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sysfs: Remove support for tagged directories with untagged members (again)
[linux-btrfs-devel.git] / fs / jfs / xattr.c
blob26683e15b3ac9f23991110687023e0f6e3bb0db0
1 /*
2 * Copyright (C) International Business Machines Corp., 2000-2004
3 * Copyright (C) Christoph Hellwig, 2002
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <linux/capability.h>
21 #include <linux/fs.h>
22 #include <linux/xattr.h>
23 #include <linux/posix_acl_xattr.h>
24 #include <linux/slab.h>
25 #include <linux/quotaops.h>
26 #include <linux/security.h>
27 #include "jfs_incore.h"
28 #include "jfs_superblock.h"
29 #include "jfs_dmap.h"
30 #include "jfs_debug.h"
31 #include "jfs_dinode.h"
32 #include "jfs_extent.h"
33 #include "jfs_metapage.h"
34 #include "jfs_xattr.h"
35 #include "jfs_acl.h"
36
37 /*
38 * jfs_xattr.c: extended attribute service
39 *
40 * Overall design --
41 *
42 * Format:
43 *
44 * Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
45 * value) and a variable (0 or more) number of extended attribute
46 * entries. Each extended attribute entry (jfs_ea) is a <name,value> double
47 * where <name> is constructed from a null-terminated ascii string
48 * (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
49 * (1 ... 65535 bytes). The in-memory format is
50 *
51 * 0 1 2 4 4 + namelen + 1
52 * +-------+--------+--------+----------------+-------------------+
53 * | Flags | Name | Value | Name String \0 | Data . . . . |
54 * | | Length | Length | | |
55 * +-------+--------+--------+----------------+-------------------+
56 *
57 * A jfs_ea_list then is structured as
58 *
59 * 0 4 4 + EA_SIZE(ea1)
60 * +------------+-------------------+--------------------+-----
61 * | Overall EA | First FEA Element | Second FEA Element | .....
62 * | List Size | | |
63 * +------------+-------------------+--------------------+-----
64 *
65 * On-disk:
66 *
67 * FEALISTs are stored on disk using blocks allocated by dbAlloc() and
68 * written directly. An EA list may be in-lined in the inode if there is
69 * sufficient room available.
70 */
71
72 struct ea_buffer {
73 int flag; /* Indicates what storage xattr points to */
74 int max_size; /* largest xattr that fits in current buffer */
75 dxd_t new_ea; /* dxd to replace ea when modifying xattr */
76 struct metapage *mp; /* metapage containing ea list */
77 struct jfs_ea_list *xattr; /* buffer containing ea list */
78 };
79
80 /*
81 * ea_buffer.flag values
82 */
83 #define EA_INLINE 0x0001
84 #define EA_EXTENT 0x0002
85 #define EA_NEW 0x0004
86 #define EA_MALLOC 0x0008
87
88
89 static int is_known_namespace(const char *name)
90 {
91 if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
92 strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
93 strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
94 strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
95 return false;
96
97 return true;
98 }
99
100 /*
101 * These three routines are used to recognize on-disk extended attributes
102 * that are in a recognized namespace. If the attribute is not recognized,
103 * "os2." is prepended to the name
104 */
105 static int is_os2_xattr(struct jfs_ea *ea)
106 {
107 return !is_known_namespace(ea->name);
108 }
109
110 static inline int name_size(struct jfs_ea *ea)
111 {
112 if (is_os2_xattr(ea))
113 return ea->namelen + XATTR_OS2_PREFIX_LEN;
114 else
115 return ea->namelen;
116 }
117
118 static inline int copy_name(char *buffer, struct jfs_ea *ea)
119 {
120 int len = ea->namelen;
121
122 if (is_os2_xattr(ea)) {
123 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
124 buffer += XATTR_OS2_PREFIX_LEN;
125 len += XATTR_OS2_PREFIX_LEN;
126 }
127 memcpy(buffer, ea->name, ea->namelen);
128 buffer[ea->namelen] = 0;
129
130 return len;
131 }
132
133 /* Forward references */
134 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
135
136 /*
137 * NAME: ea_write_inline
138 *
139 * FUNCTION: Attempt to write an EA inline if area is available
140 *
141 * PRE CONDITIONS:
142 * Already verified that the specified EA is small enough to fit inline
143 *
144 * PARAMETERS:
145 * ip - Inode pointer
146 * ealist - EA list pointer
147 * size - size of ealist in bytes
148 * ea - dxd_t structure to be filled in with necessary EA information
149 * if we successfully copy the EA inline
150 *
151 * NOTES:
152 * Checks if the inode's inline area is available. If so, copies EA inline
153 * and sets <ea> fields appropriately. Otherwise, returns failure, EA will
154 * have to be put into an extent.
155 *
156 * RETURNS: 0 for successful copy to inline area; -1 if area not available
157 */
158 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
159 int size, dxd_t * ea)
160 {
161 struct jfs_inode_info *ji = JFS_IP(ip);
162
163 /*
164 * Make sure we have an EA -- the NULL EA list is valid, but you
165 * can't copy it!
166 */
167 if (ealist && size > sizeof (struct jfs_ea_list)) {
168 assert(size <= sizeof (ji->i_inline_ea));
169
170 /*
171 * See if the space is available or if it is already being
172 * used for an inline EA.
173 */
174 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
175 return -EPERM;
176
177 DXDsize(ea, size);
178 DXDlength(ea, 0);
179 DXDaddress(ea, 0);
180 memcpy(ji->i_inline_ea, ealist, size);
181 ea->flag = DXD_INLINE;
182 ji->mode2 &= ~INLINEEA;
183 } else {
184 ea->flag = 0;
185 DXDsize(ea, 0);
186 DXDlength(ea, 0);
187 DXDaddress(ea, 0);
188
189 /* Free up INLINE area */
190 if (ji->ea.flag & DXD_INLINE)
191 ji->mode2 |= INLINEEA;
192 }
193
194 return 0;
195 }
196
197 /*
198 * NAME: ea_write
199 *
200 * FUNCTION: Write an EA for an inode
201 *
202 * PRE CONDITIONS: EA has been verified
203 *
204 * PARAMETERS:
205 * ip - Inode pointer
206 * ealist - EA list pointer
207 * size - size of ealist in bytes
208 * ea - dxd_t structure to be filled in appropriately with where the
209 * EA was copied
210 *
211 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
212 * extent and synchronously writes it to those blocks.
213 *
214 * RETURNS: 0 for success; Anything else indicates failure
215 */
216 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
217 dxd_t * ea)
218 {
219 struct super_block *sb = ip->i_sb;
220 struct jfs_inode_info *ji = JFS_IP(ip);
221 struct jfs_sb_info *sbi = JFS_SBI(sb);
222 int nblocks;
223 s64 blkno;
224 int rc = 0, i;
225 char *cp;
226 s32 nbytes, nb;
227 s32 bytes_to_write;
228 struct metapage *mp;
229
230 /*
231 * Quick check to see if this is an in-linable EA. Short EAs
232 * and empty EAs are all in-linable, provided the space exists.
233 */
234 if (!ealist || size <= sizeof (ji->i_inline_ea)) {
235 if (!ea_write_inline(ip, ealist, size, ea))
236 return 0;
237 }
238
239 /* figure out how many blocks we need */
240 nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
241
242 /* Allocate new blocks to quota. */
243 rc = dquot_alloc_block(ip, nblocks);
244 if (rc)
245 return rc;
246
247 rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
248 if (rc) {
249 /*Rollback quota allocation. */
250 dquot_free_block(ip, nblocks);
251 return rc;
252 }
253
254 /*
255 * Now have nblocks worth of storage to stuff into the FEALIST.
256 * loop over the FEALIST copying data into the buffer one page at
257 * a time.
258 */
259 cp = (char *) ealist;
260 nbytes = size;
261 for (i = 0; i < nblocks; i += sbi->nbperpage) {
262 /*
263 * Determine how many bytes for this request, and round up to
264 * the nearest aggregate block size
265 */
266 nb = min(PSIZE, nbytes);
267 bytes_to_write =
268 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
269 << sb->s_blocksize_bits;
270
271 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
272 rc = -EIO;
273 goto failed;
274 }
275
276 memcpy(mp->data, cp, nb);
277
278 /*
279 * We really need a way to propagate errors for
280 * forced writes like this one. --hch
281 *
282 * (__write_metapage => release_metapage => flush_metapage)
283 */
284 #ifdef _JFS_FIXME
285 if ((rc = flush_metapage(mp))) {
286 /*
287 * the write failed -- this means that the buffer
288 * is still assigned and the blocks are not being
289 * used. this seems like the best error recovery
290 * we can get ...
291 */
292 goto failed;
293 }
294 #else
295 flush_metapage(mp);
296 #endif
297
298 cp += PSIZE;
299 nbytes -= nb;
300 }
301
302 ea->flag = DXD_EXTENT;
303 DXDsize(ea, le32_to_cpu(ealist->size));
304 DXDlength(ea, nblocks);
305 DXDaddress(ea, blkno);
306
307 /* Free up INLINE area */
308 if (ji->ea.flag & DXD_INLINE)
309 ji->mode2 |= INLINEEA;
310
311 return 0;
312
313 failed:
314 /* Rollback quota allocation. */
315 dquot_free_block(ip, nblocks);
316
317 dbFree(ip, blkno, nblocks);
318 return rc;
319 }
320
321 /*
322 * NAME: ea_read_inline
323 *
324 * FUNCTION: Read an inlined EA into user's buffer
325 *
326 * PARAMETERS:
327 * ip - Inode pointer
328 * ealist - Pointer to buffer to fill in with EA
329 *
330 * RETURNS: 0
331 */
332 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
333 {
334 struct jfs_inode_info *ji = JFS_IP(ip);
335 int ea_size = sizeDXD(&ji->ea);
336
337 if (ea_size == 0) {
338 ealist->size = 0;
339 return 0;
340 }
341
342 /* Sanity Check */
343 if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
344 return -EIO;
345 if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
346 != ea_size)
347 return -EIO;
348
349 memcpy(ealist, ji->i_inline_ea, ea_size);
350 return 0;
351 }
352
353 /*
354 * NAME: ea_read
355 *
356 * FUNCTION: copy EA data into user's buffer
357 *
358 * PARAMETERS:
359 * ip - Inode pointer
360 * ealist - Pointer to buffer to fill in with EA
361 *
362 * NOTES: If EA is inline calls ea_read_inline() to copy EA.
363 *
364 * RETURNS: 0 for success; other indicates failure
365 */
366 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
367 {
368 struct super_block *sb = ip->i_sb;
369 struct jfs_inode_info *ji = JFS_IP(ip);
370 struct jfs_sb_info *sbi = JFS_SBI(sb);
371 int nblocks;
372 s64 blkno;
373 char *cp = (char *) ealist;
374 int i;
375 int nbytes, nb;
376 s32 bytes_to_read;
377 struct metapage *mp;
378
379 /* quick check for in-line EA */
380 if (ji->ea.flag & DXD_INLINE)
381 return ea_read_inline(ip, ealist);
382
383 nbytes = sizeDXD(&ji->ea);
384 if (!nbytes) {
385 jfs_error(sb, "ea_read: nbytes is 0");
386 return -EIO;
387 }
388
389 /*
390 * Figure out how many blocks were allocated when this EA list was
391 * originally written to disk.
392 */
393 nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
394 blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
395
396 /*
397 * I have found the disk blocks which were originally used to store
398 * the FEALIST. now i loop over each contiguous block copying the
399 * data into the buffer.
400 */
401 for (i = 0; i < nblocks; i += sbi->nbperpage) {
402 /*
403 * Determine how many bytes for this request, and round up to
404 * the nearest aggregate block size
405 */
406 nb = min(PSIZE, nbytes);
407 bytes_to_read =
408 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
409 << sb->s_blocksize_bits;
410
411 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
412 return -EIO;
413
414 memcpy(cp, mp->data, nb);
415 release_metapage(mp);
416
417 cp += PSIZE;
418 nbytes -= nb;
419 }
420
421 return 0;
422 }
423
424 /*
425 * NAME: ea_get
426 *
427 * FUNCTION: Returns buffer containing existing extended attributes.
428 * The size of the buffer will be the larger of the existing
429 * attributes size, or min_size.
430 *
431 * The buffer, which may be inlined in the inode or in the
432 * page cache must be release by calling ea_release or ea_put
433 *
434 * PARAMETERS:
435 * inode - Inode pointer
436 * ea_buf - Structure to be populated with ealist and its metadata
437 * min_size- minimum size of buffer to be returned
438 *
439 * RETURNS: 0 for success; Other indicates failure
440 */
441 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
442 {
443 struct jfs_inode_info *ji = JFS_IP(inode);
444 struct super_block *sb = inode->i_sb;
445 int size;
446 int ea_size = sizeDXD(&ji->ea);
447 int blocks_needed, current_blocks;
448 s64 blkno;
449 int rc;
450 int quota_allocation = 0;
451
452 /* When fsck.jfs clears a bad ea, it doesn't clear the size */
453 if (ji->ea.flag == 0)
454 ea_size = 0;
455
456 if (ea_size == 0) {
457 if (min_size == 0) {
458 ea_buf->flag = 0;
459 ea_buf->max_size = 0;
460 ea_buf->xattr = NULL;
461 return 0;
462 }
463 if ((min_size <= sizeof (ji->i_inline_ea)) &&
464 (ji->mode2 & INLINEEA)) {
465 ea_buf->flag = EA_INLINE | EA_NEW;
466 ea_buf->max_size = sizeof (ji->i_inline_ea);
467 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
468 DXDlength(&ea_buf->new_ea, 0);
469 DXDaddress(&ea_buf->new_ea, 0);
470 ea_buf->new_ea.flag = DXD_INLINE;
471 DXDsize(&ea_buf->new_ea, min_size);
472 return 0;
473 }
474 current_blocks = 0;
475 } else if (ji->ea.flag & DXD_INLINE) {
476 if (min_size <= sizeof (ji->i_inline_ea)) {
477 ea_buf->flag = EA_INLINE;
478 ea_buf->max_size = sizeof (ji->i_inline_ea);
479 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
480 goto size_check;
481 }
482 current_blocks = 0;
483 } else {
484 if (!(ji->ea.flag & DXD_EXTENT)) {
485 jfs_error(sb, "ea_get: invalid ea.flag)");
486 return -EIO;
487 }
488 current_blocks = (ea_size + sb->s_blocksize - 1) >>
489 sb->s_blocksize_bits;
490 }
491 size = max(min_size, ea_size);
492
493 if (size > PSIZE) {
494 /*
495 * To keep the rest of the code simple. Allocate a
496 * contiguous buffer to work with
497 */
498 ea_buf->xattr = kmalloc(size, GFP_KERNEL);
499 if (ea_buf->xattr == NULL)
500 return -ENOMEM;
501
502 ea_buf->flag = EA_MALLOC;
503 ea_buf->max_size = (size + sb->s_blocksize - 1) &
504 ~(sb->s_blocksize - 1);
505
506 if (ea_size == 0)
507 return 0;
508
509 if ((rc = ea_read(inode, ea_buf->xattr))) {
510 kfree(ea_buf->xattr);
511 ea_buf->xattr = NULL;
512 return rc;
513 }
514 goto size_check;
515 }
516 blocks_needed = (min_size + sb->s_blocksize - 1) >>
517 sb->s_blocksize_bits;
518
519 if (blocks_needed > current_blocks) {
520 /* Allocate new blocks to quota. */
521 rc = dquot_alloc_block(inode, blocks_needed);
522 if (rc)
523 return -EDQUOT;
524
525 quota_allocation = blocks_needed;
526
527 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
528 &blkno);
529 if (rc)
530 goto clean_up;
531
532 DXDlength(&ea_buf->new_ea, blocks_needed);
533 DXDaddress(&ea_buf->new_ea, blkno);
534 ea_buf->new_ea.flag = DXD_EXTENT;
535 DXDsize(&ea_buf->new_ea, min_size);
536
537 ea_buf->flag = EA_EXTENT | EA_NEW;
538
539 ea_buf->mp = get_metapage(inode, blkno,
540 blocks_needed << sb->s_blocksize_bits,
541 1);
542 if (ea_buf->mp == NULL) {
543 dbFree(inode, blkno, (s64) blocks_needed);
544 rc = -EIO;
545 goto clean_up;
546 }
547 ea_buf->xattr = ea_buf->mp->data;
548 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
549 ~(sb->s_blocksize - 1);
550 if (ea_size == 0)
551 return 0;
552 if ((rc = ea_read(inode, ea_buf->xattr))) {
553 discard_metapage(ea_buf->mp);
554 dbFree(inode, blkno, (s64) blocks_needed);
555 goto clean_up;
556 }
557 goto size_check;
558 }
559 ea_buf->flag = EA_EXTENT;
560 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
561 lengthDXD(&ji->ea) << sb->s_blocksize_bits,
562 1);
563 if (ea_buf->mp == NULL) {
564 rc = -EIO;
565 goto clean_up;
566 }
567 ea_buf->xattr = ea_buf->mp->data;
568 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
569 ~(sb->s_blocksize - 1);
570
571 size_check:
572 if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
573 printk(KERN_ERR "ea_get: invalid extended attribute\n");
574 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
575 ea_buf->xattr, ea_size, 1);
576 ea_release(inode, ea_buf);
577 rc = -EIO;
578 goto clean_up;
579 }
580
581 return ea_size;
582
583 clean_up:
584 /* Rollback quota allocation */
585 if (quota_allocation)
586 dquot_free_block(inode, quota_allocation);
587
588 return (rc);
589 }
590
591 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
592 {
593 if (ea_buf->flag & EA_MALLOC)
594 kfree(ea_buf->xattr);
595 else if (ea_buf->flag & EA_EXTENT) {
596 assert(ea_buf->mp);
597 release_metapage(ea_buf->mp);
598
599 if (ea_buf->flag & EA_NEW)
600 dbFree(inode, addressDXD(&ea_buf->new_ea),
601 lengthDXD(&ea_buf->new_ea));
602 }
603 }
604
605 static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
606 int new_size)
607 {
608 struct jfs_inode_info *ji = JFS_IP(inode);
609 unsigned long old_blocks, new_blocks;
610 int rc = 0;
611
612 if (new_size == 0) {
613 ea_release(inode, ea_buf);
614 ea_buf = NULL;
615 } else if (ea_buf->flag & EA_INLINE) {
616 assert(new_size <= sizeof (ji->i_inline_ea));
617 ji->mode2 &= ~INLINEEA;
618 ea_buf->new_ea.flag = DXD_INLINE;
619 DXDsize(&ea_buf->new_ea, new_size);
620 DXDaddress(&ea_buf->new_ea, 0);
621 DXDlength(&ea_buf->new_ea, 0);
622 } else if (ea_buf->flag & EA_MALLOC) {
623 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
624 kfree(ea_buf->xattr);
625 } else if (ea_buf->flag & EA_NEW) {
626 /* We have already allocated a new dxd */
627 flush_metapage(ea_buf->mp);
628 } else {
629 /* ->xattr must point to original ea's metapage */
630 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
631 discard_metapage(ea_buf->mp);
632 }
633 if (rc)
634 return rc;
635
636 old_blocks = new_blocks = 0;
637
638 if (ji->ea.flag & DXD_EXTENT) {
639 invalidate_dxd_metapages(inode, ji->ea);
640 old_blocks = lengthDXD(&ji->ea);
641 }
642
643 if (ea_buf) {
644 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
645 if (ea_buf->new_ea.flag & DXD_EXTENT) {
646 new_blocks = lengthDXD(&ea_buf->new_ea);
647 if (ji->ea.flag & DXD_INLINE)
648 ji->mode2 |= INLINEEA;
649 }
650 ji->ea = ea_buf->new_ea;
651 } else {
652 txEA(tid, inode, &ji->ea, NULL);
653 if (ji->ea.flag & DXD_INLINE)
654 ji->mode2 |= INLINEEA;
655 ji->ea.flag = 0;
656 ji->ea.size = 0;
657 }
658
659 /* If old blocks exist, they must be removed from quota allocation. */
660 if (old_blocks)
661 dquot_free_block(inode, old_blocks);
662
663 inode->i_ctime = CURRENT_TIME;
664
665 return 0;
666 }
667
668 /*
669 * can_set_system_xattr
670 *
671 * This code is specific to the system.* namespace. It contains policy
672 * which doesn't belong in the main xattr codepath.
673 */
674 static int can_set_system_xattr(struct inode *inode, const char *name,
675 const void *value, size_t value_len)
676 {
677 #ifdef CONFIG_JFS_POSIX_ACL
678 struct posix_acl *acl;
679 int rc;
680
681 if (!inode_owner_or_capable(inode))
682 return -EPERM;
683
684 /*
685 * POSIX_ACL_XATTR_ACCESS is tied to i_mode
686 */
687 if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0) {
688 acl = posix_acl_from_xattr(value, value_len);
689 if (IS_ERR(acl)) {
690 rc = PTR_ERR(acl);
691 printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
692 rc);
693 return rc;
694 }
695 if (acl) {
696 rc = posix_acl_equiv_mode(acl, &inode->i_mode);
697 posix_acl_release(acl);
698 if (rc < 0) {
699 printk(KERN_ERR
700 "posix_acl_equiv_mode returned %d\n",
701 rc);
702 return rc;
703 }
704 mark_inode_dirty(inode);
705 }
706 /*
707 * We're changing the ACL. Get rid of the cached one
708 */
709 forget_cached_acl(inode, ACL_TYPE_ACCESS);
710
711 return 0;
712 } else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0) {
713 acl = posix_acl_from_xattr(value, value_len);
714 if (IS_ERR(acl)) {
715 rc = PTR_ERR(acl);
716 printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
717 rc);
718 return rc;
719 }
720 posix_acl_release(acl);
721
722 /*
723 * We're changing the default ACL. Get rid of the cached one
724 */
725 forget_cached_acl(inode, ACL_TYPE_DEFAULT);
726
727 return 0;
728 }
729 #endif /* CONFIG_JFS_POSIX_ACL */
730 return -EOPNOTSUPP;
731 }
732
733 /*
734 * Most of the permission checking is done by xattr_permission in the vfs.
735 * The local file system is responsible for handling the system.* namespace.
736 * We also need to verify that this is a namespace that we recognize.
737 */
738 static int can_set_xattr(struct inode *inode, const char *name,
739 const void *value, size_t value_len)
740 {
741 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
742 return can_set_system_xattr(inode, name, value, value_len);
743
744 if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
745 /*
746 * This makes sure that we aren't trying to set an
747 * attribute in a different namespace by prefixing it
748 * with "os2."
749 */
750 if (is_known_namespace(name + XATTR_OS2_PREFIX_LEN))
751 return -EOPNOTSUPP;
752 return 0;
753 }
754
755 /*
756 * Don't allow setting an attribute in an unknown namespace.
757 */
758 if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
759 strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
760 strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
761 return -EOPNOTSUPP;
762
763 return 0;
764 }
765
766 int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
767 const void *value, size_t value_len, int flags)
768 {
769 struct jfs_ea_list *ealist;
770 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
771 struct ea_buffer ea_buf;
772 int old_ea_size = 0;
773 int xattr_size;
774 int new_size;
775 int namelen = strlen(name);
776 char *os2name = NULL;
777 int found = 0;
778 int rc;
779 int length;
780
781 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
782 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
783 GFP_KERNEL);
784 if (!os2name)
785 return -ENOMEM;
786 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
787 name = os2name;
788 namelen -= XATTR_OS2_PREFIX_LEN;
789 }
790
791 down_write(&JFS_IP(inode)->xattr_sem);
792
793 xattr_size = ea_get(inode, &ea_buf, 0);
794 if (xattr_size < 0) {
795 rc = xattr_size;
796 goto out;
797 }
798
799 again:
800 ealist = (struct jfs_ea_list *) ea_buf.xattr;
801 new_size = sizeof (struct jfs_ea_list);
802
803 if (xattr_size) {
804 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
805 ea = NEXT_EA(ea)) {
806 if ((namelen == ea->namelen) &&
807 (memcmp(name, ea->name, namelen) == 0)) {
808 found = 1;
809 if (flags & XATTR_CREATE) {
810 rc = -EEXIST;
811 goto release;
812 }
813 old_ea = ea;
814 old_ea_size = EA_SIZE(ea);
815 next_ea = NEXT_EA(ea);
816 } else
817 new_size += EA_SIZE(ea);
818 }
819 }
820
821 if (!found) {
822 if (flags & XATTR_REPLACE) {
823 rc = -ENODATA;
824 goto release;
825 }
826 if (value == NULL) {
827 rc = 0;
828 goto release;
829 }
830 }
831 if (value)
832 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
833
834 if (new_size > ea_buf.max_size) {
835 /*
836 * We need to allocate more space for merged ea list.
837 * We should only have loop to again: once.
838 */
839 ea_release(inode, &ea_buf);
840 xattr_size = ea_get(inode, &ea_buf, new_size);
841 if (xattr_size < 0) {
842 rc = xattr_size;
843 goto out;
844 }
845 goto again;
846 }
847
848 /* Remove old ea of the same name */
849 if (found) {
850 /* number of bytes following target EA */
851 length = (char *) END_EALIST(ealist) - (char *) next_ea;
852 if (length > 0)
853 memmove(old_ea, next_ea, length);
854 xattr_size -= old_ea_size;
855 }
856
857 /* Add new entry to the end */
858 if (value) {
859 if (xattr_size == 0)
860 /* Completely new ea list */
861 xattr_size = sizeof (struct jfs_ea_list);
862
863 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
864 ea->flag = 0;
865 ea->namelen = namelen;
866 ea->valuelen = (cpu_to_le16(value_len));
867 memcpy(ea->name, name, namelen);
868 ea->name[namelen] = 0;
869 if (value_len)
870 memcpy(&ea->name[namelen + 1], value, value_len);
871 xattr_size += EA_SIZE(ea);
872 }
873
874 /* DEBUG - If we did this right, these number match */
875 if (xattr_size != new_size) {
876 printk(KERN_ERR
877 "jfs_xsetattr: xattr_size = %d, new_size = %d\n",
878 xattr_size, new_size);
879
880 rc = -EINVAL;
881 goto release;
882 }
883
884 /*
885 * If we're left with an empty list, there's no ea
886 */
887 if (new_size == sizeof (struct jfs_ea_list))
888 new_size = 0;
889
890 ealist->size = cpu_to_le32(new_size);
891
892 rc = ea_put(tid, inode, &ea_buf, new_size);
893
894 goto out;
895 release:
896 ea_release(inode, &ea_buf);
897 out:
898 up_write(&JFS_IP(inode)->xattr_sem);
899
900 kfree(os2name);
901
902 return rc;
903 }
904
905 int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
906 size_t value_len, int flags)
907 {
908 struct inode *inode = dentry->d_inode;
909 struct jfs_inode_info *ji = JFS_IP(inode);
910 int rc;
911 tid_t tid;
912
913 if ((rc = can_set_xattr(inode, name, value, value_len)))
914 return rc;
915
916 if (value == NULL) { /* empty EA, do not remove */
917 value = "";
918 value_len = 0;
919 }
920
921 tid = txBegin(inode->i_sb, 0);
922 mutex_lock(&ji->commit_mutex);
923 rc = __jfs_setxattr(tid, dentry->d_inode, name, value, value_len,
924 flags);
925 if (!rc)
926 rc = txCommit(tid, 1, &inode, 0);
927 txEnd(tid);
928 mutex_unlock(&ji->commit_mutex);
929
930 return rc;
931 }
932
933 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
934 size_t buf_size)
935 {
936 struct jfs_ea_list *ealist;
937 struct jfs_ea *ea;
938 struct ea_buffer ea_buf;
939 int xattr_size;
940 ssize_t size;
941 int namelen = strlen(name);
942 char *value;
943
944 down_read(&JFS_IP(inode)->xattr_sem);
945
946 xattr_size = ea_get(inode, &ea_buf, 0);
947
948 if (xattr_size < 0) {
949 size = xattr_size;
950 goto out;
951 }
952
953 if (xattr_size == 0)
954 goto not_found;
955
956 ealist = (struct jfs_ea_list *) ea_buf.xattr;
957
958 /* Find the named attribute */
959 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
960 if ((namelen == ea->namelen) &&
961 memcmp(name, ea->name, namelen) == 0) {
962 /* Found it */
963 size = le16_to_cpu(ea->valuelen);
964 if (!data)
965 goto release;
966 else if (size > buf_size) {
967 size = -ERANGE;
968 goto release;
969 }
970 value = ((char *) &ea->name) + ea->namelen + 1;
971 memcpy(data, value, size);
972 goto release;
973 }
974 not_found:
975 size = -ENODATA;
976 release:
977 ea_release(inode, &ea_buf);
978 out:
979 up_read(&JFS_IP(inode)->xattr_sem);
980
981 return size;
982 }
983
984 ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
985 size_t buf_size)
986 {
987 int err;
988
989 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
990 /*
991 * skip past "os2." prefix
992 */
993 name += XATTR_OS2_PREFIX_LEN;
994 /*
995 * Don't allow retrieving properly prefixed attributes
996 * by prepending them with "os2."
997 */
998 if (is_known_namespace(name))
999 return -EOPNOTSUPP;
1000 }
1001
1002 err = __jfs_getxattr(dentry->d_inode, name, data, buf_size);
1003
1004 return err;
1005 }
1006
1007 /*
1008 * No special permissions are needed to list attributes except for trusted.*
1009 */
1010 static inline int can_list(struct jfs_ea *ea)
1011 {
1012 return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
1013 XATTR_TRUSTED_PREFIX_LEN) ||
1014 capable(CAP_SYS_ADMIN));
1015 }
1016
1017 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
1018 {
1019 struct inode *inode = dentry->d_inode;
1020 char *buffer;
1021 ssize_t size = 0;
1022 int xattr_size;
1023 struct jfs_ea_list *ealist;
1024 struct jfs_ea *ea;
1025 struct ea_buffer ea_buf;
1026
1027 down_read(&JFS_IP(inode)->xattr_sem);
1028
1029 xattr_size = ea_get(inode, &ea_buf, 0);
1030 if (xattr_size < 0) {
1031 size = xattr_size;
1032 goto out;
1033 }
1034
1035 if (xattr_size == 0)
1036 goto release;
1037
1038 ealist = (struct jfs_ea_list *) ea_buf.xattr;
1039
1040 /* compute required size of list */
1041 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1042 if (can_list(ea))
1043 size += name_size(ea) + 1;
1044 }
1045
1046 if (!data)
1047 goto release;
1048
1049 if (size > buf_size) {
1050 size = -ERANGE;
1051 goto release;
1052 }
1053
1054 /* Copy attribute names to buffer */
1055 buffer = data;
1056 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1057 if (can_list(ea)) {
1058 int namelen = copy_name(buffer, ea);
1059 buffer += namelen + 1;
1060 }
1061 }
1062
1063 release:
1064 ea_release(inode, &ea_buf);
1065 out:
1066 up_read(&JFS_IP(inode)->xattr_sem);
1067 return size;
1068 }
1069
1070 int jfs_removexattr(struct dentry *dentry, const char *name)
1071 {
1072 struct inode *inode = dentry->d_inode;
1073 struct jfs_inode_info *ji = JFS_IP(inode);
1074 int rc;
1075 tid_t tid;
1076
1077 if ((rc = can_set_xattr(inode, name, NULL, 0)))
1078 return rc;
1079
1080 tid = txBegin(inode->i_sb, 0);
1081 mutex_lock(&ji->commit_mutex);
1082 rc = __jfs_setxattr(tid, dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
1083 if (!rc)
1084 rc = txCommit(tid, 1, &inode, 0);
1085 txEnd(tid);
1086 mutex_unlock(&ji->commit_mutex);
1087
1088 return rc;
1089 }
1090
1091 #ifdef CONFIG_JFS_SECURITY
1092 int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
1093 void *fs_info)
1094 {
1095 const struct xattr *xattr;
1096 tid_t *tid = fs_info;
1097 char *name;
1098 int err = 0;
1099
1100 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
1101 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
1102 strlen(xattr->name) + 1, GFP_NOFS);
1103 if (!name) {
1104 err = -ENOMEM;
1105 break;
1106 }
1107 strcpy(name, XATTR_SECURITY_PREFIX);
1108 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
1109
1110 err = __jfs_setxattr(*tid, inode, name,
1111 xattr->value, xattr->value_len, 0);
1112 kfree(name);
1113 if (err < 0)
1114 break;
1115 }
1116 return err;
1117 }
1118
1119 int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
1120 const struct qstr *qstr)
1121 {
1122 return security_inode_init_security(inode, dir, qstr,
1123 &jfs_initxattrs, &tid);
1124 }
1125 #endif
Linux Btrfs Development