[PATCH v8 13/19] fanotify: add a helper to check for pre content events

[Josef Bacik <josef@toxicpanda.com>]

From: Amir Goldstein <amir73il@gmail.com>

We want to emit events during page fault, and calling into fanotify
could be expensive, so add a helper to allow us to skip calling into
fanotify from page fault.  This will also be used to disable readahead
for content watched files which will be handled in a subsequent patch.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 include/linux/fsnotify.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h
index 08893429a818..d5a0d8648000 100644
--- a/include/linux/fsnotify.h
+++ b/include/linux/fsnotify.h
@@ -178,6 +178,11 @@ static inline void file_set_fsnotify_mode(struct file *file)
 	}
 }
 
+static inline bool fsnotify_file_has_pre_content_watches(struct file *file)
+{
+	return file && unlikely(FMODE_FSNOTIFY_HSM(file->f_mode));
+}
+
 /*
  * fsnotify_file_area_perm - permission hook before access to file range
  */
@@ -264,6 +269,11 @@ static inline void file_set_fsnotify_mode(struct file *file)
 {
 }
 
+static inline bool fsnotify_file_has_pre_content_watches(struct file *file)
+{
+	return false;
+}
+
 static inline int fsnotify_file_area_perm(struct file *file, int perm_mask,
 					  const loff_t *ppos, size_t count)
 {
-- 
2.43.0