/*
* Copyright (C) International Business Machines Corp., 2000-2004
* Copyright (C) Christoph Hellwig, 2002
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will 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 to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/xattr.h>
#include <linux/posix_acl_xattr.h>
#include <linux/quotaops.h>
#include <linux/security.h>
#include "jfs_incore.h"
#include "jfs_superblock.h"
#include "jfs_dmap.h"
#include "jfs_debug.h"
#include "jfs_dinode.h"
#include "jfs_extent.h"
#include "jfs_metapage.h"
#include "jfs_xattr.h"
#include "jfs_acl.h"
/*
* jfs_xattr.c: extended attribute service
*
* Overall design --
*
* Format:
*
* Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit
* value) and a variable (0 or more) number of extended attribute
* entries. Each extended attribute entry (jfs_ea) is a <name,value> double
* where <name> is constructed from a null-terminated ascii string
* (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data
* (1 ... 65535 bytes). The in-memory format is
*
* 0 1 2 4 4 + namelen + 1
* +-------+--------+--------+----------------+-------------------+
* | Flags | Name | Value | Name String \0 | Data . . . . |
* | | Length | Length | | |
* +-------+--------+--------+----------------+-------------------+
*
* A jfs_ea_list then is structured as
*
* 0 4 4 + EA_SIZE(ea1)
* +------------+-------------------+--------------------+-----
* | Overall EA | First FEA Element | Second FEA Element | .....
* | List Size | | |
* +------------+-------------------+--------------------+-----
*
* On-disk:
*
* FEALISTs are stored on disk using blocks allocated by dbAlloc() and
* written directly. An EA list may be in-lined in the inode if there is
* sufficient room available.
*/
struct ea_buffer {
int flag; /* Indicates what storage xattr points to */
int max_size; /* largest xattr that fits in current buffer */
dxd_t new_ea; /* dxd to replace ea when modifying xattr */
struct metapage *mp; /* metapage containing ea list */
struct jfs_ea_list *xattr; /* buffer containing ea list */
};
/*
* ea_buffer.flag values
*/
#define EA_INLINE 0x0001
#define EA_EXTENT 0x0002
#define EA_NEW 0x0004
#define EA_MALLOC 0x0008
/*
* These three routines are used to recognize on-disk extended attributes
* that are in a recognized namespace. If the attribute is not recognized,
* "os2." is prepended to the name
*/
static inline int is_os2_xattr(struct jfs_ea *ea)
{
/*
* Check for "system."
*/
if ((ea->namelen >= XATTR_SYSTEM_PREFIX_LEN) &&
!strncmp(ea->name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
return false;
/*
* Check for "user."
*/
if ((ea->namelen >= XATTR_USER_PREFIX_LEN) &&
!strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
return false;
/*
* Check for "security."
*/
if ((ea->namelen >= XATTR_SECURITY_PREFIX_LEN) &&
!strncmp(ea->name, XATTR_SECURITY_PREFIX,
XATTR_SECURITY_PREFIX_LEN))
return false;
/*
* Check for "trusted."
*/
if ((ea->namelen >= XATTR_TRUSTED_PREFIX_LEN) &&
!strncmp(ea->name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
return false;
/*
* Add any other valid namespace prefixes here
*/
/*
* We assume it's OS/2's flat namespace
*/
return true;
}
static inline int name_size(struct jfs_ea *ea)
{
if (is_os2_xattr(ea))
return ea->namelen + XATTR_OS2_PREFIX_LEN;
else
return ea->namelen;
}
static inline int copy_name(char *buffer, struct jfs_ea *ea)
{
int len = ea->namelen;
if (is_os2_xattr(ea)) {
memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN);
buffer += XATTR_OS2_PREFIX_LEN;
len += XATTR_OS2_PREFIX_LEN;
}
memcpy(buffer, ea->name, ea->namelen);
buffer[ea->namelen] = 0;
return len;
}
/* Forward references */
static void ea_release(struct inode *inode, struct ea_buffer *ea_buf);
/*
* NAME: ea_write_inline
*
* FUNCTION: Attempt to write an EA inline if area is available
*
* PRE CONDITIONS:
* Already verified that the specified EA is small enough to fit inline
*
* PARAMETERS:
* ip - Inode pointer
* ealist - EA list pointer
* size - size of ealist in bytes
* ea - dxd_t structure to be filled in with necessary EA information
* if we successfully copy the EA inline
*
* NOTES:
* Checks if the inode's inline area is available. If so