| /* |
| * Copyright (C) 2007 Red Hat. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * 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 021110-1307, USA. |
| */ |
| |
| #include <linux/fs.h> |
| #include <linux/string.h> |
| #include <linux/xattr.h> |
| #include <linux/posix_acl_xattr.h> |
| #include <linux/posix_acl.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| |
| #include "ctree.h" |
| #include "btrfs_inode.h" |
| #include "xattr.h" |
| |
| #ifdef CONFIG_BTRFS_FS_POSIX_ACL |
| |
| static struct posix_acl *btrfs_get_acl(struct inode *inode, int type) |
| { |
| int size; |
| const char *name; |
| char *value = NULL; |
| struct posix_acl *acl; |
| |
| acl = get_cached_acl(inode, type); |
| if (acl != ACL_NOT_CACHED) |
| return acl; |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| name = POSIX_ACL_XATTR_ACCESS; |
| break; |
| case ACL_TYPE_DEFAULT: |
| name = POSIX_ACL_XATTR_DEFAULT; |
| break; |
| default: |
| BUG(); |
| } |
| |
| size = __btrfs_getxattr(inode, name, "", 0); |
| if (size > 0) { |
| value = kzalloc(size, GFP_NOFS); |
| if (!value) |
| return ERR_PTR(-ENOMEM); |
| size = __btrfs_getxattr(inode, name, value, size); |
| if (size > 0) { |
| acl = posix_acl_from_xattr(value, size); |
| if (IS_ERR(acl)) |
| return acl; |
| set_cached_acl(inode, type, acl); |
| } |
| kfree(value); |
| } else if (size == -ENOENT || size == -ENODATA || size == 0) { |
| /* FIXME, who returns -ENOENT? I think nobody */ |
| acl = NULL; |
| set_cached_acl(inode, type, acl); |
| } else { |
| acl = ERR_PTR(-EIO); |
| } |
| |
| return acl; |
| } |
| |
| static int btrfs_xattr_acl_get(struct dentry *dentry, const char *name, |
| void *value, size_t size, int type) |
| { |
| struct posix_acl *acl; |
| int ret = 0; |
| |
| acl = btrfs_get_acl(dentry->d_inode, type); |
| |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| if (acl == NULL) |
| return -ENODATA; |
| ret = posix_acl_to_xattr(acl, value, size); |
| posix_acl_release(acl); |
| |
| return ret; |
| } |
| |
| /* |
| * Needs to be called with fs_mutex held |
| */ |
| static int btrfs_set_acl(struct btrfs_trans_handle *trans, |
| struct inode *inode, struct posix_acl *acl, int type) |
| { |
| int ret, size = 0; |
| const char *name; |
| char *value = NULL; |
| mode_t mode; |
| |
| if (acl) { |
| ret = posix_acl_valid(acl); |
| if (ret < 0) |
| return ret; |
| ret = 0; |
| } |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| mode = inode->i_mode; |
| name = POSIX_ACL_XATTR_ACCESS; |
| if (acl) { |
| ret = posix_acl_equiv_mode(acl, &mode); |
| if (ret < 0) |
| return ret; |
| inode->i_mode = mode; |
| } |
| ret = 0; |
| break; |
| case ACL_TYPE_DEFAULT: |
| if (!S_ISDIR(inode->i_mode)) |
| return acl ? -EINVAL : 0; |
| name = POSIX_ACL_XATTR_DEFAULT; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| if (acl) { |
| size = posix_acl_xattr_size(acl->a_count); |
| value = kmalloc(size, GFP_NOFS); |
| if (!value) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret = posix_acl_to_xattr(acl, value, size); |
| if (ret < 0) |
| goto out; |
| } |
| |
| ret = __btrfs_setxattr(trans, inode, name, value, size, 0); |
| out: |
| kfree(value); |
| |
| if (!ret) |
| set_cached_acl(inode, type, acl); |
| |
| return ret; |
| } |
| |
| static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name, |
| const void *value, size_t size, int flags, int type) |
| { |
| int ret; |
| struct posix_acl *acl = NULL; |
| |
| if (!is_owner_or_cap(dentry->d_inode)) |
| return -EPERM; |
| |
| if (!IS_POSIXACL(dentry->d_inode)) |
| return -EOPNOTSUPP; |
| |
| if (value) { |
| acl = posix_acl_from_xattr(value, size); |
| if (acl == NULL) { |
| value = NULL; |
| size = 0; |
| } else if (IS_ERR(acl)) { |
| return PTR_ERR(acl); |
| } |
| } |
| |
| ret = btrfs_set_acl(NULL, dentry->d_inode, acl, type); |
| |
| posix_acl_release(acl); |
| |
| return ret; |
| } |
| |
| int btrfs_check_acl(struct inode *inode, int mask) |
| { |
| struct posix_acl *acl; |
| int error = -EAGAIN; |
| |
| acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); |
| |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| if (acl) { |
| error = posix_acl_permission(inode, acl, mask); |
| posix_acl_release(acl); |
| } |
| |
| return error; |
| } |
| |
| /* |
| * btrfs_init_acl is already generally called under fs_mutex, so the locking |
| * stuff has been fixed to work with that. If the locking stuff changes, we |
| * need to re-evaluate the acl locking stuff. |
| */ |
| int btrfs_init_acl(struct btrfs_trans_handle *trans, |
| struct inode *inode, struct inode *dir) |
| { |
| struct posix_acl *acl = NULL; |
| int ret = 0; |
| |
| /* this happens with subvols */ |
| if (!dir) |
| return 0; |
| |
| if (!S_ISLNK(inode->i_mode)) { |
| if (IS_POSIXACL(dir)) { |
| acl = btrfs_get_acl(dir, ACL_TYPE_DEFAULT); |
| if (IS_ERR(acl)) |
| return PTR_ERR(acl); |
| } |
| |
| if (!acl) |
| inode->i_mode &= ~current_umask(); |
| } |
| |
| if (IS_POSIXACL(dir) && acl) { |
| struct posix_acl *clone; |
| mode_t mode; |
| |
| if (S_ISDIR(inode->i_mode)) { |
| ret = btrfs_set_acl(trans, inode, acl, |
| ACL_TYPE_DEFAULT); |
| if (ret) |
| goto failed; |
| } |
| clone = posix_acl_clone(acl, GFP_NOFS); |
| ret = -ENOMEM; |
| if (!clone) |
| goto failed; |
| |
| mode = inode->i_mode; |
| ret = posix_acl_create_masq(clone, &mode); |
| if (ret >= 0) { |
| inode->i_mode = mode; |
| if (ret > 0) { |
| /* we need an acl */ |
| ret = btrfs_set_acl(trans, inode, clone, |
| ACL_TYPE_ACCESS); |
| } |
| } |
| posix_acl_release(clone); |
| } |
| failed: |
| posix_acl_release(acl); |
| |
| return ret; |
| } |
| |
| int btrfs_acl_chmod(struct inode *inode) |
| { |
| struct posix_acl *acl, *clone; |
| int ret = 0; |
| |
| if (S_ISLNK(inode->i_mode)) |
| return -EOPNOTSUPP; |
| |
| if (!IS_POSIXACL(inode)) |
| return 0; |
| |
| acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); |
| if (IS_ERR(acl) || !acl) |
| return PTR_ERR(acl); |
| |
| clone = posix_acl_clone(acl, GFP_KERNEL); |
| posix_acl_release(acl); |
| if (!clone) |
| return -ENOMEM; |
| |
| ret = posix_acl_chmod_masq(clone, inode->i_mode); |
| if (!ret) |
| ret = btrfs_set_acl(NULL, inode, clone, ACL_TYPE_ACCESS); |
| |
| posix_acl_release(clone); |
| |
| return ret; |
| } |
| |
| struct xattr_handler btrfs_xattr_acl_default_handler = { |
| .prefix = POSIX_ACL_XATTR_DEFAULT, |
| .flags = ACL_TYPE_DEFAULT, |
| .get = btrfs_xattr_acl_get, |
| .set = btrfs_xattr_acl_set, |
| }; |
| |
| struct xattr_handler btrfs_xattr_acl_access_handler = { |
| .prefix = POSIX_ACL_XATTR_ACCESS, |
| .flags = ACL_TYPE_ACCESS, |
| .get = btrfs_xattr_acl_get, |
| .set = btrfs_xattr_acl_set, |
| }; |
| |
| #else /* CONFIG_BTRFS_FS_POSIX_ACL */ |
| |
| int btrfs_acl_chmod(struct inode *inode) |
| { |
| return 0; |
| } |
| |
| int btrfs_init_acl(struct btrfs_trans_handle *trans, |
| struct inode *inode, struct inode *dir) |
| { |
| return 0; |
| } |
| |
| #endif /* CONFIG_BTRFS_FS_POSIX_ACL */ |