On Wed, Jan 03, 2024 at 08:41:24AM +0000, Christoph Hellwig wrote:
> Pass a flags argument to xfile_get_page, and only allocate a new page
> if the XFILE_ALLOC flag is passed. This allows to also use
> xfile_get_page for pure readers that do not want to allocate a new
> page or dirty the existing one.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Looks correct to me,
Reviewed-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--D
> ---
> fs/xfs/scrub/xfarray.c | 2 +-
> fs/xfs/scrub/xfile.c | 14 ++++++++++----
> fs/xfs/scrub/xfile.h | 4 +++-
> 3 files changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/fs/xfs/scrub/xfarray.c b/fs/xfs/scrub/xfarray.c
> index 4f396462186793..8543067d46366d 100644
> --- a/fs/xfs/scrub/xfarray.c
> +++ b/fs/xfs/scrub/xfarray.c
> @@ -572,7 +572,7 @@ xfarray_sort_get_page(
> {
> struct page *page;
>
> - page = xfile_get_page(si->array->xfile, pos, len);
> + page = xfile_get_page(si->array->xfile, pos, len, XFILE_ALLOC);
> if (IS_ERR(page))
> return PTR_ERR(page);
> si->page = page;
> diff --git a/fs/xfs/scrub/xfile.c b/fs/xfs/scrub/xfile.c
> index 715c4d10b67c14..3ed7fb82a4497b 100644
> --- a/fs/xfs/scrub/xfile.c
> +++ b/fs/xfs/scrub/xfile.c
> @@ -274,7 +274,8 @@ struct page *
> xfile_get_page(
> struct xfile *xf,
> loff_t pos,
> - unsigned int len)
> + unsigned int len,
> + unsigned int flags)
> {
> struct inode *inode = file_inode(xf->file);
> struct folio *folio = NULL;
> @@ -293,15 +294,19 @@ xfile_get_page(
> * Increase the file size first so that shmem_get_folio(..., SGP_CACHE),
> * actually allocates a folio instead of erroring out.
> */
> - if (pos + len > i_size_read(inode))
> + if ((flags & XFILE_ALLOC) && pos + len > i_size_read(inode))
> i_size_write(inode, pos + len);
>
> pflags = memalloc_nofs_save();
> - error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio, SGP_CACHE);
> + error = shmem_get_folio(inode, pos >> PAGE_SHIFT, &folio,
> + (flags & XFILE_ALLOC) ? SGP_CACHE : SGP_READ);
> memalloc_nofs_restore(pflags);
> if (error)
> return ERR_PTR(error);
>
> + if (!folio)
> + return NULL;
> +
> page = folio_file_page(folio, pos >> PAGE_SHIFT);
> if (PageHWPoison(page)) {
> folio_put(folio);
> @@ -312,7 +317,8 @@ xfile_get_page(
> * Mark the page dirty so that it won't be reclaimed once we drop the
> * (potentially last) reference in xfile_put_page.
> */
> - set_page_dirty(page);
> + if (flags & XFILE_ALLOC)
> + set_page_dirty(page);
> return page;
> }
>
> diff --git a/fs/xfs/scrub/xfile.h b/fs/xfs/scrub/xfile.h
> index 993368b37b4b7c..f0403ea869e4d0 100644
> --- a/fs/xfs/scrub/xfile.h
> +++ b/fs/xfs/scrub/xfile.h
> @@ -19,7 +19,9 @@ int xfile_obj_store(struct xfile *xf, const void *buf, size_t count,
>
> loff_t xfile_seek_data(struct xfile *xf, loff_t pos);
>
> -struct page *xfile_get_page(struct xfile *xf, loff_t offset, unsigned int len);
> +#define XFILE_ALLOC (1 << 0) /* allocate page if not present */
> +struct page *xfile_get_page(struct xfile *xf, loff_t offset, unsigned int len,
> + unsigned int flags);
> void xfile_put_page(struct xfile *xf, struct page *page);
>
> #endif /* __XFS_SCRUB_XFILE_H__ */
> --
> 2.39.2
>
>
