Problem Description: do_sendfile in fs/read_write.c does not call fsnotify functions, unlike its neighbors. Manifests as a lack of inotify ACCESS event when a file is sent using sendfile(2).

I am a kernel hacking newbie, but I came up with the following patch, which seems good enough for my purposes. j_eng in #kernel on irc.freenode.net suggests that unnamed sockets shouldn't have the MODIFY event fired, since they can't be watched with inotify anyway.

--- /usr/src/linux-source-2.6.26-1-amd64/fs/read_write.c        2008-07-13 17:51:29.000000000 -0400
+++ linux-source-2.6.26/fs/read_write.c 2009-03-02 22:52:09.000000000 -0500
@@ -778,6 +778,8 @@ static ssize_t do_sendfile(int out_fd, i
        if (retval > 0) {
                add_rchar(current, retval);
                add_wchar(current, retval);
+                fsnotify_access(in_file->f_path.dentry);
+                fsnotify_modify(out_file->f_path.dentry);
        }

        inc_syscr(current);