On Thu, Apr 16, 2009 at 06:06:45PM +0200, Ingo Molnar wrote:
NAK is certainly given. Dealing with force-umount is laughable - there
are so few instances, that we simply ought to take (all two? of) them
remount is potentially nastier, but then it *is* nasty. Again, it's only
per-fs stuff, so the obvious first step is taking BKL down into the instances.
It doesn't protect anything in VFS; all uses are fs internal, so that'll
take review of individual filesystems.
NOTE: do not assume that code in fs/foo/* is correct; "it doesn't take BKL
elsewhere" does _not_ mean that we don't have races. IOW, the same review
ought to look for such beasts and deal with them. Mere "oh, no BKL anywhere
in that fs" is not enough to discard the ->remount_fs() instance.
No. It's all about fs internals protected from themselves. ->remount_fs()
tends to be grotty shite, so nobody had enough courage to do proper review
and fixes. And it's not a place where we would really suffer from contention,
so it didn't get high priority that way either.