drbd: New packet for Ahead/Behind mode: P_OUT_OF_SYNC

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

7 files changed, 90 insertions, 18 deletions

diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index b4adb58c7472..33f6cc537d08 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -1007,22 +1007,22 @@ void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector, int size,
  * called by tl_clear and drbd_send_dblock (==drbd_make_request).
  * so this can be _any_ process.
  */
-void __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
+int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
                             const char *file, const unsigned int line)
 {
         unsigned long sbnr, ebnr, lbnr, flags;
         sector_t esector, nr_sectors;
-        unsigned int enr, count;
+        unsigned int enr, count = 0;
         struct lc_element *e;
 
         if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
                 dev_err(DEV, "sector: %llus, size: %d\n",
                         (unsigned long long)sector, size);
-                return;
+                return 0;
         }
 
         if (!get_ldev(mdev))
-                return; /* no disk, no metadata, no bitmap to set bits in */
+                return 0; /* no disk, no metadata, no bitmap to set bits in */
 
         nr_sectors = drbd_get_capacity(mdev->this_bdev);
         esector = sector + (size >> 9) - 1;
@@ -1052,6 +1052,8 @@ void __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
 
 out:
         put_ldev(mdev);
+
+        return count;
 }
 
 static
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 21b7439438cd..471331236826 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -212,6 +212,7 @@ enum drbd_packets {
         /* P_CKPT_FENCE_REQ      = 0x25, * currently reserved for protocol D */
         /* P_CKPT_DISABLE_REQ    = 0x26, * currently reserved for protocol D */
         P_DELAY_PROBE         = 0x27, /* is used on BOTH sockets */
+        P_OUT_OF_SYNC         = 0x28, /* Mark as out of sync (Outrunning), data socket */
 
         P_MAX_CMD             = 0x28,
         P_MAY_IGNORE          = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
@@ -269,6 +270,7 @@ static inline const char *cmdname(enum drbd_packets cmd)
                 [P_RS_IS_IN_SYNC]       = "CsumRSIsInSync",
                 [P_COMPRESSED_BITMAP]   = "CBitmap",
                 [P_DELAY_PROBE]         = "DelayProbe",
+                [P_OUT_OF_SYNC]         = "OutOfSync",
                 [P_MAX_CMD]             = NULL,
         };
 
@@ -550,6 +552,13 @@ struct p_discard {
         u32         pad;
 } __packed;
 
+struct p_block_desc {
+        struct p_header80 head;
+        u64 sector;
+        u32 blksize;
+        u32 pad;        /* to multiple of 8 Byte */
+} __packed;
+
 /* Valid values for the encoding field.
  * Bump proto version when changing this. */
 enum drbd_bitmap_code {
@@ -647,6 +656,7 @@ union p_polymorph {
         struct p_block_req       block_req;
         struct p_delay_probe93   delay_probe93;
         struct p_rs_uuid         rs_uuid;
+        struct p_block_desc      block_desc;
 } __packed;
 
 /**********************************************************************/
@@ -1221,6 +1231,7 @@ extern int drbd_send_ack_dp(struct drbd_conf *mdev, enum drbd_packets cmd,
                         struct p_data *dp, int data_size);
 extern int drbd_send_ack_ex(struct drbd_conf *mdev, enum drbd_packets cmd,
                             sector_t sector, int blksize, u64 block_id);
+extern int drbd_send_oos(struct drbd_conf *mdev, struct drbd_request *req);
 extern int drbd_send_block(struct drbd_conf *mdev, enum drbd_packets cmd,
                            struct drbd_epoch_entry *e);
 extern int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req);
@@ -1534,6 +1545,7 @@ extern int w_send_read_req(struct drbd_conf *, struct drbd_work *, int);
 extern int w_prev_work_done(struct drbd_conf *, struct drbd_work *, int);
 extern int w_e_reissue(struct drbd_conf *, struct drbd_work *, int);
 extern int w_restart_disk_io(struct drbd_conf *, struct drbd_work *, int);
+extern int w_send_oos(struct drbd_conf *, struct drbd_work *, int);
 
 extern void resync_timer_fn(unsigned long data);
 
@@ -1626,7 +1638,7 @@ extern void __drbd_set_in_sync(struct drbd_conf *mdev, sector_t sector,
                 int size, const char *file, const unsigned int line);
 #define drbd_set_in_sync(mdev, sector, size) \
         __drbd_set_in_sync(mdev, sector, size, __FILE__, __LINE__)
-extern void __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector,
+extern int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector,
                 int size, const char *file, const unsigned int line);
 #define drbd_set_out_of_sync(mdev, sector, size) \
         __drbd_set_out_of_sync(mdev, sector, size, __FILE__, __LINE__)
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 46f27d6c0b21..0dc93f43a476 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2634,6 +2634,16 @@ int drbd_send_block(struct drbd_conf *mdev, enum drbd_packets cmd,
         return ok;
 }
 
+int drbd_send_oos(struct drbd_conf *mdev, struct drbd_request *req)
+{
+        struct p_block_desc p;
+
+        p.sector  = cpu_to_be64(req->sector);
+        p.blksize = cpu_to_be32(req->size);
+
+        return drbd_send_cmd(mdev, USE_DATA_SOCKET, P_OUT_OF_SYNC, &p.head, sizeof(p));
+}
+
 /*
   drbd_send distinguishes two cases:
 
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index b19e8b2c4ce5..04a08e7541cc 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3562,6 +3562,15 @@ static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packets cmd, u
         return TRUE;
 }
 
+static int receive_out_of_sync(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
+{
+        struct p_block_desc *p = &mdev->data.rbuf.block_desc;
+
+        drbd_set_out_of_sync(mdev, be64_to_cpu(p->sector), be32_to_cpu(p->blksize));
+
+        return TRUE;
+}
+
 typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, enum drbd_packets cmd, unsigned int to_receive);
 
 struct data_cmd {
@@ -3592,6 +3601,7 @@ static struct data_cmd drbd_cmd_handler[] = {
         [P_OV_REPLY]        = { 1, sizeof(struct p_block_req), receive_DataRequest },
         [P_CSUM_RS_REQUEST] = { 1, sizeof(struct p_block_req), receive_DataRequest },
         [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 },
         /* anything missing from this table is in
          * the asender_tbl, see get_asender_cmd */
         [P_MAX_CMD]         = { 0, 0, NULL },
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 60288fb3c4d7..a8d1ff2bda27 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -142,7 +142,7 @@ static void _about_to_complete_local_write(struct drbd_conf *mdev,
 
         /* before we can signal completion to the upper layers,
          * we may need to close the current epoch */
-        if (mdev->state.conn >= C_CONNECTED &&
+        if (mdev->state.conn >= C_CONNECTED && mdev->state.conn < C_AHEAD &&
             req->epoch == mdev->newest_tle->br_number)
                 queue_barrier(mdev);
 
@@ -545,6 +545,14 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
 
                 break;
 
+        case queue_for_send_oos:
+                req->rq_state |= RQ_NET_QUEUED;
+                req->w.cb =  w_send_oos;
+                drbd_queue_work(&mdev->data.work, &req->w);
+                break;
+
+        case oos_handed_to_network:
+                /* actually the same */
         case send_canceled:
                 /* treat it the same */
         case send_failed:
@@ -756,7 +764,7 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio)
         const sector_t sector = bio->bi_sector;
         struct drbd_tl_epoch *b = NULL;
         struct drbd_request *req;
-        int local, remote;
+        int local, remote, send_oos = 0;
         int err = -EIO;
         int ret = 0;
 
@@ -820,8 +828,11 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio)
         }
 
         remote = remote && (mdev->state.pdsk == D_UP_TO_DATE ||
-                            (mdev->state.pdsk == D_INCONSISTENT &&
-                             mdev->state.conn >= C_CONNECTED));
+                            (mdev->state.pdsk >= D_INCONSISTENT &&
+                             mdev->state.conn >= C_CONNECTED &&
+                             mdev->state.conn < C_AHEAD));
+        send_oos = (rw == WRITE && mdev->state.conn == C_AHEAD &&
+                    mdev->state.pdsk >= D_INCONSISTENT);
 
         if (!(local || remote) && !is_susp(mdev->state)) {
                 if (__ratelimit(&drbd_ratelimit_state))
@@ -835,7 +846,7 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio)
          * but there is a race between testing the bit and pointer outside the
          * spinlock, and grabbing the spinlock.
          * if we lost that race, we retry.  */
-        if (rw == WRITE && remote &&
+        if (rw == WRITE && (remote || send_oos) &&
             mdev->unused_spare_tle == NULL &&
             test_bit(CREATE_BARRIER, &mdev->flags)) {
 allocate_barrier:
@@ -860,11 +871,15 @@ allocate_barrier:
                 goto fail_free_complete;
         }
 
-        if (remote) {
+        if (remote || send_oos) {
                 remote = (mdev->state.pdsk == D_UP_TO_DATE ||
-                            (mdev->state.pdsk == D_INCONSISTENT &&
-                             mdev->state.conn >= C_CONNECTED));
-                if (!remote)
+                            (mdev->state.pdsk >= D_INCONSISTENT &&
+                             mdev->state.conn >= C_CONNECTED &&
+                             mdev->state.conn < C_AHEAD));
+                send_oos = (rw == WRITE && mdev->state.conn == C_AHEAD &&
+                            mdev->state.pdsk >= D_INCONSISTENT);
+
+                if (!(remote || send_oos))
                         dev_warn(DEV, "lost connection while grabbing the req_lock!\n");
                 if (!(local || remote)) {
                         dev_err(DEV, "IO ERROR: neither local nor remote disk\n");
@@ -877,7 +892,7 @@ allocate_barrier:
                 mdev->unused_spare_tle = b;
                 b = NULL;
         }
-        if (rw == WRITE && remote &&
+        if (rw == WRITE && (remote || send_oos) &&
             mdev->unused_spare_tle == NULL &&
             test_bit(CREATE_BARRIER, &mdev->flags)) {
                 /* someone closed the current epoch
@@ -900,7 +915,7 @@ allocate_barrier:
          * barrier packet.  To get the write ordering right, we only have to
          * make sure that, if this is a write request and it triggered a
          * barrier packet, this request is queued within the same spinlock. */
-        if (remote && mdev->unused_spare_tle &&
+        if ((remote || send_oos) && mdev->unused_spare_tle &&
             test_and_clear_bit(CREATE_BARRIER, &mdev->flags)) {
                 _tl_add_barrier(mdev, mdev->unused_spare_tle);
                 mdev->unused_spare_tle = NULL;
@@ -948,8 +963,11 @@ allocate_barrier:
                                 ? queue_for_net_write
                                 : queue_for_net_read);
         }
+        if (send_oos && drbd_set_out_of_sync(mdev, sector, size))
+                _req_mod(req, queue_for_send_oos);
 
-        if (remote && mdev->net_conf->on_congestion != OC_BLOCK) {
+        if (remote &&
+            mdev->net_conf->on_congestion != OC_BLOCK && mdev->agreed_pro_version >= 96) {
                 int congested = 0;
 
                 if (mdev->net_conf->cong_fill &&
@@ -964,6 +982,8 @@ allocate_barrier:
                 }
 
                 if (congested) {
+                        queue_barrier(mdev);
+
                         if (mdev->net_conf->on_congestion == OC_PULL_AHEAD)
                                 _drbd_set_state(_NS(mdev, conn, C_AHEAD), 0, NULL);
                         else  /*mdev->net_conf->on_congestion == OC_DISCONNECT */
diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index 69d350fe7c1e..40d3dcd8fc81 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -82,14 +82,16 @@ enum drbd_req_event {
         to_be_submitted,
 
         /* XXX yes, now I am inconsistent...
-         * these two are not "events" but "actions"
+         * these are not "events" but "actions"
          * oh, well... */
         queue_for_net_write,
         queue_for_net_read,
+        queue_for_send_oos,
 
         send_canceled,
         send_failed,
         handed_over_to_network,
+        oos_handed_to_network,
         connection_lost_while_pending,
         read_retry_remote_canceled,
         recv_acked_by_peer,
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 782d87237cb4..67499077c482 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1237,6 +1237,22 @@ int w_send_write_hint(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
         return drbd_send_short_cmd(mdev, P_UNPLUG_REMOTE);
 }
 
+int w_send_oos(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
+{
+        struct drbd_request *req = container_of(w, struct drbd_request, w);
+        int ok;
+
+        if (unlikely(cancel)) {
+                req_mod(req, send_canceled);
+                return 1;
+        }
+
+        ok = drbd_send_oos(mdev, req);
+        req_mod(req, oos_handed_to_network);
+
+        return ok;
+}
+
 /**
  * w_send_dblock() - Worker callback to send a P_DATA packet in order to mirror a write request
  * @mdev:       DRBD device.