mm: create new mm/swap.h header file

Patch series "MM changes to improve swap-over-NFS support".

Assorted improvements for swap-via-filesystem.

This is a resend of these patches, rebased on current HEAD.  The only
substantial changes is that swap_dirty_folio has replaced
swap_set_page_dirty.

Currently swap-via-fs (SWP_FS_OPS) doesn't work for any filesystem.  It
has previously worked for NFS but that broke a few releases back.  This
series changes to use a new ->swap_rw rather than ->readpage and
->direct_IO.  It also makes other improvements.

There is a companion series already in linux-next which fixes various
issues with NFS.  Once both series land, a final patch is needed which
changes NFS over to use ->swap_rw.


This patch (of 10):

Many functions declared in include/linux/swap.h are only used within mm/

Create a new "mm/swap.h" and move some of these declarations there.
Remove the redundant 'extern' from the function declarations.

[akpm@linux-foundation.org: mm/memory-failure.c needs mm/swap.h]
Link: https://lkml.kernel.org/r/164859751830.29473.5309689752169286816.stgit@noble.brown
Link: https://lkml.kernel.org/r/164859778120.29473.11725907882296224053.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Howells <dhowells@redhat.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
NeilBrown 2022-05-09 18:20:47 -07:00 committed by akpm
parent 17de1e559c
commit 014bb1de4f
16 changed files with 148 additions and 121 deletions

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@ -427,62 +427,19 @@ extern void kswapd_stop(int nid);
#ifdef CONFIG_SWAP
#include <linux/blk_types.h> /* for bio_end_io_t */
/* linux/mm/page_io.c */
extern int swap_readpage(struct page *page, bool do_poll);
extern int swap_writepage(struct page *page, struct writeback_control *wbc);
extern void end_swap_bio_write(struct bio *bio);
extern int __swap_writepage(struct page *page, struct writeback_control *wbc,
bio_end_io_t end_write_func);
bool swap_dirty_folio(struct address_space *mapping, struct folio *folio);
int add_swap_extent(struct swap_info_struct *sis, unsigned long start_page,
unsigned long nr_pages, sector_t start_block);
int generic_swapfile_activate(struct swap_info_struct *, struct file *,
sector_t *);
/* linux/mm/swap_state.c */
/* One swap address space for each 64M swap space */
#define SWAP_ADDRESS_SPACE_SHIFT 14
#define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT)
extern struct address_space *swapper_spaces[];
#define swap_address_space(entry) \
(&swapper_spaces[swp_type(entry)][swp_offset(entry) \
>> SWAP_ADDRESS_SPACE_SHIFT])
static inline unsigned long total_swapcache_pages(void)
{
return global_node_page_state(NR_SWAPCACHE);
}
extern void show_swap_cache_info(void);
extern int add_to_swap(struct page *page);
extern void *get_shadow_from_swap_cache(swp_entry_t entry);
extern int add_to_swap_cache(struct page *page, swp_entry_t entry,
gfp_t gfp, void **shadowp);
extern void __delete_from_swap_cache(struct page *page,
swp_entry_t entry, void *shadow);
extern void delete_from_swap_cache(struct page *);
extern void clear_shadow_from_swap_cache(int type, unsigned long begin,
unsigned long end);
extern void free_swap_cache(struct page *);
extern void free_page_and_swap_cache(struct page *);
extern void free_pages_and_swap_cache(struct page **, int);
extern struct page *lookup_swap_cache(swp_entry_t entry,
struct vm_area_struct *vma,
unsigned long addr);
struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index);
extern struct page *read_swap_cache_async(swp_entry_t, gfp_t,
struct vm_area_struct *vma, unsigned long addr,
bool do_poll);
extern struct page *__read_swap_cache_async(swp_entry_t, gfp_t,
struct vm_area_struct *vma, unsigned long addr,
bool *new_page_allocated);
extern struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
struct vm_fault *vmf);
extern struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
struct vm_fault *vmf);
/* linux/mm/swapfile.c */
extern atomic_long_t nr_swap_pages;
extern long total_swap_pages;
@ -535,12 +492,6 @@ static inline void put_swap_device(struct swap_info_struct *si)
}
#else /* CONFIG_SWAP */
static inline int swap_readpage(struct page *page, bool do_poll)
{
return 0;
}
static inline struct swap_info_struct *swp_swap_info(swp_entry_t entry)
{
return NULL;
@ -555,11 +506,6 @@ static inline void put_swap_device(struct swap_info_struct *si)
{
}
static inline struct address_space *swap_address_space(swp_entry_t entry)
{
return NULL;
}
#define get_nr_swap_pages() 0L
#define total_swap_pages 0L
#define total_swapcache_pages() 0UL
@ -574,14 +520,6 @@ static inline struct address_space *swap_address_space(swp_entry_t entry)
#define free_pages_and_swap_cache(pages, nr) \
release_pages((pages), (nr));
static inline void free_swap_cache(struct page *page)
{
}
static inline void show_swap_cache_info(void)
{
}
/* used to sanity check ptes in zap_pte_range when CONFIG_SWAP=0 */
#define free_swap_and_cache(e) is_pfn_swap_entry(e)
@ -607,65 +545,6 @@ static inline void put_swap_page(struct page *page, swp_entry_t swp)
{
}
static inline struct page *swap_cluster_readahead(swp_entry_t entry,
gfp_t gfp_mask, struct vm_fault *vmf)
{
return NULL;
}
static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
struct vm_fault *vmf)
{
return NULL;
}
static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
{
return 0;
}
static inline struct page *lookup_swap_cache(swp_entry_t swp,
struct vm_area_struct *vma,
unsigned long addr)
{
return NULL;
}
static inline
struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
{
return find_get_page(mapping, index);
}
static inline int add_to_swap(struct page *page)
{
return 0;
}
static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
{
return NULL;
}
static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
gfp_t gfp_mask, void **shadowp)
{
return -1;
}
static inline void __delete_from_swap_cache(struct page *page,
swp_entry_t entry, void *shadow)
{
}
static inline void delete_from_swap_cache(struct page *page)
{
}
static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
unsigned long end)
{
}
static inline int page_swapcount(struct page *page)
{

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@ -39,6 +39,7 @@
#include <asm/tlb.h>
#include <asm/pgalloc.h>
#include "internal.h"
#include "swap.h"
#define CREATE_TRACE_POINTS
#include <trace/events/thp.h>

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@ -35,6 +35,7 @@
#include <asm/tlb.h>
#include "internal.h"
#include "swap.h"
struct madvise_walk_private {
struct mmu_gather *tlb;

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@ -67,6 +67,7 @@
#include <net/sock.h>
#include <net/ip.h>
#include "slab.h"
#include "swap.h"
#include <linux/uaccess.h>

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@ -59,6 +59,7 @@
#include <linux/page-isolation.h>
#include <linux/pagewalk.h>
#include <linux/shmem_fs.h>
#include "swap.h"
#include "internal.h"
#include "ras/ras_event.h"

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@ -86,6 +86,7 @@
#include "pgalloc-track.h"
#include "internal.h"
#include "swap.h"
#if defined(LAST_CPUPID_NOT_IN_PAGE_FLAGS) && !defined(CONFIG_COMPILE_TEST)
#warning Unfortunate NUMA and NUMA Balancing config, growing page-frame for last_cpupid.

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@ -20,6 +20,7 @@
#include <linux/pgtable.h>
#include <linux/uaccess.h>
#include "swap.h"
static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr,
unsigned long end, struct mm_walk *walk)

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@ -81,6 +81,7 @@
#include "internal.h"
#include "shuffle.h"
#include "page_reporting.h"
#include "swap.h"
/* Free Page Internal flags: for internal, non-pcp variants of free_pages(). */
typedef int __bitwise fpi_t;

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@ -26,6 +26,7 @@
#include <linux/uio.h>
#include <linux/sched/task.h>
#include <linux/delayacct.h>
#include "swap.h"
void end_swap_bio_write(struct bio *bio)
{

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@ -38,6 +38,7 @@
#include <linux/hugetlb.h>
#include <linux/fs_parser.h>
#include <linux/swapfile.h>
#include "swap.h"
static struct vfsmount *shm_mnt;

133
mm/swap.h Normal file
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@ -0,0 +1,133 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _MM_SWAP_H
#define _MM_SWAP_H
#ifdef CONFIG_SWAP
#include <linux/blk_types.h> /* for bio_end_io_t */
/* linux/mm/page_io.c */
int swap_readpage(struct page *page, bool do_poll);
int swap_writepage(struct page *page, struct writeback_control *wbc);
void end_swap_bio_write(struct bio *bio);
int __swap_writepage(struct page *page, struct writeback_control *wbc,
bio_end_io_t end_write_func);
/* linux/mm/swap_state.c */
/* One swap address space for each 64M swap space */
#define SWAP_ADDRESS_SPACE_SHIFT 14
#define SWAP_ADDRESS_SPACE_PAGES (1 << SWAP_ADDRESS_SPACE_SHIFT)
extern struct address_space *swapper_spaces[];
#define swap_address_space(entry) \
(&swapper_spaces[swp_type(entry)][swp_offset(entry) \
>> SWAP_ADDRESS_SPACE_SHIFT])
void show_swap_cache_info(void);
int add_to_swap(struct page *page);
void *get_shadow_from_swap_cache(swp_entry_t entry);
int add_to_swap_cache(struct page *page, swp_entry_t entry,
gfp_t gfp, void **shadowp);
void __delete_from_swap_cache(struct page *page,
swp_entry_t entry, void *shadow);
void delete_from_swap_cache(struct page *page);
void clear_shadow_from_swap_cache(int type, unsigned long begin,
unsigned long end);
void free_swap_cache(struct page *page);
struct page *lookup_swap_cache(swp_entry_t entry,
struct vm_area_struct *vma,
unsigned long addr);
struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index);
struct page *read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
struct vm_area_struct *vma,
unsigned long addr,
bool do_poll);
struct page *__read_swap_cache_async(swp_entry_t entry, gfp_t gfp_mask,
struct vm_area_struct *vma,
unsigned long addr,
bool *new_page_allocated);
struct page *swap_cluster_readahead(swp_entry_t entry, gfp_t flag,
struct vm_fault *vmf);
struct page *swapin_readahead(swp_entry_t entry, gfp_t flag,
struct vm_fault *vmf);
#else /* CONFIG_SWAP */
static inline int swap_readpage(struct page *page, bool do_poll)
{
return 0;
}
static inline struct address_space *swap_address_space(swp_entry_t entry)
{
return NULL;
}
static inline void free_swap_cache(struct page *page)
{
}
static inline void show_swap_cache_info(void)
{
}
static inline struct page *swap_cluster_readahead(swp_entry_t entry,
gfp_t gfp_mask, struct vm_fault *vmf)
{
return NULL;
}
static inline struct page *swapin_readahead(swp_entry_t swp, gfp_t gfp_mask,
struct vm_fault *vmf)
{
return NULL;
}
static inline int swap_writepage(struct page *p, struct writeback_control *wbc)
{
return 0;
}
static inline struct page *lookup_swap_cache(swp_entry_t swp,
struct vm_area_struct *vma,
unsigned long addr)
{
return NULL;
}
static inline
struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
{
return find_get_page(mapping, index);
}
static inline int add_to_swap(struct page *page)
{
return 0;
}
static inline void *get_shadow_from_swap_cache(swp_entry_t entry)
{
return NULL;
}
static inline int add_to_swap_cache(struct page *page, swp_entry_t entry,
gfp_t gfp_mask, void **shadowp)
{
return -1;
}
static inline void __delete_from_swap_cache(struct page *page,
swp_entry_t entry, void *shadow)
{
}
static inline void delete_from_swap_cache(struct page *page)
{
}
static inline void clear_shadow_from_swap_cache(int type, unsigned long begin,
unsigned long end)
{
}
#endif /* CONFIG_SWAP */
#endif /* _MM_SWAP_H */

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@ -23,6 +23,7 @@
#include <linux/huge_mm.h>
#include <linux/shmem_fs.h>
#include "internal.h"
#include "swap.h"
/*
* swapper_space is a fiction, retained to simplify the path through

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@ -44,6 +44,7 @@
#include <asm/tlbflush.h>
#include <linux/swapops.h>
#include <linux/swap_cgroup.h>
#include "swap.h"
static bool swap_count_continued(struct swap_info_struct *, pgoff_t,
unsigned char);

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@ -27,6 +27,7 @@
#include <linux/uaccess.h>
#include "internal.h"
#include "swap.h"
/**
* kfree_const - conditionally free memory

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@ -59,6 +59,7 @@
#include <linux/sched/sysctl.h>
#include "internal.h"
#include "swap.h"
#define CREATE_TRACE_POINTS
#include <trace/events/vmscan.h>

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@ -36,6 +36,8 @@
#include <linux/pagemap.h>
#include <linux/workqueue.h>
#include "swap.h"
/*********************************
* statistics
**********************************/