[net-next,v2,01/11] net/smc: improved fix wait on already cleared link

Message ID	20211014164752.3647027-2-kgraul@linux.ibm.com (mailing list archive)
State	Superseded
Headers	show Return-Path: <linux-rdma-owner@kernel.org> From: Karsten Graul <kgraul@linux.ibm.com> To: David Miller <davem@davemloft.net>, Jakub Kicinski <kuba@kernel.org> Cc: netdev@vger.kernel.org, linux-s390@vger.kernel.org, Heiko Carstens <hca@linux.ibm.com>, linux-rdma@vger.kernel.org Subject: [PATCH net-next v2 01/11] net/smc: improved fix wait on already cleared link Date: Thu, 14 Oct 2021 18:47:42 +0200 Message-Id: <20211014164752.3647027-2-kgraul@linux.ibm.com> In-Reply-To: <20211014164752.3647027-1-kgraul@linux.ibm.com> References: <20211014164752.3647027-1-kgraul@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	net/smc: introduce SMC-Rv2 support \| expand [net-next,v2,00/11] net/smc: introduce SMC-Rv2 support [net-next,v2,01/11] net/smc: improved fix wait on already cleared link [net-next,v2,02/11] net/smc: save stack space and allocate smc_init_info [net-next,v2,03/11] net/smc: prepare for SMC-Rv2 connection [net-next,v2,04/11] net/smc: add SMC-Rv2 connection establishment [net-next,v2,05/11] net/smc: add listen processing for SMC-Rv2 [net-next,v2,06/11] net/smc: add v2 format of CLC decline message [net-next,v2,07/11] net/smc: retrieve v2 gid from IB device [net-next,v2,08/11] net/smc: add v2 support to the work request layer [net-next,v2,09/11] net/smc: extend LLC layer for SMC-Rv2 [net-next,v2,10/11] net/smc: add netlink support for SMC-Rv2 [net-next,v2,11/11] net/smc: stop links when their GID is removed

diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c index f23f558054a7..99acd337ba90 100644 --- a/net/smc/smc_cdc.c +++ b/net/smc/smc_cdc.c @@ -150,9 +150,11 @@ static int smcr_cdc_get_slot_and_msg_send(struct smc_connection *conn) again: link = conn->lnk; + if (!smc_wr_tx_link_hold(link)) + return -ENOLINK; rc = smc_cdc_get_free_slot(conn, link, &wr_buf, NULL, &pend); if (rc) - return rc; + goto put_out; spin_lock_bh(&conn->send_lock); if (link != conn->lnk) { @@ -160,6 +162,7 @@ static int smcr_cdc_get_slot_and_msg_send(struct smc_connection *conn) spin_unlock_bh(&conn->send_lock); smc_wr_tx_put_slot(link, (struct smc_wr_tx_pend_priv *)pend); + smc_wr_tx_link_put(link); if (again) return -ENOLINK; again = true; @@ -167,6 +170,8 @@ static int smcr_cdc_get_slot_and_msg_send(struct smc_connection *conn) } rc = smc_cdc_msg_send(conn, wr_buf, pend); spin_unlock_bh(&conn->send_lock); +put_out: + smc_wr_tx_link_put(link); return rc; } diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index f57449089a16..4d463701a759 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -943,7 +943,7 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, to_lnk = &lgr->lnk[i]; break; } - if (!to_lnk) { + if (!to_lnk || !smc_wr_tx_link_hold(to_lnk)) { smc_lgr_terminate_sched(lgr); return NULL; } @@ -975,24 +975,26 @@ struct smc_link *smc_switch_conns(struct smc_link_group *lgr, read_unlock_bh(&lgr->conns_lock); /* pre-fetch buffer outside of send_lock, might sleep */ rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend); - if (rc) { - smcr_link_down_cond_sched(to_lnk); - return NULL; - } + if (rc) + goto err_out; /* avoid race with smcr_tx_sndbuf_nonempty() */ spin_lock_bh(&conn->send_lock); smc_switch_link_and_count(conn, to_lnk); rc = smc_switch_cursor(smc, pend, wr_buf); spin_unlock_bh(&conn->send_lock); sock_put(&smc->sk); - if (rc) { - smcr_link_down_cond_sched(to_lnk); - return NULL; - } + if (rc) + goto err_out; goto again; } read_unlock_bh(&lgr->conns_lock); + smc_wr_tx_link_put(to_lnk); return to_lnk; + +err_out: + smcr_link_down_cond_sched(to_lnk); + smc_wr_tx_link_put(to_lnk); + return NULL; } static void smcr_buf_unuse(struct smc_buf_desc *rmb_desc, diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c index 2e7560eba981..72f4b72eb175 100644 --- a/net/smc/smc_llc.c +++ b/net/smc/smc_llc.c @@ -383,9 +383,11 @@ int smc_llc_send_confirm_link(struct smc_link *link, struct smc_wr_buf *wr_buf; int rc; + if (!smc_wr_tx_link_hold(link)) + return -ENOLINK; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; confllc = (struct smc_llc_msg_confirm_link *)wr_buf; memset(confllc, 0, sizeof(*confllc)); confllc->hd.common.type = SMC_LLC_CONFIRM_LINK; @@ -402,6 +404,8 @@ int smc_llc_send_confirm_link(struct smc_link *link, confllc->max_links = SMC_LLC_ADD_LNK_MAX_LINKS; /* send llc message */ rc = smc_wr_tx_send(link, pend); +put_out: + smc_wr_tx_link_put(link); return rc; } @@ -415,9 +419,11 @@ static int smc_llc_send_confirm_rkey(struct smc_link *send_link, struct smc_link *link; int i, rc, rtok_ix; + if (!smc_wr_tx_link_hold(send_link)) + return -ENOLINK; rc = smc_llc_add_pending_send(send_link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; rkeyllc = (struct smc_llc_msg_confirm_rkey *)wr_buf; memset(rkeyllc, 0, sizeof(*rkeyllc)); rkeyllc->hd.common.type = SMC_LLC_CONFIRM_RKEY; @@ -444,6 +450,8 @@ static int smc_llc_send_confirm_rkey(struct smc_link *send_link, (u64)sg_dma_address(rmb_desc->sgt[send_link->link_idx].sgl)); /* send llc message */ rc = smc_wr_tx_send(send_link, pend); +put_out: + smc_wr_tx_link_put(send_link); return rc; } @@ -456,9 +464,11 @@ static int smc_llc_send_delete_rkey(struct smc_link *link, struct smc_wr_buf *wr_buf; int rc; + if (!smc_wr_tx_link_hold(link)) + return -ENOLINK; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; rkeyllc = (struct smc_llc_msg_delete_rkey *)wr_buf; memset(rkeyllc, 0, sizeof(*rkeyllc)); rkeyllc->hd.common.type = SMC_LLC_DELETE_RKEY; @@ -467,6 +477,8 @@ static int smc_llc_send_delete_rkey(struct smc_link *link, rkeyllc->rkey[0] = htonl(rmb_desc->mr_rx[link->link_idx]->rkey); /* send llc message */ rc = smc_wr_tx_send(link, pend); +put_out: + smc_wr_tx_link_put(link); return rc; } @@ -480,9 +492,11 @@ int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[], struct smc_wr_buf *wr_buf; int rc; + if (!smc_wr_tx_link_hold(link)) + return -ENOLINK; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; addllc = (struct smc_llc_msg_add_link *)wr_buf; memset(addllc, 0, sizeof(*addllc)); @@ -504,6 +518,8 @@ int smc_llc_send_add_link(struct smc_link *link, u8 mac[], u8 gid[], } /* send llc message */ rc = smc_wr_tx_send(link, pend); +put_out: + smc_wr_tx_link_put(link); return rc; } @@ -517,9 +533,11 @@ int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id, struct smc_wr_buf *wr_buf; int rc; + if (!smc_wr_tx_link_hold(link)) + return -ENOLINK; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; delllc = (struct smc_llc_msg_del_link *)wr_buf; memset(delllc, 0, sizeof(*delllc)); @@ -536,6 +554,8 @@ int smc_llc_send_delete_link(struct smc_link *link, u8 link_del_id, delllc->reason = htonl(reason); /* send llc message */ rc = smc_wr_tx_send(link, pend); +put_out: + smc_wr_tx_link_put(link); return rc; } @@ -547,9 +567,11 @@ static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16]) struct smc_wr_buf *wr_buf; int rc; + if (!smc_wr_tx_link_hold(link)) + return -ENOLINK; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; testllc = (struct smc_llc_msg_test_link *)wr_buf; memset(testllc, 0, sizeof(*testllc)); testllc->hd.common.type = SMC_LLC_TEST_LINK; @@ -557,6 +579,8 @@ static int smc_llc_send_test_link(struct smc_link *link, u8 user_data[16]) memcpy(testllc->user_data, user_data, sizeof(testllc->user_data)); /* send llc message */ rc = smc_wr_tx_send(link, pend); +put_out: + smc_wr_tx_link_put(link); return rc; } @@ -567,13 +591,16 @@ static int smc_llc_send_message(struct smc_link *link, void *llcbuf) struct smc_wr_buf *wr_buf; int rc; - if (!smc_link_usable(link)) + if (!smc_wr_tx_link_hold(link)) return -ENOLINK; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg)); - return smc_wr_tx_send(link, pend); + rc = smc_wr_tx_send(link, pend); +put_out: + smc_wr_tx_link_put(link); + return rc; } /* schedule an llc send on link, may wait for buffers, @@ -586,13 +613,16 @@ static int smc_llc_send_message_wait(struct smc_link *link, void *llcbuf) struct smc_wr_buf *wr_buf; int rc; - if (!smc_link_usable(link)) + if (!smc_wr_tx_link_hold(link)) return -ENOLINK; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; memcpy(wr_buf, llcbuf, sizeof(union smc_llc_msg)); - return smc_wr_tx_send_wait(link, pend, SMC_LLC_WAIT_TIME); + rc = smc_wr_tx_send_wait(link, pend, SMC_LLC_WAIT_TIME); +put_out: + smc_wr_tx_link_put(link); + return rc; } /********************************* receive ***********************************/ @@ -672,9 +702,11 @@ static int smc_llc_add_link_cont(struct smc_link *link, struct smc_buf_desc *rmb; u8 n; + if (!smc_wr_tx_link_hold(link)) + return -ENOLINK; rc = smc_llc_add_pending_send(link, &wr_buf, &pend); if (rc) - return rc; + goto put_out; addc_llc = (struct smc_llc_msg_add_link_cont *)wr_buf; memset(addc_llc, 0, sizeof(*addc_llc)); @@ -706,7 +738,10 @@ static int smc_llc_add_link_cont(struct smc_link *link, addc_llc->hd.length = sizeof(struct smc_llc_msg_add_link_cont); if (lgr->role == SMC_CLNT) addc_llc->hd.flags |= SMC_LLC_FLAG_RESP; - return smc_wr_tx_send(link, pend); + rc = smc_wr_tx_send(link, pend); +put_out: + smc_wr_tx_link_put(link); + return rc; } static int smc_llc_cli_rkey_exchange(struct smc_link *link, diff --git a/net/smc/smc_tx.c b/net/smc/smc_tx.c index c79361dfcdfb..738a4a99c827 100644 --- a/net/smc/smc_tx.c +++ b/net/smc/smc_tx.c @@ -496,7 +496,7 @@ static int smc_tx_rdma_writes(struct smc_connection *conn, /* Wakeup sndbuf consumers from any context (IRQ or process) * since there is more data to transmit; usable snd_wnd as max transmit */ -static int _smcr_tx_sndbuf_nonempty(struct smc_connection *conn) +static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) { struct smc_cdc_producer_flags *pflags = &conn->local_tx_ctrl.prod_flags; struct smc_link *link = conn->lnk; @@ -505,8 +505,11 @@ static int _smcr_tx_sndbuf_nonempty(struct smc_connection *conn) struct smc_wr_buf *wr_buf; int rc; + if (!link || !smc_wr_tx_link_hold(link)) + return -ENOLINK; rc = smc_cdc_get_free_slot(conn, link, &wr_buf, &wr_rdma_buf, &pend); if (rc < 0) { + smc_wr_tx_link_put(link); if (rc == -EBUSY) { struct smc_sock *smc = container_of(conn, struct smc_sock, conn); @@ -547,22 +550,7 @@ static int _smcr_tx_sndbuf_nonempty(struct smc_connection *conn) out_unlock: spin_unlock_bh(&conn->send_lock); - return rc; -} - -static int smcr_tx_sndbuf_nonempty(struct smc_connection *conn) -{ - struct smc_link *link = conn->lnk; - int rc = -ENOLINK; - - if (!link) - return rc; - - atomic_inc(&link->wr_tx_refcnt); - if (smc_link_usable(link)) - rc = _smcr_tx_sndbuf_nonempty(conn); - if (atomic_dec_and_test(&link->wr_tx_refcnt)) - wake_up_all(&link->wr_tx_wait); + smc_wr_tx_link_put(link); return rc; } diff --git a/net/smc/smc_wr.h b/net/smc/smc_wr.h index 423b8709f1c9..2bc626f230a5 100644 --- a/net/smc/smc_wr.h +++ b/net/smc/smc_wr.h @@ -60,6 +60,20 @@ static inline void smc_wr_tx_set_wr_id(atomic_long_t *wr_tx_id, long val) atomic_long_set(wr_tx_id, val); } +static inline bool smc_wr_tx_link_hold(struct smc_link *link) +{ + if (!smc_link_usable(link)) + return false; + atomic_inc(&link->wr_tx_refcnt); + return true; +} + +static inline void smc_wr_tx_link_put(struct smc_link *link) +{ + if (atomic_dec_and_test(&link->wr_tx_refcnt)) + wake_up_all(&link->wr_tx_wait); +} + static inline void smc_wr_wakeup_tx_wait(struct smc_link *lnk) { wake_up_all(&lnk->wr_tx_wait);

[net-next,v2,01/11] net/smc: improved fix wait on already cleared link

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