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Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
[linux-2.6/kmemtrace.git] / fs / jfs / xattr.c
blob9b7f2cdaae0a6655538066e104bff5e10bbcab70
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/quotaops.h>
25 #include <linux/security.h>
26 #include "jfs_incore.h"
27 #include "jfs_superblock.h"
28 #include "jfs_dmap.h"
29 #include "jfs_debug.h"
30 #include "jfs_dinode.h"
31 #include "jfs_extent.h"
32 #include "jfs_metapage.h"
33 #include "jfs_xattr.h"
34 #include "jfs_acl.h"
35
36 /*
37 * jfs_xattr.c: extended attribute service
38 *
39 * Overall design --
40 *
41 * Format:
42 *
43 * Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
44 * value) and a variable (0 or more) number of extended attribute
45 * entries. Each extended attribute entry (jfs_ea) is a <name,value> double
46 * where <name> is constructed from a null-terminated ascii string
47 * (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
48 * (1 ... 65535 bytes). The in-memory format is
49 *
50 * 0 1 2 4 4 + namelen + 1
51 * +-------+--------+--------+----------------+-------------------+
52 * | Flags | Name | Value | Name String \0 | Data . . . . |
53 * | | Length | Length | | |
54 * +-------+--------+--------+----------------+-------------------+
55 *
56 * A jfs_ea_list then is structured as
57 *
58 * 0 4 4 + EA_SIZE(ea1)
59 * +------------+-------------------+--------------------+-----
60 * | Overall EA | First FEA Element | Second FEA Element | .....
61 * | List Size | | |
62 * +------------+-------------------+--------------------+-----
63 *
64 * On-disk:
65 *
66 * FEALISTs are stored on disk using blocks allocated by dbAlloc() and
67 * written directly. An EA list may be in-lined in the inode if there is
68 * sufficient room available.
69 */
70
71 struct ea_buffer {
72 int flag; /* Indicates what storage xattr points to */
73 int max_size; /* largest xattr that fits in current buffer */
74 dxd_t new_ea; /* dxd to replace ea when modifying xattr */
75 struct metapage *mp; /* metapage containing ea list */
76 struct jfs_ea_list *xattr; /* buffer containing ea list */
77 };
78
79 /*
80 * ea_buffer.flag values
81 */
82 #define EA_INLINE 0x0001
83 #define EA_EXTENT 0x0002
84 #define EA_NEW 0x0004
85 #define EA_MALLOC 0x0008
86
87
88 /*
89 * These three routines are used to recognize on-disk extended attributes
90 * that are in a recognized namespace. If the attribute is not recognized,
91 * "os2." is prepended to the name
92 */
93 static inline int is_os2_xattr(struct jfs_ea *ea)
94 {
95 /*
96 * Check for "system."
97 */
98 if ((ea->namelen >= XATTR_SYSTEM_PREFIX_LEN) &&
99 !strncmp(ea->name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
100 return false;
101 /*
102 * Check for "user."
103 */
104 if ((ea->namelen >= XATTR_USER_PREFIX_LEN) &&
105 !strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
106 return false;
107 /*
108 * Check for "security."
109 */
110 if ((ea->namelen >= XATTR_SECURITY_PREFIX_LEN) &&
111 !strncmp(ea->name, XATTR_SECURITY_PREFIX,
112 XATTR_SECURITY_PREFIX_LEN))
113 return false;
114 /*
115 * Check for "trusted."
116 */
117 if ((ea->namelen >= XATTR_TRUSTED_PREFIX_LEN) &&
118 !strncmp(ea->name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
119 return false;
120 /*
121 * Add any other valid namespace prefixes here
122 */
123
124 /*
125 * We assume it's OS/2's flat namespace
126 */
127 return true;
128 }
129
130 static inline int name_size(struct jfs_ea *ea)
131 {
132 if (is_os2_xattr(ea))
133 return ea->namelen + XATTR_OS2_PREFIX_LEN;
134 else
135 return ea->namelen;
136 }
137
138 static inline int copy_name(char *buffer, struct jfs_ea *ea)
139 {
140 int len = ea->namelen;
141
142 if (is_os2_xattr(ea)) {
143 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
144 buffer += XATTR_OS2_PREFIX_LEN;
145 len += XATTR_OS2_PREFIX_LEN;
146 }
147 memcpy(buffer, ea->name, ea->namelen);
148 buffer[ea->namelen] = 0;
149
150 return len;
151 }
152
153 /* Forward references */
154 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
155
156 /*
157 * NAME: ea_write_inline
158 *
159 * FUNCTION: Attempt to write an EA inline if area is available
160 *
161 * PRE CONDITIONS:
162 * Already verified that the specified EA is small enough to fit inline
163 *
164 * PARAMETERS:
165 * ip - Inode pointer
166 * ealist - EA list pointer
167 * size - size of ealist in bytes
168 * ea - dxd_t structure to be filled in with necessary EA information
169 * if we successfully copy the EA inline
170 *
171 * NOTES:
172 * Checks if the inode's inline area is available. If so, copies EA inline
173 * and sets <ea> fields appropriately. Otherwise, returns failure, EA will
174 * have to be put into an extent.
175 *
176 * RETURNS: 0 for successful copy to inline area; -1 if area not available
177 */
178 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
179 int size, dxd_t * ea)
180 {
181 struct jfs_inode_info *ji = JFS_IP(ip);
182
183 /*
184 * Make sure we have an EA -- the NULL EA list is valid, but you
185 * can't copy it!
186 */
187 if (ealist && size > sizeof (struct jfs_ea_list)) {
188 assert(size <= sizeof (ji->i_inline_ea));
189
190 /*
191 * See if the space is available or if it is already being
192 * used for an inline EA.
193 */
194 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
195 return -EPERM;
196
197 DXDsize(ea, size);
198 DXDlength(ea, 0);
199 DXDaddress(ea, 0);
200 memcpy(ji->i_inline_ea, ealist, size);
201 ea->flag = DXD_INLINE;
202 ji->mode2 &= ~INLINEEA;
203 } else {
204 ea->flag = 0;
205 DXDsize(ea, 0);
206 DXDlength(ea, 0);
207 DXDaddress(ea, 0);
208
209 /* Free up INLINE area */
210 if (ji->ea.flag & DXD_INLINE)
211 ji->mode2 |= INLINEEA;
212 }
213
214 return 0;
215 }
216
217 /*
218 * NAME: ea_write
219 *
220 * FUNCTION: Write an EA for an inode
221 *
222 * PRE CONDITIONS: EA has been verified
223 *
224 * PARAMETERS:
225 * ip - Inode pointer
226 * ealist - EA list pointer
227 * size - size of ealist in bytes
228 * ea - dxd_t structure to be filled in appropriately with where the
229 * EA was copied
230 *
231 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
232 * extent and synchronously writes it to those blocks.
233 *
234 * RETURNS: 0 for success; Anything else indicates failure
235 */
236 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
237 dxd_t * ea)
238 {
239 struct super_block *sb = ip->i_sb;
240 struct jfs_inode_info *ji = JFS_IP(ip);
241 struct jfs_sb_info *sbi = JFS_SBI(sb);
242 int nblocks;
243 s64 blkno;
244 int rc = 0, i;
245 char *cp;
246 s32 nbytes, nb;
247 s32 bytes_to_write;
248 struct metapage *mp;
249
250 /*
251 * Quick check to see if this is an in-linable EA. Short EAs
252 * and empty EAs are all in-linable, provided the space exists.
253 */
254 if (!ealist || size <= sizeof (ji->i_inline_ea)) {
255 if (!ea_write_inline(ip, ealist, size, ea))
256 return 0;
257 }
258
259 /* figure out how many blocks we need */
260 nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
261
262 /* Allocate new blocks to quota. */
263 if (DQUOT_ALLOC_BLOCK(ip, nblocks)) {
264 return -EDQUOT;
265 }
266
267 rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
268 if (rc) {
269 /*Rollback quota allocation. */
270 DQUOT_FREE_BLOCK(ip, nblocks);
271 return rc;
272 }
273
274 /*
275 * Now have nblocks worth of storage to stuff into the FEALIST.
276 * loop over the FEALIST copying data into the buffer one page at
277 * a time.
278 */
279 cp = (char *) ealist;
280 nbytes = size;
281 for (i = 0; i < nblocks; i += sbi->nbperpage) {
282 /*
283 * Determine how many bytes for this request, and round up to
284 * the nearest aggregate block size
285 */
286 nb = min(PSIZE, nbytes);
287 bytes_to_write =
288 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
289 << sb->s_blocksize_bits;
290
291 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
292 rc = -EIO;
293 goto failed;
294 }
295
296 memcpy(mp->data, cp, nb);
297
298 /*
299 * We really need a way to propagate errors for
300 * forced writes like this one. --hch
301 *
302 * (__write_metapage => release_metapage => flush_metapage)
303 */
304 #ifdef _JFS_FIXME
305 if ((rc = flush_metapage(mp))) {
306 /*
307 * the write failed -- this means that the buffer
308 * is still assigned and the blocks are not being
309 * used. this seems like the best error recovery
310 * we can get ...
311 */
312 goto failed;
313 }
314 #else
315 flush_metapage(mp);
316 #endif
317
318 cp += PSIZE;
319 nbytes -= nb;
320 }
321
322 ea->flag = DXD_EXTENT;
323 DXDsize(ea, le32_to_cpu(ealist->size));
324 DXDlength(ea, nblocks);
325 DXDaddress(ea, blkno);
326
327 /* Free up INLINE area */
328 if (ji->ea.flag & DXD_INLINE)
329 ji->mode2 |= INLINEEA;
330
331 return 0;
332
333 failed:
334 /* Rollback quota allocation. */
335 DQUOT_FREE_BLOCK(ip, nblocks);
336
337 dbFree(ip, blkno, nblocks);
338 return rc;
339 }
340
341 /*
342 * NAME: ea_read_inline
343 *
344 * FUNCTION: Read an inlined EA into user's buffer
345 *
346 * PARAMETERS:
347 * ip - Inode pointer
348 * ealist - Pointer to buffer to fill in with EA
349 *
350 * RETURNS: 0
351 */
352 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
353 {
354 struct jfs_inode_info *ji = JFS_IP(ip);
355 int ea_size = sizeDXD(&ji->ea);
356
357 if (ea_size == 0) {
358 ealist->size = 0;
359 return 0;
360 }
361
362 /* Sanity Check */
363 if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
364 return -EIO;
365 if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
366 != ea_size)
367 return -EIO;
368
369 memcpy(ealist, ji->i_inline_ea, ea_size);
370 return 0;
371 }
372
373 /*
374 * NAME: ea_read
375 *
376 * FUNCTION: copy EA data into user's buffer
377 *
378 * PARAMETERS:
379 * ip - Inode pointer
380 * ealist - Pointer to buffer to fill in with EA
381 *
382 * NOTES: If EA is inline calls ea_read_inline() to copy EA.
383 *
384 * RETURNS: 0 for success; other indicates failure
385 */
386 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
387 {
388 struct super_block *sb = ip->i_sb;
389 struct jfs_inode_info *ji = JFS_IP(ip);
390 struct jfs_sb_info *sbi = JFS_SBI(sb);
391 int nblocks;
392 s64 blkno;
393 char *cp = (char *) ealist;
394 int i;
395 int nbytes, nb;
396 s32 bytes_to_read;
397 struct metapage *mp;
398
399 /* quick check for in-line EA */
400 if (ji->ea.flag & DXD_INLINE)
401 return ea_read_inline(ip, ealist);
402
403 nbytes = sizeDXD(&ji->ea);
404 if (!nbytes) {
405 jfs_error(sb, "ea_read: nbytes is 0");
406 return -EIO;
407 }
408
409 /*
410 * Figure out how many blocks were allocated when this EA list was
411 * originally written to disk.
412 */
413 nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
414 blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
415
416 /*
417 * I have found the disk blocks which were originally used to store
418 * the FEALIST. now i loop over each contiguous block copying the
419 * data into the buffer.
420 */
421 for (i = 0; i < nblocks; i += sbi->nbperpage) {
422 /*
423 * Determine how many bytes for this request, and round up to
424 * the nearest aggregate block size
425 */
426 nb = min(PSIZE, nbytes);
427 bytes_to_read =
428 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
429 << sb->s_blocksize_bits;
430
431 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
432 return -EIO;
433
434 memcpy(cp, mp->data, nb);
435 release_metapage(mp);
436
437 cp += PSIZE;
438 nbytes -= nb;
439 }
440
441 return 0;
442 }
443
444 /*
445 * NAME: ea_get
446 *
447 * FUNCTION: Returns buffer containing existing extended attributes.
448 * The size of the buffer will be the larger of the existing
449 * attributes size, or min_size.
450 *
451 * The buffer, which may be inlined in the inode or in the
452 * page cache must be release by calling ea_release or ea_put
453 *
454 * PARAMETERS:
455 * inode - Inode pointer
456 * ea_buf - Structure to be populated with ealist and its metadata
457 * min_size- minimum size of buffer to be returned
458 *
459 * RETURNS: 0 for success; Other indicates failure
460 */
461 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
462 {
463 struct jfs_inode_info *ji = JFS_IP(inode);
464 struct super_block *sb = inode->i_sb;
465 int size;
466 int ea_size = sizeDXD(&ji->ea);
467 int blocks_needed, current_blocks;
468 s64 blkno;
469 int rc;
470 int quota_allocation = 0;
471
472 /* When fsck.jfs clears a bad ea, it doesn't clear the size */
473 if (ji->ea.flag == 0)
474 ea_size = 0;
475
476 if (ea_size == 0) {
477 if (min_size == 0) {
478 ea_buf->flag = 0;
479 ea_buf->max_size = 0;
480 ea_buf->xattr = NULL;
481 return 0;
482 }
483 if ((min_size <= sizeof (ji->i_inline_ea)) &&
484 (ji->mode2 & INLINEEA)) {
485 ea_buf->flag = EA_INLINE | EA_NEW;
486 ea_buf->max_size = sizeof (ji->i_inline_ea);
487 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
488 DXDlength(&ea_buf->new_ea, 0);
489 DXDaddress(&ea_buf->new_ea, 0);
490 ea_buf->new_ea.flag = DXD_INLINE;
491 DXDsize(&ea_buf->new_ea, min_size);
492 return 0;
493 }
494 current_blocks = 0;
495 } else if (ji->ea.flag & DXD_INLINE) {
496 if (min_size <= sizeof (ji->i_inline_ea)) {
497 ea_buf->flag = EA_INLINE;
498 ea_buf->max_size = sizeof (ji->i_inline_ea);
499 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
500 goto size_check;
501 }
502 current_blocks = 0;
503 } else {
504 if (!(ji->ea.flag & DXD_EXTENT)) {
505 jfs_error(sb, "ea_get: invalid ea.flag)");
506 return -EIO;
507 }
508 current_blocks = (ea_size + sb->s_blocksize - 1) >>
509 sb->s_blocksize_bits;
510 }
511 size = max(min_size, ea_size);
512
513 if (size > PSIZE) {
514 /*
515 * To keep the rest of the code simple. Allocate a
516 * contiguous buffer to work with
517 */
518 ea_buf->xattr = kmalloc(size, GFP_KERNEL);
519 if (ea_buf->xattr == NULL)
520 return -ENOMEM;
521
522 ea_buf->flag = EA_MALLOC;
523 ea_buf->max_size = (size + sb->s_blocksize - 1) &
524 ~(sb->s_blocksize - 1);
525
526 if (ea_size == 0)
527 return 0;
528
529 if ((rc = ea_read(inode, ea_buf->xattr))) {
530 kfree(ea_buf->xattr);
531 ea_buf->xattr = NULL;
532 return rc;
533 }
534 goto size_check;
535 }
536 blocks_needed = (min_size + sb->s_blocksize - 1) >>
537 sb->s_blocksize_bits;
538
539 if (blocks_needed > current_blocks) {
540 /* Allocate new blocks to quota. */
541 if (DQUOT_ALLOC_BLOCK(inode, blocks_needed))
542 return -EDQUOT;
543
544 quota_allocation = blocks_needed;
545
546 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
547 &blkno);
548 if (rc)
549 goto clean_up;
550
551 DXDlength(&ea_buf->new_ea, blocks_needed);
552 DXDaddress(&ea_buf->new_ea, blkno);
553 ea_buf->new_ea.flag = DXD_EXTENT;
554 DXDsize(&ea_buf->new_ea, min_size);
555
556 ea_buf->flag = EA_EXTENT | EA_NEW;
557
558 ea_buf->mp = get_metapage(inode, blkno,
559 blocks_needed << sb->s_blocksize_bits,
560 1);
561 if (ea_buf->mp == NULL) {
562 dbFree(inode, blkno, (s64) blocks_needed);
563 rc = -EIO;
564 goto clean_up;
565 }
566 ea_buf->xattr = ea_buf->mp->data;
567 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
568 ~(sb->s_blocksize - 1);
569 if (ea_size == 0)
570 return 0;
571 if ((rc = ea_read(inode, ea_buf->xattr))) {
572 discard_metapage(ea_buf->mp);
573 dbFree(inode, blkno, (s64) blocks_needed);
574 goto clean_up;
575 }
576 goto size_check;
577 }
578 ea_buf->flag = EA_EXTENT;
579 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
580 lengthDXD(&ji->ea) << sb->s_blocksize_bits,
581 1);
582 if (ea_buf->mp == NULL) {
583 rc = -EIO;
584 goto clean_up;
585 }
586 ea_buf->xattr = ea_buf->mp->data;
587 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
588 ~(sb->s_blocksize - 1);
589
590 size_check:
591 if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
592 printk(KERN_ERR "ea_get: invalid extended attribute\n");
593 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
594 ea_buf->xattr, ea_size, 1);
595 ea_release(inode, ea_buf);
596 rc = -EIO;
597 goto clean_up;
598 }
599
600 return ea_size;
601
602 clean_up:
603 /* Rollback quota allocation */
604 if (quota_allocation)
605 DQUOT_FREE_BLOCK(inode, quota_allocation);
606
607 return (rc);
608 }
609
610 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
611 {
612 if (ea_buf->flag & EA_MALLOC)
613 kfree(ea_buf->xattr);
614 else if (ea_buf->flag & EA_EXTENT) {
615 assert(ea_buf->mp);
616 release_metapage(ea_buf->mp);
617
618 if (ea_buf->flag & EA_NEW)
619 dbFree(inode, addressDXD(&ea_buf->new_ea),
620 lengthDXD(&ea_buf->new_ea));
621 }
622 }
623
624 static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
625 int new_size)
626 {
627 struct jfs_inode_info *ji = JFS_IP(inode);
628 unsigned long old_blocks, new_blocks;
629 int rc = 0;
630
631 if (new_size == 0) {
632 ea_release(inode, ea_buf);
633 ea_buf = NULL;
634 } else if (ea_buf->flag & EA_INLINE) {
635 assert(new_size <= sizeof (ji->i_inline_ea));
636 ji->mode2 &= ~INLINEEA;
637 ea_buf->new_ea.flag = DXD_INLINE;
638 DXDsize(&ea_buf->new_ea, new_size);
639 DXDaddress(&ea_buf->new_ea, 0);
640 DXDlength(&ea_buf->new_ea, 0);
641 } else if (ea_buf->flag & EA_MALLOC) {
642 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
643 kfree(ea_buf->xattr);
644 } else if (ea_buf->flag & EA_NEW) {
645 /* We have already allocated a new dxd */
646 flush_metapage(ea_buf->mp);
647 } else {
648 /* ->xattr must point to original ea's metapage */
649 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
650 discard_metapage(ea_buf->mp);
651 }
652 if (rc)
653 return rc;
654
655 old_blocks = new_blocks = 0;
656
657 if (ji->ea.flag & DXD_EXTENT) {
658 invalidate_dxd_metapages(inode, ji->ea);
659 old_blocks = lengthDXD(&ji->ea);
660 }
661
662 if (ea_buf) {
663 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
664 if (ea_buf->new_ea.flag & DXD_EXTENT) {
665 new_blocks = lengthDXD(&ea_buf->new_ea);
666 if (ji->ea.flag & DXD_INLINE)
667 ji->mode2 |= INLINEEA;
668 }
669 ji->ea = ea_buf->new_ea;
670 } else {
671 txEA(tid, inode, &ji->ea, NULL);
672 if (ji->ea.flag & DXD_INLINE)
673 ji->mode2 |= INLINEEA;
674 ji->ea.flag = 0;
675 ji->ea.size = 0;
676 }
677
678 /* If old blocks exist, they must be removed from quota allocation. */
679 if (old_blocks)
680 DQUOT_FREE_BLOCK(inode, old_blocks);
681
682 inode->i_ctime = CURRENT_TIME;
683
684 return 0;
685 }
686
687 /*
688 * can_set_system_xattr
689 *
690 * This code is specific to the system.* namespace. It contains policy
691 * which doesn't belong in the main xattr codepath.
692 */
693 static int can_set_system_xattr(struct inode *inode, const char *name,
694 const void *value, size_t value_len)
695 {
696 #ifdef CONFIG_JFS_POSIX_ACL
697 struct posix_acl *acl;
698 int rc;
699
700 if (!is_owner_or_cap(inode))
701 return -EPERM;
702
703 /*
704 * POSIX_ACL_XATTR_ACCESS is tied to i_mode
705 */
706 if (strcmp(name, POSIX_ACL_XATTR_ACCESS) == 0) {
707 acl = posix_acl_from_xattr(value, value_len);
708 if (IS_ERR(acl)) {
709 rc = PTR_ERR(acl);
710 printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
711 rc);
712 return rc;
713 }
714 if (acl) {
715 mode_t mode = inode->i_mode;
716 rc = posix_acl_equiv_mode(acl, &mode);
717 posix_acl_release(acl);
718 if (rc < 0) {
719 printk(KERN_ERR
720 "posix_acl_equiv_mode returned %d\n",
721 rc);
722 return rc;
723 }
724 inode->i_mode = mode;
725 mark_inode_dirty(inode);
726 }
727 /*
728 * We're changing the ACL. Get rid of the cached one
729 */
730 acl =JFS_IP(inode)->i_acl;
731 if (acl != JFS_ACL_NOT_CACHED)
732 posix_acl_release(acl);
733 JFS_IP(inode)->i_acl = JFS_ACL_NOT_CACHED;
734
735 return 0;
736 } else if (strcmp(name, POSIX_ACL_XATTR_DEFAULT) == 0) {
737 acl = posix_acl_from_xattr(value, value_len);
738 if (IS_ERR(acl)) {
739 rc = PTR_ERR(acl);
740 printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
741 rc);
742 return rc;
743 }
744 posix_acl_release(acl);
745
746 /*
747 * We're changing the default ACL. Get rid of the cached one
748 */
749 acl =JFS_IP(inode)->i_default_acl;
750 if (acl && (acl != JFS_ACL_NOT_CACHED))
751 posix_acl_release(acl);
752 JFS_IP(inode)->i_default_acl = JFS_ACL_NOT_CACHED;
753
754 return 0;
755 }
756 #endif /* CONFIG_JFS_POSIX_ACL */
757 return -EOPNOTSUPP;
758 }
759
760 /*
761 * Most of the permission checking is done by xattr_permission in the vfs.
762 * The local file system is responsible for handling the system.* namespace.
763 * We also need to verify that this is a namespace that we recognize.
764 */
765 static int can_set_xattr(struct inode *inode, const char *name,
766 const void *value, size_t value_len)
767 {
768 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
769 return can_set_system_xattr(inode, name, value, value_len);
770
771 /*
772 * Don't allow setting an attribute in an unknown namespace.
773 */
774 if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
775 strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
776 strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
777 strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN))
778 return -EOPNOTSUPP;
779
780 return 0;
781 }
782
783 int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
784 const void *value, size_t value_len, int flags)
785 {
786 struct jfs_ea_list *ealist;
787 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
788 struct ea_buffer ea_buf;
789 int old_ea_size = 0;
790 int xattr_size;
791 int new_size;
792 int namelen = strlen(name);
793 char *os2name = NULL;
794 int found = 0;
795 int rc;
796 int length;
797
798 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
799 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
800 GFP_KERNEL);
801 if (!os2name)
802 return -ENOMEM;
803 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
804 name = os2name;
805 namelen -= XATTR_OS2_PREFIX_LEN;
806 }
807
808 down_write(&JFS_IP(inode)->xattr_sem);
809
810 xattr_size = ea_get(inode, &ea_buf, 0);
811 if (xattr_size < 0) {
812 rc = xattr_size;
813 goto out;
814 }
815
816 again:
817 ealist = (struct jfs_ea_list *) ea_buf.xattr;
818 new_size = sizeof (struct jfs_ea_list);
819
820 if (xattr_size) {
821 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
822 ea = NEXT_EA(ea)) {
823 if ((namelen == ea->namelen) &&
824 (memcmp(name, ea->name, namelen) == 0)) {
825 found = 1;
826 if (flags & XATTR_CREATE) {
827 rc = -EEXIST;
828 goto release;
829 }
830 old_ea = ea;
831 old_ea_size = EA_SIZE(ea);
832 next_ea = NEXT_EA(ea);
833 } else
834 new_size += EA_SIZE(ea);
835 }
836 }
837
838 if (!found) {
839 if (flags & XATTR_REPLACE) {
840 rc = -ENODATA;
841 goto release;
842 }
843 if (value == NULL) {
844 rc = 0;
845 goto release;
846 }
847 }
848 if (value)
849 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
850
851 if (new_size > ea_buf.max_size) {
852 /*
853 * We need to allocate more space for merged ea list.
854 * We should only have loop to again: once.
855 */
856 ea_release(inode, &ea_buf);
857 xattr_size = ea_get(inode, &ea_buf, new_size);
858 if (xattr_size < 0) {
859 rc = xattr_size;
860 goto out;
861 }
862 goto again;
863 }
864
865 /* Remove old ea of the same name */
866 if (found) {
867 /* number of bytes following target EA */
868 length = (char *) END_EALIST(ealist) - (char *) next_ea;
869 if (length > 0)
870 memmove(old_ea, next_ea, length);
871 xattr_size -= old_ea_size;
872 }
873
874 /* Add new entry to the end */
875 if (value) {
876 if (xattr_size == 0)
877 /* Completely new ea list */
878 xattr_size = sizeof (struct jfs_ea_list);
879
880 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
881 ea->flag = 0;
882 ea->namelen = namelen;
883 ea->valuelen = (cpu_to_le16(value_len));
884 memcpy(ea->name, name, namelen);
885 ea->name[namelen] = 0;
886 if (value_len)
887 memcpy(&ea->name[namelen + 1], value, value_len);
888 xattr_size += EA_SIZE(ea);
889 }
890
891 /* DEBUG - If we did this right, these number match */
892 if (xattr_size != new_size) {
893 printk(KERN_ERR
894 "jfs_xsetattr: xattr_size = %d, new_size = %d\n",
895 xattr_size, new_size);
896
897 rc = -EINVAL;
898 goto release;
899 }
900
901 /*
902 * If we're left with an empty list, there's no ea
903 */
904 if (new_size == sizeof (struct jfs_ea_list))
905 new_size = 0;
906
907 ealist->size = cpu_to_le32(new_size);
908
909 rc = ea_put(tid, inode, &ea_buf, new_size);
910
911 goto out;
912 release:
913 ea_release(inode, &ea_buf);
914 out:
915 up_write(&JFS_IP(inode)->xattr_sem);
916
917 kfree(os2name);
918
919 return rc;
920 }
921
922 int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
923 size_t value_len, int flags)
924 {
925 struct inode *inode = dentry->d_inode;
926 struct jfs_inode_info *ji = JFS_IP(inode);
927 int rc;
928 tid_t tid;
929
930 if ((rc = can_set_xattr(inode, name, value, value_len)))
931 return rc;
932
933 if (value == NULL) { /* empty EA, do not remove */
934 value = "";
935 value_len = 0;
936 }
937
938 tid = txBegin(inode->i_sb, 0);
939 mutex_lock(&ji->commit_mutex);
940 rc = __jfs_setxattr(tid, dentry->d_inode, name, value, value_len,
941 flags);
942 if (!rc)
943 rc = txCommit(tid, 1, &inode, 0);
944 txEnd(tid);
945 mutex_unlock(&ji->commit_mutex);
946
947 return rc;
948 }
949
950 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
951 size_t buf_size)
952 {
953 struct jfs_ea_list *ealist;
954 struct jfs_ea *ea;
955 struct ea_buffer ea_buf;
956 int xattr_size;
957 ssize_t size;
958 int namelen = strlen(name);
959 char *os2name = NULL;
960 char *value;
961
962 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
963 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
964 GFP_KERNEL);
965 if (!os2name)
966 return -ENOMEM;
967 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
968 name = os2name;
969 namelen -= XATTR_OS2_PREFIX_LEN;
970 }
971
972 down_read(&JFS_IP(inode)->xattr_sem);
973
974 xattr_size = ea_get(inode, &ea_buf, 0);
975
976 if (xattr_size < 0) {
977 size = xattr_size;
978 goto out;
979 }
980
981 if (xattr_size == 0)
982 goto not_found;
983
984 ealist = (struct jfs_ea_list *) ea_buf.xattr;
985
986 /* Find the named attribute */
987 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
988 if ((namelen == ea->namelen) &&
989 memcmp(name, ea->name, namelen) == 0) {
990 /* Found it */
991 size = le16_to_cpu(ea->valuelen);
992 if (!data)
993 goto release;
994 else if (size > buf_size) {
995 size = -ERANGE;
996 goto release;
997 }
998 value = ((char *) &ea->name) + ea->namelen + 1;
999 memcpy(data, value, size);
1000 goto release;
1001 }
1002 not_found:
1003 size = -ENODATA;
1004 release:
1005 ea_release(inode, &ea_buf);
1006 out:
1007 up_read(&JFS_IP(inode)->xattr_sem);
1008
1009 kfree(os2name);
1010
1011 return size;
1012 }
1013
1014 ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
1015 size_t buf_size)
1016 {
1017 int err;
1018
1019 err = __jfs_getxattr(dentry->d_inode, name, data, buf_size);
1020
1021 return err;
1022 }
1023
1024 /*
1025 * No special permissions are needed to list attributes except for trusted.*
1026 */
1027 static inline int can_list(struct jfs_ea *ea)
1028 {
1029 return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
1030 XATTR_TRUSTED_PREFIX_LEN) ||
1031 capable(CAP_SYS_ADMIN));
1032 }
1033
1034 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
1035 {
1036 struct inode *inode = dentry->d_inode;
1037 char *buffer;
1038 ssize_t size = 0;
1039 int xattr_size;
1040 struct jfs_ea_list *ealist;
1041 struct jfs_ea *ea;
1042 struct ea_buffer ea_buf;
1043
1044 down_read(&JFS_IP(inode)->xattr_sem);
1045
1046 xattr_size = ea_get(inode, &ea_buf, 0);
1047 if (xattr_size < 0) {
1048 size = xattr_size;
1049 goto out;
1050 }
1051
1052 if (xattr_size == 0)
1053 goto release;
1054
1055 ealist = (struct jfs_ea_list *) ea_buf.xattr;
1056
1057 /* compute required size of list */
1058 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1059 if (can_list(ea))
1060 size += name_size(ea) + 1;
1061 }
1062
1063 if (!data)
1064 goto release;
1065
1066 if (size > buf_size) {
1067 size = -ERANGE;
1068 goto release;
1069 }
1070
1071 /* Copy attribute names to buffer */
1072 buffer = data;
1073 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1074 if (can_list(ea)) {
1075 int namelen = copy_name(buffer, ea);
1076 buffer += namelen + 1;
1077 }
1078 }
1079
1080 release:
1081 ea_release(inode, &ea_buf);
1082 out:
1083 up_read(&JFS_IP(inode)->xattr_sem);
1084 return size;
1085 }
1086
1087 int jfs_removexattr(struct dentry *dentry, const char *name)
1088 {
1089 struct inode *inode = dentry->d_inode;
1090 struct jfs_inode_info *ji = JFS_IP(inode);
1091 int rc;
1092 tid_t tid;
1093
1094 if ((rc = can_set_xattr(inode, name, NULL, 0)))
1095 return rc;
1096
1097 tid = txBegin(inode->i_sb, 0);
1098 mutex_lock(&ji->commit_mutex);
1099 rc = __jfs_setxattr(tid, dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
1100 if (!rc)
1101 rc = txCommit(tid, 1, &inode, 0);
1102 txEnd(tid);
1103 mutex_unlock(&ji->commit_mutex);
1104
1105 return rc;
1106 }
1107
1108 #ifdef CONFIG_JFS_SECURITY
1109 int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir)
1110 {
1111 int rc;
1112 size_t len;
1113 void *value;
1114 char *suffix;
1115 char *name;
1116
1117 rc = security_inode_init_security(inode, dir, &suffix, &value, &len);
1118 if (rc) {
1119 if (rc == -EOPNOTSUPP)
1120 return 0;
1121 return rc;
1122 }
1123 name = kmalloc(XATTR_SECURITY_PREFIX_LEN + 1 + strlen(suffix),
1124 GFP_NOFS);
1125 if (!name) {
1126 rc = -ENOMEM;
1127 goto kmalloc_failed;
1128 }
1129 strcpy(name, XATTR_SECURITY_PREFIX);
1130 strcpy(name + XATTR_SECURITY_PREFIX_LEN, suffix);
1131
1132 rc = __jfs_setxattr(tid, inode, name, value, len, 0);
1133
1134 kfree(name);
1135 kmalloc_failed:
1136 kfree(suffix);
1137 kfree(value);
1138
1139 return rc;
1140 }
1141 #endif
kmemtrace - Kernel memory tracer