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 | ||
17 | #include <stdarg.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/kthread.h> | |
ee9ff853 KRW |
20 | #include <xen/events.h> |
21 | #include <xen/grant_table.h> | |
4d05a28d KRW |
22 | #include "common.h" |
23 | ||
d6091b21 | 24 | struct backend_info { |
01f37f2d | 25 | struct xenbus_device *dev; |
51854322 | 26 | struct xen_blkif *blkif; |
01f37f2d KRW |
27 | struct xenbus_watch backend_watch; |
28 | unsigned major; | |
29 | unsigned minor; | |
30 | char *mode; | |
4d05a28d KRW |
31 | }; |
32 | ||
8b6bf747 | 33 | static struct kmem_cache *xen_blkif_cachep; |
4d05a28d KRW |
34 | static void connect(struct backend_info *); |
35 | static int connect_ring(struct backend_info *); | |
36 | static void backend_changed(struct xenbus_watch *, const char **, | |
37 | unsigned int); | |
38 | ||
8b6bf747 | 39 | struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be) |
98e036a3 JF |
40 | { |
41 | return be->dev; | |
42 | } | |
43 | ||
30fd1502 | 44 | static int blkback_name(struct xen_blkif *blkif, char *buf) |
4d05a28d KRW |
45 | { |
46 | char *devpath, *devname; | |
47 | struct xenbus_device *dev = blkif->be->dev; | |
48 | ||
49 | devpath = xenbus_read(XBT_NIL, dev->nodename, "dev", NULL); | |
50 | if (IS_ERR(devpath)) | |
51 | return PTR_ERR(devpath); | |
52 | ||
d6091b21 KRW |
53 | devname = strstr(devpath, "/dev/"); |
54 | if (devname != NULL) | |
4d05a28d KRW |
55 | devname += strlen("/dev/"); |
56 | else | |
57 | devname = devpath; | |
58 | ||
59 | snprintf(buf, TASK_COMM_LEN, "blkback.%d.%s", blkif->domid, devname); | |
60 | kfree(devpath); | |
61 | ||
62 | return 0; | |
63 | } | |
64 | ||
30fd1502 | 65 | static void xen_update_blkif_status(struct xen_blkif *blkif) |
4d05a28d KRW |
66 | { |
67 | int err; | |
68 | char name[TASK_COMM_LEN]; | |
69 | ||
70 | /* Not ready to connect? */ | |
71 | if (!blkif->irq || !blkif->vbd.bdev) | |
72 | return; | |
73 | ||
74 | /* Already connected? */ | |
75 | if (blkif->be->dev->state == XenbusStateConnected) | |
76 | return; | |
77 | ||
78 | /* Attempt to connect: exit if we fail to. */ | |
79 | connect(blkif->be); | |
80 | if (blkif->be->dev->state != XenbusStateConnected) | |
81 | return; | |
82 | ||
83 | err = blkback_name(blkif, name); | |
84 | if (err) { | |
85 | xenbus_dev_error(blkif->be->dev, err, "get blkback dev name"); | |
86 | return; | |
87 | } | |
88 | ||
cbf46290 CL |
89 | err = filemap_write_and_wait(blkif->vbd.bdev->bd_inode->i_mapping); |
90 | if (err) { | |
91 | xenbus_dev_error(blkif->be->dev, err, "block flush"); | |
92 | return; | |
93 | } | |
94 | invalidate_inode_pages2(blkif->vbd.bdev->bd_inode->i_mapping); | |
95 | ||
f170168b | 96 | blkif->xenblkd = kthread_run(xen_blkif_schedule, blkif, "%s", name); |
4d05a28d KRW |
97 | if (IS_ERR(blkif->xenblkd)) { |
98 | err = PTR_ERR(blkif->xenblkd); | |
99 | blkif->xenblkd = NULL; | |
100 | xenbus_dev_error(blkif->be->dev, err, "start xenblkd"); | |
3f3aad5e | 101 | return; |
4d05a28d KRW |
102 | } |
103 | } | |
104 | ||
30fd1502 | 105 | static struct xen_blkif *xen_blkif_alloc(domid_t domid) |
ee9ff853 | 106 | { |
30fd1502 | 107 | struct xen_blkif *blkif; |
bb642e83 RPM |
108 | struct pending_req *req, *n; |
109 | int i, j; | |
ee9ff853 | 110 | |
402b27f9 | 111 | BUILD_BUG_ON(MAX_INDIRECT_PAGES > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST); |
ee9ff853 | 112 | |
654dbef2 | 113 | blkif = kmem_cache_zalloc(xen_blkif_cachep, GFP_KERNEL); |
ee9ff853 KRW |
114 | if (!blkif) |
115 | return ERR_PTR(-ENOMEM); | |
116 | ||
ee9ff853 KRW |
117 | blkif->domid = domid; |
118 | spin_lock_init(&blkif->blk_ring_lock); | |
119 | atomic_set(&blkif->refcnt, 1); | |
120 | init_waitqueue_head(&blkif->wq); | |
29bde093 KRW |
121 | init_completion(&blkif->drain_complete); |
122 | atomic_set(&blkif->drain, 0); | |
ee9ff853 KRW |
123 | blkif->st_print = jiffies; |
124 | init_waitqueue_head(&blkif->waiting_to_free); | |
0a8704a5 | 125 | blkif->persistent_gnts.rb_node = NULL; |
c6cc142d RPM |
126 | spin_lock_init(&blkif->free_pages_lock); |
127 | INIT_LIST_HEAD(&blkif->free_pages); | |
128 | blkif->free_pages_num = 0; | |
3f3aad5e | 129 | atomic_set(&blkif->persistent_gnt_in_use, 0); |
ee9ff853 | 130 | |
bf0720c4 | 131 | INIT_LIST_HEAD(&blkif->pending_free); |
bb642e83 RPM |
132 | |
133 | for (i = 0; i < XEN_BLKIF_REQS; i++) { | |
134 | req = kzalloc(sizeof(*req), GFP_KERNEL); | |
135 | if (!req) | |
136 | goto fail; | |
137 | list_add_tail(&req->free_list, | |
138 | &blkif->pending_free); | |
139 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { | |
140 | req->segments[j] = kzalloc(sizeof(*req->segments[0]), | |
141 | GFP_KERNEL); | |
142 | if (!req->segments[j]) | |
143 | goto fail; | |
144 | } | |
145 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) { | |
146 | req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]), | |
147 | GFP_KERNEL); | |
148 | if (!req->indirect_pages[j]) | |
149 | goto fail; | |
150 | } | |
151 | } | |
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; | |
bb642e83 RPM |
157 | |
158 | fail: | |
159 | list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) { | |
160 | list_del(&req->free_list); | |
161 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { | |
162 | if (!req->segments[j]) | |
163 | break; | |
164 | kfree(req->segments[j]); | |
165 | } | |
166 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) { | |
167 | if (!req->indirect_pages[j]) | |
168 | break; | |
169 | kfree(req->indirect_pages[j]); | |
170 | } | |
171 | kfree(req); | |
172 | } | |
173 | ||
174 | kmem_cache_free(xen_blkif_cachep, blkif); | |
175 | ||
176 | return ERR_PTR(-ENOMEM); | |
ee9ff853 KRW |
177 | } |
178 | ||
30fd1502 | 179 | static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page, |
8b6bf747 | 180 | unsigned int evtchn) |
ee9ff853 KRW |
181 | { |
182 | int err; | |
183 | ||
184 | /* Already connected through? */ | |
185 | if (blkif->irq) | |
186 | return 0; | |
187 | ||
2d073846 DV |
188 | err = xenbus_map_ring_valloc(blkif->be->dev, shared_page, &blkif->blk_ring); |
189 | if (err < 0) | |
ee9ff853 | 190 | return err; |
ee9ff853 KRW |
191 | |
192 | switch (blkif->blk_protocol) { | |
193 | case BLKIF_PROTOCOL_NATIVE: | |
194 | { | |
195 | struct blkif_sring *sring; | |
2d073846 | 196 | sring = (struct blkif_sring *)blkif->blk_ring; |
ee9ff853 KRW |
197 | BACK_RING_INIT(&blkif->blk_rings.native, sring, PAGE_SIZE); |
198 | break; | |
199 | } | |
200 | case BLKIF_PROTOCOL_X86_32: | |
201 | { | |
202 | struct blkif_x86_32_sring *sring_x86_32; | |
2d073846 | 203 | sring_x86_32 = (struct blkif_x86_32_sring *)blkif->blk_ring; |
ee9ff853 KRW |
204 | BACK_RING_INIT(&blkif->blk_rings.x86_32, sring_x86_32, PAGE_SIZE); |
205 | break; | |
206 | } | |
207 | case BLKIF_PROTOCOL_X86_64: | |
208 | { | |
209 | struct blkif_x86_64_sring *sring_x86_64; | |
2d073846 | 210 | sring_x86_64 = (struct blkif_x86_64_sring *)blkif->blk_ring; |
ee9ff853 KRW |
211 | BACK_RING_INIT(&blkif->blk_rings.x86_64, sring_x86_64, PAGE_SIZE); |
212 | break; | |
213 | } | |
214 | default: | |
215 | BUG(); | |
216 | } | |
217 | ||
8b6bf747 KRW |
218 | err = bind_interdomain_evtchn_to_irqhandler(blkif->domid, evtchn, |
219 | xen_blkif_be_int, 0, | |
220 | "blkif-backend", blkif); | |
ee9ff853 | 221 | if (err < 0) { |
2d073846 | 222 | xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring); |
ee9ff853 KRW |
223 | blkif->blk_rings.common.sring = NULL; |
224 | return err; | |
225 | } | |
226 | blkif->irq = err; | |
227 | ||
228 | return 0; | |
229 | } | |
230 | ||
30fd1502 | 231 | static void xen_blkif_disconnect(struct xen_blkif *blkif) |
ee9ff853 KRW |
232 | { |
233 | if (blkif->xenblkd) { | |
234 | kthread_stop(blkif->xenblkd); | |
8e3f8755 | 235 | wake_up(&blkif->shutdown_wq); |
ee9ff853 KRW |
236 | blkif->xenblkd = NULL; |
237 | } | |
238 | ||
239 | atomic_dec(&blkif->refcnt); | |
240 | wait_event(blkif->waiting_to_free, atomic_read(&blkif->refcnt) == 0); | |
241 | atomic_inc(&blkif->refcnt); | |
242 | ||
243 | if (blkif->irq) { | |
244 | unbind_from_irqhandler(blkif->irq, blkif); | |
245 | blkif->irq = 0; | |
246 | } | |
247 | ||
248 | if (blkif->blk_rings.common.sring) { | |
2d073846 | 249 | xenbus_unmap_ring_vfree(blkif->be->dev, blkif->blk_ring); |
ee9ff853 KRW |
250 | blkif->blk_rings.common.sring = NULL; |
251 | } | |
252 | } | |
253 | ||
2911758f | 254 | static void xen_blkif_free(struct xen_blkif *blkif) |
ee9ff853 | 255 | { |
bb642e83 RPM |
256 | struct pending_req *req, *n; |
257 | int i = 0, j; | |
bf0720c4 | 258 | |
ee9ff853 KRW |
259 | if (!atomic_dec_and_test(&blkif->refcnt)) |
260 | BUG(); | |
bf0720c4 RPM |
261 | |
262 | /* Check that there is no request in use */ | |
bb642e83 RPM |
263 | list_for_each_entry_safe(req, n, &blkif->pending_free, free_list) { |
264 | list_del(&req->free_list); | |
265 | ||
266 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) | |
267 | kfree(req->segments[j]); | |
268 | ||
269 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) | |
270 | kfree(req->indirect_pages[j]); | |
271 | ||
272 | kfree(req); | |
bf0720c4 | 273 | i++; |
bb642e83 RPM |
274 | } |
275 | ||
276 | WARN_ON(i != XEN_BLKIF_REQS); | |
bf0720c4 | 277 | |
8b6bf747 | 278 | kmem_cache_free(xen_blkif_cachep, blkif); |
ee9ff853 KRW |
279 | } |
280 | ||
8b6bf747 | 281 | int __init xen_blkif_interface_init(void) |
ee9ff853 | 282 | { |
8b6bf747 | 283 | xen_blkif_cachep = kmem_cache_create("blkif_cache", |
30fd1502 | 284 | sizeof(struct xen_blkif), |
8b6bf747 KRW |
285 | 0, 0, NULL); |
286 | if (!xen_blkif_cachep) | |
ee9ff853 KRW |
287 | return -ENOMEM; |
288 | ||
289 | return 0; | |
290 | } | |
4d05a28d | 291 | |
a1397fa3 | 292 | /* |
4d05a28d KRW |
293 | * sysfs interface for VBD I/O requests |
294 | */ | |
295 | ||
296 | #define VBD_SHOW(name, format, args...) \ | |
297 | static ssize_t show_##name(struct device *_dev, \ | |
298 | struct device_attribute *attr, \ | |
299 | char *buf) \ | |
300 | { \ | |
301 | struct xenbus_device *dev = to_xenbus_device(_dev); \ | |
5cf6e4f6 | 302 | struct backend_info *be = dev_get_drvdata(&dev->dev); \ |
4d05a28d KRW |
303 | \ |
304 | return sprintf(buf, format, ##args); \ | |
305 | } \ | |
306 | static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL) | |
307 | ||
986cacbd ZK |
308 | VBD_SHOW(oo_req, "%llu\n", be->blkif->st_oo_req); |
309 | VBD_SHOW(rd_req, "%llu\n", be->blkif->st_rd_req); | |
310 | VBD_SHOW(wr_req, "%llu\n", be->blkif->st_wr_req); | |
311 | VBD_SHOW(f_req, "%llu\n", be->blkif->st_f_req); | |
312 | VBD_SHOW(ds_req, "%llu\n", be->blkif->st_ds_req); | |
313 | VBD_SHOW(rd_sect, "%llu\n", be->blkif->st_rd_sect); | |
314 | VBD_SHOW(wr_sect, "%llu\n", be->blkif->st_wr_sect); | |
4d05a28d | 315 | |
3d814731 | 316 | static struct attribute *xen_vbdstat_attrs[] = { |
4d05a28d KRW |
317 | &dev_attr_oo_req.attr, |
318 | &dev_attr_rd_req.attr, | |
319 | &dev_attr_wr_req.attr, | |
24f567f9 | 320 | &dev_attr_f_req.attr, |
b3cb0d6a | 321 | &dev_attr_ds_req.attr, |
4d05a28d KRW |
322 | &dev_attr_rd_sect.attr, |
323 | &dev_attr_wr_sect.attr, | |
324 | NULL | |
325 | }; | |
326 | ||
3d814731 | 327 | static struct attribute_group xen_vbdstat_group = { |
4d05a28d | 328 | .name = "statistics", |
3d814731 | 329 | .attrs = xen_vbdstat_attrs, |
4d05a28d KRW |
330 | }; |
331 | ||
332 | VBD_SHOW(physical_device, "%x:%x\n", be->major, be->minor); | |
333 | VBD_SHOW(mode, "%s\n", be->mode); | |
334 | ||
2911758f | 335 | static int xenvbd_sysfs_addif(struct xenbus_device *dev) |
4d05a28d KRW |
336 | { |
337 | int error; | |
338 | ||
339 | error = device_create_file(&dev->dev, &dev_attr_physical_device); | |
d6091b21 | 340 | if (error) |
4d05a28d KRW |
341 | goto fail1; |
342 | ||
343 | error = device_create_file(&dev->dev, &dev_attr_mode); | |
344 | if (error) | |
345 | goto fail2; | |
346 | ||
3d814731 | 347 | error = sysfs_create_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
348 | if (error) |
349 | goto fail3; | |
350 | ||
351 | return 0; | |
352 | ||
3d814731 | 353 | fail3: sysfs_remove_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
354 | fail2: device_remove_file(&dev->dev, &dev_attr_mode); |
355 | fail1: device_remove_file(&dev->dev, &dev_attr_physical_device); | |
356 | return error; | |
357 | } | |
358 | ||
2911758f | 359 | static void xenvbd_sysfs_delif(struct xenbus_device *dev) |
4d05a28d | 360 | { |
3d814731 | 361 | sysfs_remove_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
362 | device_remove_file(&dev->dev, &dev_attr_mode); |
363 | device_remove_file(&dev->dev, &dev_attr_physical_device); | |
364 | } | |
365 | ||
42c7841d | 366 | |
3d814731 | 367 | static void xen_vbd_free(struct xen_vbd *vbd) |
42c7841d KRW |
368 | { |
369 | if (vbd->bdev) | |
370 | blkdev_put(vbd->bdev, vbd->readonly ? FMODE_READ : FMODE_WRITE); | |
371 | vbd->bdev = NULL; | |
372 | } | |
373 | ||
3d814731 KRW |
374 | static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle, |
375 | unsigned major, unsigned minor, int readonly, | |
376 | int cdrom) | |
42c7841d | 377 | { |
3d814731 | 378 | struct xen_vbd *vbd; |
42c7841d | 379 | struct block_device *bdev; |
24f567f9 | 380 | struct request_queue *q; |
42c7841d KRW |
381 | |
382 | vbd = &blkif->vbd; | |
383 | vbd->handle = handle; | |
384 | vbd->readonly = readonly; | |
385 | vbd->type = 0; | |
386 | ||
387 | vbd->pdevice = MKDEV(major, minor); | |
388 | ||
389 | bdev = blkdev_get_by_dev(vbd->pdevice, vbd->readonly ? | |
390 | FMODE_READ : FMODE_WRITE, NULL); | |
391 | ||
392 | if (IS_ERR(bdev)) { | |
3d814731 | 393 | DPRINTK("xen_vbd_create: device %08x could not be opened.\n", |
42c7841d KRW |
394 | vbd->pdevice); |
395 | return -ENOENT; | |
396 | } | |
397 | ||
398 | vbd->bdev = bdev; | |
42c7841d | 399 | if (vbd->bdev->bd_disk == NULL) { |
3d814731 | 400 | DPRINTK("xen_vbd_create: device %08x doesn't exist.\n", |
42c7841d | 401 | vbd->pdevice); |
3d814731 | 402 | xen_vbd_free(vbd); |
42c7841d KRW |
403 | return -ENOENT; |
404 | } | |
6464920a | 405 | vbd->size = vbd_sz(vbd); |
42c7841d KRW |
406 | |
407 | if (vbd->bdev->bd_disk->flags & GENHD_FL_CD || cdrom) | |
408 | vbd->type |= VDISK_CDROM; | |
409 | if (vbd->bdev->bd_disk->flags & GENHD_FL_REMOVABLE) | |
410 | vbd->type |= VDISK_REMOVABLE; | |
411 | ||
24f567f9 KRW |
412 | q = bdev_get_queue(bdev); |
413 | if (q && q->flush_flags) | |
414 | vbd->flush_support = true; | |
415 | ||
5ea42986 KRW |
416 | if (q && blk_queue_secdiscard(q)) |
417 | vbd->discard_secure = true; | |
418 | ||
42c7841d KRW |
419 | DPRINTK("Successful creation of handle=%04x (dom=%u)\n", |
420 | handle, blkif->domid); | |
421 | return 0; | |
422 | } | |
8b6bf747 | 423 | static int xen_blkbk_remove(struct xenbus_device *dev) |
4d05a28d | 424 | { |
5cf6e4f6 | 425 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
4d05a28d KRW |
426 | |
427 | DPRINTK(""); | |
428 | ||
429 | if (be->major || be->minor) | |
430 | xenvbd_sysfs_delif(dev); | |
431 | ||
432 | if (be->backend_watch.node) { | |
433 | unregister_xenbus_watch(&be->backend_watch); | |
434 | kfree(be->backend_watch.node); | |
435 | be->backend_watch.node = NULL; | |
436 | } | |
437 | ||
438 | if (be->blkif) { | |
8b6bf747 | 439 | xen_blkif_disconnect(be->blkif); |
3d814731 | 440 | xen_vbd_free(&be->blkif->vbd); |
8b6bf747 | 441 | xen_blkif_free(be->blkif); |
4d05a28d KRW |
442 | be->blkif = NULL; |
443 | } | |
444 | ||
9d092603 | 445 | kfree(be->mode); |
4d05a28d | 446 | kfree(be); |
5cf6e4f6 | 447 | dev_set_drvdata(&dev->dev, NULL); |
4d05a28d KRW |
448 | return 0; |
449 | } | |
450 | ||
24f567f9 KRW |
451 | int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt, |
452 | struct backend_info *be, int state) | |
4d05a28d KRW |
453 | { |
454 | struct xenbus_device *dev = be->dev; | |
455 | int err; | |
456 | ||
24f567f9 | 457 | err = xenbus_printf(xbt, dev->nodename, "feature-flush-cache", |
4d05a28d KRW |
458 | "%d", state); |
459 | if (err) | |
3389bb8b | 460 | dev_warn(&dev->dev, "writing feature-flush-cache (%d)", err); |
4d05a28d KRW |
461 | |
462 | return err; | |
463 | } | |
464 | ||
3389bb8b | 465 | static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be) |
b3cb0d6a LD |
466 | { |
467 | struct xenbus_device *dev = be->dev; | |
468 | struct xen_blkif *blkif = be->blkif; | |
b3cb0d6a LD |
469 | int err; |
470 | int state = 0; | |
4dae7670 KRW |
471 | struct block_device *bdev = be->blkif->vbd.bdev; |
472 | struct request_queue *q = bdev_get_queue(bdev); | |
473 | ||
474 | if (blk_queue_discard(q)) { | |
475 | err = xenbus_printf(xbt, dev->nodename, | |
476 | "discard-granularity", "%u", | |
477 | q->limits.discard_granularity); | |
478 | if (err) { | |
3389bb8b KRW |
479 | dev_warn(&dev->dev, "writing discard-granularity (%d)", err); |
480 | return; | |
4dae7670 KRW |
481 | } |
482 | err = xenbus_printf(xbt, dev->nodename, | |
483 | "discard-alignment", "%u", | |
484 | q->limits.discard_alignment); | |
485 | if (err) { | |
3389bb8b KRW |
486 | dev_warn(&dev->dev, "writing discard-alignment (%d)", err); |
487 | return; | |
b3cb0d6a | 488 | } |
4dae7670 KRW |
489 | state = 1; |
490 | /* Optional. */ | |
491 | err = xenbus_printf(xbt, dev->nodename, | |
492 | "discard-secure", "%d", | |
493 | blkif->vbd.discard_secure); | |
494 | if (err) { | |
a71e23d9 | 495 | dev_warn(&dev->dev, "writing discard-secure (%d)", err); |
3389bb8b | 496 | return; |
b3cb0d6a | 497 | } |
b3cb0d6a | 498 | } |
b3cb0d6a LD |
499 | err = xenbus_printf(xbt, dev->nodename, "feature-discard", |
500 | "%d", state); | |
501 | if (err) | |
3389bb8b | 502 | dev_warn(&dev->dev, "writing feature-discard (%d)", err); |
b3cb0d6a | 503 | } |
29bde093 KRW |
504 | int xen_blkbk_barrier(struct xenbus_transaction xbt, |
505 | struct backend_info *be, int state) | |
506 | { | |
507 | struct xenbus_device *dev = be->dev; | |
508 | int err; | |
509 | ||
510 | err = xenbus_printf(xbt, dev->nodename, "feature-barrier", | |
511 | "%d", state); | |
512 | if (err) | |
3389bb8b | 513 | dev_warn(&dev->dev, "writing feature-barrier (%d)", err); |
29bde093 KRW |
514 | |
515 | return err; | |
516 | } | |
b3cb0d6a | 517 | |
01f37f2d | 518 | /* |
4d05a28d KRW |
519 | * Entry point to this code when a new device is created. Allocate the basic |
520 | * structures, and watch the store waiting for the hotplug scripts to tell us | |
521 | * the device's physical major and minor numbers. Switch to InitWait. | |
522 | */ | |
8b6bf747 KRW |
523 | static int xen_blkbk_probe(struct xenbus_device *dev, |
524 | const struct xenbus_device_id *id) | |
4d05a28d KRW |
525 | { |
526 | int err; | |
527 | struct backend_info *be = kzalloc(sizeof(struct backend_info), | |
528 | GFP_KERNEL); | |
529 | if (!be) { | |
530 | xenbus_dev_fatal(dev, -ENOMEM, | |
531 | "allocating backend structure"); | |
532 | return -ENOMEM; | |
533 | } | |
534 | be->dev = dev; | |
5cf6e4f6 | 535 | dev_set_drvdata(&dev->dev, be); |
4d05a28d | 536 | |
8b6bf747 | 537 | be->blkif = xen_blkif_alloc(dev->otherend_id); |
4d05a28d KRW |
538 | if (IS_ERR(be->blkif)) { |
539 | err = PTR_ERR(be->blkif); | |
540 | be->blkif = NULL; | |
541 | xenbus_dev_fatal(dev, err, "creating block interface"); | |
542 | goto fail; | |
543 | } | |
544 | ||
545 | /* setup back pointer */ | |
546 | be->blkif->be = be; | |
547 | ||
88122933 JF |
548 | err = xenbus_watch_pathfmt(dev, &be->backend_watch, backend_changed, |
549 | "%s/%s", dev->nodename, "physical-device"); | |
4d05a28d KRW |
550 | if (err) |
551 | goto fail; | |
552 | ||
553 | err = xenbus_switch_state(dev, XenbusStateInitWait); | |
554 | if (err) | |
555 | goto fail; | |
556 | ||
557 | return 0; | |
558 | ||
559 | fail: | |
560 | DPRINTK("failed"); | |
8b6bf747 | 561 | xen_blkbk_remove(dev); |
4d05a28d KRW |
562 | return err; |
563 | } | |
564 | ||
565 | ||
01f37f2d | 566 | /* |
4d05a28d KRW |
567 | * Callback received when the hotplug scripts have placed the physical-device |
568 | * node. Read it and the mode node, and create a vbd. If the frontend is | |
569 | * ready, connect. | |
570 | */ | |
571 | static void backend_changed(struct xenbus_watch *watch, | |
572 | const char **vec, unsigned int len) | |
573 | { | |
574 | int err; | |
575 | unsigned major; | |
576 | unsigned minor; | |
577 | struct backend_info *be | |
578 | = container_of(watch, struct backend_info, backend_watch); | |
579 | struct xenbus_device *dev = be->dev; | |
580 | int cdrom = 0; | |
9d092603 | 581 | unsigned long handle; |
4d05a28d KRW |
582 | char *device_type; |
583 | ||
584 | DPRINTK(""); | |
585 | ||
586 | err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x", | |
587 | &major, &minor); | |
588 | if (XENBUS_EXIST_ERR(err)) { | |
01f37f2d KRW |
589 | /* |
590 | * Since this watch will fire once immediately after it is | |
591 | * registered, we expect this. Ignore it, and wait for the | |
592 | * hotplug scripts. | |
593 | */ | |
4d05a28d KRW |
594 | return; |
595 | } | |
596 | if (err != 2) { | |
597 | xenbus_dev_fatal(dev, err, "reading physical-device"); | |
598 | return; | |
599 | } | |
600 | ||
9d092603 JB |
601 | if (be->major | be->minor) { |
602 | if (be->major != major || be->minor != minor) | |
603 | pr_warn(DRV_PFX "changing physical device (from %x:%x to %x:%x) not supported.\n", | |
604 | be->major, be->minor, major, minor); | |
4d05a28d KRW |
605 | return; |
606 | } | |
607 | ||
608 | be->mode = xenbus_read(XBT_NIL, dev->nodename, "mode", NULL); | |
609 | if (IS_ERR(be->mode)) { | |
610 | err = PTR_ERR(be->mode); | |
611 | be->mode = NULL; | |
612 | xenbus_dev_fatal(dev, err, "reading mode"); | |
613 | return; | |
614 | } | |
615 | ||
616 | device_type = xenbus_read(XBT_NIL, dev->otherend, "device-type", NULL); | |
617 | if (!IS_ERR(device_type)) { | |
618 | cdrom = strcmp(device_type, "cdrom") == 0; | |
619 | kfree(device_type); | |
620 | } | |
621 | ||
9d092603 JB |
622 | /* Front end dir is a number, which is used as the handle. */ |
623 | err = strict_strtoul(strrchr(dev->otherend, '/') + 1, 0, &handle); | |
624 | if (err) | |
625 | return; | |
4d05a28d | 626 | |
9d092603 JB |
627 | be->major = major; |
628 | be->minor = minor; | |
4d05a28d | 629 | |
9d092603 JB |
630 | err = xen_vbd_create(be->blkif, handle, major, minor, |
631 | !strchr(be->mode, 'w'), cdrom); | |
4d05a28d | 632 | |
9d092603 JB |
633 | if (err) |
634 | xenbus_dev_fatal(dev, err, "creating vbd structure"); | |
635 | else { | |
4d05a28d KRW |
636 | err = xenvbd_sysfs_addif(dev); |
637 | if (err) { | |
3d814731 | 638 | xen_vbd_free(&be->blkif->vbd); |
4d05a28d | 639 | xenbus_dev_fatal(dev, err, "creating sysfs entries"); |
4d05a28d | 640 | } |
9d092603 | 641 | } |
4d05a28d | 642 | |
9d092603 JB |
643 | if (err) { |
644 | kfree(be->mode); | |
645 | be->mode = NULL; | |
646 | be->major = 0; | |
647 | be->minor = 0; | |
648 | } else { | |
4d05a28d | 649 | /* We're potentially connected now */ |
8b6bf747 | 650 | xen_update_blkif_status(be->blkif); |
4d05a28d KRW |
651 | } |
652 | } | |
653 | ||
654 | ||
01f37f2d | 655 | /* |
4d05a28d KRW |
656 | * Callback received when the frontend's state changes. |
657 | */ | |
658 | static void frontend_changed(struct xenbus_device *dev, | |
659 | enum xenbus_state frontend_state) | |
660 | { | |
5cf6e4f6 | 661 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
4d05a28d KRW |
662 | int err; |
663 | ||
664 | DPRINTK("%s", xenbus_strstate(frontend_state)); | |
665 | ||
666 | switch (frontend_state) { | |
667 | case XenbusStateInitialising: | |
668 | if (dev->state == XenbusStateClosed) { | |
22b20f2d | 669 | pr_info(DRV_PFX "%s: prepare for reconnect\n", |
ebe81906 | 670 | dev->nodename); |
4d05a28d KRW |
671 | xenbus_switch_state(dev, XenbusStateInitWait); |
672 | } | |
673 | break; | |
674 | ||
675 | case XenbusStateInitialised: | |
676 | case XenbusStateConnected: | |
01f37f2d KRW |
677 | /* |
678 | * Ensure we connect even when two watches fire in | |
42b2aa86 | 679 | * close succession and we miss the intermediate value |
01f37f2d KRW |
680 | * of frontend_state. |
681 | */ | |
4d05a28d KRW |
682 | if (dev->state == XenbusStateConnected) |
683 | break; | |
684 | ||
01f37f2d KRW |
685 | /* |
686 | * Enforce precondition before potential leak point. | |
1bc05b0a | 687 | * xen_blkif_disconnect() is idempotent. |
313d7b00 | 688 | */ |
8b6bf747 | 689 | xen_blkif_disconnect(be->blkif); |
313d7b00 | 690 | |
4d05a28d KRW |
691 | err = connect_ring(be); |
692 | if (err) | |
693 | break; | |
8b6bf747 | 694 | xen_update_blkif_status(be->blkif); |
4d05a28d KRW |
695 | break; |
696 | ||
697 | case XenbusStateClosing: | |
4d05a28d KRW |
698 | xenbus_switch_state(dev, XenbusStateClosing); |
699 | break; | |
700 | ||
701 | case XenbusStateClosed: | |
6f5986bc | 702 | xen_blkif_disconnect(be->blkif); |
4d05a28d KRW |
703 | xenbus_switch_state(dev, XenbusStateClosed); |
704 | if (xenbus_dev_is_online(dev)) | |
705 | break; | |
706 | /* fall through if not online */ | |
707 | case XenbusStateUnknown: | |
1bc05b0a | 708 | /* implies xen_blkif_disconnect() via xen_blkbk_remove() */ |
4d05a28d KRW |
709 | device_unregister(&dev->dev); |
710 | break; | |
711 | ||
712 | default: | |
713 | xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", | |
714 | frontend_state); | |
715 | break; | |
716 | } | |
717 | } | |
718 | ||
719 | ||
720 | /* ** Connection ** */ | |
721 | ||
722 | ||
01f37f2d | 723 | /* |
4d05a28d KRW |
724 | * Write the physical details regarding the block device to the store, and |
725 | * switch to Connected state. | |
726 | */ | |
727 | static void connect(struct backend_info *be) | |
728 | { | |
729 | struct xenbus_transaction xbt; | |
730 | int err; | |
731 | struct xenbus_device *dev = be->dev; | |
732 | ||
733 | DPRINTK("%s", dev->otherend); | |
734 | ||
735 | /* Supply the information about the device the frontend needs */ | |
736 | again: | |
737 | err = xenbus_transaction_start(&xbt); | |
738 | if (err) { | |
739 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
740 | return; | |
741 | } | |
742 | ||
3389bb8b KRW |
743 | /* If we can't advertise it is OK. */ |
744 | xen_blkbk_flush_diskcache(xbt, be, be->blkif->vbd.flush_support); | |
4d05a28d | 745 | |
3389bb8b | 746 | xen_blkbk_discard(xbt, be); |
b3cb0d6a | 747 | |
3389bb8b | 748 | xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support); |
29bde093 | 749 | |
0a8704a5 RPM |
750 | err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u", 1); |
751 | if (err) { | |
752 | xenbus_dev_fatal(dev, err, "writing %s/feature-persistent", | |
753 | dev->nodename); | |
754 | goto abort; | |
755 | } | |
402b27f9 RPM |
756 | err = xenbus_printf(xbt, dev->nodename, "feature-max-indirect-segments", "%u", |
757 | MAX_INDIRECT_SEGMENTS); | |
758 | if (err) | |
759 | dev_warn(&dev->dev, "writing %s/feature-max-indirect-segments (%d)", | |
760 | dev->nodename, err); | |
0a8704a5 | 761 | |
4d05a28d | 762 | err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu", |
42c7841d | 763 | (unsigned long long)vbd_sz(&be->blkif->vbd)); |
4d05a28d KRW |
764 | if (err) { |
765 | xenbus_dev_fatal(dev, err, "writing %s/sectors", | |
766 | dev->nodename); | |
767 | goto abort; | |
768 | } | |
769 | ||
770 | /* FIXME: use a typename instead */ | |
771 | err = xenbus_printf(xbt, dev->nodename, "info", "%u", | |
42c7841d KRW |
772 | be->blkif->vbd.type | |
773 | (be->blkif->vbd.readonly ? VDISK_READONLY : 0)); | |
4d05a28d KRW |
774 | if (err) { |
775 | xenbus_dev_fatal(dev, err, "writing %s/info", | |
776 | dev->nodename); | |
777 | goto abort; | |
778 | } | |
779 | err = xenbus_printf(xbt, dev->nodename, "sector-size", "%lu", | |
42c7841d KRW |
780 | (unsigned long) |
781 | bdev_logical_block_size(be->blkif->vbd.bdev)); | |
4d05a28d KRW |
782 | if (err) { |
783 | xenbus_dev_fatal(dev, err, "writing %s/sector-size", | |
784 | dev->nodename); | |
785 | goto abort; | |
786 | } | |
7c4d7d71 SB |
787 | err = xenbus_printf(xbt, dev->nodename, "physical-sector-size", "%u", |
788 | bdev_physical_block_size(be->blkif->vbd.bdev)); | |
789 | if (err) | |
790 | xenbus_dev_error(dev, err, "writing %s/physical-sector-size", | |
791 | dev->nodename); | |
4d05a28d KRW |
792 | |
793 | err = xenbus_transaction_end(xbt, 0); | |
794 | if (err == -EAGAIN) | |
795 | goto again; | |
796 | if (err) | |
797 | xenbus_dev_fatal(dev, err, "ending transaction"); | |
798 | ||
799 | err = xenbus_switch_state(dev, XenbusStateConnected); | |
800 | if (err) | |
08b8bfc1 | 801 | xenbus_dev_fatal(dev, err, "%s: switching to Connected state", |
4d05a28d KRW |
802 | dev->nodename); |
803 | ||
804 | return; | |
805 | abort: | |
806 | xenbus_transaction_end(xbt, 1); | |
807 | } | |
808 | ||
809 | ||
810 | static int connect_ring(struct backend_info *be) | |
811 | { | |
812 | struct xenbus_device *dev = be->dev; | |
813 | unsigned long ring_ref; | |
814 | unsigned int evtchn; | |
0a8704a5 | 815 | unsigned int pers_grants; |
4d05a28d KRW |
816 | char protocol[64] = ""; |
817 | int err; | |
818 | ||
819 | DPRINTK("%s", dev->otherend); | |
820 | ||
d6091b21 KRW |
821 | err = xenbus_gather(XBT_NIL, dev->otherend, "ring-ref", "%lu", |
822 | &ring_ref, "event-channel", "%u", &evtchn, NULL); | |
4d05a28d KRW |
823 | if (err) { |
824 | xenbus_dev_fatal(dev, err, | |
825 | "reading %s/ring-ref and event-channel", | |
826 | dev->otherend); | |
827 | return err; | |
828 | } | |
829 | ||
830 | be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; | |
831 | err = xenbus_gather(XBT_NIL, dev->otherend, "protocol", | |
832 | "%63s", protocol, NULL); | |
833 | if (err) | |
834 | strcpy(protocol, "unspecified, assuming native"); | |
835 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) | |
836 | be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; | |
837 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) | |
838 | be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_32; | |
839 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_64)) | |
840 | be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64; | |
841 | else { | |
842 | xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol); | |
843 | return -1; | |
844 | } | |
0a8704a5 | 845 | err = xenbus_gather(XBT_NIL, dev->otherend, |
cb5bd4d1 | 846 | "feature-persistent", "%u", |
0a8704a5 RPM |
847 | &pers_grants, NULL); |
848 | if (err) | |
849 | pers_grants = 0; | |
850 | ||
851 | be->blkif->vbd.feature_gnt_persistent = pers_grants; | |
852 | be->blkif->vbd.overflow_max_grants = 0; | |
853 | ||
854 | pr_info(DRV_PFX "ring-ref %ld, event-channel %d, protocol %d (%s) %s\n", | |
855 | ring_ref, evtchn, be->blkif->blk_protocol, protocol, | |
856 | pers_grants ? "persistent grants" : ""); | |
4d05a28d KRW |
857 | |
858 | /* Map the shared frame, irq etc. */ | |
8b6bf747 | 859 | err = xen_blkif_map(be->blkif, ring_ref, evtchn); |
4d05a28d KRW |
860 | if (err) { |
861 | xenbus_dev_fatal(dev, err, "mapping ring-ref %lu port %u", | |
862 | ring_ref, evtchn); | |
863 | return err; | |
864 | } | |
865 | ||
866 | return 0; | |
867 | } | |
868 | ||
869 | ||
870 | /* ** Driver Registration ** */ | |
871 | ||
872 | ||
8b6bf747 | 873 | static const struct xenbus_device_id xen_blkbk_ids[] = { |
4d05a28d KRW |
874 | { "vbd" }, |
875 | { "" } | |
876 | }; | |
877 | ||
878 | ||
73db144b | 879 | static DEFINE_XENBUS_DRIVER(xen_blkbk, , |
8b6bf747 KRW |
880 | .probe = xen_blkbk_probe, |
881 | .remove = xen_blkbk_remove, | |
4d05a28d | 882 | .otherend_changed = frontend_changed |
73db144b | 883 | ); |
4d05a28d KRW |
884 | |
885 | ||
8b6bf747 | 886 | int xen_blkif_xenbus_init(void) |
4d05a28d | 887 | { |
73db144b | 888 | return xenbus_register_backend(&xen_blkbk_driver); |
4d05a28d | 889 | } |