net/smc: unique reason code for exceeded max dmb count

When the maximum dmb buffer limit for an ism device is reached no more
dmb buffers can be registered. When this happens the reason code is set
to SMC_CLC_DECL_MEM indicating out-of-memory. This is the same reason
code that is used when no memory could be allocated for the new dmb
buffer.
This is confusing for users when they see this error but there is more
memory available. To solve this set a separate new reason code when the
maximum dmb limit exceeded.

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

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 832e36269b10046583bad6c3df57fcf820dfb4b0..e7649bbc2b87f5349c024f0fdd31cb5a4f9c9083 100644 (file)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -719,8 +719,11 @@ static int smc_connect_ism(struct smc_sock *smc,
        }
 
        /* Create send and receive buffers */
-       if (smc_buf_create(smc, true))
-               return smc_connect_abort(smc, SMC_CLC_DECL_MEM,
+       rc = smc_buf_create(smc, true);
+       if (rc)
+               return smc_connect_abort(smc, (rc == -ENOSPC) ?
+                                             SMC_CLC_DECL_MAX_DMB :
+                                             SMC_CLC_DECL_MEM,
                                         ini->cln_first_contact);
 
        smc_conn_save_peer_info(smc, aclc);
@@ -1200,12 +1203,14 @@ static int smc_listen_ism_init(struct smc_sock *new_smc,
        }
 
        /* Create send and receive buffers */
-       if (smc_buf_create(new_smc, true)) {
+       rc = smc_buf_create(new_smc, true);
+       if (rc) {
                if (ini->cln_first_contact == SMC_FIRST_CONTACT)
                        smc_lgr_cleanup_early(&new_smc->conn);
                else
                        smc_conn_free(&new_smc->conn);
-               return SMC_CLC_DECL_MEM;
+               return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
+                                        SMC_CLC_DECL_MEM;
        }
 
        return 0;

diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 76c2b150d040f3b4a10ae4f6e6c8d922a3107443..cf7b45306f4e7c5b3937cb2031470e5bd16b8af8 100644 (file)
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -48,6 +48,7 @@
 #define SMC_CLC_DECL_NOACTLINK 0x030a0000  /* no active smc-r link in lgr    */
 #define SMC_CLC_DECL_NOSRVLINK 0x030b0000  /* SMC-R link from srv not found  */
 #define SMC_CLC_DECL_VERSMISMAT        0x030c0000  /* SMC version mismatch           */
+#define SMC_CLC_DECL_MAX_DMB   0x030d0000  /* SMC-D DMB limit exceeded       */
 #define SMC_CLC_DECL_SYNCERR   0x04000000  /* synchronization error          */
 #define SMC_CLC_DECL_PEERDECL  0x05000000  /* peer declined during handshake */
 #define SMC_CLC_DECL_INTERR    0x09990000  /* internal error                 */

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index f82a2e59991719b54c67ca3c61ce607fdf76d5c6..b42fa3b00d00ae3507efe577fe1cfd5a6abf522b 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -1614,7 +1614,7 @@ static struct smc_buf_desc *smcd_new_buf_create(struct smc_link_group *lgr,
                rc = smc_ism_register_dmb(lgr, bufsize, buf_desc);
                if (rc) {
                        kfree(buf_desc);
-                       return ERR_PTR(-EAGAIN);
+                       return (rc == -ENOMEM) ? ERR_PTR(-EAGAIN) : ERR_PTR(rc);
                }
                buf_desc->pages = virt_to_page(buf_desc->cpu_addr);
                /* CDC header stored in buf. So, pretend it was smaller */
@@ -1688,7 +1688,7 @@ static int __smc_buf_create(struct smc_sock *smc, bool is_smcd, bool is_rmb)
        }
 
        if (IS_ERR(buf_desc))
-               return -ENOMEM;
+               return PTR_ERR(buf_desc);
 
        if (!is_smcd) {
                if (smcr_buf_map_usable_links(lgr, buf_desc, is_rmb)) {