From 4babd73fb938bead006b1210d17d73726baa80dc Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Mon, 24 Feb 2020 17:52:25 +0100
Subject: scripts/mount-store: Special case cifs wrt. stage4 permissions

If vmstore is cifs, we cannot rely on posix permissions. Add dnbd3
user to images group and set permissions of stage4 directory
accordingly, so dnbd3-server can write to it.
---
 scripts/mount-store | 81 ++++++++++++++++++++++++++++++++---------------------
 1 file changed, 49 insertions(+), 32 deletions(-)

diff --git a/scripts/mount-store b/scripts/mount-store
index 8ba2a42..d4311a1 100755
--- a/scripts/mount-store
+++ b/scripts/mount-store
@@ -34,49 +34,66 @@ images)
 esac
 
 FLAG="${DEST}/.notmounted"
-SUBDIR="${DEST}/bwlehrpool_store"
-DNBDDIR="${DEST}/stage4"
 
-storage_test () {
-	rm -f -- "${FLAG}"
-	if [ -e "${FLAG}" ]; then
-		echo "Error: File '.notmounted' exists on remote storage and could not be deleted." >&2
-		echo "Error: Make sure the share is writable." >&2
-		return 5
-	fi
-	chgrp images "${DEST}" 2>/dev/null
-	mkdir -p "${SUBDIR}"
-	if [ ! -d "${SUBDIR}" ]; then
-		echo "Error: Could not create directory $(basename "${SUBDIR}")! Storage not writable!" >&2
+prepare_dir () {
+	local owner="$1"
+	local testuser="$2"
+	local dir="$3"
+	echo "Preparing ${dir}..."
+	mkdir -p "${dir}"
+	if ! [ -d "${dir}" ]; then
+		echo "Error: Could not create directory! Storage not writable!" >&2
 		return 6
 	fi
-	echo "Applying group..."
-	find "${SUBDIR}" -type d -exec chgrp images {} \; 2>/dev/null
+	echo "Applying owner/group..."
+	find "${dir}" -type d -exec chown "$owner" {} \; 2>/dev/null
 	echo "Applying permissions..."
-	find "${SUBDIR}" -type d -exec chmod ug+rwx {} \; 2>/dev/null
+	find "${dir}" -type d -exec chmod ug+rwx {} \; 2>/dev/null
 	echo "Creating test file..."
-	local TEST="${SUBDIR}/.deleteme-$RANDOM-$RANDOM"
-	sudo -n -u dmsd touch "$TEST"
+	local TEST="${dir}/.deleteme-$RANDOM-$RANDOM-$$"
+	sudo -n -u "${testuser}" touch "$TEST"
 	local RET=$?
 	if [ -e "$TEST" ]; then
-		sudo -n -u dmsd rm -f -- "$TEST"
+		sudo -n -u "${testuser}" rm -f -- "$TEST"
 	else
 		[ "$RET" = "0" ] && RET=127
-		echo "Error: Mounted share is not writable." >&2
-		ls -al "${DEST}" "${SUBDIR}" >&2
+		echo "Error: Storage is not writable." >&2
+		ls -al "${DEST}" "${dir}" >&2
 	fi
-	echo "Applying permissions for stage4 directory..."
-	mkdir -p "${DNBDDIR}"
-	if [ ! -d "${DNBDDIR}" ]; then
-		echo "Error: Could not create directory $(basename "${DNBDDIR}")! Storage not writable!" >&2
-		return 6
-	fi
-	find "${DNBDDIR}" -type d -exec chown dnbd3:dnbd3 {} \; 2>/dev/null
-	find "${DNBDDIR}" -type d -exec chmod ug+rwx {} \; 2>/dev/null
-	# TODO: touch and rm like above...
 	return $RET
 }
 
+prepare_storage () {
+	local cifs=false
+	local type dnbd3_owner
+	case "$1" in
+		nfs*) type="remote" ;;
+		cifs) type="remote" ; cifs=true ;;
+		local) type="local" ;;
+		*) echo "Invalid storage type '$1'" ; return 1 ;;
+	esac
+	rm -f -- "${FLAG}"
+	if [ -e "${FLAG}" ]; then
+		echo "Error: File '.notmounted' exists on $type storage and could not be deleted." >&2
+		echo "Error: Make sure it is writable." >&2
+		return 5
+	fi
+	if ! prepare_dir "root:images" "dmsd" "${DEST}/bwlehrpool_store"; then
+		return 8
+	fi
+	if $cifs; then
+		adduser dnbd3 images 2> /dev/null
+		dnbd3_owner="root:images"
+	else
+		deluser dnbd3 images 2> /dev/null
+		dnbd3_owner="dnbd3:dnbd3"
+	fi
+	if ! prepare_dir "${dnbd3_owner}" "dnbd3" "${DEST}/stage4"; then
+		return 9
+	fi
+	return 0
+}
+
 enable_nfs_export () {
 	if [ -n "$TM_NOLOCALNFS" ]; then
 		disable_nfs_export
@@ -174,7 +191,7 @@ fi
 
 # Unmount and not requested to mount (local mode)
 if [[ "${SOURCE}" == "null" ]]; then
-	rm -f -- "${FLAG}"
+	prepare_storage "local"
 	systemctl --no-block start dnbd3-server.service
 	enable_nfs_export
 	echo "Success. Now using internal storage."
@@ -205,7 +222,7 @@ exec_mount () {
 	RET=$?
 	[ "$RET" -ne "0" ] && return "$RET"
 	echo "Mount succeeded, checking write permissions...."
-	storage_test
+	prepare_storage "$fstype"
 	RET=$?
 	[ "$RET" -eq "0" ] && return 0
 	umount -v "$DEST" || umount -v -f -l "$DEST"
-- 
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