From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrey Borzenkov Date: Wed, 07 Jan 2004 11:14:44 +0000 Subject: Re: removable media revalidation - udev vs. devfs or static /dev Message-Id: <200401071414.44390.arvidjaar@mail.ru> List-Id: References: <200401012333.04930.arvidjaar@mail.ru> <200401071400.46286.arvidjaar@mail.ru> <20040107110516.GC3483@suse.de> In-Reply-To: <20040107110516.GC3483@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jens Axboe Cc: Olaf Hering , Andries Brouwer , Greg KH , linux-hotplug-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org On Wednesday 07 January 2004 14:05, Jens Axboe wrote: > On Wed, Jan 07 2004, Andrey Borzenkov wrote: > > On Wednesday 07 January 2004 12:50, Jens Axboe wrote: > > > > > So yeah, poll... > > > > > > > > Poll how? "kmediachangethread"? Or polling in userland? The latter > > > > would (probably) lead to endless IO errors. Not very good. > > > > > > No need to put it in the kernel, user space fits the bil nicely. > > > > unfortunately opening device in userland effectively locks tray making > > media change impossible. at least given current ->open semantic. > > > > even periodic access is quite annoying for users (tray closing while > > user attempts to insert CD) > > cdrom layer handles this with O_NONBLOCK basically meaning a 'not for > data' open. > > > we may agree that O_NDELAY does not affect locked state; currently > > this is not consistent across drivers (e.g. cdrom does not lock tray > > while sd does) > > cdrom has no special O_NDELAY checks. ok I meant O_NONBLOCK, sorry. they are synonyms anyway {pts/0}% grep NONBLO * fcntl.h:#define O_NONBLOCK 04000 fcntl.h:#define O_NDELAY O_NONBLOCK ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id78&alloc_id371&op=click _______________________________________________ Linux-hotplug-devel mailing list http://linux-hotplug.sourceforge.net Linux-hotplug-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-hotplug-devel