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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * mm/fadvise.c
3 *
4 * Copyright (C) 2002, Linus Torvalds
5 *
Francois Camie1f8e872008-10-15 22:01:59 -07006 * 11Jan2003 Andrew Morton
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * Initial version.
8 */
9
10#include <linux/kernel.h>
11#include <linux/file.h>
12#include <linux/fs.h>
13#include <linux/mm.h>
14#include <linux/pagemap.h>
15#include <linux/backing-dev.h>
16#include <linux/pagevec.h>
17#include <linux/fadvise.h>
Andrew Mortonebcf28e2006-03-24 03:18:04 -080018#include <linux/writeback.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/syscalls.h>
20
21#include <asm/unistd.h>
22
23/*
24 * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
25 * deactivate the pages and clear PG_Referenced.
26 */
Heiko Carstens6673e0c2009-01-14 14:14:02 +010027SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset, loff_t len, int advice)
Linus Torvalds1da177e2005-04-16 15:20:36 -070028{
29 struct file *file = fget(fd);
30 struct address_space *mapping;
31 struct backing_dev_info *bdi;
Andrew Mortonebcf28e2006-03-24 03:18:04 -080032 loff_t endbyte; /* inclusive */
Linus Torvalds1da177e2005-04-16 15:20:36 -070033 pgoff_t start_index;
34 pgoff_t end_index;
35 unsigned long nrpages;
36 int ret = 0;
37
38 if (!file)
39 return -EBADF;
40
Josef "Jeff" Sipekd3ac7f82006-12-08 02:36:44 -080041 if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {
Valentine Barshak87ba81d2006-01-08 01:03:44 -080042 ret = -ESPIPE;
43 goto out;
44 }
45
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 mapping = file->f_mapping;
47 if (!mapping || len < 0) {
48 ret = -EINVAL;
49 goto out;
50 }
51
Nick Piggin70688e42008-04-28 02:13:02 -070052 if (mapping->a_ops->get_xip_mem) {
Masatake YAMATOb5beb1c2008-02-04 22:29:31 -080053 switch (advice) {
54 case POSIX_FADV_NORMAL:
55 case POSIX_FADV_RANDOM:
56 case POSIX_FADV_SEQUENTIAL:
57 case POSIX_FADV_WILLNEED:
58 case POSIX_FADV_NOREUSE:
59 case POSIX_FADV_DONTNEED:
60 /* no bad return value, but ignore advice */
61 break;
62 default:
63 ret = -EINVAL;
64 }
Carsten Ottefe77ba62005-06-23 22:05:29 -070065 goto out;
Masatake YAMATOb5beb1c2008-02-04 22:29:31 -080066 }
Carsten Ottefe77ba62005-06-23 22:05:29 -070067
Linus Torvalds1da177e2005-04-16 15:20:36 -070068 /* Careful about overflows. Len == 0 means "as much as possible" */
69 endbyte = offset + len;
70 if (!len || endbyte < len)
71 endbyte = -1;
Andrew Mortonebcf28e2006-03-24 03:18:04 -080072 else
73 endbyte--; /* inclusive */
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75 bdi = mapping->backing_dev_info;
76
77 switch (advice) {
78 case POSIX_FADV_NORMAL:
79 file->f_ra.ra_pages = bdi->ra_pages;
Wu Fengguang01414502010-03-05 13:42:03 -080080 spin_lock(&file->f_lock);
81 file->f_mode &= ~FMODE_RANDOM;
82 spin_unlock(&file->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 break;
84 case POSIX_FADV_RANDOM:
Wu Fengguang01414502010-03-05 13:42:03 -080085 spin_lock(&file->f_lock);
86 file->f_mode |= FMODE_RANDOM;
87 spin_unlock(&file->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 break;
89 case POSIX_FADV_SEQUENTIAL:
90 file->f_ra.ra_pages = bdi->ra_pages * 2;
Wu Fengguang01414502010-03-05 13:42:03 -080091 spin_lock(&file->f_lock);
92 file->f_mode &= ~FMODE_RANDOM;
93 spin_unlock(&file->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 break;
95 case POSIX_FADV_WILLNEED:
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 /* First and last PARTIAL page! */
97 start_index = offset >> PAGE_CACHE_SHIFT;
Andrew Mortonebcf28e2006-03-24 03:18:04 -080098 end_index = endbyte >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
100 /* Careful about overflow on the "+1" */
101 nrpages = end_index - start_index + 1;
102 if (!nrpages)
103 nrpages = ~0UL;
KOSAKI Motohiro3d3727c2012-07-31 16:42:50 -0700104
105 /*
106 * Ignore return value because fadvise() shall return
107 * success even if filesystem can't retrieve a hint,
108 */
109 force_page_cache_readahead(mapping, file, start_index,
110 nrpages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 break;
Andrew Morton60c371b2006-08-05 12:14:25 -0700112 case POSIX_FADV_NOREUSE:
113 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 case POSIX_FADV_DONTNEED:
115 if (!bdi_write_congested(mapping->backing_dev_info))
Shawn Bohrerad8a1b52012-01-10 15:07:35 -0800116 __filemap_fdatawrite_range(mapping, offset, endbyte,
117 WB_SYNC_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
119 /* First and last FULL page! */
Andrew Mortonebcf28e2006-03-24 03:18:04 -0800120 start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 end_index = (endbyte >> PAGE_CACHE_SHIFT);
122
Andrew Mortonebcf28e2006-03-24 03:18:04 -0800123 if (end_index >= start_index)
124 invalidate_mapping_pages(mapping, start_index,
125 end_index);
126 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 default:
128 ret = -EINVAL;
129 }
130out:
131 fput(file);
132 return ret;
133}
Heiko Carstens6673e0c2009-01-14 14:14:02 +0100134#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
135asmlinkage long SyS_fadvise64_64(long fd, loff_t offset, loff_t len, long advice)
136{
137 return SYSC_fadvise64_64((int) fd, offset, len, (int) advice);
138}
139SYSCALL_ALIAS(sys_fadvise64_64, SyS_fadvise64_64);
140#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
142#ifdef __ARCH_WANT_SYS_FADVISE64
143
Heiko Carstens6673e0c2009-01-14 14:14:02 +0100144SYSCALL_DEFINE(fadvise64)(int fd, loff_t offset, size_t len, int advice)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145{
146 return sys_fadvise64_64(fd, offset, len, advice);
147}
Heiko Carstens6673e0c2009-01-14 14:14:02 +0100148#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
149asmlinkage long SyS_fadvise64(long fd, loff_t offset, long len, long advice)
150{
151 return SYSC_fadvise64((int) fd, offset, (size_t)len, (int)advice);
152}
153SYSCALL_ALIAS(sys_fadvise64, SyS_fadvise64);
154#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156#endif