On 13.09.2013 10:26, Paolo Bonzini wrote:
Il 13/09/2013 10:04, Peter Lieven ha scritto:
On 06.09.2013 17:39, Stefan Hajnoczi wrote:
From: Paolo Bonzini <pbonz...@redhat.com>
Define the return value of get_block_status. Bits 0, 1, 2 and 9-62
are valid; bit 63 (the sign bit) is reserved for errors. Bits 3-8
are left for future extensions.
The return code is compatible with the old is_allocated API: if a driver
only returns 0 or 1 (aka BDRV_BLOCK_DATA) like is_allocated used to,
clients of is_allocated will not have any change in behavior. Still,
we will return more precise information in the next patches and the
new definition of bdrv_is_allocated is already prepared for this.
Reviewed-by: Eric Blake <ebl...@redhat.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefa...@redhat.com>
---
block.c | 10 ++++++++--
include/block/block.h | 26 ++++++++++++++++++++++++++
2 files changed, 34 insertions(+), 2 deletions(-)
diff --git a/block.c b/block.c
index a5bfe74..97406ec 100644
--- a/block.c
+++ b/block.c
@@ -3093,7 +3093,7 @@ static int64_t coroutine_fn
bdrv_co_get_block_status(BlockDriverState *bs,
if (!bs->drv->bdrv_co_get_block_status) {
*pnum = nb_sectors;
- return 1;
+ return BDRV_BLOCK_DATA;
}
return bs->drv->bdrv_co_get_block_status(bs, sector_num,
nb_sectors, pnum);
@@ -3143,7 +3143,13 @@ int64_t bdrv_get_block_status(BlockDriverState
*bs, int64_t sector_num,
int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t
sector_num,
int nb_sectors, int *pnum)
{
- return bdrv_get_block_status(bs, sector_num, nb_sectors, pnum);
+ int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors,
pnum);
+ if (ret < 0) {
sorry if I repeat myself.
isn't here a *pnum = 0 missing?
I think an earlier patch makes it unnecessary, because I'm checking the
return status of bdrv_get_block_status and bdrv_is_allocated. In any
case the right place to put it would be in bdrv_get_block_status.
Ok, then I think for safety it should be added here:
@@ -3104,13 +3151,14 @@ static int64_t coroutine_fn
bdrv_co_get_block_status(BlockDriverState *bs,
ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum);
if (ret < 0) {
+ *pnum = 0;
return ret;
}
because the new get_block_status api requires a ret < 0 if an error occurs. in
case of an error
someone will write sth like ret = -EINVAL in the block driver. this not
necessary implies *pnum = 0; the old
bdrv_is_allocated framework required a *pnum = 0 on error, but if someone (like
me for iscsi)
creates bdrv_get_block_status from scratch will not explicity do this.
Peter
