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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>
Mel Gorman67d46b22013-02-22 16:35:59 -080020#include <linux/swap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
22#include <asm/unistd.h>
23
24/*
25 * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
26 * deactivate the pages and clear PG_Referenced.
27 */
Al Viro4a0fd5b2013-01-21 15:16:58 -050028SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029{
Al Viro2903ff02012-08-28 12:52:22 -040030 struct fd f = fdget(fd);
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 struct address_space *mapping;
32 struct backing_dev_info *bdi;
Andrew Mortonebcf28e2006-03-24 03:18:04 -080033 loff_t endbyte; /* inclusive */
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 pgoff_t start_index;
35 pgoff_t end_index;
36 unsigned long nrpages;
37 int ret = 0;
38
Al Viro2903ff02012-08-28 12:52:22 -040039 if (!f.file)
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 return -EBADF;
41
Al Viro496ad9a2013-01-23 17:07:38 -050042 if (S_ISFIFO(file_inode(f.file)->i_mode)) {
Valentine Barshak87ba81d2006-01-08 01:03:44 -080043 ret = -ESPIPE;
44 goto out;
45 }
46
Al Viro2903ff02012-08-28 12:52:22 -040047 mapping = f.file->f_mapping;
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 if (!mapping || len < 0) {
49 ret = -EINVAL;
50 goto out;
51 }
52
Nick Piggin70688e42008-04-28 02:13:02 -070053 if (mapping->a_ops->get_xip_mem) {
Masatake YAMATOb5beb1c2008-02-04 22:29:31 -080054 switch (advice) {
55 case POSIX_FADV_NORMAL:
56 case POSIX_FADV_RANDOM:
57 case POSIX_FADV_SEQUENTIAL:
58 case POSIX_FADV_WILLNEED:
59 case POSIX_FADV_NOREUSE:
60 case POSIX_FADV_DONTNEED:
61 /* no bad return value, but ignore advice */
62 break;
63 default:
64 ret = -EINVAL;
65 }
Carsten Ottefe77ba62005-06-23 22:05:29 -070066 goto out;
Masatake YAMATOb5beb1c2008-02-04 22:29:31 -080067 }
Carsten Ottefe77ba62005-06-23 22:05:29 -070068
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 /* Careful about overflows. Len == 0 means "as much as possible" */
70 endbyte = offset + len;
71 if (!len || endbyte < len)
72 endbyte = -1;
Andrew Mortonebcf28e2006-03-24 03:18:04 -080073 else
74 endbyte--; /* inclusive */
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76 bdi = mapping->backing_dev_info;
77
78 switch (advice) {
79 case POSIX_FADV_NORMAL:
Al Viro2903ff02012-08-28 12:52:22 -040080 f.file->f_ra.ra_pages = bdi->ra_pages;
81 spin_lock(&f.file->f_lock);
82 f.file->f_mode &= ~FMODE_RANDOM;
83 spin_unlock(&f.file->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 break;
85 case POSIX_FADV_RANDOM:
Al Viro2903ff02012-08-28 12:52:22 -040086 spin_lock(&f.file->f_lock);
87 f.file->f_mode |= FMODE_RANDOM;
88 spin_unlock(&f.file->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 break;
90 case POSIX_FADV_SEQUENTIAL:
Al Viro2903ff02012-08-28 12:52:22 -040091 f.file->f_ra.ra_pages = bdi->ra_pages * 2;
92 spin_lock(&f.file->f_lock);
93 f.file->f_mode &= ~FMODE_RANDOM;
94 spin_unlock(&f.file->f_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 break;
96 case POSIX_FADV_WILLNEED:
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 /* First and last PARTIAL page! */
98 start_index = offset >> PAGE_CACHE_SHIFT;
Andrew Mortonebcf28e2006-03-24 03:18:04 -080099 end_index = endbyte >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101 /* Careful about overflow on the "+1" */
102 nrpages = end_index - start_index + 1;
103 if (!nrpages)
104 nrpages = ~0UL;
KOSAKI Motohiro3d3727c2012-07-31 16:42:50 -0700105
106 /*
107 * Ignore return value because fadvise() shall return
108 * success even if filesystem can't retrieve a hint,
109 */
Al Viro2903ff02012-08-28 12:52:22 -0400110 force_page_cache_readahead(mapping, f.file, start_index,
KOSAKI Motohiro3d3727c2012-07-31 16:42:50 -0700111 nrpages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 break;
Andrew Morton60c371b2006-08-05 12:14:25 -0700113 case POSIX_FADV_NOREUSE:
114 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 case POSIX_FADV_DONTNEED:
116 if (!bdi_write_congested(mapping->backing_dev_info))
Shawn Bohrerad8a1b52012-01-10 15:07:35 -0800117 __filemap_fdatawrite_range(mapping, offset, endbyte,
118 WB_SYNC_NONE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Mel Gorman441c2282014-12-12 16:56:33 -0800120 /*
121 * First and last FULL page! Partial pages are deliberately
122 * preserved on the expectation that it is better to preserve
123 * needed memory than to discard unneeded memory.
124 */
Andrew Mortonebcf28e2006-03-24 03:18:04 -0800125 start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 end_index = (endbyte >> PAGE_CACHE_SHIFT);
127
Mel Gorman67d46b22013-02-22 16:35:59 -0800128 if (end_index >= start_index) {
129 unsigned long count = invalidate_mapping_pages(mapping,
130 start_index, end_index);
131
132 /*
133 * If fewer pages were invalidated than expected then
134 * it is possible that some of the pages were on
135 * a per-cpu pagevec for a remote CPU. Drain all
136 * pagevecs and try again.
137 */
138 if (count < (end_index - start_index + 1)) {
139 lru_add_drain_all();
140 invalidate_mapping_pages(mapping, start_index,
Andrew Mortonebcf28e2006-03-24 03:18:04 -0800141 end_index);
Mel Gorman67d46b22013-02-22 16:35:59 -0800142 }
143 }
Andrew Mortonebcf28e2006-03-24 03:18:04 -0800144 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 default:
146 ret = -EINVAL;
147 }
148out:
Al Viro2903ff02012-08-28 12:52:22 -0400149 fdput(f);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 return ret;
151}
152
153#ifdef __ARCH_WANT_SYS_FADVISE64
154
Al Viro4a0fd5b2013-01-21 15:16:58 -0500155SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156{
157 return sys_fadvise64_64(fd, offset, len, advice);
158}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
160#endif