From 8979d9c9e0bc8e54cf5bd7a89abb2145f087b5e1 Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Tue, 14 Sep 2010 15:56:29 +0200 Subject: [PATCH] drbd: protocol compatibility for maximum packet sizes Two missing corner cases to the "maximum packet size" handshake. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_nl.c | 18 +++++++++++++++--- drivers/block/drbd/drbd_receiver.c | 2 ++ 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 9ee44568dce3..9ae33a5bcf66 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -861,6 +861,7 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp struct inode *inode, *inode2; struct lru_cache *resync_lru = NULL; union drbd_state ns, os; + unsigned int max_seg_s; int rv; int cp_discovered = 0; int logical_block_size; @@ -1133,9 +1134,20 @@ static int drbd_nl_disk_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp mdev->read_cnt = 0; mdev->writ_cnt = 0; - drbd_setup_queue_param(mdev, mdev->state.conn == C_CONNECTED && - mdev->agreed_pro_version < 95 ? - DRBD_MAX_SIZE_H80_PACKET : DRBD_MAX_SEGMENT_SIZE); + max_seg_s = DRBD_MAX_SEGMENT_SIZE; + if (mdev->state.conn == C_CONNECTED) { + /* We are Primary, Connected, and now attach a new local + * backing store. We must not increase the user visible maximum + * bio size on this device to something the peer may not be + * able to handle. */ + if (mdev->agreed_pro_version < 94) + max_seg_s = queue_max_segment_size(mdev->rq_queue); + else if (mdev->agreed_pro_version == 94) + max_seg_s = DRBD_MAX_SIZE_H80_PACKET; + /* else: drbd 8.3.9 and later, stay with default */ + } + + drbd_setup_queue_param(mdev, max_seg_s); /* If I am currently not R_PRIMARY, * but meta data primary indicator is set, diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 6b69b2f734dc..9da32ac62c22 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -3088,6 +3088,8 @@ static int receive_sizes(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned if (mdev->agreed_pro_version < 94) max_seg_s = be32_to_cpu(p->max_segment_size); + else if (mdev->agreed_pro_version == 94) + max_seg_s = DRBD_MAX_SIZE_H80_PACKET; else /* drbd 8.3.8 onwards */ max_seg_s = DRBD_MAX_SEGMENT_SIZE;