diff options
| -rw-r--r-- | mm/migrate.c | 142 |
1 files changed, 72 insertions, 70 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 1c25040693d..49e71ddb679 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -120,15 +120,6 @@ int putback_lru_pages(struct list_head *l) } /* - * Non migratable page - */ -int fail_migrate_page(struct page *newpage, struct page *page) -{ - return -EIO; -} -EXPORT_SYMBOL(fail_migrate_page); - -/* * swapout a single page * page is locked upon entry, unlocked on exit */ @@ -297,6 +288,17 @@ void migrate_page_copy(struct page *newpage, struct page *page) } EXPORT_SYMBOL(migrate_page_copy); +/************************************************************ + * Migration functions + ***********************************************************/ + +/* Always fail migration. Used for mappings that are not movable */ +int fail_migrate_page(struct page *newpage, struct page *page) +{ + return -EIO; +} +EXPORT_SYMBOL(fail_migrate_page); + /* * Common logic to directly migrate a single page suitable for * pages that do not use PagePrivate. @@ -330,6 +332,67 @@ int migrate_page(struct page *newpage, struct page *page) EXPORT_SYMBOL(migrate_page); /* + * Migration function for pages with buffers. This function can only be used + * if the underlying filesystem guarantees that no other references to "page" + * exist. + */ +int buffer_migrate_page(struct page *newpage, struct page *page) +{ + struct address_space *mapping = page->mapping; + struct buffer_head *bh, *head; + int rc; + + if (!mapping) + return -EAGAIN; + + if (!page_has_buffers(page)) + return migrate_page(newpage, page); + + head = page_buffers(page); + + rc = migrate_page_remove_references(newpage, page, 3); + + if (rc) + return rc; + + bh = head; + do { + get_bh(bh); + lock_buffer(bh); + bh = bh->b_this_page; + + } while (bh != head); + + ClearPagePrivate(page); + set_page_private(newpage, page_private(page)); + set_page_private(page, 0); + put_page(page); + get_page(newpage); + + bh = head; + do { + set_bh_page(bh, newpage, bh_offset(bh)); + bh = bh->b_this_page; + + } while (bh != head); + + SetPagePrivate(newpage); + + migrate_page_copy(newpage, page); + + bh = head; + do { + unlock_buffer(bh); + put_bh(bh); + bh = bh->b_this_page; + + } while (bh != head); + + return 0; +} +EXPORT_SYMBOL(buffer_migrate_page); + +/* * migrate_pages * * Two lists are passed to this function. The first list @@ -529,67 +592,6 @@ next: } /* - * Migration function for pages with buffers. This function can only be used - * if the underlying filesystem guarantees that no other references to "page" - * exist. - */ -int buffer_migrate_page(struct page *newpage, struct page *page) -{ - struct address_space *mapping = page->mapping; - struct buffer_head *bh, *head; - int rc; - - if (!mapping) - return -EAGAIN; - - if (!page_has_buffers(page)) - return migrate_page(newpage, page); - - head = page_buffers(page); - - rc = migrate_page_remove_references(newpage, page, 3); - - if (rc) - return rc; - - bh = head; - do { - get_bh(bh); - lock_buffer(bh); - bh = bh->b_this_page; - - } while (bh != head); - - ClearPagePrivate(page); - set_page_private(newpage, page_private(page)); - set_page_private(page, 0); - put_page(page); - get_page(newpage); - - bh = head; - do { - set_bh_page(bh, newpage, bh_offset(bh)); - bh = bh->b_this_page; - - } while (bh != head); - - SetPagePrivate(newpage); - - migrate_page_copy(newpage, page); - - bh = head; - do { - unlock_buffer(bh); - put_bh(bh); - bh = bh->b_this_page; - - } while (bh != head); - - return 0; -} -EXPORT_SYMBOL(buffer_migrate_page); - -/* * Migrate the list 'pagelist' of pages to a certain destination. * * Specify destination with either non-NULL vma or dest_node >= 0 |