Commit | Line | Data |
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9f27ee59 JF |
1 | /* |
2 | * blkfront.c | |
3 | * | |
4 | * XenLinux virtual block device driver. | |
5 | * | |
6 | * Copyright (c) 2003-2004, Keir Fraser & Steve Hand | |
7 | * Modifications by Mark A. Williamson are (c) Intel Research Cambridge | |
8 | * Copyright (c) 2004, Christian Limpach | |
9 | * Copyright (c) 2004, Andrew Warfield | |
10 | * Copyright (c) 2005, Christopher Clark | |
11 | * Copyright (c) 2005, XenSource Ltd | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or | |
14 | * modify it under the terms of the GNU General Public License version 2 | |
15 | * as published by the Free Software Foundation; or, when distributed | |
16 | * separately from the Linux kernel or incorporated into other | |
17 | * software packages, subject to the following license: | |
18 | * | |
19 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
20 | * of this source file (the "Software"), to deal in the Software without | |
21 | * restriction, including without limitation the rights to use, copy, modify, | |
22 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
23 | * and to permit persons to whom the Software is furnished to do so, subject to | |
24 | * the following conditions: | |
25 | * | |
26 | * The above copyright notice and this permission notice shall be included in | |
27 | * all copies or substantial portions of the Software. | |
28 | * | |
29 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
30 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
31 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
32 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
33 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
34 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
35 | * IN THE SOFTWARE. | |
36 | */ | |
37 | ||
38 | #include <linux/interrupt.h> | |
39 | #include <linux/blkdev.h> | |
597592d9 | 40 | #include <linux/hdreg.h> |
440a01a7 | 41 | #include <linux/cdrom.h> |
9f27ee59 | 42 | #include <linux/module.h> |
5a0e3ad6 | 43 | #include <linux/slab.h> |
2a48fc0a | 44 | #include <linux/mutex.h> |
9e973e64 | 45 | #include <linux/scatterlist.h> |
34ae2e47 | 46 | #include <linux/bitmap.h> |
9f27ee59 | 47 | |
1ccbf534 | 48 | #include <xen/xen.h> |
9f27ee59 JF |
49 | #include <xen/xenbus.h> |
50 | #include <xen/grant_table.h> | |
51 | #include <xen/events.h> | |
52 | #include <xen/page.h> | |
c1c5413a | 53 | #include <xen/platform_pci.h> |
9f27ee59 JF |
54 | |
55 | #include <xen/interface/grant_table.h> | |
56 | #include <xen/interface/io/blkif.h> | |
3e334239 | 57 | #include <xen/interface/io/protocols.h> |
9f27ee59 JF |
58 | |
59 | #include <asm/xen/hypervisor.h> | |
60 | ||
61 | enum blkif_state { | |
62 | BLKIF_STATE_DISCONNECTED, | |
63 | BLKIF_STATE_CONNECTED, | |
64 | BLKIF_STATE_SUSPENDED, | |
65 | }; | |
66 | ||
67 | struct blk_shadow { | |
68 | struct blkif_request req; | |
a945b980 | 69 | struct request *request; |
9f27ee59 JF |
70 | unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
71 | }; | |
72 | ||
2a48fc0a | 73 | static DEFINE_MUTEX(blkfront_mutex); |
83d5cde4 | 74 | static const struct block_device_operations xlvbd_block_fops; |
9f27ee59 | 75 | |
667c78af | 76 | #define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE) |
9f27ee59 JF |
77 | |
78 | /* | |
79 | * We have one of these per vbd, whether ide, scsi or 'other'. They | |
80 | * hang in private_data off the gendisk structure. We may end up | |
81 | * putting all kinds of interesting stuff here :-) | |
82 | */ | |
83 | struct blkfront_info | |
84 | { | |
3467811e | 85 | spinlock_t io_lock; |
b70f5fa0 | 86 | struct mutex mutex; |
9f27ee59 | 87 | struct xenbus_device *xbdev; |
9f27ee59 JF |
88 | struct gendisk *gd; |
89 | int vdevice; | |
90 | blkif_vdev_t handle; | |
91 | enum blkif_state connected; | |
92 | int ring_ref; | |
93 | struct blkif_front_ring ring; | |
9e973e64 | 94 | struct scatterlist sg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
9f27ee59 JF |
95 | unsigned int evtchn, irq; |
96 | struct request_queue *rq; | |
97 | struct work_struct work; | |
98 | struct gnttab_free_callback callback; | |
99 | struct blk_shadow shadow[BLK_RING_SIZE]; | |
100 | unsigned long shadow_free; | |
4913efe4 | 101 | unsigned int feature_flush; |
edf6ef59 | 102 | unsigned int flush_op; |
5ea42986 KRW |
103 | unsigned int feature_discard:1; |
104 | unsigned int feature_secdiscard:1; | |
ed30bf31 LD |
105 | unsigned int discard_granularity; |
106 | unsigned int discard_alignment; | |
1d78d705 | 107 | int is_ready; |
9f27ee59 JF |
108 | }; |
109 | ||
0e345826 JB |
110 | static unsigned int nr_minors; |
111 | static unsigned long *minors; | |
112 | static DEFINE_SPINLOCK(minor_lock); | |
113 | ||
9f27ee59 JF |
114 | #define MAXIMUM_OUTSTANDING_BLOCK_REQS \ |
115 | (BLKIF_MAX_SEGMENTS_PER_REQUEST * BLK_RING_SIZE) | |
116 | #define GRANT_INVALID_REF 0 | |
117 | ||
118 | #define PARTS_PER_DISK 16 | |
9246b5f0 | 119 | #define PARTS_PER_EXT_DISK 256 |
9f27ee59 JF |
120 | |
121 | #define BLKIF_MAJOR(dev) ((dev)>>8) | |
122 | #define BLKIF_MINOR(dev) ((dev) & 0xff) | |
123 | ||
9246b5f0 CL |
124 | #define EXT_SHIFT 28 |
125 | #define EXTENDED (1<<EXT_SHIFT) | |
126 | #define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED)) | |
127 | #define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED)) | |
c80a4209 SS |
128 | #define EMULATED_HD_DISK_MINOR_OFFSET (0) |
129 | #define EMULATED_HD_DISK_NAME_OFFSET (EMULATED_HD_DISK_MINOR_OFFSET / 256) | |
196cfe2a SB |
130 | #define EMULATED_SD_DISK_MINOR_OFFSET (0) |
131 | #define EMULATED_SD_DISK_NAME_OFFSET (EMULATED_SD_DISK_MINOR_OFFSET / 256) | |
9f27ee59 | 132 | |
9246b5f0 | 133 | #define DEV_NAME "xvd" /* name in /dev */ |
9f27ee59 JF |
134 | |
135 | static int get_id_from_freelist(struct blkfront_info *info) | |
136 | { | |
137 | unsigned long free = info->shadow_free; | |
b9ed7252 | 138 | BUG_ON(free >= BLK_RING_SIZE); |
97e36834 KRW |
139 | info->shadow_free = info->shadow[free].req.u.rw.id; |
140 | info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */ | |
9f27ee59 JF |
141 | return free; |
142 | } | |
143 | ||
6878c32e | 144 | static int add_id_to_freelist(struct blkfront_info *info, |
9f27ee59 JF |
145 | unsigned long id) |
146 | { | |
6878c32e KRW |
147 | if (info->shadow[id].req.u.rw.id != id) |
148 | return -EINVAL; | |
149 | if (info->shadow[id].request == NULL) | |
150 | return -EINVAL; | |
97e36834 | 151 | info->shadow[id].req.u.rw.id = info->shadow_free; |
a945b980 | 152 | info->shadow[id].request = NULL; |
9f27ee59 | 153 | info->shadow_free = id; |
6878c32e | 154 | return 0; |
9f27ee59 JF |
155 | } |
156 | ||
6878c32e KRW |
157 | static const char *op_name(int op) |
158 | { | |
159 | static const char *const names[] = { | |
160 | [BLKIF_OP_READ] = "read", | |
161 | [BLKIF_OP_WRITE] = "write", | |
162 | [BLKIF_OP_WRITE_BARRIER] = "barrier", | |
163 | [BLKIF_OP_FLUSH_DISKCACHE] = "flush", | |
164 | [BLKIF_OP_DISCARD] = "discard" }; | |
165 | ||
166 | if (op < 0 || op >= ARRAY_SIZE(names)) | |
167 | return "unknown"; | |
168 | ||
169 | if (!names[op]) | |
170 | return "reserved"; | |
171 | ||
172 | return names[op]; | |
173 | } | |
0e345826 JB |
174 | static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) |
175 | { | |
176 | unsigned int end = minor + nr; | |
177 | int rc; | |
178 | ||
179 | if (end > nr_minors) { | |
180 | unsigned long *bitmap, *old; | |
181 | ||
f094148a | 182 | bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap), |
0e345826 JB |
183 | GFP_KERNEL); |
184 | if (bitmap == NULL) | |
185 | return -ENOMEM; | |
186 | ||
187 | spin_lock(&minor_lock); | |
188 | if (end > nr_minors) { | |
189 | old = minors; | |
190 | memcpy(bitmap, minors, | |
191 | BITS_TO_LONGS(nr_minors) * sizeof(*bitmap)); | |
192 | minors = bitmap; | |
193 | nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG; | |
194 | } else | |
195 | old = bitmap; | |
196 | spin_unlock(&minor_lock); | |
197 | kfree(old); | |
198 | } | |
199 | ||
200 | spin_lock(&minor_lock); | |
201 | if (find_next_bit(minors, end, minor) >= end) { | |
34ae2e47 | 202 | bitmap_set(minors, minor, nr); |
0e345826 JB |
203 | rc = 0; |
204 | } else | |
205 | rc = -EBUSY; | |
206 | spin_unlock(&minor_lock); | |
207 | ||
208 | return rc; | |
209 | } | |
210 | ||
211 | static void xlbd_release_minors(unsigned int minor, unsigned int nr) | |
212 | { | |
213 | unsigned int end = minor + nr; | |
214 | ||
215 | BUG_ON(end > nr_minors); | |
216 | spin_lock(&minor_lock); | |
34ae2e47 | 217 | bitmap_clear(minors, minor, nr); |
0e345826 JB |
218 | spin_unlock(&minor_lock); |
219 | } | |
220 | ||
9f27ee59 JF |
221 | static void blkif_restart_queue_callback(void *arg) |
222 | { | |
223 | struct blkfront_info *info = (struct blkfront_info *)arg; | |
224 | schedule_work(&info->work); | |
225 | } | |
226 | ||
afe42d7d | 227 | static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg) |
597592d9 IC |
228 | { |
229 | /* We don't have real geometry info, but let's at least return | |
230 | values consistent with the size of the device */ | |
231 | sector_t nsect = get_capacity(bd->bd_disk); | |
232 | sector_t cylinders = nsect; | |
233 | ||
234 | hg->heads = 0xff; | |
235 | hg->sectors = 0x3f; | |
236 | sector_div(cylinders, hg->heads * hg->sectors); | |
237 | hg->cylinders = cylinders; | |
238 | if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect) | |
239 | hg->cylinders = 0xffff; | |
240 | return 0; | |
241 | } | |
242 | ||
a63c848b | 243 | static int blkif_ioctl(struct block_device *bdev, fmode_t mode, |
62aa0054 | 244 | unsigned command, unsigned long argument) |
440a01a7 | 245 | { |
a63c848b | 246 | struct blkfront_info *info = bdev->bd_disk->private_data; |
440a01a7 CL |
247 | int i; |
248 | ||
249 | dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n", | |
250 | command, (long)argument); | |
251 | ||
252 | switch (command) { | |
253 | case CDROMMULTISESSION: | |
254 | dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n"); | |
255 | for (i = 0; i < sizeof(struct cdrom_multisession); i++) | |
256 | if (put_user(0, (char __user *)(argument + i))) | |
257 | return -EFAULT; | |
258 | return 0; | |
259 | ||
260 | case CDROM_GET_CAPABILITY: { | |
261 | struct gendisk *gd = info->gd; | |
262 | if (gd->flags & GENHD_FL_CD) | |
263 | return 0; | |
264 | return -EINVAL; | |
265 | } | |
266 | ||
267 | default: | |
268 | /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n", | |
269 | command);*/ | |
270 | return -EINVAL; /* same return as native Linux */ | |
271 | } | |
272 | ||
273 | return 0; | |
274 | } | |
275 | ||
9f27ee59 | 276 | /* |
c64e38ea | 277 | * Generate a Xen blkfront IO request from a blk layer request. Reads |
edf6ef59 | 278 | * and writes are handled as expected. |
9f27ee59 | 279 | * |
c64e38ea | 280 | * @req: a request struct |
9f27ee59 JF |
281 | */ |
282 | static int blkif_queue_request(struct request *req) | |
283 | { | |
284 | struct blkfront_info *info = req->rq_disk->private_data; | |
285 | unsigned long buffer_mfn; | |
286 | struct blkif_request *ring_req; | |
9f27ee59 JF |
287 | unsigned long id; |
288 | unsigned int fsect, lsect; | |
9e973e64 | 289 | int i, ref; |
9f27ee59 | 290 | grant_ref_t gref_head; |
9e973e64 | 291 | struct scatterlist *sg; |
9f27ee59 JF |
292 | |
293 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) | |
294 | return 1; | |
295 | ||
296 | if (gnttab_alloc_grant_references( | |
297 | BLKIF_MAX_SEGMENTS_PER_REQUEST, &gref_head) < 0) { | |
298 | gnttab_request_free_callback( | |
299 | &info->callback, | |
300 | blkif_restart_queue_callback, | |
301 | info, | |
302 | BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
303 | return 1; | |
304 | } | |
305 | ||
306 | /* Fill out a communications ring structure. */ | |
307 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
308 | id = get_id_from_freelist(info); | |
a945b980 | 309 | info->shadow[id].request = req; |
9f27ee59 | 310 | |
97e36834 | 311 | ring_req->u.rw.id = id; |
51de6952 | 312 | ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req); |
97e36834 | 313 | ring_req->u.rw.handle = info->handle; |
9f27ee59 JF |
314 | |
315 | ring_req->operation = rq_data_dir(req) ? | |
316 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
be2f8373 JF |
317 | |
318 | if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) { | |
319 | /* | |
edf6ef59 KRW |
320 | * Ideally we can do an unordered flush-to-disk. In case the |
321 | * backend onlysupports barriers, use that. A barrier request | |
be2f8373 JF |
322 | * a superset of FUA, so we can implement it the same |
323 | * way. (It's also a FLUSH+FUA, since it is | |
324 | * guaranteed ordered WRT previous writes.) | |
325 | */ | |
edf6ef59 | 326 | ring_req->operation = info->flush_op; |
be2f8373 | 327 | } |
9f27ee59 | 328 | |
5ea42986 | 329 | if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE))) { |
ed30bf31 LD |
330 | /* id, sector_number and handle are set above. */ |
331 | ring_req->operation = BLKIF_OP_DISCARD; | |
ed30bf31 | 332 | ring_req->u.discard.nr_sectors = blk_rq_sectors(req); |
5ea42986 KRW |
333 | if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard) |
334 | ring_req->u.discard.flag = BLKIF_DISCARD_SECURE; | |
335 | else | |
336 | ring_req->u.discard.flag = 0; | |
ed30bf31 | 337 | } else { |
97e36834 KRW |
338 | ring_req->u.rw.nr_segments = blk_rq_map_sg(req->q, req, |
339 | info->sg); | |
340 | BUG_ON(ring_req->u.rw.nr_segments > | |
341 | BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
9e973e64 | 342 | |
97e36834 | 343 | for_each_sg(info->sg, sg, ring_req->u.rw.nr_segments, i) { |
ed30bf31 LD |
344 | buffer_mfn = pfn_to_mfn(page_to_pfn(sg_page(sg))); |
345 | fsect = sg->offset >> 9; | |
346 | lsect = fsect + (sg->length >> 9) - 1; | |
347 | /* install a grant reference. */ | |
348 | ref = gnttab_claim_grant_reference(&gref_head); | |
349 | BUG_ON(ref == -ENOSPC); | |
6c92e699 | 350 | |
ed30bf31 LD |
351 | gnttab_grant_foreign_access_ref( |
352 | ref, | |
353 | info->xbdev->otherend_id, | |
354 | buffer_mfn, | |
355 | rq_data_dir(req)); | |
356 | ||
357 | info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn); | |
358 | ring_req->u.rw.seg[i] = | |
359 | (struct blkif_request_segment) { | |
360 | .gref = ref, | |
361 | .first_sect = fsect, | |
362 | .last_sect = lsect }; | |
363 | } | |
9f27ee59 JF |
364 | } |
365 | ||
366 | info->ring.req_prod_pvt++; | |
367 | ||
368 | /* Keep a private copy so we can reissue requests when recovering. */ | |
369 | info->shadow[id].req = *ring_req; | |
370 | ||
371 | gnttab_free_grant_references(gref_head); | |
372 | ||
373 | return 0; | |
374 | } | |
375 | ||
376 | ||
377 | static inline void flush_requests(struct blkfront_info *info) | |
378 | { | |
379 | int notify; | |
380 | ||
381 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify); | |
382 | ||
383 | if (notify) | |
384 | notify_remote_via_irq(info->irq); | |
385 | } | |
386 | ||
387 | /* | |
388 | * do_blkif_request | |
389 | * read a block; request is in a request queue | |
390 | */ | |
165125e1 | 391 | static void do_blkif_request(struct request_queue *rq) |
9f27ee59 JF |
392 | { |
393 | struct blkfront_info *info = NULL; | |
394 | struct request *req; | |
395 | int queued; | |
396 | ||
397 | pr_debug("Entered do_blkif_request\n"); | |
398 | ||
399 | queued = 0; | |
400 | ||
9934c8c0 | 401 | while ((req = blk_peek_request(rq)) != NULL) { |
9f27ee59 | 402 | info = req->rq_disk->private_data; |
9f27ee59 JF |
403 | |
404 | if (RING_FULL(&info->ring)) | |
405 | goto wait; | |
406 | ||
9934c8c0 | 407 | blk_start_request(req); |
296b2f6a | 408 | |
d11e6158 KRW |
409 | if ((req->cmd_type != REQ_TYPE_FS) || |
410 | ((req->cmd_flags & (REQ_FLUSH | REQ_FUA)) && | |
411 | !info->flush_op)) { | |
296b2f6a TH |
412 | __blk_end_request_all(req, -EIO); |
413 | continue; | |
414 | } | |
415 | ||
9f27ee59 | 416 | pr_debug("do_blk_req %p: cmd %p, sec %lx, " |
83096ebf TH |
417 | "(%u/%u) buffer:%p [%s]\n", |
418 | req, req->cmd, (unsigned long)blk_rq_pos(req), | |
419 | blk_rq_cur_sectors(req), blk_rq_sectors(req), | |
420 | req->buffer, rq_data_dir(req) ? "write" : "read"); | |
9f27ee59 | 421 | |
9f27ee59 JF |
422 | if (blkif_queue_request(req)) { |
423 | blk_requeue_request(rq, req); | |
424 | wait: | |
425 | /* Avoid pointless unplugs. */ | |
426 | blk_stop_queue(rq); | |
427 | break; | |
428 | } | |
429 | ||
430 | queued++; | |
431 | } | |
432 | ||
433 | if (queued != 0) | |
434 | flush_requests(info); | |
435 | } | |
436 | ||
437 | static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size) | |
438 | { | |
165125e1 | 439 | struct request_queue *rq; |
ed30bf31 | 440 | struct blkfront_info *info = gd->private_data; |
9f27ee59 | 441 | |
3467811e | 442 | rq = blk_init_queue(do_blkif_request, &info->io_lock); |
9f27ee59 JF |
443 | if (rq == NULL) |
444 | return -1; | |
445 | ||
66d352e1 | 446 | queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); |
9f27ee59 | 447 | |
ed30bf31 LD |
448 | if (info->feature_discard) { |
449 | queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, rq); | |
450 | blk_queue_max_discard_sectors(rq, get_capacity(gd)); | |
451 | rq->limits.discard_granularity = info->discard_granularity; | |
452 | rq->limits.discard_alignment = info->discard_alignment; | |
5ea42986 KRW |
453 | if (info->feature_secdiscard) |
454 | queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, rq); | |
ed30bf31 LD |
455 | } |
456 | ||
9f27ee59 | 457 | /* Hard sector size and max sectors impersonate the equiv. hardware. */ |
e1defc4f | 458 | blk_queue_logical_block_size(rq, sector_size); |
086fa5ff | 459 | blk_queue_max_hw_sectors(rq, 512); |
9f27ee59 JF |
460 | |
461 | /* Each segment in a request is up to an aligned page in size. */ | |
462 | blk_queue_segment_boundary(rq, PAGE_SIZE - 1); | |
463 | blk_queue_max_segment_size(rq, PAGE_SIZE); | |
464 | ||
465 | /* Ensure a merged request will fit in a single I/O ring slot. */ | |
8a78362c | 466 | blk_queue_max_segments(rq, BLKIF_MAX_SEGMENTS_PER_REQUEST); |
9f27ee59 JF |
467 | |
468 | /* Make sure buffer addresses are sector-aligned. */ | |
469 | blk_queue_dma_alignment(rq, 511); | |
470 | ||
1c91fe1a IC |
471 | /* Make sure we don't use bounce buffers. */ |
472 | blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY); | |
473 | ||
9f27ee59 JF |
474 | gd->queue = rq; |
475 | ||
476 | return 0; | |
477 | } | |
478 | ||
479 | ||
4913efe4 | 480 | static void xlvbd_flush(struct blkfront_info *info) |
9f27ee59 | 481 | { |
4913efe4 | 482 | blk_queue_flush(info->rq, info->feature_flush); |
edf6ef59 | 483 | printk(KERN_INFO "blkfront: %s: %s: %s\n", |
4913efe4 | 484 | info->gd->disk_name, |
edf6ef59 KRW |
485 | info->flush_op == BLKIF_OP_WRITE_BARRIER ? |
486 | "barrier" : (info->flush_op == BLKIF_OP_FLUSH_DISKCACHE ? | |
487 | "flush diskcache" : "barrier or flush"), | |
4913efe4 | 488 | info->feature_flush ? "enabled" : "disabled"); |
9f27ee59 JF |
489 | } |
490 | ||
c80a4209 SS |
491 | static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset) |
492 | { | |
493 | int major; | |
494 | major = BLKIF_MAJOR(vdevice); | |
495 | *minor = BLKIF_MINOR(vdevice); | |
496 | switch (major) { | |
497 | case XEN_IDE0_MAJOR: | |
498 | *offset = (*minor / 64) + EMULATED_HD_DISK_NAME_OFFSET; | |
499 | *minor = ((*minor / 64) * PARTS_PER_DISK) + | |
500 | EMULATED_HD_DISK_MINOR_OFFSET; | |
501 | break; | |
502 | case XEN_IDE1_MAJOR: | |
503 | *offset = (*minor / 64) + 2 + EMULATED_HD_DISK_NAME_OFFSET; | |
504 | *minor = (((*minor / 64) + 2) * PARTS_PER_DISK) + | |
505 | EMULATED_HD_DISK_MINOR_OFFSET; | |
506 | break; | |
507 | case XEN_SCSI_DISK0_MAJOR: | |
508 | *offset = (*minor / PARTS_PER_DISK) + EMULATED_SD_DISK_NAME_OFFSET; | |
509 | *minor = *minor + EMULATED_SD_DISK_MINOR_OFFSET; | |
510 | break; | |
511 | case XEN_SCSI_DISK1_MAJOR: | |
512 | case XEN_SCSI_DISK2_MAJOR: | |
513 | case XEN_SCSI_DISK3_MAJOR: | |
514 | case XEN_SCSI_DISK4_MAJOR: | |
515 | case XEN_SCSI_DISK5_MAJOR: | |
516 | case XEN_SCSI_DISK6_MAJOR: | |
517 | case XEN_SCSI_DISK7_MAJOR: | |
518 | *offset = (*minor / PARTS_PER_DISK) + | |
519 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16) + | |
520 | EMULATED_SD_DISK_NAME_OFFSET; | |
521 | *minor = *minor + | |
522 | ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16 * PARTS_PER_DISK) + | |
523 | EMULATED_SD_DISK_MINOR_OFFSET; | |
524 | break; | |
525 | case XEN_SCSI_DISK8_MAJOR: | |
526 | case XEN_SCSI_DISK9_MAJOR: | |
527 | case XEN_SCSI_DISK10_MAJOR: | |
528 | case XEN_SCSI_DISK11_MAJOR: | |
529 | case XEN_SCSI_DISK12_MAJOR: | |
530 | case XEN_SCSI_DISK13_MAJOR: | |
531 | case XEN_SCSI_DISK14_MAJOR: | |
532 | case XEN_SCSI_DISK15_MAJOR: | |
533 | *offset = (*minor / PARTS_PER_DISK) + | |
534 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16) + | |
535 | EMULATED_SD_DISK_NAME_OFFSET; | |
536 | *minor = *minor + | |
537 | ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16 * PARTS_PER_DISK) + | |
538 | EMULATED_SD_DISK_MINOR_OFFSET; | |
539 | break; | |
540 | case XENVBD_MAJOR: | |
541 | *offset = *minor / PARTS_PER_DISK; | |
542 | break; | |
543 | default: | |
544 | printk(KERN_WARNING "blkfront: your disk configuration is " | |
545 | "incorrect, please use an xvd device instead\n"); | |
546 | return -ENODEV; | |
547 | } | |
548 | return 0; | |
549 | } | |
9f27ee59 | 550 | |
e77c78c0 JB |
551 | static char *encode_disk_name(char *ptr, unsigned int n) |
552 | { | |
553 | if (n >= 26) | |
554 | ptr = encode_disk_name(ptr, n / 26 - 1); | |
555 | *ptr = 'a' + n % 26; | |
556 | return ptr + 1; | |
557 | } | |
558 | ||
9246b5f0 CL |
559 | static int xlvbd_alloc_gendisk(blkif_sector_t capacity, |
560 | struct blkfront_info *info, | |
561 | u16 vdisk_info, u16 sector_size) | |
9f27ee59 JF |
562 | { |
563 | struct gendisk *gd; | |
564 | int nr_minors = 1; | |
c80a4209 | 565 | int err; |
9246b5f0 CL |
566 | unsigned int offset; |
567 | int minor; | |
568 | int nr_parts; | |
e77c78c0 | 569 | char *ptr; |
9f27ee59 JF |
570 | |
571 | BUG_ON(info->gd != NULL); | |
572 | BUG_ON(info->rq != NULL); | |
573 | ||
9246b5f0 CL |
574 | if ((info->vdevice>>EXT_SHIFT) > 1) { |
575 | /* this is above the extended range; something is wrong */ | |
576 | printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice); | |
577 | return -ENODEV; | |
578 | } | |
579 | ||
580 | if (!VDEV_IS_EXTENDED(info->vdevice)) { | |
c80a4209 SS |
581 | err = xen_translate_vdev(info->vdevice, &minor, &offset); |
582 | if (err) | |
583 | return err; | |
584 | nr_parts = PARTS_PER_DISK; | |
9246b5f0 CL |
585 | } else { |
586 | minor = BLKIF_MINOR_EXT(info->vdevice); | |
587 | nr_parts = PARTS_PER_EXT_DISK; | |
c80a4209 | 588 | offset = minor / nr_parts; |
89153b5c | 589 | if (xen_hvm_domain() && offset < EMULATED_HD_DISK_NAME_OFFSET + 4) |
c80a4209 SS |
590 | printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with " |
591 | "emulated IDE disks,\n\t choose an xvd device name" | |
592 | "from xvde on\n", info->vdevice); | |
9246b5f0 | 593 | } |
e77c78c0 JB |
594 | if (minor >> MINORBITS) { |
595 | pr_warn("blkfront: %#x's minor (%#x) out of range; ignoring\n", | |
596 | info->vdevice, minor); | |
597 | return -ENODEV; | |
598 | } | |
9246b5f0 CL |
599 | |
600 | if ((minor % nr_parts) == 0) | |
601 | nr_minors = nr_parts; | |
9f27ee59 | 602 | |
0e345826 JB |
603 | err = xlbd_reserve_minors(minor, nr_minors); |
604 | if (err) | |
605 | goto out; | |
606 | err = -ENODEV; | |
607 | ||
9f27ee59 JF |
608 | gd = alloc_disk(nr_minors); |
609 | if (gd == NULL) | |
0e345826 | 610 | goto release; |
9f27ee59 | 611 | |
e77c78c0 JB |
612 | strcpy(gd->disk_name, DEV_NAME); |
613 | ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset); | |
614 | BUG_ON(ptr >= gd->disk_name + DISK_NAME_LEN); | |
615 | if (nr_minors > 1) | |
616 | *ptr = 0; | |
617 | else | |
618 | snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr, | |
619 | "%d", minor & (nr_parts - 1)); | |
9f27ee59 JF |
620 | |
621 | gd->major = XENVBD_MAJOR; | |
622 | gd->first_minor = minor; | |
623 | gd->fops = &xlvbd_block_fops; | |
624 | gd->private_data = info; | |
625 | gd->driverfs_dev = &(info->xbdev->dev); | |
626 | set_capacity(gd, capacity); | |
627 | ||
628 | if (xlvbd_init_blk_queue(gd, sector_size)) { | |
629 | del_gendisk(gd); | |
0e345826 | 630 | goto release; |
9f27ee59 JF |
631 | } |
632 | ||
633 | info->rq = gd->queue; | |
634 | info->gd = gd; | |
635 | ||
4913efe4 | 636 | xlvbd_flush(info); |
9f27ee59 JF |
637 | |
638 | if (vdisk_info & VDISK_READONLY) | |
639 | set_disk_ro(gd, 1); | |
640 | ||
641 | if (vdisk_info & VDISK_REMOVABLE) | |
642 | gd->flags |= GENHD_FL_REMOVABLE; | |
643 | ||
644 | if (vdisk_info & VDISK_CDROM) | |
645 | gd->flags |= GENHD_FL_CD; | |
646 | ||
647 | return 0; | |
648 | ||
0e345826 JB |
649 | release: |
650 | xlbd_release_minors(minor, nr_minors); | |
9f27ee59 JF |
651 | out: |
652 | return err; | |
653 | } | |
654 | ||
a66b5aeb DS |
655 | static void xlvbd_release_gendisk(struct blkfront_info *info) |
656 | { | |
657 | unsigned int minor, nr_minors; | |
658 | unsigned long flags; | |
659 | ||
660 | if (info->rq == NULL) | |
661 | return; | |
662 | ||
3467811e | 663 | spin_lock_irqsave(&info->io_lock, flags); |
a66b5aeb DS |
664 | |
665 | /* No more blkif_request(). */ | |
666 | blk_stop_queue(info->rq); | |
667 | ||
668 | /* No more gnttab callback work. */ | |
669 | gnttab_cancel_free_callback(&info->callback); | |
3467811e | 670 | spin_unlock_irqrestore(&info->io_lock, flags); |
a66b5aeb DS |
671 | |
672 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 673 | flush_work(&info->work); |
a66b5aeb DS |
674 | |
675 | del_gendisk(info->gd); | |
676 | ||
677 | minor = info->gd->first_minor; | |
678 | nr_minors = info->gd->minors; | |
679 | xlbd_release_minors(minor, nr_minors); | |
680 | ||
681 | blk_cleanup_queue(info->rq); | |
682 | info->rq = NULL; | |
683 | ||
684 | put_disk(info->gd); | |
685 | info->gd = NULL; | |
686 | } | |
687 | ||
9f27ee59 JF |
688 | static void kick_pending_request_queues(struct blkfront_info *info) |
689 | { | |
690 | if (!RING_FULL(&info->ring)) { | |
691 | /* Re-enable calldowns. */ | |
692 | blk_start_queue(info->rq); | |
693 | /* Kick things off immediately. */ | |
694 | do_blkif_request(info->rq); | |
695 | } | |
696 | } | |
697 | ||
698 | static void blkif_restart_queue(struct work_struct *work) | |
699 | { | |
700 | struct blkfront_info *info = container_of(work, struct blkfront_info, work); | |
701 | ||
3467811e | 702 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
703 | if (info->connected == BLKIF_STATE_CONNECTED) |
704 | kick_pending_request_queues(info); | |
3467811e | 705 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
706 | } |
707 | ||
708 | static void blkif_free(struct blkfront_info *info, int suspend) | |
709 | { | |
710 | /* Prevent new requests being issued until we fix things up. */ | |
3467811e | 711 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
712 | info->connected = suspend ? |
713 | BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; | |
714 | /* No more blkif_request(). */ | |
715 | if (info->rq) | |
716 | blk_stop_queue(info->rq); | |
717 | /* No more gnttab callback work. */ | |
718 | gnttab_cancel_free_callback(&info->callback); | |
3467811e | 719 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
720 | |
721 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
43829731 | 722 | flush_work(&info->work); |
9f27ee59 JF |
723 | |
724 | /* Free resources associated with old device channel. */ | |
725 | if (info->ring_ref != GRANT_INVALID_REF) { | |
726 | gnttab_end_foreign_access(info->ring_ref, 0, | |
727 | (unsigned long)info->ring.sring); | |
728 | info->ring_ref = GRANT_INVALID_REF; | |
729 | info->ring.sring = NULL; | |
730 | } | |
731 | if (info->irq) | |
732 | unbind_from_irqhandler(info->irq, info); | |
733 | info->evtchn = info->irq = 0; | |
734 | ||
735 | } | |
736 | ||
737 | static void blkif_completion(struct blk_shadow *s) | |
738 | { | |
739 | int i; | |
5ea42986 KRW |
740 | /* Do not let BLKIF_OP_DISCARD as nr_segment is in the same place |
741 | * flag. */ | |
97e36834 | 742 | for (i = 0; i < s->req.u.rw.nr_segments; i++) |
51de6952 | 743 | gnttab_end_foreign_access(s->req.u.rw.seg[i].gref, 0, 0UL); |
9f27ee59 JF |
744 | } |
745 | ||
746 | static irqreturn_t blkif_interrupt(int irq, void *dev_id) | |
747 | { | |
748 | struct request *req; | |
749 | struct blkif_response *bret; | |
750 | RING_IDX i, rp; | |
751 | unsigned long flags; | |
752 | struct blkfront_info *info = (struct blkfront_info *)dev_id; | |
f530f036 | 753 | int error; |
9f27ee59 | 754 | |
3467811e | 755 | spin_lock_irqsave(&info->io_lock, flags); |
9f27ee59 JF |
756 | |
757 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { | |
3467811e | 758 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
759 | return IRQ_HANDLED; |
760 | } | |
761 | ||
762 | again: | |
763 | rp = info->ring.sring->rsp_prod; | |
764 | rmb(); /* Ensure we see queued responses up to 'rp'. */ | |
765 | ||
766 | for (i = info->ring.rsp_cons; i != rp; i++) { | |
767 | unsigned long id; | |
9f27ee59 JF |
768 | |
769 | bret = RING_GET_RESPONSE(&info->ring, i); | |
770 | id = bret->id; | |
6878c32e KRW |
771 | /* |
772 | * The backend has messed up and given us an id that we would | |
773 | * never have given to it (we stamp it up to BLK_RING_SIZE - | |
774 | * look in get_id_from_freelist. | |
775 | */ | |
776 | if (id >= BLK_RING_SIZE) { | |
777 | WARN(1, "%s: response to %s has incorrect id (%ld)\n", | |
778 | info->gd->disk_name, op_name(bret->operation), id); | |
779 | /* We can't safely get the 'struct request' as | |
780 | * the id is busted. */ | |
781 | continue; | |
782 | } | |
a945b980 | 783 | req = info->shadow[id].request; |
9f27ee59 | 784 | |
5ea42986 KRW |
785 | if (bret->operation != BLKIF_OP_DISCARD) |
786 | blkif_completion(&info->shadow[id]); | |
9f27ee59 | 787 | |
6878c32e KRW |
788 | if (add_id_to_freelist(info, id)) { |
789 | WARN(1, "%s: response to %s (id %ld) couldn't be recycled!\n", | |
790 | info->gd->disk_name, op_name(bret->operation), id); | |
791 | continue; | |
792 | } | |
9f27ee59 | 793 | |
f530f036 | 794 | error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO; |
9f27ee59 | 795 | switch (bret->operation) { |
ed30bf31 LD |
796 | case BLKIF_OP_DISCARD: |
797 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
798 | struct request_queue *rq = info->rq; | |
6878c32e KRW |
799 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
800 | info->gd->disk_name, op_name(bret->operation)); | |
ed30bf31 LD |
801 | error = -EOPNOTSUPP; |
802 | info->feature_discard = 0; | |
5ea42986 | 803 | info->feature_secdiscard = 0; |
ed30bf31 | 804 | queue_flag_clear(QUEUE_FLAG_DISCARD, rq); |
5ea42986 | 805 | queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq); |
ed30bf31 LD |
806 | } |
807 | __blk_end_request_all(req, error); | |
808 | break; | |
edf6ef59 | 809 | case BLKIF_OP_FLUSH_DISKCACHE: |
9f27ee59 JF |
810 | case BLKIF_OP_WRITE_BARRIER: |
811 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
6878c32e KRW |
812 | printk(KERN_WARNING "blkfront: %s: %s op failed\n", |
813 | info->gd->disk_name, op_name(bret->operation)); | |
f530f036 | 814 | error = -EOPNOTSUPP; |
dcb8baec JF |
815 | } |
816 | if (unlikely(bret->status == BLKIF_RSP_ERROR && | |
97e36834 | 817 | info->shadow[id].req.u.rw.nr_segments == 0)) { |
6878c32e KRW |
818 | printk(KERN_WARNING "blkfront: %s: empty %s op failed\n", |
819 | info->gd->disk_name, op_name(bret->operation)); | |
dcb8baec JF |
820 | error = -EOPNOTSUPP; |
821 | } | |
822 | if (unlikely(error)) { | |
823 | if (error == -EOPNOTSUPP) | |
824 | error = 0; | |
4913efe4 | 825 | info->feature_flush = 0; |
edf6ef59 | 826 | info->flush_op = 0; |
4913efe4 | 827 | xlvbd_flush(info); |
9f27ee59 JF |
828 | } |
829 | /* fall through */ | |
830 | case BLKIF_OP_READ: | |
831 | case BLKIF_OP_WRITE: | |
832 | if (unlikely(bret->status != BLKIF_RSP_OKAY)) | |
833 | dev_dbg(&info->xbdev->dev, "Bad return from blkdev data " | |
834 | "request: %x\n", bret->status); | |
835 | ||
40cbbb78 | 836 | __blk_end_request_all(req, error); |
9f27ee59 JF |
837 | break; |
838 | default: | |
839 | BUG(); | |
840 | } | |
841 | } | |
842 | ||
843 | info->ring.rsp_cons = i; | |
844 | ||
845 | if (i != info->ring.req_prod_pvt) { | |
846 | int more_to_do; | |
847 | RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do); | |
848 | if (more_to_do) | |
849 | goto again; | |
850 | } else | |
851 | info->ring.sring->rsp_event = i + 1; | |
852 | ||
853 | kick_pending_request_queues(info); | |
854 | ||
3467811e | 855 | spin_unlock_irqrestore(&info->io_lock, flags); |
9f27ee59 JF |
856 | |
857 | return IRQ_HANDLED; | |
858 | } | |
859 | ||
860 | ||
861 | static int setup_blkring(struct xenbus_device *dev, | |
862 | struct blkfront_info *info) | |
863 | { | |
864 | struct blkif_sring *sring; | |
865 | int err; | |
866 | ||
867 | info->ring_ref = GRANT_INVALID_REF; | |
868 | ||
a144ff09 | 869 | sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH); |
9f27ee59 JF |
870 | if (!sring) { |
871 | xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); | |
872 | return -ENOMEM; | |
873 | } | |
874 | SHARED_RING_INIT(sring); | |
875 | FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE); | |
9e973e64 JA |
876 | |
877 | sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
9f27ee59 JF |
878 | |
879 | err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring)); | |
880 | if (err < 0) { | |
881 | free_page((unsigned long)sring); | |
882 | info->ring.sring = NULL; | |
883 | goto fail; | |
884 | } | |
885 | info->ring_ref = err; | |
886 | ||
887 | err = xenbus_alloc_evtchn(dev, &info->evtchn); | |
888 | if (err) | |
889 | goto fail; | |
890 | ||
89c30f16 TT |
891 | err = bind_evtchn_to_irqhandler(info->evtchn, blkif_interrupt, 0, |
892 | "blkif", info); | |
9f27ee59 JF |
893 | if (err <= 0) { |
894 | xenbus_dev_fatal(dev, err, | |
895 | "bind_evtchn_to_irqhandler failed"); | |
896 | goto fail; | |
897 | } | |
898 | info->irq = err; | |
899 | ||
900 | return 0; | |
901 | fail: | |
902 | blkif_free(info, 0); | |
903 | return err; | |
904 | } | |
905 | ||
906 | ||
907 | /* Common code used when first setting up, and when resuming. */ | |
203fd61f | 908 | static int talk_to_blkback(struct xenbus_device *dev, |
9f27ee59 JF |
909 | struct blkfront_info *info) |
910 | { | |
911 | const char *message = NULL; | |
912 | struct xenbus_transaction xbt; | |
913 | int err; | |
914 | ||
915 | /* Create shared ring, alloc event channel. */ | |
916 | err = setup_blkring(dev, info); | |
917 | if (err) | |
918 | goto out; | |
919 | ||
920 | again: | |
921 | err = xenbus_transaction_start(&xbt); | |
922 | if (err) { | |
923 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
924 | goto destroy_blkring; | |
925 | } | |
926 | ||
927 | err = xenbus_printf(xbt, dev->nodename, | |
928 | "ring-ref", "%u", info->ring_ref); | |
929 | if (err) { | |
930 | message = "writing ring-ref"; | |
931 | goto abort_transaction; | |
932 | } | |
933 | err = xenbus_printf(xbt, dev->nodename, | |
934 | "event-channel", "%u", info->evtchn); | |
935 | if (err) { | |
936 | message = "writing event-channel"; | |
937 | goto abort_transaction; | |
938 | } | |
3e334239 MA |
939 | err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", |
940 | XEN_IO_PROTO_ABI_NATIVE); | |
941 | if (err) { | |
942 | message = "writing protocol"; | |
943 | goto abort_transaction; | |
944 | } | |
9f27ee59 JF |
945 | |
946 | err = xenbus_transaction_end(xbt, 0); | |
947 | if (err) { | |
948 | if (err == -EAGAIN) | |
949 | goto again; | |
950 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
951 | goto destroy_blkring; | |
952 | } | |
953 | ||
954 | xenbus_switch_state(dev, XenbusStateInitialised); | |
955 | ||
956 | return 0; | |
957 | ||
958 | abort_transaction: | |
959 | xenbus_transaction_end(xbt, 1); | |
960 | if (message) | |
961 | xenbus_dev_fatal(dev, err, "%s", message); | |
962 | destroy_blkring: | |
963 | blkif_free(info, 0); | |
964 | out: | |
965 | return err; | |
966 | } | |
967 | ||
9f27ee59 JF |
968 | /** |
969 | * Entry point to this code when a new device is created. Allocate the basic | |
970 | * structures and the ring buffer for communication with the backend, and | |
971 | * inform the backend of the appropriate details for those. Switch to | |
972 | * Initialised state. | |
973 | */ | |
974 | static int blkfront_probe(struct xenbus_device *dev, | |
975 | const struct xenbus_device_id *id) | |
976 | { | |
977 | int err, vdevice, i; | |
978 | struct blkfront_info *info; | |
979 | ||
980 | /* FIXME: Use dynamic device id if this is not set. */ | |
981 | err = xenbus_scanf(XBT_NIL, dev->nodename, | |
982 | "virtual-device", "%i", &vdevice); | |
983 | if (err != 1) { | |
9246b5f0 CL |
984 | /* go looking in the extended area instead */ |
985 | err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext", | |
986 | "%i", &vdevice); | |
987 | if (err != 1) { | |
988 | xenbus_dev_fatal(dev, err, "reading virtual-device"); | |
989 | return err; | |
990 | } | |
9f27ee59 JF |
991 | } |
992 | ||
b98a409b SS |
993 | if (xen_hvm_domain()) { |
994 | char *type; | |
995 | int len; | |
996 | /* no unplug has been done: do not hook devices != xen vbds */ | |
1dc7ce99 | 997 | if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY) { |
b98a409b SS |
998 | int major; |
999 | ||
1000 | if (!VDEV_IS_EXTENDED(vdevice)) | |
1001 | major = BLKIF_MAJOR(vdevice); | |
1002 | else | |
1003 | major = XENVBD_MAJOR; | |
1004 | ||
1005 | if (major != XENVBD_MAJOR) { | |
1006 | printk(KERN_INFO | |
1007 | "%s: HVM does not support vbd %d as xen block device\n", | |
1008 | __FUNCTION__, vdevice); | |
1009 | return -ENODEV; | |
1010 | } | |
1011 | } | |
1012 | /* do not create a PV cdrom device if we are an HVM guest */ | |
1013 | type = xenbus_read(XBT_NIL, dev->nodename, "device-type", &len); | |
1014 | if (IS_ERR(type)) | |
1015 | return -ENODEV; | |
1016 | if (strncmp(type, "cdrom", 5) == 0) { | |
1017 | kfree(type); | |
c1c5413a SS |
1018 | return -ENODEV; |
1019 | } | |
b98a409b | 1020 | kfree(type); |
c1c5413a | 1021 | } |
9f27ee59 JF |
1022 | info = kzalloc(sizeof(*info), GFP_KERNEL); |
1023 | if (!info) { | |
1024 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
1025 | return -ENOMEM; | |
1026 | } | |
1027 | ||
b70f5fa0 | 1028 | mutex_init(&info->mutex); |
3467811e | 1029 | spin_lock_init(&info->io_lock); |
9f27ee59 JF |
1030 | info->xbdev = dev; |
1031 | info->vdevice = vdevice; | |
1032 | info->connected = BLKIF_STATE_DISCONNECTED; | |
1033 | INIT_WORK(&info->work, blkif_restart_queue); | |
1034 | ||
1035 | for (i = 0; i < BLK_RING_SIZE; i++) | |
97e36834 KRW |
1036 | info->shadow[i].req.u.rw.id = i+1; |
1037 | info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff; | |
9f27ee59 JF |
1038 | |
1039 | /* Front end dir is a number, which is used as the id. */ | |
1040 | info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); | |
a1b4b12b | 1041 | dev_set_drvdata(&dev->dev, info); |
9f27ee59 | 1042 | |
203fd61f | 1043 | err = talk_to_blkback(dev, info); |
9f27ee59 JF |
1044 | if (err) { |
1045 | kfree(info); | |
a1b4b12b | 1046 | dev_set_drvdata(&dev->dev, NULL); |
9f27ee59 JF |
1047 | return err; |
1048 | } | |
1049 | ||
1050 | return 0; | |
1051 | } | |
1052 | ||
1053 | ||
1054 | static int blkif_recover(struct blkfront_info *info) | |
1055 | { | |
1056 | int i; | |
1057 | struct blkif_request *req; | |
1058 | struct blk_shadow *copy; | |
1059 | int j; | |
1060 | ||
1061 | /* Stage 1: Make a safe copy of the shadow state. */ | |
a144ff09 IC |
1062 | copy = kmalloc(sizeof(info->shadow), |
1063 | GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); | |
9f27ee59 JF |
1064 | if (!copy) |
1065 | return -ENOMEM; | |
1066 | memcpy(copy, info->shadow, sizeof(info->shadow)); | |
1067 | ||
1068 | /* Stage 2: Set up free list. */ | |
1069 | memset(&info->shadow, 0, sizeof(info->shadow)); | |
1070 | for (i = 0; i < BLK_RING_SIZE; i++) | |
97e36834 | 1071 | info->shadow[i].req.u.rw.id = i+1; |
9f27ee59 | 1072 | info->shadow_free = info->ring.req_prod_pvt; |
97e36834 | 1073 | info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff; |
9f27ee59 JF |
1074 | |
1075 | /* Stage 3: Find pending requests and requeue them. */ | |
1076 | for (i = 0; i < BLK_RING_SIZE; i++) { | |
1077 | /* Not in use? */ | |
a945b980 | 1078 | if (!copy[i].request) |
9f27ee59 JF |
1079 | continue; |
1080 | ||
1081 | /* Grab a request slot and copy shadow state into it. */ | |
1082 | req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
1083 | *req = copy[i].req; | |
1084 | ||
1085 | /* We get a new request id, and must reset the shadow state. */ | |
97e36834 KRW |
1086 | req->u.rw.id = get_id_from_freelist(info); |
1087 | memcpy(&info->shadow[req->u.rw.id], ©[i], sizeof(copy[i])); | |
9f27ee59 | 1088 | |
5ea42986 | 1089 | if (req->operation != BLKIF_OP_DISCARD) { |
9f27ee59 | 1090 | /* Rewrite any grant references invalidated by susp/resume. */ |
5ea42986 KRW |
1091 | for (j = 0; j < req->u.rw.nr_segments; j++) |
1092 | gnttab_grant_foreign_access_ref( | |
1093 | req->u.rw.seg[j].gref, | |
1094 | info->xbdev->otherend_id, | |
1095 | pfn_to_mfn(info->shadow[req->u.rw.id].frame[j]), | |
1096 | rq_data_dir(info->shadow[req->u.rw.id].request)); | |
1097 | } | |
97e36834 | 1098 | info->shadow[req->u.rw.id].req = *req; |
9f27ee59 JF |
1099 | |
1100 | info->ring.req_prod_pvt++; | |
1101 | } | |
1102 | ||
1103 | kfree(copy); | |
1104 | ||
1105 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1106 | ||
3467811e | 1107 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1108 | |
1109 | /* Now safe for us to use the shared ring */ | |
1110 | info->connected = BLKIF_STATE_CONNECTED; | |
1111 | ||
1112 | /* Send off requeued requests */ | |
1113 | flush_requests(info); | |
1114 | ||
1115 | /* Kick any other new requests queued since we resumed */ | |
1116 | kick_pending_request_queues(info); | |
1117 | ||
3467811e | 1118 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1119 | |
1120 | return 0; | |
1121 | } | |
1122 | ||
1123 | /** | |
1124 | * We are reconnecting to the backend, due to a suspend/resume, or a backend | |
1125 | * driver restart. We tear down our blkif structure and recreate it, but | |
1126 | * leave the device-layer structures intact so that this is transparent to the | |
1127 | * rest of the kernel. | |
1128 | */ | |
1129 | static int blkfront_resume(struct xenbus_device *dev) | |
1130 | { | |
a1b4b12b | 1131 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 JF |
1132 | int err; |
1133 | ||
1134 | dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename); | |
1135 | ||
1136 | blkif_free(info, info->connected == BLKIF_STATE_CONNECTED); | |
1137 | ||
203fd61f | 1138 | err = talk_to_blkback(dev, info); |
9f27ee59 JF |
1139 | if (info->connected == BLKIF_STATE_SUSPENDED && !err) |
1140 | err = blkif_recover(info); | |
1141 | ||
1142 | return err; | |
1143 | } | |
1144 | ||
b70f5fa0 DS |
1145 | static void |
1146 | blkfront_closing(struct blkfront_info *info) | |
1147 | { | |
1148 | struct xenbus_device *xbdev = info->xbdev; | |
1149 | struct block_device *bdev = NULL; | |
1150 | ||
1151 | mutex_lock(&info->mutex); | |
1152 | ||
1153 | if (xbdev->state == XenbusStateClosing) { | |
1154 | mutex_unlock(&info->mutex); | |
1155 | return; | |
1156 | } | |
1157 | ||
1158 | if (info->gd) | |
1159 | bdev = bdget_disk(info->gd, 0); | |
1160 | ||
1161 | mutex_unlock(&info->mutex); | |
1162 | ||
1163 | if (!bdev) { | |
1164 | xenbus_frontend_closed(xbdev); | |
1165 | return; | |
1166 | } | |
1167 | ||
1168 | mutex_lock(&bdev->bd_mutex); | |
1169 | ||
7b32d104 | 1170 | if (bdev->bd_openers) { |
b70f5fa0 DS |
1171 | xenbus_dev_error(xbdev, -EBUSY, |
1172 | "Device in use; refusing to close"); | |
1173 | xenbus_switch_state(xbdev, XenbusStateClosing); | |
1174 | } else { | |
1175 | xlvbd_release_gendisk(info); | |
1176 | xenbus_frontend_closed(xbdev); | |
1177 | } | |
1178 | ||
1179 | mutex_unlock(&bdev->bd_mutex); | |
1180 | bdput(bdev); | |
1181 | } | |
9f27ee59 | 1182 | |
ed30bf31 LD |
1183 | static void blkfront_setup_discard(struct blkfront_info *info) |
1184 | { | |
1185 | int err; | |
1186 | char *type; | |
1187 | unsigned int discard_granularity; | |
1188 | unsigned int discard_alignment; | |
5ea42986 | 1189 | unsigned int discard_secure; |
ed30bf31 LD |
1190 | |
1191 | type = xenbus_read(XBT_NIL, info->xbdev->otherend, "type", NULL); | |
1192 | if (IS_ERR(type)) | |
1193 | return; | |
1194 | ||
5ea42986 | 1195 | info->feature_secdiscard = 0; |
ed30bf31 LD |
1196 | if (strncmp(type, "phy", 3) == 0) { |
1197 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1198 | "discard-granularity", "%u", &discard_granularity, | |
1199 | "discard-alignment", "%u", &discard_alignment, | |
1200 | NULL); | |
1201 | if (!err) { | |
1202 | info->feature_discard = 1; | |
1203 | info->discard_granularity = discard_granularity; | |
1204 | info->discard_alignment = discard_alignment; | |
1205 | } | |
5ea42986 KRW |
1206 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, |
1207 | "discard-secure", "%d", &discard_secure, | |
1208 | NULL); | |
1209 | if (!err) | |
1210 | info->feature_secdiscard = discard_secure; | |
1211 | ||
ed30bf31 LD |
1212 | } else if (strncmp(type, "file", 4) == 0) |
1213 | info->feature_discard = 1; | |
1214 | ||
1215 | kfree(type); | |
1216 | } | |
1217 | ||
9f27ee59 JF |
1218 | /* |
1219 | * Invoked when the backend is finally 'ready' (and has told produced | |
1220 | * the details about the physical device - #sectors, size, etc). | |
1221 | */ | |
1222 | static void blkfront_connect(struct blkfront_info *info) | |
1223 | { | |
1224 | unsigned long long sectors; | |
1225 | unsigned long sector_size; | |
1226 | unsigned int binfo; | |
1227 | int err; | |
ed30bf31 | 1228 | int barrier, flush, discard; |
9f27ee59 | 1229 | |
1fa73be6 S |
1230 | switch (info->connected) { |
1231 | case BLKIF_STATE_CONNECTED: | |
1232 | /* | |
1233 | * Potentially, the back-end may be signalling | |
1234 | * a capacity change; update the capacity. | |
1235 | */ | |
1236 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1237 | "sectors", "%Lu", §ors); | |
1238 | if (XENBUS_EXIST_ERR(err)) | |
1239 | return; | |
1240 | printk(KERN_INFO "Setting capacity to %Lu\n", | |
1241 | sectors); | |
1242 | set_capacity(info->gd, sectors); | |
2def141e | 1243 | revalidate_disk(info->gd); |
1fa73be6 S |
1244 | |
1245 | /* fall through */ | |
1246 | case BLKIF_STATE_SUSPENDED: | |
9f27ee59 JF |
1247 | return; |
1248 | ||
b4dddb49 JF |
1249 | default: |
1250 | break; | |
1fa73be6 | 1251 | } |
9f27ee59 JF |
1252 | |
1253 | dev_dbg(&info->xbdev->dev, "%s:%s.\n", | |
1254 | __func__, info->xbdev->otherend); | |
1255 | ||
1256 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1257 | "sectors", "%llu", §ors, | |
1258 | "info", "%u", &binfo, | |
1259 | "sector-size", "%lu", §or_size, | |
1260 | NULL); | |
1261 | if (err) { | |
1262 | xenbus_dev_fatal(info->xbdev, err, | |
1263 | "reading backend fields at %s", | |
1264 | info->xbdev->otherend); | |
1265 | return; | |
1266 | } | |
1267 | ||
edf6ef59 KRW |
1268 | info->feature_flush = 0; |
1269 | info->flush_op = 0; | |
1270 | ||
9f27ee59 | 1271 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, |
4352b47a | 1272 | "feature-barrier", "%d", &barrier, |
9f27ee59 | 1273 | NULL); |
7901d141 JF |
1274 | |
1275 | /* | |
1276 | * If there's no "feature-barrier" defined, then it means | |
1277 | * we're dealing with a very old backend which writes | |
4913efe4 | 1278 | * synchronously; nothing to do. |
7901d141 | 1279 | * |
6958f145 | 1280 | * If there are barriers, then we use flush. |
7901d141 | 1281 | */ |
edf6ef59 | 1282 | if (!err && barrier) { |
be2f8373 | 1283 | info->feature_flush = REQ_FLUSH | REQ_FUA; |
edf6ef59 KRW |
1284 | info->flush_op = BLKIF_OP_WRITE_BARRIER; |
1285 | } | |
1286 | /* | |
1287 | * And if there is "feature-flush-cache" use that above | |
1288 | * barriers. | |
1289 | */ | |
1290 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1291 | "feature-flush-cache", "%d", &flush, | |
1292 | NULL); | |
9f27ee59 | 1293 | |
edf6ef59 KRW |
1294 | if (!err && flush) { |
1295 | info->feature_flush = REQ_FLUSH; | |
1296 | info->flush_op = BLKIF_OP_FLUSH_DISKCACHE; | |
1297 | } | |
ed30bf31 LD |
1298 | |
1299 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1300 | "feature-discard", "%d", &discard, | |
1301 | NULL); | |
1302 | ||
1303 | if (!err && discard) | |
1304 | blkfront_setup_discard(info); | |
1305 | ||
9246b5f0 | 1306 | err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size); |
9f27ee59 JF |
1307 | if (err) { |
1308 | xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", | |
1309 | info->xbdev->otherend); | |
1310 | return; | |
1311 | } | |
1312 | ||
1313 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1314 | ||
1315 | /* Kick pending requests. */ | |
3467811e | 1316 | spin_lock_irq(&info->io_lock); |
9f27ee59 JF |
1317 | info->connected = BLKIF_STATE_CONNECTED; |
1318 | kick_pending_request_queues(info); | |
3467811e | 1319 | spin_unlock_irq(&info->io_lock); |
9f27ee59 JF |
1320 | |
1321 | add_disk(info->gd); | |
1d78d705 CL |
1322 | |
1323 | info->is_ready = 1; | |
9f27ee59 JF |
1324 | } |
1325 | ||
9f27ee59 JF |
1326 | /** |
1327 | * Callback received when the backend's state changes. | |
1328 | */ | |
203fd61f | 1329 | static void blkback_changed(struct xenbus_device *dev, |
9f27ee59 JF |
1330 | enum xenbus_state backend_state) |
1331 | { | |
a1b4b12b | 1332 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 | 1333 | |
203fd61f | 1334 | dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); |
9f27ee59 JF |
1335 | |
1336 | switch (backend_state) { | |
1337 | case XenbusStateInitialising: | |
1338 | case XenbusStateInitWait: | |
1339 | case XenbusStateInitialised: | |
b78c9512 NI |
1340 | case XenbusStateReconfiguring: |
1341 | case XenbusStateReconfigured: | |
9f27ee59 JF |
1342 | case XenbusStateUnknown: |
1343 | case XenbusStateClosed: | |
1344 | break; | |
1345 | ||
1346 | case XenbusStateConnected: | |
1347 | blkfront_connect(info); | |
1348 | break; | |
1349 | ||
1350 | case XenbusStateClosing: | |
b70f5fa0 | 1351 | blkfront_closing(info); |
9f27ee59 JF |
1352 | break; |
1353 | } | |
1354 | } | |
1355 | ||
fa1bd359 | 1356 | static int blkfront_remove(struct xenbus_device *xbdev) |
9f27ee59 | 1357 | { |
fa1bd359 DS |
1358 | struct blkfront_info *info = dev_get_drvdata(&xbdev->dev); |
1359 | struct block_device *bdev = NULL; | |
1360 | struct gendisk *disk; | |
9f27ee59 | 1361 | |
fa1bd359 | 1362 | dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename); |
9f27ee59 JF |
1363 | |
1364 | blkif_free(info, 0); | |
1365 | ||
fa1bd359 DS |
1366 | mutex_lock(&info->mutex); |
1367 | ||
1368 | disk = info->gd; | |
1369 | if (disk) | |
1370 | bdev = bdget_disk(disk, 0); | |
1371 | ||
1372 | info->xbdev = NULL; | |
1373 | mutex_unlock(&info->mutex); | |
1374 | ||
1375 | if (!bdev) { | |
1376 | kfree(info); | |
1377 | return 0; | |
1378 | } | |
1379 | ||
1380 | /* | |
1381 | * The xbdev was removed before we reached the Closed | |
1382 | * state. See if it's safe to remove the disk. If the bdev | |
1383 | * isn't closed yet, we let release take care of it. | |
1384 | */ | |
1385 | ||
1386 | mutex_lock(&bdev->bd_mutex); | |
1387 | info = disk->private_data; | |
1388 | ||
d54142c7 DS |
1389 | dev_warn(disk_to_dev(disk), |
1390 | "%s was hot-unplugged, %d stale handles\n", | |
1391 | xbdev->nodename, bdev->bd_openers); | |
1392 | ||
7b32d104 | 1393 | if (info && !bdev->bd_openers) { |
fa1bd359 DS |
1394 | xlvbd_release_gendisk(info); |
1395 | disk->private_data = NULL; | |
0e345826 | 1396 | kfree(info); |
fa1bd359 DS |
1397 | } |
1398 | ||
1399 | mutex_unlock(&bdev->bd_mutex); | |
1400 | bdput(bdev); | |
9f27ee59 JF |
1401 | |
1402 | return 0; | |
1403 | } | |
1404 | ||
1d78d705 CL |
1405 | static int blkfront_is_ready(struct xenbus_device *dev) |
1406 | { | |
a1b4b12b | 1407 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
1d78d705 | 1408 | |
5d7ed20e | 1409 | return info->is_ready && info->xbdev; |
1d78d705 CL |
1410 | } |
1411 | ||
a63c848b | 1412 | static int blkif_open(struct block_device *bdev, fmode_t mode) |
9f27ee59 | 1413 | { |
13961743 DS |
1414 | struct gendisk *disk = bdev->bd_disk; |
1415 | struct blkfront_info *info; | |
1416 | int err = 0; | |
6e9624b8 | 1417 | |
2a48fc0a | 1418 | mutex_lock(&blkfront_mutex); |
6e9624b8 | 1419 | |
13961743 DS |
1420 | info = disk->private_data; |
1421 | if (!info) { | |
1422 | /* xbdev gone */ | |
1423 | err = -ERESTARTSYS; | |
1424 | goto out; | |
1425 | } | |
1426 | ||
1427 | mutex_lock(&info->mutex); | |
1428 | ||
1429 | if (!info->gd) | |
1430 | /* xbdev is closed */ | |
1431 | err = -ERESTARTSYS; | |
1432 | ||
1433 | mutex_unlock(&info->mutex); | |
1434 | ||
13961743 | 1435 | out: |
2a48fc0a | 1436 | mutex_unlock(&blkfront_mutex); |
13961743 | 1437 | return err; |
9f27ee59 JF |
1438 | } |
1439 | ||
a63c848b | 1440 | static int blkif_release(struct gendisk *disk, fmode_t mode) |
9f27ee59 | 1441 | { |
a63c848b | 1442 | struct blkfront_info *info = disk->private_data; |
7fd152f4 DS |
1443 | struct block_device *bdev; |
1444 | struct xenbus_device *xbdev; | |
1445 | ||
2a48fc0a | 1446 | mutex_lock(&blkfront_mutex); |
7fd152f4 DS |
1447 | |
1448 | bdev = bdget_disk(disk, 0); | |
7fd152f4 | 1449 | |
acfca3c6 DS |
1450 | if (bdev->bd_openers) |
1451 | goto out; | |
1452 | ||
7fd152f4 DS |
1453 | /* |
1454 | * Check if we have been instructed to close. We will have | |
1455 | * deferred this request, because the bdev was still open. | |
1456 | */ | |
1457 | ||
1458 | mutex_lock(&info->mutex); | |
1459 | xbdev = info->xbdev; | |
1460 | ||
1461 | if (xbdev && xbdev->state == XenbusStateClosing) { | |
1462 | /* pending switch to state closed */ | |
d54142c7 | 1463 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
1464 | xlvbd_release_gendisk(info); |
1465 | xenbus_frontend_closed(info->xbdev); | |
1466 | } | |
1467 | ||
1468 | mutex_unlock(&info->mutex); | |
1469 | ||
1470 | if (!xbdev) { | |
1471 | /* sudden device removal */ | |
d54142c7 | 1472 | dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n"); |
7fd152f4 DS |
1473 | xlvbd_release_gendisk(info); |
1474 | disk->private_data = NULL; | |
1475 | kfree(info); | |
9f27ee59 | 1476 | } |
7fd152f4 | 1477 | |
a4cc14ec | 1478 | out: |
dad5cf65 | 1479 | bdput(bdev); |
2a48fc0a | 1480 | mutex_unlock(&blkfront_mutex); |
9f27ee59 JF |
1481 | return 0; |
1482 | } | |
1483 | ||
83d5cde4 | 1484 | static const struct block_device_operations xlvbd_block_fops = |
9f27ee59 JF |
1485 | { |
1486 | .owner = THIS_MODULE, | |
a63c848b AV |
1487 | .open = blkif_open, |
1488 | .release = blkif_release, | |
597592d9 | 1489 | .getgeo = blkif_getgeo, |
8a6cfeb6 | 1490 | .ioctl = blkif_ioctl, |
9f27ee59 JF |
1491 | }; |
1492 | ||
1493 | ||
ec9c42ec | 1494 | static const struct xenbus_device_id blkfront_ids[] = { |
9f27ee59 JF |
1495 | { "vbd" }, |
1496 | { "" } | |
1497 | }; | |
1498 | ||
73db144b | 1499 | static DEFINE_XENBUS_DRIVER(blkfront, , |
9f27ee59 JF |
1500 | .probe = blkfront_probe, |
1501 | .remove = blkfront_remove, | |
1502 | .resume = blkfront_resume, | |
203fd61f | 1503 | .otherend_changed = blkback_changed, |
1d78d705 | 1504 | .is_ready = blkfront_is_ready, |
73db144b | 1505 | ); |
9f27ee59 JF |
1506 | |
1507 | static int __init xlblk_init(void) | |
1508 | { | |
469738e6 LE |
1509 | int ret; |
1510 | ||
6e833587 | 1511 | if (!xen_domain()) |
9f27ee59 JF |
1512 | return -ENODEV; |
1513 | ||
e95ae5a4 | 1514 | if (xen_hvm_domain() && !xen_platform_pci_unplug) |
b9136d20 IM |
1515 | return -ENODEV; |
1516 | ||
9f27ee59 JF |
1517 | if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { |
1518 | printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", | |
1519 | XENVBD_MAJOR, DEV_NAME); | |
1520 | return -ENODEV; | |
1521 | } | |
1522 | ||
73db144b | 1523 | ret = xenbus_register_frontend(&blkfront_driver); |
469738e6 LE |
1524 | if (ret) { |
1525 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
1526 | return ret; | |
1527 | } | |
1528 | ||
1529 | return 0; | |
9f27ee59 JF |
1530 | } |
1531 | module_init(xlblk_init); | |
1532 | ||
1533 | ||
5a60d0cd | 1534 | static void __exit xlblk_exit(void) |
9f27ee59 | 1535 | { |
8605067f JB |
1536 | xenbus_unregister_driver(&blkfront_driver); |
1537 | unregister_blkdev(XENVBD_MAJOR, DEV_NAME); | |
1538 | kfree(minors); | |
9f27ee59 JF |
1539 | } |
1540 | module_exit(xlblk_exit); | |
1541 | ||
1542 | MODULE_DESCRIPTION("Xen virtual block device frontend"); | |
1543 | MODULE_LICENSE("GPL"); | |
1544 | MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR); | |
d2f0c52b | 1545 | MODULE_ALIAS("xen:vbd"); |
4f93f09b | 1546 | MODULE_ALIAS("xenblk"); |