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|FMODE_WRITE))) 1342 return 0; 1343 return 1; 1344 } 1345 1346 static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags) 1347 { 1348 struct nfs_open_context *ctx; 1349 struct rpc_cred *cred; 1350 fmode_t fmode = open_flags & (FMODE_READ | FMODE_WRITE | FMODE_EXEC); 1351 1352 cred = rpc_lookup_cred(); 1353 if (IS_ERR(cred)) 1354 return ERR_CAST(cred); 1355 ctx = alloc_nfs_open_context(dentry, cred, fmode); 1356 put_rpccred(cred); 1357 if (ctx == NULL) 1358 return ERR_PTR(-ENOMEM); 1359 return ctx; 1360 } 1361 1362 static int do_open(struct inode *inode, struct file *filp) 1363 { 1364 nfs_fscache_set_inode_cookie(inode, filp); 1365 return 0; 1366 } 1367 1368 static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx) 1369 { 1370 struct file *filp; 1371 int ret = 0; 1372 1373 /* If the open_intent is for execute, we have an extra check to make */ 1374 if (ctx->mode & FMODE_EXEC) { 1375 ret = nfs_may_open(ctx->dentry->d_inode, 1376 ctx->cred, 1377 nd->intent.open.flags); 1378 if (ret < 0) 1379 goto out; 1380 } 1381 filp = lookup_instantiate_filp(nd, ctx->dentry, do_open); 1382 if (IS_ERR(filp)) 1383 ret = PTR_ERR(filp); 1384 else 1385 nfs_file_set_open_context(filp, ctx); 1386 out: 1387 put_nfs_open_context(ctx); 1388 return ret; 1389 } 1390 1391 static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) 1392 { 1393 struct nfs_open_context *ctx; 1394 struct iattr attr; 1395 struct dentry *res = NULL; 1396 struct inode *inode; 1397 int open_flags; 1398 int err; 1399 1400 dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n", 1401 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1402 1403 /* Check that we are indeed trying to open this file */ 1404 if (!is_atomic_open(nd)) 1405 goto no_open; 1406 1407 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) { 1408 res = ERR_PTR(-ENAMETOOLONG); 1409 goto out; 1410 } 1411 1412 /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash 1413 * the dentry. */ 1414 if (nd->flags & LOOKUP_EXCL) { 1415 d_instantiate(dentry, NULL); 1416 goto out; 1417 } 1418 1419 open_flags = nd->intent.open.flags; 1420 1421 ctx = create_nfs_open_context(dentry, open_flags); 1422 res = ERR_CAST(ctx); 1423 if (IS_ERR(ctx)) 1424 goto out; 1425 1426 if (nd->flags & LOOKUP_CREATE) { 1427 attr.ia_mode = nd->intent.open.create_mode; 1428 attr.ia_valid = ATTR_MODE; 1429 attr.ia_mode &= ~current_umask(); 1430 } else { 1431 open_flags &= ~(O_EXCL | O_CREAT); 1432 attr.ia_valid = 0; 1433 } 1434 1435 /* Open the file on the server */ 1436 nfs_block_sillyrename(dentry->d_parent); 1437 inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr); 1438 if (IS_ERR(inode)) { 1439 nfs_unblock_sillyrename(dentry->d_parent); 1440 put_nfs_open_context(ctx); 1441 switch (PTR_ERR(inode)) { 1442 /* Make a negative dentry */ 1443 case -ENOENT: 1444 d_add(dentry, NULL); 1445 res = NULL; 1446 goto out; 1447 /* This turned out not to be a regular file */ 1448 case -ENOTDIR: 1449 goto no_open; 1450 case -ELOOP: 1451 if (!(nd->intent.open.flags & O_NOFOLLOW)) 1452 goto no_open; 1453 /* case -EISDIR: */ 1454 /* case -EINVAL: */ 1455 default: 1456 res = ERR_CAST(inode); 1457 goto out; 1458 } 1459 } 1460 res = d_add_unique(dentry, inode); 1461 nfs_unblock_sillyrename(dentry->d_parent); 1462 if (res != NULL) { 1463 dput(ctx->dentry); 1464 ctx->dentry = dget(res); 1465 dentry = res; 1466 } 1467 err = nfs_intent_set_file(nd, ctx); 1468 if (err < 0) { 1469 if (res != NULL) 1470 dput(res); 1471 return ERR_PTR(err); 1472 } 1473 out: 1474 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1475 return res; 1476 no_open: 1477 return nfs_lookup(dir, dentry, nd); 1478 } 1479 1480 static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) 1481 { 1482 struct dentry *parent = NULL; 1483 struct inode *inode; 1484 struct inode *dir; 1485 struct nfs_open_context *ctx; 1486 int openflags, ret = 0; 1487 1488 if (nd->flags & LOOKUP_RCU) 1489 return -ECHILD; 1490 1491 inode = dentry->d_inode; 1492 if (!is_atomic_open(nd) || d_mountpoint(dentry)) 1493 goto no_open; 1494 1495 parent = dget_parent(dentry); 1496 dir = parent->d_inode; 1497 1498 /* We can't create new files in nfs_open_revalidate(), so we 1499 * optimize away revalidation of negative dentries. 1500 */ 1501 if (inode == NULL) { 1502 if (!nfs_neg_need_reval(dir, dentry, nd)) 1503 ret = 1; 1504 goto out; 1505 } 1506 1507 /* NFS only supports OPEN on regular files */ 1508 if (!S_ISREG(inode->i_mode)) 1509 goto no_open_dput; 1510 openflags = nd->intent.open.flags; 1511 /* We cannot do exclusive creation on a positive dentry */ 1512 if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) 1513 goto no_open_dput; 1514 /* We can't create new files, or truncate existing ones here */ 1515 openflags &= ~(O_CREAT|O_EXCL|O_TRUNC); 1516 1517 ctx = create_nfs_open_context(dentry, openflags); 1518 ret = PTR_ERR(ctx); 1519 if (IS_ERR(ctx)) 1520 goto out; 1521 /* 1522 * Note: we're not holding inode->i_mutex and so may be racing with 1523 * operations that change the directory. We therefore save the 1524 * change attribute *before* we do the RPC call. 1525 */ 1526 inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, NULL); 1527 if (IS_ERR(inode)) { 1528 ret = PTR_ERR(inode); 1529 switch (ret) { 1530 case -EPERM: 1531 case -EACCES: 1532 case -EDQUOT: 1533 case -ENOSPC: 1534 case -EROFS: 1535 goto out_put_ctx; 1536 default: 1537 goto out_drop; 1538 } 1539 } 1540 iput(inode); 1541 if (inode != dentry->d_inode) 1542 goto out_drop; 1543 1544 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1545 ret = nfs_intent_set_file(nd, ctx); 1546 if (ret >= 0) 1547 ret = 1; 1548 out: 1549 dput(parent); 1550 return ret; 1551 out_drop: 1552 d_drop(dentry); 1553 ret = 0; 1554 out_put_ctx: 1555 put_nfs_open_context(ctx); 1556 goto out; 1557 1558 no_open_dput: 1559 dput(parent); 1560 no_open: 1561 return nfs_lookup_revalidate(dentry, nd); 1562 } 1563 1564 static int nfs_open_create(struct inode *dir, struct dentry *dentry, int mode, 1565 struct nameidata *nd) 1566 { 1567 struct nfs_open_context *ctx = NULL; 1568 struct iattr attr; 1569 int error; 1570 int open_flags = O_CREAT|O_EXCL|FMODE_READ; 1571 1572 dfprintk(VFS, "NFS: create(%s/%ld), %s\n", 1573 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1574 1575 attr.ia_mode = mode; 1576 attr.ia_valid = ATTR_MODE; 1577 1578 if (nd && (nd->flags & LOOKUP_OPEN) != 0) 1579 open_flags = nd->intent.open.flags; 1580 1581 ctx = create_nfs_open_context(dentry, open_flags); 1582 error = PTR_ERR(ctx); 1583 if (IS_ERR(ctx)) 1584 goto out_err_drop; 1585 1586 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx); 1587 if (error != 0) 1588 goto out_put_ctx; 1589 if (nd && (nd->flags & LOOKUP_OPEN) != 0) { 1590 error = nfs_intent_set_file(nd, ctx); 1591 if (error < 0) 1592 goto out_err; 1593 } else { 1594 put_nfs_open_context(ctx); 1595 } 1596 return 0; 1597 out_put_ctx: 1598 put_nfs_open_context(ctx); 1599 out_err_drop: 1600 d_drop(dentry); 1601 out_err: 1602 return error; 1603 } 1604 1605 #endif /* CONFIG_NFSV4 */ 1606 1607 /* 1608 * Code common to create, mkdir, and mknod. 1609 */ 1610 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, 1611 struct nfs_fattr *fattr) 1612 { 1613 struct dentry *parent = dget_parent(dentry); 1614 struct inode *dir = parent->d_inode; 1615 struct inode *inode; 1616 int error = -EACCES; 1617 1618 d_drop(dentry); 1619 1620 /* We may have been initialized further down */ 1621 if (dentry->d_inode) 1622 goto out; 1623 if (fhandle->size == 0) { 1624 error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); 1625 if (error) 1626 goto out_error; 1627 } 1628 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1629 if (!(fattr->valid & NFS_ATTR_FATTR)) { 1630 struct nfs_server *server = NFS_SB(dentry->d_sb); 1631 error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr); 1632 if (error < 0) 1633 goto out_error; 1634 } 1635 inode = nfs_fhget(dentry->d_sb, fhandle, fattr); 1636 error = PTR_ERR(inode); 1637 if (IS_ERR(inode)) 1638 goto out_error; 1639 d_add(dentry, inode); 1640 out: 1641 dput(parent); 1642 return 0; 1643 out_error: 1644 nfs_mark_for_revalidate(dir); 1645 dput(parent); 1646 return error; 1647 } 1648 1649 /* 1650 * Following a failed create operation, we drop the dentry rather 1651 * than retain a negative dentry. This avoids a problem in the event 1652 * that the operation succeeded on the server, but an error in the 1653 * reply path made it appear to have failed. 1654 */ 1655 static int nfs_create(struct inode *dir, struct dentry *dentry, int mode, 1656 struct nameidata *nd) 1657 { 1658 struct iattr attr; 1659 int error; 1660 int open_flags = O_CREAT|O_EXCL|FMODE_READ; 1661 1662 dfprintk(VFS, "NFS: create(%s/%ld), %s\n", 1663 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1664 1665 attr.ia_mode = mode; 1666 attr.ia_valid = ATTR_MODE; 1667 1668 if (nd && (nd->flags & LOOKUP_OPEN) != 0) 1669 open_flags = nd->intent.open.flags; 1670 1671 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, NULL); 1672 if (error != 0) 1673 goto out_err; 1674 return 0; 1675 out_err: 1676 d_drop(dentry); 1677 return error; 1678 } 1679 1680 /* 1681 * See comments for nfs_proc_create regarding failed operations. 1682 */ 1683 static int 1684 nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev) 1685 { 1686 struct iattr attr; 1687 int status; 1688 1689 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n", 1690 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1691 1692 if (!new_valid_dev(rdev)) 1693 return -EINVAL; 1694 1695 attr.ia_mode = mode; 1696 attr.ia_valid = ATTR_MODE; 1697 1698 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); 1699 if (status != 0) 1700 goto out_err; 1701 return 0; 1702 out_err: 1703 d_drop(dentry); 1704 return status; 1705 } 1706 1707 /* 1708 * See comments for nfs_proc_create regarding failed operations. 1709 */ 1710 static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 1711 { 1712 struct iattr attr; 1713 int error; 1714 1715 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n", 1716 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1717 1718 attr.ia_valid = ATTR_MODE; 1719 attr.ia_mode = mode | S_IFDIR; 1720 1721 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); 1722 if (error != 0) 1723 goto out_err; 1724 return 0; 1725 out_err: 1726 d_drop(dentry); 1727 return error; 1728 } 1729 1730 static void nfs_dentry_handle_enoent(struct dentry *dentry) 1731 { 1732 if (dentry->d_inode != NULL && !d_unhashed(dentry)) 1733 d_delete(dentry); 1734 } 1735 1736 static int nfs_rmdir(struct inode *dir, struct dentry *dentry) 1737 { 1738 int error; 1739 1740 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n", 1741 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1742 1743 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); 1744 /* Ensure the VFS deletes this inode */ 1745 if (error == 0 && dentry->d_inode != NULL) 1746 clear_nlink(dentry->d_inode); 1747 else if (error == -ENOENT) 1748 nfs_dentry_handle_enoent(dentry); 1749 1750 return error; 1751 } 1752 1753 /* 1754 * Remove a file after making sure there are no pending writes, 1755 * and after checking that the file has only one user. 1756 * 1757 * We invalidate the attribute cache and free the inode prior to the operation 1758 * to avoid possible races if the server reuses the inode. 1759 */ 1760 static int nfs_safe_remove(struct dentry *dentry) 1761 { 1762 struct inode *dir = dentry->d_parent->d_inode; 1763 struct inode *inode = dentry->d_inode; 1764 int error = -EBUSY; 1765 1766 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n", 1767 dentry->d_parent->d_name.name, dentry->d_name.name); 1768 1769 /* If the dentry was sillyrenamed, we simply call d_delete() */ 1770 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 1771 error = 0; 1772 goto out; 1773 } 1774 1775 if (inode != NULL) { 1776 nfs_inode_return_delegation(inode); 1777 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); 1778 /* The VFS may want to delete this inode */ 1779 if (error == 0) 1780 nfs_drop_nlink(inode); 1781 nfs_mark_for_revalidate(inode); 1782 } else 1783 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); 1784 if (error == -ENOENT) 1785 nfs_dentry_handle_enoent(dentry); 1786 out: 1787 return error; 1788 } 1789 1790 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode 1791 * belongs to an active ".nfs..." file and we return -EBUSY. 1792 * 1793 * If sillyrename() returns 0, we do nothing, otherwise we unlink. 1794 */ 1795 static int nfs_unlink(struct inode *dir, struct dentry *dentry) 1796 { 1797 int error; 1798 int need_rehash = 0; 1799 1800 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, 1801 dir->i_ino, dentry->d_name.name); 1802 1803 spin_lock(&dentry->d_lock); 1804 if (dentry->d_count > 1) { 1805 spin_unlock(&dentry->d_lock); 1806 /* Start asynchronous writeout of the inode */ 1807 write_inode_now(dentry->d_inode, 0); 1808 error = nfs_sillyrename(dir, dentry); 1809 return error; 1810 } 1811 if (!d_unhashed(dentry)) { 1812 __d_drop(dentry); 1813 need_rehash = 1; 1814 } 1815 spin_unlock(&dentry->d_lock); 1816 error = nfs_safe_remove(dentry); 1817 if (!error || error == -ENOENT) { 1818 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1819 } else if (need_rehash) 1820 d_rehash(dentry); 1821 return error; 1822 } 1823 1824 /* 1825 * To create a symbolic link, most file systems instantiate a new inode, 1826 * add a page to it containing the path, then write it out to the disk 1827 * using prepare_write/commit_write. 1828 * 1829 * Unfortunately the NFS client can't create the in-core inode first 1830 * because it needs a file handle to create an in-core inode (see 1831 * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the 1832 * symlink request has completed on the server. 1833 * 1834 * So instead we allocate a raw page, copy the symname into it, then do 1835 * the SYMLINK request with the page as the buffer. If it succeeds, we 1836 * now have a new file handle and can instantiate an in-core NFS inode 1837 * and move the raw page into its mapping. 1838 */ 1839 static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) 1840 { 1841 struct pagevec lru_pvec; 1842 struct page *page; 1843 char *kaddr; 1844 struct iattr attr; 1845 unsigned int pathlen = strlen(symname); 1846 int error; 1847 1848 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id, 1849 dir->i_ino, dentry->d_name.name, symname); 1850 1851 if (pathlen > PAGE_SIZE) 1852 return -ENAMETOOLONG; 1853 1854 attr.ia_mode = S_IFLNK | S_IRWXUGO; 1855 attr.ia_valid = ATTR_MODE; 1856 1857 page = alloc_page(GFP_HIGHUSER); 1858 if (!page) 1859 return -ENOMEM; 1860 1861 kaddr = kmap_atomic(page, KM_USER0); 1862 memcpy(kaddr, symname, pathlen); 1863 if (pathlen < PAGE_SIZE) 1864 memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); 1865 kunmap_atomic(kaddr, KM_USER0); 1866 1867 error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); 1868 if (error != 0) { 1869 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n", 1870 dir->i_sb->s_id, dir->i_ino, 1871 dentry->d_name.name, symname, error); 1872 d_drop(dentry); 1873 __free_page(page); 1874 return error; 1875 } 1876 1877 /* 1878 * No big deal if we can't add this page to the page cache here. 1879 * READLINK will get the missing page from the server if needed. 1880 */ 1881 pagevec_init(&lru_pvec, 0); 1882 if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0, 1883 GFP_KERNEL)) { 1884 pagevec_add(&lru_pvec, page); 1885 pagevec_lru_add_file(&lru_pvec); 1886 SetPageUptodate(page); 1887 unlock_page(page); 1888 } else 1889 __free_page(page); 1890 1891 return 0; 1892 } 1893 1894 static int 1895 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) 1896 { 1897 struct inode *inode = old_dentry->d_inode; 1898 int error; 1899 1900 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n", 1901 old_dentry->d_parent->d_name.name, old_dentry->d_name.name, 1902 dentry->d_parent->d_name.name, dentry->d_name.name); 1903 1904 nfs_inode_return_delegation(inode); 1905 1906 d_drop(dentry); 1907 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); 1908 if (error == 0) { 1909 ihold(inode); 1910 d_add(dentry, inode); 1911 } 1912 return error; 1913 } 1914 1915 /* 1916 * RENAME 1917 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a 1918 * different file handle for the same inode after a rename (e.g. when 1919 * moving to a different directory). A fail-safe method to do so would 1920 * be to look up old_dir/old_name, create a link to new_dir/new_name and 1921 * rename the old file using the sillyrename stuff. This way, the original 1922 * file in old_dir will go away when the last process iput()s the inode. 1923 * 1924 * FIXED. 1925 * 1926 * It actually works quite well. One needs to have the possibility for 1927 * at least one ".nfs..." file in each directory the file ever gets 1928 * moved or linked to which happens automagically with the new 1929 * implementation that only depends on the dcache stuff instead of 1930 * using the inode layer 1931 * 1932 * Unfortunately, things are a little more complicated than indicated 1933 * above. For a cross-directory move, we want to make sure we can get 1934 * rid of the old inode after the operation. This means there must be 1935 * no pending writes (if it's a file), and the use count must be 1. 1936 * If these conditions are met, we can drop the dentries before doing 1937 * the rename. 1938 */ 1939 static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, 1940 struct inode *new_dir, struct dentry *new_dentry) 1941 { 1942 struct inode *old_inode = old_dentry->d_inode; 1943 struct inode *new_inode = new_dentry->d_inode; 1944 struct dentry *dentry = NULL, *rehash = NULL; 1945 int error = -EBUSY; 1946 1947 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", 1948 old_dentry->d_parent->d_name.name, old_dentry->d_name.name, 1949 new_dentry->d_parent->d_name.name, new_dentry->d_name.name, 1950 new_dentry->d_count); 1951 1952 /* 1953 * For non-directories, check whether the target is busy and if so, 1954 * make a copy of the dentry and then do a silly-rename. If the 1955 * silly-rename succeeds, the copied dentry is hashed and becomes 1956 * the new target. 1957 */ 1958 if (new_inode && !S_ISDIR(new_inode->i_mode)) { 1959 /* 1960 * To prevent any new references to the target during the 1961 * rename, we unhash the dentry in advance. 1962 */ 1963 if (!d_unhashed(new_dentry)) { 1964 d_drop(new_dentry); 1965 rehash = new_dentry; 1966 } 1967 1968 if (new_dentry->d_count > 2) { 1969 int err; 1970 1971 /* copy the target dentry's name */ 1972 dentry = d_alloc(new_dentry->d_parent, 1973 &new_dentry->d_name); 1974 if (!dentry) 1975 goto out; 1976 1977 /* silly-rename the existing target ... */ 1978 err = nfs_sillyrename(new_dir, new_dentry); 1979 if (err) 1980 goto out; 1981 1982 new_dentry = dentry; 1983 rehash = NULL; 1984 new_inode = NULL; 1985 } 1986 } 1987 1988 nfs_inode_return_delegation(old_inode); 1989 if (new_inode != NULL) 1990 nfs_inode_return_delegation(new_inode); 1991 1992 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name, 1993 new_dir, &new_dentry->d_name); 1994 nfs_mark_for_revalidate(old_inode); 1995 out: 1996 if (rehash) 1997 d_rehash(rehash); 1998 if (!error) { 1999 if (new_inode != NULL) 2000 nfs_drop_nlink(new_inode); 2001 d_move(old_dentry, new_dentry); 2002 nfs_set_verifier(new_dentry, 2003 nfs_save_change_attribute(new_dir)); 2004 } else if (error == -ENOENT) 2005 nfs_dentry_handle_enoent(old_dentry); 2006 2007 /* new dentry created? */ 2008 if (dentry) 2009 dput(dentry); 2010 return error; 2011 } 2012 2013 static DEFINE_SPINLOCK(nfs_access_lru_lock); 2014 static LIST_HEAD(nfs_access_lru_list); 2015 static atomic_long_t nfs_access_nr_entries; 2016 2017 static void nfs_access_free_entry(struct nfs_access_entry *entry) 2018 { 2019 put_rpccred(entry->cred); 2020 kfree(entry); 2021 smp_mb__before_atomic_dec(); 2022 atomic_long_dec(&nfs_access_nr_entries); 2023 smp_mb__after_atomic_dec(); 2024 } 2025 2026 static void nfs_access_free_list(struct list_head *head) 2027 { 2028 struct nfs_access_entry *cache; 2029 2030 while (!list_empty(head)) { 2031 cache = list_entry(head->next, struct nfs_access_entry, lru); 2032 list_del(&cache->lru); 2033 nfs_access_free_entry(cache); 2034 } 2035 } 2036 2037 int nfs_access_cache_shrinker(struct shrinker *shrink, 2038 struct shrink_control *sc) 2039 { 2040 LIST_HEAD(head); 2041 struct nfs_inode *nfsi, *next; 2042 struct nfs_access_entry *cache; 2043 int nr_to_scan = sc->nr_to_scan; 2044 gfp_t gfp_mask = sc->gfp_mask; 2045 2046 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL) 2047 return (nr_to_scan == 0) ? 0 : -1; 2048 2049 spin_lock(&nfs_access_lru_lock); 2050 list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) { 2051 struct inode *inode; 2052 2053 if (nr_to_scan-- == 0) 2054 break; 2055 inode = &nfsi->vfs_inode; 2056 spin_lock(&inode->i_lock); 2057 if (list_empty(&nfsi->access_cache_entry_lru)) 2058 goto remove_lru_entry; 2059 cache = list_entry(nfsi->access_cache_entry_lru.next, 2060 struct nfs_access_entry, lru); 2061 list_move(&cache->lru, &head); 2062 rb_erase(&cache->rb_node, &nfsi->access_cache); 2063 if (!list_empty(&nfsi->access_cache_entry_lru)) 2064 list_move_tail(&nfsi->access_cache_inode_lru, 2065 &nfs_access_lru_list); 2066 else { 2067 remove_lru_entry: 2068 list_del_init(&nfsi->access_cache_inode_lru); 2069 smp_mb__before_clear_bit(); 2070 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); 2071 smp_mb__after_clear_bit(); 2072 } 2073 spin_unlock(&inode->i_lock); 2074 } 2075 spin_unlock(&nfs_access_lru_lock); 2076 nfs_access_free_list(&head); 2077 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; 2078 } 2079 2080 static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head) 2081 { 2082 struct rb_root *root_node = &nfsi->access_cache; 2083 struct rb_node *n; 2084 struct nfs_access_entry *entry; 2085 2086 /* Unhook entries from the cache */ 2087 while ((n = rb_first(root_node)) != NULL) { 2088 entry = rb_entry(n, struct nfs_access_entry, rb_node); 2089 rb_erase(n, root_node); 2090 list_move(&entry->lru, head); 2091 } 2092 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; 2093 } 2094 2095 void nfs_access_zap_cache(struct inode *inode) 2096 { 2097 LIST_HEAD(head); 2098 2099 if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0) 2100 return; 2101 /* Remove from global LRU init */ 2102 spin_lock(&nfs_access_lru_lock); 2103 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) 2104 list_del_init(&NFS_I(inode)->access_cache_inode_lru); 2105 2106 spin_lock(&inode->i_lock); 2107 __nfs_access_zap_cache(NFS_I(inode), &head); 2108 spin_unlock(&inode->i_lock); 2109 spin_unlock(&nfs_access_lru_lock); 2110 nfs_access_free_list(&head); 2111 } 2112 2113 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred) 2114 { 2115 struct rb_node *n = NFS_I(inode)->access_cache.rb_node; 2116 struct nfs_access_entry *entry; 2117 2118 while (n != NULL) { 2119 entry = rb_entry(n, struct nfs_access_entry, rb_node); 2120 2121 if (cred < entry->cred) 2122 n = n->rb_left; 2123 else if (cred > entry->cred) 2124 n = n->rb_right; 2125 else 2126 return entry; 2127 } 2128 return NULL; 2129 } 2130 2131 static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) 2132 { 2133 struct nfs_inode *nfsi = NFS_I(inode); 2134 struct nfs_access_entry *cache; 2135 int err = -ENOENT; 2136 2137 spin_lock(&inode->i_lock); 2138 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) 2139 goto out_zap; 2140 cache = nfs_access_search_rbtree(inode, cred); 2141 if (cache == NULL) 2142 goto out; 2143 if (!nfs_have_delegated_attributes(inode) && 2144 !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo)) 2145 goto out_stale; 2146 res->jiffies = cache->jiffies; 2147 res->cred = cache->cred; 2148 res->mask = cache->mask; 2149 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); 2150 err = 0; 2151 out: 2152 spin_unlock(&inode->i_lock); 2153 return err; 2154 out_stale: 2155 rb_erase(&cache->rb_node, &nfsi->access_cache); 2156 list_del(&cache->lru); 2157 spin_unlock(&inode->i_lock); 2158 nfs_access_free_entry(cache); 2159 return -ENOENT; 2160 out_zap: 2161 spin_unlock(&inode->i_lock); 2162 nfs_access_zap_cache(inode); 2163 return -ENOENT; 2164 } 2165 2166 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) 2167 { 2168 struct nfs_inode *nfsi = NFS_I(inode); 2169 struct rb_root *root_node = &nfsi->access_cache; 2170 struct rb_node **p = &root_node->rb_node; 2171 struct rb_node *parent = NULL; 2172 struct nfs_access_entry *entry; 2173 2174 spin_lock(&inode->i_lock); 2175 while (*p != NULL) { 2176 parent = *p; 2177 entry = rb_entry(parent, struct nfs_access_entry, rb_node); 2178 2179 if (set->cred < entry->cred) 2180 p = &parent->rb_left; 2181 else if (set->cred > entry->cred) 2182 p = &parent->rb_right; 2183 else 2184 goto found; 2185 } 2186 rb_link_node(&set->rb_node, parent, p); 2187 rb_insert_color(&set->rb_node, root_node); 2188 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); 2189 spin_unlock(&inode->i_lock); 2190 return; 2191 found: 2192 rb_replace_node(parent, &set->rb_node, root_node); 2193 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); 2194 list_del(&entry->lru); 2195 spin_unlock(&inode->i_lock); 2196 nfs_access_free_entry(entry); 2197 } 2198 2199 static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) 2200 { 2201 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); 2202 if (cache == NULL) 2203 return; 2204 RB_CLEAR_NODE(&cache->rb_node); 2205 cache->jiffies = set->jiffies; 2206 cache->cred = get_rpccred(set->cred); 2207 cache->mask = set->mask; 2208 2209 nfs_access_add_rbtree(inode, cache); 2210 2211 /* Update accounting */ 2212 smp_mb__before_atomic_inc(); 2213 atomic_long_inc(&nfs_access_nr_entries); 2214 smp_mb__after_atomic_inc(); 2215 2216 /* Add inode to global LRU list */ 2217 if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { 2218 spin_lock(&nfs_access_lru_lock); 2219 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) 2220 list_add_tail(&NFS_I(inode)->access_cache_inode_lru, 2221 &nfs_access_lru_list); 2222 spin_unlock(&nfs_access_lru_lock); 2223 } 2224 } 2225 2226 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) 2227 { 2228 struct nfs_access_entry cache; 2229 int status; 2230 2231 status = nfs_access_get_cached(inode, cred, &cache); 2232 if (status == 0) 2233 goto out; 2234 2235 /* Be clever: ask server to check for all possible rights */ 2236 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; 2237 cache.cred = cred; 2238 cache.jiffies = jiffies; 2239 status = NFS_PROTO(inode)->access(inode, &cache); 2240 if (status != 0) { 2241 if (status == -ESTALE) { 2242 nfs_zap_caches(inode); 2243 if (!S_ISDIR(inode->i_mode)) 2244 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); 2245 } 2246 return status; 2247 } 2248 nfs_access_add_cache(inode, &cache); 2249 out: 2250 if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) 2251 return 0; 2252 return -EACCES; 2253 } 2254 2255 static int nfs_open_permission_mask(int openflags) 2256 { 2257 int mask = 0; 2258 2259 if (openflags & FMODE_READ) 2260 mask |= MAY_READ; 2261 if (openflags & FMODE_WRITE) 2262 mask |= MAY_WRITE; 2263 if (openflags & FMODE_EXEC) 2264 mask |= MAY_EXEC; 2265 return mask; 2266 } 2267 2268 int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) 2269 { 2270 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); 2271 } 2272 2273 int nfs_permission(struct inode *inode, int mask) 2274 { 2275 struct rpc_cred *cred; 2276 int res = 0; 2277 2278 if (mask & MAY_NOT_BLOCK) 2279 return -ECHILD; 2280 2281 nfs_inc_stats(inode, NFSIOS_VFSACCESS); 2282 2283 if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) 2284 goto out; 2285 /* Is this sys_access() ? */ 2286 if (mask & (MAY_ACCESS | MAY_CHDIR)) 2287 goto force_lookup; 2288 2289 switch (inode->i_mode & S_IFMT) { 2290 case S_IFLNK: 2291 goto out; 2292 case S_IFREG: 2293 /* NFSv4 has atomic_open... */ 2294 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) 2295 && (mask & MAY_OPEN) 2296 && !(mask & MAY_EXEC)) 2297 goto out; 2298 break; 2299 case S_IFDIR: 2300 /* 2301 * Optimize away all write operations, since the server 2302 * will check permissions when we perform the op. 2303 */ 2304 if ((mask & MAY_WRITE) && !(mask & MAY_READ)) 2305 goto out; 2306 } 2307 2308 force_lookup: 2309 if (!NFS_PROTO(inode)->access) 2310 goto out_notsup; 2311 2312 cred = rpc_lookup_cred(); 2313 if (!IS_ERR(cred)) { 2314 res = nfs_do_access(inode, cred, mask); 2315 put_rpccred(cred); 2316 } else 2317 res = PTR_ERR(cred); 2318 out: 2319 if (!res && (mask & MAY_EXEC) && !execute_ok(inode)) 2320 res = -EACCES; 2321 2322 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n", 2323 inode->i_sb->s_id, inode->i_ino, mask, res); 2324 return res; 2325 out_notsup: 2326 res = nfs_revalidate_inode(NFS_SERVER(inode), inode); 2327 if (res == 0) 2328 res = generic_permission(inode, mask); 2329 goto out; 2330 } 2331 2332 /* 2333 * Local variables: 2334 * version-control: t 2335 * kept-new-versions: 5 2336 * End: 2337 */ 2338