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Commit | Line | Data |
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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 | ||
fa3184b8 | 26 | /* On the XenBus the max length of 'ring-ref%u'. */ |
86839c56 | 27 | #define RINGREF_NAME_LEN (20) |
1375590d | 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 *); | |
5584ea25 JG |
41 | static void backend_changed(struct xenbus_watch *, const char *, |
42 | const char *); | |
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 | ||
fa3184b8 | 78 | snprintf(buf, TASK_COMM_LEN, "%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; | |
fa3184b8 | 87 | char name[TASK_COMM_LEN]; |
2fb1ef4f KRW |
88 | struct xen_blkif_ring *ring; |
89 | int i; | |
4d05a28d KRW |
90 | |
91 | /* Not ready to connect? */ | |
2fb1ef4f | 92 | if (!blkif->rings || !blkif->rings[0].irq || !blkif->vbd.bdev) |
4d05a28d KRW |
93 | return; |
94 | ||
95 | /* Already connected? */ | |
96 | if (blkif->be->dev->state == XenbusStateConnected) | |
97 | return; | |
98 | ||
99 | /* Attempt to connect: exit if we fail to. */ | |
100 | connect(blkif->be); | |
101 | if (blkif->be->dev->state != XenbusStateConnected) | |
102 | return; | |
103 | ||
104 | err = blkback_name(blkif, name); | |
105 | if (err) { | |
106 | xenbus_dev_error(blkif->be->dev, err, "get blkback dev name"); | |
107 | return; | |
108 | } | |
109 | ||
cbf46290 CL |
110 | err = filemap_write_and_wait(blkif->vbd.bdev->bd_inode->i_mapping); |
111 | if (err) { | |
112 | xenbus_dev_error(blkif->be->dev, err, "block flush"); | |
113 | return; | |
114 | } | |
115 | invalidate_inode_pages2(blkif->vbd.bdev->bd_inode->i_mapping); | |
116 | ||
2fb1ef4f KRW |
117 | for (i = 0; i < blkif->nr_rings; i++) { |
118 | ring = &blkif->rings[i]; | |
119 | ring->xenblkd = kthread_run(xen_blkif_schedule, ring, "%s-%d", name, i); | |
120 | if (IS_ERR(ring->xenblkd)) { | |
121 | err = PTR_ERR(ring->xenblkd); | |
122 | ring->xenblkd = NULL; | |
123 | xenbus_dev_fatal(blkif->be->dev, err, | |
124 | "start %s-%d xenblkd", name, i); | |
125 | goto out; | |
126 | } | |
127 | } | |
128 | return; | |
129 | ||
130 | out: | |
131 | while (--i >= 0) { | |
132 | ring = &blkif->rings[i]; | |
133 | kthread_stop(ring->xenblkd); | |
4d05a28d | 134 | } |
2fb1ef4f KRW |
135 | return; |
136 | } | |
137 | ||
138 | static int xen_blkif_alloc_rings(struct xen_blkif *blkif) | |
139 | { | |
140 | unsigned int r; | |
141 | ||
6396bb22 KC |
142 | blkif->rings = kcalloc(blkif->nr_rings, sizeof(struct xen_blkif_ring), |
143 | GFP_KERNEL); | |
2fb1ef4f KRW |
144 | if (!blkif->rings) |
145 | return -ENOMEM; | |
146 | ||
147 | for (r = 0; r < blkif->nr_rings; r++) { | |
148 | struct xen_blkif_ring *ring = &blkif->rings[r]; | |
149 | ||
150 | spin_lock_init(&ring->blk_ring_lock); | |
151 | init_waitqueue_head(&ring->wq); | |
152 | INIT_LIST_HEAD(&ring->pending_free); | |
d4bf0065 BL |
153 | INIT_LIST_HEAD(&ring->persistent_purge_list); |
154 | INIT_WORK(&ring->persistent_purge_work, xen_blkbk_unmap_purged_grants); | |
155 | spin_lock_init(&ring->free_pages_lock); | |
156 | INIT_LIST_HEAD(&ring->free_pages); | |
2fb1ef4f KRW |
157 | |
158 | spin_lock_init(&ring->pending_free_lock); | |
159 | init_waitqueue_head(&ring->pending_free_wq); | |
160 | init_waitqueue_head(&ring->shutdown_wq); | |
161 | ring->blkif = blkif; | |
db6fbc10 | 162 | ring->st_print = jiffies; |
46464411 | 163 | ring->active = true; |
2fb1ef4f KRW |
164 | } |
165 | ||
166 | return 0; | |
4d05a28d KRW |
167 | } |
168 | ||
30fd1502 | 169 | static struct xen_blkif *xen_blkif_alloc(domid_t domid) |
ee9ff853 | 170 | { |
30fd1502 | 171 | struct xen_blkif *blkif; |
ee9ff853 | 172 | |
402b27f9 | 173 | BUILD_BUG_ON(MAX_INDIRECT_PAGES > BLKIF_MAX_INDIRECT_PAGES_PER_REQUEST); |
ee9ff853 | 174 | |
654dbef2 | 175 | blkif = kmem_cache_zalloc(xen_blkif_cachep, GFP_KERNEL); |
ee9ff853 KRW |
176 | if (!blkif) |
177 | return ERR_PTR(-ENOMEM); | |
178 | ||
ee9ff853 | 179 | blkif->domid = domid; |
ee9ff853 | 180 | atomic_set(&blkif->refcnt, 1); |
29bde093 | 181 | init_completion(&blkif->drain_complete); |
59795700 | 182 | INIT_WORK(&blkif->free_work, xen_blkif_deferred_free); |
ee9ff853 KRW |
183 | |
184 | return blkif; | |
185 | } | |
186 | ||
59795700 | 187 | static int xen_blkif_map(struct xen_blkif_ring *ring, grant_ref_t *gref, |
86839c56 | 188 | unsigned int nr_grefs, unsigned int evtchn) |
ee9ff853 KRW |
189 | { |
190 | int err; | |
59795700 | 191 | struct xen_blkif *blkif = ring->blkif; |
ee9ff853 KRW |
192 | |
193 | /* Already connected through? */ | |
59795700 | 194 | if (ring->irq) |
ee9ff853 KRW |
195 | return 0; |
196 | ||
86839c56 | 197 | err = xenbus_map_ring_valloc(blkif->be->dev, gref, nr_grefs, |
59795700 | 198 | &ring->blk_ring); |
2d073846 | 199 | if (err < 0) |
ee9ff853 | 200 | return err; |
ee9ff853 KRW |
201 | |
202 | switch (blkif->blk_protocol) { | |
203 | case BLKIF_PROTOCOL_NATIVE: | |
204 | { | |
205 | struct blkif_sring *sring; | |
59795700 BL |
206 | sring = (struct blkif_sring *)ring->blk_ring; |
207 | BACK_RING_INIT(&ring->blk_rings.native, sring, | |
67de5dfb | 208 | XEN_PAGE_SIZE * nr_grefs); |
ee9ff853 KRW |
209 | break; |
210 | } | |
211 | case BLKIF_PROTOCOL_X86_32: | |
212 | { | |
213 | struct blkif_x86_32_sring *sring_x86_32; | |
59795700 BL |
214 | sring_x86_32 = (struct blkif_x86_32_sring *)ring->blk_ring; |
215 | BACK_RING_INIT(&ring->blk_rings.x86_32, sring_x86_32, | |
67de5dfb | 216 | XEN_PAGE_SIZE * nr_grefs); |
ee9ff853 KRW |
217 | break; |
218 | } | |
219 | case BLKIF_PROTOCOL_X86_64: | |
220 | { | |
221 | struct blkif_x86_64_sring *sring_x86_64; | |
59795700 BL |
222 | sring_x86_64 = (struct blkif_x86_64_sring *)ring->blk_ring; |
223 | BACK_RING_INIT(&ring->blk_rings.x86_64, sring_x86_64, | |
67de5dfb | 224 | XEN_PAGE_SIZE * nr_grefs); |
ee9ff853 KRW |
225 | break; |
226 | } | |
227 | default: | |
228 | BUG(); | |
229 | } | |
230 | ||
8b6bf747 KRW |
231 | err = bind_interdomain_evtchn_to_irqhandler(blkif->domid, evtchn, |
232 | xen_blkif_be_int, 0, | |
59795700 | 233 | "blkif-backend", ring); |
ee9ff853 | 234 | if (err < 0) { |
59795700 BL |
235 | xenbus_unmap_ring_vfree(blkif->be->dev, ring->blk_ring); |
236 | ring->blk_rings.common.sring = NULL; | |
ee9ff853 KRW |
237 | return err; |
238 | } | |
59795700 | 239 | ring->irq = err; |
ee9ff853 KRW |
240 | |
241 | return 0; | |
242 | } | |
243 | ||
814d04e7 | 244 | static int xen_blkif_disconnect(struct xen_blkif *blkif) |
ee9ff853 | 245 | { |
f929d42c | 246 | struct pending_req *req, *n; |
2fb1ef4f | 247 | unsigned int j, r; |
dc52d783 | 248 | bool busy = false; |
f929d42c | 249 | |
2fb1ef4f KRW |
250 | for (r = 0; r < blkif->nr_rings; r++) { |
251 | struct xen_blkif_ring *ring = &blkif->rings[r]; | |
252 | unsigned int i = 0; | |
ee9ff853 | 253 | |
46464411 JG |
254 | if (!ring->active) |
255 | continue; | |
256 | ||
2fb1ef4f KRW |
257 | if (ring->xenblkd) { |
258 | kthread_stop(ring->xenblkd); | |
259 | wake_up(&ring->shutdown_wq); | |
2fb1ef4f | 260 | } |
ee9ff853 | 261 | |
2fb1ef4f KRW |
262 | /* The above kthread_stop() guarantees that at this point we |
263 | * don't have any discard_io or other_io requests. So, checking | |
264 | * for inflight IO is enough. | |
265 | */ | |
dc52d783 AL |
266 | if (atomic_read(&ring->inflight) > 0) { |
267 | busy = true; | |
268 | continue; | |
269 | } | |
ee9ff853 | 270 | |
2fb1ef4f KRW |
271 | if (ring->irq) { |
272 | unbind_from_irqhandler(ring->irq, ring); | |
273 | ring->irq = 0; | |
274 | } | |
814d04e7 | 275 | |
2fb1ef4f KRW |
276 | if (ring->blk_rings.common.sring) { |
277 | xenbus_unmap_ring_vfree(blkif->be->dev, ring->blk_ring); | |
278 | ring->blk_rings.common.sring = NULL; | |
279 | } | |
12ea7296 | 280 | |
2fb1ef4f KRW |
281 | /* Remove all persistent grants and the cache of ballooned pages. */ |
282 | xen_blkbk_free_caches(ring); | |
f929d42c | 283 | |
2fb1ef4f KRW |
284 | /* Check that there is no request in use */ |
285 | list_for_each_entry_safe(req, n, &ring->pending_free, free_list) { | |
286 | list_del(&req->free_list); | |
f929d42c | 287 | |
2fb1ef4f KRW |
288 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) |
289 | kfree(req->segments[j]); | |
f929d42c | 290 | |
2fb1ef4f KRW |
291 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) |
292 | kfree(req->indirect_pages[j]); | |
f929d42c | 293 | |
2fb1ef4f KRW |
294 | kfree(req); |
295 | i++; | |
296 | } | |
297 | ||
d4bf0065 BL |
298 | BUG_ON(atomic_read(&ring->persistent_gnt_in_use) != 0); |
299 | BUG_ON(!list_empty(&ring->persistent_purge_list)); | |
300 | BUG_ON(!RB_EMPTY_ROOT(&ring->persistent_gnts)); | |
301 | BUG_ON(!list_empty(&ring->free_pages)); | |
302 | BUG_ON(ring->free_pages_num != 0); | |
303 | BUG_ON(ring->persistent_gnt_c != 0); | |
2fb1ef4f | 304 | WARN_ON(i != (XEN_BLKIF_REQS_PER_PAGE * blkif->nr_ring_pages)); |
46464411 | 305 | ring->active = false; |
2fb1ef4f | 306 | } |
dc52d783 AL |
307 | if (busy) |
308 | return -EBUSY; | |
309 | ||
f929d42c | 310 | blkif->nr_ring_pages = 0; |
93bb277f BL |
311 | /* |
312 | * blkif->rings was allocated in connect_ring, so we should free it in | |
313 | * here. | |
314 | */ | |
315 | kfree(blkif->rings); | |
316 | blkif->rings = NULL; | |
317 | blkif->nr_rings = 0; | |
f929d42c | 318 | |
814d04e7 | 319 | return 0; |
ee9ff853 KRW |
320 | } |
321 | ||
2911758f | 322 | static void xen_blkif_free(struct xen_blkif *blkif) |
ee9ff853 | 323 | { |
71df1d7c | 324 | WARN_ON(xen_blkif_disconnect(blkif)); |
814d04e7 | 325 | xen_vbd_free(&blkif->vbd); |
71df1d7c JG |
326 | kfree(blkif->be->mode); |
327 | kfree(blkif->be); | |
bf0720c4 | 328 | |
ef753411 | 329 | /* Make sure everything is drained before shutting down */ |
8b6bf747 | 330 | kmem_cache_free(xen_blkif_cachep, blkif); |
ee9ff853 KRW |
331 | } |
332 | ||
8b6bf747 | 333 | int __init xen_blkif_interface_init(void) |
ee9ff853 | 334 | { |
8b6bf747 | 335 | xen_blkif_cachep = kmem_cache_create("blkif_cache", |
30fd1502 | 336 | sizeof(struct xen_blkif), |
8b6bf747 KRW |
337 | 0, 0, NULL); |
338 | if (!xen_blkif_cachep) | |
ee9ff853 KRW |
339 | return -ENOMEM; |
340 | ||
341 | return 0; | |
342 | } | |
4d05a28d | 343 | |
a1397fa3 | 344 | /* |
4d05a28d KRW |
345 | * sysfs interface for VBD I/O requests |
346 | */ | |
347 | ||
db6fbc10 | 348 | #define VBD_SHOW_ALLRING(name, format) \ |
4d05a28d KRW |
349 | static ssize_t show_##name(struct device *_dev, \ |
350 | struct device_attribute *attr, \ | |
351 | char *buf) \ | |
352 | { \ | |
353 | struct xenbus_device *dev = to_xenbus_device(_dev); \ | |
5cf6e4f6 | 354 | struct backend_info *be = dev_get_drvdata(&dev->dev); \ |
db6fbc10 BL |
355 | struct xen_blkif *blkif = be->blkif; \ |
356 | unsigned int i; \ | |
357 | unsigned long long result = 0; \ | |
4d05a28d | 358 | \ |
db6fbc10 BL |
359 | if (!blkif->rings) \ |
360 | goto out; \ | |
361 | \ | |
362 | for (i = 0; i < blkif->nr_rings; i++) { \ | |
363 | struct xen_blkif_ring *ring = &blkif->rings[i]; \ | |
364 | \ | |
365 | result += ring->st_##name; \ | |
366 | } \ | |
367 | \ | |
368 | out: \ | |
369 | return sprintf(buf, format, result); \ | |
4d05a28d | 370 | } \ |
5657a819 | 371 | static DEVICE_ATTR(name, 0444, show_##name, NULL) |
4d05a28d | 372 | |
db6fbc10 BL |
373 | VBD_SHOW_ALLRING(oo_req, "%llu\n"); |
374 | VBD_SHOW_ALLRING(rd_req, "%llu\n"); | |
375 | VBD_SHOW_ALLRING(wr_req, "%llu\n"); | |
376 | VBD_SHOW_ALLRING(f_req, "%llu\n"); | |
377 | VBD_SHOW_ALLRING(ds_req, "%llu\n"); | |
378 | VBD_SHOW_ALLRING(rd_sect, "%llu\n"); | |
379 | VBD_SHOW_ALLRING(wr_sect, "%llu\n"); | |
4d05a28d | 380 | |
3d814731 | 381 | static struct attribute *xen_vbdstat_attrs[] = { |
4d05a28d KRW |
382 | &dev_attr_oo_req.attr, |
383 | &dev_attr_rd_req.attr, | |
384 | &dev_attr_wr_req.attr, | |
24f567f9 | 385 | &dev_attr_f_req.attr, |
b3cb0d6a | 386 | &dev_attr_ds_req.attr, |
4d05a28d KRW |
387 | &dev_attr_rd_sect.attr, |
388 | &dev_attr_wr_sect.attr, | |
389 | NULL | |
390 | }; | |
391 | ||
53043948 | 392 | static const struct attribute_group xen_vbdstat_group = { |
4d05a28d | 393 | .name = "statistics", |
3d814731 | 394 | .attrs = xen_vbdstat_attrs, |
4d05a28d KRW |
395 | }; |
396 | ||
db6fbc10 BL |
397 | #define VBD_SHOW(name, format, args...) \ |
398 | static ssize_t show_##name(struct device *_dev, \ | |
399 | struct device_attribute *attr, \ | |
400 | char *buf) \ | |
401 | { \ | |
402 | struct xenbus_device *dev = to_xenbus_device(_dev); \ | |
403 | struct backend_info *be = dev_get_drvdata(&dev->dev); \ | |
404 | \ | |
405 | return sprintf(buf, format, ##args); \ | |
406 | } \ | |
5657a819 | 407 | static DEVICE_ATTR(name, 0444, show_##name, NULL) |
db6fbc10 | 408 | |
4d05a28d KRW |
409 | VBD_SHOW(physical_device, "%x:%x\n", be->major, be->minor); |
410 | VBD_SHOW(mode, "%s\n", be->mode); | |
411 | ||
2911758f | 412 | static int xenvbd_sysfs_addif(struct xenbus_device *dev) |
4d05a28d KRW |
413 | { |
414 | int error; | |
415 | ||
416 | error = device_create_file(&dev->dev, &dev_attr_physical_device); | |
d6091b21 | 417 | if (error) |
4d05a28d KRW |
418 | goto fail1; |
419 | ||
420 | error = device_create_file(&dev->dev, &dev_attr_mode); | |
421 | if (error) | |
422 | goto fail2; | |
423 | ||
3d814731 | 424 | error = sysfs_create_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
425 | if (error) |
426 | goto fail3; | |
427 | ||
428 | return 0; | |
429 | ||
3d814731 | 430 | fail3: sysfs_remove_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
431 | fail2: device_remove_file(&dev->dev, &dev_attr_mode); |
432 | fail1: device_remove_file(&dev->dev, &dev_attr_physical_device); | |
433 | return error; | |
434 | } | |
435 | ||
2911758f | 436 | static void xenvbd_sysfs_delif(struct xenbus_device *dev) |
4d05a28d | 437 | { |
3d814731 | 438 | sysfs_remove_group(&dev->dev.kobj, &xen_vbdstat_group); |
4d05a28d KRW |
439 | device_remove_file(&dev->dev, &dev_attr_mode); |
440 | device_remove_file(&dev->dev, &dev_attr_physical_device); | |
441 | } | |
442 | ||
42c7841d | 443 | |
3d814731 | 444 | static void xen_vbd_free(struct xen_vbd *vbd) |
42c7841d KRW |
445 | { |
446 | if (vbd->bdev) | |
447 | blkdev_put(vbd->bdev, vbd->readonly ? FMODE_READ : FMODE_WRITE); | |
448 | vbd->bdev = NULL; | |
449 | } | |
450 | ||
3d814731 KRW |
451 | static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle, |
452 | unsigned major, unsigned minor, int readonly, | |
453 | int cdrom) | |
42c7841d | 454 | { |
3d814731 | 455 | struct xen_vbd *vbd; |
42c7841d | 456 | struct block_device *bdev; |
24f567f9 | 457 | struct request_queue *q; |
42c7841d KRW |
458 | |
459 | vbd = &blkif->vbd; | |
460 | vbd->handle = handle; | |
461 | vbd->readonly = readonly; | |
462 | vbd->type = 0; | |
463 | ||
464 | vbd->pdevice = MKDEV(major, minor); | |
465 | ||
466 | bdev = blkdev_get_by_dev(vbd->pdevice, vbd->readonly ? | |
467 | FMODE_READ : FMODE_WRITE, NULL); | |
468 | ||
469 | if (IS_ERR(bdev)) { | |
77387b82 | 470 | pr_warn("xen_vbd_create: device %08x could not be opened\n", |
42c7841d KRW |
471 | vbd->pdevice); |
472 | return -ENOENT; | |
473 | } | |
474 | ||
475 | vbd->bdev = bdev; | |
42c7841d | 476 | if (vbd->bdev->bd_disk == NULL) { |
77387b82 | 477 | pr_warn("xen_vbd_create: device %08x doesn't exist\n", |
42c7841d | 478 | vbd->pdevice); |
3d814731 | 479 | xen_vbd_free(vbd); |
42c7841d KRW |
480 | return -ENOENT; |
481 | } | |
6464920a | 482 | vbd->size = vbd_sz(vbd); |
42c7841d KRW |
483 | |
484 | if (vbd->bdev->bd_disk->flags & GENHD_FL_CD || cdrom) | |
485 | vbd->type |= VDISK_CDROM; | |
486 | if (vbd->bdev->bd_disk->flags & GENHD_FL_REMOVABLE) | |
487 | vbd->type |= VDISK_REMOVABLE; | |
488 | ||
24f567f9 | 489 | q = bdev_get_queue(bdev); |
c888a8f9 | 490 | if (q && test_bit(QUEUE_FLAG_WC, &q->queue_flags)) |
24f567f9 KRW |
491 | vbd->flush_support = true; |
492 | ||
288dab8a | 493 | if (q && blk_queue_secure_erase(q)) |
5ea42986 KRW |
494 | vbd->discard_secure = true; |
495 | ||
77387b82 | 496 | pr_debug("Successful creation of handle=%04x (dom=%u)\n", |
42c7841d KRW |
497 | handle, blkif->domid); |
498 | return 0; | |
499 | } | |
8b6bf747 | 500 | static int xen_blkbk_remove(struct xenbus_device *dev) |
4d05a28d | 501 | { |
5cf6e4f6 | 502 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
4d05a28d | 503 | |
77387b82 | 504 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); |
4d05a28d KRW |
505 | |
506 | if (be->major || be->minor) | |
507 | xenvbd_sysfs_delif(dev); | |
508 | ||
509 | if (be->backend_watch.node) { | |
510 | unregister_xenbus_watch(&be->backend_watch); | |
511 | kfree(be->backend_watch.node); | |
512 | be->backend_watch.node = NULL; | |
513 | } | |
514 | ||
814d04e7 VP |
515 | dev_set_drvdata(&dev->dev, NULL); |
516 | ||
2d4456c7 | 517 | if (be->blkif) { |
8b6bf747 | 518 | xen_blkif_disconnect(be->blkif); |
4d05a28d | 519 | |
2d4456c7 GS |
520 | /* Put the reference we set in xen_blkif_alloc(). */ |
521 | xen_blkif_put(be->blkif); | |
522 | } | |
523 | ||
4d05a28d KRW |
524 | return 0; |
525 | } | |
526 | ||
24f567f9 KRW |
527 | int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt, |
528 | struct backend_info *be, int state) | |
4d05a28d KRW |
529 | { |
530 | struct xenbus_device *dev = be->dev; | |
531 | int err; | |
532 | ||
24f567f9 | 533 | err = xenbus_printf(xbt, dev->nodename, "feature-flush-cache", |
4d05a28d KRW |
534 | "%d", state); |
535 | if (err) | |
3389bb8b | 536 | dev_warn(&dev->dev, "writing feature-flush-cache (%d)", err); |
4d05a28d KRW |
537 | |
538 | return err; | |
539 | } | |
540 | ||
3389bb8b | 541 | static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be) |
b3cb0d6a LD |
542 | { |
543 | struct xenbus_device *dev = be->dev; | |
544 | struct xen_blkif *blkif = be->blkif; | |
b3cb0d6a | 545 | int err; |
8235777b | 546 | int state = 0; |
4dae7670 KRW |
547 | struct block_device *bdev = be->blkif->vbd.bdev; |
548 | struct request_queue *q = bdev_get_queue(bdev); | |
549 | ||
8235777b | 550 | if (!xenbus_read_unsigned(dev->nodename, "discard-enable", 1)) |
c926b701 OH |
551 | return; |
552 | ||
4dae7670 KRW |
553 | if (blk_queue_discard(q)) { |
554 | err = xenbus_printf(xbt, dev->nodename, | |
555 | "discard-granularity", "%u", | |
556 | q->limits.discard_granularity); | |
557 | if (err) { | |
3389bb8b KRW |
558 | dev_warn(&dev->dev, "writing discard-granularity (%d)", err); |
559 | return; | |
4dae7670 KRW |
560 | } |
561 | err = xenbus_printf(xbt, dev->nodename, | |
562 | "discard-alignment", "%u", | |
563 | q->limits.discard_alignment); | |
564 | if (err) { | |
3389bb8b KRW |
565 | dev_warn(&dev->dev, "writing discard-alignment (%d)", err); |
566 | return; | |
b3cb0d6a | 567 | } |
4dae7670 KRW |
568 | state = 1; |
569 | /* Optional. */ | |
570 | err = xenbus_printf(xbt, dev->nodename, | |
571 | "discard-secure", "%d", | |
572 | blkif->vbd.discard_secure); | |
573 | if (err) { | |
a71e23d9 | 574 | dev_warn(&dev->dev, "writing discard-secure (%d)", err); |
3389bb8b | 575 | return; |
b3cb0d6a | 576 | } |
b3cb0d6a | 577 | } |
b3cb0d6a LD |
578 | err = xenbus_printf(xbt, dev->nodename, "feature-discard", |
579 | "%d", state); | |
580 | if (err) | |
3389bb8b | 581 | dev_warn(&dev->dev, "writing feature-discard (%d)", err); |
b3cb0d6a | 582 | } |
29bde093 KRW |
583 | int xen_blkbk_barrier(struct xenbus_transaction xbt, |
584 | struct backend_info *be, int state) | |
585 | { | |
586 | struct xenbus_device *dev = be->dev; | |
587 | int err; | |
588 | ||
589 | err = xenbus_printf(xbt, dev->nodename, "feature-barrier", | |
590 | "%d", state); | |
591 | if (err) | |
3389bb8b | 592 | dev_warn(&dev->dev, "writing feature-barrier (%d)", err); |
29bde093 KRW |
593 | |
594 | return err; | |
595 | } | |
b3cb0d6a | 596 | |
01f37f2d | 597 | /* |
4d05a28d KRW |
598 | * Entry point to this code when a new device is created. Allocate the basic |
599 | * structures, and watch the store waiting for the hotplug scripts to tell us | |
600 | * the device's physical major and minor numbers. Switch to InitWait. | |
601 | */ | |
8b6bf747 KRW |
602 | static int xen_blkbk_probe(struct xenbus_device *dev, |
603 | const struct xenbus_device_id *id) | |
4d05a28d KRW |
604 | { |
605 | int err; | |
606 | struct backend_info *be = kzalloc(sizeof(struct backend_info), | |
607 | GFP_KERNEL); | |
77387b82 TC |
608 | |
609 | /* match the pr_debug in xen_blkbk_remove */ | |
610 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); | |
611 | ||
4d05a28d KRW |
612 | if (!be) { |
613 | xenbus_dev_fatal(dev, -ENOMEM, | |
614 | "allocating backend structure"); | |
615 | return -ENOMEM; | |
616 | } | |
617 | be->dev = dev; | |
5cf6e4f6 | 618 | dev_set_drvdata(&dev->dev, be); |
4d05a28d | 619 | |
8b6bf747 | 620 | be->blkif = xen_blkif_alloc(dev->otherend_id); |
4d05a28d KRW |
621 | if (IS_ERR(be->blkif)) { |
622 | err = PTR_ERR(be->blkif); | |
623 | be->blkif = NULL; | |
624 | xenbus_dev_fatal(dev, err, "creating block interface"); | |
625 | goto fail; | |
626 | } | |
627 | ||
5a705845 JB |
628 | err = xenbus_printf(XBT_NIL, dev->nodename, |
629 | "feature-max-indirect-segments", "%u", | |
630 | MAX_INDIRECT_SEGMENTS); | |
631 | if (err) | |
632 | dev_warn(&dev->dev, | |
633 | "writing %s/feature-max-indirect-segments (%d)", | |
634 | dev->nodename, err); | |
635 | ||
d62d8600 BL |
636 | /* Multi-queue: advertise how many queues are supported by us.*/ |
637 | err = xenbus_printf(XBT_NIL, dev->nodename, | |
638 | "multi-queue-max-queues", "%u", xenblk_max_queues); | |
639 | if (err) | |
640 | pr_warn("Error writing multi-queue-max-queues\n"); | |
641 | ||
4d05a28d KRW |
642 | /* setup back pointer */ |
643 | be->blkif->be = be; | |
644 | ||
88122933 JF |
645 | err = xenbus_watch_pathfmt(dev, &be->backend_watch, backend_changed, |
646 | "%s/%s", dev->nodename, "physical-device"); | |
4d05a28d KRW |
647 | if (err) |
648 | goto fail; | |
649 | ||
86839c56 BL |
650 | err = xenbus_printf(XBT_NIL, dev->nodename, "max-ring-page-order", "%u", |
651 | xen_blkif_max_ring_order); | |
652 | if (err) | |
653 | pr_warn("%s write out 'max-ring-page-order' failed\n", __func__); | |
654 | ||
4d05a28d KRW |
655 | err = xenbus_switch_state(dev, XenbusStateInitWait); |
656 | if (err) | |
657 | goto fail; | |
658 | ||
659 | return 0; | |
660 | ||
661 | fail: | |
77387b82 | 662 | pr_warn("%s failed\n", __func__); |
8b6bf747 | 663 | xen_blkbk_remove(dev); |
4d05a28d KRW |
664 | return err; |
665 | } | |
666 | ||
667 | ||
01f37f2d | 668 | /* |
4d05a28d KRW |
669 | * Callback received when the hotplug scripts have placed the physical-device |
670 | * node. Read it and the mode node, and create a vbd. If the frontend is | |
671 | * ready, connect. | |
672 | */ | |
673 | static void backend_changed(struct xenbus_watch *watch, | |
5584ea25 | 674 | const char *path, const char *token) |
4d05a28d KRW |
675 | { |
676 | int err; | |
677 | unsigned major; | |
678 | unsigned minor; | |
679 | struct backend_info *be | |
680 | = container_of(watch, struct backend_info, backend_watch); | |
681 | struct xenbus_device *dev = be->dev; | |
682 | int cdrom = 0; | |
9d092603 | 683 | unsigned long handle; |
4d05a28d KRW |
684 | char *device_type; |
685 | ||
77387b82 | 686 | pr_debug("%s %p %d\n", __func__, dev, dev->otherend_id); |
4d05a28d KRW |
687 | |
688 | err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x", | |
689 | &major, &minor); | |
690 | if (XENBUS_EXIST_ERR(err)) { | |
01f37f2d KRW |
691 | /* |
692 | * Since this watch will fire once immediately after it is | |
693 | * registered, we expect this. Ignore it, and wait for the | |
694 | * hotplug scripts. | |
695 | */ | |
4d05a28d KRW |
696 | return; |
697 | } | |
698 | if (err != 2) { | |
699 | xenbus_dev_fatal(dev, err, "reading physical-device"); | |
700 | return; | |
701 | } | |
702 | ||
9d092603 JB |
703 | if (be->major | be->minor) { |
704 | if (be->major != major || be->minor != minor) | |
77387b82 | 705 | pr_warn("changing physical device (from %x:%x to %x:%x) not supported.\n", |
9d092603 | 706 | be->major, be->minor, major, minor); |
4d05a28d KRW |
707 | return; |
708 | } | |
709 | ||
710 | be->mode = xenbus_read(XBT_NIL, dev->nodename, "mode", NULL); | |
711 | if (IS_ERR(be->mode)) { | |
712 | err = PTR_ERR(be->mode); | |
713 | be->mode = NULL; | |
714 | xenbus_dev_fatal(dev, err, "reading mode"); | |
715 | return; | |
716 | } | |
717 | ||
718 | device_type = xenbus_read(XBT_NIL, dev->otherend, "device-type", NULL); | |
719 | if (!IS_ERR(device_type)) { | |
720 | cdrom = strcmp(device_type, "cdrom") == 0; | |
721 | kfree(device_type); | |
722 | } | |
723 | ||
9d092603 | 724 | /* Front end dir is a number, which is used as the handle. */ |
bb8e0e84 | 725 | err = kstrtoul(strrchr(dev->otherend, '/') + 1, 0, &handle); |
aea305e1 JB |
726 | if (err) { |
727 | kfree(be->mode); | |
728 | be->mode = NULL; | |
9d092603 | 729 | return; |
aea305e1 | 730 | } |
4d05a28d | 731 | |
9d092603 JB |
732 | be->major = major; |
733 | be->minor = minor; | |
4d05a28d | 734 | |
9d092603 JB |
735 | err = xen_vbd_create(be->blkif, handle, major, minor, |
736 | !strchr(be->mode, 'w'), cdrom); | |
4d05a28d | 737 | |
9d092603 JB |
738 | if (err) |
739 | xenbus_dev_fatal(dev, err, "creating vbd structure"); | |
740 | else { | |
4d05a28d KRW |
741 | err = xenvbd_sysfs_addif(dev); |
742 | if (err) { | |
3d814731 | 743 | xen_vbd_free(&be->blkif->vbd); |
4d05a28d | 744 | xenbus_dev_fatal(dev, err, "creating sysfs entries"); |
4d05a28d | 745 | } |
9d092603 | 746 | } |
4d05a28d | 747 | |
9d092603 JB |
748 | if (err) { |
749 | kfree(be->mode); | |
750 | be->mode = NULL; | |
751 | be->major = 0; | |
752 | be->minor = 0; | |
753 | } else { | |
4d05a28d | 754 | /* We're potentially connected now */ |
8b6bf747 | 755 | xen_update_blkif_status(be->blkif); |
4d05a28d KRW |
756 | } |
757 | } | |
758 | ||
759 | ||
01f37f2d | 760 | /* |
4d05a28d KRW |
761 | * Callback received when the frontend's state changes. |
762 | */ | |
763 | static void frontend_changed(struct xenbus_device *dev, | |
764 | enum xenbus_state frontend_state) | |
765 | { | |
5cf6e4f6 | 766 | struct backend_info *be = dev_get_drvdata(&dev->dev); |
4d05a28d KRW |
767 | int err; |
768 | ||
77387b82 | 769 | pr_debug("%s %p %s\n", __func__, dev, xenbus_strstate(frontend_state)); |
4d05a28d KRW |
770 | |
771 | switch (frontend_state) { | |
772 | case XenbusStateInitialising: | |
773 | if (dev->state == XenbusStateClosed) { | |
77387b82 | 774 | pr_info("%s: prepare for reconnect\n", dev->nodename); |
4d05a28d KRW |
775 | xenbus_switch_state(dev, XenbusStateInitWait); |
776 | } | |
777 | break; | |
778 | ||
779 | case XenbusStateInitialised: | |
780 | case XenbusStateConnected: | |
01f37f2d KRW |
781 | /* |
782 | * Ensure we connect even when two watches fire in | |
42b2aa86 | 783 | * close succession and we miss the intermediate value |
01f37f2d KRW |
784 | * of frontend_state. |
785 | */ | |
4d05a28d KRW |
786 | if (dev->state == XenbusStateConnected) |
787 | break; | |
788 | ||
01f37f2d KRW |
789 | /* |
790 | * Enforce precondition before potential leak point. | |
1bc05b0a | 791 | * xen_blkif_disconnect() is idempotent. |
313d7b00 | 792 | */ |
814d04e7 VP |
793 | err = xen_blkif_disconnect(be->blkif); |
794 | if (err) { | |
795 | xenbus_dev_fatal(dev, err, "pending I/O"); | |
796 | break; | |
797 | } | |
313d7b00 | 798 | |
4d05a28d | 799 | err = connect_ring(be); |
2d0382fa KRW |
800 | if (err) { |
801 | /* | |
802 | * Clean up so that memory resources can be used by | |
803 | * other devices. connect_ring reported already error. | |
804 | */ | |
805 | xen_blkif_disconnect(be->blkif); | |
4d05a28d | 806 | break; |
2d0382fa | 807 | } |
8b6bf747 | 808 | xen_update_blkif_status(be->blkif); |
4d05a28d KRW |
809 | break; |
810 | ||
811 | case XenbusStateClosing: | |
4d05a28d KRW |
812 | xenbus_switch_state(dev, XenbusStateClosing); |
813 | break; | |
814 | ||
815 | case XenbusStateClosed: | |
6f5986bc | 816 | xen_blkif_disconnect(be->blkif); |
4d05a28d KRW |
817 | xenbus_switch_state(dev, XenbusStateClosed); |
818 | if (xenbus_dev_is_online(dev)) | |
819 | break; | |
3f2c9405 BVA |
820 | /* fall through */ |
821 | /* if not online */ | |
4d05a28d | 822 | case XenbusStateUnknown: |
1bc05b0a | 823 | /* implies xen_blkif_disconnect() via xen_blkbk_remove() */ |
4d05a28d KRW |
824 | device_unregister(&dev->dev); |
825 | break; | |
826 | ||
827 | default: | |
828 | xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend", | |
829 | frontend_state); | |
830 | break; | |
831 | } | |
832 | } | |
833 | ||
834 | ||
835 | /* ** Connection ** */ | |
836 | ||
837 | ||
01f37f2d | 838 | /* |
4d05a28d KRW |
839 | * Write the physical details regarding the block device to the store, and |
840 | * switch to Connected state. | |
841 | */ | |
842 | static void connect(struct backend_info *be) | |
843 | { | |
844 | struct xenbus_transaction xbt; | |
845 | int err; | |
846 | struct xenbus_device *dev = be->dev; | |
847 | ||
77387b82 | 848 | pr_debug("%s %s\n", __func__, dev->otherend); |
4d05a28d KRW |
849 | |
850 | /* Supply the information about the device the frontend needs */ | |
851 | again: | |
852 | err = xenbus_transaction_start(&xbt); | |
853 | if (err) { | |
854 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
855 | return; | |
856 | } | |
857 | ||
3389bb8b KRW |
858 | /* If we can't advertise it is OK. */ |
859 | xen_blkbk_flush_diskcache(xbt, be, be->blkif->vbd.flush_support); | |
4d05a28d | 860 | |
3389bb8b | 861 | xen_blkbk_discard(xbt, be); |
b3cb0d6a | 862 | |
3389bb8b | 863 | xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support); |
29bde093 | 864 | |
0a8704a5 RPM |
865 | err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u", 1); |
866 | if (err) { | |
867 | xenbus_dev_fatal(dev, err, "writing %s/feature-persistent", | |
868 | dev->nodename); | |
869 | goto abort; | |
870 | } | |
871 | ||
4d05a28d | 872 | err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu", |
42c7841d | 873 | (unsigned long long)vbd_sz(&be->blkif->vbd)); |
4d05a28d KRW |
874 | if (err) { |
875 | xenbus_dev_fatal(dev, err, "writing %s/sectors", | |
876 | dev->nodename); | |
877 | goto abort; | |
878 | } | |
879 | ||
880 | /* FIXME: use a typename instead */ | |
881 | err = xenbus_printf(xbt, dev->nodename, "info", "%u", | |
42c7841d KRW |
882 | be->blkif->vbd.type | |
883 | (be->blkif->vbd.readonly ? VDISK_READONLY : 0)); | |
4d05a28d KRW |
884 | if (err) { |
885 | xenbus_dev_fatal(dev, err, "writing %s/info", | |
886 | dev->nodename); | |
887 | goto abort; | |
888 | } | |
889 | err = xenbus_printf(xbt, dev->nodename, "sector-size", "%lu", | |
42c7841d KRW |
890 | (unsigned long) |
891 | bdev_logical_block_size(be->blkif->vbd.bdev)); | |
4d05a28d KRW |
892 | if (err) { |
893 | xenbus_dev_fatal(dev, err, "writing %s/sector-size", | |
894 | dev->nodename); | |
895 | goto abort; | |
896 | } | |
7c4d7d71 SB |
897 | err = xenbus_printf(xbt, dev->nodename, "physical-sector-size", "%u", |
898 | bdev_physical_block_size(be->blkif->vbd.bdev)); | |
899 | if (err) | |
900 | xenbus_dev_error(dev, err, "writing %s/physical-sector-size", | |
901 | dev->nodename); | |
4d05a28d KRW |
902 | |
903 | err = xenbus_transaction_end(xbt, 0); | |
904 | if (err == -EAGAIN) | |
905 | goto again; | |
906 | if (err) | |
907 | xenbus_dev_fatal(dev, err, "ending transaction"); | |
908 | ||
909 | err = xenbus_switch_state(dev, XenbusStateConnected); | |
910 | if (err) | |
08b8bfc1 | 911 | xenbus_dev_fatal(dev, err, "%s: switching to Connected state", |
4d05a28d KRW |
912 | dev->nodename); |
913 | ||
914 | return; | |
915 | abort: | |
916 | xenbus_transaction_end(xbt, 1); | |
917 | } | |
918 | ||
2fb1ef4f KRW |
919 | /* |
920 | * Each ring may have multi pages, depends on "ring-page-order". | |
921 | */ | |
922 | static int read_per_ring_refs(struct xen_blkif_ring *ring, const char *dir) | |
4d05a28d | 923 | { |
9cce2914 | 924 | unsigned int ring_ref[XENBUS_MAX_RING_GRANTS]; |
69b91ede BL |
925 | struct pending_req *req, *n; |
926 | int err, i, j; | |
2fb1ef4f KRW |
927 | struct xen_blkif *blkif = ring->blkif; |
928 | struct xenbus_device *dev = blkif->be->dev; | |
929 | unsigned int ring_page_order, nr_grefs, evtchn; | |
4d05a28d | 930 | |
2fb1ef4f | 931 | err = xenbus_scanf(XBT_NIL, dir, "event-channel", "%u", |
86839c56 BL |
932 | &evtchn); |
933 | if (err != 1) { | |
934 | err = -EINVAL; | |
2fb1ef4f | 935 | xenbus_dev_fatal(dev, err, "reading %s/event-channel", dir); |
4d05a28d KRW |
936 | return err; |
937 | } | |
86839c56 BL |
938 | |
939 | err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-page-order", "%u", | |
940 | &ring_page_order); | |
941 | if (err != 1) { | |
2fb1ef4f | 942 | err = xenbus_scanf(XBT_NIL, dir, "ring-ref", "%u", &ring_ref[0]); |
86839c56 BL |
943 | if (err != 1) { |
944 | err = -EINVAL; | |
2fb1ef4f | 945 | xenbus_dev_fatal(dev, err, "reading %s/ring-ref", dir); |
86839c56 BL |
946 | return err; |
947 | } | |
948 | nr_grefs = 1; | |
86839c56 BL |
949 | } else { |
950 | unsigned int i; | |
951 | ||
952 | if (ring_page_order > xen_blkif_max_ring_order) { | |
953 | err = -EINVAL; | |
954 | xenbus_dev_fatal(dev, err, "%s/request %d ring page order exceed max:%d", | |
2fb1ef4f | 955 | dir, ring_page_order, |
86839c56 BL |
956 | xen_blkif_max_ring_order); |
957 | return err; | |
958 | } | |
959 | ||
960 | nr_grefs = 1 << ring_page_order; | |
961 | for (i = 0; i < nr_grefs; i++) { | |
962 | char ring_ref_name[RINGREF_NAME_LEN]; | |
963 | ||
964 | snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); | |
2fb1ef4f | 965 | err = xenbus_scanf(XBT_NIL, dir, ring_ref_name, |
86839c56 BL |
966 | "%u", &ring_ref[i]); |
967 | if (err != 1) { | |
968 | err = -EINVAL; | |
969 | xenbus_dev_fatal(dev, err, "reading %s/%s", | |
2fb1ef4f | 970 | dir, ring_ref_name); |
86839c56 BL |
971 | return err; |
972 | } | |
86839c56 BL |
973 | } |
974 | } | |
2fb1ef4f | 975 | blkif->nr_ring_pages = nr_grefs; |
4d05a28d | 976 | |
86839c56 | 977 | for (i = 0; i < nr_grefs * XEN_BLKIF_REQS_PER_PAGE; i++) { |
69b91ede BL |
978 | req = kzalloc(sizeof(*req), GFP_KERNEL); |
979 | if (!req) | |
980 | goto fail; | |
59795700 | 981 | list_add_tail(&req->free_list, &ring->pending_free); |
69b91ede BL |
982 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { |
983 | req->segments[j] = kzalloc(sizeof(*req->segments[0]), GFP_KERNEL); | |
984 | if (!req->segments[j]) | |
985 | goto fail; | |
986 | } | |
987 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) { | |
988 | req->indirect_pages[j] = kzalloc(sizeof(*req->indirect_pages[0]), | |
989 | GFP_KERNEL); | |
990 | if (!req->indirect_pages[j]) | |
991 | goto fail; | |
992 | } | |
993 | } | |
994 | ||
4d05a28d | 995 | /* Map the shared frame, irq etc. */ |
59795700 | 996 | err = xen_blkif_map(ring, ring_ref, nr_grefs, evtchn); |
4d05a28d | 997 | if (err) { |
86839c56 | 998 | xenbus_dev_fatal(dev, err, "mapping ring-ref port %u", evtchn); |
4d05a28d KRW |
999 | return err; |
1000 | } | |
1001 | ||
1002 | return 0; | |
69b91ede BL |
1003 | |
1004 | fail: | |
59795700 | 1005 | list_for_each_entry_safe(req, n, &ring->pending_free, free_list) { |
69b91ede BL |
1006 | list_del(&req->free_list); |
1007 | for (j = 0; j < MAX_INDIRECT_SEGMENTS; j++) { | |
1008 | if (!req->segments[j]) | |
1009 | break; | |
1010 | kfree(req->segments[j]); | |
1011 | } | |
1012 | for (j = 0; j < MAX_INDIRECT_PAGES; j++) { | |
1013 | if (!req->indirect_pages[j]) | |
1014 | break; | |
1015 | kfree(req->indirect_pages[j]); | |
1016 | } | |
1017 | kfree(req); | |
1018 | } | |
1019 | return -ENOMEM; | |
2fb1ef4f KRW |
1020 | |
1021 | } | |
1022 | ||
1023 | static int connect_ring(struct backend_info *be) | |
1024 | { | |
1025 | struct xenbus_device *dev = be->dev; | |
1026 | unsigned int pers_grants; | |
1027 | char protocol[64] = ""; | |
1028 | int err, i; | |
1029 | char *xspath; | |
1030 | size_t xspathsize; | |
1031 | const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */ | |
d62d8600 | 1032 | unsigned int requested_num_queues = 0; |
2fb1ef4f KRW |
1033 | |
1034 | pr_debug("%s %s\n", __func__, dev->otherend); | |
1035 | ||
1036 | be->blkif->blk_protocol = BLKIF_PROTOCOL_DEFAULT; | |
6694389a JB |
1037 | err = xenbus_scanf(XBT_NIL, dev->otherend, "protocol", |
1038 | "%63s", protocol); | |
1039 | if (err <= 0) | |
2fb1ef4f KRW |
1040 | strcpy(protocol, "unspecified, assuming default"); |
1041 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_NATIVE)) | |
1042 | be->blkif->blk_protocol = BLKIF_PROTOCOL_NATIVE; | |
1043 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_32)) | |
1044 | be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_32; | |
1045 | else if (0 == strcmp(protocol, XEN_IO_PROTO_ABI_X86_64)) | |
1046 | be->blkif->blk_protocol = BLKIF_PROTOCOL_X86_64; | |
1047 | else { | |
1048 | xenbus_dev_fatal(dev, err, "unknown fe protocol %s", protocol); | |
bde21f73 | 1049 | return -ENOSYS; |
2fb1ef4f | 1050 | } |
8235777b JG |
1051 | pers_grants = xenbus_read_unsigned(dev->otherend, "feature-persistent", |
1052 | 0); | |
2fb1ef4f KRW |
1053 | be->blkif->vbd.feature_gnt_persistent = pers_grants; |
1054 | be->blkif->vbd.overflow_max_grants = 0; | |
1055 | ||
d62d8600 BL |
1056 | /* |
1057 | * Read the number of hardware queues from frontend. | |
1058 | */ | |
8235777b JG |
1059 | requested_num_queues = xenbus_read_unsigned(dev->otherend, |
1060 | "multi-queue-num-queues", | |
1061 | 1); | |
1062 | if (requested_num_queues > xenblk_max_queues | |
1063 | || requested_num_queues == 0) { | |
1064 | /* Buggy or malicious guest. */ | |
1065 | xenbus_dev_fatal(dev, err, | |
1066 | "guest requested %u queues, exceeding the maximum of %u.", | |
1067 | requested_num_queues, xenblk_max_queues); | |
1068 | return -ENOSYS; | |
d62d8600 BL |
1069 | } |
1070 | be->blkif->nr_rings = requested_num_queues; | |
1071 | if (xen_blkif_alloc_rings(be->blkif)) | |
1072 | return -ENOMEM; | |
1073 | ||
2fb1ef4f KRW |
1074 | pr_info("%s: using %d queues, protocol %d (%s) %s\n", dev->nodename, |
1075 | be->blkif->nr_rings, be->blkif->blk_protocol, protocol, | |
1076 | pers_grants ? "persistent grants" : ""); | |
1077 | ||
1078 | if (be->blkif->nr_rings == 1) | |
1079 | return read_per_ring_refs(&be->blkif->rings[0], dev->otherend); | |
1080 | else { | |
1081 | xspathsize = strlen(dev->otherend) + xenstore_path_ext_size; | |
1082 | xspath = kmalloc(xspathsize, GFP_KERNEL); | |
1083 | if (!xspath) { | |
1084 | xenbus_dev_fatal(dev, -ENOMEM, "reading ring references"); | |
1085 | return -ENOMEM; | |
1086 | } | |
1087 | ||
1088 | for (i = 0; i < be->blkif->nr_rings; i++) { | |
1089 | memset(xspath, 0, xspathsize); | |
1090 | snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend, i); | |
1091 | err = read_per_ring_refs(&be->blkif->rings[i], xspath); | |
1092 | if (err) { | |
1093 | kfree(xspath); | |
1094 | return err; | |
1095 | } | |
1096 | } | |
1097 | kfree(xspath); | |
1098 | } | |
1099 | return 0; | |
4d05a28d KRW |
1100 | } |
1101 | ||
8b6bf747 | 1102 | static const struct xenbus_device_id xen_blkbk_ids[] = { |
4d05a28d KRW |
1103 | { "vbd" }, |
1104 | { "" } | |
1105 | }; | |
1106 | ||
95afae48 DV |
1107 | static struct xenbus_driver xen_blkbk_driver = { |
1108 | .ids = xen_blkbk_ids, | |
8b6bf747 KRW |
1109 | .probe = xen_blkbk_probe, |
1110 | .remove = xen_blkbk_remove, | |
4d05a28d | 1111 | .otherend_changed = frontend_changed |
95afae48 | 1112 | }; |
4d05a28d | 1113 | |
8b6bf747 | 1114 | int xen_blkif_xenbus_init(void) |
4d05a28d | 1115 | { |
73db144b | 1116 | return xenbus_register_backend(&xen_blkbk_driver); |
4d05a28d | 1117 | } |