Re: [Qemu-devel] [PATCH 1/2] qcow2: Prefer byte-based calls into bs->file

[Alberto Garcia]

On Tue 20 Feb 2018 11:24:58 PM CET, Eric Blake wrote:
> diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
> index d46b69d7f34..3fefeb3dc50 100644
> --- a/block/qcow2-refcount.c
> +++ b/block/qcow2-refcount.c
> @@ -2310,8 +2310,8 @@ write_refblocks:
>  on_disk_refblock = (void *)((char *) *refcount_table +
>  refblock_index * s->cluster_size);
>
> -ret = bdrv_write(bs->file, refblock_offset / BDRV_SECTOR_SIZE,
> - on_disk_refblock, s->cluster_sectors);
> +ret = bdrv_pwrite(bs->file, refblock_offset,
> + on_disk_refblock, s->cluster_size);

It looks like the second line is not properly indented. I think you can
also move on_disk_refblock to the previous line.

Otherwise the patch looks good.

Reviewed-by: Alberto Garcia 

Berto

[Qemu-devel] [PATCH 1/2] qcow2: Prefer byte-based calls into bs->file

[Eric Blake]

We had only three sector-based stragglers left; convert them to use
our preferred byte-based accesses.

Signed-off-by: Eric Blake 
---
 block/qcow2-cluster.c  | 5 ++---
 block/qcow2-refcount.c | 6 +++---
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index e406b0f3b9e..85be7d5e340 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1615,13 +1615,12 @@ int qcow2_decompress_cluster(BlockDriverState *bs, 
uint64_t cluster_offset)
 }

 BLKDBG_EVENT(bs->file, BLKDBG_READ_COMPRESSED);
-ret = bdrv_read(bs->file, coffset >> 9, s->cluster_data,
-nb_csectors);
+ret = bdrv_pread(bs->file, coffset, s->cluster_data, csize);
 if (ret < 0) {
 return ret;
 }
 if (decompress_buffer(s->cluster_cache, s->cluster_size,
-  s->cluster_data + sector_offset, csize) < 0) {
+  s->cluster_data, csize) < 0) {
 return -EIO;
 }
 s->cluster_cache_offset = coffset;
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index d46b69d7f34..3fefeb3dc50 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -2310,8 +2310,8 @@ write_refblocks:
 on_disk_refblock = (void *)((char *) *refcount_table +
 refblock_index * s->cluster_size);

-ret = bdrv_write(bs->file, refblock_offset / BDRV_SECTOR_SIZE,
- on_disk_refblock, s->cluster_sectors);
+ret = bdrv_pwrite(bs->file, refblock_offset,
+ on_disk_refblock, s->cluster_size);
 if (ret < 0) {
 fprintf(stderr, "ERROR writing refblock: %s\n", strerror(-ret));
 goto fail;
@@ -2533,7 +2533,7 @@ fail:
  * - 0 if writing to this offset will not affect the mentioned metadata
  * - a positive QCow2MetadataOverlap value indicating one overlapping section
  * - a negative value (-errno) indicating an error while performing a check,
- *   e.g. when bdrv_read failed on QCOW2_OL_INACTIVE_L2
+ *   e.g. when bdrv_pread failed on QCOW2_OL_INACTIVE_L2
  */
 int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
  int64_t size)
-- 
2.14.3