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Message-ID: <39d06f0d-f30d-c7c7-39e6-e4a566e6d5f4@paragon-software.com>
Date:   Mon, 8 May 2023 16:39:17 +0400
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Subject: [PATCH 08/10] fs/ntfs3: Add ability to format new mft records with
 bigger/smaller header
Content-Language: en-US
From:   Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
To:     <ntfs3@lists.linux.dev>
CC:     Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        <linux-fsdevel@vger.kernel.org>
References: <b21a4bc9-166d-2631-d73b-cb4e802ff69e@paragon-software.com>
In-Reply-To: <b21a4bc9-166d-2631-d73b-cb4e802ff69e@paragon-software.com>
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Just define in ntfs.h
     #define MFTRECORD_FIXUP_OFFSET  MFTRECORD_FIXUP_OFFSET_1
or
     #define MFTRECORD_FIXUP_OFFSET  MFTRECORD_FIXUP_OFFSET_3

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
---
  fs/ntfs3/ntfs.h   | 9 +++++++++
  fs/ntfs3/record.c | 2 ++
  fs/ntfs3/super.c  | 6 +++---
  3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/ntfs3/ntfs.h b/fs/ntfs3/ntfs.h
index 3ec2eaf31996..98b76d1b09e7 100644
--- a/fs/ntfs3/ntfs.h
+++ b/fs/ntfs3/ntfs.h
@@ -288,6 +288,15 @@ struct MFT_REC {

  #define MFTRECORD_FIXUP_OFFSET_1 offsetof(struct MFT_REC, res)
  #define MFTRECORD_FIXUP_OFFSET_3 offsetof(struct MFT_REC, fixups)
+/*
+ * define MFTRECORD_FIXUP_OFFSET as MFTRECORD_FIXUP_OFFSET_3 (0x30)
+ * to format new mft records with bigger header (as current ntfs.sys does)
+ *
+ * define MFTRECORD_FIXUP_OFFSET as MFTRECORD_FIXUP_OFFSET_1 (0x2A)
+ * to format new mft records with smaller header (as old ntfs.sys did)
+ * Both variants are valid.
+ */
+#define MFTRECORD_FIXUP_OFFSET  MFTRECORD_FIXUP_OFFSET_1

  static_assert(MFTRECORD_FIXUP_OFFSET_1 == 0x2A);
  static_assert(MFTRECORD_FIXUP_OFFSET_3 == 0x30);
diff --git a/fs/ntfs3/record.c b/fs/ntfs3/record.c
index e73ca2df42eb..c12ebffc94da 100644
--- a/fs/ntfs3/record.c
+++ b/fs/ntfs3/record.c
@@ -388,6 +388,8 @@ int mi_format_new(struct mft_inode *mi, struct 
ntfs_sb_info *sbi, CLST rno,

      rec->seq = cpu_to_le16(seq);
      rec->flags = RECORD_FLAG_IN_USE | flags;
+    if (MFTRECORD_FIXUP_OFFSET == MFTRECORD_FIXUP_OFFSET_3)
+        rec->mft_record = cpu_to_le32(rno);

      mi->dirty = true;

diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 12019bfe1325..7ab0a79c7d84 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -867,7 +867,7 @@ static int ntfs_init_from_boot(struct super_block 
*sb, u32 sector_size,
      }

      sbi->max_bytes_per_attr =
-        record_size - ALIGN(MFTRECORD_FIXUP_OFFSET_1, 8) -
+        record_size - ALIGN(MFTRECORD_FIXUP_OFFSET, 8) -
          ALIGN(((record_size >> SECTOR_SHIFT) * sizeof(short)), 8) -
          ALIGN(sizeof(enum ATTR_TYPE), 8);

@@ -909,10 +909,10 @@ static int ntfs_init_from_boot(struct super_block 
*sb, u32 sector_size,

      sbi->new_rec = rec;
      rec->rhdr.sign = NTFS_FILE_SIGNATURE;
-    rec->rhdr.fix_off = cpu_to_le16(MFTRECORD_FIXUP_OFFSET_1);
+    rec->rhdr.fix_off = cpu_to_le16(MFTRECORD_FIXUP_OFFSET);
      fn = (sbi->record_size >> SECTOR_SHIFT) + 1;
      rec->rhdr.fix_num = cpu_to_le16(fn);
-    ao = ALIGN(MFTRECORD_FIXUP_OFFSET_1 + sizeof(short) * fn, 8);
+    ao = ALIGN(MFTRECORD_FIXUP_OFFSET + sizeof(short) * fn, 8);
      rec->attr_off = cpu_to_le16(ao);
      rec->used = cpu_to_le32(ao + ALIGN(sizeof(enum ATTR_TYPE), 8));
      rec->total = cpu_to_le32(sbi->record_size);
-- 
2.34.1