ext4 had a regression where it double-accounted used blocks
if you fallocated on top of delalloc blocks. Ted sent a
c program to exploit it (see "fsstress-induced corruption reproduced"
on linux-ext4 on 12/31/2009) and it's trivial to do the same thing
within the xfstests framework using xfs_io.
This also changes the handcrafted xfs_io tests to use the
_require_xfs_io_falloc helper, not sure how that got missed.
Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
diff --git a/214 b/214
index 98cfc3a..35ec2cb 100755
@@ -52,14 +52,7 @@ _supported_os Linux
rm -f $seq.full
-testio=`$XFS_IO_PROG -F -f -c "falloc 0 1m" $TEST_DIR/$tmp.io 2>&1`
-# Old xfs_io doesn't have fallocate support
-echo $testio | grep -q "not found" && \
- _notrun "xfs_io fallocate support is missing"
-# Old glibc, old kernels, and some filesystems don't have fallocate support
-echo $testio | grep -q "Operation not supported" && \
- _notrun "xfs_io fallocate command failed (old kernel? wrong fs?)"
# Ok, off we go.
@@ -126,6 +119,20 @@ $XFS_IO_PROG -F -f -d \
rm -f $TEST_DIR/ouch
+# Reported by Ted Ts'o on linux-ext4, 12/31/2009
+# double-allocation on ext4 when fallocating over delalloc blocks
+# Regression due to d21cd8f163ac44b15c465aab7306db931c606908
+echo "=== delalloc write 16k; fallocate same range ==="
+# delalloc write 16k, fallocate same range.
+# Should get caught on fsck when we're done.
+$XFS_IO_PROG -F -f \
+ -c "pwrite 0 16k" \
+ -c "falloc 0 16k" \
+ -c "fsync" \
+ $TEST_DIR/ouch2 | _filter_xfs_io_unique
# success, all done