[PATCH 3/8] fs/ntfs3: Fix alternative boot searching

[Konstantin Komarovc <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>]

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@xxxxxxxxxxxxxxxxxxxx>
---
 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 71c80c578feb..d2951b23f52a 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -846,7 +846,7 @@ 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;
@@ -855,6 +855,9 @@ 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);
@@ -1087,9 +1090,9 @@ 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)
@@ -1103,6 +1106,7 @@ 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);
--
2.34.1