From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757354AbYDLXBn (ORCPT ); Sat, 12 Apr 2008 19:01:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757550AbYDLW6z (ORCPT ); Sat, 12 Apr 2008 18:58:55 -0400 Received: from mail.deathmatch.net ([70.167.247.36]:35384 "EHLO mail.deathmatch.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753666AbYDLW6t (ORCPT ); Sat, 12 Apr 2008 18:58:49 -0400 From: Bob Copeland To: linux-kernel@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, Bob Copeland Subject: [PATCH 6/7] omfs: add checksumming routines Date: Sat, 12 Apr 2008 18:58:40 -0400 Message-Id: <1208041121-26787-7-git-send-email-me@bobcopeland.com> X-Mailer: git-send-email 1.5.4.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org OMFS checksums the metadata of all filesystem objects. This change adds the necessary functions to do so. Signed-off-by: Bob Copeland --- fs/omfs/checksum.c | 31 +++++++++++++++++++++++++++++++ 1 files changed, 31 insertions(+), 0 deletions(-) create mode 100644 fs/omfs/checksum.c diff --git a/fs/omfs/checksum.c b/fs/omfs/checksum.c new file mode 100644 index 0000000..cbd0471 --- /dev/null +++ b/fs/omfs/checksum.c @@ -0,0 +1,31 @@ +#include +#include +#include +#include "omfs.h" + +/* + * Update the header checksums for a dirty inode based on its contents. + * Caller is expected to hold the buffer head underlying oi and mark it + * dirty. + */ +int omfs_update_checksums(struct omfs_inode *oi) +{ + int ret = 0; + int xor, i, ofs = 0, count; + u16 crc = 0; + unsigned char *ptr = (unsigned char *) oi; + + count = be32_to_cpu(oi->i_head.h_body_size); + ofs = sizeof(struct omfs_header); + + crc = crc_itu_t(crc, ptr + ofs, count); + oi->i_head.h_crc = cpu_to_be16(crc); + + xor = ptr[0]; + for (i = 1; i < OMFS_XOR_COUNT; i++) + xor ^= ptr[i]; + + oi->i_head.h_check_xor = xor; + + return ret; +} -- 1.5.4.2