new udev autoactivation

new udev rule 69-dm-lvm.rules replaces
69-dm-lvm-meta.rules and lvm2-pvscan.service

udev rule calls pvscan directly on the added device

pvscan output indicates if a complete VG can be activated

udev env var LVM_VG_NAME_COMPLETE is used to pass complete
VG name from pvscan to the udev rule

udev rule uses systemd-run to run vgchange -aay <vgname>

2 files changed, 88 insertions, 1 deletions

diff --git a/udev/69-dm-lvm.rules.in b/udev/69-dm-lvm.rules.in
new file mode 100644
index 000000000..39e5b9807
--- /dev/null
+++ b/udev/69-dm-lvm.rules.in
@@ -0,0 +1,87 @@
+# Copyright (C) 2012,2021 Red Hat, Inc. All rights reserved.
+#
+# This file is part of LVM.
+#
+# This rule requires blkid to be called on block devices before so only devices
+# used as LVM PVs are processed (ID_FS_TYPE="LVM2_member").
+
+SUBSYSTEM!="block", GOTO="lvm_end"
+(LVM_EXEC_RULE)
+
+ENV{DM_UDEV_DISABLE_OTHER_RULES_FLAG}=="1", GOTO="lvm_end"
+
+# Only process devices already marked as a PV - this requires blkid to be called before.
+ENV{ID_FS_TYPE}!="LVM2_member", GOTO="lvm_end"
+ENV{DM_MULTIPATH_DEVICE_PATH}=="1", GOTO="lvm_end"
+ACTION=="remove", GOTO="lvm_end"
+
+# Create /dev/disk/by-id/lvm-pv-uuid-<PV_UUID> symlink for each PV
+ENV{ID_FS_UUID_ENC}=="?*", SYMLINK+="disk/by-id/lvm-pv-uuid-$env{ID_FS_UUID_ENC}"
+
+# If the PV is a special device listed below, scan only if the device is
+# properly activated. These devices are not usable after an ADD event,
+# but they require an extra setup and they are ready after a CHANGE event.
+# Also support coldplugging with ADD event but only if the device is already
+# properly activated.
+# This logic should be eventually moved to rules where those particular
+# devices are processed primarily (MD and loop).
+
+# DM device:
+KERNEL!="dm-[0-9]*", GOTO="next"
+ENV{DM_UDEV_PRIMARY_SOURCE_FLAG}=="1", ENV{DM_ACTIVATION}=="1", GOTO="lvm_scan"
+GOTO="lvm_end"
+
+# MD device:
+LABEL="next"
+KERNEL!="md[0-9]*", GOTO="next"
+IMPORT{db}="LVM_MD_PV_ACTIVATED"
+ACTION=="add", ENV{LVM_MD_PV_ACTIVATED}=="1", GOTO="lvm_scan"
+ACTION=="change", ENV{LVM_MD_PV_ACTIVATED}!="1", TEST=="md/array_state", ENV{LVM_MD_PV_ACTIVATED}="1", GOTO="lvm_scan"
+ACTION=="add", KERNEL=="md[0-9]*p[0-9]*", GOTO="lvm_scan"
+ENV{LVM_MD_PV_ACTIVATED}!="1", ENV{SYSTEMD_READY}="0"
+GOTO="lvm_end"
+
+# Loop device:
+LABEL="next"
+KERNEL!="loop[0-9]*", GOTO="next"
+ACTION=="add", ENV{LVM_LOOP_PV_ACTIVATED}=="1", GOTO="lvm_scan"
+ACTION=="change", ENV{LVM_LOOP_PV_ACTIVATED}!="1", TEST=="loop/backing_file", ENV{LVM_LOOP_PV_ACTIVATED}="1", GOTO="lvm_scan"
+ENV{LVM_LOOP_PV_ACTIVATED}!="1", ENV{SYSTEMD_READY}="0"
+GOTO="lvm_end"
+
+LABEL="next"
+ACTION!="add", GOTO="lvm_end"
+
+LABEL="lvm_scan"
+
+ENV{SYSTEMD_READY}="1"
+
+# pvscan will check if this device completes a VG,
+# i.e. all PVs in the VG are now present with the
+# arrival of this PV.  If so, it prints to stdout:
+# LVM_VG_NAME_COMPLETE='foo'
+#
+# When the VG is complete it can be activated, so
+# vgchange -aay <vgname> is run.  It is run via
+# systemd since it can take longer to run than
+# udev wants to block when processing rules.
+# (if there are hundreds of LVs to activate,
+# the vgchange can take many seconds.)
+#
+# pvscan only reads the single device specified,
+# and uses temp files under /run/lvm to check if
+# other PVs in the VG are present.
+#
+# If event_activation=0 in lvm.conf, this pvscan
+# (using checkcomplete) will do nothing, so that
+# no event-based autoactivation will be happen.
+#
+# TODO: adjust the output of vgchange -aay so that
+# it's better suited to appearing in the journal.
+
+IMPORT{program}="(LVM_EXEC)/lvm pvscan --cache --listvg --checkcomplete --vgonline --udevoutput --journal=output $env{DEVNAME}"
+ENV{LVM_VG_NAME_COMPLETE}=="?*", RUN+="/usr/bin/systemd-run -r --no-block --property DefaultDependencies=no --unit lvm-activate-$env{LVM_VG_NAME_COMPLETE} lvm vgchange -aay --nohints $env{LVM_VG_NAME_COMPLETE}"
+GOTO="lvm_end"
+
+LABEL="lvm_end"
+
diff --git a/udev/Makefile.in b/udev/Makefile.in
index e32cba921..e777dda16 100644
--- a/udev/Makefile.in
+++ b/udev/Makefile.in
@@ -18,7 +18,7 @@ top_builddir = @top_builddir@
 include $(top_builddir)/make.tmpl
 
 DM_RULES=10-dm.rules 13-dm-disk.rules 95-dm-notify.rules
-LVM_RULES=11-dm-lvm.rules 69-dm-lvm-metad.rules
+LVM_RULES=11-dm-lvm.rules 69-dm-lvm.rules
 
 DM_DIR=$(shell $(GREP) "\#define DM_DIR" $(top_srcdir)/libdm/misc/dm-ioctl.h | $(AWK) '{print $$3}')