fsstress: bypass io_uring testing if io_uring_queue_init returns EPERM

I found the io_uring testing still fails as:
  io_uring_queue_init failed
even if kernel supports io_uring feature.

That because of the /proc/sys/kernel/io_uring_disabled isn't 0.

Different value means:
  0 All processes can create io_uring instances as normal.
  1 io_uring creation is disabled (io_uring_setup() will fail with
    -EPERM) for unprivileged processes not in the io_uring_group
    group. Existing io_uring instances can still be used.  See the
    documentation for io_uring_group for more information.
  2 io_uring creation is disabled for all processes. io_uring_setup()
    always fails with -EPERM. Existing io_uring instances can still
    be used.

So besides the CONFIG_IO_URING kernel config, there's another switch
can on or off the io_uring supporting. And the "2" or "1" might be
the default on some systems.

On this situation the io_uring_queue_init returns -EPERM, so I change
the fsstress to ignore io_uring testing if io_uring_queue_init returns
-ENOSYS or -EPERM. And print different verbose message for debug.

Signed-off-by: Zorro Lang <zlang@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>

diff --git a/ltp/fsstress.c b/ltp/fsstress.c
index 4fc50efb9bf18b113224858533b81c9968f372ed..9d2631f7f91b0faa121f2743b9dd327a00931984 100644 (file)
--- a/ltp/fsstress.c
+++ b/ltp/fsstress.c
@@ -762,7 +762,12 @@ int main(int argc, char **argv)
 #endif
 #ifdef URING
                        have_io_uring = true;
-                       /* If ENOSYS, just ignore uring, other errors are fatal. */
+                       /*
+                        * If ENOSYS, just ignore uring, due to kernel doesn't support it.
+                        * If EPERM, maybe due to sysctl kernel.io_uring_disabled isn't 0,
+                        *           or some selinux policies, etc.
+                        * Other errors are fatal.
+                        */
                        c = io_uring_queue_init(URING_ENTRIES, &ring, 0);
                        switch(c){
                        case 0:
@@ -770,9 +775,16 @@ int main(int argc, char **argv)
                                break;
                        case -ENOSYS:
                                have_io_uring = false;
+                               if (verbose)
+                                       printf("io_uring isn't supported by kernel\n");
+                               break;
+                       case -EPERM:
+                               have_io_uring = false;
+                               if (verbose)
+                                       printf("io_uring isn't allowed, check io_uring_disabled sysctl or selinux policy\n");
                                break;
                        default:
-                               fprintf(stderr, "io_uring_queue_init failed\n");
+                               fprintf(stderr, "io_uring_queue_init failed, errno=%d\n", -c);
                                exit(1);
                        }
 #endif