Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Implement the manual drop-all-pagecache function |
| 3 | */ |
| 4 | |
| 5 | #include <linux/kernel.h> |
| 6 | #include <linux/mm.h> |
| 7 | #include <linux/fs.h> |
| 8 | #include <linux/writeback.h> |
| 9 | #include <linux/sysctl.h> |
| 10 | #include <linux/gfp.h> |
Al Viro | 35cf7ba | 2010-03-22 21:13:53 -0400 | [diff] [blame^] | 11 | #include "internal.h" |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 12 | |
| 13 | /* A global variable is a bit ugly, but it keeps the code simple */ |
| 14 | int sysctl_drop_caches; |
| 15 | |
| 16 | static void drop_pagecache_sb(struct super_block *sb) |
| 17 | { |
Jan Kara | eccb95c | 2008-04-29 00:59:37 -0700 | [diff] [blame] | 18 | struct inode *inode, *toput_inode = NULL; |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 19 | |
| 20 | spin_lock(&inode_lock); |
| 21 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { |
Wu Fengguang | b6fac63 | 2009-04-02 16:56:34 -0700 | [diff] [blame] | 22 | if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 23 | continue; |
Jan Kara | af065b8 | 2008-04-29 00:59:39 -0700 | [diff] [blame] | 24 | if (inode->i_mapping->nrpages == 0) |
| 25 | continue; |
Jan Kara | eccb95c | 2008-04-29 00:59:37 -0700 | [diff] [blame] | 26 | __iget(inode); |
| 27 | spin_unlock(&inode_lock); |
Mike Waychison | 2869735 | 2009-06-16 15:32:59 -0700 | [diff] [blame] | 28 | invalidate_mapping_pages(inode->i_mapping, 0, -1); |
Jan Kara | eccb95c | 2008-04-29 00:59:37 -0700 | [diff] [blame] | 29 | iput(toput_inode); |
| 30 | toput_inode = inode; |
| 31 | spin_lock(&inode_lock); |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 32 | } |
| 33 | spin_unlock(&inode_lock); |
Jan Kara | eccb95c | 2008-04-29 00:59:37 -0700 | [diff] [blame] | 34 | iput(toput_inode); |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 35 | } |
| 36 | |
Adrian Bunk | 07d45da | 2008-04-29 00:58:57 -0700 | [diff] [blame] | 37 | static void drop_pagecache(void) |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 38 | { |
Al Viro | 6754af6 | 2010-03-22 20:09:33 -0400 | [diff] [blame] | 39 | struct super_block *sb, *n; |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 40 | |
| 41 | spin_lock(&sb_lock); |
Al Viro | 6754af6 | 2010-03-22 20:09:33 -0400 | [diff] [blame] | 42 | list_for_each_entry_safe(sb, n, &super_blocks, s_list) { |
Al Viro | 551de6f | 2010-03-22 19:36:35 -0400 | [diff] [blame] | 43 | if (list_empty(&sb->s_instances)) |
| 44 | continue; |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 45 | sb->s_count++; |
| 46 | spin_unlock(&sb_lock); |
| 47 | down_read(&sb->s_umount); |
| 48 | if (sb->s_root) |
| 49 | drop_pagecache_sb(sb); |
| 50 | up_read(&sb->s_umount); |
| 51 | spin_lock(&sb_lock); |
Al Viro | 6754af6 | 2010-03-22 20:09:33 -0400 | [diff] [blame] | 52 | __put_super(sb); |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 53 | } |
| 54 | spin_unlock(&sb_lock); |
| 55 | } |
| 56 | |
Adrian Bunk | 07d45da | 2008-04-29 00:58:57 -0700 | [diff] [blame] | 57 | static void drop_slab(void) |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 58 | { |
| 59 | int nr_objects; |
| 60 | |
| 61 | do { |
| 62 | nr_objects = shrink_slab(1000, GFP_KERNEL, 1000); |
| 63 | } while (nr_objects > 10); |
| 64 | } |
| 65 | |
| 66 | int drop_caches_sysctl_handler(ctl_table *table, int write, |
Alexey Dobriyan | 8d65af7 | 2009-09-23 15:57:19 -0700 | [diff] [blame] | 67 | void __user *buffer, size_t *length, loff_t *ppos) |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 68 | { |
Alexey Dobriyan | 8d65af7 | 2009-09-23 15:57:19 -0700 | [diff] [blame] | 69 | proc_dointvec_minmax(table, write, buffer, length, ppos); |
Andrew Morton | 9d0243b | 2006-01-08 01:00:39 -0800 | [diff] [blame] | 70 | if (write) { |
| 71 | if (sysctl_drop_caches & 1) |
| 72 | drop_pagecache(); |
| 73 | if (sysctl_drop_caches & 2) |
| 74 | drop_slab(); |
| 75 | } |
| 76 | return 0; |
| 77 | } |