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    SubjectRe: [RFC Aufs2 #2 21/28] aufs sysfs entries
    On Tue, Mar 17, 2009 at 12:26:42PM +0900, wrote:
    > Thank you very much for reviewing.
    > Greg KH:
    > > > +/* todo: file size may exceed PAGE_SIZE */
    > > > +ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
    > > > + char *buf)
    > >
    > > NO IT CAN NOT!!!!
    > >
    > > You are using sysfs wrong if you even think you are getting close to
    > > PAGE_SIZE.
    > The main reason I left a comment about PAGE_SIZE is that some of aufs
    > entry under sysfs contain the file path.

    Which should be MAX_PATH, right? Is that ever bigger than PAGE_SIZE?

    > And I don't think it is a good idea to create a symlink since the path
    > may be changed as a result of users operation.
    > I left it as "todo" because such long path is rare.
    > If you have an idea to show users any file path which may be changed
    > dynamically, please let me know. At the beginning I have tried procfs,
    > but I was told that newer module should use sysfs instead of procfs. If
    > sysfs doesn't suit a path, what should I use? Debugfs?

    What specifically are you trying to show here?

    > > Please, use debugfs for this. sysfs is a "one value per file" type
    > > filesystem. You should never be using the seqfile interface for a sysfs
    > > file, that's a sure sign something is wrong in your design.
    > >
    > > I think I'll stop reading now :(
    > I will change some entries which doesn't contain a file path (or make
    > them not to have have) and post again. So please don't stop reading.

    Please document your sysfs entries, and I'll be glad to review it again.


    greg k-h

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