From 5d556122f59a4d78e7a9f370dedbda0f732e9916 Mon Sep 17 00:00:00 2001
From: Goldwyn Rodrigues <rgoldwyn@suse.com>
Date: Tue, 20 Jun 2017 07:05:45 -0500
Subject: [PATCH 06/11] fs: Introduce IOMAP_NOWAIT
Git-commit: a38d1243704f501a4c42de1db1062ff6eba83453
Patch-mainline: v4.13-rc1
References: FATE#321994
IOCB_NOWAIT translates to IOMAP_NOWAIT for iomaps.
This is used by XFS in the XFS patch.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/iomap.c | 8 ++++++++
include/linux/iomap.h | 1 +
2 files changed, 9 insertions(+)
diff --git a/fs/iomap.c b/fs/iomap.c
index 4b10892967a5..7dfe7ad6c35c 100644
--- a/fs/iomap.c
+++ b/fs/iomap.c
@@ -881,6 +881,14 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
flags |= IOMAP_WRITE;
}
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (filemap_range_has_page(mapping, start, end)) {
+ ret = -EAGAIN;
+ goto out_free_dio;
+ }
+ flags |= IOMAP_NOWAIT;
+ }
+
ret = filemap_write_and_wait_range(mapping, start, end);
if (ret)
goto out_free_dio;
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index f753e788da31..69f4e9470084 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -52,6 +52,7 @@ struct iomap {
#define IOMAP_REPORT (1 << 2) /* report extent status, e.g. FIEMAP */
#define IOMAP_FAULT (1 << 3) /* mapping for page fault */
#define IOMAP_DIRECT (1 << 4) /* direct I/O */
+#define IOMAP_NOWAIT (1 << 5) /* Don't wait for writeback */
struct iomap_ops {
/*
--
2.12.3