From 1dcd705e16c26d804e08fdfa0ffeda7d7db23b67 Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <tst@schoebel-theuer>
Date: Sun, 1 Dec 2019 19:46:31 +0100
Subject: [PATCH] infra: adapt to block layer changes, kernel 4.11

---
 kernel/compat.h      | 14 ++++++++++++++
 kernel/lib_mapfree.c |  9 ++++++++-
 kernel/mars_bio.c    | 10 ++++++++++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/kernel/compat.h b/kernel/compat.h
index b5350d63..3f94166a 100644
--- a/kernel/compat.h
+++ b/kernel/compat.h
@@ -71,6 +71,20 @@ extern int _compat_unlink(
 #define MARS_HAS_BVEC_ITER
 #endif
 
+/* Detect upstream commits
+ * dc3b17cc8bf21307c7e076e7c778d5db756f7871
+ * d03f6cdc1fc422accb734c7c07a661a0018d8631
+ * b1d2dc5659b41741f5a29b2ade76ffb4e5bb13d8
+ * via fd2d332677c687ca90c12a47d6c377c547100b56
+ */
+#include <linux/blkdev.h>
+#ifdef BLK_QC_T_INTERNAL
+#define MARS_HAS_BDI_GET
+#endif
+#ifdef MARS_HAS_BDI_GET
+#include <linux/backing-dev.h>
+#endif
+
 /* adaptation to 4246a0b63bd8f56a1469b12eafeb875b1041a451 and 8ae126660fddbeebb9251a174e6fa45b6ad8f932 */
 #ifndef bio_io_error
 #define MARS_HAS_BI_ERROR
diff --git a/kernel/lib_mapfree.c b/kernel/lib_mapfree.c
index 862cabdb..1c219665 100644
--- a/kernel/lib_mapfree.c
+++ b/kernel/lib_mapfree.c
@@ -29,7 +29,6 @@
 #include <linux/string.h>
 #include <linux/list.h>
 #include <linux/types.h>
-#include <linux/blkdev.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
 #include <linux/file.h>
@@ -215,8 +214,16 @@ struct mapfree_info *mapfree_get(const char *name, int flags)
 		}
 
 		if (S_ISBLK(inode->i_mode)) {
+#ifdef MARS_HAS_BDI_GET
+			struct backing_dev_info *bdi =
+			  I_BDEV(inode)->bd_bdi;
+			MARS_INF("changing blkdev readahead from %lu to %d\n",
+				 bdi->ra_pages, ra);
+			bdi->ra_pages = ra;
+#else /* deprecated old code */
 			MARS_INF("changing blkdev readahead from %lu to %d\n", inode->i_bdev->bd_disk->queue->backing_dev_info.ra_pages, ra);
 			inode->i_bdev->bd_disk->queue->backing_dev_info.ra_pages = ra;
+#endif
 		}
 
 		if (flags & O_DIRECT) {	// never share them
diff --git a/kernel/mars_bio.c b/kernel/mars_bio.c
index 99e1d476..633bc804 100644
--- a/kernel/mars_bio.c
+++ b/kernel/mars_bio.c
@@ -791,6 +791,9 @@ static int bio_switch(struct bio_brick *brick)
 			struct address_space *mapping;
 			struct inode *inode;
 			struct request_queue *q;
+#ifdef MARS_HAS_BDI_GET
+			struct backing_dev_info *bdi;
+#endif
 
 			brick->mf = mapfree_get(path, flags);
 			if (unlikely(!brick->mf)) {
@@ -820,8 +823,15 @@ static int bio_switch(struct bio_brick *brick)
 				goto done;
 			}
 
+#ifdef MARS_HAS_BDI_GET
+			bdi = I_BDEV(inode)->bd_bdi;
+			MARS_INF("'%s' ra_pages OLD=%lu NEW=%d\n", path,
+				 bdi->ra_pages, brick->ra_pages);
+			bdi->ra_pages = brick->ra_pages;
+#else
 			MARS_INF("'%s' ra_pages OLD=%lu NEW=%d\n", path, q->backing_dev_info.ra_pages, brick->ra_pages);
 			q->backing_dev_info.ra_pages = brick->ra_pages;
+#endif
 
 			q->nr_requests = bio_nr_requests;