1 files changed, 14 insertions, 0 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index d6a3c1c8a6f8..351942042833 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -89,6 +89,7 @@ struct smb_vol {
         bool nullauth:1;   /* attempt to authenticate with null user */
         bool nocase:1;     /* request case insensitive filenames */
         bool nobrl:1;      /* disable sending byte range locks to srv */
+        bool mand_lock:1;  /* send mandatory not posix byte range lock reqs */
         bool seal:1;       /* request transport encryption on share */
         bool nodfs:1;      /* Do not request DFS, even if available */
         bool local_lease:1; /* check leases only on local system, not remote */
@@ -1246,6 +1247,17 @@ cifs_parse_mount_options(char *options, const char *devname,
                         if (vol->file_mode ==
                                 (S_IALLUGO & ~(S_ISUID | S_IXGRP)))
                                 vol->file_mode = S_IALLUGO;
+                } else if (strnicmp(data, "forcemandatorylock", 9) == 0) {
+                        /* will take the shorter form "forcemand" as well */
+                        /* This mount option will force use of mandatory
+                          (DOS/Windows style) byte range locks, instead of
+                          using posix advisory byte range locks, even if the
+                          Unix extensions are available and posix locks would
+                          be supported otherwise. If Unix extensions are not
+                          negotiated this has no effect since mandatory locks
+                          would be used (mandatory locks is all that those
+                          those servers support) */
+                        vol->mand_lock = 1;
                 } else if (strnicmp(data, "setuids", 7) == 0) {
                         vol->setuids = 1;
                 } else if (strnicmp(data, "nosetuids", 9) == 0) {
@@ -2150,6 +2162,8 @@ static void setup_cifs_sb(struct smb_vol *pvolume_info,
                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_UNX_EMUL;
         if (pvolume_info->nobrl)
                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_BRL;
+        if (pvolume_info->mand_lock)
+                cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NOPOSIXBRL;
         if (pvolume_info->cifs_acl)
                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_CIFS_ACL;
         if (pvolume_info->override_uid)