From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm/hugeltb: simplify the return code of __vma_reservation_common() It's guaranteed that the vma is associated with a resv_map, i.e. either VM_MAYSHARE or HPAGE_RESV_OWNER, when the code reaches here or we would have returned via !resv check above. So it's unneeded to check whether HPAGE_RESV_OWNER is set here. Simplify the return code to make it more clear. Link: https://lkml.kernel.org/r/20210410072348.20437-3-linmiaohe@xxxxxxxxxx Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Cc: Feilong Lin <linfeilong@xxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 41 ++++++++++++++++++++--------------------- 1 file changed, 20 insertions(+), 21 deletions(-) --- a/mm/hugetlb.c~mm-hugeltb-simplify-the-return-code-of-__vma_reservation_common +++ a/mm/hugetlb.c @@ -2174,27 +2174,26 @@ static long __vma_reservation_common(str if (vma->vm_flags & VM_MAYSHARE) return ret; - else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER) && ret >= 0) { - /* - * In most cases, reserves always exist for private mappings. - * However, a file associated with mapping could have been - * hole punched or truncated after reserves were consumed. - * As subsequent fault on such a range will not use reserves. - * Subtle - The reserve map for private mappings has the - * opposite meaning than that of shared mappings. If NO - * entry is in the reserve map, it means a reservation exists. - * If an entry exists in the reserve map, it means the - * reservation has already been consumed. As a result, the - * return value of this routine is the opposite of the - * value returned from reserve map manipulation routines above. - */ - if (ret) - return 0; - else - return 1; - } - else - return ret < 0 ? ret : 0; + /* + * We know private mapping must have HPAGE_RESV_OWNER set. + * + * In most cases, reserves always exist for private mappings. + * However, a file associated with mapping could have been + * hole punched or truncated after reserves were consumed. + * As subsequent fault on such a range will not use reserves. + * Subtle - The reserve map for private mappings has the + * opposite meaning than that of shared mappings. If NO + * entry is in the reserve map, it means a reservation exists. + * If an entry exists in the reserve map, it means the + * reservation has already been consumed. As a result, the + * return value of this routine is the opposite of the + * value returned from reserve map manipulation routines above. + */ + if (ret > 0) + return 0; + if (ret == 0) + return 1; + return ret; } static long vma_needs_reservation(struct hstate *h, _
