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-rw-r--r--block.c23
1 files changed, 3 insertions, 20 deletions
diff --git a/block.c b/block.c
index 1150437b70..f23eccccd6 100644
--- a/block.c
+++ b/block.c
@@ -2791,7 +2791,6 @@ typedef struct MultiwriteCB {
BlockDriverCompletionFunc *cb;
void *opaque;
QEMUIOVector *free_qiov;
- void *free_buf;
} callbacks[];
} MultiwriteCB;
@@ -2805,7 +2804,6 @@ 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);
}
}
@@ -2862,20 +2860,11 @@ 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;
}
@@ -2891,14 +2880,8 @@ 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);