dracut-lib.sh: Add det_fs() and wrap_fsck()

Both functions will be used by rootfs-block and fstab-sys modules.

Both are based on code present in mount-root.sh, though few changes are
present.

det_fs:

will try to determine filesystem type for supplied device, even if it's
not auto. If fs cannot be detected, or if the detected one differs from
the supplied one - a warning is issued (so user can fix its stuff later)

wrap_fsck:

will call fsck for specific device with optionally additional
fsckoptions. The function returns fsck return value.

Signed-off-by: Michal Soltys <soltys@ziu.info>

modules.d/99base/dracut-lib.sh

@@ -515,3 +515,50 @@ foreach_uuid_until() (
 
     return 1
 )
+
+# Wrap fsck call for device _dev with additional fsck options _fsckopts return
+# fsck's return code
+wrap_fsck() {
+    local _ret _out _dev="$1" _fsckopts="$2"
+
+    info "Checking filesystem."
+    info fsck -T $_fsckopts "$_dev"
+    _out=$(fsck -T $_fsckopts "$_dev") ; _ret=$?
+
+    # A return of 4 or higher means there were serious problems.
+    if [ $_ret -gt 3 ]; then
+        echo $_out|vwarn
+        warn "fsck returned with error code $_ret"
+        warn "*** An error occurred during the file system check."
+        warn "*** Dropping you to a shell; the system will try"
+        warn "*** to mount the filesystem, when you leave the shell."
+        emergency_shell -n "(Repair filesystem)"
+    else
+        echo $_out|vinfo
+        [ $_ret -gt 0 ] && warn "fsck returned with $_ret"
+    fi
+
+    return $_ret
+}
+
+# Verify supplied filesystem type, fix if it's invalid, warn user if
+# appropriate
+det_fs() {
+    local _dev="$1" _fs="${2:-auto}" _inf="$3" _orig
+
+    _orig="$_fs"
+    _fs=$(udevadm info --query=env --name="$_dev" | \
+    while read line; do
+        if str_starts $line "ID_FS_TYPE="; then
+            echo ${line#ID_FS_TYPE=}
+            break
+        fi
+    done)
+    _fs=${_fs:-auto}
+    if [ "$_fs" = "auto" ]; then
+        warn "Cannon detect filesystem type for device $_dev"
+    elif [ "$_orig" != "auto" -a "$_fs" != "$_orig" ]; then
+        warn "$_inf: detected filesystem '$_fs' instead of '$_orig' for device: $_dev"
+    fi
+    echo "$_fs"
+}