On 12/20/2012 02:20 PM, Simo Sorce wrote:
On Thu, 2012-12-20 at 12:29 +0100, Pavel Březina wrote:
> On 12/20/2012 06:10 AM, Simo Sorce wrote:
>> -static errno_t sss_mc_get_record(struct sss_mc_ctx *mcc,
>> +static errno_t sss_mc_get_record(struct sss_mc_ctx **_mcc,
>> size_t rec_len,
>> struct sized_string *key,
>> struct sss_mc_rec **_rec)
>> {
>> + struct sss_mc_ctx *mcc = *_mcc;
>> struct sss_mc_rec *old_rec = NULL;
>> struct sss_mc_rec *rec;
>> int old_slots;
>> @@ -424,6 +425,16 @@ static errno_t sss_mc_get_record(struct sss_mc_ctx *mcc,
>> /* we are going to use more space, find enough free slots */
>> ret = sss_mc_find_free_slots(mcc, num_slots, &base_slot);
>> if (ret != EOK) {
>> + if (ret == EFAULT) {
>> + TALLOC_CTX *parent;
>> + DEBUG(SSSDBG_CRIT_FAILURE,
>> + ("Fatal internal mmap cache error, invalidating
cache!\n"));
>> + parent = talloc_parent(mcc);
>> + if (parent == NULL) {
>> + talloc_zfree(*_mcc);
>> + }
>> + (void)sss_mmap_cache_reinit(parent, -1, -1, _mcc);
>> + }
>> return ret;
>> }
>
> Hi,
>
> Is if (parent == NULL) only precaution or can it actually happen?
Only a precaution, all the callers use an actual memory context.
> If you talloc_zfree(*_mcc) then you will hit EINVAL in reinit() and the
> cache won't be reinitialized. Is this intentional? If so, can you
> comment it in the code?
Well it was not intentional I meant to return after the free.
However I am wondering if we should really care ...
If the caller had NULL as the parent something may have gone wrong, but
at worst we will leak a few bytes... maybe I shouldn't consider a NULL
parent as an error after all. Opinions ?
Simo.
Does the memory cache require a parent context for some reason (do you
manipulate with the parent within the cache)?
If not I think you should not take care whether is has a parent or not.
For what we know, it may be intentional by the caller. Otherwise you
should check if mem_ctx != NULL in init().
Looking into the init() function I found out that you are using wrong
context:
mc_ctx->name = talloc_strdup(mem_ctx, name);
if (!mc_ctx->name) {
ret = ENOMEM;
goto done;
}
It should say mc_ctx not mem_ctx.