5 files changed, 24 insertions, 17 deletions

diff --git a/fs/locks.c b/fs/locks.c
index 43dbc7f566fa..9a3fe0d8285b 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1119,7 +1119,7 @@ int locks_mandatory_area(int read_write, struct inode *inode,
                          * If we've been sleeping someone might have
                          * changed the permissions behind our back.
                          */
-                        if ((inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
+                        if (__mandatory_lock(inode))
                                 continue;
                 }
 
@@ -1761,9 +1761,7 @@ int fcntl_setlk(unsigned int fd, struct file *filp, unsigned int cmd,
         /* Don't allow mandatory locks on files that may be memory mapped
          * and shared.
          */
-        if (IS_MANDLOCK(inode) &&
-            (inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
-            mapping_writably_mapped(filp->f_mapping)) {
+        if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
                 error = -EAGAIN;
                 goto out;
         }
@@ -1887,9 +1885,7 @@ int fcntl_setlk64(unsigned int fd, struct file *filp, unsigned int cmd,
         /* Don't allow mandatory locks on files that may be memory mapped
          * and shared.
          */
-        if (IS_MANDLOCK(inode) &&
-            (inode->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID &&
-            mapping_writably_mapped(filp->f_mapping)) {
+        if (mandatory_lock(inode) && mapping_writably_mapped(filp->f_mapping)) {
                 error = -EAGAIN;
                 goto out;
         }
@@ -2083,9 +2079,7 @@ static void lock_get_status(char* out, struct file_lock *fl, int id, char *pfx)
                 out += sprintf(out, "%6s %s ",
                              (fl->fl_flags & FL_ACCESS) ? "ACCESS" : "POSIX ",
                              (inode == NULL) ? "*NOINODE*" :
-                             (IS_MANDLOCK(inode) &&
-                              (inode->i_mode & (S_IXGRP | S_ISGID)) == S_ISGID) ?
-                             "MANDATORY" : "ADVISORY ");
+                             mandatory_lock(inode) ? "MANDATORY" : "ADVISORY ");
         } else if (IS_FLOCK(fl)) {
                 if (fl->fl_type & LOCK_MAND) {
                         out += sprintf(out, "FLOCK  MSNFS     ");
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3f559700788f..3c028b9c6e0e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2044,7 +2044,7 @@ static inline int
 io_during_grace_disallowed(struct inode *inode, int flags)
 {
         return nfs4_in_grace() && (flags & (RD_STATE | WR_STATE))
-                && MANDATORY_LOCK(inode);
+                && mandatory_lock(inode);
 }
 
 /*
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 7867151ebb83..9152f87eea18 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -65,7 +65,7 @@
  * locks on them because there is no way to know if the accesser has
  * the lock.
  */
-#define IS_ISMNDLK(i)   (S_ISREG((i)->i_mode) && MANDATORY_LOCK(i))
+#define IS_ISMNDLK(i)   (S_ISREG((i)->i_mode) && mandatory_lock(i))
 
 /*
  * This is a cache of readahead params that help us choose the proper
diff --git a/fs/read_write.c b/fs/read_write.c
index 507ddff48a9a..124693e8d3fa 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -205,7 +205,7 @@ int rw_verify_area(int read_write, struct file *file, loff_t *ppos, size_t count
         if (unlikely((pos < 0) || (loff_t) (pos + count) < 0))
                 goto Einval;
 
-        if (unlikely(inode->i_flock && MANDATORY_LOCK(inode))) {
+        if (unlikely(inode->i_flock && mandatory_lock(inode))) {
                 int retval = locks_mandatory_area(
                         read_write == READ ? FLOCK_VERIFY_READ : FLOCK_VERIFY_WRITE,
                         inode, file, pos, count);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 16421f662a7a..f5075e0e7301 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1369,12 +1369,25 @@ extern int locks_mandatory_area(int, struct inode *, struct file *, loff_t, size
  * Candidates for mandatory locking have the setgid bit set
  * but no group execute bit -  an otherwise meaningless combination.
  */
-#define MANDATORY_LOCK(inode) \
-        (IS_MANDLOCK(inode) && ((inode)->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID)
+
+static inline int __mandatory_lock(struct inode *ino)
+{
+        return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID;
+}
+
+/*
+ * ... and these candidates should be on MS_MANDLOCK mounted fs,
+ * otherwise these will be advisory locks
+ */
+
+static inline int mandatory_lock(struct inode *ino)
+{
+        return IS_MANDLOCK(ino) && __mandatory_lock(ino);
+}
 
 static inline int locks_verify_locked(struct inode *inode)
 {
-        if (MANDATORY_LOCK(inode))
+        if (mandatory_lock(inode))
                 return locks_mandatory_locked(inode);
         return 0;
 }
@@ -1385,7 +1398,7 @@ static inline int locks_verify_truncate(struct inode *inode,
                                     struct file *filp,
                                     loff_t size)
 {
-        if (inode->i_flock && MANDATORY_LOCK(inode))
+        if (inode->i_flock && mandatory_lock(inode))
                 return locks_mandatory_area(
                         FLOCK_VERIFY_WRITE, inode, filp,
                         size < inode->i_size ? size : inode->i_size,