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
is_known_namespace(const char * name)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
name_size(struct jfs_ea * ea)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
copy_name(char * buffer,struct jfs_ea * ea)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 */
ea_write_inline(struct inode * ip,struct jfs_ea_list * ealist,int size,dxd_t * ea)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 */
ea_write(struct inode * ip,struct jfs_ea_list * ealist,int size,dxd_t * ea)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 */
ea_read_inline(struct inode * ip,struct jfs_ea_list * ealist)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 */
ea_read(struct inode * ip,struct jfs_ea_list * ealist)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 */
ea_get(struct inode * inode,struct ea_buffer * ea_buf,int min_size)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 memset(&ea_buf->new_ea, 0, sizeof(ea_buf->new_ea));
438
439 /* When fsck.jfs clears a bad ea, it doesn't clear the size */
440 if (ji->ea.flag == 0)
441 ea_size = 0;
442
443 if (ea_size == 0) {
444 if (min_size == 0) {
445 ea_buf->flag = 0;
446 ea_buf->max_size = 0;
447 ea_buf->xattr = NULL;
448 return 0;
449 }
450 if ((min_size <= sizeof (ji->i_inline_ea)) &&
451 (ji->mode2 & INLINEEA)) {
452 ea_buf->flag = EA_INLINE | EA_NEW;
453 ea_buf->max_size = sizeof (ji->i_inline_ea);
454 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
455 DXDlength(&ea_buf->new_ea, 0);
456 DXDaddress(&ea_buf->new_ea, 0);
457 ea_buf->new_ea.flag = DXD_INLINE;
458 DXDsize(&ea_buf->new_ea, min_size);
459 return 0;
460 }
461 current_blocks = 0;
462 } else if (ji->ea.flag & DXD_INLINE) {
463 if (min_size <= sizeof (ji->i_inline_ea)) {
464 ea_buf->flag = EA_INLINE;
465 ea_buf->max_size = sizeof (ji->i_inline_ea);
466 ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea;
467 goto size_check;
468 }
469 current_blocks = 0;
470 } else {
471 if (!(ji->ea.flag & DXD_EXTENT)) {
472 jfs_error(sb, "invalid ea.flag\n");
473 return -EIO;
474 }
475 current_blocks = (ea_size + sb->s_blocksize - 1) >>
476 sb->s_blocksize_bits;
477 }
478 size = max(min_size, ea_size);
479
480 if (size > PSIZE) {
481 /*
482 * To keep the rest of the code simple. Allocate a
483 * contiguous buffer to work with. Make the buffer large
484 * enough to make use of the whole extent.
485 */
486 ea_buf->max_size = (size + sb->s_blocksize - 1) &
487 ~(sb->s_blocksize - 1);
488
489 ea_buf->xattr = kmalloc(ea_buf->max_size, GFP_KERNEL);
490 if (ea_buf->xattr == NULL)
491 return -ENOMEM;
492
493 ea_buf->flag = EA_MALLOC;
494
495 if (ea_size == 0)
496 return 0;
497
498 if ((rc = ea_read(inode, ea_buf->xattr))) {
499 kfree(ea_buf->xattr);
500 ea_buf->xattr = NULL;
501 return rc;
502 }
503 goto size_check;
504 }
505 blocks_needed = (min_size + sb->s_blocksize - 1) >>
506 sb->s_blocksize_bits;
507
508 if (blocks_needed > current_blocks) {
509 /* Allocate new blocks to quota. */
510 rc = dquot_alloc_block(inode, blocks_needed);
511 if (rc)
512 return -EDQUOT;
513
514 quota_allocation = blocks_needed;
515
516 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
517 &blkno);
518 if (rc)
519 goto clean_up;
520
521 DXDlength(&ea_buf->new_ea, blocks_needed);
522 DXDaddress(&ea_buf->new_ea, blkno);
523 ea_buf->new_ea.flag = DXD_EXTENT;
524 DXDsize(&ea_buf->new_ea, min_size);
525
526 ea_buf->flag = EA_EXTENT | EA_NEW;
527
528 ea_buf->mp = get_metapage(inode, blkno,
529 blocks_needed << sb->s_blocksize_bits,
530 1);
531 if (ea_buf->mp == NULL) {
532 dbFree(inode, blkno, (s64) blocks_needed);
533 rc = -EIO;
534 goto clean_up;
535 }
536 ea_buf->xattr = ea_buf->mp->data;
537 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
538 ~(sb->s_blocksize - 1);
539 if (ea_size == 0)
540 return 0;
541 if ((rc = ea_read(inode, ea_buf->xattr))) {
542 discard_metapage(ea_buf->mp);
543 dbFree(inode, blkno, (s64) blocks_needed);
544 goto clean_up;
545 }
546 goto size_check;
547 }
548 ea_buf->flag = EA_EXTENT;
549 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
550 lengthDXD(&ji->ea) << sb->s_blocksize_bits,
551 1);
552 if (ea_buf->mp == NULL) {
553 rc = -EIO;
554 goto clean_up;
555 }
556 ea_buf->xattr = ea_buf->mp->data;
557 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
558 ~(sb->s_blocksize - 1);
559
560 size_check:
561 if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
562 if (unlikely(EALIST_SIZE(ea_buf->xattr) > INT_MAX)) {
563 printk(KERN_ERR "ea_get: extended attribute size too large: %u > INT_MAX\n",
564 EALIST_SIZE(ea_buf->xattr));
565 } else {
566 int size = clamp_t(int, ea_size, 0, EALIST_SIZE(ea_buf->xattr));
567
568 printk(KERN_ERR "ea_get: invalid extended attribute\n");
569 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
570 ea_buf->xattr, size, 1);
571 }
572 ea_release(inode, ea_buf);
573 rc = -EIO;
574 goto clean_up;
575 }
576
577 return ea_size;
578
579 clean_up:
580 /* Rollback quota allocation */
581 if (quota_allocation)
582 dquot_free_block(inode, quota_allocation);
583
584 return (rc);
585 }
586
ea_release(struct inode * inode,struct ea_buffer * ea_buf)587 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
588 {
589 if (ea_buf->flag & EA_MALLOC)
590 kfree(ea_buf->xattr);
591 else if (ea_buf->flag & EA_EXTENT) {
592 assert(ea_buf->mp);
593 release_metapage(ea_buf->mp);
594
595 if (ea_buf->flag & EA_NEW)
596 dbFree(inode, addressDXD(&ea_buf->new_ea),
597 lengthDXD(&ea_buf->new_ea));
598 }
599 }
600
ea_put(tid_t tid,struct inode * inode,struct ea_buffer * ea_buf,int new_size)601 static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
602 int new_size)
603 {
604 struct jfs_inode_info *ji = JFS_IP(inode);
605 unsigned long old_blocks, new_blocks;
606 int rc = 0;
607
608 if (new_size == 0) {
609 ea_release(inode, ea_buf);
610 ea_buf = NULL;
611 } else if (ea_buf->flag & EA_INLINE) {
612 assert(new_size <= sizeof (ji->i_inline_ea));
613 ji->mode2 &= ~INLINEEA;
614 ea_buf->new_ea.flag = DXD_INLINE;
615 DXDsize(&ea_buf->new_ea, new_size);
616 DXDaddress(&ea_buf->new_ea, 0);
617 DXDlength(&ea_buf->new_ea, 0);
618 } else if (ea_buf->flag & EA_MALLOC) {
619 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
620 kfree(ea_buf->xattr);
621 } else if (ea_buf->flag & EA_NEW) {
622 /* We have already allocated a new dxd */
623 flush_metapage(ea_buf->mp);
624 } else {
625 /* ->xattr must point to original ea's metapage */
626 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
627 discard_metapage(ea_buf->mp);
628 }
629 if (rc)
630 return rc;
631
632 old_blocks = new_blocks = 0;
633
634 if (ji->ea.flag & DXD_EXTENT) {
635 invalidate_dxd_metapages(inode, ji->ea);
636 old_blocks = lengthDXD(&ji->ea);
637 }
638
639 if (ea_buf) {
640 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
641 if (ea_buf->new_ea.flag & DXD_EXTENT) {
642 new_blocks = lengthDXD(&ea_buf->new_ea);
643 if (ji->ea.flag & DXD_INLINE)
644 ji->mode2 |= INLINEEA;
645 }
646 ji->ea = ea_buf->new_ea;
647 } else {
648 txEA(tid, inode, &ji->ea, NULL);
649 if (ji->ea.flag & DXD_INLINE)
650 ji->mode2 |= INLINEEA;
651 ji->ea.flag = 0;
652 ji->ea.size = 0;
653 }
654
655 /* If old blocks exist, they must be removed from quota allocation. */
656 if (old_blocks)
657 dquot_free_block(inode, old_blocks);
658
659 inode_set_ctime_current(inode);
660
661 return 0;
662 }
663
__jfs_setxattr(tid_t tid,struct inode * inode,const char * name,const void * value,size_t value_len,int flags)664 int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
665 const void *value, size_t value_len, int flags)
666 {
667 struct jfs_ea_list *ealist;
668 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
669 struct ea_buffer ea_buf;
670 int old_ea_size = 0;
671 int xattr_size;
672 int new_size;
673 int namelen = strlen(name);
674 int found = 0;
675 int rc;
676 int length;
677
678 down_write(&JFS_IP(inode)->xattr_sem);
679
680 xattr_size = ea_get(inode, &ea_buf, 0);
681 if (xattr_size < 0) {
682 rc = xattr_size;
683 goto out;
684 }
685
686 again:
687 ealist = (struct jfs_ea_list *) ea_buf.xattr;
688 new_size = sizeof (struct jfs_ea_list);
689
690 if (xattr_size) {
691 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
692 ea = NEXT_EA(ea)) {
693 if ((namelen == ea->namelen) &&
694 (memcmp(name, ea->name, namelen) == 0)) {
695 found = 1;
696 if (flags & XATTR_CREATE) {
697 rc = -EEXIST;
698 goto release;
699 }
700 old_ea = ea;
701 old_ea_size = EA_SIZE(ea);
702 next_ea = NEXT_EA(ea);
703 } else
704 new_size += EA_SIZE(ea);
705 }
706 }
707
708 if (!found) {
709 if (flags & XATTR_REPLACE) {
710 rc = -ENODATA;
711 goto release;
712 }
713 if (value == NULL) {
714 rc = 0;
715 goto release;
716 }
717 }
718 if (value)
719 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
720
721 if (new_size > ea_buf.max_size) {
722 /*
723 * We need to allocate more space for merged ea list.
724 * We should only have loop to again: once.
725 */
726 ea_release(inode, &ea_buf);
727 xattr_size = ea_get(inode, &ea_buf, new_size);
728 if (xattr_size < 0) {
729 rc = xattr_size;
730 goto out;
731 }
732 goto again;
733 }
734
735 /* Remove old ea of the same name */
736 if (found) {
737 /* number of bytes following target EA */
738 length = (char *) END_EALIST(ealist) - (char *) next_ea;
739 if (length > 0)
740 memmove(old_ea, next_ea, length);
741 xattr_size -= old_ea_size;
742 }
743
744 /* Add new entry to the end */
745 if (value) {
746 if (xattr_size == 0)
747 /* Completely new ea list */
748 xattr_size = sizeof (struct jfs_ea_list);
749
750 /*
751 * The size of EA value is limitted by on-disk format up to
752 * __le16, there would be an overflow if the size is equal
753 * to XATTR_SIZE_MAX (65536). In order to avoid this issue,
754 * we can pre-checkup the value size against USHRT_MAX, and
755 * return -E2BIG in this case, which is consistent with the
756 * VFS setxattr interface.
757 */
758 if (value_len >= USHRT_MAX) {
759 rc = -E2BIG;
760 goto release;
761 }
762
763 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
764 ea->flag = 0;
765 ea->namelen = namelen;
766 ea->valuelen = (cpu_to_le16(value_len));
767 memcpy(ea->name, name, namelen);
768 ea->name[namelen] = 0;
769 if (value_len)
770 memcpy(&ea->name[namelen + 1], value, value_len);
771 xattr_size += EA_SIZE(ea);
772 }
773
774 /* DEBUG - If we did this right, these number match */
775 if (xattr_size != new_size) {
776 printk(KERN_ERR
777 "__jfs_setxattr: xattr_size = %d, new_size = %d\n",
778 xattr_size, new_size);
779
780 rc = -EINVAL;
781 goto release;
782 }
783
784 /*
785 * If we're left with an empty list, there's no ea
786 */
787 if (new_size == sizeof (struct jfs_ea_list))
788 new_size = 0;
789
790 ealist->size = cpu_to_le32(new_size);
791
792 rc = ea_put(tid, inode, &ea_buf, new_size);
793
794 goto out;
795 release:
796 ea_release(inode, &ea_buf);
797 out:
798 up_write(&JFS_IP(inode)->xattr_sem);
799
800 return rc;
801 }
802
__jfs_getxattr(struct inode * inode,const char * name,void * data,size_t buf_size)803 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
804 size_t buf_size)
805 {
806 struct jfs_ea_list *ealist;
807 struct jfs_ea *ea, *ealist_end;
808 struct ea_buffer ea_buf;
809 int xattr_size;
810 ssize_t size;
811 int namelen = strlen(name);
812 char *value;
813
814 down_read(&JFS_IP(inode)->xattr_sem);
815
816 xattr_size = ea_get(inode, &ea_buf, 0);
817
818 if (xattr_size < 0) {
819 size = xattr_size;
820 goto out;
821 }
822
823 if (xattr_size == 0)
824 goto not_found;
825
826 ealist = (struct jfs_ea_list *) ea_buf.xattr;
827 ealist_end = END_EALIST(ealist);
828
829 /* Find the named attribute */
830 for (ea = FIRST_EA(ealist); ea < ealist_end; ea = NEXT_EA(ea)) {
831 if (unlikely(ea + 1 > ealist_end) ||
832 unlikely(NEXT_EA(ea) > ealist_end)) {
833 size = -EUCLEAN;
834 goto release;
835 }
836
837 if ((namelen == ea->namelen) &&
838 memcmp(name, ea->name, namelen) == 0) {
839 /* Found it */
840 size = le16_to_cpu(ea->valuelen);
841 if (!data)
842 goto release;
843 else if (size > buf_size) {
844 size = -ERANGE;
845 goto release;
846 }
847 value = ((char *) &ea->name) + ea->namelen + 1;
848 memcpy(data, value, size);
849 goto release;
850 }
851 }
852 not_found:
853 size = -ENODATA;
854 release:
855 ea_release(inode, &ea_buf);
856 out:
857 up_read(&JFS_IP(inode)->xattr_sem);
858
859 return size;
860 }
861
862 /*
863 * No special permissions are needed to list attributes except for trusted.*
864 */
can_list(struct jfs_ea * ea)865 static inline int can_list(struct jfs_ea *ea)
866 {
867 return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
868 XATTR_TRUSTED_PREFIX_LEN) ||
869 capable(CAP_SYS_ADMIN));
870 }
871
jfs_listxattr(struct dentry * dentry,char * data,size_t buf_size)872 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
873 {
874 struct inode *inode = d_inode(dentry);
875 char *buffer;
876 ssize_t size = 0;
877 int xattr_size;
878 struct jfs_ea_list *ealist;
879 struct jfs_ea *ea, *ealist_end;
880 struct ea_buffer ea_buf;
881
882 down_read(&JFS_IP(inode)->xattr_sem);
883
884 xattr_size = ea_get(inode, &ea_buf, 0);
885 if (xattr_size < 0) {
886 size = xattr_size;
887 goto out;
888 }
889
890 if (xattr_size == 0)
891 goto release;
892
893 ealist = (struct jfs_ea_list *) ea_buf.xattr;
894 ealist_end = END_EALIST(ealist);
895
896 /* compute required size of list */
897 for (ea = FIRST_EA(ealist); ea < ealist_end; ea = NEXT_EA(ea)) {
898 if (unlikely(ea + 1 > ealist_end) ||
899 unlikely(NEXT_EA(ea) > ealist_end)) {
900 size = -EUCLEAN;
901 goto release;
902 }
903
904 if (can_list(ea))
905 size += name_size(ea) + 1;
906 }
907
908 if (!data)
909 goto release;
910
911 if (size > buf_size) {
912 size = -ERANGE;
913 goto release;
914 }
915
916 /* Copy attribute names to buffer */
917 buffer = data;
918 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
919 if (can_list(ea)) {
920 int namelen = copy_name(buffer, ea);
921 buffer += namelen + 1;
922 }
923 }
924
925 release:
926 ea_release(inode, &ea_buf);
927 out:
928 up_read(&JFS_IP(inode)->xattr_sem);
929 return size;
930 }
931
__jfs_xattr_set(struct inode * inode,const char * name,const void * value,size_t size,int flags)932 static int __jfs_xattr_set(struct inode *inode, const char *name,
933 const void *value, size_t size, int flags)
934 {
935 struct jfs_inode_info *ji = JFS_IP(inode);
936 tid_t tid;
937 int rc;
938
939 tid = txBegin(inode->i_sb, 0);
940 mutex_lock(&ji->commit_mutex);
941 rc = __jfs_setxattr(tid, inode, name, value, size, flags);
942 if (!rc)
943 rc = txCommit(tid, 1, &inode, 0);
944 txEnd(tid);
945 mutex_unlock(&ji->commit_mutex);
946
947 return rc;
948 }
949
jfs_xattr_get(const struct xattr_handler * handler,struct dentry * unused,struct inode * inode,const char * name,void * value,size_t size)950 static int jfs_xattr_get(const struct xattr_handler *handler,
951 struct dentry *unused, struct inode *inode,
952 const char *name, void *value, size_t size)
953 {
954 name = xattr_full_name(handler, name);
955 return __jfs_getxattr(inode, name, value, size);
956 }
957
jfs_xattr_set(const struct xattr_handler * handler,struct mnt_idmap * idmap,struct dentry * unused,struct inode * inode,const char * name,const void * value,size_t size,int flags)958 static int jfs_xattr_set(const struct xattr_handler *handler,
959 struct mnt_idmap *idmap,
960 struct dentry *unused, struct inode *inode,
961 const char *name, const void *value,
962 size_t size, int flags)
963 {
964 name = xattr_full_name(handler, name);
965 return __jfs_xattr_set(inode, name, value, size, flags);
966 }
967
jfs_xattr_get_os2(const struct xattr_handler * handler,struct dentry * unused,struct inode * inode,const char * name,void * value,size_t size)968 static int jfs_xattr_get_os2(const struct xattr_handler *handler,
969 struct dentry *unused, struct inode *inode,
970 const char *name, void *value, size_t size)
971 {
972 if (is_known_namespace(name))
973 return -EOPNOTSUPP;
974 return __jfs_getxattr(inode, name, value, size);
975 }
976
jfs_xattr_set_os2(const struct xattr_handler * handler,struct mnt_idmap * idmap,struct dentry * unused,struct inode * inode,const char * name,const void * value,size_t size,int flags)977 static int jfs_xattr_set_os2(const struct xattr_handler *handler,
978 struct mnt_idmap *idmap,
979 struct dentry *unused, struct inode *inode,
980 const char *name, const void *value,
981 size_t size, int flags)
982 {
983 if (is_known_namespace(name))
984 return -EOPNOTSUPP;
985 return __jfs_xattr_set(inode, name, value, size, flags);
986 }
987
988 static const struct xattr_handler jfs_user_xattr_handler = {
989 .prefix = XATTR_USER_PREFIX,
990 .get = jfs_xattr_get,
991 .set = jfs_xattr_set,
992 };
993
994 static const struct xattr_handler jfs_os2_xattr_handler = {
995 .prefix = XATTR_OS2_PREFIX,
996 .get = jfs_xattr_get_os2,
997 .set = jfs_xattr_set_os2,
998 };
999
1000 static const struct xattr_handler jfs_security_xattr_handler = {
1001 .prefix = XATTR_SECURITY_PREFIX,
1002 .get = jfs_xattr_get,
1003 .set = jfs_xattr_set,
1004 };
1005
1006 static const struct xattr_handler jfs_trusted_xattr_handler = {
1007 .prefix = XATTR_TRUSTED_PREFIX,
1008 .get = jfs_xattr_get,
1009 .set = jfs_xattr_set,
1010 };
1011
1012 const struct xattr_handler *jfs_xattr_handlers[] = {
1013 &jfs_os2_xattr_handler,
1014 &jfs_user_xattr_handler,
1015 &jfs_security_xattr_handler,
1016 &jfs_trusted_xattr_handler,
1017 NULL,
1018 };
1019
1020
1021 #ifdef CONFIG_JFS_SECURITY
jfs_initxattrs(struct inode * inode,const struct xattr * xattr_array,void * fs_info)1022 static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
1023 void *fs_info)
1024 {
1025 const struct xattr *xattr;
1026 tid_t *tid = fs_info;
1027 char *name;
1028 int err = 0;
1029
1030 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
1031 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
1032 strlen(xattr->name) + 1, GFP_NOFS);
1033 if (!name) {
1034 err = -ENOMEM;
1035 break;
1036 }
1037 strcpy(name, XATTR_SECURITY_PREFIX);
1038 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
1039
1040 err = __jfs_setxattr(*tid, inode, name,
1041 xattr->value, xattr->value_len, 0);
1042 kfree(name);
1043 if (err < 0)
1044 break;
1045 }
1046 return err;
1047 }
1048
jfs_init_security(tid_t tid,struct inode * inode,struct inode * dir,const struct qstr * qstr)1049 int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
1050 const struct qstr *qstr)
1051 {
1052 return security_inode_init_security(inode, dir, qstr,
1053 &jfs_initxattrs, &tid);
1054 }
1055 #endif
1056