Messages in this thread | | | Date | Tue, 14 Jan 2014 10:21:35 -0800 | From | Greg KH <> | Subject | Re: [RFC] sysfs_rename_link() and its usage |
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On Tue, Jan 14, 2014 at 06:17:40PM +0100, Veaceslav Falico wrote: > Hi, > > I'm hitting a strange issue and/or I'm completely lost in sysfs internals. > > Consider having two net_device *a, *b; which are registered normally. > Now, to create a link from /sys/class/net/a->name/linkname to b, one should > use: > > sysfs_create_link(&(a->dev.kobj), &(b->dev.kobj), linkname); > > To remove it, even simpler: > > sysfs_remove_link(&(a->dev.kobj), linkname); > > This works like a charm. However, if I want to use (obviously, with the > symlink present): > > sysfs_rename_link(&(a->dev.kobj), &(b->dev.kobj), oldname, newname);
You forgot the namespace option to this call, what kernel version are you using here?
> this fails with: > > "sysfs: ns invalid in 'a->name' for 'oldname'"
Looks like the namespace for this link isn't valid.
> in > > 608 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, > ... > 615 if (!!sysfs_ns_type(parent_sd) != !!ns) { > 616 WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", > 617 sysfs_ns_type(parent_sd) ? "required" : "invalid", > 618 parent_sd->s_name, name); > 619 return NULL; > 620 } > > Code path: > warn_slowpath_fmt+0x46/0x50 > sysfs_get_dirent_ns+0x30/0x80 > sysfs_find_dirent+0x84/0x110 > sysfs_get_dirent_ns+0x3e/0x80 > sysfs_rename_link_ns+0x54/0xd0 > > I have no idea what this code means. Is there any reason for it to > fail (i.e. am I doing something wrong?) or I've hit a bug?
What exactly are you trying to do here? Care to provide a pointer to your code somewhere?
> I've tested the only user of it (bridge) - and it works fine, however it's > not using its own net_device's kobject but rather its own dir.
The driver core also uses this function, and it works there, so I'd blame your code :)
thanks,
greg k-h
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