Merge tag '5.17-rc-part1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs updates from Steve French:

 - multichannel patches mostly related to improving reconnect behavior

 - minor cleanup patches

* tag '5.17-rc-part1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: fix FILE_BOTH_DIRECTORY_INFO definition
  cifs: move superblock magic defitions to magic.h
  cifs: Fix smb311_update_preauth_hash() kernel-doc comment
  cifs: avoid race during socket reconnect between send and recv
  cifs: maintain a state machine for tcp/smb/tcon sessions
  cifs: fix hang on cifs_get_next_mid()
  cifs: take cifs_tcp_ses_lock for status checks
  cifs: reconnect only the connection and not smb session where possible
  cifs: add WARN_ON for when chan_count goes below minimum
  cifs: adjust DebugData to use chans_need_reconnect for conn status
  cifs: use the chans_need_reconnect bitmap for reconnect status
  cifs: track individual channel status using chans_need_reconnect
  cifs: remove redundant assignment to pointer p

fs/cifs/cifs_debug.c

@@ -416,11 +416,17 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
 				   from_kuid(&init_user_ns, ses->cred_uid));
 
 			spin_lock(&ses->chan_lock);
+			if (CIFS_CHAN_NEEDS_RECONNECT(ses, 0))
+				seq_puts(m, "\tPrimary channel: DISCONNECTED ");
+
 			if (ses->chan_count > 1) {
 				seq_printf(m, "\n\n\tExtra Channels: %zu ",
 					   ses->chan_count-1);
-				for (j = 1; j < ses->chan_count; j++)
+				for (j = 1; j < ses->chan_count; j++) {
 					cifs_dump_channel(m, j, &ses->chans[j]);
+					if (CIFS_CHAN_NEEDS_RECONNECT(ses, j))
+						seq_puts(m, "\tDISCONNECTED ");
+				}
 			}
 			spin_unlock(&ses->chan_lock);
 

fs/cifs/cifs_spnego.c

@@ -84,9 +84,9 @@ struct key_type cifs_spnego_key_type = {
 
 /* get a key struct with a SPNEGO security blob, suitable for session setup */
 struct key *
-cifs_get_spnego_key(struct cifs_ses *sesInfo)
+cifs_get_spnego_key(struct cifs_ses *sesInfo,
+		    struct TCP_Server_Info *server)
 {
-	struct TCP_Server_Info *server = cifs_ses_server(sesInfo);
 	struct sockaddr_in *sa = (struct sockaddr_in *) &server->dstaddr;
 	struct sockaddr_in6 *sa6 = (struct sockaddr_in6 *) &server->dstaddr;
 	char *description, *dp;

fs/cifs/cifs_spnego.h

@@ -29,7 +29,8 @@ struct cifs_spnego_msg {
 
 #ifdef __KERNEL__
 extern struct key_type cifs_spnego_key_type;
-extern struct key *cifs_get_spnego_key(struct cifs_ses *sesInfo);
+extern struct key *cifs_get_spnego_key(struct cifs_ses *sesInfo,
+				       struct TCP_Server_Info *server);
 #endif /* KERNEL */
 
 #endif /* _CIFS_SPNEGO_H */

fs/cifs/cifs_swn.c

@@ -498,10 +498,10 @@ static int cifs_swn_reconnect(struct cifs_tcon *tcon, struct sockaddr_storage *a
 		goto unlock;
 	}
 
-	spin_lock(&GlobalMid_Lock);
+	spin_lock(&cifs_tcp_ses_lock);
 	if (tcon->ses->server->tcpStatus != CifsExiting)
 		tcon->ses->server->tcpStatus = CifsNeedReconnect;
-	spin_unlock(&GlobalMid_Lock);
+	spin_unlock(&cifs_tcp_ses_lock);
 
 unlock:
 	mutex_unlock(&tcon->ses->server->srv_mutex);

fs/cifs/cifsencrypt.c

@@ -141,9 +141,13 @@ int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 	if ((cifs_pdu == NULL) || (server == NULL))
 		return -EINVAL;
 
+	spin_lock(&cifs_tcp_ses_lock);
 	if (!(cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) ||
-	    server->tcpStatus == CifsNeedNegotiate)
+	    server->tcpStatus == CifsNeedNegotiate) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return rc;
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	if (!server->session_estab) {
 		memcpy(cifs_pdu->Signature.SecuritySignature, "BSRSPYL", 8);

fs/cifs/cifsfs.c

@@ -26,6 +26,7 @@
 #include <linux/random.h>
 #include <linux/uuid.h>
 #include <linux/xattr.h>
+#include <uapi/linux/magic.h>
 #include <net/ipv6.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
@@ -202,7 +203,7 @@ cifs_read_super(struct super_block *sb)
 		sb->s_time_max = ts.tv_sec;
 	}
 
-	sb->s_magic = CIFS_MAGIC_NUMBER;
+	sb->s_magic = CIFS_SUPER_MAGIC;
 	sb->s_op = &cifs_super_ops;
 	sb->s_xattr = cifs_xattr_handlers;
 	rc = super_setup_bdi(sb);
@@ -773,7 +774,7 @@ cifs_get_root(struct smb3_fs_context *ctx, struct super_block *sb)
 
 	sep = CIFS_DIR_SEP(cifs_sb);
 	dentry = dget(sb->s_root);
-	p = s = full_path;
+	s = full_path;
 
 	do {
 		struct inode *dir = d_inode(dentry);

fs/cifs/cifsglob.h

@@ -24,8 +24,6 @@
 #include "../smbfs_common/smb2pdu.h"
 #include "smb2pdu.h"
 
-#define CIFS_MAGIC_NUMBER 0xFF534D42      /* the first four bytes of SMB PDUs */
-
 #define SMB_PATH_MAX 260
 #define CIFS_PORT 445
 #define RFC1001_PORT 139
@@ -113,7 +111,13 @@ enum statusEnum {
 	CifsGood,
 	CifsExiting,
 	CifsNeedReconnect,
-	CifsNeedNegotiate
+	CifsNeedNegotiate,
+	CifsInNegotiate,
+	CifsNeedSessSetup,
+	CifsInSessSetup,
+	CifsNeedTcon,
+	CifsInTcon,
+	CifsInFilesInvalidate
 };
 
 enum securityEnum {
@@ -263,13 +267,16 @@ struct smb_version_operations {
 	/* check if we need to negotiate */
 	bool (*need_neg)(struct TCP_Server_Info *);
 	/* negotiate to the server */
-	int (*negotiate)(const unsigned int, struct cifs_ses *);
+	int (*negotiate)(const unsigned int xid,
+			 struct cifs_ses *ses,
+			 struct TCP_Server_Info *server);
 	/* set negotiated write size */
 	unsigned int (*negotiate_wsize)(struct cifs_tcon *tcon, struct smb3_fs_context *ctx);
 	/* set negotiated read size */
 	unsigned int (*negotiate_rsize)(struct cifs_tcon *tcon, struct smb3_fs_context *ctx);
 	/* setup smb sessionn */
 	int (*sess_setup)(const unsigned int, struct cifs_ses *,
+			  struct TCP_Server_Info *server,
 			  const struct nls_table *);
 	/* close smb session */
 	int (*logoff)(const unsigned int, struct cifs_ses *);
@@ -414,7 +421,8 @@ struct smb_version_operations {
 	void (*set_lease_key)(struct inode *, struct cifs_fid *);
 	/* generate new lease key */
 	void (*new_lease_key)(struct cifs_fid *);
-	int (*generate_signingkey)(struct cifs_ses *);
+	int (*generate_signingkey)(struct cifs_ses *ses,
+				   struct TCP_Server_Info *server);
 	int (*calc_signature)(struct smb_rqst *, struct TCP_Server_Info *,
 				bool allocate_crypto);
 	int (*set_integrity)(const unsigned int, struct cifs_tcon *tcon,
@@ -582,7 +590,7 @@ struct TCP_Server_Info {
 	char server_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL];
 	struct smb_version_operations	*ops;
 	struct smb_version_values	*vals;
-	/* updates to tcpStatus protected by GlobalMid_Lock */
+	/* updates to tcpStatus protected by cifs_tcp_ses_lock */
 	enum statusEnum tcpStatus; /* what we think the status is */
 	char *hostname; /* hostname portion of UNC string */
 	struct socket *ssocket;
@@ -920,7 +928,7 @@ struct cifs_ses {
 	struct mutex session_mutex;
 	struct TCP_Server_Info *server;	/* pointer to server info */
 	int ses_count;		/* reference counter */
-	enum statusEnum status;  /* updates protected by GlobalMid_Lock */
+	enum statusEnum status;  /* updates protected by cifs_tcp_ses_lock */
 	unsigned overrideSecFlg;  /* if non-zero override global sec flags */
 	char *serverOS;		/* name of operating system underlying server */
 	char *serverNOS;	/* name of network operating system of server */
@@ -939,17 +947,13 @@ struct cifs_ses {
 	struct ntlmssp_auth *ntlmssp; /* ciphertext, flags, server challenge */
 	enum securityEnum sectype; /* what security flavor was specified? */
 	bool sign;		/* is signing required? */
-	bool need_reconnect:1; /* connection reset, uid now invalid */
 	bool domainAuto:1;
-	bool binding:1; /* are we binding the session? */
 	__u16 session_flags;
 	__u8 smb3signingkey[SMB3_SIGN_KEY_SIZE];
 	__u8 smb3encryptionkey[SMB3_ENC_DEC_KEY_SIZE];
 	__u8 smb3decryptionkey[SMB3_ENC_DEC_KEY_SIZE];
 	__u8 preauth_sha_hash[SMB2_PREAUTH_HASH_SIZE];
 
-	__u8 binding_preauth_sha_hash[SMB2_PREAUTH_HASH_SIZE];
-
 	/*
 	 * Network interfaces available on the server this session is
 	 * connected to.
@@ -969,45 +973,34 @@ struct cifs_ses {
 	spinlock_t chan_lock;
 	/* ========= begin: protected by chan_lock ======== */
 #define CIFS_MAX_CHANNELS 16
+#define CIFS_ALL_CHANNELS_SET(ses)	\
+	((1UL << (ses)->chan_count) - 1)
+#define CIFS_ALL_CHANS_NEED_RECONNECT(ses)	\
+	((ses)->chans_need_reconnect == CIFS_ALL_CHANNELS_SET(ses))
+#define CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses)	\
+	((ses)->chans_need_reconnect = CIFS_ALL_CHANNELS_SET(ses))
+#define CIFS_CHAN_NEEDS_RECONNECT(ses, index)	\
+	test_bit((index), &(ses)->chans_need_reconnect)
+
 	struct cifs_chan chans[CIFS_MAX_CHANNELS];
-	struct cifs_chan *binding_chan;
 	size_t chan_count;
 	size_t chan_max;
 	atomic_t chan_seq; /* round robin state */
+
+	/*
+	 * chans_need_reconnect is a bitmap indicating which of the channels
+	 * under this smb session needs to be reconnected.
+	 * If not multichannel session, only one bit will be used.
+	 *
+	 * We will ask for sess and tcon reconnection only if all the
+	 * channels are marked for needing reconnection. This will
+	 * enable the sessions on top to continue to live till any
+	 * of the channels below are active.
+	 */
+	unsigned long chans_need_reconnect;
 	/* ========= end: protected by chan_lock ======== */
 };
 
-/*
- * When binding a new channel, we need to access the channel which isn't fully
- * established yet.
- */
-
-static inline
-struct cifs_chan *cifs_ses_binding_channel(struct cifs_ses *ses)
-{
-	if (ses->binding)
-		return ses->binding_chan;
-	else
-		return NULL;
-}
-
-/*
- * Returns the server pointer of the session. When binding a new
- * channel this returns the last channel which isn't fully established
- * yet.
- *
- * This function should be use for negprot/sess.setup codepaths. For
- * the other requests see cifs_pick_channel().
- */
-static inline
-struct TCP_Server_Info *cifs_ses_server(struct cifs_ses *ses)
-{
-	if (ses->binding)
-		return ses->binding_chan->server;
-	else
-		return ses->server;
-}
-
 static inline bool
 cap_unix(struct cifs_ses *ses)
 {

fs/cifs/cifspdu.h

@@ -2560,7 +2560,7 @@ typedef struct {
 	__le32 EaSize; /* length of the xattrs */
 	__u8   ShortNameLength;
 	__u8   Reserved;
-	__u8   ShortName[12];
+	__u8   ShortName[24];
 	char FileName[1];
 } __attribute__((packed)) FILE_BOTH_DIRECTORY_INFO; /* level 0x104 FFrsp data */
 

fs/cifs/cifsproto.h

@@ -131,7 +131,8 @@ extern int SendReceiveBlockingLock(const unsigned int xid,
 			struct smb_hdr *in_buf ,
 			struct smb_hdr *out_buf,
 			int *bytes_returned);
-extern int cifs_reconnect(struct TCP_Server_Info *server);
+extern int cifs_reconnect(struct TCP_Server_Info *server,
+			  bool mark_smb_session);
 extern int checkSMB(char *buf, unsigned int len, struct TCP_Server_Info *srvr);
 extern bool is_valid_oplock_break(char *, struct TCP_Server_Info *);
 extern bool backup_cred(struct cifs_sb_info *);
@@ -164,6 +165,7 @@ extern int small_smb_init_no_tc(const int smb_cmd, const int wct,
 extern enum securityEnum select_sectype(struct TCP_Server_Info *server,
 				enum securityEnum requested);
 extern int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
+			  struct TCP_Server_Info *server,
 			  const struct nls_table *nls_cp);
 extern struct timespec64 cifs_NTtimeToUnix(__le64 utc_nanoseconds_since_1601);
 extern u64 cifs_UnixTimeToNT(struct timespec64);
@@ -293,11 +295,15 @@ extern int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon,
 			     const struct nls_table *nlsc);
 
 extern int cifs_negotiate_protocol(const unsigned int xid,
-				   struct cifs_ses *ses);
+				   struct cifs_ses *ses,
+				   struct TCP_Server_Info *server);
 extern int cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
+			      struct TCP_Server_Info *server,
 			      struct nls_table *nls_info);
 extern int cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required);
-extern int CIFSSMBNegotiate(const unsigned int xid, struct cifs_ses *ses);
+extern int CIFSSMBNegotiate(const unsigned int xid,
+			    struct cifs_ses *ses,
+			    struct TCP_Server_Info *server);
 
 extern int CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
 		    const char *tree, struct cifs_tcon *tcon,
@@ -504,8 +510,10 @@ extern int cifs_verify_signature(struct smb_rqst *rqst,
 extern int setup_ntlmv2_rsp(struct cifs_ses *, const struct nls_table *);
 extern void cifs_crypto_secmech_release(struct TCP_Server_Info *server);
 extern int calc_seckey(struct cifs_ses *);
-extern int generate_smb30signingkey(struct cifs_ses *);
-extern int generate_smb311signingkey(struct cifs_ses *);
+extern int generate_smb30signingkey(struct cifs_ses *ses,
+				    struct TCP_Server_Info *server);
+extern int generate_smb311signingkey(struct cifs_ses *ses,
+				     struct TCP_Server_Info *server);
 
 extern int CIFSSMBCopy(unsigned int xid,
 			struct cifs_tcon *source_tcon,
@@ -601,6 +609,19 @@ bool is_server_using_iface(struct TCP_Server_Info *server,
 bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface);
 void cifs_ses_mark_for_reconnect(struct cifs_ses *ses);
 
+unsigned int
+cifs_ses_get_chan_index(struct cifs_ses *ses,
+			struct TCP_Server_Info *server);
+void
+cifs_chan_set_need_reconnect(struct cifs_ses *ses,
+			     struct TCP_Server_Info *server);
+void
+cifs_chan_clear_need_reconnect(struct cifs_ses *ses,
+			       struct TCP_Server_Info *server);
+bool
+cifs_chan_needs_reconnect(struct cifs_ses *ses,
+			  struct TCP_Server_Info *server);
+
 void extract_unc_hostname(const char *unc, const char **h, size_t *len);
 int copy_path_name(char *dst, const char *src);
 int smb2_parse_query_directory(struct cifs_tcon *tcon, struct kvec *rsp_iov,

fs/cifs/cifssmb.c

@@ -73,6 +73,16 @@ cifs_mark_open_files_invalid(struct cifs_tcon *tcon)
 	struct list_head *tmp;
 	struct list_head *tmp1;
 
+	/* only send once per connect */
+	spin_lock(&cifs_tcp_ses_lock);
+	if (tcon->ses->status != CifsGood ||
+	    tcon->tidStatus != CifsNeedReconnect) {
+		spin_unlock(&cifs_tcp_ses_lock);
+		return;
+	}
+	tcon->tidStatus = CifsInFilesInvalidate;
+	spin_unlock(&cifs_tcp_ses_lock);
+
 	/* list all files open on tree connection and mark them invalid */
 	spin_lock(&tcon->open_file_lock);
 	list_for_each_safe(tmp, tmp1, &tcon->openFileList) {
@@ -89,6 +99,11 @@ cifs_mark_open_files_invalid(struct cifs_tcon *tcon)
 	memset(tcon->crfid.fid, 0, sizeof(struct cifs_fid));
 	mutex_unlock(&tcon->crfid.fid_mutex);
 
+	spin_lock(&cifs_tcp_ses_lock);
+	if (tcon->tidStatus == CifsInFilesInvalidate)
+		tcon->tidStatus = CifsNeedTcon;
+	spin_unlock(&cifs_tcp_ses_lock);
+
 	/*
 	 * BB Add call to invalidate_inodes(sb) for all superblocks mounted
 	 * to this tcon.
@@ -120,15 +135,18 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command)
 	 * only tree disconnect, open, and write, (and ulogoff which does not
 	 * have tcon) are allowed as we start force umount
 	 */
+	spin_lock(&cifs_tcp_ses_lock);
 	if (tcon->tidStatus == CifsExiting) {
 		if (smb_command != SMB_COM_WRITE_ANDX &&
 		    smb_command != SMB_COM_OPEN_ANDX &&
 		    smb_command != SMB_COM_TREE_DISCONNECT) {
+			spin_unlock(&cifs_tcp_ses_lock);
 			cifs_dbg(FYI, "can not send cmd %d while umounting\n",
 				 smb_command);
 			return -ENODEV;
 		}
 	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	retries = server->nr_targets;
 
@@ -148,8 +166,12 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command)
 		}
 
 		/* are we still trying to reconnect? */
-		if (server->tcpStatus != CifsNeedReconnect)
+		spin_lock(&cifs_tcp_ses_lock);
+		if (server->tcpStatus != CifsNeedReconnect) {
+			spin_unlock(&cifs_tcp_ses_lock);
 			break;
+		}
+		spin_unlock(&cifs_tcp_ses_lock);
 
 		if (retries && --retries)
 			continue;
@@ -166,31 +188,49 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command)
 		retries = server->nr_targets;
 	}
 
-	if (!ses->need_reconnect && !tcon->need_reconnect)
+	spin_lock(&ses->chan_lock);
+	if (!cifs_chan_needs_reconnect(ses, server) && !tcon->need_reconnect) {
+		spin_unlock(&ses->chan_lock);
 		return 0;
+	}
+	spin_unlock(&ses->chan_lock);
 
 	nls_codepage = load_nls_default();
 
-	/*
-	 * need to prevent multiple threads trying to simultaneously
-	 * reconnect the same SMB session
-	 */
-	mutex_lock(&ses->session_mutex);
-
 	/*
 	 * Recheck after acquire mutex. If another thread is negotiating
 	 * and the server never sends an answer the socket will be closed
 	 * and tcpStatus set to reconnect.
 	 */
+	spin_lock(&cifs_tcp_ses_lock);
 	if (server->tcpStatus == CifsNeedReconnect) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		rc = -EHOSTDOWN;
-		mutex_unlock(&ses->session_mutex);
 		goto out;
 	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
-	rc = cifs_negotiate_protocol(0, ses);
-	if (rc == 0 && ses->need_reconnect)
-		rc = cifs_setup_session(0, ses, nls_codepage);
+	/*
+	 * need to prevent multiple threads trying to simultaneously
+	 * reconnect the same SMB session
+	 */
+	spin_lock(&ses->chan_lock);
+	if (!cifs_chan_needs_reconnect(ses, server)) {
+		spin_unlock(&ses->chan_lock);
+
+		/* this means that we only need to tree connect */
+		if (tcon->need_reconnect)
+			goto skip_sess_setup;
+
+		rc = -EHOSTDOWN;
+		goto out;
+	}
+	spin_unlock(&ses->chan_lock);
+
+	mutex_lock(&ses->session_mutex);
+	rc = cifs_negotiate_protocol(0, ses, server);
+	if (!rc)
+		rc = cifs_setup_session(0, ses, server, nls_codepage);
 
 	/* do we need to reconnect tcon? */
 	if (rc || !tcon->need_reconnect) {
@@ -198,6 +238,7 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command)
 		goto out;
 	}
 
+skip_sess_setup:
 	cifs_mark_open_files_invalid(tcon);
 	rc = cifs_tree_connect(0, tcon, nls_codepage);
 	mutex_unlock(&ses->session_mutex);
@@ -337,8 +378,13 @@ static int
 smb_init_no_reconnect(int smb_command, int wct, struct cifs_tcon *tcon,
 			void **request_buf, void **response_buf)
 {
-	if (tcon->ses->need_reconnect || tcon->need_reconnect)
+	spin_lock(&tcon->ses->chan_lock);
+	if (cifs_chan_needs_reconnect(tcon->ses, tcon->ses->server) ||
+	    tcon->need_reconnect) {
+		spin_unlock(&tcon->ses->chan_lock);
 		return -EHOSTDOWN;
+	}
+	spin_unlock(&tcon->ses->chan_lock);
 
 	return __smb_init(smb_command, wct, tcon, request_buf, response_buf);
 }
@@ -476,14 +522,15 @@ should_set_ext_sec_flag(enum securityEnum sectype)
 }
 
 int
-CIFSSMBNegotiate(const unsigned int xid, struct cifs_ses *ses)
+CIFSSMBNegotiate(const unsigned int xid,
+		 struct cifs_ses *ses,
+		 struct TCP_Server_Info *server)
 {
 	NEGOTIATE_REQ *pSMB;
 	NEGOTIATE_RSP *pSMBr;
 	int rc = 0;
 	int bytes_returned;
 	int i;
-	struct TCP_Server_Info *server = ses->server;
 	u16 count;
 
 	if (!server) {
@@ -600,8 +647,12 @@ CIFSSMBTDis(const unsigned int xid, struct cifs_tcon *tcon)
 	 * the tcon is no longer on the list, so no need to take lock before
 	 * checking this.
 	 */
-	if ((tcon->need_reconnect) || (tcon->ses->need_reconnect))
-		return 0;
+	spin_lock(&tcon->ses->chan_lock);
+	if ((tcon->need_reconnect) || CIFS_ALL_CHANS_NEED_RECONNECT(tcon->ses)) {
+		spin_unlock(&tcon->ses->chan_lock);
+		return -EIO;
+	}
+	spin_unlock(&tcon->ses->chan_lock);
 
 	rc = small_smb_init(SMB_COM_TREE_DISCONNECT, 0, tcon,
 			    (void **)&smb_buffer);
@@ -696,9 +747,14 @@ CIFSSMBLogoff(const unsigned int xid, struct cifs_ses *ses)
 		return -EIO;
 
 	mutex_lock(&ses->session_mutex);
-	if (ses->need_reconnect)
+	spin_lock(&ses->chan_lock);
+	if (CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
+		spin_unlock(&ses->chan_lock);
 		goto session_already_dead; /* no need to send SMBlogoff if uid
 					      already closed due to reconnect */
+	}
+	spin_unlock(&ses->chan_lock);
+
 	rc = small_smb_init(SMB_COM_LOGOFF_ANDX, 2, NULL, (void **)&pSMB);
 	if (rc) {
 		mutex_unlock(&ses->session_mutex);
@@ -1401,7 +1457,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 
 	if (server->ops->is_session_expired &&
 	    server->ops->is_session_expired(buf)) {
-		cifs_reconnect(server);
+		cifs_reconnect(server, true);
 		return -1;
 	}
 

fs/cifs/netmisc.c

@@ -896,10 +896,10 @@ map_and_check_smb_error(struct mid_q_entry *mid, bool logErr)
 		if (class == ERRSRV && code == ERRbaduid) {
 			cifs_dbg(FYI, "Server returned 0x%x, reconnecting session...\n",
 				code);
-			spin_lock(&GlobalMid_Lock);
+			spin_lock(&cifs_tcp_ses_lock);
 			if (mid->server->tcpStatus != CifsExiting)
 				mid->server->tcpStatus = CifsNeedReconnect;
-			spin_unlock(&GlobalMid_Lock);
+			spin_unlock(&cifs_tcp_ses_lock);
 		}
 	}
 

fs/cifs/ntlmssp.h

@@ -121,7 +121,9 @@ typedef struct _AUTHENTICATE_MESSAGE {
 int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len, struct cifs_ses *ses);
 int build_ntlmssp_negotiate_blob(unsigned char **pbuffer, u16 *buflen,
 				 struct cifs_ses *ses,
+				 struct TCP_Server_Info *server,
 				 const struct nls_table *nls_cp);
 int build_ntlmssp_auth_blob(unsigned char **pbuffer, u16 *buflen,
 			struct cifs_ses *ses,
+			struct TCP_Server_Info *server,
 			const struct nls_table *nls_cp);

fs/cifs/smb1ops.c

@@ -7,6 +7,7 @@
 
 #include <linux/pagemap.h>
 #include <linux/vfs.h>
+#include <uapi/linux/magic.h>
 #include "cifsglob.h"
 #include "cifsproto.h"
 #include "cifs_debug.h"
@@ -163,7 +164,7 @@ cifs_get_next_mid(struct TCP_Server_Info *server)
 {
 	__u64 mid = 0;
 	__u16 last_mid, cur_mid;
-	bool collision;
+	bool collision, reconnect = false;
 
 	spin_lock(&GlobalMid_Lock);
 
@@ -215,7 +216,7 @@ cifs_get_next_mid(struct TCP_Server_Info *server)
 		 * an eventual reconnect to clean out the pending_mid_q.
 		 */
 		if (num_mids > 32768)
-			server->tcpStatus = CifsNeedReconnect;
+			reconnect = true;
 
 		if (!collision) {
 			mid = (__u64)cur_mid;
@@ -225,6 +226,13 @@ cifs_get_next_mid(struct TCP_Server_Info *server)
 		cur_mid++;
 	}
 	spin_unlock(&GlobalMid_Lock);
+
+	if (reconnect) {
+		spin_lock(&cifs_tcp_ses_lock);
+		server->tcpStatus = CifsNeedReconnect;
+		spin_unlock(&cifs_tcp_ses_lock);
+	}
+
 	return mid;
 }
 
@@ -414,14 +422,16 @@ cifs_need_neg(struct TCP_Server_Info *server)
 }
 
 static int
-cifs_negotiate(const unsigned int xid, struct cifs_ses *ses)
+cifs_negotiate(const unsigned int xid,
+	       struct cifs_ses *ses,
+	       struct TCP_Server_Info *server)
 {
 	int rc;
-	rc = CIFSSMBNegotiate(xid, ses);
+	rc = CIFSSMBNegotiate(xid, ses, server);
 	if (rc == -EAGAIN) {
 		/* retry only once on 1st time connection */
-		set_credits(ses->server, 1);
-		rc = CIFSSMBNegotiate(xid, ses);
+		set_credits(server, 1);
+		rc = CIFSSMBNegotiate(xid, ses, server);
 		if (rc == -EAGAIN)
 			rc = -EHOSTDOWN;
 	}
@@ -878,7 +888,7 @@ cifs_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 {
 	int rc = -EOPNOTSUPP;
 
-	buf->f_type = CIFS_MAGIC_NUMBER;
+	buf->f_type = CIFS_SUPER_MAGIC;
 
 	/*
 	 * We could add a second check for a QFS Unix capability bit

fs/cifs/smb2glob.h

@@ -13,8 +13,6 @@
 #ifndef _SMB2_GLOB_H
 #define _SMB2_GLOB_H
 
-#define SMB2_MAGIC_NUMBER 0xFE534D42
-
 /*
  *****************************************************************
  * Constants go here

fs/cifs/smb2misc.c

@@ -847,16 +847,17 @@ smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *serve
  * SMB2 header.
  *
  * @ses:	server session structure
+ * @server:	pointer to server info
  * @iov:	array containing the SMB request we will send to the server
  * @nvec:	number of array entries for the iov
  */
 int
-smb311_update_preauth_hash(struct cifs_ses *ses, struct kvec *iov, int nvec)
+smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
+			   struct kvec *iov, int nvec)
 {
 	int i, rc;
 	struct sdesc *d;
 	struct smb2_hdr *hdr;
-	struct TCP_Server_Info *server = cifs_ses_server(ses);
 
 	hdr = (struct smb2_hdr *)iov[0].iov_base;
 	/* neg prot are always taken */

fs/cifs/smb2ops.c

@@ -13,6 +13,7 @@
 #include <linux/sort.h>
 #include <crypto/aead.h>
 #include <linux/fiemap.h>
+#include <uapi/linux/magic.h>
 #include "cifsfs.h"
 #include "cifsglob.h"
 #include "smb2pdu.h"
@@ -121,9 +122,13 @@ smb2_add_credits(struct TCP_Server_Info *server,
 			 optype, scredits, add);
 	}
 
+	spin_lock(&cifs_tcp_ses_lock);
 	if (server->tcpStatus == CifsNeedReconnect
-	    || server->tcpStatus == CifsExiting)
+	    || server->tcpStatus == CifsExiting) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return;
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	switch (rc) {
 	case -1:
@@ -208,11 +213,15 @@ smb2_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
 				return rc;
 			spin_lock(&server->req_lock);
 		} else {
+			spin_unlock(&server->req_lock);
+			spin_lock(&cifs_tcp_ses_lock);
 			if (server->tcpStatus == CifsExiting) {
-				spin_unlock(&server->req_lock);
+				spin_unlock(&cifs_tcp_ses_lock);
 				return -ENOENT;
 			}
+			spin_unlock(&cifs_tcp_ses_lock);
 
+			spin_lock(&server->req_lock);
 			scredits = server->credits;
 			/* can deadlock with reopen */
 			if (scredits <= 8) {
@@ -384,14 +393,16 @@ smb2_need_neg(struct TCP_Server_Info *server)
 }
 
 static int
-smb2_negotiate(const unsigned int xid, struct cifs_ses *ses)
+smb2_negotiate(const unsigned int xid,
+	       struct cifs_ses *ses,
+	       struct TCP_Server_Info *server)
 {
 	int rc;
 
 	spin_lock(&GlobalMid_Lock);
-	cifs_ses_server(ses)->CurrentMid = 0;
+	server->CurrentMid = 0;
 	spin_unlock(&GlobalMid_Lock);
-	rc = SMB2_negotiate(xid, ses);
+	rc = SMB2_negotiate(xid, ses, server);
 	/* BB we probably don't need to retry with modern servers */
 	if (rc == -EAGAIN)
 		rc = -EHOSTDOWN;
@@ -2747,7 +2758,7 @@ smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 		goto qfs_exit;
 
 	rsp = (struct smb2_query_info_rsp *)rsp_iov.iov_base;
-	buf->f_type = SMB2_MAGIC_NUMBER;
+	buf->f_type = SMB2_SUPER_MAGIC;
 	info = (struct smb2_fs_full_size_info *)(
 		le16_to_cpu(rsp->OutputBufferOffset) + (char *)rsp);
 	rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
@@ -2789,7 +2800,7 @@ smb311_queryfs(const unsigned int xid, struct cifs_tcon *tcon,
 
 	rc = SMB311_posix_qfs_info(xid, tcon, fid.persistent_fid,
 				   fid.volatile_fid, buf);
-	buf->f_type = SMB2_MAGIC_NUMBER;
+	buf->f_type = SMB2_SUPER_MAGIC;
 	SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
 	return rc;
 }
@@ -4808,7 +4819,7 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
 	if (server->ops->is_session_expired &&
 	    server->ops->is_session_expired(buf)) {
 		if (!is_offloaded)
-			cifs_reconnect(server);
+			cifs_reconnect(server, true);
 		return -1;
 	}
 
@@ -4981,10 +4992,12 @@ static void smb2_decrypt_offload(struct work_struct *work)
 
 			mid->callback(mid);
 		} else {
+			spin_lock(&cifs_tcp_ses_lock);
 			spin_lock(&GlobalMid_Lock);
 			if (dw->server->tcpStatus == CifsNeedReconnect) {
 				mid->mid_state = MID_RETRY_NEEDED;
 				spin_unlock(&GlobalMid_Lock);
+				spin_unlock(&cifs_tcp_ses_lock);
 				mid->callback(mid);
 			} else {
 				mid->mid_state = MID_REQUEST_SUBMITTED;
@@ -4992,6 +5005,7 @@ static void smb2_decrypt_offload(struct work_struct *work)
 				list_add_tail(&mid->qhead,
 					&dw->server->pending_mid_q);
 				spin_unlock(&GlobalMid_Lock);
+				spin_unlock(&cifs_tcp_ses_lock);
 			}
 		}
 		cifs_mid_q_entry_release(mid);
@@ -5221,13 +5235,13 @@ smb3_receive_transform(struct TCP_Server_Info *server,
 						sizeof(struct smb2_hdr)) {
 		cifs_server_dbg(VFS, "Transform message is too small (%u)\n",
 			 pdu_length);
-		cifs_reconnect(server);
+		cifs_reconnect(server, true);
 		return -ECONNABORTED;
 	}
 
 	if (pdu_length < orig_len + sizeof(struct smb2_transform_hdr)) {
 		cifs_server_dbg(VFS, "Transform message is broken\n");
-		cifs_reconnect(server);
+		cifs_reconnect(server, true);
 		return -ECONNABORTED;
 	}
 

fs/cifs/smb2proto.h

@@ -123,8 +123,11 @@ extern void smb2_set_related(struct smb_rqst *rqst);
  * SMB2 Worker functions - most of protocol specific implementation details
  * are contained within these calls.
  */
-extern int SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses);
+extern int SMB2_negotiate(const unsigned int xid,
+			  struct cifs_ses *ses,
+			  struct TCP_Server_Info *server);
 extern int SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
+			   struct TCP_Server_Info *server,
 			   const struct nls_table *nls_cp);
 extern int SMB2_logoff(const unsigned int xid, struct cifs_ses *ses);
 extern int SMB2_tcon(const unsigned int xid, struct cifs_ses *ses,
@@ -276,6 +279,7 @@ extern void smb2_copy_fs_info_to_kstatfs(
 	 struct kstatfs *kst);
 extern int smb311_crypto_shash_allocate(struct TCP_Server_Info *server);
 extern int smb311_update_preauth_hash(struct cifs_ses *ses,
+				      struct TCP_Server_Info *server,
 				      struct kvec *iov, int nvec);
 extern int smb2_query_info_compound(const unsigned int xid,
 				    struct cifs_tcon *tcon,

fs/cifs/smb2transport.c

@@ -100,7 +100,8 @@ int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
 	goto out;
 
 found:
-	if (ses->binding) {
+	if (cifs_chan_needs_reconnect(ses, server) &&
+	    !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
 		/*
 		 * If we are in the process of binding a new channel
 		 * to an existing session, use the master connection
@@ -390,12 +391,18 @@ struct derivation_triplet {
 
 static int
 generate_smb3signingkey(struct cifs_ses *ses,
+			struct TCP_Server_Info *server,
 			const struct derivation_triplet *ptriplet)
 {
 	int rc;
-#ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
-	struct TCP_Server_Info *server = ses->server;
-#endif
+	bool is_binding = false;
+	int chan_index = 0;
+
+	spin_lock(&ses->chan_lock);
+	is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
+	chan_index = cifs_ses_get_chan_index(ses, server);
+	/* TODO: introduce ref counting for channels when the can be freed */
+	spin_unlock(&ses->chan_lock);
 
 	/*
 	 * All channels use the same encryption/decryption keys but
@@ -407,10 +414,10 @@ generate_smb3signingkey(struct cifs_ses *ses,
 	 * master connection signing key stored in the session
 	 */
 
-	if (ses->binding) {
+	if (is_binding) {
 		rc = generate_key(ses, ptriplet->signing.label,
 				  ptriplet->signing.context,
-				  cifs_ses_binding_channel(ses)->signkey,
+				  ses->chans[chan_index].signkey,
 				  SMB3_SIGN_KEY_SIZE);
 		if (rc)
 			return rc;
@@ -422,6 +429,7 @@ generate_smb3signingkey(struct cifs_ses *ses,
 		if (rc)
 			return rc;
 
+		/* safe to access primary channel, since it will never go away */
 		memcpy(ses->chans[0].signkey, ses->smb3signingkey,
 		       SMB3_SIGN_KEY_SIZE);
 
@@ -470,7 +478,8 @@ generate_smb3signingkey(struct cifs_ses *ses,
 }
 
 int
-generate_smb30signingkey(struct cifs_ses *ses)
+generate_smb30signingkey(struct cifs_ses *ses,
+			 struct TCP_Server_Info *server)
 
 {
 	struct derivation_triplet triplet;
@@ -494,11 +503,12 @@ generate_smb30signingkey(struct cifs_ses *ses)
 	d->context.iov_base = "ServerOut";
 	d->context.iov_len = 10;
 
-	return generate_smb3signingkey(ses, &triplet);
+	return generate_smb3signingkey(ses, server, &triplet);
 }
 
 int
-generate_smb311signingkey(struct cifs_ses *ses)
+generate_smb311signingkey(struct cifs_ses *ses,
+			  struct TCP_Server_Info *server)
 
 {
 	struct derivation_triplet triplet;
@@ -522,7 +532,7 @@ generate_smb311signingkey(struct cifs_ses *ses)
 	d->context.iov_base = ses->preauth_sha_hash;
 	d->context.iov_len = 64;
 
-	return generate_smb3signingkey(ses, &triplet);
+	return generate_smb3signingkey(ses, server, &triplet);
 }
 
 int
@@ -624,8 +634,12 @@ smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 
 	if (!is_signed)
 		return 0;
-	if (server->tcpStatus == CifsNeedNegotiate)
+	spin_lock(&cifs_tcp_ses_lock);
+	if (server->tcpStatus == CifsNeedNegotiate) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return 0;
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
 	if (!is_binding && !server->session_estab) {
 		strncpy(shdr->Signature, "BSRSPYL", 8);
 		return 0;
@@ -741,30 +755,41 @@ static int
 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server,
 		   struct smb2_hdr *shdr, struct mid_q_entry **mid)
 {
-	if (server->tcpStatus == CifsExiting)
+	spin_lock(&cifs_tcp_ses_lock);
+	if (server->tcpStatus == CifsExiting) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return -ENOENT;
+	}
 
 	if (server->tcpStatus == CifsNeedReconnect) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
 		return -EAGAIN;
 	}
 
 	if (server->tcpStatus == CifsNeedNegotiate &&
-	   shdr->Command != SMB2_NEGOTIATE)
+	   shdr->Command != SMB2_NEGOTIATE) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return -EAGAIN;
+	}
 
 	if (ses->status == CifsNew) {
 		if ((shdr->Command != SMB2_SESSION_SETUP) &&
-		    (shdr->Command != SMB2_NEGOTIATE))
+		    (shdr->Command != SMB2_NEGOTIATE)) {
+			spin_unlock(&cifs_tcp_ses_lock);
 			return -EAGAIN;
+		}
 		/* else ok - we are setting up session */
 	}
 
 	if (ses->status == CifsExiting) {
-		if (shdr->Command != SMB2_LOGOFF)
+		if (shdr->Command != SMB2_LOGOFF) {
+			spin_unlock(&cifs_tcp_ses_lock);
 			return -EAGAIN;
+		}
 		/* else ok - we are shutting down the session */
 	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	*mid = smb2_mid_entry_alloc(shdr, server);
 	if (*mid == NULL)
@@ -837,9 +862,13 @@ smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 			(struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 	struct mid_q_entry *mid;
 
+	spin_lock(&cifs_tcp_ses_lock);
 	if (server->tcpStatus == CifsNeedNegotiate &&
-	   shdr->Command != SMB2_NEGOTIATE)
+	   shdr->Command != SMB2_NEGOTIATE) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return ERR_PTR(-EAGAIN);
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	smb2_seq_num_into_buf(server, shdr);
 

fs/cifs/transport.c

@@ -430,9 +430,9 @@ __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 		 * be taken as the remainder of this one. We need to kill the
 		 * socket so the server throws away the partial SMB
 		 */
-		spin_lock(&GlobalMid_Lock);
+		spin_lock(&cifs_tcp_ses_lock);
 		server->tcpStatus = CifsNeedReconnect;
-		spin_unlock(&GlobalMid_Lock);
+		spin_unlock(&cifs_tcp_ses_lock);
 		trace_smb3_partial_send_reconnect(server->CurrentMid,
 						  server->conn_id, server->hostname);
 	}
@@ -578,10 +578,14 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
 				return -ERESTARTSYS;
 			spin_lock(&server->req_lock);
 		} else {
+			spin_unlock(&server->req_lock);
+
+			spin_lock(&cifs_tcp_ses_lock);
 			if (server->tcpStatus == CifsExiting) {
-				spin_unlock(&server->req_lock);
+				spin_unlock(&cifs_tcp_ses_lock);
 				return -ENOENT;
 			}
+			spin_unlock(&cifs_tcp_ses_lock);
 
 			/*
 			 * For normal commands, reserve the last MAX_COMPOUND
@@ -596,6 +600,7 @@ wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
 			 * for servers that are slow to hand out credits on
 			 * new sessions.
 			 */
+			spin_lock(&server->req_lock);
 			if (!optype && num_credits == 1 &&
 			    server->in_flight > 2 * MAX_COMPOUND &&
 			    *credits <= MAX_COMPOUND) {
@@ -723,28 +728,36 @@ cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
 			struct mid_q_entry **ppmidQ)
 {
+	spin_lock(&cifs_tcp_ses_lock);
 	if (ses->server->tcpStatus == CifsExiting) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return -ENOENT;
 	}
 
 	if (ses->server->tcpStatus == CifsNeedReconnect) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
 		return -EAGAIN;
 	}
 
 	if (ses->status == CifsNew) {
 		if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
-			(in_buf->Command != SMB_COM_NEGOTIATE))
+			(in_buf->Command != SMB_COM_NEGOTIATE)) {
+			spin_unlock(&cifs_tcp_ses_lock);
 			return -EAGAIN;
+		}
 		/* else ok - we are setting up session */
 	}
 
 	if (ses->status == CifsExiting) {
 		/* check if SMB session is bad because we are setting it up */
-		if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
+		if (in_buf->Command != SMB_COM_LOGOFF_ANDX) {
+			spin_unlock(&cifs_tcp_ses_lock);
 			return -EAGAIN;
+		}
 		/* else ok - we are shutting down session */
 	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	*ppmidQ = AllocMidQEntry(in_buf, ses->server);
 	if (*ppmidQ == NULL)
@@ -1044,19 +1057,11 @@ struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
 	if (!ses)
 		return NULL;
 
-	spin_lock(&ses->chan_lock);
-	if (!ses->binding) {
-		/* round robin */
-		if (ses->chan_count > 1) {
-			index = (uint)atomic_inc_return(&ses->chan_seq);
-			index %= ses->chan_count;
-		}
-		spin_unlock(&ses->chan_lock);
-		return ses->chans[index].server;
-	} else {
-		spin_unlock(&ses->chan_lock);
-		return cifs_ses_server(ses);
-	}
+	/* round robin */
+	index = (uint)atomic_inc_return(&ses->chan_seq);
+	index %= ses->chan_count;
+
+	return ses->chans[index].server;
 }
 
 int
@@ -1084,8 +1089,12 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		return -EIO;
 	}
 
-	if (server->tcpStatus == CifsExiting)
+	spin_lock(&cifs_tcp_ses_lock);
+	if (server->tcpStatus == CifsExiting) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return -ENOENT;
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	/*
 	 * Wait for all the requests to become available.
@@ -1188,12 +1197,17 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 	/*
 	 * Compounding is never used during session establish.
 	 */
+	spin_lock(&cifs_tcp_ses_lock);
 	if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
+		spin_unlock(&cifs_tcp_ses_lock);
+
 		mutex_lock(&server->srv_mutex);
-		smb311_update_preauth_hash(ses, rqst[0].rq_iov,
-					   rqst[0].rq_nvec);
+		smb311_update_preauth_hash(ses, server, rqst[0].rq_iov, rqst[0].rq_nvec);
 		mutex_unlock(&server->srv_mutex);
+
+		spin_lock(&cifs_tcp_ses_lock);
 	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	for (i = 0; i < num_rqst; i++) {
 		rc = wait_for_response(server, midQ[i]);
@@ -1256,15 +1270,19 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 	/*
 	 * Compounding is never used during session establish.
 	 */
+	spin_lock(&cifs_tcp_ses_lock);
 	if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
 		struct kvec iov = {
 			.iov_base = resp_iov[0].iov_base,
 			.iov_len = resp_iov[0].iov_len
 		};
+		spin_unlock(&cifs_tcp_ses_lock);
 		mutex_lock(&server->srv_mutex);
-		smb311_update_preauth_hash(ses, &iov, 1);
+		smb311_update_preauth_hash(ses, server, &iov, 1);
 		mutex_unlock(&server->srv_mutex);
+		spin_lock(&cifs_tcp_ses_lock);
 	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 out:
 	/*
@@ -1353,8 +1371,12 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
 		return -EIO;
 	}
 
-	if (server->tcpStatus == CifsExiting)
+	spin_lock(&cifs_tcp_ses_lock);
+	if (server->tcpStatus == CifsExiting) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return -ENOENT;
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	/* Ensure that we do not send more than 50 overlapping requests
 	   to the same server. We may make this configurable later or
@@ -1494,8 +1516,12 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 		return -EIO;
 	}
 
-	if (server->tcpStatus == CifsExiting)
+	spin_lock(&cifs_tcp_ses_lock);
+	if (server->tcpStatus == CifsExiting) {
+		spin_unlock(&cifs_tcp_ses_lock);
 		return -ENOENT;
+	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	/* Ensure that we do not send more than 50 overlapping requests
 	   to the same server. We may make this configurable later or
@@ -1553,10 +1579,12 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 		 (server->tcpStatus != CifsNew)));
 
 	/* Were we interrupted by a signal ? */
+	spin_lock(&cifs_tcp_ses_lock);
 	if ((rc == -ERESTARTSYS) &&
 		(midQ->mid_state == MID_REQUEST_SUBMITTED) &&
 		((server->tcpStatus == CifsGood) ||
 		 (server->tcpStatus == CifsNew))) {
+		spin_unlock(&cifs_tcp_ses_lock);
 
 		if (in_buf->Command == SMB_COM_TRANSACTION2) {
 			/* POSIX lock. We send a NT_CANCEL SMB to cause the
@@ -1595,7 +1623,9 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
 
 		/* We got the response - restart system call. */
 		rstart = 1;
+		spin_lock(&cifs_tcp_ses_lock);
 	}
+	spin_unlock(&cifs_tcp_ses_lock);
 
 	rc = cifs_sync_mid_result(midQ, server);
 	if (rc != 0)

include/uapi/linux/magic.h

@@ -52,6 +52,7 @@
 #define QNX6_SUPER_MAGIC	0x68191122	/* qnx6 fs detection */
 #define AFS_FS_MAGIC		0x6B414653
 
+
 #define REISERFS_SUPER_MAGIC	0x52654973	/* used by gcc */
 					/* used by file system utilities that
 	                                   look at the superblock, etc.  */
@@ -60,6 +61,9 @@
 #define REISER2FS_JR_SUPER_MAGIC_STRING	"ReIsEr3Fs"
 
 #define SMB_SUPER_MAGIC		0x517B
+#define CIFS_SUPER_MAGIC	0xFF534D42      /* the first four bytes of SMB PDUs */
+#define SMB2_SUPER_MAGIC	0xFE534D42
+
 #define CGROUP_SUPER_MAGIC	0x27e0eb
 #define CGROUP2_SUPER_MAGIC	0x63677270