Using the PAGE_ALIGN() macro instead of "manual" alignment and
improved readability of the loop traversing the process memory regions.
Signed-off-by: Anton Salikhmetov <[EMAIL PROTECTED]>
---
mm/msync.c | 77 ++++++++++++++++++++++++++++--------------------------------
1 files changed, 36 insertions(+), 41 deletions(-)
diff --git a/mm/msync.c b/mm/msync.c
index 144a757..a4de868 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -1,85 +1,83 @@
/*
- * linux/mm/msync.c
+ * The msync() system call.
*
- * Copyright (C) 1994-1999 Linus Torvalds
+ * Copyright (C) 1994-1999 Linus Torvalds
+ * Copyright (C) 2008 Anton Salikhmetov <[EMAIL PROTECTED]>
*/
-/*
- * The msync() system call.
- */
+#include <linux/file.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/mman.h>
-#include <linux/file.h>
-#include <linux/syscalls.h>
#include <linux/sched.h>
+#include <linux/syscalls.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).
+ * Nor does it mark 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.
+ * 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;
+ int error, unmapped_error;
struct vm_area_struct *vma;
- int unmapped_error = 0;
- int error = -EINVAL;
+ struct mm_struct *mm;
+ 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;
+ len = PAGE_ALIGN(len);
end = start + len;
if (end < start)
goto out;
- error = 0;
+
+ error = unmapped_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.
*/
+ mm = current->mm;
down_read(&mm->mmap_sem);
vma = find_vma(mm, start);
- for (;;) {
+ do {
struct file *file;
- /* Still start < end. */
error = -ENOMEM;
if (!vma)
- goto out_unlock;
- /* Here start < vma->vm_end. */
+ break;
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;
+ break;
+ unmapped_error = error;
}
- file = vma->vm_file;
+
+ error = -EBUSY;
+ if ((flags & MS_INVALIDATE) && (vma->vm_flags & VM_LOCKED))
+ break;
+
+ error = 0;
start = vma->vm_end;
- if ((flags & MS_SYNC) && file &&
- (vma->vm_flags & VM_SHARED)) {
+ file = vma->vm_file;
+ if (file && (vma->vm_flags & VM_SHARED) && (flags & MS_SYNC)) {
get_file(file);
up_read(&mm->mmap_sem);
error = do_fsync(file, 0);
@@ -88,16 +86,13 @@ asmlinkage long sys_msync(unsigned long start, size_t len,
int flags)
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;
+ continue;
}
- }
-out_unlock:
+
+ vma = vma->vm_next;
+ } while (start < end);
up_read(&mm->mmap_sem);
+
out:
- return error ? : unmapped_error;
+ return error ? error : unmapped_error;
}
--
1.4.4.4
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