Re: [Qemu-block] [PATCH 2/2] block: add default implementations for bdrv_co_get_block_status()

[Stefan Hajnoczi]

On Wed, Jun 28, 2017 at 01:46:16AM +0300, Manos Pitsidianakis wrote:
> bdrv_co_get_block_status_from_file() and
> bdrv_co_get_block_status_from_backing() set *file to bs->file and
> bs->backing respectively, so that bdrv_co_get_block_status() can recurse
> to them. Future block drivers won't have to duplicate code to implement
> this.
> 
> Signed-off-by: Manos Pitsidianakis 
> ---
>  block/blkdebug.c  | 12 +---
>  block/commit.c| 12 +---
>  block/io.c| 24 
>  block/mirror.c| 12 +---
>  include/block/block_int.h | 16 
>  5 files changed, 43 insertions(+), 33 deletions(-)

Reviewed-by: Stefan Hajnoczi 


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[Qemu-block] [PATCH 2/2] block: add default implementations for bdrv_co_get_block_status()

[Manos Pitsidianakis]

bdrv_co_get_block_status_from_file() and
bdrv_co_get_block_status_from_backing() set *file to bs->file and
bs->backing respectively, so that bdrv_co_get_block_status() can recurse
to them. Future block drivers won't have to duplicate code to implement
this.

Signed-off-by: Manos Pitsidianakis 
---
 block/blkdebug.c  | 12 +---
 block/commit.c| 12 +---
 block/io.c| 24 
 block/mirror.c| 12 +---
 include/block/block_int.h | 16 
 5 files changed, 43 insertions(+), 33 deletions(-)

diff --git a/block/blkdebug.c b/block/blkdebug.c
index b25856c4..f1539db6 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -641,16 +641,6 @@ static int coroutine_fn 
blkdebug_co_pdiscard(BlockDriverState *bs,
 return bdrv_co_pdiscard(bs->file->bs, offset, bytes);
 }
 
-static int64_t coroutine_fn blkdebug_co_get_block_status(
-BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum,
-BlockDriverState **file)
-{
-*pnum = nb_sectors;
-*file = bs->file->bs;
-return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
-(sector_num << BDRV_SECTOR_BITS);
-}
-
 static void blkdebug_close(BlockDriverState *bs)
 {
 BDRVBlkdebugState *s = bs->opaque;
@@ -925,7 +915,7 @@ static BlockDriver bdrv_blkdebug = {
 .bdrv_co_flush_to_disk  = blkdebug_co_flush,
 .bdrv_co_pwrite_zeroes  = blkdebug_co_pwrite_zeroes,
 .bdrv_co_pdiscard   = blkdebug_co_pdiscard,
-.bdrv_co_get_block_status = blkdebug_co_get_block_status,
+.bdrv_co_get_block_status = bdrv_co_get_block_status_from_file,
 
 .bdrv_debug_event   = blkdebug_debug_event,
 .bdrv_debug_breakpoint  = blkdebug_debug_breakpoint,
diff --git a/block/commit.c b/block/commit.c
index 524bd549..5b04f832 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -247,16 +247,6 @@ static int coroutine_fn 
bdrv_commit_top_preadv(BlockDriverState *bs,
 return bdrv_co_preadv(bs->backing, offset, bytes, qiov, flags);
 }
 
-static int64_t coroutine_fn bdrv_commit_top_get_block_status(
-BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum,
-BlockDriverState **file)
-{
-*pnum = nb_sectors;
-*file = bs->backing->bs;
-return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
-   (sector_num << BDRV_SECTOR_BITS);
-}
-
 static void bdrv_commit_top_refresh_filename(BlockDriverState *bs, QDict *opts)
 {
 bdrv_refresh_filename(bs->backing->bs);
@@ -282,7 +272,7 @@ static void bdrv_commit_top_child_perm(BlockDriverState 
*bs, BdrvChild *c,
 static BlockDriver bdrv_commit_top = {
 .format_name= "commit_top",
 .bdrv_co_preadv = bdrv_commit_top_preadv,
-.bdrv_co_get_block_status   = bdrv_commit_top_get_block_status,
+.bdrv_co_get_block_status   = bdrv_co_get_block_status_from_backing,
 .bdrv_refresh_filename  = bdrv_commit_top_refresh_filename,
 .bdrv_close = bdrv_commit_top_close,
 .bdrv_child_perm= bdrv_commit_top_child_perm,
diff --git a/block/io.c b/block/io.c
index c1b73226..aec520b4 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1706,6 +1706,30 @@ typedef struct BdrvCoGetBlockStatusData {
 bool done;
 } BdrvCoGetBlockStatusData;
 
+int64_t coroutine_fn bdrv_co_get_block_status_from_file(BlockDriverState *bs,
+ int64_t sector_num,
+ int nb_sectors, int *pnum,
+ BlockDriverState **file)
+{
+assert(bs->file && bs->file->bs);
+*pnum = nb_sectors;
+*file = bs->file->bs;
+return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
+   (sector_num << BDRV_SECTOR_BITS);
+}
+
+int64_t coroutine_fn bdrv_co_get_block_status_from_backing(BlockDriverState 
*bs,
+ int64_t sector_num,
+ int nb_sectors, int *pnum,
+ BlockDriverState **file)
+{
+assert(bs->backing && bs->backing->bs);
+*pnum = nb_sectors;
+*file = bs->backing->bs;
+return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID |
+   (sector_num << BDRV_SECTOR_BITS);
+}
+
 /*
  * Returns the allocation status of the specified sectors.
  * Drivers not implementing the functionality are assumed to not support
diff --git a/block/mirror.c b/block/mirror.c
index 61a862dc..e8bf5f40 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -1052,16 +1052,6 @@ static int coroutine_fn 
bdrv_mirror_top_flush(BlockDriverState *bs)
 return bdrv_co_flush(bs->backing->bs);
 }
 
-static int64_t coroutine_fn bdrv_mirror_top_get_block_status(
-BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum,
-BlockDriverState **file)
-{
-*pnum = nb_sectors;
-*file = bs->backing->bs;
-return