mm/mmap/vma_merge: use the proper vma pointer in case 4

Almost all cases now use the 'next' pointer for the vma following the
merged area, and the cases diagram shows it as XXXX.  Case 4 is different
as it uses 'mid' and NNNN, so change it for consistency.  No functional
change.

Link: https://lkml.kernel.org/r/20230309111258.24079-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Vlastimil Babka 2023-03-09 12:12:52 +01:00 committed by Andrew Morton
parent 5ff783f151
commit 183b7a60d3

View file

@ -851,9 +851,9 @@ can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
* vma, PPPPPP is the prev vma specified, and NNNNNN the next vma after:
*
* AAAA AAAA AAAA
* PPPPPPNNNNNN PPPPPPNNNNNN PPPPPPNNNNNN
* PPPPPPNNNNNN PPPPPPXXXXXX PPPPPPNNNNNN
* cannot merge might become might become
* PPNNNNNNNNNN PPPPPPPPPPNN
* PPXXXXXXXXXX PPPPPPPPPPNN
* mmap, brk or case 4 below case 5 below
* mremap move:
* AAAA AAAA
@ -972,9 +972,9 @@ struct vm_area_struct *vma_merge(struct vma_iterator *vmi, struct mm_struct *mm,
res = next;
if (prev && addr < prev->vm_end) { /* case 4 */
vma_end = addr;
adjust = mid;
adjust = next;
adj_next = -(prev->vm_end - addr);
err = dup_anon_vma(mid, prev);
err = dup_anon_vma(next, prev);
} else {
vma = next; /* case 3 */
vma_start = addr;