2 # SPDX-License-Identifier: GPL-2.0
3 # Copyright (c) 2017 Red Hat, Inc. All Rights Reserved.
7 # This test stresses indirect block reservation for delayed allocation extents.
8 # XFS reserves extra blocks for deferred allocation of delalloc extents. These
9 # reserved blocks can be divided among more extents than anticipated if the
10 # original extent for which the blocks were reserved is split into multiple
11 # delalloc extents. If this scenario repeats, eventually some extents are left
12 # without any indirect block reservation whatsoever. This leads to assert
13 # failures and possibly other problems in XFS.
16 seqres=$RESULT_DIR/$seq
17 echo "QA output created by $seq"
21 status=1 # failure is the default!
22 trap "_cleanup; exit \$status" 0 1 2 3 15
30 # get standard environment, filters and checks
35 # real QA test starts here
38 # Modify as appropriate.
42 _require_xfs_io_error_injection "drop_writes"
44 _scratch_mkfs >/dev/null 2>&1
47 sdev=$(_short_dev $SCRATCH_DEV)
48 file=$SCRATCH_MNT/file.$seq
51 # create sequential delayed allocation
52 $XFS_IO_PROG -f -c "pwrite 0 $bytes" $file >> $seqres.full 2>&1
54 # Enable write drops. All buffered writes are dropped from this point on.
55 _scratch_inject_error "drop_writes" 1
57 # Write every other 4k range to split the larger delalloc extent into many more
58 # smaller extents. Use pwrite because with write failures enabled, all
59 # preexisting delalloc blocks in the range of the I/O are tossed without
60 # discretion. This allows manipulation of the delalloc extent without conversion
61 # to real blocks (and thus releasing the indirect reservation).
62 endoff=$((bytes - 4096))
63 for i in $(seq 0 8192 $endoff); do
64 $XFS_IO_PROG -c "pwrite $i 4k" $file >> $seqres.full 2>&1
67 # now pwrite the opposite set to remove remaining delalloc extents
68 for i in $(seq 4096 8192 $endoff); do
69 $XFS_IO_PROG -c "pwrite $i 4k" $file >> $seqres.full 2>&1
72 _scratch_inject_error "drop_writes" 0
75 $XFS_IO_PROG -c 'bmap -vp' $file | _filter_bmap
77 # Now test a buffered write workload with larger extents. Write a 100m extent,
78 # split it at the 3/4 mark, then write another 100m extent that is contiguous
79 # with the 1/4 portion of the split extent. Repeat several times. This pattern
80 # is known to prematurely exhaust indirect reservations and cause warnings and
83 for offset in $(seq 0 100 500); do
84 $XFS_IO_PROG -fc "pwrite ${offset}m 100m" $file >> $seqres.full 2>&1
86 punchoffset=$((offset + 75))
87 _scratch_inject_error "drop_writes"
88 $XFS_IO_PROG -c "pwrite ${punchoffset}m 4k" $file >> $seqres.full 2>&1
89 _scratch_inject_error "drop_writes" 0
92 echo "Silence is golden."