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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
21#include <asm/unistd.h>
22
23
24
25
26
27SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset, loff_t len, int advice)
28{
29 struct file *file = fget(fd);
30 struct address_space *mapping;
31 struct backing_dev_info *bdi;
32 loff_t endbyte;
33 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
41 if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {
42 ret = -ESPIPE;
43 goto out;
44 }
45
46 mapping = file->f_mapping;
47 if (!mapping || len < 0) {
48 ret = -EINVAL;
49 goto out;
50 }
51
52 if (mapping->a_ops->get_xip_mem) {
53 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
61 break;
62 default:
63 ret = -EINVAL;
64 }
65 goto out;
66 }
67
68
69 endbyte = offset + len;
70 if (!len || endbyte < len)
71 endbyte = -1;
72 else
73 endbyte--;
74
75 bdi = mapping->backing_dev_info;
76
77 switch (advice) {
78 case POSIX_FADV_NORMAL:
79 file->f_ra.ra_pages = bdi->ra_pages;
80 spin_lock(&file->f_lock);
81 file->f_mode &= ~FMODE_RANDOM;
82 spin_unlock(&file->f_lock);
83 break;
84 case POSIX_FADV_RANDOM:
85 spin_lock(&file->f_lock);
86 file->f_mode |= FMODE_RANDOM;
87 spin_unlock(&file->f_lock);
88 break;
89 case POSIX_FADV_SEQUENTIAL:
90 file->f_ra.ra_pages = bdi->ra_pages * 2;
91 spin_lock(&file->f_lock);
92 file->f_mode &= ~FMODE_RANDOM;
93 spin_unlock(&file->f_lock);
94 break;
95 case POSIX_FADV_WILLNEED:
96 if (!mapping->a_ops->readpage) {
97 ret = -EINVAL;
98 break;
99 }
100
101
102 start_index = offset >> PAGE_CACHE_SHIFT;
103 end_index = endbyte >> PAGE_CACHE_SHIFT;
104
105
106 nrpages = end_index - start_index + 1;
107 if (!nrpages)
108 nrpages = ~0UL;
109
110 ret = force_page_cache_readahead(mapping, file,
111 start_index,
112 nrpages);
113 if (ret > 0)
114 ret = 0;
115 break;
116 case POSIX_FADV_NOREUSE:
117 break;
118 case POSIX_FADV_DONTNEED:
119 if (!bdi_write_congested(mapping->backing_dev_info))
120 filemap_flush(mapping);
121
122
123 start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
124 end_index = (endbyte >> PAGE_CACHE_SHIFT);
125
126 if (end_index >= start_index)
127 invalidate_mapping_pages(mapping, start_index,
128 end_index);
129 break;
130 default:
131 ret = -EINVAL;
132 }
133out:
134 fput(file);
135 return ret;
136}
137#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
138asmlinkage long SyS_fadvise64_64(long fd, loff_t offset, loff_t len, long advice)
139{
140 return SYSC_fadvise64_64((int) fd, offset, len, (int) advice);
141}
142SYSCALL_ALIAS(sys_fadvise64_64, SyS_fadvise64_64);
143#endif
144
145#ifdef __ARCH_WANT_SYS_FADVISE64
146
147SYSCALL_DEFINE(fadvise64)(int fd, loff_t offset, size_t len, int advice)
148{
149 return sys_fadvise64_64(fd, offset, len, advice);
150}
151#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
152asmlinkage long SyS_fadvise64(long fd, loff_t offset, long len, long advice)
153{
154 return SYSC_fadvise64((int) fd, offset, (size_t)len, (int)advice);
155}
156SYSCALL_ALIAS(sys_fadvise64, SyS_fadvise64);
157#endif
158
159#endif
160