xref: /linux/drivers/scsi/scsi_proc.c (revision ed3174d93c342b8b2eeba6bbd124707d55304a7b)
1 /*
2  * linux/drivers/scsi/scsi_proc.c
3  *
4  * The functions in this file provide an interface between
5  * the PROC file system and the SCSI device drivers
6  * It is mainly used for debugging, statistics and to pass
7  * information directly to the lowlevel driver.
8  *
9  * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de
10  * Version: 0.99.8   last change: 95/09/13
11  *
12  * generic command parser provided by:
13  * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
14  *
15  * generic_proc_info() support of xxxx_info() by:
16  * Michael A. Griffith <grif@acm.org>
17  */
18 
19 #include <linux/module.h>
20 #include <linux/init.h>
21 #include <linux/string.h>
22 #include <linux/mm.h>
23 #include <linux/slab.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 <asm/uaccess.h>
30 
31 #include <scsi/scsi.h>
32 #include <scsi/scsi_device.h>
33 #include <scsi/scsi_host.h>
34 #include <scsi/scsi_transport.h>
35 
36 #include "scsi_priv.h"
37 #include "scsi_logging.h"
38 
39 
40 /* 4K page size, but our output routines, use some slack for overruns */
41 #define PROC_BLOCK_SIZE (3*1024)
42 
43 static struct proc_dir_entry *proc_scsi;
44 
45 /* Protect sht->present and sht->proc_dir */
46 static DEFINE_MUTEX(global_host_template_mutex);
47 
48 /**
49  * proc_scsi_read - handle read from /proc by calling host's proc_info() command
50  * @buffer: passed to proc_info
51  * @start: passed to proc_info
52  * @offset: passed to proc_info
53  * @length: passed to proc_info
54  * @eof: returns whether length read was less than requested
55  * @data: pointer to a &struct Scsi_Host
56  */
57 
58 static int proc_scsi_read(char *buffer, char **start, off_t offset,
59 			  int length, int *eof, void *data)
60 {
61 	struct Scsi_Host *shost = data;
62 	int n;
63 
64 	n = shost->hostt->proc_info(shost, buffer, start, offset, length, 0);
65 	*eof = (n < length);
66 
67 	return n;
68 }
69 
70 /**
71  * proc_scsi_write_proc - Handle write to /proc by calling host's proc_info()
72  * @file: not used
73  * @buf: source of data to write.
74  * @count: number of bytes (at most PROC_BLOCK_SIZE) to write.
75  * @data: pointer to &struct Scsi_Host
76  */
77 static int proc_scsi_write_proc(struct file *file, const char __user *buf,
78                            unsigned long count, void *data)
79 {
80 	struct Scsi_Host *shost = data;
81 	ssize_t ret = -ENOMEM;
82 	char *page;
83 	char *start;
84 
85 	if (count > PROC_BLOCK_SIZE)
86 		return -EOVERFLOW;
87 
88 	page = (char *)__get_free_page(GFP_KERNEL);
89 	if (page) {
90 		ret = -EFAULT;
91 		if (copy_from_user(page, buf, count))
92 			goto out;
93 		ret = shost->hostt->proc_info(shost, page, &start, 0, count, 1);
94 	}
95 out:
96 	free_page((unsigned long)page);
97 	return ret;
98 }
99 
100 /**
101  * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
102  * @sht: owner of this directory
103  *
104  * Sets sht->proc_dir to the new directory.
105  */
106 
107 void scsi_proc_hostdir_add(struct scsi_host_template *sht)
108 {
109 	if (!sht->proc_info)
110 		return;
111 
112 	mutex_lock(&global_host_template_mutex);
113 	if (!sht->present++) {
114 		sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
115         	if (!sht->proc_dir)
116 			printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
117 			       __FUNCTION__, sht->proc_name);
118 		else
119 			sht->proc_dir->owner = sht->module;
120 	}
121 	mutex_unlock(&global_host_template_mutex);
122 }
123 
124 /**
125  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
126  * @sht: owner of directory
127  */
128 void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
129 {
130 	if (!sht->proc_info)
131 		return;
132 
133 	mutex_lock(&global_host_template_mutex);
134 	if (!--sht->present && sht->proc_dir) {
135 		remove_proc_entry(sht->proc_name, proc_scsi);
136 		sht->proc_dir = NULL;
137 	}
138 	mutex_unlock(&global_host_template_mutex);
139 }
140 
141 
142 /**
143  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
144  * @shost: host to add
145  */
146 void scsi_proc_host_add(struct Scsi_Host *shost)
147 {
148 	struct scsi_host_template *sht = shost->hostt;
149 	struct proc_dir_entry *p;
150 	char name[10];
151 
152 	if (!sht->proc_dir)
153 		return;
154 
155 	sprintf(name,"%d", shost->host_no);
156 	p = create_proc_read_entry(name, S_IFREG | S_IRUGO | S_IWUSR,
157 			sht->proc_dir, proc_scsi_read, shost);
158 	if (!p) {
159 		printk(KERN_ERR "%s: Failed to register host %d in"
160 		       "%s\n", __FUNCTION__, shost->host_no,
161 		       sht->proc_name);
162 		return;
163 	}
164 
165 	p->write_proc = proc_scsi_write_proc;
166 	p->owner = sht->module;
167 }
168 
169 /**
170  * scsi_proc_host_rm - remove this host's entry from /proc
171  * @shost: which host
172  */
173 void scsi_proc_host_rm(struct Scsi_Host *shost)
174 {
175 	char name[10];
176 
177 	if (!shost->hostt->proc_dir)
178 		return;
179 
180 	sprintf(name,"%d", shost->host_no);
181 	remove_proc_entry(name, shost->hostt->proc_dir);
182 }
183 /**
184  * proc_print_scsidevice - return data about this host
185  * @dev: A scsi device
186  * @data: &struct seq_file to output to.
187  *
188  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
189  * and revision.
190  */
191 static int proc_print_scsidevice(struct device *dev, void *data)
192 {
193 	struct scsi_device *sdev = to_scsi_device(dev);
194 	struct seq_file *s = data;
195 	int i;
196 
197 	seq_printf(s,
198 		"Host: scsi%d Channel: %02d Id: %02d Lun: %02d\n  Vendor: ",
199 		sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
200 	for (i = 0; i < 8; i++) {
201 		if (sdev->vendor[i] >= 0x20)
202 			seq_printf(s, "%c", sdev->vendor[i]);
203 		else
204 			seq_printf(s, " ");
205 	}
206 
207 	seq_printf(s, " Model: ");
208 	for (i = 0; i < 16; i++) {
209 		if (sdev->model[i] >= 0x20)
210 			seq_printf(s, "%c", sdev->model[i]);
211 		else
212 			seq_printf(s, " ");
213 	}
214 
215 	seq_printf(s, " Rev: ");
216 	for (i = 0; i < 4; i++) {
217 		if (sdev->rev[i] >= 0x20)
218 			seq_printf(s, "%c", sdev->rev[i]);
219 		else
220 			seq_printf(s, " ");
221 	}
222 
223 	seq_printf(s, "\n");
224 
225 	seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
226 	seq_printf(s, "               ANSI  SCSI revision: %02x",
227 			sdev->scsi_level - (sdev->scsi_level > 1));
228 	if (sdev->scsi_level == 2)
229 		seq_printf(s, " CCS\n");
230 	else
231 		seq_printf(s, "\n");
232 
233 	return 0;
234 }
235 
236 /**
237  * scsi_add_single_device - Respond to user request to probe for/add device
238  * @host: user-supplied decimal integer
239  * @channel: user-supplied decimal integer
240  * @id: user-supplied decimal integer
241  * @lun: user-supplied decimal integer
242  *
243  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
244  *
245  * does scsi_host_lookup() and either user_scan() if that transport
246  * type supports it, or else scsi_scan_host_selected()
247  *
248  * Note: this seems to be aimed exclusively at SCSI parallel busses.
249  */
250 
251 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
252 {
253 	struct Scsi_Host *shost;
254 	int error = -ENXIO;
255 
256 	shost = scsi_host_lookup(host);
257 	if (IS_ERR(shost))
258 		return PTR_ERR(shost);
259 
260 	if (shost->transportt->user_scan)
261 		error = shost->transportt->user_scan(shost, channel, id, lun);
262 	else
263 		error = scsi_scan_host_selected(shost, channel, id, lun, 1);
264 	scsi_host_put(shost);
265 	return error;
266 }
267 
268 /**
269  * scsi_remove_single_device - Respond to user request to remove a device
270  * @host: user-supplied decimal integer
271  * @channel: user-supplied decimal integer
272  * @id: user-supplied decimal integer
273  * @lun: user-supplied decimal integer
274  *
275  * Description: called by writing "scsi remove-single-device" to
276  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
277  */
278 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
279 {
280 	struct scsi_device *sdev;
281 	struct Scsi_Host *shost;
282 	int error = -ENXIO;
283 
284 	shost = scsi_host_lookup(host);
285 	if (IS_ERR(shost))
286 		return PTR_ERR(shost);
287 	sdev = scsi_device_lookup(shost, channel, id, lun);
288 	if (sdev) {
289 		scsi_remove_device(sdev);
290 		scsi_device_put(sdev);
291 		error = 0;
292 	}
293 
294 	scsi_host_put(shost);
295 	return error;
296 }
297 
298 /**
299  * proc_scsi_write - handle writes to /proc/scsi/scsi
300  * @file: not used
301  * @buf: buffer to write
302  * @length: length of buf, at most PAGE_SIZE
303  * @ppos: not used
304  *
305  * Description: this provides a legacy mechanism to add or remove devices by
306  * Host, Channel, ID, and Lun.  To use,
307  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
308  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
309  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
310  *
311  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
312  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
313  * provide a unique identifier and nothing more.
314  */
315 
316 
317 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
318 			       size_t length, loff_t *ppos)
319 {
320 	int host, channel, id, lun;
321 	char *buffer, *p;
322 	int err;
323 
324 	if (!buf || length > PAGE_SIZE)
325 		return -EINVAL;
326 
327 	buffer = (char *)__get_free_page(GFP_KERNEL);
328 	if (!buffer)
329 		return -ENOMEM;
330 
331 	err = -EFAULT;
332 	if (copy_from_user(buffer, buf, length))
333 		goto out;
334 
335 	err = -EINVAL;
336 	if (length < PAGE_SIZE)
337 		buffer[length] = '\0';
338 	else if (buffer[PAGE_SIZE-1])
339 		goto out;
340 
341 	/*
342 	 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
343 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
344 	 */
345 	if (!strncmp("scsi add-single-device", buffer, 22)) {
346 		p = buffer + 23;
347 
348 		host = simple_strtoul(p, &p, 0);
349 		channel = simple_strtoul(p + 1, &p, 0);
350 		id = simple_strtoul(p + 1, &p, 0);
351 		lun = simple_strtoul(p + 1, &p, 0);
352 
353 		err = scsi_add_single_device(host, channel, id, lun);
354 
355 	/*
356 	 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
357 	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
358 	 */
359 	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
360 		p = buffer + 26;
361 
362 		host = simple_strtoul(p, &p, 0);
363 		channel = simple_strtoul(p + 1, &p, 0);
364 		id = simple_strtoul(p + 1, &p, 0);
365 		lun = simple_strtoul(p + 1, &p, 0);
366 
367 		err = scsi_remove_single_device(host, channel, id, lun);
368 	}
369 
370 	/*
371 	 * convert success returns so that we return the
372 	 * number of bytes consumed.
373 	 */
374 	if (!err)
375 		err = length;
376 
377  out:
378 	free_page((unsigned long)buffer);
379 	return err;
380 }
381 
382 /**
383  * proc_scsi_show - show contents of /proc/scsi/scsi (attached devices)
384  * @s: output goes here
385  * @p: not used
386  */
387 static int proc_scsi_show(struct seq_file *s, void *p)
388 {
389 	seq_printf(s, "Attached devices:\n");
390 	bus_for_each_dev(&scsi_bus_type, NULL, s, proc_print_scsidevice);
391 	return 0;
392 }
393 
394 /**
395  * proc_scsi_open - glue function
396  * @inode: not used
397  * @file: passed to single_open()
398  *
399  * Associates proc_scsi_show with this file
400  */
401 static int proc_scsi_open(struct inode *inode, struct file *file)
402 {
403 	/*
404 	 * We don't really need this for the write case but it doesn't
405 	 * harm either.
406 	 */
407 	return single_open(file, proc_scsi_show, NULL);
408 }
409 
410 static const struct file_operations proc_scsi_operations = {
411 	.open		= proc_scsi_open,
412 	.read		= seq_read,
413 	.write		= proc_scsi_write,
414 	.llseek		= seq_lseek,
415 	.release	= single_release,
416 };
417 
418 /**
419  * scsi_init_procfs - create scsi and scsi/scsi in procfs
420  */
421 int __init scsi_init_procfs(void)
422 {
423 	struct proc_dir_entry *pde;
424 
425 	proc_scsi = proc_mkdir("scsi", NULL);
426 	if (!proc_scsi)
427 		goto err1;
428 
429 	pde = create_proc_entry("scsi/scsi", 0, NULL);
430 	if (!pde)
431 		goto err2;
432 	pde->proc_fops = &proc_scsi_operations;
433 
434 	return 0;
435 
436 err2:
437 	remove_proc_entry("scsi", NULL);
438 err1:
439 	return -ENOMEM;
440 }
441 
442 /**
443  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
444  */
445 void scsi_exit_procfs(void)
446 {
447 	remove_proc_entry("scsi/scsi", NULL);
448 	remove_proc_entry("scsi", NULL);
449 }
450