1 // SPDX-License-Identifier: GPL-2.0 1 // SPDX-License-Identifier: GPL-2.0
2 /* 2 /*
3 * bsg.c - block layer implementation of the s 3 * bsg.c - block layer implementation of the sg v4 interface
4 */ 4 */
5 #include <linux/module.h> 5 #include <linux/module.h>
6 #include <linux/init.h> 6 #include <linux/init.h>
7 #include <linux/file.h> 7 #include <linux/file.h>
8 #include <linux/blkdev.h> 8 #include <linux/blkdev.h>
9 #include <linux/cdev.h> 9 #include <linux/cdev.h>
10 #include <linux/jiffies.h> 10 #include <linux/jiffies.h>
11 #include <linux/percpu.h> 11 #include <linux/percpu.h>
12 #include <linux/idr.h> 12 #include <linux/idr.h>
13 #include <linux/bsg.h> 13 #include <linux/bsg.h>
14 #include <linux/slab.h> 14 #include <linux/slab.h>
15 15
16 #include <scsi/scsi.h> 16 #include <scsi/scsi.h>
17 #include <scsi/scsi_ioctl.h> 17 #include <scsi/scsi_ioctl.h>
18 #include <scsi/sg.h> 18 #include <scsi/sg.h>
19 19
20 #define BSG_DESCRIPTION "Block layer SCSI gene 20 #define BSG_DESCRIPTION "Block layer SCSI generic (bsg) driver"
21 #define BSG_VERSION "0.4" 21 #define BSG_VERSION "0.4"
22 22
23 struct bsg_device { 23 struct bsg_device {
24 struct request_queue *queue; 24 struct request_queue *queue;
25 struct device device; 25 struct device device;
26 struct cdev cdev; 26 struct cdev cdev;
27 int max_queue; 27 int max_queue;
28 unsigned int timeout; 28 unsigned int timeout;
29 unsigned int reserved_size; 29 unsigned int reserved_size;
30 bsg_sg_io_fn *sg_io_fn; 30 bsg_sg_io_fn *sg_io_fn;
31 }; 31 };
32 32
33 static inline struct bsg_device *to_bsg_device 33 static inline struct bsg_device *to_bsg_device(struct inode *inode)
34 { 34 {
35 return container_of(inode->i_cdev, str 35 return container_of(inode->i_cdev, struct bsg_device, cdev);
36 } 36 }
37 37
38 #define BSG_DEFAULT_CMDS 64 38 #define BSG_DEFAULT_CMDS 64
39 #define BSG_MAX_DEVS (1 << MINORBIT !! 39 #define BSG_MAX_DEVS 32768
40 40
41 static DEFINE_IDA(bsg_minor_ida); 41 static DEFINE_IDA(bsg_minor_ida);
42 static const struct class bsg_class; !! 42 static struct class *bsg_class;
43 static int bsg_major; 43 static int bsg_major;
44 44
45 static unsigned int bsg_timeout(struct bsg_dev 45 static unsigned int bsg_timeout(struct bsg_device *bd, struct sg_io_v4 *hdr)
46 { 46 {
47 unsigned int timeout = BLK_DEFAULT_SG_ 47 unsigned int timeout = BLK_DEFAULT_SG_TIMEOUT;
48 48
49 if (hdr->timeout) 49 if (hdr->timeout)
50 timeout = msecs_to_jiffies(hdr 50 timeout = msecs_to_jiffies(hdr->timeout);
51 else if (bd->timeout) 51 else if (bd->timeout)
52 timeout = bd->timeout; 52 timeout = bd->timeout;
53 53
54 return max_t(unsigned int, timeout, BL 54 return max_t(unsigned int, timeout, BLK_MIN_SG_TIMEOUT);
55 } 55 }
56 56
57 static int bsg_sg_io(struct bsg_device *bd, bo !! 57 static int bsg_sg_io(struct bsg_device *bd, fmode_t mode, void __user *uarg)
58 void __user *uarg) <<
59 { 58 {
60 struct sg_io_v4 hdr; 59 struct sg_io_v4 hdr;
61 int ret; 60 int ret;
62 61
63 if (copy_from_user(&hdr, uarg, sizeof( 62 if (copy_from_user(&hdr, uarg, sizeof(hdr)))
64 return -EFAULT; 63 return -EFAULT;
65 if (hdr.guard != 'Q') 64 if (hdr.guard != 'Q')
66 return -EINVAL; 65 return -EINVAL;
67 ret = bd->sg_io_fn(bd->queue, &hdr, op !! 66 ret = bd->sg_io_fn(bd->queue, &hdr, mode, bsg_timeout(bd, &hdr));
68 bsg_timeout(bd, &hd <<
69 if (!ret && copy_to_user(uarg, &hdr, s 67 if (!ret && copy_to_user(uarg, &hdr, sizeof(hdr)))
70 return -EFAULT; 68 return -EFAULT;
71 return ret; 69 return ret;
72 } 70 }
73 71
74 static int bsg_open(struct inode *inode, struc 72 static int bsg_open(struct inode *inode, struct file *file)
75 { 73 {
76 if (!blk_get_queue(to_bsg_device(inode 74 if (!blk_get_queue(to_bsg_device(inode)->queue))
77 return -ENXIO; 75 return -ENXIO;
78 return 0; 76 return 0;
79 } 77 }
80 78
81 static int bsg_release(struct inode *inode, st 79 static int bsg_release(struct inode *inode, struct file *file)
82 { 80 {
83 blk_put_queue(to_bsg_device(inode)->qu 81 blk_put_queue(to_bsg_device(inode)->queue);
84 return 0; 82 return 0;
85 } 83 }
86 84
87 static int bsg_get_command_q(struct bsg_device 85 static int bsg_get_command_q(struct bsg_device *bd, int __user *uarg)
88 { 86 {
89 return put_user(READ_ONCE(bd->max_queu 87 return put_user(READ_ONCE(bd->max_queue), uarg);
90 } 88 }
91 89
92 static int bsg_set_command_q(struct bsg_device 90 static int bsg_set_command_q(struct bsg_device *bd, int __user *uarg)
93 { 91 {
94 int max_queue; 92 int max_queue;
95 93
96 if (get_user(max_queue, uarg)) 94 if (get_user(max_queue, uarg))
97 return -EFAULT; 95 return -EFAULT;
98 if (max_queue < 1) 96 if (max_queue < 1)
99 return -EINVAL; 97 return -EINVAL;
100 WRITE_ONCE(bd->max_queue, max_queue); 98 WRITE_ONCE(bd->max_queue, max_queue);
101 return 0; 99 return 0;
102 } 100 }
103 101
104 static long bsg_ioctl(struct file *file, unsig 102 static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
105 { 103 {
106 struct bsg_device *bd = to_bsg_device( 104 struct bsg_device *bd = to_bsg_device(file_inode(file));
107 struct request_queue *q = bd->queue; 105 struct request_queue *q = bd->queue;
108 void __user *uarg = (void __user *) ar 106 void __user *uarg = (void __user *) arg;
109 int __user *intp = uarg; 107 int __user *intp = uarg;
110 int val; 108 int val;
111 109
112 switch (cmd) { 110 switch (cmd) {
113 /* 111 /*
114 * Our own ioctls 112 * Our own ioctls
115 */ 113 */
116 case SG_GET_COMMAND_Q: 114 case SG_GET_COMMAND_Q:
117 return bsg_get_command_q(bd, u 115 return bsg_get_command_q(bd, uarg);
118 case SG_SET_COMMAND_Q: 116 case SG_SET_COMMAND_Q:
119 return bsg_set_command_q(bd, u 117 return bsg_set_command_q(bd, uarg);
120 118
121 /* 119 /*
122 * SCSI/sg ioctls 120 * SCSI/sg ioctls
123 */ 121 */
124 case SG_GET_VERSION_NUM: 122 case SG_GET_VERSION_NUM:
125 return put_user(30527, intp); 123 return put_user(30527, intp);
126 case SCSI_IOCTL_GET_IDLUN: 124 case SCSI_IOCTL_GET_IDLUN:
127 return put_user(0, intp); 125 return put_user(0, intp);
128 case SCSI_IOCTL_GET_BUS_NUMBER: 126 case SCSI_IOCTL_GET_BUS_NUMBER:
129 return put_user(0, intp); 127 return put_user(0, intp);
130 case SG_SET_TIMEOUT: 128 case SG_SET_TIMEOUT:
131 if (get_user(val, intp)) 129 if (get_user(val, intp))
132 return -EFAULT; 130 return -EFAULT;
133 bd->timeout = clock_t_to_jiffi 131 bd->timeout = clock_t_to_jiffies(val);
134 return 0; 132 return 0;
135 case SG_GET_TIMEOUT: 133 case SG_GET_TIMEOUT:
136 return jiffies_to_clock_t(bd-> 134 return jiffies_to_clock_t(bd->timeout);
137 case SG_GET_RESERVED_SIZE: 135 case SG_GET_RESERVED_SIZE:
138 return put_user(min(bd->reserv 136 return put_user(min(bd->reserved_size, queue_max_bytes(q)),
139 intp); 137 intp);
140 case SG_SET_RESERVED_SIZE: 138 case SG_SET_RESERVED_SIZE:
141 if (get_user(val, intp)) 139 if (get_user(val, intp))
142 return -EFAULT; 140 return -EFAULT;
143 if (val < 0) 141 if (val < 0)
144 return -EINVAL; 142 return -EINVAL;
145 bd->reserved_size = 143 bd->reserved_size =
146 min_t(unsigned int, va 144 min_t(unsigned int, val, queue_max_bytes(q));
147 return 0; 145 return 0;
148 case SG_EMULATED_HOST: 146 case SG_EMULATED_HOST:
149 return put_user(1, intp); 147 return put_user(1, intp);
150 case SG_IO: 148 case SG_IO:
151 return bsg_sg_io(bd, file->f_m !! 149 return bsg_sg_io(bd, file->f_mode, uarg);
152 case SCSI_IOCTL_SEND_COMMAND: 150 case SCSI_IOCTL_SEND_COMMAND:
153 pr_warn_ratelimited("%s: calli 151 pr_warn_ratelimited("%s: calling unsupported SCSI_IOCTL_SEND_COMMAND\n",
154 current->comm) 152 current->comm);
155 return -EINVAL; 153 return -EINVAL;
156 default: 154 default:
157 return -ENOTTY; 155 return -ENOTTY;
158 } 156 }
159 } 157 }
160 158
161 static const struct file_operations bsg_fops = 159 static const struct file_operations bsg_fops = {
162 .open = bsg_open, 160 .open = bsg_open,
163 .release = bsg_release, 161 .release = bsg_release,
164 .unlocked_ioctl = bsg_ioctl, 162 .unlocked_ioctl = bsg_ioctl,
165 .compat_ioctl = compat_ptr_ioc 163 .compat_ioctl = compat_ptr_ioctl,
166 .owner = THIS_MODULE, 164 .owner = THIS_MODULE,
167 .llseek = default_llseek 165 .llseek = default_llseek,
168 }; 166 };
169 167
170 static void bsg_device_release(struct device * 168 static void bsg_device_release(struct device *dev)
171 { 169 {
172 struct bsg_device *bd = container_of(d 170 struct bsg_device *bd = container_of(dev, struct bsg_device, device);
173 171
174 ida_free(&bsg_minor_ida, MINOR(bd->dev !! 172 ida_simple_remove(&bsg_minor_ida, MINOR(bd->device.devt));
175 kfree(bd); 173 kfree(bd);
176 } 174 }
177 175
178 void bsg_unregister_queue(struct bsg_device *b 176 void bsg_unregister_queue(struct bsg_device *bd)
179 { 177 {
180 struct gendisk *disk = bd->queue->disk !! 178 if (bd->queue->kobj.sd)
181 !! 179 sysfs_remove_link(&bd->queue->kobj, "bsg");
182 if (disk && disk->queue_kobj.sd) <<
183 sysfs_remove_link(&disk->queue <<
184 cdev_device_del(&bd->cdev, &bd->device 180 cdev_device_del(&bd->cdev, &bd->device);
185 put_device(&bd->device); 181 put_device(&bd->device);
186 } 182 }
187 EXPORT_SYMBOL_GPL(bsg_unregister_queue); 183 EXPORT_SYMBOL_GPL(bsg_unregister_queue);
188 184
189 struct bsg_device *bsg_register_queue(struct r 185 struct bsg_device *bsg_register_queue(struct request_queue *q,
190 struct device *parent, const c 186 struct device *parent, const char *name, bsg_sg_io_fn *sg_io_fn)
191 { 187 {
192 struct bsg_device *bd; 188 struct bsg_device *bd;
193 int ret; 189 int ret;
194 190
195 bd = kzalloc(sizeof(*bd), GFP_KERNEL); 191 bd = kzalloc(sizeof(*bd), GFP_KERNEL);
196 if (!bd) 192 if (!bd)
197 return ERR_PTR(-ENOMEM); 193 return ERR_PTR(-ENOMEM);
198 bd->max_queue = BSG_DEFAULT_CMDS; 194 bd->max_queue = BSG_DEFAULT_CMDS;
199 bd->reserved_size = INT_MAX; 195 bd->reserved_size = INT_MAX;
200 bd->queue = q; 196 bd->queue = q;
201 bd->sg_io_fn = sg_io_fn; 197 bd->sg_io_fn = sg_io_fn;
202 198
203 ret = ida_alloc_max(&bsg_minor_ida, BS !! 199 ret = ida_simple_get(&bsg_minor_ida, 0, BSG_MAX_DEVS, GFP_KERNEL);
204 if (ret < 0) { 200 if (ret < 0) {
205 if (ret == -ENOSPC) 201 if (ret == -ENOSPC)
206 dev_err(parent, "bsg: 202 dev_err(parent, "bsg: too many bsg devices\n");
207 kfree(bd); 203 kfree(bd);
208 return ERR_PTR(ret); 204 return ERR_PTR(ret);
209 } 205 }
210 bd->device.devt = MKDEV(bsg_major, ret 206 bd->device.devt = MKDEV(bsg_major, ret);
211 bd->device.class = &bsg_class; !! 207 bd->device.class = bsg_class;
212 bd->device.parent = parent; 208 bd->device.parent = parent;
213 bd->device.release = bsg_device_releas 209 bd->device.release = bsg_device_release;
214 dev_set_name(&bd->device, "%s", name); 210 dev_set_name(&bd->device, "%s", name);
215 device_initialize(&bd->device); 211 device_initialize(&bd->device);
216 212
217 cdev_init(&bd->cdev, &bsg_fops); 213 cdev_init(&bd->cdev, &bsg_fops);
218 bd->cdev.owner = THIS_MODULE; 214 bd->cdev.owner = THIS_MODULE;
219 ret = cdev_device_add(&bd->cdev, &bd-> 215 ret = cdev_device_add(&bd->cdev, &bd->device);
220 if (ret) 216 if (ret)
221 goto out_put_device; 217 goto out_put_device;
222 218
223 if (q->disk && q->disk->queue_kobj.sd) !! 219 if (q->kobj.sd) {
224 ret = sysfs_create_link(&q->di !! 220 ret = sysfs_create_link(&q->kobj, &bd->device.kobj, "bsg");
225 "bsg") <<
226 if (ret) 221 if (ret)
227 goto out_device_del; 222 goto out_device_del;
228 } 223 }
229 224
230 return bd; 225 return bd;
231 226
232 out_device_del: 227 out_device_del:
233 cdev_device_del(&bd->cdev, &bd->device 228 cdev_device_del(&bd->cdev, &bd->device);
234 out_put_device: 229 out_put_device:
235 put_device(&bd->device); 230 put_device(&bd->device);
236 return ERR_PTR(ret); 231 return ERR_PTR(ret);
237 } 232 }
238 EXPORT_SYMBOL_GPL(bsg_register_queue); 233 EXPORT_SYMBOL_GPL(bsg_register_queue);
239 234
240 static char *bsg_devnode(const struct device * !! 235 static char *bsg_devnode(struct device *dev, umode_t *mode)
241 { 236 {
242 return kasprintf(GFP_KERNEL, "bsg/%s", 237 return kasprintf(GFP_KERNEL, "bsg/%s", dev_name(dev));
243 } 238 }
244 239
245 static const struct class bsg_class = { <<
246 .name = "bsg", <<
247 .devnode = bsg_devnode, <<
248 }; <<
249 <<
250 static int __init bsg_init(void) 240 static int __init bsg_init(void)
251 { 241 {
252 dev_t devid; 242 dev_t devid;
253 int ret; 243 int ret;
254 244
255 ret = class_register(&bsg_class); !! 245 bsg_class = class_create(THIS_MODULE, "bsg");
256 if (ret) !! 246 if (IS_ERR(bsg_class))
257 return ret; !! 247 return PTR_ERR(bsg_class);
>> 248 bsg_class->devnode = bsg_devnode;
258 249
259 ret = alloc_chrdev_region(&devid, 0, B 250 ret = alloc_chrdev_region(&devid, 0, BSG_MAX_DEVS, "bsg");
260 if (ret) 251 if (ret)
261 goto destroy_bsg_class; 252 goto destroy_bsg_class;
262 bsg_major = MAJOR(devid); 253 bsg_major = MAJOR(devid);
263 254
264 printk(KERN_INFO BSG_DESCRIPTION " ver 255 printk(KERN_INFO BSG_DESCRIPTION " version " BSG_VERSION
265 " loaded (major %d)\n", bsg_maj 256 " loaded (major %d)\n", bsg_major);
266 return 0; 257 return 0;
267 258
268 destroy_bsg_class: 259 destroy_bsg_class:
269 class_unregister(&bsg_class); !! 260 class_destroy(bsg_class);
270 return ret; 261 return ret;
271 } 262 }
272 263
273 MODULE_AUTHOR("Jens Axboe"); 264 MODULE_AUTHOR("Jens Axboe");
274 MODULE_DESCRIPTION(BSG_DESCRIPTION); 265 MODULE_DESCRIPTION(BSG_DESCRIPTION);
275 MODULE_LICENSE("GPL"); 266 MODULE_LICENSE("GPL");
276 267
277 device_initcall(bsg_init); 268 device_initcall(bsg_init);
278 269
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