drivers/scsi/scsi_proc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/drivers/scsi/scsi_proc.c
   4  *
   5  * The functions in this file provide an interface between
   6  * the PROC file system and the SCSI device drivers
   7  * It is mainly used for debugging, statistics and to pass
   8  * information directly to the lowlevel driver.
   9  *
  10  * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de
  11  * Version: 0.99.8   last change: 95/09/13
  12  *
  13  * generic command parser provided by:
  14  * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
  15  *
  16  * generic_proc_info() support of xxxx_info() by:
  17  * Michael A. Griffith <grif@acm.org>
  18  */
  19
  20 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/string.h>
  23 #include <linux/mm.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 <linux/gfp.h>
  30 #include <linux/uaccess.h>
  31
  32 #include <scsi/scsi.h>
  33 #include <scsi/scsi_device.h>
  34 #include <scsi/scsi_host.h>
  35 #include <scsi/scsi_transport.h>
  36
  37 #include "scsi_priv.h"
  38 #include "scsi_logging.h"
  39
  40
  41 /* 4K page size, but our output routines, use some slack for overruns */
  42 #define PROC_BLOCK_SIZE (3*1024)
  43
  44 static struct proc_dir_entry *proc_scsi;
  45
  46 /* Protects scsi_proc_list */
  47 static DEFINE_MUTEX(global_host_template_mutex);
  48 static LIST_HEAD(scsi_proc_list);
  49
  50 /**
  51  * struct scsi_proc_entry - (host template, SCSI proc dir) association
  52  * @entry: entry in scsi_proc_list.
  53  * @sht: SCSI host template associated with the procfs directory.
  54  * @proc_dir: procfs directory associated with the SCSI host template.
  55  * @present: Number of SCSI hosts instantiated for @sht.
  56  */
  57 struct scsi_proc_entry {
  58         struct list_head        entry;
  59         const struct scsi_host_template *sht;
  60         struct proc_dir_entry   *proc_dir;
  61         unsigned int            present;
  62 };
  63
  64 static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
  65                            size_t count, loff_t *ppos)
  66 {
  67         struct Scsi_Host *shost = pde_data(file_inode(file));
  68         ssize_t ret = -ENOMEM;
  69         char *page;
  70
  71         if (count > PROC_BLOCK_SIZE)
  72                 return -EOVERFLOW;
  73
  74         if (!shost->hostt->write_info)
  75                 return -EINVAL;
  76
  77         page = (char *)__get_free_page(GFP_KERNEL);
  78         if (page) {
  79                 ret = -EFAULT;
  80                 if (copy_from_user(page, buf, count))
  81                         goto out;
  82                 ret = shost->hostt->write_info(shost, page, count);
  83         }
  84 out:
  85         free_page((unsigned long)page);
  86         return ret;
  87 }
  88
  89 static int proc_scsi_show(struct seq_file *m, void *v)
  90 {
  91         struct Scsi_Host *shost = m->private;
  92         return shost->hostt->show_info(m, shost);
  93 }
  94
  95 static int proc_scsi_host_open(struct inode *inode, struct file *file)
  96 {
  97         return single_open_size(file, proc_scsi_show, pde_data(inode),
  98                                 4 * PAGE_SIZE);
  99 }
 100
 101 static struct scsi_proc_entry *
 102 __scsi_lookup_proc_entry(const struct scsi_host_template *sht)
 103 {
 104         struct scsi_proc_entry *e;
 105
 106         lockdep_assert_held(&global_host_template_mutex);
 107
 108         list_for_each_entry(e, &scsi_proc_list, entry)
 109                 if (e->sht == sht)
 110                         return e;
 111
 112         return NULL;
 113 }
 114
 115 static struct scsi_proc_entry *
 116 scsi_lookup_proc_entry(const struct scsi_host_template *sht)
 117 {
 118         struct scsi_proc_entry *e;
 119
 120         mutex_lock(&global_host_template_mutex);
 121         e = __scsi_lookup_proc_entry(sht);
 122         mutex_unlock(&global_host_template_mutex);
 123
 124         return e;
 125 }
 126
 127 /**
 128  * scsi_template_proc_dir() - returns the procfs dir for a SCSI host template
 129  * @sht: SCSI host template pointer.
 130  */
 131 struct proc_dir_entry *
 132 scsi_template_proc_dir(const struct scsi_host_template *sht)
 133 {
 134         struct scsi_proc_entry *e = scsi_lookup_proc_entry(sht);
 135
 136         return e ? e->proc_dir : NULL;
 137 }
 138 EXPORT_SYMBOL_GPL(scsi_template_proc_dir);
 139
 140 static const struct proc_ops proc_scsi_ops = {
 141         .proc_open      = proc_scsi_host_open,
 142         .proc_release   = single_release,
 143         .proc_read      = seq_read,
 144         .proc_lseek     = seq_lseek,
 145         .proc_write     = proc_scsi_host_write
 146 };
 147
 148 /**
 149  * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
 150  * @sht: owner of this directory
 151  *
 152  * Sets sht->proc_dir to the new directory.
 153  */
 154 int scsi_proc_hostdir_add(const struct scsi_host_template *sht)
 155 {
 156         struct scsi_proc_entry *e;
 157         int ret;
 158
 159         if (!sht->show_info)
 160                 return 0;
 161
 162         mutex_lock(&global_host_template_mutex);
 163         e = __scsi_lookup_proc_entry(sht);
 164         if (!e) {
 165                 e = kzalloc(sizeof(*e), GFP_KERNEL);
 166                 if (!e) {
 167                         ret = -ENOMEM;
 168                         goto unlock;
 169                 }
 170         }
 171         if (e->present++)
 172                 goto success;
 173         e->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
 174         if (!e->proc_dir) {
 175                 printk(KERN_ERR "%s: proc_mkdir failed for %s\n", __func__,
 176                        sht->proc_name);
 177                 ret = -ENOMEM;
 178                 goto unlock;
 179         }
 180         e->sht = sht;
 181         list_add_tail(&e->entry, &scsi_proc_list);
 182 success:
 183         e = NULL;
 184         ret = 0;
 185 unlock:
 186         mutex_unlock(&global_host_template_mutex);
 187
 188         kfree(e);
 189         return ret;
 190 }
 191
 192 /**
 193  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
 194  * @sht: owner of directory
 195  */
 196 void scsi_proc_hostdir_rm(const struct scsi_host_template *sht)
 197 {
 198         struct scsi_proc_entry *e;
 199
 200         if (!sht->show_info)
 201                 return;
 202
 203         mutex_lock(&global_host_template_mutex);
 204         e = __scsi_lookup_proc_entry(sht);
 205         if (e && !--e->present) {
 206                 remove_proc_entry(sht->proc_name, proc_scsi);
 207                 list_del(&e->entry);
 208                 kfree(e);
 209         }
 210         mutex_unlock(&global_host_template_mutex);
 211 }
 212
 213
 214 /**
 215  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
 216  * @shost: host to add
 217  */
 218 void scsi_proc_host_add(struct Scsi_Host *shost)
 219 {
 220         const struct scsi_host_template *sht = shost->hostt;
 221         struct scsi_proc_entry *e;
 222         struct proc_dir_entry *p;
 223         char name[10];
 224
 225         if (!sht->show_info)
 226                 return;
 227
 228         e = scsi_lookup_proc_entry(sht);
 229         if (!e)
 230                 goto err;
 231
 232         sprintf(name,"%d", shost->host_no);
 233         p = proc_create_data(name, S_IRUGO | S_IWUSR, e->proc_dir,
 234                              &proc_scsi_ops, shost);
 235         if (!p)
 236                 goto err;
 237         return;
 238
 239 err:
 240         shost_printk(KERN_ERR, shost,
 241                      "%s: Failed to register host (%s failed)\n", __func__,
 242                      e ? "proc_create_data()" : "scsi_proc_hostdir_add()");
 243 }
 244
 245 /**
 246  * scsi_proc_host_rm - remove this host's entry from /proc
 247  * @shost: which host
 248  */
 249 void scsi_proc_host_rm(struct Scsi_Host *shost)
 250 {
 251         const struct scsi_host_template *sht = shost->hostt;
 252         struct scsi_proc_entry *e;
 253         char name[10];
 254
 255         if (!sht->show_info)
 256                 return;
 257
 258         e = scsi_lookup_proc_entry(sht);
 259         if (!e)
 260                 return;
 261
 262         sprintf(name,"%d", shost->host_no);
 263         remove_proc_entry(name, e->proc_dir);
 264 }
 265 /**
 266  * proc_print_scsidevice - return data about this host
 267  * @dev: A scsi device
 268  * @data: &struct seq_file to output to.
 269  *
 270  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
 271  * and revision.
 272  */
 273 static int proc_print_scsidevice(struct device *dev, void *data)
 274 {
 275         struct scsi_device *sdev;
 276         struct seq_file *s = data;
 277         int i;
 278
 279         if (!scsi_is_sdev_device(dev))
 280                 goto out;
 281
 282         sdev = to_scsi_device(dev);
 283         seq_printf(s,
 284                 "Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n  Vendor: ",
 285                 sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
 286         for (i = 0; i < 8; i++) {
 287                 if (sdev->vendor[i] >= 0x20)
 288                         seq_putc(s, sdev->vendor[i]);
 289                 else
 290                         seq_putc(s, ' ');
 291         }
 292
 293         seq_puts(s, " Model: ");
 294         for (i = 0; i < 16; i++) {
 295                 if (sdev->model[i] >= 0x20)
 296                         seq_putc(s, sdev->model[i]);
 297                 else
 298                         seq_putc(s, ' ');
 299         }
 300
 301         seq_puts(s, " Rev: ");
 302         for (i = 0; i < 4; i++) {
 303                 if (sdev->rev[i] >= 0x20)
 304                         seq_putc(s, sdev->rev[i]);
 305                 else
 306                         seq_putc(s, ' ');
 307         }
 308
 309         seq_putc(s, '\n');
 310
 311         seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
 312         seq_printf(s, "               ANSI  SCSI revision: %02x",
 313                         sdev->scsi_level - (sdev->scsi_level > 1));
 314         if (sdev->scsi_level == 2)
 315                 seq_puts(s, " CCS\n");
 316         else
 317                 seq_putc(s, '\n');
 318
 319 out:
 320         return 0;
 321 }
 322
 323 /**
 324  * scsi_add_single_device - Respond to user request to probe for/add device
 325  * @host: user-supplied decimal integer
 326  * @channel: user-supplied decimal integer
 327  * @id: user-supplied decimal integer
 328  * @lun: user-supplied decimal integer
 329  *
 330  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
 331  *
 332  * does scsi_host_lookup() and either user_scan() if that transport
 333  * type supports it, or else scsi_scan_host_selected()
 334  *
 335  * Note: this seems to be aimed exclusively at SCSI parallel busses.
 336  */
 337
 338 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
 339 {
 340         struct Scsi_Host *shost;
 341         int error = -ENXIO;
 342
 343         shost = scsi_host_lookup(host);
 344         if (!shost)
 345                 return error;
 346
 347         if (shost->transportt->user_scan)
 348                 error = shost->transportt->user_scan(shost, channel, id, lun);
 349         else
 350                 error = scsi_scan_host_selected(shost, channel, id, lun,
 351                                                 SCSI_SCAN_MANUAL);
 352         scsi_host_put(shost);
 353         return error;
 354 }
 355
 356 /**
 357  * scsi_remove_single_device - Respond to user request to remove a device
 358  * @host: user-supplied decimal integer
 359  * @channel: user-supplied decimal integer
 360  * @id: user-supplied decimal integer
 361  * @lun: user-supplied decimal integer
 362  *
 363  * Description: called by writing "scsi remove-single-device" to
 364  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
 365  */
 366 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
 367 {
 368         struct scsi_device *sdev;
 369         struct Scsi_Host *shost;
 370         int error = -ENXIO;
 371
 372         shost = scsi_host_lookup(host);
 373         if (!shost)
 374                 return error;
 375         sdev = scsi_device_lookup(shost, channel, id, lun);
 376         if (sdev) {
 377                 scsi_remove_device(sdev);
 378                 scsi_device_put(sdev);
 379                 error = 0;
 380         }
 381
 382         scsi_host_put(shost);
 383         return error;
 384 }
 385
 386 /**
 387  * proc_scsi_write - handle writes to /proc/scsi/scsi
 388  * @file: not used
 389  * @buf: buffer to write
 390  * @length: length of buf, at most PAGE_SIZE
 391  * @ppos: not used
 392  *
 393  * Description: this provides a legacy mechanism to add or remove devices by
 394  * Host, Channel, ID, and Lun.  To use,
 395  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
 396  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
 397  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
 398  *
 399  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
 400  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
 401  * provide a unique identifier and nothing more.
 402  */
 403
 404
 405 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
 406                                size_t length, loff_t *ppos)
 407 {
 408         int host, channel, id, lun;
 409         char *buffer, *end, *p;
 410         int err;
 411
 412         if (!buf || length > PAGE_SIZE)
 413                 return -EINVAL;
 414
 415         buffer = (char *)__get_free_page(GFP_KERNEL);
 416         if (!buffer)
 417                 return -ENOMEM;
 418
 419         err = -EFAULT;
 420         if (copy_from_user(buffer, buf, length))
 421                 goto out;
 422
 423         err = -EINVAL;
 424         if (length < PAGE_SIZE) {
 425                 end = buffer + length;
 426                 *end = '\0';
 427         } else {
 428                 end = buffer + PAGE_SIZE - 1;
 429                 if (*end)
 430                         goto out;
 431         }
 432
 433         /*
 434          * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
 435          * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
 436          */
 437         if (!strncmp("scsi add-single-device", buffer, 22)) {
 438                 p = buffer + 23;
 439
 440                 host    = (p     < end) ? simple_strtoul(p, &p, 0) : 0;
 441                 channel = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
 442                 id      = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
 443                 lun     = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
 444
 445                 err = scsi_add_single_device(host, channel, id, lun);
 446
 447         /*
 448          * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
 449          * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
 450          */
 451         } else if (!strncmp("scsi remove-single-device", buffer, 25)) {
 452                 p = buffer + 26;
 453
 454                 host    = (p     < end) ? simple_strtoul(p, &p, 0) : 0;
 455                 channel = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
 456                 id      = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
 457                 lun     = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
 458
 459                 err = scsi_remove_single_device(host, channel, id, lun);
 460         }
 461
 462         /*
 463          * convert success returns so that we return the
 464          * number of bytes consumed.
 465          */
 466         if (!err)
 467                 err = length;
 468
 469  out:
 470         free_page((unsigned long)buffer);
 471         return err;
 472 }
 473
 474 static inline struct device *next_scsi_device(struct device *start)
 475 {
 476         struct device *next = bus_find_next_device(&scsi_bus_type, start);
 477
 478         put_device(start);
 479         return next;
 480 }
 481
 482 static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
 483 {
 484         struct device *dev = NULL;
 485         loff_t n = *pos;
 486
 487         while ((dev = next_scsi_device(dev))) {
 488                 if (!n--)
 489                         break;
 490                 sfile->private++;
 491         }
 492         return dev;
 493 }
 494
 495 static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
 496 {
 497         (*pos)++;
 498         sfile->private++;
 499         return next_scsi_device(v);
 500 }
 501
 502 static void scsi_seq_stop(struct seq_file *sfile, void *v)
 503 {
 504         put_device(v);
 505 }
 506
 507 static int scsi_seq_show(struct seq_file *sfile, void *dev)
 508 {
 509         if (!sfile->private)
 510                 seq_puts(sfile, "Attached devices:\n");
 511
 512         return proc_print_scsidevice(dev, sfile);
 513 }
 514
 515 static const struct seq_operations scsi_seq_ops = {
 516         .start  = scsi_seq_start,
 517         .next   = scsi_seq_next,
 518         .stop   = scsi_seq_stop,
 519         .show   = scsi_seq_show
 520 };
 521
 522 /**
 523  * proc_scsi_open - glue function
 524  * @inode: not used
 525  * @file: passed to single_open()
 526  *
 527  * Associates proc_scsi_show with this file
 528  */
 529 static int proc_scsi_open(struct inode *inode, struct file *file)
 530 {
 531         /*
 532          * We don't really need this for the write case but it doesn't
 533          * harm either.
 534          */
 535         return seq_open(file, &scsi_seq_ops);
 536 }
 537
 538 static const struct proc_ops scsi_scsi_proc_ops = {
 539         .proc_open      = proc_scsi_open,
 540         .proc_read      = seq_read,
 541         .proc_write     = proc_scsi_write,
 542         .proc_lseek     = seq_lseek,
 543         .proc_release   = seq_release,
 544 };
 545
 546 /**
 547  * scsi_init_procfs - create scsi and scsi/scsi in procfs
 548  */
 549 int __init scsi_init_procfs(void)
 550 {
 551         struct proc_dir_entry *pde;
 552
 553         proc_scsi = proc_mkdir("scsi", NULL);
 554         if (!proc_scsi)
 555                 goto err1;
 556
 557         pde = proc_create("scsi/scsi", 0, NULL, &scsi_scsi_proc_ops);
 558         if (!pde)
 559                 goto err2;
 560
 561         return 0;
 562
 563 err2:
 564         remove_proc_entry("scsi", NULL);
 565 err1:
 566         return -ENOMEM;
 567 }
 568
 569 /**
 570  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
 571  */
 572 void scsi_exit_procfs(void)
 573 {
 574         remove_proc_entry("scsi/scsi", NULL);
 575         remove_proc_entry("scsi", NULL);
 576 }