[PATCH 4.14 081/222] RDMA/core: Do not expose unsupported counters

Greg Kroah-Hartman
2018-11-11T23:03:35Z

From: Parav Pandit <parav@mellanox.com>

[ Upstream commit 0f6ef65d1c6ec8deb5d0f11f86631ec4cfe8f22e ]

If the provider driver (such as rdma_rxe) doesn't support pma counters,
avoid exposing its directory similar to optional hw_counters directory.
If core fails to read the PMA counter, return an error so that user can
retry later if needed.

Fixes: 35c4cbb17811 ("IB/core: Create get_perf_mad function in sysfs.c")
Reported-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/infiniband/core/sysfs.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)

--- a/drivers/infiniband/core/sysfs.c
+++ b/drivers/infiniband/core/sysfs.c
@@ -489,7 +489,7 @@ static ssize_t show_pma_counter(struct i
ret = get_perf_mad(p->ibdev, p->port_num, tab_attr->attr_id, &data,
40 + offset / 8, sizeof(data));
if (ret < 0)
- return sprintf(buf, "N/A (no PMA)\n");
+ return ret;

switch (width) {
case 4:
@@ -1012,10 +1012,12 @@ static int add_port(struct ib_device *de
goto err_put;
}

- p->pma_table = get_counter_table(device, port_num);
- ret = sysfs_create_group(&p->kobj, p->pma_table);
- if (ret)
- goto err_put_gid_attrs;
+ if (device->process_mad) {
+ p->pma_table = get_counter_table(device, port_num);
+ ret = sysfs_create_group(&p->kobj, p->pma_table);
+ if (ret)
+ goto err_put_gid_attrs;
+ }

p->gid_group.name = "gids";
p->gid_group.attrs = alloc_group_attrs(show_port_gid, attr.gid_tbl_len);
@@ -1128,7 +1130,8 @@ err_free_gid:
p->gid_group.attrs = NULL;

err_remove_pma:
- sysfs_remove_group(&p->kobj, p->pma_table);
+ if (p->pma_table)
+ sysfs_remove_group(&p->kobj, p->pma_table);

err_put_gid_attrs:
kobject_put(&p->gid_attr_group->kobj);
@@ -1240,7 +1243,9 @@ static void free_port_list_attributes(st
kfree(port->hw_stats);
free_hsag(&port->kobj, port->hw_stats_ag);
}
- sysfs_remove_group(p, port->pma_table);
+
+ if (port->pma_table)
+ sysfs_remove_group(p, port->pma_table);
sysfs_remove_group(p, &port->pkey_group);
sysfs_remove_group(p, &port->gid_group);
sysfs_remove_group(&port->gid_attr_group->kobj,