blob: a23f3489416709288655f80603337f91ea94e398 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/nfs/dir.c
3 *
4 * Copyright (C) 1992 Rick Sladkey
5 *
6 * nfs directory handling functions
7 *
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
18 */
19
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>
27#include <linux/mm.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>
34
Trond Myklebust4ce79712005-06-22 17:16:21 +000035#include "nfs4_fs.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include "delegation.h"
Chuck Lever91d5b472006-03-20 13:44:14 -050037#include "iostat.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39#define NFS_PARANOIA 1
40/* #define NFS_DEBUG_VERBOSE 1 */
41
42static int nfs_opendir(struct inode *, struct file *);
43static int nfs_readdir(struct file *, void *, filldir_t);
44static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
45static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *);
46static int nfs_mkdir(struct inode *, struct dentry *, int);
47static int nfs_rmdir(struct inode *, struct dentry *);
48static int nfs_unlink(struct inode *, struct dentry *);
49static int nfs_symlink(struct inode *, struct dentry *, const char *);
50static int nfs_link(struct dentry *, struct inode *, struct dentry *);
51static int nfs_mknod(struct inode *, struct dentry *, int, dev_t);
52static int nfs_rename(struct inode *, struct dentry *,
53 struct inode *, struct dentry *);
54static int nfs_fsync_dir(struct file *, struct dentry *, int);
Trond Myklebustf0dd2132005-06-22 17:16:29 +000055static loff_t nfs_llseek_dir(struct file *, loff_t, int);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -080057const struct file_operations nfs_dir_operations = {
Trond Myklebustf0dd2132005-06-22 17:16:29 +000058 .llseek = nfs_llseek_dir,
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 .read = generic_read_dir,
60 .readdir = nfs_readdir,
61 .open = nfs_opendir,
62 .release = nfs_release,
63 .fsync = nfs_fsync_dir,
64};
65
66struct inode_operations nfs_dir_inode_operations = {
67 .create = nfs_create,
68 .lookup = nfs_lookup,
69 .link = nfs_link,
70 .unlink = nfs_unlink,
71 .symlink = nfs_symlink,
72 .mkdir = nfs_mkdir,
73 .rmdir = nfs_rmdir,
74 .mknod = nfs_mknod,
75 .rename = nfs_rename,
76 .permission = nfs_permission,
77 .getattr = nfs_getattr,
78 .setattr = nfs_setattr,
79};
80
Andreas Gruenbacherb7fa0552005-06-22 17:16:27 +000081#ifdef CONFIG_NFS_V3
82struct inode_operations nfs3_dir_inode_operations = {
83 .create = nfs_create,
84 .lookup = nfs_lookup,
85 .link = nfs_link,
86 .unlink = nfs_unlink,
87 .symlink = nfs_symlink,
88 .mkdir = nfs_mkdir,
89 .rmdir = nfs_rmdir,
90 .mknod = nfs_mknod,
91 .rename = nfs_rename,
92 .permission = nfs_permission,
93 .getattr = nfs_getattr,
94 .setattr = nfs_setattr,
95 .listxattr = nfs3_listxattr,
96 .getxattr = nfs3_getxattr,
97 .setxattr = nfs3_setxattr,
98 .removexattr = nfs3_removexattr,
99};
100#endif /* CONFIG_NFS_V3 */
101
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102#ifdef CONFIG_NFS_V4
103
104static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *);
105struct inode_operations nfs4_dir_inode_operations = {
106 .create = nfs_create,
107 .lookup = nfs_atomic_lookup,
108 .link = nfs_link,
109 .unlink = nfs_unlink,
110 .symlink = nfs_symlink,
111 .mkdir = nfs_mkdir,
112 .rmdir = nfs_rmdir,
113 .mknod = nfs_mknod,
114 .rename = nfs_rename,
115 .permission = nfs_permission,
116 .getattr = nfs_getattr,
117 .setattr = nfs_setattr,
J. Bruce Fields6b3b5492005-06-22 17:16:22 +0000118 .getxattr = nfs4_getxattr,
119 .setxattr = nfs4_setxattr,
120 .listxattr = nfs4_listxattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121};
122
123#endif /* CONFIG_NFS_V4 */
124
125/*
126 * Open file
127 */
128static int
129nfs_opendir(struct inode *inode, struct file *filp)
130{
131 int res = 0;
132
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500133 dfprintk(VFS, "NFS: opendir(%s/%ld)\n",
134 inode->i_sb->s_id, inode->i_ino);
135
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 lock_kernel();
137 /* Call generic open code in order to cache credentials */
138 if (!res)
139 res = nfs_open(inode, filp);
140 unlock_kernel();
141 return res;
142}
143
144typedef u32 * (*decode_dirent_t)(u32 *, struct nfs_entry *, int);
145typedef struct {
146 struct file *file;
147 struct page *page;
148 unsigned long page_index;
149 u32 *ptr;
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000150 u64 *dir_cookie;
151 loff_t current_index;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 struct nfs_entry *entry;
153 decode_dirent_t decode;
154 int plus;
155 int error;
156} nfs_readdir_descriptor_t;
157
158/* Now we cache directories properly, by stuffing the dirent
159 * data directly in the page cache.
160 *
161 * Inode invalidation due to refresh etc. takes care of
162 * _everything_, no sloppy entry flushing logic, no extraneous
163 * copying, network direct to page cache, the way it was meant
164 * to be.
165 *
166 * NOTE: Dirent information verification is done always by the
167 * page-in of the RPC reply, nowhere else, this simplies
168 * things substantially.
169 */
170static
171int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page)
172{
173 struct file *file = desc->file;
174 struct inode *inode = file->f_dentry->d_inode;
175 struct rpc_cred *cred = nfs_file_cred(file);
176 unsigned long timestamp;
177 int error;
178
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500179 dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n",
180 __FUNCTION__, (long long)desc->entry->cookie,
181 page->index);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 again:
184 timestamp = jiffies;
185 error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->entry->cookie, page,
186 NFS_SERVER(inode)->dtsize, desc->plus);
187 if (error < 0) {
188 /* We requested READDIRPLUS, but the server doesn't grok it */
189 if (error == -ENOTSUPP && desc->plus) {
190 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
Chuck Lever412d5822005-08-18 11:24:11 -0700191 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 desc->plus = 0;
193 goto again;
194 }
195 goto error;
196 }
197 SetPageUptodate(page);
Chuck Leverdc592502005-08-18 11:24:12 -0700198 spin_lock(&inode->i_lock);
Chuck Lever55296802005-08-18 11:24:09 -0700199 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
Chuck Leverdc592502005-08-18 11:24:12 -0700200 spin_unlock(&inode->i_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 /* Ensure consistent page alignment of the data.
202 * Note: assumes we have exclusive access to this mapping either
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800203 * through inode->i_mutex or some other mechanism.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 */
Trond Myklebusta656db92005-06-22 17:16:21 +0000205 if (page->index == 0)
206 invalidate_inode_pages2_range(inode->i_mapping, PAGE_CACHE_SIZE, -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 unlock_page(page);
208 return 0;
209 error:
210 SetPageError(page);
211 unlock_page(page);
212 nfs_zap_caches(inode);
213 desc->error = error;
214 return -EIO;
215}
216
217static inline
218int dir_decode(nfs_readdir_descriptor_t *desc)
219{
220 u32 *p = desc->ptr;
221 p = desc->decode(p, desc->entry, desc->plus);
222 if (IS_ERR(p))
223 return PTR_ERR(p);
224 desc->ptr = p;
225 return 0;
226}
227
228static inline
229void dir_page_release(nfs_readdir_descriptor_t *desc)
230{
231 kunmap(desc->page);
232 page_cache_release(desc->page);
233 desc->page = NULL;
234 desc->ptr = NULL;
235}
236
237/*
238 * Given a pointer to a buffer that has already been filled by a call
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000239 * to readdir, find the next entry with cookie '*desc->dir_cookie'.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 *
241 * If the end of the buffer has been reached, return -EAGAIN, if not,
242 * return the offset within the buffer of the next entry to be
243 * read.
244 */
245static inline
Olivier Galibert00a92642005-06-22 17:16:29 +0000246int find_dirent(nfs_readdir_descriptor_t *desc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247{
248 struct nfs_entry *entry = desc->entry;
249 int loop_count = 0,
250 status;
251
252 while((status = dir_decode(desc)) == 0) {
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500253 dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n",
254 __FUNCTION__, (unsigned long long)entry->cookie);
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000255 if (entry->prev_cookie == *desc->dir_cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 break;
257 if (loop_count++ > 200) {
258 loop_count = 0;
259 schedule();
260 }
261 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 return status;
263}
264
265/*
Olivier Galibert00a92642005-06-22 17:16:29 +0000266 * Given a pointer to a buffer that has already been filled by a call
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000267 * to readdir, find the entry at offset 'desc->file->f_pos'.
Olivier Galibert00a92642005-06-22 17:16:29 +0000268 *
269 * If the end of the buffer has been reached, return -EAGAIN, if not,
270 * return the offset within the buffer of the next entry to be
271 * read.
272 */
273static inline
274int find_dirent_index(nfs_readdir_descriptor_t *desc)
275{
276 struct nfs_entry *entry = desc->entry;
277 int loop_count = 0,
278 status;
279
280 for(;;) {
281 status = dir_decode(desc);
282 if (status)
283 break;
284
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500285 dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n",
286 (unsigned long long)entry->cookie, desc->current_index);
Olivier Galibert00a92642005-06-22 17:16:29 +0000287
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000288 if (desc->file->f_pos == desc->current_index) {
289 *desc->dir_cookie = entry->cookie;
Olivier Galibert00a92642005-06-22 17:16:29 +0000290 break;
291 }
292 desc->current_index++;
293 if (loop_count++ > 200) {
294 loop_count = 0;
295 schedule();
296 }
297 }
Olivier Galibert00a92642005-06-22 17:16:29 +0000298 return status;
299}
300
301/*
302 * Find the given page, and call find_dirent() or find_dirent_index in
303 * order to try to return the next entry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 */
305static inline
306int find_dirent_page(nfs_readdir_descriptor_t *desc)
307{
308 struct inode *inode = desc->file->f_dentry->d_inode;
309 struct page *page;
310 int status;
311
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500312 dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n",
313 __FUNCTION__, desc->page_index,
314 (long long) *desc->dir_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315
316 page = read_cache_page(inode->i_mapping, desc->page_index,
317 (filler_t *)nfs_readdir_filler, desc);
318 if (IS_ERR(page)) {
319 status = PTR_ERR(page);
320 goto out;
321 }
322 if (!PageUptodate(page))
323 goto read_error;
324
325 /* NOTE: Someone else may have changed the READDIRPLUS flag */
326 desc->page = page;
327 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000328 if (*desc->dir_cookie != 0)
Olivier Galibert00a92642005-06-22 17:16:29 +0000329 status = find_dirent(desc);
330 else
331 status = find_dirent_index(desc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 if (status < 0)
333 dir_page_release(desc);
334 out:
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500335 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336 return status;
337 read_error:
338 page_cache_release(page);
339 return -EIO;
340}
341
342/*
343 * Recurse through the page cache pages, and return a
344 * filled nfs_entry structure of the next directory entry if possible.
345 *
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000346 * The target for the search is '*desc->dir_cookie' if non-0,
347 * 'desc->file->f_pos' otherwise
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 */
349static inline
350int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
351{
352 int loop_count = 0;
353 int res;
354
Olivier Galibert00a92642005-06-22 17:16:29 +0000355 /* Always search-by-index from the beginning of the cache */
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000356 if (*desc->dir_cookie == 0) {
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500357 dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n",
358 (long long)desc->file->f_pos);
Olivier Galibert00a92642005-06-22 17:16:29 +0000359 desc->page_index = 0;
360 desc->entry->cookie = desc->entry->prev_cookie = 0;
361 desc->entry->eof = 0;
362 desc->current_index = 0;
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000363 } else
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500364 dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n",
365 (unsigned long long)*desc->dir_cookie);
Olivier Galibert00a92642005-06-22 17:16:29 +0000366
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 for (;;) {
368 res = find_dirent_page(desc);
369 if (res != -EAGAIN)
370 break;
371 /* Align to beginning of next page */
372 desc->page_index ++;
373 if (loop_count++ > 200) {
374 loop_count = 0;
375 schedule();
376 }
377 }
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500378
379 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 return res;
381}
382
383static inline unsigned int dt_type(struct inode *inode)
384{
385 return (inode->i_mode >> 12) & 15;
386}
387
388static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc);
389
390/*
391 * Once we've found the start of the dirent within a page: fill 'er up...
392 */
393static
394int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
395 filldir_t filldir)
396{
397 struct file *file = desc->file;
398 struct nfs_entry *entry = desc->entry;
399 struct dentry *dentry = NULL;
400 unsigned long fileid;
401 int loop_count = 0,
402 res;
403
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500404 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n",
405 (unsigned long long)entry->cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406
407 for(;;) {
408 unsigned d_type = DT_UNKNOWN;
409 /* Note: entry->prev_cookie contains the cookie for
410 * retrieving the current dirent on the server */
411 fileid = nfs_fileid_to_ino_t(entry->ino);
412
413 /* Get a dentry if we have one */
414 if (dentry != NULL)
415 dput(dentry);
416 dentry = nfs_readdir_lookup(desc);
417
418 /* Use readdirplus info */
419 if (dentry != NULL && dentry->d_inode != NULL) {
420 d_type = dt_type(dentry->d_inode);
421 fileid = dentry->d_inode->i_ino;
422 }
423
424 res = filldir(dirent, entry->name, entry->len,
Olivier Galibert00a92642005-06-22 17:16:29 +0000425 file->f_pos, fileid, d_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 if (res < 0)
427 break;
Olivier Galibert00a92642005-06-22 17:16:29 +0000428 file->f_pos++;
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000429 *desc->dir_cookie = entry->cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 if (dir_decode(desc) != 0) {
431 desc->page_index ++;
432 break;
433 }
434 if (loop_count++ > 200) {
435 loop_count = 0;
436 schedule();
437 }
438 }
439 dir_page_release(desc);
440 if (dentry != NULL)
441 dput(dentry);
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500442 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
443 (unsigned long long)*desc->dir_cookie, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 return res;
445}
446
447/*
448 * If we cannot find a cookie in our cache, we suspect that this is
449 * because it points to a deleted file, so we ask the server to return
450 * whatever it thinks is the next entry. We then feed this to filldir.
451 * If all goes well, we should then be able to find our way round the
452 * cache on the next call to readdir_search_pagecache();
453 *
454 * NOTE: we cannot add the anonymous page to the pagecache because
455 * the data it contains might not be page aligned. Besides,
456 * we should already have a complete representation of the
457 * directory in the page cache by the time we get here.
458 */
459static inline
460int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
461 filldir_t filldir)
462{
463 struct file *file = desc->file;
464 struct inode *inode = file->f_dentry->d_inode;
465 struct rpc_cred *cred = nfs_file_cred(file);
466 struct page *page = NULL;
467 int status;
468
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500469 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
470 (unsigned long long)*desc->dir_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471
472 page = alloc_page(GFP_HIGHUSER);
473 if (!page) {
474 status = -ENOMEM;
475 goto out;
476 }
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000477 desc->error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, *desc->dir_cookie,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 page,
479 NFS_SERVER(inode)->dtsize,
480 desc->plus);
Chuck Leverdc592502005-08-18 11:24:12 -0700481 spin_lock(&inode->i_lock);
Chuck Lever55296802005-08-18 11:24:09 -0700482 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
Chuck Leverdc592502005-08-18 11:24:12 -0700483 spin_unlock(&inode->i_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 desc->page = page;
485 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
486 if (desc->error >= 0) {
487 if ((status = dir_decode(desc)) == 0)
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000488 desc->entry->prev_cookie = *desc->dir_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 } else
490 status = -EIO;
491 if (status < 0)
492 goto out_release;
493
494 status = nfs_do_filldir(desc, dirent, filldir);
495
496 /* Reset read descriptor so it searches the page cache from
497 * the start upon the next call to readdir_search_pagecache() */
498 desc->page_index = 0;
499 desc->entry->cookie = desc->entry->prev_cookie = 0;
500 desc->entry->eof = 0;
501 out:
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500502 dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
503 __FUNCTION__, status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 return status;
505 out_release:
506 dir_page_release(desc);
507 goto out;
508}
509
Olivier Galibert00a92642005-06-22 17:16:29 +0000510/* The file offset position represents the dirent entry number. A
511 last cookie cache takes care of the common case of reading the
512 whole directory.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 */
514static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
515{
516 struct dentry *dentry = filp->f_dentry;
517 struct inode *inode = dentry->d_inode;
518 nfs_readdir_descriptor_t my_desc,
519 *desc = &my_desc;
520 struct nfs_entry my_entry;
521 struct nfs_fh fh;
522 struct nfs_fattr fattr;
523 long res;
524
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500525 dfprintk(VFS, "NFS: readdir(%s/%s) starting at cookie %Lu\n",
526 dentry->d_parent->d_name.name, dentry->d_name.name,
527 (long long)filp->f_pos);
Chuck Lever91d5b472006-03-20 13:44:14 -0500528 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
529
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 lock_kernel();
531
532 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
533 if (res < 0) {
534 unlock_kernel();
535 return res;
536 }
537
538 /*
Olivier Galibert00a92642005-06-22 17:16:29 +0000539 * filp->f_pos points to the dirent entry number.
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000540 * *desc->dir_cookie has the cookie for the next entry. We have
Olivier Galibert00a92642005-06-22 17:16:29 +0000541 * to either find the entry with the appropriate number or
542 * revalidate the cookie.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 */
544 memset(desc, 0, sizeof(*desc));
545
546 desc->file = filp;
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000547 desc->dir_cookie = &((struct nfs_open_context *)filp->private_data)->dir_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 desc->decode = NFS_PROTO(inode)->decode_dirent;
549 desc->plus = NFS_USE_READDIRPLUS(inode);
550
551 my_entry.cookie = my_entry.prev_cookie = 0;
552 my_entry.eof = 0;
553 my_entry.fh = &fh;
554 my_entry.fattr = &fattr;
Trond Myklebust0e574af2005-10-27 22:12:38 -0400555 nfs_fattr_init(&fattr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556 desc->entry = &my_entry;
557
558 while(!desc->entry->eof) {
559 res = readdir_search_pagecache(desc);
Olivier Galibert00a92642005-06-22 17:16:29 +0000560
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 if (res == -EBADCOOKIE) {
562 /* This means either end of directory */
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000563 if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 /* Or that the server has 'lost' a cookie */
565 res = uncached_readdir(desc, dirent, filldir);
566 if (res >= 0)
567 continue;
568 }
569 res = 0;
570 break;
571 }
572 if (res == -ETOOSMALL && desc->plus) {
Chuck Lever412d5822005-08-18 11:24:11 -0700573 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 nfs_zap_caches(inode);
575 desc->plus = 0;
576 desc->entry->eof = 0;
577 continue;
578 }
579 if (res < 0)
580 break;
581
582 res = nfs_do_filldir(desc, dirent, filldir);
583 if (res < 0) {
584 res = 0;
585 break;
586 }
587 }
588 unlock_kernel();
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500589 if (res > 0)
590 res = 0;
591 dfprintk(VFS, "NFS: readdir(%s/%s) returns %ld\n",
592 dentry->d_parent->d_name.name, dentry->d_name.name,
593 res);
594 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595}
596
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000597loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
598{
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800599 mutex_lock(&filp->f_dentry->d_inode->i_mutex);
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000600 switch (origin) {
601 case 1:
602 offset += filp->f_pos;
603 case 0:
604 if (offset >= 0)
605 break;
606 default:
607 offset = -EINVAL;
608 goto out;
609 }
610 if (offset != filp->f_pos) {
611 filp->f_pos = offset;
612 ((struct nfs_open_context *)filp->private_data)->dir_cookie = 0;
613 }
614out:
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800615 mutex_unlock(&filp->f_dentry->d_inode->i_mutex);
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000616 return offset;
617}
618
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619/*
620 * All directory operations under NFS are synchronous, so fsync()
621 * is a dummy operation.
622 */
623int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync)
624{
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500625 dfprintk(VFS, "NFS: fsync_dir(%s/%s) datasync %d\n",
626 dentry->d_parent->d_name.name, dentry->d_name.name,
627 datasync);
628
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 return 0;
630}
631
632/*
633 * A check for whether or not the parent directory has changed.
634 * In the case it has, we assume that the dentries are untrustworthy
635 * and may need to be looked up again.
636 */
637static inline int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
638{
639 if (IS_ROOT(dentry))
640 return 1;
Chuck Lever55296802005-08-18 11:24:09 -0700641 if ((NFS_I(dir)->cache_validity & NFS_INO_INVALID_ATTR) != 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 || nfs_attribute_timeout(dir))
643 return 0;
644 return nfs_verify_change_attribute(dir, (unsigned long)dentry->d_fsdata);
645}
646
647static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
648{
649 dentry->d_fsdata = (void *)verf;
650}
651
652/*
653 * Whenever an NFS operation succeeds, we know that the dentry
654 * is valid, so we update the revalidation timestamp.
655 */
656static inline void nfs_renew_times(struct dentry * dentry)
657{
658 dentry->d_time = jiffies;
659}
660
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400661/*
662 * Return the intent data that applies to this particular path component
663 *
664 * Note that the current set of intents only apply to the very last
665 * component of the path.
666 * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
667 */
668static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
669{
670 if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
671 return 0;
672 return nd->flags & mask;
673}
674
675/*
676 * Inode and filehandle revalidation for lookups.
677 *
678 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
679 * or if the intent information indicates that we're about to open this
680 * particular file and the "nocto" mount flag is not set.
681 *
682 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683static inline
684int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
685{
686 struct nfs_server *server = NFS_SERVER(inode);
687
688 if (nd != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689 /* VFS wants an on-the-wire revalidation */
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400690 if (nd->flags & LOOKUP_REVAL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 goto out_force;
692 /* This is an open(2) */
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400693 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 !(server->flags & NFS_MOUNT_NOCTO))
695 goto out_force;
696 }
697 return nfs_revalidate_inode(server, inode);
698out_force:
699 return __nfs_revalidate_inode(server, inode);
700}
701
702/*
703 * We judge how long we want to trust negative
704 * dentries by looking at the parent inode mtime.
705 *
706 * If parent mtime has changed, we revalidate, else we wait for a
707 * period corresponding to the parent's attribute cache timeout value.
708 */
709static inline
710int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
711 struct nameidata *nd)
712{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 /* Don't revalidate a negative dentry if we're creating a new file */
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400714 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 return 0;
716 return !nfs_check_verifier(dir, dentry);
717}
718
719/*
720 * This is called every time the dcache has a lookup hit,
721 * and we should check whether we can really trust that
722 * lookup.
723 *
724 * NOTE! The hit can be a negative hit too, don't assume
725 * we have an inode!
726 *
727 * If the parent directory is seen to have changed, we throw out the
728 * cached dentry and do a new lookup.
729 */
730static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
731{
732 struct inode *dir;
733 struct inode *inode;
734 struct dentry *parent;
735 int error;
736 struct nfs_fh fhandle;
737 struct nfs_fattr fattr;
738 unsigned long verifier;
739
740 parent = dget_parent(dentry);
741 lock_kernel();
742 dir = parent->d_inode;
Chuck Lever91d5b472006-03-20 13:44:14 -0500743 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 inode = dentry->d_inode;
745
746 if (!inode) {
747 if (nfs_neg_need_reval(dir, dentry, nd))
748 goto out_bad;
749 goto out_valid;
750 }
751
752 if (is_bad_inode(inode)) {
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500753 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
754 __FUNCTION__, dentry->d_parent->d_name.name,
755 dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 goto out_bad;
757 }
758
759 /* Revalidate parent directory attribute cache */
760 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
761 goto out_zap_parent;
762
763 /* Force a full look up iff the parent directory has changed */
764 if (nfs_check_verifier(dir, dentry)) {
765 if (nfs_lookup_verify_inode(inode, nd))
766 goto out_zap_parent;
767 goto out_valid;
768 }
769
770 if (NFS_STALE(inode))
771 goto out_bad;
772
773 verifier = nfs_save_change_attribute(dir);
774 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
775 if (error)
776 goto out_bad;
777 if (nfs_compare_fh(NFS_FH(inode), &fhandle))
778 goto out_bad;
779 if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
780 goto out_bad;
781
782 nfs_renew_times(dentry);
783 nfs_set_verifier(dentry, verifier);
784 out_valid:
785 unlock_kernel();
786 dput(parent);
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500787 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
788 __FUNCTION__, dentry->d_parent->d_name.name,
789 dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 return 1;
791out_zap_parent:
792 nfs_zap_caches(dir);
793 out_bad:
794 NFS_CACHEINV(dir);
795 if (inode && S_ISDIR(inode->i_mode)) {
796 /* Purge readdir caches. */
797 nfs_zap_caches(inode);
798 /* If we have submounts, don't unhash ! */
799 if (have_submounts(dentry))
800 goto out_valid;
801 shrink_dcache_parent(dentry);
802 }
803 d_drop(dentry);
804 unlock_kernel();
805 dput(parent);
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500806 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
807 __FUNCTION__, dentry->d_parent->d_name.name,
808 dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 return 0;
810}
811
812/*
813 * This is called from dput() when d_count is going to 0.
814 */
815static int nfs_dentry_delete(struct dentry *dentry)
816{
817 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
818 dentry->d_parent->d_name.name, dentry->d_name.name,
819 dentry->d_flags);
820
821 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
822 /* Unhash it, so that ->d_iput() would be called */
823 return 1;
824 }
825 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
826 /* Unhash it, so that ancestors of killed async unlink
827 * files will be cleaned up during umount */
828 return 1;
829 }
830 return 0;
831
832}
833
834/*
835 * Called when the dentry loses inode.
836 * We use it to clean up silly-renamed files.
837 */
838static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
839{
Trond Myklebustcae7a072005-10-18 14:20:19 -0700840 nfs_inode_return_delegation(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
842 lock_kernel();
843 inode->i_nlink--;
844 nfs_complete_unlink(dentry);
845 unlock_kernel();
846 }
847 /* When creating a negative dentry, we want to renew d_time */
848 nfs_renew_times(dentry);
849 iput(inode);
850}
851
852struct dentry_operations nfs_dentry_operations = {
853 .d_revalidate = nfs_lookup_revalidate,
854 .d_delete = nfs_dentry_delete,
855 .d_iput = nfs_dentry_iput,
856};
857
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400858/*
859 * Use intent information to check whether or not we're going to do
860 * an O_EXCL create using this path component.
861 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862static inline
863int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
864{
865 if (NFS_PROTO(dir)->version == 2)
866 return 0;
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400867 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 return 0;
869 return (nd->intent.open.flags & O_EXCL) != 0;
870}
871
872static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
873{
874 struct dentry *res;
875 struct inode *inode = NULL;
876 int error;
877 struct nfs_fh fhandle;
878 struct nfs_fattr fattr;
879
880 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
881 dentry->d_parent->d_name.name, dentry->d_name.name);
Chuck Lever91d5b472006-03-20 13:44:14 -0500882 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883
884 res = ERR_PTR(-ENAMETOOLONG);
885 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
886 goto out;
887
888 res = ERR_PTR(-ENOMEM);
889 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
890
891 lock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
893 /* If we're doing an exclusive create, optimize away the lookup */
894 if (nfs_is_exclusive_create(dir, nd))
895 goto no_entry;
896
897 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
898 if (error == -ENOENT)
899 goto no_entry;
900 if (error < 0) {
901 res = ERR_PTR(error);
902 goto out_unlock;
903 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
Trond Myklebust03f28e32006-03-20 13:44:48 -0500905 res = (struct dentry *)inode;
906 if (IS_ERR(res))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 goto out_unlock;
908no_entry:
909 res = d_add_unique(dentry, inode);
910 if (res != NULL)
911 dentry = res;
912 nfs_renew_times(dentry);
913 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
914out_unlock:
915 unlock_kernel();
916out:
917 return res;
918}
919
920#ifdef CONFIG_NFS_V4
921static int nfs_open_revalidate(struct dentry *, struct nameidata *);
922
923struct dentry_operations nfs4_dentry_operations = {
924 .d_revalidate = nfs_open_revalidate,
925 .d_delete = nfs_dentry_delete,
926 .d_iput = nfs_dentry_iput,
927};
928
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400929/*
930 * Use intent information to determine whether we need to substitute
931 * the NFSv4-style stateful OPEN for the LOOKUP call
932 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933static int is_atomic_open(struct inode *dir, struct nameidata *nd)
934{
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400935 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 return 0;
937 /* NFS does not (yet) have a stateful open for directories */
938 if (nd->flags & LOOKUP_DIRECTORY)
939 return 0;
940 /* Are we trying to write to a read only partition? */
941 if (IS_RDONLY(dir) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE)))
942 return 0;
943 return 1;
944}
945
946static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
947{
948 struct dentry *res = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949 int error;
950
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500951 dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
952 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
953
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954 /* Check that we are indeed trying to open this file */
955 if (!is_atomic_open(dir, nd))
956 goto no_open;
957
958 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
959 res = ERR_PTR(-ENAMETOOLONG);
960 goto out;
961 }
962 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
963
964 /* Let vfs_create() deal with O_EXCL */
Trond Myklebust02a913a2005-10-18 14:20:17 -0700965 if (nd->intent.open.flags & O_EXCL) {
966 d_add(dentry, NULL);
967 goto out;
968 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969
970 /* Open the file on the server */
971 lock_kernel();
972 /* Revalidate parent directory attribute cache */
973 error = nfs_revalidate_inode(NFS_SERVER(dir), dir);
974 if (error < 0) {
975 res = ERR_PTR(error);
Steve Dickson01c314a2005-08-19 17:57:48 -0700976 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 goto out;
978 }
979
980 if (nd->intent.open.flags & O_CREAT) {
981 nfs_begin_data_update(dir);
Trond Myklebust02a913a2005-10-18 14:20:17 -0700982 res = nfs4_atomic_open(dir, dentry, nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983 nfs_end_data_update(dir);
984 } else
Trond Myklebust02a913a2005-10-18 14:20:17 -0700985 res = nfs4_atomic_open(dir, dentry, nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986 unlock_kernel();
Trond Myklebust02a913a2005-10-18 14:20:17 -0700987 if (IS_ERR(res)) {
988 error = PTR_ERR(res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 switch (error) {
990 /* Make a negative dentry */
991 case -ENOENT:
Trond Myklebust02a913a2005-10-18 14:20:17 -0700992 res = NULL;
993 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 /* This turned out not to be a regular file */
Trond Myklebust6f926b52005-10-18 14:20:18 -0700995 case -EISDIR:
996 case -ENOTDIR:
997 goto no_open;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 case -ELOOP:
999 if (!(nd->intent.open.flags & O_NOFOLLOW))
1000 goto no_open;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 /* case -EINVAL: */
1002 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003 goto out;
1004 }
Trond Myklebust02a913a2005-10-18 14:20:17 -07001005 } else if (res != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 dentry = res;
1007 nfs_renew_times(dentry);
1008 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1009out:
1010 return res;
1011no_open:
1012 return nfs_lookup(dir, dentry, nd);
1013}
1014
1015static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
1016{
1017 struct dentry *parent = NULL;
1018 struct inode *inode = dentry->d_inode;
1019 struct inode *dir;
1020 unsigned long verifier;
1021 int openflags, ret = 0;
1022
1023 parent = dget_parent(dentry);
1024 dir = parent->d_inode;
1025 if (!is_atomic_open(dir, nd))
1026 goto no_open;
1027 /* We can't create new files in nfs_open_revalidate(), so we
1028 * optimize away revalidation of negative dentries.
1029 */
1030 if (inode == NULL)
1031 goto out;
1032 /* NFS only supports OPEN on regular files */
1033 if (!S_ISREG(inode->i_mode))
1034 goto no_open;
1035 openflags = nd->intent.open.flags;
1036 /* We cannot do exclusive creation on a positive dentry */
1037 if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
1038 goto no_open;
1039 /* We can't create new files, or truncate existing ones here */
1040 openflags &= ~(O_CREAT|O_TRUNC);
1041
1042 /*
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001043 * Note: we're not holding inode->i_mutex and so may be racing with
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 * operations that change the directory. We therefore save the
1045 * change attribute *before* we do the RPC call.
1046 */
1047 lock_kernel();
1048 verifier = nfs_save_change_attribute(dir);
Trond Myklebust02a913a2005-10-18 14:20:17 -07001049 ret = nfs4_open_revalidate(dir, dentry, openflags, nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 if (!ret)
1051 nfs_set_verifier(dentry, verifier);
1052 unlock_kernel();
1053out:
1054 dput(parent);
1055 if (!ret)
1056 d_drop(dentry);
1057 return ret;
1058no_open:
1059 dput(parent);
1060 if (inode != NULL && nfs_have_delegation(inode, FMODE_READ))
1061 return 1;
1062 return nfs_lookup_revalidate(dentry, nd);
1063}
1064#endif /* CONFIG_NFSV4 */
1065
1066static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc)
1067{
1068 struct dentry *parent = desc->file->f_dentry;
1069 struct inode *dir = parent->d_inode;
1070 struct nfs_entry *entry = desc->entry;
1071 struct dentry *dentry, *alias;
1072 struct qstr name = {
1073 .name = entry->name,
1074 .len = entry->len,
1075 };
1076 struct inode *inode;
1077
1078 switch (name.len) {
1079 case 2:
1080 if (name.name[0] == '.' && name.name[1] == '.')
1081 return dget_parent(parent);
1082 break;
1083 case 1:
1084 if (name.name[0] == '.')
1085 return dget(parent);
1086 }
1087 name.hash = full_name_hash(name.name, name.len);
1088 dentry = d_lookup(parent, &name);
1089 if (dentry != NULL)
1090 return dentry;
1091 if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR))
1092 return NULL;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001093 /* Note: caller is already holding the dir->i_mutex! */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001094 dentry = d_alloc(parent, &name);
1095 if (dentry == NULL)
1096 return NULL;
1097 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
1098 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
Trond Myklebust03f28e32006-03-20 13:44:48 -05001099 if (IS_ERR(inode)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001100 dput(dentry);
1101 return NULL;
1102 }
1103 alias = d_add_unique(dentry, inode);
1104 if (alias != NULL) {
1105 dput(dentry);
1106 dentry = alias;
1107 }
1108 nfs_renew_times(dentry);
1109 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1110 return dentry;
1111}
1112
1113/*
1114 * Code common to create, mkdir, and mknod.
1115 */
1116int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1117 struct nfs_fattr *fattr)
1118{
1119 struct inode *inode;
1120 int error = -EACCES;
1121
1122 /* We may have been initialized further down */
1123 if (dentry->d_inode)
1124 return 0;
1125 if (fhandle->size == 0) {
1126 struct inode *dir = dentry->d_parent->d_inode;
1127 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
1128 if (error)
1129 goto out_err;
1130 }
1131 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1132 struct nfs_server *server = NFS_SB(dentry->d_sb);
1133 error = server->rpc_ops->getattr(server, fhandle, fattr);
1134 if (error < 0)
1135 goto out_err;
1136 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001137 inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
Trond Myklebust03f28e32006-03-20 13:44:48 -05001138 error = PTR_ERR(inode);
1139 if (IS_ERR(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001140 goto out_err;
1141 d_instantiate(dentry, inode);
1142 return 0;
1143out_err:
1144 d_drop(dentry);
1145 return error;
1146}
1147
1148/*
1149 * Following a failed create operation, we drop the dentry rather
1150 * than retain a negative dentry. This avoids a problem in the event
1151 * that the operation succeeded on the server, but an error in the
1152 * reply path made it appear to have failed.
1153 */
1154static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
1155 struct nameidata *nd)
1156{
1157 struct iattr attr;
1158 int error;
1159 int open_flags = 0;
1160
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001161 dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
1162 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163
1164 attr.ia_mode = mode;
1165 attr.ia_valid = ATTR_MODE;
1166
1167 if (nd && (nd->flags & LOOKUP_CREATE))
1168 open_flags = nd->intent.open.flags;
1169
1170 lock_kernel();
1171 nfs_begin_data_update(dir);
Trond Myklebust02a913a2005-10-18 14:20:17 -07001172 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 nfs_end_data_update(dir);
1174 if (error != 0)
1175 goto out_err;
1176 nfs_renew_times(dentry);
1177 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1178 unlock_kernel();
1179 return 0;
1180out_err:
1181 unlock_kernel();
1182 d_drop(dentry);
1183 return error;
1184}
1185
1186/*
1187 * See comments for nfs_proc_create regarding failed operations.
1188 */
1189static int
1190nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1191{
1192 struct iattr attr;
1193 int status;
1194
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001195 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
1196 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197
1198 if (!new_valid_dev(rdev))
1199 return -EINVAL;
1200
1201 attr.ia_mode = mode;
1202 attr.ia_valid = ATTR_MODE;
1203
1204 lock_kernel();
1205 nfs_begin_data_update(dir);
1206 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
1207 nfs_end_data_update(dir);
1208 if (status != 0)
1209 goto out_err;
1210 nfs_renew_times(dentry);
1211 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1212 unlock_kernel();
1213 return 0;
1214out_err:
1215 unlock_kernel();
1216 d_drop(dentry);
1217 return status;
1218}
1219
1220/*
1221 * See comments for nfs_proc_create regarding failed operations.
1222 */
1223static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1224{
1225 struct iattr attr;
1226 int error;
1227
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001228 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
1229 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230
1231 attr.ia_valid = ATTR_MODE;
1232 attr.ia_mode = mode | S_IFDIR;
1233
1234 lock_kernel();
1235 nfs_begin_data_update(dir);
1236 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
1237 nfs_end_data_update(dir);
1238 if (error != 0)
1239 goto out_err;
1240 nfs_renew_times(dentry);
1241 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1242 unlock_kernel();
1243 return 0;
1244out_err:
1245 d_drop(dentry);
1246 unlock_kernel();
1247 return error;
1248}
1249
1250static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1251{
1252 int error;
1253
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001254 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
1255 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256
1257 lock_kernel();
1258 nfs_begin_data_update(dir);
1259 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
1260 /* Ensure the VFS deletes this inode */
1261 if (error == 0 && dentry->d_inode != NULL)
1262 dentry->d_inode->i_nlink = 0;
1263 nfs_end_data_update(dir);
1264 unlock_kernel();
1265
1266 return error;
1267}
1268
1269static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
1270{
1271 static unsigned int sillycounter;
1272 const int i_inosize = sizeof(dir->i_ino)*2;
1273 const int countersize = sizeof(sillycounter)*2;
1274 const int slen = sizeof(".nfs") + i_inosize + countersize - 1;
1275 char silly[slen+1];
1276 struct qstr qsilly;
1277 struct dentry *sdentry;
1278 int error = -EIO;
1279
1280 dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
1281 dentry->d_parent->d_name.name, dentry->d_name.name,
1282 atomic_read(&dentry->d_count));
Chuck Lever91d5b472006-03-20 13:44:14 -05001283 nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001284
1285#ifdef NFS_PARANOIA
1286if (!dentry->d_inode)
1287printk("NFS: silly-renaming %s/%s, negative dentry??\n",
1288dentry->d_parent->d_name.name, dentry->d_name.name);
1289#endif
1290 /*
1291 * We don't allow a dentry to be silly-renamed twice.
1292 */
1293 error = -EBUSY;
1294 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1295 goto out;
1296
1297 sprintf(silly, ".nfs%*.*lx",
1298 i_inosize, i_inosize, dentry->d_inode->i_ino);
1299
Trond Myklebust34ea81882005-11-04 15:35:02 -05001300 /* Return delegation in anticipation of the rename */
1301 nfs_inode_return_delegation(dentry->d_inode);
1302
Linus Torvalds1da177e2005-04-16 15:20:36 -07001303 sdentry = NULL;
1304 do {
1305 char *suffix = silly + slen - countersize;
1306
1307 dput(sdentry);
1308 sillycounter++;
1309 sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
1310
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001311 dfprintk(VFS, "NFS: trying to rename %s to %s\n",
1312 dentry->d_name.name, silly);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313
1314 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
1315 /*
1316 * N.B. Better to return EBUSY here ... it could be
1317 * dangerous to delete the file while it's in use.
1318 */
1319 if (IS_ERR(sdentry))
1320 goto out;
1321 } while(sdentry->d_inode != NULL); /* need negative lookup */
1322
1323 qsilly.name = silly;
1324 qsilly.len = strlen(silly);
1325 nfs_begin_data_update(dir);
1326 if (dentry->d_inode) {
1327 nfs_begin_data_update(dentry->d_inode);
1328 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1329 dir, &qsilly);
Trond Myklebust5ba7cc42005-12-03 15:20:17 -05001330 nfs_mark_for_revalidate(dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001331 nfs_end_data_update(dentry->d_inode);
1332 } else
1333 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1334 dir, &qsilly);
1335 nfs_end_data_update(dir);
1336 if (!error) {
1337 nfs_renew_times(dentry);
1338 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1339 d_move(dentry, sdentry);
1340 error = nfs_async_unlink(dentry);
1341 /* If we return 0 we don't unlink */
1342 }
1343 dput(sdentry);
1344out:
1345 return error;
1346}
1347
1348/*
1349 * Remove a file after making sure there are no pending writes,
1350 * and after checking that the file has only one user.
1351 *
1352 * We invalidate the attribute cache and free the inode prior to the operation
1353 * to avoid possible races if the server reuses the inode.
1354 */
1355static int nfs_safe_remove(struct dentry *dentry)
1356{
1357 struct inode *dir = dentry->d_parent->d_inode;
1358 struct inode *inode = dentry->d_inode;
1359 int error = -EBUSY;
1360
1361 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1362 dentry->d_parent->d_name.name, dentry->d_name.name);
1363
1364 /* If the dentry was sillyrenamed, we simply call d_delete() */
1365 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1366 error = 0;
1367 goto out;
1368 }
1369
1370 nfs_begin_data_update(dir);
1371 if (inode != NULL) {
Trond Myklebustcae7a072005-10-18 14:20:19 -07001372 nfs_inode_return_delegation(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 nfs_begin_data_update(inode);
1374 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1375 /* The VFS may want to delete this inode */
1376 if (error == 0)
1377 inode->i_nlink--;
Trond Myklebust5ba7cc42005-12-03 15:20:17 -05001378 nfs_mark_for_revalidate(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379 nfs_end_data_update(inode);
1380 } else
1381 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1382 nfs_end_data_update(dir);
1383out:
1384 return error;
1385}
1386
1387/* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1388 * belongs to an active ".nfs..." file and we return -EBUSY.
1389 *
1390 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1391 */
1392static int nfs_unlink(struct inode *dir, struct dentry *dentry)
1393{
1394 int error;
1395 int need_rehash = 0;
1396
1397 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1398 dir->i_ino, dentry->d_name.name);
1399
1400 lock_kernel();
1401 spin_lock(&dcache_lock);
1402 spin_lock(&dentry->d_lock);
1403 if (atomic_read(&dentry->d_count) > 1) {
1404 spin_unlock(&dentry->d_lock);
1405 spin_unlock(&dcache_lock);
1406 error = nfs_sillyrename(dir, dentry);
1407 unlock_kernel();
1408 return error;
1409 }
1410 if (!d_unhashed(dentry)) {
1411 __d_drop(dentry);
1412 need_rehash = 1;
1413 }
1414 spin_unlock(&dentry->d_lock);
1415 spin_unlock(&dcache_lock);
1416 error = nfs_safe_remove(dentry);
1417 if (!error) {
1418 nfs_renew_times(dentry);
1419 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1420 } else if (need_rehash)
1421 d_rehash(dentry);
1422 unlock_kernel();
1423 return error;
1424}
1425
1426static int
1427nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1428{
1429 struct iattr attr;
1430 struct nfs_fattr sym_attr;
1431 struct nfs_fh sym_fh;
1432 struct qstr qsymname;
1433 int error;
1434
1435 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1436 dir->i_ino, dentry->d_name.name, symname);
1437
1438#ifdef NFS_PARANOIA
1439if (dentry->d_inode)
1440printk("nfs_proc_symlink: %s/%s not negative!\n",
1441dentry->d_parent->d_name.name, dentry->d_name.name);
1442#endif
1443 /*
1444 * Fill in the sattr for the call.
1445 * Note: SunOS 4.1.2 crashes if the mode isn't initialized!
1446 */
1447 attr.ia_valid = ATTR_MODE;
1448 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1449
1450 qsymname.name = symname;
1451 qsymname.len = strlen(symname);
1452
1453 lock_kernel();
1454 nfs_begin_data_update(dir);
1455 error = NFS_PROTO(dir)->symlink(dir, &dentry->d_name, &qsymname,
1456 &attr, &sym_fh, &sym_attr);
1457 nfs_end_data_update(dir);
1458 if (!error) {
1459 error = nfs_instantiate(dentry, &sym_fh, &sym_attr);
1460 } else {
1461 if (error == -EEXIST)
1462 printk("nfs_proc_symlink: %s/%s already exists??\n",
1463 dentry->d_parent->d_name.name, dentry->d_name.name);
1464 d_drop(dentry);
1465 }
1466 unlock_kernel();
1467 return error;
1468}
1469
1470static int
1471nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1472{
1473 struct inode *inode = old_dentry->d_inode;
1474 int error;
1475
1476 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
1477 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1478 dentry->d_parent->d_name.name, dentry->d_name.name);
1479
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480 lock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001481 nfs_begin_data_update(dir);
1482 nfs_begin_data_update(inode);
1483 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
Trond Myklebustcf809552005-10-27 22:12:42 -04001484 if (error == 0) {
1485 atomic_inc(&inode->i_count);
1486 d_instantiate(dentry, inode);
1487 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001488 nfs_end_data_update(inode);
1489 nfs_end_data_update(dir);
1490 unlock_kernel();
1491 return error;
1492}
1493
1494/*
1495 * RENAME
1496 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
1497 * different file handle for the same inode after a rename (e.g. when
1498 * moving to a different directory). A fail-safe method to do so would
1499 * be to look up old_dir/old_name, create a link to new_dir/new_name and
1500 * rename the old file using the sillyrename stuff. This way, the original
1501 * file in old_dir will go away when the last process iput()s the inode.
1502 *
1503 * FIXED.
1504 *
1505 * It actually works quite well. One needs to have the possibility for
1506 * at least one ".nfs..." file in each directory the file ever gets
1507 * moved or linked to which happens automagically with the new
1508 * implementation that only depends on the dcache stuff instead of
1509 * using the inode layer
1510 *
1511 * Unfortunately, things are a little more complicated than indicated
1512 * above. For a cross-directory move, we want to make sure we can get
1513 * rid of the old inode after the operation. This means there must be
1514 * no pending writes (if it's a file), and the use count must be 1.
1515 * If these conditions are met, we can drop the dentries before doing
1516 * the rename.
1517 */
1518static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1519 struct inode *new_dir, struct dentry *new_dentry)
1520{
1521 struct inode *old_inode = old_dentry->d_inode;
1522 struct inode *new_inode = new_dentry->d_inode;
1523 struct dentry *dentry = NULL, *rehash = NULL;
1524 int error = -EBUSY;
1525
1526 /*
1527 * To prevent any new references to the target during the rename,
1528 * we unhash the dentry and free the inode in advance.
1529 */
1530 lock_kernel();
1531 if (!d_unhashed(new_dentry)) {
1532 d_drop(new_dentry);
1533 rehash = new_dentry;
1534 }
1535
1536 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
1537 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1538 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
1539 atomic_read(&new_dentry->d_count));
1540
1541 /*
1542 * First check whether the target is busy ... we can't
1543 * safely do _any_ rename if the target is in use.
1544 *
1545 * For files, make a copy of the dentry and then do a
1546 * silly-rename. If the silly-rename succeeds, the
1547 * copied dentry is hashed and becomes the new target.
1548 */
1549 if (!new_inode)
1550 goto go_ahead;
Trond Myklebust6fe43f92005-10-18 14:20:22 -07001551 if (S_ISDIR(new_inode->i_mode)) {
1552 error = -EISDIR;
1553 if (!S_ISDIR(old_inode->i_mode))
1554 goto out;
1555 } else if (atomic_read(&new_dentry->d_count) > 2) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001556 int err;
1557 /* copy the target dentry's name */
1558 dentry = d_alloc(new_dentry->d_parent,
1559 &new_dentry->d_name);
1560 if (!dentry)
1561 goto out;
1562
1563 /* silly-rename the existing target ... */
1564 err = nfs_sillyrename(new_dir, new_dentry);
1565 if (!err) {
1566 new_dentry = rehash = dentry;
1567 new_inode = NULL;
1568 /* instantiate the replacement target */
1569 d_instantiate(new_dentry, NULL);
1570 } else if (atomic_read(&new_dentry->d_count) > 1) {
1571 /* dentry still busy? */
1572#ifdef NFS_PARANOIA
1573 printk("nfs_rename: target %s/%s busy, d_count=%d\n",
1574 new_dentry->d_parent->d_name.name,
1575 new_dentry->d_name.name,
1576 atomic_read(&new_dentry->d_count));
1577#endif
1578 goto out;
1579 }
Trond Myklebust20509f12005-08-25 16:25:34 -07001580 } else
1581 new_inode->i_nlink--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001582
1583go_ahead:
1584 /*
1585 * ... prune child dentries and writebacks if needed.
1586 */
1587 if (atomic_read(&old_dentry->d_count) > 1) {
1588 nfs_wb_all(old_inode);
1589 shrink_dcache_parent(old_dentry);
1590 }
Trond Myklebustcae7a072005-10-18 14:20:19 -07001591 nfs_inode_return_delegation(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001592
Trond Myklebust24174112006-01-03 09:55:33 +01001593 if (new_inode != NULL) {
1594 nfs_inode_return_delegation(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001595 d_delete(new_dentry);
Trond Myklebust24174112006-01-03 09:55:33 +01001596 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001597
1598 nfs_begin_data_update(old_dir);
1599 nfs_begin_data_update(new_dir);
1600 nfs_begin_data_update(old_inode);
1601 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
1602 new_dir, &new_dentry->d_name);
Trond Myklebust5ba7cc42005-12-03 15:20:17 -05001603 nfs_mark_for_revalidate(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001604 nfs_end_data_update(old_inode);
1605 nfs_end_data_update(new_dir);
1606 nfs_end_data_update(old_dir);
1607out:
1608 if (rehash)
1609 d_rehash(rehash);
1610 if (!error) {
1611 if (!S_ISDIR(old_inode->i_mode))
1612 d_move(old_dentry, new_dentry);
1613 nfs_renew_times(new_dentry);
1614 nfs_set_verifier(new_dentry, nfs_save_change_attribute(new_dir));
1615 }
1616
1617 /* new dentry created? */
1618 if (dentry)
1619 dput(dentry);
1620 unlock_kernel();
1621 return error;
1622}
1623
1624int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
1625{
Chuck Lever55296802005-08-18 11:24:09 -07001626 struct nfs_inode *nfsi = NFS_I(inode);
1627 struct nfs_access_entry *cache = &nfsi->cache_access;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628
1629 if (cache->cred != cred
1630 || time_after(jiffies, cache->jiffies + NFS_ATTRTIMEO(inode))
Chuck Lever55296802005-08-18 11:24:09 -07001631 || (nfsi->cache_validity & NFS_INO_INVALID_ACCESS))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001632 return -ENOENT;
1633 memcpy(res, cache, sizeof(*res));
1634 return 0;
1635}
1636
1637void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
1638{
Chuck Lever55296802005-08-18 11:24:09 -07001639 struct nfs_inode *nfsi = NFS_I(inode);
1640 struct nfs_access_entry *cache = &nfsi->cache_access;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001641
1642 if (cache->cred != set->cred) {
1643 if (cache->cred)
1644 put_rpccred(cache->cred);
1645 cache->cred = get_rpccred(set->cred);
1646 }
Chuck Leverdc592502005-08-18 11:24:12 -07001647 /* FIXME: replace current access_cache BKL reliance with inode->i_lock */
1648 spin_lock(&inode->i_lock);
Chuck Lever55296802005-08-18 11:24:09 -07001649 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
Chuck Leverdc592502005-08-18 11:24:12 -07001650 spin_unlock(&inode->i_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651 cache->jiffies = set->jiffies;
1652 cache->mask = set->mask;
1653}
1654
1655static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
1656{
1657 struct nfs_access_entry cache;
1658 int status;
1659
1660 status = nfs_access_get_cached(inode, cred, &cache);
1661 if (status == 0)
1662 goto out;
1663
1664 /* Be clever: ask server to check for all possible rights */
1665 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
1666 cache.cred = cred;
1667 cache.jiffies = jiffies;
1668 status = NFS_PROTO(inode)->access(inode, &cache);
1669 if (status != 0)
1670 return status;
1671 nfs_access_add_cache(inode, &cache);
1672out:
1673 if ((cache.mask & mask) == mask)
1674 return 0;
1675 return -EACCES;
1676}
1677
1678int nfs_permission(struct inode *inode, int mask, struct nameidata *nd)
1679{
1680 struct rpc_cred *cred;
1681 int res = 0;
1682
Chuck Lever91d5b472006-03-20 13:44:14 -05001683 nfs_inc_stats(inode, NFSIOS_VFSACCESS);
1684
Linus Torvalds1da177e2005-04-16 15:20:36 -07001685 if (mask == 0)
1686 goto out;
1687 /* Is this sys_access() ? */
1688 if (nd != NULL && (nd->flags & LOOKUP_ACCESS))
1689 goto force_lookup;
1690
1691 switch (inode->i_mode & S_IFMT) {
1692 case S_IFLNK:
1693 goto out;
1694 case S_IFREG:
1695 /* NFSv4 has atomic_open... */
1696 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
1697 && nd != NULL
1698 && (nd->flags & LOOKUP_OPEN))
1699 goto out;
1700 break;
1701 case S_IFDIR:
1702 /*
1703 * Optimize away all write operations, since the server
1704 * will check permissions when we perform the op.
1705 */
1706 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
1707 goto out;
1708 }
1709
1710force_lookup:
1711 lock_kernel();
1712
1713 if (!NFS_PROTO(inode)->access)
1714 goto out_notsup;
1715
1716 cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
1717 if (!IS_ERR(cred)) {
1718 res = nfs_do_access(inode, cred, mask);
1719 put_rpccred(cred);
1720 } else
1721 res = PTR_ERR(cred);
1722 unlock_kernel();
1723out:
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001724 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
1725 inode->i_sb->s_id, inode->i_ino, mask, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001726 return res;
1727out_notsup:
1728 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
1729 if (res == 0)
1730 res = generic_permission(inode, mask, NULL);
1731 unlock_kernel();
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001732 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001733}
1734
1735/*
1736 * Local variables:
1737 * version-control: t
1738 * kept-new-versions: 5
1739 * End:
1740 */