Removed 'async_read' field in fuse_conn_info

This is redundant with the capability flags in `wants` and `capable`.

4 files changed, 19 insertions, 13 deletions

diff --git a/ChangeLog.rst b/ChangeLog.rst
index 2b2dba9..dc243f2 100644
--- a/ChangeLog.rst
+++ b/ChangeLog.rst
@@ -1,6 +1,12 @@
 Unreleased Changes
 ==================
 
+* Removed the `async_read` field from `struct fuse_conn_info`. To
+  determine if the kernel supports asynchronous reads, file systems
+  should check the `FUSE_CAP_ASYNC_READ` bit of the `capable`
+  field. To enable/disable asynchronous reads, file systems should set
+  the flag in the `wanted` field.
+
 * The `fuse_parse_cmdline` function no longer prints out help when the
   ``--verbose`` or ``--help`` flags are given. This needs to be done
   by the file system (e.g. using the `fuse_cmdline_help()`,
diff --git a/include/fuse_common.h b/include/fuse_common.h
index 6eadc90..4a0e94b 100644
--- a/include/fuse_common.h
+++ b/include/fuse_common.h
@@ -157,11 +157,6 @@ struct fuse_conn_info {
 	unsigned proto_minor;
 
 	/**
-	 * Is asynchronous read supported (read-write)
-	 */
-	unsigned async_read;
-
-	/**
 	 * Maximum size of the write buffer
 	 */
 	unsigned max_write;
diff --git a/lib/fuse_i.h b/lib/fuse_i.h
index 446842a..c8aa279 100644
--- a/lib/fuse_i.h
+++ b/lib/fuse_i.h
@@ -67,6 +67,8 @@ struct fuse_session {
 	int writeback_cache;
 	int no_writeback_cache;
 	int clone_fd;
+	int async_read;
+	int sync_read;
 	struct fuse_lowlevel_ops op;
 	int got_init;
 	struct cuse_data *cuse_data;
diff --git a/lib/fuse_lowlevel.c b/lib/fuse_lowlevel.c
index 7648788..8bf457a 100644
--- a/lib/fuse_lowlevel.c
+++ b/lib/fuse_lowlevel.c
@@ -1849,12 +1849,13 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 	}
 
 	if (arg->minor >= 6) {
-		if (f->conn.async_read)
-			f->conn.async_read = arg->flags & FUSE_ASYNC_READ;
 		if (arg->max_readahead < f->conn.max_readahead)
 			f->conn.max_readahead = arg->max_readahead;
-		if (arg->flags & FUSE_ASYNC_READ)
+		if (arg->flags & FUSE_ASYNC_READ) {
 			f->conn.capable |= FUSE_CAP_ASYNC_READ;
+			/* Enable by default */
+			f->conn.want |= FUSE_CAP_ASYNC_READ;
+		}
 		if (arg->flags & FUSE_POSIX_LOCKS)
 			f->conn.capable |= FUSE_CAP_POSIX_LOCKS;
 		if (arg->flags & FUSE_ATOMIC_O_TRUNC)
@@ -1878,7 +1879,6 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 		if (arg->flags & FUSE_NO_OPEN_SUPPORT)
 			f->conn.capable |= FUSE_CAP_NO_OPEN_SUPPORT;
 	} else {
-		f->conn.async_read = 0;
 		f->conn.max_readahead = 0;
 	}
 
@@ -1947,12 +1947,16 @@ static void do_init(fuse_req_t req, fuse_ino_t nodeid, const void *inarg)
 		f->conn.want &= ~FUSE_CAP_ASYNC_DIO;
 	if (f->no_writeback_cache)
 		f->conn.want &= ~FUSE_CAP_WRITEBACK_CACHE;
+	if (f->async_read)
+		f->conn.want |= FUSE_CAP_ASYNC_READ;
+	if (f->sync_read)
+		f->conn.want &= ~FUSE_CAP_ASYNC_READ;
 
 	/* Always enable big writes, this is superseded
 	   by the max_write option */
 	outarg.flags |= FUSE_BIG_WRITES;
 
-	if (f->conn.async_read || (f->conn.want & FUSE_CAP_ASYNC_READ))
+	if (f->conn.want & FUSE_CAP_ASYNC_READ)
 		outarg.flags |= FUSE_ASYNC_READ;
 	if (f->conn.want & FUSE_CAP_POSIX_LOCKS)
 		outarg.flags |= FUSE_POSIX_LOCKS;
@@ -2558,8 +2562,8 @@ static const struct fuse_opt fuse_ll_opts[] = {
 	{ "max_background=%u", offsetof(struct fuse_session, conn.max_background), 0 },
 	{ "congestion_threshold=%u",
 	  offsetof(struct fuse_session, conn.congestion_threshold), 0 },
-	{ "async_read", offsetof(struct fuse_session, conn.async_read), 1 },
-	{ "sync_read", offsetof(struct fuse_session, conn.async_read), 0 },
+	{ "sync_read", offsetof(struct fuse_session, sync_read), 1 },
+	{ "async_read", offsetof(struct fuse_session, async_read), 1 },
 	{ "atomic_o_trunc", offsetof(struct fuse_session, atomic_o_trunc), 1},
 	{ "no_remote_lock", offsetof(struct fuse_session, no_remote_posix_lock), 1},
 	{ "no_remote_lock", offsetof(struct fuse_session, no_remote_flock), 1},
@@ -2825,7 +2829,6 @@ struct fuse_session *fuse_session_new(struct fuse_args *args,
 		fprintf(stderr, "fuse: failed to allocate fuse object\n");
 		goto out1;
 	}
-	se->conn.async_read = 1;
 	se->conn.max_write = UINT_MAX;
 	se->conn.max_readahead = UINT_MAX;
 	se->atomic_o_trunc = 0;