From 4f0e77f8f098753bd9835d5a31c435aaab79dd86 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Pali=20Roh=C3=A1r?= Date: Tue, 12 Apr 2022 11:20:43 +0200 Subject: [PATCH] fs: ext4: Use CRC-16 implementation from linux/crc16.h MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Implementation in linux/crc16.h provides standard CRC-16 algorithm with polynomial x^16 + x^15 + x^2 + 1. Use it and remove duplicate ext4 CRC-16 specific code. Signed-off-by: Pali Rohár Reviewed-by: Stefan Roese --- fs/ext4/Makefile | 2 +- fs/ext4/crc16.c | 62 ------------------------------------------- fs/ext4/crc16.h | 16 ----------- fs/ext4/ext4_common.c | 8 +++--- fs/ext4/ext4_common.h | 2 +- 5 files changed, 6 insertions(+), 84 deletions(-) delete mode 100644 fs/ext4/crc16.c delete mode 100644 fs/ext4/crc16.h diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile index c2544beee3..6ae44a2d0a 100644 --- a/fs/ext4/Makefile +++ b/fs/ext4/Makefile @@ -8,4 +8,4 @@ # obj-y := ext4fs.o ext4_common.o dev.o -obj-$(CONFIG_EXT4_WRITE) += ext4_write.o ext4_journal.o crc16.o +obj-$(CONFIG_EXT4_WRITE) += ext4_write.o ext4_journal.o diff --git a/fs/ext4/crc16.c b/fs/ext4/crc16.c deleted file mode 100644 index 3afb34daef..0000000000 --- a/fs/ext4/crc16.c +++ /dev/null @@ -1,62 +0,0 @@ -/* - * crc16.c - * - * This source code is licensed under the GNU General Public License, - * Version 2. See the file COPYING for more details. - */ - -#include -#include -#include -#include "crc16.h" - -/** CRC table for the CRC-16. The poly is 0x8005 (x16 + x15 + x2 + 1) */ -static __u16 const crc16_table[256] = { - 0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241, - 0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440, - 0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40, - 0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841, - 0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40, - 0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41, - 0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641, - 0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040, - 0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240, - 0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441, - 0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41, - 0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840, - 0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41, - 0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40, - 0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640, - 0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041, - 0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240, - 0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441, - 0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41, - 0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840, - 0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41, - 0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40, - 0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640, - 0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041, - 0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241, - 0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440, - 0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40, - 0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841, - 0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40, - 0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41, - 0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641, - 0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040 -}; - -/** - * Compute the CRC-16 for the data buffer -*/ - -unsigned int ext2fs_crc16(unsigned int crc, - const void *buffer, unsigned int len) -{ - const unsigned char *cp = buffer; - - while (len--) - crc = (((crc >> 8) & 0xffU) ^ - crc16_table[(crc ^ *cp++) & 0xffU]) & 0x0000ffffU; - return crc; -} diff --git a/fs/ext4/crc16.h b/fs/ext4/crc16.h deleted file mode 100644 index 5fd113a56c..0000000000 --- a/fs/ext4/crc16.h +++ /dev/null @@ -1,16 +0,0 @@ -/* - * crc16.h - CRC-16 routine - * Implements the standard CRC-16: - * Width 16 - * Poly 0x8005 (x16 + x15 + x2 + 1) - * Init 0 - * - * Copyright (c) 2005 Ben Gardner - * This source code is licensed under the GNU General Public License, - * Version 2. See the file COPYING for more details. - */ -#ifndef __CRC16_H -#define __CRC16_H -extern unsigned int ext2fs_crc16(unsigned int crc, - const void *buffer, unsigned int len); -#endif diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index c52cc400e1..d49ba4a995 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -427,14 +427,14 @@ uint16_t ext4fs_checksum_update(uint32_t i) if (le32_to_cpu(fs->sb->feature_ro_compat) & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) { int offset = offsetof(struct ext2_block_group, bg_checksum); - crc = ext2fs_crc16(~0, fs->sb->unique_id, + crc = crc16(~0, (__u8 *)fs->sb->unique_id, sizeof(fs->sb->unique_id)); - crc = ext2fs_crc16(crc, &le32_i, sizeof(le32_i)); - crc = ext2fs_crc16(crc, desc, offset); + crc = crc16(crc, (__u8 *)&le32_i, sizeof(le32_i)); + crc = crc16(crc, (__u8 *)desc, offset); offset += sizeof(desc->bg_checksum); /* skip checksum */ assert(offset == sizeof(*desc)); if (offset < fs->gdsize) { - crc = ext2fs_crc16(crc, (__u8 *)desc + offset, + crc = crc16(crc, (__u8 *)desc + offset, fs->gdsize - offset); } } diff --git a/fs/ext4/ext4_common.h b/fs/ext4/ext4_common.h index beaee9c80b..504c708b06 100644 --- a/fs/ext4/ext4_common.h +++ b/fs/ext4/ext4_common.h @@ -27,7 +27,7 @@ #include #if defined(CONFIG_EXT4_WRITE) #include "ext4_journal.h" -#include "crc16.h" +#include #endif #define YES 1 -- 2.39.5