[PATCH 10/12] block_dev: set REQ_NOMERGE for O_ATOMIC writes

[Christoph Hellwig <hch@xxxxxx>]

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 fs/block_dev.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 3c47614a4b32..4dd5c54cdefb 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -242,6 +242,10 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
 		task_io_account_write(ret);
 	}
 
+	/* don't merge atomic requests to avoid going over the limit */
+	if (iocb->ki_filp->f_flags & O_ATOMIC)
+		bio.bi_opf |= REQ_NOMERGE;
+
 	qc = submit_bio(&bio);
 	for (;;) {
 		set_current_state(TASK_UNINTERRUPTIBLE);
@@ -377,6 +381,10 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 			task_io_account_write(bio->bi_iter.bi_size);
 		}
 
+		/* don't merge atomic requests to avoid going over the limit */
+		if (iocb->ki_filp->f_flags & O_ATOMIC)
+			bio->bi_opf |= REQ_NOMERGE;
+
 		dio->size += bio->bi_iter.bi_size;
 		pos += bio->bi_iter.bi_size;
 
-- 
2.11.0