From fa1ed2be551a1c2de7fca92d1fd5f6297567aa94 Mon Sep 17 00:00:00 2001
From: Javi Fontan <jfontan@opennebula.org>
Date: Thu, 25 May 2017 14:08:38 +0200
Subject: [PATCH 1/2] B #5170: add a lock to lvm actions in fs_lvm

---
 src/tm_mad/fs_lvm/clone  | 19 ++++++++++++++++---
 src/tm_mad/fs_lvm/delete |  4 +++-
 src/tm_mad/fs_lvm/mvds   |  8 ++++++++
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/src/tm_mad/fs_lvm/clone b/src/tm_mad/fs_lvm/clone
index 2f5ebe7719..025ea0c367 100755
--- a/src/tm_mad/fs_lvm/clone
+++ b/src/tm_mad/fs_lvm/clone
@@ -90,11 +90,24 @@ LV_NAME="lv-one-$VM_ID-$DISK_ID"
 VG_NAME="vg-one-$DS_SYS_ID"
 DEV="/dev/${VG_NAME}/${LV_NAME}"
 
-CLONE_CMD=$(cat <<EOF
-    set -e -o pipefail
-    mkdir -p $DST_DIR
+# Execute lvcreate with a lock in the frontend
+mkdir -p $DST_DS_PATH
+
+CREATE_CMD=$(cat <<EOF
+    $SUDO $SYNC
+    $SUDO $LVSCAN
 
     $SUDO $LVCREATE --wipesignatures n -L${SIZE}M -n $LV_NAME $VG_NAME
+EOF
+)
+
+LOCK_FILE="$DST_DS_PATH/lock"
+flock -w 120 $LOCK_FILE ssh_exec_and_log "$DST_HOST" "$CREATE_CMD" \
+        "Error creating LV named $LV_NAME"
+
+CLONE_CMD=$(cat <<EOF
+    set -e -o pipefail
+
     $QEMU_IMG convert -O raw "$SRC_PATH" "$DEV"
     rm -f "$DST_PATH"
     ln -s "$DEV" "$DST_PATH"
diff --git a/src/tm_mad/fs_lvm/delete b/src/tm_mad/fs_lvm/delete
index 736e20e0ac..bc921e6747 100755
--- a/src/tm_mad/fs_lvm/delete
+++ b/src/tm_mad/fs_lvm/delete
@@ -60,5 +60,7 @@ DELETE_CMD=$(cat <<EOF
 EOF
 )
 
-ssh_exec_and_log "$DST_HOST" "$DELETE_CMD" "Error deleting $DST_PATH"
+LOCK_FILE="$DST_DS_PATH/lock"
+flock -w 120 $LOCK_FILE ssh_exec_and_log "$DST_HOST" "$DELETE_CMD" \
+        "Error deleting $DST_PATH"
 
diff --git a/src/tm_mad/fs_lvm/mvds b/src/tm_mad/fs_lvm/mvds
index be6b4723dd..f6f75f8ce5 100755
--- a/src/tm_mad/fs_lvm/mvds
+++ b/src/tm_mad/fs_lvm/mvds
@@ -54,6 +54,10 @@ DEV="/dev/${VG_NAME}/${LV_NAME}"
 
 DUMP_CMD=$(cat <<EOF
     $DD if=$DEV of=$DST_PATH bs=64k
+EOF
+)
+
+DELETE_CMD=$(cat <<EOF
     $SUDO $LVREMOVE -f $DEV
 EOF
 )
@@ -66,4 +70,8 @@ log "Dumping $SRC to $DST"
 ssh_exec_and_log "$SRC_HOST" "$DUMP_CMD" \
     "Error dumping $SRC to $DST"
 
+LOCK_FILE="$DST_DS_PATH/lock"
+flock -w 120 $LOCK_FILE ssh_exec_and_log "$SRC_HOST" "$REMOVE_CMD" \
+    "Error deleting LV $LV_NAME"
+
 exit 0

From e15cdcce836b344800569f21a0f0fd2da7ebc337 Mon Sep 17 00:00:00 2001
From: Vlastimil Holer <vholer@opennebula.org>
Date: Thu, 15 Jun 2017 12:28:52 +0200
Subject: [PATCH 2/2] B #5170: Common scripts function "exclusive", use in
 fs_lvm

---
 src/mad/sh/scripts_common.sh | 30 ++++++++++++++++++++++++++++++
 src/tm_mad/fs_lvm/clone      |  9 ++++-----
 src/tm_mad/fs_lvm/delete     | 12 +++++++++---
 src/tm_mad/fs_lvm/mvds       |  6 +++---
 4 files changed, 46 insertions(+), 11 deletions(-)

diff --git a/src/mad/sh/scripts_common.sh b/src/mad/sh/scripts_common.sh
index 6d917232ab..4c1cc9fa7a 100644
--- a/src/mad/sh/scripts_common.sh
+++ b/src/mad/sh/scripts_common.sh
@@ -129,6 +129,36 @@ function error_message
     ) 1>&2
 }
 
+# Ensures the code is executed exclusively
+function exclusive
+{
+    LOCK_FILE="/var/lock/one/$1"
+    TIMEOUT=$2
+    shift 2
+
+    ( umask 0027; touch "${LOCK_FILE}" 2>/dev/null )
+
+    # open lockfile
+    exec 2>/dev/null {FD}>"${LOCK_FILE}"
+    if [ $? -ne 0 ]; then
+        log_error "Could not create or open lock ${LOCK_FILE}"
+        exit -2
+    fi
+
+    # acquire lock
+    flock -w "${TIMEOUT}" "${FD}"
+    if [ $? -ne 0 ]; then
+        log_error "Could not acquire exclusive lock on ${LOCK_FILE}"
+        exit -2
+    fi
+
+    "$@"
+
+    EXEC_RC=$?
+    eval "exec ${FD}>&-"
+    return $EXEC_RC
+}
+
 # Executes a command, if it fails returns error message and exits
 # If a second parameter is present it is used as the error message when
 # the command fails
diff --git a/src/tm_mad/fs_lvm/clone b/src/tm_mad/fs_lvm/clone
index 025ea0c367..a891b11a4b 100755
--- a/src/tm_mad/fs_lvm/clone
+++ b/src/tm_mad/fs_lvm/clone
@@ -91,22 +91,21 @@ VG_NAME="vg-one-$DS_SYS_ID"
 DEV="/dev/${VG_NAME}/${LV_NAME}"
 
 # Execute lvcreate with a lock in the frontend
-mkdir -p $DST_DS_PATH
-
 CREATE_CMD=$(cat <<EOF
+    set -e -o pipefail
     $SUDO $SYNC
     $SUDO $LVSCAN
-
     $SUDO $LVCREATE --wipesignatures n -L${SIZE}M -n $LV_NAME $VG_NAME
 EOF
 )
 
-LOCK_FILE="$DST_DS_PATH/lock"
-flock -w 120 $LOCK_FILE ssh_exec_and_log "$DST_HOST" "$CREATE_CMD" \
+LOCK="tm-fs_lvm-${DS_SYS_ID}.lock"
+exclusive "${LOCK}" 120 ssh_exec_and_log "$DST_HOST" "$CREATE_CMD" \
         "Error creating LV named $LV_NAME"
 
 CLONE_CMD=$(cat <<EOF
     set -e -o pipefail
+    mkdir -p $DST_DIR
 
     $QEMU_IMG convert -O raw "$SRC_PATH" "$DEV"
     rm -f "$DST_PATH"
diff --git a/src/tm_mad/fs_lvm/delete b/src/tm_mad/fs_lvm/delete
index bc921e6747..df42515f5b 100755
--- a/src/tm_mad/fs_lvm/delete
+++ b/src/tm_mad/fs_lvm/delete
@@ -39,6 +39,8 @@ source $TMCOMMON
 DST_PATH=`arg_path $DST`
 DST_HOST=`arg_host $DST`
 
+DS_SYS_ID=$(echo $DST_PATH | grep -E '\/disk\.[[:digit:]]+$' | $AWK -F '/' '{print $(NF-2)}')
+
 # Delete the device if it's a clone (LVM snapshot)
 DELETE_CMD=$(cat <<EOF
     set -x
@@ -60,7 +62,11 @@ DELETE_CMD=$(cat <<EOF
 EOF
 )
 
-LOCK_FILE="$DST_DS_PATH/lock"
-flock -w 120 $LOCK_FILE ssh_exec_and_log "$DST_HOST" "$DELETE_CMD" \
+if [ -n "${DS_SYS_ID}" ]; then
+    LOCK="tm-fs_lvm-${DS_SYS_ID}.lock"
+    exclusive "${LOCK}" 120 ssh_exec_and_log "$DST_HOST" "$DELETE_CMD" \
         "Error deleting $DST_PATH"
-
+else
+    ssh_exec_and_log "$DST_HOST" "$DELETE_CMD" \
+        "Error deleting $DST_PATH"
+fi
diff --git a/src/tm_mad/fs_lvm/mvds b/src/tm_mad/fs_lvm/mvds
index f6f75f8ce5..40a5979d2f 100755
--- a/src/tm_mad/fs_lvm/mvds
+++ b/src/tm_mad/fs_lvm/mvds
@@ -70,8 +70,8 @@ log "Dumping $SRC to $DST"
 ssh_exec_and_log "$SRC_HOST" "$DUMP_CMD" \
     "Error dumping $SRC to $DST"
 
-LOCK_FILE="$DST_DS_PATH/lock"
-flock -w 120 $LOCK_FILE ssh_exec_and_log "$SRC_HOST" "$REMOVE_CMD" \
-    "Error deleting LV $LV_NAME"
+LOCK="tm-fs_lvm-${DS_SYS_ID}.lock"
+exclusive "${LOCK}" 120 ssh_exec_and_log "$SRC_HOST" "$DELETE_CMD" \
+    "Error dumping $SRC to $DST"
 
 exit 0