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

DEFINITIONS
