[PATCH]fs/jffs2/wbuf.c: add compatibility support for OOB data block

[Ferenc Havasi]

Hi Artem,

> Ok, to keep you busy with some technical stuff also, here is a remark.
>
> >+        if (je32_to_cpu(sm->magic) == JFFS2_SUM_MAGIC ) {
> >+
> >+            if(je32_to_cpu(sm->erase_size) == c->sector_size) {
> >+                err = 
> >jffs2_sum_scan_sumnode(c,jeb,je32_to_cpu(sm->offset),&pseudo_random);
> >+
> >+                if (err) {
> >+                    kfree(sm);
> >+                    return err;
> >+                }
> >+            }
> >+            printk(KERN_WARNING "FS erase_block_size != JFFS2 
> erase_block_size => skipping summary information\n");
> >+        }
>
> if(je32_to_cpu(sm->erase_size) == c->sector_size) { ...
>
> AFAIU, you're protecting against the situation when the size of the 
> JFFS2 virtual eraseblock is changed.

No. The task of this condition is to make sure that the summary was 
generated correctly. If the summary is generated by the filesystem, it 
will be always good, but you are also able to generate summary with the 
userspace tool 'sumtool'. If we do not recognise this mistake that can 
cause big problems and make the user confused.

Bye,
Ferenc