linux/drivers/scsi/scsi_proc.c
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   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/proc_fs.h>
  24#include <linux/errno.h>
  25#include <linux/blkdev.h>
  26#include <linux/seq_file.h>
  27#include <linux/mutex.h>
  28#include <linux/gfp.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
  43static struct proc_dir_entry *proc_scsi;
  44
  45/* Protect sht->present and sht->proc_dir */
  46static 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
  58static 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 */
  77static 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        }
  95out:
  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
 107void 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                               __func__, sht->proc_name);
 118        }
 119        mutex_unlock(&global_host_template_mutex);
 120}
 121
 122/**
 123 * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
 124 * @sht: owner of directory
 125 */
 126void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
 127{
 128        if (!sht->proc_info)
 129                return;
 130
 131        mutex_lock(&global_host_template_mutex);
 132        if (!--sht->present && sht->proc_dir) {
 133                remove_proc_entry(sht->proc_name, proc_scsi);
 134                sht->proc_dir = NULL;
 135        }
 136        mutex_unlock(&global_host_template_mutex);
 137}
 138
 139
 140/**
 141 * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
 142 * @shost: host to add
 143 */
 144void scsi_proc_host_add(struct Scsi_Host *shost)
 145{
 146        struct scsi_host_template *sht = shost->hostt;
 147        struct proc_dir_entry *p;
 148        char name[10];
 149
 150        if (!sht->proc_dir)
 151                return;
 152
 153        sprintf(name,"%d", shost->host_no);
 154        p = create_proc_read_entry(name, S_IFREG | S_IRUGO | S_IWUSR,
 155                        sht->proc_dir, proc_scsi_read, shost);
 156        if (!p) {
 157                printk(KERN_ERR "%s: Failed to register host %d in"
 158                       "%s\n", __func__, shost->host_no,
 159                       sht->proc_name);
 160                return;
 161        } 
 162
 163        p->write_proc = proc_scsi_write_proc;
 164}
 165
 166/**
 167 * scsi_proc_host_rm - remove this host's entry from /proc
 168 * @shost: which host
 169 */
 170void scsi_proc_host_rm(struct Scsi_Host *shost)
 171{
 172        char name[10];
 173
 174        if (!shost->hostt->proc_dir)
 175                return;
 176
 177        sprintf(name,"%d", shost->host_no);
 178        remove_proc_entry(name, shost->hostt->proc_dir);
 179}
 180/**
 181 * proc_print_scsidevice - return data about this host
 182 * @dev: A scsi device
 183 * @data: &struct seq_file to output to.
 184 *
 185 * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
 186 * and revision.
 187 */
 188static int proc_print_scsidevice(struct device *dev, void *data)
 189{
 190        struct scsi_device *sdev;
 191        struct seq_file *s = data;
 192        int i;
 193
 194        if (!scsi_is_sdev_device(dev))
 195                goto out;
 196
 197        sdev = to_scsi_device(dev);
 198        seq_printf(s,
 199                "Host: scsi%d Channel: %02d Id: %02d Lun: %02d\n  Vendor: ",
 200                sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
 201        for (i = 0; i < 8; i++) {
 202                if (sdev->vendor[i] >= 0x20)
 203                        seq_printf(s, "%c", sdev->vendor[i]);
 204                else
 205                        seq_printf(s, " ");
 206        }
 207
 208        seq_printf(s, " Model: ");
 209        for (i = 0; i < 16; i++) {
 210                if (sdev->model[i] >= 0x20)
 211                        seq_printf(s, "%c", sdev->model[i]);
 212                else
 213                        seq_printf(s, " ");
 214        }
 215
 216        seq_printf(s, " Rev: ");
 217        for (i = 0; i < 4; i++) {
 218                if (sdev->rev[i] >= 0x20)
 219                        seq_printf(s, "%c", sdev->rev[i]);
 220                else
 221                        seq_printf(s, " ");
 222        }
 223
 224        seq_printf(s, "\n");
 225
 226        seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
 227        seq_printf(s, "               ANSI  SCSI revision: %02x",
 228                        sdev->scsi_level - (sdev->scsi_level > 1));
 229        if (sdev->scsi_level == 2)
 230                seq_printf(s, " CCS\n");
 231        else
 232                seq_printf(s, "\n");
 233
 234out:
 235        return 0;
 236}
 237
 238/**
 239 * scsi_add_single_device - Respond to user request to probe for/add device
 240 * @host: user-supplied decimal integer
 241 * @channel: user-supplied decimal integer
 242 * @id: user-supplied decimal integer
 243 * @lun: user-supplied decimal integer
 244 *
 245 * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
 246 *
 247 * does scsi_host_lookup() and either user_scan() if that transport
 248 * type supports it, or else scsi_scan_host_selected()
 249 *
 250 * Note: this seems to be aimed exclusively at SCSI parallel busses.
 251 */
 252
 253static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
 254{
 255        struct Scsi_Host *shost;
 256        int error = -ENXIO;
 257
 258        shost = scsi_host_lookup(host);
 259        if (!shost)
 260                return error;
 261
 262        if (shost->transportt->user_scan)
 263                error = shost->transportt->user_scan(shost, channel, id, lun);
 264        else
 265                error = scsi_scan_host_selected(shost, channel, id, lun, 1);
 266        scsi_host_put(shost);
 267        return error;
 268}
 269
 270/**
 271 * scsi_remove_single_device - Respond to user request to remove a device
 272 * @host: user-supplied decimal integer
 273 * @channel: user-supplied decimal integer
 274 * @id: user-supplied decimal integer
 275 * @lun: user-supplied decimal integer
 276 *
 277 * Description: called by writing "scsi remove-single-device" to
 278 * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
 279 */
 280static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
 281{
 282        struct scsi_device *sdev;
 283        struct Scsi_Host *shost;
 284        int error = -ENXIO;
 285
 286        shost = scsi_host_lookup(host);
 287        if (!shost)
 288                return error;
 289        sdev = scsi_device_lookup(shost, channel, id, lun);
 290        if (sdev) {
 291                scsi_remove_device(sdev);
 292                scsi_device_put(sdev);
 293                error = 0;
 294        }
 295
 296        scsi_host_put(shost);
 297        return error;
 298}
 299
 300/**
 301 * proc_scsi_write - handle writes to /proc/scsi/scsi
 302 * @file: not used
 303 * @buf: buffer to write
 304 * @length: length of buf, at most PAGE_SIZE
 305 * @ppos: not used
 306 *
 307 * Description: this provides a legacy mechanism to add or remove devices by
 308 * Host, Channel, ID, and Lun.  To use,
 309 * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
 310 * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
 311 * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
 312 *
 313 * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
 314 * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
 315 * provide a unique identifier and nothing more.
 316 */
 317
 318
 319static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
 320                               size_t length, loff_t *ppos)
 321{
 322        int host, channel, id, lun;
 323        char *buffer, *p;
 324        int err;
 325
 326        if (!buf || length > PAGE_SIZE)
 327                return -EINVAL;
 328
 329        buffer = (char *)__get_free_page(GFP_KERNEL);
 330        if (!buffer)
 331                return -ENOMEM;
 332
 333        err = -EFAULT;
 334        if (copy_from_user(buffer, buf, length))
 335                goto out;
 336
 337        err = -EINVAL;
 338        if (length < PAGE_SIZE)
 339                buffer[length] = '\0';
 340        else if (buffer[PAGE_SIZE-1])
 341                goto out;
 342
 343        /*
 344         * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
 345         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
 346         */
 347        if (!strncmp("scsi add-single-device", buffer, 22)) {
 348                p = buffer + 23;
 349
 350                host = simple_strtoul(p, &p, 0);
 351                channel = simple_strtoul(p + 1, &p, 0);
 352                id = simple_strtoul(p + 1, &p, 0);
 353                lun = simple_strtoul(p + 1, &p, 0);
 354
 355                err = scsi_add_single_device(host, channel, id, lun);
 356
 357        /*
 358         * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
 359         * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
 360         */
 361        } else if (!strncmp("scsi remove-single-device", buffer, 25)) {
 362                p = buffer + 26;
 363
 364                host = simple_strtoul(p, &p, 0);
 365                channel = simple_strtoul(p + 1, &p, 0);
 366                id = simple_strtoul(p + 1, &p, 0);
 367                lun = simple_strtoul(p + 1, &p, 0);
 368
 369                err = scsi_remove_single_device(host, channel, id, lun);
 370        }
 371
 372        /*
 373         * convert success returns so that we return the 
 374         * number of bytes consumed.
 375         */
 376        if (!err)
 377                err = length;
 378
 379 out:
 380        free_page((unsigned long)buffer);
 381        return err;
 382}
 383
 384static int always_match(struct device *dev, void *data)
 385{
 386        return 1;
 387}
 388
 389static inline struct device *next_scsi_device(struct device *start)
 390{
 391        struct device *next = bus_find_device(&scsi_bus_type, start, NULL,
 392                                              always_match);
 393        put_device(start);
 394        return next;
 395}
 396
 397static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
 398{
 399        struct device *dev = NULL;
 400        loff_t n = *pos;
 401
 402        while ((dev = next_scsi_device(dev))) {
 403                if (!n--)
 404                        break;
 405                sfile->private++;
 406        }
 407        return dev;
 408}
 409
 410static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
 411{
 412        (*pos)++;
 413        sfile->private++;
 414        return next_scsi_device(v);
 415}
 416
 417static void scsi_seq_stop(struct seq_file *sfile, void *v)
 418{
 419        put_device(v);
 420}
 421
 422static int scsi_seq_show(struct seq_file *sfile, void *dev)
 423{
 424        if (!sfile->private)
 425                seq_puts(sfile, "Attached devices:\n");
 426
 427        return proc_print_scsidevice(dev, sfile);
 428}
 429
 430static const struct seq_operations scsi_seq_ops = {
 431        .start  = scsi_seq_start,
 432        .next   = scsi_seq_next,
 433        .stop   = scsi_seq_stop,
 434        .show   = scsi_seq_show
 435};
 436
 437/**
 438 * proc_scsi_open - glue function
 439 * @inode: not used
 440 * @file: passed to single_open()
 441 *
 442 * Associates proc_scsi_show with this file
 443 */
 444static int proc_scsi_open(struct inode *inode, struct file *file)
 445{
 446        /*
 447         * We don't really need this for the write case but it doesn't
 448         * harm either.
 449         */
 450        return seq_open(file, &scsi_seq_ops);
 451}
 452
 453static const struct file_operations proc_scsi_operations = {
 454        .owner          = THIS_MODULE,
 455        .open           = proc_scsi_open,
 456        .read           = seq_read,
 457        .write          = proc_scsi_write,
 458        .llseek         = seq_lseek,
 459        .release        = seq_release,
 460};
 461
 462/**
 463 * scsi_init_procfs - create scsi and scsi/scsi in procfs
 464 */
 465int __init scsi_init_procfs(void)
 466{
 467        struct proc_dir_entry *pde;
 468
 469        proc_scsi = proc_mkdir("scsi", NULL);
 470        if (!proc_scsi)
 471                goto err1;
 472
 473        pde = proc_create("scsi/scsi", 0, NULL, &proc_scsi_operations);
 474        if (!pde)
 475                goto err2;
 476
 477        return 0;
 478
 479err2:
 480        remove_proc_entry("scsi", NULL);
 481err1:
 482        return -ENOMEM;
 483}
 484
 485/**
 486 * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
 487 */
 488void scsi_exit_procfs(void)
 489{
 490        remove_proc_entry("scsi/scsi", NULL);
 491        remove_proc_entry("scsi", NULL);
 492}
 493
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