This patchset tries to add new IO_URING test into fsstress [1/4] and fsx [4/4]. And then do some changes and bug fix by the way [2/4 and 3/4]. fsstress and fsx are important tools in xfstests to do filesystem I/Os test, lots of test cases use it. So add IO_URING operation into fsstress and fsx will help to cover IO_URING test from fs side. I'm not an IO_URING expert, so cc io-uring@ list, please feel free to tell me if you find something wrong or have any suggestions to improve the test. Thanks, Zorro
