From owner-freebsd-hackers Tue Feb 23 17:37:15 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from smtp04.primenet.com (smtp04.primenet.com [206.165.6.134]) by hub.freebsd.org (Postfix) with ESMTP id 7C86D115DD for ; Tue, 23 Feb 1999 17:37:11 -0800 (PST) (envelope-from tlambert@usr09.primenet.com) Received: (from daemon@localhost) by smtp04.primenet.com (8.8.8/8.8.8) id SAA29700; Tue, 23 Feb 1999 18:58:14 -0700 (MST) Received: from usr09.primenet.com(206.165.6.209) via SMTP by smtp04.primenet.com, id smtpd029570; Tue Feb 23 18:58:11 1999 Received: (from tlambert@localhost) by usr09.primenet.com (8.8.5/8.8.5) id SAA24815; Tue, 23 Feb 1999 18:36:50 -0700 (MST) From: Terry Lambert Message-Id: <199902240136.SAA24815@usr09.primenet.com> Subject: Re: Panic in FFS/4.0 as of yesterday To: Don.Lewis@tsc.tdk.com (Don Lewis) Date: Wed, 24 Feb 1999 01:36:50 +0000 (GMT) Cc: tlambert@primenet.com, dfr@nlsystems.com, dillon@apollo.backplane.com, freebsd-hackers@FreeBSD.ORG In-Reply-To: <199902221428.GAA28942@salsa.gv.tsc.tdk.com> from "Don Lewis" at Feb 22, 99 06:28:56 am X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > } The correct way to do this, IMO, is a back-off/retry, which would > } unlock the lock and queue the operation for retry, which would > } reacquire the lock. > > Wouldn't you have to relock the parent before unlocking the lock (nasty > because it reverses the locking order and might cause a deadlock). You would have to unlock the child *then* unlock the parent to do this, yes. That was the point of the "relookup" reference for rename, which has to open a race window to do the locks correctly. Since the operation is supposed to appear atomic, a failure + retry is an OK outcome. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message