The patch titled
mlock-mlocked-pages-are-unevictable: fix truncate race and sevaral comments
has been added to the -mm tree. Its filename is
mlock-mlocked-pages-are-unevictable-fix-truncate-race-and-sevaral-comments.patch
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------------------------------------------------------
Subject: mlock-mlocked-pages-are-unevictable: fix truncate race and sevaral comments
From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
This patch is part of putback_lru_page() rework. several comment fix and
one bugfix contained.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mlock.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)
diff -puN mm/mlock.c~mlock-mlocked-pages-are-unevictable-fix-truncate-race-and-sevaral-comments mm/mlock.c
--- a/mm/mlock.c~mlock-mlocked-pages-are-unevictable-fix-truncate-race-and-sevaral-comments
+++ a/mm/mlock.c
@@ -54,7 +54,11 @@ EXPORT_SYMBOL(can_do_mlock);
*/
void __clear_page_mlock(struct page *page)
{
- VM_BUG_ON(!PageLocked(page)); /* for LRU isolate/putback */
+ VM_BUG_ON(!PageLocked(page));
+
+ if (!page->mapping) { /* truncated ? */
+ return;
+ }
if (!isolate_lru_page(page)) {
putback_lru_page(page);
@@ -138,7 +142,9 @@ static int __mlock_vma_pages_range(struc
/*
* get_user_pages makes pages present if we are
- * setting mlock.
+ * setting mlock. and this extra reference count will
+ * disable migration of this page. However, page may
+ * still be truncated out from under us.
*/
ret = get_user_pages(current, mm, addr,
min_t(int, nr_pages, ARRAY_SIZE(pages)),
@@ -166,11 +172,12 @@ static int __mlock_vma_pages_range(struc
for (i = 0; i < ret; i++) {
struct page *page = pages[i];
+ lock_page(page);
/*
- * page might be truncated or migrated out from under
- * us. Check after acquiring page lock.
+ * Because we lock page here and migration is blocked
+ * by the elevated reference, we need only check for
+ * page truncation (file-cache only).
*/
- lock_page(page);
if (page->mapping)
mlock_vma_page(page);
unlock_page(page);
_
Patches currently in -mm which might be from kosaki.motohiro@xxxxxxxxxxxxxx are
page-allocator-inlnie-some-__alloc_pages-wrappers.patch
page-allocator-inlnie-some-__alloc_pages-wrappers-fix.patch
mm-hugetlbc-fix-duplicate-variable.patch
page-flags-record-page-flag-overlays-explicitly.patch
slub-record-page-flag-overlays-explicitly.patch
slob-record-page-flag-overlays-explicitly.patch
pm-schedule-sysrq-poweroff-on-boot-cpu-fix.patch
call_usermodehelper-increase-reliability.patch
cgroup-list_for_each-cleanup-v2.patch
cgroup-anotate-two-variables-with-__read_mostly.patch
memcg-remove-refcnt-from-page_cgroup-fix-memcg-fix-mem_cgroup_end_migration-race.patch
memcg-remove-refcnt-from-page_cgroup-memcg-fix-shmem_unuse_inode-charging.patch
memcg-handle-swap-cache-fix-shmem-page-migration-incorrectness-on-memcgroup.patch
memcg-clean-up-checking-of-the-disabled-flag.patch
memcg-clean-up-checking-of-the-disabled-flag-memcg-further-checking-of-disabled-flag.patch
per-task-delay-accounting-update-document-and-getdelaysc-for-memory-reclaim.patch
full-conversion-to-early_initcall-interface-remove-old-interface-fix-fix.patch
relay-add-buffer-only-channels-useful-for-early-logging-fix.patch
mm-speculative-page-references-fix-migration_entry_wait-for-speculative-page-cache.patch
vmscan-use-an-indexed-array-for-lru-variables.patch
swap-use-an-array-for-the-lru-pagevecs.patch
define-page_file_cache-function-fix-splitlru-shmem_getpage-setpageswapbacked-sooner.patch
vmscan-split-lru-lists-into-anon-file-sets-collect-lru-meminfo-statistics-from-correct-offset.patch
vmscan-split-lru-lists-into-anon-file-sets-prevent-incorrect-oom-under-split_lru.patch
vmscan-split-lru-lists-into-anon-file-sets-split_lru-fix-pagevec_move_tail-doesnt-treat-unevictable-page.patch
vmscan-split-lru-lists-into-anon-file-sets-splitlru-memcg-swapbacked-pages-active.patch
vmscan-split-lru-lists-into-anon-file-sets-splitlru-bdi_cap_swap_backed.patch
vmscan-second-chance-replacement-for-anonymous-pages.patch
unevictable-lru-infrastructure.patch
unevictable-lru-infrastructure-fix.patch
unevictable-lru-infrastructure-remove-redundant-page-mapping-check.patch
unevictable-lru-infrastructure-putback_lru_page-unevictable-page-handling-rework.patch
unevictable-lru-infrastructure-kill-unnecessary-lock_page-in-vmscanc.patch
unevictable-lru-infrastructure-revert-migration-change-of-unevictable-lru-infrastructure.patch
unevictable-lru-page-statistics.patch
unevictable-lru-page-statistics-fix-printk-in-show_free_areas.patch
unevictable-lru-page-statistics-units-fix.patch
shm_locked-pages-are-unevictable.patch
shm_locked-pages-are-unevictable-revert-shm-change-of-shm_locked-pages-are-unevictable-patch.patch
mlock-mlocked-pages-are-unevictable.patch
mlock-mlocked-pages-are-unevictable-fix.patch
mlock-mlocked-pages-are-unevictable-fix-fix.patch
mlock-mlocked-pages-are-unevictable-fix-3.patch
mlock-mlocked-pages-are-unevictable-fix-fix-munlock-page-table-walk-now-requires-mm.patch
mlock-mlocked-pages-are-unevictable-restore-patch-failure-hunk-of-mlock-mlocked-pages-are-unevictablepatch.patch
mlock-mlocked-pages-are-unevictable-fix-truncate-race-and-sevaral-comments.patch
mmap-handle-mlocked-pages-during-map-remap-unmap.patch
fix-double-unlock_page-in-2626-rc5-mm3-kernel-bug-at-mm-filemapc-575.patch
mmap-handle-mlocked-pages-during-map-remap-unmap-cleanup.patch
vmstat-mlocked-pages-statistics.patch
vmstat-mlocked-pages-statistics-fix-incorrect-mlocked-field-of-proc-meminfo.patch
vmstat-mlocked-pages-statistics-fix.patch
swap-cull-unevictable-pages-in-fault-path-fix.patch
vmstat-unevictable-and-mlocked-pages-vm-events.patch
restore-patch-failure-of-vmstat-unevictable-and-mlocked-pages-vm-eventspatch.patch
vmscan-unevictable-lru-scan-sysctl.patch
vmscan-unevictable-lru-scan-sysctl-nommu-fix.patch
vmscam-kill-unused-lru-functions.patch
make-mm-memoryc-print_bad_pte-static.patch
mm-swapfilec-make-code-static.patch
make-mm-rmapc-anon_vma_cachep-static.patch
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