On Tue, Feb 16, 2021 at 06:00:34PM +0000, Al Viro wrote:
> Sigh... OK, so we want something like
> user_path_create()
> vfs_mknod()
> created = true
> grab bindlock
> ....
> drop bindlock
> if failed && created
> vfs_unlink()
> done_path_create()
> in unix_bind()... That would push ->bindlock all way down in the hierarchy,
> so that should be deadlock-free, but it looks like that'll be fucking ugly ;-/
>
> Let me try and play with that a bit, maybe it can be massaged to something
> relatively sane...
OK... Completely untested series follows. Preliminary massage in first
6 patches, then actual "add cleanup on failure", then minor followup
cleanup.
af_unix: take address assignment/hash insertion into a new helper
unix_bind(): allocate addr earlier
unix_bind(): separate BSD and abstract cases
unix_bind(): take BSD and abstract address cases into new helpers
fold unix_mknod() into unix_bind_bsd()
unix_bind_bsd(): move done_path_create() call after dealing with ->bindlock
unix_bind_bsd(): unlink if we fail after successful mknod
__unix_find_socket_byname(): don't pass hash and type separately
Branch is in git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git #misc.af_unix,
individual patches in followups
