Re: [PATCH] btrfs: use iosize while reading compressed pages

[Josef Bacik <josef@toxicpanda.com>]

On 9/15/20 11:41 AM, Goldwyn Rodrigues wrote:
> While using compression, a submitted bio is mapped with a compressed bio
> which performs the read from disk, decompresses and returns uncompressed
> data to original bio. The original bio must reflect the uncompressed
> size (iosize) of the I/O to be performed, or else the page just gets the
> decompressed I/O length of data (disk_io_size). The compressed bio
> checks the extent map and get the correct length while performing the
> I/O from disk.
> 
> This came up in subpage work when only compressed length of the original
> bio was filled in the page. This worked correctly for pagesize ==
> sectorsize because both compressed and uncompressed data are at pagesize
> boundaries, and would end up filling the requested page.
> 
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef