Why is inst->inst_ref_count == 0 when the instance is busy or in the process of being put offline or deleted?

Replying to [comment:2 rmeggins]:

Why is inst->inst_ref_count == 0 when the instance is busy or in the process of being put offline or deleted?

Sharp eyes! It was not escaped from you... I added "goto bail;" Even if slapi_counter_get_value(inst->inst_ref_count) was positive, the backend deletion was happening.
{{{
@@ -138,13 +138,20 @@ ldbm_instance_index_config_delete_callback(Slapi_PBlock pb, Slapi_Entry e, Sla
[...]
- if (slapi_counter_get_value(inst->inst_ref_count) > 0) {
+ if ((slapi_counter_get_value(inst->inst_ref_count) > 0) ||
+ is_instance_busy(inst) ||
+ / check if the backend is ON or not.
+ * If offline or being deleted, non SUCCESS is returned. /
+ (slapi_mapping_tree_select(pb, &be, &referral, returntext) != LDAP_SUCCESS)) {
*returncode = LDAP_UNAVAILABLE;
rc = SLAPI_DSE_CALLBACK_ERROR;
+ goto bail;
}
}}}

Is
{{{
+ is_instance_busy(inst) ||
+ / check if the backend is ON or not.
+ * If offline or being deleted, non SUCCESS is returned. /
+ (slapi_mapping_tree_select(pb, &be, &referral, returntext) != LDAP_SUCCESS)) {
}}}
this necessary to fix the bug? I think just the 'goto bail' will fix the bug.

If it is necessary to check both inst_ref_count and is_instance_busy, then I think we should fix our refcounting - that is, we should never decrement the refcount if the instance is busy.

You need to declare be and referral.

Do you need to free or release be and/or referral if they are active and returned by slapi_mapping_tree_select()?

Well, I was just conservative. We could remove "is_instance_busy(inst)" check.

Do you need to free or release be and/or referral if they are active and returned by slapi_mapping_tree_select()?

Ah, referral yes, be no need. I'm updating the patch.

git patch file (master)
0001-Ticket-48250-Slapd-crashes-reported-from-latest-buil.patch

Thanks for the comments and discussion, Rich. I've replaced the patch.

Reviewed by Rich (Thank you!!)

Pushed to master:
88e7242..01fea1f master -> master
commit 01fea1f

Pushed to 389-ds-base-1.3.4:
a80fe15..7a4b0a7 389-ds-base-1.3.4 -> 389-ds-base-1.3.4
commit 7a4b0a7

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