Date: Wed, 1 Sep 2004 14:14:49 -0500 (EST) From: Sam <sah@softcardsystems.com> To: Brian Fundakowski Feldman <green@freebsd.org> Cc: freebsd-arch@freebsd.org Subject: Re: disk_create and cdevsw_add Message-ID: <Pine.LNX.4.60.0409011407160.1792@athena> In-Reply-To: <20040901170154.GG45292@green.homeunix.org> References: <Pine.LNX.4.60.0409011215400.13505@athena> <20040901170154.GG45292@green.homeunix.org>
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On Wed, 1 Sep 2004, Brian Fundakowski Feldman wrote: > On Wed, Sep 01, 2004 at 12:32:58PM -0500, Sam wrote: >> 'lo again, >> >> kern/subr_disk.c:/^disk_create/ takes >> two cdevsw types, and I only vaguely >> understand why. Can someone explain it to me? >> >> I'm generally confused about resolving >> entry points into the driver. Does a >> block device only get an open() after >> registering it with disk_create? >> Supposing I want to set some ioctls for >> an aoecontrol utility (show all devices >> known, eg), what would aoecontrol open >> to ioctl? > > Create /dev/aoectl which exists only to do global aoe things; alternately, > you could use a sysctl interface, but that's not really as clean. I presume this means I should do a make_dev with a minor of 0 on module load as I see is recommended in DEV_MODULE(9). Should I then assume that unit 0 is this control file and be prepared to fail any strategy calls to it?
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