drivers/scsi/scsi_proc.c

   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
  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                                __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  */
 126 void 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  */
 144 void 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  */
 170 void 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  */
 188 static 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
 234 out:
 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
 253 static 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  */
 280 static 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
 319 static 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
 384 static int always_match(struct device *dev, void *data)
 385 {
 386         return 1;
 387 }
 388
 389 static 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
 397 static 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
 410 static 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
 417 static void scsi_seq_stop(struct seq_file *sfile, void *v)
 418 {
 419         put_device(v);
 420 }
 421
 422 static 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
 430 static 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  */
 444 static 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
 453 static 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  */
 465 int __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
 479 err2:
 480         remove_proc_entry("scsi", NULL);
 481 err1:
 482         return -ENOMEM;
 483 }
 484
 485 /**
 486  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
 487  */
 488 void scsi_exit_procfs(void)
 489 {
 490         remove_proc_entry("scsi/scsi", NULL);
 491         remove_proc_entry("scsi", NULL);
 492 }