Re: [LTP] [BUG] btrfs potential failure on 32 core LTP test (fallocate05)

[Petr Vorel <pvorel@suse.cz>]

> On 29/06/2021 19:20, Josef Bacik wrote:
> > On 6/29/21 1:00 PM, Krzysztof Kozlowski wrote:
> >> Dear BTRFS folks,

> >> I am hitting a potential regression of btrfs, visible only with
> >> fallocate05 test from LTP (Linux Test Project) only on 32+ core Azure
> >> instances (x86_64).

> >> Tested:
> >> v5.8 (Ubuntu with our stable patches): PASS
> >> v5.11 (Ubuntu with our stable patches): FAIL
> >> v5.13 mainline: FAIL

> >> PASS means test passes on all instances
> >> FAIL means test passes on other instance types (e.g. 4 or 16 core) but
> >> fails on 32 and 64 core instances (did not test higher),
> >> e.g.: Standard_F32s_v2, Standard_F64s_v2, Standard_D32s_v3,
> >> Standard_E32s_v3

> >> Reproduction steps:
> >> git clone https://github.com/linux-test-project/ltp.git
> >> cd ltp
> >> ./build.sh && make install -j8
> >> cd ../ltp-install
> >> sudo ./runltp -f syscalls -s fallocate05


> > This thing keeps trying to test ext2, how do I make it only test btrfs?  Thanks,

> It tests all available file systems, just wait till it gets to btrfs. I
> don't know how to limit it only to one file system.
In the future we can add environment variable to specify the only fs to be
tested. There is LTP_DEV_FS_TYPE, but that does not work when .all_filesystems
flag is enabled. Thus just patch the file:

Kind regards,
Petr

diff --git testcases/kernel/syscalls/fallocate/fallocate05.c testcases/kernel/syscalls/fallocate/fallocate05.c
index 55ec1aee4..7f5a3005a 100644
--- testcases/kernel/syscalls/fallocate/fallocate05.c
+++ testcases/kernel/syscalls/fallocate/fallocate05.c
@@ -149,7 +149,8 @@ static struct tst_test test = {
 	.mount_device = 1,
 	.dev_min_size = 512,
 	.mntpoint = MNTPOINT,
-	.all_filesystems = 1,
+	.needs_device = 1,
+	.dev_fs_type = "btrfs",
 	.setup = setup,
 	.cleanup = cleanup,
 	.test_all = run,