From 2f7a38511482176c806100665bb2edb625c1f3b6 Mon Sep 17 00:00:00 2001 From: Dima Dorfman Date: Sat, 24 Nov 2001 15:10:53 +0000 Subject: [PATCH] Create a snpbasedev variable which holds a reference to the first snp device cloned, and assign all further devices to depend on it. This allows us to call dev_depends() on it at module unload time to get rid of /dev/snp* (in the devfs case, anyway). For this to work, we must not destroy the device at close time. [Idea stolen from if_tun.] The above has the following sideaffects: (a) The snp device used by watch(8) will remain after watch(8) exits. This is probably how it should have been all along, and how it was before devfs came along. (b) Module unload doesn't panic if there are any /dev/snp* devices which haven't been used (and thus previously destroyed). Thus, we can reenable the unload functionality disabled in rev. 1.65. PR: 32012 --- sys/dev/snp/snp.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/sys/dev/snp/snp.c b/sys/dev/snp/snp.c index b8343a94129..e6cf7970e88 100644 --- a/sys/dev/snp/snp.c +++ b/sys/dev/snp/snp.c @@ -103,6 +103,7 @@ static MALLOC_DEFINE(M_SNP, "snp", "Snoop device data"); * module load time. */ static int snooplinedisc; +static udev_t snpbasedev = NOUDEV; static LIST_HEAD(, snoop) snp_sclist = LIST_HEAD_INITIALIZER(&snp_sclist); @@ -465,7 +466,6 @@ snpclose(dev, flags, fmt, td) free(snp->snp_buf, M_SNP); snp->snp_flags &= ~SNOOP_OPEN; dev->si_drv1 = NULL; - destroy_dev(dev); return (snp_detach(snp)); } @@ -614,6 +614,12 @@ snp_clone(arg, name, namelen, dev) return; *dev = make_dev(&snp_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600, "snp%d", u); + if (snpbasedev == NOUDEV) + snpbasedev = (*dev)->si_udev; + else { + (*dev)->si_flags |= SI_CHEAPCLONE; + dev_depends(udev2dev(snpbasedev, 0), *dev); + } } static int @@ -632,11 +638,11 @@ snp_modevent(mod, type, data) cdevsw_add(&snp_cdevsw); break; case MOD_UNLOAD: - /* XXX: temporarily prevent unload due to bugs in unloading. */ - return (EBUSY); if (!LIST_EMPTY(&snp_sclist)) return (EBUSY); EVENTHANDLER_DEREGISTER(dev_clone, eh_tag); + if (snpbasedev != NOUDEV) + destroy_dev(udev2dev(snpbasedev, 0)); ldisc_deregister(snooplinedisc); cdevsw_remove(&snp_cdevsw); break;