Re: sysfs: spit a warning to users when they try to create a duplicate sysfs file

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

Greg KH wrote:
> We want to let people know when we create a duplicate sysfs file, as
> they need to fix up their code.
> 
> 
> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
> 
> ---
>  fs/sysfs/dir.c |    6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> --- a/fs/sysfs/dir.c
> +++ b/fs/sysfs/dir.c
> @@ -428,8 +428,12 @@ void sysfs_addrm_start(struct sysfs_addr
>   */
>  int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
>  {
> -	if (sysfs_find_dirent(acxt->parent_sd, sd->s_name))
> +	if (sysfs_find_dirent(acxt->parent_sd, sd->s_name)) {
> +		printk(KERN_WARNING, "sysfs: duplicate filename '%s' "
> +		       "can not be created\n", sd->s_name);
> +		WARN_ON(1);
>  		return -EEXIST;
> +	}
>  
>  	sd->s_parent = sysfs_get(acxt->parent_sd);
>  

As a side story:

I've got code which has checks for device_create_file != 0 but keeps
quiet if it got -EEXIST.  I rewrote it now so that it does not rely on
the driver core to skip over already existing files.  Doing this
revealed a group of old refcounting bugs. :-)  Thanks,
-- 
Stefan Richter
-=====-=-=== =--= -====
http://arcgraph.de/sr/