From 14fbf50d695207754daeb96270b3027a3821121f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 14 Nov 2008 13:53:46 -0500 Subject: cifs: reinstate sharing of SMB sessions sans races We do this by abandoning the global list of SMB sessions and instead moving to a per-server list. This entails adding a new list head to the TCP_Server_Info struct. The refcounting for the cifsSesInfo is moved to a non-atomic variable. We have to protect it by a lock anyway, so there's no benefit to making it an atomic. The list and refcount are protected by the global cifs_tcp_ses_lock. The patch also adds a new routines to find and put SMB sessions and that properly take and put references under the lock. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifssmb.c | 22 +++++++--------------- 1 file changed, 7 insertions(+), 15 deletions(-) (limited to 'fs/cifs/cifssmb.c') diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index cd9e9a145e4d..9c95617baa4d 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -799,20 +799,16 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses) int rc = 0; cFYI(1, ("In SMBLogoff for session disconnect")); - if (ses) - down(&ses->sesSem); - else - return -EIO; - - atomic_dec(&ses->inUse); - if (atomic_read(&ses->inUse) > 0) { - up(&ses->sesSem); - return -EBUSY; - } - if (ses->server == NULL) + /* + * BB: do we need to check validity of ses and server? They should + * always be valid since we have an active reference. If not, that + * should probably be a BUG() + */ + if (!ses || !ses->server) return -EIO; + down(&ses->sesSem); if (ses->need_reconnect) goto session_already_dead; /* no need to send SMBlogoff if uid already closed due to reconnect */ @@ -833,10 +829,6 @@ CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses) pSMB->AndXCommand = 0xFF; rc = SendReceiveNoRsp(xid, ses, (struct smb_hdr *) pSMB, 0); session_already_dead: - if (ses->server) { - cifs_put_tcp_session(ses->server); - rc = 0; - } up(&ses->sesSem); /* if session dead then we do not need to do ulogoff, -- cgit v1.2.3