[Qemu-devel] [RFC PATCH 2/4] block/raw-posix: implement bdrv_zero_init

[Hu Tao]

Implement bdrv_zero_init using posix_fallocate.

Signed-off-by: Hu Tao <address@hidden>
---
 block/raw-posix.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index f6d48bb..8798599 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -1190,6 +1190,18 @@ static int64_t coroutine_fn 
raw_co_get_block_status(BlockDriverState *bs,
     return ret;
 }
 
+static int raw_zero_init(BlockDriverState *bs, int64_t offset, int64_t length)
+{
+    BDRVRawState *s = bs->opaque;
+    int64_t len = bdrv_getlength(bs);
+
+    if (offset + length < 0 || offset + length > len) {
+        return -1;
+    }
+
+    return posix_fallocate(s->fd, offset, length);
+}
+
 static coroutine_fn BlockDriverAIOCB *raw_aio_discard(BlockDriverState *bs,
     int64_t sector_num, int nb_sectors,
     BlockDriverCompletionFunc *cb, void *opaque)
@@ -1222,6 +1234,7 @@ static BlockDriver bdrv_file = {
     .bdrv_close = raw_close,
     .bdrv_create = raw_create,
     .bdrv_has_zero_init = bdrv_has_zero_init_1,
+    .bdrv_zero_init = raw_zero_init,
     .bdrv_co_get_block_status = raw_co_get_block_status,
 
     .bdrv_aio_readv = raw_aio_readv,
-- 
1.8.3.1