diff mbox

[RFC,3/7] fanotify: new init flag FAN_EVENT_INFO_PARENT

Message ID 1476126784-12520-4-git-send-email-amir73il@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Amir Goldstein Oct. 10, 2016, 7:13 p.m. UTC 
The new init flag FAN_EVENT_INFO_PARENT indicates that the
event fd may point to the parent, depending on the event.

FAN_EVENT_INFO_PARENT will also be used to add support for more
events, so it is stored in a new 'flags' field in the group's
private data for future use.

FAN_EVENT_INFO_PARENT can only be set along with the default
notification class.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
 fs/notify/fanotify/fanotify_user.c | 11 ++++++++++-
 include/linux/fsnotify_backend.h   |  3 ++-
 include/uapi/linux/fanotify.h      |  9 +++++++--
 3 files changed, 19 insertions(+), 4 deletions(-)
diff mbox

Patch

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 8e8e6bc..5f038f4 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -710,6 +710,14 @@  SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 	if (event_f_flags & ~FANOTIFY_INIT_ALL_EVENT_F_BITS)
 		return -EINVAL;
 
+	/*
+	 * New event format info bits can only be set for the default
+	 * notification class
+	 */
+	if ((flags & FAN_ALL_EVENT_INFO_BITS) &&
+	    (flags & FAN_ALL_CLASS_BITS) != FAN_CLASS_NOTIF)
+		return -EINVAL;
+
 	switch (event_f_flags & O_ACCMODE) {
 	case O_RDONLY:
 	case O_RDWR:
@@ -794,6 +802,7 @@  SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 	if (fd < 0)
 		goto out_destroy_group;
 
+	group->fanotify_data.flags = flags;
 	return fd;
 
 out_destroy_group:
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 3830d5a..5722e4f 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -181,7 +181,8 @@  struct fsnotify_group {
 			wait_queue_head_t access_waitq;
 			atomic_t bypass_perm;
 #endif /* CONFIG_FANOTIFY_ACCESS_PERMISSIONS */
-			int f_flags;
+			int flags;           /* flags from fanotify_init() */
+			int f_flags; /* event_f_flags from fanotify_init() */
 			unsigned int max_marks;
 			struct user_struct *user;
 		} fanotify_data;
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 030508d..8e58765 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -36,9 +36,14 @@ 
 #define FAN_UNLIMITED_QUEUE	0x00000010
 #define FAN_UNLIMITED_MARKS	0x00000020
 
+/* These bits determine the format of the reported events */
+#define FAN_EVENT_INFO_PARENT	0x00000100	/* Event fd maybe of parent */
+#define FAN_ALL_EVENT_INFO_BITS (FAN_EVENT_INFO_PARENT)
+
 #define FAN_ALL_INIT_FLAGS	(FAN_CLOEXEC | FAN_NONBLOCK | \
-				 FAN_ALL_CLASS_BITS | FAN_UNLIMITED_QUEUE |\
-				 FAN_UNLIMITED_MARKS)
+				 FAN_ALL_CLASS_BITS | \
+				 FAN_ALL_EVENT_INFO_BITS | \
+				 FAN_UNLIMITED_QUEUE | FAN_UNLIMITED_MARKS)
 
 /* flags used for fanotify_modify_mark() */
 #define FAN_MARK_ADD		0x00000001