diff --git a/scripts/qemu-guest-agent/fsfreeze-hook b/scripts/qemu-guest-agent/fsfreeze-hook index 6e2d7588af..21eb5c5145 100755 --- a/scripts/qemu-guest-agent/fsfreeze-hook +++ b/scripts/qemu-guest-agent/fsfreeze-hook @@ -47,8 +47,23 @@ for file in "$FSFREEZE_D"/* ; do "$file" "$@" >>"$LOGFILE" 2>&1 STATUS=$? else - "$file" "$@" 2>&1 | logger -t qemu-ga-freeze-hook - STATUS=${PIPESTATUS[0]} + # We want to pipe the output of $file through 'logger' and also + # capture its exit status. Since we are a POSIX script we can't + # use PIPESTATUS, so instead this is a trick borrowed from + # https://unix.stackexchange.com/questions/14270/get-exit-status-of-process-thats-piped-to-another/70675#70675 + # which uses command-groups and redirection to get the exit status. + # This is equivalent to + # "$file" "$@" 2>&1 | logger -t qemu-ga-freeze-hook + # plus setting the exit status of the pipe to the exit + # status of the first command rather than the last one. + { { { { + "$file" "$@" 2>&1 3>&- 4>&- + echo $? >&3 + } | logger -t qemu-ga-freeze-hook >&4 + } 3>&1 + } | { read -r xs ; exit "$xs"; } + } 4>&1 + STATUS=$? fi if [ "$STATUS" -ne 0 ]; then