mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 13:41:51 +00:00
94ae8c3fee
- Check data compressibility with some heuristics (copied from
btrfs):
- should_compress() final decision is is_compressible(data)
- Cleanup compress/lz77.h leaving only lz77_compress() exposed:
- Move parts to compress/lz77.c, while removing the rest of it
because they were either unused, used only once, were
implemented wrong (thanks to David Howells for the help)
- Updated the compression parameters (still compatible with
Windows implementation) trading off ~20% compression ratio
for ~40% performance:
- min match len: 3 -> 4
- max distance: 8KiB -> 1KiB
- hash table type: u32 * -> u64 *
Known bugs:
This implementation currently works fine in general, but breaks with
some payloads used during testing. Investigation ongoing, to be
fixed in a next commit.
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Co-developed-by: David Howells <dhowells@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
91 lines
2.8 KiB
C
91 lines
2.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Copyright (C) 2024, SUSE LLC
|
|
*
|
|
* Authors: Enzo Matsumiya <ematsumiya@suse.de>
|
|
*
|
|
* This file implements I/O compression support for SMB2 messages (SMB 3.1.1 only).
|
|
* See compress/ for implementation details of each algorithm.
|
|
*
|
|
* References:
|
|
* MS-SMB2 "3.1.4.4 Compressing the Message" - for compression details
|
|
* MS-SMB2 "3.1.5.3 Decompressing the Chained Message" - for decompression details
|
|
* MS-XCA - for details of the supported algorithms
|
|
*/
|
|
#ifndef _SMB_COMPRESS_H
|
|
#define _SMB_COMPRESS_H
|
|
|
|
#include <linux/uio.h>
|
|
#include <linux/kernel.h>
|
|
#include "../common/smb2pdu.h"
|
|
#include "cifsglob.h"
|
|
|
|
/* sizeof(smb2_compression_hdr) - sizeof(OriginalPayloadSize) */
|
|
#define SMB_COMPRESS_HDR_LEN 16
|
|
/* sizeof(smb2_compression_payload_hdr) - sizeof(OriginalPayloadSize) */
|
|
#define SMB_COMPRESS_PAYLOAD_HDR_LEN 8
|
|
#define SMB_COMPRESS_MIN_LEN PAGE_SIZE
|
|
|
|
#ifdef CONFIG_CIFS_COMPRESSION
|
|
typedef int (*compress_send_fn)(struct TCP_Server_Info *, int, struct smb_rqst *);
|
|
|
|
int smb_compress(struct TCP_Server_Info *server, struct smb_rqst *rq, compress_send_fn send_fn);
|
|
|
|
/**
|
|
* should_compress() - Determines if a request (write) or the response to a
|
|
* request (read) should be compressed.
|
|
* @tcon: tcon of the request is being sent to
|
|
* @rqst: request to evaluate
|
|
*
|
|
* Return: true iff:
|
|
* - compression was successfully negotiated with server
|
|
* - server has enabled compression for the share
|
|
* - it's a read or write request
|
|
* - (write only) request length is >= SMB_COMPRESS_MIN_LEN
|
|
* - (write only) is_compressible() returns 1
|
|
*
|
|
* Return false otherwise.
|
|
*/
|
|
bool should_compress(const struct cifs_tcon *tcon, const struct smb_rqst *rq);
|
|
|
|
/**
|
|
* smb_compress_alg_valid() - Validate a compression algorithm.
|
|
* @alg: Compression algorithm to check.
|
|
* @valid_none: Conditional check whether NONE algorithm should be
|
|
* considered valid or not.
|
|
*
|
|
* If @alg is SMB3_COMPRESS_NONE, this function returns @valid_none.
|
|
*
|
|
* Note that 'NONE' (0) compressor type is considered invalid in protocol
|
|
* negotiation, as it's never requested to/returned from the server.
|
|
*
|
|
* Return: true if @alg is valid/supported, false otherwise.
|
|
*/
|
|
static __always_inline int smb_compress_alg_valid(__le16 alg, bool valid_none)
|
|
{
|
|
if (alg == SMB3_COMPRESS_NONE)
|
|
return valid_none;
|
|
|
|
if (alg == SMB3_COMPRESS_LZ77 || alg == SMB3_COMPRESS_PATTERN)
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
#else /* !CONFIG_CIFS_COMPRESSION */
|
|
static inline int smb_compress(void *unused1, void *unused2, void *unused3)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static inline bool should_compress(void *unused1, void *unused2)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline int smb_compress_alg_valid(__le16 unused1, bool unused2)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
#endif /* !CONFIG_CIFS_COMPRESSION */
|
|
#endif /* _SMB_COMPRESS_H */
|