# \[PATCH v6 04/21\] fsnotify: Reserve mark flag bits for backends

- From: Gabriel Krisman Bertazi \<hidden\>
- Date: 2021-08-12 21:40:46 
- List: linux-ext4
- Page: https://ratatoskr.run/linux-ext4/2021/08/212286
- Thread: https://ratatoskr.run/linux-api/2021/08/212282/t.md

```text
Split out the final bits of struct fsnotify_mark->flags for use by a
backend.

Signed-off-by: Gabriel Krisman Bertazi <redacted>

Changes since v1:
  - turn consts into defines (jan)
---
 include/linux/fsnotify_backend.h | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 1ce66748a2d2..ae1bd9f06808 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -363,6 +363,20 @@ struct fsnotify_mark_connector {
 	struct hlist_head list;
 };
 
+enum fsnotify_mark_bits {
+	FSN_MARK_FL_BIT_IGNORED_SURV_MODIFY,
+	FSN_MARK_FL_BIT_ALIVE,
+	FSN_MARK_FL_BIT_ATTACHED,
+	FSN_MARK_PRIVATE_FLAGS,
+};
+
+#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY \
+	(1 << FSN_MARK_FL_BIT_IGNORED_SURV_MODIFY)
+#define FSNOTIFY_MARK_FLAG_ALIVE \
+	(1 << FSN_MARK_FL_BIT_ALIVE)
+#define FSNOTIFY_MARK_FLAG_ATTACHED \
+	(1 << FSN_MARK_FL_BIT_ATTACHED)
+
 /*
  * A mark is simply an object attached to an in core inode which allows an
  * fsnotify listener to indicate they are either no longer interested in events
@@ -398,9 +412,7 @@ struct fsnotify_mark {
 	struct fsnotify_mark_connector *connector;
 	/* Events types to ignore [mark->lock, group->mark_mutex] */
 	__u32 ignored_mask;
-#define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY	0x01
-#define FSNOTIFY_MARK_FLAG_ALIVE		0x02
-#define FSNOTIFY_MARK_FLAG_ATTACHED		0x04
+	/* Upper bits [31:PRIVATE_FLAGS] are reserved for backend usage */
 	unsigned int flags;		/* flags [mark->lock] */
 };
 
-- 
2.32.0

```