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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> |
6e9624b8 | 44 | #include <linux/smp_lock.h> |
9e973e64 | 45 | #include <linux/scatterlist.h> |
9f27ee59 | 46 | |
1ccbf534 | 47 | #include <xen/xen.h> |
9f27ee59 JF |
48 | #include <xen/xenbus.h> |
49 | #include <xen/grant_table.h> | |
50 | #include <xen/events.h> | |
51 | #include <xen/page.h> | |
52 | ||
53 | #include <xen/interface/grant_table.h> | |
54 | #include <xen/interface/io/blkif.h> | |
3e334239 | 55 | #include <xen/interface/io/protocols.h> |
9f27ee59 JF |
56 | |
57 | #include <asm/xen/hypervisor.h> | |
58 | ||
59 | enum blkif_state { | |
60 | BLKIF_STATE_DISCONNECTED, | |
61 | BLKIF_STATE_CONNECTED, | |
62 | BLKIF_STATE_SUSPENDED, | |
63 | }; | |
64 | ||
65 | struct blk_shadow { | |
66 | struct blkif_request req; | |
67 | unsigned long request; | |
68 | unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST]; | |
69 | }; | |
70 | ||
83d5cde4 | 71 | static const struct block_device_operations xlvbd_block_fops; |
9f27ee59 JF |
72 | |
73 | #define BLK_RING_SIZE __RING_SIZE((struct blkif_sring *)0, PAGE_SIZE) | |
74 | ||
75 | /* | |
76 | * We have one of these per vbd, whether ide, scsi or 'other'. They | |
77 | * hang in private_data off the gendisk structure. We may end up | |
78 | * putting all kinds of interesting stuff here :-) | |
79 | */ | |
80 | struct blkfront_info | |
81 | { | |
b70f5fa0 | 82 | struct mutex mutex; |
9f27ee59 | 83 | struct xenbus_device *xbdev; |
9f27ee59 JF |
84 | struct gendisk *gd; |
85 | int vdevice; | |
86 | blkif_vdev_t handle; | |
87 | enum blkif_state connected; | |
88 | int ring_ref; | |
89 | struct blkif_front_ring ring; | |
9e973e64 | 90 | struct scatterlist sg[BLKIF_MAX_SEGMENTS_PER_REQUEST]; |
9f27ee59 JF |
91 | unsigned int evtchn, irq; |
92 | struct request_queue *rq; | |
93 | struct work_struct work; | |
94 | struct gnttab_free_callback callback; | |
95 | struct blk_shadow shadow[BLK_RING_SIZE]; | |
96 | unsigned long shadow_free; | |
97 | int feature_barrier; | |
1d78d705 | 98 | int is_ready; |
9f27ee59 JF |
99 | |
100 | /** | |
101 | * The number of people holding this device open. We won't allow a | |
102 | * hot-unplug unless this is 0. | |
103 | */ | |
104 | int users; | |
105 | }; | |
106 | ||
107 | static DEFINE_SPINLOCK(blkif_io_lock); | |
108 | ||
0e345826 JB |
109 | static unsigned int nr_minors; |
110 | static unsigned long *minors; | |
111 | static DEFINE_SPINLOCK(minor_lock); | |
112 | ||
9f27ee59 JF |
113 | #define MAXIMUM_OUTSTANDING_BLOCK_REQS \ |
114 | (BLKIF_MAX_SEGMENTS_PER_REQUEST * BLK_RING_SIZE) | |
115 | #define GRANT_INVALID_REF 0 | |
116 | ||
117 | #define PARTS_PER_DISK 16 | |
9246b5f0 | 118 | #define PARTS_PER_EXT_DISK 256 |
9f27ee59 JF |
119 | |
120 | #define BLKIF_MAJOR(dev) ((dev)>>8) | |
121 | #define BLKIF_MINOR(dev) ((dev) & 0xff) | |
122 | ||
9246b5f0 CL |
123 | #define EXT_SHIFT 28 |
124 | #define EXTENDED (1<<EXT_SHIFT) | |
125 | #define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED)) | |
126 | #define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED)) | |
9f27ee59 | 127 | |
9246b5f0 | 128 | #define DEV_NAME "xvd" /* name in /dev */ |
9f27ee59 JF |
129 | |
130 | static int get_id_from_freelist(struct blkfront_info *info) | |
131 | { | |
132 | unsigned long free = info->shadow_free; | |
b9ed7252 | 133 | BUG_ON(free >= BLK_RING_SIZE); |
9f27ee59 JF |
134 | info->shadow_free = info->shadow[free].req.id; |
135 | info->shadow[free].req.id = 0x0fffffee; /* debug */ | |
136 | return free; | |
137 | } | |
138 | ||
139 | static void add_id_to_freelist(struct blkfront_info *info, | |
140 | unsigned long id) | |
141 | { | |
142 | info->shadow[id].req.id = info->shadow_free; | |
143 | info->shadow[id].request = 0; | |
144 | info->shadow_free = id; | |
145 | } | |
146 | ||
0e345826 JB |
147 | static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) |
148 | { | |
149 | unsigned int end = minor + nr; | |
150 | int rc; | |
151 | ||
152 | if (end > nr_minors) { | |
153 | unsigned long *bitmap, *old; | |
154 | ||
155 | bitmap = kzalloc(BITS_TO_LONGS(end) * sizeof(*bitmap), | |
156 | GFP_KERNEL); | |
157 | if (bitmap == NULL) | |
158 | return -ENOMEM; | |
159 | ||
160 | spin_lock(&minor_lock); | |
161 | if (end > nr_minors) { | |
162 | old = minors; | |
163 | memcpy(bitmap, minors, | |
164 | BITS_TO_LONGS(nr_minors) * sizeof(*bitmap)); | |
165 | minors = bitmap; | |
166 | nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG; | |
167 | } else | |
168 | old = bitmap; | |
169 | spin_unlock(&minor_lock); | |
170 | kfree(old); | |
171 | } | |
172 | ||
173 | spin_lock(&minor_lock); | |
174 | if (find_next_bit(minors, end, minor) >= end) { | |
175 | for (; minor < end; ++minor) | |
176 | __set_bit(minor, minors); | |
177 | rc = 0; | |
178 | } else | |
179 | rc = -EBUSY; | |
180 | spin_unlock(&minor_lock); | |
181 | ||
182 | return rc; | |
183 | } | |
184 | ||
185 | static void xlbd_release_minors(unsigned int minor, unsigned int nr) | |
186 | { | |
187 | unsigned int end = minor + nr; | |
188 | ||
189 | BUG_ON(end > nr_minors); | |
190 | spin_lock(&minor_lock); | |
191 | for (; minor < end; ++minor) | |
192 | __clear_bit(minor, minors); | |
193 | spin_unlock(&minor_lock); | |
194 | } | |
195 | ||
9f27ee59 JF |
196 | static void blkif_restart_queue_callback(void *arg) |
197 | { | |
198 | struct blkfront_info *info = (struct blkfront_info *)arg; | |
199 | schedule_work(&info->work); | |
200 | } | |
201 | ||
afe42d7d | 202 | static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg) |
597592d9 IC |
203 | { |
204 | /* We don't have real geometry info, but let's at least return | |
205 | values consistent with the size of the device */ | |
206 | sector_t nsect = get_capacity(bd->bd_disk); | |
207 | sector_t cylinders = nsect; | |
208 | ||
209 | hg->heads = 0xff; | |
210 | hg->sectors = 0x3f; | |
211 | sector_div(cylinders, hg->heads * hg->sectors); | |
212 | hg->cylinders = cylinders; | |
213 | if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect) | |
214 | hg->cylinders = 0xffff; | |
215 | return 0; | |
216 | } | |
217 | ||
a63c848b | 218 | static int blkif_ioctl(struct block_device *bdev, fmode_t mode, |
62aa0054 | 219 | unsigned command, unsigned long argument) |
440a01a7 | 220 | { |
a63c848b | 221 | struct blkfront_info *info = bdev->bd_disk->private_data; |
440a01a7 CL |
222 | int i; |
223 | ||
224 | dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n", | |
225 | command, (long)argument); | |
226 | ||
227 | switch (command) { | |
228 | case CDROMMULTISESSION: | |
229 | dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n"); | |
230 | for (i = 0; i < sizeof(struct cdrom_multisession); i++) | |
231 | if (put_user(0, (char __user *)(argument + i))) | |
232 | return -EFAULT; | |
233 | return 0; | |
234 | ||
235 | case CDROM_GET_CAPABILITY: { | |
236 | struct gendisk *gd = info->gd; | |
237 | if (gd->flags & GENHD_FL_CD) | |
238 | return 0; | |
239 | return -EINVAL; | |
240 | } | |
241 | ||
242 | default: | |
243 | /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n", | |
244 | command);*/ | |
245 | return -EINVAL; /* same return as native Linux */ | |
246 | } | |
247 | ||
248 | return 0; | |
249 | } | |
250 | ||
9f27ee59 JF |
251 | /* |
252 | * blkif_queue_request | |
253 | * | |
254 | * request block io | |
255 | * | |
256 | * id: for guest use only. | |
257 | * operation: BLKIF_OP_{READ,WRITE,PROBE} | |
258 | * buffer: buffer to read/write into. this should be a | |
259 | * virtual address in the guest os. | |
260 | */ | |
261 | static int blkif_queue_request(struct request *req) | |
262 | { | |
263 | struct blkfront_info *info = req->rq_disk->private_data; | |
264 | unsigned long buffer_mfn; | |
265 | struct blkif_request *ring_req; | |
9f27ee59 JF |
266 | unsigned long id; |
267 | unsigned int fsect, lsect; | |
9e973e64 | 268 | int i, ref; |
9f27ee59 | 269 | grant_ref_t gref_head; |
9e973e64 | 270 | struct scatterlist *sg; |
9f27ee59 JF |
271 | |
272 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) | |
273 | return 1; | |
274 | ||
275 | if (gnttab_alloc_grant_references( | |
276 | BLKIF_MAX_SEGMENTS_PER_REQUEST, &gref_head) < 0) { | |
277 | gnttab_request_free_callback( | |
278 | &info->callback, | |
279 | blkif_restart_queue_callback, | |
280 | info, | |
281 | BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
282 | return 1; | |
283 | } | |
284 | ||
285 | /* Fill out a communications ring structure. */ | |
286 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
287 | id = get_id_from_freelist(info); | |
288 | info->shadow[id].request = (unsigned long)req; | |
289 | ||
290 | ring_req->id = id; | |
83096ebf | 291 | ring_req->sector_number = (blkif_sector_t)blk_rq_pos(req); |
9f27ee59 JF |
292 | ring_req->handle = info->handle; |
293 | ||
294 | ring_req->operation = rq_data_dir(req) ? | |
295 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
33659ebb | 296 | if (req->cmd_flags & REQ_HARDBARRIER) |
9f27ee59 JF |
297 | ring_req->operation = BLKIF_OP_WRITE_BARRIER; |
298 | ||
9e973e64 JA |
299 | ring_req->nr_segments = blk_rq_map_sg(req->q, req, info->sg); |
300 | BUG_ON(ring_req->nr_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
301 | ||
302 | for_each_sg(info->sg, sg, ring_req->nr_segments, i) { | |
303 | buffer_mfn = pfn_to_mfn(page_to_pfn(sg_page(sg))); | |
304 | fsect = sg->offset >> 9; | |
305 | lsect = fsect + (sg->length >> 9) - 1; | |
6c92e699 JA |
306 | /* install a grant reference. */ |
307 | ref = gnttab_claim_grant_reference(&gref_head); | |
308 | BUG_ON(ref == -ENOSPC); | |
309 | ||
310 | gnttab_grant_foreign_access_ref( | |
9f27ee59 JF |
311 | ref, |
312 | info->xbdev->otherend_id, | |
313 | buffer_mfn, | |
314 | rq_data_dir(req) ); | |
315 | ||
9e973e64 JA |
316 | info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn); |
317 | ring_req->seg[i] = | |
9f27ee59 JF |
318 | (struct blkif_request_segment) { |
319 | .gref = ref, | |
320 | .first_sect = fsect, | |
321 | .last_sect = lsect }; | |
9f27ee59 JF |
322 | } |
323 | ||
324 | info->ring.req_prod_pvt++; | |
325 | ||
326 | /* Keep a private copy so we can reissue requests when recovering. */ | |
327 | info->shadow[id].req = *ring_req; | |
328 | ||
329 | gnttab_free_grant_references(gref_head); | |
330 | ||
331 | return 0; | |
332 | } | |
333 | ||
334 | ||
335 | static inline void flush_requests(struct blkfront_info *info) | |
336 | { | |
337 | int notify; | |
338 | ||
339 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify); | |
340 | ||
341 | if (notify) | |
342 | notify_remote_via_irq(info->irq); | |
343 | } | |
344 | ||
345 | /* | |
346 | * do_blkif_request | |
347 | * read a block; request is in a request queue | |
348 | */ | |
165125e1 | 349 | static void do_blkif_request(struct request_queue *rq) |
9f27ee59 JF |
350 | { |
351 | struct blkfront_info *info = NULL; | |
352 | struct request *req; | |
353 | int queued; | |
354 | ||
355 | pr_debug("Entered do_blkif_request\n"); | |
356 | ||
357 | queued = 0; | |
358 | ||
9934c8c0 | 359 | while ((req = blk_peek_request(rq)) != NULL) { |
9f27ee59 | 360 | info = req->rq_disk->private_data; |
9f27ee59 JF |
361 | |
362 | if (RING_FULL(&info->ring)) | |
363 | goto wait; | |
364 | ||
9934c8c0 | 365 | blk_start_request(req); |
296b2f6a | 366 | |
33659ebb | 367 | if (req->cmd_type != REQ_TYPE_FS) { |
296b2f6a TH |
368 | __blk_end_request_all(req, -EIO); |
369 | continue; | |
370 | } | |
371 | ||
9f27ee59 | 372 | pr_debug("do_blk_req %p: cmd %p, sec %lx, " |
83096ebf TH |
373 | "(%u/%u) buffer:%p [%s]\n", |
374 | req, req->cmd, (unsigned long)blk_rq_pos(req), | |
375 | blk_rq_cur_sectors(req), blk_rq_sectors(req), | |
376 | req->buffer, rq_data_dir(req) ? "write" : "read"); | |
9f27ee59 | 377 | |
9f27ee59 JF |
378 | if (blkif_queue_request(req)) { |
379 | blk_requeue_request(rq, req); | |
380 | wait: | |
381 | /* Avoid pointless unplugs. */ | |
382 | blk_stop_queue(rq); | |
383 | break; | |
384 | } | |
385 | ||
386 | queued++; | |
387 | } | |
388 | ||
389 | if (queued != 0) | |
390 | flush_requests(info); | |
391 | } | |
392 | ||
393 | static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size) | |
394 | { | |
165125e1 | 395 | struct request_queue *rq; |
9f27ee59 JF |
396 | |
397 | rq = blk_init_queue(do_blkif_request, &blkif_io_lock); | |
398 | if (rq == NULL) | |
399 | return -1; | |
400 | ||
66d352e1 | 401 | queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); |
9f27ee59 JF |
402 | |
403 | /* Hard sector size and max sectors impersonate the equiv. hardware. */ | |
e1defc4f | 404 | blk_queue_logical_block_size(rq, sector_size); |
086fa5ff | 405 | blk_queue_max_hw_sectors(rq, 512); |
9f27ee59 JF |
406 | |
407 | /* Each segment in a request is up to an aligned page in size. */ | |
408 | blk_queue_segment_boundary(rq, PAGE_SIZE - 1); | |
409 | blk_queue_max_segment_size(rq, PAGE_SIZE); | |
410 | ||
411 | /* Ensure a merged request will fit in a single I/O ring slot. */ | |
8a78362c | 412 | blk_queue_max_segments(rq, BLKIF_MAX_SEGMENTS_PER_REQUEST); |
9f27ee59 JF |
413 | |
414 | /* Make sure buffer addresses are sector-aligned. */ | |
415 | blk_queue_dma_alignment(rq, 511); | |
416 | ||
1c91fe1a IC |
417 | /* Make sure we don't use bounce buffers. */ |
418 | blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY); | |
419 | ||
9f27ee59 JF |
420 | gd->queue = rq; |
421 | ||
422 | return 0; | |
423 | } | |
424 | ||
425 | ||
426 | static int xlvbd_barrier(struct blkfront_info *info) | |
427 | { | |
428 | int err; | |
429 | ||
430 | err = blk_queue_ordered(info->rq, | |
00fff265 | 431 | info->feature_barrier ? QUEUE_ORDERED_DRAIN : QUEUE_ORDERED_NONE); |
9f27ee59 JF |
432 | |
433 | if (err) | |
434 | return err; | |
435 | ||
436 | printk(KERN_INFO "blkfront: %s: barriers %s\n", | |
437 | info->gd->disk_name, | |
438 | info->feature_barrier ? "enabled" : "disabled"); | |
439 | return 0; | |
440 | } | |
441 | ||
442 | ||
9246b5f0 CL |
443 | static int xlvbd_alloc_gendisk(blkif_sector_t capacity, |
444 | struct blkfront_info *info, | |
445 | u16 vdisk_info, u16 sector_size) | |
9f27ee59 JF |
446 | { |
447 | struct gendisk *gd; | |
448 | int nr_minors = 1; | |
449 | int err = -ENODEV; | |
9246b5f0 CL |
450 | unsigned int offset; |
451 | int minor; | |
452 | int nr_parts; | |
9f27ee59 JF |
453 | |
454 | BUG_ON(info->gd != NULL); | |
455 | BUG_ON(info->rq != NULL); | |
456 | ||
9246b5f0 CL |
457 | if ((info->vdevice>>EXT_SHIFT) > 1) { |
458 | /* this is above the extended range; something is wrong */ | |
459 | printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice); | |
460 | return -ENODEV; | |
461 | } | |
462 | ||
463 | if (!VDEV_IS_EXTENDED(info->vdevice)) { | |
464 | minor = BLKIF_MINOR(info->vdevice); | |
465 | nr_parts = PARTS_PER_DISK; | |
466 | } else { | |
467 | minor = BLKIF_MINOR_EXT(info->vdevice); | |
468 | nr_parts = PARTS_PER_EXT_DISK; | |
469 | } | |
470 | ||
471 | if ((minor % nr_parts) == 0) | |
472 | nr_minors = nr_parts; | |
9f27ee59 | 473 | |
0e345826 JB |
474 | err = xlbd_reserve_minors(minor, nr_minors); |
475 | if (err) | |
476 | goto out; | |
477 | err = -ENODEV; | |
478 | ||
9f27ee59 JF |
479 | gd = alloc_disk(nr_minors); |
480 | if (gd == NULL) | |
0e345826 | 481 | goto release; |
9f27ee59 | 482 | |
9246b5f0 CL |
483 | offset = minor / nr_parts; |
484 | ||
485 | if (nr_minors > 1) { | |
486 | if (offset < 26) | |
487 | sprintf(gd->disk_name, "%s%c", DEV_NAME, 'a' + offset); | |
488 | else | |
489 | sprintf(gd->disk_name, "%s%c%c", DEV_NAME, | |
490 | 'a' + ((offset / 26)-1), 'a' + (offset % 26)); | |
491 | } else { | |
492 | if (offset < 26) | |
493 | sprintf(gd->disk_name, "%s%c%d", DEV_NAME, | |
494 | 'a' + offset, | |
495 | minor & (nr_parts - 1)); | |
496 | else | |
497 | sprintf(gd->disk_name, "%s%c%c%d", DEV_NAME, | |
498 | 'a' + ((offset / 26) - 1), | |
499 | 'a' + (offset % 26), | |
500 | minor & (nr_parts - 1)); | |
501 | } | |
9f27ee59 JF |
502 | |
503 | gd->major = XENVBD_MAJOR; | |
504 | gd->first_minor = minor; | |
505 | gd->fops = &xlvbd_block_fops; | |
506 | gd->private_data = info; | |
507 | gd->driverfs_dev = &(info->xbdev->dev); | |
508 | set_capacity(gd, capacity); | |
509 | ||
510 | if (xlvbd_init_blk_queue(gd, sector_size)) { | |
511 | del_gendisk(gd); | |
0e345826 | 512 | goto release; |
9f27ee59 JF |
513 | } |
514 | ||
515 | info->rq = gd->queue; | |
516 | info->gd = gd; | |
517 | ||
518 | if (info->feature_barrier) | |
519 | xlvbd_barrier(info); | |
520 | ||
521 | if (vdisk_info & VDISK_READONLY) | |
522 | set_disk_ro(gd, 1); | |
523 | ||
524 | if (vdisk_info & VDISK_REMOVABLE) | |
525 | gd->flags |= GENHD_FL_REMOVABLE; | |
526 | ||
527 | if (vdisk_info & VDISK_CDROM) | |
528 | gd->flags |= GENHD_FL_CD; | |
529 | ||
530 | return 0; | |
531 | ||
0e345826 JB |
532 | release: |
533 | xlbd_release_minors(minor, nr_minors); | |
9f27ee59 JF |
534 | out: |
535 | return err; | |
536 | } | |
537 | ||
a66b5aeb DS |
538 | static void xlvbd_release_gendisk(struct blkfront_info *info) |
539 | { | |
540 | unsigned int minor, nr_minors; | |
541 | unsigned long flags; | |
542 | ||
543 | if (info->rq == NULL) | |
544 | return; | |
545 | ||
546 | spin_lock_irqsave(&blkif_io_lock, flags); | |
547 | ||
548 | /* No more blkif_request(). */ | |
549 | blk_stop_queue(info->rq); | |
550 | ||
551 | /* No more gnttab callback work. */ | |
552 | gnttab_cancel_free_callback(&info->callback); | |
553 | spin_unlock_irqrestore(&blkif_io_lock, flags); | |
554 | ||
555 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
556 | flush_scheduled_work(); | |
557 | ||
558 | del_gendisk(info->gd); | |
559 | ||
560 | minor = info->gd->first_minor; | |
561 | nr_minors = info->gd->minors; | |
562 | xlbd_release_minors(minor, nr_minors); | |
563 | ||
564 | blk_cleanup_queue(info->rq); | |
565 | info->rq = NULL; | |
566 | ||
567 | put_disk(info->gd); | |
568 | info->gd = NULL; | |
569 | } | |
570 | ||
9f27ee59 JF |
571 | static void kick_pending_request_queues(struct blkfront_info *info) |
572 | { | |
573 | if (!RING_FULL(&info->ring)) { | |
574 | /* Re-enable calldowns. */ | |
575 | blk_start_queue(info->rq); | |
576 | /* Kick things off immediately. */ | |
577 | do_blkif_request(info->rq); | |
578 | } | |
579 | } | |
580 | ||
581 | static void blkif_restart_queue(struct work_struct *work) | |
582 | { | |
583 | struct blkfront_info *info = container_of(work, struct blkfront_info, work); | |
584 | ||
585 | spin_lock_irq(&blkif_io_lock); | |
586 | if (info->connected == BLKIF_STATE_CONNECTED) | |
587 | kick_pending_request_queues(info); | |
588 | spin_unlock_irq(&blkif_io_lock); | |
589 | } | |
590 | ||
591 | static void blkif_free(struct blkfront_info *info, int suspend) | |
592 | { | |
593 | /* Prevent new requests being issued until we fix things up. */ | |
594 | spin_lock_irq(&blkif_io_lock); | |
595 | info->connected = suspend ? | |
596 | BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; | |
597 | /* No more blkif_request(). */ | |
598 | if (info->rq) | |
599 | blk_stop_queue(info->rq); | |
600 | /* No more gnttab callback work. */ | |
601 | gnttab_cancel_free_callback(&info->callback); | |
602 | spin_unlock_irq(&blkif_io_lock); | |
603 | ||
604 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
605 | flush_scheduled_work(); | |
606 | ||
607 | /* Free resources associated with old device channel. */ | |
608 | if (info->ring_ref != GRANT_INVALID_REF) { | |
609 | gnttab_end_foreign_access(info->ring_ref, 0, | |
610 | (unsigned long)info->ring.sring); | |
611 | info->ring_ref = GRANT_INVALID_REF; | |
612 | info->ring.sring = NULL; | |
613 | } | |
614 | if (info->irq) | |
615 | unbind_from_irqhandler(info->irq, info); | |
616 | info->evtchn = info->irq = 0; | |
617 | ||
618 | } | |
619 | ||
620 | static void blkif_completion(struct blk_shadow *s) | |
621 | { | |
622 | int i; | |
623 | for (i = 0; i < s->req.nr_segments; i++) | |
624 | gnttab_end_foreign_access(s->req.seg[i].gref, 0, 0UL); | |
625 | } | |
626 | ||
627 | static irqreturn_t blkif_interrupt(int irq, void *dev_id) | |
628 | { | |
629 | struct request *req; | |
630 | struct blkif_response *bret; | |
631 | RING_IDX i, rp; | |
632 | unsigned long flags; | |
633 | struct blkfront_info *info = (struct blkfront_info *)dev_id; | |
f530f036 | 634 | int error; |
9f27ee59 JF |
635 | |
636 | spin_lock_irqsave(&blkif_io_lock, flags); | |
637 | ||
638 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { | |
639 | spin_unlock_irqrestore(&blkif_io_lock, flags); | |
640 | return IRQ_HANDLED; | |
641 | } | |
642 | ||
643 | again: | |
644 | rp = info->ring.sring->rsp_prod; | |
645 | rmb(); /* Ensure we see queued responses up to 'rp'. */ | |
646 | ||
647 | for (i = info->ring.rsp_cons; i != rp; i++) { | |
648 | unsigned long id; | |
9f27ee59 JF |
649 | |
650 | bret = RING_GET_RESPONSE(&info->ring, i); | |
651 | id = bret->id; | |
652 | req = (struct request *)info->shadow[id].request; | |
653 | ||
654 | blkif_completion(&info->shadow[id]); | |
655 | ||
656 | add_id_to_freelist(info, id); | |
657 | ||
f530f036 | 658 | error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO; |
9f27ee59 JF |
659 | switch (bret->operation) { |
660 | case BLKIF_OP_WRITE_BARRIER: | |
661 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
662 | printk(KERN_WARNING "blkfront: %s: write barrier op failed\n", | |
663 | info->gd->disk_name); | |
f530f036 | 664 | error = -EOPNOTSUPP; |
9f27ee59 JF |
665 | info->feature_barrier = 0; |
666 | xlvbd_barrier(info); | |
667 | } | |
668 | /* fall through */ | |
669 | case BLKIF_OP_READ: | |
670 | case BLKIF_OP_WRITE: | |
671 | if (unlikely(bret->status != BLKIF_RSP_OKAY)) | |
672 | dev_dbg(&info->xbdev->dev, "Bad return from blkdev data " | |
673 | "request: %x\n", bret->status); | |
674 | ||
40cbbb78 | 675 | __blk_end_request_all(req, error); |
9f27ee59 JF |
676 | break; |
677 | default: | |
678 | BUG(); | |
679 | } | |
680 | } | |
681 | ||
682 | info->ring.rsp_cons = i; | |
683 | ||
684 | if (i != info->ring.req_prod_pvt) { | |
685 | int more_to_do; | |
686 | RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do); | |
687 | if (more_to_do) | |
688 | goto again; | |
689 | } else | |
690 | info->ring.sring->rsp_event = i + 1; | |
691 | ||
692 | kick_pending_request_queues(info); | |
693 | ||
694 | spin_unlock_irqrestore(&blkif_io_lock, flags); | |
695 | ||
696 | return IRQ_HANDLED; | |
697 | } | |
698 | ||
699 | ||
700 | static int setup_blkring(struct xenbus_device *dev, | |
701 | struct blkfront_info *info) | |
702 | { | |
703 | struct blkif_sring *sring; | |
704 | int err; | |
705 | ||
706 | info->ring_ref = GRANT_INVALID_REF; | |
707 | ||
a144ff09 | 708 | sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH); |
9f27ee59 JF |
709 | if (!sring) { |
710 | xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); | |
711 | return -ENOMEM; | |
712 | } | |
713 | SHARED_RING_INIT(sring); | |
714 | FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE); | |
9e973e64 JA |
715 | |
716 | sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
9f27ee59 JF |
717 | |
718 | err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring)); | |
719 | if (err < 0) { | |
720 | free_page((unsigned long)sring); | |
721 | info->ring.sring = NULL; | |
722 | goto fail; | |
723 | } | |
724 | info->ring_ref = err; | |
725 | ||
726 | err = xenbus_alloc_evtchn(dev, &info->evtchn); | |
727 | if (err) | |
728 | goto fail; | |
729 | ||
730 | err = bind_evtchn_to_irqhandler(info->evtchn, | |
731 | blkif_interrupt, | |
732 | IRQF_SAMPLE_RANDOM, "blkif", info); | |
733 | if (err <= 0) { | |
734 | xenbus_dev_fatal(dev, err, | |
735 | "bind_evtchn_to_irqhandler failed"); | |
736 | goto fail; | |
737 | } | |
738 | info->irq = err; | |
739 | ||
740 | return 0; | |
741 | fail: | |
742 | blkif_free(info, 0); | |
743 | return err; | |
744 | } | |
745 | ||
746 | ||
747 | /* Common code used when first setting up, and when resuming. */ | |
203fd61f | 748 | static int talk_to_blkback(struct xenbus_device *dev, |
9f27ee59 JF |
749 | struct blkfront_info *info) |
750 | { | |
751 | const char *message = NULL; | |
752 | struct xenbus_transaction xbt; | |
753 | int err; | |
754 | ||
755 | /* Create shared ring, alloc event channel. */ | |
756 | err = setup_blkring(dev, info); | |
757 | if (err) | |
758 | goto out; | |
759 | ||
760 | again: | |
761 | err = xenbus_transaction_start(&xbt); | |
762 | if (err) { | |
763 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
764 | goto destroy_blkring; | |
765 | } | |
766 | ||
767 | err = xenbus_printf(xbt, dev->nodename, | |
768 | "ring-ref", "%u", info->ring_ref); | |
769 | if (err) { | |
770 | message = "writing ring-ref"; | |
771 | goto abort_transaction; | |
772 | } | |
773 | err = xenbus_printf(xbt, dev->nodename, | |
774 | "event-channel", "%u", info->evtchn); | |
775 | if (err) { | |
776 | message = "writing event-channel"; | |
777 | goto abort_transaction; | |
778 | } | |
3e334239 MA |
779 | err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", |
780 | XEN_IO_PROTO_ABI_NATIVE); | |
781 | if (err) { | |
782 | message = "writing protocol"; | |
783 | goto abort_transaction; | |
784 | } | |
9f27ee59 JF |
785 | |
786 | err = xenbus_transaction_end(xbt, 0); | |
787 | if (err) { | |
788 | if (err == -EAGAIN) | |
789 | goto again; | |
790 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
791 | goto destroy_blkring; | |
792 | } | |
793 | ||
794 | xenbus_switch_state(dev, XenbusStateInitialised); | |
795 | ||
796 | return 0; | |
797 | ||
798 | abort_transaction: | |
799 | xenbus_transaction_end(xbt, 1); | |
800 | if (message) | |
801 | xenbus_dev_fatal(dev, err, "%s", message); | |
802 | destroy_blkring: | |
803 | blkif_free(info, 0); | |
804 | out: | |
805 | return err; | |
806 | } | |
807 | ||
9f27ee59 JF |
808 | /** |
809 | * Entry point to this code when a new device is created. Allocate the basic | |
810 | * structures and the ring buffer for communication with the backend, and | |
811 | * inform the backend of the appropriate details for those. Switch to | |
812 | * Initialised state. | |
813 | */ | |
814 | static int blkfront_probe(struct xenbus_device *dev, | |
815 | const struct xenbus_device_id *id) | |
816 | { | |
817 | int err, vdevice, i; | |
818 | struct blkfront_info *info; | |
819 | ||
820 | /* FIXME: Use dynamic device id if this is not set. */ | |
821 | err = xenbus_scanf(XBT_NIL, dev->nodename, | |
822 | "virtual-device", "%i", &vdevice); | |
823 | if (err != 1) { | |
9246b5f0 CL |
824 | /* go looking in the extended area instead */ |
825 | err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext", | |
826 | "%i", &vdevice); | |
827 | if (err != 1) { | |
828 | xenbus_dev_fatal(dev, err, "reading virtual-device"); | |
829 | return err; | |
830 | } | |
9f27ee59 JF |
831 | } |
832 | ||
833 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
834 | if (!info) { | |
835 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
836 | return -ENOMEM; | |
837 | } | |
838 | ||
b70f5fa0 | 839 | mutex_init(&info->mutex); |
9f27ee59 JF |
840 | info->xbdev = dev; |
841 | info->vdevice = vdevice; | |
842 | info->connected = BLKIF_STATE_DISCONNECTED; | |
843 | INIT_WORK(&info->work, blkif_restart_queue); | |
844 | ||
845 | for (i = 0; i < BLK_RING_SIZE; i++) | |
846 | info->shadow[i].req.id = i+1; | |
847 | info->shadow[BLK_RING_SIZE-1].req.id = 0x0fffffff; | |
848 | ||
849 | /* Front end dir is a number, which is used as the id. */ | |
850 | info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); | |
a1b4b12b | 851 | dev_set_drvdata(&dev->dev, info); |
9f27ee59 | 852 | |
203fd61f | 853 | err = talk_to_blkback(dev, info); |
9f27ee59 JF |
854 | if (err) { |
855 | kfree(info); | |
a1b4b12b | 856 | dev_set_drvdata(&dev->dev, NULL); |
9f27ee59 JF |
857 | return err; |
858 | } | |
859 | ||
860 | return 0; | |
861 | } | |
862 | ||
863 | ||
864 | static int blkif_recover(struct blkfront_info *info) | |
865 | { | |
866 | int i; | |
867 | struct blkif_request *req; | |
868 | struct blk_shadow *copy; | |
869 | int j; | |
870 | ||
871 | /* Stage 1: Make a safe copy of the shadow state. */ | |
a144ff09 IC |
872 | copy = kmalloc(sizeof(info->shadow), |
873 | GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); | |
9f27ee59 JF |
874 | if (!copy) |
875 | return -ENOMEM; | |
876 | memcpy(copy, info->shadow, sizeof(info->shadow)); | |
877 | ||
878 | /* Stage 2: Set up free list. */ | |
879 | memset(&info->shadow, 0, sizeof(info->shadow)); | |
880 | for (i = 0; i < BLK_RING_SIZE; i++) | |
881 | info->shadow[i].req.id = i+1; | |
882 | info->shadow_free = info->ring.req_prod_pvt; | |
883 | info->shadow[BLK_RING_SIZE-1].req.id = 0x0fffffff; | |
884 | ||
885 | /* Stage 3: Find pending requests and requeue them. */ | |
886 | for (i = 0; i < BLK_RING_SIZE; i++) { | |
887 | /* Not in use? */ | |
888 | if (copy[i].request == 0) | |
889 | continue; | |
890 | ||
891 | /* Grab a request slot and copy shadow state into it. */ | |
892 | req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
893 | *req = copy[i].req; | |
894 | ||
895 | /* We get a new request id, and must reset the shadow state. */ | |
896 | req->id = get_id_from_freelist(info); | |
897 | memcpy(&info->shadow[req->id], ©[i], sizeof(copy[i])); | |
898 | ||
899 | /* Rewrite any grant references invalidated by susp/resume. */ | |
900 | for (j = 0; j < req->nr_segments; j++) | |
901 | gnttab_grant_foreign_access_ref( | |
902 | req->seg[j].gref, | |
903 | info->xbdev->otherend_id, | |
904 | pfn_to_mfn(info->shadow[req->id].frame[j]), | |
905 | rq_data_dir( | |
906 | (struct request *) | |
907 | info->shadow[req->id].request)); | |
908 | info->shadow[req->id].req = *req; | |
909 | ||
910 | info->ring.req_prod_pvt++; | |
911 | } | |
912 | ||
913 | kfree(copy); | |
914 | ||
915 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
916 | ||
917 | spin_lock_irq(&blkif_io_lock); | |
918 | ||
919 | /* Now safe for us to use the shared ring */ | |
920 | info->connected = BLKIF_STATE_CONNECTED; | |
921 | ||
922 | /* Send off requeued requests */ | |
923 | flush_requests(info); | |
924 | ||
925 | /* Kick any other new requests queued since we resumed */ | |
926 | kick_pending_request_queues(info); | |
927 | ||
928 | spin_unlock_irq(&blkif_io_lock); | |
929 | ||
930 | return 0; | |
931 | } | |
932 | ||
933 | /** | |
934 | * We are reconnecting to the backend, due to a suspend/resume, or a backend | |
935 | * driver restart. We tear down our blkif structure and recreate it, but | |
936 | * leave the device-layer structures intact so that this is transparent to the | |
937 | * rest of the kernel. | |
938 | */ | |
939 | static int blkfront_resume(struct xenbus_device *dev) | |
940 | { | |
a1b4b12b | 941 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 JF |
942 | int err; |
943 | ||
944 | dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename); | |
945 | ||
946 | blkif_free(info, info->connected == BLKIF_STATE_CONNECTED); | |
947 | ||
203fd61f | 948 | err = talk_to_blkback(dev, info); |
9f27ee59 JF |
949 | if (info->connected == BLKIF_STATE_SUSPENDED && !err) |
950 | err = blkif_recover(info); | |
951 | ||
952 | return err; | |
953 | } | |
954 | ||
b70f5fa0 DS |
955 | static void |
956 | blkfront_closing(struct blkfront_info *info) | |
957 | { | |
958 | struct xenbus_device *xbdev = info->xbdev; | |
959 | struct block_device *bdev = NULL; | |
960 | ||
961 | mutex_lock(&info->mutex); | |
962 | ||
963 | if (xbdev->state == XenbusStateClosing) { | |
964 | mutex_unlock(&info->mutex); | |
965 | return; | |
966 | } | |
967 | ||
968 | if (info->gd) | |
969 | bdev = bdget_disk(info->gd, 0); | |
970 | ||
971 | mutex_unlock(&info->mutex); | |
972 | ||
973 | if (!bdev) { | |
974 | xenbus_frontend_closed(xbdev); | |
975 | return; | |
976 | } | |
977 | ||
978 | mutex_lock(&bdev->bd_mutex); | |
979 | ||
980 | if (info->users) { | |
981 | xenbus_dev_error(xbdev, -EBUSY, | |
982 | "Device in use; refusing to close"); | |
983 | xenbus_switch_state(xbdev, XenbusStateClosing); | |
984 | } else { | |
985 | xlvbd_release_gendisk(info); | |
986 | xenbus_frontend_closed(xbdev); | |
987 | } | |
988 | ||
989 | mutex_unlock(&bdev->bd_mutex); | |
990 | bdput(bdev); | |
991 | } | |
9f27ee59 JF |
992 | |
993 | /* | |
994 | * Invoked when the backend is finally 'ready' (and has told produced | |
995 | * the details about the physical device - #sectors, size, etc). | |
996 | */ | |
997 | static void blkfront_connect(struct blkfront_info *info) | |
998 | { | |
999 | unsigned long long sectors; | |
1000 | unsigned long sector_size; | |
1001 | unsigned int binfo; | |
1002 | int err; | |
1003 | ||
1fa73be6 S |
1004 | switch (info->connected) { |
1005 | case BLKIF_STATE_CONNECTED: | |
1006 | /* | |
1007 | * Potentially, the back-end may be signalling | |
1008 | * a capacity change; update the capacity. | |
1009 | */ | |
1010 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1011 | "sectors", "%Lu", §ors); | |
1012 | if (XENBUS_EXIST_ERR(err)) | |
1013 | return; | |
1014 | printk(KERN_INFO "Setting capacity to %Lu\n", | |
1015 | sectors); | |
1016 | set_capacity(info->gd, sectors); | |
2def141e | 1017 | revalidate_disk(info->gd); |
1fa73be6 S |
1018 | |
1019 | /* fall through */ | |
1020 | case BLKIF_STATE_SUSPENDED: | |
9f27ee59 | 1021 | return; |
b4dddb49 JF |
1022 | |
1023 | default: | |
1024 | break; | |
1fa73be6 | 1025 | } |
9f27ee59 JF |
1026 | |
1027 | dev_dbg(&info->xbdev->dev, "%s:%s.\n", | |
1028 | __func__, info->xbdev->otherend); | |
1029 | ||
1030 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1031 | "sectors", "%llu", §ors, | |
1032 | "info", "%u", &binfo, | |
1033 | "sector-size", "%lu", §or_size, | |
1034 | NULL); | |
1035 | if (err) { | |
1036 | xenbus_dev_fatal(info->xbdev, err, | |
1037 | "reading backend fields at %s", | |
1038 | info->xbdev->otherend); | |
1039 | return; | |
1040 | } | |
1041 | ||
1042 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1043 | "feature-barrier", "%lu", &info->feature_barrier, | |
1044 | NULL); | |
1045 | if (err) | |
1046 | info->feature_barrier = 0; | |
1047 | ||
9246b5f0 | 1048 | err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size); |
9f27ee59 JF |
1049 | if (err) { |
1050 | xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", | |
1051 | info->xbdev->otherend); | |
1052 | return; | |
1053 | } | |
1054 | ||
1055 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1056 | ||
1057 | /* Kick pending requests. */ | |
1058 | spin_lock_irq(&blkif_io_lock); | |
1059 | info->connected = BLKIF_STATE_CONNECTED; | |
1060 | kick_pending_request_queues(info); | |
1061 | spin_unlock_irq(&blkif_io_lock); | |
1062 | ||
1063 | add_disk(info->gd); | |
1d78d705 CL |
1064 | |
1065 | info->is_ready = 1; | |
9f27ee59 JF |
1066 | } |
1067 | ||
9f27ee59 JF |
1068 | /** |
1069 | * Callback received when the backend's state changes. | |
1070 | */ | |
203fd61f | 1071 | static void blkback_changed(struct xenbus_device *dev, |
9f27ee59 JF |
1072 | enum xenbus_state backend_state) |
1073 | { | |
a1b4b12b | 1074 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 | 1075 | |
203fd61f | 1076 | dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); |
9f27ee59 JF |
1077 | |
1078 | switch (backend_state) { | |
1079 | case XenbusStateInitialising: | |
1080 | case XenbusStateInitWait: | |
1081 | case XenbusStateInitialised: | |
1082 | case XenbusStateUnknown: | |
1083 | case XenbusStateClosed: | |
1084 | break; | |
1085 | ||
1086 | case XenbusStateConnected: | |
1087 | blkfront_connect(info); | |
1088 | break; | |
1089 | ||
1090 | case XenbusStateClosing: | |
b70f5fa0 | 1091 | blkfront_closing(info); |
9f27ee59 JF |
1092 | break; |
1093 | } | |
1094 | } | |
1095 | ||
fa1bd359 | 1096 | static int blkfront_remove(struct xenbus_device *xbdev) |
9f27ee59 | 1097 | { |
fa1bd359 DS |
1098 | struct blkfront_info *info = dev_get_drvdata(&xbdev->dev); |
1099 | struct block_device *bdev = NULL; | |
1100 | struct gendisk *disk; | |
9f27ee59 | 1101 | |
fa1bd359 | 1102 | dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename); |
9f27ee59 JF |
1103 | |
1104 | blkif_free(info, 0); | |
1105 | ||
fa1bd359 DS |
1106 | mutex_lock(&info->mutex); |
1107 | ||
1108 | disk = info->gd; | |
1109 | if (disk) | |
1110 | bdev = bdget_disk(disk, 0); | |
1111 | ||
1112 | info->xbdev = NULL; | |
1113 | mutex_unlock(&info->mutex); | |
1114 | ||
1115 | if (!bdev) { | |
1116 | kfree(info); | |
1117 | return 0; | |
1118 | } | |
1119 | ||
1120 | /* | |
1121 | * The xbdev was removed before we reached the Closed | |
1122 | * state. See if it's safe to remove the disk. If the bdev | |
1123 | * isn't closed yet, we let release take care of it. | |
1124 | */ | |
1125 | ||
1126 | mutex_lock(&bdev->bd_mutex); | |
1127 | info = disk->private_data; | |
1128 | ||
1129 | if (info && !info->users) { | |
1130 | xlvbd_release_gendisk(info); | |
1131 | disk->private_data = NULL; | |
0e345826 | 1132 | kfree(info); |
fa1bd359 DS |
1133 | } |
1134 | ||
1135 | mutex_unlock(&bdev->bd_mutex); | |
1136 | bdput(bdev); | |
9f27ee59 JF |
1137 | |
1138 | return 0; | |
1139 | } | |
1140 | ||
1d78d705 CL |
1141 | static int blkfront_is_ready(struct xenbus_device *dev) |
1142 | { | |
a1b4b12b | 1143 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
1d78d705 | 1144 | |
5d7ed20e | 1145 | return info->is_ready && info->xbdev; |
1d78d705 CL |
1146 | } |
1147 | ||
a63c848b | 1148 | static int blkif_open(struct block_device *bdev, fmode_t mode) |
9f27ee59 | 1149 | { |
13961743 DS |
1150 | struct gendisk *disk = bdev->bd_disk; |
1151 | struct blkfront_info *info; | |
1152 | int err = 0; | |
6e9624b8 AB |
1153 | |
1154 | lock_kernel(); | |
6e9624b8 | 1155 | |
13961743 DS |
1156 | info = disk->private_data; |
1157 | if (!info) { | |
1158 | /* xbdev gone */ | |
1159 | err = -ERESTARTSYS; | |
1160 | goto out; | |
1161 | } | |
1162 | ||
1163 | mutex_lock(&info->mutex); | |
1164 | ||
1165 | if (!info->gd) | |
1166 | /* xbdev is closed */ | |
1167 | err = -ERESTARTSYS; | |
1168 | ||
1169 | mutex_unlock(&info->mutex); | |
1170 | ||
13961743 | 1171 | out: |
7fd152f4 | 1172 | unlock_kernel(); |
13961743 | 1173 | return err; |
9f27ee59 JF |
1174 | } |
1175 | ||
a63c848b | 1176 | static int blkif_release(struct gendisk *disk, fmode_t mode) |
9f27ee59 | 1177 | { |
a63c848b | 1178 | struct blkfront_info *info = disk->private_data; |
7fd152f4 DS |
1179 | struct block_device *bdev; |
1180 | struct xenbus_device *xbdev; | |
1181 | ||
6e9624b8 | 1182 | lock_kernel(); |
7fd152f4 DS |
1183 | |
1184 | bdev = bdget_disk(disk, 0); | |
1185 | bdput(bdev); | |
1186 | ||
acfca3c6 DS |
1187 | if (bdev->bd_openers) |
1188 | goto out; | |
1189 | ||
7fd152f4 DS |
1190 | /* |
1191 | * Check if we have been instructed to close. We will have | |
1192 | * deferred this request, because the bdev was still open. | |
1193 | */ | |
1194 | ||
1195 | mutex_lock(&info->mutex); | |
1196 | xbdev = info->xbdev; | |
1197 | ||
1198 | if (xbdev && xbdev->state == XenbusStateClosing) { | |
1199 | /* pending switch to state closed */ | |
1200 | xlvbd_release_gendisk(info); | |
1201 | xenbus_frontend_closed(info->xbdev); | |
1202 | } | |
1203 | ||
1204 | mutex_unlock(&info->mutex); | |
1205 | ||
1206 | if (!xbdev) { | |
1207 | /* sudden device removal */ | |
1208 | xlvbd_release_gendisk(info); | |
1209 | disk->private_data = NULL; | |
1210 | kfree(info); | |
9f27ee59 | 1211 | } |
7fd152f4 | 1212 | |
6e9624b8 | 1213 | unlock_kernel(); |
9f27ee59 JF |
1214 | return 0; |
1215 | } | |
1216 | ||
83d5cde4 | 1217 | static const struct block_device_operations xlvbd_block_fops = |
9f27ee59 JF |
1218 | { |
1219 | .owner = THIS_MODULE, | |
a63c848b AV |
1220 | .open = blkif_open, |
1221 | .release = blkif_release, | |
597592d9 | 1222 | .getgeo = blkif_getgeo, |
8a6cfeb6 | 1223 | .ioctl = blkif_ioctl, |
9f27ee59 JF |
1224 | }; |
1225 | ||
1226 | ||
ec9c42ec | 1227 | static const struct xenbus_device_id blkfront_ids[] = { |
9f27ee59 JF |
1228 | { "vbd" }, |
1229 | { "" } | |
1230 | }; | |
1231 | ||
1232 | static struct xenbus_driver blkfront = { | |
1233 | .name = "vbd", | |
1234 | .owner = THIS_MODULE, | |
1235 | .ids = blkfront_ids, | |
1236 | .probe = blkfront_probe, | |
1237 | .remove = blkfront_remove, | |
1238 | .resume = blkfront_resume, | |
203fd61f | 1239 | .otherend_changed = blkback_changed, |
1d78d705 | 1240 | .is_ready = blkfront_is_ready, |
9f27ee59 JF |
1241 | }; |
1242 | ||
1243 | static int __init xlblk_init(void) | |
1244 | { | |
6e833587 | 1245 | if (!xen_domain()) |
9f27ee59 JF |
1246 | return -ENODEV; |
1247 | ||
1248 | if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { | |
1249 | printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", | |
1250 | XENVBD_MAJOR, DEV_NAME); | |
1251 | return -ENODEV; | |
1252 | } | |
1253 | ||
1254 | return xenbus_register_frontend(&blkfront); | |
1255 | } | |
1256 | module_init(xlblk_init); | |
1257 | ||
1258 | ||
5a60d0cd | 1259 | static void __exit xlblk_exit(void) |
9f27ee59 JF |
1260 | { |
1261 | return xenbus_unregister_driver(&blkfront); | |
1262 | } | |
1263 | module_exit(xlblk_exit); | |
1264 | ||
1265 | MODULE_DESCRIPTION("Xen virtual block device frontend"); | |
1266 | MODULE_LICENSE("GPL"); | |
1267 | MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR); | |
d2f0c52b | 1268 | MODULE_ALIAS("xen:vbd"); |
4f93f09b | 1269 | MODULE_ALIAS("xenblk"); |