[PATCH v2 2/3] iotests: skip FUSE tests when FUSE is not usable

["Denis V. Lunev" <den@openvz.org>]

file-io-error, fuse-allow-other and fuse-mmap-shared skip only when
FUSE is not compiled in. When FUSE is built in but unusable at run
time (no /dev/fuse access, fusermount lacking permissions), the
export fails to mount with "Failed to mount FUSE session to export"
and the tests report a spurious failure instead of skipping, like
NBD tests already do for missing NBD support.

Add _notrun_on_fuse_error() to common.rc and use it in the shell
tests. fuse-mmap-shared is Python, so it gets an equivalent inline
check.

Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Kevin Wolf <kwolf@redhat.com>
CC: Hanna Reitz <hreitz@redhat.com>
---
 tests/qemu-iotests/common.rc              | 14 ++++++++++++++
 tests/qemu-iotests/tests/file-io-error    |  4 +---
 tests/qemu-iotests/tests/fuse-allow-other |  2 ++
 tests/qemu-iotests/tests/fuse-mmap-shared |  9 ++++++---
 4 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index 298bc483e0..bcb1ec50a9 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -981,6 +981,20 @@ _require_drivers()
     done
 }
 
+# Skip if FUSE is unusable: not compiled in, or the export failed to
+# mount. $1 is the failing 'block-export-add' reply.
+_notrun_on_fuse_error()
+{
+    case "$1" in
+        *"Parameter 'type' does not accept value 'fuse'"*)
+            _notrun "No FUSE support"
+            ;;
+        *"Failed to mount FUSE session"*)
+            _notrun "FUSE not usable in this environment"
+            ;;
+    esac
+}
+
 # Check that we have a file system that allows huge (but very sparse) files
 #
 _require_large_file()
diff --git a/tests/qemu-iotests/tests/file-io-error b/tests/qemu-iotests/tests/file-io-error
index fb8db73b31..0d970c102f 100755
--- a/tests/qemu-iotests/tests/file-io-error
+++ b/tests/qemu-iotests/tests/file-io-error
@@ -89,9 +89,7 @@ output=$(_send_qemu_cmd $QEMU_HANDLE \
     'return' \
     | grep -v 'option allow_other only allowed if')
 
-if echo "$output" | grep -q "Parameter 'type' does not accept value 'fuse'"; then
-    _notrun 'No FUSE support'
-fi
+_notrun_on_fuse_error "$output"
 echo "$output"
 
 echo
diff --git a/tests/qemu-iotests/tests/fuse-allow-other b/tests/qemu-iotests/tests/fuse-allow-other
index eaa39f8f23..50a36601d7 100755
--- a/tests/qemu-iotests/tests/fuse-allow-other
+++ b/tests/qemu-iotests/tests/fuse-allow-other
@@ -77,6 +77,8 @@ fuse_export_add()
         _notrun "allow_other not supported"
     fi
 
+    _notrun_on_fuse_error "$output"
+
     echo "$output"
 }
 
diff --git a/tests/qemu-iotests/tests/fuse-mmap-shared b/tests/qemu-iotests/tests/fuse-mmap-shared
index 52941a3bb6..b190105894 100755
--- a/tests/qemu-iotests/tests/fuse-mmap-shared
+++ b/tests/qemu-iotests/tests/fuse-mmap-shared
@@ -28,9 +28,12 @@ def test_fuse_support(mount_point):
     })
     test_qsd.stop()
     if 'error' in res:
-        assert (res['error']['desc'] ==
-                "Parameter 'type' does not accept value 'fuse'")
-        iotests.notrun('No FUSE support')
+        desc = res['error']['desc']
+        if desc == "Parameter 'type' does not accept value 'fuse'":
+            iotests.notrun('No FUSE support')
+        if 'Failed to mount FUSE session' in desc:
+            iotests.notrun('FUSE not usable in this environment')
+        assert False, desc
 
 # Shared mmap when using direct IO is only supported for Linux kernels >= 6.6
 # with commit e78662e818f94 ("fuse: add a new fuse init flag to relax
-- 
2.53.0