fifos: delegate unhandled kqueue filters to underlying filesystem

This gives the vfs layer a chance to provide handling for EVFILT_VNODE,
for instance.  Change pipe_specops to use the default vop_kqfilter to
accommodate fifoops that don't specify the method (i.e. all in-tree).

Based on a patch by Jan Kokemüller.

PR:		225934
Reviewed by:	kib, markj (both pre-KASSERT)
Differential Revision:	https://reviews.freebsd.org/D32271

2 files changed, 61 insertions, 0 deletions

diff --git a/tests/sys/kqueue/libkqueue/common.h b/tests/sys/kqueue/libkqueue/common.h
index d621a8bf1e00..a92e544910ba 100644
--- a/tests/sys/kqueue/libkqueue/common.h
+++ b/tests/sys/kqueue/libkqueue/common.h
@@ -36,6 +36,8 @@
 #include <stdint.h>
 #include <sys/socket.h>
 #include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
 #include <unistd.h>
 
 #include <sys/event.h>
diff --git a/tests/sys/kqueue/libkqueue/vnode.c b/tests/sys/kqueue/libkqueue/vnode.c
index 8f4311e90745..b6c0915b2654 100644
--- a/tests/sys/kqueue/libkqueue/vnode.c
+++ b/tests/sys/kqueue/libkqueue/vnode.c
@@ -65,6 +65,64 @@ test_kevent_vnode_note_delete(void)
 }
 
 static void
+test_kevent_vnode_note_delete_fifo(void)
+{
+    const char *test_id = "kevent(EVFILT_VNODE, NOTE_DELETE, FIFO)";
+    const char *fifo_path = "./kqueue-fifo.tmp";
+    struct kevent kev;
+    int fd;
+    pid_t pid;
+
+    test_begin(test_id);
+
+    if (mkfifo(fifo_path, 0600) != 0)
+        err(1, "mkfifo");
+
+    pid = fork();
+    if (pid == -1)
+        err(1, "fork");
+
+    if (pid == 0) {
+        char buf[4];
+
+        fd = open(fifo_path, O_RDONLY);
+        if (fd == -1)
+            _exit(1);
+
+        while (read(fd, buf, sizeof(buf)) != 0) {
+        }
+
+        _exit(0);
+    }
+
+    sleep(1);
+    if (waitpid(pid, NULL, WNOHANG) == pid) {
+        unlink(fifo_path);
+        err(1, "open");
+    }
+
+    fd = open(fifo_path, O_WRONLY);
+    if (fd < 0) {
+        unlink(fifo_path);
+        err(1, "open");
+    }
+
+    EV_SET(&kev, fd, EVFILT_VNODE, EV_ADD | EV_ONESHOT, NOTE_DELETE, 0, NULL);
+    if (kevent(kqfd, &kev, 1, NULL, 0, NULL) < 0) {
+        unlink(fifo_path);
+        err(1, "%s", test_id);
+    }
+
+    if (unlink(fifo_path) < 0)
+        err(1, "unlink");
+
+    kevent_cmp(&kev, kevent_get(kqfd));
+    close(fd);
+
+    success();
+}
+
+static void
 test_kevent_vnode_note_write(void)
 {
     const char *test_id = "kevent(EVFILT_VNODE, NOTE_WRITE)";
@@ -261,5 +319,6 @@ test_evfilt_vnode(void)
     test_kevent_vnode_note_attrib();
     test_kevent_vnode_note_rename();
     test_kevent_vnode_note_delete();
+    test_kevent_vnode_note_delete_fifo();
     close(kqfd);
 }