From: Pavel Tatashin pasha.tatashin@soleen.com
[ Upstream commit f0f4463837da17a89d965dcbe4e411629dbcf308 ]
When migration failure occurs, we still pin pages, which means that we may pin CMA movable pages which should never be the case.
Instead return an error without pinning pages when migration failure happens.
No need to retry migrating, because migrate_pages() already retries 10 times.
Link: https://lkml.kernel.org/r/20210215161349.246722-4-pasha.tatashin@soleen.com Signed-off-by: Pavel Tatashin pasha.tatashin@soleen.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Cc: Dan Williams dan.j.williams@intel.com Cc: David Hildenbrand david@redhat.com Cc: David Rientjes rientjes@google.com Cc: Ingo Molnar mingo@redhat.com Cc: Ira Weiny ira.weiny@intel.com Cc: James Morris jmorris@namei.org Cc: Jason Gunthorpe jgg@ziepe.ca Cc: John Hubbard jhubbard@nvidia.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: Matthew Wilcox willy@infradead.org Cc: Mel Gorman mgorman@suse.de Cc: Michal Hocko mhocko@kernel.org Cc: Michal Hocko mhocko@suse.com Cc: Mike Kravetz mike.kravetz@oracle.com Cc: Oscar Salvador osalvador@suse.de Cc: Peter Zijlstra peterz@infradead.org Cc: Sasha Levin sashal@kernel.org Cc: Steven Rostedt (VMware) rostedt@goodmis.org Cc: Tyler Hicks tyhicks@linux.microsoft.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 Signed-off-by: Sasha Levin sashal@kernel.org --- mm/gup.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-)
diff --git a/mm/gup.c b/mm/gup.c index 6530672131db..2b48c65e27cc 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1553,7 +1553,6 @@ static long check_and_migrate_cma_pages(struct mm_struct *mm, { unsigned long i; bool drain_allow = true; - bool migrate_allow = true; LIST_HEAD(cma_page_list); long ret = nr_pages; struct page *prev_head, *head; @@ -1604,17 +1603,15 @@ check_again: for (i = 0; i < nr_pages; i++) put_page(pages[i]);
- if (migrate_pages(&cma_page_list, alloc_migration_target, NULL, - (unsigned long)&mtc, MIGRATE_SYNC, MR_CONTIG_RANGE)) { - /* - * some of the pages failed migration. Do get_user_pages - * without migration. - */ - migrate_allow = false; - + ret = migrate_pages(&cma_page_list, alloc_migration_target, + NULL, (unsigned long)&mtc, MIGRATE_SYNC, + MR_CONTIG_RANGE); + if (ret) { if (!list_empty(&cma_page_list)) putback_movable_pages(&cma_page_list); + return ret > 0 ? -ENOMEM : ret; } + /* * We did migrate all the pages, Try to get the page references * again migrating any new CMA pages which we failed to isolate @@ -1624,7 +1621,7 @@ check_again: pages, vmas, NULL, gup_flags);
- if ((ret > 0) && migrate_allow) { + if (ret > 0) { nr_pages = ret; drain_allow = true; goto check_again;