From 800917a21e3c34d3fbeb46bdd1901808dde89fc4 Mon Sep 17 00:00:00 2001
From: Manuel Bentele
Date: Tue, 15 Sep 2020 14:23:38 +0200
Subject: Ported RAW file format kernel module to Linux 4.18.x

---
 kernel/xloop_file_fmt_raw.c | 14 +++++++++++++-
 kernel/xloop_main.c         |  8 ++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/kernel/xloop_file_fmt_raw.c b/kernel/xloop_file_fmt_raw.c
index c8e90ef..f963e92 100644
--- a/kernel/xloop_file_fmt_raw.c
+++ b/kernel/xloop_file_fmt_raw.c
@@ -176,11 +176,16 @@ static int __raw_file_fmt_rw_aio(struct xloop_device *xlo,
 	int nr_bvec = 0;
 	int ret;
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 1, 0)
 	rq_for_each_bvec(tmp, rq, rq_iter)
 		nr_bvec++;
+#endif
 
 	if (rq->bio != rq->biotail) {
-
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 1, 0)
+		__rq_for_each_bio(bio, rq)
+			nr_bvec += bio_segments(bio);
+#endif
 		bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
 				     GFP_NOIO);
 		if (!bvec)
@@ -193,7 +198,11 @@ static int __raw_file_fmt_rw_aio(struct xloop_device *xlo,
 		 * copy bio->bi_iov_vec to new bvec. The rq_for_each_bvec
 		 * API will take care of all details for us.
 		 */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 1, 0)
 		rq_for_each_bvec(tmp, rq, rq_iter) {
+#else
+		rq_for_each_segment(tmp, rq, rq_iter) {
+#endif
 			*bvec = tmp;
 			bvec++;
 		}
@@ -207,6 +216,9 @@ static int __raw_file_fmt_rw_aio(struct xloop_device *xlo,
 		 */
 		offset = bio->bi_iter.bi_bvec_done;
 		bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter);
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5, 1, 0)
+		nr_bvec = bio_segments(bio);
+#endif
 	}
 	atomic_set(&cmd->ref, 2);
 
diff --git a/kernel/xloop_main.c b/kernel/xloop_main.c
index c6a6c83..703044f 100644
--- a/kernel/xloop_main.c
+++ b/kernel/xloop_main.c
@@ -1471,7 +1471,11 @@ static int xlo_ioctl(struct block_device *bdev, fmode_t mode,
 	case XLOOP_SET_BLOCK_SIZE:
 		if (!(mode & FMODE_WRITE) && !capable(CAP_SYS_ADMIN))
 			return -EPERM;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 4, 0)
 		fallthrough;
+#else
+		/* fall through */
+#endif
 	default:
 		err = xlo_simple_ioctl(xlo, cmd, arg);
 		break;
@@ -1623,7 +1627,11 @@ static int xlo_compat_ioctl(struct block_device *bdev, fmode_t mode,
 	case XLOOP_SET_STATUS64:
 	case XLOOP_CONFIGURE:
 		arg = (unsigned long) compat_ptr(arg);
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(5, 4, 0)
 		fallthrough;
+#else
+		/* fall through */
+#endif
 	case XLOOP_SET_FD:
 	case XLOOP_CHANGE_FD:
 	case XLOOP_SET_BLOCK_SIZE:
-- 
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