mm: move page-writeback sysctls to their own file

kernel/sysctl.c is a kitchen sink where everyone leaves their dirty
dishes, this makes it very difficult to maintain.

To help with this maintenance let's start by moving sysctls to places
where they actually belong.  The proc sysctl maintainers do not want to
know what sysctl knobs you wish to add for your own piece of code, we just
care about the core logic.

So move the page-writeback sysctls to its own file.

[akpm@linux-foundation.org: coding-style cleanups]

akpm@linux-foundation.org: fix CONFIG_SYSCTL=n warnings]
Link: https://lkml.kernel.org/r/20220129012955.26594-1-zhanglianjie@uniontech.com
Signed-off-by: zhanglianjie <zhanglianjie@uniontech.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

1 files changed, 0 insertions, 15 deletions

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index fec248ab1fec..dc2b94e6a94f 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -345,28 +345,13 @@ void wb_domain_exit(struct wb_domain *dom);
 extern struct wb_domain global_wb_domain;
 
 /* These are exported to sysctl. */
-extern int dirty_background_ratio;
-extern unsigned long dirty_background_bytes;
-extern int vm_dirty_ratio;
-extern unsigned long vm_dirty_bytes;
 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 laptop_mode;
 
-int dirty_background_ratio_handler(struct ctl_table *table, int write,
-		void *buffer, size_t *lenp, loff_t *ppos);
-int dirty_background_bytes_handler(struct ctl_table *table, int write,
-		void *buffer, size_t *lenp, loff_t *ppos);
-int dirty_ratio_handler(struct ctl_table *table, int write,
-		void *buffer, size_t *lenp, loff_t *ppos);
-int dirty_bytes_handler(struct ctl_table *table, int write,
-		void *buffer, size_t *lenp, loff_t *ppos);
 int dirtytime_interval_handler(struct ctl_table *table, int write,
 		void *buffer, size_t *lenp, loff_t *ppos);
-int dirty_writeback_centisecs_handler(struct ctl_table *table, int write,
-		void *buffer, size_t *lenp, loff_t *ppos);
 
 void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
 unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh);