RDMA/iwcm: Use a default listen backlog if needed

If the user creates a listening cm_id with backlog of 0 the IWCM ends
up not allowing any connection requests at all.  The correct behavior
is for the IWCM to pick a default value if the user backlog parameter
is zero.

Lustre from version 1.8.8 onward uses a backlog of 0, which breaks
iwarp support without this fix.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This commit is contained in:
Steve Wise 2014-07-25 09:11:33 -05:00 committed by Roland Dreier
parent 64aa90f26c
commit 2f0304d218
1 changed files with 27 additions and 0 deletions

View File

@ -46,6 +46,7 @@
#include <linux/completion.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/sysctl.h>
#include <rdma/iw_cm.h>
#include <rdma/ib_addr.h>
@ -65,6 +66,20 @@ struct iwcm_work {
struct list_head free_list;
};
static unsigned int default_backlog = 256;
static struct ctl_table_header *iwcm_ctl_table_hdr;
static struct ctl_table iwcm_ctl_table[] = {
{
.procname = "default_backlog",
.data = &default_backlog,
.maxlen = sizeof(default_backlog),
.mode = 0644,
.proc_handler = proc_dointvec,
},
{ }
};
/*
* The following services provide a mechanism for pre-allocating iwcm_work
* elements. The design pre-allocates them based on the cm_id type:
@ -425,6 +440,9 @@ int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
if (!backlog)
backlog = default_backlog;
ret = alloc_work_entries(cm_id_priv, backlog);
if (ret)
return ret;
@ -1030,11 +1048,20 @@ static int __init iw_cm_init(void)
if (!iwcm_wq)
return -ENOMEM;
iwcm_ctl_table_hdr = register_net_sysctl(&init_net, "net/iw_cm",
iwcm_ctl_table);
if (!iwcm_ctl_table_hdr) {
pr_err("iw_cm: couldn't register sysctl paths\n");
destroy_workqueue(iwcm_wq);
return -ENOMEM;
}
return 0;
}
static void __exit iw_cm_cleanup(void)
{
unregister_net_sysctl_table(iwcm_ctl_table_hdr);
destroy_workqueue(iwcm_wq);
}