diff --git a/block/io.c b/block/io.c
index a4f9714230..7d30e61edc 100644
--- a/block/io.c
+++ b/block/io.c
@@ -960,7 +960,7 @@ int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
  * flags are passed through to bdrv_pwrite_zeroes (e.g. BDRV_REQ_MAY_UNMAP,
  * BDRV_REQ_FUA).
  *
- * Returns < 0 on error, 0 on success. For error codes see bdrv_write().
+ * Returns < 0 on error, 0 on success. For error codes see bdrv_pwrite().
  */
 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
 {
@@ -994,6 +994,7 @@ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
     }
 }
 
+/* return < 0 if error. See bdrv_pwrite() for the return codes */
 int bdrv_preadv(BdrvChild *child, int64_t offset, QEMUIOVector *qiov)
 {
     int ret;
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index d9650b9b6c..0457a6060d 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -2660,7 +2660,7 @@ fail:
  * - 0 if writing to this offset will not affect the mentioned metadata
  * - a positive QCow2MetadataOverlap value indicating one overlapping section
  * - a negative value (-errno) indicating an error while performing a check,
- *   e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2
+ *   e.g. when bdrv_pread failed on QCOW2_OL_INACTIVE_L2
  */
 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
                                  int64_t size)
diff --git a/block/vvfat.c b/block/vvfat.c
index ab800c4887..6d5c090dec 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -2148,7 +2148,7 @@ DLOG(checkpoint());
      * - get modified FAT
      * - compare the two FATs (TODO)
      * - get buffer for marking used clusters
-     * - recurse direntries from root (using bs->bdrv_read to make
+     * - recurse direntries from root (using bs->bdrv_pread to make
      *    sure to get the new data)
      *   - check that the FAT agrees with the size
      *   - count the number of clusters occupied by this directory and
@@ -2913,9 +2913,9 @@ static int handle_deletes(BDRVVVFATState* s)
 /*
  * synchronize mapping with new state:
  *
- * - copy FAT (with bdrv_read)
+ * - copy FAT (with bdrv_pread)
  * - mark all filenames corresponding to mappings as deleted
- * - recurse direntries from root (using bs->bdrv_read)
+ * - recurse direntries from root (using bs->bdrv_pread)
  * - delete files corresponding to mappings marked as deleted
  */
 static int do_commit(BDRVVVFATState* s)
@@ -2935,10 +2935,10 @@ static int do_commit(BDRVVVFATState* s)
         return ret;
     }
 
-    /* copy FAT (with bdrv_read) */
+    /* copy FAT (with bdrv_pread) */
     memcpy(s->fat.pointer, s->fat2, 0x200 * s->sectors_per_fat);
 
-    /* recurse direntries from root (using bs->bdrv_read) */
+    /* recurse direntries from root (using bs->bdrv_pread) */
     ret = commit_direntries(s, 0, -1);
     if (ret) {
         fprintf(stderr, "Fatal: error while committing (%d)\n", ret);
diff --git a/tests/qemu-iotests/001 b/tests/qemu-iotests/001
index d87a535c33..696726e45f 100755
--- a/tests/qemu-iotests/001
+++ b/tests/qemu-iotests/001
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# Test simple read/write using plain bdrv_read/bdrv_write
+# Test simple read/write using plain bdrv_pread/bdrv_pwrite
 #
 # Copyright (C) 2009 Red Hat, Inc.
 #
diff --git a/tests/qemu-iotests/052 b/tests/qemu-iotests/052
index 45a140910d..8d5c10601f 100755
--- a/tests/qemu-iotests/052
+++ b/tests/qemu-iotests/052
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# Test bdrv_read/bdrv_write using BDRV_O_SNAPSHOT
+# Test bdrv_pread/bdrv_pwrite using BDRV_O_SNAPSHOT
 #
 # Copyright (C) 2013 Red Hat, Inc.
 #
diff --git a/tests/qemu-iotests/134 b/tests/qemu-iotests/134
index 5f0fb86211..5162d21662 100755
--- a/tests/qemu-iotests/134
+++ b/tests/qemu-iotests/134
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# Test encrypted read/write using plain bdrv_read/bdrv_write
+# Test encrypted read/write using plain bdrv_pread/bdrv_pwrite
 #
 # Copyright (C) 2015 Red Hat, Inc.
 #
diff --git a/tests/qemu-iotests/188 b/tests/qemu-iotests/188
index afca44df54..09b9b6083a 100755
--- a/tests/qemu-iotests/188
+++ b/tests/qemu-iotests/188
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# Test encrypted read/write using plain bdrv_read/bdrv_write
+# Test encrypted read/write using plain bdrv_pread/bdrv_pwrite
 #
 # Copyright (C) 2017 Red Hat, Inc.
 #