Commit 61acad15 authored by Tong Tiangen's avatar Tong Tiangen
Browse files

mm/migration: do not folio copy in MIGRATE_SYNC_NO_COPY mode 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IASFAM



--------------------------------

During page migration, if MIGRATE_SYNC_NO_COPY mode is used, the page
content should not be migrated.

This patch fix it.

Fixes: 374fe8ea ("fs: hugetlbfs: support poisoned recover from hugetlbfs_migrate_folio()")
Fixes: 1d263184 ("mm: migrate: support poisoned recover from migrate folio")
Signed-off-by: default avatarTong Tiangen <tongtiangen@huawei.com>
parent 497bb858

fs/hugetlbfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -1146,7 +1146,7 @@ static int hugetlbfs_migrate_folio(struct address_space *mapping, 
{

	int rc;



	rc = migrate_huge_page_move_mapping(mapping, dst, src);

	rc = migrate_huge_page_move_mapping(mapping, dst, src, mode);

	if (rc != MIGRATEPAGE_SUCCESS)

		return rc;

include/linux/migrate.h

+2 −2
Original line number Diff line number Diff line
@@ -72,7 +72,7 @@ struct folio *alloc_migration_target(struct folio *src, unsigned long private); 
bool isolate_movable_page(struct page *page, isolate_mode_t mode);



int migrate_huge_page_move_mapping(struct address_space *mapping,

		struct folio *dst, struct folio *src);

		struct folio *dst, struct folio *src, enum migrate_mode mode);

void migration_entry_wait_on_locked(swp_entry_t entry, spinlock_t *ptl)

		__releases(ptl);

void folio_migrate_flags(struct folio *newfolio, struct folio *folio);
@@ -94,7 +94,7 @@ static inline bool isolate_movable_page(struct page *page, isolate_mode_t mode) 
	{ return false; }



static inline int migrate_huge_page_move_mapping(struct address_space *mapping,

				  struct folio *dst, struct folio *src)

		struct folio *dst, struct folio *src, enum migrate_mode mode)

{

	return -ENOSYS;

}

mm/migrate.c

+16 −10
Original line number Diff line number Diff line
@@ -544,20 +544,30 @@ int folio_migrate_mapping(struct address_space *mapping, 
}

EXPORT_SYMBOL(folio_migrate_mapping);



static int folio_migrate_mc_copy(struct folio *dst, struct folio *src,

				 enum migrate_mode mode, int expected_count)

{

	/* Check whether src does not have extra refs before we do more work */

	if (folio_ref_count(src) != expected_count)

		return -EAGAIN;



	if (mode == MIGRATE_SYNC_NO_COPY)

		return 0;



	return folio_mc_copy(dst, src);

}



/*

 * The expected number of remaining references is the same as that

 * of folio_migrate_mapping().

 */

int migrate_huge_page_move_mapping(struct address_space *mapping,

				   struct folio *dst, struct folio *src)

		struct folio *dst, struct folio *src, enum migrate_mode mode)

{

	XA_STATE(xas, &mapping->i_pages, folio_index(src));

	int rc, expected_count = folio_expected_refs(mapping, src);



	if (folio_ref_count(src) != expected_count)

		return -EAGAIN;



	rc = folio_mc_copy(dst, src);

	rc = folio_migrate_mc_copy(dst, src, mode, expected_count);

	if (unlikely(rc))

		return rc;
@@ -691,11 +701,7 @@ static int __migrate_folio(struct address_space *mapping, struct folio *dst, 
{

	int rc, expected_count = folio_expected_refs(mapping, src);



	/* Check whether src does not have extra refs before we do more work */

	if (folio_ref_count(src) != expected_count)

		return -EAGAIN;



	rc = folio_mc_copy(dst, src);

	rc = folio_migrate_mc_copy(dst, src, mode, expected_count);

	if (unlikely(rc))

		return rc;