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> | |
907c3eb1 | 40 | #include <linux/blk-mq.h> |
597592d9 | 41 | #include <linux/hdreg.h> |
440a01a7 | 42 | #include <linux/cdrom.h> |
9f27ee59 | 43 | #include <linux/module.h> |
5a0e3ad6 | 44 | #include <linux/slab.h> |
2a48fc0a | 45 | #include <linux/mutex.h> |
9e973e64 | 46 | #include <linux/scatterlist.h> |
34ae2e47 | 47 | #include <linux/bitmap.h> |
155b7edb | 48 | #include <linux/list.h> |
9f27ee59 | 49 | |
1ccbf534 | 50 | #include <xen/xen.h> |
9f27ee59 JF |
51 | #include <xen/xenbus.h> |
52 | #include <xen/grant_table.h> | |
53 | #include <xen/events.h> | |
54 | #include <xen/page.h> | |
c1c5413a | 55 | #include <xen/platform_pci.h> |
9f27ee59 JF |
56 | |
57 | #include <xen/interface/grant_table.h> | |
58 | #include <xen/interface/io/blkif.h> | |
3e334239 | 59 | #include <xen/interface/io/protocols.h> |
9f27ee59 JF |
60 | |
61 | #include <asm/xen/hypervisor.h> | |
62 | ||
63 | enum blkif_state { | |
64 | BLKIF_STATE_DISCONNECTED, | |
65 | BLKIF_STATE_CONNECTED, | |
66 | BLKIF_STATE_SUSPENDED, | |
67 | }; | |
68 | ||
0a8704a5 RPM |
69 | struct grant { |
70 | grant_ref_t gref; | |
a7a6df22 | 71 | struct page *page; |
155b7edb | 72 | struct list_head node; |
0a8704a5 RPM |
73 | }; |
74 | ||
9f27ee59 JF |
75 | struct blk_shadow { |
76 | struct blkif_request req; | |
a945b980 | 77 | struct request *request; |
402b27f9 RPM |
78 | struct grant **grants_used; |
79 | struct grant **indirect_grants; | |
b7649158 | 80 | struct scatterlist *sg; |
402b27f9 RPM |
81 | }; |
82 | ||
83 | struct split_bio { | |
84 | struct bio *bio; | |
85 | atomic_t pending; | |
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; |
907c3eb1 | 151 | struct blk_mq_tag_set tag_set; |
9f27ee59 JF |
152 | }; |
153 | ||
0e345826 JB |
154 | static unsigned int nr_minors; |
155 | static unsigned long *minors; | |
156 | static DEFINE_SPINLOCK(minor_lock); | |
157 | ||
9f27ee59 JF |
158 | #define GRANT_INVALID_REF 0 |
159 | ||
160 | #define PARTS_PER_DISK 16 | |
9246b5f0 | 161 | #define PARTS_PER_EXT_DISK 256 |
9f27ee59 JF |
162 | |
163 | #define BLKIF_MAJOR(dev) ((dev)>>8) | |
164 | #define BLKIF_MINOR(dev) ((dev) & 0xff) | |
165 | ||
9246b5f0 CL |
166 | #define EXT_SHIFT 28 |
167 | #define EXTENDED (1<<EXT_SHIFT) | |
168 | #define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED)) | |
169 | #define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED)) | |
c80a4209 SS |
170 | #define EMULATED_HD_DISK_MINOR_OFFSET (0) |
171 | #define EMULATED_HD_DISK_NAME_OFFSET (EMULATED_HD_DISK_MINOR_OFFSET / 256) | |
196cfe2a SB |
172 | #define EMULATED_SD_DISK_MINOR_OFFSET (0) |
173 | #define EMULATED_SD_DISK_NAME_OFFSET (EMULATED_SD_DISK_MINOR_OFFSET / 256) | |
9f27ee59 | 174 | |
9246b5f0 | 175 | #define DEV_NAME "xvd" /* name in /dev */ |
9f27ee59 | 176 | |
402b27f9 | 177 | #define SEGS_PER_INDIRECT_FRAME \ |
80bfa2f6 | 178 | (PAGE_SIZE/sizeof(struct blkif_request_segment)) |
402b27f9 RPM |
179 | #define INDIRECT_GREFS(_segs) \ |
180 | ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME) | |
181 | ||
182 | static int blkfront_setup_indirect(struct blkfront_info *info); | |
d50babbe | 183 | static int blkfront_gather_backend_features(struct blkfront_info *info); |
402b27f9 | 184 | |
9f27ee59 JF |
185 | static int get_id_from_freelist(struct blkfront_info *info) |
186 | { | |
187 | unsigned long free = info->shadow_free; | |
86839c56 | 188 | BUG_ON(free >= BLK_RING_SIZE(info)); |
97e36834 KRW |
189 | info->shadow_free = info->shadow[free].req.u.rw.id; |
190 | info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */ | |
9f27ee59 JF |
191 | return free; |
192 | } | |
193 | ||
6878c32e | 194 | static int add_id_to_freelist(struct blkfront_info *info, |
9f27ee59 JF |
195 | unsigned long id) |
196 | { | |
6878c32e KRW |
197 | if (info->shadow[id].req.u.rw.id != id) |
198 | return -EINVAL; | |
199 | if (info->shadow[id].request == NULL) | |
200 | return -EINVAL; | |
97e36834 | 201 | info->shadow[id].req.u.rw.id = info->shadow_free; |
a945b980 | 202 | info->shadow[id].request = NULL; |
9f27ee59 | 203 | info->shadow_free = id; |
6878c32e | 204 | return 0; |
9f27ee59 JF |
205 | } |
206 | ||
9c1e050c RPM |
207 | static int fill_grant_buffer(struct blkfront_info *info, int num) |
208 | { | |
209 | struct page *granted_page; | |
210 | struct grant *gnt_list_entry, *n; | |
211 | int i = 0; | |
212 | ||
213 | while(i < num) { | |
214 | gnt_list_entry = kzalloc(sizeof(struct grant), GFP_NOIO); | |
215 | if (!gnt_list_entry) | |
216 | goto out_of_memory; | |
217 | ||
bfe11d6d RPM |
218 | if (info->feature_persistent) { |
219 | granted_page = alloc_page(GFP_NOIO); | |
220 | if (!granted_page) { | |
221 | kfree(gnt_list_entry); | |
222 | goto out_of_memory; | |
223 | } | |
a7a6df22 | 224 | gnt_list_entry->page = granted_page; |
9c1e050c RPM |
225 | } |
226 | ||
9c1e050c | 227 | gnt_list_entry->gref = GRANT_INVALID_REF; |
bfe11d6d | 228 | list_add(&gnt_list_entry->node, &info->grants); |
9c1e050c RPM |
229 | i++; |
230 | } | |
231 | ||
232 | return 0; | |
233 | ||
234 | out_of_memory: | |
235 | list_for_each_entry_safe(gnt_list_entry, n, | |
bfe11d6d | 236 | &info->grants, node) { |
9c1e050c | 237 | list_del(&gnt_list_entry->node); |
bfe11d6d | 238 | if (info->feature_persistent) |
a7a6df22 | 239 | __free_page(gnt_list_entry->page); |
9c1e050c RPM |
240 | kfree(gnt_list_entry); |
241 | i--; | |
242 | } | |
243 | BUG_ON(i != 0); | |
244 | return -ENOMEM; | |
245 | } | |
246 | ||
247 | static struct grant *get_grant(grant_ref_t *gref_head, | |
a7a6df22 JG |
248 | struct page *page, |
249 | struct blkfront_info *info) | |
9c1e050c RPM |
250 | { |
251 | struct grant *gnt_list_entry; | |
0df4f266 | 252 | unsigned long buffer_gfn; |
9c1e050c | 253 | |
bfe11d6d RPM |
254 | BUG_ON(list_empty(&info->grants)); |
255 | gnt_list_entry = list_first_entry(&info->grants, struct grant, | |
9c1e050c RPM |
256 | node); |
257 | list_del(&gnt_list_entry->node); | |
258 | ||
259 | if (gnt_list_entry->gref != GRANT_INVALID_REF) { | |
260 | info->persistent_gnts_c--; | |
261 | return gnt_list_entry; | |
262 | } | |
263 | ||
264 | /* Assign a gref to this page */ | |
265 | gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); | |
266 | BUG_ON(gnt_list_entry->gref == -ENOSPC); | |
bfe11d6d | 267 | if (!info->feature_persistent) { |
a7a6df22 JG |
268 | BUG_ON(!page); |
269 | gnt_list_entry->page = page; | |
bfe11d6d | 270 | } |
a7a6df22 | 271 | buffer_gfn = xen_page_to_gfn(gnt_list_entry->page); |
9c1e050c RPM |
272 | gnttab_grant_foreign_access_ref(gnt_list_entry->gref, |
273 | info->xbdev->otherend_id, | |
0df4f266 | 274 | buffer_gfn, 0); |
9c1e050c RPM |
275 | return gnt_list_entry; |
276 | } | |
277 | ||
6878c32e KRW |
278 | static const char *op_name(int op) |
279 | { | |
280 | static const char *const names[] = { | |
281 | [BLKIF_OP_READ] = "read", | |
282 | [BLKIF_OP_WRITE] = "write", | |
283 | [BLKIF_OP_WRITE_BARRIER] = "barrier", | |
284 | [BLKIF_OP_FLUSH_DISKCACHE] = "flush", | |
285 | [BLKIF_OP_DISCARD] = "discard" }; | |
286 | ||
287 | if (op < 0 || op >= ARRAY_SIZE(names)) | |
288 | return "unknown"; | |
289 | ||
290 | if (!names[op]) | |
291 | return "reserved"; | |
292 | ||
293 | return names[op]; | |
294 | } | |
0e345826 JB |
295 | static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) |
296 | { | |
297 | unsigned int end = minor + nr; | |
298 | int rc; | |
299 | ||
300 | if (end > nr_minors) { | |
301 | unsigned long *bitmap, *old; | |
302 | ||
f094148a | 303 | bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap), |
0e345826 JB |
304 | GFP_KERNEL); |
305 | if (bitmap == NULL) | |
306 | return -ENOMEM; | |
307 | ||
308 | spin_lock(&minor_lock); | |
309 | if (end > nr_minors) { | |
310 | old = minors; | |
311 | memcpy(bitmap, minors, | |
312 | BITS_TO_LONGS(nr_minors) * sizeof(*bitmap)); | |
313 | minors = bitmap; | |
314 | nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG; | |
315 | } else | |
316 | old = bitmap; | |
317 | spin_unlock(&minor_lock); | |
318 | kfree(old); | |
319 | } | |
320 | ||
321 | spin_lock(&minor_lock); | |
322 | if (find_next_bit(minors, end, minor) >= end) { | |
34ae2e47 | 323 | bitmap_set(minors, minor, nr); |
0e345826 JB |
324 | rc = 0; |
325 | } else | |
326 | rc = -EBUSY; | |
327 | spin_unlock(&minor_lock); | |
328 | ||
329 | return rc; | |
330 | } | |
331 | ||
332 | static void xlbd_release_minors(unsigned int minor, unsigned int nr) | |
333 | { | |
334 | unsigned int end = minor + nr; | |
335 | ||
336 | BUG_ON(end > nr_minors); | |
337 | spin_lock(&minor_lock); | |
34ae2e47 | 338 | bitmap_clear(minors, minor, nr); |
0e345826 JB |
339 | spin_unlock(&minor_lock); |
340 | } | |
341 | ||
9f27ee59 JF |
342 | static void blkif_restart_queue_callback(void *arg) |
343 | { | |
344 | struct blkfront_info *info = (struct blkfront_info *)arg; | |
345 | schedule_work(&info->work); | |
346 | } | |
347 | ||
afe42d7d | 348 | static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg) |
597592d9 IC |
349 | { |
350 | /* We don't have real geometry info, but let's at least return | |
351 | values consistent with the size of the device */ | |
352 | sector_t nsect = get_capacity(bd->bd_disk); | |
353 | sector_t cylinders = nsect; | |
354 | ||
355 | hg->heads = 0xff; | |
356 | hg->sectors = 0x3f; | |
357 | sector_div(cylinders, hg->heads * hg->sectors); | |
358 | hg->cylinders = cylinders; | |
359 | if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect) | |
360 | hg->cylinders = 0xffff; | |
361 | return 0; | |
362 | } | |
363 | ||
a63c848b | 364 | static int blkif_ioctl(struct block_device *bdev, fmode_t mode, |
62aa0054 | 365 | unsigned command, unsigned long argument) |
440a01a7 | 366 | { |
a63c848b | 367 | struct blkfront_info *info = bdev->bd_disk->private_data; |
440a01a7 CL |
368 | int i; |
369 | ||
370 | dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n", | |
371 | command, (long)argument); | |
372 | ||
373 | switch (command) { | |
374 | case CDROMMULTISESSION: | |
375 | dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n"); | |
376 | for (i = 0; i < sizeof(struct cdrom_multisession); i++) | |
377 | if (put_user(0, (char __user *)(argument + i))) | |
378 | return -EFAULT; | |
379 | return 0; | |
380 | ||
381 | case CDROM_GET_CAPABILITY: { | |
382 | struct gendisk *gd = info->gd; | |
383 | if (gd->flags & GENHD_FL_CD) | |
384 | return 0; | |
385 | return -EINVAL; | |
386 | } | |
387 | ||
388 | default: | |
389 | /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n", | |
390 | command);*/ | |
391 | return -EINVAL; /* same return as native Linux */ | |
392 | } | |
393 | ||
394 | return 0; | |
395 | } | |
396 | ||
33204663 JG |
397 | static int blkif_queue_discard_req(struct request *req) |
398 | { | |
399 | struct blkfront_info *info = req->rq_disk->private_data; | |
400 | struct blkif_request *ring_req; | |
401 | unsigned long id; | |
402 | ||
403 | /* Fill out a communications ring structure. */ | |
404 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
405 | id = get_id_from_freelist(info); | |
406 | info->shadow[id].request = req; | |
407 | ||
408 | ring_req->operation = BLKIF_OP_DISCARD; | |
409 | ring_req->u.discard.nr_sectors = blk_rq_sectors(req); | |
410 | ring_req->u.discard.id = id; | |
411 | ring_req->u.discard.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
412 | if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard) | |
413 | ring_req->u.discard.flag = BLKIF_DISCARD_SECURE; | |
414 | else | |
415 | ring_req->u.discard.flag = 0; | |
416 | ||
417 | info->ring.req_prod_pvt++; | |
418 | ||
419 | /* Keep a private copy so we can reissue requests when recovering. */ | |
420 | info->shadow[id].req = *ring_req; | |
421 | ||
422 | return 0; | |
423 | } | |
424 | ||
425 | static int blkif_queue_rw_req(struct request *req) | |
9f27ee59 JF |
426 | { |
427 | struct blkfront_info *info = req->rq_disk->private_data; | |
9f27ee59 | 428 | struct blkif_request *ring_req; |
9f27ee59 JF |
429 | unsigned long id; |
430 | unsigned int fsect, lsect; | |
402b27f9 | 431 | int i, ref, n; |
80bfa2f6 | 432 | struct blkif_request_segment *segments = NULL; |
0a8704a5 RPM |
433 | |
434 | /* | |
435 | * Used to store if we are able to queue the request by just using | |
436 | * existing persistent grants, or if we have to get new grants, | |
437 | * as there are not sufficiently many free. | |
438 | */ | |
439 | bool new_persistent_gnts; | |
9f27ee59 | 440 | grant_ref_t gref_head; |
0a8704a5 | 441 | struct grant *gnt_list_entry = NULL; |
9e973e64 | 442 | struct scatterlist *sg; |
402b27f9 | 443 | int nseg, max_grefs; |
9f27ee59 | 444 | |
c47206e2 RPM |
445 | max_grefs = req->nr_phys_segments; |
446 | if (max_grefs > BLKIF_MAX_SEGMENTS_PER_REQUEST) | |
447 | /* | |
448 | * If we are using indirect segments we need to account | |
449 | * for the indirect grefs used in the request. | |
450 | */ | |
451 | max_grefs += INDIRECT_GREFS(req->nr_phys_segments); | |
402b27f9 RPM |
452 | |
453 | /* Check if we have enough grants to allocate a requests */ | |
454 | if (info->persistent_gnts_c < max_grefs) { | |
0a8704a5 RPM |
455 | new_persistent_gnts = 1; |
456 | if (gnttab_alloc_grant_references( | |
402b27f9 | 457 | max_grefs - info->persistent_gnts_c, |
0a8704a5 RPM |
458 | &gref_head) < 0) { |
459 | gnttab_request_free_callback( | |
460 | &info->callback, | |
461 | blkif_restart_queue_callback, | |
462 | info, | |
402b27f9 | 463 | max_grefs); |
0a8704a5 RPM |
464 | return 1; |
465 | } | |
466 | } else | |
467 | new_persistent_gnts = 0; | |
9f27ee59 JF |
468 | |
469 | /* Fill out a communications ring structure. */ | |
470 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
471 | id = get_id_from_freelist(info); | |
a945b980 | 472 | info->shadow[id].request = req; |
9f27ee59 | 473 | |
33204663 JG |
474 | BUG_ON(info->max_indirect_segments == 0 && |
475 | req->nr_phys_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
476 | BUG_ON(info->max_indirect_segments && | |
477 | req->nr_phys_segments > info->max_indirect_segments); | |
478 | nseg = blk_rq_map_sg(req->q, req, info->shadow[id].sg); | |
479 | ring_req->u.rw.id = id; | |
480 | if (nseg > BLKIF_MAX_SEGMENTS_PER_REQUEST) { | |
481 | /* | |
482 | * The indirect operation can only be a BLKIF_OP_READ or | |
483 | * BLKIF_OP_WRITE | |
484 | */ | |
485 | BUG_ON(req->cmd_flags & (REQ_FLUSH | REQ_FUA)); | |
486 | ring_req->operation = BLKIF_OP_INDIRECT; | |
487 | ring_req->u.indirect.indirect_op = rq_data_dir(req) ? | |
488 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
489 | ring_req->u.indirect.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
490 | ring_req->u.indirect.handle = info->handle; | |
491 | ring_req->u.indirect.nr_segments = nseg; | |
ed30bf31 | 492 | } else { |
33204663 JG |
493 | ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req); |
494 | ring_req->u.rw.handle = info->handle; | |
495 | ring_req->operation = rq_data_dir(req) ? | |
496 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
497 | if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) { | |
402b27f9 | 498 | /* |
33204663 JG |
499 | * Ideally we can do an unordered flush-to-disk. |
500 | * In case the backend onlysupports barriers, use that. | |
501 | * A barrier request a superset of FUA, so we can | |
502 | * implement it the same way. (It's also a FLUSH+FUA, | |
503 | * since it is guaranteed ordered WRT previous writes.) | |
402b27f9 | 504 | */ |
33204663 JG |
505 | switch (info->feature_flush & |
506 | ((REQ_FLUSH|REQ_FUA))) { | |
507 | case REQ_FLUSH|REQ_FUA: | |
508 | ring_req->operation = | |
509 | BLKIF_OP_WRITE_BARRIER; | |
510 | break; | |
511 | case REQ_FLUSH: | |
512 | ring_req->operation = | |
513 | BLKIF_OP_FLUSH_DISKCACHE; | |
514 | break; | |
515 | default: | |
516 | ring_req->operation = 0; | |
517 | } | |
518 | } | |
519 | ring_req->u.rw.nr_segments = nseg; | |
520 | } | |
521 | for_each_sg(info->shadow[id].sg, sg, nseg, i) { | |
522 | fsect = sg->offset >> 9; | |
523 | lsect = fsect + (sg->length >> 9) - 1; | |
524 | ||
525 | if ((ring_req->operation == BLKIF_OP_INDIRECT) && | |
526 | (i % SEGS_PER_INDIRECT_FRAME == 0)) { | |
a7a6df22 | 527 | struct page *uninitialized_var(page); |
33204663 JG |
528 | |
529 | if (segments) | |
530 | kunmap_atomic(segments); | |
531 | ||
532 | n = i / SEGS_PER_INDIRECT_FRAME; | |
533 | if (!info->feature_persistent) { | |
534 | struct page *indirect_page; | |
535 | ||
402b27f9 | 536 | /* |
33204663 JG |
537 | * Fetch a pre-allocated page to use for |
538 | * indirect grefs | |
402b27f9 | 539 | */ |
33204663 JG |
540 | BUG_ON(list_empty(&info->indirect_pages)); |
541 | indirect_page = list_first_entry(&info->indirect_pages, | |
542 | struct page, lru); | |
543 | list_del(&indirect_page->lru); | |
a7a6df22 | 544 | page = indirect_page; |
402b27f9 | 545 | } |
a7a6df22 | 546 | gnt_list_entry = get_grant(&gref_head, page, info); |
33204663 | 547 | info->shadow[id].indirect_grants[n] = gnt_list_entry; |
a7a6df22 | 548 | segments = kmap_atomic(gnt_list_entry->page); |
33204663 | 549 | ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref; |
402b27f9 | 550 | } |
402b27f9 | 551 | |
a7a6df22 | 552 | gnt_list_entry = get_grant(&gref_head, sg_page(sg), info); |
33204663 | 553 | ref = gnt_list_entry->gref; |
0a8704a5 | 554 | |
33204663 | 555 | info->shadow[id].grants_used[i] = gnt_list_entry; |
0a8704a5 | 556 | |
33204663 JG |
557 | if (rq_data_dir(req) && info->feature_persistent) { |
558 | char *bvec_data; | |
559 | void *shared_data; | |
0a8704a5 | 560 | |
33204663 | 561 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); |
0a8704a5 | 562 | |
a7a6df22 | 563 | shared_data = kmap_atomic(gnt_list_entry->page); |
33204663 | 564 | bvec_data = kmap_atomic(sg_page(sg)); |
0a8704a5 | 565 | |
33204663 JG |
566 | /* |
567 | * this does not wipe data stored outside the | |
568 | * range sg->offset..sg->offset+sg->length. | |
569 | * Therefore, blkback *could* see data from | |
570 | * previous requests. This is OK as long as | |
571 | * persistent grants are shared with just one | |
572 | * domain. It may need refactoring if this | |
573 | * changes | |
574 | */ | |
575 | memcpy(shared_data + sg->offset, | |
576 | bvec_data + sg->offset, | |
577 | sg->length); | |
0a8704a5 | 578 | |
33204663 JG |
579 | kunmap_atomic(bvec_data); |
580 | kunmap_atomic(shared_data); | |
581 | } | |
582 | if (ring_req->operation != BLKIF_OP_INDIRECT) { | |
583 | ring_req->u.rw.seg[i] = | |
80bfa2f6 | 584 | (struct blkif_request_segment) { |
33204663 JG |
585 | .gref = ref, |
586 | .first_sect = fsect, | |
587 | .last_sect = lsect }; | |
588 | } else { | |
589 | n = i % SEGS_PER_INDIRECT_FRAME; | |
590 | segments[n] = | |
591 | (struct blkif_request_segment) { | |
592 | .gref = ref, | |
593 | .first_sect = fsect, | |
594 | .last_sect = lsect }; | |
ed30bf31 | 595 | } |
9f27ee59 | 596 | } |
33204663 JG |
597 | if (segments) |
598 | kunmap_atomic(segments); | |
9f27ee59 JF |
599 | |
600 | info->ring.req_prod_pvt++; | |
601 | ||
602 | /* Keep a private copy so we can reissue requests when recovering. */ | |
603 | info->shadow[id].req = *ring_req; | |
604 | ||
0a8704a5 RPM |
605 | if (new_persistent_gnts) |
606 | gnttab_free_grant_references(gref_head); | |
9f27ee59 JF |
607 | |
608 | return 0; | |
609 | } | |
610 | ||
33204663 JG |
611 | /* |
612 | * Generate a Xen blkfront IO request from a blk layer request. Reads | |
613 | * and writes are handled as expected. | |
614 | * | |
615 | * @req: a request struct | |
616 | */ | |
617 | static int blkif_queue_request(struct request *req) | |
618 | { | |
619 | struct blkfront_info *info = req->rq_disk->private_data; | |
620 | ||
621 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) | |
622 | return 1; | |
623 | ||
624 | if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE))) | |
625 | return blkif_queue_discard_req(req); | |
626 | else | |
627 | return blkif_queue_rw_req(req); | |
628 | } | |
9f27ee59 JF |
629 | |
630 | static inline void flush_requests(struct blkfront_info *info) | |
631 | { | |
632 | int notify; | |
633 | ||
634 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify); | |
635 | ||
636 | if (notify) | |
637 | notify_remote_via_irq(info->irq); | |
638 | } | |
639 | ||
ad42d391 VK |
640 | static inline bool blkif_request_flush_invalid(struct request *req, |
641 | struct blkfront_info *info) | |
0f1ca65e AA |
642 | { |
643 | return ((req->cmd_type != REQ_TYPE_FS) || | |
ad42d391 VK |
644 | ((req->cmd_flags & REQ_FLUSH) && |
645 | !(info->feature_flush & REQ_FLUSH)) || | |
646 | ((req->cmd_flags & REQ_FUA) && | |
647 | !(info->feature_flush & REQ_FUA))); | |
0f1ca65e AA |
648 | } |
649 | ||
907c3eb1 BL |
650 | static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx, |
651 | const struct blk_mq_queue_data *qd) | |
9f27ee59 | 652 | { |
907c3eb1 | 653 | struct blkfront_info *info = qd->rq->rq_disk->private_data; |
9f27ee59 | 654 | |
907c3eb1 BL |
655 | blk_mq_start_request(qd->rq); |
656 | spin_lock_irq(&info->io_lock); | |
657 | if (RING_FULL(&info->ring)) | |
658 | goto out_busy; | |
9f27ee59 | 659 | |
907c3eb1 BL |
660 | if (blkif_request_flush_invalid(qd->rq, info)) |
661 | goto out_err; | |
296b2f6a | 662 | |
907c3eb1 BL |
663 | if (blkif_queue_request(qd->rq)) |
664 | goto out_busy; | |
296b2f6a | 665 | |
907c3eb1 BL |
666 | flush_requests(info); |
667 | spin_unlock_irq(&info->io_lock); | |
668 | return BLK_MQ_RQ_QUEUE_OK; | |
9f27ee59 | 669 | |
907c3eb1 BL |
670 | out_err: |
671 | spin_unlock_irq(&info->io_lock); | |
672 | return BLK_MQ_RQ_QUEUE_ERROR; | |
9f27ee59 | 673 | |
907c3eb1 BL |
674 | out_busy: |
675 | spin_unlock_irq(&info->io_lock); | |
676 | blk_mq_stop_hw_queue(hctx); | |
677 | return BLK_MQ_RQ_QUEUE_BUSY; | |
9f27ee59 JF |
678 | } |
679 | ||
907c3eb1 BL |
680 | static struct blk_mq_ops blkfront_mq_ops = { |
681 | .queue_rq = blkif_queue_rq, | |
682 | .map_queue = blk_mq_map_queue, | |
683 | }; | |
684 | ||
402b27f9 | 685 | static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, |
7c4d7d71 | 686 | unsigned int physical_sector_size, |
402b27f9 | 687 | unsigned int segments) |
9f27ee59 | 688 | { |
165125e1 | 689 | struct request_queue *rq; |
ed30bf31 | 690 | struct blkfront_info *info = gd->private_data; |
9f27ee59 | 691 | |
907c3eb1 BL |
692 | memset(&info->tag_set, 0, sizeof(info->tag_set)); |
693 | info->tag_set.ops = &blkfront_mq_ops; | |
694 | info->tag_set.nr_hw_queues = 1; | |
695 | info->tag_set.queue_depth = BLK_RING_SIZE(info); | |
696 | info->tag_set.numa_node = NUMA_NO_NODE; | |
697 | info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; | |
698 | info->tag_set.cmd_size = 0; | |
699 | info->tag_set.driver_data = info; | |
700 | ||
701 | if (blk_mq_alloc_tag_set(&info->tag_set)) | |
9f27ee59 | 702 | return -1; |
907c3eb1 BL |
703 | rq = blk_mq_init_queue(&info->tag_set); |
704 | if (IS_ERR(rq)) { | |
705 | blk_mq_free_tag_set(&info->tag_set); | |
706 | return -1; | |
707 | } | |
9f27ee59 | 708 | |
66d352e1 | 709 | queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); |
9f27ee59 | 710 | |
ed30bf31 LD |
711 | if (info->feature_discard) { |
712 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, rq); | |
713 | blk_queue_max_discard_sectors(rq, get_capacity(gd)); | |
714 | rq->limits.discard_granularity = info->discard_granularity; | |
715 | rq->limits.discard_alignment = info->discard_alignment; | |
5ea42986 KRW |
716 | if (info->feature_secdiscard) |
717 | queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, rq); | |
ed30bf31 LD |
718 | } |
719 | ||
9f27ee59 | 720 | /* Hard sector size and max sectors impersonate the equiv. hardware. */ |
e1defc4f | 721 | blk_queue_logical_block_size(rq, sector_size); |
7c4d7d71 | 722 | blk_queue_physical_block_size(rq, physical_sector_size); |
294caaf2 | 723 | blk_queue_max_hw_sectors(rq, (segments * PAGE_SIZE) / 512); |
9f27ee59 JF |
724 | |
725 | /* Each segment in a request is up to an aligned page in size. */ | |
726 | blk_queue_segment_boundary(rq, PAGE_SIZE - 1); | |
727 | blk_queue_max_segment_size(rq, PAGE_SIZE); | |
728 | ||
729 | /* Ensure a merged request will fit in a single I/O ring slot. */ | |
402b27f9 | 730 | blk_queue_max_segments(rq, segments); |
9f27ee59 JF |
731 | |
732 | /* Make sure buffer addresses are sector-aligned. */ | |
733 | blk_queue_dma_alignment(rq, 511); | |
734 | ||
1c91fe1a IC |
735 | /* Make sure we don't use bounce buffers. */ |
736 | blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY); | |
737 | ||
9f27ee59 JF |
738 | gd->queue = rq; |
739 | ||
740 | return 0; | |
741 | } | |
742 | ||
fdf9b965 VK |
743 | static const char *flush_info(unsigned int feature_flush) |
744 | { | |
745 | switch (feature_flush & ((REQ_FLUSH | REQ_FUA))) { | |
746 | case REQ_FLUSH|REQ_FUA: | |
747 | return "barrier: enabled;"; | |
748 | case REQ_FLUSH: | |
749 | return "flush diskcache: enabled;"; | |
750 | default: | |
751 | return "barrier or flush: disabled;"; | |
752 | } | |
753 | } | |
9f27ee59 | 754 | |
4913efe4 | 755 | static void xlvbd_flush(struct blkfront_info *info) |
9f27ee59 | 756 | { |
4913efe4 | 757 | blk_queue_flush(info->rq, info->feature_flush); |
fdf9b965 VK |
758 | pr_info("blkfront: %s: %s %s %s %s %s\n", |
759 | info->gd->disk_name, flush_info(info->feature_flush), | |
760 | "persistent grants:", info->feature_persistent ? | |
761 | "enabled;" : "disabled;", "indirect descriptors:", | |
762 | info->max_indirect_segments ? "enabled;" : "disabled;"); | |
9f27ee59 JF |
763 | } |
764 | ||
c80a4209 SS |
765 | static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) |
766 | { | |
767 | int major; | |
768 | major = BLKIF_MAJOR(vdevice); | |
769 | *minor = BLKIF_MINOR(vdevice); | |
770 | switch (major) { | |
771 | case XEN_IDE0_MAJOR: | |
772 | *offset = (*minor / 64) + EMULATED_HD_DISK_NAME_OFFSET; | |
773 | *minor = ((*minor / 64) * PARTS_PER_DISK) + | |
774 | EMULATED_HD_DISK_MINOR_OFFSET; | |
775 | break; | |
776 | case XEN_IDE1_MAJOR: | |
777 | *offset = (*minor / 64) + 2 + EMULATED_HD_DISK_NAME_OFFSET; | |
778 | *minor = (((*minor / 64) + 2) * PARTS_PER_DISK) + | |
779 | EMULATED_HD_DISK_MINOR_OFFSET; | |
780 | break; | |
781 | case XEN_SCSI_DISK0_MAJOR: | |
782 | *offset = (*minor / PARTS_PER_DISK) + EMULATED_SD_DISK_NAME_OFFSET; | |
783 | *minor = *minor + EMULATED_SD_DISK_MINOR_OFFSET; | |
784 | break; | |
785 | case XEN_SCSI_DISK1_MAJOR: | |
786 | case XEN_SCSI_DISK2_MAJOR: | |
787 | case XEN_SCSI_DISK3_MAJOR: | |
788 | case XEN_SCSI_DISK4_MAJOR: | |
789 | case XEN_SCSI_DISK5_MAJOR: | |
790 | case XEN_SCSI_DISK6_MAJOR: | |
791 | case XEN_SCSI_DISK7_MAJOR: | |
792 | *offset = (*minor / PARTS_PER_DISK) + | |
793 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16) + | |
794 | EMULATED_SD_DISK_NAME_OFFSET; | |
795 | *minor = *minor + | |
796 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16 * PARTS_PER_DISK) + | |
797 | EMULATED_SD_DISK_MINOR_OFFSET; | |
798 | break; | |
799 | case XEN_SCSI_DISK8_MAJOR: | |
800 | case XEN_SCSI_DISK9_MAJOR: | |
801 | case XEN_SCSI_DISK10_MAJOR: | |
802 | case XEN_SCSI_DISK11_MAJOR: | |
803 | case XEN_SCSI_DISK12_MAJOR: | |
804 | case XEN_SCSI_DISK13_MAJOR: | |
805 | case XEN_SCSI_DISK14_MAJOR: | |
806 | case XEN_SCSI_DISK15_MAJOR: | |
807 | *offset = (*minor / PARTS_PER_DISK) + | |
808 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16) + | |
809 | EMULATED_SD_DISK_NAME_OFFSET; | |
810 | *minor = *minor + | |
811 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16 * PARTS_PER_DISK) + | |
812 | EMULATED_SD_DISK_MINOR_OFFSET; | |
813 | break; | |
814 | case XENVBD_MAJOR: | |
815 | *offset = *minor / PARTS_PER_DISK; | |
816 | break; | |
817 | default: | |
818 | printk(KERN_WARNING "blkfront: your disk configuration is " | |
819 | "incorrect, please use an xvd device instead\n"); | |
820 | return -ENODEV; | |
821 | } | |
822 | return 0; | |
823 | } | |
9f27ee59 | 824 | |
e77c78c0 JB |
825 | static char *encode_disk_name(char *ptr, unsigned int n) |
826 | { | |
827 | if (n >= 26) | |
828 | ptr = encode_disk_name(ptr, n / 26 - 1); | |
829 | *ptr = 'a' + n % 26; | |
830 | return ptr + 1; | |
831 | } | |
832 | ||
9246b5f0 CL |
833 | static int xlvbd_alloc_gendisk(blkif_sector_t capacity, |
834 | struct blkfront_info *info, | |
7c4d7d71 SB |
835 | u16 vdisk_info, u16 sector_size, |
836 | unsigned int physical_sector_size) | |
9f27ee59 JF |
837 | { |
838 | struct gendisk *gd; | |
839 | int nr_minors = 1; | |
c80a4209 | 840 | int err; |
9246b5f0 CL |
841 | unsigned int offset; |
842 | int minor; | |
843 | int nr_parts; | |
e77c78c0 | 844 | char *ptr; |
9f27ee59 JF |
845 | |
846 | BUG_ON(info->gd != NULL); | |
847 | BUG_ON(info->rq != NULL); | |
848 | ||
9246b5f0 CL |
849 | if ((info->vdevice>>EXT_SHIFT) > 1) { |
850 | /* this is above the extended range; something is wrong */ | |
851 | printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice); | |
852 | return -ENODEV; | |
853 | } | |
854 | ||
855 | if (!VDEV_IS_EXTENDED(info->vdevice)) { | |
c80a4209 SS |
856 | err = xen_translate_vdev(info->vdevice, &minor, &offset); |
857 | if (err) | |
858 | return err; | |
859 | nr_parts = PARTS_PER_DISK; | |
9246b5f0 CL |
860 | } else { |
861 | minor = BLKIF_MINOR_EXT(info->vdevice); | |
862 | nr_parts = PARTS_PER_EXT_DISK; | |
c80a4209 | 863 | offset = minor / nr_parts; |
89153b5c | 864 | if (xen_hvm_domain() && offset < EMULATED_HD_DISK_NAME_OFFSET + 4) |
c80a4209 SS |
865 | printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with " |
866 | "emulated IDE disks,\n\t choose an xvd device name" | |
867 | "from xvde on\n", info->vdevice); | |
9246b5f0 | 868 | } |
e77c78c0 JB |
869 | if (minor >> MINORBITS) { |
870 | pr_warn("blkfront: %#x's minor (%#x) out of range; ignoring\n", | |
871 | info->vdevice, minor); | |
872 | return -ENODEV; | |
873 | } | |
9246b5f0 CL |
874 | |
875 | if ((minor % nr_parts) == 0) | |
876 | nr_minors = nr_parts; | |
9f27ee59 | 877 | |
0e345826 JB |
878 | err = xlbd_reserve_minors(minor, nr_minors); |
879 | if (err) | |
880 | goto out; | |
881 | err = -ENODEV; | |
882 | ||
9f27ee59 JF |
883 | gd = alloc_disk(nr_minors); |
884 | if (gd == NULL) | |
0e345826 | 885 | goto release; |
9f27ee59 | 886 | |
e77c78c0 JB |
887 | strcpy(gd->disk_name, DEV_NAME); |
888 | ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset); | |
889 | BUG_ON(ptr >= gd->disk_name + DISK_NAME_LEN); | |
890 | if (nr_minors > 1) | |
891 | *ptr = 0; | |
892 | else | |
893 | snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr, | |
894 | "%d", minor & (nr_parts - 1)); | |
9f27ee59 JF |
895 | |
896 | gd->major = XENVBD_MAJOR; | |
897 | gd->first_minor = minor; | |
898 | gd->fops = &xlvbd_block_fops; | |
899 | gd->private_data = info; | |
900 | gd->driverfs_dev = &(info->xbdev->dev); | |
901 | set_capacity(gd, capacity); | |
902 | ||
7c4d7d71 | 903 | if (xlvbd_init_blk_queue(gd, sector_size, physical_sector_size, |
402b27f9 RPM |
904 | info->max_indirect_segments ? : |
905 | BLKIF_MAX_SEGMENTS_PER_REQUEST)) { | |
9f27ee59 | 906 | del_gendisk(gd); |
0e345826 | 907 | goto release; |
9f27ee59 JF |
908 | } |
909 | ||
910 | info->rq = gd->queue; | |
911 | info->gd = gd; | |
912 | ||
4913efe4 | 913 | xlvbd_flush(info); |
9f27ee59 JF |
914 | |
915 | if (vdisk_info & VDISK_READONLY) | |
916 | set_disk_ro(gd, 1); | |
917 | ||
918 | if (vdisk_info & VDISK_REMOVABLE) | |
919 | gd->flags |= GENHD_FL_REMOVABLE; | |
920 | ||
921 | if (vdisk_info & VDISK_CDROM) | |
922 | gd->flags |= GENHD_FL_CD; | |
923 | ||
924 | return 0; | |
925 | ||
0e345826 JB |
926 | release: |
927 | xlbd_release_minors(minor, nr_minors); | |
9f27ee59 JF |
928 | out: |
929 | return err; | |
930 | } | |
931 | ||
a66b5aeb DS |
932 | static void xlvbd_release_gendisk(struct blkfront_info *info) |
933 | { | |
934 | unsigned int minor, nr_minors; | |
a66b5aeb DS |
935 | |
936 | if (info->rq == NULL) | |
937 | return; | |
938 | ||
a66b5aeb | 939 | /* No more blkif_request(). */ |
907c3eb1 | 940 | blk_mq_stop_hw_queues(info->rq); |
a66b5aeb DS |
941 | |
942 | /* No more gnttab callback work. */ | |
943 | gnttab_cancel_free_callback(&info->callback); | |
a66b5aeb DS |
944 | |
945 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 946 | flush_work(&info->work); |
a66b5aeb DS |
947 | |
948 | del_gendisk(info->gd); | |
949 | ||
950 | minor = info->gd->first_minor; | |
951 | nr_minors = info->gd->minors; | |
952 | xlbd_release_minors(minor, nr_minors); | |
953 | ||
954 | blk_cleanup_queue(info->rq); | |
907c3eb1 | 955 | blk_mq_free_tag_set(&info->tag_set); |
a66b5aeb DS |
956 | info->rq = NULL; |
957 | ||
958 | put_disk(info->gd); | |
959 | info->gd = NULL; | |
960 | } | |
961 | ||
907c3eb1 | 962 | /* Must be called with io_lock holded */ |
9f27ee59 JF |
963 | static void kick_pending_request_queues(struct blkfront_info *info) |
964 | { | |
907c3eb1 BL |
965 | if (!RING_FULL(&info->ring)) |
966 | blk_mq_start_stopped_hw_queues(info->rq, true); | |
9f27ee59 JF |
967 | } |
968 | ||
969 | static void blkif_restart_queue(struct work_struct *work) | |
970 | { | |
971 | struct blkfront_info *info = container_of(work, struct blkfront_info, work); | |
972 | ||
3467811e | 973 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
974 | if (info->connected == BLKIF_STATE_CONNECTED) |
975 | kick_pending_request_queues(info); | |
3467811e | 976 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
977 | } |
978 | ||
979 | static void blkif_free(struct blkfront_info *info, int suspend) | |
980 | { | |
155b7edb RPM |
981 | struct grant *persistent_gnt; |
982 | struct grant *n; | |
402b27f9 | 983 | int i, j, segs; |
0a8704a5 | 984 | |
9f27ee59 | 985 | /* Prevent new requests being issued until we fix things up. */ |
3467811e | 986 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
987 | info->connected = suspend ? |
988 | BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; | |
989 | /* No more blkif_request(). */ | |
990 | if (info->rq) | |
907c3eb1 | 991 | blk_mq_stop_hw_queues(info->rq); |
0a8704a5 RPM |
992 | |
993 | /* Remove all persistent grants */ | |
bfe11d6d | 994 | if (!list_empty(&info->grants)) { |
155b7edb | 995 | list_for_each_entry_safe(persistent_gnt, n, |
bfe11d6d | 996 | &info->grants, node) { |
155b7edb | 997 | list_del(&persistent_gnt->node); |
9c1e050c RPM |
998 | if (persistent_gnt->gref != GRANT_INVALID_REF) { |
999 | gnttab_end_foreign_access(persistent_gnt->gref, | |
1000 | 0, 0UL); | |
1001 | info->persistent_gnts_c--; | |
1002 | } | |
bfe11d6d | 1003 | if (info->feature_persistent) |
a7a6df22 | 1004 | __free_page(persistent_gnt->page); |
155b7edb | 1005 | kfree(persistent_gnt); |
0a8704a5 | 1006 | } |
0a8704a5 | 1007 | } |
9c1e050c | 1008 | BUG_ON(info->persistent_gnts_c != 0); |
0a8704a5 | 1009 | |
bfe11d6d RPM |
1010 | /* |
1011 | * Remove indirect pages, this only happens when using indirect | |
1012 | * descriptors but not persistent grants | |
1013 | */ | |
1014 | if (!list_empty(&info->indirect_pages)) { | |
1015 | struct page *indirect_page, *n; | |
1016 | ||
1017 | BUG_ON(info->feature_persistent); | |
1018 | list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) { | |
1019 | list_del(&indirect_page->lru); | |
1020 | __free_page(indirect_page); | |
1021 | } | |
1022 | } | |
1023 | ||
86839c56 | 1024 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1025 | /* |
1026 | * Clear persistent grants present in requests already | |
1027 | * on the shared ring | |
1028 | */ | |
1029 | if (!info->shadow[i].request) | |
1030 | goto free_shadow; | |
1031 | ||
1032 | segs = info->shadow[i].req.operation == BLKIF_OP_INDIRECT ? | |
1033 | info->shadow[i].req.u.indirect.nr_segments : | |
1034 | info->shadow[i].req.u.rw.nr_segments; | |
1035 | for (j = 0; j < segs; j++) { | |
1036 | persistent_gnt = info->shadow[i].grants_used[j]; | |
1037 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); | |
bfe11d6d | 1038 | if (info->feature_persistent) |
a7a6df22 | 1039 | __free_page(persistent_gnt->page); |
402b27f9 RPM |
1040 | kfree(persistent_gnt); |
1041 | } | |
1042 | ||
1043 | if (info->shadow[i].req.operation != BLKIF_OP_INDIRECT) | |
1044 | /* | |
1045 | * If this is not an indirect operation don't try to | |
1046 | * free indirect segments | |
1047 | */ | |
1048 | goto free_shadow; | |
1049 | ||
1050 | for (j = 0; j < INDIRECT_GREFS(segs); j++) { | |
1051 | persistent_gnt = info->shadow[i].indirect_grants[j]; | |
1052 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); | |
a7a6df22 | 1053 | __free_page(persistent_gnt->page); |
402b27f9 RPM |
1054 | kfree(persistent_gnt); |
1055 | } | |
1056 | ||
1057 | free_shadow: | |
1058 | kfree(info->shadow[i].grants_used); | |
1059 | info->shadow[i].grants_used = NULL; | |
1060 | kfree(info->shadow[i].indirect_grants); | |
1061 | info->shadow[i].indirect_grants = NULL; | |
b7649158 RPM |
1062 | kfree(info->shadow[i].sg); |
1063 | info->shadow[i].sg = NULL; | |
402b27f9 RPM |
1064 | } |
1065 | ||
9f27ee59 JF |
1066 | /* No more gnttab callback work. */ |
1067 | gnttab_cancel_free_callback(&info->callback); | |
3467811e | 1068 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1069 | |
1070 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 1071 | flush_work(&info->work); |
9f27ee59 JF |
1072 | |
1073 | /* Free resources associated with old device channel. */ | |
86839c56 BL |
1074 | for (i = 0; i < info->nr_ring_pages; i++) { |
1075 | if (info->ring_ref[i] != GRANT_INVALID_REF) { | |
1076 | gnttab_end_foreign_access(info->ring_ref[i], 0, 0); | |
1077 | info->ring_ref[i] = GRANT_INVALID_REF; | |
1078 | } | |
9f27ee59 | 1079 | } |
86839c56 BL |
1080 | free_pages((unsigned long)info->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE)); |
1081 | info->ring.sring = NULL; | |
1082 | ||
9f27ee59 JF |
1083 | if (info->irq) |
1084 | unbind_from_irqhandler(info->irq, info); | |
1085 | info->evtchn = info->irq = 0; | |
1086 | ||
1087 | } | |
1088 | ||
0a8704a5 RPM |
1089 | static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info, |
1090 | struct blkif_response *bret) | |
9f27ee59 | 1091 | { |
d62f6918 | 1092 | int i = 0; |
b7649158 | 1093 | struct scatterlist *sg; |
0a8704a5 RPM |
1094 | char *bvec_data; |
1095 | void *shared_data; | |
402b27f9 RPM |
1096 | int nseg; |
1097 | ||
1098 | nseg = s->req.operation == BLKIF_OP_INDIRECT ? | |
1099 | s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments; | |
0a8704a5 | 1100 | |
bfe11d6d | 1101 | if (bret->operation == BLKIF_OP_READ && info->feature_persistent) { |
b7649158 RPM |
1102 | for_each_sg(s->sg, sg, nseg, i) { |
1103 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); | |
a7a6df22 | 1104 | shared_data = kmap_atomic(s->grants_used[i]->page); |
b7649158 RPM |
1105 | bvec_data = kmap_atomic(sg_page(sg)); |
1106 | memcpy(bvec_data + sg->offset, | |
1107 | shared_data + sg->offset, | |
1108 | sg->length); | |
1109 | kunmap_atomic(bvec_data); | |
0a8704a5 | 1110 | kunmap_atomic(shared_data); |
0a8704a5 RPM |
1111 | } |
1112 | } | |
1113 | /* Add the persistent grant into the list of free grants */ | |
402b27f9 | 1114 | for (i = 0; i < nseg; i++) { |
fbe363c4 RPM |
1115 | if (gnttab_query_foreign_access(s->grants_used[i]->gref)) { |
1116 | /* | |
1117 | * If the grant is still mapped by the backend (the | |
1118 | * backend has chosen to make this grant persistent) | |
1119 | * we add it at the head of the list, so it will be | |
1120 | * reused first. | |
1121 | */ | |
bfe11d6d RPM |
1122 | if (!info->feature_persistent) |
1123 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1124 | s->grants_used[i]->gref); | |
1125 | list_add(&s->grants_used[i]->node, &info->grants); | |
fbe363c4 RPM |
1126 | info->persistent_gnts_c++; |
1127 | } else { | |
1128 | /* | |
1129 | * If the grant is not mapped by the backend we end the | |
1130 | * foreign access and add it to the tail of the list, | |
1131 | * so it will not be picked again unless we run out of | |
1132 | * persistent grants. | |
1133 | */ | |
1134 | gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL); | |
1135 | s->grants_used[i]->gref = GRANT_INVALID_REF; | |
bfe11d6d | 1136 | list_add_tail(&s->grants_used[i]->node, &info->grants); |
fbe363c4 | 1137 | } |
0a8704a5 | 1138 | } |
402b27f9 RPM |
1139 | if (s->req.operation == BLKIF_OP_INDIRECT) { |
1140 | for (i = 0; i < INDIRECT_GREFS(nseg); i++) { | |
fbe363c4 | 1141 | if (gnttab_query_foreign_access(s->indirect_grants[i]->gref)) { |
bfe11d6d RPM |
1142 | if (!info->feature_persistent) |
1143 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1144 | s->indirect_grants[i]->gref); | |
1145 | list_add(&s->indirect_grants[i]->node, &info->grants); | |
fbe363c4 RPM |
1146 | info->persistent_gnts_c++; |
1147 | } else { | |
bfe11d6d RPM |
1148 | struct page *indirect_page; |
1149 | ||
fbe363c4 | 1150 | gnttab_end_foreign_access(s->indirect_grants[i]->gref, 0, 0UL); |
bfe11d6d RPM |
1151 | /* |
1152 | * Add the used indirect page back to the list of | |
1153 | * available pages for indirect grefs. | |
1154 | */ | |
7b076750 | 1155 | if (!info->feature_persistent) { |
a7a6df22 | 1156 | indirect_page = s->indirect_grants[i]->page; |
7b076750 BL |
1157 | list_add(&indirect_page->lru, &info->indirect_pages); |
1158 | } | |
fbe363c4 | 1159 | s->indirect_grants[i]->gref = GRANT_INVALID_REF; |
bfe11d6d | 1160 | list_add_tail(&s->indirect_grants[i]->node, &info->grants); |
fbe363c4 | 1161 | } |
402b27f9 RPM |
1162 | } |
1163 | } | |
9f27ee59 JF |
1164 | } |
1165 | ||
1166 | static irqreturn_t blkif_interrupt(int irq, void *dev_id) | |
1167 | { | |
1168 | struct request *req; | |
1169 | struct blkif_response *bret; | |
1170 | RING_IDX i, rp; | |
1171 | unsigned long flags; | |
1172 | struct blkfront_info *info = (struct blkfront_info *)dev_id; | |
f4829a9b | 1173 | int error; |
9f27ee59 | 1174 | |
3467811e | 1175 | spin_lock_irqsave(&info->io_lock, flags); |
9f27ee59 JF |
1176 | |
1177 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { | |
3467811e | 1178 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
1179 | return IRQ_HANDLED; |
1180 | } | |
1181 | ||
1182 | again: | |
1183 | rp = info->ring.sring->rsp_prod; | |
1184 | rmb(); /* Ensure we see queued responses up to 'rp'. */ | |
1185 | ||
1186 | for (i = info->ring.rsp_cons; i != rp; i++) { | |
1187 | unsigned long id; | |
9f27ee59 JF |
1188 | |
1189 | bret = RING_GET_RESPONSE(&info->ring, i); | |
1190 | id = bret->id; | |
6878c32e KRW |
1191 | /* |
1192 | * The backend has messed up and given us an id that we would | |
1193 | * never have given to it (we stamp it up to BLK_RING_SIZE - | |
1194 | * look in get_id_from_freelist. | |
1195 | */ | |
86839c56 | 1196 | if (id >= BLK_RING_SIZE(info)) { |
6878c32e KRW |
1197 | WARN(1, "%s: response to %s has incorrect id (%ld)\n", |
1198 | info->gd->disk_name, op_name(bret->operation), id); | |
1199 | /* We can't safely get the 'struct request' as | |
1200 | * the id is busted. */ | |
1201 | continue; | |
1202 | } | |
a945b980 | 1203 | req = info->shadow[id].request; |
9f27ee59 | 1204 | |
5ea42986 | 1205 | if (bret->operation != BLKIF_OP_DISCARD) |
0a8704a5 | 1206 | blkif_completion(&info->shadow[id], info, bret); |
9f27ee59 | 1207 | |
6878c32e KRW |
1208 | if (add_id_to_freelist(info, id)) { |
1209 | WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n", | |
1210 | info->gd->disk_name, op_name(bret->operation), id); | |
1211 | continue; | |
1212 | } | |
9f27ee59 | 1213 | |
f4829a9b | 1214 | error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO; |
9f27ee59 | 1215 | switch (bret->operation) { |
ed30bf31 LD |
1216 | case BLKIF_OP_DISCARD: |
1217 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
1218 | struct request_queue *rq = info->rq; | |
6878c32e KRW |
1219 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1220 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1221 | error = -EOPNOTSUPP; |
ed30bf31 | 1222 | info->feature_discard = 0; |
5ea42986 | 1223 | info->feature_secdiscard = 0; |
ed30bf31 | 1224 | queue_flag_clear(QUEUE_FLAG_DISCARD, rq); |
5ea42986 | 1225 | queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq); |
ed30bf31 | 1226 | } |
f4829a9b | 1227 | blk_mq_complete_request(req, error); |
ed30bf31 | 1228 | break; |
edf6ef59 | 1229 | case BLKIF_OP_FLUSH_DISKCACHE: |
9f27ee59 JF |
1230 | case BLKIF_OP_WRITE_BARRIER: |
1231 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
6878c32e KRW |
1232 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1233 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1234 | error = -EOPNOTSUPP; |
dcb8baec JF |
1235 | } |
1236 | if (unlikely(bret->status == BLKIF_RSP_ERROR && | |
97e36834 | 1237 | info->shadow[id].req.u.rw.nr_segments == 0)) { |
6878c32e KRW |
1238 | printk(KERN_WARNING "blkfront: %s: empty %s op failed\n", |
1239 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1240 | error = -EOPNOTSUPP; |
dcb8baec | 1241 | } |
f4829a9b CH |
1242 | if (unlikely(error)) { |
1243 | if (error == -EOPNOTSUPP) | |
1244 | error = 0; | |
4913efe4 TH |
1245 | info->feature_flush = 0; |
1246 | xlvbd_flush(info); | |
9f27ee59 JF |
1247 | } |
1248 | /* fall through */ | |
1249 | case BLKIF_OP_READ: | |
1250 | case BLKIF_OP_WRITE: | |
1251 | if (unlikely(bret->status != BLKIF_RSP_OKAY)) | |
1252 | dev_dbg(&info->xbdev->dev, "Bad return from blkdev data " | |
1253 | "request: %x\n", bret->status); | |
1254 | ||
f4829a9b | 1255 | blk_mq_complete_request(req, error); |
9f27ee59 JF |
1256 | break; |
1257 | default: | |
1258 | BUG(); | |
1259 | } | |
1260 | } | |
1261 | ||
1262 | info->ring.rsp_cons = i; | |
1263 | ||
1264 | if (i != info->ring.req_prod_pvt) { | |
1265 | int more_to_do; | |
1266 | RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do); | |
1267 | if (more_to_do) | |
1268 | goto again; | |
1269 | } else | |
1270 | info->ring.sring->rsp_event = i + 1; | |
1271 | ||
1272 | kick_pending_request_queues(info); | |
1273 | ||
3467811e | 1274 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
1275 | |
1276 | return IRQ_HANDLED; | |
1277 | } | |
1278 | ||
1279 | ||
1280 | static int setup_blkring(struct xenbus_device *dev, | |
1281 | struct blkfront_info *info) | |
1282 | { | |
1283 | struct blkif_sring *sring; | |
86839c56 BL |
1284 | int err, i; |
1285 | unsigned long ring_size = info->nr_ring_pages * PAGE_SIZE; | |
1286 | grant_ref_t gref[XENBUS_MAX_RING_PAGES]; | |
9f27ee59 | 1287 | |
86839c56 BL |
1288 | for (i = 0; i < info->nr_ring_pages; i++) |
1289 | info->ring_ref[i] = GRANT_INVALID_REF; | |
9f27ee59 | 1290 | |
86839c56 BL |
1291 | sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH, |
1292 | get_order(ring_size)); | |
9f27ee59 JF |
1293 | if (!sring) { |
1294 | xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); | |
1295 | return -ENOMEM; | |
1296 | } | |
1297 | SHARED_RING_INIT(sring); | |
86839c56 | 1298 | FRONT_RING_INIT(&info->ring, sring, ring_size); |
9e973e64 | 1299 | |
86839c56 | 1300 | err = xenbus_grant_ring(dev, info->ring.sring, info->nr_ring_pages, gref); |
9f27ee59 | 1301 | if (err < 0) { |
86839c56 | 1302 | free_pages((unsigned long)sring, get_order(ring_size)); |
9f27ee59 JF |
1303 | info->ring.sring = NULL; |
1304 | goto fail; | |
1305 | } | |
86839c56 BL |
1306 | for (i = 0; i < info->nr_ring_pages; i++) |
1307 | info->ring_ref[i] = gref[i]; | |
9f27ee59 JF |
1308 | |
1309 | err = xenbus_alloc_evtchn(dev, &info->evtchn); | |
1310 | if (err) | |
1311 | goto fail; | |
1312 | ||
89c30f16 TT |
1313 | err = bind_evtchn_to_irqhandler(info->evtchn, blkif_interrupt, 0, |
1314 | "blkif", info); | |
9f27ee59 JF |
1315 | if (err <= 0) { |
1316 | xenbus_dev_fatal(dev, err, | |
1317 | "bind_evtchn_to_irqhandler failed"); | |
1318 | goto fail; | |
1319 | } | |
1320 | info->irq = err; | |
1321 | ||
1322 | return 0; | |
1323 | fail: | |
1324 | blkif_free(info, 0); | |
1325 | return err; | |
1326 | } | |
1327 | ||
1328 | ||
1329 | /* Common code used when first setting up, and when resuming. */ | |
203fd61f | 1330 | static int talk_to_blkback(struct xenbus_device *dev, |
9f27ee59 JF |
1331 | struct blkfront_info *info) |
1332 | { | |
1333 | const char *message = NULL; | |
1334 | struct xenbus_transaction xbt; | |
86839c56 BL |
1335 | int err, i; |
1336 | unsigned int max_page_order = 0; | |
1337 | unsigned int ring_page_order = 0; | |
1338 | ||
1339 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1340 | "max-ring-page-order", "%u", &max_page_order); | |
1341 | if (err != 1) | |
1342 | info->nr_ring_pages = 1; | |
1343 | else { | |
1344 | ring_page_order = min(xen_blkif_max_ring_order, max_page_order); | |
1345 | info->nr_ring_pages = 1 << ring_page_order; | |
1346 | } | |
9f27ee59 JF |
1347 | |
1348 | /* Create shared ring, alloc event channel. */ | |
1349 | err = setup_blkring(dev, info); | |
1350 | if (err) | |
1351 | goto out; | |
1352 | ||
1353 | again: | |
1354 | err = xenbus_transaction_start(&xbt); | |
1355 | if (err) { | |
1356 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
1357 | goto destroy_blkring; | |
1358 | } | |
1359 | ||
86839c56 BL |
1360 | if (info->nr_ring_pages == 1) { |
1361 | err = xenbus_printf(xbt, dev->nodename, | |
1362 | "ring-ref", "%u", info->ring_ref[0]); | |
1363 | if (err) { | |
1364 | message = "writing ring-ref"; | |
1365 | goto abort_transaction; | |
1366 | } | |
1367 | } else { | |
1368 | err = xenbus_printf(xbt, dev->nodename, | |
1369 | "ring-page-order", "%u", ring_page_order); | |
1370 | if (err) { | |
1371 | message = "writing ring-page-order"; | |
1372 | goto abort_transaction; | |
1373 | } | |
1374 | ||
1375 | for (i = 0; i < info->nr_ring_pages; i++) { | |
1376 | char ring_ref_name[RINGREF_NAME_LEN]; | |
1377 | ||
1378 | snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); | |
1379 | err = xenbus_printf(xbt, dev->nodename, ring_ref_name, | |
1380 | "%u", info->ring_ref[i]); | |
1381 | if (err) { | |
1382 | message = "writing ring-ref"; | |
1383 | goto abort_transaction; | |
1384 | } | |
1385 | } | |
9f27ee59 JF |
1386 | } |
1387 | err = xenbus_printf(xbt, dev->nodename, | |
1388 | "event-channel", "%u", info->evtchn); | |
1389 | if (err) { | |
1390 | message = "writing event-channel"; | |
1391 | goto abort_transaction; | |
1392 | } | |
3e334239 MA |
1393 | err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", |
1394 | XEN_IO_PROTO_ABI_NATIVE); | |
1395 | if (err) { | |
1396 | message = "writing protocol"; | |
1397 | goto abort_transaction; | |
1398 | } | |
0a8704a5 | 1399 | err = xenbus_printf(xbt, dev->nodename, |
cb5bd4d1 | 1400 | "feature-persistent", "%u", 1); |
0a8704a5 RPM |
1401 | if (err) |
1402 | dev_warn(&dev->dev, | |
1403 | "writing persistent grants feature to xenbus"); | |
9f27ee59 JF |
1404 | |
1405 | err = xenbus_transaction_end(xbt, 0); | |
1406 | if (err) { | |
1407 | if (err == -EAGAIN) | |
1408 | goto again; | |
1409 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
1410 | goto destroy_blkring; | |
1411 | } | |
1412 | ||
86839c56 BL |
1413 | for (i = 0; i < BLK_RING_SIZE(info); i++) |
1414 | info->shadow[i].req.u.rw.id = i+1; | |
1415 | info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; | |
9f27ee59 JF |
1416 | xenbus_switch_state(dev, XenbusStateInitialised); |
1417 | ||
1418 | return 0; | |
1419 | ||
1420 | abort_transaction: | |
1421 | xenbus_transaction_end(xbt, 1); | |
1422 | if (message) | |
1423 | xenbus_dev_fatal(dev, err, "%s", message); | |
1424 | destroy_blkring: | |
1425 | blkif_free(info, 0); | |
1426 | out: | |
1427 | return err; | |
1428 | } | |
1429 | ||
9f27ee59 JF |
1430 | /** |
1431 | * Entry point to this code when a new device is created. Allocate the basic | |
1432 | * structures and the ring buffer for communication with the backend, and | |
1433 | * inform the backend of the appropriate details for those. Switch to | |
1434 | * Initialised state. | |
1435 | */ | |
1436 | static int blkfront_probe(struct xenbus_device *dev, | |
1437 | const struct xenbus_device_id *id) | |
1438 | { | |
86839c56 | 1439 | int err, vdevice; |
9f27ee59 JF |
1440 | struct blkfront_info *info; |
1441 | ||
1442 | /* FIXME: Use dynamic device id if this is not set. */ | |
1443 | err = xenbus_scanf(XBT_NIL, dev->nodename, | |
1444 | "virtual-device", "%i", &vdevice); | |
1445 | if (err != 1) { | |
9246b5f0 CL |
1446 | /* go looking in the extended area instead */ |
1447 | err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext", | |
1448 | "%i", &vdevice); | |
1449 | if (err != 1) { | |
1450 | xenbus_dev_fatal(dev, err, "reading virtual-device"); | |
1451 | return err; | |
1452 | } | |
9f27ee59 JF |
1453 | } |
1454 | ||
b98a409b SS |
1455 | if (xen_hvm_domain()) { |
1456 | char *type; | |
1457 | int len; | |
1458 | /* no unplug has been done: do not hook devices != xen vbds */ | |
51c71a3b | 1459 | if (xen_has_pv_and_legacy_disk_devices()) { |
b98a409b SS |
1460 | int major; |
1461 | ||
1462 | if (!VDEV_IS_EXTENDED(vdevice)) | |
1463 | major = BLKIF_MAJOR(vdevice); | |
1464 | else | |
1465 | major = XENVBD_MAJOR; | |
1466 | ||
1467 | if (major != XENVBD_MAJOR) { | |
1468 | printk(KERN_INFO | |
1469 | "%s: HVM does not support vbd %d as xen block device\n", | |
02f1f217 | 1470 | __func__, vdevice); |
b98a409b SS |
1471 | return -ENODEV; |
1472 | } | |
1473 | } | |
1474 | /* do not create a PV cdrom device if we are an HVM guest */ | |
1475 | type = xenbus_read(XBT_NIL, dev->nodename, "device-type", &len); | |
1476 | if (IS_ERR(type)) | |
1477 | return -ENODEV; | |
1478 | if (strncmp(type, "cdrom", 5) == 0) { | |
1479 | kfree(type); | |
c1c5413a SS |
1480 | return -ENODEV; |
1481 | } | |
b98a409b | 1482 | kfree(type); |
c1c5413a | 1483 | } |
9f27ee59 JF |
1484 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
1485 | if (!info) { | |
1486 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
1487 | return -ENOMEM; | |
1488 | } | |
1489 | ||
b70f5fa0 | 1490 | mutex_init(&info->mutex); |
3467811e | 1491 | spin_lock_init(&info->io_lock); |
9f27ee59 JF |
1492 | info->xbdev = dev; |
1493 | info->vdevice = vdevice; | |
bfe11d6d RPM |
1494 | INIT_LIST_HEAD(&info->grants); |
1495 | INIT_LIST_HEAD(&info->indirect_pages); | |
0a8704a5 | 1496 | info->persistent_gnts_c = 0; |
9f27ee59 JF |
1497 | info->connected = BLKIF_STATE_DISCONNECTED; |
1498 | INIT_WORK(&info->work, blkif_restart_queue); | |
1499 | ||
9f27ee59 JF |
1500 | /* Front end dir is a number, which is used as the id. */ |
1501 | info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); | |
a1b4b12b | 1502 | dev_set_drvdata(&dev->dev, info); |
9f27ee59 | 1503 | |
9f27ee59 JF |
1504 | return 0; |
1505 | } | |
1506 | ||
4246a0b6 | 1507 | static void split_bio_end(struct bio *bio) |
402b27f9 RPM |
1508 | { |
1509 | struct split_bio *split_bio = bio->bi_private; | |
1510 | ||
402b27f9 RPM |
1511 | if (atomic_dec_and_test(&split_bio->pending)) { |
1512 | split_bio->bio->bi_phys_segments = 0; | |
4246a0b6 CH |
1513 | split_bio->bio->bi_error = bio->bi_error; |
1514 | bio_endio(split_bio->bio); | |
402b27f9 RPM |
1515 | kfree(split_bio); |
1516 | } | |
1517 | bio_put(bio); | |
1518 | } | |
9f27ee59 JF |
1519 | |
1520 | static int blkif_recover(struct blkfront_info *info) | |
1521 | { | |
1522 | int i; | |
402b27f9 | 1523 | struct request *req, *n; |
9f27ee59 | 1524 | struct blk_shadow *copy; |
402b27f9 RPM |
1525 | int rc; |
1526 | struct bio *bio, *cloned_bio; | |
1527 | struct bio_list bio_list, merge_bio; | |
1528 | unsigned int segs, offset; | |
1529 | int pending, size; | |
1530 | struct split_bio *split_bio; | |
1531 | struct list_head requests; | |
9f27ee59 JF |
1532 | |
1533 | /* Stage 1: Make a safe copy of the shadow state. */ | |
29d0b218 | 1534 | copy = kmemdup(info->shadow, sizeof(info->shadow), |
a144ff09 | 1535 | GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); |
9f27ee59 JF |
1536 | if (!copy) |
1537 | return -ENOMEM; | |
9f27ee59 JF |
1538 | |
1539 | /* Stage 2: Set up free list. */ | |
1540 | memset(&info->shadow, 0, sizeof(info->shadow)); | |
86839c56 | 1541 | for (i = 0; i < BLK_RING_SIZE(info); i++) |
97e36834 | 1542 | info->shadow[i].req.u.rw.id = i+1; |
9f27ee59 | 1543 | info->shadow_free = info->ring.req_prod_pvt; |
86839c56 | 1544 | info->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; |
9f27ee59 | 1545 | |
d50babbe | 1546 | rc = blkfront_gather_backend_features(info); |
402b27f9 RPM |
1547 | if (rc) { |
1548 | kfree(copy); | |
1549 | return rc; | |
1550 | } | |
1551 | ||
1552 | segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
1553 | blk_queue_max_segments(info->rq, segs); | |
1554 | bio_list_init(&bio_list); | |
1555 | INIT_LIST_HEAD(&requests); | |
86839c56 | 1556 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
9f27ee59 | 1557 | /* Not in use? */ |
a945b980 | 1558 | if (!copy[i].request) |
9f27ee59 JF |
1559 | continue; |
1560 | ||
402b27f9 RPM |
1561 | /* |
1562 | * Get the bios in the request so we can re-queue them. | |
1563 | */ | |
1564 | if (copy[i].request->cmd_flags & | |
1565 | (REQ_FLUSH | REQ_FUA | REQ_DISCARD | REQ_SECURE)) { | |
1566 | /* | |
1567 | * Flush operations don't contain bios, so | |
1568 | * we need to requeue the whole request | |
1569 | */ | |
1570 | list_add(©[i].request->queuelist, &requests); | |
1571 | continue; | |
5ea42986 | 1572 | } |
402b27f9 RPM |
1573 | merge_bio.head = copy[i].request->bio; |
1574 | merge_bio.tail = copy[i].request->biotail; | |
1575 | bio_list_merge(&bio_list, &merge_bio); | |
1576 | copy[i].request->bio = NULL; | |
3bb8c98e | 1577 | blk_end_request_all(copy[i].request, 0); |
9f27ee59 JF |
1578 | } |
1579 | ||
1580 | kfree(copy); | |
1581 | ||
1582 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1583 | ||
3467811e | 1584 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1585 | |
1586 | /* Now safe for us to use the shared ring */ | |
1587 | info->connected = BLKIF_STATE_CONNECTED; | |
1588 | ||
9f27ee59 JF |
1589 | /* Kick any other new requests queued since we resumed */ |
1590 | kick_pending_request_queues(info); | |
1591 | ||
402b27f9 RPM |
1592 | list_for_each_entry_safe(req, n, &requests, queuelist) { |
1593 | /* Requeue pending requests (flush or discard) */ | |
1594 | list_del_init(&req->queuelist); | |
1595 | BUG_ON(req->nr_phys_segments > segs); | |
907c3eb1 | 1596 | blk_mq_requeue_request(req); |
402b27f9 | 1597 | } |
3467811e | 1598 | spin_unlock_irq(&info->io_lock); |
907c3eb1 | 1599 | blk_mq_kick_requeue_list(info->rq); |
9f27ee59 | 1600 | |
402b27f9 RPM |
1601 | while ((bio = bio_list_pop(&bio_list)) != NULL) { |
1602 | /* Traverse the list of pending bios and re-queue them */ | |
1603 | if (bio_segments(bio) > segs) { | |
1604 | /* | |
1605 | * This bio has more segments than what we can | |
1606 | * handle, we have to split it. | |
1607 | */ | |
1608 | pending = (bio_segments(bio) + segs - 1) / segs; | |
1609 | split_bio = kzalloc(sizeof(*split_bio), GFP_NOIO); | |
1610 | BUG_ON(split_bio == NULL); | |
1611 | atomic_set(&split_bio->pending, pending); | |
1612 | split_bio->bio = bio; | |
1613 | for (i = 0; i < pending; i++) { | |
1614 | offset = (i * segs * PAGE_SIZE) >> 9; | |
1615 | size = min((unsigned int)(segs * PAGE_SIZE) >> 9, | |
4f024f37 | 1616 | (unsigned int)bio_sectors(bio) - offset); |
402b27f9 RPM |
1617 | cloned_bio = bio_clone(bio, GFP_NOIO); |
1618 | BUG_ON(cloned_bio == NULL); | |
6678d83f | 1619 | bio_trim(cloned_bio, offset, size); |
402b27f9 RPM |
1620 | cloned_bio->bi_private = split_bio; |
1621 | cloned_bio->bi_end_io = split_bio_end; | |
1622 | submit_bio(cloned_bio->bi_rw, cloned_bio); | |
1623 | } | |
1624 | /* | |
1625 | * Now we have to wait for all those smaller bios to | |
1626 | * end, so we can also end the "parent" bio. | |
1627 | */ | |
1628 | continue; | |
1629 | } | |
1630 | /* We don't need to split this bio */ | |
1631 | submit_bio(bio->bi_rw, bio); | |
1632 | } | |
1633 | ||
9f27ee59 JF |
1634 | return 0; |
1635 | } | |
1636 | ||
1637 | /** | |
1638 | * We are reconnecting to the backend, due to a suspend/resume, or a backend | |
1639 | * driver restart. We tear down our blkif structure and recreate it, but | |
1640 | * leave the device-layer structures intact so that this is transparent to the | |
1641 | * rest of the kernel. | |
1642 | */ | |
1643 | static int blkfront_resume(struct xenbus_device *dev) | |
1644 | { | |
a1b4b12b | 1645 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 JF |
1646 | int err; |
1647 | ||
1648 | dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename); | |
1649 | ||
1650 | blkif_free(info, info->connected == BLKIF_STATE_CONNECTED); | |
1651 | ||
203fd61f | 1652 | err = talk_to_blkback(dev, info); |
402b27f9 RPM |
1653 | |
1654 | /* | |
1655 | * We have to wait for the backend to switch to | |
1656 | * connected state, since we want to read which | |
1657 | * features it supports. | |
1658 | */ | |
9f27ee59 JF |
1659 | |
1660 | return err; | |
1661 | } | |
1662 | ||
b70f5fa0 DS |
1663 | static void |
1664 | blkfront_closing(struct blkfront_info *info) | |
1665 | { | |
1666 | struct xenbus_device *xbdev = info->xbdev; | |
1667 | struct block_device *bdev = NULL; | |
1668 | ||
1669 | mutex_lock(&info->mutex); | |
1670 | ||
1671 | if (xbdev->state == XenbusStateClosing) { | |
1672 | mutex_unlock(&info->mutex); | |
1673 | return; | |
1674 | } | |
1675 | ||
1676 | if (info->gd) | |
1677 | bdev = bdget_disk(info->gd, 0); | |
1678 | ||
1679 | mutex_unlock(&info->mutex); | |
1680 | ||
1681 | if (!bdev) { | |
1682 | xenbus_frontend_closed(xbdev); | |
1683 | return; | |
1684 | } | |
1685 | ||
1686 | mutex_lock(&bdev->bd_mutex); | |
1687 | ||
7b32d104 | 1688 | if (bdev->bd_openers) { |
b70f5fa0 DS |
1689 | xenbus_dev_error(xbdev, -EBUSY, |
1690 | "Device in use; refusing to close"); | |
1691 | xenbus_switch_state(xbdev, XenbusStateClosing); | |
1692 | } else { | |
1693 | xlvbd_release_gendisk(info); | |
1694 | xenbus_frontend_closed(xbdev); | |
1695 | } | |
1696 | ||
1697 | mutex_unlock(&bdev->bd_mutex); | |
1698 | bdput(bdev); | |
1699 | } | |
9f27ee59 | 1700 | |
ed30bf31 LD |
1701 | static void blkfront_setup_discard(struct blkfront_info *info) |
1702 | { | |
1703 | int err; | |
ed30bf31 LD |
1704 | unsigned int discard_granularity; |
1705 | unsigned int discard_alignment; | |
5ea42986 | 1706 | unsigned int discard_secure; |
ed30bf31 | 1707 | |
1c8cad6c OH |
1708 | info->feature_discard = 1; |
1709 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1710 | "discard-granularity", "%u", &discard_granularity, | |
1711 | "discard-alignment", "%u", &discard_alignment, | |
1712 | NULL); | |
1713 | if (!err) { | |
1714 | info->discard_granularity = discard_granularity; | |
1715 | info->discard_alignment = discard_alignment; | |
1716 | } | |
1717 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1718 | "discard-secure", "%d", &discard_secure, | |
1719 | NULL); | |
1720 | if (!err) | |
1721 | info->feature_secdiscard = !!discard_secure; | |
ed30bf31 LD |
1722 | } |
1723 | ||
402b27f9 RPM |
1724 | static int blkfront_setup_indirect(struct blkfront_info *info) |
1725 | { | |
d50babbe | 1726 | unsigned int segs; |
402b27f9 RPM |
1727 | int err, i; |
1728 | ||
d50babbe | 1729 | if (info->max_indirect_segments == 0) |
402b27f9 | 1730 | segs = BLKIF_MAX_SEGMENTS_PER_REQUEST; |
d50babbe | 1731 | else |
402b27f9 | 1732 | segs = info->max_indirect_segments; |
402b27f9 | 1733 | |
86839c56 | 1734 | err = fill_grant_buffer(info, (segs + INDIRECT_GREFS(segs)) * BLK_RING_SIZE(info)); |
402b27f9 RPM |
1735 | if (err) |
1736 | goto out_of_memory; | |
1737 | ||
bfe11d6d RPM |
1738 | if (!info->feature_persistent && info->max_indirect_segments) { |
1739 | /* | |
1740 | * We are using indirect descriptors but not persistent | |
1741 | * grants, we need to allocate a set of pages that can be | |
1742 | * used for mapping indirect grefs | |
1743 | */ | |
86839c56 | 1744 | int num = INDIRECT_GREFS(segs) * BLK_RING_SIZE(info); |
bfe11d6d RPM |
1745 | |
1746 | BUG_ON(!list_empty(&info->indirect_pages)); | |
1747 | for (i = 0; i < num; i++) { | |
1748 | struct page *indirect_page = alloc_page(GFP_NOIO); | |
1749 | if (!indirect_page) | |
1750 | goto out_of_memory; | |
1751 | list_add(&indirect_page->lru, &info->indirect_pages); | |
1752 | } | |
1753 | } | |
1754 | ||
86839c56 | 1755 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1756 | info->shadow[i].grants_used = kzalloc( |
1757 | sizeof(info->shadow[i].grants_used[0]) * segs, | |
1758 | GFP_NOIO); | |
b7649158 | 1759 | info->shadow[i].sg = kzalloc(sizeof(info->shadow[i].sg[0]) * segs, GFP_NOIO); |
402b27f9 RPM |
1760 | if (info->max_indirect_segments) |
1761 | info->shadow[i].indirect_grants = kzalloc( | |
1762 | sizeof(info->shadow[i].indirect_grants[0]) * | |
1763 | INDIRECT_GREFS(segs), | |
1764 | GFP_NOIO); | |
1765 | if ((info->shadow[i].grants_used == NULL) || | |
b7649158 | 1766 | (info->shadow[i].sg == NULL) || |
402b27f9 RPM |
1767 | (info->max_indirect_segments && |
1768 | (info->shadow[i].indirect_grants == NULL))) | |
1769 | goto out_of_memory; | |
b7649158 | 1770 | sg_init_table(info->shadow[i].sg, segs); |
402b27f9 RPM |
1771 | } |
1772 | ||
1773 | ||
1774 | return 0; | |
1775 | ||
1776 | out_of_memory: | |
86839c56 | 1777 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1778 | kfree(info->shadow[i].grants_used); |
1779 | info->shadow[i].grants_used = NULL; | |
b7649158 RPM |
1780 | kfree(info->shadow[i].sg); |
1781 | info->shadow[i].sg = NULL; | |
402b27f9 RPM |
1782 | kfree(info->shadow[i].indirect_grants); |
1783 | info->shadow[i].indirect_grants = NULL; | |
1784 | } | |
bfe11d6d RPM |
1785 | if (!list_empty(&info->indirect_pages)) { |
1786 | struct page *indirect_page, *n; | |
1787 | list_for_each_entry_safe(indirect_page, n, &info->indirect_pages, lru) { | |
1788 | list_del(&indirect_page->lru); | |
1789 | __free_page(indirect_page); | |
1790 | } | |
1791 | } | |
402b27f9 RPM |
1792 | return -ENOMEM; |
1793 | } | |
1794 | ||
d50babbe BL |
1795 | /* |
1796 | * Gather all backend feature-* | |
1797 | */ | |
1798 | static int blkfront_gather_backend_features(struct blkfront_info *info) | |
1799 | { | |
1800 | int err; | |
1801 | int barrier, flush, discard, persistent; | |
1802 | unsigned int indirect_segments; | |
1803 | ||
1804 | info->feature_flush = 0; | |
1805 | ||
1806 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1807 | "feature-barrier", "%d", &barrier, | |
1808 | NULL); | |
1809 | ||
1810 | /* | |
1811 | * If there's no "feature-barrier" defined, then it means | |
1812 | * we're dealing with a very old backend which writes | |
1813 | * synchronously; nothing to do. | |
1814 | * | |
1815 | * If there are barriers, then we use flush. | |
1816 | */ | |
1817 | if (!err && barrier) | |
1818 | info->feature_flush = REQ_FLUSH | REQ_FUA; | |
1819 | /* | |
1820 | * And if there is "feature-flush-cache" use that above | |
1821 | * barriers. | |
1822 | */ | |
1823 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1824 | "feature-flush-cache", "%d", &flush, | |
1825 | NULL); | |
1826 | ||
1827 | if (!err && flush) | |
1828 | info->feature_flush = REQ_FLUSH; | |
1829 | ||
1830 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1831 | "feature-discard", "%d", &discard, | |
1832 | NULL); | |
1833 | ||
1834 | if (!err && discard) | |
1835 | blkfront_setup_discard(info); | |
1836 | ||
1837 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1838 | "feature-persistent", "%u", &persistent, | |
1839 | NULL); | |
1840 | if (err) | |
1841 | info->feature_persistent = 0; | |
1842 | else | |
1843 | info->feature_persistent = persistent; | |
1844 | ||
1845 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1846 | "feature-max-indirect-segments", "%u", &indirect_segments, | |
1847 | NULL); | |
1848 | if (err) | |
1849 | info->max_indirect_segments = 0; | |
1850 | else | |
1851 | info->max_indirect_segments = min(indirect_segments, | |
1852 | xen_blkif_max_segments); | |
1853 | ||
1854 | return blkfront_setup_indirect(info); | |
1855 | } | |
1856 | ||
9f27ee59 JF |
1857 | /* |
1858 | * Invoked when the backend is finally 'ready' (and has told produced | |
1859 | * the details about the physical device - #sectors, size, etc). | |
1860 | */ | |
1861 | static void blkfront_connect(struct blkfront_info *info) | |
1862 | { | |
1863 | unsigned long long sectors; | |
1864 | unsigned long sector_size; | |
7c4d7d71 | 1865 | unsigned int physical_sector_size; |
9f27ee59 JF |
1866 | unsigned int binfo; |
1867 | int err; | |
1868 | ||
1fa73be6 S |
1869 | switch (info->connected) { |
1870 | case BLKIF_STATE_CONNECTED: | |
1871 | /* | |
1872 | * Potentially, the back-end may be signalling | |
1873 | * a capacity change; update the capacity. | |
1874 | */ | |
1875 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1876 | "sectors", "%Lu", §ors); | |
1877 | if (XENBUS_EXIST_ERR(err)) | |
1878 | return; | |
1879 | printk(KERN_INFO "Setting capacity to %Lu\n", | |
1880 | sectors); | |
1881 | set_capacity(info->gd, sectors); | |
2def141e | 1882 | revalidate_disk(info->gd); |
1fa73be6 | 1883 | |
402b27f9 | 1884 | return; |
1fa73be6 | 1885 | case BLKIF_STATE_SUSPENDED: |
402b27f9 RPM |
1886 | /* |
1887 | * If we are recovering from suspension, we need to wait | |
1888 | * for the backend to announce it's features before | |
1889 | * reconnecting, at least we need to know if the backend | |
1890 | * supports indirect descriptors, and how many. | |
1891 | */ | |
1892 | blkif_recover(info); | |
9f27ee59 JF |
1893 | return; |
1894 | ||
b4dddb49 JF |
1895 | default: |
1896 | break; | |
1fa73be6 | 1897 | } |
9f27ee59 JF |
1898 | |
1899 | dev_dbg(&info->xbdev->dev, "%s:%s.\n", | |
1900 | __func__, info->xbdev->otherend); | |
1901 | ||
1902 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1903 | "sectors", "%llu", §ors, | |
1904 | "info", "%u", &binfo, | |
1905 | "sector-size", "%lu", §or_size, | |
1906 | NULL); | |
1907 | if (err) { | |
1908 | xenbus_dev_fatal(info->xbdev, err, | |
1909 | "reading backend fields at %s", | |
1910 | info->xbdev->otherend); | |
1911 | return; | |
1912 | } | |
1913 | ||
7c4d7d71 SB |
1914 | /* |
1915 | * physcial-sector-size is a newer field, so old backends may not | |
1916 | * provide this. Assume physical sector size to be the same as | |
1917 | * sector_size in that case. | |
1918 | */ | |
1919 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1920 | "physical-sector-size", "%u", &physical_sector_size); | |
1921 | if (err != 1) | |
1922 | physical_sector_size = sector_size; | |
1923 | ||
d50babbe | 1924 | err = blkfront_gather_backend_features(info); |
402b27f9 RPM |
1925 | if (err) { |
1926 | xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s", | |
1927 | info->xbdev->otherend); | |
1928 | return; | |
1929 | } | |
1930 | ||
7c4d7d71 SB |
1931 | err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size, |
1932 | physical_sector_size); | |
9f27ee59 JF |
1933 | if (err) { |
1934 | xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", | |
1935 | info->xbdev->otherend); | |
1936 | return; | |
1937 | } | |
1938 | ||
1939 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1940 | ||
1941 | /* Kick pending requests. */ | |
3467811e | 1942 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1943 | info->connected = BLKIF_STATE_CONNECTED; |
1944 | kick_pending_request_queues(info); | |
3467811e | 1945 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1946 | |
1947 | add_disk(info->gd); | |
1d78d705 CL |
1948 | |
1949 | info->is_ready = 1; | |
9f27ee59 JF |
1950 | } |
1951 | ||
9f27ee59 JF |
1952 | /** |
1953 | * Callback received when the backend's state changes. | |
1954 | */ | |
203fd61f | 1955 | static void blkback_changed(struct xenbus_device *dev, |
9f27ee59 JF |
1956 | enum xenbus_state backend_state) |
1957 | { | |
a1b4b12b | 1958 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 | 1959 | |
203fd61f | 1960 | dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); |
9f27ee59 JF |
1961 | |
1962 | switch (backend_state) { | |
9f27ee59 | 1963 | case XenbusStateInitWait: |
a9b54bb9 BL |
1964 | if (dev->state != XenbusStateInitialising) |
1965 | break; | |
8ab0144a BL |
1966 | if (talk_to_blkback(dev, info)) { |
1967 | kfree(info); | |
1968 | dev_set_drvdata(&dev->dev, NULL); | |
1969 | break; | |
1970 | } | |
1971 | case XenbusStateInitialising: | |
9f27ee59 | 1972 | case XenbusStateInitialised: |
b78c9512 NI |
1973 | case XenbusStateReconfiguring: |
1974 | case XenbusStateReconfigured: | |
9f27ee59 | 1975 | case XenbusStateUnknown: |
9f27ee59 JF |
1976 | break; |
1977 | ||
1978 | case XenbusStateConnected: | |
1979 | blkfront_connect(info); | |
1980 | break; | |
1981 | ||
36613717 DV |
1982 | case XenbusStateClosed: |
1983 | if (dev->state == XenbusStateClosed) | |
1984 | break; | |
1985 | /* Missed the backend's Closing state -- fallthrough */ | |
9f27ee59 | 1986 | case XenbusStateClosing: |
b70f5fa0 | 1987 | blkfront_closing(info); |
9f27ee59 JF |
1988 | break; |
1989 | } | |
1990 | } | |
1991 | ||
fa1bd359 | 1992 | static int blkfront_remove(struct xenbus_device *xbdev) |
9f27ee59 | 1993 | { |
fa1bd359 DS |
1994 | struct blkfront_info *info = dev_get_drvdata(&xbdev->dev); |
1995 | struct block_device *bdev = NULL; | |
1996 | struct gendisk *disk; | |
9f27ee59 | 1997 | |
fa1bd359 | 1998 | dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename); |
9f27ee59 JF |
1999 | |
2000 | blkif_free(info, 0); | |
2001 | ||
fa1bd359 DS |
2002 | mutex_lock(&info->mutex); |
2003 | ||
2004 | disk = info->gd; | |
2005 | if (disk) | |
2006 | bdev = bdget_disk(disk, 0); | |
2007 | ||
2008 | info->xbdev = NULL; | |
2009 | mutex_unlock(&info->mutex); | |
2010 | ||
2011 | if (!bdev) { | |
2012 | kfree(info); | |
2013 | return 0; | |
2014 | } | |
2015 | ||
2016 | /* | |
2017 | * The xbdev was removed before we reached the Closed | |
2018 | * state. See if it's safe to remove the disk. If the bdev | |
2019 | * isn't closed yet, we let release take care of it. | |
2020 | */ | |
2021 | ||
2022 | mutex_lock(&bdev->bd_mutex); | |
2023 | info = disk->private_data; | |
2024 | ||
d54142c7 DS |
2025 | dev_warn(disk_to_dev(disk), |
2026 | "%s was hot-unplugged, %d stale handles\n", | |
2027 | xbdev->nodename, bdev->bd_openers); | |
2028 | ||
7b32d104 | 2029 | if (info && !bdev->bd_openers) { |
fa1bd359 DS |
2030 | xlvbd_release_gendisk(info); |
2031 | disk->private_data = NULL; | |
0e345826 | 2032 | kfree(info); |
fa1bd359 DS |
2033 | } |
2034 | ||
2035 | mutex_unlock(&bdev->bd_mutex); | |
2036 | bdput(bdev); | |
9f27ee59 JF |
2037 | |
2038 | return 0; | |
2039 | } | |
2040 | ||
1d78d705 CL |
2041 | static int blkfront_is_ready(struct xenbus_device *dev) |
2042 | { | |
a1b4b12b | 2043 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
1d78d705 | 2044 | |
5d7ed20e | 2045 | return info->is_ready && info->xbdev; |
1d78d705 CL |
2046 | } |
2047 | ||
a63c848b | 2048 | static int blkif_open(struct block_device *bdev, fmode_t mode) |
9f27ee59 | 2049 | { |
13961743 DS |
2050 | struct gendisk *disk = bdev->bd_disk; |
2051 | struct blkfront_info *info; | |
2052 | int err = 0; | |
6e9624b8 | 2053 | |
2a48fc0a | 2054 | mutex_lock(&blkfront_mutex); |
6e9624b8 | 2055 | |
13961743 DS |
2056 | info = disk->private_data; |
2057 | if (!info) { | |
2058 | /* xbdev gone */ | |
2059 | err = -ERESTARTSYS; | |
2060 | goto out; | |
2061 | } | |
2062 | ||
2063 | mutex_lock(&info->mutex); | |
2064 | ||
2065 | if (!info->gd) | |
2066 | /* xbdev is closed */ | |
2067 | err = -ERESTARTSYS; | |
2068 | ||
2069 | mutex_unlock(&info->mutex); | |
2070 | ||
13961743 | 2071 | out: |
2a48fc0a | 2072 | mutex_unlock(&blkfront_mutex); |
13961743 | 2073 | return err; |
9f27ee59 JF |
2074 | } |
2075 | ||
db2a144b | 2076 | static void blkif_release(struct gendisk *disk, fmode_t mode) |
9f27ee59 | 2077 | { |
a63c848b | 2078 | struct blkfront_info *info = disk->private_data; |
7fd152f4 DS |
2079 | struct block_device *bdev; |
2080 | struct xenbus_device *xbdev; | |
2081 | ||
2a48fc0a | 2082 | mutex_lock(&blkfront_mutex); |
7fd152f4 DS |
2083 | |
2084 | bdev = bdget_disk(disk, 0); | |
7fd152f4 | 2085 | |
2f089cb8 FP |
2086 | if (!bdev) { |
2087 | WARN(1, "Block device %s yanked out from us!\n", disk->disk_name); | |
2088 | goto out_mutex; | |
2089 | } | |
acfca3c6 DS |
2090 | if (bdev->bd_openers) |
2091 | goto out; | |
2092 | ||
7fd152f4 DS |
2093 | /* |
2094 | * Check if we have been instructed to close. We will have | |
2095 | * deferred this request, because the bdev was still open. | |
2096 | */ | |
2097 | ||
2098 | mutex_lock(&info->mutex); | |
2099 | xbdev = info->xbdev; | |
2100 | ||
2101 | if (xbdev && xbdev->state == XenbusStateClosing) { | |
2102 | /* pending switch to state closed */ | |
d54142c7 | 2103 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2104 | xlvbd_release_gendisk(info); |
2105 | xenbus_frontend_closed(info->xbdev); | |
2106 | } | |
2107 | ||
2108 | mutex_unlock(&info->mutex); | |
2109 | ||
2110 | if (!xbdev) { | |
2111 | /* sudden device removal */ | |
d54142c7 | 2112 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2113 | xlvbd_release_gendisk(info); |
2114 | disk->private_data = NULL; | |
2115 | kfree(info); | |
9f27ee59 | 2116 | } |
7fd152f4 | 2117 | |
a4cc14ec | 2118 | out: |
dad5cf65 | 2119 | bdput(bdev); |
2f089cb8 | 2120 | out_mutex: |
2a48fc0a | 2121 | mutex_unlock(&blkfront_mutex); |
9f27ee59 JF |
2122 | } |
2123 | ||
83d5cde4 | 2124 | static const struct block_device_operations xlvbd_block_fops = |
9f27ee59 JF |
2125 | { |
2126 | .owner = THIS_MODULE, | |
a63c848b AV |
2127 | .open = blkif_open, |
2128 | .release = blkif_release, | |
597592d9 | 2129 | .getgeo = blkif_getgeo, |
8a6cfeb6 | 2130 | .ioctl = blkif_ioctl, |
9f27ee59 JF |
2131 | }; |
2132 | ||
2133 | ||
ec9c42ec | 2134 | static const struct xenbus_device_id blkfront_ids[] = { |
9f27ee59 JF |
2135 | { "vbd" }, |
2136 | { "" } | |
2137 | }; | |
2138 | ||
95afae48 DV |
2139 | static struct xenbus_driver blkfront_driver = { |
2140 | .ids = blkfront_ids, | |
9f27ee59 JF |
2141 | .probe = blkfront_probe, |
2142 | .remove = blkfront_remove, | |
2143 | .resume = blkfront_resume, | |
203fd61f | 2144 | .otherend_changed = blkback_changed, |
1d78d705 | 2145 | .is_ready = blkfront_is_ready, |
95afae48 | 2146 | }; |
9f27ee59 JF |
2147 | |
2148 | static int __init xlblk_init(void) | |
2149 | { | |
469738e6 LE |
2150 | int ret; |
2151 | ||
6e833587 | 2152 | if (!xen_domain()) |
9f27ee59 JF |
2153 | return -ENODEV; |
2154 | ||
86839c56 BL |
2155 | if (xen_blkif_max_ring_order > XENBUS_MAX_RING_PAGE_ORDER) { |
2156 | pr_info("Invalid max_ring_order (%d), will use default max: %d.\n", | |
2157 | xen_blkif_max_ring_order, XENBUS_MAX_RING_PAGE_ORDER); | |
2158 | xen_blkif_max_ring_order = 0; | |
2159 | } | |
2160 | ||
51c71a3b | 2161 | if (!xen_has_pv_disk_devices()) |
b9136d20 IM |
2162 | return -ENODEV; |
2163 | ||
9f27ee59 JF |
2164 | if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { |
2165 | printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", | |
2166 | XENVBD_MAJOR, DEV_NAME); | |
2167 | return -ENODEV; | |
2168 | } | |
2169 | ||
73db144b | 2170 | ret = xenbus_register_frontend(&blkfront_driver); |
469738e6 LE |
2171 | if (ret) { |
2172 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2173 | return ret; | |
2174 | } | |
2175 | ||
2176 | return 0; | |
9f27ee59 JF |
2177 | } |
2178 | module_init(xlblk_init); | |
2179 | ||
2180 | ||
5a60d0cd | 2181 | static void __exit xlblk_exit(void) |
9f27ee59 | 2182 | { |
8605067f JB |
2183 | xenbus_unregister_driver(&blkfront_driver); |
2184 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2185 | kfree(minors); | |
9f27ee59 JF |
2186 | } |
2187 | module_exit(xlblk_exit); | |
2188 | ||
2189 | MODULE_DESCRIPTION("Xen virtual block device frontend"); | |
2190 | MODULE_LICENSE("GPL"); | |
2191 | MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR); | |
d2f0c52b | 2192 | MODULE_ALIAS("xen:vbd"); |
4f93f09b | 2193 | MODULE_ALIAS("xenblk"); |