From: Jan Kara <jack@xxxxxxx> Subject: 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@xxxxxxx Signed-off-by: Jan Kara <jack@xxxxxxx> Acked-by: Mel Gorman <mgorman@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- --- a/mm/migrate.c~mm-migrate-move-migrate_page_lock_buffers +++ a/mm/migrate.c @@ -374,56 +374,6 @@ unlock: } #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 *m 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" _
