fuse: skip blocking on allocations of synchronous requests

A task may have at most one synchronous request allocated. So these
requests need not be otherwise limited.

The patch re-works fuse_get_req() to follow this idea.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 4958f80..17ec1f7 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -583,7 +583,7 @@
 	fc->khctr = 0;
 	fc->polled_files = RB_ROOT;
 	fc->reqctr = 0;
-	fc->blocked = 1;
+	fc->blocked = 0;
 	fc->initialized = 0;
 	fc->attr_version = 1;
 	get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
@@ -883,7 +883,6 @@
 		fc->max_write = max_t(unsigned, 4096, fc->max_write);
 		fc->conn_init = 1;
 	}
-	fc->blocked = 0;
 	fc->initialized = 1;
 	wake_up_all(&fc->blocked_waitq);
 }