X More effort to unmount failed wcfs.go

Else after first failing tests all furhter test can't start because
trying to stat testmntpt/.wcfs gives ENOTCONN.

Makefile

@@ -96,8 +96,8 @@ LINKC	= $(LINK.c) $< $(LOADLIBES) $(LDLIBS) -o $@
 # tests without instrumentation
 test.t	: $(TESTS:%=%.trun)
 %.trun	: %.t
-	gdb -q -ex run -ex backtrace -ex quit $(XRUN<)
-	#$(XRUN<)
+	#gdb -q -ex run -ex backtrace -ex quit $(XRUN<)
+	$(XRUN<)
 
 %.t	: %.c $(ccan_config)
 	$(LINKC)

wcfs/__init__.py

@@ -209,7 +209,7 @@ def _start(zurl, *optv):    # -> Conn
         while 1:
             ret = proc.poll()
             if ret is not None:
-                raise "exited with %s" % ret
+                raise RuntimeError("exited with %s" % ret)
 
             _, _rx = select(
                 ctx.done().recv,    # 0

wcfs/wcfs.go

@@ -2389,7 +2389,7 @@ func _main() (err error) {
 	if kinit.Flags & fuse.CAP_EXPLICIT_INVAL_DATA == 0 {
 		w1 := fmt.Sprintf("%s does not support explicit data cache invalidation", kfuse)
 		w2 := "-> performance will be AWFUL."
-		w3 := "-> you need kernel which includes git.kernel.org/linus/ad2ba64dd489 ."
+		w3 := "-> you need kernel which includes git.kernel.org/linus/ad2ba64dd489."
 		log.Error(w1); log.Error(w2); log.Error(w3)
 		fmt.Fprintf(os.Stderr, "W: wcfs: %s\nW: wcfs: %s\nW: wcfs: %s\n", w1, w2, w3)
 	}

wcfs/wcfs_test.py

@@ -36,7 +36,8 @@ from ZODB.utils import z64, u64, p64
 import sys, os, os.path, subprocess, threading, inspect, traceback, re
 from thread import get_ident as gettid
 from time import gmtime
-from errno import EINVAL
+from errno import EINVAL, ENOENT, ENOTCONN
+from stat import S_ISDIR
 from signal import SIGQUIT, SIGKILL
 from golang import go, chan, select, func, defer, default
 from golang import context, sync, time
@@ -87,7 +88,7 @@ def setup_function(f):
 # make sure we unmount wcfs after every test.
 # (tDB checks this in more detail, but join tests don't use tDB)
 def teardown_function(f):
-    mounted = (0 == subprocess.call(["mountpoint", "-q", testmntpt]))
+    mounted = is_mountpoint(testmntpt)
     if mounted:
         subprocess.check_call(["fusermount", "-u", testmntpt])
     if os.path.exists(testmntpt):
@@ -195,12 +196,19 @@ class DFile:
 #
 # XXX print -> t.trace/debug() + t.verbose depending on py.test -v -v ?
 class tDB:
+    @func
     def __init__(t):
         t.root  = testdb.dbopen()
+        def _(): # close/unlock db if __init__ fails
+            exc = sys.exc_info()[1]
+            if exc is not None:
+                dbclose(t.root)
+        defer(_)
+
         assert not os.path.exists(testmntpt)
         t.wc    = wcfs.join(testzurl, autostart=True)
         assert os.path.exists(testmntpt)
-        assert 0 == subprocess.call(["mountpoint", "-q", testmntpt])
+        assert is_mountpoint(testmntpt)
 
         # force-unmount wcfs on timeout to unstuck current test and let it fail.
         # Force-unmount can be done reliably only by writing into
@@ -272,32 +280,33 @@ class tDB:
 
         # unmount and wait for wcfs to exit
         def _():
-            assert 0 != subprocess.call(["mountpoint", "-q", testmntpt])
+            assert not is_mountpoint(testmntpt)
             os.rmdir(testmntpt)
         defer(_)
         def _():
             # kill wcfs.go in case it is deadlocked and does not exit by itself
             if procwait_(timeout(), t.wc._proc):
                 return
-            print("\nC: wcfs.go does not exit")
-            print("-> kill -QUIT wcfs.go ...\n")
+            print("\nC: wcfs.go does not exit", file=sys.stderr)
+            print("-> kill -QUIT wcfs.go ...\n", file=sys.stderr)
             os.kill(t.wc._proc.pid, SIGQUIT)
 
             if procwait_(timeout(), t.wc._proc):
                 return
-            print("\nC: wcfs.go does not exit (after SIGQUIT)")
-            print("-> kill -KILL wcfs.go ...\n")
+            print("\nC: wcfs.go does not exit (after SIGQUIT)", file=sys.stderr)
+            print("-> kill -KILL wcfs.go ...\n", file=sys.stderr)
             os.kill(t.wc._proc.pid, SIGKILL)
 
             if procwait_(timeout(), t.wc._proc):
                 return
-            print("\nC: wcfs.go does not exit (after SIGKILL; probably it is stuck in kernel)")
-            print("-> nothing we can do...\n")  # XXX dump /proc/pid/task/*/stack instead  (ignore EPERM)
+            print("\nC: wcfs.go does not exit (after SIGKILL; probably it is stuck in kernel)", file=sys.stderr)
+            print("-> nothing we can do...\n", file=sys.stderr)  # XXX dump /proc/pid/task/*/stack instead  (ignore EPERM)
             fail("wcfs.go does not exit even after SIGKILL")
         defer(_)
         def _():
-            if not ready(t._wcfuseaborted):
-                assert 0 == subprocess.call(["mountpoint", "-q", testmntpt])
+            #if not ready(t._wcfuseaborted):
+            #    assert 0 == subprocess.call(["mountpoint", "-q", testmntpt])
+            assert is_mountpoint(testmntpt)
             subprocess.check_call(["fusermount", "-u", testmntpt])
         defer(_)
 
@@ -2057,6 +2066,27 @@ def procwait_(ctx, proc):   # -> ok
         raise
     return True
 
+# is_mountpoint returns whether path is a mountpoint
+def is_mountpoint(path):    # -> bool
+    # NOTE we don't call mountpoint directly on path, because if FUSE
+    # fileserver failed, the mountpoint will also fail and print ENOTCONN
+    try:
+        _ = os.lstat(path)
+    except OSError as e:
+        if e.errno == ENOENT:
+            return False
+        # "Transport endpoint is not connected" -> it is a failed FUSE server
+        # (XXX we can also grep /proc/mounts)
+        if e.errno == ENOTCONN:
+            return True
+        raise
+
+    if not S_ISDIR(_.st_mode):
+        return False
+
+    mounted = (0 == subprocess.call(["mountpoint", "-q", path]))
+    return mounted
+
 
 # xdefer is like defer, but makes sure exception raised before deferred
 # function is called is not lost.