Hi Luis,
On 1/29/25 19:44, Luis Henriques wrote:
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index 27ccae63495d..9a0cd88a9bb9 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1630,6 +1630,7 @@ static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
> unsigned int num;
> loff_t file_size;
> loff_t end;
> + int fgp_flags = FGP_LOCK | FGP_ACCESSED | FGP_CREAT;
>
> err = -EINVAL;
> if (size < sizeof(outarg))
> @@ -1645,6 +1646,9 @@ static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
>
> nodeid = outarg.nodeid;
>
> + if (outarg.flags & FUSE_NOTIFY_STORE_NOWAIT)
> + fgp_flags |= FGP_NOWAIT;
> +
> down_read(&fc->killsb);
>
> err = -ENOENT;
> @@ -1668,14 +1672,25 @@ static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
> struct page *page;
> unsigned int this_num;
>
> - folio = filemap_grab_folio(mapping, index);
> - err = PTR_ERR(folio);
> - if (IS_ERR(folio))
> - goto out_iput;
> + folio = __filemap_get_folio(mapping, index, fgp_flags,
> + mapping_gfp_mask(mapping));
> + err = PTR_ERR_OR_ZERO(folio);
> + if (err) {
> + if (!(outarg.flags & FUSE_NOTIFY_STORE_NOWAIT))
> + goto out_iput;
> + page = NULL;
> + /* XXX */
What is the XXX for?
Also, I think you want to go to "skip" only on -EAGAIN? And if so, need
to unset err?
> + this_num = min_t(unsigned int, num, PAGE_SIZE - offset);
> + } else {
> + page = &folio->page;
> + this_num = min_t(unsigned int, num,
> + folio_size(folio) - offset);
> + }
>
> - page = &folio->page;
> - this_num = min_t(unsigned, num, folio_size(folio) - offset);
> err = fuse_copy_page(cs, &page, offset, this_num, 0);
> + if (!page)
> + goto skip;
> +
> if (!folio_test_uptodate(folio) && !err && offset == 0 &&
> (this_num == folio_size(folio) || file_size == end)) {
> folio_zero_segment(folio, this_num, folio_size(folio));
> @@ -1683,7 +1698,7 @@ static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
> }
> folio_unlock(folio);
> folio_put(folio);
> -
> +skip:
> if (err)
> goto out_iput;
>
> diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
> index e9e78292d107..59725f89340e 100644
> --- a/include/uapi/linux/fuse.h
> +++ b/include/uapi/linux/fuse.h
> @@ -576,6 +576,12 @@ struct fuse_file_lock {
> */
> #define FUSE_EXPIRE_ONLY (1 << 0)
>
> +/**
> + * notify_store flags
> + * FUSE_NOTIFY_STORE_NOWAIT: skip locked pages
> + */
> +#define FUSE_NOTIFY_STORE_NOWAIT (1 << 0)
> +
> /**
> * extension type
> * FUSE_MAX_NR_SECCTX: maximum value of &fuse_secctx_header.nr_secctx
> @@ -1075,7 +1081,7 @@ struct fuse_notify_store_out {
> uint64_t nodeid;
> uint64_t offset;
> uint32_t size;
> - uint32_t padding;
> + uint32_t flags;
> };
>
> struct fuse_notify_retrieve_out {
>
Thanks,
Bernd
