drbd: --dry-run option for drbdsetup net ( drbdadm -- --dry-run connect <res> )

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 2bf3a6e..1aae724 100644 (file)
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -443,13 +443,18 @@ struct p_rs_param_89 {
        char csums_alg[SHARED_SECRET_MAX];
 } __packed;
 
+enum drbd_conn_flags {
+       CF_WANT_LOSE = 1,
+       CF_DRY_RUN = 2,
+};
+
 struct p_protocol {
        struct p_header head;
        u32 protocol;
        u32 after_sb_0p;
        u32 after_sb_1p;
        u32 after_sb_2p;
-       u32 want_lose;
+       u32 conn_flags;
        u32 two_primaries;
 
               /* Since protocol version 87 and higher. */
@@ -791,6 +796,7 @@ enum {
                                 * while this is set. */
        RESIZE_PENDING,         /* Size change detected locally, waiting for the response from
                                 * the peer, if it changed there as well. */
+       CONN_DRY_RUN,           /* Expect disconnect after resync handshake. */
 };
 
 struct drbd_bitmap; /* opaque for drbd_conf */

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index ab871e0..b2d347d 100644 (file)
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1668,7 +1668,7 @@ int drbd_send_sync_param(struct drbd_conf *mdev, struct syncer_conf *sc)
 int drbd_send_protocol(struct drbd_conf *mdev)
 {
        struct p_protocol *p;
-       int size, rv;
+       int size, cf, rv;
 
        size = sizeof(struct p_protocol);
 
@@ -1685,9 +1685,21 @@ int drbd_send_protocol(struct drbd_conf *mdev)
        p->after_sb_0p   = cpu_to_be32(mdev->net_conf->after_sb_0p);
        p->after_sb_1p   = cpu_to_be32(mdev->net_conf->after_sb_1p);
        p->after_sb_2p   = cpu_to_be32(mdev->net_conf->after_sb_2p);
-       p->want_lose     = cpu_to_be32(mdev->net_conf->want_lose);
        p->two_primaries = cpu_to_be32(mdev->net_conf->two_primaries);
 
+       cf = 0;
+       if (mdev->net_conf->want_lose)
+               cf |= CF_WANT_LOSE;
+       if (mdev->net_conf->dry_run) {
+               if (mdev->agreed_pro_version >= 92)
+                       cf |= CF_DRY_RUN;
+               else {
+                       dev_err(DEV, "--dry-run is not supported by peer");
+                       return 0;
+               }
+       }
+       p->conn_flags    = cpu_to_be32(cf);
+
        if (mdev->agreed_pro_version >= 87)
                strcpy(p->integrity_alg, mdev->net_conf->integrity_alg);
 

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index d065c64..8bcde4a 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -2538,6 +2538,16 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol
                }
        }
 
+       if (mdev->net_conf->dry_run || test_bit(CONN_DRY_RUN, &mdev->flags)) {
+               if (hg == 0)
+                       dev_info(DEV, "dry-run connect: No resync, would become Connected immediately.\n");
+               else
+                       dev_info(DEV, "dry-run connect: Would become %s, doing a %s resync.",
+                                drbd_conn_str(hg > 0 ? C_SYNC_SOURCE : C_SYNC_TARGET),
+                                abs(hg) >= 2 ? "full" : "bit-map based");
+               return C_MASK;
+       }
+
        if (abs(hg) >= 2) {
                dev_info(DEV, "Writing the whole bitmap, full sync required after drbd_sync_handshake.\n");
                if (drbd_bitmap_io(mdev, &drbd_bmio_set_n_write, "set_n_write from sync_handshake"))
@@ -2585,7 +2595,7 @@ static int receive_protocol(struct drbd_conf *mdev, struct p_header *h)
        struct p_protocol *p = (struct p_protocol *)h;
        int header_size, data_size;
        int p_proto, p_after_sb_0p, p_after_sb_1p, p_after_sb_2p;
-       int p_want_lose, p_two_primaries;
+       int p_want_lose, p_two_primaries, cf;
        char p_integrity_alg[SHARED_SECRET_MAX] = "";
 
        header_size = sizeof(*p) - sizeof(*h);
@@ -2598,8 +2608,14 @@ static int receive_protocol(struct drbd_conf *mdev, struct p_header *h)
        p_after_sb_0p   = be32_to_cpu(p->after_sb_0p);
        p_after_sb_1p   = be32_to_cpu(p->after_sb_1p);
        p_after_sb_2p   = be32_to_cpu(p->after_sb_2p);
-       p_want_lose     = be32_to_cpu(p->want_lose);
        p_two_primaries = be32_to_cpu(p->two_primaries);
+       cf              = be32_to_cpu(p->conn_flags);
+       p_want_lose = cf & CF_WANT_LOSE;
+
+       clear_bit(CONN_DRY_RUN, &mdev->flags);
+
+       if (cf & CF_DRY_RUN)
+               set_bit(CONN_DRY_RUN, &mdev->flags);
 
        if (p_proto != mdev->net_conf->wire_protocol) {
                dev_err(DEV, "incompatible communication protocols\n");
@@ -3125,6 +3141,8 @@ static int receive_state(struct drbd_conf *mdev, struct p_header *h)
                                dev_err(DEV, "Disk attach process on the peer node was aborted.\n");
                                peer_state.disk = D_DISKLESS;
                        } else {
+                               if (test_and_clear_bit(CONN_DRY_RUN, &mdev->flags))
+                                       return FALSE;
                                D_ASSERT(oconn == C_WF_REPORT_PARAMS);
                                drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
                                return FALSE;

diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 7896227..4341b1a 100644 (file)
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -56,7 +56,7 @@ extern const char *drbd_buildtag(void);
 #define REL_VERSION "8.3.7"
 #define API_VERSION 88
 #define PRO_VERSION_MIN 86
-#define PRO_VERSION_MAX 91
+#define PRO_VERSION_MAX 92
 
 
 enum drbd_io_error_p {

diff --git a/include/linux/drbd_nl.h b/include/linux/drbd_nl.h
index a4d82f8..b41050e 100644 (file)
--- a/include/linux/drbd_nl.h
+++ b/include/linux/drbd_nl.h
@@ -63,6 +63,7 @@ NL_PACKET(net_conf, 5,
        NL_BIT(         41,     T_MAY_IGNORE,   always_asbp)
        NL_BIT(         61,     T_MAY_IGNORE,   no_cork)
        NL_BIT(         62,     T_MANDATORY,    auto_sndbuf_size)
+       NL_BIT(         70,     T_MANDATORY,    dry_run)
 )
 
 NL_PACKET(disconnect, 6, )