fsnotify: correctly handle return codes from listeners

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>

diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index 4498a208df940b92117323dcad6cb355969fd164..57ecadd85abfb3b43abc872876e26ecc964ff7ce 100644 (file)
--- 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 825329534162613362f07830cd60ba95bd0fd2c9..026892187c8318965df0843bbf9da607ee996e13 100644 (file)
--- 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 | \