Re: [PATCH] fsstack: fsstack_copy_inode_size locking

[Erez Zadok]

In message <20080701070350.GA22914@xxxxxxxxxxxxx>, Christoph Hellwig writes:
> On Mon, Jun 30, 2008 at 04:49:01PM -0500, Michael Halcrow wrote:
> > eCryptfs depends on the results of i_size_read() on the lower inode
> > when it needs to interpolate the filesize when the metadata is stored
> > in the lower file's xattr region.
> 
> please use vfs_getattr to get the size in thst case.

So, Christoph, is using vfs_getattr() the preferred choice for stackable
file systems in general to get the lower inode size?

If so, the Hugh's fsstack_copy_inode_size patch will have to be updated: and
we'll probably have to change the names of the src/dst parameters to
lower/upper, possibly watch out for whether "src" was the lower or upper
inode, and be careful about locking semantics when calling vfs_getattr.

Who'd have thought that a concept as simple as
      dst->i_size = src->i_size
could turn out to be so hairy... 1/2 a :-)

Thanks,
Erez.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/