Date: Sun, 19 May 2002 08:59:07 -0700 From: Alfred Perlstein <bright@mu.org> To: Robert Watson <rwatson@FreeBSD.org> Cc: current@FreeBSD.org Subject: Re: Bug in -current flock()? Message-ID: <20020519155907.GS20683@elvis.mu.org> In-Reply-To: <Pine.NEB.3.96L.1020519102843.72574Q-100000@fledge.watson.org> References: <Pine.NEB.3.96L.1020519102843.72574Q-100000@fledge.watson.org>
next in thread | previous in thread | raw e-mail | index | archive | help
* Robert Watson <rwatson@FreeBSD.org> [020519 07:30] wrote:
>
> I don't know much (anything) about the advisory locking code, but was
> puzzled to see the following at the bottom of the flock() system call code
> in kern_descrip.c:
>
> if (uap->how & LOCK_EX)
> lf.l_type = F_WRLCK;
> else if (uap->how & LOCK_SH)
> lf.l_type = F_RDLCK;
> else {
> error = EBADF;
> goto done2;
> }
> FILE_LOCK(fp);
> fp->f_flag |= FHASLOCK;
> FILE_UNLOCK(fp);
> error = VOP_ADVLOCK(vp, (caddr_t)fp, F_SETLK, &lf,
> (uap->how & LOCK_NB) ? F_FLOCK : F_FLOCK | F_WAIT);
> done2:
> fdrop(fp, td);
> mtx_unlock(&Giant);
> return (error);
> }
>
> My reading of that is that the fp->f_flag field will be unconditionally
> updated to include FHASLOCK, even if VOP_ADVLOCK() returns an error. Is
> this correct?
Yes, but it's harmless. All that may happen is that at exit/close
time possibly calling VOP_ADVLOCK to unlock the file when it doesn't
need to.
--
-Alfred Perlstein [alfred@freebsd.org]
'Instead of asking why a piece of software is using "1970s technology,"
start asking why software is ignoring 30 years of accumulated wisdom.'
Tax deductible donations for FreeBSD: http://www.freebsdfoundation.org/
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20020519155907.GS20683>