On expansion failure, we try to restore vmg state, but we missed to
restore vmi.index. The reason is we have reset vmg->vma before checking.
So let's put the operation before reset vmg->vma.
Also we don't need to do the restore if there is no mergeable adjacent
VMA. Let's take it out to skip the unnecessary operations.
Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx>
CC: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
---
mm/vma.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/vma.c b/mm/vma.c
index fb4f1863f88e..c94d953d453c 100644
--- a/mm/vma.c
+++ b/mm/vma.c
@@ -954,23 +954,27 @@ struct vm_area_struct *vma_merge_new_range(struct vma_merge_struct *vmg)
vma_prev(vmg->vmi); /* Equivalent to going to the previous range */
}
+ /* No mergeable adjacent VMA, return */
+ if (!vmg->vma)
+ return NULL;
+
/*
* Now try to expand adjacent VMA(s). This takes care of removing the
* following VMA if we have VMAs on both sides.
*/
- if (vmg->vma && !vma_expand(vmg)) {
+ if (!vma_expand(vmg)) {
khugepaged_enter_vma(vmg->vma, vmg->flags);
vmg->state = VMA_MERGE_SUCCESS;
return vmg->vma;
}
/* If expansion failed, reset state. Allows us to retry merge later. */
+ if (vmg->vma == prev)
+ vma_iter_set(vmg->vmi, start);
vmg->vma = NULL;
vmg->start = start;
vmg->end = end;
vmg->pgoff = pgoff;
- if (vmg->vma == prev)
- vma_iter_set(vmg->vmi, start);
return NULL;
}
--
2.34.1
