2 # FS QA Test No. btrfs/086
4 # Test cloning a file range with a length of zero into a destination offset
7 # This made btrfs create an extent state record with a start offset greater than
8 # the end offset, resulting in chaos such as an infinite loop when evicting an
11 # This issue was fixed by the following linux kernel patch:
13 # Btrfs: fix inode eviction infinite loop after cloning into it
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17 # Author: Filipe Manana <fdmanana@suse.com>
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35 seqres=$RESULT_DIR/$seq
36 echo "QA output created by $seq"
39 status=1 # failure is the default!
40 trap "_cleanup; exit \$status" 0 1 2 3 15
47 # get standard environment, filters and checks
51 # real QA test starts here
59 _scratch_mkfs >>$seqres.full 2>&1
62 touch $SCRATCH_MNT/foo
63 touch $SCRATCH_MNT/bar
65 # Now attempt to clone foo into bar. Because we pass a length of zero, the
66 # clone ioctl will adjust the length to match the size of the file foo (minus
67 # the source offset which is zero) - because the adjusted length value is
68 # zero, it made btrfs create an extent state record for file bar with a start
69 # offset (64k) greater then its end offset (64k - 1), which is something never
70 # supposed to happen and for example it made inode eviction enter an infinite
71 # loop that dumped a warning trace on each iteration.
72 $CLONER_PROG -s 0 -d 65536 -l 0 $SCRATCH_MNT/foo $SCRATCH_MNT/bar
73 echo "bar file size after clone operation: $(stat -c %s $SCRATCH_MNT/bar)"