[PATCH] rename get_lease to break_lease

Al pointed out that the current name of get_lease is extremely confusing
and I agree.

This (a) renames it to break_lease and (b) fixes a bug noticed by Dave
Hansen which could cause a NULL pointer dereference under high load.

fs/locks.c

@@ -994,16 +994,16 @@ static void time_out_leases(struct inode *inode)
 }
 
 /**
- *	__get_lease	-	revoke all outstanding leases on file
+ *	__break_lease	-	revoke all outstanding leases on file
  *	@inode: the inode of the file to return
  *	@mode: the open mode (read or write)
  *
- *	get_lease (inlined for speed) has checked there already
+ *	break_lease (inlined for speed) has checked there already
  *	is a lease on this file.  Leases are broken on a call to open()
  *	or truncate().  This function can sleep unless you
  *	specified %O_NONBLOCK to your open().
  */
-int __get_lease(struct inode *inode, unsigned int mode)
+int __break_lease(struct inode *inode, unsigned int mode)
 {
 	int error = 0, future;
 	struct file_lock *new_fl, *flock;

fs/namei.c

@@ -1183,7 +1183,7 @@ int may_open(struct nameidata *nd, int acc_mode, int flag)
 	/*
 	 * Ensure there are no outstanding leases on the file.
 	 */
-	error = get_lease(inode, flag);
+	error = break_lease(inode, flag);
 	if (error)
 		return error;
 

fs/nfsd/vfs.c

@@ -259,7 +259,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
 		 * If we are changing the size of the file, then
 		 * we need to break all leases.
 		 */
-		err = get_lease(inode, FMODE_WRITE);
+		err = break_lease(inode, FMODE_WRITE);
 		if (err)
 			goto out_nfserr;
 
@@ -453,7 +453,7 @@ nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
 	 * Check to see if there are any leases on this file.
 	 * This may block while leases are broken.
 	 */
-	err = get_lease(inode, (access & MAY_WRITE) ? FMODE_WRITE : 0);
+	err = break_lease(inode, (access & MAY_WRITE) ? FMODE_WRITE : 0);
 	if (err)
 		goto out_nfserr;
 

fs/open.c

@@ -131,7 +131,7 @@ static inline long do_sys_truncate(const char * path, loff_t length)
 	/*
 	 * Make sure that there are no leases.
 	 */
-	error = get_lease(inode, FMODE_WRITE);
+	error = break_lease(inode, FMODE_WRITE);
 	if (error)
 		goto dput_and_out;
 

include/linux/fs.h

@@ -578,7 +578,7 @@ extern int posix_lock_file(struct file *, struct file_lock *);
 extern void posix_block_lock(struct file_lock *, struct file_lock *);
 extern void posix_unblock_lock(struct file *, struct file_lock *);
 extern int posix_locks_deadlock(struct file_lock *, struct file_lock *);
-extern int __get_lease(struct inode *inode, unsigned int flags);
+extern int __break_lease(struct inode *inode, unsigned int flags);
 extern void lease_get_mtime(struct inode *, struct timespec *time);
 extern int lock_may_read(struct inode *, loff_t start, unsigned long count);
 extern int lock_may_write(struct inode *, loff_t start, unsigned long count);
@@ -1052,10 +1052,10 @@ static inline int locks_verify_truncate(struct inode *inode,
 	return 0;
 }
 
-static inline int get_lease(struct inode *inode, unsigned int mode)
+static inline int break_lease(struct inode *inode, unsigned int mode)
 {
-	if (inode->i_flock && (inode->i_flock->fl_flags & FL_LEASE))
-		return __get_lease(inode, mode);
+	if (inode->i_flock)
+		return __break_lease(inode, mode);
 	return 0;
 }
 

kernel/ksyms.c

@@ -287,7 +287,7 @@ EXPORT_SYMBOL(page_follow_link);
 EXPORT_SYMBOL(page_symlink_inode_operations);
 EXPORT_SYMBOL(page_symlink);
 EXPORT_SYMBOL(vfs_readdir);
-EXPORT_SYMBOL(__get_lease);
+EXPORT_SYMBOL(__break_lease);
 EXPORT_SYMBOL(lease_get_mtime);
 EXPORT_SYMBOL(lock_may_read);
 EXPORT_SYMBOL(lock_may_write);