fsnotify: correctly handle return codes from listeners
Eric Paris [Thu, 28 Oct 2010 21:21:56 +0000 (17:21 -0400)]
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
include/linux/fsnotify_backend.h

index 4498a20..57ecadd 100644 (file)
@@ -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
index 8253295..0268921 100644 (file)
@@ -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 | \