The patch titled
Subject: hugetlbfs-use-i_mmap_rwsem-to-fix-page-fault-truncate-race-v3
has been added to the -mm tree. Its filename is
hugetlbfs-use-i_mmap_rwsem-to-fix-page-fault-truncate-race-v3.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/hugetlbfs-use-i_mmap_rwsem-to-fix-page-fault-truncate-race-v3.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/hugetlbfs-use-i_mmap_rwsem-to-fix-page-fault-truncate-race-v3.patch
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------------------------------------------------------
From: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Subject: hugetlbfs-use-i_mmap_rwsem-to-fix-page-fault-truncate-race-v3
Incorporated suggestions from Kirill. Code change to hold i_mmap_rwsem
for duration of copy in copy_hugetlb_page_range. Took i_mmap_rwsem in
hugetlbfs_evict_inode to be consistent with other callers. Other changes
were to documentation/comments.
Link: http://lkml.kernel.org/r/20181222223013.22193-3-mike.kravetz@xxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Fixes: ebed4bfc8da8 ("hugetlb: fix absurd HugePages_Rsvd")
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: "Aneesh Kumar K . V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: "Kirill A . Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Prakash Sangappa <prakash.sangappa@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
--- a/fs/hugetlbfs/inode.c~hugetlbfs-use-i_mmap_rwsem-to-fix-page-fault-truncate-race-v3
+++ a/fs/hugetlbfs/inode.c
@@ -462,9 +462,20 @@ static void remove_inode_hugepages(struc
static void hugetlbfs_evict_inode(struct inode *inode)
{
+ struct address_space *mapping = inode->i_mapping;
struct resv_map *resv_map;
+ /*
+ * The vfs layer guarantees that there are no other users of this
+ * inode. Therefore, it would be safe to call remove_inode_hugepages
+ * without holding i_mmap_rwsem. We acquire and hold here to be
+ * consistent with other callers. Since there will be no contention
+ * on the semaphore, overhead is negligible.
+ */
+ i_mmap_lock_write(mapping);
remove_inode_hugepages(inode, 0, LLONG_MAX);
+ i_mmap_unlock_write(mapping);
+
resv_map = (struct resv_map *)inode->i_mapping->private_data;
/* root inode doesn't have the resv_map, so we should check it */
if (resv_map)
_
Patches currently in -mm which might be from mike.kravetz@xxxxxxxxxx are
hugetlbfs-use-i_mmap_rwsem-for-more-pmd-sharing-synchronization.patch
hugetlbfs-use-i_mmap_rwsem-for-more-pmd-sharing-synchronization-fix.patch
hugetlbfs-use-i_mmap_rwsem-to-fix-page-fault-truncate-race.patch
hugetlbfs-use-i_mmap_rwsem-to-fix-page-fault-truncate-race-v3.patch
