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) | |
28 | ||
d6091b21 | 29 | struct backend_info { |
01f37f2d | 30 | struct xenbus_device *dev; |
51854322 | 31 | struct xen_blkif *blkif; |
01f37f2d KRW |
32 | struct xenbus_watch backend_watch; |
33 | unsigned major; | |
34 | unsigned minor; | |
35 | char *mode; | |
4d05a28d KRW |
36 | }; |
37 | ||
8b6bf747 | 38 | static struct kmem_cache *xen_blkif_cachep; |
4d05a28d KRW |
39 | static void connect(struct backend_info *); |
40 | static int connect_ring(struct backend_info *); | |
41 | static void backend_changed(struct xenbus_watch *, const char **, | |
42 | unsigned int); | |
814d04e7 VP |
43 | static void xen_blkif_free(struct xen_blkif *blkif); |
44 | static void xen_vbd_free(struct xen_vbd *vbd); | |
4d05a28d | 45 | |
8b6bf747 | 46 | struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be) |
98e036a3 JF |
47 | { |
48 | return be->dev; | |
49 | } | |
50 | ||
814d04e7 VP |
51 | /* |
52 | * The last request could free the device from softirq context and | |
53 | * xen_blkif_free() can sleep. | |
54 | */ | |
55 | static void xen_blkif_deferred_free(struct work_struct *work) | |
56 | { | |
57 | struct xen_blkif *blkif; | |
58 | ||
59 | blkif = container_of(work, struct xen_blkif, free_work); | |
60 | xen_blkif_free(blkif); | |
61 | } | |
62 | ||
30fd1502 | 63 | static int blkback_name(struct xen_blkif *blkif, char *buf) |
4d05a28d KRW |
64 | { |
65 | char *devpath, *devname; | |
66 | struct xenbus_device *dev = blkif->be->dev; | |
67 | ||
68 | devpath = xenbus_read(XBT_NIL, dev->nodename, "dev", NULL); | |
69 | if (IS_ERR(devpath)) | |
70 | return PTR_ERR(devpath); | |
71 | ||
d6091b21 KRW |
72 | devname = strstr(devpath, "/dev/"); |
73 | if (devname != NULL) | |
4d05a28d KRW |
74 | devname += strlen("/dev/"); |
75 | else | |
76 | devname = devpath; | |
77 | ||
1375590d | 78 | snprintf(buf, BLKBACK_NAME_LEN, "blkback.%d.%s", blkif->domid, devname); |
4d05a28d KRW |
79 | kfree(devpath); |
80 | ||
81 | return 0; | |
82 | } | |
83 | ||
30fd1502 | 84 | static void xen_update_blkif_status(struct xen_blkif *blkif) |
4d05a28d KRW |
85 | { |
86 | int err; | |
1375590d | 87 | char name[BLKBACK_NAME_LEN]; |
4d05a28d KRW |
88 | |
89 | /* Not ready to connect? */ | |
90 | if (!blkif->irq || !blkif->vbd.bdev) | |
91 | return; | |
92 | ||
93 | /* Already connected? */ | |
94 | if (blkif->be->dev->state == XenbusStateConnected) | |
95 | return; | |
96 | ||
97 | /* Attempt to connect: exit if we fail to. */ | |
98 | connect(blkif->be); | |
99 | if (blkif->be->dev->state != XenbusStateConnected) | |
100 | return; | |
101 | ||
102 | err = blkback_name(blkif, name); | |
103 | if (err) { | |
104 | xenbus_dev_error(blkif->be->dev, err, "get blkback dev name"); | |
105 | return; | |
106 | } | |
107 | ||
cbf46290 CL |
108 | err = filemap_write_and_wait(blkif->vbd.bdev->bd_inode->i_mapping); |
109 | if (err) { | |
110 | xenbus_dev_error(blkif->be->dev, err, "block flush"); | |
111 | return; | |
112 | } | |
113 | invalidate_inode_pages2(blkif->vbd.bdev->bd_inode->i_mapping); | |
114 | ||
f170168b | 115 | blkif->xenblkd = kthread_run(xen_blkif_schedule, blkif, "%s", name); |
4d05a28d KRW |
116 | if (IS_ERR(blkif->xenblkd)) { |
117 | err = PTR_ERR(blkif->xenblkd); | |
118 | blkif->xenblkd = NULL; | |
119 | xenbus_dev_error(blkif->be->dev, err, "start xenblkd"); | |
3f3aad5e | 120 | return; |
4d05a28d KRW |
121 | } |
122 | } | |
123 | ||
30fd1502 | 124 | static struct xen_blkif *xen_blkif_alloc(domid_t domid) |
ee9ff853 | 125 | { |
30fd1502 | 126 | struct xen_blkif *blkif; |
ee9ff853 | 127 | |
402b27f9 | 128 | BUILD_BUG_ON(MAX_INDIRECT_PAGES > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST); |
ee9ff853 | 129 | |
654dbef2 | 130 | blkif = kmem_cache_zalloc(xen_blkif_cachep, GFP_KERNEL); |
ee9ff853 KRW |
131 | if (!blkif) |
132 | return ERR_PTR(-ENOMEM); | |
133 | ||
ee9ff853 KRW |
134 | blkif->domid = domid; |
135 | spin_lock_init(&blkif->blk_ring_lock); | |
136 | atomic_set(&blkif->refcnt, 1); | |
137 | init_waitqueue_head(&blkif->wq); | |
29bde093 KRW |
138 | init_completion(&blkif->drain_complete); |
139 | atomic_set(&blkif->drain, 0); | |
ee9ff853 | 140 | blkif->st_print = jiffies; |
0a8704a5 | 141 | blkif->persistent_gnts.rb_node = NULL; |
c6cc142d RPM |
142 | spin_lock_init(&blkif->free_pages_lock); |
143 | INIT_LIST_HEAD(&blkif->free_pages); | |
ef753411 | 144 | INIT_LIST_HEAD(&blkif->persistent_purge_list); |
c6cc142d | 145 | blkif->free_pages_num = 0; |
3f3aad5e | 146 | atomic_set(&blkif->persistent_gnt_in_use, 0); |
c05f3e3c | 147 | atomic_set(&blkif->inflight, 0); |
abb97b8c | 148 | INIT_WORK(&blkif->persistent_purge_work, xen_blkbk_unmap_purged_grants); |
ee9ff853 | 149 | |
bf0720c4 | 150 | INIT_LIST_HEAD(&blkif->pending_free); |
814d04e7 | 151 | INIT_WORK(&blkif->free_work, xen_blkif_deferred_free); |
bf0720c4 RPM |
152 | spin_lock_init(&blkif->pending_free_lock); |
153 | init_waitqueue_head(&blkif->pending_free_wq); | |
8e3f8755 | 154 | init_waitqueue_head(&blkif->shutdown_wq); |
ee9ff853 KRW |
155 | |
156 | return blkif; | |
157 | } | |
158 | ||
ccc9d90a | 159 | static int xen_blkif_map(struct xen_blkif *blkif, grant_ref_t gref, |
8b6bf747 | 160 | unsigned int evtchn) |
ee9ff853 KRW |
161 | { |
162 | int err; | |
163 | ||
164 | /* Already connected through? */ | |
165 | if (blkif->irq) | |
166 | return 0; | |
167 | ||
ccc9d90a WL |
168 | err = xenbus_map_ring_valloc(blkif->be->dev, &gref, 1, |
169 | &blkif->blk_ring); | |
2d073846 | 170 | if (err < 0) |
ee9ff853 | 171 | return err; |
ee9ff853 KRW |
172 | |
173 | switch (blkif->blk_protocol) { | |
174 | case BLKIF_PROTOCOL_NATIVE: | |
175 | { | |
176 | struct blkif_sring *sring; | |
2d073846 | 177 | sring = (struct blkif_sring *)blkif->blk_ring; |
ee9ff853 KRW |
178 | BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE); |
179 | break; | |
180 | } | |
181 | case BLKIF_PROTOCOL_X86_32: | |
182 | { | |
183 | struct blkif_x86_32_sring *sring_x86_32; | |
2d073846 | 184 | sring_x86_32 = (struct blkif_x86_32_sring *)blkif->blk_ring; |
ee9ff853 KRW |
185 | BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE); |
186 | break; | |
187 | } | |
188 | case BLKIF_PROTOCOL_X86_64: | |
189 | { | |
190 | struct blkif_x86_64_sring *sring_x86_64; | |
2d073846 | 191 | sring_x86_64 = (struct blkif_x86_64_sring *)blkif->blk_ring; |
ee9ff853 KRW |
192 | BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE); |
193 | break; | |
194 | } | |
195 | default: | |
196 | BUG(); | |
197 | } | |
198 | ||
8b6bf747 KRW |
199 | err = bind_interdomain_evtchn_to_irqhandler(blkif->domid, evtchn, |
200 | xen_blkif_be_int, 0, | |
201 | "blkif-backend", blkif); | |
ee9ff853 | 202 | if (err < 0) { |
2d073846 | 203 | xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring); |
ee9ff853 KRW |
204 | blkif->blk_rings.common.sring = NULL; |
205 | return err; | |
206 | } | |
207 | blkif->irq = err; | |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
814d04e7 | 212 | static int xen_blkif_disconnect(struct xen_blkif *blkif) |
ee9ff853 KRW |
213 | { |
214 | if (blkif->xenblkd) { | |
215 | kthread_stop(blkif->xenblkd); | |
8e3f8755 | 216 | wake_up(&blkif->shutdown_wq); |
ee9ff853 KRW |
217 | blkif->xenblkd = NULL; |
218 | } | |
219 | ||
814d04e7 VP |
220 | /* The above kthread_stop() guarantees that at this point we |
221 | * don't have any discard_io or other_io requests. So, checking | |
222 | * for inflight IO is enough. | |
223 | */ | |
224 | if (atomic_read(&blkif->inflight) > 0) | |
225 | return -EBUSY; | |
ee9ff853 KRW |
226 | |
227 | if (blkif->irq) { | |
228 | unbind_from_irqhandler(blkif->irq, blkif); | |
229 | blkif->irq = 0; | |
230 | } | |
231 | ||
232 | if (blkif->blk_rings.common.sring) { | |
2d073846 | 233 | xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring); |
ee9ff853 KRW |
234 | blkif->blk_rings.common.sring = NULL; |
235 | } | |
814d04e7 | 236 | |
12ea7296 VK |
237 | /* Remove all persistent grants and the cache of ballooned pages. */ |
238 | xen_blkbk_free_caches(blkif); | |
239 | ||
814d04e7 | 240 | return 0; |
ee9ff853 KRW |
241 | } |
242 | ||
2911758f | 243 | static void xen_blkif_free(struct xen_blkif *blkif) |
ee9ff853 | 244 | { |
bb642e83 RPM |
245 | struct pending_req *req, *n; |
246 | int i = 0, j; | |
bf0720c4 | 247 | |
814d04e7 VP |
248 | xen_blkif_disconnect(blkif); |
249 | xen_vbd_free(&blkif->vbd); | |
bf0720c4 | 250 | |
ef753411 RPM |
251 | /* Make sure everything is drained before shutting down */ |
252 | BUG_ON(blkif->persistent_gnt_c != 0); | |
253 | BUG_ON(atomic_read(&blkif->persistent_gnt_in_use) != 0); | |
254 | BUG_ON(blkif->free_pages_num != 0); | |
255 | BUG_ON(!list_empty(&blkif->persistent_purge_list)); | |
256 | BUG_ON(!list_empty(&blkif->free_pages)); | |
257 | BUG_ON(!RB_EMPTY_ROOT(&blkif->persistent_gnts)); | |
258 | ||
bf0720c4 | 259 | /* Check that there is no request in use */ |
bb642e83 RPM |
260 | list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) { |
261 | list_del(&req->free_list); | |
262 | ||
263 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) | |
264 | kfree(req->segments[j]); | |
265 | ||
266 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) | |
267 | kfree(req->indirect_pages[j]); | |
268 | ||
269 | kfree(req); | |
bf0720c4 | 270 | i++; |
bb642e83 RPM |
271 | } |
272 | ||
69b91ede | 273 | WARN_ON(i != XEN_BLKIF_REQS_PER_PAGE); |
bf0720c4 | 274 | |
8b6bf747 | 275 | kmem_cache_free(xen_blkif_cachep, blkif); |
ee9ff853 KRW |
276 | } |
277 | ||
8b6bf747 | 278 | int __init xen_blkif_interface_init(void) |
ee9ff853 | 279 | { |
8b6bf747 | 280 | xen_blkif_cachep = kmem_cache_create("blkif_cache", |
30fd1502 | 281 | sizeof(struct xen_blkif), |
8b6bf747 KRW |
282 | 0, 0, NULL); |
283 | if (!xen_blkif_cachep) | |
ee9ff853 KRW |
284 | return -ENOMEM; |
285 | ||
286 | return 0; | |
287 | } | |
4d05a28d | 288 | |
a1397fa3 | 289 | /* |
4d05a28d KRW |
290 | * sysfs interface for VBD I/O requests |
291 | */ | |
292 | ||
293 | #define VBD_SHOW(name, format, args...) \ | |
294 | static ssize_t show_##name(struct device *_dev, \ | |
295 | struct device_attribute *attr, \ | |
296 | char *buf) \ | |
297 | { \ | |
298 | struct xenbus_device *dev = to_xenbus_device(_dev); \ | |
5cf6e4f6 | 299 | struct backend_info *be = dev_get_drvdata(&dev->dev); \ |
4d05a28d KRW |
300 | \ |
301 | return sprintf(buf, format, ##args); \ | |
302 | } \ | |
303 | static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL) | |
304 | ||
986cacbd ZK |
305 | VBD_SHOW(oo_req, "%llu\n", be->blkif->st_oo_req); |
306 | VBD_SHOW(rd_req, "%llu\n", be->blkif->st_rd_req); | |
307 | VBD_SHOW(wr_req, "%llu\n", be->blkif->st_wr_req); | |
308 | VBD_SHOW(f_req, "%llu\n", be->blkif->st_f_req); | |
309 | VBD_SHOW(ds_req, "%llu\n", be->blkif->st_ds_req); | |
310 | VBD_SHOW(rd_sect, "%llu\n", be->blkif->st_rd_sect); | |
311 | VBD_SHOW(wr_sect, "%llu\n", be->blkif->st_wr_sect); | |
4d05a28d | 312 | |
3d814731 | 313 | static struct attribute *xen_vbdstat_attrs[] = { |
4d05a28d KRW |
314 | &dev_attr_oo_req.attr, |
315 | &dev_attr_rd_req.attr, | |
316 | &dev_attr_wr_req.attr, | |
24f567f9 | 317 | &dev_attr_f_req.attr, |
b3cb0d6a | 318 | &dev_attr_ds_req.attr, |
4d05a28d KRW |
319 | &dev_attr_rd_sect.attr, |
320 | &dev_attr_wr_sect.attr, | |
321 | NULL | |
322 | }; | |
323 | ||
3d814731 | 324 | static struct attribute_group xen_vbdstat_group = { |
4d05a28d | 325 | .name = "statistics", |
3d814731 | 326 | .attrs = xen_vbdstat_attrs, |
4d05a28d KRW |
327 | }; |
328 | ||
329 | VBD_SHOW(physical_device, "%x:%x\n", be->major, be->minor); | |
330 | VBD_SHOW(mode, "%s\n", be->mode); | |
331 | ||
2911758f | 332 | static int xenvbd_sysfs_addif(struct xenbus_device *dev) |
4d05a28d KRW |
333 | { |
334 | int error; | |
335 | ||
336 | error = device_create_file(&dev->dev, &dev_attr_physical_device); | |
d6091b21 | 337 | if (error) |
4d05a28d KRW |
338 | goto fail1; |
339 | ||
340 | error = device_create_file(&dev->dev, &dev_attr_mode); | |
341 | if (error) | |
342 | goto fail2; | |
343 | ||
3d814731 | 344 | error = sysfs_create_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
345 | if (error) |
346 | goto fail3; | |
347 | ||
348 | return 0; | |
349 | ||
3d814731 | 350 | fail3: sysfs_remove_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
351 | fail2: device_remove_file(&dev->dev, &dev_attr_mode); |
352 | fail1: device_remove_file(&dev->dev, &dev_attr_physical_device); | |
353 | return error; | |
354 | } | |
355 | ||
2911758f | 356 | static void xenvbd_sysfs_delif(struct xenbus_device *dev) |
4d05a28d | 357 | { |
3d814731 | 358 | sysfs_remove_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
359 | device_remove_file(&dev->dev, &dev_attr_mode); |
360 | device_remove_file(&dev->dev, &dev_attr_physical_device); | |
361 | } | |
362 | ||
42c7841d | 363 | |
3d814731 | 364 | static void xen_vbd_free(struct xen_vbd *vbd) |
42c7841d KRW |
365 | { |
366 | if (vbd->bdev) | |
367 | blkdev_put(vbd->bdev, vbd->readonly ? FMODE_READ : FMODE_WRITE); | |
368 | vbd->bdev = NULL; | |
369 | } | |
370 | ||
3d814731 KRW |
371 | static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle, |
372 | unsigned major, unsigned minor, int readonly, | |
373 | int cdrom) | |
42c7841d | 374 | { |
3d814731 | 375 | struct xen_vbd *vbd; |
42c7841d | 376 | struct block_device *bdev; |
24f567f9 | 377 | struct request_queue *q; |
42c7841d KRW |
378 | |
379 | vbd = &blkif->vbd; | |
380 | vbd->handle = handle; | |
381 | vbd->readonly = readonly; | |
382 | vbd->type = 0; | |
383 | ||
384 | vbd->pdevice = MKDEV(major, minor); | |
385 | ||
386 | bdev = blkdev_get_by_dev(vbd->pdevice, vbd->readonly ? | |
387 | FMODE_READ : FMODE_WRITE, NULL); | |
388 | ||
389 | if (IS_ERR(bdev)) { | |
77387b82 | 390 | pr_warn("xen_vbd_create: device %08x could not be opened\n", |
42c7841d KRW |
391 | vbd->pdevice); |
392 | return -ENOENT; | |
393 | } | |
394 | ||
395 | vbd->bdev = bdev; | |
42c7841d | 396 | if (vbd->bdev->bd_disk == NULL) { |
77387b82 | 397 | pr_warn("xen_vbd_create: device %08x doesn't exist\n", |
42c7841d | 398 | vbd->pdevice); |
3d814731 | 399 | xen_vbd_free(vbd); |
42c7841d KRW |
400 | return -ENOENT; |
401 | } | |
6464920a | 402 | vbd->size = vbd_sz(vbd); |
42c7841d KRW |
403 | |
404 | if (vbd->bdev->bd_disk->flags & GENHD_FL_CD || cdrom) | |
405 | vbd->type |= VDISK_CDROM; | |
406 | if (vbd->bdev->bd_disk->flags & GENHD_FL_REMOVABLE) | |
407 | vbd->type |= VDISK_REMOVABLE; | |
408 | ||
24f567f9 KRW |
409 | q = bdev_get_queue(bdev); |
410 | if (q && q->flush_flags) | |
411 | vbd->flush_support = true; | |
412 | ||
5ea42986 KRW |
413 | if (q && blk_queue_secdiscard(q)) |
414 | vbd->discard_secure = true; | |
415 | ||
77387b82 | 416 | pr_debug("Successful creation of handle=%04x (dom=%u)\n", |
42c7841d KRW |
417 | handle, blkif->domid); |
418 | return 0; | |
419 | } | |
8b6bf747 | 420 | static int xen_blkbk_remove(struct xenbus_device *dev) |
4d05a28d | 421 | { |
5cf6e4f6 | 422 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
4d05a28d | 423 | |
77387b82 | 424 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); |
4d05a28d KRW |
425 | |
426 | if (be->major || be->minor) | |
427 | xenvbd_sysfs_delif(dev); | |
428 | ||
429 | if (be->backend_watch.node) { | |
430 | unregister_xenbus_watch(&be->backend_watch); | |
431 | kfree(be->backend_watch.node); | |
432 | be->backend_watch.node = NULL; | |
433 | } | |
434 | ||
814d04e7 VP |
435 | dev_set_drvdata(&dev->dev, NULL); |
436 | ||
4d05a28d | 437 | if (be->blkif) { |
8b6bf747 | 438 | xen_blkif_disconnect(be->blkif); |
814d04e7 | 439 | xen_blkif_put(be->blkif); |
4d05a28d KRW |
440 | } |
441 | ||
9d092603 | 442 | kfree(be->mode); |
4d05a28d | 443 | kfree(be); |
4d05a28d KRW |
444 | return 0; |
445 | } | |
446 | ||
24f567f9 KRW |
447 | int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt, |
448 | struct backend_info *be, int state) | |
4d05a28d KRW |
449 | { |
450 | struct xenbus_device *dev = be->dev; | |
451 | int err; | |
452 | ||
24f567f9 | 453 | err = xenbus_printf(xbt, dev->nodename, "feature-flush-cache", |
4d05a28d KRW |
454 | "%d", state); |
455 | if (err) | |
3389bb8b | 456 | dev_warn(&dev->dev, "writing feature-flush-cache (%d)", err); |
4d05a28d KRW |
457 | |
458 | return err; | |
459 | } | |
460 | ||
3389bb8b | 461 | static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be) |
b3cb0d6a LD |
462 | { |
463 | struct xenbus_device *dev = be->dev; | |
464 | struct xen_blkif *blkif = be->blkif; | |
b3cb0d6a | 465 | int err; |
c926b701 | 466 | int state = 0, discard_enable; |
4dae7670 KRW |
467 | struct block_device *bdev = be->blkif->vbd.bdev; |
468 | struct request_queue *q = bdev_get_queue(bdev); | |
469 | ||
c926b701 OH |
470 | err = xenbus_scanf(XBT_NIL, dev->nodename, "discard-enable", "%d", |
471 | &discard_enable); | |
472 | if (err == 1 && !discard_enable) | |
473 | return; | |
474 | ||
4dae7670 KRW |
475 | if (blk_queue_discard(q)) { |
476 | err = xenbus_printf(xbt, dev->nodename, | |
477 | "discard-granularity", "%u", | |
478 | q->limits.discard_granularity); | |
479 | if (err) { | |
3389bb8b KRW |
480 | dev_warn(&dev->dev, "writing discard-granularity (%d)", err); |
481 | return; | |
4dae7670 KRW |
482 | } |
483 | err = xenbus_printf(xbt, dev->nodename, | |
484 | "discard-alignment", "%u", | |
485 | q->limits.discard_alignment); | |
486 | if (err) { | |
3389bb8b KRW |
487 | dev_warn(&dev->dev, "writing discard-alignment (%d)", err); |
488 | return; | |
b3cb0d6a | 489 | } |
4dae7670 KRW |
490 | state = 1; |
491 | /* Optional. */ | |
492 | err = xenbus_printf(xbt, dev->nodename, | |
493 | "discard-secure", "%d", | |
494 | blkif->vbd.discard_secure); | |
495 | if (err) { | |
a71e23d9 | 496 | dev_warn(&dev->dev, "writing discard-secure (%d)", err); |
3389bb8b | 497 | return; |
b3cb0d6a | 498 | } |
b3cb0d6a | 499 | } |
b3cb0d6a LD |
500 | err = xenbus_printf(xbt, dev->nodename, "feature-discard", |
501 | "%d", state); | |
502 | if (err) | |
3389bb8b | 503 | dev_warn(&dev->dev, "writing feature-discard (%d)", err); |
b3cb0d6a | 504 | } |
29bde093 KRW |
505 | int xen_blkbk_barrier(struct xenbus_transaction xbt, |
506 | struct backend_info *be, int state) | |
507 | { | |
508 | struct xenbus_device *dev = be->dev; | |
509 | int err; | |
510 | ||
511 | err = xenbus_printf(xbt, dev->nodename, "feature-barrier", | |
512 | "%d", state); | |
513 | if (err) | |
3389bb8b | 514 | dev_warn(&dev->dev, "writing feature-barrier (%d)", err); |
29bde093 KRW |
515 | |
516 | return err; | |
517 | } | |
b3cb0d6a | 518 | |
01f37f2d | 519 | /* |
4d05a28d KRW |
520 | * Entry point to this code when a new device is created. Allocate the basic |
521 | * structures, and watch the store waiting for the hotplug scripts to tell us | |
522 | * the device's physical major and minor numbers. Switch to InitWait. | |
523 | */ | |
8b6bf747 KRW |
524 | static int xen_blkbk_probe(struct xenbus_device *dev, |
525 | const struct xenbus_device_id *id) | |
4d05a28d KRW |
526 | { |
527 | int err; | |
528 | struct backend_info *be = kzalloc(sizeof(struct backend_info), | |
529 | GFP_KERNEL); | |
77387b82 TC |
530 | |
531 | /* match the pr_debug in xen_blkbk_remove */ | |
532 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); | |
533 | ||
4d05a28d KRW |
534 | if (!be) { |
535 | xenbus_dev_fatal(dev, -ENOMEM, | |
536 | "allocating backend structure"); | |
537 | return -ENOMEM; | |
538 | } | |
539 | be->dev = dev; | |
5cf6e4f6 | 540 | dev_set_drvdata(&dev->dev, be); |
4d05a28d | 541 | |
8b6bf747 | 542 | be->blkif = xen_blkif_alloc(dev->otherend_id); |
4d05a28d KRW |
543 | if (IS_ERR(be->blkif)) { |
544 | err = PTR_ERR(be->blkif); | |
545 | be->blkif = NULL; | |
546 | xenbus_dev_fatal(dev, err, "creating block interface"); | |
547 | goto fail; | |
548 | } | |
549 | ||
550 | /* setup back pointer */ | |
551 | be->blkif->be = be; | |
552 | ||
88122933 JF |
553 | err = xenbus_watch_pathfmt(dev, &be->backend_watch, backend_changed, |
554 | "%s/%s", dev->nodename, "physical-device"); | |
4d05a28d KRW |
555 | if (err) |
556 | goto fail; | |
557 | ||
558 | err = xenbus_switch_state(dev, XenbusStateInitWait); | |
559 | if (err) | |
560 | goto fail; | |
561 | ||
562 | return 0; | |
563 | ||
564 | fail: | |
77387b82 | 565 | pr_warn("%s failed\n", __func__); |
8b6bf747 | 566 | xen_blkbk_remove(dev); |
4d05a28d KRW |
567 | return err; |
568 | } | |
569 | ||
570 | ||
01f37f2d | 571 | /* |
4d05a28d KRW |
572 | * Callback received when the hotplug scripts have placed the physical-device |
573 | * node. Read it and the mode node, and create a vbd. If the frontend is | |
574 | * ready, connect. | |
575 | */ | |
576 | static void backend_changed(struct xenbus_watch *watch, | |
577 | const char **vec, unsigned int len) | |
578 | { | |
579 | int err; | |
580 | unsigned major; | |
581 | unsigned minor; | |
582 | struct backend_info *be | |
583 | = container_of(watch, struct backend_info, backend_watch); | |
584 | struct xenbus_device *dev = be->dev; | |
585 | int cdrom = 0; | |
9d092603 | 586 | unsigned long handle; |
4d05a28d KRW |
587 | char *device_type; |
588 | ||
77387b82 | 589 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); |
4d05a28d KRW |
590 | |
591 | err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x", | |
592 | &major, &minor); | |
593 | if (XENBUS_EXIST_ERR(err)) { | |
01f37f2d KRW |
594 | /* |
595 | * Since this watch will fire once immediately after it is | |
596 | * registered, we expect this. Ignore it, and wait for the | |
597 | * hotplug scripts. | |
598 | */ | |
4d05a28d KRW |
599 | return; |
600 | } | |
601 | if (err != 2) { | |
602 | xenbus_dev_fatal(dev, err, "reading physical-device"); | |
603 | return; | |
604 | } | |
605 | ||
9d092603 JB |
606 | if (be->major | be->minor) { |
607 | if (be->major != major || be->minor != minor) | |
77387b82 | 608 | pr_warn("changing physical device (from %x:%x to %x:%x) not supported.\n", |
9d092603 | 609 | be->major, be->minor, major, minor); |
4d05a28d KRW |
610 | return; |
611 | } | |
612 | ||
613 | be->mode = xenbus_read(XBT_NIL, dev->nodename, "mode", NULL); | |
614 | if (IS_ERR(be->mode)) { | |
615 | err = PTR_ERR(be->mode); | |
616 | be->mode = NULL; | |
617 | xenbus_dev_fatal(dev, err, "reading mode"); | |
618 | return; | |
619 | } | |
620 | ||
621 | device_type = xenbus_read(XBT_NIL, dev->otherend, "device-type", NULL); | |
622 | if (!IS_ERR(device_type)) { | |
623 | cdrom = strcmp(device_type, "cdrom") == 0; | |
624 | kfree(device_type); | |
625 | } | |
626 | ||
9d092603 | 627 | /* Front end dir is a number, which is used as the handle. */ |
bb8e0e84 | 628 | err = kstrtoul(strrchr(dev->otherend, '/') + 1, 0, &handle); |
9d092603 JB |
629 | if (err) |
630 | return; | |
4d05a28d | 631 | |
9d092603 JB |
632 | be->major = major; |
633 | be->minor = minor; | |
4d05a28d | 634 | |
9d092603 JB |
635 | err = xen_vbd_create(be->blkif, handle, major, minor, |
636 | !strchr(be->mode, 'w'), cdrom); | |
4d05a28d | 637 | |
9d092603 JB |
638 | if (err) |
639 | xenbus_dev_fatal(dev, err, "creating vbd structure"); | |
640 | else { | |
4d05a28d KRW |
641 | err = xenvbd_sysfs_addif(dev); |
642 | if (err) { | |
3d814731 | 643 | xen_vbd_free(&be->blkif->vbd); |
4d05a28d | 644 | xenbus_dev_fatal(dev, err, "creating sysfs entries"); |
4d05a28d | 645 | } |
9d092603 | 646 | } |
4d05a28d | 647 | |
9d092603 JB |
648 | if (err) { |
649 | kfree(be->mode); | |
650 | be->mode = NULL; | |
651 | be->major = 0; | |
652 | be->minor = 0; | |
653 | } else { | |
4d05a28d | 654 | /* We're potentially connected now */ |
8b6bf747 | 655 | xen_update_blkif_status(be->blkif); |
4d05a28d KRW |
656 | } |
657 | } | |
658 | ||
659 | ||
01f37f2d | 660 | /* |
4d05a28d KRW |
661 | * Callback received when the frontend's state changes. |
662 | */ | |
663 | static void frontend_changed(struct xenbus_device *dev, | |
664 | enum xenbus_state frontend_state) | |
665 | { | |
5cf6e4f6 | 666 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
4d05a28d KRW |
667 | int err; |
668 | ||
77387b82 | 669 | pr_debug("%s %p %s\n", __func__, dev, xenbus_strstate(frontend_state)); |
4d05a28d KRW |
670 | |
671 | switch (frontend_state) { | |
672 | case XenbusStateInitialising: | |
673 | if (dev->state == XenbusStateClosed) { | |
77387b82 | 674 | pr_info("%s: prepare for reconnect\n", dev->nodename); |
4d05a28d KRW |
675 | xenbus_switch_state(dev, XenbusStateInitWait); |
676 | } | |
677 | break; | |
678 | ||
679 | case XenbusStateInitialised: | |
680 | case XenbusStateConnected: | |
01f37f2d KRW |
681 | /* |
682 | * Ensure we connect even when two watches fire in | |
42b2aa86 | 683 | * close succession and we miss the intermediate value |
01f37f2d KRW |
684 | * of frontend_state. |
685 | */ | |
4d05a28d KRW |
686 | if (dev->state == XenbusStateConnected) |
687 | break; | |
688 | ||
01f37f2d KRW |
689 | /* |
690 | * Enforce precondition before potential leak point. | |
1bc05b0a | 691 | * xen_blkif_disconnect() is idempotent. |
313d7b00 | 692 | */ |
814d04e7 VP |
693 | err = xen_blkif_disconnect(be->blkif); |
694 | if (err) { | |
695 | xenbus_dev_fatal(dev, err, "pending I/O"); | |
696 | break; | |
697 | } | |
313d7b00 | 698 | |
4d05a28d KRW |
699 | err = connect_ring(be); |
700 | if (err) | |
701 | break; | |
8b6bf747 | 702 | xen_update_blkif_status(be->blkif); |
4d05a28d KRW |
703 | break; |
704 | ||
705 | case XenbusStateClosing: | |
4d05a28d KRW |
706 | xenbus_switch_state(dev, XenbusStateClosing); |
707 | break; | |
708 | ||
709 | case XenbusStateClosed: | |
6f5986bc | 710 | xen_blkif_disconnect(be->blkif); |
4d05a28d KRW |
711 | xenbus_switch_state(dev, XenbusStateClosed); |
712 | if (xenbus_dev_is_online(dev)) | |
713 | break; | |
714 | /* fall through if not online */ | |
715 | case XenbusStateUnknown: | |
1bc05b0a | 716 | /* implies xen_blkif_disconnect() via xen_blkbk_remove() */ |
4d05a28d KRW |
717 | device_unregister(&dev->dev); |
718 | break; | |
719 | ||
720 | default: | |
721 | xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", | |
722 | frontend_state); | |
723 | break; | |
724 | } | |
725 | } | |
726 | ||
727 | ||
728 | /* ** Connection ** */ | |
729 | ||
730 | ||
01f37f2d | 731 | /* |
4d05a28d KRW |
732 | * Write the physical details regarding the block device to the store, and |
733 | * switch to Connected state. | |
734 | */ | |
735 | static void connect(struct backend_info *be) | |
736 | { | |
737 | struct xenbus_transaction xbt; | |
738 | int err; | |
739 | struct xenbus_device *dev = be->dev; | |
740 | ||
77387b82 | 741 | pr_debug("%s %s\n", __func__, dev->otherend); |
4d05a28d KRW |
742 | |
743 | /* Supply the information about the device the frontend needs */ | |
744 | again: | |
745 | err = xenbus_transaction_start(&xbt); | |
746 | if (err) { | |
747 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
748 | return; | |
749 | } | |
750 | ||
3389bb8b KRW |
751 | /* If we can't advertise it is OK. */ |
752 | xen_blkbk_flush_diskcache(xbt, be, be->blkif->vbd.flush_support); | |
4d05a28d | 753 | |
3389bb8b | 754 | xen_blkbk_discard(xbt, be); |
b3cb0d6a | 755 | |
3389bb8b | 756 | xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support); |
29bde093 | 757 | |
0a8704a5 RPM |
758 | err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u", 1); |
759 | if (err) { | |
760 | xenbus_dev_fatal(dev, err, "writing %s/feature-persistent", | |
761 | dev->nodename); | |
762 | goto abort; | |
763 | } | |
402b27f9 RPM |
764 | err = xenbus_printf(xbt, dev->nodename, "feature-max-indirect-segments", "%u", |
765 | MAX_INDIRECT_SEGMENTS); | |
766 | if (err) | |
767 | dev_warn(&dev->dev, "writing %s/feature-max-indirect-segments (%d)", | |
768 | dev->nodename, err); | |
0a8704a5 | 769 | |
4d05a28d | 770 | err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu", |
42c7841d | 771 | (unsigned long long)vbd_sz(&be->blkif->vbd)); |
4d05a28d KRW |
772 | if (err) { |
773 | xenbus_dev_fatal(dev, err, "writing %s/sectors", | |
774 | dev->nodename); | |
775 | goto abort; | |
776 | } | |
777 | ||
778 | /* FIXME: use a typename instead */ | |
779 | err = xenbus_printf(xbt, dev->nodename, "info", "%u", | |
42c7841d KRW |
780 | be->blkif->vbd.type | |
781 | (be->blkif->vbd.readonly ? VDISK_READONLY : 0)); | |
4d05a28d KRW |
782 | if (err) { |
783 | xenbus_dev_fatal(dev, err, "writing %s/info", | |
784 | dev->nodename); | |
785 | goto abort; | |
786 | } | |
787 | err = xenbus_printf(xbt, dev->nodename, "sector-size", "%lu", | |
42c7841d KRW |
788 | (unsigned long) |
789 | bdev_logical_block_size(be->blkif->vbd.bdev)); | |
4d05a28d KRW |
790 | if (err) { |
791 | xenbus_dev_fatal(dev, err, "writing %s/sector-size", | |
792 | dev->nodename); | |
793 | goto abort; | |
794 | } | |
7c4d7d71 SB |
795 | err = xenbus_printf(xbt, dev->nodename, "physical-sector-size", "%u", |
796 | bdev_physical_block_size(be->blkif->vbd.bdev)); | |
797 | if (err) | |
798 | xenbus_dev_error(dev, err, "writing %s/physical-sector-size", | |
799 | dev->nodename); | |
4d05a28d KRW |
800 | |
801 | err = xenbus_transaction_end(xbt, 0); | |
802 | if (err == -EAGAIN) | |
803 | goto again; | |
804 | if (err) | |
805 | xenbus_dev_fatal(dev, err, "ending transaction"); | |
806 | ||
807 | err = xenbus_switch_state(dev, XenbusStateConnected); | |
808 | if (err) | |
08b8bfc1 | 809 | xenbus_dev_fatal(dev, err, "%s: switching to Connected state", |
4d05a28d KRW |
810 | dev->nodename); |
811 | ||
812 | return; | |
813 | abort: | |
814 | xenbus_transaction_end(xbt, 1); | |
815 | } | |
816 | ||
817 | ||
818 | static int connect_ring(struct backend_info *be) | |
819 | { | |
820 | struct xenbus_device *dev = be->dev; | |
821 | unsigned long ring_ref; | |
822 | unsigned int evtchn; | |
0a8704a5 | 823 | unsigned int pers_grants; |
4d05a28d | 824 | char protocol[64] = ""; |
69b91ede BL |
825 | struct pending_req *req, *n; |
826 | int err, i, j; | |
4d05a28d | 827 | |
77387b82 | 828 | pr_debug("%s %s\n", __func__, dev->otherend); |
4d05a28d | 829 | |
d6091b21 KRW |
830 | err = xenbus_gather(XBT_NIL, dev->otherend, "ring-ref", "%lu", |
831 | &ring_ref, "event-channel", "%u", &evtchn, NULL); | |
4d05a28d KRW |
832 | if (err) { |
833 | xenbus_dev_fatal(dev, err, | |
834 | "reading %s/ring-ref and event-channel", | |
835 | dev->otherend); | |
836 | return err; | |
837 | } | |
838 | ||
b042a3ca | 839 | be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT; |
4d05a28d KRW |
840 | err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", |
841 | "%63s", protocol, NULL); | |
842 | if (err) | |
b042a3ca | 843 | strcpy(protocol, "unspecified, assuming default"); |
4d05a28d KRW |
844 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) |
845 | be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; | |
846 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) | |
847 | be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_32; | |
848 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_64)) | |
849 | be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64; | |
850 | else { | |
851 | xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol); | |
852 | return -1; | |
853 | } | |
0a8704a5 | 854 | err = xenbus_gather(XBT_NIL, dev->otherend, |
cb5bd4d1 | 855 | "feature-persistent", "%u", |
0a8704a5 RPM |
856 | &pers_grants, NULL); |
857 | if (err) | |
858 | pers_grants = 0; | |
859 | ||
860 | be->blkif->vbd.feature_gnt_persistent = pers_grants; | |
861 | be->blkif->vbd.overflow_max_grants = 0; | |
862 | ||
77387b82 | 863 | pr_info("ring-ref %ld, event-channel %d, protocol %d (%s) %s\n", |
0a8704a5 RPM |
864 | ring_ref, evtchn, be->blkif->blk_protocol, protocol, |
865 | pers_grants ? "persistent grants" : ""); | |
4d05a28d | 866 | |
69b91ede BL |
867 | for (i = 0; i < XEN_BLKIF_REQS_PER_PAGE; i++) { |
868 | req = kzalloc(sizeof(*req), GFP_KERNEL); | |
869 | if (!req) | |
870 | goto fail; | |
871 | list_add_tail(&req->free_list, &be->blkif->pending_free); | |
872 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { | |
873 | req->segments[j] = kzalloc(sizeof(*req->segments[0]), GFP_KERNEL); | |
874 | if (!req->segments[j]) | |
875 | goto fail; | |
876 | } | |
877 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) { | |
878 | req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]), | |
879 | GFP_KERNEL); | |
880 | if (!req->indirect_pages[j]) | |
881 | goto fail; | |
882 | } | |
883 | } | |
884 | ||
4d05a28d | 885 | /* Map the shared frame, irq etc. */ |
8b6bf747 | 886 | err = xen_blkif_map(be->blkif, ring_ref, evtchn); |
4d05a28d KRW |
887 | if (err) { |
888 | xenbus_dev_fatal(dev, err, "mapping ring-ref %lu port %u", | |
889 | ring_ref, evtchn); | |
890 | return err; | |
891 | } | |
892 | ||
893 | return 0; | |
69b91ede BL |
894 | |
895 | fail: | |
896 | list_for_each_entry_safe(req, n, &be->blkif->pending_free, free_list) { | |
897 | list_del(&req->free_list); | |
898 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { | |
899 | if (!req->segments[j]) | |
900 | break; | |
901 | kfree(req->segments[j]); | |
902 | } | |
903 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) { | |
904 | if (!req->indirect_pages[j]) | |
905 | break; | |
906 | kfree(req->indirect_pages[j]); | |
907 | } | |
908 | kfree(req); | |
909 | } | |
910 | return -ENOMEM; | |
4d05a28d KRW |
911 | } |
912 | ||
8b6bf747 | 913 | static const struct xenbus_device_id xen_blkbk_ids[] = { |
4d05a28d KRW |
914 | { "vbd" }, |
915 | { "" } | |
916 | }; | |
917 | ||
95afae48 DV |
918 | static struct xenbus_driver xen_blkbk_driver = { |
919 | .ids = xen_blkbk_ids, | |
8b6bf747 KRW |
920 | .probe = xen_blkbk_probe, |
921 | .remove = xen_blkbk_remove, | |
4d05a28d | 922 | .otherend_changed = frontend_changed |
95afae48 | 923 | }; |
4d05a28d | 924 | |
8b6bf747 | 925 | int xen_blkif_xenbus_init(void) |
4d05a28d | 926 | { |
73db144b | 927 | return xenbus_register_backend(&xen_blkbk_driver); |
4d05a28d | 928 | } |