commit 485350497b7a9be3477d453fe0fdf380b8535303
author Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Fri Sep 03 13:28:01 2021 +0300
committer Eric Blake <eblake@redhat.com> Wed Sep 29 13:46:32 2021 -0500
tree 746449ba304be8a1a21cab9d8645e7084ac28428
parent e75abedab7e10043ed81b1cbc3033409aff0159e

block: use int64_t instead of uint64_t in copy_range driver handlers

We are generally moving to int64_t for both offset and bytes parameters
on all io paths.

Main motivation is realization of 64-bit write_zeroes operation for
fast zeroing large disk chunks, up to the whole disk.

We chose signed type, to be consistent with off_t (which is signed) and
with possibility for signed return type (where negative value means
error).

So, convert driver copy_range handlers parameters which are already
64bit to signed type.

Now let's consider all callers. Simple

  git grep '\->bdrv_co_copy_range'

shows the only caller:

  bdrv_co_copy_range_internal(), which does bdrv_check_request32(),
  so everything is OK.

Still, the functions may be called directly, not only by drv->...
Let's check:

git grep '\.bdrv_co_copy_range_\(from\|to\)\s*=' | \
awk '{print $4}' | sed 's/,//' | sed 's/&//' | sort | uniq | \
while read func; do git grep "$func(" | \
grep -v "$func(BlockDriverState"; done

shows no more callers. So, we are done.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20210903102807.27127-6-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

block/raw-format.c

diff --git a/block/raw-format.c b/block/raw-format.c
index d223298..3451378 100644
--- a/block/raw-format.c
+++ b/block/raw-format.c
@@ -532,16 +532,16 @@
 
 static int coroutine_fn raw_co_copy_range_from(BlockDriverState *bs,
                                                BdrvChild *src,
-                                               uint64_t src_offset,
+                                               int64_t src_offset,
                                                BdrvChild *dst,
-                                               uint64_t dst_offset,
-                                               uint64_t bytes,
+                                               int64_t dst_offset,
+                                               int64_t bytes,
                                                BdrvRequestFlags read_flags,
                                                BdrvRequestFlags write_flags)
 {
     int ret;
 
-    ret = raw_adjust_offset(bs, (int64_t *)&src_offset, bytes, false);
+    ret = raw_adjust_offset(bs, &src_offset, bytes, false);
     if (ret) {
         return ret;
     }
@@ -551,16 +551,16 @@
 
 static int coroutine_fn raw_co_copy_range_to(BlockDriverState *bs,
                                              BdrvChild *src,
-                                             uint64_t src_offset,
+                                             int64_t src_offset,
                                              BdrvChild *dst,
-                                             uint64_t dst_offset,
-                                             uint64_t bytes,
+                                             int64_t dst_offset,
+                                             int64_t bytes,
                                              BdrvRequestFlags read_flags,
                                              BdrvRequestFlags write_flags)
 {
     int ret;
 
-    ret = raw_adjust_offset(bs, (int64_t *)&dst_offset, bytes, true);
+    ret = raw_adjust_offset(bs, &dst_offset, bytes, true);
     if (ret) {
         return ret;
     }