linux-kernel - Re: [PATCH 4/4] statx: AFS: Return enhanced file attributes [ver #3]

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Message-Id: <347478EC-7A98-40C0-97EB-2677B6BE1654@dilger.ca>
Date:   Wed, 23 Nov 2016 19:06:30 -0700
From:   Andreas Dilger <adilger@...ger.ca>
To:     David Howells <dhowells@...hat.com>
Cc:     linux-fsdevel@...r.kernel.org, linux-api@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/4] statx: AFS: Return enhanced file attributes [ver #3]

On Nov 22, 2016, at 5:56 PM, David Howells <dhowells@...hat.com> wrote:
> 
> Return enhanced file attributes from the AFS filesystem.  This includes the
> following:
> 
> (1) STATX_ATTR_AUTOMOUNT will be set on automount directories by virtue of
>     S_AUTOMOUNT being set on the inode.  These are referrals to other
>     volumes or other cells.
> 
> STATX_ATIME, STATX_CTIME and STATX_BLOCKS are cleared as AFS does not
> support them.
> 
> Example output:
> 
> 	[root@...romeda ~]# ./samples/statx/test-statx /afs
> 	statx(/afs) = 0
> 	results=7ef

This decodes to everything except STATX_GID being set:
STATX_TYPE	0x00000001U
STATX_MODE	0x00000002U
STATX_NLINK	0x00000004U
STATX_UID	0x00000008U
!STATX_GID	0x00000010U
STATX_ATIME	0x00000020U
STATX_MTIME	0x00000040U
STATX_CTIME	0x00000080U
STATX_INO	0x00000100U
STATX_SIZE	0x00000200U
STATX_BLOCKS	0x00000400U

> 	Size: 2048      Blocks: 0      IO Block: 4096  directory
> 	Device: 00:25           Inode: 1           Links: 2
> 	Access: (0777/drwxrwxrwx)  Uid:     0   Gid:     0
> 	Access: 2006-05-07 00:21:15.000000000+0100
> 	Modify: 2006-05-07 00:21:15.000000000+0100
> 	Change: 2006-05-07 00:21:15.000000000+0100
> 	IO-blocksize: blksize=4096


This is printing Access and Change times, but you write above that
STATX_ATIME, STATX_CTIME, and STATX_BLOCKS are unset for AFS, so they
shouldn't be printed?  Since "results" appear to indicate those flags
are set, and looking at the dump_statx() code appears that they are
checked, it seems this patch isn't doing what you want to clear flags?

Also, it seems that "Gid:  0" is printed even though it is not set in stx_mask?  Possibly this example is old?

Cheers, Andreas

> Signed-off-by: David Howells <dhowells@...hat.com>
> ---
> 
> fs/afs/inode.c |   11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/afs/inode.c b/fs/afs/inode.c
> index 86cc7264c21c..99662045b6fb 100644
> --- a/fs/afs/inode.c
> +++ b/fs/afs/inode.c
> @@ -72,9 +72,9 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
> 	inode->i_uid		= vnode->status.owner;
> 	inode->i_gid		= GLOBAL_ROOT_GID;
> 	inode->i_size		= vnode->status.size;
> -	inode->i_ctime.tv_sec	= vnode->status.mtime_server;
> -	inode->i_ctime.tv_nsec	= 0;
> -	inode->i_atime		= inode->i_mtime = inode->i_ctime;
> +	inode->i_mtime.tv_sec	= vnode->status.mtime_server;
> +	inode->i_mtime.tv_nsec	= 0;
> +	inode->i_atime		= inode->i_ctime = inode->i_mtime;
> 	inode->i_blocks		= 0;
> 	inode->i_generation	= vnode->fid.unique;
> 	inode->i_version	= vnode->status.data_version;
> @@ -375,8 +375,7 @@ int afs_validate(struct afs_vnode *vnode, struct key *key)
> /*
>  * read the attributes of an inode
>  */
> -int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
> -		      struct kstat *stat)
> +int afs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
> {
> 	struct inode *inode;
> 
> @@ -385,6 +384,8 @@ int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
> 	_enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
> 
> 	generic_fillattr(inode, stat);
> +
> +	stat->result_mask &= ~(STATX_ATIME | STATX_CTIME | STATX_BLOCKS);
> 	return 0;
> }
> 
> 
> --
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Cheers, Andreas






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