Merge branch 'condvar'

[zfs.git] / module / zfs / zio.c

diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index 6333c78..ace72a0 100644 (file)
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -2432,19 +2432,25 @@ zio_vdev_io_start(zio_t *zio)
 
        align = 1ULL << vd->vdev_top->vdev_ashift;
 
-       if (P2PHASE(zio->io_size, align) != 0) {
+       /*
+        * On Linux, we don't care about read alignment. The backing block
+        * device driver will take care of that for us.
+        * The only exception is raidz, which needs a full block for parity.
+        */
+       if (P2PHASE(zio->io_size, align) != 0 &&
+           (zio->io_type != ZIO_TYPE_READ ||
+            vd->vdev_ops == &vdev_raidz_ops)) {
                uint64_t asize = P2ROUNDUP(zio->io_size, align);
                char *abuf = zio_buf_alloc(asize);
-               ASSERT(vd == vd->vdev_top);
                if (zio->io_type == ZIO_TYPE_WRITE) {
                        bcopy(zio->io_data, abuf, zio->io_size);
                        bzero(abuf + zio->io_size, asize - zio->io_size);
                }
                zio_push_transform(zio, abuf, asize, asize, zio_subblock);
+               ASSERT(P2PHASE(zio->io_size, align) == 0);
        }
 
        ASSERT(P2PHASE(zio->io_offset, align) == 0);
-       ASSERT(P2PHASE(zio->io_size, align) == 0);
        VERIFY(zio->io_type != ZIO_TYPE_WRITE || spa_writeable(spa));
 
        /*