Re: [patch 11/14] vfs: move executable checking into ->permission()

From: Miklos Szeredi
Date: Fri May 23 2008 - 05:52:49 EST


> > From: Miklos Szeredi <mszeredi@xxxxxxx>
> >
> > For execute permission on a regular files we need to check if file has
> > any execute bits at all, regardless of capabilites.
> >
> > This check is normally performed by generic_permission() but was also
> > added to the case when the filesystem defines its own ->permission()
> > method. In the latter case the filesystem should be responsible for
> > performing this check.
> >
> > So create a helper function exec_permission() that checks returns
> > -EACCESS if MAY_EXEC is present, the inode is a regular file and no
> > execute bits are present in inode->i_mode.
> >
> > Call this function from filesystems which don't call
> > generic_permission() from their ->permission() methods and which
> > aren't already performing this check. Also remove the check from
> > dentry_permission().
> >
> > The new code should be equivalent to the old.
>
> There's no point moving this into the filesystem.

Yes, there is. Fuse already has special code, because it need to
refresh the attributes first before doing the "are there any x bits in
mode?" check. And because there's some duplication, I've introduced a
helper. That's exactly how we handle this sort of thing.

Miklos
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