Commit 97b76796 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

swap: convert swapon() to use a folio 

Retrieve a folio from the page cache rather than a page.  Saves a couple
of conversions between page & folio.

Link: https://lkml.kernel.org/r/20240826202138.3804238-1-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 8175ebfd

mm/swapfile.c

+7 −9
Original line number Diff line number Diff line
@@ -3357,7 +3357,7 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) 
	unsigned char *swap_map = NULL;

	unsigned long *zeromap = NULL;

	struct swap_cluster_info *cluster_info = NULL;

	struct page *page = NULL;

	struct folio *folio = NULL;

	struct inode *inode = NULL;

	bool inced_nr_rotate_swap = false;
@@ -3415,12 +3415,12 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) 
		error = -EINVAL;

		goto bad_swap_unlock_inode;

	}

	page = read_mapping_page(mapping, 0, swap_file);

	if (IS_ERR(page)) {

		error = PTR_ERR(page);

	folio = read_mapping_folio(mapping, 0, swap_file);

	if (IS_ERR(folio)) {

		error = PTR_ERR(folio);

		goto bad_swap_unlock_inode;

	}

	swap_header = kmap(page);

	swap_header = kmap_local_folio(folio, 0);



	maxpages = read_swap_header(si, swap_header, inode);

	if (unlikely(!maxpages)) {
@@ -3574,10 +3574,8 @@ SYSCALL_DEFINE2(swapon, const char __user *, specialfile, int, swap_flags) 
	if (swap_file)

		filp_close(swap_file, NULL);

out:

	if (page && !IS_ERR(page)) {

		kunmap(page);

		put_page(page);

	}

	if (!IS_ERR_OR_NULL(folio))

		folio_release_kmap(folio, swap_header);

	if (name)

		putname(name);

	if (inode)