diff options
Diffstat (limited to 'kernel/fs/btrfs/acl.c')
| -rw-r--r-- | kernel/fs/btrfs/acl.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/kernel/fs/btrfs/acl.c b/kernel/fs/btrfs/acl.c new file mode 100644 index 000000000..9a0124a95 --- /dev/null +++ b/kernel/fs/btrfs/acl.c @@ -0,0 +1,166 @@ +/* + * 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" + +struct posix_acl *btrfs_get_acl(struct inode *inode, int type) +{ + int size; + const char *name; + char *value = NULL; + struct posix_acl *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(&init_user_ns, value, size); + } else if (size == -ENOENT || size == -ENODATA || size == 0) { + /* FIXME, who returns -ENOENT? I think nobody */ + acl = NULL; + } else { + acl = ERR_PTR(-EIO); + } + kfree(value); + + if (!IS_ERR(acl)) + set_cached_acl(inode, type, acl); + + return acl; +} + +/* + * 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; + + switch (type) { + case ACL_TYPE_ACCESS: + name = POSIX_ACL_XATTR_ACCESS; + if (acl) { + ret = posix_acl_equiv_mode(acl, &inode->i_mode); + if (ret < 0) + return ret; + if (ret == 0) + acl = NULL; + } + 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(&init_user_ns, 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; +} + +int btrfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) +{ + return __btrfs_set_acl(NULL, inode, acl, type); +} + +/* + * 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 *default_acl, *acl; + int ret = 0; + + /* this happens with subvols */ + if (!dir) + return 0; + + ret = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); + if (ret) + return ret; + + if (default_acl) { + ret = __btrfs_set_acl(trans, inode, default_acl, + ACL_TYPE_DEFAULT); + posix_acl_release(default_acl); + } + + if (acl) { + if (!ret) + ret = __btrfs_set_acl(trans, inode, acl, + ACL_TYPE_ACCESS); + posix_acl_release(acl); + } + + if (!default_acl && !acl) + cache_no_acl(inode); + return ret; +} |