and send no more than credits value requests at once. For SMB/CIFS it's trivial: increment this value by receiving any message and decrement by sending one.
Signed-off-by: Pavel Shilovsky <[email protected]> --- fs/cifs/cifsglob.h | 24 ++++++++++++++++++++++-- fs/cifs/cifssmb.c | 6 +++--- fs/cifs/connect.c | 17 ++++++----------- fs/cifs/transport.c | 30 ++++++++++++++++-------------- 4 files changed, 47 insertions(+), 30 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 44cfc9a..35d3df4 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -255,8 +255,9 @@ struct TCP_Server_Info { bool noblocksnd; /* use blocking sendmsg */ bool noautotune; /* do not autotune send buf sizes */ bool tcp_nodelay; + int credits; /* send no more requests at once */ unsigned int in_flight; /* number of requests on the wire to server */ - spinlock_t req_lock; /* protect the value above */ + spinlock_t req_lock; /* protect the two values above */ struct mutex srv_mutex; struct task_struct *tsk; char server_GUID[16]; @@ -318,14 +319,33 @@ in_flight(struct TCP_Server_Info *server) return num; } +static inline int +get_credits(struct TCP_Server_Info *server) +{ + int num; + spin_lock(&server->req_lock); + num = server->credits; + spin_unlock(&server->req_lock); + return num; +} + static inline void -dec_in_flight(struct TCP_Server_Info *server) +add_credits(struct TCP_Server_Info *server, const unsigned int add) { spin_lock(&server->req_lock); + server->credits += add; server->in_flight--; spin_unlock(&server->req_lock); } +static inline void +set_credits(struct TCP_Server_Info *server, const int val) +{ + spin_lock(&server->req_lock); + server->credits = val; + spin_unlock(&server->req_lock); +} + /* * Macros to allow the TCP_Server_Info->net field and related code to drop out * when CONFIG_NET_NS isn't set. diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 0b50551..c255c25 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -716,7 +716,7 @@ cifs_echo_callback(struct mid_q_entry *mid) struct TCP_Server_Info *server = mid->callback_data; DeleteMidQEntry(mid); - dec_in_flight(server); + add_credits(server, 1); wake_up(&server->request_q); } @@ -1669,7 +1669,7 @@ cifs_readv_callback(struct mid_q_entry *mid) queue_work(system_nrt_wq, &rdata->work); DeleteMidQEntry(mid); - dec_in_flight(server); + add_credits(server, 1); wake_up(&server->request_q); } @@ -2110,7 +2110,7 @@ cifs_writev_callback(struct mid_q_entry *mid) queue_work(system_nrt_wq, &wdata->work); DeleteMidQEntry(mid); - dec_in_flight(tcon->ses->server); + add_credits(tcon->ses->server, 1); wake_up(&tcon->ses->server->request_q); } diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 12286d0..673813f 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -642,18 +642,10 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server) spin_unlock(&GlobalMid_Lock); wake_up_all(&server->response_q); - /* - * Check if we have blocked requests that need to free. Note that - * cifs_max_pending is normally 50, but can be set at module install - * time to as little as two. - */ + /* check if we have blocked requests that need to free */ spin_lock(&server->req_lock); - if (server->in_flight >= cifs_max_pending) - server->in_flight = cifs_max_pending - 1; - /* - * We do not want to set the max_pending too low or we could end up - * with the counter going negative. - */ + if (server->credits <= 0) + server->credits = 1; spin_unlock(&server->req_lock); /* * Although there should not be any requests blocked on this queue it @@ -1910,6 +1902,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info) tcp_ses->noautotune = volume_info->noautotune; tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay; tcp_ses->in_flight = 0; + tcp_ses->credits = cifs_max_pending; init_waitqueue_head(&tcp_ses->response_q); init_waitqueue_head(&tcp_ses->request_q); INIT_LIST_HEAD(&tcp_ses->pending_mid_q); @@ -3759,9 +3752,11 @@ int cifs_negotiate_protocol(unsigned int xid, struct cifs_ses *ses) if (server->maxBuf != 0) return 0; + set_credits(server, cifs_max_pending); rc = CIFSSMBNegotiate(xid, ses); if (rc == -EAGAIN) { /* retry only once on 1st time connection */ + set_credits(server, cifs_max_pending); rc = CIFSSMBNegotiate(xid, ses); if (rc == -EAGAIN) rc = -EHOSTDOWN; diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index fc1904f..44ac0aa 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -262,16 +262,16 @@ wait_for_free_request(struct TCP_Server_Info *server, const int long_op) if (long_op == CIFS_ASYNC_OP) { /* oplock breaks must not be held up */ server->in_flight++; + server->credits--; spin_unlock(&server->req_lock); return 0; } while (1) { - if (server->in_flight >= cifs_max_pending) { + if (server->credits <= 0) { spin_unlock(&server->req_lock); cifs_num_waiters_inc(server); - wait_event(server->request_q, - in_flight(server) < cifs_max_pending); + wait_event(server->request_q, get_credits(server) > 0); cifs_num_waiters_dec(server); spin_lock(&server->req_lock); } else { @@ -284,8 +284,10 @@ wait_for_free_request(struct TCP_Server_Info *server, const int long_op) as they are allowed to block on server */ /* update # of requests on the wire to server */ - if (long_op != CIFS_BLOCKING_OP) + if (long_op != CIFS_BLOCKING_OP) { + server->credits--; server->in_flight++; + } spin_unlock(&server->req_lock); break; } @@ -360,7 +362,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov, mid = AllocMidQEntry(hdr, server); if (mid == NULL) { mutex_unlock(&server->srv_mutex); - dec_in_flight(server); + add_credits(server, 1); wake_up(&server->request_q); return -ENOMEM; } @@ -393,7 +395,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov, return rc; out_err: delete_mid(mid); - dec_in_flight(server); + add_credits(server, 1); wake_up(&server->request_q); return rc; } @@ -565,7 +567,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses, mutex_unlock(&ses->server->srv_mutex); cifs_small_buf_release(in_buf); /* Update # of requests on wire to server */ - dec_in_flight(ses->server); + add_credits(ses->server, 1); wake_up(&ses->server->request_q); return rc; } @@ -602,7 +604,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses, midQ->callback = DeleteMidQEntry; spin_unlock(&GlobalMid_Lock); cifs_small_buf_release(in_buf); - dec_in_flight(ses->server); + add_credits(ses->server, 1); wake_up(&ses->server->request_q); return rc; } @@ -613,7 +615,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses, rc = cifs_sync_mid_result(midQ, ses->server); if (rc != 0) { - dec_in_flight(ses->server); + add_credits(ses->server, 1); wake_up(&ses->server->request_q); return rc; } @@ -638,7 +640,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses, midQ->resp_buf = NULL; out: delete_mid(midQ); - dec_in_flight(ses->server); + add_credits(ses->server, 1); wake_up(&ses->server->request_q); return rc; @@ -689,7 +691,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, if (rc) { mutex_unlock(&ses->server->srv_mutex); /* Update # of requests on wire to server */ - dec_in_flight(ses->server); + add_credits(ses->server, 1); wake_up(&ses->server->request_q); return rc; } @@ -722,7 +724,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, /* no longer considered to be "in-flight" */ midQ->callback = DeleteMidQEntry; spin_unlock(&GlobalMid_Lock); - dec_in_flight(ses->server); + add_credits(ses->server, 1); wake_up(&ses->server->request_q); return rc; } @@ -731,7 +733,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, rc = cifs_sync_mid_result(midQ, ses->server); if (rc != 0) { - dec_in_flight(ses->server); + add_credits(ses->server, 1); wake_up(&ses->server->request_q); return rc; } @@ -748,7 +750,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses, rc = cifs_check_receive(midQ, ses->server, 0); out: delete_mid(midQ); - dec_in_flight(ses->server); + add_credits(ses->server, 1); wake_up(&ses->server->request_q); return rc; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
