06.04.2020 20:14, Kevin Wolf wrote:
External callers of blk_co_*() don't currently increase the
BlockBackend.in_flight counter, but calls from blk_aio_*() do, so there
is an inconsistency whether the counter has been increased or not.
This patch moves the actual operations to static functions that can
later know they will always be called with in_flight increased exactly
once, even for external callers using the blk_co_*() coroutine
interfaces.
If the public blk_co_*() interface is unused, remove it.
Signed-off-by: Kevin Wolf <[email protected]>
Reviewed-by: Vladimir Sementsov-Ogievskiy <[email protected]>
Still, did you consider instead just move inc/dec to _co_ functions, like
@@ -1154,6 +1154,7 @@ int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t
offset,
int ret;
BlockDriverState *bs;
+ blk_inc_in_flight(blk);
blk_wait_while_drained(blk);
/* Call blk_bs() only after waiting, the graph may have changed */
@@ -1175,6 +1176,7 @@ int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t
offset,
ret = bdrv_co_preadv(blk->root, offset, bytes, qiov, flags);
bdrv_dec_in_flight(bs);
+ blk_dec_in_flight(blk);
return ret;
}
@@ -1337,7 +1339,6 @@ static void blk_aio_complete(BlkAioEmAIOCB *acb)
{
if (acb->has_returned) {
acb->common.cb(acb->common.opaque, acb->rwco.ret);
- blk_dec_in_flight(acb->rwco.blk);
qemu_aio_unref(acb);
}
}
@@ -1357,7 +1358,6 @@ static BlockAIOCB *blk_aio_prwv(BlockBackend *blk,
int64_t offset, int bytes,
BlkAioEmAIOCB *acb;
Coroutine *co;
- blk_inc_in_flight(blk);
acb = blk_aio_get(&blk_aio_em_aiocb_info, blk, cb, opaque);
acb->rwco = (BlkRwCo) {
.blk = blk,
@@ -1388,9 +1388,7 @@ static void blk_aio_read_entry(void *opaque)
QEMUIOVector *qiov = rwco->iobuf;
if (rwco->blk->quiesce_counter) {
- blk_dec_in_flight(rwco->blk);
blk_wait_while_drained(rwco->blk);
- blk_inc_in_flight(rwco->blk);
}
assert(qiov->size == acb->bytes);
(and same for write, ioctl, flush, discard). It seems more consistent.. Should
it work?
--
Best regards,
Vladimir
