2 * Copyright (C) International Business Machines Corp., 2000-2004
3 * Copyright (C) Christoph Hellwig, 2002
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.
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.
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
20 #include <linux/capability.h>
22 #include <linux/xattr.h>
23 #include <linux/posix_acl_xattr.h>
24 #include <linux/slab.h>
25 #include <linux/quotaops.h>
26 #include <linux/security.h>
27 #include "jfs_incore.h"
28 #include "jfs_superblock.h"
30 #include "jfs_debug.h"
31 #include "jfs_dinode.h"
32 #include "jfs_extent.h"
33 #include "jfs_metapage.h"
34 #include "jfs_xattr.h"
38 * jfs_xattr.c: extended attribute service
44 * Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
45 * value) and a variable (0 or more) number of extended attribute
46 * entries. Each extended attribute entry (jfs_ea) is a <name,value> double
47 * where <name> is constructed from a null-terminated ascii string
48 * (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
49 * (1 ... 65535 bytes). The in-memory format is
51 * 0 1 2 4 4 + namelen + 1
52 * +-------+--------+--------+----------------+-------------------+
53 * | Flags | Name | Value | Name String \0 | Data . . . . |
54 * | | Length | Length | | |
55 * +-------+--------+--------+----------------+-------------------+
57 * A jfs_ea_list then is structured as
59 * 0 4 4 + EA_SIZE(ea1)
60 * +------------+-------------------+--------------------+-----
61 * | Overall EA | First FEA Element | Second FEA Element | .....
63 * +------------+-------------------+--------------------+-----
67 * FEALISTs are stored on disk using blocks allocated by dbAlloc() and
68 * written directly. An EA list may be in-lined in the inode if there is
69 * sufficient room available.
73 int flag; /* Indicates what storage xattr points to */
74 int max_size; /* largest xattr that fits in current buffer */
75 dxd_t new_ea; /* dxd to replace ea when modifying xattr */
76 struct metapage *mp; /* metapage containing ea list */
77 struct jfs_ea_list *xattr; /* buffer containing ea list */
81 * ea_buffer.flag values
83 #define EA_INLINE 0x0001
84 #define EA_EXTENT 0x0002
86 #define EA_MALLOC 0x0008
89 static int is_known_namespace(const char *name)
91 if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
92 strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
93 strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
94 strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
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
105 static int is_os2_xattr(struct jfs_ea *ea)
107 return !is_known_namespace(ea->name);
110 static inline int name_size(struct jfs_ea *ea)
112 if (is_os2_xattr(ea))
113 return ea->namelen + XATTR_OS2_PREFIX_LEN;
118 static inline int copy_name(char *buffer, struct jfs_ea *ea)
120 int len = ea->namelen;
122 if (is_os2_xattr(ea)) {
123 memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
124 buffer += XATTR_OS2_PREFIX_LEN;
125 len += XATTR_OS2_PREFIX_LEN;
127 memcpy(buffer, ea->name, ea->namelen);
128 buffer[ea->namelen] = 0;
133 /* Forward references */
134 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
137 * NAME: ea_write_inline
139 * FUNCTION: Attempt to write an EA inline if area is available
142 * Already verified that the specified EA is small enough to fit inline
146 * ealist - EA list pointer
147 * size - size of ealist in bytes
148 * ea - dxd_t structure to be filled in with necessary EA information
149 * if we successfully copy the EA inline
152 * Checks if the inode's inline area is available. If so, copies EA inline
153 * and sets <ea> fields appropriately. Otherwise, returns failure, EA will
154 * have to be put into an extent.
156 * RETURNS: 0 for successful copy to inline area; -1 if area not available
158 static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist,
159 int size, dxd_t * ea)
161 struct jfs_inode_info *ji = JFS_IP(ip);
164 * Make sure we have an EA -- the NULL EA list is valid, but you
167 if (ealist && size > sizeof (struct jfs_ea_list)) {
168 assert(size <= sizeof (ji->i_inline_ea));
171 * See if the space is available or if it is already being
172 * used for an inline EA.
174 if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE))
180 memcpy(ji->i_inline_ea, ealist, size);
181 ea->flag = DXD_INLINE;
182 ji->mode2 &= ~INLINEEA;
189 /* Free up INLINE area */
190 if (ji->ea.flag & DXD_INLINE)
191 ji->mode2 |= INLINEEA;
200 * FUNCTION: Write an EA for an inode
202 * PRE CONDITIONS: EA has been verified
206 * ealist - EA list pointer
207 * size - size of ealist in bytes
208 * ea - dxd_t structure to be filled in appropriately with where the
211 * NOTES: Will write EA inline if able to, otherwise allocates blocks for an
212 * extent and synchronously writes it to those blocks.
214 * RETURNS: 0 for success; Anything else indicates failure
216 static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size,
219 struct super_block *sb = ip->i_sb;
220 struct jfs_inode_info *ji = JFS_IP(ip);
221 struct jfs_sb_info *sbi = JFS_SBI(sb);
231 * Quick check to see if this is an in-linable EA. Short EAs
232 * and empty EAs are all in-linable, provided the space exists.
234 if (!ealist || size <= sizeof (ji->i_inline_ea)) {
235 if (!ea_write_inline(ip, ealist, size, ea))
239 /* figure out how many blocks we need */
240 nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits;
242 /* Allocate new blocks to quota. */
243 rc = dquot_alloc_block(ip, nblocks);
247 rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno);
249 /*Rollback quota allocation. */
250 dquot_free_block(ip, nblocks);
255 * Now have nblocks worth of storage to stuff into the FEALIST.
256 * loop over the FEALIST copying data into the buffer one page at
259 cp = (char *) ealist;
261 for (i = 0; i < nblocks; i += sbi->nbperpage) {
263 * Determine how many bytes for this request, and round up to
264 * the nearest aggregate block size
266 nb = min(PSIZE, nbytes);
268 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
269 << sb->s_blocksize_bits;
271 if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) {
276 memcpy(mp->data, cp, nb);
279 * We really need a way to propagate errors for
280 * forced writes like this one. --hch
282 * (__write_metapage => release_metapage => flush_metapage)
285 if ((rc = flush_metapage(mp))) {
287 * the write failed -- this means that the buffer
288 * is still assigned and the blocks are not being
289 * used. this seems like the best error recovery
302 ea->flag = DXD_EXTENT;
303 DXDsize(ea, le32_to_cpu(ealist->size));
304 DXDlength(ea, nblocks);
305 DXDaddress(ea, blkno);
307 /* Free up INLINE area */
308 if (ji->ea.flag & DXD_INLINE)
309 ji->mode2 |= INLINEEA;
314 /* Rollback quota allocation. */
315 dquot_free_block(ip, nblocks);
317 dbFree(ip, blkno, nblocks);
322 * NAME: ea_read_inline
324 * FUNCTION: Read an inlined EA into user's buffer
328 * ealist - Pointer to buffer to fill in with EA
332 static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist)
334 struct jfs_inode_info *ji = JFS_IP(ip);
335 int ea_size = sizeDXD(&ji->ea);
343 if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea)))
345 if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size)
349 memcpy(ealist, ji->i_inline_ea, ea_size);
356 * FUNCTION: copy EA data into user's buffer
360 * ealist - Pointer to buffer to fill in with EA
362 * NOTES: If EA is inline calls ea_read_inline() to copy EA.
364 * RETURNS: 0 for success; other indicates failure
366 static int ea_read(struct inode *ip, struct jfs_ea_list *ealist)
368 struct super_block *sb = ip->i_sb;
369 struct jfs_inode_info *ji = JFS_IP(ip);
370 struct jfs_sb_info *sbi = JFS_SBI(sb);
373 char *cp = (char *) ealist;
379 /* quick check for in-line EA */
380 if (ji->ea.flag & DXD_INLINE)
381 return ea_read_inline(ip, ealist);
383 nbytes = sizeDXD(&ji->ea);
385 jfs_error(sb, "nbytes is 0\n");
390 * Figure out how many blocks were allocated when this EA list was
391 * originally written to disk.
393 nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage;
394 blkno = addressDXD(&ji->ea) << sbi->l2nbperpage;
397 * I have found the disk blocks which were originally used to store
398 * the FEALIST. now i loop over each contiguous block copying the
399 * data into the buffer.
401 for (i = 0; i < nblocks; i += sbi->nbperpage) {
403 * Determine how many bytes for this request, and round up to
404 * the nearest aggregate block size
406 nb = min(PSIZE, nbytes);
408 ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits))
409 << sb->s_blocksize_bits;
411 if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1)))
414 memcpy(cp, mp->data, nb);
415 release_metapage(mp);
427 * FUNCTION: Returns buffer containing existing extended attributes.
428 * The size of the buffer will be the larger of the existing
429 * attributes size, or min_size.
431 * The buffer, which may be inlined in the inode or in the
432 * page cache must be release by calling ea_release or ea_put
435 * inode - Inode pointer
436 * ea_buf - Structure to be populated with ealist and its metadata
437 * min_size- minimum size of buffer to be returned
439 * RETURNS: 0 for success; Other indicates failure
441 static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
443 struct jfs_inode_info *ji = JFS_IP(inode);
444 struct super_block *sb = inode->i_sb;
446 int ea_size = sizeDXD(&ji->ea);
447 int blocks_needed, current_blocks;
450 int quota_allocation = 0;
452 /* When fsck.jfs clears a bad ea, it doesn't clear the size */
453 if (ji->ea.flag == 0)
459 ea_buf->max_size = 0;
460 ea_buf->xattr = NULL;
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);
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;
484 if (!(ji->ea.flag & DXD_EXTENT)) {
485 jfs_error(sb, "invalid ea.flag\n");
488 current_blocks = (ea_size + sb->s_blocksize - 1) >>
489 sb->s_blocksize_bits;
491 size = max(min_size, ea_size);
495 * To keep the rest of the code simple. Allocate a
496 * contiguous buffer to work with
498 ea_buf->xattr = kmalloc(size, GFP_KERNEL);
499 if (ea_buf->xattr == NULL)
502 ea_buf->flag = EA_MALLOC;
503 ea_buf->max_size = (size + sb->s_blocksize - 1) &
504 ~(sb->s_blocksize - 1);
509 if ((rc = ea_read(inode, ea_buf->xattr))) {
510 kfree(ea_buf->xattr);
511 ea_buf->xattr = NULL;
516 blocks_needed = (min_size + sb->s_blocksize - 1) >>
517 sb->s_blocksize_bits;
519 if (blocks_needed > current_blocks) {
520 /* Allocate new blocks to quota. */
521 rc = dquot_alloc_block(inode, blocks_needed);
525 quota_allocation = blocks_needed;
527 rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed,
532 DXDlength(&ea_buf->new_ea, blocks_needed);
533 DXDaddress(&ea_buf->new_ea, blkno);
534 ea_buf->new_ea.flag = DXD_EXTENT;
535 DXDsize(&ea_buf->new_ea, min_size);
537 ea_buf->flag = EA_EXTENT | EA_NEW;
539 ea_buf->mp = get_metapage(inode, blkno,
540 blocks_needed << sb->s_blocksize_bits,
542 if (ea_buf->mp == NULL) {
543 dbFree(inode, blkno, (s64) blocks_needed);
547 ea_buf->xattr = ea_buf->mp->data;
548 ea_buf->max_size = (min_size + sb->s_blocksize - 1) &
549 ~(sb->s_blocksize - 1);
552 if ((rc = ea_read(inode, ea_buf->xattr))) {
553 discard_metapage(ea_buf->mp);
554 dbFree(inode, blkno, (s64) blocks_needed);
559 ea_buf->flag = EA_EXTENT;
560 ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea),
561 lengthDXD(&ji->ea) << sb->s_blocksize_bits,
563 if (ea_buf->mp == NULL) {
567 ea_buf->xattr = ea_buf->mp->data;
568 ea_buf->max_size = (ea_size + sb->s_blocksize - 1) &
569 ~(sb->s_blocksize - 1);
572 if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
573 printk(KERN_ERR "ea_get: invalid extended attribute\n");
574 print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
575 ea_buf->xattr, ea_size, 1);
576 ea_release(inode, ea_buf);
584 /* Rollback quota allocation */
585 if (quota_allocation)
586 dquot_free_block(inode, quota_allocation);
591 static void ea_release(struct inode *inode, struct ea_buffer *ea_buf)
593 if (ea_buf->flag & EA_MALLOC)
594 kfree(ea_buf->xattr);
595 else if (ea_buf->flag & EA_EXTENT) {
597 release_metapage(ea_buf->mp);
599 if (ea_buf->flag & EA_NEW)
600 dbFree(inode, addressDXD(&ea_buf->new_ea),
601 lengthDXD(&ea_buf->new_ea));
605 static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf,
608 struct jfs_inode_info *ji = JFS_IP(inode);
609 unsigned long old_blocks, new_blocks;
613 ea_release(inode, ea_buf);
615 } else if (ea_buf->flag & EA_INLINE) {
616 assert(new_size <= sizeof (ji->i_inline_ea));
617 ji->mode2 &= ~INLINEEA;
618 ea_buf->new_ea.flag = DXD_INLINE;
619 DXDsize(&ea_buf->new_ea, new_size);
620 DXDaddress(&ea_buf->new_ea, 0);
621 DXDlength(&ea_buf->new_ea, 0);
622 } else if (ea_buf->flag & EA_MALLOC) {
623 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
624 kfree(ea_buf->xattr);
625 } else if (ea_buf->flag & EA_NEW) {
626 /* We have already allocated a new dxd */
627 flush_metapage(ea_buf->mp);
629 /* ->xattr must point to original ea's metapage */
630 rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea);
631 discard_metapage(ea_buf->mp);
636 old_blocks = new_blocks = 0;
638 if (ji->ea.flag & DXD_EXTENT) {
639 invalidate_dxd_metapages(inode, ji->ea);
640 old_blocks = lengthDXD(&ji->ea);
644 txEA(tid, inode, &ji->ea, &ea_buf->new_ea);
645 if (ea_buf->new_ea.flag & DXD_EXTENT) {
646 new_blocks = lengthDXD(&ea_buf->new_ea);
647 if (ji->ea.flag & DXD_INLINE)
648 ji->mode2 |= INLINEEA;
650 ji->ea = ea_buf->new_ea;
652 txEA(tid, inode, &ji->ea, NULL);
653 if (ji->ea.flag & DXD_INLINE)
654 ji->mode2 |= INLINEEA;
659 /* If old blocks exist, they must be removed from quota allocation. */
661 dquot_free_block(inode, old_blocks);
663 inode->i_ctime = CURRENT_TIME;
669 * Most of the permission checking is done by xattr_permission in the vfs.
670 * We also need to verify that this is a namespace that we recognize.
672 static int can_set_xattr(struct inode *inode, const char *name,
673 const void *value, size_t value_len)
675 if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
677 * This makes sure that we aren't trying to set an
678 * attribute in a different namespace by prefixing it
681 if (is_known_namespace(name + XATTR_OS2_PREFIX_LEN))
687 * Don't allow setting an attribute in an unknown namespace.
689 if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
690 strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
691 strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
697 int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name,
698 const void *value, size_t value_len, int flags)
700 struct jfs_ea_list *ealist;
701 struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL;
702 struct ea_buffer ea_buf;
706 int namelen = strlen(name);
707 char *os2name = NULL;
712 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
713 os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
717 strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
719 namelen -= XATTR_OS2_PREFIX_LEN;
722 down_write(&JFS_IP(inode)->xattr_sem);
724 xattr_size = ea_get(inode, &ea_buf, 0);
725 if (xattr_size < 0) {
731 ealist = (struct jfs_ea_list *) ea_buf.xattr;
732 new_size = sizeof (struct jfs_ea_list);
735 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist);
737 if ((namelen == ea->namelen) &&
738 (memcmp(name, ea->name, namelen) == 0)) {
740 if (flags & XATTR_CREATE) {
745 old_ea_size = EA_SIZE(ea);
746 next_ea = NEXT_EA(ea);
748 new_size += EA_SIZE(ea);
753 if (flags & XATTR_REPLACE) {
763 new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len;
765 if (new_size > ea_buf.max_size) {
767 * We need to allocate more space for merged ea list.
768 * We should only have loop to again: once.
770 ea_release(inode, &ea_buf);
771 xattr_size = ea_get(inode, &ea_buf, new_size);
772 if (xattr_size < 0) {
779 /* Remove old ea of the same name */
781 /* number of bytes following target EA */
782 length = (char *) END_EALIST(ealist) - (char *) next_ea;
784 memmove(old_ea, next_ea, length);
785 xattr_size -= old_ea_size;
788 /* Add new entry to the end */
791 /* Completely new ea list */
792 xattr_size = sizeof (struct jfs_ea_list);
795 * The size of EA value is limitted by on-disk format up to
796 * __le16, there would be an overflow if the size is equal
797 * to XATTR_SIZE_MAX (65536). In order to avoid this issue,
798 * we can pre-checkup the value size against USHRT_MAX, and
799 * return -E2BIG in this case, which is consistent with the
800 * VFS setxattr interface.
802 if (value_len >= USHRT_MAX) {
807 ea = (struct jfs_ea *) ((char *) ealist + xattr_size);
809 ea->namelen = namelen;
810 ea->valuelen = (cpu_to_le16(value_len));
811 memcpy(ea->name, name, namelen);
812 ea->name[namelen] = 0;
814 memcpy(&ea->name[namelen + 1], value, value_len);
815 xattr_size += EA_SIZE(ea);
818 /* DEBUG - If we did this right, these number match */
819 if (xattr_size != new_size) {
821 "__jfs_setxattr: xattr_size = %d, new_size = %d\n",
822 xattr_size, new_size);
829 * If we're left with an empty list, there's no ea
831 if (new_size == sizeof (struct jfs_ea_list))
834 ealist->size = cpu_to_le32(new_size);
836 rc = ea_put(tid, inode, &ea_buf, new_size);
840 ea_release(inode, &ea_buf);
842 up_write(&JFS_IP(inode)->xattr_sem);
849 int jfs_setxattr(struct dentry *dentry, const char *name, const void *value,
850 size_t value_len, int flags)
852 struct inode *inode = d_inode(dentry);
853 struct jfs_inode_info *ji = JFS_IP(inode);
858 * If this is a request for a synthetic attribute in the system.*
859 * namespace use the generic infrastructure to resolve a handler
860 * for it via sb->s_xattr.
862 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
863 return generic_setxattr(dentry, name, value, value_len, flags);
865 if ((rc = can_set_xattr(inode, name, value, value_len)))
868 if (value == NULL) { /* empty EA, do not remove */
873 tid = txBegin(inode->i_sb, 0);
874 mutex_lock(&ji->commit_mutex);
875 rc = __jfs_setxattr(tid, d_inode(dentry), name, value, value_len,
878 rc = txCommit(tid, 1, &inode, 0);
880 mutex_unlock(&ji->commit_mutex);
885 ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data,
888 struct jfs_ea_list *ealist;
890 struct ea_buffer ea_buf;
893 int namelen = strlen(name);
896 down_read(&JFS_IP(inode)->xattr_sem);
898 xattr_size = ea_get(inode, &ea_buf, 0);
900 if (xattr_size < 0) {
908 ealist = (struct jfs_ea_list *) ea_buf.xattr;
910 /* Find the named attribute */
911 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea))
912 if ((namelen == ea->namelen) &&
913 memcmp(name, ea->name, namelen) == 0) {
915 size = le16_to_cpu(ea->valuelen);
918 else if (size > buf_size) {
922 value = ((char *) &ea->name) + ea->namelen + 1;
923 memcpy(data, value, size);
929 ea_release(inode, &ea_buf);
931 up_read(&JFS_IP(inode)->xattr_sem);
936 ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data,
942 * If this is a request for a synthetic attribute in the system.*
943 * namespace use the generic infrastructure to resolve a handler
944 * for it via sb->s_xattr.
946 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
947 return generic_getxattr(dentry, name, data, buf_size);
949 if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
951 * skip past "os2." prefix
953 name += XATTR_OS2_PREFIX_LEN;
955 * Don't allow retrieving properly prefixed attributes
956 * by prepending them with "os2."
958 if (is_known_namespace(name))
962 err = __jfs_getxattr(d_inode(dentry), name, data, buf_size);
968 * No special permissions are needed to list attributes except for trusted.*
970 static inline int can_list(struct jfs_ea *ea)
972 return (strncmp(ea->name, XATTR_TRUSTED_PREFIX,
973 XATTR_TRUSTED_PREFIX_LEN) ||
974 capable(CAP_SYS_ADMIN));
977 ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size)
979 struct inode *inode = d_inode(dentry);
983 struct jfs_ea_list *ealist;
985 struct ea_buffer ea_buf;
987 down_read(&JFS_IP(inode)->xattr_sem);
989 xattr_size = ea_get(inode, &ea_buf, 0);
990 if (xattr_size < 0) {
998 ealist = (struct jfs_ea_list *) ea_buf.xattr;
1000 /* compute required size of list */
1001 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1003 size += name_size(ea) + 1;
1009 if (size > buf_size) {
1014 /* Copy attribute names to buffer */
1016 for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) {
1018 int namelen = copy_name(buffer, ea);
1019 buffer += namelen + 1;
1024 ea_release(inode, &ea_buf);
1026 up_read(&JFS_IP(inode)->xattr_sem);
1030 int jfs_removexattr(struct dentry *dentry, const char *name)
1032 struct inode *inode = d_inode(dentry);
1033 struct jfs_inode_info *ji = JFS_IP(inode);
1038 * If this is a request for a synthetic attribute in the system.*
1039 * namespace use the generic infrastructure to resolve a handler
1040 * for it via sb->s_xattr.
1042 if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
1043 return generic_removexattr(dentry, name);
1045 if ((rc = can_set_xattr(inode, name, NULL, 0)))
1048 tid = txBegin(inode->i_sb, 0);
1049 mutex_lock(&ji->commit_mutex);
1050 rc = __jfs_setxattr(tid, d_inode(dentry), name, NULL, 0, XATTR_REPLACE);
1052 rc = txCommit(tid, 1, &inode, 0);
1054 mutex_unlock(&ji->commit_mutex);
1060 * List of handlers for synthetic system.* attributes. All real ondisk
1061 * attributes are handled directly.
1063 const struct xattr_handler *jfs_xattr_handlers[] = {
1064 #ifdef CONFIG_JFS_POSIX_ACL
1065 &posix_acl_access_xattr_handler,
1066 &posix_acl_default_xattr_handler,
1072 #ifdef CONFIG_JFS_SECURITY
1073 static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
1076 const struct xattr *xattr;
1077 tid_t *tid = fs_info;
1081 for (xattr = xattr_array; xattr->name != NULL; xattr++) {
1082 name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
1083 strlen(xattr->name) + 1, GFP_NOFS);
1088 strcpy(name, XATTR_SECURITY_PREFIX);
1089 strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
1091 err = __jfs_setxattr(*tid, inode, name,
1092 xattr->value, xattr->value_len, 0);
1100 int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir,
1101 const struct qstr *qstr)
1103 return security_inode_init_security(inode, dir, qstr,
1104 &jfs_initxattrs, &tid);