blob: cae74dd4c7f51f6bd674c5e61bad36c415cb4460 [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{
Carsten Otte7451c4f2006-04-19 13:06:37 -0400131 int res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
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 */
Carsten Otte7451c4f2006-04-19 13:06:37 -0400138 res = nfs_open(inode, filp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 unlock_kernel();
140 return res;
141}
142
143typedef u32 * (*decode_dirent_t)(u32 *, struct nfs_entry *, int);
144typedef struct {
145 struct file *file;
146 struct page *page;
147 unsigned long page_index;
148 u32 *ptr;
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000149 u64 *dir_cookie;
150 loff_t current_index;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 struct nfs_entry *entry;
152 decode_dirent_t decode;
153 int plus;
154 int error;
155} nfs_readdir_descriptor_t;
156
157/* Now we cache directories properly, by stuffing the dirent
158 * data directly in the page cache.
159 *
160 * Inode invalidation due to refresh etc. takes care of
161 * _everything_, no sloppy entry flushing logic, no extraneous
162 * copying, network direct to page cache, the way it was meant
163 * to be.
164 *
165 * NOTE: Dirent information verification is done always by the
166 * page-in of the RPC reply, nowhere else, this simplies
167 * things substantially.
168 */
169static
170int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page)
171{
172 struct file *file = desc->file;
173 struct inode *inode = file->f_dentry->d_inode;
174 struct rpc_cred *cred = nfs_file_cred(file);
175 unsigned long timestamp;
176 int error;
177
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500178 dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n",
179 __FUNCTION__, (long long)desc->entry->cookie,
180 page->index);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182 again:
183 timestamp = jiffies;
184 error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->entry->cookie, page,
185 NFS_SERVER(inode)->dtsize, desc->plus);
186 if (error < 0) {
187 /* We requested READDIRPLUS, but the server doesn't grok it */
188 if (error == -ENOTSUPP && desc->plus) {
189 NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS;
Chuck Lever412d5822005-08-18 11:24:11 -0700190 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 desc->plus = 0;
192 goto again;
193 }
194 goto error;
195 }
196 SetPageUptodate(page);
Chuck Leverdc592502005-08-18 11:24:12 -0700197 spin_lock(&inode->i_lock);
Chuck Lever55296802005-08-18 11:24:09 -0700198 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
Chuck Leverdc592502005-08-18 11:24:12 -0700199 spin_unlock(&inode->i_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 /* Ensure consistent page alignment of the data.
201 * Note: assumes we have exclusive access to this mapping either
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800202 * through inode->i_mutex or some other mechanism.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 */
Trond Myklebusta656db92005-06-22 17:16:21 +0000204 if (page->index == 0)
205 invalidate_inode_pages2_range(inode->i_mapping, PAGE_CACHE_SIZE, -1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 unlock_page(page);
207 return 0;
208 error:
209 SetPageError(page);
210 unlock_page(page);
211 nfs_zap_caches(inode);
212 desc->error = error;
213 return -EIO;
214}
215
216static inline
217int dir_decode(nfs_readdir_descriptor_t *desc)
218{
219 u32 *p = desc->ptr;
220 p = desc->decode(p, desc->entry, desc->plus);
221 if (IS_ERR(p))
222 return PTR_ERR(p);
223 desc->ptr = p;
224 return 0;
225}
226
227static inline
228void dir_page_release(nfs_readdir_descriptor_t *desc)
229{
230 kunmap(desc->page);
231 page_cache_release(desc->page);
232 desc->page = NULL;
233 desc->ptr = NULL;
234}
235
236/*
237 * Given a pointer to a buffer that has already been filled by a call
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000238 * to readdir, find the next entry with cookie '*desc->dir_cookie'.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 *
240 * If the end of the buffer has been reached, return -EAGAIN, if not,
241 * return the offset within the buffer of the next entry to be
242 * read.
243 */
244static inline
Olivier Galibert00a92642005-06-22 17:16:29 +0000245int find_dirent(nfs_readdir_descriptor_t *desc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246{
247 struct nfs_entry *entry = desc->entry;
248 int loop_count = 0,
249 status;
250
251 while((status = dir_decode(desc)) == 0) {
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500252 dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n",
253 __FUNCTION__, (unsigned long long)entry->cookie);
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000254 if (entry->prev_cookie == *desc->dir_cookie)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 break;
256 if (loop_count++ > 200) {
257 loop_count = 0;
258 schedule();
259 }
260 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 return status;
262}
263
264/*
Olivier Galibert00a92642005-06-22 17:16:29 +0000265 * Given a pointer to a buffer that has already been filled by a call
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000266 * to readdir, find the entry at offset 'desc->file->f_pos'.
Olivier Galibert00a92642005-06-22 17:16:29 +0000267 *
268 * If the end of the buffer has been reached, return -EAGAIN, if not,
269 * return the offset within the buffer of the next entry to be
270 * read.
271 */
272static inline
273int find_dirent_index(nfs_readdir_descriptor_t *desc)
274{
275 struct nfs_entry *entry = desc->entry;
276 int loop_count = 0,
277 status;
278
279 for(;;) {
280 status = dir_decode(desc);
281 if (status)
282 break;
283
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500284 dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n",
285 (unsigned long long)entry->cookie, desc->current_index);
Olivier Galibert00a92642005-06-22 17:16:29 +0000286
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000287 if (desc->file->f_pos == desc->current_index) {
288 *desc->dir_cookie = entry->cookie;
Olivier Galibert00a92642005-06-22 17:16:29 +0000289 break;
290 }
291 desc->current_index++;
292 if (loop_count++ > 200) {
293 loop_count = 0;
294 schedule();
295 }
296 }
Olivier Galibert00a92642005-06-22 17:16:29 +0000297 return status;
298}
299
300/*
301 * Find the given page, and call find_dirent() or find_dirent_index in
302 * order to try to return the next entry.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 */
304static inline
305int find_dirent_page(nfs_readdir_descriptor_t *desc)
306{
307 struct inode *inode = desc->file->f_dentry->d_inode;
308 struct page *page;
309 int status;
310
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500311 dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n",
312 __FUNCTION__, desc->page_index,
313 (long long) *desc->dir_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314
315 page = read_cache_page(inode->i_mapping, desc->page_index,
316 (filler_t *)nfs_readdir_filler, desc);
317 if (IS_ERR(page)) {
318 status = PTR_ERR(page);
319 goto out;
320 }
321 if (!PageUptodate(page))
322 goto read_error;
323
324 /* NOTE: Someone else may have changed the READDIRPLUS flag */
325 desc->page = page;
326 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000327 if (*desc->dir_cookie != 0)
Olivier Galibert00a92642005-06-22 17:16:29 +0000328 status = find_dirent(desc);
329 else
330 status = find_dirent_index(desc);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331 if (status < 0)
332 dir_page_release(desc);
333 out:
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500334 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 return status;
336 read_error:
337 page_cache_release(page);
338 return -EIO;
339}
340
341/*
342 * Recurse through the page cache pages, and return a
343 * filled nfs_entry structure of the next directory entry if possible.
344 *
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000345 * The target for the search is '*desc->dir_cookie' if non-0,
346 * 'desc->file->f_pos' otherwise
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 */
348static inline
349int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
350{
351 int loop_count = 0;
352 int res;
353
Olivier Galibert00a92642005-06-22 17:16:29 +0000354 /* Always search-by-index from the beginning of the cache */
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000355 if (*desc->dir_cookie == 0) {
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500356 dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n",
357 (long long)desc->file->f_pos);
Olivier Galibert00a92642005-06-22 17:16:29 +0000358 desc->page_index = 0;
359 desc->entry->cookie = desc->entry->prev_cookie = 0;
360 desc->entry->eof = 0;
361 desc->current_index = 0;
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000362 } else
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500363 dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n",
364 (unsigned long long)*desc->dir_cookie);
Olivier Galibert00a92642005-06-22 17:16:29 +0000365
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 for (;;) {
367 res = find_dirent_page(desc);
368 if (res != -EAGAIN)
369 break;
370 /* Align to beginning of next page */
371 desc->page_index ++;
372 if (loop_count++ > 200) {
373 loop_count = 0;
374 schedule();
375 }
376 }
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500377
378 dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __FUNCTION__, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 return res;
380}
381
382static inline unsigned int dt_type(struct inode *inode)
383{
384 return (inode->i_mode >> 12) & 15;
385}
386
387static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc);
388
389/*
390 * Once we've found the start of the dirent within a page: fill 'er up...
391 */
392static
393int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent,
394 filldir_t filldir)
395{
396 struct file *file = desc->file;
397 struct nfs_entry *entry = desc->entry;
398 struct dentry *dentry = NULL;
399 unsigned long fileid;
400 int loop_count = 0,
401 res;
402
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500403 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n",
404 (unsigned long long)entry->cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405
406 for(;;) {
407 unsigned d_type = DT_UNKNOWN;
408 /* Note: entry->prev_cookie contains the cookie for
409 * retrieving the current dirent on the server */
410 fileid = nfs_fileid_to_ino_t(entry->ino);
411
412 /* Get a dentry if we have one */
413 if (dentry != NULL)
414 dput(dentry);
415 dentry = nfs_readdir_lookup(desc);
416
417 /* Use readdirplus info */
418 if (dentry != NULL && dentry->d_inode != NULL) {
419 d_type = dt_type(dentry->d_inode);
420 fileid = dentry->d_inode->i_ino;
421 }
422
423 res = filldir(dirent, entry->name, entry->len,
Olivier Galibert00a92642005-06-22 17:16:29 +0000424 file->f_pos, fileid, d_type);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 if (res < 0)
426 break;
Olivier Galibert00a92642005-06-22 17:16:29 +0000427 file->f_pos++;
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000428 *desc->dir_cookie = entry->cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 if (dir_decode(desc) != 0) {
430 desc->page_index ++;
431 break;
432 }
433 if (loop_count++ > 200) {
434 loop_count = 0;
435 schedule();
436 }
437 }
438 dir_page_release(desc);
439 if (dentry != NULL)
440 dput(dentry);
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500441 dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
442 (unsigned long long)*desc->dir_cookie, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 return res;
444}
445
446/*
447 * If we cannot find a cookie in our cache, we suspect that this is
448 * because it points to a deleted file, so we ask the server to return
449 * whatever it thinks is the next entry. We then feed this to filldir.
450 * If all goes well, we should then be able to find our way round the
451 * cache on the next call to readdir_search_pagecache();
452 *
453 * NOTE: we cannot add the anonymous page to the pagecache because
454 * the data it contains might not be page aligned. Besides,
455 * we should already have a complete representation of the
456 * directory in the page cache by the time we get here.
457 */
458static inline
459int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent,
460 filldir_t filldir)
461{
462 struct file *file = desc->file;
463 struct inode *inode = file->f_dentry->d_inode;
464 struct rpc_cred *cred = nfs_file_cred(file);
465 struct page *page = NULL;
466 int status;
467
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500468 dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n",
469 (unsigned long long)*desc->dir_cookie);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470
471 page = alloc_page(GFP_HIGHUSER);
472 if (!page) {
473 status = -ENOMEM;
474 goto out;
475 }
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000476 desc->error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, *desc->dir_cookie,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 page,
478 NFS_SERVER(inode)->dtsize,
479 desc->plus);
Chuck Leverdc592502005-08-18 11:24:12 -0700480 spin_lock(&inode->i_lock);
Chuck Lever55296802005-08-18 11:24:09 -0700481 NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
Chuck Leverdc592502005-08-18 11:24:12 -0700482 spin_unlock(&inode->i_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 desc->page = page;
484 desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */
485 if (desc->error >= 0) {
486 if ((status = dir_decode(desc)) == 0)
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000487 desc->entry->prev_cookie = *desc->dir_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 } else
489 status = -EIO;
490 if (status < 0)
491 goto out_release;
492
493 status = nfs_do_filldir(desc, dirent, filldir);
494
495 /* Reset read descriptor so it searches the page cache from
496 * the start upon the next call to readdir_search_pagecache() */
497 desc->page_index = 0;
498 desc->entry->cookie = desc->entry->prev_cookie = 0;
499 desc->entry->eof = 0;
500 out:
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500501 dfprintk(DIRCACHE, "NFS: %s: returns %d\n",
502 __FUNCTION__, status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 return status;
504 out_release:
505 dir_page_release(desc);
506 goto out;
507}
508
Olivier Galibert00a92642005-06-22 17:16:29 +0000509/* The file offset position represents the dirent entry number. A
510 last cookie cache takes care of the common case of reading the
511 whole directory.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 */
513static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
514{
515 struct dentry *dentry = filp->f_dentry;
516 struct inode *inode = dentry->d_inode;
517 nfs_readdir_descriptor_t my_desc,
518 *desc = &my_desc;
519 struct nfs_entry my_entry;
520 struct nfs_fh fh;
521 struct nfs_fattr fattr;
522 long res;
523
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500524 dfprintk(VFS, "NFS: readdir(%s/%s) starting at cookie %Lu\n",
525 dentry->d_parent->d_name.name, dentry->d_name.name,
526 (long long)filp->f_pos);
Chuck Lever91d5b472006-03-20 13:44:14 -0500527 nfs_inc_stats(inode, NFSIOS_VFSGETDENTS);
528
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529 lock_kernel();
530
531 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
532 if (res < 0) {
533 unlock_kernel();
534 return res;
535 }
536
537 /*
Olivier Galibert00a92642005-06-22 17:16:29 +0000538 * filp->f_pos points to the dirent entry number.
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000539 * *desc->dir_cookie has the cookie for the next entry. We have
Olivier Galibert00a92642005-06-22 17:16:29 +0000540 * to either find the entry with the appropriate number or
541 * revalidate the cookie.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 */
543 memset(desc, 0, sizeof(*desc));
544
545 desc->file = filp;
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000546 desc->dir_cookie = &((struct nfs_open_context *)filp->private_data)->dir_cookie;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 desc->decode = NFS_PROTO(inode)->decode_dirent;
548 desc->plus = NFS_USE_READDIRPLUS(inode);
549
550 my_entry.cookie = my_entry.prev_cookie = 0;
551 my_entry.eof = 0;
552 my_entry.fh = &fh;
553 my_entry.fattr = &fattr;
Trond Myklebust0e574af2005-10-27 22:12:38 -0400554 nfs_fattr_init(&fattr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 desc->entry = &my_entry;
556
557 while(!desc->entry->eof) {
558 res = readdir_search_pagecache(desc);
Olivier Galibert00a92642005-06-22 17:16:29 +0000559
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 if (res == -EBADCOOKIE) {
561 /* This means either end of directory */
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000562 if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 /* Or that the server has 'lost' a cookie */
564 res = uncached_readdir(desc, dirent, filldir);
565 if (res >= 0)
566 continue;
567 }
568 res = 0;
569 break;
570 }
571 if (res == -ETOOSMALL && desc->plus) {
Chuck Lever412d5822005-08-18 11:24:11 -0700572 clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 nfs_zap_caches(inode);
574 desc->plus = 0;
575 desc->entry->eof = 0;
576 continue;
577 }
578 if (res < 0)
579 break;
580
581 res = nfs_do_filldir(desc, dirent, filldir);
582 if (res < 0) {
583 res = 0;
584 break;
585 }
586 }
587 unlock_kernel();
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500588 if (res > 0)
589 res = 0;
590 dfprintk(VFS, "NFS: readdir(%s/%s) returns %ld\n",
591 dentry->d_parent->d_name.name, dentry->d_name.name,
592 res);
593 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594}
595
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000596loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
597{
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800598 mutex_lock(&filp->f_dentry->d_inode->i_mutex);
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000599 switch (origin) {
600 case 1:
601 offset += filp->f_pos;
602 case 0:
603 if (offset >= 0)
604 break;
605 default:
606 offset = -EINVAL;
607 goto out;
608 }
609 if (offset != filp->f_pos) {
610 filp->f_pos = offset;
611 ((struct nfs_open_context *)filp->private_data)->dir_cookie = 0;
612 }
613out:
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800614 mutex_unlock(&filp->f_dentry->d_inode->i_mutex);
Trond Myklebustf0dd2132005-06-22 17:16:29 +0000615 return offset;
616}
617
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618/*
619 * All directory operations under NFS are synchronous, so fsync()
620 * is a dummy operation.
621 */
622int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync)
623{
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500624 dfprintk(VFS, "NFS: fsync_dir(%s/%s) datasync %d\n",
625 dentry->d_parent->d_name.name, dentry->d_name.name,
626 datasync);
627
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628 return 0;
629}
630
631/*
632 * A check for whether or not the parent directory has changed.
633 * In the case it has, we assume that the dentries are untrustworthy
634 * and may need to be looked up again.
635 */
636static inline int nfs_check_verifier(struct inode *dir, struct dentry *dentry)
637{
638 if (IS_ROOT(dentry))
639 return 1;
Chuck Lever55296802005-08-18 11:24:09 -0700640 if ((NFS_I(dir)->cache_validity & NFS_INO_INVALID_ATTR) != 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 || nfs_attribute_timeout(dir))
642 return 0;
643 return nfs_verify_change_attribute(dir, (unsigned long)dentry->d_fsdata);
644}
645
646static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf)
647{
648 dentry->d_fsdata = (void *)verf;
649}
650
651/*
652 * Whenever an NFS operation succeeds, we know that the dentry
653 * is valid, so we update the revalidation timestamp.
654 */
655static inline void nfs_renew_times(struct dentry * dentry)
656{
657 dentry->d_time = jiffies;
658}
659
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400660/*
661 * Return the intent data that applies to this particular path component
662 *
663 * Note that the current set of intents only apply to the very last
664 * component of the path.
665 * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT.
666 */
667static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask)
668{
669 if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))
670 return 0;
671 return nd->flags & mask;
672}
673
674/*
675 * Inode and filehandle revalidation for lookups.
676 *
677 * We force revalidation in the cases where the VFS sets LOOKUP_REVAL,
678 * or if the intent information indicates that we're about to open this
679 * particular file and the "nocto" mount flag is not set.
680 *
681 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682static inline
683int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd)
684{
685 struct nfs_server *server = NFS_SERVER(inode);
686
687 if (nd != NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 /* VFS wants an on-the-wire revalidation */
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400689 if (nd->flags & LOOKUP_REVAL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 goto out_force;
691 /* This is an open(2) */
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400692 if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 !(server->flags & NFS_MOUNT_NOCTO))
694 goto out_force;
695 }
696 return nfs_revalidate_inode(server, inode);
697out_force:
698 return __nfs_revalidate_inode(server, inode);
699}
700
701/*
702 * We judge how long we want to trust negative
703 * dentries by looking at the parent inode mtime.
704 *
705 * If parent mtime has changed, we revalidate, else we wait for a
706 * period corresponding to the parent's attribute cache timeout value.
707 */
708static inline
709int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry,
710 struct nameidata *nd)
711{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 /* Don't revalidate a negative dentry if we're creating a new file */
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400713 if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 return 0;
715 return !nfs_check_verifier(dir, dentry);
716}
717
718/*
719 * This is called every time the dcache has a lookup hit,
720 * and we should check whether we can really trust that
721 * lookup.
722 *
723 * NOTE! The hit can be a negative hit too, don't assume
724 * we have an inode!
725 *
726 * If the parent directory is seen to have changed, we throw out the
727 * cached dentry and do a new lookup.
728 */
729static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd)
730{
731 struct inode *dir;
732 struct inode *inode;
733 struct dentry *parent;
734 int error;
735 struct nfs_fh fhandle;
736 struct nfs_fattr fattr;
737 unsigned long verifier;
738
739 parent = dget_parent(dentry);
740 lock_kernel();
741 dir = parent->d_inode;
Chuck Lever91d5b472006-03-20 13:44:14 -0500742 nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 inode = dentry->d_inode;
744
745 if (!inode) {
746 if (nfs_neg_need_reval(dir, dentry, nd))
747 goto out_bad;
748 goto out_valid;
749 }
750
751 if (is_bad_inode(inode)) {
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500752 dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
753 __FUNCTION__, dentry->d_parent->d_name.name,
754 dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 goto out_bad;
756 }
757
758 /* Revalidate parent directory attribute cache */
759 if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0)
760 goto out_zap_parent;
761
762 /* Force a full look up iff the parent directory has changed */
763 if (nfs_check_verifier(dir, dentry)) {
764 if (nfs_lookup_verify_inode(inode, nd))
765 goto out_zap_parent;
766 goto out_valid;
767 }
768
769 if (NFS_STALE(inode))
770 goto out_bad;
771
772 verifier = nfs_save_change_attribute(dir);
773 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
774 if (error)
775 goto out_bad;
776 if (nfs_compare_fh(NFS_FH(inode), &fhandle))
777 goto out_bad;
778 if ((error = nfs_refresh_inode(inode, &fattr)) != 0)
779 goto out_bad;
780
781 nfs_renew_times(dentry);
782 nfs_set_verifier(dentry, verifier);
783 out_valid:
784 unlock_kernel();
785 dput(parent);
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500786 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n",
787 __FUNCTION__, dentry->d_parent->d_name.name,
788 dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 return 1;
790out_zap_parent:
791 nfs_zap_caches(dir);
792 out_bad:
793 NFS_CACHEINV(dir);
794 if (inode && S_ISDIR(inode->i_mode)) {
795 /* Purge readdir caches. */
796 nfs_zap_caches(inode);
797 /* If we have submounts, don't unhash ! */
798 if (have_submounts(dentry))
799 goto out_valid;
800 shrink_dcache_parent(dentry);
801 }
802 d_drop(dentry);
803 unlock_kernel();
804 dput(parent);
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500805 dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n",
806 __FUNCTION__, dentry->d_parent->d_name.name,
807 dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808 return 0;
809}
810
811/*
812 * This is called from dput() when d_count is going to 0.
813 */
814static int nfs_dentry_delete(struct dentry *dentry)
815{
816 dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n",
817 dentry->d_parent->d_name.name, dentry->d_name.name,
818 dentry->d_flags);
819
820 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
821 /* Unhash it, so that ->d_iput() would be called */
822 return 1;
823 }
824 if (!(dentry->d_sb->s_flags & MS_ACTIVE)) {
825 /* Unhash it, so that ancestors of killed async unlink
826 * files will be cleaned up during umount */
827 return 1;
828 }
829 return 0;
830
831}
832
833/*
834 * Called when the dentry loses inode.
835 * We use it to clean up silly-renamed files.
836 */
837static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode)
838{
Trond Myklebustcae7a072005-10-18 14:20:19 -0700839 nfs_inode_return_delegation(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
841 lock_kernel();
842 inode->i_nlink--;
843 nfs_complete_unlink(dentry);
844 unlock_kernel();
845 }
846 /* When creating a negative dentry, we want to renew d_time */
847 nfs_renew_times(dentry);
848 iput(inode);
849}
850
851struct dentry_operations nfs_dentry_operations = {
852 .d_revalidate = nfs_lookup_revalidate,
853 .d_delete = nfs_dentry_delete,
854 .d_iput = nfs_dentry_iput,
855};
856
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400857/*
858 * Use intent information to check whether or not we're going to do
859 * an O_EXCL create using this path component.
860 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861static inline
862int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd)
863{
864 if (NFS_PROTO(dir)->version == 2)
865 return 0;
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400866 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 return 0;
868 return (nd->intent.open.flags & O_EXCL) != 0;
869}
870
871static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
872{
873 struct dentry *res;
874 struct inode *inode = NULL;
875 int error;
876 struct nfs_fh fhandle;
877 struct nfs_fattr fattr;
878
879 dfprintk(VFS, "NFS: lookup(%s/%s)\n",
880 dentry->d_parent->d_name.name, dentry->d_name.name);
Chuck Lever91d5b472006-03-20 13:44:14 -0500881 nfs_inc_stats(dir, NFSIOS_VFSLOOKUP);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882
883 res = ERR_PTR(-ENAMETOOLONG);
884 if (dentry->d_name.len > NFS_SERVER(dir)->namelen)
885 goto out;
886
887 res = ERR_PTR(-ENOMEM);
888 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
889
890 lock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
892 /* If we're doing an exclusive create, optimize away the lookup */
893 if (nfs_is_exclusive_create(dir, nd))
894 goto no_entry;
895
896 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr);
897 if (error == -ENOENT)
898 goto no_entry;
899 if (error < 0) {
900 res = ERR_PTR(error);
901 goto out_unlock;
902 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903 inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr);
Trond Myklebust03f28e32006-03-20 13:44:48 -0500904 res = (struct dentry *)inode;
905 if (IS_ERR(res))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 goto out_unlock;
907no_entry:
908 res = d_add_unique(dentry, inode);
909 if (res != NULL)
910 dentry = res;
911 nfs_renew_times(dentry);
912 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
913out_unlock:
914 unlock_kernel();
915out:
916 return res;
917}
918
919#ifdef CONFIG_NFS_V4
920static int nfs_open_revalidate(struct dentry *, struct nameidata *);
921
922struct dentry_operations nfs4_dentry_operations = {
923 .d_revalidate = nfs_open_revalidate,
924 .d_delete = nfs_dentry_delete,
925 .d_iput = nfs_dentry_iput,
926};
927
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400928/*
929 * Use intent information to determine whether we need to substitute
930 * the NFSv4-style stateful OPEN for the LOOKUP call
931 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932static int is_atomic_open(struct inode *dir, struct nameidata *nd)
933{
Trond Myklebust1d6757f2005-06-07 18:37:01 -0400934 if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 return 0;
936 /* NFS does not (yet) have a stateful open for directories */
937 if (nd->flags & LOOKUP_DIRECTORY)
938 return 0;
939 /* Are we trying to write to a read only partition? */
940 if (IS_RDONLY(dir) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE)))
941 return 0;
942 return 1;
943}
944
945static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
946{
947 struct dentry *res = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 int error;
949
Chuck Lever1e7cb3d2006-03-20 13:44:24 -0500950 dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n",
951 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
952
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 /* Check that we are indeed trying to open this file */
954 if (!is_atomic_open(dir, nd))
955 goto no_open;
956
957 if (dentry->d_name.len > NFS_SERVER(dir)->namelen) {
958 res = ERR_PTR(-ENAMETOOLONG);
959 goto out;
960 }
961 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
962
963 /* Let vfs_create() deal with O_EXCL */
Trond Myklebust02a913a2005-10-18 14:20:17 -0700964 if (nd->intent.open.flags & O_EXCL) {
965 d_add(dentry, NULL);
966 goto out;
967 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
969 /* Open the file on the server */
970 lock_kernel();
971 /* Revalidate parent directory attribute cache */
972 error = nfs_revalidate_inode(NFS_SERVER(dir), dir);
973 if (error < 0) {
974 res = ERR_PTR(error);
Steve Dickson01c314a2005-08-19 17:57:48 -0700975 unlock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 goto out;
977 }
978
979 if (nd->intent.open.flags & O_CREAT) {
980 nfs_begin_data_update(dir);
Trond Myklebust02a913a2005-10-18 14:20:17 -0700981 res = nfs4_atomic_open(dir, dentry, nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 nfs_end_data_update(dir);
983 } else
Trond Myklebust02a913a2005-10-18 14:20:17 -0700984 res = nfs4_atomic_open(dir, dentry, nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700985 unlock_kernel();
Trond Myklebust02a913a2005-10-18 14:20:17 -0700986 if (IS_ERR(res)) {
987 error = PTR_ERR(res);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700988 switch (error) {
989 /* Make a negative dentry */
990 case -ENOENT:
Trond Myklebust02a913a2005-10-18 14:20:17 -0700991 res = NULL;
992 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 /* This turned out not to be a regular file */
Trond Myklebust6f926b52005-10-18 14:20:18 -0700994 case -EISDIR:
995 case -ENOTDIR:
996 goto no_open;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 case -ELOOP:
998 if (!(nd->intent.open.flags & O_NOFOLLOW))
999 goto no_open;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 /* case -EINVAL: */
1001 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 goto out;
1003 }
Trond Myklebust02a913a2005-10-18 14:20:17 -07001004 } else if (res != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005 dentry = res;
1006 nfs_renew_times(dentry);
1007 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1008out:
1009 return res;
1010no_open:
1011 return nfs_lookup(dir, dentry, nd);
1012}
1013
1014static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
1015{
1016 struct dentry *parent = NULL;
1017 struct inode *inode = dentry->d_inode;
1018 struct inode *dir;
1019 unsigned long verifier;
1020 int openflags, ret = 0;
1021
1022 parent = dget_parent(dentry);
1023 dir = parent->d_inode;
1024 if (!is_atomic_open(dir, nd))
1025 goto no_open;
1026 /* We can't create new files in nfs_open_revalidate(), so we
1027 * optimize away revalidation of negative dentries.
1028 */
1029 if (inode == NULL)
1030 goto out;
1031 /* NFS only supports OPEN on regular files */
1032 if (!S_ISREG(inode->i_mode))
1033 goto no_open;
1034 openflags = nd->intent.open.flags;
1035 /* We cannot do exclusive creation on a positive dentry */
1036 if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL))
1037 goto no_open;
1038 /* We can't create new files, or truncate existing ones here */
1039 openflags &= ~(O_CREAT|O_TRUNC);
1040
1041 /*
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001042 * Note: we're not holding inode->i_mutex and so may be racing with
Linus Torvalds1da177e2005-04-16 15:20:36 -07001043 * operations that change the directory. We therefore save the
1044 * change attribute *before* we do the RPC call.
1045 */
1046 lock_kernel();
1047 verifier = nfs_save_change_attribute(dir);
Trond Myklebust02a913a2005-10-18 14:20:17 -07001048 ret = nfs4_open_revalidate(dir, dentry, openflags, nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 if (!ret)
1050 nfs_set_verifier(dentry, verifier);
1051 unlock_kernel();
1052out:
1053 dput(parent);
1054 if (!ret)
1055 d_drop(dentry);
1056 return ret;
1057no_open:
1058 dput(parent);
1059 if (inode != NULL && nfs_have_delegation(inode, FMODE_READ))
1060 return 1;
1061 return nfs_lookup_revalidate(dentry, nd);
1062}
1063#endif /* CONFIG_NFSV4 */
1064
1065static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc)
1066{
1067 struct dentry *parent = desc->file->f_dentry;
1068 struct inode *dir = parent->d_inode;
1069 struct nfs_entry *entry = desc->entry;
1070 struct dentry *dentry, *alias;
1071 struct qstr name = {
1072 .name = entry->name,
1073 .len = entry->len,
1074 };
1075 struct inode *inode;
1076
1077 switch (name.len) {
1078 case 2:
1079 if (name.name[0] == '.' && name.name[1] == '.')
1080 return dget_parent(parent);
1081 break;
1082 case 1:
1083 if (name.name[0] == '.')
1084 return dget(parent);
1085 }
1086 name.hash = full_name_hash(name.name, name.len);
1087 dentry = d_lookup(parent, &name);
1088 if (dentry != NULL)
1089 return dentry;
1090 if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR))
1091 return NULL;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -08001092 /* Note: caller is already holding the dir->i_mutex! */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 dentry = d_alloc(parent, &name);
1094 if (dentry == NULL)
1095 return NULL;
1096 dentry->d_op = NFS_PROTO(dir)->dentry_ops;
1097 inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr);
Trond Myklebust03f28e32006-03-20 13:44:48 -05001098 if (IS_ERR(inode)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 dput(dentry);
1100 return NULL;
1101 }
1102 alias = d_add_unique(dentry, inode);
1103 if (alias != NULL) {
1104 dput(dentry);
1105 dentry = alias;
1106 }
1107 nfs_renew_times(dentry);
1108 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1109 return dentry;
1110}
1111
1112/*
1113 * Code common to create, mkdir, and mknod.
1114 */
1115int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle,
1116 struct nfs_fattr *fattr)
1117{
1118 struct inode *inode;
1119 int error = -EACCES;
1120
1121 /* We may have been initialized further down */
1122 if (dentry->d_inode)
1123 return 0;
1124 if (fhandle->size == 0) {
1125 struct inode *dir = dentry->d_parent->d_inode;
1126 error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr);
1127 if (error)
1128 goto out_err;
1129 }
1130 if (!(fattr->valid & NFS_ATTR_FATTR)) {
1131 struct nfs_server *server = NFS_SB(dentry->d_sb);
1132 error = server->rpc_ops->getattr(server, fhandle, fattr);
1133 if (error < 0)
1134 goto out_err;
1135 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001136 inode = nfs_fhget(dentry->d_sb, fhandle, fattr);
Trond Myklebust03f28e32006-03-20 13:44:48 -05001137 error = PTR_ERR(inode);
1138 if (IS_ERR(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 goto out_err;
1140 d_instantiate(dentry, inode);
1141 return 0;
1142out_err:
1143 d_drop(dentry);
1144 return error;
1145}
1146
1147/*
1148 * Following a failed create operation, we drop the dentry rather
1149 * than retain a negative dentry. This avoids a problem in the event
1150 * that the operation succeeded on the server, but an error in the
1151 * reply path made it appear to have failed.
1152 */
1153static int nfs_create(struct inode *dir, struct dentry *dentry, int mode,
1154 struct nameidata *nd)
1155{
1156 struct iattr attr;
1157 int error;
1158 int open_flags = 0;
1159
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001160 dfprintk(VFS, "NFS: create(%s/%ld), %s\n",
1161 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001162
1163 attr.ia_mode = mode;
1164 attr.ia_valid = ATTR_MODE;
1165
1166 if (nd && (nd->flags & LOOKUP_CREATE))
1167 open_flags = nd->intent.open.flags;
1168
1169 lock_kernel();
1170 nfs_begin_data_update(dir);
Trond Myklebust02a913a2005-10-18 14:20:17 -07001171 error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, nd);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 nfs_end_data_update(dir);
1173 if (error != 0)
1174 goto out_err;
1175 nfs_renew_times(dentry);
1176 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1177 unlock_kernel();
1178 return 0;
1179out_err:
1180 unlock_kernel();
1181 d_drop(dentry);
1182 return error;
1183}
1184
1185/*
1186 * See comments for nfs_proc_create regarding failed operations.
1187 */
1188static int
1189nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1190{
1191 struct iattr attr;
1192 int status;
1193
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001194 dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n",
1195 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001196
1197 if (!new_valid_dev(rdev))
1198 return -EINVAL;
1199
1200 attr.ia_mode = mode;
1201 attr.ia_valid = ATTR_MODE;
1202
1203 lock_kernel();
1204 nfs_begin_data_update(dir);
1205 status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev);
1206 nfs_end_data_update(dir);
1207 if (status != 0)
1208 goto out_err;
1209 nfs_renew_times(dentry);
1210 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1211 unlock_kernel();
1212 return 0;
1213out_err:
1214 unlock_kernel();
1215 d_drop(dentry);
1216 return status;
1217}
1218
1219/*
1220 * See comments for nfs_proc_create regarding failed operations.
1221 */
1222static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
1223{
1224 struct iattr attr;
1225 int error;
1226
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001227 dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n",
1228 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229
1230 attr.ia_valid = ATTR_MODE;
1231 attr.ia_mode = mode | S_IFDIR;
1232
1233 lock_kernel();
1234 nfs_begin_data_update(dir);
1235 error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr);
1236 nfs_end_data_update(dir);
1237 if (error != 0)
1238 goto out_err;
1239 nfs_renew_times(dentry);
1240 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1241 unlock_kernel();
1242 return 0;
1243out_err:
1244 d_drop(dentry);
1245 unlock_kernel();
1246 return error;
1247}
1248
1249static int nfs_rmdir(struct inode *dir, struct dentry *dentry)
1250{
1251 int error;
1252
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001253 dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n",
1254 dir->i_sb->s_id, dir->i_ino, dentry->d_name.name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255
1256 lock_kernel();
1257 nfs_begin_data_update(dir);
1258 error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name);
1259 /* Ensure the VFS deletes this inode */
1260 if (error == 0 && dentry->d_inode != NULL)
1261 dentry->d_inode->i_nlink = 0;
1262 nfs_end_data_update(dir);
1263 unlock_kernel();
1264
1265 return error;
1266}
1267
1268static int nfs_sillyrename(struct inode *dir, struct dentry *dentry)
1269{
1270 static unsigned int sillycounter;
1271 const int i_inosize = sizeof(dir->i_ino)*2;
1272 const int countersize = sizeof(sillycounter)*2;
1273 const int slen = sizeof(".nfs") + i_inosize + countersize - 1;
1274 char silly[slen+1];
1275 struct qstr qsilly;
1276 struct dentry *sdentry;
1277 int error = -EIO;
1278
1279 dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n",
1280 dentry->d_parent->d_name.name, dentry->d_name.name,
1281 atomic_read(&dentry->d_count));
Chuck Lever91d5b472006-03-20 13:44:14 -05001282 nfs_inc_stats(dir, NFSIOS_SILLYRENAME);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283
1284#ifdef NFS_PARANOIA
1285if (!dentry->d_inode)
1286printk("NFS: silly-renaming %s/%s, negative dentry??\n",
1287dentry->d_parent->d_name.name, dentry->d_name.name);
1288#endif
1289 /*
1290 * We don't allow a dentry to be silly-renamed twice.
1291 */
1292 error = -EBUSY;
1293 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
1294 goto out;
1295
1296 sprintf(silly, ".nfs%*.*lx",
1297 i_inosize, i_inosize, dentry->d_inode->i_ino);
1298
Trond Myklebust34ea8182005-11-04 15:35:02 -05001299 /* Return delegation in anticipation of the rename */
1300 nfs_inode_return_delegation(dentry->d_inode);
1301
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 sdentry = NULL;
1303 do {
1304 char *suffix = silly + slen - countersize;
1305
1306 dput(sdentry);
1307 sillycounter++;
1308 sprintf(suffix, "%*.*x", countersize, countersize, sillycounter);
1309
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001310 dfprintk(VFS, "NFS: trying to rename %s to %s\n",
1311 dentry->d_name.name, silly);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312
1313 sdentry = lookup_one_len(silly, dentry->d_parent, slen);
1314 /*
1315 * N.B. Better to return EBUSY here ... it could be
1316 * dangerous to delete the file while it's in use.
1317 */
1318 if (IS_ERR(sdentry))
1319 goto out;
1320 } while(sdentry->d_inode != NULL); /* need negative lookup */
1321
1322 qsilly.name = silly;
1323 qsilly.len = strlen(silly);
1324 nfs_begin_data_update(dir);
1325 if (dentry->d_inode) {
1326 nfs_begin_data_update(dentry->d_inode);
1327 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1328 dir, &qsilly);
Trond Myklebust5ba7cc42005-12-03 15:20:17 -05001329 nfs_mark_for_revalidate(dentry->d_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 nfs_end_data_update(dentry->d_inode);
1331 } else
1332 error = NFS_PROTO(dir)->rename(dir, &dentry->d_name,
1333 dir, &qsilly);
1334 nfs_end_data_update(dir);
1335 if (!error) {
1336 nfs_renew_times(dentry);
1337 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1338 d_move(dentry, sdentry);
1339 error = nfs_async_unlink(dentry);
1340 /* If we return 0 we don't unlink */
1341 }
1342 dput(sdentry);
1343out:
1344 return error;
1345}
1346
1347/*
1348 * Remove a file after making sure there are no pending writes,
1349 * and after checking that the file has only one user.
1350 *
1351 * We invalidate the attribute cache and free the inode prior to the operation
1352 * to avoid possible races if the server reuses the inode.
1353 */
1354static int nfs_safe_remove(struct dentry *dentry)
1355{
1356 struct inode *dir = dentry->d_parent->d_inode;
1357 struct inode *inode = dentry->d_inode;
1358 int error = -EBUSY;
1359
1360 dfprintk(VFS, "NFS: safe_remove(%s/%s)\n",
1361 dentry->d_parent->d_name.name, dentry->d_name.name);
1362
1363 /* If the dentry was sillyrenamed, we simply call d_delete() */
1364 if (dentry->d_flags & DCACHE_NFSFS_RENAMED) {
1365 error = 0;
1366 goto out;
1367 }
1368
1369 nfs_begin_data_update(dir);
1370 if (inode != NULL) {
Trond Myklebustcae7a072005-10-18 14:20:19 -07001371 nfs_inode_return_delegation(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001372 nfs_begin_data_update(inode);
1373 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1374 /* The VFS may want to delete this inode */
1375 if (error == 0)
1376 inode->i_nlink--;
Trond Myklebust5ba7cc42005-12-03 15:20:17 -05001377 nfs_mark_for_revalidate(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001378 nfs_end_data_update(inode);
1379 } else
1380 error = NFS_PROTO(dir)->remove(dir, &dentry->d_name);
1381 nfs_end_data_update(dir);
1382out:
1383 return error;
1384}
1385
1386/* We do silly rename. In case sillyrename() returns -EBUSY, the inode
1387 * belongs to an active ".nfs..." file and we return -EBUSY.
1388 *
1389 * If sillyrename() returns 0, we do nothing, otherwise we unlink.
1390 */
1391static int nfs_unlink(struct inode *dir, struct dentry *dentry)
1392{
1393 int error;
1394 int need_rehash = 0;
1395
1396 dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id,
1397 dir->i_ino, dentry->d_name.name);
1398
1399 lock_kernel();
1400 spin_lock(&dcache_lock);
1401 spin_lock(&dentry->d_lock);
1402 if (atomic_read(&dentry->d_count) > 1) {
1403 spin_unlock(&dentry->d_lock);
1404 spin_unlock(&dcache_lock);
1405 error = nfs_sillyrename(dir, dentry);
1406 unlock_kernel();
1407 return error;
1408 }
1409 if (!d_unhashed(dentry)) {
1410 __d_drop(dentry);
1411 need_rehash = 1;
1412 }
1413 spin_unlock(&dentry->d_lock);
1414 spin_unlock(&dcache_lock);
1415 error = nfs_safe_remove(dentry);
1416 if (!error) {
1417 nfs_renew_times(dentry);
1418 nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
1419 } else if (need_rehash)
1420 d_rehash(dentry);
1421 unlock_kernel();
1422 return error;
1423}
1424
1425static int
1426nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1427{
1428 struct iattr attr;
1429 struct nfs_fattr sym_attr;
1430 struct nfs_fh sym_fh;
1431 struct qstr qsymname;
1432 int error;
1433
1434 dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id,
1435 dir->i_ino, dentry->d_name.name, symname);
1436
1437#ifdef NFS_PARANOIA
1438if (dentry->d_inode)
1439printk("nfs_proc_symlink: %s/%s not negative!\n",
1440dentry->d_parent->d_name.name, dentry->d_name.name);
1441#endif
1442 /*
1443 * Fill in the sattr for the call.
1444 * Note: SunOS 4.1.2 crashes if the mode isn't initialized!
1445 */
1446 attr.ia_valid = ATTR_MODE;
1447 attr.ia_mode = S_IFLNK | S_IRWXUGO;
1448
1449 qsymname.name = symname;
1450 qsymname.len = strlen(symname);
1451
1452 lock_kernel();
1453 nfs_begin_data_update(dir);
1454 error = NFS_PROTO(dir)->symlink(dir, &dentry->d_name, &qsymname,
1455 &attr, &sym_fh, &sym_attr);
1456 nfs_end_data_update(dir);
1457 if (!error) {
1458 error = nfs_instantiate(dentry, &sym_fh, &sym_attr);
1459 } else {
1460 if (error == -EEXIST)
1461 printk("nfs_proc_symlink: %s/%s already exists??\n",
1462 dentry->d_parent->d_name.name, dentry->d_name.name);
1463 d_drop(dentry);
1464 }
1465 unlock_kernel();
1466 return error;
1467}
1468
1469static int
1470nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
1471{
1472 struct inode *inode = old_dentry->d_inode;
1473 int error;
1474
1475 dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n",
1476 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1477 dentry->d_parent->d_name.name, dentry->d_name.name);
1478
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479 lock_kernel();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001480 nfs_begin_data_update(dir);
1481 nfs_begin_data_update(inode);
1482 error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name);
Trond Myklebustcf809552005-10-27 22:12:42 -04001483 if (error == 0) {
1484 atomic_inc(&inode->i_count);
1485 d_instantiate(dentry, inode);
1486 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001487 nfs_end_data_update(inode);
1488 nfs_end_data_update(dir);
1489 unlock_kernel();
1490 return error;
1491}
1492
1493/*
1494 * RENAME
1495 * FIXME: Some nfsds, like the Linux user space nfsd, may generate a
1496 * different file handle for the same inode after a rename (e.g. when
1497 * moving to a different directory). A fail-safe method to do so would
1498 * be to look up old_dir/old_name, create a link to new_dir/new_name and
1499 * rename the old file using the sillyrename stuff. This way, the original
1500 * file in old_dir will go away when the last process iput()s the inode.
1501 *
1502 * FIXED.
1503 *
1504 * It actually works quite well. One needs to have the possibility for
1505 * at least one ".nfs..." file in each directory the file ever gets
1506 * moved or linked to which happens automagically with the new
1507 * implementation that only depends on the dcache stuff instead of
1508 * using the inode layer
1509 *
1510 * Unfortunately, things are a little more complicated than indicated
1511 * above. For a cross-directory move, we want to make sure we can get
1512 * rid of the old inode after the operation. This means there must be
1513 * no pending writes (if it's a file), and the use count must be 1.
1514 * If these conditions are met, we can drop the dentries before doing
1515 * the rename.
1516 */
1517static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry,
1518 struct inode *new_dir, struct dentry *new_dentry)
1519{
1520 struct inode *old_inode = old_dentry->d_inode;
1521 struct inode *new_inode = new_dentry->d_inode;
1522 struct dentry *dentry = NULL, *rehash = NULL;
1523 int error = -EBUSY;
1524
1525 /*
1526 * To prevent any new references to the target during the rename,
1527 * we unhash the dentry and free the inode in advance.
1528 */
1529 lock_kernel();
1530 if (!d_unhashed(new_dentry)) {
1531 d_drop(new_dentry);
1532 rehash = new_dentry;
1533 }
1534
1535 dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n",
1536 old_dentry->d_parent->d_name.name, old_dentry->d_name.name,
1537 new_dentry->d_parent->d_name.name, new_dentry->d_name.name,
1538 atomic_read(&new_dentry->d_count));
1539
1540 /*
1541 * First check whether the target is busy ... we can't
1542 * safely do _any_ rename if the target is in use.
1543 *
1544 * For files, make a copy of the dentry and then do a
1545 * silly-rename. If the silly-rename succeeds, the
1546 * copied dentry is hashed and becomes the new target.
1547 */
1548 if (!new_inode)
1549 goto go_ahead;
Trond Myklebust6fe43f92005-10-18 14:20:22 -07001550 if (S_ISDIR(new_inode->i_mode)) {
1551 error = -EISDIR;
1552 if (!S_ISDIR(old_inode->i_mode))
1553 goto out;
1554 } else if (atomic_read(&new_dentry->d_count) > 2) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001555 int err;
1556 /* copy the target dentry's name */
1557 dentry = d_alloc(new_dentry->d_parent,
1558 &new_dentry->d_name);
1559 if (!dentry)
1560 goto out;
1561
1562 /* silly-rename the existing target ... */
1563 err = nfs_sillyrename(new_dir, new_dentry);
1564 if (!err) {
1565 new_dentry = rehash = dentry;
1566 new_inode = NULL;
1567 /* instantiate the replacement target */
1568 d_instantiate(new_dentry, NULL);
1569 } else if (atomic_read(&new_dentry->d_count) > 1) {
1570 /* dentry still busy? */
1571#ifdef NFS_PARANOIA
1572 printk("nfs_rename: target %s/%s busy, d_count=%d\n",
1573 new_dentry->d_parent->d_name.name,
1574 new_dentry->d_name.name,
1575 atomic_read(&new_dentry->d_count));
1576#endif
1577 goto out;
1578 }
Trond Myklebust20509f12005-08-25 16:25:34 -07001579 } else
1580 new_inode->i_nlink--;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001581
1582go_ahead:
1583 /*
1584 * ... prune child dentries and writebacks if needed.
1585 */
1586 if (atomic_read(&old_dentry->d_count) > 1) {
1587 nfs_wb_all(old_inode);
1588 shrink_dcache_parent(old_dentry);
1589 }
Trond Myklebustcae7a072005-10-18 14:20:19 -07001590 nfs_inode_return_delegation(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591
Trond Myklebust24174112006-01-03 09:55:33 +01001592 if (new_inode != NULL) {
1593 nfs_inode_return_delegation(new_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001594 d_delete(new_dentry);
Trond Myklebust24174112006-01-03 09:55:33 +01001595 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001596
1597 nfs_begin_data_update(old_dir);
1598 nfs_begin_data_update(new_dir);
1599 nfs_begin_data_update(old_inode);
1600 error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name,
1601 new_dir, &new_dentry->d_name);
Trond Myklebust5ba7cc42005-12-03 15:20:17 -05001602 nfs_mark_for_revalidate(old_inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603 nfs_end_data_update(old_inode);
1604 nfs_end_data_update(new_dir);
1605 nfs_end_data_update(old_dir);
1606out:
1607 if (rehash)
1608 d_rehash(rehash);
1609 if (!error) {
1610 if (!S_ISDIR(old_inode->i_mode))
1611 d_move(old_dentry, new_dentry);
1612 nfs_renew_times(new_dentry);
1613 nfs_set_verifier(new_dentry, nfs_save_change_attribute(new_dir));
1614 }
1615
1616 /* new dentry created? */
1617 if (dentry)
1618 dput(dentry);
1619 unlock_kernel();
1620 return error;
1621}
1622
1623int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res)
1624{
Chuck Lever55296802005-08-18 11:24:09 -07001625 struct nfs_inode *nfsi = NFS_I(inode);
1626 struct nfs_access_entry *cache = &nfsi->cache_access;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001627
1628 if (cache->cred != cred
1629 || time_after(jiffies, cache->jiffies + NFS_ATTRTIMEO(inode))
Chuck Lever55296802005-08-18 11:24:09 -07001630 || (nfsi->cache_validity & NFS_INO_INVALID_ACCESS))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 return -ENOENT;
1632 memcpy(res, cache, sizeof(*res));
1633 return 0;
1634}
1635
1636void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set)
1637{
Chuck Lever55296802005-08-18 11:24:09 -07001638 struct nfs_inode *nfsi = NFS_I(inode);
1639 struct nfs_access_entry *cache = &nfsi->cache_access;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640
1641 if (cache->cred != set->cred) {
1642 if (cache->cred)
1643 put_rpccred(cache->cred);
1644 cache->cred = get_rpccred(set->cred);
1645 }
Chuck Leverdc592502005-08-18 11:24:12 -07001646 /* FIXME: replace current access_cache BKL reliance with inode->i_lock */
1647 spin_lock(&inode->i_lock);
Chuck Lever55296802005-08-18 11:24:09 -07001648 nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS;
Chuck Leverdc592502005-08-18 11:24:12 -07001649 spin_unlock(&inode->i_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001650 cache->jiffies = set->jiffies;
1651 cache->mask = set->mask;
1652}
1653
1654static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask)
1655{
1656 struct nfs_access_entry cache;
1657 int status;
1658
1659 status = nfs_access_get_cached(inode, cred, &cache);
1660 if (status == 0)
1661 goto out;
1662
1663 /* Be clever: ask server to check for all possible rights */
1664 cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ;
1665 cache.cred = cred;
1666 cache.jiffies = jiffies;
1667 status = NFS_PROTO(inode)->access(inode, &cache);
1668 if (status != 0)
1669 return status;
1670 nfs_access_add_cache(inode, &cache);
1671out:
1672 if ((cache.mask & mask) == mask)
1673 return 0;
1674 return -EACCES;
1675}
1676
1677int nfs_permission(struct inode *inode, int mask, struct nameidata *nd)
1678{
1679 struct rpc_cred *cred;
1680 int res = 0;
1681
Chuck Lever91d5b472006-03-20 13:44:14 -05001682 nfs_inc_stats(inode, NFSIOS_VFSACCESS);
1683
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684 if (mask == 0)
1685 goto out;
1686 /* Is this sys_access() ? */
1687 if (nd != NULL && (nd->flags & LOOKUP_ACCESS))
1688 goto force_lookup;
1689
1690 switch (inode->i_mode & S_IFMT) {
1691 case S_IFLNK:
1692 goto out;
1693 case S_IFREG:
1694 /* NFSv4 has atomic_open... */
1695 if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN)
1696 && nd != NULL
1697 && (nd->flags & LOOKUP_OPEN))
1698 goto out;
1699 break;
1700 case S_IFDIR:
1701 /*
1702 * Optimize away all write operations, since the server
1703 * will check permissions when we perform the op.
1704 */
1705 if ((mask & MAY_WRITE) && !(mask & MAY_READ))
1706 goto out;
1707 }
1708
1709force_lookup:
1710 lock_kernel();
1711
1712 if (!NFS_PROTO(inode)->access)
1713 goto out_notsup;
1714
1715 cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0);
1716 if (!IS_ERR(cred)) {
1717 res = nfs_do_access(inode, cred, mask);
1718 put_rpccred(cred);
1719 } else
1720 res = PTR_ERR(cred);
1721 unlock_kernel();
1722out:
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001723 dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n",
1724 inode->i_sb->s_id, inode->i_ino, mask, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725 return res;
1726out_notsup:
1727 res = nfs_revalidate_inode(NFS_SERVER(inode), inode);
1728 if (res == 0)
1729 res = generic_permission(inode, mask, NULL);
1730 unlock_kernel();
Chuck Lever1e7cb3d2006-03-20 13:44:24 -05001731 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732}
1733
1734/*
1735 * Local variables:
1736 * version-control: t
1737 * kept-new-versions: 5
1738 * End:
1739 */