[ofa-general] [PATCH] libibcm: get correct ucm device name

[Sean Hefty]

Search for the ucm device name that corresponds to a given libibverbs
device name.  When non-IB devices are present in the system, the ucm
device name can differ from the uverbs device name, so we need to
lookup the correct name.

Signed-off-by: Sean Hefty <sean.hefty at intel.com>
---
Jeff, can you give this a try and see if it works on your systems?  I've
tested the patch on my own system, but I only have 1 device in each of my
systems.  (I'm limited by my hardware here.)  If this works, this change,
and the other CM change to remove unneeded prints should both go into
the next OFED release.

diff --git a/src/cm.c b/src/cm.c
index c0bcba3..571e28a 100644
--- a/src/cm.c
+++ b/src/cm.c
@@ -67,6 +67,10 @@
 static int abi_ver;
 static pthread_mutex_t mut = PTHREAD_MUTEX_INITIALIZER;
 
+enum {
+	IB_UCM_MAX_DEVICES = 32
+};
+
 #define CM_CREATE_MSG_CMD_RESP(msg, cmd, resp, type, size) \
 do {                                        \
 	struct cm_abi_cmd_hdr *hdr;         \
@@ -147,35 +151,64 @@ static int ucm_init(void)
 	return ret;
 }
 
+static int ucm_get_dev_index(char *dev_name)
+{
+	char *dev_path;
+	char ibdev[IBV_SYSFS_NAME_MAX];
+	int i, ret;
+
+	for (i = 0; i < IB_UCM_MAX_DEVICES; i++) {
+		ret = asprintf(&dev_path, "/sys/class/infiniband_cm/ucm%d", i);
+		if (ret < 0)
+			return -1;
+
+		ret = ibv_read_sysfs_file(dev_path, "ibdev", ibdev, sizeof ibdev);
+		if (ret < 0)
+			continue;
+
+		if (!strcmp(dev_name, ibdev)) {
+			free(dev_path);
+			return i;
+		}
+
+		free(dev_path);
+	}
+	return -1;
+}
+
 struct ib_cm_device* ib_cm_open_device(struct ibv_context *device_context)
 {
 	struct ib_cm_device *dev;
 	char *dev_path;
+	int index, ret;
 
 	if (ucm_init())
 		return NULL;
 
+	index = ucm_get_dev_index(device_context->device->name);
+	if (index < 0)
+		return NULL;
+
 	dev = malloc(sizeof *dev);
 	if (!dev)
 		return NULL;
 
 	dev->device_context = device_context;
 
-	if (asprintf(&dev_path, "/dev/infiniband/ucm%s",
-		 device_context->device->dev_name + sizeof("uverbs") - 1) < 0)
-		goto err2;
+	ret = asprintf(&dev_path, "/dev/infiniband/ucm%d", index);
+	if (ret < 0)
+		goto err1;
 
 	dev->fd = open(dev_path, O_RDWR);
-	if (dev->fd < 0) {
-		goto err;
-	}
+	if (dev->fd < 0)
+		goto err2;
 
 	free(dev_path);
 	return dev;
 
-err:
-	free(dev_path);
 err2:
+	free(dev_path);
+err1:
 	free(dev);
 	return NULL;
 }