mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-19 02:04:19 +08:00
e8edc6e03a
First thing mm.h does is including sched.h solely for can_do_mlock() inline function which has "current" dereference inside. By dealing with can_do_mlock() mm.h can be detached from sched.h which is good. See below, why. This patch a) removes unconditional inclusion of sched.h from mm.h b) makes can_do_mlock() normal function in mm/mlock.c c) exports can_do_mlock() to not break compilation d) adds sched.h inclusions back to files that were getting it indirectly. e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were getting them indirectly Net result is: a) mm.h users would get less code to open, read, preprocess, parse, ... if they don't need sched.h b) sched.h stops being dependency for significant number of files: on x86_64 allmodconfig touching sched.h results in recompile of 4083 files, after patch it's only 3744 (-8.3%). Cross-compile tested on all arm defconfigs, all mips defconfigs, all powerpc defconfigs, alpha alpha-up arm i386 i386-up i386-defconfig i386-allnoconfig ia64 ia64-up m68k mips parisc parisc-up powerpc powerpc-up s390 s390-up sparc sparc-up sparc64 sparc64-up um-x86_64 x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig as well as my two usual configs. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
104 lines
2.4 KiB
C
104 lines
2.4 KiB
C
/*
|
|
* linux/mm/msync.c
|
|
*
|
|
* Copyright (C) 1994-1999 Linus Torvalds
|
|
*/
|
|
|
|
/*
|
|
* The msync() system call.
|
|
*/
|
|
#include <linux/fs.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/mman.h>
|
|
#include <linux/file.h>
|
|
#include <linux/syscalls.h>
|
|
#include <linux/sched.h>
|
|
|
|
/*
|
|
* MS_SYNC syncs the entire file - including mappings.
|
|
*
|
|
* MS_ASYNC does not start I/O (it used to, up to 2.5.67).
|
|
* Nor does it marks the relevant pages dirty (it used to up to 2.6.17).
|
|
* Now it doesn't do anything, since dirty pages are properly tracked.
|
|
*
|
|
* The application may now run fsync() to
|
|
* write out the dirty pages and wait on the writeout and check the result.
|
|
* Or the application may run fadvise(FADV_DONTNEED) against the fd to start
|
|
* async writeout immediately.
|
|
* So by _not_ starting I/O in MS_ASYNC we provide complete flexibility to
|
|
* applications.
|
|
*/
|
|
asmlinkage long sys_msync(unsigned long start, size_t len, int flags)
|
|
{
|
|
unsigned long end;
|
|
struct mm_struct *mm = current->mm;
|
|
struct vm_area_struct *vma;
|
|
int unmapped_error = 0;
|
|
int error = -EINVAL;
|
|
|
|
if (flags & ~(MS_ASYNC | MS_INVALIDATE | MS_SYNC))
|
|
goto out;
|
|
if (start & ~PAGE_MASK)
|
|
goto out;
|
|
if ((flags & MS_ASYNC) && (flags & MS_SYNC))
|
|
goto out;
|
|
error = -ENOMEM;
|
|
len = (len + ~PAGE_MASK) & PAGE_MASK;
|
|
end = start + len;
|
|
if (end < start)
|
|
goto out;
|
|
error = 0;
|
|
if (end == start)
|
|
goto out;
|
|
/*
|
|
* If the interval [start,end) covers some unmapped address ranges,
|
|
* just ignore them, but return -ENOMEM at the end.
|
|
*/
|
|
down_read(&mm->mmap_sem);
|
|
vma = find_vma(mm, start);
|
|
for (;;) {
|
|
struct file *file;
|
|
|
|
/* Still start < end. */
|
|
error = -ENOMEM;
|
|
if (!vma)
|
|
goto out_unlock;
|
|
/* Here start < vma->vm_end. */
|
|
if (start < vma->vm_start) {
|
|
start = vma->vm_start;
|
|
if (start >= end)
|
|
goto out_unlock;
|
|
unmapped_error = -ENOMEM;
|
|
}
|
|
/* Here vma->vm_start <= start < vma->vm_end. */
|
|
if ((flags & MS_INVALIDATE) &&
|
|
(vma->vm_flags & VM_LOCKED)) {
|
|
error = -EBUSY;
|
|
goto out_unlock;
|
|
}
|
|
file = vma->vm_file;
|
|
start = vma->vm_end;
|
|
if ((flags & MS_SYNC) && file &&
|
|
(vma->vm_flags & VM_SHARED)) {
|
|
get_file(file);
|
|
up_read(&mm->mmap_sem);
|
|
error = do_fsync(file, 0);
|
|
fput(file);
|
|
if (error || start >= end)
|
|
goto out;
|
|
down_read(&mm->mmap_sem);
|
|
vma = find_vma(mm, start);
|
|
} else {
|
|
if (start >= end) {
|
|
error = 0;
|
|
goto out_unlock;
|
|
}
|
|
vma = vma->vm_next;
|
|
}
|
|
}
|
|
out_unlock:
|
|
up_read(&mm->mmap_sem);
|
|
out:
|
|
return error ? : unmapped_error;
|
|
}
|