block: Convert bdrv_aio_discard() to byte-based

Another step towards byte-based interfaces everywhere.  Replace
the sector-based bdrv_aio_discard() with a new byte-based
bdrv_aio_pdiscard(), which silently ignores any unaligned head
or tail.  Driver callbacks will be converted in followup patches.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-id: 1468624988-423-5-git-send-email-eblake@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 7 insertions, 8 deletions

diff --git a/block/io.c b/block/io.c
index 85953bb..58fdac5 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2193,7 +2193,7 @@ BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
     return &acb->common;
 }
 
-static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
+static void coroutine_fn bdrv_aio_pdiscard_co_entry(void *opaque)
 {
     BlockAIOCBCoroutine *acb = opaque;
     BlockDriverState *bs = acb->common.bs;
@@ -2202,21 +2202,20 @@ static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
     bdrv_co_complete(acb);
 }
 
-BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors,
-        BlockCompletionFunc *cb, void *opaque)
+BlockAIOCB *bdrv_aio_pdiscard(BlockDriverState *bs, int64_t offset, int count,
+                              BlockCompletionFunc *cb, void *opaque)
 {
     Coroutine *co;
     BlockAIOCBCoroutine *acb;
 
-    trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);
+    trace_bdrv_aio_pdiscard(bs, offset, count, opaque);
 
     acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
     acb->need_bh = true;
     acb->req.error = -EINPROGRESS;
-    acb->req.offset = sector_num << BDRV_SECTOR_BITS;
-    acb->req.bytes = nb_sectors << BDRV_SECTOR_BITS;
-    co = qemu_coroutine_create(bdrv_aio_discard_co_entry, acb);
+    acb->req.offset = offset;
+    acb->req.bytes = count;
+    co = qemu_coroutine_create(bdrv_aio_pdiscard_co_entry, acb);
     qemu_coroutine_enter(co);
 
     bdrv_co_maybe_schedule_bh(acb);