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s390/uaccess: fix whitespace damage
[linux-2.6/btrfs-unstable.git] / fs / jfs / xattr.c
blob0bf3c33aedff9ecca4bbcaa11f04685b00671322
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 /*
90 * Mapping of on-disk attribute names: for on-disk attribute names with an
91 * unknown prefix (not "system.", "user.", "security.", or "trusted."), the
92 * prefix "os2." is prepended. On the way back to disk, "os2." prefixes are
93 * stripped and we make sure that the remaining name does not start with one
94 * of the know prefixes.
95 */
96
97 static int is_known_namespace(const char *name)
98 {
99 if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
100 strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
101 strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
102 strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
103 return false;
104
105 return true;
106 }
107
108 static inline int name_size(struct jfs_ea *ea)
109 {
110 if (is_known_namespace(ea->name))
111 return ea->namelen;
112 else
113 return ea->namelen + XATTR_OS2_PREFIX_LEN;
114 }
115
116 static inline int copy_name(char *buffer, struct jfs_ea *ea)
117 {
118 int len = ea->namelen;
119
120 if (!is_known_namespace(ea->name)) {
121 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
122 buffer += XATTR_OS2_PREFIX_LEN;
123 len += XATTR_OS2_PREFIX_LEN;
124 }
125 memcpy(buffer, ea->name, ea->namelen);
126 buffer[ea->namelen] = 0;
127
128 return len;
129 }
130
131 /* Forward references */
132 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
133
134 /*
135 * NAME: ea_write_inline
136 *
137 * FUNCTION: Attempt to write an EA inline if area is available
138 *
139 * PRE CONDITIONS:
140 * Already verified that the specified EA is small enough to fit inline
141 *
142 * PARAMETERS:
143 * ip - Inode pointer
144 * ealist - EA list pointer
145 * size - size of ealist in bytes
146 * ea - dxd_t structure to be filled in with necessary EA information
147 * if we successfully copy the EA inline
148 *
149 * NOTES:
150 * Checks if the inode's inline area is available. If so, copies EA inline
151 * and sets <ea> fields appropriately. Otherwise, returns failure, EA will
152 * have to be put into an extent.
153 *
154 * RETURNS: 0 for successful copy to inline area; -1 if area not available
155 */
156 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
157 int size, dxd_t * ea)
158 {
159 struct jfs_inode_info *ji = JFS_IP(ip);
160
161 /*
162 * Make sure we have an EA -- the NULL EA list is valid, but you
163 * can't copy it!
164 */
165 if (ealist && size > sizeof (struct jfs_ea_list)) {
166 assert(size <= sizeof (ji->i_inline_ea));
167
168 /*
169 * See if the space is available or if it is already being
170 * used for an inline EA.
171 */
172 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
173 return -EPERM;
174
175 DXDsize(ea, size);
176 DXDlength(ea, 0);
177 DXDaddress(ea, 0);
178 memcpy(ji->i_inline_ea, ealist, size);
179 ea->flag = DXD_INLINE;
180 ji->mode2 &= ~INLINEEA;
181 } else {
182 ea->flag = 0;
183 DXDsize(ea, 0);
184 DXDlength(ea, 0);
185 DXDaddress(ea, 0);
186
187 /* Free up INLINE area */
188 if (ji->ea.flag & DXD_INLINE)
189 ji->mode2 |= INLINEEA;
190 }
191
192 return 0;
193 }
194
195 /*
196 * NAME: ea_write
197 *
198 * FUNCTION: Write an EA for an inode
199 *
200 * PRE CONDITIONS: EA has been verified
201 *
202 * PARAMETERS:
203 * ip - Inode pointer
204 * ealist - EA list pointer
205 * size - size of ealist in bytes
206 * ea - dxd_t structure to be filled in appropriately with where the
207 * EA was copied
208 *
209 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
210 * extent and synchronously writes it to those blocks.
211 *
212 * RETURNS: 0 for success; Anything else indicates failure
213 */
214 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
215 dxd_t * ea)
216 {
217 struct super_block *sb = ip->i_sb;
218 struct jfs_inode_info *ji = JFS_IP(ip);
219 struct jfs_sb_info *sbi = JFS_SBI(sb);
220 int nblocks;
221 s64 blkno;
222 int rc = 0, i;
223 char *cp;
224 s32 nbytes, nb;
225 s32 bytes_to_write;
226 struct metapage *mp;
227
228 /*
229 * Quick check to see if this is an in-linable EA. Short EAs
230 * and empty EAs are all in-linable, provided the space exists.
231 */
232 if (!ealist || size <= sizeof (ji->i_inline_ea)) {
233 if (!ea_write_inline(ip, ealist, size, ea))
234 return 0;
235 }
236
237 /* figure out how many blocks we need */
238 nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
239
240 /* Allocate new blocks to quota. */
241 rc = dquot_alloc_block(ip, nblocks);
242 if (rc)
243 return rc;
244
245 rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
246 if (rc) {
247 /*Rollback quota allocation. */
248 dquot_free_block(ip, nblocks);
249 return rc;
250 }
251
252 /*
253 * Now have nblocks worth of storage to stuff into the FEALIST.
254 * loop over the FEALIST copying data into the buffer one page at
255 * a time.
256 */
257 cp = (char *) ealist;
258 nbytes = size;
259 for (i = 0; i < nblocks; i += sbi->nbperpage) {
260 /*
261 * Determine how many bytes for this request, and round up to
262 * the nearest aggregate block size
263 */
264 nb = min(PSIZE, nbytes);
265 bytes_to_write =
266 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
267 << sb->s_blocksize_bits;
268
269 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
270 rc = -EIO;
271 goto failed;
272 }
273
274 memcpy(mp->data, cp, nb);
275
276 /*
277 * We really need a way to propagate errors for
278 * forced writes like this one. --hch
279 *
280 * (__write_metapage => release_metapage => flush_metapage)
281 */
282 #ifdef _JFS_FIXME
283 if ((rc = flush_metapage(mp))) {
284 /*
285 * the write failed -- this means that the buffer
286 * is still assigned and the blocks are not being
287 * used. this seems like the best error recovery
288 * we can get ...
289 */
290 goto failed;
291 }
292 #else
293 flush_metapage(mp);
294 #endif
295
296 cp += PSIZE;
297 nbytes -= nb;
298 }
299
300 ea->flag = DXD_EXTENT;
301 DXDsize(ea, le32_to_cpu(ealist->size));
302 DXDlength(ea, nblocks);
303 DXDaddress(ea, blkno);
304
305 /* Free up INLINE area */
306 if (ji->ea.flag & DXD_INLINE)
307 ji->mode2 |= INLINEEA;
308
309 return 0;
310
311 failed:
312 /* Rollback quota allocation. */
313 dquot_free_block(ip, nblocks);
314
315 dbFree(ip, blkno, nblocks);
316 return rc;
317 }
318
319 /*
320 * NAME: ea_read_inline
321 *
322 * FUNCTION: Read an inlined EA into user's buffer
323 *
324 * PARAMETERS:
325 * ip - Inode pointer
326 * ealist - Pointer to buffer to fill in with EA
327 *
328 * RETURNS: 0
329 */
330 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
331 {
332 struct jfs_inode_info *ji = JFS_IP(ip);
333 int ea_size = sizeDXD(&ji->ea);
334
335 if (ea_size == 0) {
336 ealist->size = 0;
337 return 0;
338 }
339
340 /* Sanity Check */
341 if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
342 return -EIO;
343 if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
344 != ea_size)
345 return -EIO;
346
347 memcpy(ealist, ji->i_inline_ea, ea_size);
348 return 0;
349 }
350
351 /*
352 * NAME: ea_read
353 *
354 * FUNCTION: copy EA data into user's buffer
355 *
356 * PARAMETERS:
357 * ip - Inode pointer
358 * ealist - Pointer to buffer to fill in with EA
359 *
360 * NOTES: If EA is inline calls ea_read_inline() to copy EA.
361 *
362 * RETURNS: 0 for success; other indicates failure
363 */
364 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
365 {
366 struct super_block *sb = ip->i_sb;
367 struct jfs_inode_info *ji = JFS_IP(ip);
368 struct jfs_sb_info *sbi = JFS_SBI(sb);
369 int nblocks;
370 s64 blkno;
371 char *cp = (char *) ealist;
372 int i;
373 int nbytes, nb;
374 s32 bytes_to_read;
375 struct metapage *mp;
376
377 /* quick check for in-line EA */
378 if (ji->ea.flag & DXD_INLINE)
379 return ea_read_inline(ip, ealist);
380
381 nbytes = sizeDXD(&ji->ea);
382 if (!nbytes) {
383 jfs_error(sb, "nbytes is 0\n");
384 return -EIO;
385 }
386
387 /*
388 * Figure out how many blocks were allocated when this EA list was
389 * originally written to disk.
390 */
391 nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
392 blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
393
394 /*
395 * I have found the disk blocks which were originally used to store
396 * the FEALIST. now i loop over each contiguous block copying the
397 * data into the buffer.
398 */
399 for (i = 0; i < nblocks; i += sbi->nbperpage) {
400 /*
401 * Determine how many bytes for this request, and round up to
402 * the nearest aggregate block size
403 */
404 nb = min(PSIZE, nbytes);
405 bytes_to_read =
406 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
407 << sb->s_blocksize_bits;
408
409 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
410 return -EIO;
411
412 memcpy(cp, mp->data, nb);
413 release_metapage(mp);
414
415 cp += PSIZE;
416 nbytes -= nb;
417 }
418
419 return 0;
420 }
421
422 /*
423 * NAME: ea_get
424 *
425 * FUNCTION: Returns buffer containing existing extended attributes.
426 * The size of the buffer will be the larger of the existing
427 * attributes size, or min_size.
428 *
429 * The buffer, which may be inlined in the inode or in the
430 * page cache must be release by calling ea_release or ea_put
431 *
432 * PARAMETERS:
433 * inode - Inode pointer
434 * ea_buf - Structure to be populated with ealist and its metadata
435 * min_size- minimum size of buffer to be returned
436 *
437 * RETURNS: 0 for success; Other indicates failure
438 */
439 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
440 {
441 struct jfs_inode_info *ji = JFS_IP(inode);
442 struct super_block *sb = inode->i_sb;
443 int size;
444 int ea_size = sizeDXD(&ji->ea);
445 int blocks_needed, current_blocks;
446 s64 blkno;
447 int rc;
448 int quota_allocation = 0;
449
450 /* When fsck.jfs clears a bad ea, it doesn't clear the size */
451 if (ji->ea.flag == 0)
452 ea_size = 0;
453
454 if (ea_size == 0) {
455 if (min_size == 0) {
456 ea_buf->flag = 0;
457 ea_buf->max_size = 0;
458 ea_buf->xattr = NULL;
459 return 0;
460 }
461 if ((min_size <= sizeof (ji->i_inline_ea)) &&
462 (ji->mode2 & INLINEEA)) {
463 ea_buf->flag = EA_INLINE | EA_NEW;
464 ea_buf->max_size = sizeof (ji->i_inline_ea);
465 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
466 DXDlength(&ea_buf->new_ea, 0);
467 DXDaddress(&ea_buf->new_ea, 0);
468 ea_buf->new_ea.flag = DXD_INLINE;
469 DXDsize(&ea_buf->new_ea, min_size);
470 return 0;
471 }
472 current_blocks = 0;
473 } else if (ji->ea.flag & DXD_INLINE) {
474 if (min_size <= sizeof (ji->i_inline_ea)) {
475 ea_buf->flag = EA_INLINE;
476 ea_buf->max_size = sizeof (ji->i_inline_ea);
477 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
478 goto size_check;
479 }
480 current_blocks = 0;
481 } else {
482 if (!(ji->ea.flag & DXD_EXTENT)) {
483 jfs_error(sb, "invalid ea.flag\n");
484 return -EIO;
485 }
486 current_blocks = (ea_size + sb->s_blocksize - 1) >>
487 sb->s_blocksize_bits;
488 }
489 size = max(min_size, ea_size);
490
491 if (size > PSIZE) {
492 /*
493 * To keep the rest of the code simple. Allocate a
494 * contiguous buffer to work with
495 */
496 ea_buf->xattr = kmalloc(size, GFP_KERNEL);
497 if (ea_buf->xattr == NULL)
498 return -ENOMEM;
499
500 ea_buf->flag = EA_MALLOC;
501 ea_buf->max_size = (size + sb->s_blocksize - 1) &
502 ~(sb->s_blocksize - 1);
503
504 if (ea_size == 0)
505 return 0;
506
507 if ((rc = ea_read(inode, ea_buf->xattr))) {
508 kfree(ea_buf->xattr);
509 ea_buf->xattr = NULL;
510 return rc;
511 }
512 goto size_check;
513 }
514 blocks_needed = (min_size + sb->s_blocksize - 1) >>
515 sb->s_blocksize_bits;
516
517 if (blocks_needed > current_blocks) {
518 /* Allocate new blocks to quota. */
519 rc = dquot_alloc_block(inode, blocks_needed);
520 if (rc)
521 return -EDQUOT;
522
523 quota_allocation = blocks_needed;
524
525 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
526 &blkno);
527 if (rc)
528 goto clean_up;
529
530 DXDlength(&ea_buf->new_ea, blocks_needed);
531 DXDaddress(&ea_buf->new_ea, blkno);
532 ea_buf->new_ea.flag = DXD_EXTENT;
533 DXDsize(&ea_buf->new_ea, min_size);
534
535 ea_buf->flag = EA_EXTENT | EA_NEW;
536
537 ea_buf->mp = get_metapage(inode, blkno,
538 blocks_needed << sb->s_blocksize_bits,
539 1);
540 if (ea_buf->mp == NULL) {
541 dbFree(inode, blkno, (s64) blocks_needed);
542 rc = -EIO;
543 goto clean_up;
544 }
545 ea_buf->xattr = ea_buf->mp->data;
546 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
547 ~(sb->s_blocksize - 1);
548 if (ea_size == 0)
549 return 0;
550 if ((rc = ea_read(inode, ea_buf->xattr))) {
551 discard_metapage(ea_buf->mp);
552 dbFree(inode, blkno, (s64) blocks_needed);
553 goto clean_up;
554 }
555 goto size_check;
556 }
557 ea_buf->flag = EA_EXTENT;
558 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
559 lengthDXD(&ji->ea) << sb->s_blocksize_bits,
560 1);
561 if (ea_buf->mp == NULL) {
562 rc = -EIO;
563 goto clean_up;
564 }
565 ea_buf->xattr = ea_buf->mp->data;
566 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
567 ~(sb->s_blocksize - 1);
568
569 size_check:
570 if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
571 printk(KERN_ERR "ea_get: invalid extended attribute\n");
572 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
573 ea_buf->xattr, ea_size, 1);
574 ea_release(inode, ea_buf);
575 rc = -EIO;
576 goto clean_up;
577 }
578
579 return ea_size;
580
581 clean_up:
582 /* Rollback quota allocation */
583 if (quota_allocation)
584 dquot_free_block(inode, quota_allocation);
585
586 return (rc);
587 }
588
589 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
590 {
591 if (ea_buf->flag & EA_MALLOC)
592 kfree(ea_buf->xattr);
593 else if (ea_buf->flag & EA_EXTENT) {
594 assert(ea_buf->mp);
595 release_metapage(ea_buf->mp);
596
597 if (ea_buf->flag & EA_NEW)
598 dbFree(inode, addressDXD(&ea_buf->new_ea),
599 lengthDXD(&ea_buf->new_ea));
600 }
601 }
602
603 static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
604 int new_size)
605 {
606 struct jfs_inode_info *ji = JFS_IP(inode);
607 unsigned long old_blocks, new_blocks;
608 int rc = 0;
609
610 if (new_size == 0) {
611 ea_release(inode, ea_buf);
612 ea_buf = NULL;
613 } else if (ea_buf->flag & EA_INLINE) {
614 assert(new_size <= sizeof (ji->i_inline_ea));
615 ji->mode2 &= ~INLINEEA;
616 ea_buf->new_ea.flag = DXD_INLINE;
617 DXDsize(&ea_buf->new_ea, new_size);
618 DXDaddress(&ea_buf->new_ea, 0);
619 DXDlength(&ea_buf->new_ea, 0);
620 } else if (ea_buf->flag & EA_MALLOC) {
621 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
622 kfree(ea_buf->xattr);
623 } else if (ea_buf->flag & EA_NEW) {
624 /* We have already allocated a new dxd */
625 flush_metapage(ea_buf->mp);
626 } else {
627 /* ->xattr must point to original ea's metapage */
628 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
629 discard_metapage(ea_buf->mp);
630 }
631 if (rc)
632 return rc;
633
634 old_blocks = new_blocks = 0;
635
636 if (ji->ea.flag & DXD_EXTENT) {
637 invalidate_dxd_metapages(inode, ji->ea);
638 old_blocks = lengthDXD(&ji->ea);
639 }
640
641 if (ea_buf) {
642 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
643 if (ea_buf->new_ea.flag & DXD_EXTENT) {
644 new_blocks = lengthDXD(&ea_buf->new_ea);
645 if (ji->ea.flag & DXD_INLINE)
646 ji->mode2 |= INLINEEA;
647 }
648 ji->ea = ea_buf->new_ea;
649 } else {
650 txEA(tid, inode, &ji->ea, NULL);
651 if (ji->ea.flag & DXD_INLINE)
652 ji->mode2 |= INLINEEA;
653 ji->ea.flag = 0;
654 ji->ea.size = 0;
655 }
656
657 /* If old blocks exist, they must be removed from quota allocation. */
658 if (old_blocks)
659 dquot_free_block(inode, old_blocks);
660
661 inode->i_ctime = CURRENT_TIME;
662
663 return 0;
664 }
665
666 int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
667 const void *value, size_t value_len, int flags)
668 {
669 struct jfs_ea_list *ealist;
670 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
671 struct ea_buffer ea_buf;
672 int old_ea_size = 0;
673 int xattr_size;
674 int new_size;
675 int namelen = strlen(name);
676 int found = 0;
677 int rc;
678 int length;
679
680 down_write(&JFS_IP(inode)->xattr_sem);
681
682 xattr_size = ea_get(inode, &ea_buf, 0);
683 if (xattr_size < 0) {
684 rc = xattr_size;
685 goto out;
686 }
687
688 again:
689 ealist = (struct jfs_ea_list *) ea_buf.xattr;
690 new_size = sizeof (struct jfs_ea_list);
691
692 if (xattr_size) {
693 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
694 ea = NEXT_EA(ea)) {
695 if ((namelen == ea->namelen) &&
696 (memcmp(name, ea->name, namelen) == 0)) {
697 found = 1;
698 if (flags & XATTR_CREATE) {
699 rc = -EEXIST;
700 goto release;
701 }
702 old_ea = ea;
703 old_ea_size = EA_SIZE(ea);
704 next_ea = NEXT_EA(ea);
705 } else
706 new_size += EA_SIZE(ea);
707 }
708 }
709
710 if (!found) {
711 if (flags & XATTR_REPLACE) {
712 rc = -ENODATA;
713 goto release;
714 }
715 if (value == NULL) {
716 rc = 0;
717 goto release;
718 }
719 }
720 if (value)
721 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
722
723 if (new_size > ea_buf.max_size) {
724 /*
725 * We need to allocate more space for merged ea list.
726 * We should only have loop to again: once.
727 */
728 ea_release(inode, &ea_buf);
729 xattr_size = ea_get(inode, &ea_buf, new_size);
730 if (xattr_size < 0) {
731 rc = xattr_size;
732 goto out;
733 }
734 goto again;
735 }
736
737 /* Remove old ea of the same name */
738 if (found) {
739 /* number of bytes following target EA */
740 length = (char *) END_EALIST(ealist) - (char *) next_ea;
741 if (length > 0)
742 memmove(old_ea, next_ea, length);
743 xattr_size -= old_ea_size;
744 }
745
746 /* Add new entry to the end */
747 if (value) {
748 if (xattr_size == 0)
749 /* Completely new ea list */
750 xattr_size = sizeof (struct jfs_ea_list);
751
752 /*
753 * The size of EA value is limitted by on-disk format up to
754 * __le16, there would be an overflow if the size is equal
755 * to XATTR_SIZE_MAX (65536). In order to avoid this issue,
756 * we can pre-checkup the value size against USHRT_MAX, and
757 * return -E2BIG in this case, which is consistent with the
758 * VFS setxattr interface.
759 */
760 if (value_len >= USHRT_MAX) {
761 rc = -E2BIG;
762 goto release;
763 }
764
765 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
766 ea->flag = 0;
767 ea->namelen = namelen;
768 ea->valuelen = (cpu_to_le16(value_len));
769 memcpy(ea->name, name, namelen);
770 ea->name[namelen] = 0;
771 if (value_len)
772 memcpy(&ea->name[namelen + 1], value, value_len);
773 xattr_size += EA_SIZE(ea);
774 }
775
776 /* DEBUG - If we did this right, these number match */
777 if (xattr_size != new_size) {
778 printk(KERN_ERR
779 "__jfs_setxattr: xattr_size = %d, new_size = %d\n",
780 xattr_size, new_size);
781
782 rc = -EINVAL;
783 goto release;
784 }
785
786 /*
787 * If we're left with an empty list, there's no ea
788 */
789 if (new_size == sizeof (struct jfs_ea_list))
790 new_size = 0;
791
792 ealist->size = cpu_to_le32(new_size);
793
794 rc = ea_put(tid, inode, &ea_buf, new_size);
795
796 goto out;
797 release:
798 ea_release(inode, &ea_buf);
799 out:
800 up_write(&JFS_IP(inode)->xattr_sem);
801
802 return rc;
803 }
804
805 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
806 size_t buf_size)
807 {
808 struct jfs_ea_list *ealist;
809 struct jfs_ea *ea;
810 struct ea_buffer ea_buf;
811 int xattr_size;
812 ssize_t size;
813 int namelen = strlen(name);
814 char *value;
815
816 down_read(&JFS_IP(inode)->xattr_sem);
817
818 xattr_size = ea_get(inode, &ea_buf, 0);
819
820 if (xattr_size < 0) {
821 size = xattr_size;
822 goto out;
823 }
824
825 if (xattr_size == 0)
826 goto not_found;
827
828 ealist = (struct jfs_ea_list *) ea_buf.xattr;
829
830 /* Find the named attribute */
831 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
832 if ((namelen == ea->namelen) &&
833 memcmp(name, ea->name, namelen) == 0) {
834 /* Found it */
835 size = le16_to_cpu(ea->valuelen);
836 if (!data)
837 goto release;
838 else if (size > buf_size) {
839 size = -ERANGE;
840 goto release;
841 }
842 value = ((char *) &ea->name) + ea->namelen + 1;
843 memcpy(data, value, size);
844 goto release;
845 }
846 not_found:
847 size = -ENODATA;
848 release:
849 ea_release(inode, &ea_buf);
850 out:
851 up_read(&JFS_IP(inode)->xattr_sem);
852
853 return size;
854 }
855
856 /*
857 * No special permissions are needed to list attributes except for trusted.*
858 */
859 static inline int can_list(struct jfs_ea *ea)
860 {
861 return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
862 XATTR_TRUSTED_PREFIX_LEN) ||
863 capable(CAP_SYS_ADMIN));
864 }
865
866 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
867 {
868 struct inode *inode = d_inode(dentry);
869 char *buffer;
870 ssize_t size = 0;
871 int xattr_size;
872 struct jfs_ea_list *ealist;
873 struct jfs_ea *ea;
874 struct ea_buffer ea_buf;
875
876 down_read(&JFS_IP(inode)->xattr_sem);
877
878 xattr_size = ea_get(inode, &ea_buf, 0);
879 if (xattr_size < 0) {
880 size = xattr_size;
881 goto out;
882 }
883
884 if (xattr_size == 0)
885 goto release;
886
887 ealist = (struct jfs_ea_list *) ea_buf.xattr;
888
889 /* compute required size of list */
890 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
891 if (can_list(ea))
892 size += name_size(ea) + 1;
893 }
894
895 if (!data)
896 goto release;
897
898 if (size > buf_size) {
899 size = -ERANGE;
900 goto release;
901 }
902
903 /* Copy attribute names to buffer */
904 buffer = data;
905 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
906 if (can_list(ea)) {
907 int namelen = copy_name(buffer, ea);
908 buffer += namelen + 1;
909 }
910 }
911
912 release:
913 ea_release(inode, &ea_buf);
914 out:
915 up_read(&JFS_IP(inode)->xattr_sem);
916 return size;
917 }
918
919 static int __jfs_xattr_set(struct inode *inode, const char *name,
920 const void *value, size_t size, int flags)
921 {
922 struct jfs_inode_info *ji = JFS_IP(inode);
923 tid_t tid;
924 int rc;
925
926 tid = txBegin(inode->i_sb, 0);
927 mutex_lock(&ji->commit_mutex);
928 rc = __jfs_setxattr(tid, inode, name, value, size, flags);
929 if (!rc)
930 rc = txCommit(tid, 1, &inode, 0);
931 txEnd(tid);
932 mutex_unlock(&ji->commit_mutex);
933
934 return rc;
935 }
936
937 static int jfs_xattr_get(const struct xattr_handler *handler,
938 struct dentry *unused, struct inode *inode,
939 const char *name, void *value, size_t size)
940 {
941 name = xattr_full_name(handler, name);
942 return __jfs_getxattr(inode, name, value, size);
943 }
944
945 static int jfs_xattr_set(const struct xattr_handler *handler,
946 struct dentry *unused, struct inode *inode,
947 const char *name, const void *value,
948 size_t size, int flags)
949 {
950 name = xattr_full_name(handler, name);
951 return __jfs_xattr_set(inode, name, value, size, flags);
952 }
953
954 static int jfs_xattr_get_os2(const struct xattr_handler *handler,
955 struct dentry *unused, struct inode *inode,
956 const char *name, void *value, size_t size)
957 {
958 if (is_known_namespace(name))
959 return -EOPNOTSUPP;
960 return __jfs_getxattr(inode, name, value, size);
961 }
962
963 static int jfs_xattr_set_os2(const struct xattr_handler *handler,
964 struct dentry *unused, struct inode *inode,
965 const char *name, const void *value,
966 size_t size, int flags)
967 {
968 if (is_known_namespace(name))
969 return -EOPNOTSUPP;
970 return __jfs_xattr_set(inode, name, value, size, flags);
971 }
972
973 static const struct xattr_handler jfs_user_xattr_handler = {
974 .prefix = XATTR_USER_PREFIX,
975 .get = jfs_xattr_get,
976 .set = jfs_xattr_set,
977 };
978
979 static const struct xattr_handler jfs_os2_xattr_handler = {
980 .prefix = XATTR_OS2_PREFIX,
981 .get = jfs_xattr_get_os2,
982 .set = jfs_xattr_set_os2,
983 };
984
985 static const struct xattr_handler jfs_security_xattr_handler = {
986 .prefix = XATTR_SECURITY_PREFIX,
987 .get = jfs_xattr_get,
988 .set = jfs_xattr_set,
989 };
990
991 static const struct xattr_handler jfs_trusted_xattr_handler = {
992 .prefix = XATTR_TRUSTED_PREFIX,
993 .get = jfs_xattr_get,
994 .set = jfs_xattr_set,
995 };
996
997 const struct xattr_handler *jfs_xattr_handlers[] = {
998 #ifdef CONFIG_JFS_POSIX_ACL
999 &posix_acl_access_xattr_handler,
1000 &posix_acl_default_xattr_handler,
1001 #endif
1002 &jfs_os2_xattr_handler,
1003 &jfs_user_xattr_handler,
1004 &jfs_security_xattr_handler,
1005 &jfs_trusted_xattr_handler,
1006 NULL,
1007 };
1008
1009
1010 #ifdef CONFIG_JFS_SECURITY
1011 static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
1012 void *fs_info)
1013 {
1014 const struct xattr *xattr;
1015 tid_t *tid = fs_info;
1016 char *name;
1017 int err = 0;
1018
1019 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
1020 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
1021 strlen(xattr->name) + 1, GFP_NOFS);
1022 if (!name) {
1023 err = -ENOMEM;
1024 break;
1025 }
1026 strcpy(name, XATTR_SECURITY_PREFIX);
1027 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
1028
1029 err = __jfs_setxattr(*tid, inode, name,
1030 xattr->value, xattr->value_len, 0);
1031 kfree(name);
1032 if (err < 0)
1033 break;
1034 }
1035 return err;
1036 }
1037
1038 int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
1039 const struct qstr *qstr)
1040 {
1041 return security_inode_init_security(inode, dir, qstr,
1042 &jfs_initxattrs, &tid);
1043 }
1044 #endif
(deprecated) Btrfs devel tree