Please add this fix after my 27/31, your
huge-tmpfs-recovery-tweak-shmem_getpage_gfp-to-fill-team.patch
for later merging into it. Great catch by Mika Penttila, a bug which
prevented some unusual cases from being recovered into huge pages as
intended: an initially sparse head would be set PageTeam only after
this check. But the check is guarding against a racing disband, which
cannot happen before the head is published as PageTeam, plus we have
an additional reference on the head which keeps it safe throughout:
so very easily fixed.
Reported-by: Mika Penttila <mika.penttila@xxxxxxxxxxxx>
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
---
mm/shmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2938,7 +2938,7 @@ repeat:
page = *pagep;
lock_page(page);
head = page - (index & (HPAGE_PMD_NR-1));
- if (!PageTeam(head)) {
+ if (!PageTeam(head) && page != head) {
error = -ENOENT;
goto decused;
}
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