From: Nikita Kalyazin <[email protected]> Move the check for pinning closer to where the result is used. No functional changes.
Signed-off-by: Nikita Kalyazin <[email protected]> --- mm/gup.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 5856d35be385..869d79c8daa4 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2737,18 +2737,9 @@ EXPORT_SYMBOL(get_user_pages_unlocked); */ static bool gup_fast_folio_allowed(struct folio *folio, unsigned int flags) { - bool reject_file_backed = false; struct address_space *mapping; unsigned long mapping_flags; - /* - * If we aren't pinning then no problematic write can occur. A long term - * pin is the most egregious case so this is the one we disallow. - */ - if ((flags & (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE)) == - (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE)) - reject_file_backed = true; - /* We hold a folio reference, so we can safely access folio fields. */ if (WARN_ON_ONCE(folio_test_slab(folio))) return false; @@ -2793,8 +2784,18 @@ static bool gup_fast_folio_allowed(struct folio *folio, unsigned int flags) */ if (secretmem_mapping(mapping)) return false; - /* The only remaining allowed file system is shmem. */ - return !reject_file_backed || shmem_mapping(mapping); + + /* + * If we aren't pinning then no problematic write can occur. A writable + * long term pin is the most egregious case, so this is the one we + * allow only for ... + */ + if ((flags & (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE)) != + (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE)) + return true; + + /* ... hugetlb (which we allowed above already) and shared memory. */ + return shmem_mapping(mapping); } #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL -- 2.50.1
