blk-mq: don't count completed flush data request as inflight in case of quiesce
[linux-block.git] / fs / drop_caches.c
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b2441318 1// SPDX-License-Identifier: GPL-2.0
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2/*
3 * Implement the manual drop-all-pagecache function
4 */
5
16e2df2a 6#include <linux/pagemap.h>
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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>
8a144612 13#include <linux/swap.h>
55fa6091 14#include "internal.h"
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15
16/* A global variable is a bit ugly, but it keeps the code simple */
17int sysctl_drop_caches;
18
01a05b33 19static void drop_pagecache_sb(struct super_block *sb, void *unused)
9d0243bc 20{
eccb95ce 21 struct inode *inode, *toput_inode = NULL;
9d0243bc 22
74278da9 23 spin_lock(&sb->s_inode_list_lock);
9d0243bc 24 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
250df6ed 25 spin_lock(&inode->i_lock);
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26 /*
27 * We must skip inodes in unusual state. We may also skip
28 * inodes without pages but we deliberately won't in case
29 * we need to reschedule to avoid softlockups.
30 */
250df6ed 31 if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
16e2df2a 32 (mapping_empty(inode->i_mapping) && !need_resched())) {
250df6ed 33 spin_unlock(&inode->i_lock);
af065b8a 34 continue;
250df6ed 35 }
eccb95ce 36 __iget(inode);
250df6ed 37 spin_unlock(&inode->i_lock);
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38 spin_unlock(&sb->s_inode_list_lock);
39
28697355 40 invalidate_mapping_pages(inode->i_mapping, 0, -1);
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41 iput(toput_inode);
42 toput_inode = inode;
74278da9 43
04646aeb 44 cond_resched();
74278da9 45 spin_lock(&sb->s_inode_list_lock);
9d0243bc 46 }
74278da9 47 spin_unlock(&sb->s_inode_list_lock);
eccb95ce 48 iput(toput_inode);
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49}
50
1f7e0616 51int drop_caches_sysctl_handler(struct ctl_table *table, int write,
32927393 52 void *buffer, size_t *length, loff_t *ppos)
9d0243bc 53{
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54 int ret;
55
56 ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
57 if (ret)
58 return ret;
9d0243bc 59 if (write) {
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60 static int stfu;
61
62 if (sysctl_drop_caches & 1) {
8a144612 63 lru_add_drain_all();
01a05b33 64 iterate_supers(drop_pagecache_sb, NULL);
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65 count_vm_event(DROP_PAGECACHE);
66 }
67 if (sysctl_drop_caches & 2) {
9d0243bc 68 drop_slab();
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69 count_vm_event(DROP_SLAB);
70 }
71 if (!stfu) {
72 pr_info("%s (%d): drop_caches: %d\n",
73 current->comm, task_pid_nr(current),
74 sysctl_drop_caches);
75 }
76 stfu |= sysctl_drop_caches & 4;
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77 }
78 return 0;
79}