mirror of
https://github.com/torvalds/linux.git
synced 2025-12-07 20:06:24 +00:00
b4dbfd8653
All places were patched by coccinelle with the default expecting that ->i_lock is held, afterwards entries got fixed up by hand to use unlocked variants as needed. The script: @@ expression inode, flags; @@ - inode->i_state & flags + inode_state_read(inode) & flags @@ expression inode, flags; @@ - inode->i_state &= ~flags + inode_state_clear(inode, flags) @@ expression inode, flag1, flag2; @@ - inode->i_state &= ~flag1 & ~flag2 + inode_state_clear(inode, flag1 | flag2) @@ expression inode, flags; @@ - inode->i_state |= flags + inode_state_set(inode, flags) @@ expression inode, flags; @@ - inode->i_state = flags + inode_state_assign(inode, flags) @@ expression inode, flags; @@ - flags = inode->i_state + flags = inode_state_read(inode) @@ expression inode, flags; @@ - READ_ONCE(inode->i_state) & flags + inode_state_read(inode) & flags Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
99 lines
2.3 KiB
C
99 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Implement the manual drop-all-pagecache function
|
|
*/
|
|
|
|
#include <linux/pagemap.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/writeback.h>
|
|
#include <linux/sysctl.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/swap.h>
|
|
#include "internal.h"
|
|
|
|
/* A global variable is a bit ugly, but it keeps the code simple */
|
|
static int sysctl_drop_caches;
|
|
|
|
static void drop_pagecache_sb(struct super_block *sb, void *unused)
|
|
{
|
|
struct inode *inode, *toput_inode = NULL;
|
|
|
|
spin_lock(&sb->s_inode_list_lock);
|
|
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
|
|
spin_lock(&inode->i_lock);
|
|
/*
|
|
* We must skip inodes in unusual state. We may also skip
|
|
* inodes without pages but we deliberately won't in case
|
|
* we need to reschedule to avoid softlockups.
|
|
*/
|
|
if ((inode_state_read(inode) & (I_FREEING | I_WILL_FREE | I_NEW)) ||
|
|
(mapping_empty(inode->i_mapping) && !need_resched())) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
__iget(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&sb->s_inode_list_lock);
|
|
|
|
invalidate_mapping_pages(inode->i_mapping, 0, -1);
|
|
iput(toput_inode);
|
|
toput_inode = inode;
|
|
|
|
cond_resched();
|
|
spin_lock(&sb->s_inode_list_lock);
|
|
}
|
|
spin_unlock(&sb->s_inode_list_lock);
|
|
iput(toput_inode);
|
|
}
|
|
|
|
static int drop_caches_sysctl_handler(const struct ctl_table *table, int write,
|
|
void *buffer, size_t *length, loff_t *ppos)
|
|
{
|
|
int ret;
|
|
|
|
ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
|
|
if (ret)
|
|
return ret;
|
|
if (write) {
|
|
static int stfu;
|
|
|
|
if (sysctl_drop_caches & 1) {
|
|
lru_add_drain_all();
|
|
iterate_supers(drop_pagecache_sb, NULL);
|
|
count_vm_event(DROP_PAGECACHE);
|
|
}
|
|
if (sysctl_drop_caches & 2) {
|
|
drop_slab();
|
|
count_vm_event(DROP_SLAB);
|
|
}
|
|
if (!stfu) {
|
|
pr_info("%s (%d): drop_caches: %d\n",
|
|
current->comm, task_pid_nr(current),
|
|
sysctl_drop_caches);
|
|
}
|
|
stfu |= sysctl_drop_caches & 4;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static const struct ctl_table drop_caches_table[] = {
|
|
{
|
|
.procname = "drop_caches",
|
|
.data = &sysctl_drop_caches,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0200,
|
|
.proc_handler = drop_caches_sysctl_handler,
|
|
.extra1 = SYSCTL_ONE,
|
|
.extra2 = SYSCTL_FOUR,
|
|
},
|
|
};
|
|
|
|
static int __init init_vm_drop_caches_sysctls(void)
|
|
{
|
|
register_sysctl_init("vm", drop_caches_table);
|
|
return 0;
|
|
}
|
|
fs_initcall(init_vm_drop_caches_sysctls);
|