vdev_disk: reorganise vdev_disk_io_start

Light reshuffle to make it a bit more linear to read and get rid of a
bunch of args that aren't needed in all cases.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: Wasabi Technology, Inc.
Closes #15533
Closes #15588

diff --git a/module/os/linux/zfs/vdev_disk.c b/module/os/linux/zfs/vdev_disk.c
index 957619b87afd78339e122aeb93fd7f41930f4106..51e7cef2fc783b16018ac2f6eb8c9925cbd1b3b6 100644 (file)
--- a/module/os/linux/zfs/vdev_disk.c
+++ b/module/os/linux/zfs/vdev_disk.c
@@ -720,9 +720,16 @@ vdev_classic_bio_max_segs(zio_t *zio, int bio_size, uint64_t abd_offset)
 }
 
 static int
-vdev_classic_physio(struct block_device *bdev, zio_t *zio,
-    size_t io_size, uint64_t io_offset, int rw, int flags)
+vdev_classic_physio(zio_t *zio)
 {
+       vdev_t *v = zio->io_vd;
+       vdev_disk_t *vd = v->vdev_tsd;
+       struct block_device *bdev = BDH_BDEV(vd->vd_bdh);
+       size_t io_size = zio->io_size;
+       uint64_t io_offset = zio->io_offset;
+       int rw = zio->io_type == ZIO_TYPE_READ ? READ : WRITE;
+       int flags = 0;
+
        dio_request_t *dr;
        uint64_t abd_offset;
        uint64_t bio_offset;
@@ -944,7 +951,7 @@ vdev_disk_io_start(zio_t *zio)
 {
        vdev_t *v = zio->io_vd;
        vdev_disk_t *vd = v->vdev_tsd;
-       int rw, error;
+       int error;
 
        /*
         * If the vdev is closed, it's likely in the REMOVED or FAULTED state.
@@ -1007,13 +1014,6 @@ vdev_disk_io_start(zio_t *zio)
                rw_exit(&vd->vd_lock);
                zio_execute(zio);
                return;
-       case ZIO_TYPE_WRITE:
-               rw = WRITE;
-               break;
-
-       case ZIO_TYPE_READ:
-               rw = READ;
-               break;
 
        case ZIO_TYPE_TRIM:
                zio->io_error = vdev_disk_io_trim(zio);
@@ -1026,23 +1026,34 @@ vdev_disk_io_start(zio_t *zio)
 #endif
                return;
 
-       default:
+       case ZIO_TYPE_READ:
+       case ZIO_TYPE_WRITE:
+               zio->io_target_timestamp = zio_handle_io_delay(zio);
+               error = vdev_classic_physio(zio);
                rw_exit(&vd->vd_lock);
-               zio->io_error = SET_ERROR(ENOTSUP);
-               zio_interrupt(zio);
+               if (error) {
+                       zio->io_error = error;
+                       zio_interrupt(zio);
+               }
                return;
-       }
 
-       zio->io_target_timestamp = zio_handle_io_delay(zio);
-       error = vdev_classic_physio(BDH_BDEV(vd->vd_bdh), zio,
-           zio->io_size, zio->io_offset, rw, 0);
-       rw_exit(&vd->vd_lock);
+       default:
+               /*
+                * Getting here means our parent vdev has made a very strange
+                * request of us, and shouldn't happen. Assert here to force a
+                * crash in dev builds, but in production return the IO
+                * unhandled. The pool will likely suspend anyway but that's
+                * nicer than crashing the kernel.
+                */
+               ASSERT3S(zio->io_type, ==, -1);
 
-       if (error) {
-               zio->io_error = error;
+               rw_exit(&vd->vd_lock);
+               zio->io_error = SET_ERROR(ENOTSUP);
                zio_interrupt(zio);
                return;
        }
+
+       __builtin_unreachable();
 }
 
 static void