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CommitLineData
1da177e4
LT
1/*
2 * mm/fadvise.c
3 *
4 * Copyright (C) 2002, Linus Torvalds
5 *
e1f8e874 6 * 11Jan2003 Andrew Morton
1da177e4
LT
7 * 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>
ebcf28e1 18#include <linux/writeback.h>
1da177e4 19#include <linux/syscalls.h>
67d46b29 20#include <linux/swap.h>
1da177e4
LT
21
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 */
4a0fd5bf 28SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
1da177e4 29{
2903ff01 30 struct fd f = fdget(fd);
e748dcd0 31 struct inode *inode;
1da177e4
LT
32 struct address_space *mapping;
33 struct backing_dev_info *bdi;
ebcf28e1 34 loff_t endbyte; /* inclusive */
1da177e4
LT
35 pgoff_t start_index;
36 pgoff_t end_index;
37 unsigned long nrpages;
38 int ret = 0;
39
2903ff01 40 if (!f.file)
1da177e4
LT
41 return -EBADF;
42
e748dcd0
MW
43 inode = file_inode(f.file);
44 if (S_ISFIFO(inode->i_mode)) {
87ba81db
VB
45 ret = -ESPIPE;
46 goto out;
47 }
48
2903ff01 49 mapping = f.file->f_mapping;
1da177e4
LT
50 if (!mapping || len < 0) {
51 ret = -EINVAL;
52 goto out;
53 }
54
e748dcd0 55 if (IS_DAX(inode)) {
b5beb1ca
MY
56 switch (advice) {
57 case POSIX_FADV_NORMAL:
58 case POSIX_FADV_RANDOM:
59 case POSIX_FADV_SEQUENTIAL:
60 case POSIX_FADV_WILLNEED:
61 case POSIX_FADV_NOREUSE:
62 case POSIX_FADV_DONTNEED:
63 /* no bad return value, but ignore advice */
64 break;
65 default:
66 ret = -EINVAL;
67 }
fe77ba6f 68 goto out;
b5beb1ca 69 }
fe77ba6f 70
1da177e4
LT
71 /* Careful about overflows. Len == 0 means "as much as possible" */
72 endbyte = offset + len;
73 if (!len || endbyte < len)
74 endbyte = -1;
ebcf28e1
AM
75 else
76 endbyte--; /* inclusive */
1da177e4 77
de1414a6 78 bdi = inode_to_bdi(mapping->host);
1da177e4
LT
79
80 switch (advice) {
81 case POSIX_FADV_NORMAL:
2903ff01
AV
82 f.file->f_ra.ra_pages = bdi->ra_pages;
83 spin_lock(&f.file->f_lock);
84 f.file->f_mode &= ~FMODE_RANDOM;
85 spin_unlock(&f.file->f_lock);
1da177e4
LT
86 break;
87 case POSIX_FADV_RANDOM:
2903ff01
AV
88 spin_lock(&f.file->f_lock);
89 f.file->f_mode |= FMODE_RANDOM;
90 spin_unlock(&f.file->f_lock);
1da177e4
LT
91 break;
92 case POSIX_FADV_SEQUENTIAL:
2903ff01
AV
93 f.file->f_ra.ra_pages = bdi->ra_pages * 2;
94 spin_lock(&f.file->f_lock);
95 f.file->f_mode &= ~FMODE_RANDOM;
96 spin_unlock(&f.file->f_lock);
1da177e4
LT
97 break;
98 case POSIX_FADV_WILLNEED:
1da177e4
LT
99 /* First and last PARTIAL page! */
100 start_index = offset >> PAGE_CACHE_SHIFT;
ebcf28e1 101 end_index = endbyte >> PAGE_CACHE_SHIFT;
1da177e4
LT
102
103 /* Careful about overflow on the "+1" */
104 nrpages = end_index - start_index + 1;
105 if (!nrpages)
106 nrpages = ~0UL;
3d3727cd
KM
107
108 /*
109 * Ignore return value because fadvise() shall return
110 * success even if filesystem can't retrieve a hint,
111 */
2903ff01 112 force_page_cache_readahead(mapping, f.file, start_index,
3d3727cd 113 nrpages);
1da177e4 114 break;
60c371bc
AM
115 case POSIX_FADV_NOREUSE:
116 break;
1da177e4 117 case POSIX_FADV_DONTNEED:
703c2708 118 if (!inode_write_congested(mapping->host))
ad8a1b55
SB
119 __filemap_fdatawrite_range(mapping, offset, endbyte,
120 WB_SYNC_NONE);
1da177e4 121
441c228f
MG
122 /*
123 * First and last FULL page! Partial pages are deliberately
124 * preserved on the expectation that it is better to preserve
125 * needed memory than to discard unneeded memory.
126 */
ebcf28e1 127 start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
1da177e4
LT
128 end_index = (endbyte >> PAGE_CACHE_SHIFT);
129
67d46b29
MG
130 if (end_index >= start_index) {
131 unsigned long count = invalidate_mapping_pages(mapping,
132 start_index, end_index);
133
134 /*
135 * If fewer pages were invalidated than expected then
136 * it is possible that some of the pages were on
137 * a per-cpu pagevec for a remote CPU. Drain all
138 * pagevecs and try again.
139 */
140 if (count < (end_index - start_index + 1)) {
141 lru_add_drain_all();
142 invalidate_mapping_pages(mapping, start_index,
ebcf28e1 143 end_index);
67d46b29
MG
144 }
145 }
ebcf28e1 146 break;
1da177e4
LT
147 default:
148 ret = -EINVAL;
149 }
150out:
2903ff01 151 fdput(f);
1da177e4
LT
152 return ret;
153}
154
155#ifdef __ARCH_WANT_SYS_FADVISE64
156
4a0fd5bf 157SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
1da177e4
LT
158{
159 return sys_fadvise64_64(fd, offset, len, advice);
160}
161
162#endif