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qed: convert to .bdrv_co_is_allocated() 

The bdrv_qed_is_allocated() function is a synchronous wrapper around
qed_find_cluster(), which performs the cluster lookup.  In order to
convert the synchronous function to a coroutine function we yield
instead of using qemu_aio_wait().  Note that QED's cache is already safe
for parallel requests so no locking is needed.

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 12:44:20 +00:00 committed by Kevin Wolf
parent 376ae3f1cb
commit b7d5a5b8ae
1 changed files with 11 additions and 4 deletions
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15
block/qed.c
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@ -661,6 +661,7 @@ static int bdrv_qed_create(const char *filename, QEMUOptionParameter *options)
}
typedef struct {
Coroutine *co;
int is_allocated;
int *pnum;
} QEDIsAllocatedCB;
@ -670,10 +671,14 @@ static void qed_is_allocated_cb(void *opaque, int ret, uint64_t offset, size_t l
QEDIsAllocatedCB *cb = opaque;
*cb->pnum = len / BDRV_SECTOR_SIZE;
cb->is_allocated = (ret == QED_CLUSTER_FOUND || ret == QED_CLUSTER_ZERO);
if (cb->co) {
qemu_coroutine_enter(cb->co, NULL);
}
}
static int bdrv_qed_is_allocated(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum)
static int coroutine_fn bdrv_qed_co_is_allocated(BlockDriverState *bs,
int64_t sector_num,
int nb_sectors, int *pnum)
{
BDRVQEDState *s = bs->opaque;
uint64_t pos = (uint64_t)sector_num * BDRV_SECTOR_SIZE;
@ -686,8 +691,10 @@ static int bdrv_qed_is_allocated(BlockDriverState *bs, int64_t sector_num,
qed_find_cluster(s, &request, pos, len, qed_is_allocated_cb, &cb);
/* Now sleep if the callback wasn't invoked immediately */
while (cb.is_allocated == -1) {
qemu_aio_wait();
cb.co = qemu_coroutine_self();
qemu_coroutine_yield();
}
qed_unref_l2_cache_entry(request.l2_table);
@ -1485,7 +1492,7 @@ static BlockDriver bdrv_qed = {
.bdrv_open = bdrv_qed_open,
.bdrv_close = bdrv_qed_close,
.bdrv_create = bdrv_qed_create,
.bdrv_is_allocated = bdrv_qed_is_allocated,
.bdrv_co_is_allocated = bdrv_qed_co_is_allocated,
.bdrv_make_empty = bdrv_qed_make_empty,
.bdrv_aio_readv = bdrv_qed_aio_readv,
.bdrv_aio_writev = bdrv_qed_aio_writev,