On Sun, Sep 22, 2013 at 04:25:15PM +0800, Jeff Liu wrote:
> From: Jie Liu <jeff.liu@xxxxxxxxxx>
>
> At xfs_iext_realloc_direct(), the new_size is changed by adding
> if_bytes if originally the extent records are stored at the inline
> extent buffer, and we have to switch from it to a direct extent
> list for those new allocated extents, this is wrong. e.g,
>
> Create a file with three extents which was showing as following,
>
> xfs_io -f -c "truncate 100m" /xfs/testme
>
> for i in $(seq 0 5 10); do
> offset=$(($i * $((1 << 20))))
> xfs_io -c "pwrite $offset 1m" /xfs/testme
> done
>
> Inline
> ------
> irec: if_bytes bytes_diff new_size
> 1st 0 16 16
> 2nd 16 16 32
>
> Switching
> --------- rnew_size
> 3rd 32 16 48 + 32 = 80 roundup=128
>
> In this case, the desired value of new_size should be 48, and then
> it will be roundup to 64 and be assigned to rnew_size.
>
> However, this issue has been covered by resetting the if_bytes to
> the new_size which is calculated at the begnning of xfs_iext_add()
> before leaving out this function, and in turn make the rnew_size
> correctly again. Hence, this can not be detected via xfstestes.
>
> This patch fix above problem and revise the new_size comments at
> xfs_iext_realloc_direct() to make it more readable. Also, fix the
> comments while switching from the inline extent buffer to a direct
> extent list to reflect this change.
>
> Signed-off-by: Jie Liu <jeff.liu@xxxxxxxxxx>
Applied.
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