add kernel source repo checkout, update existing branches

develop/update_git.sh

-#!/bin/sh -x
+#!/bin/bash -x
+
+# creates new branch for the major kernel version or update such branch
 
 fatal()
 {
@@ -6,21 +8,52 @@ fatal()
     exit 1
 }
 
+ECSOURCE=../../etercifs-source
+MERGEOPT="--no-edit"
+
 MV="$1"
-[ -n "$MV" ] || fatal
+[ -n "$MV" ] || fatal "Run with version, f.i. ./update_git.sh 4.11"
+
+KTAG=v$MV
+KBRANCH=linux-$MV.y
 
 ELIST="etersoft-common etersoft-share-flags etersoft-wine"
 
-cd ../../cifs-2.6 || fatal
+if [ ! -d $ECSOURCE ] ; then
+    cd $(dirname $ECSOURCE) || fatal
+    git clone https://gitlab.eterfund.ru/etersoft/etercifs-source.git || fatal
+    cd etercifs-source || fatal
+    git remote add upstream https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
+else
+    cd $ECSOURCE || fatal
+fi
+
+git fetch upstream
 
+git tag | grep "$KTAG" || fatal "There is no $KTAG tag in the git repo."
+
+if git branch | grep -q $KTAG-etercifs ; then
+    LASTTAG=$(git describe --tags upstream/$KBRANCH) || fatal
+    echo "Just update branch $KTAG-etercifs to latest commit from $KBRANCH with tag $LASTTAG"
+    git checkout $KTAG-etercifs || fatal
+    #git merge $MERGEOPT upstream/$KBRANCH || fatal
+    git merge $MERGEOPT $LASTTAG || fatal
+    exit
+fi
+
+echo
+echo "Update branches..."
 for i in $ELIST ; do
     git checkout $i || fatal
-    git merge $MV || fatal
+    git merge $MERGEOPT $KTAG || fatal
 done
 
-# create branch from tag
-git checkout -b $MV-etercifs $MV || fatal
+echo
+echo "Create branch from the tag and merge all to it..."
+git checkout -b $MV-etercifs $KTAG || fatal
 
 for i in $ELIST ; do
-    git merge $i || fatal
+    git merge $MERGEOPT $i || fatal
 done
+
+echo "You are in branch $MV-etercifs, copy fs/cifs to "