[mirror_ubuntu-artful-kernel.git] / drivers / scsi / scsi_proc.c

/*
 * linux/drivers/scsi/scsi_proc.c
 *
 * The functions in this file provide an interface between
 * the PROC file system and the SCSI device drivers
 * It is mainly used for debugging, statistics and to pass 
 * information directly to the lowlevel driver.
 *
 * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de 
 * Version: 0.99.8   last change: 95/09/13
 * 
 * generic command parser provided by: 
 * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
 *
 * generic_proc_info() support of xxxx_info() by:
 * Michael A. Griffith <grif@acm.org>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/errno.h>
#include <linux/blkdev.h>
#include <linux/seq_file.h>
#include <linux/mutex.h>
#include <linux/gfp.h>
#include <linux/uaccess.h>

#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_transport.h>

#include "scsi_priv.h"
#include "scsi_logging.h"


/* 4K page size, but our output routines, use some slack for overruns */
#define PROC_BLOCK_SIZE (3*1024)

static struct proc_dir_entry *proc_scsi;

/* Protect sht->present and sht->proc_dir */
static DEFINE_MUTEX(global_host_template_mutex);

static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
                           size_t count, loff_t *ppos)
{
	struct Scsi_Host *shost = PDE_DATA(file_inode(file));
	ssize_t ret = -ENOMEM;
	char *page;
    
	if (count > PROC_BLOCK_SIZE)
		return -EOVERFLOW;

	if (!shost->hostt->write_info)
		return -EINVAL;

	page = (char *)__get_free_page(GFP_KERNEL);
	if (page) {
		ret = -EFAULT;
		if (copy_from_user(page, buf, count))
			goto out;
		ret = shost->hostt->write_info(shost, page, count);
	}
out:
	free_page((unsigned long)page);
	return ret;
}

static int proc_scsi_show(struct seq_file *m, void *v)
{
	struct Scsi_Host *shost = m->private;
	return shost->hostt->show_info(m, shost);
}

static int proc_scsi_host_open(struct inode *inode, struct file *file)
{
	return single_open_size(file, proc_scsi_show, PDE_DATA(inode),
				4 * PAGE_SIZE);
}

static const struct file_operations proc_scsi_fops = {
	.open = proc_scsi_host_open,
	.release = single_release,
	.read = seq_read,
	.llseek = seq_lseek,
	.write = proc_scsi_host_write
};

/**
 * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
 * @sht: owner of this directory
 *
 * Sets sht->proc_dir to the new directory.
 */

void scsi_proc_hostdir_add(struct scsi_host_template *sht)
{
	if (!sht->show_info)
		return;

	mutex_lock(&global_host_template_mutex);
	if (!sht->present++) {
		sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
        	if (!sht->proc_dir)
			printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
			       __func__, sht->proc_name);
	}
	mutex_unlock(&global_host_template_mutex);
}

/**
 * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
 * @sht: owner of directory
 */
void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
{
	if (!sht->show_info)
		return;

	mutex_lock(&global_host_template_mutex);
	if (!--sht->present && sht->proc_dir) {
		remove_proc_entry(sht->proc_name, proc_scsi);
		sht->proc_dir = NULL;
	}
	mutex_unlock(&global_host_template_mutex);
}


/**
 * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
 * @shost: host to add
 */
void scsi_proc_host_add(struct Scsi_Host *shost)
{
	struct scsi_host_template *sht = shost->hostt;
	struct proc_dir_entry *p;
	char name[10];

	if (!sht->proc_dir)
		return;

	sprintf(name,"%d", shost->host_no);
	p = proc_create_data(name, S_IRUGO | S_IWUSR,
		sht->proc_dir, &proc_scsi_fops, shost);
	if (!p)
		printk(KERN_ERR "%s: Failed to register host %d in"
		       "%s\n", __func__, shost->host_no,
		       sht->proc_name);
}

/**
 * scsi_proc_host_rm - remove this host's entry from /proc
 * @shost: which host
 */
void scsi_proc_host_rm(struct Scsi_Host *shost)
{
	char name[10];

	if (!shost->hostt->proc_dir)
		return;

	sprintf(name,"%d", shost->host_no);
	remove_proc_entry(name, shost->hostt->proc_dir);
}
/**
 * proc_print_scsidevice - return data about this host
 * @dev: A scsi device
 * @data: &struct seq_file to output to.
 *
 * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
 * and revision.
 */
static int proc_print_scsidevice(struct device *dev, void *data)
{
	struct scsi_device *sdev;
	struct seq_file *s = data;
	int i;

	if (!scsi_is_sdev_device(dev))
		goto out;

	sdev = to_scsi_device(dev);
	seq_printf(s,
		"Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n  Vendor: ",
		sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
	for (i = 0; i < 8; i++) {
		if (sdev->vendor[i] >= 0x20)
			seq_putc(s, sdev->vendor[i]);
		else
			seq_putc(s, ' ');
	}

	seq_puts(s, " Model: ");
	for (i = 0; i < 16; i++) {
		if (sdev->model[i] >= 0x20)
			seq_putc(s, sdev->model[i]);
		else
			seq_putc(s, ' ');
	}

	seq_puts(s, " Rev: ");
	for (i = 0; i < 4; i++) {
		if (sdev->rev[i] >= 0x20)
			seq_putc(s, sdev->rev[i]);
		else
			seq_putc(s, ' ');
	}

	seq_putc(s, '\n');

	seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
	seq_printf(s, "               ANSI  SCSI revision: %02x",
			sdev->scsi_level - (sdev->scsi_level > 1));
	if (sdev->scsi_level == 2)
		seq_puts(s, " CCS\n");
	else
		seq_putc(s, '\n');

out:
	return 0;
}

/**
 * scsi_add_single_device - Respond to user request to probe for/add device
 * @host: user-supplied decimal integer
 * @channel: user-supplied decimal integer
 * @id: user-supplied decimal integer
 * @lun: user-supplied decimal integer
 *
 * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
 *
 * does scsi_host_lookup() and either user_scan() if that transport
 * type supports it, or else scsi_scan_host_selected()
 *
 * Note: this seems to be aimed exclusively at SCSI parallel busses.
 */

static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
{
	struct Scsi_Host *shost;
	int error = -ENXIO;

	shost = scsi_host_lookup(host);
	if (!shost)
		return error;

	if (shost->transportt->user_scan)
		error = shost->transportt->user_scan(shost, channel, id, lun);
	else
		error = scsi_scan_host_selected(shost, channel, id, lun,
						SCSI_SCAN_MANUAL);
	scsi_host_put(shost);
	return error;
}

/**
 * scsi_remove_single_device - Respond to user request to remove a device
 * @host: user-supplied decimal integer
 * @channel: user-supplied decimal integer
 * @id: user-supplied decimal integer
 * @lun: user-supplied decimal integer
 *
 * Description: called by writing "scsi remove-single-device" to
 * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
 */
static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
{
	struct scsi_device *sdev;
	struct Scsi_Host *shost;
	int error = -ENXIO;

	shost = scsi_host_lookup(host);
	if (!shost)
		return error;
	sdev = scsi_device_lookup(shost, channel, id, lun);
	if (sdev) {
		scsi_remove_device(sdev);
		scsi_device_put(sdev);
		error = 0;
	}

	scsi_host_put(shost);
	return error;
}

/**
 * proc_scsi_write - handle writes to /proc/scsi/scsi
 * @file: not used
 * @buf: buffer to write
 * @length: length of buf, at most PAGE_SIZE
 * @ppos: not used
 *
 * Description: this provides a legacy mechanism to add or remove devices by
 * Host, Channel, ID, and Lun.  To use,
 * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
 * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
 * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
 *
 * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
 * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
 * provide a unique identifier and nothing more.
 */


static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
			       size_t length, loff_t *ppos)
{
	int host, channel, id, lun;
	char *buffer, *p;
	int err;

	if (!buf || length > PAGE_SIZE)
		return -EINVAL;

	buffer = (char *)__get_free_page(GFP_KERNEL);
	if (!buffer)
		return -ENOMEM;

	err = -EFAULT;
	if (copy_from_user(buffer, buf, length))
		goto out;

	err = -EINVAL;
	if (length < PAGE_SIZE)
		buffer[length] = '\0';
	else if (buffer[PAGE_SIZE-1])
		goto out;

	/*
	 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
	 */
	if (!strncmp("scsi add-single-device", buffer, 22)) {
		p = buffer + 23;

		host = simple_strtoul(p, &p, 0);
		channel = simple_strtoul(p + 1, &p, 0);
		id = simple_strtoul(p + 1, &p, 0);
		lun = simple_strtoul(p + 1, &p, 0);

		err = scsi_add_single_device(host, channel, id, lun);

	/*
	 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
	 * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
	 */
	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
		p = buffer + 26;

		host = simple_strtoul(p, &p, 0);
		channel = simple_strtoul(p + 1, &p, 0);
		id = simple_strtoul(p + 1, &p, 0);
		lun = simple_strtoul(p + 1, &p, 0);

		err = scsi_remove_single_device(host, channel, id, lun);
	}

	/*
	 * convert success returns so that we return the 
	 * number of bytes consumed.
	 */
	if (!err)
		err = length;

 out:
	free_page((unsigned long)buffer);
	return err;
}

static int always_match(struct device *dev, void *data)
{
	return 1;
}

static inline struct device *next_scsi_device(struct device *start)
{
	struct device *next = bus_find_device(&scsi_bus_type, start, NULL,
					      always_match);
	put_device(start);
	return next;
}

static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
{
	struct device *dev = NULL;
	loff_t n = *pos;

	while ((dev = next_scsi_device(dev))) {
		if (!n--)
			break;
		sfile->private++;
	}
	return dev;
}

static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
{
	(*pos)++;
	sfile->private++;
	return next_scsi_device(v);
}

static void scsi_seq_stop(struct seq_file *sfile, void *v)
{
	put_device(v);
}

static int scsi_seq_show(struct seq_file *sfile, void *dev)
{
	if (!sfile->private)
		seq_puts(sfile, "Attached devices:\n");

	return proc_print_scsidevice(dev, sfile);
}

static const struct seq_operations scsi_seq_ops = {
	.start	= scsi_seq_start,
	.next	= scsi_seq_next,
	.stop	= scsi_seq_stop,
	.show	= scsi_seq_show
};

/**
 * proc_scsi_open - glue function
 * @inode: not used
 * @file: passed to single_open()
 *
 * Associates proc_scsi_show with this file
 */
static int proc_scsi_open(struct inode *inode, struct file *file)
{
	/*
	 * We don't really need this for the write case but it doesn't
	 * harm either.
	 */
	return seq_open(file, &scsi_seq_ops);
}

static const struct file_operations proc_scsi_operations = {
	.owner		= THIS_MODULE,
	.open		= proc_scsi_open,
	.read		= seq_read,
	.write		= proc_scsi_write,
	.llseek		= seq_lseek,
	.release	= seq_release,
};

/**
 * scsi_init_procfs - create scsi and scsi/scsi in procfs
 */
int __init scsi_init_procfs(void)
{
	struct proc_dir_entry *pde;

	proc_scsi = proc_mkdir("scsi", NULL);
	if (!proc_scsi)
		goto err1;

	pde = proc_create("scsi/scsi", 0, NULL, &proc_scsi_operations);
	if (!pde)
		goto err2;

	return 0;

err2:
	remove_proc_entry("scsi", NULL);
err1:
	return -ENOMEM;
}

/**
 * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
 */
void scsi_exit_procfs(void)
{
	remove_proc_entry("scsi/scsi", NULL);
	remove_proc_entry("scsi", NULL);
}
Commit	Line	Data
1da177e4 LT	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>
1da177e4 LT	23	#include <linux/proc_fs.h>
	24	#include <linux/errno.h>
	25	#include <linux/blkdev.h>
	26	#include <linux/seq_file.h>
0b950672	27	#include <linux/mutex.h>
5a0e3ad6	28	#include <linux/gfp.h>
7c0f6ba6	29	#include <linux/uaccess.h>
1da177e4 LT	30
	31	#include <scsi/scsi.h>
	32	#include <scsi/scsi_device.h>
	33	#include <scsi/scsi_host.h>
e02f3f59	34	#include <scsi/scsi_transport.h>
1da177e4 LT	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 */
0b950672	46	static DEFINE_MUTEX(global_host_template_mutex);
1da177e4	47
0ffddfbb AV	48	static ssize_t proc_scsi_host_write(struct file file, const char __user buf,
	49	size_t count, loff_t *ppos)
	50	{
d9dda78b	51	struct Scsi_Host *shost = PDE_DATA(file_inode(file));
0ffddfbb AV	52	ssize_t ret = -ENOMEM;
	53	char *page;
	54
	55	if (count > PROC_BLOCK_SIZE)
	56	return -EOVERFLOW;
	57
	58	if (!shost->hostt->write_info)
	59	return -EINVAL;
	60
	61	page = (char *)__get_free_page(GFP_KERNEL);
	62	if (page) {
	63	ret = -EFAULT;
	64	if (copy_from_user(page, buf, count))
	65	goto out;
	66	ret = shost->hostt->write_info(shost, page, count);
	67	}
	68	out:
	69	free_page((unsigned long)page);
	70	return ret;
	71	}
	72
	73	static int proc_scsi_show(struct seq_file m, void v)
	74	{
	75	struct Scsi_Host *shost = m->private;
	76	return shost->hostt->show_info(m, shost);
	77	}
	78
	79	static int proc_scsi_host_open(struct inode inode, struct file file)
	80	{
d9dda78b	81	return single_open_size(file, proc_scsi_show, PDE_DATA(inode),
859d22f9	82	4 * PAGE_SIZE);
0ffddfbb AV	83	}
	84
	85	static const struct file_operations proc_scsi_fops = {
	86	.open = proc_scsi_host_open,
801d9d26	87	.release = single_release,
0ffddfbb AV	88	.read = seq_read,
	89	.llseek = seq_lseek,
	90	.write = proc_scsi_host_write
	91	};
	92
eb44820c RL	93	/**
	94	* scsi_proc_hostdir_add - Create directory in /proc for a scsi host
	95	* @sht: owner of this directory
	96	*
	97	* Sets sht->proc_dir to the new directory.
	98	*/
	99
1da177e4 LT	100	void scsi_proc_hostdir_add(struct scsi_host_template *sht)
1da177e4 LT	101	{
70ef457d	102	if (!sht->show_info)
1da177e4 LT	103	return;
1da177e4 LT	104
0b950672	105	mutex_lock(&global_host_template_mutex);
1da177e4 LT	106	if (!sht->present++) {
	107	sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
	108	if (!sht->proc_dir)
	109	printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
cadbd4a5	110	__func__, sht->proc_name);
1da177e4	111	}
0b950672	112	mutex_unlock(&global_host_template_mutex);
1da177e4 LT	113	}
1da177e4 LT	114
eb44820c RL	115	/**
	116	* scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
	117	* @sht: owner of directory
	118	*/
1da177e4 LT	119	void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
1da177e4 LT	120	{
70ef457d	121	if (!sht->show_info)
1da177e4 LT	122	return;
1da177e4 LT	123
0b950672	124	mutex_lock(&global_host_template_mutex);
1da177e4 LT	125	if (!--sht->present && sht->proc_dir) {
	126	remove_proc_entry(sht->proc_name, proc_scsi);
	127	sht->proc_dir = NULL;
	128	}
0b950672	129	mutex_unlock(&global_host_template_mutex);
1da177e4 LT	130	}
1da177e4 LT	131
eb44820c RL	132
	133	/**
	134	* scsi_proc_host_add - Add entry for this host to appropriate /proc dir
	135	* @shost: host to add
	136	*/
1da177e4 LT	137	void scsi_proc_host_add(struct Scsi_Host *shost)
	138	{
	139	struct scsi_host_template *sht = shost->hostt;
	140	struct proc_dir_entry *p;
	141	char name[10];
	142
	143	if (!sht->proc_dir)
	144	return;
	145
	146	sprintf(name,"%d", shost->host_no);
70ef457d AV	147	p = proc_create_data(name, S_IRUGO \| S_IWUSR,
	148	sht->proc_dir, &proc_scsi_fops, shost);
	149	if (!p)
	150	printk(KERN_ERR "%s: Failed to register host %d in"
	151	"%s\n", __func__, shost->host_no,
	152	sht->proc_name);
1da177e4 LT	153	}
1da177e4 LT	154
eb44820c RL	155	/**
	156	* scsi_proc_host_rm - remove this host's entry from /proc
	157	* @shost: which host
	158	*/
1da177e4 LT	159	void scsi_proc_host_rm(struct Scsi_Host *shost)
	160	{
	161	char name[10];
	162
	163	if (!shost->hostt->proc_dir)
	164	return;
	165
	166	sprintf(name,"%d", shost->host_no);
	167	remove_proc_entry(name, shost->hostt->proc_dir);
	168	}
eb44820c RL	169	/**
	170	* proc_print_scsidevice - return data about this host
	171	* @dev: A scsi device
	172	* @data: &struct seq_file to output to.
	173	*
	174	* Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
	175	* and revision.
	176	*/
1da177e4 LT	177	static int proc_print_scsidevice(struct device dev, void data)
1da177e4 LT	178	{
b0ed4336	179	struct scsi_device *sdev;
1da177e4 LT	180	struct seq_file *s = data;
	181	int i;
	182
b0ed4336 HR	183	if (!scsi_is_sdev_device(dev))
	184	goto out;
	185
	186	sdev = to_scsi_device(dev);
1da177e4	187	seq_printf(s,
9cb78c16	188	"Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n Vendor: ",
1da177e4 LT	189	sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
	190	for (i = 0; i < 8; i++) {
	191	if (sdev->vendor[i] >= 0x20)
91c40f24	192	seq_putc(s, sdev->vendor[i]);
1da177e4	193	else
f50332ff	194	seq_putc(s, ' ');
1da177e4 LT	195	}
1da177e4 LT	196
91c40f24	197	seq_puts(s, " Model: ");
1da177e4 LT	198	for (i = 0; i < 16; i++) {
1da177e4 LT	199	if (sdev->model[i] >= 0x20)
91c40f24	200	seq_putc(s, sdev->model[i]);
1da177e4	201	else
f50332ff	202	seq_putc(s, ' ');
1da177e4 LT	203	}
1da177e4 LT	204
91c40f24	205	seq_puts(s, " Rev: ");
1da177e4 LT	206	for (i = 0; i < 4; i++) {
1da177e4 LT	207	if (sdev->rev[i] >= 0x20)
91c40f24	208	seq_putc(s, sdev->rev[i]);
1da177e4	209	else
f50332ff	210	seq_putc(s, ' ');
1da177e4 LT	211	}
1da177e4 LT	212
f50332ff	213	seq_putc(s, '\n');
1da177e4	214
4ff36718	215	seq_printf(s, " Type: %s ", scsi_device_type(sdev->type));
74feb53e AS	216	seq_printf(s, " ANSI SCSI revision: %02x",
74feb53e AS	217	sdev->scsi_level - (sdev->scsi_level > 1));
1da177e4	218	if (sdev->scsi_level == 2)
91c40f24	219	seq_puts(s, " CCS\n");
1da177e4	220	else
f50332ff	221	seq_putc(s, '\n');
1da177e4	222
b0ed4336	223	out:
1da177e4 LT	224	return 0;
	225	}
	226
eb44820c RL	227	/**
	228	* scsi_add_single_device - Respond to user request to probe for/add device
	229	* @host: user-supplied decimal integer
	230	* @channel: user-supplied decimal integer
	231	* @id: user-supplied decimal integer
	232	* @lun: user-supplied decimal integer
	233	*
	234	* Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
	235	*
	236	* does scsi_host_lookup() and either user_scan() if that transport
	237	* type supports it, or else scsi_scan_host_selected()
	238	*
	239	* Note: this seems to be aimed exclusively at SCSI parallel busses.
	240	*/
	241
1da177e4 LT	242	static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
	243	{
	244	struct Scsi_Host *shost;
	245	int error = -ENXIO;
	246
	247	shost = scsi_host_lookup(host);
315cb0ad JS	248	if (!shost)
315cb0ad JS	249	return error;
1da177e4	250
e02f3f59 CH	251	if (shost->transportt->user_scan)
	252	error = shost->transportt->user_scan(shost, channel, id, lun);
	253	else
1d645088 HR	254	error = scsi_scan_host_selected(shost, channel, id, lun,
1d645088 HR	255	SCSI_SCAN_MANUAL);
1da177e4 LT	256	scsi_host_put(shost);
	257	return error;
	258	}
	259
eb44820c RL	260	/**
	261	* scsi_remove_single_device - Respond to user request to remove a device
	262	* @host: user-supplied decimal integer
	263	* @channel: user-supplied decimal integer
	264	* @id: user-supplied decimal integer
	265	* @lun: user-supplied decimal integer
	266	*
	267	* Description: called by writing "scsi remove-single-device" to
	268	* /proc/scsi/scsi. Does a scsi_device_lookup() and scsi_remove_device()
	269	*/
1da177e4 LT	270	static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
	271	{
	272	struct scsi_device *sdev;
	273	struct Scsi_Host *shost;
	274	int error = -ENXIO;
	275
	276	shost = scsi_host_lookup(host);
315cb0ad JS	277	if (!shost)
315cb0ad JS	278	return error;
1da177e4 LT	279	sdev = scsi_device_lookup(shost, channel, id, lun);
	280	if (sdev) {
	281	scsi_remove_device(sdev);
	282	scsi_device_put(sdev);
	283	error = 0;
	284	}
	285
	286	scsi_host_put(shost);
	287	return error;
	288	}
	289
eb44820c RL	290	/**
	291	* proc_scsi_write - handle writes to /proc/scsi/scsi
	292	* @file: not used
	293	* @buf: buffer to write
	294	* @length: length of buf, at most PAGE_SIZE
	295	* @ppos: not used
	296	*
	297	* Description: this provides a legacy mechanism to add or remove devices by
	298	* Host, Channel, ID, and Lun. To use,
	299	* "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
	300	* "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
	301	* "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
	302	*
	303	* Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
	304	* SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
	305	* provide a unique identifier and nothing more.
	306	*/
	307
	308
1da177e4 LT	309	static ssize_t proc_scsi_write(struct file file, const char __user buf,
	310	size_t length, loff_t *ppos)
	311	{
	312	int host, channel, id, lun;
	313	char buffer, p;
	314	int err;
	315
	316	if (!buf \|\| length > PAGE_SIZE)
	317	return -EINVAL;
	318
	319	buffer = (char *)__get_free_page(GFP_KERNEL);
	320	if (!buffer)
	321	return -ENOMEM;
	322
	323	err = -EFAULT;
	324	if (copy_from_user(buffer, buf, length))
	325	goto out;
	326
	327	err = -EINVAL;
	328	if (length < PAGE_SIZE)
	329	buffer[length] = '\0';
	330	else if (buffer[PAGE_SIZE-1])
	331	goto out;
	332
	333	/*
	334	* Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
	335	* with "0 1 2 3" replaced by your "Host Channel Id Lun".
	336	*/
	337	if (!strncmp("scsi add-single-device", buffer, 22)) {
	338	p = buffer + 23;
	339
	340	host = simple_strtoul(p, &p, 0);
	341	channel = simple_strtoul(p + 1, &p, 0);
	342	id = simple_strtoul(p + 1, &p, 0);
	343	lun = simple_strtoul(p + 1, &p, 0);
	344
	345	err = scsi_add_single_device(host, channel, id, lun);
1da177e4 LT	346
	347	/*
	348	* Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
	349	* with "0 1 2 3" replaced by your "Host Channel Id Lun".
	350	*/
	351	} else if (!strncmp("scsi remove-single-device", buffer, 25)) {
	352	p = buffer + 26;
	353
	354	host = simple_strtoul(p, &p, 0);
	355	channel = simple_strtoul(p + 1, &p, 0);
	356	id = simple_strtoul(p + 1, &p, 0);
	357	lun = simple_strtoul(p + 1, &p, 0);
	358
	359	err = scsi_remove_single_device(host, channel, id, lun);
	360	}
	361
2ca48a13 JB	362	/*
	363	* convert success returns so that we return the
	364	* number of bytes consumed.
	365	*/
	366	if (!err)
	367	err = length;
	368
1da177e4 LT	369	out:
	370	free_page((unsigned long)buffer);
	371	return err;
	372	}
	373
e37c4913	374	static int always_match(struct device dev, void data)
1da177e4	375	{
e37c4913 JM	376	return 1;
	377	}
	378
	379	static inline struct device next_scsi_device(struct device start)
	380	{
	381	struct device *next = bus_find_device(&scsi_bus_type, start, NULL,
	382	always_match);
	383	put_device(start);
	384	return next;
1da177e4 LT	385	}
1da177e4 LT	386
e37c4913 JM	387	static void scsi_seq_start(struct seq_file sfile, loff_t *pos)
	388	{
	389	struct device *dev = NULL;
	390	loff_t n = *pos;
	391
	392	while ((dev = next_scsi_device(dev))) {
	393	if (!n--)
	394	break;
	395	sfile->private++;
	396	}
	397	return dev;
	398	}
	399
	400	static void scsi_seq_next(struct seq_file sfile, void v, loff_t pos)
	401	{
	402	(*pos)++;
	403	sfile->private++;
	404	return next_scsi_device(v);
	405	}
	406
	407	static void scsi_seq_stop(struct seq_file sfile, void v)
	408	{
	409	put_device(v);
	410	}
	411
	412	static int scsi_seq_show(struct seq_file sfile, void dev)
	413	{
	414	if (!sfile->private)
	415	seq_puts(sfile, "Attached devices:\n");
	416
	417	return proc_print_scsidevice(dev, sfile);
	418	}
	419
	420	static const struct seq_operations scsi_seq_ops = {
	421	.start = scsi_seq_start,
	422	.next = scsi_seq_next,
	423	.stop = scsi_seq_stop,
	424	.show = scsi_seq_show
	425	};
	426
eb44820c RL	427	/**
	428	* proc_scsi_open - glue function
	429	* @inode: not used
	430	* @file: passed to single_open()
	431	*
	432	* Associates proc_scsi_show with this file
	433	*/
1da177e4 LT	434	static int proc_scsi_open(struct inode inode, struct file file)
	435	{
	436	/*
eb44820c	437	* We don't really need this for the write case but it doesn't
1da177e4 LT	438	* harm either.
1da177e4 LT	439	*/
e37c4913	440	return seq_open(file, &scsi_seq_ops);
1da177e4 LT	441	}
1da177e4 LT	442
00977a59	443	static const struct file_operations proc_scsi_operations = {
a973909f	444	.owner = THIS_MODULE,
1da177e4 LT	445	.open = proc_scsi_open,
	446	.read = seq_read,
	447	.write = proc_scsi_write,
	448	.llseek = seq_lseek,
e37c4913	449	.release = seq_release,
1da177e4 LT	450	};
1da177e4 LT	451
eb44820c RL	452	/**
	453	* scsi_init_procfs - create scsi and scsi/scsi in procfs
	454	*/
1da177e4 LT	455	int __init scsi_init_procfs(void)
	456	{
	457	struct proc_dir_entry *pde;
	458
	459	proc_scsi = proc_mkdir("scsi", NULL);
	460	if (!proc_scsi)
	461	goto err1;
	462
a973909f	463	pde = proc_create("scsi/scsi", 0, NULL, &proc_scsi_operations);
1da177e4 LT	464	if (!pde)
1da177e4 LT	465	goto err2;
1da177e4 LT	466
	467	return 0;
	468
	469	err2:
	470	remove_proc_entry("scsi", NULL);
	471	err1:
	472	return -ENOMEM;
	473	}
	474
eb44820c RL	475	/**
	476	* scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
	477	*/
1da177e4 LT	478	void scsi_exit_procfs(void)
	479	{
	480	remove_proc_entry("scsi/scsi", NULL);
	481	remove_proc_entry("scsi", NULL);
	482	}