Blame SOURCES/0002-libmutipath-don-t-close-fd-on-dm_lib_release.patch

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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Benjamin Marzinski <bmarzins@redhat.com>
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Date: Sat, 21 Mar 2020 23:49:59 -0500
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Subject: [PATCH] libmutipath: don't close fd on dm_lib_release
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If dm_hold_control_open() isn't set, when dm_lib_release() is called, it
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will close the control fd. The control fd will get re-opened on the next
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dm_task_run() call, but if there is a dm_task_run() call already
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in progress in another thread, it can fail. Since many of the
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device-mapper callouts happen with the vecs lock held, this wasn't too
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noticeable, but there is code that calls dm_task_run() without the
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vecs lock held, notably the dmevent waiter code.
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Since, as Martin pointed out, dm_hold_control_open() hasn't always
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existed in libdevmapper, check if it's supported on compilation,
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and update the version requirements if so.
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Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
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---
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 libmultipath/Makefile    | 4 ++++
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 libmultipath/devmapper.c | 7 ++++++-
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 2 files changed, 10 insertions(+), 1 deletion(-)
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diff --git a/libmultipath/Makefile b/libmultipath/Makefile
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index e5651e49..ad690a49 100644
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--- a/libmultipath/Makefile
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+++ b/libmultipath/Makefile
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@@ -36,6 +36,10 @@ ifneq ($(call check_func,dm_task_deferred_remove,/usr/include/libdevmapper.h),0)
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 	CFLAGS += -DLIBDM_API_DEFERRED
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 endif
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+ifneq ($(call check_func,dm_hold_control_dev,/usr/include/libdevmapper.h),0)
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+	CFLAGS += -DLIBDM_API_HOLD_CONTROL
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+endif
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+
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 OBJS = memory.o parser.o vector.o devmapper.o callout.o \
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 	hwtable.o blacklist.o util.o dmparser.o config.o \
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 	structs.o discovery.o propsel.o dict.o \
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diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
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index bed8ddc6..13a1cf53 100644
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--- a/libmultipath/devmapper.c
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+++ b/libmultipath/devmapper.c
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@@ -108,7 +108,9 @@ dm_lib_prereq (void)
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 {
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 	char version[64];
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 	int v[3];
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-#if defined(LIBDM_API_DEFERRED)
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+#if defined(LIBDM_API_HOLD_CONTROL)
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+	int minv[3] = {1, 2, 111};
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+#elif defined(LIBDM_API_DEFERRED)
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 	int minv[3] = {1, 2, 89};
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 #elif defined(DM_SUBSYSTEM_UDEV_FLAG0)
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 	int minv[3] = {1, 2, 82};
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@@ -254,6 +256,9 @@ void libmp_dm_init(void)
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 	memcpy(conf->version, version, sizeof(version));
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 	put_multipath_config(conf);
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 	dm_init(verbosity);
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+#ifdef LIBDM_API_HOLD_CONTROL
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+	dm_hold_control_dev(1);
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+#endif
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 	dm_udev_set_sync_support(libmp_dm_udev_sync);
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 }
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-- 
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2.17.2
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