cifs: add multichannel mount options and data structs

adds:
- [no]multichannel to enable/disable multichannel
- max_channels=N to control how many channels to create

these options are then stored in the volume struct.

- store channels and max_channels in cifs_ses

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 57453226469d..ac3710415f80 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -591,6 +591,10 @@ struct smb_vol {
 	bool resilient:1; /* noresilient not required since not fored for CA */
 	bool domainauto:1;
 	bool rdma:1;
+	bool multichannel:1;
+	bool use_client_guid:1;
+	/* reuse existing guid for multichannel */
+	u8 client_guid[SMB2_CLIENT_GUID_SIZE];
 	unsigned int bsize;
 	unsigned int rsize;
 	unsigned int wsize;
@@ -607,6 +611,7 @@ struct smb_vol {
 	__u64 snapshot_time; /* needed for timewarp tokens */
 	__u32 handle_timeout; /* persistent and durable handle timeout in ms */
 	unsigned int max_credits; /* smb3 max_credits 10 < credits < 60000 */
+	unsigned int max_channels;
 	__u16 compression; /* compression algorithm 0xFFFF default 0=disabled */
 	bool rootfs:1; /* if it's a SMB root file system */
 };
@@ -953,6 +958,11 @@ struct cifs_server_iface {
 	struct sockaddr_storage sockaddr;
 };
 
+struct cifs_chan {
+	struct TCP_Server_Info *server;
+	__u8 signkey[SMB3_SIGN_KEY_SIZE];
+};
+
 /*
  * Session structure.  One of these for each uid session with a particular host
  */
@@ -1002,6 +1012,12 @@ struct cifs_ses {
 	struct cifs_server_iface *iface_list;
 	size_t iface_count;
 	unsigned long iface_last_update; /* jiffies */
+
+#define CIFS_MAX_CHANNELS 16
+	struct cifs_chan chans[CIFS_MAX_CHANNELS];
+	size_t chan_count;
+	size_t chan_max;
+	atomic_t chan_seq; /* round robin state */
 };
 
 static inline bool