2 * linux/fs/reiserfs/xattr.c
4 * Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com>
9 * In order to implement EA/ACLs in a clean, backwards compatible manner,
10 * they are implemented as files in a "private" directory.
11 * Each EA is in it's own file, with the directory layout like so (/ is assumed
12 * to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory,
13 * directories named using the capital-hex form of the objectid and
14 * generation number are used. Inside each directory are individual files
15 * named with the name of the extended attribute.
17 * So, for objectid 12648430, we could have:
18 * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access
19 * /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default
20 * /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type
23 * The file contents are the text of the EA. The size is known based on the
24 * stat data describing the file.
26 * In the case of system.posix_acl_access and system.posix_acl_default, since
27 * these are special cases for filesystem ACLs, they are interpreted by the
28 * kernel, in addition, they are negatively and positively cached and attached
29 * to the inode so that unnecessary lookups are avoided.
31 * Locking works like so:
32 * Directory components (xattr root, xattr dir) are protectd by their i_mutex.
33 * The xattrs themselves are protected by the xattr_sem.
36 #include <linux/reiserfs_fs.h>
37 #include <linux/capability.h>
38 #include <linux/dcache.h>
39 #include <linux/namei.h>
40 #include <linux/errno.h>
42 #include <linux/file.h>
43 #include <linux/pagemap.h>
44 #include <linux/xattr.h>
45 #include <linux/reiserfs_xattr.h>
46 #include <linux/reiserfs_acl.h>
47 #include <asm/uaccess.h>
48 #include <net/checksum.h>
49 #include <linux/stat.h>
50 #include <linux/quotaops.h>
51 #include <linux/security.h>
53 #define PRIVROOT_NAME ".reiserfs_priv"
54 #define XAROOT_NAME "xattrs"
57 /* Helpers for inode ops. We do this so that we don't have all the VFS
58 * overhead and also for proper i_mutex annotation.
59 * dir->i_mutex must be held for all of them. */
60 #ifdef CONFIG_REISERFS_FS_XATTR
61 static int xattr_create(struct inode
*dir
, struct dentry
*dentry
, int mode
)
63 BUG_ON(!mutex_is_locked(&dir
->i_mutex
));
64 return dir
->i_op
->create(dir
, dentry
, mode
, NULL
);
68 static int xattr_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
70 BUG_ON(!mutex_is_locked(&dir
->i_mutex
));
71 return dir
->i_op
->mkdir(dir
, dentry
, mode
);
74 /* We use I_MUTEX_CHILD here to silence lockdep. It's safe because xattr
75 * mutation ops aren't called during rename or splace, which are the
76 * only other users of I_MUTEX_CHILD. It violates the ordering, but that's
77 * better than allocating another subclass just for this code. */
78 static int xattr_unlink(struct inode
*dir
, struct dentry
*dentry
)
81 BUG_ON(!mutex_is_locked(&dir
->i_mutex
));
83 reiserfs_mutex_lock_nested_safe(&dentry
->d_inode
->i_mutex
,
84 I_MUTEX_CHILD
, dir
->i_sb
);
85 error
= dir
->i_op
->unlink(dir
, dentry
);
86 mutex_unlock(&dentry
->d_inode
->i_mutex
);
93 static int xattr_rmdir(struct inode
*dir
, struct dentry
*dentry
)
96 BUG_ON(!mutex_is_locked(&dir
->i_mutex
));
98 reiserfs_mutex_lock_nested_safe(&dentry
->d_inode
->i_mutex
,
99 I_MUTEX_CHILD
, dir
->i_sb
);
100 dentry_unhash(dentry
);
101 error
= dir
->i_op
->rmdir(dir
, dentry
);
103 dentry
->d_inode
->i_flags
|= S_DEAD
;
104 mutex_unlock(&dentry
->d_inode
->i_mutex
);
112 #define xattr_may_create(flags) (!flags || flags & XATTR_CREATE)
114 static struct dentry
*open_xa_root(struct super_block
*sb
, int flags
)
116 struct dentry
*privroot
= REISERFS_SB(sb
)->priv_root
;
117 struct dentry
*xaroot
;
118 if (!privroot
->d_inode
)
119 return ERR_PTR(-ENODATA
);
121 mutex_lock_nested(&privroot
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
123 xaroot
= dget(REISERFS_SB(sb
)->xattr_root
);
125 xaroot
= ERR_PTR(-ENODATA
);
126 else if (!xaroot
->d_inode
) {
128 if (xattr_may_create(flags
))
129 err
= xattr_mkdir(privroot
->d_inode
, xaroot
, 0700);
132 xaroot
= ERR_PTR(err
);
136 mutex_unlock(&privroot
->d_inode
->i_mutex
);
140 static struct dentry
*open_xa_dir(const struct inode
*inode
, int flags
)
142 struct dentry
*xaroot
, *xadir
;
145 xaroot
= open_xa_root(inode
->i_sb
, flags
);
149 snprintf(namebuf
, sizeof(namebuf
), "%X.%X",
150 le32_to_cpu(INODE_PKEY(inode
)->k_objectid
),
151 inode
->i_generation
);
153 mutex_lock_nested(&xaroot
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
155 xadir
= lookup_one_len(namebuf
, xaroot
, strlen(namebuf
));
156 if (!IS_ERR(xadir
) && !xadir
->d_inode
) {
158 if (xattr_may_create(flags
))
159 err
= xattr_mkdir(xaroot
->d_inode
, xadir
, 0700);
162 xadir
= ERR_PTR(err
);
166 mutex_unlock(&xaroot
->d_inode
->i_mutex
);
171 /* The following are side effects of other operations that aren't explicitly
172 * modifying extended attributes. This includes operations such as permissions
173 * or ownership changes, object deletions, etc. */
174 struct reiserfs_dentry_buf
{
175 struct dentry
*xadir
;
177 struct dentry
*dentries
[8];
181 fill_with_dentries(void *buf
, const char *name
, int namelen
, loff_t offset
,
182 u64 ino
, unsigned int d_type
)
184 struct reiserfs_dentry_buf
*dbuf
= buf
;
185 struct dentry
*dentry
;
186 WARN_ON_ONCE(!mutex_is_locked(&dbuf
->xadir
->d_inode
->i_mutex
));
188 if (dbuf
->count
== ARRAY_SIZE(dbuf
->dentries
))
191 if (name
[0] == '.' && (name
[1] == '\0' ||
192 (name
[1] == '.' && name
[2] == '\0')))
195 dentry
= lookup_one_len(name
, dbuf
->xadir
, namelen
);
196 if (IS_ERR(dentry
)) {
197 return PTR_ERR(dentry
);
198 } else if (!dentry
->d_inode
) {
199 /* A directory entry exists, but no file? */
200 reiserfs_error(dentry
->d_sb
, "xattr-20003",
201 "Corrupted directory: xattr %s listed but "
202 "not found for file %s.\n",
203 dentry
->d_name
.name
, dbuf
->xadir
->d_name
.name
);
208 dbuf
->dentries
[dbuf
->count
++] = dentry
;
213 cleanup_dentry_buf(struct reiserfs_dentry_buf
*buf
)
216 for (i
= 0; i
< buf
->count
; i
++)
217 if (buf
->dentries
[i
])
218 dput(buf
->dentries
[i
]);
221 static int reiserfs_for_each_xattr(struct inode
*inode
,
222 int (*action
)(struct dentry
*, void *),
228 struct reiserfs_dentry_buf buf
= {
232 /* Skip out, an xattr has no xattrs associated with it */
233 if (IS_PRIVATE(inode
) || get_inode_sd_version(inode
) == STAT_DATA_V1
)
236 reiserfs_write_unlock(inode
->i_sb
);
237 dir
= open_xa_dir(inode
, XATTR_REPLACE
);
240 reiserfs_write_lock(inode
->i_sb
);
242 } else if (!dir
->d_inode
) {
244 reiserfs_write_lock(inode
->i_sb
);
248 mutex_lock_nested(&dir
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
250 reiserfs_write_lock(inode
->i_sb
);
253 err
= reiserfs_readdir_dentry(dir
, &buf
, fill_with_dentries
, &pos
);
254 while ((err
== 0 || err
== -ENOSPC
) && buf
.count
) {
257 for (i
= 0; i
< buf
.count
&& buf
.dentries
[i
]; i
++) {
259 struct dentry
*dentry
= buf
.dentries
[i
];
261 if (err
== 0 && !S_ISDIR(dentry
->d_inode
->i_mode
))
262 lerr
= action(dentry
, data
);
265 buf
.dentries
[i
] = NULL
;
270 err
= reiserfs_readdir_dentry(dir
, &buf
,
271 fill_with_dentries
, &pos
);
273 mutex_unlock(&dir
->d_inode
->i_mutex
);
275 /* Clean up after a failed readdir */
276 cleanup_dentry_buf(&buf
);
279 /* We start a transaction here to avoid a ABBA situation
280 * between the xattr root's i_mutex and the journal lock.
281 * This doesn't incur much additional overhead since the
282 * new transaction will just nest inside the
283 * outer transaction. */
284 int blocks
= JOURNAL_PER_BALANCE_CNT
* 2 + 2 +
285 4 * REISERFS_QUOTA_TRANS_BLOCKS(inode
->i_sb
);
286 struct reiserfs_transaction_handle th
;
287 err
= journal_begin(&th
, inode
->i_sb
, blocks
);
290 reiserfs_mutex_lock_nested_safe(
291 &dir
->d_parent
->d_inode
->i_mutex
,
292 I_MUTEX_XATTR
, inode
->i_sb
);
293 err
= action(dir
, data
);
294 jerror
= journal_end(&th
, inode
->i_sb
, blocks
);
295 mutex_unlock(&dir
->d_parent
->d_inode
->i_mutex
);
302 /* -ENODATA isn't an error */
308 static int delete_one_xattr(struct dentry
*dentry
, void *data
)
310 struct inode
*dir
= dentry
->d_parent
->d_inode
;
312 /* This is the xattr dir, handle specially. */
313 if (S_ISDIR(dentry
->d_inode
->i_mode
))
314 return xattr_rmdir(dir
, dentry
);
316 return xattr_unlink(dir
, dentry
);
319 static int chown_one_xattr(struct dentry
*dentry
, void *data
)
321 struct iattr
*attrs
= data
;
322 return reiserfs_setattr(dentry
, attrs
);
325 /* No i_mutex, but the inode is unconnected. */
326 int reiserfs_delete_xattrs(struct inode
*inode
)
328 int err
= reiserfs_for_each_xattr(inode
, delete_one_xattr
, NULL
);
330 reiserfs_warning(inode
->i_sb
, "jdm-20004",
331 "Couldn't delete all xattrs (%d)\n", err
);
335 /* inode->i_mutex: down */
336 int reiserfs_chown_xattrs(struct inode
*inode
, struct iattr
*attrs
)
338 int err
= reiserfs_for_each_xattr(inode
, chown_one_xattr
, attrs
);
340 reiserfs_warning(inode
->i_sb
, "jdm-20007",
341 "Couldn't chown all xattrs (%d)\n", err
);
345 #ifdef CONFIG_REISERFS_FS_XATTR
346 /* Returns a dentry corresponding to a specific extended attribute file
347 * for the inode. If flags allow, the file is created. Otherwise, a
348 * valid or negative dentry, or an error is returned. */
349 static struct dentry
*xattr_lookup(struct inode
*inode
, const char *name
,
352 struct dentry
*xadir
, *xafile
;
355 xadir
= open_xa_dir(inode
, flags
);
357 return ERR_CAST(xadir
);
359 mutex_lock_nested(&xadir
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
360 xafile
= lookup_one_len(name
, xadir
, strlen(name
));
361 if (IS_ERR(xafile
)) {
362 err
= PTR_ERR(xafile
);
366 if (xafile
->d_inode
&& (flags
& XATTR_CREATE
))
369 if (!xafile
->d_inode
) {
371 if (xattr_may_create(flags
))
372 err
= xattr_create(xadir
->d_inode
, xafile
,
379 mutex_unlock(&xadir
->d_inode
->i_mutex
);
386 /* Internal operations on file data */
387 static inline void reiserfs_put_page(struct page
*page
)
390 page_cache_release(page
);
393 static struct page
*reiserfs_get_page(struct inode
*dir
, size_t n
)
395 struct address_space
*mapping
= dir
->i_mapping
;
397 /* We can deadlock if we try to free dentries,
398 and an unlink/rmdir has just occured - GFP_NOFS avoids this */
399 mapping_set_gfp_mask(mapping
, GFP_NOFS
);
400 page
= read_mapping_page(mapping
, n
>> PAGE_CACHE_SHIFT
, NULL
);
409 reiserfs_put_page(page
);
410 return ERR_PTR(-EIO
);
413 static inline __u32
xattr_hash(const char *msg
, int len
)
415 return csum_partial(msg
, len
, 0);
418 int reiserfs_commit_write(struct file
*f
, struct page
*page
,
419 unsigned from
, unsigned to
);
420 int reiserfs_prepare_write(struct file
*f
, struct page
*page
,
421 unsigned from
, unsigned to
);
423 static void update_ctime(struct inode
*inode
)
425 struct timespec now
= current_fs_time(inode
->i_sb
);
426 if (hlist_unhashed(&inode
->i_hash
) || !inode
->i_nlink
||
427 timespec_equal(&inode
->i_ctime
, &now
))
430 inode
->i_ctime
= CURRENT_TIME_SEC
;
431 mark_inode_dirty(inode
);
434 static int lookup_and_delete_xattr(struct inode
*inode
, const char *name
)
437 struct dentry
*dentry
, *xadir
;
439 xadir
= open_xa_dir(inode
, XATTR_REPLACE
);
441 return PTR_ERR(xadir
);
443 mutex_lock_nested(&xadir
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
444 dentry
= lookup_one_len(name
, xadir
, strlen(name
));
445 if (IS_ERR(dentry
)) {
446 err
= PTR_ERR(dentry
);
450 if (dentry
->d_inode
) {
451 reiserfs_write_lock(inode
->i_sb
);
452 err
= xattr_unlink(xadir
->d_inode
, dentry
);
453 reiserfs_write_unlock(inode
->i_sb
);
459 mutex_unlock(&xadir
->d_inode
->i_mutex
);
465 /* Generic extended attribute operations that can be used by xa plugins */
468 * inode->i_mutex: down
471 reiserfs_xattr_set_handle(struct reiserfs_transaction_handle
*th
,
472 struct inode
*inode
, const char *name
,
473 const void *buffer
, size_t buffer_size
, int flags
)
476 struct dentry
*dentry
;
480 size_t buffer_pos
= 0;
484 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
487 reiserfs_write_unlock(inode
->i_sb
);
490 err
= lookup_and_delete_xattr(inode
, name
);
491 reiserfs_write_lock(inode
->i_sb
);
495 dentry
= xattr_lookup(inode
, name
, flags
);
496 if (IS_ERR(dentry
)) {
497 reiserfs_write_lock(inode
->i_sb
);
498 return PTR_ERR(dentry
);
501 down_write(&REISERFS_I(inode
)->i_xattr_sem
);
503 reiserfs_write_lock(inode
->i_sb
);
505 xahash
= xattr_hash(buffer
, buffer_size
);
506 while (buffer_pos
< buffer_size
|| buffer_pos
== 0) {
509 size_t page_offset
= (file_pos
& (PAGE_CACHE_SIZE
- 1));
510 if (buffer_size
- buffer_pos
> PAGE_CACHE_SIZE
)
511 chunk
= PAGE_CACHE_SIZE
;
513 chunk
= buffer_size
- buffer_pos
;
515 page
= reiserfs_get_page(dentry
->d_inode
, file_pos
);
522 data
= page_address(page
);
525 struct reiserfs_xattr_header
*rxh
;
526 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
527 if (chunk
+ skip
> PAGE_CACHE_SIZE
)
528 chunk
= PAGE_CACHE_SIZE
- skip
;
529 rxh
= (struct reiserfs_xattr_header
*)data
;
530 rxh
->h_magic
= cpu_to_le32(REISERFS_XATTR_MAGIC
);
531 rxh
->h_hash
= cpu_to_le32(xahash
);
534 err
= reiserfs_prepare_write(NULL
, page
, page_offset
,
535 page_offset
+ chunk
+ skip
);
538 memcpy(data
+ skip
, buffer
+ buffer_pos
, chunk
);
539 err
= reiserfs_commit_write(NULL
, page
, page_offset
,
540 page_offset
+ chunk
+
544 reiserfs_put_page(page
);
548 if (err
|| buffer_size
== 0 || !buffer
)
552 new_size
= buffer_size
+ sizeof(struct reiserfs_xattr_header
);
553 if (!err
&& new_size
< i_size_read(dentry
->d_inode
)) {
554 struct iattr newattrs
= {
555 .ia_ctime
= current_fs_time(inode
->i_sb
),
556 .ia_size
= buffer_size
,
557 .ia_valid
= ATTR_SIZE
| ATTR_CTIME
,
560 reiserfs_write_unlock(inode
->i_sb
);
561 mutex_lock_nested(&dentry
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
562 down_write(&dentry
->d_inode
->i_alloc_sem
);
563 reiserfs_write_lock(inode
->i_sb
);
565 err
= reiserfs_setattr(dentry
, &newattrs
);
566 up_write(&dentry
->d_inode
->i_alloc_sem
);
567 mutex_unlock(&dentry
->d_inode
->i_mutex
);
571 up_write(&REISERFS_I(inode
)->i_xattr_sem
);
576 /* We need to start a transaction to maintain lock ordering */
577 int reiserfs_xattr_set(struct inode
*inode
, const char *name
,
578 const void *buffer
, size_t buffer_size
, int flags
)
581 struct reiserfs_transaction_handle th
;
583 size_t jbegin_count
= reiserfs_xattr_nblocks(inode
, buffer_size
);
585 if (!(flags
& XATTR_REPLACE
))
586 jbegin_count
+= reiserfs_xattr_jcreate_nblocks(inode
);
588 reiserfs_write_lock(inode
->i_sb
);
589 error
= journal_begin(&th
, inode
->i_sb
, jbegin_count
);
591 reiserfs_write_unlock(inode
->i_sb
);
595 error
= reiserfs_xattr_set_handle(&th
, inode
, name
,
596 buffer
, buffer_size
, flags
);
598 error2
= journal_end(&th
, inode
->i_sb
, jbegin_count
);
601 reiserfs_write_unlock(inode
->i_sb
);
607 * inode->i_mutex: down
610 reiserfs_xattr_get(struct inode
*inode
, const char *name
, void *buffer
,
614 struct dentry
*dentry
;
617 size_t buffer_pos
= 0;
624 /* We can't have xattrs attached to v1 items since they don't have
625 * generation numbers */
626 if (get_inode_sd_version(inode
) == STAT_DATA_V1
)
629 dentry
= xattr_lookup(inode
, name
, XATTR_REPLACE
);
630 if (IS_ERR(dentry
)) {
631 err
= PTR_ERR(dentry
);
635 down_read(&REISERFS_I(inode
)->i_xattr_sem
);
637 isize
= i_size_read(dentry
->d_inode
);
639 /* Just return the size needed */
640 if (buffer
== NULL
) {
641 err
= isize
- sizeof(struct reiserfs_xattr_header
);
645 if (buffer_size
< isize
- sizeof(struct reiserfs_xattr_header
)) {
650 while (file_pos
< isize
) {
654 if (isize
- file_pos
> PAGE_CACHE_SIZE
)
655 chunk
= PAGE_CACHE_SIZE
;
657 chunk
= isize
- file_pos
;
659 page
= reiserfs_get_page(dentry
->d_inode
, file_pos
);
666 data
= page_address(page
);
668 struct reiserfs_xattr_header
*rxh
=
669 (struct reiserfs_xattr_header
*)data
;
670 skip
= file_pos
= sizeof(struct reiserfs_xattr_header
);
672 /* Magic doesn't match up.. */
673 if (rxh
->h_magic
!= cpu_to_le32(REISERFS_XATTR_MAGIC
)) {
675 reiserfs_put_page(page
);
676 reiserfs_warning(inode
->i_sb
, "jdm-20001",
677 "Invalid magic for xattr (%s) "
678 "associated with %k", name
,
683 hash
= le32_to_cpu(rxh
->h_hash
);
685 memcpy(buffer
+ buffer_pos
, data
+ skip
, chunk
);
687 reiserfs_put_page(page
);
692 err
= isize
- sizeof(struct reiserfs_xattr_header
);
694 if (xattr_hash(buffer
, isize
- sizeof(struct reiserfs_xattr_header
)) !=
696 reiserfs_warning(inode
->i_sb
, "jdm-20002",
697 "Invalid hash for xattr (%s) associated "
698 "with %k", name
, INODE_PKEY(inode
));
703 up_read(&REISERFS_I(inode
)->i_xattr_sem
);
711 * In order to implement different sets of xattr operations for each xattr
712 * prefix with the generic xattr API, a filesystem should create a
713 * null-terminated array of struct xattr_handler (one for each prefix) and
714 * hang a pointer to it off of the s_xattr field of the superblock.
716 * The generic_fooxattr() functions will use this list to dispatch xattr
717 * operations to the correct xattr_handler.
719 #define for_each_xattr_handler(handlers, handler) \
720 for ((handler) = *(handlers)++; \
722 (handler) = *(handlers)++)
724 /* This is the implementation for the xattr plugin infrastructure */
725 static inline struct xattr_handler
*
726 find_xattr_handler_prefix(struct xattr_handler
**handlers
,
729 struct xattr_handler
*xah
;
734 for_each_xattr_handler(handlers
, xah
) {
735 if (strncmp(xah
->prefix
, name
, strlen(xah
->prefix
)) == 0)
744 * Inode operation getxattr()
747 reiserfs_getxattr(struct dentry
* dentry
, const char *name
, void *buffer
,
750 struct xattr_handler
*handler
;
752 handler
= find_xattr_handler_prefix(dentry
->d_sb
->s_xattr
, name
);
754 if (!handler
|| get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
757 return handler
->get(dentry
, name
, buffer
, size
, handler
->flags
);
761 * Inode operation setxattr()
763 * dentry->d_inode->i_mutex down
766 reiserfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
767 size_t size
, int flags
)
769 struct xattr_handler
*handler
;
771 handler
= find_xattr_handler_prefix(dentry
->d_sb
->s_xattr
, name
);
773 if (!handler
|| get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
776 return handler
->set(dentry
, name
, value
, size
, flags
, handler
->flags
);
780 * Inode operation removexattr()
782 * dentry->d_inode->i_mutex down
784 int reiserfs_removexattr(struct dentry
*dentry
, const char *name
)
786 struct xattr_handler
*handler
;
787 handler
= find_xattr_handler_prefix(dentry
->d_sb
->s_xattr
, name
);
789 if (!handler
|| get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
792 return handler
->set(dentry
, name
, NULL
, 0, XATTR_REPLACE
, handler
->flags
);
795 struct listxattr_buf
{
799 struct dentry
*dentry
;
802 static int listxattr_filler(void *buf
, const char *name
, int namelen
,
803 loff_t offset
, u64 ino
, unsigned int d_type
)
805 struct listxattr_buf
*b
= (struct listxattr_buf
*)buf
;
807 if (name
[0] != '.' ||
808 (namelen
!= 1 && (name
[1] != '.' || namelen
!= 2))) {
809 struct xattr_handler
*handler
;
810 handler
= find_xattr_handler_prefix(b
->dentry
->d_sb
->s_xattr
,
812 if (!handler
) /* Unsupported xattr name */
815 size
= handler
->list(b
->dentry
, b
->buf
+ b
->pos
,
816 b
->size
, name
, namelen
,
821 size
= handler
->list(b
->dentry
, NULL
, 0, name
,
822 namelen
, handler
->flags
);
831 * Inode operation listxattr()
833 * We totally ignore the generic listxattr here because it would be stupid
834 * not to. Since the xattrs are organized in a directory, we can just
835 * readdir to find them.
837 ssize_t
reiserfs_listxattr(struct dentry
* dentry
, char *buffer
, size_t size
)
842 struct listxattr_buf buf
= {
845 .size
= buffer
? size
: 0,
848 if (!dentry
->d_inode
)
851 if (!dentry
->d_sb
->s_xattr
||
852 get_inode_sd_version(dentry
->d_inode
) == STAT_DATA_V1
)
855 dir
= open_xa_dir(dentry
->d_inode
, XATTR_REPLACE
);
859 err
= 0; /* Not an error if there aren't any xattrs */
863 mutex_lock_nested(&dir
->d_inode
->i_mutex
, I_MUTEX_XATTR
);
864 err
= reiserfs_readdir_dentry(dir
, &buf
, listxattr_filler
, &pos
);
865 mutex_unlock(&dir
->d_inode
->i_mutex
);
875 static int reiserfs_check_acl(struct inode
*inode
, int mask
)
877 struct posix_acl
*acl
;
878 int error
= -EAGAIN
; /* do regular unix permission checks by default */
880 acl
= reiserfs_get_acl(inode
, ACL_TYPE_ACCESS
);
884 error
= posix_acl_permission(inode
, acl
, mask
);
885 posix_acl_release(acl
);
886 } else if (PTR_ERR(acl
) != -ENODATA
)
887 error
= PTR_ERR(acl
);
893 static int create_privroot(struct dentry
*dentry
)
896 struct inode
*inode
= dentry
->d_parent
->d_inode
;
897 WARN_ON_ONCE(!mutex_is_locked(&inode
->i_mutex
));
899 err
= xattr_mkdir(inode
, dentry
, 0700);
900 if (err
|| !dentry
->d_inode
) {
901 reiserfs_warning(dentry
->d_sb
, "jdm-20006",
902 "xattrs/ACLs enabled and couldn't "
903 "find/create .reiserfs_priv. "
908 dentry
->d_inode
->i_flags
|= S_PRIVATE
;
909 reiserfs_info(dentry
->d_sb
, "Created %s - reserved for xattr "
910 "storage.\n", PRIVROOT_NAME
);
916 int __init
reiserfs_xattr_register_handlers(void) { return 0; }
917 void reiserfs_xattr_unregister_handlers(void) {}
918 static int create_privroot(struct dentry
*dentry
) { return 0; }
921 /* Actual operations that are exported to VFS-land */
922 struct xattr_handler
*reiserfs_xattr_handlers
[] = {
923 #ifdef CONFIG_REISERFS_FS_XATTR
924 &reiserfs_xattr_user_handler
,
925 &reiserfs_xattr_trusted_handler
,
927 #ifdef CONFIG_REISERFS_FS_SECURITY
928 &reiserfs_xattr_security_handler
,
930 #ifdef CONFIG_REISERFS_FS_POSIX_ACL
931 &reiserfs_posix_acl_access_handler
,
932 &reiserfs_posix_acl_default_handler
,
937 static int xattr_mount_check(struct super_block
*s
)
939 /* We need generation numbers to ensure that the oid mapping is correct
940 * v3.5 filesystems don't have them. */
941 if (old_format_only(s
)) {
942 if (reiserfs_xattrs_optional(s
)) {
943 /* Old format filesystem, but optional xattrs have
944 * been enabled. Error out. */
945 reiserfs_warning(s
, "jdm-2005",
946 "xattrs/ACLs not supported "
947 "on pre-v3.6 format filesystems. "
956 int reiserfs_permission(struct inode
*inode
, int mask
)
959 * We don't do permission checks on the internal objects.
960 * Permissions are determined by the "owning" object.
962 if (IS_PRIVATE(inode
))
965 #ifdef CONFIG_REISERFS_FS_XATTR
967 * Stat data v1 doesn't support ACLs.
969 if (get_inode_sd_version(inode
) != STAT_DATA_V1
)
970 return generic_permission(inode
, mask
, reiserfs_check_acl
);
972 return generic_permission(inode
, mask
, NULL
);
975 /* This will catch lookups from the fs root to .reiserfs_priv */
977 xattr_lookup_poison(struct dentry
*dentry
, struct qstr
*q1
, struct qstr
*name
)
979 struct dentry
*priv_root
= REISERFS_SB(dentry
->d_sb
)->priv_root
;
980 if (container_of(q1
, struct dentry
, d_name
) == priv_root
)
982 if (q1
->len
== name
->len
&&
983 !memcmp(q1
->name
, name
->name
, name
->len
))
988 static const struct dentry_operations xattr_lookup_poison_ops
= {
989 .d_compare
= xattr_lookup_poison
,
992 int reiserfs_lookup_privroot(struct super_block
*s
)
994 struct dentry
*dentry
;
997 /* If we don't have the privroot located yet - go find it */
998 reiserfs_mutex_lock_safe(&s
->s_root
->d_inode
->i_mutex
, s
);
999 dentry
= lookup_one_len(PRIVROOT_NAME
, s
->s_root
,
1000 strlen(PRIVROOT_NAME
));
1001 if (!IS_ERR(dentry
)) {
1002 REISERFS_SB(s
)->priv_root
= dentry
;
1003 if (!reiserfs_expose_privroot(s
))
1004 s
->s_root
->d_op
= &xattr_lookup_poison_ops
;
1005 if (dentry
->d_inode
)
1006 dentry
->d_inode
->i_flags
|= S_PRIVATE
;
1008 err
= PTR_ERR(dentry
);
1009 mutex_unlock(&s
->s_root
->d_inode
->i_mutex
);
1014 /* We need to take a copy of the mount flags since things like
1015 * MS_RDONLY don't get set until *after* we're called.
1016 * mount_flags != mount_options */
1017 int reiserfs_xattr_init(struct super_block
*s
, int mount_flags
)
1020 struct dentry
*privroot
= REISERFS_SB(s
)->priv_root
;
1022 err
= xattr_mount_check(s
);
1026 if (!privroot
->d_inode
&& !(mount_flags
& MS_RDONLY
)) {
1027 reiserfs_mutex_lock_safe(&s
->s_root
->d_inode
->i_mutex
, s
);
1028 err
= create_privroot(REISERFS_SB(s
)->priv_root
);
1029 mutex_unlock(&s
->s_root
->d_inode
->i_mutex
);
1032 if (privroot
->d_inode
) {
1033 s
->s_xattr
= reiserfs_xattr_handlers
;
1034 reiserfs_mutex_lock_safe(&privroot
->d_inode
->i_mutex
, s
);
1035 if (!REISERFS_SB(s
)->xattr_root
) {
1036 struct dentry
*dentry
;
1037 dentry
= lookup_one_len(XAROOT_NAME
, privroot
,
1038 strlen(XAROOT_NAME
));
1039 if (!IS_ERR(dentry
))
1040 REISERFS_SB(s
)->xattr_root
= dentry
;
1042 err
= PTR_ERR(dentry
);
1044 mutex_unlock(&privroot
->d_inode
->i_mutex
);
1049 clear_bit(REISERFS_XATTRS_USER
, &(REISERFS_SB(s
)->s_mount_opt
));
1050 clear_bit(REISERFS_POSIXACL
, &(REISERFS_SB(s
)->s_mount_opt
));
1053 /* The super_block MS_POSIXACL must mirror the (no)acl mount option. */
1054 if (reiserfs_posixacl(s
))
1055 s
->s_flags
|= MS_POSIXACL
;
1057 s
->s_flags
&= ~MS_POSIXACL
;