kernel/git/stable/linux.git/fs/ntfs, branch master

ntfs: support resident WOF decompression

2026-08-21T10:09:00+00:00

Extend WOF decompression to support files where the reparse named data attribute or the compressed chunks themselves are resident. Retrieve resident metadata using ntfs_attr_lookup() and copy compressed chunks directly from the resident attribute payload. Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: add non-resident WOF decompression

2026-08-21T10:08:57+00:00

Introduce non-resident Windows System Compression (WOF) decompression support. Add wof.c containing parse_wof_chunk_table() and ntfs_read_wof_compressed_block(), and routing them via transparent codec ops table with dynamic scratch memory allocation. Hook up ntfs_readpage/read_folio paths in aops.c to delegate to the WOF block reader when NInoWofCompressed is set. Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: implement codec ops for LZX and XPRESS

2026-08-21T10:06:45+00:00

Implement the transparent compression codec ops for XPRESS (4K, 8K, 16K) and LZX (32K) algorithms. The xpress_scratch_size, lzx_scratch_size, xpress_decompress_chunk, and lzx_decompress_chunk wrappers provide unified interfaces and use per-call dynamic scratch state allocation (avoiding global mutexed singletons). Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: port lzx/xpress decompressors from ntfs-3g-system-compression

2026-08-21T10:06:43+00:00

Port the LZX and XPRESS decompressors from the userspace ntfs-3g-system-compression plugin (Eric Biggers, https://github.com/ebiggers/ntfs-3g-system-compression) into the in-tree NTFS driver under lib/, and adapt them to the kernel environment. The upstream plugin implements WOF ("Windows Overlay Filesystem", a.k.a. system compression / "Compact OS") decompression for the NTFS-3G FUSE driver, and itself borrows the LZX/XPRESS decompressors that the same author wrote for wimlib (https://wimlib.net/). The XPRESS and LZX formats used here are identical to those used in WIM archives. This commit is the kernel-side port that lets fs/ntfs/wof.c read system-compressed files. The library keeps the upstream subtable-based Huffman decoder (root table + contiguous subtables decoded with MAKE_DECODE_TABLE_ENTRY()), so long codewords only need one extra lookup instead of bit-by-bit tree traversal. The ntfs_codec_ops interface exported to fs/ntfs/wof.c (ntfs_lzx32k_codec_ops and ntfs_xpress{4k,8k,16k}_codec_ops) matches what the WOF layer expects. Modifications made while porting from the upstream plugin: - Replace the variable LZX window order (2^15..2^21) with a fixed 32768-byte window, which is the only size WOF uses - Simplify the bitstream helper: - bitstream_ensure_bits() now guarantees 16 valid bits instead of the carried-over 17-bit refill path from wimlib. Neither LZX (max codeword length 16) nor XPRESS (max 15) needs more than 16 bits. - Refactor codes to satisfy checkpatch. Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: return errors from inode initialization

2026-08-21T10:06:41+00:00

ntfs_iget() previously converted only -ENOMEM from ntfs_read_locked_inode() into an ERR_PTR(). Other initialization errors left the inode on the normal return path after it had been unlocked. Return every non-zero initialization error after releasing the inode reference. Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: parse REPARSE_TAG_WOF

2026-08-21T10:06:38+00:00

Introduce parsing support for REPARSE_TAG_WOF reparse points. Rename ntfs_make_symlink() to ntfs_parse_reparse() since it now handles both symlinks and WOF reparse tags. Introduce NI_WofCompressed flag to indicate files compressed via Windows System Compression (WOF), and configure compressed block size accordingly (12 to 15 bits based on the format). Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: return errors from ntfs_attr_readall

2026-08-21T10:06:36+00:00

ntfs_attr_readall() currently loses the failure reason for attribute lookup, allocation, and read failures by returning NULL. Return ERR_PTR() with the original error instead. The reparse parser can then propagate allocation and I/O errors without treating them as filesystem corruption. Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: add WOF compression config option

2026-08-21T10:06:34+00:00

Add CONFIG_NTFS_FS_WOF_COMPRESSION for Windows system compression. Build XPRESS and LZX decoding code only when requested. Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: define LZNT1 codec ops under transparent codec interface

2026-08-21T10:06:33+00:00

Define the ntfs_lznt1_codec_ops structure containing decompress_pages and compress_subblock callbacks in compress.c, and export it in ntfs_codec.h. This structure binds existing LZNT1 decompress and compress helper functions under the unified transparent compression interface. Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon

ntfs: introduce transparent compression codec interface

2026-08-21T10:06:29+00:00

Introduce struct ntfs_codec_ops and enum ntfs_codec_id to provide a unified interface for compression and decompression algorithms. This interface supports WOF and LZNT1 decompression. Signed-off-by: Hyunchul Lee Signed-off-by: Namjae Jeon