rdma: Add bind option

In certain configurations it can be useful to bind a rdma_cm to a
particular network interface. For example in multi-path or loopback.

Add a bindname option that the local rdma_cm will try and bind too.

The bind code is based off that used in rping [1].

[1] https://github.com/linux-rdma/rdma-core/blob/ \
    master/librdmacm/examples/rping.c

Signed-off-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/engines/rdma.c b/engines/rdma.c
index da00cba8b66b3f6db0bcd3a9cba8b45b9362ffa7..6b173a84a197258a9e7b80f4b3205a8ccb06dc93 100644 (file)
--- a/engines/rdma.c
+++ b/engines/rdma.c
@@ -59,6 +59,7 @@ struct rdmaio_options {
        struct thread_data *td;
        unsigned int port;
        enum rdma_io_mode verb;
+       char *bindname;
 };
 
 static int str_hostname_cb(void *data, const char *input)
@@ -81,6 +82,16 @@ static struct fio_option options[] = {
                .category = FIO_OPT_C_ENGINE,
                .group  = FIO_OPT_G_RDMA,
        },
+       {
+               .name   = "bindname",
+               .lname  = "rdma engine bindname",
+               .type   = FIO_OPT_STR_STORE,
+               .off1   = offsetof(struct rdmaio_options, bindname),
+               .help   = "Bind for RDMA IO engine",
+               .def    = "",
+               .category = FIO_OPT_C_ENGINE,
+               .group  = FIO_OPT_G_RDMA,
+       },
        {
                .name   = "port",
                .lname  = "rdma engine port",
@@ -1004,30 +1015,53 @@ static int fio_rdmaio_close_file(struct thread_data *td, struct fio_file *f)
        return 0;
 }
 
+static int aton(struct thread_data *td, const char *host,
+                    struct sockaddr_in *addr)
+{
+       if (inet_aton(host, &addr->sin_addr) != 1) {
+               struct hostent *hent;
+
+               hent = gethostbyname(host);
+               if (!hent) {
+                       td_verror(td, errno, "gethostbyname");
+                       return 1;
+               }
+
+               memcpy(&addr->sin_addr, hent->h_addr, 4);
+       }
+       return 0;
+}
+
 static int fio_rdmaio_setup_connect(struct thread_data *td, const char *host,
                                    unsigned short port)
 {
        struct rdmaio_data *rd = td->io_ops_data;
+       struct rdmaio_options *o = td->eo;
+       struct sockaddr_storage addrb;
        struct ibv_recv_wr *bad_wr;
        int err;
 
        rd->addr.sin_family = AF_INET;
        rd->addr.sin_port = htons(port);
 
-       if (inet_aton(host, &rd->addr.sin_addr) != 1) {
-               struct hostent *hent;
+       err = aton(td, host, &rd->addr);
+       if (err)
+               return err;
 
-               hent = gethostbyname(host);
-               if (!hent) {
-                       td_verror(td, errno, "gethostbyname");
-                       return 1;
-               }
+       /* resolve route */
+       if (strcmp(o->bindname, "") != 0) {
+               addrb.ss_family = AF_INET;
+               err = aton(td, o->bindname, (struct sockaddr_in *)&addrb);
+               if (err)
+                       return err;
+               err = rdma_resolve_addr(rd->cm_id, (struct sockaddr *)&addrb,
+                                       (struct sockaddr *)&rd->addr, 2000);
 
-               memcpy(&rd->addr.sin_addr, hent->h_addr, 4);
+       } else {
+               err = rdma_resolve_addr(rd->cm_id, NULL,
+                                       (struct sockaddr *)&rd->addr, 2000);
        }
 
-       /* resolve route */
-       err = rdma_resolve_addr(rd->cm_id, NULL, (struct sockaddr *)&rd->addr, 2000);
        if (err != 0) {
                log_err("fio: rdma_resolve_addr: %d\n", err);
                return 1;
@@ -1072,15 +1106,20 @@ static int fio_rdmaio_setup_connect(struct thread_data *td, const char *host,
 static int fio_rdmaio_setup_listen(struct thread_data *td, short port)
 {
        struct rdmaio_data *rd = td->io_ops_data;
+       struct rdmaio_options *o = td->eo;
        struct ibv_recv_wr *bad_wr;
        int state = td->runstate;
 
        td_set_runstate(td, TD_SETTING_UP);
 
        rd->addr.sin_family = AF_INET;
-       rd->addr.sin_addr.s_addr = htonl(INADDR_ANY);
        rd->addr.sin_port = htons(port);
 
+       if (strcmp(o->bindname, "") == 0)
+               rd->addr.sin_addr.s_addr = htonl(INADDR_ANY);
+       else
+               rd->addr.sin_addr.s_addr = htonl(*o->bindname);
+
        /* rdma_listen */
        if (rdma_bind_addr(rd->cm_id, (struct sockaddr *)&rd->addr) != 0) {
                log_err("fio: rdma_bind_addr fail: %m\n");
@@ -1155,7 +1194,8 @@ static int compat_options(struct thread_data *td)
 {
        // The original RDMA engine had an ugly / seperator
        // on the filename for it's options. This function
-       // retains backwards compatibility with it.100
+       // retains backwards compatibility with it. Note we do not
+       // support setting the bindname option is this legacy mode.
 
        struct rdmaio_options *o = td->eo;
        char *modep, *portp;