[PATCH 05/20] fsnotify: correctly handle return codes from listeners

[Eric Paris <eparis@redhat.com>]

When fsnotify groups return errors they are ignored.  For permissions
events these should be passed back up the stack, but for most events these
should continue to be ignored.

Signed-off-by: Eric Paris <eparis@redhat.com>
---

 fs/notify/fsnotify.c             |   20 ++++++++++++--------
 include/linux/fsnotify_backend.h |    2 ++
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 4498a20..57ecadd 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -252,20 +252,23 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
 
 		if (inode_group > vfsmount_group) {
 			/* handle inode */
-			send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
-				      data_is, cookie, file_name, &event);
+			ret = send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
+					    data_is, cookie, file_name, &event);
 			/* we didn't use the vfsmount_mark */
 			vfsmount_group = NULL;
 		} else if (vfsmount_group > inode_group) {
-			send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
-				      data_is, cookie, file_name, &event);
+			ret = send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
+					    data_is, cookie, file_name, &event);
 			inode_group = NULL;
 		} else {
-			send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
-				      mask, data, data_is, cookie, file_name,
-				      &event);
+			ret = send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
+					    mask, data, data_is, cookie, file_name,
+					    &event);
 		}
 
+		if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
+			goto out;
+
 		if (inode_group)
 			inode_node = srcu_dereference(inode_node->next,
 						      &fsnotify_mark_srcu);
@@ -273,7 +276,8 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
 			vfsmount_node = srcu_dereference(vfsmount_node->next,
 							 &fsnotify_mark_srcu);
 	}
-
+	ret = 0;
+out:
 	srcu_read_unlock(&fsnotify_mark_srcu, idx);
 	/*
 	 * fsnotify_create_event() took a reference so the event can't be cleaned
diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 8253295..0268921 100644
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -64,6 +64,8 @@
 
 #define FS_MOVE			(FS_MOVED_FROM | FS_MOVED_TO)
 
+#define ALL_FSNOTIFY_PERM_EVENTS (FS_OPEN_PERM | FS_ACCESS_PERM)
+
 #define ALL_FSNOTIFY_EVENTS (FS_ACCESS | FS_MODIFY | FS_ATTRIB | \
 			     FS_CLOSE_WRITE | FS_CLOSE_NOWRITE | FS_OPEN | \
 			     FS_MOVED_FROM | FS_MOVED_TO | FS_CREATE | \