/*
* linux/fs/reiserfs/xattr.c
*
* Copyright (c) 2002 by Jeff Mahoney, <jeffm@suse.com>
*
*/
/*
* In order to implement EA/ACLs in a clean, backwards compatible manner,
* they are implemented as files in a "private" directory.
* Each EA is in it's own file, with the directory layout like so (/ is assumed
* to be relative to fs root). Inside the /.reiserfs_priv/xattrs directory,
* directories named using the capital-hex form of the objectid and
* generation number are used. Inside each directory are individual files
* named with the name of the extended attribute.
*
* So, for objectid 12648430, we could have:
* /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_access
* /.reiserfs_priv/xattrs/C0FFEE.0/system.posix_acl_default
* /.reiserfs_priv/xattrs/C0FFEE.0/user.Content-Type
* .. or similar.
*
* The file contents are the text of the EA. The size is known based on the
* stat data describing the file.
*
* In the case of system.posix_acl_access and system.posix_acl_default, since
* these are special cases for filesystem ACLs, they are interpreted by the
* kernel, in addition, they are negatively and positively cached and attached
* to the inode so that unnecessary lookups are avoided.
*/
#include <linux/reiserfs_fs.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/pagemap.h>
#include <linux/xattr.h>
#include <linux/reiserfs_xattr.h>
#include <linux/reiserfs_acl.h>
#include <asm/uaccess.h>
#include <asm/checksum.h>
#include <linux/smp_lock.h>
#include <linux/stat.h>
#include <asm/semaphore.h>
#define FL_READONLY 128
#define FL_DIR_SEM_HELD 256
#define PRIVROOT_NAME ".reiserfs_priv"
#define XAROOT_NAME "xattrs"
static struct reiserfs_xattr_handler *find_xattr_handler_prefix(const char
*prefix);
static struct dentry *create_xa_root(struct super_block *sb)
{
struct dentry *privroot = dget(REISERFS_SB(sb)->priv_root);
struct dentry *xaroot;
/* This needs to be created at mount-time */
if (!privroot)
return ERR_PTR(-EOPNOTSUPP);
xaroot = lookup_one_len(XAROOT_NAME, privroot, strlen(XAROOT_NAME));
if (IS_ERR(xaroot)) {
