![Christoph Hellwig](/assets/img/avatar_default.png)
Add a flags argument to struct xattr_handler and pass it to all xattr handler methods. This allows using the same methods for multiple handlers, e.g. for the ACL methods which perform exactly the same action for the access and default ACLs, just using a different underlying attribute. With a little more groundwork it'll also allow sharing the methods for the regular user/trusted/secure handlers in extN, ocfs2 and jffs2 like it's already done for xfs in this patch. Also change the inode argument to the handlers to a dentry to allow using the handlers mechnism for filesystems that require it later, e.g. cifs. [with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
306 lines
6.1 KiB
C
306 lines
6.1 KiB
C
/*
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* Copyright (C) 2007 Red Hat. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#include <linux/fs.h>
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#include <linux/string.h>
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#include <linux/xattr.h>
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#include <linux/posix_acl_xattr.h>
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#include <linux/posix_acl.h>
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#include <linux/sched.h>
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#include "ctree.h"
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#include "btrfs_inode.h"
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#include "xattr.h"
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#ifdef CONFIG_BTRFS_FS_POSIX_ACL
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static struct posix_acl *btrfs_get_acl(struct inode *inode, int type)
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{
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int size;
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const char *name;
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char *value = NULL;
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struct posix_acl *acl;
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acl = get_cached_acl(inode, type);
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if (acl != ACL_NOT_CACHED)
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return acl;
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switch (type) {
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case ACL_TYPE_ACCESS:
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name = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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name = POSIX_ACL_XATTR_DEFAULT;
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break;
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default:
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BUG();
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}
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size = __btrfs_getxattr(inode, name, "", 0);
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if (size > 0) {
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value = kzalloc(size, GFP_NOFS);
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if (!value)
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return ERR_PTR(-ENOMEM);
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size = __btrfs_getxattr(inode, name, value, size);
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if (size > 0) {
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acl = posix_acl_from_xattr(value, size);
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set_cached_acl(inode, type, acl);
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}
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kfree(value);
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} else if (size == -ENOENT || size == -ENODATA || size == 0) {
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/* FIXME, who returns -ENOENT? I think nobody */
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acl = NULL;
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set_cached_acl(inode, type, acl);
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} else {
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acl = ERR_PTR(-EIO);
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}
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return acl;
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}
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static int btrfs_xattr_acl_get(struct dentry *dentry, const char *name,
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void *value, size_t size, int type)
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{
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struct posix_acl *acl;
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int ret = 0;
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acl = btrfs_get_acl(dentry->d_inode, type);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl == NULL)
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return -ENODATA;
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ret = posix_acl_to_xattr(acl, value, size);
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posix_acl_release(acl);
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return ret;
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}
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/*
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* Needs to be called with fs_mutex held
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*/
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static int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
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{
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int ret, size = 0;
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const char *name;
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char *value = NULL;
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mode_t mode;
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if (acl) {
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ret = posix_acl_valid(acl);
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if (ret < 0)
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return ret;
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ret = 0;
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}
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switch (type) {
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case ACL_TYPE_ACCESS:
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mode = inode->i_mode;
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ret = posix_acl_equiv_mode(acl, &mode);
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if (ret < 0)
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return ret;
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ret = 0;
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inode->i_mode = mode;
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name = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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if (!S_ISDIR(inode->i_mode))
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return acl ? -EINVAL : 0;
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name = POSIX_ACL_XATTR_DEFAULT;
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break;
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default:
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return -EINVAL;
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}
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if (acl) {
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size = posix_acl_xattr_size(acl->a_count);
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value = kmalloc(size, GFP_NOFS);
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if (!value) {
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ret = -ENOMEM;
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goto out;
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}
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ret = posix_acl_to_xattr(acl, value, size);
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if (ret < 0)
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goto out;
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}
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ret = __btrfs_setxattr(inode, name, value, size, 0);
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out:
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kfree(value);
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if (!ret)
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set_cached_acl(inode, type, acl);
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return ret;
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}
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static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name,
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const void *value, size_t size, int flags, int type)
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{
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int ret = 0;
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struct posix_acl *acl = NULL;
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if (value) {
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acl = posix_acl_from_xattr(value, size);
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if (acl == NULL) {
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value = NULL;
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size = 0;
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} else if (IS_ERR(acl)) {
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return PTR_ERR(acl);
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}
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}
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ret = btrfs_set_acl(dentry->d_inode, acl, type);
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posix_acl_release(acl);
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return ret;
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}
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int btrfs_check_acl(struct inode *inode, int mask)
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{
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struct posix_acl *acl;
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int error = -EAGAIN;
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acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl) {
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error = posix_acl_permission(inode, acl, mask);
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posix_acl_release(acl);
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}
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return error;
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}
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/*
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* btrfs_init_acl is already generally called under fs_mutex, so the locking
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* stuff has been fixed to work with that. If the locking stuff changes, we
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* need to re-evaluate the acl locking stuff.
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*/
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int btrfs_init_acl(struct inode *inode, struct inode *dir)
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{
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struct posix_acl *acl = NULL;
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int ret = 0;
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/* this happens with subvols */
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if (!dir)
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return 0;
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if (!S_ISLNK(inode->i_mode)) {
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if (IS_POSIXACL(dir)) {
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acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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}
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if (!acl)
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inode->i_mode &= ~current_umask();
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}
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if (IS_POSIXACL(dir) && acl) {
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struct posix_acl *clone;
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mode_t mode;
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if (S_ISDIR(inode->i_mode)) {
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ret = btrfs_set_acl(inode, acl, ACL_TYPE_DEFAULT);
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if (ret)
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goto failed;
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}
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clone = posix_acl_clone(acl, GFP_NOFS);
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ret = -ENOMEM;
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if (!clone)
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goto failed;
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mode = inode->i_mode;
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ret = posix_acl_create_masq(clone, &mode);
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if (ret >= 0) {
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inode->i_mode = mode;
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if (ret > 0) {
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/* we need an acl */
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ret = btrfs_set_acl(inode, clone,
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ACL_TYPE_ACCESS);
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}
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}
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}
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failed:
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posix_acl_release(acl);
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return ret;
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}
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int btrfs_acl_chmod(struct inode *inode)
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{
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struct posix_acl *acl, *clone;
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int ret = 0;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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if (!IS_POSIXACL(inode))
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return 0;
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acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS);
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if (IS_ERR(acl) || !acl)
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return PTR_ERR(acl);
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clone = posix_acl_clone(acl, GFP_KERNEL);
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posix_acl_release(acl);
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if (!clone)
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return -ENOMEM;
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ret = posix_acl_chmod_masq(clone, inode->i_mode);
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if (!ret)
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ret = btrfs_set_acl(inode, clone, ACL_TYPE_ACCESS);
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posix_acl_release(clone);
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return ret;
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}
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struct xattr_handler btrfs_xattr_acl_default_handler = {
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.prefix = POSIX_ACL_XATTR_DEFAULT,
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.flags = ACL_TYPE_DEFAULT,
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.get = btrfs_xattr_acl_get,
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.set = btrfs_xattr_acl_set,
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};
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struct xattr_handler btrfs_xattr_acl_access_handler = {
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.prefix = POSIX_ACL_XATTR_ACCESS,
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.flags = ACL_TYPE_ACCESS,
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.get = btrfs_xattr_acl_get,
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.set = btrfs_xattr_acl_set,
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};
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#else /* CONFIG_BTRFS_FS_POSIX_ACL */
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int btrfs_acl_chmod(struct inode *inode)
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{
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return 0;
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}
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int btrfs_init_acl(struct inode *inode, struct inode *dir)
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{
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return 0;
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}
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#endif /* CONFIG_BTRFS_FS_POSIX_ACL */
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