Re: [PATCH v6 4/5] dax: for truncate/hole-punch, do zeroing through the driver if possible

Verma, Vishal L
2016-05-11T18:39:59Z

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 834 bytes --]

On Tue, 2016-05-10 at 12:49 -0600, Vishal Verma wrote:
>Â
...

> @@ -1240,11 +1254,16 @@ int dax_zero_page_range(struct inode *inode,
> loff_t from, unsigned length,
> Â  .size = PAGE_SIZE,
> Â  };
> Â
> - if (dax_map_atomic(bdev, &dax) < 0)
> - return PTR_ERR(dax.addr);
> - clear_pmem(dax.addr + offset, length);
> - wmb_pmem();
> - dax_unmap_atomic(bdev, &dax);
> + if (dax_range_is_aligned(bdev, &dax, offset, length))
> + return blkdev_issue_zeroout(bdev, dax.sector,
> + length >> 9, GFP_NOFS, true);

Found another bug here while testing. The zeroout needs to be done for
sector + (offset >> 9). The above just zeroed out the first sector of
the page irrespective of offset, which is wrong.N‹§²æìr¸›zÇ§u©ž²Æ {\b­†éì¹»\x1c®&Þ–)îÆi¢žØ^n‡r¶‰šŽŠÝ¢j$½§$¢¸\x05¢¹¨­è§~Š'.)îÄÃ,yèm¶ŸÿÃ\f%Š{±šj+ƒðèž×¦j)Z†·Ÿ