From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759536AbZBLR5k (ORCPT ); Thu, 12 Feb 2009 12:57:40 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755690AbZBLR5b (ORCPT ); Thu, 12 Feb 2009 12:57:31 -0500 Received: from g1t0026.austin.hp.com ([15.216.28.33]:45508 "EHLO g1t0026.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750774AbZBLR5a (ORCPT ); Thu, 12 Feb 2009 12:57:30 -0500 Date: Thu, 12 Feb 2009 10:56:59 -0700 From: Alex Chiang To: Greg KH Cc: Kay Sievers , arjan@linux.intel.com, alex.williamson@hp.com, linux-kernel Subject: Re: [PATCH] sysfs: sysfs_add_one tells you _where_ the duplicate file is Message-ID: <20090212175659.GC20654@ldl.fc.hp.com> Mail-Followup-To: Alex Chiang , Greg KH , Kay Sievers , arjan@linux.intel.com, alex.williamson@hp.com, linux-kernel References: <20090211202601.GC3402@ldl.fc.hp.com> <20090211223903.GA21100@suse.de> <20090212025655.GA6916@ldl.fc.hp.com> <20090212030227.GA4859@suse.de> <20090212070210.GB6916@ldl.fc.hp.com> <20090212160257.GA18786@suse.de> <20090212173835.GB20654@ldl.fc.hp.com> <20090212174122.GA22301@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090212174122.GA22301@suse.de> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Greg KH : > On Thu, Feb 12, 2009 at 10:38:35AM -0700, Alex Chiang wrote: > > + if (ret == -EEXIST) { > > + char *path = kzalloc(PATH_MAX, GFP_KERNEL); > > You forgot to check the return value of kzalloc(). > > Another try? > > 8th time's a charm? :) Yeah, you're too fast for me. I thought about that just as I walked away from my desk. ;) What are we on, v6? From: Alex Chiang sysfs: sysfs_add_one WARNs with full path to duplicate filename As a debugging aid, it can be useful to know the full path to a duplicate file being created in sysfs. We now will display warnings such as: sysfs: cannot create duplicate filename '/foo' when attempting to create multiple files named 'foo' in the sysfs root, or: sysfs: cannot create duplicate filename '/bus/pci/slots/5/foo' when attempting to create multiple files named 'foo' under a given directory in sysfs. The path displayed is always a relative path to sysfs_root. The leading '/' in the path name refers to the sysfs_root mount point, and should not be confused with the "real" '/'. Thanks to Alex Williamson for essentially writing sysfs_pathname. Cc: Alex Williamson Signed-off-by: Alex Chiang --- dir.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) --- diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index 82d3b79..f13d852 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -434,6 +434,26 @@ int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) } /** + * sysfs_pathname - return full path to sysfs dirent + * @sd: sysfs_dirent whose path we want + * @path: caller allocated buffer + * + * Gives the name "/" to the sysfs_root entry; any path returned + * is relative to wherever sysfs is mounted. + * + * XXX: does no error checking on @path size + */ +static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) +{ + if (sd->s_parent) { + sysfs_pathname(sd->s_parent, path); + strcat(path, "/"); + } + strcat(path, sd->s_name); + return path; +} + +/** * sysfs_add_one - add sysfs_dirent to parent * @acxt: addrm context to use * @sd: sysfs_dirent to be added @@ -458,8 +478,16 @@ int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) int ret; ret = __sysfs_add_one(acxt, sd); - WARN(ret == -EEXIST, KERN_WARNING "sysfs: duplicate filename '%s' " - "can not be created\n", sd->s_name); + if (ret == -EEXIST) { + char *path = kzalloc(PATH_MAX, GFP_KERNEL); + WARN(1, KERN_WARNING + "sysfs: cannot create duplicate filename '%s'\n", + (path == NULL) ? sd->s_name : + strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"), + sd->s_name)); + kfree(path); + } + return ret; }