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authorhannken <hannken@NetBSD.org>2021-05-07 09:54:43 +0000
committerhannken <hannken@NetBSD.org>2021-05-07 09:54:43 +0000
commitaab45de7dcbd7ffd55af5588d190c41166c3418e (patch)
treef138be22b626718c145b5cdab587446c7e3d5e8b /sys/dev
parent6aca380d1ffb70376609f44d541ac9f312dfbe24 (diff)
Track the number of cdev and bdev opens and fail dm_detach()
on open devices unless detach is forced. PR kern/54969 (Disk cache is no longer flushed on shutdown)
Diffstat (limited to 'sys/dev')
-rw-r--r--sys/dev/dm/device-mapper.c49
1 files changed, 48 insertions, 1 deletions
diff --git a/sys/dev/dm/device-mapper.c b/sys/dev/dm/device-mapper.c
index 22f6e2db6fb..bdd17f60f62 100644
--- a/sys/dev/dm/device-mapper.c
+++ b/sys/dev/dm/device-mapper.c
@@ -1,4 +1,4 @@
-/* $NetBSD: device-mapper.c,v 1.61 2020/07/08 15:07:13 thorpej Exp $ */
+/* $NetBSD: device-mapper.c,v 1.62 2021/05/07 09:54:43 hannken Exp $ */
/*
* Copyright (c) 2010 The NetBSD Foundation, Inc.
@@ -260,8 +260,17 @@ dm_attach(device_t parent, device_t self, void *aux)
static int
dm_detach(device_t self, int flags)
{
+ bool busy;
dm_dev_t *dmv;
+ dmv = dm_dev_lookup(NULL, NULL, device_unit(self));
+ mutex_enter(&dmv->diskp->dk_openlock);
+ busy = (dmv->diskp->dk_openmask != 0 && (flags & DETACH_FORCE) == 0);
+ mutex_exit(&dmv->diskp->dk_openlock);
+ dm_dev_unbusy(dmv);
+ if (busy)
+ return EBUSY;
+
pmf_device_deregister(self);
/* Detach device from global device list */
@@ -334,6 +343,25 @@ dmdestroy(void)
static int
dmopen(dev_t dev, int flags, int mode, struct lwp *l)
{
+ dm_dev_t *dmv;
+ struct disk *dk;
+
+ dmv = dm_dev_lookup(NULL, NULL, minor(dev));
+ if (dmv) {
+ dk = dmv->diskp;
+ mutex_enter(&dk->dk_openlock);
+ switch (mode) {
+ case S_IFCHR:
+ dk->dk_copenmask |= 1;
+ break;
+ case S_IFBLK:
+ dk->dk_bopenmask |= 1;
+ break;
+ }
+ dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask;
+ mutex_exit(&dk->dk_openlock);
+ dm_dev_unbusy(dmv);
+ }
aprint_debug("dm open routine called %" PRIu32 "\n", minor(dev));
return 0;
@@ -342,8 +370,27 @@ dmopen(dev_t dev, int flags, int mode, struct lwp *l)
static int
dmclose(dev_t dev, int flags, int mode, struct lwp *l)
{
+ dm_dev_t *dmv;
+ struct disk *dk;
aprint_debug("dm close routine called %" PRIu32 "\n", minor(dev));
+
+ dmv = dm_dev_lookup(NULL, NULL, minor(dev));
+ if (dmv) {
+ dk = dmv->diskp;
+ mutex_enter(&dk->dk_openlock);
+ switch (mode) {
+ case S_IFCHR:
+ dk->dk_copenmask &= ~1;
+ break;
+ case S_IFBLK:
+ dk->dk_bopenmask &= ~1;
+ break;
+ }
+ dk->dk_openmask = dk->dk_copenmask | dk->dk_bopenmask;
+ mutex_exit(&dk->dk_openlock);
+ dm_dev_unbusy(dmv);
+ }
return 0;
}