Date: Fri, 13 Aug 1999 22:07:28 +0200 From: Poul-Henning Kamp <phk@critter.freebsd.dk> To: Julian Elischer <julian@whistle.com> Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/miscfs/specfs spec_vnops.c src/sys/sys conf.h Message-ID: <4648.934574848@critter.freebsd.dk> In-Reply-To: Your message of "Fri, 13 Aug 1999 12:51:48 PDT." <Pine.BSF.3.95.990813124653.3531H-100000@current1.whistle.com>
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You havn't looked too closely at the stuff I committed, have you ? :-) There is no need to add another entry point, open and close does just fine, all we needed to do was to call close more often. Poul-Henning In message <Pine.BSF.3.95.990813124653.3531H-100000@current1.whistle.com>, Julian Elischer writes: > > >On Fri, 13 Aug 1999, Poul-Henning Kamp wrote: > >> >> I'm not sure I copy you here, (actually I very sure I don't :-) >> >> Could you explain what it is that the driver wants to know here ? > >The driver in one system I was playing with, needed to know when the last >writer releasd the device so that the driver could downgrade the device to >read-only mode. The reason for this was that when this happenned, the >device would complete an internal back-up of the data, and label the >backup as 'stable'. > >Unless you keep track of all closes and mode changes, you can't do this. >Also Justin was saying he wnated to do this for some of his own reasons as >well. > >The simplest way to do it would be to add an advisory entrypoint >that was called for ALL closes, not just the last one, and also when a >fork happenned as you now have more users. I wasn't too fussed about that >one, but Justin had some good reasons at the time... > >julian > >> >> Poul-Henning >> >> In message <Pine.BSF.3.95.990813111357.3531A-100000@current1.whistle.com>, Julian Elischer writes: >> >(yey) >> >however I discovered in the SLICE code that it woudl be good if the third >> >operation was: >> >proc2: close >> > devsw->modechenge(R/W, 0, proc2 ) >> > >> >on fork: >> >proc2: close >> > devsw->modechenge(0, R/W, proc2 ) >> > >> > >> > >> >where the close2() operation is called on all close() operations >> > >> >On Fri, 13 Aug 1999, Poul-Henning Kamp wrote: >> > >> >> phk 1999/08/13 09:29:28 PDT >> >> >> >> Modified files: >> >> sys/miscfs/specfs spec_vnops.c >> >> sys/sys conf.h >> >> Log: >> >> Add support for device drivers which want to track all open/close >> >> operations. This allows a device driver better insight into >> >> what is going on that the current: >> >> >> >> proc1: open /dev/foo R/O >> >> devsw->open( R/O, proc1 ) >> >> proc2: open /dev/foo R/W >> >> devsw->open( R/W, proc2 ) >> >> proc2: close >> >> /* nothing, but device is >> >> really only R/O open */ >> >> proc1: close >> >> devsw->close( R/O, proc1 ) >> >> >> >> Revision Changes Path >> >> 1.95 +18 -59 src/sys/miscfs/specfs/spec_vnops.c >> >> 1.72 +3 -2 src/sys/sys/conf.h >> >> >> >> >> >> >> > >> > >> >> -- >> Poul-Henning Kamp FreeBSD coreteam member >> phk@FreeBSD.ORG "Real hackers run -current on their laptop." >> FreeBSD -- It will take a long time before progress goes too far! >> >> > > -- Poul-Henning Kamp FreeBSD coreteam member phk@FreeBSD.ORG "Real hackers run -current on their laptop." FreeBSD -- It will take a long time before progress goes too far! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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