From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q12E9oYc055443 for ; Thu, 2 Feb 2012 08:09:50 -0600 Received: from bombadil.infradead.org (173-166-109-252-newengland.hfc.comcastbusiness.net [173.166.109.252]) by cuda.sgi.com with ESMTP id 95O52Zfc9kkdMGbi (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Thu, 02 Feb 2012 06:09:48 -0800 (PST) Date: Thu, 2 Feb 2012 09:09:47 -0500 From: Christoph Hellwig Subject: Re: Trailing garbage in event tracing output Message-ID: <20120202140947.GA16244@infradead.org> References: <20120202115211.GA1259@nsrc.org> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="VbJkn9YxBvnuCH5J" Content-Disposition: inline In-Reply-To: <20120202115211.GA1259@nsrc.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Brian Candler Cc: xfs@oss.sgi.com --VbJkn9YxBvnuCH5J Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Feb 02, 2012 at 11:52:11AM +0000, Brian Candler wrote: > Just a minor issue, but when I did some XFS tracing using the instructions > at http://lwn.net/Articles/341899/ I found that there was trailing garbage > in the filenames logged in xfs_lookup. Example: > (where I think the real filename was "000000295aSl688"). I would guess the > logger is expecting null-terminated strings but they aren't. That's indeed the case. See the attched patch to fix the issue. To apply it against the 3.0 kernel you'll probably have to edit it to remove "linux-2.6/" directory in the filenames. --VbJkn9YxBvnuCH5J Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=xfs-fix-filename-tracing From: Christoph Hellwig Subject: xfs: trace xfs_name strings correctly Strings store in an xfs_name structure are often not NUL terminated, print them using the correct printf specifiers that make use of the string length store in the xfs_name structure. Reported-by: Brian Candler Signed-off-by: Christoph Hellwig Index: xfs/fs/xfs/xfs_trace.h =================================================================== --- xfs.orig/fs/xfs/xfs_trace.h 2012-02-02 13:11:38.355063111 +0100 +++ xfs/fs/xfs/xfs_trace.h 2012-02-02 14:58:45.800242652 +0100 @@ -627,16 +627,19 @@ DECLARE_EVENT_CLASS(xfs_namespace_class, TP_STRUCT__entry( __field(dev_t, dev) __field(xfs_ino_t, dp_ino) + __field(int, namelen) __dynamic_array(char, name, name->len) ), TP_fast_assign( __entry->dev = VFS_I(dp)->i_sb->s_dev; __entry->dp_ino = dp->i_ino; + __entry->namelen = name->len; memcpy(__get_str(name), name->name, name->len); ), - TP_printk("dev %d:%d dp ino 0x%llx name %s", + TP_printk("dev %d:%d dp ino 0x%llx name %.*s", MAJOR(__entry->dev), MINOR(__entry->dev), __entry->dp_ino, + __entry->namelen, __get_str(name)) ) @@ -658,6 +661,8 @@ TRACE_EVENT(xfs_rename, __field(dev_t, dev) __field(xfs_ino_t, src_dp_ino) __field(xfs_ino_t, target_dp_ino) + __field(int, src_namelen) + __field(int, target_namelen) __dynamic_array(char, src_name, src_name->len) __dynamic_array(char, target_name, target_name->len) ), @@ -665,15 +670,20 @@ TRACE_EVENT(xfs_rename, __entry->dev = VFS_I(src_dp)->i_sb->s_dev; __entry->src_dp_ino = src_dp->i_ino; __entry->target_dp_ino = target_dp->i_ino; + __entry->src_namelen = src_name->len; + __entry->target_namelen = target_name->len; memcpy(__get_str(src_name), src_name->name, src_name->len); - memcpy(__get_str(target_name), target_name->name, target_name->len); + memcpy(__get_str(target_name), target_name->name, + target_name->len); ), TP_printk("dev %d:%d src dp ino 0x%llx target dp ino 0x%llx" - " src name %s target name %s", + " src name %.*s target name %.*s", MAJOR(__entry->dev), MINOR(__entry->dev), __entry->src_dp_ino, __entry->target_dp_ino, + __entry->src_namelen, __get_str(src_name), + __entry->target_namelen, __get_str(target_name)) ) --VbJkn9YxBvnuCH5J Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs --VbJkn9YxBvnuCH5J--