[PATCH RFC v15 01/11] fs/lock: add helper locks_any_blockers to check for blockers

[Dai Ngo <dai.ngo@oracle.com>]

Add helper locks_any_blockers to check if there is any blockers
for a file_lock.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
---
 include/linux/fs.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 831b20430d6e..7f5756bfcc13 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1200,6 +1200,11 @@ extern void lease_unregister_notifier(struct notifier_block *);
 struct files_struct;
 extern void show_fd_locks(struct seq_file *f,
 			 struct file *filp, struct files_struct *files);
+
+static inline bool locks_has_blockers_locked(struct file_lock *lck)
+{
+	return !list_empty(&lck->fl_blocked_requests);
+}
 #else /* !CONFIG_FILE_LOCKING */
 static inline int fcntl_getlk(struct file *file, unsigned int cmd,
 			      struct flock __user *user)
@@ -1335,6 +1340,11 @@ static inline int lease_modify(struct file_lock *fl, int arg,
 struct files_struct;
 static inline void show_fd_locks(struct seq_file *f,
 			struct file *filp, struct files_struct *files) {}
+
+static inline bool locks_has_blockers_locked(struct file_lock *lck)
+{
+	return false;
+}
 #endif /* !CONFIG_FILE_LOCKING */
 
 static inline struct inode *file_inode(const struct file *f)
-- 
2.9.5