Patchwork [11/12] block/get_block_status: avoid redundant callouts on raw devices

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Submitter Peter Lieven
Date Sept. 13, 2013, 10:25 a.m.
Message ID <1379067909-22984-12-git-send-email-pl@kamp.de>
Download mbox | patch
Permalink /patch/274717/
State New
Headers show

Comments

Peter Lieven - Sept. 13, 2013, 10:25 a.m.
if a raw device like an iscsi target or host device is used
the current implementation makes a second call out to get
the block status of bs->file. however, the raw driver already
has called bdrv_get_block_status on bs->file.

Signed-off-by: Peter Lieven <pl@kamp.de>
---
 block.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
Eric Blake - Sept. 13, 2013, 6:28 p.m.
On 09/13/2013 04:25 AM, Peter Lieven wrote:
> if a raw device like an iscsi target or host device is used
> the current implementation makes a second call out to get
> the block status of bs->file. however, the raw driver already
> has called bdrv_get_block_status on bs->file.
> 
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

> 
> diff --git a/block.c b/block.c
> index cf9db62..282943b 100644
> --- a/block.c
> +++ b/block.c
> @@ -3167,7 +3167,8 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
>  
>      if (bs->file &&
>          (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
> -        (ret & BDRV_BLOCK_OFFSET_VALID)) {
> +        (ret & BDRV_BLOCK_OFFSET_VALID) &&
> +        strcmp(bs->drv->format_name, "raw")) {
>          ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
>                                          *pnum, pnum);
>          if (ret2 >= 0) {
>

Patch

diff --git a/block.c b/block.c
index cf9db62..282943b 100644
--- a/block.c
+++ b/block.c
@@ -3167,7 +3167,8 @@  static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
 
     if (bs->file &&
         (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
-        (ret & BDRV_BLOCK_OFFSET_VALID)) {
+        (ret & BDRV_BLOCK_OFFSET_VALID) &&
+        strcmp(bs->drv->format_name, "raw")) {
         ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS,
                                         *pnum, pnum);
         if (ret2 >= 0) {