From owner-freebsd-bugs@FreeBSD.ORG Mon May 19 11:24:16 2003 Return-Path: Delivered-To: freebsd-bugs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C5FC637B401; Mon, 19 May 2003 11:24:16 -0700 (PDT) Received: from comp.chem.msu.su (comp-ext.chem.msu.su [158.250.32.157]) by mx1.FreeBSD.org (Postfix) with ESMTP id 65D2443F75; Mon, 19 May 2003 11:24:13 -0700 (PDT) (envelope-from yar@comp.chem.msu.su) Received: from comp.chem.msu.su (localhost [127.0.0.1]) by comp.chem.msu.su (8.12.3p2/8.12.3) with ESMTP id h4JIO7SH000460; Mon, 19 May 2003 22:24:08 +0400 (MSD) (envelope-from yar@comp.chem.msu.su) Received: (from yar@localhost) by comp.chem.msu.su (8.12.3p2/8.12.3/Submit) id h4JINwhk000457; Mon, 19 May 2003 22:23:58 +0400 (MSD) (envelope-from yar) Date: Mon, 19 May 2003 22:23:57 +0400 From: Yar Tikhiy To: Bruce Evans Message-ID: <20030519182357.GA99588@comp.chem.msu.su> References: <200305161646.h4GGkdDS000677@stylish.chem.msu.su> <20030517165718.B15076@gamplex.bde.org> <20030517091047.GA82314@comp.chem.msu.su> <20030517235738.U16304@gamplex.bde.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030517235738.U16304@gamplex.bde.org> User-Agent: Mutt/1.5.3i cc: freebsd-bugs@freebsd.org cc: FreeBSD-gnats-submit@freebsd.org cc: joerg@freebsd.org Subject: Re: kern/52338: fd(4) floppy disk driver & non-blocking I/O X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 19 May 2003 18:24:17 -0000 On Sun, May 18, 2003 at 12:39:03AM +1000, Bruce Evans wrote: > > It should set bp->bio_resid (to bp->bio_bcount) (bio_resid and bio_bcount > are the same as b_resid and b_bcount here; strategy routines only have > access to a struct bio so they must use the former). What do you think about the following straightforward patch to fd.c? It catches all spots where BIO_ERROR is set, but bio_resid isn't. In fd.c, bio_resid is never set in advance, so the simplest approach should work. OTOH, I wonder if bio_resid could be set equal to bio_bcount at the beginning of fdstrategy() and changed only if needed. Does this have any obscure implications? And my other thought is: What if physio() sets bio_resid equal to bio_bcount before calling DEV_STRATEGY()? Currently, physio() leaves bio_resid unset. An obvious drawback of this approach is that it would encourage poor coding in drivers, though. -- Yar --- fd.c.dist Fri Apr 11 15:39:24 2003 +++ fd.c Mon May 19 21:48:11 2003 @@ -1668,8 +1668,9 @@ fdstrategy(struct bio *bp) (u_long)major(bp->bio_dev), (u_long)minor(bp->bio_dev)); fdc = fd->fdc; if (fd->type == FDT_NONE || fd->ft == 0) { - bp->bio_error = ENXIO; + bp->bio_error = fd->type == FDT_NONE ? ENXIO : EAGAIN; bp->bio_flags |= BIO_ERROR; + bp->bio_resid = bp->bio_bcount; goto bad; } fdblk = 128 << (fd->ft->secsize); @@ -1677,6 +1678,7 @@ fdstrategy(struct bio *bp) if (fd->flags & FD_NONBLOCK) { bp->bio_error = EAGAIN; bp->bio_flags |= BIO_ERROR; + bp->bio_resid = bp->bio_bcount; goto bad; } if (bp->bio_blkno < 0) { @@ -1685,11 +1687,13 @@ fdstrategy(struct bio *bp) fdu, (u_long)bp->bio_blkno, bp->bio_bcount); bp->bio_error = EINVAL; bp->bio_flags |= BIO_ERROR; + bp->bio_resid = bp->bio_bcount; goto bad; } if ((bp->bio_bcount % fdblk) != 0) { bp->bio_error = EINVAL; bp->bio_flags |= BIO_ERROR; + bp->bio_resid = bp->bio_bcount; goto bad; } } @@ -1704,15 +1708,15 @@ fdstrategy(struct bio *bp) */ bp->bio_error = EINVAL; bp->bio_flags |= BIO_ERROR; + bp->bio_resid = bp->bio_bcount; goto bad; } blknum = bp->bio_blkno * DEV_BSIZE / fdblk; nblocks = fd->ft->size; if (blknum + bp->bio_bcount / fdblk > nblocks) { if (blknum >= nblocks) { - if (bp->bio_cmd == BIO_READ) - bp->bio_resid = bp->bio_bcount; - else { + bp->bio_resid = bp->bio_bcount; + if (bp->bio_cmd != BIO_READ) { bp->bio_error = ENOSPC; bp->bio_flags |= BIO_ERROR; } =================================================================