The helper is used to test if a specific filesystem feature can
be enabled. Currently only implemented testing overlayfs features.
Overalyfs features (e.g. redirect_dir, index) are configurable from
Kconfig (the build default), by module parameter (the system default)
and per mount using the mount option ${feature}=[on|off].
The helper is going to be used by overlay tests, which depend
on the inodes index feature.
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
---
common/rc | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/common/rc b/common/rc
index b505365..260b48d 100644
--- a/common/rc
+++ b/common/rc
@@ -3626,6 +3626,54 @@ _get_fs_sysfs_attr()
cat /sys/fs/${FSTYP}/${dname}/${attr}
}
+# Print the value of a filesystem module parameter
+# at /sys/module/$FSTYP/parameters/$PARAM
+#
+# Usage example (FSTYP=overlay):
+# _get_fs_module_param index
+_get_fs_module_param()
+{
+ cat /sys/module/${FSTYP}/parameters/${1} 2>/dev/null
+}
+
+# Generic test for specific filesystem feature.
+# Currently only implemented to test overlayfs features.
+_require_fs_feature()
+{
+ local feature=$1
+
+ case "$FSTYP" in
+ overlay)
+ # overalyfs features (e.g. redirect_dir, index) are
+ # configurable from Kconfig (the build default), by module
+ # parameter (the system default) and per mount by mount
+ # option ${feature}=[on|off].
+ #
+ # If the module parameter does not exist then there is no
+ # point in checking the mount option.
+ local default=`_get_fs_module_param ${feature}`
+ [ "$default" = Y ] || [ "$default" = N ] || \
+ _notrun "feature '${feature}' not supported by ${FSTYP}"
+
+ _scratch_mkfs > /dev/null 2>&1
+ _scratch_mount -o ${feature}=on || \
+ _notrun "${FSTYP} feature '${feature}' cannot be enabled on ${SCRATCH_DEV}"
+ # Check options to be sure. For example, Overlayfs will fallback to
+ # index=off if underlying fs does not support file handles.
+ # Overlayfs only displays mount option if it differs from the default.
+ # Overlayfs may enable the feature, but fallback to read-only mount.
+ ((( [ "$default" = N ] && _fs_options $SCRATCH_DEV | grep -q "${feature}=on" ) || \
+ ( [ "$default" = Y ] && ! _fs_options $SCRATCH_DEV | grep -q "${feature}=off" )) && \
+ touch $SCRATCH_MNT/foo 2>/dev/null ) || \
+ _notrun "${FSTYP} feature '${feature}' cannot be enabled on ${SCRATCH_DEV}"
+ _scratch_unmount
+ ;;
+ *)
+ _fail "Test for feature '${feature}' of ${FSTYP} is not implemented"
+ ;;
+ esac
+}
+
init_rc
--
2.7.4
--
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