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 and none of them is set before that last 1001 * component. 1002 */ 1003 static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, 1004 unsigned int mask) 1005 { 1006 return nd->flags & mask; 1007 } 1008 1009 /* 1010 * Use intent information to check whether or not we're going to do 1011 * an O_EXCL create using this path component. 1012 */ 1013 static int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd) 1014 { 1015 if (NFS_PROTO(dir)->version == 2) 1016 return 0; 1017 return nd && nfs_lookup_check_intent(nd, LOOKUP_EXCL); 1018 } 1019 1020 /* 1021 * Inode and filehandle revalidation for lookups. 1022 * 1023 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL, 1024 * or if the intent information indicates that we're about to open this 1025 * particular file and the "nocto" mount flag is not set. 1026 * 1027 */ 1028 static inline 1029 int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd) 1030 { 1031 struct nfs_server *server = NFS_SERVER(inode); 1032 1033 if (IS_AUTOMOUNT(inode)) 1034 return 0; 1035 if (nd != NULL) { 1036 /* VFS wants an on-the-wire revalidation */ 1037 if (nd->flags & LOOKUP_REVAL) 1038 goto out_force; 1039 /* This is an open(2) */ 1040 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 && 1041 !(server->flags & NFS_MOUNT_NOCTO) && 1042 (S_ISREG(inode->i_mode) || 1043 S_ISDIR(inode->i_mode))) 1044 goto out_force; 1045 return 0; 1046 } 1047 return nfs_revalidate_inode(server, inode); 1048 out_force: 1049 return __nfs_revalidate_inode(server, inode); 1050 } 1051 1052 /* 1053 * We judge how long we want to trust negative 1054 * dentries by looking at the parent inode mtime. 1055 * 1056 * If parent mtime has changed, we revalidate, else we wait for a 1057 * period corresponding to the parent's attribute cache timeout value. 1058 */ 1059 static inline 1060 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, 1061 struct nameidata *nd) 1062 { 1063 /* Don't revalidate a negative dentry if we're creating a new file */ 1064 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) 1065 return 0; 1066 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) 1067 return 1; 1068 return !nfs_check_verifier(dir, dentry); 1069 } 1070 1071 /* 1072 * This is called every time the dcache has a lookup hit, 1073 * and we should check whether we can really trust that 1074 * lookup. 1075 * 1076 * NOTE! The hit can be a negative hit too, don't assume 1077 * we have an inode! 1078 * 1079 * If the parent directory is seen to have changed, we throw out the 1080 * cached dentry and do a new lookup. 1081 */ 1082 static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd) 1083 { 1084 struct inode *dir; 1085 struct inode *inode; 1086 struct dentry *parent; 1087 struct nfs_fh *fhandle = NULL; 1088 struct nfs_fattr *fattr = NULL; 1089 int error; 1090 1091 if (nd->flags & LOOKUP_RCU) 1092 return -ECHILD; 1093 1094 parent = dget_parent(dentry); 1095 dir = parent->d_inode; 1096 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); 1097 inode = dentry->d_inode; 1098 1099 if (!inode) { 1100 if (nfs_neg_need_reval(dir, dentry, nd)) 1101 goto out_bad; 1102 goto out_valid; 1103 } 1104 1105 if (is_bad_inode(inode)) { 1106 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n", 1107 __func__, dentry->d_parent->d_name.name, 1108 dentry->d_name.name); 1109 goto out_bad; 1110 } 1111 1112 if (nfs_have_delegation(inode, FMODE_READ)) 1113 goto out_set_verifier; 1114 1115 /* Force a full look up iff the parent directory has changed */ 1116 if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) { 1117 if (nfs_lookup_verify_inode(inode, nd)) 1118 goto out_zap_parent; 1119 goto out_valid; 1120 } 1121 1122 if (NFS_STALE(inode)) 1123 goto out_bad; 1124 1125 error = -ENOMEM; 1126 fhandle = nfs_alloc_fhandle(); 1127 fattr = nfs_alloc_fattr(); 1128 if (fhandle == NULL || fattr == NULL) 1129 goto out_error; 1130 1131 error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); 1132 if (error) 1133 goto out_bad; 1134 if (nfs_compare_fh(NFS_FH(inode), fhandle)) 1135 goto out_bad; 1136 if ((error = nfs_refresh_inode(inode, fattr)) != 0) 1137 goto out_bad; 1138 1139 nfs_free_fattr(fattr); 1140 nfs_free_fhandle(fhandle); 1141 out_set_verifier: 1142 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1143 out_valid: 1144 dput(parent); 1145 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n", 1146 __func__, dentry->d_parent->d_name.name, 1147 dentry->d_name.name); 1148 return 1; 1149 out_zap_parent: 1150 nfs_zap_caches(dir); 1151 out_bad: 1152 nfs_mark_for_revalidate(dir); 1153 if (inode && S_ISDIR(inode->i_mode)) { 1154 /* Purge readdir caches. */ 1155 nfs_zap_caches(inode); 1156 /* If we have submounts, don't unhash ! */ 1157 if (have_submounts(dentry)) 1158 goto out_valid; 1159 if (dentry->d_flags & DCACHE_DISCONNECTED) 1160 goto out_valid; 1161 shrink_dcache_parent(dentry); 1162 } 1163 d_drop(dentry); 1164 nfs_free_fattr(fattr); 1165 nfs_free_fhandle(fhandle); 1166 dput(parent); 1167 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", 1168 __func__, dentry->d_parent->d_name.name, 1169 dentry->d_name.name); 1170 return 0; 1171 out_error: 1172 nfs_free_fattr(fattr); 1173 nfs_free_fhandle(fhandle); 1174 dput(parent); 1175 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n", 1176 __func__, dentry->d_parent->d_name.name, 1177 dentry->d_name.name, error); 1178 return error; 1179 } 1180 1181 /* 1182 * This is called from dput() when d_count is going to 0. 1183 */ 1184 static int nfs_dentry_delete(const struct dentry *dentry) 1185 { 1186 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", 1187 dentry->d_parent->d_name.name, dentry->d_name.name, 1188 dentry->d_flags); 1189 1190 /* Unhash any dentry with a stale inode */ 1191 if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode)) 1192 return 1; 1193 1194 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 1195 /* Unhash it, so that ->d_iput() would be called */ 1196 return 1; 1197 } 1198 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) { 1199 /* Unhash it, so that ancestors of killed async unlink 1200 * files will be cleaned up during umount */ 1201 return 1; 1202 } 1203 return 0; 1204 1205 } 1206 1207 static void nfs_drop_nlink(struct inode *inode) 1208 { 1209 spin_lock(&inode->i_lock); 1210 if (inode->i_nlink > 0) 1211 drop_nlink(inode); 1212 spin_unlock(&inode->i_lock); 1213 } 1214 1215 /* 1216 * Called when the dentry loses inode. 1217 * We use it to clean up silly-renamed files. 1218 */ 1219 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) 1220 { 1221 if (S_ISDIR(inode->i_mode)) 1222 /* drop any readdir cache as it could easily be old */ 1223 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA; 1224 1225 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { 1226 drop_nlink(inode); 1227 nfs_complete_unlink(dentry, inode); 1228 } 1229 iput(inode); 1230 } 1231 1232 static void nfs_d_release(struct dentry *dentry) 1233 { 1234 /* free cached devname value, if it survived that far */ 1235 if (unlikely(dentry->d_fsdata)) { 1236 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) 1237 WARN_ON(1); 1238 else 1239 kfree(dentry->d_fsdata); 1240 } 1241 } 1242 1243 const struct dentry_operations nfs_dentry_operations = { 1244 .d_revalidate = nfs_lookup_revalidate, 1245 .d_delete = nfs_dentry_delete, 1246 .d_iput = nfs_dentry_iput, 1247 .d_automount = nfs_d_automount, 1248 .d_release = nfs_d_release, 1249 }; 1250 1251 static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) 1252 { 1253 struct dentry *res; 1254 struct dentry *parent; 1255 struct inode *inode = NULL; 1256 struct nfs_fh *fhandle = NULL; 1257 struct nfs_fattr *fattr = NULL; 1258 int error; 1259 1260 dfprintk(VFS, "NFS: lookup(%s/%s)\n", 1261 dentry->d_parent->d_name.name, dentry->d_name.name); 1262 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); 1263 1264 res = ERR_PTR(-ENAMETOOLONG); 1265 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) 1266 goto out; 1267 1268 /* 1269 * If we're doing an exclusive create, optimize away the lookup 1270 * but don't hash the dentry. 1271 */ 1272 if (nfs_is_exclusive_create(dir, nd)) { 1273 d_instantiate(dentry, NULL); 1274 res = NULL; 1275 goto out; 1276 } 1277 1278 res = ERR_PTR(-ENOMEM); 1279 fhandle = nfs_alloc_fhandle(); 1280 fattr = nfs_alloc_fattr(); 1281 if (fhandle == NULL || fattr == NULL) 1282 goto out; 1283 1284 parent = dentry->d_parent; 1285 /* Protect against concurrent sillydeletes */ 1286 nfs_block_sillyrename(parent); 1287 error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); 1288 if (error == -ENOENT) 1289 goto no_entry; 1290 if (error < 0) { 1291 res = ERR_PTR(error); 1292 goto out_unblock_sillyrename; 1293 } 1294 inode = nfs_fhget(dentry->d_sb, fhandle, fattr); 1295 res = ERR_CAST(inode); 1296 if (IS_ERR(res)) 1297 goto out_unblock_sillyrename; 1298 1299 no_entry: 1300 res = d_materialise_unique(dentry, inode); 1301 if (res != NULL) { 1302 if (IS_ERR(res)) 1303 goto out_unblock_sillyrename; 1304 dentry = res; 1305 } 1306 nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); 1307 out_unblock_sillyrename: 1308 nfs_unblock_sillyrename(parent); 1309 out: 1310 nfs_free_fattr(fattr); 1311 nfs_free_fhandle(fhandle); 1312 return res; 1313 } 1314 1315 #ifdef CONFIG_NFS_V4 1316 static int nfs_open_revalidate(struct dentry *, struct nameidata *); 1317 1318 const struct dentry_operations nfs4_dentry_operations = { 1319 .d_revalidate = nfs_open_revalidate, 1320 .d_delete = nfs_dentry_delete, 1321 .d_iput = nfs_dentry_iput, 1322 .d_automount = nfs_d_automount, 1323 .d_release = nfs_d_release, 1324 }; 1325 1326 /* 1327 * Use intent information to determine whether we need to substitute 1328 * the NFSv4-style stateful OPEN for the LOOKUP call 1329 */ 1330 static int is_atomic_open(struct nameidata *nd) 1331 { 1332 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0) 1333 return 0; 1334 /* NFS does not (yet) have a stateful open for directories */ 1335 if (nd->flags & LOOKUP_DIRECTORY) 1336 return 0; 1337 /* Are we trying to write to a read only partition? */ 1338 if (__mnt_is_readonly(nd->path.mnt) && 1339 (nd->intent.open.flags & (O_CREAT|O_TRUNC|O_ACCMODE))) 1340 return 0; 1341 return 1; 1342 } 1343 1344 static fmode_t flags_to_mode(int flags) 1345 { 1346 fmode_t res = (__force fmode_t)flags & FMODE_EXEC; 1347 if ((flags & O_ACCMODE) != O_WRONLY) 1348 res |= FMODE_READ; 1349 if ((flags & O_ACCMODE) != O_RDONLY) 1350 res |= FMODE_WRITE; 1351 return res; 1352 } 1353 1354 static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags) 1355 { 1356 struct nfs_open_context *ctx; 1357 struct rpc_cred *cred; 1358 fmode_t fmode = flags_to_mode(open_flags); 1359 1360 cred = rpc_lookup_cred(); 1361 if (IS_ERR(cred)) 1362 return ERR_CAST(cred); 1363 ctx = alloc_nfs_open_context(dentry, cred, fmode); 1364 put_rpccred(cred); 1365 if (ctx == NULL) 1366 return ERR_PTR(-ENOMEM); 1367 return ctx; 1368 } 1369 1370 static int do_open(struct inode *inode, struct file *filp) 1371 { 1372 nfs_fscache_set_inode_cookie(inode, filp); 1373 return 0; 1374 } 1375 1376 static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx) 1377 { 1378 struct file *filp; 1379 int ret = 0; 1380 1381 /* If the open_intent is for execute, we have an extra check to make */ 1382 if (ctx->mode & FMODE_EXEC) { 1383 ret = nfs_may_open(ctx->dentry->d_inode, 1384 ctx->cred, 1385 nd->intent.open.flags); 1386 if (ret < 0) 1387 goto out; 1388 } 1389 filp = lookup_instantiate_filp(nd, ctx->dentry, do_open); 1390 if (IS_ERR(filp)) 1391 ret = PTR_ERR(filp); 1392 else 1393 nfs_file_set_open_context(filp, ctx); 1394 out: 1395 put_nfs_open_context(ctx); 1396 return ret; 1397 } 1398 1399 static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) 1400 { 1401 struct nfs_open_context *ctx; 1402 struct iattr attr; 1403 struct dentry *res = NULL; 1404 struct inode *inode; 1405 int open_flags; 1406 int err; 1407 1408 dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n", 1409 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); 1410 1411 /* Check that we are indeed trying to open this file */ 1412 if (!is_atomic_open(nd)) 1413 goto no_open; 1414 1415 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) { 1416 res = ERR_PTR(-ENAMETOOLONG); 1417 goto out; 1418 } 1419 1420 /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash 1421 * the dentry. */ 1422 if (nd->flags & LOOKUP_EXCL) { 1423 d_instantiate(dentry, NULL); 1424 goto out; 1425 } 1426 1427 open_flags = nd->intent.open.flags; 1428 1429 ctx = create_nfs_open_context(dentry, open_flags); 1430 res = ERR_CAST(ctx); 1431 if (IS_ERR(ctx)) 1432 goto out; 1433 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->dentry); 1472 ctx->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 = create_nfs_open_context(dentry, openflags); 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 = O_CREAT|O_EXCL; 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) 1587 open_flags = nd->intent.open.flags; 1588 1589 ctx = create_nfs_open_context(dentry, open_flags); 1590 error = PTR_ERR(ctx); 1591 if (IS_ERR(ctx)) 1592 goto out_err_drop; 1593 1594 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx); 1595 if (error != 0) 1596 goto out_put_ctx; 1597 if (nd) { 1598 error = nfs_intent_set_file(nd, ctx); 1599 if (error < 0) 1600 goto out_err; 1601 } else { 1602 put_nfs_open_context(ctx); 1603 } 1604 return 0; 1605 out_put_ctx: 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 = O_CREAT|O_EXCL; 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) 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, 2046 struct shrink_control *sc) 2047 { 2048 LIST_HEAD(head); 2049 struct nfs_inode *nfsi, *next; 2050 struct nfs_access_entry *cache; 2051 int nr_to_scan = sc->nr_to_scan; 2052 gfp_t gfp_mask = sc->gfp_mask; 2053 2054 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL) 2055 return (nr_to_scan == 0) ? 0 : -1; 2056 2057 spin_lock(&nfs_access_lru_lock); 2058 list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) { 2059 struct inode *inode; 2060 2061 if (nr_to_scan-- == 0) 2062 break; 2063 inode = &nfsi->vfs_inode; 2064 spin_lock(&inode->i_lock); 2065 if (list_empty(&nfsi->access_cache_entry_lru)) 2066 goto remove_lru_entry; 2067 cache = list_entry(nfsi->access_cache_entry_lru.next, 2068 struct nfs_access_entry, lru); 2069 list_move(&cache->lru, &head); 2070 rb_erase(&cache->rb_node, &nfsi->access_cache); 2071 if (!list_empty(&nfsi->access_cache_entry_lru)) 2072 list_move_tail(&nfsi->access_cache_inode_lru, 2073 &nfs_access_lru_list); 2074 else { 2075 remove_lru_entry: 2076 list_del_init(&nfsi->access_cache_inode_lru); 2077 smp_mb__before_clear_bit(); 2078 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); 2079 smp_mb__after_clear_bit(); 2080 } 2081 spin_unlock(&inode->i_lock); 2082 } 2083 spin_unlock(&nfs_access_lru_lock); 2084 nfs_access_free_list(&head); 2085 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; 2086 } 2087 2088 static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head) 2089 { 2090 struct rb_root *root_node = &nfsi->access_cache; 2091 struct rb_node *n; 2092 struct nfs_access_entry *entry; 2093 2094 /* Unhook entries from the cache */ 2095 while ((n = rb_first(root_node)) != NULL) { 2096 entry = rb_entry(n, struct nfs_access_entry, rb_node); 2097 rb_erase(n, root_node); 2098 list_move(&entry->lru, head); 2099 } 2100 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; 2101 } 2102 2103 void nfs_access_zap_cache(struct inode *inode) 2104 { 2105 LIST_HEAD(head); 2106 2107 if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0) 2108 return; 2109 /* Remove from global LRU init */ 2110 spin_lock(&nfs_access_lru_lock); 2111 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) 2112 list_del_init(&NFS_I(inode)->access_cache_inode_lru); 2113 2114 spin_lock(&inode->i_lock); 2115 __nfs_access_zap_cache(NFS_I(inode), &head); 2116 spin_unlock(&inode->i_lock); 2117 spin_unlock(&nfs_access_lru_lock); 2118 nfs_access_free_list(&head); 2119 } 2120 2121 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred) 2122 { 2123 struct rb_node *n = NFS_I(inode)->access_cache.rb_node; 2124 struct nfs_access_entry *entry; 2125 2126 while (n != NULL) { 2127 entry = rb_entry(n, struct nfs_access_entry, rb_node); 2128 2129 if (cred < entry->cred) 2130 n = n->rb_left; 2131 else if (cred > entry->cred) 2132 n = n->rb_right; 2133 else 2134 return entry; 2135 } 2136 return NULL; 2137 } 2138 2139 static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) 2140 { 2141 struct nfs_inode *nfsi = NFS_I(inode); 2142 struct nfs_access_entry *cache; 2143 int err = -ENOENT; 2144 2145 spin_lock(&inode->i_lock); 2146 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) 2147 goto out_zap; 2148 cache = nfs_access_search_rbtree(inode, cred); 2149 if (cache == NULL) 2150 goto out; 2151 if (!nfs_have_delegated_attributes(inode) && 2152 !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo)) 2153 goto out_stale; 2154 res->jiffies = cache->jiffies; 2155 res->cred = cache->cred; 2156 res->mask = cache->mask; 2157 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); 2158 err = 0; 2159 out: 2160 spin_unlock(&inode->i_lock); 2161 return err; 2162 out_stale: 2163 rb_erase(&cache->rb_node, &nfsi->access_cache); 2164 list_del(&cache->lru); 2165 spin_unlock(&inode->i_lock); 2166 nfs_access_free_entry(cache); 2167 return -ENOENT; 2168 out_zap: 2169 spin_unlock(&inode->i_lock); 2170 nfs_access_zap_cache(inode); 2171 return -ENOENT; 2172 } 2173 2174 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) 2175 { 2176 struct nfs_inode *nfsi = NFS_I(inode); 2177 struct rb_root *root_node = &nfsi->access_cache; 2178 struct rb_node **p = &root_node->rb_node; 2179 struct rb_node *parent = NULL; 2180 struct nfs_access_entry *entry; 2181 2182 spin_lock(&inode->i_lock); 2183 while (*p != NULL) { 2184 parent = *p; 2185 entry = rb_entry(parent, struct nfs_access_entry, rb_node); 2186 2187 if (set->cred < entry->cred) 2188 p = &parent->rb_left; 2189 else if (set->cred > entry->cred) 2190 p = &parent->rb_right; 2191 else 2192 goto found; 2193 } 2194 rb_link_node(&set->rb_node, parent, p); 2195 rb_insert_color(&set->rb_node, root_node); 2196 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); 2197 spin_unlock(&inode->i_lock); 2198 return; 2199 found: 2200 rb_replace_node(parent, &set->rb_node, root_node); 2201 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); 2202 list_del(&entry->lru); 2203 spin_unlock(&inode->i_lock); 2204 nfs_access_free_entry(entry); 2205 } 2206 2207 static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) 2208 { 2209 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); 2210 if (cache == NULL) 2211 return; 2212 RB_CLEAR_NODE(&cache->rb_node); 2213 cache->jiffies = set->jiffies; 2214 cache->cred = get_rpccred(set->cred); 2215 cache->mask = set->mask; 2216 2217 nfs_access_add_rbtree(inode, cache); 2218 2219 /* Update accounting */ 2220 smp_mb__before_atomic_inc(); 2221 atomic_long_inc(&nfs_access_nr_entries); 2222 smp_mb__after_atomic_inc(); 2223 2224 /* Add inode to global LRU list */ 2225 if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { 2226 spin_lock(&nfs_access_lru_lock); 2227 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) 2228 list_add_tail(&NFS_I(inode)->access_cache_inode_lru, 2229 &nfs_access_lru_list); 2230 spin_unlock(&nfs_access_lru_lock); 2231 } 2232 } 2233 2234 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) 2235 { 2236 struct nfs_access_entry cache; 2237 int status; 2238 2239 status = nfs_access_get_cached(inode, cred, &cache); 2240 if (status == 0) 2241 goto out; 2242 2243 /* Be clever: ask server to check for all possible rights */ 2244 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; 2245 cache.cred = cred; 2246 cache.jiffies = jiffies; 2247 status = NFS_PROTO(inode)->access(inode, &cache); 2248 if (status != 0) { 2249 if (status == -ESTALE) { 2250 nfs_zap_caches(inode); 2251 if (!S_ISDIR(inode->i_mode)) 2252 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); 2253 } 2254 return status; 2255 } 2256 nfs_access_add_cache(inode, &cache); 2257 out: 2258 if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) 2259 return 0; 2260 return -EACCES; 2261 } 2262 2263 static int nfs_open_permission_mask(int openflags) 2264 { 2265 int mask = 0; 2266 2267 if ((openflags & O_ACCMODE) != O_WRONLY) 2268 mask |= MAY_READ; 2269 if ((openflags & O_ACCMODE) != O_RDONLY) 2270 mask |= MAY_WRITE; 2271 if (openflags & __FMODE_EXEC) 2272 mask |= MAY_EXEC; 2273 return mask; 2274 } 2275 2276 int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) 2277 { 2278 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); 2279 } 2280 2281 int nfs_permission(struct inode *inode, int mask) 2282 { 2283 struct rpc_cred *cred; 2284 int res = 0; 2285 2286 if (mask & MAY_NOT_BLOCK) 2287 return -ECHILD; 2288 2289 nfs_inc_stats(inode, NFSIOS_VFSACCESS); 2290 2291 if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) 2292 goto out; 2293 /* Is this sys_access() ? */ 2294 if (mask & (MAY_ACCESS | MAY_CHDIR)) 2295 goto force_lookup; 2296 2297 switch (inode->i_mode & S_IFMT) { 2298 case S_IFLNK: 2299 goto out; 2300 case S_IFREG: 2301 /* NFSv4 has atomic_open... */ 2302 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) 2303 && (mask & MAY_OPEN) 2304 && !(mask & MAY_EXEC)) 2305 goto out; 2306 break; 2307 case S_IFDIR: 2308 /* 2309 * Optimize away all write operations, since the server 2310 * will check permissions when we perform the op. 2311 */ 2312 if ((mask & MAY_WRITE) && !(mask & MAY_READ)) 2313 goto out; 2314 } 2315 2316 force_lookup: 2317 if (!NFS_PROTO(inode)->access) 2318 goto out_notsup; 2319 2320 cred = rpc_lookup_cred(); 2321 if (!IS_ERR(cred)) { 2322 res = nfs_do_access(inode, cred, mask); 2323 put_rpccred(cred); 2324 } else 2325 res = PTR_ERR(cred); 2326 out: 2327 if (!res && (mask & MAY_EXEC) && !execute_ok(inode)) 2328 res = -EACCES; 2329 2330 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n", 2331 inode->i_sb->s_id, inode->i_ino, mask, res); 2332 return res; 2333 out_notsup: 2334 res = nfs_revalidate_inode(NFS_SERVER(inode), inode); 2335 if (res == 0) 2336 res = generic_permission(inode, mask); 2337 goto out; 2338 } 2339 2340 /* 2341 * Local variables: 2342 * version-control: t 2343 * kept-new-versions: 5 2344 * End: 2345 */ 2346