Commit 7ca8783a authored by Wei Yang's avatar Wei Yang Committed by Linus Torvalds
Browse files

mm/migrate.c: wrap do_move_pages_to_node() and store_status() 



Usually, do_move_pages_to_node() and store_status() are used in
combination.  We have three similar call sites.

Let's provide a wrapper for both function calls -
move_pages_and_store_status - to make the calling code easier to maintain
and fix (as noted by Yang Shi, the return value handling of
do_move_pages_to_node() has a flaw).

[david@redhat.com rephrase changelog]
Signed-off-by: default avatarWei Yang <richardw.yang@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Link: http://lkml.kernel.org/r/20200214003017.25558-3-richardw.yang@linux.intel.com


Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4afdacec

mm/migrate.c

+29 −32
Original line number Diff line number Diff line
@@ -1602,6 +1602,29 @@ out: 
	return err;

}



static int move_pages_and_store_status(struct mm_struct *mm, int node,

		struct list_head *pagelist, int __user *status,

		int start, int i, unsigned long nr_pages)

{

	int err;



	err = do_move_pages_to_node(mm, pagelist, node);

	if (err) {

		/*

		 * Positive err means the number of failed

		 * pages to migrate.  Since we are going to

		 * abort and return the number of non-migrated

		 * pages, so need to incude the rest of the

		 * nr_pages that have not been attempted as

		 * well.

		 */

		if (err > 0)

			err += nr_pages - i - 1;

		return err;

	}

	return store_status(status, start, node, i - start);

}



/*

 * Migrate an array of page address onto an array of nodes and fill

 * the corresponding array of status.
@@ -1645,21 +1668,8 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, 
			current_node = node;

			start = i;

		} else if (node != current_node) {

			err = do_move_pages_to_node(mm, &pagelist, current_node);

			if (err) {

				/*

				 * Positive err means the number of failed

				 * pages to migrate.  Since we are going to

				 * abort and return the number of non-migrated

				 * pages, so need to incude the rest of the

				 * nr_pages that have not been attempted as

				 * well.

				 */

				if (err > 0)

					err += nr_pages - i - 1;

				goto out;

			}

			err = store_status(status, start, current_node, i - start);

			err = move_pages_and_store_status(mm, current_node,

					&pagelist, status, start, i, nr_pages);

			if (err)

				goto out;

			start = i;
@@ -1688,13 +1698,8 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, 
		if (err)

			goto out_flush;



		err = do_move_pages_to_node(mm, &pagelist, current_node);

		if (err) {

			if (err > 0)

				err += nr_pages - i - 1;

			goto out;

		}

		err = store_status(status, start, current_node, i - start);

		err = move_pages_and_store_status(mm, current_node, &pagelist,

				status, start, i, nr_pages);

		if (err)

			goto out;

		current_node = NUMA_NO_NODE;
@@ -1704,16 +1709,8 @@ out_flush: 
		return err;



	/* Make sure we do not overwrite the existing error */

	err1 = do_move_pages_to_node(mm, &pagelist, current_node);

	/*

	 * Don't have to report non-attempted pages here since:

	 *     - If the above loop is done gracefully all pages have been

	 *       attempted.

	 *     - If the above loop is aborted it means a fatal error

	 *       happened, should return ret.

	 */

	if (!err1)

		err1 = store_status(status, start, current_node, i - start);

	err1 = move_pages_and_store_status(mm, current_node, &pagelist,

				status, start, i, nr_pages);

	if (err >= 0)

		err = err1;

out:

CRA Git | Maintained and supported by SUSTech CRA and CCSE