Re: [PATCH 0/2]Define ext3 in-kernel filesystem block types and extend ext3 filesystem limit from 8TB to 16TB

[Andrew Morton <akpm@osdl.org>]

Mingming Cao <cmm@us.ibm.com> wrote:
>
> Some of the in-kernel ext3 block variable type are treated as signed 4 bytes
>  int type, thus limited ext3 filesystem to 8TB (4kblock size based). While
>  trying to fix them, it seems quite confusing in the ext3 code where some
>  blocks are filesystem-wide blocks, some are group relative offsets that need
>  to be signed value (as -1 has special meaning). So it seem saner to define two
>  types of physical blocks: one is filesystem wide blocks, another is
>  group-relative blocks.  The following patches clarify these two types of
>  blocks in the ext3 code, and fix the type bugs which limit current 32 bit ext3
>  filesystem limit to 8TB.
> 
>  With this series of patches and the percpu counter data type changes in the mm
>  tree, we are able to extend exts filesystem limit to 16TB.

Did you look at the `gcc -W' output before and after these patches are
applied?  That would have found the bug which the previous version
of these patches introduced.

We already get a pile of `warning: comparison between signed and unsigned'
warnings which should be checked, too..