1 /* 2 * linux/fs/nfs/dir.c 3 * 4 * Copyright (C) 1992 Rick Sladkey 5 * 6 * nfs directory handling functions 7 * 8 * 10 Apr 1996 Added silly rename for unlink --okir 9 * 28 Sep 1996 Improved directory cache --okir 10 * 23 Aug 1997 Claus Heine claus@momo.math.rwth-aachen.de 11 * Re-implemented silly rename for unlink, newly implemented 12 * silly rename for nfs_rename() following the suggestions 13 * of Olaf Kirch (okir) found in this file. 14 * Following Linus comments on my original hack, this version 15 * depends only on the dcache stuff and doesn't touch the inode 16 * layer (iput() and friends). 17 * 6 Jun 1999 Cache readdir lookups in the page cache. -DaveM 18 */ 19 20 #include <linux/time.h> 21 #include <linux/errno.h> 22 #include <linux/stat.h> 23 #include <linux/fcntl.h> 24 #include <linux/string.h> 25 #include <linux/kernel.h> 26 #include <linux/slab.h> 27 #include <linux/mm.h> 28 #include <linux/sunrpc/clnt.h> 29 #include <linux/nfs_fs.h> 30 #include <linux/nfs_mount.h> 31 #include <linux/pagemap.h> 32 #include <linux/smp_lock.h> 33 #include <linux/pagevec.h> 34 #include <linux/namei.h> 35 #include <linux/mount.h> 36 37 #include "nfs4_fs.h" 38 #include "delegation.h" 39 #include "iostat.h" 40 41 /* #define NFS_DEBUG_VERBOSE 1 */ 42 43 static int nfs_opendir(struct inode *, struct file *); 44 static int nfs_readdir(struct file *, void *, filldir_t); 45 static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *); 46 static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *); 47 static int nfs_mkdir(struct inode *, struct dentry *, int); 48 static int nfs_rmdir(struct inode *, struct dentry *); 49 static int nfs_unlink(struct inode *, struct dentry *); 50 static int nfs_symlink(struct inode *, struct dentry *, const char *); 51 static int nfs_link(struct dentry *, struct inode *, struct dentry *); 52 static int nfs_mknod(struct inode *, struct dentry *, int, dev_t); 53 static int nfs_rename(struct inode *, struct dentry *, 54 struct inode *, struct dentry *); 55 static int nfs_fsync_dir(struct file *, struct dentry *, int); 56 static loff_t nfs_llseek_dir(struct file *, loff_t, int); 57 58 const struct file_operations nfs_dir_operations = { 59 .llseek = nfs_llseek_dir, 60 .read = generic_read_dir, 61 .readdir = nfs_readdir, 62 .open = nfs_opendir, 63 .release = nfs_release, 64 .fsync = nfs_fsync_dir, 65 }; 66 67 const struct inode_operations nfs_dir_inode_operations = { 68 .create = nfs_create, 69 .lookup = nfs_lookup, 70 .link = nfs_link, 71 .unlink = nfs_unlink, 72 .symlink = nfs_symlink, 73 .mkdir = nfs_mkdir, 74 .rmdir = nfs_rmdir, 75 .mknod = nfs_mknod, 76 .rename = nfs_rename, 77 .permission = nfs_permission, 78 .getattr = nfs_getattr, 79 .setattr = nfs_setattr, 80 }; 81 82 #ifdef CONFIG_NFS_V3 83 const struct inode_operations nfs3_dir_inode_operations = { 84 .create = nfs_create, 85 .lookup = nfs_lookup, 86 .link = nfs_link, 87 .unlink = nfs_unlink, 88 .symlink = nfs_symlink, 89 .mkdir = nfs_mkdir, 90 .rmdir = nfs_rmdir, 91 .mknod = nfs_mknod, 92 .rename = nfs_rename, 93 .permission = nfs_permission, 94 .getattr = nfs_getattr, 95 .setattr = nfs_setattr, 96 .listxattr = nfs3_listxattr, 97 .getxattr = nfs3_getxattr, 98 .setxattr = nfs3_setxattr, 99 .removexattr = nfs3_removexattr, 100 }; 101 #endif /* CONFIG_NFS_V3 */ 102 103 #ifdef CONFIG_NFS_V4 104 105 static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *); 106 const struct inode_operations nfs4_dir_inode_operations = { 107 .create = nfs_create, 108 .lookup = nfs_atomic_lookup, 109 .link = nfs_link, 110 .unlink = nfs_unlink, 111 .symlink = nfs_symlink, 112 .mkdir = nfs_mkdir, 113 .rmdir = nfs_rmdir, 114 .mknod = nfs_mknod, 115 .rename = nfs_rename, 116 .permission = nfs_permission, 117 .getattr = nfs_getattr, 118 .setattr = nfs_setattr, 119 .getxattr = nfs4_getxattr, 120 .setxattr = nfs4_setxattr, 121 .listxattr = nfs4_listxattr, 122 }; 123 124 #endif /* CONFIG_NFS_V4 */ 125 126 /* 127 * Open file 128 */ 129 static int 130 nfs_opendir(struct inode *inode, struct file *filp) 131 { 132 int res; 133 134 dfprintk(VFS, "NFS: opendir(%s/%ld)\n", 135 inode->i_sb->s_id, inode->i_ino); 136 137 lock_kernel(); 138 /* Call generic open code in order to cache credentials */ 139 res = nfs_open(inode, filp); 140 unlock_kernel(); 141 return res; 142 } 143 144 typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int); 145 typedef struct { 146 struct file *file; 147 struct page *page; 148 unsigned long page_index; 149 __be32 *ptr; 150 u64 *dir_cookie; 151 loff_t current_index; 152 struct nfs_entry *entry; 153 decode_dirent_t decode; 154 int plus; 155 int error; 156 unsigned long timestamp; 157 int timestamp_valid; 158 } nfs_readdir_descriptor_t; 159 160 /* Now we cache directories properly, by stuffing the dirent 161 * data directly in the page cache. 162 * 163 * Inode invalidation due to refresh etc. takes care of 164 * _everything_, no sloppy entry flushing logic, no extraneous 165 * copying, network direct to page cache, the way it was meant 166 * to be. 167 * 168 * NOTE: Dirent information verification is done always by the 169 * page-in of the RPC reply, nowhere else, this simplies 170 * things substantially. 171 */ 172 static 173 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page) 174 { 175 struct file *file = desc->file; 176 struct inode *inode = file->f_path.dentry->d_inode; 177 struct rpc_cred *cred = nfs_file_cred(file); 178 unsigned long timestamp; 179 int error; 180 181 dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n", 182 __FUNCTION__, (long long)desc->entry->cookie, 183 page->index); 184 185 again: 186 timestamp = jiffies; 187 error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, desc->entry->cookie, page, 188 NFS_SERVER(inode)->dtsize, desc->plus); 189 if (error < 0) { 190 /* We requested READDIRPLUS, but the server doesn't grok it */ 191 if (error == -ENOTSUPP && desc->plus) { 192 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; 193 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); 194 desc->plus = 0; 195 goto again; 196 } 197 goto error; 198 } 199 desc->timestamp = timestamp; 200 desc->timestamp_valid = 1; 201 SetPageUptodate(page); 202 spin_lock(&inode->i_lock); 203 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; 204 spin_unlock(&inode->i_lock); 205 /* Ensure consistent page alignment of the data. 206 * Note: assumes we have exclusive access to this mapping either 207 * through inode->i_mutex or some other mechanism. 208 */ 209 if (page->index == 0 && invalidate_inode_pages2_range(inode->i_mapping, PAGE_CACHE_SIZE, -1) < 0) { 210 /* Should never happen */ 211 nfs_zap_mapping(inode, inode->i_mapping); 212 } 213 unlock_page(page); 214 return 0; 215 error: 216 SetPageError(page); 217 unlock_page(page); 218 nfs_zap_caches(inode); 219 desc->error = error; 220 return -EIO; 221 } 222 223 static inline 224 int dir_decode(nfs_readdir_descriptor_t *desc) 225 { 226 __be32 *p = desc->ptr; 227 p = desc->decode(p, desc->entry, desc->plus); 228 if (IS_ERR(p)) 229 return PTR_ERR(p); 230 desc->ptr = p; 231 if (desc->timestamp_valid) 232 desc->entry->fattr->time_start = desc->timestamp; 233 else 234 desc->entry->fattr->valid &= ~NFS_ATTR_FATTR; 235 return 0; 236 } 237 238 static inline 239 void dir_page_release(nfs_readdir_descriptor_t *desc) 240 { 241 kunmap(desc->page); 242 page_cache_release(desc->page); 243 desc->page = NULL; 244 desc->ptr = NULL; 245 } 246 247 /* 248 * Given a pointer to a buffer that has already been filled by a call 249 * to readdir, find the next entry with cookie '*desc->dir_cookie'. 250 * 251 * If the end of the buffer has been reached, return -EAGAIN, if not, 252 * return the offset within the buffer of the next entry to be 253 * read. 254 */ 255 static inline 256 int find_dirent(nfs_readdir_descriptor_t *desc) 257 { 258 struct nfs_entry *entry = desc->entry; 259 int loop_count = 0, 260 status; 261 262 while((status = dir_decode(desc)) == 0) { 263 dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n", 264 __FUNCTION__, (unsigned long long)entry->cookie); 265 if (entry->prev_cookie == *desc->dir_cookie) 266 break; 267 if (loop_count++ > 200) { 268 loop_count = 0; 269 schedule(); 270 } 271 } 272 return status; 273 } 274 275 /* 276 * Given a pointer to a buffer that has already been filled by a call 277 * to readdir, find the entry at offset 'desc->file->f_pos'. 278 * 279 * If the end of the buffer has been reached, return -EAGAIN, if not, 280 * return the offset within the buffer of the next entry to be 281 * read. 282 */ 283 static inline 284 int find_dirent_index(nfs_readdir_descriptor_t *desc) 285 { 286 struct nfs_entry *entry = desc->entry; 287 int loop_count = 0, 288 status; 289 290 for(;;) { 291 status = dir_decode(desc); 292 if (status) 293 break; 294 295 dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n", 296 (unsigned long long)entry->cookie, desc->current_index); 297 298 if (desc->file->f_pos == desc->current_index) { 299 *desc->dir_cookie = entry->cookie; 300 break; 301 } 302 desc->current_index++; 303 if (loop_count++ > 200) { 304 loop_count = 0; 305 schedule(); 306 } 307 } 308 return status; 309 } 310 311 /* 312 * Find the given page, and call find_dirent() or find_dirent_index in 313 * order to try to return the next entry. 314 */ 315 static inline 316 int find_dirent_page(nfs_readdir_descriptor_t *desc) 317 { 318 struct inode *inode = desc->file->f_path.dentry->d_inode; 319 struct page *page; 320 int status; 321 322 dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n", 323 __FUNCTION__, desc->page_index, 324 (long long) *desc->dir_cookie); 325 326 /* If we find the page in the page_cache, we cannot be sure 327 * how fresh the data is, so we will ignore readdir_plus attributes. 328 */ 329 desc->timestamp_valid = 0; 330 page = read_cache_page(inode->i_mapping, desc->page_index, 331 (filler_t *)nfs_readdir_filler, desc); 332 if (IS_ERR(page)) { 333 status = PTR_ERR(page); 334 goto out; 335 } 336 337 /* NOTE: Someone else may have changed the READDIRPLUS flag */ 338 desc->page = page; 339 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ 340 if (*desc->dir_cookie != 0) 341 status = find_dirent(desc); 342 else 343 status = find_dirent_index(desc); 344 if (status < 0) 345 dir_page_release(desc); 346 out: 347 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, status); 348 return status; 349 } 350 351 /* 352 * Recurse through the page cache pages, and return a 353 * filled nfs_entry structure of the next directory entry if possible. 354 * 355 * The target for the search is '*desc->dir_cookie' if non-0, 356 * 'desc->file->f_pos' otherwise 357 */ 358 static inline 359 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) 360 { 361 int loop_count = 0; 362 int res; 363 364 /* Always search-by-index from the beginning of the cache */ 365 if (*desc->dir_cookie == 0) { 366 dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n", 367 (long long)desc->file->f_pos); 368 desc->page_index = 0; 369 desc->entry->cookie = desc->entry->prev_cookie = 0; 370 desc->entry->eof = 0; 371 desc->current_index = 0; 372 } else 373 dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", 374 (unsigned long long)*desc->dir_cookie); 375 376 for (;;) { 377 res = find_dirent_page(desc); 378 if (res != -EAGAIN) 379 break; 380 /* Align to beginning of next page */ 381 desc->page_index ++; 382 if (loop_count++ > 200) { 383 loop_count = 0; 384 schedule(); 385 } 386 } 387 388 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, res); 389 return res; 390 } 391 392 static inline unsigned int dt_type(struct inode *inode) 393 { 394 return (inode->i_mode >> 12) & 15; 395 } 396 397 static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc); 398 399 /* 400 * Once we've found the start of the dirent within a page: fill 'er up... 401 */ 402 static 403 int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, 404 filldir_t filldir) 405 { 406 struct file *file = desc->file; 407 struct nfs_entry *entry = desc->entry; 408 struct dentry *dentry = NULL; 409 unsigned long fileid; 410 int loop_count = 0, 411 res; 412 413 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n", 414 (unsigned long long)entry->cookie); 415 416 for(;;) { 417 unsigned d_type = DT_UNKNOWN; 418 /* Note: entry->prev_cookie contains the cookie for 419 * retrieving the current dirent on the server */ 420 fileid = nfs_fileid_to_ino_t(entry->ino); 421 422 /* Get a dentry if we have one */ 423 if (dentry != NULL) 424 dput(dentry); 425 dentry = nfs_readdir_lookup(desc); 426 427 /* Use readdirplus info */ 428 if (dentry != NULL && dentry->d_inode != NULL) { 429 d_type = dt_type(dentry->d_inode); 430 fileid = dentry->d_inode->i_ino; 431 } 432 433 res = filldir(dirent, entry->name, entry->len, 434 file->f_pos, fileid, d_type); 435 if (res < 0) 436 break; 437 file->f_pos++; 438 *desc->dir_cookie = entry->cookie; 439 if (dir_decode(desc) != 0) { 440 desc->page_index ++; 441 break; 442 } 443 if (loop_count++ > 200) { 444 loop_count = 0; 445 schedule(); 446 } 447 } 448 dir_page_release(desc); 449 if (dentry != NULL) 450 dput(dentry); 451 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", 452 (unsigned long long)*desc->dir_cookie, res); 453 return res; 454 } 455 456 /* 457 * If we cannot find a cookie in our cache, we suspect that this is 458 * because it points to a deleted file, so we ask the server to return 459 * whatever it thinks is the next entry. We then feed this to filldir. 460 * If all goes well, we should then be able to find our way round the 461 * cache on the next call to readdir_search_pagecache(); 462 * 463 * NOTE: we cannot add the anonymous page to the pagecache because 464 * the data it contains might not be page aligned. Besides, 465 * we should already have a complete representation of the 466 * directory in the page cache by the time we get here. 467 */ 468 static inline 469 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent, 470 filldir_t filldir) 471 { 472 struct file *file = desc->file; 473 struct inode *inode = file->f_path.dentry->d_inode; 474 struct rpc_cred *cred = nfs_file_cred(file); 475 struct page *page = NULL; 476 int status; 477 unsigned long timestamp; 478 479 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n", 480 (unsigned long long)*desc->dir_cookie); 481 482 page = alloc_page(GFP_HIGHUSER); 483 if (!page) { 484 status = -ENOMEM; 485 goto out; 486 } 487 timestamp = jiffies; 488 desc->error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, *desc->dir_cookie, 489 page, 490 NFS_SERVER(inode)->dtsize, 491 desc->plus); 492 spin_lock(&inode->i_lock); 493 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; 494 spin_unlock(&inode->i_lock); 495 desc->page = page; 496 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ 497 if (desc->error >= 0) { 498 desc->timestamp = timestamp; 499 desc->timestamp_valid = 1; 500 if ((status = dir_decode(desc)) == 0) 501 desc->entry->prev_cookie = *desc->dir_cookie; 502 } else 503 status = -EIO; 504 if (status < 0) 505 goto out_release; 506 507 status = nfs_do_filldir(desc, dirent, filldir); 508 509 /* Reset read descriptor so it searches the page cache from 510 * the start upon the next call to readdir_search_pagecache() */ 511 desc->page_index = 0; 512 desc->entry->cookie = desc->entry->prev_cookie = 0; 513 desc->entry->eof = 0; 514 out: 515 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", 516 __FUNCTION__, status); 517 return status; 518 out_release: 519 dir_page_release(desc); 520 goto out; 521 } 522 523 /* The file offset position represents the dirent entry number. A 524 last cookie cache takes care of the common case of reading the 525 whole directory. 526 */ 527 static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir) 528 { 529 struct dentry *dentry = filp->f_path.dentry; 530 struct inode *inode = dentry->d_inode; 531 nfs_readdir_descriptor_t my_desc, 532 *desc = &my_desc; 533 struct nfs_entry my_entry; 534 struct nfs_fh fh; 535 struct nfs_fattr fattr; 536 long res; 537 538 dfprintk(VFS, "NFS: readdir(%s/%s) starting at cookie %Lu\n", 539 dentry->d_parent->d_name.name, dentry->d_name.name, 540 (long long)filp->f_pos); 541 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); 542 543 lock_kernel(); 544 545 res = nfs_revalidate_mapping_nolock(inode, filp->f_mapping); 546 if (res < 0) { 547 unlock_kernel(); 548 return res; 549 } 550 551 /* 552 * filp->f_pos points to the dirent entry number. 553 * *desc->dir_cookie has the cookie for the next entry. We have 554 * to either find the entry with the appropriate number or 555 * revalidate the cookie. 556 */ 557 memset(desc, 0, sizeof(*desc)); 558 559 desc->file = filp; 560 desc->dir_cookie = &((struct nfs_open_context *)filp->private_data)->dir_cookie; 561 desc->decode = NFS_PROTO(inode)->decode_dirent; 562 desc->plus = NFS_USE_READDIRPLUS(inode); 563 564 my_entry.cookie = my_entry.prev_cookie = 0; 565 my_entry.eof = 0; 566 my_entry.fh = &fh; 567 my_entry.fattr = &fattr; 568 nfs_fattr_init(&fattr); 569 desc->entry = &my_entry; 570 571 while(!desc->entry->eof) { 572 res = readdir_search_pagecache(desc); 573 574 if (res == -EBADCOOKIE) { 575 /* This means either end of directory */ 576 if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) { 577 /* Or that the server has 'lost' a cookie */ 578 res = uncached_readdir(desc, dirent, filldir); 579 if (res >= 0) 580 continue; 581 } 582 res = 0; 583 break; 584 } 585 if (res == -ETOOSMALL && desc->plus) { 586 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); 587 nfs_zap_caches(inode); 588 desc->plus = 0; 589 desc->entry->eof = 0; 590 continue; 591 } 592 if (res < 0) 593 break; 594 595 res = nfs_do_filldir(desc, dirent, filldir); 596 if (res < 0) { 597 res = 0; 598 break; 599 } 600 } 601 unlock_kernel(); 602 if (res > 0) 603 res = 0; 604 dfprintk(VFS, "NFS: readdir(%s/%s) returns %ld\n", 605 dentry->d_parent->d_name.name, dentry->d_name.name, 606 res); 607 return res; 608 } 609 610 loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin) 611 { 612 mutex_lock(&filp->f_path.dentry->d_inode->i_mutex); 613 switch (origin) { 614 case 1: 615 offset += filp->f_pos; 616 case 0: 617 if (offset >= 0) 618 break; 619 default: 620 offset = -EINVAL; 621 goto out; 622 } 623 if (offset != filp->f_pos) { 624 filp->f_pos = offset; 625 ((struct nfs_open_context *)filp->private_data)->dir_cookie = 0; 626 } 627 out: 628 mutex_unlock(&filp->f_path.dentry->d_inode->i_mutex); 629 return offset; 630 } 631 632 /* 633 * All directory operations under NFS are synchronous, so fsync() 634 * is a dummy operation. 635 */ 636 int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync) 637 { 638 dfprintk(VFS, "NFS: fsync_dir(%s/%s) datasync %d\n", 639 dentry->d_parent->d_name.name, dentry->d_name.name, 640 datasync); 641 642 return 0; 643 } 644 645 /* 646 * A check for whether or not the parent directory has changed. 647 * In the case it has, we assume that the dentries are untrustworthy 648 * and may need to be looked up again. 649 */ 650 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) 651 { 652 unsigned long verf; 653 654 if (IS_ROOT(dentry)) 655 return 1; 656 verf = (unsigned long)dentry->d_fsdata; 657 if (nfs_caches_unstable(dir) 658 || verf != NFS_I(dir)->cache_change_attribute) 659 return 0; 660 return 1; 661 } 662 663 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf) 664 { 665 dentry->d_fsdata = (void *)verf; 666 } 667 668 static void nfs_refresh_verifier(struct dentry * dentry, unsigned long verf) 669 { 670 nfs_set_verifier(dentry, verf); 671 } 672 673 /* 674 * Whenever an NFS operation succeeds, we know that the dentry 675 * is valid, so we update the revalidation timestamp. 676 */ 677 static inline void nfs_renew_times(struct dentry * dentry) 678 { 679 dentry->d_time = jiffies; 680 } 681 682 /* 683 * Return the intent data that applies to this particular path component 684 * 685 * Note that the current set of intents only apply to the very last 686 * component of the path. 687 * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT. 688 */ 689 static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask) 690 { 691 if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT)) 692 return 0; 693 return nd->flags & mask; 694 } 695 696 /* 697 * Inode and filehandle revalidation for lookups. 698 * 699 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL, 700 * or if the intent information indicates that we're about to open this 701 * particular file and the "nocto" mount flag is not set. 702 * 703 */ 704 static inline 705 int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd) 706 { 707 struct nfs_server *server = NFS_SERVER(inode); 708 709 if (nd != NULL) { 710 /* VFS wants an on-the-wire revalidation */ 711 if (nd->flags & LOOKUP_REVAL) 712 goto out_force; 713 /* This is an open(2) */ 714 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 && 715 !(server->flags & NFS_MOUNT_NOCTO) && 716 (S_ISREG(inode->i_mode) || 717 S_ISDIR(inode->i_mode))) 718 goto out_force; 719 } 720 return nfs_revalidate_inode(server, inode); 721 out_force: 722 return __nfs_revalidate_inode(server, inode); 723 } 724 725 /* 726 * We judge how long we want to trust negative 727 * dentries by looking at the parent inode mtime. 728 * 729 * If parent mtime has changed, we revalidate, else we wait for a 730 * period corresponding to the parent's attribute cache timeout value. 731 */ 732 static inline 733 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, 734 struct nameidata *nd) 735 { 736 /* Don't revalidate a negative dentry if we're creating a new file */ 737 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) 738 return 0; 739 return !nfs_check_verifier(dir, dentry); 740 } 741 742 /* 743 * This is called every time the dcache has a lookup hit, 744 * and we should check whether we can really trust that 745 * lookup. 746 * 747 * NOTE! The hit can be a negative hit too, don't assume 748 * we have an inode! 749 * 750 * If the parent directory is seen to have changed, we throw out the 751 * cached dentry and do a new lookup. 752 */ 753 static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd) 754 { 755 struct inode *dir; 756 struct inode *inode; 757 struct dentry *parent; 758 int error; 759 struct nfs_fh fhandle; 760 struct nfs_fattr fattr; 761 unsigned long verifier; 762 763 parent = dget_parent(dentry); 764 lock_kernel(); 765 dir = parent->d_inode; 766 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); 767 inode = dentry->d_inode; 768 769 /* Revalidate parent directory attribute cache */ 770 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) 771 goto out_zap_parent; 772 773 if (!inode) { 774 if (nfs_neg_need_reval(dir, dentry, nd)) 775 goto out_bad; 776 goto out_valid; 777 } 778 779 if (is_bad_inode(inode)) { 780 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n", 781 __FUNCTION__, dentry->d_parent->d_name.name, 782 dentry->d_name.name); 783 goto out_bad; 784 } 785 786 /* Force a full look up iff the parent directory has changed */ 787 if (nfs_check_verifier(dir, dentry)) { 788 if (nfs_lookup_verify_inode(inode, nd)) 789 goto out_zap_parent; 790 goto out_valid; 791 } 792 793 if (NFS_STALE(inode)) 794 goto out_bad; 795 796 verifier = nfs_save_change_attribute(dir); 797 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr); 798 if (error) 799 goto out_bad; 800 if (nfs_compare_fh(NFS_FH(inode), &fhandle)) 801 goto out_bad; 802 if ((error = nfs_refresh_inode(inode, &fattr)) != 0) 803 goto out_bad; 804 805 nfs_renew_times(dentry); 806 nfs_refresh_verifier(dentry, verifier); 807 out_valid: 808 unlock_kernel(); 809 dput(parent); 810 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n", 811 __FUNCTION__, dentry->d_parent->d_name.name, 812 dentry->d_name.name); 813 return 1; 814 out_zap_parent: 815 nfs_zap_caches(dir); 816 out_bad: 817 NFS_CACHEINV(dir); 818 if (inode && S_ISDIR(inode->i_mode)) { 819 /* Purge readdir caches. */ 820 nfs_zap_caches(inode); 821 /* If we have submounts, don't unhash ! */ 822 if (have_submounts(dentry)) 823 goto out_valid; 824 shrink_dcache_parent(dentry); 825 } 826 d_drop(dentry); 827 unlock_kernel(); 828 dput(parent); 829 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", 830 __FUNCTION__, dentry->d_parent->d_name.name, 831 dentry->d_name.name); 832 return 0; 833 } 834 835 /* 836 * This is called from dput() when d_count is going to 0. 837 */ 838 static int nfs_dentry_delete(struct dentry *dentry) 839 { 840 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", 841 dentry->d_parent->d_name.name, dentry->d_name.name, 842 dentry->d_flags); 843 844 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 845 /* Unhash it, so that ->d_iput() would be called */ 846 return 1; 847 } 848 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) { 849 /* Unhash it, so that ancestors of killed async unlink 850 * files will be cleaned up during umount */ 851 return 1; 852 } 853 return 0; 854 855 } 856 857 /* 858 * Called when the dentry loses inode. 859 * We use it to clean up silly-renamed files. 860 */ 861 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) 862 { 863 nfs_inode_return_delegation(inode); 864 if (S_ISDIR(inode->i_mode)) 865 /* drop any readdir cache as it could easily be old */ 866 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA; 867 868 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 869 lock_kernel(); 870 drop_nlink(inode); 871 nfs_complete_unlink(dentry); 872 unlock_kernel(); 873 } 874 /* When creating a negative dentry, we want to renew d_time */ 875 nfs_renew_times(dentry); 876 iput(inode); 877 } 878 879 struct dentry_operations nfs_dentry_operations = { 880 .d_revalidate = nfs_lookup_revalidate, 881 .d_delete = nfs_dentry_delete, 882 .d_iput = nfs_dentry_iput, 883 }; 884 885 /* 886 * Use intent information to check whether or not we're going to do 887 * an O_EXCL create using this path component. 888 */ 889 static inline 890 int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd) 891 { 892 if (NFS_PROTO(dir)->version == 2) 893 return 0; 894 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0) 895 return 0; 896 return (nd->intent.open.flags & O_EXCL) != 0; 897 } 898 899 static inline int nfs_reval_fsid(struct vfsmount *mnt, struct inode *dir, 900 struct nfs_fh *fh, struct nfs_fattr *fattr) 901 { 902 struct nfs_server *server = NFS_SERVER(dir); 903 904 if (!nfs_fsid_equal(&server->fsid, &fattr->fsid)) 905 /* Revalidate fsid on root dir */ 906 return __nfs_revalidate_inode(server, mnt->mnt_root->d_inode); 907 return 0; 908 } 909 910 static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 911 { 912 struct dentry *res; 913 struct inode *inode = NULL; 914 int error; 915 struct nfs_fh fhandle; 916 struct nfs_fattr fattr; 917 918 dfprintk(VFS, "NFS: lookup(%s/%s)\n", 919 dentry->d_parent->d_name.name, dentry->d_name.name); 920 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); 921 922 res = ERR_PTR(-ENAMETOOLONG); 923 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) 924 goto out; 925 926 res = ERR_PTR(-ENOMEM); 927 dentry->d_op = NFS_PROTO(dir)->dentry_ops; 928 929 lock_kernel(); 930 931 /* 932 * If we're doing an exclusive create, optimize away the lookup 933 * but don't hash the dentry. 934 */ 935 if (nfs_is_exclusive_create(dir, nd)) { 936 d_instantiate(dentry, NULL); 937 res = NULL; 938 goto out_unlock; 939 } 940 941 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr); 942 if (error == -ENOENT) 943 goto no_entry; 944 if (error < 0) { 945 res = ERR_PTR(error); 946 goto out_unlock; 947 } 948 error = nfs_reval_fsid(nd->mnt, dir, &fhandle, &fattr); 949 if (error < 0) { 950 res = ERR_PTR(error); 951 goto out_unlock; 952 } 953 inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr); 954 res = (struct dentry *)inode; 955 if (IS_ERR(res)) 956 goto out_unlock; 957 958 no_entry: 959 res = d_materialise_unique(dentry, inode); 960 if (res != NULL) { 961 struct dentry *parent; 962 if (IS_ERR(res)) 963 goto out_unlock; 964 /* Was a directory renamed! */ 965 parent = dget_parent(res); 966 if (!IS_ROOT(parent)) 967 nfs_mark_for_revalidate(parent->d_inode); 968 dput(parent); 969 dentry = res; 970 } 971 nfs_renew_times(dentry); 972 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 973 out_unlock: 974 unlock_kernel(); 975 out: 976 return res; 977 } 978 979 #ifdef CONFIG_NFS_V4 980 static int nfs_open_revalidate(struct dentry *, struct nameidata *); 981 982 struct dentry_operations nfs4_dentry_operations = { 983 .d_revalidate = nfs_open_revalidate, 984 .d_delete = nfs_dentry_delete, 985 .d_iput = nfs_dentry_iput, 986 }; 987 988 /* 989 * Use intent information to determine whether we need to substitute 990 * the NFSv4-style stateful OPEN for the LOOKUP call 991 */ 992 static int is_atomic_open(struct inode *dir, struct nameidata *nd) 993 { 994 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0) 995 return 0; 996 /* NFS does not (yet) have a stateful open for directories */ 997 if (nd->flags & LOOKUP_DIRECTORY) 998 return 0; 999 /* Are we trying to write to a read only partition? */ 1000 if (IS_RDONLY(dir) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE))) 1001 return 0; 1002 return 1; 1003 } 1004 1005 static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) 1006 { 1007 struct dentry *res = NULL; 1008 int error; 1009 1010 dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n", 1011 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1012 1013 /* Check that we are indeed trying to open this file */ 1014 if (!is_atomic_open(dir, nd)) 1015 goto no_open; 1016 1017 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) { 1018 res = ERR_PTR(-ENAMETOOLONG); 1019 goto out; 1020 } 1021 dentry->d_op = NFS_PROTO(dir)->dentry_ops; 1022 1023 /* Let vfs_create() deal with O_EXCL */ 1024 if (nd->intent.open.flags & O_EXCL) { 1025 d_add(dentry, NULL); 1026 goto out; 1027 } 1028 1029 /* Open the file on the server */ 1030 lock_kernel(); 1031 /* Revalidate parent directory attribute cache */ 1032 error = nfs_revalidate_inode(NFS_SERVER(dir), dir); 1033 if (error < 0) { 1034 res = ERR_PTR(error); 1035 unlock_kernel(); 1036 goto out; 1037 } 1038 1039 if (nd->intent.open.flags & O_CREAT) { 1040 nfs_begin_data_update(dir); 1041 res = nfs4_atomic_open(dir, dentry, nd); 1042 nfs_end_data_update(dir); 1043 } else 1044 res = nfs4_atomic_open(dir, dentry, nd); 1045 unlock_kernel(); 1046 if (IS_ERR(res)) { 1047 error = PTR_ERR(res); 1048 switch (error) { 1049 /* Make a negative dentry */ 1050 case -ENOENT: 1051 res = NULL; 1052 goto out; 1053 /* This turned out not to be a regular file */ 1054 case -EISDIR: 1055 case -ENOTDIR: 1056 goto no_open; 1057 case -ELOOP: 1058 if (!(nd->intent.open.flags & O_NOFOLLOW)) 1059 goto no_open; 1060 /* case -EINVAL: */ 1061 default: 1062 goto out; 1063 } 1064 } else if (res != NULL) 1065 dentry = res; 1066 nfs_renew_times(dentry); 1067 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1068 out: 1069 return res; 1070 no_open: 1071 return nfs_lookup(dir, dentry, nd); 1072 } 1073 1074 static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) 1075 { 1076 struct dentry *parent = NULL; 1077 struct inode *inode = dentry->d_inode; 1078 struct inode *dir; 1079 unsigned long verifier; 1080 int openflags, ret = 0; 1081 1082 parent = dget_parent(dentry); 1083 dir = parent->d_inode; 1084 if (!is_atomic_open(dir, nd)) 1085 goto no_open; 1086 /* We can't create new files in nfs_open_revalidate(), so we 1087 * optimize away revalidation of negative dentries. 1088 */ 1089 if (inode == NULL) 1090 goto out; 1091 /* NFS only supports OPEN on regular files */ 1092 if (!S_ISREG(inode->i_mode)) 1093 goto no_open; 1094 openflags = nd->intent.open.flags; 1095 /* We cannot do exclusive creation on a positive dentry */ 1096 if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) 1097 goto no_open; 1098 /* We can't create new files, or truncate existing ones here */ 1099 openflags &= ~(O_CREAT|O_TRUNC); 1100 1101 /* 1102 * Note: we're not holding inode->i_mutex and so may be racing with 1103 * operations that change the directory. We therefore save the 1104 * change attribute *before* we do the RPC call. 1105 */ 1106 lock_kernel(); 1107 verifier = nfs_save_change_attribute(dir); 1108 ret = nfs4_open_revalidate(dir, dentry, openflags, nd); 1109 if (!ret) 1110 nfs_refresh_verifier(dentry, verifier); 1111 unlock_kernel(); 1112 out: 1113 dput(parent); 1114 if (!ret) 1115 d_drop(dentry); 1116 return ret; 1117 no_open: 1118 dput(parent); 1119 if (inode != NULL && nfs_have_delegation(inode, FMODE_READ)) 1120 return 1; 1121 return nfs_lookup_revalidate(dentry, nd); 1122 } 1123 #endif /* CONFIG_NFSV4 */ 1124 1125 static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc) 1126 { 1127 struct dentry *parent = desc->file->f_path.dentry; 1128 struct inode *dir = parent->d_inode; 1129 struct nfs_entry *entry = desc->entry; 1130 struct dentry *dentry, *alias; 1131 struct qstr name = { 1132 .name = entry->name, 1133 .len = entry->len, 1134 }; 1135 struct inode *inode; 1136 1137 switch (name.len) { 1138 case 2: 1139 if (name.name[0] == '.' && name.name[1] == '.') 1140 return dget_parent(parent); 1141 break; 1142 case 1: 1143 if (name.name[0] == '.') 1144 return dget(parent); 1145 } 1146 name.hash = full_name_hash(name.name, name.len); 1147 dentry = d_lookup(parent, &name); 1148 if (dentry != NULL) { 1149 /* Is this a positive dentry that matches the readdir info? */ 1150 if (dentry->d_inode != NULL && 1151 (NFS_FILEID(dentry->d_inode) == entry->ino || 1152 d_mountpoint(dentry))) { 1153 if (!desc->plus || entry->fh->size == 0) 1154 return dentry; 1155 if (nfs_compare_fh(NFS_FH(dentry->d_inode), 1156 entry->fh) == 0) 1157 goto out_renew; 1158 } 1159 /* No, so d_drop to allow one to be created */ 1160 d_drop(dentry); 1161 dput(dentry); 1162 } 1163 if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR)) 1164 return NULL; 1165 /* Note: caller is already holding the dir->i_mutex! */ 1166 dentry = d_alloc(parent, &name); 1167 if (dentry == NULL) 1168 return NULL; 1169 dentry->d_op = NFS_PROTO(dir)->dentry_ops; 1170 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); 1171 if (IS_ERR(inode)) { 1172 dput(dentry); 1173 return NULL; 1174 } 1175 1176 alias = d_materialise_unique(dentry, inode); 1177 if (alias != NULL) { 1178 dput(dentry); 1179 if (IS_ERR(alias)) 1180 return NULL; 1181 dentry = alias; 1182 } 1183 1184 nfs_renew_times(dentry); 1185 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1186 return dentry; 1187 out_renew: 1188 nfs_renew_times(dentry); 1189 nfs_refresh_verifier(dentry, nfs_save_change_attribute(dir)); 1190 return dentry; 1191 } 1192 1193 /* 1194 * Code common to create, mkdir, and mknod. 1195 */ 1196 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, 1197 struct nfs_fattr *fattr) 1198 { 1199 struct inode *inode; 1200 int error = -EACCES; 1201 1202 /* We may have been initialized further down */ 1203 if (dentry->d_inode) 1204 return 0; 1205 if (fhandle->size == 0) { 1206 struct inode *dir = dentry->d_parent->d_inode; 1207 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr); 1208 if (error) 1209 return error; 1210 } 1211 if (!(fattr->valid & NFS_ATTR_FATTR)) { 1212 struct nfs_server *server = NFS_SB(dentry->d_sb); 1213 error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr); 1214 if (error < 0) 1215 return error; 1216 } 1217 inode = nfs_fhget(dentry->d_sb, fhandle, fattr); 1218 error = PTR_ERR(inode); 1219 if (IS_ERR(inode)) 1220 return error; 1221 d_instantiate(dentry, inode); 1222 if (d_unhashed(dentry)) 1223 d_rehash(dentry); 1224 return 0; 1225 } 1226 1227 /* 1228 * Following a failed create operation, we drop the dentry rather 1229 * than retain a negative dentry. This avoids a problem in the event 1230 * that the operation succeeded on the server, but an error in the 1231 * reply path made it appear to have failed. 1232 */ 1233 static int nfs_create(struct inode *dir, struct dentry *dentry, int mode, 1234 struct nameidata *nd) 1235 { 1236 struct iattr attr; 1237 int error; 1238 int open_flags = 0; 1239 1240 dfprintk(VFS, "NFS: create(%s/%ld), %s\n", 1241 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1242 1243 attr.ia_mode = mode; 1244 attr.ia_valid = ATTR_MODE; 1245 1246 if (nd && (nd->flags & LOOKUP_CREATE)) 1247 open_flags = nd->intent.open.flags; 1248 1249 lock_kernel(); 1250 nfs_begin_data_update(dir); 1251 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, nd); 1252 nfs_end_data_update(dir); 1253 if (error != 0) 1254 goto out_err; 1255 nfs_renew_times(dentry); 1256 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1257 unlock_kernel(); 1258 return 0; 1259 out_err: 1260 unlock_kernel(); 1261 d_drop(dentry); 1262 return error; 1263 } 1264 1265 /* 1266 * See comments for nfs_proc_create regarding failed operations. 1267 */ 1268 static int 1269 nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev) 1270 { 1271 struct iattr attr; 1272 int status; 1273 1274 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n", 1275 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1276 1277 if (!new_valid_dev(rdev)) 1278 return -EINVAL; 1279 1280 attr.ia_mode = mode; 1281 attr.ia_valid = ATTR_MODE; 1282 1283 lock_kernel(); 1284 nfs_begin_data_update(dir); 1285 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); 1286 nfs_end_data_update(dir); 1287 if (status != 0) 1288 goto out_err; 1289 nfs_renew_times(dentry); 1290 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1291 unlock_kernel(); 1292 return 0; 1293 out_err: 1294 unlock_kernel(); 1295 d_drop(dentry); 1296 return status; 1297 } 1298 1299 /* 1300 * See comments for nfs_proc_create regarding failed operations. 1301 */ 1302 static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 1303 { 1304 struct iattr attr; 1305 int error; 1306 1307 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n", 1308 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1309 1310 attr.ia_valid = ATTR_MODE; 1311 attr.ia_mode = mode | S_IFDIR; 1312 1313 lock_kernel(); 1314 nfs_begin_data_update(dir); 1315 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); 1316 nfs_end_data_update(dir); 1317 if (error != 0) 1318 goto out_err; 1319 nfs_renew_times(dentry); 1320 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1321 unlock_kernel(); 1322 return 0; 1323 out_err: 1324 d_drop(dentry); 1325 unlock_kernel(); 1326 return error; 1327 } 1328 1329 static int nfs_rmdir(struct inode *dir, struct dentry *dentry) 1330 { 1331 int error; 1332 1333 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n", 1334 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1335 1336 lock_kernel(); 1337 nfs_begin_data_update(dir); 1338 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); 1339 /* Ensure the VFS deletes this inode */ 1340 if (error == 0 && dentry->d_inode != NULL) 1341 clear_nlink(dentry->d_inode); 1342 nfs_end_data_update(dir); 1343 unlock_kernel(); 1344 1345 return error; 1346 } 1347 1348 static int nfs_sillyrename(struct inode *dir, struct dentry *dentry) 1349 { 1350 static unsigned int sillycounter; 1351 const int i_inosize = sizeof(dir->i_ino)*2; 1352 const int countersize = sizeof(sillycounter)*2; 1353 const int slen = sizeof(".nfs") + i_inosize + countersize - 1; 1354 char silly[slen+1]; 1355 struct qstr qsilly; 1356 struct dentry *sdentry; 1357 int error = -EIO; 1358 1359 dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n", 1360 dentry->d_parent->d_name.name, dentry->d_name.name, 1361 atomic_read(&dentry->d_count)); 1362 nfs_inc_stats(dir, NFSIOS_SILLYRENAME); 1363 1364 /* 1365 * We don't allow a dentry to be silly-renamed twice. 1366 */ 1367 error = -EBUSY; 1368 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) 1369 goto out; 1370 1371 sprintf(silly, ".nfs%*.*lx", 1372 i_inosize, i_inosize, dentry->d_inode->i_ino); 1373 1374 /* Return delegation in anticipation of the rename */ 1375 nfs_inode_return_delegation(dentry->d_inode); 1376 1377 sdentry = NULL; 1378 do { 1379 char *suffix = silly + slen - countersize; 1380 1381 dput(sdentry); 1382 sillycounter++; 1383 sprintf(suffix, "%*.*x", countersize, countersize, sillycounter); 1384 1385 dfprintk(VFS, "NFS: trying to rename %s to %s\n", 1386 dentry->d_name.name, silly); 1387 1388 sdentry = lookup_one_len(silly, dentry->d_parent, slen); 1389 /* 1390 * N.B. Better to return EBUSY here ... it could be 1391 * dangerous to delete the file while it's in use. 1392 */ 1393 if (IS_ERR(sdentry)) 1394 goto out; 1395 } while(sdentry->d_inode != NULL); /* need negative lookup */ 1396 1397 qsilly.name = silly; 1398 qsilly.len = strlen(silly); 1399 nfs_begin_data_update(dir); 1400 if (dentry->d_inode) { 1401 nfs_begin_data_update(dentry->d_inode); 1402 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, 1403 dir, &qsilly); 1404 nfs_mark_for_revalidate(dentry->d_inode); 1405 nfs_end_data_update(dentry->d_inode); 1406 } else 1407 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, 1408 dir, &qsilly); 1409 nfs_end_data_update(dir); 1410 if (!error) { 1411 nfs_renew_times(dentry); 1412 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1413 d_move(dentry, sdentry); 1414 error = nfs_async_unlink(dentry); 1415 /* If we return 0 we don't unlink */ 1416 } 1417 dput(sdentry); 1418 out: 1419 return error; 1420 } 1421 1422 /* 1423 * Remove a file after making sure there are no pending writes, 1424 * and after checking that the file has only one user. 1425 * 1426 * We invalidate the attribute cache and free the inode prior to the operation 1427 * to avoid possible races if the server reuses the inode. 1428 */ 1429 static int nfs_safe_remove(struct dentry *dentry) 1430 { 1431 struct inode *dir = dentry->d_parent->d_inode; 1432 struct inode *inode = dentry->d_inode; 1433 int error = -EBUSY; 1434 1435 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n", 1436 dentry->d_parent->d_name.name, dentry->d_name.name); 1437 1438 /* If the dentry was sillyrenamed, we simply call d_delete() */ 1439 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 1440 error = 0; 1441 goto out; 1442 } 1443 1444 nfs_begin_data_update(dir); 1445 if (inode != NULL) { 1446 nfs_inode_return_delegation(inode); 1447 nfs_begin_data_update(inode); 1448 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); 1449 /* The VFS may want to delete this inode */ 1450 if (error == 0) 1451 drop_nlink(inode); 1452 nfs_mark_for_revalidate(inode); 1453 nfs_end_data_update(inode); 1454 } else 1455 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); 1456 nfs_end_data_update(dir); 1457 out: 1458 return error; 1459 } 1460 1461 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode 1462 * belongs to an active ".nfs..." file and we return -EBUSY. 1463 * 1464 * If sillyrename() returns 0, we do nothing, otherwise we unlink. 1465 */ 1466 static int nfs_unlink(struct inode *dir, struct dentry *dentry) 1467 { 1468 int error; 1469 int need_rehash = 0; 1470 1471 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, 1472 dir->i_ino, dentry->d_name.name); 1473 1474 lock_kernel(); 1475 spin_lock(&dcache_lock); 1476 spin_lock(&dentry->d_lock); 1477 if (atomic_read(&dentry->d_count) > 1) { 1478 spin_unlock(&dentry->d_lock); 1479 spin_unlock(&dcache_lock); 1480 /* Start asynchronous writeout of the inode */ 1481 write_inode_now(dentry->d_inode, 0); 1482 error = nfs_sillyrename(dir, dentry); 1483 unlock_kernel(); 1484 return error; 1485 } 1486 if (!d_unhashed(dentry)) { 1487 __d_drop(dentry); 1488 need_rehash = 1; 1489 } 1490 spin_unlock(&dentry->d_lock); 1491 spin_unlock(&dcache_lock); 1492 error = nfs_safe_remove(dentry); 1493 if (!error) { 1494 nfs_renew_times(dentry); 1495 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1496 } else if (need_rehash) 1497 d_rehash(dentry); 1498 unlock_kernel(); 1499 return error; 1500 } 1501 1502 /* 1503 * To create a symbolic link, most file systems instantiate a new inode, 1504 * add a page to it containing the path, then write it out to the disk 1505 * using prepare_write/commit_write. 1506 * 1507 * Unfortunately the NFS client can't create the in-core inode first 1508 * because it needs a file handle to create an in-core inode (see 1509 * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the 1510 * symlink request has completed on the server. 1511 * 1512 * So instead we allocate a raw page, copy the symname into it, then do 1513 * the SYMLINK request with the page as the buffer. If it succeeds, we 1514 * now have a new file handle and can instantiate an in-core NFS inode 1515 * and move the raw page into its mapping. 1516 */ 1517 static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) 1518 { 1519 struct pagevec lru_pvec; 1520 struct page *page; 1521 char *kaddr; 1522 struct iattr attr; 1523 unsigned int pathlen = strlen(symname); 1524 int error; 1525 1526 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id, 1527 dir->i_ino, dentry->d_name.name, symname); 1528 1529 if (pathlen > PAGE_SIZE) 1530 return -ENAMETOOLONG; 1531 1532 attr.ia_mode = S_IFLNK | S_IRWXUGO; 1533 attr.ia_valid = ATTR_MODE; 1534 1535 lock_kernel(); 1536 1537 page = alloc_page(GFP_KERNEL); 1538 if (!page) { 1539 unlock_kernel(); 1540 return -ENOMEM; 1541 } 1542 1543 kaddr = kmap_atomic(page, KM_USER0); 1544 memcpy(kaddr, symname, pathlen); 1545 if (pathlen < PAGE_SIZE) 1546 memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); 1547 kunmap_atomic(kaddr, KM_USER0); 1548 1549 nfs_begin_data_update(dir); 1550 error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); 1551 nfs_end_data_update(dir); 1552 if (error != 0) { 1553 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n", 1554 dir->i_sb->s_id, dir->i_ino, 1555 dentry->d_name.name, symname, error); 1556 d_drop(dentry); 1557 __free_page(page); 1558 unlock_kernel(); 1559 return error; 1560 } 1561 1562 /* 1563 * No big deal if we can't add this page to the page cache here. 1564 * READLINK will get the missing page from the server if needed. 1565 */ 1566 pagevec_init(&lru_pvec, 0); 1567 if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0, 1568 GFP_KERNEL)) { 1569 pagevec_add(&lru_pvec, page); 1570 pagevec_lru_add(&lru_pvec); 1571 SetPageUptodate(page); 1572 unlock_page(page); 1573 } else 1574 __free_page(page); 1575 1576 unlock_kernel(); 1577 return 0; 1578 } 1579 1580 static int 1581 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) 1582 { 1583 struct inode *inode = old_dentry->d_inode; 1584 int error; 1585 1586 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n", 1587 old_dentry->d_parent->d_name.name, old_dentry->d_name.name, 1588 dentry->d_parent->d_name.name, dentry->d_name.name); 1589 1590 lock_kernel(); 1591 nfs_begin_data_update(dir); 1592 nfs_begin_data_update(inode); 1593 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); 1594 if (error == 0) { 1595 atomic_inc(&inode->i_count); 1596 d_instantiate(dentry, inode); 1597 } 1598 nfs_end_data_update(inode); 1599 nfs_end_data_update(dir); 1600 unlock_kernel(); 1601 return error; 1602 } 1603 1604 /* 1605 * RENAME 1606 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a 1607 * different file handle for the same inode after a rename (e.g. when 1608 * moving to a different directory). A fail-safe method to do so would 1609 * be to look up old_dir/old_name, create a link to new_dir/new_name and 1610 * rename the old file using the sillyrename stuff. This way, the original 1611 * file in old_dir will go away when the last process iput()s the inode. 1612 * 1613 * FIXED. 1614 * 1615 * It actually works quite well. One needs to have the possibility for 1616 * at least one ".nfs..." file in each directory the file ever gets 1617 * moved or linked to which happens automagically with the new 1618 * implementation that only depends on the dcache stuff instead of 1619 * using the inode layer 1620 * 1621 * Unfortunately, things are a little more complicated than indicated 1622 * above. For a cross-directory move, we want to make sure we can get 1623 * rid of the old inode after the operation. This means there must be 1624 * no pending writes (if it's a file), and the use count must be 1. 1625 * If these conditions are met, we can drop the dentries before doing 1626 * the rename. 1627 */ 1628 static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, 1629 struct inode *new_dir, struct dentry *new_dentry) 1630 { 1631 struct inode *old_inode = old_dentry->d_inode; 1632 struct inode *new_inode = new_dentry->d_inode; 1633 struct dentry *dentry = NULL, *rehash = NULL; 1634 int error = -EBUSY; 1635 1636 /* 1637 * To prevent any new references to the target during the rename, 1638 * we unhash the dentry and free the inode in advance. 1639 */ 1640 lock_kernel(); 1641 if (!d_unhashed(new_dentry)) { 1642 d_drop(new_dentry); 1643 rehash = new_dentry; 1644 } 1645 1646 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", 1647 old_dentry->d_parent->d_name.name, old_dentry->d_name.name, 1648 new_dentry->d_parent->d_name.name, new_dentry->d_name.name, 1649 atomic_read(&new_dentry->d_count)); 1650 1651 /* 1652 * First check whether the target is busy ... we can't 1653 * safely do _any_ rename if the target is in use. 1654 * 1655 * For files, make a copy of the dentry and then do a 1656 * silly-rename. If the silly-rename succeeds, the 1657 * copied dentry is hashed and becomes the new target. 1658 */ 1659 if (!new_inode) 1660 goto go_ahead; 1661 if (S_ISDIR(new_inode->i_mode)) { 1662 error = -EISDIR; 1663 if (!S_ISDIR(old_inode->i_mode)) 1664 goto out; 1665 } else if (atomic_read(&new_dentry->d_count) > 2) { 1666 int err; 1667 /* copy the target dentry's name */ 1668 dentry = d_alloc(new_dentry->d_parent, 1669 &new_dentry->d_name); 1670 if (!dentry) 1671 goto out; 1672 1673 /* silly-rename the existing target ... */ 1674 err = nfs_sillyrename(new_dir, new_dentry); 1675 if (!err) { 1676 new_dentry = rehash = dentry; 1677 new_inode = NULL; 1678 /* instantiate the replacement target */ 1679 d_instantiate(new_dentry, NULL); 1680 } else if (atomic_read(&new_dentry->d_count) > 1) 1681 /* dentry still busy? */ 1682 goto out; 1683 } else 1684 drop_nlink(new_inode); 1685 1686 go_ahead: 1687 /* 1688 * ... prune child dentries and writebacks if needed. 1689 */ 1690 if (atomic_read(&old_dentry->d_count) > 1) { 1691 if (S_ISREG(old_inode->i_mode)) 1692 nfs_wb_all(old_inode); 1693 shrink_dcache_parent(old_dentry); 1694 } 1695 nfs_inode_return_delegation(old_inode); 1696 1697 if (new_inode != NULL) { 1698 nfs_inode_return_delegation(new_inode); 1699 d_delete(new_dentry); 1700 } 1701 1702 nfs_begin_data_update(old_dir); 1703 nfs_begin_data_update(new_dir); 1704 nfs_begin_data_update(old_inode); 1705 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name, 1706 new_dir, &new_dentry->d_name); 1707 nfs_mark_for_revalidate(old_inode); 1708 nfs_end_data_update(old_inode); 1709 nfs_end_data_update(new_dir); 1710 nfs_end_data_update(old_dir); 1711 out: 1712 if (rehash) 1713 d_rehash(rehash); 1714 if (!error) { 1715 d_move(old_dentry, new_dentry); 1716 nfs_renew_times(new_dentry); 1717 nfs_refresh_verifier(new_dentry, nfs_save_change_attribute(new_dir)); 1718 } 1719 1720 /* new dentry created? */ 1721 if (dentry) 1722 dput(dentry); 1723 unlock_kernel(); 1724 return error; 1725 } 1726 1727 static DEFINE_SPINLOCK(nfs_access_lru_lock); 1728 static LIST_HEAD(nfs_access_lru_list); 1729 static atomic_long_t nfs_access_nr_entries; 1730 1731 static void nfs_access_free_entry(struct nfs_access_entry *entry) 1732 { 1733 put_rpccred(entry->cred); 1734 kfree(entry); 1735 smp_mb__before_atomic_dec(); 1736 atomic_long_dec(&nfs_access_nr_entries); 1737 smp_mb__after_atomic_dec(); 1738 } 1739 1740 int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask) 1741 { 1742 LIST_HEAD(head); 1743 struct nfs_inode *nfsi; 1744 struct nfs_access_entry *cache; 1745 1746 spin_lock(&nfs_access_lru_lock); 1747 restart: 1748 list_for_each_entry(nfsi, &nfs_access_lru_list, access_cache_inode_lru) { 1749 struct inode *inode; 1750 1751 if (nr_to_scan-- == 0) 1752 break; 1753 inode = igrab(&nfsi->vfs_inode); 1754 if (inode == NULL) 1755 continue; 1756 spin_lock(&inode->i_lock); 1757 if (list_empty(&nfsi->access_cache_entry_lru)) 1758 goto remove_lru_entry; 1759 cache = list_entry(nfsi->access_cache_entry_lru.next, 1760 struct nfs_access_entry, lru); 1761 list_move(&cache->lru, &head); 1762 rb_erase(&cache->rb_node, &nfsi->access_cache); 1763 if (!list_empty(&nfsi->access_cache_entry_lru)) 1764 list_move_tail(&nfsi->access_cache_inode_lru, 1765 &nfs_access_lru_list); 1766 else { 1767 remove_lru_entry: 1768 list_del_init(&nfsi->access_cache_inode_lru); 1769 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); 1770 } 1771 spin_unlock(&inode->i_lock); 1772 iput(inode); 1773 goto restart; 1774 } 1775 spin_unlock(&nfs_access_lru_lock); 1776 while (!list_empty(&head)) { 1777 cache = list_entry(head.next, struct nfs_access_entry, lru); 1778 list_del(&cache->lru); 1779 nfs_access_free_entry(cache); 1780 } 1781 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; 1782 } 1783 1784 static void __nfs_access_zap_cache(struct inode *inode) 1785 { 1786 struct nfs_inode *nfsi = NFS_I(inode); 1787 struct rb_root *root_node = &nfsi->access_cache; 1788 struct rb_node *n, *dispose = NULL; 1789 struct nfs_access_entry *entry; 1790 1791 /* Unhook entries from the cache */ 1792 while ((n = rb_first(root_node)) != NULL) { 1793 entry = rb_entry(n, struct nfs_access_entry, rb_node); 1794 rb_erase(n, root_node); 1795 list_del(&entry->lru); 1796 n->rb_left = dispose; 1797 dispose = n; 1798 } 1799 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; 1800 spin_unlock(&inode->i_lock); 1801 1802 /* Now kill them all! */ 1803 while (dispose != NULL) { 1804 n = dispose; 1805 dispose = n->rb_left; 1806 nfs_access_free_entry(rb_entry(n, struct nfs_access_entry, rb_node)); 1807 } 1808 } 1809 1810 void nfs_access_zap_cache(struct inode *inode) 1811 { 1812 /* Remove from global LRU init */ 1813 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_FLAGS(inode))) { 1814 spin_lock(&nfs_access_lru_lock); 1815 list_del_init(&NFS_I(inode)->access_cache_inode_lru); 1816 spin_unlock(&nfs_access_lru_lock); 1817 } 1818 1819 spin_lock(&inode->i_lock); 1820 /* This will release the spinlock */ 1821 __nfs_access_zap_cache(inode); 1822 } 1823 1824 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred) 1825 { 1826 struct rb_node *n = NFS_I(inode)->access_cache.rb_node; 1827 struct nfs_access_entry *entry; 1828 1829 while (n != NULL) { 1830 entry = rb_entry(n, struct nfs_access_entry, rb_node); 1831 1832 if (cred < entry->cred) 1833 n = n->rb_left; 1834 else if (cred > entry->cred) 1835 n = n->rb_right; 1836 else 1837 return entry; 1838 } 1839 return NULL; 1840 } 1841 1842 int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) 1843 { 1844 struct nfs_inode *nfsi = NFS_I(inode); 1845 struct nfs_access_entry *cache; 1846 int err = -ENOENT; 1847 1848 spin_lock(&inode->i_lock); 1849 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) 1850 goto out_zap; 1851 cache = nfs_access_search_rbtree(inode, cred); 1852 if (cache == NULL) 1853 goto out; 1854 if (time_after(jiffies, cache->jiffies + NFS_ATTRTIMEO(inode))) 1855 goto out_stale; 1856 res->jiffies = cache->jiffies; 1857 res->cred = cache->cred; 1858 res->mask = cache->mask; 1859 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); 1860 err = 0; 1861 out: 1862 spin_unlock(&inode->i_lock); 1863 return err; 1864 out_stale: 1865 rb_erase(&cache->rb_node, &nfsi->access_cache); 1866 list_del(&cache->lru); 1867 spin_unlock(&inode->i_lock); 1868 nfs_access_free_entry(cache); 1869 return -ENOENT; 1870 out_zap: 1871 /* This will release the spinlock */ 1872 __nfs_access_zap_cache(inode); 1873 return -ENOENT; 1874 } 1875 1876 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) 1877 { 1878 struct nfs_inode *nfsi = NFS_I(inode); 1879 struct rb_root *root_node = &nfsi->access_cache; 1880 struct rb_node **p = &root_node->rb_node; 1881 struct rb_node *parent = NULL; 1882 struct nfs_access_entry *entry; 1883 1884 spin_lock(&inode->i_lock); 1885 while (*p != NULL) { 1886 parent = *p; 1887 entry = rb_entry(parent, struct nfs_access_entry, rb_node); 1888 1889 if (set->cred < entry->cred) 1890 p = &parent->rb_left; 1891 else if (set->cred > entry->cred) 1892 p = &parent->rb_right; 1893 else 1894 goto found; 1895 } 1896 rb_link_node(&set->rb_node, parent, p); 1897 rb_insert_color(&set->rb_node, root_node); 1898 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); 1899 spin_unlock(&inode->i_lock); 1900 return; 1901 found: 1902 rb_replace_node(parent, &set->rb_node, root_node); 1903 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); 1904 list_del(&entry->lru); 1905 spin_unlock(&inode->i_lock); 1906 nfs_access_free_entry(entry); 1907 } 1908 1909 void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) 1910 { 1911 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); 1912 if (cache == NULL) 1913 return; 1914 RB_CLEAR_NODE(&cache->rb_node); 1915 cache->jiffies = set->jiffies; 1916 cache->cred = get_rpccred(set->cred); 1917 cache->mask = set->mask; 1918 1919 nfs_access_add_rbtree(inode, cache); 1920 1921 /* Update accounting */ 1922 smp_mb__before_atomic_inc(); 1923 atomic_long_inc(&nfs_access_nr_entries); 1924 smp_mb__after_atomic_inc(); 1925 1926 /* Add inode to global LRU list */ 1927 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_FLAGS(inode))) { 1928 spin_lock(&nfs_access_lru_lock); 1929 list_add_tail(&NFS_I(inode)->access_cache_inode_lru, &nfs_access_lru_list); 1930 spin_unlock(&nfs_access_lru_lock); 1931 } 1932 } 1933 1934 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) 1935 { 1936 struct nfs_access_entry cache; 1937 int status; 1938 1939 status = nfs_access_get_cached(inode, cred, &cache); 1940 if (status == 0) 1941 goto out; 1942 1943 /* Be clever: ask server to check for all possible rights */ 1944 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; 1945 cache.cred = cred; 1946 cache.jiffies = jiffies; 1947 status = NFS_PROTO(inode)->access(inode, &cache); 1948 if (status != 0) 1949 return status; 1950 nfs_access_add_cache(inode, &cache); 1951 out: 1952 if ((cache.mask & mask) == mask) 1953 return 0; 1954 return -EACCES; 1955 } 1956 1957 int nfs_permission(struct inode *inode, int mask, struct nameidata *nd) 1958 { 1959 struct rpc_cred *cred; 1960 int res = 0; 1961 1962 nfs_inc_stats(inode, NFSIOS_VFSACCESS); 1963 1964 if (mask == 0) 1965 goto out; 1966 /* Is this sys_access() ? */ 1967 if (nd != NULL && (nd->flags & LOOKUP_ACCESS)) 1968 goto force_lookup; 1969 1970 switch (inode->i_mode & S_IFMT) { 1971 case S_IFLNK: 1972 goto out; 1973 case S_IFREG: 1974 /* NFSv4 has atomic_open... */ 1975 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) 1976 && nd != NULL 1977 && (nd->flags & LOOKUP_OPEN)) 1978 goto out; 1979 break; 1980 case S_IFDIR: 1981 /* 1982 * Optimize away all write operations, since the server 1983 * will check permissions when we perform the op. 1984 */ 1985 if ((mask & MAY_WRITE) && !(mask & MAY_READ)) 1986 goto out; 1987 } 1988 1989 force_lookup: 1990 lock_kernel(); 1991 1992 if (!NFS_PROTO(inode)->access) 1993 goto out_notsup; 1994 1995 cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0); 1996 if (!IS_ERR(cred)) { 1997 res = nfs_do_access(inode, cred, mask); 1998 put_rpccred(cred); 1999 } else 2000 res = PTR_ERR(cred); 2001 unlock_kernel(); 2002 out: 2003 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n", 2004 inode->i_sb->s_id, inode->i_ino, mask, res); 2005 return res; 2006 out_notsup: 2007 res = nfs_revalidate_inode(NFS_SERVER(inode), inode); 2008 if (res == 0) 2009 res = generic_permission(inode, mask, NULL); 2010 unlock_kernel(); 2011 goto out; 2012 } 2013 2014 /* 2015 * Local variables: 2016 * version-control: t 2017 * kept-new-versions: 5 2018 * End: 2019 */ 2020