As the fsx.c source code says: int fallocate_calls = 1; /* -F flag disables */ int allocsp_calls = 1; /* -F flag disables */ The allocsp_calls and fallocate_calls should be disabled, if the -F option is specified. But current fsx forgets to disable allocsp_calls as is documented. Signed-off-by: Zorro Lang <zlang@xxxxxxxxxx> --- Hi Darrick, Please help to take a look. I'm not sure if you'd like to disable allocsp_calls by -F flag, or just copied that line then forgot to change the F to another ? Thanks, Zorro ltp/fsx.c | 1 + 1 file changed, 1 insertion(+) diff --git a/ltp/fsx.c b/ltp/fsx.c index 520e53a2..3ee37fe8 100644 --- a/ltp/fsx.c +++ b/ltp/fsx.c @@ -2835,6 +2835,7 @@ main(int argc, char **argv) break; case 'F': fallocate_calls = 0; + allocsp_calls = 0; break; case 'K': keep_size_calls = 0; -- 2.31.1