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 | |
667c78af | 101 | #define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE) |
9f27ee59 JF |
102 | |
103 | /* | |
104 | * We have one of these per vbd, whether ide, scsi or 'other'. They | |
105 | * hang in private_data off the gendisk structure. We may end up | |
106 | * putting all kinds of interesting stuff here :-) | |
107 | */ | |
108 | struct blkfront_info | |
109 | { | |
3467811e | 110 | spinlock_t io_lock; |
b70f5fa0 | 111 | struct mutex mutex; |
9f27ee59 | 112 | struct xenbus_device *xbdev; |
9f27ee59 JF |
113 | struct gendisk *gd; |
114 | int vdevice; | |
115 | blkif_vdev_t handle; | |
116 | enum blkif_state connected; | |
117 | int ring_ref; | |
118 | struct blkif_front_ring ring; | |
119 | unsigned int evtchn, irq; | |
120 | struct request_queue *rq; | |
121 | struct work_struct work; | |
122 | struct gnttab_free_callback callback; | |
123 | struct blk_shadow shadow[BLK_RING_SIZE]; | |
bfe11d6d RPM |
124 | struct list_head grants; |
125 | struct list_head indirect_pages; | |
0a8704a5 | 126 | unsigned int persistent_gnts_c; |
9f27ee59 | 127 | unsigned long shadow_free; |
4913efe4 | 128 | unsigned int feature_flush; |
edf6ef59 | 129 | unsigned int flush_op; |
5ea42986 KRW |
130 | unsigned int feature_discard:1; |
131 | unsigned int feature_secdiscard:1; | |
ed30bf31 LD |
132 | unsigned int discard_granularity; |
133 | unsigned int discard_alignment; | |
0a8704a5 | 134 | unsigned int feature_persistent:1; |
402b27f9 | 135 | unsigned int max_indirect_segments; |
1d78d705 | 136 | int is_ready; |
9f27ee59 JF |
137 | }; |
138 | ||
0e345826 JB |
139 | static unsigned int nr_minors; |
140 | static unsigned long *minors; | |
141 | static DEFINE_SPINLOCK(minor_lock); | |
142 | ||
9f27ee59 JF |
143 | #define MAXIMUM_OUTSTANDING_BLOCK_REQS \ |
144 | (BLKIF_MAX_SEGMENTS_PER_REQUEST * BLK_RING_SIZE) | |
145 | #define GRANT_INVALID_REF 0 | |
146 | ||
147 | #define PARTS_PER_DISK 16 | |
9246b5f0 | 148 | #define PARTS_PER_EXT_DISK 256 |
9f27ee59 JF |
149 | |
150 | #define BLKIF_MAJOR(dev) ((dev)>>8) | |
151 | #define BLKIF_MINOR(dev) ((dev) & 0xff) | |
152 | ||
9246b5f0 CL |
153 | #define EXT_SHIFT 28 |
154 | #define EXTENDED (1<<EXT_SHIFT) | |
155 | #define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED)) | |
156 | #define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED)) | |
c80a4209 SS |
157 | #define EMULATED_HD_DISK_MINOR_OFFSET (0) |
158 | #define EMULATED_HD_DISK_NAME_OFFSET (EMULATED_HD_DISK_MINOR_OFFSET / 256) | |
196cfe2a SB |
159 | #define EMULATED_SD_DISK_MINOR_OFFSET (0) |
160 | #define EMULATED_SD_DISK_NAME_OFFSET (EMULATED_SD_DISK_MINOR_OFFSET / 256) | |
9f27ee59 | 161 | |
9246b5f0 | 162 | #define DEV_NAME "xvd" /* name in /dev */ |
9f27ee59 | 163 | |
402b27f9 | 164 | #define SEGS_PER_INDIRECT_FRAME \ |
80bfa2f6 | 165 | (PAGE_SIZE/sizeof(struct blkif_request_segment)) |
402b27f9 RPM |
166 | #define INDIRECT_GREFS(_segs) \ |
167 | ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME) | |
168 | ||
169 | static int blkfront_setup_indirect(struct blkfront_info *info); | |
170 | ||
9f27ee59 JF |
171 | static int get_id_from_freelist(struct blkfront_info *info) |
172 | { | |
173 | unsigned long free = info->shadow_free; | |
b9ed7252 | 174 | BUG_ON(free >= BLK_RING_SIZE); |
97e36834 KRW |
175 | info->shadow_free = info->shadow[free].req.u.rw.id; |
176 | info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */ | |
9f27ee59 JF |
177 | return free; |
178 | } | |
179 | ||
6878c32e | 180 | static int add_id_to_freelist(struct blkfront_info *info, |
9f27ee59 JF |
181 | unsigned long id) |
182 | { | |
6878c32e KRW |
183 | if (info->shadow[id].req.u.rw.id != id) |
184 | return -EINVAL; | |
185 | if (info->shadow[id].request == NULL) | |
186 | return -EINVAL; | |
97e36834 | 187 | info->shadow[id].req.u.rw.id = info->shadow_free; |
a945b980 | 188 | info->shadow[id].request = NULL; |
9f27ee59 | 189 | info->shadow_free = id; |
6878c32e | 190 | return 0; |
9f27ee59 JF |
191 | } |
192 | ||
9c1e050c RPM |
193 | static int fill_grant_buffer(struct blkfront_info *info, int num) |
194 | { | |
195 | struct page *granted_page; | |
196 | struct grant *gnt_list_entry, *n; | |
197 | int i = 0; | |
198 | ||
199 | while(i < num) { | |
200 | gnt_list_entry = kzalloc(sizeof(struct grant), GFP_NOIO); | |
201 | if (!gnt_list_entry) | |
202 | goto out_of_memory; | |
203 | ||
bfe11d6d RPM |
204 | if (info->feature_persistent) { |
205 | granted_page = alloc_page(GFP_NOIO); | |
206 | if (!granted_page) { | |
207 | kfree(gnt_list_entry); | |
208 | goto out_of_memory; | |
209 | } | |
210 | gnt_list_entry->pfn = page_to_pfn(granted_page); | |
9c1e050c RPM |
211 | } |
212 | ||
9c1e050c | 213 | gnt_list_entry->gref = GRANT_INVALID_REF; |
bfe11d6d | 214 | list_add(&gnt_list_entry->node, &info->grants); |
9c1e050c RPM |
215 | i++; |
216 | } | |
217 | ||
218 | return 0; | |
219 | ||
220 | out_of_memory: | |
221 | list_for_each_entry_safe(gnt_list_entry, n, | |
bfe11d6d | 222 | &info->grants, node) { |
9c1e050c | 223 | list_del(&gnt_list_entry->node); |
bfe11d6d RPM |
224 | if (info->feature_persistent) |
225 | __free_page(pfn_to_page(gnt_list_entry->pfn)); | |
9c1e050c RPM |
226 | kfree(gnt_list_entry); |
227 | i--; | |
228 | } | |
229 | BUG_ON(i != 0); | |
230 | return -ENOMEM; | |
231 | } | |
232 | ||
233 | static struct grant *get_grant(grant_ref_t *gref_head, | |
bfe11d6d | 234 | unsigned long pfn, |
9c1e050c RPM |
235 | struct blkfront_info *info) |
236 | { | |
237 | struct grant *gnt_list_entry; | |
238 | unsigned long buffer_mfn; | |
239 | ||
bfe11d6d RPM |
240 | BUG_ON(list_empty(&info->grants)); |
241 | gnt_list_entry = list_first_entry(&info->grants, struct grant, | |
9c1e050c RPM |
242 | node); |
243 | list_del(&gnt_list_entry->node); | |
244 | ||
245 | if (gnt_list_entry->gref != GRANT_INVALID_REF) { | |
246 | info->persistent_gnts_c--; | |
247 | return gnt_list_entry; | |
248 | } | |
249 | ||
250 | /* Assign a gref to this page */ | |
251 | gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); | |
252 | BUG_ON(gnt_list_entry->gref == -ENOSPC); | |
bfe11d6d RPM |
253 | if (!info->feature_persistent) { |
254 | BUG_ON(!pfn); | |
255 | gnt_list_entry->pfn = pfn; | |
256 | } | |
9c1e050c RPM |
257 | buffer_mfn = pfn_to_mfn(gnt_list_entry->pfn); |
258 | gnttab_grant_foreign_access_ref(gnt_list_entry->gref, | |
259 | info->xbdev->otherend_id, | |
260 | buffer_mfn, 0); | |
261 | return gnt_list_entry; | |
262 | } | |
263 | ||
6878c32e KRW |
264 | static const char *op_name(int op) |
265 | { | |
266 | static const char *const names[] = { | |
267 | [BLKIF_OP_READ] = "read", | |
268 | [BLKIF_OP_WRITE] = "write", | |
269 | [BLKIF_OP_WRITE_BARRIER] = "barrier", | |
270 | [BLKIF_OP_FLUSH_DISKCACHE] = "flush", | |
271 | [BLKIF_OP_DISCARD] = "discard" }; | |
272 | ||
273 | if (op < 0 || op >= ARRAY_SIZE(names)) | |
274 | return "unknown"; | |
275 | ||
276 | if (!names[op]) | |
277 | return "reserved"; | |
278 | ||
279 | return names[op]; | |
280 | } | |
0e345826 JB |
281 | static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) |
282 | { | |
283 | unsigned int end = minor + nr; | |
284 | int rc; | |
285 | ||
286 | if (end > nr_minors) { | |
287 | unsigned long *bitmap, *old; | |
288 | ||
f094148a | 289 | bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap), |
0e345826 JB |
290 | GFP_KERNEL); |
291 | if (bitmap == NULL) | |
292 | return -ENOMEM; | |
293 | ||
294 | spin_lock(&minor_lock); | |
295 | if (end > nr_minors) { | |
296 | old = minors; | |
297 | memcpy(bitmap, minors, | |
298 | BITS_TO_LONGS(nr_minors) * sizeof(*bitmap)); | |
299 | minors = bitmap; | |
300 | nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG; | |
301 | } else | |
302 | old = bitmap; | |
303 | spin_unlock(&minor_lock); | |
304 | kfree(old); | |
305 | } | |
306 | ||
307 | spin_lock(&minor_lock); | |
308 | if (find_next_bit(minors, end, minor) >= end) { | |
34ae2e47 | 309 | bitmap_set(minors, minor, nr); |
0e345826 JB |
310 | rc = 0; |
311 | } else | |
312 | rc = -EBUSY; | |
313 | spin_unlock(&minor_lock); | |
314 | ||
315 | return rc; | |
316 | } | |
317 | ||
318 | static void xlbd_release_minors(unsigned int minor, unsigned int nr) | |
319 | { | |
320 | unsigned int end = minor + nr; | |
321 | ||
322 | BUG_ON(end > nr_minors); | |
323 | spin_lock(&minor_lock); | |
34ae2e47 | 324 | bitmap_clear(minors, minor, nr); |
0e345826 JB |
325 | spin_unlock(&minor_lock); |
326 | } | |
327 | ||
9f27ee59 JF |
328 | static void blkif_restart_queue_callback(void *arg) |
329 | { | |
330 | struct blkfront_info *info = (struct blkfront_info *)arg; | |
331 | schedule_work(&info->work); | |
332 | } | |
333 | ||
afe42d7d | 334 | static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg) |
597592d9 IC |
335 | { |
336 | /* We don't have real geometry info, but let's at least return | |
337 | values consistent with the size of the device */ | |
338 | sector_t nsect = get_capacity(bd->bd_disk); | |
339 | sector_t cylinders = nsect; | |
340 | ||
341 | hg->heads = 0xff; | |
342 | hg->sectors = 0x3f; | |
343 | sector_div(cylinders, hg->heads * hg->sectors); | |
344 | hg->cylinders = cylinders; | |
345 | if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect) | |
346 | hg->cylinders = 0xffff; | |
347 | return 0; | |
348 | } | |
349 | ||
a63c848b | 350 | static int blkif_ioctl(struct block_device *bdev, fmode_t mode, |
62aa0054 | 351 | unsigned command, unsigned long argument) |
440a01a7 | 352 | { |
a63c848b | 353 | struct blkfront_info *info = bdev->bd_disk->private_data; |
440a01a7 CL |
354 | int i; |
355 | ||
356 | dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n", | |
357 | command, (long)argument); | |
358 | ||
359 | switch (command) { | |
360 | case CDROMMULTISESSION: | |
361 | dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n"); | |
362 | for (i = 0; i < sizeof(struct cdrom_multisession); i++) | |
363 | if (put_user(0, (char __user *)(argument + i))) | |
364 | return -EFAULT; | |
365 | return 0; | |
366 | ||
367 | case CDROM_GET_CAPABILITY: { | |
368 | struct gendisk *gd = info->gd; | |
369 | if (gd->flags & GENHD_FL_CD) | |
370 | return 0; | |
371 | return -EINVAL; | |
372 | } | |
373 | ||
374 | default: | |
375 | /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n", | |
376 | command);*/ | |
377 | return -EINVAL; /* same return as native Linux */ | |
378 | } | |
379 | ||
380 | return 0; | |
381 | } | |
382 | ||
9f27ee59 | 383 | /* |
c64e38ea | 384 | * Generate a Xen blkfront IO request from a blk layer request. Reads |
edf6ef59 | 385 | * and writes are handled as expected. |
9f27ee59 | 386 | * |
c64e38ea | 387 | * @req: a request struct |
9f27ee59 JF |
388 | */ |
389 | static int blkif_queue_request(struct request *req) | |
390 | { | |
391 | struct blkfront_info *info = req->rq_disk->private_data; | |
9f27ee59 | 392 | struct blkif_request *ring_req; |
9f27ee59 JF |
393 | unsigned long id; |
394 | unsigned int fsect, lsect; | |
402b27f9 | 395 | int i, ref, n; |
80bfa2f6 | 396 | struct blkif_request_segment *segments = NULL; |
0a8704a5 RPM |
397 | |
398 | /* | |
399 | * Used to store if we are able to queue the request by just using | |
400 | * existing persistent grants, or if we have to get new grants, | |
401 | * as there are not sufficiently many free. | |
402 | */ | |
403 | bool new_persistent_gnts; | |
9f27ee59 | 404 | grant_ref_t gref_head; |
0a8704a5 | 405 | struct grant *gnt_list_entry = NULL; |
9e973e64 | 406 | struct scatterlist *sg; |
402b27f9 | 407 | int nseg, max_grefs; |
9f27ee59 JF |
408 | |
409 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) | |
410 | return 1; | |
411 | ||
c47206e2 RPM |
412 | max_grefs = req->nr_phys_segments; |
413 | if (max_grefs > BLKIF_MAX_SEGMENTS_PER_REQUEST) | |
414 | /* | |
415 | * If we are using indirect segments we need to account | |
416 | * for the indirect grefs used in the request. | |
417 | */ | |
418 | max_grefs += INDIRECT_GREFS(req->nr_phys_segments); | |
402b27f9 RPM |
419 | |
420 | /* Check if we have enough grants to allocate a requests */ | |
421 | if (info->persistent_gnts_c < max_grefs) { | |
0a8704a5 RPM |
422 | new_persistent_gnts = 1; |
423 | if (gnttab_alloc_grant_references( | |
402b27f9 | 424 | max_grefs - info->persistent_gnts_c, |
0a8704a5 RPM |
425 | &gref_head) < 0) { |
426 | gnttab_request_free_callback( | |
427 | &info->callback, | |
428 | blkif_restart_queue_callback, | |
429 | info, | |
402b27f9 | 430 | max_grefs); |
0a8704a5 RPM |
431 | return 1; |
432 | } | |
433 | } else | |
434 | new_persistent_gnts = 0; | |
9f27ee59 JF |
435 | |
436 | /* Fill out a communications ring structure. */ | |
437 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
438 | id = get_id_from_freelist(info); | |
a945b980 | 439 | info->shadow[id].request = req; |
9f27ee59 | 440 | |
5ea42986 | 441 | if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE))) { |
ed30bf31 | 442 | ring_req->operation = BLKIF_OP_DISCARD; |
ed30bf31 | 443 | ring_req->u.discard.nr_sectors = blk_rq_sectors(req); |
402b27f9 RPM |
444 | ring_req->u.discard.id = id; |
445 | ring_req->u.discard.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
5ea42986 KRW |
446 | if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard) |
447 | ring_req->u.discard.flag = BLKIF_DISCARD_SECURE; | |
448 | else | |
449 | ring_req->u.discard.flag = 0; | |
ed30bf31 | 450 | } else { |
402b27f9 RPM |
451 | BUG_ON(info->max_indirect_segments == 0 && |
452 | req->nr_phys_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
453 | BUG_ON(info->max_indirect_segments && | |
454 | req->nr_phys_segments > info->max_indirect_segments); | |
b7649158 | 455 | nseg = blk_rq_map_sg(req->q, req, info->shadow[id].sg); |
402b27f9 RPM |
456 | ring_req->u.rw.id = id; |
457 | if (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST) { | |
458 | /* | |
459 | * The indirect operation can only be a BLKIF_OP_READ or | |
460 | * BLKIF_OP_WRITE | |
461 | */ | |
462 | BUG_ON(req->cmd_flags & (REQ_FLUSH | REQ_FUA)); | |
463 | ring_req->operation = BLKIF_OP_INDIRECT; | |
464 | ring_req->u.indirect.indirect_op = rq_data_dir(req) ? | |
465 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
466 | ring_req->u.indirect.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
467 | ring_req->u.indirect.handle = info->handle; | |
468 | ring_req->u.indirect.nr_segments = nseg; | |
469 | } else { | |
470 | ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
471 | ring_req->u.rw.handle = info->handle; | |
472 | ring_req->operation = rq_data_dir(req) ? | |
473 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
474 | if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) { | |
475 | /* | |
476 | * Ideally we can do an unordered flush-to-disk. In case the | |
477 | * backend onlysupports barriers, use that. A barrier request | |
478 | * a superset of FUA, so we can implement it the same | |
479 | * way. (It's also a FLUSH+FUA, since it is | |
480 | * guaranteed ordered WRT previous writes.) | |
481 | */ | |
482 | ring_req->operation = info->flush_op; | |
483 | } | |
484 | ring_req->u.rw.nr_segments = nseg; | |
485 | } | |
b7649158 | 486 | for_each_sg(info->shadow[id].sg, sg, nseg, i) { |
ed30bf31 LD |
487 | fsect = sg->offset >> 9; |
488 | lsect = fsect + (sg->length >> 9) - 1; | |
6c92e699 | 489 | |
402b27f9 RPM |
490 | if ((ring_req->operation == BLKIF_OP_INDIRECT) && |
491 | (i % SEGS_PER_INDIRECT_FRAME == 0)) { | |
427bfe07 | 492 | unsigned long uninitialized_var(pfn); |
bfe11d6d | 493 | |
402b27f9 RPM |
494 | if (segments) |
495 | kunmap_atomic(segments); | |
496 | ||
497 | n = i / SEGS_PER_INDIRECT_FRAME; | |
bfe11d6d RPM |
498 | if (!info->feature_persistent) { |
499 | struct page *indirect_page; | |
500 | ||
501 | /* Fetch a pre-allocated page to use for indirect grefs */ | |
502 | BUG_ON(list_empty(&info->indirect_pages)); | |
503 | indirect_page = list_first_entry(&info->indirect_pages, | |
504 | struct page, lru); | |
505 | list_del(&indirect_page->lru); | |
506 | pfn = page_to_pfn(indirect_page); | |
507 | } | |
508 | gnt_list_entry = get_grant(&gref_head, pfn, info); | |
402b27f9 RPM |
509 | info->shadow[id].indirect_grants[n] = gnt_list_entry; |
510 | segments = kmap_atomic(pfn_to_page(gnt_list_entry->pfn)); | |
511 | ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref; | |
512 | } | |
513 | ||
bfe11d6d | 514 | gnt_list_entry = get_grant(&gref_head, page_to_pfn(sg_page(sg)), info); |
9c1e050c | 515 | ref = gnt_list_entry->gref; |
0a8704a5 RPM |
516 | |
517 | info->shadow[id].grants_used[i] = gnt_list_entry; | |
518 | ||
bfe11d6d | 519 | if (rq_data_dir(req) && info->feature_persistent) { |
0a8704a5 RPM |
520 | char *bvec_data; |
521 | void *shared_data; | |
522 | ||
523 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); | |
524 | ||
402b27f9 | 525 | shared_data = kmap_atomic(pfn_to_page(gnt_list_entry->pfn)); |
0a8704a5 RPM |
526 | bvec_data = kmap_atomic(sg_page(sg)); |
527 | ||
528 | /* | |
529 | * this does not wipe data stored outside the | |
530 | * range sg->offset..sg->offset+sg->length. | |
531 | * Therefore, blkback *could* see data from | |
532 | * previous requests. This is OK as long as | |
533 | * persistent grants are shared with just one | |
534 | * domain. It may need refactoring if this | |
535 | * changes | |
536 | */ | |
537 | memcpy(shared_data + sg->offset, | |
538 | bvec_data + sg->offset, | |
539 | sg->length); | |
540 | ||
541 | kunmap_atomic(bvec_data); | |
542 | kunmap_atomic(shared_data); | |
543 | } | |
402b27f9 RPM |
544 | if (ring_req->operation != BLKIF_OP_INDIRECT) { |
545 | ring_req->u.rw.seg[i] = | |
546 | (struct blkif_request_segment) { | |
547 | .gref = ref, | |
548 | .first_sect = fsect, | |
549 | .last_sect = lsect }; | |
550 | } else { | |
551 | n = i % SEGS_PER_INDIRECT_FRAME; | |
552 | segments[n] = | |
80bfa2f6 | 553 | (struct blkif_request_segment) { |
402b27f9 RPM |
554 | .gref = ref, |
555 | .first_sect = fsect, | |
556 | .last_sect = lsect }; | |
557 | } | |
ed30bf31 | 558 | } |
402b27f9 RPM |
559 | if (segments) |
560 | kunmap_atomic(segments); | |
9f27ee59 JF |
561 | } |
562 | ||
563 | info->ring.req_prod_pvt++; | |
564 | ||
565 | /* Keep a private copy so we can reissue requests when recovering. */ | |
566 | info->shadow[id].req = *ring_req; | |
567 | ||
0a8704a5 RPM |
568 | if (new_persistent_gnts) |
569 | gnttab_free_grant_references(gref_head); | |
9f27ee59 JF |
570 | |
571 | return 0; | |
572 | } | |
573 | ||
574 | ||
575 | static inline void flush_requests(struct blkfront_info *info) | |
576 | { | |
577 | int notify; | |
578 | ||
579 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify); | |
580 | ||
581 | if (notify) | |
582 | notify_remote_via_irq(info->irq); | |
583 | } | |
584 | ||
585 | /* | |
586 | * do_blkif_request | |
587 | * read a block; request is in a request queue | |
588 | */ | |
165125e1 | 589 | static void do_blkif_request(struct request_queue *rq) |
9f27ee59 JF |
590 | { |
591 | struct blkfront_info *info = NULL; | |
592 | struct request *req; | |
593 | int queued; | |
594 | ||
595 | pr_debug("Entered do_blkif_request\n"); | |
596 | ||
597 | queued = 0; | |
598 | ||
9934c8c0 | 599 | while ((req = blk_peek_request(rq)) != NULL) { |
9f27ee59 | 600 | info = req->rq_disk->private_data; |
9f27ee59 JF |
601 | |
602 | if (RING_FULL(&info->ring)) | |
603 | goto wait; | |
604 | ||
9934c8c0 | 605 | blk_start_request(req); |
296b2f6a | 606 | |
d11e6158 KRW |
607 | if ((req->cmd_type != REQ_TYPE_FS) || |
608 | ((req->cmd_flags & (REQ_FLUSH | REQ_FUA)) && | |
609 | !info->flush_op)) { | |
296b2f6a TH |
610 | __blk_end_request_all(req, -EIO); |
611 | continue; | |
612 | } | |
613 | ||
9f27ee59 | 614 | pr_debug("do_blk_req %p: cmd %p, sec %lx, " |
83096ebf TH |
615 | "(%u/%u) buffer:%p [%s]\n", |
616 | req, req->cmd, (unsigned long)blk_rq_pos(req), | |
617 | blk_rq_cur_sectors(req), blk_rq_sectors(req), | |
618 | req->buffer, rq_data_dir(req) ? "write" : "read"); | |
9f27ee59 | 619 | |
9f27ee59 JF |
620 | if (blkif_queue_request(req)) { |
621 | blk_requeue_request(rq, req); | |
622 | wait: | |
623 | /* Avoid pointless unplugs. */ | |
624 | blk_stop_queue(rq); | |
625 | break; | |
626 | } | |
627 | ||
628 | queued++; | |
629 | } | |
630 | ||
631 | if (queued != 0) | |
632 | flush_requests(info); | |
633 | } | |
634 | ||
402b27f9 | 635 | static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, |
7c4d7d71 | 636 | unsigned int physical_sector_size, |
402b27f9 | 637 | unsigned int segments) |
9f27ee59 | 638 | { |
165125e1 | 639 | struct request_queue *rq; |
ed30bf31 | 640 | struct blkfront_info *info = gd->private_data; |
9f27ee59 | 641 | |
3467811e | 642 | rq = blk_init_queue(do_blkif_request, &info->io_lock); |
9f27ee59 JF |
643 | if (rq == NULL) |
644 | return -1; | |
645 | ||
66d352e1 | 646 | queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); |
9f27ee59 | 647 | |
ed30bf31 LD |
648 | if (info->feature_discard) { |
649 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, rq); | |
650 | blk_queue_max_discard_sectors(rq, get_capacity(gd)); | |
651 | rq->limits.discard_granularity = info->discard_granularity; | |
652 | rq->limits.discard_alignment = info->discard_alignment; | |
5ea42986 KRW |
653 | if (info->feature_secdiscard) |
654 | queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, rq); | |
ed30bf31 LD |
655 | } |
656 | ||
9f27ee59 | 657 | /* Hard sector size and max sectors impersonate the equiv. hardware. */ |
e1defc4f | 658 | blk_queue_logical_block_size(rq, sector_size); |
7c4d7d71 | 659 | blk_queue_physical_block_size(rq, physical_sector_size); |
294caaf2 | 660 | blk_queue_max_hw_sectors(rq, (segments * PAGE_SIZE) / 512); |
9f27ee59 JF |
661 | |
662 | /* Each segment in a request is up to an aligned page in size. */ | |
663 | blk_queue_segment_boundary(rq, PAGE_SIZE - 1); | |
664 | blk_queue_max_segment_size(rq, PAGE_SIZE); | |
665 | ||
666 | /* Ensure a merged request will fit in a single I/O ring slot. */ | |
402b27f9 | 667 | blk_queue_max_segments(rq, segments); |
9f27ee59 JF |
668 | |
669 | /* Make sure buffer addresses are sector-aligned. */ | |
670 | blk_queue_dma_alignment(rq, 511); | |
671 | ||
1c91fe1a IC |
672 | /* Make sure we don't use bounce buffers. */ |
673 | blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY); | |
674 | ||
9f27ee59 JF |
675 | gd->queue = rq; |
676 | ||
677 | return 0; | |
678 | } | |
679 | ||
680 | ||
4913efe4 | 681 | static void xlvbd_flush(struct blkfront_info *info) |
9f27ee59 | 682 | { |
4913efe4 | 683 | blk_queue_flush(info->rq, info->feature_flush); |
402b27f9 | 684 | printk(KERN_INFO "blkfront: %s: %s: %s %s %s %s %s\n", |
4913efe4 | 685 | info->gd->disk_name, |
edf6ef59 KRW |
686 | info->flush_op == BLKIF_OP_WRITE_BARRIER ? |
687 | "barrier" : (info->flush_op == BLKIF_OP_FLUSH_DISKCACHE ? | |
688 | "flush diskcache" : "barrier or flush"), | |
402b27f9 RPM |
689 | info->feature_flush ? "enabled;" : "disabled;", |
690 | "persistent grants:", | |
691 | info->feature_persistent ? "enabled;" : "disabled;", | |
692 | "indirect descriptors:", | |
693 | info->max_indirect_segments ? "enabled;" : "disabled;"); | |
9f27ee59 JF |
694 | } |
695 | ||
c80a4209 SS |
696 | static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) |
697 | { | |
698 | int major; | |
699 | major = BLKIF_MAJOR(vdevice); | |
700 | *minor = BLKIF_MINOR(vdevice); | |
701 | switch (major) { | |
702 | case XEN_IDE0_MAJOR: | |
703 | *offset = (*minor / 64) + EMULATED_HD_DISK_NAME_OFFSET; | |
704 | *minor = ((*minor / 64) * PARTS_PER_DISK) + | |
705 | EMULATED_HD_DISK_MINOR_OFFSET; | |
706 | break; | |
707 | case XEN_IDE1_MAJOR: | |
708 | *offset = (*minor / 64) + 2 + EMULATED_HD_DISK_NAME_OFFSET; | |
709 | *minor = (((*minor / 64) + 2) * PARTS_PER_DISK) + | |
710 | EMULATED_HD_DISK_MINOR_OFFSET; | |
711 | break; | |
712 | case XEN_SCSI_DISK0_MAJOR: | |
713 | *offset = (*minor / PARTS_PER_DISK) + EMULATED_SD_DISK_NAME_OFFSET; | |
714 | *minor = *minor + EMULATED_SD_DISK_MINOR_OFFSET; | |
715 | break; | |
716 | case XEN_SCSI_DISK1_MAJOR: | |
717 | case XEN_SCSI_DISK2_MAJOR: | |
718 | case XEN_SCSI_DISK3_MAJOR: | |
719 | case XEN_SCSI_DISK4_MAJOR: | |
720 | case XEN_SCSI_DISK5_MAJOR: | |
721 | case XEN_SCSI_DISK6_MAJOR: | |
722 | case XEN_SCSI_DISK7_MAJOR: | |
723 | *offset = (*minor / PARTS_PER_DISK) + | |
724 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16) + | |
725 | EMULATED_SD_DISK_NAME_OFFSET; | |
726 | *minor = *minor + | |
727 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16 * PARTS_PER_DISK) + | |
728 | EMULATED_SD_DISK_MINOR_OFFSET; | |
729 | break; | |
730 | case XEN_SCSI_DISK8_MAJOR: | |
731 | case XEN_SCSI_DISK9_MAJOR: | |
732 | case XEN_SCSI_DISK10_MAJOR: | |
733 | case XEN_SCSI_DISK11_MAJOR: | |
734 | case XEN_SCSI_DISK12_MAJOR: | |
735 | case XEN_SCSI_DISK13_MAJOR: | |
736 | case XEN_SCSI_DISK14_MAJOR: | |
737 | case XEN_SCSI_DISK15_MAJOR: | |
738 | *offset = (*minor / PARTS_PER_DISK) + | |
739 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16) + | |
740 | EMULATED_SD_DISK_NAME_OFFSET; | |
741 | *minor = *minor + | |
742 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16 * PARTS_PER_DISK) + | |
743 | EMULATED_SD_DISK_MINOR_OFFSET; | |
744 | break; | |
745 | case XENVBD_MAJOR: | |
746 | *offset = *minor / PARTS_PER_DISK; | |
747 | break; | |
748 | default: | |
749 | printk(KERN_WARNING "blkfront: your disk configuration is " | |
750 | "incorrect, please use an xvd device instead\n"); | |
751 | return -ENODEV; | |
752 | } | |
753 | return 0; | |
754 | } | |
9f27ee59 | 755 | |
e77c78c0 JB |
756 | static char *encode_disk_name(char *ptr, unsigned int n) |
757 | { | |
758 | if (n >= 26) | |
759 | ptr = encode_disk_name(ptr, n / 26 - 1); | |
760 | *ptr = 'a' + n % 26; | |
761 | return ptr + 1; | |
762 | } | |
763 | ||
9246b5f0 CL |
764 | static int xlvbd_alloc_gendisk(blkif_sector_t capacity, |
765 | struct blkfront_info *info, | |
7c4d7d71 SB |
766 | u16 vdisk_info, u16 sector_size, |
767 | unsigned int physical_sector_size) | |
9f27ee59 JF |
768 | { |
769 | struct gendisk *gd; | |
770 | int nr_minors = 1; | |
c80a4209 | 771 | int err; |
9246b5f0 CL |
772 | unsigned int offset; |
773 | int minor; | |
774 | int nr_parts; | |
e77c78c0 | 775 | char *ptr; |
9f27ee59 JF |
776 | |
777 | BUG_ON(info->gd != NULL); | |
778 | BUG_ON(info->rq != NULL); | |
779 | ||
9246b5f0 CL |
780 | if ((info->vdevice>>EXT_SHIFT) > 1) { |
781 | /* this is above the extended range; something is wrong */ | |
782 | printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice); | |
783 | return -ENODEV; | |
784 | } | |
785 | ||
786 | if (!VDEV_IS_EXTENDED(info->vdevice)) { | |
c80a4209 SS |
787 | err = xen_translate_vdev(info->vdevice, &minor, &offset); |
788 | if (err) | |
789 | return err; | |
790 | nr_parts = PARTS_PER_DISK; | |
9246b5f0 CL |
791 | } else { |
792 | minor = BLKIF_MINOR_EXT(info->vdevice); | |
793 | nr_parts = PARTS_PER_EXT_DISK; | |
c80a4209 | 794 | offset = minor / nr_parts; |
89153b5c | 795 | if (xen_hvm_domain() && offset < EMULATED_HD_DISK_NAME_OFFSET + 4) |
c80a4209 SS |
796 | printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with " |
797 | "emulated IDE disks,\n\t choose an xvd device name" | |
798 | "from xvde on\n", info->vdevice); | |
9246b5f0 | 799 | } |
e77c78c0 JB |
800 | if (minor >> MINORBITS) { |
801 | pr_warn("blkfront: %#x's minor (%#x) out of range; ignoring\n", | |
802 | info->vdevice, minor); | |
803 | return -ENODEV; | |
804 | } | |
9246b5f0 CL |
805 | |
806 | if ((minor % nr_parts) == 0) | |
807 | nr_minors = nr_parts; | |
9f27ee59 | 808 | |
0e345826 JB |
809 | err = xlbd_reserve_minors(minor, nr_minors); |
810 | if (err) | |
811 | goto out; | |
812 | err = -ENODEV; | |
813 | ||
9f27ee59 JF |
814 | gd = alloc_disk(nr_minors); |
815 | if (gd == NULL) | |
0e345826 | 816 | goto release; |
9f27ee59 | 817 | |
e77c78c0 JB |
818 | strcpy(gd->disk_name, DEV_NAME); |
819 | ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset); | |
820 | BUG_ON(ptr >= gd->disk_name + DISK_NAME_LEN); | |
821 | if (nr_minors > 1) | |
822 | *ptr = 0; | |
823 | else | |
824 | snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr, | |
825 | "%d", minor & (nr_parts - 1)); | |
9f27ee59 JF |
826 | |
827 | gd->major = XENVBD_MAJOR; | |
828 | gd->first_minor = minor; | |
829 | gd->fops = &xlvbd_block_fops; | |
830 | gd->private_data = info; | |
831 | gd->driverfs_dev = &(info->xbdev->dev); | |
832 | set_capacity(gd, capacity); | |
833 | ||
7c4d7d71 | 834 | if (xlvbd_init_blk_queue(gd, sector_size, physical_sector_size, |
402b27f9 RPM |
835 | info->max_indirect_segments ? : |
836 | BLKIF_MAX_SEGMENTS_PER_REQUEST)) { | |
9f27ee59 | 837 | del_gendisk(gd); |
0e345826 | 838 | goto release; |
9f27ee59 JF |
839 | } |
840 | ||
841 | info->rq = gd->queue; | |
842 | info->gd = gd; | |
843 | ||
4913efe4 | 844 | xlvbd_flush(info); |
9f27ee59 JF |
845 | |
846 | if (vdisk_info & VDISK_READONLY) | |
847 | set_disk_ro(gd, 1); | |
848 | ||
849 | if (vdisk_info & VDISK_REMOVABLE) | |
850 | gd->flags |= GENHD_FL_REMOVABLE; | |
851 | ||
852 | if (vdisk_info & VDISK_CDROM) | |
853 | gd->flags |= GENHD_FL_CD; | |
854 | ||
855 | return 0; | |
856 | ||
0e345826 JB |
857 | release: |
858 | xlbd_release_minors(minor, nr_minors); | |
9f27ee59 JF |
859 | out: |
860 | return err; | |
861 | } | |
862 | ||
a66b5aeb DS |
863 | static void xlvbd_release_gendisk(struct blkfront_info *info) |
864 | { | |
865 | unsigned int minor, nr_minors; | |
866 | unsigned long flags; | |
867 | ||
868 | if (info->rq == NULL) | |
869 | return; | |
870 | ||
3467811e | 871 | spin_lock_irqsave(&info->io_lock, flags); |
a66b5aeb DS |
872 | |
873 | /* No more blkif_request(). */ | |
874 | blk_stop_queue(info->rq); | |
875 | ||
876 | /* No more gnttab callback work. */ | |
877 | gnttab_cancel_free_callback(&info->callback); | |
3467811e | 878 | spin_unlock_irqrestore(&info->io_lock, flags); |
a66b5aeb DS |
879 | |
880 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 881 | flush_work(&info->work); |
a66b5aeb DS |
882 | |
883 | del_gendisk(info->gd); | |
884 | ||
885 | minor = info->gd->first_minor; | |
886 | nr_minors = info->gd->minors; | |
887 | xlbd_release_minors(minor, nr_minors); | |
888 | ||
889 | blk_cleanup_queue(info->rq); | |
890 | info->rq = NULL; | |
891 | ||
892 | put_disk(info->gd); | |
893 | info->gd = NULL; | |
894 | } | |
895 | ||
9f27ee59 JF |
896 | static void kick_pending_request_queues(struct blkfront_info *info) |
897 | { | |
898 | if (!RING_FULL(&info->ring)) { | |
899 | /* Re-enable calldowns. */ | |
900 | blk_start_queue(info->rq); | |
901 | /* Kick things off immediately. */ | |
902 | do_blkif_request(info->rq); | |
903 | } | |
904 | } | |
905 | ||
906 | static void blkif_restart_queue(struct work_struct *work) | |
907 | { | |
908 | struct blkfront_info *info = container_of(work, struct blkfront_info, work); | |
909 | ||
3467811e | 910 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
911 | if (info->connected == BLKIF_STATE_CONNECTED) |
912 | kick_pending_request_queues(info); | |
3467811e | 913 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
914 | } |
915 | ||
916 | static void blkif_free(struct blkfront_info *info, int suspend) | |
917 | { | |
155b7edb RPM |
918 | struct grant *persistent_gnt; |
919 | struct grant *n; | |
402b27f9 | 920 | int i, j, segs; |
0a8704a5 | 921 | |
9f27ee59 | 922 | /* Prevent new requests being issued until we fix things up. */ |
3467811e | 923 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
924 | info->connected = suspend ? |
925 | BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; | |
926 | /* No more blkif_request(). */ | |
927 | if (info->rq) | |
928 | blk_stop_queue(info->rq); | |
0a8704a5 RPM |
929 | |
930 | /* Remove all persistent grants */ | |
bfe11d6d | 931 | if (!list_empty(&info->grants)) { |
155b7edb | 932 | list_for_each_entry_safe(persistent_gnt, n, |
bfe11d6d | 933 | &info->grants, node) { |
155b7edb | 934 | list_del(&persistent_gnt->node); |
9c1e050c RPM |
935 | if (persistent_gnt->gref != GRANT_INVALID_REF) { |
936 | gnttab_end_foreign_access(persistent_gnt->gref, | |
937 | 0, 0UL); | |
938 | info->persistent_gnts_c--; | |
939 | } | |
bfe11d6d RPM |
940 | if (info->feature_persistent) |
941 | __free_page(pfn_to_page(persistent_gnt->pfn)); | |
155b7edb | 942 | kfree(persistent_gnt); |
0a8704a5 | 943 | } |
0a8704a5 | 944 | } |
9c1e050c | 945 | BUG_ON(info->persistent_gnts_c != 0); |
0a8704a5 | 946 | |
bfe11d6d RPM |
947 | /* |
948 | * Remove indirect pages, this only happens when using indirect | |
949 | * descriptors but not persistent grants | |
950 | */ | |
951 | if (!list_empty(&info->indirect_pages)) { | |
952 | struct page *indirect_page, *n; | |
953 | ||
954 | BUG_ON(info->feature_persistent); | |
955 | list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) { | |
956 | list_del(&indirect_page->lru); | |
957 | __free_page(indirect_page); | |
958 | } | |
959 | } | |
960 | ||
402b27f9 RPM |
961 | for (i = 0; i < BLK_RING_SIZE; i++) { |
962 | /* | |
963 | * Clear persistent grants present in requests already | |
964 | * on the shared ring | |
965 | */ | |
966 | if (!info->shadow[i].request) | |
967 | goto free_shadow; | |
968 | ||
969 | segs = info->shadow[i].req.operation == BLKIF_OP_INDIRECT ? | |
970 | info->shadow[i].req.u.indirect.nr_segments : | |
971 | info->shadow[i].req.u.rw.nr_segments; | |
972 | for (j = 0; j < segs; j++) { | |
973 | persistent_gnt = info->shadow[i].grants_used[j]; | |
974 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); | |
bfe11d6d RPM |
975 | if (info->feature_persistent) |
976 | __free_page(pfn_to_page(persistent_gnt->pfn)); | |
402b27f9 RPM |
977 | kfree(persistent_gnt); |
978 | } | |
979 | ||
980 | if (info->shadow[i].req.operation != BLKIF_OP_INDIRECT) | |
981 | /* | |
982 | * If this is not an indirect operation don't try to | |
983 | * free indirect segments | |
984 | */ | |
985 | goto free_shadow; | |
986 | ||
987 | for (j = 0; j < INDIRECT_GREFS(segs); j++) { | |
988 | persistent_gnt = info->shadow[i].indirect_grants[j]; | |
989 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); | |
990 | __free_page(pfn_to_page(persistent_gnt->pfn)); | |
991 | kfree(persistent_gnt); | |
992 | } | |
993 | ||
994 | free_shadow: | |
995 | kfree(info->shadow[i].grants_used); | |
996 | info->shadow[i].grants_used = NULL; | |
997 | kfree(info->shadow[i].indirect_grants); | |
998 | info->shadow[i].indirect_grants = NULL; | |
b7649158 RPM |
999 | kfree(info->shadow[i].sg); |
1000 | info->shadow[i].sg = NULL; | |
402b27f9 RPM |
1001 | } |
1002 | ||
9f27ee59 JF |
1003 | /* No more gnttab callback work. */ |
1004 | gnttab_cancel_free_callback(&info->callback); | |
3467811e | 1005 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1006 | |
1007 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 1008 | flush_work(&info->work); |
9f27ee59 JF |
1009 | |
1010 | /* Free resources associated with old device channel. */ | |
1011 | if (info->ring_ref != GRANT_INVALID_REF) { | |
1012 | gnttab_end_foreign_access(info->ring_ref, 0, | |
1013 | (unsigned long)info->ring.sring); | |
1014 | info->ring_ref = GRANT_INVALID_REF; | |
1015 | info->ring.sring = NULL; | |
1016 | } | |
1017 | if (info->irq) | |
1018 | unbind_from_irqhandler(info->irq, info); | |
1019 | info->evtchn = info->irq = 0; | |
1020 | ||
1021 | } | |
1022 | ||
0a8704a5 RPM |
1023 | static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info, |
1024 | struct blkif_response *bret) | |
9f27ee59 | 1025 | { |
d62f6918 | 1026 | int i = 0; |
b7649158 | 1027 | struct scatterlist *sg; |
0a8704a5 RPM |
1028 | char *bvec_data; |
1029 | void *shared_data; | |
402b27f9 RPM |
1030 | int nseg; |
1031 | ||
1032 | nseg = s->req.operation == BLKIF_OP_INDIRECT ? | |
1033 | s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments; | |
0a8704a5 | 1034 | |
bfe11d6d | 1035 | if (bret->operation == BLKIF_OP_READ && info->feature_persistent) { |
0a8704a5 RPM |
1036 | /* |
1037 | * Copy the data received from the backend into the bvec. | |
1038 | * Since bv_offset can be different than 0, and bv_len different | |
1039 | * than PAGE_SIZE, we have to keep track of the current offset, | |
1040 | * to be sure we are copying the data from the right shared page. | |
1041 | */ | |
b7649158 RPM |
1042 | for_each_sg(s->sg, sg, nseg, i) { |
1043 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); | |
0a8704a5 RPM |
1044 | shared_data = kmap_atomic( |
1045 | pfn_to_page(s->grants_used[i]->pfn)); | |
b7649158 RPM |
1046 | bvec_data = kmap_atomic(sg_page(sg)); |
1047 | memcpy(bvec_data + sg->offset, | |
1048 | shared_data + sg->offset, | |
1049 | sg->length); | |
1050 | kunmap_atomic(bvec_data); | |
0a8704a5 | 1051 | kunmap_atomic(shared_data); |
0a8704a5 RPM |
1052 | } |
1053 | } | |
1054 | /* Add the persistent grant into the list of free grants */ | |
402b27f9 | 1055 | for (i = 0; i < nseg; i++) { |
fbe363c4 RPM |
1056 | if (gnttab_query_foreign_access(s->grants_used[i]->gref)) { |
1057 | /* | |
1058 | * If the grant is still mapped by the backend (the | |
1059 | * backend has chosen to make this grant persistent) | |
1060 | * we add it at the head of the list, so it will be | |
1061 | * reused first. | |
1062 | */ | |
bfe11d6d RPM |
1063 | if (!info->feature_persistent) |
1064 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1065 | s->grants_used[i]->gref); | |
1066 | list_add(&s->grants_used[i]->node, &info->grants); | |
fbe363c4 RPM |
1067 | info->persistent_gnts_c++; |
1068 | } else { | |
1069 | /* | |
1070 | * If the grant is not mapped by the backend we end the | |
1071 | * foreign access and add it to the tail of the list, | |
1072 | * so it will not be picked again unless we run out of | |
1073 | * persistent grants. | |
1074 | */ | |
1075 | gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL); | |
1076 | s->grants_used[i]->gref = GRANT_INVALID_REF; | |
bfe11d6d | 1077 | list_add_tail(&s->grants_used[i]->node, &info->grants); |
fbe363c4 | 1078 | } |
0a8704a5 | 1079 | } |
402b27f9 RPM |
1080 | if (s->req.operation == BLKIF_OP_INDIRECT) { |
1081 | for (i = 0; i < INDIRECT_GREFS(nseg); i++) { | |
fbe363c4 | 1082 | if (gnttab_query_foreign_access(s->indirect_grants[i]->gref)) { |
bfe11d6d RPM |
1083 | if (!info->feature_persistent) |
1084 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1085 | s->indirect_grants[i]->gref); | |
1086 | list_add(&s->indirect_grants[i]->node, &info->grants); | |
fbe363c4 RPM |
1087 | info->persistent_gnts_c++; |
1088 | } else { | |
bfe11d6d RPM |
1089 | struct page *indirect_page; |
1090 | ||
fbe363c4 | 1091 | gnttab_end_foreign_access(s->indirect_grants[i]->gref, 0, 0UL); |
bfe11d6d RPM |
1092 | /* |
1093 | * Add the used indirect page back to the list of | |
1094 | * available pages for indirect grefs. | |
1095 | */ | |
1096 | indirect_page = pfn_to_page(s->indirect_grants[i]->pfn); | |
1097 | list_add(&indirect_page->lru, &info->indirect_pages); | |
fbe363c4 | 1098 | s->indirect_grants[i]->gref = GRANT_INVALID_REF; |
bfe11d6d | 1099 | list_add_tail(&s->indirect_grants[i]->node, &info->grants); |
fbe363c4 | 1100 | } |
402b27f9 RPM |
1101 | } |
1102 | } | |
9f27ee59 JF |
1103 | } |
1104 | ||
1105 | static irqreturn_t blkif_interrupt(int irq, void *dev_id) | |
1106 | { | |
1107 | struct request *req; | |
1108 | struct blkif_response *bret; | |
1109 | RING_IDX i, rp; | |
1110 | unsigned long flags; | |
1111 | struct blkfront_info *info = (struct blkfront_info *)dev_id; | |
f530f036 | 1112 | int error; |
9f27ee59 | 1113 | |
3467811e | 1114 | spin_lock_irqsave(&info->io_lock, flags); |
9f27ee59 JF |
1115 | |
1116 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { | |
3467811e | 1117 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
1118 | return IRQ_HANDLED; |
1119 | } | |
1120 | ||
1121 | again: | |
1122 | rp = info->ring.sring->rsp_prod; | |
1123 | rmb(); /* Ensure we see queued responses up to 'rp'. */ | |
1124 | ||
1125 | for (i = info->ring.rsp_cons; i != rp; i++) { | |
1126 | unsigned long id; | |
9f27ee59 JF |
1127 | |
1128 | bret = RING_GET_RESPONSE(&info->ring, i); | |
1129 | id = bret->id; | |
6878c32e KRW |
1130 | /* |
1131 | * The backend has messed up and given us an id that we would | |
1132 | * never have given to it (we stamp it up to BLK_RING_SIZE - | |
1133 | * look in get_id_from_freelist. | |
1134 | */ | |
1135 | if (id >= BLK_RING_SIZE) { | |
1136 | WARN(1, "%s: response to %s has incorrect id (%ld)\n", | |
1137 | info->gd->disk_name, op_name(bret->operation), id); | |
1138 | /* We can't safely get the 'struct request' as | |
1139 | * the id is busted. */ | |
1140 | continue; | |
1141 | } | |
a945b980 | 1142 | req = info->shadow[id].request; |
9f27ee59 | 1143 | |
5ea42986 | 1144 | if (bret->operation != BLKIF_OP_DISCARD) |
0a8704a5 | 1145 | blkif_completion(&info->shadow[id], info, bret); |
9f27ee59 | 1146 | |
6878c32e KRW |
1147 | if (add_id_to_freelist(info, id)) { |
1148 | WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n", | |
1149 | info->gd->disk_name, op_name(bret->operation), id); | |
1150 | continue; | |
1151 | } | |
9f27ee59 | 1152 | |
f530f036 | 1153 | error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO; |
9f27ee59 | 1154 | switch (bret->operation) { |
ed30bf31 LD |
1155 | case BLKIF_OP_DISCARD: |
1156 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
1157 | struct request_queue *rq = info->rq; | |
6878c32e KRW |
1158 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1159 | info->gd->disk_name, op_name(bret->operation)); | |
ed30bf31 LD |
1160 | error = -EOPNOTSUPP; |
1161 | info->feature_discard = 0; | |
5ea42986 | 1162 | info->feature_secdiscard = 0; |
ed30bf31 | 1163 | queue_flag_clear(QUEUE_FLAG_DISCARD, rq); |
5ea42986 | 1164 | queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq); |
ed30bf31 LD |
1165 | } |
1166 | __blk_end_request_all(req, error); | |
1167 | break; | |
edf6ef59 | 1168 | case BLKIF_OP_FLUSH_DISKCACHE: |
9f27ee59 JF |
1169 | case BLKIF_OP_WRITE_BARRIER: |
1170 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
6878c32e KRW |
1171 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1172 | info->gd->disk_name, op_name(bret->operation)); | |
f530f036 | 1173 | error = -EOPNOTSUPP; |
dcb8baec JF |
1174 | } |
1175 | if (unlikely(bret->status == BLKIF_RSP_ERROR && | |
97e36834 | 1176 | info->shadow[id].req.u.rw.nr_segments == 0)) { |
6878c32e KRW |
1177 | printk(KERN_WARNING "blkfront: %s: empty %s op failed\n", |
1178 | info->gd->disk_name, op_name(bret->operation)); | |
dcb8baec JF |
1179 | error = -EOPNOTSUPP; |
1180 | } | |
1181 | if (unlikely(error)) { | |
1182 | if (error == -EOPNOTSUPP) | |
1183 | error = 0; | |
4913efe4 | 1184 | info->feature_flush = 0; |
edf6ef59 | 1185 | info->flush_op = 0; |
4913efe4 | 1186 | xlvbd_flush(info); |
9f27ee59 JF |
1187 | } |
1188 | /* fall through */ | |
1189 | case BLKIF_OP_READ: | |
1190 | case BLKIF_OP_WRITE: | |
1191 | if (unlikely(bret->status != BLKIF_RSP_OKAY)) | |
1192 | dev_dbg(&info->xbdev->dev, "Bad return from blkdev data " | |
1193 | "request: %x\n", bret->status); | |
1194 | ||
40cbbb78 | 1195 | __blk_end_request_all(req, error); |
9f27ee59 JF |
1196 | break; |
1197 | default: | |
1198 | BUG(); | |
1199 | } | |
1200 | } | |
1201 | ||
1202 | info->ring.rsp_cons = i; | |
1203 | ||
1204 | if (i != info->ring.req_prod_pvt) { | |
1205 | int more_to_do; | |
1206 | RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do); | |
1207 | if (more_to_do) | |
1208 | goto again; | |
1209 | } else | |
1210 | info->ring.sring->rsp_event = i + 1; | |
1211 | ||
1212 | kick_pending_request_queues(info); | |
1213 | ||
3467811e | 1214 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
1215 | |
1216 | return IRQ_HANDLED; | |
1217 | } | |
1218 | ||
1219 | ||
1220 | static int setup_blkring(struct xenbus_device *dev, | |
1221 | struct blkfront_info *info) | |
1222 | { | |
1223 | struct blkif_sring *sring; | |
1224 | int err; | |
1225 | ||
1226 | info->ring_ref = GRANT_INVALID_REF; | |
1227 | ||
a144ff09 | 1228 | sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH); |
9f27ee59 JF |
1229 | if (!sring) { |
1230 | xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); | |
1231 | return -ENOMEM; | |
1232 | } | |
1233 | SHARED_RING_INIT(sring); | |
1234 | FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE); | |
9e973e64 | 1235 | |
9f27ee59 JF |
1236 | err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring)); |
1237 | if (err < 0) { | |
1238 | free_page((unsigned long)sring); | |
1239 | info->ring.sring = NULL; | |
1240 | goto fail; | |
1241 | } | |
1242 | info->ring_ref = err; | |
1243 | ||
1244 | err = xenbus_alloc_evtchn(dev, &info->evtchn); | |
1245 | if (err) | |
1246 | goto fail; | |
1247 | ||
89c30f16 TT |
1248 | err = bind_evtchn_to_irqhandler(info->evtchn, blkif_interrupt, 0, |
1249 | "blkif", info); | |
9f27ee59 JF |
1250 | if (err <= 0) { |
1251 | xenbus_dev_fatal(dev, err, | |
1252 | "bind_evtchn_to_irqhandler failed"); | |
1253 | goto fail; | |
1254 | } | |
1255 | info->irq = err; | |
1256 | ||
1257 | return 0; | |
1258 | fail: | |
1259 | blkif_free(info, 0); | |
1260 | return err; | |
1261 | } | |
1262 | ||
1263 | ||
1264 | /* Common code used when first setting up, and when resuming. */ | |
203fd61f | 1265 | static int talk_to_blkback(struct xenbus_device *dev, |
9f27ee59 JF |
1266 | struct blkfront_info *info) |
1267 | { | |
1268 | const char *message = NULL; | |
1269 | struct xenbus_transaction xbt; | |
1270 | int err; | |
1271 | ||
1272 | /* Create shared ring, alloc event channel. */ | |
1273 | err = setup_blkring(dev, info); | |
1274 | if (err) | |
1275 | goto out; | |
1276 | ||
1277 | again: | |
1278 | err = xenbus_transaction_start(&xbt); | |
1279 | if (err) { | |
1280 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
1281 | goto destroy_blkring; | |
1282 | } | |
1283 | ||
1284 | err = xenbus_printf(xbt, dev->nodename, | |
1285 | "ring-ref", "%u", info->ring_ref); | |
1286 | if (err) { | |
1287 | message = "writing ring-ref"; | |
1288 | goto abort_transaction; | |
1289 | } | |
1290 | err = xenbus_printf(xbt, dev->nodename, | |
1291 | "event-channel", "%u", info->evtchn); | |
1292 | if (err) { | |
1293 | message = "writing event-channel"; | |
1294 | goto abort_transaction; | |
1295 | } | |
3e334239 MA |
1296 | err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", |
1297 | XEN_IO_PROTO_ABI_NATIVE); | |
1298 | if (err) { | |
1299 | message = "writing protocol"; | |
1300 | goto abort_transaction; | |
1301 | } | |
0a8704a5 | 1302 | err = xenbus_printf(xbt, dev->nodename, |
cb5bd4d1 | 1303 | "feature-persistent", "%u", 1); |
0a8704a5 RPM |
1304 | if (err) |
1305 | dev_warn(&dev->dev, | |
1306 | "writing persistent grants feature to xenbus"); | |
9f27ee59 JF |
1307 | |
1308 | err = xenbus_transaction_end(xbt, 0); | |
1309 | if (err) { | |
1310 | if (err == -EAGAIN) | |
1311 | goto again; | |
1312 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
1313 | goto destroy_blkring; | |
1314 | } | |
1315 | ||
1316 | xenbus_switch_state(dev, XenbusStateInitialised); | |
1317 | ||
1318 | return 0; | |
1319 | ||
1320 | abort_transaction: | |
1321 | xenbus_transaction_end(xbt, 1); | |
1322 | if (message) | |
1323 | xenbus_dev_fatal(dev, err, "%s", message); | |
1324 | destroy_blkring: | |
1325 | blkif_free(info, 0); | |
1326 | out: | |
1327 | return err; | |
1328 | } | |
1329 | ||
9f27ee59 JF |
1330 | /** |
1331 | * Entry point to this code when a new device is created. Allocate the basic | |
1332 | * structures and the ring buffer for communication with the backend, and | |
1333 | * inform the backend of the appropriate details for those. Switch to | |
1334 | * Initialised state. | |
1335 | */ | |
1336 | static int blkfront_probe(struct xenbus_device *dev, | |
1337 | const struct xenbus_device_id *id) | |
1338 | { | |
1339 | int err, vdevice, i; | |
1340 | struct blkfront_info *info; | |
1341 | ||
1342 | /* FIXME: Use dynamic device id if this is not set. */ | |
1343 | err = xenbus_scanf(XBT_NIL, dev->nodename, | |
1344 | "virtual-device", "%i", &vdevice); | |
1345 | if (err != 1) { | |
9246b5f0 CL |
1346 | /* go looking in the extended area instead */ |
1347 | err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext", | |
1348 | "%i", &vdevice); | |
1349 | if (err != 1) { | |
1350 | xenbus_dev_fatal(dev, err, "reading virtual-device"); | |
1351 | return err; | |
1352 | } | |
9f27ee59 JF |
1353 | } |
1354 | ||
b98a409b SS |
1355 | if (xen_hvm_domain()) { |
1356 | char *type; | |
1357 | int len; | |
1358 | /* no unplug has been done: do not hook devices != xen vbds */ | |
51c71a3b | 1359 | if (xen_has_pv_and_legacy_disk_devices()) { |
b98a409b SS |
1360 | int major; |
1361 | ||
1362 | if (!VDEV_IS_EXTENDED(vdevice)) | |
1363 | major = BLKIF_MAJOR(vdevice); | |
1364 | else | |
1365 | major = XENVBD_MAJOR; | |
1366 | ||
1367 | if (major != XENVBD_MAJOR) { | |
1368 | printk(KERN_INFO | |
1369 | "%s: HVM does not support vbd %d as xen block device\n", | |
1370 | __FUNCTION__, vdevice); | |
1371 | return -ENODEV; | |
1372 | } | |
1373 | } | |
1374 | /* do not create a PV cdrom device if we are an HVM guest */ | |
1375 | type = xenbus_read(XBT_NIL, dev->nodename, "device-type", &len); | |
1376 | if (IS_ERR(type)) | |
1377 | return -ENODEV; | |
1378 | if (strncmp(type, "cdrom", 5) == 0) { | |
1379 | kfree(type); | |
c1c5413a SS |
1380 | return -ENODEV; |
1381 | } | |
b98a409b | 1382 | kfree(type); |
c1c5413a | 1383 | } |
9f27ee59 JF |
1384 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
1385 | if (!info) { | |
1386 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
1387 | return -ENOMEM; | |
1388 | } | |
1389 | ||
b70f5fa0 | 1390 | mutex_init(&info->mutex); |
3467811e | 1391 | spin_lock_init(&info->io_lock); |
9f27ee59 JF |
1392 | info->xbdev = dev; |
1393 | info->vdevice = vdevice; | |
bfe11d6d RPM |
1394 | INIT_LIST_HEAD(&info->grants); |
1395 | INIT_LIST_HEAD(&info->indirect_pages); | |
0a8704a5 | 1396 | info->persistent_gnts_c = 0; |
9f27ee59 JF |
1397 | info->connected = BLKIF_STATE_DISCONNECTED; |
1398 | INIT_WORK(&info->work, blkif_restart_queue); | |
1399 | ||
1400 | for (i = 0; i < BLK_RING_SIZE; i++) | |
97e36834 KRW |
1401 | info->shadow[i].req.u.rw.id = i+1; |
1402 | info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff; | |
9f27ee59 JF |
1403 | |
1404 | /* Front end dir is a number, which is used as the id. */ | |
1405 | info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); | |
a1b4b12b | 1406 | dev_set_drvdata(&dev->dev, info); |
9f27ee59 | 1407 | |
203fd61f | 1408 | err = talk_to_blkback(dev, info); |
9f27ee59 JF |
1409 | if (err) { |
1410 | kfree(info); | |
a1b4b12b | 1411 | dev_set_drvdata(&dev->dev, NULL); |
9f27ee59 JF |
1412 | return err; |
1413 | } | |
1414 | ||
1415 | return 0; | |
1416 | } | |
1417 | ||
402b27f9 RPM |
1418 | static void split_bio_end(struct bio *bio, int error) |
1419 | { | |
1420 | struct split_bio *split_bio = bio->bi_private; | |
1421 | ||
1422 | if (error) | |
1423 | split_bio->err = error; | |
1424 | ||
1425 | if (atomic_dec_and_test(&split_bio->pending)) { | |
1426 | split_bio->bio->bi_phys_segments = 0; | |
1427 | bio_endio(split_bio->bio, split_bio->err); | |
1428 | kfree(split_bio); | |
1429 | } | |
1430 | bio_put(bio); | |
1431 | } | |
9f27ee59 JF |
1432 | |
1433 | static int blkif_recover(struct blkfront_info *info) | |
1434 | { | |
1435 | int i; | |
402b27f9 | 1436 | struct request *req, *n; |
9f27ee59 | 1437 | struct blk_shadow *copy; |
402b27f9 RPM |
1438 | int rc; |
1439 | struct bio *bio, *cloned_bio; | |
1440 | struct bio_list bio_list, merge_bio; | |
1441 | unsigned int segs, offset; | |
1442 | int pending, size; | |
1443 | struct split_bio *split_bio; | |
1444 | struct list_head requests; | |
9f27ee59 JF |
1445 | |
1446 | /* Stage 1: Make a safe copy of the shadow state. */ | |
29d0b218 | 1447 | copy = kmemdup(info->shadow, sizeof(info->shadow), |
a144ff09 | 1448 | GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); |
9f27ee59 JF |
1449 | if (!copy) |
1450 | return -ENOMEM; | |
9f27ee59 JF |
1451 | |
1452 | /* Stage 2: Set up free list. */ | |
1453 | memset(&info->shadow, 0, sizeof(info->shadow)); | |
1454 | for (i = 0; i < BLK_RING_SIZE; i++) | |
97e36834 | 1455 | info->shadow[i].req.u.rw.id = i+1; |
9f27ee59 | 1456 | info->shadow_free = info->ring.req_prod_pvt; |
97e36834 | 1457 | info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff; |
9f27ee59 | 1458 | |
402b27f9 RPM |
1459 | rc = blkfront_setup_indirect(info); |
1460 | if (rc) { | |
1461 | kfree(copy); | |
1462 | return rc; | |
1463 | } | |
1464 | ||
1465 | segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
1466 | blk_queue_max_segments(info->rq, segs); | |
1467 | bio_list_init(&bio_list); | |
1468 | INIT_LIST_HEAD(&requests); | |
9f27ee59 JF |
1469 | for (i = 0; i < BLK_RING_SIZE; i++) { |
1470 | /* Not in use? */ | |
a945b980 | 1471 | if (!copy[i].request) |
9f27ee59 JF |
1472 | continue; |
1473 | ||
402b27f9 RPM |
1474 | /* |
1475 | * Get the bios in the request so we can re-queue them. | |
1476 | */ | |
1477 | if (copy[i].request->cmd_flags & | |
1478 | (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) { | |
1479 | /* | |
1480 | * Flush operations don't contain bios, so | |
1481 | * we need to requeue the whole request | |
1482 | */ | |
1483 | list_add(©[i].request->queuelist, &requests); | |
1484 | continue; | |
5ea42986 | 1485 | } |
402b27f9 RPM |
1486 | merge_bio.head = copy[i].request->bio; |
1487 | merge_bio.tail = copy[i].request->biotail; | |
1488 | bio_list_merge(&bio_list, &merge_bio); | |
1489 | copy[i].request->bio = NULL; | |
1490 | blk_put_request(copy[i].request); | |
9f27ee59 JF |
1491 | } |
1492 | ||
1493 | kfree(copy); | |
1494 | ||
402b27f9 RPM |
1495 | /* |
1496 | * Empty the queue, this is important because we might have | |
1497 | * requests in the queue with more segments than what we | |
1498 | * can handle now. | |
1499 | */ | |
1500 | spin_lock_irq(&info->io_lock); | |
1501 | while ((req = blk_fetch_request(info->rq)) != NULL) { | |
1502 | if (req->cmd_flags & | |
1503 | (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) { | |
1504 | list_add(&req->queuelist, &requests); | |
1505 | continue; | |
1506 | } | |
1507 | merge_bio.head = req->bio; | |
1508 | merge_bio.tail = req->biotail; | |
1509 | bio_list_merge(&bio_list, &merge_bio); | |
1510 | req->bio = NULL; | |
1511 | if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) | |
1512 | pr_alert("diskcache flush request found!\n"); | |
1513 | __blk_put_request(info->rq, req); | |
1514 | } | |
1515 | spin_unlock_irq(&info->io_lock); | |
1516 | ||
9f27ee59 JF |
1517 | xenbus_switch_state(info->xbdev, XenbusStateConnected); |
1518 | ||
3467811e | 1519 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1520 | |
1521 | /* Now safe for us to use the shared ring */ | |
1522 | info->connected = BLKIF_STATE_CONNECTED; | |
1523 | ||
9f27ee59 JF |
1524 | /* Kick any other new requests queued since we resumed */ |
1525 | kick_pending_request_queues(info); | |
1526 | ||
402b27f9 RPM |
1527 | list_for_each_entry_safe(req, n, &requests, queuelist) { |
1528 | /* Requeue pending requests (flush or discard) */ | |
1529 | list_del_init(&req->queuelist); | |
1530 | BUG_ON(req->nr_phys_segments > segs); | |
1531 | blk_requeue_request(info->rq, req); | |
1532 | } | |
3467811e | 1533 | spin_unlock_irq(&info->io_lock); |
9f27ee59 | 1534 | |
402b27f9 RPM |
1535 | while ((bio = bio_list_pop(&bio_list)) != NULL) { |
1536 | /* Traverse the list of pending bios and re-queue them */ | |
1537 | if (bio_segments(bio) > segs) { | |
1538 | /* | |
1539 | * This bio has more segments than what we can | |
1540 | * handle, we have to split it. | |
1541 | */ | |
1542 | pending = (bio_segments(bio) + segs - 1) / segs; | |
1543 | split_bio = kzalloc(sizeof(*split_bio), GFP_NOIO); | |
1544 | BUG_ON(split_bio == NULL); | |
1545 | atomic_set(&split_bio->pending, pending); | |
1546 | split_bio->bio = bio; | |
1547 | for (i = 0; i < pending; i++) { | |
1548 | offset = (i * segs * PAGE_SIZE) >> 9; | |
1549 | size = min((unsigned int)(segs * PAGE_SIZE) >> 9, | |
4f024f37 | 1550 | (unsigned int)bio_sectors(bio) - offset); |
402b27f9 RPM |
1551 | cloned_bio = bio_clone(bio, GFP_NOIO); |
1552 | BUG_ON(cloned_bio == NULL); | |
6678d83f | 1553 | bio_trim(cloned_bio, offset, size); |
402b27f9 RPM |
1554 | cloned_bio->bi_private = split_bio; |
1555 | cloned_bio->bi_end_io = split_bio_end; | |
1556 | submit_bio(cloned_bio->bi_rw, cloned_bio); | |
1557 | } | |
1558 | /* | |
1559 | * Now we have to wait for all those smaller bios to | |
1560 | * end, so we can also end the "parent" bio. | |
1561 | */ | |
1562 | continue; | |
1563 | } | |
1564 | /* We don't need to split this bio */ | |
1565 | submit_bio(bio->bi_rw, bio); | |
1566 | } | |
1567 | ||
9f27ee59 JF |
1568 | return 0; |
1569 | } | |
1570 | ||
1571 | /** | |
1572 | * We are reconnecting to the backend, due to a suspend/resume, or a backend | |
1573 | * driver restart. We tear down our blkif structure and recreate it, but | |
1574 | * leave the device-layer structures intact so that this is transparent to the | |
1575 | * rest of the kernel. | |
1576 | */ | |
1577 | static int blkfront_resume(struct xenbus_device *dev) | |
1578 | { | |
a1b4b12b | 1579 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 JF |
1580 | int err; |
1581 | ||
1582 | dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename); | |
1583 | ||
1584 | blkif_free(info, info->connected == BLKIF_STATE_CONNECTED); | |
1585 | ||
203fd61f | 1586 | err = talk_to_blkback(dev, info); |
402b27f9 RPM |
1587 | |
1588 | /* | |
1589 | * We have to wait for the backend to switch to | |
1590 | * connected state, since we want to read which | |
1591 | * features it supports. | |
1592 | */ | |
9f27ee59 JF |
1593 | |
1594 | return err; | |
1595 | } | |
1596 | ||
b70f5fa0 DS |
1597 | static void |
1598 | blkfront_closing(struct blkfront_info *info) | |
1599 | { | |
1600 | struct xenbus_device *xbdev = info->xbdev; | |
1601 | struct block_device *bdev = NULL; | |
1602 | ||
1603 | mutex_lock(&info->mutex); | |
1604 | ||
1605 | if (xbdev->state == XenbusStateClosing) { | |
1606 | mutex_unlock(&info->mutex); | |
1607 | return; | |
1608 | } | |
1609 | ||
1610 | if (info->gd) | |
1611 | bdev = bdget_disk(info->gd, 0); | |
1612 | ||
1613 | mutex_unlock(&info->mutex); | |
1614 | ||
1615 | if (!bdev) { | |
1616 | xenbus_frontend_closed(xbdev); | |
1617 | return; | |
1618 | } | |
1619 | ||
1620 | mutex_lock(&bdev->bd_mutex); | |
1621 | ||
7b32d104 | 1622 | if (bdev->bd_openers) { |
b70f5fa0 DS |
1623 | xenbus_dev_error(xbdev, -EBUSY, |
1624 | "Device in use; refusing to close"); | |
1625 | xenbus_switch_state(xbdev, XenbusStateClosing); | |
1626 | } else { | |
1627 | xlvbd_release_gendisk(info); | |
1628 | xenbus_frontend_closed(xbdev); | |
1629 | } | |
1630 | ||
1631 | mutex_unlock(&bdev->bd_mutex); | |
1632 | bdput(bdev); | |
1633 | } | |
9f27ee59 | 1634 | |
ed30bf31 LD |
1635 | static void blkfront_setup_discard(struct blkfront_info *info) |
1636 | { | |
1637 | int err; | |
1638 | char *type; | |
1639 | unsigned int discard_granularity; | |
1640 | unsigned int discard_alignment; | |
5ea42986 | 1641 | unsigned int discard_secure; |
ed30bf31 LD |
1642 | |
1643 | type = xenbus_read(XBT_NIL, info->xbdev->otherend, "type", NULL); | |
1644 | if (IS_ERR(type)) | |
1645 | return; | |
1646 | ||
5ea42986 | 1647 | info->feature_secdiscard = 0; |
ed30bf31 LD |
1648 | if (strncmp(type, "phy", 3) == 0) { |
1649 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1650 | "discard-granularity", "%u", &discard_granularity, | |
1651 | "discard-alignment", "%u", &discard_alignment, | |
1652 | NULL); | |
1653 | if (!err) { | |
1654 | info->feature_discard = 1; | |
1655 | info->discard_granularity = discard_granularity; | |
1656 | info->discard_alignment = discard_alignment; | |
1657 | } | |
5ea42986 KRW |
1658 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, |
1659 | "discard-secure", "%d", &discard_secure, | |
1660 | NULL); | |
1661 | if (!err) | |
1662 | info->feature_secdiscard = discard_secure; | |
1663 | ||
ed30bf31 LD |
1664 | } else if (strncmp(type, "file", 4) == 0) |
1665 | info->feature_discard = 1; | |
1666 | ||
1667 | kfree(type); | |
1668 | } | |
1669 | ||
402b27f9 RPM |
1670 | static int blkfront_setup_indirect(struct blkfront_info *info) |
1671 | { | |
1672 | unsigned int indirect_segments, segs; | |
1673 | int err, i; | |
1674 | ||
1675 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1676 | "feature-max-indirect-segments", "%u", &indirect_segments, | |
1677 | NULL); | |
1678 | if (err) { | |
1679 | info->max_indirect_segments = 0; | |
1680 | segs = BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
1681 | } else { | |
1682 | info->max_indirect_segments = min(indirect_segments, | |
1683 | xen_blkif_max_segments); | |
1684 | segs = info->max_indirect_segments; | |
1685 | } | |
402b27f9 RPM |
1686 | |
1687 | err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE); | |
1688 | if (err) | |
1689 | goto out_of_memory; | |
1690 | ||
bfe11d6d RPM |
1691 | if (!info->feature_persistent && info->max_indirect_segments) { |
1692 | /* | |
1693 | * We are using indirect descriptors but not persistent | |
1694 | * grants, we need to allocate a set of pages that can be | |
1695 | * used for mapping indirect grefs | |
1696 | */ | |
1697 | int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE; | |
1698 | ||
1699 | BUG_ON(!list_empty(&info->indirect_pages)); | |
1700 | for (i = 0; i < num; i++) { | |
1701 | struct page *indirect_page = alloc_page(GFP_NOIO); | |
1702 | if (!indirect_page) | |
1703 | goto out_of_memory; | |
1704 | list_add(&indirect_page->lru, &info->indirect_pages); | |
1705 | } | |
1706 | } | |
1707 | ||
402b27f9 RPM |
1708 | for (i = 0; i < BLK_RING_SIZE; i++) { |
1709 | info->shadow[i].grants_used = kzalloc( | |
1710 | sizeof(info->shadow[i].grants_used[0]) * segs, | |
1711 | GFP_NOIO); | |
b7649158 | 1712 | info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * segs, GFP_NOIO); |
402b27f9 RPM |
1713 | if (info->max_indirect_segments) |
1714 | info->shadow[i].indirect_grants = kzalloc( | |
1715 | sizeof(info->shadow[i].indirect_grants[0]) * | |
1716 | INDIRECT_GREFS(segs), | |
1717 | GFP_NOIO); | |
1718 | if ((info->shadow[i].grants_used == NULL) || | |
b7649158 | 1719 | (info->shadow[i].sg == NULL) || |
402b27f9 RPM |
1720 | (info->max_indirect_segments && |
1721 | (info->shadow[i].indirect_grants == NULL))) | |
1722 | goto out_of_memory; | |
b7649158 | 1723 | sg_init_table(info->shadow[i].sg, segs); |
402b27f9 RPM |
1724 | } |
1725 | ||
1726 | ||
1727 | return 0; | |
1728 | ||
1729 | out_of_memory: | |
402b27f9 RPM |
1730 | for (i = 0; i < BLK_RING_SIZE; i++) { |
1731 | kfree(info->shadow[i].grants_used); | |
1732 | info->shadow[i].grants_used = NULL; | |
b7649158 RPM |
1733 | kfree(info->shadow[i].sg); |
1734 | info->shadow[i].sg = NULL; | |
402b27f9 RPM |
1735 | kfree(info->shadow[i].indirect_grants); |
1736 | info->shadow[i].indirect_grants = NULL; | |
1737 | } | |
bfe11d6d RPM |
1738 | if (!list_empty(&info->indirect_pages)) { |
1739 | struct page *indirect_page, *n; | |
1740 | list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) { | |
1741 | list_del(&indirect_page->lru); | |
1742 | __free_page(indirect_page); | |
1743 | } | |
1744 | } | |
402b27f9 RPM |
1745 | return -ENOMEM; |
1746 | } | |
1747 | ||
9f27ee59 JF |
1748 | /* |
1749 | * Invoked when the backend is finally 'ready' (and has told produced | |
1750 | * the details about the physical device - #sectors, size, etc). | |
1751 | */ | |
1752 | static void blkfront_connect(struct blkfront_info *info) | |
1753 | { | |
1754 | unsigned long long sectors; | |
1755 | unsigned long sector_size; | |
7c4d7d71 | 1756 | unsigned int physical_sector_size; |
9f27ee59 JF |
1757 | unsigned int binfo; |
1758 | int err; | |
0a8704a5 | 1759 | int barrier, flush, discard, persistent; |
9f27ee59 | 1760 | |
1fa73be6 S |
1761 | switch (info->connected) { |
1762 | case BLKIF_STATE_CONNECTED: | |
1763 | /* | |
1764 | * Potentially, the back-end may be signalling | |
1765 | * a capacity change; update the capacity. | |
1766 | */ | |
1767 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1768 | "sectors", "%Lu", §ors); | |
1769 | if (XENBUS_EXIST_ERR(err)) | |
1770 | return; | |
1771 | printk(KERN_INFO "Setting capacity to %Lu\n", | |
1772 | sectors); | |
1773 | set_capacity(info->gd, sectors); | |
2def141e | 1774 | revalidate_disk(info->gd); |
1fa73be6 | 1775 | |
402b27f9 | 1776 | return; |
1fa73be6 | 1777 | case BLKIF_STATE_SUSPENDED: |
402b27f9 RPM |
1778 | /* |
1779 | * If we are recovering from suspension, we need to wait | |
1780 | * for the backend to announce it's features before | |
1781 | * reconnecting, at least we need to know if the backend | |
1782 | * supports indirect descriptors, and how many. | |
1783 | */ | |
1784 | blkif_recover(info); | |
9f27ee59 JF |
1785 | return; |
1786 | ||
b4dddb49 JF |
1787 | default: |
1788 | break; | |
1fa73be6 | 1789 | } |
9f27ee59 JF |
1790 | |
1791 | dev_dbg(&info->xbdev->dev, "%s:%s.\n", | |
1792 | __func__, info->xbdev->otherend); | |
1793 | ||
1794 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1795 | "sectors", "%llu", §ors, | |
1796 | "info", "%u", &binfo, | |
1797 | "sector-size", "%lu", §or_size, | |
1798 | NULL); | |
1799 | if (err) { | |
1800 | xenbus_dev_fatal(info->xbdev, err, | |
1801 | "reading backend fields at %s", | |
1802 | info->xbdev->otherend); | |
1803 | return; | |
1804 | } | |
1805 | ||
7c4d7d71 SB |
1806 | /* |
1807 | * physcial-sector-size is a newer field, so old backends may not | |
1808 | * provide this. Assume physical sector size to be the same as | |
1809 | * sector_size in that case. | |
1810 | */ | |
1811 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1812 | "physical-sector-size", "%u", &physical_sector_size); | |
1813 | if (err != 1) | |
1814 | physical_sector_size = sector_size; | |
1815 | ||
edf6ef59 KRW |
1816 | info->feature_flush = 0; |
1817 | info->flush_op = 0; | |
1818 | ||
9f27ee59 | 1819 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, |
4352b47a | 1820 | "feature-barrier", "%d", &barrier, |
9f27ee59 | 1821 | NULL); |
7901d141 JF |
1822 | |
1823 | /* | |
1824 | * If there's no "feature-barrier" defined, then it means | |
1825 | * we're dealing with a very old backend which writes | |
4913efe4 | 1826 | * synchronously; nothing to do. |
7901d141 | 1827 | * |
6958f145 | 1828 | * If there are barriers, then we use flush. |
7901d141 | 1829 | */ |
edf6ef59 | 1830 | if (!err && barrier) { |
be2f8373 | 1831 | info->feature_flush = REQ_FLUSH | REQ_FUA; |
edf6ef59 KRW |
1832 | info->flush_op = BLKIF_OP_WRITE_BARRIER; |
1833 | } | |
1834 | /* | |
1835 | * And if there is "feature-flush-cache" use that above | |
1836 | * barriers. | |
1837 | */ | |
1838 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1839 | "feature-flush-cache", "%d", &flush, | |
1840 | NULL); | |
9f27ee59 | 1841 | |
edf6ef59 KRW |
1842 | if (!err && flush) { |
1843 | info->feature_flush = REQ_FLUSH; | |
1844 | info->flush_op = BLKIF_OP_FLUSH_DISKCACHE; | |
1845 | } | |
ed30bf31 LD |
1846 | |
1847 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1848 | "feature-discard", "%d", &discard, | |
1849 | NULL); | |
1850 | ||
1851 | if (!err && discard) | |
1852 | blkfront_setup_discard(info); | |
1853 | ||
0a8704a5 RPM |
1854 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, |
1855 | "feature-persistent", "%u", &persistent, | |
1856 | NULL); | |
1857 | if (err) | |
1858 | info->feature_persistent = 0; | |
1859 | else | |
1860 | info->feature_persistent = persistent; | |
1861 | ||
402b27f9 RPM |
1862 | err = blkfront_setup_indirect(info); |
1863 | if (err) { | |
1864 | xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s", | |
1865 | info->xbdev->otherend); | |
1866 | return; | |
1867 | } | |
1868 | ||
7c4d7d71 SB |
1869 | err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size, |
1870 | physical_sector_size); | |
9f27ee59 JF |
1871 | if (err) { |
1872 | xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", | |
1873 | info->xbdev->otherend); | |
1874 | return; | |
1875 | } | |
1876 | ||
1877 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1878 | ||
1879 | /* Kick pending requests. */ | |
3467811e | 1880 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1881 | info->connected = BLKIF_STATE_CONNECTED; |
1882 | kick_pending_request_queues(info); | |
3467811e | 1883 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1884 | |
1885 | add_disk(info->gd); | |
1d78d705 CL |
1886 | |
1887 | info->is_ready = 1; | |
9f27ee59 JF |
1888 | } |
1889 | ||
9f27ee59 JF |
1890 | /** |
1891 | * Callback received when the backend's state changes. | |
1892 | */ | |
203fd61f | 1893 | static void blkback_changed(struct xenbus_device *dev, |
9f27ee59 JF |
1894 | enum xenbus_state backend_state) |
1895 | { | |
a1b4b12b | 1896 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 | 1897 | |
203fd61f | 1898 | dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); |
9f27ee59 JF |
1899 | |
1900 | switch (backend_state) { | |
1901 | case XenbusStateInitialising: | |
1902 | case XenbusStateInitWait: | |
1903 | case XenbusStateInitialised: | |
b78c9512 NI |
1904 | case XenbusStateReconfiguring: |
1905 | case XenbusStateReconfigured: | |
9f27ee59 | 1906 | case XenbusStateUnknown: |
9f27ee59 JF |
1907 | break; |
1908 | ||
1909 | case XenbusStateConnected: | |
1910 | blkfront_connect(info); | |
1911 | break; | |
1912 | ||
36613717 DV |
1913 | case XenbusStateClosed: |
1914 | if (dev->state == XenbusStateClosed) | |
1915 | break; | |
1916 | /* Missed the backend's Closing state -- fallthrough */ | |
9f27ee59 | 1917 | case XenbusStateClosing: |
b70f5fa0 | 1918 | blkfront_closing(info); |
9f27ee59 JF |
1919 | break; |
1920 | } | |
1921 | } | |
1922 | ||
fa1bd359 | 1923 | static int blkfront_remove(struct xenbus_device *xbdev) |
9f27ee59 | 1924 | { |
fa1bd359 DS |
1925 | struct blkfront_info *info = dev_get_drvdata(&xbdev->dev); |
1926 | struct block_device *bdev = NULL; | |
1927 | struct gendisk *disk; | |
9f27ee59 | 1928 | |
fa1bd359 | 1929 | dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename); |
9f27ee59 JF |
1930 | |
1931 | blkif_free(info, 0); | |
1932 | ||
fa1bd359 DS |
1933 | mutex_lock(&info->mutex); |
1934 | ||
1935 | disk = info->gd; | |
1936 | if (disk) | |
1937 | bdev = bdget_disk(disk, 0); | |
1938 | ||
1939 | info->xbdev = NULL; | |
1940 | mutex_unlock(&info->mutex); | |
1941 | ||
1942 | if (!bdev) { | |
1943 | kfree(info); | |
1944 | return 0; | |
1945 | } | |
1946 | ||
1947 | /* | |
1948 | * The xbdev was removed before we reached the Closed | |
1949 | * state. See if it's safe to remove the disk. If the bdev | |
1950 | * isn't closed yet, we let release take care of it. | |
1951 | */ | |
1952 | ||
1953 | mutex_lock(&bdev->bd_mutex); | |
1954 | info = disk->private_data; | |
1955 | ||
d54142c7 DS |
1956 | dev_warn(disk_to_dev(disk), |
1957 | "%s was hot-unplugged, %d stale handles\n", | |
1958 | xbdev->nodename, bdev->bd_openers); | |
1959 | ||
7b32d104 | 1960 | if (info && !bdev->bd_openers) { |
fa1bd359 DS |
1961 | xlvbd_release_gendisk(info); |
1962 | disk->private_data = NULL; | |
0e345826 | 1963 | kfree(info); |
fa1bd359 DS |
1964 | } |
1965 | ||
1966 | mutex_unlock(&bdev->bd_mutex); | |
1967 | bdput(bdev); | |
9f27ee59 JF |
1968 | |
1969 | return 0; | |
1970 | } | |
1971 | ||
1d78d705 CL |
1972 | static int blkfront_is_ready(struct xenbus_device *dev) |
1973 | { | |
a1b4b12b | 1974 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
1d78d705 | 1975 | |
5d7ed20e | 1976 | return info->is_ready && info->xbdev; |
1d78d705 CL |
1977 | } |
1978 | ||
a63c848b | 1979 | static int blkif_open(struct block_device *bdev, fmode_t mode) |
9f27ee59 | 1980 | { |
13961743 DS |
1981 | struct gendisk *disk = bdev->bd_disk; |
1982 | struct blkfront_info *info; | |
1983 | int err = 0; | |
6e9624b8 | 1984 | |
2a48fc0a | 1985 | mutex_lock(&blkfront_mutex); |
6e9624b8 | 1986 | |
13961743 DS |
1987 | info = disk->private_data; |
1988 | if (!info) { | |
1989 | /* xbdev gone */ | |
1990 | err = -ERESTARTSYS; | |
1991 | goto out; | |
1992 | } | |
1993 | ||
1994 | mutex_lock(&info->mutex); | |
1995 | ||
1996 | if (!info->gd) | |
1997 | /* xbdev is closed */ | |
1998 | err = -ERESTARTSYS; | |
1999 | ||
2000 | mutex_unlock(&info->mutex); | |
2001 | ||
13961743 | 2002 | out: |
2a48fc0a | 2003 | mutex_unlock(&blkfront_mutex); |
13961743 | 2004 | return err; |
9f27ee59 JF |
2005 | } |
2006 | ||
db2a144b | 2007 | static void blkif_release(struct gendisk *disk, fmode_t mode) |
9f27ee59 | 2008 | { |
a63c848b | 2009 | struct blkfront_info *info = disk->private_data; |
7fd152f4 DS |
2010 | struct block_device *bdev; |
2011 | struct xenbus_device *xbdev; | |
2012 | ||
2a48fc0a | 2013 | mutex_lock(&blkfront_mutex); |
7fd152f4 DS |
2014 | |
2015 | bdev = bdget_disk(disk, 0); | |
7fd152f4 | 2016 | |
2f089cb8 FP |
2017 | if (!bdev) { |
2018 | WARN(1, "Block device %s yanked out from us!\n", disk->disk_name); | |
2019 | goto out_mutex; | |
2020 | } | |
acfca3c6 DS |
2021 | if (bdev->bd_openers) |
2022 | goto out; | |
2023 | ||
7fd152f4 DS |
2024 | /* |
2025 | * Check if we have been instructed to close. We will have | |
2026 | * deferred this request, because the bdev was still open. | |
2027 | */ | |
2028 | ||
2029 | mutex_lock(&info->mutex); | |
2030 | xbdev = info->xbdev; | |
2031 | ||
2032 | if (xbdev && xbdev->state == XenbusStateClosing) { | |
2033 | /* pending switch to state closed */ | |
d54142c7 | 2034 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2035 | xlvbd_release_gendisk(info); |
2036 | xenbus_frontend_closed(info->xbdev); | |
2037 | } | |
2038 | ||
2039 | mutex_unlock(&info->mutex); | |
2040 | ||
2041 | if (!xbdev) { | |
2042 | /* sudden device removal */ | |
d54142c7 | 2043 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2044 | xlvbd_release_gendisk(info); |
2045 | disk->private_data = NULL; | |
2046 | kfree(info); | |
9f27ee59 | 2047 | } |
7fd152f4 | 2048 | |
a4cc14ec | 2049 | out: |
dad5cf65 | 2050 | bdput(bdev); |
2f089cb8 | 2051 | out_mutex: |
2a48fc0a | 2052 | mutex_unlock(&blkfront_mutex); |
9f27ee59 JF |
2053 | } |
2054 | ||
83d5cde4 | 2055 | static const struct block_device_operations xlvbd_block_fops = |
9f27ee59 JF |
2056 | { |
2057 | .owner = THIS_MODULE, | |
a63c848b AV |
2058 | .open = blkif_open, |
2059 | .release = blkif_release, | |
597592d9 | 2060 | .getgeo = blkif_getgeo, |
8a6cfeb6 | 2061 | .ioctl = blkif_ioctl, |
9f27ee59 JF |
2062 | }; |
2063 | ||
2064 | ||
ec9c42ec | 2065 | static const struct xenbus_device_id blkfront_ids[] = { |
9f27ee59 JF |
2066 | { "vbd" }, |
2067 | { "" } | |
2068 | }; | |
2069 | ||
73db144b | 2070 | static DEFINE_XENBUS_DRIVER(blkfront, , |
9f27ee59 JF |
2071 | .probe = blkfront_probe, |
2072 | .remove = blkfront_remove, | |
2073 | .resume = blkfront_resume, | |
203fd61f | 2074 | .otherend_changed = blkback_changed, |
1d78d705 | 2075 | .is_ready = blkfront_is_ready, |
73db144b | 2076 | ); |
9f27ee59 JF |
2077 | |
2078 | static int __init xlblk_init(void) | |
2079 | { | |
469738e6 LE |
2080 | int ret; |
2081 | ||
6e833587 | 2082 | if (!xen_domain()) |
9f27ee59 JF |
2083 | return -ENODEV; |
2084 | ||
51c71a3b | 2085 | if (!xen_has_pv_disk_devices()) |
b9136d20 IM |
2086 | return -ENODEV; |
2087 | ||
9f27ee59 JF |
2088 | if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { |
2089 | printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", | |
2090 | XENVBD_MAJOR, DEV_NAME); | |
2091 | return -ENODEV; | |
2092 | } | |
2093 | ||
73db144b | 2094 | ret = xenbus_register_frontend(&blkfront_driver); |
469738e6 LE |
2095 | if (ret) { |
2096 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2097 | return ret; | |
2098 | } | |
2099 | ||
2100 | return 0; | |
9f27ee59 JF |
2101 | } |
2102 | module_init(xlblk_init); | |
2103 | ||
2104 | ||
5a60d0cd | 2105 | static void __exit xlblk_exit(void) |
9f27ee59 | 2106 | { |
8605067f JB |
2107 | xenbus_unregister_driver(&blkfront_driver); |
2108 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2109 | kfree(minors); | |
9f27ee59 JF |
2110 | } |
2111 | module_exit(xlblk_exit); | |
2112 | ||
2113 | MODULE_DESCRIPTION("Xen virtual block device frontend"); | |
2114 | MODULE_LICENSE("GPL"); | |
2115 | MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR); | |
d2f0c52b | 2116 | MODULE_ALIAS("xen:vbd"); |
4f93f09b | 2117 | MODULE_ALIAS("xenblk"); |