| #! /bin/bash |
| # SPDX-License-Identifier: GPL-2.0 |
| # Copyright (c) 2017 Red Hat, Inc. All Rights Reserved. |
| # |
| # FS QA Test No. 433 |
| # |
| # Regression test for an XFS NULL xattr buffer problem during unlink. XFS had a |
| # bug where the attr fork walk during file removal could go off the rails due to |
| # a stale reference to content of a released buffer. Memory pressure could cause |
| # this reference to point to free or reused memory and cause subsequent |
| # attribute fork lookups to fail, return a NULL buffer and possibly crash. |
| # |
| # This test emulates this behavior using an error injection knob to explicitly |
| # disable buffer LRU caching. This forces the attr walk to execute under |
| # conditions where each buffer is immediately freed on release. |
| # |
| # Commit f35c5e10c6ed ("xfs: reinit btree pointer on attr tree inactivation |
| # walk") fixed the bug. |
| # |
| . ./common/preamble |
| _begin_fstest auto quick attr |
| |
| # Import common functions. |
| . ./common/attr |
| . ./common/inject |
| |
| # real QA test starts here |
| |
| # Modify as appropriate. |
| _supported_fs generic |
| _require_xfs_io_error_injection buf_lru_ref |
| _require_scratch |
| _require_attrs |
| |
| _scratch_mkfs > $seqres.full 2>&1 |
| _scratch_mount |
| |
| file=$SCRATCH_MNT/testfile |
| |
| # create a bunch of xattrs to form a multi-level attr tree |
| touch $file |
| for i in $(seq 0 499); do |
| $SETFATTR_PROG -n trusted.user.$i -v 0 $file |
| done |
| |
| # cycle the mount to clear any buffer references |
| _scratch_cycle_mount || _fail "cycle mount failure" |
| |
| # disable the lru cache and unlink the file |
| _scratch_inject_error buf_lru_ref 1 |
| rm -f $file |
| _scratch_inject_error buf_lru_ref 0 |
| |
| echo Silence is golden |
| |
| # success, all done |
| status=0 |
| exit |