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 /* Newly created object.. Need to mark it private */
185 REISERFS_I(xadir->d_inode)->i_flags |= i_priv_object;
186 }
187
188 dput (xaroot);
189 return xadir;
190 }
191
192 /* Returns a dentry corresponding to a specific extended attribute file
193 * for the inode. If flags allow, the file is created. Otherwise, a
194 * valid or negative dentry, or an error is returned. */
195 static struct dentry *
196 get_xa_file_dentry (const struct inode *inode, const char *name, int flags)
197 {
198 struct dentry *xadir, *xafile;
199 int err = 0;
200
201 xadir = open_xa_dir (inode, flags);
202 if (IS_ERR (xadir)) {
203 return ERR_PTR (PTR_ERR (xadir));
204 } else if (xadir && !xadir->d_inode) {
205 dput (xadir);
206 return ERR_PTR (-ENODATA);
207 }
208
209 xafile = lookup_one_len (name, xadir, strlen (name));
210 if (IS_ERR (xafile)) {
211 dput (xadir);
212 return ERR_PTR (PTR_ERR (xafile));
213 }
214
215 if (xafile->d_inode) { /* file exists */
216 if (flags & XATTR_CREATE) {
217 err = -EEXIST;
218 dput (xafile);
219 goto out;
220 }
221 } else if (flags & XATTR_REPLACE || flags & FL_READONLY) {
222 goto out;
223 } else {
224 /* inode->i_sem is down, so nothing else can try to create
225 * the same xattr */
226 err = xadir->d_inode->i_op->create (xadir->d_inode, xafile,
227 0700|S_IFREG, NULL);
228
229 if (err) {
230 dput (xafile);
231 goto out;
232 }
233 /* Newly created object.. Need to mark it private */
234 REISERFS_I(xafile->d_inode)->i_flags |= i_priv_object;
235 }
236
237 out:
238 dput (xadir);
239 if (err)
240 xafile = ERR_PTR (err);
241 return xafile;
242 }
243
244
245 /* Opens a file pointer to the attribute associated with inode */
246 static struct file *
247 open_xa_file (const struct inode *inode, const char *name, int flags)
248 {
249 struct dentry *xafile;
250 struct file *fp;
251
252 xafile = get_xa_file_dentry (inode, name, flags);
253 if (IS_ERR (xafile))
254 return ERR_PTR (PTR_ERR (xafile));
255 else if (!xafile->d_inode) {
256 dput (xafile);
257 return ERR_PTR (-ENODATA);
258 }
259
260 fp = dentry_open (xafile, NULL, O_RDWR);
261 /* dentry_open dputs the dentry if it fails */
262
263 return fp;
264 }
265
266
267 /*
268 * this is very similar to fs/reiserfs/dir.c:reiserfs_readdir, but
269 * we need to drop the path before calling the filldir struct. That
270 * would be a big performance hit to the non-xattr case, so I've copied
271 * the whole thing for now. --clm
272 *
273 * the big difference is that I go backwards through the directory,
274 * and don't mess with f->f_pos, but the idea is the same. Do some
275 * action on each and every entry in the directory.
276 *
277 * we're called with i_sem held, so there are no worries about the directory
278 * changing underneath us.
279 */
280 static int __xattr_readdir(struct file * filp, void * dirent, filldir_t filldir)
281 {
282 struct inode *inode = filp->f_dentry->d_inode;
283 struct cpu_key pos_key; /* key of current position in the directory (key of directory entry) */
284 INITIALIZE_PATH (path_to_entry);
285 struct buffer_head * bh;
286 int entry_num;
287 struct item_head * ih, tmp_ih;
288 int search_res;
289 char * local_buf;
290 loff_t next_pos;
291 char small_buf[32] ; /* avoid kmalloc if we can */
292 struct reiserfs_de_head *deh;
293 int d_reclen;
294 char * d_name;
295 off_t d_off;
296 ino_t d_ino;
297 struct reiserfs_dir_entry de;
298
299
300 /* form key for search the next directory entry using f_pos field of
301 file structure */
302 next_pos = max_reiserfs_offset(inode);
303
304 while (1) {
305 research:
306 if (next_pos <= DOT_DOT_OFFSET)
307 break;
308 make_cpu_key (&pos_key, inode, next_pos, TYPE_DIRENTRY, 3);
309
310 search_res = search_by_entry_key(inode->i_sb, &pos_key, &path_to_entry, &de);
311 if (search_res == IO_ERROR) {
312 // FIXME: we could just skip part of directory which could
313 // not be read
314 pathrelse(&path_to_entry);
315 return -EIO;
316 }
317
318 if (search_res == NAME_NOT_FOUND)
319 de.de_entry_num--;
320
321 set_de_name_and_namelen(&de);
322 entry_num = de.de_entry_num;
323 deh = &(de.de_deh[entry_num]);
324
325 bh = de.de_bh;
326 ih = de.de_ih;
327
328 if (!is_direntry_le_ih(ih)) {
329 reiserfs_warning(inode->i_sb, "not direntry %h", ih);
330 break;
331 }
332 copy_item_head(&tmp_ih, ih);
333
334 /* we must have found item, that is item of this directory, */
335 RFALSE( COMP_SHORT_KEYS (&(ih->ih_key), &pos_key),
336 "vs-9000: found item %h does not match to dir we readdir %K",
337 ih, &pos_key);
338
339 if (deh_offset(deh) <= DOT_DOT_OFFSET) {
340 break;
341 }
342
343 /* look for the previous entry in the directory */
344 next_pos = deh_offset (deh) - 1;
345
346 if (!de_visible (deh))
347 /* it is hidden entry */
348 continue;
349
350 d_reclen = entry_length(bh, ih, entry_num);
351 d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh);
352 d_off = deh_offset (deh);
353 d_ino = deh_objectid (deh);
354
355 if (!d_name[d_reclen - 1])
356 d_reclen = strlen (d_name);
357
358 if (d_reclen > REISERFS_MAX_NAME(inode->i_sb->s_blocksize)){
359 /* too big to send back to VFS */
360 continue ;
361 }
362
363 /* Ignore the .reiserfs_priv entry */
364 if (reiserfs_xattrs (inode->i_sb) &&
365 !old_format_only(inode->i_sb) &&
366 deh_objectid (deh) == le32_to_cpu (INODE_PKEY(REISERFS_SB(inode->i_sb)->priv_root->d_inode)->k_objectid))
367 continue;
368
369 if (d_reclen <= 32) {
370 local_buf = small_buf ;
371 } else {
372 local_buf = reiserfs_kmalloc(d_reclen, GFP_NOFS, inode->i_sb) ;
373 if (!local_buf) {
374 pathrelse (&path_to_entry);
375 return -ENOMEM ;
376 }
377 if (item_moved (&tmp_ih, &path_to_entry)) {
378 reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
379
380 /* sigh, must retry. Do this same offset again */
381 next_pos = d_off;
382 goto research;
383 }
384 }
385
386 // Note, that we copy name to user space via temporary
387 // buffer (local_buf) because filldir will block if
388 // user space buffer is swapped out. At that time
389 // entry can move to somewhere else
390 memcpy (local_buf, d_name, d_reclen);
391
392 /* the filldir function might need to start transactions,
393 * or do who knows what. Release the path now that we've
394 * copied all the important stuff out of the deh
395 */
396 pathrelse (&path_to_entry);
397
398 if (filldir (dirent, local_buf, d_reclen, d_off, d_ino,
399 DT_UNKNOWN) < 0) {
400 if (local_buf != small_buf) {
401 reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
402 }
403 goto end;
404 }
405 if (local_buf != small_buf) {
406 reiserfs_kfree(local_buf, d_reclen, inode->i_sb) ;
407 }
408 } /* while */
409
410 end:
411 pathrelse (&path_to_entry);
412 return 0;
413 }
414
415 /*
416 * this could be done with dedicated readdir ops for the xattr files,
417 * but I want to get something working asap
418 * this is stolen from vfs_readdir
419 *
420 */
421 static
422 int xattr_readdir(struct file *file, filldir_t filler, void *buf)
423 {
424 struct inode *inode = file->f_dentry->d_inode;
425 int res = -ENOTDIR;
426 if (!file->f_op || !file->f_op->readdir)
427 goto out;
428 down(&inode->i_sem);
429 // down(&inode->i_zombie);
430 res = -ENOENT;
431 if (!IS_DEADDIR(inode)) {
432 lock_kernel();
433 res = __xattr_readdir(file, buf, filler);
434 unlock_kernel();
435 }
436 // up(&inode->i_zombie);
437 up(&inode->i_sem);
438 out:
439 return res;
440 }
441
442
443 /* Internal operations on file data */
444 static inline void
445 reiserfs_put_page(struct page *page)
446 {
447 kunmap(page);
448 page_cache_release(page);
449 }
450
451 static struct page *
452 reiserfs_get_page(struct inode *dir, unsigned long n)
453 {
454 struct address_space *mapping = dir->i_mapping;
455 struct page *page;
456 /* We can deadlock if we try to free dentries,
457 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
458 mapping->flags = (mapping->flags & ~__GFP_BITS_MASK) | GFP_NOFS;
459 page = read_cache_page (mapping, n,
460 (filler_t*)mapping->a_ops->readpage, NULL);
461 if (!IS_ERR(page)) {
462 wait_on_page_locked(page);
463 kmap(page);
464 if (!PageUptodate(page))
465 goto fail;
466
467 if (PageError(page))
468 goto fail;
469 }
470 return page;
471
472 fail:
473 reiserfs_put_page(page);
474 return ERR_PTR(-EIO);
475 }
476
477 static inline __u32
478 xattr_hash (const char *msg, int len)
479 {
480 return csum_partial (msg, len, 0);
481 }
482
483 /* Generic extended attribute operations that can be used by xa plugins */
484
485 /*
486 * inode->i_sem: down
487 */
488 int
489 reiserfs_xattr_set (struct inode *inode, const char *name, const void *buffer,
490 size_t buffer_size, int flags)
491 {
492 int err = 0;
493 struct file *fp;
494 struct page *page;
495 char *data;
496 struct address_space *mapping;
497 size_t file_pos = 0;
498 size_t buffer_pos = 0;
499 struct inode *xinode;
500 struct iattr newattrs;
501 __u32 xahash = 0;
502
503 if (IS_RDONLY (inode))
504 return -EROFS;
505
506 if (IS_IMMUTABLE (inode) || IS_APPEND (inode))
507 return -EPERM;
508
509 if (get_inode_sd_version (inode) == STAT_DATA_V1)
510 return -EOPNOTSUPP;
511
512 /* Empty xattrs are ok, they're just empty files, no hash */
513 if (buffer && buffer_size)
514 xahash = xattr_hash (buffer, buffer_size);
515
516 open_file:
517 fp = open_xa_file (inode, name, flags);
518 if (IS_ERR (fp)) {
519 err = PTR_ERR (fp);
520 goto out;
521 }
522
523 xinode = fp->f_dentry->d_inode;
524 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
525
526 /* we need to copy it off.. */
527 if (xinode->i_nlink > 1) {
528 fput(fp);
529 err = reiserfs_xattr_del (inode, name);
530 if (err < 0)
531 goto out;
532 /* We just killed the old one, we're not replacing anymore */
533 if (flags & XATTR_REPLACE)
534 flags &= ~XATTR_REPLACE;
535 goto open_file;
536 }
537
538 /* Resize it so we're ok to write there */
539 newattrs.ia_size = buffer_size;
540 newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME;
541 down (&xinode->i_sem);
542 err = notify_change(fp->f_dentry, &newattrs);
543 if (err)
544 goto out_filp;
545
546 mapping = xinode->i_mapping;
547 while (buffer_pos < buffer_size || buffer_pos == 0) {
548 size_t chunk;
549 size_t skip = 0;
550 size_t page_offset = (file_pos & (PAGE_CACHE_SIZE - 1));
551 if (buffer_size - buffer_pos > PAGE_CACHE_SIZE)
552 chunk = PAGE_CACHE_SIZE;
553 else
554 chunk = buffer_size - buffer_pos;
555
556 page = reiserfs_get_page (xinode, file_pos >> PAGE_CACHE_SHIFT);
557 if (IS_ERR (page)) {
558 err = PTR_ERR (page);
559 goto out_filp;
560 }
561
562 lock_page (page);
563 data = page_address (page);
564
565 if (file_pos == 0) {
566 struct reiserfs_xattr_header *rxh;
567 skip = file_pos = sizeof (struct reiserfs_xattr_header);
568 if (chunk + skip > PAGE_CACHE_SIZE)
569 chunk = PAGE_CACHE_SIZE - skip;
570 rxh = (struct reiserfs_xattr_header *)data;
571 rxh->h_magic = cpu_to_le32 (REISERFS_XATTR_MAGIC);
572 rxh->h_hash = cpu_to_le32 (xahash);
573 }
574
575 err = mapping->a_ops->prepare_write (fp, page, page_offset,
576 page_offset + chunk + skip);
577 if (!err) {
578 if (buffer)
579 memcpy (data + skip, buffer + buffer_pos, chunk);
580 err = mapping->a_ops->commit_write (fp, page, page_offset,
581 page_offset + chunk + skip);
582 }
583 unlock_page (page);
584 reiserfs_put_page (page);
585 buffer_pos += chunk;
586 file_pos += chunk;
587 skip = 0;
588 if (err || buffer_size == 0 || !buffer)
589 break;
590 }
591
592 /* We can't mark the inode dirty if it's not hashed. This is the case
593 * when we're inheriting the default ACL. If we dirty it, the inode
594 * gets marked dirty, but won't (ever) make it onto the dirty list until
595 * it's synced explicitly to clear I_DIRTY. This is bad. */
596 if (!hlist_unhashed(&inode->i_hash)) {
597 inode->i_ctime = CURRENT_TIME_SEC;
598 mark_inode_dirty (inode);
599 }
600
601 out_filp:
602 up (&xinode->i_sem);
603 fput(fp);
604
605 out:
606 return err;
607 }
608
609 /*
610 * inode->i_sem: down
611 */
612 int
613 reiserfs_xattr_get (const struct inode *inode, const char *name, void *buffer,
614 size_t buffer_size)
615 {
616 ssize_t err = 0;
617 struct file *fp;
618 size_t isize;
619 size_t file_pos = 0;
620 size_t buffer_pos = 0;
621 struct page *page;
622 struct inode *xinode;
623 __u32 hash = 0;
624
625 if (name == NULL)
626 return -EINVAL;
627
628 /* We can't have xattrs attached to v1 items since they don't have
629 * generation numbers */
630 if (get_inode_sd_version (inode) == STAT_DATA_V1)
631 return -EOPNOTSUPP;
632
633 fp = open_xa_file (inode, name, FL_READONLY);
634 if (IS_ERR (fp)) {
635 err = PTR_ERR (fp);
636 goto out;
637 }
638
639 xinode = fp->f_dentry->d_inode;
640 isize = xinode->i_size;
641 REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
642
643 /* Just return the size needed */
644 if (buffer == NULL) {
645 err = isize - sizeof (struct reiserfs_xattr_header);
646 goto out_dput;
647 }
648
649 if (buffer_size < isize - sizeof (struct reiserfs_xattr_header)) {
650 err = -ERANGE;
651 goto out_dput;
652 }
653
654 while (file_pos < isize) {
655 size_t chunk;
656 char *data;
657 size_t skip = 0;
658 if (isize - file_pos > PAGE_CACHE_SIZE)
659 chunk = PAGE_CACHE_SIZE;
660 else
661 chunk = isize - file_pos;
662
663 page = reiserfs_get_page (xinode, file_pos >> PAGE_CACHE_SHIFT);
664 if (IS_ERR (page)) {
665 err = PTR_ERR (page);
666 goto out_dput;
667 }
668
669 lock_page (page);
670 data = page_address (page);
671 if (file_pos == 0) {
672 struct reiserfs_xattr_header *rxh =
673 (struct reiserfs_xattr_header *)data;
674 skip = file_pos = sizeof (struct reiserfs_xattr_header);
675 chunk -= skip;
676 /* Magic doesn't match up.. */
677 if (rxh->h_magic != cpu_to_le32 (REISERFS_XATTR_MAGIC)) {
678 unlock_page (page);
679 reiserfs_put_page (page);
680 reiserfs_warning (inode->i_sb, "Invalid magic for xattr (%s) "
681 "associated with %k", name,
682 INODE_PKEY (inode));
683 err = -EIO;
684 goto out_dput;
685 }
686 hash = le32_to_cpu (rxh->h_hash);
687 }
688 memcpy (buffer + buffer_pos, data + skip, chunk);
689 unlock_page (page);
690 reiserfs_put_page (page);
691 file_pos += chunk;
692 buffer_pos += chunk;
693 skip = 0;
694 }
695 err = isize - sizeof (struct reiserfs_xattr_header);
696
697 if (xattr_hash (buffer, isize - sizeof (struct reiserfs_xattr_header)) != hash) {
698 reiserfs_warning (inode->i_sb, "Invalid hash for xattr (%s) associated "
699 "with %k", name, INODE_PKEY (inode));
700 err = -EIO;
701 }
702
703 out_dput:
704 fput(fp);
705
706 out:
707 return err;
708 }
709
710 static int
711 __reiserfs_xattr_del (struct dentry *xadir, const char *name, int namelen)
712 {
713 struct dentry *dentry;
714 struct inode *dir = xadir->d_inode;
715 int err = 0;
716
717 dentry = lookup_one_len (name, xadir, namelen);
718 if (IS_ERR (dentry)) {
719 err = PTR_ERR (dentry);
720 goto out;
721 } else if (!dentry->d_inode) {
722 err = -ENODATA;
723 goto out_file;
724 }
725
726 /* Skip directories.. */
727 if (S_ISDIR (dentry->d_inode->i_mode))
728 goto out_file;
729
730 if (!is_reiserfs_priv_object (dentry->d_inode)) {
731 reiserfs_warning (dir->i_sb, "OID %08x [%.*s/%.*s] doesn't have "
732 "priv flag set [parent is %sset].",
733 le32_to_cpu (INODE_PKEY (dentry->d_inode)->k_objectid),
734 xadir->d_name.len, xadir->d_name.name, namelen, name,
735 is_reiserfs_priv_object (xadir->d_inode) ? "" : "not ");
736 dput (dentry);
737 return -EIO;
738 }
739
740 err = dir->i_op->unlink (dir, dentry);
741 if (!err)
742 d_delete (dentry);
743
744 out_file:
745 dput (dentry);
746
747 out:
748 return err;
749 }
750
751
752 int
753 reiserfs_xattr_del (struct inode *inode, const char *name)
754 {
755 struct dentry *dir;
756 int err;
757
758 if (IS_RDONLY (inode))
759 return -EROFS;
760
761 dir = open_xa_dir (inode, FL_READONLY);
762 if (IS_ERR (dir)) {
763 err = PTR_ERR (dir);
764 goto out;
765 }
766
767 err = __reiserfs_xattr_del (dir, name, strlen (name));
768 dput (dir);
769
770 if (!err) {
771 inode->i_ctime = CURRENT_TIME_SEC;
772 mark_inode_dirty (inode);
773 }
774
775 out:
776 return err;
777 }
778
779 /* The following are side effects of other operations that aren't explicitly
780 * modifying extended attributes. This includes operations such as permissions
781 * or ownership changes, object deletions, etc. */
782
783 static int
784 reiserfs_delete_xattrs_filler (void *buf, const char *name, int namelen,
785 loff_t offset, ino_t ino, unsigned int d_type)
786 {
787 struct dentry *xadir = (struct dentry *)buf;
788
789 return __reiserfs_xattr_del (xadir, name, namelen);
790
791 }
792
793 /* This is called w/ inode->i_sem downed */
794 int
795 reiserfs_delete_xattrs (struct inode *inode)
796 {
797 struct file *fp;
798 struct dentry *dir, *root;
799 int err = 0;
800
801 /* Skip out, an xattr has no xattrs associated with it */
802 if (is_reiserfs_priv_object (inode) ||
803 get_inode_sd_version (inode) == STAT_DATA_V1 ||
804 !reiserfs_xattrs(inode->i_sb))
805 {
806 return 0;
807 }
808 reiserfs_read_lock_xattrs (inode->i_sb);
809 dir = open_xa_dir (inode, FL_READONLY);
810 reiserfs_read_unlock_xattrs (inode->i_sb);
811 if (IS_ERR (dir)) {
812 err = PTR_ERR (dir);
813 goto out;
814 } else if (!dir->d_inode) {
815 dput (dir);
816 return 0;
817 }
818
819 fp = dentry_open (dir, NULL, O_RDWR);
820 if (IS_ERR (fp)) {
821 err = PTR_ERR (fp);
822 /* dentry_open dputs the dentry if it fails */
823 goto out;
824 }
825
826 lock_kernel ();
827 err = xattr_readdir (fp, reiserfs_delete_xattrs_filler, dir);
828 if (err) {
829 unlock_kernel ();
830 goto out_dir;
831 }
832
833 /* Leftovers besides . and .. -- that's not good. */
834 if (dir->d_inode->i_nlink <= 2) {
835 root = get_xa_root (inode->i_sb);
836 reiserfs_write_lock_xattrs (inode->i_sb);
837 err = vfs_rmdir (root->d_inode, dir);
838 reiserfs_write_unlock_xattrs (inode->i_sb);
839 dput (root);
840 } else {
841 reiserfs_warning (inode->i_sb,
842 "Couldn't remove all entries in directory");
843 }
844 unlock_kernel ();
845
846 out_dir:
847 fput(fp);
848
849 out:
850 if (!err)
851 REISERFS_I(inode)->i_flags = REISERFS_I(inode)->i_flags & ~i_has_xattr_dir;
852 return err;
853 }
854
855 struct reiserfs_chown_buf {
856 struct inode *inode;
857 struct dentry *xadir;
858 struct iattr *attrs;
859 };
860
861 /* XXX: If there is a better way to do this, I'd love to hear about it */
862 static int
863 reiserfs_chown_xattrs_filler (void *buf, const char *name, int namelen,
864 loff_t offset, ino_t ino, unsigned int d_type)
865 {
866 struct reiserfs_chown_buf *chown_buf = (struct reiserfs_chown_buf *)buf;
867 struct dentry *xafile, *xadir = chown_buf->xadir;
868 struct iattr *attrs = chown_buf->attrs;
869 int err = 0;
870
871 xafile = lookup_one_len (name, xadir, namelen);
872 if (IS_ERR (xafile))
873 return PTR_ERR (xafile);
874 else if (!xafile->d_inode) {
875 dput (xafile);
876 return -ENODATA;
877 }
878
879 if (!S_ISDIR (xafile->d_inode->i_mode))
880 err = notify_change (xafile, attrs);
881 dput (xafile);
882
883 return err;
884 }
885
886 int
887 reiserfs_chown_xattrs (struct inode *inode, struct iattr *attrs)
888 {
889 struct file *fp;
890 struct dentry *dir;
891 int err = 0;
892 struct reiserfs_chown_buf buf;
893 unsigned int ia_valid = attrs->ia_valid;
894
895 /* Skip out, an xattr has no xattrs associated with it */
896 if (is_reiserfs_priv_object (inode) ||
897 get_inode_sd_version (inode) == STAT_DATA_V1 ||
898 !reiserfs_xattrs(inode->i_sb))
899 {
900 return 0;
901 }
902 reiserfs_read_lock_xattrs (inode->i_sb);
903 dir = open_xa_dir (inode, FL_READONLY);
904 reiserfs_read_unlock_xattrs (inode->i_sb);
905 if (IS_ERR (dir)) {
906 if (PTR_ERR (dir) != -ENODATA)
907 err = PTR_ERR (dir);
908 goto out;
909 } else if (!dir->d_inode) {
910 dput (dir);
911 goto out;
912 }
913
914 fp = dentry_open (dir, NULL, O_RDWR);
915 if (IS_ERR (fp)) {
916 err = PTR_ERR (fp);
917 /* dentry_open dputs the dentry if it fails */
918 goto out;
919 }
920
921 lock_kernel ();
922
923 attrs->ia_valid &= (ATTR_UID | ATTR_GID | ATTR_CTIME);
924 buf.xadir = dir;
925 buf.attrs = attrs;
926 buf.inode = inode;
927
928 err = xattr_readdir (fp, reiserfs_chown_xattrs_filler, &buf);
929 if (err) {
930 unlock_kernel ();
931 goto out_dir;
932 }
933
934 err = notify_change (dir, attrs);
935 unlock_kernel ();
936
937 out_dir:
938 fput(fp);
939
940 out:
941 attrs->ia_valid = ia_valid;
942 return err;
943 }
944
945
946 /* Actual operations that are exported to VFS-land */
947
948 /*
949 * Inode operation getxattr()
950 * Preliminary locking: we down dentry->d_inode->i_sem
951 */
952 ssize_t
953 reiserfs_getxattr (struct dentry *dentry, const char *name, void *buffer,
954 size_t size)
955 {
956 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
957 int err;
958
959 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
960 get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
961 return -EOPNOTSUPP;
962
963 reiserfs_read_lock_xattr_i (dentry->d_inode);
964 reiserfs_read_lock_xattrs (dentry->d_sb);
965 err = xah->get (dentry->d_inode, name, buffer, size);
966 reiserfs_read_unlock_xattrs (dentry->d_sb);
967 reiserfs_read_unlock_xattr_i (dentry->d_inode);
968 return err;
969 }
970
971
972 /*
973 * Inode operation setxattr()
974 *
975 * dentry->d_inode->i_sem down
976 */
977 int
978 reiserfs_setxattr (struct dentry *dentry, const char *name, const void *value,
979 size_t size, int flags)
980 {
981 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
982 int err;
983 int lock;
984
985 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
986 get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
987 return -EOPNOTSUPP;
988
989 if (IS_RDONLY (dentry->d_inode))
990 return -EROFS;
991
992 if (IS_IMMUTABLE (dentry->d_inode) || IS_APPEND (dentry->d_inode))
993 return -EROFS;
994
995 reiserfs_write_lock_xattr_i (dentry->d_inode);
996 lock = !has_xattr_dir (dentry->d_inode);
997 if (lock)
998 reiserfs_write_lock_xattrs (dentry->d_sb);
999 else
1000 reiserfs_read_lock_xattrs (dentry->d_sb);
1001 err = xah->set (dentry->d_inode, name, value, size, flags);
1002 if (lock)
1003 reiserfs_write_unlock_xattrs (dentry->d_sb);
1004 else
1005 reiserfs_read_unlock_xattrs (dentry->d_sb);
1006 reiserfs_write_unlock_xattr_i (dentry->d_inode);
1007 return err;
1008 }
1009
1010 /*
1011 * Inode operation removexattr()
1012 *
1013 * dentry->d_inode->i_sem down
1014 */
1015 int
1016 reiserfs_removexattr (struct dentry *dentry, const char *name)
1017 {
1018 int err;
1019 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
1020
1021 if (!xah || !reiserfs_xattrs(dentry->d_sb) ||
1022 get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
1023 return -EOPNOTSUPP;
1024
1025 if (IS_RDONLY (dentry->d_inode))
1026 return -EROFS;
1027
1028 if (IS_IMMUTABLE (dentry->d_inode) || IS_APPEND (dentry->d_inode))
1029 return -EPERM;
1030
1031 reiserfs_write_lock_xattr_i (dentry->d_inode);
1032 reiserfs_read_lock_xattrs (dentry->d_sb);
1033
1034 /* Deletion pre-operation */
1035 if (xah->del) {
1036 err = xah->del (dentry->d_inode, name);
1037 if (err)
1038 goto out;
1039 }
1040
1041 err = reiserfs_xattr_del (dentry->d_inode, name);
1042
1043 dentry->d_inode->i_ctime = CURRENT_TIME_SEC;
1044 mark_inode_dirty (dentry->d_inode);
1045
1046 out:
1047 reiserfs_read_unlock_xattrs (dentry->d_sb);
1048 reiserfs_write_unlock_xattr_i (dentry->d_inode);
1049 return err;
1050 }
1051
1052
1053 /* This is what filldir will use:
1054 * r_pos will always contain the amount of space required for the entire
1055 * list. If r_pos becomes larger than r_size, we need more space and we
1056 * return an error indicating this. If r_pos is less than r_size, then we've
1057 * filled the buffer successfully and we return success */
1058 struct reiserfs_listxattr_buf {
1059 int r_pos;
1060 int r_size;
1061 char *r_buf;
1062 struct inode *r_inode;
1063 };
1064
1065 static int
1066 reiserfs_listxattr_filler (void *buf, const char *name, int namelen,
1067 loff_t offset, ino_t ino, unsigned int d_type)
1068 {
1069 struct reiserfs_listxattr_buf *b = (struct reiserfs_listxattr_buf *)buf;
1070 int len = 0;
1071 if (name[0] != '.' || (namelen != 1 && (name[1] != '.' || namelen != 2))) {
1072 struct reiserfs_xattr_handler *xah = find_xattr_handler_prefix (name);
1073 if (!xah) return 0; /* Unsupported xattr name, skip it */
1074
1075 /* We call ->list() twice because the operation isn't required to just
1076 * return the name back - we want to make sure we have enough space */
1077 len += xah->list (b->r_inode, name, namelen, NULL);
1078
1079 if (len) {
1080 if (b->r_pos + len + 1 <= b->r_size) {
1081 char *p = b->r_buf + b->r_pos;
1082 p += xah->list (b->r_inode, name, namelen, p);
1083 *p++ = '\0';
1084 }
1085 b->r_pos += len + 1;
1086 }
1087 }
1088
1089 return 0;
1090 }
1091 /*
1092 * Inode operation listxattr()
1093 *
1094 * Preliminary locking: we down dentry->d_inode->i_sem
1095 */
1096 ssize_t
1097 reiserfs_listxattr (struct dentry *dentry, char *buffer, size_t size)
1098 {
1099 struct file *fp;
1100 struct dentry *dir;
1101 int err = 0;
1102 struct reiserfs_listxattr_buf buf;
1103
1104 if (!dentry->d_inode)
1105 return -EINVAL;
1106
1107 if (!reiserfs_xattrs(dentry->d_sb) ||
1108 get_inode_sd_version (dentry->d_inode) == STAT_DATA_V1)
1109 return -EOPNOTSUPP;
1110
1111 reiserfs_read_lock_xattr_i (dentry->d_inode);
1112 reiserfs_read_lock_xattrs (dentry->d_sb);
1113 dir = open_xa_dir (dentry->d_inode, FL_READONLY);
1114 reiserfs_read_unlock_xattrs (dentry->d_sb);
1115 if (IS_ERR (dir)) {
1116 err = PTR_ERR (dir);
1117 if (err == -ENODATA)
1118 err = 0; /* Not an error if there aren't any xattrs */
1119 goto out;
1120 }
1121
1122 fp = dentry_open (dir, NULL, O_RDWR);
1123 if (IS_ERR (fp)) {
1124 err = PTR_ERR (fp);
1125 /* dentry_open dputs the dentry if it fails */
1126 goto out;
1127 }
1128
1129 buf.r_buf = buffer;
1130 buf.r_size = buffer ? size : 0;
1131 buf.r_pos = 0;
1132 buf.r_inode = dentry->d_inode;
1133
1134 REISERFS_I(dentry->d_inode)->i_flags |= i_has_xattr_dir;
1135
1136 err = xattr_readdir (fp, reiserfs_listxattr_filler, &buf);
1137 if (err)
1138 goto out_dir;
1139
1140 if (buf.r_pos > buf.r_size && buffer != NULL)
1141 err = -ERANGE;
1142 else
1143 err = buf.r_pos;
1144
1145 out_dir:
1146 fput(fp);
1147
1148 out:
1149 reiserfs_read_unlock_xattr_i (dentry->d_inode);
1150 return err;
1151 }
1152
1153 /* This is the implementation for the xattr plugin infrastructure */
1154 static struct list_head xattr_handlers = LIST_HEAD_INIT (xattr_handlers);
1155 static DEFINE_RWLOCK(handler_lock);
1156
1157 static struct reiserfs_xattr_handler *
1158 find_xattr_handler_prefix (const char *prefix)
1159 {
1160 struct reiserfs_xattr_handler *xah = NULL;
1161 struct list_head *p;
1162
1163 read_lock (&handler_lock);
1164 list_for_each (p, &xattr_handlers) {
1165 xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
1166 if (strncmp (xah->prefix, prefix, strlen (xah->prefix)) == 0)
1167 break;
1168 xah = NULL;
1169 }
1170
1171 read_unlock (&handler_lock);
1172 return xah;
1173 }
1174
1175 static void
1176 __unregister_handlers (void)
1177 {
1178 struct reiserfs_xattr_handler *xah;
1179 struct list_head *p, *tmp;
1180
1181 list_for_each_safe (p, tmp, &xattr_handlers) {
1182 xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
1183 if (xah->exit)
1184 xah->exit();
1185
1186 list_del_init (p);
1187 }
1188 INIT_LIST_HEAD (&xattr_handlers);
1189 }
1190
1191 int __init
1192 reiserfs_xattr_register_handlers (void)
1193 {
1194 int err = 0;
1195 struct reiserfs_xattr_handler *xah;
1196 struct list_head *p;
1197
1198 write_lock (&handler_lock);
1199
1200 /* If we're already initialized, nothing to do */
1201 if (!list_empty (&xattr_handlers)) {
1202 write_unlock (&handler_lock);
1203 return 0;
1204 }
1205
1206 /* Add the handlers */
1207 list_add_tail (&user_handler.handlers, &xattr_handlers);
1208 list_add_tail (&trusted_handler.handlers, &xattr_handlers);
1209 #ifdef CONFIG_REISERFS_FS_SECURITY
1210 list_add_tail (&security_handler.handlers, &xattr_handlers);
1211 #endif
1212 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1213 list_add_tail (&posix_acl_access_handler.handlers, &xattr_handlers);
1214 list_add_tail (&posix_acl_default_handler.handlers, &xattr_handlers);
1215 #endif
1216
1217 /* Run initializers, if available */
1218 list_for_each (p, &xattr_handlers) {
1219 xah = list_entry (p, struct reiserfs_xattr_handler, handlers);
1220 if (xah->init) {
1221 err = xah->init ();
1222 if (err) {
1223 list_del_init (p);
1224 break;
1225 }
1226 }
1227 }
1228
1229 /* Clean up other handlers, if any failed */
1230 if (err)
1231 __unregister_handlers ();
1232
1233 write_unlock (&handler_lock);
1234 return err;
1235 }
1236
1237 void
1238 reiserfs_xattr_unregister_handlers (void)
1239 {
1240 write_lock (&handler_lock);
1241 __unregister_handlers ();
1242 write_unlock (&handler_lock);
1243 }
1244
1245 /* This will catch lookups from the fs root to .reiserfs_priv */
1246 static int
1247 xattr_lookup_poison (struct dentry *dentry, struct qstr *q1, struct qstr *name)
1248 {
1249 struct dentry *priv_root = REISERFS_SB(dentry->d_sb)->priv_root;
1250 if (name->len == priv_root->d_name.len &&
1251 name->hash == priv_root->d_name.hash &&
1252 !memcmp (name->name, priv_root->d_name.name, name->len)) {
1253 return -ENOENT;
1254 } else if (q1->len == name->len &&
1255 !memcmp(q1->name, name->name, name->len))
1256 return 0;
1257 return 1;
1258 }
1259
1260 static struct dentry_operations xattr_lookup_poison_ops = {
1261 .d_compare = xattr_lookup_poison,
1262 };
1263
1264
1265 /* We need to take a copy of the mount flags since things like
1266 * MS_RDONLY don't get set until *after* we're called.
1267 * mount_flags != mount_options */
1268 int
1269 reiserfs_xattr_init (struct super_block *s, int mount_flags)
1270 {
1271 int err = 0;
1272
1273 /* We need generation numbers to ensure that the oid mapping is correct
1274 * v3.5 filesystems don't have them. */
1275 if (!old_format_only (s)) {
1276 set_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1277 } else if (reiserfs_xattrs_optional (s)) {
1278 /* Old format filesystem, but optional xattrs have been enabled
1279 * at mount time. Error out. */
1280 reiserfs_warning (s, "xattrs/ACLs not supported on pre v3.6 "
1281 "format filesystem. Failing mount.");
1282 err = -EOPNOTSUPP;
1283 goto error;
1284 } else {
1285 /* Old format filesystem, but no optional xattrs have been enabled. This
1286 * means we silently disable xattrs on the filesystem. */
1287 clear_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1288 }
1289
1290 /* If we don't have the privroot located yet - go find it */
1291 if (reiserfs_xattrs (s) && !REISERFS_SB(s)->priv_root) {
1292 struct dentry *dentry;
1293 dentry = lookup_one_len (PRIVROOT_NAME, s->s_root,
1294 strlen (PRIVROOT_NAME));
1295 if (!IS_ERR (dentry)) {
1296 if (!(mount_flags & MS_RDONLY) && !dentry->d_inode) {
1297 struct inode *inode = dentry->d_parent->d_inode;
1298 down (&inode->i_sem);
1299 err = inode->i_op->mkdir (inode, dentry, 0700);
1300 up (&inode->i_sem);
1301 if (err) {
1302 dput (dentry);
1303 dentry = NULL;
1304 }
1305
1306 if (dentry && dentry->d_inode)
1307 reiserfs_warning (s, "Created %s on %s - reserved for "
1308 "xattr storage.", PRIVROOT_NAME,
1309 reiserfs_bdevname (inode->i_sb));
1310 } else if (!dentry->d_inode) {
1311 dput (dentry);
1312 dentry = NULL;
1313 }
1314 } else
1315 err = PTR_ERR (dentry);
1316
1317 if (!err && dentry) {
1318 s->s_root->d_op = &xattr_lookup_poison_ops;
1319 REISERFS_I(dentry->d_inode)->i_flags |= i_priv_object;
1320 REISERFS_SB(s)->priv_root = dentry;
1321 } else if (!(mount_flags & MS_RDONLY)) { /* xattrs are unavailable */
1322 /* If we're read-only it just means that the dir hasn't been
1323 * created. Not an error -- just no xattrs on the fs. We'll
1324 * check again if we go read-write */
1325 reiserfs_warning (s, "xattrs/ACLs enabled and couldn't "
1326 "find/create .reiserfs_priv. Failing mount.");
1327 err = -EOPNOTSUPP;
1328 }
1329 }
1330
1331 error:
1332 /* This is only nonzero if there was an error initializing the xattr
1333 * directory or if there is a condition where we don't support them. */
1334 if (err) {
1335 clear_bit (REISERFS_XATTRS, &(REISERFS_SB(s)->s_mount_opt));
1336 clear_bit (REISERFS_XATTRS_USER, &(REISERFS_SB(s)->s_mount_opt));
1337 clear_bit (REISERFS_POSIXACL, &(REISERFS_SB(s)->s_mount_opt));
1338 }
1339
1340 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1341 s->s_flags = s->s_flags & ~MS_POSIXACL;
1342 if (reiserfs_posixacl (s))
1343 s->s_flags |= MS_POSIXACL;
1344
1345 return err;
1346 }
1347
1348 static int
1349 __reiserfs_permission (struct inode *inode, int mask, struct nameidata *nd,
1350 int need_lock)
1351 {
1352 umode_t mode = inode->i_mode;
1353
1354 if (mask & MAY_WRITE) {
1355 /*
1356 * Nobody gets write access to a read-only fs.
1357 */
1358 if (IS_RDONLY(inode) &&
1359 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
1360 return -EROFS;
1361
1362 /*
1363 * Nobody gets write access to an immutable file.
1364 */
1365 if (IS_IMMUTABLE(inode))
1366 return -EACCES;
1367 }
1368
1369 /* We don't do permission checks on the internal objects.
1370 * Permissions are determined by the "owning" object. */
1371 if (is_reiserfs_priv_object (inode))
1372 return 0;
1373
1374 if (current->fsuid == inode->i_uid) {
1375 mode >>= 6;
1376 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
1377 } else if (reiserfs_posixacl(inode->i_sb) &&
1378 get_inode_sd_version (inode) != STAT_DATA_V1) {
1379 struct posix_acl *acl;
1380
1381 /* ACL can't contain additional permissions if
1382 the ACL_MASK entry is 0 */
1383 if (!(mode & S_IRWXG))
1384 goto check_groups;
1385
1386 if (need_lock) {
1387 reiserfs_read_lock_xattr_i (inode);
1388 reiserfs_read_lock_xattrs (inode->i_sb);
1389 }
1390 acl = reiserfs_get_acl (inode, ACL_TYPE_ACCESS);
1391 if (need_lock) {
1392 reiserfs_read_unlock_xattrs (inode->i_sb);
1393 reiserfs_read_unlock_xattr_i (inode);
1394 }
1395 if (IS_ERR (acl)) {
1396 if (PTR_ERR (acl) == -ENODATA)
1397 goto check_groups;
1398 return PTR_ERR (acl);
1399 }
1400
1401 if (acl) {
1402 int err = posix_acl_permission (inode, acl, mask);
1403 posix_acl_release (acl);
1404 if (err == -EACCES) {
1405 goto check_capabilities;
1406 }
1407 return err;
1408 } else {
1409 goto check_groups;
1410 }
1411 #endif
1412 } else {
1413 check_groups:
1414 if (in_group_p(inode->i_gid))
1415 mode >>= 3;
1416 }
1417
1418 /*
1419 * If the DACs are ok we don't need any capability check.
1420 */
1421 if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask))
1422 return 0;
1423
1424 check_capabilities:
1425 /*
1426 * Read/write DACs are always overridable.
1427 * Executable DACs are overridable if at least one exec bit is set.
1428 */
1429 if (!(mask & MAY_EXEC) ||
1430 (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
1431 if (capable(CAP_DAC_OVERRIDE))
1432 return 0;
1433
1434 /*
1435 * Searching includes executable on directories, else just read.
1436 */
1437 if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE)))
1438 if (capable(CAP_DAC_READ_SEARCH))
1439 return 0;
1440
1441 return -EACCES;
1442 }
1443
1444 int
1445 reiserfs_permission (struct inode *inode, int mask, struct nameidata *nd)
1446 {
1447 return __reiserfs_permission (inode, mask, nd, 1);
1448 }
1449
1450 int
1451 reiserfs_permission_locked (struct inode *inode, int mask, struct nameidata *nd)
1452 {
1453 return __reiserfs_permission (inode, mask, nd, 0);
1454 }
1455
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