Re: partition sysfs OOPS in current GIT

[Greg KH <gregkh@suse.de>]

On Wed, Feb 06, 2008 at 11:11:44PM -0800, David Miller wrote:
> From: Greg KH <gregkh@suse.de>
> Date: Wed, 6 Feb 2008 23:00:44 -0800
> 
> > On Wed, Feb 06, 2008 at 10:39:44PM -0800, David Miller wrote:
> > > From: Greg KH <gregkh@suse.de>
> > > Date: Wed, 6 Feb 2008 22:42:10 -0800
> > > 
> > > > On Wed, Feb 06, 2008 at 10:05:44PM -0800, David Miller wrote:
> > > > > I found the problem, it's the "whole_disk" partition attribute.
> > > > 
> > > > I don't understand that code at all, on 2.6.24, what does reading that
> > > > file give you?  At first glance, I don't see how that file would spit
> > > > out anything and not give you the same kind of oops.
> > > > 
> > > > you are in a maze of kobject pointers, all alike...
> > > 
> > > It's supposed to just exist, and be an empty zero length file.
> > > That's why it's given no ->show method pointer.
> > > 
> > > It's existence just means that the partition is a "whole disk"
> > > partition type.
> > 
> > Can you try this patch to see if it solves the oops, and that the file
> > is still there and works properly?
> 
> It doesn't crash, but the file returns -EIO instead of zero when read.

How about this attempt?

thanks for your patience,

greg "Kay owes me a beer" k-h

---
 fs/partitions/check.c |   17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -319,6 +319,14 @@ void delete_partition(struct gendisk *di
 	put_device(&p->dev);
 }
 
+static ssize_t whole_disk_show(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	return 0;
+}
+static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
+		   whole_disk_show, NULL);
+
 void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
 {
 	struct hd_struct *p;
@@ -352,13 +360,8 @@ void add_partition(struct gendisk *disk,
 	device_add(&p->dev);
 	partition_sysfs_add_subdir(p);
 	p->dev.uevent_suppress = 0;
-	if (flags & ADDPART_FLAG_WHOLEDISK) {
-		static struct attribute addpartattr = {
-			.name = "whole_disk",
-			.mode = S_IRUSR | S_IRGRP | S_IROTH,
-		};
-		err = sysfs_create_file(&p->dev.kobj, &addpartattr);
-	}
+	if (flags & ADDPART_FLAG_WHOLEDISK)
+		err = device_create_file(&p->dev, &dev_attr_whole_disk);
 
 	/* suppress uevent if the disk supresses it */
 	if (!disk->dev.uevent_suppress)