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