Add script to send mail in case btrfs issues were detected

btrfs-issuemail.service

@@ -0,0 +1,7 @@
+[Unit]
+Description=Check for btrfs issues and send an email if any were found
+Documentation=man:btrfs
+
+[Service]
+Type=simple
+ExecStart=/usr/share/btrfsmaintenance/btrfs-issuemail.sh

btrfs-issuemail.sh

@@ -0,0 +1,82 @@
+#!/bin/bash
+#
+# Copyright (c) 2022 Matthias Klumpp <[email protected]>
+
+umask 022
+PATH=/sbin:/bin:/usr/sbin:/usr/bin
+export PATH
+
+if [ -f /etc/sysconfig/btrfsmaintenance ] ; then
+    . /etc/sysconfig/btrfsmaintenance
+fi
+
+if [ -f /etc/default/btrfsmaintenance ] ; then
+    . /etc/default/btrfsmaintenance
+fi
+
+. $(dirname $(realpath "$0"))/btrfsmaintenance-functions
+
+if [ -z "$BTRFS_MAILADDR" ]
+then
+      # no email set, nothing to do for us
+      exit 0
+fi
+
+if ! command -v sendmail &> /dev/null
+then
+	echo "Failed to find sendmail, can not send emails about issues!" >/dev/stderr
+	exit 1
+fi
+
+ISSUE_MAIL_SENT_FILE="/run/btrfs-issue-mail-sent"
+if [ -f "$ISSUE_MAIL_SENT_FILE" ]; then
+	if [[ $(find "$ISSUE_MAIL_SENT_FILE" -mtime +1 -print) ]]; then
+		# delete issue sent file if it is older than a day, so
+		# we will send all notifications again
+		rm $ISSUE_MAIL_SENT_FILE
+	fi
+fi
+
+BTRFS_STATS_MOUNTPOINTS=$(expand_auto_mountpoint "auto")
+OIFS="$IFS"
+IFS=:
+for MM in $BTRFS_STATS_MOUNTPOINTS; do
+	if ! is_btrfs "$MM"; then
+		echo "Path $MM is not btrfs, skipping"
+		continue
+	fi
+	DEVSTATS=$(btrfs device stats --check $MM 2>&1)
+	if [ $? -ne 0 ]; then
+
+		if [ -f "$ISSUE_MAIL_SENT_FILE" ]; then
+			# check if we already sent an email
+			if grep -Fxq "$MM" "$ISSUE_MAIL_SENT_FILE"; then
+				# we've already mailed a report for issues on this
+				# mountpoint today, don't send another one just yet
+				continue
+			fi
+		fi
+
+		sendmail -t <<EOF
+To: $BTRFS_MAILADDR
+Subject: Btrfs device issue on $MM @ $HOSTNAME
+
+This is an automatically generated mail message from btrfs-issuemail
+running on $HOSTNAME
+
+An issue has been detected on the btrfs device mounted as $MM.
+
+Faithfully yours, etc.
+
+P.S. The 'btrfs device stats' output is:
+$DEVSTATS
+
+Filesystem usage:
+$(btrfs fi df $MM 2>&1)
+EOF
+		# set flag that we already sent a mail about this today
+		echo "$MM" >> $ISSUE_MAIL_SENT_FILE
+        fi
+done
+
+exit 0

btrfs-issuemail.timer

@@ -0,0 +1,10 @@
+[Unit]
+Description=Check for btrfs issues and send mail if any were found
+Documentation=man:btrfs
+
+[Timer]
+OnCalendar=hourly
+Persistent=true
+
+[Install]
+WantedBy=timers.target

sysconfig.btrfsmaintenance

@@ -152,3 +152,13 @@ BTRFS_TRIM_MOUNTPOINTS="/"
 # the timer for these tasks(s) elapsed while the system was suspended
 # or powered off.
 BTRFS_ALLOW_CONCURRENCY="false"
+
+## Path:	System/File systems/btrfs
+## Description:	Mail address to send issue reports to
+## Type: 	string
+## Default:	""
+#
+# If this is set to an email address or an username like "root", btrfs device stats
+# data will be checked every hour and an email will be sent to the given address
+# if any issues(like data corruption or read issues) were found.
+BTRFS_MAILADDR=""