blob: ee1335c68de7fe2f09878553535b3c6e9f5b3223 [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};
89
90static void bsg_free_command(struct bsg_command *bc)
91{
92 struct bsg_device *bd = bc->bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +020093 unsigned long flags;
94
Jens Axboe5309cb32007-01-23 16:24:41 +010095 kmem_cache_free(bsg_cmd_cachep, bc);
Jens Axboe3d6392c2007-07-09 12:38:05 +020096
97 spin_lock_irqsave(&bd->lock, flags);
98 bd->queued_cmds--;
Jens Axboe3d6392c2007-07-09 12:38:05 +020099 spin_unlock_irqrestore(&bd->lock, flags);
100
101 wake_up(&bd->wq_free);
102}
103
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200104static struct bsg_command *bsg_alloc_command(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200105{
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200106 struct bsg_command *bc = ERR_PTR(-EINVAL);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200107
108 spin_lock_irq(&bd->lock);
109
110 if (bd->queued_cmds >= bd->max_queue)
111 goto out;
112
Jens Axboe3d6392c2007-07-09 12:38:05 +0200113 bd->queued_cmds++;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200114 spin_unlock_irq(&bd->lock);
115
Jens Axboe25fd1642007-07-17 08:52:29 +0200116 bc = kmem_cache_zalloc(bsg_cmd_cachep, GFP_KERNEL);
Jens Axboe5309cb32007-01-23 16:24:41 +0100117 if (unlikely(!bc)) {
118 spin_lock_irq(&bd->lock);
FUJITA Tomonori7e75d732007-01-24 09:05:54 +0100119 bd->queued_cmds--;
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200120 bc = ERR_PTR(-ENOMEM);
FUJITA Tomonori7e75d732007-01-24 09:05:54 +0100121 goto out;
Jens Axboe5309cb32007-01-23 16:24:41 +0100122 }
123
Jens Axboe3d6392c2007-07-09 12:38:05 +0200124 bc->bd = bd;
125 INIT_LIST_HEAD(&bc->list);
Jens Axboe5309cb32007-01-23 16:24:41 +0100126 dprintk("%s: returning free cmd %p\n", bd->name, bc);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200127 return bc;
128out:
Jens Axboe3d6392c2007-07-09 12:38:05 +0200129 spin_unlock_irq(&bd->lock);
130 return bc;
131}
132
FUJITA Tomonori1c1133e2007-07-17 12:21:15 +0200133static inline struct hlist_head *bsg_dev_idx_hash(int index)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200134{
FUJITA Tomonori1c1133e2007-07-17 12:21:15 +0200135 return &bsg_device_list[index & (BSG_LIST_ARRAY_SIZE - 1)];
Jens Axboe3d6392c2007-07-09 12:38:05 +0200136}
137
Jens Axboe165125e2007-07-24 09:28:11 +0200138static int blk_fill_sgv4_hdr_rq(struct request_queue *q, struct request *rq,
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900139 struct sg_io_v4 *hdr, struct bsg_device *bd,
Al Viroaeb5d722008-09-02 15:28:45 -0400140 fmode_t has_write_perm)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200141{
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100142 struct scsi_request *req = scsi_req(rq);
143
FUJITA Tomonori9f5de6b2008-04-30 13:16:21 +0900144 if (hdr->request_len > BLK_MAX_CDB) {
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100145 req->cmd = kzalloc(hdr->request_len, GFP_KERNEL);
146 if (!req->cmd)
FUJITA Tomonori9f5de6b2008-04-30 13:16:21 +0900147 return -ENOMEM;
148 }
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100149
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100150 if (copy_from_user(req->cmd, (void __user *)(unsigned long)hdr->request,
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100151 hdr->request_len))
152 return -EFAULT;
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200153
154 if (hdr->subprotocol == BSG_SUB_PROTOCOL_SCSI_CMD) {
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100155 if (blk_verify_command(req->cmd, has_write_perm))
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200156 return -EPERM;
157 } else if (!capable(CAP_SYS_RAWIO))
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100158 return -EPERM;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200159
160 /*
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100161 * fill in request structure
Jens Axboe3d6392c2007-07-09 12:38:05 +0200162 */
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100163 req->cmd_len = hdr->request_len;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200164
Randy Dunlapad5ebd22009-11-11 13:47:45 +0100165 rq->timeout = msecs_to_jiffies(hdr->timeout);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100166 if (!rq->timeout)
167 rq->timeout = q->sg_timeout;
168 if (!rq->timeout)
169 rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
Linus Torvaldsf2f1fa72008-12-05 14:49:18 -0800170 if (rq->timeout < BLK_MIN_SG_TIMEOUT)
171 rq->timeout = BLK_MIN_SG_TIMEOUT;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200172
173 return 0;
174}
175
176/*
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100177 * Check if sg_io_v4 from user is allowed and valid
178 */
179static int
Christoph Hellwigaebf5262017-01-31 16:57:31 +0100180bsg_validate_sgv4_hdr(struct sg_io_v4 *hdr, int *op)
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100181{
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200182 int ret = 0;
183
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100184 if (hdr->guard != 'Q')
185 return -EINVAL;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100186
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200187 switch (hdr->protocol) {
188 case BSG_PROTOCOL_SCSI:
189 switch (hdr->subprotocol) {
190 case BSG_SUB_PROTOCOL_SCSI_CMD:
191 case BSG_SUB_PROTOCOL_SCSI_TRANSPORT:
192 break;
193 default:
194 ret = -EINVAL;
195 }
196 break;
197 default:
198 ret = -EINVAL;
199 }
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100200
Christoph Hellwigaebf5262017-01-31 16:57:31 +0100201 *op = hdr->dout_xfer_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN;
FUJITA Tomonori15d10b62007-07-16 08:52:16 +0200202 return ret;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100203}
204
205/*
206 * map sg_io_v4 to a request.
Jens Axboe3d6392c2007-07-09 12:38:05 +0200207 */
208static struct request *
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100209bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, fmode_t has_write_perm)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200210{
Jens Axboe165125e2007-07-24 09:28:11 +0200211 struct request_queue *q = bd->queue;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200212 struct request *rq, *next_rq = NULL;
Christoph Hellwigaebf5262017-01-31 16:57:31 +0100213 int ret;
214 unsigned int op, dxfer_len;
Namhyung Kim2b727c62011-06-20 13:27:45 +0200215 void __user *dxferp = NULL;
James Smartc7a841f2010-11-14 11:12:04 -0500216 struct bsg_class_device *bcd = &q->bsg_dev;
217
218 /* if the LLD has been removed then the bsg_unregister_queue will
219 * eventually be called and the class_dev was freed, so we can no
220 * longer use this request_queue. Return no such address.
221 */
222 if (!bcd->class_dev)
223 return ERR_PTR(-ENXIO);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200224
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100225 dprintk("map hdr %llx/%u %llx/%u\n", (unsigned long long) hdr->dout_xferp,
226 hdr->dout_xfer_len, (unsigned long long) hdr->din_xferp,
227 hdr->din_xfer_len);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200228
Christoph Hellwigaebf5262017-01-31 16:57:31 +0100229 ret = bsg_validate_sgv4_hdr(hdr, &op);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200230 if (ret)
231 return ERR_PTR(ret);
232
233 /*
Daniel Mack3ad2f3f2010-02-03 08:01:28 +0800234 * map scatter-gather elements separately and string them to request
Jens Axboe3d6392c2007-07-09 12:38:05 +0200235 */
Christoph Hellwigaebf5262017-01-31 16:57:31 +0100236 rq = blk_get_request(q, op, GFP_KERNEL);
Joe Lawrencea492f072014-08-28 08:15:21 -0600237 if (IS_ERR(rq))
238 return rq;
Jens Axboef27b0872014-06-06 07:57:37 -0600239
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900240 ret = blk_fill_sgv4_hdr_rq(q, rq, hdr, bd, has_write_perm);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200241 if (ret)
242 goto out;
243
Christoph Hellwigaebf5262017-01-31 16:57:31 +0100244 if (op == REQ_OP_SCSI_OUT && hdr->din_xfer_len) {
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200245 if (!test_bit(QUEUE_FLAG_BIDI, &q->queue_flags)) {
246 ret = -EOPNOTSUPP;
247 goto out;
248 }
249
Christoph Hellwigaebf5262017-01-31 16:57:31 +0100250 next_rq = blk_get_request(q, REQ_OP_SCSI_IN, GFP_KERNEL);
Joe Lawrencea492f072014-08-28 08:15:21 -0600251 if (IS_ERR(next_rq)) {
252 ret = PTR_ERR(next_rq);
Jens Axboe55872c52014-08-28 15:05:40 -0600253 next_rq = NULL;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200254 goto out;
255 }
256 rq->next_rq = next_rq;
257
Namhyung Kim2b727c62011-06-20 13:27:45 +0200258 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900259 ret = blk_rq_map_user(q, next_rq, NULL, dxferp,
260 hdr->din_xfer_len, GFP_KERNEL);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200261 if (ret)
262 goto out;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200263 }
264
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100265 if (hdr->dout_xfer_len) {
266 dxfer_len = hdr->dout_xfer_len;
Namhyung Kim2b727c62011-06-20 13:27:45 +0200267 dxferp = (void __user *)(unsigned long)hdr->dout_xferp;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100268 } else if (hdr->din_xfer_len) {
269 dxfer_len = hdr->din_xfer_len;
Namhyung Kim2b727c62011-06-20 13:27:45 +0200270 dxferp = (void __user *)(unsigned long)hdr->din_xferp;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100271 } else
272 dxfer_len = 0;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200273
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100274 if (dxfer_len) {
FUJITA Tomonori152e2832008-08-28 16:17:06 +0900275 ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
276 GFP_KERNEL);
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200277 if (ret)
278 goto out;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200279 }
Boaz Harroshc1c20122009-02-03 07:47:29 +0100280
Jens Axboe3d6392c2007-07-09 12:38:05 +0200281 return rq;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200282out:
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100283 scsi_req_free_cmd(scsi_req(rq));
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200284 blk_put_request(rq);
285 if (next_rq) {
286 blk_rq_unmap_user(next_rq->bio);
287 blk_put_request(next_rq);
288 }
289 return ERR_PTR(ret);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200290}
291
292/*
293 * async completion call-back from the block layer, when scsi/ide/whatever
294 * calls end_that_request_last() on a request
295 */
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200296static void bsg_rq_end_io(struct request *rq, blk_status_t status)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200297{
298 struct bsg_command *bc = rq->end_io_data;
299 struct bsg_device *bd = bc->bd;
300 unsigned long flags;
301
Christoph Hellwig2a842ac2017-06-03 09:38:04 +0200302 dprintk("%s: finished rq %p bc %p, bio %p\n",
303 bd->name, rq, bc, bc->bio);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200304
305 bc->hdr.duration = jiffies_to_msecs(jiffies - bc->hdr.duration);
306
307 spin_lock_irqsave(&bd->lock, flags);
Jens Axboe25fd1642007-07-17 08:52:29 +0200308 list_move_tail(&bc->list, &bd->done_list);
309 bd->done_cmds++;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200310 spin_unlock_irqrestore(&bd->lock, flags);
Jens Axboe25fd1642007-07-17 08:52:29 +0200311
312 wake_up(&bd->wq_done);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200313}
314
315/*
316 * do final setup of a 'bc' and submit the matching 'rq' to the block
317 * layer for io
318 */
Jens Axboe165125e2007-07-24 09:28:11 +0200319static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200320 struct bsg_command *bc, struct request *rq)
321{
Boaz Harrosh05378942009-03-24 12:23:40 +0100322 int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
323
Jens Axboe3d6392c2007-07-09 12:38:05 +0200324 /*
325 * add bc command to busy queue and submit rq for io
326 */
327 bc->rq = rq;
328 bc->bio = rq->bio;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200329 if (rq->next_rq)
330 bc->bidi_bio = rq->next_rq->bio;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200331 bc->hdr.duration = jiffies;
332 spin_lock_irq(&bd->lock);
333 list_add_tail(&bc->list, &bd->busy_list);
334 spin_unlock_irq(&bd->lock);
335
336 dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
337
338 rq->end_io_data = bc;
Boaz Harrosh05378942009-03-24 12:23:40 +0100339 blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200340}
341
Jens Axboe25fd1642007-07-17 08:52:29 +0200342static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200343{
344 struct bsg_command *bc = NULL;
345
346 spin_lock_irq(&bd->lock);
347 if (bd->done_cmds) {
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900348 bc = list_first_entry(&bd->done_list, struct bsg_command, list);
Jens Axboe25fd1642007-07-17 08:52:29 +0200349 list_del(&bc->list);
350 bd->done_cmds--;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200351 }
352 spin_unlock_irq(&bd->lock);
353
354 return bc;
355}
356
357/*
358 * Get a finished command from the done list
359 */
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200360static struct bsg_command *bsg_get_done_cmd(struct bsg_device *bd)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200361{
362 struct bsg_command *bc;
363 int ret;
364
365 do {
366 bc = bsg_next_done_cmd(bd);
367 if (bc)
368 break;
369
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200370 if (!test_bit(BSG_F_BLOCK, &bd->flags)) {
371 bc = ERR_PTR(-EAGAIN);
372 break;
373 }
374
375 ret = wait_event_interruptible(bd->wq_done, bd->done_cmds);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200376 if (ret) {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200377 bc = ERR_PTR(-ERESTARTSYS);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200378 break;
379 }
380 } while (1);
381
382 dprintk("%s: returning done %p\n", bd->name, bc);
383
384 return bc;
385}
386
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100387static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200388 struct bio *bio, struct bio *bidi_bio)
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100389{
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100390 struct scsi_request *req = scsi_req(rq);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100391 int ret = 0;
392
Christoph Hellwig17d53632017-04-20 16:03:01 +0200393 dprintk("rq %p bio %p 0x%x\n", rq, bio, req->result);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100394 /*
395 * fill in all the output members
396 */
Christoph Hellwig17d53632017-04-20 16:03:01 +0200397 hdr->device_status = req->result & 0xff;
398 hdr->transport_status = host_byte(req->result);
399 hdr->driver_status = driver_byte(req->result);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100400 hdr->info = 0;
401 if (hdr->device_status || hdr->transport_status || hdr->driver_status)
402 hdr->info |= SG_INFO_CHECK;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100403 hdr->response_len = 0;
404
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100405 if (req->sense_len && hdr->response) {
Jens Axboe25fd1642007-07-17 08:52:29 +0200406 int len = min_t(unsigned int, hdr->max_response_len,
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100407 req->sense_len);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100408
Namhyung Kim2b727c62011-06-20 13:27:45 +0200409 ret = copy_to_user((void __user *)(unsigned long)hdr->response,
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100410 req->sense, len);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100411 if (!ret)
412 hdr->response_len = len;
413 else
414 ret = -EFAULT;
415 }
416
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200417 if (rq->next_rq) {
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100418 hdr->dout_resid = req->resid_len;
419 hdr->din_resid = scsi_req(rq->next_rq)->resid_len;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200420 blk_rq_unmap_user(bidi_bio);
421 blk_put_request(rq->next_rq);
FUJITA Tomonori0c6a89b2007-07-29 23:00:46 +0900422 } else if (rq_data_dir(rq) == READ)
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100423 hdr->din_resid = req->resid_len;
FUJITA Tomonori0c6a89b2007-07-29 23:00:46 +0900424 else
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100425 hdr->dout_resid = req->resid_len;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200426
James Bottomley2d507a02007-12-29 10:59:53 -0600427 /*
428 * If the request generated a negative error number, return it
429 * (providing we aren't already returning an error); if it's
430 * just a protocol response (i.e. non negative), that gets
431 * processed above.
432 */
Christoph Hellwig17d53632017-04-20 16:03:01 +0200433 if (!ret && req->result < 0)
434 ret = req->result;
James Bottomley2d507a02007-12-29 10:59:53 -0600435
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100436 blk_rq_unmap_user(bio);
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100437 scsi_req_free_cmd(req);
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100438 blk_put_request(rq);
439
440 return ret;
441}
442
Peter Zijlstra2c561242015-02-03 12:55:31 +0100443static bool bsg_complete(struct bsg_device *bd)
444{
445 bool ret = false;
446 bool spin;
447
448 do {
449 spin_lock_irq(&bd->lock);
450
451 BUG_ON(bd->done_cmds > bd->queued_cmds);
452
453 /*
454 * All commands consumed.
455 */
456 if (bd->done_cmds == bd->queued_cmds)
457 ret = true;
458
459 spin = !test_bit(BSG_F_BLOCK, &bd->flags);
460
461 spin_unlock_irq(&bd->lock);
462 } while (!ret && spin);
463
464 return ret;
465}
466
Jens Axboe3d6392c2007-07-09 12:38:05 +0200467static int bsg_complete_all_commands(struct bsg_device *bd)
468{
469 struct bsg_command *bc;
470 int ret, tret;
471
472 dprintk("%s: entered\n", bd->name);
473
Jens Axboe3d6392c2007-07-09 12:38:05 +0200474 /*
475 * wait for all commands to complete
476 */
Peter Zijlstra2c561242015-02-03 12:55:31 +0100477 io_wait_event(bd->wq_done, bsg_complete(bd));
Jens Axboe3d6392c2007-07-09 12:38:05 +0200478
479 /*
480 * discard done commands
481 */
482 ret = 0;
483 do {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200484 spin_lock_irq(&bd->lock);
485 if (!bd->queued_cmds) {
486 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200487 break;
488 }
FUJITA Tomonoriefba1a32007-06-07 13:24:06 +0200489 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200490
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200491 bc = bsg_get_done_cmd(bd);
492 if (IS_ERR(bc))
493 break;
494
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200495 tret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
496 bc->bidi_bio);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200497 if (!ret)
498 ret = tret;
499
500 bsg_free_command(bc);
501 } while (1);
502
503 return ret;
504}
505
Jens Axboe25fd1642007-07-17 08:52:29 +0200506static int
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200507__bsg_read(char __user *buf, size_t count, struct bsg_device *bd,
508 const struct iovec *iov, ssize_t *bytes_read)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200509{
510 struct bsg_command *bc;
511 int nr_commands, ret;
512
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100513 if (count % sizeof(struct sg_io_v4))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200514 return -EINVAL;
515
516 ret = 0;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100517 nr_commands = count / sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200518 while (nr_commands) {
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200519 bc = bsg_get_done_cmd(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200520 if (IS_ERR(bc)) {
521 ret = PTR_ERR(bc);
522 break;
523 }
524
525 /*
526 * this is the only case where we need to copy data back
527 * after completing the request. so do that here,
528 * bsg_complete_work() cannot do that for us
529 */
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200530 ret = blk_complete_sgv4_hdr_rq(bc->rq, &bc->hdr, bc->bio,
531 bc->bidi_bio);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200532
Jens Axboe25fd1642007-07-17 08:52:29 +0200533 if (copy_to_user(buf, &bc->hdr, sizeof(bc->hdr)))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200534 ret = -EFAULT;
535
536 bsg_free_command(bc);
537
538 if (ret)
539 break;
540
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100541 buf += sizeof(struct sg_io_v4);
542 *bytes_read += sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200543 nr_commands--;
544 }
545
546 return ret;
547}
548
549static inline void bsg_set_block(struct bsg_device *bd, struct file *file)
550{
551 if (file->f_flags & O_NONBLOCK)
552 clear_bit(BSG_F_BLOCK, &bd->flags);
553 else
554 set_bit(BSG_F_BLOCK, &bd->flags);
555}
556
Jens Axboe25fd1642007-07-17 08:52:29 +0200557/*
558 * Check if the error is a "real" error that we should return.
559 */
Jens Axboe3d6392c2007-07-09 12:38:05 +0200560static inline int err_block_err(int ret)
561{
562 if (ret && ret != -ENOSPC && ret != -ENODATA && ret != -EAGAIN)
563 return 1;
564
565 return 0;
566}
567
568static ssize_t
569bsg_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
570{
571 struct bsg_device *bd = file->private_data;
572 int ret;
573 ssize_t bytes_read;
574
Alexey Dobriyan5b5e0922017-02-27 14:30:02 -0800575 dprintk("%s: read %zd bytes\n", bd->name, count);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200576
577 bsg_set_block(bd, file);
Adel Gadllah0b07de82008-06-26 13:48:27 +0200578
Jens Axboe3d6392c2007-07-09 12:38:05 +0200579 bytes_read = 0;
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200580 ret = __bsg_read(buf, count, bd, NULL, &bytes_read);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200581 *ppos = bytes_read;
582
Namhyung Kim44194e32011-06-20 13:27:44 +0200583 if (!bytes_read || err_block_err(ret))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200584 bytes_read = ret;
585
586 return bytes_read;
587}
588
Jens Axboe25fd1642007-07-17 08:52:29 +0200589static int __bsg_write(struct bsg_device *bd, const char __user *buf,
Al Viroaeb5d722008-09-02 15:28:45 -0400590 size_t count, ssize_t *bytes_written,
591 fmode_t has_write_perm)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200592{
593 struct bsg_command *bc;
594 struct request *rq;
595 int ret, nr_commands;
596
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100597 if (count % sizeof(struct sg_io_v4))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200598 return -EINVAL;
599
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100600 nr_commands = count / sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200601 rq = NULL;
602 bc = NULL;
603 ret = 0;
604 while (nr_commands) {
Jens Axboe165125e2007-07-24 09:28:11 +0200605 struct request_queue *q = bd->queue;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200606
FUJITA Tomonorie7d72172007-05-08 15:32:03 +0200607 bc = bsg_alloc_command(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200608 if (IS_ERR(bc)) {
609 ret = PTR_ERR(bc);
610 bc = NULL;
611 break;
612 }
613
Jens Axboe3d6392c2007-07-09 12:38:05 +0200614 if (copy_from_user(&bc->hdr, buf, sizeof(bc->hdr))) {
615 ret = -EFAULT;
616 break;
617 }
618
619 /*
620 * get a request, fill in the blanks, and add to request queue
621 */
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100622 rq = bsg_map_hdr(bd, &bc->hdr, has_write_perm);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200623 if (IS_ERR(rq)) {
624 ret = PTR_ERR(rq);
625 rq = NULL;
626 break;
627 }
628
629 bsg_add_command(bd, q, bc, rq);
630 bc = NULL;
631 rq = NULL;
632 nr_commands--;
FUJITA Tomonori70e36ec2006-12-20 11:20:15 +0100633 buf += sizeof(struct sg_io_v4);
Jens Axboe25fd1642007-07-17 08:52:29 +0200634 *bytes_written += sizeof(struct sg_io_v4);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200635 }
636
Jens Axboe3d6392c2007-07-09 12:38:05 +0200637 if (bc)
638 bsg_free_command(bc);
639
640 return ret;
641}
642
643static ssize_t
644bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
645{
646 struct bsg_device *bd = file->private_data;
Jens Axboe25fd1642007-07-17 08:52:29 +0200647 ssize_t bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200648 int ret;
649
Alexey Dobriyan5b5e0922017-02-27 14:30:02 -0800650 dprintk("%s: write %zd bytes\n", bd->name, count);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200651
Al Virodb68ce12017-03-20 21:08:07 -0400652 if (unlikely(uaccess_kernel()))
Al Viro128394e2016-12-16 13:42:06 -0500653 return -EINVAL;
654
Jens Axboe3d6392c2007-07-09 12:38:05 +0200655 bsg_set_block(bd, file);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200656
Jens Axboe25fd1642007-07-17 08:52:29 +0200657 bytes_written = 0;
FUJITA Tomonoriabf54392008-08-16 14:10:05 +0900658 ret = __bsg_write(bd, buf, count, &bytes_written,
659 file->f_mode & FMODE_WRITE);
660
Jens Axboe25fd1642007-07-17 08:52:29 +0200661 *ppos = bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200662
663 /*
664 * return bytes written on non-fatal errors
665 */
Namhyung Kim44194e32011-06-20 13:27:44 +0200666 if (!bytes_written || err_block_err(ret))
Jens Axboe25fd1642007-07-17 08:52:29 +0200667 bytes_written = ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200668
Alexey Dobriyan5b5e0922017-02-27 14:30:02 -0800669 dprintk("%s: returning %zd\n", bd->name, bytes_written);
Jens Axboe25fd1642007-07-17 08:52:29 +0200670 return bytes_written;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200671}
672
Jens Axboe3d6392c2007-07-09 12:38:05 +0200673static struct bsg_device *bsg_alloc_device(void)
674{
Jens Axboe3d6392c2007-07-09 12:38:05 +0200675 struct bsg_device *bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200676
677 bd = kzalloc(sizeof(struct bsg_device), GFP_KERNEL);
678 if (unlikely(!bd))
679 return NULL;
680
681 spin_lock_init(&bd->lock);
682
Jens Axboe5309cb32007-01-23 16:24:41 +0100683 bd->max_queue = BSG_DEFAULT_CMDS;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200684
685 INIT_LIST_HEAD(&bd->busy_list);
686 INIT_LIST_HEAD(&bd->done_list);
687 INIT_HLIST_NODE(&bd->dev_list);
688
689 init_waitqueue_head(&bd->wq_free);
690 init_waitqueue_head(&bd->wq_done);
691 return bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200692}
693
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900694static void bsg_kref_release_function(struct kref *kref)
695{
696 struct bsg_class_device *bcd =
697 container_of(kref, struct bsg_class_device, ref);
James Bottomley8df5fc02008-07-07 15:50:01 -0500698 struct device *parent = bcd->parent;
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900699
700 if (bcd->release)
701 bcd->release(bcd->parent);
702
James Bottomley8df5fc02008-07-07 15:50:01 -0500703 put_device(parent);
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900704}
705
Jens Axboe3d6392c2007-07-09 12:38:05 +0200706static int bsg_put_device(struct bsg_device *bd)
707{
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900708 int ret = 0, do_free;
709 struct request_queue *q = bd->queue;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200710
711 mutex_lock(&bsg_mutex);
712
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900713 do_free = atomic_dec_and_test(&bd->ref_count);
FUJITA Tomonori3f27e3e2008-05-29 07:56:55 +0900714 if (!do_free) {
715 mutex_unlock(&bsg_mutex);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200716 goto out;
FUJITA Tomonori3f27e3e2008-05-29 07:56:55 +0900717 }
718
719 hlist_del(&bd->dev_list);
720 mutex_unlock(&bsg_mutex);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200721
722 dprintk("%s: tearing down\n", bd->name);
723
724 /*
725 * close can always block
726 */
727 set_bit(BSG_F_BLOCK, &bd->flags);
728
729 /*
730 * correct error detection baddies here again. it's the responsibility
731 * of the app to properly reap commands before close() if it wants
732 * fool-proof error detection
733 */
734 ret = bsg_complete_all_commands(bd);
735
Jens Axboe5309cb32007-01-23 16:24:41 +0100736 kfree(bd);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200737out:
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900738 kref_put(&q->bsg_dev.ref, bsg_kref_release_function);
739 if (do_free)
740 blk_put_queue(q);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200741 return ret;
742}
743
744static struct bsg_device *bsg_add_device(struct inode *inode,
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200745 struct request_queue *rq,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200746 struct file *file)
747{
Jens Axboe25fd1642007-07-17 08:52:29 +0200748 struct bsg_device *bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200749#ifdef BSG_DEBUG
750 unsigned char buf[32];
751#endif
Bart Van Assched9f97262017-05-31 14:43:47 -0700752
753 if (!blk_queue_scsi_passthrough(rq)) {
754 WARN_ONCE(true, "Attempt to register a non-SCSI queue\n");
755 return ERR_PTR(-EINVAL);
756 }
757
Tejun Heo09ac46c2011-12-14 00:33:38 +0100758 if (!blk_get_queue(rq))
FUJITA Tomonoric3ff1b92008-03-31 10:03:39 +0900759 return ERR_PTR(-ENXIO);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200760
761 bd = bsg_alloc_device();
FUJITA Tomonoric3ff1b92008-03-31 10:03:39 +0900762 if (!bd) {
763 blk_put_queue(rq);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200764 return ERR_PTR(-ENOMEM);
FUJITA Tomonoric3ff1b92008-03-31 10:03:39 +0900765 }
Jens Axboe3d6392c2007-07-09 12:38:05 +0200766
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200767 bd->queue = rq;
Adel Gadllah0b07de82008-06-26 13:48:27 +0200768
Jens Axboe3d6392c2007-07-09 12:38:05 +0200769 bsg_set_block(bd, file);
770
771 atomic_set(&bd->ref_count, 1);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200772 mutex_lock(&bsg_mutex);
FUJITA Tomonori842ea772008-03-31 10:03:41 +0900773 hlist_add_head(&bd->dev_list, bsg_dev_idx_hash(iminor(inode)));
Jens Axboe3d6392c2007-07-09 12:38:05 +0200774
Kay Sievers3ada8b72009-01-06 10:44:43 -0800775 strncpy(bd->name, dev_name(rq->bsg_dev.class_dev), sizeof(bd->name) - 1);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200776 dprintk("bound to <%s>, max queue %d\n",
FUJITA Tomonori9e69fbb2006-12-20 11:18:22 +0100777 format_dev_t(buf, inode->i_rdev), bd->max_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200778
779 mutex_unlock(&bsg_mutex);
780 return bd;
781}
782
FUJITA Tomonori842ea772008-03-31 10:03:41 +0900783static struct bsg_device *__bsg_get_device(int minor, struct request_queue *q)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200784{
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900785 struct bsg_device *bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200786
787 mutex_lock(&bsg_mutex);
788
Sasha Levinb67bfe02013-02-27 17:06:00 -0800789 hlist_for_each_entry(bd, bsg_dev_idx_hash(minor), dev_list) {
FUJITA Tomonori842ea772008-03-31 10:03:41 +0900790 if (bd->queue == q) {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200791 atomic_inc(&bd->ref_count);
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900792 goto found;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200793 }
Jens Axboe3d6392c2007-07-09 12:38:05 +0200794 }
FUJITA Tomonori43ac9e62008-03-31 10:03:40 +0900795 bd = NULL;
796found:
Jens Axboe3d6392c2007-07-09 12:38:05 +0200797 mutex_unlock(&bsg_mutex);
798 return bd;
799}
800
801static struct bsg_device *bsg_get_device(struct inode *inode, struct file *file)
802{
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900803 struct bsg_device *bd;
804 struct bsg_class_device *bcd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200805
Jens Axboe3d6392c2007-07-09 12:38:05 +0200806 /*
807 * find the class device
808 */
Jens Axboe3d6392c2007-07-09 12:38:05 +0200809 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900810 bcd = idr_find(&bsg_minor_idr, iminor(inode));
FUJITA Tomonorid45ac4f2008-03-31 10:03:38 +0900811 if (bcd)
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900812 kref_get(&bcd->ref);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200813 mutex_unlock(&bsg_mutex);
814
815 if (!bcd)
816 return ERR_PTR(-ENODEV);
817
FUJITA Tomonori842ea772008-03-31 10:03:41 +0900818 bd = __bsg_get_device(iminor(inode), bcd->queue);
FUJITA Tomonorid45ac4f2008-03-31 10:03:38 +0900819 if (bd)
820 return bd;
821
822 bd = bsg_add_device(inode, bcd->queue, file);
823 if (IS_ERR(bd))
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900824 kref_put(&bcd->ref, bsg_kref_release_function);
FUJITA Tomonorid45ac4f2008-03-31 10:03:38 +0900825
826 return bd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200827}
828
829static int bsg_open(struct inode *inode, struct file *file)
830{
Jonathan Corbet75bd2ef2008-05-15 09:09:23 -0600831 struct bsg_device *bd;
832
Jonathan Corbet75bd2ef2008-05-15 09:09:23 -0600833 bd = bsg_get_device(inode, file);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200834
835 if (IS_ERR(bd))
836 return PTR_ERR(bd);
837
838 file->private_data = bd;
839 return 0;
840}
841
842static int bsg_release(struct inode *inode, struct file *file)
843{
844 struct bsg_device *bd = file->private_data;
845
846 file->private_data = NULL;
847 return bsg_put_device(bd);
848}
849
850static unsigned int bsg_poll(struct file *file, poll_table *wait)
851{
852 struct bsg_device *bd = file->private_data;
853 unsigned int mask = 0;
854
855 poll_wait(file, &bd->wq_done, wait);
856 poll_wait(file, &bd->wq_free, wait);
857
858 spin_lock_irq(&bd->lock);
859 if (!list_empty(&bd->done_list))
860 mask |= POLLIN | POLLRDNORM;
Namhyung Kim80ceb052011-06-20 13:27:44 +0200861 if (bd->queued_cmds < bd->max_queue)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200862 mask |= POLLOUT;
863 spin_unlock_irq(&bd->lock);
864
865 return mask;
866}
867
Jens Axboe25fd1642007-07-17 08:52:29 +0200868static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200869{
870 struct bsg_device *bd = file->private_data;
871 int __user *uarg = (int __user *) arg;
James Bottomley2d507a02007-12-29 10:59:53 -0600872 int ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200873
Jens Axboe3d6392c2007-07-09 12:38:05 +0200874 switch (cmd) {
875 /*
876 * our own ioctls
877 */
878 case SG_GET_COMMAND_Q:
879 return put_user(bd->max_queue, uarg);
Jens Axboe5309cb32007-01-23 16:24:41 +0100880 case SG_SET_COMMAND_Q: {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200881 int queue;
882
883 if (get_user(queue, uarg))
884 return -EFAULT;
Jens Axboe5309cb32007-01-23 16:24:41 +0100885 if (queue < 1)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200886 return -EINVAL;
887
Jens Axboe5309cb32007-01-23 16:24:41 +0100888 spin_lock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200889 bd->max_queue = queue;
Jens Axboe5309cb32007-01-23 16:24:41 +0100890 spin_unlock_irq(&bd->lock);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200891 return 0;
892 }
893
894 /*
895 * SCSI/sg ioctls
896 */
897 case SG_GET_VERSION_NUM:
898 case SCSI_IOCTL_GET_IDLUN:
899 case SCSI_IOCTL_GET_BUS_NUMBER:
900 case SG_SET_TIMEOUT:
901 case SG_GET_TIMEOUT:
902 case SG_GET_RESERVED_SIZE:
903 case SG_SET_RESERVED_SIZE:
904 case SG_EMULATED_HOST:
Jens Axboe3d6392c2007-07-09 12:38:05 +0200905 case SCSI_IOCTL_SEND_COMMAND: {
906 void __user *uarg = (void __user *) arg;
Al Viro74f3c8a2007-08-27 15:38:10 -0400907 return scsi_cmd_ioctl(bd->queue, NULL, file->f_mode, cmd, uarg);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200908 }
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100909 case SG_IO: {
910 struct request *rq;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200911 struct bio *bio, *bidi_bio = NULL;
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100912 struct sg_io_v4 hdr;
Boaz Harrosh05378942009-03-24 12:23:40 +0100913 int at_head;
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100914
915 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
916 return -EFAULT;
917
Christoph Hellwig82ed4db2017-01-27 09:46:29 +0100918 rq = bsg_map_hdr(bd, &hdr, file->f_mode & FMODE_WRITE);
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100919 if (IS_ERR(rq))
920 return PTR_ERR(rq);
921
922 bio = rq->bio;
FUJITA Tomonori2c9ecdf2007-07-16 08:52:15 +0200923 if (rq->next_rq)
924 bidi_bio = rq->next_rq->bio;
Boaz Harrosh05378942009-03-24 12:23:40 +0100925
926 at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
927 blk_execute_rq(bd->queue, NULL, rq, at_head);
James Bottomley2d507a02007-12-29 10:59:53 -0600928 ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100929
930 if (copy_to_user(uarg, &hdr, sizeof(hdr)))
931 return -EFAULT;
Jens Axboeb711afa2006-12-20 11:25:23 +0100932
James Bottomley2d507a02007-12-29 10:59:53 -0600933 return ret;
FUJITA Tomonori10e88552006-12-20 11:20:57 +0100934 }
Jens Axboe3d6392c2007-07-09 12:38:05 +0200935 default:
Jens Axboe3d6392c2007-07-09 12:38:05 +0200936 return -ENOTTY;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200937 }
938}
939
Arjan van de Ven7344be02007-10-15 11:01:53 +0200940static const struct file_operations bsg_fops = {
Jens Axboe3d6392c2007-07-09 12:38:05 +0200941 .read = bsg_read,
942 .write = bsg_write,
943 .poll = bsg_poll,
944 .open = bsg_open,
945 .release = bsg_release,
Jens Axboe25fd1642007-07-17 08:52:29 +0200946 .unlocked_ioctl = bsg_ioctl,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200947 .owner = THIS_MODULE,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200948 .llseek = default_llseek,
Jens Axboe3d6392c2007-07-09 12:38:05 +0200949};
950
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200951void bsg_unregister_queue(struct request_queue *q)
Jens Axboe3d6392c2007-07-09 12:38:05 +0200952{
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200953 struct bsg_class_device *bcd = &q->bsg_dev;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200954
FUJITA Tomonoridf468822007-07-21 13:23:25 +0900955 if (!bcd->class_dev)
956 return;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200957
958 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900959 idr_remove(&bsg_minor_idr, bcd->minor);
Stanislaw Gruszka37b40ad2012-02-08 20:02:03 +0100960 if (q->kobj.sd)
961 sysfs_remove_link(&q->kobj, "bsg");
Tony Jonesee959b02008-02-22 00:13:36 +0100962 device_unregister(bcd->class_dev);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200963 bcd->class_dev = NULL;
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900964 kref_put(&bcd->ref, bsg_kref_release_function);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200965 mutex_unlock(&bsg_mutex);
966}
FUJITA Tomonori4cf07232007-03-30 11:19:39 +0200967EXPORT_SYMBOL_GPL(bsg_unregister_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200968
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +0900969int bsg_register_queue(struct request_queue *q, struct device *parent,
970 const char *name, void (*release)(struct device *))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200971{
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900972 struct bsg_class_device *bcd;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200973 dev_t dev;
Tejun Heobab998d2013-02-27 17:03:57 -0800974 int ret;
Tony Jonesee959b02008-02-22 00:13:36 +0100975 struct device *class_dev = NULL;
James Bottomley39dca552007-07-20 18:22:17 -0500976 const char *devname;
977
978 if (name)
979 devname = name;
980 else
Kay Sievers3ada8b72009-01-06 10:44:43 -0800981 devname = dev_name(parent);
Jens Axboe3d6392c2007-07-09 12:38:05 +0200982
983 /*
984 * we need a proper transport to send commands, not a stacked device
985 */
Jens Axboe49fd5242014-04-16 10:57:18 -0600986 if (!queue_is_rq_based(q))
Jens Axboe3d6392c2007-07-09 12:38:05 +0200987 return 0;
988
FUJITA Tomonorid351af02007-07-09 12:40:35 +0200989 bcd = &q->bsg_dev;
Jens Axboe3d6392c2007-07-09 12:38:05 +0200990 memset(bcd, 0, sizeof(*bcd));
Jens Axboe3d6392c2007-07-09 12:38:05 +0200991
992 mutex_lock(&bsg_mutex);
FUJITA Tomonori598443a2007-07-23 09:33:26 +0900993
Tejun Heobab998d2013-02-27 17:03:57 -0800994 ret = idr_alloc(&bsg_minor_idr, bcd, 0, BSG_MAX_DEVS, GFP_KERNEL);
995 if (ret < 0) {
996 if (ret == -ENOSPC) {
997 printk(KERN_ERR "bsg: too many bsg devices\n");
998 ret = -EINVAL;
999 }
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001000 goto unlock;
1001 }
1002
Tejun Heobab998d2013-02-27 17:03:57 -08001003 bcd->minor = ret;
FUJITA Tomonorid351af02007-07-09 12:40:35 +02001004 bcd->queue = q;
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +09001005 bcd->parent = get_device(parent);
1006 bcd->release = release;
1007 kref_init(&bcd->ref);
Jens Axboe46f6ef42007-07-17 08:56:10 +02001008 dev = MKDEV(bsg_major, bcd->minor);
Greg Kroah-Hartman1ff9f542008-07-21 20:03:34 -07001009 class_dev = device_create(bsg_class, parent, dev, NULL, "%s", devname);
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001010 if (IS_ERR(class_dev)) {
1011 ret = PTR_ERR(class_dev);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001012 goto put_dev;
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001013 }
1014 bcd->class_dev = class_dev;
1015
Linus Torvaldsabce8912007-07-16 11:18:23 -07001016 if (q->kobj.sd) {
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001017 ret = sysfs_create_link(&q->kobj, &bcd->class_dev->kobj, "bsg");
1018 if (ret)
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001019 goto unregister_class_dev;
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001020 }
1021
Jens Axboe3d6392c2007-07-09 12:38:05 +02001022 mutex_unlock(&bsg_mutex);
1023 return 0;
James Bottomley6826ee42007-07-20 16:50:10 -05001024
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001025unregister_class_dev:
Tony Jonesee959b02008-02-22 00:13:36 +01001026 device_unregister(class_dev);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001027put_dev:
FUJITA Tomonori97f46ae2008-04-19 00:43:14 +09001028 put_device(parent);
Tejun Heobab998d2013-02-27 17:03:57 -08001029 idr_remove(&bsg_minor_idr, bcd->minor);
FUJITA Tomonori598443a2007-07-23 09:33:26 +09001030unlock:
Jens Axboe264a0472007-01-23 16:30:17 +01001031 mutex_unlock(&bsg_mutex);
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001032 return ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001033}
FUJITA Tomonori4cf07232007-03-30 11:19:39 +02001034EXPORT_SYMBOL_GPL(bsg_register_queue);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001035
Greg Kroah-Hartman7e7654a2007-09-12 15:06:57 -07001036static struct cdev bsg_cdev;
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001037
Al Viro2c9ede52011-07-23 20:24:48 -04001038static char *bsg_devnode(struct device *dev, umode_t *mode)
Kay Sievers2bdf9142009-04-30 15:23:42 +02001039{
1040 return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
1041}
1042
Jens Axboe3d6392c2007-07-09 12:38:05 +02001043static int __init bsg_init(void)
1044{
1045 int ret, i;
Jens Axboe46f6ef42007-07-17 08:56:10 +02001046 dev_t devid;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001047
Jens Axboe5309cb32007-01-23 16:24:41 +01001048 bsg_cmd_cachep = kmem_cache_create("bsg_cmd",
Paul Mundt20c2df82007-07-20 10:11:58 +09001049 sizeof(struct bsg_command), 0, 0, NULL);
Jens Axboe5309cb32007-01-23 16:24:41 +01001050 if (!bsg_cmd_cachep) {
1051 printk(KERN_ERR "bsg: failed creating slab cache\n");
1052 return -ENOMEM;
1053 }
1054
Jens Axboe25fd1642007-07-17 08:52:29 +02001055 for (i = 0; i < BSG_LIST_ARRAY_SIZE; i++)
Jens Axboe3d6392c2007-07-09 12:38:05 +02001056 INIT_HLIST_HEAD(&bsg_device_list[i]);
1057
1058 bsg_class = class_create(THIS_MODULE, "bsg");
Jens Axboe5309cb32007-01-23 16:24:41 +01001059 if (IS_ERR(bsg_class)) {
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001060 ret = PTR_ERR(bsg_class);
1061 goto destroy_kmemcache;
Jens Axboe5309cb32007-01-23 16:24:41 +01001062 }
Kay Sieverse454cea2009-09-18 23:01:12 +02001063 bsg_class->devnode = bsg_devnode;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001064
Jens Axboe46f6ef42007-07-17 08:56:10 +02001065 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001066 if (ret)
1067 goto destroy_bsg_class;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001068
Jens Axboe46f6ef42007-07-17 08:56:10 +02001069 bsg_major = MAJOR(devid);
1070
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001071 cdev_init(&bsg_cdev, &bsg_fops);
Jens Axboe46f6ef42007-07-17 08:56:10 +02001072 ret = cdev_add(&bsg_cdev, MKDEV(bsg_major, 0), BSG_MAX_DEVS);
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001073 if (ret)
1074 goto unregister_chrdev;
FUJITA Tomonori292b7f22007-03-28 13:29:58 +02001075
Jens Axboe5d3a8cd2007-07-17 15:10:09 +02001076 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
FUJITA Tomonori0ed081c2007-07-17 12:21:35 +02001077 " loaded (major %d)\n", bsg_major);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001078 return 0;
FUJITA Tomonori9b9f7702007-07-17 12:20:46 +02001079unregister_chrdev:
1080 unregister_chrdev_region(MKDEV(bsg_major, 0), BSG_MAX_DEVS);
1081destroy_bsg_class:
1082 class_destroy(bsg_class);
1083destroy_kmemcache:
1084 kmem_cache_destroy(bsg_cmd_cachep);
1085 return ret;
Jens Axboe3d6392c2007-07-09 12:38:05 +02001086}
1087
1088MODULE_AUTHOR("Jens Axboe");
FUJITA Tomonori0ed081c2007-07-17 12:21:35 +02001089MODULE_DESCRIPTION(BSG_DESCRIPTION);
Jens Axboe3d6392c2007-07-09 12:38:05 +02001090MODULE_LICENSE("GPL");
1091
FUJITA Tomonori4e2872d2007-03-28 13:29:24 +02001092device_initcall(bsg_init);