[Qemu-devel] [PATCH] block: drop aio_multiwrite in BlockDriver

[Paolo Bonzini]

These were never used.

Signed-off-by: Paolo Bonzini <address@hidden>
---
 block.c     |   23 ++-------------------
 block_int.h |    6 ------
 2 files changed, 3 insertions(+), 26 deletions(-)

diff --git a/block.c b/block.c
index ae297bb..b395f7b 100644
--- a/block.c
+++ b/block.c
@@ -2767,7 +2793,6 @@ typedef struct MultiwriteCB {
         BlockDriverCompletionFunc *cb;
         void *opaque;
         QEMUIOVector *free_qiov;
-        void *free_buf;
     } callbacks[];
 } MultiwriteCB;
 
@@ -2781,7 +2806,6 @@ static void multiwrite_user_cb(MultiwriteCB *mcb)
             qemu_iovec_destroy(mcb->callbacks[i].free_qiov);
         }
         g_free(mcb->callbacks[i].free_qiov);
-        qemu_vfree(mcb->callbacks[i].free_buf);
     }
 }
 
@@ -2838,20 +2862,11 @@ static int multiwrite_merge(BlockDriverState *bs, 
BlockRequest *reqs,
         int merge = 0;
         int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
 
-        // This handles the cases that are valid for all block drivers, namely
-        // exactly sequential writes and overlapping writes.
+        // Handle exactly sequential writes and overlapping writes.
         if (reqs[i].sector <= oldreq_last) {
             merge = 1;
         }
 
-        // The block driver may decide that it makes sense to combine requests
-        // even if there is a gap of some sectors between them. In this case,
-        // the gap is filled with zeros (therefore only applicable for yet
-        // unused space in format like qcow2).
-        if (!merge && bs->drv->bdrv_merge_requests) {
-            merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
-        }
-
         if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
             merge = 0;
         }
@@ -2868,14 +2883,8 @@ static int multiwrite_merge(BlockDriverState *bs, 
BlockRequest *reqs,
             size = (reqs[i].sector - reqs[outidx].sector) << 9;
             qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
 
-            // We might need to add some zeros between the two requests
-            if (reqs[i].sector > oldreq_last) {
-                size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
-                uint8_t *buf = qemu_blockalign(bs, zero_bytes);
-                memset(buf, 0, zero_bytes);
-                qemu_iovec_add(qiov, buf, zero_bytes);
-                mcb->callbacks[i].free_buf = buf;
-            }
+            // We should need to add any zeros between the two requests
+            assert (reqs[i].sector <= oldreq_last);
 
             // Add the second request
             qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
diff --git a/block_int.h b/block_int.h
index 7946cf6..3eeca58 100644
--- a/block_int.h
+++ b/block_int.h
@@ -162,12 +162,6 @@ struct BlockDriver {
      */
     int coroutine_fn (*bdrv_co_flush_to_os)(BlockDriverState *bs);
 
-    int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,
-        int num_reqs);
-    int (*bdrv_merge_requests)(BlockDriverState *bs, BlockRequest* a,
-        BlockRequest *b);
-
-
     const char *protocol_name;
     int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
     int64_t (*bdrv_getlength)(BlockDriverState *bs);
-- 
1.7.7.6