1 /* 2 * proc/fs/generic.c --- generic routines for the proc-fs 3 * 4 * This file contains generic proc-fs routines for handling 5 * directories and files. 6 * 7 * Copyright (C) 1991, 1992 Linus Torvalds. 8 * Copyright (C) 1997 Theodore Ts'o 9 */ 10 11 #include <linux/errno.h> 12 #include <linux/time.h> 13 #include <linux/proc_fs.h> 14 #include <linux/stat.h> 15 #include <linux/module.h> 16 #include <linux/mount.h> 17 #include <linux/init.h> 18 #include <linux/idr.h> 19 #include <linux/namei.h> 20 #include <linux/bitops.h> 21 #include <linux/spinlock.h> 22 #include <linux/completion.h> 23 #include <asm/uaccess.h> 24 25 #include "internal.h" 26 27 DEFINE_SPINLOCK(proc_subdir_lock); 28 29 static int proc_match(int len, const char *name, struct proc_dir_entry *de) 30 { 31 if (de->namelen != len) 32 return 0; 33 return !memcmp(name, de->name, len); 34 } 35 36 /* buffer size is one page but our output routines use some slack for overruns */ 37 #define PROC_BLOCK_SIZE (PAGE_SIZE - 1024) 38 39 static ssize_t 40 __proc_file_read(struct file *file, char __user *buf, size_t nbytes, 41 loff_t *ppos) 42 { 43 struct inode * inode = file->f_path.dentry->d_inode; 44 char *page; 45 ssize_t retval=0; 46 int eof=0; 47 ssize_t n, count; 48 char *start; 49 struct proc_dir_entry * dp; 50 unsigned long long pos; 51 52 /* 53 * Gaah, please just use "seq_file" instead. The legacy /proc 54 * interfaces cut loff_t down to off_t for reads, and ignore 55 * the offset entirely for writes.. 56 */ 57 pos = *ppos; 58 if (pos > MAX_NON_LFS) 59 return 0; 60 if (nbytes > MAX_NON_LFS - pos) 61 nbytes = MAX_NON_LFS - pos; 62 63 dp = PDE(inode); 64 if (!(page = (char*) __get_free_page(GFP_TEMPORARY))) 65 return -ENOMEM; 66 67 while ((nbytes > 0) && !eof) { 68 count = min_t(size_t, PROC_BLOCK_SIZE, nbytes); 69 70 start = NULL; 71 if (dp->read_proc) { 72 /* 73 * How to be a proc read function 74 * ------------------------------ 75 * Prototype: 76 * int f(char *buffer, char **start, off_t offset, 77 * int count, int *peof, void *dat) 78 * 79 * Assume that the buffer is "count" bytes in size. 80 * 81 * If you know you have supplied all the data you 82 * have, set *peof. 83 * 84 * You have three ways to return data: 85 * 0) Leave *start = NULL. (This is the default.) 86 * Put the data of the requested offset at that 87 * offset within the buffer. Return the number (n) 88 * of bytes there are from the beginning of the 89 * buffer up to the last byte of data. If the 90 * number of supplied bytes (= n - offset) is 91 * greater than zero and you didn't signal eof 92 * and the reader is prepared to take more data 93 * you will be called again with the requested 94 * offset advanced by the number of bytes 95 * absorbed. This interface is useful for files 96 * no larger than the buffer. 97 * 1) Set *start = an unsigned long value less than 98 * the buffer address but greater than zero. 99 * Put the data of the requested offset at the 100 * beginning of the buffer. Return the number of 101 * bytes of data placed there. If this number is 102 * greater than zero and you didn't signal eof 103 * and the reader is prepared to take more data 104 * you will be called again with the requested 105 * offset advanced by *start. This interface is 106 * useful when you have a large file consisting 107 * of a series of blocks which you want to count 108 * and return as wholes. 109 * (Hack by Paul.Russell@rustcorp.com.au) 110 * 2) Set *start = an address within the buffer. 111 * Put the data of the requested offset at *start. 112 * Return the number of bytes of data placed there. 113 * If this number is greater than zero and you 114 * didn't signal eof and the reader is prepared to 115 * take more data you will be called again with the 116 * requested offset advanced by the number of bytes 117 * absorbed. 118 */ 119 n = dp->read_proc(page, &start, *ppos, 120 count, &eof, dp->data); 121 } else 122 break; 123 124 if (n == 0) /* end of file */ 125 break; 126 if (n < 0) { /* error */ 127 if (retval == 0) 128 retval = n; 129 break; 130 } 131 132 if (start == NULL) { 133 if (n > PAGE_SIZE) { 134 printk(KERN_ERR 135 "proc_file_read: Apparent buffer overflow!\n"); 136 n = PAGE_SIZE; 137 } 138 n -= *ppos; 139 if (n <= 0) 140 break; 141 if (n > count) 142 n = count; 143 start = page + *ppos; 144 } else if (start < page) { 145 if (n > PAGE_SIZE) { 146 printk(KERN_ERR 147 "proc_file_read: Apparent buffer overflow!\n"); 148 n = PAGE_SIZE; 149 } 150 if (n > count) { 151 /* 152 * Don't reduce n because doing so might 153 * cut off part of a data block. 154 */ 155 printk(KERN_WARNING 156 "proc_file_read: Read count exceeded\n"); 157 } 158 } else /* start >= page */ { 159 unsigned long startoff = (unsigned long)(start - page); 160 if (n > (PAGE_SIZE - startoff)) { 161 printk(KERN_ERR 162 "proc_file_read: Apparent buffer overflow!\n"); 163 n = PAGE_SIZE - startoff; 164 } 165 if (n > count) 166 n = count; 167 } 168 169 n -= copy_to_user(buf, start < page ? page : start, n); 170 if (n == 0) { 171 if (retval == 0) 172 retval = -EFAULT; 173 break; 174 } 175 176 *ppos += start < page ? (unsigned long)start : n; 177 nbytes -= n; 178 buf += n; 179 retval += n; 180 } 181 free_page((unsigned long) page); 182 return retval; 183 } 184 185 static ssize_t 186 proc_file_read(struct file *file, char __user *buf, size_t nbytes, 187 loff_t *ppos) 188 { 189 struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); 190 ssize_t rv = -EIO; 191 192 spin_lock(&pde->pde_unload_lock); 193 if (!pde->proc_fops) { 194 spin_unlock(&pde->pde_unload_lock); 195 return rv; 196 } 197 pde->pde_users++; 198 spin_unlock(&pde->pde_unload_lock); 199 200 rv = __proc_file_read(file, buf, nbytes, ppos); 201 202 pde_users_dec(pde); 203 return rv; 204 } 205 206 static ssize_t 207 proc_file_write(struct file *file, const char __user *buffer, 208 size_t count, loff_t *ppos) 209 { 210 struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode); 211 ssize_t rv = -EIO; 212 213 if (pde->write_proc) { 214 spin_lock(&pde->pde_unload_lock); 215 if (!pde->proc_fops) { 216 spin_unlock(&pde->pde_unload_lock); 217 return rv; 218 } 219 pde->pde_users++; 220 spin_unlock(&pde->pde_unload_lock); 221 222 /* FIXME: does this routine need ppos? probably... */ 223 rv = pde->write_proc(file, buffer, count, pde->data); 224 pde_users_dec(pde); 225 } 226 return rv; 227 } 228 229 230 static loff_t 231 proc_file_lseek(struct file *file, loff_t offset, int orig) 232 { 233 loff_t retval = -EINVAL; 234 switch (orig) { 235 case 1: 236 offset += file->f_pos; 237 /* fallthrough */ 238 case 0: 239 if (offset < 0 || offset > MAX_NON_LFS) 240 break; 241 file->f_pos = retval = offset; 242 } 243 return retval; 244 } 245 246 static const struct file_operations proc_file_operations = { 247 .llseek = proc_file_lseek, 248 .read = proc_file_read, 249 .write = proc_file_write, 250 }; 251 252 static int proc_notify_change(struct dentry *dentry, struct iattr *iattr) 253 { 254 struct inode *inode = dentry->d_inode; 255 struct proc_dir_entry *de = PDE(inode); 256 int error; 257 258 error = inode_change_ok(inode, iattr); 259 if (error) 260 goto out; 261 262 error = inode_setattr(inode, iattr); 263 if (error) 264 goto out; 265 266 de->uid = inode->i_uid; 267 de->gid = inode->i_gid; 268 de->mode = inode->i_mode; 269 out: 270 return error; 271 } 272 273 static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry, 274 struct kstat *stat) 275 { 276 struct inode *inode = dentry->d_inode; 277 struct proc_dir_entry *de = PROC_I(inode)->pde; 278 if (de && de->nlink) 279 inode->i_nlink = de->nlink; 280 281 generic_fillattr(inode, stat); 282 return 0; 283 } 284 285 static const struct inode_operations proc_file_inode_operations = { 286 .setattr = proc_notify_change, 287 }; 288 289 /* 290 * This function parses a name such as "tty/driver/serial", and 291 * returns the struct proc_dir_entry for "/proc/tty/driver", and 292 * returns "serial" in residual. 293 */ 294 static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret, 295 const char **residual) 296 { 297 const char *cp = name, *next; 298 struct proc_dir_entry *de; 299 int len; 300 301 de = *ret; 302 if (!de) 303 de = &proc_root; 304 305 while (1) { 306 next = strchr(cp, '/'); 307 if (!next) 308 break; 309 310 len = next - cp; 311 for (de = de->subdir; de ; de = de->next) { 312 if (proc_match(len, cp, de)) 313 break; 314 } 315 if (!de) { 316 WARN(1, "name '%s'\n", name); 317 return -ENOENT; 318 } 319 cp += len + 1; 320 } 321 *residual = cp; 322 *ret = de; 323 return 0; 324 } 325 326 static int xlate_proc_name(const char *name, struct proc_dir_entry **ret, 327 const char **residual) 328 { 329 int rv; 330 331 spin_lock(&proc_subdir_lock); 332 rv = __xlate_proc_name(name, ret, residual); 333 spin_unlock(&proc_subdir_lock); 334 return rv; 335 } 336 337 static DEFINE_IDA(proc_inum_ida); 338 static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */ 339 340 #define PROC_DYNAMIC_FIRST 0xF0000000U 341 342 /* 343 * Return an inode number between PROC_DYNAMIC_FIRST and 344 * 0xffffffff, or zero on failure. 345 * 346 * Current inode allocations in the proc-fs (hex-numbers): 347 * 348 * 00000000 reserved 349 * 00000001-00000fff static entries (goners) 350 * 001 root-ino 351 * 352 * 00001000-00001fff unused 353 * 0001xxxx-7fffxxxx pid-dir entries for pid 1-7fff 354 * 80000000-efffffff unused 355 * f0000000-ffffffff dynamic entries 356 * 357 * Goal: 358 * Once we split the thing into several virtual filesystems, 359 * we will get rid of magical ranges (and this comment, BTW). 360 */ 361 static unsigned int get_inode_number(void) 362 { 363 unsigned int i; 364 int error; 365 366 retry: 367 if (ida_pre_get(&proc_inum_ida, GFP_KERNEL) == 0) 368 return 0; 369 370 spin_lock(&proc_inum_lock); 371 error = ida_get_new(&proc_inum_ida, &i); 372 spin_unlock(&proc_inum_lock); 373 if (error == -EAGAIN) 374 goto retry; 375 else if (error) 376 return 0; 377 378 if (i > UINT_MAX - PROC_DYNAMIC_FIRST) { 379 spin_lock(&proc_inum_lock); 380 ida_remove(&proc_inum_ida, i); 381 spin_unlock(&proc_inum_lock); 382 return 0; 383 } 384 return PROC_DYNAMIC_FIRST + i; 385 } 386 387 static void release_inode_number(unsigned int inum) 388 { 389 spin_lock(&proc_inum_lock); 390 ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST); 391 spin_unlock(&proc_inum_lock); 392 } 393 394 static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd) 395 { 396 nd_set_link(nd, PDE(dentry->d_inode)->data); 397 return NULL; 398 } 399 400 static const struct inode_operations proc_link_inode_operations = { 401 .readlink = generic_readlink, 402 .follow_link = proc_follow_link, 403 }; 404 405 /* 406 * As some entries in /proc are volatile, we want to 407 * get rid of unused dentries. This could be made 408 * smarter: we could keep a "volatile" flag in the 409 * inode to indicate which ones to keep. 410 */ 411 static int proc_delete_dentry(struct dentry * dentry) 412 { 413 return 1; 414 } 415 416 static const struct dentry_operations proc_dentry_operations = 417 { 418 .d_delete = proc_delete_dentry, 419 }; 420 421 /* 422 * Don't create negative dentries here, return -ENOENT by hand 423 * instead. 424 */ 425 struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir, 426 struct dentry *dentry) 427 { 428 struct inode *inode = NULL; 429 int error = -ENOENT; 430 431 spin_lock(&proc_subdir_lock); 432 for (de = de->subdir; de ; de = de->next) { 433 if (de->namelen != dentry->d_name.len) 434 continue; 435 if (!memcmp(dentry->d_name.name, de->name, de->namelen)) { 436 unsigned int ino; 437 438 ino = de->low_ino; 439 pde_get(de); 440 spin_unlock(&proc_subdir_lock); 441 error = -EINVAL; 442 inode = proc_get_inode(dir->i_sb, ino, de); 443 goto out_unlock; 444 } 445 } 446 spin_unlock(&proc_subdir_lock); 447 out_unlock: 448 449 if (inode) { 450 dentry->d_op = &proc_dentry_operations; 451 d_add(dentry, inode); 452 return NULL; 453 } 454 if (de) 455 pde_put(de); 456 return ERR_PTR(error); 457 } 458 459 struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry, 460 struct nameidata *nd) 461 { 462 return proc_lookup_de(PDE(dir), dir, dentry); 463 } 464 465 /* 466 * This returns non-zero if at EOF, so that the /proc 467 * root directory can use this and check if it should 468 * continue with the <pid> entries.. 469 * 470 * Note that the VFS-layer doesn't care about the return 471 * value of the readdir() call, as long as it's non-negative 472 * for success.. 473 */ 474 int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent, 475 filldir_t filldir) 476 { 477 unsigned int ino; 478 int i; 479 struct inode *inode = filp->f_path.dentry->d_inode; 480 int ret = 0; 481 482 ino = inode->i_ino; 483 i = filp->f_pos; 484 switch (i) { 485 case 0: 486 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) 487 goto out; 488 i++; 489 filp->f_pos++; 490 /* fall through */ 491 case 1: 492 if (filldir(dirent, "..", 2, i, 493 parent_ino(filp->f_path.dentry), 494 DT_DIR) < 0) 495 goto out; 496 i++; 497 filp->f_pos++; 498 /* fall through */ 499 default: 500 spin_lock(&proc_subdir_lock); 501 de = de->subdir; 502 i -= 2; 503 for (;;) { 504 if (!de) { 505 ret = 1; 506 spin_unlock(&proc_subdir_lock); 507 goto out; 508 } 509 if (!i) 510 break; 511 de = de->next; 512 i--; 513 } 514 515 do { 516 struct proc_dir_entry *next; 517 518 /* filldir passes info to user space */ 519 pde_get(de); 520 spin_unlock(&proc_subdir_lock); 521 if (filldir(dirent, de->name, de->namelen, filp->f_pos, 522 de->low_ino, de->mode >> 12) < 0) { 523 pde_put(de); 524 goto out; 525 } 526 spin_lock(&proc_subdir_lock); 527 filp->f_pos++; 528 next = de->next; 529 pde_put(de); 530 de = next; 531 } while (de); 532 spin_unlock(&proc_subdir_lock); 533 } 534 ret = 1; 535 out: 536 return ret; 537 } 538 539 int proc_readdir(struct file *filp, void *dirent, filldir_t filldir) 540 { 541 struct inode *inode = filp->f_path.dentry->d_inode; 542 543 return proc_readdir_de(PDE(inode), filp, dirent, filldir); 544 } 545 546 /* 547 * These are the generic /proc directory operations. They 548 * use the in-memory "struct proc_dir_entry" tree to parse 549 * the /proc directory. 550 */ 551 static const struct file_operations proc_dir_operations = { 552 .llseek = generic_file_llseek, 553 .read = generic_read_dir, 554 .readdir = proc_readdir, 555 }; 556 557 /* 558 * proc directories can do almost nothing.. 559 */ 560 static const struct inode_operations proc_dir_inode_operations = { 561 .lookup = proc_lookup, 562 .getattr = proc_getattr, 563 .setattr = proc_notify_change, 564 }; 565 566 static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp) 567 { 568 unsigned int i; 569 struct proc_dir_entry *tmp; 570 571 i = get_inode_number(); 572 if (i == 0) 573 return -EAGAIN; 574 dp->low_ino = i; 575 576 if (S_ISDIR(dp->mode)) { 577 if (dp->proc_iops == NULL) { 578 dp->proc_fops = &proc_dir_operations; 579 dp->proc_iops = &proc_dir_inode_operations; 580 } 581 dir->nlink++; 582 } else if (S_ISLNK(dp->mode)) { 583 if (dp->proc_iops == NULL) 584 dp->proc_iops = &proc_link_inode_operations; 585 } else if (S_ISREG(dp->mode)) { 586 if (dp->proc_fops == NULL) 587 dp->proc_fops = &proc_file_operations; 588 if (dp->proc_iops == NULL) 589 dp->proc_iops = &proc_file_inode_operations; 590 } 591 592 spin_lock(&proc_subdir_lock); 593 594 for (tmp = dir->subdir; tmp; tmp = tmp->next) 595 if (strcmp(tmp->name, dp->name) == 0) { 596 WARN(1, KERN_WARNING "proc_dir_entry '%s/%s' already registered\n", 597 dir->name, dp->name); 598 break; 599 } 600 601 dp->next = dir->subdir; 602 dp->parent = dir; 603 dir->subdir = dp; 604 spin_unlock(&proc_subdir_lock); 605 606 return 0; 607 } 608 609 static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, 610 const char *name, 611 mode_t mode, 612 nlink_t nlink) 613 { 614 struct proc_dir_entry *ent = NULL; 615 const char *fn = name; 616 int len; 617 618 /* make sure name is valid */ 619 if (!name || !strlen(name)) goto out; 620 621 if (xlate_proc_name(name, parent, &fn) != 0) 622 goto out; 623 624 /* At this point there must not be any '/' characters beyond *fn */ 625 if (strchr(fn, '/')) 626 goto out; 627 628 len = strlen(fn); 629 630 ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); 631 if (!ent) goto out; 632 633 memset(ent, 0, sizeof(struct proc_dir_entry)); 634 memcpy(((char *) ent) + sizeof(struct proc_dir_entry), fn, len + 1); 635 ent->name = ((char *) ent) + sizeof(*ent); 636 ent->namelen = len; 637 ent->mode = mode; 638 ent->nlink = nlink; 639 atomic_set(&ent->count, 1); 640 ent->pde_users = 0; 641 spin_lock_init(&ent->pde_unload_lock); 642 ent->pde_unload_completion = NULL; 643 INIT_LIST_HEAD(&ent->pde_openers); 644 out: 645 return ent; 646 } 647 648 struct proc_dir_entry *proc_symlink(const char *name, 649 struct proc_dir_entry *parent, const char *dest) 650 { 651 struct proc_dir_entry *ent; 652 653 ent = __proc_create(&parent, name, 654 (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1); 655 656 if (ent) { 657 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL); 658 if (ent->data) { 659 strcpy((char*)ent->data,dest); 660 if (proc_register(parent, ent) < 0) { 661 kfree(ent->data); 662 kfree(ent); 663 ent = NULL; 664 } 665 } else { 666 kfree(ent); 667 ent = NULL; 668 } 669 } 670 return ent; 671 } 672 EXPORT_SYMBOL(proc_symlink); 673 674 struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode, 675 struct proc_dir_entry *parent) 676 { 677 struct proc_dir_entry *ent; 678 679 ent = __proc_create(&parent, name, S_IFDIR | mode, 2); 680 if (ent) { 681 if (proc_register(parent, ent) < 0) { 682 kfree(ent); 683 ent = NULL; 684 } 685 } 686 return ent; 687 } 688 689 struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name, 690 struct proc_dir_entry *parent) 691 { 692 struct proc_dir_entry *ent; 693 694 ent = __proc_create(&parent, name, S_IFDIR | S_IRUGO | S_IXUGO, 2); 695 if (ent) { 696 ent->data = net; 697 if (proc_register(parent, ent) < 0) { 698 kfree(ent); 699 ent = NULL; 700 } 701 } 702 return ent; 703 } 704 EXPORT_SYMBOL_GPL(proc_net_mkdir); 705 706 struct proc_dir_entry *proc_mkdir(const char *name, 707 struct proc_dir_entry *parent) 708 { 709 return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent); 710 } 711 EXPORT_SYMBOL(proc_mkdir); 712 713 struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode, 714 struct proc_dir_entry *parent) 715 { 716 struct proc_dir_entry *ent; 717 nlink_t nlink; 718 719 if (S_ISDIR(mode)) { 720 if ((mode & S_IALLUGO) == 0) 721 mode |= S_IRUGO | S_IXUGO; 722 nlink = 2; 723 } else { 724 if ((mode & S_IFMT) == 0) 725 mode |= S_IFREG; 726 if ((mode & S_IALLUGO) == 0) 727 mode |= S_IRUGO; 728 nlink = 1; 729 } 730 731 ent = __proc_create(&parent, name, mode, nlink); 732 if (ent) { 733 if (proc_register(parent, ent) < 0) { 734 kfree(ent); 735 ent = NULL; 736 } 737 } 738 return ent; 739 } 740 EXPORT_SYMBOL(create_proc_entry); 741 742 struct proc_dir_entry *proc_create_data(const char *name, mode_t mode, 743 struct proc_dir_entry *parent, 744 const struct file_operations *proc_fops, 745 void *data) 746 { 747 struct proc_dir_entry *pde; 748 nlink_t nlink; 749 750 if (S_ISDIR(mode)) { 751 if ((mode & S_IALLUGO) == 0) 752 mode |= S_IRUGO | S_IXUGO; 753 nlink = 2; 754 } else { 755 if ((mode & S_IFMT) == 0) 756 mode |= S_IFREG; 757 if ((mode & S_IALLUGO) == 0) 758 mode |= S_IRUGO; 759 nlink = 1; 760 } 761 762 pde = __proc_create(&parent, name, mode, nlink); 763 if (!pde) 764 goto out; 765 pde->proc_fops = proc_fops; 766 pde->data = data; 767 if (proc_register(parent, pde) < 0) 768 goto out_free; 769 return pde; 770 out_free: 771 kfree(pde); 772 out: 773 return NULL; 774 } 775 EXPORT_SYMBOL(proc_create_data); 776 777 static void free_proc_entry(struct proc_dir_entry *de) 778 { 779 unsigned int ino = de->low_ino; 780 781 if (ino < PROC_DYNAMIC_FIRST) 782 return; 783 784 release_inode_number(ino); 785 786 if (S_ISLNK(de->mode)) 787 kfree(de->data); 788 kfree(de); 789 } 790 791 void pde_put(struct proc_dir_entry *pde) 792 { 793 if (atomic_dec_and_test(&pde->count)) 794 free_proc_entry(pde); 795 } 796 797 /* 798 * Remove a /proc entry and free it if it's not currently in use. 799 */ 800 void remove_proc_entry(const char *name, struct proc_dir_entry *parent) 801 { 802 struct proc_dir_entry **p; 803 struct proc_dir_entry *de = NULL; 804 const char *fn = name; 805 int len; 806 807 spin_lock(&proc_subdir_lock); 808 if (__xlate_proc_name(name, &parent, &fn) != 0) { 809 spin_unlock(&proc_subdir_lock); 810 return; 811 } 812 len = strlen(fn); 813 814 for (p = &parent->subdir; *p; p=&(*p)->next ) { 815 if (proc_match(len, fn, *p)) { 816 de = *p; 817 *p = de->next; 818 de->next = NULL; 819 break; 820 } 821 } 822 spin_unlock(&proc_subdir_lock); 823 if (!de) { 824 WARN(1, "name '%s'\n", name); 825 return; 826 } 827 828 spin_lock(&de->pde_unload_lock); 829 /* 830 * Stop accepting new callers into module. If you're 831 * dynamically allocating ->proc_fops, save a pointer somewhere. 832 */ 833 de->proc_fops = NULL; 834 /* Wait until all existing callers into module are done. */ 835 if (de->pde_users > 0) { 836 DECLARE_COMPLETION_ONSTACK(c); 837 838 if (!de->pde_unload_completion) 839 de->pde_unload_completion = &c; 840 841 spin_unlock(&de->pde_unload_lock); 842 843 wait_for_completion(de->pde_unload_completion); 844 845 goto continue_removing; 846 } 847 spin_unlock(&de->pde_unload_lock); 848 849 continue_removing: 850 spin_lock(&de->pde_unload_lock); 851 while (!list_empty(&de->pde_openers)) { 852 struct pde_opener *pdeo; 853 854 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh); 855 list_del(&pdeo->lh); 856 spin_unlock(&de->pde_unload_lock); 857 pdeo->release(pdeo->inode, pdeo->file); 858 kfree(pdeo); 859 spin_lock(&de->pde_unload_lock); 860 } 861 spin_unlock(&de->pde_unload_lock); 862 863 if (S_ISDIR(de->mode)) 864 parent->nlink--; 865 de->nlink = 0; 866 WARN(de->subdir, KERN_WARNING "%s: removing non-empty directory " 867 "'%s/%s', leaking at least '%s'\n", __func__, 868 de->parent->name, de->name, de->subdir->name); 869 pde_put(de); 870 } 871 EXPORT_SYMBOL(remove_proc_entry); 872