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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 | |
37 | #include "nfs4_fs.h" |
38 | #include "delegation.h" |
39 | #include "iostat.h" |
40 | #include "internal.h" |
41 | |
42 | /* #define NFS_DEBUG_VERBOSE 1 */ |
43 | |
44 | static int nfs_opendir(struct inode *, struct file *); |
45 | static int nfs_readdir(struct file *, void *, filldir_t); |
46 | static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *); |
47 | static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *); |
48 | static int nfs_mkdir(struct inode *, struct dentry *, int); |
49 | static int nfs_rmdir(struct inode *, struct dentry *); |
50 | static int nfs_unlink(struct inode *, struct dentry *); |
51 | static int nfs_symlink(struct inode *, struct dentry *, const char *); |
52 | static int nfs_link(struct dentry *, struct inode *, struct dentry *); |
53 | static int nfs_mknod(struct inode *, struct dentry *, int, dev_t); |
54 | static int nfs_rename(struct inode *, struct dentry *, |
55 | struct inode *, struct dentry *); |
56 | static int nfs_fsync_dir(struct file *, struct dentry *, int); |
57 | static loff_t nfs_llseek_dir(struct file *, loff_t, int); |
58 | |
59 | const struct file_operations nfs_dir_operations = { |
60 | .llseek = nfs_llseek_dir, |
61 | .read = generic_read_dir, |
62 | .readdir = nfs_readdir, |
63 | .open = nfs_opendir, |
64 | .release = nfs_release, |
65 | .fsync = nfs_fsync_dir, |
66 | }; |
67 | |
68 | const struct inode_operations nfs_dir_inode_operations = { |
69 | .create = nfs_create, |
70 | .lookup = nfs_lookup, |
71 | .link = nfs_link, |
72 | .unlink = nfs_unlink, |
73 | .symlink = nfs_symlink, |
74 | .mkdir = nfs_mkdir, |
75 | .rmdir = nfs_rmdir, |
76 | .mknod = nfs_mknod, |
77 | .rename = nfs_rename, |
78 | .permission = nfs_permission, |
79 | .getattr = nfs_getattr, |
80 | .setattr = nfs_setattr, |
81 | }; |
82 | |
83 | #ifdef CONFIG_NFS_V3 |
84 | const struct inode_operations nfs3_dir_inode_operations = { |
85 | .create = nfs_create, |
86 | .lookup = nfs_lookup, |
87 | .link = nfs_link, |
88 | .unlink = nfs_unlink, |
89 | .symlink = nfs_symlink, |
90 | .mkdir = nfs_mkdir, |
91 | .rmdir = nfs_rmdir, |
92 | .mknod = nfs_mknod, |
93 | .rename = nfs_rename, |
94 | .permission = nfs_permission, |
95 | .getattr = nfs_getattr, |
96 | .setattr = nfs_setattr, |
97 | .listxattr = nfs3_listxattr, |
98 | .getxattr = nfs3_getxattr, |
99 | .setxattr = nfs3_setxattr, |
100 | .removexattr = nfs3_removexattr, |
101 | }; |
102 | #endif /* CONFIG_NFS_V3 */ |
103 | |
104 | #ifdef CONFIG_NFS_V4 |
105 | |
106 | static struct dentry *nfs_atomic_lookup(struct inode *, struct dentry *, struct nameidata *); |
107 | const struct inode_operations nfs4_dir_inode_operations = { |
108 | .create = nfs_create, |
109 | .lookup = nfs_atomic_lookup, |
110 | .link = nfs_link, |
111 | .unlink = nfs_unlink, |
112 | .symlink = nfs_symlink, |
113 | .mkdir = nfs_mkdir, |
114 | .rmdir = nfs_rmdir, |
115 | .mknod = nfs_mknod, |
116 | .rename = nfs_rename, |
117 | .permission = nfs_permission, |
118 | .getattr = nfs_getattr, |
119 | .setattr = nfs_setattr, |
120 | .getxattr = nfs4_getxattr, |
121 | .setxattr = nfs4_setxattr, |
122 | .listxattr = nfs4_listxattr, |
123 | }; |
124 | |
125 | #endif /* CONFIG_NFS_V4 */ |
126 | |
127 | /* |
128 | * Open file |
129 | */ |
130 | static int |
131 | nfs_opendir(struct inode *inode, struct file *filp) |
132 | { |
133 | int res; |
134 | |
135 | dfprintk(FILE, "NFS: open dir(%s/%s)\n", |
136 | filp->f_path.dentry->d_parent->d_name.name, |
137 | filp->f_path.dentry->d_name.name); |
138 | |
139 | nfs_inc_stats(inode, NFSIOS_VFSOPEN); |
140 | |
141 | /* Call generic open code in order to cache credentials */ |
142 | res = nfs_open(inode, filp); |
143 | return res; |
144 | } |
145 | |
146 | typedef __be32 * (*decode_dirent_t)(__be32 *, struct nfs_entry *, int); |
147 | typedef struct { |
148 | struct file *file; |
149 | struct page *page; |
150 | unsigned long page_index; |
151 | __be32 *ptr; |
152 | u64 *dir_cookie; |
153 | loff_t current_index; |
154 | struct nfs_entry *entry; |
155 | decode_dirent_t decode; |
156 | int plus; |
157 | unsigned long timestamp; |
158 | unsigned long gencount; |
159 | int timestamp_valid; |
160 | } nfs_readdir_descriptor_t; |
161 | |
162 | /* Now we cache directories properly, by stuffing the dirent |
163 | * data directly in the page cache. |
164 | * |
165 | * Inode invalidation due to refresh etc. takes care of |
166 | * _everything_, no sloppy entry flushing logic, no extraneous |
167 | * copying, network direct to page cache, the way it was meant |
168 | * to be. |
169 | * |
170 | * NOTE: Dirent information verification is done always by the |
171 | * page-in of the RPC reply, nowhere else, this simplies |
172 | * things substantially. |
173 | */ |
174 | static |
175 | int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page *page) |
176 | { |
177 | struct file *file = desc->file; |
178 | struct inode *inode = file->f_path.dentry->d_inode; |
179 | struct rpc_cred *cred = nfs_file_cred(file); |
180 | unsigned long timestamp, gencount; |
181 | int error; |
182 | |
183 | dfprintk(DIRCACHE, "NFS: %s: reading cookie %Lu into page %lu\n", |
184 | __func__, (long long)desc->entry->cookie, |
185 | page->index); |
186 | |
187 | again: |
188 | timestamp = jiffies; |
189 | gencount = nfs_inc_attr_generation_counter(); |
190 | error = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, desc->entry->cookie, page, |
191 | NFS_SERVER(inode)->dtsize, desc->plus); |
192 | if (error < 0) { |
193 | /* We requested READDIRPLUS, but the server doesn't grok it */ |
194 | if (error == -ENOTSUPP && desc->plus) { |
195 | NFS_SERVER(inode)->caps &= ~NFS_CAP_READDIRPLUS; |
196 | clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); |
197 | desc->plus = 0; |
198 | goto again; |
199 | } |
200 | goto error; |
201 | } |
202 | desc->timestamp = timestamp; |
203 | desc->gencount = gencount; |
204 | desc->timestamp_valid = 1; |
205 | SetPageUptodate(page); |
206 | /* Ensure consistent page alignment of the data. |
207 | * Note: assumes we have exclusive access to this mapping either |
208 | * through inode->i_mutex or some other mechanism. |
209 | */ |
210 | if (invalidate_inode_pages2_range(inode->i_mapping, page->index + 1, -1) < 0) { |
211 | /* Should never happen */ |
212 | nfs_zap_mapping(inode, inode->i_mapping); |
213 | } |
214 | unlock_page(page); |
215 | return 0; |
216 | error: |
217 | unlock_page(page); |
218 | return -EIO; |
219 | } |
220 | |
221 | static inline |
222 | int dir_decode(nfs_readdir_descriptor_t *desc) |
223 | { |
224 | __be32 *p = desc->ptr; |
225 | p = desc->decode(p, desc->entry, desc->plus); |
226 | if (IS_ERR(p)) |
227 | return PTR_ERR(p); |
228 | desc->ptr = p; |
229 | if (desc->timestamp_valid) { |
230 | desc->entry->fattr->time_start = desc->timestamp; |
231 | desc->entry->fattr->gencount = desc->gencount; |
232 | } else |
233 | desc->entry->fattr->valid &= ~NFS_ATTR_FATTR; |
234 | return 0; |
235 | } |
236 | |
237 | static inline |
238 | void dir_page_release(nfs_readdir_descriptor_t *desc) |
239 | { |
240 | kunmap(desc->page); |
241 | page_cache_release(desc->page); |
242 | desc->page = NULL; |
243 | desc->ptr = NULL; |
244 | } |
245 | |
246 | /* |
247 | * Given a pointer to a buffer that has already been filled by a call |
248 | * to readdir, find the next entry with cookie '*desc->dir_cookie'. |
249 | * |
250 | * If the end of the buffer has been reached, return -EAGAIN, if not, |
251 | * return the offset within the buffer of the next entry to be |
252 | * read. |
253 | */ |
254 | static inline |
255 | int find_dirent(nfs_readdir_descriptor_t *desc) |
256 | { |
257 | struct nfs_entry *entry = desc->entry; |
258 | int loop_count = 0, |
259 | status; |
260 | |
261 | while((status = dir_decode(desc)) == 0) { |
262 | dfprintk(DIRCACHE, "NFS: %s: examining cookie %Lu\n", |
263 | __func__, (unsigned long long)entry->cookie); |
264 | if (entry->prev_cookie == *desc->dir_cookie) |
265 | break; |
266 | if (loop_count++ > 200) { |
267 | loop_count = 0; |
268 | schedule(); |
269 | } |
270 | } |
271 | return status; |
272 | } |
273 | |
274 | /* |
275 | * Given a pointer to a buffer that has already been filled by a call |
276 | * to readdir, find the entry at offset 'desc->file->f_pos'. |
277 | * |
278 | * If the end of the buffer has been reached, return -EAGAIN, if not, |
279 | * return the offset within the buffer of the next entry to be |
280 | * read. |
281 | */ |
282 | static inline |
283 | int find_dirent_index(nfs_readdir_descriptor_t *desc) |
284 | { |
285 | struct nfs_entry *entry = desc->entry; |
286 | int loop_count = 0, |
287 | status; |
288 | |
289 | for(;;) { |
290 | status = dir_decode(desc); |
291 | if (status) |
292 | break; |
293 | |
294 | dfprintk(DIRCACHE, "NFS: found cookie %Lu at index %Ld\n", |
295 | (unsigned long long)entry->cookie, desc->current_index); |
296 | |
297 | if (desc->file->f_pos == desc->current_index) { |
298 | *desc->dir_cookie = entry->cookie; |
299 | break; |
300 | } |
301 | desc->current_index++; |
302 | if (loop_count++ > 200) { |
303 | loop_count = 0; |
304 | schedule(); |
305 | } |
306 | } |
307 | return status; |
308 | } |
309 | |
310 | /* |
311 | * Find the given page, and call find_dirent() or find_dirent_index in |
312 | * order to try to return the next entry. |
313 | */ |
314 | static inline |
315 | int find_dirent_page(nfs_readdir_descriptor_t *desc) |
316 | { |
317 | struct inode *inode = desc->file->f_path.dentry->d_inode; |
318 | struct page *page; |
319 | int status; |
320 | |
321 | dfprintk(DIRCACHE, "NFS: %s: searching page %ld for target %Lu\n", |
322 | __func__, desc->page_index, |
323 | (long long) *desc->dir_cookie); |
324 | |
325 | /* If we find the page in the page_cache, we cannot be sure |
326 | * how fresh the data is, so we will ignore readdir_plus attributes. |
327 | */ |
328 | desc->timestamp_valid = 0; |
329 | page = read_cache_page(inode->i_mapping, desc->page_index, |
330 | (filler_t *)nfs_readdir_filler, desc); |
331 | if (IS_ERR(page)) { |
332 | status = PTR_ERR(page); |
333 | goto out; |
334 | } |
335 | |
336 | /* NOTE: Someone else may have changed the READDIRPLUS flag */ |
337 | desc->page = page; |
338 | desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ |
339 | if (*desc->dir_cookie != 0) |
340 | status = find_dirent(desc); |
341 | else |
342 | status = find_dirent_index(desc); |
343 | if (status < 0) |
344 | dir_page_release(desc); |
345 | out: |
346 | dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, status); |
347 | return status; |
348 | } |
349 | |
350 | /* |
351 | * Recurse through the page cache pages, and return a |
352 | * filled nfs_entry structure of the next directory entry if possible. |
353 | * |
354 | * The target for the search is '*desc->dir_cookie' if non-0, |
355 | * 'desc->file->f_pos' otherwise |
356 | */ |
357 | static inline |
358 | int readdir_search_pagecache(nfs_readdir_descriptor_t *desc) |
359 | { |
360 | int loop_count = 0; |
361 | int res; |
362 | |
363 | /* Always search-by-index from the beginning of the cache */ |
364 | if (*desc->dir_cookie == 0) { |
365 | dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for offset %Ld\n", |
366 | (long long)desc->file->f_pos); |
367 | desc->page_index = 0; |
368 | desc->entry->cookie = desc->entry->prev_cookie = 0; |
369 | desc->entry->eof = 0; |
370 | desc->current_index = 0; |
371 | } else |
372 | dfprintk(DIRCACHE, "NFS: readdir_search_pagecache() searching for cookie %Lu\n", |
373 | (unsigned long long)*desc->dir_cookie); |
374 | |
375 | for (;;) { |
376 | res = find_dirent_page(desc); |
377 | if (res != -EAGAIN) |
378 | break; |
379 | /* Align to beginning of next page */ |
380 | desc->page_index ++; |
381 | if (loop_count++ > 200) { |
382 | loop_count = 0; |
383 | schedule(); |
384 | } |
385 | } |
386 | |
387 | dfprintk(DIRCACHE, "NFS: %s: returns %d\n", __func__, res); |
388 | return res; |
389 | } |
390 | |
391 | static inline unsigned int dt_type(struct inode *inode) |
392 | { |
393 | return (inode->i_mode >> 12) & 15; |
394 | } |
395 | |
396 | static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc); |
397 | |
398 | /* |
399 | * Once we've found the start of the dirent within a page: fill 'er up... |
400 | */ |
401 | static |
402 | int nfs_do_filldir(nfs_readdir_descriptor_t *desc, void *dirent, |
403 | filldir_t filldir) |
404 | { |
405 | struct file *file = desc->file; |
406 | struct nfs_entry *entry = desc->entry; |
407 | struct dentry *dentry = NULL; |
408 | u64 fileid; |
409 | int loop_count = 0, |
410 | res; |
411 | |
412 | dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling starting @ cookie %Lu\n", |
413 | (unsigned long long)entry->cookie); |
414 | |
415 | for(;;) { |
416 | unsigned d_type = DT_UNKNOWN; |
417 | /* Note: entry->prev_cookie contains the cookie for |
418 | * retrieving the current dirent on the server */ |
419 | fileid = entry->ino; |
420 | |
421 | /* Get a dentry if we have one */ |
422 | if (dentry != NULL) |
423 | dput(dentry); |
424 | dentry = nfs_readdir_lookup(desc); |
425 | |
426 | /* Use readdirplus info */ |
427 | if (dentry != NULL && dentry->d_inode != NULL) { |
428 | d_type = dt_type(dentry->d_inode); |
429 | fileid = NFS_FILEID(dentry->d_inode); |
430 | } |
431 | |
432 | res = filldir(dirent, entry->name, entry->len, |
433 | file->f_pos, nfs_compat_user_ino64(fileid), |
434 | d_type); |
435 | if (res < 0) |
436 | break; |
437 | file->f_pos++; |
438 | *desc->dir_cookie = entry->cookie; |
439 | if (dir_decode(desc) != 0) { |
440 | desc->page_index ++; |
441 | break; |
442 | } |
443 | if (loop_count++ > 200) { |
444 | loop_count = 0; |
445 | schedule(); |
446 | } |
447 | } |
448 | dir_page_release(desc); |
449 | if (dentry != NULL) |
450 | dput(dentry); |
451 | dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n", |
452 | (unsigned long long)*desc->dir_cookie, res); |
453 | return res; |
454 | } |
455 | |
456 | /* |
457 | * If we cannot find a cookie in our cache, we suspect that this is |
458 | * because it points to a deleted file, so we ask the server to return |
459 | * whatever it thinks is the next entry. We then feed this to filldir. |
460 | * If all goes well, we should then be able to find our way round the |
461 | * cache on the next call to readdir_search_pagecache(); |
462 | * |
463 | * NOTE: we cannot add the anonymous page to the pagecache because |
464 | * the data it contains might not be page aligned. Besides, |
465 | * we should already have a complete representation of the |
466 | * directory in the page cache by the time we get here. |
467 | */ |
468 | static inline |
469 | int uncached_readdir(nfs_readdir_descriptor_t *desc, void *dirent, |
470 | filldir_t filldir) |
471 | { |
472 | struct file *file = desc->file; |
473 | struct inode *inode = file->f_path.dentry->d_inode; |
474 | struct rpc_cred *cred = nfs_file_cred(file); |
475 | struct page *page = NULL; |
476 | int status; |
477 | unsigned long timestamp, gencount; |
478 | |
479 | dfprintk(DIRCACHE, "NFS: uncached_readdir() searching for cookie %Lu\n", |
480 | (unsigned long long)*desc->dir_cookie); |
481 | |
482 | page = alloc_page(GFP_HIGHUSER); |
483 | if (!page) { |
484 | status = -ENOMEM; |
485 | goto out; |
486 | } |
487 | timestamp = jiffies; |
488 | gencount = nfs_inc_attr_generation_counter(); |
489 | status = NFS_PROTO(inode)->readdir(file->f_path.dentry, cred, |
490 | *desc->dir_cookie, page, |
491 | NFS_SERVER(inode)->dtsize, |
492 | desc->plus); |
493 | desc->page = page; |
494 | desc->ptr = kmap(page); /* matching kunmap in nfs_do_filldir */ |
495 | if (status >= 0) { |
496 | desc->timestamp = timestamp; |
497 | desc->gencount = gencount; |
498 | desc->timestamp_valid = 1; |
499 | if ((status = dir_decode(desc)) == 0) |
500 | desc->entry->prev_cookie = *desc->dir_cookie; |
501 | } else |
502 | status = -EIO; |
503 | if (status < 0) |
504 | goto out_release; |
505 | |
506 | status = nfs_do_filldir(desc, dirent, filldir); |
507 | |
508 | /* Reset read descriptor so it searches the page cache from |
509 | * the start upon the next call to readdir_search_pagecache() */ |
510 | desc->page_index = 0; |
511 | desc->entry->cookie = desc->entry->prev_cookie = 0; |
512 | desc->entry->eof = 0; |
513 | out: |
514 | dfprintk(DIRCACHE, "NFS: %s: returns %d\n", |
515 | __func__, status); |
516 | return status; |
517 | out_release: |
518 | dir_page_release(desc); |
519 | goto out; |
520 | } |
521 | |
522 | /* The file offset position represents the dirent entry number. A |
523 | last cookie cache takes care of the common case of reading the |
524 | whole directory. |
525 | */ |
526 | static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir) |
527 | { |
528 | struct dentry *dentry = filp->f_path.dentry; |
529 | struct inode *inode = dentry->d_inode; |
530 | nfs_readdir_descriptor_t my_desc, |
531 | *desc = &my_desc; |
532 | struct nfs_entry my_entry; |
533 | struct nfs_fh fh; |
534 | struct nfs_fattr fattr; |
535 | long res; |
536 | |
537 | dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n", |
538 | dentry->d_parent->d_name.name, dentry->d_name.name, |
539 | (long long)filp->f_pos); |
540 | nfs_inc_stats(inode, NFSIOS_VFSGETDENTS); |
541 | |
542 | /* |
543 | * filp->f_pos points to the dirent entry number. |
544 | * *desc->dir_cookie has the cookie for the next entry. We have |
545 | * to either find the entry with the appropriate number or |
546 | * revalidate the cookie. |
547 | */ |
548 | memset(desc, 0, sizeof(*desc)); |
549 | |
550 | desc->file = filp; |
551 | desc->dir_cookie = &nfs_file_open_context(filp)->dir_cookie; |
552 | desc->decode = NFS_PROTO(inode)->decode_dirent; |
553 | desc->plus = NFS_USE_READDIRPLUS(inode); |
554 | |
555 | my_entry.cookie = my_entry.prev_cookie = 0; |
556 | my_entry.eof = 0; |
557 | my_entry.fh = &fh; |
558 | my_entry.fattr = &fattr; |
559 | nfs_fattr_init(&fattr); |
560 | desc->entry = &my_entry; |
561 | |
562 | nfs_block_sillyrename(dentry); |
563 | res = nfs_revalidate_mapping_nolock(inode, filp->f_mapping); |
564 | if (res < 0) |
565 | goto out; |
566 | |
567 | while(!desc->entry->eof) { |
568 | res = readdir_search_pagecache(desc); |
569 | |
570 | if (res == -EBADCOOKIE) { |
571 | /* This means either end of directory */ |
572 | if (*desc->dir_cookie && desc->entry->cookie != *desc->dir_cookie) { |
573 | /* Or that the server has 'lost' a cookie */ |
574 | res = uncached_readdir(desc, dirent, filldir); |
575 | if (res >= 0) |
576 | continue; |
577 | } |
578 | res = 0; |
579 | break; |
580 | } |
581 | if (res == -ETOOSMALL && desc->plus) { |
582 | clear_bit(NFS_INO_ADVISE_RDPLUS, &NFS_I(inode)->flags); |
583 | nfs_zap_caches(inode); |
584 | desc->plus = 0; |
585 | desc->entry->eof = 0; |
586 | continue; |
587 | } |
588 | if (res < 0) |
589 | break; |
590 | |
591 | res = nfs_do_filldir(desc, dirent, filldir); |
592 | if (res < 0) { |
593 | res = 0; |
594 | break; |
595 | } |
596 | } |
597 | out: |
598 | nfs_unblock_sillyrename(dentry); |
599 | if (res > 0) |
600 | res = 0; |
601 | dfprintk(FILE, "NFS: readdir(%s/%s) returns %ld\n", |
602 | dentry->d_parent->d_name.name, dentry->d_name.name, |
603 | res); |
604 | return res; |
605 | } |
606 | |
607 | static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin) |
608 | { |
609 | struct dentry *dentry = filp->f_path.dentry; |
610 | struct inode *inode = dentry->d_inode; |
611 | |
612 | dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n", |
613 | dentry->d_parent->d_name.name, |
614 | dentry->d_name.name, |
615 | offset, origin); |
616 | |
617 | mutex_lock(&inode->i_mutex); |
618 | switch (origin) { |
619 | case 1: |
620 | offset += filp->f_pos; |
621 | case 0: |
622 | if (offset >= 0) |
623 | break; |
624 | default: |
625 | offset = -EINVAL; |
626 | goto out; |
627 | } |
628 | if (offset != filp->f_pos) { |
629 | filp->f_pos = offset; |
630 | nfs_file_open_context(filp)->dir_cookie = 0; |
631 | } |
632 | out: |
633 | mutex_unlock(&inode->i_mutex); |
634 | return offset; |
635 | } |
636 | |
637 | /* |
638 | * All directory operations under NFS are synchronous, so fsync() |
639 | * is a dummy operation. |
640 | */ |
641 | static int nfs_fsync_dir(struct file *filp, struct dentry *dentry, int datasync) |
642 | { |
643 | dfprintk(FILE, "NFS: fsync dir(%s/%s) datasync %d\n", |
644 | dentry->d_parent->d_name.name, dentry->d_name.name, |
645 | datasync); |
646 | |
647 | nfs_inc_stats(dentry->d_inode, NFSIOS_VFSFSYNC); |
648 | return 0; |
649 | } |
650 | |
651 | /** |
652 | * nfs_force_lookup_revalidate - Mark the directory as having changed |
653 | * @dir - pointer to directory inode |
654 | * |
655 | * This forces the revalidation code in nfs_lookup_revalidate() to do a |
656 | * full lookup on all child dentries of 'dir' whenever a change occurs |
657 | * on the server that might have invalidated our dcache. |
658 | * |
659 | * The caller should be holding dir->i_lock |
660 | */ |
661 | void nfs_force_lookup_revalidate(struct inode *dir) |
662 | { |
663 | NFS_I(dir)->cache_change_attribute++; |
664 | } |
665 | |
666 | /* |
667 | * A check for whether or not the parent directory has changed. |
668 | * In the case it has, we assume that the dentries are untrustworthy |
669 | * and may need to be looked up again. |
670 | */ |
671 | static int nfs_check_verifier(struct inode *dir, struct dentry *dentry) |
672 | { |
673 | if (IS_ROOT(dentry)) |
674 | return 1; |
675 | if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONE) |
676 | return 0; |
677 | if (!nfs_verify_change_attribute(dir, dentry->d_time)) |
678 | return 0; |
679 | /* Revalidate nfsi->cache_change_attribute before we declare a match */ |
680 | if (nfs_revalidate_inode(NFS_SERVER(dir), dir) < 0) |
681 | return 0; |
682 | if (!nfs_verify_change_attribute(dir, dentry->d_time)) |
683 | return 0; |
684 | return 1; |
685 | } |
686 | |
687 | /* |
688 | * Return the intent data that applies to this particular path component |
689 | * |
690 | * Note that the current set of intents only apply to the very last |
691 | * component of the path. |
692 | * We check for this using LOOKUP_CONTINUE and LOOKUP_PARENT. |
693 | */ |
694 | static inline unsigned int nfs_lookup_check_intent(struct nameidata *nd, unsigned int mask) |
695 | { |
696 | if (nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT)) |
697 | return 0; |
698 | return nd->flags & mask; |
699 | } |
700 | |
701 | /* |
702 | * Use intent information to check whether or not we're going to do |
703 | * an O_EXCL create using this path component. |
704 | */ |
705 | static int nfs_is_exclusive_create(struct inode *dir, struct nameidata *nd) |
706 | { |
707 | if (NFS_PROTO(dir)->version == 2) |
708 | return 0; |
709 | return nd && nfs_lookup_check_intent(nd, LOOKUP_EXCL); |
710 | } |
711 | |
712 | /* |
713 | * Inode and filehandle revalidation for lookups. |
714 | * |
715 | * We force revalidation in the cases where the VFS sets LOOKUP_REVAL, |
716 | * or if the intent information indicates that we're about to open this |
717 | * particular file and the "nocto" mount flag is not set. |
718 | * |
719 | */ |
720 | static inline |
721 | int nfs_lookup_verify_inode(struct inode *inode, struct nameidata *nd) |
722 | { |
723 | struct nfs_server *server = NFS_SERVER(inode); |
724 | |
725 | if (test_bit(NFS_INO_MOUNTPOINT, &NFS_I(inode)->flags)) |
726 | return 0; |
727 | if (nd != NULL) { |
728 | /* VFS wants an on-the-wire revalidation */ |
729 | if (nd->flags & LOOKUP_REVAL) |
730 | goto out_force; |
731 | /* This is an open(2) */ |
732 | if (nfs_lookup_check_intent(nd, LOOKUP_OPEN) != 0 && |
733 | !(server->flags & NFS_MOUNT_NOCTO) && |
734 | (S_ISREG(inode->i_mode) || |
735 | S_ISDIR(inode->i_mode))) |
736 | goto out_force; |
737 | return 0; |
738 | } |
739 | return nfs_revalidate_inode(server, inode); |
740 | out_force: |
741 | return __nfs_revalidate_inode(server, inode); |
742 | } |
743 | |
744 | /* |
745 | * We judge how long we want to trust negative |
746 | * dentries by looking at the parent inode mtime. |
747 | * |
748 | * If parent mtime has changed, we revalidate, else we wait for a |
749 | * period corresponding to the parent's attribute cache timeout value. |
750 | */ |
751 | static inline |
752 | int nfs_neg_need_reval(struct inode *dir, struct dentry *dentry, |
753 | struct nameidata *nd) |
754 | { |
755 | /* Don't revalidate a negative dentry if we're creating a new file */ |
756 | if (nd != NULL && nfs_lookup_check_intent(nd, LOOKUP_CREATE) != 0) |
757 | return 0; |
758 | if (NFS_SERVER(dir)->flags & NFS_MOUNT_LOOKUP_CACHE_NONEG) |
759 | return 1; |
760 | return !nfs_check_verifier(dir, dentry); |
761 | } |
762 | |
763 | /* |
764 | * This is called every time the dcache has a lookup hit, |
765 | * and we should check whether we can really trust that |
766 | * lookup. |
767 | * |
768 | * NOTE! The hit can be a negative hit too, don't assume |
769 | * we have an inode! |
770 | * |
771 | * If the parent directory is seen to have changed, we throw out the |
772 | * cached dentry and do a new lookup. |
773 | */ |
774 | static int nfs_lookup_revalidate(struct dentry * dentry, struct nameidata *nd) |
775 | { |
776 | struct inode *dir; |
777 | struct inode *inode; |
778 | struct dentry *parent; |
779 | int error; |
780 | struct nfs_fh fhandle; |
781 | struct nfs_fattr fattr; |
782 | |
783 | parent = dget_parent(dentry); |
784 | dir = parent->d_inode; |
785 | nfs_inc_stats(dir, NFSIOS_DENTRYREVALIDATE); |
786 | inode = dentry->d_inode; |
787 | |
788 | if (!inode) { |
789 | if (nfs_neg_need_reval(dir, dentry, nd)) |
790 | goto out_bad; |
791 | goto out_valid; |
792 | } |
793 | |
794 | if (is_bad_inode(inode)) { |
795 | dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n", |
796 | __func__, dentry->d_parent->d_name.name, |
797 | dentry->d_name.name); |
798 | goto out_bad; |
799 | } |
800 | |
801 | if (nfs_have_delegation(inode, FMODE_READ)) |
802 | goto out_set_verifier; |
803 | |
804 | /* Force a full look up iff the parent directory has changed */ |
805 | if (!nfs_is_exclusive_create(dir, nd) && nfs_check_verifier(dir, dentry)) { |
806 | if (nfs_lookup_verify_inode(inode, nd)) |
807 | goto out_zap_parent; |
808 | goto out_valid; |
809 | } |
810 | |
811 | if (NFS_STALE(inode)) |
812 | goto out_bad; |
813 | |
814 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr); |
815 | if (error) |
816 | goto out_bad; |
817 | if (nfs_compare_fh(NFS_FH(inode), &fhandle)) |
818 | goto out_bad; |
819 | if ((error = nfs_refresh_inode(inode, &fattr)) != 0) |
820 | goto out_bad; |
821 | |
822 | out_set_verifier: |
823 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
824 | out_valid: |
825 | dput(parent); |
826 | dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is valid\n", |
827 | __func__, dentry->d_parent->d_name.name, |
828 | dentry->d_name.name); |
829 | return 1; |
830 | out_zap_parent: |
831 | nfs_zap_caches(dir); |
832 | out_bad: |
833 | nfs_mark_for_revalidate(dir); |
834 | if (inode && S_ISDIR(inode->i_mode)) { |
835 | /* Purge readdir caches. */ |
836 | nfs_zap_caches(inode); |
837 | /* If we have submounts, don't unhash ! */ |
838 | if (have_submounts(dentry)) |
839 | goto out_valid; |
840 | shrink_dcache_parent(dentry); |
841 | } |
842 | d_drop(dentry); |
843 | dput(parent); |
844 | dfprintk(LOOKUPCACHE, "NFS: %s(%s/%s) is invalid\n", |
845 | __func__, dentry->d_parent->d_name.name, |
846 | dentry->d_name.name); |
847 | return 0; |
848 | } |
849 | |
850 | /* |
851 | * This is called from dput() when d_count is going to 0. |
852 | */ |
853 | static int nfs_dentry_delete(struct dentry *dentry) |
854 | { |
855 | dfprintk(VFS, "NFS: dentry_delete(%s/%s, %x)\n", |
856 | dentry->d_parent->d_name.name, dentry->d_name.name, |
857 | dentry->d_flags); |
858 | |
859 | /* Unhash any dentry with a stale inode */ |
860 | if (dentry->d_inode != NULL && NFS_STALE(dentry->d_inode)) |
861 | return 1; |
862 | |
863 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
864 | /* Unhash it, so that ->d_iput() would be called */ |
865 | return 1; |
866 | } |
867 | if (!(dentry->d_sb->s_flags & MS_ACTIVE)) { |
868 | /* Unhash it, so that ancestors of killed async unlink |
869 | * files will be cleaned up during umount */ |
870 | return 1; |
871 | } |
872 | return 0; |
873 | |
874 | } |
875 | |
876 | static void nfs_drop_nlink(struct inode *inode) |
877 | { |
878 | spin_lock(&inode->i_lock); |
879 | if (inode->i_nlink > 0) |
880 | drop_nlink(inode); |
881 | spin_unlock(&inode->i_lock); |
882 | } |
883 | |
884 | /* |
885 | * Called when the dentry loses inode. |
886 | * We use it to clean up silly-renamed files. |
887 | */ |
888 | static void nfs_dentry_iput(struct dentry *dentry, struct inode *inode) |
889 | { |
890 | if (S_ISDIR(inode->i_mode)) |
891 | /* drop any readdir cache as it could easily be old */ |
892 | NFS_I(inode)->cache_validity |= NFS_INO_INVALID_DATA; |
893 | |
894 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
895 | drop_nlink(inode); |
896 | nfs_complete_unlink(dentry, inode); |
897 | } |
898 | iput(inode); |
899 | } |
900 | |
901 | const struct dentry_operations nfs_dentry_operations = { |
902 | .d_revalidate = nfs_lookup_revalidate, |
903 | .d_delete = nfs_dentry_delete, |
904 | .d_iput = nfs_dentry_iput, |
905 | }; |
906 | |
907 | static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd) |
908 | { |
909 | struct dentry *res; |
910 | struct dentry *parent; |
911 | struct inode *inode = NULL; |
912 | int error; |
913 | struct nfs_fh fhandle; |
914 | struct nfs_fattr fattr; |
915 | |
916 | dfprintk(VFS, "NFS: lookup(%s/%s)\n", |
917 | dentry->d_parent->d_name.name, dentry->d_name.name); |
918 | nfs_inc_stats(dir, NFSIOS_VFSLOOKUP); |
919 | |
920 | res = ERR_PTR(-ENAMETOOLONG); |
921 | if (dentry->d_name.len > NFS_SERVER(dir)->namelen) |
922 | goto out; |
923 | |
924 | res = ERR_PTR(-ENOMEM); |
925 | dentry->d_op = NFS_PROTO(dir)->dentry_ops; |
926 | |
927 | /* |
928 | * If we're doing an exclusive create, optimize away the lookup |
929 | * but don't hash the dentry. |
930 | */ |
931 | if (nfs_is_exclusive_create(dir, nd)) { |
932 | d_instantiate(dentry, NULL); |
933 | res = NULL; |
934 | goto out; |
935 | } |
936 | |
937 | parent = dentry->d_parent; |
938 | /* Protect against concurrent sillydeletes */ |
939 | nfs_block_sillyrename(parent); |
940 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, &fhandle, &fattr); |
941 | if (error == -ENOENT) |
942 | goto no_entry; |
943 | if (error < 0) { |
944 | res = ERR_PTR(error); |
945 | goto out_unblock_sillyrename; |
946 | } |
947 | inode = nfs_fhget(dentry->d_sb, &fhandle, &fattr); |
948 | res = (struct dentry *)inode; |
949 | if (IS_ERR(res)) |
950 | goto out_unblock_sillyrename; |
951 | |
952 | no_entry: |
953 | res = d_materialise_unique(dentry, inode); |
954 | if (res != NULL) { |
955 | if (IS_ERR(res)) |
956 | goto out_unblock_sillyrename; |
957 | dentry = res; |
958 | } |
959 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
960 | out_unblock_sillyrename: |
961 | nfs_unblock_sillyrename(parent); |
962 | out: |
963 | return res; |
964 | } |
965 | |
966 | #ifdef CONFIG_NFS_V4 |
967 | static int nfs_open_revalidate(struct dentry *, struct nameidata *); |
968 | |
969 | const struct dentry_operations nfs4_dentry_operations = { |
970 | .d_revalidate = nfs_open_revalidate, |
971 | .d_delete = nfs_dentry_delete, |
972 | .d_iput = nfs_dentry_iput, |
973 | }; |
974 | |
975 | /* |
976 | * Use intent information to determine whether we need to substitute |
977 | * the NFSv4-style stateful OPEN for the LOOKUP call |
978 | */ |
979 | static int is_atomic_open(struct nameidata *nd) |
980 | { |
981 | if (nd == NULL || nfs_lookup_check_intent(nd, LOOKUP_OPEN) == 0) |
982 | return 0; |
983 | /* NFS does not (yet) have a stateful open for directories */ |
984 | if (nd->flags & LOOKUP_DIRECTORY) |
985 | return 0; |
986 | /* Are we trying to write to a read only partition? */ |
987 | if (__mnt_is_readonly(nd->path.mnt) && |
988 | (nd->intent.open.flags & (O_CREAT|O_TRUNC|FMODE_WRITE))) |
989 | return 0; |
990 | return 1; |
991 | } |
992 | |
993 | static struct dentry *nfs_atomic_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) |
994 | { |
995 | struct dentry *res = NULL; |
996 | int error; |
997 | |
998 | dfprintk(VFS, "NFS: atomic_lookup(%s/%ld), %s\n", |
999 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1000 | |
1001 | /* Check that we are indeed trying to open this file */ |
1002 | if (!is_atomic_open(nd)) |
1003 | goto no_open; |
1004 | |
1005 | if (dentry->d_name.len > NFS_SERVER(dir)->namelen) { |
1006 | res = ERR_PTR(-ENAMETOOLONG); |
1007 | goto out; |
1008 | } |
1009 | dentry->d_op = NFS_PROTO(dir)->dentry_ops; |
1010 | |
1011 | /* Let vfs_create() deal with O_EXCL. Instantiate, but don't hash |
1012 | * the dentry. */ |
1013 | if (nd->flags & LOOKUP_EXCL) { |
1014 | d_instantiate(dentry, NULL); |
1015 | goto out; |
1016 | } |
1017 | |
1018 | /* Open the file on the server */ |
1019 | res = nfs4_atomic_open(dir, dentry, nd); |
1020 | if (IS_ERR(res)) { |
1021 | error = PTR_ERR(res); |
1022 | switch (error) { |
1023 | /* Make a negative dentry */ |
1024 | case -ENOENT: |
1025 | res = NULL; |
1026 | goto out; |
1027 | /* This turned out not to be a regular file */ |
1028 | case -ENOTDIR: |
1029 | goto no_open; |
1030 | case -ELOOP: |
1031 | if (!(nd->intent.open.flags & O_NOFOLLOW)) |
1032 | goto no_open; |
1033 | /* case -EISDIR: */ |
1034 | /* case -EINVAL: */ |
1035 | default: |
1036 | goto out; |
1037 | } |
1038 | } else if (res != NULL) |
1039 | dentry = res; |
1040 | out: |
1041 | return res; |
1042 | no_open: |
1043 | return nfs_lookup(dir, dentry, nd); |
1044 | } |
1045 | |
1046 | static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd) |
1047 | { |
1048 | struct dentry *parent = NULL; |
1049 | struct inode *inode = dentry->d_inode; |
1050 | struct inode *dir; |
1051 | int openflags, ret = 0; |
1052 | |
1053 | if (!is_atomic_open(nd)) |
1054 | goto no_open; |
1055 | parent = dget_parent(dentry); |
1056 | dir = parent->d_inode; |
1057 | /* We can't create new files in nfs_open_revalidate(), so we |
1058 | * optimize away revalidation of negative dentries. |
1059 | */ |
1060 | if (inode == NULL) { |
1061 | if (!nfs_neg_need_reval(dir, dentry, nd)) |
1062 | ret = 1; |
1063 | goto out; |
1064 | } |
1065 | |
1066 | /* NFS only supports OPEN on regular files */ |
1067 | if (!S_ISREG(inode->i_mode)) |
1068 | goto no_open_dput; |
1069 | openflags = nd->intent.open.flags; |
1070 | /* We cannot do exclusive creation on a positive dentry */ |
1071 | if ((openflags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL)) |
1072 | goto no_open_dput; |
1073 | /* We can't create new files, or truncate existing ones here */ |
1074 | openflags &= ~(O_CREAT|O_TRUNC); |
1075 | |
1076 | /* |
1077 | * Note: we're not holding inode->i_mutex and so may be racing with |
1078 | * operations that change the directory. We therefore save the |
1079 | * change attribute *before* we do the RPC call. |
1080 | */ |
1081 | ret = nfs4_open_revalidate(dir, dentry, openflags, nd); |
1082 | out: |
1083 | dput(parent); |
1084 | if (!ret) |
1085 | d_drop(dentry); |
1086 | return ret; |
1087 | no_open_dput: |
1088 | dput(parent); |
1089 | no_open: |
1090 | return nfs_lookup_revalidate(dentry, nd); |
1091 | } |
1092 | #endif /* CONFIG_NFSV4 */ |
1093 | |
1094 | static struct dentry *nfs_readdir_lookup(nfs_readdir_descriptor_t *desc) |
1095 | { |
1096 | struct dentry *parent = desc->file->f_path.dentry; |
1097 | struct inode *dir = parent->d_inode; |
1098 | struct nfs_entry *entry = desc->entry; |
1099 | struct dentry *dentry, *alias; |
1100 | struct qstr name = { |
1101 | .name = entry->name, |
1102 | .len = entry->len, |
1103 | }; |
1104 | struct inode *inode; |
1105 | unsigned long verf = nfs_save_change_attribute(dir); |
1106 | |
1107 | switch (name.len) { |
1108 | case 2: |
1109 | if (name.name[0] == '.' && name.name[1] == '.') |
1110 | return dget_parent(parent); |
1111 | break; |
1112 | case 1: |
1113 | if (name.name[0] == '.') |
1114 | return dget(parent); |
1115 | } |
1116 | |
1117 | spin_lock(&dir->i_lock); |
1118 | if (NFS_I(dir)->cache_validity & NFS_INO_INVALID_DATA) { |
1119 | spin_unlock(&dir->i_lock); |
1120 | return NULL; |
1121 | } |
1122 | spin_unlock(&dir->i_lock); |
1123 | |
1124 | name.hash = full_name_hash(name.name, name.len); |
1125 | dentry = d_lookup(parent, &name); |
1126 | if (dentry != NULL) { |
1127 | /* Is this a positive dentry that matches the readdir info? */ |
1128 | if (dentry->d_inode != NULL && |
1129 | (NFS_FILEID(dentry->d_inode) == entry->ino || |
1130 | d_mountpoint(dentry))) { |
1131 | if (!desc->plus || entry->fh->size == 0) |
1132 | return dentry; |
1133 | if (nfs_compare_fh(NFS_FH(dentry->d_inode), |
1134 | entry->fh) == 0) |
1135 | goto out_renew; |
1136 | } |
1137 | /* No, so d_drop to allow one to be created */ |
1138 | d_drop(dentry); |
1139 | dput(dentry); |
1140 | } |
1141 | if (!desc->plus || !(entry->fattr->valid & NFS_ATTR_FATTR)) |
1142 | return NULL; |
1143 | if (name.len > NFS_SERVER(dir)->namelen) |
1144 | return NULL; |
1145 | /* Note: caller is already holding the dir->i_mutex! */ |
1146 | dentry = d_alloc(parent, &name); |
1147 | if (dentry == NULL) |
1148 | return NULL; |
1149 | dentry->d_op = NFS_PROTO(dir)->dentry_ops; |
1150 | inode = nfs_fhget(dentry->d_sb, entry->fh, entry->fattr); |
1151 | if (IS_ERR(inode)) { |
1152 | dput(dentry); |
1153 | return NULL; |
1154 | } |
1155 | |
1156 | alias = d_materialise_unique(dentry, inode); |
1157 | if (alias != NULL) { |
1158 | dput(dentry); |
1159 | if (IS_ERR(alias)) |
1160 | return NULL; |
1161 | dentry = alias; |
1162 | } |
1163 | |
1164 | out_renew: |
1165 | nfs_set_verifier(dentry, verf); |
1166 | return dentry; |
1167 | } |
1168 | |
1169 | /* |
1170 | * Code common to create, mkdir, and mknod. |
1171 | */ |
1172 | int nfs_instantiate(struct dentry *dentry, struct nfs_fh *fhandle, |
1173 | struct nfs_fattr *fattr) |
1174 | { |
1175 | struct dentry *parent = dget_parent(dentry); |
1176 | struct inode *dir = parent->d_inode; |
1177 | struct inode *inode; |
1178 | int error = -EACCES; |
1179 | |
1180 | d_drop(dentry); |
1181 | |
1182 | /* We may have been initialized further down */ |
1183 | if (dentry->d_inode) |
1184 | goto out; |
1185 | if (fhandle->size == 0) { |
1186 | error = NFS_PROTO(dir)->lookup(dir, &dentry->d_name, fhandle, fattr); |
1187 | if (error) |
1188 | goto out_error; |
1189 | } |
1190 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1191 | if (!(fattr->valid & NFS_ATTR_FATTR)) { |
1192 | struct nfs_server *server = NFS_SB(dentry->d_sb); |
1193 | error = server->nfs_client->rpc_ops->getattr(server, fhandle, fattr); |
1194 | if (error < 0) |
1195 | goto out_error; |
1196 | } |
1197 | inode = nfs_fhget(dentry->d_sb, fhandle, fattr); |
1198 | error = PTR_ERR(inode); |
1199 | if (IS_ERR(inode)) |
1200 | goto out_error; |
1201 | d_add(dentry, inode); |
1202 | out: |
1203 | dput(parent); |
1204 | return 0; |
1205 | out_error: |
1206 | nfs_mark_for_revalidate(dir); |
1207 | dput(parent); |
1208 | return error; |
1209 | } |
1210 | |
1211 | /* |
1212 | * Following a failed create operation, we drop the dentry rather |
1213 | * than retain a negative dentry. This avoids a problem in the event |
1214 | * that the operation succeeded on the server, but an error in the |
1215 | * reply path made it appear to have failed. |
1216 | */ |
1217 | static int nfs_create(struct inode *dir, struct dentry *dentry, int mode, |
1218 | struct nameidata *nd) |
1219 | { |
1220 | struct iattr attr; |
1221 | int error; |
1222 | int open_flags = 0; |
1223 | |
1224 | dfprintk(VFS, "NFS: create(%s/%ld), %s\n", |
1225 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1226 | |
1227 | attr.ia_mode = mode; |
1228 | attr.ia_valid = ATTR_MODE; |
1229 | |
1230 | if ((nd->flags & LOOKUP_CREATE) != 0) |
1231 | open_flags = nd->intent.open.flags; |
1232 | |
1233 | error = NFS_PROTO(dir)->create(dir, dentry, &attr, open_flags, nd); |
1234 | if (error != 0) |
1235 | goto out_err; |
1236 | return 0; |
1237 | out_err: |
1238 | d_drop(dentry); |
1239 | return error; |
1240 | } |
1241 | |
1242 | /* |
1243 | * See comments for nfs_proc_create regarding failed operations. |
1244 | */ |
1245 | static int |
1246 | nfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev) |
1247 | { |
1248 | struct iattr attr; |
1249 | int status; |
1250 | |
1251 | dfprintk(VFS, "NFS: mknod(%s/%ld), %s\n", |
1252 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1253 | |
1254 | if (!new_valid_dev(rdev)) |
1255 | return -EINVAL; |
1256 | |
1257 | attr.ia_mode = mode; |
1258 | attr.ia_valid = ATTR_MODE; |
1259 | |
1260 | status = NFS_PROTO(dir)->mknod(dir, dentry, &attr, rdev); |
1261 | if (status != 0) |
1262 | goto out_err; |
1263 | return 0; |
1264 | out_err: |
1265 | d_drop(dentry); |
1266 | return status; |
1267 | } |
1268 | |
1269 | /* |
1270 | * See comments for nfs_proc_create regarding failed operations. |
1271 | */ |
1272 | static int nfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) |
1273 | { |
1274 | struct iattr attr; |
1275 | int error; |
1276 | |
1277 | dfprintk(VFS, "NFS: mkdir(%s/%ld), %s\n", |
1278 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1279 | |
1280 | attr.ia_valid = ATTR_MODE; |
1281 | attr.ia_mode = mode | S_IFDIR; |
1282 | |
1283 | error = NFS_PROTO(dir)->mkdir(dir, dentry, &attr); |
1284 | if (error != 0) |
1285 | goto out_err; |
1286 | return 0; |
1287 | out_err: |
1288 | d_drop(dentry); |
1289 | return error; |
1290 | } |
1291 | |
1292 | static void nfs_dentry_handle_enoent(struct dentry *dentry) |
1293 | { |
1294 | if (dentry->d_inode != NULL && !d_unhashed(dentry)) |
1295 | d_delete(dentry); |
1296 | } |
1297 | |
1298 | static int nfs_rmdir(struct inode *dir, struct dentry *dentry) |
1299 | { |
1300 | int error; |
1301 | |
1302 | dfprintk(VFS, "NFS: rmdir(%s/%ld), %s\n", |
1303 | dir->i_sb->s_id, dir->i_ino, dentry->d_name.name); |
1304 | |
1305 | error = NFS_PROTO(dir)->rmdir(dir, &dentry->d_name); |
1306 | /* Ensure the VFS deletes this inode */ |
1307 | if (error == 0 && dentry->d_inode != NULL) |
1308 | clear_nlink(dentry->d_inode); |
1309 | else if (error == -ENOENT) |
1310 | nfs_dentry_handle_enoent(dentry); |
1311 | |
1312 | return error; |
1313 | } |
1314 | |
1315 | static int nfs_sillyrename(struct inode *dir, struct dentry *dentry) |
1316 | { |
1317 | static unsigned int sillycounter; |
1318 | const int fileidsize = sizeof(NFS_FILEID(dentry->d_inode))*2; |
1319 | const int countersize = sizeof(sillycounter)*2; |
1320 | const int slen = sizeof(".nfs")+fileidsize+countersize-1; |
1321 | char silly[slen+1]; |
1322 | struct qstr qsilly; |
1323 | struct dentry *sdentry; |
1324 | int error = -EIO; |
1325 | |
1326 | dfprintk(VFS, "NFS: silly-rename(%s/%s, ct=%d)\n", |
1327 | dentry->d_parent->d_name.name, dentry->d_name.name, |
1328 | atomic_read(&dentry->d_count)); |
1329 | nfs_inc_stats(dir, NFSIOS_SILLYRENAME); |
1330 | |
1331 | /* |
1332 | * We don't allow a dentry to be silly-renamed twice. |
1333 | */ |
1334 | error = -EBUSY; |
1335 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) |
1336 | goto out; |
1337 | |
1338 | sprintf(silly, ".nfs%*.*Lx", |
1339 | fileidsize, fileidsize, |
1340 | (unsigned long long)NFS_FILEID(dentry->d_inode)); |
1341 | |
1342 | /* Return delegation in anticipation of the rename */ |
1343 | nfs_inode_return_delegation(dentry->d_inode); |
1344 | |
1345 | sdentry = NULL; |
1346 | do { |
1347 | char *suffix = silly + slen - countersize; |
1348 | |
1349 | dput(sdentry); |
1350 | sillycounter++; |
1351 | sprintf(suffix, "%*.*x", countersize, countersize, sillycounter); |
1352 | |
1353 | dfprintk(VFS, "NFS: trying to rename %s to %s\n", |
1354 | dentry->d_name.name, silly); |
1355 | |
1356 | sdentry = lookup_one_len(silly, dentry->d_parent, slen); |
1357 | /* |
1358 | * N.B. Better to return EBUSY here ... it could be |
1359 | * dangerous to delete the file while it's in use. |
1360 | */ |
1361 | if (IS_ERR(sdentry)) |
1362 | goto out; |
1363 | } while(sdentry->d_inode != NULL); /* need negative lookup */ |
1364 | |
1365 | qsilly.name = silly; |
1366 | qsilly.len = strlen(silly); |
1367 | if (dentry->d_inode) { |
1368 | error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, |
1369 | dir, &qsilly); |
1370 | nfs_mark_for_revalidate(dentry->d_inode); |
1371 | } else |
1372 | error = NFS_PROTO(dir)->rename(dir, &dentry->d_name, |
1373 | dir, &qsilly); |
1374 | if (!error) { |
1375 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1376 | d_move(dentry, sdentry); |
1377 | error = nfs_async_unlink(dir, dentry); |
1378 | /* If we return 0 we don't unlink */ |
1379 | } |
1380 | dput(sdentry); |
1381 | out: |
1382 | return error; |
1383 | } |
1384 | |
1385 | /* |
1386 | * Remove a file after making sure there are no pending writes, |
1387 | * and after checking that the file has only one user. |
1388 | * |
1389 | * We invalidate the attribute cache and free the inode prior to the operation |
1390 | * to avoid possible races if the server reuses the inode. |
1391 | */ |
1392 | static int nfs_safe_remove(struct dentry *dentry) |
1393 | { |
1394 | struct inode *dir = dentry->d_parent->d_inode; |
1395 | struct inode *inode = dentry->d_inode; |
1396 | int error = -EBUSY; |
1397 | |
1398 | dfprintk(VFS, "NFS: safe_remove(%s/%s)\n", |
1399 | dentry->d_parent->d_name.name, dentry->d_name.name); |
1400 | |
1401 | /* If the dentry was sillyrenamed, we simply call d_delete() */ |
1402 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { |
1403 | error = 0; |
1404 | goto out; |
1405 | } |
1406 | |
1407 | if (inode != NULL) { |
1408 | nfs_inode_return_delegation(inode); |
1409 | error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); |
1410 | /* The VFS may want to delete this inode */ |
1411 | if (error == 0) |
1412 | nfs_drop_nlink(inode); |
1413 | nfs_mark_for_revalidate(inode); |
1414 | } else |
1415 | error = NFS_PROTO(dir)->remove(dir, &dentry->d_name); |
1416 | if (error == -ENOENT) |
1417 | nfs_dentry_handle_enoent(dentry); |
1418 | out: |
1419 | return error; |
1420 | } |
1421 | |
1422 | /* We do silly rename. In case sillyrename() returns -EBUSY, the inode |
1423 | * belongs to an active ".nfs..." file and we return -EBUSY. |
1424 | * |
1425 | * If sillyrename() returns 0, we do nothing, otherwise we unlink. |
1426 | */ |
1427 | static int nfs_unlink(struct inode *dir, struct dentry *dentry) |
1428 | { |
1429 | int error; |
1430 | int need_rehash = 0; |
1431 | |
1432 | dfprintk(VFS, "NFS: unlink(%s/%ld, %s)\n", dir->i_sb->s_id, |
1433 | dir->i_ino, dentry->d_name.name); |
1434 | |
1435 | spin_lock(&dcache_lock); |
1436 | spin_lock(&dentry->d_lock); |
1437 | if (atomic_read(&dentry->d_count) > 1) { |
1438 | spin_unlock(&dentry->d_lock); |
1439 | spin_unlock(&dcache_lock); |
1440 | /* Start asynchronous writeout of the inode */ |
1441 | write_inode_now(dentry->d_inode, 0); |
1442 | error = nfs_sillyrename(dir, dentry); |
1443 | return error; |
1444 | } |
1445 | if (!d_unhashed(dentry)) { |
1446 | __d_drop(dentry); |
1447 | need_rehash = 1; |
1448 | } |
1449 | spin_unlock(&dentry->d_lock); |
1450 | spin_unlock(&dcache_lock); |
1451 | error = nfs_safe_remove(dentry); |
1452 | if (!error || error == -ENOENT) { |
1453 | nfs_set_verifier(dentry, nfs_save_change_attribute(dir)); |
1454 | } else if (need_rehash) |
1455 | d_rehash(dentry); |
1456 | return error; |
1457 | } |
1458 | |
1459 | /* |
1460 | * To create a symbolic link, most file systems instantiate a new inode, |
1461 | * add a page to it containing the path, then write it out to the disk |
1462 | * using prepare_write/commit_write. |
1463 | * |
1464 | * Unfortunately the NFS client can't create the in-core inode first |
1465 | * because it needs a file handle to create an in-core inode (see |
1466 | * fs/nfs/inode.c:nfs_fhget). We only have a file handle *after* the |
1467 | * symlink request has completed on the server. |
1468 | * |
1469 | * So instead we allocate a raw page, copy the symname into it, then do |
1470 | * the SYMLINK request with the page as the buffer. If it succeeds, we |
1471 | * now have a new file handle and can instantiate an in-core NFS inode |
1472 | * and move the raw page into its mapping. |
1473 | */ |
1474 | static int nfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) |
1475 | { |
1476 | struct pagevec lru_pvec; |
1477 | struct page *page; |
1478 | char *kaddr; |
1479 | struct iattr attr; |
1480 | unsigned int pathlen = strlen(symname); |
1481 | int error; |
1482 | |
1483 | dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s)\n", dir->i_sb->s_id, |
1484 | dir->i_ino, dentry->d_name.name, symname); |
1485 | |
1486 | if (pathlen > PAGE_SIZE) |
1487 | return -ENAMETOOLONG; |
1488 | |
1489 | attr.ia_mode = S_IFLNK | S_IRWXUGO; |
1490 | attr.ia_valid = ATTR_MODE; |
1491 | |
1492 | page = alloc_page(GFP_HIGHUSER); |
1493 | if (!page) |
1494 | return -ENOMEM; |
1495 | |
1496 | kaddr = kmap_atomic(page, KM_USER0); |
1497 | memcpy(kaddr, symname, pathlen); |
1498 | if (pathlen < PAGE_SIZE) |
1499 | memset(kaddr + pathlen, 0, PAGE_SIZE - pathlen); |
1500 | kunmap_atomic(kaddr, KM_USER0); |
1501 | |
1502 | error = NFS_PROTO(dir)->symlink(dir, dentry, page, pathlen, &attr); |
1503 | if (error != 0) { |
1504 | dfprintk(VFS, "NFS: symlink(%s/%ld, %s, %s) error %d\n", |
1505 | dir->i_sb->s_id, dir->i_ino, |
1506 | dentry->d_name.name, symname, error); |
1507 | d_drop(dentry); |
1508 | __free_page(page); |
1509 | return error; |
1510 | } |
1511 | |
1512 | /* |
1513 | * No big deal if we can't add this page to the page cache here. |
1514 | * READLINK will get the missing page from the server if needed. |
1515 | */ |
1516 | pagevec_init(&lru_pvec, 0); |
1517 | if (!add_to_page_cache(page, dentry->d_inode->i_mapping, 0, |
1518 | GFP_KERNEL)) { |
1519 | pagevec_add(&lru_pvec, page); |
1520 | pagevec_lru_add_file(&lru_pvec); |
1521 | SetPageUptodate(page); |
1522 | unlock_page(page); |
1523 | } else |
1524 | __free_page(page); |
1525 | |
1526 | return 0; |
1527 | } |
1528 | |
1529 | static int |
1530 | nfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) |
1531 | { |
1532 | struct inode *inode = old_dentry->d_inode; |
1533 | int error; |
1534 | |
1535 | dfprintk(VFS, "NFS: link(%s/%s -> %s/%s)\n", |
1536 | old_dentry->d_parent->d_name.name, old_dentry->d_name.name, |
1537 | dentry->d_parent->d_name.name, dentry->d_name.name); |
1538 | |
1539 | d_drop(dentry); |
1540 | error = NFS_PROTO(dir)->link(inode, dir, &dentry->d_name); |
1541 | if (error == 0) { |
1542 | atomic_inc(&inode->i_count); |
1543 | d_add(dentry, inode); |
1544 | } |
1545 | return error; |
1546 | } |
1547 | |
1548 | /* |
1549 | * RENAME |
1550 | * FIXME: Some nfsds, like the Linux user space nfsd, may generate a |
1551 | * different file handle for the same inode after a rename (e.g. when |
1552 | * moving to a different directory). A fail-safe method to do so would |
1553 | * be to look up old_dir/old_name, create a link to new_dir/new_name and |
1554 | * rename the old file using the sillyrename stuff. This way, the original |
1555 | * file in old_dir will go away when the last process iput()s the inode. |
1556 | * |
1557 | * FIXED. |
1558 | * |
1559 | * It actually works quite well. One needs to have the possibility for |
1560 | * at least one ".nfs..." file in each directory the file ever gets |
1561 | * moved or linked to which happens automagically with the new |
1562 | * implementation that only depends on the dcache stuff instead of |
1563 | * using the inode layer |
1564 | * |
1565 | * Unfortunately, things are a little more complicated than indicated |
1566 | * above. For a cross-directory move, we want to make sure we can get |
1567 | * rid of the old inode after the operation. This means there must be |
1568 | * no pending writes (if it's a file), and the use count must be 1. |
1569 | * If these conditions are met, we can drop the dentries before doing |
1570 | * the rename. |
1571 | */ |
1572 | static int nfs_rename(struct inode *old_dir, struct dentry *old_dentry, |
1573 | struct inode *new_dir, struct dentry *new_dentry) |
1574 | { |
1575 | struct inode *old_inode = old_dentry->d_inode; |
1576 | struct inode *new_inode = new_dentry->d_inode; |
1577 | struct dentry *dentry = NULL, *rehash = NULL; |
1578 | int error = -EBUSY; |
1579 | |
1580 | /* |
1581 | * To prevent any new references to the target during the rename, |
1582 | * we unhash the dentry and free the inode in advance. |
1583 | */ |
1584 | if (!d_unhashed(new_dentry)) { |
1585 | d_drop(new_dentry); |
1586 | rehash = new_dentry; |
1587 | } |
1588 | |
1589 | dfprintk(VFS, "NFS: rename(%s/%s -> %s/%s, ct=%d)\n", |
1590 | old_dentry->d_parent->d_name.name, old_dentry->d_name.name, |
1591 | new_dentry->d_parent->d_name.name, new_dentry->d_name.name, |
1592 | atomic_read(&new_dentry->d_count)); |
1593 | |
1594 | /* |
1595 | * First check whether the target is busy ... we can't |
1596 | * safely do _any_ rename if the target is in use. |
1597 | * |
1598 | * For files, make a copy of the dentry and then do a |
1599 | * silly-rename. If the silly-rename succeeds, the |
1600 | * copied dentry is hashed and becomes the new target. |
1601 | */ |
1602 | if (!new_inode) |
1603 | goto go_ahead; |
1604 | if (S_ISDIR(new_inode->i_mode)) { |
1605 | error = -EISDIR; |
1606 | if (!S_ISDIR(old_inode->i_mode)) |
1607 | goto out; |
1608 | } else if (atomic_read(&new_dentry->d_count) > 2) { |
1609 | int err; |
1610 | /* copy the target dentry's name */ |
1611 | dentry = d_alloc(new_dentry->d_parent, |
1612 | &new_dentry->d_name); |
1613 | if (!dentry) |
1614 | goto out; |
1615 | |
1616 | /* silly-rename the existing target ... */ |
1617 | err = nfs_sillyrename(new_dir, new_dentry); |
1618 | if (!err) { |
1619 | new_dentry = rehash = dentry; |
1620 | new_inode = NULL; |
1621 | /* instantiate the replacement target */ |
1622 | d_instantiate(new_dentry, NULL); |
1623 | } else if (atomic_read(&new_dentry->d_count) > 1) |
1624 | /* dentry still busy? */ |
1625 | goto out; |
1626 | } |
1627 | |
1628 | go_ahead: |
1629 | /* |
1630 | * ... prune child dentries and writebacks if needed. |
1631 | */ |
1632 | if (atomic_read(&old_dentry->d_count) > 1) { |
1633 | if (S_ISREG(old_inode->i_mode)) |
1634 | nfs_wb_all(old_inode); |
1635 | shrink_dcache_parent(old_dentry); |
1636 | } |
1637 | nfs_inode_return_delegation(old_inode); |
1638 | |
1639 | if (new_inode != NULL) |
1640 | nfs_inode_return_delegation(new_inode); |
1641 | |
1642 | error = NFS_PROTO(old_dir)->rename(old_dir, &old_dentry->d_name, |
1643 | new_dir, &new_dentry->d_name); |
1644 | nfs_mark_for_revalidate(old_inode); |
1645 | out: |
1646 | if (rehash) |
1647 | d_rehash(rehash); |
1648 | if (!error) { |
1649 | if (new_inode != NULL) |
1650 | nfs_drop_nlink(new_inode); |
1651 | d_move(old_dentry, new_dentry); |
1652 | nfs_set_verifier(new_dentry, |
1653 | nfs_save_change_attribute(new_dir)); |
1654 | } else if (error == -ENOENT) |
1655 | nfs_dentry_handle_enoent(old_dentry); |
1656 | |
1657 | /* new dentry created? */ |
1658 | if (dentry) |
1659 | dput(dentry); |
1660 | return error; |
1661 | } |
1662 | |
1663 | static DEFINE_SPINLOCK(nfs_access_lru_lock); |
1664 | static LIST_HEAD(nfs_access_lru_list); |
1665 | static atomic_long_t nfs_access_nr_entries; |
1666 | |
1667 | static void nfs_access_free_entry(struct nfs_access_entry *entry) |
1668 | { |
1669 | put_rpccred(entry->cred); |
1670 | kfree(entry); |
1671 | smp_mb__before_atomic_dec(); |
1672 | atomic_long_dec(&nfs_access_nr_entries); |
1673 | smp_mb__after_atomic_dec(); |
1674 | } |
1675 | |
1676 | int nfs_access_cache_shrinker(int nr_to_scan, gfp_t gfp_mask) |
1677 | { |
1678 | LIST_HEAD(head); |
1679 | struct nfs_inode *nfsi; |
1680 | struct nfs_access_entry *cache; |
1681 | |
1682 | restart: |
1683 | spin_lock(&nfs_access_lru_lock); |
1684 | list_for_each_entry(nfsi, &nfs_access_lru_list, access_cache_inode_lru) { |
1685 | struct rw_semaphore *s_umount; |
1686 | struct inode *inode; |
1687 | |
1688 | if (nr_to_scan-- == 0) |
1689 | break; |
1690 | s_umount = &nfsi->vfs_inode.i_sb->s_umount; |
1691 | if (!down_read_trylock(s_umount)) |
1692 | continue; |
1693 | inode = igrab(&nfsi->vfs_inode); |
1694 | if (inode == NULL) { |
1695 | up_read(s_umount); |
1696 | continue; |
1697 | } |
1698 | spin_lock(&inode->i_lock); |
1699 | if (list_empty(&nfsi->access_cache_entry_lru)) |
1700 | goto remove_lru_entry; |
1701 | cache = list_entry(nfsi->access_cache_entry_lru.next, |
1702 | struct nfs_access_entry, lru); |
1703 | list_move(&cache->lru, &head); |
1704 | rb_erase(&cache->rb_node, &nfsi->access_cache); |
1705 | if (!list_empty(&nfsi->access_cache_entry_lru)) |
1706 | list_move_tail(&nfsi->access_cache_inode_lru, |
1707 | &nfs_access_lru_list); |
1708 | else { |
1709 | remove_lru_entry: |
1710 | list_del_init(&nfsi->access_cache_inode_lru); |
1711 | clear_bit(NFS_INO_ACL_LRU_SET, &nfsi->flags); |
1712 | } |
1713 | spin_unlock(&inode->i_lock); |
1714 | spin_unlock(&nfs_access_lru_lock); |
1715 | iput(inode); |
1716 | up_read(s_umount); |
1717 | goto restart; |
1718 | } |
1719 | spin_unlock(&nfs_access_lru_lock); |
1720 | while (!list_empty(&head)) { |
1721 | cache = list_entry(head.next, struct nfs_access_entry, lru); |
1722 | list_del(&cache->lru); |
1723 | nfs_access_free_entry(cache); |
1724 | } |
1725 | return (atomic_long_read(&nfs_access_nr_entries) / 100) * sysctl_vfs_cache_pressure; |
1726 | } |
1727 | |
1728 | static void __nfs_access_zap_cache(struct inode *inode) |
1729 | { |
1730 | struct nfs_inode *nfsi = NFS_I(inode); |
1731 | struct rb_root *root_node = &nfsi->access_cache; |
1732 | struct rb_node *n, *dispose = NULL; |
1733 | struct nfs_access_entry *entry; |
1734 | |
1735 | /* Unhook entries from the cache */ |
1736 | while ((n = rb_first(root_node)) != NULL) { |
1737 | entry = rb_entry(n, struct nfs_access_entry, rb_node); |
1738 | rb_erase(n, root_node); |
1739 | list_del(&entry->lru); |
1740 | n->rb_left = dispose; |
1741 | dispose = n; |
1742 | } |
1743 | nfsi->cache_validity &= ~NFS_INO_INVALID_ACCESS; |
1744 | spin_unlock(&inode->i_lock); |
1745 | |
1746 | /* Now kill them all! */ |
1747 | while (dispose != NULL) { |
1748 | n = dispose; |
1749 | dispose = n->rb_left; |
1750 | nfs_access_free_entry(rb_entry(n, struct nfs_access_entry, rb_node)); |
1751 | } |
1752 | } |
1753 | |
1754 | void nfs_access_zap_cache(struct inode *inode) |
1755 | { |
1756 | /* Remove from global LRU init */ |
1757 | if (test_and_clear_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { |
1758 | spin_lock(&nfs_access_lru_lock); |
1759 | list_del_init(&NFS_I(inode)->access_cache_inode_lru); |
1760 | spin_unlock(&nfs_access_lru_lock); |
1761 | } |
1762 | |
1763 | spin_lock(&inode->i_lock); |
1764 | /* This will release the spinlock */ |
1765 | __nfs_access_zap_cache(inode); |
1766 | } |
1767 | |
1768 | static struct nfs_access_entry *nfs_access_search_rbtree(struct inode *inode, struct rpc_cred *cred) |
1769 | { |
1770 | struct rb_node *n = NFS_I(inode)->access_cache.rb_node; |
1771 | struct nfs_access_entry *entry; |
1772 | |
1773 | while (n != NULL) { |
1774 | entry = rb_entry(n, struct nfs_access_entry, rb_node); |
1775 | |
1776 | if (cred < entry->cred) |
1777 | n = n->rb_left; |
1778 | else if (cred > entry->cred) |
1779 | n = n->rb_right; |
1780 | else |
1781 | return entry; |
1782 | } |
1783 | return NULL; |
1784 | } |
1785 | |
1786 | static int nfs_access_get_cached(struct inode *inode, struct rpc_cred *cred, struct nfs_access_entry *res) |
1787 | { |
1788 | struct nfs_inode *nfsi = NFS_I(inode); |
1789 | struct nfs_access_entry *cache; |
1790 | int err = -ENOENT; |
1791 | |
1792 | spin_lock(&inode->i_lock); |
1793 | if (nfsi->cache_validity & NFS_INO_INVALID_ACCESS) |
1794 | goto out_zap; |
1795 | cache = nfs_access_search_rbtree(inode, cred); |
1796 | if (cache == NULL) |
1797 | goto out; |
1798 | if (!nfs_have_delegation(inode, FMODE_READ) && |
1799 | !time_in_range_open(jiffies, cache->jiffies, cache->jiffies + nfsi->attrtimeo)) |
1800 | goto out_stale; |
1801 | res->jiffies = cache->jiffies; |
1802 | res->cred = cache->cred; |
1803 | res->mask = cache->mask; |
1804 | list_move_tail(&cache->lru, &nfsi->access_cache_entry_lru); |
1805 | err = 0; |
1806 | out: |
1807 | spin_unlock(&inode->i_lock); |
1808 | return err; |
1809 | out_stale: |
1810 | rb_erase(&cache->rb_node, &nfsi->access_cache); |
1811 | list_del(&cache->lru); |
1812 | spin_unlock(&inode->i_lock); |
1813 | nfs_access_free_entry(cache); |
1814 | return -ENOENT; |
1815 | out_zap: |
1816 | /* This will release the spinlock */ |
1817 | __nfs_access_zap_cache(inode); |
1818 | return -ENOENT; |
1819 | } |
1820 | |
1821 | static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) |
1822 | { |
1823 | struct nfs_inode *nfsi = NFS_I(inode); |
1824 | struct rb_root *root_node = &nfsi->access_cache; |
1825 | struct rb_node **p = &root_node->rb_node; |
1826 | struct rb_node *parent = NULL; |
1827 | struct nfs_access_entry *entry; |
1828 | |
1829 | spin_lock(&inode->i_lock); |
1830 | while (*p != NULL) { |
1831 | parent = *p; |
1832 | entry = rb_entry(parent, struct nfs_access_entry, rb_node); |
1833 | |
1834 | if (set->cred < entry->cred) |
1835 | p = &parent->rb_left; |
1836 | else if (set->cred > entry->cred) |
1837 | p = &parent->rb_right; |
1838 | else |
1839 | goto found; |
1840 | } |
1841 | rb_link_node(&set->rb_node, parent, p); |
1842 | rb_insert_color(&set->rb_node, root_node); |
1843 | list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); |
1844 | spin_unlock(&inode->i_lock); |
1845 | return; |
1846 | found: |
1847 | rb_replace_node(parent, &set->rb_node, root_node); |
1848 | list_add_tail(&set->lru, &nfsi->access_cache_entry_lru); |
1849 | list_del(&entry->lru); |
1850 | spin_unlock(&inode->i_lock); |
1851 | nfs_access_free_entry(entry); |
1852 | } |
1853 | |
1854 | static void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) |
1855 | { |
1856 | struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); |
1857 | if (cache == NULL) |
1858 | return; |
1859 | RB_CLEAR_NODE(&cache->rb_node); |
1860 | cache->jiffies = set->jiffies; |
1861 | cache->cred = get_rpccred(set->cred); |
1862 | cache->mask = set->mask; |
1863 | |
1864 | nfs_access_add_rbtree(inode, cache); |
1865 | |
1866 | /* Update accounting */ |
1867 | smp_mb__before_atomic_inc(); |
1868 | atomic_long_inc(&nfs_access_nr_entries); |
1869 | smp_mb__after_atomic_inc(); |
1870 | |
1871 | /* Add inode to global LRU list */ |
1872 | if (!test_and_set_bit(NFS_INO_ACL_LRU_SET, &NFS_I(inode)->flags)) { |
1873 | spin_lock(&nfs_access_lru_lock); |
1874 | list_add_tail(&NFS_I(inode)->access_cache_inode_lru, &nfs_access_lru_list); |
1875 | spin_unlock(&nfs_access_lru_lock); |
1876 | } |
1877 | } |
1878 | |
1879 | static int nfs_do_access(struct inode *inode, struct rpc_cred *cred, int mask) |
1880 | { |
1881 | struct nfs_access_entry cache; |
1882 | int status; |
1883 | |
1884 | status = nfs_access_get_cached(inode, cred, &cache); |
1885 | if (status == 0) |
1886 | goto out; |
1887 | |
1888 | /* Be clever: ask server to check for all possible rights */ |
1889 | cache.mask = MAY_EXEC | MAY_WRITE | MAY_READ; |
1890 | cache.cred = cred; |
1891 | cache.jiffies = jiffies; |
1892 | status = NFS_PROTO(inode)->access(inode, &cache); |
1893 | if (status != 0) { |
1894 | if (status == -ESTALE) { |
1895 | nfs_zap_caches(inode); |
1896 | if (!S_ISDIR(inode->i_mode)) |
1897 | set_bit(NFS_INO_STALE, &NFS_I(inode)->flags); |
1898 | } |
1899 | return status; |
1900 | } |
1901 | nfs_access_add_cache(inode, &cache); |
1902 | out: |
1903 | if ((mask & ~cache.mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) |
1904 | return 0; |
1905 | return -EACCES; |
1906 | } |
1907 | |
1908 | static int nfs_open_permission_mask(int openflags) |
1909 | { |
1910 | int mask = 0; |
1911 | |
1912 | if (openflags & FMODE_READ) |
1913 | mask |= MAY_READ; |
1914 | if (openflags & FMODE_WRITE) |
1915 | mask |= MAY_WRITE; |
1916 | if (openflags & FMODE_EXEC) |
1917 | mask |= MAY_EXEC; |
1918 | return mask; |
1919 | } |
1920 | |
1921 | int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) |
1922 | { |
1923 | return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); |
1924 | } |
1925 | |
1926 | int nfs_permission(struct inode *inode, int mask) |
1927 | { |
1928 | struct rpc_cred *cred; |
1929 | int res = 0; |
1930 | |
1931 | nfs_inc_stats(inode, NFSIOS_VFSACCESS); |
1932 | |
1933 | if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) |
1934 | goto out; |
1935 | /* Is this sys_access() ? */ |
1936 | if (mask & MAY_ACCESS) |
1937 | goto force_lookup; |
1938 | |
1939 | switch (inode->i_mode & S_IFMT) { |
1940 | case S_IFLNK: |
1941 | goto out; |
1942 | case S_IFREG: |
1943 | /* NFSv4 has atomic_open... */ |
1944 | if (nfs_server_capable(inode, NFS_CAP_ATOMIC_OPEN) |
1945 | && (mask & MAY_OPEN) |
1946 | && !(mask & MAY_EXEC)) |
1947 | goto out; |
1948 | break; |
1949 | case S_IFDIR: |
1950 | /* |
1951 | * Optimize away all write operations, since the server |
1952 | * will check permissions when we perform the op. |
1953 | */ |
1954 | if ((mask & MAY_WRITE) && !(mask & MAY_READ)) |
1955 | goto out; |
1956 | } |
1957 | |
1958 | force_lookup: |
1959 | if (!NFS_PROTO(inode)->access) |
1960 | goto out_notsup; |
1961 | |
1962 | cred = rpc_lookup_cred(); |
1963 | if (!IS_ERR(cred)) { |
1964 | res = nfs_do_access(inode, cred, mask); |
1965 | put_rpccred(cred); |
1966 | } else |
1967 | res = PTR_ERR(cred); |
1968 | out: |
1969 | if (!res && (mask & MAY_EXEC) && !execute_ok(inode)) |
1970 | res = -EACCES; |
1971 | |
1972 | dfprintk(VFS, "NFS: permission(%s/%ld), mask=0x%x, res=%d\n", |
1973 | inode->i_sb->s_id, inode->i_ino, mask, res); |
1974 | return res; |
1975 | out_notsup: |
1976 | res = nfs_revalidate_inode(NFS_SERVER(inode), inode); |
1977 | if (res == 0) |
1978 | res = generic_permission(inode, mask, NULL); |
1979 | goto out; |
1980 | } |
1981 | |
1982 | /* |
1983 | * Local variables: |
1984 | * version-control: t |
1985 | * kept-new-versions: 5 |
1986 | * End: |
1987 | */ |
1988 |
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Tags:
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v2.6.34-rc5
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