[Qemu-devel] [PATCH 04/11] vpc: make it thread-safe

Paolo Bonzini posted 11 patches 8 years, 8 months ago
There is a newer version of this series
[Qemu-devel] [PATCH 04/11] vpc: make it thread-safe
Posted by Paolo Bonzini 8 years, 8 months ago
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 block/vpc.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/block/vpc.c b/block/vpc.c
index ecfee77149..d61754d4d5 100644
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -496,12 +496,6 @@ static inline int64_t get_image_offset(BlockDriverState *bs, uint64_t offset,
     return block_offset;
 }
 
-static inline int64_t get_sector_offset(BlockDriverState *bs,
-                                        int64_t sector_num, bool write)
-{
-    return get_image_offset(bs, sector_num * BDRV_SECTOR_SIZE, write);
-}
-
 /*
  * Writes the footer to the end of the image file. This is needed when the
  * file grows as it overwrites the old footer
@@ -696,6 +690,7 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
     VHDFooter *footer = (VHDFooter*) s->footer_buf;
     int64_t start, offset;
     bool allocated;
+    int64_t ret;
     int n;
 
     if (be32_to_cpu(footer->type) == VHD_FIXED) {
@@ -705,10 +700,13 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
                (sector_num << BDRV_SECTOR_BITS);
     }
 
-    offset = get_sector_offset(bs, sector_num, 0);
+    qemu_co_mutex_lock(&s->lock);
+
+    offset = get_image_offset(bs, sector_num << BDRV_SECTOR_BITS, 0);
     start = offset;
     allocated = (offset != -1);
     *pnum = 0;
+    ret = 0;
 
     do {
         /* All sectors in a block are contiguous (without using the bitmap) */
@@ -723,15 +721,17 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
          * sectors since there is always a bitmap in between. */
         if (allocated) {
             *file = bs->file->bs;
-            return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;
+            ret = BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start;
+            break;
         }
         if (nb_sectors == 0) {
             break;
         }
-        offset = get_sector_offset(bs, sector_num, 0);
+        offset = get_image_offset(bs, sector_num << BDRV_SECTOR_BITS, 0);
     } while (offset == -1);
 
-    return 0;
+    qemu_co_mutex_unlock(&s->lock);
+    return ret;
 }
 
 /*
-- 
2.13.0



Re: [Qemu-devel] [PATCH 04/11] vpc: make it thread-safe
Posted by Eric Blake 8 years, 8 months ago
On 05/31/2017 04:43 AM, Paolo Bonzini wrote:
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  block/vpc.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
> 

> @@ -705,10 +700,13 @@ static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs,
>                 (sector_num << BDRV_SECTOR_BITS);
>      }
>  
> -    offset = get_sector_offset(bs, sector_num, 0);
> +    qemu_co_mutex_lock(&s->lock);
> +
> +    offset = get_image_offset(bs, sector_num << BDRV_SECTOR_BITS, 0);

s/0/false/

(Phooey - your code and my efforts to turn block_status into byte-based
code collide; I'll have to rebase again...)

>          if (nb_sectors == 0) {
>              break;
>          }
> -        offset = get_sector_offset(bs, sector_num, 0);
> +        offset = get_image_offset(bs, sector_num << BDRV_SECTOR_BITS, 0);

s/0/false/

With the correct parameter,
Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org