This is a note to let you know that I've just added the patch titled RDS: RDMA: Fix the composite message user notification to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rds-rdma-fix-the-composite-message-user-notification.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Oct 5 10:49:14 CEST 2017 From: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx> Date: Thu, 18 Feb 2016 20:06:47 -0800 Subject: RDS: RDMA: Fix the composite message user notification From: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx> [ Upstream commit 941f8d55f6d613a460a5e080d25a38509f45eb75 ] When application sends an RDS RDMA composite message consist of RDMA transfer to be followed up by non RDMA payload, it expect to be notified *only* when the full message gets delivered. RDS RDMA notification doesn't behave this way though. Thanks to Venkat for debug and root casuing the issue where only first part of the message(RDMA) was successfully delivered but remainder payload delivery failed. In that case, application should not be notified with a false positive of message delivery success. Fix this case by making sure the user gets notified only after the full message delivery. Reviewed-by: Venkat Venkatsubra <venkat.x.venkatsubra@xxxxxxxxxx> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/rds/ib_send.c | 25 +++++++++++++++---------- net/rds/rdma.c | 10 ++++++++++ net/rds/rds.h | 1 + net/rds/send.c | 4 +++- 4 files changed, 29 insertions(+), 11 deletions(-) --- a/net/rds/ib_send.c +++ b/net/rds/ib_send.c @@ -68,16 +68,6 @@ static void rds_ib_send_complete(struct complete(rm, notify_status); } -static void rds_ib_send_unmap_data(struct rds_ib_connection *ic, - struct rm_data_op *op, - int wc_status) -{ - if (op->op_nents) - ib_dma_unmap_sg(ic->i_cm_id->device, - op->op_sg, op->op_nents, - DMA_TO_DEVICE); -} - static void rds_ib_send_unmap_rdma(struct rds_ib_connection *ic, struct rm_rdma_op *op, int wc_status) @@ -138,6 +128,21 @@ static void rds_ib_send_unmap_atomic(str rds_ib_stats_inc(s_ib_atomic_fadd); } +static void rds_ib_send_unmap_data(struct rds_ib_connection *ic, + struct rm_data_op *op, + int wc_status) +{ + struct rds_message *rm = container_of(op, struct rds_message, data); + + if (op->op_nents) + ib_dma_unmap_sg(ic->i_cm_id->device, + op->op_sg, op->op_nents, + DMA_TO_DEVICE); + + if (rm->rdma.op_active && rm->data.op_notify) + rds_ib_send_unmap_rdma(ic, &rm->rdma, wc_status); +} + /* * Unmap the resources associated with a struct send_work. * --- a/net/rds/rdma.c +++ b/net/rds/rdma.c @@ -626,6 +626,16 @@ int rds_cmsg_rdma_args(struct rds_sock * } op->op_notifier->n_user_token = args->user_token; op->op_notifier->n_status = RDS_RDMA_SUCCESS; + + /* Enable rmda notification on data operation for composite + * rds messages and make sure notification is enabled only + * for the data operation which follows it so that application + * gets notified only after full message gets delivered. + */ + if (rm->data.op_sg) { + rm->rdma.op_notify = 0; + rm->data.op_notify = !!(args->flags & RDS_RDMA_NOTIFY_ME); + } } /* The cookie contains the R_Key of the remote memory region, and --- a/net/rds/rds.h +++ b/net/rds/rds.h @@ -378,6 +378,7 @@ struct rds_message { } rdma; struct rm_data_op { unsigned int op_active:1; + unsigned int op_notify:1; unsigned int op_nents; unsigned int op_count; unsigned int op_dmasg; --- a/net/rds/send.c +++ b/net/rds/send.c @@ -467,12 +467,14 @@ void rds_rdma_send_complete(struct rds_m struct rm_rdma_op *ro; struct rds_notifier *notifier; unsigned long flags; + unsigned int notify = 0; spin_lock_irqsave(&rm->m_rs_lock, flags); + notify = rm->rdma.op_notify | rm->data.op_notify; ro = &rm->rdma; if (test_bit(RDS_MSG_ON_SOCK, &rm->m_flags) && - ro->op_active && ro->op_notify && ro->op_notifier) { + ro->op_active && notify && ro->op_notifier) { notifier = ro->op_notifier; rs = rm->m_rs; sock_hold(rds_rs_to_sk(rs)); Patches currently in stable-queue which might be from santosh.shilimkar@xxxxxxxxxx are queue-4.4/rds-ib-add-error-handle.patch queue-4.4/rds-rdma-fix-the-composite-message-user-notification.patch