Commit e4b57722 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

shmem: convert shmem_get_link() to use a folio 

Symlinks will never use a large folio, but using the folio API removes a
lot of unnecessary folio->page->folio conversions.

Link: https://lkml.kernel.org/r/20220902194653.1739778-31-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 7ad0414b

mm/shmem.c

+17 −16
Original line number Diff line number Diff line
@@ -3143,40 +3143,41 @@ static int shmem_symlink(struct user_namespace *mnt_userns, struct inode *dir, 


static void shmem_put_link(void *arg)

{

	mark_page_accessed(arg);

	put_page(arg);

	folio_mark_accessed(arg);

	folio_put(arg);

}



static const char *shmem_get_link(struct dentry *dentry,

				  struct inode *inode,

				  struct delayed_call *done)

{

	struct page *page = NULL;

	struct folio *folio = NULL;

	int error;



	if (!dentry) {

		page = find_get_page(inode->i_mapping, 0);

		if (!page)

		folio = filemap_get_folio(inode->i_mapping, 0);

		if (!folio)

			return ERR_PTR(-ECHILD);

		if (PageHWPoison(page) ||

		    !PageUptodate(page)) {

			put_page(page);

		if (PageHWPoison(&folio->page) ||

		    !folio_test_uptodate(folio)) {

			folio_put(folio);

			return ERR_PTR(-ECHILD);

		}

	} else {

		error = shmem_getpage(inode, 0, &page, SGP_READ);

		error = shmem_get_folio(inode, 0, &folio, SGP_READ);

		if (error)

			return ERR_PTR(error);

		if (!page)

		if (!folio)

			return ERR_PTR(-ECHILD);

		if (PageHWPoison(page)) {

			unlock_page(page);

			put_page(page);

		if (PageHWPoison(&folio->page)) {

			folio_unlock(folio);

			folio_put(folio);

			return ERR_PTR(-ECHILD);

		}

		unlock_page(page);

		folio_unlock(folio);

	}

	set_delayed_call(done, shmem_put_link, page);

	return page_address(page);

	set_delayed_call(done, shmem_put_link, folio);

	return folio_address(folio);

}



#ifdef CONFIG_TMPFS_XATTR