linux-kernel - Re: [PATCH v3 11/13] bcachefs: fiemap: return correct extent physical length

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Message-ID: <Zg2LG1_2-ac1GlsG@bfoster>
Date: Wed, 3 Apr 2024 13:00:11 -0400
From: Brian Foster <bfoster@...hat.com>
To: Sweet Tea Dorminy <sweettea-kernel@...miny.me>
Cc: Jonathan Corbet <corbet@....net>,
	Kent Overstreet <kent.overstreet@...ux.dev>,
	Chris Mason <clm@...com>, Josef Bacik <josef@...icpanda.com>,
	David Sterba <dsterba@...e.com>, Jaegeuk Kim <jaegeuk@...nel.org>,
	Chao Yu <chao@...nel.org>, Alexander Viro <viro@...iv.linux.org.uk>,
	Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
	Mickaël Salaün <mic@...ikod.net>,
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-bcachefs@...r.kernel.org, linux-btrfs@...r.kernel.org,
	linux-f2fs-devel@...ts.sourceforge.net,
	linux-fsdevel@...r.kernel.org, kernel-team@...a.com
Subject: Re: [PATCH v3 11/13] bcachefs: fiemap: return correct extent
 physical length

On Wed, Apr 03, 2024 at 03:22:52AM -0400, Sweet Tea Dorminy wrote:
> Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@...miny.me>
> ---
>  fs/bcachefs/fs.c | 18 ++++++++++++------
>  1 file changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
> index f830578a9cd1..d2793bae842d 100644
> --- a/fs/bcachefs/fs.c
> +++ b/fs/bcachefs/fs.c
> @@ -913,15 +913,17 @@ static int bch2_fill_extent(struct bch_fs *c,
>  			flags |= FIEMAP_EXTENT_SHARED;
>  
>  		bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
> -			int flags2 = 0;
> +			int flags2 = FIEMAP_EXTENT_HAS_PHYS_LEN;
> +			u64 phys_len = k.k->size << 9;
>  			u64 offset = p.ptr.offset;
>  
>  			if (p.ptr.unwritten)
>  				flags2 |= FIEMAP_EXTENT_UNWRITTEN;
>  
> -			if (p.crc.compression_type)
> +			if (p.crc.compression_type) {
>  				flags2 |= FIEMAP_EXTENT_ENCODED;
> -			else
> +				phys_len = p.crc.compressed_size << 9;
> +			} else
>  				offset += p.crc.offset;
>  
>  			if ((offset & (block_sectors(c) - 1)) ||
> @@ -931,7 +933,7 @@ static int bch2_fill_extent(struct bch_fs *c,
>  			ret = fiemap_fill_next_extent(info,
>  						bkey_start_offset(k.k) << 9,
>  						offset << 9,
> -						k.k->size << 9, 0,
> +						k.k->size << 9, phys_len,
>  						flags|flags2);
>  			if (ret)
>  				return ret;
> @@ -941,14 +943,18 @@ static int bch2_fill_extent(struct bch_fs *c,
>  	} else if (bkey_extent_is_inline_data(k.k)) {
>  		return fiemap_fill_next_extent(info,
>  					       bkey_start_offset(k.k) << 9,
> -					       0, k.k->size << 9, 0,
> +					       0, k.k->size << 9,
> +					       bkey_inline_data_bytes(k.k),

Question for Kent perhaps, but what's the functional difference between
bkey_inline_data_bytes() and k->size in this particular case?

FWIW that and the other couple nitty questions aside, this all LGTM.
Thanks.

Brian

>  					       flags|
> +					       FIEMAP_EXTENT_HAS_PHYS_LEN|
>  					       FIEMAP_EXTENT_DATA_INLINE);
>  	} else if (k.k->type == KEY_TYPE_reservation) {
>  		return fiemap_fill_next_extent(info,
>  					       bkey_start_offset(k.k) << 9,
> -					       0, k.k->size << 9, 0,
> +					       0, k.k->size << 9,
> +					       k.k->size << 9,
>  					       flags|
> +					       FIEMAP_EXTENT_HAS_PHYS_LEN|
>  					       FIEMAP_EXTENT_DELALLOC|
>  					       FIEMAP_EXTENT_UNWRITTEN);
>  	} else {
> -- 
> 2.43.0
> 
>