1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) International Business Machines Corp., 2000-2004
4 * Copyright (C) Christoph Hellwig, 2002
5 */
6
7 #include <linux/capability.h>
8 #include <linux/fs.h>
9 #include <linux/xattr.h>
10 #include <linux/posix_acl_xattr.h>
11 #include <linux/slab.h>
12 #include <linux/quotaops.h>
13 #include <linux/security.h>
14 #include "jfs_incore.h"
15 #include "jfs_superblock.h"
16 #include "jfs_dmap.h"
17 #include "jfs_debug.h"
18 #include "jfs_dinode.h"
19 #include "jfs_extent.h"
20 #include "jfs_metapage.h"
21 #include "jfs_xattr.h"
22 #include "jfs_acl.h"
23
24 /*
25 * jfs_xattr.c: extended attribute service
26 *
27 * Overall design --
28 *
29 * Format:
30 *
31 * Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
32 * value) and a variable (0 or more) number of extended attribute
33 * entries. Each extended attribute entry (jfs_ea) is a <name,value> double
34 * where <name> is constructed from a null-terminated ascii string
35 * (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
36 * (1 ... 65535 bytes). The in-memory format is
37 *
38 * 0 1 2 4 4 + namelen + 1
39 * +-------+--------+--------+----------------+-------------------+
40 * | Flags | Name | Value | Name String \0 | Data . . . . |
41 * | | Length | Length | | |
42 * +-------+--------+--------+----------------+-------------------+
43 *
44 * A jfs_ea_list then is structured as
45 *
46 * 0 4 4 + EA_SIZE(ea1)
47 * +------------+-------------------+--------------------+-----
48 * | Overall EA | First FEA Element | Second FEA Element | .....
49 * | List Size | | |
50 * +------------+-------------------+--------------------+-----
51 *
52 * On-disk:
53 *
54 * FEALISTs are stored on disk using blocks allocated by dbAlloc() and
55 * written directly. An EA list may be in-lined in the inode if there is
56 * sufficient room available.
57 */
58
59 struct ea_buffer {
60 int flag; /* Indicates what storage xattr points to */
61 int max_size; /* largest xattr that fits in current buffer */
62 dxd_t new_ea; /* dxd to replace ea when modifying xattr */
63 struct metapage *mp; /* metapage containing ea list */
64 struct jfs_ea_list *xattr; /* buffer containing ea list */
65 };
66
67 /*
68 * ea_buffer.flag values
69 */
70 #define EA_INLINE 0x0001
71 #define EA_EXTENT 0x0002
72 #define EA_NEW 0x0004
73 #define EA_MALLOC 0x0008
74
75
76 /*
77 * Mapping of on-disk attribute names: for on-disk attribute names with an
78 * unknown prefix (not "system.", "user.", "security.", or "trusted."), the
79 * prefix "os2." is prepended. On the way back to disk, "os2." prefixes are
80 * stripped and we make sure that the remaining name does not start with one
81 * of the know prefixes.
82 */
83
84 static int is_known_namespace(const char *name)
85 {
86 if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
87 strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
88 strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
89 strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
90 return false;
91
92 return true;
93 }
94
95 static inline int name_size(struct jfs_ea *ea)
96 {
97 if (is_known_namespace(ea->name))
98 return ea->namelen;
99 else
100 return ea->namelen + XATTR_OS2_PREFIX_LEN;
101 }
102
103 static inline int copy_name(char *buffer, struct jfs_ea *ea)
104 {
105 int len = ea->namelen;
106
107 if (!is_known_namespace(ea->name)) {
108 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
109 buffer += XATTR_OS2_PREFIX_LEN;
110 len += XATTR_OS2_PREFIX_LEN;
111 }
112 memcpy(buffer, ea->name, ea->namelen);
113 buffer[ea->namelen] = 0;
114
115 return len;
116 }
117
118 /* Forward references */
119 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
120
121 /*
122 * NAME: ea_write_inline
123 *
124 * FUNCTION: Attempt to write an EA inline if area is available
125 *
126 * PRE CONDITIONS:
127 * Already verified that the specified EA is small enough to fit inline
128 *
129 * PARAMETERS:
130 * ip - Inode pointer
131 * ealist - EA list pointer
132 * size - size of ealist in bytes
133 * ea - dxd_t structure to be filled in with necessary EA information
134 * if we successfully copy the EA inline
135 *
136 * NOTES:
137 * Checks if the inode's inline area is available. If so, copies EA inline
138 * and sets <ea> fields appropriately. Otherwise, returns failure, EA will
139 * have to be put into an extent.
140 *
141 * RETURNS: 0 for successful copy to inline area; -1 if area not available
142 */
143 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
144 int size, dxd_t * ea)
145 {
146 struct jfs_inode_info *ji = JFS_IP(ip);
147
148 /*
149 * Make sure we have an EA -- the NULL EA list is valid, but you
150 * can't copy it!
151 */
152 if (ealist && size > sizeof (struct jfs_ea_list)) {
153 assert(size <= sizeof (ji->i_inline_ea));
154
155 /*
156 * See if the space is available or if it is already being
157 * used for an inline EA.
158 */
159 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
160 return -EPERM;
161
162 DXDsize(ea, size);
163 DXDlength(ea, 0);
164 DXDaddress(ea, 0);
165 memcpy(ji->i_inline_ea, ealist, size);
166 ea->flag = DXD_INLINE;
167 ji->mode2 &= ~INLINEEA;
168 } else {
169 ea->flag = 0;
170 DXDsize(ea, 0);
171 DXDlength(ea, 0);
172 DXDaddress(ea, 0);
173
174 /* Free up INLINE area */
175 if (ji->ea.flag & DXD_INLINE)
176 ji->mode2 |= INLINEEA;
177 }
178
179 return 0;
180 }
181
182 /*
183 * NAME: ea_write
184 *
185 * FUNCTION: Write an EA for an inode
186 *
187 * PRE CONDITIONS: EA has been verified
188 *
189 * PARAMETERS:
190 * ip - Inode pointer
191 * ealist - EA list pointer
192 * size - size of ealist in bytes
193 * ea - dxd_t structure to be filled in appropriately with where the
194 * EA was copied
195 *
196 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
197 * extent and synchronously writes it to those blocks.
198 *
199 * RETURNS: 0 for success; Anything else indicates failure
200 */
201 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
202 dxd_t * ea)
203 {
204 struct super_block *sb = ip->i_sb;
205 struct jfs_inode_info *ji = JFS_IP(ip);
206 struct jfs_sb_info *sbi = JFS_SBI(sb);
207 int nblocks;
208 s64 blkno;
209 int rc = 0, i;
210 char *cp;
211 s32 nbytes, nb;
212 s32 bytes_to_write;
213 struct metapage *mp;
214
215 /*
216 * Quick check to see if this is an in-linable EA. Short EAs
217 * and empty EAs are all in-linable, provided the space exists.
218 */
219 if (!ealist || size <= sizeof (ji->i_inline_ea)) {
220 if (!ea_write_inline(ip, ealist, size, ea))
221 return 0;
222 }
223
224 /* figure out how many blocks we need */
225 nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
226
227 /* Allocate new blocks to quota. */
228 rc = dquot_alloc_block(ip, nblocks);
229 if (rc)
230 return rc;
231
232 rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
233 if (rc) {
234 /*Rollback quota allocation. */
235 dquot_free_block(ip, nblocks);
236 return rc;
237 }
238
239 /*
240 * Now have nblocks worth of storage to stuff into the FEALIST.
241 * loop over the FEALIST copying data into the buffer one page at
242 * a time.
243 */
244 cp = (char *) ealist;
245 nbytes = size;
246 for (i = 0; i < nblocks; i += sbi->nbperpage) {
247 /*
248 * Determine how many bytes for this request, and round up to
249 * the nearest aggregate block size
250 */
251 nb = min(PSIZE, nbytes);
252 bytes_to_write =
253 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
254 << sb->s_blocksize_bits;
255
256 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
257 rc = -EIO;
258 goto failed;
259 }
260
261 memcpy(mp->data, cp, nb);
262
263 /*
264 * We really need a way to propagate errors for
265 * forced writes like this one. --hch
266 *
267 * (__write_metapage => release_metapage => flush_metapage)
268 */
269 #ifdef _JFS_FIXME
270 if ((rc = flush_metapage(mp))) {
271 /*
272 * the write failed -- this means that the buffer
273 * is still assigned and the blocks are not being
274 * used. this seems like the best error recovery
275 * we can get ...
276 */
277 goto failed;
278 }
279 #else
280 flush_metapage(mp);
281 #endif
282
283 cp += PSIZE;
284 nbytes -= nb;
285 }
286
287 ea->flag = DXD_EXTENT;
288 DXDsize(ea, le32_to_cpu(ealist->size));
289 DXDlength(ea, nblocks);
290 DXDaddress(ea, blkno);
291
292 /* Free up INLINE area */
293 if (ji->ea.flag & DXD_INLINE)
294 ji->mode2 |= INLINEEA;
295
296 return 0;
297
298 failed:
299 /* Rollback quota allocation. */
300 dquot_free_block(ip, nblocks);
301
302 dbFree(ip, blkno, nblocks);
303 return rc;
304 }
305
306 /*
307 * NAME: ea_read_inline
308 *
309 * FUNCTION: Read an inlined EA into user's buffer
310 *
311 * PARAMETERS:
312 * ip - Inode pointer
313 * ealist - Pointer to buffer to fill in with EA
314 *
315 * RETURNS: 0
316 */
317 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
318 {
319 struct jfs_inode_info *ji = JFS_IP(ip);
320 int ea_size = sizeDXD(&ji->ea);
321
322 if (ea_size == 0) {
323 ealist->size = 0;
324 return 0;
325 }
326
327 /* Sanity Check */
328 if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
329 return -EIO;
330 if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
331 != ea_size)
332 return -EIO;
333
334 memcpy(ealist, ji->i_inline_ea, ea_size);
335 return 0;
336 }
337
338 /*
339 * NAME: ea_read
340 *
341 * FUNCTION: copy EA data into user's buffer
342 *
343 * PARAMETERS:
344 * ip - Inode pointer
345 * ealist - Pointer to buffer to fill in with EA
346 *
347 * NOTES: If EA is inline calls ea_read_inline() to copy EA.
348 *
349 * RETURNS: 0 for success; other indicates failure
350 */
351 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
352 {
353 struct super_block *sb = ip->i_sb;
354 struct jfs_inode_info *ji = JFS_IP(ip);
355 struct jfs_sb_info *sbi = JFS_SBI(sb);
356 int nblocks;
357 s64 blkno;
358 char *cp = (char *) ealist;
359 int i;
360 int nbytes, nb;
361 s32 bytes_to_read;
362 struct metapage *mp;
363
364 /* quick check for in-line EA */
365 if (ji->ea.flag & DXD_INLINE)
366 return ea_read_inline(ip, ealist);
367
368 nbytes = sizeDXD(&ji->ea);
369 if (!nbytes) {
370 jfs_error(sb, "nbytes is 0\n");
371 return -EIO;
372 }
373
374 /*
375 * Figure out how many blocks were allocated when this EA list was
376 * originally written to disk.
377 */
378 nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
379 blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
380
381 /*
382 * I have found the disk blocks which were originally used to store
383 * the FEALIST. now i loop over each contiguous block copying the
384 * data into the buffer.
385 */
386 for (i = 0; i < nblocks; i += sbi->nbperpage) {
387 /*
388 * Determine how many bytes for this request, and round up to
389 * the nearest aggregate block size
390 */
391 nb = min(PSIZE, nbytes);
392 bytes_to_read =
393 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
394 << sb->s_blocksize_bits;
395
396 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
397 return -EIO;
398
399 memcpy(cp, mp->data, nb);
400 release_metapage(mp);
401
402 cp += PSIZE;
403 nbytes -= nb;
404 }
405
406 return 0;
407 }
408
409 /*
410 * NAME: ea_get
411 *
412 * FUNCTION: Returns buffer containing existing extended attributes.
413 * The size of the buffer will be the larger of the existing
414 * attributes size, or min_size.
415 *
416 * The buffer, which may be inlined in the inode or in the
417 * page cache must be release by calling ea_release or ea_put
418 *
419 * PARAMETERS:
420 * inode - Inode pointer
421 * ea_buf - Structure to be populated with ealist and its metadata
422 * min_size- minimum size of buffer to be returned
423 *
424 * RETURNS: 0 for success; Other indicates failure
425 */
426 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
427 {
428 struct jfs_inode_info *ji = JFS_IP(inode);
429 struct super_block *sb = inode->i_sb;
430 int size;
431 int ea_size = sizeDXD(&ji->ea);
432 int blocks_needed, current_blocks;
433 s64 blkno;
434 int rc;
435 int quota_allocation = 0;
436
437 /* When fsck.jfs clears a bad ea, it doesn't clear the size */
438 if (ji->ea.flag == 0)
439 ea_size = 0;
440
441 if (ea_size == 0) {
442 if (min_size == 0) {
443 ea_buf->flag = 0;
444 ea_buf->max_size = 0;
445 ea_buf->xattr = NULL;
446 return 0;
447 }
448 if ((min_size <= sizeof (ji->i_inline_ea)) &&
449 (ji->mode2 & INLINEEA)) {
450 ea_buf->flag = EA_INLINE | EA_NEW;
451 ea_buf->max_size = sizeof (ji->i_inline_ea);
452 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
453 DXDlength(&ea_buf->new_ea, 0);
454 DXDaddress(&ea_buf->new_ea, 0);
455 ea_buf->new_ea.flag = DXD_INLINE;
456 DXDsize(&ea_buf->new_ea, min_size);
457 return 0;
458 }
459 current_blocks = 0;
460 } else if (ji->ea.flag & DXD_INLINE) {
461 if (min_size <= sizeof (ji->i_inline_ea)) {
462 ea_buf->flag = EA_INLINE;
463 ea_buf->max_size = sizeof (ji->i_inline_ea);
464 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
465 goto size_check;
466 }
467 current_blocks = 0;
468 } else {
469 if (!(ji->ea.flag & DXD_EXTENT)) {
470 jfs_error(sb, "invalid ea.flag\n");
471 return -EIO;
472 }
473 current_blocks = (ea_size + sb->s_blocksize - 1) >>
474 sb->s_blocksize_bits;
475 }
476 size = max(min_size, ea_size);
477
478 if (size > PSIZE) {
479 /*
480 * To keep the rest of the code simple. Allocate a
481 * contiguous buffer to work with. Make the buffer large
482 * enough to make use of the whole extent.
483 */
484 ea_buf->max_size = (size + sb->s_blocksize - 1) &
485 ~(sb->s_blocksize - 1);
486
487 ea_buf->xattr = kmalloc(ea_buf->max_size, GFP_KERNEL);
488 if (ea_buf->xattr == NULL)
489 return -ENOMEM;
490
491 ea_buf->flag = EA_MALLOC;
492
493 if (ea_size == 0)
494 return 0;
495
496 if ((rc = ea_read(inode, ea_buf->xattr))) {
497 kfree(ea_buf->xattr);
498 ea_buf->xattr = NULL;
499 return rc;
500 }
501 goto size_check;
502 }
503 blocks_needed = (min_size + sb->s_blocksize - 1) >>
504 sb->s_blocksize_bits;
505
506 if (blocks_needed > current_blocks) {
507 /* Allocate new blocks to quota. */
508 rc = dquot_alloc_block(inode, blocks_needed);
509 if (rc)
510 return -EDQUOT;
511
512 quota_allocation = blocks_needed;
513
514 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
515 &blkno);
516 if (rc)
517 goto clean_up;
518
519 DXDlength(&ea_buf->new_ea, blocks_needed);
520 DXDaddress(&ea_buf->new_ea, blkno);
521 ea_buf->new_ea.flag = DXD_EXTENT;
522 DXDsize(&ea_buf->new_ea, min_size);
523
524 ea_buf->flag = EA_EXTENT | EA_NEW;
525
526 ea_buf->mp = get_metapage(inode, blkno,
527 blocks_needed << sb->s_blocksize_bits,
528 1);
529 if (ea_buf->mp == NULL) {
530 dbFree(inode, blkno, (s64) blocks_needed);
531 rc = -EIO;
532 goto clean_up;
533 }
534 ea_buf->xattr = ea_buf->mp->data;
535 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
536 ~(sb->s_blocksize - 1);
537 if (ea_size == 0)
538 return 0;
539 if ((rc = ea_read(inode, ea_buf->xattr))) {
540 discard_metapage(ea_buf->mp);
541 dbFree(inode, blkno, (s64) blocks_needed);
542 goto clean_up;
543 }
544 goto size_check;
545 }
546 ea_buf->flag = EA_EXTENT;
547 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
548 lengthDXD(&ji->ea) << sb->s_blocksize_bits,
549 1);
550 if (ea_buf->mp == NULL) {
551 rc = -EIO;
552 goto clean_up;
553 }
554 ea_buf->xattr = ea_buf->mp->data;
555 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
556 ~(sb->s_blocksize - 1);
557
558 size_check:
559 if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
560 int size = min_t(int, EALIST_SIZE(ea_buf->xattr), ea_size);
561
562 printk(KERN_ERR "ea_get: invalid extended attribute\n");
563 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
564 ea_buf->xattr, size, 1);
565 ea_release(inode, ea_buf);
566 rc = -EIO;
567 goto clean_up;
568 }
569
570 return ea_size;
571
572 clean_up:
573 /* Rollback quota allocation */
574 if (quota_allocation)
575 dquot_free_block(inode, quota_allocation);
576
577 return (rc);
578 }
579
580 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
581 {
582 if (ea_buf->flag & EA_MALLOC)
583 kfree(ea_buf->xattr);
584 else if (ea_buf->flag & EA_EXTENT) {
585 assert(ea_buf->mp);
586 release_metapage(ea_buf->mp);
587
588 if (ea_buf->flag & EA_NEW)
589 dbFree(inode, addressDXD(&ea_buf->new_ea),
590 lengthDXD(&ea_buf->new_ea));
591 }
592 }
593
594 static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
595 int new_size)
596 {
597 struct jfs_inode_info *ji = JFS_IP(inode);
598 unsigned long old_blocks, new_blocks;
599 int rc = 0;
600
601 if (new_size == 0) {
602 ea_release(inode, ea_buf);
603 ea_buf = NULL;
604 } else if (ea_buf->flag & EA_INLINE) {
605 assert(new_size <= sizeof (ji->i_inline_ea));
606 ji->mode2 &= ~INLINEEA;
607 ea_buf->new_ea.flag = DXD_INLINE;
608 DXDsize(&ea_buf->new_ea, new_size);
609 DXDaddress(&ea_buf->new_ea, 0);
610 DXDlength(&ea_buf->new_ea, 0);
611 } else if (ea_buf->flag & EA_MALLOC) {
612 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
613 kfree(ea_buf->xattr);
614 } else if (ea_buf->flag & EA_NEW) {
615 /* We have already allocated a new dxd */
616 flush_metapage(ea_buf->mp);
617 } else {
618 /* ->xattr must point to original ea's metapage */
619 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
620 discard_metapage(ea_buf->mp);
621 }
622 if (rc)
623 return rc;
624
625 old_blocks = new_blocks = 0;
626
627 if (ji->ea.flag & DXD_EXTENT) {
628 invalidate_dxd_metapages(inode, ji->ea);
629 old_blocks = lengthDXD(&ji->ea);
630 }
631
632 if (ea_buf) {
633 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
634 if (ea_buf->new_ea.flag & DXD_EXTENT) {
635 new_blocks = lengthDXD(&ea_buf->new_ea);
636 if (ji->ea.flag & DXD_INLINE)
637 ji->mode2 |= INLINEEA;
638 }
639 ji->ea = ea_buf->new_ea;
640 } else {
641 txEA(tid, inode, &ji->ea, NULL);
642 if (ji->ea.flag & DXD_INLINE)
643 ji->mode2 |= INLINEEA;
644 ji->ea.flag = 0;
645 ji->ea.size = 0;
646 }
647
648 /* If old blocks exist, they must be removed from quota allocation. */
649 if (old_blocks)
650 dquot_free_block(inode, old_blocks);
651
652 inode_set_ctime_current(inode);
653
654 return 0;
655 }
656
657 int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
658 const void *value, size_t value_len, int flags)
659 {
660 struct jfs_ea_list *ealist;
661 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
662 struct ea_buffer ea_buf;
663 int old_ea_size = 0;
664 int xattr_size;
665 int new_size;
666 int namelen = strlen(name);
667 int found = 0;
668 int rc;
669 int length;
670
671 down_write(&JFS_IP(inode)->xattr_sem);
672
673 xattr_size = ea_get(inode, &ea_buf, 0);
674 if (xattr_size < 0) {
675 rc = xattr_size;
676 goto out;
677 }
678
679 again:
680 ealist = (struct jfs_ea_list *) ea_buf.xattr;
681 new_size = sizeof (struct jfs_ea_list);
682
683 if (xattr_size) {
684 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
685 ea = NEXT_EA(ea)) {
686 if ((namelen == ea->namelen) &&
687 (memcmp(name, ea->name, namelen) == 0)) {
688 found = 1;
689 if (flags & XATTR_CREATE) {
690 rc = -EEXIST;
691 goto release;
692 }
693 old_ea = ea;
694 old_ea_size = EA_SIZE(ea);
695 next_ea = NEXT_EA(ea);
696 } else
697 new_size += EA_SIZE(ea);
698 }
699 }
700
701 if (!found) {
702 if (flags & XATTR_REPLACE) {
703 rc = -ENODATA;
704 goto release;
705 }
706 if (value == NULL) {
707 rc = 0;
708 goto release;
709 }
710 }
711 if (value)
712 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
713
714 if (new_size > ea_buf.max_size) {
715 /*
716 * We need to allocate more space for merged ea list.
717 * We should only have loop to again: once.
718 */
719 ea_release(inode, &ea_buf);
720 xattr_size = ea_get(inode, &ea_buf, new_size);
721 if (xattr_size < 0) {
722 rc = xattr_size;
723 goto out;
724 }
725 goto again;
726 }
727
728 /* Remove old ea of the same name */
729 if (found) {
730 /* number of bytes following target EA */
731 length = (char *) END_EALIST(ealist) - (char *) next_ea;
732 if (length > 0)
733 memmove(old_ea, next_ea, length);
734 xattr_size -= old_ea_size;
735 }
736
737 /* Add new entry to the end */
738 if (value) {
739 if (xattr_size == 0)
740 /* Completely new ea list */
741 xattr_size = sizeof (struct jfs_ea_list);
742
743 /*
744 * The size of EA value is limitted by on-disk format up to
745 * __le16, there would be an overflow if the size is equal
746 * to XATTR_SIZE_MAX (65536). In order to avoid this issue,
747 * we can pre-checkup the value size against USHRT_MAX, and
748 * return -E2BIG in this case, which is consistent with the
749 * VFS setxattr interface.
750 */
751 if (value_len >= USHRT_MAX) {
752 rc = -E2BIG;
753 goto release;
754 }
755
756 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
757 ea->flag = 0;
758 ea->namelen = namelen;
759 ea->valuelen = (cpu_to_le16(value_len));
760 memcpy(ea->name, name, namelen);
761 ea->name[namelen] = 0;
762 if (value_len)
763 memcpy(&ea->name[namelen + 1], value, value_len);
764 xattr_size += EA_SIZE(ea);
765 }
766
767 /* DEBUG - If we did this right, these number match */
768 if (xattr_size != new_size) {
769 printk(KERN_ERR
770 "__jfs_setxattr: xattr_size = %d, new_size = %d\n",
771 xattr_size, new_size);
772
773 rc = -EINVAL;
774 goto release;
775 }
776
777 /*
778 * If we're left with an empty list, there's no ea
779 */
780 if (new_size == sizeof (struct jfs_ea_list))
781 new_size = 0;
782
783 ealist->size = cpu_to_le32(new_size);
784
785 rc = ea_put(tid, inode, &ea_buf, new_size);
786
787 goto out;
788 release:
789 ea_release(inode, &ea_buf);
790 out:
791 up_write(&JFS_IP(inode)->xattr_sem);
792
793 return rc;
794 }
795
796 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
797 size_t buf_size)
798 {
799 struct jfs_ea_list *ealist;
800 struct jfs_ea *ea, *ealist_end;
801 struct ea_buffer ea_buf;
802 int xattr_size;
803 ssize_t size;
804 int namelen = strlen(name);
805 char *value;
806
807 down_read(&JFS_IP(inode)->xattr_sem);
808
809 xattr_size = ea_get(inode, &ea_buf, 0);
810
811 if (xattr_size < 0) {
812 size = xattr_size;
813 goto out;
814 }
815
816 if (xattr_size == 0)
817 goto not_found;
818
819 ealist = (struct jfs_ea_list *) ea_buf.xattr;
820 ealist_end = END_EALIST(ealist);
821
822 /* Find the named attribute */
823 for (ea = FIRST_EA(ealist); ea < ealist_end; ea = NEXT_EA(ea)) {
824 if (unlikely(ea + 1 > ealist_end) ||
825 unlikely(NEXT_EA(ea) > ealist_end)) {
826 size = -EUCLEAN;
827 goto release;
828 }
829
830 if ((namelen == ea->namelen) &&
831 memcmp(name, ea->name, namelen) == 0) {
832 /* Found it */
833 size = le16_to_cpu(ea->valuelen);
834 if (!data)
835 goto release;
836 else if (size > buf_size) {
837 size = -ERANGE;
838 goto release;
839 }
840 value = ((char *) &ea->name) + ea->namelen + 1;
841 memcpy(data, value, size);
842 goto release;
843 }
844 }
845 not_found:
846 size = -ENODATA;
847 release:
848 ea_release(inode, &ea_buf);
849 out:
850 up_read(&JFS_IP(inode)->xattr_sem);
851
852 return size;
853 }
854
855 /*
856 * No special permissions are needed to list attributes except for trusted.*
857 */
858 static inline int can_list(struct jfs_ea *ea)
859 {
860 return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
861 XATTR_TRUSTED_PREFIX_LEN) ||
862 capable(CAP_SYS_ADMIN));
863 }
864
865 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
866 {
867 struct inode *inode = d_inode(dentry);
868 char *buffer;
869 ssize_t size = 0;
870 int xattr_size;
871 struct jfs_ea_list *ealist;
872 struct jfs_ea *ea, *ealist_end;
873 struct ea_buffer ea_buf;
874
875 down_read(&JFS_IP(inode)->xattr_sem);
876
877 xattr_size = ea_get(inode, &ea_buf, 0);
878 if (xattr_size < 0) {
879 size = xattr_size;
880 goto out;
881 }
882
883 if (xattr_size == 0)
884 goto release;
885
886 ealist = (struct jfs_ea_list *) ea_buf.xattr;
887 ealist_end = END_EALIST(ealist);
888
889 /* compute required size of list */
890 for (ea = FIRST_EA(ealist); ea < ealist_end; ea = NEXT_EA(ea)) {
891 if (unlikely(ea + 1 > ealist_end) ||
892 unlikely(NEXT_EA(ea) > ealist_end)) {
893 size = -EUCLEAN;
894 goto release;
895 }
896
897 if (can_list(ea))
898 size += name_size(ea) + 1;
899 }
900
901 if (!data)
902 goto release;
903
904 if (size > buf_size) {
905 size = -ERANGE;
906 goto release;
907 }
908
909 /* Copy attribute names to buffer */
910 buffer = data;
911 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
912 if (can_list(ea)) {
913 int namelen = copy_name(buffer, ea);
914 buffer += namelen + 1;
915 }
916 }
917
918 release:
919 ea_release(inode, &ea_buf);
920 out:
921 up_read(&JFS_IP(inode)->xattr_sem);
922 return size;
923 }
924
925 static int __jfs_xattr_set(struct inode *inode, const char *name,
926 const void *value, size_t size, int flags)
927 {
928 struct jfs_inode_info *ji = JFS_IP(inode);
929 tid_t tid;
930 int rc;
931
932 tid = txBegin(inode->i_sb, 0);
933 mutex_lock(&ji->commit_mutex);
934 rc = __jfs_setxattr(tid, inode, name, value, size, flags);
935 if (!rc)
936 rc = txCommit(tid, 1, &inode, 0);
937 txEnd(tid);
938 mutex_unlock(&ji->commit_mutex);
939
940 return rc;
941 }
942
943 static int jfs_xattr_get(const struct xattr_handler *handler,
944 struct dentry *unused, struct inode *inode,
945 const char *name, void *value, size_t size)
946 {
947 name = xattr_full_name(handler, name);
948 return __jfs_getxattr(inode, name, value, size);
949 }
950
951 static int jfs_xattr_set(const struct xattr_handler *handler,
952 struct mnt_idmap *idmap,
953 struct dentry *unused, struct inode *inode,
954 const char *name, const void *value,
955 size_t size, int flags)
956 {
957 name = xattr_full_name(handler, name);
958 return __jfs_xattr_set(inode, name, value, size, flags);
959 }
960
961 static int jfs_xattr_get_os2(const struct xattr_handler *handler,
962 struct dentry *unused, struct inode *inode,
963 const char *name, void *value, size_t size)
964 {
965 if (is_known_namespace(name))
966 return -EOPNOTSUPP;
967 return __jfs_getxattr(inode, name, value, size);
968 }
969
970 static int jfs_xattr_set_os2(const struct xattr_handler *handler,
971 struct mnt_idmap *idmap,
972 struct dentry *unused, struct inode *inode,
973 const char *name, const void *value,
974 size_t size, int flags)
975 {
976 if (is_known_namespace(name))
977 return -EOPNOTSUPP;
978 return __jfs_xattr_set(inode, name, value, size, flags);
979 }
980
981 static const struct xattr_handler jfs_user_xattr_handler = {
982 .prefix = XATTR_USER_PREFIX,
983 .get = jfs_xattr_get,
984 .set = jfs_xattr_set,
985 };
986
987 static const struct xattr_handler jfs_os2_xattr_handler = {
988 .prefix = XATTR_OS2_PREFIX,
989 .get = jfs_xattr_get_os2,
990 .set = jfs_xattr_set_os2,
991 };
992
993 static const struct xattr_handler jfs_security_xattr_handler = {
994 .prefix = XATTR_SECURITY_PREFIX,
995 .get = jfs_xattr_get,
996 .set = jfs_xattr_set,
997 };
998
999 static const struct xattr_handler jfs_trusted_xattr_handler = {
1000 .prefix = XATTR_TRUSTED_PREFIX,
1001 .get = jfs_xattr_get,
1002 .set = jfs_xattr_set,
1003 };
1004
1005 const struct xattr_handler * const jfs_xattr_handlers[] = {
1006 &jfs_os2_xattr_handler,
1007 &jfs_user_xattr_handler,
1008 &jfs_security_xattr_handler,
1009 &jfs_trusted_xattr_handler,
1010 NULL,
1011 };
1012
1013
1014 #ifdef CONFIG_JFS_SECURITY
1015 static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
1016 void *fs_info)
1017 {
1018 const struct xattr *xattr;
1019 tid_t *tid = fs_info;
1020 char *name;
1021 int err = 0;
1022
1023 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
1024 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
1025 strlen(xattr->name) + 1, GFP_NOFS);
1026 if (!name) {
1027 err = -ENOMEM;
1028 break;
1029 }
1030 strcpy(name, XATTR_SECURITY_PREFIX);
1031 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
1032
1033 err = __jfs_setxattr(*tid, inode, name,
1034 xattr->value, xattr->value_len, 0);
1035 kfree(name);
1036 if (err < 0)
1037 break;
1038 }
1039 return err;
1040 }
1041
1042 int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
1043 const struct qstr *qstr)
1044 {
1045 return security_inode_init_security(inode, dir, qstr,
1046 &jfs_initxattrs, &tid);
1047 }
1048 #endif
1049
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