1 files changed, 72 insertions, 1 deletions
diff --git a/fs/ext2/genext2fs.sh b/fs/ext2/genext2fs.sh
index 7a518aea7..c2049f56c 100755
--- a/fs/ext2/genext2fs.sh
+++ b/fs/ext2/genext2fs.sh
@@ -1,10 +1,13 @@
 #!/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}