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1da177e4 LT |
1 | /* |
2 | * linux/fs/reiserfs/xattr.c | |
3 | * | |
4 | * Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com> | |
5 | * | |
6 | */ | |
7 | ||
8 | /* | |
9 | * In order to implement EA/ACLs in a clean, backwards compatible manner, | |
10 | * they are implemented as files in a "private" directory. | |
11 | * Each EA is in it's own file, with the directory layout like so (/ is assumed | |
12 | * to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory, | |
13 | * directories named using the capital-hex form of the objectid and | |
14 | * generation number are used. Inside each directory are individual files | |
15 | * named with the name of the extended attribute. | |
16 | * | |
17 | * So, for objectid 12648430, we could have: | |
18 | * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access | |
19 | * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default | |
20 | * /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type | |
21 | * .. or similar. | |
22 | * | |
23 | * The file contents are the text of the EA. The size is known based on the | |
24 | * stat data describing the file. | |
25 | * | |
26 | * In the case of system.posix_acl_access and system.posix_acl_default, since | |
27 | * these are special cases for filesystem ACLs, they are interpreted by the | |
28 | * kernel, in addition, they are negatively and positively cached and attached | |
29 | * to the inode so that unnecessary lookups are avoided. | |
30 | */ | |
31 | ||
32 | #include <linux/reiserfs_fs.h> | |
33 | #include <linux/dcache.h> | |
34 | #include <linux/namei.h> | |
35 | #include <linux/errno.h> | |
36 | #include <linux/fs.h> | |
37 | #include <linux/file.h> | |
38 | #include <linux/pagemap.h> | |
39 | #include <linux/xattr.h> | |
40 | #include <linux/reiserfs_xattr.h> | |
41 | #include <linux/reiserfs_acl.h> | |
42 | #include <linux/mbcache.h> | |
43 | #include <asm/uaccess.h> | |
44 | #include <asm/checksum.h> | |
45 | #include <linux/smp_lock.h> | |
46 | #include <linux/stat.h> | |
47 | #include <asm/semaphore.h> | |
48 | ||
49 | #define FL_READONLY 128 | |
50 | #define FL_DIR_SEM_HELD 256 | |
51 | #define PRIVROOT_NAME ".reiserfs_priv" | |
52 | #define XAROOT_NAME "xattrs" | |
53 | ||
54 | static struct reiserfs_xattr_handler *find_xattr_handler_prefix (const char *prefix); | |
55 | ||
56 | static struct dentry * | |
57 | create_xa_root (struct super_block *sb) | |
58 | { | |
59 | struct dentry *privroot = dget (REISERFS_SB(sb)->priv_root); | |
60 | struct dentry *xaroot; | |
61 | ||
62 | /* This needs to be created at mount-time */ | |
63 | if (!privroot) | |
64 | return ERR_PTR(-EOPNOTSUPP); | |
65 | ||
66 | xaroot = lookup_one_len (XAROOT_NAME, privroot, strlen (XAROOT_NAME)); | |
67 | if (IS_ERR (xaroot)) { | |
68 | goto out; | |
69 | } else if (!xaroot->d_inode) { | |
70 | int err; | |
71 | down (&privroot->d_inode->i_sem); | |
72 | err = privroot->d_inode->i_op->mkdir (privroot->d_inode, xaroot, 0700); | |
73 | up (&privroot->d_inode->i_sem); | |
74 | ||
75 | if (err) { | |
76 | dput (xaroot); | |
77 | dput (privroot); | |
78 | return ERR_PTR (err); | |
79 | } | |
80 | REISERFS_SB(sb)->xattr_root = dget (xaroot); | |
81 | } | |
82 | ||
83 | out: | |
84 | dput (privroot); | |
85 | return xaroot; | |
86 | } | |
87 | ||
88 | /* This will return a dentry, or error, refering to the xa root directory. | |
89 | * If the xa root doesn't exist yet, the dentry will be returned without | |
90 | * an associated inode. This dentry can be used with ->mkdir to create | |
91 | * the xa directory. */ | |
92 | static struct dentry * | |
93 | __get_xa_root (struct super_block *s) | |
94 | { | |
95 | struct dentry *privroot = dget (REISERFS_SB(s)->priv_root); | |
96 | struct dentry *xaroot = NULL; | |
97 | ||
98 | if (IS_ERR (privroot) || !privroot) | |
99 | return privroot; | |
100 | ||
101 | xaroot = lookup_one_len (XAROOT_NAME, privroot, strlen (XAROOT_NAME)); | |
102 | if (IS_ERR (xaroot)) { | |
103 | goto out; | |
104 | } else if (!xaroot->d_inode) { | |
105 | dput (xaroot); | |
106 | xaroot = NULL; | |
107 | goto out; | |
108 | } | |
109 | ||
110 | REISERFS_SB(s)->xattr_root = dget (xaroot); | |
111 | ||
112 | out: | |
113 | dput (privroot); | |
114 | return xaroot; | |
115 | } | |
116 | ||
117 | /* Returns the dentry (or NULL) referring to the root of the extended | |
118 | * attribute directory tree. If it has already been retreived, it is used. | |
119 | * Otherwise, we attempt to retreive it from disk. It may also return | |
120 | * a pointer-encoded error. | |
121 | */ | |
122 | static inline struct dentry * | |
123 | get_xa_root (struct super_block *s) | |
124 | { | |
125 | struct dentry *dentry = dget (REISERFS_SB(s)->xattr_root); | |
126 | ||
127 | if (!dentry) | |
128 | dentry = __get_xa_root (s); | |
129 | ||
130 | return dentry; | |
131 | } | |
132 | ||
133 | /* Opens the directory corresponding to the inode's extended attribute store. | |
134 | * If flags allow, the tree to the directory may be created. If creation is | |
135 | * prohibited, -ENODATA is returned. */ | |
136 | static struct dentry * | |
137 | open_xa_dir (const struct inode *inode, int flags) | |
138 | { | |
139 | struct dentry *xaroot, *xadir; | |
140 | char namebuf[17]; | |
141 | ||
142 | xaroot = get_xa_root (inode->i_sb); | |
143 | if (IS_ERR (xaroot)) { | |
144 | return xaroot; | |
145 | } else if (!xaroot) { | |
146 | if (flags == 0 || flags & XATTR_CREATE) { | |
147 | xaroot = create_xa_root (inode->i_sb); | |
148 | if (IS_ERR (xaroot)) | |
149 | return xaroot; | |
150 | } | |
151 | if (!xaroot) | |
152 | return ERR_PTR (-ENODATA); | |
153 | } | |
154 | ||
155 | /* ok, we have xaroot open */ | |
156 | ||
157 | snprintf (namebuf, sizeof (namebuf), "%X.%X", | |
158 | le32_to_cpu (INODE_PKEY (inode)->k_objectid), | |
159 | inode->i_generation); | |
160 | xadir = lookup_one_len (namebuf, xaroot, strlen (namebuf)); | |
161 | if (IS_ERR (xadir)) { | |
162 | dput (xaroot); | |
163 | return xadir; | |
164 | } | |
165 | ||
166 | if (!xadir->d_inode) { | |
167 | int err; | |
168 | if (flags == 0 || flags & XATTR_CREATE) { | |
169 | /* Although there is nothing else trying to create this directory, | |
170 | * another directory with the same hash may be created, so we need | |
171 | * to protect against that */ | |
172 | err = xaroot->d_inode->i_op->mkdir (xaroot->d_inode, xadir, 0700); | |
173 | if (err) { | |
174 | dput (xaroot); | |
175 | dput (xadir); | |
176 | return ERR_PTR (err); | |
177 | } | |
178 | } | |
179 | if (!xadir->d_inode) { | |
180 | dput (xaroot); | |
181 | dput (xadir); | |
182 | return ERR_PTR (-ENODATA); | |
183 | } | |
184 | } | |
185 | ||
186 | dput (xaroot); | |
187 | return xadir; | |
188 | } | |
189 | ||
190 | /* Returns a dentry corresponding to a specific extended attribute file | |
191 | * for the inode. If flags allow, the file is created. Otherwise, a | |
192 | * valid or negative dentry, or an error is returned. */ | |
193 | static struct dentry * | |
194 | get_xa_file_dentry (const struct inode *inode, const char *name, int flags) | |
195 | { | |
196 | struct dentry *xadir, *xafile; | |
197 | int err = 0; | |
198 | ||
199 | xadir = open_xa_dir (inode, flags); | |
200 | if (IS_ERR (xadir)) { | |
201 | return ERR_PTR (PTR_ERR (xadir)); | |
202 | } else if (xadir && !xadir->d_inode) { | |
203 | dput (xadir); | |
204 | return ERR_PTR (-ENODATA); | |
205 | } | |
206 | ||
207 | xafile = lookup_one_len (name, xadir, strlen (name)); | |
208 | if (IS_ERR (xafile)) { | |
209 | dput (xadir); | |
210 | return ERR_PTR (PTR_ERR (xafile)); | |
211 | } | |
212 | ||
213 | if (xafile->d_inode) { /* file exists */ | |
214 | if (flags & XATTR_CREATE) { | |
215 | err = -EEXIST; | |
216 | dput (xafile); | |
217 | goto out; | |
218 | } | |
219 | } else if (flags & XATTR_REPLACE || flags & FL_READONLY) { | |
220 | goto out; | |
221 | } else { | |
222 | /* inode->i_sem is down, so nothing else can try to create | |
223 | * the same xattr */ | |
224 | err = xadir->d_inode->i_op->create (xadir->d_inode, xafile, | |
225 | 0700|S_IFREG, NULL); | |
226 | ||
227 | if (err) { | |
228 | dput (xafile); | |
229 | goto out; | |
230 | } | |
231 | } | |
232 | ||
233 | out: | |
234 | dput (xadir); | |
235 | if (err) | |
236 | xafile = ERR_PTR (err); | |
237 | return xafile; | |
238 | } | |
239 | ||
240 | ||
241 | /* Opens a file pointer to the attribute associated with inode */ | |
242 | static struct file * | |
243 | open_xa_file (const struct inode *inode, const char *name, int flags) | |
244 | { | |
245 | struct dentry *xafile; | |
246 | struct file *fp; | |
247 | ||
248 | xafile = get_xa_file_dentry (inode, name, flags); | |
249 | if (IS_ERR (xafile)) | |
250 | return ERR_PTR (PTR_ERR (xafile)); | |
251 | else if (!xafile->d_inode) { | |
252 | dput (xafile); | |
253 | return ERR_PTR (-ENODATA); | |
254 | } | |
255 | ||
256 | fp = dentry_open (xafile, NULL, O_RDWR); | |
257 | /* dentry_open dputs the dentry if it fails */ | |
258 | ||
259 | return fp; | |
260 | } | |
261 | ||
262 | ||
263 | /* | |
264 | * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but | |
265 | * we need to drop the path before calling the filldir struct. That | |
266 | * would be a big performance hit to the non-xattr case, so I've copied | |
267 | * the whole thing for now. --clm | |
268 | * | |
269 | * the big difference is that I go backwards through the directory, | |
270 | * and don't mess with f->f_pos, but the idea is the same. Do some | |
271 | * action on each and every entry in the directory. | |
272 | * | |
273 | * we're called with i_sem held, so there are no worries about the directory | |
274 | * changing underneath us. | |
275 | */ | |
276 | static int __xattr_readdir(struct file * filp, void * dirent, filldir_t filldir) | |
277 | { | |
278 | struct inode *inode = filp->f_dentry->d_inode; | |
279 | struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */ | |
280 | INITIALIZE_PATH (path_to_entry); | |
281 | struct buffer_head * bh; | |
282 | int entry_num; | |
283 | struct item_head * ih, tmp_ih; | |
284 | int search_res; | |
285 | char * local_buf; | |
286 | loff_t next_pos; | |
287 | char small_buf[32] ; /* avoid kmalloc if we can */ | |
288 | struct reiserfs_de_head *deh; | |
289 | int d_reclen; | |
290 | char * d_name; | |
291 | off_t d_off; | |
292 | ino_t d_ino; | |
293 | struct reiserfs_dir_entry de; | |
294 | ||
295 | ||
296 | /* form key for search the next directory entry using f_pos field of | |
297 | file structure */ | |
298 | next_pos = max_reiserfs_offset(inode); | |
299 | ||
300 | while (1) { | |
301 | research: | |
302 | if (next_pos <= DOT_DOT_OFFSET) | |
303 | break; | |
304 | make_cpu_key (&pos_key, inode, next_pos, TYPE_DIRENTRY, 3); | |
305 | ||
306 | search_res = search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, &de); | |
307 | if (search_res == IO_ERROR) { | |
308 | // FIXME: we could just skip part of directory which could | |
309 | // not be read | |
310 | pathrelse(&path_to_entry); | |
311 | return -EIO; | |
312 | } | |
313 | ||
314 | if (search_res == NAME_NOT_FOUND) | |
315 | de.de_entry_num--; | |
316 | ||
317 | set_de_name_and_namelen(&de); | |
318 | entry_num = de.de_entry_num; | |
319 | deh = &(de.de_deh[entry_num]); | |
320 | ||
321 | bh = de.de_bh; | |
322 | ih = de.de_ih; | |
323 | ||
324 | if (!is_direntry_le_ih(ih)) { | |
325 | reiserfs_warning(inode->i_sb, "not direntry %h", ih); | |
326 | break; | |
327 | } | |
328 | copy_item_head(&tmp_ih, ih); | |
329 | ||
330 | /* we must have found item, that is item of this directory, */ | |
331 | RFALSE( COMP_SHORT_KEYS (&(ih->ih_key), &pos_key), | |
332 | "vs-9000: found item %h does not match to dir we readdir %K", | |
333 | ih, &pos_key); | |
334 | ||
335 | if (deh_offset(deh) <= DOT_DOT_OFFSET) { | |
336 | break; | |
337 | } | |
338 | ||
339 | /* look for the previous entry in the directory */ | |
340 | next_pos = deh_offset (deh) - 1; | |
341 | ||
342 | if (!de_visible (deh)) | |
343 | /* it is hidden entry */ | |
344 | continue; | |
345 | ||
346 | d_reclen = entry_length(bh, ih, entry_num); | |
347 | d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh); | |
348 | d_off = deh_offset (deh); | |
349 | d_ino = deh_objectid (deh); | |
350 | ||
351 | if (!d_name[d_reclen - 1]) | |
352 | d_reclen = strlen (d_name); | |
353 | ||
354 | if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)){ | |
355 | /* too big to send back to VFS */ | |
356 | continue ; | |
357 | } | |
358 | ||
359 | /* Ignore the .reiserfs_priv entry */ | |
360 | if (reiserfs_xattrs (inode->i_sb) && | |
361 | !old_format_only(inode->i_sb) && | |
362 | deh_objectid (deh) == le32_to_cpu (INODE_PKEY(REISERFS_SB(inode->i_sb)->priv_root->d_inode)->k_objectid)) | |
363 | continue; | |
364 | ||
365 | if (d_reclen <= 32) { | |
366 | local_buf = small_buf ; | |
367 | } else { | |
368 | local_buf = reiserfs_kmalloc(d_reclen, GFP_NOFS, inode->i_sb) ; | |
369 | if (!local_buf) { | |
370 | pathrelse (&path_to_entry); | |
371 | return -ENOMEM ; | |
372 | } | |
373 | if (item_moved (&tmp_ih, &path_to_entry)) { | |
374 | reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ; | |
375 | ||
376 | /* sigh, must retry. Do this same offset again */ | |
377 | next_pos = d_off; | |
378 | goto research; | |
379 | } | |
380 | } | |
381 | ||
382 | // Note, that we copy name to user space via temporary | |
383 | // buffer (local_buf) because filldir will block if | |
384 | // user space buffer is swapped out. At that time | |
385 | // entry can move to somewhere else | |
386 | memcpy (local_buf, d_name, d_reclen); | |
387 | ||
388 | /* the filldir function might need to start transactions, | |
389 | * or do who knows what. Release the path now that we've | |
390 | * copied all the important stuff out of the deh | |
391 | */ | |
392 | pathrelse (&path_to_entry); | |
393 | ||
394 | if (filldir (dirent, local_buf, d_reclen, d_off, d_ino, | |
395 | DT_UNKNOWN) < 0) { | |
396 | if (local_buf != small_buf) { | |
397 | reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ; | |
398 | } | |
399 | goto end; | |
400 | } | |
401 | if (local_buf != small_buf) { | |
402 | reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ; | |
403 | } | |
404 | } /* while */ | |
405 | ||
406 | end: | |
407 | pathrelse (&path_to_entry); | |
408 | return 0; | |
409 | } | |
410 | ||
411 | /* | |
412 | * this could be done with dedicated readdir ops for the xattr files, | |
413 | * but I want to get something working asap | |
414 | * this is stolen from vfs_readdir | |
415 | * | |
416 | */ | |
417 | static | |
418 | int xattr_readdir(struct file *file, filldir_t filler, void *buf) | |
419 | { | |
420 | struct inode *inode = file->f_dentry->d_inode; | |
421 | int res = -ENOTDIR; | |
422 | if (!file->f_op || !file->f_op->readdir) | |
423 | goto out; | |
424 | down(&inode->i_sem); | |
425 | // down(&inode->i_zombie); | |
426 | res = -ENOENT; | |
427 | if (!IS_DEADDIR(inode)) { | |
428 | lock_kernel(); | |
429 | res = __xattr_readdir(file, buf, filler); | |
430 | unlock_kernel(); | |
431 | } | |
432 | // up(&inode->i_zombie); | |
433 | up(&inode->i_sem); | |
434 | out: | |
435 | return res; | |
436 | } | |
437 | ||
438 | ||
439 | /* Internal operations on file data */ | |
440 | static inline void | |
441 | reiserfs_put_page(struct page *page) | |
442 | { | |
443 | kunmap(page); | |
444 | page_cache_release(page); | |
445 | } | |
446 | ||
447 | static struct page * | |
448 | reiserfs_get_page(struct inode *dir, unsigned long n) | |
449 | { | |
450 | struct address_space *mapping = dir->i_mapping; | |
451 | struct page *page; | |
452 | /* We can deadlock if we try to free dentries, | |
453 | and an unlink/rmdir has just occured - GFP_NOFS avoids this */ | |
454 | mapping->flags = (mapping->flags & ~__GFP_BITS_MASK) | GFP_NOFS; | |
455 | page = read_cache_page (mapping, n, | |
456 | (filler_t*)mapping->a_ops->readpage, NULL); | |
457 | if (!IS_ERR(page)) { | |
458 | wait_on_page_locked(page); | |
459 | kmap(page); | |
460 | if (!PageUptodate(page)) | |
461 | goto fail; | |
462 | ||
463 | if (PageError(page)) | |
464 | goto fail; | |
465 | } | |
466 | return page; | |
467 | ||
468 | fail: | |
469 | reiserfs_put_page(page); | |
470 | return ERR_PTR(-EIO); | |
471 | } | |
472 | ||
473 | static inline __u32 | |
474 | xattr_hash (const char *msg, int len) | |
475 | { | |
476 | return csum_partial (msg, len, 0); | |
477 | } | |
478 | ||
479 | /* Generic extended attribute operations that can be used by xa plugins */ | |
480 | ||
481 | /* | |
482 | * inode->i_sem: down | |
483 | */ | |
484 | int | |
485 | reiserfs_xattr_set (struct inode *inode, const char *name, const void *buffer, | |
486 | size_t buffer_size, int flags) | |
487 | { | |
488 | int err = 0; | |
489 | struct file *fp; | |
490 | struct page *page; | |
491 | char *data; | |
492 | struct address_space *mapping; | |
493 | size_t file_pos = 0; | |
494 | size_t buffer_pos = 0; | |
495 | struct inode *xinode; | |
496 | struct iattr newattrs; | |
497 | __u32 xahash = 0; | |
498 | ||
499 | if (IS_RDONLY (inode)) | |
500 | return -EROFS; | |
501 | ||
502 | if (IS_IMMUTABLE (inode) || IS_APPEND (inode)) | |
503 | return -EPERM; | |
504 | ||
505 | if (get_inode_sd_version (inode) == STAT_DATA_V1) | |
506 | return -EOPNOTSUPP; | |
507 | ||
508 | /* Empty xattrs are ok, they're just empty files, no hash */ | |
509 | if (buffer && buffer_size) | |
510 | xahash = xattr_hash (buffer, buffer_size); | |
511 | ||
512 | open_file: | |
513 | fp = open_xa_file (inode, name, flags); | |
514 | if (IS_ERR (fp)) { | |
515 | err = PTR_ERR (fp); | |
516 | goto out; | |
517 | } | |
518 | ||
519 | xinode = fp->f_dentry->d_inode; | |
520 | REISERFS_I(inode)->i_flags |= i_has_xattr_dir; | |
521 | ||
522 | /* we need to copy it off.. */ | |
523 | if (xinode->i_nlink > 1) { | |
524 | fput(fp); | |
525 | err = reiserfs_xattr_del (inode, name); | |
526 | if (err < 0) | |
527 | goto out; | |
528 | /* We just killed the old one, we're not replacing anymore */ | |
529 | if (flags & XATTR_REPLACE) | |
530 | flags &= ~XATTR_REPLACE; | |
531 | goto open_file; | |
532 | } | |
533 | ||
534 | /* Resize it so we're ok to write there */ | |
535 | newattrs.ia_size = buffer_size; | |
536 | newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME; | |
537 | down (&xinode->i_sem); | |
538 | err = notify_change(fp->f_dentry, &newattrs); | |
539 | if (err) | |
540 | goto out_filp; | |
541 | ||
542 | mapping = xinode->i_mapping; | |
543 | while (buffer_pos < buffer_size || buffer_pos == 0) { | |
544 | size_t chunk; | |
545 | size_t skip = 0; | |
546 | size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1)); | |
547 | if (buffer_size - buffer_pos > PAGE_CACHE_SIZE) | |
548 | chunk = PAGE_CACHE_SIZE; | |
549 | else | |
550 | chunk = buffer_size - buffer_pos; | |
551 | ||
552 | page = reiserfs_get_page (xinode, file_pos >> PAGE_CACHE_SHIFT); | |
553 | if (IS_ERR (page)) { | |
554 | err = PTR_ERR (page); | |
555 | goto out_filp; | |
556 | } | |
557 | ||
558 | lock_page (page); | |
559 | data = page_address (page); | |
560 | ||
561 | if (file_pos == 0) { | |
562 | struct reiserfs_xattr_header *rxh; | |
563 | skip = file_pos = sizeof (struct reiserfs_xattr_header); | |
564 | if (chunk + skip > PAGE_CACHE_SIZE) | |
565 | chunk = PAGE_CACHE_SIZE - skip; | |
566 | rxh = (struct reiserfs_xattr_header *)data; | |
567 | rxh->h_magic = cpu_to_le32 (REISERFS_XATTR_MAGIC); | |
568 | rxh->h_hash = cpu_to_le32 (xahash); | |
569 | } | |
570 | ||
571 | err = mapping->a_ops->prepare_write (fp, page, page_offset, | |
572 | page_offset + chunk + skip); | |
573 | if (!err) { | |
574 | if (buffer) | |
575 | memcpy (data + skip, buffer + buffer_pos, chunk); | |
576 | err = mapping->a_ops->commit_write (fp, page, page_offset, | |
577 | page_offset + chunk + skip); | |
578 | } | |
579 | unlock_page (page); | |
580 | reiserfs_put_page (page); | |
581 | buffer_pos += chunk; | |
582 | file_pos += chunk; | |
583 | skip = 0; | |
584 | if (err || buffer_size == 0 || !buffer) | |
585 | break; | |
586 | } | |
587 | ||
588 | /* We can't mark the inode dirty if it's not hashed. This is the case | |
589 | * when we're inheriting the default ACL. If we dirty it, the inode | |
590 | * gets marked dirty, but won't (ever) make it onto the dirty list until | |
591 | * it's synced explicitly to clear I_DIRTY. This is bad. */ | |
592 | if (!hlist_unhashed(&inode->i_hash)) { | |
593 | inode->i_ctime = CURRENT_TIME_SEC; | |
594 | mark_inode_dirty (inode); | |
595 | } | |
596 | ||
597 | out_filp: | |
598 | up (&xinode->i_sem); | |
599 | fput(fp); | |
600 | ||
601 | out: | |
602 | return err; | |
603 | } | |
604 | ||
605 | /* | |
606 | * inode->i_sem: down | |
607 | */ | |
608 | int | |
609 | reiserfs_xattr_get (const struct inode *inode, const char *name, void *buffer, | |
610 | size_t buffer_size) | |
611 | { | |
612 | ssize_t err = 0; | |
613 | struct file *fp; | |
614 | size_t isize; | |
615 | size_t file_pos = 0; | |
616 | size_t buffer_pos = 0; | |
617 | struct page *page; | |
618 | struct inode *xinode; | |
619 | __u32 hash = 0; | |
620 | ||
621 | if (name == NULL) | |
622 | return -EINVAL; | |
623 | ||
624 | /* We can't have xattrs attached to v1 items since they don't have | |
625 | * generation numbers */ | |
626 | if (get_inode_sd_version (inode) == STAT_DATA_V1) | |
627 | return -EOPNOTSUPP; | |
628 | ||
629 | fp = open_xa_file (inode, name, FL_READONLY); | |
630 | if (IS_ERR (fp)) { | |
631 | err = PTR_ERR (fp); | |
632 | goto out; | |
633 | } | |
634 | ||
635 | xinode = fp->f_dentry->d_inode; | |
636 | isize = xinode->i_size; | |
637 | REISERFS_I(inode)->i_flags |= i_has_xattr_dir; | |
638 | ||
639 | /* Just return the size needed */ | |
640 | if (buffer == NULL) { | |
641 | err = isize - sizeof (struct reiserfs_xattr_header); | |
642 | goto out_dput; | |
643 | } | |
644 | ||
645 | if (buffer_size < isize - sizeof (struct reiserfs_xattr_header)) { | |
646 | err = -ERANGE; | |
647 | goto out_dput; | |
648 | } | |
649 | ||
650 | while (file_pos < isize) { | |
651 | size_t chunk; | |
652 | char *data; | |
653 | size_t skip = 0; | |
654 | if (isize - file_pos > PAGE_CACHE_SIZE) | |
655 | chunk = PAGE_CACHE_SIZE; | |
656 | else | |
657 | chunk = isize - file_pos; | |
658 | ||
659 | page = reiserfs_get_page (xinode, file_pos >> PAGE_CACHE_SHIFT); | |
660 | if (IS_ERR (page)) { | |
661 | err = PTR_ERR (page); | |
662 | goto out_dput; | |
663 | } | |
664 | ||
665 | lock_page (page); | |
666 | data = page_address (page); | |
667 | if (file_pos == 0) { | |
668 | struct reiserfs_xattr_header *rxh = | |
669 | (struct reiserfs_xattr_header *)data; | |
670 | skip = file_pos = sizeof (struct reiserfs_xattr_header); | |
671 | chunk -= skip; | |
672 | /* Magic doesn't match up.. */ | |
673 | if (rxh->h_magic != cpu_to_le32 (REISERFS_XATTR_MAGIC)) { | |
674 | unlock_page (page); | |
675 | reiserfs_put_page (page); | |
676 | reiserfs_warning (inode->i_sb, "Invalid magic for xattr (%s) " | |
677 | "associated with %k", name, | |
678 | INODE_PKEY (inode)); | |
679 | err = -EIO; | |
680 | goto out_dput; | |
681 | } | |
682 | hash = le32_to_cpu (rxh->h_hash); | |
683 | } | |
684 | memcpy (buffer + buffer_pos, data + skip, chunk); | |
685 | unlock_page (page); | |
686 | reiserfs_put_page (page); | |
687 | file_pos += chunk; | |
688 | buffer_pos += chunk; | |
689 | skip = 0; | |
690 | } | |
691 | err = isize - sizeof (struct reiserfs_xattr_header); | |
692 | ||
693 | if (xattr_hash (buffer, isize - sizeof (struct reiserfs_xattr_header)) != hash) { | |
694 | reiserfs_warning (inode->i_sb, "Invalid hash for xattr (%s) associated " | |
695 | "with %k", name, INODE_PKEY (inode)); | |
696 | err = -EIO; | |
697 | } | |
698 | ||
699 | out_dput: | |
700 | fput(fp); | |
701 | ||
702 | out: | |
703 | return err; | |
704 | } | |
705 | ||
706 | static int | |
707 | __reiserfs_xattr_del (struct dentry *xadir, const char *name, int namelen) | |
708 | { | |
709 | struct dentry *dentry; | |
710 | struct inode *dir = xadir->d_inode; | |
711 | int err = 0; | |
712 | ||
713 | dentry = lookup_one_len (name, xadir, namelen); | |
714 | if (IS_ERR (dentry)) { | |
715 | err = PTR_ERR (dentry); | |
716 | goto out; | |
717 | } else if (!dentry->d_inode) { | |
718 | err = -ENODATA; | |
719 | goto out_file; | |
720 | } | |
721 | ||
722 | /* Skip directories.. */ | |
723 | if (S_ISDIR (dentry->d_inode->i_mode)) | |
724 | goto out_file; | |
725 | ||
726 | if (!is_reiserfs_priv_object (dentry->d_inode)) { | |
727 | reiserfs_warning (dir->i_sb, "OID %08x [%.*s/%.*s] doesn't have " | |
728 | "priv flag set [parent is %sset].", | |
729 | le32_to_cpu (INODE_PKEY (dentry->d_inode)->k_objectid), | |
730 | xadir->d_name.len, xadir->d_name.name, namelen, name, | |
731 | is_reiserfs_priv_object (xadir->d_inode) ? "" : "not "); | |
732 | dput (dentry); | |
733 | return -EIO; | |
734 | } | |
735 | ||
736 | err = dir->i_op->unlink (dir, dentry); | |
737 | if (!err) | |
738 | d_delete (dentry); | |
739 | ||
740 | out_file: | |
741 | dput (dentry); | |
742 | ||
743 | out: | |
744 | return err; | |
745 | } | |
746 | ||
747 | ||
748 | int | |
749 | reiserfs_xattr_del (struct inode *inode, const char *name) | |
750 | { | |
751 | struct dentry *dir; | |
752 | int err; | |
753 | ||
754 | if (IS_RDONLY (inode)) | |
755 | return -EROFS; | |
756 | ||
757 | dir = open_xa_dir (inode, FL_READONLY); | |
758 | if (IS_ERR (dir)) { | |
759 | err = PTR_ERR (dir); | |
760 | goto out; | |
761 | } | |
762 | ||
763 | err = __reiserfs_xattr_del (dir, name, strlen (name)); | |
764 | dput (dir); | |
765 | ||
766 | if (!err) { | |
767 | inode->i_ctime = CURRENT_TIME_SEC; | |
768 | mark_inode_dirty (inode); | |
769 | } | |
770 | ||
771 | out: | |
772 | return err; | |
773 | } | |
774 | ||
775 | /* The following are side effects of other operations that aren't explicitly | |
776 | * modifying extended attributes. This includes operations such as permissions | |
777 | * or ownership changes, object deletions, etc. */ | |
778 | ||
779 | static int | |
780 | reiserfs_delete_xattrs_filler (void *buf, const char *name, int namelen, | |
781 | loff_t offset, ino_t ino, unsigned int d_type) | |
782 | { | |
783 | struct dentry *xadir = (struct dentry *)buf; | |
784 | ||
785 | return __reiserfs_xattr_del (xadir, name, namelen); | |
786 | ||
787 | } | |
788 | ||
789 | /* This is called w/ inode->i_sem downed */ | |
790 | int | |
791 | reiserfs_delete_xattrs (struct inode *inode) | |
792 | { | |
793 | struct file *fp; | |
794 | struct dentry *dir, *root; | |
795 | int err = 0; | |
796 | ||
797 | /* Skip out, an xattr has no xattrs associated with it */ | |
798 | if (is_reiserfs_priv_object (inode) || | |
799 | get_inode_sd_version (inode) == STAT_DATA_V1 || | |
800 | !reiserfs_xattrs(inode->i_sb)) | |
801 | { | |
802 | return 0; | |
803 | } | |
804 | reiserfs_read_lock_xattrs (inode->i_sb); | |
805 | dir = open_xa_dir (inode, FL_READONLY); | |
806 | reiserfs_read_unlock_xattrs (inode->i_sb); | |
807 | if (IS_ERR (dir)) { | |
808 | err = PTR_ERR (dir); | |
809 | goto out; | |
810 | } else if (!dir->d_inode) { | |
811 | dput (dir); | |
812 | return 0; | |
813 | } | |
814 | ||
815 | fp = dentry_open (dir, NULL, O_RDWR); | |
816 | if (IS_ERR (fp)) { | |
817 | err = PTR_ERR (fp); | |
818 | /* dentry_open dputs the dentry if it fails */ | |
819 | goto out; | |
820 | } | |
821 | ||
822 | lock_kernel (); | |
823 | err = xattr_readdir (fp, reiserfs_delete_xattrs_filler, dir); | |
824 | if (err) { | |
825 | unlock_kernel (); | |
826 | goto out_dir; | |
827 | } | |
828 | ||
829 | /* Leftovers besides . and .. -- that's not good. */ | |
830 | if (dir->d_inode->i_nlink <= 2) { | |
831 | root = get_xa_root (inode->i_sb); | |
832 | reiserfs_write_lock_xattrs (inode->i_sb); | |
833 | err = vfs_rmdir (root->d_inode, dir); | |
834 | reiserfs_write_unlock_xattrs (inode->i_sb); | |
835 | dput (root); | |
836 | } else { | |
837 | reiserfs_warning (inode->i_sb, | |
838 | "Couldn't remove all entries in directory"); | |
839 | } | |
840 | unlock_kernel (); | |
841 | ||
842 | out_dir: | |
843 | fput(fp); | |
844 | ||
845 | out: | |
846 | if (!err) | |
847 | REISERFS_I(inode)->i_flags = REISERFS_I(inode)->i_flags & ~i_has_xattr_dir; | |
848 | return err; | |
849 | } | |
850 | ||
851 | struct reiserfs_chown_buf { | |
852 | struct inode *inode; | |
853 | struct dentry *xadir; | |
854 | struct iattr *attrs; | |
855 | }; | |
856 | ||
857 | /* XXX: If there is a better way to do this, I'd love to hear about it */ | |
858 | static int | |
859 | reiserfs_chown_xattrs_filler (void *buf, const char *name, int namelen, | |
860 | loff_t offset, ino_t ino, unsigned int d_type) | |
861 | { | |
862 | struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf; | |
863 | struct dentry *xafile, *xadir = chown_buf->xadir; | |
864 | struct iattr *attrs = chown_buf->attrs; | |
865 | int err = 0; | |
866 | ||
867 | xafile = lookup_one_len (name, xadir, namelen); | |
868 | if (IS_ERR (xafile)) | |
869 | return PTR_ERR (xafile); | |
870 | else if (!xafile->d_inode) { | |
871 | dput (xafile); | |
872 | return -ENODATA; | |
873 | } | |
874 | ||
875 | if (!S_ISDIR (xafile->d_inode->i_mode)) | |
876 | err = notify_change (xafile, attrs); | |
877 | dput (xafile); | |
878 | ||
879 | return err; | |
880 | } | |
881 | ||
882 | int | |
883 | reiserfs_chown_xattrs (struct inode *inode, struct iattr *attrs) | |
884 | { | |
885 | struct file *fp; | |
886 | struct dentry *dir; | |
887 | int err = 0; | |
888 | struct reiserfs_chown_buf buf; | |
889 | unsigned int ia_valid = attrs->ia_valid; | |
890 | ||
891 | /* Skip out, an xattr has no xattrs associated with it */ | |
892 | if (is_reiserfs_priv_object (inode) || | |
893 | get_inode_sd_version (inode) == STAT_DATA_V1 || | |
894 | !reiserfs_xattrs(inode->i_sb)) | |
895 | { | |
896 | return 0; | |
897 | } | |
898 | reiserfs_read_lock_xattrs (inode->i_sb); | |
899 | dir = open_xa_dir (inode, FL_READONLY); | |
900 | reiserfs_read_unlock_xattrs (inode->i_sb); | |
901 | if (IS_ERR (dir)) { | |
902 | if (PTR_ERR (dir) != -ENODATA) | |
903 | err = PTR_ERR (dir); | |
904 | goto out; | |
905 | } else if (!dir->d_inode) { | |
906 | dput (dir); | |
907 | goto out; | |
908 | } | |
909 | ||
910 | fp = dentry_open (dir, NULL, O_RDWR); | |
911 | if (IS_ERR (fp)) { | |
912 | err = PTR_ERR (fp); | |
913 | /* dentry_open dputs the dentry if it fails */ | |
914 | goto out; | |
915 | } | |
916 | ||
917 | lock_kernel (); | |
918 | ||
919 | attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME); | |
920 | buf.xadir = dir; | |
921 | buf.attrs = attrs; | |
922 | buf.inode = inode; | |
923 | ||
924 | err = xattr_readdir (fp, reiserfs_chown_xattrs_filler, &buf); | |
925 | if (err) { | |
926 | unlock_kernel (); | |
927 | goto out_dir; | |
928 | } | |
929 | ||
930 | err = notify_change (dir, attrs); | |
931 | unlock_kernel (); | |
932 | ||
933 | out_dir: | |
934 | fput(fp); | |
935 | ||
936 | out: | |
937 | attrs->ia_valid = ia_valid; | |
938 | return err; | |
939 | } | |
940 | ||
941 | ||
942 | /* Actual operations that are exported to VFS-land */ | |
943 | ||
944 | /* | |
945 | * Inode operation getxattr() | |
946 | * Preliminary locking: we down dentry->d_inode->i_sem | |
947 | */ | |
948 | ssize_t | |
949 | reiserfs_getxattr (struct dentry *dentry, const char *name, void *buffer, | |
950 | size_t size) | |
951 | { | |
952 | struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name); | |
953 | int err; | |
954 | ||
955 | if (!xah || !reiserfs_xattrs(dentry->d_sb) || | |
956 | get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1) | |
957 | return -EOPNOTSUPP; | |
958 | ||
959 | reiserfs_read_lock_xattr_i (dentry->d_inode); | |
960 | reiserfs_read_lock_xattrs (dentry->d_sb); | |
961 | err = xah->get (dentry->d_inode, name, buffer, size); | |
962 | reiserfs_read_unlock_xattrs (dentry->d_sb); | |
963 | reiserfs_read_unlock_xattr_i (dentry->d_inode); | |
964 | return err; | |
965 | } | |
966 | ||
967 | ||
968 | /* | |
969 | * Inode operation setxattr() | |
970 | * | |
971 | * dentry->d_inode->i_sem down | |
972 | */ | |
973 | int | |
974 | reiserfs_setxattr (struct dentry *dentry, const char *name, const void *value, | |
975 | size_t size, int flags) | |
976 | { | |
977 | struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name); | |
978 | int err; | |
979 | int lock; | |
980 | ||
981 | if (!xah || !reiserfs_xattrs(dentry->d_sb) || | |
982 | get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1) | |
983 | return -EOPNOTSUPP; | |
984 | ||
985 | if (IS_RDONLY (dentry->d_inode)) | |
986 | return -EROFS; | |
987 | ||
988 | if (IS_IMMUTABLE (dentry->d_inode) || IS_APPEND (dentry->d_inode)) | |
989 | return -EROFS; | |
990 | ||
991 | reiserfs_write_lock_xattr_i (dentry->d_inode); | |
992 | lock = !has_xattr_dir (dentry->d_inode); | |
993 | if (lock) | |
994 | reiserfs_write_lock_xattrs (dentry->d_sb); | |
995 | else | |
996 | reiserfs_read_lock_xattrs (dentry->d_sb); | |
997 | err = xah->set (dentry->d_inode, name, value, size, flags); | |
998 | if (lock) | |
999 | reiserfs_write_unlock_xattrs (dentry->d_sb); | |
1000 | else | |
1001 | reiserfs_read_unlock_xattrs (dentry->d_sb); | |
1002 | reiserfs_write_unlock_xattr_i (dentry->d_inode); | |
1003 | return err; | |
1004 | } | |
1005 | ||
1006 | /* | |
1007 | * Inode operation removexattr() | |
1008 | * | |
1009 | * dentry->d_inode->i_sem down | |
1010 | */ | |
1011 | int | |
1012 | reiserfs_removexattr (struct dentry *dentry, const char *name) | |
1013 | { | |
1014 | int err; | |
1015 | struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name); | |
1016 | ||
1017 | if (!xah || !reiserfs_xattrs(dentry->d_sb) || | |
1018 | get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1) | |
1019 | return -EOPNOTSUPP; | |
1020 | ||
1021 | if (IS_RDONLY (dentry->d_inode)) | |
1022 | return -EROFS; | |
1023 | ||
1024 | if (IS_IMMUTABLE (dentry->d_inode) || IS_APPEND (dentry->d_inode)) | |
1025 | return -EPERM; | |
1026 | ||
1027 | reiserfs_write_lock_xattr_i (dentry->d_inode); | |
1028 | reiserfs_read_lock_xattrs (dentry->d_sb); | |
1029 | ||
1030 | /* Deletion pre-operation */ | |
1031 | if (xah->del) { | |
1032 | err = xah->del (dentry->d_inode, name); | |
1033 | if (err) | |
1034 | goto out; | |
1035 | } | |
1036 | ||
1037 | err = reiserfs_xattr_del (dentry->d_inode, name); | |
1038 | ||
1039 | dentry->d_inode->i_ctime = CURRENT_TIME_SEC; | |
1040 | mark_inode_dirty (dentry->d_inode); | |
1041 | ||
1042 | out: | |
1043 | reiserfs_read_unlock_xattrs (dentry->d_sb); | |
1044 | reiserfs_write_unlock_xattr_i (dentry->d_inode); | |
1045 | return err; | |
1046 | } | |
1047 | ||
1048 | ||
1049 | /* This is what filldir will use: | |
1050 | * r_pos will always contain the amount of space required for the entire | |
1051 | * list. If r_pos becomes larger than r_size, we need more space and we | |
1052 | * return an error indicating this. If r_pos is less than r_size, then we've | |
1053 | * filled the buffer successfully and we return success */ | |
1054 | struct reiserfs_listxattr_buf { | |
1055 | int r_pos; | |
1056 | int r_size; | |
1057 | char *r_buf; | |
1058 | struct inode *r_inode; | |
1059 | }; | |
1060 | ||
1061 | static int | |
1062 | reiserfs_listxattr_filler (void *buf, const char *name, int namelen, | |
1063 | loff_t offset, ino_t ino, unsigned int d_type) | |
1064 | { | |
1065 | struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf; | |
1066 | int len = 0; | |
1067 | if (name[0] != '.' || (namelen != 1 && (name[1] != '.' || namelen != 2))) { | |
1068 | struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name); | |
1069 | if (!xah) return 0; /* Unsupported xattr name, skip it */ | |
1070 | ||
1071 | /* We call ->list() twice because the operation isn't required to just | |
1072 | * return the name back - we want to make sure we have enough space */ | |
1073 | len += xah->list (b->r_inode, name, namelen, NULL); | |
1074 | ||
1075 | if (len) { | |
1076 | if (b->r_pos + len + 1 <= b->r_size) { | |
1077 | char *p = b->r_buf + b->r_pos; | |
1078 | p += xah->list (b->r_inode, name, namelen, p); | |
1079 | *p++ = '\0'; | |
1080 | } | |
1081 | b->r_pos += len + 1; | |
1082 | } | |
1083 | } | |
1084 | ||
1085 | return 0; | |
1086 | } | |
1087 | /* | |
1088 | * Inode operation listxattr() | |
1089 | * | |
1090 | * Preliminary locking: we down dentry->d_inode->i_sem | |
1091 | */ | |
1092 | ssize_t | |
1093 | reiserfs_listxattr (struct dentry *dentry, char *buffer, size_t size) | |
1094 | { | |
1095 | struct file *fp; | |
1096 | struct dentry *dir; | |
1097 | int err = 0; | |
1098 | struct reiserfs_listxattr_buf buf; | |
1099 | ||
1100 | if (!dentry->d_inode) | |
1101 | return -EINVAL; | |
1102 | ||
1103 | if (!reiserfs_xattrs(dentry->d_sb) || | |
1104 | get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1) | |
1105 | return -EOPNOTSUPP; | |
1106 | ||
1107 | reiserfs_read_lock_xattr_i (dentry->d_inode); | |
1108 | reiserfs_read_lock_xattrs (dentry->d_sb); | |
1109 | dir = open_xa_dir (dentry->d_inode, FL_READONLY); | |
1110 | reiserfs_read_unlock_xattrs (dentry->d_sb); | |
1111 | if (IS_ERR (dir)) { | |
1112 | err = PTR_ERR (dir); | |
1113 | if (err == -ENODATA) | |
1114 | err = 0; /* Not an error if there aren't any xattrs */ | |
1115 | goto out; | |
1116 | } | |
1117 | ||
1118 | fp = dentry_open (dir, NULL, O_RDWR); | |
1119 | if (IS_ERR (fp)) { | |
1120 | err = PTR_ERR (fp); | |
1121 | /* dentry_open dputs the dentry if it fails */ | |
1122 | goto out; | |
1123 | } | |
1124 | ||
1125 | buf.r_buf = buffer; | |
1126 | buf.r_size = buffer ? size : 0; | |
1127 | buf.r_pos = 0; | |
1128 | buf.r_inode = dentry->d_inode; | |
1129 | ||
1130 | REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir; | |
1131 | ||
1132 | err = xattr_readdir (fp, reiserfs_listxattr_filler, &buf); | |
1133 | if (err) | |
1134 | goto out_dir; | |
1135 | ||
1136 | if (buf.r_pos > buf.r_size && buffer != NULL) | |
1137 | err = -ERANGE; | |
1138 | else | |
1139 | err = buf.r_pos; | |
1140 | ||
1141 | out_dir: | |
1142 | fput(fp); | |
1143 | ||
1144 | out: | |
1145 | reiserfs_read_unlock_xattr_i (dentry->d_inode); | |
1146 | return err; | |
1147 | } | |
1148 | ||
1149 | /* This is the implementation for the xattr plugin infrastructure */ | |
1150 | static struct list_head xattr_handlers = LIST_HEAD_INIT (xattr_handlers); | |
1151 | static DEFINE_RWLOCK(handler_lock); | |
1152 | ||
1153 | static struct reiserfs_xattr_handler * | |
1154 | find_xattr_handler_prefix (const char *prefix) | |
1155 | { | |
1156 | struct reiserfs_xattr_handler *xah = NULL; | |
1157 | struct list_head *p; | |
1158 | ||
1159 | read_lock (&handler_lock); | |
1160 | list_for_each (p, &xattr_handlers) { | |
1161 | xah = list_entry (p, struct reiserfs_xattr_handler, handlers); | |
1162 | if (strncmp (xah->prefix, prefix, strlen (xah->prefix)) == 0) | |
1163 | break; | |
1164 | xah = NULL; | |
1165 | } | |
1166 | ||
1167 | read_unlock (&handler_lock); | |
1168 | return xah; | |
1169 | } | |
1170 | ||
1171 | static void | |
1172 | __unregister_handlers (void) | |
1173 | { | |
1174 | struct reiserfs_xattr_handler *xah; | |
1175 | struct list_head *p, *tmp; | |
1176 | ||
1177 | list_for_each_safe (p, tmp, &xattr_handlers) { | |
1178 | xah = list_entry (p, struct reiserfs_xattr_handler, handlers); | |
1179 | if (xah->exit) | |
1180 | xah->exit(); | |
1181 | ||
1182 | list_del_init (p); | |
1183 | } | |
1184 | INIT_LIST_HEAD (&xattr_handlers); | |
1185 | } | |
1186 | ||
1187 | int __init | |
1188 | reiserfs_xattr_register_handlers (void) | |
1189 | { | |
1190 | int err = 0; | |
1191 | struct reiserfs_xattr_handler *xah; | |
1192 | struct list_head *p; | |
1193 | ||
1194 | write_lock (&handler_lock); | |
1195 | ||
1196 | /* If we're already initialized, nothing to do */ | |
1197 | if (!list_empty (&xattr_handlers)) { | |
1198 | write_unlock (&handler_lock); | |
1199 | return 0; | |
1200 | } | |
1201 | ||
1202 | /* Add the handlers */ | |
1203 | list_add_tail (&user_handler.handlers, &xattr_handlers); | |
1204 | list_add_tail (&trusted_handler.handlers, &xattr_handlers); | |
1205 | #ifdef CONFIG_REISERFS_FS_SECURITY | |
1206 | list_add_tail (&security_handler.handlers, &xattr_handlers); | |
1207 | #endif | |
1208 | #ifdef CONFIG_REISERFS_FS_POSIX_ACL | |
1209 | list_add_tail (&posix_acl_access_handler.handlers, &xattr_handlers); | |
1210 | list_add_tail (&posix_acl_default_handler.handlers, &xattr_handlers); | |
1211 | #endif | |
1212 | ||
1213 | /* Run initializers, if available */ | |
1214 | list_for_each (p, &xattr_handlers) { | |
1215 | xah = list_entry (p, struct reiserfs_xattr_handler, handlers); | |
1216 | if (xah->init) { | |
1217 | err = xah->init (); | |
1218 | if (err) { | |
1219 | list_del_init (p); | |
1220 | break; | |
1221 | } | |
1222 | } | |
1223 | } | |
1224 | ||
1225 | /* Clean up other handlers, if any failed */ | |
1226 | if (err) | |
1227 | __unregister_handlers (); | |
1228 | ||
1229 | write_unlock (&handler_lock); | |
1230 | return err; | |
1231 | } | |
1232 | ||
1233 | void | |
1234 | reiserfs_xattr_unregister_handlers (void) | |
1235 | { | |
1236 | write_lock (&handler_lock); | |
1237 | __unregister_handlers (); | |
1238 | write_unlock (&handler_lock); | |
1239 | } | |
1240 | ||
1241 | /* This will catch lookups from the fs root to .reiserfs_priv */ | |
1242 | static int | |
1243 | xattr_lookup_poison (struct dentry *dentry, struct qstr *q1, struct qstr *name) | |
1244 | { | |
1245 | struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root; | |
1246 | if (name->len == priv_root->d_name.len && | |
1247 | name->hash == priv_root->d_name.hash && | |
1248 | !memcmp (name->name, priv_root->d_name.name, name->len)) { | |
1249 | return -ENOENT; | |
1250 | } else if (q1->len == name->len && | |
1251 | !memcmp(q1->name, name->name, name->len)) | |
1252 | return 0; | |
1253 | return 1; | |
1254 | } | |
1255 | ||
1256 | static struct dentry_operations xattr_lookup_poison_ops = { | |
1257 | .d_compare = xattr_lookup_poison, | |
1258 | }; | |
1259 | ||
1260 | ||
1261 | /* We need to take a copy of the mount flags since things like | |
1262 | * MS_RDONLY don't get set until *after* we're called. | |
1263 | * mount_flags != mount_options */ | |
1264 | int | |
1265 | reiserfs_xattr_init (struct super_block *s, int mount_flags) | |
1266 | { | |
1267 | int err = 0; | |
1268 | ||
1269 | /* We need generation numbers to ensure that the oid mapping is correct | |
1270 | * v3.5 filesystems don't have them. */ | |
1271 | if (!old_format_only (s)) { | |
1272 | set_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt)); | |
1273 | } else if (reiserfs_xattrs_optional (s)) { | |
1274 | /* Old format filesystem, but optional xattrs have been enabled | |
1275 | * at mount time. Error out. */ | |
1276 | reiserfs_warning (s, "xattrs/ACLs not supported on pre v3.6 " | |
1277 | "format filesystem. Failing mount."); | |
1278 | err = -EOPNOTSUPP; | |
1279 | goto error; | |
1280 | } else { | |
1281 | /* Old format filesystem, but no optional xattrs have been enabled. This | |
1282 | * means we silently disable xattrs on the filesystem. */ | |
1283 | clear_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt)); | |
1284 | } | |
1285 | ||
1286 | /* If we don't have the privroot located yet - go find it */ | |
1287 | if (reiserfs_xattrs (s) && !REISERFS_SB(s)->priv_root) { | |
1288 | struct dentry *dentry; | |
1289 | dentry = lookup_one_len (PRIVROOT_NAME, s->s_root, | |
1290 | strlen (PRIVROOT_NAME)); | |
1291 | if (!IS_ERR (dentry)) { | |
1292 | if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) { | |
1293 | struct inode *inode = dentry->d_parent->d_inode; | |
1294 | down (&inode->i_sem); | |
1295 | err = inode->i_op->mkdir (inode, dentry, 0700); | |
1296 | up (&inode->i_sem); | |
1297 | if (err) { | |
1298 | dput (dentry); | |
1299 | dentry = NULL; | |
1300 | } | |
1301 | ||
1302 | if (dentry && dentry->d_inode) | |
1303 | reiserfs_warning (s, "Created %s on %s - reserved for " | |
1304 | "xattr storage.", PRIVROOT_NAME, | |
1305 | reiserfs_bdevname (inode->i_sb)); | |
1306 | } else if (!dentry->d_inode) { | |
1307 | dput (dentry); | |
1308 | dentry = NULL; | |
1309 | } | |
1310 | } else | |
1311 | err = PTR_ERR (dentry); | |
1312 | ||
1313 | if (!err && dentry) { | |
1314 | s->s_root->d_op = &xattr_lookup_poison_ops; | |
1315 | reiserfs_mark_inode_private (dentry->d_inode); | |
1316 | REISERFS_SB(s)->priv_root = dentry; | |
1317 | } else if (!(mount_flags & MS_RDONLY)) { /* xattrs are unavailable */ | |
1318 | /* If we're read-only it just means that the dir hasn't been | |
1319 | * created. Not an error -- just no xattrs on the fs. We'll | |
1320 | * check again if we go read-write */ | |
1321 | reiserfs_warning (s, "xattrs/ACLs enabled and couldn't " | |
1322 | "find/create .reiserfs_priv. Failing mount."); | |
1323 | err = -EOPNOTSUPP; | |
1324 | } | |
1325 | } | |
1326 | ||
1327 | error: | |
1328 | /* This is only nonzero if there was an error initializing the xattr | |
1329 | * directory or if there is a condition where we don't support them. */ | |
1330 | if (err) { | |
1331 | clear_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt)); | |
1332 | clear_bit (REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt)); | |
1333 | clear_bit (REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt)); | |
1334 | } | |
1335 | ||
1336 | /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */ | |
1337 | s->s_flags = s->s_flags & ~MS_POSIXACL; | |
1338 | if (reiserfs_posixacl (s)) | |
1339 | s->s_flags |= MS_POSIXACL; | |
1340 | ||
1341 | return err; | |
1342 | } | |
1343 | ||
1344 | static int | |
1345 | __reiserfs_permission (struct inode *inode, int mask, struct nameidata *nd, | |
1346 | int need_lock) | |
1347 | { | |
1348 | umode_t mode = inode->i_mode; | |
1349 | ||
1350 | if (mask & MAY_WRITE) { | |
1351 | /* | |
1352 | * Nobody gets write access to a read-only fs. | |
1353 | */ | |
1354 | if (IS_RDONLY(inode) && | |
1355 | (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) | |
1356 | return -EROFS; | |
1357 | ||
1358 | /* | |
1359 | * Nobody gets write access to an immutable file. | |
1360 | */ | |
1361 | if (IS_IMMUTABLE(inode)) | |
1362 | return -EACCES; | |
1363 | } | |
1364 | ||
1365 | /* We don't do permission checks on the internal objects. | |
1366 | * Permissions are determined by the "owning" object. */ | |
1367 | if (is_reiserfs_priv_object (inode)) | |
1368 | return 0; | |
1369 | ||
1370 | if (current->fsuid == inode->i_uid) { | |
1371 | mode >>= 6; | |
1372 | #ifdef CONFIG_REISERFS_FS_POSIX_ACL | |
1373 | } else if (reiserfs_posixacl(inode->i_sb) && | |
1374 | get_inode_sd_version (inode) != STAT_DATA_V1) { | |
1375 | struct posix_acl *acl; | |
1376 | ||
1377 | /* ACL can't contain additional permissions if | |
1378 | the ACL_MASK entry is 0 */ | |
1379 | if (!(mode & S_IRWXG)) | |
1380 | goto check_groups; | |
1381 | ||
1382 | if (need_lock) { | |
1383 | reiserfs_read_lock_xattr_i (inode); | |
1384 | reiserfs_read_lock_xattrs (inode->i_sb); | |
1385 | } | |
1386 | acl = reiserfs_get_acl (inode, ACL_TYPE_ACCESS); | |
1387 | if (need_lock) { | |
1388 | reiserfs_read_unlock_xattrs (inode->i_sb); | |
1389 | reiserfs_read_unlock_xattr_i (inode); | |
1390 | } | |
1391 | if (IS_ERR (acl)) { | |
1392 | if (PTR_ERR (acl) == -ENODATA) | |
1393 | goto check_groups; | |
1394 | return PTR_ERR (acl); | |
1395 | } | |
1396 | ||
1397 | if (acl) { | |
1398 | int err = posix_acl_permission (inode, acl, mask); | |
1399 | posix_acl_release (acl); | |
1400 | if (err == -EACCES) { | |
1401 | goto check_capabilities; | |
1402 | } | |
1403 | return err; | |
1404 | } else { | |
1405 | goto check_groups; | |
1406 | } | |
1407 | #endif | |
1408 | } else { | |
1409 | check_groups: | |
1410 | if (in_group_p(inode->i_gid)) | |
1411 | mode >>= 3; | |
1412 | } | |
1413 | ||
1414 | /* | |
1415 | * If the DACs are ok we don't need any capability check. | |
1416 | */ | |
1417 | if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask)) | |
1418 | return 0; | |
1419 | ||
1420 | check_capabilities: | |
1421 | /* | |
1422 | * Read/write DACs are always overridable. | |
1423 | * Executable DACs are overridable if at least one exec bit is set. | |
1424 | */ | |
1425 | if (!(mask & MAY_EXEC) || | |
1426 | (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode)) | |
1427 | if (capable(CAP_DAC_OVERRIDE)) | |
1428 | return 0; | |
1429 | ||
1430 | /* | |
1431 | * Searching includes executable on directories, else just read. | |
1432 | */ | |
1433 | if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE))) | |
1434 | if (capable(CAP_DAC_READ_SEARCH)) | |
1435 | return 0; | |
1436 | ||
1437 | return -EACCES; | |
1438 | } | |
1439 | ||
1440 | int | |
1441 | reiserfs_permission (struct inode *inode, int mask, struct nameidata *nd) | |
1442 | { | |
1443 | return __reiserfs_permission (inode, mask, nd, 1); | |
1444 | } | |
1445 | ||
1446 | int | |
1447 | reiserfs_permission_locked (struct inode *inode, int mask, struct nameidata *nd) | |
1448 | { | |
1449 | return __reiserfs_permission (inode, mask, nd, 0); | |
1450 | } |