4 * Copyright (C) 1992 Rick Sladkey
6 * nfs directory handling functions
8 * 10 Apr 1996 Added silly rename for unlink --okir
9 * 28 Sep 1996 Improved directory cache --okir
10 * 23 Aug 1997 Claus Heine claus@momo.math.rwth-aachen.de
11 * Re-implemented silly rename for unlink, newly implemented
12 * silly rename for nfs_rename() following the suggestions
13 * of Olaf Kirch (okir) found in this file.
14 * Following Linus comments on my original hack, this version
15 * depends only on the dcache stuff and doesn't touch the inode
16 * layer (iput() and friends).
17 * 6 Jun 1999 Cache readdir lookups in the page cache. -DaveM
20 #include <linux/time.h>
21 #include <linux/errno.h>
22 #include <linux/stat.h>
23 #include <linux/fcntl.h>
24 #include <linux/string.h>
25 #include <linux/kernel.h>
26 #include <linux/slab.h>
28 #include <linux/sunrpc/clnt.h>
29 #include <linux/nfs_fs.h>
30 #include <linux/nfs_mount.h>
31 #include <linux/pagemap.h>
32 #include <linux/smp_lock.h>
33 #include <linux/pagevec.h>
34 #include <linux/namei.h>
35 #include <linux/mount.h>
36 #include <linux/sched.h>
39 #include "delegation.h"
42 /* #define NFS_DEBUG_VERBOSE 1 */
44 static int nfs_opendir(struct inode *, struct file *);
45 static int nfs_readdir(struct file *, void *, filldir_t);
46 static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
47 static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *);
48 static int nfs_mkdir(struct inode *, struct dentry *, int);
49 static int nfs_rmdir(struct inode *, struct dentry *);
50 static int nfs_unlink(struct inode *, struct dentry *);
51 static int nfs_symlink(struct inode *, struct dentry *, const char *);
52 static int nfs_link(struct dentry *, struct inode *, struct dentry *);
53 static int nfs_mknod(struct inode *, struct dentry *, int, dev_t);
54 static int nfs_rename(struct inode *, struct dentry *,
55 struct inode *, struct dentry *);
56 static int nfs_fsync_dir(struct file *, struct dentry *, int);
57 static loff_t nfs_llseek_dir(struct file *, loff_t, int);
59 const struct file_operations nfs_dir_operations = {
60 .llseek = nfs_llseek_dir,
61 .read = generic_read_dir,
62 .readdir = nfs_readdir,
64 .release = nfs_release,
65 .fsync = nfs_fsync_dir,
68 const struct inode_operations nfs_dir_inode_operations = {
73 .symlink = nfs_symlink,
78 .permission = nfs_permission,
79 .getattr = nfs_getattr,
80 .setattr = nfs_setattr,
84 const struct inode_operations nfs3_dir_inode_operations = {
89 .symlink = nfs_symlink,
94 .permission = nfs_permission,
95 .getattr = nfs_getattr,
96 .setattr = nfs_setattr,
97 .listxattr = nfs3_listxattr,
98 .getxattr = nfs3_getxattr,
99 .setxattr = nfs3_setxattr,
100 .removexattr = nfs3_removexattr,
102 #endif /* CONFIG_NFS_V3 */
106 static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
107 const struct inode_operations nfs4_dir_inode_operations = {
108 .create = nfs_create,
109 .lookup = nfs_atomic_lookup,
111 .unlink = nfs_unlink,
112 .symlink = nfs_symlink,
116 .rename = nfs_rename,
117 .permission = nfs_permission,
118 .getattr = nfs_getattr,
119 .setattr = nfs_setattr,
120 .getxattr = nfs4_getxattr,
121 .setxattr = nfs4_setxattr,
122 .listxattr = nfs4_listxattr,
125 #endif /* CONFIG_NFS_V4 */
131 nfs_opendir(struct inode *inode, struct file *filp)
135 dfprintk(VFS, "NFS: opendir(%s/%ld)\n",
136 inode->i_sb->s_id, inode->i_ino);
139 /* Call generic open code in order to cache credentials */
140 res = nfs_open(inode, filp);
145 typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int);
149 unsigned long page_index;
152 loff_t current_index;
153 struct nfs_entry *entry;
154 decode_dirent_t decode;
157 unsigned long timestamp;
159 } nfs_readdir_descriptor_t;
161 /* Now we cache directories properly, by stuffing the dirent
162 * data directly in the page cache.
164 * Inode invalidation due to refresh etc. takes care of
165 * _everything_, no sloppy entry flushing logic, no extraneous
166 * copying, network direct to page cache, the way it was meant
169 * NOTE: Dirent information verification is done always by the
170 * page-in of the RPC reply, nowhere else, this simplies
171 * things substantially.
174 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page)
176 struct file *file = desc->file;
177 struct inode *inode = file->f_path.dentry->d_inode;
178 struct rpc_cred *cred = nfs_file_cred(file);
179 unsigned long timestamp;
182 dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n",
183 __FUNCTION__, (long long)desc->entry->cookie,
188 error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, desc->entry->cookie, page,
189 NFS_SERVER(inode)->dtsize, desc->plus);
191 /* We requested READDIRPLUS, but the server doesn't grok it */
192 if (error == -ENOTSUPP && desc->plus) {
193 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
194 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
200 desc->timestamp = timestamp;
201 desc->timestamp_valid = 1;
202 SetPageUptodate(page);
203 spin_lock(&inode->i_lock);
204 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
205 spin_unlock(&inode->i_lock);
206 /* Ensure consistent page alignment of the data.
207 * Note: assumes we have exclusive access to this mapping either
208 * through inode->i_mutex or some other mechanism.
210 if (page->index == 0 && invalidate_inode_pages2_range(inode->i_mapping, PAGE_CACHE_SIZE, -1) < 0) {
211 /* Should never happen */
212 nfs_zap_mapping(inode, inode->i_mapping);
219 nfs_zap_caches(inode);
225 int dir_decode(nfs_readdir_descriptor_t *desc)
227 __be32 *p = desc->ptr;
228 p = desc->decode(p, desc->entry, desc->plus);
232 if (desc->timestamp_valid)
233 desc->entry->fattr->time_start = desc->timestamp;
235 desc->entry->fattr->valid &= ~NFS_ATTR_FATTR;
240 void dir_page_release(nfs_readdir_descriptor_t *desc)
243 page_cache_release(desc->page);
249 * Given a pointer to a buffer that has already been filled by a call
250 * to readdir, find the next entry with cookie '*desc->dir_cookie'.
252 * If the end of the buffer has been reached, return -EAGAIN, if not,
253 * return the offset within the buffer of the next entry to be
257 int find_dirent(nfs_readdir_descriptor_t *desc)
259 struct nfs_entry *entry = desc->entry;
263 while((status = dir_decode(desc)) == 0) {
264 dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n",
265 __FUNCTION__, (unsigned long long)entry->cookie);
266 if (entry->prev_cookie == *desc->dir_cookie)
268 if (loop_count++ > 200) {
277 * Given a pointer to a buffer that has already been filled by a call
278 * to readdir, find the entry at offset 'desc->file->f_pos'.
280 * If the end of the buffer has been reached, return -EAGAIN, if not,
281 * return the offset within the buffer of the next entry to be
285 int find_dirent_index(nfs_readdir_descriptor_t *desc)
287 struct nfs_entry *entry = desc->entry;
292 status = dir_decode(desc);
296 dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n",
297 (unsigned long long)entry->cookie, desc->current_index);
299 if (desc->file->f_pos == desc->current_index) {
300 *desc->dir_cookie = entry->cookie;
303 desc->current_index++;
304 if (loop_count++ > 200) {
313 * Find the given page, and call find_dirent() or find_dirent_index in
314 * order to try to return the next entry.
317 int find_dirent_page(nfs_readdir_descriptor_t *desc)
319 struct inode *inode = desc->file->f_path.dentry->d_inode;
323 dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n",
324 __FUNCTION__, desc->page_index,
325 (long long) *desc->dir_cookie);
327 /* If we find the page in the page_cache, we cannot be sure
328 * how fresh the data is, so we will ignore readdir_plus attributes.
330 desc->timestamp_valid = 0;
331 page = read_cache_page(inode->i_mapping, desc->page_index,
332 (filler_t *)nfs_readdir_filler, desc);
334 status = PTR_ERR(page);
338 /* NOTE: Someone else may have changed the READDIRPLUS flag */
340 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
341 if (*desc->dir_cookie != 0)
342 status = find_dirent(desc);
344 status = find_dirent_index(desc);
346 dir_page_release(desc);
348 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, status);
353 * Recurse through the page cache pages, and return a
354 * filled nfs_entry structure of the next directory entry if possible.
356 * The target for the search is '*desc->dir_cookie' if non-0,
357 * 'desc->file->f_pos' otherwise
360 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
365 /* Always search-by-index from the beginning of the cache */
366 if (*desc->dir_cookie == 0) {
367 dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n",
368 (long long)desc->file->f_pos);
369 desc->page_index = 0;
370 desc->entry->cookie = desc->entry->prev_cookie = 0;
371 desc->entry->eof = 0;
372 desc->current_index = 0;
374 dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n",
375 (unsigned long long)*desc->dir_cookie);
378 res = find_dirent_page(desc);
381 /* Align to beginning of next page */
383 if (loop_count++ > 200) {
389 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, res);
393 static inline unsigned int dt_type(struct inode *inode)
395 return (inode->i_mode >> 12) & 15;
398 static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc);
401 * Once we've found the start of the dirent within a page: fill 'er up...
404 int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
407 struct file *file = desc->file;
408 struct nfs_entry *entry = desc->entry;
409 struct dentry *dentry = NULL;
414 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n",
415 (unsigned long long)entry->cookie);
418 unsigned d_type = DT_UNKNOWN;
419 /* Note: entry->prev_cookie contains the cookie for
420 * retrieving the current dirent on the server */
423 /* Get a dentry if we have one */
426 dentry = nfs_readdir_lookup(desc);
428 /* Use readdirplus info */
429 if (dentry != NULL && dentry->d_inode != NULL) {
430 d_type = dt_type(dentry->d_inode);
431 fileid = NFS_FILEID(dentry->d_inode);
434 res = filldir(dirent, entry->name, entry->len,
435 file->f_pos, fileid, d_type);
439 *desc->dir_cookie = entry->cookie;
440 if (dir_decode(desc) != 0) {
444 if (loop_count++ > 200) {
449 dir_page_release(desc);
452 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
453 (unsigned long long)*desc->dir_cookie, res);
458 * If we cannot find a cookie in our cache, we suspect that this is
459 * because it points to a deleted file, so we ask the server to return
460 * whatever it thinks is the next entry. We then feed this to filldir.
461 * If all goes well, we should then be able to find our way round the
462 * cache on the next call to readdir_search_pagecache();
464 * NOTE: we cannot add the anonymous page to the pagecache because
465 * the data it contains might not be page aligned. Besides,
466 * we should already have a complete representation of the
467 * directory in the page cache by the time we get here.
470 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
473 struct file *file = desc->file;
474 struct inode *inode = file->f_path.dentry->d_inode;
475 struct rpc_cred *cred = nfs_file_cred(file);
476 struct page *page = NULL;
478 unsigned long timestamp;
480 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
481 (unsigned long long)*desc->dir_cookie);
483 page = alloc_page(GFP_HIGHUSER);
489 desc->error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, *desc->dir_cookie,
491 NFS_SERVER(inode)->dtsize,
493 spin_lock(&inode->i_lock);
494 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
495 spin_unlock(&inode->i_lock);
497 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
498 if (desc->error >= 0) {
499 desc->timestamp = timestamp;
500 desc->timestamp_valid = 1;
501 if ((status = dir_decode(desc)) == 0)
502 desc->entry->prev_cookie = *desc->dir_cookie;
508 status = nfs_do_filldir(desc, dirent, filldir);
510 /* Reset read descriptor so it searches the page cache from
511 * the start upon the next call to readdir_search_pagecache() */
512 desc->page_index = 0;
513 desc->entry->cookie = desc->entry->prev_cookie = 0;
514 desc->entry->eof = 0;
516 dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
517 __FUNCTION__, status);
520 dir_page_release(desc);
524 /* The file offset position represents the dirent entry number. A
525 last cookie cache takes care of the common case of reading the
528 static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
530 struct dentry *dentry = filp->f_path.dentry;
531 struct inode *inode = dentry->d_inode;
532 nfs_readdir_descriptor_t my_desc,
534 struct nfs_entry my_entry;
536 struct nfs_fattr fattr;
539 dfprintk(VFS, "NFS: readdir(%s/%s) starting at cookie %Lu\n",
540 dentry->d_parent->d_name.name, dentry->d_name.name,
541 (long long)filp->f_pos);
542 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
546 res = nfs_revalidate_mapping_nolock(inode, filp->f_mapping);
553 * filp->f_pos points to the dirent entry number.
554 * *desc->dir_cookie has the cookie for the next entry. We have
555 * to either find the entry with the appropriate number or
556 * revalidate the cookie.
558 memset(desc, 0, sizeof(*desc));
561 desc->dir_cookie = &nfs_file_open_context(filp)->dir_cookie;
562 desc->decode = NFS_PROTO(inode)->decode_dirent;
563 desc->plus = NFS_USE_READDIRPLUS(inode);
565 my_entry.cookie = my_entry.prev_cookie = 0;
568 my_entry.fattr = &fattr;
569 nfs_fattr_init(&fattr);
570 desc->entry = &my_entry;
572 while(!desc->entry->eof) {
573 res = readdir_search_pagecache(desc);
575 if (res == -EBADCOOKIE) {
576 /* This means either end of directory */
577 if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) {
578 /* Or that the server has 'lost' a cookie */
579 res = uncached_readdir(desc, dirent, filldir);
586 if (res == -ETOOSMALL && desc->plus) {
587 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
588 nfs_zap_caches(inode);
590 desc->entry->eof = 0;
596 res = nfs_do_filldir(desc, dirent, filldir);
605 dfprintk(VFS, "NFS: readdir(%s/%s) returns %ld\n",
606 dentry->d_parent->d_name.name, dentry->d_name.name,
611 static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
613 mutex_lock(&filp->f_path.dentry->d_inode->i_mutex);
616 offset += filp->f_pos;
624 if (offset != filp->f_pos) {
625 filp->f_pos = offset;
626 nfs_file_open_context(filp)->dir_cookie = 0;
629 mutex_unlock(&filp->f_path.dentry->d_inode->i_mutex);
634 * All directory operations under NFS are synchronous, so fsync()
635 * is a dummy operation.
637 static int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync)
639 dfprintk(VFS, "NFS: fsync_dir(%s/%s) datasync %d\n",
640 dentry->d_parent->d_name.name, dentry->d_name.name,
647 * A check for whether or not the parent directory has changed.
648 * In the case it has, we assume that the dentries are untrustworthy
649 * and may need to be looked up again.
651 static int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
655 if (dentry->d_time == NFS_I(dir)->cache_change_attribute)
660 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
662 dentry->d_time = verf;
666 * Return the intent data that applies to this particular path component
668 * Note that the current set of intents only apply to the very last
669 * component of the path.
670 * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
672 static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
674 if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
676 return nd->flags & mask;
680 * Inode and filehandle revalidation for lookups.
682 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
683 * or if the intent information indicates that we're about to open this
684 * particular file and the "nocto" mount flag is not set.
688 int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
690 struct nfs_server *server = NFS_SERVER(inode);
693 /* VFS wants an on-the-wire revalidation */
694 if (nd->flags & LOOKUP_REVAL)
696 /* This is an open(2) */
697 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
698 !(server->flags & NFS_MOUNT_NOCTO) &&
699 (S_ISREG(inode->i_mode) ||
700 S_ISDIR(inode->i_mode)))
703 return nfs_revalidate_inode(server, inode);
705 return __nfs_revalidate_inode(server, inode);
709 * We judge how long we want to trust negative
710 * dentries by looking at the parent inode mtime.
712 * If parent mtime has changed, we revalidate, else we wait for a
713 * period corresponding to the parent's attribute cache timeout value.
716 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
717 struct nameidata *nd)
719 /* Don't revalidate a negative dentry if we're creating a new file */
720 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
722 return !nfs_check_verifier(dir, dentry);
726 * This is called every time the dcache has a lookup hit,
727 * and we should check whether we can really trust that
730 * NOTE! The hit can be a negative hit too, don't assume
733 * If the parent directory is seen to have changed, we throw out the
734 * cached dentry and do a new lookup.
736 static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
740 struct dentry *parent;
742 struct nfs_fh fhandle;
743 struct nfs_fattr fattr;
744 unsigned long verifier;
746 parent = dget_parent(dentry);
748 dir = parent->d_inode;
749 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
750 inode = dentry->d_inode;
752 /* Revalidate parent directory attribute cache */
753 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
757 if (nfs_neg_need_reval(dir, dentry, nd))
762 if (is_bad_inode(inode)) {
763 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
764 __FUNCTION__, dentry->d_parent->d_name.name,
765 dentry->d_name.name);
769 /* Force a full look up iff the parent directory has changed */
770 if (nfs_check_verifier(dir, dentry)) {
771 if (nfs_lookup_verify_inode(inode, nd))
776 if (NFS_STALE(inode))
779 verifier = nfs_save_change_attribute(dir);
780 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
783 if (nfs_compare_fh(NFS_FH(inode), &fhandle))
785 if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
788 nfs_set_verifier(dentry, verifier);
792 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
793 __FUNCTION__, dentry->d_parent->d_name.name,
794 dentry->d_name.name);
800 if (inode && S_ISDIR(inode->i_mode)) {
801 /* Purge readdir caches. */
802 nfs_zap_caches(inode);
803 /* If we have submounts, don't unhash ! */
804 if (have_submounts(dentry))
806 shrink_dcache_parent(dentry);
811 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
812 __FUNCTION__, dentry->d_parent->d_name.name,
813 dentry->d_name.name);
818 * This is called from dput() when d_count is going to 0.
820 static int nfs_dentry_delete(struct dentry *dentry)
822 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
823 dentry->d_parent->d_name.name, dentry->d_name.name,
826 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
827 /* Unhash it, so that ->d_iput() would be called */
830 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
831 /* Unhash it, so that ancestors of killed async unlink
832 * files will be cleaned up during umount */
840 * Called when the dentry loses inode.
841 * We use it to clean up silly-renamed files.
843 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
845 nfs_inode_return_delegation(inode);
846 if (S_ISDIR(inode->i_mode))
847 /* drop any readdir cache as it could easily be old */
848 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA;
850 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
853 nfs_complete_unlink(dentry, inode);
859 struct dentry_operations nfs_dentry_operations = {
860 .d_revalidate = nfs_lookup_revalidate,
861 .d_delete = nfs_dentry_delete,
862 .d_iput = nfs_dentry_iput,
866 * Use intent information to check whether or not we're going to do
867 * an O_EXCL create using this path component.
870 int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
872 if (NFS_PROTO(dir)->version == 2)
874 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0)
876 return (nd->intent.open.flags & O_EXCL) != 0;
879 static inline int nfs_reval_fsid(struct inode *dir, const struct nfs_fattr *fattr)
881 struct nfs_server *server = NFS_SERVER(dir);
883 if (!nfs_fsid_equal(&server->fsid, &fattr->fsid))
884 /* Revalidate fsid using the parent directory */
885 return __nfs_revalidate_inode(server, dir);
889 static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
892 struct inode *inode = NULL;
894 struct nfs_fh fhandle;
895 struct nfs_fattr fattr;
897 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
898 dentry->d_parent->d_name.name, dentry->d_name.name);
899 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
901 res = ERR_PTR(-ENAMETOOLONG);
902 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
905 res = ERR_PTR(-ENOMEM);
906 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
911 * If we're doing an exclusive create, optimize away the lookup
912 * but don't hash the dentry.
914 if (nfs_is_exclusive_create(dir, nd)) {
915 d_instantiate(dentry, NULL);
920 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
921 if (error == -ENOENT)
924 res = ERR_PTR(error);
927 error = nfs_reval_fsid(dir, &fattr);
929 res = ERR_PTR(error);
932 inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
933 res = (struct dentry *)inode;
938 res = d_materialise_unique(dentry, inode);
940 struct dentry *parent;
943 /* Was a directory renamed! */
944 parent = dget_parent(res);
945 if (!IS_ROOT(parent))
946 nfs_mark_for_revalidate(parent->d_inode);
950 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
958 static int nfs_open_revalidate(struct dentry *, struct nameidata *);
960 struct dentry_operations nfs4_dentry_operations = {
961 .d_revalidate = nfs_open_revalidate,
962 .d_delete = nfs_dentry_delete,
963 .d_iput = nfs_dentry_iput,
967 * Use intent information to determine whether we need to substitute
968 * the NFSv4-style stateful OPEN for the LOOKUP call
970 static int is_atomic_open(struct inode *dir, struct nameidata *nd)
972 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
974 /* NFS does not (yet) have a stateful open for directories */
975 if (nd->flags & LOOKUP_DIRECTORY)
977 /* Are we trying to write to a read only partition? */
978 if (IS_RDONLY(dir) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE)))
983 static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
985 struct dentry *res = NULL;
988 dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
989 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
991 /* Check that we are indeed trying to open this file */
992 if (!is_atomic_open(dir, nd))
995 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
996 res = ERR_PTR(-ENAMETOOLONG);
999 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
1001 /* Let vfs_create() deal with O_EXCL */
1002 if (nd->intent.open.flags & O_EXCL) {
1003 d_add(dentry, NULL);
1007 /* Open the file on the server */
1009 /* Revalidate parent directory attribute cache */
1010 error = nfs_revalidate_inode(NFS_SERVER(dir), dir);
1012 res = ERR_PTR(error);
1017 if (nd->intent.open.flags & O_CREAT) {
1018 nfs_begin_data_update(dir);
1019 res = nfs4_atomic_open(dir, dentry, nd);
1020 nfs_end_data_update(dir);
1022 res = nfs4_atomic_open(dir, dentry, nd);
1025 error = PTR_ERR(res);
1027 /* Make a negative dentry */
1031 /* This turned out not to be a regular file */
1036 if (!(nd->intent.open.flags & O_NOFOLLOW))
1042 } else if (res != NULL)
1044 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1048 return nfs_lookup(dir, dentry, nd);
1051 static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
1053 struct dentry *parent = NULL;
1054 struct inode *inode = dentry->d_inode;
1056 unsigned long verifier;
1057 int openflags, ret = 0;
1059 parent = dget_parent(dentry);
1060 dir = parent->d_inode;
1061 if (!is_atomic_open(dir, nd))
1063 /* We can't create new files in nfs_open_revalidate(), so we
1064 * optimize away revalidation of negative dentries.
1068 /* NFS only supports OPEN on regular files */
1069 if (!S_ISREG(inode->i_mode))
1071 openflags = nd->intent.open.flags;
1072 /* We cannot do exclusive creation on a positive dentry */
1073 if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
1075 /* We can't create new files, or truncate existing ones here */
1076 openflags &= ~(O_CREAT|O_TRUNC);
1079 * Note: we're not holding inode->i_mutex and so may be racing with
1080 * operations that change the directory. We therefore save the
1081 * change attribute *before* we do the RPC call.
1084 verifier = nfs_save_change_attribute(dir);
1085 ret = nfs4_open_revalidate(dir, dentry, openflags, nd);
1087 nfs_set_verifier(dentry, verifier);
1096 if (inode != NULL && nfs_have_delegation(inode, FMODE_READ))
1098 return nfs_lookup_revalidate(dentry, nd);
1100 #endif /* CONFIG_NFSV4 */
1102 static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc)
1104 struct dentry *parent = desc->file->f_path.dentry;
1105 struct inode *dir = parent->d_inode;
1106 struct nfs_entry *entry = desc->entry;
1107 struct dentry *dentry, *alias;
1108 struct qstr name = {
1109 .name = entry->name,
1112 struct inode *inode;
1113 unsigned long verf = nfs_save_change_attribute(dir);
1117 if (name.name[0] == '.' && name.name[1] == '.')
1118 return dget_parent(parent);
1121 if (name.name[0] == '.')
1122 return dget(parent);
1125 spin_lock(&dir->i_lock);
1126 if (NFS_I(dir)->cache_validity & NFS_INO_INVALID_DATA) {
1127 spin_unlock(&dir->i_lock);
1130 spin_unlock(&dir->i_lock);
1132 name.hash = full_name_hash(name.name, name.len);
1133 dentry = d_lookup(parent, &name);
1134 if (dentry != NULL) {
1135 /* Is this a positive dentry that matches the readdir info? */
1136 if (dentry->d_inode != NULL &&
1137 (NFS_FILEID(dentry->d_inode) == entry->ino ||
1138 d_mountpoint(dentry))) {
1139 if (!desc->plus || entry->fh->size == 0)
1141 if (nfs_compare_fh(NFS_FH(dentry->d_inode),
1145 /* No, so d_drop to allow one to be created */
1149 if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR))
1151 if (name.len > NFS_SERVER(dir)->namelen)
1153 /* Note: caller is already holding the dir->i_mutex! */
1154 dentry = d_alloc(parent, &name);
1157 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
1158 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
1159 if (IS_ERR(inode)) {
1164 alias = d_materialise_unique(dentry, inode);
1165 if (alias != NULL) {
1173 nfs_set_verifier(dentry, verf);
1178 * Code common to create, mkdir, and mknod.
1180 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1181 struct nfs_fattr *fattr)
1183 struct inode *inode;
1184 int error = -EACCES;
1186 /* We may have been initialized further down */
1187 if (dentry->d_inode)
1189 if (fhandle->size == 0) {
1190 struct inode *dir = dentry->d_parent->d_inode;
1191 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
1195 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1196 struct nfs_server *server = NFS_SB(dentry->d_sb);
1197 error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr);
1201 inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1202 error = PTR_ERR(inode);
1205 d_instantiate(dentry, inode);
1206 if (d_unhashed(dentry))
1212 * Following a failed create operation, we drop the dentry rather
1213 * than retain a negative dentry. This avoids a problem in the event
1214 * that the operation succeeded on the server, but an error in the
1215 * reply path made it appear to have failed.
1217 static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
1218 struct nameidata *nd)
1224 dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
1225 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1227 attr.ia_mode = mode;
1228 attr.ia_valid = ATTR_MODE;
1230 if ((nd->flags & LOOKUP_CREATE) != 0)
1231 open_flags = nd->intent.open.flags;
1234 nfs_begin_data_update(dir);
1235 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, nd);
1236 nfs_end_data_update(dir);
1239 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1249 * See comments for nfs_proc_create regarding failed operations.
1252 nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1257 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
1258 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1260 if (!new_valid_dev(rdev))
1263 attr.ia_mode = mode;
1264 attr.ia_valid = ATTR_MODE;
1267 nfs_begin_data_update(dir);
1268 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
1269 nfs_end_data_update(dir);
1272 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1282 * See comments for nfs_proc_create regarding failed operations.
1284 static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1289 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
1290 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1292 attr.ia_valid = ATTR_MODE;
1293 attr.ia_mode = mode | S_IFDIR;
1296 nfs_begin_data_update(dir);
1297 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
1298 nfs_end_data_update(dir);
1301 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1310 static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1314 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
1315 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
1318 nfs_begin_data_update(dir);
1319 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
1320 /* Ensure the VFS deletes this inode */
1321 if (error == 0 && dentry->d_inode != NULL)
1322 clear_nlink(dentry->d_inode);
1323 nfs_end_data_update(dir);
1329 static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
1331 static unsigned int sillycounter;
1332 const int fileidsize = sizeof(NFS_FILEID(dentry->d_inode))*2;
1333 const int countersize = sizeof(sillycounter)*2;
1334 const int slen = sizeof(".nfs")+fileidsize+countersize-1;
1337 struct dentry *sdentry;
1340 dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
1341 dentry->d_parent->d_name.name, dentry->d_name.name,
1342 atomic_read(&dentry->d_count));
1343 nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
1346 * We don't allow a dentry to be silly-renamed twice.
1349 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1352 sprintf(silly, ".nfs%*.*Lx",
1353 fileidsize, fileidsize,
1354 (unsigned long long)NFS_FILEID(dentry->d_inode));
1356 /* Return delegation in anticipation of the rename */
1357 nfs_inode_return_delegation(dentry->d_inode);
1361 char *suffix = silly + slen - countersize;
1365 sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
1367 dfprintk(VFS, "NFS: trying to rename %s to %s\n",
1368 dentry->d_name.name, silly);
1370 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
1372 * N.B. Better to return EBUSY here ... it could be
1373 * dangerous to delete the file while it's in use.
1375 if (IS_ERR(sdentry))
1377 } while(sdentry->d_inode != NULL); /* need negative lookup */
1379 qsilly.name = silly;
1380 qsilly.len = strlen(silly);
1381 nfs_begin_data_update(dir);
1382 if (dentry->d_inode) {
1383 nfs_begin_data_update(dentry->d_inode);
1384 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1386 nfs_mark_for_revalidate(dentry->d_inode);
1387 nfs_end_data_update(dentry->d_inode);
1389 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1391 nfs_end_data_update(dir);
1393 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1394 d_move(dentry, sdentry);
1395 error = nfs_async_unlink(dir, dentry);
1396 /* If we return 0 we don't unlink */
1404 * Remove a file after making sure there are no pending writes,
1405 * and after checking that the file has only one user.
1407 * We invalidate the attribute cache and free the inode prior to the operation
1408 * to avoid possible races if the server reuses the inode.
1410 static int nfs_safe_remove(struct dentry *dentry)
1412 struct inode *dir = dentry->d_parent->d_inode;
1413 struct inode *inode = dentry->d_inode;
1416 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1417 dentry->d_parent->d_name.name, dentry->d_name.name);
1419 /* If the dentry was sillyrenamed, we simply call d_delete() */
1420 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1425 nfs_begin_data_update(dir);
1426 if (inode != NULL) {
1427 nfs_inode_return_delegation(inode);
1428 nfs_begin_data_update(inode);
1429 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1430 /* The VFS may want to delete this inode */
1433 nfs_mark_for_revalidate(inode);
1434 nfs_end_data_update(inode);
1436 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1437 nfs_end_data_update(dir);
1442 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1443 * belongs to an active ".nfs..." file and we return -EBUSY.
1445 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1447 static int nfs_unlink(struct inode *dir, struct dentry *dentry)
1450 int need_rehash = 0;
1452 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1453 dir->i_ino, dentry->d_name.name);
1456 spin_lock(&dcache_lock);
1457 spin_lock(&dentry->d_lock);
1458 if (atomic_read(&dentry->d_count) > 1) {
1459 spin_unlock(&dentry->d_lock);
1460 spin_unlock(&dcache_lock);
1461 /* Start asynchronous writeout of the inode */
1462 write_inode_now(dentry->d_inode, 0);
1463 error = nfs_sillyrename(dir, dentry);
1467 if (!d_unhashed(dentry)) {
1471 spin_unlock(&dentry->d_lock);
1472 spin_unlock(&dcache_lock);
1473 error = nfs_safe_remove(dentry);
1475 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1476 } else if (need_rehash)
1483 * To create a symbolic link, most file systems instantiate a new inode,
1484 * add a page to it containing the path, then write it out to the disk
1485 * using prepare_write/commit_write.
1487 * Unfortunately the NFS client can't create the in-core inode first
1488 * because it needs a file handle to create an in-core inode (see
1489 * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the
1490 * symlink request has completed on the server.
1492 * So instead we allocate a raw page, copy the symname into it, then do
1493 * the SYMLINK request with the page as the buffer. If it succeeds, we
1494 * now have a new file handle and can instantiate an in-core NFS inode
1495 * and move the raw page into its mapping.
1497 static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1499 struct pagevec lru_pvec;
1503 unsigned int pathlen = strlen(symname);
1506 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1507 dir->i_ino, dentry->d_name.name, symname);
1509 if (pathlen > PAGE_SIZE)
1510 return -ENAMETOOLONG;
1512 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1513 attr.ia_valid = ATTR_MODE;
1517 page = alloc_page(GFP_HIGHUSER);
1523 kaddr = kmap_atomic(page, KM_USER0);
1524 memcpy(kaddr, symname, pathlen);
1525 if (pathlen < PAGE_SIZE)
1526 memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen);
1527 kunmap_atomic(kaddr, KM_USER0);
1529 nfs_begin_data_update(dir);
1530 error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr);
1531 nfs_end_data_update(dir);
1533 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n",
1534 dir->i_sb->s_id, dir->i_ino,
1535 dentry->d_name.name, symname, error);
1543 * No big deal if we can't add this page to the page cache here.
1544 * READLINK will get the missing page from the server if needed.
1546 pagevec_init(&lru_pvec, 0);
1547 if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0,
1549 pagevec_add(&lru_pvec, page);
1550 pagevec_lru_add(&lru_pvec);
1551 SetPageUptodate(page);
1561 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1563 struct inode *inode = old_dentry->d_inode;
1566 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
1567 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1568 dentry->d_parent->d_name.name, dentry->d_name.name);
1571 nfs_begin_data_update(dir);
1572 nfs_begin_data_update(inode);
1573 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1575 atomic_inc(&inode->i_count);
1576 d_instantiate(dentry, inode);
1578 nfs_end_data_update(inode);
1579 nfs_end_data_update(dir);
1586 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
1587 * different file handle for the same inode after a rename (e.g. when
1588 * moving to a different directory). A fail-safe method to do so would
1589 * be to look up old_dir/old_name, create a link to new_dir/new_name and
1590 * rename the old file using the sillyrename stuff. This way, the original
1591 * file in old_dir will go away when the last process iput()s the inode.
1595 * It actually works quite well. One needs to have the possibility for
1596 * at least one ".nfs..." file in each directory the file ever gets
1597 * moved or linked to which happens automagically with the new
1598 * implementation that only depends on the dcache stuff instead of
1599 * using the inode layer
1601 * Unfortunately, things are a little more complicated than indicated
1602 * above. For a cross-directory move, we want to make sure we can get
1603 * rid of the old inode after the operation. This means there must be
1604 * no pending writes (if it's a file), and the use count must be 1.
1605 * If these conditions are met, we can drop the dentries before doing
1608 static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1609 struct inode *new_dir, struct dentry *new_dentry)
1611 struct inode *old_inode = old_dentry->d_inode;
1612 struct inode *new_inode = new_dentry->d_inode;
1613 struct dentry *dentry = NULL, *rehash = NULL;
1617 * To prevent any new references to the target during the rename,
1618 * we unhash the dentry and free the inode in advance.
1621 if (!d_unhashed(new_dentry)) {
1623 rehash = new_dentry;
1626 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
1627 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1628 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
1629 atomic_read(&new_dentry->d_count));
1632 * First check whether the target is busy ... we can't
1633 * safely do _any_ rename if the target is in use.
1635 * For files, make a copy of the dentry and then do a
1636 * silly-rename. If the silly-rename succeeds, the
1637 * copied dentry is hashed and becomes the new target.
1641 if (S_ISDIR(new_inode->i_mode)) {
1643 if (!S_ISDIR(old_inode->i_mode))
1645 } else if (atomic_read(&new_dentry->d_count) > 2) {
1647 /* copy the target dentry's name */
1648 dentry = d_alloc(new_dentry->d_parent,
1649 &new_dentry->d_name);
1653 /* silly-rename the existing target ... */
1654 err = nfs_sillyrename(new_dir, new_dentry);
1656 new_dentry = rehash = dentry;
1658 /* instantiate the replacement target */
1659 d_instantiate(new_dentry, NULL);
1660 } else if (atomic_read(&new_dentry->d_count) > 1)
1661 /* dentry still busy? */
1664 drop_nlink(new_inode);
1668 * ... prune child dentries and writebacks if needed.
1670 if (atomic_read(&old_dentry->d_count) > 1) {
1671 if (S_ISREG(old_inode->i_mode))
1672 nfs_wb_all(old_inode);
1673 shrink_dcache_parent(old_dentry);
1675 nfs_inode_return_delegation(old_inode);
1677 if (new_inode != NULL) {
1678 nfs_inode_return_delegation(new_inode);
1679 d_delete(new_dentry);
1682 nfs_begin_data_update(old_dir);
1683 nfs_begin_data_update(new_dir);
1684 nfs_begin_data_update(old_inode);
1685 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
1686 new_dir, &new_dentry->d_name);
1687 nfs_mark_for_revalidate(old_inode);
1688 nfs_end_data_update(old_inode);
1689 nfs_end_data_update(new_dir);
1690 nfs_end_data_update(old_dir);
1695 d_move(old_dentry, new_dentry);
1696 nfs_set_verifier(new_dentry,
1697 nfs_save_change_attribute(new_dir));
1700 /* new dentry created? */
1707 static DEFINE_SPINLOCK(nfs_access_lru_lock);
1708 static LIST_HEAD(nfs_access_lru_list);
1709 static atomic_long_t nfs_access_nr_entries;
1711 static void nfs_access_free_entry(struct nfs_access_entry *entry)
1713 put_rpccred(entry->cred);
1715 smp_mb__before_atomic_dec();
1716 atomic_long_dec(&nfs_access_nr_entries);
1717 smp_mb__after_atomic_dec();
1720 int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask)
1723 struct nfs_inode *nfsi;
1724 struct nfs_access_entry *cache;
1727 spin_lock(&nfs_access_lru_lock);
1728 list_for_each_entry(nfsi, &nfs_access_lru_list, access_cache_inode_lru) {
1729 struct inode *inode;
1731 if (nr_to_scan-- == 0)
1733 inode = igrab(&nfsi->vfs_inode);
1736 spin_lock(&inode->i_lock);
1737 if (list_empty(&nfsi->access_cache_entry_lru))
1738 goto remove_lru_entry;
1739 cache = list_entry(nfsi->access_cache_entry_lru.next,
1740 struct nfs_access_entry, lru);
1741 list_move(&cache->lru, &head);
1742 rb_erase(&cache->rb_node, &nfsi->access_cache);
1743 if (!list_empty(&nfsi->access_cache_entry_lru))
1744 list_move_tail(&nfsi->access_cache_inode_lru,
1745 &nfs_access_lru_list);
1748 list_del_init(&nfsi->access_cache_inode_lru);
1749 clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags);
1751 spin_unlock(&inode->i_lock);
1752 spin_unlock(&nfs_access_lru_lock);
1756 spin_unlock(&nfs_access_lru_lock);
1757 while (!list_empty(&head)) {
1758 cache = list_entry(head.next, struct nfs_access_entry, lru);
1759 list_del(&cache->lru);
1760 nfs_access_free_entry(cache);
1762 return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure;
1765 static void __nfs_access_zap_cache(struct inode *inode)
1767 struct nfs_inode *nfsi = NFS_I(inode);
1768 struct rb_root *root_node = &nfsi->access_cache;
1769 struct rb_node *n, *dispose = NULL;
1770 struct nfs_access_entry *entry;
1772 /* Unhook entries from the cache */
1773 while ((n = rb_first(root_node)) != NULL) {
1774 entry = rb_entry(n, struct nfs_access_entry, rb_node);
1775 rb_erase(n, root_node);
1776 list_del(&entry->lru);
1777 n->rb_left = dispose;
1780 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
1781 spin_unlock(&inode->i_lock);
1783 /* Now kill them all! */
1784 while (dispose != NULL) {
1786 dispose = n->rb_left;
1787 nfs_access_free_entry(rb_entry(n, struct nfs_access_entry, rb_node));
1791 void nfs_access_zap_cache(struct inode *inode)
1793 /* Remove from global LRU init */
1794 if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_FLAGS(inode))) {
1795 spin_lock(&nfs_access_lru_lock);
1796 list_del_init(&NFS_I(inode)->access_cache_inode_lru);
1797 spin_unlock(&nfs_access_lru_lock);
1800 spin_lock(&inode->i_lock);
1801 /* This will release the spinlock */
1802 __nfs_access_zap_cache(inode);
1805 static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred)
1807 struct rb_node *n = NFS_I(inode)->access_cache.rb_node;
1808 struct nfs_access_entry *entry;
1811 entry = rb_entry(n, struct nfs_access_entry, rb_node);
1813 if (cred < entry->cred)
1815 else if (cred > entry->cred)
1823 static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
1825 struct nfs_inode *nfsi = NFS_I(inode);
1826 struct nfs_access_entry *cache;
1829 spin_lock(&inode->i_lock);
1830 if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)
1832 cache = nfs_access_search_rbtree(inode, cred);
1835 if (!time_in_range(jiffies, cache->jiffies, cache->jiffies + NFS_ATTRTIMEO(inode)))
1837 res->jiffies = cache->jiffies;
1838 res->cred = cache->cred;
1839 res->mask = cache->mask;
1840 list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru);
1843 spin_unlock(&inode->i_lock);
1846 rb_erase(&cache->rb_node, &nfsi->access_cache);
1847 list_del(&cache->lru);
1848 spin_unlock(&inode->i_lock);
1849 nfs_access_free_entry(cache);
1852 /* This will release the spinlock */
1853 __nfs_access_zap_cache(inode);
1857 static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set)
1859 struct nfs_inode *nfsi = NFS_I(inode);
1860 struct rb_root *root_node = &nfsi->access_cache;
1861 struct rb_node **p = &root_node->rb_node;
1862 struct rb_node *parent = NULL;
1863 struct nfs_access_entry *entry;
1865 spin_lock(&inode->i_lock);
1866 while (*p != NULL) {
1868 entry = rb_entry(parent, struct nfs_access_entry, rb_node);
1870 if (set->cred < entry->cred)
1871 p = &parent->rb_left;
1872 else if (set->cred > entry->cred)
1873 p = &parent->rb_right;
1877 rb_link_node(&set->rb_node, parent, p);
1878 rb_insert_color(&set->rb_node, root_node);
1879 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
1880 spin_unlock(&inode->i_lock);
1883 rb_replace_node(parent, &set->rb_node, root_node);
1884 list_add_tail(&set->lru, &nfsi->access_cache_entry_lru);
1885 list_del(&entry->lru);
1886 spin_unlock(&inode->i_lock);
1887 nfs_access_free_entry(entry);
1890 static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
1892 struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL);
1895 RB_CLEAR_NODE(&cache->rb_node);
1896 cache->jiffies = set->jiffies;
1897 cache->cred = get_rpccred(set->cred);
1898 cache->mask = set->mask;
1900 nfs_access_add_rbtree(inode, cache);
1902 /* Update accounting */
1903 smp_mb__before_atomic_inc();
1904 atomic_long_inc(&nfs_access_nr_entries);
1905 smp_mb__after_atomic_inc();
1907 /* Add inode to global LRU list */
1908 if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_FLAGS(inode))) {
1909 spin_lock(&nfs_access_lru_lock);
1910 list_add_tail(&NFS_I(inode)->access_cache_inode_lru, &nfs_access_lru_list);
1911 spin_unlock(&nfs_access_lru_lock);
1915 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
1917 struct nfs_access_entry cache;
1920 status = nfs_access_get_cached(inode, cred, &cache);
1924 /* Be clever: ask server to check for all possible rights */
1925 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
1927 cache.jiffies = jiffies;
1928 status = NFS_PROTO(inode)->access(inode, &cache);
1931 nfs_access_add_cache(inode, &cache);
1933 if ((cache.mask & mask) == mask)
1938 static int nfs_open_permission_mask(int openflags)
1942 if (openflags & FMODE_READ)
1944 if (openflags & FMODE_WRITE)
1946 if (openflags & FMODE_EXEC)
1951 int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags)
1953 return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags));
1956 int nfs_permission(struct inode *inode, int mask, struct nameidata *nd)
1958 struct rpc_cred *cred;
1961 nfs_inc_stats(inode, NFSIOS_VFSACCESS);
1965 /* Is this sys_access() ? */
1966 if (nd != NULL && (nd->flags & LOOKUP_ACCESS))
1969 switch (inode->i_mode & S_IFMT) {
1973 /* NFSv4 has atomic_open... */
1974 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
1976 && (nd->flags & LOOKUP_OPEN))
1981 * Optimize away all write operations, since the server
1982 * will check permissions when we perform the op.
1984 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
1991 if (!NFS_PROTO(inode)->access)
1994 cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
1995 if (!IS_ERR(cred)) {
1996 res = nfs_do_access(inode, cred, mask);
1999 res = PTR_ERR(cred);
2002 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
2003 inode->i_sb->s_id, inode->i_ino, mask, res);
2006 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
2008 res = generic_permission(inode, mask, NULL);
2015 * version-control: t
2016 * kept-new-versions: 5