Re: [PATCH] ovl: support stacked SEEK_HOLE/SEEK_DATA

[Eddie Horng <eddiehorng.tw@gmail.com>]

> > > > OK. What about Eddie's question:
> > > > If realinode is nested overlay inode, then realinode->i_sb->s_maxbytes
> > > > will not reflect the "real" inode's maxbytes.
> > > > Not to mention other crazy things that filesystems may do for SET/CUR/END.
> > > > Take ext4_llseek() for example, for the less common case (ext3 format inode)
> > > > the value of inode->i_sb->s_maxbytes is not used as maxbytes, but a smaller
> > > > value.
> > > >

Hi Amir,
Thanks your detail information and the patch.
I ran into this issue by using a proprietary stacked file system as lower
and the file system does not initial it's s_maxbytes, therefore
caused file larger than 2GB fails lseek. A quick workaround is to set the fs
s_maxbytes to MAX_LFS_FILESIZE, but like you said, for certain cases this might
be a problem.
I have verified this patch with same configuration and the lower inode
f_op->llseek
does get invoked, looks like enough to resolve my particular case.

thanks,
Eddie