block: Add .bdrv_co_pdiscard() driver callback

There's enough drivers with a sector-based callback that it will
be easier to switch one at a time.  This patch adds a byte-based
callback, and then after all drivers are swapped, we'll drop the
sector-based callback.

[checkpatch doesn't like the space after coroutine_fn in
block_int.h, but it's consistent with the rest of the file]

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1468624988-423-10-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/block/io.c b/block/io.c
index 5c759fa..5ba0195 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2423,7 +2423,8 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset,
         return 0;
     }
 
-    if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_pdiscard) {
+    if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_co_pdiscard &&
+        !bs->drv->bdrv_aio_pdiscard) {
         return 0;
     }
 
@@ -2455,7 +2456,9 @@ int coroutine_fn bdrv_co_pdiscard(BlockDriverState *bs, int64_t offset,
         int ret;
         int num = MIN(count, max_pdiscard);
 
-        if (bs->drv->bdrv_co_discard) {
+        if (bs->drv->bdrv_co_pdiscard) {
+            ret = bs->drv->bdrv_co_pdiscard(bs, offset, num);
+        } else if (bs->drv->bdrv_co_discard) {
             ret = bs->drv->bdrv_co_discard(bs, offset >> BDRV_SECTOR_BITS,
                                            num >> BDRV_SECTOR_BITS);
         } else {