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 | static DEFINE_SPINLOCK(blkif_io_lock); | |
102 | ||
0e345826 JB |
103 | static unsigned int nr_minors; |
104 | static unsigned long *minors; | |
105 | static DEFINE_SPINLOCK(minor_lock); | |
106 | ||
9f27ee59 JF |
107 | #define MAXIMUM_OUTSTANDING_BLOCK_REQS \ |
108 | (BLKIF_MAX_SEGMENTS_PER_REQUEST * BLK_RING_SIZE) | |
109 | #define GRANT_INVALID_REF 0 | |
110 | ||
111 | #define PARTS_PER_DISK 16 | |
9246b5f0 | 112 | #define PARTS_PER_EXT_DISK 256 |
9f27ee59 JF |
113 | |
114 | #define BLKIF_MAJOR(dev) ((dev)>>8) | |
115 | #define BLKIF_MINOR(dev) ((dev) & 0xff) | |
116 | ||
9246b5f0 CL |
117 | #define EXT_SHIFT 28 |
118 | #define EXTENDED (1<<EXT_SHIFT) | |
119 | #define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED)) | |
120 | #define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED)) | |
9f27ee59 | 121 | |
9246b5f0 | 122 | #define DEV_NAME "xvd" /* name in /dev */ |
9f27ee59 JF |
123 | |
124 | static int get_id_from_freelist(struct blkfront_info *info) | |
125 | { | |
126 | unsigned long free = info->shadow_free; | |
b9ed7252 | 127 | BUG_ON(free >= BLK_RING_SIZE); |
9f27ee59 JF |
128 | info->shadow_free = info->shadow[free].req.id; |
129 | info->shadow[free].req.id = 0x0fffffee; /* debug */ | |
130 | return free; | |
131 | } | |
132 | ||
133 | static void add_id_to_freelist(struct blkfront_info *info, | |
134 | unsigned long id) | |
135 | { | |
136 | info->shadow[id].req.id = info->shadow_free; | |
137 | info->shadow[id].request = 0; | |
138 | info->shadow_free = id; | |
139 | } | |
140 | ||
0e345826 JB |
141 | static int xlbd_reserve_minors(unsigned int minor, unsigned int nr) |
142 | { | |
143 | unsigned int end = minor + nr; | |
144 | int rc; | |
145 | ||
146 | if (end > nr_minors) { | |
147 | unsigned long *bitmap, *old; | |
148 | ||
149 | bitmap = kzalloc(BITS_TO_LONGS(end) * sizeof(*bitmap), | |
150 | GFP_KERNEL); | |
151 | if (bitmap == NULL) | |
152 | return -ENOMEM; | |
153 | ||
154 | spin_lock(&minor_lock); | |
155 | if (end > nr_minors) { | |
156 | old = minors; | |
157 | memcpy(bitmap, minors, | |
158 | BITS_TO_LONGS(nr_minors) * sizeof(*bitmap)); | |
159 | minors = bitmap; | |
160 | nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG; | |
161 | } else | |
162 | old = bitmap; | |
163 | spin_unlock(&minor_lock); | |
164 | kfree(old); | |
165 | } | |
166 | ||
167 | spin_lock(&minor_lock); | |
168 | if (find_next_bit(minors, end, minor) >= end) { | |
169 | for (; minor < end; ++minor) | |
170 | __set_bit(minor, minors); | |
171 | rc = 0; | |
172 | } else | |
173 | rc = -EBUSY; | |
174 | spin_unlock(&minor_lock); | |
175 | ||
176 | return rc; | |
177 | } | |
178 | ||
179 | static void xlbd_release_minors(unsigned int minor, unsigned int nr) | |
180 | { | |
181 | unsigned int end = minor + nr; | |
182 | ||
183 | BUG_ON(end > nr_minors); | |
184 | spin_lock(&minor_lock); | |
185 | for (; minor < end; ++minor) | |
186 | __clear_bit(minor, minors); | |
187 | spin_unlock(&minor_lock); | |
188 | } | |
189 | ||
9f27ee59 JF |
190 | static void blkif_restart_queue_callback(void *arg) |
191 | { | |
192 | struct blkfront_info *info = (struct blkfront_info *)arg; | |
193 | schedule_work(&info->work); | |
194 | } | |
195 | ||
afe42d7d | 196 | static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg) |
597592d9 IC |
197 | { |
198 | /* We don't have real geometry info, but let's at least return | |
199 | values consistent with the size of the device */ | |
200 | sector_t nsect = get_capacity(bd->bd_disk); | |
201 | sector_t cylinders = nsect; | |
202 | ||
203 | hg->heads = 0xff; | |
204 | hg->sectors = 0x3f; | |
205 | sector_div(cylinders, hg->heads * hg->sectors); | |
206 | hg->cylinders = cylinders; | |
207 | if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect) | |
208 | hg->cylinders = 0xffff; | |
209 | return 0; | |
210 | } | |
211 | ||
a63c848b | 212 | static int blkif_ioctl(struct block_device *bdev, fmode_t mode, |
62aa0054 | 213 | unsigned command, unsigned long argument) |
440a01a7 | 214 | { |
a63c848b | 215 | struct blkfront_info *info = bdev->bd_disk->private_data; |
440a01a7 CL |
216 | int i; |
217 | ||
218 | dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n", | |
219 | command, (long)argument); | |
220 | ||
221 | switch (command) { | |
222 | case CDROMMULTISESSION: | |
223 | dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n"); | |
224 | for (i = 0; i < sizeof(struct cdrom_multisession); i++) | |
225 | if (put_user(0, (char __user *)(argument + i))) | |
226 | return -EFAULT; | |
227 | return 0; | |
228 | ||
229 | case CDROM_GET_CAPABILITY: { | |
230 | struct gendisk *gd = info->gd; | |
231 | if (gd->flags & GENHD_FL_CD) | |
232 | return 0; | |
233 | return -EINVAL; | |
234 | } | |
235 | ||
236 | default: | |
237 | /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n", | |
238 | command);*/ | |
239 | return -EINVAL; /* same return as native Linux */ | |
240 | } | |
241 | ||
242 | return 0; | |
243 | } | |
244 | ||
9f27ee59 JF |
245 | /* |
246 | * blkif_queue_request | |
247 | * | |
248 | * request block io | |
249 | * | |
250 | * id: for guest use only. | |
251 | * operation: BLKIF_OP_{READ,WRITE,PROBE} | |
252 | * buffer: buffer to read/write into. this should be a | |
253 | * virtual address in the guest os. | |
254 | */ | |
255 | static int blkif_queue_request(struct request *req) | |
256 | { | |
257 | struct blkfront_info *info = req->rq_disk->private_data; | |
258 | unsigned long buffer_mfn; | |
259 | struct blkif_request *ring_req; | |
9f27ee59 JF |
260 | unsigned long id; |
261 | unsigned int fsect, lsect; | |
9e973e64 | 262 | int i, ref; |
9f27ee59 | 263 | grant_ref_t gref_head; |
9e973e64 | 264 | struct scatterlist *sg; |
9f27ee59 JF |
265 | |
266 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) | |
267 | return 1; | |
268 | ||
269 | if (gnttab_alloc_grant_references( | |
270 | BLKIF_MAX_SEGMENTS_PER_REQUEST, &gref_head) < 0) { | |
271 | gnttab_request_free_callback( | |
272 | &info->callback, | |
273 | blkif_restart_queue_callback, | |
274 | info, | |
275 | BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
276 | return 1; | |
277 | } | |
278 | ||
279 | /* Fill out a communications ring structure. */ | |
280 | ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
281 | id = get_id_from_freelist(info); | |
282 | info->shadow[id].request = (unsigned long)req; | |
283 | ||
284 | ring_req->id = id; | |
83096ebf | 285 | ring_req->sector_number = (blkif_sector_t)blk_rq_pos(req); |
9f27ee59 JF |
286 | ring_req->handle = info->handle; |
287 | ||
288 | ring_req->operation = rq_data_dir(req) ? | |
289 | BLKIF_OP_WRITE : BLKIF_OP_READ; | |
33659ebb | 290 | if (req->cmd_flags & REQ_HARDBARRIER) |
9f27ee59 JF |
291 | ring_req->operation = BLKIF_OP_WRITE_BARRIER; |
292 | ||
9e973e64 JA |
293 | ring_req->nr_segments = blk_rq_map_sg(req->q, req, info->sg); |
294 | BUG_ON(ring_req->nr_segments > BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
295 | ||
296 | for_each_sg(info->sg, sg, ring_req->nr_segments, i) { | |
297 | buffer_mfn = pfn_to_mfn(page_to_pfn(sg_page(sg))); | |
298 | fsect = sg->offset >> 9; | |
299 | lsect = fsect + (sg->length >> 9) - 1; | |
6c92e699 JA |
300 | /* install a grant reference. */ |
301 | ref = gnttab_claim_grant_reference(&gref_head); | |
302 | BUG_ON(ref == -ENOSPC); | |
303 | ||
304 | gnttab_grant_foreign_access_ref( | |
9f27ee59 JF |
305 | ref, |
306 | info->xbdev->otherend_id, | |
307 | buffer_mfn, | |
308 | rq_data_dir(req) ); | |
309 | ||
9e973e64 JA |
310 | info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn); |
311 | ring_req->seg[i] = | |
9f27ee59 JF |
312 | (struct blkif_request_segment) { |
313 | .gref = ref, | |
314 | .first_sect = fsect, | |
315 | .last_sect = lsect }; | |
9f27ee59 JF |
316 | } |
317 | ||
318 | info->ring.req_prod_pvt++; | |
319 | ||
320 | /* Keep a private copy so we can reissue requests when recovering. */ | |
321 | info->shadow[id].req = *ring_req; | |
322 | ||
323 | gnttab_free_grant_references(gref_head); | |
324 | ||
325 | return 0; | |
326 | } | |
327 | ||
328 | ||
329 | static inline void flush_requests(struct blkfront_info *info) | |
330 | { | |
331 | int notify; | |
332 | ||
333 | RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify); | |
334 | ||
335 | if (notify) | |
336 | notify_remote_via_irq(info->irq); | |
337 | } | |
338 | ||
339 | /* | |
340 | * do_blkif_request | |
341 | * read a block; request is in a request queue | |
342 | */ | |
165125e1 | 343 | static void do_blkif_request(struct request_queue *rq) |
9f27ee59 JF |
344 | { |
345 | struct blkfront_info *info = NULL; | |
346 | struct request *req; | |
347 | int queued; | |
348 | ||
349 | pr_debug("Entered do_blkif_request\n"); | |
350 | ||
351 | queued = 0; | |
352 | ||
9934c8c0 | 353 | while ((req = blk_peek_request(rq)) != NULL) { |
9f27ee59 | 354 | info = req->rq_disk->private_data; |
9f27ee59 JF |
355 | |
356 | if (RING_FULL(&info->ring)) | |
357 | goto wait; | |
358 | ||
9934c8c0 | 359 | blk_start_request(req); |
296b2f6a | 360 | |
33659ebb | 361 | if (req->cmd_type != REQ_TYPE_FS) { |
296b2f6a TH |
362 | __blk_end_request_all(req, -EIO); |
363 | continue; | |
364 | } | |
365 | ||
9f27ee59 | 366 | pr_debug("do_blk_req %p: cmd %p, sec %lx, " |
83096ebf TH |
367 | "(%u/%u) buffer:%p [%s]\n", |
368 | req, req->cmd, (unsigned long)blk_rq_pos(req), | |
369 | blk_rq_cur_sectors(req), blk_rq_sectors(req), | |
370 | req->buffer, rq_data_dir(req) ? "write" : "read"); | |
9f27ee59 | 371 | |
9f27ee59 JF |
372 | if (blkif_queue_request(req)) { |
373 | blk_requeue_request(rq, req); | |
374 | wait: | |
375 | /* Avoid pointless unplugs. */ | |
376 | blk_stop_queue(rq); | |
377 | break; | |
378 | } | |
379 | ||
380 | queued++; | |
381 | } | |
382 | ||
383 | if (queued != 0) | |
384 | flush_requests(info); | |
385 | } | |
386 | ||
387 | static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size) | |
388 | { | |
165125e1 | 389 | struct request_queue *rq; |
9f27ee59 JF |
390 | |
391 | rq = blk_init_queue(do_blkif_request, &blkif_io_lock); | |
392 | if (rq == NULL) | |
393 | return -1; | |
394 | ||
66d352e1 | 395 | queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq); |
9f27ee59 JF |
396 | |
397 | /* Hard sector size and max sectors impersonate the equiv. hardware. */ | |
e1defc4f | 398 | blk_queue_logical_block_size(rq, sector_size); |
086fa5ff | 399 | blk_queue_max_hw_sectors(rq, 512); |
9f27ee59 JF |
400 | |
401 | /* Each segment in a request is up to an aligned page in size. */ | |
402 | blk_queue_segment_boundary(rq, PAGE_SIZE - 1); | |
403 | blk_queue_max_segment_size(rq, PAGE_SIZE); | |
404 | ||
405 | /* Ensure a merged request will fit in a single I/O ring slot. */ | |
8a78362c | 406 | blk_queue_max_segments(rq, BLKIF_MAX_SEGMENTS_PER_REQUEST); |
9f27ee59 JF |
407 | |
408 | /* Make sure buffer addresses are sector-aligned. */ | |
409 | blk_queue_dma_alignment(rq, 511); | |
410 | ||
1c91fe1a IC |
411 | /* Make sure we don't use bounce buffers. */ |
412 | blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY); | |
413 | ||
9f27ee59 JF |
414 | gd->queue = rq; |
415 | ||
416 | return 0; | |
417 | } | |
418 | ||
419 | ||
420 | static int xlvbd_barrier(struct blkfront_info *info) | |
421 | { | |
422 | int err; | |
423 | ||
424 | err = blk_queue_ordered(info->rq, | |
00fff265 | 425 | info->feature_barrier ? QUEUE_ORDERED_DRAIN : QUEUE_ORDERED_NONE); |
9f27ee59 JF |
426 | |
427 | if (err) | |
428 | return err; | |
429 | ||
430 | printk(KERN_INFO "blkfront: %s: barriers %s\n", | |
431 | info->gd->disk_name, | |
432 | info->feature_barrier ? "enabled" : "disabled"); | |
433 | return 0; | |
434 | } | |
435 | ||
436 | ||
9246b5f0 CL |
437 | static int xlvbd_alloc_gendisk(blkif_sector_t capacity, |
438 | struct blkfront_info *info, | |
439 | u16 vdisk_info, u16 sector_size) | |
9f27ee59 JF |
440 | { |
441 | struct gendisk *gd; | |
442 | int nr_minors = 1; | |
443 | int err = -ENODEV; | |
9246b5f0 CL |
444 | unsigned int offset; |
445 | int minor; | |
446 | int nr_parts; | |
9f27ee59 JF |
447 | |
448 | BUG_ON(info->gd != NULL); | |
449 | BUG_ON(info->rq != NULL); | |
450 | ||
9246b5f0 CL |
451 | if ((info->vdevice>>EXT_SHIFT) > 1) { |
452 | /* this is above the extended range; something is wrong */ | |
453 | printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice); | |
454 | return -ENODEV; | |
455 | } | |
456 | ||
457 | if (!VDEV_IS_EXTENDED(info->vdevice)) { | |
458 | minor = BLKIF_MINOR(info->vdevice); | |
459 | nr_parts = PARTS_PER_DISK; | |
460 | } else { | |
461 | minor = BLKIF_MINOR_EXT(info->vdevice); | |
462 | nr_parts = PARTS_PER_EXT_DISK; | |
463 | } | |
464 | ||
465 | if ((minor % nr_parts) == 0) | |
466 | nr_minors = nr_parts; | |
9f27ee59 | 467 | |
0e345826 JB |
468 | err = xlbd_reserve_minors(minor, nr_minors); |
469 | if (err) | |
470 | goto out; | |
471 | err = -ENODEV; | |
472 | ||
9f27ee59 JF |
473 | gd = alloc_disk(nr_minors); |
474 | if (gd == NULL) | |
0e345826 | 475 | goto release; |
9f27ee59 | 476 | |
9246b5f0 CL |
477 | offset = minor / nr_parts; |
478 | ||
479 | if (nr_minors > 1) { | |
480 | if (offset < 26) | |
481 | sprintf(gd->disk_name, "%s%c", DEV_NAME, 'a' + offset); | |
482 | else | |
483 | sprintf(gd->disk_name, "%s%c%c", DEV_NAME, | |
484 | 'a' + ((offset / 26)-1), 'a' + (offset % 26)); | |
485 | } else { | |
486 | if (offset < 26) | |
487 | sprintf(gd->disk_name, "%s%c%d", DEV_NAME, | |
488 | 'a' + offset, | |
489 | minor & (nr_parts - 1)); | |
490 | else | |
491 | sprintf(gd->disk_name, "%s%c%c%d", DEV_NAME, | |
492 | 'a' + ((offset / 26) - 1), | |
493 | 'a' + (offset % 26), | |
494 | minor & (nr_parts - 1)); | |
495 | } | |
9f27ee59 JF |
496 | |
497 | gd->major = XENVBD_MAJOR; | |
498 | gd->first_minor = minor; | |
499 | gd->fops = &xlvbd_block_fops; | |
500 | gd->private_data = info; | |
501 | gd->driverfs_dev = &(info->xbdev->dev); | |
502 | set_capacity(gd, capacity); | |
503 | ||
504 | if (xlvbd_init_blk_queue(gd, sector_size)) { | |
505 | del_gendisk(gd); | |
0e345826 | 506 | goto release; |
9f27ee59 JF |
507 | } |
508 | ||
509 | info->rq = gd->queue; | |
510 | info->gd = gd; | |
511 | ||
512 | if (info->feature_barrier) | |
513 | xlvbd_barrier(info); | |
514 | ||
515 | if (vdisk_info & VDISK_READONLY) | |
516 | set_disk_ro(gd, 1); | |
517 | ||
518 | if (vdisk_info & VDISK_REMOVABLE) | |
519 | gd->flags |= GENHD_FL_REMOVABLE; | |
520 | ||
521 | if (vdisk_info & VDISK_CDROM) | |
522 | gd->flags |= GENHD_FL_CD; | |
523 | ||
524 | return 0; | |
525 | ||
0e345826 JB |
526 | release: |
527 | xlbd_release_minors(minor, nr_minors); | |
9f27ee59 JF |
528 | out: |
529 | return err; | |
530 | } | |
531 | ||
a66b5aeb DS |
532 | static void xlvbd_release_gendisk(struct blkfront_info *info) |
533 | { | |
534 | unsigned int minor, nr_minors; | |
535 | unsigned long flags; | |
536 | ||
537 | if (info->rq == NULL) | |
538 | return; | |
539 | ||
540 | spin_lock_irqsave(&blkif_io_lock, flags); | |
541 | ||
542 | /* No more blkif_request(). */ | |
543 | blk_stop_queue(info->rq); | |
544 | ||
545 | /* No more gnttab callback work. */ | |
546 | gnttab_cancel_free_callback(&info->callback); | |
547 | spin_unlock_irqrestore(&blkif_io_lock, flags); | |
548 | ||
549 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
550 | flush_scheduled_work(); | |
551 | ||
552 | del_gendisk(info->gd); | |
553 | ||
554 | minor = info->gd->first_minor; | |
555 | nr_minors = info->gd->minors; | |
556 | xlbd_release_minors(minor, nr_minors); | |
557 | ||
558 | blk_cleanup_queue(info->rq); | |
559 | info->rq = NULL; | |
560 | ||
561 | put_disk(info->gd); | |
562 | info->gd = NULL; | |
563 | } | |
564 | ||
9f27ee59 JF |
565 | static void kick_pending_request_queues(struct blkfront_info *info) |
566 | { | |
567 | if (!RING_FULL(&info->ring)) { | |
568 | /* Re-enable calldowns. */ | |
569 | blk_start_queue(info->rq); | |
570 | /* Kick things off immediately. */ | |
571 | do_blkif_request(info->rq); | |
572 | } | |
573 | } | |
574 | ||
575 | static void blkif_restart_queue(struct work_struct *work) | |
576 | { | |
577 | struct blkfront_info *info = container_of(work, struct blkfront_info, work); | |
578 | ||
579 | spin_lock_irq(&blkif_io_lock); | |
580 | if (info->connected == BLKIF_STATE_CONNECTED) | |
581 | kick_pending_request_queues(info); | |
582 | spin_unlock_irq(&blkif_io_lock); | |
583 | } | |
584 | ||
585 | static void blkif_free(struct blkfront_info *info, int suspend) | |
586 | { | |
587 | /* Prevent new requests being issued until we fix things up. */ | |
588 | spin_lock_irq(&blkif_io_lock); | |
589 | info->connected = suspend ? | |
590 | BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; | |
591 | /* No more blkif_request(). */ | |
592 | if (info->rq) | |
593 | blk_stop_queue(info->rq); | |
594 | /* No more gnttab callback work. */ | |
595 | gnttab_cancel_free_callback(&info->callback); | |
596 | spin_unlock_irq(&blkif_io_lock); | |
597 | ||
598 | /* Flush gnttab callback work. Must be done with no locks held. */ | |
599 | flush_scheduled_work(); | |
600 | ||
601 | /* Free resources associated with old device channel. */ | |
602 | if (info->ring_ref != GRANT_INVALID_REF) { | |
603 | gnttab_end_foreign_access(info->ring_ref, 0, | |
604 | (unsigned long)info->ring.sring); | |
605 | info->ring_ref = GRANT_INVALID_REF; | |
606 | info->ring.sring = NULL; | |
607 | } | |
608 | if (info->irq) | |
609 | unbind_from_irqhandler(info->irq, info); | |
610 | info->evtchn = info->irq = 0; | |
611 | ||
612 | } | |
613 | ||
614 | static void blkif_completion(struct blk_shadow *s) | |
615 | { | |
616 | int i; | |
617 | for (i = 0; i < s->req.nr_segments; i++) | |
618 | gnttab_end_foreign_access(s->req.seg[i].gref, 0, 0UL); | |
619 | } | |
620 | ||
621 | static irqreturn_t blkif_interrupt(int irq, void *dev_id) | |
622 | { | |
623 | struct request *req; | |
624 | struct blkif_response *bret; | |
625 | RING_IDX i, rp; | |
626 | unsigned long flags; | |
627 | struct blkfront_info *info = (struct blkfront_info *)dev_id; | |
f530f036 | 628 | int error; |
9f27ee59 JF |
629 | |
630 | spin_lock_irqsave(&blkif_io_lock, flags); | |
631 | ||
632 | if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { | |
633 | spin_unlock_irqrestore(&blkif_io_lock, flags); | |
634 | return IRQ_HANDLED; | |
635 | } | |
636 | ||
637 | again: | |
638 | rp = info->ring.sring->rsp_prod; | |
639 | rmb(); /* Ensure we see queued responses up to 'rp'. */ | |
640 | ||
641 | for (i = info->ring.rsp_cons; i != rp; i++) { | |
642 | unsigned long id; | |
9f27ee59 JF |
643 | |
644 | bret = RING_GET_RESPONSE(&info->ring, i); | |
645 | id = bret->id; | |
646 | req = (struct request *)info->shadow[id].request; | |
647 | ||
648 | blkif_completion(&info->shadow[id]); | |
649 | ||
650 | add_id_to_freelist(info, id); | |
651 | ||
f530f036 | 652 | error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO; |
9f27ee59 JF |
653 | switch (bret->operation) { |
654 | case BLKIF_OP_WRITE_BARRIER: | |
655 | if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) { | |
656 | printk(KERN_WARNING "blkfront: %s: write barrier op failed\n", | |
657 | info->gd->disk_name); | |
f530f036 | 658 | error = -EOPNOTSUPP; |
9f27ee59 JF |
659 | info->feature_barrier = 0; |
660 | xlvbd_barrier(info); | |
661 | } | |
662 | /* fall through */ | |
663 | case BLKIF_OP_READ: | |
664 | case BLKIF_OP_WRITE: | |
665 | if (unlikely(bret->status != BLKIF_RSP_OKAY)) | |
666 | dev_dbg(&info->xbdev->dev, "Bad return from blkdev data " | |
667 | "request: %x\n", bret->status); | |
668 | ||
40cbbb78 | 669 | __blk_end_request_all(req, error); |
9f27ee59 JF |
670 | break; |
671 | default: | |
672 | BUG(); | |
673 | } | |
674 | } | |
675 | ||
676 | info->ring.rsp_cons = i; | |
677 | ||
678 | if (i != info->ring.req_prod_pvt) { | |
679 | int more_to_do; | |
680 | RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do); | |
681 | if (more_to_do) | |
682 | goto again; | |
683 | } else | |
684 | info->ring.sring->rsp_event = i + 1; | |
685 | ||
686 | kick_pending_request_queues(info); | |
687 | ||
688 | spin_unlock_irqrestore(&blkif_io_lock, flags); | |
689 | ||
690 | return IRQ_HANDLED; | |
691 | } | |
692 | ||
693 | ||
694 | static int setup_blkring(struct xenbus_device *dev, | |
695 | struct blkfront_info *info) | |
696 | { | |
697 | struct blkif_sring *sring; | |
698 | int err; | |
699 | ||
700 | info->ring_ref = GRANT_INVALID_REF; | |
701 | ||
a144ff09 | 702 | sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH); |
9f27ee59 JF |
703 | if (!sring) { |
704 | xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring"); | |
705 | return -ENOMEM; | |
706 | } | |
707 | SHARED_RING_INIT(sring); | |
708 | FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE); | |
9e973e64 JA |
709 | |
710 | sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST); | |
9f27ee59 JF |
711 | |
712 | err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring)); | |
713 | if (err < 0) { | |
714 | free_page((unsigned long)sring); | |
715 | info->ring.sring = NULL; | |
716 | goto fail; | |
717 | } | |
718 | info->ring_ref = err; | |
719 | ||
720 | err = xenbus_alloc_evtchn(dev, &info->evtchn); | |
721 | if (err) | |
722 | goto fail; | |
723 | ||
724 | err = bind_evtchn_to_irqhandler(info->evtchn, | |
725 | blkif_interrupt, | |
726 | IRQF_SAMPLE_RANDOM, "blkif", info); | |
727 | if (err <= 0) { | |
728 | xenbus_dev_fatal(dev, err, | |
729 | "bind_evtchn_to_irqhandler failed"); | |
730 | goto fail; | |
731 | } | |
732 | info->irq = err; | |
733 | ||
734 | return 0; | |
735 | fail: | |
736 | blkif_free(info, 0); | |
737 | return err; | |
738 | } | |
739 | ||
740 | ||
741 | /* Common code used when first setting up, and when resuming. */ | |
203fd61f | 742 | static int talk_to_blkback(struct xenbus_device *dev, |
9f27ee59 JF |
743 | struct blkfront_info *info) |
744 | { | |
745 | const char *message = NULL; | |
746 | struct xenbus_transaction xbt; | |
747 | int err; | |
748 | ||
749 | /* Create shared ring, alloc event channel. */ | |
750 | err = setup_blkring(dev, info); | |
751 | if (err) | |
752 | goto out; | |
753 | ||
754 | again: | |
755 | err = xenbus_transaction_start(&xbt); | |
756 | if (err) { | |
757 | xenbus_dev_fatal(dev, err, "starting transaction"); | |
758 | goto destroy_blkring; | |
759 | } | |
760 | ||
761 | err = xenbus_printf(xbt, dev->nodename, | |
762 | "ring-ref", "%u", info->ring_ref); | |
763 | if (err) { | |
764 | message = "writing ring-ref"; | |
765 | goto abort_transaction; | |
766 | } | |
767 | err = xenbus_printf(xbt, dev->nodename, | |
768 | "event-channel", "%u", info->evtchn); | |
769 | if (err) { | |
770 | message = "writing event-channel"; | |
771 | goto abort_transaction; | |
772 | } | |
3e334239 MA |
773 | err = xenbus_printf(xbt, dev->nodename, "protocol", "%s", |
774 | XEN_IO_PROTO_ABI_NATIVE); | |
775 | if (err) { | |
776 | message = "writing protocol"; | |
777 | goto abort_transaction; | |
778 | } | |
9f27ee59 JF |
779 | |
780 | err = xenbus_transaction_end(xbt, 0); | |
781 | if (err) { | |
782 | if (err == -EAGAIN) | |
783 | goto again; | |
784 | xenbus_dev_fatal(dev, err, "completing transaction"); | |
785 | goto destroy_blkring; | |
786 | } | |
787 | ||
788 | xenbus_switch_state(dev, XenbusStateInitialised); | |
789 | ||
790 | return 0; | |
791 | ||
792 | abort_transaction: | |
793 | xenbus_transaction_end(xbt, 1); | |
794 | if (message) | |
795 | xenbus_dev_fatal(dev, err, "%s", message); | |
796 | destroy_blkring: | |
797 | blkif_free(info, 0); | |
798 | out: | |
799 | return err; | |
800 | } | |
801 | ||
9f27ee59 JF |
802 | /** |
803 | * Entry point to this code when a new device is created. Allocate the basic | |
804 | * structures and the ring buffer for communication with the backend, and | |
805 | * inform the backend of the appropriate details for those. Switch to | |
806 | * Initialised state. | |
807 | */ | |
808 | static int blkfront_probe(struct xenbus_device *dev, | |
809 | const struct xenbus_device_id *id) | |
810 | { | |
811 | int err, vdevice, i; | |
812 | struct blkfront_info *info; | |
813 | ||
814 | /* FIXME: Use dynamic device id if this is not set. */ | |
815 | err = xenbus_scanf(XBT_NIL, dev->nodename, | |
816 | "virtual-device", "%i", &vdevice); | |
817 | if (err != 1) { | |
9246b5f0 CL |
818 | /* go looking in the extended area instead */ |
819 | err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext", | |
820 | "%i", &vdevice); | |
821 | if (err != 1) { | |
822 | xenbus_dev_fatal(dev, err, "reading virtual-device"); | |
823 | return err; | |
824 | } | |
9f27ee59 JF |
825 | } |
826 | ||
827 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
828 | if (!info) { | |
829 | xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure"); | |
830 | return -ENOMEM; | |
831 | } | |
832 | ||
b70f5fa0 | 833 | mutex_init(&info->mutex); |
9f27ee59 JF |
834 | info->xbdev = dev; |
835 | info->vdevice = vdevice; | |
836 | info->connected = BLKIF_STATE_DISCONNECTED; | |
837 | INIT_WORK(&info->work, blkif_restart_queue); | |
838 | ||
839 | for (i = 0; i < BLK_RING_SIZE; i++) | |
840 | info->shadow[i].req.id = i+1; | |
841 | info->shadow[BLK_RING_SIZE-1].req.id = 0x0fffffff; | |
842 | ||
843 | /* Front end dir is a number, which is used as the id. */ | |
844 | info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0); | |
a1b4b12b | 845 | dev_set_drvdata(&dev->dev, info); |
9f27ee59 | 846 | |
203fd61f | 847 | err = talk_to_blkback(dev, info); |
9f27ee59 JF |
848 | if (err) { |
849 | kfree(info); | |
a1b4b12b | 850 | dev_set_drvdata(&dev->dev, NULL); |
9f27ee59 JF |
851 | return err; |
852 | } | |
853 | ||
854 | return 0; | |
855 | } | |
856 | ||
857 | ||
858 | static int blkif_recover(struct blkfront_info *info) | |
859 | { | |
860 | int i; | |
861 | struct blkif_request *req; | |
862 | struct blk_shadow *copy; | |
863 | int j; | |
864 | ||
865 | /* Stage 1: Make a safe copy of the shadow state. */ | |
a144ff09 IC |
866 | copy = kmalloc(sizeof(info->shadow), |
867 | GFP_NOIO | __GFP_REPEAT | __GFP_HIGH); | |
9f27ee59 JF |
868 | if (!copy) |
869 | return -ENOMEM; | |
870 | memcpy(copy, info->shadow, sizeof(info->shadow)); | |
871 | ||
872 | /* Stage 2: Set up free list. */ | |
873 | memset(&info->shadow, 0, sizeof(info->shadow)); | |
874 | for (i = 0; i < BLK_RING_SIZE; i++) | |
875 | info->shadow[i].req.id = i+1; | |
876 | info->shadow_free = info->ring.req_prod_pvt; | |
877 | info->shadow[BLK_RING_SIZE-1].req.id = 0x0fffffff; | |
878 | ||
879 | /* Stage 3: Find pending requests and requeue them. */ | |
880 | for (i = 0; i < BLK_RING_SIZE; i++) { | |
881 | /* Not in use? */ | |
882 | if (copy[i].request == 0) | |
883 | continue; | |
884 | ||
885 | /* Grab a request slot and copy shadow state into it. */ | |
886 | req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); | |
887 | *req = copy[i].req; | |
888 | ||
889 | /* We get a new request id, and must reset the shadow state. */ | |
890 | req->id = get_id_from_freelist(info); | |
891 | memcpy(&info->shadow[req->id], ©[i], sizeof(copy[i])); | |
892 | ||
893 | /* Rewrite any grant references invalidated by susp/resume. */ | |
894 | for (j = 0; j < req->nr_segments; j++) | |
895 | gnttab_grant_foreign_access_ref( | |
896 | req->seg[j].gref, | |
897 | info->xbdev->otherend_id, | |
898 | pfn_to_mfn(info->shadow[req->id].frame[j]), | |
899 | rq_data_dir( | |
900 | (struct request *) | |
901 | info->shadow[req->id].request)); | |
902 | info->shadow[req->id].req = *req; | |
903 | ||
904 | info->ring.req_prod_pvt++; | |
905 | } | |
906 | ||
907 | kfree(copy); | |
908 | ||
909 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
910 | ||
911 | spin_lock_irq(&blkif_io_lock); | |
912 | ||
913 | /* Now safe for us to use the shared ring */ | |
914 | info->connected = BLKIF_STATE_CONNECTED; | |
915 | ||
916 | /* Send off requeued requests */ | |
917 | flush_requests(info); | |
918 | ||
919 | /* Kick any other new requests queued since we resumed */ | |
920 | kick_pending_request_queues(info); | |
921 | ||
922 | spin_unlock_irq(&blkif_io_lock); | |
923 | ||
924 | return 0; | |
925 | } | |
926 | ||
927 | /** | |
928 | * We are reconnecting to the backend, due to a suspend/resume, or a backend | |
929 | * driver restart. We tear down our blkif structure and recreate it, but | |
930 | * leave the device-layer structures intact so that this is transparent to the | |
931 | * rest of the kernel. | |
932 | */ | |
933 | static int blkfront_resume(struct xenbus_device *dev) | |
934 | { | |
a1b4b12b | 935 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 JF |
936 | int err; |
937 | ||
938 | dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename); | |
939 | ||
940 | blkif_free(info, info->connected == BLKIF_STATE_CONNECTED); | |
941 | ||
203fd61f | 942 | err = talk_to_blkback(dev, info); |
9f27ee59 JF |
943 | if (info->connected == BLKIF_STATE_SUSPENDED && !err) |
944 | err = blkif_recover(info); | |
945 | ||
946 | return err; | |
947 | } | |
948 | ||
b70f5fa0 DS |
949 | static void |
950 | blkfront_closing(struct blkfront_info *info) | |
951 | { | |
952 | struct xenbus_device *xbdev = info->xbdev; | |
953 | struct block_device *bdev = NULL; | |
954 | ||
955 | mutex_lock(&info->mutex); | |
956 | ||
957 | if (xbdev->state == XenbusStateClosing) { | |
958 | mutex_unlock(&info->mutex); | |
959 | return; | |
960 | } | |
961 | ||
962 | if (info->gd) | |
963 | bdev = bdget_disk(info->gd, 0); | |
964 | ||
965 | mutex_unlock(&info->mutex); | |
966 | ||
967 | if (!bdev) { | |
968 | xenbus_frontend_closed(xbdev); | |
969 | return; | |
970 | } | |
971 | ||
972 | mutex_lock(&bdev->bd_mutex); | |
973 | ||
7b32d104 | 974 | if (bdev->bd_openers) { |
b70f5fa0 DS |
975 | xenbus_dev_error(xbdev, -EBUSY, |
976 | "Device in use; refusing to close"); | |
977 | xenbus_switch_state(xbdev, XenbusStateClosing); | |
978 | } else { | |
979 | xlvbd_release_gendisk(info); | |
980 | xenbus_frontend_closed(xbdev); | |
981 | } | |
982 | ||
983 | mutex_unlock(&bdev->bd_mutex); | |
984 | bdput(bdev); | |
985 | } | |
9f27ee59 JF |
986 | |
987 | /* | |
988 | * Invoked when the backend is finally 'ready' (and has told produced | |
989 | * the details about the physical device - #sectors, size, etc). | |
990 | */ | |
991 | static void blkfront_connect(struct blkfront_info *info) | |
992 | { | |
993 | unsigned long long sectors; | |
994 | unsigned long sector_size; | |
995 | unsigned int binfo; | |
996 | int err; | |
997 | ||
1fa73be6 S |
998 | switch (info->connected) { |
999 | case BLKIF_STATE_CONNECTED: | |
1000 | /* | |
1001 | * Potentially, the back-end may be signalling | |
1002 | * a capacity change; update the capacity. | |
1003 | */ | |
1004 | err = xenbus_scanf(XBT_NIL, info->xbdev->otherend, | |
1005 | "sectors", "%Lu", §ors); | |
1006 | if (XENBUS_EXIST_ERR(err)) | |
1007 | return; | |
1008 | printk(KERN_INFO "Setting capacity to %Lu\n", | |
1009 | sectors); | |
1010 | set_capacity(info->gd, sectors); | |
2def141e | 1011 | revalidate_disk(info->gd); |
1fa73be6 S |
1012 | |
1013 | /* fall through */ | |
1014 | case BLKIF_STATE_SUSPENDED: | |
9f27ee59 | 1015 | return; |
b4dddb49 JF |
1016 | |
1017 | default: | |
1018 | break; | |
1fa73be6 | 1019 | } |
9f27ee59 JF |
1020 | |
1021 | dev_dbg(&info->xbdev->dev, "%s:%s.\n", | |
1022 | __func__, info->xbdev->otherend); | |
1023 | ||
1024 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1025 | "sectors", "%llu", §ors, | |
1026 | "info", "%u", &binfo, | |
1027 | "sector-size", "%lu", §or_size, | |
1028 | NULL); | |
1029 | if (err) { | |
1030 | xenbus_dev_fatal(info->xbdev, err, | |
1031 | "reading backend fields at %s", | |
1032 | info->xbdev->otherend); | |
1033 | return; | |
1034 | } | |
1035 | ||
1036 | err = xenbus_gather(XBT_NIL, info->xbdev->otherend, | |
1037 | "feature-barrier", "%lu", &info->feature_barrier, | |
1038 | NULL); | |
1039 | if (err) | |
1040 | info->feature_barrier = 0; | |
1041 | ||
9246b5f0 | 1042 | err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size); |
9f27ee59 JF |
1043 | if (err) { |
1044 | xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s", | |
1045 | info->xbdev->otherend); | |
1046 | return; | |
1047 | } | |
1048 | ||
1049 | xenbus_switch_state(info->xbdev, XenbusStateConnected); | |
1050 | ||
1051 | /* Kick pending requests. */ | |
1052 | spin_lock_irq(&blkif_io_lock); | |
1053 | info->connected = BLKIF_STATE_CONNECTED; | |
1054 | kick_pending_request_queues(info); | |
1055 | spin_unlock_irq(&blkif_io_lock); | |
1056 | ||
1057 | add_disk(info->gd); | |
1d78d705 CL |
1058 | |
1059 | info->is_ready = 1; | |
9f27ee59 JF |
1060 | } |
1061 | ||
9f27ee59 JF |
1062 | /** |
1063 | * Callback received when the backend's state changes. | |
1064 | */ | |
203fd61f | 1065 | static void blkback_changed(struct xenbus_device *dev, |
9f27ee59 JF |
1066 | enum xenbus_state backend_state) |
1067 | { | |
a1b4b12b | 1068 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
9f27ee59 | 1069 | |
203fd61f | 1070 | dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state); |
9f27ee59 JF |
1071 | |
1072 | switch (backend_state) { | |
1073 | case XenbusStateInitialising: | |
1074 | case XenbusStateInitWait: | |
1075 | case XenbusStateInitialised: | |
1076 | case XenbusStateUnknown: | |
1077 | case XenbusStateClosed: | |
1078 | break; | |
1079 | ||
1080 | case XenbusStateConnected: | |
1081 | blkfront_connect(info); | |
1082 | break; | |
1083 | ||
1084 | case XenbusStateClosing: | |
b70f5fa0 | 1085 | blkfront_closing(info); |
9f27ee59 JF |
1086 | break; |
1087 | } | |
1088 | } | |
1089 | ||
fa1bd359 | 1090 | static int blkfront_remove(struct xenbus_device *xbdev) |
9f27ee59 | 1091 | { |
fa1bd359 DS |
1092 | struct blkfront_info *info = dev_get_drvdata(&xbdev->dev); |
1093 | struct block_device *bdev = NULL; | |
1094 | struct gendisk *disk; | |
9f27ee59 | 1095 | |
fa1bd359 | 1096 | dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename); |
9f27ee59 JF |
1097 | |
1098 | blkif_free(info, 0); | |
1099 | ||
fa1bd359 DS |
1100 | mutex_lock(&info->mutex); |
1101 | ||
1102 | disk = info->gd; | |
1103 | if (disk) | |
1104 | bdev = bdget_disk(disk, 0); | |
1105 | ||
1106 | info->xbdev = NULL; | |
1107 | mutex_unlock(&info->mutex); | |
1108 | ||
1109 | if (!bdev) { | |
1110 | kfree(info); | |
1111 | return 0; | |
1112 | } | |
1113 | ||
1114 | /* | |
1115 | * The xbdev was removed before we reached the Closed | |
1116 | * state. See if it's safe to remove the disk. If the bdev | |
1117 | * isn't closed yet, we let release take care of it. | |
1118 | */ | |
1119 | ||
1120 | mutex_lock(&bdev->bd_mutex); | |
1121 | info = disk->private_data; | |
1122 | ||
7b32d104 | 1123 | if (info && !bdev->bd_openers) { |
fa1bd359 DS |
1124 | xlvbd_release_gendisk(info); |
1125 | disk->private_data = NULL; | |
0e345826 | 1126 | kfree(info); |
fa1bd359 DS |
1127 | } |
1128 | ||
1129 | mutex_unlock(&bdev->bd_mutex); | |
1130 | bdput(bdev); | |
9f27ee59 JF |
1131 | |
1132 | return 0; | |
1133 | } | |
1134 | ||
1d78d705 CL |
1135 | static int blkfront_is_ready(struct xenbus_device *dev) |
1136 | { | |
a1b4b12b | 1137 | struct blkfront_info *info = dev_get_drvdata(&dev->dev); |
1d78d705 | 1138 | |
5d7ed20e | 1139 | return info->is_ready && info->xbdev; |
1d78d705 CL |
1140 | } |
1141 | ||
a63c848b | 1142 | static int blkif_open(struct block_device *bdev, fmode_t mode) |
9f27ee59 | 1143 | { |
13961743 DS |
1144 | struct gendisk *disk = bdev->bd_disk; |
1145 | struct blkfront_info *info; | |
1146 | int err = 0; | |
6e9624b8 AB |
1147 | |
1148 | lock_kernel(); | |
6e9624b8 | 1149 | |
13961743 DS |
1150 | info = disk->private_data; |
1151 | if (!info) { | |
1152 | /* xbdev gone */ | |
1153 | err = -ERESTARTSYS; | |
1154 | goto out; | |
1155 | } | |
1156 | ||
1157 | mutex_lock(&info->mutex); | |
1158 | ||
1159 | if (!info->gd) | |
1160 | /* xbdev is closed */ | |
1161 | err = -ERESTARTSYS; | |
1162 | ||
1163 | mutex_unlock(&info->mutex); | |
1164 | ||
13961743 | 1165 | out: |
7fd152f4 | 1166 | unlock_kernel(); |
13961743 | 1167 | return err; |
9f27ee59 JF |
1168 | } |
1169 | ||
a63c848b | 1170 | static int blkif_release(struct gendisk *disk, fmode_t mode) |
9f27ee59 | 1171 | { |
a63c848b | 1172 | struct blkfront_info *info = disk->private_data; |
7fd152f4 DS |
1173 | struct block_device *bdev; |
1174 | struct xenbus_device *xbdev; | |
1175 | ||
6e9624b8 | 1176 | lock_kernel(); |
7fd152f4 DS |
1177 | |
1178 | bdev = bdget_disk(disk, 0); | |
1179 | bdput(bdev); | |
1180 | ||
acfca3c6 DS |
1181 | if (bdev->bd_openers) |
1182 | goto out; | |
1183 | ||
7fd152f4 DS |
1184 | /* |
1185 | * Check if we have been instructed to close. We will have | |
1186 | * deferred this request, because the bdev was still open. | |
1187 | */ | |
1188 | ||
1189 | mutex_lock(&info->mutex); | |
1190 | xbdev = info->xbdev; | |
1191 | ||
1192 | if (xbdev && xbdev->state == XenbusStateClosing) { | |
1193 | /* pending switch to state closed */ | |
1194 | xlvbd_release_gendisk(info); | |
1195 | xenbus_frontend_closed(info->xbdev); | |
1196 | } | |
1197 | ||
1198 | mutex_unlock(&info->mutex); | |
1199 | ||
1200 | if (!xbdev) { | |
1201 | /* sudden device removal */ | |
1202 | xlvbd_release_gendisk(info); | |
1203 | disk->private_data = NULL; | |
1204 | kfree(info); | |
9f27ee59 | 1205 | } |
7fd152f4 | 1206 | |
6e9624b8 | 1207 | unlock_kernel(); |
9f27ee59 JF |
1208 | return 0; |
1209 | } | |
1210 | ||
83d5cde4 | 1211 | static const struct block_device_operations xlvbd_block_fops = |
9f27ee59 JF |
1212 | { |
1213 | .owner = THIS_MODULE, | |
a63c848b AV |
1214 | .open = blkif_open, |
1215 | .release = blkif_release, | |
597592d9 | 1216 | .getgeo = blkif_getgeo, |
8a6cfeb6 | 1217 | .ioctl = blkif_ioctl, |
9f27ee59 JF |
1218 | }; |
1219 | ||
1220 | ||
ec9c42ec | 1221 | static const struct xenbus_device_id blkfront_ids[] = { |
9f27ee59 JF |
1222 | { "vbd" }, |
1223 | { "" } | |
1224 | }; | |
1225 | ||
1226 | static struct xenbus_driver blkfront = { | |
1227 | .name = "vbd", | |
1228 | .owner = THIS_MODULE, | |
1229 | .ids = blkfront_ids, | |
1230 | .probe = blkfront_probe, | |
1231 | .remove = blkfront_remove, | |
1232 | .resume = blkfront_resume, | |
203fd61f | 1233 | .otherend_changed = blkback_changed, |
1d78d705 | 1234 | .is_ready = blkfront_is_ready, |
9f27ee59 JF |
1235 | }; |
1236 | ||
1237 | static int __init xlblk_init(void) | |
1238 | { | |
6e833587 | 1239 | if (!xen_domain()) |
9f27ee59 JF |
1240 | return -ENODEV; |
1241 | ||
1242 | if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) { | |
1243 | printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n", | |
1244 | XENVBD_MAJOR, DEV_NAME); | |
1245 | return -ENODEV; | |
1246 | } | |
1247 | ||
1248 | return xenbus_register_frontend(&blkfront); | |
1249 | } | |
1250 | module_init(xlblk_init); | |
1251 | ||
1252 | ||
5a60d0cd | 1253 | static void __exit xlblk_exit(void) |
9f27ee59 JF |
1254 | { |
1255 | return xenbus_unregister_driver(&blkfront); | |
1256 | } | |
1257 | module_exit(xlblk_exit); | |
1258 | ||
1259 | MODULE_DESCRIPTION("Xen virtual block device frontend"); | |
1260 | MODULE_LICENSE("GPL"); | |
1261 | MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR); | |
d2f0c52b | 1262 | MODULE_ALIAS("xen:vbd"); |
4f93f09b | 1263 | MODULE_ALIAS("xenblk"); |