Since we've now renamed vma_flags_test() to vma_flags_test_any() to be very clear as to what we are in fact testing, we now have the opportunity to bring vma_flags_test() back, but for explicitly testing a single VMA flag.
This is useful, as often flag tests are against a single flag, and vma_flags_test_any(flags, VMA_READ_BIT) reads oddly and potentially causes confusion. We use sparse to enforce that users won't accidentally pass vm_flags_t to this function without it being flagged so this should make it harder to get this wrong. Of course, passing vma_flags_t to the function is impossible, as it is a struct. Also update the VMA tests to reflect this change. Signed-off-by: Lorenzo Stoakes (Oracle) <[email protected]> --- include/linux/mm.h | 17 +++++++++++++++-- mm/hugetlb.c | 2 +- mm/shmem.c | 4 ++-- tools/testing/vma/include/dup.h | 8 ++++++++ 4 files changed, 26 insertions(+), 5 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 66b90de30bf6..5622d04c9ba9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1051,6 +1051,19 @@ static __always_inline vma_flags_t __mk_vma_flags(size_t count, return flags; } +/* + * Test whether a specific VMA flag is set, e.g.: + * + * if (vma_flags_test(flags, VMA_READ_BIT)) { ... } + */ +static __always_inline bool vma_flags_test(const vma_flags_t *flags, + vma_flag_t bit) +{ + const unsigned long *bitmap = flags->__vma_flags; + + return test_bit((__force int)bit, bitmap); +} + /* * Helper macro which bitwise-or combines the specified input flags into a * vma_flags_t bitmap value. E.g.: @@ -1957,8 +1970,8 @@ static inline bool vma_desc_is_cow_mapping(struct vm_area_desc *desc) { const vma_flags_t *flags = &desc->vma_flags; - return vma_flags_test_any(flags, VMA_MAYWRITE_BIT) && - !vma_flags_test_any(flags, VMA_SHARED_BIT); + return vma_flags_test(flags, VMA_MAYWRITE_BIT) && + !vma_flags_test(flags, VMA_SHARED_BIT); } #ifndef CONFIG_MMU diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 8286c5db2c12..bd9f3b2d2cb0 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -6591,7 +6591,7 @@ long hugetlb_reserve_pages(struct inode *inode, * attempt will be made for VM_NORESERVE to allocate a page * without using reserves */ - if (vma_flags_test_any(&vma_flags, VMA_NORESERVE_BIT)) + if (vma_flags_test(&vma_flags, VMA_NORESERVE_BIT)) return 0; /* diff --git a/mm/shmem.c b/mm/shmem.c index 965a8908200b..5e7dcf5bc5d3 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -3086,7 +3086,7 @@ static struct inode *__shmem_get_inode(struct mnt_idmap *idmap, spin_lock_init(&info->lock); atomic_set(&info->stop_eviction, 0); info->seals = F_SEAL_SEAL; - info->flags = vma_flags_test_any(&flags, VMA_NORESERVE_BIT) + info->flags = vma_flags_test(&flags, VMA_NORESERVE_BIT) ? SHMEM_F_NORESERVE : 0; info->i_crtime = inode_get_mtime(inode); info->fsflags = (dir == NULL) ? 0 : @@ -5827,7 +5827,7 @@ static struct file *__shmem_file_setup(struct vfsmount *mnt, const char *name, unsigned int i_flags) { const unsigned long shmem_flags = - vma_flags_test_any(&flags, VMA_NORESERVE_BIT) ? SHMEM_F_NORESERVE : 0; + vma_flags_test(&flags, VMA_NORESERVE_BIT) ? SHMEM_F_NORESERVE : 0; struct inode *inode; struct file *res; diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h index ef6b9d963acc..630478f0d583 100644 --- a/tools/testing/vma/include/dup.h +++ b/tools/testing/vma/include/dup.h @@ -844,6 +844,14 @@ static inline vma_flags_t __mk_vma_flags(size_t count, const vma_flag_t *bits); #define mk_vma_flags(...) __mk_vma_flags(COUNT_ARGS(__VA_ARGS__), \ (const vma_flag_t []){__VA_ARGS__}) +static __always_inline bool vma_flags_test(const vma_flags_t *flags, + vma_flag_t bit) +{ + const unsigned long *bitmap = flags->__vma_flags; + + return test_bit((__force int)bit, bitmap); +} + static __always_inline bool vma_flags_test_any_mask(const vma_flags_t *flags, vma_flags_t to_test) { -- 2.53.0
