4 Extended attribute handling.
6 Copyright (C) 2001 by Andreas Gruenbacher <a.gruenbacher@computer.org>
7 Copyright (C) 2001 SGI - Silicon Graphics, Inc <linux-xfs@oss.sgi.com>
8 Copyright (c) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
11 #include <linux/slab.h>
12 #include <linux/file.h>
13 #include <linux/xattr.h>
14 #include <linux/mount.h>
15 #include <linux/namei.h>
16 #include <linux/security.h>
17 #include <linux/evm.h>
18 #include <linux/syscalls.h>
19 #include <linux/export.h>
20 #include <linux/fsnotify.h>
21 #include <linux/audit.h>
22 #include <linux/vmalloc.h>
23 #include <linux/posix_acl_xattr.h>
25 #include <linux/uaccess.h>
28 strcmp_prefix(const char *a
, const char *a_prefix
)
30 while (*a_prefix
&& *a
== *a_prefix
) {
34 return *a_prefix
? NULL
: a
;
38 * In order to implement different sets of xattr operations for each xattr
39 * prefix, a filesystem should create a null-terminated array of struct
40 * xattr_handler (one for each prefix) and hang a pointer to it off of the
41 * s_xattr field of the superblock.
43 #define for_each_xattr_handler(handlers, handler) \
45 for ((handler) = *(handlers)++; \
47 (handler) = *(handlers)++)
50 * Find the xattr_handler with the matching prefix.
52 static const struct xattr_handler
*
53 xattr_resolve_name(struct inode
*inode
, const char **name
)
55 const struct xattr_handler
**handlers
= inode
->i_sb
->s_xattr
;
56 const struct xattr_handler
*handler
;
58 if (!(inode
->i_opflags
& IOP_XATTR
)) {
59 if (unlikely(is_bad_inode(inode
)))
61 return ERR_PTR(-EOPNOTSUPP
);
63 for_each_xattr_handler(handlers
, handler
) {
66 n
= strcmp_prefix(*name
, xattr_prefix(handler
));
68 if (!handler
->prefix
^ !*n
) {
71 return ERR_PTR(-EINVAL
);
77 return ERR_PTR(-EOPNOTSUPP
);
81 * Check permissions for extended attribute access. This is a bit complicated
82 * because different namespaces have very different rules.
85 xattr_permission(struct inode
*inode
, const char *name
, int mask
)
88 * We can never set or remove an extended attribute on a read-only
89 * filesystem or on an immutable / append-only inode.
91 if (mask
& MAY_WRITE
) {
92 if (IS_IMMUTABLE(inode
) || IS_APPEND(inode
))
95 * Updating an xattr will likely cause i_uid and i_gid
96 * to be writen back improperly if their true value is
99 if (HAS_UNMAPPED_ID(inode
))
104 * No restriction for security.* and system.* from the VFS. Decision
105 * on these is left to the underlying filesystem / security module.
107 if (!strncmp(name
, XATTR_SECURITY_PREFIX
, XATTR_SECURITY_PREFIX_LEN
) ||
108 !strncmp(name
, XATTR_SYSTEM_PREFIX
, XATTR_SYSTEM_PREFIX_LEN
))
112 * The trusted.* namespace can only be accessed by privileged users.
114 if (!strncmp(name
, XATTR_TRUSTED_PREFIX
, XATTR_TRUSTED_PREFIX_LEN
)) {
115 if (!capable(CAP_SYS_ADMIN
))
116 return (mask
& MAY_WRITE
) ? -EPERM
: -ENODATA
;
121 * In the user.* namespace, only regular files and directories can have
122 * extended attributes. For sticky directories, only the owner and
123 * privileged users can write attributes.
125 if (!strncmp(name
, XATTR_USER_PREFIX
, XATTR_USER_PREFIX_LEN
)) {
126 if (!S_ISREG(inode
->i_mode
) && !S_ISDIR(inode
->i_mode
))
127 return (mask
& MAY_WRITE
) ? -EPERM
: -ENODATA
;
128 if (S_ISDIR(inode
->i_mode
) && (inode
->i_mode
& S_ISVTX
) &&
129 (mask
& MAY_WRITE
) && !inode_owner_or_capable(inode
))
133 return inode_permission(inode
, mask
);
137 __vfs_setxattr(struct dentry
*dentry
, struct inode
*inode
, const char *name
,
138 const void *value
, size_t size
, int flags
)
140 const struct xattr_handler
*handler
;
142 handler
= xattr_resolve_name(inode
, &name
);
144 return PTR_ERR(handler
);
148 value
= ""; /* empty EA, do not remove */
149 return handler
->set(handler
, dentry
, inode
, name
, value
, size
, flags
);
151 EXPORT_SYMBOL(__vfs_setxattr
);
154 * __vfs_setxattr_noperm - perform setxattr operation without performing
157 * @dentry - object to perform setxattr on
158 * @name - xattr name to set
159 * @value - value to set @name to
160 * @size - size of @value
161 * @flags - flags to pass into filesystem operations
163 * returns the result of the internal setxattr or setsecurity operations.
165 * This function requires the caller to lock the inode's i_mutex before it
166 * is executed. It also assumes that the caller will make the appropriate
169 int __vfs_setxattr_noperm(struct dentry
*dentry
, const char *name
,
170 const void *value
, size_t size
, int flags
)
172 struct inode
*inode
= dentry
->d_inode
;
174 int issec
= !strncmp(name
, XATTR_SECURITY_PREFIX
,
175 XATTR_SECURITY_PREFIX_LEN
);
178 inode
->i_flags
&= ~S_NOSEC
;
179 if (inode
->i_opflags
& IOP_XATTR
) {
180 error
= __vfs_setxattr(dentry
, inode
, name
, value
, size
, flags
);
182 fsnotify_xattr(dentry
);
183 security_inode_post_setxattr(dentry
, name
, value
,
187 if (unlikely(is_bad_inode(inode
)))
190 if (error
== -EAGAIN
) {
194 const char *suffix
= name
+ XATTR_SECURITY_PREFIX_LEN
;
196 error
= security_inode_setsecurity(inode
, suffix
, value
,
199 fsnotify_xattr(dentry
);
205 EXPORT_SYMBOL_GPL(__vfs_setxattr_noperm
);
209 vfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
210 size_t size
, int flags
)
212 struct inode
*inode
= dentry
->d_inode
;
215 error
= xattr_permission(inode
, name
, MAY_WRITE
);
220 error
= security_inode_setxattr(dentry
, name
, value
, size
, flags
);
224 error
= __vfs_setxattr_noperm(dentry
, name
, value
, size
, flags
);
230 EXPORT_SYMBOL_GPL(vfs_setxattr
);
233 xattr_getsecurity(struct inode
*inode
, const char *name
, void *value
,
239 if (!value
|| !size
) {
240 len
= security_inode_getsecurity(inode
, name
, &buffer
, false);
244 len
= security_inode_getsecurity(inode
, name
, &buffer
, true);
251 memcpy(value
, buffer
, len
);
253 security_release_secctx(buffer
, len
);
257 EXPORT_SYMBOL_GPL(xattr_getsecurity
);
260 * vfs_getxattr_alloc - allocate memory, if necessary, before calling getxattr
262 * Allocate memory, if not already allocated, or re-allocate correct size,
263 * before retrieving the extended attribute.
265 * Returns the result of alloc, if failed, or the getxattr operation.
268 vfs_getxattr_alloc(struct dentry
*dentry
, const char *name
, char **xattr_value
,
269 size_t xattr_size
, gfp_t flags
)
271 const struct xattr_handler
*handler
;
272 struct inode
*inode
= dentry
->d_inode
;
273 char *value
= *xattr_value
;
276 error
= xattr_permission(inode
, name
, MAY_READ
);
280 handler
= xattr_resolve_name(inode
, &name
);
282 return PTR_ERR(handler
);
285 error
= handler
->get(handler
, dentry
, inode
, name
, NULL
, 0);
289 if (!value
|| (error
> xattr_size
)) {
290 value
= krealloc(*xattr_value
, error
+ 1, flags
);
293 memset(value
, 0, error
+ 1);
296 error
= handler
->get(handler
, dentry
, inode
, name
, value
, error
);
297 *xattr_value
= value
;
300 EXPORT_SYMBOL_GPL(vfs_getxattr_alloc
);
303 __vfs_getxattr(struct dentry
*dentry
, struct inode
*inode
, const char *name
,
304 void *value
, size_t size
)
306 const struct xattr_handler
*handler
;
308 handler
= xattr_resolve_name(inode
, &name
);
310 return PTR_ERR(handler
);
313 return handler
->get(handler
, dentry
, inode
, name
, value
, size
);
315 EXPORT_SYMBOL(__vfs_getxattr
);
318 vfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
, size_t size
)
320 struct inode
*inode
= dentry
->d_inode
;
323 error
= xattr_permission(inode
, name
, MAY_READ
);
327 error
= security_inode_getxattr(dentry
, name
);
331 if (!strncmp(name
, XATTR_SECURITY_PREFIX
,
332 XATTR_SECURITY_PREFIX_LEN
)) {
333 const char *suffix
= name
+ XATTR_SECURITY_PREFIX_LEN
;
334 int ret
= xattr_getsecurity(inode
, suffix
, value
, size
);
336 * Only overwrite the return value if a security module
337 * is actually active.
339 if (ret
== -EOPNOTSUPP
)
344 return __vfs_getxattr(dentry
, inode
, name
, value
, size
);
346 EXPORT_SYMBOL_GPL(vfs_getxattr
);
349 vfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
351 struct inode
*inode
= d_inode(dentry
);
354 error
= security_inode_listxattr(dentry
);
357 if (inode
->i_op
->listxattr
&& (inode
->i_opflags
& IOP_XATTR
)) {
359 error
= inode
->i_op
->listxattr(dentry
, list
, size
);
361 error
= security_inode_listsecurity(inode
, list
, size
);
362 if (size
&& error
> size
)
367 EXPORT_SYMBOL_GPL(vfs_listxattr
);
370 __vfs_removexattr(struct dentry
*dentry
, const char *name
)
372 struct inode
*inode
= d_inode(dentry
);
373 const struct xattr_handler
*handler
;
375 handler
= xattr_resolve_name(inode
, &name
);
377 return PTR_ERR(handler
);
380 return handler
->set(handler
, dentry
, inode
, name
, NULL
, 0, XATTR_REPLACE
);
382 EXPORT_SYMBOL(__vfs_removexattr
);
385 * __vfs_removexattr_noperm - perform removexattr operation without
386 * performing permission checks.
388 * @dentry - object to perform setxattr on
389 * @name - xattr name to set
391 * returns the result of the internal setxattr or setsecurity operations.
393 * This function requires the caller to lock the inode's i_mutex before it
394 * is executed. It also assumes that the caller will make the appropriate
398 __vfs_removexattr_noperm(struct dentry
*dentry
, const char *name
)
402 error
=__vfs_removexattr(dentry
, name
);
404 fsnotify_xattr(dentry
);
405 evm_inode_post_removexattr(dentry
, name
);
409 EXPORT_SYMBOL_GPL(__vfs_removexattr_noperm
);
412 vfs_removexattr(struct dentry
*dentry
, const char *name
)
414 struct inode
*inode
= dentry
->d_inode
;
417 error
= xattr_permission(inode
, name
, MAY_WRITE
);
422 error
= security_inode_removexattr(dentry
, name
);
426 error
= __vfs_removexattr_noperm(dentry
, name
);
432 EXPORT_SYMBOL_GPL(vfs_removexattr
);
436 * Extended attribute SET operations
439 setxattr(struct dentry
*d
, const char __user
*name
, const void __user
*value
,
440 size_t size
, int flags
)
444 char kname
[XATTR_NAME_MAX
+ 1];
446 if (flags
& ~(XATTR_CREATE
|XATTR_REPLACE
))
449 error
= strncpy_from_user(kname
, name
, sizeof(kname
));
450 if (error
== 0 || error
== sizeof(kname
))
456 if (size
> XATTR_SIZE_MAX
)
458 kvalue
= kmalloc(size
, GFP_KERNEL
| __GFP_NOWARN
);
460 kvalue
= vmalloc(size
);
464 if (copy_from_user(kvalue
, value
, size
)) {
468 if ((strcmp(kname
, XATTR_NAME_POSIX_ACL_ACCESS
) == 0) ||
469 (strcmp(kname
, XATTR_NAME_POSIX_ACL_DEFAULT
) == 0))
470 posix_acl_fix_xattr_from_user(kvalue
, size
);
473 error
= vfs_setxattr(d
, kname
, kvalue
, size
, flags
);
480 static int path_setxattr(const char __user
*pathname
,
481 const char __user
*name
, const void __user
*value
,
482 size_t size
, int flags
, unsigned int lookup_flags
)
487 error
= user_path_at(AT_FDCWD
, pathname
, lookup_flags
, &path
);
490 error
= mnt_want_write(path
.mnt
);
492 error
= setxattr(path
.dentry
, name
, value
, size
, flags
);
493 mnt_drop_write(path
.mnt
);
496 if (retry_estale(error
, lookup_flags
)) {
497 lookup_flags
|= LOOKUP_REVAL
;
503 SYSCALL_DEFINE5(setxattr
, const char __user
*, pathname
,
504 const char __user
*, name
, const void __user
*, value
,
505 size_t, size
, int, flags
)
507 return path_setxattr(pathname
, name
, value
, size
, flags
, LOOKUP_FOLLOW
);
510 SYSCALL_DEFINE5(lsetxattr
, const char __user
*, pathname
,
511 const char __user
*, name
, const void __user
*, value
,
512 size_t, size
, int, flags
)
514 return path_setxattr(pathname
, name
, value
, size
, flags
, 0);
517 SYSCALL_DEFINE5(fsetxattr
, int, fd
, const char __user
*, name
,
518 const void __user
*,value
, size_t, size
, int, flags
)
520 struct fd f
= fdget(fd
);
526 error
= mnt_want_write_file(f
.file
);
528 error
= setxattr(f
.file
->f_path
.dentry
, name
, value
, size
, flags
);
529 mnt_drop_write_file(f
.file
);
536 * Extended attribute GET operations
539 getxattr(struct dentry
*d
, const char __user
*name
, void __user
*value
,
544 char kname
[XATTR_NAME_MAX
+ 1];
546 error
= strncpy_from_user(kname
, name
, sizeof(kname
));
547 if (error
== 0 || error
== sizeof(kname
))
553 if (size
> XATTR_SIZE_MAX
)
554 size
= XATTR_SIZE_MAX
;
555 kvalue
= kzalloc(size
, GFP_KERNEL
| __GFP_NOWARN
);
557 kvalue
= vmalloc(size
);
563 error
= vfs_getxattr(d
, kname
, kvalue
, size
);
565 if ((strcmp(kname
, XATTR_NAME_POSIX_ACL_ACCESS
) == 0) ||
566 (strcmp(kname
, XATTR_NAME_POSIX_ACL_DEFAULT
) == 0))
567 posix_acl_fix_xattr_to_user(kvalue
, size
);
568 if (size
&& copy_to_user(value
, kvalue
, error
))
570 } else if (error
== -ERANGE
&& size
>= XATTR_SIZE_MAX
) {
571 /* The file system tried to returned a value bigger
572 than XATTR_SIZE_MAX bytes. Not possible. */
581 static ssize_t
path_getxattr(const char __user
*pathname
,
582 const char __user
*name
, void __user
*value
,
583 size_t size
, unsigned int lookup_flags
)
588 error
= user_path_at(AT_FDCWD
, pathname
, lookup_flags
, &path
);
591 error
= getxattr(path
.dentry
, name
, value
, size
);
593 if (retry_estale(error
, lookup_flags
)) {
594 lookup_flags
|= LOOKUP_REVAL
;
600 SYSCALL_DEFINE4(getxattr
, const char __user
*, pathname
,
601 const char __user
*, name
, void __user
*, value
, size_t, size
)
603 return path_getxattr(pathname
, name
, value
, size
, LOOKUP_FOLLOW
);
606 SYSCALL_DEFINE4(lgetxattr
, const char __user
*, pathname
,
607 const char __user
*, name
, void __user
*, value
, size_t, size
)
609 return path_getxattr(pathname
, name
, value
, size
, 0);
612 SYSCALL_DEFINE4(fgetxattr
, int, fd
, const char __user
*, name
,
613 void __user
*, value
, size_t, size
)
615 struct fd f
= fdget(fd
);
616 ssize_t error
= -EBADF
;
621 error
= getxattr(f
.file
->f_path
.dentry
, name
, value
, size
);
627 * Extended attribute LIST operations
630 listxattr(struct dentry
*d
, char __user
*list
, size_t size
)
636 if (size
> XATTR_LIST_MAX
)
637 size
= XATTR_LIST_MAX
;
638 klist
= kmalloc(size
, __GFP_NOWARN
| GFP_KERNEL
);
640 klist
= vmalloc(size
);
646 error
= vfs_listxattr(d
, klist
, size
);
648 if (size
&& copy_to_user(list
, klist
, error
))
650 } else if (error
== -ERANGE
&& size
>= XATTR_LIST_MAX
) {
651 /* The file system tried to returned a list bigger
652 than XATTR_LIST_MAX bytes. Not possible. */
661 static ssize_t
path_listxattr(const char __user
*pathname
, char __user
*list
,
662 size_t size
, unsigned int lookup_flags
)
667 error
= user_path_at(AT_FDCWD
, pathname
, lookup_flags
, &path
);
670 error
= listxattr(path
.dentry
, list
, size
);
672 if (retry_estale(error
, lookup_flags
)) {
673 lookup_flags
|= LOOKUP_REVAL
;
679 SYSCALL_DEFINE3(listxattr
, const char __user
*, pathname
, char __user
*, list
,
682 return path_listxattr(pathname
, list
, size
, LOOKUP_FOLLOW
);
685 SYSCALL_DEFINE3(llistxattr
, const char __user
*, pathname
, char __user
*, list
,
688 return path_listxattr(pathname
, list
, size
, 0);
691 SYSCALL_DEFINE3(flistxattr
, int, fd
, char __user
*, list
, size_t, size
)
693 struct fd f
= fdget(fd
);
694 ssize_t error
= -EBADF
;
699 error
= listxattr(f
.file
->f_path
.dentry
, list
, size
);
705 * Extended attribute REMOVE operations
708 removexattr(struct dentry
*d
, const char __user
*name
)
711 char kname
[XATTR_NAME_MAX
+ 1];
713 error
= strncpy_from_user(kname
, name
, sizeof(kname
));
714 if (error
== 0 || error
== sizeof(kname
))
719 return vfs_removexattr(d
, kname
);
722 static int path_removexattr(const char __user
*pathname
,
723 const char __user
*name
, unsigned int lookup_flags
)
728 error
= user_path_at(AT_FDCWD
, pathname
, lookup_flags
, &path
);
731 error
= mnt_want_write(path
.mnt
);
733 error
= removexattr(path
.dentry
, name
);
734 mnt_drop_write(path
.mnt
);
737 if (retry_estale(error
, lookup_flags
)) {
738 lookup_flags
|= LOOKUP_REVAL
;
744 SYSCALL_DEFINE2(removexattr
, const char __user
*, pathname
,
745 const char __user
*, name
)
747 return path_removexattr(pathname
, name
, LOOKUP_FOLLOW
);
750 SYSCALL_DEFINE2(lremovexattr
, const char __user
*, pathname
,
751 const char __user
*, name
)
753 return path_removexattr(pathname
, name
, 0);
756 SYSCALL_DEFINE2(fremovexattr
, int, fd
, const char __user
*, name
)
758 struct fd f
= fdget(fd
);
764 error
= mnt_want_write_file(f
.file
);
766 error
= removexattr(f
.file
->f_path
.dentry
, name
);
767 mnt_drop_write_file(f
.file
);
774 * Combine the results of the list() operation from every xattr_handler in the
778 generic_listxattr(struct dentry
*dentry
, char *buffer
, size_t buffer_size
)
780 const struct xattr_handler
*handler
, **handlers
= dentry
->d_sb
->s_xattr
;
781 unsigned int size
= 0;
784 for_each_xattr_handler(handlers
, handler
) {
785 if (!handler
->name
||
786 (handler
->list
&& !handler
->list(dentry
)))
788 size
+= strlen(handler
->name
) + 1;
794 for_each_xattr_handler(handlers
, handler
) {
795 if (!handler
->name
||
796 (handler
->list
&& !handler
->list(dentry
)))
798 len
= strlen(handler
->name
);
799 if (len
+ 1 > buffer_size
)
801 memcpy(buf
, handler
->name
, len
+ 1);
803 buffer_size
-= len
+ 1;
809 EXPORT_SYMBOL(generic_listxattr
);
812 * xattr_full_name - Compute full attribute name from suffix
814 * @handler: handler of the xattr_handler operation
815 * @name: name passed to the xattr_handler operation
817 * The get and set xattr handler operations are called with the remainder of
818 * the attribute name after skipping the handler's prefix: for example, "foo"
819 * is passed to the get operation of a handler with prefix "user." to get
820 * attribute "user.foo". The full name is still "there" in the name though.
822 * Note: the list xattr handler operation when called from the vfs is passed a
823 * NULL name; some file systems use this operation internally, with varying
826 const char *xattr_full_name(const struct xattr_handler
*handler
,
829 size_t prefix_len
= strlen(xattr_prefix(handler
));
831 return name
- prefix_len
;
833 EXPORT_SYMBOL(xattr_full_name
);
836 * Allocate new xattr and copy in the value; but leave the name to callers.
838 struct simple_xattr
*simple_xattr_alloc(const void *value
, size_t size
)
840 struct simple_xattr
*new_xattr
;
844 len
= sizeof(*new_xattr
) + size
;
845 if (len
< sizeof(*new_xattr
))
848 new_xattr
= kmalloc(len
, GFP_KERNEL
);
852 new_xattr
->size
= size
;
853 memcpy(new_xattr
->value
, value
, size
);
858 * xattr GET operation for in-memory/pseudo filesystems
860 int simple_xattr_get(struct simple_xattrs
*xattrs
, const char *name
,
861 void *buffer
, size_t size
)
863 struct simple_xattr
*xattr
;
866 spin_lock(&xattrs
->lock
);
867 list_for_each_entry(xattr
, &xattrs
->head
, list
) {
868 if (strcmp(name
, xattr
->name
))
873 if (size
< xattr
->size
)
876 memcpy(buffer
, xattr
->value
, xattr
->size
);
880 spin_unlock(&xattrs
->lock
);
885 * simple_xattr_set - xattr SET operation for in-memory/pseudo filesystems
886 * @xattrs: target simple_xattr list
887 * @name: name of the extended attribute
888 * @value: value of the xattr. If %NULL, will remove the attribute.
889 * @size: size of the new xattr
890 * @flags: %XATTR_{CREATE|REPLACE}
892 * %XATTR_CREATE is set, the xattr shouldn't exist already; otherwise fails
893 * with -EEXIST. If %XATTR_REPLACE is set, the xattr should exist;
894 * otherwise, fails with -ENODATA.
896 * Returns 0 on success, -errno on failure.
898 int simple_xattr_set(struct simple_xattrs
*xattrs
, const char *name
,
899 const void *value
, size_t size
, int flags
)
901 struct simple_xattr
*xattr
;
902 struct simple_xattr
*new_xattr
= NULL
;
905 /* value == NULL means remove */
907 new_xattr
= simple_xattr_alloc(value
, size
);
911 new_xattr
->name
= kstrdup(name
, GFP_KERNEL
);
912 if (!new_xattr
->name
) {
918 spin_lock(&xattrs
->lock
);
919 list_for_each_entry(xattr
, &xattrs
->head
, list
) {
920 if (!strcmp(name
, xattr
->name
)) {
921 if (flags
& XATTR_CREATE
) {
924 } else if (new_xattr
) {
925 list_replace(&xattr
->list
, &new_xattr
->list
);
927 list_del(&xattr
->list
);
932 if (flags
& XATTR_REPLACE
) {
936 list_add(&new_xattr
->list
, &xattrs
->head
);
940 spin_unlock(&xattrs
->lock
);
949 static bool xattr_is_trusted(const char *name
)
951 return !strncmp(name
, XATTR_TRUSTED_PREFIX
, XATTR_TRUSTED_PREFIX_LEN
);
954 static int xattr_list_one(char **buffer
, ssize_t
*remaining_size
,
957 size_t len
= strlen(name
) + 1;
959 if (*remaining_size
< len
)
961 memcpy(*buffer
, name
, len
);
964 *remaining_size
-= len
;
969 * xattr LIST operation for in-memory/pseudo filesystems
971 ssize_t
simple_xattr_list(struct inode
*inode
, struct simple_xattrs
*xattrs
,
972 char *buffer
, size_t size
)
974 bool trusted
= capable(CAP_SYS_ADMIN
);
975 struct simple_xattr
*xattr
;
976 ssize_t remaining_size
= size
;
979 #ifdef CONFIG_FS_POSIX_ACL
981 err
= xattr_list_one(&buffer
, &remaining_size
,
982 XATTR_NAME_POSIX_ACL_ACCESS
);
986 if (inode
->i_default_acl
) {
987 err
= xattr_list_one(&buffer
, &remaining_size
,
988 XATTR_NAME_POSIX_ACL_DEFAULT
);
994 spin_lock(&xattrs
->lock
);
995 list_for_each_entry(xattr
, &xattrs
->head
, list
) {
996 /* skip "trusted." attributes for unprivileged callers */
997 if (!trusted
&& xattr_is_trusted(xattr
->name
))
1000 err
= xattr_list_one(&buffer
, &remaining_size
, xattr
->name
);
1004 spin_unlock(&xattrs
->lock
);
1006 return err
? err
: size
- remaining_size
;
1010 * Adds an extended attribute to the list
1012 void simple_xattr_list_add(struct simple_xattrs
*xattrs
,
1013 struct simple_xattr
*new_xattr
)
1015 spin_lock(&xattrs
->lock
);
1016 list_add(&new_xattr
->list
, &xattrs
->head
);
1017 spin_unlock(&xattrs
->lock
);