On Mon, Aug 19 2024, Xiubo Li wrote:
> Hi Luis,
>
> Good catch!
>
> On 8/14/24 18:17, Luis Henriques (SUSE) wrote:
>> The cap_auths that are allocated during an MDS session opening are never
>> released, causing a memory leak detected by kmemleak. Fix this by freeing
>> the memory allocated when shutting down the mds client.
>>
>> Fixes: 1d17de9534cb ("ceph: save cap_auths in MDS client when session is opened")
>> Signed-off-by: Luis Henriques (SUSE) <luis.henriques@xxxxxxxxx>
>> ---
>> fs/ceph/mds_client.c | 14 ++++++++++++++
>> 1 file changed, 14 insertions(+)
>>
>> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
>> index 276e34ab3e2c..d798d0a5b2b1 100644
>> --- a/fs/ceph/mds_client.c
>> +++ b/fs/ceph/mds_client.c
>> @@ -6015,6 +6015,20 @@ static void ceph_mdsc_stop(struct ceph_mds_client *mdsc)
>> ceph_mdsmap_destroy(mdsc->mdsmap);
>> kfree(mdsc->sessions);
>> ceph_caps_finalize(mdsc);
>> +
>> + if (mdsc->s_cap_auths) {
>> + int i;
>> +
>> + mutex_lock(&mdsc->mutex);
>
> BTW, is the lock really needed here ?
>
> IMO it should be safe to remove it because once here the sb has already been
> killed and the 'mdsc->stopping' will help guarantee that there won't be any
> other thread will access to 'mdsc', Isn't it ?
Ah, yes, good point. Thanks, I'll send v2 shortly.
Cheers,
--
Luís
> Else we need to do the lock from the beginning of this function.
>
> Thanks
>
> - Xiubo
>
>> + for (i = 0; i < mdsc->s_cap_auths_num; i++) {
>> + kfree(mdsc->s_cap_auths[i].match.gids);
>> + kfree(mdsc->s_cap_auths[i].match.path);
>> + kfree(mdsc->s_cap_auths[i].match.fs_name);
>> + }
>> + kfree(mdsc->s_cap_auths);
>> + mutex_unlock(&mdsc->mutex);
>> + }
>> +
>> ceph_pool_perm_destroy(mdsc);
>> }
>>
>
