[PATCH 18/24] huge tmpfs: mmap_sem is unlocked when truncation splits huge pmd

zap_pmd_range()'s CONFIG_DEBUG_VM !rwsem_is_locked(_sem) BUG() is invalid with huge tmpfs, where truncation of a hugely-mapped file to an unhugely-aligned size easily hits it. (Although anon THP could in principle apply khugepaged to private file mappings, which are not excluded by the

[PATCH 18/24] huge tmpfs: mmap_sem is unlocked when truncation splits huge pmd

zap_pmd_range()'s CONFIG_DEBUG_VM !rwsem_is_locked(mmap_sem) BUG() is invalid with huge tmpfs, where truncation of a hugely-mapped file to an unhugely-aligned size easily hits it. (Although anon THP could in principle apply khugepaged to private file mappings, which are not excluded by the