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/module.h>
21 #include <linux/time.h>
22 #include <linux/errno.h>
23 #include <linux/stat.h>
24 #include <linux/fcntl.h>
25 #include <linux/string.h>
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
29 #include <linux/sunrpc/clnt.h>
30 #include <linux/nfs_fs.h>
31 #include <linux/nfs_mount.h>
32 #include <linux/pagemap.h>
33 #include <linux/pagevec.h>
34 #include <linux/namei.h>
35 #include <linux/mount.h>
36 #include <linux/sched.h>
37 #include <linux/kmemleak.h>
38 #include <linux/xattr.h>
40 #include "delegation.h"
45 /* #define NFS_DEBUG_VERBOSE 1 */
47 static int nfs_opendir(struct inode *, struct file *);
48 static int nfs_closedir(struct inode *, struct file *);
49 static int nfs_readdir(struct file *, void *, filldir_t);
50 static int nfs_fsync_dir(struct file *, loff_t, loff_t, int);
51 static loff_t nfs_llseek_dir(struct file *, loff_t, int);
52 static void nfs_readdir_clear_array(struct page*);
54 const struct file_operations nfs_dir_operations = {
55 .llseek = nfs_llseek_dir,
56 .read = generic_read_dir,
57 .readdir = nfs_readdir,
59 .release = nfs_closedir,
60 .fsync = nfs_fsync_dir,
63 const struct address_space_operations nfs_dir_aops = {
64 .freepage = nfs_readdir_clear_array,
67 static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred)
69 struct nfs_open_dir_context *ctx;
70 ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
73 ctx->attr_gencount = NFS_I(dir)->attr_gencount;
76 ctx->cred = get_rpccred(cred);
79 return ERR_PTR(-ENOMEM);
82 static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
84 put_rpccred(ctx->cred);
92 nfs_opendir(struct inode *inode, struct file *filp)
95 struct nfs_open_dir_context *ctx;
96 struct rpc_cred *cred;
98 dfprintk(FILE, "NFS: open dir(%s/%s)\n",
99 filp->f_path.dentry->d_parent->d_name.name,
100 filp->f_path.dentry->d_name.name);
102 nfs_inc_stats(inode, NFSIOS_VFSOPEN);
104 cred = rpc_lookup_cred();
106 return PTR_ERR(cred);
107 ctx = alloc_nfs_open_dir_context(inode, cred);
112 filp->private_data = ctx;
113 if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
114 /* This is a mountpoint, so d_revalidate will never
115 * have been called, so we need to refresh the
116 * inode (for close-open consistency) ourselves.
118 __nfs_revalidate_inode(NFS_SERVER(inode), inode);
126 nfs_closedir(struct inode *inode, struct file *filp)
128 put_nfs_open_dir_context(filp->private_data);
132 struct nfs_cache_array_entry {
136 unsigned char d_type;
139 struct nfs_cache_array {
143 struct nfs_cache_array_entry array[0];
146 typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int);
150 unsigned long page_index;
153 loff_t current_index;
154 decode_dirent_t decode;
156 unsigned long timestamp;
157 unsigned long gencount;
158 unsigned int cache_entry_index;
161 } nfs_readdir_descriptor_t;
164 * The caller is responsible for calling nfs_readdir_release_array(page)
167 struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
171 return ERR_PTR(-EIO);
174 return ERR_PTR(-ENOMEM);
179 void nfs_readdir_release_array(struct page *page)
185 * we are freeing strings created by nfs_add_to_readdir_array()
188 void nfs_readdir_clear_array(struct page *page)
190 struct nfs_cache_array *array;
193 array = kmap_atomic(page);
194 for (i = 0; i < array->size; i++)
195 kfree(array->array[i].string.name);
196 kunmap_atomic(array);
200 * the caller is responsible for freeing qstr.name
201 * when called by nfs_readdir_add_to_array, the strings will be freed in
202 * nfs_clear_readdir_array()
205 int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
208 string->name = kmemdup(name, len, GFP_KERNEL);
209 if (string->name == NULL)
212 * Avoid a kmemleak false positive. The pointer to the name is stored
213 * in a page cache page which kmemleak does not scan.
215 kmemleak_not_leak(string->name);
216 string->hash = full_name_hash(name, len);
221 int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
223 struct nfs_cache_array *array = nfs_readdir_get_array(page);
224 struct nfs_cache_array_entry *cache_entry;
228 return PTR_ERR(array);
230 cache_entry = &array->array[array->size];
232 /* Check that this entry lies within the page bounds */
234 if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)
237 cache_entry->cookie = entry->prev_cookie;
238 cache_entry->ino = entry->ino;
239 cache_entry->d_type = entry->d_type;
240 ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
243 array->last_cookie = entry->cookie;
246 array->eof_index = array->size;
248 nfs_readdir_release_array(page);
253 int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
255 loff_t diff = desc->file->f_pos - desc->current_index;
260 if (diff >= array->size) {
261 if (array->eof_index >= 0)
266 index = (unsigned int)diff;
267 *desc->dir_cookie = array->array[index].cookie;
268 desc->cache_entry_index = index;
276 int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
280 int status = -EAGAIN;
282 for (i = 0; i < array->size; i++) {
283 if (array->array[i].cookie == *desc->dir_cookie) {
284 struct nfs_inode *nfsi = NFS_I(file_inode(desc->file));
285 struct nfs_open_dir_context *ctx = desc->file->private_data;
287 new_pos = desc->current_index + i;
288 if (ctx->attr_gencount != nfsi->attr_gencount
289 || (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))) {
291 ctx->attr_gencount = nfsi->attr_gencount;
292 } else if (new_pos < desc->file->f_pos) {
294 && ctx->dup_cookie == *desc->dir_cookie) {
295 if (printk_ratelimit()) {
296 pr_notice("NFS: directory %s/%s contains a readdir loop."
297 "Please contact your server vendor. "
298 "The file: %s has duplicate cookie %llu\n",
299 desc->file->f_dentry->d_parent->d_name.name,
300 desc->file->f_dentry->d_name.name,
301 array->array[i].string.name,
307 ctx->dup_cookie = *desc->dir_cookie;
310 desc->file->f_pos = new_pos;
311 desc->cache_entry_index = i;
315 if (array->eof_index >= 0) {
316 status = -EBADCOOKIE;
317 if (*desc->dir_cookie == array->last_cookie)
325 int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
327 struct nfs_cache_array *array;
330 array = nfs_readdir_get_array(desc->page);
332 status = PTR_ERR(array);
336 if (*desc->dir_cookie == 0)
337 status = nfs_readdir_search_for_pos(array, desc);
339 status = nfs_readdir_search_for_cookie(array, desc);
341 if (status == -EAGAIN) {
342 desc->last_cookie = array->last_cookie;
343 desc->current_index += array->size;
346 nfs_readdir_release_array(desc->page);
351 /* Fill a page with xdr information before transferring to the cache page */
353 int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
354 struct nfs_entry *entry, struct file *file, struct inode *inode)
356 struct nfs_open_dir_context *ctx = file->private_data;
357 struct rpc_cred *cred = ctx->cred;
358 unsigned long timestamp, gencount;
363 gencount = nfs_inc_attr_generation_counter();
364 error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages,
365 NFS_SERVER(inode)->dtsize, desc->plus);
367 /* We requested READDIRPLUS, but the server doesn't grok it */
368 if (error == -ENOTSUPP && desc->plus) {
369 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
370 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
376 desc->timestamp = timestamp;
377 desc->gencount = gencount;
382 static int xdr_decode(nfs_readdir_descriptor_t *desc,
383 struct nfs_entry *entry, struct xdr_stream *xdr)
387 error = desc->decode(xdr, entry, desc->plus);
390 entry->fattr->time_start = desc->timestamp;
391 entry->fattr->gencount = desc->gencount;
396 int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
398 if (dentry->d_inode == NULL)
400 if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0)
408 bool nfs_use_readdirplus(struct inode *dir, struct file *filp)
410 if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
412 if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
414 if (filp->f_pos == 0)
420 * This function is called by the lookup code to request the use of
421 * readdirplus to accelerate any future lookups in the same
425 void nfs_advise_use_readdirplus(struct inode *dir)
427 set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags);
431 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
433 struct qstr filename = QSTR_INIT(entry->name, entry->len);
434 struct dentry *dentry;
435 struct dentry *alias;
436 struct inode *dir = parent->d_inode;
439 if (filename.name[0] == '.') {
440 if (filename.len == 1)
442 if (filename.len == 2 && filename.name[1] == '.')
445 filename.hash = full_name_hash(filename.name, filename.len);
447 dentry = d_lookup(parent, &filename);
448 if (dentry != NULL) {
449 if (nfs_same_file(dentry, entry)) {
450 nfs_refresh_inode(dentry->d_inode, entry->fattr);
453 if (d_invalidate(dentry) != 0)
459 dentry = d_alloc(parent, &filename);
463 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);
467 alias = d_materialise_unique(dentry, inode);
471 nfs_set_verifier(alias, nfs_save_change_attribute(dir));
474 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
480 /* Perform conversion from xdr to cache array */
482 int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
483 struct page **xdr_pages, struct page *page, unsigned int buflen)
485 struct xdr_stream stream;
487 struct page *scratch;
488 struct nfs_cache_array *array;
489 unsigned int count = 0;
492 scratch = alloc_page(GFP_KERNEL);
496 xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
497 xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
500 status = xdr_decode(desc, entry, &stream);
502 if (status == -EAGAIN)
510 nfs_prime_dcache(desc->file->f_path.dentry, entry);
512 status = nfs_readdir_add_to_array(entry, page);
515 } while (!entry->eof);
517 if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
518 array = nfs_readdir_get_array(page);
519 if (!IS_ERR(array)) {
520 array->eof_index = array->size;
522 nfs_readdir_release_array(page);
524 status = PTR_ERR(array);
532 void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
535 for (i = 0; i < npages; i++)
540 void nfs_readdir_free_large_page(void *ptr, struct page **pages,
543 nfs_readdir_free_pagearray(pages, npages);
547 * nfs_readdir_large_page will allocate pages that must be freed with a call
548 * to nfs_readdir_free_large_page
551 int nfs_readdir_large_page(struct page **pages, unsigned int npages)
555 for (i = 0; i < npages; i++) {
556 struct page *page = alloc_page(GFP_KERNEL);
564 nfs_readdir_free_pagearray(pages, i);
569 int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
571 struct page *pages[NFS_MAX_READDIR_PAGES];
572 void *pages_ptr = NULL;
573 struct nfs_entry entry;
574 struct file *file = desc->file;
575 struct nfs_cache_array *array;
576 int status = -ENOMEM;
577 unsigned int array_size = ARRAY_SIZE(pages);
579 entry.prev_cookie = 0;
580 entry.cookie = desc->last_cookie;
582 entry.fh = nfs_alloc_fhandle();
583 entry.fattr = nfs_alloc_fattr();
584 entry.server = NFS_SERVER(inode);
585 if (entry.fh == NULL || entry.fattr == NULL)
588 array = nfs_readdir_get_array(page);
590 status = PTR_ERR(array);
593 memset(array, 0, sizeof(struct nfs_cache_array));
594 array->eof_index = -1;
596 status = nfs_readdir_large_page(pages, array_size);
598 goto out_release_array;
601 status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
606 status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
608 if (status == -ENOSPC)
612 } while (array->eof_index < 0);
614 nfs_readdir_free_large_page(pages_ptr, pages, array_size);
616 nfs_readdir_release_array(page);
618 nfs_free_fattr(entry.fattr);
619 nfs_free_fhandle(entry.fh);
624 * Now we cache directories properly, by converting xdr information
625 * to an array that can be used for lookups later. This results in
626 * fewer cache pages, since we can store more information on each page.
627 * We only need to convert from xdr once so future lookups are much simpler
630 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
632 struct inode *inode = file_inode(desc->file);
635 ret = nfs_readdir_xdr_to_array(desc, page, inode);
638 SetPageUptodate(page);
640 if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
641 /* Should never happen */
642 nfs_zap_mapping(inode, inode->i_mapping);
652 void cache_page_release(nfs_readdir_descriptor_t *desc)
654 if (!desc->page->mapping)
655 nfs_readdir_clear_array(desc->page);
656 page_cache_release(desc->page);
661 struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
663 return read_cache_page(file_inode(desc->file)->i_mapping,
664 desc->page_index, (filler_t *)nfs_readdir_filler, desc);
668 * Returns 0 if desc->dir_cookie was found on page desc->page_index
671 int find_cache_page(nfs_readdir_descriptor_t *desc)
675 desc->page = get_cache_page(desc);
676 if (IS_ERR(desc->page))
677 return PTR_ERR(desc->page);
679 res = nfs_readdir_search_array(desc);
681 cache_page_release(desc);
685 /* Search for desc->dir_cookie from the beginning of the page cache */
687 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
691 if (desc->page_index == 0) {
692 desc->current_index = 0;
693 desc->last_cookie = 0;
696 res = find_cache_page(desc);
697 } while (res == -EAGAIN);
702 * Once we've found the start of the dirent within a page: fill 'er up...
705 int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
708 struct file *file = desc->file;
711 struct nfs_cache_array *array = NULL;
712 struct nfs_open_dir_context *ctx = file->private_data;
714 array = nfs_readdir_get_array(desc->page);
716 res = PTR_ERR(array);
720 for (i = desc->cache_entry_index; i < array->size; i++) {
721 struct nfs_cache_array_entry *ent;
723 ent = &array->array[i];
724 if (filldir(dirent, ent->string.name, ent->string.len,
725 file->f_pos, nfs_compat_user_ino64(ent->ino),
731 if (i < (array->size-1))
732 *desc->dir_cookie = array->array[i+1].cookie;
734 *desc->dir_cookie = array->last_cookie;
738 if (array->eof_index >= 0)
741 nfs_readdir_release_array(desc->page);
743 cache_page_release(desc);
744 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
745 (unsigned long long)*desc->dir_cookie, res);
750 * If we cannot find a cookie in our cache, we suspect that this is
751 * because it points to a deleted file, so we ask the server to return
752 * whatever it thinks is the next entry. We then feed this to filldir.
753 * If all goes well, we should then be able to find our way round the
754 * cache on the next call to readdir_search_pagecache();
756 * NOTE: we cannot add the anonymous page to the pagecache because
757 * the data it contains might not be page aligned. Besides,
758 * we should already have a complete representation of the
759 * directory in the page cache by the time we get here.
762 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
765 struct page *page = NULL;
767 struct inode *inode = file_inode(desc->file);
768 struct nfs_open_dir_context *ctx = desc->file->private_data;
770 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
771 (unsigned long long)*desc->dir_cookie);
773 page = alloc_page(GFP_HIGHUSER);
779 desc->page_index = 0;
780 desc->last_cookie = *desc->dir_cookie;
784 status = nfs_readdir_xdr_to_array(desc, page, inode);
788 status = nfs_do_filldir(desc, dirent, filldir);
791 dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
795 cache_page_release(desc);
799 /* The file offset position represents the dirent entry number. A
800 last cookie cache takes care of the common case of reading the
803 static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
805 struct dentry *dentry = filp->f_path.dentry;
806 struct inode *inode = dentry->d_inode;
807 nfs_readdir_descriptor_t my_desc,
809 struct nfs_open_dir_context *dir_ctx = filp->private_data;
812 dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
813 dentry->d_parent->d_name.name, dentry->d_name.name,
814 (long long)filp->f_pos);
815 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
818 * filp->f_pos points to the dirent entry number.
819 * *desc->dir_cookie has the cookie for the next entry. We have
820 * to either find the entry with the appropriate number or
821 * revalidate the cookie.
823 memset(desc, 0, sizeof(*desc));
826 desc->dir_cookie = &dir_ctx->dir_cookie;
827 desc->decode = NFS_PROTO(inode)->decode_dirent;
828 desc->plus = nfs_use_readdirplus(inode, filp) ? 1 : 0;
830 nfs_block_sillyrename(dentry);
831 res = nfs_revalidate_mapping(inode, filp->f_mapping);
836 res = readdir_search_pagecache(desc);
838 if (res == -EBADCOOKIE) {
840 /* This means either end of directory */
841 if (*desc->dir_cookie && desc->eof == 0) {
842 /* Or that the server has 'lost' a cookie */
843 res = uncached_readdir(desc, dirent, filldir);
849 if (res == -ETOOSMALL && desc->plus) {
850 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
851 nfs_zap_caches(inode);
852 desc->page_index = 0;
860 res = nfs_do_filldir(desc, dirent, filldir);
863 } while (!desc->eof);
865 nfs_unblock_sillyrename(dentry);
868 dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
869 dentry->d_parent->d_name.name, dentry->d_name.name,
874 static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
876 struct dentry *dentry = filp->f_path.dentry;
877 struct inode *inode = dentry->d_inode;
878 struct nfs_open_dir_context *dir_ctx = filp->private_data;
880 dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
881 dentry->d_parent->d_name.name,
885 mutex_lock(&inode->i_mutex);
888 offset += filp->f_pos;
896 if (offset != filp->f_pos) {
897 filp->f_pos = offset;
898 dir_ctx->dir_cookie = 0;
902 mutex_unlock(&inode->i_mutex);
907 * All directory operations under NFS are synchronous, so fsync()
908 * is a dummy operation.
910 static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
913 struct dentry *dentry = filp->f_path.dentry;
914 struct inode *inode = dentry->d_inode;
916 dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
917 dentry->d_parent->d_name.name, dentry->d_name.name,
920 mutex_lock(&inode->i_mutex);
921 nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
922 mutex_unlock(&inode->i_mutex);
927 * nfs_force_lookup_revalidate - Mark the directory as having changed
928 * @dir - pointer to directory inode
930 * This forces the revalidation code in nfs_lookup_revalidate() to do a
931 * full lookup on all child dentries of 'dir' whenever a change occurs
932 * on the server that might have invalidated our dcache.
934 * The caller should be holding dir->i_lock
936 void nfs_force_lookup_revalidate(struct inode *dir)
938 NFS_I(dir)->cache_change_attribute++;
940 EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
943 * A check for whether or not the parent directory has changed.
944 * In the case it has, we assume that the dentries are untrustworthy
945 * and may need to be looked up again.
947 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
951 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
953 if (!nfs_verify_change_attribute(dir, dentry->d_time))
955 /* Revalidate nfsi->cache_change_attribute before we declare a match */
956 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
958 if (!nfs_verify_change_attribute(dir, dentry->d_time))
964 * Use intent information to check whether or not we're going to do
965 * an O_EXCL create using this path component.
967 static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags)
969 if (NFS_PROTO(dir)->version == 2)
971 return flags & LOOKUP_EXCL;
975 * Inode and filehandle revalidation for lookups.
977 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
978 * or if the intent information indicates that we're about to open this
979 * particular file and the "nocto" mount flag is not set.
983 int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
985 struct nfs_server *server = NFS_SERVER(inode);
988 if (IS_AUTOMOUNT(inode))
990 /* VFS wants an on-the-wire revalidation */
991 if (flags & LOOKUP_REVAL)
993 /* This is an open(2) */
994 if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) &&
995 (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
998 return (inode->i_nlink == 0) ? -ENOENT : 0;
1000 ret = __nfs_revalidate_inode(server, inode);
1007 * We judge how long we want to trust negative
1008 * dentries by looking at the parent inode mtime.
1010 * If parent mtime has changed, we revalidate, else we wait for a
1011 * period corresponding to the parent's attribute cache timeout value.
1014 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
1017 /* Don't revalidate a negative dentry if we're creating a new file */
1018 if (flags & LOOKUP_CREATE)
1020 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
1022 return !nfs_check_verifier(dir, dentry);
1026 * This is called every time the dcache has a lookup hit,
1027 * and we should check whether we can really trust that
1030 * NOTE! The hit can be a negative hit too, don't assume
1033 * If the parent directory is seen to have changed, we throw out the
1034 * cached dentry and do a new lookup.
1036 static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
1039 struct inode *inode;
1040 struct dentry *parent;
1041 struct nfs_fh *fhandle = NULL;
1042 struct nfs_fattr *fattr = NULL;
1043 struct nfs4_label *label = NULL;
1046 if (flags & LOOKUP_RCU)
1049 parent = dget_parent(dentry);
1050 dir = parent->d_inode;
1051 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
1052 inode = dentry->d_inode;
1055 if (nfs_neg_need_reval(dir, dentry, flags))
1057 goto out_valid_noent;
1060 if (is_bad_inode(inode)) {
1061 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1062 __func__, dentry->d_parent->d_name.name,
1063 dentry->d_name.name);
1067 if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
1068 goto out_set_verifier;
1070 /* Force a full look up iff the parent directory has changed */
1071 if (!nfs_is_exclusive_create(dir, flags) && nfs_check_verifier(dir, dentry)) {
1072 if (nfs_lookup_verify_inode(inode, flags))
1073 goto out_zap_parent;
1077 if (NFS_STALE(inode))
1081 fhandle = nfs_alloc_fhandle();
1082 fattr = nfs_alloc_fattr();
1083 if (fhandle == NULL || fattr == NULL)
1086 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, label);
1089 if (nfs_compare_fh(NFS_FH(inode), fhandle))
1091 if ((error = nfs_refresh_inode(inode, fattr)) != 0)
1094 nfs_free_fattr(fattr);
1095 nfs_free_fhandle(fhandle);
1097 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1099 /* Success: notify readdir to use READDIRPLUS */
1100 nfs_advise_use_readdirplus(dir);
1103 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
1104 __func__, dentry->d_parent->d_name.name,
1105 dentry->d_name.name);
1108 nfs_zap_caches(dir);
1110 nfs_free_fattr(fattr);
1111 nfs_free_fhandle(fhandle);
1112 nfs_mark_for_revalidate(dir);
1113 if (inode && S_ISDIR(inode->i_mode)) {
1114 /* Purge readdir caches. */
1115 nfs_zap_caches(inode);
1116 /* If we have submounts, don't unhash ! */
1117 if (have_submounts(dentry))
1119 if (dentry->d_flags & DCACHE_DISCONNECTED)
1121 shrink_dcache_parent(dentry);
1125 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
1126 __func__, dentry->d_parent->d_name.name,
1127 dentry->d_name.name);
1130 nfs_free_fattr(fattr);
1131 nfs_free_fhandle(fhandle);
1133 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n",
1134 __func__, dentry->d_parent->d_name.name,
1135 dentry->d_name.name, error);
1140 * A weaker form of d_revalidate for revalidating just the dentry->d_inode
1141 * when we don't really care about the dentry name. This is called when a
1142 * pathwalk ends on a dentry that was not found via a normal lookup in the
1143 * parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals).
1145 * In this situation, we just want to verify that the inode itself is OK
1146 * since the dentry might have changed on the server.
1148 static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
1151 struct inode *inode = dentry->d_inode;
1154 * I believe we can only get a negative dentry here in the case of a
1155 * procfs-style symlink. Just assume it's correct for now, but we may
1156 * eventually need to do something more here.
1159 dfprintk(LOOKUPCACHE, "%s: %s/%s has negative inode\n",
1160 __func__, dentry->d_parent->d_name.name,
1161 dentry->d_name.name);
1165 if (is_bad_inode(inode)) {
1166 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1167 __func__, dentry->d_parent->d_name.name,
1168 dentry->d_name.name);
1172 error = nfs_revalidate_inode(NFS_SERVER(inode), inode);
1173 dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
1174 __func__, inode->i_ino, error ? "invalid" : "valid");
1179 * This is called from dput() when d_count is going to 0.
1181 static int nfs_dentry_delete(const struct dentry *dentry)
1183 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
1184 dentry->d_parent->d_name.name, dentry->d_name.name,
1187 /* Unhash any dentry with a stale inode */
1188 if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode))
1191 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1192 /* Unhash it, so that ->d_iput() would be called */
1195 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
1196 /* Unhash it, so that ancestors of killed async unlink
1197 * files will be cleaned up during umount */
1204 /* Ensure that we revalidate inode->i_nlink */
1205 static void nfs_drop_nlink(struct inode *inode)
1207 spin_lock(&inode->i_lock);
1208 /* drop the inode if we're reasonably sure this is the last link */
1209 if (inode->i_nlink == 1)
1211 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR;
1212 spin_unlock(&inode->i_lock);
1216 * Called when the dentry loses inode.
1217 * We use it to clean up silly-renamed files.
1219 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
1221 if (S_ISDIR(inode->i_mode))
1222 /* drop any readdir cache as it could easily be old */
1223 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
1225 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1226 nfs_complete_unlink(dentry, inode);
1227 nfs_drop_nlink(inode);
1232 static void nfs_d_release(struct dentry *dentry)
1234 /* free cached devname value, if it survived that far */
1235 if (unlikely(dentry->d_fsdata)) {
1236 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1239 kfree(dentry->d_fsdata);
1243 const struct dentry_operations nfs_dentry_operations = {
1244 .d_revalidate = nfs_lookup_revalidate,
1245 .d_weak_revalidate = nfs_weak_revalidate,
1246 .d_delete = nfs_dentry_delete,
1247 .d_iput = nfs_dentry_iput,
1248 .d_automount = nfs_d_automount,
1249 .d_release = nfs_d_release,
1251 EXPORT_SYMBOL_GPL(nfs_dentry_operations);
1253 struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
1256 struct dentry *parent;
1257 struct inode *inode = NULL;
1258 struct nfs_fh *fhandle = NULL;
1259 struct nfs_fattr *fattr = NULL;
1260 struct nfs4_label *label = NULL;
1263 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
1264 dentry->d_parent->d_name.name, dentry->d_name.name);
1265 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
1267 res = ERR_PTR(-ENAMETOOLONG);
1268 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
1272 * If we're doing an exclusive create, optimize away the lookup
1273 * but don't hash the dentry.
1275 if (nfs_is_exclusive_create(dir, flags)) {
1276 d_instantiate(dentry, NULL);
1281 res = ERR_PTR(-ENOMEM);
1282 fhandle = nfs_alloc_fhandle();
1283 fattr = nfs_alloc_fattr();
1284 if (fhandle == NULL || fattr == NULL)
1287 parent = dentry->d_parent;
1288 /* Protect against concurrent sillydeletes */
1289 nfs_block_sillyrename(parent);
1290 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, label);
1291 if (error == -ENOENT)
1294 res = ERR_PTR(error);
1295 goto out_unblock_sillyrename;
1297 inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
1298 res = ERR_CAST(inode);
1300 goto out_unblock_sillyrename;
1302 /* Success: notify readdir to use READDIRPLUS */
1303 nfs_advise_use_readdirplus(dir);
1306 res = d_materialise_unique(dentry, inode);
1309 goto out_unblock_sillyrename;
1312 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1313 out_unblock_sillyrename:
1314 nfs_unblock_sillyrename(parent);
1316 nfs_free_fattr(fattr);
1317 nfs_free_fhandle(fhandle);
1320 EXPORT_SYMBOL_GPL(nfs_lookup);
1322 #if IS_ENABLED(CONFIG_NFS_V4)
1323 static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
1325 const struct dentry_operations nfs4_dentry_operations = {
1326 .d_revalidate = nfs4_lookup_revalidate,
1327 .d_delete = nfs_dentry_delete,
1328 .d_iput = nfs_dentry_iput,
1329 .d_automount = nfs_d_automount,
1330 .d_release = nfs_d_release,
1332 EXPORT_SYMBOL_GPL(nfs4_dentry_operations);
1334 static fmode_t flags_to_mode(int flags)
1336 fmode_t res = (__force fmode_t)flags & FMODE_EXEC;
1337 if ((flags & O_ACCMODE) != O_WRONLY)
1339 if ((flags & O_ACCMODE) != O_RDONLY)
1344 static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags)
1346 return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
1349 static int do_open(struct inode *inode, struct file *filp)
1351 nfs_fscache_set_inode_cookie(inode, filp);
1355 static int nfs_finish_open(struct nfs_open_context *ctx,
1356 struct dentry *dentry,
1357 struct file *file, unsigned open_flags,
1362 if (ctx->dentry != dentry) {
1364 ctx->dentry = dget(dentry);
1367 /* If the open_intent is for execute, we have an extra check to make */
1368 if (ctx->mode & FMODE_EXEC) {
1369 err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags);
1374 err = finish_open(file, dentry, do_open, opened);
1377 nfs_file_set_open_context(file, ctx);
1380 put_nfs_open_context(ctx);
1384 int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
1385 struct file *file, unsigned open_flags,
1386 umode_t mode, int *opened)
1388 struct nfs_open_context *ctx;
1390 struct iattr attr = { .ia_valid = ATTR_OPEN };
1391 struct inode *inode;
1394 /* Expect a negative dentry */
1395 BUG_ON(dentry->d_inode);
1397 dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n",
1398 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1400 /* NFS only supports OPEN on regular files */
1401 if ((open_flags & O_DIRECTORY)) {
1402 if (!d_unhashed(dentry)) {
1404 * Hashed negative dentry with O_DIRECTORY: dentry was
1405 * revalidated and is fine, no need to perform lookup
1413 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
1414 return -ENAMETOOLONG;
1416 if (open_flags & O_CREAT) {
1417 attr.ia_valid |= ATTR_MODE;
1418 attr.ia_mode = mode & ~current_umask();
1420 if (open_flags & O_TRUNC) {
1421 attr.ia_valid |= ATTR_SIZE;
1425 ctx = create_nfs_open_context(dentry, open_flags);
1430 nfs_block_sillyrename(dentry->d_parent);
1431 inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
1433 if (IS_ERR(inode)) {
1434 nfs_unblock_sillyrename(dentry->d_parent);
1435 put_nfs_open_context(ctx);
1436 err = PTR_ERR(inode);
1439 d_add(dentry, NULL);
1445 if (!(open_flags & O_NOFOLLOW))
1454 res = d_add_unique(dentry, inode);
1458 nfs_unblock_sillyrename(dentry->d_parent);
1459 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1461 err = nfs_finish_open(ctx, dentry, file, open_flags, opened);
1468 res = nfs_lookup(dir, dentry, 0);
1473 return finish_no_open(file, res);
1475 EXPORT_SYMBOL_GPL(nfs_atomic_open);
1477 static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
1479 struct dentry *parent = NULL;
1480 struct inode *inode;
1484 if (flags & LOOKUP_RCU)
1487 if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
1489 if (d_mountpoint(dentry))
1491 if (NFS_SB(dentry->d_sb)->caps & NFS_CAP_ATOMIC_OPEN_V1)
1494 inode = dentry->d_inode;
1495 parent = dget_parent(dentry);
1496 dir = parent->d_inode;
1498 /* We can't create new files in nfs_open_revalidate(), so we
1499 * optimize away revalidation of negative dentries.
1501 if (inode == NULL) {
1502 if (!nfs_neg_need_reval(dir, dentry, flags))
1507 /* NFS only supports OPEN on regular files */
1508 if (!S_ISREG(inode->i_mode))
1510 /* We cannot do exclusive creation on a positive dentry */
1511 if (flags & LOOKUP_EXCL)
1514 /* Let f_op->open() actually open (and revalidate) the file */
1524 return nfs_lookup_revalidate(dentry, flags);
1527 #endif /* CONFIG_NFSV4 */
1530 * Code common to create, mkdir, and mknod.
1532 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1533 struct nfs_fattr *fattr,
1534 struct nfs4_label *label)
1536 struct dentry *parent = dget_parent(dentry);
1537 struct inode *dir = parent->d_inode;
1538 struct inode *inode;
1539 int error = -EACCES;
1543 /* We may have been initialized further down */
1544 if (dentry->d_inode)
1546 if (fhandle->size == 0) {
1547 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, NULL);
1551 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1552 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1553 struct nfs_server *server = NFS_SB(dentry->d_sb);
1554 error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr, NULL);
1558 inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
1559 error = PTR_ERR(inode);
1562 d_add(dentry, inode);
1567 nfs_mark_for_revalidate(dir);
1571 EXPORT_SYMBOL_GPL(nfs_instantiate);
1574 * Following a failed create operation, we drop the dentry rather
1575 * than retain a negative dentry. This avoids a problem in the event
1576 * that the operation succeeded on the server, but an error in the
1577 * reply path made it appear to have failed.
1579 int nfs_create(struct inode *dir, struct dentry *dentry,
1580 umode_t mode, bool excl)
1583 int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT;
1586 dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
1587 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1589 attr.ia_mode = mode;
1590 attr.ia_valid = ATTR_MODE;
1592 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
1600 EXPORT_SYMBOL_GPL(nfs_create);
1603 * See comments for nfs_proc_create regarding failed operations.
1606 nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1611 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
1612 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1614 if (!new_valid_dev(rdev))
1617 attr.ia_mode = mode;
1618 attr.ia_valid = ATTR_MODE;
1620 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
1628 EXPORT_SYMBOL_GPL(nfs_mknod);
1631 * See comments for nfs_proc_create regarding failed operations.
1633 int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
1638 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
1639 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1641 attr.ia_valid = ATTR_MODE;
1642 attr.ia_mode = mode | S_IFDIR;
1644 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
1652 EXPORT_SYMBOL_GPL(nfs_mkdir);
1654 static void nfs_dentry_handle_enoent(struct dentry *dentry)
1656 if (dentry->d_inode != NULL && !d_unhashed(dentry))
1660 int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1664 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
1665 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1667 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
1668 /* Ensure the VFS deletes this inode */
1669 if (error == 0 && dentry->d_inode != NULL)
1670 clear_nlink(dentry->d_inode);
1671 else if (error == -ENOENT)
1672 nfs_dentry_handle_enoent(dentry);
1676 EXPORT_SYMBOL_GPL(nfs_rmdir);
1679 * Remove a file after making sure there are no pending writes,
1680 * and after checking that the file has only one user.
1682 * We invalidate the attribute cache and free the inode prior to the operation
1683 * to avoid possible races if the server reuses the inode.
1685 static int nfs_safe_remove(struct dentry *dentry)
1687 struct inode *dir = dentry->d_parent->d_inode;
1688 struct inode *inode = dentry->d_inode;
1691 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1692 dentry->d_parent->d_name.name, dentry->d_name.name);
1694 /* If the dentry was sillyrenamed, we simply call d_delete() */
1695 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1700 if (inode != NULL) {
1701 NFS_PROTO(inode)->return_delegation(inode);
1702 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1704 nfs_drop_nlink(inode);
1706 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1707 if (error == -ENOENT)
1708 nfs_dentry_handle_enoent(dentry);
1713 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1714 * belongs to an active ".nfs..." file and we return -EBUSY.
1716 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1718 int nfs_unlink(struct inode *dir, struct dentry *dentry)
1721 int need_rehash = 0;
1723 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1724 dir->i_ino, dentry->d_name.name);
1726 spin_lock(&dentry->d_lock);
1727 if (dentry->d_count > 1) {
1728 spin_unlock(&dentry->d_lock);
1729 /* Start asynchronous writeout of the inode */
1730 write_inode_now(dentry->d_inode, 0);
1731 error = nfs_sillyrename(dir, dentry);
1734 if (!d_unhashed(dentry)) {
1738 spin_unlock(&dentry->d_lock);
1739 error = nfs_safe_remove(dentry);
1740 if (!error || error == -ENOENT) {
1741 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1742 } else if (need_rehash)
1746 EXPORT_SYMBOL_GPL(nfs_unlink);
1749 * To create a symbolic link, most file systems instantiate a new inode,
1750 * add a page to it containing the path, then write it out to the disk
1751 * using prepare_write/commit_write.
1753 * Unfortunately the NFS client can't create the in-core inode first
1754 * because it needs a file handle to create an in-core inode (see
1755 * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the
1756 * symlink request has completed on the server.
1758 * So instead we allocate a raw page, copy the symname into it, then do
1759 * the SYMLINK request with the page as the buffer. If it succeeds, we
1760 * now have a new file handle and can instantiate an in-core NFS inode
1761 * and move the raw page into its mapping.
1763 int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1765 struct pagevec lru_pvec;
1769 unsigned int pathlen = strlen(symname);
1772 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1773 dir->i_ino, dentry->d_name.name, symname);
1775 if (pathlen > PAGE_SIZE)
1776 return -ENAMETOOLONG;
1778 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1779 attr.ia_valid = ATTR_MODE;
1781 page = alloc_page(GFP_HIGHUSER);
1785 kaddr = kmap_atomic(page);
1786 memcpy(kaddr, symname, pathlen);
1787 if (pathlen < PAGE_SIZE)
1788 memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
1789 kunmap_atomic(kaddr);
1791 error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
1793 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n",
1794 dir->i_sb->s_id, dir->i_ino,
1795 dentry->d_name.name, symname, error);
1802 * No big deal if we can't add this page to the page cache here.
1803 * READLINK will get the missing page from the server if needed.
1805 pagevec_init(&lru_pvec, 0);
1806 if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0,
1808 pagevec_add(&lru_pvec, page);
1809 pagevec_lru_add_file(&lru_pvec);
1810 SetPageUptodate(page);
1817 EXPORT_SYMBOL_GPL(nfs_symlink);
1820 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1822 struct inode *inode = old_dentry->d_inode;
1825 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
1826 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1827 dentry->d_parent->d_name.name, dentry->d_name.name);
1829 NFS_PROTO(inode)->return_delegation(inode);
1832 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1835 d_add(dentry, inode);
1839 EXPORT_SYMBOL_GPL(nfs_link);
1843 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
1844 * different file handle for the same inode after a rename (e.g. when
1845 * moving to a different directory). A fail-safe method to do so would
1846 * be to look up old_dir/old_name, create a link to new_dir/new_name and
1847 * rename the old file using the sillyrename stuff. This way, the original
1848 * file in old_dir will go away when the last process iput()s the inode.
1852 * It actually works quite well. One needs to have the possibility for
1853 * at least one ".nfs..." file in each directory the file ever gets
1854 * moved or linked to which happens automagically with the new
1855 * implementation that only depends on the dcache stuff instead of
1856 * using the inode layer
1858 * Unfortunately, things are a little more complicated than indicated
1859 * above. For a cross-directory move, we want to make sure we can get
1860 * rid of the old inode after the operation. This means there must be
1861 * no pending writes (if it's a file), and the use count must be 1.
1862 * If these conditions are met, we can drop the dentries before doing
1865 int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1866 struct inode *new_dir, struct dentry *new_dentry)
1868 struct inode *old_inode = old_dentry->d_inode;
1869 struct inode *new_inode = new_dentry->d_inode;
1870 struct dentry *dentry = NULL, *rehash = NULL;
1873 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
1874 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1875 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
1876 new_dentry->d_count);
1879 * For non-directories, check whether the target is busy and if so,
1880 * make a copy of the dentry and then do a silly-rename. If the
1881 * silly-rename succeeds, the copied dentry is hashed and becomes
1884 if (new_inode && !S_ISDIR(new_inode->i_mode)) {
1886 * To prevent any new references to the target during the
1887 * rename, we unhash the dentry in advance.
1889 if (!d_unhashed(new_dentry)) {
1891 rehash = new_dentry;
1894 if (new_dentry->d_count > 2) {
1897 /* copy the target dentry's name */
1898 dentry = d_alloc(new_dentry->d_parent,
1899 &new_dentry->d_name);
1903 /* silly-rename the existing target ... */
1904 err = nfs_sillyrename(new_dir, new_dentry);
1908 new_dentry = dentry;
1914 NFS_PROTO(old_inode)->return_delegation(old_inode);
1915 if (new_inode != NULL)
1916 NFS_PROTO(new_inode)->return_delegation(new_inode);
1918 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
1919 new_dir, &new_dentry->d_name);
1920 nfs_mark_for_revalidate(old_inode);
1925 if (new_inode != NULL)
1926 nfs_drop_nlink(new_inode);
1927 d_move(old_dentry, new_dentry);
1928 nfs_set_verifier(new_dentry,
1929 nfs_save_change_attribute(new_dir));
1930 } else if (error == -ENOENT)
1931 nfs_dentry_handle_enoent(old_dentry);
1933 /* new dentry created? */
1938 EXPORT_SYMBOL_GPL(nfs_rename);
1940 static DEFINE_SPINLOCK(nfs_access_lru_lock);
1941 static LIST_HEAD(nfs_access_lru_list);
1942 static atomic_long_t nfs_access_nr_entries;
1944 static void nfs_access_free_entry(struct nfs_access_entry *entry)
1946 put_rpccred(entry->cred);
1948 smp_mb__before_atomic_dec();
1949 atomic_long_dec(&nfs_access_nr_entries);
1950 smp_mb__after_atomic_dec();
1953 static void nfs_access_free_list(struct list_head *head)
1955 struct nfs_access_entry *cache;
1957 while (!list_empty(head)) {
1958 cache = list_entry(head->next, struct nfs_access_entry, lru);
1959 list_del(&cache->lru);
1960 nfs_access_free_entry(cache);
1964 int nfs_access_cache_shrinker(struct shrinker *shrink,
1965 struct shrink_control *sc)
1968 struct nfs_inode *nfsi, *next;
1969 struct nfs_access_entry *cache;
1970 int nr_to_scan = sc->nr_to_scan;
1971 gfp_t gfp_mask = sc->gfp_mask;
1973 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
1974 return (nr_to_scan == 0) ? 0 : -1;
1976 spin_lock(&nfs_access_lru_lock);
1977 list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
1978 struct inode *inode;
1980 if (nr_to_scan-- == 0)
1982 inode = &nfsi->vfs_inode;
1983 spin_lock(&inode->i_lock);
1984 if (list_empty(&nfsi->access_cache_entry_lru))
1985 goto remove_lru_entry;
1986 cache = list_entry(nfsi->access_cache_entry_lru.next,
1987 struct nfs_access_entry, lru);
1988 list_move(&cache->lru, &head);
1989 rb_erase(&cache->rb_node, &nfsi->access_cache);
1990 if (!list_empty(&nfsi->access_cache_entry_lru))
1991 list_move_tail(&nfsi->access_cache_inode_lru,
1992 &nfs_access_lru_list);
1995 list_del_init(&nfsi->access_cache_inode_lru);
1996 smp_mb__before_clear_bit();
1997 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
1998 smp_mb__after_clear_bit();
2000 spin_unlock(&inode->i_lock);
2002 spin_unlock(&nfs_access_lru_lock);
2003 nfs_access_free_list(&head);
2004 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
2007 static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
2009 struct rb_root *root_node = &nfsi->access_cache;
2011 struct nfs_access_entry *entry;
2013 /* Unhook entries from the cache */
2014 while ((n = rb_first(root_node)) != NULL) {
2015 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2016 rb_erase(n, root_node);
2017 list_move(&entry->lru, head);
2019 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
2022 void nfs_access_zap_cache(struct inode *inode)
2026 if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
2028 /* Remove from global LRU init */
2029 spin_lock(&nfs_access_lru_lock);
2030 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2031 list_del_init(&NFS_I(inode)->access_cache_inode_lru);
2033 spin_lock(&inode->i_lock);
2034 __nfs_access_zap_cache(NFS_I(inode), &head);
2035 spin_unlock(&inode->i_lock);
2036 spin_unlock(&nfs_access_lru_lock);
2037 nfs_access_free_list(&head);
2039 EXPORT_SYMBOL_GPL(nfs_access_zap_cache);
2041 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
2043 struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
2044 struct nfs_access_entry *entry;
2047 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2049 if (cred < entry->cred)
2051 else if (cred > entry->cred)
2059 static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
2061 struct nfs_inode *nfsi = NFS_I(inode);
2062 struct nfs_access_entry *cache;
2065 spin_lock(&inode->i_lock);
2066 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
2068 cache = nfs_access_search_rbtree(inode, cred);
2071 if (!nfs_have_delegated_attributes(inode) &&
2072 !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
2074 res->jiffies = cache->jiffies;
2075 res->cred = cache->cred;
2076 res->mask = cache->mask;
2077 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2080 spin_unlock(&inode->i_lock);
2083 rb_erase(&cache->rb_node, &nfsi->access_cache);
2084 list_del(&cache->lru);
2085 spin_unlock(&inode->i_lock);
2086 nfs_access_free_entry(cache);
2089 spin_unlock(&inode->i_lock);
2090 nfs_access_zap_cache(inode);
2094 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
2096 struct nfs_inode *nfsi = NFS_I(inode);
2097 struct rb_root *root_node = &nfsi->access_cache;
2098 struct rb_node **p = &root_node->rb_node;
2099 struct rb_node *parent = NULL;
2100 struct nfs_access_entry *entry;
2102 spin_lock(&inode->i_lock);
2103 while (*p != NULL) {
2105 entry = rb_entry(parent, struct nfs_access_entry, rb_node);
2107 if (set->cred < entry->cred)
2108 p = &parent->rb_left;
2109 else if (set->cred > entry->cred)
2110 p = &parent->rb_right;
2114 rb_link_node(&set->rb_node, parent, p);
2115 rb_insert_color(&set->rb_node, root_node);
2116 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2117 spin_unlock(&inode->i_lock);
2120 rb_replace_node(parent, &set->rb_node, root_node);
2121 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2122 list_del(&entry->lru);
2123 spin_unlock(&inode->i_lock);
2124 nfs_access_free_entry(entry);
2127 void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2129 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
2132 RB_CLEAR_NODE(&cache->rb_node);
2133 cache->jiffies = set->jiffies;
2134 cache->cred = get_rpccred(set->cred);
2135 cache->mask = set->mask;
2137 nfs_access_add_rbtree(inode, cache);
2139 /* Update accounting */
2140 smp_mb__before_atomic_inc();
2141 atomic_long_inc(&nfs_access_nr_entries);
2142 smp_mb__after_atomic_inc();
2144 /* Add inode to global LRU list */
2145 if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2146 spin_lock(&nfs_access_lru_lock);
2147 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2148 list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
2149 &nfs_access_lru_list);
2150 spin_unlock(&nfs_access_lru_lock);
2153 EXPORT_SYMBOL_GPL(nfs_access_add_cache);
2155 void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result)
2158 if (access_result & NFS4_ACCESS_READ)
2159 entry->mask |= MAY_READ;
2161 (NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND | NFS4_ACCESS_DELETE))
2162 entry->mask |= MAY_WRITE;
2163 if (access_result & (NFS4_ACCESS_LOOKUP|NFS4_ACCESS_EXECUTE))
2164 entry->mask |= MAY_EXEC;
2166 EXPORT_SYMBOL_GPL(nfs_access_set_mask);
2168 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
2170 struct nfs_access_entry cache;
2173 status = nfs_access_get_cached(inode, cred, &cache);
2177 /* Be clever: ask server to check for all possible rights */
2178 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
2180 cache.jiffies = jiffies;
2181 status = NFS_PROTO(inode)->access(inode, &cache);
2183 if (status == -ESTALE) {
2184 nfs_zap_caches(inode);
2185 if (!S_ISDIR(inode->i_mode))
2186 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
2190 nfs_access_add_cache(inode, &cache);
2192 if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2197 static int nfs_open_permission_mask(int openflags)
2201 if (openflags & __FMODE_EXEC) {
2202 /* ONLY check exec rights */
2205 if ((openflags & O_ACCMODE) != O_WRONLY)
2207 if ((openflags & O_ACCMODE) != O_RDONLY)
2214 int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
2216 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
2218 EXPORT_SYMBOL_GPL(nfs_may_open);
2220 int nfs_permission(struct inode *inode, int mask)
2222 struct rpc_cred *cred;
2225 if (mask & MAY_NOT_BLOCK)
2228 nfs_inc_stats(inode, NFSIOS_VFSACCESS);
2230 if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2232 /* Is this sys_access() ? */
2233 if (mask & (MAY_ACCESS | MAY_CHDIR))
2236 switch (inode->i_mode & S_IFMT) {
2240 /* NFSv4 has atomic_open... */
2241 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
2242 && (mask & MAY_OPEN)
2243 && !(mask & MAY_EXEC))
2248 * Optimize away all write operations, since the server
2249 * will check permissions when we perform the op.
2251 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
2256 if (!NFS_PROTO(inode)->access)
2259 cred = rpc_lookup_cred();
2260 if (!IS_ERR(cred)) {
2261 res = nfs_do_access(inode, cred, mask);
2264 res = PTR_ERR(cred);
2266 if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
2269 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
2270 inode->i_sb->s_id, inode->i_ino, mask, res);
2273 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
2275 res = generic_permission(inode, mask);
2278 EXPORT_SYMBOL_GPL(nfs_permission);
2282 * version-control: t
2283 * kept-new-versions: 5