Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
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 | ||
4ce79717 | 35 | #include "nfs4_fs.h" |
1da177e4 LT |
36 | #include "delegation.h" |
37 | ||
38 | #define NFS_PARANOIA 1 | |
39 | /* #define NFS_DEBUG_VERBOSE 1 */ | |
40 | ||
41 | static int nfs_opendir(struct inode *, struct file *); | |
42 | static int nfs_readdir(struct file *, void *, filldir_t); | |
43 | static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *); | |
44 | static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *); | |
45 | static int nfs_mkdir(struct inode *, struct dentry *, int); | |
46 | static int nfs_rmdir(struct inode *, struct dentry *); | |
47 | static int nfs_unlink(struct inode *, struct dentry *); | |
48 | static int nfs_symlink(struct inode *, struct dentry *, const char *); | |
49 | static int nfs_link(struct dentry *, struct inode *, struct dentry *); | |
50 | static int nfs_mknod(struct inode *, struct dentry *, int, dev_t); | |
51 | static int nfs_rename(struct inode *, struct dentry *, | |
52 | struct inode *, struct dentry *); | |
53 | static int nfs_fsync_dir(struct file *, struct dentry *, int); | |
f0dd2136 | 54 | static loff_t nfs_llseek_dir(struct file *, loff_t, int); |
1da177e4 LT |
55 | |
56 | struct file_operations nfs_dir_operations = { | |
f0dd2136 | 57 | .llseek = nfs_llseek_dir, |
1da177e4 LT |
58 | .read = generic_read_dir, |
59 | .readdir = nfs_readdir, | |
60 | .open = nfs_opendir, | |
61 | .release = nfs_release, | |
62 | .fsync = nfs_fsync_dir, | |
63 | }; | |
64 | ||
65 | struct inode_operations nfs_dir_inode_operations = { | |
66 | .create = nfs_create, | |
67 | .lookup = nfs_lookup, | |
68 | .link = nfs_link, | |
69 | .unlink = nfs_unlink, | |
70 | .symlink = nfs_symlink, | |
71 | .mkdir = nfs_mkdir, | |
72 | .rmdir = nfs_rmdir, | |
73 | .mknod = nfs_mknod, | |
74 | .rename = nfs_rename, | |
75 | .permission = nfs_permission, | |
76 | .getattr = nfs_getattr, | |
77 | .setattr = nfs_setattr, | |
78 | }; | |
79 | ||
b7fa0554 AG |
80 | #ifdef CONFIG_NFS_V3 |
81 | struct inode_operations nfs3_dir_inode_operations = { | |
82 | .create = nfs_create, | |
83 | .lookup = nfs_lookup, | |
84 | .link = nfs_link, | |
85 | .unlink = nfs_unlink, | |
86 | .symlink = nfs_symlink, | |
87 | .mkdir = nfs_mkdir, | |
88 | .rmdir = nfs_rmdir, | |
89 | .mknod = nfs_mknod, | |
90 | .rename = nfs_rename, | |
91 | .permission = nfs_permission, | |
92 | .getattr = nfs_getattr, | |
93 | .setattr = nfs_setattr, | |
94 | .listxattr = nfs3_listxattr, | |
95 | .getxattr = nfs3_getxattr, | |
96 | .setxattr = nfs3_setxattr, | |
97 | .removexattr = nfs3_removexattr, | |
98 | }; | |
99 | #endif /* CONFIG_NFS_V3 */ | |
100 | ||
1da177e4 LT |
101 | #ifdef CONFIG_NFS_V4 |
102 | ||
103 | static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *); | |
104 | struct inode_operations nfs4_dir_inode_operations = { | |
105 | .create = nfs_create, | |
106 | .lookup = nfs_atomic_lookup, | |
107 | .link = nfs_link, | |
108 | .unlink = nfs_unlink, | |
109 | .symlink = nfs_symlink, | |
110 | .mkdir = nfs_mkdir, | |
111 | .rmdir = nfs_rmdir, | |
112 | .mknod = nfs_mknod, | |
113 | .rename = nfs_rename, | |
114 | .permission = nfs_permission, | |
115 | .getattr = nfs_getattr, | |
116 | .setattr = nfs_setattr, | |
6b3b5496 BF |
117 | .getxattr = nfs4_getxattr, |
118 | .setxattr = nfs4_setxattr, | |
119 | .listxattr = nfs4_listxattr, | |
1da177e4 LT |
120 | }; |
121 | ||
122 | #endif /* CONFIG_NFS_V4 */ | |
123 | ||
124 | /* | |
125 | * Open file | |
126 | */ | |
127 | static int | |
128 | nfs_opendir(struct inode *inode, struct file *filp) | |
129 | { | |
130 | int res = 0; | |
131 | ||
132 | lock_kernel(); | |
133 | /* Call generic open code in order to cache credentials */ | |
134 | if (!res) | |
135 | res = nfs_open(inode, filp); | |
136 | unlock_kernel(); | |
137 | return res; | |
138 | } | |
139 | ||
140 | typedef u32 * (*decode_dirent_t)(u32 *, struct nfs_entry *, int); | |
141 | typedef struct { | |
142 | struct file *file; | |
143 | struct page *page; | |
144 | unsigned long page_index; | |
145 | u32 *ptr; | |
f0dd2136 TM |
146 | u64 *dir_cookie; |
147 | loff_t current_index; | |
1da177e4 LT |
148 | struct nfs_entry *entry; |
149 | decode_dirent_t decode; | |
150 | int plus; | |
151 | int error; | |
152 | } nfs_readdir_descriptor_t; | |
153 | ||
154 | /* Now we cache directories properly, by stuffing the dirent | |
155 | * data directly in the page cache. | |
156 | * | |
157 | * Inode invalidation due to refresh etc. takes care of | |
158 | * _everything_, no sloppy entry flushing logic, no extraneous | |
159 | * copying, network direct to page cache, the way it was meant | |
160 | * to be. | |
161 | * | |
162 | * NOTE: Dirent information verification is done always by the | |
163 | * page-in of the RPC reply, nowhere else, this simplies | |
164 | * things substantially. | |
165 | */ | |
166 | static | |
167 | int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page) | |
168 | { | |
169 | struct file *file = desc->file; | |
170 | struct inode *inode = file->f_dentry->d_inode; | |
171 | struct rpc_cred *cred = nfs_file_cred(file); | |
172 | unsigned long timestamp; | |
173 | int error; | |
174 | ||
175 | dfprintk(VFS, "NFS: nfs_readdir_filler() reading cookie %Lu into page %lu.\n", (long long)desc->entry->cookie, page->index); | |
176 | ||
177 | again: | |
178 | timestamp = jiffies; | |
179 | error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, desc->entry->cookie, page, | |
180 | NFS_SERVER(inode)->dtsize, desc->plus); | |
181 | if (error < 0) { | |
182 | /* We requested READDIRPLUS, but the server doesn't grok it */ | |
183 | if (error == -ENOTSUPP && desc->plus) { | |
184 | NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; | |
412d582e | 185 | clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); |
1da177e4 LT |
186 | desc->plus = 0; |
187 | goto again; | |
188 | } | |
189 | goto error; | |
190 | } | |
191 | SetPageUptodate(page); | |
55296809 | 192 | NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; |
1da177e4 LT |
193 | /* Ensure consistent page alignment of the data. |
194 | * Note: assumes we have exclusive access to this mapping either | |
a656db99 | 195 | * through inode->i_sem or some other mechanism. |
1da177e4 | 196 | */ |
a656db99 TM |
197 | if (page->index == 0) |
198 | invalidate_inode_pages2_range(inode->i_mapping, PAGE_CACHE_SIZE, -1); | |
1da177e4 LT |
199 | unlock_page(page); |
200 | return 0; | |
201 | error: | |
202 | SetPageError(page); | |
203 | unlock_page(page); | |
204 | nfs_zap_caches(inode); | |
205 | desc->error = error; | |
206 | return -EIO; | |
207 | } | |
208 | ||
209 | static inline | |
210 | int dir_decode(nfs_readdir_descriptor_t *desc) | |
211 | { | |
212 | u32 *p = desc->ptr; | |
213 | p = desc->decode(p, desc->entry, desc->plus); | |
214 | if (IS_ERR(p)) | |
215 | return PTR_ERR(p); | |
216 | desc->ptr = p; | |
217 | return 0; | |
218 | } | |
219 | ||
220 | static inline | |
221 | void dir_page_release(nfs_readdir_descriptor_t *desc) | |
222 | { | |
223 | kunmap(desc->page); | |
224 | page_cache_release(desc->page); | |
225 | desc->page = NULL; | |
226 | desc->ptr = NULL; | |
227 | } | |
228 | ||
229 | /* | |
230 | * Given a pointer to a buffer that has already been filled by a call | |
f0dd2136 | 231 | * to readdir, find the next entry with cookie '*desc->dir_cookie'. |
1da177e4 LT |
232 | * |
233 | * If the end of the buffer has been reached, return -EAGAIN, if not, | |
234 | * return the offset within the buffer of the next entry to be | |
235 | * read. | |
236 | */ | |
237 | static inline | |
00a92642 | 238 | int find_dirent(nfs_readdir_descriptor_t *desc) |
1da177e4 LT |
239 | { |
240 | struct nfs_entry *entry = desc->entry; | |
241 | int loop_count = 0, | |
242 | status; | |
243 | ||
244 | while((status = dir_decode(desc)) == 0) { | |
f0dd2136 TM |
245 | dfprintk(VFS, "NFS: found cookie %Lu\n", (unsigned long long)entry->cookie); |
246 | if (entry->prev_cookie == *desc->dir_cookie) | |
1da177e4 LT |
247 | break; |
248 | if (loop_count++ > 200) { | |
249 | loop_count = 0; | |
250 | schedule(); | |
251 | } | |
252 | } | |
253 | dfprintk(VFS, "NFS: find_dirent() returns %d\n", status); | |
254 | return status; | |
255 | } | |
256 | ||
257 | /* | |
00a92642 | 258 | * Given a pointer to a buffer that has already been filled by a call |
f0dd2136 | 259 | * to readdir, find the entry at offset 'desc->file->f_pos'. |
00a92642 OG |
260 | * |
261 | * If the end of the buffer has been reached, return -EAGAIN, if not, | |
262 | * return the offset within the buffer of the next entry to be | |
263 | * read. | |
264 | */ | |
265 | static inline | |
266 | int find_dirent_index(nfs_readdir_descriptor_t *desc) | |
267 | { | |
268 | struct nfs_entry *entry = desc->entry; | |
269 | int loop_count = 0, | |
270 | status; | |
271 | ||
272 | for(;;) { | |
273 | status = dir_decode(desc); | |
274 | if (status) | |
275 | break; | |
276 | ||
f0dd2136 | 277 | dfprintk(VFS, "NFS: found cookie %Lu at index %Ld\n", (unsigned long long)entry->cookie, desc->current_index); |
00a92642 | 278 | |
f0dd2136 TM |
279 | if (desc->file->f_pos == desc->current_index) { |
280 | *desc->dir_cookie = entry->cookie; | |
00a92642 OG |
281 | break; |
282 | } | |
283 | desc->current_index++; | |
284 | if (loop_count++ > 200) { | |
285 | loop_count = 0; | |
286 | schedule(); | |
287 | } | |
288 | } | |
289 | dfprintk(VFS, "NFS: find_dirent_index() returns %d\n", status); | |
290 | return status; | |
291 | } | |
292 | ||
293 | /* | |
294 | * Find the given page, and call find_dirent() or find_dirent_index in | |
295 | * order to try to return the next entry. | |
1da177e4 LT |
296 | */ |
297 | static inline | |
298 | int find_dirent_page(nfs_readdir_descriptor_t *desc) | |
299 | { | |
300 | struct inode *inode = desc->file->f_dentry->d_inode; | |
301 | struct page *page; | |
302 | int status; | |
303 | ||
304 | dfprintk(VFS, "NFS: find_dirent_page() searching directory page %ld\n", desc->page_index); | |
305 | ||
306 | page = read_cache_page(inode->i_mapping, desc->page_index, | |
307 | (filler_t *)nfs_readdir_filler, desc); | |
308 | if (IS_ERR(page)) { | |
309 | status = PTR_ERR(page); | |
310 | goto out; | |
311 | } | |
312 | if (!PageUptodate(page)) | |
313 | goto read_error; | |
314 | ||
315 | /* NOTE: Someone else may have changed the READDIRPLUS flag */ | |
316 | desc->page = page; | |
317 | desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ | |
f0dd2136 | 318 | if (*desc->dir_cookie != 0) |
00a92642 OG |
319 | status = find_dirent(desc); |
320 | else | |
321 | status = find_dirent_index(desc); | |
1da177e4 LT |
322 | if (status < 0) |
323 | dir_page_release(desc); | |
324 | out: | |
325 | dfprintk(VFS, "NFS: find_dirent_page() returns %d\n", status); | |
326 | return status; | |
327 | read_error: | |
328 | page_cache_release(page); | |
329 | return -EIO; | |
330 | } | |
331 | ||
332 | /* | |
333 | * Recurse through the page cache pages, and return a | |
334 | * filled nfs_entry structure of the next directory entry if possible. | |
335 | * | |
f0dd2136 TM |
336 | * The target for the search is '*desc->dir_cookie' if non-0, |
337 | * 'desc->file->f_pos' otherwise | |
1da177e4 LT |
338 | */ |
339 | static inline | |
340 | int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) | |
341 | { | |
342 | int loop_count = 0; | |
343 | int res; | |
344 | ||
00a92642 | 345 | /* Always search-by-index from the beginning of the cache */ |
f0dd2136 TM |
346 | if (*desc->dir_cookie == 0) { |
347 | dfprintk(VFS, "NFS: readdir_search_pagecache() searching for offset %Ld\n", (long long)desc->file->f_pos); | |
00a92642 OG |
348 | desc->page_index = 0; |
349 | desc->entry->cookie = desc->entry->prev_cookie = 0; | |
350 | desc->entry->eof = 0; | |
351 | desc->current_index = 0; | |
f0dd2136 TM |
352 | } else |
353 | dfprintk(VFS, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", (unsigned long long)*desc->dir_cookie); | |
00a92642 | 354 | |
1da177e4 LT |
355 | for (;;) { |
356 | res = find_dirent_page(desc); | |
357 | if (res != -EAGAIN) | |
358 | break; | |
359 | /* Align to beginning of next page */ | |
360 | desc->page_index ++; | |
361 | if (loop_count++ > 200) { | |
362 | loop_count = 0; | |
363 | schedule(); | |
364 | } | |
365 | } | |
366 | dfprintk(VFS, "NFS: readdir_search_pagecache() returned %d\n", res); | |
367 | return res; | |
368 | } | |
369 | ||
370 | static inline unsigned int dt_type(struct inode *inode) | |
371 | { | |
372 | return (inode->i_mode >> 12) & 15; | |
373 | } | |
374 | ||
375 | static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc); | |
376 | ||
377 | /* | |
378 | * Once we've found the start of the dirent within a page: fill 'er up... | |
379 | */ | |
380 | static | |
381 | int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, | |
382 | filldir_t filldir) | |
383 | { | |
384 | struct file *file = desc->file; | |
385 | struct nfs_entry *entry = desc->entry; | |
386 | struct dentry *dentry = NULL; | |
387 | unsigned long fileid; | |
388 | int loop_count = 0, | |
389 | res; | |
390 | ||
00a92642 | 391 | dfprintk(VFS, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n", (long long)entry->cookie); |
1da177e4 LT |
392 | |
393 | for(;;) { | |
394 | unsigned d_type = DT_UNKNOWN; | |
395 | /* Note: entry->prev_cookie contains the cookie for | |
396 | * retrieving the current dirent on the server */ | |
397 | fileid = nfs_fileid_to_ino_t(entry->ino); | |
398 | ||
399 | /* Get a dentry if we have one */ | |
400 | if (dentry != NULL) | |
401 | dput(dentry); | |
402 | dentry = nfs_readdir_lookup(desc); | |
403 | ||
404 | /* Use readdirplus info */ | |
405 | if (dentry != NULL && dentry->d_inode != NULL) { | |
406 | d_type = dt_type(dentry->d_inode); | |
407 | fileid = dentry->d_inode->i_ino; | |
408 | } | |
409 | ||
410 | res = filldir(dirent, entry->name, entry->len, | |
00a92642 | 411 | file->f_pos, fileid, d_type); |
1da177e4 LT |
412 | if (res < 0) |
413 | break; | |
00a92642 | 414 | file->f_pos++; |
f0dd2136 | 415 | *desc->dir_cookie = entry->cookie; |
1da177e4 LT |
416 | if (dir_decode(desc) != 0) { |
417 | desc->page_index ++; | |
418 | break; | |
419 | } | |
420 | if (loop_count++ > 200) { | |
421 | loop_count = 0; | |
422 | schedule(); | |
423 | } | |
424 | } | |
425 | dir_page_release(desc); | |
426 | if (dentry != NULL) | |
427 | dput(dentry); | |
f0dd2136 | 428 | dfprintk(VFS, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", (unsigned long long)*desc->dir_cookie, res); |
1da177e4 LT |
429 | return res; |
430 | } | |
431 | ||
432 | /* | |
433 | * If we cannot find a cookie in our cache, we suspect that this is | |
434 | * because it points to a deleted file, so we ask the server to return | |
435 | * whatever it thinks is the next entry. We then feed this to filldir. | |
436 | * If all goes well, we should then be able to find our way round the | |
437 | * cache on the next call to readdir_search_pagecache(); | |
438 | * | |
439 | * NOTE: we cannot add the anonymous page to the pagecache because | |
440 | * the data it contains might not be page aligned. Besides, | |
441 | * we should already have a complete representation of the | |
442 | * directory in the page cache by the time we get here. | |
443 | */ | |
444 | static inline | |
445 | int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent, | |
446 | filldir_t filldir) | |
447 | { | |
448 | struct file *file = desc->file; | |
449 | struct inode *inode = file->f_dentry->d_inode; | |
450 | struct rpc_cred *cred = nfs_file_cred(file); | |
451 | struct page *page = NULL; | |
452 | int status; | |
453 | ||
f0dd2136 | 454 | dfprintk(VFS, "NFS: uncached_readdir() searching for cookie %Lu\n", (unsigned long long)*desc->dir_cookie); |
1da177e4 LT |
455 | |
456 | page = alloc_page(GFP_HIGHUSER); | |
457 | if (!page) { | |
458 | status = -ENOMEM; | |
459 | goto out; | |
460 | } | |
f0dd2136 | 461 | desc->error = NFS_PROTO(inode)->readdir(file->f_dentry, cred, *desc->dir_cookie, |
1da177e4 LT |
462 | page, |
463 | NFS_SERVER(inode)->dtsize, | |
464 | desc->plus); | |
55296809 | 465 | NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME; |
1da177e4 LT |
466 | desc->page = page; |
467 | desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ | |
468 | if (desc->error >= 0) { | |
469 | if ((status = dir_decode(desc)) == 0) | |
f0dd2136 | 470 | desc->entry->prev_cookie = *desc->dir_cookie; |
1da177e4 LT |
471 | } else |
472 | status = -EIO; | |
473 | if (status < 0) | |
474 | goto out_release; | |
475 | ||
476 | status = nfs_do_filldir(desc, dirent, filldir); | |
477 | ||
478 | /* Reset read descriptor so it searches the page cache from | |
479 | * the start upon the next call to readdir_search_pagecache() */ | |
480 | desc->page_index = 0; | |
481 | desc->entry->cookie = desc->entry->prev_cookie = 0; | |
482 | desc->entry->eof = 0; | |
483 | out: | |
484 | dfprintk(VFS, "NFS: uncached_readdir() returns %d\n", status); | |
485 | return status; | |
486 | out_release: | |
487 | dir_page_release(desc); | |
488 | goto out; | |
489 | } | |
490 | ||
00a92642 OG |
491 | /* The file offset position represents the dirent entry number. A |
492 | last cookie cache takes care of the common case of reading the | |
493 | whole directory. | |
1da177e4 LT |
494 | */ |
495 | static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir) | |
496 | { | |
497 | struct dentry *dentry = filp->f_dentry; | |
498 | struct inode *inode = dentry->d_inode; | |
499 | nfs_readdir_descriptor_t my_desc, | |
500 | *desc = &my_desc; | |
501 | struct nfs_entry my_entry; | |
502 | struct nfs_fh fh; | |
503 | struct nfs_fattr fattr; | |
504 | long res; | |
505 | ||
506 | lock_kernel(); | |
507 | ||
508 | res = nfs_revalidate_inode(NFS_SERVER(inode), inode); | |
509 | if (res < 0) { | |
510 | unlock_kernel(); | |
511 | return res; | |
512 | } | |
513 | ||
514 | /* | |
00a92642 | 515 | * filp->f_pos points to the dirent entry number. |
f0dd2136 | 516 | * *desc->dir_cookie has the cookie for the next entry. We have |
00a92642 OG |
517 | * to either find the entry with the appropriate number or |
518 | * revalidate the cookie. | |
1da177e4 LT |
519 | */ |
520 | memset(desc, 0, sizeof(*desc)); | |
521 | ||
522 | desc->file = filp; | |
f0dd2136 | 523 | desc->dir_cookie = &((struct nfs_open_context *)filp->private_data)->dir_cookie; |
1da177e4 LT |
524 | desc->decode = NFS_PROTO(inode)->decode_dirent; |
525 | desc->plus = NFS_USE_READDIRPLUS(inode); | |
526 | ||
527 | my_entry.cookie = my_entry.prev_cookie = 0; | |
528 | my_entry.eof = 0; | |
529 | my_entry.fh = &fh; | |
530 | my_entry.fattr = &fattr; | |
531 | desc->entry = &my_entry; | |
532 | ||
533 | while(!desc->entry->eof) { | |
534 | res = readdir_search_pagecache(desc); | |
00a92642 | 535 | |
1da177e4 LT |
536 | if (res == -EBADCOOKIE) { |
537 | /* This means either end of directory */ | |
f0dd2136 | 538 | if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) { |
1da177e4 LT |
539 | /* Or that the server has 'lost' a cookie */ |
540 | res = uncached_readdir(desc, dirent, filldir); | |
541 | if (res >= 0) | |
542 | continue; | |
543 | } | |
544 | res = 0; | |
545 | break; | |
546 | } | |
547 | if (res == -ETOOSMALL && desc->plus) { | |
412d582e | 548 | clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); |
1da177e4 LT |
549 | nfs_zap_caches(inode); |
550 | desc->plus = 0; | |
551 | desc->entry->eof = 0; | |
552 | continue; | |
553 | } | |
554 | if (res < 0) | |
555 | break; | |
556 | ||
557 | res = nfs_do_filldir(desc, dirent, filldir); | |
558 | if (res < 0) { | |
559 | res = 0; | |
560 | break; | |
561 | } | |
562 | } | |
563 | unlock_kernel(); | |
564 | if (desc->error < 0) | |
565 | return desc->error; | |
566 | if (res < 0) | |
567 | return res; | |
568 | return 0; | |
569 | } | |
570 | ||
f0dd2136 TM |
571 | loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin) |
572 | { | |
573 | down(&filp->f_dentry->d_inode->i_sem); | |
574 | switch (origin) { | |
575 | case 1: | |
576 | offset += filp->f_pos; | |
577 | case 0: | |
578 | if (offset >= 0) | |
579 | break; | |
580 | default: | |
581 | offset = -EINVAL; | |
582 | goto out; | |
583 | } | |
584 | if (offset != filp->f_pos) { | |
585 | filp->f_pos = offset; | |
586 | ((struct nfs_open_context *)filp->private_data)->dir_cookie = 0; | |
587 | } | |
588 | out: | |
589 | up(&filp->f_dentry->d_inode->i_sem); | |
590 | return offset; | |
591 | } | |
592 | ||
1da177e4 LT |
593 | /* |
594 | * All directory operations under NFS are synchronous, so fsync() | |
595 | * is a dummy operation. | |
596 | */ | |
597 | int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync) | |
598 | { | |
599 | return 0; | |
600 | } | |
601 | ||
602 | /* | |
603 | * A check for whether or not the parent directory has changed. | |
604 | * In the case it has, we assume that the dentries are untrustworthy | |
605 | * and may need to be looked up again. | |
606 | */ | |
607 | static inline int nfs_check_verifier(struct inode *dir, struct dentry *dentry) | |
608 | { | |
609 | if (IS_ROOT(dentry)) | |
610 | return 1; | |
55296809 | 611 | if ((NFS_I(dir)->cache_validity & NFS_INO_INVALID_ATTR) != 0 |
1da177e4 LT |
612 | || nfs_attribute_timeout(dir)) |
613 | return 0; | |
614 | return nfs_verify_change_attribute(dir, (unsigned long)dentry->d_fsdata); | |
615 | } | |
616 | ||
617 | static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf) | |
618 | { | |
619 | dentry->d_fsdata = (void *)verf; | |
620 | } | |
621 | ||
622 | /* | |
623 | * Whenever an NFS operation succeeds, we know that the dentry | |
624 | * is valid, so we update the revalidation timestamp. | |
625 | */ | |
626 | static inline void nfs_renew_times(struct dentry * dentry) | |
627 | { | |
628 | dentry->d_time = jiffies; | |
629 | } | |
630 | ||
1d6757fb TM |
631 | /* |
632 | * Return the intent data that applies to this particular path component | |
633 | * | |
634 | * Note that the current set of intents only apply to the very last | |
635 | * component of the path. | |
636 | * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT. | |
637 | */ | |
638 | static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask) | |
639 | { | |
640 | if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT)) | |
641 | return 0; | |
642 | return nd->flags & mask; | |
643 | } | |
644 | ||
645 | /* | |
646 | * Inode and filehandle revalidation for lookups. | |
647 | * | |
648 | * We force revalidation in the cases where the VFS sets LOOKUP_REVAL, | |
649 | * or if the intent information indicates that we're about to open this | |
650 | * particular file and the "nocto" mount flag is not set. | |
651 | * | |
652 | */ | |
1da177e4 LT |
653 | static inline |
654 | int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd) | |
655 | { | |
656 | struct nfs_server *server = NFS_SERVER(inode); | |
657 | ||
658 | if (nd != NULL) { | |
1da177e4 | 659 | /* VFS wants an on-the-wire revalidation */ |
1d6757fb | 660 | if (nd->flags & LOOKUP_REVAL) |
1da177e4 LT |
661 | goto out_force; |
662 | /* This is an open(2) */ | |
1d6757fb | 663 | if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 && |
1da177e4 LT |
664 | !(server->flags & NFS_MOUNT_NOCTO)) |
665 | goto out_force; | |
666 | } | |
667 | return nfs_revalidate_inode(server, inode); | |
668 | out_force: | |
669 | return __nfs_revalidate_inode(server, inode); | |
670 | } | |
671 | ||
672 | /* | |
673 | * We judge how long we want to trust negative | |
674 | * dentries by looking at the parent inode mtime. | |
675 | * | |
676 | * If parent mtime has changed, we revalidate, else we wait for a | |
677 | * period corresponding to the parent's attribute cache timeout value. | |
678 | */ | |
679 | static inline | |
680 | int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, | |
681 | struct nameidata *nd) | |
682 | { | |
1da177e4 | 683 | /* Don't revalidate a negative dentry if we're creating a new file */ |
1d6757fb | 684 | if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) |
1da177e4 LT |
685 | return 0; |
686 | return !nfs_check_verifier(dir, dentry); | |
687 | } | |
688 | ||
689 | /* | |
690 | * This is called every time the dcache has a lookup hit, | |
691 | * and we should check whether we can really trust that | |
692 | * lookup. | |
693 | * | |
694 | * NOTE! The hit can be a negative hit too, don't assume | |
695 | * we have an inode! | |
696 | * | |
697 | * If the parent directory is seen to have changed, we throw out the | |
698 | * cached dentry and do a new lookup. | |
699 | */ | |
700 | static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd) | |
701 | { | |
702 | struct inode *dir; | |
703 | struct inode *inode; | |
704 | struct dentry *parent; | |
705 | int error; | |
706 | struct nfs_fh fhandle; | |
707 | struct nfs_fattr fattr; | |
708 | unsigned long verifier; | |
709 | ||
710 | parent = dget_parent(dentry); | |
711 | lock_kernel(); | |
712 | dir = parent->d_inode; | |
713 | inode = dentry->d_inode; | |
714 | ||
715 | if (!inode) { | |
716 | if (nfs_neg_need_reval(dir, dentry, nd)) | |
717 | goto out_bad; | |
718 | goto out_valid; | |
719 | } | |
720 | ||
721 | if (is_bad_inode(inode)) { | |
722 | dfprintk(VFS, "nfs_lookup_validate: %s/%s has dud inode\n", | |
723 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
724 | goto out_bad; | |
725 | } | |
726 | ||
727 | /* Revalidate parent directory attribute cache */ | |
728 | if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) | |
729 | goto out_zap_parent; | |
730 | ||
731 | /* Force a full look up iff the parent directory has changed */ | |
732 | if (nfs_check_verifier(dir, dentry)) { | |
733 | if (nfs_lookup_verify_inode(inode, nd)) | |
734 | goto out_zap_parent; | |
735 | goto out_valid; | |
736 | } | |
737 | ||
738 | if (NFS_STALE(inode)) | |
739 | goto out_bad; | |
740 | ||
741 | verifier = nfs_save_change_attribute(dir); | |
742 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr); | |
743 | if (error) | |
744 | goto out_bad; | |
745 | if (nfs_compare_fh(NFS_FH(inode), &fhandle)) | |
746 | goto out_bad; | |
747 | if ((error = nfs_refresh_inode(inode, &fattr)) != 0) | |
748 | goto out_bad; | |
749 | ||
750 | nfs_renew_times(dentry); | |
751 | nfs_set_verifier(dentry, verifier); | |
752 | out_valid: | |
753 | unlock_kernel(); | |
754 | dput(parent); | |
755 | return 1; | |
756 | out_zap_parent: | |
757 | nfs_zap_caches(dir); | |
758 | out_bad: | |
759 | NFS_CACHEINV(dir); | |
760 | if (inode && S_ISDIR(inode->i_mode)) { | |
761 | /* Purge readdir caches. */ | |
762 | nfs_zap_caches(inode); | |
763 | /* If we have submounts, don't unhash ! */ | |
764 | if (have_submounts(dentry)) | |
765 | goto out_valid; | |
766 | shrink_dcache_parent(dentry); | |
767 | } | |
768 | d_drop(dentry); | |
769 | unlock_kernel(); | |
770 | dput(parent); | |
771 | return 0; | |
772 | } | |
773 | ||
774 | /* | |
775 | * This is called from dput() when d_count is going to 0. | |
776 | */ | |
777 | static int nfs_dentry_delete(struct dentry *dentry) | |
778 | { | |
779 | dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", | |
780 | dentry->d_parent->d_name.name, dentry->d_name.name, | |
781 | dentry->d_flags); | |
782 | ||
783 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { | |
784 | /* Unhash it, so that ->d_iput() would be called */ | |
785 | return 1; | |
786 | } | |
787 | if (!(dentry->d_sb->s_flags & MS_ACTIVE)) { | |
788 | /* Unhash it, so that ancestors of killed async unlink | |
789 | * files will be cleaned up during umount */ | |
790 | return 1; | |
791 | } | |
792 | return 0; | |
793 | ||
794 | } | |
795 | ||
796 | /* | |
797 | * Called when the dentry loses inode. | |
798 | * We use it to clean up silly-renamed files. | |
799 | */ | |
800 | static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) | |
801 | { | |
802 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { | |
803 | lock_kernel(); | |
804 | inode->i_nlink--; | |
805 | nfs_complete_unlink(dentry); | |
806 | unlock_kernel(); | |
807 | } | |
808 | /* When creating a negative dentry, we want to renew d_time */ | |
809 | nfs_renew_times(dentry); | |
810 | iput(inode); | |
811 | } | |
812 | ||
813 | struct dentry_operations nfs_dentry_operations = { | |
814 | .d_revalidate = nfs_lookup_revalidate, | |
815 | .d_delete = nfs_dentry_delete, | |
816 | .d_iput = nfs_dentry_iput, | |
817 | }; | |
818 | ||
1d6757fb TM |
819 | /* |
820 | * Use intent information to check whether or not we're going to do | |
821 | * an O_EXCL create using this path component. | |
822 | */ | |
1da177e4 LT |
823 | static inline |
824 | int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd) | |
825 | { | |
826 | if (NFS_PROTO(dir)->version == 2) | |
827 | return 0; | |
1d6757fb | 828 | if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_CREATE) == 0) |
1da177e4 LT |
829 | return 0; |
830 | return (nd->intent.open.flags & O_EXCL) != 0; | |
831 | } | |
832 | ||
833 | static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) | |
834 | { | |
835 | struct dentry *res; | |
836 | struct inode *inode = NULL; | |
837 | int error; | |
838 | struct nfs_fh fhandle; | |
839 | struct nfs_fattr fattr; | |
840 | ||
841 | dfprintk(VFS, "NFS: lookup(%s/%s)\n", | |
842 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
843 | ||
844 | res = ERR_PTR(-ENAMETOOLONG); | |
845 | if (dentry->d_name.len > NFS_SERVER(dir)->namelen) | |
846 | goto out; | |
847 | ||
848 | res = ERR_PTR(-ENOMEM); | |
849 | dentry->d_op = NFS_PROTO(dir)->dentry_ops; | |
850 | ||
851 | lock_kernel(); | |
852 | /* Revalidate parent directory attribute cache */ | |
853 | error = nfs_revalidate_inode(NFS_SERVER(dir), dir); | |
854 | if (error < 0) { | |
855 | res = ERR_PTR(error); | |
856 | goto out_unlock; | |
857 | } | |
858 | ||
859 | /* If we're doing an exclusive create, optimize away the lookup */ | |
860 | if (nfs_is_exclusive_create(dir, nd)) | |
861 | goto no_entry; | |
862 | ||
863 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr); | |
864 | if (error == -ENOENT) | |
865 | goto no_entry; | |
866 | if (error < 0) { | |
867 | res = ERR_PTR(error); | |
868 | goto out_unlock; | |
869 | } | |
870 | res = ERR_PTR(-EACCES); | |
871 | inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr); | |
872 | if (!inode) | |
873 | goto out_unlock; | |
874 | no_entry: | |
875 | res = d_add_unique(dentry, inode); | |
876 | if (res != NULL) | |
877 | dentry = res; | |
878 | nfs_renew_times(dentry); | |
879 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
880 | out_unlock: | |
881 | unlock_kernel(); | |
882 | out: | |
883 | return res; | |
884 | } | |
885 | ||
886 | #ifdef CONFIG_NFS_V4 | |
887 | static int nfs_open_revalidate(struct dentry *, struct nameidata *); | |
888 | ||
889 | struct dentry_operations nfs4_dentry_operations = { | |
890 | .d_revalidate = nfs_open_revalidate, | |
891 | .d_delete = nfs_dentry_delete, | |
892 | .d_iput = nfs_dentry_iput, | |
893 | }; | |
894 | ||
1d6757fb TM |
895 | /* |
896 | * Use intent information to determine whether we need to substitute | |
897 | * the NFSv4-style stateful OPEN for the LOOKUP call | |
898 | */ | |
1da177e4 LT |
899 | static int is_atomic_open(struct inode *dir, struct nameidata *nd) |
900 | { | |
1d6757fb | 901 | if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0) |
1da177e4 LT |
902 | return 0; |
903 | /* NFS does not (yet) have a stateful open for directories */ | |
904 | if (nd->flags & LOOKUP_DIRECTORY) | |
905 | return 0; | |
906 | /* Are we trying to write to a read only partition? */ | |
907 | if (IS_RDONLY(dir) && (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE))) | |
908 | return 0; | |
909 | return 1; | |
910 | } | |
911 | ||
912 | static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) | |
913 | { | |
914 | struct dentry *res = NULL; | |
915 | struct inode *inode = NULL; | |
916 | int error; | |
917 | ||
918 | /* Check that we are indeed trying to open this file */ | |
919 | if (!is_atomic_open(dir, nd)) | |
920 | goto no_open; | |
921 | ||
922 | if (dentry->d_name.len > NFS_SERVER(dir)->namelen) { | |
923 | res = ERR_PTR(-ENAMETOOLONG); | |
924 | goto out; | |
925 | } | |
926 | dentry->d_op = NFS_PROTO(dir)->dentry_ops; | |
927 | ||
928 | /* Let vfs_create() deal with O_EXCL */ | |
929 | if (nd->intent.open.flags & O_EXCL) | |
930 | goto no_entry; | |
931 | ||
932 | /* Open the file on the server */ | |
933 | lock_kernel(); | |
934 | /* Revalidate parent directory attribute cache */ | |
935 | error = nfs_revalidate_inode(NFS_SERVER(dir), dir); | |
936 | if (error < 0) { | |
937 | res = ERR_PTR(error); | |
938 | goto out; | |
939 | } | |
940 | ||
941 | if (nd->intent.open.flags & O_CREAT) { | |
942 | nfs_begin_data_update(dir); | |
943 | inode = nfs4_atomic_open(dir, dentry, nd); | |
944 | nfs_end_data_update(dir); | |
945 | } else | |
946 | inode = nfs4_atomic_open(dir, dentry, nd); | |
947 | unlock_kernel(); | |
948 | if (IS_ERR(inode)) { | |
949 | error = PTR_ERR(inode); | |
950 | switch (error) { | |
951 | /* Make a negative dentry */ | |
952 | case -ENOENT: | |
953 | inode = NULL; | |
954 | break; | |
955 | /* This turned out not to be a regular file */ | |
956 | case -ELOOP: | |
957 | if (!(nd->intent.open.flags & O_NOFOLLOW)) | |
958 | goto no_open; | |
959 | /* case -EISDIR: */ | |
960 | /* case -EINVAL: */ | |
961 | default: | |
962 | res = ERR_PTR(error); | |
963 | goto out; | |
964 | } | |
965 | } | |
966 | no_entry: | |
967 | res = d_add_unique(dentry, inode); | |
968 | if (res != NULL) | |
969 | dentry = res; | |
970 | nfs_renew_times(dentry); | |
971 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
972 | out: | |
973 | return res; | |
974 | no_open: | |
975 | return nfs_lookup(dir, dentry, nd); | |
976 | } | |
977 | ||
978 | static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) | |
979 | { | |
980 | struct dentry *parent = NULL; | |
981 | struct inode *inode = dentry->d_inode; | |
982 | struct inode *dir; | |
983 | unsigned long verifier; | |
984 | int openflags, ret = 0; | |
985 | ||
986 | parent = dget_parent(dentry); | |
987 | dir = parent->d_inode; | |
988 | if (!is_atomic_open(dir, nd)) | |
989 | goto no_open; | |
990 | /* We can't create new files in nfs_open_revalidate(), so we | |
991 | * optimize away revalidation of negative dentries. | |
992 | */ | |
993 | if (inode == NULL) | |
994 | goto out; | |
995 | /* NFS only supports OPEN on regular files */ | |
996 | if (!S_ISREG(inode->i_mode)) | |
997 | goto no_open; | |
998 | openflags = nd->intent.open.flags; | |
999 | /* We cannot do exclusive creation on a positive dentry */ | |
1000 | if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) | |
1001 | goto no_open; | |
1002 | /* We can't create new files, or truncate existing ones here */ | |
1003 | openflags &= ~(O_CREAT|O_TRUNC); | |
1004 | ||
1005 | /* | |
1006 | * Note: we're not holding inode->i_sem and so may be racing with | |
1007 | * operations that change the directory. We therefore save the | |
1008 | * change attribute *before* we do the RPC call. | |
1009 | */ | |
1010 | lock_kernel(); | |
1011 | verifier = nfs_save_change_attribute(dir); | |
1012 | ret = nfs4_open_revalidate(dir, dentry, openflags); | |
1013 | if (!ret) | |
1014 | nfs_set_verifier(dentry, verifier); | |
1015 | unlock_kernel(); | |
1016 | out: | |
1017 | dput(parent); | |
1018 | if (!ret) | |
1019 | d_drop(dentry); | |
1020 | return ret; | |
1021 | no_open: | |
1022 | dput(parent); | |
1023 | if (inode != NULL && nfs_have_delegation(inode, FMODE_READ)) | |
1024 | return 1; | |
1025 | return nfs_lookup_revalidate(dentry, nd); | |
1026 | } | |
1027 | #endif /* CONFIG_NFSV4 */ | |
1028 | ||
1029 | static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc) | |
1030 | { | |
1031 | struct dentry *parent = desc->file->f_dentry; | |
1032 | struct inode *dir = parent->d_inode; | |
1033 | struct nfs_entry *entry = desc->entry; | |
1034 | struct dentry *dentry, *alias; | |
1035 | struct qstr name = { | |
1036 | .name = entry->name, | |
1037 | .len = entry->len, | |
1038 | }; | |
1039 | struct inode *inode; | |
1040 | ||
1041 | switch (name.len) { | |
1042 | case 2: | |
1043 | if (name.name[0] == '.' && name.name[1] == '.') | |
1044 | return dget_parent(parent); | |
1045 | break; | |
1046 | case 1: | |
1047 | if (name.name[0] == '.') | |
1048 | return dget(parent); | |
1049 | } | |
1050 | name.hash = full_name_hash(name.name, name.len); | |
1051 | dentry = d_lookup(parent, &name); | |
1052 | if (dentry != NULL) | |
1053 | return dentry; | |
1054 | if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR)) | |
1055 | return NULL; | |
1056 | /* Note: caller is already holding the dir->i_sem! */ | |
1057 | dentry = d_alloc(parent, &name); | |
1058 | if (dentry == NULL) | |
1059 | return NULL; | |
1060 | dentry->d_op = NFS_PROTO(dir)->dentry_ops; | |
1061 | inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); | |
1062 | if (!inode) { | |
1063 | dput(dentry); | |
1064 | return NULL; | |
1065 | } | |
1066 | alias = d_add_unique(dentry, inode); | |
1067 | if (alias != NULL) { | |
1068 | dput(dentry); | |
1069 | dentry = alias; | |
1070 | } | |
1071 | nfs_renew_times(dentry); | |
1072 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1073 | return dentry; | |
1074 | } | |
1075 | ||
1076 | /* | |
1077 | * Code common to create, mkdir, and mknod. | |
1078 | */ | |
1079 | int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, | |
1080 | struct nfs_fattr *fattr) | |
1081 | { | |
1082 | struct inode *inode; | |
1083 | int error = -EACCES; | |
1084 | ||
1085 | /* We may have been initialized further down */ | |
1086 | if (dentry->d_inode) | |
1087 | return 0; | |
1088 | if (fhandle->size == 0) { | |
1089 | struct inode *dir = dentry->d_parent->d_inode; | |
1090 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr); | |
1091 | if (error) | |
1092 | goto out_err; | |
1093 | } | |
1094 | if (!(fattr->valid & NFS_ATTR_FATTR)) { | |
1095 | struct nfs_server *server = NFS_SB(dentry->d_sb); | |
1096 | error = server->rpc_ops->getattr(server, fhandle, fattr); | |
1097 | if (error < 0) | |
1098 | goto out_err; | |
1099 | } | |
1100 | error = -ENOMEM; | |
1101 | inode = nfs_fhget(dentry->d_sb, fhandle, fattr); | |
1102 | if (inode == NULL) | |
1103 | goto out_err; | |
1104 | d_instantiate(dentry, inode); | |
1105 | return 0; | |
1106 | out_err: | |
1107 | d_drop(dentry); | |
1108 | return error; | |
1109 | } | |
1110 | ||
1111 | /* | |
1112 | * Following a failed create operation, we drop the dentry rather | |
1113 | * than retain a negative dentry. This avoids a problem in the event | |
1114 | * that the operation succeeded on the server, but an error in the | |
1115 | * reply path made it appear to have failed. | |
1116 | */ | |
1117 | static int nfs_create(struct inode *dir, struct dentry *dentry, int mode, | |
1118 | struct nameidata *nd) | |
1119 | { | |
1120 | struct iattr attr; | |
1121 | int error; | |
1122 | int open_flags = 0; | |
1123 | ||
1124 | dfprintk(VFS, "NFS: create(%s/%ld, %s\n", dir->i_sb->s_id, | |
1125 | dir->i_ino, dentry->d_name.name); | |
1126 | ||
1127 | attr.ia_mode = mode; | |
1128 | attr.ia_valid = ATTR_MODE; | |
1129 | ||
1130 | if (nd && (nd->flags & LOOKUP_CREATE)) | |
1131 | open_flags = nd->intent.open.flags; | |
1132 | ||
1133 | lock_kernel(); | |
1134 | nfs_begin_data_update(dir); | |
1135 | error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags); | |
1136 | nfs_end_data_update(dir); | |
1137 | if (error != 0) | |
1138 | goto out_err; | |
1139 | nfs_renew_times(dentry); | |
1140 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1141 | unlock_kernel(); | |
1142 | return 0; | |
1143 | out_err: | |
1144 | unlock_kernel(); | |
1145 | d_drop(dentry); | |
1146 | return error; | |
1147 | } | |
1148 | ||
1149 | /* | |
1150 | * See comments for nfs_proc_create regarding failed operations. | |
1151 | */ | |
1152 | static int | |
1153 | nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev) | |
1154 | { | |
1155 | struct iattr attr; | |
1156 | int status; | |
1157 | ||
1158 | dfprintk(VFS, "NFS: mknod(%s/%ld, %s\n", dir->i_sb->s_id, | |
1159 | dir->i_ino, dentry->d_name.name); | |
1160 | ||
1161 | if (!new_valid_dev(rdev)) | |
1162 | return -EINVAL; | |
1163 | ||
1164 | attr.ia_mode = mode; | |
1165 | attr.ia_valid = ATTR_MODE; | |
1166 | ||
1167 | lock_kernel(); | |
1168 | nfs_begin_data_update(dir); | |
1169 | status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); | |
1170 | nfs_end_data_update(dir); | |
1171 | if (status != 0) | |
1172 | goto out_err; | |
1173 | nfs_renew_times(dentry); | |
1174 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1175 | unlock_kernel(); | |
1176 | return 0; | |
1177 | out_err: | |
1178 | unlock_kernel(); | |
1179 | d_drop(dentry); | |
1180 | return status; | |
1181 | } | |
1182 | ||
1183 | /* | |
1184 | * See comments for nfs_proc_create regarding failed operations. | |
1185 | */ | |
1186 | static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) | |
1187 | { | |
1188 | struct iattr attr; | |
1189 | int error; | |
1190 | ||
1191 | dfprintk(VFS, "NFS: mkdir(%s/%ld, %s\n", dir->i_sb->s_id, | |
1192 | dir->i_ino, dentry->d_name.name); | |
1193 | ||
1194 | attr.ia_valid = ATTR_MODE; | |
1195 | attr.ia_mode = mode | S_IFDIR; | |
1196 | ||
1197 | lock_kernel(); | |
1198 | nfs_begin_data_update(dir); | |
1199 | error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); | |
1200 | nfs_end_data_update(dir); | |
1201 | if (error != 0) | |
1202 | goto out_err; | |
1203 | nfs_renew_times(dentry); | |
1204 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1205 | unlock_kernel(); | |
1206 | return 0; | |
1207 | out_err: | |
1208 | d_drop(dentry); | |
1209 | unlock_kernel(); | |
1210 | return error; | |
1211 | } | |
1212 | ||
1213 | static int nfs_rmdir(struct inode *dir, struct dentry *dentry) | |
1214 | { | |
1215 | int error; | |
1216 | ||
1217 | dfprintk(VFS, "NFS: rmdir(%s/%ld, %s\n", dir->i_sb->s_id, | |
1218 | dir->i_ino, dentry->d_name.name); | |
1219 | ||
1220 | lock_kernel(); | |
1221 | nfs_begin_data_update(dir); | |
1222 | error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); | |
1223 | /* Ensure the VFS deletes this inode */ | |
1224 | if (error == 0 && dentry->d_inode != NULL) | |
1225 | dentry->d_inode->i_nlink = 0; | |
1226 | nfs_end_data_update(dir); | |
1227 | unlock_kernel(); | |
1228 | ||
1229 | return error; | |
1230 | } | |
1231 | ||
1232 | static int nfs_sillyrename(struct inode *dir, struct dentry *dentry) | |
1233 | { | |
1234 | static unsigned int sillycounter; | |
1235 | const int i_inosize = sizeof(dir->i_ino)*2; | |
1236 | const int countersize = sizeof(sillycounter)*2; | |
1237 | const int slen = sizeof(".nfs") + i_inosize + countersize - 1; | |
1238 | char silly[slen+1]; | |
1239 | struct qstr qsilly; | |
1240 | struct dentry *sdentry; | |
1241 | int error = -EIO; | |
1242 | ||
1243 | dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n", | |
1244 | dentry->d_parent->d_name.name, dentry->d_name.name, | |
1245 | atomic_read(&dentry->d_count)); | |
1246 | ||
1247 | #ifdef NFS_PARANOIA | |
1248 | if (!dentry->d_inode) | |
1249 | printk("NFS: silly-renaming %s/%s, negative dentry??\n", | |
1250 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
1251 | #endif | |
1252 | /* | |
1253 | * We don't allow a dentry to be silly-renamed twice. | |
1254 | */ | |
1255 | error = -EBUSY; | |
1256 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) | |
1257 | goto out; | |
1258 | ||
1259 | sprintf(silly, ".nfs%*.*lx", | |
1260 | i_inosize, i_inosize, dentry->d_inode->i_ino); | |
1261 | ||
1262 | sdentry = NULL; | |
1263 | do { | |
1264 | char *suffix = silly + slen - countersize; | |
1265 | ||
1266 | dput(sdentry); | |
1267 | sillycounter++; | |
1268 | sprintf(suffix, "%*.*x", countersize, countersize, sillycounter); | |
1269 | ||
1270 | dfprintk(VFS, "trying to rename %s to %s\n", | |
1271 | dentry->d_name.name, silly); | |
1272 | ||
1273 | sdentry = lookup_one_len(silly, dentry->d_parent, slen); | |
1274 | /* | |
1275 | * N.B. Better to return EBUSY here ... it could be | |
1276 | * dangerous to delete the file while it's in use. | |
1277 | */ | |
1278 | if (IS_ERR(sdentry)) | |
1279 | goto out; | |
1280 | } while(sdentry->d_inode != NULL); /* need negative lookup */ | |
1281 | ||
1282 | qsilly.name = silly; | |
1283 | qsilly.len = strlen(silly); | |
1284 | nfs_begin_data_update(dir); | |
1285 | if (dentry->d_inode) { | |
1286 | nfs_begin_data_update(dentry->d_inode); | |
1287 | error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, | |
1288 | dir, &qsilly); | |
1289 | nfs_end_data_update(dentry->d_inode); | |
1290 | } else | |
1291 | error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, | |
1292 | dir, &qsilly); | |
1293 | nfs_end_data_update(dir); | |
1294 | if (!error) { | |
1295 | nfs_renew_times(dentry); | |
1296 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1297 | d_move(dentry, sdentry); | |
1298 | error = nfs_async_unlink(dentry); | |
1299 | /* If we return 0 we don't unlink */ | |
1300 | } | |
1301 | dput(sdentry); | |
1302 | out: | |
1303 | return error; | |
1304 | } | |
1305 | ||
1306 | /* | |
1307 | * Remove a file after making sure there are no pending writes, | |
1308 | * and after checking that the file has only one user. | |
1309 | * | |
1310 | * We invalidate the attribute cache and free the inode prior to the operation | |
1311 | * to avoid possible races if the server reuses the inode. | |
1312 | */ | |
1313 | static int nfs_safe_remove(struct dentry *dentry) | |
1314 | { | |
1315 | struct inode *dir = dentry->d_parent->d_inode; | |
1316 | struct inode *inode = dentry->d_inode; | |
1317 | int error = -EBUSY; | |
1318 | ||
1319 | dfprintk(VFS, "NFS: safe_remove(%s/%s)\n", | |
1320 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
1321 | ||
1322 | /* If the dentry was sillyrenamed, we simply call d_delete() */ | |
1323 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { | |
1324 | error = 0; | |
1325 | goto out; | |
1326 | } | |
1327 | ||
1328 | nfs_begin_data_update(dir); | |
1329 | if (inode != NULL) { | |
1330 | nfs_begin_data_update(inode); | |
1331 | error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); | |
1332 | /* The VFS may want to delete this inode */ | |
1333 | if (error == 0) | |
1334 | inode->i_nlink--; | |
1335 | nfs_end_data_update(inode); | |
1336 | } else | |
1337 | error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); | |
1338 | nfs_end_data_update(dir); | |
1339 | out: | |
1340 | return error; | |
1341 | } | |
1342 | ||
1343 | /* We do silly rename. In case sillyrename() returns -EBUSY, the inode | |
1344 | * belongs to an active ".nfs..." file and we return -EBUSY. | |
1345 | * | |
1346 | * If sillyrename() returns 0, we do nothing, otherwise we unlink. | |
1347 | */ | |
1348 | static int nfs_unlink(struct inode *dir, struct dentry *dentry) | |
1349 | { | |
1350 | int error; | |
1351 | int need_rehash = 0; | |
1352 | ||
1353 | dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, | |
1354 | dir->i_ino, dentry->d_name.name); | |
1355 | ||
1356 | lock_kernel(); | |
1357 | spin_lock(&dcache_lock); | |
1358 | spin_lock(&dentry->d_lock); | |
1359 | if (atomic_read(&dentry->d_count) > 1) { | |
1360 | spin_unlock(&dentry->d_lock); | |
1361 | spin_unlock(&dcache_lock); | |
1362 | error = nfs_sillyrename(dir, dentry); | |
1363 | unlock_kernel(); | |
1364 | return error; | |
1365 | } | |
1366 | if (!d_unhashed(dentry)) { | |
1367 | __d_drop(dentry); | |
1368 | need_rehash = 1; | |
1369 | } | |
1370 | spin_unlock(&dentry->d_lock); | |
1371 | spin_unlock(&dcache_lock); | |
1372 | error = nfs_safe_remove(dentry); | |
1373 | if (!error) { | |
1374 | nfs_renew_times(dentry); | |
1375 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1376 | } else if (need_rehash) | |
1377 | d_rehash(dentry); | |
1378 | unlock_kernel(); | |
1379 | return error; | |
1380 | } | |
1381 | ||
1382 | static int | |
1383 | nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) | |
1384 | { | |
1385 | struct iattr attr; | |
1386 | struct nfs_fattr sym_attr; | |
1387 | struct nfs_fh sym_fh; | |
1388 | struct qstr qsymname; | |
1389 | int error; | |
1390 | ||
1391 | dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id, | |
1392 | dir->i_ino, dentry->d_name.name, symname); | |
1393 | ||
1394 | #ifdef NFS_PARANOIA | |
1395 | if (dentry->d_inode) | |
1396 | printk("nfs_proc_symlink: %s/%s not negative!\n", | |
1397 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
1398 | #endif | |
1399 | /* | |
1400 | * Fill in the sattr for the call. | |
1401 | * Note: SunOS 4.1.2 crashes if the mode isn't initialized! | |
1402 | */ | |
1403 | attr.ia_valid = ATTR_MODE; | |
1404 | attr.ia_mode = S_IFLNK | S_IRWXUGO; | |
1405 | ||
1406 | qsymname.name = symname; | |
1407 | qsymname.len = strlen(symname); | |
1408 | ||
1409 | lock_kernel(); | |
1410 | nfs_begin_data_update(dir); | |
1411 | error = NFS_PROTO(dir)->symlink(dir, &dentry->d_name, &qsymname, | |
1412 | &attr, &sym_fh, &sym_attr); | |
1413 | nfs_end_data_update(dir); | |
1414 | if (!error) { | |
1415 | error = nfs_instantiate(dentry, &sym_fh, &sym_attr); | |
1416 | } else { | |
1417 | if (error == -EEXIST) | |
1418 | printk("nfs_proc_symlink: %s/%s already exists??\n", | |
1419 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
1420 | d_drop(dentry); | |
1421 | } | |
1422 | unlock_kernel(); | |
1423 | return error; | |
1424 | } | |
1425 | ||
1426 | static int | |
1427 | nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) | |
1428 | { | |
1429 | struct inode *inode = old_dentry->d_inode; | |
1430 | int error; | |
1431 | ||
1432 | dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n", | |
1433 | old_dentry->d_parent->d_name.name, old_dentry->d_name.name, | |
1434 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
1435 | ||
1436 | /* | |
1437 | * Drop the dentry in advance to force a new lookup. | |
1438 | * Since nfs_proc_link doesn't return a file handle, | |
1439 | * we can't use the existing dentry. | |
1440 | */ | |
1441 | lock_kernel(); | |
1442 | d_drop(dentry); | |
1443 | ||
1444 | nfs_begin_data_update(dir); | |
1445 | nfs_begin_data_update(inode); | |
1446 | error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); | |
1447 | nfs_end_data_update(inode); | |
1448 | nfs_end_data_update(dir); | |
1449 | unlock_kernel(); | |
1450 | return error; | |
1451 | } | |
1452 | ||
1453 | /* | |
1454 | * RENAME | |
1455 | * FIXME: Some nfsds, like the Linux user space nfsd, may generate a | |
1456 | * different file handle for the same inode after a rename (e.g. when | |
1457 | * moving to a different directory). A fail-safe method to do so would | |
1458 | * be to look up old_dir/old_name, create a link to new_dir/new_name and | |
1459 | * rename the old file using the sillyrename stuff. This way, the original | |
1460 | * file in old_dir will go away when the last process iput()s the inode. | |
1461 | * | |
1462 | * FIXED. | |
1463 | * | |
1464 | * It actually works quite well. One needs to have the possibility for | |
1465 | * at least one ".nfs..." file in each directory the file ever gets | |
1466 | * moved or linked to which happens automagically with the new | |
1467 | * implementation that only depends on the dcache stuff instead of | |
1468 | * using the inode layer | |
1469 | * | |
1470 | * Unfortunately, things are a little more complicated than indicated | |
1471 | * above. For a cross-directory move, we want to make sure we can get | |
1472 | * rid of the old inode after the operation. This means there must be | |
1473 | * no pending writes (if it's a file), and the use count must be 1. | |
1474 | * If these conditions are met, we can drop the dentries before doing | |
1475 | * the rename. | |
1476 | */ | |
1477 | static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, | |
1478 | struct inode *new_dir, struct dentry *new_dentry) | |
1479 | { | |
1480 | struct inode *old_inode = old_dentry->d_inode; | |
1481 | struct inode *new_inode = new_dentry->d_inode; | |
1482 | struct dentry *dentry = NULL, *rehash = NULL; | |
1483 | int error = -EBUSY; | |
1484 | ||
1485 | /* | |
1486 | * To prevent any new references to the target during the rename, | |
1487 | * we unhash the dentry and free the inode in advance. | |
1488 | */ | |
1489 | lock_kernel(); | |
1490 | if (!d_unhashed(new_dentry)) { | |
1491 | d_drop(new_dentry); | |
1492 | rehash = new_dentry; | |
1493 | } | |
1494 | ||
1495 | dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", | |
1496 | old_dentry->d_parent->d_name.name, old_dentry->d_name.name, | |
1497 | new_dentry->d_parent->d_name.name, new_dentry->d_name.name, | |
1498 | atomic_read(&new_dentry->d_count)); | |
1499 | ||
1500 | /* | |
1501 | * First check whether the target is busy ... we can't | |
1502 | * safely do _any_ rename if the target is in use. | |
1503 | * | |
1504 | * For files, make a copy of the dentry and then do a | |
1505 | * silly-rename. If the silly-rename succeeds, the | |
1506 | * copied dentry is hashed and becomes the new target. | |
1507 | */ | |
1508 | if (!new_inode) | |
1509 | goto go_ahead; | |
1510 | if (S_ISDIR(new_inode->i_mode)) | |
1511 | goto out; | |
1512 | else if (atomic_read(&new_dentry->d_count) > 2) { | |
1513 | int err; | |
1514 | /* copy the target dentry's name */ | |
1515 | dentry = d_alloc(new_dentry->d_parent, | |
1516 | &new_dentry->d_name); | |
1517 | if (!dentry) | |
1518 | goto out; | |
1519 | ||
1520 | /* silly-rename the existing target ... */ | |
1521 | err = nfs_sillyrename(new_dir, new_dentry); | |
1522 | if (!err) { | |
1523 | new_dentry = rehash = dentry; | |
1524 | new_inode = NULL; | |
1525 | /* instantiate the replacement target */ | |
1526 | d_instantiate(new_dentry, NULL); | |
1527 | } else if (atomic_read(&new_dentry->d_count) > 1) { | |
1528 | /* dentry still busy? */ | |
1529 | #ifdef NFS_PARANOIA | |
1530 | printk("nfs_rename: target %s/%s busy, d_count=%d\n", | |
1531 | new_dentry->d_parent->d_name.name, | |
1532 | new_dentry->d_name.name, | |
1533 | atomic_read(&new_dentry->d_count)); | |
1534 | #endif | |
1535 | goto out; | |
1536 | } | |
1537 | } | |
1538 | ||
1539 | go_ahead: | |
1540 | /* | |
1541 | * ... prune child dentries and writebacks if needed. | |
1542 | */ | |
1543 | if (atomic_read(&old_dentry->d_count) > 1) { | |
1544 | nfs_wb_all(old_inode); | |
1545 | shrink_dcache_parent(old_dentry); | |
1546 | } | |
1547 | ||
1548 | if (new_inode) | |
1549 | d_delete(new_dentry); | |
1550 | ||
1551 | nfs_begin_data_update(old_dir); | |
1552 | nfs_begin_data_update(new_dir); | |
1553 | nfs_begin_data_update(old_inode); | |
1554 | error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name, | |
1555 | new_dir, &new_dentry->d_name); | |
1556 | nfs_end_data_update(old_inode); | |
1557 | nfs_end_data_update(new_dir); | |
1558 | nfs_end_data_update(old_dir); | |
1559 | out: | |
1560 | if (rehash) | |
1561 | d_rehash(rehash); | |
1562 | if (!error) { | |
1563 | if (!S_ISDIR(old_inode->i_mode)) | |
1564 | d_move(old_dentry, new_dentry); | |
1565 | nfs_renew_times(new_dentry); | |
1566 | nfs_set_verifier(new_dentry, nfs_save_change_attribute(new_dir)); | |
1567 | } | |
1568 | ||
1569 | /* new dentry created? */ | |
1570 | if (dentry) | |
1571 | dput(dentry); | |
1572 | unlock_kernel(); | |
1573 | return error; | |
1574 | } | |
1575 | ||
1576 | int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) | |
1577 | { | |
55296809 CL |
1578 | struct nfs_inode *nfsi = NFS_I(inode); |
1579 | struct nfs_access_entry *cache = &nfsi->cache_access; | |
1da177e4 LT |
1580 | |
1581 | if (cache->cred != cred | |
1582 | || time_after(jiffies, cache->jiffies + NFS_ATTRTIMEO(inode)) | |
55296809 | 1583 | || (nfsi->cache_validity & NFS_INO_INVALID_ACCESS)) |
1da177e4 LT |
1584 | return -ENOENT; |
1585 | memcpy(res, cache, sizeof(*res)); | |
1586 | return 0; | |
1587 | } | |
1588 | ||
1589 | void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) | |
1590 | { | |
55296809 CL |
1591 | struct nfs_inode *nfsi = NFS_I(inode); |
1592 | struct nfs_access_entry *cache = &nfsi->cache_access; | |
1da177e4 LT |
1593 | |
1594 | if (cache->cred != set->cred) { | |
1595 | if (cache->cred) | |
1596 | put_rpccred(cache->cred); | |
1597 | cache->cred = get_rpccred(set->cred); | |
1598 | } | |
55296809 | 1599 | nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; |
1da177e4 LT |
1600 | cache->jiffies = set->jiffies; |
1601 | cache->mask = set->mask; | |
1602 | } | |
1603 | ||
1604 | static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) | |
1605 | { | |
1606 | struct nfs_access_entry cache; | |
1607 | int status; | |
1608 | ||
1609 | status = nfs_access_get_cached(inode, cred, &cache); | |
1610 | if (status == 0) | |
1611 | goto out; | |
1612 | ||
1613 | /* Be clever: ask server to check for all possible rights */ | |
1614 | cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; | |
1615 | cache.cred = cred; | |
1616 | cache.jiffies = jiffies; | |
1617 | status = NFS_PROTO(inode)->access(inode, &cache); | |
1618 | if (status != 0) | |
1619 | return status; | |
1620 | nfs_access_add_cache(inode, &cache); | |
1621 | out: | |
1622 | if ((cache.mask & mask) == mask) | |
1623 | return 0; | |
1624 | return -EACCES; | |
1625 | } | |
1626 | ||
1627 | int nfs_permission(struct inode *inode, int mask, struct nameidata *nd) | |
1628 | { | |
1629 | struct rpc_cred *cred; | |
1630 | int res = 0; | |
1631 | ||
1632 | if (mask == 0) | |
1633 | goto out; | |
1634 | /* Is this sys_access() ? */ | |
1635 | if (nd != NULL && (nd->flags & LOOKUP_ACCESS)) | |
1636 | goto force_lookup; | |
1637 | ||
1638 | switch (inode->i_mode & S_IFMT) { | |
1639 | case S_IFLNK: | |
1640 | goto out; | |
1641 | case S_IFREG: | |
1642 | /* NFSv4 has atomic_open... */ | |
1643 | if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) | |
1644 | && nd != NULL | |
1645 | && (nd->flags & LOOKUP_OPEN)) | |
1646 | goto out; | |
1647 | break; | |
1648 | case S_IFDIR: | |
1649 | /* | |
1650 | * Optimize away all write operations, since the server | |
1651 | * will check permissions when we perform the op. | |
1652 | */ | |
1653 | if ((mask & MAY_WRITE) && !(mask & MAY_READ)) | |
1654 | goto out; | |
1655 | } | |
1656 | ||
1657 | force_lookup: | |
1658 | lock_kernel(); | |
1659 | ||
1660 | if (!NFS_PROTO(inode)->access) | |
1661 | goto out_notsup; | |
1662 | ||
1663 | cred = rpcauth_lookupcred(NFS_CLIENT(inode)->cl_auth, 0); | |
1664 | if (!IS_ERR(cred)) { | |
1665 | res = nfs_do_access(inode, cred, mask); | |
1666 | put_rpccred(cred); | |
1667 | } else | |
1668 | res = PTR_ERR(cred); | |
1669 | unlock_kernel(); | |
1670 | out: | |
1671 | return res; | |
1672 | out_notsup: | |
1673 | res = nfs_revalidate_inode(NFS_SERVER(inode), inode); | |
1674 | if (res == 0) | |
1675 | res = generic_permission(inode, mask, NULL); | |
1676 | unlock_kernel(); | |
1677 | return res; | |
1678 | } | |
1679 | ||
1680 | /* | |
1681 | * Local variables: | |
1682 | * version-control: t | |
1683 | * kept-new-versions: 5 | |
1684 | * End: | |
1685 | */ |