Hi, Dongsheng
On 9/11/2015 1:01 PM, Dongsheng Yang wrote:
> On 09/11/2015 05:09 PM, Sheng Yong wrote:
>> This patch introduce a new file `acl.c', which implements:
>> * initializing ACL for new file according to the directory's default ACL,
>> * getting ACL which finds the ACL releated xattr and converts it to ACL,
>> * setting ACL function which converts ACL to xattr and creates/changes/
>> removes the xattr.
>>
>> On flash ACL format is based on POSIX ACL structures, and POSIX generic
>> functions, posix_acl_[to|from]_xattr, are called to do the ACL conversion
>> between in-memory and on-flash ACL.
>>
>> The ACL xattr handler is not implemented, because UBIFS does not use it.
>
> Why not, I think we can use it.
First of all, thanks for your review :)
It seems xattr handler will be removed because of dead code of security xattr.
And if we do so, I think it's better to do that for all xattr, but not just
security and ACL, and generic_[set|get]xattr should be set in inode_operations
instead of ubifs_[get|set]xattr.
thanks,
Sheng
>
> Yang
>>
>> Signed-off-by: Sheng Yong <shengyong1@xxxxxxxxxx>
>> ---
>> fs/ubifs/acl.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> fs/ubifs/ubifs.h | 14 ++++++
>> 2 files changed, 155 insertions(+)
>> create mode 100644 fs/ubifs/acl.c
>>
>> diff --git a/fs/ubifs/acl.c b/fs/ubifs/acl.c
>> new file mode 100644
>> index 0000000..bf37875
>> --- /dev/null
>> +++ b/fs/ubifs/acl.c
>> @@ -0,0 +1,141 @@
>> +/*
>> + * This file is part of UBIFS.
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms of the GNU General Public License version 2 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.
>> + *
>> + */
>> +
>> +#include <linux/fs.h>
>> +#include <linux/xattr.h>
>> +#include <linux/posix_acl_xattr.h>
>> +
>> +#include "ubifs.h"
>> +
>> +struct posix_acl *ubifs_get_acl(struct inode *inode, int type)
>> +{
>> + struct posix_acl *acl;
>> + char *name, *value = NULL;
>> + int size = 0;
>> +
>> + switch (type) {
>> + case ACL_TYPE_ACCESS:
>> + name = XATTR_NAME_POSIX_ACL_ACCESS;
>> + break;
>> + case ACL_TYPE_DEFAULT:
>> + name = XATTR_NAME_POSIX_ACL_DEFAULT;
>> + break;
>> + default:
>> + BUG();
>> + }
>> +
>> + size = ubifs_do_getxattr(inode, name, NULL, 0);
>> + if (size > 0) {
>> + value = kmalloc(size, GFP_KERNEL);
>> + if (!value)
>> + return ERR_PTR(-ENOMEM);
>> + size = ubifs_do_getxattr(inode, name, value, size);
>> + }
>> + if (size > 0)
>> + acl = posix_acl_from_xattr(&init_user_ns, value, size);
>> + else if (size == -ENODATA)
>> + acl = NULL;
>> + else
>> + acl = ERR_PTR(size);
>> +
>> + kfree(value);
>> + if (!IS_ERR(acl))
>> + set_cached_acl(inode, type, acl);
>> +
>> + return acl;
>> +}
>> +
>> +int ubifs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
>> +{
>> + char *name;
>> + void *value = NULL;
>> + size_t size = 0;
>> + int flag = 0, err;
>> +
>> + switch (type) {
>> + case ACL_TYPE_ACCESS:
>> + name = XATTR_NAME_POSIX_ACL_ACCESS;
>> + if (acl) {
>> + err = posix_acl_equiv_mode(acl, &inode->i_mode);
>> + if (err < 0)
>> + return err;
>> + if (err == 0)
>> + acl = NULL;
>> + }
>> + break;
>> +
>> + case ACL_TYPE_DEFAULT:
>> + name = XATTR_NAME_POSIX_ACL_DEFAULT;
>> + if (!S_ISDIR(inode->i_mode))
>> + return acl ? -EACCES : 0;
>> + break;
>> +
>> + default:
>> + BUG();
>> + }
>> +
>> + if (acl) {
>> + size = posix_acl_xattr_size(acl->a_count);
>> + value = kmalloc(size, GFP_NOFS);
>> + if (!value)
>> + return -ENOMEM;
>> +
>> + err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
>> + if (err < 0) {
>> + kfree(value);
>> + return err;
>> + }
>> + }
>> +
>> + if (size == 0)
>> + flag = XATTR_REPLACE;
>> + err = ubifs_do_setxattr(inode, name, value, size, flag);
>> +
>> + kfree(value);
>> + if (!err)
>> + set_cached_acl(inode, type, acl);
>> +
>> + return err;
>> +}
>> +
>> +/*
>> + * Initialize the ACLs of a new inode.
>> + */
>> +int ubifs_init_acl(struct inode *dir, struct inode *inode)
>> +{
>> + struct posix_acl *default_acl, *acl;
>> + int err;
>> +
>> + err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
>> + if (err)
>> + return err;
>> +
>> + if (default_acl) {
>> + mutex_lock(&inode->i_mutex);
>> + err = ubifs_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
>> + mutex_unlock(&inode->i_mutex);
>> + posix_acl_release(default_acl);
>> + }
>> +
>> + if (acl) {
>> + if (!err) {
>> + mutex_lock(&inode->i_mutex);
>> + err = ubifs_set_acl(inode, acl, ACL_TYPE_ACCESS);
>> + mutex_unlock(&inode->i_mutex);
>> + }
>> + posix_acl_release(acl);
>> + }
>> +
>> + return err;
>> +}
>> diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
>> index 62aa1a5..b9ddc8d 100644
>> --- a/fs/ubifs/ubifs.h
>> +++ b/fs/ubifs/ubifs.h
>> @@ -1767,6 +1767,20 @@ int ubifs_removexattr(struct dentry *dentry, const char *name);
>> int ubifs_init_security(struct inode *dentry, struct inode *inode,
>> const struct qstr *qstr);
>>
>> +/* acl.c */
>> +#ifdef CONFIG_UBIFS_FS_POSIX_ACL
>> +int ubifs_init_acl(struct inode *dir, struct inode *inode);
>> +int ubifs_set_acl(struct inode *inode, struct posix_acl *acl, int type);
>> +struct posix_acl *ubifs_get_acl(struct inode *inode, int type);
>> +#else
>> +static inline int ubifs_init_acl(struct inode *inode, struct inode *dir)
>> +{
>> + return 0;
>> +}
>> +#define ubifs_get_acl NULL
>> +#define ubifs_set_acl NULL
>> +#endif
>> +
>> /* super.c */
>> struct inode *ubifs_iget(struct super_block *sb, unsigned long inum);
>>
>>
>
>
> .
>
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