In kernel space, r5l checksum will use crc32c: http://marc.info/?l=linux-raid&m=144598970529191 mdadm need to change too. This patch ports a simplified crc32c algorithm from kernel code, and used in super1.c:write_empty_r5l_meta_block(); Signed-off-by: Song Liu <songliubraving@xxxxxx> Signed-off-by: Shaohua Li <shli@xxxxxx> --- Makefile | 2 +- crc32c.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ super1.c | 11 +++---- 3 files changed, 109 insertions(+), 8 deletions(-) create mode 100644 crc32c.c diff --git a/Makefile b/Makefile index 544e6cb..fde2e63 100644 --- a/Makefile +++ b/Makefile @@ -133,7 +133,7 @@ OBJS = mdadm.o config.o policy.o mdstat.o ReadMe.o util.o maps.o lib.o \ mdopen.o super0.o super1.o super-ddf.o super-intel.o bitmap.o \ super-mbr.o super-gpt.o \ restripe.o sysfs.o sha1.o mapfile.o crc32.o sg_io.o msg.o xmalloc.o \ - platform-intel.o probe_roms.o + platform-intel.o probe_roms.o crc32c.o CHECK_OBJS = restripe.o sysfs.o maps.o lib.o xmalloc.o dlink.o diff --git a/crc32c.c b/crc32c.c new file mode 100644 index 0000000..156cba1 --- /dev/null +++ b/crc32c.c @@ -0,0 +1,104 @@ +/* + * Oct 28, 2015 Song Liu simplified the code and port it to mdadm + * + * Aug 8, 2011 Bob Pearson with help from Joakim Tjernlund and George Spelvin + * cleaned up code to current version of sparse and added the slicing-by-8 + * algorithm to the closely similar existing slicing-by-4 algorithm. + * + * Oct 15, 2000 Matt Domsch <Matt_Domsch@xxxxxxxx> + * Nicer crc32 functions/docs submitted by linux@xxxxxxxxxxx. Thanks! + * Code was from the public domain, copyright abandoned. Code was + * subsequently included in the kernel, thus was re-licensed under the + * GNU GPL v2. + * + * Oct 12, 2000 Matt Domsch <Matt_Domsch@xxxxxxxx> + * Same crc32 function was used in 5 other places in the kernel. + * I made one version, and deleted the others. + * There are various incantations of crc32(). Some use a seed of 0 or ~0. + * Some xor at the end with ~0. The generic crc32() function takes + * seed as an argument, and doesn't xor at the end. Then individual + * users can do whatever they need. + * drivers/net/smc9194.c uses seed ~0, doesn't xor with ~0. + * fs/jffs2 uses seed 0, doesn't xor with ~0. + * fs/partitions/efi.c uses seed ~0, xor's with ~0. + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#include <sys/types.h> +#include <asm/types.h> +#include <stdlib.h> + +/* + * There are multiple 16-bit CRC polynomials in common use, but this is + * *the* standard CRC-32 polynomial, first popularized by Ethernet. + * x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0 + */ +#define CRCPOLY_LE 0xedb88320 +#define CRCPOLY_BE 0x04c11db7 + +/* + * This is the CRC32c polynomial, as outlined by Castagnoli. + * x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+x^11+x^10+x^9+ + * x^8+x^6+x^0 + */ +#define CRC32C_POLY_LE 0x82F63B78 + +/** + * crc32_le_generic() - Calculate bitwise little-endian Ethernet AUTODIN II + * CRC32/CRC32C + * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for other + * uses, or the previous crc32/crc32c value if computing incrementally. + * @p: pointer to buffer over which CRC32/CRC32C is run + * @len: length of buffer @p + * @polynomial: CRC32/CRC32c LE polynomial + */ +static inline __u32 crc32_le_generic(__u32 crc, unsigned char const *p, + size_t len, __u32 polynomial) +{ + int i; + while (len--) { + crc ^= *p++; + for (i = 0; i < 8; i++) + crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0); + } + return crc; +} + +__u32 crc32_le(__u32 crc, unsigned char const *p, size_t len) +{ + return crc32_le_generic(crc, p, len, CRCPOLY_LE); +} + +__u32 crc32c_le(__u32 crc, unsigned char const *p, size_t len) +{ + return crc32_le_generic(crc, p, len, CRC32C_POLY_LE); +} + +/** + * crc32_be_generic() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32 + * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for + * other uses, or the previous crc32 value if computing incrementally. + * @p: pointer to buffer over which CRC32 is run + * @len: length of buffer @p + * @polynomial: CRC32 BE polynomial + */ +static inline __u32 crc32_be_generic(__u32 crc, unsigned char const *p, + size_t len, __u32 polynomial) +{ + int i; + while (len--) { + crc ^= *p++ << 24; + for (i = 0; i < 8; i++) + crc = + (crc << 1) ^ ((crc & 0x80000000) ? polynomial : + 0); + } + return crc; +} + +__u32 crc32_be(__u32 crc, unsigned char const *p, size_t len) +{ + return crc32_be_generic(crc, p, len, CRCPOLY_BE); +} diff --git a/super1.c b/super1.c index 58e6f9d..1735c2d 100644 --- a/super1.c +++ b/super1.c @@ -1625,10 +1625,7 @@ static unsigned long choose_bm_space(unsigned long devsize) static void free_super1(struct supertype *st); #define META_BLOCK_SIZE 4096 -unsigned long crc32( - unsigned long crc, - const unsigned char *buf, - unsigned len); +__u32 crc32c_le(__u32 crc, unsigned char const *p, size_t len); static int write_empty_r5l_meta_block(struct supertype *st, int fd) { @@ -1652,9 +1649,9 @@ static int write_empty_r5l_meta_block(struct supertype *st, int fd) mb->seq = __cpu_to_le64(random32()); mb->position = __cpu_to_le64(0); - crc = crc32(0xffffffff, sb->set_uuid, sizeof(sb->set_uuid)); - crc = crc32(crc, (void *)mb, META_BLOCK_SIZE); - mb->checksum = __cpu_to_le32(crc); + crc = crc32c_le(0xffffffff, sb->set_uuid, sizeof(sb->set_uuid)); + crc = crc32c_le(crc, (void *)mb, META_BLOCK_SIZE); + mb->checksum = crc; if (lseek64(fd, (sb->data_offset) * 512, 0) < 0LL) { pr_err("cannot seek to offset of the meta block\n"); -- 2.4.6 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
