| Message ID | 20210614082931.24925-4-eesposit@redhat.com |
|---|---|
| State | New |
| Headers | show |
| Series | blkdebug: fix racing condition when iterating on | expand |
On 14.06.21 10:29, Emanuele Giuseppe Esposito wrote: > Add a counter for each action that a rule can trigger. > This is mainly used to keep track of how many coroutine_yield() > we need to perform after processing all rules in the list. > > Co-developed-by: Paolo Bonzini<pbonzini@redhat.com> > Signed-off-by: Emanuele Giuseppe Esposito<eesposit@redhat.com> > Reviewed-by: Vladimir Sementsov-Ogievskiy<vsementsov@virtuozzo.com> > --- > block/blkdebug.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/block/blkdebug.c b/block/blkdebug.c > index e8fdf7b056..6bdeb2c7b3 100644 > --- a/block/blkdebug.c > +++ b/block/blkdebug.c > @@ -74,6 +74,7 @@ enum { > ACTION_INJECT_ERROR, > ACTION_SET_STATE, > ACTION_SUSPEND, > + ACTION__MAX, > }; > > typedef struct BlkdebugRule { > @@ -791,22 +792,22 @@ static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule) > qemu_coroutine_yield(); > } > > -static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, > - bool injected) > +static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, > + int *action_count) I would have liked a comment above this function explaining that `action_count` is not merely an int pointer, but actually an int[ACTION__MAX] pointer. But it’s too late to complain about that now. O:) > { > BDRVBlkdebugState *s = bs->opaque; > > /* Only process rules for the current state */ > if (rule->state && rule->state != s->state) { > - return injected; > + return; > } > > /* Take the action */ > + action_count[rule->action]++; > switch (rule->action) { > case ACTION_INJECT_ERROR: > - if (!injected) { > + if (action_count[ACTION_INJECT_ERROR] == 1) { > QSIMPLEQ_INIT(&s->active_rules); (I don’t quite understand this part – why do we clear the list of active rules here? And why only if a new error is injected? For example, if I have an inject-error rule that should only fire on state 1, and then the state changes to state 2, it stays active until a new error is injected, which doesn’t make sense to me. But that has nothing to do with this series, of course. I’m just wondering.) Max > - injected = true; > } > QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next); > break; > > >
diff --git a/block/blkdebug.c b/block/blkdebug.c index e8fdf7b056..6bdeb2c7b3 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -74,6 +74,7 @@ enum { ACTION_INJECT_ERROR, ACTION_SET_STATE, ACTION_SUSPEND, + ACTION__MAX, }; typedef struct BlkdebugRule { @@ -791,22 +792,22 @@ static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule) qemu_coroutine_yield(); } -static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, - bool injected) +static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, + int *action_count) { BDRVBlkdebugState *s = bs->opaque; /* Only process rules for the current state */ if (rule->state && rule->state != s->state) { - return injected; + return; } /* Take the action */ + action_count[rule->action]++; switch (rule->action) { case ACTION_INJECT_ERROR: - if (!injected) { + if (action_count[ACTION_INJECT_ERROR] == 1) { QSIMPLEQ_INIT(&s->active_rules); - injected = true; } QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next); break; @@ -819,21 +820,19 @@ static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, suspend_request(bs, rule); break; } - return injected; } static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event) { BDRVBlkdebugState *s = bs->opaque; struct BlkdebugRule *rule, *next; - bool injected; + int actions_count[ACTION__MAX] = { 0 }; assert((int)event >= 0 && event < BLKDBG__MAX); - injected = false; s->new_state = s->state; QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) { - injected = process_rule(bs, rule, injected); + process_rule(bs, rule, actions_count); } s->state = s->new_state; }