* [PATCH v2 2/3] libmutipath: don't close fd on dm_lib_release
2020-03-26 4:22 [PATCH v2 1/3] libmultipath: assign variable to make gcc happy Benjamin Marzinski
@ 2020-03-26 4:22 ` Benjamin Marzinski
2020-03-26 8:41 ` Martin Wilck
2020-03-26 4:22 ` [PATCH v2 3/3] libmultipath: allow force reload with no active paths Benjamin Marzinski
1 sibling, 1 reply; 4+ messages in thread
From: Benjamin Marzinski @ 2020-03-26 4:22 UTC (permalink / raw)
To: Christophe Varoqui; +Cc: device-mapper development, Martin Wilck
If dm_hold_control_open() isn't set, when dm_lib_release() is called, it
will close the control fd. The control fd will get re-opened on the next
dm_task_run() call, but if there is a dm_task_run() call already
in progress in another thread, it can fail. Since many of the
device-mapper callouts happen with the vecs lock held, this wasn't too
noticeable, but there is code that calls dm_task_run() without the
vecs lock held, notably the dmevent waiter code.
Since, as Martin pointed out, dm_hold_control_open() hasn't always
existed in libdevmapper, check if it's supported on compilation,
and update the version requirements if so.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
libmultipath/Makefile | 4 ++++
libmultipath/devmapper.c | 7 ++++++-
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/libmultipath/Makefile b/libmultipath/Makefile
index e5651e49..ad690a49 100644
--- a/libmultipath/Makefile
+++ b/libmultipath/Makefile
@@ -36,6 +36,10 @@ ifneq ($(call check_func,dm_task_deferred_remove,/usr/include/libdevmapper.h),0)
CFLAGS += -DLIBDM_API_DEFERRED
endif
+ifneq ($(call check_func,dm_hold_control_dev,/usr/include/libdevmapper.h),0)
+ CFLAGS += -DLIBDM_API_HOLD_CONTROL
+endif
+
OBJS = memory.o parser.o vector.o devmapper.o callout.o \
hwtable.o blacklist.o util.o dmparser.o config.o \
structs.o discovery.o propsel.o dict.o \
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
index bed8ddc6..13a1cf53 100644
--- a/libmultipath/devmapper.c
+++ b/libmultipath/devmapper.c
@@ -108,7 +108,9 @@ dm_lib_prereq (void)
{
char version[64];
int v[3];
-#if defined(LIBDM_API_DEFERRED)
+#if defined(LIBDM_API_HOLD_CONTROL)
+ int minv[3] = {1, 2, 111};
+#elif defined(LIBDM_API_DEFERRED)
int minv[3] = {1, 2, 89};
#elif defined(DM_SUBSYSTEM_UDEV_FLAG0)
int minv[3] = {1, 2, 82};
@@ -254,6 +256,9 @@ void libmp_dm_init(void)
memcpy(conf->version, version, sizeof(version));
put_multipath_config(conf);
dm_init(verbosity);
+#ifdef LIBDM_API_HOLD_CONTROL
+ dm_hold_control_dev(1);
+#endif
dm_udev_set_sync_support(libmp_dm_udev_sync);
}
--
2.17.2
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v2 3/3] libmultipath: allow force reload with no active paths
2020-03-26 4:22 [PATCH v2 1/3] libmultipath: assign variable to make gcc happy Benjamin Marzinski
2020-03-26 4:22 ` [PATCH v2 2/3] libmutipath: don't close fd on dm_lib_release Benjamin Marzinski
@ 2020-03-26 4:22 ` Benjamin Marzinski
1 sibling, 0 replies; 4+ messages in thread
From: Benjamin Marzinski @ 2020-03-26 4:22 UTC (permalink / raw)
To: Christophe Varoqui; +Cc: device-mapper development, Martin Wilck
If the partition information has changed on multipath devices (say,
because it was updated on another node that has access to the same
storage), users expect that running "multipathd reconfigure" will update
that. However, if the checkers for the multipath device are pending for
too long when the the device is reconfigured, multipathd will give up
waiting for them, and refuse to reload the device, since there are no
active paths. This means that no kpartx update will be triggered.
Multipath is fully capable of reloading a multipath device that has no
active paths. This has been possible for years. If multipath is supposed
to reload the device, it should do so, even if there are no active paths.
Generally, when multipath is force reloaded, kpartx will be updated.
However when a device is reloaded with no paths, the udev rules won't
run kpartx. But they also weren't running kpartx when the first valid
path appeared, even though the dm activation rules get run in this case.
This changes 11-dm-mpath.rules to run kpartx when a device goes from no
usable paths to having usable paths.
Reviewed-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
libmultipath/configure.c | 6 ------
multipath/11-dm-mpath.rules | 2 +-
2 files changed, 1 insertion(+), 7 deletions(-)
diff --git a/libmultipath/configure.c b/libmultipath/configure.c
index c95848a0..96c79610 100644
--- a/libmultipath/configure.c
+++ b/libmultipath/configure.c
@@ -710,12 +710,6 @@ select_action (struct multipath * mpp, vector curmp, int force_reload)
return;
}
- if (pathcount(mpp, PATH_UP) == 0) {
- mpp->action = ACT_IMPOSSIBLE;
- condlog(3, "%s: set ACT_IMPOSSIBLE (no usable path)",
- mpp->alias);
- return;
- }
if (force_reload) {
mpp->force_udev_reload = 1;
mpp->action = ACT_RELOAD;
diff --git a/multipath/11-dm-mpath.rules b/multipath/11-dm-mpath.rules
index 07320a14..cd522e8c 100644
--- a/multipath/11-dm-mpath.rules
+++ b/multipath/11-dm-mpath.rules
@@ -75,7 +75,7 @@ ENV{MPATH_DEVICE_READY}=="0", ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}="1"
ENV{MPATH_DEVICE_READY}!="0", ENV{.MPATH_DEVICE_READY_OLD}=="0",\
ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}="$env{DM_DISABLE_OTHER_RULES_FLAG_OLD}",\
ENV{DM_DISABLE_OTHER_RULES_FLAG_OLD}="",\
- ENV{DM_ACTIVATION}="1"
+ ENV{DM_ACTIVATION}="1", ENV{MPATH_UNCHANGED}="0"
# The code to check multipath state ends here. We need to set
# properties and symlinks regardless whether the map is usable or
--
2.17.2
^ permalink raw reply related [flat|nested] 4+ messages in thread