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authorMiaohe Lin <linmiaohe@huawei.com>2021-11-05 23:42:16 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-11-06 23:30:40 +0300
commite1d8c966dbf11afcac1d115f3fca5a29060bba18 (patch)
tree480d4c4b48b1854b7b08cb0411d30b34daf01098
parentad0ce23ed099492d7ed1f87cd8cf39a68b9f20a0 (diff)
downloadlinux-e1d8c966dbf11afcac1d115f3fca5a29060bba18.tar.xz
mm/page_isolation: fix potential missing call to unset_migratetype_isolate()
In start_isolate_page_range() undo path, pfn_to_online_page() just checks the first pfn in a pageblock while __first_valid_page() will traverse the pageblock until the first online pfn is found. So we may miss the call to unset_migratetype_isolate() in undo path and pages will remain isolated unexpectedly. Fix this by calling undo_isolate_page_range() and this will also help to simplify the code further. Note we shouldn't ever trigger it because MAX_ORDER-1 aligned pfn ranges shouldn't contain memory holes now. Link: https://lkml.kernel.org/r/20210914114348.15569-1-linmiaohe@huawei.com Fixes: 2ce13640b3f4 ("mm: __first_valid_page skip over offline pages") Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/page_isolation.c20
1 files changed, 3 insertions, 17 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index a95c2c6562d0..f93cc63d8fa1 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -183,7 +183,6 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
unsigned migratetype, int flags)
{
unsigned long pfn;
- unsigned long undo_pfn;
struct page *page;
BUG_ON(!IS_ALIGNED(start_pfn, pageblock_nr_pages));
@@ -193,25 +192,12 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
pfn < end_pfn;
pfn += pageblock_nr_pages) {
page = __first_valid_page(pfn, pageblock_nr_pages);
- if (page) {
- if (set_migratetype_isolate(page, migratetype, flags)) {
- undo_pfn = pfn;
- goto undo;
- }
+ if (page && set_migratetype_isolate(page, migratetype, flags)) {
+ undo_isolate_page_range(start_pfn, pfn, migratetype);
+ return -EBUSY;
}
}
return 0;
-undo:
- for (pfn = start_pfn;
- pfn < undo_pfn;
- pfn += pageblock_nr_pages) {
- struct page *page = pfn_to_online_page(pfn);
- if (!page)
- continue;
- unset_migratetype_isolate(page, migratetype);
- }
-
- return -EBUSY;
}
/*