control filesystems included in the generic initramfs

New "filesystems" command line/config file option is added with the ability to
control the list of kernel filesystem modules that are included in the generic
initramfs.

Signed-off-by: Dan Horák <dan@danny.cz>

dracut

@@ -37,6 +37,9 @@ Creates initial ramdisk images for preloading modules
                         exclusively include in the initramfs.
   --add-drivers [LIST]  Specify a space-separated list of kernel 
                         modules to add to the initramfs.
+  --filesystems [LIST]  Specify a space-separated list of kernel filesystem
+                        modules to exclusively include in the generic
+                        initramfs.
   -k, --kmoddir [DIR]   Specify the directory, where to look for kernel 
                         modules
   --fwdir [DIR]         Specify additional directories, where to look for 
@@ -76,6 +79,7 @@ while (($# > 0)); do
 	-a|--add) add_dracutmodules_l="$2"; shift;;
 	-d|--drivers) drivers_l="$2"; shift;;
 	--add-drivers) add_drivers_l="$2"; shift;;
+	--filesystems) filesystems_l="$2"; shift;;
 	-k|--kmoddir) drivers_dir_l="$2"; shift;;
 	--fwdir) fw_dir_l="$2"; shift;;
 	--kernel-only) kernel_only="yes"; nokernel="no";;
@@ -127,6 +131,7 @@ fi
 [[ $add_dracutmodules_l ]] && add_dracutmodules="$add_dracutmodules $add_dracutmodules_l"
 [[ $drivers_l ]] && drivers=$drivers_l
 [[ $add_drivers_l ]] && add_drivers=$add_drivers_l
+[[ $filesystems_l ]] && filesystems=$filesystems_l
 [[ $drivers_dir_l ]] && drivers_dir=$drivers_dir_l
 [[ $fw_dir_l ]] && fw_dir=$fw_dir_l
 [[ $do_strip_l ]] && do_strip=$do_strip_l
@@ -180,7 +185,7 @@ chmod 755 "$initdir"
 
 export initdir hookdirs dracutbasedir dracutmodules drivers \
     fw_dir drivers_dir debug beverbose no_kernel kernel_only \
-    add_drivers mdadmconf lvmconf
+    add_drivers mdadmconf lvmconf filesystems
 
 if [[ $kernel_only != yes ]]; then
     # Create some directory structure first

dracut.8

@@ -32,6 +32,9 @@ specify a space-separated list of kernel modules to exclusively include in the i
 .BR \-\-add-drivers " \fILIST\fR"
 specify a space-separated list of kernel modules to add to the initramfs.
 .TP
+.BR \-\-filesystems " \fILIST\fR"
+specify a space-separated list of kernel filesystem modules to exclusively include in the generic initramfs.
+.TP
 .BR \-k ", " \-\-kmoddir " \fI{DIR}\fR   
 specify the directory, where to look for kernel modules
 .TP

dracut.conf

@@ -9,6 +9,9 @@
 # additional kernel modules to the default
 #add_drivers=""
 
+# list of kernel filesystem modules to be included in the generic initramfs
+#filesystems=""
+
 # build initrd only to boot current hardware
 #hostonly="-h"
 #

modules.d/90kernel-modules/installkernel

@@ -6,16 +6,20 @@ if [[ -z $drivers ]]; then
 	 nm -uPA "$1" | egrep -q "$blockfuncs"
     }
     instmods pcmcia sd_mod $(filter_kernel_modules block_module_test) "=drivers/pcmcia" =ide "=drivers/usb/storage"
-    # if not on hostonly mode, install all known filesystems.
+    # if not on hostonly mode, install all known filesystems if the required list is not set via the filesystems variable
     if [[ $hostonly = '' ]]; then
-	instmods '=fs'
+	if [[ -z $filesystems ]]; then
+	    instmods '=fs'
+	else
+	    instmods $filesystems
+	fi
     else
 	instmods $(get_fs_type "/dev/block/$(find_root_block_device)")
     fi
     # hardcoded list of exceptions
     rm -fr ${initdir}/lib/modules/*/kernel/fs/ocfs2
 else
-  instmods $drivers
+  instmods $drivers $filesystems
 fi
 
 [[ $add_drivers ]] && instmods $add_drivers