Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
  [CIFS] Fix multiuser mounts so server does not invalidate earlier security contexts
  [CIFS] improve posix semantics of file create
  [CIFS] Fix oops in cifs_strfromUCS_le mounting to servers which do not specify their OS
  cifs: posix fill in inode needed by posix open
  cifs: properly handle case where CIFSGetSrvInodeNumber fails
  cifs: refactor new_inode() calls and inode initialization
  [CIFS] Prevent OOPs when mounting with remote prefixpath.
  [CIFS] ipv6_addr_equal for address comparison

fs/cifs/CHANGES

+Version 1.57
+------------
+Improve support for multiple security contexts to the same server. We
+used to use the same "vcnumber" for all connections which could cause
+the server to treat subsequent connections, especially those that
+are authenticated as guest, as reconnections, invalidating the earlier
+user's smb session.  This fix allows cifs to mount multiple times to the
+same server with different userids without risking invalidating earlier
+established security contexts.
+
 Version 1.56
 ------------
 Add "forcemandatorylock" mount option to allow user to use mandatory
@@ -7,7 +17,10 @@ specified and user does not have access to query information about the
 top of the share.  Fix problem in 2.6.28 resolving DFS paths to
 Samba servers (worked to Windows).  Fix rmdir so that pending search
 (readdir) requests do not get invalid results which include the now
-removed directory.
+removed directory.  Fix oops in cifs_dfs_ref.c when prefixpath is not reachable
+when using DFS.  Add better file create support to servers which support
+the CIFS POSIX protocol extensions (this adds support for new flags
+on create, and improves semantics for write of locked ranges).
 
 Version 1.55
 ------------

fs/cifs/cifsfs.h

@@ -100,5 +100,5 @@ extern long cifs_ioctl(struct file *filep, unsigned int cmd, unsigned long arg);
 extern const struct export_operations cifs_export_ops;
 #endif /* EXPERIMENTAL */
 
-#define CIFS_VERSION   "1.56"
+#define CIFS_VERSION   "1.57"
 #endif				/* _CIFSFS_H */

fs/cifs/cifsglob.h

@@ -164,9 +164,12 @@ struct TCP_Server_Info {
 	/* multiplexed reads or writes */
 	unsigned int maxBuf;	/* maxBuf specifies the maximum */
 	/* message size the server can send or receive for non-raw SMBs */
-	unsigned int maxRw;	/* maxRw specifies the maximum */
+	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 */
 	char sessid[4];		/* unique token id for this session */
 	/* (returned on Negotiate */
 	int capabilities; /* allow selective disabling of caps by smb sess */
@@ -210,6 +213,7 @@ struct cifsSesInfo {
 	unsigned overrideSecFlg;  /* if non-zero override global sec flags */
 	__u16 ipc_tid;		/* special tid for connection to IPC share */
 	__u16 flags;
+	__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 */

fs/cifs/cifsproto.h

@@ -42,6 +42,7 @@ extern void _FreeXid(unsigned int);
 #define GetXid() (int)_GetXid(); cFYI(1,("CIFS VFS: in %s as Xid: %d with uid: %d",__func__, xid,current_fsuid()));
 #define FreeXid(curr_xid) {_FreeXid(curr_xid); cFYI(1,("CIFS VFS: leaving %s (xid = %d) rc = %d",__func__,curr_xid,(int)rc));}
 extern char *build_path_from_dentry(struct dentry *);
+extern char *cifs_build_path_to_root(struct cifs_sb_info *cifs_sb);
 extern char *build_wildcard_path_from_dentry(struct dentry *direntry);
 /* extern void renew_parental_timestamps(struct dentry *direntry);*/
 extern int SendReceive(const unsigned int /* xid */ , struct cifsSesInfo *,
@@ -91,6 +92,9 @@ extern u64 cifs_UnixTimeToNT(struct timespec);
 extern __le64 cnvrtDosCifsTm(__u16 date, __u16 time);
 extern struct timespec cnvrtDosUnixTm(__u16 date, __u16 time);
 
+extern void posix_fill_in_inode(struct inode *tmp_inode,
+				FILE_UNIX_BASIC_INFO *pData, int isNewInode);
+extern struct inode *cifs_new_inode(struct super_block *sb, __u64 *inum);
 extern int cifs_get_inode_info(struct inode **pinode,
 			const unsigned char *search_path,
 			FILE_ALL_INFO *pfile_info,

fs/cifs/cifssmb.c

@@ -528,14 +528,15 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 		server->maxReq = le16_to_cpu(rsp->MaxMpxCount);
 		server->maxBuf = min((__u32)le16_to_cpu(rsp->MaxBufSize),
 				(__u32)CIFSMaxBufSize + MAX_CIFS_HDR_SIZE);
+		server->max_vcs = le16_to_cpu(rsp->MaxNumberVcs);
 		GETU32(server->sessid) = le32_to_cpu(rsp->SessionKey);
 		/* even though we do not use raw we might as well set this
 		accurately, in case we ever find a need for it */
 		if ((le16_to_cpu(rsp->RawMode) & RAW_ENABLE) == RAW_ENABLE) {
-			server->maxRw = 0xFF00;
+			server->max_rw = 0xFF00;
 			server->capabilities = CAP_MPX_MODE | CAP_RAW_MODE;
 		} else {
-			server->maxRw = 0;/* we do not need to use raw anyway */
+			server->max_rw = 0;/* do not need to use raw anyway */
 			server->capabilities = CAP_MPX_MODE;
 		}
 		tmp = (__s16)le16_to_cpu(rsp->ServerTimeZone);
@@ -638,7 +639,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 	/* probably no need to store and check maxvcs */
 	server->maxBuf = min(le32_to_cpu(pSMBr->MaxBufferSize),
 			(__u32) CIFSMaxBufSize + MAX_CIFS_HDR_SIZE);
-	server->maxRw = le32_to_cpu(pSMBr->MaxRawSize);
+	server->max_rw = le32_to_cpu(pSMBr->MaxRawSize);
 	cFYI(DBG2, ("Max buf = %d", ses->server->maxBuf));
 	GETU32(ses->server->sessid) = le32_to_cpu(pSMBr->SessionKey);
 	server->capabilities = le32_to_cpu(pSMBr->Capabilities);

fs/cifs/connect.c

@@ -23,7 +23,6 @@
 #include <linux/string.h>
 #include <linux/list.h>
 #include <linux/wait.h>
-#include <linux/ipv6.h>
 #include <linux/pagemap.h>
 #include <linux/ctype.h>
 #include <linux/utsname.h>
@@ -35,6 +34,7 @@
 #include <linux/freezer.h>
 #include <asm/uaccess.h>
 #include <asm/processor.h>
+#include <net/ipv6.h>
 #include "cifspdu.h"
 #include "cifsglob.h"
 #include "cifsproto.h"
@@ -1379,8 +1379,8 @@ cifs_find_tcp_session(struct sockaddr_storage *addr)
 		     server->addr.sockAddr.sin_addr.s_addr))
 			continue;
 		else if (addr->ss_family == AF_INET6 &&
-			 memcmp(&server->addr.sockAddr6.sin6_addr,
-				&addr6->sin6_addr, sizeof(addr6->sin6_addr)))
+			 !ipv6_addr_equal(&server->addr.sockAddr6.sin6_addr,
+					  &addr6->sin6_addr))
 			continue;
 
 		++server->srv_count;
@@ -2180,6 +2180,33 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info,
 			   "mount option supported"));
 }
 
+static int
+is_path_accessible(int xid, struct cifsTconInfo *tcon,
+		   struct cifs_sb_info *cifs_sb, const char *full_path)
+{
+	int rc;
+	__u64 inode_num;
+	FILE_ALL_INFO *pfile_info;
+
+	rc = CIFSGetSrvInodeNumber(xid, tcon, full_path, &inode_num,
+				   cifs_sb->local_nls,
+				   cifs_sb->mnt_cifs_flags &
+						CIFS_MOUNT_MAP_SPECIAL_CHR);
+	if (rc != -EOPNOTSUPP)
+		return rc;
+
+	pfile_info = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
+	if (pfile_info == NULL)
+		return -ENOMEM;
+
+	rc = CIFSSMBQPathInfo(xid, tcon, full_path, pfile_info,
+			      0 /* not legacy */, cifs_sb->local_nls,
+			      cifs_sb->mnt_cifs_flags &
+				CIFS_MOUNT_MAP_SPECIAL_CHR);
+	kfree(pfile_info);
+	return rc;
+}
+
 int
 cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 	   char *mount_data, const char *devname)
@@ -2190,6 +2217,7 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 	struct cifsSesInfo *pSesInfo = NULL;
 	struct cifsTconInfo *tcon = NULL;
 	struct TCP_Server_Info *srvTcp = NULL;
+	char   *full_path;
 
 	xid = GetXid();
 
@@ -2426,6 +2454,23 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 		cifs_sb->rsize = min(cifs_sb->rsize,
 			       (tcon->ses->server->maxBuf - MAX_CIFS_HDR_SIZE));
 
+	if (!rc && cifs_sb->prepathlen) {
+		/* build_path_to_root works only when we have a valid tcon */
+		full_path = cifs_build_path_to_root(cifs_sb);
+		if (full_path == NULL) {
+			rc = -ENOMEM;
+			goto mount_fail_check;
+		}
+		rc = is_path_accessible(xid, tcon, cifs_sb, full_path);
+		if (rc) {
+			cERROR(1, ("Path %s in not accessible: %d",
+						full_path, rc));
+			kfree(full_path);
+			goto mount_fail_check;
+		}
+		kfree(full_path);
+	}
+
 	/* volume_info->password is freed above when existing session found
 	(in which case it is not needed anymore) but when new sesion is created
 	the password ptr is put in the new session structure (in which case the

fs/cifs/inode.c

@@ -199,6 +199,49 @@ static void fill_fake_finddataunix(FILE_UNIX_BASIC_INFO *pfnd_dat,
 	pfnd_dat->Gid = cpu_to_le64(pinode->i_gid);
 }
 
+/**
+ * cifs_new inode - create new inode, initialize, and hash it
+ * @sb - pointer to superblock
+ * @inum - if valid pointer and serverino is enabled, replace i_ino with val
+ *
+ * Create a new inode, initialize it for CIFS and hash it. Returns the new
+ * inode or NULL if one couldn't be allocated.
+ *
+ * If the share isn't mounted with "serverino" or inum is a NULL pointer then
+ * we'll just use the inode number assigned by new_inode(). Note that this can
+ * mean i_ino collisions since the i_ino assigned by new_inode is not
+ * guaranteed to be unique.
+ */
+struct inode *
+cifs_new_inode(struct super_block *sb, __u64 *inum)
+{
+	struct inode *inode;
+
+	inode = new_inode(sb);
+	if (inode == NULL)
+		return NULL;
+
+	/*
+	 * BB: Is i_ino == 0 legal? Here, we assume that it is. If it isn't we
+	 *     stop passing inum as ptr. Are there sanity checks we can use to
+	 *     ensure that the server is really filling in that field? Also,
+	 *     if serverino is disabled, perhaps we should be using iunique()?
+	 */
+	if (inum && (CIFS_SB(sb)->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
+		inode->i_ino = (unsigned long) *inum;
+
+	/*
+	 * must set this here instead of cifs_alloc_inode since VFS will
+	 * clobber i_flags
+	 */
+	if (sb->s_flags & MS_NOATIME)
+		inode->i_flags |= S_NOATIME | S_NOCMTIME;
+
+	insert_inode_hash(inode);
+
+	return inode;
+}
+
 int cifs_get_inode_info_unix(struct inode **pinode,
 	const unsigned char *full_path, struct super_block *sb, int xid)
 {
@@ -233,22 +276,11 @@ int cifs_get_inode_info_unix(struct inode **pinode,
 
 	/* get new inode */
 	if (*pinode == NULL) {
-		*pinode = new_inode(sb);
+		*pinode = cifs_new_inode(sb, &find_data.UniqueId);
 		if (*pinode == NULL) {
 			rc = -ENOMEM;
 			goto cgiiu_exit;
 		}
-		/* Is an i_ino of zero legal? */
-		/* note ino incremented to unique num in new_inode */
-		/* Are there sanity checks we can use to ensure that
-		   the server is really filling in that field? */
-		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
-			(*pinode)->i_ino = (unsigned long)find_data.UniqueId;
-
-		if (sb->s_flags & MS_NOATIME)
-			(*pinode)->i_flags |= S_NOATIME | S_NOCMTIME;
-
-		insert_inode_hash(*pinode);
 	}
 
 	inode = *pinode;
@@ -465,11 +497,9 @@ int cifs_get_inode_info(struct inode **pinode,
 
 	/* get new inode */
 	if (*pinode == NULL) {
-		*pinode = new_inode(sb);
-		if (*pinode == NULL) {
-			rc = -ENOMEM;
-			goto cgii_exit;
-		}
+		__u64 inode_num;
+		__u64 *pinum = &inode_num;
+
 		/* Is an i_ino of zero legal? Can we use that to check
 		   if the server supports returning inode numbers?  Are
 		   there other sanity checks we can use to ensure that
@@ -486,22 +516,26 @@ int cifs_get_inode_info(struct inode **pinode,
 
 		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
 			int rc1 = 0;
-			__u64 inode_num;
 
 			rc1 = CIFSGetSrvInodeNumber(xid, pTcon,
-					full_path, &inode_num,
+					full_path, pinum,
 					cifs_sb->local_nls,
 					cifs_sb->mnt_cifs_flags &
 						CIFS_MOUNT_MAP_SPECIAL_CHR);
 			if (rc1) {
 				cFYI(1, ("GetSrvInodeNum rc %d", rc1));
+				pinum = NULL;
 				/* BB EOPNOSUPP disable SERVER_INUM? */
-			} else /* do we need cast or hash to ino? */
-				(*pinode)->i_ino = inode_num;
-		} /* else ino incremented to unique num in new_inode*/
-		if (sb->s_flags & MS_NOATIME)
-			(*pinode)->i_flags |= S_NOATIME | S_NOCMTIME;
-		insert_inode_hash(*pinode);
+			}
+		} else {
+			pinum = NULL;
+		}
+
+		*pinode = cifs_new_inode(sb, pinum);
+		if (*pinode == NULL) {
+			rc = -ENOMEM;
+			goto cgii_exit;
+		}
 	}
 	inode = *pinode;
 	cifsInfo = CIFS_I(inode);
@@ -621,7 +655,7 @@ static const struct inode_operations cifs_ipc_inode_ops = {
 	.lookup = cifs_lookup,
 };
 
-static char *build_path_to_root(struct cifs_sb_info *cifs_sb)
+char *cifs_build_path_to_root(struct cifs_sb_info *cifs_sb)
 {
 	int pplen = cifs_sb->prepathlen;
 	int dfsplen;
@@ -678,7 +712,7 @@ struct inode *cifs_iget(struct super_block *sb, unsigned long ino)
 		return inode;
 
 	cifs_sb = CIFS_SB(inode->i_sb);
-	full_path = build_path_to_root(cifs_sb);
+	full_path = cifs_build_path_to_root(cifs_sb);
 	if (full_path == NULL)
 		return ERR_PTR(-ENOMEM);
 
@@ -1017,7 +1051,7 @@ int cifs_unlink(struct inode *dir, struct dentry *dentry)
 	return rc;
 }
 
-static void posix_fill_in_inode(struct inode *tmp_inode,
+void posix_fill_in_inode(struct inode *tmp_inode,
 	FILE_UNIX_BASIC_INFO *pData, int isNewInode)
 {
 	struct cifsInodeInfo *cifsInfo = CIFS_I(tmp_inode);
@@ -1114,24 +1148,14 @@ int cifs_mkdir(struct inode *inode, struct dentry *direntry, int mode)
 			else
 				direntry->d_op = &cifs_dentry_ops;
 
-			newinode = new_inode(inode->i_sb);
+			newinode = cifs_new_inode(inode->i_sb,
+						  &pInfo->UniqueId);
 			if (newinode == NULL) {
 				kfree(pInfo);
 				goto mkdir_get_info;
 			}
 
-			/* Is an i_ino of zero legal? */
-			/* Are there sanity checks we can use to ensure that
-			   the server is really filling in that field? */
-			if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
-				newinode->i_ino =
-					(unsigned long)pInfo->UniqueId;
-			} /* note ino incremented to unique num in new_inode */
-			if (inode->i_sb->s_flags & MS_NOATIME)
-				newinode->i_flags |= S_NOATIME | S_NOCMTIME;
 			newinode->i_nlink = 2;
-
-			insert_inode_hash(newinode);
 			d_instantiate(direntry, newinode);
 
 			/* we already checked in POSIXCreate whether

fs/cifs/readdir.c

@@ -56,35 +56,34 @@ static inline void dump_cifs_file_struct(struct file *file, char *label)
 }
 #endif /* DEBUG2 */
 
-/* Returns one if new inode created (which therefore needs to be hashed) */
+/* Returns 1 if new inode created, 2 if both dentry and inode were */
 /* Might check in the future if inode number changed so we can rehash inode */
-static int construct_dentry(struct qstr *qstring, struct file *file,
-	struct inode **ptmp_inode, struct dentry **pnew_dentry)
+static int
+construct_dentry(struct qstr *qstring, struct file *file,
+		 struct inode **ptmp_inode, struct dentry **pnew_dentry,
+		 __u64 *inum)
 {
-	struct dentry *tmp_dentry;
-	struct cifs_sb_info *cifs_sb;
-	struct cifsTconInfo *pTcon;
+	struct dentry *tmp_dentry = NULL;
+	struct super_block *sb = file->f_path.dentry->d_sb;
 	int rc = 0;
 
 	cFYI(1, ("For %s", qstring->name));
-	cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
-	pTcon = cifs_sb->tcon;
 
 	qstring->hash = full_name_hash(qstring->name, qstring->len);
 	tmp_dentry = d_lookup(file->f_path.dentry, qstring);
 	if (tmp_dentry) {
+		/* BB: overwrite old name? i.e. tmp_dentry->d_name and
+		 * tmp_dentry->d_name.len??
+		 */
 		cFYI(0, ("existing dentry with inode 0x%p",
 			 tmp_dentry->d_inode));
 		*ptmp_inode = tmp_dentry->d_inode;
-/* BB overwrite old name? i.e. tmp_dentry->d_name and tmp_dentry->d_name.len??*/
 		if (*ptmp_inode == NULL) {
-			*ptmp_inode = new_inode(file->f_path.dentry->d_sb);
+			*ptmp_inode = cifs_new_inode(sb, inum);
 			if (*ptmp_inode == NULL)
 				return rc;
 			rc = 1;
 		}
-		if (file->f_path.dentry->d_sb->s_flags & MS_NOATIME)
-			(*ptmp_inode)->i_flags |= S_NOATIME | S_NOCMTIME;
 	} else {
 		tmp_dentry = d_alloc(file->f_path.dentry, qstring);
 		if (tmp_dentry == NULL) {
@@ -93,15 +92,14 @@ static int construct_dentry(struct qstr *qstring, struct file *file,
 			return rc;
 		}
 
-		*ptmp_inode = new_inode(file->f_path.dentry->d_sb);
-		if (pTcon->nocase)
+		if (CIFS_SB(sb)->tcon->nocase)
 			tmp_dentry->d_op = &cifs_ci_dentry_ops;
 		else
 			tmp_dentry->d_op = &cifs_dentry_ops;
+
+		*ptmp_inode = cifs_new_inode(sb, inum);
 		if (*ptmp_inode == NULL)
 			return rc;
-		if (file->f_path.dentry->d_sb->s_flags & MS_NOATIME)
-			(*ptmp_inode)->i_flags |= S_NOATIME | S_NOCMTIME;
 		rc = 2;
 	}
 
@@ -822,7 +820,7 @@ static int find_cifs_entry(const int xid, struct cifsTconInfo *pTcon,
 /* inode num, inode type and filename returned */
 static int cifs_get_name_from_search_buf(struct qstr *pqst,
 	char *current_entry, __u16 level, unsigned int unicode,
-	struct cifs_sb_info *cifs_sb, int max_len, ino_t *pinum)
+	struct cifs_sb_info *cifs_sb, int max_len, __u64 *pinum)
 {
 	int rc = 0;
 	unsigned int len = 0;
@@ -842,9 +840,7 @@ static int cifs_get_name_from_search_buf(struct qstr *pqst,
 			len = strnlen(filename, PATH_MAX);
 		}
 
-		/* BB fixme - hash low and high 32 bits if not 64 bit arch BB */
-		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)
-			*pinum = pFindData->UniqueId;
+		*pinum = pFindData->UniqueId;
 	} else if (level == SMB_FIND_FILE_DIRECTORY_INFO) {
 		FILE_DIRECTORY_INFO *pFindData =
 			(FILE_DIRECTORY_INFO *)current_entry;
@@ -907,7 +903,7 @@ static int cifs_filldir(char *pfindEntry, struct file *file,
 	struct qstr qstring;
 	struct cifsFileInfo *pCifsF;
 	unsigned int obj_type;
-	ino_t  inum;
+	__u64  inum;
 	struct cifs_sb_info *cifs_sb;
 	struct inode *tmp_inode;
 	struct dentry *tmp_dentry;
@@ -940,20 +936,18 @@ static int cifs_filldir(char *pfindEntry, struct file *file,
 	if (rc)
 		return rc;
 
-	rc = construct_dentry(&qstring, file, &tmp_inode, &tmp_dentry);
+	/* only these two infolevels return valid inode numbers */
+	if (pCifsF->srch_inf.info_level == SMB_FIND_FILE_UNIX ||
+	    pCifsF->srch_inf.info_level == SMB_FIND_FILE_ID_FULL_DIR_INFO)
+		rc = construct_dentry(&qstring, file, &tmp_inode, &tmp_dentry,
+					&inum);
+	else
+		rc = construct_dentry(&qstring, file, &tmp_inode, &tmp_dentry,
+					NULL);
+
 	if ((tmp_inode == NULL) || (tmp_dentry == NULL))
 		return -ENOMEM;
 
-	if (rc) {
-		/* inode created, we need to hash it with right inode number */
-		if (inum != 0) {
-			/* BB fixme - hash the 2 32 quantities bits together if
-			 *  necessary BB */
-			tmp_inode->i_ino = inum;
-		}
-		insert_inode_hash(tmp_inode);
-	}
-
 	/* we pass in rc below, indicating whether it is a new inode,
 	   so we can figure out whether to invalidate the inode cached
 	   data if the file has changed */

fs/cifs/sess.c

@@ -34,15 +34,99 @@
 extern void SMBNTencrypt(unsigned char *passwd, unsigned char *c8,
 			 unsigned char *p24);
 
+/* Checks if this is the first smb session to be reconnected after
+   the socket has been reestablished (so we know whether to use vc 0).
+   Called while holding the cifs_tcp_ses_lock, so do not block */
+static bool is_first_ses_reconnect(struct cifsSesInfo *ses)
+{
+	struct list_head *tmp;
+	struct cifsSesInfo *tmp_ses;
+
+	list_for_each(tmp, &ses->server->smb_ses_list) {
+		tmp_ses = list_entry(tmp, struct cifsSesInfo,
+				     smb_ses_list);
+		if (tmp_ses->need_reconnect == false)
+			return false;
+	}
+	/* could not find a session that was already connected,
+	   this must be the first one we are reconnecting */
+	return true;
+}
+
+/*
+ *	vc number 0 is treated specially by some servers, and should be the
+ *      first one we request.  After that we can use vcnumbers up to maxvcs,
+ *	one for each smb session (some Windows versions set maxvcs incorrectly
+ *	so maxvc=1 can be ignored).  If we have too many vcs, we can reuse
+ *	any vc but zero (some servers reset the connection on vcnum zero)
+ *
+ */
+static __le16 get_next_vcnum(struct cifsSesInfo *ses)
+{
+	__u16 vcnum = 0;
+	struct list_head *tmp;
+	struct cifsSesInfo *tmp_ses;
+	__u16 max_vcs = ses->server->max_vcs;
+	__u16 i;
+	int free_vc_found = 0;
+
+	/* Quoting the MS-SMB specification: "Windows-based SMB servers set this
+	field to one but do not enforce this limit, which allows an SMB client
+	to establish more virtual circuits than allowed by this value ... but
+	other server implementations can enforce this limit." */
+	if (max_vcs < 2)
+		max_vcs = 0xFFFF;
+
+	write_lock(&cifs_tcp_ses_lock);
+	if ((ses->need_reconnect) && is_first_ses_reconnect(ses))
+			goto get_vc_num_exit;  /* vcnum will be zero */
+	for (i = ses->server->srv_count - 1; i < max_vcs; i++) {
+		if (i == 0) /* this is the only connection, use vc 0 */
+			break;
+
+		free_vc_found = 1;
+
+		list_for_each(tmp, &ses->server->smb_ses_list) {
+			tmp_ses = list_entry(tmp, struct cifsSesInfo,
+					     smb_ses_list);
+			if (tmp_ses->vcnum == i) {
+				free_vc_found = 0;
+				break; /* found duplicate, try next vcnum */
+			}
+		}
+		if (free_vc_found)
+			break; /* we found a vcnumber that will work - use it */
+	}
+
+	if (i == 0)
+		vcnum = 0; /* for most common case, ie if one smb session, use
+			      vc zero.  Also for case when no free vcnum, zero
+			      is safest to send (some clients only send zero) */
+	else if (free_vc_found == 0)
+		vcnum = 1;  /* we can not reuse vc=0 safely, since some servers
+				reset all uids on that, but 1 is ok. */
+	else
+		vcnum = i;
+	ses->vcnum = vcnum;
+get_vc_num_exit:
+	write_unlock(&cifs_tcp_ses_lock);
+
+	return le16_to_cpu(vcnum);
+}
+
 static __u32 cifs_ssetup_hdr(struct cifsSesInfo *ses, SESSION_SETUP_ANDX *pSMB)
 {
 	__u32 capabilities = 0;
 
 	/* init fields common to all four types of SessSetup */
-	/* note that header is initialized to zero in header_assemble */
+	/* Note that offsets for first seven fields in req struct are same  */
+	/*	in CIFS Specs so does not matter which of 3 forms of struct */
+	/*	that we use in next few lines                               */
+	/* Note that header is initialized to zero in header_assemble */
 	pSMB->req.AndXCommand = 0xFF;
 	pSMB->req.MaxBufferSize = cpu_to_le16(ses->server->maxBuf);
 	pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);
+	pSMB->req.VcNumber = get_next_vcnum(ses);
 
 	/* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */
 
@@ -71,7 +155,6 @@ static __u32 cifs_ssetup_hdr(struct cifsSesInfo *ses, SESSION_SETUP_ANDX *pSMB)
 	if (ses->capabilities & CAP_UNIX)
 		capabilities |= CAP_UNIX;
 
-	/* BB check whether to init vcnum BB */
 	return capabilities;
 }
 
@@ -228,7 +311,7 @@ static int decode_unicode_ssetup(char **pbcc_area, int bleft,
 
 	kfree(ses->serverOS);
 	/* UTF-8 string will not grow more than four times as big as UCS-16 */
-	ses->serverOS = kzalloc(4 * len, GFP_KERNEL);
+	ses->serverOS = kzalloc((4 * len) + 2 /* trailing null */, GFP_KERNEL);
 	if (ses->serverOS != NULL)
 		cifs_strfromUCS_le(ses->serverOS, (__le16 *)data, len, nls_cp);
 	data += 2 * (len + 1);
@@ -241,7 +324,7 @@ static int decode_unicode_ssetup(char **pbcc_area, int bleft,
 		return rc;
 
 	kfree(ses->serverNOS);
-	ses->serverNOS = kzalloc(4 * len, GFP_KERNEL); /* BB this is wrong length FIXME BB */
+	ses->serverNOS = kzalloc((4 * len) + 2 /* trailing null */, GFP_KERNEL);
 	if (ses->serverNOS != NULL) {
 		cifs_strfromUCS_le(ses->serverNOS, (__le16 *)data, len,
 				   nls_cp);