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@linux.dev>
---
Changes since v1:
 * dropped mdsc->mutex locking as we don't need it at this point

 fs/ceph/mds_client.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 276e34ab3e2c..2e4b3ee7446c 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -6015,6 +6015,18 @@ 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;
+
+		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);
+	}
+
 	ceph_pool_perm_destroy(mdsc);
 }

On 8/19/24 17:52, 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@linux.dev>
> ---
> Changes since v1:
>   * dropped mdsc->mutex locking as we don't need it at this point
>
>   fs/ceph/mds_client.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 276e34ab3e2c..2e4b3ee7446c 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -6015,6 +6015,18 @@ 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;
> +
> +		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);
> +	}
> +
>   	ceph_pool_perm_destroy(mdsc);
>   }
>   

LGTM.

Reviewed-by: Xiubo Li <xiubli@redhat.com>

Will apply to the testing branch and run the tests.

Thanks Luis

- Xiubo