drbd: Receiving part for the PROTOCOL_UPDATE packet

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index c59012f..75b26d8 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -225,6 +225,7 @@ enum drbd_packet {
        P_CONN_ST_CHG_REQ     = 0x2a, /* data sock: Connection wide state request */
        P_CONN_ST_CHG_REPLY   = 0x2b, /* meta sock: Connection side state req reply */
        P_RETRY_WRITE         = 0x2c, /* Protocol C: retry conflicting write request */
+       P_PROTOCOL_UPDATE     = 0x2d, /* data sock: is used in established connections */
 
        P_MAY_IGNORE          = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
        P_MAX_OPT_CMD         = 0x101,
@@ -849,7 +850,7 @@ struct drbd_tconn {                 /* is a resource from the config file */
 
        struct crypto_hash *cram_hmac_tfm;
        struct crypto_hash *integrity_tfm;  /* checksums we compute, updates protected by tconn->data->mutex */
-       struct crypto_hash *peer_integrity_tfm;  /* checksums we verify */
+       struct crypto_hash *peer_integrity_tfm;  /* checksums we verify, only accessed from receiver thread  */
        struct crypto_hash *csums_tfm;
        struct crypto_hash *verify_tfm;
        void *int_dig_in;

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index bca599a..4133335 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -3290,6 +3290,8 @@ const char *cmdname(enum drbd_packet cmd)
                [P_RS_CANCEL]           = "RSCancel",
                [P_CONN_ST_CHG_REQ]     = "conn_st_chg_req",
                [P_CONN_ST_CHG_REPLY]   = "conn_st_chg_reply",
+               [P_RETRY_WRITE]         = "retry_write",
+               [P_PROTOCOL_UPDATE]     = "protocol_update",
 
                /* enum drbd_packet, but not commands - obsoleted flags:
                 *      P_MAY_IGNORE

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 61b57fc..9611303 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3001,9 +3001,11 @@ static enum drbd_after_sb_p convert_after_sb(enum drbd_after_sb_p peer)
 static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
 {
        struct p_protocol *p = pi->data;
-       int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
-       int p_discard_my_data, p_two_primaries, cf;
-       struct net_conf *nc;
+       enum drbd_after_sb_p p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
+       int p_proto, p_discard_my_data, p_two_primaries, cf;
+       struct net_conf *nc, *old_net_conf, *new_net_conf = NULL;
+       char integrity_alg[SHARED_SECRET_MAX] = "";
+       struct crypto_hash *peer_tfm = NULL, *tfm = NULL;
        void *int_dig_in = NULL, *int_dig_vv = NULL;
 
        p_proto         = be32_to_cpu(p->protocol);
@@ -3015,8 +3017,6 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
        p_discard_my_data = cf & CF_DISCARD_MY_DATA;
 
        if (tconn->agreed_pro_version >= 87) {
-               char integrity_alg[SHARED_SECRET_MAX];
-               struct crypto_hash *tfm = NULL;
                int err;
 
                if (pi->size > sizeof(integrity_alg))
@@ -3024,35 +3024,70 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
                err = drbd_recv_all(tconn, integrity_alg, pi->size);
                if (err)
                        return err;
-               integrity_alg[SHARED_SECRET_MAX-1] = 0;
+               integrity_alg[SHARED_SECRET_MAX - 1] = 0;
+       }
 
+       if (pi->cmd == P_PROTOCOL_UPDATE) {
                if (integrity_alg[0]) {
                        int hash_size;
 
-                       tfm = crypto_alloc_hash(integrity_alg, 0, CRYPTO_ALG_ASYNC);
-                       if (!tfm) {
+                       peer_tfm = crypto_alloc_hash(integrity_alg, 0, CRYPTO_ALG_ASYNC);
+                       tfm      = crypto_alloc_hash(integrity_alg, 0, CRYPTO_ALG_ASYNC);
+                       if (!(peer_tfm && tfm)) {
                                conn_err(tconn, "peer data-integrity-alg %s not supported\n",
                                         integrity_alg);
                                goto disconnect;
                        }
-                       conn_info(tconn, "peer data-integrity-alg: %s\n", integrity_alg);
 
                        hash_size = crypto_hash_digestsize(tfm);
                        int_dig_in = kmalloc(hash_size, GFP_KERNEL);
                        int_dig_vv = kmalloc(hash_size, GFP_KERNEL);
                        if (!(int_dig_in && int_dig_vv)) {
-                               crypto_free_hash(tfm);
+                               conn_err(tconn, "Allocation of buffers for data integrity checking failed\n");
                                goto disconnect;
                        }
                }
 
-               if (tconn->peer_integrity_tfm)
-                       crypto_free_hash(tconn->peer_integrity_tfm);
-               tconn->peer_integrity_tfm = tfm;
+               new_net_conf = kmalloc(sizeof(struct net_conf), GFP_KERNEL);
+               if (!new_net_conf) {
+                       conn_err(tconn, "Allocation of new net_conf failed\n");
+                       goto disconnect;
+               }
+
+               mutex_lock(&tconn->data.mutex);
+               mutex_lock(&tconn->conf_update);
+               old_net_conf = tconn->net_conf;
+               *new_net_conf = *old_net_conf;
+
+               new_net_conf->wire_protocol = p_proto;
+               new_net_conf->after_sb_0p = convert_after_sb(p_after_sb_0p);
+               new_net_conf->after_sb_1p = convert_after_sb(p_after_sb_1p);
+               new_net_conf->after_sb_2p = convert_after_sb(p_after_sb_2p);
+               new_net_conf->two_primaries = p_two_primaries;
+               strcpy(new_net_conf->integrity_alg, integrity_alg);
+               new_net_conf->integrity_alg_len = strlen(integrity_alg) + 1;
+
+               crypto_free_hash(tconn->integrity_tfm);
+               tconn->integrity_tfm = tfm;
+
+               rcu_assign_pointer(tconn->net_conf, new_net_conf);
+               mutex_unlock(&tconn->conf_update);
+               mutex_unlock(&tconn->data.mutex);
+
+               crypto_free_hash(tconn->peer_integrity_tfm);
                kfree(tconn->int_dig_in);
                kfree(tconn->int_dig_vv);
+               tconn->peer_integrity_tfm = peer_tfm;
                tconn->int_dig_in = int_dig_in;
                tconn->int_dig_vv = int_dig_vv;
+
+               if (strcmp(old_net_conf->integrity_alg, integrity_alg))
+                       conn_info(tconn, "peer data-integrity-alg: %s\n", integrity_alg);
+
+               synchronize_rcu();
+               kfree(old_net_conf);
+
+               return 0;
        }
 
        clear_bit(CONN_DRY_RUN, &tconn->flags);
@@ -3063,7 +3098,7 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
        rcu_read_lock();
        nc = rcu_dereference(tconn->net_conf);
 
-       if (p_proto != nc->wire_protocol && tconn->agreed_pro_version < 100) {
+       if (p_proto != nc->wire_protocol) {
                conn_err(tconn, "incompatible communication protocols\n");
                goto disconnect_rcu_unlock;
        }
@@ -3093,6 +3128,11 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
                goto disconnect_rcu_unlock;
        }
 
+       if (strcmp(integrity_alg, nc->integrity_alg)) {
+               conn_err(tconn, "incompatible setting of the data-integrity-alg\n");
+               goto disconnect_rcu_unlock;
+       }
+
        rcu_read_unlock();
 
        return 0;
@@ -3100,6 +3140,10 @@ static int receive_protocol(struct drbd_tconn *tconn, struct packet_info *pi)
 disconnect_rcu_unlock:
        rcu_read_unlock();
 disconnect:
+       crypto_free_hash(peer_tfm);
+       crypto_free_hash(tfm);
+       kfree(int_dig_in);
+       kfree(int_dig_vv);
        conn_request_state(tconn, NS(conn, C_DISCONNECTING), CS_HARD);
        return -EIO;
 }
@@ -4197,6 +4241,7 @@ static struct data_cmd drbd_cmd_handler[] = {
        [P_DELAY_PROBE]     = { 0, sizeof(struct p_delay_probe93), receive_skip },
        [P_OUT_OF_SYNC]     = { 0, sizeof(struct p_block_desc), receive_out_of_sync },
        [P_CONN_ST_CHG_REQ] = { 0, sizeof(struct p_req_state), receive_req_conn_state },
+       [P_PROTOCOL_UPDATE] = { 1, sizeof(struct p_protocol), receive_protocol },
 };
 
 static void drbdd(struct drbd_tconn *tconn)