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/pagevec.h> 33 #include <linux/namei.h> 34 #include <linux/mount.h> 35 #include <linux/sched.h> 36 #include <linux/kmemleak.h> 37 #include <linux/xattr.h> 38 39 #include "delegation.h" 40 #include "iostat.h" 41 #include "internal.h" 42 #include "fscache.h" 43 44 /* #define NFS_DEBUG_VERBOSE 1 */ 45 46 static int nfs_opendir(struct inode *, struct file *); 47 static int nfs_closedir(struct inode *, struct file *); 48 static int nfs_readdir(struct file *, void *, filldir_t); 49 static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *); 50 static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *); 51 static int nfs_mkdir(struct inode *, struct dentry *, int); 52 static int nfs_rmdir(struct inode *, struct dentry *); 53 static int nfs_unlink(struct inode *, struct dentry *); 54 static int nfs_symlink(struct inode *, struct dentry *, const char *); 55 static int nfs_link(struct dentry *, struct inode *, struct dentry *); 56 static int nfs_mknod(struct inode *, struct dentry *, int, dev_t); 57 static int nfs_rename(struct inode *, struct dentry *, 58 struct inode *, struct dentry *); 59 static int nfs_fsync_dir(struct file *, int); 60 static loff_t nfs_llseek_dir(struct file *, loff_t, int); 61 static void nfs_readdir_clear_array(struct page*); 62 63 const struct file_operations nfs_dir_operations = { 64 .llseek = nfs_llseek_dir, 65 .read = generic_read_dir, 66 .readdir = nfs_readdir, 67 .open = nfs_opendir, 68 .release = nfs_closedir, 69 .fsync = nfs_fsync_dir, 70 }; 71 72 const struct inode_operations nfs_dir_inode_operations = { 73 .create = nfs_create, 74 .lookup = nfs_lookup, 75 .link = nfs_link, 76 .unlink = nfs_unlink, 77 .symlink = nfs_symlink, 78 .mkdir = nfs_mkdir, 79 .rmdir = nfs_rmdir, 80 .mknod = nfs_mknod, 81 .rename = nfs_rename, 82 .permission = nfs_permission, 83 .getattr = nfs_getattr, 84 .setattr = nfs_setattr, 85 }; 86 87 const struct address_space_operations nfs_dir_aops = { 88 .freepage = nfs_readdir_clear_array, 89 }; 90 91 #ifdef CONFIG_NFS_V3 92 const struct inode_operations nfs3_dir_inode_operations = { 93 .create = nfs_create, 94 .lookup = nfs_lookup, 95 .link = nfs_link, 96 .unlink = nfs_unlink, 97 .symlink = nfs_symlink, 98 .mkdir = nfs_mkdir, 99 .rmdir = nfs_rmdir, 100 .mknod = nfs_mknod, 101 .rename = nfs_rename, 102 .permission = nfs_permission, 103 .getattr = nfs_getattr, 104 .setattr = nfs_setattr, 105 .listxattr = nfs3_listxattr, 106 .getxattr = nfs3_getxattr, 107 .setxattr = nfs3_setxattr, 108 .removexattr = nfs3_removexattr, 109 }; 110 #endif /* CONFIG_NFS_V3 */ 111 112 #ifdef CONFIG_NFS_V4 113 114 static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *); 115 static int nfs_open_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd); 116 const struct inode_operations nfs4_dir_inode_operations = { 117 .create = nfs_open_create, 118 .lookup = nfs_atomic_lookup, 119 .link = nfs_link, 120 .unlink = nfs_unlink, 121 .symlink = nfs_symlink, 122 .mkdir = nfs_mkdir, 123 .rmdir = nfs_rmdir, 124 .mknod = nfs_mknod, 125 .rename = nfs_rename, 126 .permission = nfs_permission, 127 .getattr = nfs_getattr, 128 .setattr = nfs_setattr, 129 .getxattr = generic_getxattr, 130 .setxattr = generic_setxattr, 131 .listxattr = generic_listxattr, 132 .removexattr = generic_removexattr, 133 }; 134 135 #endif /* CONFIG_NFS_V4 */ 136 137 static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct rpc_cred *cred) 138 { 139 struct nfs_open_dir_context *ctx; 140 ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); 141 if (ctx != NULL) { 142 ctx->duped = 0; 143 ctx->dir_cookie = 0; 144 ctx->dup_cookie = 0; 145 ctx->cred = get_rpccred(cred); 146 } else 147 ctx = ERR_PTR(-ENOMEM); 148 return ctx; 149 } 150 151 static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx) 152 { 153 put_rpccred(ctx->cred); 154 kfree(ctx); 155 } 156 157 /* 158 * Open file 159 */ 160 static int 161 nfs_opendir(struct inode *inode, struct file *filp) 162 { 163 int res = 0; 164 struct nfs_open_dir_context *ctx; 165 struct rpc_cred *cred; 166 167 dfprintk(FILE, "NFS: open dir(%s/%s)\n", 168 filp->f_path.dentry->d_parent->d_name.name, 169 filp->f_path.dentry->d_name.name); 170 171 nfs_inc_stats(inode, NFSIOS_VFSOPEN); 172 173 cred = rpc_lookup_cred(); 174 if (IS_ERR(cred)) 175 return PTR_ERR(cred); 176 ctx = alloc_nfs_open_dir_context(cred); 177 if (IS_ERR(ctx)) { 178 res = PTR_ERR(ctx); 179 goto out; 180 } 181 filp->private_data = ctx; 182 if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) { 183 /* This is a mountpoint, so d_revalidate will never 184 * have been called, so we need to refresh the 185 * inode (for close-open consistency) ourselves. 186 */ 187 __nfs_revalidate_inode(NFS_SERVER(inode), inode); 188 } 189 out: 190 put_rpccred(cred); 191 return res; 192 } 193 194 static int 195 nfs_closedir(struct inode *inode, struct file *filp) 196 { 197 put_nfs_open_dir_context(filp->private_data); 198 return 0; 199 } 200 201 struct nfs_cache_array_entry { 202 u64 cookie; 203 u64 ino; 204 struct qstr string; 205 unsigned char d_type; 206 }; 207 208 struct nfs_cache_array { 209 unsigned int size; 210 int eof_index; 211 u64 last_cookie; 212 struct nfs_cache_array_entry array[0]; 213 }; 214 215 typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int); 216 typedef struct { 217 struct file *file; 218 struct page *page; 219 unsigned long page_index; 220 u64 *dir_cookie; 221 u64 last_cookie; 222 loff_t current_index; 223 decode_dirent_t decode; 224 225 unsigned long timestamp; 226 unsigned long gencount; 227 unsigned int cache_entry_index; 228 unsigned int plus:1; 229 unsigned int eof:1; 230 } nfs_readdir_descriptor_t; 231 232 /* 233 * The caller is responsible for calling nfs_readdir_release_array(page) 234 */ 235 static 236 struct nfs_cache_array *nfs_readdir_get_array(struct page *page) 237 { 238 void *ptr; 239 if (page == NULL) 240 return ERR_PTR(-EIO); 241 ptr = kmap(page); 242 if (ptr == NULL) 243 return ERR_PTR(-ENOMEM); 244 return ptr; 245 } 246 247 static 248 void nfs_readdir_release_array(struct page *page) 249 { 250 kunmap(page); 251 } 252 253 /* 254 * we are freeing strings created by nfs_add_to_readdir_array() 255 */ 256 static 257 void nfs_readdir_clear_array(struct page *page) 258 { 259 struct nfs_cache_array *array; 260 int i; 261 262 array = kmap_atomic(page, KM_USER0); 263 for (i = 0; i < array->size; i++) 264 kfree(array->array[i].string.name); 265 kunmap_atomic(array, KM_USER0); 266 } 267 268 /* 269 * the caller is responsible for freeing qstr.name 270 * when called by nfs_readdir_add_to_array, the strings will be freed in 271 * nfs_clear_readdir_array() 272 */ 273 static 274 int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len) 275 { 276 string->len = len; 277 string->name = kmemdup(name, len, GFP_KERNEL); 278 if (string->name == NULL) 279 return -ENOMEM; 280 /* 281 * Avoid a kmemleak false positive. The pointer to the name is stored 282 * in a page cache page which kmemleak does not scan. 283 */ 284 kmemleak_not_leak(string->name); 285 string->hash = full_name_hash(name, len); 286 return 0; 287 } 288 289 static 290 int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) 291 { 292 struct nfs_cache_array *array = nfs_readdir_get_array(page); 293 struct nfs_cache_array_entry *cache_entry; 294 int ret; 295 296 if (IS_ERR(array)) 297 return PTR_ERR(array); 298 299 cache_entry = &array->array[array->size]; 300 301 /* Check that this entry lies within the page bounds */ 302 ret = -ENOSPC; 303 if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE) 304 goto out; 305 306 cache_entry->cookie = entry->prev_cookie; 307 cache_entry->ino = entry->ino; 308 cache_entry->d_type = entry->d_type; 309 ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len); 310 if (ret) 311 goto out; 312 array->last_cookie = entry->cookie; 313 array->size++; 314 if (entry->eof != 0) 315 array->eof_index = array->size; 316 out: 317 nfs_readdir_release_array(page); 318 return ret; 319 } 320 321 static 322 int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) 323 { 324 loff_t diff = desc->file->f_pos - desc->current_index; 325 unsigned int index; 326 struct nfs_open_dir_context *ctx = desc->file->private_data; 327 328 if (diff < 0) 329 goto out_eof; 330 if (diff >= array->size) { 331 if (array->eof_index >= 0) 332 goto out_eof; 333 return -EAGAIN; 334 } 335 336 index = (unsigned int)diff; 337 *desc->dir_cookie = array->array[index].cookie; 338 desc->cache_entry_index = index; 339 ctx->duped = 0; 340 return 0; 341 out_eof: 342 desc->eof = 1; 343 return -EBADCOOKIE; 344 } 345 346 static 347 int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) 348 { 349 int i; 350 loff_t new_pos; 351 int status = -EAGAIN; 352 struct nfs_open_dir_context *ctx = desc->file->private_data; 353 354 for (i = 0; i < array->size; i++) { 355 if (array->array[i].cookie == *desc->dir_cookie) { 356 new_pos = desc->current_index + i; 357 if (new_pos < desc->file->f_pos) { 358 ctx->dup_cookie = *desc->dir_cookie; 359 ctx->duped = 1; 360 } 361 desc->file->f_pos = new_pos; 362 desc->cache_entry_index = i; 363 return 0; 364 } 365 } 366 if (array->eof_index >= 0) { 367 status = -EBADCOOKIE; 368 if (*desc->dir_cookie == array->last_cookie) 369 desc->eof = 1; 370 } 371 return status; 372 } 373 374 static 375 int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc) 376 { 377 struct nfs_cache_array *array; 378 int status; 379 380 array = nfs_readdir_get_array(desc->page); 381 if (IS_ERR(array)) { 382 status = PTR_ERR(array); 383 goto out; 384 } 385 386 if (*desc->dir_cookie == 0) 387 status = nfs_readdir_search_for_pos(array, desc); 388 else 389 status = nfs_readdir_search_for_cookie(array, desc); 390 391 if (status == -EAGAIN) { 392 desc->last_cookie = array->last_cookie; 393 desc->current_index += array->size; 394 desc->page_index++; 395 } 396 nfs_readdir_release_array(desc->page); 397 out: 398 return status; 399 } 400 401 /* Fill a page with xdr information before transferring to the cache page */ 402 static 403 int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc, 404 struct nfs_entry *entry, struct file *file, struct inode *inode) 405 { 406 struct nfs_open_dir_context *ctx = file->private_data; 407 struct rpc_cred *cred = ctx->cred; 408 unsigned long timestamp, gencount; 409 int error; 410 411 again: 412 timestamp = jiffies; 413 gencount = nfs_inc_attr_generation_counter(); 414 error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages, 415 NFS_SERVER(inode)->dtsize, desc->plus); 416 if (error < 0) { 417 /* We requested READDIRPLUS, but the server doesn't grok it */ 418 if (error == -ENOTSUPP && desc->plus) { 419 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; 420 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); 421 desc->plus = 0; 422 goto again; 423 } 424 goto error; 425 } 426 desc->timestamp = timestamp; 427 desc->gencount = gencount; 428 error: 429 return error; 430 } 431 432 static int xdr_decode(nfs_readdir_descriptor_t *desc, 433 struct nfs_entry *entry, struct xdr_stream *xdr) 434 { 435 int error; 436 437 error = desc->decode(xdr, entry, desc->plus); 438 if (error) 439 return error; 440 entry->fattr->time_start = desc->timestamp; 441 entry->fattr->gencount = desc->gencount; 442 return 0; 443 } 444 445 static 446 int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry) 447 { 448 if (dentry->d_inode == NULL) 449 goto different; 450 if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0) 451 goto different; 452 return 1; 453 different: 454 return 0; 455 } 456 457 static 458 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) 459 { 460 struct qstr filename = { 461 .len = entry->len, 462 .name = entry->name, 463 }; 464 struct dentry *dentry; 465 struct dentry *alias; 466 struct inode *dir = parent->d_inode; 467 struct inode *inode; 468 469 if (filename.name[0] == '.') { 470 if (filename.len == 1) 471 return; 472 if (filename.len == 2 && filename.name[1] == '.') 473 return; 474 } 475 filename.hash = full_name_hash(filename.name, filename.len); 476 477 dentry = d_lookup(parent, &filename); 478 if (dentry != NULL) { 479 if (nfs_same_file(dentry, entry)) { 480 nfs_refresh_inode(dentry->d_inode, entry->fattr); 481 goto out; 482 } else { 483 d_drop(dentry); 484 dput(dentry); 485 } 486 } 487 488 dentry = d_alloc(parent, &filename); 489 if (dentry == NULL) 490 return; 491 492 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); 493 if (IS_ERR(inode)) 494 goto out; 495 496 alias = d_materialise_unique(dentry, inode); 497 if (IS_ERR(alias)) 498 goto out; 499 else if (alias) { 500 nfs_set_verifier(alias, nfs_save_change_attribute(dir)); 501 dput(alias); 502 } else 503 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 504 505 out: 506 dput(dentry); 507 } 508 509 /* Perform conversion from xdr to cache array */ 510 static 511 int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, 512 struct page **xdr_pages, struct page *page, unsigned int buflen) 513 { 514 struct xdr_stream stream; 515 struct xdr_buf buf; 516 struct page *scratch; 517 struct nfs_cache_array *array; 518 unsigned int count = 0; 519 int status; 520 521 scratch = alloc_page(GFP_KERNEL); 522 if (scratch == NULL) 523 return -ENOMEM; 524 525 xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen); 526 xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE); 527 528 do { 529 status = xdr_decode(desc, entry, &stream); 530 if (status != 0) { 531 if (status == -EAGAIN) 532 status = 0; 533 break; 534 } 535 536 count++; 537 538 if (desc->plus != 0) 539 nfs_prime_dcache(desc->file->f_path.dentry, entry); 540 541 status = nfs_readdir_add_to_array(entry, page); 542 if (status != 0) 543 break; 544 } while (!entry->eof); 545 546 if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) { 547 array = nfs_readdir_get_array(page); 548 if (!IS_ERR(array)) { 549 array->eof_index = array->size; 550 status = 0; 551 nfs_readdir_release_array(page); 552 } else 553 status = PTR_ERR(array); 554 } 555 556 put_page(scratch); 557 return status; 558 } 559 560 static 561 void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages) 562 { 563 unsigned int i; 564 for (i = 0; i < npages; i++) 565 put_page(pages[i]); 566 } 567 568 static 569 void nfs_readdir_free_large_page(void *ptr, struct page **pages, 570 unsigned int npages) 571 { 572 nfs_readdir_free_pagearray(pages, npages); 573 } 574 575 /* 576 * nfs_readdir_large_page will allocate pages that must be freed with a call 577 * to nfs_readdir_free_large_page 578 */ 579 static 580 int nfs_readdir_large_page(struct page **pages, unsigned int npages) 581 { 582 unsigned int i; 583 584 for (i = 0; i < npages; i++) { 585 struct page *page = alloc_page(GFP_KERNEL); 586 if (page == NULL) 587 goto out_freepages; 588 pages[i] = page; 589 } 590 return 0; 591 592 out_freepages: 593 nfs_readdir_free_pagearray(pages, i); 594 return -ENOMEM; 595 } 596 597 static 598 int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode) 599 { 600 struct page *pages[NFS_MAX_READDIR_PAGES]; 601 void *pages_ptr = NULL; 602 struct nfs_entry entry; 603 struct file *file = desc->file; 604 struct nfs_cache_array *array; 605 int status = -ENOMEM; 606 unsigned int array_size = ARRAY_SIZE(pages); 607 608 entry.prev_cookie = 0; 609 entry.cookie = desc->last_cookie; 610 entry.eof = 0; 611 entry.fh = nfs_alloc_fhandle(); 612 entry.fattr = nfs_alloc_fattr(); 613 entry.server = NFS_SERVER(inode); 614 if (entry.fh == NULL || entry.fattr == NULL) 615 goto out; 616 617 array = nfs_readdir_get_array(page); 618 if (IS_ERR(array)) { 619 status = PTR_ERR(array); 620 goto out; 621 } 622 memset(array, 0, sizeof(struct nfs_cache_array)); 623 array->eof_index = -1; 624 625 status = nfs_readdir_large_page(pages, array_size); 626 if (status < 0) 627 goto out_release_array; 628 do { 629 unsigned int pglen; 630 status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode); 631 632 if (status < 0) 633 break; 634 pglen = status; 635 status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen); 636 if (status < 0) { 637 if (status == -ENOSPC) 638 status = 0; 639 break; 640 } 641 } while (array->eof_index < 0); 642 643 nfs_readdir_free_large_page(pages_ptr, pages, array_size); 644 out_release_array: 645 nfs_readdir_release_array(page); 646 out: 647 nfs_free_fattr(entry.fattr); 648 nfs_free_fhandle(entry.fh); 649 return status; 650 } 651 652 /* 653 * Now we cache directories properly, by converting xdr information 654 * to an array that can be used for lookups later. This results in 655 * fewer cache pages, since we can store more information on each page. 656 * We only need to convert from xdr once so future lookups are much simpler 657 */ 658 static 659 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page) 660 { 661 struct inode *inode = desc->file->f_path.dentry->d_inode; 662 int ret; 663 664 ret = nfs_readdir_xdr_to_array(desc, page, inode); 665 if (ret < 0) 666 goto error; 667 SetPageUptodate(page); 668 669 if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) { 670 /* Should never happen */ 671 nfs_zap_mapping(inode, inode->i_mapping); 672 } 673 unlock_page(page); 674 return 0; 675 error: 676 unlock_page(page); 677 return ret; 678 } 679 680 static 681 void cache_page_release(nfs_readdir_descriptor_t *desc) 682 { 683 if (!desc->page->mapping) 684 nfs_readdir_clear_array(desc->page); 685 page_cache_release(desc->page); 686 desc->page = NULL; 687 } 688 689 static 690 struct page *get_cache_page(nfs_readdir_descriptor_t *desc) 691 { 692 return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping, 693 desc->page_index, (filler_t *)nfs_readdir_filler, desc); 694 } 695 696 /* 697 * Returns 0 if desc->dir_cookie was found on page desc->page_index 698 */ 699 static 700 int find_cache_page(nfs_readdir_descriptor_t *desc) 701 { 702 int res; 703 704 desc->page = get_cache_page(desc); 705 if (IS_ERR(desc->page)) 706 return PTR_ERR(desc->page); 707 708 res = nfs_readdir_search_array(desc); 709 if (res != 0) 710 cache_page_release(desc); 711 return res; 712 } 713 714 /* Search for desc->dir_cookie from the beginning of the page cache */ 715 static inline 716 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) 717 { 718 int res; 719 720 if (desc->page_index == 0) { 721 desc->current_index = 0; 722 desc->last_cookie = 0; 723 } 724 do { 725 res = find_cache_page(desc); 726 } while (res == -EAGAIN); 727 return res; 728 } 729 730 /* 731 * Once we've found the start of the dirent within a page: fill 'er up... 732 */ 733 static 734 int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, 735 filldir_t filldir) 736 { 737 struct file *file = desc->file; 738 int i = 0; 739 int res = 0; 740 struct nfs_cache_array *array = NULL; 741 struct nfs_open_dir_context *ctx = file->private_data; 742 743 if (ctx->duped != 0 && ctx->dup_cookie == *desc->dir_cookie) { 744 if (printk_ratelimit()) { 745 pr_notice("NFS: directory %s/%s contains a readdir loop. " 746 "Please contact your server vendor. " 747 "Offending cookie: %llu\n", 748 file->f_dentry->d_parent->d_name.name, 749 file->f_dentry->d_name.name, 750 *desc->dir_cookie); 751 } 752 res = -ELOOP; 753 goto out; 754 } 755 756 array = nfs_readdir_get_array(desc->page); 757 if (IS_ERR(array)) { 758 res = PTR_ERR(array); 759 goto out; 760 } 761 762 for (i = desc->cache_entry_index; i < array->size; i++) { 763 struct nfs_cache_array_entry *ent; 764 765 ent = &array->array[i]; 766 if (filldir(dirent, ent->string.name, ent->string.len, 767 file->f_pos, nfs_compat_user_ino64(ent->ino), 768 ent->d_type) < 0) { 769 desc->eof = 1; 770 break; 771 } 772 file->f_pos++; 773 if (i < (array->size-1)) 774 *desc->dir_cookie = array->array[i+1].cookie; 775 else 776 *desc->dir_cookie = array->last_cookie; 777 } 778 if (array->eof_index >= 0) 779 desc->eof = 1; 780 781 nfs_readdir_release_array(desc->page); 782 out: 783 cache_page_release(desc); 784 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", 785 (unsigned long long)*desc->dir_cookie, res); 786 return res; 787 } 788 789 /* 790 * If we cannot find a cookie in our cache, we suspect that this is 791 * because it points to a deleted file, so we ask the server to return 792 * whatever it thinks is the next entry. We then feed this to filldir. 793 * If all goes well, we should then be able to find our way round the 794 * cache on the next call to readdir_search_pagecache(); 795 * 796 * NOTE: we cannot add the anonymous page to the pagecache because 797 * the data it contains might not be page aligned. Besides, 798 * we should already have a complete representation of the 799 * directory in the page cache by the time we get here. 800 */ 801 static inline 802 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent, 803 filldir_t filldir) 804 { 805 struct page *page = NULL; 806 int status; 807 struct inode *inode = desc->file->f_path.dentry->d_inode; 808 809 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n", 810 (unsigned long long)*desc->dir_cookie); 811 812 page = alloc_page(GFP_HIGHUSER); 813 if (!page) { 814 status = -ENOMEM; 815 goto out; 816 } 817 818 desc->page_index = 0; 819 desc->last_cookie = *desc->dir_cookie; 820 desc->page = page; 821 822 status = nfs_readdir_xdr_to_array(desc, page, inode); 823 if (status < 0) 824 goto out_release; 825 826 status = nfs_do_filldir(desc, dirent, filldir); 827 828 out: 829 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", 830 __func__, status); 831 return status; 832 out_release: 833 cache_page_release(desc); 834 goto out; 835 } 836 837 /* The file offset position represents the dirent entry number. A 838 last cookie cache takes care of the common case of reading the 839 whole directory. 840 */ 841 static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir) 842 { 843 struct dentry *dentry = filp->f_path.dentry; 844 struct inode *inode = dentry->d_inode; 845 nfs_readdir_descriptor_t my_desc, 846 *desc = &my_desc; 847 struct nfs_open_dir_context *dir_ctx = filp->private_data; 848 int res; 849 850 dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n", 851 dentry->d_parent->d_name.name, dentry->d_name.name, 852 (long long)filp->f_pos); 853 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); 854 855 /* 856 * filp->f_pos points to the dirent entry number. 857 * *desc->dir_cookie has the cookie for the next entry. We have 858 * to either find the entry with the appropriate number or 859 * revalidate the cookie. 860 */ 861 memset(desc, 0, sizeof(*desc)); 862 863 desc->file = filp; 864 desc->dir_cookie = &dir_ctx->dir_cookie; 865 desc->decode = NFS_PROTO(inode)->decode_dirent; 866 desc->plus = NFS_USE_READDIRPLUS(inode); 867 868 nfs_block_sillyrename(dentry); 869 res = nfs_revalidate_mapping(inode, filp->f_mapping); 870 if (res < 0) 871 goto out; 872 873 do { 874 res = readdir_search_pagecache(desc); 875 876 if (res == -EBADCOOKIE) { 877 res = 0; 878 /* This means either end of directory */ 879 if (*desc->dir_cookie && desc->eof == 0) { 880 /* Or that the server has 'lost' a cookie */ 881 res = uncached_readdir(desc, dirent, filldir); 882 if (res == 0) 883 continue; 884 } 885 break; 886 } 887 if (res == -ETOOSMALL && desc->plus) { 888 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); 889 nfs_zap_caches(inode); 890 desc->page_index = 0; 891 desc->plus = 0; 892 desc->eof = 0; 893 continue; 894 } 895 if (res < 0) 896 break; 897 898 res = nfs_do_filldir(desc, dirent, filldir); 899 if (res < 0) 900 break; 901 } while (!desc->eof); 902 out: 903 nfs_unblock_sillyrename(dentry); 904 if (res > 0) 905 res = 0; 906 dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n", 907 dentry->d_parent->d_name.name, dentry->d_name.name, 908 res); 909 return res; 910 } 911 912 static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin) 913 { 914 struct dentry *dentry = filp->f_path.dentry; 915 struct inode *inode = dentry->d_inode; 916 struct nfs_open_dir_context *dir_ctx = filp->private_data; 917 918 dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n", 919 dentry->d_parent->d_name.name, 920 dentry->d_name.name, 921 offset, origin); 922 923 mutex_lock(&inode->i_mutex); 924 switch (origin) { 925 case 1: 926 offset += filp->f_pos; 927 case 0: 928 if (offset >= 0) 929 break; 930 default: 931 offset = -EINVAL; 932 goto out; 933 } 934 if (offset != filp->f_pos) { 935 filp->f_pos = offset; 936 dir_ctx->dir_cookie = 0; 937 dir_ctx->duped = 0; 938 } 939 out: 940 mutex_unlock(&inode->i_mutex); 941 return offset; 942 } 943 944 /* 945 * All directory operations under NFS are synchronous, so fsync() 946 * is a dummy operation. 947 */ 948 static int nfs_fsync_dir(struct file *filp, int datasync) 949 { 950 struct dentry *dentry = filp->f_path.dentry; 951 952 dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n", 953 dentry->d_parent->d_name.name, dentry->d_name.name, 954 datasync); 955 956 nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC); 957 return 0; 958 } 959 960 /** 961 * nfs_force_lookup_revalidate - Mark the directory as having changed 962 * @dir - pointer to directory inode 963 * 964 * This forces the revalidation code in nfs_lookup_revalidate() to do a 965 * full lookup on all child dentries of 'dir' whenever a change occurs 966 * on the server that might have invalidated our dcache. 967 * 968 * The caller should be holding dir->i_lock 969 */ 970 void nfs_force_lookup_revalidate(struct inode *dir) 971 { 972 NFS_I(dir)->cache_change_attribute++; 973 } 974 975 /* 976 * A check for whether or not the parent directory has changed. 977 * In the case it has, we assume that the dentries are untrustworthy 978 * and may need to be looked up again. 979 */ 980 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) 981 { 982 if (IS_ROOT(dentry)) 983 return 1; 984 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) 985 return 0; 986 if (!nfs_verify_change_attribute(dir, dentry->d_time)) 987 return 0; 988 /* Revalidate nfsi->cache_change_attribute before we declare a match */ 989 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) 990 return 0; 991 if (!nfs_verify_change_attribute(dir, dentry->d_time)) 992 return 0; 993 return 1; 994 } 995 996 /* 997 * Return the intent data that applies to this particular path component 998 * 999 * Note that the current set of intents only apply to the very last 1000 * component of the path. 1001 * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT. 1002 */ 1003 static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, 1004 unsigned int mask) 1005 { 1006 if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT)) 1007 return 0; 1008 return nd->flags & mask; 1009 } 1010 1011 /* 1012 * Use intent information to check whether or not we're going to do 1013 * an O_EXCL create using this path component. 1014 */ 1015 static int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd) 1016 { 1017 if (NFS_PROTO(dir)->version == 2) 1018 return 0; 1019 return nd && nfs_lookup_check_intent(nd, LOOKUP_EXCL); 1020 } 1021 1022 /* 1023 * Inode and filehandle revalidation for lookups. 1024 * 1025 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL, 1026 * or if the intent information indicates that we're about to open this 1027 * particular file and the "nocto" mount flag is not set. 1028 * 1029 */ 1030 static inline 1031 int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd) 1032 { 1033 struct nfs_server *server = NFS_SERVER(inode); 1034 1035 if (IS_AUTOMOUNT(inode)) 1036 return 0; 1037 if (nd != NULL) { 1038 /* VFS wants an on-the-wire revalidation */ 1039 if (nd->flags & LOOKUP_REVAL) 1040 goto out_force; 1041 /* This is an open(2) */ 1042 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 && 1043 !(server->flags & NFS_MOUNT_NOCTO) && 1044 (S_ISREG(inode->i_mode) || 1045 S_ISDIR(inode->i_mode))) 1046 goto out_force; 1047 return 0; 1048 } 1049 return nfs_revalidate_inode(server, inode); 1050 out_force: 1051 return __nfs_revalidate_inode(server, inode); 1052 } 1053 1054 /* 1055 * We judge how long we want to trust negative 1056 * dentries by looking at the parent inode mtime. 1057 * 1058 * If parent mtime has changed, we revalidate, else we wait for a 1059 * period corresponding to the parent's attribute cache timeout value. 1060 */ 1061 static inline 1062 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, 1063 struct nameidata *nd) 1064 { 1065 /* Don't revalidate a negative dentry if we're creating a new file */ 1066 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) 1067 return 0; 1068 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) 1069 return 1; 1070 return !nfs_check_verifier(dir, dentry); 1071 } 1072 1073 /* 1074 * This is called every time the dcache has a lookup hit, 1075 * and we should check whether we can really trust that 1076 * lookup. 1077 * 1078 * NOTE! The hit can be a negative hit too, don't assume 1079 * we have an inode! 1080 * 1081 * If the parent directory is seen to have changed, we throw out the 1082 * cached dentry and do a new lookup. 1083 */ 1084 static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd) 1085 { 1086 struct inode *dir; 1087 struct inode *inode; 1088 struct dentry *parent; 1089 struct nfs_fh *fhandle = NULL; 1090 struct nfs_fattr *fattr = NULL; 1091 int error; 1092 1093 if (nd->flags & LOOKUP_RCU) 1094 return -ECHILD; 1095 1096 parent = dget_parent(dentry); 1097 dir = parent->d_inode; 1098 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); 1099 inode = dentry->d_inode; 1100 1101 if (!inode) { 1102 if (nfs_neg_need_reval(dir, dentry, nd)) 1103 goto out_bad; 1104 goto out_valid; 1105 } 1106 1107 if (is_bad_inode(inode)) { 1108 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n", 1109 __func__, dentry->d_parent->d_name.name, 1110 dentry->d_name.name); 1111 goto out_bad; 1112 } 1113 1114 if (nfs_have_delegation(inode, FMODE_READ)) 1115 goto out_set_verifier; 1116 1117 /* Force a full look up iff the parent directory has changed */ 1118 if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) { 1119 if (nfs_lookup_verify_inode(inode, nd)) 1120 goto out_zap_parent; 1121 goto out_valid; 1122 } 1123 1124 if (NFS_STALE(inode)) 1125 goto out_bad; 1126 1127 error = -ENOMEM; 1128 fhandle = nfs_alloc_fhandle(); 1129 fattr = nfs_alloc_fattr(); 1130 if (fhandle == NULL || fattr == NULL) 1131 goto out_error; 1132 1133 error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); 1134 if (error) 1135 goto out_bad; 1136 if (nfs_compare_fh(NFS_FH(inode), fhandle)) 1137 goto out_bad; 1138 if ((error = nfs_refresh_inode(inode, fattr)) != 0) 1139 goto out_bad; 1140 1141 nfs_free_fattr(fattr); 1142 nfs_free_fhandle(fhandle); 1143 out_set_verifier: 1144 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1145 out_valid: 1146 dput(parent); 1147 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n", 1148 __func__, dentry->d_parent->d_name.name, 1149 dentry->d_name.name); 1150 return 1; 1151 out_zap_parent: 1152 nfs_zap_caches(dir); 1153 out_bad: 1154 nfs_mark_for_revalidate(dir); 1155 if (inode && S_ISDIR(inode->i_mode)) { 1156 /* Purge readdir caches. */ 1157 nfs_zap_caches(inode); 1158 /* If we have submounts, don't unhash ! */ 1159 if (have_submounts(dentry)) 1160 goto out_valid; 1161 if (dentry->d_flags & DCACHE_DISCONNECTED) 1162 goto out_valid; 1163 shrink_dcache_parent(dentry); 1164 } 1165 d_drop(dentry); 1166 nfs_free_fattr(fattr); 1167 nfs_free_fhandle(fhandle); 1168 dput(parent); 1169 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", 1170 __func__, dentry->d_parent->d_name.name, 1171 dentry->d_name.name); 1172 return 0; 1173 out_error: 1174 nfs_free_fattr(fattr); 1175 nfs_free_fhandle(fhandle); 1176 dput(parent); 1177 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n", 1178 __func__, dentry->d_parent->d_name.name, 1179 dentry->d_name.name, error); 1180 return error; 1181 } 1182 1183 /* 1184 * This is called from dput() when d_count is going to 0. 1185 */ 1186 static int nfs_dentry_delete(const struct dentry *dentry) 1187 { 1188 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", 1189 dentry->d_parent->d_name.name, dentry->d_name.name, 1190 dentry->d_flags); 1191 1192 /* Unhash any dentry with a stale inode */ 1193 if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode)) 1194 return 1; 1195 1196 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 1197 /* Unhash it, so that ->d_iput() would be called */ 1198 return 1; 1199 } 1200 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) { 1201 /* Unhash it, so that ancestors of killed async unlink 1202 * files will be cleaned up during umount */ 1203 return 1; 1204 } 1205 return 0; 1206 1207 } 1208 1209 static void nfs_drop_nlink(struct inode *inode) 1210 { 1211 spin_lock(&inode->i_lock); 1212 if (inode->i_nlink > 0) 1213 drop_nlink(inode); 1214 spin_unlock(&inode->i_lock); 1215 } 1216 1217 /* 1218 * Called when the dentry loses inode. 1219 * We use it to clean up silly-renamed files. 1220 */ 1221 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) 1222 { 1223 if (S_ISDIR(inode->i_mode)) 1224 /* drop any readdir cache as it could easily be old */ 1225 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA; 1226 1227 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 1228 drop_nlink(inode); 1229 nfs_complete_unlink(dentry, inode); 1230 } 1231 iput(inode); 1232 } 1233 1234 static void nfs_d_release(struct dentry *dentry) 1235 { 1236 /* free cached devname value, if it survived that far */ 1237 if (unlikely(dentry->d_fsdata)) { 1238 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) 1239 WARN_ON(1); 1240 else 1241 kfree(dentry->d_fsdata); 1242 } 1243 } 1244 1245 const struct dentry_operations nfs_dentry_operations = { 1246 .d_revalidate = nfs_lookup_revalidate, 1247 .d_delete = nfs_dentry_delete, 1248 .d_iput = nfs_dentry_iput, 1249 .d_automount = nfs_d_automount, 1250 .d_release = nfs_d_release, 1251 }; 1252 1253 static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 1254 { 1255 struct dentry *res; 1256 struct dentry *parent; 1257 struct inode *inode = NULL; 1258 struct nfs_fh *fhandle = NULL; 1259 struct nfs_fattr *fattr = NULL; 1260 int error; 1261 1262 dfprintk(VFS, "NFS: lookup(%s/%s)\n", 1263 dentry->d_parent->d_name.name, dentry->d_name.name); 1264 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); 1265 1266 res = ERR_PTR(-ENAMETOOLONG); 1267 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) 1268 goto out; 1269 1270 /* 1271 * If we're doing an exclusive create, optimize away the lookup 1272 * but don't hash the dentry. 1273 */ 1274 if (nfs_is_exclusive_create(dir, nd)) { 1275 d_instantiate(dentry, NULL); 1276 res = NULL; 1277 goto out; 1278 } 1279 1280 res = ERR_PTR(-ENOMEM); 1281 fhandle = nfs_alloc_fhandle(); 1282 fattr = nfs_alloc_fattr(); 1283 if (fhandle == NULL || fattr == NULL) 1284 goto out; 1285 1286 parent = dentry->d_parent; 1287 /* Protect against concurrent sillydeletes */ 1288 nfs_block_sillyrename(parent); 1289 error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); 1290 if (error == -ENOENT) 1291 goto no_entry; 1292 if (error < 0) { 1293 res = ERR_PTR(error); 1294 goto out_unblock_sillyrename; 1295 } 1296 inode = nfs_fhget(dentry->d_sb, fhandle, fattr); 1297 res = ERR_CAST(inode); 1298 if (IS_ERR(res)) 1299 goto out_unblock_sillyrename; 1300 1301 no_entry: 1302 res = d_materialise_unique(dentry, inode); 1303 if (res != NULL) { 1304 if (IS_ERR(res)) 1305 goto out_unblock_sillyrename; 1306 dentry = res; 1307 } 1308 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1309 out_unblock_sillyrename: 1310 nfs_unblock_sillyrename(parent); 1311 out: 1312 nfs_free_fattr(fattr); 1313 nfs_free_fhandle(fhandle); 1314 return res; 1315 } 1316 1317 #ifdef CONFIG_NFS_V4 1318 static int nfs_open_revalidate(struct dentry *, struct nameidata *); 1319 1320 const struct dentry_operations nfs4_dentry_operations = { 1321 .d_revalidate = nfs_open_revalidate, 1322 .d_delete = nfs_dentry_delete, 1323 .d_iput = nfs_dentry_iput, 1324 .d_automount = nfs_d_automount, 1325 .d_release = nfs_d_release, 1326 }; 1327 1328 /* 1329 * Use intent information to determine whether we need to substitute 1330 * the NFSv4-style stateful OPEN for the LOOKUP call 1331 */ 1332 static int is_atomic_open(struct nameidata *nd) 1333 { 1334 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0) 1335 return 0; 1336 /* NFS does not (yet) have a stateful open for directories */ 1337 if (nd->flags & LOOKUP_DIRECTORY) 1338 return 0; 1339 /* Are we trying to write to a read only partition? */ 1340 if (__mnt_is_readonly(nd->path.mnt) && 1341 (nd->intent.open.flags & (O_CREAT|O_TRUNC|O_ACCMODE))) 1342 return 0; 1343 return 1; 1344 } 1345 1346 static fmode_t flags_to_mode(int flags) 1347 { 1348 fmode_t res = (__force fmode_t)flags & FMODE_EXEC; 1349 if ((flags & O_ACCMODE) != O_WRONLY) 1350 res |= FMODE_READ; 1351 if ((flags & O_ACCMODE) != O_RDONLY) 1352 res |= FMODE_WRITE; 1353 return res; 1354 } 1355 1356 static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags) 1357 { 1358 struct nfs_open_context *ctx; 1359 struct rpc_cred *cred; 1360 fmode_t fmode = flags_to_mode(open_flags); 1361 1362 cred = rpc_lookup_cred(); 1363 if (IS_ERR(cred)) 1364 return ERR_CAST(cred); 1365 ctx = alloc_nfs_open_context(dentry, cred, fmode); 1366 put_rpccred(cred); 1367 if (ctx == NULL) 1368 return ERR_PTR(-ENOMEM); 1369 return ctx; 1370 } 1371 1372 static int do_open(struct inode *inode, struct file *filp) 1373 { 1374 nfs_fscache_set_inode_cookie(inode, filp); 1375 return 0; 1376 } 1377 1378 static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx) 1379 { 1380 struct file *filp; 1381 int ret = 0; 1382 1383 /* If the open_intent is for execute, we have an extra check to make */ 1384 if (ctx->mode & FMODE_EXEC) { 1385 ret = nfs_may_open(ctx->dentry->d_inode, 1386 ctx->cred, 1387 nd->intent.open.flags); 1388 if (ret < 0) 1389 goto out; 1390 } 1391 filp = lookup_instantiate_filp(nd, ctx->dentry, do_open); 1392 if (IS_ERR(filp)) 1393 ret = PTR_ERR(filp); 1394 else 1395 nfs_file_set_open_context(filp, ctx); 1396 out: 1397 put_nfs_open_context(ctx); 1398 return ret; 1399 } 1400 1401 static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) 1402 { 1403 struct nfs_open_context *ctx; 1404 struct iattr attr; 1405 struct dentry *res = NULL; 1406 struct inode *inode; 1407 int open_flags; 1408 int err; 1409 1410 dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n", 1411 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1412 1413 /* Check that we are indeed trying to open this file */ 1414 if (!is_atomic_open(nd)) 1415 goto no_open; 1416 1417 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) { 1418 res = ERR_PTR(-ENAMETOOLONG); 1419 goto out; 1420 } 1421 1422 /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash 1423 * the dentry. */ 1424 if (nd->flags & LOOKUP_EXCL) { 1425 d_instantiate(dentry, NULL); 1426 goto out; 1427 } 1428 1429 open_flags = nd->intent.open.flags; 1430 1431 ctx = create_nfs_open_context(dentry, open_flags); 1432 res = ERR_CAST(ctx); 1433 if (IS_ERR(ctx)) 1434 goto out; 1435 1436 if (nd->flags & LOOKUP_CREATE) { 1437 attr.ia_mode = nd->intent.open.create_mode; 1438 attr.ia_valid = ATTR_MODE; 1439 attr.ia_mode &= ~current_umask(); 1440 } else { 1441 open_flags &= ~(O_EXCL | O_CREAT); 1442 attr.ia_valid = 0; 1443 } 1444 1445 /* Open the file on the server */ 1446 nfs_block_sillyrename(dentry->d_parent); 1447 inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr); 1448 if (IS_ERR(inode)) { 1449 nfs_unblock_sillyrename(dentry->d_parent); 1450 put_nfs_open_context(ctx); 1451 switch (PTR_ERR(inode)) { 1452 /* Make a negative dentry */ 1453 case -ENOENT: 1454 d_add(dentry, NULL); 1455 res = NULL; 1456 goto out; 1457 /* This turned out not to be a regular file */ 1458 case -ENOTDIR: 1459 goto no_open; 1460 case -ELOOP: 1461 if (!(nd->intent.open.flags & O_NOFOLLOW)) 1462 goto no_open; 1463 /* case -EISDIR: */ 1464 /* case -EINVAL: */ 1465 default: 1466 res = ERR_CAST(inode); 1467 goto out; 1468 } 1469 } 1470 res = d_add_unique(dentry, inode); 1471 nfs_unblock_sillyrename(dentry->d_parent); 1472 if (res != NULL) { 1473 dput(ctx->dentry); 1474 ctx->dentry = dget(res); 1475 dentry = res; 1476 } 1477 err = nfs_intent_set_file(nd, ctx); 1478 if (err < 0) { 1479 if (res != NULL) 1480 dput(res); 1481 return ERR_PTR(err); 1482 } 1483 out: 1484 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1485 return res; 1486 no_open: 1487 return nfs_lookup(dir, dentry, nd); 1488 } 1489 1490 static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) 1491 { 1492 struct dentry *parent = NULL; 1493 struct inode *inode; 1494 struct inode *dir; 1495 struct nfs_open_context *ctx; 1496 int openflags, ret = 0; 1497 1498 if (nd->flags & LOOKUP_RCU) 1499 return -ECHILD; 1500 1501 inode = dentry->d_inode; 1502 if (!is_atomic_open(nd) || d_mountpoint(dentry)) 1503 goto no_open; 1504 1505 parent = dget_parent(dentry); 1506 dir = parent->d_inode; 1507 1508 /* We can't create new files in nfs_open_revalidate(), so we 1509 * optimize away revalidation of negative dentries. 1510 */ 1511 if (inode == NULL) { 1512 if (!nfs_neg_need_reval(dir, dentry, nd)) 1513 ret = 1; 1514 goto out; 1515 } 1516 1517 /* NFS only supports OPEN on regular files */ 1518 if (!S_ISREG(inode->i_mode)) 1519 goto no_open_dput; 1520 openflags = nd->intent.open.flags; 1521 /* We cannot do exclusive creation on a positive dentry */ 1522 if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) 1523 goto no_open_dput; 1524 /* We can't create new files, or truncate existing ones here */ 1525 openflags &= ~(O_CREAT|O_EXCL|O_TRUNC); 1526 1527 ctx = create_nfs_open_context(dentry, openflags); 1528 ret = PTR_ERR(ctx); 1529 if (IS_ERR(ctx)) 1530 goto out; 1531 /* 1532 * Note: we're not holding inode->i_mutex and so may be racing with 1533 * operations that change the directory. We therefore save the 1534 * change attribute *before* we do the RPC call. 1535 */ 1536 inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, NULL); 1537 if (IS_ERR(inode)) { 1538 ret = PTR_ERR(inode); 1539 switch (ret) { 1540 case -EPERM: 1541 case -EACCES: 1542 case -EDQUOT: 1543 case -ENOSPC: 1544 case -EROFS: 1545 goto out_put_ctx; 1546 default: 1547 goto out_drop; 1548 } 1549 } 1550 iput(inode); 1551 if (inode != dentry->d_inode) 1552 goto out_drop; 1553 1554 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1555 ret = nfs_intent_set_file(nd, ctx); 1556 if (ret >= 0) 1557 ret = 1; 1558 out: 1559 dput(parent); 1560 return ret; 1561 out_drop: 1562 d_drop(dentry); 1563 ret = 0; 1564 out_put_ctx: 1565 put_nfs_open_context(ctx); 1566 goto out; 1567 1568 no_open_dput: 1569 dput(parent); 1570 no_open: 1571 return nfs_lookup_revalidate(dentry, nd); 1572 } 1573 1574 static int nfs_open_create(struct inode *dir, struct dentry *dentry, int mode, 1575 struct nameidata *nd) 1576 { 1577 struct nfs_open_context *ctx = NULL; 1578 struct iattr attr; 1579 int error; 1580 int open_flags = O_CREAT|O_EXCL; 1581 1582 dfprintk(VFS, "NFS: create(%s/%ld), %s\n", 1583 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1584 1585 attr.ia_mode = mode; 1586 attr.ia_valid = ATTR_MODE; 1587 1588 if (nd && (nd->flags & LOOKUP_OPEN) != 0) 1589 open_flags = nd->intent.open.flags; 1590 1591 ctx = create_nfs_open_context(dentry, open_flags); 1592 error = PTR_ERR(ctx); 1593 if (IS_ERR(ctx)) 1594 goto out_err_drop; 1595 1596 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx); 1597 if (error != 0) 1598 goto out_put_ctx; 1599 if (nd && (nd->flags & LOOKUP_OPEN) != 0) { 1600 error = nfs_intent_set_file(nd, ctx); 1601 if (error < 0) 1602 goto out_err; 1603 } else { 1604 put_nfs_open_context(ctx); 1605 } 1606 return 0; 1607 out_put_ctx: 1608 put_nfs_open_context(ctx); 1609 out_err_drop: 1610 d_drop(dentry); 1611 out_err: 1612 return error; 1613 } 1614 1615 #endif /* CONFIG_NFSV4 */ 1616 1617 /* 1618 * Code common to create, mkdir, and mknod. 1619 */ 1620 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, 1621 struct nfs_fattr *fattr) 1622 { 1623 struct dentry *parent = dget_parent(dentry); 1624 struct inode *dir = parent->d_inode; 1625 struct inode *inode; 1626 int error = -EACCES; 1627 1628 d_drop(dentry); 1629 1630 /* We may have been initialized further down */ 1631 if (dentry->d_inode) 1632 goto out; 1633 if (fhandle->size == 0) { 1634 error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); 1635 if (error) 1636 goto out_error; 1637 } 1638 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1639 if (!(fattr->valid & NFS_ATTR_FATTR)) { 1640 struct nfs_server *server = NFS_SB(dentry->d_sb); 1641 error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr); 1642 if (error < 0) 1643 goto out_error; 1644 } 1645 inode = nfs_fhget(dentry->d_sb, fhandle, fattr); 1646 error = PTR_ERR(inode); 1647 if (IS_ERR(inode)) 1648 goto out_error; 1649 d_add(dentry, inode); 1650 out: 1651 dput(parent); 1652 return 0; 1653 out_error: 1654 nfs_mark_for_revalidate(dir); 1655 dput(parent); 1656 return error; 1657 } 1658 1659 /* 1660 * Following a failed create operation, we drop the dentry rather 1661 * than retain a negative dentry. This avoids a problem in the event 1662 * that the operation succeeded on the server, but an error in the 1663 * reply path made it appear to have failed. 1664 */ 1665 static int nfs_create(struct inode *dir, struct dentry *dentry, int mode, 1666 struct nameidata *nd) 1667 { 1668 struct iattr attr; 1669 int error; 1670 int open_flags = O_CREAT|O_EXCL; 1671 1672 dfprintk(VFS, "NFS: create(%s/%ld), %s\n", 1673 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1674 1675 attr.ia_mode = mode; 1676 attr.ia_valid = ATTR_MODE; 1677 1678 if (nd && (nd->flags & LOOKUP_OPEN) != 0) 1679 open_flags = nd->intent.open.flags; 1680 1681 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, NULL); 1682 if (error != 0) 1683 goto out_err; 1684 return 0; 1685 out_err: 1686 d_drop(dentry); 1687 return error; 1688 } 1689 1690 /* 1691 * See comments for nfs_proc_create regarding failed operations. 1692 */ 1693 static int 1694 nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev) 1695 { 1696 struct iattr attr; 1697 int status; 1698 1699 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n", 1700 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1701 1702 if (!new_valid_dev(rdev)) 1703 return -EINVAL; 1704 1705 attr.ia_mode = mode; 1706 attr.ia_valid = ATTR_MODE; 1707 1708 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); 1709 if (status != 0) 1710 goto out_err; 1711 return 0; 1712 out_err: 1713 d_drop(dentry); 1714 return status; 1715 } 1716 1717 /* 1718 * See comments for nfs_proc_create regarding failed operations. 1719 */ 1720 static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 1721 { 1722 struct iattr attr; 1723 int error; 1724 1725 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n", 1726 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1727 1728 attr.ia_valid = ATTR_MODE; 1729 attr.ia_mode = mode | S_IFDIR; 1730 1731 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); 1732 if (error != 0) 1733 goto out_err; 1734 return 0; 1735 out_err: 1736 d_drop(dentry); 1737 return error; 1738 } 1739 1740 static void nfs_dentry_handle_enoent(struct dentry *dentry) 1741 { 1742 if (dentry->d_inode != NULL && !d_unhashed(dentry)) 1743 d_delete(dentry); 1744 } 1745 1746 static int nfs_rmdir(struct inode *dir, struct dentry *dentry) 1747 { 1748 int error; 1749 1750 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n", 1751 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1752 1753 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); 1754 /* Ensure the VFS deletes this inode */ 1755 if (error == 0 && dentry->d_inode != NULL) 1756 clear_nlink(dentry->d_inode); 1757 else if (error == -ENOENT) 1758 nfs_dentry_handle_enoent(dentry); 1759 1760 return error; 1761 } 1762 1763 /* 1764 * Remove a file after making sure there are no pending writes, 1765 * and after checking that the file has only one user. 1766 * 1767 * We invalidate the attribute cache and free the inode prior to the operation 1768 * to avoid possible races if the server reuses the inode. 1769 */ 1770 static int nfs_safe_remove(struct dentry *dentry) 1771 { 1772 struct inode *dir = dentry->d_parent->d_inode; 1773 struct inode *inode = dentry->d_inode; 1774 int error = -EBUSY; 1775 1776 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n", 1777 dentry->d_parent->d_name.name, dentry->d_name.name); 1778 1779 /* If the dentry was sillyrenamed, we simply call d_delete() */ 1780 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 1781 error = 0; 1782 goto out; 1783 } 1784 1785 if (inode != NULL) { 1786 nfs_inode_return_delegation(inode); 1787 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); 1788 /* The VFS may want to delete this inode */ 1789 if (error == 0) 1790 nfs_drop_nlink(inode); 1791 nfs_mark_for_revalidate(inode); 1792 } else 1793 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); 1794 if (error == -ENOENT) 1795 nfs_dentry_handle_enoent(dentry); 1796 out: 1797 return error; 1798 } 1799 1800 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode 1801 * belongs to an active ".nfs..." file and we return -EBUSY. 1802 * 1803 * If sillyrename() returns 0, we do nothing, otherwise we unlink. 1804 */ 1805 static int nfs_unlink(struct inode *dir, struct dentry *dentry) 1806 { 1807 int error; 1808 int need_rehash = 0; 1809 1810 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, 1811 dir->i_ino, dentry->d_name.name); 1812 1813 spin_lock(&dentry->d_lock); 1814 if (dentry->d_count > 1) { 1815 spin_unlock(&dentry->d_lock); 1816 /* Start asynchronous writeout of the inode */ 1817 write_inode_now(dentry->d_inode, 0); 1818 error = nfs_sillyrename(dir, dentry); 1819 return error; 1820 } 1821 if (!d_unhashed(dentry)) { 1822 __d_drop(dentry); 1823 need_rehash = 1; 1824 } 1825 spin_unlock(&dentry->d_lock); 1826 error = nfs_safe_remove(dentry); 1827 if (!error || error == -ENOENT) { 1828 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1829 } else if (need_rehash) 1830 d_rehash(dentry); 1831 return error; 1832 } 1833 1834 /* 1835 * To create a symbolic link, most file systems instantiate a new inode, 1836 * add a page to it containing the path, then write it out to the disk 1837 * using prepare_write/commit_write. 1838 * 1839 * Unfortunately the NFS client can't create the in-core inode first 1840 * because it needs a file handle to create an in-core inode (see 1841 * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the 1842 * symlink request has completed on the server. 1843 * 1844 * So instead we allocate a raw page, copy the symname into it, then do 1845 * the SYMLINK request with the page as the buffer. If it succeeds, we 1846 * now have a new file handle and can instantiate an in-core NFS inode 1847 * and move the raw page into its mapping. 1848 */ 1849 static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) 1850 { 1851 struct pagevec lru_pvec; 1852 struct page *page; 1853 char *kaddr; 1854 struct iattr attr; 1855 unsigned int pathlen = strlen(symname); 1856 int error; 1857 1858 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id, 1859 dir->i_ino, dentry->d_name.name, symname); 1860 1861 if (pathlen > PAGE_SIZE) 1862 return -ENAMETOOLONG; 1863 1864 attr.ia_mode = S_IFLNK | S_IRWXUGO; 1865 attr.ia_valid = ATTR_MODE; 1866 1867 page = alloc_page(GFP_HIGHUSER); 1868 if (!page) 1869 return -ENOMEM; 1870 1871 kaddr = kmap_atomic(page, KM_USER0); 1872 memcpy(kaddr, symname, pathlen); 1873 if (pathlen < PAGE_SIZE) 1874 memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); 1875 kunmap_atomic(kaddr, KM_USER0); 1876 1877 error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); 1878 if (error != 0) { 1879 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n", 1880 dir->i_sb->s_id, dir->i_ino, 1881 dentry->d_name.name, symname, error); 1882 d_drop(dentry); 1883 __free_page(page); 1884 return error; 1885 } 1886 1887 /* 1888 * No big deal if we can't add this page to the page cache here. 1889 * READLINK will get the missing page from the server if needed. 1890 */ 1891 pagevec_init(&lru_pvec, 0); 1892 if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0, 1893 GFP_KERNEL)) { 1894 pagevec_add(&lru_pvec, page); 1895 pagevec_lru_add_file(&lru_pvec); 1896 SetPageUptodate(page); 1897 unlock_page(page); 1898 } else 1899 __free_page(page); 1900 1901 return 0; 1902 } 1903 1904 static int 1905 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) 1906 { 1907 struct inode *inode = old_dentry->d_inode; 1908 int error; 1909 1910 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n", 1911 old_dentry->d_parent->d_name.name, old_dentry->d_name.name, 1912 dentry->d_parent->d_name.name, dentry->d_name.name); 1913 1914 nfs_inode_return_delegation(inode); 1915 1916 d_drop(dentry); 1917 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); 1918 if (error == 0) { 1919 ihold(inode); 1920 d_add(dentry, inode); 1921 } 1922 return error; 1923 } 1924 1925 /* 1926 * RENAME 1927 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a 1928 * different file handle for the same inode after a rename (e.g. when 1929 * moving to a different directory). A fail-safe method to do so would 1930 * be to look up old_dir/old_name, create a link to new_dir/new_name and 1931 * rename the old file using the sillyrename stuff. This way, the original 1932 * file in old_dir will go away when the last process iput()s the inode. 1933 * 1934 * FIXED. 1935 * 1936 * It actually works quite well. One needs to have the possibility for 1937 * at least one ".nfs..." file in each directory the file ever gets 1938 * moved or linked to which happens automagically with the new 1939 * implementation that only depends on the dcache stuff instead of 1940 * using the inode layer 1941 * 1942 * Unfortunately, things are a little more complicated than indicated 1943 * above. For a cross-directory move, we want to make sure we can get 1944 * rid of the old inode after the operation. This means there must be 1945 * no pending writes (if it's a file), and the use count must be 1. 1946 * If these conditions are met, we can drop the dentries before doing 1947 * the rename. 1948 */ 1949 static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, 1950 struct inode *new_dir, struct dentry *new_dentry) 1951 { 1952 struct inode *old_inode = old_dentry->d_inode; 1953 struct inode *new_inode = new_dentry->d_inode; 1954 struct dentry *dentry = NULL, *rehash = NULL; 1955 int error = -EBUSY; 1956 1957 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", 1958 old_dentry->d_parent->d_name.name, old_dentry->d_name.name, 1959 new_dentry->d_parent->d_name.name, new_dentry->d_name.name, 1960 new_dentry->d_count); 1961 1962 /* 1963 * For non-directories, check whether the target is busy and if so, 1964 * make a copy of the dentry and then do a silly-rename. If the 1965 * silly-rename succeeds, the copied dentry is hashed and becomes 1966 * the new target. 1967 */ 1968 if (new_inode && !S_ISDIR(new_inode->i_mode)) { 1969 /* 1970 * To prevent any new references to the target during the 1971 * rename, we unhash the dentry in advance. 1972 */ 1973 if (!d_unhashed(new_dentry)) { 1974 d_drop(new_dentry); 1975 rehash = new_dentry; 1976 } 1977 1978 if (new_dentry->d_count > 2) { 1979 int err; 1980 1981 /* copy the target dentry's name */ 1982 dentry = d_alloc(new_dentry->d_parent, 1983 &new_dentry->d_name); 1984 if (!dentry) 1985 goto out; 1986 1987 /* silly-rename the existing target ... */ 1988 err = nfs_sillyrename(new_dir, new_dentry); 1989 if (err) 1990 goto out; 1991 1992 new_dentry = dentry; 1993 rehash = NULL; 1994 new_inode = NULL; 1995 } 1996 } 1997 1998 nfs_inode_return_delegation(old_inode); 1999 if (new_inode != NULL) 2000 nfs_inode_return_delegation(new_inode); 2001 2002 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name, 2003 new_dir, &new_dentry->d_name); 2004 nfs_mark_for_revalidate(old_inode); 2005 out: 2006 if (rehash) 2007 d_rehash(rehash); 2008 if (!error) { 2009 if (new_inode != NULL) 2010 nfs_drop_nlink(new_inode); 2011 d_move(old_dentry, new_dentry); 2012 nfs_set_verifier(new_dentry, 2013 nfs_save_change_attribute(new_dir)); 2014 } else if (error == -ENOENT) 2015 nfs_dentry_handle_enoent(old_dentry); 2016 2017 /* new dentry created? */ 2018 if (dentry) 2019 dput(dentry); 2020 return error; 2021 } 2022 2023 static DEFINE_SPINLOCK(nfs_access_lru_lock); 2024 static LIST_HEAD(nfs_access_lru_list); 2025 static atomic_long_t nfs_access_nr_entries; 2026 2027 static void nfs_access_free_entry(struct nfs_access_entry *entry) 2028 { 2029 put_rpccred(entry->cred); 2030 kfree(entry); 2031 smp_mb__before_atomic_dec(); 2032 atomic_long_dec(&nfs_access_nr_entries); 2033 smp_mb__after_atomic_dec(); 2034 } 2035 2036 static void nfs_access_free_list(struct list_head *head) 2037 { 2038 struct nfs_access_entry *cache; 2039 2040 while (!list_empty(head)) { 2041 cache = list_entry(head->next, struct nfs_access_entry, lru); 2042 list_del(&cache->lru); 2043 nfs_access_free_entry(cache); 2044 } 2045 } 2046 2047 int nfs_access_cache_shrinker(struct shrinker *shrink, 2048 struct shrink_control *sc) 2049 { 2050 LIST_HEAD(head); 2051 struct nfs_inode *nfsi, *next; 2052 struct nfs_access_entry *cache; 2053 int nr_to_scan = sc->nr_to_scan; 2054 gfp_t gfp_mask = sc->gfp_mask; 2055 2056 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL) 2057 return (nr_to_scan == 0) ? 0 : -1; 2058 2059 spin_lock(&nfs_access_lru_lock); 2060 list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) { 2061 struct inode *inode; 2062 2063 if (nr_to_scan-- == 0) 2064 break; 2065 inode = &nfsi->vfs_inode; 2066 spin_lock(&inode->i_lock); 2067 if (list_empty(&nfsi->access_cache_entry_lru)) 2068 goto remove_lru_entry; 2069 cache = list_entry(nfsi->access_cache_entry_lru.next, 2070 struct nfs_access_entry, lru); 2071 list_move(&cache->lru, &head); 2072 rb_erase(&cache->rb_node, &nfsi->access_cache); 2073 if (!list_empty(&nfsi->access_cache_entry_lru)) 2074 list_move_tail(&nfsi->access_cache_inode_lru, 2075 &nfs_access_lru_list); 2076 else { 2077 remove_lru_entry: 2078 list_del_init(&nfsi->access_cache_inode_lru); 2079 smp_mb__before_clear_bit(); 2080 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); 2081 smp_mb__after_clear_bit(); 2082 } 2083 spin_unlock(&inode->i_lock); 2084 } 2085 spin_unlock(&nfs_access_lru_lock); 2086 nfs_access_free_list(&head); 2087 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; 2088 } 2089 2090 static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head) 2091 { 2092 struct rb_root *root_node = &nfsi->access_cache; 2093 struct rb_node *n; 2094 struct nfs_access_entry *entry; 2095 2096 /* Unhook entries from the cache */ 2097 while ((n = rb_first(root_node)) != NULL) { 2098 entry = rb_entry(n, struct nfs_access_entry, rb_node); 2099 rb_erase(n, root_node); 2100 list_move(&entry->lru, head); 2101 } 2102 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; 2103 } 2104 2105 void nfs_access_zap_cache(struct inode *inode) 2106 { 2107 LIST_HEAD(head); 2108 2109 if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0) 2110 return; 2111 /* Remove from global LRU init */ 2112 spin_lock(&nfs_access_lru_lock); 2113 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) 2114 list_del_init(&NFS_I(inode)->access_cache_inode_lru); 2115 2116 spin_lock(&inode->i_lock); 2117 __nfs_access_zap_cache(NFS_I(inode), &head); 2118 spin_unlock(&inode->i_lock); 2119 spin_unlock(&nfs_access_lru_lock); 2120 nfs_access_free_list(&head); 2121 } 2122 2123 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred) 2124 { 2125 struct rb_node *n = NFS_I(inode)->access_cache.rb_node; 2126 struct nfs_access_entry *entry; 2127 2128 while (n != NULL) { 2129 entry = rb_entry(n, struct nfs_access_entry, rb_node); 2130 2131 if (cred < entry->cred) 2132 n = n->rb_left; 2133 else if (cred > entry->cred) 2134 n = n->rb_right; 2135 else 2136 return entry; 2137 } 2138 return NULL; 2139 } 2140 2141 static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) 2142 { 2143 struct nfs_inode *nfsi = NFS_I(inode); 2144 struct nfs_access_entry *cache; 2145 int err = -ENOENT; 2146 2147 spin_lock(&inode->i_lock); 2148 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) 2149 goto out_zap; 2150 cache = nfs_access_search_rbtree(inode, cred); 2151 if (cache == NULL) 2152 goto out; 2153 if (!nfs_have_delegated_attributes(inode) && 2154 !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo)) 2155 goto out_stale; 2156 res->jiffies = cache->jiffies; 2157 res->cred = cache->cred; 2158 res->mask = cache->mask; 2159 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); 2160 err = 0; 2161 out: 2162 spin_unlock(&inode->i_lock); 2163 return err; 2164 out_stale: 2165 rb_erase(&cache->rb_node, &nfsi->access_cache); 2166 list_del(&cache->lru); 2167 spin_unlock(&inode->i_lock); 2168 nfs_access_free_entry(cache); 2169 return -ENOENT; 2170 out_zap: 2171 spin_unlock(&inode->i_lock); 2172 nfs_access_zap_cache(inode); 2173 return -ENOENT; 2174 } 2175 2176 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) 2177 { 2178 struct nfs_inode *nfsi = NFS_I(inode); 2179 struct rb_root *root_node = &nfsi->access_cache; 2180 struct rb_node **p = &root_node->rb_node; 2181 struct rb_node *parent = NULL; 2182 struct nfs_access_entry *entry; 2183 2184 spin_lock(&inode->i_lock); 2185 while (*p != NULL) { 2186 parent = *p; 2187 entry = rb_entry(parent, struct nfs_access_entry, rb_node); 2188 2189 if (set->cred < entry->cred) 2190 p = &parent->rb_left; 2191 else if (set->cred > entry->cred) 2192 p = &parent->rb_right; 2193 else 2194 goto found; 2195 } 2196 rb_link_node(&set->rb_node, parent, p); 2197 rb_insert_color(&set->rb_node, root_node); 2198 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); 2199 spin_unlock(&inode->i_lock); 2200 return; 2201 found: 2202 rb_replace_node(parent, &set->rb_node, root_node); 2203 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); 2204 list_del(&entry->lru); 2205 spin_unlock(&inode->i_lock); 2206 nfs_access_free_entry(entry); 2207 } 2208 2209 static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) 2210 { 2211 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); 2212 if (cache == NULL) 2213 return; 2214 RB_CLEAR_NODE(&cache->rb_node); 2215 cache->jiffies = set->jiffies; 2216 cache->cred = get_rpccred(set->cred); 2217 cache->mask = set->mask; 2218 2219 nfs_access_add_rbtree(inode, cache); 2220 2221 /* Update accounting */ 2222 smp_mb__before_atomic_inc(); 2223 atomic_long_inc(&nfs_access_nr_entries); 2224 smp_mb__after_atomic_inc(); 2225 2226 /* Add inode to global LRU list */ 2227 if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { 2228 spin_lock(&nfs_access_lru_lock); 2229 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) 2230 list_add_tail(&NFS_I(inode)->access_cache_inode_lru, 2231 &nfs_access_lru_list); 2232 spin_unlock(&nfs_access_lru_lock); 2233 } 2234 } 2235 2236 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) 2237 { 2238 struct nfs_access_entry cache; 2239 int status; 2240 2241 status = nfs_access_get_cached(inode, cred, &cache); 2242 if (status == 0) 2243 goto out; 2244 2245 /* Be clever: ask server to check for all possible rights */ 2246 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; 2247 cache.cred = cred; 2248 cache.jiffies = jiffies; 2249 status = NFS_PROTO(inode)->access(inode, &cache); 2250 if (status != 0) { 2251 if (status == -ESTALE) { 2252 nfs_zap_caches(inode); 2253 if (!S_ISDIR(inode->i_mode)) 2254 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); 2255 } 2256 return status; 2257 } 2258 nfs_access_add_cache(inode, &cache); 2259 out: 2260 if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) 2261 return 0; 2262 return -EACCES; 2263 } 2264 2265 static int nfs_open_permission_mask(int openflags) 2266 { 2267 int mask = 0; 2268 2269 if ((openflags & O_ACCMODE) != O_WRONLY) 2270 mask |= MAY_READ; 2271 if ((openflags & O_ACCMODE) != O_RDONLY) 2272 mask |= MAY_WRITE; 2273 if (openflags & __FMODE_EXEC) 2274 mask |= MAY_EXEC; 2275 return mask; 2276 } 2277 2278 int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) 2279 { 2280 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); 2281 } 2282 2283 int nfs_permission(struct inode *inode, int mask) 2284 { 2285 struct rpc_cred *cred; 2286 int res = 0; 2287 2288 if (mask & MAY_NOT_BLOCK) 2289 return -ECHILD; 2290 2291 nfs_inc_stats(inode, NFSIOS_VFSACCESS); 2292 2293 if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) 2294 goto out; 2295 /* Is this sys_access() ? */ 2296 if (mask & (MAY_ACCESS | MAY_CHDIR)) 2297 goto force_lookup; 2298 2299 switch (inode->i_mode & S_IFMT) { 2300 case S_IFLNK: 2301 goto out; 2302 case S_IFREG: 2303 /* NFSv4 has atomic_open... */ 2304 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) 2305 && (mask & MAY_OPEN) 2306 && !(mask & MAY_EXEC)) 2307 goto out; 2308 break; 2309 case S_IFDIR: 2310 /* 2311 * Optimize away all write operations, since the server 2312 * will check permissions when we perform the op. 2313 */ 2314 if ((mask & MAY_WRITE) && !(mask & MAY_READ)) 2315 goto out; 2316 } 2317 2318 force_lookup: 2319 if (!NFS_PROTO(inode)->access) 2320 goto out_notsup; 2321 2322 cred = rpc_lookup_cred(); 2323 if (!IS_ERR(cred)) { 2324 res = nfs_do_access(inode, cred, mask); 2325 put_rpccred(cred); 2326 } else 2327 res = PTR_ERR(cred); 2328 out: 2329 if (!res && (mask & MAY_EXEC) && !execute_ok(inode)) 2330 res = -EACCES; 2331 2332 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n", 2333 inode->i_sb->s_id, inode->i_ino, mask, res); 2334 return res; 2335 out_notsup: 2336 res = nfs_revalidate_inode(NFS_SERVER(inode), inode); 2337 if (res == 0) 2338 res = generic_permission(inode, mask); 2339 goto out; 2340 } 2341 2342 /* 2343 * Local variables: 2344 * version-control: t 2345 * kept-new-versions: 5 2346 * End: 2347 */ 2348