From: Miklos Szeredi <mszeredi@suse.cz>
Date: Mon, 18 May 2015 14:55:20 +0000 (+0200)
Subject: libfuse: refcount fuse_chan objects
X-Git-Tag: fuse-3.0.0pre0~70^2~2
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1344908b6ce8b26ce9ff6e6269348eec904e14dc;p=qemu-gpiodev%2Flibfuse.git

libfuse: refcount fuse_chan objects

New functions: fuse_chan_get(), fuse_chan_put().  Removed function:
fuse_chan_destroy().
---

diff --git a/ChangeLog b/ChangeLog
index 5c1c267..8a65763 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2015-05-23  Miklos Szeredi <miklos@szeredi.hu>
+
+	* libfuse: refcount fuse_chan objects.  New functions:
+	fuse_chan_get(), fuse_chan_put().  Removed function:
+	fuse_chan_destroy().
+
 2015-04-23  Miklos Szeredi <miklos@szeredi.hu>
 
 	* libfuse: add FUSE_CAP_NO_OPEN_SUPPORT flag to ->init()
diff --git a/include/fuse_lowlevel.h b/include/fuse_lowlevel.h
index 20e7692..3cc9db5 100644
--- a/include/fuse_lowlevel.h
+++ b/include/fuse_lowlevel.h
@@ -1705,11 +1705,19 @@ int fuse_session_loop_mt(struct fuse_session *se);
 int fuse_chan_fd(struct fuse_chan *ch);
 
 /**
- * Destroy a channel
+ * Obtain counted reference to the channel
+ *
+ * @param ch the channel
+ * @return the channel
+ */
+struct fuse_chan *fuse_chan_get(struct fuse_chan *ch);
+
+/**
+ * Drop counted reference to a channel
  *
  * @param ch the channel
  */
-void fuse_chan_destroy(struct fuse_chan *ch);
+void fuse_chan_put(struct fuse_chan *ch);
 
 #ifdef __cplusplus
 }
diff --git a/lib/fuse_i.h b/lib/fuse_i.h
index 4bbcbd6..16adc69 100644
--- a/lib/fuse_i.h
+++ b/lib/fuse_i.h
@@ -23,6 +23,8 @@ struct fuse_session {
 struct fuse_chan {
 	struct fuse_session *se;
 
+	pthread_mutex_t lock;
+	int ctr;
 	int fd;
 };
 
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index f25d56f..e70733a 100755
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -2735,8 +2735,7 @@ static void fuse_ll_destroy(struct fuse_ll *f)
 void fuse_session_destroy(struct fuse_session *se)
 {
 	fuse_ll_destroy(se->f);
-	if (se->ch != NULL)
-		fuse_chan_destroy(se->ch);
+	fuse_chan_put(se->ch);
 	free(se);
 }
 
diff --git a/lib/fuse_session.c b/lib/fuse_session.c
index e919e73..42fe5c3 100644
--- a/lib/fuse_session.c
+++ b/lib/fuse_session.c
@@ -84,6 +84,8 @@ struct fuse_chan *fuse_chan_new(int fd)
 
 	memset(ch, 0, sizeof(*ch));
 	ch->fd = fd;
+	ch->ctr = 1;
+	fuse_mutex_init(&ch->lock);
 
 	return ch;
 }
@@ -98,9 +100,30 @@ struct fuse_session *fuse_chan_session(struct fuse_chan *ch)
 	return ch->se;
 }
 
-void fuse_chan_destroy(struct fuse_chan *ch)
+struct fuse_chan *fuse_chan_get(struct fuse_chan *ch)
 {
-	fuse_session_remove_chan(ch);
-	fuse_chan_close(ch);
-	free(ch);
+	assert(ch->ctr > 0);
+	pthread_mutex_lock(&ch->lock);
+	ch->ctr++;
+	pthread_mutex_unlock(&ch->lock);
+
+	return ch;
+}
+
+void fuse_chan_put(struct fuse_chan *ch)
+{
+	if (ch) {
+		pthread_mutex_lock(&ch->lock);
+		ch->ctr--;
+		if (!ch->ctr) {
+			pthread_mutex_unlock(&ch->lock);
+			fuse_session_remove_chan(ch);
+			fuse_chan_close(ch);
+			pthread_mutex_destroy(&ch->lock);
+			free(ch);
+		} else {
+			pthread_mutex_unlock(&ch->lock);
+		}
+
+	}
 }
diff --git a/lib/helper.c b/lib/helper.c
index e5550c9..cca21b5 100644
--- a/lib/helper.c
+++ b/lib/helper.c
@@ -243,8 +243,7 @@ void fuse_unmount(const char *mountpoint, struct fuse_chan *ch)
 	if (mountpoint) {
 		int fd = ch ? fuse_chan_clearfd(ch) : -1;
 		fuse_kern_unmount(mountpoint, fd);
-		if (ch)
-			fuse_chan_destroy(ch);
+		fuse_chan_put(ch);
 	}
 }