fix mistake from recent commit

[distro-setup] / check-subvol-stale

diff --git a/check-subvol-stale b/check-subvol-stale
index c585cea0169c2fb9bde14224380f252100f5067f..dcc0535e6df227cc3b5b03f56a8a543b8df4eeb3 100644 (file)
--- a/check-subvol-stale
+++ b/check-subvol-stale
@@ -25,14 +25,15 @@ usage() {
   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, print a 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.
@@ -66,7 +67,6 @@ stale-file() {
     if $stale; then
         mkdir -p $stale_dir
         printf "%s\n" $freshest_snap > $stale_file
-        ret=1
     else
         rm -f $stale_file
     fi
@@ -78,26 +78,30 @@ d() {
     fi
 }
 
-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
 
@@ -128,9 +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
@@ -175,6 +178,4 @@ for d; do
     fi
 
     stale-file
-
 done
-exit $ret