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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/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/pagevec.h> |
33 | #include <linux/namei.h> |
34 | #include <linux/mount.h> |
35 | #include <linux/sched.h> |
36 | #include <linux/kmemleak.h> |
37 | #include <linux/xattr.h> |
38 | |
39 | #include "delegation.h" |
40 | #include "iostat.h" |
41 | #include "internal.h" |
42 | #include "fscache.h" |
43 | |
44 | /* #define NFS_DEBUG_VERBOSE 1 */ |
45 | |
46 | static int nfs_opendir(struct inode *, struct file *); |
47 | static int nfs_closedir(struct inode *, struct file *); |
48 | static int nfs_readdir(struct file *, void *, filldir_t); |
49 | static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *); |
50 | static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *); |
51 | static int nfs_mkdir(struct inode *, struct dentry *, int); |
52 | static int nfs_rmdir(struct inode *, struct dentry *); |
53 | static int nfs_unlink(struct inode *, struct dentry *); |
54 | static int nfs_symlink(struct inode *, struct dentry *, const char *); |
55 | static int nfs_link(struct dentry *, struct inode *, struct dentry *); |
56 | static int nfs_mknod(struct inode *, struct dentry *, int, dev_t); |
57 | static int nfs_rename(struct inode *, struct dentry *, |
58 | struct inode *, struct dentry *); |
59 | static int nfs_fsync_dir(struct file *, int); |
60 | static loff_t nfs_llseek_dir(struct file *, loff_t, int); |
61 | static void nfs_readdir_clear_array(struct page*); |
62 | |
63 | const struct file_operations nfs_dir_operations = { |
64 | .llseek = nfs_llseek_dir, |
65 | .read = generic_read_dir, |
66 | .readdir = nfs_readdir, |
67 | .open = nfs_opendir, |
68 | .release = nfs_closedir, |
69 | .fsync = nfs_fsync_dir, |
70 | }; |
71 | |
72 | const struct inode_operations nfs_dir_inode_operations = { |
73 | .create = nfs_create, |
74 | .lookup = nfs_lookup, |
75 | .link = nfs_link, |
76 | .unlink = nfs_unlink, |
77 | .symlink = nfs_symlink, |
78 | .mkdir = nfs_mkdir, |
79 | .rmdir = nfs_rmdir, |
80 | .mknod = nfs_mknod, |
81 | .rename = nfs_rename, |
82 | .permission = nfs_permission, |
83 | .getattr = nfs_getattr, |
84 | .setattr = nfs_setattr, |
85 | }; |
86 | |
87 | const struct address_space_operations nfs_dir_aops = { |
88 | .freepage = nfs_readdir_clear_array, |
89 | }; |
90 | |
91 | #ifdef CONFIG_NFS_V3 |
92 | const struct inode_operations nfs3_dir_inode_operations = { |
93 | .create = nfs_create, |
94 | .lookup = nfs_lookup, |
95 | .link = nfs_link, |
96 | .unlink = nfs_unlink, |
97 | .symlink = nfs_symlink, |
98 | .mkdir = nfs_mkdir, |
99 | .rmdir = nfs_rmdir, |
100 | .mknod = nfs_mknod, |
101 | .rename = nfs_rename, |
102 | .permission = nfs_permission, |
103 | .getattr = nfs_getattr, |
104 | .setattr = nfs_setattr, |
105 | .listxattr = nfs3_listxattr, |
106 | .getxattr = nfs3_getxattr, |
107 | .setxattr = nfs3_setxattr, |
108 | .removexattr = nfs3_removexattr, |
109 | }; |
110 | #endif /* CONFIG_NFS_V3 */ |
111 | |
112 | #ifdef CONFIG_NFS_V4 |
113 | |
114 | static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *); |
115 | static int nfs_open_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd); |
116 | const struct inode_operations nfs4_dir_inode_operations = { |
117 | .create = nfs_open_create, |
118 | .lookup = nfs_atomic_lookup, |
119 | .link = nfs_link, |
120 | .unlink = nfs_unlink, |
121 | .symlink = nfs_symlink, |
122 | .mkdir = nfs_mkdir, |
123 | .rmdir = nfs_rmdir, |
124 | .mknod = nfs_mknod, |
125 | .rename = nfs_rename, |
126 | .permission = nfs_permission, |
127 | .getattr = nfs_getattr, |
128 | .setattr = nfs_setattr, |
129 | .getxattr = generic_getxattr, |
130 | .setxattr = generic_setxattr, |
131 | .listxattr = generic_listxattr, |
132 | .removexattr = generic_removexattr, |
133 | }; |
134 | |
135 | #endif /* CONFIG_NFS_V4 */ |
136 | |
137 | static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct rpc_cred *cred) |
138 | { |
139 | struct nfs_open_dir_context *ctx; |
140 | ctx = kmalloc(sizeof(*ctx), GFP_KERNEL); |
141 | if (ctx != NULL) { |
142 | ctx->duped = 0; |
143 | ctx->dir_cookie = 0; |
144 | ctx->dup_cookie = 0; |
145 | ctx->cred = get_rpccred(cred); |
146 | } else |
147 | ctx = ERR_PTR(-ENOMEM); |
148 | return ctx; |
149 | } |
150 | |
151 | static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx) |
152 | { |
153 | put_rpccred(ctx->cred); |
154 | kfree(ctx); |
155 | } |
156 | |
157 | /* |
158 | * Open file |
159 | */ |
160 | static int |
161 | nfs_opendir(struct inode *inode, struct file *filp) |
162 | { |
163 | int res = 0; |
164 | struct nfs_open_dir_context *ctx; |
165 | struct rpc_cred *cred; |
166 | |
167 | dfprintk(FILE, "NFS: open dir(%s/%s)\n", |
168 | filp->f_path.dentry->d_parent->d_name.name, |
169 | filp->f_path.dentry->d_name.name); |
170 | |
171 | nfs_inc_stats(inode, NFSIOS_VFSOPEN); |
172 | |
173 | cred = rpc_lookup_cred(); |
174 | if (IS_ERR(cred)) |
175 | return PTR_ERR(cred); |
176 | ctx = alloc_nfs_open_dir_context(cred); |
177 | if (IS_ERR(ctx)) { |
178 | res = PTR_ERR(ctx); |
179 | goto out; |
180 | } |
181 | filp->private_data = ctx; |
182 | if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) { |
183 | /* This is a mountpoint, so d_revalidate will never |
184 | * have been called, so we need to refresh the |
185 | * inode (for close-open consistency) ourselves. |
186 | */ |
187 | __nfs_revalidate_inode(NFS_SERVER(inode), inode); |
188 | } |
189 | out: |
190 | put_rpccred(cred); |
191 | return res; |
192 | } |
193 | |
194 | static int |
195 | nfs_closedir(struct inode *inode, struct file *filp) |
196 | { |
197 | put_nfs_open_dir_context(filp->private_data); |
198 | return 0; |
199 | } |
200 | |
201 | struct nfs_cache_array_entry { |
202 | u64 cookie; |
203 | u64 ino; |
204 | struct qstr string; |
205 | unsigned char d_type; |
206 | }; |
207 | |
208 | struct nfs_cache_array { |
209 | unsigned int size; |
210 | int eof_index; |
211 | u64 last_cookie; |
212 | struct nfs_cache_array_entry array[0]; |
213 | }; |
214 | |
215 | typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, int); |
216 | typedef struct { |
217 | struct file *file; |
218 | struct page *page; |
219 | unsigned long page_index; |
220 | u64 *dir_cookie; |
221 | u64 last_cookie; |
222 | loff_t current_index; |
223 | decode_dirent_t decode; |
224 | |
225 | unsigned long timestamp; |
226 | unsigned long gencount; |
227 | unsigned int cache_entry_index; |
228 | unsigned int plus:1; |
229 | unsigned int eof:1; |
230 | } nfs_readdir_descriptor_t; |
231 | |
232 | /* |
233 | * The caller is responsible for calling nfs_readdir_release_array(page) |
234 | */ |
235 | static |
236 | struct nfs_cache_array *nfs_readdir_get_array(struct page *page) |
237 | { |
238 | void *ptr; |
239 | if (page == NULL) |
240 | return ERR_PTR(-EIO); |
241 | ptr = kmap(page); |
242 | if (ptr == NULL) |
243 | return ERR_PTR(-ENOMEM); |
244 | return ptr; |
245 | } |
246 | |
247 | static |
248 | void nfs_readdir_release_array(struct page *page) |
249 | { |
250 | kunmap(page); |
251 | } |
252 | |
253 | /* |
254 | * we are freeing strings created by nfs_add_to_readdir_array() |
255 | */ |
256 | static |
257 | void nfs_readdir_clear_array(struct page *page) |
258 | { |
259 | struct nfs_cache_array *array; |
260 | int i; |
261 | |
262 | array = kmap_atomic(page, KM_USER0); |
263 | for (i = 0; i < array->size; i++) |
264 | kfree(array->array[i].string.name); |
265 | kunmap_atomic(array, KM_USER0); |
266 | } |
267 | |
268 | /* |
269 | * the caller is responsible for freeing qstr.name |
270 | * when called by nfs_readdir_add_to_array, the strings will be freed in |
271 | * nfs_clear_readdir_array() |
272 | */ |
273 | static |
274 | int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int len) |
275 | { |
276 | string->len = len; |
277 | string->name = kmemdup(name, len, GFP_KERNEL); |
278 | if (string->name == NULL) |
279 | return -ENOMEM; |
280 | /* |
281 | * Avoid a kmemleak false positive. The pointer to the name is stored |
282 | * in a page cache page which kmemleak does not scan. |
283 | */ |
284 | kmemleak_not_leak(string->name); |
285 | string->hash = full_name_hash(name, len); |
286 | return 0; |
287 | } |
288 | |
289 | static |
290 | int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page) |
291 | { |
292 | struct nfs_cache_array *array = nfs_readdir_get_array(page); |
293 | struct nfs_cache_array_entry *cache_entry; |
294 | int ret; |
295 | |
296 | if (IS_ERR(array)) |
297 | return PTR_ERR(array); |
298 | |
299 | cache_entry = &array->array[array->size]; |
300 | |
301 | /* Check that this entry lies within the page bounds */ |
302 | ret = -ENOSPC; |
303 | if ((char *)&cache_entry[1] - (char *)page_address(page) > PAGE_SIZE) |
304 | goto out; |
305 | |
306 | cache_entry->cookie = entry->prev_cookie; |
307 | cache_entry->ino = entry->ino; |
308 | cache_entry->d_type = entry->d_type; |
309 | ret = nfs_readdir_make_qstr(&cache_entry->string, entry->name, entry->len); |
310 | if (ret) |
311 | goto out; |
312 | array->last_cookie = entry->cookie; |
313 | array->size++; |
314 | if (entry->eof != 0) |
315 | array->eof_index = array->size; |
316 | out: |
317 | nfs_readdir_release_array(page); |
318 | return ret; |
319 | } |
320 | |
321 | static |
322 | int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) |
323 | { |
324 | loff_t diff = desc->file->f_pos - desc->current_index; |
325 | unsigned int index; |
326 | struct nfs_open_dir_context *ctx = desc->file->private_data; |
327 | |
328 | if (diff < 0) |
329 | goto out_eof; |
330 | if (diff >= array->size) { |
331 | if (array->eof_index >= 0) |
332 | goto out_eof; |
333 | return -EAGAIN; |
334 | } |
335 | |
336 | index = (unsigned int)diff; |
337 | *desc->dir_cookie = array->array[index].cookie; |
338 | desc->cache_entry_index = index; |
339 | ctx->duped = 0; |
340 | return 0; |
341 | out_eof: |
342 | desc->eof = 1; |
343 | return -EBADCOOKIE; |
344 | } |
345 | |
346 | static |
347 | int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc) |
348 | { |
349 | int i; |
350 | loff_t new_pos; |
351 | int status = -EAGAIN; |
352 | struct nfs_open_dir_context *ctx = desc->file->private_data; |
353 | |
354 | for (i = 0; i < array->size; i++) { |
355 | if (array->array[i].cookie == *desc->dir_cookie) { |
356 | new_pos = desc->current_index + i; |
357 | if (new_pos < desc->file->f_pos) { |
358 | ctx->dup_cookie = *desc->dir_cookie; |
359 | ctx->duped = 1; |
360 | } |
361 | desc->file->f_pos = new_pos; |
362 | desc->cache_entry_index = i; |
363 | return 0; |
364 | } |
365 | } |
366 | if (array->eof_index >= 0) { |
367 | status = -EBADCOOKIE; |
368 | if (*desc->dir_cookie == array->last_cookie) |
369 | desc->eof = 1; |
370 | } |
371 | return status; |
372 | } |
373 | |
374 | static |
375 | int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc) |
376 | { |
377 | struct nfs_cache_array *array; |
378 | int status; |
379 | |
380 | array = nfs_readdir_get_array(desc->page); |
381 | if (IS_ERR(array)) { |
382 | status = PTR_ERR(array); |
383 | goto out; |
384 | } |
385 | |
386 | if (*desc->dir_cookie == 0) |
387 | status = nfs_readdir_search_for_pos(array, desc); |
388 | else |
389 | status = nfs_readdir_search_for_cookie(array, desc); |
390 | |
391 | if (status == -EAGAIN) { |
392 | desc->last_cookie = array->last_cookie; |
393 | desc->current_index += array->size; |
394 | desc->page_index++; |
395 | } |
396 | nfs_readdir_release_array(desc->page); |
397 | out: |
398 | return status; |
399 | } |
400 | |
401 | /* Fill a page with xdr information before transferring to the cache page */ |
402 | static |
403 | int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc, |
404 | struct nfs_entry *entry, struct file *file, struct inode *inode) |
405 | { |
406 | struct nfs_open_dir_context *ctx = file->private_data; |
407 | struct rpc_cred *cred = ctx->cred; |
408 | unsigned long timestamp, gencount; |
409 | int error; |
410 | |
411 | again: |
412 | timestamp = jiffies; |
413 | gencount = nfs_inc_attr_generation_counter(); |
414 | error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, entry->cookie, pages, |
415 | NFS_SERVER(inode)->dtsize, desc->plus); |
416 | if (error < 0) { |
417 | /* We requested READDIRPLUS, but the server doesn't grok it */ |
418 | if (error == -ENOTSUPP && desc->plus) { |
419 | NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; |
420 | clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); |
421 | desc->plus = 0; |
422 | goto again; |
423 | } |
424 | goto error; |
425 | } |
426 | desc->timestamp = timestamp; |
427 | desc->gencount = gencount; |
428 | error: |
429 | return error; |
430 | } |
431 | |
432 | static int xdr_decode(nfs_readdir_descriptor_t *desc, |
433 | struct nfs_entry *entry, struct xdr_stream *xdr) |
434 | { |
435 | int error; |
436 | |
437 | error = desc->decode(xdr, entry, desc->plus); |
438 | if (error) |
439 | return error; |
440 | entry->fattr->time_start = desc->timestamp; |
441 | entry->fattr->gencount = desc->gencount; |
442 | return 0; |
443 | } |
444 | |
445 | static |
446 | int nfs_same_file(struct dentry *dentry, struct nfs_entry *entry) |
447 | { |
448 | if (dentry->d_inode == NULL) |
449 | goto different; |
450 | if (nfs_compare_fh(entry->fh, NFS_FH(dentry->d_inode)) != 0) |
451 | goto different; |
452 | return 1; |
453 | different: |
454 | return 0; |
455 | } |
456 | |
457 | static |
458 | void nfs_prime_dcache(struct dentry *parent, struct nfs_entry *entry) |
459 | { |
460 | struct qstr filename = { |
461 | .len = entry->len, |
462 | .name = entry->name, |
463 | }; |
464 | struct dentry *dentry; |
465 | struct dentry *alias; |
466 | struct inode *dir = parent->d_inode; |
467 | struct inode *inode; |
468 | |
469 | if (filename.name[0] == '.') { |
470 | if (filename.len == 1) |
471 | return; |
472 | if (filename.len == 2 && filename.name[1] == '.') |
473 | return; |
474 | } |
475 | filename.hash = full_name_hash(filename.name, filename.len); |
476 | |
477 | dentry = d_lookup(parent, &filename); |
478 | if (dentry != NULL) { |
479 | if (nfs_same_file(dentry, entry)) { |
480 | nfs_refresh_inode(dentry->d_inode, entry->fattr); |
481 | goto out; |
482 | } else { |
483 | d_drop(dentry); |
484 | dput(dentry); |
485 | } |
486 | } |
487 | |
488 | dentry = d_alloc(parent, &filename); |
489 | if (dentry == NULL) |
490 | return; |
491 | |
492 | inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); |
493 | if (IS_ERR(inode)) |
494 | goto out; |
495 | |
496 | alias = d_materialise_unique(dentry, inode); |
497 | if (IS_ERR(alias)) |
498 | goto out; |
499 | else if (alias) { |
500 | nfs_set_verifier(alias, nfs_save_change_attribute(dir)); |
501 | dput(alias); |
502 | } else |
503 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
504 | |
505 | out: |
506 | dput(dentry); |
507 | } |
508 | |
509 | /* Perform conversion from xdr to cache array */ |
510 | static |
511 | int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *entry, |
512 | struct page **xdr_pages, struct page *page, unsigned int buflen) |
513 | { |
514 | struct xdr_stream stream; |
515 | struct xdr_buf buf; |
516 | struct page *scratch; |
517 | struct nfs_cache_array *array; |
518 | unsigned int count = 0; |
519 | int status; |
520 | |
521 | scratch = alloc_page(GFP_KERNEL); |
522 | if (scratch == NULL) |
523 | return -ENOMEM; |
524 | |
525 | xdr_init_decode_pages(&stream, &buf, xdr_pages, buflen); |
526 | xdr_set_scratch_buffer(&stream, page_address(scratch), PAGE_SIZE); |
527 | |
528 | do { |
529 | status = xdr_decode(desc, entry, &stream); |
530 | if (status != 0) { |
531 | if (status == -EAGAIN) |
532 | status = 0; |
533 | break; |
534 | } |
535 | |
536 | count++; |
537 | |
538 | if (desc->plus != 0) |
539 | nfs_prime_dcache(desc->file->f_path.dentry, entry); |
540 | |
541 | status = nfs_readdir_add_to_array(entry, page); |
542 | if (status != 0) |
543 | break; |
544 | } while (!entry->eof); |
545 | |
546 | if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) { |
547 | array = nfs_readdir_get_array(page); |
548 | if (!IS_ERR(array)) { |
549 | array->eof_index = array->size; |
550 | status = 0; |
551 | nfs_readdir_release_array(page); |
552 | } else |
553 | status = PTR_ERR(array); |
554 | } |
555 | |
556 | put_page(scratch); |
557 | return status; |
558 | } |
559 | |
560 | static |
561 | void nfs_readdir_free_pagearray(struct page **pages, unsigned int npages) |
562 | { |
563 | unsigned int i; |
564 | for (i = 0; i < npages; i++) |
565 | put_page(pages[i]); |
566 | } |
567 | |
568 | static |
569 | void nfs_readdir_free_large_page(void *ptr, struct page **pages, |
570 | unsigned int npages) |
571 | { |
572 | nfs_readdir_free_pagearray(pages, npages); |
573 | } |
574 | |
575 | /* |
576 | * nfs_readdir_large_page will allocate pages that must be freed with a call |
577 | * to nfs_readdir_free_large_page |
578 | */ |
579 | static |
580 | int nfs_readdir_large_page(struct page **pages, unsigned int npages) |
581 | { |
582 | unsigned int i; |
583 | |
584 | for (i = 0; i < npages; i++) { |
585 | struct page *page = alloc_page(GFP_KERNEL); |
586 | if (page == NULL) |
587 | goto out_freepages; |
588 | pages[i] = page; |
589 | } |
590 | return 0; |
591 | |
592 | out_freepages: |
593 | nfs_readdir_free_pagearray(pages, i); |
594 | return -ENOMEM; |
595 | } |
596 | |
597 | static |
598 | int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page, struct inode *inode) |
599 | { |
600 | struct page *pages[NFS_MAX_READDIR_PAGES]; |
601 | void *pages_ptr = NULL; |
602 | struct nfs_entry entry; |
603 | struct file *file = desc->file; |
604 | struct nfs_cache_array *array; |
605 | int status = -ENOMEM; |
606 | unsigned int array_size = ARRAY_SIZE(pages); |
607 | |
608 | entry.prev_cookie = 0; |
609 | entry.cookie = desc->last_cookie; |
610 | entry.eof = 0; |
611 | entry.fh = nfs_alloc_fhandle(); |
612 | entry.fattr = nfs_alloc_fattr(); |
613 | entry.server = NFS_SERVER(inode); |
614 | if (entry.fh == NULL || entry.fattr == NULL) |
615 | goto out; |
616 | |
617 | array = nfs_readdir_get_array(page); |
618 | if (IS_ERR(array)) { |
619 | status = PTR_ERR(array); |
620 | goto out; |
621 | } |
622 | memset(array, 0, sizeof(struct nfs_cache_array)); |
623 | array->eof_index = -1; |
624 | |
625 | status = nfs_readdir_large_page(pages, array_size); |
626 | if (status < 0) |
627 | goto out_release_array; |
628 | do { |
629 | unsigned int pglen; |
630 | status = nfs_readdir_xdr_filler(pages, desc, &entry, file, inode); |
631 | |
632 | if (status < 0) |
633 | break; |
634 | pglen = status; |
635 | status = nfs_readdir_page_filler(desc, &entry, pages, page, pglen); |
636 | if (status < 0) { |
637 | if (status == -ENOSPC) |
638 | status = 0; |
639 | break; |
640 | } |
641 | } while (array->eof_index < 0); |
642 | |
643 | nfs_readdir_free_large_page(pages_ptr, pages, array_size); |
644 | out_release_array: |
645 | nfs_readdir_release_array(page); |
646 | out: |
647 | nfs_free_fattr(entry.fattr); |
648 | nfs_free_fhandle(entry.fh); |
649 | return status; |
650 | } |
651 | |
652 | /* |
653 | * Now we cache directories properly, by converting xdr information |
654 | * to an array that can be used for lookups later. This results in |
655 | * fewer cache pages, since we can store more information on each page. |
656 | * We only need to convert from xdr once so future lookups are much simpler |
657 | */ |
658 | static |
659 | int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page) |
660 | { |
661 | struct inode *inode = desc->file->f_path.dentry->d_inode; |
662 | int ret; |
663 | |
664 | ret = nfs_readdir_xdr_to_array(desc, page, inode); |
665 | if (ret < 0) |
666 | goto error; |
667 | SetPageUptodate(page); |
668 | |
669 | if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) { |
670 | /* Should never happen */ |
671 | nfs_zap_mapping(inode, inode->i_mapping); |
672 | } |
673 | unlock_page(page); |
674 | return 0; |
675 | error: |
676 | unlock_page(page); |
677 | return ret; |
678 | } |
679 | |
680 | static |
681 | void cache_page_release(nfs_readdir_descriptor_t *desc) |
682 | { |
683 | if (!desc->page->mapping) |
684 | nfs_readdir_clear_array(desc->page); |
685 | page_cache_release(desc->page); |
686 | desc->page = NULL; |
687 | } |
688 | |
689 | static |
690 | struct page *get_cache_page(nfs_readdir_descriptor_t *desc) |
691 | { |
692 | return read_cache_page(desc->file->f_path.dentry->d_inode->i_mapping, |
693 | desc->page_index, (filler_t *)nfs_readdir_filler, desc); |
694 | } |
695 | |
696 | /* |
697 | * Returns 0 if desc->dir_cookie was found on page desc->page_index |
698 | */ |
699 | static |
700 | int find_cache_page(nfs_readdir_descriptor_t *desc) |
701 | { |
702 | int res; |
703 | |
704 | desc->page = get_cache_page(desc); |
705 | if (IS_ERR(desc->page)) |
706 | return PTR_ERR(desc->page); |
707 | |
708 | res = nfs_readdir_search_array(desc); |
709 | if (res != 0) |
710 | cache_page_release(desc); |
711 | return res; |
712 | } |
713 | |
714 | /* Search for desc->dir_cookie from the beginning of the page cache */ |
715 | static inline |
716 | int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) |
717 | { |
718 | int res; |
719 | |
720 | if (desc->page_index == 0) { |
721 | desc->current_index = 0; |
722 | desc->last_cookie = 0; |
723 | } |
724 | do { |
725 | res = find_cache_page(desc); |
726 | } while (res == -EAGAIN); |
727 | return res; |
728 | } |
729 | |
730 | /* |
731 | * Once we've found the start of the dirent within a page: fill 'er up... |
732 | */ |
733 | static |
734 | int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, |
735 | filldir_t filldir) |
736 | { |
737 | struct file *file = desc->file; |
738 | int i = 0; |
739 | int res = 0; |
740 | struct nfs_cache_array *array = NULL; |
741 | struct nfs_open_dir_context *ctx = file->private_data; |
742 | |
743 | if (ctx->duped != 0 && ctx->dup_cookie == *desc->dir_cookie) { |
744 | if (printk_ratelimit()) { |
745 | pr_notice("NFS: directory %s/%s contains a readdir loop. " |
746 | "Please contact your server vendor. " |
747 | "Offending cookie: %llu\n", |
748 | file->f_dentry->d_parent->d_name.name, |
749 | file->f_dentry->d_name.name, |
750 | *desc->dir_cookie); |
751 | } |
752 | res = -ELOOP; |
753 | goto out; |
754 | } |
755 | |
756 | array = nfs_readdir_get_array(desc->page); |
757 | if (IS_ERR(array)) { |
758 | res = PTR_ERR(array); |
759 | goto out; |
760 | } |
761 | |
762 | for (i = desc->cache_entry_index; i < array->size; i++) { |
763 | struct nfs_cache_array_entry *ent; |
764 | |
765 | ent = &array->array[i]; |
766 | if (filldir(dirent, ent->string.name, ent->string.len, |
767 | file->f_pos, nfs_compat_user_ino64(ent->ino), |
768 | ent->d_type) < 0) { |
769 | desc->eof = 1; |
770 | break; |
771 | } |
772 | file->f_pos++; |
773 | if (i < (array->size-1)) |
774 | *desc->dir_cookie = array->array[i+1].cookie; |
775 | else |
776 | *desc->dir_cookie = array->last_cookie; |
777 | } |
778 | if (array->eof_index >= 0) |
779 | desc->eof = 1; |
780 | |
781 | nfs_readdir_release_array(desc->page); |
782 | out: |
783 | cache_page_release(desc); |
784 | dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", |
785 | (unsigned long long)*desc->dir_cookie, res); |
786 | return res; |
787 | } |
788 | |
789 | /* |
790 | * If we cannot find a cookie in our cache, we suspect that this is |
791 | * because it points to a deleted file, so we ask the server to return |
792 | * whatever it thinks is the next entry. We then feed this to filldir. |
793 | * If all goes well, we should then be able to find our way round the |
794 | * cache on the next call to readdir_search_pagecache(); |
795 | * |
796 | * NOTE: we cannot add the anonymous page to the pagecache because |
797 | * the data it contains might not be page aligned. Besides, |
798 | * we should already have a complete representation of the |
799 | * directory in the page cache by the time we get here. |
800 | */ |
801 | static inline |
802 | int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent, |
803 | filldir_t filldir) |
804 | { |
805 | struct page *page = NULL; |
806 | int status; |
807 | struct inode *inode = desc->file->f_path.dentry->d_inode; |
808 | |
809 | dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n", |
810 | (unsigned long long)*desc->dir_cookie); |
811 | |
812 | page = alloc_page(GFP_HIGHUSER); |
813 | if (!page) { |
814 | status = -ENOMEM; |
815 | goto out; |
816 | } |
817 | |
818 | desc->page_index = 0; |
819 | desc->last_cookie = *desc->dir_cookie; |
820 | desc->page = page; |
821 | |
822 | status = nfs_readdir_xdr_to_array(desc, page, inode); |
823 | if (status < 0) |
824 | goto out_release; |
825 | |
826 | status = nfs_do_filldir(desc, dirent, filldir); |
827 | |
828 | out: |
829 | dfprintk(DIRCACHE, "NFS: %s: returns %d\n", |
830 | __func__, status); |
831 | return status; |
832 | out_release: |
833 | cache_page_release(desc); |
834 | goto out; |
835 | } |
836 | |
837 | /* The file offset position represents the dirent entry number. A |
838 | last cookie cache takes care of the common case of reading the |
839 | whole directory. |
840 | */ |
841 | static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir) |
842 | { |
843 | struct dentry *dentry = filp->f_path.dentry; |
844 | struct inode *inode = dentry->d_inode; |
845 | nfs_readdir_descriptor_t my_desc, |
846 | *desc = &my_desc; |
847 | struct nfs_open_dir_context *dir_ctx = filp->private_data; |
848 | int res; |
849 | |
850 | dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n", |
851 | dentry->d_parent->d_name.name, dentry->d_name.name, |
852 | (long long)filp->f_pos); |
853 | nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); |
854 | |
855 | /* |
856 | * filp->f_pos points to the dirent entry number. |
857 | * *desc->dir_cookie has the cookie for the next entry. We have |
858 | * to either find the entry with the appropriate number or |
859 | * revalidate the cookie. |
860 | */ |
861 | memset(desc, 0, sizeof(*desc)); |
862 | |
863 | desc->file = filp; |
864 | desc->dir_cookie = &dir_ctx->dir_cookie; |
865 | desc->decode = NFS_PROTO(inode)->decode_dirent; |
866 | desc->plus = NFS_USE_READDIRPLUS(inode); |
867 | |
868 | nfs_block_sillyrename(dentry); |
869 | res = nfs_revalidate_mapping(inode, filp->f_mapping); |
870 | if (res < 0) |
871 | goto out; |
872 | |
873 | do { |
874 | res = readdir_search_pagecache(desc); |
875 | |
876 | if (res == -EBADCOOKIE) { |
877 | res = 0; |
878 | /* This means either end of directory */ |
879 | if (*desc->dir_cookie && desc->eof == 0) { |
880 | /* Or that the server has 'lost' a cookie */ |
881 | res = uncached_readdir(desc, dirent, filldir); |
882 | if (res == 0) |
883 | continue; |
884 | } |
885 | break; |
886 | } |
887 | if (res == -ETOOSMALL && desc->plus) { |
888 | clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); |
889 | nfs_zap_caches(inode); |
890 | desc->page_index = 0; |
891 | desc->plus = 0; |
892 | desc->eof = 0; |
893 | continue; |
894 | } |
895 | if (res < 0) |
896 | break; |
897 | |
898 | res = nfs_do_filldir(desc, dirent, filldir); |
899 | if (res < 0) |
900 | break; |
901 | } while (!desc->eof); |
902 | out: |
903 | nfs_unblock_sillyrename(dentry); |
904 | if (res > 0) |
905 | res = 0; |
906 | dfprintk(FILE, "NFS: readdir(%s/%s) returns %d\n", |
907 | dentry->d_parent->d_name.name, dentry->d_name.name, |
908 | res); |
909 | return res; |
910 | } |
911 | |
912 | static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin) |
913 | { |
914 | struct dentry *dentry = filp->f_path.dentry; |
915 | struct inode *inode = dentry->d_inode; |
916 | struct nfs_open_dir_context *dir_ctx = filp->private_data; |
917 | |
918 | dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n", |
919 | dentry->d_parent->d_name.name, |
920 | dentry->d_name.name, |
921 | offset, origin); |
922 | |
923 | mutex_lock(&inode->i_mutex); |
924 | switch (origin) { |
925 | case 1: |
926 | offset += filp->f_pos; |
927 | case 0: |
928 | if (offset >= 0) |
929 | break; |
930 | default: |
931 | offset = -EINVAL; |
932 | goto out; |
933 | } |
934 | if (offset != filp->f_pos) { |
935 | filp->f_pos = offset; |
936 | dir_ctx->dir_cookie = 0; |
937 | dir_ctx->duped = 0; |
938 | } |
939 | out: |
940 | mutex_unlock(&inode->i_mutex); |
941 | return offset; |
942 | } |
943 | |
944 | /* |
945 | * All directory operations under NFS are synchronous, so fsync() |
946 | * is a dummy operation. |
947 | */ |
948 | static int nfs_fsync_dir(struct file *filp, int datasync) |
949 | { |
950 | struct dentry *dentry = filp->f_path.dentry; |
951 | |
952 | dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n", |
953 | dentry->d_parent->d_name.name, dentry->d_name.name, |
954 | datasync); |
955 | |
956 | nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC); |
957 | return 0; |
958 | } |
959 | |
960 | /** |
961 | * nfs_force_lookup_revalidate - Mark the directory as having changed |
962 | * @dir - pointer to directory inode |
963 | * |
964 | * This forces the revalidation code in nfs_lookup_revalidate() to do a |
965 | * full lookup on all child dentries of 'dir' whenever a change occurs |
966 | * on the server that might have invalidated our dcache. |
967 | * |
968 | * The caller should be holding dir->i_lock |
969 | */ |
970 | void nfs_force_lookup_revalidate(struct inode *dir) |
971 | { |
972 | NFS_I(dir)->cache_change_attribute++; |
973 | } |
974 | |
975 | /* |
976 | * A check for whether or not the parent directory has changed. |
977 | * In the case it has, we assume that the dentries are untrustworthy |
978 | * and may need to be looked up again. |
979 | */ |
980 | static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) |
981 | { |
982 | if (IS_ROOT(dentry)) |
983 | return 1; |
984 | if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) |
985 | return 0; |
986 | if (!nfs_verify_change_attribute(dir, dentry->d_time)) |
987 | return 0; |
988 | /* Revalidate nfsi->cache_change_attribute before we declare a match */ |
989 | if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) |
990 | return 0; |
991 | if (!nfs_verify_change_attribute(dir, dentry->d_time)) |
992 | return 0; |
993 | return 1; |
994 | } |
995 | |
996 | /* |
997 | * Return the intent data that applies to this particular path component |
998 | * |
999 | * Note that the current set of intents only apply to the very last |
1000 | * component of the path. |
1001 | * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT. |
1002 | */ |
1003 | static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, |
1004 | unsigned int mask) |
1005 | { |
1006 | if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT)) |
1007 | return 0; |
1008 | return nd->flags & mask; |
1009 | } |
1010 | |
1011 | /* |
1012 | * Use intent information to check whether or not we're going to do |
1013 | * an O_EXCL create using this path component. |
1014 | */ |
1015 | static int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd) |
1016 | { |
1017 | if (NFS_PROTO(dir)->version == 2) |
1018 | return 0; |
1019 | return nd && nfs_lookup_check_intent(nd, LOOKUP_EXCL); |
1020 | } |
1021 | |
1022 | /* |
1023 | * Inode and filehandle revalidation for lookups. |
1024 | * |
1025 | * We force revalidation in the cases where the VFS sets LOOKUP_REVAL, |
1026 | * or if the intent information indicates that we're about to open this |
1027 | * particular file and the "nocto" mount flag is not set. |
1028 | * |
1029 | */ |
1030 | static inline |
1031 | int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd) |
1032 | { |
1033 | struct nfs_server *server = NFS_SERVER(inode); |
1034 | |
1035 | if (IS_AUTOMOUNT(inode)) |
1036 | return 0; |
1037 | if (nd != NULL) { |
1038 | /* VFS wants an on-the-wire revalidation */ |
1039 | if (nd->flags & LOOKUP_REVAL) |
1040 | goto out_force; |
1041 | /* This is an open(2) */ |
1042 | if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 && |
1043 | !(server->flags & NFS_MOUNT_NOCTO) && |
1044 | (S_ISREG(inode->i_mode) || |
1045 | S_ISDIR(inode->i_mode))) |
1046 | goto out_force; |
1047 | return 0; |
1048 | } |
1049 | return nfs_revalidate_inode(server, inode); |
1050 | out_force: |
1051 | return __nfs_revalidate_inode(server, inode); |
1052 | } |
1053 | |
1054 | /* |
1055 | * We judge how long we want to trust negative |
1056 | * dentries by looking at the parent inode mtime. |
1057 | * |
1058 | * If parent mtime has changed, we revalidate, else we wait for a |
1059 | * period corresponding to the parent's attribute cache timeout value. |
1060 | */ |
1061 | static inline |
1062 | int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, |
1063 | struct nameidata *nd) |
1064 | { |
1065 | /* Don't revalidate a negative dentry if we're creating a new file */ |
1066 | if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) |
1067 | return 0; |
1068 | if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) |
1069 | return 1; |
1070 | return !nfs_check_verifier(dir, dentry); |
1071 | } |
1072 | |
1073 | /* |
1074 | * This is called every time the dcache has a lookup hit, |
1075 | * and we should check whether we can really trust that |
1076 | * lookup. |
1077 | * |
1078 | * NOTE! The hit can be a negative hit too, don't assume |
1079 | * we have an inode! |
1080 | * |
1081 | * If the parent directory is seen to have changed, we throw out the |
1082 | * cached dentry and do a new lookup. |
1083 | */ |
1084 | static int nfs_lookup_revalidate(struct dentry *dentry, struct nameidata *nd) |
1085 | { |
1086 | struct inode *dir; |
1087 | struct inode *inode; |
1088 | struct dentry *parent; |
1089 | struct nfs_fh *fhandle = NULL; |
1090 | struct nfs_fattr *fattr = NULL; |
1091 | int error; |
1092 | |
1093 | if (nd->flags & LOOKUP_RCU) |
1094 | return -ECHILD; |
1095 | |
1096 | parent = dget_parent(dentry); |
1097 | dir = parent->d_inode; |
1098 | nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); |
1099 | inode = dentry->d_inode; |
1100 | |
1101 | if (!inode) { |
1102 | if (nfs_neg_need_reval(dir, dentry, nd)) |
1103 | goto out_bad; |
1104 | goto out_valid; |
1105 | } |
1106 | |
1107 | if (is_bad_inode(inode)) { |
1108 | dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n", |
1109 | __func__, dentry->d_parent->d_name.name, |
1110 | dentry->d_name.name); |
1111 | goto out_bad; |
1112 | } |
1113 | |
1114 | if (nfs_have_delegation(inode, FMODE_READ)) |
1115 | goto out_set_verifier; |
1116 | |
1117 | /* Force a full look up iff the parent directory has changed */ |
1118 | if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) { |
1119 | if (nfs_lookup_verify_inode(inode, nd)) |
1120 | goto out_zap_parent; |
1121 | goto out_valid; |
1122 | } |
1123 | |
1124 | if (NFS_STALE(inode)) |
1125 | goto out_bad; |
1126 | |
1127 | error = -ENOMEM; |
1128 | fhandle = nfs_alloc_fhandle(); |
1129 | fattr = nfs_alloc_fattr(); |
1130 | if (fhandle == NULL || fattr == NULL) |
1131 | goto out_error; |
1132 | |
1133 | error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); |
1134 | if (error) |
1135 | goto out_bad; |
1136 | if (nfs_compare_fh(NFS_FH(inode), fhandle)) |
1137 | goto out_bad; |
1138 | if ((error = nfs_refresh_inode(inode, fattr)) != 0) |
1139 | goto out_bad; |
1140 | |
1141 | nfs_free_fattr(fattr); |
1142 | nfs_free_fhandle(fhandle); |
1143 | out_set_verifier: |
1144 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1145 | out_valid: |
1146 | dput(parent); |
1147 | dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n", |
1148 | __func__, dentry->d_parent->d_name.name, |
1149 | dentry->d_name.name); |
1150 | return 1; |
1151 | out_zap_parent: |
1152 | nfs_zap_caches(dir); |
1153 | out_bad: |
1154 | nfs_mark_for_revalidate(dir); |
1155 | if (inode && S_ISDIR(inode->i_mode)) { |
1156 | /* Purge readdir caches. */ |
1157 | nfs_zap_caches(inode); |
1158 | /* If we have submounts, don't unhash ! */ |
1159 | if (have_submounts(dentry)) |
1160 | goto out_valid; |
1161 | if (dentry->d_flags & DCACHE_DISCONNECTED) |
1162 | goto out_valid; |
1163 | shrink_dcache_parent(dentry); |
1164 | } |
1165 | d_drop(dentry); |
1166 | nfs_free_fattr(fattr); |
1167 | nfs_free_fhandle(fhandle); |
1168 | dput(parent); |
1169 | dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", |
1170 | __func__, dentry->d_parent->d_name.name, |
1171 | dentry->d_name.name); |
1172 | return 0; |
1173 | out_error: |
1174 | nfs_free_fattr(fattr); |
1175 | nfs_free_fhandle(fhandle); |
1176 | dput(parent); |
1177 | dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) lookup returned error %d\n", |
1178 | __func__, dentry->d_parent->d_name.name, |
1179 | dentry->d_name.name, error); |
1180 | return error; |
1181 | } |
1182 | |
1183 | /* |
1184 | * This is called from dput() when d_count is going to 0. |
1185 | */ |
1186 | static int nfs_dentry_delete(const struct dentry *dentry) |
1187 | { |
1188 | dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", |
1189 | dentry->d_parent->d_name.name, dentry->d_name.name, |
1190 | dentry->d_flags); |
1191 | |
1192 | /* Unhash any dentry with a stale inode */ |
1193 | if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode)) |
1194 | return 1; |
1195 | |
1196 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
1197 | /* Unhash it, so that ->d_iput() would be called */ |
1198 | return 1; |
1199 | } |
1200 | if (!(dentry->d_sb->s_flags & MS_ACTIVE)) { |
1201 | /* Unhash it, so that ancestors of killed async unlink |
1202 | * files will be cleaned up during umount */ |
1203 | return 1; |
1204 | } |
1205 | return 0; |
1206 | |
1207 | } |
1208 | |
1209 | static void nfs_drop_nlink(struct inode *inode) |
1210 | { |
1211 | spin_lock(&inode->i_lock); |
1212 | if (inode->i_nlink > 0) |
1213 | drop_nlink(inode); |
1214 | spin_unlock(&inode->i_lock); |
1215 | } |
1216 | |
1217 | /* |
1218 | * Called when the dentry loses inode. |
1219 | * We use it to clean up silly-renamed files. |
1220 | */ |
1221 | static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) |
1222 | { |
1223 | if (S_ISDIR(inode->i_mode)) |
1224 | /* drop any readdir cache as it could easily be old */ |
1225 | NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA; |
1226 | |
1227 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
1228 | drop_nlink(inode); |
1229 | nfs_complete_unlink(dentry, inode); |
1230 | } |
1231 | iput(inode); |
1232 | } |
1233 | |
1234 | static void nfs_d_release(struct dentry *dentry) |
1235 | { |
1236 | /* free cached devname value, if it survived that far */ |
1237 | if (unlikely(dentry->d_fsdata)) { |
1238 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) |
1239 | WARN_ON(1); |
1240 | else |
1241 | kfree(dentry->d_fsdata); |
1242 | } |
1243 | } |
1244 | |
1245 | const struct dentry_operations nfs_dentry_operations = { |
1246 | .d_revalidate = nfs_lookup_revalidate, |
1247 | .d_delete = nfs_dentry_delete, |
1248 | .d_iput = nfs_dentry_iput, |
1249 | .d_automount = nfs_d_automount, |
1250 | .d_release = nfs_d_release, |
1251 | }; |
1252 | |
1253 | static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) |
1254 | { |
1255 | struct dentry *res; |
1256 | struct dentry *parent; |
1257 | struct inode *inode = NULL; |
1258 | struct nfs_fh *fhandle = NULL; |
1259 | struct nfs_fattr *fattr = NULL; |
1260 | int error; |
1261 | |
1262 | dfprintk(VFS, "NFS: lookup(%s/%s)\n", |
1263 | dentry->d_parent->d_name.name, dentry->d_name.name); |
1264 | nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); |
1265 | |
1266 | res = ERR_PTR(-ENAMETOOLONG); |
1267 | if (dentry->d_name.len > NFS_SERVER(dir)->namelen) |
1268 | goto out; |
1269 | |
1270 | /* |
1271 | * If we're doing an exclusive create, optimize away the lookup |
1272 | * but don't hash the dentry. |
1273 | */ |
1274 | if (nfs_is_exclusive_create(dir, nd)) { |
1275 | d_instantiate(dentry, NULL); |
1276 | res = NULL; |
1277 | goto out; |
1278 | } |
1279 | |
1280 | res = ERR_PTR(-ENOMEM); |
1281 | fhandle = nfs_alloc_fhandle(); |
1282 | fattr = nfs_alloc_fattr(); |
1283 | if (fhandle == NULL || fattr == NULL) |
1284 | goto out; |
1285 | |
1286 | parent = dentry->d_parent; |
1287 | /* Protect against concurrent sillydeletes */ |
1288 | nfs_block_sillyrename(parent); |
1289 | error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); |
1290 | if (error == -ENOENT) |
1291 | goto no_entry; |
1292 | if (error < 0) { |
1293 | res = ERR_PTR(error); |
1294 | goto out_unblock_sillyrename; |
1295 | } |
1296 | inode = nfs_fhget(dentry->d_sb, fhandle, fattr); |
1297 | res = ERR_CAST(inode); |
1298 | if (IS_ERR(res)) |
1299 | goto out_unblock_sillyrename; |
1300 | |
1301 | no_entry: |
1302 | res = d_materialise_unique(dentry, inode); |
1303 | if (res != NULL) { |
1304 | if (IS_ERR(res)) |
1305 | goto out_unblock_sillyrename; |
1306 | dentry = res; |
1307 | } |
1308 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1309 | out_unblock_sillyrename: |
1310 | nfs_unblock_sillyrename(parent); |
1311 | out: |
1312 | nfs_free_fattr(fattr); |
1313 | nfs_free_fhandle(fhandle); |
1314 | return res; |
1315 | } |
1316 | |
1317 | #ifdef CONFIG_NFS_V4 |
1318 | static int nfs_open_revalidate(struct dentry *, struct nameidata *); |
1319 | |
1320 | const struct dentry_operations nfs4_dentry_operations = { |
1321 | .d_revalidate = nfs_open_revalidate, |
1322 | .d_delete = nfs_dentry_delete, |
1323 | .d_iput = nfs_dentry_iput, |
1324 | .d_automount = nfs_d_automount, |
1325 | .d_release = nfs_d_release, |
1326 | }; |
1327 | |
1328 | /* |
1329 | * Use intent information to determine whether we need to substitute |
1330 | * the NFSv4-style stateful OPEN for the LOOKUP call |
1331 | */ |
1332 | static int is_atomic_open(struct nameidata *nd) |
1333 | { |
1334 | if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0) |
1335 | return 0; |
1336 | /* NFS does not (yet) have a stateful open for directories */ |
1337 | if (nd->flags & LOOKUP_DIRECTORY) |
1338 | return 0; |
1339 | /* Are we trying to write to a read only partition? */ |
1340 | if (__mnt_is_readonly(nd->path.mnt) && |
1341 | (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE))) |
1342 | return 0; |
1343 | return 1; |
1344 | } |
1345 | |
1346 | static struct nfs_open_context *nameidata_to_nfs_open_context(struct dentry *dentry, struct nameidata *nd) |
1347 | { |
1348 | struct path path = { |
1349 | .mnt = nd->path.mnt, |
1350 | .dentry = dentry, |
1351 | }; |
1352 | struct nfs_open_context *ctx; |
1353 | struct rpc_cred *cred; |
1354 | fmode_t fmode = nd->intent.open.flags & (FMODE_READ | FMODE_WRITE | FMODE_EXEC); |
1355 | |
1356 | cred = rpc_lookup_cred(); |
1357 | if (IS_ERR(cred)) |
1358 | return ERR_CAST(cred); |
1359 | ctx = alloc_nfs_open_context(&path, cred, fmode); |
1360 | put_rpccred(cred); |
1361 | if (ctx == NULL) |
1362 | return ERR_PTR(-ENOMEM); |
1363 | return ctx; |
1364 | } |
1365 | |
1366 | static int do_open(struct inode *inode, struct file *filp) |
1367 | { |
1368 | nfs_fscache_set_inode_cookie(inode, filp); |
1369 | return 0; |
1370 | } |
1371 | |
1372 | static int nfs_intent_set_file(struct nameidata *nd, struct nfs_open_context *ctx) |
1373 | { |
1374 | struct file *filp; |
1375 | int ret = 0; |
1376 | |
1377 | /* If the open_intent is for execute, we have an extra check to make */ |
1378 | if (ctx->mode & FMODE_EXEC) { |
1379 | ret = nfs_may_open(ctx->path.dentry->d_inode, |
1380 | ctx->cred, |
1381 | nd->intent.open.flags); |
1382 | if (ret < 0) |
1383 | goto out; |
1384 | } |
1385 | filp = lookup_instantiate_filp(nd, ctx->path.dentry, do_open); |
1386 | if (IS_ERR(filp)) |
1387 | ret = PTR_ERR(filp); |
1388 | else |
1389 | nfs_file_set_open_context(filp, ctx); |
1390 | out: |
1391 | put_nfs_open_context(ctx); |
1392 | return ret; |
1393 | } |
1394 | |
1395 | static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) |
1396 | { |
1397 | struct nfs_open_context *ctx; |
1398 | struct iattr attr; |
1399 | struct dentry *res = NULL; |
1400 | struct inode *inode; |
1401 | int open_flags; |
1402 | int err; |
1403 | |
1404 | dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n", |
1405 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1406 | |
1407 | /* Check that we are indeed trying to open this file */ |
1408 | if (!is_atomic_open(nd)) |
1409 | goto no_open; |
1410 | |
1411 | if (dentry->d_name.len > NFS_SERVER(dir)->namelen) { |
1412 | res = ERR_PTR(-ENAMETOOLONG); |
1413 | goto out; |
1414 | } |
1415 | |
1416 | /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash |
1417 | * the dentry. */ |
1418 | if (nd->flags & LOOKUP_EXCL) { |
1419 | d_instantiate(dentry, NULL); |
1420 | goto out; |
1421 | } |
1422 | |
1423 | ctx = nameidata_to_nfs_open_context(dentry, nd); |
1424 | res = ERR_CAST(ctx); |
1425 | if (IS_ERR(ctx)) |
1426 | goto out; |
1427 | |
1428 | open_flags = nd->intent.open.flags; |
1429 | if (nd->flags & LOOKUP_CREATE) { |
1430 | attr.ia_mode = nd->intent.open.create_mode; |
1431 | attr.ia_valid = ATTR_MODE; |
1432 | attr.ia_mode &= ~current_umask(); |
1433 | } else { |
1434 | open_flags &= ~(O_EXCL | O_CREAT); |
1435 | attr.ia_valid = 0; |
1436 | } |
1437 | |
1438 | /* Open the file on the server */ |
1439 | nfs_block_sillyrename(dentry->d_parent); |
1440 | inode = NFS_PROTO(dir)->open_context(dir, ctx, open_flags, &attr); |
1441 | if (IS_ERR(inode)) { |
1442 | nfs_unblock_sillyrename(dentry->d_parent); |
1443 | put_nfs_open_context(ctx); |
1444 | switch (PTR_ERR(inode)) { |
1445 | /* Make a negative dentry */ |
1446 | case -ENOENT: |
1447 | d_add(dentry, NULL); |
1448 | res = NULL; |
1449 | goto out; |
1450 | /* This turned out not to be a regular file */ |
1451 | case -ENOTDIR: |
1452 | goto no_open; |
1453 | case -ELOOP: |
1454 | if (!(nd->intent.open.flags & O_NOFOLLOW)) |
1455 | goto no_open; |
1456 | /* case -EISDIR: */ |
1457 | /* case -EINVAL: */ |
1458 | default: |
1459 | res = ERR_CAST(inode); |
1460 | goto out; |
1461 | } |
1462 | } |
1463 | res = d_add_unique(dentry, inode); |
1464 | nfs_unblock_sillyrename(dentry->d_parent); |
1465 | if (res != NULL) { |
1466 | dput(ctx->path.dentry); |
1467 | ctx->path.dentry = dget(res); |
1468 | dentry = res; |
1469 | } |
1470 | err = nfs_intent_set_file(nd, ctx); |
1471 | if (err < 0) { |
1472 | if (res != NULL) |
1473 | dput(res); |
1474 | return ERR_PTR(err); |
1475 | } |
1476 | out: |
1477 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1478 | return res; |
1479 | no_open: |
1480 | return nfs_lookup(dir, dentry, nd); |
1481 | } |
1482 | |
1483 | static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) |
1484 | { |
1485 | struct dentry *parent = NULL; |
1486 | struct inode *inode; |
1487 | struct inode *dir; |
1488 | struct nfs_open_context *ctx; |
1489 | int openflags, ret = 0; |
1490 | |
1491 | if (nd->flags & LOOKUP_RCU) |
1492 | return -ECHILD; |
1493 | |
1494 | inode = dentry->d_inode; |
1495 | if (!is_atomic_open(nd) || d_mountpoint(dentry)) |
1496 | goto no_open; |
1497 | |
1498 | parent = dget_parent(dentry); |
1499 | dir = parent->d_inode; |
1500 | |
1501 | /* We can't create new files in nfs_open_revalidate(), so we |
1502 | * optimize away revalidation of negative dentries. |
1503 | */ |
1504 | if (inode == NULL) { |
1505 | if (!nfs_neg_need_reval(dir, dentry, nd)) |
1506 | ret = 1; |
1507 | goto out; |
1508 | } |
1509 | |
1510 | /* NFS only supports OPEN on regular files */ |
1511 | if (!S_ISREG(inode->i_mode)) |
1512 | goto no_open_dput; |
1513 | openflags = nd->intent.open.flags; |
1514 | /* We cannot do exclusive creation on a positive dentry */ |
1515 | if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) |
1516 | goto no_open_dput; |
1517 | /* We can't create new files, or truncate existing ones here */ |
1518 | openflags &= ~(O_CREAT|O_EXCL|O_TRUNC); |
1519 | |
1520 | ctx = nameidata_to_nfs_open_context(dentry, nd); |
1521 | ret = PTR_ERR(ctx); |
1522 | if (IS_ERR(ctx)) |
1523 | goto out; |
1524 | /* |
1525 | * Note: we're not holding inode->i_mutex and so may be racing with |
1526 | * operations that change the directory. We therefore save the |
1527 | * change attribute *before* we do the RPC call. |
1528 | */ |
1529 | inode = NFS_PROTO(dir)->open_context(dir, ctx, openflags, NULL); |
1530 | if (IS_ERR(inode)) { |
1531 | ret = PTR_ERR(inode); |
1532 | switch (ret) { |
1533 | case -EPERM: |
1534 | case -EACCES: |
1535 | case -EDQUOT: |
1536 | case -ENOSPC: |
1537 | case -EROFS: |
1538 | goto out_put_ctx; |
1539 | default: |
1540 | goto out_drop; |
1541 | } |
1542 | } |
1543 | iput(inode); |
1544 | if (inode != dentry->d_inode) |
1545 | goto out_drop; |
1546 | |
1547 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1548 | ret = nfs_intent_set_file(nd, ctx); |
1549 | if (ret >= 0) |
1550 | ret = 1; |
1551 | out: |
1552 | dput(parent); |
1553 | return ret; |
1554 | out_drop: |
1555 | d_drop(dentry); |
1556 | ret = 0; |
1557 | out_put_ctx: |
1558 | put_nfs_open_context(ctx); |
1559 | goto out; |
1560 | |
1561 | no_open_dput: |
1562 | dput(parent); |
1563 | no_open: |
1564 | return nfs_lookup_revalidate(dentry, nd); |
1565 | } |
1566 | |
1567 | static int nfs_open_create(struct inode *dir, struct dentry *dentry, int mode, |
1568 | struct nameidata *nd) |
1569 | { |
1570 | struct nfs_open_context *ctx = NULL; |
1571 | struct iattr attr; |
1572 | int error; |
1573 | int open_flags = 0; |
1574 | |
1575 | dfprintk(VFS, "NFS: create(%s/%ld), %s\n", |
1576 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1577 | |
1578 | attr.ia_mode = mode; |
1579 | attr.ia_valid = ATTR_MODE; |
1580 | |
1581 | if ((nd->flags & LOOKUP_CREATE) != 0) { |
1582 | open_flags = nd->intent.open.flags; |
1583 | |
1584 | ctx = nameidata_to_nfs_open_context(dentry, nd); |
1585 | error = PTR_ERR(ctx); |
1586 | if (IS_ERR(ctx)) |
1587 | goto out_err_drop; |
1588 | } |
1589 | |
1590 | error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, ctx); |
1591 | if (error != 0) |
1592 | goto out_put_ctx; |
1593 | if (ctx != NULL) { |
1594 | error = nfs_intent_set_file(nd, ctx); |
1595 | if (error < 0) |
1596 | goto out_err; |
1597 | } |
1598 | return 0; |
1599 | out_put_ctx: |
1600 | if (ctx != NULL) |
1601 | put_nfs_open_context(ctx); |
1602 | out_err_drop: |
1603 | d_drop(dentry); |
1604 | out_err: |
1605 | return error; |
1606 | } |
1607 | |
1608 | #endif /* CONFIG_NFSV4 */ |
1609 | |
1610 | /* |
1611 | * Code common to create, mkdir, and mknod. |
1612 | */ |
1613 | int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, |
1614 | struct nfs_fattr *fattr) |
1615 | { |
1616 | struct dentry *parent = dget_parent(dentry); |
1617 | struct inode *dir = parent->d_inode; |
1618 | struct inode *inode; |
1619 | int error = -EACCES; |
1620 | |
1621 | d_drop(dentry); |
1622 | |
1623 | /* We may have been initialized further down */ |
1624 | if (dentry->d_inode) |
1625 | goto out; |
1626 | if (fhandle->size == 0) { |
1627 | error = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, &dentry->d_name, fhandle, fattr); |
1628 | if (error) |
1629 | goto out_error; |
1630 | } |
1631 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1632 | if (!(fattr->valid & NFS_ATTR_FATTR)) { |
1633 | struct nfs_server *server = NFS_SB(dentry->d_sb); |
1634 | error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr); |
1635 | if (error < 0) |
1636 | goto out_error; |
1637 | } |
1638 | inode = nfs_fhget(dentry->d_sb, fhandle, fattr); |
1639 | error = PTR_ERR(inode); |
1640 | if (IS_ERR(inode)) |
1641 | goto out_error; |
1642 | d_add(dentry, inode); |
1643 | out: |
1644 | dput(parent); |
1645 | return 0; |
1646 | out_error: |
1647 | nfs_mark_for_revalidate(dir); |
1648 | dput(parent); |
1649 | return error; |
1650 | } |
1651 | |
1652 | /* |
1653 | * Following a failed create operation, we drop the dentry rather |
1654 | * than retain a negative dentry. This avoids a problem in the event |
1655 | * that the operation succeeded on the server, but an error in the |
1656 | * reply path made it appear to have failed. |
1657 | */ |
1658 | static int nfs_create(struct inode *dir, struct dentry *dentry, int mode, |
1659 | struct nameidata *nd) |
1660 | { |
1661 | struct iattr attr; |
1662 | int error; |
1663 | int open_flags = 0; |
1664 | |
1665 | dfprintk(VFS, "NFS: create(%s/%ld), %s\n", |
1666 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1667 | |
1668 | attr.ia_mode = mode; |
1669 | attr.ia_valid = ATTR_MODE; |
1670 | |
1671 | if ((nd->flags & LOOKUP_CREATE) != 0) |
1672 | open_flags = nd->intent.open.flags; |
1673 | |
1674 | error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, NULL); |
1675 | if (error != 0) |
1676 | goto out_err; |
1677 | return 0; |
1678 | out_err: |
1679 | d_drop(dentry); |
1680 | return error; |
1681 | } |
1682 | |
1683 | /* |
1684 | * See comments for nfs_proc_create regarding failed operations. |
1685 | */ |
1686 | static int |
1687 | nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev) |
1688 | { |
1689 | struct iattr attr; |
1690 | int status; |
1691 | |
1692 | dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n", |
1693 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1694 | |
1695 | if (!new_valid_dev(rdev)) |
1696 | return -EINVAL; |
1697 | |
1698 | attr.ia_mode = mode; |
1699 | attr.ia_valid = ATTR_MODE; |
1700 | |
1701 | status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); |
1702 | if (status != 0) |
1703 | goto out_err; |
1704 | return 0; |
1705 | out_err: |
1706 | d_drop(dentry); |
1707 | return status; |
1708 | } |
1709 | |
1710 | /* |
1711 | * See comments for nfs_proc_create regarding failed operations. |
1712 | */ |
1713 | static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) |
1714 | { |
1715 | struct iattr attr; |
1716 | int error; |
1717 | |
1718 | dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n", |
1719 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1720 | |
1721 | attr.ia_valid = ATTR_MODE; |
1722 | attr.ia_mode = mode | S_IFDIR; |
1723 | |
1724 | error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); |
1725 | if (error != 0) |
1726 | goto out_err; |
1727 | return 0; |
1728 | out_err: |
1729 | d_drop(dentry); |
1730 | return error; |
1731 | } |
1732 | |
1733 | static void nfs_dentry_handle_enoent(struct dentry *dentry) |
1734 | { |
1735 | if (dentry->d_inode != NULL && !d_unhashed(dentry)) |
1736 | d_delete(dentry); |
1737 | } |
1738 | |
1739 | static int nfs_rmdir(struct inode *dir, struct dentry *dentry) |
1740 | { |
1741 | int error; |
1742 | |
1743 | dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n", |
1744 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1745 | |
1746 | error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); |
1747 | /* Ensure the VFS deletes this inode */ |
1748 | if (error == 0 && dentry->d_inode != NULL) |
1749 | clear_nlink(dentry->d_inode); |
1750 | else if (error == -ENOENT) |
1751 | nfs_dentry_handle_enoent(dentry); |
1752 | |
1753 | return error; |
1754 | } |
1755 | |
1756 | /* |
1757 | * Remove a file after making sure there are no pending writes, |
1758 | * and after checking that the file has only one user. |
1759 | * |
1760 | * We invalidate the attribute cache and free the inode prior to the operation |
1761 | * to avoid possible races if the server reuses the inode. |
1762 | */ |
1763 | static int nfs_safe_remove(struct dentry *dentry) |
1764 | { |
1765 | struct inode *dir = dentry->d_parent->d_inode; |
1766 | struct inode *inode = dentry->d_inode; |
1767 | int error = -EBUSY; |
1768 | |
1769 | dfprintk(VFS, "NFS: safe_remove(%s/%s)\n", |
1770 | dentry->d_parent->d_name.name, dentry->d_name.name); |
1771 | |
1772 | /* If the dentry was sillyrenamed, we simply call d_delete() */ |
1773 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
1774 | error = 0; |
1775 | goto out; |
1776 | } |
1777 | |
1778 | if (inode != NULL) { |
1779 | nfs_inode_return_delegation(inode); |
1780 | error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); |
1781 | /* The VFS may want to delete this inode */ |
1782 | if (error == 0) |
1783 | nfs_drop_nlink(inode); |
1784 | nfs_mark_for_revalidate(inode); |
1785 | } else |
1786 | error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); |
1787 | if (error == -ENOENT) |
1788 | nfs_dentry_handle_enoent(dentry); |
1789 | out: |
1790 | return error; |
1791 | } |
1792 | |
1793 | /* We do silly rename. In case sillyrename() returns -EBUSY, the inode |
1794 | * belongs to an active ".nfs..." file and we return -EBUSY. |
1795 | * |
1796 | * If sillyrename() returns 0, we do nothing, otherwise we unlink. |
1797 | */ |
1798 | static int nfs_unlink(struct inode *dir, struct dentry *dentry) |
1799 | { |
1800 | int error; |
1801 | int need_rehash = 0; |
1802 | |
1803 | dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, |
1804 | dir->i_ino, dentry->d_name.name); |
1805 | |
1806 | spin_lock(&dentry->d_lock); |
1807 | if (dentry->d_count > 1) { |
1808 | spin_unlock(&dentry->d_lock); |
1809 | /* Start asynchronous writeout of the inode */ |
1810 | write_inode_now(dentry->d_inode, 0); |
1811 | error = nfs_sillyrename(dir, dentry); |
1812 | return error; |
1813 | } |
1814 | if (!d_unhashed(dentry)) { |
1815 | __d_drop(dentry); |
1816 | need_rehash = 1; |
1817 | } |
1818 | spin_unlock(&dentry->d_lock); |
1819 | error = nfs_safe_remove(dentry); |
1820 | if (!error || error == -ENOENT) { |
1821 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1822 | } else if (need_rehash) |
1823 | d_rehash(dentry); |
1824 | return error; |
1825 | } |
1826 | |
1827 | /* |
1828 | * To create a symbolic link, most file systems instantiate a new inode, |
1829 | * add a page to it containing the path, then write it out to the disk |
1830 | * using prepare_write/commit_write. |
1831 | * |
1832 | * Unfortunately the NFS client can't create the in-core inode first |
1833 | * because it needs a file handle to create an in-core inode (see |
1834 | * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the |
1835 | * symlink request has completed on the server. |
1836 | * |
1837 | * So instead we allocate a raw page, copy the symname into it, then do |
1838 | * the SYMLINK request with the page as the buffer. If it succeeds, we |
1839 | * now have a new file handle and can instantiate an in-core NFS inode |
1840 | * and move the raw page into its mapping. |
1841 | */ |
1842 | static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
1843 | { |
1844 | struct pagevec lru_pvec; |
1845 | struct page *page; |
1846 | char *kaddr; |
1847 | struct iattr attr; |
1848 | unsigned int pathlen = strlen(symname); |
1849 | int error; |
1850 | |
1851 | dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id, |
1852 | dir->i_ino, dentry->d_name.name, symname); |
1853 | |
1854 | if (pathlen > PAGE_SIZE) |
1855 | return -ENAMETOOLONG; |
1856 | |
1857 | attr.ia_mode = S_IFLNK | S_IRWXUGO; |
1858 | attr.ia_valid = ATTR_MODE; |
1859 | |
1860 | page = alloc_page(GFP_HIGHUSER); |
1861 | if (!page) |
1862 | return -ENOMEM; |
1863 | |
1864 | kaddr = kmap_atomic(page, KM_USER0); |
1865 | memcpy(kaddr, symname, pathlen); |
1866 | if (pathlen < PAGE_SIZE) |
1867 | memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); |
1868 | kunmap_atomic(kaddr, KM_USER0); |
1869 | |
1870 | error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); |
1871 | if (error != 0) { |
1872 | dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n", |
1873 | dir->i_sb->s_id, dir->i_ino, |
1874 | dentry->d_name.name, symname, error); |
1875 | d_drop(dentry); |
1876 | __free_page(page); |
1877 | return error; |
1878 | } |
1879 | |
1880 | /* |
1881 | * No big deal if we can't add this page to the page cache here. |
1882 | * READLINK will get the missing page from the server if needed. |
1883 | */ |
1884 | pagevec_init(&lru_pvec, 0); |
1885 | if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0, |
1886 | GFP_KERNEL)) { |
1887 | pagevec_add(&lru_pvec, page); |
1888 | pagevec_lru_add_file(&lru_pvec); |
1889 | SetPageUptodate(page); |
1890 | unlock_page(page); |
1891 | } else |
1892 | __free_page(page); |
1893 | |
1894 | return 0; |
1895 | } |
1896 | |
1897 | static int |
1898 | nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
1899 | { |
1900 | struct inode *inode = old_dentry->d_inode; |
1901 | int error; |
1902 | |
1903 | dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n", |
1904 | old_dentry->d_parent->d_name.name, old_dentry->d_name.name, |
1905 | dentry->d_parent->d_name.name, dentry->d_name.name); |
1906 | |
1907 | nfs_inode_return_delegation(inode); |
1908 | |
1909 | d_drop(dentry); |
1910 | error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); |
1911 | if (error == 0) { |
1912 | ihold(inode); |
1913 | d_add(dentry, inode); |
1914 | } |
1915 | return error; |
1916 | } |
1917 | |
1918 | /* |
1919 | * RENAME |
1920 | * FIXME: Some nfsds, like the Linux user space nfsd, may generate a |
1921 | * different file handle for the same inode after a rename (e.g. when |
1922 | * moving to a different directory). A fail-safe method to do so would |
1923 | * be to look up old_dir/old_name, create a link to new_dir/new_name and |
1924 | * rename the old file using the sillyrename stuff. This way, the original |
1925 | * file in old_dir will go away when the last process iput()s the inode. |
1926 | * |
1927 | * FIXED. |
1928 | * |
1929 | * It actually works quite well. One needs to have the possibility for |
1930 | * at least one ".nfs..." file in each directory the file ever gets |
1931 | * moved or linked to which happens automagically with the new |
1932 | * implementation that only depends on the dcache stuff instead of |
1933 | * using the inode layer |
1934 | * |
1935 | * Unfortunately, things are a little more complicated than indicated |
1936 | * above. For a cross-directory move, we want to make sure we can get |
1937 | * rid of the old inode after the operation. This means there must be |
1938 | * no pending writes (if it's a file), and the use count must be 1. |
1939 | * If these conditions are met, we can drop the dentries before doing |
1940 | * the rename. |
1941 | */ |
1942 | static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, |
1943 | struct inode *new_dir, struct dentry *new_dentry) |
1944 | { |
1945 | struct inode *old_inode = old_dentry->d_inode; |
1946 | struct inode *new_inode = new_dentry->d_inode; |
1947 | struct dentry *dentry = NULL, *rehash = NULL; |
1948 | int error = -EBUSY; |
1949 | |
1950 | dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", |
1951 | old_dentry->d_parent->d_name.name, old_dentry->d_name.name, |
1952 | new_dentry->d_parent->d_name.name, new_dentry->d_name.name, |
1953 | new_dentry->d_count); |
1954 | |
1955 | /* |
1956 | * For non-directories, check whether the target is busy and if so, |
1957 | * make a copy of the dentry and then do a silly-rename. If the |
1958 | * silly-rename succeeds, the copied dentry is hashed and becomes |
1959 | * the new target. |
1960 | */ |
1961 | if (new_inode && !S_ISDIR(new_inode->i_mode)) { |
1962 | /* |
1963 | * To prevent any new references to the target during the |
1964 | * rename, we unhash the dentry in advance. |
1965 | */ |
1966 | if (!d_unhashed(new_dentry)) { |
1967 | d_drop(new_dentry); |
1968 | rehash = new_dentry; |
1969 | } |
1970 | |
1971 | if (new_dentry->d_count > 2) { |
1972 | int err; |
1973 | |
1974 | /* copy the target dentry's name */ |
1975 | dentry = d_alloc(new_dentry->d_parent, |
1976 | &new_dentry->d_name); |
1977 | if (!dentry) |
1978 | goto out; |
1979 | |
1980 | /* silly-rename the existing target ... */ |
1981 | err = nfs_sillyrename(new_dir, new_dentry); |
1982 | if (err) |
1983 | goto out; |
1984 | |
1985 | new_dentry = dentry; |
1986 | rehash = NULL; |
1987 | new_inode = NULL; |
1988 | } |
1989 | } |
1990 | |
1991 | nfs_inode_return_delegation(old_inode); |
1992 | if (new_inode != NULL) |
1993 | nfs_inode_return_delegation(new_inode); |
1994 | |
1995 | error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name, |
1996 | new_dir, &new_dentry->d_name); |
1997 | nfs_mark_for_revalidate(old_inode); |
1998 | out: |
1999 | if (rehash) |
2000 | d_rehash(rehash); |
2001 | if (!error) { |
2002 | if (new_inode != NULL) |
2003 | nfs_drop_nlink(new_inode); |
2004 | d_move(old_dentry, new_dentry); |
2005 | nfs_set_verifier(new_dentry, |
2006 | nfs_save_change_attribute(new_dir)); |
2007 | } else if (error == -ENOENT) |
2008 | nfs_dentry_handle_enoent(old_dentry); |
2009 | |
2010 | /* new dentry created? */ |
2011 | if (dentry) |
2012 | dput(dentry); |
2013 | return error; |
2014 | } |
2015 | |
2016 | static DEFINE_SPINLOCK(nfs_access_lru_lock); |
2017 | static LIST_HEAD(nfs_access_lru_list); |
2018 | static atomic_long_t nfs_access_nr_entries; |
2019 | |
2020 | static void nfs_access_free_entry(struct nfs_access_entry *entry) |
2021 | { |
2022 | put_rpccred(entry->cred); |
2023 | kfree(entry); |
2024 | smp_mb__before_atomic_dec(); |
2025 | atomic_long_dec(&nfs_access_nr_entries); |
2026 | smp_mb__after_atomic_dec(); |
2027 | } |
2028 | |
2029 | static void nfs_access_free_list(struct list_head *head) |
2030 | { |
2031 | struct nfs_access_entry *cache; |
2032 | |
2033 | while (!list_empty(head)) { |
2034 | cache = list_entry(head->next, struct nfs_access_entry, lru); |
2035 | list_del(&cache->lru); |
2036 | nfs_access_free_entry(cache); |
2037 | } |
2038 | } |
2039 | |
2040 | int nfs_access_cache_shrinker(struct shrinker *shrink, |
2041 | struct shrink_control *sc) |
2042 | { |
2043 | LIST_HEAD(head); |
2044 | struct nfs_inode *nfsi, *next; |
2045 | struct nfs_access_entry *cache; |
2046 | int nr_to_scan = sc->nr_to_scan; |
2047 | gfp_t gfp_mask = sc->gfp_mask; |
2048 | |
2049 | if ((gfp_mask & GFP_KERNEL) != GFP_KERNEL) |
2050 | return (nr_to_scan == 0) ? 0 : -1; |
2051 | |
2052 | spin_lock(&nfs_access_lru_lock); |
2053 | list_for_each_entry_safe(nfsi, next, &nfs_access_lru_list, access_cache_inode_lru) { |
2054 | struct inode *inode; |
2055 | |
2056 | if (nr_to_scan-- == 0) |
2057 | break; |
2058 | inode = &nfsi->vfs_inode; |
2059 | spin_lock(&inode->i_lock); |
2060 | if (list_empty(&nfsi->access_cache_entry_lru)) |
2061 | goto remove_lru_entry; |
2062 | cache = list_entry(nfsi->access_cache_entry_lru.next, |
2063 | struct nfs_access_entry, lru); |
2064 | list_move(&cache->lru, &head); |
2065 | rb_erase(&cache->rb_node, &nfsi->access_cache); |
2066 | if (!list_empty(&nfsi->access_cache_entry_lru)) |
2067 | list_move_tail(&nfsi->access_cache_inode_lru, |
2068 | &nfs_access_lru_list); |
2069 | else { |
2070 | remove_lru_entry: |
2071 | list_del_init(&nfsi->access_cache_inode_lru); |
2072 | smp_mb__before_clear_bit(); |
2073 | clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); |
2074 | smp_mb__after_clear_bit(); |
2075 | } |
2076 | spin_unlock(&inode->i_lock); |
2077 | } |
2078 | spin_unlock(&nfs_access_lru_lock); |
2079 | nfs_access_free_list(&head); |
2080 | return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; |
2081 | } |
2082 | |
2083 | static void __nfs_access_zap_cache(struct nfs_inode *nfsi, struct list_head *head) |
2084 | { |
2085 | struct rb_root *root_node = &nfsi->access_cache; |
2086 | struct rb_node *n; |
2087 | struct nfs_access_entry *entry; |
2088 | |
2089 | /* Unhook entries from the cache */ |
2090 | while ((n = rb_first(root_node)) != NULL) { |
2091 | entry = rb_entry(n, struct nfs_access_entry, rb_node); |
2092 | rb_erase(n, root_node); |
2093 | list_move(&entry->lru, head); |
2094 | } |
2095 | nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; |
2096 | } |
2097 | |
2098 | void nfs_access_zap_cache(struct inode *inode) |
2099 | { |
2100 | LIST_HEAD(head); |
2101 | |
2102 | if (test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags) == 0) |
2103 | return; |
2104 | /* Remove from global LRU init */ |
2105 | spin_lock(&nfs_access_lru_lock); |
2106 | if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) |
2107 | list_del_init(&NFS_I(inode)->access_cache_inode_lru); |
2108 | |
2109 | spin_lock(&inode->i_lock); |
2110 | __nfs_access_zap_cache(NFS_I(inode), &head); |
2111 | spin_unlock(&inode->i_lock); |
2112 | spin_unlock(&nfs_access_lru_lock); |
2113 | nfs_access_free_list(&head); |
2114 | } |
2115 | |
2116 | static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred) |
2117 | { |
2118 | struct rb_node *n = NFS_I(inode)->access_cache.rb_node; |
2119 | struct nfs_access_entry *entry; |
2120 | |
2121 | while (n != NULL) { |
2122 | entry = rb_entry(n, struct nfs_access_entry, rb_node); |
2123 | |
2124 | if (cred < entry->cred) |
2125 | n = n->rb_left; |
2126 | else if (cred > entry->cred) |
2127 | n = n->rb_right; |
2128 | else |
2129 | return entry; |
2130 | } |
2131 | return NULL; |
2132 | } |
2133 | |
2134 | static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) |
2135 | { |
2136 | struct nfs_inode *nfsi = NFS_I(inode); |
2137 | struct nfs_access_entry *cache; |
2138 | int err = -ENOENT; |
2139 | |
2140 | spin_lock(&inode->i_lock); |
2141 | if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) |
2142 | goto out_zap; |
2143 | cache = nfs_access_search_rbtree(inode, cred); |
2144 | if (cache == NULL) |
2145 | goto out; |
2146 | if (!nfs_have_delegated_attributes(inode) && |
2147 | !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo)) |
2148 | goto out_stale; |
2149 | res->jiffies = cache->jiffies; |
2150 | res->cred = cache->cred; |
2151 | res->mask = cache->mask; |
2152 | list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); |
2153 | err = 0; |
2154 | out: |
2155 | spin_unlock(&inode->i_lock); |
2156 | return err; |
2157 | out_stale: |
2158 | rb_erase(&cache->rb_node, &nfsi->access_cache); |
2159 | list_del(&cache->lru); |
2160 | spin_unlock(&inode->i_lock); |
2161 | nfs_access_free_entry(cache); |
2162 | return -ENOENT; |
2163 | out_zap: |
2164 | spin_unlock(&inode->i_lock); |
2165 | nfs_access_zap_cache(inode); |
2166 | return -ENOENT; |
2167 | } |
2168 | |
2169 | static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) |
2170 | { |
2171 | struct nfs_inode *nfsi = NFS_I(inode); |
2172 | struct rb_root *root_node = &nfsi->access_cache; |
2173 | struct rb_node **p = &root_node->rb_node; |
2174 | struct rb_node *parent = NULL; |
2175 | struct nfs_access_entry *entry; |
2176 | |
2177 | spin_lock(&inode->i_lock); |
2178 | while (*p != NULL) { |
2179 | parent = *p; |
2180 | entry = rb_entry(parent, struct nfs_access_entry, rb_node); |
2181 | |
2182 | if (set->cred < entry->cred) |
2183 | p = &parent->rb_left; |
2184 | else if (set->cred > entry->cred) |
2185 | p = &parent->rb_right; |
2186 | else |
2187 | goto found; |
2188 | } |
2189 | rb_link_node(&set->rb_node, parent, p); |
2190 | rb_insert_color(&set->rb_node, root_node); |
2191 | list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); |
2192 | spin_unlock(&inode->i_lock); |
2193 | return; |
2194 | found: |
2195 | rb_replace_node(parent, &set->rb_node, root_node); |
2196 | list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); |
2197 | list_del(&entry->lru); |
2198 | spin_unlock(&inode->i_lock); |
2199 | nfs_access_free_entry(entry); |
2200 | } |
2201 | |
2202 | static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) |
2203 | { |
2204 | struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); |
2205 | if (cache == NULL) |
2206 | return; |
2207 | RB_CLEAR_NODE(&cache->rb_node); |
2208 | cache->jiffies = set->jiffies; |
2209 | cache->cred = get_rpccred(set->cred); |
2210 | cache->mask = set->mask; |
2211 | |
2212 | nfs_access_add_rbtree(inode, cache); |
2213 | |
2214 | /* Update accounting */ |
2215 | smp_mb__before_atomic_inc(); |
2216 | atomic_long_inc(&nfs_access_nr_entries); |
2217 | smp_mb__after_atomic_inc(); |
2218 | |
2219 | /* Add inode to global LRU list */ |
2220 | if (!test_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { |
2221 | spin_lock(&nfs_access_lru_lock); |
2222 | if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) |
2223 | list_add_tail(&NFS_I(inode)->access_cache_inode_lru, |
2224 | &nfs_access_lru_list); |
2225 | spin_unlock(&nfs_access_lru_lock); |
2226 | } |
2227 | } |
2228 | |
2229 | static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) |
2230 | { |
2231 | struct nfs_access_entry cache; |
2232 | int status; |
2233 | |
2234 | status = nfs_access_get_cached(inode, cred, &cache); |
2235 | if (status == 0) |
2236 | goto out; |
2237 | |
2238 | /* Be clever: ask server to check for all possible rights */ |
2239 | cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; |
2240 | cache.cred = cred; |
2241 | cache.jiffies = jiffies; |
2242 | status = NFS_PROTO(inode)->access(inode, &cache); |
2243 | if (status != 0) { |
2244 | if (status == -ESTALE) { |
2245 | nfs_zap_caches(inode); |
2246 | if (!S_ISDIR(inode->i_mode)) |
2247 | set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); |
2248 | } |
2249 | return status; |
2250 | } |
2251 | nfs_access_add_cache(inode, &cache); |
2252 | out: |
2253 | if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) |
2254 | return 0; |
2255 | return -EACCES; |
2256 | } |
2257 | |
2258 | static int nfs_open_permission_mask(int openflags) |
2259 | { |
2260 | int mask = 0; |
2261 | |
2262 | if (openflags & FMODE_READ) |
2263 | mask |= MAY_READ; |
2264 | if (openflags & FMODE_WRITE) |
2265 | mask |= MAY_WRITE; |
2266 | if (openflags & FMODE_EXEC) |
2267 | mask |= MAY_EXEC; |
2268 | return mask; |
2269 | } |
2270 | |
2271 | int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) |
2272 | { |
2273 | return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); |
2274 | } |
2275 | |
2276 | int nfs_permission(struct inode *inode, int mask, unsigned int flags) |
2277 | { |
2278 | struct rpc_cred *cred; |
2279 | int res = 0; |
2280 | |
2281 | if (flags & IPERM_FLAG_RCU) |
2282 | return -ECHILD; |
2283 | |
2284 | nfs_inc_stats(inode, NFSIOS_VFSACCESS); |
2285 | |
2286 | if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) |
2287 | goto out; |
2288 | /* Is this sys_access() ? */ |
2289 | if (mask & (MAY_ACCESS | MAY_CHDIR)) |
2290 | goto force_lookup; |
2291 | |
2292 | switch (inode->i_mode & S_IFMT) { |
2293 | case S_IFLNK: |
2294 | goto out; |
2295 | case S_IFREG: |
2296 | /* NFSv4 has atomic_open... */ |
2297 | if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) |
2298 | && (mask & MAY_OPEN) |
2299 | && !(mask & MAY_EXEC)) |
2300 | goto out; |
2301 | break; |
2302 | case S_IFDIR: |
2303 | /* |
2304 | * Optimize away all write operations, since the server |
2305 | * will check permissions when we perform the op. |
2306 | */ |
2307 | if ((mask & MAY_WRITE) && !(mask & MAY_READ)) |
2308 | goto out; |
2309 | } |
2310 | |
2311 | force_lookup: |
2312 | if (!NFS_PROTO(inode)->access) |
2313 | goto out_notsup; |
2314 | |
2315 | cred = rpc_lookup_cred(); |
2316 | if (!IS_ERR(cred)) { |
2317 | res = nfs_do_access(inode, cred, mask); |
2318 | put_rpccred(cred); |
2319 | } else |
2320 | res = PTR_ERR(cred); |
2321 | out: |
2322 | if (!res && (mask & MAY_EXEC) && !execute_ok(inode)) |
2323 | res = -EACCES; |
2324 | |
2325 | dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n", |
2326 | inode->i_sb->s_id, inode->i_ino, mask, res); |
2327 | return res; |
2328 | out_notsup: |
2329 | res = nfs_revalidate_inode(NFS_SERVER(inode), inode); |
2330 | if (res == 0) |
2331 | res = generic_permission(inode, mask, flags, NULL); |
2332 | goto out; |
2333 | } |
2334 | |
2335 | /* |
2336 | * Local variables: |
2337 | * version-control: t |
2338 | * kept-new-versions: 5 |
2339 | * End: |
2340 | */ |
2341 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9