1 /*
2 * Copyright (C) International Business Machines Corp., 2000-2003
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 "jfs_incore.h"
23 #include "jfs_superblock.h"
24 #include "jfs_dmap.h"
25 #include "jfs_debug.h"
26 #include "jfs_dinode.h"
27 #include "jfs_extent.h"
28 #include "jfs_metapage.h"
29 #include "jfs_xattr.h"
30
31 /*
32 * jfs_xattr.c: extended attribute service
33 *
34 * Overall design --
35 *
36 * Format:
37 *
38 * Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
39 * value) and a variable (0 or more) number of extended attribute
40 * entries. Each extended attribute entry (jfs_ea) is a <name,value> double
41 * where <name> is constructed from a null-terminated ascii string
42 * (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
43 * (1 ... 65535 bytes). The in-memory format is
44 *
45 * 0 1 2 4 4 + namelen + 1
46 * +-------+--------+--------+----------------+-------------------+
47 * | Flags | Name | Value | Name String \0 | Data . . . . |
48 * | | Length | Length | | |
49 * +-------+--------+--------+----------------+-------------------+
50 *
51 * A jfs_ea_list then is structured as
52 *
53 * 0 4 4 + EA_SIZE(ea1)
54 * +------------+-------------------+--------------------+-----
55 * | Overall EA | First FEA Element | Second FEA Element | .....
56 * | List Size | | |
57 * +------------+-------------------+--------------------+-----
58 *
59 * On-disk:
60 *
61 * FEALISTs are stored on disk using blocks allocated by dbAlloc() and
62 * written directly. An EA list may be in-lined in the inode if there is
63 * sufficient room available.
64 */
65
66 struct ea_buffer {
67 int flag; /* Indicates what storage xattr points to */
68 int max_size; /* largest xattr that fits in current buffer */
69 dxd_t new_ea; /* dxd to replace ea when modifying xattr */
70 struct metapage *mp; /* metapage containing ea list */
71 struct jfs_ea_list *xattr; /* buffer containing ea list */
72 };
73
74 /*
75 * ea_buffer.flag values
76 */
77 #define EA_INLINE 0x0001
78 #define EA_EXTENT 0x0002
79 #define EA_NEW 0x0004
80 #define EA_MALLOC 0x0008
81
82 /* Namespaces */
83 #define XATTR_SYSTEM_PREFIX "system."
84 #define XATTR_SYSTEM_PREFIX_LEN (sizeof (XATTR_SYSTEM_PREFIX) - 1)
85
86 #define XATTR_USER_PREFIX "user."
87 #define XATTR_USER_PREFIX_LEN (sizeof (XATTR_USER_PREFIX) - 1)
88
89 #define XATTR_OS2_PREFIX "os2."
90 #define XATTR_OS2_PREFIX_LEN (sizeof (XATTR_OS2_PREFIX) - 1)
91
92 /*
93 * These three routines are used to recognize on-disk extended attributes
94 * that are in a recognized namespace. If the attribute is not recognized,
95 * "os2." is prepended to the name
96 */
is_os2_xattr(struct jfs_ea * ea)97 static inline int is_os2_xattr(struct jfs_ea *ea)
98 {
99 /*
100 * Check for "system."
101 */
102 if ((ea->namelen >= XATTR_SYSTEM_PREFIX_LEN) &&
103 !strncmp(ea->name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
104 return FALSE;
105 /*
106 * Check for "user."
107 */
108 if ((ea->namelen >= XATTR_USER_PREFIX_LEN) &&
109 !strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
110 return FALSE;
111 /*
112 * Add any other valid namespace prefixes here
113 */
114
115 /*
116 * We assume it's OS/2's flat namespace
117 */
118 return TRUE;
119 }
120
name_size(struct jfs_ea * ea)121 static inline int name_size(struct jfs_ea *ea)
122 {
123 if (is_os2_xattr(ea))
124 return ea->namelen + XATTR_OS2_PREFIX_LEN;
125 else
126 return ea->namelen;
127 }
128
copy_name(char * buffer,struct jfs_ea * ea)129 static inline int copy_name(char *buffer, struct jfs_ea *ea)
130 {
131 int len = ea->namelen;
132
133 if (is_os2_xattr(ea)) {
134 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
135 buffer += XATTR_OS2_PREFIX_LEN;
136 len += XATTR_OS2_PREFIX_LEN;
137 }
138 memcpy(buffer, ea->name, ea->namelen);
139 buffer[ea->namelen] = 0;
140
141 return len;
142 }
143
144 /* Forward references */
145 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
146
147 /*
148 * NAME: ea_write_inline
149 *
150 * FUNCTION: Attempt to write an EA inline if area is available
151 *
152 * PRE CONDITIONS:
153 * Already verified that the specified EA is small enough to fit inline
154 *
155 * PARAMETERS:
156 * ip - Inode pointer
157 * ealist - EA list pointer
158 * size - size of ealist in bytes
159 * ea - dxd_t structure to be filled in with necessary EA information
160 * if we successfully copy the EA inline
161 *
162 * NOTES:
163 * Checks if the inode's inline area is available. If so, copies EA inline
164 * and sets <ea> fields appropriately. Otherwise, returns failure, EA will
165 * have to be put into an extent.
166 *
167 * RETURNS: 0 for successful copy to inline area; -1 if area not available
168 */
ea_write_inline(struct inode * ip,struct jfs_ea_list * ealist,int size,dxd_t * ea)169 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
170 int size, dxd_t * ea)
171 {
172 struct jfs_inode_info *ji = JFS_IP(ip);
173
174 /*
175 * Make sure we have an EA -- the NULL EA list is valid, but you
176 * can't copy it!
177 */
178 if (ealist && size > sizeof (struct jfs_ea_list)) {
179 assert(size <= sizeof (ji->i_inline_ea));
180
181 /*
182 * See if the space is available or if it is already being
183 * used for an inline EA.
184 */
185 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
186 return -EPERM;
187
188 DXDsize(ea, size);
189 DXDlength(ea, 0);
190 DXDaddress(ea, 0);
191 memcpy(ji->i_inline_ea, ealist, size);
192 ea->flag = DXD_INLINE;
193 ji->mode2 &= ~INLINEEA;
194 } else {
195 ea->flag = 0;
196 DXDsize(ea, 0);
197 DXDlength(ea, 0);
198 DXDaddress(ea, 0);
199
200 /* Free up INLINE area */
201 if (ji->ea.flag & DXD_INLINE)
202 ji->mode2 |= INLINEEA;
203 }
204
205 mark_inode_dirty(ip);
206 return 0;
207 }
208
209 /*
210 * NAME: ea_write
211 *
212 * FUNCTION: Write an EA for an inode
213 *
214 * PRE CONDITIONS: EA has been verified
215 *
216 * PARAMETERS:
217 * ip - Inode pointer
218 * ealist - EA list pointer
219 * size - size of ealist in bytes
220 * ea - dxd_t structure to be filled in appropriately with where the
221 * EA was copied
222 *
223 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
224 * extent and synchronously writes it to those blocks.
225 *
226 * RETURNS: 0 for success; Anything else indicates failure
227 */
ea_write(struct inode * ip,struct jfs_ea_list * ealist,int size,dxd_t * ea)228 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
229 dxd_t * ea)
230 {
231 struct super_block *sb = ip->i_sb;
232 struct jfs_inode_info *ji = JFS_IP(ip);
233 struct jfs_sb_info *sbi = JFS_SBI(sb);
234 int nblocks;
235 s64 blkno;
236 int rc = 0, i;
237 char *cp;
238 s32 nbytes, nb;
239 s32 bytes_to_write;
240 struct metapage *mp;
241
242 /*
243 * Quick check to see if this is an in-linable EA. Short EAs
244 * and empty EAs are all in-linable, provided the space exists.
245 */
246 if (!ealist || size <= sizeof (ji->i_inline_ea)) {
247 if (!ea_write_inline(ip, ealist, size, ea))
248 return 0;
249 }
250
251 /* figure out how many blocks we need */
252 nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
253
254 rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
255 if (rc)
256 return rc;
257
258 /*
259 * Now have nblocks worth of storage to stuff into the FEALIST.
260 * loop over the FEALIST copying data into the buffer one page at
261 * a time.
262 */
263 cp = (char *) ealist;
264 nbytes = size;
265 for (i = 0; i < nblocks; i += sbi->nbperpage) {
266 /*
267 * Determine how many bytes for this request, and round up to
268 * the nearest aggregate block size
269 */
270 nb = min(PSIZE, nbytes);
271 bytes_to_write =
272 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
273 << sb->s_blocksize_bits;
274
275 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
276 rc = -EIO;
277 goto failed;
278 }
279
280 memcpy(mp->data, cp, nb);
281
282 /*
283 * We really need a way to propagate errors for
284 * forced writes like this one. --hch
285 *
286 * (__write_metapage => release_metapage => flush_metapage)
287 */
288 #ifdef _JFS_FIXME
289 if ((rc = flush_metapage(mp))) {
290 /*
291 * the write failed -- this means that the buffer
292 * is still assigned and the blocks are not being
293 * used. this seems like the best error recovery
294 * we can get ...
295 */
296 goto failed;
297 }
298 #else
299 flush_metapage(mp);
300 #endif
301
302 cp += PSIZE;
303 nbytes -= nb;
304 }
305
306 ea->flag = DXD_EXTENT;
307 DXDsize(ea, le32_to_cpu(ealist->size));
308 DXDlength(ea, nblocks);
309 DXDaddress(ea, blkno);
310
311 /* Free up INLINE area */
312 if (ji->ea.flag & DXD_INLINE)
313 ji->mode2 |= INLINEEA;
314
315 return 0;
316
317 failed:
318 dbFree(ip, blkno, nblocks);
319 return rc;
320 }
321
322 /*
323 * NAME: ea_read_inline
324 *
325 * FUNCTION: Read an inlined EA into user's buffer
326 *
327 * PARAMETERS:
328 * ip - Inode pointer
329 * ealist - Pointer to buffer to fill in with EA
330 *
331 * RETURNS: 0
332 */
ea_read_inline(struct inode * ip,struct jfs_ea_list * ealist)333 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
334 {
335 struct jfs_inode_info *ji = JFS_IP(ip);
336 int ea_size = sizeDXD(&ji->ea);
337
338 if (ea_size == 0) {
339 ealist->size = 0;
340 return 0;
341 }
342
343 /* Sanity Check */
344 if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
345 return -EIO;
346 if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
347 != ea_size)
348 return -EIO;
349
350 memcpy(ealist, ji->i_inline_ea, ea_size);
351 return 0;
352 }
353
354 /*
355 * NAME: ea_read
356 *
357 * FUNCTION: copy EA data into user's buffer
358 *
359 * PARAMETERS:
360 * ip - Inode pointer
361 * ealist - Pointer to buffer to fill in with EA
362 *
363 * NOTES: If EA is inline calls ea_read_inline() to copy EA.
364 *
365 * RETURNS: 0 for success; other indicates failure
366 */
ea_read(struct inode * ip,struct jfs_ea_list * ealist)367 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
368 {
369 struct super_block *sb = ip->i_sb;
370 struct jfs_inode_info *ji = JFS_IP(ip);
371 struct jfs_sb_info *sbi = JFS_SBI(sb);
372 int nblocks;
373 s64 blkno;
374 char *cp = (char *) ealist;
375 int i;
376 int nbytes, nb;
377 s32 bytes_to_read;
378 struct metapage *mp;
379
380 /* quick check for in-line EA */
381 if (ji->ea.flag & DXD_INLINE)
382 return ea_read_inline(ip, ealist);
383
384 nbytes = sizeDXD(&ji->ea);
385 if (!nbytes) {
386 jfs_error(sb, "ea_read: nbytes is 0");
387 return -EIO;
388 }
389
390 /*
391 * Figure out how many blocks were allocated when this EA list was
392 * originally written to disk.
393 */
394 nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
395 blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
396
397 /*
398 * I have found the disk blocks which were originally used to store
399 * the FEALIST. now i loop over each contiguous block copying the
400 * data into the buffer.
401 */
402 for (i = 0; i < nblocks; i += sbi->nbperpage) {
403 /*
404 * Determine how many bytes for this request, and round up to
405 * the nearest aggregate block size
406 */
407 nb = min(PSIZE, nbytes);
408 bytes_to_read =
409 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
410 << sb->s_blocksize_bits;
411
412 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
413 return -EIO;
414
415 memcpy(cp, mp->data, nb);
416 release_metapage(mp);
417
418 cp += PSIZE;
419 nbytes -= nb;
420 }
421
422 return 0;
423 }
424
425 /*
426 * NAME: ea_get
427 *
428 * FUNCTION: Returns buffer containing existing extended attributes.
429 * The size of the buffer will be the larger of the existing
430 * attributes size, or min_size.
431 *
432 * The buffer, which may be inlined in the inode or in the
433 * page cache must be release by calling ea_release or ea_put
434 *
435 * PARAMETERS:
436 * inode - Inode pointer
437 * ea_buf - Structure to be populated with ealist and its metadata
438 * min_size- minimum size of buffer to be returned
439 *
440 * RETURNS: 0 for success; Other indicates failure
441 */
ea_get(struct inode * inode,struct ea_buffer * ea_buf,int min_size)442 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
443 {
444 struct jfs_inode_info *ji = JFS_IP(inode);
445 struct super_block *sb = inode->i_sb;
446 int size;
447 int ea_size = sizeDXD(&ji->ea);
448 int blocks_needed, current_blocks;
449 s64 blkno;
450 int rc;
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 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
521 &blkno);
522 if (rc)
523 return rc;
524
525 DXDlength(&ea_buf->new_ea, blocks_needed);
526 DXDaddress(&ea_buf->new_ea, blkno);
527 ea_buf->new_ea.flag = DXD_EXTENT;
528 DXDsize(&ea_buf->new_ea, min_size);
529
530 ea_buf->flag = EA_EXTENT | EA_NEW;
531
532 ea_buf->mp = get_metapage(inode, blkno,
533 blocks_needed << sb->s_blocksize_bits,
534 1);
535 if (ea_buf->mp == NULL) {
536 dbFree(inode, blkno, (s64) blocks_needed);
537 return -EIO;
538 }
539 ea_buf->xattr = ea_buf->mp->data;
540 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
541 ~(sb->s_blocksize - 1);
542 if (ea_size == 0)
543 return 0;
544 if ((rc = ea_read(inode, ea_buf->xattr))) {
545 discard_metapage(ea_buf->mp);
546 dbFree(inode, blkno, (s64) blocks_needed);
547 return rc;
548 }
549 goto size_check;
550 }
551 ea_buf->flag = EA_EXTENT;
552 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
553 lengthDXD(&ji->ea) << sb->s_blocksize_bits,
554 1);
555 if (ea_buf->mp == NULL)
556 return -EIO;
557 ea_buf->xattr = ea_buf->mp->data;
558 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
559 ~(sb->s_blocksize - 1);
560
561 size_check:
562 if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
563 printk(KERN_ERR "ea_get: invalid extended attribute\n");
564 dump_mem("xattr", ea_buf->xattr, ea_size);
565 ea_release(inode, ea_buf);
566 return -EIO;
567 }
568
569 return ea_size;
570 }
571
ea_release(struct inode * inode,struct ea_buffer * ea_buf)572 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
573 {
574 if (ea_buf->flag & EA_MALLOC)
575 kfree(ea_buf->xattr);
576 else if (ea_buf->flag & EA_EXTENT) {
577 assert(ea_buf->mp);
578 release_metapage(ea_buf->mp);
579
580 if (ea_buf->flag & EA_NEW)
581 dbFree(inode, addressDXD(&ea_buf->new_ea),
582 lengthDXD(&ea_buf->new_ea));
583 }
584 }
585
ea_put(struct inode * inode,struct ea_buffer * ea_buf,int new_size)586 static int ea_put(struct inode *inode, struct ea_buffer *ea_buf, int new_size)
587 {
588 struct jfs_inode_info *ji = JFS_IP(inode);
589 unsigned long old_blocks, new_blocks;
590 int rc = 0;
591 tid_t tid;
592
593 if (new_size == 0) {
594 ea_release(inode, ea_buf);
595 ea_buf = 0;
596 } else if (ea_buf->flag & EA_INLINE) {
597 assert(new_size <= sizeof (ji->i_inline_ea));
598 ji->mode2 &= ~INLINEEA;
599 ea_buf->new_ea.flag = DXD_INLINE;
600 DXDsize(&ea_buf->new_ea, new_size);
601 DXDaddress(&ea_buf->new_ea, 0);
602 DXDlength(&ea_buf->new_ea, 0);
603 } else if (ea_buf->flag & EA_MALLOC) {
604 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
605 kfree(ea_buf->xattr);
606 } else if (ea_buf->flag & EA_NEW) {
607 /* We have already allocated a new dxd */
608 flush_metapage(ea_buf->mp);
609 } else {
610 /* ->xattr must point to original ea's metapage */
611 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
612 discard_metapage(ea_buf->mp);
613 }
614 if (rc)
615 return rc;
616
617 tid = txBegin(inode->i_sb, 0);
618 down(&ji->commit_sem);
619
620 old_blocks = new_blocks = 0;
621
622 if (ji->ea.flag & DXD_EXTENT) {
623 invalidate_dxd_metapages(inode, ji->ea);
624 old_blocks = lengthDXD(&ji->ea);
625 }
626
627 if (ea_buf) {
628 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
629 if (ea_buf->new_ea.flag & DXD_EXTENT) {
630 new_blocks = lengthDXD(&ea_buf->new_ea);
631 if (ji->ea.flag & DXD_INLINE)
632 ji->mode2 |= INLINEEA;
633 }
634 ji->ea = ea_buf->new_ea;
635 } else {
636 txEA(tid, inode, &ji->ea, 0);
637 if (ji->ea.flag & DXD_INLINE)
638 ji->mode2 |= INLINEEA;
639 ji->ea.flag = 0;
640 ji->ea.size = 0;
641 }
642
643 inode->i_blocks += LBLK2PBLK(inode->i_sb, new_blocks - old_blocks);
644 rc = txCommit(tid, 1, &inode, 0);
645 txEnd(tid);
646 up(&ji->commit_sem);
647
648 return rc;
649 }
650
can_set_xattr(struct inode * inode,const char * name,void * value,size_t value_len)651 static int can_set_xattr(struct inode *inode, const char *name,
652 void *value, size_t value_len)
653 {
654 if (IS_RDONLY(inode))
655 return -EROFS;
656
657 if (IS_IMMUTABLE(inode) || IS_APPEND(inode) || S_ISLNK(inode->i_mode))
658 return -EPERM;
659
660 if((strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) != 0) &&
661 (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) != 0))
662 return -EOPNOTSUPP;
663
664 if (!S_ISREG(inode->i_mode) &&
665 (!S_ISDIR(inode->i_mode) || inode->i_mode &S_ISVTX))
666 return -EPERM;
667
668 return permission(inode, MAY_WRITE);
669 }
670
__jfs_setxattr(struct inode * inode,const char * name,void * value,size_t value_len,int flags)671 int __jfs_setxattr(struct inode *inode, const char *name, void *value,
672 size_t value_len, int flags)
673 {
674 struct jfs_ea_list *ealist;
675 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
676 struct ea_buffer ea_buf;
677 int old_ea_size = 0;
678 int xattr_size;
679 int new_size;
680 int namelen = strlen(name);
681 char *os2name = NULL;
682 int found = 0;
683 int rc;
684 int length;
685
686 if ((rc = can_set_xattr(inode, name, value, value_len)))
687 return rc;
688
689 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
690 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
691 GFP_KERNEL);
692 if (!os2name)
693 return -ENOMEM;
694 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
695 name = os2name;
696 namelen -= XATTR_OS2_PREFIX_LEN;
697 }
698
699 xattr_size = ea_get(inode, &ea_buf, 0);
700 if (xattr_size < 0) {
701 rc = xattr_size;
702 goto out;
703 }
704
705 again:
706 ealist = (struct jfs_ea_list *) ea_buf.xattr;
707 new_size = sizeof (struct jfs_ea_list);
708
709 if (xattr_size) {
710 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
711 ea = NEXT_EA(ea)) {
712 if ((namelen == ea->namelen) &&
713 (memcmp(name, ea->name, namelen) == 0)) {
714 found = 1;
715 if (flags & XATTR_CREATE) {
716 rc = -EEXIST;
717 goto release;
718 }
719 old_ea = ea;
720 old_ea_size = EA_SIZE(ea);
721 next_ea = NEXT_EA(ea);
722 } else
723 new_size += EA_SIZE(ea);
724 }
725 }
726
727 if (!found) {
728 if (flags & XATTR_REPLACE) {
729 rc = -ENODATA;
730 goto release;
731 }
732 if (value == NULL) {
733 rc = 0;
734 goto release;
735 }
736 }
737 if (value)
738 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
739
740 if (new_size > ea_buf.max_size) {
741 /*
742 * We need to allocate more space for merged ea list.
743 * We should only have loop to again: once.
744 */
745 ea_release(inode, &ea_buf);
746 xattr_size = ea_get(inode, &ea_buf, new_size);
747 if (xattr_size < 0) {
748 rc = xattr_size;
749 goto out;
750 }
751 goto again;
752 }
753
754 /* Remove old ea of the same name */
755 if (found) {
756 /* number of bytes following target EA */
757 length = (char *) END_EALIST(ealist) - (char *) next_ea;
758 if (length > 0)
759 memmove(old_ea, next_ea, length);
760 xattr_size -= old_ea_size;
761 }
762
763 /* Add new entry to the end */
764 if (value) {
765 if (xattr_size == 0)
766 /* Completely new ea list */
767 xattr_size = sizeof (struct jfs_ea_list);
768
769 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
770 ea->flag = 0;
771 ea->namelen = namelen;
772 ea->valuelen = (cpu_to_le16(value_len));
773 memcpy(ea->name, name, namelen);
774 ea->name[namelen] = 0;
775 if (value_len)
776 memcpy(&ea->name[namelen + 1], value, value_len);
777 xattr_size += EA_SIZE(ea);
778 }
779
780 /* DEBUG - If we did this right, these number match */
781 if (xattr_size != new_size) {
782 printk(KERN_ERR
783 "jfs_xsetattr: xattr_size = %d, new_size = %d\n",
784 xattr_size, new_size);
785
786 rc = -EINVAL;
787 goto release;
788 }
789
790 /*
791 * If we're left with an empty list, there's no ea
792 */
793 if (new_size == sizeof (struct jfs_ea_list))
794 new_size = 0;
795
796 ealist->size = cpu_to_le32(new_size);
797
798 rc = ea_put(inode, &ea_buf, new_size);
799
800 goto out;
801 release:
802 ea_release(inode, &ea_buf);
803 out:
804 if (os2name)
805 kfree(os2name);
806
807 return rc;
808 }
809
jfs_setxattr(struct dentry * dentry,const char * name,void * value,size_t value_len,int flags)810 int jfs_setxattr(struct dentry *dentry, const char *name, void *value,
811 size_t value_len, int flags)
812 {
813 if (value == NULL) { /* empty EA, do not remove */
814 value = "";
815 value_len = 0;
816 }
817
818 return __jfs_setxattr(dentry->d_inode, name, value, value_len, flags);
819 }
820
can_get_xattr(struct inode * inode,const char * name)821 static inline int can_get_xattr(struct inode *inode, const char *name)
822 {
823 if(strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) == 0)
824 return 0;
825 return permission(inode, MAY_READ);
826 }
827
__jfs_getxattr(struct inode * inode,const char * name,void * data,size_t buf_size)828 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
829 size_t buf_size)
830 {
831 struct jfs_ea_list *ealist;
832 struct jfs_ea *ea;
833 struct ea_buffer ea_buf;
834 int xattr_size;
835 ssize_t size;
836 int namelen = strlen(name);
837 char *os2name = NULL;
838 int rc;
839 char *value;
840
841 if ((rc = can_get_xattr(inode, name)))
842 return rc;
843
844 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
845 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
846 GFP_KERNEL);
847 if (!os2name)
848 return -ENOMEM;
849 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
850 name = os2name;
851 namelen -= XATTR_OS2_PREFIX_LEN;
852 }
853
854 xattr_size = ea_get(inode, &ea_buf, 0);
855 if (xattr_size < 0) {
856 size = xattr_size;
857 goto out;
858 }
859
860 if (xattr_size == 0)
861 goto not_found;
862
863 ealist = (struct jfs_ea_list *) ea_buf.xattr;
864
865 /* Find the named attribute */
866 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
867 if ((namelen == ea->namelen) &&
868 memcmp(name, ea->name, namelen) == 0) {
869 /* Found it */
870 size = le16_to_cpu(ea->valuelen);
871 if (!data)
872 goto release;
873 else if (size > buf_size) {
874 size = -ERANGE;
875 goto release;
876 }
877 value = ((char *) &ea->name) + ea->namelen + 1;
878 memcpy(data, value, size);
879 goto release;
880 }
881 not_found:
882 size = -ENODATA;
883 release:
884 ea_release(inode, &ea_buf);
885 out:
886 if (os2name)
887 kfree(os2name);
888
889 return size;
890 }
891
jfs_getxattr(struct dentry * dentry,const char * name,void * data,size_t buf_size)892 ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
893 size_t buf_size)
894 {
895 return __jfs_getxattr(dentry->d_inode, name, data, buf_size);
896 }
897
jfs_listxattr(struct dentry * dentry,char * data,size_t buf_size)898 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
899 {
900 struct inode *inode = dentry->d_inode;
901 char *buffer;
902 ssize_t size = 0;
903 int xattr_size;
904 struct jfs_ea_list *ealist;
905 struct jfs_ea *ea;
906 struct ea_buffer ea_buf;
907
908 xattr_size = ea_get(inode, &ea_buf, 0);
909 if (xattr_size < 0) {
910 size = xattr_size;
911 goto out;
912 }
913
914 if (xattr_size == 0)
915 goto release;
916
917 ealist = (struct jfs_ea_list *) ea_buf.xattr;
918
919 /* compute required size of list */
920 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
921 size += name_size(ea) + 1;
922
923 if (!data)
924 goto release;
925
926 if (size > buf_size) {
927 size = -ERANGE;
928 goto release;
929 }
930
931 /* Copy attribute names to buffer */
932 buffer = data;
933 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
934 int namelen = copy_name(buffer, ea);
935 buffer += namelen + 1;
936 }
937
938 release:
939 ea_release(inode, &ea_buf);
940 out:
941 return size;
942 }
943
jfs_removexattr(struct dentry * dentry,const char * name)944 int jfs_removexattr(struct dentry *dentry, const char *name)
945 {
946 return __jfs_setxattr(dentry->d_inode, name, 0, 0, XATTR_REPLACE);
947 }
948