From 384acbf46b70edf0d2c1648aa1a92a90bcf7057d Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 15 Jul 2011 16:36:40 +0200 Subject: async: Remove AsyncContext The purpose of AsyncContexts was to protect qcow and qcow2 against reentrancy during an emulated bdrv_read/write (which includes a qemu_aio_wait() call and can run AIO callbacks of different requests if it weren't for AsyncContexts). Now both qcow and qcow2 are protected by CoMutexes and AsyncContexts can be removed. Signed-off-by: Kevin Wolf --- linux-aio.c | 43 ++++--------------------------------------- 1 file changed, 4 insertions(+), 39 deletions(-) (limited to 'linux-aio.c') diff --git a/linux-aio.c b/linux-aio.c index 68f4b3d75..dc3faf249 100644 --- a/linux-aio.c +++ b/linux-aio.c @@ -31,7 +31,6 @@ struct qemu_laiocb { struct iocb iocb; ssize_t ret; size_t nbytes; - int async_context_id; QLIST_ENTRY(qemu_laiocb) node; }; @@ -39,7 +38,6 @@ struct qemu_laio_state { io_context_t ctx; int efd; int count; - QLIST_HEAD(, qemu_laiocb) completed_reqs; }; static inline ssize_t io_event_ret(struct io_event *ev) @@ -49,7 +47,6 @@ static inline ssize_t io_event_ret(struct io_event *ev) /* * Completes an AIO request (calls the callback and frees the ACB). - * Be sure to be in the right AsyncContext before calling this function. */ static void qemu_laio_process_completion(struct qemu_laio_state *s, struct qemu_laiocb *laiocb) @@ -72,42 +69,12 @@ static void qemu_laio_process_completion(struct qemu_laio_state *s, } /* - * Processes all queued AIO requests, i.e. requests that have return from OS - * but their callback was not called yet. Requests that cannot have their - * callback called in the current AsyncContext, remain in the queue. - * - * Returns 1 if at least one request could be completed, 0 otherwise. + * All requests are directly processed when they complete, so there's nothing + * left to do during qemu_aio_wait(). */ static int qemu_laio_process_requests(void *opaque) { - struct qemu_laio_state *s = opaque; - struct qemu_laiocb *laiocb, *next; - int res = 0; - - QLIST_FOREACH_SAFE (laiocb, &s->completed_reqs, node, next) { - if (laiocb->async_context_id == get_async_context_id()) { - qemu_laio_process_completion(s, laiocb); - QLIST_REMOVE(laiocb, node); - res = 1; - } - } - - return res; -} - -/* - * Puts a request in the completion queue so that its callback is called the - * next time when it's possible. If we already are in the right AsyncContext, - * the request is completed immediately instead. - */ -static void qemu_laio_enqueue_completed(struct qemu_laio_state *s, - struct qemu_laiocb* laiocb) -{ - if (laiocb->async_context_id == get_async_context_id()) { - qemu_laio_process_completion(s, laiocb); - } else { - QLIST_INSERT_HEAD(&s->completed_reqs, laiocb, node); - } + return 0; } static void qemu_laio_completion_cb(void *opaque) @@ -141,7 +108,7 @@ static void qemu_laio_completion_cb(void *opaque) container_of(iocb, struct qemu_laiocb, iocb); laiocb->ret = io_event_ret(&events[i]); - qemu_laio_enqueue_completed(s, laiocb); + qemu_laio_process_completion(s, laiocb); } } } @@ -204,7 +171,6 @@ BlockDriverAIOCB *laio_submit(BlockDriverState *bs, void *aio_ctx, int fd, laiocb->nbytes = nb_sectors * 512; laiocb->ctx = s; laiocb->ret = -EINPROGRESS; - laiocb->async_context_id = get_async_context_id(); iocbs = &laiocb->iocb; @@ -239,7 +205,6 @@ void *laio_init(void) struct qemu_laio_state *s; s = qemu_mallocz(sizeof(*s)); - QLIST_INIT(&s->completed_reqs); s->efd = eventfd(0, 0); if (s->efd == -1) goto out_free_state; -- cgit v1.2.3