The fsfreeze-hook script starts with #!/bin/sh, but it uses
several bash-specific constructs, resulting in misbehaviour
on guest systems where /bin/sh is some other POSIX shell.

Fix the simple ones reported by shellcheck:

In scripts/qemu-guest-agent/fsfreeze-hook line 27:
touch "$LOGFILE" &>/dev/null || USE_SYSLOG=1
                 ^---------^ SC3020 (warning): In POSIX sh, &> is undefined.

In scripts/qemu-guest-agent/fsfreeze-hook line 31:
    local message="$1"
    ^-----------^ SC3043 (warning): In POSIX sh, 'local' is undefined.

In scripts/qemu-guest-agent/fsfreeze-hook line 46:
    log_message "Executing $file $@"
                                 ^-- SC2145 (error): Argument mixes string and array. Use * or separate argument.

In scripts/qemu-guest-agent/fsfreeze-hook line 55:
    if [ $STATUS -ne 0 ]; then
         ^-----^ SC2086 (info): Double quote to prevent globbing and word splitting.

There is also a use of PIPESTATUS that is more complex to fix;
that will be dealt with in a separate commit.

Cc: qemu-stable@nongnu.org
Fixes: 85978dfb6b1c133 ("qemu-ga: Optimize freeze-hook script logic of logging error")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 scripts/qemu-guest-agent/fsfreeze-hook | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/scripts/qemu-guest-agent/fsfreeze-hook b/scripts/qemu-guest-agent/fsfreeze-hook
index 5b915af017..6e2d7588af 100755
--- a/scripts/qemu-guest-agent/fsfreeze-hook
+++ b/scripts/qemu-guest-agent/fsfreeze-hook
@@ -24,15 +24,14 @@ USE_SYSLOG=0
 # if log file is not writable, fallback to syslog
 [ ! -w "$LOGFILE" ] && USE_SYSLOG=1
 # try to update log file and fallback to syslog if it fails
-touch "$LOGFILE" &>/dev/null || USE_SYSLOG=1
+touch "$LOGFILE" >/dev/null 2>&1 || USE_SYSLOG=1
 
 # Ensure the log file is writable, fallback to syslog if not
 log_message() {
-    local message="$1"
     if [ "$USE_SYSLOG" -eq 0 ]; then
-        printf "%s: %s\n" "$(date)" "$message" >>"$LOGFILE"
+        printf "%s: %s\n" "$(date)" "$1" >>"$LOGFILE"
     else
-        logger -t qemu-ga-freeze-hook "$message"
+        logger -t qemu-ga-freeze-hook "$1"
     fi
 }
 
@@ -43,7 +42,7 @@ for file in "$FSFREEZE_D"/* ; do
     is_ignored_file "$file" && continue
     [ -x "$file" ] || continue
 
-    log_message "Executing $file $@"
+    log_message "Executing $file $*"
     if [ "$USE_SYSLOG" -eq 0 ]; then
         "$file" "$@" >>"$LOGFILE" 2>&1
         STATUS=$?
@@ -52,7 +51,7 @@ for file in "$FSFREEZE_D"/* ; do
         STATUS=${PIPESTATUS[0]}
     fi
 
-    if [ $STATUS -ne 0 ]; then
+    if [ "$STATUS" -ne 0 ]; then
         log_message "Error: $file finished with status=$STATUS"
     else
         log_message "$file finished successfully"
-- 
2.43.0

Reviewed-by: Kostiantyn Kostiuk <kkostiuk@redhat.com>

On Tue, Mar 17, 2026 at 11:48 AM Peter Maydell <peter.maydell@linaro.org>
wrote:

> The fsfreeze-hook script starts with #!/bin/sh, but it uses
> several bash-specific constructs, resulting in misbehaviour
> on guest systems where /bin/sh is some other POSIX shell.
>
> Fix the simple ones reported by shellcheck:
>
> In scripts/qemu-guest-agent/fsfreeze-hook line 27:
> touch "$LOGFILE" &>/dev/null || USE_SYSLOG=1
>                  ^---------^ SC3020 (warning): In POSIX sh, &> is
> undefined.
>
> In scripts/qemu-guest-agent/fsfreeze-hook line 31:
>     local message="$1"
>     ^-----------^ SC3043 (warning): In POSIX sh, 'local' is undefined.
>
> In scripts/qemu-guest-agent/fsfreeze-hook line 46:
>     log_message "Executing $file $@"
>                                  ^-- SC2145 (error): Argument mixes string
> and array. Use * or separate argument.
>
> In scripts/qemu-guest-agent/fsfreeze-hook line 55:
>     if [ $STATUS -ne 0 ]; then
>          ^-----^ SC2086 (info): Double quote to prevent globbing and word
> splitting.
>
> There is also a use of PIPESTATUS that is more complex to fix;
> that will be dealt with in a separate commit.
>
> Cc: qemu-stable@nongnu.org
> Fixes: 85978dfb6b1c133 ("qemu-ga: Optimize freeze-hook script logic of
> logging error")
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  scripts/qemu-guest-agent/fsfreeze-hook | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/scripts/qemu-guest-agent/fsfreeze-hook
> b/scripts/qemu-guest-agent/fsfreeze-hook
> index 5b915af017..6e2d7588af 100755
> --- a/scripts/qemu-guest-agent/fsfreeze-hook
> +++ b/scripts/qemu-guest-agent/fsfreeze-hook
> @@ -24,15 +24,14 @@ USE_SYSLOG=0
>  # if log file is not writable, fallback to syslog
>  [ ! -w "$LOGFILE" ] && USE_SYSLOG=1
>  # try to update log file and fallback to syslog if it fails
> -touch "$LOGFILE" &>/dev/null || USE_SYSLOG=1
> +touch "$LOGFILE" >/dev/null 2>&1 || USE_SYSLOG=1
>
>  # Ensure the log file is writable, fallback to syslog if not
>  log_message() {
> -    local message="$1"
>      if [ "$USE_SYSLOG" -eq 0 ]; then
> -        printf "%s: %s\n" "$(date)" "$message" >>"$LOGFILE"
> +        printf "%s: %s\n" "$(date)" "$1" >>"$LOGFILE"
>      else
> -        logger -t qemu-ga-freeze-hook "$message"
> +        logger -t qemu-ga-freeze-hook "$1"
>      fi
>  }
>
> @@ -43,7 +42,7 @@ for file in "$FSFREEZE_D"/* ; do
>      is_ignored_file "$file" && continue
>      [ -x "$file" ] || continue
>
> -    log_message "Executing $file $@"
> +    log_message "Executing $file $*"
>      if [ "$USE_SYSLOG" -eq 0 ]; then
>          "$file" "$@" >>"$LOGFILE" 2>&1
>          STATUS=$?
> @@ -52,7 +51,7 @@ for file in "$FSFREEZE_D"/* ; do
>          STATUS=${PIPESTATUS[0]}
>      fi
>
> -    if [ $STATUS -ne 0 ]; then
> +    if [ "$STATUS" -ne 0 ]; then
>          log_message "Error: $file finished with status=$STATUS"
>      else
>          log_message "$file finished successfully"
> --
> 2.43.0
>
>