[PATCH 30/40] iomap: add per-iomap_iter private data

[Christoph Hellwig <hch@xxxxxx>]

Allow the file system to keep state for all iterations.  For now only
wire it up for direct I/O as there is an immediate need for it.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 fs/iomap/direct-io.c  | 3 +++
 include/linux/iomap.h | 1 +
 2 files changed, 4 insertions(+)

diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
index a434b1829545d..63ee37b40fd8f 100644
--- a/fs/iomap/direct-io.c
+++ b/fs/iomap/direct-io.c
@@ -477,6 +477,7 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 		.pos		= iocb->ki_pos,
 		.len		= iov_iter_count(iter),
 		.flags		= IOMAP_DIRECT,
+		.private	= iocb->private,
 	};
 	loff_t end = iomi.pos + iomi.len - 1, ret = 0;
 	bool wait_for_completion =
@@ -504,6 +505,8 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
 	dio->submit.waiter = current;
 	dio->submit.poll_bio = NULL;
 
+	WRITE_ONCE(iocb->private, NULL);
+
 	if (iov_iter_rw(iter) == READ) {
 		if (iomi.pos >= dio->i_size)
 			goto out_free_dio;
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 97a3a2edb5850..3cc5ee01066d0 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -188,6 +188,7 @@ struct iomap_iter {
 	unsigned flags;
 	struct iomap iomap;
 	struct iomap srcmap;
+	void *private;
 };
 
 int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops);
-- 
2.30.2