Merge pull request #347 from vholer/bug-5170

B #5170: LVM exclusive locking

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

src/tm_mad/fs_lvm/clone

@@ -90,11 +90,23 @@ LV_NAME="lv-one-$VM_ID-$DISK_ID"
 VG_NAME="vg-one-$DS_SYS_ID"
 DEV="/dev/${VG_NAME}/${LV_NAME}"
 
+# Execute lvcreate with a lock in the frontend
+CREATE_CMD=$(cat <<EOF
+    set -e -o pipefail
+    $SUDO $SYNC
+    $SUDO $LVSCAN
+    $SUDO $LVCREATE --wipesignatures n -L${SIZE}M -n $LV_NAME $VG_NAME
+EOF
+)
+
+LOCK="tm-fs_lvm-${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
 
-    $SUDO $LVCREATE --wipesignatures n -L${SIZE}M -n $LV_NAME $VG_NAME
     $QEMU_IMG convert -O raw "$SRC_PATH" "$DEV"
     rm -f "$DST_PATH"
     ln -s "$DEV" "$DST_PATH"

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
@@ -60,5 +62,11 @@ DELETE_CMD=$(cat <<EOF
 EOF
 )
 
-ssh_exec_and_log "$DST_HOST" "$DELETE_CMD" "Error deleting $DST_PATH"
-
+if [ -n "${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

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="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