diff options
author | Josef Bacik <josef@toxicpanda.com> | 2024-03-20 11:46:50 -0400 |
---|---|---|
committer | Zorro Lang <zlang@kernel.org> | 2024-03-30 15:48:12 +0800 |
commit | 34cdaf0831ee423051030999aebb4d19298f826e (patch) | |
tree | f99d2f8bb66ce6e448aeac1ce50cf8bd62420b65 | |
parent | 9e760cfa976bafbe51608650ea08257e4e8bae9a (diff) | |
download | xfstests-dev-34cdaf0831ee423051030999aebb4d19298f826e.tar.gz |
generic: add a regression test for fiemap into an mmap range
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@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Zorro Lang <zlang@redhat.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>
-rw-r--r-- | .gitignore | 1 | ||||
-rw-r--r-- | src/Makefile | 2 | ||||
-rw-r--r-- | src/fiemap-fault.c | 74 | ||||
-rwxr-xr-x | tests/generic/742 | 50 | ||||
-rw-r--r-- | tests/generic/742.out | 2 |
5 files changed, 128 insertions, 1 deletions
diff --git a/.gitignore b/.gitignore index 3b160209ac..18815b35fd 100644 --- a/.gitignore +++ b/.gitignore @@ -205,6 +205,7 @@ tags /src/vfs/mount-idmapped /src/log-writes/replay-log /src/perf/*.pyc +/src/fiemap-fault # Symlinked files /tests/generic/035.out diff --git a/src/Makefile b/src/Makefile index e7442487bc..ab98a06f49 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 t_snapshot_deleted_subvolume + uuid_ioctl t_snapshot_deleted_subvolume fiemap-fault EXTRA_EXECS = dmerror fill2attr fill2fs fill2fs_check scaleread.sh \ btrfs_crc32c_forged_name.py popdir.pl popattr.py \ diff --git a/src/fiemap-fault.c b/src/fiemap-fault.c new file mode 100644 index 0000000000..7326006805 --- /dev/null +++ b/src/fiemap-fault.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2024 Meta Platforms, Inc. All Rights Reserved. + */ + +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <linux/fs.h> +#include <linux/types.h> +#include <linux/fiemap.h> +#include <err.h> +#include <errno.h> +#include <fcntl.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> + +int prep_mmap_buffer(int fd, void **addr) +{ + struct stat st; + int ret; + + ret = fstat(fd, &st); + if (ret) + err(1, "failed to stat %d", fd); + + *addr = mmap(NULL, st.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); + if (*addr == MAP_FAILED) + err(1, "failed to mmap %d", fd); + + return st.st_size; +} + +int main(int argc, char *argv[]) +{ + struct fiemap *fiemap; + size_t sz, last = 0; + void *buf = NULL; + int ret, fd; + + if (argc != 2) + errx(1, "no in and out file name arguments given"); + + fd = open(argv[1], O_RDWR, 0666); + if (fd == -1) + err(1, "failed to open %s", argv[1]); + + sz = prep_mmap_buffer(fd, &buf); + + fiemap = (struct fiemap *)buf; + fiemap->fm_flags = 0; + fiemap->fm_extent_count = (sz - sizeof(struct fiemap)) / + sizeof(struct fiemap_extent); + + while (last < sz) { + int i; + + fiemap->fm_start = last; + fiemap->fm_length = sz - last; + + ret = ioctl(fd, FS_IOC_FIEMAP, (unsigned long)fiemap); + if (ret < 0) + err(1, "fiemap failed %d", errno); + for (i = 0; i < fiemap->fm_mapped_extents; i++) + last = fiemap->fm_extents[i].fe_logical + + fiemap->fm_extents[i].fe_length; + } + + munmap(buf, sz); + close(fd); + return 0; +} diff --git a/tests/generic/742 b/tests/generic/742 new file mode 100755 index 0000000000..43ebdbc63f --- /dev/null +++ b/tests/generic/742 @@ -0,0 +1,50 @@ +#! /bin/bash +# SPDX-License-Identifier: GPL-2.0 +# Copyright (c) 2024 Meta Platforms, Inc. All Rights Reserved. +# +# FS QA Test No. 742 +# +# 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 fiemap +[ $FSTYP == "btrfs" ] && \ + _fixed_by_kernel_commit b0ad381fa769 \ + "btrfs: fix deadlock with fiemap and extent locking" + +_cleanup() +{ + rm -f $dst + cd / + rm -r -f $tmp.* +} + +# real QA test starts here +_supported_fs generic +_require_test +_require_test_program "fiemap-fault" +_require_test_program "punch-alternating" +_require_xfs_io_command "fpunch" + +dst=$TEST_DIR/$seq/fiemap-fault + +mkdir -p $TEST_DIR/$seq + +echo "Silence is golden" + +# Generate a file with lots of extents +blksz=$(_get_file_block_size $TEST_DIR) +$XFS_IO_PROG -f -c "pwrite -q 0 $((blksz * 10000))" $dst +$here/src/punch-alternating $dst + +# Now run the reproducer +$here/src/fiemap-fault $dst + +# success, all done +status=$? +exit diff --git a/tests/generic/742.out b/tests/generic/742.out new file mode 100644 index 0000000000..ef4f23cde9 --- /dev/null +++ b/tests/generic/742.out @@ -0,0 +1,2 @@ +QA output created by 742 +Silence is golden |