int ntfs_write_mst_block (struct page * page, struct writeback_control * wbc);
This function is for writing pages belonging to non-resident, mst protected attributes to their backing store. The only supported attributes are index allocation and $MFT/$DATA. Both directory inodes and index inodes are supported for the index allocation case.
The page must remain locked for the duration of the write because we apply the mst fixups, write, and then undo the fixups, so if we were to unlock the page before undoing the fixups, any other user of the page will see the page contents as corrupt.
We clear the page uptodate flag for the duration of the function to ensure exclusion for the $MFT/$DATA case against someone mapping an mft record we are about to apply the mst fixups to.
Return 0 on success and -errno on error.
Based on ntfs_write_block, ntfs_mft_writepage, and write_mft_record_nolock.