net/smc: handle unregistered buffers

When smc_wr_reg_send() fails then tag (regerr) the affected buffer and
free it in smc_buf_unuse().

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 24 insertions, 5 deletions

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index fdb2976117bd..d03b8d29ffc0 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -296,8 +296,10 @@ static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 static int smc_reg_rmb(struct smc_link *link, struct smc_buf_desc *rmb_desc)
 {
         /* register memory region for new rmb */
-        if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK]))
+        if (smc_wr_reg_send(link, rmb_desc->mr_rx[SMC_SINGLE_LINK])) {
+                rmb_desc->regerr = 1;
                 return -EFAULT;
+        }
         return 0;
 }
 
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index f44f6803f7ff..d4bd01bb44e1 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -32,6 +32,9 @@
 
 static u32 smc_lgr_num;                 /* unique link group number */
 
+static void smc_buf_free(struct smc_buf_desc *buf_desc, struct smc_link *lnk,
+                         bool is_rmb);
+
 static void smc_lgr_schedule_free_work(struct smc_link_group *lgr)
 {
         /* client link group creation always follows the server link group
@@ -234,9 +237,22 @@ static void smc_buf_unuse(struct smc_connection *conn)
                 conn->sndbuf_size = 0;
         }
         if (conn->rmb_desc) {
-                conn->rmb_desc->reused = true;
-                conn->rmb_desc->used = 0;
-                conn->rmbe_size = 0;
+                if (!conn->rmb_desc->regerr) {
+                        conn->rmb_desc->reused = 1;
+                        conn->rmb_desc->used = 0;
+                        conn->rmbe_size = 0;
+                } else {
+                        /* buf registration failed, reuse not possible */
+                        struct smc_link_group *lgr = conn->lgr;
+                        struct smc_link *lnk;
+
+                        write_lock_bh(&lgr->rmbs_lock);
+                        list_del(&conn->rmb_desc->list);
+                        write_unlock_bh(&lgr->rmbs_lock);
+
+                        lnk = &lgr->lnk[SMC_SINGLE_LINK];
+                        smc_buf_free(conn->rmb_desc, lnk, true);
+                }
         }
 }
 
diff --git a/net/smc/smc_core.h b/net/smc/smc_core.h
index 07e2a393e6d9..5dfcb15d529f 100644
--- a/net/smc/smc_core.h
+++ b/net/smc/smc_core.h
@@ -123,7 +123,8 @@ struct smc_buf_desc {
                                                  */
         u32                     order;          /* allocation order */
         u32                     used;           /* currently used / unused */
-        bool                    reused;         /* new created / reused */
+        u8                      reused  : 1;    /* new created / reused */
+        u8                      regerr  : 1;    /* err during registration */
 };
 
 struct smc_rtoken {                             /* address/key of remote RMB */