Merge branch 'clone_fd'

5 files changed, 90 insertions, 11 deletions

diff --git a/lib/fuse_i.h b/lib/fuse_i.h
index 4bbcbd6..62af9f2 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;
 };
 
@@ -78,6 +80,7 @@ struct fuse_ll {
 	int no_async_dio;
 	int writeback_cache;
 	int no_writeback_cache;
+	int clone_fd;
 	struct fuse_lowlevel_ops op;
 	int got_init;
 	struct cuse_data *cuse_data;
diff --git a/lib/fuse_loop_mt.c b/lib/fuse_loop_mt.c
index 8f4dceb..6d7f051 100755
--- a/lib/fuse_loop_mt.c
+++ b/lib/fuse_loop_mt.c
@@ -20,6 +20,7 @@
 #include <semaphore.h>
 #include <errno.h>
 #include <sys/time.h>
+#include <sys/ioctl.h>
 
 /* Environment var controlling the thread stack size */
 #define ENVNAME_THREAD_STACK "FUSE_THREAD_STACK"
@@ -30,6 +31,7 @@ struct fuse_worker {
 	pthread_t thread_id;
 	size_t bufsize;
 	struct fuse_buf fbuf;
+	struct fuse_chan *ch;
 	struct fuse_mt *mt;
 };
 
@@ -74,7 +76,7 @@ static void *fuse_do_work(void *data)
 		int res;
 
 		pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
-		res = fuse_session_receive_buf(mt->se, &w->fbuf, mt->prevch);
+		res = fuse_session_receive_buf(mt->se, &w->fbuf, w->ch);
 		pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
 		if (res == -EINTR)
 			continue;
@@ -110,7 +112,7 @@ static void *fuse_do_work(void *data)
 			fuse_loop_start_thread(mt);
 		pthread_mutex_unlock(&mt->lock);
 
-		fuse_session_process_buf(mt->se, &w->fbuf, mt->prevch);
+		fuse_session_process_buf(mt->se, &w->fbuf, w->ch);
 
 		pthread_mutex_lock(&mt->lock);
 		if (!isforget)
@@ -127,6 +129,7 @@ static void *fuse_do_work(void *data)
 
 			pthread_detach(w->thread_id);
 			free(w->fbuf.mem);
+			fuse_chan_put(w->ch);
 			free(w);
 			return NULL;
 		}
@@ -171,9 +174,46 @@ int fuse_start_thread(pthread_t *thread_id, void *(*func)(void *), void *arg)
 	return 0;
 }
 
+static struct fuse_chan *fuse_clone_chan(struct fuse_mt *mt)
+{
+	int res;
+	int clonefd;
+	uint32_t masterfd;
+	struct fuse_chan *newch;
+	const char *devname = "/dev/fuse";
+
+#ifndef O_CLOEXEC
+#define O_CLOEXEC 0
+#endif
+	clonefd = open(devname, O_RDWR | O_CLOEXEC);
+	if (clonefd == -1) {
+		fprintf(stderr, "fuse: failed to open %s: %s\n", devname,
+			strerror(errno));
+		return NULL;
+	}
+	fcntl(clonefd, F_SETFD, FD_CLOEXEC);
+
+	masterfd = fuse_chan_fd(mt->prevch);
+	res = ioctl(clonefd, FUSE_DEV_IOC_CLONE, &masterfd);
+	if (res == -1) {
+		fprintf(stderr, "fuse: failed to clone device fd: %s\n",
+			strerror(errno));
+		close(clonefd);
+		mt->se->f->clone_fd = 0;
+
+		return fuse_chan_get(mt->prevch);
+	}
+	newch = fuse_chan_new(clonefd);
+	if (newch == NULL)
+		close(clonefd);
+
+	return newch;
+}
+
 static int fuse_loop_start_thread(struct fuse_mt *mt)
 {
 	int res;
+
 	struct fuse_worker *w = malloc(sizeof(struct fuse_worker));
 	if (!w) {
 		fprintf(stderr, "fuse: failed to allocate worker structure\n");
@@ -183,8 +223,18 @@ static int fuse_loop_start_thread(struct fuse_mt *mt)
 	w->fbuf.mem = NULL;
 	w->mt = mt;
 
+
+	if (mt->se->f->clone_fd) {
+		w->ch = fuse_clone_chan(mt);
+		if (!w->ch)
+			return -1;
+	} else {
+		w->ch = fuse_chan_get(mt->prevch);
+	}
+
 	res = fuse_start_thread(&w->thread_id, fuse_do_work, w);
 	if (res == -1) {
+		fuse_chan_put(w->ch);
 		free(w);
 		return -1;
 	}
@@ -202,6 +252,7 @@ static void fuse_join_worker(struct fuse_mt *mt, struct fuse_worker *w)
 	list_del_worker(w);
 	pthread_mutex_unlock(&mt->lock);
 	free(w->fbuf.mem);
+	fuse_chan_put(w->ch);
 	free(w);
 }
 
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 0d66ccc..c5108f7 100755
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -134,6 +134,8 @@ void fuse_free_req(fuse_req_t req)
 	req->u.ni.data = NULL;
 	list_del_req(req);
 	ctr = --req->ctr;
+	fuse_chan_put(req->ch);
+	req->ch = NULL;
 	pthread_mutex_unlock(&f->lock);
 	if (!ctr)
 		destroy_req(req);
@@ -2538,7 +2540,7 @@ void fuse_session_process_buf(struct fuse_session *se,
 	req->ctx.uid = in->uid;
 	req->ctx.gid = in->gid;
 	req->ctx.pid = in->pid;
-	req->ch = ch;
+	req->ch = fuse_chan_get(ch);
 
 	err = EIO;
 	if (!f->got_init) {
@@ -2655,6 +2657,7 @@ static const struct fuse_opt fuse_ll_opts[] = {
 	{ "writeback_cache", offsetof(struct fuse_ll, writeback_cache), 1},
 	{ "no_writeback_cache", offsetof(struct fuse_ll, no_writeback_cache), 1},
 	{ "time_gran=%u", offsetof(struct fuse_ll, conn.time_gran), 0 },
+	{ "clone_fd", offsetof(struct fuse_ll, clone_fd), 1 },
 	FUSE_OPT_KEY("max_read=", FUSE_OPT_KEY_DISCARD),
 	FUSE_OPT_KEY("-h", KEY_HELP),
 	FUSE_OPT_KEY("--help", KEY_HELP),
@@ -2691,6 +2694,7 @@ static void fuse_ll_help(void)
 "    -o [no_]async_dio        asynchronous direct I/O\n"
 "    -o [no_]writeback_cache  asynchronous, buffered writes\n"
 "    -o time_gran=N           time granularity in nsec\n"
+"    -o clone_fd              clone fuse device file descriptors\n"
 );
 }
 
@@ -2735,8 +2739,7 @@ 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 bfdc990..28c6310 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);
 	}
 }