raid5-cache: simplify r5l_move_io_unit_list

It's only used for one kind of move, so make that explicit.  Also clean
up the code a bit by using list_for_each_safe.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index b887e04d7e5c2554b3112de0f9fa5e61b93ed40b..3699c4704ba853d6ac31e9e34bdf8467c8e6e010 100644 (file)
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -156,21 +156,6 @@ static void r5l_free_io_unit(struct r5l_log *log, struct r5l_io_unit *io)
        kmem_cache_free(log->io_kc, io);
 }
 
-static void r5l_move_io_unit_list(struct list_head *from, struct list_head *to,
-                                 enum r5l_io_unit_state state)
-{
-       struct r5l_io_unit *io;
-
-       while (!list_empty(from)) {
-               io = list_first_entry(from, struct r5l_io_unit, log_sibling);
-               /* don't change list order */
-               if (io->state >= state)
-                       list_move_tail(&io->log_sibling, to);
-               else
-                       break;
-       }
-}
-
 static void __r5l_set_io_unit_state(struct r5l_io_unit *io,
                                    enum r5l_io_unit_state state)
 {
@@ -206,6 +191,20 @@ static void r5l_log_run_stripes(struct r5l_log *log)
        }
 }
 
+static void r5l_move_to_end_ios(struct r5l_log *log)
+{
+       struct r5l_io_unit *io, *next;
+
+       assert_spin_locked(&log->io_list_lock);
+
+       list_for_each_entry_safe(io, next, &log->running_ios, log_sibling) {
+               /* don't change list order */
+               if (io->state < IO_UNIT_IO_END)
+                       break;
+               list_move_tail(&io->log_sibling, &log->io_end_ios);
+       }
+}
+
 static void r5l_log_endio(struct bio *bio)
 {
        struct r5l_io_unit *io = bio->bi_private;
@@ -220,8 +219,7 @@ static void r5l_log_endio(struct bio *bio)
        spin_lock_irqsave(&log->io_list_lock, flags);
        __r5l_set_io_unit_state(io, IO_UNIT_IO_END);
        if (log->need_cache_flush)
-               r5l_move_io_unit_list(&log->running_ios, &log->io_end_ios,
-                                     IO_UNIT_IO_END);
+               r5l_move_to_end_ios(log);
        else
                r5l_log_run_stripes(log);
        spin_unlock_irqrestore(&log->io_list_lock, flags);