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/namei.h>
36 #include "delegation.h"
38 #define NFS_PARANOIA 1
39 /* #define NFS_DEBUG_VERBOSE 1 */
41 static int nfs_opendir(struct inode *, struct file *);
42 static int nfs_readdir(struct file *, void *, filldir_t);
43 static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
44 static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *);
45 static int nfs_mkdir(struct inode *, struct dentry *, int);
46 static int nfs_rmdir(struct inode *, struct dentry *);
47 static int nfs_unlink(struct inode *, struct dentry *);
48 static int nfs_symlink(struct inode *, struct dentry *, const char *);
49 static int nfs_link(struct dentry *, struct inode *, struct dentry *);
50 static int nfs_mknod(struct inode *, struct dentry *, int, dev_t);
51 static int nfs_rename(struct inode *, struct dentry *,
52 struct inode *, struct dentry *);
53 static int nfs_fsync_dir(struct file *, struct dentry *, int);
55 struct file_operations nfs_dir_operations = {
56 .read = generic_read_dir,
57 .readdir = nfs_readdir,
59 .release = nfs_release,
60 .fsync = nfs_fsync_dir,
63 struct inode_operations nfs_dir_inode_operations = {
68 .symlink = nfs_symlink,
73 .permission = nfs_permission,
74 .getattr = nfs_getattr,
75 .setattr = nfs_setattr,
79 struct inode_operations nfs3_dir_inode_operations = {
84 .symlink = nfs_symlink,
89 .permission = nfs_permission,
90 .getattr = nfs_getattr,
91 .setattr = nfs_setattr,
92 .listxattr = nfs3_listxattr,
93 .getxattr = nfs3_getxattr,
94 .setxattr = nfs3_setxattr,
95 .removexattr = nfs3_removexattr,
97 #endif /* CONFIG_NFS_V3 */
101 static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
102 struct inode_operations nfs4_dir_inode_operations = {
103 .create = nfs_create,
104 .lookup = nfs_atomic_lookup,
106 .unlink = nfs_unlink,
107 .symlink = nfs_symlink,
111 .rename = nfs_rename,
112 .permission = nfs_permission,
113 .getattr = nfs_getattr,
114 .setattr = nfs_setattr,
115 .getxattr = nfs4_getxattr,
116 .setxattr = nfs4_setxattr,
117 .listxattr = nfs4_listxattr,
120 #endif /* CONFIG_NFS_V4 */
126 nfs_opendir(struct inode *inode, struct file *filp)
131 /* Call generic open code in order to cache credentials */
133 res = nfs_open(inode, filp);
138 typedef u32 * (*decode_dirent_t)(u32 *, struct nfs_entry *, int);
142 unsigned long page_index;
145 struct nfs_entry *entry;
146 decode_dirent_t decode;
149 } nfs_readdir_descriptor_t;
151 /* Now we cache directories properly, by stuffing the dirent
152 * data directly in the page cache.
154 * Inode invalidation due to refresh etc. takes care of
155 * _everything_, no sloppy entry flushing logic, no extraneous
156 * copying, network direct to page cache, the way it was meant
159 * NOTE: Dirent information verification is done always by the
160 * page-in of the RPC reply, nowhere else, this simplies
161 * things substantially.
164 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page)
166 struct file *file = desc->file;
167 struct inode *inode = file->f_dentry->d_inode;
168 struct rpc_cred *cred = nfs_file_cred(file);
169 unsigned long timestamp;
172 dfprintk(VFS, "NFS: nfs_readdir_filler() reading cookie %Lu into page %lu.\n", (long long)desc->entry->cookie, page->index);
176 error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->entry->cookie, page,
177 NFS_SERVER(inode)->dtsize, desc->plus);
179 /* We requested READDIRPLUS, but the server doesn't grok it */
180 if (error == -ENOTSUPP && desc->plus) {
181 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
182 NFS_FLAGS(inode) &= ~NFS_INO_ADVISE_RDPLUS;
188 SetPageUptodate(page);
189 NFS_FLAGS(inode) |= NFS_INO_INVALID_ATIME;
190 /* Ensure consistent page alignment of the data.
191 * Note: assumes we have exclusive access to this mapping either
192 * through inode->i_sem or some other mechanism.
194 if (page->index == 0)
195 invalidate_inode_pages2_range(inode->i_mapping, PAGE_CACHE_SIZE, -1);
201 nfs_zap_caches(inode);
207 int dir_decode(nfs_readdir_descriptor_t *desc)
210 p = desc->decode(p, desc->entry, desc->plus);
218 void dir_page_release(nfs_readdir_descriptor_t *desc)
221 page_cache_release(desc->page);
227 * Given a pointer to a buffer that has already been filled by a call
228 * to readdir, find the next entry.
230 * If the end of the buffer has been reached, return -EAGAIN, if not,
231 * return the offset within the buffer of the next entry to be
235 int find_dirent(nfs_readdir_descriptor_t *desc, struct page *page)
237 struct nfs_entry *entry = desc->entry;
241 while((status = dir_decode(desc)) == 0) {
242 dfprintk(VFS, "NFS: found cookie %Lu\n", (long long)entry->cookie);
243 if (entry->prev_cookie == desc->target)
245 if (loop_count++ > 200) {
250 dfprintk(VFS, "NFS: find_dirent() returns %d\n", status);
255 * Find the given page, and call find_dirent() in order to try to
256 * return the next entry.
259 int find_dirent_page(nfs_readdir_descriptor_t *desc)
261 struct inode *inode = desc->file->f_dentry->d_inode;
265 dfprintk(VFS, "NFS: find_dirent_page() searching directory page %ld\n", desc->page_index);
267 page = read_cache_page(inode->i_mapping, desc->page_index,
268 (filler_t *)nfs_readdir_filler, desc);
270 status = PTR_ERR(page);
273 if (!PageUptodate(page))
276 /* NOTE: Someone else may have changed the READDIRPLUS flag */
278 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
279 status = find_dirent(desc, page);
281 dir_page_release(desc);
283 dfprintk(VFS, "NFS: find_dirent_page() returns %d\n", status);
286 page_cache_release(page);
291 * Recurse through the page cache pages, and return a
292 * filled nfs_entry structure of the next directory entry if possible.
294 * The target for the search is 'desc->target'.
297 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
302 dfprintk(VFS, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", (long long)desc->target);
304 res = find_dirent_page(desc);
307 /* Align to beginning of next page */
309 if (loop_count++ > 200) {
314 dfprintk(VFS, "NFS: readdir_search_pagecache() returned %d\n", res);
318 static inline unsigned int dt_type(struct inode *inode)
320 return (inode->i_mode >> 12) & 15;
323 static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc);
326 * Once we've found the start of the dirent within a page: fill 'er up...
329 int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
332 struct file *file = desc->file;
333 struct nfs_entry *entry = desc->entry;
334 struct dentry *dentry = NULL;
335 unsigned long fileid;
339 dfprintk(VFS, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n", (long long)desc->target);
342 unsigned d_type = DT_UNKNOWN;
343 /* Note: entry->prev_cookie contains the cookie for
344 * retrieving the current dirent on the server */
345 fileid = nfs_fileid_to_ino_t(entry->ino);
347 /* Get a dentry if we have one */
350 dentry = nfs_readdir_lookup(desc);
352 /* Use readdirplus info */
353 if (dentry != NULL && dentry->d_inode != NULL) {
354 d_type = dt_type(dentry->d_inode);
355 fileid = dentry->d_inode->i_ino;
358 res = filldir(dirent, entry->name, entry->len,
359 entry->prev_cookie, fileid, d_type);
362 file->f_pos = desc->target = entry->cookie;
363 if (dir_decode(desc) != 0) {
367 if (loop_count++ > 200) {
372 dir_page_release(desc);
375 dfprintk(VFS, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", (long long)desc->target, res);
380 * If we cannot find a cookie in our cache, we suspect that this is
381 * because it points to a deleted file, so we ask the server to return
382 * whatever it thinks is the next entry. We then feed this to filldir.
383 * If all goes well, we should then be able to find our way round the
384 * cache on the next call to readdir_search_pagecache();
386 * NOTE: we cannot add the anonymous page to the pagecache because
387 * the data it contains might not be page aligned. Besides,
388 * we should already have a complete representation of the
389 * directory in the page cache by the time we get here.
392 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
395 struct file *file = desc->file;
396 struct inode *inode = file->f_dentry->d_inode;
397 struct rpc_cred *cred = nfs_file_cred(file);
398 struct page *page = NULL;
401 dfprintk(VFS, "NFS: uncached_readdir() searching for cookie %Lu\n", (long long)desc->target);
403 page = alloc_page(GFP_HIGHUSER);
408 desc->error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->target,
410 NFS_SERVER(inode)->dtsize,
412 NFS_FLAGS(inode) |= NFS_INO_INVALID_ATIME;
414 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
415 if (desc->error >= 0) {
416 if ((status = dir_decode(desc)) == 0)
417 desc->entry->prev_cookie = desc->target;
423 status = nfs_do_filldir(desc, dirent, filldir);
425 /* Reset read descriptor so it searches the page cache from
426 * the start upon the next call to readdir_search_pagecache() */
427 desc->page_index = 0;
428 desc->entry->cookie = desc->entry->prev_cookie = 0;
429 desc->entry->eof = 0;
431 dfprintk(VFS, "NFS: uncached_readdir() returns %d\n", status);
434 dir_page_release(desc);
438 /* The file offset position is now represented as a true offset into the
439 * page cache as is the case in most of the other filesystems.
441 static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
443 struct dentry *dentry = filp->f_dentry;
444 struct inode *inode = dentry->d_inode;
445 nfs_readdir_descriptor_t my_desc,
447 struct nfs_entry my_entry;
449 struct nfs_fattr fattr;
454 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
461 * filp->f_pos points to the file offset in the page cache.
462 * but if the cache has meanwhile been zapped, we need to
463 * read from the last dirent to revalidate f_pos
466 memset(desc, 0, sizeof(*desc));
469 desc->target = filp->f_pos;
470 desc->decode = NFS_PROTO(inode)->decode_dirent;
471 desc->plus = NFS_USE_READDIRPLUS(inode);
473 my_entry.cookie = my_entry.prev_cookie = 0;
476 my_entry.fattr = &fattr;
477 desc->entry = &my_entry;
479 while(!desc->entry->eof) {
480 res = readdir_search_pagecache(desc);
481 if (res == -EBADCOOKIE) {
482 /* This means either end of directory */
483 if (desc->entry->cookie != desc->target) {
484 /* Or that the server has 'lost' a cookie */
485 res = uncached_readdir(desc, dirent, filldir);
492 if (res == -ETOOSMALL && desc->plus) {
493 NFS_FLAGS(inode) &= ~NFS_INO_ADVISE_RDPLUS;
494 nfs_zap_caches(inode);
496 desc->entry->eof = 0;
502 res = nfs_do_filldir(desc, dirent, filldir);
517 * All directory operations under NFS are synchronous, so fsync()
518 * is a dummy operation.
520 int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync)
526 * A check for whether or not the parent directory has changed.
527 * In the case it has, we assume that the dentries are untrustworthy
528 * and may need to be looked up again.
530 static inline int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
534 if ((NFS_FLAGS(dir) & NFS_INO_INVALID_ATTR) != 0
535 || nfs_attribute_timeout(dir))
537 return nfs_verify_change_attribute(dir, (unsigned long)dentry->d_fsdata);
540 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
542 dentry->d_fsdata = (void *)verf;
546 * Whenever an NFS operation succeeds, we know that the dentry
547 * is valid, so we update the revalidation timestamp.
549 static inline void nfs_renew_times(struct dentry * dentry)
551 dentry->d_time = jiffies;
555 * Return the intent data that applies to this particular path component
557 * Note that the current set of intents only apply to the very last
558 * component of the path.
559 * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
561 static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
563 if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
565 return nd->flags & mask;
569 * Inode and filehandle revalidation for lookups.
571 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
572 * or if the intent information indicates that we're about to open this
573 * particular file and the "nocto" mount flag is not set.
577 int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
579 struct nfs_server *server = NFS_SERVER(inode);
582 /* VFS wants an on-the-wire revalidation */
583 if (nd->flags & LOOKUP_REVAL)
585 /* This is an open(2) */
586 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
587 !(server->flags & NFS_MOUNT_NOCTO))
590 return nfs_revalidate_inode(server, inode);
592 return __nfs_revalidate_inode(server, inode);
596 * We judge how long we want to trust negative
597 * dentries by looking at the parent inode mtime.
599 * If parent mtime has changed, we revalidate, else we wait for a
600 * period corresponding to the parent's attribute cache timeout value.
603 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
604 struct nameidata *nd)
606 /* Don't revalidate a negative dentry if we're creating a new file */
607 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
609 return !nfs_check_verifier(dir, dentry);
613 * This is called every time the dcache has a lookup hit,
614 * and we should check whether we can really trust that
617 * NOTE! The hit can be a negative hit too, don't assume
620 * If the parent directory is seen to have changed, we throw out the
621 * cached dentry and do a new lookup.
623 static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
627 struct dentry *parent;
629 struct nfs_fh fhandle;
630 struct nfs_fattr fattr;
631 unsigned long verifier;
633 parent = dget_parent(dentry);
635 dir = parent->d_inode;
636 inode = dentry->d_inode;
639 if (nfs_neg_need_reval(dir, dentry, nd))
644 if (is_bad_inode(inode)) {
645 dfprintk(VFS, "nfs_lookup_validate: %s/%s has dud inode\n",
646 dentry->d_parent->d_name.name, dentry->d_name.name);
650 /* Revalidate parent directory attribute cache */
651 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
654 /* Force a full look up iff the parent directory has changed */
655 if (nfs_check_verifier(dir, dentry)) {
656 if (nfs_lookup_verify_inode(inode, nd))
661 if (NFS_STALE(inode))
664 verifier = nfs_save_change_attribute(dir);
665 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
668 if (nfs_compare_fh(NFS_FH(inode), &fhandle))
670 if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
673 nfs_renew_times(dentry);
674 nfs_set_verifier(dentry, verifier);
683 if (inode && S_ISDIR(inode->i_mode)) {
684 /* Purge readdir caches. */
685 nfs_zap_caches(inode);
686 /* If we have submounts, don't unhash ! */
687 if (have_submounts(dentry))
689 shrink_dcache_parent(dentry);
698 * This is called from dput() when d_count is going to 0.
700 static int nfs_dentry_delete(struct dentry *dentry)
702 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
703 dentry->d_parent->d_name.name, dentry->d_name.name,
706 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
707 /* Unhash it, so that ->d_iput() would be called */
710 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
711 /* Unhash it, so that ancestors of killed async unlink
712 * files will be cleaned up during umount */
720 * Called when the dentry loses inode.
721 * We use it to clean up silly-renamed files.
723 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
725 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
728 nfs_complete_unlink(dentry);
731 /* When creating a negative dentry, we want to renew d_time */
732 nfs_renew_times(dentry);
736 struct dentry_operations nfs_dentry_operations = {
737 .d_revalidate = nfs_lookup_revalidate,
738 .d_delete = nfs_dentry_delete,
739 .d_iput = nfs_dentry_iput,
743 * Use intent information to check whether or not we're going to do
744 * an O_EXCL create using this path component.
747 int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
749 if (NFS_PROTO(dir)->version == 2)
751 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0)
753 return (nd->intent.open.flags & O_EXCL) != 0;
756 static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
759 struct inode *inode = NULL;
761 struct nfs_fh fhandle;
762 struct nfs_fattr fattr;
764 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
765 dentry->d_parent->d_name.name, dentry->d_name.name);
767 res = ERR_PTR(-ENAMETOOLONG);
768 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
771 res = ERR_PTR(-ENOMEM);
772 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
775 /* Revalidate parent directory attribute cache */
776 error = nfs_revalidate_inode(NFS_SERVER(dir), dir);
778 res = ERR_PTR(error);
782 /* If we're doing an exclusive create, optimize away the lookup */
783 if (nfs_is_exclusive_create(dir, nd))
786 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
787 if (error == -ENOENT)
790 res = ERR_PTR(error);
793 res = ERR_PTR(-EACCES);
794 inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
798 res = d_add_unique(dentry, inode);
801 nfs_renew_times(dentry);
802 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
810 static int nfs_open_revalidate(struct dentry *, struct nameidata *);
812 struct dentry_operations nfs4_dentry_operations = {
813 .d_revalidate = nfs_open_revalidate,
814 .d_delete = nfs_dentry_delete,
815 .d_iput = nfs_dentry_iput,
819 * Use intent information to determine whether we need to substitute
820 * the NFSv4-style stateful OPEN for the LOOKUP call
822 static int is_atomic_open(struct inode *dir, struct nameidata *nd)
824 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
826 /* NFS does not (yet) have a stateful open for directories */
827 if (nd->flags & LOOKUP_DIRECTORY)
829 /* Are we trying to write to a read only partition? */
830 if (IS_RDONLY(dir) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE)))
835 static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
837 struct dentry *res = NULL;
838 struct inode *inode = NULL;
841 /* Check that we are indeed trying to open this file */
842 if (!is_atomic_open(dir, nd))
845 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
846 res = ERR_PTR(-ENAMETOOLONG);
849 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
851 /* Let vfs_create() deal with O_EXCL */
852 if (nd->intent.open.flags & O_EXCL)
855 /* Open the file on the server */
857 /* Revalidate parent directory attribute cache */
858 error = nfs_revalidate_inode(NFS_SERVER(dir), dir);
860 res = ERR_PTR(error);
864 if (nd->intent.open.flags & O_CREAT) {
865 nfs_begin_data_update(dir);
866 inode = nfs4_atomic_open(dir, dentry, nd);
867 nfs_end_data_update(dir);
869 inode = nfs4_atomic_open(dir, dentry, nd);
872 error = PTR_ERR(inode);
874 /* Make a negative dentry */
878 /* This turned out not to be a regular file */
880 if (!(nd->intent.open.flags & O_NOFOLLOW))
885 res = ERR_PTR(error);
890 res = d_add_unique(dentry, inode);
893 nfs_renew_times(dentry);
894 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
898 return nfs_lookup(dir, dentry, nd);
901 static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
903 struct dentry *parent = NULL;
904 struct inode *inode = dentry->d_inode;
906 unsigned long verifier;
907 int openflags, ret = 0;
909 parent = dget_parent(dentry);
910 dir = parent->d_inode;
911 if (!is_atomic_open(dir, nd))
913 /* We can't create new files in nfs_open_revalidate(), so we
914 * optimize away revalidation of negative dentries.
918 /* NFS only supports OPEN on regular files */
919 if (!S_ISREG(inode->i_mode))
921 openflags = nd->intent.open.flags;
922 /* We cannot do exclusive creation on a positive dentry */
923 if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
925 /* We can't create new files, or truncate existing ones here */
926 openflags &= ~(O_CREAT|O_TRUNC);
929 * Note: we're not holding inode->i_sem and so may be racing with
930 * operations that change the directory. We therefore save the
931 * change attribute *before* we do the RPC call.
934 verifier = nfs_save_change_attribute(dir);
935 ret = nfs4_open_revalidate(dir, dentry, openflags);
937 nfs_set_verifier(dentry, verifier);
946 if (inode != NULL && nfs_have_delegation(inode, FMODE_READ))
948 return nfs_lookup_revalidate(dentry, nd);
950 #endif /* CONFIG_NFSV4 */
952 static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc)
954 struct dentry *parent = desc->file->f_dentry;
955 struct inode *dir = parent->d_inode;
956 struct nfs_entry *entry = desc->entry;
957 struct dentry *dentry, *alias;
966 if (name.name[0] == '.' && name.name[1] == '.')
967 return dget_parent(parent);
970 if (name.name[0] == '.')
973 name.hash = full_name_hash(name.name, name.len);
974 dentry = d_lookup(parent, &name);
977 if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR))
979 /* Note: caller is already holding the dir->i_sem! */
980 dentry = d_alloc(parent, &name);
983 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
984 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
989 alias = d_add_unique(dentry, inode);
994 nfs_renew_times(dentry);
995 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1000 * Code common to create, mkdir, and mknod.
1002 int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1003 struct nfs_fattr *fattr)
1005 struct inode *inode;
1006 int error = -EACCES;
1008 /* We may have been initialized further down */
1009 if (dentry->d_inode)
1011 if (fhandle->size == 0) {
1012 struct inode *dir = dentry->d_parent->d_inode;
1013 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
1017 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1018 struct nfs_server *server = NFS_SB(dentry->d_sb);
1019 error = server->rpc_ops->getattr(server, fhandle, fattr);
1024 inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1027 d_instantiate(dentry, inode);
1035 * Following a failed create operation, we drop the dentry rather
1036 * than retain a negative dentry. This avoids a problem in the event
1037 * that the operation succeeded on the server, but an error in the
1038 * reply path made it appear to have failed.
1040 static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
1041 struct nameidata *nd)
1047 dfprintk(VFS, "NFS: create(%s/%ld, %s\n", dir->i_sb->s_id,
1048 dir->i_ino, dentry->d_name.name);
1050 attr.ia_mode = mode;
1051 attr.ia_valid = ATTR_MODE;
1053 if (nd && (nd->flags & LOOKUP_CREATE))
1054 open_flags = nd->intent.open.flags;
1057 nfs_begin_data_update(dir);
1058 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags);
1059 nfs_end_data_update(dir);
1062 nfs_renew_times(dentry);
1063 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1073 * See comments for nfs_proc_create regarding failed operations.
1076 nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1081 dfprintk(VFS, "NFS: mknod(%s/%ld, %s\n", dir->i_sb->s_id,
1082 dir->i_ino, dentry->d_name.name);
1084 if (!new_valid_dev(rdev))
1087 attr.ia_mode = mode;
1088 attr.ia_valid = ATTR_MODE;
1091 nfs_begin_data_update(dir);
1092 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
1093 nfs_end_data_update(dir);
1096 nfs_renew_times(dentry);
1097 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1107 * See comments for nfs_proc_create regarding failed operations.
1109 static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1114 dfprintk(VFS, "NFS: mkdir(%s/%ld, %s\n", dir->i_sb->s_id,
1115 dir->i_ino, dentry->d_name.name);
1117 attr.ia_valid = ATTR_MODE;
1118 attr.ia_mode = mode | S_IFDIR;
1121 nfs_begin_data_update(dir);
1122 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
1123 nfs_end_data_update(dir);
1126 nfs_renew_times(dentry);
1127 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1136 static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1140 dfprintk(VFS, "NFS: rmdir(%s/%ld, %s\n", dir->i_sb->s_id,
1141 dir->i_ino, dentry->d_name.name);
1144 nfs_begin_data_update(dir);
1145 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
1146 /* Ensure the VFS deletes this inode */
1147 if (error == 0 && dentry->d_inode != NULL)
1148 dentry->d_inode->i_nlink = 0;
1149 nfs_end_data_update(dir);
1155 static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
1157 static unsigned int sillycounter;
1158 const int i_inosize = sizeof(dir->i_ino)*2;
1159 const int countersize = sizeof(sillycounter)*2;
1160 const int slen = sizeof(".nfs") + i_inosize + countersize - 1;
1163 struct dentry *sdentry;
1166 dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
1167 dentry->d_parent->d_name.name, dentry->d_name.name,
1168 atomic_read(&dentry->d_count));
1171 if (!dentry->d_inode)
1172 printk("NFS: silly-renaming %s/%s, negative dentry??\n",
1173 dentry->d_parent->d_name.name, dentry->d_name.name);
1176 * We don't allow a dentry to be silly-renamed twice.
1179 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1182 sprintf(silly, ".nfs%*.*lx",
1183 i_inosize, i_inosize, dentry->d_inode->i_ino);
1187 char *suffix = silly + slen - countersize;
1191 sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
1193 dfprintk(VFS, "trying to rename %s to %s\n",
1194 dentry->d_name.name, silly);
1196 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
1198 * N.B. Better to return EBUSY here ... it could be
1199 * dangerous to delete the file while it's in use.
1201 if (IS_ERR(sdentry))
1203 } while(sdentry->d_inode != NULL); /* need negative lookup */
1205 qsilly.name = silly;
1206 qsilly.len = strlen(silly);
1207 nfs_begin_data_update(dir);
1208 if (dentry->d_inode) {
1209 nfs_begin_data_update(dentry->d_inode);
1210 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1212 nfs_end_data_update(dentry->d_inode);
1214 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1216 nfs_end_data_update(dir);
1218 nfs_renew_times(dentry);
1219 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1220 d_move(dentry, sdentry);
1221 error = nfs_async_unlink(dentry);
1222 /* If we return 0 we don't unlink */
1230 * Remove a file after making sure there are no pending writes,
1231 * and after checking that the file has only one user.
1233 * We invalidate the attribute cache and free the inode prior to the operation
1234 * to avoid possible races if the server reuses the inode.
1236 static int nfs_safe_remove(struct dentry *dentry)
1238 struct inode *dir = dentry->d_parent->d_inode;
1239 struct inode *inode = dentry->d_inode;
1242 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1243 dentry->d_parent->d_name.name, dentry->d_name.name);
1245 /* If the dentry was sillyrenamed, we simply call d_delete() */
1246 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1251 nfs_begin_data_update(dir);
1252 if (inode != NULL) {
1253 nfs_begin_data_update(inode);
1254 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1255 /* The VFS may want to delete this inode */
1258 nfs_end_data_update(inode);
1260 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1261 nfs_end_data_update(dir);
1266 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1267 * belongs to an active ".nfs..." file and we return -EBUSY.
1269 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1271 static int nfs_unlink(struct inode *dir, struct dentry *dentry)
1274 int need_rehash = 0;
1276 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1277 dir->i_ino, dentry->d_name.name);
1280 spin_lock(&dcache_lock);
1281 spin_lock(&dentry->d_lock);
1282 if (atomic_read(&dentry->d_count) > 1) {
1283 spin_unlock(&dentry->d_lock);
1284 spin_unlock(&dcache_lock);
1285 error = nfs_sillyrename(dir, dentry);
1289 if (!d_unhashed(dentry)) {
1293 spin_unlock(&dentry->d_lock);
1294 spin_unlock(&dcache_lock);
1295 error = nfs_safe_remove(dentry);
1297 nfs_renew_times(dentry);
1298 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1299 } else if (need_rehash)
1306 nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1309 struct nfs_fattr sym_attr;
1310 struct nfs_fh sym_fh;
1311 struct qstr qsymname;
1314 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1315 dir->i_ino, dentry->d_name.name, symname);
1318 if (dentry->d_inode)
1319 printk("nfs_proc_symlink: %s/%s not negative!\n",
1320 dentry->d_parent->d_name.name, dentry->d_name.name);
1323 * Fill in the sattr for the call.
1324 * Note: SunOS 4.1.2 crashes if the mode isn't initialized!
1326 attr.ia_valid = ATTR_MODE;
1327 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1329 qsymname.name = symname;
1330 qsymname.len = strlen(symname);
1333 nfs_begin_data_update(dir);
1334 error = NFS_PROTO(dir)->symlink(dir, &dentry->d_name, &qsymname,
1335 &attr, &sym_fh, &sym_attr);
1336 nfs_end_data_update(dir);
1338 error = nfs_instantiate(dentry, &sym_fh, &sym_attr);
1340 if (error == -EEXIST)
1341 printk("nfs_proc_symlink: %s/%s already exists??\n",
1342 dentry->d_parent->d_name.name, dentry->d_name.name);
1350 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1352 struct inode *inode = old_dentry->d_inode;
1355 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
1356 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1357 dentry->d_parent->d_name.name, dentry->d_name.name);
1360 * Drop the dentry in advance to force a new lookup.
1361 * Since nfs_proc_link doesn't return a file handle,
1362 * we can't use the existing dentry.
1367 nfs_begin_data_update(dir);
1368 nfs_begin_data_update(inode);
1369 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1370 nfs_end_data_update(inode);
1371 nfs_end_data_update(dir);
1378 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
1379 * different file handle for the same inode after a rename (e.g. when
1380 * moving to a different directory). A fail-safe method to do so would
1381 * be to look up old_dir/old_name, create a link to new_dir/new_name and
1382 * rename the old file using the sillyrename stuff. This way, the original
1383 * file in old_dir will go away when the last process iput()s the inode.
1387 * It actually works quite well. One needs to have the possibility for
1388 * at least one ".nfs..." file in each directory the file ever gets
1389 * moved or linked to which happens automagically with the new
1390 * implementation that only depends on the dcache stuff instead of
1391 * using the inode layer
1393 * Unfortunately, things are a little more complicated than indicated
1394 * above. For a cross-directory move, we want to make sure we can get
1395 * rid of the old inode after the operation. This means there must be
1396 * no pending writes (if it's a file), and the use count must be 1.
1397 * If these conditions are met, we can drop the dentries before doing
1400 static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1401 struct inode *new_dir, struct dentry *new_dentry)
1403 struct inode *old_inode = old_dentry->d_inode;
1404 struct inode *new_inode = new_dentry->d_inode;
1405 struct dentry *dentry = NULL, *rehash = NULL;
1409 * To prevent any new references to the target during the rename,
1410 * we unhash the dentry and free the inode in advance.
1413 if (!d_unhashed(new_dentry)) {
1415 rehash = new_dentry;
1418 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
1419 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1420 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
1421 atomic_read(&new_dentry->d_count));
1424 * First check whether the target is busy ... we can't
1425 * safely do _any_ rename if the target is in use.
1427 * For files, make a copy of the dentry and then do a
1428 * silly-rename. If the silly-rename succeeds, the
1429 * copied dentry is hashed and becomes the new target.
1433 if (S_ISDIR(new_inode->i_mode))
1435 else if (atomic_read(&new_dentry->d_count) > 2) {
1437 /* copy the target dentry's name */
1438 dentry = d_alloc(new_dentry->d_parent,
1439 &new_dentry->d_name);
1443 /* silly-rename the existing target ... */
1444 err = nfs_sillyrename(new_dir, new_dentry);
1446 new_dentry = rehash = dentry;
1448 /* instantiate the replacement target */
1449 d_instantiate(new_dentry, NULL);
1450 } else if (atomic_read(&new_dentry->d_count) > 1) {
1451 /* dentry still busy? */
1453 printk("nfs_rename: target %s/%s busy, d_count=%d\n",
1454 new_dentry->d_parent->d_name.name,
1455 new_dentry->d_name.name,
1456 atomic_read(&new_dentry->d_count));
1464 * ... prune child dentries and writebacks if needed.
1466 if (atomic_read(&old_dentry->d_count) > 1) {
1467 nfs_wb_all(old_inode);
1468 shrink_dcache_parent(old_dentry);
1472 d_delete(new_dentry);
1474 nfs_begin_data_update(old_dir);
1475 nfs_begin_data_update(new_dir);
1476 nfs_begin_data_update(old_inode);
1477 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
1478 new_dir, &new_dentry->d_name);
1479 nfs_end_data_update(old_inode);
1480 nfs_end_data_update(new_dir);
1481 nfs_end_data_update(old_dir);
1486 if (!S_ISDIR(old_inode->i_mode))
1487 d_move(old_dentry, new_dentry);
1488 nfs_renew_times(new_dentry);
1489 nfs_set_verifier(new_dentry, nfs_save_change_attribute(new_dir));
1492 /* new dentry created? */
1499 int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
1501 struct nfs_access_entry *cache = &NFS_I(inode)->cache_access;
1503 if (cache->cred != cred
1504 || time_after(jiffies, cache->jiffies + NFS_ATTRTIMEO(inode))
1505 || (NFS_FLAGS(inode) & NFS_INO_INVALID_ACCESS))
1507 memcpy(res, cache, sizeof(*res));
1511 void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
1513 struct nfs_access_entry *cache = &NFS_I(inode)->cache_access;
1515 if (cache->cred != set->cred) {
1517 put_rpccred(cache->cred);
1518 cache->cred = get_rpccred(set->cred);
1520 NFS_FLAGS(inode) &= ~NFS_INO_INVALID_ACCESS;
1521 cache->jiffies = set->jiffies;
1522 cache->mask = set->mask;
1525 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
1527 struct nfs_access_entry cache;
1530 status = nfs_access_get_cached(inode, cred, &cache);
1534 /* Be clever: ask server to check for all possible rights */
1535 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
1537 cache.jiffies = jiffies;
1538 status = NFS_PROTO(inode)->access(inode, &cache);
1541 nfs_access_add_cache(inode, &cache);
1543 if ((cache.mask & mask) == mask)
1548 int nfs_permission(struct inode *inode, int mask, struct nameidata *nd)
1550 struct rpc_cred *cred;
1555 /* Is this sys_access() ? */
1556 if (nd != NULL && (nd->flags & LOOKUP_ACCESS))
1559 switch (inode->i_mode & S_IFMT) {
1563 /* NFSv4 has atomic_open... */
1564 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
1566 && (nd->flags & LOOKUP_OPEN))
1571 * Optimize away all write operations, since the server
1572 * will check permissions when we perform the op.
1574 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
1581 if (!NFS_PROTO(inode)->access)
1584 cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
1585 if (!IS_ERR(cred)) {
1586 res = nfs_do_access(inode, cred, mask);
1589 res = PTR_ERR(cred);
1594 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
1596 res = generic_permission(inode, mask, NULL);
1603 * version-control: t
1604 * kept-new-versions: 5