Re: [PATCH V9.1] xfs: Directory's data fork extent counter can never overflow

Dave Chinner
2022-04-11T01:33:46Z

On Sat, Apr 09, 2022 at 07:17:21PM +0530, Chandan Babu R wrote:
> The maximum file size that can be represented by the data fork extent counter
> in the worst case occurs when all extents are 1 block in length and each block
> is 1KB in size.
>
> With XFS_MAX_EXTCNT_DATA_FORK_SMALL representing maximum extent count and with
> 1KB sized blocks, a file can reach upto,
> (2^31) * 1KB = 2TB
>
> This is much larger than the theoretical maximum size of a directory
> i.e. XFS_DIR2_SPACE_SIZE * 3 = ~96GB.
>
> Since a directory's inode can never overflow its data fork extent counter,
> this commit removes all the overflow checks associated with
> it. xfs_dinode_verify() now performs a rough check to verify if a diretory's
> data fork is larger than 96GB.
>
> Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>

Looks good now.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
--
Dave Chinner
david@fromorbit.com