[PULL,18/42] qcow2: cleanup qcow2_co_pwritev_compressed to avoid the recursion

Commit Message

Kevin Wolf Sept. 5, 2016, 6:13 p.m. UTC

From: Pavel Butsykin <[e-mail]>

Now that the function uses a vector instead of a buffer, there is no
need to use recursive code.

Signed-off-by: Pavel Butsykin <[e-mail]>
Reviewed-by: Stefan Hajnoczi <[e-mail]>
Signed-off-by: Denis V. Lunev <[e-mail]>
CC: Jeff Cody <[e-mail]>
CC: Markus Armbruster <[e-mail]>
CC: Eric Blake <[e-mail]>
CC: John Snow <[e-mail]>
CC: Stefan Hajnoczi <[e-mail]>
CC: Kevin Wolf <[e-mail]>
Signed-off-by: Kevin Wolf <[e-mail]>
---
 block/qcow2.c | 24 +++++++-----------------
 1 file changed, 7 insertions(+), 17 deletions(-)

Patch

diff --git a/block/qcow2.c b/block/qcow2.c
index 1cbaa8f..adf4514 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2554,27 +2554,17 @@  qcow2_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
         return bdrv_truncate(bs->file->bs, cluster_offset);
     }
 
+    buf = qemu_blockalign(bs, s->cluster_size);
     if (bytes != s->cluster_size) {
-        ret = -EINVAL;
-
-        /* Zero-pad last write if image size is not cluster aligned */
-        if (offset + bytes == bs->total_sectors << BDRV_SECTOR_BITS &&
-            bytes < s->cluster_size)
+        if (bytes > s->cluster_size ||
+            offset + bytes != bs->total_sectors << BDRV_SECTOR_BITS)
         {
-            uint8_t *pad_buf = qemu_blockalign(bs, s->cluster_size);
-            memset(pad_buf, 0, s->cluster_size);
-            qemu_iovec_to_buf(qiov, 0, pad_buf, s->cluster_size);
-            iov = (struct iovec) {
-                .iov_base   = pad_buf,
-                .iov_len    = s->cluster_size,
-            };
-            qemu_iovec_init_external(&hd_qiov, &iov, 1);
-            ret = qcow2_co_pwritev_compressed(bs, offset, bytes, &hd_qiov);
-            qemu_vfree(pad_buf);
+            qemu_vfree(buf);
+            return -EINVAL;
         }
-        return ret;
+        /* Zero-pad last write if image size is not cluster aligned */
+        memset(buf + bytes, 0, s->cluster_size - bytes);
     }
-    buf = qemu_blockalign(bs, s->cluster_size);
     qemu_iovec_to_buf(qiov, 0, buf, s->cluster_size);
 
     out_buf = g_malloc(s->cluster_size);