X-Git-Url: https://iankelling.org/git/?a=blobdiff_plain;f=check-subvol-stale;h=dcc0535e6df227cc3b5b03f56a8a543b8df4eeb3;hb=94fb80d967f107cbde4a3920dededbb406b2443b;hp=bdb47492ef07b132914b21ec6773014675dca38f;hpb=eb9b839bb5a91c60cc4f6eb9d7e38ffbf73f0e90;p=distro-setup

diff --git a/check-subvol-stale b/check-subvol-stale
index bdb4749..dcc0535 100644
--- a/check-subvol-stale
+++ b/check-subvol-stale
@@ -13,16 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# usage: $0 SUBVOL_MOUNTPOINT...
-#
-# 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
-#
-# Either SUBVOL_MOUNTPOINT is a snapshot of the latest, or
-# the latest snapshot is snapshot of SUBVOL_MOUNTPOINT.
 
 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
 
@@ -31,6 +21,42 @@ trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
 
 shopt -s nullglob
 
+usage() {
+  cat <<EOF
+usage: $0 SUBVOL_MOUNTPOINT...
+
+In git this is not not executable because it's meant to be installed
+using ./install-my-scripts
+
+If latest subvols \$@ are not mounted, print a message, and print
+the unstale subvol name into /nocow/btrfs-stale/\$subvol
+
+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.
+
+Note: Uses GNU getopt options parsing style
+EOF
+  exit $1
+}
+
+##### begin command line parsing ########
+
+debug=false # default
+temp=$(getopt -l help,d hd "$@") || usage 1
+eval set -- "$temp"
+while true; do
+  case $1 in
+    -d) debug=true; shift ;;
+    -h|--help) usage ;;
+    --) shift; break ;;
+    *) echo "$0: Internal error! unexpected args: $*" ; exit 1 ;;
+  esac
+done
+
 if [[ ! $@ ]]; then
     echo "$0: error: expected mountpoint argument"
 fi
@@ -41,45 +67,58 @@ stale-file() {
     if $stale; then
         mkdir -p $stale_dir
         printf "%s\n" $freshest_snap > $stale_file
-        ret=1
     else
         rm -f $stale_file
     fi
 
 }
+d() {
+  if $debug; then
+    printf "%s\n" "$*"
+    fi
+}
 
-ret=0
 for d; do
     vol=${d##*/}
-    dev=$(sed -rn "s,^\s*([^#]\S*)\s+$d\s.*,\1,p" /etc/fstab|head -n1)
-    subvol_dir=$(sed -rn "s,^\s*[^#]\S*\s+$d\s.*\bsubvol=([a-zA-A/]+).*,\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 /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
+    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
 
     # get info on last received sub
-    last_received_gen=0
+    last_received_cgen=0
     for f in ${snaps[@]}; do
         show="$(btrfs sub show $f)"
         if echo "$show" | grep -E "Received UUID:\s+[[:alnum:]]" &>/dev/null; then
             cgen=$(echo "$show" | sed -rn 's,^\s*Gen at creation:\s+([0-9]+).*,\1,p')
-            if [[ $cgen -gt $last_received_gen ]]; then
+            if [[ $cgen -gt $last_received_cgen ]]; then
                 last_received_cgen=$cgen
                 last_received=$f
             fi
         fi
     done
+    d last_received_cgen=$cgen
+    d last_received=$f
 
     # Get last_snap by date.
     # when a btrbk bugfix makes it into the distro,
@@ -93,9 +132,8 @@ for d; do
              )
     if [[ ! $last_snap ]]; then
         # should not happen.
-        echo "$0: error: could not find latest snapshot for $svp among ${snaps[*]}"
-        ret=1
-        continue
+        echo "$0: error: could not find latest snapshot for $svp among ${snaps[*]}" >&2
+        exit 1
     fi
 
     if [[ ! -e $svp ]]; then
@@ -111,6 +149,7 @@ for d; do
     # if there is a last_received, we can assume stale or fresh if we are newer/older
     if [[ $last_received ]]; then
         svp_cgen=$(btrfs sub show $svp | sed -rn 's,^\s*Gen at creation:\s+([0-9]+).*,\1,p')
+        d svp_cgen=$svp_cgen
         if [[ $svp_cgen -ge $last_received_cgen ]]; then
             stale=false
         else
@@ -139,6 +178,4 @@ for d; do
     fi
 
     stale-file
-
 done
-exit $ret