Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx2.netapp.com ([216.240.18.37]:55265 "EHLO mx2.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964983Ab2CGBrE (ORCPT ); Tue, 6 Mar 2012 20:47:04 -0500 From: Weston Andros Adamson To: Trond.Myklebust@netapp.com Cc: chuck.lever@oracle.com, linux-nfs@vger.kernel.org, Weston Andros Adamson Subject: [PATCH] NFS: add filehandle crc for debug display Date: Tue, 6 Mar 2012 20:46:43 -0500 Message-Id: <1331084803-21460-1-git-send-email-dros@netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: Match wireshark's CRC-32 hash for easier debugging Signed-off-by: Weston Andros Adamson --- Reposted with Trond's suggestion of splitting out hash calculation to a separate function. Now dprintks can use a fh's CRC instead of the multiline nfs_display_fhandle() when it makes sense. fs/nfs/inode.c | 23 ++++++++++++++++++++--- include/linux/nfs_fs.h | 8 ++++++++ 2 files changed, 28 insertions(+), 3 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 99a4f52..3919ceb 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include @@ -1045,7 +1046,23 @@ struct nfs_fh *nfs_alloc_fhandle(void) return fh; } -/** +#ifdef RPC_DEBUG +/* + * _nfs_display_fhandle_hash - calculate the crc32 hash for the filehandle + * in the same way that wireshark does + * + * @fh: file handle + * + * For debugging only. + */ +u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh) +{ + /* wireshark uses 32-bit AUTODIN crc and does a bitwise + * not on the result */ + return ~crc32(0xFFFFFFFF, &fh->data[0], fh->size); +} + +/* * _nfs_display_fhandle - display an NFS file handle on the console * * @fh: file handle to display @@ -1053,7 +1070,6 @@ struct nfs_fh *nfs_alloc_fhandle(void) * * For debugging only. */ -#ifdef RPC_DEBUG void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption) { unsigned short i; @@ -1063,7 +1079,8 @@ void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption) return; } - printk(KERN_DEFAULT "%s at %p is %u bytes:\n", caption, fh, fh->size); + printk(KERN_DEFAULT "%s at %p is %u bytes, crc: 0x%08x:\n", + caption, fh, fh->size, _nfs_display_fhandle_hash(fh)); for (i = 0; i < fh->size; i += 16) { __be32 *pos = (__be32 *)&fh->data[i]; diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index c07a757..ce8e436 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -396,6 +396,11 @@ static inline void nfs_free_fhandle(const struct nfs_fh *fh) } #ifdef RPC_DEBUG +extern u32 _nfs_display_fhandle_hash(const struct nfs_fh *fh); +static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh) +{ + return _nfs_display_fhandle_hash(fh); +} extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption); #define nfs_display_fhandle(fh, caption) \ do { \ @@ -403,6 +408,9 @@ extern void _nfs_display_fhandle(const struct nfs_fh *fh, const char *caption); _nfs_display_fhandle(fh, caption); \ } while (0) #else +static inline u32 nfs_display_fhandle_hash(const struct nfs_fh *fh) +{ +} static inline void nfs_display_fhandle(const struct nfs_fh *fh, const char *caption) { -- 1.7.4.4