fs/proc/root.c

/* */
This source file includes following definitions.
proc_register
proc_unregister
proc_self_followlink
proc_self_readlink
proc_root_init
proc_match
proc_lookup
proc_root_lookup
proc_readdir
proc_root_readdir
   1 /*
   2  *  linux/fs/proc/root.c
   3  *
   4  *  Copyright (C) 1991, 1992 Linus Torvalds
   5  *
   6  *  proc root directory handling functions
   7  */
   8 
   9 #include <asm/segment.h>
  10 
  11 #include <linux/errno.h>
  12 #include <linux/sched.h>
  13 #include <linux/proc_fs.h>
  14 #include <linux/stat.h>
  15 #include <linux/config.h>
  16 #ifdef CONFIG_APM
  17 #include <linux/apm_bios.h>
  18 #endif
  19 
  20 /*
  21  * Offset of the first process in the /proc root directory..
  22  */
  23 #define FIRST_PROCESS_ENTRY 256
  24 
  25 static int proc_root_readdir(struct inode *, struct file *, void *, filldir_t);
  26 static int proc_root_lookup(struct inode *,const char *,int,struct inode **);
  27 
  28 /*
  29  * These are the generic /proc directory operations. They
  30  * use the in-memory "struct proc_dir_entry" tree to parse
  31  * the /proc directory.
  32  *
  33  * NOTE! The /proc/scsi directory currently does not correctly
  34  * build up the proc_dir_entry tree, and will show up empty.
  35  */
  36 static struct file_operations proc_dir_operations = {
  37         NULL,                   /* lseek - default */
  38         NULL,                   /* read - bad */
  39         NULL,                   /* write - bad */
  40         proc_readdir,           /* readdir */
  41         NULL,                   /* select - default */
  42         NULL,                   /* ioctl - default */
  43         NULL,                   /* mmap */
  44         NULL,                   /* no special open code */
  45         NULL,                   /* no special release code */
  46         NULL                    /* can't fsync */
  47 };
  48 
  49 /*
  50  * proc directories can do almost nothing..
  51  */
  52 static struct inode_operations proc_dir_inode_operations = {
  53         &proc_dir_operations,   /* default net directory file-ops */
  54         NULL,                   /* create */
  55         proc_lookup,            /* lookup */
  56         NULL,                   /* link */
  57         NULL,                   /* unlink */
  58         NULL,                   /* symlink */
  59         NULL,                   /* mkdir */
  60         NULL,                   /* rmdir */
  61         NULL,                   /* mknod */
  62         NULL,                   /* rename */
  63         NULL,                   /* readlink */
  64         NULL,                   /* follow_link */
  65         NULL,                   /* readpage */
  66         NULL,                   /* writepage */
  67         NULL,                   /* bmap */
  68         NULL,                   /* truncate */
  69         NULL                    /* permission */
  70 };
  71 
  72 /*
  73  * The root /proc directory is special, as it has the
  74  * <pid> directories. Thus we don't use the generic
  75  * directory handling functions for that..
  76  */
  77 static struct file_operations proc_root_operations = {
  78         NULL,                   /* lseek - default */
  79         NULL,                   /* read - bad */
  80         NULL,                   /* write - bad */
  81         proc_root_readdir,      /* readdir */
  82         NULL,                   /* select - default */
  83         NULL,                   /* ioctl - default */
  84         NULL,                   /* mmap */
  85         NULL,                   /* no special open code */
  86         NULL,                   /* no special release code */
  87         NULL                    /* no fsync */
  88 };
  89 
  90 /*
  91  * proc root can do almost nothing..
  92  */
  93 static struct inode_operations proc_root_inode_operations = {
  94         &proc_root_operations,  /* default base directory file-ops */
  95         NULL,                   /* create */
  96         proc_root_lookup,       /* lookup */
  97         NULL,                   /* link */
  98         NULL,                   /* unlink */
  99         NULL,                   /* symlink */
 100         NULL,                   /* mkdir */
 101         NULL,                   /* rmdir */
 102         NULL,                   /* mknod */
 103         NULL,                   /* rename */
 104         NULL,                   /* readlink */
 105         NULL,                   /* follow_link */
 106         NULL,                   /* readpage */
 107         NULL,                   /* writepage */
 108         NULL,                   /* bmap */
 109         NULL,                   /* truncate */
 110         NULL                    /* permission */
 111 };
 112 
 113 /*
 114  * This is the root "inode" in the /proc tree..
 115  */
 116 struct proc_dir_entry proc_root = {
 117         PROC_ROOT_INO, 5, "/proc",
 118         S_IFDIR | S_IRUGO | S_IXUGO, 2, 0, 0,
 119         0, &proc_root_inode_operations,
 120         NULL, NULL,
 121         NULL,
 122         &proc_root, NULL
 123 };
 124 
 125 struct proc_dir_entry proc_net = {
 126         PROC_NET, 3, "net",
 127         S_IFDIR | S_IRUGO | S_IXUGO, 2, 0, 0,
 128         0, &proc_dir_inode_operations,
 129         NULL, NULL,
 130         NULL,
 131         NULL, NULL      
 132 };
 133 
 134 struct proc_dir_entry proc_scsi = {
 135         PROC_SCSI, 4, "scsi",
 136         S_IFDIR | S_IRUGO | S_IXUGO, 2, 0, 0,
 137         0, &proc_dir_inode_operations,
 138         NULL, NULL,
 139         NULL, &proc_root, NULL
 140 };
 141 
 142 int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
     /*  */
 143 {
 144         dp->next = dir->subdir;
 145         dp->parent = dir;
 146         dir->subdir = dp;
 147         if (S_ISDIR(dp->mode))
 148                 dir->nlink++;
 149         return 0;
 150 }
 151 
 152 int proc_unregister(struct proc_dir_entry * dir, int ino)
     /*  */
 153 {
 154         struct proc_dir_entry **p = &dir->subdir, *dp;
 155 
 156         while ((dp = *p) != NULL) {
 157                 if (dp->low_ino == ino) {
 158                         *p = dp->next;
 159                         dp->next = NULL;
 160                         if (S_ISDIR(dp->mode))
 161                                 dir->nlink--;
 162                         return 0;
 163                 }
 164                 p = &dp->next;
 165         }
 166         return -EINVAL;
 167 }       
 168 
 169 /*
 170  * /proc/self:
 171  */
 172 static int proc_self_followlink(struct inode * dir, struct inode * inode,
     /*  */
 173                         int flag, int mode, struct inode ** res_inode)
 174 {
 175         iput(dir);
 176         *res_inode = proc_get_inode(inode->i_sb, (current->pid << 16) + PROC_PID_INO, &proc_pid);
 177         iput(inode);
 178         if (!*res_inode)
 179                 return -ENOENT;
 180         return 0;
 181 }
 182 
 183 static int proc_self_readlink(struct inode * inode, char * buffer, int buflen)
     /*  */
 184 {
 185         int len;
 186         char tmp[30];
 187 
 188         iput(inode);
 189         len = 1 + sprintf(tmp, "%d", current->pid);
 190         if (buflen < len)
 191                 len = buflen;
 192         memcpy_tofs(buffer, tmp, len);
 193         return len;
 194 }
 195 
 196 static struct inode_operations proc_self_inode_operations = {
 197         NULL,                   /* no file-ops */
 198         NULL,                   /* create */
 199         NULL,                   /* lookup */
 200         NULL,                   /* link */
 201         NULL,                   /* unlink */
 202         NULL,                   /* symlink */
 203         NULL,                   /* mkdir */
 204         NULL,                   /* rmdir */
 205         NULL,                   /* mknod */
 206         NULL,                   /* rename */
 207         proc_self_readlink,     /* readlink */
 208         proc_self_followlink,   /* follow_link */
 209         NULL,                   /* readpage */
 210         NULL,                   /* writepage */
 211         NULL,                   /* bmap */
 212         NULL,                   /* truncate */
 213         NULL                    /* permission */
 214 };
 215 
 216 void proc_root_init(void)
     /*  */
 217 {
 218         static int done = 0;
 219 
 220         if (done)
 221                 return;
 222         done = 1;
 223         proc_base_init();
 224         proc_register(&proc_root, &(struct proc_dir_entry) {
 225                 PROC_LOADAVG, 7, "loadavg",
 226                 S_IFREG | S_IRUGO, 1, 0, 0,
 227         });
 228         proc_register(&proc_root, &(struct proc_dir_entry) {
 229                 PROC_UPTIME, 6, "uptime",
 230                 S_IFREG | S_IRUGO, 1, 0, 0,
 231         });
 232         proc_register(&proc_root, &(struct proc_dir_entry) {
 233                 PROC_MEMINFO, 7, "meminfo",
 234                 S_IFREG | S_IRUGO, 1, 0, 0,
 235         });
 236         proc_register(&proc_root, &(struct proc_dir_entry) {
 237                 PROC_KMSG, 4, "kmsg",
 238                 S_IFREG | S_IRUSR, 1, 0, 0,
 239         });
 240         proc_register(&proc_root, &(struct proc_dir_entry) {
 241                 PROC_VERSION, 7, "version",
 242                 S_IFREG | S_IRUGO, 1, 0, 0,
 243         });
 244 #ifdef CONFIG_PCI
 245         proc_register(&proc_root, &(struct proc_dir_entry) {
 246                 PROC_PCI, 3, "pci",
 247                 S_IFREG | S_IRUGO, 1, 0, 0,
 248         });
 249 #endif
 250         proc_register(&proc_root, &(struct proc_dir_entry) {
 251                 PROC_CPUINFO, 7, "cpuinfo",
 252                 S_IFREG | S_IRUGO, 1, 0, 0,
 253         });
 254         proc_register(&proc_root, &(struct proc_dir_entry) {
 255                 PROC_SELF, 4, "self",
 256                 S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO, 1, 0, 0,
 257                 64, &proc_self_inode_operations,
 258         });
 259         proc_register(&proc_root, &proc_net);
 260 
 261 #ifdef CONFIG_SCSI
 262         proc_register(&proc_root, &proc_scsi);
 263 #endif
 264 
 265 #ifdef CONFIG_DEBUG_MALLOC
 266         proc_register(&proc_root, &(struct proc_dir_entry) {
 267                 PROC_MALLOC, 6, "malloc",
 268                 S_IFREG | S_IRUGO, 1, 0, 0,
 269         });
 270 #endif
 271         proc_register(&proc_root, &(struct proc_dir_entry) {
 272                 PROC_KCORE, 5, "kcore",
 273                 S_IFREG | S_IRUSR, 1, 0, 0,
 274         });
 275 
 276 #ifdef CONFIG_MODULES
 277         proc_register(&proc_root, &(struct proc_dir_entry) {
 278                 PROC_MODULES, 7, "modules",
 279                 S_IFREG | S_IRUGO, 1, 0, 0,
 280         });
 281         proc_register(&proc_root, &(struct proc_dir_entry) {
 282                 PROC_KSYMS, 5, "ksyms",
 283                 S_IFREG | S_IRUGO, 1, 0, 0,
 284         });
 285 #endif
 286         proc_register(&proc_root, &(struct proc_dir_entry) {
 287                 PROC_STAT, 4, "stat",
 288                 S_IFREG | S_IRUGO, 1, 0, 0,
 289         });
 290         proc_register(&proc_root, &(struct proc_dir_entry) {
 291                 PROC_DEVICES, 7, "devices",
 292                 S_IFREG | S_IRUGO, 1, 0, 0,
 293         });
 294         proc_register(&proc_root, &(struct proc_dir_entry) {
 295                 PROC_INTERRUPTS, 10,"interrupts",
 296                 S_IFREG | S_IRUGO, 1, 0, 0,
 297         });
 298         proc_register(&proc_root, &(struct proc_dir_entry) {
 299                 PROC_FILESYSTEMS, 11,"filesystems",
 300                 S_IFREG | S_IRUGO, 1, 0, 0,
 301         });
 302         proc_register(&proc_root, &(struct proc_dir_entry) {
 303                 PROC_DMA, 3, "dma",
 304                 S_IFREG | S_IRUGO, 1, 0, 0,
 305         });
 306         proc_register(&proc_root, &(struct proc_dir_entry) {
 307                 PROC_IOPORTS, 7, "ioports",
 308                 S_IFREG | S_IRUGO, 1, 0, 0,
 309         });
 310 #ifdef CONFIG_APM
 311         proc_register(&proc_root, &(struct proc_dir_entry) {
 312                 PROC_APM, 3, "apm",
 313                 S_IFREG | S_IRUGO, 1, 0, 0,
 314         });
 315 #endif
 316         proc_register(&proc_root, &(struct proc_dir_entry) {
 317                 PROC_CMDLINE, 7, "cmdline",
 318                 S_IFREG | S_IRUGO, 1, 0, 0,
 319         });
 320                    
 321         if (prof_shift) {
 322                 proc_register(&proc_root, &(struct proc_dir_entry) {
 323                         PROC_PROFILE, 7, "profile",
 324                         S_IFREG | S_IRUGO | S_IWUSR, 1, 0, 0,
 325                 });
 326         }
 327 }
 328 
 329 
 330 int proc_match(int len,const char * name,struct proc_dir_entry * de)
     /*  */
 331 {
 332         if (!de || !de->low_ino)
 333                 return 0;
 334         /* "" means "." ---> so paths like "/usr/lib//libc.a" work */
 335         if (!len && (de->name[0]=='.') && (de->name[1]=='\0'))
 336                 return 1;
 337         if (de->namelen != len)
 338                 return 0;
 339         return !memcmp(name, de->name, len);
 340 }
 341 
 342 int proc_lookup(struct inode * dir,const char * name, int len,
     /*  */
 343         struct inode ** result)
 344 {
 345         struct proc_dir_entry * de;
 346         int ino;
 347 
 348         *result = NULL;
 349         if (!dir || !S_ISDIR(dir->i_mode)) {
 350                 iput(dir);
 351                 return -ENOTDIR;
 352         }
 353 
 354         de = (struct proc_dir_entry *) dir->u.generic_ip;
 355         if (!de) {
 356                 iput(dir);
 357                 return -EINVAL;
 358         }
 359 
 360         /* Special case "." and "..": they aren't on the directory list */
 361         *result = dir;
 362         if (!len)
 363                 return 0;
 364         if (name[0] == '.') {
 365                 if (len == 1)
 366                         return 0;
 367                 if (name[1] == '.' && len == 2) {
 368                         struct inode * inode;
 369                         inode = proc_get_inode(dir->i_sb, de->parent->low_ino, de->parent);
 370                         iput(dir);
 371                         if (!inode)
 372                                 return -EINVAL;
 373                         *result = inode;
 374                         return 0;
 375                 }
 376         }
 377 
 378         *result = NULL;
 379         for (de = de->subdir; de ; de = de->next) {
 380                 if (proc_match(len, name, de))
 381                         break;
 382         }
 383         if (!de) {
 384                 iput(dir);
 385                 return -ENOENT;
 386         }
 387 
 388         ino = de->low_ino | (dir->i_ino & ~(0xffff));
 389 
 390         if (!(*result = proc_get_inode(dir->i_sb, ino, de))) {
 391                 iput(dir);
 392                 return -EINVAL;
 393         }
 394         iput(dir);
 395         return 0;
 396 }
 397 
 398 static int proc_root_lookup(struct inode * dir,const char * name, int len,
     /*  */
 399         struct inode ** result)
 400 {
 401         unsigned int pid, c;
 402         int i, ino, retval;
 403 
 404         dir->i_count++;
 405         retval = proc_lookup(dir, name, len, result);
 406         if (retval != -ENOENT) {
 407                 iput(dir);
 408                 return retval;
 409         }
 410         
 411         pid = 0;
 412         while (len-- > 0) {
 413                 c = *name - '0';
 414                 name++;
 415                 if (c > 9) {
 416                         pid = 0;
 417                         break;
 418                 }
 419                 pid *= 10;
 420                 pid += c;
 421                 if (pid & 0xffff0000) {
 422                         pid = 0;
 423                         break;
 424                 }
 425         }
 426         for (i = 0 ; i < NR_TASKS ; i++)
 427                 if (task[i] && task[i]->pid == pid)
 428                         break;
 429         if (!pid || i >= NR_TASKS) {
 430                 iput(dir);
 431                 return -ENOENT;
 432         }
 433         ino = (pid << 16) + PROC_PID_INO;
 434         if (!(*result = proc_get_inode(dir->i_sb, ino, &proc_pid))) {
 435                 iput(dir);
 436                 return -EINVAL;
 437         }
 438         iput(dir);
 439         return 0;
 440 }
 441 
 442 /*
 443  * This returns non-zero if at EOF, so that the /proc
 444  * root directory can use this and check if it should
 445  * continue with the <pid> entries..
 446  *
 447  * Note that the VFS-layer doesn't care about the return
 448  * value of the readdir() call, as long as it's non-negative
 449  * for success..
 450  */
 451 int proc_readdir(struct inode * inode, struct file * filp,
     /*  */
 452         void * dirent, filldir_t filldir)
 453 {
 454         struct proc_dir_entry * de;
 455         unsigned int ino;
 456         int i;
 457 
 458         if (!inode || !S_ISDIR(inode->i_mode))
 459                 return -ENOTDIR;
 460         ino = inode->i_ino;
 461         de = (struct proc_dir_entry *) inode->u.generic_ip;
 462         if (!de)
 463                 return -EINVAL;
 464         i = filp->f_pos;
 465         switch (i) {
 466                 case 0:
 467                         if (filldir(dirent, ".", 1, i, ino) < 0)
 468                                 return 0;
 469                         i++;
 470                         filp->f_pos++;
 471                         /* fall through */
 472                 case 1:
 473                         if (filldir(dirent, "..", 2, i, de->parent->low_ino) < 0)
 474                                 return 0;
 475                         i++;
 476                         filp->f_pos++;
 477                         /* fall through */
 478                 default:
 479                         ino &= ~0xffff;
 480                         de = de->subdir;
 481                         i -= 2;
 482                         for (;;) {
 483                                 if (!de)
 484                                         return 1;
 485                                 if (!i)
 486                                         break;
 487                                 de = de->next;
 488                                 i--;
 489                         }
 490 
 491                         do {
 492                                 if (filldir(dirent, de->name, de->namelen, filp->f_pos, ino | de->low_ino) < 0)
 493                                         return 0;
 494                                 filp->f_pos++;
 495                                 de = de->next;
 496                         } while (de);
 497         }
 498         return 1;
 499 }
 500 
 501 #define NUMBUF 10
 502 
 503 static int proc_root_readdir(struct inode * inode, struct file * filp,
     /*  */
 504         void * dirent, filldir_t filldir)
 505 {
 506         char buf[NUMBUF];
 507         unsigned int nr,pid;
 508         unsigned long i,j;
 509 
 510         nr = filp->f_pos;
 511         if (nr < FIRST_PROCESS_ENTRY) {
 512                 int error = proc_readdir(inode, filp, dirent, filldir);
 513                 if (error <= 0)
 514                         return error;
 515                 filp->f_pos = nr = FIRST_PROCESS_ENTRY;
 516         }
 517 
 518         for (nr -= FIRST_PROCESS_ENTRY; nr < NR_TASKS; nr++, filp->f_pos++) {
 519                 struct task_struct * p = task[nr];
 520 
 521                 if (!p || !(pid = p->pid))
 522                         continue;
 523 
 524                 j = NUMBUF;
 525                 i = pid;
 526                 do {
 527                         j--;
 528                         buf[j] = '0' + (i % 10);
 529                         i /= 10;
 530                 } while (i);
 531 
 532                 if (filldir(dirent, buf+j, NUMBUF-j, filp->f_pos, (pid << 16) + PROC_PID_INO) < 0)
 533                         break;
 534         }
 535         return 0;
 536 }
/* */
root/fs/proc/root.c

DEFINITIONS
