Re: mount failed after xfs_growfs beyond 16 TB

[Timothy Shimmin <tes@xxxxxxx>]

Good idea, Eric.
I've created a pv.
I noticed this was taken from xfs_mount_validate_sb() for the dblocks test.
I guess it would be nice to abstract this test in a macro for use in multiple 
places.

Cheers,
Tim.

--On 3 November 2006 8:54:43 AM -0600 Eric Sandeen <sandeen@xxxxxxxxxxx> wrote:

> David Chinner wrote:
> > On Thu, Nov 02, 2006 at 06:26:08PM +0100, Christian Guggenberger wrote:
> > > Hi,
> > >
> > > a colleague recently tried to grow a 16 TB filesystem (x86, 32bit) on
> > > top of lvm2 to 17TB. (I am not even sure if that's supposed work with
> > > linux-2.6, 32bit)
> >
> > Not supported - any metadata access past 16TB will wrap the 32 bit page 
> > cache
> > index for the metadata address space and you'll corrupt the filesystem.
>
>
> Ohhhh right.  I've been in x86_64 land for too long, sorry for the earlier 
> false assertion....  :(
>
> xfs guys, if it's not there already (and I don't see it from a quick look..) 
> growfs -really-
> should refuse (in the kernel) to grow a filesystem past 16T on a 32-bit 
> machine, just as we
> refuse to mount one.  something like this in xfs_growfs_data_private:
>
> # if XFS_BIG_BLKNOS     /* Limited by ULONG_MAX of page cache index */
>          if (unlikely(
>              (nb >> (PAGE_SHIFT - sbp->sb_blocklog)) > ULONG_MAX) {
> # else                  /* Limited by UINT_MAX of sectors */
>          if (unlikely(
>              (nb << (sbp->sb_blocklog - BBSHIFT)) > UINT_MAX) {
> # endif
>                  cmn_err(CE_WARN,
>                          "new filesystem size too large for this system.");
>                  return XFS_ERROR(E2BIG);
>          }
>
> and something similar in xfs_growfs_rt ?
>
> -Eric