Commit | Line | Data |
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9f27ee59 JF |
1 | /* |
2 | * blkfront.c | |
3 | * | |
4 | * XenLinux virtual block device driver. | |
5 | * | |
6 | * Copyright (c) 2003-2004, Keir Fraser & Steve Hand | |
7 | * Modifications by Mark A. Williamson are (c) Intel Research Cambridge | |
8 | * Copyright (c) 2004, Christian Limpach | |
9 | * Copyright (c) 2004, Andrew Warfield | |
10 | * Copyright (c) 2005, Christopher Clark | |
11 | * Copyright (c) 2005, XenSource Ltd | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or | |
14 | * modify it under the terms of the GNU General Public License version 2 | |
15 | * as published by the Free Software Foundation; or, when distributed | |
16 | * separately from the Linux kernel or incorporated into other | |
17 | * software packages, subject to the following license: | |
18 | * | |
19 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
20 | * of this source file (the "Software"), to deal in the Software without | |
21 | * restriction, including without limitation the rights to use, copy, modify, | |
22 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
23 | * and to permit persons to whom the Software is furnished to do so, subject to | |
24 | * the following conditions: | |
25 | * | |
26 | * The above copyright notice and this permission notice shall be included in | |
27 | * all copies or substantial portions of the Software. | |
28 | * | |
29 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
30 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
31 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
32 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
33 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
34 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
35 | * IN THE SOFTWARE. | |
36 | */ | |
37 | ||
38 | #include <linux/interrupt.h> | |
39 | #include <linux/blkdev.h> | |
597592d9 | 40 | #include <linux/hdreg.h> |
440a01a7 | 41 | #include <linux/cdrom.h> |
9f27ee59 | 42 | #include <linux/module.h> |
5a0e3ad6 | 43 | #include <linux/slab.h> |
2a48fc0a | 44 | #include <linux/mutex.h> |
9e973e64 | 45 | #include <linux/scatterlist.h> |
34ae2e47 | 46 | #include <linux/bitmap.h> |
155b7edb | 47 | #include <linux/list.h> |
9f27ee59 | 48 | |
1ccbf534 | 49 | #include <xen/xen.h> |
9f27ee59 JF |
50 | #include <xen/xenbus.h> |
51 | #include <xen/grant_table.h> | |
52 | #include <xen/events.h> | |
53 | #include <xen/page.h> | |
c1c5413a | 54 | #include <xen/platform_pci.h> |
9f27ee59 JF |
55 | |
56 | #include <xen/interface/grant_table.h> | |
57 | #include <xen/interface/io/blkif.h> | |
3e334239 | 58 | #include <xen/interface/io/protocols.h> |
9f27ee59 JF |
59 | |
60 | #include <asm/xen/hypervisor.h> | |
61 | ||
62 | enum blkif_state { | |
63 | BLKIF_STATE_DISCONNECTED, | |
64 | BLKIF_STATE_CONNECTED, | |
65 | BLKIF_STATE_SUSPENDED, | |
66 | }; | |
67 | ||
0a8704a5 RPM |
68 | struct grant { |
69 | grant_ref_t gref; | |
70 | unsigned long pfn; | |
155b7edb | 71 | struct list_head node; |
0a8704a5 RPM |
72 | }; |
73 | ||
9f27ee59 JF |
74 | struct blk_shadow { |
75 | struct blkif_request req; | |
a945b980 | 76 | struct request *request; |
402b27f9 RPM |
77 | struct grant **grants_used; |
78 | struct grant **indirect_grants; | |
b7649158 | 79 | struct scatterlist *sg; |
402b27f9 RPM |
80 | }; |
81 | ||
82 | struct split_bio { | |
83 | struct bio *bio; | |
84 | atomic_t pending; | |
85 | int err; | |
9f27ee59 JF |
86 | }; |
87 | ||
2a48fc0a | 88 | static DEFINE_MUTEX(blkfront_mutex); |
83d5cde4 | 89 | static const struct block_device_operations xlvbd_block_fops; |
9f27ee59 | 90 | |
402b27f9 RPM |
91 | /* |
92 | * Maximum number of segments in indirect requests, the actual value used by | |
93 | * the frontend driver is the minimum of this value and the value provided | |
94 | * by the backend driver. | |
95 | */ | |
96 | ||
97 | static unsigned int xen_blkif_max_segments = 32; | |
2d5dc3ba KRW |
98 | module_param_named(max, xen_blkif_max_segments, int, S_IRUGO); |
99 | MODULE_PARM_DESC(max, "Maximum amount of segments in indirect requests (default is 32)"); | |
402b27f9 | 100 | |
86839c56 BL |
101 | /* |
102 | * Maximum order of pages to be used for the shared ring between front and | |
103 | * backend, 4KB page granularity is used. | |
104 | */ | |
105 | static unsigned int xen_blkif_max_ring_order; | |
106 | module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, S_IRUGO); | |
107 | MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring"); | |
108 | ||
109 | #define BLK_RING_SIZE(info) __CONST_RING_SIZE(blkif, PAGE_SIZE * (info)->nr_ring_pages) | |
110 | #define BLK_MAX_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE * XENBUS_MAX_RING_PAGES) | |
111 | /* | |
112 | * ring-ref%i i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19 | |
113 | * characters are enough. Define to 20 to keep consist with backend. | |
114 | */ | |
115 | #define RINGREF_NAME_LEN (20) | |
9f27ee59 JF |
116 | |
117 | /* | |
118 | * We have one of these per vbd, whether ide, scsi or 'other'. They | |
119 | * hang in private_data off the gendisk structure. We may end up | |
120 | * putting all kinds of interesting stuff here :-) | |
121 | */ | |
122 | struct blkfront_info | |
123 | { | |
3467811e | 124 | spinlock_t io_lock; |
b70f5fa0 | 125 | struct mutex mutex; |
9f27ee59 | 126 | struct xenbus_device *xbdev; |
9f27ee59 JF |
127 | struct gendisk *gd; |
128 | int vdevice; | |
129 | blkif_vdev_t handle; | |
130 | enum blkif_state connected; | |
86839c56 BL |
131 | int ring_ref[XENBUS_MAX_RING_PAGES]; |
132 | unsigned int nr_ring_pages; | |
9f27ee59 JF |
133 | struct blkif_front_ring ring; |
134 | unsigned int evtchn, irq; | |
135 | struct request_queue *rq; | |
136 | struct work_struct work; | |
137 | struct gnttab_free_callback callback; | |
86839c56 | 138 | struct blk_shadow shadow[BLK_MAX_RING_SIZE]; |
bfe11d6d RPM |
139 | struct list_head grants; |
140 | struct list_head indirect_pages; | |
0a8704a5 | 141 | unsigned int persistent_gnts_c; |
9f27ee59 | 142 | unsigned long shadow_free; |
4913efe4 | 143 | unsigned int feature_flush; |
5ea42986 KRW |
144 | unsigned int feature_discard:1; |
145 | unsigned int feature_secdiscard:1; | |
ed30bf31 LD |
146 | unsigned int discard_granularity; |
147 | unsigned int discard_alignment; | |
0a8704a5 | 148 | unsigned int feature_persistent:1; |
402b27f9 | 149 | unsigned int max_indirect_segments; |
1d78d705 | 150 | int is_ready; |
9f27ee59 JF |
151 | }; |
152 | ||
0e345826 JB |
153 | static unsigned int nr_minors; |
154 | static unsigned long *minors; | |
155 | static DEFINE_SPINLOCK(minor_lock); | |
156 | ||
9f27ee59 JF |
157 | #define GRANT_INVALID_REF 0 |
158 | ||
159 | #define PARTS_PER_DISK 16 | |
9246b5f0 | 160 | #define PARTS_PER_EXT_DISK 256 |
9f27ee59 JF |
161 | |
162 | #define BLKIF_MAJOR(dev) ((dev)>>8) | |
163 | #define BLKIF_MINOR(dev) ((dev) & 0xff) | |
164 | ||
9246b5f0 CL |
165 | #define EXT_SHIFT 28 |
166 | #define EXTENDED (1<<EXT_SHIFT) | |
167 | #define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED)) | |
168 | #define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED)) | |
c80a4209 SS |
169 | #define EMULATED_HD_DISK_MINOR_OFFSET (0) |
170 | #define EMULATED_HD_DISK_NAME_OFFSET (EMULATED_HD_DISK_MINOR_OFFSET / 256) | |
196cfe2a SB |
171 | #define EMULATED_SD_DISK_MINOR_OFFSET (0) |
172 | #define EMULATED_SD_DISK_NAME_OFFSET (EMULATED_SD_DISK_MINOR_OFFSET / 256) | |
9f27ee59 | 173 | |
9246b5f0 | 174 | #define DEV_NAME "xvd" /* name in /dev */ |
9f27ee59 | 175 | |
402b27f9 | 176 | #define SEGS_PER_INDIRECT_FRAME \ |
80bfa2f6 | 177 | (PAGE_SIZE/sizeof(struct blkif_request_segment)) |
402b27f9 RPM |
178 | #define INDIRECT_GREFS(_segs) \ |
179 | ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME) | |
180 | ||
181 | static int blkfront_setup_indirect(struct blkfront_info *info); | |
182 | ||
9f27ee59 JF |
183 | static int get_id_from_freelist(struct blkfront_info *info) |
184 | { | |
185 | unsigned long free = info->shadow_free; | |
86839c56 | 186 | BUG_ON(free >= BLK_RING_SIZE(info)); |
97e36834 KRW |
187 | info->shadow_free = info->shadow[free].req.u.rw.id; |
188 | info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */ | |
9f27ee59 JF |
189 | return free; |
190 | } | |
191 | ||
6878c32e | 192 | static int add_id_to_freelist(struct blkfront_info *info, |
9f27ee59 JF |
193 | unsigned long id) |
194 | { | |
6878c32e KRW |
195 | if (info->shadow[id].req.u.rw.id != id) |
196 | return -EINVAL; | |
197 | if (info->shadow[id].request == NULL) | |
198 | return -EINVAL; | |
97e36834 | 199 | info->shadow[id].req.u.rw.id = info->shadow_free; |
a945b980 | 200 | info->shadow[id].request = NULL; |
9f27ee59 | 201 | info->shadow_free = id; |
6878c32e | 202 | return 0; |
9f27ee59 JF |
203 | } |
204 | ||
9c1e050c RPM |
205 | static int fill_grant_buffer(struct blkfront_info *info, int num) |
206 | { | |
207 | struct page *granted_page; | |
208 | struct grant *gnt_list_entry, *n; | |
209 | int i = 0; | |
210 | ||
211 | while(i < num) { | |
212 | gnt_list_entry = kzalloc(sizeof(struct grant), GFP_NOIO); | |
213 | if (!gnt_list_entry) | |
214 | goto out_of_memory; | |
215 | ||
bfe11d6d RPM |
216 | if (info->feature_persistent) { |
217 | granted_page = alloc_page(GFP_NOIO); | |
218 | if (!granted_page) { | |
219 | kfree(gnt_list_entry); | |
220 | goto out_of_memory; | |
221 | } | |
222 | gnt_list_entry->pfn = page_to_pfn(granted_page); | |
9c1e050c RPM |
223 | } |
224 | ||
9c1e050c | 225 | gnt_list_entry->gref = GRANT_INVALID_REF; |
bfe11d6d | 226 | list_add(&gnt_list_entry->node, &info->grants); |
9c1e050c RPM |
227 | i++; |
228 | } | |
229 | ||
230 | return 0; | |
231 | ||
232 | out_of_memory: | |
233 | list_for_each_entry_safe(gnt_list_entry, n, | |
bfe11d6d | 234 | &info->grants, node) { |
9c1e050c | 235 | list_del(&gnt_list_entry->node); |
bfe11d6d RPM |
236 | if (info->feature_persistent) |
237 | __free_page(pfn_to_page(gnt_list_entry->pfn)); | |
9c1e050c RPM |
238 | kfree(gnt_list_entry); |
239 | i--; | |
240 | } | |
241 | BUG_ON(i != 0); | |
242 | return -ENOMEM; | |
243 | } | |
244 | ||
245 | static struct grant *get_grant(grant_ref_t *gref_head, | |
bfe11d6d | 246 | unsigned long pfn, |
9c1e050c RPM |
247 | struct blkfront_info *info) |
248 | { | |
249 | struct grant *gnt_list_entry; | |
250 | unsigned long buffer_mfn; | |
251 | ||
bfe11d6d RPM |
252 | BUG_ON(list_empty(&info->grants)); |
253 | gnt_list_entry = list_first_entry(&info->grants, struct grant, | |
9c1e050c RPM |
254 | node); |
255 | list_del(&gnt_list_entry->node); | |
256 | ||
257 | if (gnt_list_entry->gref != GRANT_INVALID_REF) { | |
258 | info->persistent_gnts_c--; | |
259 | return gnt_list_entry; | |
260 | } | |
261 | ||
262 | /* Assign a gref to this page */ | |
263 | gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); | |
264 | BUG_ON(gnt_list_entry->gref == -ENOSPC); | |
bfe11d6d RPM |
265 | if (!info->feature_persistent) { |
266 | BUG_ON(!pfn); | |
267 | gnt_list_entry->pfn = pfn; | |
268 | } | |
9c1e050c RPM |
269 | buffer_mfn = pfn_to_mfn(gnt_list_entry->pfn); |
270 | gnttab_grant_foreign_access_ref(gnt_list_entry->gref, | |
271 | info->xbdev->otherend_id, | |
272 | buffer_mfn, 0); | |
273 | return gnt_list_entry; | |
274 | } | |
275 | ||
6878c32e KRW |
276 | static const char *op_name(int op) |
277 | { | |
278 | static const char *const names[] = { | |
279 | [BLKIF_OP_READ] = "read", | |
280 | [BLKIF_OP_WRITE] = "write", | |
281 | [BLKIF_OP_WRITE_BARRIER] = "barrier", | |
282 | [BLKIF_OP_FLUSH_DISKCACHE] = "flush", | |
283 | [BLKIF_OP_DISCARD] = "discard" }; | |
284 | ||
285 | if (op < 0 || op >= ARRAY_SIZE(names)) | |
286 | return "unknown"; | |
287 | ||
288 | if (!names[op]) | |
289 | return "reserved"; | |
290 | ||
291 | return names[op]; | |
292 | } | |
0e345826 JB |
293 | static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) |
294 | { | |
295 | unsigned int end = minor + nr; | |
296 | int rc; | |
297 | ||
298 | if (end > nr_minors) { | |
299 | unsigned long *bitmap, *old; | |
300 | ||
f094148a | 301 | bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap), |
0e345826 JB |
302 | GFP_KERNEL); |
303 | if (bitmap == NULL) | |
304 | return -ENOMEM; | |
305 | ||
306 | spin_lock(&minor_lock); | |
307 | if (end > nr_minors) { | |
308 | old = minors; | |
309 | memcpy(bitmap, minors, | |
310 | BITS_TO_LONGS(nr_minors) * sizeof(*bitmap)); | |
311 | minors = bitmap; | |
312 | nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG; | |
313 | } else | |
314 | old = bitmap; | |
315 | spin_unlock(&minor_lock); | |
316 | kfree(old); | |
317 | } | |
318 | ||
319 | spin_lock(&minor_lock); | |
320 | if (find_next_bit(minors, end, minor) >= end) { | |
34ae2e47 | 321 | bitmap_set(minors, minor, nr); |
0e345826 JB |
322 | rc = 0; |
323 | } else | |
324 | rc = -EBUSY; | |
325 | spin_unlock(&minor_lock); | |
326 | ||
327 | return rc; | |
328 | } | |
329 | ||
330 | static void xlbd_release_minors(unsigned int minor, unsigned int nr) | |
331 | { | |
332 | unsigned int end = minor + nr; | |
333 | ||
334 | BUG_ON(end > nr_minors); | |
335 | spin_lock(&minor_lock); | |
34ae2e47 | 336 | bitmap_clear(minors, minor, nr); |
0e345826 JB |
337 | spin_unlock(&minor_lock); |
338 | } | |
339 | ||
9f27ee59 JF |
340 | static void blkif_restart_queue_callback(void *arg) |
341 | { | |
342 | struct blkfront_info *info = (struct blkfront_info *)arg; | |
343 | schedule_work(&info->work); | |
344 | } | |
345 | ||
afe42d7d | 346 | static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg) |
597592d9 IC |
347 | { |
348 | /* We don't have real geometry info, but let's at least return | |
349 | values consistent with the size of the device */ | |
350 | sector_t nsect = get_capacity(bd->bd_disk); | |
351 | sector_t cylinders = nsect; | |
352 | ||
353 | hg->heads = 0xff; | |
354 | hg->sectors = 0x3f; | |
355 | sector_div(cylinders, hg->heads * hg->sectors); | |
356 | hg->cylinders = cylinders; | |
357 | if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect) | |
358 | hg->cylinders = 0xffff; | |
359 | return 0; | |
360 | } | |
361 | ||
a63c848b | 362 | static int blkif_ioctl(struct block_device *bdev, fmode_t mode, |
62aa0054 | 363 | unsigned command, unsigned long argument) |
440a01a7 | 364 | { |
a63c848b | 365 | struct blkfront_info *info = bdev->bd_disk->private_data; |
440a01a7 CL |
366 | int i; |
367 | ||
368 | dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n", | |
369 | command, (long)argument); | |
370 | ||
371 | switch (command) { | |
372 | case CDROMMULTISESSION: | |
373 | dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n"); | |
374 | for (i = 0; i < sizeof(struct cdrom_multisession); i++) | |
375 | if (put_user(0, (char __user *)(argument + i))) | |
376 | return -EFAULT; | |
377 | return 0; | |
378 | ||
379 | case CDROM_GET_CAPABILITY: { | |
380 | struct gendisk *gd = info->gd; | |
381 | if (gd->flags & GENHD_FL_CD) | |
382 | return 0; | |
383 | return -EINVAL; | |
384 | } | |
385 | ||
386 | default: | |
387 | /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n", | |
388 | command);*/ | |
389 | return -EINVAL; /* same return as native Linux */ | |
390 | } | |
391 | ||
392 | return 0; | |
393 | } | |
394 | ||
9f27ee59 | 395 | /* |
c64e38ea | 396 | * Generate a Xen blkfront IO request from a blk layer request. Reads |
edf6ef59 | 397 | * and writes are handled as expected. |
9f27ee59 | 398 | * |
c64e38ea | 399 | * @req: a request struct |
9f27ee59 JF |
400 | */ |
401 | static int blkif_queue_request(struct request *req) | |
402 | { | |
403 | struct blkfront_info *info = req->rq_disk->private_data; | |
9f27ee59 | 404 | struct blkif_request *ring_req; |
9f27ee59 JF |
405 | unsigned long id; |
406 | unsigned int fsect, lsect; | |
402b27f9 | 407 | int i, ref, n; |
80bfa2f6 | 408 | struct blkif_request_segment *segments = NULL; |
0a8704a5 RPM |
409 | |
410 | /* | |
411 | * Used to store if we are able to queue the request by just using | |
412 | * existing persistent grants, or if we have to get new grants, | |
413 | * as there are not sufficiently many free. | |
414 | */ | |
415 | bool new_persistent_gnts; | |
9f27ee59 | 416 | grant_ref_t gref_head; |
0a8704a5 | 417 | struct grant *gnt_list_entry = NULL; |
9e973e64 | 418 | struct scatterlist *sg; |
402b27f9 | 419 | int nseg, max_grefs; |
9f27ee59 JF |
420 | |
421 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) | |
422 | return 1; | |
423 | ||
c47206e2 RPM |
424 | max_grefs = req->nr_phys_segments; |
425 | if (max_grefs > BLKIF_MAX_SEGMENTS_PER_REQUEST) | |
426 | /* | |
427 | * If we are using indirect segments we need to account | |
428 | * for the indirect grefs used in the request. | |
429 | */ | |
430 | max_grefs += INDIRECT_GREFS(req->nr_phys_segments); | |
402b27f9 RPM |
431 | |
432 | /* Check if we have enough grants to allocate a requests */ | |
433 | if (info->persistent_gnts_c < max_grefs) { | |
0a8704a5 RPM |
434 | new_persistent_gnts = 1; |
435 | if (gnttab_alloc_grant_references( | |
402b27f9 | 436 | max_grefs - info->persistent_gnts_c, |
0a8704a5 RPM |
437 | &gref_head) < 0) { |
438 | gnttab_request_free_callback( | |
439 | &info->callback, | |
440 | blkif_restart_queue_callback, | |
441 | info, | |
402b27f9 | 442 | max_grefs); |
0a8704a5 RPM |
443 | return 1; |
444 | } | |
445 | } else | |
446 | new_persistent_gnts = 0; | |
9f27ee59 JF |
447 | |
448 | /* Fill out a communications ring structure. */ | |
449 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
450 | id = get_id_from_freelist(info); | |
a945b980 | 451 | info->shadow[id].request = req; |
9f27ee59 | 452 | |
5ea42986 | 453 | if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE))) { |
ed30bf31 | 454 | ring_req->operation = BLKIF_OP_DISCARD; |
ed30bf31 | 455 | ring_req->u.discard.nr_sectors = blk_rq_sectors(req); |
402b27f9 RPM |
456 | ring_req->u.discard.id = id; |
457 | ring_req->u.discard.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
5ea42986 KRW |
458 | if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard) |
459 | ring_req->u.discard.flag = BLKIF_DISCARD_SECURE; | |
460 | else | |
461 | ring_req->u.discard.flag = 0; | |
ed30bf31 | 462 | } else { |
402b27f9 RPM |
463 | BUG_ON(info->max_indirect_segments == 0 && |
464 | req->nr_phys_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
465 | BUG_ON(info->max_indirect_segments && | |
466 | req->nr_phys_segments > info->max_indirect_segments); | |
b7649158 | 467 | nseg = blk_rq_map_sg(req->q, req, info->shadow[id].sg); |
402b27f9 RPM |
468 | ring_req->u.rw.id = id; |
469 | if (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST) { | |
470 | /* | |
471 | * The indirect operation can only be a BLKIF_OP_READ or | |
472 | * BLKIF_OP_WRITE | |
473 | */ | |
474 | BUG_ON(req->cmd_flags & (REQ_FLUSH | REQ_FUA)); | |
475 | ring_req->operation = BLKIF_OP_INDIRECT; | |
476 | ring_req->u.indirect.indirect_op = rq_data_dir(req) ? | |
477 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
478 | ring_req->u.indirect.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
479 | ring_req->u.indirect.handle = info->handle; | |
480 | ring_req->u.indirect.nr_segments = nseg; | |
481 | } else { | |
482 | ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
483 | ring_req->u.rw.handle = info->handle; | |
484 | ring_req->operation = rq_data_dir(req) ? | |
485 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
486 | if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) { | |
487 | /* | |
488 | * Ideally we can do an unordered flush-to-disk. In case the | |
489 | * backend onlysupports barriers, use that. A barrier request | |
490 | * a superset of FUA, so we can implement it the same | |
491 | * way. (It's also a FLUSH+FUA, since it is | |
492 | * guaranteed ordered WRT previous writes.) | |
493 | */ | |
fdf9b965 VK |
494 | switch (info->feature_flush & |
495 | ((REQ_FLUSH|REQ_FUA))) { | |
496 | case REQ_FLUSH|REQ_FUA: | |
497 | ring_req->operation = | |
498 | BLKIF_OP_WRITE_BARRIER; | |
499 | break; | |
500 | case REQ_FLUSH: | |
501 | ring_req->operation = | |
502 | BLKIF_OP_FLUSH_DISKCACHE; | |
503 | break; | |
504 | default: | |
505 | ring_req->operation = 0; | |
506 | } | |
402b27f9 RPM |
507 | } |
508 | ring_req->u.rw.nr_segments = nseg; | |
509 | } | |
b7649158 | 510 | for_each_sg(info->shadow[id].sg, sg, nseg, i) { |
ed30bf31 LD |
511 | fsect = sg->offset >> 9; |
512 | lsect = fsect + (sg->length >> 9) - 1; | |
6c92e699 | 513 | |
402b27f9 RPM |
514 | if ((ring_req->operation == BLKIF_OP_INDIRECT) && |
515 | (i % SEGS_PER_INDIRECT_FRAME == 0)) { | |
427bfe07 | 516 | unsigned long uninitialized_var(pfn); |
bfe11d6d | 517 | |
402b27f9 RPM |
518 | if (segments) |
519 | kunmap_atomic(segments); | |
520 | ||
521 | n = i / SEGS_PER_INDIRECT_FRAME; | |
bfe11d6d RPM |
522 | if (!info->feature_persistent) { |
523 | struct page *indirect_page; | |
524 | ||
525 | /* Fetch a pre-allocated page to use for indirect grefs */ | |
526 | BUG_ON(list_empty(&info->indirect_pages)); | |
527 | indirect_page = list_first_entry(&info->indirect_pages, | |
528 | struct page, lru); | |
529 | list_del(&indirect_page->lru); | |
530 | pfn = page_to_pfn(indirect_page); | |
531 | } | |
532 | gnt_list_entry = get_grant(&gref_head, pfn, info); | |
402b27f9 RPM |
533 | info->shadow[id].indirect_grants[n] = gnt_list_entry; |
534 | segments = kmap_atomic(pfn_to_page(gnt_list_entry->pfn)); | |
535 | ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref; | |
536 | } | |
537 | ||
bfe11d6d | 538 | gnt_list_entry = get_grant(&gref_head, page_to_pfn(sg_page(sg)), info); |
9c1e050c | 539 | ref = gnt_list_entry->gref; |
0a8704a5 RPM |
540 | |
541 | info->shadow[id].grants_used[i] = gnt_list_entry; | |
542 | ||
bfe11d6d | 543 | if (rq_data_dir(req) && info->feature_persistent) { |
0a8704a5 RPM |
544 | char *bvec_data; |
545 | void *shared_data; | |
546 | ||
547 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); | |
548 | ||
402b27f9 | 549 | shared_data = kmap_atomic(pfn_to_page(gnt_list_entry->pfn)); |
0a8704a5 RPM |
550 | bvec_data = kmap_atomic(sg_page(sg)); |
551 | ||
552 | /* | |
553 | * this does not wipe data stored outside the | |
554 | * range sg->offset..sg->offset+sg->length. | |
555 | * Therefore, blkback *could* see data from | |
556 | * previous requests. This is OK as long as | |
557 | * persistent grants are shared with just one | |
558 | * domain. It may need refactoring if this | |
559 | * changes | |
560 | */ | |
561 | memcpy(shared_data + sg->offset, | |
562 | bvec_data + sg->offset, | |
563 | sg->length); | |
564 | ||
565 | kunmap_atomic(bvec_data); | |
566 | kunmap_atomic(shared_data); | |
567 | } | |
402b27f9 RPM |
568 | if (ring_req->operation != BLKIF_OP_INDIRECT) { |
569 | ring_req->u.rw.seg[i] = | |
570 | (struct blkif_request_segment) { | |
571 | .gref = ref, | |
572 | .first_sect = fsect, | |
573 | .last_sect = lsect }; | |
574 | } else { | |
575 | n = i % SEGS_PER_INDIRECT_FRAME; | |
576 | segments[n] = | |
80bfa2f6 | 577 | (struct blkif_request_segment) { |
402b27f9 RPM |
578 | .gref = ref, |
579 | .first_sect = fsect, | |
580 | .last_sect = lsect }; | |
581 | } | |
ed30bf31 | 582 | } |
402b27f9 RPM |
583 | if (segments) |
584 | kunmap_atomic(segments); | |
9f27ee59 JF |
585 | } |
586 | ||
587 | info->ring.req_prod_pvt++; | |
588 | ||
589 | /* Keep a private copy so we can reissue requests when recovering. */ | |
590 | info->shadow[id].req = *ring_req; | |
591 | ||
0a8704a5 RPM |
592 | if (new_persistent_gnts) |
593 | gnttab_free_grant_references(gref_head); | |
9f27ee59 JF |
594 | |
595 | return 0; | |
596 | } | |
597 | ||
598 | ||
599 | static inline void flush_requests(struct blkfront_info *info) | |
600 | { | |
601 | int notify; | |
602 | ||
603 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify); | |
604 | ||
605 | if (notify) | |
606 | notify_remote_via_irq(info->irq); | |
607 | } | |
608 | ||
ad42d391 VK |
609 | static inline bool blkif_request_flush_invalid(struct request *req, |
610 | struct blkfront_info *info) | |
0f1ca65e AA |
611 | { |
612 | return ((req->cmd_type != REQ_TYPE_FS) || | |
ad42d391 VK |
613 | ((req->cmd_flags & REQ_FLUSH) && |
614 | !(info->feature_flush & REQ_FLUSH)) || | |
615 | ((req->cmd_flags & REQ_FUA) && | |
616 | !(info->feature_flush & REQ_FUA))); | |
0f1ca65e AA |
617 | } |
618 | ||
9f27ee59 JF |
619 | /* |
620 | * do_blkif_request | |
621 | * read a block; request is in a request queue | |
622 | */ | |
165125e1 | 623 | static void do_blkif_request(struct request_queue *rq) |
9f27ee59 JF |
624 | { |
625 | struct blkfront_info *info = NULL; | |
626 | struct request *req; | |
627 | int queued; | |
628 | ||
629 | pr_debug("Entered do_blkif_request\n"); | |
630 | ||
631 | queued = 0; | |
632 | ||
9934c8c0 | 633 | while ((req = blk_peek_request(rq)) != NULL) { |
9f27ee59 | 634 | info = req->rq_disk->private_data; |
9f27ee59 JF |
635 | |
636 | if (RING_FULL(&info->ring)) | |
637 | goto wait; | |
638 | ||
9934c8c0 | 639 | blk_start_request(req); |
296b2f6a | 640 | |
ad42d391 VK |
641 | if (blkif_request_flush_invalid(req, info)) { |
642 | __blk_end_request_all(req, -EOPNOTSUPP); | |
296b2f6a TH |
643 | continue; |
644 | } | |
645 | ||
9f27ee59 | 646 | pr_debug("do_blk_req %p: cmd %p, sec %lx, " |
b4f42e28 | 647 | "(%u/%u) [%s]\n", |
83096ebf TH |
648 | req, req->cmd, (unsigned long)blk_rq_pos(req), |
649 | blk_rq_cur_sectors(req), blk_rq_sectors(req), | |
b4f42e28 | 650 | rq_data_dir(req) ? "write" : "read"); |
9f27ee59 | 651 | |
9f27ee59 JF |
652 | if (blkif_queue_request(req)) { |
653 | blk_requeue_request(rq, req); | |
654 | wait: | |
655 | /* Avoid pointless unplugs. */ | |
656 | blk_stop_queue(rq); | |
657 | break; | |
658 | } | |
659 | ||
660 | queued++; | |
661 | } | |
662 | ||
663 | if (queued != 0) | |
664 | flush_requests(info); | |
665 | } | |
666 | ||
402b27f9 | 667 | static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, |
7c4d7d71 | 668 | unsigned int physical_sector_size, |
402b27f9 | 669 | unsigned int segments) |
9f27ee59 | 670 | { |
165125e1 | 671 | struct request_queue *rq; |
ed30bf31 | 672 | struct blkfront_info *info = gd->private_data; |
9f27ee59 | 673 | |
3467811e | 674 | rq = blk_init_queue(do_blkif_request, &info->io_lock); |
9f27ee59 JF |
675 | if (rq == NULL) |
676 | return -1; | |
677 | ||
66d352e1 | 678 | queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); |
9f27ee59 | 679 | |
ed30bf31 LD |
680 | if (info->feature_discard) { |
681 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, rq); | |
682 | blk_queue_max_discard_sectors(rq, get_capacity(gd)); | |
683 | rq->limits.discard_granularity = info->discard_granularity; | |
684 | rq->limits.discard_alignment = info->discard_alignment; | |
5ea42986 KRW |
685 | if (info->feature_secdiscard) |
686 | queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, rq); | |
ed30bf31 LD |
687 | } |
688 | ||
9f27ee59 | 689 | /* Hard sector size and max sectors impersonate the equiv. hardware. */ |
e1defc4f | 690 | blk_queue_logical_block_size(rq, sector_size); |
7c4d7d71 | 691 | blk_queue_physical_block_size(rq, physical_sector_size); |
294caaf2 | 692 | blk_queue_max_hw_sectors(rq, (segments * PAGE_SIZE) / 512); |
9f27ee59 JF |
693 | |
694 | /* Each segment in a request is up to an aligned page in size. */ | |
695 | blk_queue_segment_boundary(rq, PAGE_SIZE - 1); | |
696 | blk_queue_max_segment_size(rq, PAGE_SIZE); | |
697 | ||
698 | /* Ensure a merged request will fit in a single I/O ring slot. */ | |
402b27f9 | 699 | blk_queue_max_segments(rq, segments); |
9f27ee59 JF |
700 | |
701 | /* Make sure buffer addresses are sector-aligned. */ | |
702 | blk_queue_dma_alignment(rq, 511); | |
703 | ||
1c91fe1a IC |
704 | /* Make sure we don't use bounce buffers. */ |
705 | blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY); | |
706 | ||
9f27ee59 JF |
707 | gd->queue = rq; |
708 | ||
709 | return 0; | |
710 | } | |
711 | ||
fdf9b965 VK |
712 | static const char *flush_info(unsigned int feature_flush) |
713 | { | |
714 | switch (feature_flush & ((REQ_FLUSH | REQ_FUA))) { | |
715 | case REQ_FLUSH|REQ_FUA: | |
716 | return "barrier: enabled;"; | |
717 | case REQ_FLUSH: | |
718 | return "flush diskcache: enabled;"; | |
719 | default: | |
720 | return "barrier or flush: disabled;"; | |
721 | } | |
722 | } | |
9f27ee59 | 723 | |
4913efe4 | 724 | static void xlvbd_flush(struct blkfront_info *info) |
9f27ee59 | 725 | { |
4913efe4 | 726 | blk_queue_flush(info->rq, info->feature_flush); |
fdf9b965 VK |
727 | pr_info("blkfront: %s: %s %s %s %s %s\n", |
728 | info->gd->disk_name, flush_info(info->feature_flush), | |
729 | "persistent grants:", info->feature_persistent ? | |
730 | "enabled;" : "disabled;", "indirect descriptors:", | |
731 | info->max_indirect_segments ? "enabled;" : "disabled;"); | |
9f27ee59 JF |
732 | } |
733 | ||
c80a4209 SS |
734 | static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) |
735 | { | |
736 | int major; | |
737 | major = BLKIF_MAJOR(vdevice); | |
738 | *minor = BLKIF_MINOR(vdevice); | |
739 | switch (major) { | |
740 | case XEN_IDE0_MAJOR: | |
741 | *offset = (*minor / 64) + EMULATED_HD_DISK_NAME_OFFSET; | |
742 | *minor = ((*minor / 64) * PARTS_PER_DISK) + | |
743 | EMULATED_HD_DISK_MINOR_OFFSET; | |
744 | break; | |
745 | case XEN_IDE1_MAJOR: | |
746 | *offset = (*minor / 64) + 2 + EMULATED_HD_DISK_NAME_OFFSET; | |
747 | *minor = (((*minor / 64) + 2) * PARTS_PER_DISK) + | |
748 | EMULATED_HD_DISK_MINOR_OFFSET; | |
749 | break; | |
750 | case XEN_SCSI_DISK0_MAJOR: | |
751 | *offset = (*minor / PARTS_PER_DISK) + EMULATED_SD_DISK_NAME_OFFSET; | |
752 | *minor = *minor + EMULATED_SD_DISK_MINOR_OFFSET; | |
753 | break; | |
754 | case XEN_SCSI_DISK1_MAJOR: | |
755 | case XEN_SCSI_DISK2_MAJOR: | |
756 | case XEN_SCSI_DISK3_MAJOR: | |
757 | case XEN_SCSI_DISK4_MAJOR: | |
758 | case XEN_SCSI_DISK5_MAJOR: | |
759 | case XEN_SCSI_DISK6_MAJOR: | |
760 | case XEN_SCSI_DISK7_MAJOR: | |
761 | *offset = (*minor / PARTS_PER_DISK) + | |
762 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16) + | |
763 | EMULATED_SD_DISK_NAME_OFFSET; | |
764 | *minor = *minor + | |
765 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16 * PARTS_PER_DISK) + | |
766 | EMULATED_SD_DISK_MINOR_OFFSET; | |
767 | break; | |
768 | case XEN_SCSI_DISK8_MAJOR: | |
769 | case XEN_SCSI_DISK9_MAJOR: | |
770 | case XEN_SCSI_DISK10_MAJOR: | |
771 | case XEN_SCSI_DISK11_MAJOR: | |
772 | case XEN_SCSI_DISK12_MAJOR: | |
773 | case XEN_SCSI_DISK13_MAJOR: | |
774 | case XEN_SCSI_DISK14_MAJOR: | |
775 | case XEN_SCSI_DISK15_MAJOR: | |
776 | *offset = (*minor / PARTS_PER_DISK) + | |
777 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16) + | |
778 | EMULATED_SD_DISK_NAME_OFFSET; | |
779 | *minor = *minor + | |
780 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16 * PARTS_PER_DISK) + | |
781 | EMULATED_SD_DISK_MINOR_OFFSET; | |
782 | break; | |
783 | case XENVBD_MAJOR: | |
784 | *offset = *minor / PARTS_PER_DISK; | |
785 | break; | |
786 | default: | |
787 | printk(KERN_WARNING "blkfront: your disk configuration is " | |
788 | "incorrect, please use an xvd device instead\n"); | |
789 | return -ENODEV; | |
790 | } | |
791 | return 0; | |
792 | } | |
9f27ee59 | 793 | |
e77c78c0 JB |
794 | static char *encode_disk_name(char *ptr, unsigned int n) |
795 | { | |
796 | if (n >= 26) | |
797 | ptr = encode_disk_name(ptr, n / 26 - 1); | |
798 | *ptr = 'a' + n % 26; | |
799 | return ptr + 1; | |
800 | } | |
801 | ||
9246b5f0 CL |
802 | static int xlvbd_alloc_gendisk(blkif_sector_t capacity, |
803 | struct blkfront_info *info, | |
7c4d7d71 SB |
804 | u16 vdisk_info, u16 sector_size, |
805 | unsigned int physical_sector_size) | |
9f27ee59 JF |
806 | { |
807 | struct gendisk *gd; | |
808 | int nr_minors = 1; | |
c80a4209 | 809 | int err; |
9246b5f0 CL |
810 | unsigned int offset; |
811 | int minor; | |
812 | int nr_parts; | |
e77c78c0 | 813 | char *ptr; |
9f27ee59 JF |
814 | |
815 | BUG_ON(info->gd != NULL); | |
816 | BUG_ON(info->rq != NULL); | |
817 | ||
9246b5f0 CL |
818 | if ((info->vdevice>>EXT_SHIFT) > 1) { |
819 | /* this is above the extended range; something is wrong */ | |
820 | printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice); | |
821 | return -ENODEV; | |
822 | } | |
823 | ||
824 | if (!VDEV_IS_EXTENDED(info->vdevice)) { | |
c80a4209 SS |
825 | err = xen_translate_vdev(info->vdevice, &minor, &offset); |
826 | if (err) | |
827 | return err; | |
828 | nr_parts = PARTS_PER_DISK; | |
9246b5f0 CL |
829 | } else { |
830 | minor = BLKIF_MINOR_EXT(info->vdevice); | |
831 | nr_parts = PARTS_PER_EXT_DISK; | |
c80a4209 | 832 | offset = minor / nr_parts; |
89153b5c | 833 | if (xen_hvm_domain() && offset < EMULATED_HD_DISK_NAME_OFFSET + 4) |
c80a4209 SS |
834 | printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with " |
835 | "emulated IDE disks,\n\t choose an xvd device name" | |
836 | "from xvde on\n", info->vdevice); | |
9246b5f0 | 837 | } |
e77c78c0 JB |
838 | if (minor >> MINORBITS) { |
839 | pr_warn("blkfront: %#x's minor (%#x) out of range; ignoring\n", | |
840 | info->vdevice, minor); | |
841 | return -ENODEV; | |
842 | } | |
9246b5f0 CL |
843 | |
844 | if ((minor % nr_parts) == 0) | |
845 | nr_minors = nr_parts; | |
9f27ee59 | 846 | |
0e345826 JB |
847 | err = xlbd_reserve_minors(minor, nr_minors); |
848 | if (err) | |
849 | goto out; | |
850 | err = -ENODEV; | |
851 | ||
9f27ee59 JF |
852 | gd = alloc_disk(nr_minors); |
853 | if (gd == NULL) | |
0e345826 | 854 | goto release; |
9f27ee59 | 855 | |
e77c78c0 JB |
856 | strcpy(gd->disk_name, DEV_NAME); |
857 | ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset); | |
858 | BUG_ON(ptr >= gd->disk_name + DISK_NAME_LEN); | |
859 | if (nr_minors > 1) | |
860 | *ptr = 0; | |
861 | else | |
862 | snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr, | |
863 | "%d", minor & (nr_parts - 1)); | |
9f27ee59 JF |
864 | |
865 | gd->major = XENVBD_MAJOR; | |
866 | gd->first_minor = minor; | |
867 | gd->fops = &xlvbd_block_fops; | |
868 | gd->private_data = info; | |
869 | gd->driverfs_dev = &(info->xbdev->dev); | |
870 | set_capacity(gd, capacity); | |
871 | ||
7c4d7d71 | 872 | if (xlvbd_init_blk_queue(gd, sector_size, physical_sector_size, |
402b27f9 RPM |
873 | info->max_indirect_segments ? : |
874 | BLKIF_MAX_SEGMENTS_PER_REQUEST)) { | |
9f27ee59 | 875 | del_gendisk(gd); |
0e345826 | 876 | goto release; |
9f27ee59 JF |
877 | } |
878 | ||
879 | info->rq = gd->queue; | |
880 | info->gd = gd; | |
881 | ||
4913efe4 | 882 | xlvbd_flush(info); |
9f27ee59 JF |
883 | |
884 | if (vdisk_info & VDISK_READONLY) | |
885 | set_disk_ro(gd, 1); | |
886 | ||
887 | if (vdisk_info & VDISK_REMOVABLE) | |
888 | gd->flags |= GENHD_FL_REMOVABLE; | |
889 | ||
890 | if (vdisk_info & VDISK_CDROM) | |
891 | gd->flags |= GENHD_FL_CD; | |
892 | ||
893 | return 0; | |
894 | ||
0e345826 JB |
895 | release: |
896 | xlbd_release_minors(minor, nr_minors); | |
9f27ee59 JF |
897 | out: |
898 | return err; | |
899 | } | |
900 | ||
a66b5aeb DS |
901 | static void xlvbd_release_gendisk(struct blkfront_info *info) |
902 | { | |
903 | unsigned int minor, nr_minors; | |
904 | unsigned long flags; | |
905 | ||
906 | if (info->rq == NULL) | |
907 | return; | |
908 | ||
3467811e | 909 | spin_lock_irqsave(&info->io_lock, flags); |
a66b5aeb DS |
910 | |
911 | /* No more blkif_request(). */ | |
912 | blk_stop_queue(info->rq); | |
913 | ||
914 | /* No more gnttab callback work. */ | |
915 | gnttab_cancel_free_callback(&info->callback); | |
3467811e | 916 | spin_unlock_irqrestore(&info->io_lock, flags); |
a66b5aeb DS |
917 | |
918 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 919 | flush_work(&info->work); |
a66b5aeb DS |
920 | |
921 | del_gendisk(info->gd); | |
922 | ||
923 | minor = info->gd->first_minor; | |
924 | nr_minors = info->gd->minors; | |
925 | xlbd_release_minors(minor, nr_minors); | |
926 | ||
927 | blk_cleanup_queue(info->rq); | |
928 | info->rq = NULL; | |
929 | ||
930 | put_disk(info->gd); | |
931 | info->gd = NULL; | |
932 | } | |
933 | ||
9f27ee59 JF |
934 | static void kick_pending_request_queues(struct blkfront_info *info) |
935 | { | |
936 | if (!RING_FULL(&info->ring)) { | |
937 | /* Re-enable calldowns. */ | |
938 | blk_start_queue(info->rq); | |
939 | /* Kick things off immediately. */ | |
940 | do_blkif_request(info->rq); | |
941 | } | |
942 | } | |
943 | ||
944 | static void blkif_restart_queue(struct work_struct *work) | |
945 | { | |
946 | struct blkfront_info *info = container_of(work, struct blkfront_info, work); | |
947 | ||
3467811e | 948 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
949 | if (info->connected == BLKIF_STATE_CONNECTED) |
950 | kick_pending_request_queues(info); | |
3467811e | 951 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
952 | } |
953 | ||
954 | static void blkif_free(struct blkfront_info *info, int suspend) | |
955 | { | |
155b7edb RPM |
956 | struct grant *persistent_gnt; |
957 | struct grant *n; | |
402b27f9 | 958 | int i, j, segs; |
0a8704a5 | 959 | |
9f27ee59 | 960 | /* Prevent new requests being issued until we fix things up. */ |
3467811e | 961 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
962 | info->connected = suspend ? |
963 | BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; | |
964 | /* No more blkif_request(). */ | |
965 | if (info->rq) | |
966 | blk_stop_queue(info->rq); | |
0a8704a5 RPM |
967 | |
968 | /* Remove all persistent grants */ | |
bfe11d6d | 969 | if (!list_empty(&info->grants)) { |
155b7edb | 970 | list_for_each_entry_safe(persistent_gnt, n, |
bfe11d6d | 971 | &info->grants, node) { |
155b7edb | 972 | list_del(&persistent_gnt->node); |
9c1e050c RPM |
973 | if (persistent_gnt->gref != GRANT_INVALID_REF) { |
974 | gnttab_end_foreign_access(persistent_gnt->gref, | |
975 | 0, 0UL); | |
976 | info->persistent_gnts_c--; | |
977 | } | |
bfe11d6d RPM |
978 | if (info->feature_persistent) |
979 | __free_page(pfn_to_page(persistent_gnt->pfn)); | |
155b7edb | 980 | kfree(persistent_gnt); |
0a8704a5 | 981 | } |
0a8704a5 | 982 | } |
9c1e050c | 983 | BUG_ON(info->persistent_gnts_c != 0); |
0a8704a5 | 984 | |
bfe11d6d RPM |
985 | /* |
986 | * Remove indirect pages, this only happens when using indirect | |
987 | * descriptors but not persistent grants | |
988 | */ | |
989 | if (!list_empty(&info->indirect_pages)) { | |
990 | struct page *indirect_page, *n; | |
991 | ||
992 | BUG_ON(info->feature_persistent); | |
993 | list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) { | |
994 | list_del(&indirect_page->lru); | |
995 | __free_page(indirect_page); | |
996 | } | |
997 | } | |
998 | ||
86839c56 | 999 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1000 | /* |
1001 | * Clear persistent grants present in requests already | |
1002 | * on the shared ring | |
1003 | */ | |
1004 | if (!info->shadow[i].request) | |
1005 | goto free_shadow; | |
1006 | ||
1007 | segs = info->shadow[i].req.operation == BLKIF_OP_INDIRECT ? | |
1008 | info->shadow[i].req.u.indirect.nr_segments : | |
1009 | info->shadow[i].req.u.rw.nr_segments; | |
1010 | for (j = 0; j < segs; j++) { | |
1011 | persistent_gnt = info->shadow[i].grants_used[j]; | |
1012 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); | |
bfe11d6d RPM |
1013 | if (info->feature_persistent) |
1014 | __free_page(pfn_to_page(persistent_gnt->pfn)); | |
402b27f9 RPM |
1015 | kfree(persistent_gnt); |
1016 | } | |
1017 | ||
1018 | if (info->shadow[i].req.operation != BLKIF_OP_INDIRECT) | |
1019 | /* | |
1020 | * If this is not an indirect operation don't try to | |
1021 | * free indirect segments | |
1022 | */ | |
1023 | goto free_shadow; | |
1024 | ||
1025 | for (j = 0; j < INDIRECT_GREFS(segs); j++) { | |
1026 | persistent_gnt = info->shadow[i].indirect_grants[j]; | |
1027 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); | |
1028 | __free_page(pfn_to_page(persistent_gnt->pfn)); | |
1029 | kfree(persistent_gnt); | |
1030 | } | |
1031 | ||
1032 | free_shadow: | |
1033 | kfree(info->shadow[i].grants_used); | |
1034 | info->shadow[i].grants_used = NULL; | |
1035 | kfree(info->shadow[i].indirect_grants); | |
1036 | info->shadow[i].indirect_grants = NULL; | |
b7649158 RPM |
1037 | kfree(info->shadow[i].sg); |
1038 | info->shadow[i].sg = NULL; | |
402b27f9 RPM |
1039 | } |
1040 | ||
9f27ee59 JF |
1041 | /* No more gnttab callback work. */ |
1042 | gnttab_cancel_free_callback(&info->callback); | |
3467811e | 1043 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1044 | |
1045 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 1046 | flush_work(&info->work); |
9f27ee59 JF |
1047 | |
1048 | /* Free resources associated with old device channel. */ | |
86839c56 BL |
1049 | for (i = 0; i < info->nr_ring_pages; i++) { |
1050 | if (info->ring_ref[i] != GRANT_INVALID_REF) { | |
1051 | gnttab_end_foreign_access(info->ring_ref[i], 0, 0); | |
1052 | info->ring_ref[i] = GRANT_INVALID_REF; | |
1053 | } | |
9f27ee59 | 1054 | } |
86839c56 BL |
1055 | free_pages((unsigned long)info->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE)); |
1056 | info->ring.sring = NULL; | |
1057 | ||
9f27ee59 JF |
1058 | if (info->irq) |
1059 | unbind_from_irqhandler(info->irq, info); | |
1060 | info->evtchn = info->irq = 0; | |
1061 | ||
1062 | } | |
1063 | ||
0a8704a5 RPM |
1064 | static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info, |
1065 | struct blkif_response *bret) | |
9f27ee59 | 1066 | { |
d62f6918 | 1067 | int i = 0; |
b7649158 | 1068 | struct scatterlist *sg; |
0a8704a5 RPM |
1069 | char *bvec_data; |
1070 | void *shared_data; | |
402b27f9 RPM |
1071 | int nseg; |
1072 | ||
1073 | nseg = s->req.operation == BLKIF_OP_INDIRECT ? | |
1074 | s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments; | |
0a8704a5 | 1075 | |
bfe11d6d | 1076 | if (bret->operation == BLKIF_OP_READ && info->feature_persistent) { |
b7649158 RPM |
1077 | for_each_sg(s->sg, sg, nseg, i) { |
1078 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); | |
0a8704a5 RPM |
1079 | shared_data = kmap_atomic( |
1080 | pfn_to_page(s->grants_used[i]->pfn)); | |
b7649158 RPM |
1081 | bvec_data = kmap_atomic(sg_page(sg)); |
1082 | memcpy(bvec_data + sg->offset, | |
1083 | shared_data + sg->offset, | |
1084 | sg->length); | |
1085 | kunmap_atomic(bvec_data); | |
0a8704a5 | 1086 | kunmap_atomic(shared_data); |
0a8704a5 RPM |
1087 | } |
1088 | } | |
1089 | /* Add the persistent grant into the list of free grants */ | |
402b27f9 | 1090 | for (i = 0; i < nseg; i++) { |
fbe363c4 RPM |
1091 | if (gnttab_query_foreign_access(s->grants_used[i]->gref)) { |
1092 | /* | |
1093 | * If the grant is still mapped by the backend (the | |
1094 | * backend has chosen to make this grant persistent) | |
1095 | * we add it at the head of the list, so it will be | |
1096 | * reused first. | |
1097 | */ | |
bfe11d6d RPM |
1098 | if (!info->feature_persistent) |
1099 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1100 | s->grants_used[i]->gref); | |
1101 | list_add(&s->grants_used[i]->node, &info->grants); | |
fbe363c4 RPM |
1102 | info->persistent_gnts_c++; |
1103 | } else { | |
1104 | /* | |
1105 | * If the grant is not mapped by the backend we end the | |
1106 | * foreign access and add it to the tail of the list, | |
1107 | * so it will not be picked again unless we run out of | |
1108 | * persistent grants. | |
1109 | */ | |
1110 | gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL); | |
1111 | s->grants_used[i]->gref = GRANT_INVALID_REF; | |
bfe11d6d | 1112 | list_add_tail(&s->grants_used[i]->node, &info->grants); |
fbe363c4 | 1113 | } |
0a8704a5 | 1114 | } |
402b27f9 RPM |
1115 | if (s->req.operation == BLKIF_OP_INDIRECT) { |
1116 | for (i = 0; i < INDIRECT_GREFS(nseg); i++) { | |
fbe363c4 | 1117 | if (gnttab_query_foreign_access(s->indirect_grants[i]->gref)) { |
bfe11d6d RPM |
1118 | if (!info->feature_persistent) |
1119 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1120 | s->indirect_grants[i]->gref); | |
1121 | list_add(&s->indirect_grants[i]->node, &info->grants); | |
fbe363c4 RPM |
1122 | info->persistent_gnts_c++; |
1123 | } else { | |
bfe11d6d RPM |
1124 | struct page *indirect_page; |
1125 | ||
fbe363c4 | 1126 | gnttab_end_foreign_access(s->indirect_grants[i]->gref, 0, 0UL); |
bfe11d6d RPM |
1127 | /* |
1128 | * Add the used indirect page back to the list of | |
1129 | * available pages for indirect grefs. | |
1130 | */ | |
1131 | indirect_page = pfn_to_page(s->indirect_grants[i]->pfn); | |
1132 | list_add(&indirect_page->lru, &info->indirect_pages); | |
fbe363c4 | 1133 | s->indirect_grants[i]->gref = GRANT_INVALID_REF; |
bfe11d6d | 1134 | list_add_tail(&s->indirect_grants[i]->node, &info->grants); |
fbe363c4 | 1135 | } |
402b27f9 RPM |
1136 | } |
1137 | } | |
9f27ee59 JF |
1138 | } |
1139 | ||
1140 | static irqreturn_t blkif_interrupt(int irq, void *dev_id) | |
1141 | { | |
1142 | struct request *req; | |
1143 | struct blkif_response *bret; | |
1144 | RING_IDX i, rp; | |
1145 | unsigned long flags; | |
1146 | struct blkfront_info *info = (struct blkfront_info *)dev_id; | |
f530f036 | 1147 | int error; |
9f27ee59 | 1148 | |
3467811e | 1149 | spin_lock_irqsave(&info->io_lock, flags); |
9f27ee59 JF |
1150 | |
1151 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { | |
3467811e | 1152 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
1153 | return IRQ_HANDLED; |
1154 | } | |
1155 | ||
1156 | again: | |
1157 | rp = info->ring.sring->rsp_prod; | |
1158 | rmb(); /* Ensure we see queued responses up to 'rp'. */ | |
1159 | ||
1160 | for (i = info->ring.rsp_cons; i != rp; i++) { | |
1161 | unsigned long id; | |
9f27ee59 JF |
1162 | |
1163 | bret = RING_GET_RESPONSE(&info->ring, i); | |
1164 | id = bret->id; | |
6878c32e KRW |
1165 | /* |
1166 | * The backend has messed up and given us an id that we would | |
1167 | * never have given to it (we stamp it up to BLK_RING_SIZE - | |
1168 | * look in get_id_from_freelist. | |
1169 | */ | |
86839c56 | 1170 | if (id >= BLK_RING_SIZE(info)) { |
6878c32e KRW |
1171 | WARN(1, "%s: response to %s has incorrect id (%ld)\n", |
1172 | info->gd->disk_name, op_name(bret->operation), id); | |
1173 | /* We can't safely get the 'struct request' as | |
1174 | * the id is busted. */ | |
1175 | continue; | |
1176 | } | |
a945b980 | 1177 | req = info->shadow[id].request; |
9f27ee59 | 1178 | |
5ea42986 | 1179 | if (bret->operation != BLKIF_OP_DISCARD) |
0a8704a5 | 1180 | blkif_completion(&info->shadow[id], info, bret); |
9f27ee59 | 1181 | |
6878c32e KRW |
1182 | if (add_id_to_freelist(info, id)) { |
1183 | WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n", | |
1184 | info->gd->disk_name, op_name(bret->operation), id); | |
1185 | continue; | |
1186 | } | |
9f27ee59 | 1187 | |
f530f036 | 1188 | error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO; |
9f27ee59 | 1189 | switch (bret->operation) { |
ed30bf31 LD |
1190 | case BLKIF_OP_DISCARD: |
1191 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
1192 | struct request_queue *rq = info->rq; | |
6878c32e KRW |
1193 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1194 | info->gd->disk_name, op_name(bret->operation)); | |
ed30bf31 LD |
1195 | error = -EOPNOTSUPP; |
1196 | info->feature_discard = 0; | |
5ea42986 | 1197 | info->feature_secdiscard = 0; |
ed30bf31 | 1198 | queue_flag_clear(QUEUE_FLAG_DISCARD, rq); |
5ea42986 | 1199 | queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq); |
ed30bf31 LD |
1200 | } |
1201 | __blk_end_request_all(req, error); | |
1202 | break; | |
edf6ef59 | 1203 | case BLKIF_OP_FLUSH_DISKCACHE: |
9f27ee59 JF |
1204 | case BLKIF_OP_WRITE_BARRIER: |
1205 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
6878c32e KRW |
1206 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1207 | info->gd->disk_name, op_name(bret->operation)); | |
f530f036 | 1208 | error = -EOPNOTSUPP; |
dcb8baec JF |
1209 | } |
1210 | if (unlikely(bret->status == BLKIF_RSP_ERROR && | |
97e36834 | 1211 | info->shadow[id].req.u.rw.nr_segments == 0)) { |
6878c32e KRW |
1212 | printk(KERN_WARNING "blkfront: %s: empty %s op failed\n", |
1213 | info->gd->disk_name, op_name(bret->operation)); | |
dcb8baec JF |
1214 | error = -EOPNOTSUPP; |
1215 | } | |
1216 | if (unlikely(error)) { | |
1217 | if (error == -EOPNOTSUPP) | |
1218 | error = 0; | |
4913efe4 TH |
1219 | info->feature_flush = 0; |
1220 | xlvbd_flush(info); | |
9f27ee59 JF |
1221 | } |
1222 | /* fall through */ | |
1223 | case BLKIF_OP_READ: | |
1224 | case BLKIF_OP_WRITE: | |
1225 | if (unlikely(bret->status != BLKIF_RSP_OKAY)) | |
1226 | dev_dbg(&info->xbdev->dev, "Bad return from blkdev data " | |
1227 | "request: %x\n", bret->status); | |
1228 | ||
40cbbb78 | 1229 | __blk_end_request_all(req, error); |
9f27ee59 JF |
1230 | break; |
1231 | default: | |
1232 | BUG(); | |
1233 | } | |
1234 | } | |
1235 | ||
1236 | info->ring.rsp_cons = i; | |
1237 | ||
1238 | if (i != info->ring.req_prod_pvt) { | |
1239 | int more_to_do; | |
1240 | RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do); | |
1241 | if (more_to_do) | |
1242 | goto again; | |
1243 | } else | |
1244 | info->ring.sring->rsp_event = i + 1; | |
1245 | ||
1246 | kick_pending_request_queues(info); | |
1247 | ||
3467811e | 1248 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
1249 | |
1250 | return IRQ_HANDLED; | |
1251 | } | |
1252 | ||
1253 | ||
1254 | static int setup_blkring(struct xenbus_device *dev, | |
1255 | struct blkfront_info *info) | |
1256 | { | |
1257 | struct blkif_sring *sring; | |
86839c56 BL |
1258 | int err, i; |
1259 | unsigned long ring_size = info->nr_ring_pages * PAGE_SIZE; | |
1260 | grant_ref_t gref[XENBUS_MAX_RING_PAGES]; | |
9f27ee59 | 1261 | |
86839c56 BL |
1262 | for (i = 0; i < info->nr_ring_pages; i++) |
1263 | info->ring_ref[i] = GRANT_INVALID_REF; | |
9f27ee59 | 1264 | |
86839c56 BL |
1265 | sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH, |
1266 | get_order(ring_size)); | |
9f27ee59 JF |
1267 | if (!sring) { |
1268 | xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); | |
1269 | return -ENOMEM; | |
1270 | } | |
1271 | SHARED_RING_INIT(sring); | |
86839c56 | 1272 | FRONT_RING_INIT(&info->ring, sring, ring_size); |
9e973e64 | 1273 | |
86839c56 | 1274 | err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, gref); |
9f27ee59 | 1275 | if (err < 0) { |
86839c56 | 1276 | free_pages((unsigned long)sring, get_order(ring_size)); |
9f27ee59 JF |
1277 | info->ring.sring = NULL; |
1278 | goto fail; | |
1279 | } | |
86839c56 BL |
1280 | for (i = 0; i < info->nr_ring_pages; i++) |
1281 | info->ring_ref[i] = gref[i]; | |
9f27ee59 JF |
1282 | |
1283 | err = xenbus_alloc_evtchn(dev, &info->evtchn); | |
1284 | if (err) | |
1285 | goto fail; | |
1286 | ||
89c30f16 TT |
1287 | err = bind_evtchn_to_irqhandler(info->evtchn, blkif_interrupt, 0, |
1288 | "blkif", info); | |
9f27ee59 JF |
1289 | if (err <= 0) { |
1290 | xenbus_dev_fatal(dev, err, | |
1291 | "bind_evtchn_to_irqhandler failed"); | |
1292 | goto fail; | |
1293 | } | |
1294 | info->irq = err; | |
1295 | ||
1296 | return 0; | |
1297 | fail: | |
1298 | blkif_free(info, 0); | |
1299 | return err; | |
1300 | } | |
1301 | ||
1302 | ||
1303 | /* Common code used when first setting up, and when resuming. */ | |
203fd61f | 1304 | static int talk_to_blkback(struct xenbus_device *dev, |
9f27ee59 JF |
1305 | struct blkfront_info *info) |
1306 | { | |
1307 | const char *message = NULL; | |
1308 | struct xenbus_transaction xbt; | |
86839c56 BL |
1309 | int err, i; |
1310 | unsigned int max_page_order = 0; | |
1311 | unsigned int ring_page_order = 0; | |
1312 | ||
1313 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1314 | "max-ring-page-order", "%u", &max_page_order); | |
1315 | if (err != 1) | |
1316 | info->nr_ring_pages = 1; | |
1317 | else { | |
1318 | ring_page_order = min(xen_blkif_max_ring_order, max_page_order); | |
1319 | info->nr_ring_pages = 1 << ring_page_order; | |
1320 | } | |
9f27ee59 JF |
1321 | |
1322 | /* Create shared ring, alloc event channel. */ | |
1323 | err = setup_blkring(dev, info); | |
1324 | if (err) | |
1325 | goto out; | |
1326 | ||
1327 | again: | |
1328 | err = xenbus_transaction_start(&xbt); | |
1329 | if (err) { | |
1330 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
1331 | goto destroy_blkring; | |
1332 | } | |
1333 | ||
86839c56 BL |
1334 | if (info->nr_ring_pages == 1) { |
1335 | err = xenbus_printf(xbt, dev->nodename, | |
1336 | "ring-ref", "%u", info->ring_ref[0]); | |
1337 | if (err) { | |
1338 | message = "writing ring-ref"; | |
1339 | goto abort_transaction; | |
1340 | } | |
1341 | } else { | |
1342 | err = xenbus_printf(xbt, dev->nodename, | |
1343 | "ring-page-order", "%u", ring_page_order); | |
1344 | if (err) { | |
1345 | message = "writing ring-page-order"; | |
1346 | goto abort_transaction; | |
1347 | } | |
1348 | ||
1349 | for (i = 0; i < info->nr_ring_pages; i++) { | |
1350 | char ring_ref_name[RINGREF_NAME_LEN]; | |
1351 | ||
1352 | snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); | |
1353 | err = xenbus_printf(xbt, dev->nodename, ring_ref_name, | |
1354 | "%u", info->ring_ref[i]); | |
1355 | if (err) { | |
1356 | message = "writing ring-ref"; | |
1357 | goto abort_transaction; | |
1358 | } | |
1359 | } | |
9f27ee59 JF |
1360 | } |
1361 | err = xenbus_printf(xbt, dev->nodename, | |
1362 | "event-channel", "%u", info->evtchn); | |
1363 | if (err) { | |
1364 | message = "writing event-channel"; | |
1365 | goto abort_transaction; | |
1366 | } | |
3e334239 MA |
1367 | err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", |
1368 | XEN_IO_PROTO_ABI_NATIVE); | |
1369 | if (err) { | |
1370 | message = "writing protocol"; | |
1371 | goto abort_transaction; | |
1372 | } | |
0a8704a5 | 1373 | err = xenbus_printf(xbt, dev->nodename, |
cb5bd4d1 | 1374 | "feature-persistent", "%u", 1); |
0a8704a5 RPM |
1375 | if (err) |
1376 | dev_warn(&dev->dev, | |
1377 | "writing persistent grants feature to xenbus"); | |
9f27ee59 JF |
1378 | |
1379 | err = xenbus_transaction_end(xbt, 0); | |
1380 | if (err) { | |
1381 | if (err == -EAGAIN) | |
1382 | goto again; | |
1383 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
1384 | goto destroy_blkring; | |
1385 | } | |
1386 | ||
86839c56 BL |
1387 | for (i = 0; i < BLK_RING_SIZE(info); i++) |
1388 | info->shadow[i].req.u.rw.id = i+1; | |
1389 | info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; | |
9f27ee59 JF |
1390 | xenbus_switch_state(dev, XenbusStateInitialised); |
1391 | ||
1392 | return 0; | |
1393 | ||
1394 | abort_transaction: | |
1395 | xenbus_transaction_end(xbt, 1); | |
1396 | if (message) | |
1397 | xenbus_dev_fatal(dev, err, "%s", message); | |
1398 | destroy_blkring: | |
1399 | blkif_free(info, 0); | |
1400 | out: | |
1401 | return err; | |
1402 | } | |
1403 | ||
9f27ee59 JF |
1404 | /** |
1405 | * Entry point to this code when a new device is created. Allocate the basic | |
1406 | * structures and the ring buffer for communication with the backend, and | |
1407 | * inform the backend of the appropriate details for those. Switch to | |
1408 | * Initialised state. | |
1409 | */ | |
1410 | static int blkfront_probe(struct xenbus_device *dev, | |
1411 | const struct xenbus_device_id *id) | |
1412 | { | |
86839c56 | 1413 | int err, vdevice; |
9f27ee59 JF |
1414 | struct blkfront_info *info; |
1415 | ||
1416 | /* FIXME: Use dynamic device id if this is not set. */ | |
1417 | err = xenbus_scanf(XBT_NIL, dev->nodename, | |
1418 | "virtual-device", "%i", &vdevice); | |
1419 | if (err != 1) { | |
9246b5f0 CL |
1420 | /* go looking in the extended area instead */ |
1421 | err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext", | |
1422 | "%i", &vdevice); | |
1423 | if (err != 1) { | |
1424 | xenbus_dev_fatal(dev, err, "reading virtual-device"); | |
1425 | return err; | |
1426 | } | |
9f27ee59 JF |
1427 | } |
1428 | ||
b98a409b SS |
1429 | if (xen_hvm_domain()) { |
1430 | char *type; | |
1431 | int len; | |
1432 | /* no unplug has been done: do not hook devices != xen vbds */ | |
51c71a3b | 1433 | if (xen_has_pv_and_legacy_disk_devices()) { |
b98a409b SS |
1434 | int major; |
1435 | ||
1436 | if (!VDEV_IS_EXTENDED(vdevice)) | |
1437 | major = BLKIF_MAJOR(vdevice); | |
1438 | else | |
1439 | major = XENVBD_MAJOR; | |
1440 | ||
1441 | if (major != XENVBD_MAJOR) { | |
1442 | printk(KERN_INFO | |
1443 | "%s: HVM does not support vbd %d as xen block device\n", | |
02f1f217 | 1444 | __func__, vdevice); |
b98a409b SS |
1445 | return -ENODEV; |
1446 | } | |
1447 | } | |
1448 | /* do not create a PV cdrom device if we are an HVM guest */ | |
1449 | type = xenbus_read(XBT_NIL, dev->nodename, "device-type", &len); | |
1450 | if (IS_ERR(type)) | |
1451 | return -ENODEV; | |
1452 | if (strncmp(type, "cdrom", 5) == 0) { | |
1453 | kfree(type); | |
c1c5413a SS |
1454 | return -ENODEV; |
1455 | } | |
b98a409b | 1456 | kfree(type); |
c1c5413a | 1457 | } |
9f27ee59 JF |
1458 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
1459 | if (!info) { | |
1460 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
1461 | return -ENOMEM; | |
1462 | } | |
1463 | ||
b70f5fa0 | 1464 | mutex_init(&info->mutex); |
3467811e | 1465 | spin_lock_init(&info->io_lock); |
9f27ee59 JF |
1466 | info->xbdev = dev; |
1467 | info->vdevice = vdevice; | |
bfe11d6d RPM |
1468 | INIT_LIST_HEAD(&info->grants); |
1469 | INIT_LIST_HEAD(&info->indirect_pages); | |
0a8704a5 | 1470 | info->persistent_gnts_c = 0; |
9f27ee59 JF |
1471 | info->connected = BLKIF_STATE_DISCONNECTED; |
1472 | INIT_WORK(&info->work, blkif_restart_queue); | |
1473 | ||
9f27ee59 JF |
1474 | /* Front end dir is a number, which is used as the id. */ |
1475 | info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); | |
a1b4b12b | 1476 | dev_set_drvdata(&dev->dev, info); |
9f27ee59 | 1477 | |
9f27ee59 JF |
1478 | return 0; |
1479 | } | |
1480 | ||
402b27f9 RPM |
1481 | static void split_bio_end(struct bio *bio, int error) |
1482 | { | |
1483 | struct split_bio *split_bio = bio->bi_private; | |
1484 | ||
1485 | if (error) | |
1486 | split_bio->err = error; | |
1487 | ||
1488 | if (atomic_dec_and_test(&split_bio->pending)) { | |
1489 | split_bio->bio->bi_phys_segments = 0; | |
1490 | bio_endio(split_bio->bio, split_bio->err); | |
1491 | kfree(split_bio); | |
1492 | } | |
1493 | bio_put(bio); | |
1494 | } | |
9f27ee59 JF |
1495 | |
1496 | static int blkif_recover(struct blkfront_info *info) | |
1497 | { | |
1498 | int i; | |
402b27f9 | 1499 | struct request *req, *n; |
9f27ee59 | 1500 | struct blk_shadow *copy; |
402b27f9 RPM |
1501 | int rc; |
1502 | struct bio *bio, *cloned_bio; | |
1503 | struct bio_list bio_list, merge_bio; | |
1504 | unsigned int segs, offset; | |
1505 | int pending, size; | |
1506 | struct split_bio *split_bio; | |
1507 | struct list_head requests; | |
9f27ee59 JF |
1508 | |
1509 | /* Stage 1: Make a safe copy of the shadow state. */ | |
29d0b218 | 1510 | copy = kmemdup(info->shadow, sizeof(info->shadow), |
a144ff09 | 1511 | GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); |
9f27ee59 JF |
1512 | if (!copy) |
1513 | return -ENOMEM; | |
9f27ee59 JF |
1514 | |
1515 | /* Stage 2: Set up free list. */ | |
1516 | memset(&info->shadow, 0, sizeof(info->shadow)); | |
86839c56 | 1517 | for (i = 0; i < BLK_RING_SIZE(info); i++) |
97e36834 | 1518 | info->shadow[i].req.u.rw.id = i+1; |
9f27ee59 | 1519 | info->shadow_free = info->ring.req_prod_pvt; |
86839c56 | 1520 | info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; |
9f27ee59 | 1521 | |
402b27f9 RPM |
1522 | rc = blkfront_setup_indirect(info); |
1523 | if (rc) { | |
1524 | kfree(copy); | |
1525 | return rc; | |
1526 | } | |
1527 | ||
1528 | segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
1529 | blk_queue_max_segments(info->rq, segs); | |
1530 | bio_list_init(&bio_list); | |
1531 | INIT_LIST_HEAD(&requests); | |
86839c56 | 1532 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
9f27ee59 | 1533 | /* Not in use? */ |
a945b980 | 1534 | if (!copy[i].request) |
9f27ee59 JF |
1535 | continue; |
1536 | ||
402b27f9 RPM |
1537 | /* |
1538 | * Get the bios in the request so we can re-queue them. | |
1539 | */ | |
1540 | if (copy[i].request->cmd_flags & | |
1541 | (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) { | |
1542 | /* | |
1543 | * Flush operations don't contain bios, so | |
1544 | * we need to requeue the whole request | |
1545 | */ | |
1546 | list_add(©[i].request->queuelist, &requests); | |
1547 | continue; | |
5ea42986 | 1548 | } |
402b27f9 RPM |
1549 | merge_bio.head = copy[i].request->bio; |
1550 | merge_bio.tail = copy[i].request->biotail; | |
1551 | bio_list_merge(&bio_list, &merge_bio); | |
1552 | copy[i].request->bio = NULL; | |
3bb8c98e | 1553 | blk_end_request_all(copy[i].request, 0); |
9f27ee59 JF |
1554 | } |
1555 | ||
1556 | kfree(copy); | |
1557 | ||
402b27f9 RPM |
1558 | /* |
1559 | * Empty the queue, this is important because we might have | |
1560 | * requests in the queue with more segments than what we | |
1561 | * can handle now. | |
1562 | */ | |
1563 | spin_lock_irq(&info->io_lock); | |
1564 | while ((req = blk_fetch_request(info->rq)) != NULL) { | |
1565 | if (req->cmd_flags & | |
1566 | (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) { | |
1567 | list_add(&req->queuelist, &requests); | |
1568 | continue; | |
1569 | } | |
1570 | merge_bio.head = req->bio; | |
1571 | merge_bio.tail = req->biotail; | |
1572 | bio_list_merge(&bio_list, &merge_bio); | |
1573 | req->bio = NULL; | |
1574 | if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) | |
1575 | pr_alert("diskcache flush request found!\n"); | |
3bb8c98e | 1576 | __blk_end_request_all(req, 0); |
402b27f9 RPM |
1577 | } |
1578 | spin_unlock_irq(&info->io_lock); | |
1579 | ||
9f27ee59 JF |
1580 | xenbus_switch_state(info->xbdev, XenbusStateConnected); |
1581 | ||
3467811e | 1582 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1583 | |
1584 | /* Now safe for us to use the shared ring */ | |
1585 | info->connected = BLKIF_STATE_CONNECTED; | |
1586 | ||
9f27ee59 JF |
1587 | /* Kick any other new requests queued since we resumed */ |
1588 | kick_pending_request_queues(info); | |
1589 | ||
402b27f9 RPM |
1590 | list_for_each_entry_safe(req, n, &requests, queuelist) { |
1591 | /* Requeue pending requests (flush or discard) */ | |
1592 | list_del_init(&req->queuelist); | |
1593 | BUG_ON(req->nr_phys_segments > segs); | |
1594 | blk_requeue_request(info->rq, req); | |
1595 | } | |
3467811e | 1596 | spin_unlock_irq(&info->io_lock); |
9f27ee59 | 1597 | |
402b27f9 RPM |
1598 | while ((bio = bio_list_pop(&bio_list)) != NULL) { |
1599 | /* Traverse the list of pending bios and re-queue them */ | |
1600 | if (bio_segments(bio) > segs) { | |
1601 | /* | |
1602 | * This bio has more segments than what we can | |
1603 | * handle, we have to split it. | |
1604 | */ | |
1605 | pending = (bio_segments(bio) + segs - 1) / segs; | |
1606 | split_bio = kzalloc(sizeof(*split_bio), GFP_NOIO); | |
1607 | BUG_ON(split_bio == NULL); | |
1608 | atomic_set(&split_bio->pending, pending); | |
1609 | split_bio->bio = bio; | |
1610 | for (i = 0; i < pending; i++) { | |
1611 | offset = (i * segs * PAGE_SIZE) >> 9; | |
1612 | size = min((unsigned int)(segs * PAGE_SIZE) >> 9, | |
4f024f37 | 1613 | (unsigned int)bio_sectors(bio) - offset); |
402b27f9 RPM |
1614 | cloned_bio = bio_clone(bio, GFP_NOIO); |
1615 | BUG_ON(cloned_bio == NULL); | |
6678d83f | 1616 | bio_trim(cloned_bio, offset, size); |
402b27f9 RPM |
1617 | cloned_bio->bi_private = split_bio; |
1618 | cloned_bio->bi_end_io = split_bio_end; | |
1619 | submit_bio(cloned_bio->bi_rw, cloned_bio); | |
1620 | } | |
1621 | /* | |
1622 | * Now we have to wait for all those smaller bios to | |
1623 | * end, so we can also end the "parent" bio. | |
1624 | */ | |
1625 | continue; | |
1626 | } | |
1627 | /* We don't need to split this bio */ | |
1628 | submit_bio(bio->bi_rw, bio); | |
1629 | } | |
1630 | ||
9f27ee59 JF |
1631 | return 0; |
1632 | } | |
1633 | ||
1634 | /** | |
1635 | * We are reconnecting to the backend, due to a suspend/resume, or a backend | |
1636 | * driver restart. We tear down our blkif structure and recreate it, but | |
1637 | * leave the device-layer structures intact so that this is transparent to the | |
1638 | * rest of the kernel. | |
1639 | */ | |
1640 | static int blkfront_resume(struct xenbus_device *dev) | |
1641 | { | |
a1b4b12b | 1642 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 JF |
1643 | int err; |
1644 | ||
1645 | dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename); | |
1646 | ||
1647 | blkif_free(info, info->connected == BLKIF_STATE_CONNECTED); | |
1648 | ||
203fd61f | 1649 | err = talk_to_blkback(dev, info); |
402b27f9 RPM |
1650 | |
1651 | /* | |
1652 | * We have to wait for the backend to switch to | |
1653 | * connected state, since we want to read which | |
1654 | * features it supports. | |
1655 | */ | |
9f27ee59 JF |
1656 | |
1657 | return err; | |
1658 | } | |
1659 | ||
b70f5fa0 DS |
1660 | static void |
1661 | blkfront_closing(struct blkfront_info *info) | |
1662 | { | |
1663 | struct xenbus_device *xbdev = info->xbdev; | |
1664 | struct block_device *bdev = NULL; | |
1665 | ||
1666 | mutex_lock(&info->mutex); | |
1667 | ||
1668 | if (xbdev->state == XenbusStateClosing) { | |
1669 | mutex_unlock(&info->mutex); | |
1670 | return; | |
1671 | } | |
1672 | ||
1673 | if (info->gd) | |
1674 | bdev = bdget_disk(info->gd, 0); | |
1675 | ||
1676 | mutex_unlock(&info->mutex); | |
1677 | ||
1678 | if (!bdev) { | |
1679 | xenbus_frontend_closed(xbdev); | |
1680 | return; | |
1681 | } | |
1682 | ||
1683 | mutex_lock(&bdev->bd_mutex); | |
1684 | ||
7b32d104 | 1685 | if (bdev->bd_openers) { |
b70f5fa0 DS |
1686 | xenbus_dev_error(xbdev, -EBUSY, |
1687 | "Device in use; refusing to close"); | |
1688 | xenbus_switch_state(xbdev, XenbusStateClosing); | |
1689 | } else { | |
1690 | xlvbd_release_gendisk(info); | |
1691 | xenbus_frontend_closed(xbdev); | |
1692 | } | |
1693 | ||
1694 | mutex_unlock(&bdev->bd_mutex); | |
1695 | bdput(bdev); | |
1696 | } | |
9f27ee59 | 1697 | |
ed30bf31 LD |
1698 | static void blkfront_setup_discard(struct blkfront_info *info) |
1699 | { | |
1700 | int err; | |
ed30bf31 LD |
1701 | unsigned int discard_granularity; |
1702 | unsigned int discard_alignment; | |
5ea42986 | 1703 | unsigned int discard_secure; |
ed30bf31 | 1704 | |
1c8cad6c OH |
1705 | info->feature_discard = 1; |
1706 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1707 | "discard-granularity", "%u", &discard_granularity, | |
1708 | "discard-alignment", "%u", &discard_alignment, | |
1709 | NULL); | |
1710 | if (!err) { | |
1711 | info->discard_granularity = discard_granularity; | |
1712 | info->discard_alignment = discard_alignment; | |
1713 | } | |
1714 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1715 | "discard-secure", "%d", &discard_secure, | |
1716 | NULL); | |
1717 | if (!err) | |
1718 | info->feature_secdiscard = !!discard_secure; | |
ed30bf31 LD |
1719 | } |
1720 | ||
402b27f9 RPM |
1721 | static int blkfront_setup_indirect(struct blkfront_info *info) |
1722 | { | |
1723 | unsigned int indirect_segments, segs; | |
1724 | int err, i; | |
1725 | ||
1726 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1727 | "feature-max-indirect-segments", "%u", &indirect_segments, | |
1728 | NULL); | |
1729 | if (err) { | |
1730 | info->max_indirect_segments = 0; | |
1731 | segs = BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
1732 | } else { | |
1733 | info->max_indirect_segments = min(indirect_segments, | |
1734 | xen_blkif_max_segments); | |
1735 | segs = info->max_indirect_segments; | |
1736 | } | |
402b27f9 | 1737 | |
86839c56 | 1738 | err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE(info)); |
402b27f9 RPM |
1739 | if (err) |
1740 | goto out_of_memory; | |
1741 | ||
bfe11d6d RPM |
1742 | if (!info->feature_persistent && info->max_indirect_segments) { |
1743 | /* | |
1744 | * We are using indirect descriptors but not persistent | |
1745 | * grants, we need to allocate a set of pages that can be | |
1746 | * used for mapping indirect grefs | |
1747 | */ | |
86839c56 | 1748 | int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE(info); |
bfe11d6d RPM |
1749 | |
1750 | BUG_ON(!list_empty(&info->indirect_pages)); | |
1751 | for (i = 0; i < num; i++) { | |
1752 | struct page *indirect_page = alloc_page(GFP_NOIO); | |
1753 | if (!indirect_page) | |
1754 | goto out_of_memory; | |
1755 | list_add(&indirect_page->lru, &info->indirect_pages); | |
1756 | } | |
1757 | } | |
1758 | ||
86839c56 | 1759 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1760 | info->shadow[i].grants_used = kzalloc( |
1761 | sizeof(info->shadow[i].grants_used[0]) * segs, | |
1762 | GFP_NOIO); | |
b7649158 | 1763 | info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * segs, GFP_NOIO); |
402b27f9 RPM |
1764 | if (info->max_indirect_segments) |
1765 | info->shadow[i].indirect_grants = kzalloc( | |
1766 | sizeof(info->shadow[i].indirect_grants[0]) * | |
1767 | INDIRECT_GREFS(segs), | |
1768 | GFP_NOIO); | |
1769 | if ((info->shadow[i].grants_used == NULL) || | |
b7649158 | 1770 | (info->shadow[i].sg == NULL) || |
402b27f9 RPM |
1771 | (info->max_indirect_segments && |
1772 | (info->shadow[i].indirect_grants == NULL))) | |
1773 | goto out_of_memory; | |
b7649158 | 1774 | sg_init_table(info->shadow[i].sg, segs); |
402b27f9 RPM |
1775 | } |
1776 | ||
1777 | ||
1778 | return 0; | |
1779 | ||
1780 | out_of_memory: | |
86839c56 | 1781 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1782 | kfree(info->shadow[i].grants_used); |
1783 | info->shadow[i].grants_used = NULL; | |
b7649158 RPM |
1784 | kfree(info->shadow[i].sg); |
1785 | info->shadow[i].sg = NULL; | |
402b27f9 RPM |
1786 | kfree(info->shadow[i].indirect_grants); |
1787 | info->shadow[i].indirect_grants = NULL; | |
1788 | } | |
bfe11d6d RPM |
1789 | if (!list_empty(&info->indirect_pages)) { |
1790 | struct page *indirect_page, *n; | |
1791 | list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) { | |
1792 | list_del(&indirect_page->lru); | |
1793 | __free_page(indirect_page); | |
1794 | } | |
1795 | } | |
402b27f9 RPM |
1796 | return -ENOMEM; |
1797 | } | |
1798 | ||
9f27ee59 JF |
1799 | /* |
1800 | * Invoked when the backend is finally 'ready' (and has told produced | |
1801 | * the details about the physical device - #sectors, size, etc). | |
1802 | */ | |
1803 | static void blkfront_connect(struct blkfront_info *info) | |
1804 | { | |
1805 | unsigned long long sectors; | |
1806 | unsigned long sector_size; | |
7c4d7d71 | 1807 | unsigned int physical_sector_size; |
9f27ee59 JF |
1808 | unsigned int binfo; |
1809 | int err; | |
0a8704a5 | 1810 | int barrier, flush, discard, persistent; |
9f27ee59 | 1811 | |
1fa73be6 S |
1812 | switch (info->connected) { |
1813 | case BLKIF_STATE_CONNECTED: | |
1814 | /* | |
1815 | * Potentially, the back-end may be signalling | |
1816 | * a capacity change; update the capacity. | |
1817 | */ | |
1818 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1819 | "sectors", "%Lu", §ors); | |
1820 | if (XENBUS_EXIST_ERR(err)) | |
1821 | return; | |
1822 | printk(KERN_INFO "Setting capacity to %Lu\n", | |
1823 | sectors); | |
1824 | set_capacity(info->gd, sectors); | |
2def141e | 1825 | revalidate_disk(info->gd); |
1fa73be6 | 1826 | |
402b27f9 | 1827 | return; |
1fa73be6 | 1828 | case BLKIF_STATE_SUSPENDED: |
402b27f9 RPM |
1829 | /* |
1830 | * If we are recovering from suspension, we need to wait | |
1831 | * for the backend to announce it's features before | |
1832 | * reconnecting, at least we need to know if the backend | |
1833 | * supports indirect descriptors, and how many. | |
1834 | */ | |
1835 | blkif_recover(info); | |
9f27ee59 JF |
1836 | return; |
1837 | ||
b4dddb49 JF |
1838 | default: |
1839 | break; | |
1fa73be6 | 1840 | } |
9f27ee59 JF |
1841 | |
1842 | dev_dbg(&info->xbdev->dev, "%s:%s.\n", | |
1843 | __func__, info->xbdev->otherend); | |
1844 | ||
1845 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1846 | "sectors", "%llu", §ors, | |
1847 | "info", "%u", &binfo, | |
1848 | "sector-size", "%lu", §or_size, | |
1849 | NULL); | |
1850 | if (err) { | |
1851 | xenbus_dev_fatal(info->xbdev, err, | |
1852 | "reading backend fields at %s", | |
1853 | info->xbdev->otherend); | |
1854 | return; | |
1855 | } | |
1856 | ||
7c4d7d71 SB |
1857 | /* |
1858 | * physcial-sector-size is a newer field, so old backends may not | |
1859 | * provide this. Assume physical sector size to be the same as | |
1860 | * sector_size in that case. | |
1861 | */ | |
1862 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1863 | "physical-sector-size", "%u", &physical_sector_size); | |
1864 | if (err != 1) | |
1865 | physical_sector_size = sector_size; | |
1866 | ||
edf6ef59 | 1867 | info->feature_flush = 0; |
edf6ef59 | 1868 | |
9f27ee59 | 1869 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, |
4352b47a | 1870 | "feature-barrier", "%d", &barrier, |
9f27ee59 | 1871 | NULL); |
7901d141 JF |
1872 | |
1873 | /* | |
1874 | * If there's no "feature-barrier" defined, then it means | |
1875 | * we're dealing with a very old backend which writes | |
4913efe4 | 1876 | * synchronously; nothing to do. |
7901d141 | 1877 | * |
6958f145 | 1878 | * If there are barriers, then we use flush. |
7901d141 | 1879 | */ |
fdf9b965 | 1880 | if (!err && barrier) |
be2f8373 | 1881 | info->feature_flush = REQ_FLUSH | REQ_FUA; |
edf6ef59 KRW |
1882 | /* |
1883 | * And if there is "feature-flush-cache" use that above | |
1884 | * barriers. | |
1885 | */ | |
1886 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1887 | "feature-flush-cache", "%d", &flush, | |
1888 | NULL); | |
9f27ee59 | 1889 | |
fdf9b965 | 1890 | if (!err && flush) |
edf6ef59 | 1891 | info->feature_flush = REQ_FLUSH; |
ed30bf31 LD |
1892 | |
1893 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1894 | "feature-discard", "%d", &discard, | |
1895 | NULL); | |
1896 | ||
1897 | if (!err && discard) | |
1898 | blkfront_setup_discard(info); | |
1899 | ||
0a8704a5 RPM |
1900 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, |
1901 | "feature-persistent", "%u", &persistent, | |
1902 | NULL); | |
1903 | if (err) | |
1904 | info->feature_persistent = 0; | |
1905 | else | |
1906 | info->feature_persistent = persistent; | |
1907 | ||
402b27f9 RPM |
1908 | err = blkfront_setup_indirect(info); |
1909 | if (err) { | |
1910 | xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s", | |
1911 | info->xbdev->otherend); | |
1912 | return; | |
1913 | } | |
1914 | ||
7c4d7d71 SB |
1915 | err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size, |
1916 | physical_sector_size); | |
9f27ee59 JF |
1917 | if (err) { |
1918 | xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", | |
1919 | info->xbdev->otherend); | |
1920 | return; | |
1921 | } | |
1922 | ||
1923 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1924 | ||
1925 | /* Kick pending requests. */ | |
3467811e | 1926 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1927 | info->connected = BLKIF_STATE_CONNECTED; |
1928 | kick_pending_request_queues(info); | |
3467811e | 1929 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1930 | |
1931 | add_disk(info->gd); | |
1d78d705 CL |
1932 | |
1933 | info->is_ready = 1; | |
9f27ee59 JF |
1934 | } |
1935 | ||
9f27ee59 JF |
1936 | /** |
1937 | * Callback received when the backend's state changes. | |
1938 | */ | |
203fd61f | 1939 | static void blkback_changed(struct xenbus_device *dev, |
9f27ee59 JF |
1940 | enum xenbus_state backend_state) |
1941 | { | |
a1b4b12b | 1942 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 | 1943 | |
203fd61f | 1944 | dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); |
9f27ee59 JF |
1945 | |
1946 | switch (backend_state) { | |
9f27ee59 | 1947 | case XenbusStateInitWait: |
a9b54bb9 BL |
1948 | if (dev->state != XenbusStateInitialising) |
1949 | break; | |
8ab0144a BL |
1950 | if (talk_to_blkback(dev, info)) { |
1951 | kfree(info); | |
1952 | dev_set_drvdata(&dev->dev, NULL); | |
1953 | break; | |
1954 | } | |
1955 | case XenbusStateInitialising: | |
9f27ee59 | 1956 | case XenbusStateInitialised: |
b78c9512 NI |
1957 | case XenbusStateReconfiguring: |
1958 | case XenbusStateReconfigured: | |
9f27ee59 | 1959 | case XenbusStateUnknown: |
9f27ee59 JF |
1960 | break; |
1961 | ||
1962 | case XenbusStateConnected: | |
1963 | blkfront_connect(info); | |
1964 | break; | |
1965 | ||
36613717 DV |
1966 | case XenbusStateClosed: |
1967 | if (dev->state == XenbusStateClosed) | |
1968 | break; | |
1969 | /* Missed the backend's Closing state -- fallthrough */ | |
9f27ee59 | 1970 | case XenbusStateClosing: |
b70f5fa0 | 1971 | blkfront_closing(info); |
9f27ee59 JF |
1972 | break; |
1973 | } | |
1974 | } | |
1975 | ||
fa1bd359 | 1976 | static int blkfront_remove(struct xenbus_device *xbdev) |
9f27ee59 | 1977 | { |
fa1bd359 DS |
1978 | struct blkfront_info *info = dev_get_drvdata(&xbdev->dev); |
1979 | struct block_device *bdev = NULL; | |
1980 | struct gendisk *disk; | |
9f27ee59 | 1981 | |
fa1bd359 | 1982 | dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename); |
9f27ee59 JF |
1983 | |
1984 | blkif_free(info, 0); | |
1985 | ||
fa1bd359 DS |
1986 | mutex_lock(&info->mutex); |
1987 | ||
1988 | disk = info->gd; | |
1989 | if (disk) | |
1990 | bdev = bdget_disk(disk, 0); | |
1991 | ||
1992 | info->xbdev = NULL; | |
1993 | mutex_unlock(&info->mutex); | |
1994 | ||
1995 | if (!bdev) { | |
1996 | kfree(info); | |
1997 | return 0; | |
1998 | } | |
1999 | ||
2000 | /* | |
2001 | * The xbdev was removed before we reached the Closed | |
2002 | * state. See if it's safe to remove the disk. If the bdev | |
2003 | * isn't closed yet, we let release take care of it. | |
2004 | */ | |
2005 | ||
2006 | mutex_lock(&bdev->bd_mutex); | |
2007 | info = disk->private_data; | |
2008 | ||
d54142c7 DS |
2009 | dev_warn(disk_to_dev(disk), |
2010 | "%s was hot-unplugged, %d stale handles\n", | |
2011 | xbdev->nodename, bdev->bd_openers); | |
2012 | ||
7b32d104 | 2013 | if (info && !bdev->bd_openers) { |
fa1bd359 DS |
2014 | xlvbd_release_gendisk(info); |
2015 | disk->private_data = NULL; | |
0e345826 | 2016 | kfree(info); |
fa1bd359 DS |
2017 | } |
2018 | ||
2019 | mutex_unlock(&bdev->bd_mutex); | |
2020 | bdput(bdev); | |
9f27ee59 JF |
2021 | |
2022 | return 0; | |
2023 | } | |
2024 | ||
1d78d705 CL |
2025 | static int blkfront_is_ready(struct xenbus_device *dev) |
2026 | { | |
a1b4b12b | 2027 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
1d78d705 | 2028 | |
5d7ed20e | 2029 | return info->is_ready && info->xbdev; |
1d78d705 CL |
2030 | } |
2031 | ||
a63c848b | 2032 | static int blkif_open(struct block_device *bdev, fmode_t mode) |
9f27ee59 | 2033 | { |
13961743 DS |
2034 | struct gendisk *disk = bdev->bd_disk; |
2035 | struct blkfront_info *info; | |
2036 | int err = 0; | |
6e9624b8 | 2037 | |
2a48fc0a | 2038 | mutex_lock(&blkfront_mutex); |
6e9624b8 | 2039 | |
13961743 DS |
2040 | info = disk->private_data; |
2041 | if (!info) { | |
2042 | /* xbdev gone */ | |
2043 | err = -ERESTARTSYS; | |
2044 | goto out; | |
2045 | } | |
2046 | ||
2047 | mutex_lock(&info->mutex); | |
2048 | ||
2049 | if (!info->gd) | |
2050 | /* xbdev is closed */ | |
2051 | err = -ERESTARTSYS; | |
2052 | ||
2053 | mutex_unlock(&info->mutex); | |
2054 | ||
13961743 | 2055 | out: |
2a48fc0a | 2056 | mutex_unlock(&blkfront_mutex); |
13961743 | 2057 | return err; |
9f27ee59 JF |
2058 | } |
2059 | ||
db2a144b | 2060 | static void blkif_release(struct gendisk *disk, fmode_t mode) |
9f27ee59 | 2061 | { |
a63c848b | 2062 | struct blkfront_info *info = disk->private_data; |
7fd152f4 DS |
2063 | struct block_device *bdev; |
2064 | struct xenbus_device *xbdev; | |
2065 | ||
2a48fc0a | 2066 | mutex_lock(&blkfront_mutex); |
7fd152f4 DS |
2067 | |
2068 | bdev = bdget_disk(disk, 0); | |
7fd152f4 | 2069 | |
2f089cb8 FP |
2070 | if (!bdev) { |
2071 | WARN(1, "Block device %s yanked out from us!\n", disk->disk_name); | |
2072 | goto out_mutex; | |
2073 | } | |
acfca3c6 DS |
2074 | if (bdev->bd_openers) |
2075 | goto out; | |
2076 | ||
7fd152f4 DS |
2077 | /* |
2078 | * Check if we have been instructed to close. We will have | |
2079 | * deferred this request, because the bdev was still open. | |
2080 | */ | |
2081 | ||
2082 | mutex_lock(&info->mutex); | |
2083 | xbdev = info->xbdev; | |
2084 | ||
2085 | if (xbdev && xbdev->state == XenbusStateClosing) { | |
2086 | /* pending switch to state closed */ | |
d54142c7 | 2087 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2088 | xlvbd_release_gendisk(info); |
2089 | xenbus_frontend_closed(info->xbdev); | |
2090 | } | |
2091 | ||
2092 | mutex_unlock(&info->mutex); | |
2093 | ||
2094 | if (!xbdev) { | |
2095 | /* sudden device removal */ | |
d54142c7 | 2096 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2097 | xlvbd_release_gendisk(info); |
2098 | disk->private_data = NULL; | |
2099 | kfree(info); | |
9f27ee59 | 2100 | } |
7fd152f4 | 2101 | |
a4cc14ec | 2102 | out: |
dad5cf65 | 2103 | bdput(bdev); |
2f089cb8 | 2104 | out_mutex: |
2a48fc0a | 2105 | mutex_unlock(&blkfront_mutex); |
9f27ee59 JF |
2106 | } |
2107 | ||
83d5cde4 | 2108 | static const struct block_device_operations xlvbd_block_fops = |
9f27ee59 JF |
2109 | { |
2110 | .owner = THIS_MODULE, | |
a63c848b AV |
2111 | .open = blkif_open, |
2112 | .release = blkif_release, | |
597592d9 | 2113 | .getgeo = blkif_getgeo, |
8a6cfeb6 | 2114 | .ioctl = blkif_ioctl, |
9f27ee59 JF |
2115 | }; |
2116 | ||
2117 | ||
ec9c42ec | 2118 | static const struct xenbus_device_id blkfront_ids[] = { |
9f27ee59 JF |
2119 | { "vbd" }, |
2120 | { "" } | |
2121 | }; | |
2122 | ||
95afae48 DV |
2123 | static struct xenbus_driver blkfront_driver = { |
2124 | .ids = blkfront_ids, | |
9f27ee59 JF |
2125 | .probe = blkfront_probe, |
2126 | .remove = blkfront_remove, | |
2127 | .resume = blkfront_resume, | |
203fd61f | 2128 | .otherend_changed = blkback_changed, |
1d78d705 | 2129 | .is_ready = blkfront_is_ready, |
95afae48 | 2130 | }; |
9f27ee59 JF |
2131 | |
2132 | static int __init xlblk_init(void) | |
2133 | { | |
469738e6 LE |
2134 | int ret; |
2135 | ||
6e833587 | 2136 | if (!xen_domain()) |
9f27ee59 JF |
2137 | return -ENODEV; |
2138 | ||
86839c56 BL |
2139 | if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) { |
2140 | pr_info("Invalid max_ring_order (%d), will use default max: %d.\n", | |
2141 | xen_blkif_max_ring_order, XENBUS_MAX_RING_PAGE_ORDER); | |
2142 | xen_blkif_max_ring_order = 0; | |
2143 | } | |
2144 | ||
51c71a3b | 2145 | if (!xen_has_pv_disk_devices()) |
b9136d20 IM |
2146 | return -ENODEV; |
2147 | ||
9f27ee59 JF |
2148 | if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { |
2149 | printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", | |
2150 | XENVBD_MAJOR, DEV_NAME); | |
2151 | return -ENODEV; | |
2152 | } | |
2153 | ||
73db144b | 2154 | ret = xenbus_register_frontend(&blkfront_driver); |
469738e6 LE |
2155 | if (ret) { |
2156 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2157 | return ret; | |
2158 | } | |
2159 | ||
2160 | return 0; | |
9f27ee59 JF |
2161 | } |
2162 | module_init(xlblk_init); | |
2163 | ||
2164 | ||
5a60d0cd | 2165 | static void __exit xlblk_exit(void) |
9f27ee59 | 2166 | { |
8605067f JB |
2167 | xenbus_unregister_driver(&blkfront_driver); |
2168 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2169 | kfree(minors); | |
9f27ee59 JF |
2170 | } |
2171 | module_exit(xlblk_exit); | |
2172 | ||
2173 | MODULE_DESCRIPTION("Xen virtual block device frontend"); | |
2174 | MODULE_LICENSE("GPL"); | |
2175 | MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR); | |
d2f0c52b | 2176 | MODULE_ALIAS("xen:vbd"); |
4f93f09b | 2177 | MODULE_ALIAS("xenblk"); |