path: root/include
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authorHugh Dickins <hughd@google.com>2014-03-20 21:52:17 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-03-20 22:09:09 -0700
commit7e09e738afd21ef99f047425fc0b0c9be8b03254 (patch)
tree423cb848a7d6875509b99720d4afcfa208bac078 /include
parent3fb725c48b93c0a152174b6dbbc1029b5e734c7b (diff)
mm: fix swapops.h:131 bug if remap_file_pages raced migration
Add remove_linear_migration_ptes_from_nonlinear(), to fix an interesting little include/linux/swapops.h:131 BUG_ON(!PageLocked) found by trinity: indicating that remove_migration_ptes() failed to find one of the migration entries that was temporarily inserted. The problem comes from remap_file_pages()'s switch from vma_interval_tree (good for inserting the migration entry) to i_mmap_nonlinear list (no good for locating it again); but can only be a problem if the remap_file_pages() range does not cover the whole of the vma (zap_pte() clears the range). remove_migration_ptes() needs a file_nonlinear method to go down the i_mmap_nonlinear list, applying linear location to look for migration entries in those vmas too, just in case there was this race. The file_nonlinear method does need rmap_walk_control.arg to do this; but it never needed vma passed in - vma comes from its own iteration. Reported-and-tested-by: Dave Jones <davej@redhat.com> Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
1 files changed, 1 insertions, 2 deletions
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 1da693d51255..b66c2110cb1f 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -250,8 +250,7 @@ struct rmap_walk_control {
int (*rmap_one)(struct page *page, struct vm_area_struct *vma,
unsigned long addr, void *arg);
int (*done)(struct page *page);
- int (*file_nonlinear)(struct page *, struct address_space *,
- struct vm_area_struct *vma);
+ int (*file_nonlinear)(struct page *, struct address_space *, void *arg);
struct anon_vma *(*anon_lock)(struct page *page);
bool (*invalid_vma)(struct vm_area_struct *vma, void *arg);