On Tue, 2020-09-22 at 15:50 -0600, Warner Losh wrote: > I think it's a great leap sideways, but I've done cp /dev/null foo to > clear > it out for 35 years now... It's why it feels like a workaround. > > Though it is a legit optimization, no matter the feelings. As for > clearer, > I'm less sure since then I have to remember what the : operator does. > > Warner >
For me, :> is idiomatic (but ugly). On the other hand, the cp /dev/null had a nice dogfooding aspect to it... when we broke cp by accident, its use in the build system was the first alarm to go off. --Ian > On Tue, Sep 22, 2020 at 3:48 PM Alan Somers <asom...@freebsd.org> > wrote: > > > It doesn't feel like a workaround to me. I think Kyle's version is > > clearer than the original. > > > > On Tue, Sep 22, 2020 at 3:45 PM Warner Losh <i...@bsdimp.com> wrote: > > > > > > > > > > > On Tue, Sep 22, 2020 at 3:42 PM Kyle Evans <kev...@freebsd.org> > > > wrote: > > > > > > > cp is already fixed, people are still feeling the fallout of > > > > being > > > > within those revisions and needing to bootstrap their own cp. > > > > We can > > > > reduce the number of components these invocations rely on > > > > trivially to > > > > shell built-in mechanics, why not do so? > > > > > > > > > > Fair point. I just bristle at putting workarounds in for valid > > > /bin/sh > > > syntax because we opposed for a few days. so long as it's an > > > unconditional > > > clearing of the file to be zero length, I'm OK with that. > > > > > > Warner > > > > > > > > > > On Tue, Sep 22, 2020 at 4:40 PM Warner Losh <i...@bsdimp.com> > > > > wrote: > > > > > > > > > > So why do we need a workaround at all? cp /dev/null has been > > > > > fixed, > > > > > > > > and that's way more important to get right. > > > > > > > > > > I don't want to paper-over issues with this at all, though if > > > > > we use > > > > > > > > the host's (now broken) cp, I suppose that might be OK in the > > > > short term. > > > > If that's the case, then maybe this is OK. > > > > > > > > > > Otherwise, I'd strongly prefer we fix cp. > > > > > > > > > > Warner > > > > > > > > > > On Tue, Sep 22, 2020 at 3:31 PM Alan Somers < > > > > > asom...@freebsd.org> > > > > > > > > wrote: > > > > > > > > > > > > +1. > > > > > > > > > > > > On Tue, Sep 22, 2020 at 3:27 PM Kyle Evans < > > > > > > kev...@freebsd.org> > > > > > > > > wrote: > > > > > > > > > > > > > > I'm running a build at the suggestion of mjg to confirm > > > > > > > there aren't > > > > > > > any others hiding that can be converted, and I will > > > > > > > commit after I've > > > > > > > verified that this is it. > > > > > > > > > > > > > > On Tue, Sep 22, 2020 at 4:02 PM Alan Somers < > > > > > > > asom...@freebsd.org> > > > > > > > > wrote: > > > > > > > > > > > > > > > > LGTM. > > > > > > > > > > > > > > > > On Tue, Sep 22, 2020 at 2:59 PM Kyle Evans < > > > > > > > > kev...@freebsd.org> > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > Perhaps: > > > > > > > > > > > > > > > > > > diff --git a/stand/i386/zfsboot/Makefile > > > > > > > > b/stand/i386/zfsboot/Makefile > > > > > > > > > index ff315abc0ef..7e362b43a39 100644 > > > > > > > > > --- a/stand/i386/zfsboot/Makefile > > > > > > > > > +++ b/stand/i386/zfsboot/Makefile > > > > > > > > > @@ -81,7 +81,7 @@ zfsboot.ld: zfsboot.ldr zfsboot.bin > > > > > > > > > ${BTXKERN} > > > > > > > > > -o ${.TARGET} -P 1 zfsboot.bin > > > > > > > > > > > > > > > > > > zfsboot.ldr: > > > > > > > > > - cp /dev/null ${.TARGET} > > > > > > > > > + :> ${.TARGET} > > > > > > > > > > > > > > > > > > zfsboot.bin: zfsboot.out > > > > > > > > > ${OBJCOPY} -S -O binary zfsboot.out > > > > > > > > > ${.TARGET} > > > > > > > > > diff --git a/stand/libsa/Makefile > > > > > > > > > b/stand/libsa/Makefile > > > > > > > > > index effece9e01b..63cd46a9c54 100644 > > > > > > > > > --- a/stand/libsa/Makefile > > > > > > > > > +++ b/stand/libsa/Makefile > > > > > > > > > @@ -122,7 +122,7 @@ beforedepend: > > > > > > > > > ln -sf ${SRCTOP}/include/arpa/inet.h > > > > > > > > > arpa/inet.h; \ > > > > > > > > > ln -sf ${SRCTOP}/include/arpa/t > > > > > > > > > ftp.h arpa/tftp.h; \ > > > > > > > > > for i in _time.h _strings.h _string.h; do \ > > > > > > > > > - [ -f xlocale/$$i ] || cp /dev/null > > > > > > > > > xlocale/$$i; \ > > > > > > > > > + [ -f xlocale/$$i ] || :> xlocale/$$i; > > > > > > > > > \ > > > > > > > > > done; \ > > > > > > > > > for i in ${STAND_H_INC}; do \ > > > > > > > > > ln -sf ${SASRC}/stand.h $$i; \ > > > > > > > > > > > > > > > > > > > > > > > > > > > On Tue, Sep 22, 2020 at 3:58 PM Alan Somers < > > > > > > > > > asom...@freebsd.org> > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > Looks like two places in stand. Is there any > > > > > > > > > > reason why > > > > > > > > Mateusz's suggestion wouldn't work? > > > > > > > > > > > > > > > > > > > > > rg -g Makefile 'cp.*/dev/null' > > > > > > > > > > > > > > > > > > > > stand/libsa/Makefile > > > > > > > > > > 125: [ -f xlocale/$$i ] || cp /dev/null > > > > > > > > > > xlocale/$$i; \ > > > > > > > > > > > > > > > > > > > > stand/i386/zfsboot/Makefile > > > > > > > > > > 82: cp /dev/null ${.TARGET} > > > > > > > > > > > > > > > > > > > > On Tue, Sep 22, 2020 at 2:54 PM Mateusz Guzik < > > > > > > > > mjgu...@gmail.com> wrote: > > > > > > > > > > > > > > > > > > > > > > Can we instead add a workaround to the build > > > > > > > > > > > tree? > > > > > > > > > > > > > > > > > > > > > > Where is cp /dev/null coming from anyway? Perhaps > > > > > > > > > > > this can be > > > > > > > > patched > > > > > > > > > > > to touch the target file. > > > > > > > > > > > > > > > > > > > > > > On 9/22/20, Alan Somers <asom...@freebsd.org> > > > > > > > > > > > wrote: > > > > > > > > > > > > On Tue, Sep 22, 2020 at 2:48 PM Kyle Evans < > > > > > > > > kev...@freebsd.org> wrote: > > > > > > > > > > > > > > > > > > > > > > > > > On Fri, Sep 11, 2020 at 3:49 PM Alan Somers < > > > > > > > > asom...@freebsd.org> wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > Author: asomers > > > > > > > > > > > > > > Date: Fri Sep 11 20:49:36 2020 > > > > > > > > > > > > > > New Revision: 365643 > > > > > > > > > > > > > > URL: > > > > > > > > > > > > > > https://svnweb.freebsd.org/changeset/base/365643 > > > > > > > > > > > > > > > > > > > > > > > > > > > > Log: > > > > > > > > > > > > > > cp: fall back to read/write if > > > > > > > > > > > > > > copy_file_range fails > > > > > > > > > > > > > > > > > > > > > > > > > > > > Even though copy_file_range has a file- > > > > > > > > > > > > > > system agnostic > > > > > > > > version, it > > > > > > > > > > > > > still > > > > > > > > > > > > > > fails on devfs (perhaps because the file > > > > > > > > > > > > > > descriptor is > > > > > > > > non-seekable?) > > > > > > > > > > > > > In > > > > > > > > > > > > > > that case, fallback to old-fashioned > > > > > > > > > > > > > > read/write. Fixes > > > > > > > > > > > > > > "cp /dev/null /tmp/null" > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > > > > > > > > > > > > > Any objection to adding a quick UPDATING > > > > > > > > > > > > > entry for this? > > > > > > > > I'm seeing > > > > > > > > > > > > > occasional reports of this breakage as recent > > > > > > > > > > > > > as today on > > > > > > > > IRC from > > > > > > > > > > > > > folks that were a little bit thrown off by > > > > > > > > > > > > > this because it > > > > > > > > throws up > > > > > > > > > > > > > fairly far into the build and looks like a > > > > > > > > > > > > > stand build > > > > > > > > regression > > > > > > > > > > > > > instead of a cp regression. > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > > > > > > > > > > > > > > > Kyle Evans > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > No objection. Can you suggest the proper > > > > > > > > > > > > wording? > > > > > > > > > > > > _______________________________________________ > > > > > > > > > > > > svn-src-all@freebsd.org mailing list > > > > > > > > > > > > https://lists.freebsd.org/mailman/listinfo/svn-src-all > > > > > > > > > > > > To unsubscribe, send any mail to " > > > > > > > > svn-src-all-unsubscr...@freebsd.org" > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > > > > > > > Mateusz Guzik <mjguzik gmail.com> _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"