[PATCH 1/2] Cleanup flags handling in per-bdi flusher threads patches.

[Jan Kara]

Signed-off-by: Jan Kara <jack@xxxxxxx>
---
 fs/fs-writeback.c |   31 +++++++++++++++++--------------
 1 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index dfb4767..fc7e4a3 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -53,21 +53,24 @@ struct bdi_work {
 	unsigned long seen;
 	atomic_t pending;
 
-	unsigned long sb_data;
+	struct super_block *sb;
 	unsigned long nr_pages;
 	enum writeback_sync_modes sync_mode;
 
 	unsigned long state;
 };
 
-static struct super_block *bdi_work_sb(struct bdi_work *work)
-{
-	return (struct super_block *) (work->sb_data & ~1UL);
-}
+enum {
+	WS_USED_B = 0,
+	WS_ONSTACK_B,
+};
+
+#define WS_USED (1 << WS_USED_B)
+#define WS_ONSTACK (1 << WS_ONSTACK_B)
 
 static inline bool bdi_work_on_stack(struct bdi_work *work)
 {
-	return work->sb_data & 1UL;
+	return test_bit(WS_ONSTACK_B, &work->state);
 }
 
 static inline void bdi_work_init(struct bdi_work *work, struct super_block *sb,
@@ -75,10 +78,10 @@ static inline void bdi_work_init(struct bdi_work *work, struct super_block *sb,
 				 enum writeback_sync_modes sync_mode)
 {
 	INIT_RCU_HEAD(&work->rcu_head);
-	work->sb_data = (unsigned long) sb;
+	work->sb = sb;
 	work->nr_pages = nr_pages;
 	work->sync_mode = sync_mode;
-	work->state = 1;
+	work->state = WS_USED;
 }
 
 static inline void bdi_work_init_on_stack(struct bdi_work *work,
@@ -87,7 +90,7 @@ static inline void bdi_work_init_on_stack(struct bdi_work *work,
 					  enum writeback_sync_modes sync_mode)
 {
 	bdi_work_init(work, sb, nr_pages, sync_mode);
-	work->sb_data |= 1UL;
+	work->state |= WS_ONSTACK;
 }
 
 /**
@@ -104,9 +107,9 @@ int writeback_in_progress(struct backing_dev_info *bdi)
 
 static void bdi_work_clear(struct bdi_work *work)
 {
-	clear_bit(0, &work->state);
+	clear_bit(WS_USED_B, &work->state);
 	smp_mb__after_clear_bit();
-	wake_up_bit(&work->state, 0);
+	wake_up_bit(&work->state, WS_USED_B);
 }
 
 static void bdi_work_free(struct rcu_head *head)
@@ -215,7 +218,8 @@ static void bdi_queue_work(struct backing_dev_info *bdi, struct bdi_work *work)
  */
 static void bdi_wait_on_work_clear(struct bdi_work *work)
 {
-	wait_on_bit(&work->state, 0, bdi_sched_wait, TASK_UNINTERRUPTIBLE);
+	wait_on_bit(&work->state, WS_USED_B, bdi_sched_wait,
+		    TASK_UNINTERRUPTIBLE);
 }
 
 static struct bdi_work *bdi_alloc_work(struct super_block *sb, long nr_pages,
@@ -376,7 +380,6 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
 	long nr_pages, wrote = 0;
 
 	while ((work = get_next_work_item(bdi, wb)) != NULL) {
-		struct super_block *sb = bdi_work_sb(work);
 		enum writeback_sync_modes sync_mode;
 
 		nr_pages = work->nr_pages;
@@ -396,7 +399,7 @@ long wb_do_writeback(struct bdi_writeback *wb, int force_wait)
 		if (sync_mode == WB_SYNC_NONE)
 			wb_clear_pending(wb, work);
 
-		wrote += wb_writeback(wb, nr_pages, sb, sync_mode, 0);
+		wrote += wb_writeback(wb, nr_pages, work->sb, sync_mode, 0);
 
 		/*
 		 * This is a data integrity writeback, so only do the
-- 
1.6.0.2


--tThc/1wpZn/ma/RB
Content-Type: text/x-patch; charset=us-ascii
Content-Disposition: attachment; filename="0002-Cleanup-freeing-of-work-struct.patch"