fuse: make fuse_direct_io() aware about AIO

The patch implements passing "struct fuse_io_priv *io" down the stack up to
fuse_send_read/write where it is used to submit request asynchronously.
io->async==0 designates synchronous processing.

Non-trivial part of the patch is changes in fuse_direct_io(): resources
like fuse requests and user pages cannot be released immediately in async
case.

Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>

1 files changed, 6 insertions, 1 deletions

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index aea072413c47..337169a406c9 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -732,6 +732,11 @@ struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages);
 struct fuse_req *fuse_get_req_for_background(struct fuse_conn *fc,
                                              unsigned npages);
 
+/*
+ * Increment reference count on request
+ */
+void __fuse_get_request(struct fuse_req *req);
+
 /**
  * Get a request, may fail with -ENOMEM,
  * useful for callers who doesn't use req->pages[]
@@ -846,7 +851,7 @@ int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 
 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
                  bool isdir);
-ssize_t fuse_direct_io(struct file *file, const struct iovec *iov,
+ssize_t fuse_direct_io(struct fuse_io_priv *io, const struct iovec *iov,
                        unsigned long nr_segs, size_t count, loff_t *ppos,
                        int write);
 long fuse_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg,