From 2d86dbc97094ea4cfc2204fdefd7d07685496189 Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Mon, 6 Feb 2012 15:59:18 +0400 Subject: 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 Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'fs/cifs/cifsglob.h') diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index fb78bc903887..d55de9684df9 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -250,8 +250,9 @@ 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]; @@ -314,12 +315,14 @@ in_flight(struct TCP_Server_Info *server) return num; } -static inline void -dec_in_flight(struct TCP_Server_Info *server) +static inline bool +has_credits(struct TCP_Server_Info *server) { + int num; spin_lock(&server->req_lock); - server->in_flight--; + num = server->credits; spin_unlock(&server->req_lock); + return num > 0; } /* -- cgit v1.2.3