zfs-initramfs on debian: zfs_debug interfers with ask_user_snap

[cfellinger]

running debian jessie, initramfs 5.6.5.6-5, booting with zfs_debug=yes and an empty or a non-existing snapshot makes the ask_user_snap output to become invisible. answering the invisible question (1 enter) results in a proper boot, whereas a plain enter results in this:

[FransUrbo]

Please test these two patches:

--- /etc/zfs/zfs-functions~     2016-04-17 20:49:18.226373449 +0100
+++ /etc/zfs/zfs-functions      2016-04-18 11:20:55.020041123 +0100
@@ -388,6 +388,37 @@
           /proc/cmdline
 }

+# Disable debugging
+disable_debug()
+{
+       if [ -n "${ZFS_DEBUG}" ]; then
+               unset ZFS_DEBUG
+               set +x
+       fi
+
+       # Restore STDERR from #6.
+       exec 2<&6 6<&-
+}
+
+# Enable debugging
+enable_debug()
+{
+       ZFS_DEBUG=1
+       mkdir -p /var/log
+
+       # Save STDERR as #6.
+       exec 6<&2
+
+       # Close and reopen STDERR and redirect it.
+       exec 2<&-
+
+       [ -f "/var/log/zfs-boot.debug" ] && \
+               exec 2>> /var/log/zfs-boot.debug || \
+               exec 2>  /var/log/zfs-boot.debug
+
+       set -x
+}
+
 # Check if the specified module is loaded.
 check_module_loaded()
 {
@@ -1019,13 +1050,9 @@
        local i=1
        local SNAP snapnr snap debug

-       # We need to temporarily disable debugging. Set 'debug' so we
-       # remember to enabled it again.
-       if [ -n "${ZFS_DEBUG}" ]; then
-               unset ZFS_DEBUG
-               set +x
-               debug=1
-       fi
+       # We need to temporarily disable debugging because it interferes with the output.
+       # Set 'debug' so we remember to enabled it again.
+       disable_debug ; debug=1

        # Because we need the resulting snapshot, which is sent on
        # stdout to the caller, we use stderr for our questions.
@@ -1046,10 +1073,7 @@
        read snapnr

        # Reenable debugging.
-       if [ -n "${debug}" ]; then
-               ZFS_DEBUG=1
-               set -x
-       fi
+       [ -n "${debug}" ] && enable_debug

        echo "$(eval echo "$"SNAP_${snapnr})"
 }

--- /usr/share/initramfs-tools/scripts/zfs~     2016-04-17 18:18:16.283302248 +0100
+++ /usr/share/initramfs-tools/scripts/zfs      2016-04-18 11:07:56.015928425 +0100
@@ -103,17 +103,7 @@

        # ------------
        # Support debug option
-       if check_zfs_debug
-       then
-               ZFS_DEBUG=1
-               mkdir /var/log
-
-               # Close and reopen STDERR and redirect it.
-               exec 2<&-
-               exec 2> /var/log/zfs-boot.debug
-
-               set -x
-       fi
+       check_zfs_debug && enable_debug

        # ------------
        # Load ZFS module etc.

[FransUrbo]

Sorry, that won't work properly if NOT zfsdebug=1. Try this:

# Disable debugging
disable_debug()
{
        if check_zfs_debug
        then
                unset ZFS_DEBUG
                set +x

                # Restore STDERR from #6.
                exec 2<&6 6<&-
        fi
}

[FransUrbo]

This is fixed in the new v0.6.5.6-6 which is on its way up to the repository.

[cfellinger]

sorry it took me so long to test, but I'm glad its fixed. Yes, it works here too.