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>
35 #include "delegation.h"
37 #define NFS_PARANOIA 1
38 /* #define NFS_DEBUG_VERBOSE 1 */
40 static int nfs_opendir(struct inode *, struct file *);
41 static int nfs_readdir(struct file *, void *, filldir_t);
42 static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
43 static int nfs_cached_lookup(struct inode *, struct dentry *,
44 struct nfs_fh *, struct nfs_fattr *);
45 static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *);
46 static int nfs_mkdir(struct inode *, struct dentry *, int);
47 static int nfs_rmdir(struct inode *, struct dentry *);
48 static int nfs_unlink(struct inode *, struct dentry *);
49 static int nfs_symlink(struct inode *, struct dentry *, const char *);
50 static int nfs_link(struct dentry *, struct inode *, struct dentry *);
51 static int nfs_mknod(struct inode *, struct dentry *, int, dev_t);
52 static int nfs_rename(struct inode *, struct dentry *,
53 struct inode *, struct dentry *);
54 static int nfs_fsync_dir(struct file *, struct dentry *, int);
56 struct file_operations nfs_dir_operations = {
57 .read = generic_read_dir,
58 .readdir = nfs_readdir,
60 .release = nfs_release,
61 .fsync = nfs_fsync_dir,
64 struct inode_operations nfs_dir_inode_operations = {
69 .symlink = nfs_symlink,
74 .permission = nfs_permission,
75 .getattr = nfs_getattr,
76 .setattr = nfs_setattr,
81 static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
82 struct inode_operations nfs4_dir_inode_operations = {
84 .lookup = nfs_atomic_lookup,
87 .symlink = nfs_symlink,
92 .permission = nfs_permission,
93 .getattr = nfs_getattr,
94 .setattr = nfs_setattr,
97 #endif /* CONFIG_NFS_V4 */
103 nfs_opendir(struct inode *inode, struct file *filp)
108 /* Call generic open code in order to cache credentials */
110 res = nfs_open(inode, filp);
115 typedef u32 * (*decode_dirent_t)(u32 *, struct nfs_entry *, int);
119 unsigned long page_index;
122 struct nfs_entry *entry;
123 decode_dirent_t decode;
126 } nfs_readdir_descriptor_t;
128 /* Now we cache directories properly, by stuffing the dirent
129 * data directly in the page cache.
131 * Inode invalidation due to refresh etc. takes care of
132 * _everything_, no sloppy entry flushing logic, no extraneous
133 * copying, network direct to page cache, the way it was meant
136 * NOTE: Dirent information verification is done always by the
137 * page-in of the RPC reply, nowhere else, this simplies
138 * things substantially.
141 int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page)
143 struct file *file = desc->file;
144 struct inode *inode = file->f_dentry->d_inode;
145 struct rpc_cred *cred = nfs_file_cred(file);
146 unsigned long timestamp;
149 dfprintk(VFS, "NFS: nfs_readdir_filler() reading cookie %Lu into page %lu.\n", (long long)desc->entry->cookie, page->index);
153 error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->entry->cookie, page,
154 NFS_SERVER(inode)->dtsize, desc->plus);
156 /* We requested READDIRPLUS, but the server doesn't grok it */
157 if (error == -ENOTSUPP && desc->plus) {
158 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
159 NFS_FLAGS(inode) &= ~NFS_INO_ADVISE_RDPLUS;
165 SetPageUptodate(page);
166 NFS_FLAGS(inode) |= NFS_INO_INVALID_ATIME;
167 /* Ensure consistent page alignment of the data.
168 * Note: assumes we have exclusive access to this mapping either
169 * throught inode->i_sem or some other mechanism.
171 if (page->index == 0) {
172 invalidate_inode_pages(inode->i_mapping);
173 NFS_I(inode)->readdir_timestamp = timestamp;
180 nfs_zap_caches(inode);
186 int dir_decode(nfs_readdir_descriptor_t *desc)
189 p = desc->decode(p, desc->entry, desc->plus);
197 void dir_page_release(nfs_readdir_descriptor_t *desc)
200 page_cache_release(desc->page);
206 * Given a pointer to a buffer that has already been filled by a call
207 * to readdir, find the next entry.
209 * If the end of the buffer has been reached, return -EAGAIN, if not,
210 * return the offset within the buffer of the next entry to be
214 int find_dirent(nfs_readdir_descriptor_t *desc, struct page *page)
216 struct nfs_entry *entry = desc->entry;
220 while((status = dir_decode(desc)) == 0) {
221 dfprintk(VFS, "NFS: found cookie %Lu\n", (long long)entry->cookie);
222 if (entry->prev_cookie == desc->target)
224 if (loop_count++ > 200) {
229 dfprintk(VFS, "NFS: find_dirent() returns %d\n", status);
234 * Find the given page, and call find_dirent() in order to try to
235 * return the next entry.
238 int find_dirent_page(nfs_readdir_descriptor_t *desc)
240 struct inode *inode = desc->file->f_dentry->d_inode;
244 dfprintk(VFS, "NFS: find_dirent_page() searching directory page %ld\n", desc->page_index);
246 page = read_cache_page(inode->i_mapping, desc->page_index,
247 (filler_t *)nfs_readdir_filler, desc);
249 status = PTR_ERR(page);
252 if (!PageUptodate(page))
255 /* NOTE: Someone else may have changed the READDIRPLUS flag */
257 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
258 status = find_dirent(desc, page);
260 dir_page_release(desc);
262 dfprintk(VFS, "NFS: find_dirent_page() returns %d\n", status);
265 page_cache_release(page);
270 * Recurse through the page cache pages, and return a
271 * filled nfs_entry structure of the next directory entry if possible.
273 * The target for the search is 'desc->target'.
276 int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
281 dfprintk(VFS, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", (long long)desc->target);
283 res = find_dirent_page(desc);
286 /* Align to beginning of next page */
288 if (loop_count++ > 200) {
293 dfprintk(VFS, "NFS: readdir_search_pagecache() returned %d\n", res);
297 static unsigned int nfs_type2dtype[] = {
310 unsigned int nfs_type_to_d_type(enum nfs_ftype type)
312 return nfs_type2dtype[type];
316 * Once we've found the start of the dirent within a page: fill 'er up...
319 int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
322 struct file *file = desc->file;
323 struct nfs_entry *entry = desc->entry;
324 unsigned long fileid;
328 dfprintk(VFS, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n", (long long)desc->target);
331 unsigned d_type = DT_UNKNOWN;
332 /* Note: entry->prev_cookie contains the cookie for
333 * retrieving the current dirent on the server */
334 fileid = nfs_fileid_to_ino_t(entry->ino);
336 /* Use readdirplus info */
337 if (desc->plus && (entry->fattr->valid & NFS_ATTR_FATTR))
338 d_type = nfs_type_to_d_type(entry->fattr->type);
340 res = filldir(dirent, entry->name, entry->len,
341 entry->prev_cookie, fileid, d_type);
344 file->f_pos = desc->target = entry->cookie;
345 if (dir_decode(desc) != 0) {
349 if (loop_count++ > 200) {
354 dir_page_release(desc);
356 dfprintk(VFS, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", (long long)desc->target, res);
361 * If we cannot find a cookie in our cache, we suspect that this is
362 * because it points to a deleted file, so we ask the server to return
363 * whatever it thinks is the next entry. We then feed this to filldir.
364 * If all goes well, we should then be able to find our way round the
365 * cache on the next call to readdir_search_pagecache();
367 * NOTE: we cannot add the anonymous page to the pagecache because
368 * the data it contains might not be page aligned. Besides,
369 * we should already have a complete representation of the
370 * directory in the page cache by the time we get here.
373 int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
376 struct file *file = desc->file;
377 struct inode *inode = file->f_dentry->d_inode;
378 struct rpc_cred *cred = nfs_file_cred(file);
379 struct page *page = NULL;
382 dfprintk(VFS, "NFS: uncached_readdir() searching for cookie %Lu\n", (long long)desc->target);
384 page = alloc_page(GFP_HIGHUSER);
389 desc->error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->target,
391 NFS_SERVER(inode)->dtsize,
393 NFS_FLAGS(inode) |= NFS_INO_INVALID_ATIME;
395 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
396 if (desc->error >= 0) {
397 if ((status = dir_decode(desc)) == 0)
398 desc->entry->prev_cookie = desc->target;
404 status = nfs_do_filldir(desc, dirent, filldir);
406 /* Reset read descriptor so it searches the page cache from
407 * the start upon the next call to readdir_search_pagecache() */
408 desc->page_index = 0;
409 desc->entry->cookie = desc->entry->prev_cookie = 0;
410 desc->entry->eof = 0;
412 dfprintk(VFS, "NFS: uncached_readdir() returns %d\n", status);
415 dir_page_release(desc);
419 /* The file offset position is now represented as a true offset into the
420 * page cache as is the case in most of the other filesystems.
422 static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
424 struct dentry *dentry = filp->f_dentry;
425 struct inode *inode = dentry->d_inode;
426 nfs_readdir_descriptor_t my_desc,
428 struct nfs_entry my_entry;
430 struct nfs_fattr fattr;
435 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
442 * filp->f_pos points to the file offset in the page cache.
443 * but if the cache has meanwhile been zapped, we need to
444 * read from the last dirent to revalidate f_pos
447 memset(desc, 0, sizeof(*desc));
450 desc->target = filp->f_pos;
451 desc->decode = NFS_PROTO(inode)->decode_dirent;
452 desc->plus = NFS_USE_READDIRPLUS(inode);
454 my_entry.cookie = my_entry.prev_cookie = 0;
457 my_entry.fattr = &fattr;
458 desc->entry = &my_entry;
460 while(!desc->entry->eof) {
461 res = readdir_search_pagecache(desc);
462 if (res == -EBADCOOKIE) {
463 /* This means either end of directory */
464 if (desc->entry->cookie != desc->target) {
465 /* Or that the server has 'lost' a cookie */
466 res = uncached_readdir(desc, dirent, filldir);
473 if (res == -ETOOSMALL && desc->plus) {
474 NFS_FLAGS(inode) &= ~NFS_INO_ADVISE_RDPLUS;
475 nfs_zap_caches(inode);
477 desc->entry->eof = 0;
483 res = nfs_do_filldir(desc, dirent, filldir);
498 * All directory operations under NFS are synchronous, so fsync()
499 * is a dummy operation.
501 int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync)
507 * A check for whether or not the parent directory has changed.
508 * In the case it has, we assume that the dentries are untrustworthy
509 * and may need to be looked up again.
511 static inline int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
515 if ((NFS_FLAGS(dir) & NFS_INO_INVALID_ATTR) != 0
516 || nfs_attribute_timeout(dir))
518 return nfs_verify_change_attribute(dir, (unsigned long)dentry->d_fsdata);
521 static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
523 dentry->d_fsdata = (void *)verf;
527 * Whenever an NFS operation succeeds, we know that the dentry
528 * is valid, so we update the revalidation timestamp.
530 static inline void nfs_renew_times(struct dentry * dentry)
532 dentry->d_time = jiffies;
536 int nfs_lookup_verify_inode(struct inode *inode, int isopen)
538 struct nfs_server *server = NFS_SERVER(inode);
540 if (isopen && !(server->flags & NFS_MOUNT_NOCTO))
541 return __nfs_revalidate_inode(server, inode);
542 return nfs_revalidate_inode(server, inode);
546 * We judge how long we want to trust negative
547 * dentries by looking at the parent inode mtime.
549 * If parent mtime has changed, we revalidate, else we wait for a
550 * period corresponding to the parent's attribute cache timeout value.
553 int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
554 struct nameidata *nd)
560 /* Don't revalidate a negative dentry if we're creating a new file */
561 if ((ndflags & LOOKUP_CREATE) && !(ndflags & LOOKUP_CONTINUE))
563 return !nfs_check_verifier(dir, dentry);
567 * This is called every time the dcache has a lookup hit,
568 * and we should check whether we can really trust that
571 * NOTE! The hit can be a negative hit too, don't assume
574 * If the parent directory is seen to have changed, we throw out the
575 * cached dentry and do a new lookup.
577 static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
581 struct dentry *parent;
583 struct nfs_fh fhandle;
584 struct nfs_fattr fattr;
585 unsigned long verifier;
588 parent = dget_parent(dentry);
590 dir = parent->d_inode;
591 inode = dentry->d_inode;
593 if (nd && !(nd->flags & LOOKUP_CONTINUE) && (nd->flags & LOOKUP_OPEN))
597 if (nfs_neg_need_reval(dir, dentry, nd))
602 if (is_bad_inode(inode)) {
603 dfprintk(VFS, "nfs_lookup_validate: %s/%s has dud inode\n",
604 dentry->d_parent->d_name.name, dentry->d_name.name);
608 /* Revalidate parent directory attribute cache */
609 nfs_revalidate_inode(NFS_SERVER(dir), dir);
611 /* Force a full look up iff the parent directory has changed */
612 if (nfs_check_verifier(dir, dentry)) {
613 if (nfs_lookup_verify_inode(inode, isopen))
619 * Note: we're not holding inode->i_sem and so may be racing with
620 * operations that change the directory. We therefore save the
621 * change attribute *before* we do the RPC call.
623 verifier = nfs_save_change_attribute(dir);
624 error = nfs_cached_lookup(dir, dentry, &fhandle, &fattr);
626 if (nfs_compare_fh(NFS_FH(inode), &fhandle))
628 if (nfs_lookup_verify_inode(inode, isopen))
630 goto out_valid_renew;
633 if (NFS_STALE(inode))
636 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
639 if (nfs_compare_fh(NFS_FH(inode), &fhandle))
641 if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
645 nfs_renew_times(dentry);
646 nfs_set_verifier(dentry, verifier);
655 if (inode && S_ISDIR(inode->i_mode)) {
656 /* Purge readdir caches. */
657 nfs_zap_caches(inode);
658 /* If we have submounts, don't unhash ! */
659 if (have_submounts(dentry))
661 shrink_dcache_parent(dentry);
670 * This is called from dput() when d_count is going to 0.
672 static int nfs_dentry_delete(struct dentry *dentry)
674 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
675 dentry->d_parent->d_name.name, dentry->d_name.name,
678 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
679 /* Unhash it, so that ->d_iput() would be called */
682 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
683 /* Unhash it, so that ancestors of killed async unlink
684 * files will be cleaned up during umount */
692 * Called when the dentry loses inode.
693 * We use it to clean up silly-renamed files.
695 static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
697 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
700 nfs_complete_unlink(dentry);
703 /* When creating a negative dentry, we want to renew d_time */
704 nfs_renew_times(dentry);
708 struct dentry_operations nfs_dentry_operations = {
709 .d_revalidate = nfs_lookup_revalidate,
710 .d_delete = nfs_dentry_delete,
711 .d_iput = nfs_dentry_iput,
715 int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
717 if (NFS_PROTO(dir)->version == 2)
719 if (!nd || (nd->flags & LOOKUP_CONTINUE) || !(nd->flags & LOOKUP_CREATE))
721 return (nd->intent.open.flags & O_EXCL) != 0;
724 static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
726 struct inode *inode = NULL;
728 struct nfs_fh fhandle;
729 struct nfs_fattr fattr;
731 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
732 dentry->d_parent->d_name.name, dentry->d_name.name);
734 error = -ENAMETOOLONG;
735 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
739 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
742 /* Revalidate parent directory attribute cache */
743 nfs_revalidate_inode(NFS_SERVER(dir), dir);
745 /* If we're doing an exclusive create, optimize away the lookup */
746 if (nfs_is_exclusive_create(dir, nd))
749 error = nfs_cached_lookup(dir, dentry, &fhandle, &fattr);
751 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name,
753 if (error == -ENOENT)
759 inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
764 d_add(dentry, inode);
765 nfs_renew_times(dentry);
766 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
771 return ERR_PTR(error);
775 static int nfs_open_revalidate(struct dentry *, struct nameidata *);
777 struct dentry_operations nfs4_dentry_operations = {
778 .d_revalidate = nfs_open_revalidate,
779 .d_delete = nfs_dentry_delete,
780 .d_iput = nfs_dentry_iput,
783 static int is_atomic_open(struct inode *dir, struct nameidata *nd)
787 /* Check that we are indeed trying to open this file */
788 if ((nd->flags & LOOKUP_CONTINUE) || !(nd->flags & LOOKUP_OPEN))
790 /* NFS does not (yet) have a stateful open for directories */
791 if (nd->flags & LOOKUP_DIRECTORY)
793 /* Are we trying to write to a read only partition? */
794 if (IS_RDONLY(dir) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE)))
799 static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
801 struct inode *inode = NULL;
804 /* Check that we are indeed trying to open this file */
805 if (!is_atomic_open(dir, nd))
808 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
809 error = -ENAMETOOLONG;
812 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
814 /* Let vfs_create() deal with O_EXCL */
815 if (nd->intent.open.flags & O_EXCL)
818 /* Open the file on the server */
820 /* Revalidate parent directory attribute cache */
821 nfs_revalidate_inode(NFS_SERVER(dir), dir);
823 if (nd->intent.open.flags & O_CREAT) {
824 nfs_begin_data_update(dir);
825 inode = nfs4_atomic_open(dir, dentry, nd);
826 nfs_end_data_update(dir);
828 inode = nfs4_atomic_open(dir, dentry, nd);
831 error = PTR_ERR(inode);
833 /* Make a negative dentry */
837 /* This turned out not to be a regular file */
839 if (!(nd->intent.open.flags & O_NOFOLLOW))
848 d_add(dentry, inode);
849 nfs_renew_times(dentry);
850 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
853 return ERR_PTR(error);
855 return nfs_lookup(dir, dentry, nd);
858 static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
860 struct dentry *parent = NULL;
861 struct inode *inode = dentry->d_inode;
863 unsigned long verifier;
864 int openflags, ret = 0;
866 parent = dget_parent(dentry);
867 dir = parent->d_inode;
868 if (!is_atomic_open(dir, nd))
870 /* We can't create new files in nfs_open_revalidate(), so we
871 * optimize away revalidation of negative dentries.
875 /* NFS only supports OPEN on regular files */
876 if (!S_ISREG(inode->i_mode))
878 openflags = nd->intent.open.flags;
879 /* We cannot do exclusive creation on a positive dentry */
880 if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
882 /* We can't create new files, or truncate existing ones here */
883 openflags &= ~(O_CREAT|O_TRUNC);
886 * Note: we're not holding inode->i_sem and so may be racing with
887 * operations that change the directory. We therefore save the
888 * change attribute *before* we do the RPC call.
891 verifier = nfs_save_change_attribute(dir);
892 ret = nfs4_open_revalidate(dir, dentry, openflags);
894 nfs_set_verifier(dentry, verifier);
903 if (inode != NULL && nfs_have_delegation(inode, FMODE_READ))
905 return nfs_lookup_revalidate(dentry, nd);
907 #endif /* CONFIG_NFSV4 */
910 int find_dirent_name(nfs_readdir_descriptor_t *desc, struct page *page, struct dentry *dentry)
912 struct nfs_entry *entry = desc->entry;
915 while((status = dir_decode(desc)) == 0) {
916 if (entry->len != dentry->d_name.len)
918 if (memcmp(entry->name, dentry->d_name.name, entry->len))
920 if (!(entry->fattr->valid & NFS_ATTR_FATTR))
928 * Use the cached Readdirplus results in order to avoid a LOOKUP call
929 * whenever we believe that the parent directory has not changed.
931 * We assume that any file creation/rename changes the directory mtime.
932 * As this results in a page cache invalidation whenever it occurs,
933 * we don't require any other tests for cache coherency.
936 int nfs_cached_lookup(struct inode *dir, struct dentry *dentry,
937 struct nfs_fh *fh, struct nfs_fattr *fattr)
939 nfs_readdir_descriptor_t desc;
940 struct nfs_server *server;
941 struct nfs_entry entry;
943 unsigned long timestamp;
946 if (!NFS_USE_READDIRPLUS(dir))
948 server = NFS_SERVER(dir);
949 /* Don't use readdirplus unless the cache is stable */
950 if ((server->flags & NFS_MOUNT_NOAC) != 0
951 || nfs_caches_unstable(dir)
952 || nfs_attribute_timeout(dir))
954 if ((NFS_FLAGS(dir) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA)) != 0)
956 timestamp = NFS_I(dir)->readdir_timestamp;
961 desc.decode = NFS_PROTO(dir)->decode_dirent;
966 for(;(page = find_get_page(dir->i_mapping, desc.page_index)); desc.page_index++) {
969 if (PageUptodate(page)) {
970 void * kaddr = kmap_atomic(page, KM_USER0);
972 res = find_dirent_name(&desc, page, dentry);
973 kunmap_atomic(kaddr, KM_USER0);
975 page_cache_release(page);
984 fattr->timestamp = timestamp;
989 * Code common to create, mkdir, and mknod.
991 static int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
992 struct nfs_fattr *fattr)
997 /* We may have been initialized further down */
1000 if (fhandle->size == 0) {
1001 struct inode *dir = dentry->d_parent->d_inode;
1002 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
1006 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1007 struct nfs_server *server = NFS_SB(dentry->d_sb);
1008 error = server->rpc_ops->getattr(server, fhandle, fattr);
1012 inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
1014 d_instantiate(dentry, inode);
1015 nfs_renew_times(dentry);
1016 nfs_set_verifier(dentry, nfs_save_change_attribute(dentry->d_parent->d_inode));
1026 * Following a failed create operation, we drop the dentry rather
1027 * than retain a negative dentry. This avoids a problem in the event
1028 * that the operation succeeded on the server, but an error in the
1029 * reply path made it appear to have failed.
1031 static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
1032 struct nameidata *nd)
1035 struct inode *inode;
1039 dfprintk(VFS, "NFS: create(%s/%ld, %s\n", dir->i_sb->s_id,
1040 dir->i_ino, dentry->d_name.name);
1042 attr.ia_mode = mode;
1043 attr.ia_valid = ATTR_MODE;
1045 if (nd && (nd->flags & LOOKUP_CREATE))
1046 open_flags = nd->intent.open.flags;
1049 * The 0 argument passed into the create function should one day
1050 * contain the O_EXCL flag if requested. This allows NFSv3 to
1051 * select the appropriate create strategy. Currently open_namei
1052 * does not pass the create flags.
1055 nfs_begin_data_update(dir);
1056 inode = NFS_PROTO(dir)->create(dir, &dentry->d_name, &attr, open_flags);
1057 nfs_end_data_update(dir);
1058 if (!IS_ERR(inode)) {
1059 d_instantiate(dentry, inode);
1060 nfs_renew_times(dentry);
1061 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1064 error = PTR_ERR(inode);
1072 * See comments for nfs_proc_create regarding failed operations.
1075 nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1078 struct nfs_fattr fattr;
1079 struct nfs_fh fhandle;
1082 dfprintk(VFS, "NFS: mknod(%s/%ld, %s\n", dir->i_sb->s_id,
1083 dir->i_ino, dentry->d_name.name);
1085 if (!new_valid_dev(rdev))
1088 attr.ia_mode = mode;
1089 attr.ia_valid = ATTR_MODE;
1092 nfs_begin_data_update(dir);
1093 error = NFS_PROTO(dir)->mknod(dir, &dentry->d_name, &attr, rdev,
1095 nfs_end_data_update(dir);
1097 error = nfs_instantiate(dentry, &fhandle, &fattr);
1105 * See comments for nfs_proc_create regarding failed operations.
1107 static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1110 struct nfs_fattr fattr;
1111 struct nfs_fh fhandle;
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;
1123 * Always drop the dentry, we can't always depend on
1124 * the fattr returned by the server (AIX seems to be
1125 * broken). We're better off doing another lookup than
1126 * depending on potentially bogus information.
1130 nfs_begin_data_update(dir);
1131 error = NFS_PROTO(dir)->mkdir(dir, &dentry->d_name, &attr, &fhandle,
1133 nfs_end_data_update(dir);
1135 error = nfs_instantiate(dentry, &fhandle, &fattr);
1142 static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1146 dfprintk(VFS, "NFS: rmdir(%s/%ld, %s\n", dir->i_sb->s_id,
1147 dir->i_ino, dentry->d_name.name);
1150 nfs_begin_data_update(dir);
1151 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
1152 /* Ensure the VFS deletes this inode */
1153 if (error == 0 && dentry->d_inode != NULL)
1154 dentry->d_inode->i_nlink = 0;
1155 nfs_end_data_update(dir);
1161 static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
1163 static unsigned int sillycounter;
1164 const int i_inosize = sizeof(dir->i_ino)*2;
1165 const int countersize = sizeof(sillycounter)*2;
1166 const int slen = strlen(".nfs") + i_inosize + countersize;
1169 struct dentry *sdentry;
1172 dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
1173 dentry->d_parent->d_name.name, dentry->d_name.name,
1174 atomic_read(&dentry->d_count));
1177 if (!dentry->d_inode)
1178 printk("NFS: silly-renaming %s/%s, negative dentry??\n",
1179 dentry->d_parent->d_name.name, dentry->d_name.name);
1182 * We don't allow a dentry to be silly-renamed twice.
1185 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1188 sprintf(silly, ".nfs%*.*lx",
1189 i_inosize, i_inosize, dentry->d_inode->i_ino);
1193 char *suffix = silly + slen - countersize;
1197 sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
1199 dfprintk(VFS, "trying to rename %s to %s\n",
1200 dentry->d_name.name, silly);
1202 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
1204 * N.B. Better to return EBUSY here ... it could be
1205 * dangerous to delete the file while it's in use.
1207 if (IS_ERR(sdentry))
1209 } while(sdentry->d_inode != NULL); /* need negative lookup */
1211 qsilly.name = silly;
1212 qsilly.len = strlen(silly);
1213 nfs_begin_data_update(dir);
1214 if (dentry->d_inode) {
1215 nfs_begin_data_update(dentry->d_inode);
1216 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1218 nfs_end_data_update(dentry->d_inode);
1220 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1222 nfs_end_data_update(dir);
1224 nfs_renew_times(dentry);
1225 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1226 d_move(dentry, sdentry);
1227 error = nfs_async_unlink(dentry);
1228 /* If we return 0 we don't unlink */
1236 * Remove a file after making sure there are no pending writes,
1237 * and after checking that the file has only one user.
1239 * We invalidate the attribute cache and free the inode prior to the operation
1240 * to avoid possible races if the server reuses the inode.
1242 static int nfs_safe_remove(struct dentry *dentry)
1244 struct inode *dir = dentry->d_parent->d_inode;
1245 struct inode *inode = dentry->d_inode;
1248 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1249 dentry->d_parent->d_name.name, dentry->d_name.name);
1251 /* If the dentry was sillyrenamed, we simply call d_delete() */
1252 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1257 nfs_begin_data_update(dir);
1258 if (inode != NULL) {
1259 nfs_begin_data_update(inode);
1260 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1261 /* The VFS may want to delete this inode */
1264 nfs_end_data_update(inode);
1266 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1267 nfs_end_data_update(dir);
1272 /* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1273 * belongs to an active ".nfs..." file and we return -EBUSY.
1275 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1277 static int nfs_unlink(struct inode *dir, struct dentry *dentry)
1280 int need_rehash = 0;
1282 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1283 dir->i_ino, dentry->d_name.name);
1286 spin_lock(&dcache_lock);
1287 spin_lock(&dentry->d_lock);
1288 if (atomic_read(&dentry->d_count) > 1) {
1289 spin_unlock(&dentry->d_lock);
1290 spin_unlock(&dcache_lock);
1291 error = nfs_sillyrename(dir, dentry);
1295 if (!d_unhashed(dentry)) {
1299 spin_unlock(&dentry->d_lock);
1300 spin_unlock(&dcache_lock);
1301 error = nfs_safe_remove(dentry);
1303 nfs_renew_times(dentry);
1304 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1305 } else if (need_rehash)
1312 nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1315 struct nfs_fattr sym_attr;
1316 struct nfs_fh sym_fh;
1317 struct qstr qsymname;
1320 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1321 dir->i_ino, dentry->d_name.name, symname);
1324 if (dentry->d_inode)
1325 printk("nfs_proc_symlink: %s/%s not negative!\n",
1326 dentry->d_parent->d_name.name, dentry->d_name.name);
1329 * Fill in the sattr for the call.
1330 * Note: SunOS 4.1.2 crashes if the mode isn't initialized!
1332 attr.ia_valid = ATTR_MODE;
1333 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1335 qsymname.name = symname;
1336 qsymname.len = strlen(symname);
1339 nfs_begin_data_update(dir);
1340 error = NFS_PROTO(dir)->symlink(dir, &dentry->d_name, &qsymname,
1341 &attr, &sym_fh, &sym_attr);
1342 nfs_end_data_update(dir);
1344 error = nfs_instantiate(dentry, &sym_fh, &sym_attr);
1346 if (error == -EEXIST)
1347 printk("nfs_proc_symlink: %s/%s already exists??\n",
1348 dentry->d_parent->d_name.name, dentry->d_name.name);
1356 nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1358 struct inode *inode = old_dentry->d_inode;
1361 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
1362 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1363 dentry->d_parent->d_name.name, dentry->d_name.name);
1366 * Drop the dentry in advance to force a new lookup.
1367 * Since nfs_proc_link doesn't return a file handle,
1368 * we can't use the existing dentry.
1373 nfs_begin_data_update(dir);
1374 nfs_begin_data_update(inode);
1375 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
1376 nfs_end_data_update(inode);
1377 nfs_end_data_update(dir);
1384 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
1385 * different file handle for the same inode after a rename (e.g. when
1386 * moving to a different directory). A fail-safe method to do so would
1387 * be to look up old_dir/old_name, create a link to new_dir/new_name and
1388 * rename the old file using the sillyrename stuff. This way, the original
1389 * file in old_dir will go away when the last process iput()s the inode.
1393 * It actually works quite well. One needs to have the possibility for
1394 * at least one ".nfs..." file in each directory the file ever gets
1395 * moved or linked to which happens automagically with the new
1396 * implementation that only depends on the dcache stuff instead of
1397 * using the inode layer
1399 * Unfortunately, things are a little more complicated than indicated
1400 * above. For a cross-directory move, we want to make sure we can get
1401 * rid of the old inode after the operation. This means there must be
1402 * no pending writes (if it's a file), and the use count must be 1.
1403 * If these conditions are met, we can drop the dentries before doing
1406 static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1407 struct inode *new_dir, struct dentry *new_dentry)
1409 struct inode *old_inode = old_dentry->d_inode;
1410 struct inode *new_inode = new_dentry->d_inode;
1411 struct dentry *dentry = NULL, *rehash = NULL;
1415 * To prevent any new references to the target during the rename,
1416 * we unhash the dentry and free the inode in advance.
1419 if (!d_unhashed(new_dentry)) {
1421 rehash = new_dentry;
1424 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
1425 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1426 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
1427 atomic_read(&new_dentry->d_count));
1430 * First check whether the target is busy ... we can't
1431 * safely do _any_ rename if the target is in use.
1433 * For files, make a copy of the dentry and then do a
1434 * silly-rename. If the silly-rename succeeds, the
1435 * copied dentry is hashed and becomes the new target.
1439 if (S_ISDIR(new_inode->i_mode))
1441 else if (atomic_read(&new_dentry->d_count) > 1) {
1443 /* copy the target dentry's name */
1444 dentry = d_alloc(new_dentry->d_parent,
1445 &new_dentry->d_name);
1449 /* silly-rename the existing target ... */
1450 err = nfs_sillyrename(new_dir, new_dentry);
1452 new_dentry = rehash = dentry;
1454 /* instantiate the replacement target */
1455 d_instantiate(new_dentry, NULL);
1458 /* dentry still busy? */
1459 if (atomic_read(&new_dentry->d_count) > 1) {
1461 printk("nfs_rename: target %s/%s busy, d_count=%d\n",
1462 new_dentry->d_parent->d_name.name,
1463 new_dentry->d_name.name,
1464 atomic_read(&new_dentry->d_count));
1472 * ... prune child dentries and writebacks if needed.
1474 if (atomic_read(&old_dentry->d_count) > 1) {
1475 nfs_wb_all(old_inode);
1476 shrink_dcache_parent(old_dentry);
1480 d_delete(new_dentry);
1482 nfs_begin_data_update(old_dir);
1483 nfs_begin_data_update(new_dir);
1484 nfs_begin_data_update(old_inode);
1485 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
1486 new_dir, &new_dentry->d_name);
1487 nfs_end_data_update(old_inode);
1488 nfs_end_data_update(new_dir);
1489 nfs_end_data_update(old_dir);
1494 if (!S_ISDIR(old_inode->i_mode))
1495 d_move(old_dentry, new_dentry);
1496 nfs_renew_times(new_dentry);
1497 nfs_set_verifier(new_dentry, nfs_save_change_attribute(new_dir));
1500 /* new dentry created? */
1507 int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
1509 struct nfs_access_entry *cache = &NFS_I(inode)->cache_access;
1511 if (cache->cred != cred
1512 || time_after(jiffies, cache->jiffies + NFS_ATTRTIMEO(inode))
1513 || (NFS_FLAGS(inode) & NFS_INO_INVALID_ATTR))
1515 memcpy(res, cache, sizeof(*res));
1519 void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
1521 struct nfs_access_entry *cache = &NFS_I(inode)->cache_access;
1523 if (cache->cred != set->cred) {
1525 put_rpccred(cache->cred);
1526 cache->cred = get_rpccred(set->cred);
1528 cache->jiffies = set->jiffies;
1529 cache->mask = set->mask;
1532 static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
1534 struct nfs_access_entry cache;
1537 status = nfs_access_get_cached(inode, cred, &cache);
1541 /* Be clever: ask server to check for all possible rights */
1542 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
1544 cache.jiffies = jiffies;
1545 status = NFS_PROTO(inode)->access(inode, &cache);
1548 nfs_access_add_cache(inode, &cache);
1550 if ((cache.mask & mask) == mask)
1555 int nfs_permission(struct inode *inode, int mask, struct nameidata *nd)
1557 struct rpc_cred *cred;
1558 int mode = inode->i_mode;
1563 if (mask & MAY_WRITE) {
1566 * Nobody gets write access to a read-only fs.
1569 if (IS_RDONLY(inode) &&
1570 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
1575 * Nobody gets write access to an immutable file.
1578 if (IS_IMMUTABLE(inode))
1581 /* Are we checking permissions on anything other than lookup/execute? */
1582 if ((mask & MAY_EXEC) == 0) {
1583 /* We only need to check permissions on file open() and access() */
1584 if (!nd || !(nd->flags & (LOOKUP_OPEN|LOOKUP_ACCESS)))
1586 /* NFSv4 has atomic_open... */
1587 if (NFS_PROTO(inode)->version > 3 && (nd->flags & LOOKUP_OPEN))
1593 if (!NFS_PROTO(inode)->access)
1596 cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
1597 res = nfs_do_access(inode, cred, mask);
1602 nfs_revalidate_inode(NFS_SERVER(inode), inode);
1603 res = vfs_permission(inode, mask);
1610 * version-control: t
1611 * kept-new-versions: 5