Commit 69036c20 authored by Yann E. MORIN's avatar Yann E. MORIN Committed by Peter Korsgaard
Browse files

fs/ext2: add ability to build ext3/4 too 



Use the host-e2fsprogs to tune2fs the generated rootfs.ext2 image,
and upgrade it to either one of ext2, ext3 or ext4.

Since calling tune2fs may require running e2fsck (tune2fs will warn
to do so when certain FS options are changed), we systematically call
e2fsck. This makes the code path simpler, and as a side-effect checks
that genext2fs did not generate garbage.

In turn, e2fsck will unconditionally add a UUID to the filesystem,
which is bad for reproducibility, so we call tune2fs again to remove
the UUID. This does not require checking the filesystem.

To ensure compatibility of Buildroot's .config, leave ext2 as the
default. Boards' .config can override this at will.

Signed-off-by: default avatar"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Peter Korsgaard <jacmet@uclibc.org>
Signed-off-by: default avatarPeter Korsgaard <jacmet@sunsite.dk>
parent 5fbef614

fs/ext2/Config.in

+29 −7
Original line number Diff line number Diff line 
config BR2_TARGET_ROOTFS_EXT2

	bool "ext2 root filesystem"

	bool "ext2/3/4 root filesystem"

	select BR2_PACKAGE_HOST_E2FSPROGS

	help

	  Build an ext2 root filesystem

	  Build an ext2/3/4 root filesystem



if BR2_TARGET_ROOTFS_EXT2



choice

	bool "ext2/3/4 variant"

	default BR2_TARGET_ROOTFS_EXT2_2



config BR2_TARGET_ROOTFS_EXT2_2

	bool "ext2"



config BR2_TARGET_ROOTFS_EXT2_3

	bool "ext3"



config BR2_TARGET_ROOTFS_EXT2_4

	bool "ext4"



endchoice



config BR2_TARGET_ROOTFS_EXT2_GEN

	int

	default 2 if BR2_TARGET_ROOTFS_EXT2_2

	default 3 if BR2_TARGET_ROOTFS_EXT2_3

	default 4 if BR2_TARGET_ROOTFS_EXT2_4



config BR2_TARGET_ROOTFS_EXT2_BLOCKS

	int "size in blocks (leave at 0 for auto calculation)"

	default 0
@@ -21,27 +43,27 @@ choice 
	prompt "Compression method"

	default BR2_TARGET_ROOTFS_EXT2_NONE

	help

	  Select compressor for ext2 filesystem of the root filesystem

	  Select compressor for ext2/3/4 filesystem of the root filesystem



config BR2_TARGET_ROOTFS_EXT2_NONE

	bool "no compression"

	help

	  Do not compress the ext2 filesystem.

	  Do not compress the ext2/3/4 filesystem.



config BR2_TARGET_ROOTFS_EXT2_GZIP

	bool "gzip"

	help

	  Do compress the ext2 filesystem with gzip.

	  Do compress the ext2/3/4 filesystem with gzip.



config BR2_TARGET_ROOTFS_EXT2_BZIP2

	bool "bzip2"

	help

	  Do compress the ext2 filesystem with bzip2.

	  Do compress the ext2/3/4 filesystem with bzip2.



config BR2_TARGET_ROOTFS_EXT2_LZMA

	bool "lzma"

	help

	  Do compress the ext2 filesystem with lzma.

	  Do compress the ext2/3/4 filesystem with lzma.



endchoice

fs/ext2/ext2.mk

+4 −2
Original line number Diff line number Diff line
@@ -18,10 +18,12 @@ ifneq ($(strip $(BR2_TARGET_ROOTFS_EXT2_RESBLKS)),0) 
EXT2_OPTS += -m $(BR2_TARGET_ROOTFS_EXT2_RESBLKS)

endif



ROOTFS_EXT2_DEPENDENCIES = host-genext2fs

ROOTFS_EXT2_DEPENDENCIES = host-genext2fs host-e2fsprogs



EXT2_ENV = GEN=$(BR2_TARGET_ROOTFS_EXT2_GEN)



define ROOTFS_EXT2_CMD

	PATH=$(TARGET_PATH) fs/ext2/genext2fs.sh -d $(TARGET_DIR) $(EXT2_OPTS) $@

	PATH=$(TARGET_PATH) $(EXT2_ENV) fs/ext2/genext2fs.sh -d $(TARGET_DIR) $(EXT2_OPTS) $@

endef



$(eval $(call ROOTFS_TARGET,ext2))

fs/ext2/genext2fs.sh

+72 −1
Original line number Diff line number Diff line 
#!/bin/sh

# genext2fs wrapper calculating needed blocks/inodes values if not specified

set -e



export LC_ALL=C



CALC_BLOCKS=1

CALC_INODES=1

EXT_OPTS=

EXT_OPTS_O=



while getopts x:d:D:b:i:N:m:g:e:zfqUPhVv f

do
@@ -14,6 +17,7 @@ do 
	d) TARGET_DIR=$OPTARG ;;

    esac

done

eval IMG="\"\${${OPTIND}}\""



# calculate needed inodes

if [ $CALC_INODES -eq 1 ];
@@ -30,7 +34,74 @@ then 
    # we scale inodes / blocks with 10% to compensate for bitmaps size + slack

    BLOCKS=$(du -s -c -k $TARGET_DIR | grep total | sed -e "s/total//")

    BLOCKS=$(expr 500 + \( $BLOCKS + $INODES / 8 \) \* 11 / 10)

    # we add 1081 blocks (a bit more than 1 MiB, assuming 1KiB blocks) for

    # the journal if ext3/4

    # Note: I came to 1081 blocks after trial-and-error checks. With 1080 or

    # less additional blocks, and tune2fs would refuse to add the journal;

    # with 1081 additional blocks or above, tune2fs wil happily add a journal.

    # YMMV.

    if [ ${GEN} -ge 3 ]; then

        BLOCKS=$(expr 1081 + $BLOCKS )

    fi

    set -- $@ -b $BLOCKS

fi



exec genext2fs $@
 
e2tunefsck() {

    # Upgrade the file system

    if [ $# -ne 0 ]; then

        tune2fs "$@" "${IMG}"

    fi



    # After changing filesystem options, running fsck is required

    # (see: man tune2fs). Running e2fsck in other cases will ensure

    # coherency of the filesystem, although it is not required.

    # 'e2fsck -pDf' means:

    #  - automatically repair

    #  - optimise and check for duplicate entries

    #  - force checking

    # Sending output to oblivion, as e2fsck can be *very* verbose,

    # especially with filesystems generated by genext2fs.

    # Exit codes 1 & 2 are OK, it means fs errors were successfully

    # corrected, hence our little trick with $ret.

    ret=0

    e2fsck -pDf "${IMG}" >/dev/null || ret=$?

    case ${ret} in

       0|1|2) ;;

       *)   exit ${ret};;

    esac

    printf "\ne2fsck was successfully run on '%s' (ext%d)\n\n"  \

           "${IMG##*/}" "${GEN}"



    # e2fsck will force a *random* UUID, which is bad

    # for reproducibility, so we do not want it

    tune2fs -U clear "${IMG}"

}



# Check we know what generation to generate

case "${GEN}" in

    2|3|4)

	;;

    *)

	printf "%s: unknown ext generation to generate\n" "${0##*/}" >&2

	exit 1

	;;

esac



# Add a journal for ext3 and above

if [ ${GEN} -ge 3 ]; then

    EXT_OPTS="${EXT_OPTS} -j -J size=1"

fi



# Add ext4 specific features

if [ ${GEN} -ge 4 ]; then

    EXT_OPTS_O="${EXT_OPTS_O},extents,uninit_bg,dir_index"

fi



# Add our -O options (there will be at most one leading comma, remove it)

if [ -n "${EXT_OPTS_O}" ]; then

    EXT_OPTS="${EXT_OPTS} -O ${EXT_OPTS_O#,}"

fi



# Generate and upgrade the filesystem

genext2fs "$@"

e2tunefsck ${EXT_OPTS}

package/e2fsprogs/Config.in.host

+1 −1
Original line number Diff line number Diff line 
config BR2_PACKAGE_HOST_E2FSPROGS

	bool "host e2fsprogs"

	help

	  The EXT2 file system utilities.

	  The EXT2/3/4 file system utilities.

	  

	  http://e2fsprogs.sf.net