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sheepdog: cancel aio requests if possible

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This patch tries to cancel aio requests in pending queue and failed
queue.  When the sheepdog driver cannot cancel the requests, it waits
for them to be completed.

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Tested-by: Liu Yuan <namei.unix@gmail.com>
Reviewed-by: Liu Yuan <namei.unix@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
MORITA Kazutaka 2013-10-24 16:01:17 +09:00 committed by Kevin Wolf
parent a37dcdf9ae
commit 35200687a1
1 changed files with 59 additions and 11 deletions
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70
block/sheepdog.c
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@ -299,7 +299,8 @@ struct SheepdogAIOCB {
Coroutine *coroutine;
void (*aio_done_func)(SheepdogAIOCB *);
bool canceled;
bool cancelable;
bool *finished;
int nr_pending;
};
@ -418,6 +419,7 @@ static inline void free_aio_req(BDRVSheepdogState *s, AIOReq *aio_req)
{
SheepdogAIOCB *acb = aio_req->aiocb;
acb->cancelable = false;
QLIST_REMOVE(aio_req, aio_siblings);
g_free(aio_req);
@ -426,23 +428,68 @@ static inline void free_aio_req(BDRVSheepdogState *s, AIOReq *aio_req)
static void coroutine_fn sd_finish_aiocb(SheepdogAIOCB *acb)
{
if (!acb->canceled) {
qemu_coroutine_enter(acb->coroutine, NULL);
qemu_coroutine_enter(acb->coroutine, NULL);
if (acb->finished) {
*acb->finished = true;
}
qemu_aio_release(acb);
}
/*
* Check whether the specified acb can be canceled
*
* We can cancel aio when any request belonging to the acb is:
* - Not processed by the sheepdog server.
* - Not linked to the inflight queue.
*/
static bool sd_acb_cancelable(const SheepdogAIOCB *acb)
{
BDRVSheepdogState *s = acb->common.bs->opaque;
AIOReq *aioreq;
if (!acb->cancelable) {
return false;
}
QLIST_FOREACH(aioreq, &s->inflight_aio_head, aio_siblings) {
if (aioreq->aiocb == acb) {
return false;
}
}
return true;
}
static void sd_aio_cancel(BlockDriverAIOCB *blockacb)
{
SheepdogAIOCB *acb = (SheepdogAIOCB *)blockacb;
BDRVSheepdogState *s = acb->common.bs->opaque;
AIOReq *aioreq, *next;
bool finished = false;
/*
* Sheepdog cannot cancel the requests which are already sent to
* the servers, so we just complete the request with -EIO here.
*/
acb->ret = -EIO;
qemu_coroutine_enter(acb->coroutine, NULL);
acb->canceled = true;
acb->finished = &finished;
while (!finished) {
if (sd_acb_cancelable(acb)) {
/* Remove outstanding requests from pending and failed queues. */
QLIST_FOREACH_SAFE(aioreq, &s->pending_aio_head, aio_siblings,
next) {
if (aioreq->aiocb == acb) {
free_aio_req(s, aioreq);
}
}
QLIST_FOREACH_SAFE(aioreq, &s->failed_aio_head, aio_siblings,
next) {
if (aioreq->aiocb == acb) {
free_aio_req(s, aioreq);
}
}
assert(acb->nr_pending == 0);
sd_finish_aiocb(acb);
return;
}
qemu_aio_wait();
}
}
static const AIOCBInfo sd_aiocb_info = {
@ -463,7 +510,8 @@ static SheepdogAIOCB *sd_aio_setup(BlockDriverState *bs, QEMUIOVector *qiov,
acb->nb_sectors = nb_sectors;
acb->aio_done_func = NULL;
acb->canceled = false;
acb->cancelable = true;
acb->finished = NULL;
acb->coroutine = qemu_coroutine_self();
acb->ret = 0;
acb->nr_pending = 0;