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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/module.h> | |
21 | #include <linux/time.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/stat.h> | |
24 | #include <linux/fcntl.h> | |
25 | #include <linux/string.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/sunrpc/clnt.h> | |
30 | #include <linux/nfs_fs.h> | |
31 | #include <linux/nfs_mount.h> | |
32 | #include <linux/pagemap.h> | |
33 | #include <linux/pagevec.h> | |
34 | #include <linux/namei.h> | |
35 | #include <linux/mount.h> | |
36 | #include <linux/sched.h> | |
37 | #include <linux/kmemleak.h> | |
38 | #include <linux/xattr.h> | |
39 | ||
40 | #include "delegation.h" | |
41 | #include "iostat.h" | |
42 | #include "internal.h" | |
43 | #include "fscache.h" | |
44 | ||
45 | /* #define NFS_DEBUG_VERBOSE 1 */ | |
46 | ||
47 | static int nfs_opendir(struct inode *, struct file *); | |
48 | static int nfs_closedir(struct inode *, struct file *); | |
49 | static int nfs_readdir(struct file *, void *, filldir_t); | |
50 | static int nfs_fsync_dir(struct file *, loff_t, loff_t, int); | |
51 | static loff_t nfs_llseek_dir(struct file *, loff_t, int); | |
52 | static void nfs_readdir_clear_array(struct page*); | |
53 | ||
54 | const struct file_operations nfs_dir_operations = { | |
55 | .llseek = nfs_llseek_dir, | |
56 | .read = generic_read_dir, | |
57 | .readdir = nfs_readdir, | |
58 | .open = nfs_opendir, | |
59 | .release = nfs_closedir, | |
60 | .fsync = nfs_fsync_dir, | |
61 | }; | |
62 | ||
63 | const struct address_space_operations nfs_dir_aops = { | |
64 | .freepage = nfs_readdir_clear_array, | |
65 | }; | |
66 | ||
67 | static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct inode *dir, struct rpc_cred *cred) | |
68 | { | |
69 | struct nfs_open_dir_context *ctx; | |
70 | ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); | |
71 | if (ctx != NULL) { | |
72 | ctx->duped = 0; | |
73 | ctx->attr_gencount = NFS_I(dir)->attr_gencount; | |
74 | ctx->dir_cookie = 0; | |
75 | ctx->dup_cookie = 0; | |
76 | ctx->cred = get_rpccred(cred); | |
77 | return ctx; | |
78 | } | |
79 | return ERR_PTR(-ENOMEM); | |
80 | } | |
81 | ||
82 | static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx) | |
83 | { | |
84 | put_rpccred(ctx->cred); | |
85 | kfree(ctx); | |
86 | } | |
87 | ||
88 | /* | |
89 | * Open file | |
90 | */ | |
91 | static int | |
92 | nfs_opendir(struct inode *inode, struct file *filp) | |
93 | { | |
94 | int res = 0; | |
95 | struct nfs_open_dir_context *ctx; | |
96 | struct rpc_cred *cred; | |
97 | ||
98 | dfprintk(FILE, "NFS: open dir(%s/%s)\n", | |
99 | filp->f_path.dentry->d_parent->d_name.name, | |
100 | filp->f_path.dentry->d_name.name); | |
101 | ||
102 | nfs_inc_stats(inode, NFSIOS_VFSOPEN); | |
103 | ||
104 | cred = rpc_lookup_cred(); | |
105 | if (IS_ERR(cred)) | |
106 | return PTR_ERR(cred); | |
107 | ctx = alloc_nfs_open_dir_context(inode, cred); | |
108 | if (IS_ERR(ctx)) { | |
109 | res = PTR_ERR(ctx); | |
110 | goto out; | |
111 | } | |
112 | filp->private_data = ctx; | |
113 | if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) { | |
114 | /* This is a mountpoint, so d_revalidate will never | |
115 | * have been called, so we need to refresh the | |
116 | * inode (for close-open consistency) ourselves. | |
117 | */ | |
118 | __nfs_revalidate_inode(NFS_SERVER(inode), inode); | |
119 | } | |
120 | out: | |
121 | put_rpccred(cred); | |
122 | return res; | |
123 | } | |
124 | ||
125 | static int | |
126 | nfs_closedir(struct inode *inode, struct file *filp) | |
127 | { | |
128 | put_nfs_open_dir_context(filp->private_data); | |
129 | return 0; | |
130 | } | |
131 | ||
132 | struct nfs_cache_array_entry { | |
133 | u64 cookie; | |
134 | u64 ino; | |
135 | struct qstr string; | |
136 | unsigned char d_type; | |
137 | }; | |
138 | ||
139 | struct nfs_cache_array { | |
140 | int size; | |
141 | int eof_index; | |
142 | u64 last_cookie; | |
143 | struct nfs_cache_array_entry array[0]; | |
144 | }; | |
145 | ||
146 | typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int); | |
147 | typedef struct { | |
148 | struct file *file; | |
149 | struct page *page; | |
150 | unsigned long page_index; | |
151 | u64 *dir_cookie; | |
152 | u64 last_cookie; | |
153 | loff_t current_index; | |
154 | decode_dirent_t decode; | |
155 | ||
156 | unsigned long timestamp; | |
157 | unsigned long gencount; | |
158 | unsigned int cache_entry_index; | |
159 | unsigned int plus:1; | |
160 | unsigned int eof:1; | |
161 | } nfs_readdir_descriptor_t; | |
162 | ||
163 | /* | |
164 | * The caller is responsible for calling nfs_readdir_release_array(page) | |
165 | */ | |
166 | static | |
167 | struct nfs_cache_array *nfs_readdir_get_array(struct page *page) | |
168 | { | |
169 | void *ptr; | |
170 | if (page == NULL) | |
171 | return ERR_PTR(-EIO); | |
172 | ptr = kmap(page); | |
173 | if (ptr == NULL) | |
174 | return ERR_PTR(-ENOMEM); | |
175 | return ptr; | |
176 | } | |
177 | ||
178 | static | |
179 | void nfs_readdir_release_array(struct page *page) | |
180 | { | |
181 | kunmap(page); | |
182 | } | |
183 | ||
184 | /* | |
185 | * we are freeing strings created by nfs_add_to_readdir_array() | |
186 | */ | |
187 | static | |
188 | void nfs_readdir_clear_array(struct page *page) | |
189 | { | |
190 | struct nfs_cache_array *array; | |
191 | int i; | |
192 | ||
193 | array = kmap_atomic(page); | |
194 | for (i = 0; i < array->size; i++) | |
195 | kfree(array->array[i].string.name); | |
196 | kunmap_atomic(array); | |
197 | } | |
198 | ||
199 | /* | |
200 | * the caller is responsible for freeing qstr.name | |
201 | * when called by nfs_readdir_add_to_array, the strings will be freed in | |
202 | * nfs_clear_readdir_array() | |
203 | */ | |
204 | static | |
205 | int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len) | |
206 | { | |
207 | string->len = len; | |
208 | string->name = kmemdup(name, len, GFP_KERNEL); | |
209 | if (string->name == NULL) | |
210 | return -ENOMEM; | |
211 | /* | |
212 | * Avoid a kmemleak false positive. The pointer to the name is stored | |
213 | * in a page cache page which kmemleak does not scan. | |
214 | */ | |
215 | kmemleak_not_leak(string->name); | |
216 | string->hash = full_name_hash(name, len); | |
217 | return 0; | |
218 | } | |
219 | ||
220 | static | |
221 | int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) | |
222 | { | |
223 | struct nfs_cache_array *array = nfs_readdir_get_array(page); | |
224 | struct nfs_cache_array_entry *cache_entry; | |
225 | int ret; | |
226 | ||
227 | if (IS_ERR(array)) | |
228 | return PTR_ERR(array); | |
229 | ||
230 | cache_entry = &array->array[array->size]; | |
231 | ||
232 | /* Check that this entry lies within the page bounds */ | |
233 | ret = -ENOSPC; | |
234 | if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE) | |
235 | goto out; | |
236 | ||
237 | cache_entry->cookie = entry->prev_cookie; | |
238 | cache_entry->ino = entry->ino; | |
239 | cache_entry->d_type = entry->d_type; | |
240 | ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len); | |
241 | if (ret) | |
242 | goto out; | |
243 | array->last_cookie = entry->cookie; | |
244 | array->size++; | |
245 | if (entry->eof != 0) | |
246 | array->eof_index = array->size; | |
247 | out: | |
248 | nfs_readdir_release_array(page); | |
249 | return ret; | |
250 | } | |
251 | ||
252 | static | |
253 | int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) | |
254 | { | |
255 | loff_t diff = desc->file->f_pos - desc->current_index; | |
256 | unsigned int index; | |
257 | ||
258 | if (diff < 0) | |
259 | goto out_eof; | |
260 | if (diff >= array->size) { | |
261 | if (array->eof_index >= 0) | |
262 | goto out_eof; | |
263 | return -EAGAIN; | |
264 | } | |
265 | ||
266 | index = (unsigned int)diff; | |
267 | *desc->dir_cookie = array->array[index].cookie; | |
268 | desc->cache_entry_index = index; | |
269 | return 0; | |
270 | out_eof: | |
271 | desc->eof = 1; | |
272 | return -EBADCOOKIE; | |
273 | } | |
274 | ||
275 | static | |
276 | int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) | |
277 | { | |
278 | int i; | |
279 | loff_t new_pos; | |
280 | int status = -EAGAIN; | |
281 | ||
282 | for (i = 0; i < array->size; i++) { | |
283 | if (array->array[i].cookie == *desc->dir_cookie) { | |
284 | struct nfs_inode *nfsi = NFS_I(file_inode(desc->file)); | |
285 | struct nfs_open_dir_context *ctx = desc->file->private_data; | |
286 | ||
287 | new_pos = desc->current_index + i; | |
288 | if (ctx->attr_gencount != nfsi->attr_gencount | |
289 | || (nfsi->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))) { | |
290 | ctx->duped = 0; | |
291 | ctx->attr_gencount = nfsi->attr_gencount; | |
292 | } else if (new_pos < desc->file->f_pos) { | |
293 | if (ctx->duped > 0 | |
294 | && ctx->dup_cookie == *desc->dir_cookie) { | |
295 | if (printk_ratelimit()) { | |
296 | pr_notice("NFS: directory %s/%s contains a readdir loop." | |
297 | "Please contact your server vendor. " | |
298 | "The file: %s has duplicate cookie %llu\n", | |
299 | desc->file->f_dentry->d_parent->d_name.name, | |
300 | desc->file->f_dentry->d_name.name, | |
301 | array->array[i].string.name, | |
302 | *desc->dir_cookie); | |
303 | } | |
304 | status = -ELOOP; | |
305 | goto out; | |
306 | } | |
307 | ctx->dup_cookie = *desc->dir_cookie; | |
308 | ctx->duped = -1; | |
309 | } | |
310 | desc->file->f_pos = new_pos; | |
311 | desc->cache_entry_index = i; | |
312 | return 0; | |
313 | } | |
314 | } | |
315 | if (array->eof_index >= 0) { | |
316 | status = -EBADCOOKIE; | |
317 | if (*desc->dir_cookie == array->last_cookie) | |
318 | desc->eof = 1; | |
319 | } | |
320 | out: | |
321 | return status; | |
322 | } | |
323 | ||
324 | static | |
325 | int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc) | |
326 | { | |
327 | struct nfs_cache_array *array; | |
328 | int status; | |
329 | ||
330 | array = nfs_readdir_get_array(desc->page); | |
331 | if (IS_ERR(array)) { | |
332 | status = PTR_ERR(array); | |
333 | goto out; | |
334 | } | |
335 | ||
336 | if (*desc->dir_cookie == 0) | |
337 | status = nfs_readdir_search_for_pos(array, desc); | |
338 | else | |
339 | status = nfs_readdir_search_for_cookie(array, desc); | |
340 | ||
341 | if (status == -EAGAIN) { | |
342 | desc->last_cookie = array->last_cookie; | |
343 | desc->current_index += array->size; | |
344 | desc->page_index++; | |
345 | } | |
346 | nfs_readdir_release_array(desc->page); | |
347 | out: | |
348 | return status; | |
349 | } | |
350 | ||
351 | /* Fill a page with xdr information before transferring to the cache page */ | |
352 | static | |
353 | int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc, | |
354 | struct nfs_entry *entry, struct file *file, struct inode *inode) | |
355 | { | |
356 | struct nfs_open_dir_context *ctx = file->private_data; | |
357 | struct rpc_cred *cred = ctx->cred; | |
358 | unsigned long timestamp, gencount; | |
359 | int error; | |
360 | ||
361 | again: | |
362 | timestamp = jiffies; | |
363 | gencount = nfs_inc_attr_generation_counter(); | |
364 | error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages, | |
365 | NFS_SERVER(inode)->dtsize, desc->plus); | |
366 | if (error < 0) { | |
367 | /* We requested READDIRPLUS, but the server doesn't grok it */ | |
368 | if (error == -ENOTSUPP && desc->plus) { | |
369 | NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; | |
370 | clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); | |
371 | desc->plus = 0; | |
372 | goto again; | |
373 | } | |
374 | goto error; | |
375 | } | |
376 | desc->timestamp = timestamp; | |
377 | desc->gencount = gencount; | |
378 | error: | |
379 | return error; | |
380 | } | |
381 | ||
382 | static int xdr_decode(nfs_readdir_descriptor_t *desc, | |
383 | struct nfs_entry *entry, struct xdr_stream *xdr) | |
384 | { | |
385 | int error; | |
386 | ||
387 | error = desc->decode(xdr, entry, desc->plus); | |
388 | if (error) | |
389 | return error; | |
390 | entry->fattr->time_start = desc->timestamp; | |
391 | entry->fattr->gencount = desc->gencount; | |
392 | return 0; | |
393 | } | |
394 | ||
395 | static | |
396 | int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry) | |
397 | { | |
398 | if (dentry->d_inode == NULL) | |
399 | goto different; | |
400 | if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0) | |
401 | goto different; | |
402 | return 1; | |
403 | different: | |
404 | return 0; | |
405 | } | |
406 | ||
407 | static | |
408 | bool nfs_use_readdirplus(struct inode *dir, struct file *filp) | |
409 | { | |
410 | if (!nfs_server_capable(dir, NFS_CAP_READDIRPLUS)) | |
411 | return false; | |
412 | if (test_and_clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags)) | |
413 | return true; | |
414 | if (filp->f_pos == 0) | |
415 | return true; | |
416 | return false; | |
417 | } | |
418 | ||
419 | /* | |
420 | * This function is called by the lookup code to request the use of | |
421 | * readdirplus to accelerate any future lookups in the same | |
422 | * directory. | |
423 | */ | |
424 | static | |
425 | void nfs_advise_use_readdirplus(struct inode *dir) | |
426 | { | |
427 | set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(dir)->flags); | |
428 | } | |
429 | ||
430 | static | |
431 | void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) | |
432 | { | |
433 | struct qstr filename = QSTR_INIT(entry->name, entry->len); | |
434 | struct dentry *dentry; | |
435 | struct dentry *alias; | |
436 | struct inode *dir = parent->d_inode; | |
437 | struct inode *inode; | |
438 | ||
439 | if (filename.name[0] == '.') { | |
440 | if (filename.len == 1) | |
441 | return; | |
442 | if (filename.len == 2 && filename.name[1] == '.') | |
443 | return; | |
444 | } | |
445 | filename.hash = full_name_hash(filename.name, filename.len); | |
446 | ||
447 | dentry = d_lookup(parent, &filename); | |
448 | if (dentry != NULL) { | |
449 | if (nfs_same_file(dentry, entry)) { | |
450 | nfs_refresh_inode(dentry->d_inode, entry->fattr); | |
451 | goto out; | |
452 | } else { | |
453 | if (d_invalidate(dentry) != 0) | |
454 | goto out; | |
455 | dput(dentry); | |
456 | } | |
457 | } | |
458 | ||
459 | dentry = d_alloc(parent, &filename); | |
460 | if (dentry == NULL) | |
461 | return; | |
462 | ||
463 | inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); | |
464 | if (IS_ERR(inode)) | |
465 | goto out; | |
466 | ||
467 | alias = d_materialise_unique(dentry, inode); | |
468 | if (IS_ERR(alias)) | |
469 | goto out; | |
470 | else if (alias) { | |
471 | nfs_set_verifier(alias, nfs_save_change_attribute(dir)); | |
472 | dput(alias); | |
473 | } else | |
474 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
475 | ||
476 | out: | |
477 | dput(dentry); | |
478 | } | |
479 | ||
480 | /* Perform conversion from xdr to cache array */ | |
481 | static | |
482 | int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, | |
483 | struct page **xdr_pages, struct page *page, unsigned int buflen) | |
484 | { | |
485 | struct xdr_stream stream; | |
486 | struct xdr_buf buf; | |
487 | struct page *scratch; | |
488 | struct nfs_cache_array *array; | |
489 | unsigned int count = 0; | |
490 | int status; | |
491 | ||
492 | scratch = alloc_page(GFP_KERNEL); | |
493 | if (scratch == NULL) | |
494 | return -ENOMEM; | |
495 | ||
496 | xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen); | |
497 | xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE); | |
498 | ||
499 | do { | |
500 | status = xdr_decode(desc, entry, &stream); | |
501 | if (status != 0) { | |
502 | if (status == -EAGAIN) | |
503 | status = 0; | |
504 | break; | |
505 | } | |
506 | ||
507 | count++; | |
508 | ||
509 | if (desc->plus != 0) | |
510 | nfs_prime_dcache(desc->file->f_path.dentry, entry); | |
511 | ||
512 | status = nfs_readdir_add_to_array(entry, page); | |
513 | if (status != 0) | |
514 | break; | |
515 | } while (!entry->eof); | |
516 | ||
517 | if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) { | |
518 | array = nfs_readdir_get_array(page); | |
519 | if (!IS_ERR(array)) { | |
520 | array->eof_index = array->size; | |
521 | status = 0; | |
522 | nfs_readdir_release_array(page); | |
523 | } else | |
524 | status = PTR_ERR(array); | |
525 | } | |
526 | ||
527 | put_page(scratch); | |
528 | return status; | |
529 | } | |
530 | ||
531 | static | |
532 | void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages) | |
533 | { | |
534 | unsigned int i; | |
535 | for (i = 0; i < npages; i++) | |
536 | put_page(pages[i]); | |
537 | } | |
538 | ||
539 | static | |
540 | void nfs_readdir_free_large_page(void *ptr, struct page **pages, | |
541 | unsigned int npages) | |
542 | { | |
543 | nfs_readdir_free_pagearray(pages, npages); | |
544 | } | |
545 | ||
546 | /* | |
547 | * nfs_readdir_large_page will allocate pages that must be freed with a call | |
548 | * to nfs_readdir_free_large_page | |
549 | */ | |
550 | static | |
551 | int nfs_readdir_large_page(struct page **pages, unsigned int npages) | |
552 | { | |
553 | unsigned int i; | |
554 | ||
555 | for (i = 0; i < npages; i++) { | |
556 | struct page *page = alloc_page(GFP_KERNEL); | |
557 | if (page == NULL) | |
558 | goto out_freepages; | |
559 | pages[i] = page; | |
560 | } | |
561 | return 0; | |
562 | ||
563 | out_freepages: | |
564 | nfs_readdir_free_pagearray(pages, i); | |
565 | return -ENOMEM; | |
566 | } | |
567 | ||
568 | static | |
569 | int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode) | |
570 | { | |
571 | struct page *pages[NFS_MAX_READDIR_PAGES]; | |
572 | void *pages_ptr = NULL; | |
573 | struct nfs_entry entry; | |
574 | struct file *file = desc->file; | |
575 | struct nfs_cache_array *array; | |
576 | int status = -ENOMEM; | |
577 | unsigned int array_size = ARRAY_SIZE(pages); | |
578 | ||
579 | entry.prev_cookie = 0; | |
580 | entry.cookie = desc->last_cookie; | |
581 | entry.eof = 0; | |
582 | entry.fh = nfs_alloc_fhandle(); | |
583 | entry.fattr = nfs_alloc_fattr(); | |
584 | entry.server = NFS_SERVER(inode); | |
585 | if (entry.fh == NULL || entry.fattr == NULL) | |
586 | goto out; | |
587 | ||
588 | array = nfs_readdir_get_array(page); | |
589 | if (IS_ERR(array)) { | |
590 | status = PTR_ERR(array); | |
591 | goto out; | |
592 | } | |
593 | memset(array, 0, sizeof(struct nfs_cache_array)); | |
594 | array->eof_index = -1; | |
595 | ||
596 | status = nfs_readdir_large_page(pages, array_size); | |
597 | if (status < 0) | |
598 | goto out_release_array; | |
599 | do { | |
600 | unsigned int pglen; | |
601 | status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode); | |
602 | ||
603 | if (status < 0) | |
604 | break; | |
605 | pglen = status; | |
606 | status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen); | |
607 | if (status < 0) { | |
608 | if (status == -ENOSPC) | |
609 | status = 0; | |
610 | break; | |
611 | } | |
612 | } while (array->eof_index < 0); | |
613 | ||
614 | nfs_readdir_free_large_page(pages_ptr, pages, array_size); | |
615 | out_release_array: | |
616 | nfs_readdir_release_array(page); | |
617 | out: | |
618 | nfs_free_fattr(entry.fattr); | |
619 | nfs_free_fhandle(entry.fh); | |
620 | return status; | |
621 | } | |
622 | ||
623 | /* | |
624 | * Now we cache directories properly, by converting xdr information | |
625 | * to an array that can be used for lookups later. This results in | |
626 | * fewer cache pages, since we can store more information on each page. | |
627 | * We only need to convert from xdr once so future lookups are much simpler | |
628 | */ | |
629 | static | |
630 | int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page) | |
631 | { | |
632 | struct inode *inode = file_inode(desc->file); | |
633 | int ret; | |
634 | ||
635 | ret = nfs_readdir_xdr_to_array(desc, page, inode); | |
636 | if (ret < 0) | |
637 | goto error; | |
638 | SetPageUptodate(page); | |
639 | ||
640 | if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) { | |
641 | /* Should never happen */ | |
642 | nfs_zap_mapping(inode, inode->i_mapping); | |
643 | } | |
644 | unlock_page(page); | |
645 | return 0; | |
646 | error: | |
647 | unlock_page(page); | |
648 | return ret; | |
649 | } | |
650 | ||
651 | static | |
652 | void cache_page_release(nfs_readdir_descriptor_t *desc) | |
653 | { | |
654 | if (!desc->page->mapping) | |
655 | nfs_readdir_clear_array(desc->page); | |
656 | page_cache_release(desc->page); | |
657 | desc->page = NULL; | |
658 | } | |
659 | ||
660 | static | |
661 | struct page *get_cache_page(nfs_readdir_descriptor_t *desc) | |
662 | { | |
663 | return read_cache_page(file_inode(desc->file)->i_mapping, | |
664 | desc->page_index, (filler_t *)nfs_readdir_filler, desc); | |
665 | } | |
666 | ||
667 | /* | |
668 | * Returns 0 if desc->dir_cookie was found on page desc->page_index | |
669 | */ | |
670 | static | |
671 | int find_cache_page(nfs_readdir_descriptor_t *desc) | |
672 | { | |
673 | int res; | |
674 | ||
675 | desc->page = get_cache_page(desc); | |
676 | if (IS_ERR(desc->page)) | |
677 | return PTR_ERR(desc->page); | |
678 | ||
679 | res = nfs_readdir_search_array(desc); | |
680 | if (res != 0) | |
681 | cache_page_release(desc); | |
682 | return res; | |
683 | } | |
684 | ||
685 | /* Search for desc->dir_cookie from the beginning of the page cache */ | |
686 | static inline | |
687 | int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) | |
688 | { | |
689 | int res; | |
690 | ||
691 | if (desc->page_index == 0) { | |
692 | desc->current_index = 0; | |
693 | desc->last_cookie = 0; | |
694 | } | |
695 | do { | |
696 | res = find_cache_page(desc); | |
697 | } while (res == -EAGAIN); | |
698 | return res; | |
699 | } | |
700 | ||
701 | /* | |
702 | * Once we've found the start of the dirent within a page: fill 'er up... | |
703 | */ | |
704 | static | |
705 | int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, | |
706 | filldir_t filldir) | |
707 | { | |
708 | struct file *file = desc->file; | |
709 | int i = 0; | |
710 | int res = 0; | |
711 | struct nfs_cache_array *array = NULL; | |
712 | struct nfs_open_dir_context *ctx = file->private_data; | |
713 | ||
714 | array = nfs_readdir_get_array(desc->page); | |
715 | if (IS_ERR(array)) { | |
716 | res = PTR_ERR(array); | |
717 | goto out; | |
718 | } | |
719 | ||
720 | for (i = desc->cache_entry_index; i < array->size; i++) { | |
721 | struct nfs_cache_array_entry *ent; | |
722 | ||
723 | ent = &array->array[i]; | |
724 | if (filldir(dirent, ent->string.name, ent->string.len, | |
725 | file->f_pos, nfs_compat_user_ino64(ent->ino), | |
726 | ent->d_type) < 0) { | |
727 | desc->eof = 1; | |
728 | break; | |
729 | } | |
730 | file->f_pos++; | |
731 | if (i < (array->size-1)) | |
732 | *desc->dir_cookie = array->array[i+1].cookie; | |
733 | else | |
734 | *desc->dir_cookie = array->last_cookie; | |
735 | if (ctx->duped != 0) | |
736 | ctx->duped = 1; | |
737 | } | |
738 | if (array->eof_index >= 0) | |
739 | desc->eof = 1; | |
740 | ||
741 | nfs_readdir_release_array(desc->page); | |
742 | out: | |
743 | cache_page_release(desc); | |
744 | dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", | |
745 | (unsigned long long)*desc->dir_cookie, res); | |
746 | return res; | |
747 | } | |
748 | ||
749 | /* | |
750 | * If we cannot find a cookie in our cache, we suspect that this is | |
751 | * because it points to a deleted file, so we ask the server to return | |
752 | * whatever it thinks is the next entry. We then feed this to filldir. | |
753 | * If all goes well, we should then be able to find our way round the | |
754 | * cache on the next call to readdir_search_pagecache(); | |
755 | * | |
756 | * NOTE: we cannot add the anonymous page to the pagecache because | |
757 | * the data it contains might not be page aligned. Besides, | |
758 | * we should already have a complete representation of the | |
759 | * directory in the page cache by the time we get here. | |
760 | */ | |
761 | static inline | |
762 | int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent, | |
763 | filldir_t filldir) | |
764 | { | |
765 | struct page *page = NULL; | |
766 | int status; | |
767 | struct inode *inode = file_inode(desc->file); | |
768 | struct nfs_open_dir_context *ctx = desc->file->private_data; | |
769 | ||
770 | dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n", | |
771 | (unsigned long long)*desc->dir_cookie); | |
772 | ||
773 | page = alloc_page(GFP_HIGHUSER); | |
774 | if (!page) { | |
775 | status = -ENOMEM; | |
776 | goto out; | |
777 | } | |
778 | ||
779 | desc->page_index = 0; | |
780 | desc->last_cookie = *desc->dir_cookie; | |
781 | desc->page = page; | |
782 | ctx->duped = 0; | |
783 | ||
784 | status = nfs_readdir_xdr_to_array(desc, page, inode); | |
785 | if (status < 0) | |
786 | goto out_release; | |
787 | ||
788 | status = nfs_do_filldir(desc, dirent, filldir); | |
789 | ||
790 | out: | |
791 | dfprintk(DIRCACHE, "NFS: %s: returns %d\n", | |
792 | __func__, status); | |
793 | return status; | |
794 | out_release: | |
795 | cache_page_release(desc); | |
796 | goto out; | |
797 | } | |
798 | ||
799 | /* The file offset position represents the dirent entry number. A | |
800 | last cookie cache takes care of the common case of reading the | |
801 | whole directory. | |
802 | */ | |
803 | static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir) | |
804 | { | |
805 | struct dentry *dentry = filp->f_path.dentry; | |
806 | struct inode *inode = dentry->d_inode; | |
807 | nfs_readdir_descriptor_t my_desc, | |
808 | *desc = &my_desc; | |
809 | struct nfs_open_dir_context *dir_ctx = filp->private_data; | |
810 | int res; | |
811 | ||
812 | dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n", | |
813 | dentry->d_parent->d_name.name, dentry->d_name.name, | |
814 | (long long)filp->f_pos); | |
815 | nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); | |
816 | ||
817 | /* | |
818 | * filp->f_pos points to the dirent entry number. | |
819 | * *desc->dir_cookie has the cookie for the next entry. We have | |
820 | * to either find the entry with the appropriate number or | |
821 | * revalidate the cookie. | |
822 | */ | |
823 | memset(desc, 0, sizeof(*desc)); | |
824 | ||
825 | desc->file = filp; | |
826 | desc->dir_cookie = &dir_ctx->dir_cookie; | |
827 | desc->decode = NFS_PROTO(inode)->decode_dirent; | |
828 | desc->plus = nfs_use_readdirplus(inode, filp) ? 1 : 0; | |
829 | ||
830 | nfs_block_sillyrename(dentry); | |
831 | res = nfs_revalidate_mapping(inode, filp->f_mapping); | |
832 | if (res < 0) | |
833 | goto out; | |
834 | ||
835 | do { | |
836 | res = readdir_search_pagecache(desc); | |
837 | ||
838 | if (res == -EBADCOOKIE) { | |
839 | res = 0; | |
840 | /* This means either end of directory */ | |
841 | if (*desc->dir_cookie && desc->eof == 0) { | |
842 | /* Or that the server has 'lost' a cookie */ | |
843 | res = uncached_readdir(desc, dirent, filldir); | |
844 | if (res == 0) | |
845 | continue; | |
846 | } | |
847 | break; | |
848 | } | |
849 | if (res == -ETOOSMALL && desc->plus) { | |
850 | clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); | |
851 | nfs_zap_caches(inode); | |
852 | desc->page_index = 0; | |
853 | desc->plus = 0; | |
854 | desc->eof = 0; | |
855 | continue; | |
856 | } | |
857 | if (res < 0) | |
858 | break; | |
859 | ||
860 | res = nfs_do_filldir(desc, dirent, filldir); | |
861 | if (res < 0) | |
862 | break; | |
863 | } while (!desc->eof); | |
864 | out: | |
865 | nfs_unblock_sillyrename(dentry); | |
866 | if (res > 0) | |
867 | res = 0; | |
868 | dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n", | |
869 | dentry->d_parent->d_name.name, dentry->d_name.name, | |
870 | res); | |
871 | return res; | |
872 | } | |
873 | ||
874 | static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence) | |
875 | { | |
876 | struct dentry *dentry = filp->f_path.dentry; | |
877 | struct inode *inode = dentry->d_inode; | |
878 | struct nfs_open_dir_context *dir_ctx = filp->private_data; | |
879 | ||
880 | dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n", | |
881 | dentry->d_parent->d_name.name, | |
882 | dentry->d_name.name, | |
883 | offset, whence); | |
884 | ||
885 | mutex_lock(&inode->i_mutex); | |
886 | switch (whence) { | |
887 | case 1: | |
888 | offset += filp->f_pos; | |
889 | case 0: | |
890 | if (offset >= 0) | |
891 | break; | |
892 | default: | |
893 | offset = -EINVAL; | |
894 | goto out; | |
895 | } | |
896 | if (offset != filp->f_pos) { | |
897 | filp->f_pos = offset; | |
898 | dir_ctx->dir_cookie = 0; | |
899 | dir_ctx->duped = 0; | |
900 | } | |
901 | out: | |
902 | mutex_unlock(&inode->i_mutex); | |
903 | return offset; | |
904 | } | |
905 | ||
906 | /* | |
907 | * All directory operations under NFS are synchronous, so fsync() | |
908 | * is a dummy operation. | |
909 | */ | |
910 | static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end, | |
911 | int datasync) | |
912 | { | |
913 | struct dentry *dentry = filp->f_path.dentry; | |
914 | struct inode *inode = dentry->d_inode; | |
915 | ||
916 | dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n", | |
917 | dentry->d_parent->d_name.name, dentry->d_name.name, | |
918 | datasync); | |
919 | ||
920 | mutex_lock(&inode->i_mutex); | |
921 | nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC); | |
922 | mutex_unlock(&inode->i_mutex); | |
923 | return 0; | |
924 | } | |
925 | ||
926 | /** | |
927 | * nfs_force_lookup_revalidate - Mark the directory as having changed | |
928 | * @dir - pointer to directory inode | |
929 | * | |
930 | * This forces the revalidation code in nfs_lookup_revalidate() to do a | |
931 | * full lookup on all child dentries of 'dir' whenever a change occurs | |
932 | * on the server that might have invalidated our dcache. | |
933 | * | |
934 | * The caller should be holding dir->i_lock | |
935 | */ | |
936 | void nfs_force_lookup_revalidate(struct inode *dir) | |
937 | { | |
938 | NFS_I(dir)->cache_change_attribute++; | |
939 | } | |
940 | EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate); | |
941 | ||
942 | /* | |
943 | * A check for whether or not the parent directory has changed. | |
944 | * In the case it has, we assume that the dentries are untrustworthy | |
945 | * and may need to be looked up again. | |
946 | */ | |
947 | static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) | |
948 | { | |
949 | if (IS_ROOT(dentry)) | |
950 | return 1; | |
951 | if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) | |
952 | return 0; | |
953 | if (!nfs_verify_change_attribute(dir, dentry->d_time)) | |
954 | return 0; | |
955 | /* Revalidate nfsi->cache_change_attribute before we declare a match */ | |
956 | if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) | |
957 | return 0; | |
958 | if (!nfs_verify_change_attribute(dir, dentry->d_time)) | |
959 | return 0; | |
960 | return 1; | |
961 | } | |
962 | ||
963 | /* | |
964 | * Use intent information to check whether or not we're going to do | |
965 | * an O_EXCL create using this path component. | |
966 | */ | |
967 | static int nfs_is_exclusive_create(struct inode *dir, unsigned int flags) | |
968 | { | |
969 | if (NFS_PROTO(dir)->version == 2) | |
970 | return 0; | |
971 | return flags & LOOKUP_EXCL; | |
972 | } | |
973 | ||
974 | /* | |
975 | * Inode and filehandle revalidation for lookups. | |
976 | * | |
977 | * We force revalidation in the cases where the VFS sets LOOKUP_REVAL, | |
978 | * or if the intent information indicates that we're about to open this | |
979 | * particular file and the "nocto" mount flag is not set. | |
980 | * | |
981 | */ | |
982 | static | |
983 | int nfs_lookup_verify_inode(struct inode *inode, unsigned int flags) | |
984 | { | |
985 | struct nfs_server *server = NFS_SERVER(inode); | |
986 | int ret; | |
987 | ||
988 | if (IS_AUTOMOUNT(inode)) | |
989 | return 0; | |
990 | /* VFS wants an on-the-wire revalidation */ | |
991 | if (flags & LOOKUP_REVAL) | |
992 | goto out_force; | |
993 | /* This is an open(2) */ | |
994 | if ((flags & LOOKUP_OPEN) && !(server->flags & NFS_MOUNT_NOCTO) && | |
995 | (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) | |
996 | goto out_force; | |
997 | out: | |
998 | return (inode->i_nlink == 0) ? -ENOENT : 0; | |
999 | out_force: | |
1000 | ret = __nfs_revalidate_inode(server, inode); | |
1001 | if (ret != 0) | |
1002 | return ret; | |
1003 | goto out; | |
1004 | } | |
1005 | ||
1006 | /* | |
1007 | * We judge how long we want to trust negative | |
1008 | * dentries by looking at the parent inode mtime. | |
1009 | * | |
1010 | * If parent mtime has changed, we revalidate, else we wait for a | |
1011 | * period corresponding to the parent's attribute cache timeout value. | |
1012 | */ | |
1013 | static inline | |
1014 | int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, | |
1015 | unsigned int flags) | |
1016 | { | |
1017 | /* Don't revalidate a negative dentry if we're creating a new file */ | |
1018 | if (flags & LOOKUP_CREATE) | |
1019 | return 0; | |
1020 | if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) | |
1021 | return 1; | |
1022 | return !nfs_check_verifier(dir, dentry); | |
1023 | } | |
1024 | ||
1025 | /* | |
1026 | * This is called every time the dcache has a lookup hit, | |
1027 | * and we should check whether we can really trust that | |
1028 | * lookup. | |
1029 | * | |
1030 | * NOTE! The hit can be a negative hit too, don't assume | |
1031 | * we have an inode! | |
1032 | * | |
1033 | * If the parent directory is seen to have changed, we throw out the | |
1034 | * cached dentry and do a new lookup. | |
1035 | */ | |
1036 | static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags) | |
1037 | { | |
1038 | struct inode *dir; | |
1039 | struct inode *inode; | |
1040 | struct dentry *parent; | |
1041 | struct nfs_fh *fhandle = NULL; | |
1042 | struct nfs_fattr *fattr = NULL; | |
1043 | int error; | |
1044 | ||
1045 | if (flags & LOOKUP_RCU) | |
1046 | return -ECHILD; | |
1047 | ||
1048 | parent = dget_parent(dentry); | |
1049 | dir = parent->d_inode; | |
1050 | nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); | |
1051 | inode = dentry->d_inode; | |
1052 | ||
1053 | if (!inode) { | |
1054 | if (nfs_neg_need_reval(dir, dentry, flags)) | |
1055 | goto out_bad; | |
1056 | goto out_valid_noent; | |
1057 | } | |
1058 | ||
1059 | if (is_bad_inode(inode)) { | |
1060 | dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n", | |
1061 | __func__, dentry->d_parent->d_name.name, | |
1062 | dentry->d_name.name); | |
1063 | goto out_bad; | |
1064 | } | |
1065 | ||
1066 | if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ)) | |
1067 | goto out_set_verifier; | |
1068 | ||
1069 | /* Force a full look up iff the parent directory has changed */ | |
1070 | if (!nfs_is_exclusive_create(dir, flags) && nfs_check_verifier(dir, dentry)) { | |
1071 | if (nfs_lookup_verify_inode(inode, flags)) | |
1072 | goto out_zap_parent; | |
1073 | goto out_valid; | |
1074 | } | |
1075 | ||
1076 | if (NFS_STALE(inode)) | |
1077 | goto out_bad; | |
1078 | ||
1079 | error = -ENOMEM; | |
1080 | fhandle = nfs_alloc_fhandle(); | |
1081 | fattr = nfs_alloc_fattr(); | |
1082 | if (fhandle == NULL || fattr == NULL) | |
1083 | goto out_error; | |
1084 | ||
1085 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr); | |
1086 | if (error) | |
1087 | goto out_bad; | |
1088 | if (nfs_compare_fh(NFS_FH(inode), fhandle)) | |
1089 | goto out_bad; | |
1090 | if ((error = nfs_refresh_inode(inode, fattr)) != 0) | |
1091 | goto out_bad; | |
1092 | ||
1093 | nfs_free_fattr(fattr); | |
1094 | nfs_free_fhandle(fhandle); | |
1095 | out_set_verifier: | |
1096 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1097 | out_valid: | |
1098 | /* Success: notify readdir to use READDIRPLUS */ | |
1099 | nfs_advise_use_readdirplus(dir); | |
1100 | out_valid_noent: | |
1101 | dput(parent); | |
1102 | dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n", | |
1103 | __func__, dentry->d_parent->d_name.name, | |
1104 | dentry->d_name.name); | |
1105 | return 1; | |
1106 | out_zap_parent: | |
1107 | nfs_zap_caches(dir); | |
1108 | out_bad: | |
1109 | nfs_free_fattr(fattr); | |
1110 | nfs_free_fhandle(fhandle); | |
1111 | nfs_mark_for_revalidate(dir); | |
1112 | if (inode && S_ISDIR(inode->i_mode)) { | |
1113 | /* Purge readdir caches. */ | |
1114 | nfs_zap_caches(inode); | |
1115 | /* If we have submounts, don't unhash ! */ | |
1116 | if (have_submounts(dentry)) | |
1117 | goto out_valid; | |
1118 | if (dentry->d_flags & DCACHE_DISCONNECTED) | |
1119 | goto out_valid; | |
1120 | shrink_dcache_parent(dentry); | |
1121 | } | |
1122 | d_drop(dentry); | |
1123 | dput(parent); | |
1124 | dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", | |
1125 | __func__, dentry->d_parent->d_name.name, | |
1126 | dentry->d_name.name); | |
1127 | return 0; | |
1128 | out_error: | |
1129 | nfs_free_fattr(fattr); | |
1130 | nfs_free_fhandle(fhandle); | |
1131 | dput(parent); | |
1132 | dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n", | |
1133 | __func__, dentry->d_parent->d_name.name, | |
1134 | dentry->d_name.name, error); | |
1135 | return error; | |
1136 | } | |
1137 | ||
1138 | /* | |
1139 | * A weaker form of d_revalidate for revalidating just the dentry->d_inode | |
1140 | * when we don't really care about the dentry name. This is called when a | |
1141 | * pathwalk ends on a dentry that was not found via a normal lookup in the | |
1142 | * parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals). | |
1143 | * | |
1144 | * In this situation, we just want to verify that the inode itself is OK | |
1145 | * since the dentry might have changed on the server. | |
1146 | */ | |
1147 | static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags) | |
1148 | { | |
1149 | int error; | |
1150 | struct inode *inode = dentry->d_inode; | |
1151 | ||
1152 | /* | |
1153 | * I believe we can only get a negative dentry here in the case of a | |
1154 | * procfs-style symlink. Just assume it's correct for now, but we may | |
1155 | * eventually need to do something more here. | |
1156 | */ | |
1157 | if (!inode) { | |
1158 | dfprintk(LOOKUPCACHE, "%s: %s/%s has negative inode\n", | |
1159 | __func__, dentry->d_parent->d_name.name, | |
1160 | dentry->d_name.name); | |
1161 | return 1; | |
1162 | } | |
1163 | ||
1164 | if (is_bad_inode(inode)) { | |
1165 | dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n", | |
1166 | __func__, dentry->d_parent->d_name.name, | |
1167 | dentry->d_name.name); | |
1168 | return 0; | |
1169 | } | |
1170 | ||
1171 | error = nfs_revalidate_inode(NFS_SERVER(inode), inode); | |
1172 | dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n", | |
1173 | __func__, inode->i_ino, error ? "invalid" : "valid"); | |
1174 | return !error; | |
1175 | } | |
1176 | ||
1177 | /* | |
1178 | * This is called from dput() when d_count is going to 0. | |
1179 | */ | |
1180 | static int nfs_dentry_delete(const struct dentry *dentry) | |
1181 | { | |
1182 | dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", | |
1183 | dentry->d_parent->d_name.name, dentry->d_name.name, | |
1184 | dentry->d_flags); | |
1185 | ||
1186 | /* Unhash any dentry with a stale inode */ | |
1187 | if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode)) | |
1188 | return 1; | |
1189 | ||
1190 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { | |
1191 | /* Unhash it, so that ->d_iput() would be called */ | |
1192 | return 1; | |
1193 | } | |
1194 | if (!(dentry->d_sb->s_flags & MS_ACTIVE)) { | |
1195 | /* Unhash it, so that ancestors of killed async unlink | |
1196 | * files will be cleaned up during umount */ | |
1197 | return 1; | |
1198 | } | |
1199 | return 0; | |
1200 | ||
1201 | } | |
1202 | ||
1203 | /* Ensure that we revalidate inode->i_nlink */ | |
1204 | static void nfs_drop_nlink(struct inode *inode) | |
1205 | { | |
1206 | spin_lock(&inode->i_lock); | |
1207 | /* drop the inode if we're reasonably sure this is the last link */ | |
1208 | if (inode->i_nlink == 1) | |
1209 | clear_nlink(inode); | |
1210 | NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATTR; | |
1211 | spin_unlock(&inode->i_lock); | |
1212 | } | |
1213 | ||
1214 | /* | |
1215 | * Called when the dentry loses inode. | |
1216 | * We use it to clean up silly-renamed files. | |
1217 | */ | |
1218 | static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) | |
1219 | { | |
1220 | if (S_ISDIR(inode->i_mode)) | |
1221 | /* drop any readdir cache as it could easily be old */ | |
1222 | NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA; | |
1223 | ||
1224 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { | |
1225 | nfs_complete_unlink(dentry, inode); | |
1226 | nfs_drop_nlink(inode); | |
1227 | } | |
1228 | iput(inode); | |
1229 | } | |
1230 | ||
1231 | static void nfs_d_release(struct dentry *dentry) | |
1232 | { | |
1233 | /* free cached devname value, if it survived that far */ | |
1234 | if (unlikely(dentry->d_fsdata)) { | |
1235 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) | |
1236 | WARN_ON(1); | |
1237 | else | |
1238 | kfree(dentry->d_fsdata); | |
1239 | } | |
1240 | } | |
1241 | ||
1242 | const struct dentry_operations nfs_dentry_operations = { | |
1243 | .d_revalidate = nfs_lookup_revalidate, | |
1244 | .d_weak_revalidate = nfs_weak_revalidate, | |
1245 | .d_delete = nfs_dentry_delete, | |
1246 | .d_iput = nfs_dentry_iput, | |
1247 | .d_automount = nfs_d_automount, | |
1248 | .d_release = nfs_d_release, | |
1249 | }; | |
1250 | EXPORT_SYMBOL_GPL(nfs_dentry_operations); | |
1251 | ||
1252 | struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags) | |
1253 | { | |
1254 | struct dentry *res; | |
1255 | struct dentry *parent; | |
1256 | struct inode *inode = NULL; | |
1257 | struct nfs_fh *fhandle = NULL; | |
1258 | struct nfs_fattr *fattr = NULL; | |
1259 | int error; | |
1260 | ||
1261 | dfprintk(VFS, "NFS: lookup(%s/%s)\n", | |
1262 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
1263 | nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); | |
1264 | ||
1265 | res = ERR_PTR(-ENAMETOOLONG); | |
1266 | if (dentry->d_name.len > NFS_SERVER(dir)->namelen) | |
1267 | goto out; | |
1268 | ||
1269 | /* | |
1270 | * If we're doing an exclusive create, optimize away the lookup | |
1271 | * but don't hash the dentry. | |
1272 | */ | |
1273 | if (nfs_is_exclusive_create(dir, flags)) { | |
1274 | d_instantiate(dentry, NULL); | |
1275 | res = NULL; | |
1276 | goto out; | |
1277 | } | |
1278 | ||
1279 | res = ERR_PTR(-ENOMEM); | |
1280 | fhandle = nfs_alloc_fhandle(); | |
1281 | fattr = nfs_alloc_fattr(); | |
1282 | if (fhandle == NULL || fattr == NULL) | |
1283 | goto out; | |
1284 | ||
1285 | parent = dentry->d_parent; | |
1286 | /* Protect against concurrent sillydeletes */ | |
1287 | nfs_block_sillyrename(parent); | |
1288 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr); | |
1289 | if (error == -ENOENT) | |
1290 | goto no_entry; | |
1291 | if (error < 0) { | |
1292 | res = ERR_PTR(error); | |
1293 | goto out_unblock_sillyrename; | |
1294 | } | |
1295 | inode = nfs_fhget(dentry->d_sb, fhandle, fattr); | |
1296 | res = ERR_CAST(inode); | |
1297 | if (IS_ERR(res)) | |
1298 | goto out_unblock_sillyrename; | |
1299 | ||
1300 | /* Success: notify readdir to use READDIRPLUS */ | |
1301 | nfs_advise_use_readdirplus(dir); | |
1302 | ||
1303 | no_entry: | |
1304 | res = d_materialise_unique(dentry, inode); | |
1305 | if (res != NULL) { | |
1306 | if (IS_ERR(res)) | |
1307 | goto out_unblock_sillyrename; | |
1308 | dentry = res; | |
1309 | } | |
1310 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1311 | out_unblock_sillyrename: | |
1312 | nfs_unblock_sillyrename(parent); | |
1313 | out: | |
1314 | nfs_free_fattr(fattr); | |
1315 | nfs_free_fhandle(fhandle); | |
1316 | return res; | |
1317 | } | |
1318 | EXPORT_SYMBOL_GPL(nfs_lookup); | |
1319 | ||
1320 | #if IS_ENABLED(CONFIG_NFS_V4) | |
1321 | static int nfs4_lookup_revalidate(struct dentry *, unsigned int); | |
1322 | ||
1323 | const struct dentry_operations nfs4_dentry_operations = { | |
1324 | .d_revalidate = nfs4_lookup_revalidate, | |
1325 | .d_delete = nfs_dentry_delete, | |
1326 | .d_iput = nfs_dentry_iput, | |
1327 | .d_automount = nfs_d_automount, | |
1328 | .d_release = nfs_d_release, | |
1329 | }; | |
1330 | EXPORT_SYMBOL_GPL(nfs4_dentry_operations); | |
1331 | ||
1332 | static fmode_t flags_to_mode(int flags) | |
1333 | { | |
1334 | fmode_t res = (__force fmode_t)flags & FMODE_EXEC; | |
1335 | if ((flags & O_ACCMODE) != O_WRONLY) | |
1336 | res |= FMODE_READ; | |
1337 | if ((flags & O_ACCMODE) != O_RDONLY) | |
1338 | res |= FMODE_WRITE; | |
1339 | return res; | |
1340 | } | |
1341 | ||
1342 | static struct nfs_open_context *create_nfs_open_context(struct dentry *dentry, int open_flags) | |
1343 | { | |
1344 | return alloc_nfs_open_context(dentry, flags_to_mode(open_flags)); | |
1345 | } | |
1346 | ||
1347 | static int do_open(struct inode *inode, struct file *filp) | |
1348 | { | |
1349 | nfs_fscache_set_inode_cookie(inode, filp); | |
1350 | return 0; | |
1351 | } | |
1352 | ||
1353 | static int nfs_finish_open(struct nfs_open_context *ctx, | |
1354 | struct dentry *dentry, | |
1355 | struct file *file, unsigned open_flags, | |
1356 | int *opened) | |
1357 | { | |
1358 | int err; | |
1359 | ||
1360 | if (ctx->dentry != dentry) { | |
1361 | dput(ctx->dentry); | |
1362 | ctx->dentry = dget(dentry); | |
1363 | } | |
1364 | ||
1365 | /* If the open_intent is for execute, we have an extra check to make */ | |
1366 | if (ctx->mode & FMODE_EXEC) { | |
1367 | err = nfs_may_open(dentry->d_inode, ctx->cred, open_flags); | |
1368 | if (err < 0) | |
1369 | goto out; | |
1370 | } | |
1371 | ||
1372 | err = finish_open(file, dentry, do_open, opened); | |
1373 | if (err) | |
1374 | goto out; | |
1375 | nfs_file_set_open_context(file, ctx); | |
1376 | ||
1377 | out: | |
1378 | put_nfs_open_context(ctx); | |
1379 | return err; | |
1380 | } | |
1381 | ||
1382 | int nfs_atomic_open(struct inode *dir, struct dentry *dentry, | |
1383 | struct file *file, unsigned open_flags, | |
1384 | umode_t mode, int *opened) | |
1385 | { | |
1386 | struct nfs_open_context *ctx; | |
1387 | struct dentry *res; | |
1388 | struct iattr attr = { .ia_valid = ATTR_OPEN }; | |
1389 | struct inode *inode; | |
1390 | int err; | |
1391 | ||
1392 | /* Expect a negative dentry */ | |
1393 | BUG_ON(dentry->d_inode); | |
1394 | ||
1395 | dfprintk(VFS, "NFS: atomic_open(%s/%ld), %s\n", | |
1396 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); | |
1397 | ||
1398 | /* NFS only supports OPEN on regular files */ | |
1399 | if ((open_flags & O_DIRECTORY)) { | |
1400 | if (!d_unhashed(dentry)) { | |
1401 | /* | |
1402 | * Hashed negative dentry with O_DIRECTORY: dentry was | |
1403 | * revalidated and is fine, no need to perform lookup | |
1404 | * again | |
1405 | */ | |
1406 | return -ENOENT; | |
1407 | } | |
1408 | goto no_open; | |
1409 | } | |
1410 | ||
1411 | if (dentry->d_name.len > NFS_SERVER(dir)->namelen) | |
1412 | return -ENAMETOOLONG; | |
1413 | ||
1414 | if (open_flags & O_CREAT) { | |
1415 | attr.ia_valid |= ATTR_MODE; | |
1416 | attr.ia_mode = mode & ~current_umask(); | |
1417 | } | |
1418 | if (open_flags & O_TRUNC) { | |
1419 | attr.ia_valid |= ATTR_SIZE; | |
1420 | attr.ia_size = 0; | |
1421 | } | |
1422 | ||
1423 | ctx = create_nfs_open_context(dentry, open_flags); | |
1424 | err = PTR_ERR(ctx); | |
1425 | if (IS_ERR(ctx)) | |
1426 | goto out; | |
1427 | ||
1428 | nfs_block_sillyrename(dentry->d_parent); | |
1429 | inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr); | |
1430 | d_drop(dentry); | |
1431 | if (IS_ERR(inode)) { | |
1432 | nfs_unblock_sillyrename(dentry->d_parent); | |
1433 | put_nfs_open_context(ctx); | |
1434 | err = PTR_ERR(inode); | |
1435 | switch (err) { | |
1436 | case -ENOENT: | |
1437 | d_add(dentry, NULL); | |
1438 | break; | |
1439 | case -EISDIR: | |
1440 | case -ENOTDIR: | |
1441 | goto no_open; | |
1442 | case -ELOOP: | |
1443 | if (!(open_flags & O_NOFOLLOW)) | |
1444 | goto no_open; | |
1445 | break; | |
1446 | /* case -EINVAL: */ | |
1447 | default: | |
1448 | break; | |
1449 | } | |
1450 | goto out; | |
1451 | } | |
1452 | res = d_add_unique(dentry, inode); | |
1453 | if (res != NULL) | |
1454 | dentry = res; | |
1455 | ||
1456 | nfs_unblock_sillyrename(dentry->d_parent); | |
1457 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1458 | ||
1459 | err = nfs_finish_open(ctx, dentry, file, open_flags, opened); | |
1460 | ||
1461 | dput(res); | |
1462 | out: | |
1463 | return err; | |
1464 | ||
1465 | no_open: | |
1466 | res = nfs_lookup(dir, dentry, 0); | |
1467 | err = PTR_ERR(res); | |
1468 | if (IS_ERR(res)) | |
1469 | goto out; | |
1470 | ||
1471 | return finish_no_open(file, res); | |
1472 | } | |
1473 | EXPORT_SYMBOL_GPL(nfs_atomic_open); | |
1474 | ||
1475 | static int nfs4_lookup_revalidate(struct dentry *dentry, unsigned int flags) | |
1476 | { | |
1477 | struct dentry *parent = NULL; | |
1478 | struct inode *inode; | |
1479 | struct inode *dir; | |
1480 | int ret = 0; | |
1481 | ||
1482 | if (flags & LOOKUP_RCU) | |
1483 | return -ECHILD; | |
1484 | ||
1485 | if (!(flags & LOOKUP_OPEN) || (flags & LOOKUP_DIRECTORY)) | |
1486 | goto no_open; | |
1487 | if (d_mountpoint(dentry)) | |
1488 | goto no_open; | |
1489 | if (NFS_SB(dentry->d_sb)->caps & NFS_CAP_ATOMIC_OPEN_V1) | |
1490 | goto no_open; | |
1491 | ||
1492 | inode = dentry->d_inode; | |
1493 | parent = dget_parent(dentry); | |
1494 | dir = parent->d_inode; | |
1495 | ||
1496 | /* We can't create new files in nfs_open_revalidate(), so we | |
1497 | * optimize away revalidation of negative dentries. | |
1498 | */ | |
1499 | if (inode == NULL) { | |
1500 | if (!nfs_neg_need_reval(dir, dentry, flags)) | |
1501 | ret = 1; | |
1502 | goto out; | |
1503 | } | |
1504 | ||
1505 | /* NFS only supports OPEN on regular files */ | |
1506 | if (!S_ISREG(inode->i_mode)) | |
1507 | goto no_open_dput; | |
1508 | /* We cannot do exclusive creation on a positive dentry */ | |
1509 | if (flags & LOOKUP_EXCL) | |
1510 | goto no_open_dput; | |
1511 | ||
1512 | /* Let f_op->open() actually open (and revalidate) the file */ | |
1513 | ret = 1; | |
1514 | ||
1515 | out: | |
1516 | dput(parent); | |
1517 | return ret; | |
1518 | ||
1519 | no_open_dput: | |
1520 | dput(parent); | |
1521 | no_open: | |
1522 | return nfs_lookup_revalidate(dentry, flags); | |
1523 | } | |
1524 | ||
1525 | #endif /* CONFIG_NFSV4 */ | |
1526 | ||
1527 | /* | |
1528 | * Code common to create, mkdir, and mknod. | |
1529 | */ | |
1530 | int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, | |
1531 | struct nfs_fattr *fattr) | |
1532 | { | |
1533 | struct dentry *parent = dget_parent(dentry); | |
1534 | struct inode *dir = parent->d_inode; | |
1535 | struct inode *inode; | |
1536 | int error = -EACCES; | |
1537 | ||
1538 | d_drop(dentry); | |
1539 | ||
1540 | /* We may have been initialized further down */ | |
1541 | if (dentry->d_inode) | |
1542 | goto out; | |
1543 | if (fhandle->size == 0) { | |
1544 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr); | |
1545 | if (error) | |
1546 | goto out_error; | |
1547 | } | |
1548 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1549 | if (!(fattr->valid & NFS_ATTR_FATTR)) { | |
1550 | struct nfs_server *server = NFS_SB(dentry->d_sb); | |
1551 | error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr); | |
1552 | if (error < 0) | |
1553 | goto out_error; | |
1554 | } | |
1555 | inode = nfs_fhget(dentry->d_sb, fhandle, fattr); | |
1556 | error = PTR_ERR(inode); | |
1557 | if (IS_ERR(inode)) | |
1558 | goto out_error; | |
1559 | d_add(dentry, inode); | |
1560 | out: | |
1561 | dput(parent); | |
1562 | return 0; | |
1563 | out_error: | |
1564 | nfs_mark_for_revalidate(dir); | |
1565 | dput(parent); | |
1566 | return error; | |
1567 | } | |
1568 | EXPORT_SYMBOL_GPL(nfs_instantiate); | |
1569 | ||
1570 | /* | |
1571 | * Following a failed create operation, we drop the dentry rather | |
1572 | * than retain a negative dentry. This avoids a problem in the event | |
1573 | * that the operation succeeded on the server, but an error in the | |
1574 | * reply path made it appear to have failed. | |
1575 | */ | |
1576 | int nfs_create(struct inode *dir, struct dentry *dentry, | |
1577 | umode_t mode, bool excl) | |
1578 | { | |
1579 | struct iattr attr; | |
1580 | int open_flags = excl ? O_CREAT | O_EXCL : O_CREAT; | |
1581 | int error; | |
1582 | ||
1583 | dfprintk(VFS, "NFS: create(%s/%ld), %s\n", | |
1584 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); | |
1585 | ||
1586 | attr.ia_mode = mode; | |
1587 | attr.ia_valid = ATTR_MODE; | |
1588 | ||
1589 | error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags); | |
1590 | if (error != 0) | |
1591 | goto out_err; | |
1592 | return 0; | |
1593 | out_err: | |
1594 | d_drop(dentry); | |
1595 | return error; | |
1596 | } | |
1597 | EXPORT_SYMBOL_GPL(nfs_create); | |
1598 | ||
1599 | /* | |
1600 | * See comments for nfs_proc_create regarding failed operations. | |
1601 | */ | |
1602 | int | |
1603 | nfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) | |
1604 | { | |
1605 | struct iattr attr; | |
1606 | int status; | |
1607 | ||
1608 | dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n", | |
1609 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); | |
1610 | ||
1611 | if (!new_valid_dev(rdev)) | |
1612 | return -EINVAL; | |
1613 | ||
1614 | attr.ia_mode = mode; | |
1615 | attr.ia_valid = ATTR_MODE; | |
1616 | ||
1617 | status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); | |
1618 | if (status != 0) | |
1619 | goto out_err; | |
1620 | return 0; | |
1621 | out_err: | |
1622 | d_drop(dentry); | |
1623 | return status; | |
1624 | } | |
1625 | EXPORT_SYMBOL_GPL(nfs_mknod); | |
1626 | ||
1627 | /* | |
1628 | * See comments for nfs_proc_create regarding failed operations. | |
1629 | */ | |
1630 | int nfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) | |
1631 | { | |
1632 | struct iattr attr; | |
1633 | int error; | |
1634 | ||
1635 | dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n", | |
1636 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); | |
1637 | ||
1638 | attr.ia_valid = ATTR_MODE; | |
1639 | attr.ia_mode = mode | S_IFDIR; | |
1640 | ||
1641 | error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); | |
1642 | if (error != 0) | |
1643 | goto out_err; | |
1644 | return 0; | |
1645 | out_err: | |
1646 | d_drop(dentry); | |
1647 | return error; | |
1648 | } | |
1649 | EXPORT_SYMBOL_GPL(nfs_mkdir); | |
1650 | ||
1651 | static void nfs_dentry_handle_enoent(struct dentry *dentry) | |
1652 | { | |
1653 | if (dentry->d_inode != NULL && !d_unhashed(dentry)) | |
1654 | d_delete(dentry); | |
1655 | } | |
1656 | ||
1657 | int nfs_rmdir(struct inode *dir, struct dentry *dentry) | |
1658 | { | |
1659 | int error; | |
1660 | ||
1661 | dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n", | |
1662 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); | |
1663 | ||
1664 | error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); | |
1665 | /* Ensure the VFS deletes this inode */ | |
1666 | if (error == 0 && dentry->d_inode != NULL) | |
1667 | clear_nlink(dentry->d_inode); | |
1668 | else if (error == -ENOENT) | |
1669 | nfs_dentry_handle_enoent(dentry); | |
1670 | ||
1671 | return error; | |
1672 | } | |
1673 | EXPORT_SYMBOL_GPL(nfs_rmdir); | |
1674 | ||
1675 | /* | |
1676 | * Remove a file after making sure there are no pending writes, | |
1677 | * and after checking that the file has only one user. | |
1678 | * | |
1679 | * We invalidate the attribute cache and free the inode prior to the operation | |
1680 | * to avoid possible races if the server reuses the inode. | |
1681 | */ | |
1682 | static int nfs_safe_remove(struct dentry *dentry) | |
1683 | { | |
1684 | struct inode *dir = dentry->d_parent->d_inode; | |
1685 | struct inode *inode = dentry->d_inode; | |
1686 | int error = -EBUSY; | |
1687 | ||
1688 | dfprintk(VFS, "NFS: safe_remove(%s/%s)\n", | |
1689 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
1690 | ||
1691 | /* If the dentry was sillyrenamed, we simply call d_delete() */ | |
1692 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { | |
1693 | error = 0; | |
1694 | goto out; | |
1695 | } | |
1696 | ||
1697 | if (inode != NULL) { | |
1698 | NFS_PROTO(inode)->return_delegation(inode); | |
1699 | error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); | |
1700 | if (error == 0) | |
1701 | nfs_drop_nlink(inode); | |
1702 | } else | |
1703 | error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); | |
1704 | if (error == -ENOENT) | |
1705 | nfs_dentry_handle_enoent(dentry); | |
1706 | out: | |
1707 | return error; | |
1708 | } | |
1709 | ||
1710 | /* We do silly rename. In case sillyrename() returns -EBUSY, the inode | |
1711 | * belongs to an active ".nfs..." file and we return -EBUSY. | |
1712 | * | |
1713 | * If sillyrename() returns 0, we do nothing, otherwise we unlink. | |
1714 | */ | |
1715 | int nfs_unlink(struct inode *dir, struct dentry *dentry) | |
1716 | { | |
1717 | int error; | |
1718 | int need_rehash = 0; | |
1719 | ||
1720 | dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, | |
1721 | dir->i_ino, dentry->d_name.name); | |
1722 | ||
1723 | spin_lock(&dentry->d_lock); | |
1724 | if (dentry->d_count > 1) { | |
1725 | spin_unlock(&dentry->d_lock); | |
1726 | /* Start asynchronous writeout of the inode */ | |
1727 | write_inode_now(dentry->d_inode, 0); | |
1728 | error = nfs_sillyrename(dir, dentry); | |
1729 | return error; | |
1730 | } | |
1731 | if (!d_unhashed(dentry)) { | |
1732 | __d_drop(dentry); | |
1733 | need_rehash = 1; | |
1734 | } | |
1735 | spin_unlock(&dentry->d_lock); | |
1736 | error = nfs_safe_remove(dentry); | |
1737 | if (!error || error == -ENOENT) { | |
1738 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); | |
1739 | } else if (need_rehash) | |
1740 | d_rehash(dentry); | |
1741 | return error; | |
1742 | } | |
1743 | EXPORT_SYMBOL_GPL(nfs_unlink); | |
1744 | ||
1745 | /* | |
1746 | * To create a symbolic link, most file systems instantiate a new inode, | |
1747 | * add a page to it containing the path, then write it out to the disk | |
1748 | * using prepare_write/commit_write. | |
1749 | * | |
1750 | * Unfortunately the NFS client can't create the in-core inode first | |
1751 | * because it needs a file handle to create an in-core inode (see | |
1752 | * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the | |
1753 | * symlink request has completed on the server. | |
1754 | * | |
1755 | * So instead we allocate a raw page, copy the symname into it, then do | |
1756 | * the SYMLINK request with the page as the buffer. If it succeeds, we | |
1757 | * now have a new file handle and can instantiate an in-core NFS inode | |
1758 | * and move the raw page into its mapping. | |
1759 | */ | |
1760 | int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) | |
1761 | { | |
1762 | struct pagevec lru_pvec; | |
1763 | struct page *page; | |
1764 | char *kaddr; | |
1765 | struct iattr attr; | |
1766 | unsigned int pathlen = strlen(symname); | |
1767 | int error; | |
1768 | ||
1769 | dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id, | |
1770 | dir->i_ino, dentry->d_name.name, symname); | |
1771 | ||
1772 | if (pathlen > PAGE_SIZE) | |
1773 | return -ENAMETOOLONG; | |
1774 | ||
1775 | attr.ia_mode = S_IFLNK | S_IRWXUGO; | |
1776 | attr.ia_valid = ATTR_MODE; | |
1777 | ||
1778 | page = alloc_page(GFP_HIGHUSER); | |
1779 | if (!page) | |
1780 | return -ENOMEM; | |
1781 | ||
1782 | kaddr = kmap_atomic(page); | |
1783 | memcpy(kaddr, symname, pathlen); | |
1784 | if (pathlen < PAGE_SIZE) | |
1785 | memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); | |
1786 | kunmap_atomic(kaddr); | |
1787 | ||
1788 | error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); | |
1789 | if (error != 0) { | |
1790 | dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n", | |
1791 | dir->i_sb->s_id, dir->i_ino, | |
1792 | dentry->d_name.name, symname, error); | |
1793 | d_drop(dentry); | |
1794 | __free_page(page); | |
1795 | return error; | |
1796 | } | |
1797 | ||
1798 | /* | |
1799 | * No big deal if we can't add this page to the page cache here. | |
1800 | * READLINK will get the missing page from the server if needed. | |
1801 | */ | |
1802 | pagevec_init(&lru_pvec, 0); | |
1803 | if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0, | |
1804 | GFP_KERNEL)) { | |
1805 | pagevec_add(&lru_pvec, page); | |
1806 | pagevec_lru_add_file(&lru_pvec); | |
1807 | SetPageUptodate(page); | |
1808 | unlock_page(page); | |
1809 | } else | |
1810 | __free_page(page); | |
1811 | ||
1812 | return 0; | |
1813 | } | |
1814 | EXPORT_SYMBOL_GPL(nfs_symlink); | |
1815 | ||
1816 | int | |
1817 | nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) | |
1818 | { | |
1819 | struct inode *inode = old_dentry->d_inode; | |
1820 | int error; | |
1821 | ||
1822 | dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n", | |
1823 | old_dentry->d_parent->d_name.name, old_dentry->d_name.name, | |
1824 | dentry->d_parent->d_name.name, dentry->d_name.name); | |
1825 | ||
1826 | NFS_PROTO(inode)->return_delegation(inode); | |
1827 | ||
1828 | d_drop(dentry); | |
1829 | error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); | |
1830 | if (error == 0) { | |
1831 | ihold(inode); | |
1832 | d_add(dentry, inode); | |
1833 | } | |
1834 | return error; | |
1835 | } | |
1836 | EXPORT_SYMBOL_GPL(nfs_link); | |
1837 | ||
1838 | /* | |
1839 | * RENAME | |
1840 | * FIXME: Some nfsds, like the Linux user space nfsd, may generate a | |
1841 | * different file handle for the same inode after a rename (e.g. when | |
1842 | * moving to a different directory). A fail-safe method to do so would | |
1843 | * be to look up old_dir/old_name, create a link to new_dir/new_name and | |
1844 | * rename the old file using the sillyrename stuff. This way, the original | |
1845 | * file in old_dir will go away when the last process iput()s the inode. | |
1846 | * | |
1847 | * FIXED. | |
1848 | * | |
1849 | * It actually works quite well. One needs to have the possibility for | |
1850 | * at least one ".nfs..." file in each directory the file ever gets | |
1851 | * moved or linked to which happens automagically with the new | |
1852 | * implementation that only depends on the dcache stuff instead of | |
1853 | * using the inode layer | |
1854 | * | |
1855 | * Unfortunately, things are a little more complicated than indicated | |
1856 | * above. For a cross-directory move, we want to make sure we can get | |
1857 | * rid of the old inode after the operation. This means there must be | |
1858 | * no pending writes (if it's a file), and the use count must be 1. | |
1859 | * If these conditions are met, we can drop the dentries before doing | |
1860 | * the rename. | |
1861 | */ | |
1862 | int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, | |
1863 | struct inode *new_dir, struct dentry *new_dentry) | |
1864 | { | |
1865 | struct inode *old_inode = old_dentry->d_inode; | |
1866 | struct inode *new_inode = new_dentry->d_inode; | |
1867 | struct dentry *dentry = NULL, *rehash = NULL; | |
1868 | int error = -EBUSY; | |
1869 | ||
1870 | dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", | |
1871 | old_dentry->d_parent->d_name.name, old_dentry->d_name.name, | |
1872 | new_dentry->d_parent->d_name.name, new_dentry->d_name.name, | |
1873 | new_dentry->d_count); | |
1874 | ||
1875 | /* | |
1876 | * For non-directories, check whether the target is busy and if so, | |
1877 | * make a copy of the dentry and then do a silly-rename. If the | |
1878 | * silly-rename succeeds, the copied dentry is hashed and becomes | |
1879 | * the new target. | |
1880 | */ | |
1881 | if (new_inode && !S_ISDIR(new_inode->i_mode)) { | |
1882 | /* | |
1883 | * To prevent any new references to the target during the | |
1884 | * rename, we unhash the dentry in advance. | |
1885 | */ | |
1886 | if (!d_unhashed(new_dentry)) { | |
1887 | d_drop(new_dentry); | |
1888 | rehash = new_dentry; | |
1889 | } | |
1890 | ||
1891 | if (new_dentry->d_count > 2) { | |
1892 | int err; | |
1893 | ||
1894 | /* copy the target dentry's name */ | |
1895 | dentry = d_alloc(new_dentry->d_parent, | |
1896 | &new_dentry->d_name); | |
1897 | if (!dentry) | |
1898 | goto out; | |
1899 | ||
1900 | /* silly-rename the existing target ... */ | |
1901 | err = nfs_sillyrename(new_dir, new_dentry); | |
1902 | if (err) | |
1903 | goto out; | |
1904 | ||
1905 | new_dentry = dentry; | |
1906 | rehash = NULL; | |
1907 | new_inode = NULL; | |
1908 | } | |
1909 | } | |
1910 | ||
1911 | NFS_PROTO(old_inode)->return_delegation(old_inode); | |
1912 | if (new_inode != NULL) | |
1913 | NFS_PROTO(new_inode)->return_delegation(new_inode); | |
1914 | ||
1915 | error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name, | |
1916 | new_dir, &new_dentry->d_name); | |
1917 | nfs_mark_for_revalidate(old_inode); | |
1918 | out: | |
1919 | if (rehash) | |
1920 | d_rehash(rehash); | |
1921 | if (!error) { | |
1922 | if (new_inode != NULL) | |
1923 | nfs_drop_nlink(new_inode); | |
1924 | d_move(old_dentry, new_dentry); | |
1925 | nfs_set_verifier(new_dentry, | |
1926 | nfs_save_change_attribute(new_dir)); | |
1927 | } else if (error == -ENOENT) | |
1928 | nfs_dentry_handle_enoent(old_dentry); | |
1929 | ||
1930 | /* new dentry created? */ | |
1931 | if (dentry) | |
1932 | dput(dentry); | |
1933 | return error; | |
1934 | } | |
1935 | EXPORT_SYMBOL_GPL(nfs_rename); | |
1936 | ||
1937 | static DEFINE_SPINLOCK(nfs_access_lru_lock); | |
1938 | static LIST_HEAD(nfs_access_lru_list); | |
1939 | static atomic_long_t nfs_access_nr_entries; | |
1940 | ||
1941 | static void nfs_access_free_entry(struct nfs_access_entry *entry) | |
1942 | { | |
1943 | put_rpccred(entry->cred); | |
1944 | kfree(entry); | |
1945 | smp_mb__before_atomic_dec(); | |
1946 | atomic_long_dec(&nfs_access_nr_entries); | |
1947 | smp_mb__after_atomic_dec(); | |
1948 | } | |
1949 | ||
1950 | static void nfs_access_free_list(struct list_head *head) | |
1951 | { | |
1952 | struct nfs_access_entry *cache; | |
1953 | ||
1954 | while (!list_empty(head)) { | |
1955 | cache = list_entry(head->next, struct nfs_access_entry, lru); | |
1956 | list_del(&cache->lru); | |
1957 | nfs_access_free_entry(cache); | |
1958 | } | |
1959 | } | |
1960 | ||
1961 | int nfs_access_cache_shrinker(struct shrinker *shrink, | |
1962 | struct shrink_control *sc) | |
1963 | { | |
1964 | LIST_HEAD(head); | |
1965 | struct nfs_inode *nfsi, *next; | |
1966 | struct nfs_access_entry *cache; | |
1967 | int nr_to_scan = sc->nr_to_scan; | |
1968 | gfp_t gfp_mask = sc->gfp_mask; | |
1969 | ||
1970 | if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL) | |
1971 | return (nr_to_scan == 0) ? 0 : -1; | |
1972 | ||
1973 | spin_lock(&nfs_access_lru_lock); | |
1974 | list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) { | |
1975 | struct inode *inode; | |
1976 | ||
1977 | if (nr_to_scan-- == 0) | |
1978 | break; | |
1979 | inode = &nfsi->vfs_inode; | |
1980 | spin_lock(&inode->i_lock); | |
1981 | if (list_empty(&nfsi->access_cache_entry_lru)) | |
1982 | goto remove_lru_entry; | |
1983 | cache = list_entry(nfsi->access_cache_entry_lru.next, | |
1984 | struct nfs_access_entry, lru); | |
1985 | list_move(&cache->lru, &head); | |
1986 | rb_erase(&cache->rb_node, &nfsi->access_cache); | |
1987 | if (!list_empty(&nfsi->access_cache_entry_lru)) | |
1988 | list_move_tail(&nfsi->access_cache_inode_lru, | |
1989 | &nfs_access_lru_list); | |
1990 | else { | |
1991 | remove_lru_entry: | |
1992 | list_del_init(&nfsi->access_cache_inode_lru); | |
1993 | smp_mb__before_clear_bit(); | |
1994 | clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); | |
1995 | smp_mb__after_clear_bit(); | |
1996 | } | |
1997 | spin_unlock(&inode->i_lock); | |
1998 | } | |
1999 | spin_unlock(&nfs_access_lru_lock); | |
2000 | nfs_access_free_list(&head); | |
2001 | return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; | |
2002 | } | |
2003 | ||
2004 | static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head) | |
2005 | { | |
2006 | struct rb_root *root_node = &nfsi->access_cache; | |
2007 | struct rb_node *n; | |
2008 | struct nfs_access_entry *entry; | |
2009 | ||
2010 | /* Unhook entries from the cache */ | |
2011 | while ((n = rb_first(root_node)) != NULL) { | |
2012 | entry = rb_entry(n, struct nfs_access_entry, rb_node); | |
2013 | rb_erase(n, root_node); | |
2014 | list_move(&entry->lru, head); | |
2015 | } | |
2016 | nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; | |
2017 | } | |
2018 | ||
2019 | void nfs_access_zap_cache(struct inode *inode) | |
2020 | { | |
2021 | LIST_HEAD(head); | |
2022 | ||
2023 | if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0) | |
2024 | return; | |
2025 | /* Remove from global LRU init */ | |
2026 | spin_lock(&nfs_access_lru_lock); | |
2027 | if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) | |
2028 | list_del_init(&NFS_I(inode)->access_cache_inode_lru); | |
2029 | ||
2030 | spin_lock(&inode->i_lock); | |
2031 | __nfs_access_zap_cache(NFS_I(inode), &head); | |
2032 | spin_unlock(&inode->i_lock); | |
2033 | spin_unlock(&nfs_access_lru_lock); | |
2034 | nfs_access_free_list(&head); | |
2035 | } | |
2036 | EXPORT_SYMBOL_GPL(nfs_access_zap_cache); | |
2037 | ||
2038 | static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred) | |
2039 | { | |
2040 | struct rb_node *n = NFS_I(inode)->access_cache.rb_node; | |
2041 | struct nfs_access_entry *entry; | |
2042 | ||
2043 | while (n != NULL) { | |
2044 | entry = rb_entry(n, struct nfs_access_entry, rb_node); | |
2045 | ||
2046 | if (cred < entry->cred) | |
2047 | n = n->rb_left; | |
2048 | else if (cred > entry->cred) | |
2049 | n = n->rb_right; | |
2050 | else | |
2051 | return entry; | |
2052 | } | |
2053 | return NULL; | |
2054 | } | |
2055 | ||
2056 | static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) | |
2057 | { | |
2058 | struct nfs_inode *nfsi = NFS_I(inode); | |
2059 | struct nfs_access_entry *cache; | |
2060 | int err = -ENOENT; | |
2061 | ||
2062 | spin_lock(&inode->i_lock); | |
2063 | if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) | |
2064 | goto out_zap; | |
2065 | cache = nfs_access_search_rbtree(inode, cred); | |
2066 | if (cache == NULL) | |
2067 | goto out; | |
2068 | if (!nfs_have_delegated_attributes(inode) && | |
2069 | !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo)) | |
2070 | goto out_stale; | |
2071 | res->jiffies = cache->jiffies; | |
2072 | res->cred = cache->cred; | |
2073 | res->mask = cache->mask; | |
2074 | list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); | |
2075 | err = 0; | |
2076 | out: | |
2077 | spin_unlock(&inode->i_lock); | |
2078 | return err; | |
2079 | out_stale: | |
2080 | rb_erase(&cache->rb_node, &nfsi->access_cache); | |
2081 | list_del(&cache->lru); | |
2082 | spin_unlock(&inode->i_lock); | |
2083 | nfs_access_free_entry(cache); | |
2084 | return -ENOENT; | |
2085 | out_zap: | |
2086 | spin_unlock(&inode->i_lock); | |
2087 | nfs_access_zap_cache(inode); | |
2088 | return -ENOENT; | |
2089 | } | |
2090 | ||
2091 | static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) | |
2092 | { | |
2093 | struct nfs_inode *nfsi = NFS_I(inode); | |
2094 | struct rb_root *root_node = &nfsi->access_cache; | |
2095 | struct rb_node **p = &root_node->rb_node; | |
2096 | struct rb_node *parent = NULL; | |
2097 | struct nfs_access_entry *entry; | |
2098 | ||
2099 | spin_lock(&inode->i_lock); | |
2100 | while (*p != NULL) { | |
2101 | parent = *p; | |
2102 | entry = rb_entry(parent, struct nfs_access_entry, rb_node); | |
2103 | ||
2104 | if (set->cred < entry->cred) | |
2105 | p = &parent->rb_left; | |
2106 | else if (set->cred > entry->cred) | |
2107 | p = &parent->rb_right; | |
2108 | else | |
2109 | goto found; | |
2110 | } | |
2111 | rb_link_node(&set->rb_node, parent, p); | |
2112 | rb_insert_color(&set->rb_node, root_node); | |
2113 | list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); | |
2114 | spin_unlock(&inode->i_lock); | |
2115 | return; | |
2116 | found: | |
2117 | rb_replace_node(parent, &set->rb_node, root_node); | |
2118 | list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); | |
2119 | list_del(&entry->lru); | |
2120 | spin_unlock(&inode->i_lock); | |
2121 | nfs_access_free_entry(entry); | |
2122 | } | |
2123 | ||
2124 | void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) | |
2125 | { | |
2126 | struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); | |
2127 | if (cache == NULL) | |
2128 | return; | |
2129 | RB_CLEAR_NODE(&cache->rb_node); | |
2130 | cache->jiffies = set->jiffies; | |
2131 | cache->cred = get_rpccred(set->cred); | |
2132 | cache->mask = set->mask; | |
2133 | ||
2134 | nfs_access_add_rbtree(inode, cache); | |
2135 | ||
2136 | /* Update accounting */ | |
2137 | smp_mb__before_atomic_inc(); | |
2138 | atomic_long_inc(&nfs_access_nr_entries); | |
2139 | smp_mb__after_atomic_inc(); | |
2140 | ||
2141 | /* Add inode to global LRU list */ | |
2142 | if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { | |
2143 | spin_lock(&nfs_access_lru_lock); | |
2144 | if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) | |
2145 | list_add_tail(&NFS_I(inode)->access_cache_inode_lru, | |
2146 | &nfs_access_lru_list); | |
2147 | spin_unlock(&nfs_access_lru_lock); | |
2148 | } | |
2149 | } | |
2150 | EXPORT_SYMBOL_GPL(nfs_access_add_cache); | |
2151 | ||
2152 | void nfs_access_set_mask(struct nfs_access_entry *entry, u32 access_result) | |
2153 | { | |
2154 | entry->mask = 0; | |
2155 | if (access_result & NFS4_ACCESS_READ) | |
2156 | entry->mask |= MAY_READ; | |
2157 | if (access_result & | |
2158 | (NFS4_ACCESS_MODIFY | NFS4_ACCESS_EXTEND | NFS4_ACCESS_DELETE)) | |
2159 | entry->mask |= MAY_WRITE; | |
2160 | if (access_result & (NFS4_ACCESS_LOOKUP|NFS4_ACCESS_EXECUTE)) | |
2161 | entry->mask |= MAY_EXEC; | |
2162 | } | |
2163 | EXPORT_SYMBOL_GPL(nfs_access_set_mask); | |
2164 | ||
2165 | static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) | |
2166 | { | |
2167 | struct nfs_access_entry cache; | |
2168 | int status; | |
2169 | ||
2170 | status = nfs_access_get_cached(inode, cred, &cache); | |
2171 | if (status == 0) | |
2172 | goto out; | |
2173 | ||
2174 | /* Be clever: ask server to check for all possible rights */ | |
2175 | cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; | |
2176 | cache.cred = cred; | |
2177 | cache.jiffies = jiffies; | |
2178 | status = NFS_PROTO(inode)->access(inode, &cache); | |
2179 | if (status != 0) { | |
2180 | if (status == -ESTALE) { | |
2181 | nfs_zap_caches(inode); | |
2182 | if (!S_ISDIR(inode->i_mode)) | |
2183 | set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); | |
2184 | } | |
2185 | return status; | |
2186 | } | |
2187 | nfs_access_add_cache(inode, &cache); | |
2188 | out: | |
2189 | if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) | |
2190 | return 0; | |
2191 | return -EACCES; | |
2192 | } | |
2193 | ||
2194 | static int nfs_open_permission_mask(int openflags) | |
2195 | { | |
2196 | int mask = 0; | |
2197 | ||
2198 | if (openflags & __FMODE_EXEC) { | |
2199 | /* ONLY check exec rights */ | |
2200 | mask = MAY_EXEC; | |
2201 | } else { | |
2202 | if ((openflags & O_ACCMODE) != O_WRONLY) | |
2203 | mask |= MAY_READ; | |
2204 | if ((openflags & O_ACCMODE) != O_RDONLY) | |
2205 | mask |= MAY_WRITE; | |
2206 | } | |
2207 | ||
2208 | return mask; | |
2209 | } | |
2210 | ||
2211 | int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) | |
2212 | { | |
2213 | return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); | |
2214 | } | |
2215 | EXPORT_SYMBOL_GPL(nfs_may_open); | |
2216 | ||
2217 | int nfs_permission(struct inode *inode, int mask) | |
2218 | { | |
2219 | struct rpc_cred *cred; | |
2220 | int res = 0; | |
2221 | ||
2222 | if (mask & MAY_NOT_BLOCK) | |
2223 | return -ECHILD; | |
2224 | ||
2225 | nfs_inc_stats(inode, NFSIOS_VFSACCESS); | |
2226 | ||
2227 | if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) | |
2228 | goto out; | |
2229 | /* Is this sys_access() ? */ | |
2230 | if (mask & (MAY_ACCESS | MAY_CHDIR)) | |
2231 | goto force_lookup; | |
2232 | ||
2233 | switch (inode->i_mode & S_IFMT) { | |
2234 | case S_IFLNK: | |
2235 | goto out; | |
2236 | case S_IFREG: | |
2237 | /* NFSv4 has atomic_open... */ | |
2238 | if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) | |
2239 | && (mask & MAY_OPEN) | |
2240 | && !(mask & MAY_EXEC)) | |
2241 | goto out; | |
2242 | break; | |
2243 | case S_IFDIR: | |
2244 | /* | |
2245 | * Optimize away all write operations, since the server | |
2246 | * will check permissions when we perform the op. | |
2247 | */ | |
2248 | if ((mask & MAY_WRITE) && !(mask & MAY_READ)) | |
2249 | goto out; | |
2250 | } | |
2251 | ||
2252 | force_lookup: | |
2253 | if (!NFS_PROTO(inode)->access) | |
2254 | goto out_notsup; | |
2255 | ||
2256 | cred = rpc_lookup_cred(); | |
2257 | if (!IS_ERR(cred)) { | |
2258 | res = nfs_do_access(inode, cred, mask); | |
2259 | put_rpccred(cred); | |
2260 | } else | |
2261 | res = PTR_ERR(cred); | |
2262 | out: | |
2263 | if (!res && (mask & MAY_EXEC) && !execute_ok(inode)) | |
2264 | res = -EACCES; | |
2265 | ||
2266 | dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n", | |
2267 | inode->i_sb->s_id, inode->i_ino, mask, res); | |
2268 | return res; | |
2269 | out_notsup: | |
2270 | res = nfs_revalidate_inode(NFS_SERVER(inode), inode); | |
2271 | if (res == 0) | |
2272 | res = generic_permission(inode, mask); | |
2273 | goto out; | |
2274 | } | |
2275 | EXPORT_SYMBOL_GPL(nfs_permission); | |
2276 | ||
2277 | /* | |
2278 | * Local variables: | |
2279 | * version-control: t | |
2280 | * kept-new-versions: 5 | |
2281 | * End: | |
2282 | */ |