fs/proc/root.c

/* */
This source file includes following definitions.
proc_register
proc_unregister
make_inode_number
proc_register_dynamic
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 #include <asm/bitops.h>
  17 
  18 /*
  19  * Offset of the first process in the /proc root directory..
  20  */
  21 #define FIRST_PROCESS_ENTRY 256
  22 
  23 static int proc_root_readdir(struct inode *, struct file *, void *, filldir_t);
  24 static int proc_root_lookup(struct inode *,const char *,int,struct inode **);
  25 
  26 static unsigned char proc_alloc_map[PROC_NDYNAMIC / 8] = {0};
  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 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 struct proc_dir_entry proc_sys_root = {
 143         PROC_SYS, 3, "sys",                     /* inode, name */
 144         S_IFDIR | S_IRUGO | S_IXUGO, 2, 0, 0,   /* mode, nlink, uid, gid */
 145         0, &proc_dir_inode_operations,          /* size, ops */
 146         NULL, NULL,                             /* get_info, fill_inode */
 147         NULL,                                   /* next */
 148         NULL, NULL                              /* parent, subdir */
 149 };
 150 
 151 int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
     /*  */
 152 {
 153         dp->next = dir->subdir;
 154         dp->parent = dir;
 155         dir->subdir = dp;
 156         if (S_ISDIR(dp->mode))
 157                 dir->nlink++;
 158         return 0;
 159 }
 160 
 161 int proc_unregister(struct proc_dir_entry * dir, int ino)
     /*  */
 162 {
 163         struct proc_dir_entry **p = &dir->subdir, *dp;
 164 
 165         while ((dp = *p) != NULL) {
 166                 if (dp->low_ino == ino) {
 167                         *p = dp->next;
 168                         dp->next = NULL;
 169                         if (S_ISDIR(dp->mode))
 170                                 dir->nlink--;
 171                         if (ino >= PROC_DYNAMIC_FIRST &&
 172                             ino < PROC_DYNAMIC_FIRST+PROC_NDYNAMIC)
 173                                 clear_bit(ino-PROC_DYNAMIC_FIRST, 
 174                                           (void *) proc_alloc_map);
 175                         return 0;
 176                 }
 177                 p = &dp->next;
 178         }
 179         return -EINVAL;
 180 }       
 181 
 182 static int make_inode_number(void)
     /*  */
 183 {
 184         int i = find_first_zero_bit((void *) proc_alloc_map, PROC_NDYNAMIC);
 185         if (i<0 || i>=PROC_NDYNAMIC) 
 186                 return -1;
 187         set_bit(i, (void *) proc_alloc_map);
 188         return PROC_DYNAMIC_FIRST + i;
 189 }
 190 
 191 int proc_register_dynamic(struct proc_dir_entry * dir,
     /*  */
 192                           struct proc_dir_entry * dp)
 193 {
 194         int i = make_inode_number();
 195         if (i < 0)
 196                 return -EAGAIN;
 197         dp->low_ino = i;
 198         dp->next = dir->subdir;
 199         dp->parent = dir;
 200         dir->subdir = dp;
 201         if (S_ISDIR(dp->mode))
 202                 dir->nlink++;
 203         return 0;
 204 }
 205 
 206 /*
 207  * /proc/self:
 208  */
 209 static int proc_self_followlink(struct inode * dir, struct inode * inode,
     /*  */
 210                         int flag, int mode, struct inode ** res_inode)
 211 {
 212         iput(dir);
 213         *res_inode = proc_get_inode(inode->i_sb, (current->pid << 16) + PROC_PID_INO, &proc_pid);
 214         iput(inode);
 215         if (!*res_inode)
 216                 return -ENOENT;
 217         return 0;
 218 }
 219 
 220 static int proc_self_readlink(struct inode * inode, char * buffer, int buflen)
     /*  */
 221 {
 222         int len;
 223         char tmp[30];
 224 
 225         iput(inode);
 226         len = 1 + sprintf(tmp, "%d", current->pid);
 227         if (buflen < len)
 228                 len = buflen;
 229         memcpy_tofs(buffer, tmp, len);
 230         return len;
 231 }
 232 
 233 static struct inode_operations proc_self_inode_operations = {
 234         NULL,                   /* no file-ops */
 235         NULL,                   /* create */
 236         NULL,                   /* lookup */
 237         NULL,                   /* link */
 238         NULL,                   /* unlink */
 239         NULL,                   /* symlink */
 240         NULL,                   /* mkdir */
 241         NULL,                   /* rmdir */
 242         NULL,                   /* mknod */
 243         NULL,                   /* rename */
 244         proc_self_readlink,     /* readlink */
 245         proc_self_followlink,   /* follow_link */
 246         NULL,                   /* readpage */
 247         NULL,                   /* writepage */
 248         NULL,                   /* bmap */
 249         NULL,                   /* truncate */
 250         NULL                    /* permission */
 251 };
 252 
 253 void proc_root_init(void)
     /*  */
 254 {
 255         static int done = 0;
 256 
 257         if (done)
 258                 return;
 259         done = 1;
 260         proc_base_init();
 261         proc_register(&proc_root, &(struct proc_dir_entry) {
 262                 PROC_LOADAVG, 7, "loadavg",
 263                 S_IFREG | S_IRUGO, 1, 0, 0,
 264         });
 265         proc_register(&proc_root, &(struct proc_dir_entry) {
 266                 PROC_UPTIME, 6, "uptime",
 267                 S_IFREG | S_IRUGO, 1, 0, 0,
 268         });
 269         proc_register(&proc_root, &(struct proc_dir_entry) {
 270                 PROC_MEMINFO, 7, "meminfo",
 271                 S_IFREG | S_IRUGO, 1, 0, 0,
 272         });
 273         proc_register(&proc_root, &(struct proc_dir_entry) {
 274                 PROC_KMSG, 4, "kmsg",
 275                 S_IFREG | S_IRUSR, 1, 0, 0,
 276         });
 277         proc_register(&proc_root, &(struct proc_dir_entry) {
 278                 PROC_VERSION, 7, "version",
 279                 S_IFREG | S_IRUGO, 1, 0, 0,
 280         });
 281 #ifdef CONFIG_PCI
 282         proc_register(&proc_root, &(struct proc_dir_entry) {
 283                 PROC_PCI, 3, "pci",
 284                 S_IFREG | S_IRUGO, 1, 0, 0,
 285         });
 286 #endif
 287         proc_register(&proc_root, &(struct proc_dir_entry) {
 288                 PROC_CPUINFO, 7, "cpuinfo",
 289                 S_IFREG | S_IRUGO, 1, 0, 0,
 290         });
 291         proc_register(&proc_root, &(struct proc_dir_entry) {
 292                 PROC_SELF, 4, "self",
 293                 S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO, 1, 0, 0,
 294                 64, &proc_self_inode_operations,
 295         });
 296         proc_register(&proc_root, &proc_net);
 297         proc_register(&proc_root, &proc_scsi);
 298         proc_register(&proc_root, &proc_sys_root);
 299 
 300 #ifdef CONFIG_DEBUG_MALLOC
 301         proc_register(&proc_root, &(struct proc_dir_entry) {
 302                 PROC_MALLOC, 6, "malloc",
 303                 S_IFREG | S_IRUGO, 1, 0, 0,
 304         });
 305 #endif
 306         proc_register(&proc_root, &(struct proc_dir_entry) {
 307                 PROC_KCORE, 5, "kcore",
 308                 S_IFREG | S_IRUSR, 1, 0, 0,
 309         });
 310 
 311 #ifdef CONFIG_MODULES
 312         proc_register(&proc_root, &(struct proc_dir_entry) {
 313                 PROC_MODULES, 7, "modules",
 314                 S_IFREG | S_IRUGO, 1, 0, 0,
 315         });
 316         proc_register(&proc_root, &(struct proc_dir_entry) {
 317                 PROC_KSYMS, 5, "ksyms",
 318                 S_IFREG | S_IRUGO, 1, 0, 0,
 319         });
 320 #endif
 321         proc_register(&proc_root, &(struct proc_dir_entry) {
 322                 PROC_STAT, 4, "stat",
 323                 S_IFREG | S_IRUGO, 1, 0, 0,
 324         });
 325         proc_register(&proc_root, &(struct proc_dir_entry) {
 326                 PROC_DEVICES, 7, "devices",
 327                 S_IFREG | S_IRUGO, 1, 0, 0,
 328         });
 329         proc_register(&proc_root, &(struct proc_dir_entry) {
 330                 PROC_INTERRUPTS, 10,"interrupts",
 331                 S_IFREG | S_IRUGO, 1, 0, 0,
 332         });
 333 #ifdef __SMP_PROF__
 334         proc_register(&proc_root, &(struct proc_dir_entry) {
 335                 PROC_SMP_PROF, 3,"smp",
 336                 S_IFREG | S_IRUGO, 1, 0, 0,
 337         });
 338 #endif 
 339         proc_register(&proc_root, &(struct proc_dir_entry) {
 340                 PROC_FILESYSTEMS, 11,"filesystems",
 341                 S_IFREG | S_IRUGO, 1, 0, 0,
 342         });
 343         proc_register(&proc_root, &(struct proc_dir_entry) {
 344                 PROC_DMA, 3, "dma",
 345                 S_IFREG | S_IRUGO, 1, 0, 0,
 346         });
 347         proc_register(&proc_root, &(struct proc_dir_entry) {
 348                 PROC_IOPORTS, 7, "ioports",
 349                 S_IFREG | S_IRUGO, 1, 0, 0,
 350         });
 351         proc_register(&proc_root, &(struct proc_dir_entry) {
 352                 PROC_CMDLINE, 7, "cmdline",
 353                 S_IFREG | S_IRUGO, 1, 0, 0,
 354         });
 355 
 356         proc_register( &proc_root, &(struct proc_dir_entry)
 357            { PROC_MTAB, 6, "mounts", S_IFREG | S_IRUGO, 1, 0, 0, } );
 358                    
 359         if (prof_shift) {
 360                 proc_register(&proc_root, &(struct proc_dir_entry) {
 361                         PROC_PROFILE, 7, "profile",
 362                         S_IFREG | S_IRUGO | S_IWUSR, 1, 0, 0,
 363                 });
 364         }
 365 }
 366 
 367 
 368 int proc_match(int len,const char * name,struct proc_dir_entry * de)
     /*  */
 369 {
 370         if (!de || !de->low_ino)
 371                 return 0;
 372         /* "" means "." ---> so paths like "/usr/lib//libc.a" work */
 373         if (!len && (de->name[0]=='.') && (de->name[1]=='\0'))
 374                 return 1;
 375         if (de->namelen != len)
 376                 return 0;
 377         return !memcmp(name, de->name, len);
 378 }
 379 
 380 int proc_lookup(struct inode * dir,const char * name, int len,
     /*  */
 381         struct inode ** result)
 382 {
 383         struct proc_dir_entry * de;
 384         int ino;
 385 
 386         *result = NULL;
 387         if (!dir || !S_ISDIR(dir->i_mode)) {
 388                 iput(dir);
 389                 return -ENOTDIR;
 390         }
 391 
 392         de = (struct proc_dir_entry *) dir->u.generic_ip;
 393         if (!de) {
 394                 iput(dir);
 395                 return -EINVAL;
 396         }
 397 
 398         /* Special case "." and "..": they aren't on the directory list */
 399         *result = dir;
 400         if (!len)
 401                 return 0;
 402         if (name[0] == '.') {
 403                 if (len == 1)
 404                         return 0;
 405                 if (name[1] == '.' && len == 2) {
 406                         struct inode * inode;
 407                         inode = proc_get_inode(dir->i_sb, de->parent->low_ino, de->parent);
 408                         iput(dir);
 409                         if (!inode)
 410                                 return -EINVAL;
 411                         *result = inode;
 412                         return 0;
 413                 }
 414         }
 415 
 416         *result = NULL;
 417         for (de = de->subdir; de ; de = de->next) {
 418                 if (proc_match(len, name, de))
 419                         break;
 420         }
 421         if (!de) {
 422                 iput(dir);
 423                 return -ENOENT;
 424         }
 425 
 426         ino = de->low_ino | (dir->i_ino & ~(0xffff));
 427 
 428         if (!(*result = proc_get_inode(dir->i_sb, ino, de))) {
 429                 iput(dir);
 430                 return -EINVAL;
 431         }
 432         iput(dir);
 433         return 0;
 434 }
 435 
 436 static int proc_root_lookup(struct inode * dir,const char * name, int len,
     /*  */
 437         struct inode ** result)
 438 {
 439         unsigned int pid, c;
 440         int i, ino, retval;
 441 
 442         dir->i_count++;
 443         retval = proc_lookup(dir, name, len, result);
 444         if (retval != -ENOENT) {
 445                 iput(dir);
 446                 return retval;
 447         }
 448         
 449         pid = 0;
 450         while (len-- > 0) {
 451                 c = *name - '0';
 452                 name++;
 453                 if (c > 9) {
 454                         pid = 0;
 455                         break;
 456                 }
 457                 pid *= 10;
 458                 pid += c;
 459                 if (pid & 0xffff0000) {
 460                         pid = 0;
 461                         break;
 462                 }
 463         }
 464         for (i = 0 ; i < NR_TASKS ; i++)
 465                 if (task[i] && task[i]->pid == pid)
 466                         break;
 467         if (!pid || i >= NR_TASKS) {
 468                 iput(dir);
 469                 return -ENOENT;
 470         }
 471         ino = (pid << 16) + PROC_PID_INO;
 472         if (!(*result = proc_get_inode(dir->i_sb, ino, &proc_pid))) {
 473                 iput(dir);
 474                 return -EINVAL;
 475         }
 476         iput(dir);
 477         return 0;
 478 }
 479 
 480 /*
 481  * This returns non-zero if at EOF, so that the /proc
 482  * root directory can use this and check if it should
 483  * continue with the <pid> entries..
 484  *
 485  * Note that the VFS-layer doesn't care about the return
 486  * value of the readdir() call, as long as it's non-negative
 487  * for success..
 488  */
 489 int proc_readdir(struct inode * inode, struct file * filp,
     /*  */
 490         void * dirent, filldir_t filldir)
 491 {
 492         struct proc_dir_entry * de;
 493         unsigned int ino;
 494         int i;
 495 
 496         if (!inode || !S_ISDIR(inode->i_mode))
 497                 return -ENOTDIR;
 498         ino = inode->i_ino;
 499         de = (struct proc_dir_entry *) inode->u.generic_ip;
 500         if (!de)
 501                 return -EINVAL;
 502         i = filp->f_pos;
 503         switch (i) {
 504                 case 0:
 505                         if (filldir(dirent, ".", 1, i, ino) < 0)
 506                                 return 0;
 507                         i++;
 508                         filp->f_pos++;
 509                         /* fall through */
 510                 case 1:
 511                         if (filldir(dirent, "..", 2, i, de->parent->low_ino) < 0)
 512                                 return 0;
 513                         i++;
 514                         filp->f_pos++;
 515                         /* fall through */
 516                 default:
 517                         ino &= ~0xffff;
 518                         de = de->subdir;
 519                         i -= 2;
 520                         for (;;) {
 521                                 if (!de)
 522                                         return 1;
 523                                 if (!i)
 524                                         break;
 525                                 de = de->next;
 526                                 i--;
 527                         }
 528 
 529                         do {
 530                                 if (filldir(dirent, de->name, de->namelen, filp->f_pos, ino | de->low_ino) < 0)
 531                                         return 0;
 532                                 filp->f_pos++;
 533                                 de = de->next;
 534                         } while (de);
 535         }
 536         return 1;
 537 }
 538 
 539 #define NUMBUF 10
 540 
 541 static int proc_root_readdir(struct inode * inode, struct file * filp,
     /*  */
 542         void * dirent, filldir_t filldir)
 543 {
 544         char buf[NUMBUF];
 545         unsigned int nr,pid;
 546         unsigned long i,j;
 547 
 548         nr = filp->f_pos;
 549         if (nr < FIRST_PROCESS_ENTRY) {
 550                 int error = proc_readdir(inode, filp, dirent, filldir);
 551                 if (error <= 0)
 552                         return error;
 553                 filp->f_pos = nr = FIRST_PROCESS_ENTRY;
 554         }
 555 
 556         for (nr -= FIRST_PROCESS_ENTRY; nr < NR_TASKS; nr++, filp->f_pos++) {
 557                 struct task_struct * p = task[nr];
 558 
 559                 if (!p || !(pid = p->pid))
 560                         continue;
 561 
 562                 j = NUMBUF;
 563                 i = pid;
 564                 do {
 565                         j--;
 566                         buf[j] = '0' + (i % 10);
 567                         i /= 10;
 568                 } while (i);
 569 
 570                 if (filldir(dirent, buf+j, NUMBUF-j, filp->f_pos, (pid << 16) + PROC_PID_INO) < 0)
 571                         break;
 572         }
 573         return 0;
 574 }
/* */
root/fs/proc/root.c

DEFINITIONS
