2 # SPDX-License-Identifier: GPL-2.0
3 # Copyright (c) 2019 Red Hat, Inc. All Rights Reserved.
7 # This test verifies that cgroup aware writeback properly accounts I/Os in
8 # various scenarios. We perform reads/writes from different combinations of
9 # cgroups and verify that pages are accounted against the group that brought
14 seqres=$RESULT_DIR/$seq
15 echo "QA output created by $seq"
19 status=1 # failure is the default!
20 trap "_cleanup; exit \$status" 0 1 2 3 15
27 echo $$ > $cgdir/cgroup.procs
28 rmdir $cgdir/$seq-cg* > /dev/null 2>&1
29 umount $SCRATCH_MNT > /dev/null 2>&1
30 _destroy_loop_device $LOOP_DEV > /dev/null 2>&1
33 # get standard environment, filters and checks
38 # remove previous $seqres.full before test
41 # real QA test starts here
43 # Modify as appropriate.
45 _require_scratch_nocheck
49 # cgroup v2 writeback is only support on block devices so far
50 _require_block_device $SCRATCH_DEV
53 iosize=$((1024 * 1024 * 8))
55 # Check cgroup read/write charges against expected values. Allow for some
56 # tolerance as different filesystems seem to account slightly differently.
60 cgname=$(basename $cgroot)
68 iobytes=`cat $cgroot/io.stat | grep $smajor:$sminor`
70 rbytes=`echo $iobytes | awk '{ print $2 }' | \
71 awk -F = '{ print $2 }'`
72 wbytes=`echo $iobytes | awk '{ print $3 }' | \
73 awk -F = '{ print $2 }'`
76 _within_tolerance "read" $rbytes $expectedread $readtol -v
77 _within_tolerance "write" $wbytes $expectedwrite $writetol -v
80 # Move current process to another cgroup.
84 echo $$ > $1/cgroup.procs
87 # Reset cgroup state for a new test.
90 echo $$ > $cgdir/cgroup.procs
91 rmdir $cgdir/$seq-cg* > /dev/null 2>&1
92 $XFS_IO_PROG -fc "pwrite 0 $iosize" $SCRATCH_MNT/file \
94 umount $SCRATCH_MNT || _fail "umount failed"
95 _mount $LOOP_DEV $SCRATCH_MNT || _fail "mount failed"
96 stat $SCRATCH_MNT/file > /dev/null
99 # cgroup I/O accounting doesn't work on partitions. Use a loop device to rule
101 LOOP_DEV=$(_create_loop_device $SCRATCH_DEV)
102 smajor=$((0x`stat -L -c %t $LOOP_DEV`))
103 sminor=$((0x`stat -L -c %T $LOOP_DEV`))
105 _mkfs_dev $LOOP_DEV >> $seqres.full 2>&1
106 _mount $LOOP_DEV $SCRATCH_MNT || _fail "mount failed"
109 grep -q -w io $cgdir/cgroup.subtree_control || drop_io_cgroup=1
111 echo "+io" > $cgdir/cgroup.subtree_control || _fail "subtree control"
113 # Read and write from a single group.
116 switch_cg $cgdir/$seq-cg
117 $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" -c fsync \
118 $SCRATCH_MNT/file >> $seqres.full 2>&1
120 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
121 check_cg $cgdir/$seq-cg $iosize $iosize 5% 5%
123 # Write from one cgroup then read and write from a second. Writes are charged to
124 # the first group and nothing to the second.
125 echo "write -> read/write"
127 switch_cg $cgdir/$seq-cg
128 $XFS_IO_PROG -c "pwrite 0 $iosize" $SCRATCH_MNT/file >> $seqres.full 2>&1
129 switch_cg $cgdir/$seq-cg-2
130 $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" $SCRATCH_MNT/file \
133 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
134 # Use a fixed value tolerance for the expected value of zero here
135 # because filesystems might perform a small number of metadata reads to
136 # complete the write. On ext2/3 with 1k block size, the read bytes is
138 check_cg $cgdir/$seq-cg 0 $iosize 33792 5%
139 check_cg $cgdir/$seq-cg-2 0 0 0 0
141 # Read from one cgroup, read & write from a second. Both reads and writes are
142 # charged to the first group and nothing to the second.
143 echo "read -> read/write"
145 switch_cg $cgdir/$seq-cg
146 $XFS_IO_PROG -c "pread 0 $iosize" $SCRATCH_MNT/file >> $seqres.full 2>&1
147 switch_cg $cgdir/$seq-cg-2
148 $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" $SCRATCH_MNT/file \
151 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
152 check_cg $cgdir/$seq-cg $iosize $iosize 5% 5%
153 check_cg $cgdir/$seq-cg-2 0 0 0 0
155 if [ "$drop_io_cgroup" = 1 ]; then
156 echo "-io" > $cgdir/cgroup.subtree_control || _fail "subtree control"