blob: ff64ae3bacee90c7ad93cd4859772003f8079cb4 [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>
Randy Dunlapad5ebd22009-11-11 13:47:45 +010018#include <linux/jiffies.h>
Jens Axboe3d6392c2007-07-09 12:38:05 +020019#include <linux/percpu.h>
20#include <linux/uio.h>
FUJITA Tomonori598443a2007-07-23 09:33:26 +090021#include <linux/idr.h>
Jens Axboe3d6392c2007-07-09 12:38:05 +020022#include <linux/bsg.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Jens Axboe3d6392c2007-07-09 12:38:05 +020024
25#include <scsi/scsi.h>
26#include <scsi/scsi_ioctl.h>
27#include <scsi/scsi_cmnd.h>
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +020028#include <scsi/scsi_device.h>
29#include <scsi/scsi_driver.h>
Jens Axboe3d6392c2007-07-09 12:38:05 +020030#include <scsi/sg.h>
31
FUJITA Tomonori0ed081c2007-07-17 12:21:35 +020032#define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
33#define BSG_VERSION "0.4"
Jens Axboe3d6392c2007-07-09 12:38:05 +020034
Jens Axboe3d6392c2007-07-09 12:38:05 +020035struct bsg_device {
Jens Axboe165125e2007-07-24 09:28:11 +020036 struct request_queue *queue;
Jens Axboe3d6392c2007-07-09 12:38:05 +020037 spinlock_t lock;
38 struct list_head busy_list;
39 struct list_head done_list;
40 struct hlist_node dev_list;
41 atomic_t ref_count;
Jens Axboe3d6392c2007-07-09 12:38:05 +020042 int queued_cmds;
43 int done_cmds;
Jens Axboe3d6392c2007-07-09 12:38:05 +020044 wait_queue_head_t wq_done;
45 wait_queue_head_t wq_free;
Kay Sievers3ada8b72009-01-06 10:44:43 -080046 char name[20];
Jens Axboe3d6392c2007-07-09 12:38:05 +020047 int max_queue;
48 unsigned long flags;
49};
50
51enum {
52 BSG_F_BLOCK = 1,
Jens Axboe3d6392c2007-07-09 12:38:05 +020053};
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
Harvey Harrison24c03d42008-05-01 04:35:17 -070061#define dprintk(fmt, args...) printk(KERN_ERR "%s: " fmt, __func__, ##args)
Jens Axboe3d6392c2007-07-09 12:38:05 +020062#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 Tomonoriabf54392008-08-16 14:10:05 +0900176 struct sg_io_v4 *hdr, struct bsg_device *bd,
Al Viroaeb5d722008-09-02 15:28:45 -0400177 fmode_t has_write_perm)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200178{
FUJITA Tomonori9f5de6b2008-04-30 13:16:21 +0900179 if (hdr->request_len > BLK_MAX_CDB) {
180 rq->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
181 if (!rq->cmd)
182 return -ENOMEM;
183 }
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100184
Namhyung Kim2b727c62011-06-20 13:27:45 +0200185 if (copy_from_user(rq->cmd, (void __user *)(unsigned long)hdr->request,
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100186 hdr->request_len))
187 return -EFAULT;
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200188
189 if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
Jens Axboe018e0442009-06-26 16:27:10 +0200190 if (blk_verify_command(rq->cmd, has_write_perm))
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200191 return -EPERM;
192 } else if (!capable(CAP_SYS_RAWIO))
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100193 return -EPERM;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200194
195 /*
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100196 * fill in request structure
Jens Axboe3d6392c2007-07-09 12:38:05 +0200197 */
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100198 rq->cmd_len = hdr->request_len;
199 rq->cmd_type = REQ_TYPE_BLOCK_PC;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200200
Randy Dunlapad5ebd22009-11-11 13:47:45 +0100201 rq->timeout = msecs_to_jiffies(hdr->timeout);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100202 if (!rq->timeout)
203 rq->timeout = q->sg_timeout;
204 if (!rq->timeout)
205 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
Linus Torvaldsf2f1fa72008-12-05 14:49:18 -0800206 if (rq->timeout < BLK_MIN_SG_TIMEOUT)
207 rq->timeout = BLK_MIN_SG_TIMEOUT;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200208
209 return 0;
210}
211
212/*
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100213 * Check if sg_io_v4 from user is allowed and valid
214 */
215static int
Jens Axboe165125e2007-07-24 09:28:11 +0200216bsg_validate_sgv4_hdr(struct request_queue *q, struct sg_io_v4 *hdr, int *rw)
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100217{
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200218 int ret = 0;
219
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100220 if (hdr->guard != 'Q')
221 return -EINVAL;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100222
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200223 switch (hdr->protocol) {
224 case BSG_PROTOCOL_SCSI:
225 switch (hdr->subprotocol) {
226 case BSG_SUB_PROTOCOL_SCSI_CMD:
227 case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
228 break;
229 default:
230 ret = -EINVAL;
231 }
232 break;
233 default:
234 ret = -EINVAL;
235 }
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100236
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100237 *rw = hdr->dout_xfer_len ? WRITE : READ;
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200238 return ret;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100239}
240
241/*
242 * map sg_io_v4 to a request.
Jens Axboe3d6392c2007-07-09 12:38:05 +0200243 */
244static struct request *
Boaz Harroshc1c201202009-02-03 07:47:29 +0100245bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm,
246 u8 *sense)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200247{
Jens Axboe165125e2007-07-24 09:28:11 +0200248 struct request_queue *q = bd->queue;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200249 struct request *rq, *next_rq = NULL;
Jens Axboe25fd1642007-07-17 08:52:29 +0200250 int ret, rw;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100251 unsigned int dxfer_len;
Namhyung Kim2b727c62011-06-20 13:27:45 +0200252 void __user *dxferp = NULL;
James Smartc7a841f2010-11-14 11:12:04 -0500253 struct bsg_class_device *bcd = &q->bsg_dev;
254
255 /* if the LLD has been removed then the bsg_unregister_queue will
256 * eventually be called and the class_dev was freed, so we can no
257 * longer use this request_queue. Return no such address.
258 */
259 if (!bcd->class_dev)
260 return ERR_PTR(-ENXIO);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200261
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100262 dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
263 hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
264 hdr->din_xfer_len);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200265
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100266 ret = bsg_validate_sgv4_hdr(q, hdr, &rw);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200267 if (ret)
268 return ERR_PTR(ret);
269
270 /*
Daniel Mack3ad2f3f2010-02-03 08:01:28 +0800271 * map scatter-gather elements separately and string them to request
Jens Axboe3d6392c2007-07-09 12:38:05 +0200272 */
273 rq = blk_get_request(q, rw, GFP_KERNEL);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200274 if (!rq)
275 return ERR_PTR(-ENOMEM);
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900276 ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200277 if (ret)
278 goto out;
279
280 if (rw == WRITE && hdr->din_xfer_len) {
281 if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
282 ret = -EOPNOTSUPP;
283 goto out;
284 }
285
286 next_rq = blk_get_request(q, READ, GFP_KERNEL);
287 if (!next_rq) {
288 ret = -ENOMEM;
289 goto out;
290 }
291 rq->next_rq = next_rq;
James Bottomley40f62022008-01-25 20:05:55 -0600292 next_rq->cmd_type = rq->cmd_type;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200293
Namhyung Kim2b727c62011-06-20 13:27:45 +0200294 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900295 ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
296 hdr->din_xfer_len, GFP_KERNEL);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200297 if (ret)
298 goto out;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200299 }
300
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100301 if (hdr->dout_xfer_len) {
302 dxfer_len = hdr->dout_xfer_len;
Namhyung Kim2b727c62011-06-20 13:27:45 +0200303 dxferp = (void __user *)(unsigned long)hdr->dout_xferp;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100304 } else if (hdr->din_xfer_len) {
305 dxfer_len = hdr->din_xfer_len;
Namhyung Kim2b727c62011-06-20 13:27:45 +0200306 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100307 } else
308 dxfer_len = 0;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200309
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100310 if (dxfer_len) {
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900311 ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
312 GFP_KERNEL);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200313 if (ret)
314 goto out;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200315 }
Boaz Harroshc1c201202009-02-03 07:47:29 +0100316
317 rq->sense = sense;
318 rq->sense_len = 0;
319
Jens Axboe3d6392c2007-07-09 12:38:05 +0200320 return rq;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200321out:
FUJITA Tomonori9f5de6b2008-04-30 13:16:21 +0900322 if (rq->cmd != rq->__cmd)
323 kfree(rq->cmd);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200324 blk_put_request(rq);
325 if (next_rq) {
326 blk_rq_unmap_user(next_rq->bio);
327 blk_put_request(next_rq);
328 }
329 return ERR_PTR(ret);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200330}
331
332/*
333 * async completion call-back from the block layer, when scsi/ide/whatever
334 * calls end_that_request_last() on a request
335 */
336static void bsg_rq_end_io(struct request *rq, int uptodate)
337{
338 struct bsg_command *bc = rq->end_io_data;
339 struct bsg_device *bd = bc->bd;
340 unsigned long flags;
341
Jens Axboe5309cb32007-01-23 16:24:41 +0100342 dprintk("%s: finished rq %p bc %p, bio %p stat %d\n",
343 bd->name, rq, bc, bc->bio, uptodate);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200344
345 bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
346
347 spin_lock_irqsave(&bd->lock, flags);
Jens Axboe25fd1642007-07-17 08:52:29 +0200348 list_move_tail(&bc->list, &bd->done_list);
349 bd->done_cmds++;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200350 spin_unlock_irqrestore(&bd->lock, flags);
Jens Axboe25fd1642007-07-17 08:52:29 +0200351
352 wake_up(&bd->wq_done);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200353}
354
355/*
356 * do final setup of a 'bc' and submit the matching 'rq' to the block
357 * layer for io
358 */
Jens Axboe165125e2007-07-24 09:28:11 +0200359static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200360 struct bsg_command *bc, struct request *rq)
361{
Boaz Harrosh05378942009-03-24 12:23:40 +0100362 int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
363
Jens Axboe3d6392c2007-07-09 12:38:05 +0200364 /*
365 * add bc command to busy queue and submit rq for io
366 */
367 bc->rq = rq;
368 bc->bio = rq->bio;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200369 if (rq->next_rq)
370 bc->bidi_bio = rq->next_rq->bio;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200371 bc->hdr.duration = jiffies;
372 spin_lock_irq(&bd->lock);
373 list_add_tail(&bc->list, &bd->busy_list);
374 spin_unlock_irq(&bd->lock);
375
376 dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
377
378 rq->end_io_data = bc;
Boaz Harrosh05378942009-03-24 12:23:40 +0100379 blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200380}
381
Jens Axboe25fd1642007-07-17 08:52:29 +0200382static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200383{
384 struct bsg_command *bc = NULL;
385
386 spin_lock_irq(&bd->lock);
387 if (bd->done_cmds) {
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900388 bc = list_first_entry(&bd->done_list, struct bsg_command, list);
Jens Axboe25fd1642007-07-17 08:52:29 +0200389 list_del(&bc->list);
390 bd->done_cmds--;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200391 }
392 spin_unlock_irq(&bd->lock);
393
394 return bc;
395}
396
397/*
398 * Get a finished command from the done list
399 */
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200400static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200401{
402 struct bsg_command *bc;
403 int ret;
404
405 do {
406 bc = bsg_next_done_cmd(bd);
407 if (bc)
408 break;
409
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200410 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
411 bc = ERR_PTR(-EAGAIN);
412 break;
413 }
414
415 ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200416 if (ret) {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200417 bc = ERR_PTR(-ERESTARTSYS);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200418 break;
419 }
420 } while (1);
421
422 dprintk("%s: returning done %p\n", bd->name, bc);
423
424 return bc;
425}
426
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100427static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200428 struct bio *bio, struct bio *bidi_bio)
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100429{
430 int ret = 0;
431
Boaz Harroshc1c201202009-02-03 07:47:29 +0100432 dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100433 /*
434 * fill in all the output members
435 */
FUJITA Tomonori47897162010-09-17 00:46:42 +0900436 hdr->device_status = rq->errors & 0xff;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100437 hdr->transport_status = host_byte(rq->errors);
438 hdr->driver_status = driver_byte(rq->errors);
439 hdr->info = 0;
440 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
441 hdr->info |= SG_INFO_CHECK;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100442 hdr->response_len = 0;
443
444 if (rq->sense_len && hdr->response) {
Jens Axboe25fd1642007-07-17 08:52:29 +0200445 int len = min_t(unsigned int, hdr->max_response_len,
446 rq->sense_len);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100447
Namhyung Kim2b727c62011-06-20 13:27:45 +0200448 ret = copy_to_user((void __user *)(unsigned long)hdr->response,
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100449 rq->sense, len);
450 if (!ret)
451 hdr->response_len = len;
452 else
453 ret = -EFAULT;
454 }
455
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200456 if (rq->next_rq) {
Tejun Heoc3a4d782009-05-07 22:24:37 +0900457 hdr->dout_resid = rq->resid_len;
458 hdr->din_resid = rq->next_rq->resid_len;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200459 blk_rq_unmap_user(bidi_bio);
460 blk_put_request(rq->next_rq);
FUJITA Tomonori0c6a89b2007-07-29 23:00:46 +0900461 } else if (rq_data_dir(rq) == READ)
Tejun Heoc3a4d782009-05-07 22:24:37 +0900462 hdr->din_resid = rq->resid_len;
FUJITA Tomonori0c6a89b2007-07-29 23:00:46 +0900463 else
Tejun Heoc3a4d782009-05-07 22:24:37 +0900464 hdr->dout_resid = rq->resid_len;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200465
James Bottomley2d507a02007-12-29 10:59:53 -0600466 /*
467 * If the request generated a negative error number, return it
468 * (providing we aren't already returning an error); if it's
469 * just a protocol response (i.e. non negative), that gets
470 * processed above.
471 */
472 if (!ret && rq->errors < 0)
473 ret = rq->errors;
474
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100475 blk_rq_unmap_user(bio);
FUJITA Tomonori9f5de6b2008-04-30 13:16:21 +0900476 if (rq->cmd != rq->__cmd)
477 kfree(rq->cmd);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100478 blk_put_request(rq);
479
480 return ret;
481}
482
Jens Axboe3d6392c2007-07-09 12:38:05 +0200483static int bsg_complete_all_commands(struct bsg_device *bd)
484{
485 struct bsg_command *bc;
486 int ret, tret;
487
488 dprintk("%s: entered\n", bd->name);
489
Jens Axboe3d6392c2007-07-09 12:38:05 +0200490 /*
491 * wait for all commands to complete
492 */
493 ret = 0;
494 do {
Jens Axboe25fd1642007-07-17 08:52:29 +0200495 ret = bsg_io_schedule(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200496 /*
497 * look for -ENODATA specifically -- we'll sometimes get
498 * -ERESTARTSYS when we've taken a signal, but we can't
499 * return until we're done freeing the queue, so ignore
500 * it. The signal will get handled when we're done freeing
501 * the bsg_device.
502 */
503 } while (ret != -ENODATA);
504
505 /*
506 * discard done commands
507 */
508 ret = 0;
509 do {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200510 spin_lock_irq(&bd->lock);
511 if (!bd->queued_cmds) {
512 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200513 break;
514 }
FUJITA Tomonoriefba1a32007-06-07 13:24:06 +0200515 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200516
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200517 bc = bsg_get_done_cmd(bd);
518 if (IS_ERR(bc))
519 break;
520
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200521 tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
522 bc->bidi_bio);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200523 if (!ret)
524 ret = tret;
525
526 bsg_free_command(bc);
527 } while (1);
528
529 return ret;
530}
531
Jens Axboe25fd1642007-07-17 08:52:29 +0200532static int
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200533__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
534 const struct iovec *iov, ssize_t *bytes_read)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200535{
536 struct bsg_command *bc;
537 int nr_commands, ret;
538
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100539 if (count % sizeof(struct sg_io_v4))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200540 return -EINVAL;
541
542 ret = 0;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100543 nr_commands = count / sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200544 while (nr_commands) {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200545 bc = bsg_get_done_cmd(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200546 if (IS_ERR(bc)) {
547 ret = PTR_ERR(bc);
548 break;
549 }
550
551 /*
552 * this is the only case where we need to copy data back
553 * after completing the request. so do that here,
554 * bsg_complete_work() cannot do that for us
555 */
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200556 ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
557 bc->bidi_bio);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200558
Jens Axboe25fd1642007-07-17 08:52:29 +0200559 if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200560 ret = -EFAULT;
561
562 bsg_free_command(bc);
563
564 if (ret)
565 break;
566
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100567 buf += sizeof(struct sg_io_v4);
568 *bytes_read += sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200569 nr_commands--;
570 }
571
572 return ret;
573}
574
575static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
576{
577 if (file->f_flags & O_NONBLOCK)
578 clear_bit(BSG_F_BLOCK, &bd->flags);
579 else
580 set_bit(BSG_F_BLOCK, &bd->flags);
581}
582
Jens Axboe25fd1642007-07-17 08:52:29 +0200583/*
584 * Check if the error is a "real" error that we should return.
585 */
Jens Axboe3d6392c2007-07-09 12:38:05 +0200586static inline int err_block_err(int ret)
587{
588 if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
589 return 1;
590
591 return 0;
592}
593
594static ssize_t
595bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
596{
597 struct bsg_device *bd = file->private_data;
598 int ret;
599 ssize_t bytes_read;
600
FUJITA Tomonori9e69fbb2006-12-20 11:18:22 +0100601 dprintk("%s: read %Zd bytes\n", bd->name, count);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200602
603 bsg_set_block(bd, file);
Adel Gadllah0b07de82008-06-26 13:48:27 +0200604
Jens Axboe3d6392c2007-07-09 12:38:05 +0200605 bytes_read = 0;
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200606 ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200607 *ppos = bytes_read;
608
Namhyung Kim44194e32011-06-20 13:27:44 +0200609 if (!bytes_read || err_block_err(ret))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200610 bytes_read = ret;
611
612 return bytes_read;
613}
614
Jens Axboe25fd1642007-07-17 08:52:29 +0200615static int __bsg_write(struct bsg_device *bd, const char __user *buf,
Al Viroaeb5d722008-09-02 15:28:45 -0400616 size_t count, ssize_t *bytes_written,
617 fmode_t has_write_perm)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200618{
619 struct bsg_command *bc;
620 struct request *rq;
621 int ret, nr_commands;
622
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100623 if (count % sizeof(struct sg_io_v4))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200624 return -EINVAL;
625
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100626 nr_commands = count / sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200627 rq = NULL;
628 bc = NULL;
629 ret = 0;
630 while (nr_commands) {
Jens Axboe165125e2007-07-24 09:28:11 +0200631 struct request_queue *q = bd->queue;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200632
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200633 bc = bsg_alloc_command(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200634 if (IS_ERR(bc)) {
635 ret = PTR_ERR(bc);
636 bc = NULL;
637 break;
638 }
639
Jens Axboe3d6392c2007-07-09 12:38:05 +0200640 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
641 ret = -EFAULT;
642 break;
643 }
644
645 /*
646 * get a request, fill in the blanks, and add to request queue
647 */
Boaz Harroshc1c201202009-02-03 07:47:29 +0100648 rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm, bc->sense);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200649 if (IS_ERR(rq)) {
650 ret = PTR_ERR(rq);
651 rq = NULL;
652 break;
653 }
654
655 bsg_add_command(bd, q, bc, rq);
656 bc = NULL;
657 rq = NULL;
658 nr_commands--;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100659 buf += sizeof(struct sg_io_v4);
Jens Axboe25fd1642007-07-17 08:52:29 +0200660 *bytes_written += sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200661 }
662
Jens Axboe3d6392c2007-07-09 12:38:05 +0200663 if (bc)
664 bsg_free_command(bc);
665
666 return ret;
667}
668
669static ssize_t
670bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
671{
672 struct bsg_device *bd = file->private_data;
Jens Axboe25fd1642007-07-17 08:52:29 +0200673 ssize_t bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200674 int ret;
675
FUJITA Tomonori9e69fbb2006-12-20 11:18:22 +0100676 dprintk("%s: write %Zd bytes\n", bd->name, count);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200677
678 bsg_set_block(bd, file);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200679
Jens Axboe25fd1642007-07-17 08:52:29 +0200680 bytes_written = 0;
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900681 ret = __bsg_write(bd, buf, count, &bytes_written,
682 file->f_mode & FMODE_WRITE);
683
Jens Axboe25fd1642007-07-17 08:52:29 +0200684 *ppos = bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200685
686 /*
687 * return bytes written on non-fatal errors
688 */
Namhyung Kim44194e32011-06-20 13:27:44 +0200689 if (!bytes_written || err_block_err(ret))
Jens Axboe25fd1642007-07-17 08:52:29 +0200690 bytes_written = ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200691
Jens Axboe25fd1642007-07-17 08:52:29 +0200692 dprintk("%s: returning %Zd\n", bd->name, bytes_written);
693 return bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200694}
695
Jens Axboe3d6392c2007-07-09 12:38:05 +0200696static struct bsg_device *bsg_alloc_device(void)
697{
Jens Axboe3d6392c2007-07-09 12:38:05 +0200698 struct bsg_device *bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200699
700 bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
701 if (unlikely(!bd))
702 return NULL;
703
704 spin_lock_init(&bd->lock);
705
Jens Axboe5309cb32007-01-23 16:24:41 +0100706 bd->max_queue = BSG_DEFAULT_CMDS;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200707
708 INIT_LIST_HEAD(&bd->busy_list);
709 INIT_LIST_HEAD(&bd->done_list);
710 INIT_HLIST_NODE(&bd->dev_list);
711
712 init_waitqueue_head(&bd->wq_free);
713 init_waitqueue_head(&bd->wq_done);
714 return bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200715}
716
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900717static void bsg_kref_release_function(struct kref *kref)
718{
719 struct bsg_class_device *bcd =
720 container_of(kref, struct bsg_class_device, ref);
James Bottomley8df5fc02008-07-07 15:50:01 -0500721 struct device *parent = bcd->parent;
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900722
723 if (bcd->release)
724 bcd->release(bcd->parent);
725
James Bottomley8df5fc02008-07-07 15:50:01 -0500726 put_device(parent);
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900727}
728
Jens Axboe3d6392c2007-07-09 12:38:05 +0200729static int bsg_put_device(struct bsg_device *bd)
730{
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900731 int ret = 0, do_free;
732 struct request_queue *q = bd->queue;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200733
734 mutex_lock(&bsg_mutex);
735
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900736 do_free = atomic_dec_and_test(&bd->ref_count);
FUJITA Tomonori3f27e3e2008-05-29 07:56:55 +0900737 if (!do_free) {
738 mutex_unlock(&bsg_mutex);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200739 goto out;
FUJITA Tomonori3f27e3e2008-05-29 07:56:55 +0900740 }
741
742 hlist_del(&bd->dev_list);
743 mutex_unlock(&bsg_mutex);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200744
745 dprintk("%s: tearing down\n", bd->name);
746
747 /*
748 * close can always block
749 */
750 set_bit(BSG_F_BLOCK, &bd->flags);
751
752 /*
753 * correct error detection baddies here again. it's the responsibility
754 * of the app to properly reap commands before close() if it wants
755 * fool-proof error detection
756 */
757 ret = bsg_complete_all_commands(bd);
758
Jens Axboe5309cb32007-01-23 16:24:41 +0100759 kfree(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200760out:
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900761 kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
762 if (do_free)
763 blk_put_queue(q);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200764 return ret;
765}
766
767static struct bsg_device *bsg_add_device(struct inode *inode,
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200768 struct request_queue *rq,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200769 struct file *file)
770{
Jens Axboe25fd1642007-07-17 08:52:29 +0200771 struct bsg_device *bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200772#ifdef BSG_DEBUG
773 unsigned char buf[32];
774#endif
Tejun Heo09ac46c2011-12-14 00:33:38 +0100775 if (!blk_get_queue(rq))
FUJITA Tomonoric3ff1b92008-03-31 10:03:39 +0900776 return ERR_PTR(-ENXIO);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200777
778 bd = bsg_alloc_device();
FUJITA Tomonoric3ff1b92008-03-31 10:03:39 +0900779 if (!bd) {
780 blk_put_queue(rq);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200781 return ERR_PTR(-ENOMEM);
FUJITA Tomonoric3ff1b92008-03-31 10:03:39 +0900782 }
Jens Axboe3d6392c2007-07-09 12:38:05 +0200783
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200784 bd->queue = rq;
Adel Gadllah0b07de82008-06-26 13:48:27 +0200785
Jens Axboe3d6392c2007-07-09 12:38:05 +0200786 bsg_set_block(bd, file);
787
788 atomic_set(&bd->ref_count, 1);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200789 mutex_lock(&bsg_mutex);
FUJITA Tomonori842ea772008-03-31 10:03:41 +0900790 hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
Jens Axboe3d6392c2007-07-09 12:38:05 +0200791
Kay Sievers3ada8b72009-01-06 10:44:43 -0800792 strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200793 dprintk("bound to <%s>, max queue %d\n",
FUJITA Tomonori9e69fbb2006-12-20 11:18:22 +0100794 format_dev_t(buf, inode->i_rdev), bd->max_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200795
796 mutex_unlock(&bsg_mutex);
797 return bd;
798}
799
FUJITA Tomonori842ea772008-03-31 10:03:41 +0900800static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200801{
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900802 struct bsg_device *bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200803 struct hlist_node *entry;
804
805 mutex_lock(&bsg_mutex);
806
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900807 hlist_for_each_entry(bd, entry, bsg_dev_idx_hash(minor), dev_list) {
FUJITA Tomonori842ea772008-03-31 10:03:41 +0900808 if (bd->queue == q) {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200809 atomic_inc(&bd->ref_count);
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900810 goto found;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200811 }
Jens Axboe3d6392c2007-07-09 12:38:05 +0200812 }
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900813 bd = NULL;
814found:
Jens Axboe3d6392c2007-07-09 12:38:05 +0200815 mutex_unlock(&bsg_mutex);
816 return bd;
817}
818
819static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
820{
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900821 struct bsg_device *bd;
822 struct bsg_class_device *bcd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200823
Jens Axboe3d6392c2007-07-09 12:38:05 +0200824 /*
825 * find the class device
826 */
Jens Axboe3d6392c2007-07-09 12:38:05 +0200827 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900828 bcd = idr_find(&bsg_minor_idr, iminor(inode));
FUJITA Tomonorid45ac4f2008-03-31 10:03:38 +0900829 if (bcd)
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900830 kref_get(&bcd->ref);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200831 mutex_unlock(&bsg_mutex);
832
833 if (!bcd)
834 return ERR_PTR(-ENODEV);
835
FUJITA Tomonori842ea772008-03-31 10:03:41 +0900836 bd = __bsg_get_device(iminor(inode), bcd->queue);
FUJITA Tomonorid45ac4f2008-03-31 10:03:38 +0900837 if (bd)
838 return bd;
839
840 bd = bsg_add_device(inode, bcd->queue, file);
841 if (IS_ERR(bd))
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900842 kref_put(&bcd->ref, bsg_kref_release_function);
FUJITA Tomonorid45ac4f2008-03-31 10:03:38 +0900843
844 return bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200845}
846
847static int bsg_open(struct inode *inode, struct file *file)
848{
Jonathan Corbet75bd2ef2008-05-15 09:09:23 -0600849 struct bsg_device *bd;
850
Jonathan Corbet75bd2ef2008-05-15 09:09:23 -0600851 bd = bsg_get_device(inode, file);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200852
853 if (IS_ERR(bd))
854 return PTR_ERR(bd);
855
856 file->private_data = bd;
857 return 0;
858}
859
860static int bsg_release(struct inode *inode, struct file *file)
861{
862 struct bsg_device *bd = file->private_data;
863
864 file->private_data = NULL;
865 return bsg_put_device(bd);
866}
867
868static unsigned int bsg_poll(struct file *file, poll_table *wait)
869{
870 struct bsg_device *bd = file->private_data;
871 unsigned int mask = 0;
872
873 poll_wait(file, &bd->wq_done, wait);
874 poll_wait(file, &bd->wq_free, wait);
875
876 spin_lock_irq(&bd->lock);
877 if (!list_empty(&bd->done_list))
878 mask |= POLLIN | POLLRDNORM;
Namhyung Kim80ceb052011-06-20 13:27:44 +0200879 if (bd->queued_cmds < bd->max_queue)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200880 mask |= POLLOUT;
881 spin_unlock_irq(&bd->lock);
882
883 return mask;
884}
885
Jens Axboe25fd1642007-07-17 08:52:29 +0200886static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200887{
888 struct bsg_device *bd = file->private_data;
889 int __user *uarg = (int __user *) arg;
James Bottomley2d507a02007-12-29 10:59:53 -0600890 int ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200891
Jens Axboe3d6392c2007-07-09 12:38:05 +0200892 switch (cmd) {
893 /*
894 * our own ioctls
895 */
896 case SG_GET_COMMAND_Q:
897 return put_user(bd->max_queue, uarg);
Jens Axboe5309cb32007-01-23 16:24:41 +0100898 case SG_SET_COMMAND_Q: {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200899 int queue;
900
901 if (get_user(queue, uarg))
902 return -EFAULT;
Jens Axboe5309cb32007-01-23 16:24:41 +0100903 if (queue < 1)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200904 return -EINVAL;
905
Jens Axboe5309cb32007-01-23 16:24:41 +0100906 spin_lock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200907 bd->max_queue = queue;
Jens Axboe5309cb32007-01-23 16:24:41 +0100908 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200909 return 0;
910 }
911
912 /*
913 * SCSI/sg ioctls
914 */
915 case SG_GET_VERSION_NUM:
916 case SCSI_IOCTL_GET_IDLUN:
917 case SCSI_IOCTL_GET_BUS_NUMBER:
918 case SG_SET_TIMEOUT:
919 case SG_GET_TIMEOUT:
920 case SG_GET_RESERVED_SIZE:
921 case SG_SET_RESERVED_SIZE:
922 case SG_EMULATED_HOST:
Jens Axboe3d6392c2007-07-09 12:38:05 +0200923 case SCSI_IOCTL_SEND_COMMAND: {
924 void __user *uarg = (void __user *) arg;
Al Viro74f3c8a2007-08-27 15:38:10 -0400925 return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200926 }
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100927 case SG_IO: {
928 struct request *rq;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200929 struct bio *bio, *bidi_bio = NULL;
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100930 struct sg_io_v4 hdr;
Boaz Harrosh05378942009-03-24 12:23:40 +0100931 int at_head;
Boaz Harroshc1c201202009-02-03 07:47:29 +0100932 u8 sense[SCSI_SENSE_BUFFERSIZE];
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100933
934 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
935 return -EFAULT;
936
Boaz Harroshc1c201202009-02-03 07:47:29 +0100937 rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE, sense);
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100938 if (IS_ERR(rq))
939 return PTR_ERR(rq);
940
941 bio = rq->bio;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200942 if (rq->next_rq)
943 bidi_bio = rq->next_rq->bio;
Boaz Harrosh05378942009-03-24 12:23:40 +0100944
945 at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
946 blk_execute_rq(bd->queue, NULL, rq, at_head);
James Bottomley2d507a02007-12-29 10:59:53 -0600947 ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100948
949 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
950 return -EFAULT;
Jens Axboeb711afa2006-12-20 11:25:23 +0100951
James Bottomley2d507a02007-12-29 10:59:53 -0600952 return ret;
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100953 }
Jens Axboe3d6392c2007-07-09 12:38:05 +0200954 /*
955 * block device ioctls
956 */
957 default:
958#if 0
959 return ioctl_by_bdev(bd->bdev, cmd, arg);
960#else
961 return -ENOTTY;
962#endif
963 }
964}
965
Arjan van de Ven7344be02007-10-15 11:01:53 +0200966static const struct file_operations bsg_fops = {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200967 .read = bsg_read,
968 .write = bsg_write,
969 .poll = bsg_poll,
970 .open = bsg_open,
971 .release = bsg_release,
Jens Axboe25fd1642007-07-17 08:52:29 +0200972 .unlocked_ioctl = bsg_ioctl,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200973 .owner = THIS_MODULE,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200974 .llseek = default_llseek,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200975};
976
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200977void bsg_unregister_queue(struct request_queue *q)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200978{
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200979 struct bsg_class_device *bcd = &q->bsg_dev;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200980
FUJITA Tomonoridf468822007-07-21 13:23:25 +0900981 if (!bcd->class_dev)
982 return;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200983
984 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900985 idr_remove(&bsg_minor_idr, bcd->minor);
Stanislaw Gruszka37b40ad2012-02-08 20:02:03 +0100986 if (q->kobj.sd)
987 sysfs_remove_link(&q->kobj, "bsg");
Tony Jonesee959b02008-02-22 00:13:36 +0100988 device_unregister(bcd->class_dev);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200989 bcd->class_dev = NULL;
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900990 kref_put(&bcd->ref, bsg_kref_release_function);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200991 mutex_unlock(&bsg_mutex);
992}
FUJITA Tomonori4cf07232007-03-30 11:19:39 +0200993EXPORT_SYMBOL_GPL(bsg_unregister_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200994
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900995int bsg_register_queue(struct request_queue *q, struct device *parent,
996 const char *name, void (*release)(struct device *))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200997{
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900998 struct bsg_class_device *bcd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200999 dev_t dev;
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001000 int ret, minor;
Tony Jonesee959b02008-02-22 00:13:36 +01001001 struct device *class_dev = NULL;
James Bottomley39dca552007-07-20 18:22:17 -05001002 const char *devname;
1003
1004 if (name)
1005 devname = name;
1006 else
Kay Sievers3ada8b72009-01-06 10:44:43 -08001007 devname = dev_name(parent);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001008
1009 /*
1010 * we need a proper transport to send commands, not a stacked device
1011 */
1012 if (!q->request_fn)
1013 return 0;
1014
FUJITA Tomonorid351af02007-07-09 12:40:35 +02001015 bcd = &q->bsg_dev;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001016 memset(bcd, 0, sizeof(*bcd));
Jens Axboe3d6392c2007-07-09 12:38:05 +02001017
1018 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001019
1020 ret = idr_pre_get(&bsg_minor_idr, GFP_KERNEL);
1021 if (!ret) {
1022 ret = -ENOMEM;
1023 goto unlock;
1024 }
1025
1026 ret = idr_get_new(&bsg_minor_idr, bcd, &minor);
1027 if (ret < 0)
1028 goto unlock;
1029
1030 if (minor >= BSG_MAX_DEVS) {
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001031 printk(KERN_ERR "bsg: too many bsg devices\n");
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001032 ret = -EINVAL;
1033 goto remove_idr;
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001034 }
1035
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001036 bcd->minor = minor;
FUJITA Tomonorid351af02007-07-09 12:40:35 +02001037 bcd->queue = q;
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +09001038 bcd->parent = get_device(parent);
1039 bcd->release = release;
1040 kref_init(&bcd->ref);
Jens Axboe46f6ef42007-07-17 08:56:10 +02001041 dev = MKDEV(bsg_major, bcd->minor);
Greg Kroah-Hartman1ff9f542008-07-21 20:03:34 -07001042 class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001043 if (IS_ERR(class_dev)) {
1044 ret = PTR_ERR(class_dev);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001045 goto put_dev;
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001046 }
1047 bcd->class_dev = class_dev;
1048
Linus Torvaldsabce8912007-07-16 11:18:23 -07001049 if (q->kobj.sd) {
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001050 ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
1051 if (ret)
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001052 goto unregister_class_dev;
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001053 }
1054
Jens Axboe3d6392c2007-07-09 12:38:05 +02001055 mutex_unlock(&bsg_mutex);
1056 return 0;
James Bottomley6826ee42007-07-20 16:50:10 -05001057
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001058unregister_class_dev:
Tony Jonesee959b02008-02-22 00:13:36 +01001059 device_unregister(class_dev);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001060put_dev:
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +09001061 put_device(parent);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001062remove_idr:
1063 idr_remove(&bsg_minor_idr, minor);
1064unlock:
Jens Axboe264a0472007-01-23 16:30:17 +01001065 mutex_unlock(&bsg_mutex);
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001066 return ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001067}
FUJITA Tomonori4cf07232007-03-30 11:19:39 +02001068EXPORT_SYMBOL_GPL(bsg_register_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001069
Greg Kroah-Hartman7e7654a2007-09-12 15:06:57 -07001070static struct cdev bsg_cdev;
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001071
Al Viro2c9ede52011-07-23 20:24:48 -04001072static char *bsg_devnode(struct device *dev, umode_t *mode)
Kay Sievers2bdf9142009-04-30 15:23:42 +02001073{
1074 return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
1075}
1076
Jens Axboe3d6392c2007-07-09 12:38:05 +02001077static int __init bsg_init(void)
1078{
1079 int ret, i;
Jens Axboe46f6ef42007-07-17 08:56:10 +02001080 dev_t devid;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001081
Jens Axboe5309cb32007-01-23 16:24:41 +01001082 bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
Paul Mundt20c2df82007-07-20 10:11:58 +09001083 sizeof(struct bsg_command), 0, 0, NULL);
Jens Axboe5309cb32007-01-23 16:24:41 +01001084 if (!bsg_cmd_cachep) {
1085 printk(KERN_ERR "bsg: failed creating slab cache\n");
1086 return -ENOMEM;
1087 }
1088
Jens Axboe25fd1642007-07-17 08:52:29 +02001089 for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
Jens Axboe3d6392c2007-07-09 12:38:05 +02001090 INIT_HLIST_HEAD(&bsg_device_list[i]);
1091
1092 bsg_class = class_create(THIS_MODULE, "bsg");
Jens Axboe5309cb32007-01-23 16:24:41 +01001093 if (IS_ERR(bsg_class)) {
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001094 ret = PTR_ERR(bsg_class);
1095 goto destroy_kmemcache;
Jens Axboe5309cb32007-01-23 16:24:41 +01001096 }
Kay Sieverse454cea2009-09-18 23:01:12 +02001097 bsg_class->devnode = bsg_devnode;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001098
Jens Axboe46f6ef42007-07-17 08:56:10 +02001099 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001100 if (ret)
1101 goto destroy_bsg_class;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001102
Jens Axboe46f6ef42007-07-17 08:56:10 +02001103 bsg_major = MAJOR(devid);
1104
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001105 cdev_init(&bsg_cdev, &bsg_fops);
Jens Axboe46f6ef42007-07-17 08:56:10 +02001106 ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001107 if (ret)
1108 goto unregister_chrdev;
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001109
Jens Axboe5d3a8cd2007-07-17 15:10:09 +02001110 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
FUJITA Tomonori0ed081c2007-07-17 12:21:35 +02001111 " loaded (major %d)\n", bsg_major);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001112 return 0;
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001113unregister_chrdev:
1114 unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1115destroy_bsg_class:
1116 class_destroy(bsg_class);
1117destroy_kmemcache:
1118 kmem_cache_destroy(bsg_cmd_cachep);
1119 return ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001120}
1121
1122MODULE_AUTHOR("Jens Axboe");
FUJITA Tomonori0ed081c2007-07-17 12:21:35 +02001123MODULE_DESCRIPTION(BSG_DESCRIPTION);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001124MODULE_LICENSE("GPL");
1125
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001126device_initcall(bsg_init);