list-subsys: when running on old kernels, get PCIe B:D.f address from sysfs

Signed-off-by: Yair Elharrar <yair@excelero.com>

diff --git a/nvme-topology.c b/nvme-topology.c
index 431793905d8aa57165f1ba9fd197e42dfb48c543..55ad8c1244082dee660236982733f7b8da1999c0 100644 (file)
--- a/nvme-topology.c
+++ b/nvme-topology.c
@@ -89,6 +89,56 @@ err_free_path:
        return NULL;
 }
 
+static char *path_trim_last(char *path, char needle)
+{
+       int i;
+       i = strlen(path);
+       if (i>0 && path[i-1] == needle)         // remove trailing slash
+               path[--i] = 0;
+       for (; i>0; i--)
+               if (path[i] == needle) {
+                       path[i] = 0;
+                       return path+i+1;
+       }
+       return NULL;
+}
+
+static void legacy_get_pci_bdf(char *node, char *bdf)
+{
+       int ret;
+       char path[264], nodetmp[264];
+       struct stat st;
+       char *p, *__path = path;
+
+       bdf[0] = 0;
+       strcpy(nodetmp, node);
+       p = path_trim_last(nodetmp, '/');
+       sprintf(path, "/sys/block/%s/device", p);
+       ret = readlink(path, nodetmp, sizeof(nodetmp));
+       if (ret <= 0)
+               return;
+       nodetmp[ret] = 0;
+       /* The link value is either "device -> ../../../0000:86:00.0" or "device -> ../../nvme0" */
+       (void) path_trim_last(path, '/');
+       sprintf(path+strlen(path), "/%s/device", nodetmp);
+       ret = stat(path, &st);
+       if (ret < 0)
+               return;
+       if ((st.st_mode & S_IFLNK) == 0) {
+               /* follow the second link to get the PCI address */
+               ret = readlink(path, __path, sizeof(path));
+               if (ret <= 0)
+                       return;
+               path[ret] = 0;
+       }
+       else
+               (void) path_trim_last(path, '/');
+
+       p = path_trim_last(path, '/');
+       if (p && strlen(p) == 12)
+               strcpy(bdf, p);
+}
+
 static int scan_namespace(struct nvme_namespace *n)
 {
        int ret, fd;
@@ -303,6 +353,15 @@ static int verify_legacy_ns(struct nvme_namespace *n)
        if (ret < 0)
                return ret;
 
+       if (!n->ctrl->transport && !n->ctrl->address) {
+               char tmp_address[64] = "";
+               legacy_get_pci_bdf(path, tmp_address);
+               if (tmp_address[0]) {
+                       asprintf(&n->ctrl->transport, "pcie");
+                       asprintf(&n->ctrl->address, tmp_address);
+               }
+       }
+
        fd = open(path, O_RDONLY);
        free (path);