Re: swich attribute open() to simple stat()

[Greg KH <greg@kroah.com>]

On Fri, Oct 15, 2004 at 07:36:19PM +0200, Kay Sievers wrote:
> Here we switch to a simple stat() to recognize the file creation. This
> will make it possible to wait for files, which are unreadable.
> 
> I've switched the timout back to 5 seconds cause the our /class/vc errors
> seems like a bug in the vc layer not a sysfs delay.
> 
> Thanks,
> Kay

> === wait_for_sysfs.c 1.18 vs edited ==> --- 1.18/wait_for_sysfs.c	2004-10-14 16:14:00 +02:00
> +++ edited/wait_for_sysfs.c	2004-10-15 19:32:38 +02:00
> @@ -47,7 +47,7 @@ void log_message(int level, const char *
>  }
>  #endif
>  
> -#define WAIT_MAX_SECONDS		10
> +#define WAIT_MAX_SECONDS		5
>  #define WAIT_LOOP_PER_SECOND		20
>  
>  /* wait for specific file to show up, normally the "dev"-file */
> @@ -60,7 +60,7 @@ static int wait_for_class_device_attribu
>  		{ .subsystem = "net",		.file = "ifindex" },
>  		{ .subsystem = "scsi_host",	.file = "unique_id" },
>  		{ .subsystem = "scsi_device",	.file = NULL },
> -		{ .subsystem = "pcmcia_socket",	.file = NULL }, /* all files are unreadable in empty slot :( */
> +		{ .subsystem = "pcmcia_socket",	.file = "card_type" },
>  		{ .subsystem = "usb_host",	.file = NULL },
>  		{ .subsystem = "bluetooth",	.file = "address" },
>  		{ .subsystem = "firmware",	.file = "data" },
> @@ -86,11 +86,14 @@ static int wait_for_class_device_attribu
>  			break;
>  		}
>  	}
> -	dbg("looking at class '%s' for specific file '%s'", class_dev->classname, file);
> +
> +	dbg("looking at class '%s' for specific file '%s'", class_dev->classname, class_dev->path);
>  
>  	loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
>  	while (--loop) {
> -		if (sysfs_get_classdev_attr(class_dev, file) != NULL) {
> +		struct stat stats;
> +
> +		if (stat(class_dev->path, &stats) = 0) {

Wait, this patch stops us from looking for "file" which had been set to
the file we wanted to look at, right?  Now we are just verifying that
the sysfs _directory_ for the class device is present.

While this is a good check (and we should do this to verify that the
device hasn't gone away, like in the vcs issue), I don't think this is
what you wanted to do, right?

thanks,

greg k-h


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