From bb44e0bbcea21e50aaed1bd54d0aa53c46cecbf1 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 1 Jul 2010 16:08:51 +0200 Subject: [PATCH] block: Handle multiwrite errors only when all requests have completed Don't try to be clever by freeing all temporary data and calling all callbacks when the return value (an error) is certain. Doing so has at least two important problems: * The temporary data that is freed (qiov, possibly zero buffer) is still used by the requests that have not yet completed. * Calling the callbacks for all requests in the multiwrite means for the caller that it may free buffers etc. which are still in use. Just remember the error value and do the cleanup when all requests have completed. Signed-off-by: Kevin Wolf (cherry picked from commit de189a1b4a471d37a2909e97646654fc9751b52f) --- block.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/block.c b/block.c index 80f2faecd..169478046 100644 --- a/block.c +++ b/block.c @@ -1661,14 +1661,11 @@ static void multiwrite_cb(void *opaque, int ret) if (ret < 0 && !mcb->error) { mcb->error = ret; - multiwrite_user_cb(mcb); } mcb->num_requests--; if (mcb->num_requests == 0) { - if (mcb->error == 0) { - multiwrite_user_cb(mcb); - } + multiwrite_user_cb(mcb); qemu_free(mcb); } } -- 2.39.2