2024-04-03 16:58:48

by Brian Foster

[permalink] [raw]
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 <[email protected]>
> ---
> 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
>
>



2024-04-03 18:15:44

by Kent Overstreet

[permalink] [raw]
Subject: Re: [PATCH v3 11/13] bcachefs: fiemap: return correct extent physical length

On Wed, Apr 03, 2024 at 01:00:11PM -0400, Brian Foster wrote:
> On Wed, Apr 03, 2024 at 03:22:52AM -0400, Sweet Tea Dorminy wrote:
> > Signed-off-by: Sweet Tea Dorminy <[email protected]>
> > ---
> > 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?

Not much - k->size will correspond to the size of the original write -
that is, the writeback write from the pagecache. inline_data_bytes is
the amount of data that wasn't zeroes.

So inline_data_bytes is probably the right thing to use here.