On Fri, Nov 8, 2024 at 4:13 PM Joanne Koong <joannelkoong@xxxxxxxxx> wrote:
>
> Add support for folios larger than one page size for non-writeback
I'll change this naming from "non-writeback" to "writethrough"
> writes.
>
> Signed-off-by: Joanne Koong <joannelkoong@xxxxxxxxx>
> ---
> fs/fuse/file.c | 29 ++++++++++++++++++-----------
> 1 file changed, 18 insertions(+), 11 deletions(-)
>
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index a89fdc55a40b..6ee23ab9b7f2 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -1146,19 +1146,15 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
> num = min(num, max_pages << PAGE_SHIFT);
>
> ap->args.in_pages = true;
> - ap->descs[0].offset = offset;
>
> while (num) {
> size_t tmp;
> struct folio *folio;
> pgoff_t index = pos >> PAGE_SHIFT;
> - unsigned int bytes = min(PAGE_SIZE - offset, num);
> -
> - again:
> - err = -EFAULT;
> - if (fault_in_iov_iter_readable(ii, bytes))
> - break;
> + unsigned int bytes;
> + unsigned int folio_offset;
>
> + again:
> folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
> mapping_gfp_mask(mapping));
This __filemap_get_folio() call (and the one in fuse_write_begin() as
well) needs to also set the order on the fgf flag to enable large
folios, else all folios returned will be order 0.
I'll fix this in v2.
> if (IS_ERR(folio)) {
> @@ -1166,10 +1162,20 @@ static ssize_t fuse_fill_write_pages(struct fuse_io_args *ia,
> break;
> }
>
> + folio_offset = ((index - folio->index) << PAGE_SHIFT) + offset;
> + bytes = min(folio_size(folio) - folio_offset, num);
> +
> + err = -EFAULT;
> + if (fault_in_iov_iter_readable(ii, bytes)) {
> + folio_unlock(folio);
> + folio_put(folio);
> + break;
> + }
> +
> if (mapping_writably_mapped(mapping))
> flush_dcache_folio(folio);
>
> - tmp = copy_folio_from_iter_atomic(folio, offset, bytes, ii);
> + tmp = copy_folio_from_iter_atomic(folio, folio_offset, bytes, ii);
> flush_dcache_folio(folio);
>
> if (!tmp) {
> @@ -1180,6 +1186,7 @@ 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 +1194,11 @@ 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);
>
> if (folio_test_uptodate(folio)) {
> --
> 2.43.5
>
