1 // SPDX-License-Identifier: GPL-2.0 1
2 /*
3 * Implement the manual drop-all-pagecache fun
4 */
5
6 #include <linux/pagemap.h>
7 #include <linux/kernel.h>
8 #include <linux/mm.h>
9 #include <linux/fs.h>
10 #include <linux/writeback.h>
11 #include <linux/sysctl.h>
12 #include <linux/gfp.h>
13 #include <linux/swap.h>
14 #include "internal.h"
15
16 /* A global variable is a bit ugly, but it kee
17 int sysctl_drop_caches;
18
19 static void drop_pagecache_sb(struct super_blo
20 {
21 struct inode *inode, *toput_inode = NU
22
23 spin_lock(&sb->s_inode_list_lock);
24 list_for_each_entry(inode, &sb->s_inod
25 spin_lock(&inode->i_lock);
26 /*
27 * We must skip inodes in unus
28 * inodes without pages but we
29 * we need to reschedule to av
30 */
31 if ((inode->i_state & (I_FREEI
32 (mapping_empty(inode->i_ma
33 spin_unlock(&inode->i_
34 continue;
35 }
36 __iget(inode);
37 spin_unlock(&inode->i_lock);
38 spin_unlock(&sb->s_inode_list_
39
40 invalidate_mapping_pages(inode
41 iput(toput_inode);
42 toput_inode = inode;
43
44 cond_resched();
45 spin_lock(&sb->s_inode_list_lo
46 }
47 spin_unlock(&sb->s_inode_list_lock);
48 iput(toput_inode);
49 }
50
51 int drop_caches_sysctl_handler(const struct ct
52 void *buffer, size_t *length,
53 {
54 int ret;
55
56 ret = proc_dointvec_minmax(table, writ
57 if (ret)
58 return ret;
59 if (write) {
60 static int stfu;
61
62 if (sysctl_drop_caches & 1) {
63 lru_add_drain_all();
64 iterate_supers(drop_pa
65 count_vm_event(DROP_PA
66 }
67 if (sysctl_drop_caches & 2) {
68 drop_slab();
69 count_vm_event(DROP_SL
70 }
71 if (!stfu) {
72 pr_info("%s (%d): drop
73 current->comm,
74 sysctl_drop_ca
75 }
76 stfu |= sysctl_drop_caches & 4
77 }
78 return 0;
79 }
80
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.