Date: Sat, 30 Nov 2002 20:18:46 +0100 From: Nicolas Souchu <nsouch@free.fr> To: Doug Rabson <dfr@nlsystems.com> Cc: Nicolas Souchu <nsouch@fr.alcove.com>, freebsd-hackers@freebsd.org Subject: processes private data & vm_mmap Message-ID: <20021130201846.A2089@armor.fastether> In-Reply-To: <Pine.BSF.4.33.0106281944210.866-100000@herring.nlsystems.com>; from dfr@nlsystems.com on Thu, Jun 28, 2001 at 07:48:21PM %2B0100 References: <20010628182533.B17804@avon.alcove-fr> <Pine.BSF.4.33.0106281944210.866-100000@herring.nlsystems.com>
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On Thu, Jun 28, 2001 at 07:48:21PM +0100, Doug Rabson wrote: > On Thu, 28 Jun 2001, Nicolas Souchu wrote: > > > Hi folks, > > > > I have a char driver that must be opened by more than one process. The minor > > index is not sufficient for this. Is there any process private data (void *) > > in the devfs structure (or the opposite) I could point to with the minor index > > of my device? > > The only way I know of to do this is to get a new struct file with > falloc() and install your own fileops. You can then set p->p_dupfd to the > new file descriptor and return ENXIO. The caller will magically use the > new struct file. For an example, see streamsopen() in > sys/dev/streams/streams.c. I'm back on the subject 1.5 years later :) Apparently, falloc does the job for typical write/read operations. But I want to mmap a char device with per-process data. I mean during open of the char device, some process dependent data is attached to the vnode then I want to mmap. Currently, cdevsw mmap is only device (dev_t) oriented without any file (vnode) consideration. Even the thread is not passed to the d_mmap routine. I'm porting code from Linux which has per-process data attached to files. Nicholas PS: all this is for http://www.freebsd.org/~nsouch/ggiport.html KGI/FreeBSD project. -- Nicholas Souchu - nsouch@free.fr - nsouch@FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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