Date: Tue, 28 Aug 2012 17:50:25 +0200 From: Luigi Rizzo <rizzo@iet.unipi.it> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-current@freebsd.org, current@freebsd.org, Andriy Gapon <avg@freebsd.org> Subject: Re: per file descriptor device callbacks ? Message-ID: <20120828155025.GA66068@onelab2.iet.unipi.it> In-Reply-To: <201208271227.54785.jhb@freebsd.org> References: <20120827073403.GA49223@onelab2.iet.unipi.it> <503B2803.1010104@FreeBSD.org> <201208271227.54785.jhb@freebsd.org>
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On Mon, Aug 27, 2012 at 12:27:54PM -0400, John Baldwin wrote: > On Monday, August 27, 2012 3:55:47 am Andriy Gapon wrote: > > on 27/08/2012 10:34 Luigi Rizzo said the following: > > > This requires to track calls to open/ioctl/poll/mmap/close. > > > The difficulty i have is with mmap() and close(), because FreeBSD > > > seems to handle these calls per-cdev rather than per-file-descriptor > > > (for instance, no 'struct file' argument is available in mmap(), and > > > the d_close method is only called on the last close() on the device). > > > > devfs_set_cdevpriv(9), etc > > mmap() is still problematic, but if you have the freedom to create your > own VM objects, then d_mmap_single() can let you handle that fairly > easily. Would dev_clone(9) be a better way to do what i need ? This way the struct cdev would be unique per file descriptor, could be used as a key on the page fault callbacks (i still do not have callbacks on dev_pager_ctor/dtor though). cheers luigi
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