On Fri, Nov 08, 2024 at 04:12:47PM -0800, Joanne Koong wrote:
> Currently, all folios associated with fuse are one page size. As part of
> the work to enable large folios, this commit adds support for copying
> to/from folios larger than one page size.
>
> Signed-off-by: Joanne Koong <joannelkoong@xxxxxxxxx>
> ---
> fs/fuse/dev.c | 89 +++++++++++++++++++++++----------------------------
> 1 file changed, 40 insertions(+), 49 deletions(-)
>
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index 29fc61a072ba..9914cc1243f4 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -703,7 +703,7 @@ struct fuse_copy_state {
> struct page *pg;
> unsigned len;
> unsigned offset;
> - unsigned move_pages:1;
> + unsigned move_folios:1;
> };
>
> static void fuse_copy_init(struct fuse_copy_state *cs, int write,
> @@ -836,10 +836,10 @@ static int fuse_check_folio(struct folio *folio)
> return 0;
> }
>
> -static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
> +static int fuse_try_move_folio(struct fuse_copy_state *cs, struct folio **foliop)
> {
> int err;
> - struct folio *oldfolio = page_folio(*pagep);
> + struct folio *oldfolio = *foliop;
> struct folio *newfolio;
> struct pipe_buffer *buf = cs->pipebufs;
>
> @@ -860,7 +860,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
> cs->pipebufs++;
> cs->nr_segs--;
>
> - if (cs->len != PAGE_SIZE)
> + if (cs->len != folio_size(oldfolio))
> goto out_fallback;
>
> if (!pipe_buf_try_steal(cs->pipe, buf))
> @@ -906,7 +906,7 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
> if (test_bit(FR_ABORTED, &cs->req->flags))
> err = -ENOENT;
> else
> - *pagep = &newfolio->page;
> + *foliop = newfolio;
> spin_unlock(&cs->req->waitq.lock);
>
> if (err) {
> @@ -939,8 +939,8 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep)
> goto out_put_old;
> }
>
> -static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
> - unsigned offset, unsigned count)
> +static int fuse_ref_folio(struct fuse_copy_state *cs, struct folio *folio,
> + unsigned offset, unsigned count)
> {
> struct pipe_buffer *buf;
> int err;
> @@ -948,17 +948,17 @@ static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
> if (cs->nr_segs >= cs->pipe->max_usage)
> return -EIO;
>
> - get_page(page);
> + folio_get(folio);
> err = unlock_request(cs->req);
> if (err) {
> - put_page(page);
> + folio_put(folio);
> return err;
> }
>
> fuse_copy_finish(cs);
>
> buf = cs->pipebufs;
> - buf->page = page;
> + buf->page = &folio->page;
> buf->offset = offset;
> buf->len = count;
>
> @@ -970,20 +970,24 @@ static int fuse_ref_page(struct fuse_copy_state *cs, struct page *page,
> }
>
> /*
> - * Copy a page in the request to/from the userspace buffer. Must be
> + * Copy a folio in the request to/from the userspace buffer. Must be
> * done atomically
> */
> -static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
> - unsigned offset, unsigned count, int zeroing)
> +static int fuse_copy_folio(struct fuse_copy_state *cs, struct folio **foliop,
> + unsigned offset, unsigned count, int zeroing)
> {
> int err;
> - struct page *page = *pagep;
> + struct folio *folio = *foliop;
> + size_t size = folio_size(folio);
>
> - if (page && zeroing && count < PAGE_SIZE)
> - clear_highpage(page);
> + if (folio && zeroing && count < size) {
> + void *kaddr = kmap_local_folio(folio, 0);
> + memset(kaddr, 0, size);
> + kunmap_local(kaddr);
There's a folio_zero_range() that can be used here instead of this, but be sure
you get it right, I definitely did it wrong recently and I think Jan had to fix
my mistake. Thanks,
Josef
