[Devel] [PATCH RH7] pfcache: hide trusted.pfcache from listxattr

[Dmitry Monakhov]

Pavel Tikhomirov <ptikhomirov at virtuozzo.com> writes:

> In SyS_listxattr -> listxattr -> ext4_listxattr ->
> ext4_xattr_list_entries we choose list handler for
> each ext4_xattr_entry based on e_name_index, and as
> for trusted.pfcache index is EXT4_XATTR_INDEX_TRUSTED,
> we chouse ext4_xattr_trusted_list which prints xattr
> to the list.
>
> To hide our trusted.pfcache from list change e_name_index
> to new EXT4_XATTR_INDEX_TRUSTED_CSUM and thus use
> ext4_xattr_trusted_csum_list instead which won't put
> xattr to the returned list.
Why we want to hide it?
>
> Test:
>
> TEST_FILE=/vz/root/101/testfile
> TEST_SHA1=`sha1sum $TEST_FILE | awk '{print $1}'`
> setfattr -n trusted.pfcache -v $TEST_SHA1 $TEST_FILE
> setfattr -n trusted.test -v test $TEST_FILE
> getfattr -d -m trusted $TEST_FILE
>
> before patch it was listed:
>
> trusted.pfcache="da39a3ee5e6b4b0d3255bfef95601890afd80709"
> trusted.test="test"
>
> after - not:
>
> trusted.test="test"
>
> https://jira.sw.ru/browse/PSBM-52180
> Signed-off-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>
> ---
>  fs/ext4/pfcache.c | 28 ++++++++++++++--------------
>  fs/ext4/xattr.c   |  1 +
>  fs/ext4/xattr.h   |  1 +
>  3 files changed, 16 insertions(+), 14 deletions(-)
>
> diff --git a/fs/ext4/pfcache.c b/fs/ext4/pfcache.c
> index ff2300b..5fc6d9f 100644
> --- a/fs/ext4/pfcache.c
> +++ b/fs/ext4/pfcache.c
> @@ -441,8 +441,8 @@ int ext4_load_data_csum(struct inode *inode)
>  {
>  	int ret;
>  
> -	ret = ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED,
> -			EXT4_DATA_CSUM_NAME, EXT4_I(inode)->i_data_csum,
> +	ret = ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED_CSUM,
> +			"", EXT4_I(inode)->i_data_csum,
>  			EXT4_DATA_CSUM_SIZE);
>  	if (ret < 0)
>  		return ret;
> @@ -482,8 +482,8 @@ static int ext4_save_data_csum(struct inode *inode, u8 *csum)
>  	if (ret)
>  		return ret;
>  
> -	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED,
> -			EXT4_DATA_CSUM_NAME, EXT4_I(inode)->i_data_csum,
> +	return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED_CSUM,
> +			"", EXT4_I(inode)->i_data_csum,
>  			EXT4_DATA_CSUM_SIZE, 0);
>  }
>  
> @@ -492,8 +492,8 @@ void ext4_load_dir_csum(struct inode *inode)
>  	char value[EXT4_DIR_CSUM_VALUE_LEN];
>  	int ret;
>  
> -	ret = ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED,
> -			     EXT4_DATA_CSUM_NAME, value, sizeof(value));
> +	ret = ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED_CSUM,
> +			     "", value, sizeof(value));
>  	if (ret == EXT4_DIR_CSUM_VALUE_LEN &&
>  	    !strncmp(value, EXT4_DIR_CSUM_VALUE, sizeof(value)))
>  		ext4_set_inode_state(inode, EXT4_STATE_PFCACHE_CSUM);
> @@ -502,8 +502,8 @@ void ext4_load_dir_csum(struct inode *inode)
>  void ext4_save_dir_csum(struct inode *inode)
>  {
>  	ext4_set_inode_state(inode, EXT4_STATE_PFCACHE_CSUM);
> -	ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED,
> -			EXT4_DATA_CSUM_NAME,
> +	ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED_CSUM,
> +			"",
>  			EXT4_DIR_CSUM_VALUE,
>  			EXT4_DIR_CSUM_VALUE_LEN, 0);
>  }
> @@ -516,8 +516,8 @@ void ext4_truncate_data_csum(struct inode *inode, loff_t pos)
>  
>  	if (EXT4_I(inode)->i_data_csum_end < 0) {
>  		WARN_ON(journal_current_handle());
> -		ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED,
> -				EXT4_DATA_CSUM_NAME, NULL, 0, 0);
> +		ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED_CSUM,
> +				"", NULL, 0, 0);
>  		ext4_close_pfcache(inode);
>  	}
>  	spin_lock(&inode->i_lock);
> @@ -658,8 +658,8 @@ static int ext4_xattr_trusted_csum_get(struct dentry *dentry, const char *name,
>  		return -EPERM;
>  
>  	if (S_ISDIR(inode->i_mode))
> -		return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED,
> -				      EXT4_DATA_CSUM_NAME, buffer, size);
> +		return ext4_xattr_get(inode, EXT4_XATTR_INDEX_TRUSTED_CSUM,
> +				      "", buffer, size);
>  
>  	if (!S_ISREG(inode->i_mode))
>  		return -ENODATA;
> @@ -717,8 +717,8 @@ static int ext4_xattr_trusted_csum_set(struct dentry *dentry, const char *name,
>  		else
>  			return -EINVAL;
>  
> -		return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED,
> -				      EXT4_DATA_CSUM_NAME, value, size, flags);
> +		return ext4_xattr_set(inode, EXT4_XATTR_INDEX_TRUSTED_CSUM,
> +				      "", value, size, flags);
>  	}
>  
>  	if (!S_ISREG(inode->i_mode))
> diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
> index 5dabf58..81b5534 100644
> --- a/fs/ext4/xattr.c
> +++ b/fs/ext4/xattr.c
> @@ -102,6 +102,7 @@ static const struct xattr_handler *ext4_xattr_handler_map[] = {
>  #ifdef CONFIG_EXT4_FS_SECURITY
>  	[EXT4_XATTR_INDEX_SECURITY]	     = &ext4_xattr_security_handler,
>  #endif
> +	[EXT4_XATTR_INDEX_TRUSTED_CSUM]	     = &ext4_xattr_trusted_csum_handler,
>  };
>  
>  const struct xattr_handler *ext4_xattr_handlers[] = {
> diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
> index c767dbd..f6af6c9 100644
> --- a/fs/ext4/xattr.h
> +++ b/fs/ext4/xattr.h
> @@ -23,6 +23,7 @@
>  #define EXT4_XATTR_INDEX_SECURITY	        6
>  #define EXT4_XATTR_INDEX_SYSTEM			7
>  #define EXT4_XATTR_INDEX_RICHACL		8
> +#define EXT4_XATTR_INDEX_TRUSTED_CSUM		9
>  
>  struct ext4_xattr_header {
>  	__le32	h_magic;	/* magic number for identification */
> -- 
> 2.5.5
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