Btrfs had a deadlock that you could trigger by mmap'ing a large file and using that as the buffer for fiemap. This test adds a c program to do this, and the fstest creates a large enough file and then runs the reproducer on the file. Without the fix btrfs deadlocks, with the fix we pass fine. Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx> --- src/Makefile | 2 +- tests/generic/740 | 41 +++++++++++++++++++++++++++++++++++++++++ tests/generic/740.out | 2 ++ 3 files changed, 44 insertions(+), 1 deletion(-) create mode 100644 tests/generic/740 create mode 100644 tests/generic/740.out diff --git a/src/Makefile b/src/Makefile index d79015ce..916f6755 100644 --- a/src/Makefile +++ b/src/Makefile @@ -34,7 +34,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \ attr_replace_test swapon mkswap t_attr_corruption t_open_tmpfiles \ fscrypt-crypt-util bulkstat_null_ocount splice-test chprojid_fail \ detached_mounts_propagation ext4_resize t_readdir_3 splice2pipe \ - uuid_ioctl + uuid_ioctl fiemap-fault EXTRA_EXECS = dmerror fill2attr fill2fs fill2fs_check scaleread.sh \ btrfs_crc32c_forged_name.py popdir.pl popattr.py \ diff --git a/tests/generic/740 b/tests/generic/740 new file mode 100644 index 00000000..46ec5820 --- /dev/null +++ b/tests/generic/740 @@ -0,0 +1,41 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2023 Meta Platforms, Inc. All Rights Reserved. +# +# FS QA Test 708 +# +# Test fiemap into an mmaped buffer of the same file +# +# Create a reasonably large file, then run a program which mmaps it and uses +# that as a buffer for an fiemap call. This is a regression test for btrfs +# where we used to hold a lock for the duration of the fiemap call which would +# result in a deadlock if we page faulted. +# +. ./common/preamble +_begin_fstest quick auto +[ $FSTYP == "btrfs" ] && \ + _fixed_by_kernel_commit xxxxxxxxxxxx \ + "btrfs: fix deadlock with fiemap and extent locking" + +# real QA test starts here +_supported_fs generic +_require_test +_require_odirect +_require_test_program fiemap-fault +dst=$TEST_DIR/fiemap-fault-$seq + +echo "Silence is golden" + +for i in $(seq 0 2 1000) +do + $XFS_IO_PROG -d -f -c "pwrite -q $((i * 4096)) 4096" $dst +done + +$here/src/fiemap-fault $dst > /dev/null || _fail "failed doing fiemap" + +rm -f $dst + +# success, all done +status=$? +exit + diff --git a/tests/generic/740.out b/tests/generic/740.out new file mode 100644 index 00000000..3f841e60 --- /dev/null +++ b/tests/generic/740.out @@ -0,0 +1,2 @@ +QA output created by 740 +Silence is golden -- 2.43.0
