Add support for ring creation in fuse_lowlevel.c

Signed-off-by: Bernd Schubert <bschubert@ddn.com>

5 files changed, 63 insertions, 3 deletions

diff --git a/lib/fuse_i.h b/lib/fuse_i.h
index b643e90..23e58ef 100644
--- a/lib/fuse_i.h
+++ b/lib/fuse_i.h
@@ -61,6 +61,7 @@ struct fuse_notify_req {
 };
 
 struct fuse_session_uring {
+	bool enable;
 	unsigned int q_depth;
 	struct fuse_ring_pool *pool;
 };
diff --git a/lib/fuse_loop_mt.c b/lib/fuse_loop_mt.c
index 46e2d6e..046256c 100644
--- a/lib/fuse_loop_mt.c
+++ b/lib/fuse_loop_mt.c
@@ -15,6 +15,7 @@
 #include "fuse_misc.h"
 #include "fuse_kernel.h"
 #include "fuse_i.h"
+#include "fuse_uring_i.h"
 #include "util.h"
 
 #include <stdio.h>
@@ -407,12 +408,16 @@ int err;
 			fuse_join_worker(&mt, mt.main.next);
 
 		err = mt.error;
+
+		if (se->uring.pool)
+			fuse_uring_stop(se);
 	}
 
 	pthread_mutex_destroy(&se->mt_lock);
 	if(se->error != 0)
 		err = se->error;
 
+
 	if (created_config) {
 		fuse_loop_cfg_destroy(config);
 		config = NULL;
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 4a4c71e..433594f 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -18,6 +18,7 @@
 #include "fuse_misc.h"
 #include "mount_util.h"
 #include "util.h"
+#include "fuse_uring_i.h"
 
 #include <pthread.h>
 #include <stdatomic.h>
@@ -34,6 +35,7 @@
 #include <assert.h>
 #include <sys/file.h>
 #include <sys/ioctl.h>
+#include <stdalign.h>
 
 #ifdef USDT_ENABLED
 #include "usdt.h"
@@ -46,7 +48,6 @@
 #define F_SETPIPE_SZ	(F_LINUX_SPECIFIC_BASE + 7)
 #endif
 
-
 #define PARAM(inarg) (((char *)(inarg)) + sizeof(*(inarg)))
 #define OFFSET_MAX 0x7fffffffffffffffLL
 
@@ -169,6 +170,10 @@ static void list_add_req(struct fuse_req *req, struct fuse_req *next)
 
 static void destroy_req(fuse_req_t req)
 {
+	if (req->is_uring) {
+		fuse_log(FUSE_LOG_ERR, "Refusing to destruct uring req\n");
+		return;
+	}
 	assert(req->ch == NULL);
 	pthread_mutex_destroy(&req->lock);
 	free(req);
@@ -179,7 +184,11 @@ void fuse_free_req(fuse_req_t req)
 	int ctr;
 	struct fuse_session *se = req->se;
 
-	if (se->conn.no_interrupt) {
+	/* XXX: for now no support for interrupts with io-uring
+	 *      It actually might work alreasdy, though. But then would add
+	 *      a lock across ring queues.
+	 */
+	if (se->conn.no_interrupt || req->is_uring) {
 		ctr = --req->ref_cnt;
 		fuse_chan_put(req->ch);
 		req->ch = NULL;
@@ -209,6 +218,7 @@ static struct fuse_req *fuse_ll_alloc_req(struct fuse_session *se)
 		req->ref_cnt = 1;
 		list_init_req(req);
 		pthread_mutex_init(&req->lock, NULL);
+		req->is_uring = false;
 	}
 
 	return req;
@@ -2415,6 +2425,8 @@ _do_init(fuse_req_t req, const fuse_ino_t nodeid, const void *op_in,
 	uint64_t outargflags = 0;
 	bool buf_reallocable = se->buf_reallocable;
 	(void) nodeid;
+	bool enable_io_uring = false;
+
 	if (se->debug) {
 		fuse_log(FUSE_LOG_DEBUG, "INIT: %u.%u\n", arg->major, arg->minor);
 		if (arg->major == 7 && arg->minor >= 6) {
@@ -2673,6 +2685,10 @@ _do_init(fuse_req_t req, const fuse_ino_t nodeid, const void *op_in,
 	}
 	if (se->conn.want_ext & FUSE_CAP_NO_EXPORT_SUPPORT)
 		outargflags |= FUSE_NO_EXPORT_SUPPORT;
+	if (se->uring.enable && se->conn.want_ext & FUSE_CAP_OVER_IO_URING) {
+		outargflags |= FUSE_OVER_IO_URING;
+		enable_io_uring = true;
+	}
 
 	if (inargflags & FUSE_INIT_EXT) {
 		outargflags |= FUSE_INIT_EXT;
@@ -2721,6 +2737,17 @@ _do_init(fuse_req_t req, const fuse_ino_t nodeid, const void *op_in,
 		outargsize = FUSE_COMPAT_22_INIT_OUT_SIZE;
 
 	send_reply_ok(req, &outarg, outargsize);
+
+	/* XXX: Split the start, and send SQEs only after send_reply_ok() */
+	if (enable_io_uring) {
+		int ring_rc = fuse_uring_start(se);
+
+		if (ring_rc != 0) {
+			fuse_log(FUSE_LOG_ERR, "fuse: failed to start io-uring: %s\n",
+				 strerror(ring_rc));
+			fuse_session_exit(se);
+		}
+	}
 }
 
 static __attribute__((no_sanitize("thread"))) void
diff --git a/lib/fuse_uring_i.h b/lib/fuse_uring_i.h
index fefb8a0..e9f2989 100644
--- a/lib/fuse_uring_i.h
+++ b/lib/fuse_uring_i.h
@@ -8,11 +8,38 @@
 #ifndef FUSE_URING_I_H_
 #define FUSE_URING_I_H_
 
+#include "fuse_config.h"
 #include "fuse_lowlevel.h"
+#include "fuse_kernel.h"
+
+#ifndef HAVE_URING
+#include "util.h"
+#endif
+
+void fuse_session_process_uring_cqe(struct fuse_session *se,
+				    struct fuse_req *req,
+				    struct fuse_in_header *in, void *in_header,
+				    void *in_payload, size_t payload_len);
+
+#ifdef HAVE_URING
 
 struct fuse_in_header;
 
 int fuse_uring_start(struct fuse_session *se);
 int fuse_uring_stop(struct fuse_session *se);
 
+#else // HAVE_URING
+
+static inline int fuse_uring_start(struct fuse_session *se FUSE_VAR_UNUSED)
+{
+	return -ENOTSUP;
+}
+
+static inline int fuse_uring_stop(struct fuse_session *se FUSE_VAR_UNUSED)
+{
+	return -ENOTSUP;
+}
+
+#endif // HAVE_URING
+
 #endif // FUSE_URING_I_H_
diff --git a/lib/util.h b/lib/util.h
index d1939cf..96b59d3 100644
--- a/lib/util.h
+++ b/lib/util.h
@@ -28,7 +28,7 @@ static inline uint64_t fuse_higher_32_bits(uint64_t nr)
 }
 
 #ifndef FUSE_VAR_UNUSED
-#define FUSE_VAR_UNUSED(var) (__attribute__((unused)) var)
+#define FUSE_VAR_UNUSED __attribute__((__unused__))
 #endif
 
 #define container_of(ptr, type, member)                      \