[PATCH AUTOSEL 6.5 08/52] fs/ntfs3: Fix alternative boot searching

[Sasha Levin <sashal@kernel.org>]

From: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

[ Upstream commit dcc852e509a4cba0ac6ac734077cef260e4e0fe6 ]

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/ntfs3/super.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 18a8bc73b8e2d..98545060580ac 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -838,7 +838,7 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
 	struct ntfs_sb_info *sbi = sb->s_fs_info;
 	int err;
 	u32 mb, gb, boot_sector_size, sct_per_clst, record_size;
-	u64 sectors, clusters, mlcn, mlcn2;
+	u64 sectors, clusters, mlcn, mlcn2, dev_size0;
 	struct NTFS_BOOT *boot;
 	struct buffer_head *bh;
 	struct MFT_REC *rec;
@@ -847,6 +847,9 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
 	u32 boot_off = 0;
 	const char *hint = "Primary boot";
 
+	/* Save original dev_size. Used with alternative boot. */
+	dev_size0 = dev_size;
+
 	sbi->volume.blocks = dev_size >> PAGE_SHIFT;
 
 	bh = ntfs_bread(sb, 0);
@@ -1079,9 +1082,9 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
 	}
 
 out:
-	if (err == -EINVAL && !bh->b_blocknr && dev_size > PAGE_SHIFT) {
+	if (err == -EINVAL && !bh->b_blocknr && dev_size0 > PAGE_SHIFT) {
 		u32 block_size = min_t(u32, sector_size, PAGE_SIZE);
-		u64 lbo = dev_size - sizeof(*boot);
+		u64 lbo = dev_size0 - sizeof(*boot);
 
 		/*
 	 	 * Try alternative boot (last sector)
@@ -1095,6 +1098,7 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
 
 		boot_off = lbo & (block_size - 1);
 		hint = "Alternative boot";
+		dev_size = dev_size0; /* restore original size. */
 		goto check_boot;
 	}
 	brelse(bh);
-- 
2.42.0