diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-20 16:24:55 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-08-26 16:41:44 -0700 |
| commit | 378776c287c66b32ff9a62c34a9715f702dc336e (patch) | |
| tree | c259512f7f1a92343e1122cc10b81d97adc32431 /kernel/fork.c | |
| parent | d1a2ec482cff1d98c366a40b717dfd95a1a0fac5 (diff) | |
mm: make the vma list be doubly linked
commit 297c5eee372478fc32fec5fe8eed711eedb13f3d upstream.
It's a really simple list, and several of the users want to go backwards
in it to find the previous vma. So rather than have to look up the
previous entry with 'find_vma_prev()' or something similar, just make it
doubly linked instead.
Tested-by: Ian Campbell <ijc@hellion.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'kernel/fork.c')
| -rw-r--r-- | kernel/fork.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index ce2f5859933..9f3b066bf73 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -277,7 +277,7 @@ out: #ifdef CONFIG_MMU static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) { - struct vm_area_struct *mpnt, *tmp, **pprev; + struct vm_area_struct *mpnt, *tmp, *prev, **pprev; struct rb_node **rb_link, *rb_parent; int retval; unsigned long charge; @@ -305,6 +305,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) if (retval) goto out; + prev = NULL; for (mpnt = oldmm->mmap; mpnt; mpnt = mpnt->vm_next) { struct file *file; @@ -333,7 +334,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) vma_set_policy(tmp, pol); tmp->vm_flags &= ~VM_LOCKED; tmp->vm_mm = mm; - tmp->vm_next = NULL; + tmp->vm_next = tmp->vm_prev = NULL; anon_vma_link(tmp); file = tmp->vm_file; if (file) { @@ -367,6 +368,8 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm) */ *pprev = tmp; pprev = &tmp->vm_next; + tmp->vm_prev = prev; + prev = tmp; __vma_link_rb(mm, tmp, rb_link, rb_parent); rb_link = &tmp->vm_rb.rb_right; |