blob: 60eed4bdd2e4528ae3c3b8871cd65f85d3c34952 [file] [log] [blame]
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001/*
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>
Ian Campbell597592d2008-02-21 13:03:45 -080040#include <linux/hdreg.h>
Christian Limpach440a01a2008-06-17 10:47:08 +020041#include <linux/cdrom.h>
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070042#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090043#include <linux/slab.h>
Arnd Bergmann2a48fc02010-06-02 14:28:52 +020044#include <linux/mutex.h>
Jens Axboe9e973e62009-02-24 08:10:09 +010045#include <linux/scatterlist.h>
Akinobu Mita34ae2e42012-01-21 00:15:26 +090046#include <linux/bitmap.h>
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070047
Jeremy Fitzhardinge1ccbf532009-10-06 15:11:14 -070048#include <xen/xen.h>
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070049#include <xen/xenbus.h>
50#include <xen/grant_table.h>
51#include <xen/events.h>
52#include <xen/page.h>
Stefano Stabellinic1c54132010-05-14 12:44:30 +010053#include <xen/platform_pci.h>
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070054
55#include <xen/interface/grant_table.h>
56#include <xen/interface/io/blkif.h>
Markus Armbruster3e334232008-04-02 10:54:02 -070057#include <xen/interface/io/protocols.h>
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070058
59#include <asm/xen/hypervisor.h>
60
61enum blkif_state {
62 BLKIF_STATE_DISCONNECTED,
63 BLKIF_STATE_CONNECTED,
64 BLKIF_STATE_SUSPENDED,
65};
66
67struct blk_shadow {
68 struct blkif_request req;
Jeremy Fitzhardingea945b982010-11-01 17:03:14 -040069 struct request *request;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070070 unsigned long frame[BLKIF_MAX_SEGMENTS_PER_REQUEST];
71};
72
Arnd Bergmann2a48fc02010-06-02 14:28:52 +020073static DEFINE_MUTEX(blkfront_mutex);
Alexey Dobriyan83d5cde2009-09-21 17:01:13 -070074static const struct block_device_operations xlvbd_block_fops;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070075
Jeremy Fitzhardinge667c78af2010-12-08 12:39:12 -080076#define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070077
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 */
83struct blkfront_info
84{
Steven Noonan34678112012-02-17 12:04:44 -080085 spinlock_t io_lock;
Daniel Stoddenb70f5fa2010-04-30 22:01:19 +000086 struct mutex mutex;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070087 struct xenbus_device *xbdev;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070088 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;
Jens Axboe9e973e62009-02-24 08:10:09 +010094 struct scatterlist sg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -070095 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;
Tejun Heo4913efe2010-09-03 11:56:16 +0200101 unsigned int feature_flush;
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400102 unsigned int flush_op;
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -0400103 unsigned int feature_discard:1;
104 unsigned int feature_secdiscard:1;
Li Dongyanged30bf32011-09-01 18:39:09 +0800105 unsigned int discard_granularity;
106 unsigned int discard_alignment;
Christian Limpach1d78d702008-04-02 10:54:04 -0700107 int is_ready;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700108};
109
Jan Beulich0e345822010-08-07 18:28:55 +0200110static unsigned int nr_minors;
111static unsigned long *minors;
112static DEFINE_SPINLOCK(minor_lock);
113
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700114#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
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700119#define PARTS_PER_EXT_DISK 256
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700120
121#define BLKIF_MAJOR(dev) ((dev)>>8)
122#define BLKIF_MINOR(dev) ((dev) & 0xff)
123
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700124#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))
Stefano Stabellinic80a4202010-12-02 17:55:00 +0000128#define EMULATED_HD_DISK_MINOR_OFFSET (0)
129#define EMULATED_HD_DISK_NAME_OFFSET (EMULATED_HD_DISK_MINOR_OFFSET / 256)
Stefan Bader196cfe22011-07-14 15:30:22 +0200130#define EMULATED_SD_DISK_MINOR_OFFSET (0)
131#define EMULATED_SD_DISK_NAME_OFFSET (EMULATED_SD_DISK_MINOR_OFFSET / 256)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700132
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700133#define DEV_NAME "xvd" /* name in /dev */
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700134
135static int get_id_from_freelist(struct blkfront_info *info)
136{
137 unsigned long free = info->shadow_free;
Roel Kluinb9ed7252009-05-22 09:25:32 +0200138 BUG_ON(free >= BLK_RING_SIZE);
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -0400139 info->shadow_free = info->shadow[free].req.u.rw.id;
140 info->shadow[free].req.u.rw.id = 0x0fffffee; /* debug */
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700141 return free;
142}
143
144static void add_id_to_freelist(struct blkfront_info *info,
145 unsigned long id)
146{
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -0400147 info->shadow[id].req.u.rw.id = info->shadow_free;
Jeremy Fitzhardingea945b982010-11-01 17:03:14 -0400148 info->shadow[id].request = NULL;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700149 info->shadow_free = id;
150}
151
Jan Beulich0e345822010-08-07 18:28:55 +0200152static int xlbd_reserve_minors(unsigned int minor, unsigned int nr)
153{
154 unsigned int end = minor + nr;
155 int rc;
156
157 if (end > nr_minors) {
158 unsigned long *bitmap, *old;
159
Thomas Meyerf0941482011-11-29 22:08:00 +0100160 bitmap = kcalloc(BITS_TO_LONGS(end), sizeof(*bitmap),
Jan Beulich0e345822010-08-07 18:28:55 +0200161 GFP_KERNEL);
162 if (bitmap == NULL)
163 return -ENOMEM;
164
165 spin_lock(&minor_lock);
166 if (end > nr_minors) {
167 old = minors;
168 memcpy(bitmap, minors,
169 BITS_TO_LONGS(nr_minors) * sizeof(*bitmap));
170 minors = bitmap;
171 nr_minors = BITS_TO_LONGS(end) * BITS_PER_LONG;
172 } else
173 old = bitmap;
174 spin_unlock(&minor_lock);
175 kfree(old);
176 }
177
178 spin_lock(&minor_lock);
179 if (find_next_bit(minors, end, minor) >= end) {
Akinobu Mita34ae2e42012-01-21 00:15:26 +0900180 bitmap_set(minors, minor, nr);
Jan Beulich0e345822010-08-07 18:28:55 +0200181 rc = 0;
182 } else
183 rc = -EBUSY;
184 spin_unlock(&minor_lock);
185
186 return rc;
187}
188
189static void xlbd_release_minors(unsigned int minor, unsigned int nr)
190{
191 unsigned int end = minor + nr;
192
193 BUG_ON(end > nr_minors);
194 spin_lock(&minor_lock);
Akinobu Mita34ae2e42012-01-21 00:15:26 +0900195 bitmap_clear(minors, minor, nr);
Jan Beulich0e345822010-08-07 18:28:55 +0200196 spin_unlock(&minor_lock);
197}
198
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700199static void blkif_restart_queue_callback(void *arg)
200{
201 struct blkfront_info *info = (struct blkfront_info *)arg;
202 schedule_work(&info->work);
203}
204
Harvey Harrisonafe42d72008-04-29 00:59:47 -0700205static int blkif_getgeo(struct block_device *bd, struct hd_geometry *hg)
Ian Campbell597592d2008-02-21 13:03:45 -0800206{
207 /* We don't have real geometry info, but let's at least return
208 values consistent with the size of the device */
209 sector_t nsect = get_capacity(bd->bd_disk);
210 sector_t cylinders = nsect;
211
212 hg->heads = 0xff;
213 hg->sectors = 0x3f;
214 sector_div(cylinders, hg->heads * hg->sectors);
215 hg->cylinders = cylinders;
216 if ((sector_t)(hg->cylinders + 1) * hg->heads * hg->sectors < nsect)
217 hg->cylinders = 0xffff;
218 return 0;
219}
220
Al Viroa63c8482008-03-02 10:23:47 -0500221static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
Adrian Bunk62aa0052008-08-04 11:59:05 +0200222 unsigned command, unsigned long argument)
Christian Limpach440a01a2008-06-17 10:47:08 +0200223{
Al Viroa63c8482008-03-02 10:23:47 -0500224 struct blkfront_info *info = bdev->bd_disk->private_data;
Christian Limpach440a01a2008-06-17 10:47:08 +0200225 int i;
226
227 dev_dbg(&info->xbdev->dev, "command: 0x%x, argument: 0x%lx\n",
228 command, (long)argument);
229
230 switch (command) {
231 case CDROMMULTISESSION:
232 dev_dbg(&info->xbdev->dev, "FIXME: support multisession CDs later\n");
233 for (i = 0; i < sizeof(struct cdrom_multisession); i++)
234 if (put_user(0, (char __user *)(argument + i)))
235 return -EFAULT;
236 return 0;
237
238 case CDROM_GET_CAPABILITY: {
239 struct gendisk *gd = info->gd;
240 if (gd->flags & GENHD_FL_CD)
241 return 0;
242 return -EINVAL;
243 }
244
245 default:
246 /*printk(KERN_ALERT "ioctl %08x not supported by Xen blkdev\n",
247 command);*/
248 return -EINVAL; /* same return as native Linux */
249 }
250
251 return 0;
252}
253
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700254/*
Jeremy Fitzhardingec64e38e2010-11-01 14:32:27 -0400255 * Generate a Xen blkfront IO request from a blk layer request. Reads
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400256 * and writes are handled as expected.
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700257 *
Jeremy Fitzhardingec64e38e2010-11-01 14:32:27 -0400258 * @req: a request struct
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700259 */
260static int blkif_queue_request(struct request *req)
261{
262 struct blkfront_info *info = req->rq_disk->private_data;
263 unsigned long buffer_mfn;
264 struct blkif_request *ring_req;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700265 unsigned long id;
266 unsigned int fsect, lsect;
Jens Axboe9e973e62009-02-24 08:10:09 +0100267 int i, ref;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700268 grant_ref_t gref_head;
Jens Axboe9e973e62009-02-24 08:10:09 +0100269 struct scatterlist *sg;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700270
271 if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
272 return 1;
273
274 if (gnttab_alloc_grant_references(
275 BLKIF_MAX_SEGMENTS_PER_REQUEST, &gref_head) < 0) {
276 gnttab_request_free_callback(
277 &info->callback,
278 blkif_restart_queue_callback,
279 info,
280 BLKIF_MAX_SEGMENTS_PER_REQUEST);
281 return 1;
282 }
283
284 /* Fill out a communications ring structure. */
285 ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
286 id = get_id_from_freelist(info);
Jeremy Fitzhardingea945b982010-11-01 17:03:14 -0400287 info->shadow[id].request = req;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700288
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -0400289 ring_req->u.rw.id = id;
Owen Smith51de6952010-12-22 15:05:00 +0000290 ring_req->u.rw.sector_number = (blkif_sector_t)blk_rq_pos(req);
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -0400291 ring_req->u.rw.handle = info->handle;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700292
293 ring_req->operation = rq_data_dir(req) ?
294 BLKIF_OP_WRITE : BLKIF_OP_READ;
Jeremy Fitzhardingebe2f8372010-11-02 10:38:33 -0400295
296 if (req->cmd_flags & (REQ_FLUSH | REQ_FUA)) {
297 /*
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400298 * Ideally we can do an unordered flush-to-disk. In case the
299 * backend onlysupports barriers, use that. A barrier request
Jeremy Fitzhardingebe2f8372010-11-02 10:38:33 -0400300 * a superset of FUA, so we can implement it the same
301 * way. (It's also a FLUSH+FUA, since it is
302 * guaranteed ordered WRT previous writes.)
303 */
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400304 ring_req->operation = info->flush_op;
Jeremy Fitzhardingebe2f8372010-11-02 10:38:33 -0400305 }
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700306
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -0400307 if (unlikely(req->cmd_flags & (REQ_DISCARD | REQ_SECURE))) {
Li Dongyanged30bf32011-09-01 18:39:09 +0800308 /* id, sector_number and handle are set above. */
309 ring_req->operation = BLKIF_OP_DISCARD;
Li Dongyanged30bf32011-09-01 18:39:09 +0800310 ring_req->u.discard.nr_sectors = blk_rq_sectors(req);
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -0400311 if ((req->cmd_flags & REQ_SECURE) && info->feature_secdiscard)
312 ring_req->u.discard.flag = BLKIF_DISCARD_SECURE;
313 else
314 ring_req->u.discard.flag = 0;
Li Dongyanged30bf32011-09-01 18:39:09 +0800315 } else {
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -0400316 ring_req->u.rw.nr_segments = blk_rq_map_sg(req->q, req,
317 info->sg);
318 BUG_ON(ring_req->u.rw.nr_segments >
319 BLKIF_MAX_SEGMENTS_PER_REQUEST);
Jens Axboe9e973e62009-02-24 08:10:09 +0100320
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -0400321 for_each_sg(info->sg, sg, ring_req->u.rw.nr_segments, i) {
Li Dongyanged30bf32011-09-01 18:39:09 +0800322 buffer_mfn = pfn_to_mfn(page_to_pfn(sg_page(sg)));
323 fsect = sg->offset >> 9;
324 lsect = fsect + (sg->length >> 9) - 1;
325 /* install a grant reference. */
326 ref = gnttab_claim_grant_reference(&gref_head);
327 BUG_ON(ref == -ENOSPC);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700328
Li Dongyanged30bf32011-09-01 18:39:09 +0800329 gnttab_grant_foreign_access_ref(
330 ref,
331 info->xbdev->otherend_id,
332 buffer_mfn,
333 rq_data_dir(req));
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700334
Li Dongyanged30bf32011-09-01 18:39:09 +0800335 info->shadow[id].frame[i] = mfn_to_pfn(buffer_mfn);
336 ring_req->u.rw.seg[i] =
337 (struct blkif_request_segment) {
338 .gref = ref,
339 .first_sect = fsect,
340 .last_sect = lsect };
341 }
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700342 }
343
344 info->ring.req_prod_pvt++;
345
346 /* Keep a private copy so we can reissue requests when recovering. */
347 info->shadow[id].req = *ring_req;
348
349 gnttab_free_grant_references(gref_head);
350
351 return 0;
352}
353
354
355static inline void flush_requests(struct blkfront_info *info)
356{
357 int notify;
358
359 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&info->ring, notify);
360
361 if (notify)
362 notify_remote_via_irq(info->irq);
363}
364
365/*
366 * do_blkif_request
367 * read a block; request is in a request queue
368 */
Jens Axboe165125e2007-07-24 09:28:11 +0200369static void do_blkif_request(struct request_queue *rq)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700370{
371 struct blkfront_info *info = NULL;
372 struct request *req;
373 int queued;
374
375 pr_debug("Entered do_blkif_request\n");
376
377 queued = 0;
378
Tejun Heo9934c8c2009-05-08 11:54:16 +0900379 while ((req = blk_peek_request(rq)) != NULL) {
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700380 info = req->rq_disk->private_data;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700381
382 if (RING_FULL(&info->ring))
383 goto wait;
384
Tejun Heo9934c8c2009-05-08 11:54:16 +0900385 blk_start_request(req);
Tejun Heo296b2f62009-05-08 11:54:15 +0900386
Konrad Rzeszutek Wilkd11e6152011-09-16 15:15:14 -0400387 if ((req->cmd_type != REQ_TYPE_FS) ||
388 ((req->cmd_flags & (REQ_FLUSH | REQ_FUA)) &&
389 !info->flush_op)) {
Tejun Heo296b2f62009-05-08 11:54:15 +0900390 __blk_end_request_all(req, -EIO);
391 continue;
392 }
393
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700394 pr_debug("do_blk_req %p: cmd %p, sec %lx, "
Tejun Heo83096eb2009-05-07 22:24:39 +0900395 "(%u/%u) buffer:%p [%s]\n",
396 req, req->cmd, (unsigned long)blk_rq_pos(req),
397 blk_rq_cur_sectors(req), blk_rq_sectors(req),
398 req->buffer, rq_data_dir(req) ? "write" : "read");
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700399
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700400 if (blkif_queue_request(req)) {
401 blk_requeue_request(rq, req);
402wait:
403 /* Avoid pointless unplugs. */
404 blk_stop_queue(rq);
405 break;
406 }
407
408 queued++;
409 }
410
411 if (queued != 0)
412 flush_requests(info);
413}
414
415static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
416{
Jens Axboe165125e2007-07-24 09:28:11 +0200417 struct request_queue *rq;
Li Dongyanged30bf32011-09-01 18:39:09 +0800418 struct blkfront_info *info = gd->private_data;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700419
Steven Noonan34678112012-02-17 12:04:44 -0800420 rq = blk_init_queue(do_blkif_request, &info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700421 if (rq == NULL)
422 return -1;
423
Fernando Luis Vázquez Cao66d352e2008-10-27 18:45:54 +0900424 queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700425
Li Dongyanged30bf32011-09-01 18:39:09 +0800426 if (info->feature_discard) {
427 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, rq);
428 blk_queue_max_discard_sectors(rq, get_capacity(gd));
429 rq->limits.discard_granularity = info->discard_granularity;
430 rq->limits.discard_alignment = info->discard_alignment;
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -0400431 if (info->feature_secdiscard)
432 queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, rq);
Li Dongyanged30bf32011-09-01 18:39:09 +0800433 }
434
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700435 /* Hard sector size and max sectors impersonate the equiv. hardware. */
Martin K. Petersene1defc42009-05-22 17:17:49 -0400436 blk_queue_logical_block_size(rq, sector_size);
Martin K. Petersen086fa5f2010-02-26 00:20:38 -0500437 blk_queue_max_hw_sectors(rq, 512);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700438
439 /* Each segment in a request is up to an aligned page in size. */
440 blk_queue_segment_boundary(rq, PAGE_SIZE - 1);
441 blk_queue_max_segment_size(rq, PAGE_SIZE);
442
443 /* Ensure a merged request will fit in a single I/O ring slot. */
Martin K. Petersen8a783622010-02-26 00:20:39 -0500444 blk_queue_max_segments(rq, BLKIF_MAX_SEGMENTS_PER_REQUEST);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700445
446 /* Make sure buffer addresses are sector-aligned. */
447 blk_queue_dma_alignment(rq, 511);
448
Ian Campbell1c91fe12008-06-17 10:47:08 +0200449 /* Make sure we don't use bounce buffers. */
450 blk_queue_bounce_limit(rq, BLK_BOUNCE_ANY);
451
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700452 gd->queue = rq;
453
454 return 0;
455}
456
457
Tejun Heo4913efe2010-09-03 11:56:16 +0200458static void xlvbd_flush(struct blkfront_info *info)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700459{
Tejun Heo4913efe2010-09-03 11:56:16 +0200460 blk_queue_flush(info->rq, info->feature_flush);
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400461 printk(KERN_INFO "blkfront: %s: %s: %s\n",
Tejun Heo4913efe2010-09-03 11:56:16 +0200462 info->gd->disk_name,
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400463 info->flush_op == BLKIF_OP_WRITE_BARRIER ?
464 "barrier" : (info->flush_op == BLKIF_OP_FLUSH_DISKCACHE ?
465 "flush diskcache" : "barrier or flush"),
Tejun Heo4913efe2010-09-03 11:56:16 +0200466 info->feature_flush ? "enabled" : "disabled");
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700467}
468
Stefano Stabellinic80a4202010-12-02 17:55:00 +0000469static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset)
470{
471 int major;
472 major = BLKIF_MAJOR(vdevice);
473 *minor = BLKIF_MINOR(vdevice);
474 switch (major) {
475 case XEN_IDE0_MAJOR:
476 *offset = (*minor / 64) + EMULATED_HD_DISK_NAME_OFFSET;
477 *minor = ((*minor / 64) * PARTS_PER_DISK) +
478 EMULATED_HD_DISK_MINOR_OFFSET;
479 break;
480 case XEN_IDE1_MAJOR:
481 *offset = (*minor / 64) + 2 + EMULATED_HD_DISK_NAME_OFFSET;
482 *minor = (((*minor / 64) + 2) * PARTS_PER_DISK) +
483 EMULATED_HD_DISK_MINOR_OFFSET;
484 break;
485 case XEN_SCSI_DISK0_MAJOR:
486 *offset = (*minor / PARTS_PER_DISK) + EMULATED_SD_DISK_NAME_OFFSET;
487 *minor = *minor + EMULATED_SD_DISK_MINOR_OFFSET;
488 break;
489 case XEN_SCSI_DISK1_MAJOR:
490 case XEN_SCSI_DISK2_MAJOR:
491 case XEN_SCSI_DISK3_MAJOR:
492 case XEN_SCSI_DISK4_MAJOR:
493 case XEN_SCSI_DISK5_MAJOR:
494 case XEN_SCSI_DISK6_MAJOR:
495 case XEN_SCSI_DISK7_MAJOR:
496 *offset = (*minor / PARTS_PER_DISK) +
497 ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16) +
498 EMULATED_SD_DISK_NAME_OFFSET;
499 *minor = *minor +
500 ((major - XEN_SCSI_DISK1_MAJOR + 1) * 16 * PARTS_PER_DISK) +
501 EMULATED_SD_DISK_MINOR_OFFSET;
502 break;
503 case XEN_SCSI_DISK8_MAJOR:
504 case XEN_SCSI_DISK9_MAJOR:
505 case XEN_SCSI_DISK10_MAJOR:
506 case XEN_SCSI_DISK11_MAJOR:
507 case XEN_SCSI_DISK12_MAJOR:
508 case XEN_SCSI_DISK13_MAJOR:
509 case XEN_SCSI_DISK14_MAJOR:
510 case XEN_SCSI_DISK15_MAJOR:
511 *offset = (*minor / PARTS_PER_DISK) +
512 ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16) +
513 EMULATED_SD_DISK_NAME_OFFSET;
514 *minor = *minor +
515 ((major - XEN_SCSI_DISK8_MAJOR + 8) * 16 * PARTS_PER_DISK) +
516 EMULATED_SD_DISK_MINOR_OFFSET;
517 break;
518 case XENVBD_MAJOR:
519 *offset = *minor / PARTS_PER_DISK;
520 break;
521 default:
522 printk(KERN_WARNING "blkfront: your disk configuration is "
523 "incorrect, please use an xvd device instead\n");
524 return -ENODEV;
525 }
526 return 0;
527}
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700528
Jan Beuliche77c78c2012-04-05 16:37:22 +0100529static char *encode_disk_name(char *ptr, unsigned int n)
530{
531 if (n >= 26)
532 ptr = encode_disk_name(ptr, n / 26 - 1);
533 *ptr = 'a' + n % 26;
534 return ptr + 1;
535}
536
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700537static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
538 struct blkfront_info *info,
539 u16 vdisk_info, u16 sector_size)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700540{
541 struct gendisk *gd;
542 int nr_minors = 1;
Stefano Stabellinic80a4202010-12-02 17:55:00 +0000543 int err;
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700544 unsigned int offset;
545 int minor;
546 int nr_parts;
Jan Beuliche77c78c2012-04-05 16:37:22 +0100547 char *ptr;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700548
549 BUG_ON(info->gd != NULL);
550 BUG_ON(info->rq != NULL);
551
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700552 if ((info->vdevice>>EXT_SHIFT) > 1) {
553 /* this is above the extended range; something is wrong */
554 printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice);
555 return -ENODEV;
556 }
557
558 if (!VDEV_IS_EXTENDED(info->vdevice)) {
Stefano Stabellinic80a4202010-12-02 17:55:00 +0000559 err = xen_translate_vdev(info->vdevice, &minor, &offset);
560 if (err)
561 return err;
562 nr_parts = PARTS_PER_DISK;
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700563 } else {
564 minor = BLKIF_MINOR_EXT(info->vdevice);
565 nr_parts = PARTS_PER_EXT_DISK;
Stefano Stabellinic80a4202010-12-02 17:55:00 +0000566 offset = minor / nr_parts;
Stefan Bader89153b52011-07-14 15:30:37 +0200567 if (xen_hvm_domain() && offset < EMULATED_HD_DISK_NAME_OFFSET + 4)
Stefano Stabellinic80a4202010-12-02 17:55:00 +0000568 printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with "
569 "emulated IDE disks,\n\t choose an xvd device name"
570 "from xvde on\n", info->vdevice);
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700571 }
Jan Beuliche77c78c2012-04-05 16:37:22 +0100572 if (minor >> MINORBITS) {
573 pr_warn("blkfront: %#x's minor (%#x) out of range; ignoring\n",
574 info->vdevice, minor);
575 return -ENODEV;
576 }
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700577
578 if ((minor % nr_parts) == 0)
579 nr_minors = nr_parts;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700580
Jan Beulich0e345822010-08-07 18:28:55 +0200581 err = xlbd_reserve_minors(minor, nr_minors);
582 if (err)
583 goto out;
584 err = -ENODEV;
585
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700586 gd = alloc_disk(nr_minors);
587 if (gd == NULL)
Jan Beulich0e345822010-08-07 18:28:55 +0200588 goto release;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700589
Jan Beuliche77c78c2012-04-05 16:37:22 +0100590 strcpy(gd->disk_name, DEV_NAME);
591 ptr = encode_disk_name(gd->disk_name + sizeof(DEV_NAME) - 1, offset);
592 BUG_ON(ptr >= gd->disk_name + DISK_NAME_LEN);
593 if (nr_minors > 1)
594 *ptr = 0;
595 else
596 snprintf(ptr, gd->disk_name + DISK_NAME_LEN - ptr,
597 "%d", minor & (nr_parts - 1));
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700598
599 gd->major = XENVBD_MAJOR;
600 gd->first_minor = minor;
601 gd->fops = &xlvbd_block_fops;
602 gd->private_data = info;
603 gd->driverfs_dev = &(info->xbdev->dev);
604 set_capacity(gd, capacity);
605
606 if (xlvbd_init_blk_queue(gd, sector_size)) {
607 del_gendisk(gd);
Jan Beulich0e345822010-08-07 18:28:55 +0200608 goto release;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700609 }
610
611 info->rq = gd->queue;
612 info->gd = gd;
613
Tejun Heo4913efe2010-09-03 11:56:16 +0200614 xlvbd_flush(info);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700615
616 if (vdisk_info & VDISK_READONLY)
617 set_disk_ro(gd, 1);
618
619 if (vdisk_info & VDISK_REMOVABLE)
620 gd->flags |= GENHD_FL_REMOVABLE;
621
622 if (vdisk_info & VDISK_CDROM)
623 gd->flags |= GENHD_FL_CD;
624
625 return 0;
626
Jan Beulich0e345822010-08-07 18:28:55 +0200627 release:
628 xlbd_release_minors(minor, nr_minors);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700629 out:
630 return err;
631}
632
Daniel Stoddena66b5ae2010-08-07 18:33:17 +0200633static void xlvbd_release_gendisk(struct blkfront_info *info)
634{
635 unsigned int minor, nr_minors;
636 unsigned long flags;
637
638 if (info->rq == NULL)
639 return;
640
Steven Noonan34678112012-02-17 12:04:44 -0800641 spin_lock_irqsave(&info->io_lock, flags);
Daniel Stoddena66b5ae2010-08-07 18:33:17 +0200642
643 /* No more blkif_request(). */
644 blk_stop_queue(info->rq);
645
646 /* No more gnttab callback work. */
647 gnttab_cancel_free_callback(&info->callback);
Steven Noonan34678112012-02-17 12:04:44 -0800648 spin_unlock_irqrestore(&info->io_lock, flags);
Daniel Stoddena66b5ae2010-08-07 18:33:17 +0200649
650 /* Flush gnttab callback work. Must be done with no locks held. */
Tejun Heo30d65032010-12-24 15:59:06 +0100651 flush_work_sync(&info->work);
Daniel Stoddena66b5ae2010-08-07 18:33:17 +0200652
653 del_gendisk(info->gd);
654
655 minor = info->gd->first_minor;
656 nr_minors = info->gd->minors;
657 xlbd_release_minors(minor, nr_minors);
658
659 blk_cleanup_queue(info->rq);
660 info->rq = NULL;
661
662 put_disk(info->gd);
663 info->gd = NULL;
664}
665
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700666static void kick_pending_request_queues(struct blkfront_info *info)
667{
668 if (!RING_FULL(&info->ring)) {
669 /* Re-enable calldowns. */
670 blk_start_queue(info->rq);
671 /* Kick things off immediately. */
672 do_blkif_request(info->rq);
673 }
674}
675
676static void blkif_restart_queue(struct work_struct *work)
677{
678 struct blkfront_info *info = container_of(work, struct blkfront_info, work);
679
Steven Noonan34678112012-02-17 12:04:44 -0800680 spin_lock_irq(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700681 if (info->connected == BLKIF_STATE_CONNECTED)
682 kick_pending_request_queues(info);
Steven Noonan34678112012-02-17 12:04:44 -0800683 spin_unlock_irq(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700684}
685
686static void blkif_free(struct blkfront_info *info, int suspend)
687{
688 /* Prevent new requests being issued until we fix things up. */
Steven Noonan34678112012-02-17 12:04:44 -0800689 spin_lock_irq(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700690 info->connected = suspend ?
691 BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED;
692 /* No more blkif_request(). */
693 if (info->rq)
694 blk_stop_queue(info->rq);
695 /* No more gnttab callback work. */
696 gnttab_cancel_free_callback(&info->callback);
Steven Noonan34678112012-02-17 12:04:44 -0800697 spin_unlock_irq(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700698
699 /* Flush gnttab callback work. Must be done with no locks held. */
Tejun Heo30d65032010-12-24 15:59:06 +0100700 flush_work_sync(&info->work);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700701
702 /* Free resources associated with old device channel. */
703 if (info->ring_ref != GRANT_INVALID_REF) {
704 gnttab_end_foreign_access(info->ring_ref, 0,
705 (unsigned long)info->ring.sring);
706 info->ring_ref = GRANT_INVALID_REF;
707 info->ring.sring = NULL;
708 }
709 if (info->irq)
710 unbind_from_irqhandler(info->irq, info);
711 info->evtchn = info->irq = 0;
712
713}
714
715static void blkif_completion(struct blk_shadow *s)
716{
717 int i;
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -0400718 /* Do not let BLKIF_OP_DISCARD as nr_segment is in the same place
719 * flag. */
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -0400720 for (i = 0; i < s->req.u.rw.nr_segments; i++)
Owen Smith51de6952010-12-22 15:05:00 +0000721 gnttab_end_foreign_access(s->req.u.rw.seg[i].gref, 0, 0UL);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700722}
723
724static irqreturn_t blkif_interrupt(int irq, void *dev_id)
725{
726 struct request *req;
727 struct blkif_response *bret;
728 RING_IDX i, rp;
729 unsigned long flags;
730 struct blkfront_info *info = (struct blkfront_info *)dev_id;
Kiyoshi Uedaf530f0362007-12-11 17:47:36 -0500731 int error;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700732
Steven Noonan34678112012-02-17 12:04:44 -0800733 spin_lock_irqsave(&info->io_lock, flags);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700734
735 if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) {
Steven Noonan34678112012-02-17 12:04:44 -0800736 spin_unlock_irqrestore(&info->io_lock, flags);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700737 return IRQ_HANDLED;
738 }
739
740 again:
741 rp = info->ring.sring->rsp_prod;
742 rmb(); /* Ensure we see queued responses up to 'rp'. */
743
744 for (i = info->ring.rsp_cons; i != rp; i++) {
745 unsigned long id;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700746
747 bret = RING_GET_RESPONSE(&info->ring, i);
748 id = bret->id;
Jeremy Fitzhardingea945b982010-11-01 17:03:14 -0400749 req = info->shadow[id].request;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700750
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -0400751 if (bret->operation != BLKIF_OP_DISCARD)
752 blkif_completion(&info->shadow[id]);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700753
754 add_id_to_freelist(info, id);
755
Kiyoshi Uedaf530f0362007-12-11 17:47:36 -0500756 error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700757 switch (bret->operation) {
Li Dongyanged30bf32011-09-01 18:39:09 +0800758 case BLKIF_OP_DISCARD:
759 if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
760 struct request_queue *rq = info->rq;
761 printk(KERN_WARNING "blkfront: %s: discard op failed\n",
762 info->gd->disk_name);
763 error = -EOPNOTSUPP;
764 info->feature_discard = 0;
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -0400765 info->feature_secdiscard = 0;
Li Dongyanged30bf32011-09-01 18:39:09 +0800766 queue_flag_clear(QUEUE_FLAG_DISCARD, rq);
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -0400767 queue_flag_clear(QUEUE_FLAG_SECDISCARD, rq);
Li Dongyanged30bf32011-09-01 18:39:09 +0800768 }
769 __blk_end_request_all(req, error);
770 break;
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400771 case BLKIF_OP_FLUSH_DISKCACHE:
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700772 case BLKIF_OP_WRITE_BARRIER:
773 if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400774 printk(KERN_WARNING "blkfront: %s: write %s op failed\n",
775 info->flush_op == BLKIF_OP_WRITE_BARRIER ?
776 "barrier" : "flush disk cache",
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700777 info->gd->disk_name);
Kiyoshi Uedaf530f0362007-12-11 17:47:36 -0500778 error = -EOPNOTSUPP;
Jeremy Fitzhardingedcb8bae2010-11-02 11:55:58 -0400779 }
780 if (unlikely(bret->status == BLKIF_RSP_ERROR &&
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -0400781 info->shadow[id].req.u.rw.nr_segments == 0)) {
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400782 printk(KERN_WARNING "blkfront: %s: empty write %s op failed\n",
783 info->flush_op == BLKIF_OP_WRITE_BARRIER ?
784 "barrier" : "flush disk cache",
Jeremy Fitzhardingedcb8bae2010-11-02 11:55:58 -0400785 info->gd->disk_name);
786 error = -EOPNOTSUPP;
787 }
788 if (unlikely(error)) {
789 if (error == -EOPNOTSUPP)
790 error = 0;
Tejun Heo4913efe2010-09-03 11:56:16 +0200791 info->feature_flush = 0;
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -0400792 info->flush_op = 0;
Tejun Heo4913efe2010-09-03 11:56:16 +0200793 xlvbd_flush(info);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700794 }
795 /* fall through */
796 case BLKIF_OP_READ:
797 case BLKIF_OP_WRITE:
798 if (unlikely(bret->status != BLKIF_RSP_OKAY))
799 dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
800 "request: %x\n", bret->status);
801
Tejun Heo40cbbb72009-04-23 11:05:19 +0900802 __blk_end_request_all(req, error);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700803 break;
804 default:
805 BUG();
806 }
807 }
808
809 info->ring.rsp_cons = i;
810
811 if (i != info->ring.req_prod_pvt) {
812 int more_to_do;
813 RING_FINAL_CHECK_FOR_RESPONSES(&info->ring, more_to_do);
814 if (more_to_do)
815 goto again;
816 } else
817 info->ring.sring->rsp_event = i + 1;
818
819 kick_pending_request_queues(info);
820
Steven Noonan34678112012-02-17 12:04:44 -0800821 spin_unlock_irqrestore(&info->io_lock, flags);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700822
823 return IRQ_HANDLED;
824}
825
826
827static int setup_blkring(struct xenbus_device *dev,
828 struct blkfront_info *info)
829{
830 struct blkif_sring *sring;
831 int err;
832
833 info->ring_ref = GRANT_INVALID_REF;
834
Ian Campbella144ff02008-06-17 10:47:08 +0200835 sring = (struct blkif_sring *)__get_free_page(GFP_NOIO | __GFP_HIGH);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700836 if (!sring) {
837 xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
838 return -ENOMEM;
839 }
840 SHARED_RING_INIT(sring);
841 FRONT_RING_INIT(&info->ring, sring, PAGE_SIZE);
842
Jens Axboe9e973e62009-02-24 08:10:09 +0100843 sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST);
844
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700845 err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
846 if (err < 0) {
847 free_page((unsigned long)sring);
848 info->ring.sring = NULL;
849 goto fail;
850 }
851 info->ring_ref = err;
852
853 err = xenbus_alloc_evtchn(dev, &info->evtchn);
854 if (err)
855 goto fail;
856
857 err = bind_evtchn_to_irqhandler(info->evtchn,
858 blkif_interrupt,
859 IRQF_SAMPLE_RANDOM, "blkif", info);
860 if (err <= 0) {
861 xenbus_dev_fatal(dev, err,
862 "bind_evtchn_to_irqhandler failed");
863 goto fail;
864 }
865 info->irq = err;
866
867 return 0;
868fail:
869 blkif_free(info, 0);
870 return err;
871}
872
873
874/* Common code used when first setting up, and when resuming. */
Ian Campbell203fd612009-12-04 15:33:54 +0000875static int talk_to_blkback(struct xenbus_device *dev,
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700876 struct blkfront_info *info)
877{
878 const char *message = NULL;
879 struct xenbus_transaction xbt;
880 int err;
881
882 /* Create shared ring, alloc event channel. */
883 err = setup_blkring(dev, info);
884 if (err)
885 goto out;
886
887again:
888 err = xenbus_transaction_start(&xbt);
889 if (err) {
890 xenbus_dev_fatal(dev, err, "starting transaction");
891 goto destroy_blkring;
892 }
893
894 err = xenbus_printf(xbt, dev->nodename,
895 "ring-ref", "%u", info->ring_ref);
896 if (err) {
897 message = "writing ring-ref";
898 goto abort_transaction;
899 }
900 err = xenbus_printf(xbt, dev->nodename,
901 "event-channel", "%u", info->evtchn);
902 if (err) {
903 message = "writing event-channel";
904 goto abort_transaction;
905 }
Markus Armbruster3e334232008-04-02 10:54:02 -0700906 err = xenbus_printf(xbt, dev->nodename, "protocol", "%s",
907 XEN_IO_PROTO_ABI_NATIVE);
908 if (err) {
909 message = "writing protocol";
910 goto abort_transaction;
911 }
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700912
913 err = xenbus_transaction_end(xbt, 0);
914 if (err) {
915 if (err == -EAGAIN)
916 goto again;
917 xenbus_dev_fatal(dev, err, "completing transaction");
918 goto destroy_blkring;
919 }
920
921 xenbus_switch_state(dev, XenbusStateInitialised);
922
923 return 0;
924
925 abort_transaction:
926 xenbus_transaction_end(xbt, 1);
927 if (message)
928 xenbus_dev_fatal(dev, err, "%s", message);
929 destroy_blkring:
930 blkif_free(info, 0);
931 out:
932 return err;
933}
934
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700935/**
936 * Entry point to this code when a new device is created. Allocate the basic
937 * structures and the ring buffer for communication with the backend, and
938 * inform the backend of the appropriate details for those. Switch to
939 * Initialised state.
940 */
941static int blkfront_probe(struct xenbus_device *dev,
942 const struct xenbus_device_id *id)
943{
944 int err, vdevice, i;
945 struct blkfront_info *info;
946
947 /* FIXME: Use dynamic device id if this is not set. */
948 err = xenbus_scanf(XBT_NIL, dev->nodename,
949 "virtual-device", "%i", &vdevice);
950 if (err != 1) {
Chris Lalancette9246b5f2008-09-17 14:30:32 -0700951 /* go looking in the extended area instead */
952 err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext",
953 "%i", &vdevice);
954 if (err != 1) {
955 xenbus_dev_fatal(dev, err, "reading virtual-device");
956 return err;
957 }
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700958 }
959
Stefano Stabellinib98a4092010-07-29 14:53:16 +0100960 if (xen_hvm_domain()) {
961 char *type;
962 int len;
963 /* no unplug has been done: do not hook devices != xen vbds */
Ian Campbell1dc7ce92010-08-23 11:59:29 +0100964 if (xen_platform_pci_unplug & XEN_UNPLUG_UNNECESSARY) {
Stefano Stabellinib98a4092010-07-29 14:53:16 +0100965 int major;
Stefano Stabellinic1c54132010-05-14 12:44:30 +0100966
Stefano Stabellinib98a4092010-07-29 14:53:16 +0100967 if (!VDEV_IS_EXTENDED(vdevice))
968 major = BLKIF_MAJOR(vdevice);
969 else
970 major = XENVBD_MAJOR;
Stefano Stabellinic1c54132010-05-14 12:44:30 +0100971
Stefano Stabellinib98a4092010-07-29 14:53:16 +0100972 if (major != XENVBD_MAJOR) {
973 printk(KERN_INFO
974 "%s: HVM does not support vbd %d as xen block device\n",
975 __FUNCTION__, vdevice);
976 return -ENODEV;
977 }
978 }
979 /* do not create a PV cdrom device if we are an HVM guest */
980 type = xenbus_read(XBT_NIL, dev->nodename, "device-type", &len);
981 if (IS_ERR(type))
982 return -ENODEV;
983 if (strncmp(type, "cdrom", 5) == 0) {
984 kfree(type);
Stefano Stabellinic1c54132010-05-14 12:44:30 +0100985 return -ENODEV;
986 }
Stefano Stabellinib98a4092010-07-29 14:53:16 +0100987 kfree(type);
Stefano Stabellinic1c54132010-05-14 12:44:30 +0100988 }
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700989 info = kzalloc(sizeof(*info), GFP_KERNEL);
990 if (!info) {
991 xenbus_dev_fatal(dev, -ENOMEM, "allocating info structure");
992 return -ENOMEM;
993 }
994
Daniel Stoddenb70f5fa2010-04-30 22:01:19 +0000995 mutex_init(&info->mutex);
Steven Noonan34678112012-02-17 12:04:44 -0800996 spin_lock_init(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -0700997 info->xbdev = dev;
998 info->vdevice = vdevice;
999 info->connected = BLKIF_STATE_DISCONNECTED;
1000 INIT_WORK(&info->work, blkif_restart_queue);
1001
1002 for (i = 0; i < BLK_RING_SIZE; i++)
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -04001003 info->shadow[i].req.u.rw.id = i+1;
1004 info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001005
1006 /* Front end dir is a number, which is used as the id. */
1007 info->handle = simple_strtoul(strrchr(dev->nodename, '/')+1, NULL, 0);
Greg Kroah-Hartmana1b4b122009-04-30 14:43:31 -07001008 dev_set_drvdata(&dev->dev, info);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001009
Ian Campbell203fd612009-12-04 15:33:54 +00001010 err = talk_to_blkback(dev, info);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001011 if (err) {
1012 kfree(info);
Greg Kroah-Hartmana1b4b122009-04-30 14:43:31 -07001013 dev_set_drvdata(&dev->dev, NULL);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001014 return err;
1015 }
1016
1017 return 0;
1018}
1019
1020
1021static int blkif_recover(struct blkfront_info *info)
1022{
1023 int i;
1024 struct blkif_request *req;
1025 struct blk_shadow *copy;
1026 int j;
1027
1028 /* Stage 1: Make a safe copy of the shadow state. */
Ian Campbella144ff02008-06-17 10:47:08 +02001029 copy = kmalloc(sizeof(info->shadow),
1030 GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001031 if (!copy)
1032 return -ENOMEM;
1033 memcpy(copy, info->shadow, sizeof(info->shadow));
1034
1035 /* Stage 2: Set up free list. */
1036 memset(&info->shadow, 0, sizeof(info->shadow));
1037 for (i = 0; i < BLK_RING_SIZE; i++)
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -04001038 info->shadow[i].req.u.rw.id = i+1;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001039 info->shadow_free = info->ring.req_prod_pvt;
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -04001040 info->shadow[BLK_RING_SIZE-1].req.u.rw.id = 0x0fffffff;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001041
1042 /* Stage 3: Find pending requests and requeue them. */
1043 for (i = 0; i < BLK_RING_SIZE; i++) {
1044 /* Not in use? */
Jeremy Fitzhardingea945b982010-11-01 17:03:14 -04001045 if (!copy[i].request)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001046 continue;
1047
1048 /* Grab a request slot and copy shadow state into it. */
1049 req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
1050 *req = copy[i].req;
1051
1052 /* We get a new request id, and must reset the shadow state. */
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -04001053 req->u.rw.id = get_id_from_freelist(info);
1054 memcpy(&info->shadow[req->u.rw.id], &copy[i], sizeof(copy[i]));
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001055
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -04001056 if (req->operation != BLKIF_OP_DISCARD) {
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001057 /* Rewrite any grant references invalidated by susp/resume. */
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -04001058 for (j = 0; j < req->u.rw.nr_segments; j++)
1059 gnttab_grant_foreign_access_ref(
1060 req->u.rw.seg[j].gref,
1061 info->xbdev->otherend_id,
1062 pfn_to_mfn(info->shadow[req->u.rw.id].frame[j]),
1063 rq_data_dir(info->shadow[req->u.rw.id].request));
1064 }
Konrad Rzeszutek Wilk97e36832011-10-12 12:12:36 -04001065 info->shadow[req->u.rw.id].req = *req;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001066
1067 info->ring.req_prod_pvt++;
1068 }
1069
1070 kfree(copy);
1071
1072 xenbus_switch_state(info->xbdev, XenbusStateConnected);
1073
Steven Noonan34678112012-02-17 12:04:44 -08001074 spin_lock_irq(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001075
1076 /* Now safe for us to use the shared ring */
1077 info->connected = BLKIF_STATE_CONNECTED;
1078
1079 /* Send off requeued requests */
1080 flush_requests(info);
1081
1082 /* Kick any other new requests queued since we resumed */
1083 kick_pending_request_queues(info);
1084
Steven Noonan34678112012-02-17 12:04:44 -08001085 spin_unlock_irq(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001086
1087 return 0;
1088}
1089
1090/**
1091 * We are reconnecting to the backend, due to a suspend/resume, or a backend
1092 * driver restart. We tear down our blkif structure and recreate it, but
1093 * leave the device-layer structures intact so that this is transparent to the
1094 * rest of the kernel.
1095 */
1096static int blkfront_resume(struct xenbus_device *dev)
1097{
Greg Kroah-Hartmana1b4b122009-04-30 14:43:31 -07001098 struct blkfront_info *info = dev_get_drvdata(&dev->dev);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001099 int err;
1100
1101 dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename);
1102
1103 blkif_free(info, info->connected == BLKIF_STATE_CONNECTED);
1104
Ian Campbell203fd612009-12-04 15:33:54 +00001105 err = talk_to_blkback(dev, info);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001106 if (info->connected == BLKIF_STATE_SUSPENDED && !err)
1107 err = blkif_recover(info);
1108
1109 return err;
1110}
1111
Daniel Stoddenb70f5fa2010-04-30 22:01:19 +00001112static void
1113blkfront_closing(struct blkfront_info *info)
1114{
1115 struct xenbus_device *xbdev = info->xbdev;
1116 struct block_device *bdev = NULL;
1117
1118 mutex_lock(&info->mutex);
1119
1120 if (xbdev->state == XenbusStateClosing) {
1121 mutex_unlock(&info->mutex);
1122 return;
1123 }
1124
1125 if (info->gd)
1126 bdev = bdget_disk(info->gd, 0);
1127
1128 mutex_unlock(&info->mutex);
1129
1130 if (!bdev) {
1131 xenbus_frontend_closed(xbdev);
1132 return;
1133 }
1134
1135 mutex_lock(&bdev->bd_mutex);
1136
Daniel Stodden7b32d102010-04-30 22:01:23 +00001137 if (bdev->bd_openers) {
Daniel Stoddenb70f5fa2010-04-30 22:01:19 +00001138 xenbus_dev_error(xbdev, -EBUSY,
1139 "Device in use; refusing to close");
1140 xenbus_switch_state(xbdev, XenbusStateClosing);
1141 } else {
1142 xlvbd_release_gendisk(info);
1143 xenbus_frontend_closed(xbdev);
1144 }
1145
1146 mutex_unlock(&bdev->bd_mutex);
1147 bdput(bdev);
1148}
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001149
Li Dongyanged30bf32011-09-01 18:39:09 +08001150static void blkfront_setup_discard(struct blkfront_info *info)
1151{
1152 int err;
1153 char *type;
1154 unsigned int discard_granularity;
1155 unsigned int discard_alignment;
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -04001156 unsigned int discard_secure;
Li Dongyanged30bf32011-09-01 18:39:09 +08001157
1158 type = xenbus_read(XBT_NIL, info->xbdev->otherend, "type", NULL);
1159 if (IS_ERR(type))
1160 return;
1161
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -04001162 info->feature_secdiscard = 0;
Li Dongyanged30bf32011-09-01 18:39:09 +08001163 if (strncmp(type, "phy", 3) == 0) {
1164 err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
1165 "discard-granularity", "%u", &discard_granularity,
1166 "discard-alignment", "%u", &discard_alignment,
1167 NULL);
1168 if (!err) {
1169 info->feature_discard = 1;
1170 info->discard_granularity = discard_granularity;
1171 info->discard_alignment = discard_alignment;
1172 }
Konrad Rzeszutek Wilk5ea42982011-10-12 16:23:30 -04001173 err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
1174 "discard-secure", "%d", &discard_secure,
1175 NULL);
1176 if (!err)
1177 info->feature_secdiscard = discard_secure;
1178
Li Dongyanged30bf32011-09-01 18:39:09 +08001179 } else if (strncmp(type, "file", 4) == 0)
1180 info->feature_discard = 1;
1181
1182 kfree(type);
1183}
1184
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001185/*
1186 * Invoked when the backend is finally 'ready' (and has told produced
1187 * the details about the physical device - #sectors, size, etc).
1188 */
1189static void blkfront_connect(struct blkfront_info *info)
1190{
1191 unsigned long long sectors;
1192 unsigned long sector_size;
1193 unsigned int binfo;
1194 int err;
Li Dongyanged30bf32011-09-01 18:39:09 +08001195 int barrier, flush, discard;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001196
K. Y. Srinivasan1fa73be2010-03-11 13:42:26 -08001197 switch (info->connected) {
1198 case BLKIF_STATE_CONNECTED:
1199 /*
1200 * Potentially, the back-end may be signalling
1201 * a capacity change; update the capacity.
1202 */
1203 err = xenbus_scanf(XBT_NIL, info->xbdev->otherend,
1204 "sectors", "%Lu", &sectors);
1205 if (XENBUS_EXIST_ERR(err))
1206 return;
1207 printk(KERN_INFO "Setting capacity to %Lu\n",
1208 sectors);
1209 set_capacity(info->gd, sectors);
K. Y. Srinivasan2def1412010-03-18 15:00:54 -07001210 revalidate_disk(info->gd);
K. Y. Srinivasan1fa73be2010-03-11 13:42:26 -08001211
1212 /* fall through */
1213 case BLKIF_STATE_SUSPENDED:
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001214 return;
1215
Jeremy Fitzhardingeb4dddb42010-03-11 15:10:40 -08001216 default:
1217 break;
K. Y. Srinivasan1fa73be2010-03-11 13:42:26 -08001218 }
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001219
1220 dev_dbg(&info->xbdev->dev, "%s:%s.\n",
1221 __func__, info->xbdev->otherend);
1222
1223 err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
1224 "sectors", "%llu", &sectors,
1225 "info", "%u", &binfo,
1226 "sector-size", "%lu", &sector_size,
1227 NULL);
1228 if (err) {
1229 xenbus_dev_fatal(info->xbdev, err,
1230 "reading backend fields at %s",
1231 info->xbdev->otherend);
1232 return;
1233 }
1234
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -04001235 info->feature_flush = 0;
1236 info->flush_op = 0;
1237
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001238 err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
Marek Marczykowski4352b472011-05-03 12:04:52 -04001239 "feature-barrier", "%d", &barrier,
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001240 NULL);
Jeremy Fitzhardinge7901d142010-07-28 10:49:29 -07001241
1242 /*
1243 * If there's no "feature-barrier" defined, then it means
1244 * we're dealing with a very old backend which writes
Tejun Heo4913efe2010-09-03 11:56:16 +02001245 * synchronously; nothing to do.
Jeremy Fitzhardinge7901d142010-07-28 10:49:29 -07001246 *
Tejun Heo6958f142010-09-03 11:56:16 +02001247 * If there are barriers, then we use flush.
Jeremy Fitzhardinge7901d142010-07-28 10:49:29 -07001248 */
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -04001249 if (!err && barrier) {
Jeremy Fitzhardingebe2f8372010-11-02 10:38:33 -04001250 info->feature_flush = REQ_FLUSH | REQ_FUA;
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -04001251 info->flush_op = BLKIF_OP_WRITE_BARRIER;
1252 }
1253 /*
1254 * And if there is "feature-flush-cache" use that above
1255 * barriers.
1256 */
1257 err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
1258 "feature-flush-cache", "%d", &flush,
1259 NULL);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001260
Konrad Rzeszutek Wilkedf6ef52011-05-03 12:01:11 -04001261 if (!err && flush) {
1262 info->feature_flush = REQ_FLUSH;
1263 info->flush_op = BLKIF_OP_FLUSH_DISKCACHE;
1264 }
Li Dongyanged30bf32011-09-01 18:39:09 +08001265
1266 err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
1267 "feature-discard", "%d", &discard,
1268 NULL);
1269
1270 if (!err && discard)
1271 blkfront_setup_discard(info);
1272
Chris Lalancette9246b5f2008-09-17 14:30:32 -07001273 err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001274 if (err) {
1275 xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s",
1276 info->xbdev->otherend);
1277 return;
1278 }
1279
1280 xenbus_switch_state(info->xbdev, XenbusStateConnected);
1281
1282 /* Kick pending requests. */
Steven Noonan34678112012-02-17 12:04:44 -08001283 spin_lock_irq(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001284 info->connected = BLKIF_STATE_CONNECTED;
1285 kick_pending_request_queues(info);
Steven Noonan34678112012-02-17 12:04:44 -08001286 spin_unlock_irq(&info->io_lock);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001287
1288 add_disk(info->gd);
Christian Limpach1d78d702008-04-02 10:54:04 -07001289
1290 info->is_ready = 1;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001291}
1292
1293/**
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001294 * Callback received when the backend's state changes.
1295 */
Ian Campbell203fd612009-12-04 15:33:54 +00001296static void blkback_changed(struct xenbus_device *dev,
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001297 enum xenbus_state backend_state)
1298{
Greg Kroah-Hartmana1b4b122009-04-30 14:43:31 -07001299 struct blkfront_info *info = dev_get_drvdata(&dev->dev);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001300
Ian Campbell203fd612009-12-04 15:33:54 +00001301 dev_dbg(&dev->dev, "blkfront:blkback_changed to state %d.\n", backend_state);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001302
1303 switch (backend_state) {
1304 case XenbusStateInitialising:
1305 case XenbusStateInitWait:
1306 case XenbusStateInitialised:
Noboru Iwamatsub78c9512009-10-13 17:22:29 -04001307 case XenbusStateReconfiguring:
1308 case XenbusStateReconfigured:
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001309 case XenbusStateUnknown:
1310 case XenbusStateClosed:
1311 break;
1312
1313 case XenbusStateConnected:
1314 blkfront_connect(info);
1315 break;
1316
1317 case XenbusStateClosing:
Daniel Stoddenb70f5fa2010-04-30 22:01:19 +00001318 blkfront_closing(info);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001319 break;
1320 }
1321}
1322
Daniel Stoddenfa1bd352010-04-30 22:01:22 +00001323static int blkfront_remove(struct xenbus_device *xbdev)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001324{
Daniel Stoddenfa1bd352010-04-30 22:01:22 +00001325 struct blkfront_info *info = dev_get_drvdata(&xbdev->dev);
1326 struct block_device *bdev = NULL;
1327 struct gendisk *disk;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001328
Daniel Stoddenfa1bd352010-04-30 22:01:22 +00001329 dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001330
1331 blkif_free(info, 0);
1332
Daniel Stoddenfa1bd352010-04-30 22:01:22 +00001333 mutex_lock(&info->mutex);
1334
1335 disk = info->gd;
1336 if (disk)
1337 bdev = bdget_disk(disk, 0);
1338
1339 info->xbdev = NULL;
1340 mutex_unlock(&info->mutex);
1341
1342 if (!bdev) {
Jan Beulich0e345822010-08-07 18:28:55 +02001343 kfree(info);
Daniel Stoddenfa1bd352010-04-30 22:01:22 +00001344 return 0;
1345 }
1346
1347 /*
1348 * The xbdev was removed before we reached the Closed
1349 * state. See if it's safe to remove the disk. If the bdev
1350 * isn't closed yet, we let release take care of it.
1351 */
1352
1353 mutex_lock(&bdev->bd_mutex);
1354 info = disk->private_data;
1355
Daniel Stoddend54142c2010-08-07 18:51:21 +02001356 dev_warn(disk_to_dev(disk),
1357 "%s was hot-unplugged, %d stale handles\n",
1358 xbdev->nodename, bdev->bd_openers);
1359
Daniel Stodden7b32d102010-04-30 22:01:23 +00001360 if (info && !bdev->bd_openers) {
Daniel Stoddenfa1bd352010-04-30 22:01:22 +00001361 xlvbd_release_gendisk(info);
1362 disk->private_data = NULL;
1363 kfree(info);
1364 }
1365
1366 mutex_unlock(&bdev->bd_mutex);
1367 bdput(bdev);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001368
1369 return 0;
1370}
1371
Christian Limpach1d78d702008-04-02 10:54:04 -07001372static int blkfront_is_ready(struct xenbus_device *dev)
1373{
Greg Kroah-Hartmana1b4b122009-04-30 14:43:31 -07001374 struct blkfront_info *info = dev_get_drvdata(&dev->dev);
Christian Limpach1d78d702008-04-02 10:54:04 -07001375
Jan Beulich5d7ed202010-08-07 18:31:12 +02001376 return info->is_ready && info->xbdev;
Christian Limpach1d78d702008-04-02 10:54:04 -07001377}
1378
Al Viroa63c8482008-03-02 10:23:47 -05001379static int blkif_open(struct block_device *bdev, fmode_t mode)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001380{
Daniel Stodden13961742010-08-07 18:36:53 +02001381 struct gendisk *disk = bdev->bd_disk;
1382 struct blkfront_info *info;
1383 int err = 0;
Arnd Bergmann6e9624b2010-08-07 18:25:34 +02001384
Arnd Bergmann2a48fc02010-06-02 14:28:52 +02001385 mutex_lock(&blkfront_mutex);
Arnd Bergmann6e9624b2010-08-07 18:25:34 +02001386
Daniel Stodden13961742010-08-07 18:36:53 +02001387 info = disk->private_data;
1388 if (!info) {
1389 /* xbdev gone */
1390 err = -ERESTARTSYS;
1391 goto out;
1392 }
1393
1394 mutex_lock(&info->mutex);
1395
1396 if (!info->gd)
1397 /* xbdev is closed */
1398 err = -ERESTARTSYS;
1399
1400 mutex_unlock(&info->mutex);
1401
Daniel Stodden13961742010-08-07 18:36:53 +02001402out:
Arnd Bergmann2a48fc02010-06-02 14:28:52 +02001403 mutex_unlock(&blkfront_mutex);
Daniel Stodden13961742010-08-07 18:36:53 +02001404 return err;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001405}
1406
Al Viroa63c8482008-03-02 10:23:47 -05001407static int blkif_release(struct gendisk *disk, fmode_t mode)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001408{
Al Viroa63c8482008-03-02 10:23:47 -05001409 struct blkfront_info *info = disk->private_data;
Daniel Stodden7fd152f2010-08-07 18:45:12 +02001410 struct block_device *bdev;
1411 struct xenbus_device *xbdev;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001412
Arnd Bergmann2a48fc02010-06-02 14:28:52 +02001413 mutex_lock(&blkfront_mutex);
Daniel Stodden7fd152f2010-08-07 18:45:12 +02001414
1415 bdev = bdget_disk(disk, 0);
Daniel Stodden7fd152f2010-08-07 18:45:12 +02001416
Daniel Stoddenacfca3c2010-08-07 18:47:26 +02001417 if (bdev->bd_openers)
1418 goto out;
1419
Daniel Stodden7fd152f2010-08-07 18:45:12 +02001420 /*
1421 * Check if we have been instructed to close. We will have
1422 * deferred this request, because the bdev was still open.
1423 */
1424
1425 mutex_lock(&info->mutex);
1426 xbdev = info->xbdev;
1427
1428 if (xbdev && xbdev->state == XenbusStateClosing) {
1429 /* pending switch to state closed */
Daniel Stoddend54142c2010-08-07 18:51:21 +02001430 dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n");
Daniel Stodden7fd152f2010-08-07 18:45:12 +02001431 xlvbd_release_gendisk(info);
1432 xenbus_frontend_closed(info->xbdev);
1433 }
1434
1435 mutex_unlock(&info->mutex);
1436
1437 if (!xbdev) {
1438 /* sudden device removal */
Daniel Stoddend54142c2010-08-07 18:51:21 +02001439 dev_info(disk_to_dev(bdev->bd_disk), "releasing disk\n");
Daniel Stodden7fd152f2010-08-07 18:45:12 +02001440 xlvbd_release_gendisk(info);
1441 disk->private_data = NULL;
1442 kfree(info);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001443 }
Daniel Stodden7fd152f2010-08-07 18:45:12 +02001444
Jens Axboea4cc14e2010-08-08 21:50:05 -04001445out:
Andrew Jonesdad5cf62012-02-16 13:16:25 +01001446 bdput(bdev);
Arnd Bergmann2a48fc02010-06-02 14:28:52 +02001447 mutex_unlock(&blkfront_mutex);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001448 return 0;
1449}
1450
Alexey Dobriyan83d5cde2009-09-21 17:01:13 -07001451static const struct block_device_operations xlvbd_block_fops =
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001452{
1453 .owner = THIS_MODULE,
Al Viroa63c8482008-03-02 10:23:47 -05001454 .open = blkif_open,
1455 .release = blkif_release,
Ian Campbell597592d2008-02-21 13:03:45 -08001456 .getgeo = blkif_getgeo,
Arnd Bergmann8a6cfeb2010-07-08 10:18:46 +02001457 .ioctl = blkif_ioctl,
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001458};
1459
1460
Márton Némethec9c42e2010-01-10 13:39:52 +01001461static const struct xenbus_device_id blkfront_ids[] = {
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001462 { "vbd" },
1463 { "" }
1464};
1465
Jan Beulich73db1442011-12-22 09:08:13 +00001466static DEFINE_XENBUS_DRIVER(blkfront, ,
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001467 .probe = blkfront_probe,
1468 .remove = blkfront_remove,
1469 .resume = blkfront_resume,
Ian Campbell203fd612009-12-04 15:33:54 +00001470 .otherend_changed = blkback_changed,
Christian Limpach1d78d702008-04-02 10:54:04 -07001471 .is_ready = blkfront_is_ready,
Jan Beulich73db1442011-12-22 09:08:13 +00001472);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001473
1474static int __init xlblk_init(void)
1475{
Laszlo Ersek469738e2011-10-07 21:34:38 +02001476 int ret;
1477
Jeremy Fitzhardinge6e833582008-08-19 13:16:17 -07001478 if (!xen_domain())
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001479 return -ENODEV;
1480
Igor Mammedove95ae5a2012-03-27 19:31:08 +02001481 if (xen_hvm_domain() && !xen_platform_pci_unplug)
Igor Mammedovb9136d22012-03-21 15:08:38 +01001482 return -ENODEV;
1483
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001484 if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) {
1485 printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n",
1486 XENVBD_MAJOR, DEV_NAME);
1487 return -ENODEV;
1488 }
1489
Jan Beulich73db1442011-12-22 09:08:13 +00001490 ret = xenbus_register_frontend(&blkfront_driver);
Laszlo Ersek469738e2011-10-07 21:34:38 +02001491 if (ret) {
1492 unregister_blkdev(XENVBD_MAJOR, DEV_NAME);
1493 return ret;
1494 }
1495
1496 return 0;
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001497}
1498module_init(xlblk_init);
1499
1500
Jan Beulich5a60d0c2008-06-17 10:47:08 +02001501static void __exit xlblk_exit(void)
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001502{
Jan Beulich86050672012-04-05 16:04:52 +01001503 xenbus_unregister_driver(&blkfront_driver);
1504 unregister_blkdev(XENVBD_MAJOR, DEV_NAME);
1505 kfree(minors);
Jeremy Fitzhardinge9f27ee52007-07-17 18:37:06 -07001506}
1507module_exit(xlblk_exit);
1508
1509MODULE_DESCRIPTION("Xen virtual block device frontend");
1510MODULE_LICENSE("GPL");
1511MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR);
Mark McLoughlind2f0c522008-04-02 10:54:05 -07001512MODULE_ALIAS("xen:vbd");
Mark McLoughlin4f93f09b2008-04-02 10:54:06 -07001513MODULE_ALIAS("xenblk");