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/swap.h>
37 #include <linux/sched.h>
38 #include <linux/kmemleak.h>
39 #include <linux/xattr.h>
41 #include "delegation.h"
46 /* #define NFS_DEBUG_VERBOSE 1 */
48 static int nfs_opendir(struct inode *, struct file *);
49 static int nfs_closedir(struct inode *, struct file *);
50 static int nfs_readdir(struct file *, struct dir_context *);
51 static int nfs_fsync_dir(struct file *, loff_t, loff_t, int);
52 static loff_t nfs_llseek_dir(struct file *, loff_t, int);
53 static void nfs_readdir_clear_array(struct page*);
55 const struct file_operations nfs_dir_operations = {
56 .llseek = nfs_llseek_dir,
57 .read = generic_read_dir,
58 .iterate = nfs_readdir,
60 .release = nfs_closedir,
61 .fsync = nfs_fsync_dir,
64 const struct address_space_operations nfs_dir_aops = {
65 .freepage = nfs_readdir_clear_array,
68 static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred)
70 struct nfs_open_dir_context *ctx;
71 ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
74 ctx->attr_gencount = NFS_I(dir)->attr_gencount;
77 ctx->cred = get_rpccred(cred);
80 return ERR_PTR(-ENOMEM);
83 static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
85 put_rpccred(ctx->cred);
93 nfs_opendir(struct inode *inode, struct file *filp)
96 struct nfs_open_dir_context *ctx;
97 struct rpc_cred *cred;
99 dfprintk(FILE, "NFS: open dir(%s/%s)\n",
100 filp->f_path.dentry->d_parent->d_name.name,
101 filp->f_path.dentry->d_name.name);
103 nfs_inc_stats(inode, NFSIOS_VFSOPEN);
105 cred = rpc_lookup_cred();
107 return PTR_ERR(cred);
108 ctx = alloc_nfs_open_dir_context(inode, cred);
113 filp->private_data = ctx;
114 if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
115 /* This is a mountpoint, so d_revalidate will never
116 * have been called, so we need to refresh the
117 * inode (for close-open consistency) ourselves.
119 __nfs_revalidate_inode(NFS_SERVER(inode), inode);
127 nfs_closedir(struct inode *inode, struct file *filp)
129 put_nfs_open_dir_context(filp->private_data);
133 struct nfs_cache_array_entry {
137 unsigned char d_type;
140 struct nfs_cache_array {
144 struct nfs_cache_array_entry array[0];
147 typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int);
151 struct dir_context *ctx;
152 unsigned long page_index;
155 loff_t current_index;
156 decode_dirent_t decode;
158 unsigned long timestamp;
159 unsigned long gencount;
160 unsigned int cache_entry_index;
163 } nfs_readdir_descriptor_t;
166 * The caller is responsible for calling nfs_readdir_release_array(page)
169 struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
173 return ERR_PTR(-EIO);
176 return ERR_PTR(-ENOMEM);
181 void nfs_readdir_release_array(struct page *page)
187 * we are freeing strings created by nfs_add_to_readdir_array()
190 void nfs_readdir_clear_array(struct page *page)
192 struct nfs_cache_array *array;
195 array = kmap_atomic(page);
196 for (i = 0; i < array->size; i++)
197 kfree(array->array[i].string.name);
198 kunmap_atomic(array);
202 * the caller is responsible for freeing qstr.name
203 * when called by nfs_readdir_add_to_array, the strings will be freed in
204 * nfs_clear_readdir_array()
207 int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len)
210 string->name = kmemdup(name, len, GFP_KERNEL);
211 if (string->name == NULL)
214 * Avoid a kmemleak false positive. The pointer to the name is stored
215 * in a page cache page which kmemleak does not scan.
217 kmemleak_not_leak(string->name);
218 string->hash = full_name_hash(name, len);
223 int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
225 struct nfs_cache_array *array = nfs_readdir_get_array(page);
226 struct nfs_cache_array_entry *cache_entry;
230 return PTR_ERR(array);
232 cache_entry = &array->array[array->size];
234 /* Check that this entry lies within the page bounds */
236 if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE)
239 cache_entry->cookie = entry->prev_cookie;
240 cache_entry->ino = entry->ino;
241 cache_entry->d_type = entry->d_type;
242 ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len);
245 array->last_cookie = entry->cookie;
248 array->eof_index = array->size;
250 nfs_readdir_release_array(page);
255 int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
257 loff_t diff = desc->ctx->pos - desc->current_index;
262 if (diff >= array->size) {
263 if (array->eof_index >= 0)
268 index = (unsigned int)diff;
269 *desc->dir_cookie = array->array[index].cookie;
270 desc->cache_entry_index = index;
278 int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
282 int status = -EAGAIN;
284 for (i = 0; i < array->size; i++) {
285 if (array->array[i].cookie == *desc->dir_cookie) {
286 struct nfs_inode *nfsi = NFS_I(file_inode(desc->file));
287 struct nfs_open_dir_context *ctx = desc->file->private_data;
289 new_pos = desc->current_index + i;
290 if (ctx->attr_gencount != nfsi->attr_gencount
291 || (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))) {
293 ctx->attr_gencount = nfsi->attr_gencount;
294 } else if (new_pos < desc->ctx->pos) {
296 && ctx->dup_cookie == *desc->dir_cookie) {
297 if (printk_ratelimit()) {
298 pr_notice("NFS: directory %s/%s contains a readdir loop."
299 "Please contact your server vendor. "
300 "The file: %s has duplicate cookie %llu\n",
301 desc->file->f_dentry->d_parent->d_name.name,
302 desc->file->f_dentry->d_name.name,
303 array->array[i].string.name,
309 ctx->dup_cookie = *desc->dir_cookie;
312 desc->ctx->pos = new_pos;
313 desc->cache_entry_index = i;
317 if (array->eof_index >= 0) {
318 status = -EBADCOOKIE;
319 if (*desc->dir_cookie == array->last_cookie)
327 int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
329 struct nfs_cache_array *array;
332 array = nfs_readdir_get_array(desc->page);
334 status = PTR_ERR(array);
338 if (*desc->dir_cookie == 0)
339 status = nfs_readdir_search_for_pos(array, desc);
341 status = nfs_readdir_search_for_cookie(array, desc);
343 if (status == -EAGAIN) {
344 desc->last_cookie = array->last_cookie;
345 desc->current_index += array->size;
348 nfs_readdir_release_array(desc->page);
353 /* Fill a page with xdr information before transferring to the cache page */
355 int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
356 struct nfs_entry *entry, struct file *file, struct inode *inode)
358 struct nfs_open_dir_context *ctx = file->private_data;
359 struct rpc_cred *cred = ctx->cred;
360 unsigned long timestamp, gencount;
365 gencount = nfs_inc_attr_generation_counter();
366 error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages,
367 NFS_SERVER(inode)->dtsize, desc->plus);
369 /* We requested READDIRPLUS, but the server doesn't grok it */
370 if (error == -ENOTSUPP && desc->plus) {
371 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
372 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
378 desc->timestamp = timestamp;
379 desc->gencount = gencount;
384 static int xdr_decode(nfs_readdir_descriptor_t *desc,
385 struct nfs_entry *entry, struct xdr_stream *xdr)
389 error = desc->decode(xdr, entry, desc->plus);
392 entry->fattr->time_start = desc->timestamp;
393 entry->fattr->gencount = desc->gencount;
398 int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry)
400 if (dentry->d_inode == NULL)
402 if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0)
410 bool nfs_use_readdirplus(struct inode *dir, struct dir_context *ctx)
412 if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS))
414 if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags))
422 * This function is called by the lookup code to request the use of
423 * readdirplus to accelerate any future lookups in the same
427 void nfs_advise_use_readdirplus(struct inode *dir)
429 set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags);
433 void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry)
435 struct qstr filename = QSTR_INIT(entry->name, entry->len);
436 struct dentry *dentry;
437 struct dentry *alias;
438 struct inode *dir = parent->d_inode;
442 if (filename.name[0] == '.') {
443 if (filename.len == 1)
445 if (filename.len == 2 && filename.name[1] == '.')
448 filename.hash = full_name_hash(filename.name, filename.len);
450 dentry = d_lookup(parent, &filename);
451 if (dentry != NULL) {
452 if (nfs_same_file(dentry, entry)) {
453 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
454 status = nfs_refresh_inode(dentry->d_inode, entry->fattr);
456 nfs_setsecurity(dentry->d_inode, entry->fattr, entry->label);
459 if (d_invalidate(dentry) != 0)
465 dentry = d_alloc(parent, &filename);
469 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr, entry->label);
473 alias = d_materialise_unique(dentry, inode);
477 nfs_set_verifier(alias, nfs_save_change_attribute(dir));
480 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
486 /* Perform conversion from xdr to cache array */
488 int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry,
489 struct page **xdr_pages, struct page *page, unsigned int buflen)
491 struct xdr_stream stream;
493 struct page *scratch;
494 struct nfs_cache_array *array;
495 unsigned int count = 0;
498 scratch = alloc_page(GFP_KERNEL);
502 xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen);
503 xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE);
506 status = xdr_decode(desc, entry, &stream);
508 if (status == -EAGAIN)
516 nfs_prime_dcache(desc->file->f_path.dentry, entry);
518 status = nfs_readdir_add_to_array(entry, page);
521 } while (!entry->eof);
523 if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
524 array = nfs_readdir_get_array(page);
525 if (!IS_ERR(array)) {
526 array->eof_index = array->size;
528 nfs_readdir_release_array(page);
530 status = PTR_ERR(array);
538 void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages)
541 for (i = 0; i < npages; i++)
546 void nfs_readdir_free_large_page(void *ptr, struct page **pages,
549 nfs_readdir_free_pagearray(pages, npages);
553 * nfs_readdir_large_page will allocate pages that must be freed with a call
554 * to nfs_readdir_free_large_page
557 int nfs_readdir_large_page(struct page **pages, unsigned int npages)
561 for (i = 0; i < npages; i++) {
562 struct page *page = alloc_page(GFP_KERNEL);
570 nfs_readdir_free_pagearray(pages, i);
575 int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode)
577 struct page *pages[NFS_MAX_READDIR_PAGES];
578 void *pages_ptr = NULL;
579 struct nfs_entry entry;
580 struct file *file = desc->file;
581 struct nfs_cache_array *array;
582 int status = -ENOMEM;
583 unsigned int array_size = ARRAY_SIZE(pages);
585 entry.prev_cookie = 0;
586 entry.cookie = desc->last_cookie;
588 entry.fh = nfs_alloc_fhandle();
589 entry.fattr = nfs_alloc_fattr();
590 entry.server = NFS_SERVER(inode);
591 if (entry.fh == NULL || entry.fattr == NULL)
594 entry.label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
595 if (IS_ERR(entry.label)) {
596 status = PTR_ERR(entry.label);
600 array = nfs_readdir_get_array(page);
602 status = PTR_ERR(array);
605 memset(array, 0, sizeof(struct nfs_cache_array));
606 array->eof_index = -1;
608 status = nfs_readdir_large_page(pages, array_size);
610 goto out_release_array;
613 status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode);
618 status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen);
620 if (status == -ENOSPC)
624 } while (array->eof_index < 0);
626 nfs_readdir_free_large_page(pages_ptr, pages, array_size);
628 nfs_readdir_release_array(page);
630 nfs4_label_free(entry.label);
632 nfs_free_fattr(entry.fattr);
633 nfs_free_fhandle(entry.fh);
638 * Now we cache directories properly, by converting xdr information
639 * to an array that can be used for lookups later. This results in
640 * fewer cache pages, since we can store more information on each page.
641 * We only need to convert from xdr once so future lookups are much simpler
644 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
646 struct inode *inode = file_inode(desc->file);
649 ret = nfs_readdir_xdr_to_array(desc, page, inode);
652 SetPageUptodate(page);
654 if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) {
655 /* Should never happen */
656 nfs_zap_mapping(inode, inode->i_mapping);
666 void cache_page_release(nfs_readdir_descriptor_t *desc)
668 if (!desc->page->mapping)
669 nfs_readdir_clear_array(desc->page);
670 page_cache_release(desc->page);
675 struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
677 return read_cache_page(file_inode(desc->file)->i_mapping,
678 desc->page_index, (filler_t *)nfs_readdir_filler, desc);
682 * Returns 0 if desc->dir_cookie was found on page desc->page_index
685 int find_cache_page(nfs_readdir_descriptor_t *desc)
689 desc->page = get_cache_page(desc);
690 if (IS_ERR(desc->page))
691 return PTR_ERR(desc->page);
693 res = nfs_readdir_search_array(desc);
695 cache_page_release(desc);
699 /* Search for desc->dir_cookie from the beginning of the page cache */
701 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
705 if (desc->page_index == 0) {
706 desc->current_index = 0;
707 desc->last_cookie = 0;
710 res = find_cache_page(desc);
711 } while (res == -EAGAIN);
716 * Once we've found the start of the dirent within a page: fill 'er up...
719 int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
721 struct file *file = desc->file;
724 struct nfs_cache_array *array = NULL;
725 struct nfs_open_dir_context *ctx = file->private_data;
727 array = nfs_readdir_get_array(desc->page);
729 res = PTR_ERR(array);
733 for (i = desc->cache_entry_index; i < array->size; i++) {
734 struct nfs_cache_array_entry *ent;
736 ent = &array->array[i];
737 if (!dir_emit(desc->ctx, ent->string.name, ent->string.len,
738 nfs_compat_user_ino64(ent->ino), ent->d_type)) {
743 if (i < (array->size-1))
744 *desc->dir_cookie = array->array[i+1].cookie;
746 *desc->dir_cookie = array->last_cookie;
750 if (array->eof_index >= 0)
753 nfs_readdir_release_array(desc->page);
755 cache_page_release(desc);
756 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
757 (unsigned long long)*desc->dir_cookie, res);
762 * If we cannot find a cookie in our cache, we suspect that this is
763 * because it points to a deleted file, so we ask the server to return
764 * whatever it thinks is the next entry. We then feed this to filldir.
765 * If all goes well, we should then be able to find our way round the
766 * cache on the next call to readdir_search_pagecache();
768 * NOTE: we cannot add the anonymous page to the pagecache because
769 * the data it contains might not be page aligned. Besides,
770 * we should already have a complete representation of the
771 * directory in the page cache by the time we get here.
774 int uncached_readdir(nfs_readdir_descriptor_t *desc)
776 struct page *page = NULL;
778 struct inode *inode = file_inode(desc->file);
779 struct nfs_open_dir_context *ctx = desc->file->private_data;
781 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
782 (unsigned long long)*desc->dir_cookie);
784 page = alloc_page(GFP_HIGHUSER);
790 desc->page_index = 0;
791 desc->last_cookie = *desc->dir_cookie;
795 status = nfs_readdir_xdr_to_array(desc, page, inode);
799 status = nfs_do_filldir(desc);
802 dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
806 cache_page_release(desc);
810 /* The file offset position represents the dirent entry number. A
811 last cookie cache takes care of the common case of reading the
814 static int nfs_readdir(struct file *file, struct dir_context *ctx)
816 struct dentry *dentry = file->f_path.dentry;
817 struct inode *inode = dentry->d_inode;
818 nfs_readdir_descriptor_t my_desc,
820 struct nfs_open_dir_context *dir_ctx = file->private_data;
823 dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
824 dentry->d_parent->d_name.name, dentry->d_name.name,
825 (long long)ctx->pos);
826 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
829 * ctx->pos points to the dirent entry number.
830 * *desc->dir_cookie has the cookie for the next entry. We have
831 * to either find the entry with the appropriate number or
832 * revalidate the cookie.
834 memset(desc, 0, sizeof(*desc));
838 desc->dir_cookie = &dir_ctx->dir_cookie;
839 desc->decode = NFS_PROTO(inode)->decode_dirent;
840 desc->plus = nfs_use_readdirplus(inode, ctx) ? 1 : 0;
842 nfs_block_sillyrename(dentry);
843 if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
844 res = nfs_revalidate_mapping(inode, file->f_mapping);
849 res = readdir_search_pagecache(desc);
851 if (res == -EBADCOOKIE) {
853 /* This means either end of directory */
854 if (*desc->dir_cookie && desc->eof == 0) {
855 /* Or that the server has 'lost' a cookie */
856 res = uncached_readdir(desc);
862 if (res == -ETOOSMALL && desc->plus) {
863 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags);
864 nfs_zap_caches(inode);
865 desc->page_index = 0;
873 res = nfs_do_filldir(desc);
876 } while (!desc->eof);
878 nfs_unblock_sillyrename(dentry);
881 dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n",
882 dentry->d_parent->d_name.name, dentry->d_name.name,
887 static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
889 struct dentry *dentry = filp->f_path.dentry;
890 struct inode *inode = dentry->d_inode;
891 struct nfs_open_dir_context *dir_ctx = filp->private_data;
893 dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
894 dentry->d_parent->d_name.name,
898 mutex_lock(&inode->i_mutex);
901 offset += filp->f_pos;
909 if (offset != filp->f_pos) {
910 filp->f_pos = offset;
911 dir_ctx->dir_cookie = 0;
915 mutex_unlock(&inode->i_mutex);
920 * All directory operations under NFS are synchronous, so fsync()
921 * is a dummy operation.
923 static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end,
926 struct dentry *dentry = filp->f_path.dentry;
927 struct inode *inode = dentry->d_inode;
929 dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n",
930 dentry->d_parent->d_name.name, dentry->d_name.name,
933 mutex_lock(&inode->i_mutex);
934 nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC);
935 mutex_unlock(&inode->i_mutex);
940 * nfs_force_lookup_revalidate - Mark the directory as having changed
941 * @dir - pointer to directory inode
943 * This forces the revalidation code in nfs_lookup_revalidate() to do a
944 * full lookup on all child dentries of 'dir' whenever a change occurs
945 * on the server that might have invalidated our dcache.
947 * The caller should be holding dir->i_lock
949 void nfs_force_lookup_revalidate(struct inode *dir)
951 NFS_I(dir)->cache_change_attribute++;
953 EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate);
956 * A check for whether or not the parent directory has changed.
957 * In the case it has, we assume that the dentries are untrustworthy
958 * and may need to be looked up again.
960 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
964 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE)
966 if (!nfs_verify_change_attribute(dir, dentry->d_time))
968 /* Revalidate nfsi->cache_change_attribute before we declare a match */
969 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
971 if (!nfs_verify_change_attribute(dir, dentry->d_time))
977 * Use intent information to check whether or not we're going to do
978 * an O_EXCL create using this path component.
980 static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags)
982 if (NFS_PROTO(dir)->version == 2)
984 return flags & LOOKUP_EXCL;
988 * Inode and filehandle revalidation for lookups.
990 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
991 * or if the intent information indicates that we're about to open this
992 * particular file and the "nocto" mount flag is not set.
996 int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags)
998 struct nfs_server *server = NFS_SERVER(inode);
1001 if (IS_AUTOMOUNT(inode))
1003 /* VFS wants an on-the-wire revalidation */
1004 if (flags & LOOKUP_REVAL)
1006 /* This is an open(2) */
1007 if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) &&
1008 (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)))
1011 return (inode->i_nlink == 0) ? -ENOENT : 0;
1013 ret = __nfs_revalidate_inode(server, inode);
1020 * We judge how long we want to trust negative
1021 * dentries by looking at the parent inode mtime.
1023 * If parent mtime has changed, we revalidate, else we wait for a
1024 * period corresponding to the parent's attribute cache timeout value.
1027 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
1030 /* Don't revalidate a negative dentry if we're creating a new file */
1031 if (flags & LOOKUP_CREATE)
1033 if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG)
1035 return !nfs_check_verifier(dir, dentry);
1039 * This is called every time the dcache has a lookup hit,
1040 * and we should check whether we can really trust that
1043 * NOTE! The hit can be a negative hit too, don't assume
1046 * If the parent directory is seen to have changed, we throw out the
1047 * cached dentry and do a new lookup.
1049 static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
1052 struct inode *inode;
1053 struct dentry *parent;
1054 struct nfs_fh *fhandle = NULL;
1055 struct nfs_fattr *fattr = NULL;
1056 struct nfs4_label *label = NULL;
1059 if (flags & LOOKUP_RCU)
1062 parent = dget_parent(dentry);
1063 dir = parent->d_inode;
1064 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
1065 inode = dentry->d_inode;
1068 if (nfs_neg_need_reval(dir, dentry, flags))
1070 goto out_valid_noent;
1073 if (is_bad_inode(inode)) {
1074 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1075 __func__, dentry->d_parent->d_name.name,
1076 dentry->d_name.name);
1080 if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ))
1081 goto out_set_verifier;
1083 /* Force a full look up iff the parent directory has changed */
1084 if (!nfs_is_exclusive_create(dir, flags) && nfs_check_verifier(dir, dentry)) {
1085 if (nfs_lookup_verify_inode(inode, flags))
1086 goto out_zap_parent;
1090 if (NFS_STALE(inode))
1094 fhandle = nfs_alloc_fhandle();
1095 fattr = nfs_alloc_fattr();
1096 if (fhandle == NULL || fattr == NULL)
1099 label = nfs4_label_alloc(NFS_SERVER(inode), GFP_NOWAIT);
1103 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, label);
1106 if (nfs_compare_fh(NFS_FH(inode), fhandle))
1108 if ((error = nfs_refresh_inode(inode, fattr)) != 0)
1111 nfs_setsecurity(inode, fattr, label);
1113 nfs_free_fattr(fattr);
1114 nfs_free_fhandle(fhandle);
1115 nfs4_label_free(label);
1118 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1120 /* Success: notify readdir to use READDIRPLUS */
1121 nfs_advise_use_readdirplus(dir);
1124 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
1125 __func__, dentry->d_parent->d_name.name,
1126 dentry->d_name.name);
1129 nfs_zap_caches(dir);
1131 nfs_free_fattr(fattr);
1132 nfs_free_fhandle(fhandle);
1133 nfs4_label_free(label);
1134 nfs_mark_for_revalidate(dir);
1135 if (inode && S_ISDIR(inode->i_mode)) {
1136 /* Purge readdir caches. */
1137 nfs_zap_caches(inode);
1138 if (dentry->d_flags & DCACHE_DISCONNECTED)
1141 /* If we have submounts, don't unhash ! */
1142 if (check_submounts_and_drop(dentry) != 0)
1146 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
1147 __func__, dentry->d_parent->d_name.name,
1148 dentry->d_name.name);
1151 nfs_free_fattr(fattr);
1152 nfs_free_fhandle(fhandle);
1153 nfs4_label_free(label);
1155 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n",
1156 __func__, dentry->d_parent->d_name.name,
1157 dentry->d_name.name, error);
1162 * A weaker form of d_revalidate for revalidating just the dentry->d_inode
1163 * when we don't really care about the dentry name. This is called when a
1164 * pathwalk ends on a dentry that was not found via a normal lookup in the
1165 * parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals).
1167 * In this situation, we just want to verify that the inode itself is OK
1168 * since the dentry might have changed on the server.
1170 static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
1173 struct inode *inode = dentry->d_inode;
1176 * I believe we can only get a negative dentry here in the case of a
1177 * procfs-style symlink. Just assume it's correct for now, but we may
1178 * eventually need to do something more here.
1181 dfprintk(LOOKUPCACHE, "%s: %s/%s has negative inode\n",
1182 __func__, dentry->d_parent->d_name.name,
1183 dentry->d_name.name);
1187 if (is_bad_inode(inode)) {
1188 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
1189 __func__, dentry->d_parent->d_name.name,
1190 dentry->d_name.name);
1194 error = nfs_revalidate_inode(NFS_SERVER(inode), inode);
1195 dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
1196 __func__, inode->i_ino, error ? "invalid" : "valid");
1201 * This is called from dput() when d_count is going to 0.
1203 static int nfs_dentry_delete(const struct dentry *dentry)
1205 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
1206 dentry->d_parent->d_name.name, dentry->d_name.name,
1209 /* Unhash any dentry with a stale inode */
1210 if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode))
1213 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1214 /* Unhash it, so that ->d_iput() would be called */
1217 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
1218 /* Unhash it, so that ancestors of killed async unlink
1219 * files will be cleaned up during umount */
1226 /* Ensure that we revalidate inode->i_nlink */
1227 static void nfs_drop_nlink(struct inode *inode)
1229 spin_lock(&inode->i_lock);
1230 /* drop the inode if we're reasonably sure this is the last link */
1231 if (inode->i_nlink == 1)
1233 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR;
1234 spin_unlock(&inode->i_lock);
1238 * Called when the dentry loses inode.
1239 * We use it to clean up silly-renamed files.
1241 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
1243 if (S_ISDIR(inode->i_mode))
1244 /* drop any readdir cache as it could easily be old */
1245 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
1247 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1248 nfs_complete_unlink(dentry, inode);
1249 nfs_drop_nlink(inode);
1254 static void nfs_d_release(struct dentry *dentry)
1256 /* free cached devname value, if it survived that far */
1257 if (unlikely(dentry->d_fsdata)) {
1258 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1261 kfree(dentry->d_fsdata);
1265 const struct dentry_operations nfs_dentry_operations = {
1266 .d_revalidate = nfs_lookup_revalidate,
1267 .d_weak_revalidate = nfs_weak_revalidate,
1268 .d_delete = nfs_dentry_delete,
1269 .d_iput = nfs_dentry_iput,
1270 .d_automount = nfs_d_automount,
1271 .d_release = nfs_d_release,
1273 EXPORT_SYMBOL_GPL(nfs_dentry_operations);
1275 struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
1278 struct dentry *parent;
1279 struct inode *inode = NULL;
1280 struct nfs_fh *fhandle = NULL;
1281 struct nfs_fattr *fattr = NULL;
1282 struct nfs4_label *label = NULL;
1285 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
1286 dentry->d_parent->d_name.name, dentry->d_name.name);
1287 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
1289 res = ERR_PTR(-ENAMETOOLONG);
1290 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
1294 * If we're doing an exclusive create, optimize away the lookup
1295 * but don't hash the dentry.
1297 if (nfs_is_exclusive_create(dir, flags)) {
1298 d_instantiate(dentry, NULL);
1303 res = ERR_PTR(-ENOMEM);
1304 fhandle = nfs_alloc_fhandle();
1305 fattr = nfs_alloc_fattr();
1306 if (fhandle == NULL || fattr == NULL)
1309 label = nfs4_label_alloc(NFS_SERVER(dir), GFP_NOWAIT);
1313 parent = dentry->d_parent;
1314 /* Protect against concurrent sillydeletes */
1315 nfs_block_sillyrename(parent);
1316 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, label);
1317 if (error == -ENOENT)
1320 res = ERR_PTR(error);
1321 goto out_unblock_sillyrename;
1323 inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
1324 res = ERR_CAST(inode);
1326 goto out_unblock_sillyrename;
1328 /* Success: notify readdir to use READDIRPLUS */
1329 nfs_advise_use_readdirplus(dir);
1332 res = d_materialise_unique(dentry, inode);
1335 goto out_unblock_sillyrename;
1338 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1339 out_unblock_sillyrename:
1340 nfs_unblock_sillyrename(parent);
1341 nfs4_label_free(label);
1343 nfs_free_fattr(fattr);
1344 nfs_free_fhandle(fhandle);
1347 EXPORT_SYMBOL_GPL(nfs_lookup);
1349 #if IS_ENABLED(CONFIG_NFS_V4)
1350 static int nfs4_lookup_revalidate(struct dentry *, unsigned int);
1352 const struct dentry_operations nfs4_dentry_operations = {
1353 .d_revalidate = nfs4_lookup_revalidate,
1354 .d_delete = nfs_dentry_delete,
1355 .d_iput = nfs_dentry_iput,
1356 .d_automount = nfs_d_automount,
1357 .d_release = nfs_d_release,
1359 EXPORT_SYMBOL_GPL(nfs4_dentry_operations);
1361 static fmode_t flags_to_mode(int flags)
1363 fmode_t res = (__force fmode_t)flags & FMODE_EXEC;
1364 if ((flags & O_ACCMODE) != O_WRONLY)
1366 if ((flags & O_ACCMODE) != O_RDONLY)
1371 static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags)
1373 return alloc_nfs_open_context(dentry, flags_to_mode(open_flags));
1376 static int do_open(struct inode *inode, struct file *filp)
1378 nfs_fscache_set_inode_cookie(inode, filp);
1382 static int nfs_finish_open(struct nfs_open_context *ctx,
1383 struct dentry *dentry,
1384 struct file *file, unsigned open_flags,
1389 err = finish_open(file, dentry, do_open, opened);
1392 nfs_file_set_open_context(file, ctx);
1395 put_nfs_open_context(ctx);
1399 int nfs_atomic_open(struct inode *dir, struct dentry *dentry,
1400 struct file *file, unsigned open_flags,
1401 umode_t mode, int *opened)
1403 struct nfs_open_context *ctx;
1405 struct iattr attr = { .ia_valid = ATTR_OPEN };
1406 struct inode *inode;
1409 /* Expect a negative dentry */
1410 BUG_ON(dentry->d_inode);
1412 dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n",
1413 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1415 /* NFS only supports OPEN on regular files */
1416 if ((open_flags & O_DIRECTORY)) {
1417 if (!d_unhashed(dentry)) {
1419 * Hashed negative dentry with O_DIRECTORY: dentry was
1420 * revalidated and is fine, no need to perform lookup
1428 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
1429 return -ENAMETOOLONG;
1431 if (open_flags & O_CREAT) {
1432 attr.ia_valid |= ATTR_MODE;
1433 attr.ia_mode = mode & ~current_umask();
1435 if (open_flags & O_TRUNC) {
1436 attr.ia_valid |= ATTR_SIZE;
1440 ctx = create_nfs_open_context(dentry, open_flags);
1445 nfs_block_sillyrename(dentry->d_parent);
1446 inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr);
1447 nfs_unblock_sillyrename(dentry->d_parent);
1448 if (IS_ERR(inode)) {
1449 put_nfs_open_context(ctx);
1450 err = PTR_ERR(inode);
1454 d_add(dentry, NULL);
1460 if (!(open_flags & O_NOFOLLOW))
1470 err = nfs_finish_open(ctx, ctx->dentry, file, open_flags, opened);
1475 res = nfs_lookup(dir, dentry, 0);
1480 return finish_no_open(file, res);
1482 EXPORT_SYMBOL_GPL(nfs_atomic_open);
1484 static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags)
1486 struct dentry *parent = NULL;
1487 struct inode *inode;
1491 if (flags & LOOKUP_RCU)
1494 if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY))
1496 if (d_mountpoint(dentry))
1498 if (NFS_SB(dentry->d_sb)->caps & NFS_CAP_ATOMIC_OPEN_V1)
1501 inode = dentry->d_inode;
1502 parent = dget_parent(dentry);
1503 dir = parent->d_inode;
1505 /* We can't create new files in nfs_open_revalidate(), so we
1506 * optimize away revalidation of negative dentries.
1508 if (inode == NULL) {
1509 if (!nfs_neg_need_reval(dir, dentry, flags))
1514 /* NFS only supports OPEN on regular files */
1515 if (!S_ISREG(inode->i_mode))
1517 /* We cannot do exclusive creation on a positive dentry */
1518 if (flags & LOOKUP_EXCL)
1521 /* Let f_op->open() actually open (and revalidate) the file */
1531 return nfs_lookup_revalidate(dentry, flags);
1534 #endif /* CONFIG_NFSV4 */
1537 * Code common to create, mkdir, and mknod.
1539 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1540 struct nfs_fattr *fattr,
1541 struct nfs4_label *label)
1543 struct dentry *parent = dget_parent(dentry);
1544 struct inode *dir = parent->d_inode;
1545 struct inode *inode;
1546 int error = -EACCES;
1550 /* We may have been initialized further down */
1551 if (dentry->d_inode)
1553 if (fhandle->size == 0) {
1554 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr, NULL);
1558 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1559 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1560 struct nfs_server *server = NFS_SB(dentry->d_sb);
1561 error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr, NULL);
1565 inode = nfs_fhget(dentry->d_sb, fhandle, fattr, label);
1566 error = PTR_ERR(inode);
1569 d_add(dentry, inode);
1574 nfs_mark_for_revalidate(dir);
1578 EXPORT_SYMBOL_GPL(nfs_instantiate);
1581 * Following a failed create operation, we drop the dentry rather
1582 * than retain a negative dentry. This avoids a problem in the event
1583 * that the operation succeeded on the server, but an error in the
1584 * reply path made it appear to have failed.
1586 int nfs_create(struct inode *dir, struct dentry *dentry,
1587 umode_t mode, bool excl)
1590 int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT;
1593 dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
1594 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1596 attr.ia_mode = mode;
1597 attr.ia_valid = ATTR_MODE;
1599 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
1607 EXPORT_SYMBOL_GPL(nfs_create);
1610 * See comments for nfs_proc_create regarding failed operations.
1613 nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1618 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
1619 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1621 if (!new_valid_dev(rdev))
1624 attr.ia_mode = mode;
1625 attr.ia_valid = ATTR_MODE;
1627 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
1635 EXPORT_SYMBOL_GPL(nfs_mknod);
1638 * See comments for nfs_proc_create regarding failed operations.
1640 int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
1645 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
1646 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1648 attr.ia_valid = ATTR_MODE;
1649 attr.ia_mode = mode | S_IFDIR;
1651 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
1659 EXPORT_SYMBOL_GPL(nfs_mkdir);
1661 static void nfs_dentry_handle_enoent(struct dentry *dentry)
1663 if (dentry->d_inode != NULL && !d_unhashed(dentry))
1667 int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1671 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
1672 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1674 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
1675 /* Ensure the VFS deletes this inode */
1676 if (error == 0 && dentry->d_inode != NULL)
1677 clear_nlink(dentry->d_inode);
1678 else if (error == -ENOENT)
1679 nfs_dentry_handle_enoent(dentry);
1683 EXPORT_SYMBOL_GPL(nfs_rmdir);
1686 * Remove a file after making sure there are no pending writes,
1687 * and after checking that the file has only one user.
1689 * We invalidate the attribute cache and free the inode prior to the operation
1690 * to avoid possible races if the server reuses the inode.
1692 static int nfs_safe_remove(struct dentry *dentry)
1694 struct inode *dir = dentry->d_parent->d_inode;
1695 struct inode *inode = dentry->d_inode;
1698 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1699 dentry->d_parent->d_name.name, dentry->d_name.name);
1701 /* If the dentry was sillyrenamed, we simply call d_delete() */
1702 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1707 if (inode != NULL) {
1708 NFS_PROTO(inode)->return_delegation(inode);
1709 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1711 nfs_drop_nlink(inode);
1713 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1714 if (error == -ENOENT)
1715 nfs_dentry_handle_enoent(dentry);
1720 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1721 * belongs to an active ".nfs..." file and we return -EBUSY.
1723 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1725 int nfs_unlink(struct inode *dir, struct dentry *dentry)
1728 int need_rehash = 0;
1730 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1731 dir->i_ino, dentry->d_name.name);
1733 spin_lock(&dentry->d_lock);
1734 if (d_count(dentry) > 1) {
1735 spin_unlock(&dentry->d_lock);
1736 /* Start asynchronous writeout of the inode */
1737 write_inode_now(dentry->d_inode, 0);
1738 error = nfs_sillyrename(dir, dentry);
1741 if (!d_unhashed(dentry)) {
1745 spin_unlock(&dentry->d_lock);
1746 error = nfs_safe_remove(dentry);
1747 if (!error || error == -ENOENT) {
1748 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1749 } else if (need_rehash)
1753 EXPORT_SYMBOL_GPL(nfs_unlink);
1756 * To create a symbolic link, most file systems instantiate a new inode,
1757 * add a page to it containing the path, then write it out to the disk
1758 * using prepare_write/commit_write.
1760 * Unfortunately the NFS client can't create the in-core inode first
1761 * because it needs a file handle to create an in-core inode (see
1762 * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the
1763 * symlink request has completed on the server.
1765 * So instead we allocate a raw page, copy the symname into it, then do
1766 * the SYMLINK request with the page as the buffer. If it succeeds, we
1767 * now have a new file handle and can instantiate an in-core NFS inode
1768 * and move the raw page into its mapping.
1770 int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1775 unsigned int pathlen = strlen(symname);
1778 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1779 dir->i_ino, dentry->d_name.name, symname);
1781 if (pathlen > PAGE_SIZE)
1782 return -ENAMETOOLONG;
1784 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1785 attr.ia_valid = ATTR_MODE;
1787 page = alloc_page(GFP_HIGHUSER);
1791 kaddr = kmap_atomic(page);
1792 memcpy(kaddr, symname, pathlen);
1793 if (pathlen < PAGE_SIZE)
1794 memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
1795 kunmap_atomic(kaddr);
1797 error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
1799 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n",
1800 dir->i_sb->s_id, dir->i_ino,
1801 dentry->d_name.name, symname, error);
1808 * No big deal if we can't add this page to the page cache here.
1809 * READLINK will get the missing page from the server if needed.
1811 if (!add_to_page_cache_lru(page, dentry->d_inode->i_mapping, 0,
1813 SetPageUptodate(page);
1820 EXPORT_SYMBOL_GPL(nfs_symlink);
1823 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1825 struct inode *inode = old_dentry->d_inode;
1828 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
1829 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1830 dentry->d_parent->d_name.name, dentry->d_name.name);
1832 NFS_PROTO(inode)->return_delegation(inode);
1835 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1838 d_add(dentry, inode);
1842 EXPORT_SYMBOL_GPL(nfs_link);
1846 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
1847 * different file handle for the same inode after a rename (e.g. when
1848 * moving to a different directory). A fail-safe method to do so would
1849 * be to look up old_dir/old_name, create a link to new_dir/new_name and
1850 * rename the old file using the sillyrename stuff. This way, the original
1851 * file in old_dir will go away when the last process iput()s the inode.
1855 * It actually works quite well. One needs to have the possibility for
1856 * at least one ".nfs..." file in each directory the file ever gets
1857 * moved or linked to which happens automagically with the new
1858 * implementation that only depends on the dcache stuff instead of
1859 * using the inode layer
1861 * Unfortunately, things are a little more complicated than indicated
1862 * above. For a cross-directory move, we want to make sure we can get
1863 * rid of the old inode after the operation. This means there must be
1864 * no pending writes (if it's a file), and the use count must be 1.
1865 * If these conditions are met, we can drop the dentries before doing
1868 int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1869 struct inode *new_dir, struct dentry *new_dentry)
1871 struct inode *old_inode = old_dentry->d_inode;
1872 struct inode *new_inode = new_dentry->d_inode;
1873 struct dentry *dentry = NULL, *rehash = NULL;
1876 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
1877 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1878 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
1879 d_count(new_dentry));
1882 * For non-directories, check whether the target is busy and if so,
1883 * make a copy of the dentry and then do a silly-rename. If the
1884 * silly-rename succeeds, the copied dentry is hashed and becomes
1887 if (new_inode && !S_ISDIR(new_inode->i_mode)) {
1889 * To prevent any new references to the target during the
1890 * rename, we unhash the dentry in advance.
1892 if (!d_unhashed(new_dentry)) {
1894 rehash = new_dentry;
1897 if (d_count(new_dentry) > 2) {
1900 /* copy the target dentry's name */
1901 dentry = d_alloc(new_dentry->d_parent,
1902 &new_dentry->d_name);
1906 /* silly-rename the existing target ... */
1907 err = nfs_sillyrename(new_dir, new_dentry);
1911 new_dentry = dentry;
1917 NFS_PROTO(old_inode)->return_delegation(old_inode);
1918 if (new_inode != NULL)
1919 NFS_PROTO(new_inode)->return_delegation(new_inode);
1921 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
1922 new_dir, &new_dentry->d_name);
1923 nfs_mark_for_revalidate(old_inode);
1928 if (new_inode != NULL)
1929 nfs_drop_nlink(new_inode);
1930 d_move(old_dentry, new_dentry);
1931 nfs_set_verifier(new_dentry,
1932 nfs_save_change_attribute(new_dir));
1933 } else if (error == -ENOENT)
1934 nfs_dentry_handle_enoent(old_dentry);
1936 /* new dentry created? */
1941 EXPORT_SYMBOL_GPL(nfs_rename);
1943 static DEFINE_SPINLOCK(nfs_access_lru_lock);
1944 static LIST_HEAD(nfs_access_lru_list);
1945 static atomic_long_t nfs_access_nr_entries;
1947 static void nfs_access_free_entry(struct nfs_access_entry *entry)
1949 put_rpccred(entry->cred);
1951 smp_mb__before_atomic_dec();
1952 atomic_long_dec(&nfs_access_nr_entries);
1953 smp_mb__after_atomic_dec();
1956 static void nfs_access_free_list(struct list_head *head)
1958 struct nfs_access_entry *cache;
1960 while (!list_empty(head)) {
1961 cache = list_entry(head->next, struct nfs_access_entry, lru);
1962 list_del(&cache->lru);
1963 nfs_access_free_entry(cache);
1967 int nfs_access_cache_shrinker(struct shrinker *shrink,
1968 struct shrink_control *sc)
1971 struct nfs_inode *nfsi, *next;
1972 struct nfs_access_entry *cache;
1973 int nr_to_scan = sc->nr_to_scan;
1974 gfp_t gfp_mask = sc->gfp_mask;
1976 if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL)
1977 return (nr_to_scan == 0) ? 0 : -1;
1979 spin_lock(&nfs_access_lru_lock);
1980 list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) {
1981 struct inode *inode;
1983 if (nr_to_scan-- == 0)
1985 inode = &nfsi->vfs_inode;
1986 spin_lock(&inode->i_lock);
1987 if (list_empty(&nfsi->access_cache_entry_lru))
1988 goto remove_lru_entry;
1989 cache = list_entry(nfsi->access_cache_entry_lru.next,
1990 struct nfs_access_entry, lru);
1991 list_move(&cache->lru, &head);
1992 rb_erase(&cache->rb_node, &nfsi->access_cache);
1993 if (!list_empty(&nfsi->access_cache_entry_lru))
1994 list_move_tail(&nfsi->access_cache_inode_lru,
1995 &nfs_access_lru_list);
1998 list_del_init(&nfsi->access_cache_inode_lru);
1999 smp_mb__before_clear_bit();
2000 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
2001 smp_mb__after_clear_bit();
2003 spin_unlock(&inode->i_lock);
2005 spin_unlock(&nfs_access_lru_lock);
2006 nfs_access_free_list(&head);
2007 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
2010 static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head)
2012 struct rb_root *root_node = &nfsi->access_cache;
2014 struct nfs_access_entry *entry;
2016 /* Unhook entries from the cache */
2017 while ((n = rb_first(root_node)) != NULL) {
2018 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2019 rb_erase(n, root_node);
2020 list_move(&entry->lru, head);
2022 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
2025 void nfs_access_zap_cache(struct inode *inode)
2029 if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0)
2031 /* Remove from global LRU init */
2032 spin_lock(&nfs_access_lru_lock);
2033 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2034 list_del_init(&NFS_I(inode)->access_cache_inode_lru);
2036 spin_lock(&inode->i_lock);
2037 __nfs_access_zap_cache(NFS_I(inode), &head);
2038 spin_unlock(&inode->i_lock);
2039 spin_unlock(&nfs_access_lru_lock);
2040 nfs_access_free_list(&head);
2042 EXPORT_SYMBOL_GPL(nfs_access_zap_cache);
2044 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
2046 struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
2047 struct nfs_access_entry *entry;
2050 entry = rb_entry(n, struct nfs_access_entry, rb_node);
2052 if (cred < entry->cred)
2054 else if (cred > entry->cred)
2062 static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
2064 struct nfs_inode *nfsi = NFS_I(inode);
2065 struct nfs_access_entry *cache;
2068 spin_lock(&inode->i_lock);
2069 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
2071 cache = nfs_access_search_rbtree(inode, cred);
2074 if (!nfs_have_delegated_attributes(inode) &&
2075 !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo))
2077 res->jiffies = cache->jiffies;
2078 res->cred = cache->cred;
2079 res->mask = cache->mask;
2080 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
2083 spin_unlock(&inode->i_lock);
2086 rb_erase(&cache->rb_node, &nfsi->access_cache);
2087 list_del(&cache->lru);
2088 spin_unlock(&inode->i_lock);
2089 nfs_access_free_entry(cache);
2092 spin_unlock(&inode->i_lock);
2093 nfs_access_zap_cache(inode);
2097 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
2099 struct nfs_inode *nfsi = NFS_I(inode);
2100 struct rb_root *root_node = &nfsi->access_cache;
2101 struct rb_node **p = &root_node->rb_node;
2102 struct rb_node *parent = NULL;
2103 struct nfs_access_entry *entry;
2105 spin_lock(&inode->i_lock);
2106 while (*p != NULL) {
2108 entry = rb_entry(parent, struct nfs_access_entry, rb_node);
2110 if (set->cred < entry->cred)
2111 p = &parent->rb_left;
2112 else if (set->cred > entry->cred)
2113 p = &parent->rb_right;
2117 rb_link_node(&set->rb_node, parent, p);
2118 rb_insert_color(&set->rb_node, root_node);
2119 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2120 spin_unlock(&inode->i_lock);
2123 rb_replace_node(parent, &set->rb_node, root_node);
2124 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
2125 list_del(&entry->lru);
2126 spin_unlock(&inode->i_lock);
2127 nfs_access_free_entry(entry);
2130 void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
2132 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
2135 RB_CLEAR_NODE(&cache->rb_node);
2136 cache->jiffies = set->jiffies;
2137 cache->cred = get_rpccred(set->cred);
2138 cache->mask = set->mask;
2140 nfs_access_add_rbtree(inode, cache);
2142 /* Update accounting */
2143 smp_mb__before_atomic_inc();
2144 atomic_long_inc(&nfs_access_nr_entries);
2145 smp_mb__after_atomic_inc();
2147 /* Add inode to global LRU list */
2148 if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) {
2149 spin_lock(&nfs_access_lru_lock);
2150 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags))
2151 list_add_tail(&NFS_I(inode)->access_cache_inode_lru,
2152 &nfs_access_lru_list);
2153 spin_unlock(&nfs_access_lru_lock);
2156 EXPORT_SYMBOL_GPL(nfs_access_add_cache);
2158 void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result)
2161 if (access_result & NFS4_ACCESS_READ)
2162 entry->mask |= MAY_READ;
2164 (NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND | NFS4_ACCESS_DELETE))
2165 entry->mask |= MAY_WRITE;
2166 if (access_result & (NFS4_ACCESS_LOOKUP|NFS4_ACCESS_EXECUTE))
2167 entry->mask |= MAY_EXEC;
2169 EXPORT_SYMBOL_GPL(nfs_access_set_mask);
2171 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
2173 struct nfs_access_entry cache;
2176 status = nfs_access_get_cached(inode, cred, &cache);
2180 /* Be clever: ask server to check for all possible rights */
2181 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
2183 cache.jiffies = jiffies;
2184 status = NFS_PROTO(inode)->access(inode, &cache);
2186 if (status == -ESTALE) {
2187 nfs_zap_caches(inode);
2188 if (!S_ISDIR(inode->i_mode))
2189 set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
2193 nfs_access_add_cache(inode, &cache);
2195 if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2200 static int nfs_open_permission_mask(int openflags)
2204 if (openflags & __FMODE_EXEC) {
2205 /* ONLY check exec rights */
2208 if ((openflags & O_ACCMODE) != O_WRONLY)
2210 if ((openflags & O_ACCMODE) != O_RDONLY)
2217 int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
2219 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
2221 EXPORT_SYMBOL_GPL(nfs_may_open);
2223 int nfs_permission(struct inode *inode, int mask)
2225 struct rpc_cred *cred;
2228 if (mask & MAY_NOT_BLOCK)
2231 nfs_inc_stats(inode, NFSIOS_VFSACCESS);
2233 if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0)
2235 /* Is this sys_access() ? */
2236 if (mask & (MAY_ACCESS | MAY_CHDIR))
2239 switch (inode->i_mode & S_IFMT) {
2243 /* NFSv4 has atomic_open... */
2244 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
2245 && (mask & MAY_OPEN)
2246 && !(mask & MAY_EXEC))
2251 * Optimize away all write operations, since the server
2252 * will check permissions when we perform the op.
2254 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
2259 if (!NFS_PROTO(inode)->access)
2262 cred = rpc_lookup_cred();
2263 if (!IS_ERR(cred)) {
2264 res = nfs_do_access(inode, cred, mask);
2267 res = PTR_ERR(cred);
2269 if (!res && (mask & MAY_EXEC) && !execute_ok(inode))
2272 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
2273 inode->i_sb->s_id, inode->i_ino, mask, res);
2276 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
2278 res = generic_permission(inode, mask);
2281 EXPORT_SYMBOL_GPL(nfs_permission);
2285 * version-control: t
2286 * kept-new-versions: 5