[Btrfs-devel] [PATCH] calculate checksums during mkfs
Josef Bacik
jwhiter at redhat.com
Mon Jun 25 15:11:52 PDT 2007
Hello,
I apologize if this is wrong, I'm trying to wrap a bunch of stuff up before I go
to OLS. This patch properly calculates checksums for tree and superblock blocks
during a mkfs. I have tested this on my box and it works well. I copied the
crc32c stuff from the kernel, let me know if my formatting is wrong and I will
try to fix it before I head out tomorrow. Thank you,
Josef
diff -r d2a40206ee8c Makefile
--- a/Makefile Fri Jun 22 14:50:47 2007 -0400
+++ b/Makefile Mon Jun 25 11:40:06 2007 -0400
@@ -2,7 +2,7 @@ CFLAGS = -g -Wall -fno-strict-aliasing -
CFLAGS = -g -Wall -fno-strict-aliasing -Werror
objects = ctree.o disk-io.o radix-tree.o extent-tree.o print-tree.o \
root-tree.o dir-item.o hash.o file-item.o inode-item.o \
- inode-map.o \
+ inode-map.o crc32c.o\
#
CHECKFLAGS=-D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise \
-Wuninitialized -Wshadow -Wundef
diff -r d2a40206ee8c ctree.h
--- a/ctree.h Fri Jun 22 14:50:47 2007 -0400
+++ b/ctree.h Mon Jun 25 11:40:06 2007 -0400
@@ -40,6 +40,8 @@ struct btrfs_trans_handle;
/* 32 bytes in various csum fields */
#define BTRFS_CSUM_SIZE 32
+/* four bytes for CRC32 */
+#define BTRFS_CRC32_SIZE 4
#define BTRFS_FT_UNKNOWN 0
#define BTRFS_FT_REG_FILE 1
diff -r d2a40206ee8c disk-io.c
--- a/disk-io.c Fri Jun 22 14:50:47 2007 -0400
+++ b/disk-io.c Mon Jun 25 13:58:46 2007 -0400
@@ -29,6 +29,7 @@
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
+#include "crc32c.h"
static int allocated_blocks = 0;
int cache_max = 10000;
@@ -159,6 +160,30 @@ int clean_tree_block(struct btrfs_trans_
return 0;
}
+int btrfs_csum_node(struct btrfs_root * root, struct btrfs_node *node)
+{
+ u32 crc;
+ size_t len = root->blocksize - BTRFS_CSUM_SIZE;
+
+ crc = crc32c(0, (char *)(node) + BTRFS_CSUM_SIZE, len);
+ memcpy(node->header.csum, &crc, BTRFS_CRC32_SIZE);
+ return 0;
+}
+
+int btrfs_csum_super(struct btrfs_super_block *super, int size)
+{
+ u32 crc;
+ char block[size];
+ size_t len = size - BTRFS_CSUM_SIZE;
+
+ memset(block, 0, size);
+ memcpy(block, super, sizeof(*super));
+
+ crc = crc32c(0, block + BTRFS_CSUM_SIZE, len);
+ memcpy(super->csum, &crc, BTRFS_CRC32_SIZE);
+ return 0;
+}
+
int write_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_buffer *buf)
{
@@ -169,6 +194,9 @@ int write_tree_block(struct btrfs_trans_
btrfs_map_bh_to_logical(root, buf, buf->blocknr);
if (check_tree_block(root, buf))
BUG();
+
+ btrfs_csum_node(root, &buf->node);
+
ret = pwrite(buf->fd, &buf->node, root->blocksize,
buf->dev_blocknr * root->blocksize);
if (ret != root->blocksize)
@@ -361,7 +389,10 @@ int write_ctree_super(struct btrfs_trans
*root, struct btrfs_super_block *s)
{
int ret;
+
btrfs_set_super_root(s, root->fs_info->tree_root->node->blocknr);
+ btrfs_csum_super(s, root->blocksize);
+
ret = pwrite(root->fs_info->fp, s, sizeof(*s),
BTRFS_SUPER_INFO_OFFSET);
if (ret != sizeof(*s)) {
diff -r d2a40206ee8c disk-io.h
--- a/disk-io.h Fri Jun 22 14:50:47 2007 -0400
+++ b/disk-io.h Mon Jun 25 13:29:41 2007 -0400
@@ -51,6 +51,8 @@ int write_ctree_super(struct btrfs_trans
struct btrfs_super_block *s);
int btrfs_map_bh_to_logical(struct btrfs_root *root, struct btrfs_buffer *bh,
u64 logical);
+int btrfs_csum_super(struct btrfs_super_block *super, int blocksize);
+int btrfs_csum_node(struct btrfs_root * root, struct btrfs_node *node);
#define BTRFS_SUPER_INFO_OFFSET (16 * 1024)
#endif
--- btrfs-progs/crc32c.h.josef 2007-06-25 14:00:39.000000000 -0400
+++ btrfs-progs/crc32c.h 2007-06-25 12:43:23.000000000 -0400
@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2007 Red Hat. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License v2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#ifndef __CRC32C__
+#define __CRC32C__
+
+#include "kerncompat.h"
+
+u32 crc32c_le(u32 seed, unsigned char const *data, size_t length);
+
+#define crc32c(seed, data, length) crc32c_le(seed, (unsigned char const *)data, length)
+#endif
--- btrfs-progs/crc32c.c.josef 2007-06-25 14:00:44.000000000 -0400
+++ btrfs-progs/crc32c.c 2007-06-25 12:43:31.000000000 -0400
@@ -0,0 +1,103 @@
+/*
+ * Copied from the kernel source code, lib/libcrc32c.c.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+#include "kerncompat.h"
+#include "crc32c.h"
+
+/*
+ * This is the CRC-32C table
+ * Generated with:
+ * width = 32 bits
+ * poly = 0x1EDC6F41
+ * reflect input bytes = true
+ * reflect output bytes = true
+ */
+
+static const u32 crc32c_table[256] = {
+ 0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
+ 0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
+ 0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
+ 0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
+ 0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
+ 0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
+ 0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
+ 0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
+ 0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
+ 0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
+ 0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
+ 0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
+ 0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
+ 0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
+ 0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
+ 0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
+ 0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
+ 0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
+ 0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
+ 0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
+ 0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
+ 0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
+ 0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
+ 0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
+ 0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
+ 0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
+ 0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
+ 0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
+ 0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
+ 0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
+ 0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
+ 0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
+ 0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
+ 0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
+ 0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
+ 0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
+ 0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
+ 0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
+ 0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
+ 0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
+ 0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
+ 0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
+ 0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
+ 0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
+ 0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
+ 0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
+ 0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
+ 0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
+ 0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
+ 0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
+ 0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
+ 0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
+ 0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
+ 0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
+ 0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
+ 0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
+ 0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
+ 0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
+ 0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
+ 0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
+ 0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
+ 0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
+ 0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
+ 0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
+};
+
+/*
+ * Steps through buffer one byte at at time, calculates reflected
+ * crc using table.
+ */
+
+u32 crc32c_le(u32 seed, unsigned char const *data, size_t length)
+{
+ u32 crc = cpu_to_le32(seed);
+
+ while (length--)
+ crc =
+ crc32c_table[(crc ^ *data++) & 0xFFL] ^ (crc >> 8);
+
+ return le32_to_cpu(crc);
+}
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