scsi_proc.c

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/*
 * 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 [email protected] 
 * Version: 0.99.8   last change: 95/09/13
 * 
 * generic command parser provided by: 
 * Andreas Heilwagen <[email protected]>
 *
 * generic_proc_info() support of xxxx_info() by:
 * Michael A. Griffith <[email protected]>
 */

#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 <asm/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 int proc_scsi_read(char *buffer, char **start, off_t offset,
              int length, int *eof, void *data)
{
    struct Scsi_Host *shost = data;
    int n;

    n = shost->hostt->proc_info(shost, buffer, start, offset, length, 0);
    *eof = (n < length);

    return n;
}

static int proc_scsi_write_proc(struct file *file, const char __user *buf,
                           unsigned long count, void *data)
{
    struct Scsi_Host *shost = data;
    ssize_t ret = -ENOMEM;
    char *page;
    char *start;
    
    if (count > PROC_BLOCK_SIZE)
        return -EOVERFLOW;

    page = (char *)__get_free_page(GFP_KERNEL);
    if (page) {
        ret = -EFAULT;
        if (copy_from_user(page, buf, count))
            goto out;
        ret = shost->hostt->proc_info(shost, page, &start, 0, count, 1);
    }
out:
    free_page((unsigned long)page);
    return ret;
}

void scsi_proc_hostdir_add(struct scsi_host_template *sht)
{
    if (!sht->proc_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);
}

void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
{
    if (!sht->proc_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);
}


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 = create_proc_read_entry(name, S_IFREG | S_IRUGO | S_IWUSR,
            sht->proc_dir, proc_scsi_read, shost);
    if (!p) {
        printk(KERN_ERR "%s: Failed to register host %d in"
               "%s\n", __func__, shost->host_no,
               sht->proc_name);
        return;
    } 

    p->write_proc = proc_scsi_write_proc;
}

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);
}
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: %02d\n  Vendor: ",
        sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
    for (i = 0; i < 8; i++) {
        if (sdev->vendor[i] >= 0x20)
            seq_printf(s, "%c", sdev->vendor[i]);
        else
            seq_printf(s, " ");
    }

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

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

    seq_printf(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_printf(s, " CCS\n");
    else
        seq_printf(s, "\n");

out:
    return 0;
}

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, 1);
    scsi_host_put(shost);
    return error;
}

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;
}

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
};

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,
};

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;
}

void scsi_exit_procfs(void)
{
    remove_proc_entry("scsi/scsi", NULL);
    remove_proc_entry("scsi", NULL);
}