Re: [PATCH 1/4] Cache xattr security drop check for write v2

[Marco Stornelli <marco.stornelli@gmail.com>]

Hi,

Il 31/05/2011 22:07, Al Viro ha scritto:
> On Tue, May 31, 2011 at 07:42:26PM +0100, Steven Whitehouse wrote:
>
>> Yes, it should test for xattr too,
>
> Frankly, I suspect that the sanest way to handle that is this:
> 	* new superblock flag - MS_NOSEC
> 	* S_NOSEC is never set unless we have MS_NOSEC
> 	* mount_bdev() sets it before calling fill_super callback.
> 	* ocfs2 and fuse *clear* it in their fill_super
> 	* btrfs manually sets it in its ->mount()
> ... and if gfs2 or any other non-trivial fs wants to use that, it'll need
> to set MS_NOSEC in its ->mount() and take care of clearing S_NOSEC whenever
> we decide it might've gone stale (a-la your patch).
>

several fs now uses MS_NOSEC (because this flag is set in mount_bdev()) 
but I don't see any user of the function inode_has_no_xattr() in the 
latest version. If I well understand, a fs that wants to manage this 
feature has to set MS_NOSEC and calls when needed this function, isn't 
it? So at this point, why there aren't any user of this function?

Marco