From fc503912fd81c6c5c0194814ea0f741bc42ed377 Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@google.com>
Date: Wed, 14 Apr 2021 18:47:28 +0000
Subject: [PATCH] Revert "Revert "dm bufio: subtract the number of initial
 sectors..."

Revert submission 1672946

Reason for revert: getting back to mainline with a proper fix
Reverted Changes:
I96ee9a0a8:Revert "dm bufio: subtract the number of initial s...
I23d4da47b:Revert "dm verity: fix FEC for RS roots unaligned ...

Change-Id: Ie37a318c2a2fd61969f1102452b47b4e376071d9
---
 drivers/md/dm-bufio.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index fce4cbf9529d..50f3e673729c 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1526,6 +1526,10 @@ EXPORT_SYMBOL_GPL(dm_bufio_get_block_size);
 sector_t dm_bufio_get_device_size(struct dm_bufio_client *c)
 {
 	sector_t s = i_size_read(c->bdev->bd_inode) >> SECTOR_SHIFT;
+	if (s >= c->start)
+		s -= c->start;
+	else
+		s = 0;
 	if (likely(c->sectors_per_block_bits >= 0))
 		s >>= c->sectors_per_block_bits;
 	else