Improve activation monitoring option processing

. Add "monitoring" option to "activation" section of lvm.conf
. Have clvmd consult the lvm.conf "activation/monitoring" too.
. Introduce toollib.c:get_activation_monitoring_mode().
. Error out when both --monitor and --ignoremonitoring are provided.
. Add --monitor and --ignoremonitoring support to lvcreate.  Update
  lvcreate man page accordingly.
. Clarify that '--monitor' controls the start and stop of monitoring in
  the {vg,lv}change man pages.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

15 files changed, 81 insertions, 17 deletions

diff --git a/WHATS_NEW b/WHATS_NEW
index d21007c9..6d291acb 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,8 @@
 Version 2.02.63 - 
 ================================
+  Add "monitoring" option to "activation" section of lvm.conf.
+  Have clvmd consult the lvm.conf "activation/monitoring".
+  Add --monitor and --ignoremonitoring support to lvcreate.
   Allow dynamic extension of array of areas selected as allocation candidates.
   Export and use only valid cookie value in test suite.
   Remove const modifier for struct volume_group* from process_each_lv_in_vg().
diff --git a/daemons/clvmd/lvm-functions.c b/daemons/clvmd/lvm-functions.c
index 02d401b9..60b6db4d 100644
--- a/daemons/clvmd/lvm-functions.c
+++ b/daemons/clvmd/lvm-functions.c
@@ -542,8 +542,12 @@ int do_lock_lv(unsigned char command, unsigned char lock_flags, char *resource)
 	if (lock_flags & LCK_MIRROR_NOSYNC_MODE)
 		init_mirror_in_sync(0);
 
-	if (!(lock_flags & LCK_DMEVENTD_MONITOR_MODE))
-		init_dmeventd_monitor(DEFAULT_DMEVENTD_MONITOR);
+	if (!(lock_flags & LCK_DMEVENTD_MONITOR_MODE)) {
+		int dmeventd_mode =
+			find_config_tree_bool(cmd, "activation/monitoring",
+					      DEFAULT_DMEVENTD_MONITOR);
+		init_dmeventd_monitor(dmeventd_mode);
+	}
 
 	cmd->partial_activation = 0;
 
diff --git a/doc/example.conf b/doc/example.conf
index 511e20c3..89e13edb 100644
--- a/doc/example.conf
+++ b/doc/example.conf
@@ -428,6 +428,10 @@ activation {
     # which used mlockall() to pin the whole process's memory while activating
     # devices.
     # use_mlockall = 0
+
+    # Monitoring is enabled by default when activating logical volumes.
+    # Set to 0 to disable monitoring or use the --ignoremonitoring option.
+    # monitoring = 1
 }
 
 
diff --git a/lib/metadata/lv_manip.c b/lib/metadata/lv_manip.c
index 0929aba1..c9d17599 100644
--- a/lib/metadata/lv_manip.c
+++ b/lib/metadata/lv_manip.c
@@ -3061,6 +3061,8 @@ int lv_create_single(struct volume_group *vg,
 
 	backup(vg);
 
+	init_dmeventd_monitor(lp->activation_monitoring);
+
 	if (lp->snapshot) {
 		if (!activate_lv_excl(cmd, lv)) {
 			log_error("Aborting. Failed to activate snapshot "
diff --git a/lib/metadata/metadata-exported.h b/lib/metadata/metadata-exported.h
index 2f1405fc..b02a22cd 100644
--- a/lib/metadata/metadata-exported.h
+++ b/lib/metadata/metadata-exported.h
@@ -535,6 +535,7 @@ struct lvcreate_params {
 	int minor; /* all */
 	int log_count; /* mirror */
 	int nosync; /* mirror */
+	int activation_monitoring; /* all */
 
 	char *origin; /* snap */
 	const char *vg_name; /* all */
diff --git a/liblvm/lvm_lv.c b/liblvm/lvm_lv.c
index 86175aeb..82e6d4b0 100644
--- a/liblvm/lvm_lv.c
+++ b/liblvm/lvm_lv.c
@@ -111,6 +111,7 @@ static void _lv_set_default_params(struct lvcreate_params *lp,
 	lp->zero = 1;
 	lp->major = -1;
 	lp->minor = -1;
+	lp->activation_monitoring = DEFAULT_DMEVENTD_MONITOR;
 	lp->vg_name = vg->name;
 	lp->lv_name = lvname; /* FIXME: check this for safety */
 	lp->pvh = &vg->pvs;
diff --git a/man/lvchange.8.in b/man/lvchange.8.in
index 08a83c49..c3cb3b28 100644
--- a/man/lvchange.8.in
+++ b/man/lvchange.8.in
@@ -56,7 +56,7 @@ of your data.
 Set the minor number.
 .TP
 .I \-\-monitor y|n
-Controls whether or not a mirrored logical volume is monitored by
+Start or stop monitoring a mirrored or snapshot logical volume with
 dmeventd, if it is installed.
 If a device used by a monitored mirror reports an I/O error,
 the failure is handled according to 
diff --git a/man/lvcreate.8.in b/man/lvcreate.8.in
index 314c3545..56df7226 100644
--- a/man/lvcreate.8.in
+++ b/man/lvcreate.8.in
@@ -7,6 +7,8 @@ lvcreate \- create a logical volume in an existing volume group
 [\-\-alloc AllocationPolicy]
 [\-A|\-\-autobackup y|n] [\-C|\-\-contiguous y|n] [\-d|\-\-debug]
 [\-h|\-?|\-\-help] [\-\-noudevsync]
+[\-\-ignoremonitoring]
+[\-\-monitor {y|n}]
 [\-i|\-\-stripes Stripes [\-I|\-\-stripesize StripeSize]]
 {\-l|\-\-extents LogicalExtentsNumber[%{VG|PVS|FREE}] |
  \-L|\-\-size LogicalVolumeSize[bBsSkKmMgGtTpPeE]}
@@ -26,6 +28,8 @@ VolumeGroupName [PhysicalVolumePath[:PE[-PE]]...]
  \-L|\-\-size LogicalVolumeSize[bBsSkKmMgGtTpPeE]}
 [\-c|\-\-chunksize ChunkSize]
 [\-\-noudevsync]
+[\-\-ignoremonitoring]
+[\-\-monitor {y|n}]
 \-n|\-\-name SnapshotLogicalVolumeName
 {{\-s|\-\-snapshot}
 OriginalLogicalVolumePath | 
@@ -129,6 +133,18 @@ It will continue irrespective of any possible udev processing
 in the background.  You should only use this if udev is not running
 or has rules that ignore the devices LVM2 creates.
 .TP
+.I \-\-monitor y|n
+Start or avoid monitoring a mirrored or snapshot logical volume with
+dmeventd, if it is installed. 
+If a device used by a monitored mirror reports an I/O error,
+the failure is handled according to 
+\fBmirror_image_fault_policy\fP and \fBmirror_log_fault_policy\fP
+set in \fBlvm.conf\fP.
+.TP
+.I \-\-ignoremonitoring
+Make no attempt to interact with dmeventd unless \-\-monitor
+is specified.
+.TP
 .I \-p, \-\-permission r|rw
 Set access permissions to read only or read and write.
 .br
diff --git a/man/vgchange.8.in b/man/vgchange.8.in
index 5013c1e8..10d6afc9 100644
--- a/man/vgchange.8.in
+++ b/man/vgchange.8.in
@@ -78,7 +78,7 @@ are not marked as clustered.
 Generate new random UUID for specified Volume Groups.
 .TP
 .BR \-\-monitor " " { y | n }
-Controls whether or not a mirrored logical volume is monitored by
+Start or stop monitoring a mirrored or snapshot logical volume with
 dmeventd, if it is installed.
 If a device used by a monitored mirror reports an I/O error,
 the failure is handled according to 
diff --git a/tools/commands.h b/tools/commands.h
index ad0b385e..58d6d7b9 100644
--- a/tools/commands.h
+++ b/tools/commands.h
@@ -150,6 +150,8 @@ xx(lvcreate,
    "\t[-C|--contiguous {y|n}]\n"
    "\t[-d|--debug]\n"
    "\t[-h|-?|--help]\n"
+   "\t[--ignoremonitoring]\n"
+   "\t[--monitor {y|n}]\n"
    "\t[-i|--stripes Stripes [-I|--stripesize StripeSize]]\n"
    "\t{-l|--extents LogicalExtentsNumber[%{VG|PVS|FREE}] |\n"
    "\t -L|--size LogicalVolumeSize[bBsSkKmMgGtTpPeE]}\n"
@@ -177,6 +179,8 @@ xx(lvcreate,
    "\t[-C|--contiguous {y|n}]\n"
    "\t[-d|--debug]\n"
    "\t[-h|-?|--help]\n"
+   "\t[--ignoremonitoring]\n"
+   "\t[--monitor {y|n}]\n"
    "\t[-i|--stripes Stripes [-I|--stripesize StripeSize]]\n"
    "\t{-l|--extents LogicalExtentsNumber[%{VG|FREE|ORIGIN}] |\n"
    "\t -L|--size LogicalVolumeSize[bBsSkKmMgGtTpPeE]}\n"
@@ -192,11 +196,11 @@ xx(lvcreate,
    "\t[PhysicalVolumePath...]\n\n",
 
    addtag_ARG, alloc_ARG, autobackup_ARG, chunksize_ARG, contiguous_ARG,
-   corelog_ARG, extents_ARG, major_ARG, minor_ARG, mirrorlog_ARG, mirrors_ARG,
-   name_ARG, nosync_ARG, noudevsync_ARG, permission_ARG, persistent_ARG,
-   readahead_ARG, regionsize_ARG, size_ARG, snapshot_ARG, stripes_ARG,
-   stripesize_ARG, test_ARG, type_ARG, virtualoriginsize_ARG, virtualsize_ARG,
-   zero_ARG)
+   corelog_ARG, extents_ARG, ignoremonitoring_ARG, major_ARG, minor_ARG,
+   mirrorlog_ARG, mirrors_ARG, monitor_ARG, name_ARG, nosync_ARG, noudevsync_ARG,
+   permission_ARG, persistent_ARG, readahead_ARG, regionsize_ARG, size_ARG,
+   snapshot_ARG, stripes_ARG, stripesize_ARG, test_ARG, type_ARG,
+   virtualoriginsize_ARG, virtualsize_ARG, zero_ARG)
 
 xx(lvdisplay,
    "Display information about a logical volume",
diff --git a/tools/lvchange.c b/tools/lvchange.c
index 2d7955e8..534c9930 100644
--- a/tools/lvchange.c
+++ b/tools/lvchange.c
@@ -518,7 +518,7 @@ static int lvchange_single(struct cmd_context *cmd, struct logical_volume *lv,
 			   void *handle __attribute((unused)))
 {
 	int doit = 0, docmds = 0;
-	int archived = 0;
+	int dmeventd_mode, archived = 0;
 	struct logical_volume *origin;
 
 	if (!(lv->vg->status & LVM_WRITE) &&
@@ -575,9 +575,10 @@ static int lvchange_single(struct cmd_context *cmd, struct logical_volume *lv,
 		return ECMD_FAILED;
 	}
 
-	init_dmeventd_monitor(arg_int_value(cmd, monitor_ARG,
-					    (is_static() || arg_count(cmd, ignoremonitoring_ARG)) ?
-					    DMEVENTD_MONITOR_IGNORE : DEFAULT_DMEVENTD_MONITOR));
+	if (!get_activation_monitoring_mode(cmd, &dmeventd_mode))
+		return ECMD_FAILED;
+
+	init_dmeventd_monitor(dmeventd_mode);
 
 	/*
 	 * FIXME: DEFAULT_BACKGROUND_POLLING should be "unspecified".
diff --git a/tools/lvcreate.c b/tools/lvcreate.c
index 211cfebb..10b5aa59 100644
--- a/tools/lvcreate.c
+++ b/tools/lvcreate.c
@@ -482,6 +482,9 @@ static int _lvcreate_params(struct lvcreate_params *lp,
 		return 0;
 	}
 
+	if (!get_activation_monitoring_mode(cmd, &lp->activation_monitoring))
+		return_0;
+
 	if (!_lvcreate_name_params(lp, cmd, &argc, &argv) ||
 	    !_read_size_params(lp, lcp, cmd) ||
 	    !_read_stripe_params(lp, cmd) ||
diff --git a/tools/toollib.c b/tools/toollib.c
index 54701692..b1528e25 100644
--- a/tools/toollib.c
+++ b/tools/toollib.c
@@ -1423,3 +1423,24 @@ int pvcreate_params_validate(struct cmd_context *cmd,
 	return 1;
 }
 
+int get_activation_monitoring_mode(struct cmd_context *cmd,
+				   int *monitoring_mode)
+{
+	*monitoring_mode = DEFAULT_DMEVENTD_MONITOR;
+
+	if (arg_count(cmd, monitor_ARG) &&
+	    arg_count(cmd, ignoremonitoring_ARG)) {
+		log_error("Conflicting monitor and ignoremonitoring options");
+		return 0;
+	}
+
+	if (arg_count(cmd, monitor_ARG))
+		*monitoring_mode = arg_int_value(cmd, monitor_ARG,
+						 DEFAULT_DMEVENTD_MONITOR);
+	else if (is_static() || arg_count(cmd, ignoremonitoring_ARG) ||
+		 !find_config_tree_bool(cmd, "activation/monitoring",
+					DEFAULT_DMEVENTD_MONITOR))
+		*monitoring_mode = DMEVENTD_MONITOR_IGNORE;
+	
+	return 1;
+}
diff --git a/tools/toollib.h b/tools/toollib.h
index d284de41..987814ed 100644
--- a/tools/toollib.h
+++ b/tools/toollib.h
@@ -112,4 +112,7 @@ int pvcreate_params_validate(struct cmd_context *cmd,
 			     int argc, char **argv,
 			     struct pvcreate_params *pp);
 
+int get_activation_monitoring_mode(struct cmd_context *cmd,
+				   int *monitoring_mode);
+
 #endif
diff --git a/tools/vgchange.c b/tools/vgchange.c
index 6d869f96..e013bdec 100644
--- a/tools/vgchange.c
+++ b/tools/vgchange.c
@@ -522,16 +522,17 @@ static int vgchange_single(struct cmd_context *cmd, const char *vg_name,
 			   struct volume_group *vg,
 			   void *handle __attribute((unused)))
 {
-	int r = ECMD_FAILED;
+	int dmeventd_mode, r = ECMD_FAILED;
 
 	if (vg_is_exported(vg)) {
 		log_error("Volume group \"%s\" is exported", vg_name);
 		return ECMD_FAILED;
 	}
 
-	init_dmeventd_monitor(arg_int_value(cmd, monitor_ARG,
-					    (is_static() || arg_count(cmd, ignoremonitoring_ARG)) ?
-					    DMEVENTD_MONITOR_IGNORE : DEFAULT_DMEVENTD_MONITOR));
+	if (!get_activation_monitoring_mode(cmd, &dmeventd_mode))
+		return ECMD_FAILED;
+
+	init_dmeventd_monitor(dmeventd_mode);
 
 	/*
 	 * FIXME: DEFAULT_BACKGROUND_POLLING should be "unspecified".