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 --- a/214 +++ b/214 @@ -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?)" +_require_xfs_io_falloc # 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 status=0 exit -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
