KRW |
474 | struct block_device *bdev = be->blkif->vbd.bdev; |
475 | struct request_queue *q = bdev_get_queue(bdev); | |
476 | ||
c926b701 OH |
477 | err = xenbus_scanf(XBT_NIL, dev->nodename, "discard-enable", "%d", |
478 | &discard_enable); | |
479 | if (err == 1 && !discard_enable) | |
480 | return; | |
481 | ||
4dae7670 KRW |
482 | if (blk_queue_discard(q)) { |
483 | err = xenbus_printf(xbt, dev->nodename, | |
484 | "discard-granularity", "%u", | |
485 | q->limits.discard_granularity); | |
486 | if (err) { | |
3389bb8b KRW |
487 | dev_warn(&dev->dev, "writing discard-granularity (%d)", err); |
488 | return; | |
4dae7670 KRW |
489 | } |
490 | err = xenbus_printf(xbt, dev->nodename, | |
491 | "discard-alignment", "%u", | |
492 | q->limits.discard_alignment); | |
493 | if (err) { | |
3389bb8b KRW |
494 | dev_warn(&dev->dev, "writing discard-alignment (%d)", err); |
495 | return; | |
b3cb0d6a | 496 | } |
4dae7670 KRW |
497 | state = 1; |
498 | /* Optional. */ | |
499 | err = xenbus_printf(xbt, dev->nodename, | |
500 | "discard-secure", "%d", | |
501 | blkif->vbd.discard_secure); | |
502 | if (err) { | |
a71e23d9 | 503 | dev_warn(&dev->dev, "writing discard-secure (%d)", err); |
3389bb8b | 504 | return; |
b3cb0d6a | 505 | } |
b3cb0d6a | 506 | } |
b3cb0d6a LD |
507 | err = xenbus_printf(xbt, dev->nodename, "feature-discard", |
508 | "%d", state); | |
509 | if (err) | |
3389bb8b | 510 | dev_warn(&dev->dev, "writing feature-discard (%d)", err); |
b3cb0d6a | 511 | } |
29bde093 KRW |
512 | int xen_blkbk_barrier(struct xenbus_transaction xbt, |
513 | struct backend_info *be, int state) | |
514 | { | |
515 | struct xenbus_device *dev = be->dev; | |
516 | int err; | |
517 | ||
518 | err = xenbus_printf(xbt, dev->nodename, "feature-barrier", | |
519 | "%d", state); | |
520 | if (err) | |
3389bb8b | 521 | dev_warn(&dev->dev, "writing feature-barrier (%d)", err); |
29bde093 KRW |
522 | |
523 | return err; | |
524 | } | |
b3cb0d6a | 525 | |
01f37f2d | 526 | /* |
4d05a28d KRW |
527 | * Entry point to this code when a new device is created. Allocate the basic |
528 | * structures, and watch the store waiting for the hotplug scripts to tell us | |
529 | * the device's physical major and minor numbers. Switch to InitWait. | |
530 | */ | |
8b6bf747 KRW |
531 | static int xen_blkbk_probe(struct xenbus_device *dev, |
532 | const struct xenbus_device_id *id) | |
4d05a28d KRW |
533 | { |
534 | int err; | |
535 | struct backend_info *be = kzalloc(sizeof(struct backend_info), | |
536 | GFP_KERNEL); | |
77387b82 TC |
537 | |
538 | /* match the pr_debug in xen_blkbk_remove */ | |
539 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); | |
540 | ||
4d05a28d KRW |
541 | if (!be) { |
542 | xenbus_dev_fatal(dev, -ENOMEM, | |
543 | "allocating backend structure"); | |
544 | return -ENOMEM; | |
545 | } | |
546 | be->dev = dev; | |
5cf6e4f6 | 547 | dev_set_drvdata(&dev->dev, be); |
4d05a28d | 548 | |
8b6bf747 | 549 | be->blkif = xen_blkif_alloc(dev->otherend_id); |
4d05a28d KRW |
550 | if (IS_ERR(be->blkif)) { |
551 | err = PTR_ERR(be->blkif); | |
552 | be->blkif = NULL; | |
553 | xenbus_dev_fatal(dev, err, "creating block interface"); | |
554 | goto fail; | |
555 | } | |
556 | ||
557 | /* setup back pointer */ | |
558 | be->blkif->be = be; | |
559 | ||
88122933 JF |
560 | err = xenbus_watch_pathfmt(dev, &be->backend_watch, backend_changed, |
561 | "%s/%s", dev->nodename, "physical-device"); | |
4d05a28d KRW |
562 | if (err) |
563 | goto fail; | |
564 | ||
86839c56 BL |
565 | err = xenbus_printf(XBT_NIL, dev->nodename, "max-ring-page-order", "%u", |
566 | xen_blkif_max_ring_order); | |
567 | if (err) | |
568 | pr_warn("%s write out 'max-ring-page-order' failed\n", __func__); | |
569 | ||
4d05a28d KRW |
570 | err = xenbus_switch_state(dev, XenbusStateInitWait); |
571 | if (err) | |
572 | goto fail; | |
573 | ||
574 | return 0; | |
575 | ||
576 | fail: | |
77387b82 | 577 | pr_warn("%s failed\n", __func__); |
8b6bf747 | 578 | xen_blkbk_remove(dev); |
4d05a28d KRW |
579 | return err; |
580 | } | |
581 | ||
582 | ||
01f37f2d | 583 | /* |
4d05a28d KRW |
584 | * Callback received when the hotplug scripts have placed the physical-device |
585 | * node. Read it and the mode node, and create a vbd. If the frontend is | |
586 | * ready, connect. | |
587 | */ | |
588 | static void backend_changed(struct xenbus_watch *watch, | |
589 | const char **vec, unsigned int len) | |
590 | { | |
591 | int err; | |
592 | unsigned major; | |
593 | unsigned minor; | |
594 | struct backend_info *be | |
595 | = container_of(watch, struct backend_info, backend_watch); | |
596 | struct xenbus_device *dev = be->dev; | |
597 | int cdrom = 0; | |
9d092603 | 598 | unsigned long handle; |
4d05a28d KRW |
599 | char *device_type; |
600 | ||
77387b82 | 601 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); |
4d05a28d KRW |
602 | |
603 | err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x", | |
604 | &major, &minor); | |
605 | if (XENBUS_EXIST_ERR(err)) { | |
01f37f2d KRW |
606 | /* |
607 | * Since this watch will fire once immediately after it is | |
608 | * registered, we expect this. Ignore it, and wait for the | |
609 | * hotplug scripts. | |
610 | */ | |
4d05a28d KRW |
611 | return; |
612 | } | |
613 | if (err != 2) { | |
614 | xenbus_dev_fatal(dev, err, "reading physical-device"); | |
615 | return; | |
616 | } | |
617 | ||
9d092603 JB |
618 | if (be->major | be->minor) { |
619 | if (be->major != major || be->minor != minor) | |
77387b82 | 620 | pr_warn("changing physical device (from %x:%x to %x:%x) not supported.\n", |
9d092603 | 621 | be->major, be->minor, major, minor); |
4d05a28d KRW |
622 | return; |
623 | } | |
624 | ||
625 | be->mode = xenbus_read(XBT_NIL, dev->nodename, "mode", NULL); | |
626 | if (IS_ERR(be->mode)) { | |
627 | err = PTR_ERR(be->mode); | |
628 | be->mode = NULL; | |
629 | xenbus_dev_fatal(dev, err, "reading mode"); | |
630 | return; | |
631 | } | |
632 | ||
633 | device_type = xenbus_read(XBT_NIL, dev->otherend, "device-type", NULL); | |
634 | if (!IS_ERR(device_type)) { | |
635 | cdrom = strcmp(device_type, "cdrom") == 0; | |
636 | kfree(device_type); | |
637 | } | |
638 | ||
9d092603 | 639 | /* Front end dir is a number, which is used as the handle. */ |
bb8e0e84 | 640 | err = kstrtoul(strrchr(dev->otherend, '/') + 1, 0, &handle); |
9d092603 JB |
641 | if (err) |
642 | return; | |
4d05a28d | 643 | |
9d092603 JB |
644 | be->major = major; |
645 | be->minor = minor; | |
4d05a28d | 646 | |
9d092603 JB |
647 | err = xen_vbd_create(be->blkif, handle, major, minor, |
648 | !strchr(be->mode, 'w'), cdrom); | |
4d05a28d | 649 | |
9d092603 JB |
650 | if (err) |
651 | xenbus_dev_fatal(dev, err, "creating vbd structure"); | |
652 | else { | |
4d05a28d KRW |
653 | err = xenvbd_sysfs_addif(dev); |
654 | if (err) { | |
3d814731 | 655 | xen_vbd_free(&be->blkif->vbd); |
4d05a28d | 656 | xenbus_dev_fatal(dev, err, "creating sysfs entries"); |
4d05a28d | 657 | } |
9d092603 | 658 | } |
4d05a28d | 659 | |
9d092603 JB |
660 | if (err) { |
661 | kfree(be->mode); | |
662 | be->mode = NULL; | |
663 | be->major = 0; | |
664 | be->minor = 0; | |
665 | } else { | |
4d05a28d | 666 | /* We're potentially connected now */ |
8b6bf747 | 667 | xen_update_blkif_status(be->blkif); |
4d05a28d KRW |
668 | } |
669 | } | |
670 | ||
671 | ||
01f37f2d | 672 | /* |
4d05a28d KRW |
673 | * Callback received when the frontend's state changes. |
674 | */ | |
675 | static void frontend_changed(struct xenbus_device *dev, | |
676 | enum xenbus_state frontend_state) | |
677 | { | |
5cf6e4f6 | 678 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
4d05a28d KRW |
679 | int err; |
680 | ||
77387b82 | 681 | pr_debug("%s %p %s\n", __func__, dev, xenbus_strstate(frontend_state)); |
4d05a28d KRW |
682 | |
683 | switch (frontend_state) { | |
684 | case XenbusStateInitialising: | |
685 | if (dev->state == XenbusStateClosed) { | |
77387b82 | 686 | pr_info("%s: prepare for reconnect\n", dev->nodename); |
4d05a28d KRW |
687 | xenbus_switch_state(dev, XenbusStateInitWait); |
688 | } | |
689 | break; | |
690 | ||
691 | case XenbusStateInitialised: | |
692 | case XenbusStateConnected: | |
01f37f2d KRW |
693 | /* |
694 | * Ensure we connect even when two watches fire in | |
42b2aa86 | 695 | * close succession and we miss the intermediate value |
01f37f2d KRW |
696 | * of frontend_state. |
697 | */ | |
4d05a28d KRW |
698 | if (dev->state == XenbusStateConnected) |
699 | break; | |
700 | ||
01f37f2d KRW |
701 | /* |
702 | * Enforce precondition before potential leak point. | |
1bc05b0a | 703 | * xen_blkif_disconnect() is idempotent. |
313d7b00 | 704 | */ |
814d04e7 VP |
705 | err = xen_blkif_disconnect(be->blkif); |
706 | if (err) { | |
707 | xenbus_dev_fatal(dev, err, "pending I/O"); | |
708 | break; | |
709 | } | |
313d7b00 | 710 | |
4d05a28d KRW |
711 | err = connect_ring(be); |
712 | if (err) | |
713 | break; | |
8b6bf747 | 714 | xen_update_blkif_status(be->blkif); |
4d05a28d KRW |
715 | break; |
716 | ||
717 | case XenbusStateClosing: | |
4d05a28d KRW |
718 | xenbus_switch_state(dev, XenbusStateClosing); |
719 | break; | |
720 | ||
721 | case XenbusStateClosed: | |
6f5986bc | 722 | xen_blkif_disconnect(be->blkif); |
4d05a28d KRW |
723 | xenbus_switch_state(dev, XenbusStateClosed); |
724 | if (xenbus_dev_is_online(dev)) | |
725 | break; | |
726 | /* fall through if not online */ | |
727 | case XenbusStateUnknown: | |
1bc05b0a | 728 | /* implies xen_blkif_disconnect() via xen_blkbk_remove() */ |
4d05a28d KRW |
729 | device_unregister(&dev->dev); |
730 | break; | |
731 | ||
732 | default: | |
733 | xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", | |
734 | frontend_state); | |
735 | break; | |
736 | } | |
737 | } | |
738 | ||
739 | ||
740 | /* ** Connection ** */ | |
741 | ||
742 | ||
01f37f2d | 743 | /* |
4d05a28d KRW |
744 | * Write the physical details regarding the block device to the store, and |
745 | * switch to Connected state. | |
746 | */ | |
747 | static void connect(struct backend_info *be) | |
748 | { | |
749 | struct xenbus_transaction xbt; | |
750 | int err; | |
751 | struct xenbus_device *dev = be->dev; | |
752 | ||
77387b82 | 753 | pr_debug("%s %s\n", __func__, dev->otherend); |
4d05a28d KRW |
754 | |
755 | /* Supply the information about the device the frontend needs */ | |
756 | again: | |
757 | err = xenbus_transaction_start(&xbt); | |
758 | if (err) { | |
759 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
760 | return; | |
761 | } | |
762 | ||
3389bb8b KRW |
763 | /* If we can't advertise it is OK. */ |
764 | xen_blkbk_flush_diskcache(xbt, be, be->blkif->vbd.flush_support); | |
4d05a28d | 765 | |
3389bb8b | 766 | xen_blkbk_discard(xbt, be); |
b3cb0d6a | 767 | |
3389bb8b | 768 | xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support); |
29bde093 | 769 | |
0a8704a5 RPM |
770 | err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u", 1); |
771 | if (err) { | |
772 | xenbus_dev_fatal(dev, err, "writing %s/feature-persistent", | |
773 | dev->nodename); | |
774 | goto abort; | |
775 | } | |
402b27f9 RPM |
776 | err = xenbus_printf(xbt, dev->nodename, "feature-max-indirect-segments", "%u", |
777 | MAX_INDIRECT_SEGMENTS); | |
778 | if (err) | |
779 | dev_warn(&dev->dev, "writing %s/feature-max-indirect-segments (%d)", | |
780 | dev->nodename, err); | |
0a8704a5 | 781 | |
4d05a28d | 782 | err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu", |
42c7841d | 783 | (unsigned long long)vbd_sz(&be->blkif->vbd)); |
4d05a28d KRW |
784 | if (err) { |
785 | xenbus_dev_fatal(dev, err, "writing %s/sectors", | |
786 | dev->nodename); | |
787 | goto abort; | |
788 | } | |
789 | ||
790 | /* FIXME: use a typename instead */ | |
791 | err = xenbus_printf(xbt, dev->nodename, "info", "%u", | |
42c7841d KRW |
792 | be->blkif->vbd.type | |
793 | (be->blkif->vbd.readonly ? VDISK_READONLY : 0)); | |
4d05a28d KRW |
794 | if (err) { |
795 | xenbus_dev_fatal(dev, err, "writing %s/info", | |
796 | dev->nodename); | |
797 | goto abort; | |
798 | } | |
799 | err = xenbus_printf(xbt, dev->nodename, "sector-size", "%lu", | |
42c7841d KRW |
800 | (unsigned long) |
801 | bdev_logical_block_size(be->blkif->vbd.bdev)); | |
4d05a28d KRW |
802 | if (err) { |
803 | xenbus_dev_fatal(dev, err, "writing %s/sector-size", | |
804 | dev->nodename); | |
805 | goto abort; | |
806 | } | |
7c4d7d71 SB |
807 | err = xenbus_printf(xbt, dev->nodename, "physical-sector-size", "%u", |
808 | bdev_physical_block_size(be->blkif->vbd.bdev)); | |
809 | if (err) | |
810 | xenbus_dev_error(dev, err, "writing %s/physical-sector-size", | |
811 | dev->nodename); | |
4d05a28d KRW |
812 | |
813 | err = xenbus_transaction_end(xbt, 0); | |
814 | if (err == -EAGAIN) | |
815 | goto again; | |
816 | if (err) | |
817 | xenbus_dev_fatal(dev, err, "ending transaction"); | |
818 | ||
819 | err = xenbus_switch_state(dev, XenbusStateConnected); | |
820 | if (err) | |
08b8bfc1 | 821 | xenbus_dev_fatal(dev, err, "%s: switching to Connected state", |
4d05a28d KRW |
822 | dev->nodename); |
823 | ||
824 | return; | |
825 | abort: | |
826 | xenbus_transaction_end(xbt, 1); | |
827 | } | |
828 | ||
829 | ||
830 | static int connect_ring(struct backend_info *be) | |
831 | { | |
832 | struct xenbus_device *dev = be->dev; | |
9cce2914 | 833 | unsigned int ring_ref[XENBUS_MAX_RING_GRANTS]; |
86839c56 | 834 | unsigned int evtchn, nr_grefs, ring_page_order; |
0a8704a5 | 835 | unsigned int pers_grants; |
4d05a28d | 836 | char protocol[64] = ""; |
69b91ede BL |
837 | struct pending_req *req, *n; |
838 | int err, i, j; | |
59795700 | 839 | struct xen_blkif_ring *ring = &be->blkif->ring; |
4d05a28d | 840 | |
77387b82 | 841 | pr_debug("%s %s\n", __func__, dev->otherend); |
4d05a28d | 842 | |
86839c56 BL |
843 | err = xenbus_scanf(XBT_NIL, dev->otherend, "event-channel", "%u", |
844 | &evtchn); | |
845 | if (err != 1) { | |
846 | err = -EINVAL; | |
847 | xenbus_dev_fatal(dev, err, "reading %s/event-channel", | |
4d05a28d KRW |
848 | dev->otherend); |
849 | return err; | |
850 | } | |
86839c56 BL |
851 | pr_info("event-channel %u\n", evtchn); |
852 | ||
853 | err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-page-order", "%u", | |
854 | &ring_page_order); | |
855 | if (err != 1) { | |
856 | err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", | |
857 | "%u", &ring_ref[0]); | |
858 | if (err != 1) { | |
859 | err = -EINVAL; | |
860 | xenbus_dev_fatal(dev, err, "reading %s/ring-ref", | |
861 | dev->otherend); | |
862 | return err; | |
863 | } | |
864 | nr_grefs = 1; | |
865 | pr_info("%s:using single page: ring-ref %d\n", dev->otherend, | |
866 | ring_ref[0]); | |
867 | } else { | |
868 | unsigned int i; | |
869 | ||
870 | if (ring_page_order > xen_blkif_max_ring_order) { | |
871 | err = -EINVAL; | |
872 | xenbus_dev_fatal(dev, err, "%s/request %d ring page order exceed max:%d", | |
873 | dev->otherend, ring_page_order, | |
874 | xen_blkif_max_ring_order); | |
875 | return err; | |
876 | } | |
877 | ||
878 | nr_grefs = 1 << ring_page_order; | |
879 | for (i = 0; i < nr_grefs; i++) { | |
880 | char ring_ref_name[RINGREF_NAME_LEN]; | |
881 | ||
882 | snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); | |
883 | err = xenbus_scanf(XBT_NIL, dev->otherend, ring_ref_name, | |
884 | "%u", &ring_ref[i]); | |
885 | if (err != 1) { | |
886 | err = -EINVAL; | |
887 | xenbus_dev_fatal(dev, err, "reading %s/%s", | |
888 | dev->otherend, ring_ref_name); | |
889 | return err; | |
890 | } | |
891 | pr_info("ring-ref%u: %u\n", i, ring_ref[i]); | |
892 | } | |
893 | } | |
4d05a28d | 894 | |
b042a3ca | 895 | be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT; |
4d05a28d KRW |
896 | err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", |
897 | "%63s", protocol, NULL); | |
898 | if (err) | |
b042a3ca | 899 | strcpy(protocol, "unspecified, assuming default"); |
4d05a28d KRW |
900 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) |
901 | be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; | |
902 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) | |
903 | be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_32; | |
904 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_64)) | |
905 | be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64; | |
906 | else { | |
907 | xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol); | |
908 | return -1; | |
909 | } | |
0a8704a5 | 910 | err = xenbus_gather(XBT_NIL, dev->otherend, |
cb5bd4d1 | 911 | "feature-persistent", "%u", |
0a8704a5 RPM |
912 | &pers_grants, NULL); |
913 | if (err) | |
914 | pers_grants = 0; | |
915 | ||
916 | be->blkif->vbd.feature_gnt_persistent = pers_grants; | |
917 | be->blkif->vbd.overflow_max_grants = 0; | |
86839c56 | 918 | be->blkif->nr_ring_pages = nr_grefs; |
0a8704a5 | 919 | |
86839c56 BL |
920 | pr_info("ring-pages:%d, event-channel %d, protocol %d (%s) %s\n", |
921 | nr_grefs, evtchn, be->blkif->blk_protocol, protocol, | |
0a8704a5 | 922 | pers_grants ? "persistent grants" : ""); |
4d05a28d | 923 | |
86839c56 | 924 | for (i = 0; i < nr_grefs * XEN_BLKIF_REQS_PER_PAGE; i++) { |
69b91ede BL |
925 | req = kzalloc(sizeof(*req), GFP_KERNEL); |
926 | if (!req) | |
927 | goto fail; | |
59795700 | 928 | list_add_tail(&req->free_list, &ring->pending_free); |
69b91ede BL |
929 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { |
930 | req->segments[j] = kzalloc(sizeof(*req->segments[0]), GFP_KERNEL); | |
931 | if (!req->segments[j]) | |
932 | goto fail; | |
933 | } | |
934 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) { | |
935 | req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]), | |
936 | GFP_KERNEL); | |
937 | if (!req->indirect_pages[j]) | |
938 | goto fail; | |
939 | } | |
940 | } | |
941 | ||
4d05a28d | 942 | /* Map the shared frame, irq etc. */ |
59795700 | 943 | err = xen_blkif_map(ring, ring_ref, nr_grefs, evtchn); |
4d05a28d | 944 | if (err) { |
86839c56 | 945 | xenbus_dev_fatal(dev, err, "mapping ring-ref port %u", evtchn); |
4d05a28d KRW |
946 | return err; |
947 | } | |
948 | ||
949 | return 0; | |
69b91ede BL |
950 | |
951 | fail: | |
59795700 | 952 | list_for_each_entry_safe(req, n, &ring->pending_free, free_list) { |
69b91ede BL |
953 | list_del(&req->free_list); |
954 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { | |
955 | if (!req->segments[j]) | |
956 | break; | |
957 | kfree(req->segments[j]); | |
958 | } | |
959 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) { | |
960 | if (!req->indirect_pages[j]) | |
961 | break; | |
962 | kfree(req->indirect_pages[j]); | |
963 | } | |
964 | kfree(req); | |
965 | } | |
966 | return -ENOMEM; | |
4d05a28d KRW |
967 | } |
968 | ||
8b6bf747 | 969 | static const struct xenbus_device_id xen_blkbk_ids[] = { |
4d05a28d KRW |
970 | { "vbd" }, |
971 | { "" } | |
972 | }; | |
973 | ||
95afae48 DV |
974 | static struct xenbus_driver xen_blkbk_driver = { |
975 | .ids = xen_blkbk_ids, | |
8b6bf747 KRW |
976 | .probe = xen_blkbk_probe, |
977 | .remove = xen_blkbk_remove, | |
4d05a28d | 978 | .otherend_changed = frontend_changed |
95afae48 | 979 | }; |
4d05a28d | 980 | |
8b6bf747 | 981 | int xen_blkif_xenbus_init(void) |
4d05a28d | 982 | { |
73db144b | 983 | return xenbus_register_backend(&xen_blkbk_driver); |
4d05a28d | 984 | } |