4 * Copyright (C) 2002, Linus Torvalds
6 * 11Jan2003 Andrew Morton
10 #include <linux/kernel.h>
11 #include <linux/file.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>
21 #include <asm/unistd.h>
24 * POSIX_FADV_WILLNEED could set PG_Referenced, and POSIX_FADV_NOREUSE could
25 * deactivate the pages and clear PG_Referenced.
27 SYSCALL_DEFINE(fadvise64_64)(int fd, loff_t offset, loff_t len, int advice)
29 struct file *file = fget(fd);
30 struct address_space *mapping;
31 struct backing_dev_info *bdi;
32 loff_t endbyte; /* inclusive */
35 unsigned long nrpages;
41 if (S_ISFIFO(file->f_path.dentry->d_inode->i_mode)) {
46 mapping = file->f_mapping;
47 if (!mapping || len < 0) {
52 if (mapping->a_ops->get_xip_mem) {
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 */
68 /* Careful about overflows. Len == 0 means "as much as possible" */
69 endbyte = offset + len;
70 if (!len || endbyte < len)
73 endbyte--; /* inclusive */
75 bdi = mapping->backing_dev_info;
78 case POSIX_FADV_NORMAL:
79 file->f_ra.ra_pages = bdi->ra_pages;
81 case POSIX_FADV_RANDOM:
82 file->f_ra.ra_pages = 0;
84 case POSIX_FADV_SEQUENTIAL:
85 file->f_ra.ra_pages = bdi->ra_pages * 2;
87 case POSIX_FADV_WILLNEED:
88 if (!mapping->a_ops->readpage) {
93 /* First and last PARTIAL page! */
94 start_index = offset >> PAGE_CACHE_SHIFT;
95 end_index = endbyte >> PAGE_CACHE_SHIFT;
97 /* Careful about overflow on the "+1" */
98 nrpages = end_index - start_index + 1;
102 ret = force_page_cache_readahead(mapping, file,
104 max_sane_readahead(nrpages));
108 case POSIX_FADV_NOREUSE:
110 case POSIX_FADV_DONTNEED:
111 if (!bdi_write_congested(mapping->backing_dev_info))
112 filemap_flush(mapping);
114 /* First and last FULL page! */
115 start_index = (offset+(PAGE_CACHE_SIZE-1)) >> PAGE_CACHE_SHIFT;
116 end_index = (endbyte >> PAGE_CACHE_SHIFT);
118 if (end_index >= start_index)
119 invalidate_mapping_pages(mapping, start_index,
129 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
130 asmlinkage long SyS_fadvise64_64(long fd, loff_t offset, loff_t len, long advice)
132 return SYSC_fadvise64_64((int) fd, offset, len, (int) advice);
134 SYSCALL_ALIAS(sys_fadvise64_64, SyS_fadvise64_64);
137 #ifdef __ARCH_WANT_SYS_FADVISE64
139 SYSCALL_DEFINE(fadvise64)(int fd, loff_t offset, size_t len, int advice)
141 return sys_fadvise64_64(fd, offset, len, advice);
143 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
144 asmlinkage long SyS_fadvise64(long fd, loff_t offset, long len, long advice)
146 return SYSC_fadvise64((int) fd, offset, (size_t)len, (int)advice);
148 SYSCALL_ALIAS(sys_fadvise64, SyS_fadvise64);