+
+# Get the block size of the filesystem.
+get_block_size() {
+ local facet=$1
+ local device=$2
+ local size
+
+ size=$(do_facet $facet "$DUMPE2FS -h $device 2>&1" |
+ awk '/^Block size:/ {print $3}')
+ echo $size
+}
+
+# Check whether the "large_xattr" feature is enabled or not.
+large_xattr_enabled() {
+ local mds_dev=$(mdsdevname ${SINGLEMDS//mds/})
+
+ do_facet $SINGLEMDS "$DUMPE2FS -h $mds_dev 2>&1 | grep -q large_xattr"
+ return ${PIPESTATUS[0]}
+}
+
+# Get the maximum xattr size supported by the filesystem.
+max_xattr_size() {
+ local size
+
+ if large_xattr_enabled; then
+ # include/linux/limits.h: #define XATTR_SIZE_MAX 65536
+ size=65536
+ else
+ local mds_dev=$(mdsdevname ${SINGLEMDS//mds/})
+ local block_size=$(get_block_size $SINGLEMDS $mds_dev)
+
+ # maximum xattr size = size of block - size of header -
+ # size of 1 entry - 4 null bytes
+ size=$((block_size - 32 - 32 - 4))
+ fi
+
+ echo $size
+}
+
+# Dump the value of the named xattr from a file.
+get_xattr_value() {
+ local xattr_name=$1
+ local file=$2
+
+ echo "$(getfattr -n $xattr_name --absolute-names --only-values $file)"
+}
+
+# Generate a string with size of $size bytes.
+generate_string() {
+ local size=${1:-1024} # in bytes
+
+ echo "$(head -c $size < /dev/zero | tr '\0' y)"
+}
+
+reformat_external_journal() {
+ if [ ! -z ${EJOURNAL} ]; then
+ local rcmd="do_facet ${SINGLEMDS}"
+
+ echo "reformat external journal on ${SINGLEMDS}:${EJOURNAL}"
+ ${rcmd} mke2fs -O journal_dev ${EJOURNAL} || return 1
+ fi
+}
+
+# MDT file-level backup/restore
+mds_backup_restore() {
+ local devname=$(mdsdevname ${SINGLEMDS//mds/})
+ local mntpt=$(facet_mntpt brpt)
+ local rcmd="do_facet ${SINGLEMDS}"
+ local metaea=${TMP}/backup_restore.ea
+ local metadata=${TMP}/backup_restore.tgz
+ local opts=${MDS_MOUNT_OPTS}
+
+ if ! ${rcmd} test -b ${devname}; then
+ opts=$(csa_add "$opts" -o loop)
+ fi
+
+ echo "file-level backup/restore on ${SINGLEMDS}:${devname}"
+
+ # step 1: build mount point
+ ${rcmd} mkdir -p $mntpt
+ # step 2: cleanup old backup
+ ${rcmd} rm -f $metaea $metadata
+ # step 3: mount dev
+ ${rcmd} mount -t ldiskfs $opts $devname $mntpt || return 1
+ # step 4: backup metaea
+ echo "backup EA"
+ ${rcmd} "cd $mntpt && getfattr -R -d -m '.*' -P . > $metaea && cd -" ||
+ return 2
+ # step 5: backup metadata
+ echo "backup data"
+ ${rcmd} tar zcf $metadata -C $mntpt/ . > /dev/null 2>&1 || return 3
+ # step 6: umount
+ ${rcmd} umount -d $mntpt || return 4
+ # step 7: reformat external journal if needed
+ reformat_external_journal || return 5
+ # step 8: reformat dev
+ echo "reformat new device"
+ add ${SINGLEMDS} $(mkfs_opts ${SINGLEMDS}) --backfstype ldiskfs \
+ --reformat $devname > /dev/null || return 6
+ # step 9: mount dev
+ ${rcmd} mount -t ldiskfs $opts $devname $mntpt || return 7
+ # step 10: restore metadata
+ echo "restore data"
+ ${rcmd} tar zxfp $metadata -C $mntpt > /dev/null 2>&1 || return 8
+ # step 11: restore metaea
+ echo "restore EA"
+ ${rcmd} "cd $mntpt && setfattr --restore=$metaea && cd - " || return 9
+ # step 12: remove recovery logs
+ echo "remove recovery logs"
+ ${rcmd} rm -fv $mntpt/OBJECTS/* $mntpt/CATALOGS
+ # step 13: umount dev
+ ${rcmd} umount -d $mntpt || return 10
+ # step 14: cleanup tmp backup
+ ${rcmd} rm -f $metaea $metadata
+}
+
+# remove OI files
+mds_remove_ois() {
+ local devname=$(mdsdevname ${SINGLEMDS//mds/})
+ local mntpt=$(facet_mntpt brpt)
+ local rcmd="do_facet ${SINGLEMDS}"
+ local idx=$1
+ local opts=${MDS_MOUNT_OPTS}
+
+ if ! ${rcmd} test -b ${devname}; then
+ opts=$(csa_add "$opts" -o loop)
+ fi
+
+ echo "remove OI files: idx=${idx}"
+
+ # step 1: build mount point
+ ${rcmd} mkdir -p $mntpt
+ # step 2: mount dev
+ ${rcmd} mount -t ldiskfs $opts $devname $mntpt || return 1
+ if [ -z $idx ]; then
+ # step 3: remove all OI files
+ ${rcmd} rm -fv $mntpt/oi.16*
+ elif [ $idx -lt 2 ]; then
+ ${rcmd} rm -fv $mntpt/oi.16.${idx}
+ else
+ local i
+
+ # others, rm oi.16.[idx, idx * idx, idx ** ...]
+ for ((i=${idx}; i<64; i=$((i * idx)))); do
+ ${rcmd} rm -fv $mntpt/oi.16.${i}
+ done
+ fi
+ # step 4: umount
+ ${rcmd} umount -d $mntpt || return 2
+ # OI files will be recreated when mounted as lustre next time.
+}