xref: /linux/drivers/scsi/scsi_proc.c (revision a1c613ae4c322ddd58d5a8539dbfba2a0380a8c0)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * linux/drivers/scsi/scsi_proc.c
4  *
5  * The functions in this file provide an interface between
6  * the PROC file system and the SCSI device drivers
7  * It is mainly used for debugging, statistics and to pass
8  * information directly to the lowlevel driver.
9  *
10  * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de
11  * Version: 0.99.8   last change: 95/09/13
12  *
13  * generic command parser provided by:
14  * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
15  *
16  * generic_proc_info() support of xxxx_info() by:
17  * Michael A. Griffith <grif@acm.org>
18  */
19 
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/string.h>
23 #include <linux/mm.h>
24 #include <linux/proc_fs.h>
25 #include <linux/errno.h>
26 #include <linux/blkdev.h>
27 #include <linux/seq_file.h>
28 #include <linux/mutex.h>
29 #include <linux/gfp.h>
30 #include <linux/uaccess.h>
31 
32 #include <scsi/scsi.h>
33 #include <scsi/scsi_device.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_transport.h>
36 
37 #include "scsi_priv.h"
38 #include "scsi_logging.h"
39 
40 
41 /* 4K page size, but our output routines, use some slack for overruns */
42 #define PROC_BLOCK_SIZE (3*1024)
43 
44 static struct proc_dir_entry *proc_scsi;
45 
46 /* Protects scsi_proc_list */
47 static DEFINE_MUTEX(global_host_template_mutex);
48 static LIST_HEAD(scsi_proc_list);
49 
50 /**
51  * struct scsi_proc_entry - (host template, SCSI proc dir) association
52  * @entry: entry in scsi_proc_list.
53  * @sht: SCSI host template associated with the procfs directory.
54  * @proc_dir: procfs directory associated with the SCSI host template.
55  * @present: Number of SCSI hosts instantiated for @sht.
56  */
57 struct scsi_proc_entry {
58 	struct list_head	entry;
59 	const struct scsi_host_template *sht;
60 	struct proc_dir_entry	*proc_dir;
61 	unsigned int		present;
62 };
63 
proc_scsi_host_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)64 static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
65                            size_t count, loff_t *ppos)
66 {
67 	struct Scsi_Host *shost = pde_data(file_inode(file));
68 	ssize_t ret = -ENOMEM;
69 	char *page;
70 
71 	if (count > PROC_BLOCK_SIZE)
72 		return -EOVERFLOW;
73 
74 	if (!shost->hostt->write_info)
75 		return -EINVAL;
76 
77 	page = (char *)__get_free_page(GFP_KERNEL);
78 	if (page) {
79 		ret = -EFAULT;
80 		if (copy_from_user(page, buf, count))
81 			goto out;
82 		ret = shost->hostt->write_info(shost, page, count);
83 	}
84 out:
85 	free_page((unsigned long)page);
86 	return ret;
87 }
88 
proc_scsi_show(struct seq_file * m,void * v)89 static int proc_scsi_show(struct seq_file *m, void *v)
90 {
91 	struct Scsi_Host *shost = m->private;
92 	return shost->hostt->show_info(m, shost);
93 }
94 
proc_scsi_host_open(struct inode * inode,struct file * file)95 static int proc_scsi_host_open(struct inode *inode, struct file *file)
96 {
97 	return single_open_size(file, proc_scsi_show, pde_data(inode),
98 				4 * PAGE_SIZE);
99 }
100 
101 static struct scsi_proc_entry *
__scsi_lookup_proc_entry(const struct scsi_host_template * sht)102 __scsi_lookup_proc_entry(const struct scsi_host_template *sht)
103 {
104 	struct scsi_proc_entry *e;
105 
106 	lockdep_assert_held(&global_host_template_mutex);
107 
108 	list_for_each_entry(e, &scsi_proc_list, entry)
109 		if (e->sht == sht)
110 			return e;
111 
112 	return NULL;
113 }
114 
115 static struct scsi_proc_entry *
scsi_lookup_proc_entry(const struct scsi_host_template * sht)116 scsi_lookup_proc_entry(const struct scsi_host_template *sht)
117 {
118 	struct scsi_proc_entry *e;
119 
120 	mutex_lock(&global_host_template_mutex);
121 	e = __scsi_lookup_proc_entry(sht);
122 	mutex_unlock(&global_host_template_mutex);
123 
124 	return e;
125 }
126 
127 /**
128  * scsi_template_proc_dir() - returns the procfs dir for a SCSI host template
129  * @sht: SCSI host template pointer.
130  */
131 struct proc_dir_entry *
scsi_template_proc_dir(const struct scsi_host_template * sht)132 scsi_template_proc_dir(const struct scsi_host_template *sht)
133 {
134 	struct scsi_proc_entry *e = scsi_lookup_proc_entry(sht);
135 
136 	return e ? e->proc_dir : NULL;
137 }
138 EXPORT_SYMBOL_GPL(scsi_template_proc_dir);
139 
140 static const struct proc_ops proc_scsi_ops = {
141 	.proc_open	= proc_scsi_host_open,
142 	.proc_release	= single_release,
143 	.proc_read	= seq_read,
144 	.proc_lseek	= seq_lseek,
145 	.proc_write	= proc_scsi_host_write
146 };
147 
148 /**
149  * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
150  * @sht: owner of this directory
151  *
152  * Sets sht->proc_dir to the new directory.
153  */
scsi_proc_hostdir_add(const struct scsi_host_template * sht)154 int scsi_proc_hostdir_add(const struct scsi_host_template *sht)
155 {
156 	struct scsi_proc_entry *e;
157 	int ret;
158 
159 	if (!sht->show_info)
160 		return 0;
161 
162 	mutex_lock(&global_host_template_mutex);
163 	e = __scsi_lookup_proc_entry(sht);
164 	if (!e) {
165 		e = kzalloc(sizeof(*e), GFP_KERNEL);
166 		if (!e) {
167 			ret = -ENOMEM;
168 			goto unlock;
169 		}
170 	}
171 	if (e->present++)
172 		goto success;
173 	e->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
174 	if (!e->proc_dir) {
175 		printk(KERN_ERR "%s: proc_mkdir failed for %s\n", __func__,
176 		       sht->proc_name);
177 		ret = -ENOMEM;
178 		goto unlock;
179 	}
180 	e->sht = sht;
181 	list_add_tail(&e->entry, &scsi_proc_list);
182 success:
183 	e = NULL;
184 	ret = 0;
185 unlock:
186 	mutex_unlock(&global_host_template_mutex);
187 
188 	kfree(e);
189 	return ret;
190 }
191 
192 /**
193  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
194  * @sht: owner of directory
195  */
scsi_proc_hostdir_rm(const struct scsi_host_template * sht)196 void scsi_proc_hostdir_rm(const struct scsi_host_template *sht)
197 {
198 	struct scsi_proc_entry *e;
199 
200 	if (!sht->show_info)
201 		return;
202 
203 	mutex_lock(&global_host_template_mutex);
204 	e = __scsi_lookup_proc_entry(sht);
205 	if (e && !--e->present) {
206 		remove_proc_entry(sht->proc_name, proc_scsi);
207 		list_del(&e->entry);
208 		kfree(e);
209 	}
210 	mutex_unlock(&global_host_template_mutex);
211 }
212 
213 
214 /**
215  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
216  * @shost: host to add
217  */
scsi_proc_host_add(struct Scsi_Host * shost)218 void scsi_proc_host_add(struct Scsi_Host *shost)
219 {
220 	const struct scsi_host_template *sht = shost->hostt;
221 	struct scsi_proc_entry *e;
222 	struct proc_dir_entry *p;
223 	char name[10];
224 
225 	if (!sht->show_info)
226 		return;
227 
228 	e = scsi_lookup_proc_entry(sht);
229 	if (!e)
230 		goto err;
231 
232 	sprintf(name,"%d", shost->host_no);
233 	p = proc_create_data(name, S_IRUGO | S_IWUSR, e->proc_dir,
234 			     &proc_scsi_ops, shost);
235 	if (!p)
236 		goto err;
237 	return;
238 
239 err:
240 	shost_printk(KERN_ERR, shost,
241 		     "%s: Failed to register host (%s failed)\n", __func__,
242 		     e ? "proc_create_data()" : "scsi_proc_hostdir_add()");
243 }
244 
245 /**
246  * scsi_proc_host_rm - remove this host's entry from /proc
247  * @shost: which host
248  */
scsi_proc_host_rm(struct Scsi_Host * shost)249 void scsi_proc_host_rm(struct Scsi_Host *shost)
250 {
251 	const struct scsi_host_template *sht = shost->hostt;
252 	struct scsi_proc_entry *e;
253 	char name[10];
254 
255 	if (!sht->show_info)
256 		return;
257 
258 	e = scsi_lookup_proc_entry(sht);
259 	if (!e)
260 		return;
261 
262 	sprintf(name,"%d", shost->host_no);
263 	remove_proc_entry(name, e->proc_dir);
264 }
265 /**
266  * proc_print_scsidevice - return data about this host
267  * @dev: A scsi device
268  * @data: &struct seq_file to output to.
269  *
270  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
271  * and revision.
272  */
proc_print_scsidevice(struct device * dev,void * data)273 static int proc_print_scsidevice(struct device *dev, void *data)
274 {
275 	struct scsi_device *sdev;
276 	struct seq_file *s = data;
277 	int i;
278 
279 	if (!scsi_is_sdev_device(dev))
280 		goto out;
281 
282 	sdev = to_scsi_device(dev);
283 	seq_printf(s,
284 		"Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n  Vendor: ",
285 		sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
286 	for (i = 0; i < 8; i++) {
287 		if (sdev->vendor[i] >= 0x20)
288 			seq_putc(s, sdev->vendor[i]);
289 		else
290 			seq_putc(s, ' ');
291 	}
292 
293 	seq_puts(s, " Model: ");
294 	for (i = 0; i < 16; i++) {
295 		if (sdev->model[i] >= 0x20)
296 			seq_putc(s, sdev->model[i]);
297 		else
298 			seq_putc(s, ' ');
299 	}
300 
301 	seq_puts(s, " Rev: ");
302 	for (i = 0; i < 4; i++) {
303 		if (sdev->rev[i] >= 0x20)
304 			seq_putc(s, sdev->rev[i]);
305 		else
306 			seq_putc(s, ' ');
307 	}
308 
309 	seq_putc(s, '\n');
310 
311 	seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
312 	seq_printf(s, "               ANSI  SCSI revision: %02x",
313 			sdev->scsi_level - (sdev->scsi_level > 1));
314 	if (sdev->scsi_level == 2)
315 		seq_puts(s, " CCS\n");
316 	else
317 		seq_putc(s, '\n');
318 
319 out:
320 	return 0;
321 }
322 
323 /**
324  * scsi_add_single_device - Respond to user request to probe for/add device
325  * @host: user-supplied decimal integer
326  * @channel: user-supplied decimal integer
327  * @id: user-supplied decimal integer
328  * @lun: user-supplied decimal integer
329  *
330  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
331  *
332  * does scsi_host_lookup() and either user_scan() if that transport
333  * type supports it, or else scsi_scan_host_selected()
334  *
335  * Note: this seems to be aimed exclusively at SCSI parallel busses.
336  */
337 
scsi_add_single_device(uint host,uint channel,uint id,uint lun)338 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
339 {
340 	struct Scsi_Host *shost;
341 	int error = -ENXIO;
342 
343 	shost = scsi_host_lookup(host);
344 	if (!shost)
345 		return error;
346 
347 	if (shost->transportt->user_scan)
348 		error = shost->transportt->user_scan(shost, channel, id, lun);
349 	else
350 		error = scsi_scan_host_selected(shost, channel, id, lun,
351 						SCSI_SCAN_MANUAL);
352 	scsi_host_put(shost);
353 	return error;
354 }
355 
356 /**
357  * scsi_remove_single_device - Respond to user request to remove a device
358  * @host: user-supplied decimal integer
359  * @channel: user-supplied decimal integer
360  * @id: user-supplied decimal integer
361  * @lun: user-supplied decimal integer
362  *
363  * Description: called by writing "scsi remove-single-device" to
364  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
365  */
scsi_remove_single_device(uint host,uint channel,uint id,uint lun)366 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
367 {
368 	struct scsi_device *sdev;
369 	struct Scsi_Host *shost;
370 	int error = -ENXIO;
371 
372 	shost = scsi_host_lookup(host);
373 	if (!shost)
374 		return error;
375 	sdev = scsi_device_lookup(shost, channel, id, lun);
376 	if (sdev) {
377 		scsi_remove_device(sdev);
378 		scsi_device_put(sdev);
379 		error = 0;
380 	}
381 
382 	scsi_host_put(shost);
383 	return error;
384 }
385 
386 /**
387  * proc_scsi_write - handle writes to /proc/scsi/scsi
388  * @file: not used
389  * @buf: buffer to write
390  * @length: length of buf, at most PAGE_SIZE
391  * @ppos: not used
392  *
393  * Description: this provides a legacy mechanism to add or remove devices by
394  * Host, Channel, ID, and Lun.  To use,
395  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
396  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
397  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
398  *
399  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
400  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
401  * provide a unique identifier and nothing more.
402  */
403 
404 
proc_scsi_write(struct file * file,const char __user * buf,size_t length,loff_t * ppos)405 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
406 			       size_t length, loff_t *ppos)
407 {
408 	int host, channel, id, lun;
409 	char *buffer, *end, *p;
410 	int err;
411 
412 	if (!buf || length > PAGE_SIZE)
413 		return -EINVAL;
414 
415 	buffer = (char *)__get_free_page(GFP_KERNEL);
416 	if (!buffer)
417 		return -ENOMEM;
418 
419 	err = -EFAULT;
420 	if (copy_from_user(buffer, buf, length))
421 		goto out;
422 
423 	err = -EINVAL;
424 	if (length < PAGE_SIZE) {
425 		end = buffer + length;
426 		*end = '\0';
427 	} else {
428 		end = buffer + PAGE_SIZE - 1;
429 		if (*end)
430 			goto out;
431 	}
432 
433 	/*
434 	 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
435 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
436 	 */
437 	if (!strncmp("scsi add-single-device", buffer, 22)) {
438 		p = buffer + 23;
439 
440 		host    = (p     < end) ? simple_strtoul(p, &p, 0) : 0;
441 		channel = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
442 		id      = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
443 		lun     = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
444 
445 		err = scsi_add_single_device(host, channel, id, lun);
446 
447 	/*
448 	 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
449 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
450 	 */
451 	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
452 		p = buffer + 26;
453 
454 		host    = (p     < end) ? simple_strtoul(p, &p, 0) : 0;
455 		channel = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
456 		id      = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
457 		lun     = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
458 
459 		err = scsi_remove_single_device(host, channel, id, lun);
460 	}
461 
462 	/*
463 	 * convert success returns so that we return the
464 	 * number of bytes consumed.
465 	 */
466 	if (!err)
467 		err = length;
468 
469  out:
470 	free_page((unsigned long)buffer);
471 	return err;
472 }
473 
next_scsi_device(struct device * start)474 static inline struct device *next_scsi_device(struct device *start)
475 {
476 	struct device *next = bus_find_next_device(&scsi_bus_type, start);
477 
478 	put_device(start);
479 	return next;
480 }
481 
scsi_seq_start(struct seq_file * sfile,loff_t * pos)482 static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
483 {
484 	struct device *dev = NULL;
485 	loff_t n = *pos;
486 
487 	while ((dev = next_scsi_device(dev))) {
488 		if (!n--)
489 			break;
490 		sfile->private++;
491 	}
492 	return dev;
493 }
494 
scsi_seq_next(struct seq_file * sfile,void * v,loff_t * pos)495 static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
496 {
497 	(*pos)++;
498 	sfile->private++;
499 	return next_scsi_device(v);
500 }
501 
scsi_seq_stop(struct seq_file * sfile,void * v)502 static void scsi_seq_stop(struct seq_file *sfile, void *v)
503 {
504 	put_device(v);
505 }
506 
scsi_seq_show(struct seq_file * sfile,void * dev)507 static int scsi_seq_show(struct seq_file *sfile, void *dev)
508 {
509 	if (!sfile->private)
510 		seq_puts(sfile, "Attached devices:\n");
511 
512 	return proc_print_scsidevice(dev, sfile);
513 }
514 
515 static const struct seq_operations scsi_seq_ops = {
516 	.start	= scsi_seq_start,
517 	.next	= scsi_seq_next,
518 	.stop	= scsi_seq_stop,
519 	.show	= scsi_seq_show
520 };
521 
522 /**
523  * proc_scsi_open - glue function
524  * @inode: not used
525  * @file: passed to single_open()
526  *
527  * Associates proc_scsi_show with this file
528  */
proc_scsi_open(struct inode * inode,struct file * file)529 static int proc_scsi_open(struct inode *inode, struct file *file)
530 {
531 	/*
532 	 * We don't really need this for the write case but it doesn't
533 	 * harm either.
534 	 */
535 	return seq_open(file, &scsi_seq_ops);
536 }
537 
538 static const struct proc_ops scsi_scsi_proc_ops = {
539 	.proc_open	= proc_scsi_open,
540 	.proc_read	= seq_read,
541 	.proc_write	= proc_scsi_write,
542 	.proc_lseek	= seq_lseek,
543 	.proc_release	= seq_release,
544 };
545 
546 /**
547  * scsi_init_procfs - create scsi and scsi/scsi in procfs
548  */
scsi_init_procfs(void)549 int __init scsi_init_procfs(void)
550 {
551 	struct proc_dir_entry *pde;
552 
553 	proc_scsi = proc_mkdir("scsi", NULL);
554 	if (!proc_scsi)
555 		goto err1;
556 
557 	pde = proc_create("scsi/scsi", 0, NULL, &scsi_scsi_proc_ops);
558 	if (!pde)
559 		goto err2;
560 
561 	return 0;
562 
563 err2:
564 	remove_proc_entry("scsi", NULL);
565 err1:
566 	return -ENOMEM;
567 }
568 
569 /**
570  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
571  */
scsi_exit_procfs(void)572 void scsi_exit_procfs(void)
573 {
574 	remove_proc_entry("scsi/scsi", NULL);
575 	remove_proc_entry("scsi", NULL);
576 }
577