diff options
| author | Pavel Shilovsky <piastry@etersoft.ru> | 2012-02-06 15:59:18 +0400 |
|---|---|---|
| committer | Steve French <sfrench@us.ibm.com> | 2012-03-21 20:35:03 +0400 |
| commit | 2d86dbc97094ea4cfc2204fdefd7d07685496189 (patch) | |
| tree | 9aee614e155fd837c78ded2cd083dead1a9d4a3f /fs/cifs/connect.c | |
| parent | fc40f9cf828908e91d9af820e9300a9d42fbbd72 (diff) | |
| download | linux-2d86dbc97094ea4cfc2204fdefd7d07685496189.tar.xz | |
CIFS: Introduce credit-based flow control
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.
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs/cifs/connect.c')
| -rw-r--r-- | fs/cifs/connect.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index ed91abcce8a9..1d489010615b 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -642,14 +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. */ + /* check if we have blocked requests that need to free */ spin_lock(&server->req_lock); - if (server->in_flight >= server->maxReq) - server->in_flight = server->maxReq - 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 @@ -1906,7 +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->maxReq = 1; /* enough to send negotiate request */ + tcp_ses->credits = 1; init_waitqueue_head(&tcp_ses->response_q); init_waitqueue_head(&tcp_ses->request_q); INIT_LIST_HEAD(&tcp_ses->pending_mid_q); @@ -3757,9 +3753,11 @@ int cifs_negotiate_protocol(unsigned int xid, struct cifs_ses *ses) if (server->maxBuf != 0) return 0; + cifs_set_credits(server, 1); rc = CIFSSMBNegotiate(xid, ses); if (rc == -EAGAIN) { /* retry only once on 1st time connection */ + cifs_set_credits(server, 1); rc = CIFSSMBNegotiate(xid, ses); if (rc == -EAGAIN) rc = -EHOSTDOWN; |