On Fri 06-05-16 15:53:10, Vishal Verma wrote:
> +static bool dax_range_is_aligned(struct block_device *bdev,
> + struct blk_dax_ctl *dax, unsigned int offset,
> + unsigned int length)
> +{
> + unsigned short sector_size = bdev_logical_block_size(bdev);
> +
> + if (((u64)dax->addr + offset) % sector_size)
> + return false;
> + if (length % sector_size)
> + return false;
sector_size should better be a power of two so you can save some cycles by
using & instead of %.
> @@ -1240,11 +1254,17 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length,
> .size = PAGE_SIZE,
> };
>
> - 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 / bdev_logical_block_size(bdev),
> + GFP_NOFS, true);
This is actually wrong. blkdev_issue_zeroout() expects length to be simply
in units of 512-bytes. So you need length >> 9 here.
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
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