[PATCH 1/3] According to the manual of io_uring_queue_init, it doesn't set errno but return the -errno on failure. So we should check the return value of io_uring_queue_init, to make sure if the io_uring is supported by kernel. We've left this problem in xfstests/ltp/fsstress.c long time. V2 replace "if()...else..." with "switch()..." [PATCH 2/3] And besides kernel build without CONFIG_IO_URING, a system can disable the io_uring supporting manually, by set sysctl kernel.io_uring_disabled=2. The former cause io_uring_queue_init return ENOSYS, but the latter will return EPERM. So I let fsstress to deal with both situations. V2 follows the "switch()..." format of patch 1/3 [PATCH 3/3] This patch is re-written totally, and no any RVB. This v2 decides to notrun if sysctl kernel.io_uring_disabled is 2. Then change README to clarify how to make sure io_uring testing to be run. Thanks, Zorro
