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 static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
 101                            size_t count, loff_t *ppos)
 102 {
 103         struct Scsi_Host *shost = PDE(file_inode(file))->data;
 104         ssize_t ret = -ENOMEM;
 105         char *page;
 106
 107         if (count > PROC_BLOCK_SIZE)
 108                 return -EOVERFLOW;
 109
 110         if (!shost->hostt->write_info)
 111                 return -EINVAL;
 112
 113         page = (char *)__get_free_page(GFP_KERNEL);
 114         if (page) {
 115                 ret = -EFAULT;
 116                 if (copy_from_user(page, buf, count))
 117                         goto out;
 118                 ret = shost->hostt->write_info(shost, page, count);
 119         }
 120 out:
 121         free_page((unsigned long)page);
 122         return ret;
 123 }
 124
 125 static int proc_scsi_show(struct seq_file *m, void *v)
 126 {
 127         struct Scsi_Host *shost = m->private;
 128         return shost->hostt->show_info(m, shost);
 129 }
 130
 131 static int proc_scsi_host_open(struct inode *inode, struct file *file)
 132 {
 133         return single_open(file, proc_scsi_show, PDE(inode)->data);
 134 }
 135
 136 static const struct file_operations proc_scsi_fops = {
 137         .open = proc_scsi_host_open,
 138         .read = seq_read,
 139         .llseek = seq_lseek,
 140         .write = proc_scsi_host_write
 141 };
 142
 143 /**
 144  * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
 145  * @sht: owner of this directory
 146  *
 147  * Sets sht->proc_dir to the new directory.
 148  */
 149
 150 void scsi_proc_hostdir_add(struct scsi_host_template *sht)
 151 {
 152         if (!sht->proc_info && !sht->show_info)
 153                 return;
 154
 155         mutex_lock(&global_host_template_mutex);
 156         if (!sht->present++) {
 157                 sht->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
 158                 if (!sht->proc_dir)
 159                         printk(KERN_ERR "%s: proc_mkdir failed for %s\n",
 160                                __func__, sht->proc_name);
 161         }
 162         mutex_unlock(&global_host_template_mutex);
 163 }
 164
 165 /**
 166  * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
 167  * @sht: owner of directory
 168  */
 169 void scsi_proc_hostdir_rm(struct scsi_host_template *sht)
 170 {
 171         if (!sht->proc_info && !sht->show_info)
 172                 return;
 173
 174         mutex_lock(&global_host_template_mutex);
 175         if (!--sht->present && sht->proc_dir) {
 176                 remove_proc_entry(sht->proc_name, proc_scsi);
 177                 sht->proc_dir = NULL;
 178         }
 179         mutex_unlock(&global_host_template_mutex);
 180 }
 181
 182
 183 /**
 184  * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
 185  * @shost: host to add
 186  */
 187 void scsi_proc_host_add(struct Scsi_Host *shost)
 188 {
 189         struct scsi_host_template *sht = shost->hostt;
 190         struct proc_dir_entry *p;
 191         char name[10];
 192
 193         if (!sht->proc_dir)
 194                 return;
 195
 196         sprintf(name,"%d", shost->host_no);
 197         if (sht->show_info) {
 198                 p = proc_create_data(name, S_IRUGO | S_IWUSR,
 199                         sht->proc_dir, &proc_scsi_fops, shost);
 200                 if (!p)
 201                         goto Fail;
 202                 return;
 203         }
 204         p = create_proc_read_entry(name, S_IFREG | S_IRUGO | S_IWUSR,
 205                         sht->proc_dir, proc_scsi_read, shost);
 206         if (p) {
 207                 p->write_proc = proc_scsi_write_proc;
 208                 return;
 209         }
 210 Fail:
 211         printk(KERN_ERR "%s: Failed to register host %d in"
 212                "%s\n", __func__, shost->host_no,
 213                sht->proc_name);
 214 }
 215
 216 /**
 217  * scsi_proc_host_rm - remove this host's entry from /proc
 218  * @shost: which host
 219  */
 220 void scsi_proc_host_rm(struct Scsi_Host *shost)
 221 {
 222         char name[10];
 223
 224         if (!shost->hostt->proc_dir)
 225                 return;
 226
 227         sprintf(name,"%d", shost->host_no);
 228         remove_proc_entry(name, shost->hostt->proc_dir);
 229 }
 230 /**
 231  * proc_print_scsidevice - return data about this host
 232  * @dev: A scsi device
 233  * @data: &struct seq_file to output to.
 234  *
 235  * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
 236  * and revision.
 237  */
 238 static int proc_print_scsidevice(struct device *dev, void *data)
 239 {
 240         struct scsi_device *sdev;
 241         struct seq_file *s = data;
 242         int i;
 243
 244         if (!scsi_is_sdev_device(dev))
 245                 goto out;
 246
 247         sdev = to_scsi_device(dev);
 248         seq_printf(s,
 249                 "Host: scsi%d Channel: %02d Id: %02d Lun: %02d\n  Vendor: ",
 250                 sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
 251         for (i = 0; i < 8; i++) {
 252                 if (sdev->vendor[i] >= 0x20)
 253                         seq_printf(s, "%c", sdev->vendor[i]);
 254                 else
 255                         seq_printf(s, " ");
 256         }
 257
 258         seq_printf(s, " Model: ");
 259         for (i = 0; i < 16; i++) {
 260                 if (sdev->model[i] >= 0x20)
 261                         seq_printf(s, "%c", sdev->model[i]);
 262                 else
 263                         seq_printf(s, " ");
 264         }
 265
 266         seq_printf(s, " Rev: ");
 267         for (i = 0; i < 4; i++) {
 268                 if (sdev->rev[i] >= 0x20)
 269                         seq_printf(s, "%c", sdev->rev[i]);
 270                 else
 271                         seq_printf(s, " ");
 272         }
 273
 274         seq_printf(s, "\n");
 275
 276         seq_printf(s, "  Type:   %s ", scsi_device_type(sdev->type));
 277         seq_printf(s, "               ANSI  SCSI revision: %02x",
 278                         sdev->scsi_level - (sdev->scsi_level > 1));
 279         if (sdev->scsi_level == 2)
 280                 seq_printf(s, " CCS\n");
 281         else
 282                 seq_printf(s, "\n");
 283
 284 out:
 285         return 0;
 286 }
 287
 288 /**
 289  * scsi_add_single_device - Respond to user request to probe for/add device
 290  * @host: user-supplied decimal integer
 291  * @channel: user-supplied decimal integer
 292  * @id: user-supplied decimal integer
 293  * @lun: user-supplied decimal integer
 294  *
 295  * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
 296  *
 297  * does scsi_host_lookup() and either user_scan() if that transport
 298  * type supports it, or else scsi_scan_host_selected()
 299  *
 300  * Note: this seems to be aimed exclusively at SCSI parallel busses.
 301  */
 302
 303 static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
 304 {
 305         struct Scsi_Host *shost;
 306         int error = -ENXIO;
 307
 308         shost = scsi_host_lookup(host);
 309         if (!shost)
 310                 return error;
 311
 312         if (shost->transportt->user_scan)
 313                 error = shost->transportt->user_scan(shost, channel, id, lun);
 314         else
 315                 error = scsi_scan_host_selected(shost, channel, id, lun, 1);
 316         scsi_host_put(shost);
 317         return error;
 318 }
 319
 320 /**
 321  * scsi_remove_single_device - Respond to user request to remove a device
 322  * @host: user-supplied decimal integer
 323  * @channel: user-supplied decimal integer
 324  * @id: user-supplied decimal integer
 325  * @lun: user-supplied decimal integer
 326  *
 327  * Description: called by writing "scsi remove-single-device" to
 328  * /proc/scsi/scsi.  Does a scsi_device_lookup() and scsi_remove_device()
 329  */
 330 static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
 331 {
 332         struct scsi_device *sdev;
 333         struct Scsi_Host *shost;
 334         int error = -ENXIO;
 335
 336         shost = scsi_host_lookup(host);
 337         if (!shost)
 338                 return error;
 339         sdev = scsi_device_lookup(shost, channel, id, lun);
 340         if (sdev) {
 341                 scsi_remove_device(sdev);
 342                 scsi_device_put(sdev);
 343                 error = 0;
 344         }
 345
 346         scsi_host_put(shost);
 347         return error;
 348 }
 349
 350 /**
 351  * proc_scsi_write - handle writes to /proc/scsi/scsi
 352  * @file: not used
 353  * @buf: buffer to write
 354  * @length: length of buf, at most PAGE_SIZE
 355  * @ppos: not used
 356  *
 357  * Description: this provides a legacy mechanism to add or remove devices by
 358  * Host, Channel, ID, and Lun.  To use,
 359  * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
 360  * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
 361  * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
 362  *
 363  * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
 364  * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
 365  * provide a unique identifier and nothing more.
 366  */
 367
 368
 369 static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
 370                                size_t length, loff_t *ppos)
 371 {
 372         int host, channel, id, lun;
 373         char *buffer, *p;
 374         int err;
 375
 376         if (!buf || length > PAGE_SIZE)
 377                 return -EINVAL;
 378
 379         buffer = (char *)__get_free_page(GFP_KERNEL);
 380         if (!buffer)
 381                 return -ENOMEM;
 382
 383         err = -EFAULT;
 384         if (copy_from_user(buffer, buf, length))
 385                 goto out;
 386
 387         err = -EINVAL;
 388         if (length < PAGE_SIZE)
 389                 buffer[length] = '\0';
 390         else if (buffer[PAGE_SIZE-1])
 391                 goto out;
 392
 393         /*
 394          * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
 395          * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
 396          */
 397         if (!strncmp("scsi add-single-device", buffer, 22)) {
 398                 p = buffer + 23;
 399
 400                 host = simple_strtoul(p, &p, 0);
 401                 channel = simple_strtoul(p + 1, &p, 0);
 402                 id = simple_strtoul(p + 1, &p, 0);
 403                 lun = simple_strtoul(p + 1, &p, 0);
 404
 405                 err = scsi_add_single_device(host, channel, id, lun);
 406
 407         /*
 408          * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
 409          * with  "0 1 2 3" replaced by your "Host Channel Id Lun".
 410          */
 411         } else if (!strncmp("scsi remove-single-device", buffer, 25)) {
 412                 p = buffer + 26;
 413
 414                 host = simple_strtoul(p, &p, 0);
 415                 channel = simple_strtoul(p + 1, &p, 0);
 416                 id = simple_strtoul(p + 1, &p, 0);
 417                 lun = simple_strtoul(p + 1, &p, 0);
 418
 419                 err = scsi_remove_single_device(host, channel, id, lun);
 420         }
 421
 422         /*
 423          * convert success returns so that we return the
 424          * number of bytes consumed.
 425          */
 426         if (!err)
 427                 err = length;
 428
 429  out:
 430         free_page((unsigned long)buffer);
 431         return err;
 432 }
 433
 434 static int always_match(struct device *dev, void *data)
 435 {
 436         return 1;
 437 }
 438
 439 static inline struct device *next_scsi_device(struct device *start)
 440 {
 441         struct device *next = bus_find_device(&scsi_bus_type, start, NULL,
 442                                               always_match);
 443         put_device(start);
 444         return next;
 445 }
 446
 447 static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
 448 {
 449         struct device *dev = NULL;
 450         loff_t n = *pos;
 451
 452         while ((dev = next_scsi_device(dev))) {
 453                 if (!n--)
 454                         break;
 455                 sfile->private++;
 456         }
 457         return dev;
 458 }
 459
 460 static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
 461 {
 462         (*pos)++;
 463         sfile->private++;
 464         return next_scsi_device(v);
 465 }
 466
 467 static void scsi_seq_stop(struct seq_file *sfile, void *v)
 468 {
 469         put_device(v);
 470 }
 471
 472 static int scsi_seq_show(struct seq_file *sfile, void *dev)
 473 {
 474         if (!sfile->private)
 475                 seq_puts(sfile, "Attached devices:\n");
 476
 477         return proc_print_scsidevice(dev, sfile);
 478 }
 479
 480 static const struct seq_operations scsi_seq_ops = {
 481         .start  = scsi_seq_start,
 482         .next   = scsi_seq_next,
 483         .stop   = scsi_seq_stop,
 484         .show   = scsi_seq_show
 485 };
 486
 487 /**
 488  * proc_scsi_open - glue function
 489  * @inode: not used
 490  * @file: passed to single_open()
 491  *
 492  * Associates proc_scsi_show with this file
 493  */
 494 static int proc_scsi_open(struct inode *inode, struct file *file)
 495 {
 496         /*
 497          * We don't really need this for the write case but it doesn't
 498          * harm either.
 499          */
 500         return seq_open(file, &scsi_seq_ops);
 501 }
 502
 503 static const struct file_operations proc_scsi_operations = {
 504         .owner          = THIS_MODULE,
 505         .open           = proc_scsi_open,
 506         .read           = seq_read,
 507         .write          = proc_scsi_write,
 508         .llseek         = seq_lseek,
 509         .release        = seq_release,
 510 };
 511
 512 /**
 513  * scsi_init_procfs - create scsi and scsi/scsi in procfs
 514  */
 515 int __init scsi_init_procfs(void)
 516 {
 517         struct proc_dir_entry *pde;
 518
 519         proc_scsi = proc_mkdir("scsi", NULL);
 520         if (!proc_scsi)
 521                 goto err1;
 522
 523         pde = proc_create("scsi/scsi", 0, NULL, &proc_scsi_operations);
 524         if (!pde)
 525                 goto err2;
 526
 527         return 0;
 528
 529 err2:
 530         remove_proc_entry("scsi", NULL);
 531 err1:
 532         return -ENOMEM;
 533 }
 534
 535 /**
 536  * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
 537  */
 538 void scsi_exit_procfs(void)
 539 {
 540         remove_proc_entry("scsi/scsi", NULL);
 541         remove_proc_entry("scsi", NULL);
 542 }