[PATCH 16/49] writeback: reorganize mm/backing-dev.c

Tejun Heo
2015-04-06T20:23:01Z

Move wb_shutdown(), bdi_register(), bdi_register_dev(),
bdi_prune_sb(), bdi_remove_from_list() and bdi_unregister() so that
init / exit functions are grouped together. This will make updating
init / exit paths for cgroup writeback support easier.

This is pure source file reorganization.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
---
mm/backing-dev.c | 174 +++++++++++++++++++++++++++----------------------------
1 file changed, 87 insertions(+), 87 deletions(-)

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 597f0ce..ff85ecb 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -286,93 +286,6 @@ void wb_wakeup_delayed(struct bdi_writeback *wb)
}

/*
- * Remove bdi from bdi_list, and ensure that it is no longer visible
- */
-static void bdi_remove_from_list(struct backing_dev_info *bdi)
-{
- spin_lock_bh(&bdi_lock);
- list_del_rcu(&bdi->bdi_list);
- spin_unlock_bh(&bdi_lock);
-
- synchronize_rcu_expedited();
-}
-
-int bdi_register(struct backing_dev_info *bdi, struct device *parent,
- const char *fmt, ...)
-{
- va_list args;
- struct device *dev;
-
- if (bdi->dev) /* The driver needs to use separate queues per device */
- return 0;
-
- va_start(args, fmt);
- dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args);
- va_end(args);
- if (IS_ERR(dev))
- return PTR_ERR(dev);
-
- bdi->dev = dev;
-
- bdi_debug_register(bdi, dev_name(dev));
- set_bit(WB_registered, &bdi->wb.state);
-
- spin_lock_bh(&bdi_lock);
- list_add_tail_rcu(&bdi->bdi_list, &bdi_list);
- spin_unlock_bh(&bdi_lock);
-
- trace_writeback_bdi_register(bdi);
- return 0;
-}
-EXPORT_SYMBOL(bdi_register);
-
-int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev)
-{
- return bdi_register(bdi, NULL, "%u:%u", MAJOR(dev), MINOR(dev));
-}
-EXPORT_SYMBOL(bdi_register_dev);
-
-/*
- * Remove bdi from the global list and shutdown any threads we have running
- */
-static void wb_shutdown(struct bdi_writeback *wb)
-{
- /* Make sure nobody queues further work */
- spin_lock_bh(&wb->work_lock);
- if (!test_and_clear_bit(WB_registered, &wb->state)) {
- spin_unlock_bh(&wb->work_lock);
- return;
- }
- spin_unlock_bh(&wb->work_lock);
-
- /*
- * Drain work list and shutdown the delayed_work. !WB_registered
- * tells wb_workfn() that @wb is dying and its work_list needs to
- * be drained no matter what.
- */
- mod_delayed_work(bdi_wq, &wb->dwork, 0);
- flush_delayed_work(&wb->dwork);
- WARN_ON(!list_empty(&wb->work_list));
-}
-
-/*
- * Called when the device behind @bdi has been removed or ejected.
- *
- * We can't really do much here except for reducing the dirty ratio at
- * the moment. In the future we should be able to set a flag so that
- * the filesystem can handle errors at mark_inode_dirty time instead
- * of only at writeback time.
- */
-void bdi_unregister(struct backing_dev_info *bdi)
-{
- if (WARN_ON_ONCE(!bdi->dev))
- return;
-
- bdi_set_min_ratio(bdi, 0);
-}
-EXPORT_SYMBOL(bdi_unregister);
-
-/*
* Initial write bandwidth: 100 MB/s
*/
#define INIT_BW (100 << (20 - PAGE_SHIFT))
@@ -418,6 +331,29 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi)
return 0;
}

+/*
+ * Remove bdi from the global list and shutdown any threads we have running
+ */
+static void wb_shutdown(struct bdi_writeback *wb)
+{
+ /* Make sure nobody queues further work */
+ spin_lock_bh(&wb->work_lock);
+ if (!test_and_clear_bit(WB_registered, &wb->state)) {
+ spin_unlock_bh(&wb->work_lock);
+ return;
+ }
+ spin_unlock_bh(&wb->work_lock);
+
+ /*
+ * Drain work list and shutdown the delayed_work. !WB_registered
+ * tells wb_workfn() that @wb is dying and its work_list needs to
+ * be drained no matter what.
+ */
+ mod_delayed_work(bdi_wq, &wb->dwork, 0);
+ flush_delayed_work(&wb->dwork);
+ WARN_ON(!list_empty(&wb->work_list));
+}
+
static void wb_exit(struct bdi_writeback *wb)
{
int i;
@@ -449,6 +385,70 @@ int bdi_init(struct backing_dev_info *bdi)
}
EXPORT_SYMBOL(bdi_init);

+int bdi_register(struct backing_dev_info *bdi, struct device *parent,
+ const char *fmt, ...)
+{
+ va_list args;
+ struct device *dev;
+
+ if (bdi->dev) /* The driver needs to use separate queues per device */
+ return 0;
+
+ va_start(args, fmt);
+ dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args);
+ va_end(args);
+ if (IS_ERR(dev))
+ return PTR_ERR(dev);
+
+ bdi->dev = dev;
+
+ bdi_debug_register(bdi, dev_name(dev));
+ set_bit(WB_registered, &bdi->wb.state);
+
+ spin_lock_bh(&bdi_lock);
+ list_add_tail_rcu(&bdi->bdi_list, &bdi_list);
+ spin_unlock_bh(&bdi_lock);
+
+ trace_writeback_bdi_register(bdi);
+ return 0;
+}
+EXPORT_SYMBOL(bdi_register);
+
+int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev)
+{
+ return bdi_register(bdi, NULL, "%u:%u", MAJOR(dev), MINOR(dev));
+}
+EXPORT_SYMBOL(bdi_register_dev);
+
+/*
+ * Remove bdi from bdi_list, and ensure that it is no longer visible
+ */
+static void bdi_remove_from_list(struct backing_dev_info *bdi)
+{
+ spin_lock_bh(&bdi_lock);
+ list_del_rcu(&bdi->bdi_list);
+ spin_unlock_bh(&bdi_lock);
+
+ synchronize_rcu_expedited();
+}
+
+/*
+ * Called when the device behind @bdi has been removed or ejected.
+ *
+ * We can't really do much here except for reducing the dirty ratio at
+ * the moment. In the future we should be able to set a flag so that
+ * the filesystem can handle errors at mark_inode_dirty time instead
+ * of only at writeback time.
+ */
+void bdi_unregister(struct backing_dev_info *bdi)
+{
+ if (WARN_ON_ONCE(!bdi->dev))
+ return;
+
+ bdi_set_min_ratio(bdi, 0);
+}
+EXPORT_SYMBOL(bdi_unregister);
+
void bdi_destroy(struct backing_dev_info *bdi)
{
/* make sure nobody finds us on the bdi_list anymore */
--
2.1.0