xfs: Check for extent overflow when growing realtime bitmap/summary inodes

Verify that XFS does not cause realtime bitmap/summary inode fork's
extent count to overflow when growing the realtime volume associated
with a filesystem.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>

tests/xfs/530

@@ -0,0 +1,124 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Chandan Babu R.  All Rights Reserved.
+#
+# FS QA Test 530
+#
+# Verify that XFS does not cause bitmap/summary inode fork's extent count to
+# overflow when growing an the realtime volume of the filesystem.
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	_scratch_unmount >> $seqres.full 2>&1
+	test -e "$rtdev" && losetup -d $rtdev >> $seqres.full 2>&1
+	rm -f $tmp.* $TEST_DIR/$seq.rtvol
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/inject
+. ./common/populate
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+_supported_fs xfs
+# Note that we don't _require_realtime because we synthesize a rt volume
+# below.
+_require_test
+_require_xfs_debug
+_require_test_program "punch-alternating"
+_require_xfs_io_error_injection "reduce_max_iextents"
+_require_xfs_io_error_injection "bmap_alloc_minlen_extent"
+_require_scratch_nocheck
+
+echo "* Test extending rt inodes"
+
+_scratch_mkfs | _filter_mkfs >> $seqres.full 2> $tmp.mkfs
+. $tmp.mkfs
+
+echo "Create fake rt volume"
+nr_bitmap_blks=25
+nr_bits=$((nr_bitmap_blks * dbsize * 8))
+
+# Realtime extent size has to be atleast 4k in size.
+if (( $dbsize < 4096 )); then
+	rtextsz=4096
+else
+	rtextsz=$dbsize
+fi
+
+rtdevsz=$((nr_bits * rtextsz))
+truncate -s $rtdevsz $TEST_DIR/$seq.rtvol
+rtdev=$(_create_loop_device $TEST_DIR/$seq.rtvol)
+
+echo "Format and mount rt volume"
+
+export USE_EXTERNAL=yes
+export SCRATCH_RTDEV=$rtdev
+_scratch_mkfs -d size=$((1024 * 1024 * 1024)) -b size=${dbsize} \
+	      -r size=${rtextsz},extsize=${rtextsz} >> $seqres.full
+_try_scratch_mount || _notrun "Couldn't mount fs with synthetic rt volume"
+
+echo "Consume free space"
+fillerdir=$SCRATCH_MNT/fillerdir
+nr_free_blks=$(stat -f -c '%f' $SCRATCH_MNT)
+nr_free_blks=$((nr_free_blks * 90 / 100))
+
+_fill_fs $((dbsize * nr_free_blks)) $fillerdir $dbsize 0 >> $seqres.full 2>&1
+
+echo "Create fragmented filesystem"
+for dentry in $(ls -1 $fillerdir/); do
+	$here/src/punch-alternating $fillerdir/$dentry >> $seqres.full
+done
+
+echo "Inject reduce_max_iextents error tag"
+_scratch_inject_error reduce_max_iextents 1
+
+echo "Inject bmap_alloc_minlen_extent error tag"
+_scratch_inject_error bmap_alloc_minlen_extent 1
+
+echo "Grow realtime volume"
+$XFS_GROWFS_PROG -r $SCRATCH_MNT >> $seqres.full 2>&1
+if [[ $? == 0 ]]; then
+	echo "Growfs succeeded; should have failed."
+	exit 1
+fi
+
+_scratch_unmount >> $seqres.full
+
+echo "Verify rbmino's and rsumino's extent count"
+for rtino in rbmino rsumino; do
+	ino=$(_scratch_xfs_get_metadata_field $rtino "sb 0")
+	echo "$rtino = $ino" >> $seqres.full
+
+	nextents=$(_scratch_get_iext_count $ino data || \
+			_fail "Unable to obtain inode fork's extent count")
+	if (( $nextents > 10 )); then
+		echo "Extent count overflow check failed: nextents = $nextents"
+		exit 1
+	fi
+done
+
+echo "Check filesystem"
+_check_xfs_filesystem $SCRATCH_DEV none $rtdev
+
+losetup -d $rtdev
+rm -f $TEST_DIR/$seq.rtvol
+
+# success, all done
+status=0
+exit

tests/xfs/530.out

@@ -0,0 +1,11 @@
+QA output created by 530
+* Test extending rt inodes
+Create fake rt volume
+Format and mount rt volume
+Consume free space
+Create fragmented filesystem
+Inject reduce_max_iextents error tag
+Inject bmap_alloc_minlen_extent error tag
+Grow realtime volume
+Verify rbmino's and rsumino's extent count
+Check filesystem

tests/xfs/group

@@ -506,3 +506,4 @@
 527 auto quick quota
 528 auto quick rw realtime
 529 auto quick quota
+530 auto quick realtime growfs