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>
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"
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 *, umode_t, struct nameidata *);
51 static int nfs_mkdir(struct inode *, struct dentry *, umode_t);
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 *, umode_t, dev_t);
57 static int nfs_rename(struct inode *, struct dentry *,
58 struct inode *, struct dentry *);
59 static int nfs_fsync_dir(struct file *, loff_t, loff_t, 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,
68 .release = nfs_closedir,
69 .fsync = nfs_fsync_dir,
72 const struct inode_operations nfs_dir_inode_operations = {
77 .symlink = nfs_symlink,
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,
92 const struct inode_operations nfs3_dir_inode_operations = {
97 .symlink = nfs_symlink,
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 */
114 static struct file *nfs_atomic_open(struct inode *, struct dentry *,
115 struct opendata *, unsigned, umode_t,
117 const struct inode_operations nfs4_dir_inode_operations = {
118 .create = nfs_create,
119 .lookup = nfs_lookup,
120 .atomic_open = nfs_atomic_open,
122 .unlink = nfs_unlink,
123 .symlink = nfs_symlink,
127 .rename = nfs_rename,
128 .permission = nfs_permission,
129 .getattr = nfs_getattr,
130 .setattr = nfs_setattr,
131 .getxattr = generic_getxattr,
132 .setxattr = generic_setxattr,
133 .listxattr = generic_listxattr,
134 .removexattr = generic_removexattr,
137 #endif /* CONFIG_NFS_V4 */
139 static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred)
141 struct nfs_open_dir_context *ctx;
142 ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
145 ctx->attr_gencount = NFS_I(dir)->attr_gencount;
148 ctx->cred = get_rpccred(cred);
151 return ERR_PTR(-ENOMEM);
154 static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
156 put_rpccred(ctx->cred);
164 nfs_opendir(struct inode *inode, struct file *filp)
167 struct nfs_open_dir_context *ctx;
168 struct rpc_cred *cred;
170 dfprintk(FILE, "NFS: open dir(%s/%s)\n",
171 filp->f_path.dentry->d_parent->d_name.name,
172 filp->f_path.dentry->d_name.name);
174 nfs_inc_stats(inode, NFSIOS_VFSOPEN);
176 cred = rpc_lookup_cred();
178 return PTR_ERR(cred);
179 ctx = alloc_nfs_open_dir_context(inode, cred);
184 filp->private_data = ctx;
185 if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
186 /* This is a mountpoint, so d_revalidate will never
187 * have been called, so we need to refresh the
188 * inode (for close-open consistency) ourselves.
190 __nfs_revalidate_inode(NFS_SERVER(inode), inode);
198 nfs_closedir(struct inode *inode, struct file *filp)
200 put_nfs_open_dir_context(filp->private_data);
204 struct nfs_cache_array_entry {
208 unsigned char d_type;
211 struct nfs_cache_array {
215 struct nfs_cache_array_entry array[0];
218 typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int);
222 unsigned long page_index;
225 loff_t current_index;
226 decode_dirent_t decode;
228 unsigned long timestamp;
229 unsigned long gencount;
230 unsigned int cache_entry_index;
233 } nfs_readdir_descriptor_t;
236 * The caller is responsible for calling nfs_readdir_release_array(page)
239 struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
243 return ERR_PTR(-EIO);
246 return ERR_PTR(-ENOMEM);
251 void nfs_readdir_release_array(struct page *page)
257 * we are freeing strings created by nfs_add_to_readdir_array()
260 void nfs_readdir_clear_array(struct page *page)
262 struct nfs_cache_array *array;
265 array = kmap_atomic(page);
266 for (i = 0; i < array->size; i++)
267 kfree(array->array[i].string.name);
268 kunmap_atomic(array);
272 * the caller is responsible for freeing qstr.name
273 * when called by nfs_readdir_add_to_array, the strings will be freed in
274 * nfs_clear_readdir_array()
277 int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
280 string->name = kmemdup(name, len, GFP_KERNEL);
281 if (string->name == NULL)
284 * Avoid a kmemleak false positive. The pointer to the name is stored
285 * in a page cache page which kmemleak does not scan.
287 kmemleak_not_leak(string->name);
288 string->hash = full_name_hash(name, len);
293 int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
295 struct nfs_cache_array *array = nfs_readdir_get_array(page);
296 struct nfs_cache_array_entry *cache_entry;
300 return PTR_ERR(array);
302 cache_entry = &array->array[array->size];
304 /* Check that this entry lies within the page bounds */
306 if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)
309 cache_entry->cookie = entry->prev_cookie;
310 cache_entry->ino = entry->ino;
311 cache_entry->d_type = entry->d_type;
312 ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
315 array->last_cookie = entry->cookie;
318 array->eof_index = array->size;
320 nfs_readdir_release_array(page);
325 int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
327 loff_t diff = desc->file->f_pos - desc->current_index;
332 if (diff >= array->size) {
333 if (array->eof_index >= 0)
338 index = (unsigned int)diff;
339 *desc->dir_cookie = array->array[index].cookie;
340 desc->cache_entry_index = index;
348 int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
352 int status = -EAGAIN;
354 for (i = 0; i < array->size; i++) {
355 if (array->array[i].cookie == *desc->dir_cookie) {
356 struct nfs_inode *nfsi = NFS_I(desc->file->f_path.dentry->d_inode);
357 struct nfs_open_dir_context *ctx = desc->file->private_data;
359 new_pos = desc->current_index + i;
360 if (ctx->attr_gencount != nfsi->attr_gencount
361 || (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))) {
363 ctx->attr_gencount = nfsi->attr_gencount;
364 } else if (new_pos < desc->file->f_pos) {
366 && ctx->dup_cookie == *desc->dir_cookie) {
367 if (printk_ratelimit()) {
368 pr_notice("NFS: directory %s/%s contains a readdir loop."
369 "Please contact your server vendor. "
370 "The file: %s has duplicate cookie %llu\n",
371 desc->file->f_dentry->d_parent->d_name.name,
372 desc->file->f_dentry->d_name.name,
373 array->array[i].string.name,
379 ctx->dup_cookie = *desc->dir_cookie;
382 desc->file->f_pos = new_pos;
383 desc->cache_entry_index = i;
387 if (array->eof_index >= 0) {
388 status = -EBADCOOKIE;
389 if (*desc->dir_cookie == array->last_cookie)
397 int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
399 struct nfs_cache_array *array;
402 array = nfs_readdir_get_array(desc->page);
404 status = PTR_ERR(array);
408 if (*desc->dir_cookie == 0)
409 status = nfs_readdir_search_for_pos(array, desc);
411 status = nfs_readdir_search_for_cookie(array, desc);
413 if (status == -EAGAIN) {
414 desc->last_cookie = array->last_cookie;
415 desc->current_index += array->size;
418 nfs_readdir_release_array(desc->page);
423 /* Fill a page with xdr information before transferring to the cache page */
425 int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
426 struct nfs_entry *entry, struct file *file, struct inode *inode)
428 struct nfs_open_dir_context *ctx = file->private_data;
429 struct rpc_cred *cred = ctx->cred;
430 unsigned long timestamp, gencount;
435 gencount = nfs_inc_attr_generation_counter();
436 error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages,
437 NFS_SERVER(inode)->dtsize, desc->plus);
439 /* We requested READDIRPLUS, but the server doesn't grok it */
440 if (error == -ENOTSUPP && desc->plus) {
441 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
442 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
448 desc->timestamp = timestamp;
449 desc->gencount = gencount;
454 static int xdr_decode(nfs_readdir_descriptor_t *desc,
455 struct nfs_entry *entry, struct xdr_stream *xdr)
459 error = desc->decode(xdr, entry, desc->plus);
462 entry->fattr->time_start = desc->timestamp;
463 entry->fattr->gencount = desc->gencount;
468 int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
470 if (dentry->d_inode == NULL)
472 if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0)
480 bool nfs_use_readdirplus(struct inode *dir, struct file *filp)
482 if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
484 if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
486 if (filp->f_pos == 0)
492 * This function is called by the lookup code to request the use of
493 * readdirplus to accelerate any future lookups in the same
497 void nfs_advise_use_readdirplus(struct inode *dir)
499 set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags);
503 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
505 struct qstr filename = QSTR_INIT(entry->name, entry->len);
506 struct dentry *dentry;
507 struct dentry *alias;
508 struct inode *dir = parent->d_inode;
511 if (filename.name[0] == '.') {
512 if (filename.len == 1)
514 if (filename.len == 2 && filename.name[1] == '.')
517 filename.hash = full_name_hash(filename.name, filename.len);
519 dentry = d_lookup(parent, &filename);
520 if (dentry != NULL) {
521 if (nfs_same_file(dentry, entry)) {
522 nfs_refresh_inode(dentry->d_inode, entry->fattr);
530 dentry = d_alloc(parent, &filename);
534 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
538 alias = d_materialise_unique(dentry, inode);
542 nfs_set_verifier(alias, nfs_save_change_attribute(dir));
545 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
551 /* Perform conversion from xdr to cache array */
553 int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
554 struct page **xdr_pages, struct page *page, unsigned int buflen)
556 struct xdr_stream stream;
558 struct page *scratch;
559 struct nfs_cache_array *array;
560 unsigned int count = 0;
563 scratch = alloc_page(GFP_KERNEL);
567 xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
568 xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
571 status = xdr_decode(desc, entry, &stream);
573 if (status == -EAGAIN)
581 nfs_prime_dcache(desc->file->f_path.dentry, entry);
583 status = nfs_readdir_add_to_array(entry, page);
586 } while (!entry->eof);
588 if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
589 array = nfs_readdir_get_array(page);
590 if (!IS_ERR(array)) {
591 array->eof_index = array->size;
593 nfs_readdir_release_array(page);
595 status = PTR_ERR(array);
603 void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
606 for (i = 0; i < npages; i++)
611 void nfs_readdir_free_large_page(void *ptr, struct page **pages,
614 nfs_readdir_free_pagearray(pages, npages);
618 * nfs_readdir_large_page will allocate pages that must be freed with a call
619 * to nfs_readdir_free_large_page
622 int nfs_readdir_large_page(struct page **pages, unsigned int npages)
626 for (i = 0; i < npages; i++) {
627 struct page *page = alloc_page(GFP_KERNEL);
635 nfs_readdir_free_pagearray(pages, i);
640 int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
642 struct page *pages[NFS_MAX_READDIR_PAGES];
643 void *pages_ptr = NULL;
644 struct nfs_entry entry;
645 struct file *file = desc->file;
646 struct nfs_cache_array *array;
647 int status = -ENOMEM;
648 unsigned int array_size = ARRAY_SIZE(pages);
650 entry.prev_cookie = 0;
651 entry.cookie = desc->last_cookie;
653 entry.fh = nfs_alloc_fhandle();
654 entry.fattr = nfs_alloc_fattr();
655 entry.server = NFS_SERVER(inode);
656 if (entry.fh == NULL || entry.fattr == NULL)
659 array = nfs_readdir_get_array(page);
661 status = PTR_ERR(array);
664 memset(array, 0, sizeof(struct nfs_cache_array));
665 array->eof_index = -1;
667 status = nfs_readdir_large_page(pages, array_size);
669 goto out_release_array;
672 status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
677 status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
679 if (status == -ENOSPC)
683 } while (array->eof_index < 0);
685 nfs_readdir_free_large_page(pages_ptr, pages, array_size);
687 nfs_readdir_release_array(page);
689 nfs_free_fattr(entry.fattr);
690 nfs_free_fhandle(entry.fh);
695 * Now we cache directories properly, by converting xdr information
696 * to an array that can be used for lookups later. This results in
697 * fewer cache pages, since we can store more information on each page.
698 * We only need to convert from xdr once so future lookups are much simpler
701 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
703 struct inode *inode = desc->file->f_path.dentry->d_inode;
706 ret = nfs_readdir_xdr_to_array(desc, page, inode);
709 SetPageUptodate(page);
711 if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
712 /* Should never happen */
713 nfs_zap_mapping(inode, inode->i_mapping);
723 void cache_page_release(nfs_readdir_descriptor_t *desc)
725 if (!desc->page->mapping)
726 nfs_readdir_clear_array(desc->page);
727 page_cache_release(desc->page);
732 struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
734 return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping,
735 desc->page_index, (filler_t *)nfs_readdir_filler, desc);
739 * Returns 0 if desc->dir_cookie was found on page desc->page_index
742 int find_cache_page(nfs_readdir_descriptor_t *desc)
746 desc->page = get_cache_page(desc);
747 if (IS_ERR(desc->page))
748 return PTR_ERR(desc->page);
750 res = nfs_readdir_search_array(desc);
752 cache_page_release(desc);
756 /* Search for desc->dir_cookie from the beginning of the page cache */
758 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
762 if (desc->page_index == 0) {
763 desc->current_index = 0;
764 desc->last_cookie = 0;
767 res = find_cache_page(desc);
768 } while (res == -EAGAIN);
773 * Once we've found the start of the dirent within a page: fill 'er up...
776 int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
779 struct file *file = desc->file;
782 struct nfs_cache_array *array = NULL;
783 struct nfs_open_dir_context *ctx = file->private_data;
785 array = nfs_readdir_get_array(desc->page);
787 res = PTR_ERR(array);
791 for (i = desc->cache_entry_index; i < array->size; i++) {
792 struct nfs_cache_array_entry *ent;
794 ent = &array->array[i];
795 if (filldir(dirent, ent->string.name, ent->string.len,
796 file->f_pos, nfs_compat_user_ino64(ent->ino),
802 if (i < (array->size-1))
803 *desc->dir_cookie = array->array[i+1].cookie;
805 *desc->dir_cookie = array->last_cookie;
809 if (array->eof_index >= 0)
812 nfs_readdir_release_array(desc->page);
814 cache_page_release(desc);
815 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
816 (unsigned long long)*desc->dir_cookie, res);
821 * If we cannot find a cookie in our cache, we suspect that this is
822 * because it points to a deleted file, so we ask the server to return
823 * whatever it thinks is the next entry. We then feed this to filldir.
824 * If all goes well, we should then be able to find our way round the
825 * cache on the next call to readdir_search_pagecache();
827 * NOTE: we cannot add the anonymous page to the pagecache because
828 * the data it contains might not be page aligned. Besides,
829 * we should already have a complete representation of the
830 * directory in the page cache by the time we get here.
833 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
836 struct page *page = NULL;
838 struct inode *inode = desc->file->f_path.dentry->d_inode;
839 struct nfs_open_dir_context *ctx = desc->file->private_data;
841 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
842 (unsigned long long)*desc->dir_cookie);
844 page = alloc_page(GFP_HIGHUSER);
850 desc->page_index = 0;
851 desc->last_cookie = *desc->dir_cookie;
855 status = nfs_readdir_xdr_to_array(desc, page, inode);
859 status = nfs_do_filldir(desc, dirent, filldir);
862 dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
866 cache_page_release(desc);
870 /* The file offset position represents the dirent entry number. A
871 last cookie cache takes care of the common case of reading the
874 static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
876 struct dentry *dentry = filp->f_path.dentry;
877 struct inode *inode = dentry->d_inode;
878 nfs_readdir_descriptor_t my_desc,
880 struct nfs_open_dir_context *dir_ctx = filp->private_data;
883 dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
884 dentry->d_parent->d_name.name, dentry->d_name.name,
885 (long long)filp->f_pos);
886 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
889 * filp->f_pos points to the dirent entry number.
890 * *desc->dir_cookie has the cookie for the next entry. We have
891 * to either find the entry with the appropriate number or
892 * revalidate the cookie.
894 memset(desc, 0, sizeof(*desc));
897 desc->dir_cookie = &dir_ctx->dir_cookie;
898 desc->decode = NFS_PROTO(inode)->decode_dirent;
899 desc->plus = nfs_use_readdirplus(inode, filp) ? 1 : 0;
901 nfs_block_sillyrename(dentry);
902 res = nfs_revalidate_mapping(inode, filp->f_mapping);
907 res = readdir_search_pagecache(desc);
909 if (res == -EBADCOOKIE) {
911 /* This means either end of directory */
912 if (*desc->dir_cookie && desc->eof == 0) {
913 /* Or that the server has 'lost' a cookie */
914 res = uncached_readdir(desc, dirent, filldir);
920 if (res == -ETOOSMALL && desc->plus) {
921 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
922 nfs_zap_caches(inode);
923 desc->page_index = 0;
931 res = nfs_do_filldir(desc, dirent, filldir);
934 } while (!desc->eof);
936 nfs_unblock_sillyrename(dentry);
939 dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
940 dentry->d_parent->d_name.name, dentry->d_name.name,
945 static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
947 struct dentry *dentry = filp->f_path.dentry;
948 struct inode *inode = dentry->d_inode;
949 struct nfs_open_dir_context *dir_ctx = filp->private_data;
951 dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
952 dentry->d_parent->d_name.name,
956 mutex_lock(&inode->i_mutex);
959 offset += filp->f_pos;
967 if (offset != filp->f_pos) {
968 filp->f_pos = offset;
969 dir_ctx->dir_cookie = 0;
973 mutex_unlock(&inode->i_mutex);
978 * All directory operations under NFS are synchronous, so fsync()
979 * is a dummy operation.
981 static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
984 struct dentry *dentry = filp->f_path.dentry;
985 struct inode *inode = dentry->d_inode;
987 dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
988 dentry->d_parent->d_name.name, dentry->d_name.name,
991 mutex_lock(&inode->i_mutex);
992 nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
993 mutex_unlock(&inode->i_mutex);
998 * nfs_force_lookup_revalidate - Mark the directory as having changed
999 * @dir - pointer to directory inode
1001 * This forces the revalidation code in nfs_lookup_revalidate() to do a
1002 * full lookup on all child dentries of 'dir' whenever a change occurs
1003 * on the server that might have invalidated our dcache.
1005 * The caller should be holding dir->i_lock
1007 void nfs_force_lookup_revalidate(struct inode *dir)
1009 NFS_I(dir)->cache_change_attribute++;
1013 * A check for whether or not the parent directory has changed.
1014 * In the case it has, we assume that the dentries are untrustworthy
1015 * and may need to be looked up again.
1017 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
1019 if (IS_ROOT(dentry))
1021 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
1023 if (!nfs_verify_change_attribute(dir, dentry->d_time))
1025 /* Revalidate nfsi->cache_change_attribute before we declare a match */
1026 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
1028 if (!nfs_verify_change_attribute(dir, dentry->d_time))
1034 * Return the intent data that applies to this particular path component
1036 * Note that the current set of intents only apply to the very last
1037 * component of the path and none of them is set before that last
1040 static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd,
1043 return nd->flags & mask;
1047 * Use intent information to check whether or not we're going to do
1048 * an O_EXCL create using this path component.
1050 static int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
1052 if (NFS_PROTO(dir)->version == 2)
1054 return nd && nfs_lookup_check_intent(nd, LOOKUP_EXCL);
1058 * Inode and filehandle revalidation for lookups.
1060 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
1061 * or if the intent information indicates that we're about to open this
1062 * particular file and the "nocto" mount flag is not set.
1066 int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
1068 struct nfs_server *server = NFS_SERVER(inode);
1070 if (IS_AUTOMOUNT(inode))
1073 /* VFS wants an on-the-wire revalidation */
1074 if (nd->flags & LOOKUP_REVAL)
1076 /* This is an open(2) */
1077 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
1078 !(server->flags & NFS_MOUNT_NOCTO) &&
1079 (S_ISREG(inode->i_mode) ||
1080 S_ISDIR(inode->i_mode)))
1084 return nfs_revalidate_inode(server, inode);
1086 return __nfs_revalidate_inode(server, inode);
1090 * We judge how long we want to trust negative
1091 * dentries by looking at the parent inode mtime.
1093 * If parent mtime has changed, we revalidate, else we wait for a
1094 * period corresponding to the parent's attribute cache timeout value.
1097 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
1098 struct nameidata *nd)
1100 /* Don't revalidate a negative dentry if we're creating a new file */
1101 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
1103 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
1105 return !nfs_check_verifier(dir, dentry);
1109 * This is called every time the dcache has a lookup hit,
1110 * and we should check whether we can really trust that
1113 * NOTE! The hit can be a negative hit too, don't assume
1116 * If the parent directory is seen to have changed, we throw out the
1117 * cached dentry and do a new lookup.
1119 static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
1122 struct inode *inode;
1123 struct dentry *parent;
1124 struct nfs_fh *fhandle = NULL;
1125 struct nfs_fattr *fattr = NULL;
1128 if (nd->flags & LOOKUP_RCU)
1131 parent = dget_parent(dentry);
1132 dir = parent->d_inode;
1133 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
1134 inode = dentry->d_inode;
1137 if (nfs_neg_need_reval(dir, dentry, nd))
1139 goto out_valid_noent;
1142 if (is_bad_inode(inode)) {
1143 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1144 __func__, dentry->d_parent->d_name.name,
1145 dentry->d_name.name);
1149 if (nfs_have_delegation(inode, FMODE_READ))
1150 goto out_set_verifier;
1152 /* Force a full look up iff the parent directory has changed */
1153 if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) {
1154 if (nfs_lookup_verify_inode(inode, nd))
1155 goto out_zap_parent;
1159 if (NFS_STALE(inode))
1163 fhandle = nfs_alloc_fhandle();
1164 fattr = nfs_alloc_fattr();
1165 if (fhandle == NULL || fattr == NULL)
1168 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
1171 if (nfs_compare_fh(NFS_FH(inode), fhandle))
1173 if ((error = nfs_refresh_inode(inode, fattr)) != 0)
1176 nfs_free_fattr(fattr);
1177 nfs_free_fhandle(fhandle);
1179 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1181 /* Success: notify readdir to use READDIRPLUS */
1182 nfs_advise_use_readdirplus(dir);
1185 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
1186 __func__, dentry->d_parent->d_name.name,
1187 dentry->d_name.name);
1190 nfs_zap_caches(dir);
1192 nfs_mark_for_revalidate(dir);
1193 if (inode && S_ISDIR(inode->i_mode)) {
1194 /* Purge readdir caches. */
1195 nfs_zap_caches(inode);
1196 /* If we have submounts, don't unhash ! */
1197 if (have_submounts(dentry))
1199 if (dentry->d_flags & DCACHE_DISCONNECTED)
1201 shrink_dcache_parent(dentry);
1204 nfs_free_fattr(fattr);
1205 nfs_free_fhandle(fhandle);
1207 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
1208 __func__, dentry->d_parent->d_name.name,
1209 dentry->d_name.name);
1212 nfs_free_fattr(fattr);
1213 nfs_free_fhandle(fhandle);
1215 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n",
1216 __func__, dentry->d_parent->d_name.name,
1217 dentry->d_name.name, error);
1222 * This is called from dput() when d_count is going to 0.
1224 static int nfs_dentry_delete(const struct dentry *dentry)
1226 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
1227 dentry->d_parent->d_name.name, dentry->d_name.name,
1230 /* Unhash any dentry with a stale inode */
1231 if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode))
1234 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1235 /* Unhash it, so that ->d_iput() would be called */
1238 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
1239 /* Unhash it, so that ancestors of killed async unlink
1240 * files will be cleaned up during umount */
1247 static void nfs_drop_nlink(struct inode *inode)
1249 spin_lock(&inode->i_lock);
1250 if (inode->i_nlink > 0)
1252 spin_unlock(&inode->i_lock);
1256 * Called when the dentry loses inode.
1257 * We use it to clean up silly-renamed files.
1259 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
1261 if (S_ISDIR(inode->i_mode))
1262 /* drop any readdir cache as it could easily be old */
1263 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
1265 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1267 nfs_complete_unlink(dentry, inode);
1272 static void nfs_d_release(struct dentry *dentry)
1274 /* free cached devname value, if it survived that far */
1275 if (unlikely(dentry->d_fsdata)) {
1276 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1279 kfree(dentry->d_fsdata);
1283 const struct dentry_operations nfs_dentry_operations = {
1284 .d_revalidate = nfs_lookup_revalidate,
1285 .d_delete = nfs_dentry_delete,
1286 .d_iput = nfs_dentry_iput,
1287 .d_automount = nfs_d_automount,
1288 .d_release = nfs_d_release,
1291 static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
1294 struct dentry *parent;
1295 struct inode *inode = NULL;
1296 struct nfs_fh *fhandle = NULL;
1297 struct nfs_fattr *fattr = NULL;
1300 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
1301 dentry->d_parent->d_name.name, dentry->d_name.name);
1302 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
1304 res = ERR_PTR(-ENAMETOOLONG);
1305 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
1309 * If we're doing an exclusive create, optimize away the lookup
1310 * but don't hash the dentry.
1312 if (nfs_is_exclusive_create(dir, nd)) {
1313 d_instantiate(dentry, NULL);
1318 res = ERR_PTR(-ENOMEM);
1319 fhandle = nfs_alloc_fhandle();
1320 fattr = nfs_alloc_fattr();
1321 if (fhandle == NULL || fattr == NULL)
1324 parent = dentry->d_parent;
1325 /* Protect against concurrent sillydeletes */
1326 nfs_block_sillyrename(parent);
1327 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
1328 if (error == -ENOENT)
1331 res = ERR_PTR(error);
1332 goto out_unblock_sillyrename;
1334 inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1335 res = ERR_CAST(inode);
1337 goto out_unblock_sillyrename;
1339 /* Success: notify readdir to use READDIRPLUS */
1340 nfs_advise_use_readdirplus(dir);
1343 res = d_materialise_unique(dentry, inode);
1346 goto out_unblock_sillyrename;
1349 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1350 out_unblock_sillyrename:
1351 nfs_unblock_sillyrename(parent);
1353 nfs_free_fattr(fattr);
1354 nfs_free_fhandle(fhandle);
1358 #ifdef CONFIG_NFS_V4
1359 static int nfs4_lookup_revalidate(struct dentry *, struct nameidata *);
1361 const struct dentry_operations nfs4_dentry_operations = {
1362 .d_revalidate = nfs4_lookup_revalidate,
1363 .d_delete = nfs_dentry_delete,
1364 .d_iput = nfs_dentry_iput,
1365 .d_automount = nfs_d_automount,
1366 .d_release = nfs_d_release,
1369 static fmode_t flags_to_mode(int flags)
1371 fmode_t res = (__force fmode_t)flags & FMODE_EXEC;
1372 if ((flags & O_ACCMODE) != O_WRONLY)
1374 if ((flags & O_ACCMODE) != O_RDONLY)
1379 static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags)
1381 return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
1384 static int do_open(struct inode *inode, struct file *filp)
1386 nfs_fscache_set_inode_cookie(inode, filp);
1390 static struct file *nfs_finish_open(struct nfs_open_context *ctx,
1391 struct dentry *dentry,
1392 struct opendata *od, unsigned open_flags,
1398 if (ctx->dentry != dentry) {
1400 ctx->dentry = dget(dentry);
1403 /* If the open_intent is for execute, we have an extra check to make */
1404 if (ctx->mode & FMODE_EXEC) {
1405 err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags);
1407 filp = ERR_PTR(err);
1412 filp = finish_open(od, dentry, do_open, opened);
1414 nfs_file_set_open_context(filp, ctx);
1417 put_nfs_open_context(ctx);
1421 static struct file *nfs_atomic_open(struct inode *dir, struct dentry *dentry,
1422 struct opendata *od, unsigned open_flags,
1423 umode_t mode, int *opened)
1425 struct nfs_open_context *ctx;
1427 struct iattr attr = { .ia_valid = ATTR_OPEN };
1428 struct inode *inode;
1432 /* Expect a negative dentry */
1433 BUG_ON(dentry->d_inode);
1435 dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n",
1436 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1438 /* NFS only supports OPEN on regular files */
1439 if ((open_flags & O_DIRECTORY)) {
1441 if (!d_unhashed(dentry)) {
1443 * Hashed negative dentry with O_DIRECTORY: dentry was
1444 * revalidated and is fine, no need to perform lookup
1452 err = -ENAMETOOLONG;
1453 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
1456 if (open_flags & O_CREAT) {
1457 attr.ia_valid |= ATTR_MODE;
1458 attr.ia_mode = mode & ~current_umask();
1460 if (open_flags & O_TRUNC) {
1461 attr.ia_valid |= ATTR_SIZE;
1465 ctx = create_nfs_open_context(dentry, open_flags);
1470 nfs_block_sillyrename(dentry->d_parent);
1471 inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
1473 if (IS_ERR(inode)) {
1474 nfs_unblock_sillyrename(dentry->d_parent);
1475 put_nfs_open_context(ctx);
1476 err = PTR_ERR(inode);
1479 d_add(dentry, NULL);
1485 if (!(open_flags & O_NOFOLLOW))
1494 res = d_add_unique(dentry, inode);
1498 nfs_unblock_sillyrename(dentry->d_parent);
1499 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1501 filp = nfs_finish_open(ctx, dentry, od, open_flags, opened);
1507 return ERR_PTR(err);
1510 res = nfs_lookup(dir, dentry, NULL);
1515 finish_no_open(od, res);
1519 static int nfs4_lookup_revalidate(struct dentry *dentry, struct nameidata *nd)
1521 struct dentry *parent = NULL;
1522 struct inode *inode;
1526 if (nd->flags & LOOKUP_RCU)
1529 if (!(nd->flags & LOOKUP_OPEN) || (nd->flags & LOOKUP_DIRECTORY))
1531 if (d_mountpoint(dentry))
1534 inode = dentry->d_inode;
1535 parent = dget_parent(dentry);
1536 dir = parent->d_inode;
1538 /* We can't create new files in nfs_open_revalidate(), so we
1539 * optimize away revalidation of negative dentries.
1541 if (inode == NULL) {
1542 if (!nfs_neg_need_reval(dir, dentry, nd))
1547 /* NFS only supports OPEN on regular files */
1548 if (!S_ISREG(inode->i_mode))
1550 /* We cannot do exclusive creation on a positive dentry */
1551 if (nd && nd->flags & LOOKUP_EXCL)
1554 /* Let f_op->open() actually open (and revalidate) the file */
1564 return nfs_lookup_revalidate(dentry, nd);
1567 #endif /* CONFIG_NFSV4 */
1570 * Code common to create, mkdir, and mknod.
1572 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1573 struct nfs_fattr *fattr)
1575 struct dentry *parent = dget_parent(dentry);
1576 struct inode *dir = parent->d_inode;
1577 struct inode *inode;
1578 int error = -EACCES;
1582 /* We may have been initialized further down */
1583 if (dentry->d_inode)
1585 if (fhandle->size == 0) {
1586 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
1590 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1591 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1592 struct nfs_server *server = NFS_SB(dentry->d_sb);
1593 error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
1597 inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1598 error = PTR_ERR(inode);
1601 d_add(dentry, inode);
1606 nfs_mark_for_revalidate(dir);
1612 * Following a failed create operation, we drop the dentry rather
1613 * than retain a negative dentry. This avoids a problem in the event
1614 * that the operation succeeded on the server, but an error in the
1615 * reply path made it appear to have failed.
1617 static int nfs_create(struct inode *dir, struct dentry *dentry,
1618 umode_t mode, struct nameidata *nd)
1622 int open_flags = O_CREAT|O_EXCL;
1624 dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
1625 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1627 attr.ia_mode = mode;
1628 attr.ia_valid = ATTR_MODE;
1630 if (nd && !(nd->flags & LOOKUP_EXCL))
1631 open_flags = O_CREAT;
1633 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
1643 * See comments for nfs_proc_create regarding failed operations.
1646 nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1651 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
1652 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1654 if (!new_valid_dev(rdev))
1657 attr.ia_mode = mode;
1658 attr.ia_valid = ATTR_MODE;
1660 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
1670 * See comments for nfs_proc_create regarding failed operations.
1672 static int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
1677 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
1678 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1680 attr.ia_valid = ATTR_MODE;
1681 attr.ia_mode = mode | S_IFDIR;
1683 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
1692 static void nfs_dentry_handle_enoent(struct dentry *dentry)
1694 if (dentry->d_inode != NULL && !d_unhashed(dentry))
1698 static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1702 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
1703 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1705 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
1706 /* Ensure the VFS deletes this inode */
1707 if (error == 0 && dentry->d_inode != NULL)
1708 clear_nlink(dentry->d_inode);
1709 else if (error == -ENOENT)
1710 nfs_dentry_handle_enoent(dentry);
1716 * Remove a file after making sure there are no pending writes,
1717 * and after checking that the file has only one user.
1719 * We invalidate the attribute cache and free the inode prior to the operation
1720 * to avoid possible races if the server reuses the inode.
1722 static int nfs_safe_remove(struct dentry *dentry)
1724 struct inode *dir = dentry->d_parent->d_inode;
1725 struct inode *inode = dentry->d_inode;
1728 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1729 dentry->d_parent->d_name.name, dentry->d_name.name);
1731 /* If the dentry was sillyrenamed, we simply call d_delete() */
1732 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1737 if (inode != NULL) {
1738 nfs_inode_return_delegation(inode);
1739 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1740 /* The VFS may want to delete this inode */
1742 nfs_drop_nlink(inode);
1743 nfs_mark_for_revalidate(inode);
1745 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1746 if (error == -ENOENT)
1747 nfs_dentry_handle_enoent(dentry);
1752 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1753 * belongs to an active ".nfs..." file and we return -EBUSY.
1755 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1757 static int nfs_unlink(struct inode *dir, struct dentry *dentry)
1760 int need_rehash = 0;
1762 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1763 dir->i_ino, dentry->d_name.name);
1765 spin_lock(&dentry->d_lock);
1766 if (dentry->d_count > 1) {
1767 spin_unlock(&dentry->d_lock);
1768 /* Start asynchronous writeout of the inode */
1769 write_inode_now(dentry->d_inode, 0);
1770 error = nfs_sillyrename(dir, dentry);
1773 if (!d_unhashed(dentry)) {
1777 spin_unlock(&dentry->d_lock);
1778 error = nfs_safe_remove(dentry);
1779 if (!error || error == -ENOENT) {
1780 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1781 } else if (need_rehash)
1787 * To create a symbolic link, most file systems instantiate a new inode,
1788 * add a page to it containing the path, then write it out to the disk
1789 * using prepare_write/commit_write.
1791 * Unfortunately the NFS client can't create the in-core inode first
1792 * because it needs a file handle to create an in-core inode (see
1793 * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the
1794 * symlink request has completed on the server.
1796 * So instead we allocate a raw page, copy the symname into it, then do
1797 * the SYMLINK request with the page as the buffer. If it succeeds, we
1798 * now have a new file handle and can instantiate an in-core NFS inode
1799 * and move the raw page into its mapping.
1801 static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1803 struct pagevec lru_pvec;
1807 unsigned int pathlen = strlen(symname);
1810 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1811 dir->i_ino, dentry->d_name.name, symname);
1813 if (pathlen > PAGE_SIZE)
1814 return -ENAMETOOLONG;
1816 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1817 attr.ia_valid = ATTR_MODE;
1819 page = alloc_page(GFP_HIGHUSER);
1823 kaddr = kmap_atomic(page);
1824 memcpy(kaddr, symname, pathlen);
1825 if (pathlen < PAGE_SIZE)
1826 memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
1827 kunmap_atomic(kaddr);
1829 error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
1831 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n",
1832 dir->i_sb->s_id, dir->i_ino,
1833 dentry->d_name.name, symname, error);
1840 * No big deal if we can't add this page to the page cache here.
1841 * READLINK will get the missing page from the server if needed.
1843 pagevec_init(&lru_pvec, 0);
1844 if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0,
1846 pagevec_add(&lru_pvec, page);
1847 pagevec_lru_add_file(&lru_pvec);
1848 SetPageUptodate(page);
1857 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1859 struct inode *inode = old_dentry->d_inode;
1862 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
1863 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1864 dentry->d_parent->d_name.name, dentry->d_name.name);
1866 nfs_inode_return_delegation(inode);
1869 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1872 d_add(dentry, inode);
1879 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
1880 * different file handle for the same inode after a rename (e.g. when
1881 * moving to a different directory). A fail-safe method to do so would
1882 * be to look up old_dir/old_name, create a link to new_dir/new_name and
1883 * rename the old file using the sillyrename stuff. This way, the original
1884 * file in old_dir will go away when the last process iput()s the inode.
1888 * It actually works quite well. One needs to have the possibility for
1889 * at least one ".nfs..." file in each directory the file ever gets
1890 * moved or linked to which happens automagically with the new
1891 * implementation that only depends on the dcache stuff instead of
1892 * using the inode layer
1894 * Unfortunately, things are a little more complicated than indicated
1895 * above. For a cross-directory move, we want to make sure we can get
1896 * rid of the old inode after the operation. This means there must be
1897 * no pending writes (if it's a file), and the use count must be 1.
1898 * If these conditions are met, we can drop the dentries before doing
1901 static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1902 struct inode *new_dir, struct dentry *new_dentry)
1904 struct inode *old_inode = old_dentry->d_inode;
1905 struct inode *new_inode = new_dentry->d_inode;
1906 struct dentry *dentry = NULL, *rehash = NULL;
1909 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
1910 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1911 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
1912 new_dentry->d_count);
1915 * For non-directories, check whether the target is busy and if so,
1916 * make a copy of the dentry and then do a silly-rename. If the
1917 * silly-rename succeeds, the copied dentry is hashed and becomes
1920 if (new_inode && !S_ISDIR(new_inode->i_mode)) {
1922 * To prevent any new references to the target during the
1923 * rename, we unhash the dentry in advance.
1925 if (!d_unhashed(new_dentry)) {
1927 rehash = new_dentry;
1930 if (new_dentry->d_count > 2) {
1933 /* copy the target dentry's name */
1934 dentry = d_alloc(new_dentry->d_parent,
1935 &new_dentry->d_name);
1939 /* silly-rename the existing target ... */
1940 err = nfs_sillyrename(new_dir, new_dentry);
1944 new_dentry = dentry;
1950 nfs_inode_return_delegation(old_inode);
1951 if (new_inode != NULL)
1952 nfs_inode_return_delegation(new_inode);
1954 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
1955 new_dir, &new_dentry->d_name);
1956 nfs_mark_for_revalidate(old_inode);
1961 if (new_inode != NULL)
1962 nfs_drop_nlink(new_inode);
1963 d_move(old_dentry, new_dentry);
1964 nfs_set_verifier(new_dentry,
1965 nfs_save_change_attribute(new_dir));
1966 } else if (error == -ENOENT)
1967 nfs_dentry_handle_enoent(old_dentry);
1969 /* new dentry created? */
1975 static DEFINE_SPINLOCK(nfs_access_lru_lock);
1976 static LIST_HEAD(nfs_access_lru_list);
1977 static atomic_long_t nfs_access_nr_entries;
1979 static void nfs_access_free_entry(struct nfs_access_entry *entry)
1981 put_rpccred(entry->cred);
1983 smp_mb__before_atomic_dec();
1984 atomic_long_dec(&nfs_access_nr_entries);
1985 smp_mb__after_atomic_dec();
1988 static void nfs_access_free_list(struct list_head *head)
1990 struct nfs_access_entry *cache;
1992 while (!list_empty(head)) {
1993 cache = list_entry(head->next, struct nfs_access_entry, lru);
1994 list_del(&cache->lru);
1995 nfs_access_free_entry(cache);
1999 int nfs_access_cache_shrinker(struct shrinker *shrink,
2000 struct shrink_control *sc)
2003 struct nfs_inode *nfsi, *next;
2004 struct nfs_access_entry *cache;
2005 int nr_to_scan = sc->nr_to_scan;
2006 gfp_t gfp_mask = sc->gfp_mask;
2008 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
2009 return (nr_to_scan == 0) ? 0 : -1;
2011 spin_lock(&nfs_access_lru_lock);
2012 list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
2013 struct inode *inode;
2015 if (nr_to_scan-- == 0)
2017 inode = &nfsi->vfs_inode;
2018 spin_lock(&inode->i_lock);
2019 if (list_empty(&nfsi->access_cache_entry_lru))
2020 goto remove_lru_entry;
2021 cache = list_entry(nfsi->access_cache_entry_lru.next,
2022 struct nfs_access_entry, lru);
2023 list_move(&cache->lru, &head);
2024 rb_erase(&cache->rb_node, &nfsi->access_cache);
2025 if (!list_empty(&nfsi->access_cache_entry_lru))
2026 list_move_tail(&nfsi->access_cache_inode_lru,
2027 &nfs_access_lru_list);
2030 list_del_init(&nfsi->access_cache_inode_lru);
2031 smp_mb__before_clear_bit();
2032 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
2033 smp_mb__after_clear_bit();
2035 spin_unlock(&inode->i_lock);
2037 spin_unlock(&nfs_access_lru_lock);
2038 nfs_access_free_list(&head);
2039 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
2042 static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
2044 struct rb_root *root_node = &nfsi->access_cache;
2046 struct nfs_access_entry *entry;
2048 /* Unhook entries from the cache */
2049 while ((n = rb_first(root_node)) != NULL) {
2050 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2051 rb_erase(n, root_node);
2052 list_move(&entry->lru, head);
2054 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
2057 void nfs_access_zap_cache(struct inode *inode)
2061 if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
2063 /* Remove from global LRU init */
2064 spin_lock(&nfs_access_lru_lock);
2065 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2066 list_del_init(&NFS_I(inode)->access_cache_inode_lru);
2068 spin_lock(&inode->i_lock);
2069 __nfs_access_zap_cache(NFS_I(inode), &head);
2070 spin_unlock(&inode->i_lock);
2071 spin_unlock(&nfs_access_lru_lock);
2072 nfs_access_free_list(&head);
2075 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
2077 struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
2078 struct nfs_access_entry *entry;
2081 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2083 if (cred < entry->cred)
2085 else if (cred > entry->cred)
2093 static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
2095 struct nfs_inode *nfsi = NFS_I(inode);
2096 struct nfs_access_entry *cache;
2099 spin_lock(&inode->i_lock);
2100 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
2102 cache = nfs_access_search_rbtree(inode, cred);
2105 if (!nfs_have_delegated_attributes(inode) &&
2106 !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
2108 res->jiffies = cache->jiffies;
2109 res->cred = cache->cred;
2110 res->mask = cache->mask;
2111 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2114 spin_unlock(&inode->i_lock);
2117 rb_erase(&cache->rb_node, &nfsi->access_cache);
2118 list_del(&cache->lru);
2119 spin_unlock(&inode->i_lock);
2120 nfs_access_free_entry(cache);
2123 spin_unlock(&inode->i_lock);
2124 nfs_access_zap_cache(inode);
2128 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
2130 struct nfs_inode *nfsi = NFS_I(inode);
2131 struct rb_root *root_node = &nfsi->access_cache;
2132 struct rb_node **p = &root_node->rb_node;
2133 struct rb_node *parent = NULL;
2134 struct nfs_access_entry *entry;
2136 spin_lock(&inode->i_lock);
2137 while (*p != NULL) {
2139 entry = rb_entry(parent, struct nfs_access_entry, rb_node);
2141 if (set->cred < entry->cred)
2142 p = &parent->rb_left;
2143 else if (set->cred > entry->cred)
2144 p = &parent->rb_right;
2148 rb_link_node(&set->rb_node, parent, p);
2149 rb_insert_color(&set->rb_node, root_node);
2150 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2151 spin_unlock(&inode->i_lock);
2154 rb_replace_node(parent, &set->rb_node, root_node);
2155 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2156 list_del(&entry->lru);
2157 spin_unlock(&inode->i_lock);
2158 nfs_access_free_entry(entry);
2161 static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2163 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
2166 RB_CLEAR_NODE(&cache->rb_node);
2167 cache->jiffies = set->jiffies;
2168 cache->cred = get_rpccred(set->cred);
2169 cache->mask = set->mask;
2171 nfs_access_add_rbtree(inode, cache);
2173 /* Update accounting */
2174 smp_mb__before_atomic_inc();
2175 atomic_long_inc(&nfs_access_nr_entries);
2176 smp_mb__after_atomic_inc();
2178 /* Add inode to global LRU list */
2179 if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2180 spin_lock(&nfs_access_lru_lock);
2181 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2182 list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
2183 &nfs_access_lru_list);
2184 spin_unlock(&nfs_access_lru_lock);
2188 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
2190 struct nfs_access_entry cache;
2193 status = nfs_access_get_cached(inode, cred, &cache);
2197 /* Be clever: ask server to check for all possible rights */
2198 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
2200 cache.jiffies = jiffies;
2201 status = NFS_PROTO(inode)->access(inode, &cache);
2203 if (status == -ESTALE) {
2204 nfs_zap_caches(inode);
2205 if (!S_ISDIR(inode->i_mode))
2206 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
2210 nfs_access_add_cache(inode, &cache);
2212 if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2217 static int nfs_open_permission_mask(int openflags)
2221 if ((openflags & O_ACCMODE) != O_WRONLY)
2223 if ((openflags & O_ACCMODE) != O_RDONLY)
2225 if (openflags & __FMODE_EXEC)
2230 int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
2232 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
2235 int nfs_permission(struct inode *inode, int mask)
2237 struct rpc_cred *cred;
2240 if (mask & MAY_NOT_BLOCK)
2243 nfs_inc_stats(inode, NFSIOS_VFSACCESS);
2245 if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2247 /* Is this sys_access() ? */
2248 if (mask & (MAY_ACCESS | MAY_CHDIR))
2251 switch (inode->i_mode & S_IFMT) {
2255 /* NFSv4 has atomic_open... */
2256 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
2257 && (mask & MAY_OPEN)
2258 && !(mask & MAY_EXEC))
2263 * Optimize away all write operations, since the server
2264 * will check permissions when we perform the op.
2266 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
2271 if (!NFS_PROTO(inode)->access)
2274 cred = rpc_lookup_cred();
2275 if (!IS_ERR(cred)) {
2276 res = nfs_do_access(inode, cred, mask);
2279 res = PTR_ERR(cred);
2281 if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
2284 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
2285 inode->i_sb->s_id, inode->i_ino, mask, res);
2288 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
2290 res = generic_permission(inode, mask);
2296 * version-control: t
2297 * kept-new-versions: 5