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