vpc: make it thread-safe

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20170629132749.997-5-pbonzini@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
This commit is contained in:
Paolo Bonzini 2017-06-29 15:27:42 +02:00 committed by Fam Zheng
parent 1e88663979
commit 778b087e51

View File

@ -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, false);
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, false);
} while (offset == -1);
return 0;
qemu_co_mutex_unlock(&s->lock);
return ret;
}
/*