minor improvements

[distro-setup] / btrfsmaint

diff --git a/btrfsmaint b/btrfsmaint
index 33cae4a36280351c170155f11fc83ba8ca3b2102..d2263257d412b4da2d9e37e5c1678641e301e8f6 100755 (executable)
--- a/btrfsmaint
+++ b/btrfsmaint
@@ -46,7 +46,8 @@ usage() {
 Usage: ${0##*/} [ARGS]
 Do btrfs maintence or stop if xprintidle shows a user
 
-force  Run regardless of user idle status on all disks.
+force  Run regardless of user idle status on all disks and do scrub
+       regardless of when it was last run.
 check  Only check if an existing maintence should be cancelled due to
          nonidle user. Also, runs in a loop every 20 seconds for 10
          minutes.
@@ -102,7 +103,6 @@ main() {
   fi
 
 
-  tmp=$(mktemp)
   fnd="findmnt --types btrfs --noheading"
   for x in $($fnd --output "SOURCE" --nofsroot | sort -u); do
     mnt=$($fnd --output "TARGET" --first-only --source $x)
@@ -113,10 +113,22 @@ main() {
     # Only run for $check, since it runs in parallel to non-check, avoid
     # race condition.
     if $check; then
-      if ! btrfs dev stats -c $mnt >$tmp; then
-        if diff -q $mnt/btrfs-dev-stats $tmp; then
-          diff -u $mnt/btrfs-dev-stats $tmp | mail -s "$HOSTNAME: error: btrfs dev stats -c $mnt" root@localhost
-          cat $tmp >$mnt/btrfs-dev-stats
+      tmp=$(mktemp)
+      # if mnt is /, avoid making a buggy looking path
+      stats_path=${mnt%/}/btrfs-dev-stats
+      if [[ ! -e $stats_path ]]; then
+        btrfs dev stats -c $mnt >$stats_path ||: # populate initial reading
+      elif ! btrfs dev stats -c $mnt >$tmp; then
+        if ! diff -q $stats_path $tmp; then
+              exim -t <<EOF
+From: root@$HOSTNAME.b8.nz
+To: alerts@iankelling.org
+Subject: btrfsmaintstop: btrfs dev stats -c $mnt
+
+$(diff -u $stats_path $tmp ||:)
+EOF
+          mv $stats_path $stats_path.1
+          cat $tmp >$stats_path
         fi
       fi
       rm -f $tmp
@@ -164,7 +176,7 @@ main() {
           sed -rn 's/^\s*scrub started at (.*) and finished.*/\1/p'
           )
     fi
-    if [[ $date ]]; then
+    if ! $force && [[ $date ]]; then
       if $dryrun; then
         echo "$0: last scrub finish for $mnt: $date"
       fi
@@ -179,8 +191,8 @@ main() {
         continue
       fi
     fi
-    # -c 2 -n 4 is from btrfsmaintenance, does ionice
-    e btrfs scrub start -Bd -c 2 -n 4 $mnt
+    # btrfsmaintenance does -c 2 -n 4, but I want lowest pri.
+    e btrfs scrub start -Bd -c 3 $mnt
 
     # We normally only do one disk since this is meant to be run while I sleep
     # and if we try to do all disks, we invariably end up doing a scrub still