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

From: Marco Stornelli
Date: Sat Jun 18 2011 - 03:12:17 EST


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
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