- if [[ -e /a/opt/btrfs-snapshots-diff/btrfs-snapshots-diff.py ]]; then
- source /a/bin/distro-functions/src/package-manager-abstractions
- #pi python-jmespath # dependency of btrfs-snapshots-diff
- # todo: need python3 port of btrfs-snapshots-diff, py2 no exist on nabia
- parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
- bsubs=(btrbk/$vol.*)
- bsub=
- # go in reverse order as its more likely to be at the end
- for ((i=${#bsubs[@]}-1; i>=0; i--)); do
- if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
- bsub=${bsubs[i]}
- break
- fi
- done
- if [[ $bsub ]]; then
- tmp=$(mktemp)
- # in testing, same subvol is 136 bytes. allow some overhead. 32 happens sometimes under systemd.
- # $ errno 32
- # EPIPE 32 Broken pipe
- btrfs send --no-data -p $bsub $leaf | head -c 1000 > $tmp || [[ $? == 141 || ${PIPESTATUS[0]} == 32 ]]
- if (( $(stat -c%s $tmp) < 1000)); then
- # example output for an empty diff:
- # Found a valid Btrfs stream header, version 1
- # o.leaf.2019-05-15T14:00:50-0400;snapshot: uuid=ba045ea30737dd449003f1ee40ec12d0, ctrasid=109533, clone_uuid=3c7e3544e486834aa71d89e5b8f30056, clone_ctransid=109533
- lines=$(/a/opt/btrfs-snapshots-diff/btrfs-snapshots-diff.py -s -f $tmp | \
- grep -vxF "Found a valid Btrfs stream header, version 1" | \
- grep -cv "^[^;]*;snapshot: ") ||:
- if [[ $lines == 0 ]]; then
- # rotate in case we find a bug, weve got 2 old ones
- tmpleaf=($vol.tmpleaf2.*)
- if (( ${#tmpleaf[@]} )); then
- x btrfs sub del ${tmpleaf[@]}
- fi
- tmpleaf=($vol.tmpleaf1.*)
- if (( ${#tmpleaf[@]} )); then
- x mv ${tmpleaf[0]} $vol.tmpleaf2.${tmpleaf[0]#$vol.tmpleaf1.}
- fi
- echo suspected identical: $bsub $leaf
- x mv $leaf $vol.tmpleaf1.${leaf#$vol.leaf.}
- fi
- fi
+ parentid=$(btrfs sub show $leaf | awk '$1 == "Parent" && $2 == "UUID:" {print $3}')
+ bsubs=(btrbk/$vol.*)
+ bsub= # base subvolume
+ # go in reverse order as its more likely to be at the end
+ for ((i=${#bsubs[@]}-1; i>=0; i--)); do
+ if [[ $parentid == $(btrfs sub show ${bsubs[i]} | awk '$1 == "UUID:" {print $2}') ]]; then
+ bsub=${bsubs[i]}
+ break
+ fi
+ done
+ if [[ $bsub ]]; then
+ # in testing, same subvol is 136 bytes. allow some overhead. 32 happens sometimes under systemd.
+ # $ errno 32
+ # EPIPE 32 Broken pipe
+ lines=$(btrfs send --no-data -p $bsub $leaf | btrfs receive --dump | head -n 100 | wc -l || [[ $? == 141 || ${PIPESTATUS[0]} == 32 ]])
+ if [[ $lines == 0 ]]; then
+ # example output of no differences:
+ # snapshot ./qrtest uuid=c41ff6b7-0527-f34d-95ac-190eecf54ff5 transid=2239 parent_uuid=64949e1b-4a3e-3945-9a8e-cd7b7c15d7d6 parent_transid=2239
+ echo suspected identical: $bsub $leaf
+ x btrfs sub del $leaf