[PATCH 10/14] mm,sysctl: remove proc input checks out of sysctl handlers

From: Sasha Levin
Date: Sun Apr 29 2012 - 02:45:50 EST


Simplify sysctl handler by removing user input checks and using the callback
provided by the sysctl table.

Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
include/linux/mmzone.h | 15 ++++---------
include/linux/writeback.h | 19 ++++-------------
kernel/sysctl.c | 30 ++++++++++++++++++---------
mm/page-writeback.c | 48 ++++++++++++--------------------------------
mm/page_alloc.c | 37 ++++++----------------------------
5 files changed, 50 insertions(+), 99 deletions(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 5c4880b..52fc184 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -824,17 +824,12 @@ static inline int is_dma(struct zone *zone)

/* These two functions are used to setup the per zone pages min values */
struct ctl_table;
-int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
- void __user *, size_t *, loff_t *);
+int min_free_kbytes_sysctl_handler(void);
extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
-int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
- void __user *, size_t *, loff_t *);
-int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
- void __user *, size_t *, loff_t *);
-int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
- void __user *, size_t *, loff_t *);
-int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
- void __user *, size_t *, loff_t *);
+int lowmem_reserve_ratio_sysctl_handler(void);
+int percpu_pagelist_fraction_sysctl_handler(void);
+int sysctl_min_unmapped_ratio_sysctl_handler(void);
+int sysctl_min_slab_ratio_sysctl_handler(void);

extern int numa_zonelist_order_handler(struct ctl_table *, int,
void __user *, size_t *, loff_t *);
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 3309736..9081cf1 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -137,22 +137,13 @@ extern int vm_highmem_is_dirtyable;
extern int block_dump;
extern int laptop_mode;

-extern int dirty_background_ratio_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos);
-extern int dirty_background_bytes_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos);
-extern int dirty_ratio_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos);
-extern int dirty_bytes_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos);
+extern int dirty_background_ratio_handler(void);
+extern int dirty_background_bytes_handler(void);
+extern int dirty_ratio_handler(void);
+extern int dirty_bytes_handler(void);

struct ctl_table;
-int dirty_writeback_centisecs_handler(struct ctl_table *, int,
- void __user *, size_t *, loff_t *);
+int dirty_writeback_centisecs_handler(void);

void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty);
unsigned long bdi_dirty_limit(struct backing_dev_info *bdi,
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index eef7508..3c403fd 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1055,7 +1055,8 @@ static struct ctl_table vm_table[] = {
.data = &dirty_background_ratio,
.maxlen = sizeof(dirty_background_ratio),
.mode = 0644,
- .proc_handler = dirty_background_ratio_handler,
+ .proc_handler = proc_dointvec_minmax,
+ .callback = dirty_background_ratio_handler,
.extra1 = &zero,
.extra2 = &one_hundred,
},
@@ -1064,7 +1065,8 @@ static struct ctl_table vm_table[] = {
.data = &dirty_background_bytes,
.maxlen = sizeof(dirty_background_bytes),
.mode = 0644,
- .proc_handler = dirty_background_bytes_handler,
+ .proc_handler = proc_doulongvec_minmax,
+ .callback = dirty_background_bytes_handler,
.extra1 = &one_ul,
},
{
@@ -1072,7 +1074,8 @@ static struct ctl_table vm_table[] = {
.data = &vm_dirty_ratio,
.maxlen = sizeof(vm_dirty_ratio),
.mode = 0644,
- .proc_handler = dirty_ratio_handler,
+ .proc_handler = proc_dointvec_minmax,
+ .callback = dirty_ratio_handler,
.extra1 = &zero,
.extra2 = &one_hundred,
},
@@ -1081,7 +1084,8 @@ static struct ctl_table vm_table[] = {
.data = &vm_dirty_bytes,
.maxlen = sizeof(vm_dirty_bytes),
.mode = 0644,
- .proc_handler = dirty_bytes_handler,
+ .proc_handler = proc_doulongvec_minmax,
+ .callback = dirty_bytes_handler,
.extra1 = &dirty_bytes_min,
},
{
@@ -1089,7 +1093,8 @@ static struct ctl_table vm_table[] = {
.data = &dirty_writeback_interval,
.maxlen = sizeof(dirty_writeback_interval),
.mode = 0644,
- .proc_handler = dirty_writeback_centisecs_handler,
+ .proc_handler = proc_dointvec,
+ .callback = dirty_writeback_centisecs_handler,
},
{
.procname = "dirty_expire_centisecs",
@@ -1165,7 +1170,8 @@ static struct ctl_table vm_table[] = {
.data = &sysctl_lowmem_reserve_ratio,
.maxlen = sizeof(sysctl_lowmem_reserve_ratio),
.mode = 0644,
- .proc_handler = lowmem_reserve_ratio_sysctl_handler,
+ .proc_handler = proc_dointvec_minmax,
+ .callback = lowmem_reserve_ratio_sysctl_handler,
},
{
.procname = "drop_caches",
@@ -1200,7 +1206,8 @@ static struct ctl_table vm_table[] = {
.data = &min_free_kbytes,
.maxlen = sizeof(min_free_kbytes),
.mode = 0644,
- .proc_handler = min_free_kbytes_sysctl_handler,
+ .proc_handler = proc_dointvec,
+ .callback = min_free_kbytes_sysctl_handler,
.extra1 = &zero,
},
{
@@ -1208,7 +1215,8 @@ static struct ctl_table vm_table[] = {
.data = &percpu_pagelist_fraction,
.maxlen = sizeof(percpu_pagelist_fraction),
.mode = 0644,
- .proc_handler = percpu_pagelist_fraction_sysctl_handler,
+ .proc_handler = proc_dointvec_minmax,
+ .callback = percpu_pagelist_fraction_sysctl_handler,
.extra1 = &min_percpu_pagelist_fract,
},
#ifdef CONFIG_MMU
@@ -1277,7 +1285,8 @@ static struct ctl_table vm_table[] = {
.data = &sysctl_min_unmapped_ratio,
.maxlen = sizeof(sysctl_min_unmapped_ratio),
.mode = 0644,
- .proc_handler = sysctl_min_unmapped_ratio_sysctl_handler,
+ .proc_handler = proc_dointvec_minmax,
+ .callback = sysctl_min_unmapped_ratio_sysctl_handler,
.extra1 = &zero,
.extra2 = &one_hundred,
},
@@ -1286,7 +1295,8 @@ static struct ctl_table vm_table[] = {
.data = &sysctl_min_slab_ratio,
.maxlen = sizeof(sysctl_min_slab_ratio),
.mode = 0644,
- .proc_handler = sysctl_min_slab_ratio_sysctl_handler,
+ .proc_handler = proc_dointvec_minmax,
+ .callback = sysctl_min_slab_ratio_sysctl_handler,
.extra1 = &zero,
.extra2 = &one_hundred,
},
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 9dec97f..3898114 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -350,58 +350,38 @@ static void update_completion_period(void)
writeback_set_ratelimit();
}

-int dirty_background_ratio_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
+int dirty_background_ratio_handler(void)
{
- int ret;
-
- ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
- if (ret == 0 && write)
- dirty_background_bytes = 0;
- return ret;
+ dirty_background_bytes = 0;
+ return 0;
}

-int dirty_background_bytes_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
+int dirty_background_bytes_handler(void)
{
- int ret;
-
- ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
- if (ret == 0 && write)
- dirty_background_ratio = 0;
- return ret;
+ dirty_background_ratio = 0;
+ return 0;
}

-int dirty_ratio_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
+int dirty_ratio_handler(void)
{
int old_ratio = vm_dirty_ratio;
- int ret;

- ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
- if (ret == 0 && write && vm_dirty_ratio != old_ratio) {
+ if (vm_dirty_ratio != old_ratio) {
update_completion_period();
vm_dirty_bytes = 0;
}
- return ret;
+ return 0;
}

-int dirty_bytes_handler(struct ctl_table *table, int write,
- void __user *buffer, size_t *lenp,
- loff_t *ppos)
+int dirty_bytes_handler(void)
{
unsigned long old_bytes = vm_dirty_bytes;
- int ret;

- ret = proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
- if (ret == 0 && write && vm_dirty_bytes != old_bytes) {
+ if (vm_dirty_bytes != old_bytes) {
update_completion_period();
vm_dirty_ratio = 0;
}
- return ret;
+ return 0;
}

/*
@@ -1500,10 +1480,8 @@ void throttle_vm_writeout(gfp_t gfp_mask)
/*
* sysctl handler for /proc/sys/vm/dirty_writeback_centisecs
*/
-int dirty_writeback_centisecs_handler(ctl_table *table, int write,
- void __user *buffer, size_t *length, loff_t *ppos)
+int dirty_writeback_centisecs_handler(void)
{
- proc_dointvec(table, write, buffer, length, ppos);
bdi_arm_supers_timer();
return 0;
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1b951de..1638fc1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5193,29 +5193,19 @@ int __meminit init_per_zone_wmark_min(void)
module_init(init_per_zone_wmark_min)

/*
- * min_free_kbytes_sysctl_handler - just a wrapper around proc_dointvec() so
- * that we can call two helper functions whenever min_free_kbytes
+ * min_free_kbytes_sysctl_handler - called whenever min_free_kbytes
* changes.
*/
-int min_free_kbytes_sysctl_handler(ctl_table *table, int write,
- void __user *buffer, size_t *length, loff_t *ppos)
+int min_free_kbytes_sysctl_handler(void)
{
- proc_dointvec(table, write, buffer, length, ppos);
- if (write)
- setup_per_zone_wmarks();
+ setup_per_zone_wmarks();
return 0;
}

#ifdef CONFIG_NUMA
-int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
- void __user *buffer, size_t *length, loff_t *ppos)
+int sysctl_min_unmapped_ratio_sysctl_handler(void)
{
struct zone *zone;
- int rc;
-
- rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
- if (rc)
- return rc;

for_each_zone(zone)
zone->min_unmapped_pages = (zone->present_pages *
@@ -5223,15 +5213,9 @@ int sysctl_min_unmapped_ratio_sysctl_handler(ctl_table *table, int write,
return 0;
}

-int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
- void __user *buffer, size_t *length, loff_t *ppos)
+int sysctl_min_slab_ratio_sysctl_handler(void)
{
struct zone *zone;
- int rc;
-
- rc = proc_dointvec_minmax(table, write, buffer, length, ppos);
- if (rc)
- return rc;

for_each_zone(zone)
zone->min_slab_pages = (zone->present_pages *
@@ -5249,10 +5233,8 @@ int sysctl_min_slab_ratio_sysctl_handler(ctl_table *table, int write,
* minimum watermarks. The lowmem reserve ratio can only make sense
* if in function of the boot time zone sizes.
*/
-int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
- void __user *buffer, size_t *length, loff_t *ppos)
+int lowmem_reserve_ratio_sysctl_handler(void)
{
- proc_dointvec_minmax(table, write, buffer, length, ppos);
setup_per_zone_lowmem_reserve();
return 0;
}
@@ -5263,16 +5245,11 @@ int lowmem_reserve_ratio_sysctl_handler(ctl_table *table, int write,
* can have before it gets flushed back to buddy allocator.
*/

-int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
- void __user *buffer, size_t *length, loff_t *ppos)
+int percpu_pagelist_fraction_sysctl_handler(void)
{
struct zone *zone;
unsigned int cpu;
- int ret;

- ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
- if (!write || (ret == -EINVAL))
- return ret;
for_each_populated_zone(zone) {
for_each_possible_cpu(cpu) {
unsigned long high;
--
1.7.8.5

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