From f48ff5af13eed0d2b39fdb91a37ed45fa3429e89 Mon Sep 17 00:00:00 2001 From: Emanuele Giuseppe Esposito Date: Mon, 14 Jun 2021 10:29:27 +0200 Subject: [PATCH] blkdebug: move post-resume handling to resume_req_by_tag We want to move qemu_coroutine_yield() after the loop on rules, because QLIST_FOREACH_SAFE is wrong if the rule list is modified while the coroutine has yielded. Therefore move the suspended request to the heap and clean it up from the remove side. All that is left is for blkdebug_debug_event to handle the yielding. Co-developed-by: Paolo Bonzini Signed-off-by: Emanuele Giuseppe Esposito Reviewed-by: Vladimir Sementsov-Ogievskiy Message-Id: <20210614082931.24925-3-eesposit@redhat.com> Signed-off-by: Max Reitz --- block/blkdebug.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/block/blkdebug.c b/block/blkdebug.c index 5ccbfcab42..e8fdf7b056 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -775,25 +775,20 @@ static void blkdebug_close(BlockDriverState *bs) static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule) { BDRVBlkdebugState *s = bs->opaque; - BlkdebugSuspendedReq r; + BlkdebugSuspendedReq *r; - r = (BlkdebugSuspendedReq) { - .co = qemu_coroutine_self(), - .tag = g_strdup(rule->options.suspend.tag), - }; + r = g_new(BlkdebugSuspendedReq, 1); + + r->co = qemu_coroutine_self(); + r->tag = g_strdup(rule->options.suspend.tag); remove_rule(rule); - QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next); + QLIST_INSERT_HEAD(&s->suspended_reqs, r, next); if (!qtest_enabled()) { - printf("blkdebug: Suspended request '%s'\n", r.tag); + printf("blkdebug: Suspended request '%s'\n", r->tag); } qemu_coroutine_yield(); - if (!qtest_enabled()) { - printf("blkdebug: Resuming request '%s'\n", r.tag); - } - - g_free(r.tag); } static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, @@ -880,8 +875,18 @@ retry: */ QLIST_FOREACH(r, &s->suspended_reqs, next) { if (!strcmp(r->tag, tag)) { + Coroutine *co = r->co; + + if (!qtest_enabled()) { + printf("blkdebug: Resuming request '%s'\n", r->tag); + } + QLIST_REMOVE(r, next); - qemu_coroutine_enter(r->co); + g_free(r->tag); + g_free(r); + + qemu_coroutine_enter(co); + if (all) { goto retry; }