Merge 4.1-rc7 into driver-core-next

We want the fixes in this branch as well for testing and merge
resolution.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

13 files changed, 194 insertions, 74 deletions

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index 430e0348c99e..7dc886c9a78f 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -24,6 +24,7 @@
 #include "cifsfs.h"
 #include "dns_resolve.h"
 #include "cifs_debug.h"
+#include "cifs_unicode.h"
 
 static LIST_HEAD(cifs_dfs_automount_list);
 
@@ -312,7 +313,7 @@ static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
 	xid = get_xid();
 	rc = get_dfs_path(xid, ses, full_path + 1, cifs_sb->local_nls,
 		&num_referrals, &referrals,
-		cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+		cifs_remap(cifs_sb));
 	free_xid(xid);
 
 	cifs_put_tlink(tlink);
diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
index 0303c6793d90..5a53ac6b1e02 100644
--- a/fs/cifs/cifs_unicode.c
+++ b/fs/cifs/cifs_unicode.c
@@ -27,41 +27,6 @@
 #include "cifsglob.h"
 #include "cifs_debug.h"
 
-/*
- * cifs_utf16_bytes - how long will a string be after conversion?
- * @utf16 - pointer to input string
- * @maxbytes - don't go past this many bytes of input string
- * @codepage - destination codepage
- *
- * Walk a utf16le string and return the number of bytes that the string will
- * be after being converted to the given charset, not including any null
- * termination required. Don't walk past maxbytes in the source buffer.
- */
-int
-cifs_utf16_bytes(const __le16 *from, int maxbytes,
-		const struct nls_table *codepage)
-{
-	int i;
-	int charlen, outlen = 0;
-	int maxwords = maxbytes / 2;
-	char tmp[NLS_MAX_CHARSET_SIZE];
-	__u16 ftmp;
-
-	for (i = 0; i < maxwords; i++) {
-		ftmp = get_unaligned_le16(&from[i]);
-		if (ftmp == 0)
-			break;
-
-		charlen = codepage->uni2char(ftmp, tmp, NLS_MAX_CHARSET_SIZE);
-		if (charlen > 0)
-			outlen += charlen;
-		else
-			outlen++;
-	}
-
-	return outlen;
-}
-
 int cifs_remap(struct cifs_sb_info *cifs_sb)
 {
 	int map_type;
@@ -155,10 +120,13 @@ convert_sfm_char(const __u16 src_char, char *target)
  * enough to hold the result of the conversion (at least NLS_MAX_CHARSET_SIZE).
  */
 static int
-cifs_mapchar(char *target, const __u16 src_char, const struct nls_table *cp,
+cifs_mapchar(char *target, const __u16 *from, const struct nls_table *cp,
 	     int maptype)
 {
 	int len = 1;
+	__u16 src_char;
+
+	src_char = *from;
 
 	if ((maptype == SFM_MAP_UNI_RSVD) && convert_sfm_char(src_char, target))
 		return len;
@@ -168,10 +136,23 @@ cifs_mapchar(char *target, const __u16 src_char, const struct nls_table *cp,
 
 	/* if character not one of seven in special remap set */
 	len = cp->uni2char(src_char, target, NLS_MAX_CHARSET_SIZE);
-	if (len <= 0) {
-		*target = '?';
-		len = 1;
-	}
+	if (len <= 0)
+		goto surrogate_pair;
+
+	return len;
+
+surrogate_pair:
+	/* convert SURROGATE_PAIR and IVS */
+	if (strcmp(cp->charset, "utf8"))
+		goto unknown;
+	len = utf16s_to_utf8s(from, 3, UTF16_LITTLE_ENDIAN, target, 6);
+	if (len <= 0)
+		goto unknown;
+	return len;
+
+unknown:
+	*target = '?';
+	len = 1;
 	return len;
 }
 
@@ -206,7 +187,7 @@ cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen,
 	int nullsize = nls_nullsize(codepage);
 	int fromwords = fromlen / 2;
 	char tmp[NLS_MAX_CHARSET_SIZE];
-	__u16 ftmp;
+	__u16 ftmp[3];		/* ftmp[3] = 3array x 2bytes = 6bytes UTF-16 */
 
 	/*
 	 * because the chars can be of varying widths, we need to take care
@@ -217,9 +198,17 @@ cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen,
 	safelen = tolen - (NLS_MAX_CHARSET_SIZE + nullsize);
 
 	for (i = 0; i < fromwords; i++) {
-		ftmp = get_unaligned_le16(&from[i]);
-		if (ftmp == 0)
+		ftmp[0] = get_unaligned_le16(&from[i]);
+		if (ftmp[0] == 0)
 			break;
+		if (i + 1 < fromwords)
+			ftmp[1] = get_unaligned_le16(&from[i + 1]);
+		else
+			ftmp[1] = 0;
+		if (i + 2 < fromwords)
+			ftmp[2] = get_unaligned_le16(&from[i + 2]);
+		else
+			ftmp[2] = 0;
 
 		/*
 		 * check to see if converting this character might make the
@@ -234,6 +223,17 @@ cifs_from_utf16(char *to, const __le16 *from, int tolen, int fromlen,
 		/* put converted char into 'to' buffer */
 		charlen = cifs_mapchar(&to[outlen], ftmp, codepage, map_type);
 		outlen += charlen;
+
+		/* charlen (=bytes of UTF-8 for 1 character)
+		 * 4bytes UTF-8(surrogate pair) is charlen=4
+		 *   (4bytes UTF-16 code)
+		 * 7-8bytes UTF-8(IVS) is charlen=3+4 or 4+4
+		 *   (2 UTF-8 pairs divided to 2 UTF-16 pairs) */
+		if (charlen == 4)
+			i++;
+		else if (charlen >= 5)
+			/* 5-6bytes UTF-8 */
+			i += 2;
 	}
 
 	/* properly null-terminate string */
@@ -296,6 +296,46 @@ success:
 }
 
 /*
+ * cifs_utf16_bytes - how long will a string be after conversion?
+ * @utf16 - pointer to input string
+ * @maxbytes - don't go past this many bytes of input string
+ * @codepage - destination codepage
+ *
+ * Walk a utf16le string and return the number of bytes that the string will
+ * be after being converted to the given charset, not including any null
+ * termination required. Don't walk past maxbytes in the source buffer.
+ */
+int
+cifs_utf16_bytes(const __le16 *from, int maxbytes,
+		const struct nls_table *codepage)
+{
+	int i;
+	int charlen, outlen = 0;
+	int maxwords = maxbytes / 2;
+	char tmp[NLS_MAX_CHARSET_SIZE];
+	__u16 ftmp[3];
+
+	for (i = 0; i < maxwords; i++) {
+		ftmp[0] = get_unaligned_le16(&from[i]);
+		if (ftmp[0] == 0)
+			break;
+		if (i + 1 < maxwords)
+			ftmp[1] = get_unaligned_le16(&from[i + 1]);
+		else
+			ftmp[1] = 0;
+		if (i + 2 < maxwords)
+			ftmp[2] = get_unaligned_le16(&from[i + 2]);
+		else
+			ftmp[2] = 0;
+
+		charlen = cifs_mapchar(tmp, ftmp, codepage, NO_MAP_UNI_RSVD);
+		outlen += charlen;
+	}
+
+	return outlen;
+}
+
+/*
  * cifs_strndup_from_utf16 - copy a string from wire format to the local
  * codepage
  * @src - source string
@@ -409,10 +449,15 @@ cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
 	char src_char;
 	__le16 dst_char;
 	wchar_t tmp;
+	wchar_t *wchar_to;	/* UTF-16 */
+	int ret;
+	unicode_t u;
 
 	if (map_chars == NO_MAP_UNI_RSVD)
 		return cifs_strtoUTF16(target, source, PATH_MAX, cp);
 
+	wchar_to = kzalloc(6, GFP_KERNEL);
+
 	for (i = 0; i < srclen; j++) {
 		src_char = source[i];
 		charlen = 1;
@@ -441,11 +486,55 @@ cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
 			 * if no match, use question mark, which at least in
 			 * some cases serves as wild card
 			 */
-			if (charlen < 1) {
-				dst_char = cpu_to_le16(0x003f);
-				charlen = 1;
+			if (charlen > 0)
+				goto ctoUTF16;
+
+			/* convert SURROGATE_PAIR */
+			if (strcmp(cp->charset, "utf8") || !wchar_to)
+				goto unknown;
+			if (*(source + i) & 0x80) {
+				charlen = utf8_to_utf32(source + i, 6, &u);
+				if (charlen < 0)
+					goto unknown;
+			} else
+				goto unknown;
+			ret  = utf8s_to_utf16s(source + i, charlen,
+					       UTF16_LITTLE_ENDIAN,
+					       wchar_to, 6);
+			if (ret < 0)
+				goto unknown;
+
+			i += charlen;
+			dst_char = cpu_to_le16(*wchar_to);
+			if (charlen <= 3)
+				/* 1-3bytes UTF-8 to 2bytes UTF-16 */
+				put_unaligned(dst_char, &target[j]);
+			else if (charlen == 4) {
+				/* 4bytes UTF-8(surrogate pair) to 4bytes UTF-16
+				 * 7-8bytes UTF-8(IVS) divided to 2 UTF-16
+				 *   (charlen=3+4 or 4+4) */
+				put_unaligned(dst_char, &target[j]);
+				dst_char = cpu_to_le16(*(wchar_to + 1));
+				j++;
+				put_unaligned(dst_char, &target[j]);
+			} else if (charlen >= 5) {
+				/* 5-6bytes UTF-8 to 6bytes UTF-16 */
+				put_unaligned(dst_char, &target[j]);
+				dst_char = cpu_to_le16(*(wchar_to + 1));
+				j++;
+				put_unaligned(dst_char, &target[j]);
+				dst_char = cpu_to_le16(*(wchar_to + 2));
+				j++;
+				put_unaligned(dst_char, &target[j]);
 			}
+			continue;
+
+unknown:
+			dst_char = cpu_to_le16(0x003f);
+			charlen = 1;
 		}
+
+ctoUTF16:
 		/*
 		 * character may take more than one byte in the source string,
 		 * but will take exactly two bytes in the target string
@@ -456,6 +545,7 @@ cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
 
 ctoUTF16_out:
 	put_unaligned(0, &target[j]); /* Null terminate target unicode string */
+	kfree(wchar_to);
 	return j;
 }
 
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index f5089bde3635..0a9fb6b53126 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -469,6 +469,8 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
 		seq_puts(s, ",nouser_xattr");
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
 		seq_puts(s, ",mapchars");
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
+		seq_puts(s, ",mapposix");
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL)
 		seq_puts(s, ",sfu");
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_BRL)
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index c31ce98c1704..c63fd1dde25b 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -361,11 +361,11 @@ extern int CIFSUnixCreateHardLink(const unsigned int xid,
 extern int CIFSUnixCreateSymLink(const unsigned int xid,
 			struct cifs_tcon *tcon,
 			const char *fromName, const char *toName,
-			const struct nls_table *nls_codepage);
+			const struct nls_table *nls_codepage, int remap);
 extern int CIFSSMBUnixQuerySymLink(const unsigned int xid,
 			struct cifs_tcon *tcon,
 			const unsigned char *searchName, char **syminfo,
-			const struct nls_table *nls_codepage);
+			const struct nls_table *nls_codepage, int remap);
 extern int CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
 			       __u16 fid, char **symlinkinfo,
 			       const struct nls_table *nls_codepage);
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 84650a51c7c4..f26ffbfc64d8 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2784,7 +2784,7 @@ copyRetry:
 int
 CIFSUnixCreateSymLink(const unsigned int xid, struct cifs_tcon *tcon,
 		      const char *fromName, const char *toName,
-		      const struct nls_table *nls_codepage)
+		      const struct nls_table *nls_codepage, int remap)
 {
 	TRANSACTION2_SPI_REQ *pSMB = NULL;
 	TRANSACTION2_SPI_RSP *pSMBr = NULL;
@@ -2804,9 +2804,9 @@ createSymLinkRetry:
 
 	if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
 		name_len =
-		    cifs_strtoUTF16((__le16 *) pSMB->FileName, fromName,
-				    /* find define for this maxpathcomponent */
-				    PATH_MAX, nls_codepage);
+		    cifsConvertToUTF16((__le16 *) pSMB->FileName, fromName,
+				/* find define for this maxpathcomponent */
+					PATH_MAX, nls_codepage, remap);
 		name_len++;	/* trailing null */
 		name_len *= 2;
 
@@ -2828,9 +2828,9 @@ createSymLinkRetry:
 	data_offset = (char *) (&pSMB->hdr.Protocol) + offset;
 	if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
 		name_len_target =
-		    cifs_strtoUTF16((__le16 *) data_offset, toName, PATH_MAX
-				    /* find define for this maxpathcomponent */
-				    , nls_codepage);
+		    cifsConvertToUTF16((__le16 *) data_offset, toName,
+				/* find define for this maxpathcomponent */
+					PATH_MAX, nls_codepage, remap);
 		name_len_target++;	/* trailing null */
 		name_len_target *= 2;
 	} else {	/* BB improve the check for buffer overruns BB */
@@ -3034,7 +3034,7 @@ winCreateHardLinkRetry:
 int
 CIFSSMBUnixQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
 			const unsigned char *searchName, char **symlinkinfo,
-			const struct nls_table *nls_codepage)
+			const struct nls_table *nls_codepage, int remap)
 {
 /* SMB_QUERY_FILE_UNIX_LINK */
 	TRANSACTION2_QPI_REQ *pSMB = NULL;
@@ -3055,8 +3055,9 @@ querySymLinkRetry:
 
 	if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) {
 		name_len =
-			cifs_strtoUTF16((__le16 *) pSMB->FileName, searchName,
-					PATH_MAX, nls_codepage);
+			cifsConvertToUTF16((__le16 *) pSMB->FileName,
+					   searchName, PATH_MAX, nls_codepage,
+					   remap);
 		name_len++;	/* trailing null */
 		name_len *= 2;
 	} else {	/* BB improve the check for buffer overruns BB */
@@ -4917,7 +4918,7 @@ getDFSRetry:
 		strncpy(pSMB->RequestFileName, search_name, name_len);
 	}
 
-	if (ses->server && ses->server->sign)
+	if (ses->server->sign)
 		pSMB->hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 
 	pSMB->hdr.Uid = ses->Suid;
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index f3bfe08e177b..8383d5ea4202 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -386,6 +386,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
 		rc = generic_ip_connect(server);
 		if (rc) {
 			cifs_dbg(FYI, "reconnect error %d\n", rc);
+			mutex_unlock(&server->srv_mutex);
 			msleep(3000);
 		} else {
 			atomic_inc(&tcpSesReconnectCount);
@@ -393,8 +394,8 @@ cifs_reconnect(struct TCP_Server_Info *server)
 			if (server->tcpStatus != CifsExiting)
 				server->tcpStatus = CifsNeedNegotiate;
 			spin_unlock(&GlobalMid_Lock);
+			mutex_unlock(&server->srv_mutex);
 		}
-		mutex_unlock(&server->srv_mutex);
 	} while (server->tcpStatus == CifsNeedReconnect);
 
 	return rc;
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 338d56936f6a..c3eb998a99bd 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -620,8 +620,7 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
 		}
 		rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
 					    cifs_sb->local_nls,
-					    cifs_sb->mnt_cifs_flags &
-						CIFS_MOUNT_MAP_SPECIAL_CHR);
+					    cifs_remap(cifs_sb));
 		if (rc)
 			goto mknod_out;
 
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index cafbf10521d5..3f50cee79df9 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -140,8 +140,7 @@ int cifs_posix_open(char *full_path, struct inode **pinode,
 	posix_flags = cifs_posix_convert_flags(f_flags);
 	rc = CIFSPOSIXCreate(xid, tcon, posix_flags, mode, pnetfid, presp_data,
 			     poplock, full_path, cifs_sb->local_nls,
-			     cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+			     cifs_remap(cifs_sb));
 	cifs_put_tlink(tlink);
 
 	if (rc)
@@ -1553,8 +1552,8 @@ cifs_setlk(struct file *file, struct file_lock *flock, __u32 type,
 		rc = server->ops->mand_unlock_range(cfile, flock, xid);
 
 out:
-	if (flock->fl_flags & FL_POSIX)
-		posix_lock_file_wait(file, flock);
+	if (flock->fl_flags & FL_POSIX && !rc)
+		rc = posix_lock_file_wait(file, flock);
 	return rc;
 }
 
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 55b58112d122..f621b44cb800 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -373,8 +373,7 @@ int cifs_get_inode_info_unix(struct inode **pinode,
 
 	/* could have done a find first instead but this returns more info */
 	rc = CIFSSMBUnixQPathInfo(xid, tcon, full_path, &find_data,
-				  cifs_sb->local_nls, cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				  cifs_sb->local_nls, cifs_remap(cifs_sb));
 	cifs_put_tlink(tlink);
 
 	if (!rc) {
@@ -402,9 +401,25 @@ int cifs_get_inode_info_unix(struct inode **pinode,
 			rc = -ENOMEM;
 	} else {
 		/* we already have inode, update it */
+
+		/* if uniqueid is different, return error */
+		if (unlikely(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM &&
+		    CIFS_I(*pinode)->uniqueid != fattr.cf_uniqueid)) {
+			rc = -ESTALE;
+			goto cgiiu_exit;
+		}
+
+		/* if filetype is different, return error */
+		if (unlikely(((*pinode)->i_mode & S_IFMT) !=
+		    (fattr.cf_mode & S_IFMT))) {
+			rc = -ESTALE;
+			goto cgiiu_exit;
+		}
+
 		cifs_fattr_to_inode(*pinode, &fattr);
 	}
 
+cgiiu_exit:
 	return rc;
 }
 
@@ -839,6 +854,15 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
 		if (!*inode)
 			rc = -ENOMEM;
 	} else {
+		/* we already have inode, update it */
+
+		/* if filetype is different, return error */
+		if (unlikely(((*inode)->i_mode & S_IFMT) !=
+		    (fattr.cf_mode & S_IFMT))) {
+			rc = -ESTALE;
+			goto cgii_exit;
+		}
+
 		cifs_fattr_to_inode(*inode, &fattr);
 	}
 
@@ -2215,8 +2239,7 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
 		pTcon = tlink_tcon(tlink);
 		rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, args,
 				    cifs_sb->local_nls,
-				    cifs_sb->mnt_cifs_flags &
-					CIFS_MOUNT_MAP_SPECIAL_CHR);
+				    cifs_remap(cifs_sb));
 		cifs_put_tlink(tlink);
 	}
 
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 252e672d5604..e6c707cc62b3 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -717,7 +717,8 @@ cifs_symlink(struct inode *inode, struct dentry *direntry, const char *symname)
 		rc = create_mf_symlink(xid, pTcon, cifs_sb, full_path, symname);
 	else if (pTcon->unix_ext)
 		rc = CIFSUnixCreateSymLink(xid, pTcon, full_path, symname,
-					   cifs_sb->local_nls);
+					   cifs_sb->local_nls,
+					   cifs_remap(cifs_sb));
 	/* else
 	   rc = CIFSCreateReparseSymLink(xid, pTcon, fromName, toName,
 					cifs_sb_target->local_nls); */
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index b4a47237486b..b1eede3678a9 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -90,6 +90,8 @@ cifs_prime_dcache(struct dentry *parent, struct qstr *name,
 	if (dentry) {
 		inode = d_inode(dentry);
 		if (inode) {
+			if (d_mountpoint(dentry))
+				goto out;
 			/*
 			 * If we're generating inode numbers, then we don't
 			 * want to clobber the existing one with the one that
diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c
index 7bfdd6066276..fc537c29044e 100644
--- a/fs/cifs/smb1ops.c
+++ b/fs/cifs/smb1ops.c
@@ -960,7 +960,8 @@ cifs_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 	/* Check for unix extensions */
 	if (cap_unix(tcon->ses)) {
 		rc = CIFSSMBUnixQuerySymLink(xid, tcon, full_path, target_path,
-					     cifs_sb->local_nls);
+					     cifs_sb->local_nls,
+					     cifs_remap(cifs_sb));
 		if (rc == -EREMOTE)
 			rc = cifs_unix_dfs_readlink(xid, tcon, full_path,
 						    target_path,
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 65cd7a84c8bc..54cbe19d9c08 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -110,7 +110,7 @@ smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
 
 	/* GLOBAL_CAP_LARGE_MTU will only be set if dialect > SMB2.02 */
 	/* See sections 2.2.4 and 3.2.4.1.5 of MS-SMB2 */
-	if ((tcon->ses) &&
+	if ((tcon->ses) && (tcon->ses->server) &&
 	    (tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
 		hdr->CreditCharge = cpu_to_le16(1);
 	/* else CreditCharge MBZ */