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-rw-r--r--fs/jfs/xattr.c1127
1 files changed, 1127 insertions, 0 deletions
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
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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/fs.h>
21#include <linux/xattr.h>
22#include <linux/quotaops.h>
23#include "jfs_incore.h"
24#include "jfs_superblock.h"
25#include "jfs_dmap.h"
26#include "jfs_debug.h"
27#include "jfs_dinode.h"
28#include "jfs_extent.h"
29#include "jfs_metapage.h"
30#include "jfs_xattr.h"
31#include "jfs_acl.h"
32
33/*
34 * jfs_xattr.c: extended attribute service
35 *
36 * Overall design --
37 *
38 * Format:
39 *
40 * Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
41 * value) and a variable (0 or more) number of extended attribute
42 * entries. Each extended attribute entry (jfs_ea) is a <name,value> double
43 * where <name> is constructed from a null-terminated ascii string
44 * (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
45 * (1 ... 65535 bytes). The in-memory format is
46 *
47 * 0 1 2 4 4 + namelen + 1
48 * +-------+--------+--------+----------------+-------------------+
49 * | Flags | Name | Value | Name String \0 | Data . . . . |
50 * | | Length | Length | | |
51 * +-------+--------+--------+----------------+-------------------+
52 *
53 * A jfs_ea_list then is structured as
54 *
55 * 0 4 4 + EA_SIZE(ea1)
56 * +------------+-------------------+--------------------+-----
57 * | Overall EA | First FEA Element | Second FEA Element | .....
58 * | List Size | | |
59 * +------------+-------------------+--------------------+-----
60 *
61 * On-disk:
62 *
63 * FEALISTs are stored on disk using blocks allocated by dbAlloc() and
64 * written directly. An EA list may be in-lined in the inode if there is
65 * sufficient room available.
66 */
67
68struct ea_buffer {
69 int flag; /* Indicates what storage xattr points to */
70 int max_size; /* largest xattr that fits in current buffer */
71 dxd_t new_ea; /* dxd to replace ea when modifying xattr */
72 struct metapage *mp; /* metapage containing ea list */
73 struct jfs_ea_list *xattr; /* buffer containing ea list */
74};
75
76/*
77 * ea_buffer.flag values
78 */
79#define EA_INLINE 0x0001
80#define EA_EXTENT 0x0002
81#define EA_NEW 0x0004
82#define EA_MALLOC 0x0008
83
84/* Namespaces */
85#define XATTR_SYSTEM_PREFIX "system."
86#define XATTR_SYSTEM_PREFIX_LEN (sizeof (XATTR_SYSTEM_PREFIX) - 1)
87
88#define XATTR_USER_PREFIX "user."
89#define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1)
90
91#define XATTR_OS2_PREFIX "os2."
92#define XATTR_OS2_PREFIX_LEN (sizeof (XATTR_OS2_PREFIX) - 1)
93
94/* XATTR_SECURITY_PREFIX is defined in include/linux/xattr.h */
95#define XATTR_SECURITY_PREFIX_LEN (sizeof (XATTR_SECURITY_PREFIX) - 1)
96
97#define XATTR_TRUSTED_PREFIX "trusted."
98#define XATTR_TRUSTED_PREFIX_LEN (sizeof (XATTR_TRUSTED_PREFIX) - 1)
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 */
105static inline int is_os2_xattr(struct jfs_ea *ea)
106{
107 /*
108 * Check for "system."
109 */
110 if ((ea->namelen >= XATTR_SYSTEM_PREFIX_LEN) &&
111 !strncmp(ea->name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
112 return FALSE;
113 /*
114 * Check for "user."
115 */
116 if ((ea->namelen >= XATTR_USER_PREFIX_LEN) &&
117 !strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
118 return FALSE;
119 /*
120 * Check for "security."
121 */
122 if ((ea->namelen >= XATTR_SECURITY_PREFIX_LEN) &&
123 !strncmp(ea->name, XATTR_SECURITY_PREFIX,
124 XATTR_SECURITY_PREFIX_LEN))
125 return FALSE;
126 /*
127 * Check for "trusted."
128 */
129 if ((ea->namelen >= XATTR_TRUSTED_PREFIX_LEN) &&
130 !strncmp(ea->name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
131 return FALSE;
132 /*
133 * Add any other valid namespace prefixes here
134 */
135
136 /*
137 * We assume it's OS/2's flat namespace
138 */
139 return TRUE;
140}
141
142static inline int name_size(struct jfs_ea *ea)
143{
144 if (is_os2_xattr(ea))
145 return ea->namelen + XATTR_OS2_PREFIX_LEN;
146 else
147 return ea->namelen;
148}
149
150static inline int copy_name(char *buffer, struct jfs_ea *ea)
151{
152 int len = ea->namelen;
153
154 if (is_os2_xattr(ea)) {
155 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
156 buffer += XATTR_OS2_PREFIX_LEN;
157 len += XATTR_OS2_PREFIX_LEN;
158 }
159 memcpy(buffer, ea->name, ea->namelen);
160 buffer[ea->namelen] = 0;
161
162 return len;
163}
164
165/* Forward references */
166static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
167
168/*
169 * NAME: ea_write_inline
170 *
171 * FUNCTION: Attempt to write an EA inline if area is available
172 *
173 * PRE CONDITIONS:
174 * Already verified that the specified EA is small enough to fit inline
175 *
176 * PARAMETERS:
177 * ip - Inode pointer
178 * ealist - EA list pointer
179 * size - size of ealist in bytes
180 * ea - dxd_t structure to be filled in with necessary EA information
181 * if we successfully copy the EA inline
182 *
183 * NOTES:
184 * Checks if the inode's inline area is available. If so, copies EA inline
185 * and sets <ea> fields appropriately. Otherwise, returns failure, EA will
186 * have to be put into an extent.
187 *
188 * RETURNS: 0 for successful copy to inline area; -1 if area not available
189 */
190static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
191 int size, dxd_t * ea)
192{
193 struct jfs_inode_info *ji = JFS_IP(ip);
194
195 /*
196 * Make sure we have an EA -- the NULL EA list is valid, but you
197 * can't copy it!
198 */
199 if (ealist && size > sizeof (struct jfs_ea_list)) {
200 assert(size <= sizeof (ji->i_inline_ea));
201
202 /*
203 * See if the space is available or if it is already being
204 * used for an inline EA.
205 */
206 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
207 return -EPERM;
208
209 DXDsize(ea, size);
210 DXDlength(ea, 0);
211 DXDaddress(ea, 0);
212 memcpy(ji->i_inline_ea, ealist, size);
213 ea->flag = DXD_INLINE;
214 ji->mode2 &= ~INLINEEA;
215 } else {
216 ea->flag = 0;
217 DXDsize(ea, 0);
218 DXDlength(ea, 0);
219 DXDaddress(ea, 0);
220
221 /* Free up INLINE area */
222 if (ji->ea.flag & DXD_INLINE)
223 ji->mode2 |= INLINEEA;
224 }
225
226 return 0;
227}
228
229/*
230 * NAME: ea_write
231 *
232 * FUNCTION: Write an EA for an inode
233 *
234 * PRE CONDITIONS: EA has been verified
235 *
236 * PARAMETERS:
237 * ip - Inode pointer
238 * ealist - EA list pointer
239 * size - size of ealist in bytes
240 * ea - dxd_t structure to be filled in appropriately with where the
241 * EA was copied
242 *
243 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
244 * extent and synchronously writes it to those blocks.
245 *
246 * RETURNS: 0 for success; Anything else indicates failure
247 */
248static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
249 dxd_t * ea)
250{
251 struct super_block *sb = ip->i_sb;
252 struct jfs_inode_info *ji = JFS_IP(ip);
253 struct jfs_sb_info *sbi = JFS_SBI(sb);
254 int nblocks;
255 s64 blkno;
256 int rc = 0, i;
257 char *cp;
258 s32 nbytes, nb;
259 s32 bytes_to_write;
260 struct metapage *mp;
261
262 /*
263 * Quick check to see if this is an in-linable EA. Short EAs
264 * and empty EAs are all in-linable, provided the space exists.
265 */
266 if (!ealist || size <= sizeof (ji->i_inline_ea)) {
267 if (!ea_write_inline(ip, ealist, size, ea))
268 return 0;
269 }
270
271 /* figure out how many blocks we need */
272 nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
273
274 /* Allocate new blocks to quota. */
275 if (DQUOT_ALLOC_BLOCK(ip, nblocks)) {
276 return -EDQUOT;
277 }
278
279 rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
280 if (rc) {
281 /*Rollback quota allocation. */
282 DQUOT_FREE_BLOCK(ip, nblocks);
283 return rc;
284 }
285
286 /*
287 * Now have nblocks worth of storage to stuff into the FEALIST.
288 * loop over the FEALIST copying data into the buffer one page at
289 * a time.
290 */
291 cp = (char *) ealist;
292 nbytes = size;
293 for (i = 0; i < nblocks; i += sbi->nbperpage) {
294 /*
295 * Determine how many bytes for this request, and round up to
296 * the nearest aggregate block size
297 */
298 nb = min(PSIZE, nbytes);
299 bytes_to_write =
300 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
301 << sb->s_blocksize_bits;
302
303 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
304 rc = -EIO;
305 goto failed;
306 }
307
308 memcpy(mp->data, cp, nb);
309
310 /*
311 * We really need a way to propagate errors for
312 * forced writes like this one. --hch
313 *
314 * (__write_metapage => release_metapage => flush_metapage)
315 */
316#ifdef _JFS_FIXME
317 if ((rc = flush_metapage(mp))) {
318 /*
319 * the write failed -- this means that the buffer
320 * is still assigned and the blocks are not being
321 * used. this seems like the best error recovery
322 * we can get ...
323 */
324 goto failed;
325 }
326#else
327 flush_metapage(mp);
328#endif
329
330 cp += PSIZE;
331 nbytes -= nb;
332 }
333
334 ea->flag = DXD_EXTENT;
335 DXDsize(ea, le32_to_cpu(ealist->size));
336 DXDlength(ea, nblocks);
337 DXDaddress(ea, blkno);
338
339 /* Free up INLINE area */
340 if (ji->ea.flag & DXD_INLINE)
341 ji->mode2 |= INLINEEA;
342
343 return 0;
344
345 failed:
346 /* Rollback quota allocation. */
347 DQUOT_FREE_BLOCK(ip, nblocks);
348
349 dbFree(ip, blkno, nblocks);
350 return rc;
351}
352
353/*
354 * NAME: ea_read_inline
355 *
356 * FUNCTION: Read an inlined EA into user's buffer
357 *
358 * PARAMETERS:
359 * ip - Inode pointer
360 * ealist - Pointer to buffer to fill in with EA
361 *
362 * RETURNS: 0
363 */
364static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
365{
366 struct jfs_inode_info *ji = JFS_IP(ip);
367 int ea_size = sizeDXD(&ji->ea);
368
369 if (ea_size == 0) {
370 ealist->size = 0;
371 return 0;
372 }
373
374 /* Sanity Check */
375 if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
376 return -EIO;
377 if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
378 != ea_size)
379 return -EIO;
380
381 memcpy(ealist, ji->i_inline_ea, ea_size);
382 return 0;
383}
384
385/*
386 * NAME: ea_read
387 *
388 * FUNCTION: copy EA data into user's buffer
389 *
390 * PARAMETERS:
391 * ip - Inode pointer
392 * ealist - Pointer to buffer to fill in with EA
393 *
394 * NOTES: If EA is inline calls ea_read_inline() to copy EA.
395 *
396 * RETURNS: 0 for success; other indicates failure
397 */
398static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
399{
400 struct super_block *sb = ip->i_sb;
401 struct jfs_inode_info *ji = JFS_IP(ip);
402 struct jfs_sb_info *sbi = JFS_SBI(sb);
403 int nblocks;
404 s64 blkno;
405 char *cp = (char *) ealist;
406 int i;
407 int nbytes, nb;
408 s32 bytes_to_read;
409 struct metapage *mp;
410
411 /* quick check for in-line EA */
412 if (ji->ea.flag & DXD_INLINE)
413 return ea_read_inline(ip, ealist);
414
415 nbytes = sizeDXD(&ji->ea);
416 if (!nbytes) {
417 jfs_error(sb, "ea_read: nbytes is 0");
418 return -EIO;
419 }
420
421 /*
422 * Figure out how many blocks were allocated when this EA list was
423 * originally written to disk.
424 */
425 nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
426 blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
427
428 /*
429 * I have found the disk blocks which were originally used to store
430 * the FEALIST. now i loop over each contiguous block copying the
431 * data into the buffer.
432 */
433 for (i = 0; i < nblocks; i += sbi->nbperpage) {
434 /*
435 * Determine how many bytes for this request, and round up to
436 * the nearest aggregate block size
437 */
438 nb = min(PSIZE, nbytes);
439 bytes_to_read =
440 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
441 << sb->s_blocksize_bits;
442
443 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
444 return -EIO;
445
446 memcpy(cp, mp->data, nb);
447 release_metapage(mp);
448
449 cp += PSIZE;
450 nbytes -= nb;
451 }
452
453 return 0;
454}
455
456/*
457 * NAME: ea_get
458 *
459 * FUNCTION: Returns buffer containing existing extended attributes.
460 * The size of the buffer will be the larger of the existing
461 * attributes size, or min_size.
462 *
463 * The buffer, which may be inlined in the inode or in the
464 * page cache must be release by calling ea_release or ea_put
465 *
466 * PARAMETERS:
467 * inode - Inode pointer
468 * ea_buf - Structure to be populated with ealist and its metadata
469 * min_size- minimum size of buffer to be returned
470 *
471 * RETURNS: 0 for success; Other indicates failure
472 */
473static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
474{
475 struct jfs_inode_info *ji = JFS_IP(inode);
476 struct super_block *sb = inode->i_sb;
477 int size;
478 int ea_size = sizeDXD(&ji->ea);
479 int blocks_needed, current_blocks;
480 s64 blkno;
481 int rc;
482 int quota_allocation = 0;
483
484 /* When fsck.jfs clears a bad ea, it doesn't clear the size */
485 if (ji->ea.flag == 0)
486 ea_size = 0;
487
488 if (ea_size == 0) {
489 if (min_size == 0) {
490 ea_buf->flag = 0;
491 ea_buf->max_size = 0;
492 ea_buf->xattr = NULL;
493 return 0;
494 }
495 if ((min_size <= sizeof (ji->i_inline_ea)) &&
496 (ji->mode2 & INLINEEA)) {
497 ea_buf->flag = EA_INLINE | EA_NEW;
498 ea_buf->max_size = sizeof (ji->i_inline_ea);
499 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
500 DXDlength(&ea_buf->new_ea, 0);
501 DXDaddress(&ea_buf->new_ea, 0);
502 ea_buf->new_ea.flag = DXD_INLINE;
503 DXDsize(&ea_buf->new_ea, min_size);
504 return 0;
505 }
506 current_blocks = 0;
507 } else if (ji->ea.flag & DXD_INLINE) {
508 if (min_size <= sizeof (ji->i_inline_ea)) {
509 ea_buf->flag = EA_INLINE;
510 ea_buf->max_size = sizeof (ji->i_inline_ea);
511 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
512 goto size_check;
513 }
514 current_blocks = 0;
515 } else {
516 if (!(ji->ea.flag & DXD_EXTENT)) {
517 jfs_error(sb, "ea_get: invalid ea.flag)");
518 return -EIO;
519 }
520 current_blocks = (ea_size + sb->s_blocksize - 1) >>
521 sb->s_blocksize_bits;
522 }
523 size = max(min_size, ea_size);
524
525 if (size > PSIZE) {
526 /*
527 * To keep the rest of the code simple. Allocate a
528 * contiguous buffer to work with
529 */
530 ea_buf->xattr = kmalloc(size, GFP_KERNEL);
531 if (ea_buf->xattr == NULL)
532 return -ENOMEM;
533
534 ea_buf->flag = EA_MALLOC;
535 ea_buf->max_size = (size + sb->s_blocksize - 1) &
536 ~(sb->s_blocksize - 1);
537
538 if (ea_size == 0)
539 return 0;
540
541 if ((rc = ea_read(inode, ea_buf->xattr))) {
542 kfree(ea_buf->xattr);
543 ea_buf->xattr = NULL;
544 return rc;
545 }
546 goto size_check;
547 }
548 blocks_needed = (min_size + sb->s_blocksize - 1) >>
549 sb->s_blocksize_bits;
550
551 if (blocks_needed > current_blocks) {
552 /* Allocate new blocks to quota. */
553 if (DQUOT_ALLOC_BLOCK(inode, blocks_needed))
554 return -EDQUOT;
555
556 quota_allocation = blocks_needed;
557
558 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
559 &blkno);
560 if (rc)
561 goto clean_up;
562
563 DXDlength(&ea_buf->new_ea, blocks_needed);
564 DXDaddress(&ea_buf->new_ea, blkno);
565 ea_buf->new_ea.flag = DXD_EXTENT;
566 DXDsize(&ea_buf->new_ea, min_size);
567
568 ea_buf->flag = EA_EXTENT | EA_NEW;
569
570 ea_buf->mp = get_metapage(inode, blkno,
571 blocks_needed << sb->s_blocksize_bits,
572 1);
573 if (ea_buf->mp == NULL) {
574 dbFree(inode, blkno, (s64) blocks_needed);
575 rc = -EIO;
576 goto clean_up;
577 }
578 ea_buf->xattr = ea_buf->mp->data;
579 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
580 ~(sb->s_blocksize - 1);
581 if (ea_size == 0)
582 return 0;
583 if ((rc = ea_read(inode, ea_buf->xattr))) {
584 discard_metapage(ea_buf->mp);
585 dbFree(inode, blkno, (s64) blocks_needed);
586 goto clean_up;
587 }
588 goto size_check;
589 }
590 ea_buf->flag = EA_EXTENT;
591 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
592 lengthDXD(&ji->ea) << sb->s_blocksize_bits,
593 1);
594 if (ea_buf->mp == NULL) {
595 rc = -EIO;
596 goto clean_up;
597 }
598 ea_buf->xattr = ea_buf->mp->data;
599 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
600 ~(sb->s_blocksize - 1);
601
602 size_check:
603 if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
604 printk(KERN_ERR "ea_get: invalid extended attribute\n");
605 dump_mem("xattr", ea_buf->xattr, ea_size);
606 ea_release(inode, ea_buf);
607 rc = -EIO;
608 goto clean_up;
609 }
610
611 return ea_size;
612
613 clean_up:
614 /* Rollback quota allocation */
615 if (quota_allocation)
616 DQUOT_FREE_BLOCK(inode, quota_allocation);
617
618 return (rc);
619}
620
621static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
622{
623 if (ea_buf->flag & EA_MALLOC)
624 kfree(ea_buf->xattr);
625 else if (ea_buf->flag & EA_EXTENT) {
626 assert(ea_buf->mp);
627 release_metapage(ea_buf->mp);
628
629 if (ea_buf->flag & EA_NEW)
630 dbFree(inode, addressDXD(&ea_buf->new_ea),
631 lengthDXD(&ea_buf->new_ea));
632 }
633}
634
635static int ea_put(struct inode *inode, struct ea_buffer *ea_buf, int new_size)
636{
637 struct jfs_inode_info *ji = JFS_IP(inode);
638 unsigned long old_blocks, new_blocks;
639 int rc = 0;
640 tid_t tid;
641
642 if (new_size == 0) {
643 ea_release(inode, ea_buf);
644 ea_buf = NULL;
645 } else if (ea_buf->flag & EA_INLINE) {
646 assert(new_size <= sizeof (ji->i_inline_ea));
647 ji->mode2 &= ~INLINEEA;
648 ea_buf->new_ea.flag = DXD_INLINE;
649 DXDsize(&ea_buf->new_ea, new_size);
650 DXDaddress(&ea_buf->new_ea, 0);
651 DXDlength(&ea_buf->new_ea, 0);
652 } else if (ea_buf->flag & EA_MALLOC) {
653 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
654 kfree(ea_buf->xattr);
655 } else if (ea_buf->flag & EA_NEW) {
656 /* We have already allocated a new dxd */
657 flush_metapage(ea_buf->mp);
658 } else {
659 /* ->xattr must point to original ea's metapage */
660 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
661 discard_metapage(ea_buf->mp);
662 }
663 if (rc)
664 return rc;
665
666 tid = txBegin(inode->i_sb, 0);
667 down(&ji->commit_sem);
668
669 old_blocks = new_blocks = 0;
670
671 if (ji->ea.flag & DXD_EXTENT) {
672 invalidate_dxd_metapages(inode, ji->ea);
673 old_blocks = lengthDXD(&ji->ea);
674 }
675
676 if (ea_buf) {
677 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
678 if (ea_buf->new_ea.flag & DXD_EXTENT) {
679 new_blocks = lengthDXD(&ea_buf->new_ea);
680 if (ji->ea.flag & DXD_INLINE)
681 ji->mode2 |= INLINEEA;
682 }
683 ji->ea = ea_buf->new_ea;
684 } else {
685 txEA(tid, inode, &ji->ea, NULL);
686 if (ji->ea.flag & DXD_INLINE)
687 ji->mode2 |= INLINEEA;
688 ji->ea.flag = 0;
689 ji->ea.size = 0;
690 }
691
692 /* If old blocks exist, they must be removed from quota allocation. */
693 if (old_blocks)
694 DQUOT_FREE_BLOCK(inode, old_blocks);
695
696 inode->i_ctime = CURRENT_TIME;
697 rc = txCommit(tid, 1, &inode, 0);
698 txEnd(tid);
699 up(&ji->commit_sem);
700
701 return rc;
702}
703
704/*
705 * can_set_system_xattr
706 *
707 * This code is specific to the system.* namespace. It contains policy
708 * which doesn't belong in the main xattr codepath.
709 */
710static int can_set_system_xattr(struct inode *inode, const char *name,
711 const void *value, size_t value_len)
712{
713#ifdef CONFIG_JFS_POSIX_ACL
714 struct posix_acl *acl;
715 int rc;
716
717 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
718 return -EPERM;
719
720 /*
721 * XATTR_NAME_ACL_ACCESS is tied to i_mode
722 */
723 if (strcmp(name, XATTR_NAME_ACL_ACCESS) == 0) {
724 acl = posix_acl_from_xattr(value, value_len);
725 if (IS_ERR(acl)) {
726 rc = PTR_ERR(acl);
727 printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
728 rc);
729 return rc;
730 }
731 if (acl) {
732 mode_t mode = inode->i_mode;
733 rc = posix_acl_equiv_mode(acl, &mode);
734 posix_acl_release(acl);
735 if (rc < 0) {
736 printk(KERN_ERR
737 "posix_acl_equiv_mode returned %d\n",
738 rc);
739 return rc;
740 }
741 inode->i_mode = mode;
742 mark_inode_dirty(inode);
743 }
744 /*
745 * We're changing the ACL. Get rid of the cached one
746 */
747 acl =JFS_IP(inode)->i_acl;
748 if (acl != JFS_ACL_NOT_CACHED)
749 posix_acl_release(acl);
750 JFS_IP(inode)->i_acl = JFS_ACL_NOT_CACHED;
751
752 return 0;
753 } else if (strcmp(name, XATTR_NAME_ACL_DEFAULT) == 0) {
754 acl = posix_acl_from_xattr(value, value_len);
755 if (IS_ERR(acl)) {
756 rc = PTR_ERR(acl);
757 printk(KERN_ERR "posix_acl_from_xattr returned %d\n",
758 rc);
759 return rc;
760 }
761 posix_acl_release(acl);
762
763 /*
764 * We're changing the default ACL. Get rid of the cached one
765 */
766 acl =JFS_IP(inode)->i_default_acl;
767 if (acl && (acl != JFS_ACL_NOT_CACHED))
768 posix_acl_release(acl);
769 JFS_IP(inode)->i_default_acl = JFS_ACL_NOT_CACHED;
770
771 return 0;
772 }
773#endif /* CONFIG_JFS_POSIX_ACL */
774 return -EOPNOTSUPP;
775}
776
777static int can_set_xattr(struct inode *inode, const char *name,
778 const void *value, size_t value_len)
779{
780 if (IS_RDONLY(inode))
781 return -EROFS;
782
783 if (IS_IMMUTABLE(inode) || IS_APPEND(inode) || S_ISLNK(inode->i_mode))
784 return -EPERM;
785
786 if(strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) == 0)
787 /*
788 * "system.*"
789 */
790 return can_set_system_xattr(inode, name, value, value_len);
791
792 if(strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) != 0)
793 return (capable(CAP_SYS_ADMIN) ? 0 : -EPERM);
794
795#ifdef CONFIG_JFS_SECURITY
796 if (strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN)
797 != 0)
798 return 0; /* Leave it to the security module */
799#endif
800
801 if((strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) != 0) &&
802 (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) != 0))
803 return -EOPNOTSUPP;
804
805 if (!S_ISREG(inode->i_mode) &&
806 (!S_ISDIR(inode->i_mode) || inode->i_mode &S_ISVTX))
807 return -EPERM;
808
809 return permission(inode, MAY_WRITE, NULL);
810}
811
812int __jfs_setxattr(struct inode *inode, const char *name, const void *value,
813 size_t value_len, int flags)
814{
815 struct jfs_ea_list *ealist;
816 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
817 struct ea_buffer ea_buf;
818 int old_ea_size = 0;
819 int xattr_size;
820 int new_size;
821 int namelen = strlen(name);
822 char *os2name = NULL;
823 int found = 0;
824 int rc;
825 int length;
826
827 if ((rc = can_set_xattr(inode, name, value, value_len)))
828 return rc;
829
830 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
831 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
832 GFP_KERNEL);
833 if (!os2name)
834 return -ENOMEM;
835 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
836 name = os2name;
837 namelen -= XATTR_OS2_PREFIX_LEN;
838 }
839
840 down_write(&JFS_IP(inode)->xattr_sem);
841
842 xattr_size = ea_get(inode, &ea_buf, 0);
843 if (xattr_size < 0) {
844 rc = xattr_size;
845 goto out;
846 }
847
848 again:
849 ealist = (struct jfs_ea_list *) ea_buf.xattr;
850 new_size = sizeof (struct jfs_ea_list);
851
852 if (xattr_size) {
853 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
854 ea = NEXT_EA(ea)) {
855 if ((namelen == ea->namelen) &&
856 (memcmp(name, ea->name, namelen) == 0)) {
857 found = 1;
858 if (flags & XATTR_CREATE) {
859 rc = -EEXIST;
860 goto release;
861 }
862 old_ea = ea;
863 old_ea_size = EA_SIZE(ea);
864 next_ea = NEXT_EA(ea);
865 } else
866 new_size += EA_SIZE(ea);
867 }
868 }
869
870 if (!found) {
871 if (flags & XATTR_REPLACE) {
872 rc = -ENODATA;
873 goto release;
874 }
875 if (value == NULL) {
876 rc = 0;
877 goto release;
878 }
879 }
880 if (value)
881 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
882
883 if (new_size > ea_buf.max_size) {
884 /*
885 * We need to allocate more space for merged ea list.
886 * We should only have loop to again: once.
887 */
888 ea_release(inode, &ea_buf);
889 xattr_size = ea_get(inode, &ea_buf, new_size);
890 if (xattr_size < 0) {
891 rc = xattr_size;
892 goto out;
893 }
894 goto again;
895 }
896
897 /* Remove old ea of the same name */
898 if (found) {
899 /* number of bytes following target EA */
900 length = (char *) END_EALIST(ealist) - (char *) next_ea;
901 if (length > 0)
902 memmove(old_ea, next_ea, length);
903 xattr_size -= old_ea_size;
904 }
905
906 /* Add new entry to the end */
907 if (value) {
908 if (xattr_size == 0)
909 /* Completely new ea list */
910 xattr_size = sizeof (struct jfs_ea_list);
911
912 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
913 ea->flag = 0;
914 ea->namelen = namelen;
915 ea->valuelen = (cpu_to_le16(value_len));
916 memcpy(ea->name, name, namelen);
917 ea->name[namelen] = 0;
918 if (value_len)
919 memcpy(&ea->name[namelen + 1], value, value_len);
920 xattr_size += EA_SIZE(ea);
921 }
922
923 /* DEBUG - If we did this right, these number match */
924 if (xattr_size != new_size) {
925 printk(KERN_ERR
926 "jfs_xsetattr: xattr_size = %d, new_size = %d\n",
927 xattr_size, new_size);
928
929 rc = -EINVAL;
930 goto release;
931 }
932
933 /*
934 * If we're left with an empty list, there's no ea
935 */
936 if (new_size == sizeof (struct jfs_ea_list))
937 new_size = 0;
938
939 ealist->size = cpu_to_le32(new_size);
940
941 rc = ea_put(inode, &ea_buf, new_size);
942
943 goto out;
944 release:
945 ea_release(inode, &ea_buf);
946 out:
947 up_write(&JFS_IP(inode)->xattr_sem);
948
949 if (os2name)
950 kfree(os2name);
951
952 return rc;
953}
954
955int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
956 size_t value_len, int flags)
957{
958 if (value == NULL) { /* empty EA, do not remove */
959 value = "";
960 value_len = 0;
961 }
962
963 return __jfs_setxattr(dentry->d_inode, name, value, value_len, flags);
964}
965
966static int can_get_xattr(struct inode *inode, const char *name)
967{
968#ifdef CONFIG_JFS_SECURITY
969 if(strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) == 0)
970 return 0;
971#endif
972
973 if(strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) == 0)
974 return (capable(CAP_SYS_ADMIN) ? 0 : -EPERM);
975
976 if(strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) == 0)
977 return 0;
978
979 return permission(inode, MAY_READ, NULL);
980}
981
982ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
983 size_t buf_size)
984{
985 struct jfs_ea_list *ealist;
986 struct jfs_ea *ea;
987 struct ea_buffer ea_buf;
988 int xattr_size;
989 ssize_t size;
990 int namelen = strlen(name);
991 char *os2name = NULL;
992 int rc;
993 char *value;
994
995 if ((rc = can_get_xattr(inode, name)))
996 return rc;
997
998 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
999 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
1000 GFP_KERNEL);
1001 if (!os2name)
1002 return -ENOMEM;
1003 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
1004 name = os2name;
1005 namelen -= XATTR_OS2_PREFIX_LEN;
1006 }
1007
1008 down_read(&JFS_IP(inode)->xattr_sem);
1009
1010 xattr_size = ea_get(inode, &ea_buf, 0);
1011
1012 if (xattr_size < 0) {
1013 size = xattr_size;
1014 goto out;
1015 }
1016
1017 if (xattr_size == 0)
1018 goto not_found;
1019
1020 ealist = (struct jfs_ea_list *) ea_buf.xattr;
1021
1022 /* Find the named attribute */
1023 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
1024 if ((namelen == ea->namelen) &&
1025 memcmp(name, ea->name, namelen) == 0) {
1026 /* Found it */
1027 size = le16_to_cpu(ea->valuelen);
1028 if (!data)
1029 goto release;
1030 else if (size > buf_size) {
1031 size = -ERANGE;
1032 goto release;
1033 }
1034 value = ((char *) &ea->name) + ea->namelen + 1;
1035 memcpy(data, value, size);
1036 goto release;
1037 }
1038 not_found:
1039 size = -ENODATA;
1040 release:
1041 ea_release(inode, &ea_buf);
1042 out:
1043 up_read(&JFS_IP(inode)->xattr_sem);
1044
1045 if (os2name)
1046 kfree(os2name);
1047
1048 return size;
1049}
1050
1051ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
1052 size_t buf_size)
1053{
1054 int err;
1055
1056 err = __jfs_getxattr(dentry->d_inode, name, data, buf_size);
1057
1058 return err;
1059}
1060
1061/*
1062 * No special permissions are needed to list attributes except for trusted.*
1063 */
1064static inline int can_list(struct jfs_ea *ea)
1065{
1066 return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
1067 XATTR_TRUSTED_PREFIX_LEN) ||
1068 capable(CAP_SYS_ADMIN));
1069}
1070
1071ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
1072{
1073 struct inode *inode = dentry->d_inode;
1074 char *buffer;
1075 ssize_t size = 0;
1076 int xattr_size;
1077 struct jfs_ea_list *ealist;
1078 struct jfs_ea *ea;
1079 struct ea_buffer ea_buf;
1080
1081 down_read(&JFS_IP(inode)->xattr_sem);
1082
1083 xattr_size = ea_get(inode, &ea_buf, 0);
1084 if (xattr_size < 0) {
1085 size = xattr_size;
1086 goto out;
1087 }
1088
1089 if (xattr_size == 0)
1090 goto release;
1091
1092 ealist = (struct jfs_ea_list *) ea_buf.xattr;
1093
1094 /* compute required size of list */
1095 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1096 if (can_list(ea))
1097 size += name_size(ea) + 1;
1098 }
1099
1100 if (!data)
1101 goto release;
1102
1103 if (size > buf_size) {
1104 size = -ERANGE;
1105 goto release;
1106 }
1107
1108 /* Copy attribute names to buffer */
1109 buffer = data;
1110 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1111 if (can_list(ea)) {
1112 int namelen = copy_name(buffer, ea);
1113 buffer += namelen + 1;
1114 }
1115 }
1116
1117 release:
1118 ea_release(inode, &ea_buf);
1119 out:
1120 up_read(&JFS_IP(inode)->xattr_sem);
1121 return size;
1122}
1123
1124int jfs_removexattr(struct dentry *dentry, const char *name)
1125{
1126 return __jfs_setxattr(dentry->d_inode, name, NULL, 0, XATTR_REPLACE);
1127}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-07 03:53:42 -0500