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1/*
2 * mm/fadvise.c
3 *
4 * Copyright (C) 2002, Linus Torvalds
5 *
6 * 11Jan2003 Andrew Morton
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>
18#include <linux/writeback.h>
19#include <linux/syscalls.h>
20#include <linux/swap.h>
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 */
28SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
29{
30 struct fd f = fdget(fd);
31 struct inode *inode;
32 struct address_space *mapping;
33 struct backing_dev_info *bdi;
34 loff_t endbyte; /* inclusive */
35 pgoff_t start_index;
36 pgoff_t end_index;
37 unsigned long nrpages;
38 int ret = 0;
39
40 if (!f.file)
41 return -EBADF;
42
43 inode = file_inode(f.file);
44 if (S_ISFIFO(inode->i_mode)) {
45 ret = -ESPIPE;
46 goto out;
47 }
48
49 mapping = f.file->f_mapping;
50 if (!mapping || len < 0) {
51 ret = -EINVAL;
52 goto out;
53 }
54
55 if (IS_DAX(inode)) {
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 }
68 goto out;
69 }
70
71 /* Careful about overflows. Len == 0 means "as much as possible" */
72 endbyte = offset + len;
73 if (!len || endbyte < len)
74 endbyte = -1;
75 else
76 endbyte--; /* inclusive */
77
78 bdi = inode_to_bdi(mapping->host);
79
80 switch (advice) {
81 case POSIX_FADV_NORMAL:
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);
86 break;
87 case POSIX_FADV_RANDOM:
88 spin_lock(&f.file->f_lock);
89 f.file->f_mode |= FMODE_RANDOM;
90 spin_unlock(&f.file->f_lock);
91 break;
92 case POSIX_FADV_SEQUENTIAL:
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);
97 break;
98 case POSIX_FADV_WILLNEED:
99 /* First and last PARTIAL page! */
100 start_index = offset >> PAGE_SHIFT;
101 end_index = endbyte >> PAGE_SHIFT;
102
103 /* Careful about overflow on the "+1" */
104 nrpages = end_index - start_index + 1;
105 if (!nrpages)
106 nrpages = ~0UL;
107
108 /*
109 * Ignore return value because fadvise() shall return
110 * success even if filesystem can't retrieve a hint,
111 */
112 force_page_cache_readahead(mapping, f.file, start_index,
113 nrpages);
114 break;
115 case POSIX_FADV_NOREUSE:
116 break;
117 case POSIX_FADV_DONTNEED:
118 if (!inode_write_congested(mapping->host))
119 __filemap_fdatawrite_range(mapping, offset, endbyte,
120 WB_SYNC_NONE);
121
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 */
127 start_index = (offset+(PAGE_SIZE-1)) >> PAGE_SHIFT;
128 end_index = (endbyte >> PAGE_SHIFT);
129
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,
143 end_index);
144 }
145 }
146 break;
147 default:
148 ret = -EINVAL;
149 }
150out:
151 fdput(f);
152 return ret;
153}
154
155#ifdef __ARCH_WANT_SYS_FADVISE64
156
157SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
158{
159 return sys_fadvise64_64(fd, offset, len, advice);
160}
161
162#endif
1/*
2 * mm/fadvise.c
3 *
4 * Copyright (C) 2002, Linus Torvalds
5 *
6 * 11Jan2003 Andrew Morton
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>
18#include <linux/writeback.h>
19#include <linux/syscalls.h>
20#include <linux/swap.h>
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 */
28SYSCALL_DEFINE4(fadvise64_64, int, fd, loff_t, offset, loff_t, len, int, advice)
29{
30 struct fd f = fdget(fd);
31 struct address_space *mapping;
32 struct backing_dev_info *bdi;
33 loff_t endbyte; /* inclusive */
34 pgoff_t start_index;
35 pgoff_t end_index;
36 unsigned long nrpages;
37 int ret = 0;
38
39 if (!f.file)
40 return -EBADF;
41
42 if (S_ISFIFO(file_inode(f.file)->i_mode)) {
43 ret = -ESPIPE;
44 goto out;
45 }
46
47 mapping = f.file->f_mapping;
48 if (!mapping || len < 0) {
49 ret = -EINVAL;
50 goto out;
51 }
52
53 if (mapping->a_ops->get_xip_mem) {
54 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 }
66 goto out;
67 }
68
69 /* Careful about overflows. Len == 0 means "as much as possible" */
70 endbyte = offset + len;
71 if (!len || endbyte < len)
72 endbyte = -1;
73 else
74 endbyte--; /* inclusive */
75
76 bdi = mapping->backing_dev_info;
77
78 switch (advice) {
79 case POSIX_FADV_NORMAL:
80 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);
84 break;
85 case POSIX_FADV_RANDOM:
86 spin_lock(&f.file->f_lock);
87 f.file->f_mode |= FMODE_RANDOM;
88 spin_unlock(&f.file->f_lock);
89 break;
90 case POSIX_FADV_SEQUENTIAL:
91 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);
95 break;
96 case POSIX_FADV_WILLNEED:
97 /* First and last PARTIAL page! */
98 start_index = offset >> PAGE_CACHE_SHIFT;
99 end_index = endbyte >> PAGE_CACHE_SHIFT;
100
101 /* Careful about overflow on the "+1" */
102 nrpages = end_index - start_index + 1;
103 if (!nrpages)
104 nrpages = ~0UL;
105
106 /*
107 * Ignore return value because fadvise() shall return
108 * success even if filesystem can't retrieve a hint,
109 */
110 force_page_cache_readahead(mapping, f.file, start_index,
111 nrpages);
112 break;
113 case POSIX_FADV_NOREUSE:
114 break;
115 case POSIX_FADV_DONTNEED:
116 if (!bdi_write_congested(mapping->backing_dev_info))
117 __filemap_fdatawrite_range(mapping, offset, endbyte,
118 WB_SYNC_NONE);
119
120 /* First and last FULL page! */
121 start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
122 end_index = (endbyte >> PAGE_CACHE_SHIFT);
123
124 if (end_index >= start_index) {
125 unsigned long count = invalidate_mapping_pages(mapping,
126 start_index, end_index);
127
128 /*
129 * If fewer pages were invalidated than expected then
130 * it is possible that some of the pages were on
131 * a per-cpu pagevec for a remote CPU. Drain all
132 * pagevecs and try again.
133 */
134 if (count < (end_index - start_index + 1)) {
135 lru_add_drain_all();
136 invalidate_mapping_pages(mapping, start_index,
137 end_index);
138 }
139 }
140 break;
141 default:
142 ret = -EINVAL;
143 }
144out:
145 fdput(f);
146 return ret;
147}
148
149#ifdef __ARCH_WANT_SYS_FADVISE64
150
151SYSCALL_DEFINE4(fadvise64, int, fd, loff_t, offset, size_t, len, int, advice)
152{
153 return sys_fadvise64_64(fd, offset, len, advice);
154}
155
156#endif