On Wed, Mar 13, 2024 at 11:48:51PM +0800, Zorro Lang wrote: > On Mon, Feb 12, 2024 at 11:41:14AM -0500, Josef Bacik wrote: > > 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> > > --- > > v1->v2: > > - Add the fiemap group to the test. > > - Actually include the reproducer helper program. > > Looks like this patch is missed (except the author changed the patch subject:), > correct me if I'm wrong. The last review point hoped to add "src/fiemap-fault" > to .gitignore. > > > > > src/Makefile | 2 +- > > src/fiemap-fault.c | 73 +++++++++++++++++++++++++++++++++++++++++++ > > tests/generic/740 | 41 ++++++++++++++++++++++++ > > tests/generic/740.out | 2 ++ > > 4 files changed, 117 insertions(+), 1 deletion(-) > > create mode 100644 src/fiemap-fault.c > > create mode 100644 tests/generic/740 > > create mode 100644 tests/generic/740.out > > > > [snip] > > > diff --git a/tests/generic/740 b/tests/generic/740 > > new file mode 100644 > > index 00000000..30ace1dd > > --- /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 fiemap > > +[ $FSTYP == "btrfs" ] && \ > > + _fixed_by_kernel_commit xxxxxxxxxxxx \ > > This commit id is "b0ad381fa769" now. > > > + "btrfs: fix deadlock with fiemap and extent locking" > > + > > +# real QA test starts here > > +_supported_fs generic > > +_require_test > > +_require_odirect > > +_require_test_program fiemap-fault > > +dst=$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 > > _require_sparse_files ? > This is the only comment I didn't incorporate, I'm not looking for sparse files, I'm just looking for a lot of extents. If smb fills in the holes I suppose this will only be a problem if it fills them in contiguously, but it'll just create a 4gib file instead of a 2gib file. Thanks, Josef
