NFSv4 ACL特性
本文介绍NFSv4 ACL权限顺序、权限继承、排序、合并、迁移等特性。
权限顺序
权限生效的顺序,按照显示的ACE顺序evaluate。
ACE类型支持Allow和Deny,Deny可以被设置在任何位置。假设ACL有两个ACE(group:adminis:rwxc和group:adminis:r---),两个ACE的先后顺序会直接决定adminis2是否具有读权限。您在设置ACL时,需要非常注意ACE的位置。
假设在目录dir4中,用户adminis2的权限如下所示,则表示用户adminis2对目录dir4具有所有权限。
#NFSv4 ACL
#owner:root
#group:root
group:adminis2:rwxc:allow
(X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (X)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED
group:adminis2:r---:deny
(X)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
special:owner@:---c:allow
(-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (-)DELETE_CHILD (X)CHOWN (-)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED
special:group@:----:allow
(-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
special:everyone@:----:allow
(-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
假设在目录dir4中,用户adminis2的权限如下所示,则表示用户adminis2无读权限。
#NFSv4 ACL
#owner:root
#group:root
group:adminis2:r---:deny
(X)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
group:adminis2:rwxc:allow
(X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (X)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED
special:owner@:---c:allow
(-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (-)DELETE_CHILD (X)CHOWN (-)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED
special:group@:----:allow
(-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
special:everyone@:----:allow
(-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED
(-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
ACL排序和合并
当为用户新增ACE后,新的ACE并不会与旧的ACE合并。
例如,用户1001(属于群组players)在文件file中具备如下ACL,为用户player增加W权限的ACE后,新的ACE不会与旧的ACE合并。
旧ACE权限
#NFSv4 ACL #owner:root #group:root special:everyone@:----:allow:FileInherit:DirInherit (-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED special:group@:----:allow:FileInherit:DirInherit (-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED special:owner@:----:allow:FileInherit:DirInherit (-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED group:adminis:rwxc:allow:FileInherit:DirInherit (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (X)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED group:players:r-x-:allow:FileInherit:DirInherit (X)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
新ACE权限
#NFSv4 ACL #owner:root #group:root group:players:rwx-:allow:Inherited (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED special:everyone@:----:allow:FileInherit:DirInherit (-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED special:group@:----:allow:FileInherit:DirInherit (-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED special:owner@:----:allow:FileInherit:DirInherit (-)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED group:adminis:rwxc:allow:FileInherit:DirInherit (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (X)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED group:players:r-x-:allow:FileInherit:DirInherit (X)READ/LIST (-)WRITE/CREATE (-)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
验证新增的权限生效。
执行命令
sudo su player -c 'echo 456 >> file'
sudo su player -c 'cat file'
返回示例
123 456
权限继承
假设当前目录dir5的权限是owner可写,group可读,everyone不能访问。
给用户player增加读写权限并且可继承。
为用户player配置读写权限,并将规则保存至文本(例如,acl2.txt)中。
#NFSv4 ACL #owner:root #group:root user:player:rwx-:allow:DirInherit (X)READ/LIST (X)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED user:player:rwx-:allow:FileInherit (X)READ/LIST (X)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
将acl2的规则应用到目录dir5上。
mmputacl -i ~/acl2.txt dir5
在目录dir5下创建的文件或目录就自动带有继承的ACE。
进入目录dir5。
cd dir5
创建文件file。
touch file
确认文件file自动继承目录dir5的ACE权限。
执行命令
mmgetacl file
返回示例
#NFSv4 ACL #owner:root #group:root user:player:rwx-:allow:Inherited (X)READ/LIST (X)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
创建目录subdir。
mkdir subdir
确认子目录subdir自动继承目录dir5的ACE权限。
执行命令
mmgetacl subdir
返回示例
#NFSv4 ACL #owner:root #group:root user:player:rwx-:allow:DirInherit:Inherited (X)READ/LIST (X)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED user:player:rwx-:allow:FileInherit:InheritOnly:Inherited (X)READ/LIST (X)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
继续在子目录subdir下创建的文件或目录就自动带有继承的ACE。
创建目录subdir/subdir2。
mkdir subdir/subdir2
确认目录subdir/subdir2自动继承子目录subdir的ACE。
执行命令
mmgetacl subdir/subdir2
返回示例
#NFSv4 ACL #owner:root #group:root user:player:rwx-:allow:DirInherit:Inherited (X)READ/LIST (X)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED user:player:rwx-:allow:FileInherit:InheritOnly:Inherited (X)READ/LIST (X)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
创建文件subdir/file2。
touch subdir/file2
确认文件subdir/file2自动继承子目录subdir的ACE。
执行命令
mmgetacl subdir/file2
返回示例
#NFSv4 ACL #owner:root #group:root user:player:rwx-:allow:Inherited (X)READ/LIST (X)WRITE/CREATE (-)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
InheritOnly
在当前目录不参加权限校验,但ACE会继承。
DirInherit和FileInherit要分成两个ACE配置,否则会报错Combining FileInherit and DirInherit makes the mask ambiguous。
inherit only
时,由于ACE本身不做权限检查,父目录上要配置rx权限,否则player无法进入子目录。
输出
不支持通过extended attributes输出NFSv4 ACL。
迁移
支持cp等工具迁移NFSv4 ACL。
阿里云CPFS支持使用Redhat NFSv4 ACL迁移工具说明中提到的cp、tar、rsync工具迁移NFSv4 ACL。
下面例子中cp --preserve=xattr file2 file5
拷贝file2到file5时拷贝了ACL。
rsync工具可能由于版本低于3.1.2而不能迁移NFSv4 ACL。
将file2的ACL迁移至file5。
cp --preserve=xattr newsub/file2 newsub/file5
查看file2的ACL。
执行命令
mmgetacl newsub/file2
返回示例
#NFSv4 ACL #owner:player #group:players user:player:rwx-:allow:Inherited (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (X)WRITE_ATTR (-)WRITE_NAMED
查看file5的ACL。
执行命令
mmgetacl newsub/file5
返回示例
#NFSv4 ACL #owner:root #group:root user:player:rwx-:allow:Inherited (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (-)SYNCHRONIZE (-)READ_ACL (-)READ_ATTR (-)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (X)WRITE_ATTR (-)WRITE_NAMED
NFSv4 ACL与mode的互操作
支持NFSv4 ACL和mode之间的互操作,修改ACL可能引起mode的改变,反之亦然。
例如,文件file当前mode为0666。
文件file的mode权限
-rw-rw-rw- 1 root root 0 Jun 1 14:45 file
文件file的ACE权限
#NFSv4 ACL #owner:root #group:root special:owner@:rw-c:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (X)CHOWN (-)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED special:group@:rw--:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED special:everyone@:rw--:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
通过设置mode给owner增加执行权限,相应ACE也会增加执行权限。
通过设置mode给owner增加执行权限。
chmod u+x file
查看文件file的mode权限。
执行命令
ls -l file
返回示例
-rwxrw-rw- 1 root root 0 Jun 1 14:45 file
确认ACE中owner已增加执行权限。
执行命令
mmgetacl file
返回示例
#NFSv4 ACL #owner:root #group:root special:owner@:rwxc:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (X)CHOWN (X)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED special:group@:rw--:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED special:everyone@:rw--:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
通过设置ACE给group增加执行权限,相应mode也会增加执行权限。
编辑file的ACL属性给group增加执行权限。
mmeditacl file
在返回的信息后,输入
yes
,确认应用修改的权限。查看在文件file中group拥有的ACE权限。
执行命令
mmgetacl file
返回示例
#NFSv4 ACL #owner:root #group:root special:owner@:rwxc:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (X)CHOWN (X)EXEC/SEARCH (X)WRITE_ACL (X)WRITE_ATTR (X)WRITE_NAMED special:group@:rwx-:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (X)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED special:everyone@:rw--:allow (X)READ/LIST (X)WRITE/CREATE (X)APPEND/MKDIR (X)SYNCHRONIZE (X)READ_ACL (X)READ_ATTR (X)READ_NAMED (-)DELETE (-)DELETE_CHILD (-)CHOWN (-)EXEC/SEARCH (-)WRITE_ACL (-)WRITE_ATTR (-)WRITE_NAMED
确认在mode中group已增加执行权限。
执行命令
ls -l file
返回示例
-rwxrwxrw- 1 root root 0 Jun 1 14:45 file
NFSv4 ACL与POSIX ACL互操作
不支持与POSIX ACL互操作。