On Thu 22-04-10 12:08:55, David Woodhouse wrote: > On Wed, 2010-04-21 at 18:21 +0300, Kirill A. Shutemov wrote: > > + /* > > + * We cannot modify file->f_mapping->backing_dev_info directly, > > + * because it will corrupt backing device for inode, since > > + * inode->i_mapping is equal to file->f_mapping. So we have to > > + * copy f_mapping first. > > + */ > > + file->f_mapping = kmalloc(sizeof(*file->f_mapping), GFP_KERNEL); > > + memcpy(file->f_mapping, inode->i_mapping, > > + sizeof(*file->f_mapping)); > > file->f_mapping->backing_dev_info = mtd->backing_dev_info; > > + } > > Ick. What about the rest of file->f_mapping? That'll still be inherited. > > Jan pointed at drivers/char/raw.c as an example, but that doesn't do > anything as ugly as this -- that sets file->f_mapping to point at > bdev->bd_inode->i_mapping instead. > > I suspect we should do something similar -- have an inode for the MTD > device, with a valid i_data of its own. Yes, that's what I meant by my suggestion... Sorry if I wasn't clear enough. Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
