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-rw-r--r--fs/hugetlbfs/inode.c4
-rw-r--r--include/linux/migrate.h7
-rw-r--r--mm/migrate.c33
3 files changed, 24 insertions, 20 deletions
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 47e6e2f21e2..4a55f35a6ce 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -582,11 +582,11 @@ static int hugetlbfs_migrate_page(struct address_space *mapping,
int rc;
rc = migrate_huge_page_move_mapping(mapping, newpage, page);
- if (rc)
+ if (rc != MIGRATEPAGE_SUCCESS)
return rc;
migrate_page_copy(newpage, page);
- return 0;
+ return MIGRATEPAGE_SUCCESS;
}
static int hugetlbfs_statfs(struct dentry *dentry, struct kstatfs *buf)
diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index ce7e6671968..a4e886d17f8 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -7,6 +7,13 @@
typedef struct page *new_page_t(struct page *, unsigned long private, int **);
+/*
+ * Return values from addresss_space_operations.migratepage():
+ * - negative errno on page migration failure;
+ * - zero on page migration success;
+ */
+#define MIGRATEPAGE_SUCCESS 0
+
#ifdef CONFIG_MIGRATION
extern void putback_lru_pages(struct list_head *l);
diff --git a/mm/migrate.c b/mm/migrate.c
index 1dc4598d251..33f5f82a600 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -276,7 +276,7 @@ static int migrate_page_move_mapping(struct address_space *mapping,
/* Anonymous page without mapping */
if (page_count(page) != 1)
return -EAGAIN;
- return 0;
+ return MIGRATEPAGE_SUCCESS;
}
spin_lock_irq(&mapping->tree_lock);
@@ -346,7 +346,7 @@ static int migrate_page_move_mapping(struct address_space *mapping,
}
spin_unlock_irq(&mapping->tree_lock);
- return 0;
+ return MIGRATEPAGE_SUCCESS;
}
/*
@@ -362,7 +362,7 @@ int migrate_huge_page_move_mapping(struct address_space *mapping,
if (!mapping) {
if (page_count(page) != 1)
return -EAGAIN;
- return 0;
+ return MIGRATEPAGE_SUCCESS;
}
spin_lock_irq(&mapping->tree_lock);
@@ -389,7 +389,7 @@ int migrate_huge_page_move_mapping(struct address_space *mapping,
page_unfreeze_refs(page, expected_count - 1);
spin_unlock_irq(&mapping->tree_lock);
- return 0;
+ return MIGRATEPAGE_SUCCESS;
}
/*
@@ -476,11 +476,11 @@ int migrate_page(struct address_space *mapping,
rc = migrate_page_move_mapping(mapping, newpage, page, NULL, mode);
- if (rc)
+ if (rc != MIGRATEPAGE_SUCCESS)
return rc;
migrate_page_copy(newpage, page);
- return 0;
+ return MIGRATEPAGE_SUCCESS;
}
EXPORT_SYMBOL(migrate_page);
@@ -503,7 +503,7 @@ int buffer_migrate_page(struct address_space *mapping,
rc = migrate_page_move_mapping(mapping, newpage, page, head, mode);
- if (rc)
+ if (rc != MIGRATEPAGE_SUCCESS)
return rc;
/*
@@ -539,7 +539,7 @@ int buffer_migrate_page(struct address_space *mapping,
} while (bh != head);
- return 0;
+ return MIGRATEPAGE_SUCCESS;
}
EXPORT_SYMBOL(buffer_migrate_page);
#endif
@@ -618,7 +618,7 @@ static int fallback_migrate_page(struct address_space *mapping,
*
* Return value:
* < 0 - error code
- * == 0 - success
+ * MIGRATEPAGE_SUCCESS - success
*/
static int move_to_new_page(struct page *newpage, struct page *page,
int remap_swapcache, enum migrate_mode mode)
@@ -655,7 +655,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
else
rc = fallback_migrate_page(mapping, newpage, page, mode);
- if (rc) {
+ if (rc != MIGRATEPAGE_SUCCESS) {
newpage->mapping = NULL;
} else {
if (remap_swapcache)
@@ -804,7 +804,7 @@ skip_unmap:
put_anon_vma(anon_vma);
uncharge:
- mem_cgroup_end_migration(mem, page, newpage, rc == 0);
+ mem_cgroup_end_migration(mem, page, newpage, rc == MIGRATEPAGE_SUCCESS);
unlock:
unlock_page(page);
out:
@@ -977,7 +977,7 @@ int migrate_pages(struct list_head *from,
case -EAGAIN:
retry++;
break;
- case 0:
+ case MIGRATEPAGE_SUCCESS:
break;
default:
/* Permanent failure */
@@ -986,15 +986,12 @@ int migrate_pages(struct list_head *from,
}
}
}
- rc = 0;
+ rc = nr_failed + retry;
out:
if (!swapwrite)
current->flags &= ~PF_SWAPWRITE;
- if (rc)
- return rc;
-
- return nr_failed + retry;
+ return rc;
}
int migrate_huge_page(struct page *hpage, new_page_t get_new_page,
@@ -1014,7 +1011,7 @@ int migrate_huge_page(struct page *hpage, new_page_t get_new_page,
/* try again */
cond_resched();
break;
- case 0:
+ case MIGRATEPAGE_SUCCESS:
goto out;
default:
rc = -EIO;