From 3b7952109361c684caf0c50474da8662ecc81019 Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 13 Nov 2008 19:45:32 +0000 Subject: [CIFS] Fix cifs reconnection flags In preparation for Jeff's big umount/mount fixes to remove the possibility of various races in cifs mount and linked list handling of sessions, sockets and tree connections, this patch cleans up some repetitive code in cifs_mount, and addresses a problem with ses->status and tcon->tidStatus in which we were overloading the "need_reconnect" state with other status in that field. So the "need_reconnect" flag has been broken out from those two state fields (need reconnect was not mutually exclusive from some of the other possible tid and ses states). In addition, a few exit cases in cifs_mount were cleaned up, and a problem with a tcon flag (for lease support) was not being set consistently for the 2nd mount of the same share CC: Jeff Layton CC: Shirish Pargaonkar Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/cifs/cifsglob.h') diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 1cb1189..dc0aa14 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -122,6 +122,8 @@ struct cifs_cred { */ struct TCP_Server_Info { + struct list_head tcp_ses_list; + struct list_head smb_ses_list; /* 15 character server name + 0x20 16th byte indicating type = srv */ char server_RFC1001_name[SERVER_NAME_LEN_WITH_NULL]; char unicode_server_Name[SERVER_NAME_LEN_WITH_NULL * 2]; @@ -195,6 +197,7 @@ struct cifsUidInfo { */ struct cifsSesInfo { struct list_head cifsSessionList; + struct list_head tcon_list; struct semaphore sesSem; #if 0 struct cifsUidInfo *uidInfo; /* pointer to user info */ @@ -216,6 +219,7 @@ struct cifsSesInfo { char userName[MAX_USERNAME_SIZE + 1]; char *domainName; char *password; + bool need_reconnect:1; /* connection reset, uid now invalid */ }; /* no more than one of the following three session flags may be set */ #define CIFS_SES_NT4 1 @@ -288,6 +292,7 @@ struct cifsTconInfo { bool unix_ext:1; /* if false disable Linux extensions to CIFS protocol for this mount even if server would support */ bool local_lease:1; /* check leases (only) on local system not remote */ + bool need_reconnect:1; /* connection reset, tid now invalid */ /* BB add field for back pointer to sb struct(s)? */ }; -- cgit v1.1 From fb396016647ae9de5b3bd8c4ee4f7b9cc7148bd5 Mon Sep 17 00:00:00 2001 From: Steve French Date: Thu, 13 Nov 2008 20:04:07 +0000 Subject: [CIFS] remove unused list, add new cifs sock list to prepare for mount/umount fix Also adds two lines missing from the previous patch (for the need reconnect flag in the /proc/fs/cifs/DebugData handling) The new global_cifs_sock_list is added, and initialized in init_cifs but not used yet. Jeff Layton will be adding code in to use that and to remove the GlobalTcon and GlobalSMBSession lists. CC: Jeff Layton CC: Shirish Pargaonkar Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 23 ++++++++--------------- 1 file changed, 8 insertions(+), 15 deletions(-) (limited to 'fs/cifs/cifsglob.h') diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index dc0aa14..d6357dc 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -592,22 +592,15 @@ require use of the stronger protocol */ #define GLOBAL_EXTERN extern #endif -/* - * The list of servers that did not respond with NT LM 0.12. - * This list helps improve performance and eliminate the messages indicating - * that we had a communications error talking to the server in this list. - */ -/* Feature not supported */ -/* GLOBAL_EXTERN struct servers_not_supported *NotSuppList; */ - -/* - * The following is a hash table of all the users we know about. - */ -GLOBAL_EXTERN struct smbUidInfo *GlobalUidList[UID_HASH]; -/* GLOBAL_EXTERN struct list_head GlobalServerList; BB not implemented yet */ -GLOBAL_EXTERN struct list_head GlobalSMBSessionList; -GLOBAL_EXTERN struct list_head GlobalTreeConnectionList; +/* the list of TCP_Server_Info structures, ie each of the sockets + * connecting our client to a distinct server (ip address), is + * chained together by global_cifs_sock_list. The list of all our SMB + * sessions (and from that the tree connections) can be found + * by iterating over global_cifs_sock_list */ +GLOBAL_EXTERN struct list_head global_cifs_sock_list; +GLOBAL_EXTERN struct list_head GlobalSMBSessionList; /* BB to be removed by jl*/ +GLOBAL_EXTERN struct list_head GlobalTreeConnectionList; /* BB to be removed */ GLOBAL_EXTERN rwlock_t GlobalSMBSeslock; /* protects list inserts on 3 above */ GLOBAL_EXTERN struct list_head GlobalOplock_Q; -- cgit v1.1 From 3ec332ef7a38c2327e18d087d4120a8e3bd3dc6e Mon Sep 17 00:00:00 2001 From: Steve French Date: Fri, 14 Nov 2008 03:35:10 +0000 Subject: [CIFS] clean up server protocol handling We're currently declaring both a sockaddr_in and sockaddr6_in on the stack, but we really only need storage for one of them. Declare a sockaddr struct and cast it to the proper type. Also, eliminate the protocolType field in the TCP_Server_Info struct. It's redundant since we have a sa_family field in the sockaddr anyway. We may need to revisit this if SCTP is ever implemented, but for now this will simplify the code. CIFS over IPv6 also has a number of problems currently. This fixes all of them that I found. Eventually, it would be nice to move more of the code to be protocol independent, but this is a start. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'fs/cifs/cifsglob.h') diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index d6357dc..13dc484 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -85,8 +85,7 @@ enum securityEnum { }; enum protocolEnum { - IPV4 = 0, - IPV6, + TCP = 0, SCTP /* Netbios frames protocol not supported at this time */ }; -- cgit v1.1 From e7ddee9037e7dd43de1ad08b51727e552aedd836 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 14 Nov 2008 13:44:38 -0500 Subject: cifs: disable sharing session and tcon and add new TCP sharing code The code that allows these structs to be shared is extremely racy. Disable the sharing of SMB and tcon structs for now until we can come up with a way to do this that's race free. We want to continue to share TCP sessions, however since they are required for multiuser mounts. For that, implement a new (hopefully race-free) scheme. Add a new global list of TCP sessions, and take care to get a reference to it whenever we're dealing with one. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'fs/cifs/cifsglob.h') diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 13dc484..313f7bf 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -123,6 +123,7 @@ struct cifs_cred { struct TCP_Server_Info { struct list_head tcp_ses_list; struct list_head smb_ses_list; + int srv_count; /* reference counter */ /* 15 character server name + 0x20 16th byte indicating type = srv */ char server_RFC1001_name[SERVER_NAME_LEN_WITH_NULL]; char unicode_server_Name[SERVER_NAME_LEN_WITH_NULL * 2]; @@ -144,7 +145,6 @@ struct TCP_Server_Info { bool svlocal:1; /* local server or remote */ bool noblocksnd; /* use blocking sendmsg */ bool noautotune; /* do not autotune send buf sizes */ - atomic_t socketUseCount; /* number of open cifs sessions on socket */ atomic_t inFlight; /* number of requests on the wire to server */ #ifdef CONFIG_CIFS_STATS2 atomic_t inSend; /* requests trying to send */ @@ -591,13 +591,18 @@ require use of the stronger protocol */ #define GLOBAL_EXTERN extern #endif - -/* the list of TCP_Server_Info structures, ie each of the sockets +/* + * the list of TCP_Server_Info structures, ie each of the sockets * connecting our client to a distinct server (ip address), is - * chained together by global_cifs_sock_list. The list of all our SMB + * chained together by cifs_tcp_ses_list. The list of all our SMB * sessions (and from that the tree connections) can be found - * by iterating over global_cifs_sock_list */ -GLOBAL_EXTERN struct list_head global_cifs_sock_list; + * by iterating over cifs_tcp_ses_list + */ +GLOBAL_EXTERN struct list_head cifs_tcp_ses_list; + +/* protects cifs_tcp_ses_list and srv_count for each tcp session */ +GLOBAL_EXTERN rwlock_t cifs_tcp_ses_lock; + GLOBAL_EXTERN struct list_head GlobalSMBSessionList; /* BB to be removed by jl*/ GLOBAL_EXTERN struct list_head GlobalTreeConnectionList; /* BB to be removed */ GLOBAL_EXTERN rwlock_t GlobalSMBSeslock; /* protects list inserts on 3 above */ -- cgit v1.1 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/cifsglob.h | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'fs/cifs/cifsglob.h') diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 313f7bf..631a99f 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -195,14 +195,14 @@ struct cifsUidInfo { * Session structure. One of these for each uid session with a particular host */ struct cifsSesInfo { - struct list_head cifsSessionList; + struct list_head smb_ses_list; struct list_head tcon_list; struct semaphore sesSem; #if 0 struct cifsUidInfo *uidInfo; /* pointer to user info */ #endif struct TCP_Server_Info *server; /* pointer to server info */ - atomic_t inUse; /* # of mounts (tree connections) on this ses */ + int ses_count; /* reference counter */ enum statusEnum status; unsigned overrideSecFlg; /* if non-zero override global sec flags */ __u16 ipc_tid; /* special tid for connection to IPC share */ @@ -602,8 +602,6 @@ GLOBAL_EXTERN struct list_head cifs_tcp_ses_list; /* protects cifs_tcp_ses_list and srv_count for each tcp session */ GLOBAL_EXTERN rwlock_t cifs_tcp_ses_lock; - -GLOBAL_EXTERN struct list_head GlobalSMBSessionList; /* BB to be removed by jl*/ GLOBAL_EXTERN struct list_head GlobalTreeConnectionList; /* BB to be removed */ GLOBAL_EXTERN rwlock_t GlobalSMBSeslock; /* protects list inserts on 3 above */ -- cgit v1.1 From f1987b44f642e96176adc88b7ce23a1d74806f89 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Sat, 15 Nov 2008 11:12:47 -0500 Subject: cifs: reinstate sharing of tree connections Use a similar approach to the SMB session sharing. Add a list of tcons attached to each SMB session. Move the refcount to non-atomic. Protect all of the above with the cifs_tcp_ses_lock. Add functions to properly find and put references to the tcons. Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) (limited to 'fs/cifs/cifsglob.h') diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 631a99f..f1ae1f5 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -233,16 +233,15 @@ struct cifsSesInfo { * session */ struct cifsTconInfo { - struct list_head cifsConnectionList; + struct list_head tcon_list; + int tc_count; struct list_head openFileList; - struct semaphore tconSem; struct cifsSesInfo *ses; /* pointer to session associated with */ char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource in ASCII */ char *nativeFileSystem; __u16 tid; /* The 2 byte tree id */ __u16 Flags; /* optional support bits */ enum statusEnum tidStatus; - atomic_t useCount; /* how many explicit/implicit mounts to share */ #ifdef CONFIG_CIFS_STATS atomic_t num_smbs_sent; atomic_t num_writes; @@ -600,9 +599,13 @@ require use of the stronger protocol */ */ GLOBAL_EXTERN struct list_head cifs_tcp_ses_list; -/* protects cifs_tcp_ses_list and srv_count for each tcp session */ +/* + * This lock protects the cifs_tcp_ses_list, the list of smb sessions per + * tcp session, and the list of tcon's per smb session. It also protects + * the reference counters for the server, smb session, and tcon. Finally, + * changes to the tcon->tidStatus should be done while holding this lock. + */ GLOBAL_EXTERN rwlock_t cifs_tcp_ses_lock; -GLOBAL_EXTERN struct list_head GlobalTreeConnectionList; /* BB to be removed */ GLOBAL_EXTERN rwlock_t GlobalSMBSeslock; /* protects list inserts on 3 above */ GLOBAL_EXTERN struct list_head GlobalOplock_Q; -- cgit v1.1