[PATCH V2 05/11] xfs: Check for extent overflow when adding/removing xattrs

[Chandan Babu R <chandanrlinux@gmail.com>]

This test verifies that XFS does not cause inode fork's extent count to
overflow when adding/removing xattrs.

Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
---
 tests/xfs/525     | 176 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/xfs/525.out |  19 +++++
 tests/xfs/group   |   1 +
 3 files changed, 196 insertions(+)
 create mode 100755 tests/xfs/525
 create mode 100644 tests/xfs/525.out

diff --git a/tests/xfs/525 b/tests/xfs/525
new file mode 100755
index 00000000..07061bbe
--- /dev/null
+++ b/tests/xfs/525
@@ -0,0 +1,176 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2020 Chandan Babu R.  All Rights Reserved.
+#
+# FS QA Test 525
+#
+# Verify that XFS does not cause inode fork's extent count to overflow when
+# Adding/removing xattrs.
+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 /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/attr
+. ./common/inject
+. ./common/populate
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+_supported_fs xfs
+_require_scratch
+_require_attrs
+_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"
+
+echo "Format and mount fs"
+_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full
+_scratch_mount >> $seqres.full
+
+bsize=$(_get_block_size $SCRATCH_MNT)
+
+# To be able to remove xattr entries in a situation where inserting new xattrs
+# is prevented due to possible extent count overflow , each xattr insert
+# operation should reserve an extent count for deletion of maximum sized xattr
+# apart from the extent count required for the xattr insert operation being
+# performed.
+#
+# The following table gives an estimation of the total extent count that needs
+# to be reserved for maximum sized "local" xattr insert operation for various
+# block sizes,
+#
+# |-------+----------------------------------------+----------------------------------|
+# | Block |         Worst case remove extent count |                     Total extent |
+# |  size | (XFS_DA_NODE_MAXDEPTH + (64k / bsize)) |                            count |
+# |       |                                        | (Xattr insert extent count (6) + |
+# |       |                                        |  Worst case remove extent count) |
+# |-------+----------------------------------------+----------------------------------|
+# |  1024 |                                     69 |                               75 |
+# |  2048 |                                     37 |                               43 |
+# |  4096 |                                     22 |                               28 |
+# | 32768 |                                      7 |                               13 |
+# | 65536 |                                      6 |                               12 |
+# |-------+----------------------------------------+----------------------------------|
+# Note: Xattr insert extent count = XFS_DA_NODE_MAXDEPTH + 1 = 6.
+#
+# 35 (which is > 28) has been chosen as the pseudo maximum extent count in the
+# XFS kernel module. Hence xattr tests are limited to block sizes >= 4k.
+
+if (( $bsize < 4096 )); then
+	_notrun "FSB size ($bsize) is less than 4k"
+fi
+
+attr_len=255
+
+testfile=$SCRATCH_MNT/testfile
+
+echo "Consume free space"
+fillerdir=$SCRATCH_MNT/fillerdir
+nr_free_blks=$(stat -f -c '%f' $SCRATCH_MNT)
+nr_free_blks=$((nr_free_blks * 90 / 100))
+
+_fill_fs $((bsize * nr_free_blks)) $fillerdir $bsize 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 "* Set xattrs"
+
+echo "Create \$testfile"
+touch $testfile
+
+echo "Create xattrs"
+nr_attrs=$((bsize * 45 / attr_len))
+for i in $(seq 1 $nr_attrs); do
+	attr="$(printf "trusted.%0247d" $i)"
+	$SETFATTR_PROG -n "$attr" $testfile >> $seqres.full 2>&1
+	[[ $? != 0 ]] && break
+done
+
+echo "Verify \$testfile's naextent count"
+
+naextents=$($XFS_IO_PROG -f -c 'stat' $testfile | grep naextents)
+naextents=${naextents##fsxattr.naextents = }
+if (( $naextents > 35 )); then
+	echo "Extent count overflow check failed: naextents = $naextents"
+	exit 1
+fi
+
+echo "Remove one xattr"
+attr="$(printf "trusted.%0247d" 1)"
+$SETFATTR_PROG -x "$attr" $testfile
+
+echo "Remove \$testfile"
+rm $testfile
+
+echo "* Remove xattrs"
+
+echo "Create \$testfile"
+touch $testfile
+
+echo "Disable reduce_max_iextents error tag"
+_scratch_inject_error reduce_max_iextents 0
+
+echo "Create initial xattr extents"
+
+naextents=0
+last=""
+start=1
+nr_attrs=$((bsize / attr_len))
+
+while (( $naextents < 30 )); do
+	end=$((start + nr_attrs - 1))
+
+	for i in $(seq $start $end); do
+		attr="$(printf "trusted.%0247d" $i)"
+		$SETFATTR_PROG -n $attr $testfile
+	done
+		
+	start=$((end + 1))
+
+	naextents=$($XFS_IO_PROG -f -c 'stat' $testfile | grep naextents)
+	naextents=${naextents##fsxattr.naextents = }
+done
+
+echo "Inject reduce_max_iextents error tag"
+_scratch_inject_error reduce_max_iextents 1
+
+echo "Remove xattr to trigger -EFBIG"
+attr="$(printf "trusted.%0247d" 1)"
+$SETFATTR_PROG -x "$attr" $testfile >> $seqres.full 2>&1
+if [[ $? == 0 ]]; then
+	echo "Xattr removal succeeded; Should have failed "
+	exit 1
+fi
+
+rm $testfile && echo "Successfully removed \$testfile"
+
+# success, all done
+status=0
+exit
diff --git a/tests/xfs/525.out b/tests/xfs/525.out
new file mode 100644
index 00000000..c90dc873
--- /dev/null
+++ b/tests/xfs/525.out
@@ -0,0 +1,19 @@
+QA output created by 525
+Format and mount fs
+Consume free space
+Create fragmented filesystem
+Inject reduce_max_iextents error tag
+Inject bmap_alloc_minlen_extent error tag
+* Set xattrs
+Create $testfile
+Create xattrs
+Verify $testfile's naextent count
+Remove one xattr
+Remove $testfile
+* Remove xattrs
+Create $testfile
+Disable reduce_max_iextents error tag
+Create initial xattr extents
+Inject reduce_max_iextents error tag
+Remove xattr to trigger -EFBIG
+Successfully removed $testfile
diff --git a/tests/xfs/group b/tests/xfs/group
index 7031cabf..bfaac6aa 100644
--- a/tests/xfs/group
+++ b/tests/xfs/group
@@ -522,6 +522,7 @@
 522 auto quick quota
 523 auto quick realtime growfs
 524 auto quick punch zero insert collapse
+525 auto quick attr
 758 auto quick rw attr realtime
 759 auto quick rw realtime
 760 auto quick rw collapse punch insert zero prealloc
-- 
2.29.2