From a81c1d8411fd014a2c5dfff5dfc5c16ea68ac1b2 Mon Sep 17 00:00:00 2001 From: Mark Kettenis Date: Tue, 6 Aug 2013 08:22:38 +0000 Subject: Make it possible to have multiple clonable devices per major. --- sys/kern/spec_vnops.c | 10 +++++++--- sys/sys/specdev.h | 8 +++++++- 2 files changed, 14 insertions(+), 4 deletions(-) (limited to 'sys') diff --git a/sys/kern/spec_vnops.c b/sys/kern/spec_vnops.c index 49d301de241..20ce5f2da03 100644 --- a/sys/kern/spec_vnops.c +++ b/sys/kern/spec_vnops.c @@ -1,4 +1,4 @@ -/* $OpenBSD: spec_vnops.c,v 1.75 2013/07/29 18:51:42 kettenis Exp $ */ +/* $OpenBSD: spec_vnops.c,v 1.76 2013/08/06 08:22:37 kettenis Exp $ */ /* $NetBSD: spec_vnops.c,v 1.29 1996/04/22 01:42:38 christos Exp $ */ /* @@ -691,6 +691,9 @@ spec_open_clone(struct vop_open_args *ap) DNPRINTF("cloning vnode\n"); + if (minor(vp->v_rdev) >= (1 << CLONE_SHIFT)) + return (ENXIO); + for (i = 1; i < sizeof(vp->v_specbitmap) * NBBY; i++) if (isclr(vp->v_specbitmap, i)) { setbit(vp->v_specbitmap, i); @@ -700,7 +703,8 @@ spec_open_clone(struct vop_open_args *ap) if (i == sizeof(vp->v_specbitmap) * NBBY) return (EBUSY); /* too many open instances */ - error = cdevvp(makedev(major(vp->v_rdev), i), &cvp); + error = cdevvp(makedev(major(vp->v_rdev), + (i << CLONE_SHIFT) | minor(vp->v_rdev)), &cvp); if (error) { clrbit(vp->v_specbitmap, i); return (error); /* out of vnodes */ @@ -746,7 +750,7 @@ spec_close_clone(struct vop_close_args *ap) return (error); /* device close failed */ pvp = vp->v_specparent; /* get parent device */ - clrbit(pvp->v_specbitmap, minor(vp->v_rdev)); + clrbit(pvp->v_specbitmap, minor(vp->v_rdev) >> CLONE_SHIFT); vrele(pvp); return (0); /* clone closed */ diff --git a/sys/sys/specdev.h b/sys/sys/specdev.h index 4de99ce4ff6..1d21e83530d 100644 --- a/sys/sys/specdev.h +++ b/sys/sys/specdev.h @@ -1,4 +1,4 @@ -/* $OpenBSD: specdev.h,v 1.32 2013/06/11 16:42:18 deraadt Exp $ */ +/* $OpenBSD: specdev.h,v 1.33 2013/08/06 08:22:37 kettenis Exp $ */ /* $NetBSD: specdev.h,v 1.12 1996/02/13 13:13:01 mycroft Exp $ */ /* @@ -66,6 +66,12 @@ struct cloneinfo { #define v_specparent v_specinfo->si_ci.ci_parent #define v_specbitmap v_specinfo->si_ci.ci_bitmap +/* + * We use the upper 16 bits of the minor to record the clone instance. + * This gives us 8 bits for encoding the real minor number. + */ +#define CLONE_SHIFT 8 + /* * Special device management */ -- cgit v1.2.3