From owner-freebsd-current Wed Jul 7 17:43:56 1999 Delivered-To: freebsd-current@freebsd.org Received: from lestat.nas.nasa.gov (lestat.nas.nasa.gov [129.99.50.29]) by hub.freebsd.org (Postfix) with ESMTP id 2267714C4A; Wed, 7 Jul 1999 17:43:44 -0700 (PDT) (envelope-from thorpej@lestat.nas.nasa.gov) Received: from lestat (localhost [127.0.0.1]) by lestat.nas.nasa.gov (8.8.8/8.6.12) with ESMTP id RAA19553; Wed, 7 Jul 1999 17:43:28 -0700 (PDT) Message-Id: <199907080043.RAA19553@lestat.nas.nasa.gov> To: Peter Wemm Cc: Matthew Dillon , Julian Elischer , David Greenman , freebsd-hackers@FreeBSD.ORG, freebsd-current@FreeBSD.ORG Subject: Re: Heh heh, humorous lockup Reply-To: Jason Thorpe From: Jason Thorpe Date: Wed, 07 Jul 1999 17:43:27 -0700 Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Thu, 08 Jul 1999 08:36:19 +0800 Peter Wemm wrote: > Out of curiosity, how does it handle the problem of small 512 byte > directories? Does it consume a whole page or does it do something smarter? > Or does the ubc work apply to read/write only and the filesystem itself > continues to use the buffer cache interfaces for metadata and directories > still? Does the caching part of the bio system still exist? At the moment, only VREG is handled w/ UBC. We plan on addressing that in the future. In the case of file system blocks smaller than a page size, multiple blocks are read into the page. In the case of small directories, "we'll burn that bridge when we come to it" (i.e. when we attempt to deal with non-VREG). So, the caching part of the bio interface still exists for now (in part, this helps us to use file systems which haven't yet been converted to the UBC interface). -- Jason R. Thorpe To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message