pvscan: rework to improve PVs without metadata

Restructure the pvscan code, and add new temporary files
that list pvids in a VG, used for processing PVs that
have no metadata.

The new temp files, in /run/lvm/pvs_lookup/<vgname>, allow a
proper pvscan --cache to be done on PVs that have no metadata.
pvscan --cache <dev> is only supposed to read <dev>, but when
<dev> has no metadata, this had not been possible.  The
command had to fall back to scanning all devices to read all
VG metadata to get the list of all PVIDs needed to check for
a complete VG.  Now, the temp file can be used in place of
reading metadata from all PVs on the system.

test/shell/hints.sh

@@ -330,7 +330,7 @@ rm $HINTS $PREV
 pvs
 cp $HINTS $PREV
 # this next pvscan creates newhints to trigger a refresh
-pvscan --cache "$dev5"
+pvscan --cache "$dev4"
 cat $NEWHINTS
 # this next pvs creates new hints
 pvs

test/shell/metadata-bad-text.sh

@@ -297,20 +297,13 @@ vgchange -an $vg
 _clear_online_files
 
 # pvscan of one dev with bad metadata will result
-# in the dev acting like a PV without metadata,
-# which causes pvscan to scan all devs to find the
-# VG it belongs to.  In this case it finds all the
-# other devs in the VG are online and activates the
-# VG.
+# in the pvid online file being created but the 
+# VG will not be known.
 pvscan --cache -aay "$dev1"
 ls "$RUNDIR/lvm/pvs_online/$PVID1"
-ls "$RUNDIR/lvm/pvs_online/$PVID2"
-ls "$RUNDIR/lvm/pvs_online/$PVID3"
-ls "$RUNDIR/lvm/vgs_online/$vg"
-
-lvs $vg
-check lv_field $vg/$lv1 lv_active "active"
-vgchange -an $vg
+not ls "$RUNDIR/lvm/pvs_online/$PVID2"
+not ls "$RUNDIR/lvm/pvs_online/$PVID3"
+not ls "$RUNDIR/lvm/vgs_online/$vg"
 
 _clear_online_files
 
@@ -321,18 +314,6 @@ not ls "$RUNDIR/lvm/pvs_online/$PVID2"
 ls "$RUNDIR/lvm/pvs_online/$PVID3"
 not ls "$RUNDIR/lvm/vgs_online/$vg"
 
-# scan the next pv with bad metadata, causes pvscan to scan
-# and find all PVs and activate
-pvscan --cache -aay "$dev2"
-ls "$RUNDIR/lvm/pvs_online/$PVID1"
-ls "$RUNDIR/lvm/pvs_online/$PVID2"
-ls "$RUNDIR/lvm/pvs_online/$PVID3"
-ls "$RUNDIR/lvm/vgs_online/$vg"
-
-check lv_field $vg/$lv1 lv_active "active"
-vgchange -an $vg
-
-
 vgck --updatemetadata $vg
 
 pvs 2>&1 | tee out

test/shell/pvscan-autoactivate.sh

@@ -16,6 +16,7 @@ RUNDIR="/run"
 test -d "$RUNDIR" || RUNDIR="/var/run"
 PVS_ONLINE_DIR="$RUNDIR/lvm/pvs_online"
 VGS_ONLINE_DIR="$RUNDIR/lvm/vgs_online"
+PVS_LOOKUP_DIR="$RUNDIR/lvm/pvs_lookup"
 
 # FIXME: kills logic for running system
 _clear_online_files() {
@@ -23,6 +24,7 @@ _clear_online_files() {
 	aux udev_wait
 	rm -f "$PVS_ONLINE_DIR"/*
 	rm -f "$VGS_ONLINE_DIR"/*
+	rm -f "$PVS_LOOKUP_DIR"/*
 }
 
 . lib/inittest
@@ -34,6 +36,7 @@ lvcreate -n $lv1 -l 4 -a n $vg1
 
 test -d "$PVS_ONLINE_DIR" || mkdir -p "$PVS_ONLINE_DIR"
 test -d "$VGS_ONLINE_DIR" || mkdir -p "$VGS_ONLINE_DIR"
+test -d "$PVS_LOOKUP_DIR" || mkdir -p "$PVS_LOOKUP_DIR"
 _clear_online_files
 
 # check pvscan with no args scans and activates all
@@ -93,12 +96,9 @@ pvscan --cache -aay "$dev1"
 check lv_field $vg1/$lv1 lv_active "active"
 lvchange -an $vg1
 
-# test case where dev without metadata is scanned first
-# which triggers scanning all, which finds both
-
 _clear_online_files
 pvscan --cache -aay "$dev1"
-check lv_field $vg1/$lv1 lv_active "active"
+check lv_field $vg1/$lv1 lv_active ""
 pvscan --cache -aay "$dev2"
 check lv_field $vg1/$lv1 lv_active "active"
 lvchange -an $vg1