I stumbled on these two hugetlbfs issues while looking at other things:
- The 'restore reserve' functionality at page free time should not
be adjusting subpool counts.
- A BUG can be triggered (not easily) due to temporarily mapping a
page before doing a COW.
Both are described in detail in the commit message of the patches.
I would appreciate comments from Davidlohr Bueso as one patch is
directly related to code he added in commit 8382d914ebf7.
I did not cc stable as the first problem has been around since reserves
were added to hugetlbfs and nobody has noticed. The second is very hard
to hit/reproduce.
v2 - Update definition and all callers of hugetlb_fault_mutex_hash as
the arguments mm and vma are no longer used or necessary.
Mike Kravetz (2):
huegtlbfs: on restore reserve error path retain subpool reservation
hugetlb: use same fault hash key for shared and private mappings
fs/hugetlbfs/inode.c | 7 ++-----
include/linux/hugetlb.h | 4 +---
mm/hugetlb.c | 43 +++++++++++++++++++++--------------------
mm/userfaultfd.c | 3 +--
4 files changed, 26 insertions(+), 31 deletions(-)
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2.20.1
