From 47af22a5937c762ac63a7cd0dd28dc41037e5dda Mon Sep 17 00:00:00 2001
From: Philipp Reisner <philipp.reisner@linbit.com>
Date: Thu, 30 Jun 2011 15:43:06 +0200
Subject: [PATCH] --- yaml --- r: 346095 b: refs/heads/master c:
 2ffca4f3ee6c2d507c39689e5f569bcb0612d3ad h: refs/heads/master i:   346093:
 4490563d1106fdfad1e4c853882ccc3fe878b897   346091:
 3143b742408846a7e9940d608067478cadd33446   346087:
 a0c9722188709e25457534882954368e5f7d9b8e   346079:
 6d7ad1bcdbc84ad7c68d8e5aa12b061c4f30aa31 v: v3

---
 [refs]                               | 2 +-
 trunk/drivers/block/drbd/drbd_int.h  | 3 ++-
 trunk/drivers/block/drbd/drbd_main.c | 6 ++++++
 trunk/drivers/block/drbd/drbd_nl.c   | 7 +++++--
 4 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 2ef7f3c7cef5..c4803a1d0af4 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d942ae44537669418a7cbfd916531d30513dbca8
+refs/heads/master: 2ffca4f3ee6c2d507c39689e5f569bcb0612d3ad
diff --git a/trunk/drivers/block/drbd/drbd_int.h b/trunk/drivers/block/drbd/drbd_int.h
index 1d71b3a3586a..6035784f0de3 100644
--- a/trunk/drivers/block/drbd/drbd_int.h
+++ b/trunk/drivers/block/drbd/drbd_int.h
@@ -1284,7 +1284,8 @@ struct bm_extent {
 #endif
 #define DRBD_MAX_BIO_SIZE_SAFE (1 << 12)       /* Works always = 4k */
 
-#define DRBD_MAX_SIZE_H80_PACKET (1 << 15) /* The old header only allows packets up to 32Kib data */
+#define DRBD_MAX_SIZE_H80_PACKET (1 << 15) /* Header 80 only allows packets up to 32KiB data */
+#define DRBD_MAX_BIO_SIZE_P95    (1 << 17) /* Protocol 95 to 99 allows bios up to 128KiB */
 
 extern int  drbd_bm_init(struct drbd_conf *mdev);
 extern int  drbd_bm_resize(struct drbd_conf *mdev, sector_t sectors, int set_new_bits);
diff --git a/trunk/drivers/block/drbd/drbd_main.c b/trunk/drivers/block/drbd/drbd_main.c
index 72b1dfa4b656..448de7bf8223 100644
--- a/trunk/drivers/block/drbd/drbd_main.c
+++ b/trunk/drivers/block/drbd/drbd_main.c
@@ -1075,6 +1075,12 @@ int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags fl
 	p = drbd_prepare_command(mdev, sock);
 	if (!p)
 		return -EIO;
+
+	if (mdev->tconn->agreed_pro_version <= 94)
+		max_bio_size = min_t(int, max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
+	else if (mdev->tconn->agreed_pro_version < 100)
+		max_bio_size = min_t(int, max_bio_size, DRBD_MAX_BIO_SIZE_P95);
+
 	p->d_size = cpu_to_be64(d_size);
 	p->u_size = cpu_to_be64(u_size);
 	p->c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(mdev->this_bdev));
diff --git a/trunk/drivers/block/drbd/drbd_nl.c b/trunk/drivers/block/drbd/drbd_nl.c
index f92346296ae3..838c3cd54cdd 100644
--- a/trunk/drivers/block/drbd/drbd_nl.c
+++ b/trunk/drivers/block/drbd/drbd_nl.c
@@ -1062,10 +1062,13 @@ void drbd_reconsider_max_bio_size(struct drbd_conf *mdev)
 	   BIOs for a single peer_request */
 	if (mdev->state.conn >= C_CONNECTED) {
 		if (mdev->tconn->agreed_pro_version < 94)
-			peer = mdev->peer_max_bio_size;
+			peer = min_t(int, mdev->peer_max_bio_size, DRBD_MAX_SIZE_H80_PACKET);
+			/* Correct old drbd (up to 8.3.7) if it believes it can do more than 32KiB */
 		else if (mdev->tconn->agreed_pro_version == 94)
 			peer = DRBD_MAX_SIZE_H80_PACKET;
-		else /* drbd 8.3.8 onwards */
+		else if (mdev->tconn->agreed_pro_version < 100)
+			peer = DRBD_MAX_BIO_SIZE_P95;  /* drbd 8.3.8 onwards, before 8.4.0 */
+		else
 			peer = DRBD_MAX_BIO_SIZE;
 	}