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