PERFORCE change 85342 for review

[soc-chenk]

http://perforce.freebsd.org/chv.cgi?CH=85342

Change 85342 by soc-chenk at soc-chenk_leavemealone on 2005/10/15 15:45:35

	device read converted to use msleep instead of condvar
	[this seems to prevent daemon-segfaults-in-readdir panics]
	Submitted by:	soc-chenk

Affected files ...

.. //depot/projects/soc2005/fuse4bsd2/fuse_module/fuse.c#18 edit
.. //depot/projects/soc2005/fuse4bsd2/fuse_module/fuse.h#9 edit

Differences ...

==== //depot/projects/soc2005/fuse4bsd2/fuse_module/fuse.c#18 (text+ko) ====

@@ -478,7 +478,6 @@
 
 	/* Setting up fields of mine */
 	mtx_init(&data->msg_mtx, "mutex for fuse message list", NULL, MTX_DEF);
-	cv_init(&data->msg_cv, "cv to wake up fusedev_read");
 	STAILQ_INIT(&data->fmsg_head);
 	mtx_init(&data->ticket_mtx, "mutex for the fuse ticketer", NULL,
 	         MTX_DEF);
@@ -503,7 +502,6 @@
 
 	/* Driving off stage all that stuff thrown at device... */
 	mtx_destroy(&data->msg_mtx);
-	cv_destroy(&data->msg_cv);
 	mtx_destroy(&data->callback_mtx);
 	mtx_destroy(&data->ticket_mtx);
 
@@ -526,7 +524,7 @@
 	DEBUG2G("banning daemon\n");
 	mtx_lock(&data->msg_mtx);
 	data->dataflag |= FDAT_KICK;
-	cv_signal(&data->msg_cv);
+	wakeup_one(data);
 	mtx_unlock(&data->msg_mtx);
 }
 
@@ -693,7 +691,7 @@
 	mtx_lock(&tick->data->msg_mtx);
 	fuse_msgn_push(&tick->msgn);
 	DEBUG("ring the bell\n");
-	cv_signal(&tick->data->msg_cv);
+	wakeup_one(tick->data);
 	mtx_unlock(&tick->data->msg_mtx);
 }
 
@@ -1077,6 +1075,7 @@
 	fuprintf("fuse device being read on thread %d\n", uio->uio_td->td_tid);
 
 	mtx_lock(&data->msg_mtx);
+again:
 	if (fdata_kick_get(data)) {
 		DEBUG("we know early on that reader should be kicked so we don't wait for news\n");
 		mtx_unlock(&data->msg_mtx);
@@ -1084,13 +1083,23 @@
 	}
 
 	if ( ! (fmsgn = fdata_pop_msg(data))) {
-		err = cv_wait_sig(&data->msg_cv, &data->msg_mtx);
+		err = msleep(data, &data->msg_mtx, PCATCH, "fu msg", 0);
 		if (err != 0) {
 			mtx_unlock(&data->msg_mtx);
 			return (fdata_kick_get(data) ? ENODEV : err);
 		}
 		fmsgn = fdata_pop_msg(data);
 	}
+	if (! fmsgn) {
+		/*
+		 * We can get here if fuse daemon suddenly terminates,
+		 * eg, by being hit by a SIGKILL
+		 * -- and some other cases, too, tho not totally clear, when
+		 * (cv_signal/wakeup_one signals the whole process ?)
+		 */
+		DEBUG("no message on thread #%d\n", uio->uio_td->td_tid);
+		goto again;
+	}
 	mtx_unlock(&data->msg_mtx);
 
 	if (fdata_kick_get(data)) {
@@ -1105,16 +1114,6 @@
 		}
 		return (ENODEV); /* This should make the daemon get off of us */
 	}
-	if (! fmsgn) {
-		/*
-		 * We can get here if fuse daemon suddenly terminates,
-		 * eg, by being hit by a SIGKILL
-		 * -- and some other cases, too, tho not totally clear, when
-		 * (cv_signal signals the whole process ?)
-		 */
-		DEBUG("no message on thread #%d\n", uio->uio_td->td_tid);
-		return (EINTR);
-	}
 	DEBUG("message got on thread #%d\n", uio->uio_td->td_tid);
 
 	KASSERT(fmsgn->msg_bufdata || fmsgn->msg_bufsize == 0,

==== //depot/projects/soc2005/fuse4bsd2/fuse_module/fuse.h#9 (text+ko) ====

@@ -90,7 +90,6 @@
 
 struct fuse_data {
 	struct mtx msg_mtx;
-	struct cv msg_cv;
 	STAILQ_HEAD(, fuse_msg_node) fmsg_head;
 
 	struct mtx callback_mtx;