[PATCH] buffer: remove useless comment and WB_REASON_FREE_MORE_MEM, reason.

[Zhiqiang Liu]

From: Zhiqiang Liu <liuzhiqiang26@xxxxxxxxxx>

free_more_memory func has been completely removed in commit bc48f001de12
("buffer: eliminate the need to call free_more_memory() in __getblk_slow()")

So comment and `WB_REASON_FREE_MORE_MEM` reason about free_more_memory
are no longer needed.

Signed-off-by: Zhiqiang Liu <liuzhiqiang26@xxxxxxxxxx>
---
 fs/buffer.c                      | 2 +-
 include/linux/backing-dev-defs.h | 1 -
 include/trace/events/writeback.h | 1 -
 3 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index b8d28370cfd7..07ab0405f3f5 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -973,7 +973,7 @@ grow_dev_page(struct block_device *bdev, sector_t block,
 	struct page *page;
 	struct buffer_head *bh;
 	sector_t end_block;
-	int ret = 0;		/* Will call free_more_memory() */
+	int ret = 0;
 	gfp_t gfp_mask;

 	gfp_mask = mapping_gfp_constraint(inode->i_mapping, ~__GFP_FS) | gfp;
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index 4fc87dee005a..ee577a83cfe6 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -54,7 +54,6 @@ enum wb_reason {
 	WB_REASON_SYNC,
 	WB_REASON_PERIODIC,
 	WB_REASON_LAPTOP_TIMER,
-	WB_REASON_FREE_MORE_MEM,
 	WB_REASON_FS_FREE_SPACE,
 	/*
 	 * There is no bdi forker thread any more and works are done
diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h
index d94def25e4dc..85a33bea76f1 100644
--- a/include/trace/events/writeback.h
+++ b/include/trace/events/writeback.h
@@ -36,7 +36,6 @@
 	EM( WB_REASON_SYNC,			"sync")			\
 	EM( WB_REASON_PERIODIC,			"periodic")		\
 	EM( WB_REASON_LAPTOP_TIMER,		"laptop_timer")		\
-	EM( WB_REASON_FREE_MORE_MEM,		"free_more_memory")	\
 	EM( WB_REASON_FS_FREE_SPACE,		"fs_free_space")	\
 	EMe(WB_REASON_FORKER_THREAD,		"forker_thread")

-- 
2.19.1