From: Wen Gu guwen@linux.alibaba.com
mainline inclusion from mainline-v6.10-rc1 commit cc0ab806fc52e77f961b275ebb58024bd0e7adf2 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IACM52
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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If the local sndbuf shares the same physical memory with peer DMB, the cursor update processing needs to be adapted to ensure that the data to be consumed won't be overwritten.
So in this case, the fin_curs and sndbuf_space that were originally updated after sending the CDC message should be modified to not be update until the peer updates cons_curs.
Signed-off-by: Wen Gu guwen@linux.alibaba.com Reviewed-by: Wenjia Zhang wenjia@linux.ibm.com Reviewed-and-tested-by: Jan Karcher jaka@linux.ibm.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Zhengchao Shao shaozhengchao@huawei.com --- net/smc/smc_cdc.c | 36 ++++++++++++++++++++++++++++++++++-- 1 file changed, 34 insertions(+), 2 deletions(-)
diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c index 3c06625ceb20..619b3bab3824 100644 --- a/net/smc/smc_cdc.c +++ b/net/smc/smc_cdc.c @@ -18,6 +18,7 @@ #include "smc_tx.h" #include "smc_rx.h" #include "smc_close.h" +#include "smc_ism.h"
/********************************** send *************************************/
@@ -255,6 +256,14 @@ int smcd_cdc_msg_send(struct smc_connection *conn) return rc; smc_curs_copy(&conn->rx_curs_confirmed, &curs, conn); conn->local_rx_ctrl.prod_flags.cons_curs_upd_req = 0; + + if (smc_ism_support_dmb_nocopy(conn->lgr->smcd)) + /* if local sndbuf shares the same memory region with + * peer DMB, then don't update the tx_curs_fin + * and sndbuf_space until peer has consumed the data. + */ + return 0; + /* Calculate transmitted data and increment free send buffer space */ diff = smc_curs_diff(conn->sndbuf_desc->len, &conn->tx_curs_fin, &conn->tx_curs_sent); @@ -266,7 +275,7 @@ int smcd_cdc_msg_send(struct smc_connection *conn) smc_curs_copy(&conn->tx_curs_fin, &conn->tx_curs_sent, conn);
smc_tx_sndbuf_nonfull(smc); - return rc; + return 0; }
/********************************* receive ***********************************/ @@ -323,7 +332,7 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, { union smc_host_cursor cons_old, prod_old; struct smc_connection *conn = &smc->conn; - int diff_cons, diff_prod; + int diff_cons, diff_prod, diff_tx;
smc_curs_copy(&prod_old, &conn->local_rx_ctrl.prod, conn); smc_curs_copy(&cons_old, &conn->local_rx_ctrl.cons, conn); @@ -339,6 +348,29 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc, atomic_add(diff_cons, &conn->peer_rmbe_space); /* guarantee 0 <= peer_rmbe_space <= peer_rmbe_size */ smp_mb__after_atomic(); + + /* if local sndbuf shares the same memory region with + * peer RMB, then update tx_curs_fin and sndbuf_space + * here since peer has already consumed the data. + */ + if (conn->lgr->is_smcd && + smc_ism_support_dmb_nocopy(conn->lgr->smcd)) { + /* Calculate consumed data and + * increment free send buffer space. + */ + diff_tx = smc_curs_diff(conn->sndbuf_desc->len, + &conn->tx_curs_fin, + &conn->local_rx_ctrl.cons); + /* increase local sndbuf space and fin_curs */ + smp_mb__before_atomic(); + atomic_add(diff_tx, &conn->sndbuf_space); + /* guarantee 0 <= sndbuf_space <= sndbuf_desc->len */ + smp_mb__after_atomic(); + smc_curs_copy(&conn->tx_curs_fin, + &conn->local_rx_ctrl.cons, conn); + + smc_tx_sndbuf_nonfull(smc); + } }
diff_prod = smc_curs_diff(conn->rmb_desc->len, &prod_old,