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charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Nikita Kalyazin =0A= =0A= Move the check for pinning closer to where the result is used.=0A= No functional changes.=0A= =0A= Acked-by: David Hildenbrand (Arm) =0A= Signed-off-by: Nikita Kalyazin =0A= ---=0A= mm/gup.c | 23 ++++++++++++-----------=0A= 1 file changed, 12 insertions(+), 11 deletions(-)=0A= =0A= diff --git a/mm/gup.c b/mm/gup.c=0A= index e8367564d636..41eb64783e03 100644=0A= --- a/mm/gup.c=0A= +++ b/mm/gup.c=0A= @@ -2737,18 +2737,9 @@ EXPORT_SYMBOL(get_user_pages_unlocked);=0A= */=0A= static bool gup_fast_folio_allowed(struct folio *folio, unsigned int flags= )=0A= {=0A= - bool reject_file_backed =3D false;=0A= struct address_space *mapping;=0A= unsigned long mapping_flags;=0A= =0A= - /*=0A= - * If we aren't pinning then no problematic write can occur. A long term= =0A= - * pin is the most egregious case so this is the one we disallow.=0A= - */=0A= - if ((flags & (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE)) =3D=3D=0A= - (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE))=0A= - reject_file_backed =3D true;=0A= -=0A= /* We hold a folio reference, so we can safely access folio fields. */=0A= if (WARN_ON_ONCE(folio_test_slab(folio)))=0A= return false;=0A= @@ -2797,8 +2788,18 @@ static bool gup_fast_folio_allowed(struct folio *fol= io, unsigned int flags)=0A= */=0A= if (secretmem_mapping(mapping))=0A= return false;=0A= - /* The only remaining allowed file system is shmem. */=0A= - return !reject_file_backed || shmem_mapping(mapping);=0A= +=0A= + /*=0A= + * If we aren't pinning then no problematic write can occur. A writable= =0A= + * long term pin is the most egregious case, so this is the one we=0A= + * allow only for ...=0A= + */=0A= + if ((flags & (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE)) !=3D=0A= + (FOLL_PIN | FOLL_LONGTERM | FOLL_WRITE))=0A= + return true;=0A= +=0A= + /* ... hugetlb (which we allowed above already) and shared memory. */=0A= + return shmem_mapping(mapping);=0A= }=0A= =0A= #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL=0A= -- =0A= 2.50.1=0A= =0A=