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Re: (ITS#6845) sortvals oddities - with more information



Howard Chu <hyc@symas.com> writes:

>> It would seem that attr_merge() (in attr.c) should have something like this:
>>
>>          if ( *a == NULL ) {
>>                  *a = attr_alloc( desc );
>>                  if (desc->ad_type->sat_flags&  SLAP_AT_SORTED_VAL) {
>>                    (*a)->a_flags |= SLAP_ATTR_SORTED_VALS;
>>                  }
>>          } else {
>
> This is now fixed in HEAD in value.c.

Tested, bad behavior still persists. The call path I've observed
is as follows:

T@5    : | | | | | >bdb_modify_internal
T@5    : | | | | | | >modify_add_values
T@5    : | | | | | | | >attr_merge
T@5    : | | | | | | | | >attr_alloc

ordered_value_add() doesn't seem to be involved (I can provide the
entire trace if necessary)

>> Further pursuing the issue, I started to focus on the index deletion
>> code that was changed as a part of ITS#5183. Specifically, the
>> portion of code within bdb_modify_internal() (in back-bdb/modify.c)
>> that is commented:
>>
>>                    /* Move deleted values to end of array */
>>
>> This code modifies save_attrs, which is actually apparently a pointer
>> to memory that resides within the cache. If a deadlock occurs, these
>> changes are not reverted, thereby corrupting the entry in the cache. I
>> replaced this code with the pre-ITS#5183 code and I am no longer able
>> to 'break' the object and insert duplicate member/memberUids.
>
> This is now fixed in HEAD.

Looks good, thanks.

-- 
Andrew W. Elble
aweits@discipline.rit.edu
Infrastructure Engineer, Communications Technical Lead
Rochester Institute of Technology
PGP: BFAD 8461 4CCF DC95 DA2C B0EB 965B 082E 863E C912

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