diff options
| author | riastradh <riastradh@NetBSD.org> | 2023-05-22 14:59:34 +0000 |
|---|---|---|
| committer | riastradh <riastradh@NetBSD.org> | 2023-05-22 14:59:34 +0000 |
| commit | 76031411ad161566edd0a91f01ee9860b5283cb2 (patch) | |
| tree | 9950bbc7d91ba0a320b5427db7c19bd8a24a607d /sys/dev | |
| parent | f02816aceb52e8120f3a33d4328cea33f609dd84 (diff) | |
dk(4): Prevent race between dkwedge_get_parent_name and wedge detach.
Still races with parent detach but maybe this is better.
XXX Maybe we should ditch dkwedge_get_parent_name -- it's used only
by rf_containsboot, which kinda suggests it shouldn't exist.
Diffstat (limited to 'sys/dev')
| -rw-r--r-- | sys/dev/dkwedge/dk.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/sys/dev/dkwedge/dk.c b/sys/dev/dkwedge/dk.c index 20d16630531..8920f51211f 100644 --- a/sys/dev/dkwedge/dk.c +++ b/sys/dev/dkwedge/dk.c @@ -1,4 +1,4 @@ -/* $NetBSD: dk.c,v 1.165 2023/05/22 14:59:25 riastradh Exp $ */ +/* $NetBSD: dk.c,v 1.166 2023/05/22 14:59:34 riastradh Exp $ */ /*- * Copyright (c) 2004, 2005, 2006, 2007 The NetBSD Foundation, Inc. @@ -30,7 +30,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.165 2023/05/22 14:59:25 riastradh Exp $"); +__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.166 2023/05/22 14:59:34 riastradh Exp $"); #ifdef _KERNEL_OPT #include "opt_dkwedge.h" @@ -1210,6 +1210,16 @@ dkwedge_lookup(dev_t dev) return device_lookup_private(&dk_cd, minor(dev)); } +static struct dkwedge_softc * +dkwedge_lookup_acquire(dev_t dev) +{ + device_t dv = device_lookup_acquire(&dk_cd, minor(dev)); + + if (dv == NULL) + return NULL; + return device_private(dv); +} + static int dk_open_parent(dev_t dev, int mode, struct vnode **vpp) { @@ -1925,8 +1935,11 @@ dkwedge_get_parent_name(dev_t dev) if (major(dev) != bmaj && major(dev) != cmaj) return NULL; - struct dkwedge_softc *sc = dkwedge_lookup(dev); + + struct dkwedge_softc *const sc = dkwedge_lookup_acquire(dev); if (sc == NULL) return NULL; - return sc->sc_parent->dk_name; + const char *const name = sc->sc_parent->dk_name; + device_release(sc->sc_dev); + return name; } |
