inject: skip tests when knob dir exists but knob doesn't

If the XFS error injection knob directory exists but the knob itself
doesn't, then we know that this kernel doesn't support the knob and
can skip the test.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

diff --git a/common/inject b/common/inject
index 903fb3790b92f7b2096cbb5e46298273af1150a9..984ec209281da1cae8d9ee8e0ea9c57e3097059f 100644 (file)
--- a/common/inject
+++ b/common/inject
@@ -62,6 +62,13 @@ _require_xfs_io_error_injection()
        knob="$(_find_xfs_mountdev_errortag_knob "${TEST_DEV}" "${type}")"
        test -w "${knob}" && return
 
+       # If the directory containing the sysfs error injection knob exists
+       # but the knob itself isn't usable, this kernel doesn't know about
+       # the knob.  Skip the test.
+       if [ -d "$(dirname "${knob}")" ]; then
+               _notrun "XFS error injection $type unknown on this kernel."
+       fi
+
        # NOTE: We can't actually test error injection here because xfs
        # hasn't always range checked the argument to xfs_errortag_add.
        # We also don't want to trip an error before we're ready to deal