From 4623a01bdc07756ab9b3102786f56c104bff744b Mon Sep 17 00:00:00 2001
From: Josef Bacik <jwhiter@redhat.com>
Date: Thu, 28 Jun 2007 16:20:29 -0400
Subject: calculate checksums during IO

---
 disk-io.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

(limited to 'disk-io.c')

diff --git a/disk-io.c b/disk-io.c
index cb5d1420..2c92d54e 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -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_handle *trans, struct btrfs_root *root,
 	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_root *root, struct btrfs_super_block *super)
+{
+	u32 crc;
+	char block[root->blocksize];
+	size_t len = root->blocksize - BTRFS_CSUM_SIZE;
+
+	memset(block, 0, root->blocksize);
+	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_handle *trans, struct btrfs_root *root,
 	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_handle *trans, struct btrfs_root
 		      *root, struct btrfs_super_block *s)
 {
 	int ret;
+
 	btrfs_set_super_root(s, root->fs_info->tree_root->node->blocknr);
+	btrfs_csum_super(root, s);
+
 	ret = pwrite(root->fs_info->fp, s, sizeof(*s),
 		     BTRFS_SUPER_INFO_OFFSET);
 	if (ret != sizeof(*s)) {
-- 
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