Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 84ade7c1 authored by Jan Kara's avatar Jan Kara Committed by Linus Torvalds
Browse files

mm: migrate: move migrate_page_lock_buffers() 

buffer_migrate_page() is the only caller of migrate_page_lock_buffers()
move it close to it and also drop the now unused stub for !CONFIG_BLOCK.

Link: http://lkml.kernel.org/r/20181211172143.7358-4-jack@suse.cz


Signed-off-by: default avatarJan Kara <jack@suse.cz>
Acked-by: default avatarMel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent cc4f11e6

mm/migrate.c

+42 −50
Original line number Diff line number Diff line
@@ -374,56 +374,6 @@ void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd) 
}

#endif



#ifdef CONFIG_BLOCK

/* Returns true if all buffers are successfully locked */

static bool buffer_migrate_lock_buffers(struct buffer_head *head,

							enum migrate_mode mode)

{

	struct buffer_head *bh = head;



	/* Simple case, sync compaction */

	if (mode != MIGRATE_ASYNC) {

		do {

			get_bh(bh);

			lock_buffer(bh);

			bh = bh->b_this_page;



		} while (bh != head);



		return true;

	}



	/* async case, we cannot block on lock_buffer so use trylock_buffer */

	do {

		get_bh(bh);

		if (!trylock_buffer(bh)) {

			/*

			 * We failed to lock the buffer and cannot stall in

			 * async migration. Release the taken locks

			 */

			struct buffer_head *failed_bh = bh;

			put_bh(failed_bh);

			bh = head;

			while (bh != failed_bh) {

				unlock_buffer(bh);

				put_bh(bh);

				bh = bh->b_this_page;

			}

			return false;

		}



		bh = bh->b_this_page;

	} while (bh != head);

	return true;

}

#else

static inline bool buffer_migrate_lock_buffers(struct buffer_head *head,

							enum migrate_mode mode)

{

	return true;

}

#endif /* CONFIG_BLOCK */



static int expected_page_refs(struct page *page)

{

	int expected_count = 1;
@@ -751,6 +701,48 @@ int migrate_page(struct address_space *mapping, 
EXPORT_SYMBOL(migrate_page);



#ifdef CONFIG_BLOCK

/* Returns true if all buffers are successfully locked */

static bool buffer_migrate_lock_buffers(struct buffer_head *head,

							enum migrate_mode mode)

{

	struct buffer_head *bh = head;



	/* Simple case, sync compaction */

	if (mode != MIGRATE_ASYNC) {

		do {

			get_bh(bh);

			lock_buffer(bh);

			bh = bh->b_this_page;



		} while (bh != head);



		return true;

	}



	/* async case, we cannot block on lock_buffer so use trylock_buffer */

	do {

		get_bh(bh);

		if (!trylock_buffer(bh)) {

			/*

			 * We failed to lock the buffer and cannot stall in

			 * async migration. Release the taken locks

			 */

			struct buffer_head *failed_bh = bh;

			put_bh(failed_bh);

			bh = head;

			while (bh != failed_bh) {

				unlock_buffer(bh);

				put_bh(bh);

				bh = bh->b_this_page;

			}

			return false;

		}



		bh = bh->b_this_page;

	} while (bh != head);

	return true;

}



/*

 * Migration function for pages with buffers. This function can only be used

 * if the underlying filesystem guarantees that no other references to "page"