Re: [PATCH 0/2] btrfs fiemap related BUG fix.

[David Sterba <dsterba@suse.cz>]

On Wed, Mar 07, 2018 at 04:20:17PM +0800, robbieko wrote:
> From: Robbie Ko <robbieko@synology.com>
> 
> This patchset intends to fix btrfs fiemap related bug.
> 
> The fiemap has the following problems:
> 
> 1) Wrong extent count when fm_extent_count is zero.
> 
> 
> 2) SHARED bit is not correct
> I have two ideas, but I do not know which one is the best.
> 
> Like:
>  # dd if=/dev/zero bs=16K count=2 oflag=dsync of=/mnt/btrfs/file
>  # xfs_io -c "fiemap -v" /mnt/btrfs/file
>      /mnt/btrfs/file:
>      EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
>        0: [0..63]:         4241424..4241487    64   0x1
>  # cloner -s $((16*1024)) /mnt/btrfs/file /mnt/btrfs/file_clone
> 
> 1. When any extent is shared in extent map, the entire extent map is shared
>  # xfs_io -c "fiemap -v" /mnt/btrfs/file
>      /mnt/btrfs/file:
>      EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
>        0: [0..63]:         4241424..4241487   64  0x2001
> 
> 2. Split into different extent
>  # xfs_io -c "fiemap -v" /mnt/btrfs/file
>      /mnt/btrfs/file:
>      EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
>        0: [0..31]:         4241424..4241455   32  0x0
>        1: [32..63]:        4241456..4241487   32  0x2001
> 
> Robbie Ko (2):
>   Btrfs: fiemap: pass correct bytenr when fm_extent_count is zero
>   Btrfs: fix fiemap extent SHARED flag error with range clone.

There were a lot of comments, I'm not sure I have a clear picture of
what and how is addressed. Can you please update the patches and resend?
Thanks.