On 4/26/25 02:08, Joanne Koong wrote:
> Add support for folios larger than one page size for writethrough
> writes.
>
> Signed-off-by: Joanne Koong <joannelkoong@xxxxxxxxx>
> Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/fuse/file.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index edc86485065e..e44b6d26c1c6 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -1146,7 +1146,8 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
> size_t tmp;
> struct folio *folio;
> pgoff_t index = pos >> PAGE_SHIFT;
> - unsigned bytes = min(PAGE_SIZE - offset, num);
> + unsigned int bytes;
> + unsigned int folio_offset;
>
> again:
> folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
> @@ -1159,7 +1160,10 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
> if (mapping_writably_mapped(mapping))
> flush_dcache_folio(folio);
>
> - tmp = copy_folio_from_iter_atomic(folio, offset, bytes, ii);
> + folio_offset = ((index - folio->index) << PAGE_SHIFT) + offset;
> + bytes = min(folio_size(folio) - folio_offset, num);
> +
> + tmp = copy_folio_from_iter_atomic(folio, folio_offset, bytes, ii);
> flush_dcache_folio(folio);
>
> if (!tmp) {f
> @@ -1180,6 +1184,7 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
>
> err = 0;
> ap->folios[ap->num_folios] = folio;
> + ap->descs[ap->num_folios].offset = folio_offset;
> ap->descs[ap->num_folios].length = tmp;
> ap->num_folios++;
>
> @@ -1187,11 +1192,11 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
> pos += tmp;
> num -= tmp;
> offset += tmp;
> - if (offset == PAGE_SIZE)
> + if (offset == folio_size(folio))
> offset = 0;
>
> - /* If we copied full page, mark it uptodate */
> - if (tmp == PAGE_SIZE)
> + /* If we copied full folio, mark it uptodate */
> + if (tmp == folio_size(folio))
> folio_mark_uptodate(folio);
Here am I confused. I think tmp can be a subpart of the folio, let's say
the folio is 2MB and somehow the again loop would iterate through the
folio in smaller steps. So the folio would be entirely written out, but
tmp might not be folio_size? Doesn't this need to sum up tmp for per
folio and then use that value? And I actually wonder if we could use
the above "(offset == folio_size(folio)" as well. At least if the
initial offset for a folio is 0 it should work.
Thanks,
Bernd
>
> if (folio_test_uptodate(folio)) {
