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 _begin_fstest auto quick
16 # Override the default cleanup function.
22 echo $$ > $cgdir/cgroup.procs
23 rmdir $cgdir/$seq-cg* > /dev/null 2>&1
24 umount $SCRATCH_MNT > /dev/null 2>&1
25 _destroy_loop_device $LOOP_DEV > /dev/null 2>&1
28 # Import common functions.
32 # real QA test starts here
34 # Modify as appropriate.
36 _require_scratch_nocheck
40 # cgroup v2 writeback is only support on block devices so far
41 _require_block_device $SCRATCH_DEV
44 iosize=$((1024 * 1024 * 8))
46 # Check cgroup read/write charges against expected values. Allow for some
47 # tolerance as different filesystems seem to account slightly differently.
51 cgname=$(basename $cgroot)
59 iobytes=`cat $cgroot/io.stat | grep $smajor:$sminor`
61 rbytes=`echo $iobytes | awk '{ print $2 }' | \
62 awk -F = '{ print $2 }'`
63 wbytes=`echo $iobytes | awk '{ print $3 }' | \
64 awk -F = '{ print $2 }'`
67 _within_tolerance "read" $rbytes $expectedread $readtol -v
68 _within_tolerance "write" $wbytes $expectedwrite $writetol -v
71 # Move current process to another cgroup.
75 echo $$ > $1/cgroup.procs
78 # Reset cgroup state for a new test.
81 echo $$ > $cgdir/cgroup.procs
82 rmdir $cgdir/$seq-cg* > /dev/null 2>&1
83 $XFS_IO_PROG -fc "pwrite 0 $iosize" $SCRATCH_MNT/file \
85 umount $SCRATCH_MNT || _fail "umount failed"
86 _mount $LOOP_DEV $SCRATCH_MNT || _fail "mount failed"
87 stat $SCRATCH_MNT/file > /dev/null
90 # cgroup I/O accounting doesn't work on partitions. Use a loop device to rule
92 LOOP_DEV=$(_create_loop_device $SCRATCH_DEV)
93 smajor=$((0x`stat -L -c %t $LOOP_DEV`))
94 sminor=$((0x`stat -L -c %T $LOOP_DEV`))
96 _mkfs_dev $LOOP_DEV >> $seqres.full 2>&1
97 _mount $LOOP_DEV $SCRATCH_MNT || _fail "mount failed"
100 grep -q -w io $cgdir/cgroup.subtree_control || drop_io_cgroup=1
102 echo "+io" > $cgdir/cgroup.subtree_control || _fail "subtree control"
104 # Read and write from a single group.
107 switch_cg $cgdir/$seq-cg
108 $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" -c fsync \
109 $SCRATCH_MNT/file >> $seqres.full 2>&1
111 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
112 check_cg $cgdir/$seq-cg $iosize $iosize 5% 5%
114 # Write from one cgroup then read and write from a second. Writes are charged to
115 # the first group and nothing to the second.
116 echo "write -> read/write"
118 switch_cg $cgdir/$seq-cg
119 $XFS_IO_PROG -c "pwrite 0 $iosize" $SCRATCH_MNT/file >> $seqres.full 2>&1
120 switch_cg $cgdir/$seq-cg-2
121 $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" $SCRATCH_MNT/file \
124 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
125 # Use a fixed value tolerance for the expected value of zero here
126 # because filesystems might perform a small number of metadata reads to
127 # complete the write. On ext2/3 with 1k block size, the read bytes is
129 check_cg $cgdir/$seq-cg 0 $iosize 33792 5%
130 check_cg $cgdir/$seq-cg-2 0 0 0 0
132 # Read from one cgroup, read & write from a second. Both reads and writes are
133 # charged to the first group and nothing to the second.
134 echo "read -> read/write"
136 switch_cg $cgdir/$seq-cg
137 $XFS_IO_PROG -c "pread 0 $iosize" $SCRATCH_MNT/file >> $seqres.full 2>&1
138 switch_cg $cgdir/$seq-cg-2
139 $XFS_IO_PROG -c "pread 0 $iosize" -c "pwrite 0 $iosize" $SCRATCH_MNT/file \
142 $XFS_IO_PROG -c fsync $SCRATCH_MNT/file
143 check_cg $cgdir/$seq-cg $iosize $iosize 5% 5%
144 check_cg $cgdir/$seq-cg-2 0 0 0 0
146 if [ "$drop_io_cgroup" = 1 ]; then
147 echo "-io" > $cgdir/cgroup.subtree_control || _fail "subtree control"