block_dump: remove block_dump feature

mainline inclusion
from mainline-v5.14
commit 3af3d772
category: bugfix
bugzilla: 172159 https://gitee.com/openeuler/kernel/issues/I4CZ4C
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3af3d772f7216cf23081bb4176e86f1219d32ebc

-----------------------------------------------

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: Nzhangyi (F) <yi.zhang@huawei.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210313030146.2882027-3-yi.zhang@huawei.comSigned-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NYe Bin <yebin10@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

block/blk-core.c

@@ -1098,15 +1098,6 @@ 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);
-		}
 	}
 
 	/*

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,

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,

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.