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 | ||
6cc56833 JG |
63 | /* |
64 | * The minimal size of segment supported by the block framework is PAGE_SIZE. | |
65 | * When Linux is using a different page size than Xen, it may not be possible | |
66 | * to put all the data in a single segment. | |
67 | * This can happen when the backend doesn't support indirect descriptor and | |
68 | * therefore the maximum amount of data that a request can carry is | |
69 | * BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE = 44KB | |
70 | * | |
71 | * Note that we only support one extra request. So the Linux page size | |
72 | * should be <= ( 2 * BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE) = | |
73 | * 88KB. | |
74 | */ | |
75 | #define HAS_EXTRA_REQ (BLKIF_MAX_SEGMENTS_PER_REQUEST < XEN_PFN_PER_PAGE) | |
76 | ||
9f27ee59 JF |
77 | enum blkif_state { |
78 | BLKIF_STATE_DISCONNECTED, | |
79 | BLKIF_STATE_CONNECTED, | |
80 | BLKIF_STATE_SUSPENDED, | |
81 | }; | |
82 | ||
0a8704a5 RPM |
83 | struct grant { |
84 | grant_ref_t gref; | |
a7a6df22 | 85 | struct page *page; |
155b7edb | 86 | struct list_head node; |
0a8704a5 RPM |
87 | }; |
88 | ||
6cc56833 JG |
89 | enum blk_req_status { |
90 | REQ_WAITING, | |
91 | REQ_DONE, | |
92 | REQ_ERROR, | |
93 | REQ_EOPNOTSUPP, | |
94 | }; | |
95 | ||
9f27ee59 JF |
96 | struct blk_shadow { |
97 | struct blkif_request req; | |
a945b980 | 98 | struct request *request; |
402b27f9 RPM |
99 | struct grant **grants_used; |
100 | struct grant **indirect_grants; | |
b7649158 | 101 | struct scatterlist *sg; |
c004a6fe | 102 | unsigned int num_sg; |
6cc56833 JG |
103 | enum blk_req_status status; |
104 | ||
105 | #define NO_ASSOCIATED_ID ~0UL | |
106 | /* | |
107 | * Id of the sibling if we ever need 2 requests when handling a | |
108 | * block I/O request | |
109 | */ | |
110 | unsigned long associated_id; | |
402b27f9 RPM |
111 | }; |
112 | ||
113 | struct split_bio { | |
114 | struct bio *bio; | |
115 | atomic_t pending; | |
9f27ee59 JF |
116 | }; |
117 | ||
2a48fc0a | 118 | static DEFINE_MUTEX(blkfront_mutex); |
83d5cde4 | 119 | static const struct block_device_operations xlvbd_block_fops; |
9f27ee59 | 120 | |
402b27f9 RPM |
121 | /* |
122 | * Maximum number of segments in indirect requests, the actual value used by | |
123 | * the frontend driver is the minimum of this value and the value provided | |
124 | * by the backend driver. | |
125 | */ | |
126 | ||
127 | static unsigned int xen_blkif_max_segments = 32; | |
14e710fe JB |
128 | module_param_named(max_indirect_segments, xen_blkif_max_segments, uint, |
129 | S_IRUGO); | |
130 | MODULE_PARM_DESC(max_indirect_segments, | |
131 | "Maximum amount of segments in indirect requests (default is 32)"); | |
402b27f9 | 132 | |
28d949bc BL |
133 | static unsigned int xen_blkif_max_queues = 4; |
134 | module_param_named(max_queues, xen_blkif_max_queues, uint, S_IRUGO); | |
135 | MODULE_PARM_DESC(max_queues, "Maximum number of hardware queues/rings used per virtual disk"); | |
136 | ||
86839c56 BL |
137 | /* |
138 | * Maximum order of pages to be used for the shared ring between front and | |
139 | * backend, 4KB page granularity is used. | |
140 | */ | |
141 | static unsigned int xen_blkif_max_ring_order; | |
142 | module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, S_IRUGO); | |
143 | MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring"); | |
144 | ||
c004a6fe JG |
145 | #define BLK_RING_SIZE(info) \ |
146 | __CONST_RING_SIZE(blkif, XEN_PAGE_SIZE * (info)->nr_ring_pages) | |
147 | ||
148 | #define BLK_MAX_RING_SIZE \ | |
9cce2914 | 149 | __CONST_RING_SIZE(blkif, XEN_PAGE_SIZE * XENBUS_MAX_RING_GRANTS) |
c004a6fe | 150 | |
86839c56 | 151 | /* |
6f03a7ff KRW |
152 | * ring-ref%u i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19 |
153 | * characters are enough. Define to 20 to keep consistent with backend. | |
86839c56 BL |
154 | */ |
155 | #define RINGREF_NAME_LEN (20) | |
28d949bc BL |
156 | /* |
157 | * queue-%u would take 7 + 10(UINT_MAX) = 17 characters. | |
158 | */ | |
159 | #define QUEUE_NAME_LEN (17) | |
9f27ee59 | 160 | |
81f35161 BL |
161 | /* |
162 | * Per-ring info. | |
163 | * Every blkfront device can associate with one or more blkfront_ring_info, | |
164 | * depending on how many hardware queues/rings to be used. | |
165 | */ | |
166 | struct blkfront_ring_info { | |
11659569 BL |
167 | /* Lock to protect data in every ring buffer. */ |
168 | spinlock_t ring_lock; | |
81f35161 BL |
169 | struct blkif_front_ring ring; |
170 | unsigned int ring_ref[XENBUS_MAX_RING_GRANTS]; | |
171 | unsigned int evtchn, irq; | |
172 | struct work_struct work; | |
173 | struct gnttab_free_callback callback; | |
174 | struct blk_shadow shadow[BLK_MAX_RING_SIZE]; | |
175 | struct list_head indirect_pages; | |
73716df7 BL |
176 | struct list_head grants; |
177 | unsigned int persistent_gnts_c; | |
81f35161 BL |
178 | unsigned long shadow_free; |
179 | struct blkfront_info *dev_info; | |
180 | }; | |
181 | ||
9f27ee59 JF |
182 | /* |
183 | * We have one of these per vbd, whether ide, scsi or 'other'. They | |
184 | * hang in private_data off the gendisk structure. We may end up | |
185 | * putting all kinds of interesting stuff here :-) | |
186 | */ | |
187 | struct blkfront_info | |
188 | { | |
b70f5fa0 | 189 | struct mutex mutex; |
9f27ee59 | 190 | struct xenbus_device *xbdev; |
9f27ee59 JF |
191 | struct gendisk *gd; |
192 | int vdevice; | |
193 | blkif_vdev_t handle; | |
194 | enum blkif_state connected; | |
3df0e505 | 195 | /* Number of pages per ring buffer. */ |
86839c56 | 196 | unsigned int nr_ring_pages; |
9f27ee59 | 197 | struct request_queue *rq; |
4913efe4 | 198 | unsigned int feature_flush; |
a418090a | 199 | unsigned int feature_fua; |
5ea42986 KRW |
200 | unsigned int feature_discard:1; |
201 | unsigned int feature_secdiscard:1; | |
ed30bf31 LD |
202 | unsigned int discard_granularity; |
203 | unsigned int discard_alignment; | |
0a8704a5 | 204 | unsigned int feature_persistent:1; |
c004a6fe | 205 | /* Number of 4KB segments handled */ |
402b27f9 | 206 | unsigned int max_indirect_segments; |
1d78d705 | 207 | int is_ready; |
907c3eb1 | 208 | struct blk_mq_tag_set tag_set; |
3df0e505 BL |
209 | struct blkfront_ring_info *rinfo; |
210 | unsigned int nr_rings; | |
7b427a59 BL |
211 | /* Save uncomplete reqs and bios for migration. */ |
212 | struct list_head requests; | |
213 | struct bio_list bio_list; | |
9f27ee59 JF |
214 | }; |
215 | ||
0e345826 JB |
216 | static unsigned int nr_minors; |
217 | static unsigned long *minors; | |
218 | static DEFINE_SPINLOCK(minor_lock); | |
219 | ||
9f27ee59 JF |
220 | #define GRANT_INVALID_REF 0 |
221 | ||
222 | #define PARTS_PER_DISK 16 | |
9246b5f0 | 223 | #define PARTS_PER_EXT_DISK 256 |
9f27ee59 JF |
224 | |
225 | #define BLKIF_MAJOR(dev) ((dev)>>8) | |
226 | #define BLKIF_MINOR(dev) ((dev) & 0xff) | |
227 | ||
9246b5f0 CL |
228 | #define EXT_SHIFT 28 |
229 | #define EXTENDED (1<<EXT_SHIFT) | |
230 | #define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED)) | |
231 | #define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED)) | |
c80a4209 SS |
232 | #define EMULATED_HD_DISK_MINOR_OFFSET (0) |
233 | #define EMULATED_HD_DISK_NAME_OFFSET (EMULATED_HD_DISK_MINOR_OFFSET / 256) | |
196cfe2a SB |
234 | #define EMULATED_SD_DISK_MINOR_OFFSET (0) |
235 | #define EMULATED_SD_DISK_NAME_OFFSET (EMULATED_SD_DISK_MINOR_OFFSET / 256) | |
9f27ee59 | 236 | |
9246b5f0 | 237 | #define DEV_NAME "xvd" /* name in /dev */ |
9f27ee59 | 238 | |
c004a6fe JG |
239 | /* |
240 | * Grants are always the same size as a Xen page (i.e 4KB). | |
241 | * A physical segment is always the same size as a Linux page. | |
242 | * Number of grants per physical segment | |
243 | */ | |
244 | #define GRANTS_PER_PSEG (PAGE_SIZE / XEN_PAGE_SIZE) | |
245 | ||
246 | #define GRANTS_PER_INDIRECT_FRAME \ | |
247 | (XEN_PAGE_SIZE / sizeof(struct blkif_request_segment)) | |
248 | ||
249 | #define PSEGS_PER_INDIRECT_FRAME \ | |
250 | (GRANTS_INDIRECT_FRAME / GRANTS_PSEGS) | |
251 | ||
252 | #define INDIRECT_GREFS(_grants) \ | |
253 | DIV_ROUND_UP(_grants, GRANTS_PER_INDIRECT_FRAME) | |
254 | ||
255 | #define GREFS(_psegs) ((_psegs) * GRANTS_PER_PSEG) | |
402b27f9 | 256 | |
81f35161 | 257 | static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo); |
3df0e505 | 258 | static void blkfront_gather_backend_features(struct blkfront_info *info); |
402b27f9 | 259 | |
81f35161 | 260 | static int get_id_from_freelist(struct blkfront_ring_info *rinfo) |
9f27ee59 | 261 | { |
81f35161 BL |
262 | unsigned long free = rinfo->shadow_free; |
263 | ||
264 | BUG_ON(free >= BLK_RING_SIZE(rinfo->dev_info)); | |
265 | rinfo->shadow_free = rinfo->shadow[free].req.u.rw.id; | |
266 | rinfo->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */ | |
9f27ee59 JF |
267 | return free; |
268 | } | |
269 | ||
81f35161 | 270 | static int add_id_to_freelist(struct blkfront_ring_info *rinfo, |
6f03a7ff | 271 | unsigned long id) |
9f27ee59 | 272 | { |
81f35161 | 273 | if (rinfo->shadow[id].req.u.rw.id != id) |
6878c32e | 274 | return -EINVAL; |
81f35161 | 275 | if (rinfo->shadow[id].request == NULL) |
6878c32e | 276 | return -EINVAL; |
81f35161 BL |
277 | rinfo->shadow[id].req.u.rw.id = rinfo->shadow_free; |
278 | rinfo->shadow[id].request = NULL; | |
279 | rinfo->shadow_free = id; | |
6878c32e | 280 | return 0; |
9f27ee59 JF |
281 | } |
282 | ||
81f35161 | 283 | static int fill_grant_buffer(struct blkfront_ring_info *rinfo, int num) |
9c1e050c | 284 | { |
81f35161 | 285 | struct blkfront_info *info = rinfo->dev_info; |
9c1e050c RPM |
286 | struct page *granted_page; |
287 | struct grant *gnt_list_entry, *n; | |
288 | int i = 0; | |
289 | ||
6f03a7ff | 290 | while (i < num) { |
9c1e050c RPM |
291 | gnt_list_entry = kzalloc(sizeof(struct grant), GFP_NOIO); |
292 | if (!gnt_list_entry) | |
293 | goto out_of_memory; | |
294 | ||
bfe11d6d RPM |
295 | if (info->feature_persistent) { |
296 | granted_page = alloc_page(GFP_NOIO); | |
297 | if (!granted_page) { | |
298 | kfree(gnt_list_entry); | |
299 | goto out_of_memory; | |
300 | } | |
a7a6df22 | 301 | gnt_list_entry->page = granted_page; |
9c1e050c RPM |
302 | } |
303 | ||
9c1e050c | 304 | gnt_list_entry->gref = GRANT_INVALID_REF; |
73716df7 | 305 | list_add(&gnt_list_entry->node, &rinfo->grants); |
9c1e050c RPM |
306 | i++; |
307 | } | |
308 | ||
309 | return 0; | |
310 | ||
311 | out_of_memory: | |
312 | list_for_each_entry_safe(gnt_list_entry, n, | |
73716df7 | 313 | &rinfo->grants, node) { |
9c1e050c | 314 | list_del(&gnt_list_entry->node); |
bfe11d6d | 315 | if (info->feature_persistent) |
a7a6df22 | 316 | __free_page(gnt_list_entry->page); |
9c1e050c RPM |
317 | kfree(gnt_list_entry); |
318 | i--; | |
319 | } | |
320 | BUG_ON(i != 0); | |
321 | return -ENOMEM; | |
322 | } | |
323 | ||
73716df7 | 324 | static struct grant *get_free_grant(struct blkfront_ring_info *rinfo) |
9c1e050c RPM |
325 | { |
326 | struct grant *gnt_list_entry; | |
9c1e050c | 327 | |
73716df7 BL |
328 | BUG_ON(list_empty(&rinfo->grants)); |
329 | gnt_list_entry = list_first_entry(&rinfo->grants, struct grant, | |
4f503fbd | 330 | node); |
9c1e050c RPM |
331 | list_del(&gnt_list_entry->node); |
332 | ||
4f503fbd | 333 | if (gnt_list_entry->gref != GRANT_INVALID_REF) |
73716df7 | 334 | rinfo->persistent_gnts_c--; |
4f503fbd JG |
335 | |
336 | return gnt_list_entry; | |
337 | } | |
338 | ||
339 | static inline void grant_foreign_access(const struct grant *gnt_list_entry, | |
340 | const struct blkfront_info *info) | |
341 | { | |
342 | gnttab_page_grant_foreign_access_ref_one(gnt_list_entry->gref, | |
343 | info->xbdev->otherend_id, | |
344 | gnt_list_entry->page, | |
345 | 0); | |
346 | } | |
347 | ||
348 | static struct grant *get_grant(grant_ref_t *gref_head, | |
349 | unsigned long gfn, | |
73716df7 | 350 | struct blkfront_ring_info *rinfo) |
4f503fbd | 351 | { |
73716df7 BL |
352 | struct grant *gnt_list_entry = get_free_grant(rinfo); |
353 | struct blkfront_info *info = rinfo->dev_info; | |
4f503fbd JG |
354 | |
355 | if (gnt_list_entry->gref != GRANT_INVALID_REF) | |
9c1e050c | 356 | return gnt_list_entry; |
4f503fbd JG |
357 | |
358 | /* Assign a gref to this page */ | |
359 | gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); | |
360 | BUG_ON(gnt_list_entry->gref == -ENOSPC); | |
361 | if (info->feature_persistent) | |
362 | grant_foreign_access(gnt_list_entry, info); | |
363 | else { | |
364 | /* Grant access to the GFN passed by the caller */ | |
365 | gnttab_grant_foreign_access_ref(gnt_list_entry->gref, | |
366 | info->xbdev->otherend_id, | |
367 | gfn, 0); | |
9c1e050c RPM |
368 | } |
369 | ||
4f503fbd JG |
370 | return gnt_list_entry; |
371 | } | |
372 | ||
373 | static struct grant *get_indirect_grant(grant_ref_t *gref_head, | |
73716df7 | 374 | struct blkfront_ring_info *rinfo) |
4f503fbd | 375 | { |
73716df7 BL |
376 | struct grant *gnt_list_entry = get_free_grant(rinfo); |
377 | struct blkfront_info *info = rinfo->dev_info; | |
4f503fbd JG |
378 | |
379 | if (gnt_list_entry->gref != GRANT_INVALID_REF) | |
380 | return gnt_list_entry; | |
381 | ||
9c1e050c RPM |
382 | /* Assign a gref to this page */ |
383 | gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head); | |
384 | BUG_ON(gnt_list_entry->gref == -ENOSPC); | |
bfe11d6d | 385 | if (!info->feature_persistent) { |
4f503fbd JG |
386 | struct page *indirect_page; |
387 | ||
388 | /* Fetch a pre-allocated page to use for indirect grefs */ | |
73716df7 BL |
389 | BUG_ON(list_empty(&rinfo->indirect_pages)); |
390 | indirect_page = list_first_entry(&rinfo->indirect_pages, | |
4f503fbd JG |
391 | struct page, lru); |
392 | list_del(&indirect_page->lru); | |
393 | gnt_list_entry->page = indirect_page; | |
bfe11d6d | 394 | } |
4f503fbd JG |
395 | grant_foreign_access(gnt_list_entry, info); |
396 | ||
9c1e050c RPM |
397 | return gnt_list_entry; |
398 | } | |
399 | ||
6878c32e KRW |
400 | static const char *op_name(int op) |
401 | { | |
402 | static const char *const names[] = { | |
403 | [BLKIF_OP_READ] = "read", | |
404 | [BLKIF_OP_WRITE] = "write", | |
405 | [BLKIF_OP_WRITE_BARRIER] = "barrier", | |
406 | [BLKIF_OP_FLUSH_DISKCACHE] = "flush", | |
407 | [BLKIF_OP_DISCARD] = "discard" }; | |
408 | ||
409 | if (op < 0 || op >= ARRAY_SIZE(names)) | |
410 | return "unknown"; | |
411 | ||
412 | if (!names[op]) | |
413 | return "reserved"; | |
414 | ||
415 | return names[op]; | |
416 | } | |
0e345826 JB |
417 | static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) |
418 | { | |
419 | unsigned int end = minor + nr; | |
420 | int rc; | |
421 | ||
422 | if (end > nr_minors) { | |
423 | unsigned long *bitmap, *old; | |
424 | ||
f094148a | 425 | bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap), |
0e345826 JB |
426 | GFP_KERNEL); |
427 | if (bitmap == NULL) | |
428 | return -ENOMEM; | |
429 | ||
430 | spin_lock(&minor_lock); | |
431 | if (end > nr_minors) { | |
432 | old = minors; | |
433 | memcpy(bitmap, minors, | |
434 | BITS_TO_LONGS(nr_minors) * sizeof(*bitmap)); | |
435 | minors = bitmap; | |
436 | nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG; | |
437 | } else | |
438 | old = bitmap; | |
439 | spin_unlock(&minor_lock); | |
440 | kfree(old); | |
441 | } | |
442 | ||
443 | spin_lock(&minor_lock); | |
444 | if (find_next_bit(minors, end, minor) >= end) { | |
34ae2e47 | 445 | bitmap_set(minors, minor, nr); |
0e345826 JB |
446 | rc = 0; |
447 | } else | |
448 | rc = -EBUSY; | |
449 | spin_unlock(&minor_lock); | |
450 | ||
451 | return rc; | |
452 | } | |
453 | ||
454 | static void xlbd_release_minors(unsigned int minor, unsigned int nr) | |
455 | { | |
456 | unsigned int end = minor + nr; | |
457 | ||
458 | BUG_ON(end > nr_minors); | |
459 | spin_lock(&minor_lock); | |
34ae2e47 | 460 | bitmap_clear(minors, minor, nr); |
0e345826 JB |
461 | spin_unlock(&minor_lock); |
462 | } | |
463 | ||
9f27ee59 JF |
464 | static void blkif_restart_queue_callback(void *arg) |
465 | { | |
81f35161 BL |
466 | struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)arg; |
467 | schedule_work(&rinfo->work); | |
9f27ee59 JF |
468 | } |
469 | ||
afe42d7d | 470 | static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg) |
597592d9 IC |
471 | { |
472 | /* We don't have real geometry info, but let's at least return | |
473 | values consistent with the size of the device */ | |
474 | sector_t nsect = get_capacity(bd->bd_disk); | |
475 | sector_t cylinders = nsect; | |
476 | ||
477 | hg->heads = 0xff; | |
478 | hg->sectors = 0x3f; | |
479 | sector_div(cylinders, hg->heads * hg->sectors); | |
480 | hg->cylinders = cylinders; | |
481 | if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect) | |
482 | hg->cylinders = 0xffff; | |
483 | return 0; | |
484 | } | |
485 | ||
a63c848b | 486 | static int blkif_ioctl(struct block_device *bdev, fmode_t mode, |
62aa0054 | 487 | unsigned command, unsigned long argument) |
440a01a7 | 488 | { |
a63c848b | 489 | struct blkfront_info *info = bdev->bd_disk->private_data; |
440a01a7 CL |
490 | int i; |
491 | ||
492 | dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n", | |
493 | command, (long)argument); | |
494 | ||
495 | switch (command) { | |
496 | case CDROMMULTISESSION: | |
497 | dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n"); | |
498 | for (i = 0; i < sizeof(struct cdrom_multisession); i++) | |
499 | if (put_user(0, (char __user *)(argument + i))) | |
500 | return -EFAULT; | |
501 | return 0; | |
502 | ||
503 | case CDROM_GET_CAPABILITY: { | |
504 | struct gendisk *gd = info->gd; | |
505 | if (gd->flags & GENHD_FL_CD) | |
506 | return 0; | |
507 | return -EINVAL; | |
508 | } | |
509 | ||
510 | default: | |
511 | /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n", | |
512 | command);*/ | |
513 | return -EINVAL; /* same return as native Linux */ | |
514 | } | |
515 | ||
516 | return 0; | |
517 | } | |
518 | ||
2e073969 JG |
519 | static unsigned long blkif_ring_get_request(struct blkfront_ring_info *rinfo, |
520 | struct request *req, | |
521 | struct blkif_request **ring_req) | |
522 | { | |
523 | unsigned long id; | |
524 | ||
525 | *ring_req = RING_GET_REQUEST(&rinfo->ring, rinfo->ring.req_prod_pvt); | |
526 | rinfo->ring.req_prod_pvt++; | |
527 | ||
528 | id = get_id_from_freelist(rinfo); | |
529 | rinfo->shadow[id].request = req; | |
6cc56833 JG |
530 | rinfo->shadow[id].status = REQ_WAITING; |
531 | rinfo->shadow[id].associated_id = NO_ASSOCIATED_ID; | |
2e073969 JG |
532 | |
533 | (*ring_req)->u.rw.id = id; | |
534 | ||
535 | return id; | |
536 | } | |
537 | ||
81f35161 | 538 | static int blkif_queue_discard_req(struct request *req, struct blkfront_ring_info *rinfo) |
9f27ee59 | 539 | { |
81f35161 | 540 | struct blkfront_info *info = rinfo->dev_info; |
9f27ee59 | 541 | struct blkif_request *ring_req; |
9f27ee59 | 542 | unsigned long id; |
33204663 JG |
543 | |
544 | /* Fill out a communications ring structure. */ | |
2e073969 | 545 | id = blkif_ring_get_request(rinfo, req, &ring_req); |
33204663 JG |
546 | |
547 | ring_req->operation = BLKIF_OP_DISCARD; | |
548 | ring_req->u.discard.nr_sectors = blk_rq_sectors(req); | |
549 | ring_req->u.discard.id = id; | |
550 | ring_req->u.discard.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
288dab8a | 551 | if (req_op(req) == REQ_OP_SECURE_ERASE && info->feature_secdiscard) |
33204663 JG |
552 | ring_req->u.discard.flag = BLKIF_DISCARD_SECURE; |
553 | else | |
554 | ring_req->u.discard.flag = 0; | |
555 | ||
33204663 | 556 | /* Keep a private copy so we can reissue requests when recovering. */ |
81f35161 | 557 | rinfo->shadow[id].req = *ring_req; |
33204663 JG |
558 | |
559 | return 0; | |
560 | } | |
561 | ||
c004a6fe JG |
562 | struct setup_rw_req { |
563 | unsigned int grant_idx; | |
564 | struct blkif_request_segment *segments; | |
81f35161 | 565 | struct blkfront_ring_info *rinfo; |
c004a6fe JG |
566 | struct blkif_request *ring_req; |
567 | grant_ref_t gref_head; | |
568 | unsigned int id; | |
569 | /* Only used when persistent grant is used and it's a read request */ | |
570 | bool need_copy; | |
571 | unsigned int bvec_off; | |
572 | char *bvec_data; | |
6cc56833 JG |
573 | |
574 | bool require_extra_req; | |
575 | struct blkif_request *extra_ring_req; | |
c004a6fe JG |
576 | }; |
577 | ||
578 | static void blkif_setup_rw_req_grant(unsigned long gfn, unsigned int offset, | |
579 | unsigned int len, void *data) | |
580 | { | |
581 | struct setup_rw_req *setup = data; | |
582 | int n, ref; | |
583 | struct grant *gnt_list_entry; | |
9f27ee59 | 584 | unsigned int fsect, lsect; |
c004a6fe JG |
585 | /* Convenient aliases */ |
586 | unsigned int grant_idx = setup->grant_idx; | |
587 | struct blkif_request *ring_req = setup->ring_req; | |
81f35161 | 588 | struct blkfront_ring_info *rinfo = setup->rinfo; |
6cc56833 JG |
589 | /* |
590 | * We always use the shadow of the first request to store the list | |
591 | * of grant associated to the block I/O request. This made the | |
592 | * completion more easy to handle even if the block I/O request is | |
593 | * split. | |
594 | */ | |
81f35161 | 595 | struct blk_shadow *shadow = &rinfo->shadow[setup->id]; |
c004a6fe | 596 | |
6cc56833 JG |
597 | if (unlikely(setup->require_extra_req && |
598 | grant_idx >= BLKIF_MAX_SEGMENTS_PER_REQUEST)) { | |
599 | /* | |
600 | * We are using the second request, setup grant_idx | |
601 | * to be the index of the segment array. | |
602 | */ | |
603 | grant_idx -= BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
604 | ring_req = setup->extra_ring_req; | |
605 | } | |
606 | ||
c004a6fe JG |
607 | if ((ring_req->operation == BLKIF_OP_INDIRECT) && |
608 | (grant_idx % GRANTS_PER_INDIRECT_FRAME == 0)) { | |
609 | if (setup->segments) | |
610 | kunmap_atomic(setup->segments); | |
611 | ||
612 | n = grant_idx / GRANTS_PER_INDIRECT_FRAME; | |
73716df7 | 613 | gnt_list_entry = get_indirect_grant(&setup->gref_head, rinfo); |
c004a6fe JG |
614 | shadow->indirect_grants[n] = gnt_list_entry; |
615 | setup->segments = kmap_atomic(gnt_list_entry->page); | |
616 | ring_req->u.indirect.indirect_grefs[n] = gnt_list_entry->gref; | |
617 | } | |
618 | ||
73716df7 | 619 | gnt_list_entry = get_grant(&setup->gref_head, gfn, rinfo); |
c004a6fe | 620 | ref = gnt_list_entry->gref; |
6cc56833 JG |
621 | /* |
622 | * All the grants are stored in the shadow of the first | |
623 | * request. Therefore we have to use the global index. | |
624 | */ | |
625 | shadow->grants_used[setup->grant_idx] = gnt_list_entry; | |
c004a6fe JG |
626 | |
627 | if (setup->need_copy) { | |
628 | void *shared_data; | |
629 | ||
630 | shared_data = kmap_atomic(gnt_list_entry->page); | |
631 | /* | |
632 | * this does not wipe data stored outside the | |
633 | * range sg->offset..sg->offset+sg->length. | |
634 | * Therefore, blkback *could* see data from | |
635 | * previous requests. This is OK as long as | |
636 | * persistent grants are shared with just one | |
637 | * domain. It may need refactoring if this | |
638 | * changes | |
639 | */ | |
640 | memcpy(shared_data + offset, | |
641 | setup->bvec_data + setup->bvec_off, | |
642 | len); | |
643 | ||
644 | kunmap_atomic(shared_data); | |
645 | setup->bvec_off += len; | |
646 | } | |
647 | ||
648 | fsect = offset >> 9; | |
649 | lsect = fsect + (len >> 9) - 1; | |
650 | if (ring_req->operation != BLKIF_OP_INDIRECT) { | |
651 | ring_req->u.rw.seg[grant_idx] = | |
652 | (struct blkif_request_segment) { | |
653 | .gref = ref, | |
654 | .first_sect = fsect, | |
655 | .last_sect = lsect }; | |
656 | } else { | |
657 | setup->segments[grant_idx % GRANTS_PER_INDIRECT_FRAME] = | |
658 | (struct blkif_request_segment) { | |
659 | .gref = ref, | |
660 | .first_sect = fsect, | |
661 | .last_sect = lsect }; | |
662 | } | |
663 | ||
664 | (setup->grant_idx)++; | |
665 | } | |
666 | ||
6cc56833 JG |
667 | static void blkif_setup_extra_req(struct blkif_request *first, |
668 | struct blkif_request *second) | |
669 | { | |
670 | uint16_t nr_segments = first->u.rw.nr_segments; | |
671 | ||
672 | /* | |
673 | * The second request is only present when the first request uses | |
674 | * all its segments. It's always the continuity of the first one. | |
675 | */ | |
676 | first->u.rw.nr_segments = BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
677 | ||
678 | second->u.rw.nr_segments = nr_segments - BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
679 | second->u.rw.sector_number = first->u.rw.sector_number + | |
680 | (BLKIF_MAX_SEGMENTS_PER_REQUEST * XEN_PAGE_SIZE) / 512; | |
681 | ||
682 | second->u.rw.handle = first->u.rw.handle; | |
683 | second->operation = first->operation; | |
684 | } | |
685 | ||
81f35161 | 686 | static int blkif_queue_rw_req(struct request *req, struct blkfront_ring_info *rinfo) |
9f27ee59 | 687 | { |
81f35161 | 688 | struct blkfront_info *info = rinfo->dev_info; |
6cc56833 JG |
689 | struct blkif_request *ring_req, *extra_ring_req = NULL; |
690 | unsigned long id, extra_id = NO_ASSOCIATED_ID; | |
691 | bool require_extra_req = false; | |
c004a6fe JG |
692 | int i; |
693 | struct setup_rw_req setup = { | |
694 | .grant_idx = 0, | |
695 | .segments = NULL, | |
81f35161 | 696 | .rinfo = rinfo, |
c004a6fe JG |
697 | .need_copy = rq_data_dir(req) && info->feature_persistent, |
698 | }; | |
0a8704a5 RPM |
699 | |
700 | /* | |
701 | * Used to store if we are able to queue the request by just using | |
702 | * existing persistent grants, or if we have to get new grants, | |
703 | * as there are not sufficiently many free. | |
704 | */ | |
9e973e64 | 705 | struct scatterlist *sg; |
c004a6fe | 706 | int num_sg, max_grefs, num_grant; |
9f27ee59 | 707 | |
c004a6fe | 708 | max_grefs = req->nr_phys_segments * GRANTS_PER_PSEG; |
c47206e2 RPM |
709 | if (max_grefs > BLKIF_MAX_SEGMENTS_PER_REQUEST) |
710 | /* | |
711 | * If we are using indirect segments we need to account | |
712 | * for the indirect grefs used in the request. | |
713 | */ | |
c004a6fe | 714 | max_grefs += INDIRECT_GREFS(max_grefs); |
402b27f9 | 715 | |
3df0e505 BL |
716 | /* |
717 | * We have to reserve 'max_grefs' grants because persistent | |
718 | * grants are shared by all rings. | |
719 | */ | |
720 | if (max_grefs > 0) | |
721 | if (gnttab_alloc_grant_references(max_grefs, &setup.gref_head) < 0) { | |
0a8704a5 | 722 | gnttab_request_free_callback( |
81f35161 | 723 | &rinfo->callback, |
0a8704a5 | 724 | blkif_restart_queue_callback, |
81f35161 | 725 | rinfo, |
402b27f9 | 726 | max_grefs); |
0a8704a5 RPM |
727 | return 1; |
728 | } | |
9f27ee59 JF |
729 | |
730 | /* Fill out a communications ring structure. */ | |
2e073969 | 731 | id = blkif_ring_get_request(rinfo, req, &ring_req); |
9f27ee59 | 732 | |
81f35161 | 733 | num_sg = blk_rq_map_sg(req->q, req, rinfo->shadow[id].sg); |
c004a6fe JG |
734 | num_grant = 0; |
735 | /* Calculate the number of grant used */ | |
81f35161 | 736 | for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i) |
c004a6fe JG |
737 | num_grant += gnttab_count_grant(sg->offset, sg->length); |
738 | ||
6cc56833 JG |
739 | require_extra_req = info->max_indirect_segments == 0 && |
740 | num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
741 | BUG_ON(!HAS_EXTRA_REQ && require_extra_req); | |
742 | ||
81f35161 | 743 | rinfo->shadow[id].num_sg = num_sg; |
6cc56833 JG |
744 | if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST && |
745 | likely(!require_extra_req)) { | |
33204663 JG |
746 | /* |
747 | * The indirect operation can only be a BLKIF_OP_READ or | |
748 | * BLKIF_OP_WRITE | |
749 | */ | |
3a5e02ce | 750 | BUG_ON(req_op(req) == REQ_OP_FLUSH || req->cmd_flags & REQ_FUA); |
33204663 JG |
751 | ring_req->operation = BLKIF_OP_INDIRECT; |
752 | ring_req->u.indirect.indirect_op = rq_data_dir(req) ? | |
753 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
754 | ring_req->u.indirect.sector_number = (blkif_sector_t)blk_rq_pos(req); | |
755 | ring_req->u.indirect.handle = info->handle; | |
c004a6fe | 756 | ring_req->u.indirect.nr_segments = num_grant; |
ed30bf31 | 757 | } else { |
33204663 JG |
758 | ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req); |
759 | ring_req->u.rw.handle = info->handle; | |
760 | ring_req->operation = rq_data_dir(req) ? | |
761 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
3a5e02ce | 762 | if (req_op(req) == REQ_OP_FLUSH || req->cmd_flags & REQ_FUA) { |
402b27f9 | 763 | /* |
33204663 JG |
764 | * Ideally we can do an unordered flush-to-disk. |
765 | * In case the backend onlysupports barriers, use that. | |
766 | * A barrier request a superset of FUA, so we can | |
767 | * implement it the same way. (It's also a FLUSH+FUA, | |
768 | * since it is guaranteed ordered WRT previous writes.) | |
402b27f9 | 769 | */ |
a418090a | 770 | if (info->feature_flush && info->feature_fua) |
33204663 JG |
771 | ring_req->operation = |
772 | BLKIF_OP_WRITE_BARRIER; | |
a418090a | 773 | else if (info->feature_flush) |
33204663 JG |
774 | ring_req->operation = |
775 | BLKIF_OP_FLUSH_DISKCACHE; | |
a418090a | 776 | else |
33204663 | 777 | ring_req->operation = 0; |
402b27f9 | 778 | } |
c004a6fe | 779 | ring_req->u.rw.nr_segments = num_grant; |
6cc56833 JG |
780 | if (unlikely(require_extra_req)) { |
781 | extra_id = blkif_ring_get_request(rinfo, req, | |
782 | &extra_ring_req); | |
783 | /* | |
784 | * Only the first request contains the scatter-gather | |
785 | * list. | |
786 | */ | |
787 | rinfo->shadow[extra_id].num_sg = 0; | |
788 | ||
789 | blkif_setup_extra_req(ring_req, extra_ring_req); | |
790 | ||
791 | /* Link the 2 requests together */ | |
792 | rinfo->shadow[extra_id].associated_id = id; | |
793 | rinfo->shadow[id].associated_id = extra_id; | |
794 | } | |
33204663 | 795 | } |
0a8704a5 | 796 | |
c004a6fe JG |
797 | setup.ring_req = ring_req; |
798 | setup.id = id; | |
6cc56833 JG |
799 | |
800 | setup.require_extra_req = require_extra_req; | |
801 | if (unlikely(require_extra_req)) | |
802 | setup.extra_ring_req = extra_ring_req; | |
803 | ||
81f35161 | 804 | for_each_sg(rinfo->shadow[id].sg, sg, num_sg, i) { |
c004a6fe | 805 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); |
0a8704a5 | 806 | |
c004a6fe JG |
807 | if (setup.need_copy) { |
808 | setup.bvec_off = sg->offset; | |
809 | setup.bvec_data = kmap_atomic(sg_page(sg)); | |
810 | } | |
0a8704a5 | 811 | |
c004a6fe JG |
812 | gnttab_foreach_grant_in_range(sg_page(sg), |
813 | sg->offset, | |
814 | sg->length, | |
815 | blkif_setup_rw_req_grant, | |
816 | &setup); | |
0a8704a5 | 817 | |
c004a6fe JG |
818 | if (setup.need_copy) |
819 | kunmap_atomic(setup.bvec_data); | |
9f27ee59 | 820 | } |
c004a6fe JG |
821 | if (setup.segments) |
822 | kunmap_atomic(setup.segments); | |
9f27ee59 | 823 | |
9f27ee59 | 824 | /* Keep a private copy so we can reissue requests when recovering. */ |
81f35161 | 825 | rinfo->shadow[id].req = *ring_req; |
6cc56833 JG |
826 | if (unlikely(require_extra_req)) |
827 | rinfo->shadow[extra_id].req = *extra_ring_req; | |
9f27ee59 | 828 | |
3df0e505 | 829 | if (max_grefs > 0) |
c004a6fe | 830 | gnttab_free_grant_references(setup.gref_head); |
9f27ee59 JF |
831 | |
832 | return 0; | |
833 | } | |
834 | ||
33204663 JG |
835 | /* |
836 | * Generate a Xen blkfront IO request from a blk layer request. Reads | |
837 | * and writes are handled as expected. | |
838 | * | |
839 | * @req: a request struct | |
840 | */ | |
81f35161 | 841 | static int blkif_queue_request(struct request *req, struct blkfront_ring_info *rinfo) |
33204663 | 842 | { |
81f35161 | 843 | if (unlikely(rinfo->dev_info->connected != BLKIF_STATE_CONNECTED)) |
33204663 JG |
844 | return 1; |
845 | ||
c2df40df | 846 | if (unlikely(req_op(req) == REQ_OP_DISCARD || |
288dab8a | 847 | req_op(req) == REQ_OP_SECURE_ERASE)) |
81f35161 | 848 | return blkif_queue_discard_req(req, rinfo); |
33204663 | 849 | else |
81f35161 | 850 | return blkif_queue_rw_req(req, rinfo); |
33204663 | 851 | } |
9f27ee59 | 852 | |
81f35161 | 853 | static inline void flush_requests(struct blkfront_ring_info *rinfo) |
9f27ee59 JF |
854 | { |
855 | int notify; | |
856 | ||
81f35161 | 857 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&rinfo->ring, notify); |
9f27ee59 JF |
858 | |
859 | if (notify) | |
81f35161 | 860 | notify_remote_via_irq(rinfo->irq); |
9f27ee59 JF |
861 | } |
862 | ||
ad42d391 VK |
863 | static inline bool blkif_request_flush_invalid(struct request *req, |
864 | struct blkfront_info *info) | |
0f1ca65e AA |
865 | { |
866 | return ((req->cmd_type != REQ_TYPE_FS) || | |
3a5e02ce | 867 | ((req_op(req) == REQ_OP_FLUSH) && |
a418090a | 868 | !info->feature_flush) || |
ad42d391 | 869 | ((req->cmd_flags & REQ_FUA) && |
a418090a | 870 | !info->feature_fua)); |
0f1ca65e AA |
871 | } |
872 | ||
907c3eb1 | 873 | static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx, |
6f03a7ff | 874 | const struct blk_mq_queue_data *qd) |
9f27ee59 | 875 | { |
11659569 | 876 | unsigned long flags; |
2a6f71ad BL |
877 | int qid = hctx->queue_num; |
878 | struct blkfront_info *info = hctx->queue->queuedata; | |
879 | struct blkfront_ring_info *rinfo = NULL; | |
9f27ee59 | 880 | |
2a6f71ad BL |
881 | BUG_ON(info->nr_rings <= qid); |
882 | rinfo = &info->rinfo[qid]; | |
907c3eb1 | 883 | blk_mq_start_request(qd->rq); |
11659569 | 884 | spin_lock_irqsave(&rinfo->ring_lock, flags); |
81f35161 | 885 | if (RING_FULL(&rinfo->ring)) |
907c3eb1 | 886 | goto out_busy; |
9f27ee59 | 887 | |
81f35161 | 888 | if (blkif_request_flush_invalid(qd->rq, rinfo->dev_info)) |
907c3eb1 | 889 | goto out_err; |
296b2f6a | 890 | |
81f35161 | 891 | if (blkif_queue_request(qd->rq, rinfo)) |
907c3eb1 | 892 | goto out_busy; |
296b2f6a | 893 | |
81f35161 | 894 | flush_requests(rinfo); |
11659569 | 895 | spin_unlock_irqrestore(&rinfo->ring_lock, flags); |
907c3eb1 | 896 | return BLK_MQ_RQ_QUEUE_OK; |
9f27ee59 | 897 | |
907c3eb1 | 898 | out_err: |
11659569 | 899 | spin_unlock_irqrestore(&rinfo->ring_lock, flags); |
907c3eb1 | 900 | return BLK_MQ_RQ_QUEUE_ERROR; |
9f27ee59 | 901 | |
907c3eb1 | 902 | out_busy: |
11659569 | 903 | spin_unlock_irqrestore(&rinfo->ring_lock, flags); |
907c3eb1 BL |
904 | blk_mq_stop_hw_queue(hctx); |
905 | return BLK_MQ_RQ_QUEUE_BUSY; | |
9f27ee59 JF |
906 | } |
907 | ||
907c3eb1 BL |
908 | static struct blk_mq_ops blkfront_mq_ops = { |
909 | .queue_rq = blkif_queue_rq, | |
910 | .map_queue = blk_mq_map_queue, | |
911 | }; | |
912 | ||
402b27f9 | 913 | static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, |
7c4d7d71 | 914 | unsigned int physical_sector_size, |
402b27f9 | 915 | unsigned int segments) |
9f27ee59 | 916 | { |
165125e1 | 917 | struct request_queue *rq; |
ed30bf31 | 918 | struct blkfront_info *info = gd->private_data; |
9f27ee59 | 919 | |
907c3eb1 BL |
920 | memset(&info->tag_set, 0, sizeof(info->tag_set)); |
921 | info->tag_set.ops = &blkfront_mq_ops; | |
28d949bc | 922 | info->tag_set.nr_hw_queues = info->nr_rings; |
6cc56833 JG |
923 | if (HAS_EXTRA_REQ && info->max_indirect_segments == 0) { |
924 | /* | |
925 | * When indirect descriptior is not supported, the I/O request | |
926 | * will be split between multiple request in the ring. | |
927 | * To avoid problems when sending the request, divide by | |
928 | * 2 the depth of the queue. | |
929 | */ | |
930 | info->tag_set.queue_depth = BLK_RING_SIZE(info) / 2; | |
931 | } else | |
932 | info->tag_set.queue_depth = BLK_RING_SIZE(info); | |
907c3eb1 BL |
933 | info->tag_set.numa_node = NUMA_NO_NODE; |
934 | info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE; | |
935 | info->tag_set.cmd_size = 0; | |
936 | info->tag_set.driver_data = info; | |
937 | ||
938 | if (blk_mq_alloc_tag_set(&info->tag_set)) | |
bde21f73 | 939 | return -EINVAL; |
907c3eb1 BL |
940 | rq = blk_mq_init_queue(&info->tag_set); |
941 | if (IS_ERR(rq)) { | |
942 | blk_mq_free_tag_set(&info->tag_set); | |
bde21f73 | 943 | return PTR_ERR(rq); |
907c3eb1 | 944 | } |
9f27ee59 | 945 | |
2a6f71ad | 946 | rq->queuedata = info; |
66d352e1 | 947 | queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); |
9f27ee59 | 948 | |
ed30bf31 LD |
949 | if (info->feature_discard) { |
950 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, rq); | |
951 | blk_queue_max_discard_sectors(rq, get_capacity(gd)); | |
952 | rq->limits.discard_granularity = info->discard_granularity; | |
953 | rq->limits.discard_alignment = info->discard_alignment; | |
5ea42986 | 954 | if (info->feature_secdiscard) |
288dab8a | 955 | queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, rq); |
ed30bf31 LD |
956 | } |
957 | ||
9f27ee59 | 958 | /* Hard sector size and max sectors impersonate the equiv. hardware. */ |
e1defc4f | 959 | blk_queue_logical_block_size(rq, sector_size); |
7c4d7d71 | 960 | blk_queue_physical_block_size(rq, physical_sector_size); |
c004a6fe | 961 | blk_queue_max_hw_sectors(rq, (segments * XEN_PAGE_SIZE) / 512); |
9f27ee59 JF |
962 | |
963 | /* Each segment in a request is up to an aligned page in size. */ | |
964 | blk_queue_segment_boundary(rq, PAGE_SIZE - 1); | |
965 | blk_queue_max_segment_size(rq, PAGE_SIZE); | |
966 | ||
967 | /* Ensure a merged request will fit in a single I/O ring slot. */ | |
c004a6fe | 968 | blk_queue_max_segments(rq, segments / GRANTS_PER_PSEG); |
9f27ee59 JF |
969 | |
970 | /* Make sure buffer addresses are sector-aligned. */ | |
971 | blk_queue_dma_alignment(rq, 511); | |
972 | ||
1c91fe1a IC |
973 | /* Make sure we don't use bounce buffers. */ |
974 | blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY); | |
975 | ||
9f27ee59 JF |
976 | gd->queue = rq; |
977 | ||
978 | return 0; | |
979 | } | |
980 | ||
a418090a | 981 | static const char *flush_info(struct blkfront_info *info) |
fdf9b965 | 982 | { |
a418090a | 983 | if (info->feature_flush && info->feature_fua) |
fdf9b965 | 984 | return "barrier: enabled;"; |
a418090a | 985 | else if (info->feature_flush) |
fdf9b965 | 986 | return "flush diskcache: enabled;"; |
a418090a | 987 | else |
fdf9b965 | 988 | return "barrier or flush: disabled;"; |
fdf9b965 | 989 | } |
9f27ee59 | 990 | |
4913efe4 | 991 | static void xlvbd_flush(struct blkfront_info *info) |
9f27ee59 | 992 | { |
a418090a MC |
993 | blk_queue_write_cache(info->rq, info->feature_flush ? true : false, |
994 | info->feature_fua ? true : false); | |
fdf9b965 | 995 | pr_info("blkfront: %s: %s %s %s %s %s\n", |
a418090a | 996 | info->gd->disk_name, flush_info(info), |
fdf9b965 VK |
997 | "persistent grants:", info->feature_persistent ? |
998 | "enabled;" : "disabled;", "indirect descriptors:", | |
999 | info->max_indirect_segments ? "enabled;" : "disabled;"); | |
9f27ee59 JF |
1000 | } |
1001 | ||
c80a4209 SS |
1002 | static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) |
1003 | { | |
1004 | int major; | |
1005 | major = BLKIF_MAJOR(vdevice); | |
1006 | *minor = BLKIF_MINOR(vdevice); | |
1007 | switch (major) { | |
1008 | case XEN_IDE0_MAJOR: | |
1009 | *offset = (*minor / 64) + EMULATED_HD_DISK_NAME_OFFSET; | |
1010 | *minor = ((*minor / 64) * PARTS_PER_DISK) + | |
1011 | EMULATED_HD_DISK_MINOR_OFFSET; | |
1012 | break; | |
1013 | case XEN_IDE1_MAJOR: | |
1014 | *offset = (*minor / 64) + 2 + EMULATED_HD_DISK_NAME_OFFSET; | |
1015 | *minor = (((*minor / 64) + 2) * PARTS_PER_DISK) + | |
1016 | EMULATED_HD_DISK_MINOR_OFFSET; | |
1017 | break; | |
1018 | case XEN_SCSI_DISK0_MAJOR: | |
1019 | *offset = (*minor / PARTS_PER_DISK) + EMULATED_SD_DISK_NAME_OFFSET; | |
1020 | *minor = *minor + EMULATED_SD_DISK_MINOR_OFFSET; | |
1021 | break; | |
1022 | case XEN_SCSI_DISK1_MAJOR: | |
1023 | case XEN_SCSI_DISK2_MAJOR: | |
1024 | case XEN_SCSI_DISK3_MAJOR: | |
1025 | case XEN_SCSI_DISK4_MAJOR: | |
1026 | case XEN_SCSI_DISK5_MAJOR: | |
1027 | case XEN_SCSI_DISK6_MAJOR: | |
1028 | case XEN_SCSI_DISK7_MAJOR: | |
1029 | *offset = (*minor / PARTS_PER_DISK) + | |
1030 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16) + | |
1031 | EMULATED_SD_DISK_NAME_OFFSET; | |
1032 | *minor = *minor + | |
1033 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16 * PARTS_PER_DISK) + | |
1034 | EMULATED_SD_DISK_MINOR_OFFSET; | |
1035 | break; | |
1036 | case XEN_SCSI_DISK8_MAJOR: | |
1037 | case XEN_SCSI_DISK9_MAJOR: | |
1038 | case XEN_SCSI_DISK10_MAJOR: | |
1039 | case XEN_SCSI_DISK11_MAJOR: | |
1040 | case XEN_SCSI_DISK12_MAJOR: | |
1041 | case XEN_SCSI_DISK13_MAJOR: | |
1042 | case XEN_SCSI_DISK14_MAJOR: | |
1043 | case XEN_SCSI_DISK15_MAJOR: | |
1044 | *offset = (*minor / PARTS_PER_DISK) + | |
1045 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16) + | |
1046 | EMULATED_SD_DISK_NAME_OFFSET; | |
1047 | *minor = *minor + | |
1048 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16 * PARTS_PER_DISK) + | |
1049 | EMULATED_SD_DISK_MINOR_OFFSET; | |
1050 | break; | |
1051 | case XENVBD_MAJOR: | |
1052 | *offset = *minor / PARTS_PER_DISK; | |
1053 | break; | |
1054 | default: | |
1055 | printk(KERN_WARNING "blkfront: your disk configuration is " | |
1056 | "incorrect, please use an xvd device instead\n"); | |
1057 | return -ENODEV; | |
1058 | } | |
1059 | return 0; | |
1060 | } | |
9f27ee59 | 1061 | |
e77c78c0 JB |
1062 | static char *encode_disk_name(char *ptr, unsigned int n) |
1063 | { | |
1064 | if (n >= 26) | |
1065 | ptr = encode_disk_name(ptr, n / 26 - 1); | |
1066 | *ptr = 'a' + n % 26; | |
1067 | return ptr + 1; | |
1068 | } | |
1069 | ||
9246b5f0 CL |
1070 | static int xlvbd_alloc_gendisk(blkif_sector_t capacity, |
1071 | struct blkfront_info *info, | |
7c4d7d71 SB |
1072 | u16 vdisk_info, u16 sector_size, |
1073 | unsigned int physical_sector_size) | |
9f27ee59 JF |
1074 | { |
1075 | struct gendisk *gd; | |
1076 | int nr_minors = 1; | |
c80a4209 | 1077 | int err; |
9246b5f0 CL |
1078 | unsigned int offset; |
1079 | int minor; | |
1080 | int nr_parts; | |
e77c78c0 | 1081 | char *ptr; |
9f27ee59 JF |
1082 | |
1083 | BUG_ON(info->gd != NULL); | |
1084 | BUG_ON(info->rq != NULL); | |
1085 | ||
9246b5f0 CL |
1086 | if ((info->vdevice>>EXT_SHIFT) > 1) { |
1087 | /* this is above the extended range; something is wrong */ | |
1088 | printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice); | |
1089 | return -ENODEV; | |
1090 | } | |
1091 | ||
1092 | if (!VDEV_IS_EXTENDED(info->vdevice)) { | |
c80a4209 SS |
1093 | err = xen_translate_vdev(info->vdevice, &minor, &offset); |
1094 | if (err) | |
1095 | return err; | |
1096 | nr_parts = PARTS_PER_DISK; | |
9246b5f0 CL |
1097 | } else { |
1098 | minor = BLKIF_MINOR_EXT(info->vdevice); | |
1099 | nr_parts = PARTS_PER_EXT_DISK; | |
c80a4209 | 1100 | offset = minor / nr_parts; |
89153b5c | 1101 | if (xen_hvm_domain() && offset < EMULATED_HD_DISK_NAME_OFFSET + 4) |
c80a4209 SS |
1102 | printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with " |
1103 | "emulated IDE disks,\n\t choose an xvd device name" | |
1104 | "from xvde on\n", info->vdevice); | |
9246b5f0 | 1105 | } |
e77c78c0 JB |
1106 | if (minor >> MINORBITS) { |
1107 | pr_warn("blkfront: %#x's minor (%#x) out of range; ignoring\n", | |
1108 | info->vdevice, minor); | |
1109 | return -ENODEV; | |
1110 | } | |
9246b5f0 CL |
1111 | |
1112 | if ((minor % nr_parts) == 0) | |
1113 | nr_minors = nr_parts; | |
9f27ee59 | 1114 | |
0e345826 JB |
1115 | err = xlbd_reserve_minors(minor, nr_minors); |
1116 | if (err) | |
1117 | goto out; | |
1118 | err = -ENODEV; | |
1119 | ||
9f27ee59 JF |
1120 | gd = alloc_disk(nr_minors); |
1121 | if (gd == NULL) | |
0e345826 | 1122 | goto release; |
9f27ee59 | 1123 | |
e77c78c0 JB |
1124 | strcpy(gd->disk_name, DEV_NAME); |
1125 | ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset); | |
1126 | BUG_ON(ptr >= gd->disk_name + DISK_NAME_LEN); | |
1127 | if (nr_minors > 1) | |
1128 | *ptr = 0; | |
1129 | else | |
1130 | snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr, | |
1131 | "%d", minor & (nr_parts - 1)); | |
9f27ee59 JF |
1132 | |
1133 | gd->major = XENVBD_MAJOR; | |
1134 | gd->first_minor = minor; | |
1135 | gd->fops = &xlvbd_block_fops; | |
1136 | gd->private_data = info; | |
9f27ee59 JF |
1137 | set_capacity(gd, capacity); |
1138 | ||
7c4d7d71 | 1139 | if (xlvbd_init_blk_queue(gd, sector_size, physical_sector_size, |
402b27f9 RPM |
1140 | info->max_indirect_segments ? : |
1141 | BLKIF_MAX_SEGMENTS_PER_REQUEST)) { | |
9f27ee59 | 1142 | del_gendisk(gd); |
0e345826 | 1143 | goto release; |
9f27ee59 JF |
1144 | } |
1145 | ||
1146 | info->rq = gd->queue; | |
1147 | info->gd = gd; | |
1148 | ||
4913efe4 | 1149 | xlvbd_flush(info); |
9f27ee59 JF |
1150 | |
1151 | if (vdisk_info & VDISK_READONLY) | |
1152 | set_disk_ro(gd, 1); | |
1153 | ||
1154 | if (vdisk_info & VDISK_REMOVABLE) | |
1155 | gd->flags |= GENHD_FL_REMOVABLE; | |
1156 | ||
1157 | if (vdisk_info & VDISK_CDROM) | |
1158 | gd->flags |= GENHD_FL_CD; | |
1159 | ||
1160 | return 0; | |
1161 | ||
0e345826 JB |
1162 | release: |
1163 | xlbd_release_minors(minor, nr_minors); | |
9f27ee59 JF |
1164 | out: |
1165 | return err; | |
1166 | } | |
1167 | ||
a66b5aeb DS |
1168 | static void xlvbd_release_gendisk(struct blkfront_info *info) |
1169 | { | |
3df0e505 | 1170 | unsigned int minor, nr_minors, i; |
a66b5aeb DS |
1171 | |
1172 | if (info->rq == NULL) | |
1173 | return; | |
1174 | ||
a66b5aeb | 1175 | /* No more blkif_request(). */ |
907c3eb1 | 1176 | blk_mq_stop_hw_queues(info->rq); |
a66b5aeb | 1177 | |
3df0e505 BL |
1178 | for (i = 0; i < info->nr_rings; i++) { |
1179 | struct blkfront_ring_info *rinfo = &info->rinfo[i]; | |
a66b5aeb | 1180 | |
3df0e505 BL |
1181 | /* No more gnttab callback work. */ |
1182 | gnttab_cancel_free_callback(&rinfo->callback); | |
1183 | ||
1184 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
1185 | flush_work(&rinfo->work); | |
1186 | } | |
a66b5aeb DS |
1187 | |
1188 | del_gendisk(info->gd); | |
1189 | ||
1190 | minor = info->gd->first_minor; | |
1191 | nr_minors = info->gd->minors; | |
1192 | xlbd_release_minors(minor, nr_minors); | |
1193 | ||
1194 | blk_cleanup_queue(info->rq); | |
907c3eb1 | 1195 | blk_mq_free_tag_set(&info->tag_set); |
a66b5aeb DS |
1196 | info->rq = NULL; |
1197 | ||
1198 | put_disk(info->gd); | |
1199 | info->gd = NULL; | |
1200 | } | |
1201 | ||
11659569 BL |
1202 | /* Already hold rinfo->ring_lock. */ |
1203 | static inline void kick_pending_request_queues_locked(struct blkfront_ring_info *rinfo) | |
9f27ee59 | 1204 | { |
81f35161 BL |
1205 | if (!RING_FULL(&rinfo->ring)) |
1206 | blk_mq_start_stopped_hw_queues(rinfo->dev_info->rq, true); | |
9f27ee59 JF |
1207 | } |
1208 | ||
11659569 BL |
1209 | static void kick_pending_request_queues(struct blkfront_ring_info *rinfo) |
1210 | { | |
1211 | unsigned long flags; | |
1212 | ||
1213 | spin_lock_irqsave(&rinfo->ring_lock, flags); | |
1214 | kick_pending_request_queues_locked(rinfo); | |
1215 | spin_unlock_irqrestore(&rinfo->ring_lock, flags); | |
1216 | } | |
1217 | ||
9f27ee59 JF |
1218 | static void blkif_restart_queue(struct work_struct *work) |
1219 | { | |
81f35161 | 1220 | struct blkfront_ring_info *rinfo = container_of(work, struct blkfront_ring_info, work); |
9f27ee59 | 1221 | |
81f35161 BL |
1222 | if (rinfo->dev_info->connected == BLKIF_STATE_CONNECTED) |
1223 | kick_pending_request_queues(rinfo); | |
9f27ee59 JF |
1224 | } |
1225 | ||
3df0e505 | 1226 | static void blkif_free_ring(struct blkfront_ring_info *rinfo) |
9f27ee59 | 1227 | { |
73716df7 | 1228 | struct grant *persistent_gnt, *n; |
3df0e505 | 1229 | struct blkfront_info *info = rinfo->dev_info; |
402b27f9 | 1230 | int i, j, segs; |
0a8704a5 | 1231 | |
bfe11d6d RPM |
1232 | /* |
1233 | * Remove indirect pages, this only happens when using indirect | |
1234 | * descriptors but not persistent grants | |
1235 | */ | |
81f35161 | 1236 | if (!list_empty(&rinfo->indirect_pages)) { |
bfe11d6d RPM |
1237 | struct page *indirect_page, *n; |
1238 | ||
1239 | BUG_ON(info->feature_persistent); | |
81f35161 | 1240 | list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) { |
bfe11d6d RPM |
1241 | list_del(&indirect_page->lru); |
1242 | __free_page(indirect_page); | |
1243 | } | |
1244 | } | |
1245 | ||
73716df7 BL |
1246 | /* Remove all persistent grants. */ |
1247 | if (!list_empty(&rinfo->grants)) { | |
1248 | list_for_each_entry_safe(persistent_gnt, n, | |
1249 | &rinfo->grants, node) { | |
1250 | list_del(&persistent_gnt->node); | |
1251 | if (persistent_gnt->gref != GRANT_INVALID_REF) { | |
1252 | gnttab_end_foreign_access(persistent_gnt->gref, | |
1253 | 0, 0UL); | |
1254 | rinfo->persistent_gnts_c--; | |
1255 | } | |
1256 | if (info->feature_persistent) | |
1257 | __free_page(persistent_gnt->page); | |
1258 | kfree(persistent_gnt); | |
1259 | } | |
1260 | } | |
1261 | BUG_ON(rinfo->persistent_gnts_c != 0); | |
1262 | ||
86839c56 | 1263 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
402b27f9 RPM |
1264 | /* |
1265 | * Clear persistent grants present in requests already | |
1266 | * on the shared ring | |
1267 | */ | |
81f35161 | 1268 | if (!rinfo->shadow[i].request) |
402b27f9 RPM |
1269 | goto free_shadow; |
1270 | ||
81f35161 BL |
1271 | segs = rinfo->shadow[i].req.operation == BLKIF_OP_INDIRECT ? |
1272 | rinfo->shadow[i].req.u.indirect.nr_segments : | |
1273 | rinfo->shadow[i].req.u.rw.nr_segments; | |
402b27f9 | 1274 | for (j = 0; j < segs; j++) { |
81f35161 | 1275 | persistent_gnt = rinfo->shadow[i].grants_used[j]; |
402b27f9 | 1276 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); |
bfe11d6d | 1277 | if (info->feature_persistent) |
a7a6df22 | 1278 | __free_page(persistent_gnt->page); |
402b27f9 RPM |
1279 | kfree(persistent_gnt); |
1280 | } | |
1281 | ||
81f35161 | 1282 | if (rinfo->shadow[i].req.operation != BLKIF_OP_INDIRECT) |
402b27f9 RPM |
1283 | /* |
1284 | * If this is not an indirect operation don't try to | |
1285 | * free indirect segments | |
1286 | */ | |
1287 | goto free_shadow; | |
1288 | ||
1289 | for (j = 0; j < INDIRECT_GREFS(segs); j++) { | |
81f35161 | 1290 | persistent_gnt = rinfo->shadow[i].indirect_grants[j]; |
402b27f9 | 1291 | gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); |
a7a6df22 | 1292 | __free_page(persistent_gnt->page); |
402b27f9 RPM |
1293 | kfree(persistent_gnt); |
1294 | } | |
1295 | ||
1296 | free_shadow: | |
81f35161 BL |
1297 | kfree(rinfo->shadow[i].grants_used); |
1298 | rinfo->shadow[i].grants_used = NULL; | |
1299 | kfree(rinfo->shadow[i].indirect_grants); | |
1300 | rinfo->shadow[i].indirect_grants = NULL; | |
1301 | kfree(rinfo->shadow[i].sg); | |
1302 | rinfo->shadow[i].sg = NULL; | |
402b27f9 RPM |
1303 | } |
1304 | ||
9f27ee59 | 1305 | /* No more gnttab callback work. */ |
81f35161 | 1306 | gnttab_cancel_free_callback(&rinfo->callback); |
9f27ee59 JF |
1307 | |
1308 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
81f35161 | 1309 | flush_work(&rinfo->work); |
9f27ee59 JF |
1310 | |
1311 | /* Free resources associated with old device channel. */ | |
86839c56 | 1312 | for (i = 0; i < info->nr_ring_pages; i++) { |
81f35161 BL |
1313 | if (rinfo->ring_ref[i] != GRANT_INVALID_REF) { |
1314 | gnttab_end_foreign_access(rinfo->ring_ref[i], 0, 0); | |
1315 | rinfo->ring_ref[i] = GRANT_INVALID_REF; | |
86839c56 | 1316 | } |
9f27ee59 | 1317 | } |
81f35161 BL |
1318 | free_pages((unsigned long)rinfo->ring.sring, get_order(info->nr_ring_pages * PAGE_SIZE)); |
1319 | rinfo->ring.sring = NULL; | |
86839c56 | 1320 | |
81f35161 BL |
1321 | if (rinfo->irq) |
1322 | unbind_from_irqhandler(rinfo->irq, rinfo); | |
1323 | rinfo->evtchn = rinfo->irq = 0; | |
3df0e505 | 1324 | } |
9f27ee59 | 1325 | |
3df0e505 BL |
1326 | static void blkif_free(struct blkfront_info *info, int suspend) |
1327 | { | |
3df0e505 BL |
1328 | unsigned int i; |
1329 | ||
1330 | /* Prevent new requests being issued until we fix things up. */ | |
3df0e505 BL |
1331 | info->connected = suspend ? |
1332 | BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; | |
1333 | /* No more blkif_request(). */ | |
1334 | if (info->rq) | |
1335 | blk_mq_stop_hw_queues(info->rq); | |
1336 | ||
3df0e505 BL |
1337 | for (i = 0; i < info->nr_rings; i++) |
1338 | blkif_free_ring(&info->rinfo[i]); | |
1339 | ||
1340 | kfree(info->rinfo); | |
1341 | info->rinfo = NULL; | |
1342 | info->nr_rings = 0; | |
9f27ee59 JF |
1343 | } |
1344 | ||
c004a6fe JG |
1345 | struct copy_from_grant { |
1346 | const struct blk_shadow *s; | |
1347 | unsigned int grant_idx; | |
1348 | unsigned int bvec_offset; | |
1349 | char *bvec_data; | |
1350 | }; | |
1351 | ||
1352 | static void blkif_copy_from_grant(unsigned long gfn, unsigned int offset, | |
1353 | unsigned int len, void *data) | |
1354 | { | |
1355 | struct copy_from_grant *info = data; | |
1356 | char *shared_data; | |
1357 | /* Convenient aliases */ | |
1358 | const struct blk_shadow *s = info->s; | |
1359 | ||
1360 | shared_data = kmap_atomic(s->grants_used[info->grant_idx]->page); | |
1361 | ||
1362 | memcpy(info->bvec_data + info->bvec_offset, | |
1363 | shared_data + offset, len); | |
1364 | ||
1365 | info->bvec_offset += len; | |
1366 | info->grant_idx++; | |
1367 | ||
1368 | kunmap_atomic(shared_data); | |
1369 | } | |
1370 | ||
6cc56833 JG |
1371 | static enum blk_req_status blkif_rsp_to_req_status(int rsp) |
1372 | { | |
1373 | switch (rsp) | |
1374 | { | |
1375 | case BLKIF_RSP_OKAY: | |
1376 | return REQ_DONE; | |
1377 | case BLKIF_RSP_EOPNOTSUPP: | |
1378 | return REQ_EOPNOTSUPP; | |
1379 | case BLKIF_RSP_ERROR: | |
1380 | /* Fallthrough. */ | |
1381 | default: | |
1382 | return REQ_ERROR; | |
1383 | } | |
1384 | } | |
1385 | ||
1386 | /* | |
1387 | * Get the final status of the block request based on two ring response | |
1388 | */ | |
1389 | static int blkif_get_final_status(enum blk_req_status s1, | |
1390 | enum blk_req_status s2) | |
1391 | { | |
1392 | BUG_ON(s1 == REQ_WAITING); | |
1393 | BUG_ON(s2 == REQ_WAITING); | |
1394 | ||
1395 | if (s1 == REQ_ERROR || s2 == REQ_ERROR) | |
1396 | return BLKIF_RSP_ERROR; | |
1397 | else if (s1 == REQ_EOPNOTSUPP || s2 == REQ_EOPNOTSUPP) | |
1398 | return BLKIF_RSP_EOPNOTSUPP; | |
1399 | return BLKIF_RSP_OKAY; | |
1400 | } | |
1401 | ||
1402 | static bool blkif_completion(unsigned long *id, | |
1403 | struct blkfront_ring_info *rinfo, | |
0a8704a5 | 1404 | struct blkif_response *bret) |
9f27ee59 | 1405 | { |
d62f6918 | 1406 | int i = 0; |
b7649158 | 1407 | struct scatterlist *sg; |
c004a6fe | 1408 | int num_sg, num_grant; |
81f35161 | 1409 | struct blkfront_info *info = rinfo->dev_info; |
6cc56833 | 1410 | struct blk_shadow *s = &rinfo->shadow[*id]; |
c004a6fe | 1411 | struct copy_from_grant data = { |
c004a6fe JG |
1412 | .grant_idx = 0, |
1413 | }; | |
402b27f9 | 1414 | |
c004a6fe | 1415 | num_grant = s->req.operation == BLKIF_OP_INDIRECT ? |
402b27f9 | 1416 | s->req.u.indirect.nr_segments : s->req.u.rw.nr_segments; |
6cc56833 JG |
1417 | |
1418 | /* The I/O request may be split in two. */ | |
1419 | if (unlikely(s->associated_id != NO_ASSOCIATED_ID)) { | |
1420 | struct blk_shadow *s2 = &rinfo->shadow[s->associated_id]; | |
1421 | ||
1422 | /* Keep the status of the current response in shadow. */ | |
1423 | s->status = blkif_rsp_to_req_status(bret->status); | |
1424 | ||
1425 | /* Wait the second response if not yet here. */ | |
1426 | if (s2->status == REQ_WAITING) | |
1427 | return 0; | |
1428 | ||
1429 | bret->status = blkif_get_final_status(s->status, | |
1430 | s2->status); | |
1431 | ||
1432 | /* | |
1433 | * All the grants is stored in the first shadow in order | |
1434 | * to make the completion code simpler. | |
1435 | */ | |
1436 | num_grant += s2->req.u.rw.nr_segments; | |
1437 | ||
1438 | /* | |
1439 | * The two responses may not come in order. Only the | |
1440 | * first request will store the scatter-gather list. | |
1441 | */ | |
1442 | if (s2->num_sg != 0) { | |
1443 | /* Update "id" with the ID of the first response. */ | |
1444 | *id = s->associated_id; | |
1445 | s = s2; | |
1446 | } | |
1447 | ||
1448 | /* | |
1449 | * We don't need anymore the second request, so recycling | |
1450 | * it now. | |
1451 | */ | |
1452 | if (add_id_to_freelist(rinfo, s->associated_id)) | |
1453 | WARN(1, "%s: can't recycle the second part (id = %ld) of the request\n", | |
1454 | info->gd->disk_name, s->associated_id); | |
1455 | } | |
1456 | ||
1457 | data.s = s; | |
c004a6fe | 1458 | num_sg = s->num_sg; |
0a8704a5 | 1459 | |
bfe11d6d | 1460 | if (bret->operation == BLKIF_OP_READ && info->feature_persistent) { |
c004a6fe | 1461 | for_each_sg(s->sg, sg, num_sg, i) { |
b7649158 | 1462 | BUG_ON(sg->offset + sg->length > PAGE_SIZE); |
c004a6fe JG |
1463 | |
1464 | data.bvec_offset = sg->offset; | |
1465 | data.bvec_data = kmap_atomic(sg_page(sg)); | |
1466 | ||
1467 | gnttab_foreach_grant_in_range(sg_page(sg), | |
1468 | sg->offset, | |
1469 | sg->length, | |
1470 | blkif_copy_from_grant, | |
1471 | &data); | |
1472 | ||
1473 | kunmap_atomic(data.bvec_data); | |
0a8704a5 RPM |
1474 | } |
1475 | } | |
1476 | /* Add the persistent grant into the list of free grants */ | |
c004a6fe | 1477 | for (i = 0; i < num_grant; i++) { |
fbe363c4 RPM |
1478 | if (gnttab_query_foreign_access(s->grants_used[i]->gref)) { |
1479 | /* | |
1480 | * If the grant is still mapped by the backend (the | |
1481 | * backend has chosen to make this grant persistent) | |
1482 | * we add it at the head of the list, so it will be | |
1483 | * reused first. | |
1484 | */ | |
bfe11d6d RPM |
1485 | if (!info->feature_persistent) |
1486 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1487 | s->grants_used[i]->gref); | |
73716df7 BL |
1488 | list_add(&s->grants_used[i]->node, &rinfo->grants); |
1489 | rinfo->persistent_gnts_c++; | |
fbe363c4 RPM |
1490 | } else { |
1491 | /* | |
1492 | * If the grant is not mapped by the backend we end the | |
1493 | * foreign access and add it to the tail of the list, | |
1494 | * so it will not be picked again unless we run out of | |
1495 | * persistent grants. | |
1496 | */ | |
1497 | gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL); | |
1498 | s->grants_used[i]->gref = GRANT_INVALID_REF; | |
73716df7 | 1499 | list_add_tail(&s->grants_used[i]->node, &rinfo->grants); |
fbe363c4 | 1500 | } |
0a8704a5 | 1501 | } |
402b27f9 | 1502 | if (s->req.operation == BLKIF_OP_INDIRECT) { |
c004a6fe | 1503 | for (i = 0; i < INDIRECT_GREFS(num_grant); i++) { |
fbe363c4 | 1504 | if (gnttab_query_foreign_access(s->indirect_grants[i]->gref)) { |
bfe11d6d RPM |
1505 | if (!info->feature_persistent) |
1506 | pr_alert_ratelimited("backed has not unmapped grant: %u\n", | |
1507 | s->indirect_grants[i]->gref); | |
73716df7 BL |
1508 | list_add(&s->indirect_grants[i]->node, &rinfo->grants); |
1509 | rinfo->persistent_gnts_c++; | |
fbe363c4 | 1510 | } else { |
bfe11d6d RPM |
1511 | struct page *indirect_page; |
1512 | ||
fbe363c4 | 1513 | gnttab_end_foreign_access(s->indirect_grants[i]->gref, 0, 0UL); |
bfe11d6d RPM |
1514 | /* |
1515 | * Add the used indirect page back to the list of | |
1516 | * available pages for indirect grefs. | |
1517 | */ | |
7b076750 | 1518 | if (!info->feature_persistent) { |
a7a6df22 | 1519 | indirect_page = s->indirect_grants[i]->page; |
81f35161 | 1520 | list_add(&indirect_page->lru, &rinfo->indirect_pages); |
7b076750 | 1521 | } |
fbe363c4 | 1522 | s->indirect_grants[i]->gref = GRANT_INVALID_REF; |
73716df7 | 1523 | list_add_tail(&s->indirect_grants[i]->node, &rinfo->grants); |
fbe363c4 | 1524 | } |
402b27f9 RPM |
1525 | } |
1526 | } | |
6cc56833 JG |
1527 | |
1528 | return 1; | |
9f27ee59 JF |
1529 | } |
1530 | ||
1531 | static irqreturn_t blkif_interrupt(int irq, void *dev_id) | |
1532 | { | |
1533 | struct request *req; | |
1534 | struct blkif_response *bret; | |
1535 | RING_IDX i, rp; | |
1536 | unsigned long flags; | |
81f35161 BL |
1537 | struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)dev_id; |
1538 | struct blkfront_info *info = rinfo->dev_info; | |
f4829a9b | 1539 | int error; |
9f27ee59 | 1540 | |
11659569 | 1541 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) |
9f27ee59 | 1542 | return IRQ_HANDLED; |
9f27ee59 | 1543 | |
11659569 | 1544 | spin_lock_irqsave(&rinfo->ring_lock, flags); |
9f27ee59 | 1545 | again: |
81f35161 | 1546 | rp = rinfo->ring.sring->rsp_prod; |
9f27ee59 JF |
1547 | rmb(); /* Ensure we see queued responses up to 'rp'. */ |
1548 | ||
81f35161 | 1549 | for (i = rinfo->ring.rsp_cons; i != rp; i++) { |
9f27ee59 | 1550 | unsigned long id; |
9f27ee59 | 1551 | |
81f35161 | 1552 | bret = RING_GET_RESPONSE(&rinfo->ring, i); |
9f27ee59 | 1553 | id = bret->id; |
6878c32e KRW |
1554 | /* |
1555 | * The backend has messed up and given us an id that we would | |
1556 | * never have given to it (we stamp it up to BLK_RING_SIZE - | |
1557 | * look in get_id_from_freelist. | |
1558 | */ | |
86839c56 | 1559 | if (id >= BLK_RING_SIZE(info)) { |
6878c32e KRW |
1560 | WARN(1, "%s: response to %s has incorrect id (%ld)\n", |
1561 | info->gd->disk_name, op_name(bret->operation), id); | |
1562 | /* We can't safely get the 'struct request' as | |
1563 | * the id is busted. */ | |
1564 | continue; | |
1565 | } | |
81f35161 | 1566 | req = rinfo->shadow[id].request; |
9f27ee59 | 1567 | |
6cc56833 JG |
1568 | if (bret->operation != BLKIF_OP_DISCARD) { |
1569 | /* | |
1570 | * We may need to wait for an extra response if the | |
1571 | * I/O request is split in 2 | |
1572 | */ | |
1573 | if (!blkif_completion(&id, rinfo, bret)) | |
1574 | continue; | |
1575 | } | |
9f27ee59 | 1576 | |
81f35161 | 1577 | if (add_id_to_freelist(rinfo, id)) { |
6878c32e KRW |
1578 | WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n", |
1579 | info->gd->disk_name, op_name(bret->operation), id); | |
1580 | continue; | |
1581 | } | |
9f27ee59 | 1582 | |
f4829a9b | 1583 | error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO; |
9f27ee59 | 1584 | switch (bret->operation) { |
ed30bf31 LD |
1585 | case BLKIF_OP_DISCARD: |
1586 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
1587 | struct request_queue *rq = info->rq; | |
6878c32e KRW |
1588 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1589 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1590 | error = -EOPNOTSUPP; |
ed30bf31 | 1591 | info->feature_discard = 0; |
5ea42986 | 1592 | info->feature_secdiscard = 0; |
ed30bf31 | 1593 | queue_flag_clear(QUEUE_FLAG_DISCARD, rq); |
288dab8a | 1594 | queue_flag_clear(QUEUE_FLAG_SECERASE, rq); |
ed30bf31 | 1595 | } |
f4829a9b | 1596 | blk_mq_complete_request(req, error); |
ed30bf31 | 1597 | break; |
edf6ef59 | 1598 | case BLKIF_OP_FLUSH_DISKCACHE: |
9f27ee59 JF |
1599 | case BLKIF_OP_WRITE_BARRIER: |
1600 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
6878c32e KRW |
1601 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
1602 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1603 | error = -EOPNOTSUPP; |
dcb8baec JF |
1604 | } |
1605 | if (unlikely(bret->status == BLKIF_RSP_ERROR && | |
81f35161 | 1606 | rinfo->shadow[id].req.u.rw.nr_segments == 0)) { |
6878c32e KRW |
1607 | printk(KERN_WARNING "blkfront: %s: empty %s op failed\n", |
1608 | info->gd->disk_name, op_name(bret->operation)); | |
f4829a9b | 1609 | error = -EOPNOTSUPP; |
dcb8baec | 1610 | } |
f4829a9b CH |
1611 | if (unlikely(error)) { |
1612 | if (error == -EOPNOTSUPP) | |
1613 | error = 0; | |
a418090a | 1614 | info->feature_fua = 0; |
4913efe4 TH |
1615 | info->feature_flush = 0; |
1616 | xlvbd_flush(info); | |
9f27ee59 JF |
1617 | } |
1618 | /* fall through */ | |
1619 | case BLKIF_OP_READ: | |
1620 | case BLKIF_OP_WRITE: | |
1621 | if (unlikely(bret->status != BLKIF_RSP_OKAY)) | |
1622 | dev_dbg(&info->xbdev->dev, "Bad return from blkdev data " | |
1623 | "request: %x\n", bret->status); | |
1624 | ||
f4829a9b | 1625 | blk_mq_complete_request(req, error); |
9f27ee59 JF |
1626 | break; |
1627 | default: | |
1628 | BUG(); | |
1629 | } | |
1630 | } | |
1631 | ||
81f35161 | 1632 | rinfo->ring.rsp_cons = i; |
9f27ee59 | 1633 | |
81f35161 | 1634 | if (i != rinfo->ring.req_prod_pvt) { |
9f27ee59 | 1635 | int more_to_do; |
81f35161 | 1636 | RING_FINAL_CHECK_FOR_RESPONSES(&rinfo->ring, more_to_do); |
9f27ee59 JF |
1637 | if (more_to_do) |
1638 | goto again; | |
1639 | } else | |
81f35161 | 1640 | rinfo->ring.sring->rsp_event = i + 1; |
9f27ee59 | 1641 | |
11659569 | 1642 | kick_pending_request_queues_locked(rinfo); |
9f27ee59 | 1643 | |
11659569 | 1644 | spin_unlock_irqrestore(&rinfo->ring_lock, flags); |
9f27ee59 JF |
1645 | |
1646 | return IRQ_HANDLED; | |
1647 | } | |
1648 | ||
1649 | ||
1650 | static int setup_blkring(struct xenbus_device *dev, | |
81f35161 | 1651 | struct blkfront_ring_info *rinfo) |
9f27ee59 JF |
1652 | { |
1653 | struct blkif_sring *sring; | |
86839c56 | 1654 | int err, i; |
81f35161 | 1655 | struct blkfront_info *info = rinfo->dev_info; |
c004a6fe | 1656 | unsigned long ring_size = info->nr_ring_pages * XEN_PAGE_SIZE; |
9cce2914 | 1657 | grant_ref_t gref[XENBUS_MAX_RING_GRANTS]; |
9f27ee59 | 1658 | |
86839c56 | 1659 | for (i = 0; i < info->nr_ring_pages; i++) |
81f35161 | 1660 | rinfo->ring_ref[i] = GRANT_INVALID_REF; |
9f27ee59 | 1661 | |
86839c56 BL |
1662 | sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH, |
1663 | get_order(ring_size)); | |
9f27ee59 JF |
1664 | if (!sring) { |
1665 | xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); | |
1666 | return -ENOMEM; | |
1667 | } | |
1668 | SHARED_RING_INIT(sring); | |
81f35161 | 1669 | FRONT_RING_INIT(&rinfo->ring, sring, ring_size); |
9e973e64 | 1670 | |
81f35161 | 1671 | err = xenbus_grant_ring(dev, rinfo->ring.sring, info->nr_ring_pages, gref); |
9f27ee59 | 1672 | if (err < 0) { |
86839c56 | 1673 | free_pages((unsigned long)sring, get_order(ring_size)); |
81f35161 | 1674 | rinfo->ring.sring = NULL; |
9f27ee59 JF |
1675 | goto fail; |
1676 | } | |
86839c56 | 1677 | for (i = 0; i < info->nr_ring_pages; i++) |
81f35161 | 1678 | rinfo->ring_ref[i] = gref[i]; |
9f27ee59 | 1679 | |
81f35161 | 1680 | err = xenbus_alloc_evtchn(dev, &rinfo->evtchn); |
9f27ee59 JF |
1681 | if (err) |
1682 | goto fail; | |
1683 | ||
81f35161 BL |
1684 | err = bind_evtchn_to_irqhandler(rinfo->evtchn, blkif_interrupt, 0, |
1685 | "blkif", rinfo); | |
9f27ee59 JF |
1686 | if (err <= 0) { |
1687 | xenbus_dev_fatal(dev, err, | |
1688 | "bind_evtchn_to_irqhandler failed"); | |
1689 | goto fail; | |
1690 | } | |
81f35161 | 1691 | rinfo->irq = err; |
9f27ee59 JF |
1692 | |
1693 | return 0; | |
1694 | fail: | |
1695 | blkif_free(info, 0); | |
1696 | return err; | |
1697 | } | |
1698 | ||
28d949bc BL |
1699 | /* |
1700 | * Write out per-ring/queue nodes including ring-ref and event-channel, and each | |
1701 | * ring buffer may have multi pages depending on ->nr_ring_pages. | |
1702 | */ | |
1703 | static int write_per_ring_nodes(struct xenbus_transaction xbt, | |
1704 | struct blkfront_ring_info *rinfo, const char *dir) | |
1705 | { | |
1706 | int err; | |
1707 | unsigned int i; | |
1708 | const char *message = NULL; | |
1709 | struct blkfront_info *info = rinfo->dev_info; | |
1710 | ||
1711 | if (info->nr_ring_pages == 1) { | |
1712 | err = xenbus_printf(xbt, dir, "ring-ref", "%u", rinfo->ring_ref[0]); | |
1713 | if (err) { | |
1714 | message = "writing ring-ref"; | |
1715 | goto abort_transaction; | |
1716 | } | |
1717 | } else { | |
1718 | for (i = 0; i < info->nr_ring_pages; i++) { | |
1719 | char ring_ref_name[RINGREF_NAME_LEN]; | |
1720 | ||
1721 | snprintf(ring_ref_name, RINGREF_NAME_LEN, "ring-ref%u", i); | |
1722 | err = xenbus_printf(xbt, dir, ring_ref_name, | |
1723 | "%u", rinfo->ring_ref[i]); | |
1724 | if (err) { | |
1725 | message = "writing ring-ref"; | |
1726 | goto abort_transaction; | |
1727 | } | |
1728 | } | |
1729 | } | |
1730 | ||
1731 | err = xenbus_printf(xbt, dir, "event-channel", "%u", rinfo->evtchn); | |
1732 | if (err) { | |
1733 | message = "writing event-channel"; | |
1734 | goto abort_transaction; | |
1735 | } | |
1736 | ||
1737 | return 0; | |
1738 | ||
1739 | abort_transaction: | |
1740 | xenbus_transaction_end(xbt, 1); | |
1741 | if (message) | |
1742 | xenbus_dev_fatal(info->xbdev, err, "%s", message); | |
1743 | ||
1744 | return err; | |
1745 | } | |
9f27ee59 JF |
1746 | |
1747 | /* Common code used when first setting up, and when resuming. */ | |
203fd61f | 1748 | static int talk_to_blkback(struct xenbus_device *dev, |
9f27ee59 JF |
1749 | struct blkfront_info *info) |
1750 | { | |
1751 | const char *message = NULL; | |
1752 | struct xenbus_transaction xbt; | |
28d949bc BL |
1753 | int err; |
1754 | unsigned int i, max_page_order = 0; | |
86839c56 BL |
1755 | unsigned int ring_page_order = 0; |
1756 | ||
1757 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1758 | "max-ring-page-order", "%u", &max_page_order); | |
1759 | if (err != 1) | |
1760 | info->nr_ring_pages = 1; | |
1761 | else { | |
1762 | ring_page_order = min(xen_blkif_max_ring_order, max_page_order); | |
1763 | info->nr_ring_pages = 1 << ring_page_order; | |
1764 | } | |
9f27ee59 | 1765 | |
3df0e505 | 1766 | for (i = 0; i < info->nr_rings; i++) { |
28d949bc BL |
1767 | struct blkfront_ring_info *rinfo = &info->rinfo[i]; |
1768 | ||
3df0e505 BL |
1769 | /* Create shared ring, alloc event channel. */ |
1770 | err = setup_blkring(dev, rinfo); | |
1771 | if (err) | |
1772 | goto destroy_blkring; | |
1773 | } | |
9f27ee59 JF |
1774 | |
1775 | again: | |
1776 | err = xenbus_transaction_start(&xbt); | |
1777 | if (err) { | |
1778 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
1779 | goto destroy_blkring; | |
1780 | } | |
1781 | ||
28d949bc BL |
1782 | if (info->nr_ring_pages > 1) { |
1783 | err = xenbus_printf(xbt, dev->nodename, "ring-page-order", "%u", | |
1784 | ring_page_order); | |
1785 | if (err) { | |
1786 | message = "writing ring-page-order"; | |
1787 | goto abort_transaction; | |
1788 | } | |
1789 | } | |
3df0e505 | 1790 | |
28d949bc BL |
1791 | /* We already got the number of queues/rings in _probe */ |
1792 | if (info->nr_rings == 1) { | |
1793 | err = write_per_ring_nodes(xbt, &info->rinfo[0], dev->nodename); | |
1794 | if (err) | |
1795 | goto destroy_blkring; | |
1796 | } else { | |
1797 | char *path; | |
1798 | size_t pathsize; | |
3df0e505 | 1799 | |
28d949bc BL |
1800 | err = xenbus_printf(xbt, dev->nodename, "multi-queue-num-queues", "%u", |
1801 | info->nr_rings); | |
3df0e505 | 1802 | if (err) { |
28d949bc | 1803 | message = "writing multi-queue-num-queues"; |
3df0e505 BL |
1804 | goto abort_transaction; |
1805 | } | |
28d949bc BL |
1806 | |
1807 | pathsize = strlen(dev->nodename) + QUEUE_NAME_LEN; | |
1808 | path = kmalloc(pathsize, GFP_KERNEL); | |
1809 | if (!path) { | |
1810 | err = -ENOMEM; | |
1811 | message = "ENOMEM while writing ring references"; | |
1812 | goto abort_transaction; | |
1813 | } | |
1814 | ||
1815 | for (i = 0; i < info->nr_rings; i++) { | |
1816 | memset(path, 0, pathsize); | |
1817 | snprintf(path, pathsize, "%s/queue-%u", dev->nodename, i); | |
1818 | err = write_per_ring_nodes(xbt, &info->rinfo[i], path); | |
1819 | if (err) { | |
1820 | kfree(path); | |
1821 | goto destroy_blkring; | |
1822 | } | |
1823 | } | |
1824 | kfree(path); | |
9f27ee59 | 1825 | } |
3e334239 MA |
1826 | err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", |
1827 | XEN_IO_PROTO_ABI_NATIVE); | |
1828 | if (err) { | |
1829 | message = "writing protocol"; | |
1830 | goto abort_transaction; | |
1831 | } | |
0a8704a5 | 1832 | err = xenbus_printf(xbt, dev->nodename, |
cb5bd4d1 | 1833 | "feature-persistent", "%u", 1); |
0a8704a5 RPM |
1834 | if (err) |
1835 | dev_warn(&dev->dev, | |
1836 | "writing persistent grants feature to xenbus"); | |
9f27ee59 JF |
1837 | |
1838 | err = xenbus_transaction_end(xbt, 0); | |
1839 | if (err) { | |
1840 | if (err == -EAGAIN) | |
1841 | goto again; | |
1842 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
1843 | goto destroy_blkring; | |
1844 | } | |
1845 | ||
3df0e505 BL |
1846 | for (i = 0; i < info->nr_rings; i++) { |
1847 | unsigned int j; | |
28d949bc | 1848 | struct blkfront_ring_info *rinfo = &info->rinfo[i]; |
3df0e505 BL |
1849 | |
1850 | for (j = 0; j < BLK_RING_SIZE(info); j++) | |
1851 | rinfo->shadow[j].req.u.rw.id = j + 1; | |
1852 | rinfo->shadow[BLK_RING_SIZE(info)-1].req.u.rw.id = 0x0fffffff; | |
1853 | } | |
9f27ee59 JF |
1854 | xenbus_switch_state(dev, XenbusStateInitialised); |
1855 | ||
1856 | return 0; | |
1857 | ||
1858 | abort_transaction: | |
1859 | xenbus_transaction_end(xbt, 1); | |
1860 | if (message) | |
1861 | xenbus_dev_fatal(dev, err, "%s", message); | |
1862 | destroy_blkring: | |
1863 | blkif_free(info, 0); | |
3df0e505 | 1864 | |
c31ecf6c KRW |
1865 | kfree(info); |
1866 | dev_set_drvdata(&dev->dev, NULL); | |
1867 | ||
9f27ee59 JF |
1868 | return err; |
1869 | } | |
1870 | ||
3db70a85 BL |
1871 | static int negotiate_mq(struct blkfront_info *info) |
1872 | { | |
1873 | unsigned int backend_max_queues = 0; | |
1874 | int err; | |
1875 | unsigned int i; | |
1876 | ||
1877 | BUG_ON(info->nr_rings); | |
1878 | ||
1879 | /* Check if backend supports multiple queues. */ | |
1880 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1881 | "multi-queue-max-queues", "%u", &backend_max_queues); | |
1882 | if (err < 0) | |
1883 | backend_max_queues = 1; | |
1884 | ||
1885 | info->nr_rings = min(backend_max_queues, xen_blkif_max_queues); | |
1886 | /* We need at least one ring. */ | |
1887 | if (!info->nr_rings) | |
1888 | info->nr_rings = 1; | |
1889 | ||
1890 | info->rinfo = kzalloc(sizeof(struct blkfront_ring_info) * info->nr_rings, GFP_KERNEL); | |
1891 | if (!info->rinfo) { | |
1892 | xenbus_dev_fatal(info->xbdev, -ENOMEM, "allocating ring_info structure"); | |
1893 | return -ENOMEM; | |
1894 | } | |
1895 | ||
1896 | for (i = 0; i < info->nr_rings; i++) { | |
1897 | struct blkfront_ring_info *rinfo; | |
1898 | ||
1899 | rinfo = &info->rinfo[i]; | |
1900 | INIT_LIST_HEAD(&rinfo->indirect_pages); | |
1901 | INIT_LIST_HEAD(&rinfo->grants); | |
1902 | rinfo->dev_info = info; | |
1903 | INIT_WORK(&rinfo->work, blkif_restart_queue); | |
1904 | spin_lock_init(&rinfo->ring_lock); | |
1905 | } | |
1906 | return 0; | |
1907 | } | |
9f27ee59 JF |
1908 | /** |
1909 | * Entry point to this code when a new device is created. Allocate the basic | |
1910 | * structures and the ring buffer for communication with the backend, and | |
1911 | * inform the backend of the appropriate details for those. Switch to | |
1912 | * Initialised state. | |
1913 | */ | |
1914 | static int blkfront_probe(struct xenbus_device *dev, | |
1915 | const struct xenbus_device_id *id) | |
1916 | { | |
86839c56 | 1917 | int err, vdevice; |
9f27ee59 JF |
1918 | struct blkfront_info *info; |
1919 | ||
1920 | /* FIXME: Use dynamic device id if this is not set. */ | |
1921 | err = xenbus_scanf(XBT_NIL, dev->nodename, | |
1922 | "virtual-device", "%i", &vdevice); | |
1923 | if (err != 1) { | |
9246b5f0 CL |
1924 | /* go looking in the extended area instead */ |
1925 | err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext", | |
1926 | "%i", &vdevice); | |
1927 | if (err != 1) { | |
1928 | xenbus_dev_fatal(dev, err, "reading virtual-device"); | |
1929 | return err; | |
1930 | } | |
9f27ee59 JF |
1931 | } |
1932 | ||
b98a409b SS |
1933 | if (xen_hvm_domain()) { |
1934 | char *type; | |
1935 | int len; | |
1936 | /* no unplug has been done: do not hook devices != xen vbds */ | |
51c71a3b | 1937 | if (xen_has_pv_and_legacy_disk_devices()) { |
b98a409b SS |
1938 | int major; |
1939 | ||
1940 | if (!VDEV_IS_EXTENDED(vdevice)) | |
1941 | major = BLKIF_MAJOR(vdevice); | |
1942 | else | |
1943 | major = XENVBD_MAJOR; | |
1944 | ||
1945 | if (major != XENVBD_MAJOR) { | |
1946 | printk(KERN_INFO | |
1947 | "%s: HVM does not support vbd %d as xen block device\n", | |
02f1f217 | 1948 | __func__, vdevice); |
b98a409b SS |
1949 | return -ENODEV; |
1950 | } | |
1951 | } | |
1952 | /* do not create a PV cdrom device if we are an HVM guest */ | |
1953 | type = xenbus_read(XBT_NIL, dev->nodename, "device-type", &len); | |
1954 | if (IS_ERR(type)) | |
1955 | return -ENODEV; | |
1956 | if (strncmp(type, "cdrom", 5) == 0) { | |
1957 | kfree(type); | |
c1c5413a SS |
1958 | return -ENODEV; |
1959 | } | |
b98a409b | 1960 | kfree(type); |
c1c5413a | 1961 | } |
9f27ee59 JF |
1962 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
1963 | if (!info) { | |
1964 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
1965 | return -ENOMEM; | |
1966 | } | |
1967 | ||
28d949bc | 1968 | info->xbdev = dev; |
3db70a85 BL |
1969 | err = negotiate_mq(info); |
1970 | if (err) { | |
3df0e505 | 1971 | kfree(info); |
3db70a85 | 1972 | return err; |
3df0e505 | 1973 | } |
81f35161 | 1974 | |
b70f5fa0 | 1975 | mutex_init(&info->mutex); |
9f27ee59 JF |
1976 | info->vdevice = vdevice; |
1977 | info->connected = BLKIF_STATE_DISCONNECTED; | |
9f27ee59 | 1978 | |
9f27ee59 JF |
1979 | /* Front end dir is a number, which is used as the id. */ |
1980 | info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); | |
a1b4b12b | 1981 | dev_set_drvdata(&dev->dev, info); |
9f27ee59 | 1982 | |
9f27ee59 JF |
1983 | return 0; |
1984 | } | |
1985 | ||
4246a0b6 | 1986 | static void split_bio_end(struct bio *bio) |
402b27f9 RPM |
1987 | { |
1988 | struct split_bio *split_bio = bio->bi_private; | |
1989 | ||
402b27f9 RPM |
1990 | if (atomic_dec_and_test(&split_bio->pending)) { |
1991 | split_bio->bio->bi_phys_segments = 0; | |
4246a0b6 CH |
1992 | split_bio->bio->bi_error = bio->bi_error; |
1993 | bio_endio(split_bio->bio); | |
402b27f9 RPM |
1994 | kfree(split_bio); |
1995 | } | |
1996 | bio_put(bio); | |
1997 | } | |
9f27ee59 JF |
1998 | |
1999 | static int blkif_recover(struct blkfront_info *info) | |
2000 | { | |
3df0e505 | 2001 | unsigned int i, r_index; |
402b27f9 | 2002 | struct request *req, *n; |
402b27f9 RPM |
2003 | int rc; |
2004 | struct bio *bio, *cloned_bio; | |
402b27f9 RPM |
2005 | unsigned int segs, offset; |
2006 | int pending, size; | |
2007 | struct split_bio *split_bio; | |
402b27f9 | 2008 | |
3df0e505 | 2009 | blkfront_gather_backend_features(info); |
402b27f9 RPM |
2010 | segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST; |
2011 | blk_queue_max_segments(info->rq, segs); | |
9f27ee59 | 2012 | |
3df0e505 | 2013 | for (r_index = 0; r_index < info->nr_rings; r_index++) { |
7b427a59 | 2014 | struct blkfront_ring_info *rinfo = &info->rinfo[r_index]; |
3df0e505 BL |
2015 | |
2016 | rc = blkfront_setup_indirect(rinfo); | |
7b427a59 | 2017 | if (rc) |
3df0e505 | 2018 | return rc; |
3df0e505 | 2019 | } |
9f27ee59 JF |
2020 | xenbus_switch_state(info->xbdev, XenbusStateConnected); |
2021 | ||
9f27ee59 JF |
2022 | /* Now safe for us to use the shared ring */ |
2023 | info->connected = BLKIF_STATE_CONNECTED; | |
2024 | ||
3df0e505 BL |
2025 | for (r_index = 0; r_index < info->nr_rings; r_index++) { |
2026 | struct blkfront_ring_info *rinfo; | |
2027 | ||
2028 | rinfo = &info->rinfo[r_index]; | |
2029 | /* Kick any other new requests queued since we resumed */ | |
2030 | kick_pending_request_queues(rinfo); | |
2031 | } | |
9f27ee59 | 2032 | |
7b427a59 | 2033 | list_for_each_entry_safe(req, n, &info->requests, queuelist) { |
402b27f9 RPM |
2034 | /* Requeue pending requests (flush or discard) */ |
2035 | list_del_init(&req->queuelist); | |
2036 | BUG_ON(req->nr_phys_segments > segs); | |
907c3eb1 | 2037 | blk_mq_requeue_request(req); |
402b27f9 | 2038 | } |
907c3eb1 | 2039 | blk_mq_kick_requeue_list(info->rq); |
9f27ee59 | 2040 | |
7b427a59 | 2041 | while ((bio = bio_list_pop(&info->bio_list)) != NULL) { |
402b27f9 RPM |
2042 | /* Traverse the list of pending bios and re-queue them */ |
2043 | if (bio_segments(bio) > segs) { | |
2044 | /* | |
2045 | * This bio has more segments than what we can | |
2046 | * handle, we have to split it. | |
2047 | */ | |
2048 | pending = (bio_segments(bio) + segs - 1) / segs; | |
2049 | split_bio = kzalloc(sizeof(*split_bio), GFP_NOIO); | |
2050 | BUG_ON(split_bio == NULL); | |
2051 | atomic_set(&split_bio->pending, pending); | |
2052 | split_bio->bio = bio; | |
2053 | for (i = 0; i < pending; i++) { | |
c004a6fe JG |
2054 | offset = (i * segs * XEN_PAGE_SIZE) >> 9; |
2055 | size = min((unsigned int)(segs * XEN_PAGE_SIZE) >> 9, | |
4f024f37 | 2056 | (unsigned int)bio_sectors(bio) - offset); |
402b27f9 RPM |
2057 | cloned_bio = bio_clone(bio, GFP_NOIO); |
2058 | BUG_ON(cloned_bio == NULL); | |
6678d83f | 2059 | bio_trim(cloned_bio, offset, size); |
402b27f9 RPM |
2060 | cloned_bio->bi_private = split_bio; |
2061 | cloned_bio->bi_end_io = split_bio_end; | |
4e49ea4a | 2062 | submit_bio(cloned_bio); |
402b27f9 RPM |
2063 | } |
2064 | /* | |
2065 | * Now we have to wait for all those smaller bios to | |
2066 | * end, so we can also end the "parent" bio. | |
2067 | */ | |
2068 | continue; | |
2069 | } | |
2070 | /* We don't need to split this bio */ | |
4e49ea4a | 2071 | submit_bio(bio); |
402b27f9 RPM |
2072 | } |
2073 | ||
9f27ee59 JF |
2074 | return 0; |
2075 | } | |
2076 | ||
2077 | /** | |
2078 | * We are reconnecting to the backend, due to a suspend/resume, or a backend | |
2079 | * driver restart. We tear down our blkif structure and recreate it, but | |
2080 | * leave the device-layer structures intact so that this is transparent to the | |
2081 | * rest of the kernel. | |
2082 | */ | |
2083 | static int blkfront_resume(struct xenbus_device *dev) | |
2084 | { | |
a1b4b12b | 2085 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
3db70a85 | 2086 | int err = 0; |
7b427a59 | 2087 | unsigned int i, j; |
9f27ee59 JF |
2088 | |
2089 | dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename); | |
2090 | ||
7b427a59 BL |
2091 | bio_list_init(&info->bio_list); |
2092 | INIT_LIST_HEAD(&info->requests); | |
2093 | for (i = 0; i < info->nr_rings; i++) { | |
2094 | struct blkfront_ring_info *rinfo = &info->rinfo[i]; | |
2095 | struct bio_list merge_bio; | |
2096 | struct blk_shadow *shadow = rinfo->shadow; | |
2097 | ||
2098 | for (j = 0; j < BLK_RING_SIZE(info); j++) { | |
2099 | /* Not in use? */ | |
2100 | if (!shadow[j].request) | |
2101 | continue; | |
2102 | ||
2103 | /* | |
2104 | * Get the bios in the request so we can re-queue them. | |
2105 | */ | |
d05d7f40 LT |
2106 | if (req_op(shadow[i].request) == REQ_OP_FLUSH || |
2107 | req_op(shadow[i].request) == REQ_OP_DISCARD || | |
3fc9d690 LT |
2108 | req_op(shadow[i].request) == REQ_OP_SECURE_ERASE || |
2109 | shadow[j].request->cmd_flags & REQ_FUA) { | |
7b427a59 BL |
2110 | /* |
2111 | * Flush operations don't contain bios, so | |
2112 | * we need to requeue the whole request | |
3fc9d690 LT |
2113 | * |
2114 | * XXX: but this doesn't make any sense for a | |
2115 | * write with the FUA flag set.. | |
7b427a59 BL |
2116 | */ |
2117 | list_add(&shadow[j].request->queuelist, &info->requests); | |
2118 | continue; | |
2119 | } | |
2120 | merge_bio.head = shadow[j].request->bio; | |
2121 | merge_bio.tail = shadow[j].request->biotail; | |
2122 | bio_list_merge(&info->bio_list, &merge_bio); | |
2123 | shadow[j].request->bio = NULL; | |
2124 | blk_mq_end_request(shadow[j].request, 0); | |
2125 | } | |
2126 | } | |
2127 | ||
9f27ee59 JF |
2128 | blkif_free(info, info->connected == BLKIF_STATE_CONNECTED); |
2129 | ||
3db70a85 BL |
2130 | err = negotiate_mq(info); |
2131 | if (err) | |
2132 | return err; | |
2133 | ||
203fd61f | 2134 | err = talk_to_blkback(dev, info); |
2a6f71ad BL |
2135 | if (!err) |
2136 | blk_mq_update_nr_hw_queues(&info->tag_set, info->nr_rings); | |
402b27f9 RPM |
2137 | |
2138 | /* | |
2139 | * We have to wait for the backend to switch to | |
2140 | * connected state, since we want to read which | |
2141 | * features it supports. | |
2142 | */ | |
9f27ee59 JF |
2143 | |
2144 | return err; | |
2145 | } | |
2146 | ||
6f03a7ff | 2147 | static void blkfront_closing(struct blkfront_info *info) |
b70f5fa0 DS |
2148 | { |
2149 | struct xenbus_device *xbdev = info->xbdev; | |
2150 | struct block_device *bdev = NULL; | |
2151 | ||
2152 | mutex_lock(&info->mutex); | |
2153 | ||
2154 | if (xbdev->state == XenbusStateClosing) { | |
2155 | mutex_unlock(&info->mutex); | |
2156 | return; | |
2157 | } | |
2158 | ||
2159 | if (info->gd) | |
2160 | bdev = bdget_disk(info->gd, 0); | |
2161 | ||
2162 | mutex_unlock(&info->mutex); | |
2163 | ||
2164 | if (!bdev) { | |
2165 | xenbus_frontend_closed(xbdev); | |
2166 | return; | |
2167 | } | |
2168 | ||
2169 | mutex_lock(&bdev->bd_mutex); | |
2170 | ||
7b32d104 | 2171 | if (bdev->bd_openers) { |
b70f5fa0 DS |
2172 | xenbus_dev_error(xbdev, -EBUSY, |
2173 | "Device in use; refusing to close"); | |
2174 | xenbus_switch_state(xbdev, XenbusStateClosing); | |
2175 | } else { | |
2176 | xlvbd_release_gendisk(info); | |
2177 | xenbus_frontend_closed(xbdev); | |
2178 | } | |
2179 | ||
2180 | mutex_unlock(&bdev->bd_mutex); | |
2181 | bdput(bdev); | |
2182 | } | |
9f27ee59 | 2183 | |
ed30bf31 LD |
2184 | static void blkfront_setup_discard(struct blkfront_info *info) |
2185 | { | |
2186 | int err; | |
ed30bf31 LD |
2187 | unsigned int discard_granularity; |
2188 | unsigned int discard_alignment; | |
5ea42986 | 2189 | unsigned int discard_secure; |
ed30bf31 | 2190 | |
1c8cad6c OH |
2191 | info->feature_discard = 1; |
2192 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
2193 | "discard-granularity", "%u", &discard_granularity, | |
2194 | "discard-alignment", "%u", &discard_alignment, | |
2195 | NULL); | |
2196 | if (!err) { | |
2197 | info->discard_granularity = discard_granularity; | |
2198 | info->discard_alignment = discard_alignment; | |
2199 | } | |
ff595325 JB |
2200 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, |
2201 | "discard-secure", "%u", &discard_secure); | |
2202 | if (err > 0) | |
1c8cad6c | 2203 | info->feature_secdiscard = !!discard_secure; |
ed30bf31 LD |
2204 | } |
2205 | ||
81f35161 | 2206 | static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo) |
402b27f9 | 2207 | { |
c004a6fe | 2208 | unsigned int psegs, grants; |
402b27f9 | 2209 | int err, i; |
81f35161 | 2210 | struct blkfront_info *info = rinfo->dev_info; |
402b27f9 | 2211 | |
6cc56833 JG |
2212 | if (info->max_indirect_segments == 0) { |
2213 | if (!HAS_EXTRA_REQ) | |
2214 | grants = BLKIF_MAX_SEGMENTS_PER_REQUEST; | |
2215 | else { | |
2216 | /* | |
2217 | * When an extra req is required, the maximum | |
2218 | * grants supported is related to the size of the | |
2219 | * Linux block segment. | |
2220 | */ | |
2221 | grants = GRANTS_PER_PSEG; | |
2222 | } | |
2223 | } | |
d50babbe | 2224 | else |
c004a6fe JG |
2225 | grants = info->max_indirect_segments; |
2226 | psegs = grants / GRANTS_PER_PSEG; | |
402b27f9 | 2227 | |
81f35161 | 2228 | err = fill_grant_buffer(rinfo, |
c004a6fe | 2229 | (grants + INDIRECT_GREFS(grants)) * BLK_RING_SIZE(info)); |
402b27f9 RPM |
2230 | if (err) |
2231 | goto out_of_memory; | |
2232 | ||
bfe11d6d RPM |
2233 | if (!info->feature_persistent && info->max_indirect_segments) { |
2234 | /* | |
2235 | * We are using indirect descriptors but not persistent | |
2236 | * grants, we need to allocate a set of pages that can be | |
2237 | * used for mapping indirect grefs | |
2238 | */ | |
c004a6fe | 2239 | int num = INDIRECT_GREFS(grants) * BLK_RING_SIZE(info); |
bfe11d6d | 2240 | |
81f35161 | 2241 | BUG_ON(!list_empty(&rinfo->indirect_pages)); |
bfe11d6d RPM |
2242 | for (i = 0; i < num; i++) { |
2243 | struct page *indirect_page = alloc_page(GFP_NOIO); | |
2244 | if (!indirect_page) | |
2245 | goto out_of_memory; | |
81f35161 | 2246 | list_add(&indirect_page->lru, &rinfo->indirect_pages); |
bfe11d6d RPM |
2247 | } |
2248 | } | |
2249 | ||
86839c56 | 2250 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
81f35161 BL |
2251 | rinfo->shadow[i].grants_used = kzalloc( |
2252 | sizeof(rinfo->shadow[i].grants_used[0]) * grants, | |
402b27f9 | 2253 | GFP_NOIO); |
81f35161 | 2254 | rinfo->shadow[i].sg = kzalloc(sizeof(rinfo->shadow[i].sg[0]) * psegs, GFP_NOIO); |
402b27f9 | 2255 | if (info->max_indirect_segments) |
81f35161 BL |
2256 | rinfo->shadow[i].indirect_grants = kzalloc( |
2257 | sizeof(rinfo->shadow[i].indirect_grants[0]) * | |
c004a6fe | 2258 | INDIRECT_GREFS(grants), |
402b27f9 | 2259 | GFP_NOIO); |
81f35161 BL |
2260 | if ((rinfo->shadow[i].grants_used == NULL) || |
2261 | (rinfo->shadow[i].sg == NULL) || | |
402b27f9 | 2262 | (info->max_indirect_segments && |
81f35161 | 2263 | (rinfo->shadow[i].indirect_grants == NULL))) |
402b27f9 | 2264 | goto out_of_memory; |
81f35161 | 2265 | sg_init_table(rinfo->shadow[i].sg, psegs); |
402b27f9 RPM |
2266 | } |
2267 | ||
2268 | ||
2269 | return 0; | |
2270 | ||
2271 | out_of_memory: | |
86839c56 | 2272 | for (i = 0; i < BLK_RING_SIZE(info); i++) { |
81f35161 BL |
2273 | kfree(rinfo->shadow[i].grants_used); |
2274 | rinfo->shadow[i].grants_used = NULL; | |
2275 | kfree(rinfo->shadow[i].sg); | |
2276 | rinfo->shadow[i].sg = NULL; | |
2277 | kfree(rinfo->shadow[i].indirect_grants); | |
2278 | rinfo->shadow[i].indirect_grants = NULL; | |
402b27f9 | 2279 | } |
81f35161 | 2280 | if (!list_empty(&rinfo->indirect_pages)) { |
bfe11d6d | 2281 | struct page *indirect_page, *n; |
81f35161 | 2282 | list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) { |
bfe11d6d RPM |
2283 | list_del(&indirect_page->lru); |
2284 | __free_page(indirect_page); | |
2285 | } | |
2286 | } | |
402b27f9 RPM |
2287 | return -ENOMEM; |
2288 | } | |
2289 | ||
d50babbe BL |
2290 | /* |
2291 | * Gather all backend feature-* | |
2292 | */ | |
3df0e505 | 2293 | static void blkfront_gather_backend_features(struct blkfront_info *info) |
d50babbe BL |
2294 | { |
2295 | int err; | |
2296 | int barrier, flush, discard, persistent; | |
2297 | unsigned int indirect_segments; | |
2298 | ||
2299 | info->feature_flush = 0; | |
a418090a | 2300 | info->feature_fua = 0; |
d50babbe | 2301 | |
ff595325 JB |
2302 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, |
2303 | "feature-barrier", "%d", &barrier); | |
d50babbe BL |
2304 | |
2305 | /* | |
2306 | * If there's no "feature-barrier" defined, then it means | |
2307 | * we're dealing with a very old backend which writes | |
2308 | * synchronously; nothing to do. | |
2309 | * | |
2310 | * If there are barriers, then we use flush. | |
2311 | */ | |
08fd8c17 | 2312 | if (err > 0 && barrier) { |
a418090a MC |
2313 | info->feature_flush = 1; |
2314 | info->feature_fua = 1; | |
2315 | } | |
2316 | ||
d50babbe BL |
2317 | /* |
2318 | * And if there is "feature-flush-cache" use that above | |
2319 | * barriers. | |
2320 | */ | |
ff595325 JB |
2321 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, |
2322 | "feature-flush-cache", "%d", &flush); | |
d50babbe | 2323 | |
08fd8c17 | 2324 | if (err > 0 && flush) { |
a418090a MC |
2325 | info->feature_flush = 1; |
2326 | info->feature_fua = 0; | |
2327 | } | |
d50babbe | 2328 | |
ff595325 JB |
2329 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, |
2330 | "feature-discard", "%d", &discard); | |
d50babbe | 2331 | |
ff595325 | 2332 | if (err > 0 && discard) |
d50babbe BL |
2333 | blkfront_setup_discard(info); |
2334 | ||
ff595325 JB |
2335 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, |
2336 | "feature-persistent", "%d", &persistent); | |
2337 | if (err <= 0) | |
d50babbe BL |
2338 | info->feature_persistent = 0; |
2339 | else | |
2340 | info->feature_persistent = persistent; | |
2341 | ||
ff595325 JB |
2342 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, |
2343 | "feature-max-indirect-segments", "%u", | |
2344 | &indirect_segments); | |
2345 | if (err <= 0) | |
d50babbe BL |
2346 | info->max_indirect_segments = 0; |
2347 | else | |
2348 | info->max_indirect_segments = min(indirect_segments, | |
2349 | xen_blkif_max_segments); | |
d50babbe BL |
2350 | } |
2351 | ||
9f27ee59 JF |
2352 | /* |
2353 | * Invoked when the backend is finally 'ready' (and has told produced | |
2354 | * the details about the physical device - #sectors, size, etc). | |
2355 | */ | |
2356 | static void blkfront_connect(struct blkfront_info *info) | |
2357 | { | |
2358 | unsigned long long sectors; | |
2359 | unsigned long sector_size; | |
7c4d7d71 | 2360 | unsigned int physical_sector_size; |
9f27ee59 | 2361 | unsigned int binfo; |
3df0e505 | 2362 | int err, i; |
9f27ee59 | 2363 | |
1fa73be6 S |
2364 | switch (info->connected) { |
2365 | case BLKIF_STATE_CONNECTED: | |
2366 | /* | |
2367 | * Potentially, the back-end may be signalling | |
2368 | * a capacity change; update the capacity. | |
2369 | */ | |
2370 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
2371 | "sectors", "%Lu", §ors); | |
2372 | if (XENBUS_EXIST_ERR(err)) | |
2373 | return; | |
2374 | printk(KERN_INFO "Setting capacity to %Lu\n", | |
2375 | sectors); | |
2376 | set_capacity(info->gd, sectors); | |
2def141e | 2377 | revalidate_disk(info->gd); |
1fa73be6 | 2378 | |
402b27f9 | 2379 | return; |
1fa73be6 | 2380 | case BLKIF_STATE_SUSPENDED: |
402b27f9 RPM |
2381 | /* |
2382 | * If we are recovering from suspension, we need to wait | |
2383 | * for the backend to announce it's features before | |
2384 | * reconnecting, at least we need to know if the backend | |
2385 | * supports indirect descriptors, and how many. | |
2386 | */ | |
2387 | blkif_recover(info); | |
9f27ee59 JF |
2388 | return; |
2389 | ||
b4dddb49 JF |
2390 | default: |
2391 | break; | |
1fa73be6 | 2392 | } |
9f27ee59 JF |
2393 | |
2394 | dev_dbg(&info->xbdev->dev, "%s:%s.\n", | |
2395 | __func__, info->xbdev->otherend); | |
2396 | ||
2397 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
2398 | "sectors", "%llu", §ors, | |
2399 | "info", "%u", &binfo, | |
2400 | "sector-size", "%lu", §or_size, | |
2401 | NULL); | |
2402 | if (err) { | |
2403 | xenbus_dev_fatal(info->xbdev, err, | |
2404 | "reading backend fields at %s", | |
2405 | info->xbdev->otherend); | |
2406 | return; | |
2407 | } | |
2408 | ||
7c4d7d71 SB |
2409 | /* |
2410 | * physcial-sector-size is a newer field, so old backends may not | |
2411 | * provide this. Assume physical sector size to be the same as | |
2412 | * sector_size in that case. | |
2413 | */ | |
2414 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
2415 | "physical-sector-size", "%u", &physical_sector_size); | |
2416 | if (err != 1) | |
2417 | physical_sector_size = sector_size; | |
2418 | ||
3df0e505 BL |
2419 | blkfront_gather_backend_features(info); |
2420 | for (i = 0; i < info->nr_rings; i++) { | |
2421 | err = blkfront_setup_indirect(&info->rinfo[i]); | |
2422 | if (err) { | |
2423 | xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s", | |
2424 | info->xbdev->otherend); | |
2425 | blkif_free(info, 0); | |
2426 | break; | |
2427 | } | |
402b27f9 RPM |
2428 | } |
2429 | ||
7c4d7d71 SB |
2430 | err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size, |
2431 | physical_sector_size); | |
9f27ee59 JF |
2432 | if (err) { |
2433 | xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", | |
2434 | info->xbdev->otherend); | |
2435 | return; | |
2436 | } | |
2437 | ||
2438 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
2439 | ||
2440 | /* Kick pending requests. */ | |
9f27ee59 | 2441 | info->connected = BLKIF_STATE_CONNECTED; |
3df0e505 BL |
2442 | for (i = 0; i < info->nr_rings; i++) |
2443 | kick_pending_request_queues(&info->rinfo[i]); | |
9f27ee59 | 2444 | |
0d52c756 | 2445 | device_add_disk(&info->xbdev->dev, info->gd); |
1d78d705 CL |
2446 | |
2447 | info->is_ready = 1; | |
9f27ee59 JF |
2448 | } |
2449 | ||
9f27ee59 JF |
2450 | /** |
2451 | * Callback received when the backend's state changes. | |
2452 | */ | |
203fd61f | 2453 | static void blkback_changed(struct xenbus_device *dev, |
9f27ee59 JF |
2454 | enum xenbus_state backend_state) |
2455 | { | |
a1b4b12b | 2456 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 | 2457 | |
203fd61f | 2458 | dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); |
9f27ee59 JF |
2459 | |
2460 | switch (backend_state) { | |
9f27ee59 | 2461 | case XenbusStateInitWait: |
a9b54bb9 BL |
2462 | if (dev->state != XenbusStateInitialising) |
2463 | break; | |
c31ecf6c | 2464 | if (talk_to_blkback(dev, info)) |
8ab0144a | 2465 | break; |
8ab0144a | 2466 | case XenbusStateInitialising: |
9f27ee59 | 2467 | case XenbusStateInitialised: |
b78c9512 NI |
2468 | case XenbusStateReconfiguring: |
2469 | case XenbusStateReconfigured: | |
9f27ee59 | 2470 | case XenbusStateUnknown: |
9f27ee59 JF |
2471 | break; |
2472 | ||
2473 | case XenbusStateConnected: | |
efd15352 BL |
2474 | /* |
2475 | * talk_to_blkback sets state to XenbusStateInitialised | |
2476 | * and blkfront_connect sets it to XenbusStateConnected | |
2477 | * (if connection went OK). | |
2478 | * | |
2479 | * If the backend (or toolstack) decides to poke at backend | |
2480 | * state (and re-trigger the watch by setting the state repeatedly | |
2481 | * to XenbusStateConnected (4)) we need to deal with this. | |
2482 | * This is allowed as this is used to communicate to the guest | |
2483 | * that the size of disk has changed! | |
2484 | */ | |
2485 | if ((dev->state != XenbusStateInitialised) && | |
2486 | (dev->state != XenbusStateConnected)) { | |
c31ecf6c KRW |
2487 | if (talk_to_blkback(dev, info)) |
2488 | break; | |
2489 | } | |
efd15352 | 2490 | |
9f27ee59 JF |
2491 | blkfront_connect(info); |
2492 | break; | |
2493 | ||
36613717 DV |
2494 | case XenbusStateClosed: |
2495 | if (dev->state == XenbusStateClosed) | |
2496 | break; | |
2497 | /* Missed the backend's Closing state -- fallthrough */ | |
9f27ee59 | 2498 | case XenbusStateClosing: |
a54c8f0f CA |
2499 | if (info) |
2500 | blkfront_closing(info); | |
9f27ee59 JF |
2501 | break; |
2502 | } | |
2503 | } | |
2504 | ||
fa1bd359 | 2505 | static int blkfront_remove(struct xenbus_device *xbdev) |
9f27ee59 | 2506 | { |
fa1bd359 DS |
2507 | struct blkfront_info *info = dev_get_drvdata(&xbdev->dev); |
2508 | struct block_device *bdev = NULL; | |
2509 | struct gendisk *disk; | |
9f27ee59 | 2510 | |
fa1bd359 | 2511 | dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename); |
9f27ee59 JF |
2512 | |
2513 | blkif_free(info, 0); | |
2514 | ||
fa1bd359 DS |
2515 | mutex_lock(&info->mutex); |
2516 | ||
2517 | disk = info->gd; | |
2518 | if (disk) | |
2519 | bdev = bdget_disk(disk, 0); | |
2520 | ||
2521 | info->xbdev = NULL; | |
2522 | mutex_unlock(&info->mutex); | |
2523 | ||
2524 | if (!bdev) { | |
2525 | kfree(info); | |
2526 | return 0; | |
2527 | } | |
2528 | ||
2529 | /* | |
2530 | * The xbdev was removed before we reached the Closed | |
2531 | * state. See if it's safe to remove the disk. If the bdev | |
2532 | * isn't closed yet, we let release take care of it. | |
2533 | */ | |
2534 | ||
2535 | mutex_lock(&bdev->bd_mutex); | |
2536 | info = disk->private_data; | |
2537 | ||
d54142c7 DS |
2538 | dev_warn(disk_to_dev(disk), |
2539 | "%s was hot-unplugged, %d stale handles\n", | |
2540 | xbdev->nodename, bdev->bd_openers); | |
2541 | ||
7b32d104 | 2542 | if (info && !bdev->bd_openers) { |
fa1bd359 DS |
2543 | xlvbd_release_gendisk(info); |
2544 | disk->private_data = NULL; | |
0e345826 | 2545 | kfree(info); |
fa1bd359 DS |
2546 | } |
2547 | ||
2548 | mutex_unlock(&bdev->bd_mutex); | |
2549 | bdput(bdev); | |
9f27ee59 JF |
2550 | |
2551 | return 0; | |
2552 | } | |
2553 | ||
1d78d705 CL |
2554 | static int blkfront_is_ready(struct xenbus_device *dev) |
2555 | { | |
a1b4b12b | 2556 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
1d78d705 | 2557 | |
5d7ed20e | 2558 | return info->is_ready && info->xbdev; |
1d78d705 CL |
2559 | } |
2560 | ||
a63c848b | 2561 | static int blkif_open(struct block_device *bdev, fmode_t mode) |
9f27ee59 | 2562 | { |
13961743 DS |
2563 | struct gendisk *disk = bdev->bd_disk; |
2564 | struct blkfront_info *info; | |
2565 | int err = 0; | |
6e9624b8 | 2566 | |
2a48fc0a | 2567 | mutex_lock(&blkfront_mutex); |
6e9624b8 | 2568 | |
13961743 DS |
2569 | info = disk->private_data; |
2570 | if (!info) { | |
2571 | /* xbdev gone */ | |
2572 | err = -ERESTARTSYS; | |
2573 | goto out; | |
2574 | } | |
2575 | ||
2576 | mutex_lock(&info->mutex); | |
2577 | ||
2578 | if (!info->gd) | |
2579 | /* xbdev is closed */ | |
2580 | err = -ERESTARTSYS; | |
2581 | ||
2582 | mutex_unlock(&info->mutex); | |
2583 | ||
13961743 | 2584 | out: |
2a48fc0a | 2585 | mutex_unlock(&blkfront_mutex); |
13961743 | 2586 | return err; |
9f27ee59 JF |
2587 | } |
2588 | ||
db2a144b | 2589 | static void blkif_release(struct gendisk *disk, fmode_t mode) |
9f27ee59 | 2590 | { |
a63c848b | 2591 | struct blkfront_info *info = disk->private_data; |
7fd152f4 DS |
2592 | struct block_device *bdev; |
2593 | struct xenbus_device *xbdev; | |
2594 | ||
2a48fc0a | 2595 | mutex_lock(&blkfront_mutex); |
7fd152f4 DS |
2596 | |
2597 | bdev = bdget_disk(disk, 0); | |
7fd152f4 | 2598 | |
2f089cb8 FP |
2599 | if (!bdev) { |
2600 | WARN(1, "Block device %s yanked out from us!\n", disk->disk_name); | |
2601 | goto out_mutex; | |
2602 | } | |
acfca3c6 DS |
2603 | if (bdev->bd_openers) |
2604 | goto out; | |
2605 | ||
7fd152f4 DS |
2606 | /* |
2607 | * Check if we have been instructed to close. We will have | |
2608 | * deferred this request, because the bdev was still open. | |
2609 | */ | |
2610 | ||
2611 | mutex_lock(&info->mutex); | |
2612 | xbdev = info->xbdev; | |
2613 | ||
2614 | if (xbdev && xbdev->state == XenbusStateClosing) { | |
2615 | /* pending switch to state closed */ | |
d54142c7 | 2616 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2617 | xlvbd_release_gendisk(info); |
2618 | xenbus_frontend_closed(info->xbdev); | |
2619 | } | |
2620 | ||
2621 | mutex_unlock(&info->mutex); | |
2622 | ||
2623 | if (!xbdev) { | |
2624 | /* sudden device removal */ | |
d54142c7 | 2625 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
2626 | xlvbd_release_gendisk(info); |
2627 | disk->private_data = NULL; | |
2628 | kfree(info); | |
9f27ee59 | 2629 | } |
7fd152f4 | 2630 | |
a4cc14ec | 2631 | out: |
dad5cf65 | 2632 | bdput(bdev); |
2f089cb8 | 2633 | out_mutex: |
2a48fc0a | 2634 | mutex_unlock(&blkfront_mutex); |
9f27ee59 JF |
2635 | } |
2636 | ||
83d5cde4 | 2637 | static const struct block_device_operations xlvbd_block_fops = |
9f27ee59 JF |
2638 | { |
2639 | .owner = THIS_MODULE, | |
a63c848b AV |
2640 | .open = blkif_open, |
2641 | .release = blkif_release, | |
597592d9 | 2642 | .getgeo = blkif_getgeo, |
8a6cfeb6 | 2643 | .ioctl = blkif_ioctl, |
9f27ee59 JF |
2644 | }; |
2645 | ||
2646 | ||
ec9c42ec | 2647 | static const struct xenbus_device_id blkfront_ids[] = { |
9f27ee59 JF |
2648 | { "vbd" }, |
2649 | { "" } | |
2650 | }; | |
2651 | ||
95afae48 DV |
2652 | static struct xenbus_driver blkfront_driver = { |
2653 | .ids = blkfront_ids, | |
9f27ee59 JF |
2654 | .probe = blkfront_probe, |
2655 | .remove = blkfront_remove, | |
2656 | .resume = blkfront_resume, | |
203fd61f | 2657 | .otherend_changed = blkback_changed, |
1d78d705 | 2658 | .is_ready = blkfront_is_ready, |
95afae48 | 2659 | }; |
9f27ee59 JF |
2660 | |
2661 | static int __init xlblk_init(void) | |
2662 | { | |
469738e6 | 2663 | int ret; |
28d949bc | 2664 | int nr_cpus = num_online_cpus(); |
469738e6 | 2665 | |
6e833587 | 2666 | if (!xen_domain()) |
9f27ee59 JF |
2667 | return -ENODEV; |
2668 | ||
9cce2914 | 2669 | if (xen_blkif_max_ring_order > XENBUS_MAX_RING_GRANT_ORDER) { |
86839c56 | 2670 | pr_info("Invalid max_ring_order (%d), will use default max: %d.\n", |
9cce2914 | 2671 | xen_blkif_max_ring_order, XENBUS_MAX_RING_GRANT_ORDER); |
45fc8264 | 2672 | xen_blkif_max_ring_order = XENBUS_MAX_RING_GRANT_ORDER; |
86839c56 BL |
2673 | } |
2674 | ||
28d949bc BL |
2675 | if (xen_blkif_max_queues > nr_cpus) { |
2676 | pr_info("Invalid max_queues (%d), will use default max: %d.\n", | |
2677 | xen_blkif_max_queues, nr_cpus); | |
2678 | xen_blkif_max_queues = nr_cpus; | |
2679 | } | |
2680 | ||
51c71a3b | 2681 | if (!xen_has_pv_disk_devices()) |
b9136d20 IM |
2682 | return -ENODEV; |
2683 | ||
9f27ee59 JF |
2684 | if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { |
2685 | printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", | |
2686 | XENVBD_MAJOR, DEV_NAME); | |
2687 | return -ENODEV; | |
2688 | } | |
2689 | ||
73db144b | 2690 | ret = xenbus_register_frontend(&blkfront_driver); |
469738e6 LE |
2691 | if (ret) { |
2692 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2693 | return ret; | |
2694 | } | |
2695 | ||
2696 | return 0; | |
9f27ee59 JF |
2697 | } |
2698 | module_init(xlblk_init); | |
2699 | ||
2700 | ||
5a60d0cd | 2701 | static void __exit xlblk_exit(void) |
9f27ee59 | 2702 | { |
8605067f JB |
2703 | xenbus_unregister_driver(&blkfront_driver); |
2704 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
2705 | kfree(minors); | |
9f27ee59 JF |
2706 | } |
2707 | module_exit(xlblk_exit); | |
2708 | ||
2709 | MODULE_DESCRIPTION("Xen virtual block device frontend"); | |
2710 | MODULE_LICENSE("GPL"); | |
2711 | MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR); | |
d2f0c52b | 2712 | MODULE_ALIAS("xen:vbd"); |
4f93f09b | 2713 | MODULE_ALIAS("xenblk"); |