block: add .bdrv_co_is_allocated()

This patch adds the .bdrv_co_is_allocated() interface which is identical
to .bdrv_is_allocated() but runs in coroutine context.  Running in
coroutine context implies that other coroutines might be performing I/O
at the same time.   Therefore it must be safe to run while the following
BlockDriver functions are in-flight:

    .bdrv_co_readv()
    .bdrv_co_writev()
    .bdrv_co_flush()
    .bdrv_co_is_allocated()

The new .bdrv_co_is_allocated() interface is useful because it can be
used when a VM is running, whereas .bdrv_is_allocated() is a synchronous
interface that does not cope with parallel requests.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2011-11-14 12:44:19 +00:00 committed by Kevin Wolf
parent 05c4af54c6
commit 376ae3f1cb
2 changed files with 39 additions and 0 deletions

View file

@ -103,6 +103,8 @@ struct BlockDriver {
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
int coroutine_fn (*bdrv_co_discard)(BlockDriverState *bs,
int64_t sector_num, int nb_sectors);
int coroutine_fn (*bdrv_co_is_allocated)(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, int *pnum);
/*
* Invalidate any cached meta-data.