From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wen Congyang Subject: [RFC Patch v2 04/17] blktap2: dynamic allocate aio_requests to avoid -EBUSY error Date: Fri, 8 Aug 2014 16:10:40 +0800 Message-ID: <1407485458-23213-6-git-send-email-wency@cn.fujitsu.com> References: <1407485458-23213-1-git-send-email-wency@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1407485458-23213-1-git-send-email-wency@cn.fujitsu.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen devel Cc: Ian Campbell , Wen Congyang , Ian Jackson , Jiang Yunhong , Dong Eddie , Shriram Rajagopalan , Yang Hongyang , Lai Jiangshan List-Id: xen-devel@lists.xenproject.org From: Lai Jiangshan In normal case, there are at most TAPDISK_DATA_REQUESTS request at the same time. But in remus mode, the write requests are forwarded from the master side, and cached in block-remus. All cached requests will be forwarded to aio driver when syncing primary vm and backup vm. In this case, The number of requests may be more than TAPDISK_DATA_REQUESTS. So aio driver can't hanlde these requests at the same time, it will cause tapdisk2 exit. We don't know how many requests will be handled, so dynamic allocate aio_requests to avoid this error. Signed-off-by: Lai Jiangshan Signed-off-by: Jiang Yunhong Signed-off-by: Wen Congyang Cc: Shriram Rajagopalan --- tools/blktap2/drivers/block-aio.c | 36 +++++++++++++++++++++++++++++++++--- 1 file changed, 33 insertions(+), 3 deletions(-) diff --git a/tools/blktap2/drivers/block-aio.c b/tools/blktap2/drivers/block-aio.c index f398da2..10ab20b 100644 --- a/tools/blktap2/drivers/block-aio.c +++ b/tools/blktap2/drivers/block-aio.c @@ -55,9 +55,10 @@ struct tdaio_state { int fd; td_driver_t *driver; + int aio_max_count; int aio_free_count; struct aio_request aio_requests[MAX_AIO_REQS]; - struct aio_request *aio_free_list[MAX_AIO_REQS]; + struct aio_request **aio_free_list; }; /*Get Image size, secsize*/ @@ -122,6 +123,11 @@ int tdaio_open(td_driver_t *driver, const char *name, td_flag_t flags) memset(prv, 0, sizeof(struct tdaio_state)); + prv->aio_free_list = malloc(MAX_AIO_REQS * sizeof(*prv->aio_free_list)); + if (!prv->aio_free_list) + return -ENOMEM; + + prv->aio_max_count = MAX_AIO_REQS; prv->aio_free_count = MAX_AIO_REQS; for (i = 0; i < MAX_AIO_REQS; i++) prv->aio_free_list[i] = &prv->aio_requests[i]; @@ -159,6 +165,28 @@ done: return ret; } +static int tdaio_refill(struct tdaio_state *prv) +{ + struct aio_request **new, *new_req; + int i, max = prv->aio_max_count + MAX_AIO_REQS; + + new = realloc(prv->aio_free_list, max * sizeof(*prv->aio_free_list)); + if (!new) + return -1; + prv->aio_free_list = new; + + new_req = calloc(MAX_AIO_REQS, sizeof(*new_req)); + if (!new_req) + return -1; + + prv->aio_max_count = max; + prv->aio_free_count = MAX_AIO_REQS; + for (i = 0; i < MAX_AIO_REQS; i++) + prv->aio_free_list[i] = &new_req[i]; + + return 0; +} + void tdaio_complete(void *arg, struct tiocb *tiocb, int err) { struct aio_request *aio = (struct aio_request *)arg; @@ -207,8 +235,10 @@ void tdaio_queue_write(td_driver_t *driver, td_request_t treq) size = treq.secs * driver->info.sector_size; offset = treq.sec * (uint64_t)driver->info.sector_size; - if (prv->aio_free_count == 0) - goto fail; + if (prv->aio_free_count == 0) { + if (tdaio_refill(prv) < 0) + goto fail; + } aio = prv->aio_free_list[--prv->aio_free_count]; aio->treq = treq; -- 1.9.3