From 9ed6eb741f0bc0178167e7063751eb2bb4ac6de5 Mon Sep 17 00:00:00 2001

From: Harald Hoyer <harald@redhat.com>

Date: Mon, 15 Jan 2018 15:44:46 +0100

Subject: [PATCH] dracut-functions.sh:check_vol_slaves() speedup LV -> VG name

Instead of trying all /dev/mapper/* devices to match the maj:min, and

get the VG name with "lvm lvs", use the dm/name from /sys and dmsetup

splitname.

This should speedup execution with lots of LVs.

---

 dracut-functions.sh | 64 ++++++++++++++++++++++++-----------------------------

 1 file changed, 29 insertions(+), 35 deletions(-)

diff --git a/dracut-functions.sh b/dracut-functions.sh

index e99c4533..badd2a22 100755

--- a/dracut-functions.sh

+++ b/dracut-functions.sh

@@ -560,45 +560,39 @@ for_each_host_dev_and_slaves()

 # but you cannot create the logical volume without the volume group.

 # And the volume group might be bigger than the devices the LV needs.

 check_vol_slaves() {

-    local _lv _vg _pv _dm

-    for i in /dev/mapper/*; do

-        [[ $i == /dev/mapper/control ]] && continue

-        _lv=$(get_maj_min $i)

-        _dm=/sys/dev/block/$_lv/dm

-        [[ -f $_dm/uuid  && $(<$_dm/uuid) =~ LVM-* ]] || continue

-        if [[ $_lv = $2 ]]; then

-            _vg=$(lvm lvs --noheadings -o vg_name $i 2>/dev/null)

-            # strip space

-            _vg="${_vg//[[:space:]]/}"

-            if [[ $_vg ]]; then

-                for _pv in $(lvm vgs --noheadings -o pv_name "$_vg" 2>/dev/null)

-                do

-                    check_block_and_slaves $1 $(get_maj_min $_pv) && return 0

-                done

-            fi

-        fi

-    done

+    local _lv _vg _pv _dm _majmin

+    _majmin="$2"

+    _lv="/dev/block/$_majmin"

+    _dm=/sys/dev/block/$_majmin/dm

+    [[ -f $_dm/uuid  && $(<$_dm/uuid) =~ LVM-* ]] || return 1

+    _vg=$(dmsetup splitname --noheadings -o vg_name $(<"$_dm/name") )

+    # strip space

+    _vg="${_vg//[[:space:]]/}"

+    if [[ $_vg ]]; then

+        for _pv in $(lvm vgs --noheadings -o pv_name "$_vg" 2>/dev/null)

+        do

+            check_block_and_slaves $1 $(get_maj_min $_pv) && return 0

+        done

+    fi

     return 1

 }

 check_vol_slaves_all() {

-    local _lv _vg _pv

-    for i in /dev/mapper/*; do

-        [[ $i == /dev/mapper/control ]] && continue

-        _lv=$(get_maj_min $i)

-        if [[ $_lv = $2 ]]; then

-            _vg=$(lvm lvs --noheadings -o vg_name $i 2>/dev/null)

-            # strip space

-            _vg="${_vg//[[:space:]]/}"

-            if [[ $_vg ]]; then

-                for _pv in $(lvm vgs --noheadings -o pv_name "$_vg" 2>/dev/null)

-                do

-                    check_block_and_slaves_all $1 $(get_maj_min $_pv)

-                done

-                return 0

-            fi

-        fi

-    done

+    local _lv _vg _pv _majmin

+    _majmin="$2"

+    _lv="/dev/block/$_majmin"

+    _dm="/sys/dev/block/$_majmin/dm"

+    [[ -f $_dm/uuid  && $(<$_dm/uuid) =~ LVM-* ]] || return 1

+    _vg=$(dmsetup splitname --noheadings -o vg_name $(<"$_dm/name") )

+    # strip space

+    _vg="${_vg//[[:space:]]/}"

+    if [[ $_vg ]]; then

+        for _pv in $(lvm vgs --noheadings -o pv_name "$_vg" 2>/dev/null)

+        do

+            check_block_and_slaves_all $1 $(get_maj_min $_pv)

+        done

+        return 0

+    fi

     return 1

 }