diff options
| author | Jeff Layton <jlayton@redhat.com> | 2013-09-16 17:23:45 +0200 |
|---|---|---|
| committer | Steve French <smfrench@gmail.com> | 2013-09-18 17:23:44 +0200 |
| commit | 9ae6cf606a33b0a762798df0fb742848bcc685b5 (patch) | |
| tree | 7e6c8e2b5877d89869a997baa7d158943ab42d3e /fs/cifs/cifsglob.h | |
| parent | CIFS: FS-Cache: Uncache unread pages in cifs_readpages() before freeing them (diff) | |
| download | linux-9ae6cf606a33b0a762798df0fb742848bcc685b5.tar.xz linux-9ae6cf606a33b0a762798df0fb742848bcc685b5.zip | |
cifs: stop trying to use virtual circuits
Currently, we try to ensure that we use vcnum of 0 on the first
established session on a connection and then try to use a different
vcnum on each session after that.
This is a little odd, since there's no real reason to use a different
vcnum for each SMB session. I can only assume there was some confusion
between SMB sessions and VCs. That's somewhat understandable since they
both get created during SESSION_SETUP, but the documentation indicates
that they are really orthogonal. The comment on max_vcs in particular
looks quite misguided. An SMB session is already uniquely identified
by the SMB UID value -- there's no need to again uniquely ID with a
VC.
Furthermore, a vcnum of 0 is a cue to the server that it should release
any resources that were previously held by the client. This sounds like
a good thing, until you consider that:
a) it totally ignores the fact that other programs on the box (e.g.
smbclient) might have connections established to the server. Using a
vcnum of 0 causes them to get kicked off.
b) it causes problems with NAT. If several clients are connected to the
same server via the same NAT'ed address, whenever one connects to the
server it kicks off all the others, which then reconnect and kick off
the first one...ad nauseum.
I don't see any reason to ignore the advice in "Implementing CIFS" which
has a comprehensive treatment of virtual circuits. In there, it states
"...and contrary to the specs the client should always use a VcNumber of
one, never zero."
Have the client just use a hardcoded vcnum of 1, and stop abusing the
special behavior of vcnum 0.
Reported-by: Sauron99@gmx.de <sauron99@gmx.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>
Diffstat (limited to 'fs/cifs/cifsglob.h')
| -rw-r--r-- | fs/cifs/cifsglob.h | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index cfa14c80ef3b..9c72be6fb0df 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -547,9 +547,6 @@ struct TCP_Server_Info { unsigned int max_rw; /* maxRw specifies the maximum */ /* message size the server can send or receive for */ /* SMB_COM_WRITE_RAW or SMB_COM_READ_RAW. */ - unsigned int max_vcs; /* maximum number of smb sessions, at least - those that can be specified uniquely with - vcnumbers */ unsigned int capabilities; /* selective disabling of caps by smb sess */ int timeAdj; /* Adjust for difference in server time zone in sec */ __u64 CurrentMid; /* multiplex id - rotating counter */ @@ -715,7 +712,6 @@ struct cifs_ses { enum statusEnum status; unsigned overrideSecFlg; /* if non-zero override global sec flags */ __u16 ipc_tid; /* special tid for connection to IPC share */ - __u16 vcnum; char *serverOS; /* name of operating system underlying server */ char *serverNOS; /* name of network operating system of server */ char *serverDomain; /* security realm of server */ |