From: Chris Mason <clm@fb.com>
Date: Wed, 3 Aug 2016 21:05:46 +0000 (-0700)
Subject: Btrfs: fix __MAX_CSUM_ITEMS
X-Git-Tag: v5.15~12838^2~26
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=42049bf60db4c01e0432fc861463dcd3208c0d93;p=platform%2Fkernel%2Flinux-starfive.git

Btrfs: fix __MAX_CSUM_ITEMS

Jeff Mahoney's cleanup commit (14a1e067b4) wasn't correct for csums on
machines where the pagesize >= metadata blocksize.

This just reverts the relevant hunks to bring the old math back.

Signed-off-by: Chris Mason <clm@fb.com>
---

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index 2fc803d..d0d571c 100644
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -27,8 +27,9 @@
 #include "print-tree.h"
 #include "compression.h"
 
-#define __MAX_CSUM_ITEMS(r, size) \
-	((unsigned long)(((BTRFS_MAX_ITEM_SIZE(r) * 2) / size) - 1))
+#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
+				   sizeof(struct btrfs_item) * 2) / \
+				  size) - 1))
 
 #define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
 				       PAGE_SIZE))