Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc
[cris-mirror.git] / fs / nfs / dir.c
blob7237672216c804769b945c9b09b1e57e1b3de202
1 /*
2 * linux/fs/nfs/dir.c
4 * Copyright (C) 1992 Rick Sladkey
6 * nfs directory handling functions
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
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>
39 #include "delegation.h"
40 #include "iostat.h"
41 #include "internal.h"
42 #include "fscache.h"
44 /* #define NFS_DEBUG_VERBOSE 1 */
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*);
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,
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,
87 const struct address_space_operations nfs_dir_aops = {
88 .freepage = nfs_readdir_clear_array,
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,
110 #endif /* CONFIG_NFS_V3 */
112 #ifdef CONFIG_NFS_V4
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,
135 #endif /* CONFIG_NFS_V4 */
137 static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct rpc_cred *cred)
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;
151 static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
153 put_rpccred(ctx->cred);
154 kfree(ctx);
158 * Open file
160 static int
161 nfs_opendir(struct inode *inode, struct file *filp)
163 int res = 0;
164 struct nfs_open_dir_context *ctx;
165 struct rpc_cred *cred;
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);
171 nfs_inc_stats(inode, NFSIOS_VFSOPEN);
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;
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.
187 __nfs_revalidate_inode(NFS_SERVER(inode), inode);
189 out:
190 put_rpccred(cred);
191 return res;
194 static int
195 nfs_closedir(struct inode *inode, struct file *filp)
197 put_nfs_open_dir_context(filp->private_data);
198 return 0;
201 struct nfs_cache_array_entry {
202 u64 cookie;
203 u64 ino;
204 struct qstr string;
205 unsigned char d_type;
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];
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;
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;
233 * The caller is responsible for calling nfs_readdir_release_array(page)
235 static
236 struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
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;
247 static
248 void nfs_readdir_release_array(struct page *page)
250 kunmap(page);
254 * we are freeing strings created by nfs_add_to_readdir_array()
256 static
257 void nfs_readdir_clear_array(struct page *page)
259 struct nfs_cache_array *array;
260 int i;
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);
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()
273 static
274 int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
276 string->len = len;
277 string->name = kmemdup(name, len, GFP_KERNEL);
278 if (string->name == NULL)
279 return -ENOMEM;
281 * Avoid a kmemleak false positive. The pointer to the name is stored
282 * in a page cache page which kmemleak does not scan.
284 kmemleak_not_leak(string->name);
285 string->hash = full_name_hash(name, len);
286 return 0;
289 static
290 int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
292 struct nfs_cache_array *array = nfs_readdir_get_array(page);
293 struct nfs_cache_array_entry *cache_entry;
294 int ret;
296 if (IS_ERR(array))
297 return PTR_ERR(array);
299 cache_entry = &array->array[array->size];
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;
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;
321 static
322 int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
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;
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;
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;
346 static
347 int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
349 int i;
350 loff_t new_pos;
351 int status = -EAGAIN;
352 struct nfs_open_dir_context *ctx = desc->file->private_data;
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;
361 desc->file->f_pos = new_pos;
362 desc->cache_entry_index = i;
363 return 0;
366 if (array->eof_index >= 0) {
367 status = -EBADCOOKIE;
368 if (*desc->dir_cookie == array->last_cookie)
369 desc->eof = 1;
371 return status;
374 static
375 int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
377 struct nfs_cache_array *array;
378 int status;
380 array = nfs_readdir_get_array(desc->page);
381 if (IS_ERR(array)) {
382 status = PTR_ERR(array);
383 goto out;
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);
391 if (status == -EAGAIN) {
392 desc->last_cookie = array->last_cookie;
393 desc->current_index += array->size;
394 desc->page_index++;
396 nfs_readdir_release_array(desc->page);
397 out:
398 return status;
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)
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;
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;
424 goto error;
426 desc->timestamp = timestamp;
427 desc->gencount = gencount;
428 error:
429 return error;
432 static int xdr_decode(nfs_readdir_descriptor_t *desc,
433 struct nfs_entry *entry, struct xdr_stream *xdr)
435 int error;
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;
445 static
446 int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
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;
457 static
458 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
460 struct qstr filename = {
461 .len = entry->len,
462 .name = entry->name,
464 struct dentry *dentry;
465 struct dentry *alias;
466 struct inode *dir = parent->d_inode;
467 struct inode *inode;
469 if (filename.name[0] == '.') {
470 if (filename.len == 1)
471 return;
472 if (filename.len == 2 && filename.name[1] == '.')
473 return;
475 filename.hash = full_name_hash(filename.name, filename.len);
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);
488 dentry = d_alloc(parent, &filename);
489 if (dentry == NULL)
490 return;
492 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
493 if (IS_ERR(inode))
494 goto out;
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));
505 out:
506 dput(dentry);
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)
514 struct xdr_stream stream;
515 struct xdr_buf buf = {
516 .pages = xdr_pages,
517 .page_len = buflen,
518 .buflen = buflen,
519 .len = buflen,
521 struct page *scratch;
522 struct nfs_cache_array *array;
523 unsigned int count = 0;
524 int status;
526 scratch = alloc_page(GFP_KERNEL);
527 if (scratch == NULL)
528 return -ENOMEM;
530 xdr_init_decode(&stream, &buf, NULL);
531 xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
533 do {
534 status = xdr_decode(desc, entry, &stream);
535 if (status != 0) {
536 if (status == -EAGAIN)
537 status = 0;
538 break;
541 count++;
543 if (desc->plus != 0)
544 nfs_prime_dcache(desc->file->f_path.dentry, entry);
546 status = nfs_readdir_add_to_array(entry, page);
547 if (status != 0)
548 break;
549 } while (!entry->eof);
551 if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
552 array = nfs_readdir_get_array(page);
553 if (!IS_ERR(array)) {
554 array->eof_index = array->size;
555 status = 0;
556 nfs_readdir_release_array(page);
557 } else
558 status = PTR_ERR(array);
561 put_page(scratch);
562 return status;
565 static
566 void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
568 unsigned int i;
569 for (i = 0; i < npages; i++)
570 put_page(pages[i]);
573 static
574 void nfs_readdir_free_large_page(void *ptr, struct page **pages,
575 unsigned int npages)
577 nfs_readdir_free_pagearray(pages, npages);
581 * nfs_readdir_large_page will allocate pages that must be freed with a call
582 * to nfs_readdir_free_large_page
584 static
585 int nfs_readdir_large_page(struct page **pages, unsigned int npages)
587 unsigned int i;
589 for (i = 0; i < npages; i++) {
590 struct page *page = alloc_page(GFP_KERNEL);
591 if (page == NULL)
592 goto out_freepages;
593 pages[i] = page;
595 return 0;
597 out_freepages:
598 nfs_readdir_free_pagearray(pages, i);
599 return -ENOMEM;
602 static
603 int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
605 struct page *pages[NFS_MAX_READDIR_PAGES];
606 void *pages_ptr = NULL;
607 struct nfs_entry entry;
608 struct file *file = desc->file;
609 struct nfs_cache_array *array;
610 int status = -ENOMEM;
611 unsigned int array_size = ARRAY_SIZE(pages);
613 entry.prev_cookie = 0;
614 entry.cookie = desc->last_cookie;
615 entry.eof = 0;
616 entry.fh = nfs_alloc_fhandle();
617 entry.fattr = nfs_alloc_fattr();
618 entry.server = NFS_SERVER(inode);
619 if (entry.fh == NULL || entry.fattr == NULL)
620 goto out;
622 array = nfs_readdir_get_array(page);
623 if (IS_ERR(array)) {
624 status = PTR_ERR(array);
625 goto out;
627 memset(array, 0, sizeof(struct nfs_cache_array));
628 array->eof_index = -1;
630 status = nfs_readdir_large_page(pages, array_size);
631 if (status < 0)
632 goto out_release_array;
633 do {
634 unsigned int pglen;
635 status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
637 if (status < 0)
638 break;
639 pglen = status;
640 status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
641 if (status < 0) {
642 if (status == -ENOSPC)
643 status = 0;
644 break;
646 } while (array->eof_index < 0);
648 nfs_readdir_free_large_page(pages_ptr, pages, array_size);
649 out_release_array:
650 nfs_readdir_release_array(page);
651 out:
652 nfs_free_fattr(entry.fattr);
653 nfs_free_fhandle(entry.fh);
654 return status;
658 * Now we cache directories properly, by converting xdr information
659 * to an array that can be used for lookups later. This results in
660 * fewer cache pages, since we can store more information on each page.
661 * We only need to convert from xdr once so future lookups are much simpler
663 static
664 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
666 struct inode *inode = desc->file->f_path.dentry->d_inode;
667 int ret;
669 ret = nfs_readdir_xdr_to_array(desc, page, inode);
670 if (ret < 0)
671 goto error;
672 SetPageUptodate(page);
674 if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
675 /* Should never happen */
676 nfs_zap_mapping(inode, inode->i_mapping);
678 unlock_page(page);
679 return 0;
680 error:
681 unlock_page(page);
682 return ret;
685 static
686 void cache_page_release(nfs_readdir_descriptor_t *desc)
688 if (!desc->page->mapping)
689 nfs_readdir_clear_array(desc->page);
690 page_cache_release(desc->page);
691 desc->page = NULL;
694 static
695 struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
697 return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,
698 desc->page_index, (filler_t *)nfs_readdir_filler, desc);
702 * Returns 0 if desc->dir_cookie was found on page desc->page_index
704 static
705 int find_cache_page(nfs_readdir_descriptor_t *desc)
707 int res;
709 desc->page = get_cache_page(desc);
710 if (IS_ERR(desc->page))
711 return PTR_ERR(desc->page);
713 res = nfs_readdir_search_array(desc);
714 if (res != 0)
715 cache_page_release(desc);
716 return res;
719 /* Search for desc->dir_cookie from the beginning of the page cache */
720 static inline
721 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
723 int res;
725 if (desc->page_index == 0) {
726 desc->current_index = 0;
727 desc->last_cookie = 0;
729 do {
730 res = find_cache_page(desc);
731 } while (res == -EAGAIN);
732 return res;
736 * Once we've found the start of the dirent within a page: fill 'er up...
738 static
739 int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
740 filldir_t filldir)
742 struct file *file = desc->file;
743 int i = 0;
744 int res = 0;
745 struct nfs_cache_array *array = NULL;
746 struct nfs_open_dir_context *ctx = file->private_data;
748 if (ctx->duped != 0 && ctx->dup_cookie == *desc->dir_cookie) {
749 if (printk_ratelimit()) {
750 pr_notice("NFS: directory %s/%s contains a readdir loop. "
751 "Please contact your server vendor. "
752 "Offending cookie: %llu\n",
753 file->f_dentry->d_parent->d_name.name,
754 file->f_dentry->d_name.name,
755 *desc->dir_cookie);
757 res = -ELOOP;
758 goto out;
761 array = nfs_readdir_get_array(desc->page);
762 if (IS_ERR(array)) {
763 res = PTR_ERR(array);
764 goto out;
767 for (i = desc->cache_entry_index; i < array->size; i++) {
768 struct nfs_cache_array_entry *ent;
770 ent = &array->array[i];
771 if (filldir(dirent, ent->string.name, ent->string.len,
772 file->f_pos, nfs_compat_user_ino64(ent->ino),
773 ent->d_type) < 0) {
774 desc->eof = 1;
775 break;
777 file->f_pos++;
778 if (i < (array->size-1))
779 *desc->dir_cookie = array->array[i+1].cookie;
780 else
781 *desc->dir_cookie = array->last_cookie;
783 if (array->eof_index >= 0)
784 desc->eof = 1;
786 nfs_readdir_release_array(desc->page);
787 out:
788 cache_page_release(desc);
789 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
790 (unsigned long long)*desc->dir_cookie, res);
791 return res;
795 * If we cannot find a cookie in our cache, we suspect that this is
796 * because it points to a deleted file, so we ask the server to return
797 * whatever it thinks is the next entry. We then feed this to filldir.
798 * If all goes well, we should then be able to find our way round the
799 * cache on the next call to readdir_search_pagecache();
801 * NOTE: we cannot add the anonymous page to the pagecache because
802 * the data it contains might not be page aligned. Besides,
803 * we should already have a complete representation of the
804 * directory in the page cache by the time we get here.
806 static inline
807 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
808 filldir_t filldir)
810 struct page *page = NULL;
811 int status;
812 struct inode *inode = desc->file->f_path.dentry->d_inode;
814 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
815 (unsigned long long)*desc->dir_cookie);
817 page = alloc_page(GFP_HIGHUSER);
818 if (!page) {
819 status = -ENOMEM;
820 goto out;
823 desc->page_index = 0;
824 desc->last_cookie = *desc->dir_cookie;
825 desc->page = page;
827 status = nfs_readdir_xdr_to_array(desc, page, inode);
828 if (status < 0)
829 goto out_release;
831 status = nfs_do_filldir(desc, dirent, filldir);
833 out:
834 dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
835 __func__, status);
836 return status;
837 out_release:
838 cache_page_release(desc);
839 goto out;
842 /* The file offset position represents the dirent entry number. A
843 last cookie cache takes care of the common case of reading the
844 whole directory.
846 static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
848 struct dentry *dentry = filp->f_path.dentry;
849 struct inode *inode = dentry->d_inode;
850 nfs_readdir_descriptor_t my_desc,
851 *desc = &my_desc;
852 struct nfs_open_dir_context *dir_ctx = filp->private_data;
853 int res;
855 dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
856 dentry->d_parent->d_name.name, dentry->d_name.name,
857 (long long)filp->f_pos);
858 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
861 * filp->f_pos points to the dirent entry number.
862 * *desc->dir_cookie has the cookie for the next entry. We have
863 * to either find the entry with the appropriate number or
864 * revalidate the cookie.
866 memset(desc, 0, sizeof(*desc));
868 desc->file = filp;
869 desc->dir_cookie = &dir_ctx->dir_cookie;
870 desc->decode = NFS_PROTO(inode)->decode_dirent;
871 desc->plus = NFS_USE_READDIRPLUS(inode);
873 nfs_block_sillyrename(dentry);
874 res = nfs_revalidate_mapping(inode, filp->f_mapping);
875 if (res < 0)
876 goto out;
878 do {
879 res = readdir_search_pagecache(desc);
881 if (res == -EBADCOOKIE) {
882 res = 0;
883 /* This means either end of directory */
884 if (*desc->dir_cookie && desc->eof == 0) {
885 /* Or that the server has 'lost' a cookie */
886 res = uncached_readdir(desc, dirent, filldir);
887 if (res == 0)
888 continue;
890 break;
892 if (res == -ETOOSMALL && desc->plus) {
893 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
894 nfs_zap_caches(inode);
895 desc->page_index = 0;
896 desc->plus = 0;
897 desc->eof = 0;
898 continue;
900 if (res < 0)
901 break;
903 res = nfs_do_filldir(desc, dirent, filldir);
904 if (res < 0)
905 break;
906 } while (!desc->eof);
907 out:
908 nfs_unblock_sillyrename(dentry);
909 if (res > 0)
910 res = 0;
911 dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
912 dentry->d_parent->d_name.name, dentry->d_name.name,
913 res);
914 return res;
917 static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
919 struct dentry *dentry = filp->f_path.dentry;
920 struct inode *inode = dentry->d_inode;
921 struct nfs_open_dir_context *dir_ctx = filp->private_data;
923 dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
924 dentry->d_parent->d_name.name,
925 dentry->d_name.name,
926 offset, origin);
928 mutex_lock(&inode->i_mutex);
929 switch (origin) {
930 case 1:
931 offset += filp->f_pos;
932 case 0:
933 if (offset >= 0)
934 break;
935 default:
936 offset = -EINVAL;
937 goto out;
939 if (offset != filp->f_pos) {
940 filp->f_pos = offset;
941 dir_ctx->dir_cookie = 0;
942 dir_ctx->duped = 0;
944 out:
945 mutex_unlock(&inode->i_mutex);
946 return offset;
950 * All directory operations under NFS are synchronous, so fsync()
951 * is a dummy operation.
953 static int nfs_fsync_dir(struct file *filp, int datasync)
955 struct dentry *dentry = filp->f_path.dentry;
957 dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
958 dentry->d_parent->d_name.name, dentry->d_name.name,
959 datasync);
961 nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
962 return 0;
966 * nfs_force_lookup_revalidate - Mark the directory as having changed
967 * @dir - pointer to directory inode
969 * This forces the revalidation code in nfs_lookup_revalidate() to do a
970 * full lookup on all child dentries of 'dir' whenever a change occurs
971 * on the server that might have invalidated our dcache.
973 * The caller should be holding dir->i_lock
975 void nfs_force_lookup_revalidate(struct inode *dir)
977 NFS_I(dir)->cache_change_attribute++;
981 * A check for whether or not the parent directory has changed.
982 * In the case it has, we assume that the dentries are untrustworthy
983 * and may need to be looked up again.
985 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
987 if (IS_ROOT(dentry))
988 return 1;
989 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
990 return 0;
991 if (!nfs_verify_change_attribute(dir, dentry->d_time))
992 return 0;
993 /* Revalidate nfsi->cache_change_attribute before we declare a match */
994 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
995 return 0;
996 if (!nfs_verify_change_attribute(dir, dentry->d_time))
997 return 0;
998 return 1;
1002 * Return the intent data that applies to this particular path component
1004 * Note that the current set of intents only apply to the very last
1005 * component of the path.
1006 * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
1008 static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
1009 unsigned int mask)
1011 if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
1012 return 0;
1013 return nd->flags & mask;
1017 * Use intent information to check whether or not we're going to do
1018 * an O_EXCL create using this path component.
1020 static int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
1022 if (NFS_PROTO(dir)->version == 2)
1023 return 0;
1024 return nd && nfs_lookup_check_intent(nd, LOOKUP_EXCL);
1028 * Inode and filehandle revalidation for lookups.
1030 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
1031 * or if the intent information indicates that we're about to open this
1032 * particular file and the "nocto" mount flag is not set.
1035 static inline
1036 int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
1038 struct nfs_server *server = NFS_SERVER(inode);
1040 if (IS_AUTOMOUNT(inode))
1041 return 0;
1042 if (nd != NULL) {
1043 /* VFS wants an on-the-wire revalidation */
1044 if (nd->flags & LOOKUP_REVAL)
1045 goto out_force;
1046 /* This is an open(2) */
1047 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
1048 !(server->flags & NFS_MOUNT_NOCTO) &&
1049 (S_ISREG(inode->i_mode) ||
1050 S_ISDIR(inode->i_mode)))
1051 goto out_force;
1052 return 0;
1054 return nfs_revalidate_inode(server, inode);
1055 out_force:
1056 return __nfs_revalidate_inode(server, inode);
1060 * We judge how long we want to trust negative
1061 * dentries by looking at the parent inode mtime.
1063 * If parent mtime has changed, we revalidate, else we wait for a
1064 * period corresponding to the parent's attribute cache timeout value.
1066 static inline
1067 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
1068 struct nameidata *nd)
1070 /* Don't revalidate a negative dentry if we're creating a new file */
1071 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
1072 return 0;
1073 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
1074 return 1;
1075 return !nfs_check_verifier(dir, dentry);
1079 * This is called every time the dcache has a lookup hit,
1080 * and we should check whether we can really trust that
1081 * lookup.
1083 * NOTE! The hit can be a negative hit too, don't assume
1084 * we have an inode!
1086 * If the parent directory is seen to have changed, we throw out the
1087 * cached dentry and do a new lookup.
1089 static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
1091 struct inode *dir;
1092 struct inode *inode;
1093 struct dentry *parent;
1094 struct nfs_fh *fhandle = NULL;
1095 struct nfs_fattr *fattr = NULL;
1096 int error;
1098 if (nd->flags & LOOKUP_RCU)
1099 return -ECHILD;
1101 parent = dget_parent(dentry);
1102 dir = parent->d_inode;
1103 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
1104 inode = dentry->d_inode;
1106 if (!inode) {
1107 if (nfs_neg_need_reval(dir, dentry, nd))
1108 goto out_bad;
1109 goto out_valid;
1112 if (is_bad_inode(inode)) {
1113 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1114 __func__, dentry->d_parent->d_name.name,
1115 dentry->d_name.name);
1116 goto out_bad;
1119 if (nfs_have_delegation(inode, FMODE_READ))
1120 goto out_set_verifier;
1122 /* Force a full look up iff the parent directory has changed */
1123 if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) {
1124 if (nfs_lookup_verify_inode(inode, nd))
1125 goto out_zap_parent;
1126 goto out_valid;
1129 if (NFS_STALE(inode))
1130 goto out_bad;
1132 error = -ENOMEM;
1133 fhandle = nfs_alloc_fhandle();
1134 fattr = nfs_alloc_fattr();
1135 if (fhandle == NULL || fattr == NULL)
1136 goto out_error;
1138 error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
1139 if (error)
1140 goto out_bad;
1141 if (nfs_compare_fh(NFS_FH(inode), fhandle))
1142 goto out_bad;
1143 if ((error = nfs_refresh_inode(inode, fattr)) != 0)
1144 goto out_bad;
1146 nfs_free_fattr(fattr);
1147 nfs_free_fhandle(fhandle);
1148 out_set_verifier:
1149 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1150 out_valid:
1151 dput(parent);
1152 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
1153 __func__, dentry->d_parent->d_name.name,
1154 dentry->d_name.name);
1155 return 1;
1156 out_zap_parent:
1157 nfs_zap_caches(dir);
1158 out_bad:
1159 nfs_mark_for_revalidate(dir);
1160 if (inode && S_ISDIR(inode->i_mode)) {
1161 /* Purge readdir caches. */
1162 nfs_zap_caches(inode);
1163 /* If we have submounts, don't unhash ! */
1164 if (have_submounts(dentry))
1165 goto out_valid;
1166 if (dentry->d_flags & DCACHE_DISCONNECTED)
1167 goto out_valid;
1168 shrink_dcache_parent(dentry);
1170 d_drop(dentry);
1171 nfs_free_fattr(fattr);
1172 nfs_free_fhandle(fhandle);
1173 dput(parent);
1174 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
1175 __func__, dentry->d_parent->d_name.name,
1176 dentry->d_name.name);
1177 return 0;
1178 out_error:
1179 nfs_free_fattr(fattr);
1180 nfs_free_fhandle(fhandle);
1181 dput(parent);
1182 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n",
1183 __func__, dentry->d_parent->d_name.name,
1184 dentry->d_name.name, error);
1185 return error;
1189 * This is called from dput() when d_count is going to 0.
1191 static int nfs_dentry_delete(const struct dentry *dentry)
1193 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
1194 dentry->d_parent->d_name.name, dentry->d_name.name,
1195 dentry->d_flags);
1197 /* Unhash any dentry with a stale inode */
1198 if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode))
1199 return 1;
1201 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1202 /* Unhash it, so that ->d_iput() would be called */
1203 return 1;
1205 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
1206 /* Unhash it, so that ancestors of killed async unlink
1207 * files will be cleaned up during umount */
1208 return 1;
1210 return 0;
1214 static void nfs_drop_nlink(struct inode *inode)
1216 spin_lock(&inode->i_lock);
1217 if (inode->i_nlink > 0)
1218 drop_nlink(inode);
1219 spin_unlock(&inode->i_lock);
1223 * Called when the dentry loses inode.
1224 * We use it to clean up silly-renamed files.
1226 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
1228 if (S_ISDIR(inode->i_mode))
1229 /* drop any readdir cache as it could easily be old */
1230 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
1232 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1233 drop_nlink(inode);
1234 nfs_complete_unlink(dentry, inode);
1236 iput(inode);
1239 static void nfs_d_release(struct dentry *dentry)
1241 /* free cached devname value, if it survived that far */
1242 if (unlikely(dentry->d_fsdata)) {
1243 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1244 WARN_ON(1);
1245 else
1246 kfree(dentry->d_fsdata);
1250 const struct dentry_operations nfs_dentry_operations = {
1251 .d_revalidate = nfs_lookup_revalidate,
1252 .d_delete = nfs_dentry_delete,
1253 .d_iput = nfs_dentry_iput,
1254 .d_automount = nfs_d_automount,
1255 .d_release = nfs_d_release,
1258 static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
1260 struct dentry *res;
1261 struct dentry *parent;
1262 struct inode *inode = NULL;
1263 struct nfs_fh *fhandle = NULL;
1264 struct nfs_fattr *fattr = NULL;
1265 int error;
1267 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
1268 dentry->d_parent->d_name.name, dentry->d_name.name);
1269 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
1271 res = ERR_PTR(-ENAMETOOLONG);
1272 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
1273 goto out;
1276 * If we're doing an exclusive create, optimize away the lookup
1277 * but don't hash the dentry.
1279 if (nfs_is_exclusive_create(dir, nd)) {
1280 d_instantiate(dentry, NULL);
1281 res = NULL;
1282 goto out;
1285 res = ERR_PTR(-ENOMEM);
1286 fhandle = nfs_alloc_fhandle();
1287 fattr = nfs_alloc_fattr();
1288 if (fhandle == NULL || fattr == NULL)
1289 goto out;
1291 parent = dentry->d_parent;
1292 /* Protect against concurrent sillydeletes */
1293 nfs_block_sillyrename(parent);
1294 error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr);
1295 if (error == -ENOENT)
1296 goto no_entry;
1297 if (error < 0) {
1298 res = ERR_PTR(error);
1299 goto out_unblock_sillyrename;
1301 inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1302 res = ERR_CAST(inode);
1303 if (IS_ERR(res))
1304 goto out_unblock_sillyrename;
1306 no_entry:
1307 res = d_materialise_unique(dentry, inode);
1308 if (res != NULL) {
1309 if (IS_ERR(res))
1310 goto out_unblock_sillyrename;
1311 dentry = res;
1313 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1314 out_unblock_sillyrename:
1315 nfs_unblock_sillyrename(parent);
1316 out:
1317 nfs_free_fattr(fattr);
1318 nfs_free_fhandle(fhandle);
1319 return res;
1322 #ifdef CONFIG_NFS_V4
1323 static int nfs_open_revalidate(struct dentry *, struct nameidata *);
1325 const struct dentry_operations nfs4_dentry_operations = {
1326 .d_revalidate = nfs_open_revalidate,
1327 .d_delete = nfs_dentry_delete,
1328 .d_iput = nfs_dentry_iput,
1329 .d_automount = nfs_d_automount,
1330 .d_release = nfs_d_release,
1334 * Use intent information to determine whether we need to substitute
1335 * the NFSv4-style stateful OPEN for the LOOKUP call
1337 static int is_atomic_open(struct nameidata *nd)
1339 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
1340 return 0;
1341 /* NFS does not (yet) have a stateful open for directories */
1342 if (nd->flags & LOOKUP_DIRECTORY)
1343 return 0;
1344 /* Are we trying to write to a read only partition? */
1345 if (__mnt_is_readonly(nd->path.mnt) &&
1346 (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE)))
1347 return 0;
1348 return 1;
1351 static struct nfs_open_context *nameidata_to_nfs_open_context(struct dentry *dentry, struct nameidata *nd)
1353 struct path path = {
1354 .mnt = nd->path.mnt,
1355 .dentry = dentry,
1357 struct nfs_open_context *ctx;
1358 struct rpc_cred *cred;
1359 fmode_t fmode = nd->intent.open.flags & (FMODE_READ | FMODE_WRITE | FMODE_EXEC);
1361 cred = rpc_lookup_cred();
1362 if (IS_ERR(cred))
1363 return ERR_CAST(cred);
1364 ctx = alloc_nfs_open_context(&path, cred, fmode);
1365 put_rpccred(cred);
1366 if (ctx == NULL)
1367 return ERR_PTR(-ENOMEM);
1368 return ctx;
1371 static int do_open(struct inode *inode, struct file *filp)
1373 nfs_fscache_set_inode_cookie(inode, filp);
1374 return 0;
1377 static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx)
1379 struct file *filp;
1380 int ret = 0;
1382 /* If the open_intent is for execute, we have an extra check to make */
1383 if (ctx->mode & FMODE_EXEC) {
1384 ret = nfs_may_open(ctx->path.dentry->d_inode,
1385 ctx->cred,
1386 nd->intent.open.flags);
1387 if (ret < 0)
1388 goto out;
1390 filp = lookup_instantiate_filp(nd, ctx->path.dentry, do_open);
1391 if (IS_ERR(filp))
1392 ret = PTR_ERR(filp);
1393 else
1394 nfs_file_set_open_context(filp, ctx);
1395 out:
1396 put_nfs_open_context(ctx);
1397 return ret;
1400 static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
1402 struct nfs_open_context *ctx;
1403 struct iattr attr;
1404 struct dentry *res = NULL;
1405 struct inode *inode;
1406 int open_flags;
1407 int err;
1409 dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
1410 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1412 /* Check that we are indeed trying to open this file */
1413 if (!is_atomic_open(nd))
1414 goto no_open;
1416 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
1417 res = ERR_PTR(-ENAMETOOLONG);
1418 goto out;
1421 /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash
1422 * the dentry. */
1423 if (nd->flags & LOOKUP_EXCL) {
1424 d_instantiate(dentry, NULL);
1425 goto out;
1428 ctx = nameidata_to_nfs_open_context(dentry, nd);
1429 res = ERR_CAST(ctx);
1430 if (IS_ERR(ctx))
1431 goto out;
1433 open_flags = nd->intent.open.flags;
1434 if (nd->flags & LOOKUP_CREATE) {
1435 attr.ia_mode = nd->intent.open.create_mode;
1436 attr.ia_valid = ATTR_MODE;
1437 attr.ia_mode &= ~current_umask();
1438 } else {
1439 open_flags &= ~(O_EXCL | O_CREAT);
1440 attr.ia_valid = 0;
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;
1468 res = d_add_unique(dentry, inode);
1469 nfs_unblock_sillyrename(dentry->d_parent);
1470 if (res != NULL) {
1471 dput(ctx->path.dentry);
1472 ctx->path.dentry = dget(res);
1473 dentry = res;
1475 err = nfs_intent_set_file(nd, ctx);
1476 if (err < 0) {
1477 if (res != NULL)
1478 dput(res);
1479 return ERR_PTR(err);
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);
1488 static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
1490 struct dentry *parent = NULL;
1491 struct inode *inode;
1492 struct inode *dir;
1493 struct nfs_open_context *ctx;
1494 int openflags, ret = 0;
1496 if (nd->flags & LOOKUP_RCU)
1497 return -ECHILD;
1499 inode = dentry->d_inode;
1500 if (!is_atomic_open(nd) || d_mountpoint(dentry))
1501 goto no_open;
1503 parent = dget_parent(dentry);
1504 dir = parent->d_inode;
1506 /* We can't create new files in nfs_open_revalidate(), so we
1507 * optimize away revalidation of negative dentries.
1509 if (inode == NULL) {
1510 if (!nfs_neg_need_reval(dir, dentry, nd))
1511 ret = 1;
1512 goto out;
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);
1525 ctx = nameidata_to_nfs_open_context(dentry, nd);
1526 ret = PTR_ERR(ctx);
1527 if (IS_ERR(ctx))
1528 goto out;
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.
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;
1548 iput(inode);
1549 if (inode != dentry->d_inode)
1550 goto out_drop;
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;
1566 no_open_dput:
1567 dput(parent);
1568 no_open:
1569 return nfs_lookup_revalidate(dentry, nd);
1572 static int nfs_open_create(struct inode *dir, struct dentry *dentry, int mode,
1573 struct nameidata *nd)
1575 struct nfs_open_context *ctx = NULL;
1576 struct iattr attr;
1577 int error;
1578 int open_flags = 0;
1580 dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
1581 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1583 attr.ia_mode = mode;
1584 attr.ia_valid = ATTR_MODE;
1586 if ((nd->flags & LOOKUP_CREATE) != 0) {
1587 open_flags = nd->intent.open.flags;
1589 ctx = nameidata_to_nfs_open_context(dentry, nd);
1590 error = PTR_ERR(ctx);
1591 if (IS_ERR(ctx))
1592 goto out_err_drop;
1595 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx);
1596 if (error != 0)
1597 goto out_put_ctx;
1598 if (ctx != NULL) {
1599 error = nfs_intent_set_file(nd, ctx);
1600 if (error < 0)
1601 goto out_err;
1603 return 0;
1604 out_put_ctx:
1605 if (ctx != NULL)
1606 put_nfs_open_context(ctx);
1607 out_err_drop:
1608 d_drop(dentry);
1609 out_err:
1610 return error;
1613 #endif /* CONFIG_NFSV4 */
1616 * Code common to create, mkdir, and mknod.
1618 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1619 struct nfs_fattr *fattr)
1621 struct dentry *parent = dget_parent(dentry);
1622 struct inode *dir = parent->d_inode;
1623 struct inode *inode;
1624 int error = -EACCES;
1626 d_drop(dentry);
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;
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;
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;
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.
1663 static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
1664 struct nameidata *nd)
1666 struct iattr attr;
1667 int error;
1668 int open_flags = 0;
1670 dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
1671 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1673 attr.ia_mode = mode;
1674 attr.ia_valid = ATTR_MODE;
1676 if ((nd->flags & LOOKUP_CREATE) != 0)
1677 open_flags = nd->intent.open.flags;
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;
1689 * See comments for nfs_proc_create regarding failed operations.
1691 static int
1692 nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1694 struct iattr attr;
1695 int status;
1697 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
1698 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1700 if (!new_valid_dev(rdev))
1701 return -EINVAL;
1703 attr.ia_mode = mode;
1704 attr.ia_valid = ATTR_MODE;
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;
1716 * See comments for nfs_proc_create regarding failed operations.
1718 static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1720 struct iattr attr;
1721 int error;
1723 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
1724 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1726 attr.ia_valid = ATTR_MODE;
1727 attr.ia_mode = mode | S_IFDIR;
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;
1738 static void nfs_dentry_handle_enoent(struct dentry *dentry)
1740 if (dentry->d_inode != NULL && !d_unhashed(dentry))
1741 d_delete(dentry);
1744 static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1746 int error;
1748 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
1749 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
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);
1758 return error;
1762 * Remove a file after making sure there are no pending writes,
1763 * and after checking that the file has only one user.
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.
1768 static int nfs_safe_remove(struct dentry *dentry)
1770 struct inode *dir = dentry->d_parent->d_inode;
1771 struct inode *inode = dentry->d_inode;
1772 int error = -EBUSY;
1774 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1775 dentry->d_parent->d_name.name, dentry->d_name.name);
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;
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;
1798 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1799 * belongs to an active ".nfs..." file and we return -EBUSY.
1801 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1803 static int nfs_unlink(struct inode *dir, struct dentry *dentry)
1805 int error;
1806 int need_rehash = 0;
1808 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1809 dir->i_ino, dentry->d_name.name);
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;
1819 if (!d_unhashed(dentry)) {
1820 __d_drop(dentry);
1821 need_rehash = 1;
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;
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.
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.
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.
1847 static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
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;
1856 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1857 dir->i_ino, dentry->d_name.name, symname);
1859 if (pathlen > PAGE_SIZE)
1860 return -ENAMETOOLONG;
1862 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1863 attr.ia_valid = ATTR_MODE;
1865 page = alloc_page(GFP_HIGHUSER);
1866 if (!page)
1867 return -ENOMEM;
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);
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;
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.
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);
1899 return 0;
1902 static int
1903 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1905 struct inode *inode = old_dentry->d_inode;
1906 int error;
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);
1912 nfs_inode_return_delegation(inode);
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);
1920 return error;
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.
1932 * FIXED.
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
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.
1947 static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1948 struct inode *new_dir, struct dentry *new_dentry)
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;
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);
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.
1966 if (new_inode && !S_ISDIR(new_inode->i_mode)) {
1968 * To prevent any new references to the target during the
1969 * rename, we unhash the dentry in advance.
1971 if (!d_unhashed(new_dentry)) {
1972 d_drop(new_dentry);
1973 rehash = new_dentry;
1976 if (new_dentry->d_count > 2) {
1977 int err;
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;
1985 /* silly-rename the existing target ... */
1986 err = nfs_sillyrename(new_dir, new_dentry);
1987 if (err)
1988 goto out;
1990 new_dentry = dentry;
1991 rehash = NULL;
1992 new_inode = NULL;
1996 nfs_inode_return_delegation(old_inode);
1997 if (new_inode != NULL)
1998 nfs_inode_return_delegation(new_inode);
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);
2015 /* new dentry created? */
2016 if (dentry)
2017 dput(dentry);
2018 return error;
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;
2025 static void nfs_access_free_entry(struct nfs_access_entry *entry)
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();
2034 static void nfs_access_free_list(struct list_head *head)
2036 struct nfs_access_entry *cache;
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);
2045 int nfs_access_cache_shrinker(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask)
2047 LIST_HEAD(head);
2048 struct nfs_inode *nfsi, *next;
2049 struct nfs_access_entry *cache;
2051 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
2052 return (nr_to_scan == 0) ? 0 : -1;
2054 spin_lock(&nfs_access_lru_lock);
2055 list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
2056 struct inode *inode;
2058 if (nr_to_scan-- == 0)
2059 break;
2060 inode = &nfsi->vfs_inode;
2061 spin_lock(&inode->i_lock);
2062 if (list_empty(&nfsi->access_cache_entry_lru))
2063 goto remove_lru_entry;
2064 cache = list_entry(nfsi->access_cache_entry_lru.next,
2065 struct nfs_access_entry, lru);
2066 list_move(&cache->lru, &head);
2067 rb_erase(&cache->rb_node, &nfsi->access_cache);
2068 if (!list_empty(&nfsi->access_cache_entry_lru))
2069 list_move_tail(&nfsi->access_cache_inode_lru,
2070 &nfs_access_lru_list);
2071 else {
2072 remove_lru_entry:
2073 list_del_init(&nfsi->access_cache_inode_lru);
2074 smp_mb__before_clear_bit();
2075 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
2076 smp_mb__after_clear_bit();
2078 spin_unlock(&inode->i_lock);
2080 spin_unlock(&nfs_access_lru_lock);
2081 nfs_access_free_list(&head);
2082 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
2085 static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
2087 struct rb_root *root_node = &nfsi->access_cache;
2088 struct rb_node *n;
2089 struct nfs_access_entry *entry;
2091 /* Unhook entries from the cache */
2092 while ((n = rb_first(root_node)) != NULL) {
2093 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2094 rb_erase(n, root_node);
2095 list_move(&entry->lru, head);
2097 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
2100 void nfs_access_zap_cache(struct inode *inode)
2102 LIST_HEAD(head);
2104 if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
2105 return;
2106 /* Remove from global LRU init */
2107 spin_lock(&nfs_access_lru_lock);
2108 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2109 list_del_init(&NFS_I(inode)->access_cache_inode_lru);
2111 spin_lock(&inode->i_lock);
2112 __nfs_access_zap_cache(NFS_I(inode), &head);
2113 spin_unlock(&inode->i_lock);
2114 spin_unlock(&nfs_access_lru_lock);
2115 nfs_access_free_list(&head);
2118 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
2120 struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
2121 struct nfs_access_entry *entry;
2123 while (n != NULL) {
2124 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2126 if (cred < entry->cred)
2127 n = n->rb_left;
2128 else if (cred > entry->cred)
2129 n = n->rb_right;
2130 else
2131 return entry;
2133 return NULL;
2136 static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
2138 struct nfs_inode *nfsi = NFS_I(inode);
2139 struct nfs_access_entry *cache;
2140 int err = -ENOENT;
2142 spin_lock(&inode->i_lock);
2143 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
2144 goto out_zap;
2145 cache = nfs_access_search_rbtree(inode, cred);
2146 if (cache == NULL)
2147 goto out;
2148 if (!nfs_have_delegated_attributes(inode) &&
2149 !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
2150 goto out_stale;
2151 res->jiffies = cache->jiffies;
2152 res->cred = cache->cred;
2153 res->mask = cache->mask;
2154 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2155 err = 0;
2156 out:
2157 spin_unlock(&inode->i_lock);
2158 return err;
2159 out_stale:
2160 rb_erase(&cache->rb_node, &nfsi->access_cache);
2161 list_del(&cache->lru);
2162 spin_unlock(&inode->i_lock);
2163 nfs_access_free_entry(cache);
2164 return -ENOENT;
2165 out_zap:
2166 spin_unlock(&inode->i_lock);
2167 nfs_access_zap_cache(inode);
2168 return -ENOENT;
2171 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
2173 struct nfs_inode *nfsi = NFS_I(inode);
2174 struct rb_root *root_node = &nfsi->access_cache;
2175 struct rb_node **p = &root_node->rb_node;
2176 struct rb_node *parent = NULL;
2177 struct nfs_access_entry *entry;
2179 spin_lock(&inode->i_lock);
2180 while (*p != NULL) {
2181 parent = *p;
2182 entry = rb_entry(parent, struct nfs_access_entry, rb_node);
2184 if (set->cred < entry->cred)
2185 p = &parent->rb_left;
2186 else if (set->cred > entry->cred)
2187 p = &parent->rb_right;
2188 else
2189 goto found;
2191 rb_link_node(&set->rb_node, parent, p);
2192 rb_insert_color(&set->rb_node, root_node);
2193 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2194 spin_unlock(&inode->i_lock);
2195 return;
2196 found:
2197 rb_replace_node(parent, &set->rb_node, root_node);
2198 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2199 list_del(&entry->lru);
2200 spin_unlock(&inode->i_lock);
2201 nfs_access_free_entry(entry);
2204 static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2206 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
2207 if (cache == NULL)
2208 return;
2209 RB_CLEAR_NODE(&cache->rb_node);
2210 cache->jiffies = set->jiffies;
2211 cache->cred = get_rpccred(set->cred);
2212 cache->mask = set->mask;
2214 nfs_access_add_rbtree(inode, cache);
2216 /* Update accounting */
2217 smp_mb__before_atomic_inc();
2218 atomic_long_inc(&nfs_access_nr_entries);
2219 smp_mb__after_atomic_inc();
2221 /* Add inode to global LRU list */
2222 if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2223 spin_lock(&nfs_access_lru_lock);
2224 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2225 list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
2226 &nfs_access_lru_list);
2227 spin_unlock(&nfs_access_lru_lock);
2231 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
2233 struct nfs_access_entry cache;
2234 int status;
2236 status = nfs_access_get_cached(inode, cred, &cache);
2237 if (status == 0)
2238 goto out;
2240 /* Be clever: ask server to check for all possible rights */
2241 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
2242 cache.cred = cred;
2243 cache.jiffies = jiffies;
2244 status = NFS_PROTO(inode)->access(inode, &cache);
2245 if (status != 0) {
2246 if (status == -ESTALE) {
2247 nfs_zap_caches(inode);
2248 if (!S_ISDIR(inode->i_mode))
2249 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
2251 return status;
2253 nfs_access_add_cache(inode, &cache);
2254 out:
2255 if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2256 return 0;
2257 return -EACCES;
2260 static int nfs_open_permission_mask(int openflags)
2262 int mask = 0;
2264 if (openflags & FMODE_READ)
2265 mask |= MAY_READ;
2266 if (openflags & FMODE_WRITE)
2267 mask |= MAY_WRITE;
2268 if (openflags & FMODE_EXEC)
2269 mask |= MAY_EXEC;
2270 return mask;
2273 int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
2275 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
2278 int nfs_permission(struct inode *inode, int mask, unsigned int flags)
2280 struct rpc_cred *cred;
2281 int res = 0;
2283 if (flags & IPERM_FLAG_RCU)
2284 return -ECHILD;
2286 nfs_inc_stats(inode, NFSIOS_VFSACCESS);
2288 if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2289 goto out;
2290 /* Is this sys_access() ? */
2291 if (mask & (MAY_ACCESS | MAY_CHDIR))
2292 goto force_lookup;
2294 switch (inode->i_mode & S_IFMT) {
2295 case S_IFLNK:
2296 goto out;
2297 case S_IFREG:
2298 /* NFSv4 has atomic_open... */
2299 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
2300 && (mask & MAY_OPEN)
2301 && !(mask & MAY_EXEC))
2302 goto out;
2303 break;
2304 case S_IFDIR:
2306 * Optimize away all write operations, since the server
2307 * will check permissions when we perform the op.
2309 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
2310 goto out;
2313 force_lookup:
2314 if (!NFS_PROTO(inode)->access)
2315 goto out_notsup;
2317 cred = rpc_lookup_cred();
2318 if (!IS_ERR(cred)) {
2319 res = nfs_do_access(inode, cred, mask);
2320 put_rpccred(cred);
2321 } else
2322 res = PTR_ERR(cred);
2323 out:
2324 if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
2325 res = -EACCES;
2327 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
2328 inode->i_sb->s_id, inode->i_ino, mask, res);
2329 return res;
2330 out_notsup:
2331 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
2332 if (res == 0)
2333 res = generic_permission(inode, mask, flags, NULL);
2334 goto out;
2338 * Local variables:
2339 * version-control: t
2340 * kept-new-versions: 5
2341 * End: