mm: move VM_LOCKED check to __mlock_vma_pages_range()

Use a single code path for faulting in pages during mlock.

The reason to have it in this patch series is that I did not want to
update both code paths in a later change that releases mmap_sem when
blocking on disk.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Michel Lespinasse 2011-01-13 15:46:12 -08:00 committed by Linus Torvalds
parent 110d74a921
commit 5fdb200213

View file

@ -169,7 +169,7 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
VM_BUG_ON(end > vma->vm_end);
VM_BUG_ON(!rwsem_is_locked(&mm->mmap_sem));
gup_flags = FOLL_TOUCH | FOLL_MLOCK;
gup_flags = FOLL_TOUCH;
/*
* We want to touch writable mappings with a write fault in order
* to break COW, except for shared mappings because these don't COW
@ -178,6 +178,9 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
if ((vma->vm_flags & (VM_WRITE | VM_SHARED)) == VM_WRITE)
gup_flags |= FOLL_WRITE;
if (vma->vm_flags & VM_LOCKED)
gup_flags |= FOLL_MLOCK;
/* We don't try to access the guard page of a stack vma */
if (stack_guard_page(vma, start)) {
addr += PAGE_SIZE;
@ -456,18 +459,15 @@ static int do_mlock_pages(unsigned long start, size_t len, int ignore_errors)
/*
* Now fault in a range of pages within the first VMA.
*/
if (vma->vm_flags & VM_LOCKED) {
ret = __mlock_vma_pages_range(vma, nstart, nend);
if (ret < 0 && ignore_errors) {
ret = 0;
continue; /* continue at next VMA */
}
if (ret) {
ret = __mlock_posix_error_return(ret);
break;
}
} else
make_pages_present(nstart, nend);
ret = __mlock_vma_pages_range(vma, nstart, nend);
if (ret < 0 && ignore_errors) {
ret = 0;
continue; /* continue at next VMA */
}
if (ret) {
ret = __mlock_posix_error_return(ret);
break;
}
}
up_read(&mm->mmap_sem);
return ret; /* 0 or negative error code */