[PATCH V3 1/4] xfs/270: Fix ro mount failure when nrext64 option is enabled

From: Chandan Babu R <chandan.babu@oracle.com>
To: fstests@vger.kernel.org
Cc: Chandan Babu R <chandan.babu@oracle.com>,
	zlang@kernel.org, david@fromorbit.com, djwong@kernel.org,
	linux-xfs@vger.kernel.org
Subject: [PATCH V3 1/4] xfs/270: Fix ro mount failure when nrext64 option is enabled
Date: Sat, 11 Jun 2022 16:40:34 +0530	[thread overview]
Message-ID: <20220611111037.433134-2-chandan.babu@oracle.com> (raw)
In-Reply-To: <20220611111037.433134-1-chandan.babu@oracle.com>

With nrext64 option enabled at run time, the read-only mount performed by the
test fails because,
1. mkfs.xfs would have calculated log size based on reflink being enabled.
2. Clearing the reflink ro compat bit causes log size calculations to yield a
   different value.
3. In the case where nrext64 is enabled, this causes attr reservation to be
   the largest among all the transaction reservations.
4. This ends up causing XFS to require a larger ondisk log size than that
   which is available.

This commit fixes the problem by setting features_ro_compat to the value
obtained by the bitwise-OR of features_ro_compat field with 2^31.

This commit includes changes suggested by Dave Chinner to replace bashisms
with invocations to inline awk scripts.

Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
---
 tests/xfs/270     | 26 ++++++++++++++++++++++++--
 tests/xfs/270.out |  1 -
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/tests/xfs/270 b/tests/xfs/270
index 0ab0c7d8..b740c379 100755
--- a/tests/xfs/270
+++ b/tests/xfs/270
@@ -27,8 +27,30 @@ _scratch_mkfs_xfs >>$seqres.full 2>&1
 # set the highest bit of features_ro_compat, use it as an unknown
 # feature bit. If one day this bit become known feature, please
 # change this case.
-_scratch_xfs_set_metadata_field "features_ro_compat" "$((2**31))" "sb 0" | \
-	grep 'features_ro_compat'
+
+ro_compat=$(_scratch_xfs_get_metadata_field "features_ro_compat" "sb 0")
+echo $ro_compat | grep -q -E '^0x[[:xdigit:]]$'
+if [[ $? != 0  ]]; then
+	echo "features_ro_compat has an invalid value."
+fi
+
+ro_compat=$(echo $ro_compat | \
+		    awk '/^0x[[:xdigit:]]+/ {
+				printf("0x%x\n", or(strtonum($1), 0x80000000))
+			}')
+
+# write the new ro compat field to the superblock
+_scratch_xfs_set_metadata_field "features_ro_compat" "$ro_compat" "sb 0" \
+				> $seqres.full 2>&1
+
+# read the newly set ro compat filed for verification
+new_ro_compat=$(_scratch_xfs_get_metadata_field "features_ro_compat" "sb 0" \
+						2>/dev/null)
+
+# verify the new ro_compat field is correct.
+if [ $new_ro_compat != $ro_compat ]; then
+	echo "Unable to set new features_ro_compat. Wanted $ro_compat, got $new_ro_compat"
+fi
 
 # rw mount with unknown ro-compat feature should fail
 echo "rw mount test"
diff --git a/tests/xfs/270.out b/tests/xfs/270.out
index 0a8b3851..edf4c254 100644
--- a/tests/xfs/270.out
+++ b/tests/xfs/270.out
@@ -1,5 +1,4 @@
 QA output created by 270
-features_ro_compat = 0x80000000
 rw mount test
 ro mount test
 rw remount test
-- 
2.35.1

