[PATCH 5.10 159/452] inotify: show inotify mask flags in proc fdinfo

[Greg Kroah-Hartman]

From: Amir Goldstein <amir73il@xxxxxxxxx>

[ Upstream commit a32e697cda27679a0327ae2cafdad8c7170f548f ]

The inotify mask flags IN_ONESHOT and IN_EXCL_UNLINK are not "internal
to kernel" and should be exposed in procfs fdinfo so CRIU can restore
them.

Fixes: 6933599697c9 ("inotify: hide internal kernel bits from fdinfo")
Link: https://lore.kernel.org/r/20220422120327.3459282-2-amir73il@xxxxxxxxx
Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/notify/fdinfo.c               | 11 ++---------
 fs/notify/inotify/inotify.h      | 12 ++++++++++++
 fs/notify/inotify/inotify_user.c |  2 +-
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/fs/notify/fdinfo.c b/fs/notify/fdinfo.c
index f0d6b54be412..765b50aeadd2 100644
--- a/fs/notify/fdinfo.c
+++ b/fs/notify/fdinfo.c
@@ -83,16 +83,9 @@ static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 	inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
 	inode = igrab(fsnotify_conn_inode(mark->connector));
 	if (inode) {
-		/*
-		 * IN_ALL_EVENTS represents all of the mask bits
-		 * that we expose to userspace.  There is at
-		 * least one bit (FS_EVENT_ON_CHILD) which is
-		 * used only internally to the kernel.
-		 */
-		u32 mask = mark->mask & IN_ALL_EVENTS;
-		seq_printf(m, "inotify wd:%x ino:%lx sdev:%x mask:%x ignored_mask:%x ",
+		seq_printf(m, "inotify wd:%x ino:%lx sdev:%x mask:%x ignored_mask:0 ",
 			   inode_mark->wd, inode->i_ino, inode->i_sb->s_dev,
-			   mask, mark->ignored_mask);
+			   inotify_mark_user_mask(mark));
 		show_mark_fhandle(m, inode);
 		seq_putc(m, '\n');
 		iput(inode);
diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h
index 2007e3711916..8f00151eb731 100644
--- a/fs/notify/inotify/inotify.h
+++ b/fs/notify/inotify/inotify.h
@@ -22,6 +22,18 @@ static inline struct inotify_event_info *INOTIFY_E(struct fsnotify_event *fse)
 	return container_of(fse, struct inotify_event_info, fse);
 }
 
+/*
+ * INOTIFY_USER_FLAGS represents all of the mask bits that we expose to
+ * userspace.  There is at least one bit (FS_EVENT_ON_CHILD) which is
+ * used only internally to the kernel.
+ */
+#define INOTIFY_USER_MASK (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK)
+
+static inline __u32 inotify_mark_user_mask(struct fsnotify_mark *fsn_mark)
+{
+	return fsn_mark->mask & INOTIFY_USER_MASK;
+}
+
 extern void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
 					   struct fsnotify_group *group);
 extern int inotify_handle_inode_event(struct fsnotify_mark *inode_mark,
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 5f6c6bf65909..32b6b97021be 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -88,7 +88,7 @@ static inline __u32 inotify_arg_to_mask(struct inode *inode, u32 arg)
 		mask |= FS_EVENT_ON_CHILD;
 
 	/* mask off the flags used to open the fd */
-	mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK));
+	mask |= (arg & INOTIFY_USER_MASK);
 
 	return mask;
 }
-- 
2.35.1