linux/fs/xfs/linux-2.6/xfs_xattr.c
Christoph Hellwig ef14f0c157 xfs: use generic Posix ACL code
This patch rips out the XFS ACL handling code and uses the generic
fs/posix_acl.c code instead.  The ondisk format is of course left
unchanged.

This also introduces the same ACL caching all other Linux filesystems do
by adding pointers to the acl and default acl in struct xfs_inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
2009-06-10 17:07:47 +02:00

272 lines
6.4 KiB
C

/*
* Copyright (C) 2008 Christoph Hellwig.
* Portions Copyright (C) 2000-2008 Silicon Graphics, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_acl.h"
#include "xfs_vnodeops.h"
#include <linux/posix_acl_xattr.h>
#include <linux/xattr.h>
static int
__xfs_xattr_get(struct inode *inode, const char *name,
void *value, size_t size, int xflags)
{
struct xfs_inode *ip = XFS_I(inode);
int error, asize = size;
if (strcmp(name, "") == 0)
return -EINVAL;
/* Convert Linux syscall to XFS internal ATTR flags */
if (!size) {
xflags |= ATTR_KERNOVAL;
value = NULL;
}
error = -xfs_attr_get(ip, name, value, &asize, xflags);
if (error)
return error;
return asize;
}
static int
__xfs_xattr_set(struct inode *inode, const char *name, const void *value,
size_t size, int flags, int xflags)
{
struct xfs_inode *ip = XFS_I(inode);
if (strcmp(name, "") == 0)
return -EINVAL;
/* Convert Linux syscall to XFS internal ATTR flags */
if (flags & XATTR_CREATE)
xflags |= ATTR_CREATE;
if (flags & XATTR_REPLACE)
xflags |= ATTR_REPLACE;
if (!value)
return -xfs_attr_remove(ip, name, xflags);
return -xfs_attr_set(ip, name, (void *)value, size, xflags);
}
static int
xfs_xattr_user_get(struct inode *inode, const char *name,
void *value, size_t size)
{
return __xfs_xattr_get(inode, name, value, size, 0);
}
static int
xfs_xattr_user_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
return __xfs_xattr_set(inode, name, value, size, flags, 0);
}
static struct xattr_handler xfs_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.get = xfs_xattr_user_get,
.set = xfs_xattr_user_set,
};
static int
xfs_xattr_trusted_get(struct inode *inode, const char *name,
void *value, size_t size)
{
return __xfs_xattr_get(inode, name, value, size, ATTR_ROOT);
}
static int
xfs_xattr_trusted_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
return __xfs_xattr_set(inode, name, value, size, flags, ATTR_ROOT);
}
static struct xattr_handler xfs_xattr_trusted_handler = {
.prefix = XATTR_TRUSTED_PREFIX,
.get = xfs_xattr_trusted_get,
.set = xfs_xattr_trusted_set,
};
static int
xfs_xattr_secure_get(struct inode *inode, const char *name,
void *value, size_t size)
{
return __xfs_xattr_get(inode, name, value, size, ATTR_SECURE);
}
static int
xfs_xattr_secure_set(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
return __xfs_xattr_set(inode, name, value, size, flags, ATTR_SECURE);
}
static struct xattr_handler xfs_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.get = xfs_xattr_secure_get,
.set = xfs_xattr_secure_set,
};
struct xattr_handler *xfs_xattr_handlers[] = {
&xfs_xattr_user_handler,
&xfs_xattr_trusted_handler,
&xfs_xattr_security_handler,
#ifdef CONFIG_XFS_POSIX_ACL
&xfs_xattr_system_handler,
#endif
NULL
};
static unsigned int xfs_xattr_prefix_len(int flags)
{
if (flags & XFS_ATTR_SECURE)
return sizeof("security");
else if (flags & XFS_ATTR_ROOT)
return sizeof("trusted");
else
return sizeof("user");
}
static const char *xfs_xattr_prefix(int flags)
{
if (flags & XFS_ATTR_SECURE)
return xfs_xattr_security_handler.prefix;
else if (flags & XFS_ATTR_ROOT)
return xfs_xattr_trusted_handler.prefix;
else
return xfs_xattr_user_handler.prefix;
}
static int
xfs_xattr_put_listent(struct xfs_attr_list_context *context, int flags,
char *name, int namelen, int valuelen, char *value)
{
unsigned int prefix_len = xfs_xattr_prefix_len(flags);
char *offset;
int arraytop;
ASSERT(context->count >= 0);
/*
* Only show root namespace entries if we are actually allowed to
* see them.
*/
if ((flags & XFS_ATTR_ROOT) && !capable(CAP_SYS_ADMIN))
return 0;
arraytop = context->count + prefix_len + namelen + 1;
if (arraytop > context->firstu) {
context->count = -1; /* insufficient space */
return 1;
}
offset = (char *)context->alist + context->count;
strncpy(offset, xfs_xattr_prefix(flags), prefix_len);
offset += prefix_len;
strncpy(offset, name, namelen); /* real name */
offset += namelen;
*offset = '\0';
context->count += prefix_len + namelen + 1;
return 0;
}
static int
xfs_xattr_put_listent_sizes(struct xfs_attr_list_context *context, int flags,
char *name, int namelen, int valuelen, char *value)
{
context->count += xfs_xattr_prefix_len(flags) + namelen + 1;
return 0;
}
static int
list_one_attr(const char *name, const size_t len, void *data,
size_t size, ssize_t *result)
{
char *p = data + *result;
*result += len;
if (!size)
return 0;
if (*result > size)
return -ERANGE;
strcpy(p, name);
return 0;
}
ssize_t
xfs_vn_listxattr(struct dentry *dentry, char *data, size_t size)
{
struct xfs_attr_list_context context;
struct attrlist_cursor_kern cursor = { 0 };
struct inode *inode = dentry->d_inode;
int error;
/*
* First read the regular on-disk attributes.
*/
memset(&context, 0, sizeof(context));
context.dp = XFS_I(inode);
context.cursor = &cursor;
context.resynch = 1;
context.alist = data;
context.bufsize = size;
context.firstu = context.bufsize;
if (size)
context.put_listent = xfs_xattr_put_listent;
else
context.put_listent = xfs_xattr_put_listent_sizes;
xfs_attr_list_int(&context);
if (context.count < 0)
return -ERANGE;
/*
* Then add the two synthetic ACL attributes.
*/
if (posix_acl_access_exists(inode)) {
error = list_one_attr(POSIX_ACL_XATTR_ACCESS,
strlen(POSIX_ACL_XATTR_ACCESS) + 1,
data, size, &context.count);
if (error)
return error;
}
if (posix_acl_default_exists(inode)) {
error = list_one_attr(POSIX_ACL_XATTR_DEFAULT,
strlen(POSIX_ACL_XATTR_DEFAULT) + 1,
data, size, &context.count);
if (error)
return error;
}
return context.count;
}