[RFC PATCH 2/3] block_dump: remove block_dump feature

["zhangyi (F)" <yi.zhang@huawei.com>]

We have already delete block_dump feature in mark_inode_dirty() because
it can be replaced by tracepoints, now we also remove the part in
submit_bio() for the same reason. The part of block dump feature in
submit_bio() dump the write process, write region and sectors on the
target disk into kernel message. it can be replaced by
block_bio_queue tracepoint in submit_bio_checks(), so we do not need
block_dump anymore, remove the whole block_dump feature.

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
---
 block/blk-core.c          | 9 ---------
 include/linux/writeback.h | 1 -
 kernel/sysctl.c           | 8 --------
 mm/page-writeback.c       | 5 -----
 4 files changed, 23 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index fc60ff208497..9731b0ca8166 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1086,15 +1086,6 @@ blk_qc_t submit_bio(struct bio *bio)
 			task_io_account_read(bio->bi_iter.bi_size);
 			count_vm_events(PGPGIN, count);
 		}
-
-		if (unlikely(block_dump)) {
-			char b[BDEVNAME_SIZE];
-			printk(KERN_DEBUG "%s(%d): %s block %Lu on %s (%u sectors)\n",
-			current->comm, task_pid_nr(current),
-				op_is_write(bio_op(bio)) ? "WRITE" : "READ",
-				(unsigned long long)bio->bi_iter.bi_sector,
-				bio_devname(bio, b), count);
-		}
 	}
 
 	/*
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 8e5c5bb16e2d..9ef50176f3a1 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -360,7 +360,6 @@ extern unsigned int dirty_writeback_interval;
 extern unsigned int dirty_expire_interval;
 extern unsigned int dirtytime_expire_interval;
 extern int vm_highmem_is_dirtyable;
-extern int block_dump;
 extern int laptop_mode;
 
 int dirty_background_ratio_handler(struct ctl_table *table, int write,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 62fbd09b5dc1..35fce9a8402f 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2957,14 +2957,6 @@ static struct ctl_table vm_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec_jiffies,
 	},
-	{
-		.procname	= "block_dump",
-		.data		= &block_dump,
-		.maxlen		= sizeof(block_dump),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= SYSCTL_ZERO,
-	},
 	{
 		.procname	= "vfs_cache_pressure",
 		.data		= &sysctl_vfs_cache_pressure,
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index eb34d204d4ee..b72da123f242 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -108,11 +108,6 @@ EXPORT_SYMBOL_GPL(dirty_writeback_interval);
  */
 unsigned int dirty_expire_interval = 30 * 100; /* centiseconds */
 
-/*
- * Flag that makes the machine dump writes/reads and block dirtyings.
- */
-int block_dump;
-
 /*
  * Flag that puts the machine in "laptop mode". Doubles as a timeout in jiffies:
  * a full sync is triggered after this time elapses without any disk activity.
-- 
2.25.4