cat <<EOF
usage: $0 SUBVOL_MOUNTPOINT...
-In git, this is not not executable because it's meant to be installed
+In git this is not not executable because it's meant to be installed
using ./install-my-scripts
-If latest subvols \$@ are not mounted, exit 1, print message, and touch
-/nocow/btrfs-stale/\$subvol
+If latest subvols \$@ are not mounted, exit 1, print message, and print
+the unstale subvol name into /nocow/btrfs-stale/\$subvol
-Either SUBVOL_MOUNTPOINT is a snapshot of the latest, or
-the latest snapshot is snapshot of SUBVOL_MOUNTPOINT.
+Fresh is opposite of stale. To be fresh, either SUBVOL_MOUNTPOINT is a
+snapshot of the latest, or the latest snapshot is snapshot of
+SUBVOL_MOUNTPOINT.
-d Enable debug output
-h|--help Print help and exit.
ret=0
for d; do
vol=${d##*/}
- dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab|head -n1)
+ # second field, non-comment line == $d
+ dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab /etc/mtab|head -n1)
d dev=$dev
- subvol_dir=$(sed -rn "s,^\s*[^#]\S*\s+$d\s.*\bsubvol=([a-zA-A/]+).*,\1,p" /etc/fstab|head -n1)
+ subvol_dir=$(sed -rn "s,^\s*[^#]\S*\s+$d\s.*\bsubvol=([a-zA-A/]+).*,\1,p" /etc/fstab /etc/mtab|head -n1)
d subvol_dir=$subvol_dir
# note, we need $dev because $d might not be mounted, and we do this loop
# because the device in fstab for the rootfs can be different.
for devx in $(btrfs fi show $dev| sed -rn 's#.*path (/\S+)$#\1#p'); do
- root_dir=$(sed -rn "s,^\s*$devx\s+(\S+).*\bsubvolid=0\b.*,\1,p" /etc/fstab|head -n1)
+ root_dir=$(sed -rn "s,^\s*$devx\s+(\S+).*\bsubvolid=[05]\b.*,\1,p" /etc/mtab|head -n1)
if [[ $root_dir ]]; then break; fi
done
- svp=$root_dir/$subvol_dir # subvolume path
- d svp=$svp
+ if [[ ! $root_dir ]]; then
+ echo "$0: error could not find root subvol mount for $dev" >&2
+ exit 1
+ fi
+ svp=$root_dir/$subvol_dir
+ d "svp=$svp # subvolume path"
snaps=($root_dir/btrbk/$subvol_dir.20*) # Assumes we are in the 21st century.
if [[ ! $snaps ]]; then
# no snapshots yet
- echo "$0: warning. no snapshots found. this is expected for a brand new volume"
+ echo "$0: warning: no snapshots found at $root_dir/btrbk/$subvol_dir.20*. this is expected for a brand new volume"
continue
fi