mm: move readahead syscall to mm/readahead.c
It is better to define readahead(2) in mm/readahead.c than in mm/filemap.c. Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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39
mm/filemap.c
39
mm/filemap.c
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@ -29,7 +29,6 @@
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#include <linux/pagevec.h>
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#include <linux/blkdev.h>
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#include <linux/security.h>
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#include <linux/syscalls.h>
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#include <linux/cpuset.h>
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#include <linux/hardirq.h> /* for BUG_ON(!in_atomic()) only */
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#include <linux/memcontrol.h>
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@ -1478,44 +1477,6 @@ out:
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}
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EXPORT_SYMBOL(generic_file_aio_read);
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static ssize_t
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do_readahead(struct address_space *mapping, struct file *filp,
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pgoff_t index, unsigned long nr)
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{
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if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
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return -EINVAL;
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force_page_cache_readahead(mapping, filp, index, nr);
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return 0;
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}
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SYSCALL_DEFINE(readahead)(int fd, loff_t offset, size_t count)
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{
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ssize_t ret;
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struct file *file;
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ret = -EBADF;
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file = fget(fd);
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if (file) {
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if (file->f_mode & FMODE_READ) {
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struct address_space *mapping = file->f_mapping;
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pgoff_t start = offset >> PAGE_CACHE_SHIFT;
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pgoff_t end = (offset + count - 1) >> PAGE_CACHE_SHIFT;
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unsigned long len = end - start + 1;
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ret = do_readahead(mapping, file, start, len);
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}
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fput(file);
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}
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return ret;
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}
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#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
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asmlinkage long SyS_readahead(long fd, loff_t offset, long count)
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{
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return SYSC_readahead((int) fd, offset, (size_t) count);
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}
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SYSCALL_ALIAS(sys_readahead, SyS_readahead);
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#endif
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#ifdef CONFIG_MMU
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/**
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* page_cache_read - adds requested page to the page cache if not already there
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@ -17,6 +17,8 @@
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#include <linux/task_io_accounting_ops.h>
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#include <linux/pagevec.h>
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#include <linux/pagemap.h>
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#include <linux/syscalls.h>
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#include <linux/file.h>
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/*
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* Initialise a struct file's readahead state. Assumes that the caller has
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@ -562,3 +564,41 @@ page_cache_async_readahead(struct address_space *mapping,
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ondemand_readahead(mapping, ra, filp, true, offset, req_size);
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}
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EXPORT_SYMBOL_GPL(page_cache_async_readahead);
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static ssize_t
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do_readahead(struct address_space *mapping, struct file *filp,
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pgoff_t index, unsigned long nr)
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{
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if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
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return -EINVAL;
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force_page_cache_readahead(mapping, filp, index, nr);
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return 0;
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}
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SYSCALL_DEFINE(readahead)(int fd, loff_t offset, size_t count)
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{
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ssize_t ret;
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struct file *file;
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ret = -EBADF;
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file = fget(fd);
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if (file) {
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if (file->f_mode & FMODE_READ) {
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struct address_space *mapping = file->f_mapping;
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pgoff_t start = offset >> PAGE_CACHE_SHIFT;
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pgoff_t end = (offset + count - 1) >> PAGE_CACHE_SHIFT;
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unsigned long len = end - start + 1;
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ret = do_readahead(mapping, file, start, len);
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}
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fput(file);
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}
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return ret;
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}
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#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
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asmlinkage long SyS_readahead(long fd, loff_t offset, long count)
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{
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return SYSC_readahead((int) fd, offset, (size_t) count);
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}
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SYSCALL_ALIAS(sys_readahead, SyS_readahead);
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#endif
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