Btrfs: add support for multiple csum algorithms
This patch gives us the space we will need in order to have different csum
algorithims at some point in the future. We save the csum algorithim type
in the superblock, and use those instead of define's.
Signed-off-by: Josef Bacik <jbacik@redhat.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index dfd5ba0..3eb7c25 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -176,7 +176,9 @@
static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
int verify)
{
- char result[BTRFS_CRC32_SIZE];
+ u16 csum_size =
+ btrfs_super_csum_size(&root->fs_info->super_copy);
+ char *result = NULL;
unsigned long len;
unsigned long cur_len;
unsigned long offset = BTRFS_CSUM_SIZE;
@@ -186,6 +188,7 @@
unsigned long map_len;
int err;
u32 crc = ~(u32)0;
+ unsigned long inline_result;
len = buf->len - offset;
while(len > 0) {
@@ -204,25 +207,37 @@
offset += cur_len;
unmap_extent_buffer(buf, map_token, KM_USER0);
}
+ if (csum_size > sizeof(inline_result)) {
+ result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
+ if (!result)
+ return 1;
+ } else {
+ result = (char *)&inline_result;
+ }
+
btrfs_csum_final(crc, result);
if (verify) {
/* FIXME, this is not good */
- if (memcmp_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE)) {
+ if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
u32 val;
u32 found = 0;
- memcpy(&found, result, BTRFS_CRC32_SIZE);
+ memcpy(&found, result, csum_size);
- read_extent_buffer(buf, &val, 0, BTRFS_CRC32_SIZE);
+ read_extent_buffer(buf, &val, 0, csum_size);
printk("btrfs: %s checksum verify failed on %llu "
"wanted %X found %X level %d\n",
root->fs_info->sb->s_id,
buf->start, val, found, btrfs_header_level(buf));
+ if (result != (char *)&inline_result)
+ kfree(result);
return 1;
}
} else {
- write_extent_buffer(buf, result, 0, BTRFS_CRC32_SIZE);
+ write_extent_buffer(buf, result, 0, csum_size);
}
+ if (result != (char *)&inline_result)
+ kfree(result);
return 0;
}