1 // SPDX-License-Identifier: GPL-2.0-only
5 * Copyright (C) 1992 Rick Sladkey
7 * nfs directory handling functions
9 * 10 Apr 1996 Added silly rename for unlink --okir
10 * 28 Sep 1996 Improved directory cache --okir
11 * 23 Aug 1997 Claus Heine claus@momo.math.rwth-aachen.de
12 * Re-implemented silly rename for unlink, newly implemented
13 * silly rename for nfs_rename() following the suggestions
14 * of Olaf Kirch (okir) found in this file.
15 * Following Linus comments on my original hack, this version
16 * depends only on the dcache stuff and doesn't touch the inode
17 * layer (iput() and friends).
18 * 6 Jun 1999 Cache readdir lookups in the page cache. -DaveM
21 #include <linux/module.h>
22 #include <linux/time.h>
23 #include <linux/errno.h>
24 #include <linux/stat.h>
25 #include <linux/fcntl.h>
26 #include <linux/string.h>
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
30 #include <linux/sunrpc/clnt.h>
31 #include <linux/nfs_fs.h>
32 #include <linux/nfs_mount.h>
33 #include <linux/pagemap.h>
34 #include <linux/pagevec.h>
35 #include <linux/namei.h>
36 #include <linux/mount.h>
37 #include <linux/swap.h>
38 #include <linux/sched.h>
39 #include <linux/kmemleak.h>
40 #include <linux/xattr.h>
42 #include "delegation.h"
49 /* #define NFS_DEBUG_VERBOSE 1 */
51 static int nfs_opendir(struct inode *, struct file *);
52 static int nfs_closedir(struct inode *, struct file *);
53 static int nfs_readdir(struct file *, struct dir_context *);
54 static int nfs_fsync_dir(struct file *, loff_t, loff_t, int);
55 static loff_t nfs_llseek_dir(struct file *, loff_t, int);
56 static void nfs_readdir_clear_array(struct page*);
58 const struct file_operations nfs_dir_operations = {
59 .llseek = nfs_llseek_dir,
60 .read = generic_read_dir,
61 .iterate_shared = nfs_readdir,
63 .release = nfs_closedir,
64 .fsync = nfs_fsync_dir,
67 const struct address_space_operations nfs_dir_aops = {
68 .freepage = nfs_readdir_clear_array,
71 static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, const struct cred *cred)
73 struct nfs_inode *nfsi = NFS_I(dir);
74 struct nfs_open_dir_context *ctx;
75 ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
78 ctx->attr_gencount = nfsi->attr_gencount;
81 ctx->cred = get_cred(cred);
82 spin_lock(&dir->i_lock);
83 if (list_empty(&nfsi->open_files) &&
84 (nfsi->cache_validity & NFS_INO_DATA_INVAL_DEFER))
85 nfsi->cache_validity |= NFS_INO_INVALID_DATA |
87 list_add(&ctx->list, &nfsi->open_files);
88 spin_unlock(&dir->i_lock);
91 return ERR_PTR(-ENOMEM);
94 static void put_nfs_open_dir_context(struct inode *dir, struct nfs_open_dir_context *ctx)
96 spin_lock(&dir->i_lock);
98 spin_unlock(&dir->i_lock);
107 nfs_opendir(struct inode *inode, struct file *filp)
110 struct nfs_open_dir_context *ctx;
112 dfprintk(FILE, "NFS: open dir(%pD2)\n", filp);
114 nfs_inc_stats(inode, NFSIOS_VFSOPEN);
116 ctx = alloc_nfs_open_dir_context(inode, current_cred());
121 filp->private_data = ctx;
127 nfs_closedir(struct inode *inode, struct file *filp)
129 put_nfs_open_dir_context(file_inode(filp), filp->private_data);
133 struct nfs_cache_array_entry {
137 unsigned char d_type;
140 struct nfs_cache_array {
144 struct nfs_cache_array_entry array[];
150 struct dir_context *ctx;
151 unsigned long page_index;
154 loff_t current_index;
157 unsigned long dir_verifier;
158 unsigned long timestamp;
159 unsigned long gencount;
160 unsigned int cache_entry_index;
163 } nfs_readdir_descriptor_t;
166 void nfs_readdir_init_array(struct page *page)
168 struct nfs_cache_array *array;
170 array = kmap_atomic(page);
171 memset(array, 0, sizeof(struct nfs_cache_array));
172 array->eof_index = -1;
173 kunmap_atomic(array);
177 * we are freeing strings created by nfs_add_to_readdir_array()
180 void nfs_readdir_clear_array(struct page *page)
182 struct nfs_cache_array *array;
185 array = kmap_atomic(page);
186 for (i = 0; i < array->size; i++)
187 kfree(array->array[i].string.name);
189 kunmap_atomic(array);
193 * the caller is responsible for freeing qstr.name
194 * when called by nfs_readdir_add_to_array, the strings will be freed in
195 * nfs_clear_readdir_array()
198 int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
201 string->name = kmemdup_nul(name, len, GFP_KERNEL);
202 if (string->name == NULL)
205 * Avoid a kmemleak false positive. The pointer to the name is stored
206 * in a page cache page which kmemleak does not scan.
208 kmemleak_not_leak(string->name);
209 string->hash = full_name_hash(NULL, name, len);
214 int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
216 struct nfs_cache_array *array = kmap(page);
217 struct nfs_cache_array_entry *cache_entry;
220 cache_entry = &array->array[array->size];
222 /* Check that this entry lies within the page bounds */
224 if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)
227 cache_entry->cookie = entry->prev_cookie;
228 cache_entry->ino = entry->ino;
229 cache_entry->d_type = entry->d_type;
230 ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
233 array->last_cookie = entry->cookie;
236 array->eof_index = array->size;
243 int is_32bit_api(void)
246 return in_compat_syscall();
248 return (BITS_PER_LONG == 32);
253 bool nfs_readdir_use_cookie(const struct file *filp)
255 if ((filp->f_mode & FMODE_32BITHASH) ||
256 (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
262 int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
264 loff_t diff = desc->ctx->pos - desc->current_index;
269 if (diff >= array->size) {
270 if (array->eof_index >= 0)
275 index = (unsigned int)diff;
276 *desc->dir_cookie = array->array[index].cookie;
277 desc->cache_entry_index = index;
285 nfs_readdir_inode_mapping_valid(struct nfs_inode *nfsi)
287 if (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
290 return !test_bit(NFS_INO_INVALIDATING, &nfsi->flags);
294 int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
298 int status = -EAGAIN;
300 for (i = 0; i < array->size; i++) {
301 if (array->array[i].cookie == *desc->dir_cookie) {
302 struct nfs_inode *nfsi = NFS_I(file_inode(desc->file));
303 struct nfs_open_dir_context *ctx = desc->file->private_data;
305 new_pos = desc->current_index + i;
306 if (ctx->attr_gencount != nfsi->attr_gencount ||
307 !nfs_readdir_inode_mapping_valid(nfsi)) {
309 ctx->attr_gencount = nfsi->attr_gencount;
310 } else if (new_pos < desc->prev_index) {
312 && ctx->dup_cookie == *desc->dir_cookie) {
313 if (printk_ratelimit()) {
314 pr_notice("NFS: directory %pD2 contains a readdir loop."
315 "Please contact your server vendor. "
316 "The file: %.*s has duplicate cookie %llu\n",
317 desc->file, array->array[i].string.len,
318 array->array[i].string.name, *desc->dir_cookie);
323 ctx->dup_cookie = *desc->dir_cookie;
326 if (nfs_readdir_use_cookie(desc->file))
327 desc->ctx->pos = *desc->dir_cookie;
329 desc->ctx->pos = new_pos;
330 desc->prev_index = new_pos;
331 desc->cache_entry_index = i;
335 if (array->eof_index >= 0) {
336 status = -EBADCOOKIE;
337 if (*desc->dir_cookie == array->last_cookie)
345 int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
347 struct nfs_cache_array *array;
350 array = kmap(desc->page);
352 if (*desc->dir_cookie == 0)
353 status = nfs_readdir_search_for_pos(array, desc);
355 status = nfs_readdir_search_for_cookie(array, desc);
357 if (status == -EAGAIN) {
358 desc->last_cookie = array->last_cookie;
359 desc->current_index += array->size;
366 /* Fill a page with xdr information before transferring to the cache page */
368 int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
369 struct nfs_entry *entry, struct file *file, struct inode *inode)
371 struct nfs_open_dir_context *ctx = file->private_data;
372 const struct cred *cred = ctx->cred;
373 unsigned long timestamp, gencount;
378 gencount = nfs_inc_attr_generation_counter();
379 desc->dir_verifier = nfs_save_change_attribute(inode);
380 error = NFS_PROTO(inode)->readdir(file_dentry(file), cred, entry->cookie, pages,
381 NFS_SERVER(inode)->dtsize, desc->plus);
383 /* We requested READDIRPLUS, but the server doesn't grok it */
384 if (error == -ENOTSUPP && desc->plus) {
385 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
386 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
392 desc->timestamp = timestamp;
393 desc->gencount = gencount;
398 static int xdr_decode(nfs_readdir_descriptor_t *desc,
399 struct nfs_entry *entry, struct xdr_stream *xdr)
401 struct inode *inode = file_inode(desc->file);
404 error = NFS_PROTO(inode)->decode_dirent(xdr, entry, desc->plus);
407 entry->fattr->time_start = desc->timestamp;
408 entry->fattr->gencount = desc->gencount;
412 /* Match file and dirent using either filehandle or fileid
413 * Note: caller is responsible for checking the fsid
416 int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
419 struct nfs_inode *nfsi;
421 if (d_really_is_negative(dentry))
424 inode = d_inode(dentry);
425 if (is_bad_inode(inode) || NFS_STALE(inode))
429 if (entry->fattr->fileid != nfsi->fileid)
431 if (entry->fh->size && nfs_compare_fh(entry->fh, &nfsi->fh) != 0)
437 bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx)
439 if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
441 if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
449 * This function is called by the lookup and getattr code to request the
450 * use of readdirplus to accelerate any future lookups in the same
453 void nfs_advise_use_readdirplus(struct inode *dir)
455 struct nfs_inode *nfsi = NFS_I(dir);
457 if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) &&
458 !list_empty(&nfsi->open_files))
459 set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags);
463 * This function is mainly for use by nfs_getattr().
465 * If this is an 'ls -l', we want to force use of readdirplus.
466 * Do this by checking if there is an active file descriptor
467 * and calling nfs_advise_use_readdirplus, then forcing a
470 void nfs_force_use_readdirplus(struct inode *dir)
472 struct nfs_inode *nfsi = NFS_I(dir);
474 if (nfs_server_capable(dir, NFS_CAP_READDIRPLUS) &&
475 !list_empty(&nfsi->open_files)) {
476 set_bit(NFS_INO_ADVISE_RDPLUS, &nfsi->flags);
477 invalidate_mapping_pages(dir->i_mapping,
478 nfsi->page_index + 1, -1);
483 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry,
484 unsigned long dir_verifier)
486 struct qstr filename = QSTR_INIT(entry->name, entry->len);
487 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
488 struct dentry *dentry;
489 struct dentry *alias;
493 if (!(entry->fattr->valid & NFS_ATTR_FATTR_FILEID))
495 if (!(entry->fattr->valid & NFS_ATTR_FATTR_FSID))
497 if (filename.len == 0)
499 /* Validate that the name doesn't contain any illegal '\0' */
500 if (strnlen(filename.name, filename.len) != filename.len)
503 if (strnchr(filename.name, filename.len, '/'))
505 if (filename.name[0] == '.') {
506 if (filename.len == 1)
508 if (filename.len == 2 && filename.name[1] == '.')
511 filename.hash = full_name_hash(parent, filename.name, filename.len);
513 dentry = d_lookup(parent, &filename);
516 dentry = d_alloc_parallel(parent, &filename, &wq);
520 if (!d_in_lookup(dentry)) {
521 /* Is there a mountpoint here? If so, just exit */
522 if (!nfs_fsid_equal(&NFS_SB(dentry->d_sb)->fsid,
523 &entry->fattr->fsid))
525 if (nfs_same_file(dentry, entry)) {
526 if (!entry->fh->size)
528 nfs_set_verifier(dentry, dir_verifier);
529 status = nfs_refresh_inode(d_inode(dentry), entry->fattr);
531 nfs_setsecurity(d_inode(dentry), entry->fattr, entry->label);
534 d_invalidate(dentry);
540 if (!entry->fh->size) {
541 d_lookup_done(dentry);
545 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);
546 alias = d_splice_alias(inode, dentry);
547 d_lookup_done(dentry);
554 nfs_set_verifier(dentry, dir_verifier);
559 /* Perform conversion from xdr to cache array */
561 int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
562 struct page **xdr_pages, struct page *page, unsigned int buflen)
564 struct xdr_stream stream;
566 struct page *scratch;
567 struct nfs_cache_array *array;
568 unsigned int count = 0;
571 scratch = alloc_page(GFP_KERNEL);
578 xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
579 xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
583 entry->label->len = NFS4_MAXLABELLEN;
585 status = xdr_decode(desc, entry, &stream);
587 if (status == -EAGAIN)
595 nfs_prime_dcache(file_dentry(desc->file), entry,
598 status = nfs_readdir_add_to_array(entry, page);
601 } while (!entry->eof);
604 if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
606 array->eof_index = array->size;
616 void nfs_readdir_free_pages(struct page **pages, unsigned int npages)
619 for (i = 0; i < npages; i++)
624 * nfs_readdir_alloc_pages() will allocate pages that must be freed with a call
625 * to nfs_readdir_free_pages()
628 int nfs_readdir_alloc_pages(struct page **pages, unsigned int npages)
632 for (i = 0; i < npages; i++) {
633 struct page *page = alloc_page(GFP_KERNEL);
641 nfs_readdir_free_pages(pages, i);
646 int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
648 struct page *pages[NFS_MAX_READDIR_PAGES];
649 struct nfs_entry entry;
650 struct file *file = desc->file;
651 struct nfs_cache_array *array;
652 int status = -ENOMEM;
653 unsigned int array_size = ARRAY_SIZE(pages);
655 nfs_readdir_init_array(page);
657 entry.prev_cookie = 0;
658 entry.cookie = desc->last_cookie;
660 entry.fh = nfs_alloc_fhandle();
661 entry.fattr = nfs_alloc_fattr();
662 entry.server = NFS_SERVER(inode);
663 if (entry.fh == NULL || entry.fattr == NULL)
666 entry.label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
667 if (IS_ERR(entry.label)) {
668 status = PTR_ERR(entry.label);
674 status = nfs_readdir_alloc_pages(pages, array_size);
676 goto out_release_array;
679 status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
684 status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
686 if (status == -ENOSPC)
690 } while (array->eof_index < 0);
692 nfs_readdir_free_pages(pages, array_size);
695 nfs4_label_free(entry.label);
697 nfs_free_fattr(entry.fattr);
698 nfs_free_fhandle(entry.fh);
703 * Now we cache directories properly, by converting xdr information
704 * to an array that can be used for lookups later. This results in
705 * fewer cache pages, since we can store more information on each page.
706 * We only need to convert from xdr once so future lookups are much simpler
709 int nfs_readdir_filler(void *data, struct page* page)
711 nfs_readdir_descriptor_t *desc = data;
712 struct inode *inode = file_inode(desc->file);
715 ret = nfs_readdir_xdr_to_array(desc, page, inode);
718 SetPageUptodate(page);
720 if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
721 /* Should never happen */
722 nfs_zap_mapping(inode, inode->i_mapping);
727 nfs_readdir_clear_array(page);
733 void cache_page_release(nfs_readdir_descriptor_t *desc)
735 put_page(desc->page);
740 struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
742 return read_cache_page(desc->file->f_mapping, desc->page_index,
743 nfs_readdir_filler, desc);
747 * Returns 0 if desc->dir_cookie was found on page desc->page_index
748 * and locks the page to prevent removal from the page cache.
751 int find_and_lock_cache_page(nfs_readdir_descriptor_t *desc)
753 struct inode *inode = file_inode(desc->file);
754 struct nfs_inode *nfsi = NFS_I(inode);
757 desc->page = get_cache_page(desc);
758 if (IS_ERR(desc->page))
759 return PTR_ERR(desc->page);
760 res = lock_page_killable(desc->page);
764 if (desc->page->mapping != NULL) {
765 res = nfs_readdir_search_array(desc);
767 nfsi->page_index = desc->page_index;
771 unlock_page(desc->page);
773 cache_page_release(desc);
777 /* Search for desc->dir_cookie from the beginning of the page cache */
779 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
783 if (desc->page_index == 0) {
784 desc->current_index = 0;
785 desc->prev_index = 0;
786 desc->last_cookie = 0;
789 res = find_and_lock_cache_page(desc);
790 } while (res == -EAGAIN);
795 * Once we've found the start of the dirent within a page: fill 'er up...
798 int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
800 struct file *file = desc->file;
803 struct nfs_cache_array *array = NULL;
804 struct nfs_open_dir_context *ctx = file->private_data;
806 array = kmap(desc->page);
807 for (i = desc->cache_entry_index; i < array->size; i++) {
808 struct nfs_cache_array_entry *ent;
810 ent = &array->array[i];
811 if (!dir_emit(desc->ctx, ent->string.name, ent->string.len,
812 nfs_compat_user_ino64(ent->ino), ent->d_type)) {
816 if (i < (array->size-1))
817 *desc->dir_cookie = array->array[i+1].cookie;
819 *desc->dir_cookie = array->last_cookie;
820 if (nfs_readdir_use_cookie(file))
821 desc->ctx->pos = *desc->dir_cookie;
827 if (array->eof_index >= 0)
831 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
832 (unsigned long long)*desc->dir_cookie, res);
837 * If we cannot find a cookie in our cache, we suspect that this is
838 * because it points to a deleted file, so we ask the server to return
839 * whatever it thinks is the next entry. We then feed this to filldir.
840 * If all goes well, we should then be able to find our way round the
841 * cache on the next call to readdir_search_pagecache();
843 * NOTE: we cannot add the anonymous page to the pagecache because
844 * the data it contains might not be page aligned. Besides,
845 * we should already have a complete representation of the
846 * directory in the page cache by the time we get here.
849 int uncached_readdir(nfs_readdir_descriptor_t *desc)
851 struct page *page = NULL;
853 struct inode *inode = file_inode(desc->file);
854 struct nfs_open_dir_context *ctx = desc->file->private_data;
856 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
857 (unsigned long long)*desc->dir_cookie);
859 page = alloc_page(GFP_HIGHUSER);
865 desc->page_index = 0;
866 desc->last_cookie = *desc->dir_cookie;
870 status = nfs_readdir_xdr_to_array(desc, page, inode);
874 status = nfs_do_filldir(desc);
877 nfs_readdir_clear_array(desc->page);
878 cache_page_release(desc);
880 dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
885 /* The file offset position represents the dirent entry number. A
886 last cookie cache takes care of the common case of reading the
889 static int nfs_readdir(struct file *file, struct dir_context *ctx)
891 struct dentry *dentry = file_dentry(file);
892 struct inode *inode = d_inode(dentry);
893 struct nfs_open_dir_context *dir_ctx = file->private_data;
894 nfs_readdir_descriptor_t my_desc = {
897 .dir_cookie = &dir_ctx->dir_cookie,
898 .plus = nfs_use_readdirplus(inode, ctx),
903 dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
904 file, (long long)ctx->pos);
905 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
908 * ctx->pos points to the dirent entry number.
909 * *desc->dir_cookie has the cookie for the next entry. We have
910 * to either find the entry with the appropriate number or
911 * revalidate the cookie.
913 if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
914 res = nfs_revalidate_mapping(inode, file->f_mapping);
919 res = readdir_search_pagecache(desc);
921 if (res == -EBADCOOKIE) {
923 /* This means either end of directory */
924 if (*desc->dir_cookie && !desc->eof) {
925 /* Or that the server has 'lost' a cookie */
926 res = uncached_readdir(desc);
932 if (res == -ETOOSMALL && desc->plus) {
933 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
934 nfs_zap_caches(inode);
935 desc->page_index = 0;
943 res = nfs_do_filldir(desc);
944 unlock_page(desc->page);
945 cache_page_release(desc);
948 } while (!desc->eof);
952 dfprintk(FILE, "NFS: readdir(%pD2) returns %d\n", file, res);
956 static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
958 struct nfs_open_dir_context *dir_ctx = filp->private_data;
960 dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n",
961 filp, offset, whence);
969 spin_lock(&filp->f_lock);
974 spin_lock(&filp->f_lock);
975 offset += filp->f_pos;
977 spin_unlock(&filp->f_lock);
981 if (offset != filp->f_pos) {
982 filp->f_pos = offset;
983 if (nfs_readdir_use_cookie(filp))
984 dir_ctx->dir_cookie = offset;
986 dir_ctx->dir_cookie = 0;
989 spin_unlock(&filp->f_lock);
994 * All directory operations under NFS are synchronous, so fsync()
995 * is a dummy operation.
997 static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
1000 dfprintk(FILE, "NFS: fsync dir(%pD2) datasync %d\n", filp, datasync);
1002 nfs_inc_stats(file_inode(filp), NFSIOS_VFSFSYNC);
1007 * nfs_force_lookup_revalidate - Mark the directory as having changed
1008 * @dir: pointer to directory inode
1010 * This forces the revalidation code in nfs_lookup_revalidate() to do a
1011 * full lookup on all child dentries of 'dir' whenever a change occurs
1012 * on the server that might have invalidated our dcache.
1014 * Note that we reserve bit '0' as a tag to let us know when a dentry
1015 * was revalidated while holding a delegation on its inode.
1017 * The caller should be holding dir->i_lock
1019 void nfs_force_lookup_revalidate(struct inode *dir)
1021 NFS_I(dir)->cache_change_attribute += 2;
1023 EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
1026 * nfs_verify_change_attribute - Detects NFS remote directory changes
1027 * @dir: pointer to parent directory inode
1028 * @verf: previously saved change attribute
1030 * Return "false" if the verifiers doesn't match the change attribute.
1031 * This would usually indicate that the directory contents have changed on
1032 * the server, and that any dentries need revalidating.
1034 static bool nfs_verify_change_attribute(struct inode *dir, unsigned long verf)
1036 return (verf & ~1UL) == nfs_save_change_attribute(dir);
1039 static void nfs_set_verifier_delegated(unsigned long *verf)
1044 #if IS_ENABLED(CONFIG_NFS_V4)
1045 static void nfs_unset_verifier_delegated(unsigned long *verf)
1049 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
1051 static bool nfs_test_verifier_delegated(unsigned long verf)
1056 static bool nfs_verifier_is_delegated(struct dentry *dentry)
1058 return nfs_test_verifier_delegated(dentry->d_time);
1061 static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf)
1063 struct inode *inode = d_inode(dentry);
1064 struct inode *dir = d_inode(dentry->d_parent);
1066 if (!nfs_verify_change_attribute(dir, verf))
1068 if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
1069 nfs_set_verifier_delegated(&verf);
1070 dentry->d_time = verf;
1074 * nfs_set_verifier - save a parent directory verifier in the dentry
1075 * @dentry: pointer to dentry
1076 * @verf: verifier to save
1078 * Saves the parent directory verifier in @dentry. If the inode has
1079 * a delegation, we also tag the dentry as having been revalidated
1080 * while holding a delegation so that we know we don't have to
1081 * look it up again after a directory change.
1083 void nfs_set_verifier(struct dentry *dentry, unsigned long verf)
1086 spin_lock(&dentry->d_lock);
1087 nfs_set_verifier_locked(dentry, verf);
1088 spin_unlock(&dentry->d_lock);
1090 EXPORT_SYMBOL_GPL(nfs_set_verifier);
1092 #if IS_ENABLED(CONFIG_NFS_V4)
1094 * nfs_clear_verifier_delegated - clear the dir verifier delegation tag
1095 * @inode: pointer to inode
1097 * Iterates through the dentries in the inode alias list and clears
1098 * the tag used to indicate that the dentry has been revalidated
1099 * while holding a delegation.
1100 * This function is intended for use when the delegation is being
1101 * returned or revoked.
1103 void nfs_clear_verifier_delegated(struct inode *inode)
1105 struct dentry *alias;
1109 spin_lock(&inode->i_lock);
1110 hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
1111 spin_lock(&alias->d_lock);
1112 nfs_unset_verifier_delegated(&alias->d_time);
1113 spin_unlock(&alias->d_lock);
1115 spin_unlock(&inode->i_lock);
1117 EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated);
1118 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
1121 * A check for whether or not the parent directory has changed.
1122 * In the case it has, we assume that the dentries are untrustworthy
1123 * and may need to be looked up again.
1124 * If rcu_walk prevents us from performing a full check, return 0.
1126 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry,
1129 if (IS_ROOT(dentry))
1131 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
1133 if (!nfs_verify_change_attribute(dir, dentry->d_time))
1135 /* Revalidate nfsi->cache_change_attribute before we declare a match */
1136 if (nfs_mapping_need_revalidate_inode(dir)) {
1139 if (__nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
1142 if (!nfs_verify_change_attribute(dir, dentry->d_time))
1148 * Use intent information to check whether or not we're going to do
1149 * an O_EXCL create using this path component.
1151 static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags)
1153 if (NFS_PROTO(dir)->version == 2)
1155 return flags & LOOKUP_EXCL;
1159 * Inode and filehandle revalidation for lookups.
1161 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
1162 * or if the intent information indicates that we're about to open this
1163 * particular file and the "nocto" mount flag is not set.
1167 int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
1169 struct nfs_server *server = NFS_SERVER(inode);
1172 if (IS_AUTOMOUNT(inode))
1175 if (flags & LOOKUP_OPEN) {
1176 switch (inode->i_mode & S_IFMT) {
1178 /* A NFSv4 OPEN will revalidate later */
1179 if (server->caps & NFS_CAP_ATOMIC_OPEN)
1183 if (server->flags & NFS_MOUNT_NOCTO)
1185 /* NFS close-to-open cache consistency validation */
1190 /* VFS wants an on-the-wire revalidation */
1191 if (flags & LOOKUP_REVAL)
1194 return (inode->i_nlink == 0) ? -ESTALE : 0;
1196 if (flags & LOOKUP_RCU)
1198 ret = __nfs_revalidate_inode(server, inode);
1204 static void nfs_mark_dir_for_revalidate(struct inode *inode)
1206 struct nfs_inode *nfsi = NFS_I(inode);
1208 spin_lock(&inode->i_lock);
1209 nfsi->cache_validity |= NFS_INO_REVAL_PAGECACHE;
1210 spin_unlock(&inode->i_lock);
1214 * We judge how long we want to trust negative
1215 * dentries by looking at the parent inode mtime.
1217 * If parent mtime has changed, we revalidate, else we wait for a
1218 * period corresponding to the parent's attribute cache timeout value.
1220 * If LOOKUP_RCU prevents us from performing a full check, return 1
1221 * suggesting a reval is needed.
1223 * Note that when creating a new file, or looking up a rename target,
1224 * then it shouldn't be necessary to revalidate a negative dentry.
1227 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
1230 if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET))
1232 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
1234 return !nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU);
1238 nfs_lookup_revalidate_done(struct inode *dir, struct dentry *dentry,
1239 struct inode *inode, int error)
1243 dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is valid\n",
1248 * We can't d_drop the root of a disconnected tree:
1249 * its d_hash is on the s_anon list and d_drop() would hide
1250 * it from shrink_dcache_for_unmount(), leading to busy
1251 * inodes on unmount and further oopses.
1253 if (inode && IS_ROOT(dentry))
1255 dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) is invalid\n",
1259 dfprintk(LOOKUPCACHE, "NFS: %s(%pd2) lookup returned error %d\n",
1260 __func__, dentry, error);
1265 nfs_lookup_revalidate_negative(struct inode *dir, struct dentry *dentry,
1269 if (nfs_neg_need_reval(dir, dentry, flags)) {
1270 if (flags & LOOKUP_RCU)
1274 return nfs_lookup_revalidate_done(dir, dentry, NULL, ret);
1278 nfs_lookup_revalidate_delegated(struct inode *dir, struct dentry *dentry,
1279 struct inode *inode)
1281 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1282 return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
1286 nfs_lookup_revalidate_dentry(struct inode *dir, struct dentry *dentry,
1287 struct inode *inode)
1289 struct nfs_fh *fhandle;
1290 struct nfs_fattr *fattr;
1291 struct nfs4_label *label;
1292 unsigned long dir_verifier;
1296 fhandle = nfs_alloc_fhandle();
1297 fattr = nfs_alloc_fattr();
1298 label = nfs4_label_alloc(NFS_SERVER(inode), GFP_KERNEL);
1299 if (fhandle == NULL || fattr == NULL || IS_ERR(label))
1302 dir_verifier = nfs_save_change_attribute(dir);
1303 ret = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label);
1311 if (NFS_SERVER(inode)->flags & NFS_MOUNT_SOFTREVAL)
1317 if (nfs_compare_fh(NFS_FH(inode), fhandle))
1319 if (nfs_refresh_inode(inode, fattr) < 0)
1322 nfs_setsecurity(inode, fattr, label);
1323 nfs_set_verifier(dentry, dir_verifier);
1325 /* set a readdirplus hint that we had a cache miss */
1326 nfs_force_use_readdirplus(dir);
1329 nfs_free_fattr(fattr);
1330 nfs_free_fhandle(fhandle);
1331 nfs4_label_free(label);
1334 * If the lookup failed despite the dentry change attribute being
1335 * a match, then we should revalidate the directory cache.
1337 if (!ret && nfs_verify_change_attribute(dir, dentry->d_time))
1338 nfs_mark_dir_for_revalidate(dir);
1339 return nfs_lookup_revalidate_done(dir, dentry, inode, ret);
1343 * This is called every time the dcache has a lookup hit,
1344 * and we should check whether we can really trust that
1347 * NOTE! The hit can be a negative hit too, don't assume
1350 * If the parent directory is seen to have changed, we throw out the
1351 * cached dentry and do a new lookup.
1354 nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
1357 struct inode *inode;
1360 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
1361 inode = d_inode(dentry);
1364 return nfs_lookup_revalidate_negative(dir, dentry, flags);
1366 if (is_bad_inode(inode)) {
1367 dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
1372 if (nfs_verifier_is_delegated(dentry))
1373 return nfs_lookup_revalidate_delegated(dir, dentry, inode);
1375 /* Force a full look up iff the parent directory has changed */
1376 if (!(flags & (LOOKUP_EXCL | LOOKUP_REVAL)) &&
1377 nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU)) {
1378 error = nfs_lookup_verify_inode(inode, flags);
1380 if (error == -ESTALE)
1381 nfs_mark_dir_for_revalidate(dir);
1384 nfs_advise_use_readdirplus(dir);
1388 if (flags & LOOKUP_RCU)
1391 if (NFS_STALE(inode))
1394 trace_nfs_lookup_revalidate_enter(dir, dentry, flags);
1395 error = nfs_lookup_revalidate_dentry(dir, dentry, inode);
1396 trace_nfs_lookup_revalidate_exit(dir, dentry, flags, error);
1399 return nfs_lookup_revalidate_done(dir, dentry, inode, 1);
1401 if (flags & LOOKUP_RCU)
1403 return nfs_lookup_revalidate_done(dir, dentry, inode, 0);
1407 __nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags,
1408 int (*reval)(struct inode *, struct dentry *, unsigned int))
1410 struct dentry *parent;
1414 if (flags & LOOKUP_RCU) {
1415 parent = READ_ONCE(dentry->d_parent);
1416 dir = d_inode_rcu(parent);
1419 ret = reval(dir, dentry, flags);
1420 if (parent != READ_ONCE(dentry->d_parent))
1423 parent = dget_parent(dentry);
1424 ret = reval(d_inode(parent), dentry, flags);
1430 static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
1432 return __nfs_lookup_revalidate(dentry, flags, nfs_do_lookup_revalidate);
1436 * A weaker form of d_revalidate for revalidating just the d_inode(dentry)
1437 * when we don't really care about the dentry name. This is called when a
1438 * pathwalk ends on a dentry that was not found via a normal lookup in the
1439 * parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals).
1441 * In this situation, we just want to verify that the inode itself is OK
1442 * since the dentry might have changed on the server.
1444 static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
1446 struct inode *inode = d_inode(dentry);
1450 * I believe we can only get a negative dentry here in the case of a
1451 * procfs-style symlink. Just assume it's correct for now, but we may
1452 * eventually need to do something more here.
1455 dfprintk(LOOKUPCACHE, "%s: %pd2 has negative inode\n",
1460 if (is_bad_inode(inode)) {
1461 dfprintk(LOOKUPCACHE, "%s: %pd2 has dud inode\n",
1466 error = nfs_lookup_verify_inode(inode, flags);
1467 dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
1468 __func__, inode->i_ino, error ? "invalid" : "valid");
1473 * This is called from dput() when d_count is going to 0.
1475 static int nfs_dentry_delete(const struct dentry *dentry)
1477 dfprintk(VFS, "NFS: dentry_delete(%pd2, %x)\n",
1478 dentry, dentry->d_flags);
1480 /* Unhash any dentry with a stale inode */
1481 if (d_really_is_positive(dentry) && NFS_STALE(d_inode(dentry)))
1484 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1485 /* Unhash it, so that ->d_iput() would be called */
1488 if (!(dentry->d_sb->s_flags & SB_ACTIVE)) {
1489 /* Unhash it, so that ancestors of killed async unlink
1490 * files will be cleaned up during umount */
1497 /* Ensure that we revalidate inode->i_nlink */
1498 static void nfs_drop_nlink(struct inode *inode)
1500 spin_lock(&inode->i_lock);
1501 /* drop the inode if we're reasonably sure this is the last link */
1502 if (inode->i_nlink > 0)
1504 NFS_I(inode)->attr_gencount = nfs_inc_attr_generation_counter();
1505 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_CHANGE
1506 | NFS_INO_INVALID_CTIME
1507 | NFS_INO_INVALID_OTHER
1508 | NFS_INO_REVAL_FORCED;
1509 spin_unlock(&inode->i_lock);
1513 * Called when the dentry loses inode.
1514 * We use it to clean up silly-renamed files.
1516 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
1518 if (S_ISDIR(inode->i_mode))
1519 /* drop any readdir cache as it could easily be old */
1520 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
1522 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1523 nfs_complete_unlink(dentry, inode);
1524 nfs_drop_nlink(inode);
1529 static void nfs_d_release(struct dentry *dentry)
1531 /* free cached devname value, if it survived that far */
1532 if (unlikely(dentry->d_fsdata)) {
1533 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1536 kfree(dentry->d_fsdata);
1540 const struct dentry_operations nfs_dentry_operations = {
1541 .d_revalidate = nfs_lookup_revalidate,
1542 .d_weak_revalidate = nfs_weak_revalidate,
1543 .d_delete = nfs_dentry_delete,
1544 .d_iput = nfs_dentry_iput,
1545 .d_automount = nfs_d_automount,
1546 .d_release = nfs_d_release,
1548 EXPORT_SYMBOL_GPL(nfs_dentry_operations);
1550 struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
1553 struct inode *inode = NULL;
1554 struct nfs_fh *fhandle = NULL;
1555 struct nfs_fattr *fattr = NULL;
1556 struct nfs4_label *label = NULL;
1557 unsigned long dir_verifier;
1560 dfprintk(VFS, "NFS: lookup(%pd2)\n", dentry);
1561 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
1563 if (unlikely(dentry->d_name.len > NFS_SERVER(dir)->namelen))
1564 return ERR_PTR(-ENAMETOOLONG);
1567 * If we're doing an exclusive create, optimize away the lookup
1568 * but don't hash the dentry.
1570 if (nfs_is_exclusive_create(dir, flags) || flags & LOOKUP_RENAME_TARGET)
1573 res = ERR_PTR(-ENOMEM);
1574 fhandle = nfs_alloc_fhandle();
1575 fattr = nfs_alloc_fattr();
1576 if (fhandle == NULL || fattr == NULL)
1579 label = nfs4_label_alloc(NFS_SERVER(dir), GFP_NOWAIT);
1583 dir_verifier = nfs_save_change_attribute(dir);
1584 trace_nfs_lookup_enter(dir, dentry, flags);
1585 error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, label);
1586 if (error == -ENOENT)
1589 res = ERR_PTR(error);
1592 inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
1593 res = ERR_CAST(inode);
1597 /* Notify readdir to use READDIRPLUS */
1598 nfs_force_use_readdirplus(dir);
1601 res = d_splice_alias(inode, dentry);
1607 nfs_set_verifier(dentry, dir_verifier);
1609 trace_nfs_lookup_exit(dir, dentry, flags, error);
1610 nfs4_label_free(label);
1612 nfs_free_fattr(fattr);
1613 nfs_free_fhandle(fhandle);
1616 EXPORT_SYMBOL_GPL(nfs_lookup);
1618 #if IS_ENABLED(CONFIG_NFS_V4)
1619 static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
1621 const struct dentry_operations nfs4_dentry_operations = {
1622 .d_revalidate = nfs4_lookup_revalidate,
1623 .d_weak_revalidate = nfs_weak_revalidate,
1624 .d_delete = nfs_dentry_delete,
1625 .d_iput = nfs_dentry_iput,
1626 .d_automount = nfs_d_automount,
1627 .d_release = nfs_d_release,
1629 EXPORT_SYMBOL_GPL(nfs4_dentry_operations);
1631 static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags, struct file *filp)
1633 return alloc_nfs_open_context(dentry, flags_to_mode(open_flags), filp);
1636 static int do_open(struct inode *inode, struct file *filp)
1638 nfs_fscache_open_file(inode, filp);
1642 static int nfs_finish_open(struct nfs_open_context *ctx,
1643 struct dentry *dentry,
1644 struct file *file, unsigned open_flags)
1648 err = finish_open(file, dentry, do_open);
1651 if (S_ISREG(file->f_path.dentry->d_inode->i_mode))
1652 nfs_file_set_open_context(file, ctx);
1659 int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
1660 struct file *file, unsigned open_flags,
1663 DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
1664 struct nfs_open_context *ctx;
1666 struct iattr attr = { .ia_valid = ATTR_OPEN };
1667 struct inode *inode;
1668 unsigned int lookup_flags = 0;
1669 bool switched = false;
1673 /* Expect a negative dentry */
1674 BUG_ON(d_inode(dentry));
1676 dfprintk(VFS, "NFS: atomic_open(%s/%lu), %pd\n",
1677 dir->i_sb->s_id, dir->i_ino, dentry);
1679 err = nfs_check_flags(open_flags);
1683 /* NFS only supports OPEN on regular files */
1684 if ((open_flags & O_DIRECTORY)) {
1685 if (!d_in_lookup(dentry)) {
1687 * Hashed negative dentry with O_DIRECTORY: dentry was
1688 * revalidated and is fine, no need to perform lookup
1693 lookup_flags = LOOKUP_OPEN|LOOKUP_DIRECTORY;
1697 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
1698 return -ENAMETOOLONG;
1700 if (open_flags & O_CREAT) {
1701 struct nfs_server *server = NFS_SERVER(dir);
1703 if (!(server->attr_bitmask[2] & FATTR4_WORD2_MODE_UMASK))
1704 mode &= ~current_umask();
1706 attr.ia_valid |= ATTR_MODE;
1707 attr.ia_mode = mode;
1709 if (open_flags & O_TRUNC) {
1710 attr.ia_valid |= ATTR_SIZE;
1714 if (!(open_flags & O_CREAT) && !d_in_lookup(dentry)) {
1717 dentry = d_alloc_parallel(dentry->d_parent,
1718 &dentry->d_name, &wq);
1720 return PTR_ERR(dentry);
1721 if (unlikely(!d_in_lookup(dentry)))
1722 return finish_no_open(file, dentry);
1725 ctx = create_nfs_open_context(dentry, open_flags, file);
1730 trace_nfs_atomic_open_enter(dir, ctx, open_flags);
1731 inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr, &created);
1733 file->f_mode |= FMODE_CREATED;
1734 if (IS_ERR(inode)) {
1735 err = PTR_ERR(inode);
1736 trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
1737 put_nfs_open_context(ctx);
1741 d_splice_alias(NULL, dentry);
1742 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1748 if (!(open_flags & O_NOFOLLOW))
1758 err = nfs_finish_open(ctx, ctx->dentry, file, open_flags);
1759 trace_nfs_atomic_open_exit(dir, ctx, open_flags, err);
1760 put_nfs_open_context(ctx);
1762 if (unlikely(switched)) {
1763 d_lookup_done(dentry);
1769 res = nfs_lookup(dir, dentry, lookup_flags);
1771 inode = d_inode(dentry);
1772 if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
1773 !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)))
1774 res = ERR_PTR(-ENOTDIR);
1775 else if (inode && S_ISREG(inode->i_mode))
1776 res = ERR_PTR(-EOPENSTALE);
1777 } else if (!IS_ERR(res)) {
1778 inode = d_inode(res);
1779 if ((lookup_flags & LOOKUP_DIRECTORY) && inode &&
1780 !(S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) {
1782 res = ERR_PTR(-ENOTDIR);
1783 } else if (inode && S_ISREG(inode->i_mode)) {
1785 res = ERR_PTR(-EOPENSTALE);
1789 d_lookup_done(dentry);
1796 return PTR_ERR(res);
1797 return finish_no_open(file, res);
1799 EXPORT_SYMBOL_GPL(nfs_atomic_open);
1802 nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry,
1805 struct inode *inode;
1807 if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
1809 if (d_mountpoint(dentry))
1812 inode = d_inode(dentry);
1814 /* We can't create new files in nfs_open_revalidate(), so we
1815 * optimize away revalidation of negative dentries.
1820 if (nfs_verifier_is_delegated(dentry))
1821 return nfs_lookup_revalidate_delegated(dir, dentry, inode);
1823 /* NFS only supports OPEN on regular files */
1824 if (!S_ISREG(inode->i_mode))
1827 /* We cannot do exclusive creation on a positive dentry */
1828 if (flags & (LOOKUP_EXCL | LOOKUP_REVAL))
1831 /* Check if the directory changed */
1832 if (!nfs_check_verifier(dir, dentry, flags & LOOKUP_RCU))
1835 /* Let f_op->open() actually open (and revalidate) the file */
1838 if (flags & LOOKUP_RCU)
1840 return nfs_lookup_revalidate_dentry(dir, dentry, inode);
1843 return nfs_do_lookup_revalidate(dir, dentry, flags);
1846 static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
1848 return __nfs_lookup_revalidate(dentry, flags,
1849 nfs4_do_lookup_revalidate);
1852 #endif /* CONFIG_NFSV4 */
1855 nfs_add_or_obtain(struct dentry *dentry, struct nfs_fh *fhandle,
1856 struct nfs_fattr *fattr,
1857 struct nfs4_label *label)
1859 struct dentry *parent = dget_parent(dentry);
1860 struct inode *dir = d_inode(parent);
1861 struct inode *inode;
1867 if (fhandle->size == 0) {
1868 error = NFS_PROTO(dir)->lookup(dir, dentry, fhandle, fattr, NULL);
1872 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1873 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1874 struct nfs_server *server = NFS_SB(dentry->d_sb);
1875 error = server->nfs_client->rpc_ops->getattr(server, fhandle,
1880 inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
1881 d = d_splice_alias(inode, dentry);
1889 EXPORT_SYMBOL_GPL(nfs_add_or_obtain);
1892 * Code common to create, mkdir, and mknod.
1894 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1895 struct nfs_fattr *fattr,
1896 struct nfs4_label *label)
1900 d = nfs_add_or_obtain(dentry, fhandle, fattr, label);
1904 /* Callers don't care */
1908 EXPORT_SYMBOL_GPL(nfs_instantiate);
1911 * Following a failed create operation, we drop the dentry rather
1912 * than retain a negative dentry. This avoids a problem in the event
1913 * that the operation succeeded on the server, but an error in the
1914 * reply path made it appear to have failed.
1916 int nfs_create(struct inode *dir, struct dentry *dentry,
1917 umode_t mode, bool excl)
1920 int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT;
1923 dfprintk(VFS, "NFS: create(%s/%lu), %pd\n",
1924 dir->i_sb->s_id, dir->i_ino, dentry);
1926 attr.ia_mode = mode;
1927 attr.ia_valid = ATTR_MODE;
1929 trace_nfs_create_enter(dir, dentry, open_flags);
1930 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
1931 trace_nfs_create_exit(dir, dentry, open_flags, error);
1939 EXPORT_SYMBOL_GPL(nfs_create);
1942 * See comments for nfs_proc_create regarding failed operations.
1945 nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1950 dfprintk(VFS, "NFS: mknod(%s/%lu), %pd\n",
1951 dir->i_sb->s_id, dir->i_ino, dentry);
1953 attr.ia_mode = mode;
1954 attr.ia_valid = ATTR_MODE;
1956 trace_nfs_mknod_enter(dir, dentry);
1957 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
1958 trace_nfs_mknod_exit(dir, dentry, status);
1966 EXPORT_SYMBOL_GPL(nfs_mknod);
1969 * See comments for nfs_proc_create regarding failed operations.
1971 int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
1976 dfprintk(VFS, "NFS: mkdir(%s/%lu), %pd\n",
1977 dir->i_sb->s_id, dir->i_ino, dentry);
1979 attr.ia_valid = ATTR_MODE;
1980 attr.ia_mode = mode | S_IFDIR;
1982 trace_nfs_mkdir_enter(dir, dentry);
1983 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
1984 trace_nfs_mkdir_exit(dir, dentry, error);
1992 EXPORT_SYMBOL_GPL(nfs_mkdir);
1994 static void nfs_dentry_handle_enoent(struct dentry *dentry)
1996 if (simple_positive(dentry))
2000 int nfs_rmdir(struct inode *dir, struct dentry *dentry)
2004 dfprintk(VFS, "NFS: rmdir(%s/%lu), %pd\n",
2005 dir->i_sb->s_id, dir->i_ino, dentry);
2007 trace_nfs_rmdir_enter(dir, dentry);
2008 if (d_really_is_positive(dentry)) {
2009 down_write(&NFS_I(d_inode(dentry))->rmdir_sem);
2010 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
2011 /* Ensure the VFS deletes this inode */
2014 clear_nlink(d_inode(dentry));
2017 nfs_dentry_handle_enoent(dentry);
2019 up_write(&NFS_I(d_inode(dentry))->rmdir_sem);
2021 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
2022 trace_nfs_rmdir_exit(dir, dentry, error);
2026 EXPORT_SYMBOL_GPL(nfs_rmdir);
2029 * Remove a file after making sure there are no pending writes,
2030 * and after checking that the file has only one user.
2032 * We invalidate the attribute cache and free the inode prior to the operation
2033 * to avoid possible races if the server reuses the inode.
2035 static int nfs_safe_remove(struct dentry *dentry)
2037 struct inode *dir = d_inode(dentry->d_parent);
2038 struct inode *inode = d_inode(dentry);
2041 dfprintk(VFS, "NFS: safe_remove(%pd2)\n", dentry);
2043 /* If the dentry was sillyrenamed, we simply call d_delete() */
2044 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
2049 trace_nfs_remove_enter(dir, dentry);
2050 if (inode != NULL) {
2051 error = NFS_PROTO(dir)->remove(dir, dentry);
2053 nfs_drop_nlink(inode);
2055 error = NFS_PROTO(dir)->remove(dir, dentry);
2056 if (error == -ENOENT)
2057 nfs_dentry_handle_enoent(dentry);
2058 trace_nfs_remove_exit(dir, dentry, error);
2063 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode
2064 * belongs to an active ".nfs..." file and we return -EBUSY.
2066 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
2068 int nfs_unlink(struct inode *dir, struct dentry *dentry)
2071 int need_rehash = 0;
2073 dfprintk(VFS, "NFS: unlink(%s/%lu, %pd)\n", dir->i_sb->s_id,
2074 dir->i_ino, dentry);
2076 trace_nfs_unlink_enter(dir, dentry);
2077 spin_lock(&dentry->d_lock);
2078 if (d_count(dentry) > 1) {
2079 spin_unlock(&dentry->d_lock);
2080 /* Start asynchronous writeout of the inode */
2081 write_inode_now(d_inode(dentry), 0);
2082 error = nfs_sillyrename(dir, dentry);
2085 if (!d_unhashed(dentry)) {
2089 spin_unlock(&dentry->d_lock);
2090 error = nfs_safe_remove(dentry);
2091 if (!error || error == -ENOENT) {
2092 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
2093 } else if (need_rehash)
2096 trace_nfs_unlink_exit(dir, dentry, error);
2099 EXPORT_SYMBOL_GPL(nfs_unlink);
2102 * To create a symbolic link, most file systems instantiate a new inode,
2103 * add a page to it containing the path, then write it out to the disk
2104 * using prepare_write/commit_write.
2106 * Unfortunately the NFS client can't create the in-core inode first
2107 * because it needs a file handle to create an in-core inode (see
2108 * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the
2109 * symlink request has completed on the server.
2111 * So instead we allocate a raw page, copy the symname into it, then do
2112 * the SYMLINK request with the page as the buffer. If it succeeds, we
2113 * now have a new file handle and can instantiate an in-core NFS inode
2114 * and move the raw page into its mapping.
2116 int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
2121 unsigned int pathlen = strlen(symname);
2124 dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s)\n", dir->i_sb->s_id,
2125 dir->i_ino, dentry, symname);
2127 if (pathlen > PAGE_SIZE)
2128 return -ENAMETOOLONG;
2130 attr.ia_mode = S_IFLNK | S_IRWXUGO;
2131 attr.ia_valid = ATTR_MODE;
2133 page = alloc_page(GFP_USER);
2137 kaddr = page_address(page);
2138 memcpy(kaddr, symname, pathlen);
2139 if (pathlen < PAGE_SIZE)
2140 memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
2142 trace_nfs_symlink_enter(dir, dentry);
2143 error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
2144 trace_nfs_symlink_exit(dir, dentry, error);
2146 dfprintk(VFS, "NFS: symlink(%s/%lu, %pd, %s) error %d\n",
2147 dir->i_sb->s_id, dir->i_ino,
2148 dentry, symname, error);
2155 * No big deal if we can't add this page to the page cache here.
2156 * READLINK will get the missing page from the server if needed.
2158 if (!add_to_page_cache_lru(page, d_inode(dentry)->i_mapping, 0,
2160 SetPageUptodate(page);
2163 * add_to_page_cache_lru() grabs an extra page refcount.
2164 * Drop it here to avoid leaking this page later.
2172 EXPORT_SYMBOL_GPL(nfs_symlink);
2175 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
2177 struct inode *inode = d_inode(old_dentry);
2180 dfprintk(VFS, "NFS: link(%pd2 -> %pd2)\n",
2181 old_dentry, dentry);
2183 trace_nfs_link_enter(inode, dir, dentry);
2185 if (S_ISREG(inode->i_mode))
2186 nfs_sync_inode(inode);
2187 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
2190 d_add(dentry, inode);
2192 trace_nfs_link_exit(inode, dir, dentry, error);
2195 EXPORT_SYMBOL_GPL(nfs_link);
2199 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
2200 * different file handle for the same inode after a rename (e.g. when
2201 * moving to a different directory). A fail-safe method to do so would
2202 * be to look up old_dir/old_name, create a link to new_dir/new_name and
2203 * rename the old file using the sillyrename stuff. This way, the original
2204 * file in old_dir will go away when the last process iput()s the inode.
2208 * It actually works quite well. One needs to have the possibility for
2209 * at least one ".nfs..." file in each directory the file ever gets
2210 * moved or linked to which happens automagically with the new
2211 * implementation that only depends on the dcache stuff instead of
2212 * using the inode layer
2214 * Unfortunately, things are a little more complicated than indicated
2215 * above. For a cross-directory move, we want to make sure we can get
2216 * rid of the old inode after the operation. This means there must be
2217 * no pending writes (if it's a file), and the use count must be 1.
2218 * If these conditions are met, we can drop the dentries before doing
2221 int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
2222 struct inode *new_dir, struct dentry *new_dentry,
2225 struct inode *old_inode = d_inode(old_dentry);
2226 struct inode *new_inode = d_inode(new_dentry);
2227 struct dentry *dentry = NULL, *rehash = NULL;
2228 struct rpc_task *task;
2234 dfprintk(VFS, "NFS: rename(%pd2 -> %pd2, ct=%d)\n",
2235 old_dentry, new_dentry,
2236 d_count(new_dentry));
2238 trace_nfs_rename_enter(old_dir, old_dentry, new_dir, new_dentry);
2240 * For non-directories, check whether the target is busy and if so,
2241 * make a copy of the dentry and then do a silly-rename. If the
2242 * silly-rename succeeds, the copied dentry is hashed and becomes
2245 if (new_inode && !S_ISDIR(new_inode->i_mode)) {
2247 * To prevent any new references to the target during the
2248 * rename, we unhash the dentry in advance.
2250 if (!d_unhashed(new_dentry)) {
2252 rehash = new_dentry;
2255 if (d_count(new_dentry) > 2) {
2258 /* copy the target dentry's name */
2259 dentry = d_alloc(new_dentry->d_parent,
2260 &new_dentry->d_name);
2264 /* silly-rename the existing target ... */
2265 err = nfs_sillyrename(new_dir, new_dentry);
2269 new_dentry = dentry;
2275 if (S_ISREG(old_inode->i_mode))
2276 nfs_sync_inode(old_inode);
2277 task = nfs_async_rename(old_dir, new_dir, old_dentry, new_dentry, NULL);
2279 error = PTR_ERR(task);
2283 error = rpc_wait_for_completion_task(task);
2285 ((struct nfs_renamedata *)task->tk_calldata)->cancelled = 1;
2286 /* Paired with the atomic_dec_and_test() barrier in rpc_do_put_task() */
2289 error = task->tk_status;
2291 /* Ensure the inode attributes are revalidated */
2293 spin_lock(&old_inode->i_lock);
2294 NFS_I(old_inode)->attr_gencount = nfs_inc_attr_generation_counter();
2295 NFS_I(old_inode)->cache_validity |= NFS_INO_INVALID_CHANGE
2296 | NFS_INO_INVALID_CTIME
2297 | NFS_INO_REVAL_FORCED;
2298 spin_unlock(&old_inode->i_lock);
2303 trace_nfs_rename_exit(old_dir, old_dentry,
2304 new_dir, new_dentry, error);
2306 if (new_inode != NULL)
2307 nfs_drop_nlink(new_inode);
2309 * The d_move() should be here instead of in an async RPC completion
2310 * handler because we need the proper locks to move the dentry. If
2311 * we're interrupted by a signal, the async RPC completion handler
2312 * should mark the directories for revalidation.
2314 d_move(old_dentry, new_dentry);
2315 nfs_set_verifier(old_dentry,
2316 nfs_save_change_attribute(new_dir));
2317 } else if (error == -ENOENT)
2318 nfs_dentry_handle_enoent(old_dentry);
2320 /* new dentry created? */
2325 EXPORT_SYMBOL_GPL(nfs_rename);
2327 static DEFINE_SPINLOCK(nfs_access_lru_lock);
2328 static LIST_HEAD(nfs_access_lru_list);
2329 static atomic_long_t nfs_access_nr_entries;
2331 static unsigned long nfs_access_max_cachesize = 4*1024*1024;
2332 module_param(nfs_access_max_cachesize, ulong, 0644);
2333 MODULE_PARM_DESC(nfs_access_max_cachesize, "NFS access maximum total cache length");
2335 static void nfs_access_free_entry(struct nfs_access_entry *entry)
2337 put_cred(entry->cred);
2338 kfree_rcu(entry, rcu_head);
2339 smp_mb__before_atomic();
2340 atomic_long_dec(&nfs_access_nr_entries);
2341 smp_mb__after_atomic();
2344 static void nfs_access_free_list(struct list_head *head)
2346 struct nfs_access_entry *cache;
2348 while (!list_empty(head)) {
2349 cache = list_entry(head->next, struct nfs_access_entry, lru);
2350 list_del(&cache->lru);
2351 nfs_access_free_entry(cache);
2355 static unsigned long
2356 nfs_do_access_cache_scan(unsigned int nr_to_scan)
2359 struct nfs_inode *nfsi, *next;
2360 struct nfs_access_entry *cache;
2363 spin_lock(&nfs_access_lru_lock);
2364 list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
2365 struct inode *inode;
2367 if (nr_to_scan-- == 0)
2369 inode = &nfsi->vfs_inode;
2370 spin_lock(&inode->i_lock);
2371 if (list_empty(&nfsi->access_cache_entry_lru))
2372 goto remove_lru_entry;
2373 cache = list_entry(nfsi->access_cache_entry_lru.next,
2374 struct nfs_access_entry, lru);
2375 list_move(&cache->lru, &head);
2376 rb_erase(&cache->rb_node, &nfsi->access_cache);
2378 if (!list_empty(&nfsi->access_cache_entry_lru))
2379 list_move_tail(&nfsi->access_cache_inode_lru,
2380 &nfs_access_lru_list);
2383 list_del_init(&nfsi->access_cache_inode_lru);
2384 smp_mb__before_atomic();
2385 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
2386 smp_mb__after_atomic();
2388 spin_unlock(&inode->i_lock);
2390 spin_unlock(&nfs_access_lru_lock);
2391 nfs_access_free_list(&head);
2396 nfs_access_cache_scan(struct shrinker *shrink, struct shrink_control *sc)
2398 int nr_to_scan = sc->nr_to_scan;
2399 gfp_t gfp_mask = sc->gfp_mask;
2401 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
2403 return nfs_do_access_cache_scan(nr_to_scan);
2408 nfs_access_cache_count(struct shrinker *shrink, struct shrink_control *sc)
2410 return vfs_pressure_ratio(atomic_long_read(&nfs_access_nr_entries));
2414 nfs_access_cache_enforce_limit(void)
2416 long nr_entries = atomic_long_read(&nfs_access_nr_entries);
2418 unsigned int nr_to_scan;
2420 if (nr_entries < 0 || nr_entries <= nfs_access_max_cachesize)
2423 diff = nr_entries - nfs_access_max_cachesize;
2424 if (diff < nr_to_scan)
2426 nfs_do_access_cache_scan(nr_to_scan);
2429 static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
2431 struct rb_root *root_node = &nfsi->access_cache;
2433 struct nfs_access_entry *entry;
2435 /* Unhook entries from the cache */
2436 while ((n = rb_first(root_node)) != NULL) {
2437 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2438 rb_erase(n, root_node);
2439 list_move(&entry->lru, head);
2441 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
2444 void nfs_access_zap_cache(struct inode *inode)
2448 if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
2450 /* Remove from global LRU init */
2451 spin_lock(&nfs_access_lru_lock);
2452 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2453 list_del_init(&NFS_I(inode)->access_cache_inode_lru);
2455 spin_lock(&inode->i_lock);
2456 __nfs_access_zap_cache(NFS_I(inode), &head);
2457 spin_unlock(&inode->i_lock);
2458 spin_unlock(&nfs_access_lru_lock);
2459 nfs_access_free_list(&head);
2461 EXPORT_SYMBOL_GPL(nfs_access_zap_cache);
2463 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, const struct cred *cred)
2465 struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
2468 struct nfs_access_entry *entry =
2469 rb_entry(n, struct nfs_access_entry, rb_node);
2470 int cmp = cred_fscmp(cred, entry->cred);
2482 static int nfs_access_get_cached_locked(struct inode *inode, const struct cred *cred, u32 *mask, bool may_block)
2484 struct nfs_inode *nfsi = NFS_I(inode);
2485 struct nfs_access_entry *cache;
2489 spin_lock(&inode->i_lock);
2491 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
2493 cache = nfs_access_search_rbtree(inode, cred);
2497 /* Found an entry, is our attribute cache valid? */
2498 if (!nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
2505 spin_unlock(&inode->i_lock);
2506 err = __nfs_revalidate_inode(NFS_SERVER(inode), inode);
2509 spin_lock(&inode->i_lock);
2512 *mask = cache->mask;
2513 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2516 spin_unlock(&inode->i_lock);
2519 spin_unlock(&inode->i_lock);
2520 nfs_access_zap_cache(inode);
2524 static int nfs_access_get_cached_rcu(struct inode *inode, const struct cred *cred, u32 *mask)
2526 /* Only check the most recently returned cache entry,
2527 * but do it without locking.
2529 struct nfs_inode *nfsi = NFS_I(inode);
2530 struct nfs_access_entry *cache;
2532 struct list_head *lh;
2535 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
2537 lh = rcu_dereference(list_tail_rcu(&nfsi->access_cache_entry_lru));
2538 cache = list_entry(lh, struct nfs_access_entry, lru);
2539 if (lh == &nfsi->access_cache_entry_lru ||
2540 cred_fscmp(cred, cache->cred) != 0)
2544 if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_ACCESS))
2546 *mask = cache->mask;
2553 int nfs_access_get_cached(struct inode *inode, const struct cred *cred,
2554 u32 *mask, bool may_block)
2558 status = nfs_access_get_cached_rcu(inode, cred, mask);
2560 status = nfs_access_get_cached_locked(inode, cred, mask,
2565 EXPORT_SYMBOL_GPL(nfs_access_get_cached);
2567 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
2569 struct nfs_inode *nfsi = NFS_I(inode);
2570 struct rb_root *root_node = &nfsi->access_cache;
2571 struct rb_node **p = &root_node->rb_node;
2572 struct rb_node *parent = NULL;
2573 struct nfs_access_entry *entry;
2576 spin_lock(&inode->i_lock);
2577 while (*p != NULL) {
2579 entry = rb_entry(parent, struct nfs_access_entry, rb_node);
2580 cmp = cred_fscmp(set->cred, entry->cred);
2583 p = &parent->rb_left;
2585 p = &parent->rb_right;
2589 rb_link_node(&set->rb_node, parent, p);
2590 rb_insert_color(&set->rb_node, root_node);
2591 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2592 spin_unlock(&inode->i_lock);
2595 rb_replace_node(parent, &set->rb_node, root_node);
2596 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2597 list_del(&entry->lru);
2598 spin_unlock(&inode->i_lock);
2599 nfs_access_free_entry(entry);
2602 void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2604 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
2607 RB_CLEAR_NODE(&cache->rb_node);
2608 cache->cred = get_cred(set->cred);
2609 cache->mask = set->mask;
2611 /* The above field assignments must be visible
2612 * before this item appears on the lru. We cannot easily
2613 * use rcu_assign_pointer, so just force the memory barrier.
2616 nfs_access_add_rbtree(inode, cache);
2618 /* Update accounting */
2619 smp_mb__before_atomic();
2620 atomic_long_inc(&nfs_access_nr_entries);
2621 smp_mb__after_atomic();
2623 /* Add inode to global LRU list */
2624 if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2625 spin_lock(&nfs_access_lru_lock);
2626 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2627 list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
2628 &nfs_access_lru_list);
2629 spin_unlock(&nfs_access_lru_lock);
2631 nfs_access_cache_enforce_limit();
2633 EXPORT_SYMBOL_GPL(nfs_access_add_cache);
2635 #define NFS_MAY_READ (NFS_ACCESS_READ)
2636 #define NFS_MAY_WRITE (NFS_ACCESS_MODIFY | \
2637 NFS_ACCESS_EXTEND | \
2639 #define NFS_FILE_MAY_WRITE (NFS_ACCESS_MODIFY | \
2641 #define NFS_DIR_MAY_WRITE NFS_MAY_WRITE
2642 #define NFS_MAY_LOOKUP (NFS_ACCESS_LOOKUP)
2643 #define NFS_MAY_EXECUTE (NFS_ACCESS_EXECUTE)
2645 nfs_access_calc_mask(u32 access_result, umode_t umode)
2649 if (access_result & NFS_MAY_READ)
2651 if (S_ISDIR(umode)) {
2652 if ((access_result & NFS_DIR_MAY_WRITE) == NFS_DIR_MAY_WRITE)
2654 if ((access_result & NFS_MAY_LOOKUP) == NFS_MAY_LOOKUP)
2656 } else if (S_ISREG(umode)) {
2657 if ((access_result & NFS_FILE_MAY_WRITE) == NFS_FILE_MAY_WRITE)
2659 if ((access_result & NFS_MAY_EXECUTE) == NFS_MAY_EXECUTE)
2661 } else if (access_result & NFS_MAY_WRITE)
2666 void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result)
2668 entry->mask = access_result;
2670 EXPORT_SYMBOL_GPL(nfs_access_set_mask);
2672 static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
2674 struct nfs_access_entry cache;
2675 bool may_block = (mask & MAY_NOT_BLOCK) == 0;
2676 int cache_mask = -1;
2679 trace_nfs_access_enter(inode);
2681 status = nfs_access_get_cached(inode, cred, &cache.mask, may_block);
2690 * Determine which access bits we want to ask for...
2692 cache.mask = NFS_ACCESS_READ | NFS_ACCESS_MODIFY | NFS_ACCESS_EXTEND;
2693 if (nfs_server_capable(inode, NFS_CAP_XATTR)) {
2694 cache.mask |= NFS_ACCESS_XAREAD | NFS_ACCESS_XAWRITE |
2697 if (S_ISDIR(inode->i_mode))
2698 cache.mask |= NFS_ACCESS_DELETE | NFS_ACCESS_LOOKUP;
2700 cache.mask |= NFS_ACCESS_EXECUTE;
2702 status = NFS_PROTO(inode)->access(inode, &cache);
2704 if (status == -ESTALE) {
2705 if (!S_ISDIR(inode->i_mode))
2706 nfs_set_inode_stale(inode);
2708 nfs_zap_caches(inode);
2712 nfs_access_add_cache(inode, &cache);
2714 cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode);
2715 if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0)
2718 trace_nfs_access_exit(inode, mask, cache_mask, status);
2722 static int nfs_open_permission_mask(int openflags)
2726 if (openflags & __FMODE_EXEC) {
2727 /* ONLY check exec rights */
2730 if ((openflags & O_ACCMODE) != O_WRONLY)
2732 if ((openflags & O_ACCMODE) != O_RDONLY)
2739 int nfs_may_open(struct inode *inode, const struct cred *cred, int openflags)
2741 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
2743 EXPORT_SYMBOL_GPL(nfs_may_open);
2745 static int nfs_execute_ok(struct inode *inode, int mask)
2747 struct nfs_server *server = NFS_SERVER(inode);
2750 if (S_ISDIR(inode->i_mode))
2752 if (nfs_check_cache_invalid(inode, NFS_INO_INVALID_OTHER)) {
2753 if (mask & MAY_NOT_BLOCK)
2755 ret = __nfs_revalidate_inode(server, inode);
2757 if (ret == 0 && !execute_ok(inode))
2762 int nfs_permission(struct inode *inode, int mask)
2764 const struct cred *cred = current_cred();
2767 nfs_inc_stats(inode, NFSIOS_VFSACCESS);
2769 if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2771 /* Is this sys_access() ? */
2772 if (mask & (MAY_ACCESS | MAY_CHDIR))
2775 switch (inode->i_mode & S_IFMT) {
2779 if ((mask & MAY_OPEN) &&
2780 nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN))
2785 * Optimize away all write operations, since the server
2786 * will check permissions when we perform the op.
2788 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
2793 if (!NFS_PROTO(inode)->access)
2796 res = nfs_do_access(inode, cred, mask);
2798 if (!res && (mask & MAY_EXEC))
2799 res = nfs_execute_ok(inode, mask);
2801 dfprintk(VFS, "NFS: permission(%s/%lu), mask=0x%x, res=%d\n",
2802 inode->i_sb->s_id, inode->i_ino, mask, res);
2805 if (mask & MAY_NOT_BLOCK)
2808 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
2810 res = generic_permission(inode, mask);
2813 EXPORT_SYMBOL_GPL(nfs_permission);
2817 * version-control: t
2818 * kept-new-versions: 5