blob: 7f3c09549e4be7364be012d834450215bcd7096f [file] [log] [blame]
Jens Axboe3d6392c2007-07-09 12:38:05 +02001/*
FUJITA Tomonori0c6a89b2007-07-29 23:00:46 +09002 * bsg.c - block layer implementation of the sg v4 interface
Jens Axboe3d6392c2007-07-09 12:38:05 +02003 *
4 * Copyright (C) 2004 Jens Axboe <axboe@suse.de> SUSE Labs
5 * Copyright (C) 2004 Peter M. Jones <pjones@redhat.com>
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License version 2. See the file "COPYING" in the main directory of this
9 * archive for more details.
10 *
11 */
Jens Axboe3d6392c2007-07-09 12:38:05 +020012#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/file.h>
15#include <linux/blkdev.h>
16#include <linux/poll.h>
17#include <linux/cdev.h>
18#include <linux/percpu.h>
19#include <linux/uio.h>
FUJITA Tomonori598443a2007-07-23 09:33:26 +090020#include <linux/idr.h>
Jens Axboe3d6392c2007-07-09 12:38:05 +020021#include <linux/bsg.h>
22
23#include <scsi/scsi.h>
24#include <scsi/scsi_ioctl.h>
25#include <scsi/scsi_cmnd.h>
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +020026#include <scsi/scsi_device.h>
27#include <scsi/scsi_driver.h>
Jens Axboe3d6392c2007-07-09 12:38:05 +020028#include <scsi/sg.h>
29
FUJITA Tomonori0ed081c2007-07-17 12:21:35 +020030#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
31#define BSG_VERSION "0.4"
Jens Axboe3d6392c2007-07-09 12:38:05 +020032
Jens Axboe3d6392c2007-07-09 12:38:05 +020033struct bsg_device {
Jens Axboe165125e2007-07-24 09:28:11 +020034 struct request_queue *queue;
Jens Axboe3d6392c2007-07-09 12:38:05 +020035 spinlock_t lock;
36 struct list_head busy_list;
37 struct list_head done_list;
38 struct hlist_node dev_list;
39 atomic_t ref_count;
40 int minor;
41 int queued_cmds;
42 int done_cmds;
Jens Axboe3d6392c2007-07-09 12:38:05 +020043 wait_queue_head_t wq_done;
44 wait_queue_head_t wq_free;
FUJITA Tomonorid351af02007-07-09 12:40:35 +020045 char name[BUS_ID_SIZE];
Jens Axboe3d6392c2007-07-09 12:38:05 +020046 int max_queue;
47 unsigned long flags;
48};
49
50enum {
51 BSG_F_BLOCK = 1,
52 BSG_F_WRITE_PERM = 2,
53};
54
Jens Axboe5309cb32007-01-23 16:24:41 +010055#define BSG_DEFAULT_CMDS 64
FUJITA Tomonori292b7f22007-03-28 13:29:58 +020056#define BSG_MAX_DEVS 32768
Jens Axboe3d6392c2007-07-09 12:38:05 +020057
58#undef BSG_DEBUG
59
60#ifdef BSG_DEBUG
61#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __FUNCTION__, ##args)
62#else
63#define dprintk(fmt, args...)
64#endif
65
Jens Axboe3d6392c2007-07-09 12:38:05 +020066static DEFINE_MUTEX(bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +090067static DEFINE_IDR(bsg_minor_idr);
Jens Axboe3d6392c2007-07-09 12:38:05 +020068
Jens Axboe25fd1642007-07-17 08:52:29 +020069#define BSG_LIST_ARRAY_SIZE 8
Jens Axboe25fd1642007-07-17 08:52:29 +020070static struct hlist_head bsg_device_list[BSG_LIST_ARRAY_SIZE];
Jens Axboe3d6392c2007-07-09 12:38:05 +020071
72static struct class *bsg_class;
Jens Axboe46f6ef42007-07-17 08:56:10 +020073static int bsg_major;
Jens Axboe3d6392c2007-07-09 12:38:05 +020074
Jens Axboe5309cb32007-01-23 16:24:41 +010075static struct kmem_cache *bsg_cmd_cachep;
76
Jens Axboe3d6392c2007-07-09 12:38:05 +020077/*
78 * our internal command type
79 */
80struct bsg_command {
81 struct bsg_device *bd;
82 struct list_head list;
83 struct request *rq;
84 struct bio *bio;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +020085 struct bio *bidi_bio;
Jens Axboe3d6392c2007-07-09 12:38:05 +020086 int err;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +010087 struct sg_io_v4 hdr;
Jens Axboe3d6392c2007-07-09 12:38:05 +020088 char sense[SCSI_SENSE_BUFFERSIZE];
89};
90
91static void bsg_free_command(struct bsg_command *bc)
92{
93 struct bsg_device *bd = bc->bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +020094 unsigned long flags;
95
Jens Axboe5309cb32007-01-23 16:24:41 +010096 kmem_cache_free(bsg_cmd_cachep, bc);
Jens Axboe3d6392c2007-07-09 12:38:05 +020097
98 spin_lock_irqsave(&bd->lock, flags);
99 bd->queued_cmds--;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200100 spin_unlock_irqrestore(&bd->lock, flags);
101
102 wake_up(&bd->wq_free);
103}
104
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200105static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200106{
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200107 struct bsg_command *bc = ERR_PTR(-EINVAL);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200108
109 spin_lock_irq(&bd->lock);
110
111 if (bd->queued_cmds >= bd->max_queue)
112 goto out;
113
Jens Axboe3d6392c2007-07-09 12:38:05 +0200114 bd->queued_cmds++;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200115 spin_unlock_irq(&bd->lock);
116
Jens Axboe25fd1642007-07-17 08:52:29 +0200117 bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
Jens Axboe5309cb32007-01-23 16:24:41 +0100118 if (unlikely(!bc)) {
119 spin_lock_irq(&bd->lock);
FUJITA Tomonori7e75d732007-01-24 09:05:54 +0100120 bd->queued_cmds--;
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200121 bc = ERR_PTR(-ENOMEM);
FUJITA Tomonori7e75d732007-01-24 09:05:54 +0100122 goto out;
Jens Axboe5309cb32007-01-23 16:24:41 +0100123 }
124
Jens Axboe3d6392c2007-07-09 12:38:05 +0200125 bc->bd = bd;
126 INIT_LIST_HEAD(&bc->list);
Jens Axboe5309cb32007-01-23 16:24:41 +0100127 dprintk("%s: returning free cmd %p\n", bd->name, bc);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200128 return bc;
129out:
Jens Axboe3d6392c2007-07-09 12:38:05 +0200130 spin_unlock_irq(&bd->lock);
131 return bc;
132}
133
FUJITA Tomonori1c1133e2007-07-17 12:21:15 +0200134static inline struct hlist_head *bsg_dev_idx_hash(int index)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200135{
FUJITA Tomonori1c1133e2007-07-17 12:21:15 +0200136 return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
Jens Axboe3d6392c2007-07-09 12:38:05 +0200137}
138
Jens Axboe25fd1642007-07-17 08:52:29 +0200139static int bsg_io_schedule(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200140{
141 DEFINE_WAIT(wait);
142 int ret = 0;
143
144 spin_lock_irq(&bd->lock);
145
146 BUG_ON(bd->done_cmds > bd->queued_cmds);
147
148 /*
149 * -ENOSPC or -ENODATA? I'm going for -ENODATA, meaning "I have no
150 * work to do", even though we return -ENOSPC after this same test
151 * during bsg_write() -- there, it means our buffer can't have more
152 * bsg_commands added to it, thus has no space left.
153 */
154 if (bd->done_cmds == bd->queued_cmds) {
155 ret = -ENODATA;
156 goto unlock;
157 }
158
159 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
160 ret = -EAGAIN;
161 goto unlock;
162 }
163
Jens Axboe25fd1642007-07-17 08:52:29 +0200164 prepare_to_wait(&bd->wq_done, &wait, TASK_UNINTERRUPTIBLE);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200165 spin_unlock_irq(&bd->lock);
166 io_schedule();
167 finish_wait(&bd->wq_done, &wait);
168
Jens Axboe3d6392c2007-07-09 12:38:05 +0200169 return ret;
170unlock:
171 spin_unlock_irq(&bd->lock);
172 return ret;
173}
174
Jens Axboe165125e2007-07-24 09:28:11 +0200175static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100176 struct sg_io_v4 *hdr, int has_write_perm)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200177{
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100178 memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
179
180 if (copy_from_user(rq->cmd, (void *)(unsigned long)hdr->request,
181 hdr->request_len))
182 return -EFAULT;
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200183
184 if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
185 if (blk_verify_command(rq->cmd, has_write_perm))
186 return -EPERM;
187 } else if (!capable(CAP_SYS_RAWIO))
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100188 return -EPERM;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200189
190 /*
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100191 * fill in request structure
Jens Axboe3d6392c2007-07-09 12:38:05 +0200192 */
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100193 rq->cmd_len = hdr->request_len;
194 rq->cmd_type = REQ_TYPE_BLOCK_PC;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200195
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100196 rq->timeout = (hdr->timeout * HZ) / 1000;
197 if (!rq->timeout)
198 rq->timeout = q->sg_timeout;
199 if (!rq->timeout)
200 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200201
202 return 0;
203}
204
205/*
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100206 * Check if sg_io_v4 from user is allowed and valid
207 */
208static int
Jens Axboe165125e2007-07-24 09:28:11 +0200209bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100210{
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200211 int ret = 0;
212
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100213 if (hdr->guard != 'Q')
214 return -EINVAL;
215 if (hdr->request_len > BLK_MAX_CDB)
216 return -EINVAL;
217 if (hdr->dout_xfer_len > (q->max_sectors << 9) ||
218 hdr->din_xfer_len > (q->max_sectors << 9))
219 return -EIO;
220
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200221 switch (hdr->protocol) {
222 case BSG_PROTOCOL_SCSI:
223 switch (hdr->subprotocol) {
224 case BSG_SUB_PROTOCOL_SCSI_CMD:
225 case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
226 break;
227 default:
228 ret = -EINVAL;
229 }
230 break;
231 default:
232 ret = -EINVAL;
233 }
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100234
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100235 *rw = hdr->dout_xfer_len ? WRITE : READ;
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200236 return ret;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100237}
238
239/*
240 * map sg_io_v4 to a request.
Jens Axboe3d6392c2007-07-09 12:38:05 +0200241 */
242static struct request *
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100243bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200244{
Jens Axboe165125e2007-07-24 09:28:11 +0200245 struct request_queue *q = bd->queue;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200246 struct request *rq, *next_rq = NULL;
Jens Axboe25fd1642007-07-17 08:52:29 +0200247 int ret, rw;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100248 unsigned int dxfer_len;
249 void *dxferp = NULL;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200250
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100251 dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
252 hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
253 hdr->din_xfer_len);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200254
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100255 ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200256 if (ret)
257 return ERR_PTR(ret);
258
259 /*
260 * map scatter-gather elements seperately and string them to request
261 */
262 rq = blk_get_request(q, rw, GFP_KERNEL);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200263 if (!rq)
264 return ERR_PTR(-ENOMEM);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100265 ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, test_bit(BSG_F_WRITE_PERM,
266 &bd->flags));
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200267 if (ret)
268 goto out;
269
270 if (rw == WRITE && hdr->din_xfer_len) {
271 if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
272 ret = -EOPNOTSUPP;
273 goto out;
274 }
275
276 next_rq = blk_get_request(q, READ, GFP_KERNEL);
277 if (!next_rq) {
278 ret = -ENOMEM;
279 goto out;
280 }
281 rq->next_rq = next_rq;
James Bottomley40f62022008-01-25 20:05:55 -0600282 next_rq->cmd_type = rq->cmd_type;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200283
284 dxferp = (void*)(unsigned long)hdr->din_xferp;
285 ret = blk_rq_map_user(q, next_rq, dxferp, hdr->din_xfer_len);
286 if (ret)
287 goto out;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200288 }
289
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100290 if (hdr->dout_xfer_len) {
291 dxfer_len = hdr->dout_xfer_len;
292 dxferp = (void*)(unsigned long)hdr->dout_xferp;
293 } else if (hdr->din_xfer_len) {
294 dxfer_len = hdr->din_xfer_len;
295 dxferp = (void*)(unsigned long)hdr->din_xferp;
296 } else
297 dxfer_len = 0;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200298
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100299 if (dxfer_len) {
300 ret = blk_rq_map_user(q, rq, dxferp, dxfer_len);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200301 if (ret)
302 goto out;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200303 }
Jens Axboe3d6392c2007-07-09 12:38:05 +0200304 return rq;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200305out:
306 blk_put_request(rq);
307 if (next_rq) {
308 blk_rq_unmap_user(next_rq->bio);
309 blk_put_request(next_rq);
310 }
311 return ERR_PTR(ret);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200312}
313
314/*
315 * async completion call-back from the block layer, when scsi/ide/whatever
316 * calls end_that_request_last() on a request
317 */
318static void bsg_rq_end_io(struct request *rq, int uptodate)
319{
320 struct bsg_command *bc = rq->end_io_data;
321 struct bsg_device *bd = bc->bd;
322 unsigned long flags;
323
Jens Axboe5309cb32007-01-23 16:24:41 +0100324 dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
325 bd->name, rq, bc, bc->bio, uptodate);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200326
327 bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
328
329 spin_lock_irqsave(&bd->lock, flags);
Jens Axboe25fd1642007-07-17 08:52:29 +0200330 list_move_tail(&bc->list, &bd->done_list);
331 bd->done_cmds++;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200332 spin_unlock_irqrestore(&bd->lock, flags);
Jens Axboe25fd1642007-07-17 08:52:29 +0200333
334 wake_up(&bd->wq_done);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200335}
336
337/*
338 * do final setup of a 'bc' and submit the matching 'rq' to the block
339 * layer for io
340 */
Jens Axboe165125e2007-07-24 09:28:11 +0200341static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200342 struct bsg_command *bc, struct request *rq)
343{
344 rq->sense = bc->sense;
345 rq->sense_len = 0;
346
347 /*
348 * add bc command to busy queue and submit rq for io
349 */
350 bc->rq = rq;
351 bc->bio = rq->bio;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200352 if (rq->next_rq)
353 bc->bidi_bio = rq->next_rq->bio;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200354 bc->hdr.duration = jiffies;
355 spin_lock_irq(&bd->lock);
356 list_add_tail(&bc->list, &bd->busy_list);
357 spin_unlock_irq(&bd->lock);
358
359 dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
360
361 rq->end_io_data = bc;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200362 blk_execute_rq_nowait(q, NULL, rq, 1, bsg_rq_end_io);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200363}
364
Jens Axboe25fd1642007-07-17 08:52:29 +0200365static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200366{
367 struct bsg_command *bc = NULL;
368
369 spin_lock_irq(&bd->lock);
370 if (bd->done_cmds) {
Jens Axboe25fd1642007-07-17 08:52:29 +0200371 bc = list_entry(bd->done_list.next, struct bsg_command, list);
372 list_del(&bc->list);
373 bd->done_cmds--;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200374 }
375 spin_unlock_irq(&bd->lock);
376
377 return bc;
378}
379
380/*
381 * Get a finished command from the done list
382 */
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200383static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200384{
385 struct bsg_command *bc;
386 int ret;
387
388 do {
389 bc = bsg_next_done_cmd(bd);
390 if (bc)
391 break;
392
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200393 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
394 bc = ERR_PTR(-EAGAIN);
395 break;
396 }
397
398 ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200399 if (ret) {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200400 bc = ERR_PTR(-ERESTARTSYS);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200401 break;
402 }
403 } while (1);
404
405 dprintk("%s: returning done %p\n", bd->name, bc);
406
407 return bc;
408}
409
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100410static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200411 struct bio *bio, struct bio *bidi_bio)
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100412{
413 int ret = 0;
414
415 dprintk("rq %p bio %p %u\n", rq, bio, rq->errors);
416 /*
417 * fill in all the output members
418 */
419 hdr->device_status = status_byte(rq->errors);
420 hdr->transport_status = host_byte(rq->errors);
421 hdr->driver_status = driver_byte(rq->errors);
422 hdr->info = 0;
423 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
424 hdr->info |= SG_INFO_CHECK;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100425 hdr->response_len = 0;
426
427 if (rq->sense_len && hdr->response) {
Jens Axboe25fd1642007-07-17 08:52:29 +0200428 int len = min_t(unsigned int, hdr->max_response_len,
429 rq->sense_len);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100430
431 ret = copy_to_user((void*)(unsigned long)hdr->response,
432 rq->sense, len);
433 if (!ret)
434 hdr->response_len = len;
435 else
436 ret = -EFAULT;
437 }
438
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200439 if (rq->next_rq) {
Tejun Heo6b007692008-02-19 11:36:35 +0100440 hdr->dout_resid = rq->raw_data_len;
441 hdr->din_resid = rq->next_rq->raw_data_len;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200442 blk_rq_unmap_user(bidi_bio);
443 blk_put_request(rq->next_rq);
FUJITA Tomonori0c6a89b2007-07-29 23:00:46 +0900444 } else if (rq_data_dir(rq) == READ)
Tejun Heo6b007692008-02-19 11:36:35 +0100445 hdr->din_resid = rq->raw_data_len;
FUJITA Tomonori0c6a89b2007-07-29 23:00:46 +0900446 else
Tejun Heo6b007692008-02-19 11:36:35 +0100447 hdr->dout_resid = rq->raw_data_len;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200448
James Bottomley2d507a02007-12-29 10:59:53 -0600449 /*
450 * If the request generated a negative error number, return it
451 * (providing we aren't already returning an error); if it's
452 * just a protocol response (i.e. non negative), that gets
453 * processed above.
454 */
455 if (!ret && rq->errors < 0)
456 ret = rq->errors;
457
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100458 blk_rq_unmap_user(bio);
459 blk_put_request(rq);
460
461 return ret;
462}
463
Jens Axboe3d6392c2007-07-09 12:38:05 +0200464static int bsg_complete_all_commands(struct bsg_device *bd)
465{
466 struct bsg_command *bc;
467 int ret, tret;
468
469 dprintk("%s: entered\n", bd->name);
470
471 set_bit(BSG_F_BLOCK, &bd->flags);
472
473 /*
474 * wait for all commands to complete
475 */
476 ret = 0;
477 do {
Jens Axboe25fd1642007-07-17 08:52:29 +0200478 ret = bsg_io_schedule(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200479 /*
480 * look for -ENODATA specifically -- we'll sometimes get
481 * -ERESTARTSYS when we've taken a signal, but we can't
482 * return until we're done freeing the queue, so ignore
483 * it. The signal will get handled when we're done freeing
484 * the bsg_device.
485 */
486 } while (ret != -ENODATA);
487
488 /*
489 * discard done commands
490 */
491 ret = 0;
492 do {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200493 spin_lock_irq(&bd->lock);
494 if (!bd->queued_cmds) {
495 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200496 break;
497 }
FUJITA Tomonoriefba1a32007-06-07 13:24:06 +0200498 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200499
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200500 bc = bsg_get_done_cmd(bd);
501 if (IS_ERR(bc))
502 break;
503
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200504 tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
505 bc->bidi_bio);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200506 if (!ret)
507 ret = tret;
508
509 bsg_free_command(bc);
510 } while (1);
511
512 return ret;
513}
514
Jens Axboe25fd1642007-07-17 08:52:29 +0200515static int
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200516__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
517 const struct iovec *iov, ssize_t *bytes_read)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200518{
519 struct bsg_command *bc;
520 int nr_commands, ret;
521
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100522 if (count % sizeof(struct sg_io_v4))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200523 return -EINVAL;
524
525 ret = 0;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100526 nr_commands = count / sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200527 while (nr_commands) {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200528 bc = bsg_get_done_cmd(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200529 if (IS_ERR(bc)) {
530 ret = PTR_ERR(bc);
531 break;
532 }
533
534 /*
535 * this is the only case where we need to copy data back
536 * after completing the request. so do that here,
537 * bsg_complete_work() cannot do that for us
538 */
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200539 ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
540 bc->bidi_bio);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200541
Jens Axboe25fd1642007-07-17 08:52:29 +0200542 if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200543 ret = -EFAULT;
544
545 bsg_free_command(bc);
546
547 if (ret)
548 break;
549
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100550 buf += sizeof(struct sg_io_v4);
551 *bytes_read += sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200552 nr_commands--;
553 }
554
555 return ret;
556}
557
558static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
559{
560 if (file->f_flags & O_NONBLOCK)
561 clear_bit(BSG_F_BLOCK, &bd->flags);
562 else
563 set_bit(BSG_F_BLOCK, &bd->flags);
564}
565
566static inline void bsg_set_write_perm(struct bsg_device *bd, struct file *file)
567{
568 if (file->f_mode & FMODE_WRITE)
569 set_bit(BSG_F_WRITE_PERM, &bd->flags);
570 else
571 clear_bit(BSG_F_WRITE_PERM, &bd->flags);
572}
573
Jens Axboe25fd1642007-07-17 08:52:29 +0200574/*
575 * Check if the error is a "real" error that we should return.
576 */
Jens Axboe3d6392c2007-07-09 12:38:05 +0200577static inline int err_block_err(int ret)
578{
579 if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
580 return 1;
581
582 return 0;
583}
584
585static ssize_t
586bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
587{
588 struct bsg_device *bd = file->private_data;
589 int ret;
590 ssize_t bytes_read;
591
FUJITA Tomonori9e69fbb2006-12-20 11:18:22 +0100592 dprintk("%s: read %Zd bytes\n", bd->name, count);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200593
594 bsg_set_block(bd, file);
595 bytes_read = 0;
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200596 ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200597 *ppos = bytes_read;
598
599 if (!bytes_read || (bytes_read && err_block_err(ret)))
600 bytes_read = ret;
601
602 return bytes_read;
603}
604
Jens Axboe25fd1642007-07-17 08:52:29 +0200605static int __bsg_write(struct bsg_device *bd, const char __user *buf,
606 size_t count, ssize_t *bytes_written)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200607{
608 struct bsg_command *bc;
609 struct request *rq;
610 int ret, nr_commands;
611
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100612 if (count % sizeof(struct sg_io_v4))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200613 return -EINVAL;
614
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100615 nr_commands = count / sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200616 rq = NULL;
617 bc = NULL;
618 ret = 0;
619 while (nr_commands) {
Jens Axboe165125e2007-07-24 09:28:11 +0200620 struct request_queue *q = bd->queue;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200621
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200622 bc = bsg_alloc_command(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200623 if (IS_ERR(bc)) {
624 ret = PTR_ERR(bc);
625 bc = NULL;
626 break;
627 }
628
Jens Axboe3d6392c2007-07-09 12:38:05 +0200629 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
630 ret = -EFAULT;
631 break;
632 }
633
634 /*
635 * get a request, fill in the blanks, and add to request queue
636 */
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100637 rq = bsg_map_hdr(bd, &bc->hdr);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200638 if (IS_ERR(rq)) {
639 ret = PTR_ERR(rq);
640 rq = NULL;
641 break;
642 }
643
644 bsg_add_command(bd, q, bc, rq);
645 bc = NULL;
646 rq = NULL;
647 nr_commands--;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100648 buf += sizeof(struct sg_io_v4);
Jens Axboe25fd1642007-07-17 08:52:29 +0200649 *bytes_written += sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200650 }
651
Jens Axboe3d6392c2007-07-09 12:38:05 +0200652 if (bc)
653 bsg_free_command(bc);
654
655 return ret;
656}
657
658static ssize_t
659bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
660{
661 struct bsg_device *bd = file->private_data;
Jens Axboe25fd1642007-07-17 08:52:29 +0200662 ssize_t bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200663 int ret;
664
FUJITA Tomonori9e69fbb2006-12-20 11:18:22 +0100665 dprintk("%s: write %Zd bytes\n", bd->name, count);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200666
667 bsg_set_block(bd, file);
668 bsg_set_write_perm(bd, file);
669
Jens Axboe25fd1642007-07-17 08:52:29 +0200670 bytes_written = 0;
671 ret = __bsg_write(bd, buf, count, &bytes_written);
672 *ppos = bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200673
674 /*
675 * return bytes written on non-fatal errors
676 */
Jens Axboe25fd1642007-07-17 08:52:29 +0200677 if (!bytes_written || (bytes_written && err_block_err(ret)))
678 bytes_written = ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200679
Jens Axboe25fd1642007-07-17 08:52:29 +0200680 dprintk("%s: returning %Zd\n", bd->name, bytes_written);
681 return bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200682}
683
Jens Axboe3d6392c2007-07-09 12:38:05 +0200684static struct bsg_device *bsg_alloc_device(void)
685{
Jens Axboe3d6392c2007-07-09 12:38:05 +0200686 struct bsg_device *bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200687
688 bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
689 if (unlikely(!bd))
690 return NULL;
691
692 spin_lock_init(&bd->lock);
693
Jens Axboe5309cb32007-01-23 16:24:41 +0100694 bd->max_queue = BSG_DEFAULT_CMDS;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200695
696 INIT_LIST_HEAD(&bd->busy_list);
697 INIT_LIST_HEAD(&bd->done_list);
698 INIT_HLIST_NODE(&bd->dev_list);
699
700 init_waitqueue_head(&bd->wq_free);
701 init_waitqueue_head(&bd->wq_done);
702 return bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200703}
704
705static int bsg_put_device(struct bsg_device *bd)
706{
707 int ret = 0;
708
709 mutex_lock(&bsg_mutex);
710
711 if (!atomic_dec_and_test(&bd->ref_count))
712 goto out;
713
714 dprintk("%s: tearing down\n", bd->name);
715
716 /*
717 * close can always block
718 */
719 set_bit(BSG_F_BLOCK, &bd->flags);
720
721 /*
722 * correct error detection baddies here again. it's the responsibility
723 * of the app to properly reap commands before close() if it wants
724 * fool-proof error detection
725 */
726 ret = bsg_complete_all_commands(bd);
727
728 blk_put_queue(bd->queue);
729 hlist_del(&bd->dev_list);
Jens Axboe5309cb32007-01-23 16:24:41 +0100730 kfree(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200731out:
732 mutex_unlock(&bsg_mutex);
733 return ret;
734}
735
736static struct bsg_device *bsg_add_device(struct inode *inode,
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200737 struct request_queue *rq,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200738 struct file *file)
739{
Jens Axboe25fd1642007-07-17 08:52:29 +0200740 struct bsg_device *bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200741#ifdef BSG_DEBUG
742 unsigned char buf[32];
743#endif
744
745 bd = bsg_alloc_device();
746 if (!bd)
747 return ERR_PTR(-ENOMEM);
748
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200749 bd->queue = rq;
750 kobject_get(&rq->kobj);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200751 bsg_set_block(bd, file);
752
753 atomic_set(&bd->ref_count, 1);
754 bd->minor = iminor(inode);
755 mutex_lock(&bsg_mutex);
FUJITA Tomonori1c1133e2007-07-17 12:21:15 +0200756 hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(bd->minor));
Jens Axboe3d6392c2007-07-09 12:38:05 +0200757
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200758 strncpy(bd->name, rq->bsg_dev.class_dev->class_id, sizeof(bd->name) - 1);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200759 dprintk("bound to <%s>, max queue %d\n",
FUJITA Tomonori9e69fbb2006-12-20 11:18:22 +0100760 format_dev_t(buf, inode->i_rdev), bd->max_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200761
762 mutex_unlock(&bsg_mutex);
763 return bd;
764}
765
766static struct bsg_device *__bsg_get_device(int minor)
767{
Jens Axboe3d6392c2007-07-09 12:38:05 +0200768 struct bsg_device *bd = NULL;
769 struct hlist_node *entry;
770
771 mutex_lock(&bsg_mutex);
772
FUJITA Tomonori1c1133e2007-07-17 12:21:15 +0200773 hlist_for_each(entry, bsg_dev_idx_hash(minor)) {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200774 bd = hlist_entry(entry, struct bsg_device, dev_list);
775 if (bd->minor == minor) {
776 atomic_inc(&bd->ref_count);
777 break;
778 }
779
780 bd = NULL;
781 }
782
783 mutex_unlock(&bsg_mutex);
784 return bd;
785}
786
787static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
788{
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900789 struct bsg_device *bd;
790 struct bsg_class_device *bcd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200791
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900792 bd = __bsg_get_device(iminor(inode));
Jens Axboe3d6392c2007-07-09 12:38:05 +0200793 if (bd)
794 return bd;
795
796 /*
797 * find the class device
798 */
Jens Axboe3d6392c2007-07-09 12:38:05 +0200799 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900800 bcd = idr_find(&bsg_minor_idr, iminor(inode));
Jens Axboe3d6392c2007-07-09 12:38:05 +0200801 mutex_unlock(&bsg_mutex);
802
803 if (!bcd)
804 return ERR_PTR(-ENODEV);
805
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200806 return bsg_add_device(inode, bcd->queue, file);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200807}
808
809static int bsg_open(struct inode *inode, struct file *file)
810{
811 struct bsg_device *bd = bsg_get_device(inode, file);
812
813 if (IS_ERR(bd))
814 return PTR_ERR(bd);
815
816 file->private_data = bd;
817 return 0;
818}
819
820static int bsg_release(struct inode *inode, struct file *file)
821{
822 struct bsg_device *bd = file->private_data;
823
824 file->private_data = NULL;
825 return bsg_put_device(bd);
826}
827
828static unsigned int bsg_poll(struct file *file, poll_table *wait)
829{
830 struct bsg_device *bd = file->private_data;
831 unsigned int mask = 0;
832
833 poll_wait(file, &bd->wq_done, wait);
834 poll_wait(file, &bd->wq_free, wait);
835
836 spin_lock_irq(&bd->lock);
837 if (!list_empty(&bd->done_list))
838 mask |= POLLIN | POLLRDNORM;
839 if (bd->queued_cmds >= bd->max_queue)
840 mask |= POLLOUT;
841 spin_unlock_irq(&bd->lock);
842
843 return mask;
844}
845
Jens Axboe25fd1642007-07-17 08:52:29 +0200846static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200847{
848 struct bsg_device *bd = file->private_data;
849 int __user *uarg = (int __user *) arg;
James Bottomley2d507a02007-12-29 10:59:53 -0600850 int ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200851
Jens Axboe3d6392c2007-07-09 12:38:05 +0200852 switch (cmd) {
853 /*
854 * our own ioctls
855 */
856 case SG_GET_COMMAND_Q:
857 return put_user(bd->max_queue, uarg);
Jens Axboe5309cb32007-01-23 16:24:41 +0100858 case SG_SET_COMMAND_Q: {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200859 int queue;
860
861 if (get_user(queue, uarg))
862 return -EFAULT;
Jens Axboe5309cb32007-01-23 16:24:41 +0100863 if (queue < 1)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200864 return -EINVAL;
865
Jens Axboe5309cb32007-01-23 16:24:41 +0100866 spin_lock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200867 bd->max_queue = queue;
Jens Axboe5309cb32007-01-23 16:24:41 +0100868 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200869 return 0;
870 }
871
872 /*
873 * SCSI/sg ioctls
874 */
875 case SG_GET_VERSION_NUM:
876 case SCSI_IOCTL_GET_IDLUN:
877 case SCSI_IOCTL_GET_BUS_NUMBER:
878 case SG_SET_TIMEOUT:
879 case SG_GET_TIMEOUT:
880 case SG_GET_RESERVED_SIZE:
881 case SG_SET_RESERVED_SIZE:
882 case SG_EMULATED_HOST:
Jens Axboe3d6392c2007-07-09 12:38:05 +0200883 case SCSI_IOCTL_SEND_COMMAND: {
884 void __user *uarg = (void __user *) arg;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200885 return scsi_cmd_ioctl(file, bd->queue, NULL, cmd, uarg);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200886 }
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100887 case SG_IO: {
888 struct request *rq;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200889 struct bio *bio, *bidi_bio = NULL;
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100890 struct sg_io_v4 hdr;
891
892 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
893 return -EFAULT;
894
895 rq = bsg_map_hdr(bd, &hdr);
896 if (IS_ERR(rq))
897 return PTR_ERR(rq);
898
899 bio = rq->bio;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200900 if (rq->next_rq)
901 bidi_bio = rq->next_rq->bio;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200902 blk_execute_rq(bd->queue, NULL, rq, 0);
James Bottomley2d507a02007-12-29 10:59:53 -0600903 ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100904
905 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
906 return -EFAULT;
Jens Axboeb711afa2006-12-20 11:25:23 +0100907
James Bottomley2d507a02007-12-29 10:59:53 -0600908 return ret;
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100909 }
Jens Axboe3d6392c2007-07-09 12:38:05 +0200910 /*
911 * block device ioctls
912 */
913 default:
914#if 0
915 return ioctl_by_bdev(bd->bdev, cmd, arg);
916#else
917 return -ENOTTY;
918#endif
919 }
920}
921
Arjan van de Ven7344be02007-10-15 11:01:53 +0200922static const struct file_operations bsg_fops = {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200923 .read = bsg_read,
924 .write = bsg_write,
925 .poll = bsg_poll,
926 .open = bsg_open,
927 .release = bsg_release,
Jens Axboe25fd1642007-07-17 08:52:29 +0200928 .unlocked_ioctl = bsg_ioctl,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200929 .owner = THIS_MODULE,
930};
931
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200932void bsg_unregister_queue(struct request_queue *q)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200933{
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200934 struct bsg_class_device *bcd = &q->bsg_dev;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200935
FUJITA Tomonoridf468822007-07-21 13:23:25 +0900936 if (!bcd->class_dev)
937 return;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200938
939 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900940 idr_remove(&bsg_minor_idr, bcd->minor);
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200941 sysfs_remove_link(&q->kobj, "bsg");
James Bottomley39dca552007-07-20 18:22:17 -0500942 class_device_unregister(bcd->class_dev);
943 put_device(bcd->dev);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200944 bcd->class_dev = NULL;
James Bottomley39dca552007-07-20 18:22:17 -0500945 bcd->dev = NULL;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200946 mutex_unlock(&bsg_mutex);
947}
FUJITA Tomonori4cf07232007-03-30 11:19:39 +0200948EXPORT_SYMBOL_GPL(bsg_unregister_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200949
James Bottomley39dca552007-07-20 18:22:17 -0500950int bsg_register_queue(struct request_queue *q, struct device *gdev,
951 const char *name)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200952{
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900953 struct bsg_class_device *bcd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200954 dev_t dev;
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900955 int ret, minor;
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +0200956 struct class_device *class_dev = NULL;
James Bottomley39dca552007-07-20 18:22:17 -0500957 const char *devname;
958
959 if (name)
960 devname = name;
961 else
962 devname = gdev->bus_id;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200963
964 /*
965 * we need a proper transport to send commands, not a stacked device
966 */
967 if (!q->request_fn)
968 return 0;
969
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200970 bcd = &q->bsg_dev;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200971 memset(bcd, 0, sizeof(*bcd));
Jens Axboe3d6392c2007-07-09 12:38:05 +0200972
973 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900974
975 ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
976 if (!ret) {
977 ret = -ENOMEM;
978 goto unlock;
979 }
980
981 ret = idr_get_new(&bsg_minor_idr, bcd, &minor);
982 if (ret < 0)
983 goto unlock;
984
985 if (minor >= BSG_MAX_DEVS) {
FUJITA Tomonori292b7f22007-03-28 13:29:58 +0200986 printk(KERN_ERR "bsg: too many bsg devices\n");
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900987 ret = -EINVAL;
988 goto remove_idr;
FUJITA Tomonori292b7f22007-03-28 13:29:58 +0200989 }
990
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900991 bcd->minor = minor;
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200992 bcd->queue = q;
James Bottomley39dca552007-07-20 18:22:17 -0500993 bcd->dev = get_device(gdev);
Jens Axboe46f6ef42007-07-17 08:56:10 +0200994 dev = MKDEV(bsg_major, bcd->minor);
James Bottomley39dca552007-07-20 18:22:17 -0500995 class_dev = class_device_create(bsg_class, NULL, dev, gdev, "%s",
996 devname);
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +0200997 if (IS_ERR(class_dev)) {
998 ret = PTR_ERR(class_dev);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900999 goto put_dev;
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001000 }
1001 bcd->class_dev = class_dev;
1002
Linus Torvaldsabce8912007-07-16 11:18:23 -07001003 if (q->kobj.sd) {
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001004 ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
1005 if (ret)
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001006 goto unregister_class_dev;
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001007 }
1008
Jens Axboe3d6392c2007-07-09 12:38:05 +02001009 mutex_unlock(&bsg_mutex);
1010 return 0;
James Bottomley6826ee42007-07-20 16:50:10 -05001011
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001012unregister_class_dev:
James Bottomley6826ee42007-07-20 16:50:10 -05001013 class_device_unregister(class_dev);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001014put_dev:
James Bottomley39dca552007-07-20 18:22:17 -05001015 put_device(gdev);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001016remove_idr:
1017 idr_remove(&bsg_minor_idr, minor);
1018unlock:
Jens Axboe264a0472007-01-23 16:30:17 +01001019 mutex_unlock(&bsg_mutex);
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001020 return ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001021}
FUJITA Tomonori4cf07232007-03-30 11:19:39 +02001022EXPORT_SYMBOL_GPL(bsg_register_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001023
Greg Kroah-Hartman7e7654a2007-09-12 15:06:57 -07001024static struct cdev bsg_cdev;
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001025
Jens Axboe3d6392c2007-07-09 12:38:05 +02001026static int __init bsg_init(void)
1027{
1028 int ret, i;
Jens Axboe46f6ef42007-07-17 08:56:10 +02001029 dev_t devid;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001030
Jens Axboe5309cb32007-01-23 16:24:41 +01001031 bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
Paul Mundt20c2df82007-07-20 10:11:58 +09001032 sizeof(struct bsg_command), 0, 0, NULL);
Jens Axboe5309cb32007-01-23 16:24:41 +01001033 if (!bsg_cmd_cachep) {
1034 printk(KERN_ERR "bsg: failed creating slab cache\n");
1035 return -ENOMEM;
1036 }
1037
Jens Axboe25fd1642007-07-17 08:52:29 +02001038 for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
Jens Axboe3d6392c2007-07-09 12:38:05 +02001039 INIT_HLIST_HEAD(&bsg_device_list[i]);
1040
1041 bsg_class = class_create(THIS_MODULE, "bsg");
Jens Axboe5309cb32007-01-23 16:24:41 +01001042 if (IS_ERR(bsg_class)) {
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001043 ret = PTR_ERR(bsg_class);
1044 goto destroy_kmemcache;
Jens Axboe5309cb32007-01-23 16:24:41 +01001045 }
Jens Axboe3d6392c2007-07-09 12:38:05 +02001046
Jens Axboe46f6ef42007-07-17 08:56:10 +02001047 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001048 if (ret)
1049 goto destroy_bsg_class;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001050
Jens Axboe46f6ef42007-07-17 08:56:10 +02001051 bsg_major = MAJOR(devid);
1052
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001053 cdev_init(&bsg_cdev, &bsg_fops);
Jens Axboe46f6ef42007-07-17 08:56:10 +02001054 ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001055 if (ret)
1056 goto unregister_chrdev;
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001057
Jens Axboe5d3a8cd2007-07-17 15:10:09 +02001058 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
FUJITA Tomonori0ed081c2007-07-17 12:21:35 +02001059 " loaded (major %d)\n", bsg_major);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001060 return 0;
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001061unregister_chrdev:
1062 unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1063destroy_bsg_class:
1064 class_destroy(bsg_class);
1065destroy_kmemcache:
1066 kmem_cache_destroy(bsg_cmd_cachep);
1067 return ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001068}
1069
1070MODULE_AUTHOR("Jens Axboe");
FUJITA Tomonori0ed081c2007-07-17 12:21:35 +02001071MODULE_DESCRIPTION(BSG_DESCRIPTION);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001072MODULE_LICENSE("GPL");
1073
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001074device_initcall(bsg_init);