mm: reintroduce vma_desc_test() as a singular flag test

Similar to vma_flags_test(), we have previously renamed vma_desc_test() to
vma_desc_test_any().  Now that is in place, we can reintroduce
vma_desc_test() to explicitly check for a single VMA flag.

As with vma_flags_test(), this is useful as often flag tests are against a
single flag, and vma_desc_test_any(flags, VMA_READ_BIT) reads oddly and
potentially causes confusion.

As with vma_flags_test() a combination of sparse and vma_flags_t being a
struct means that users cannot misuse this function without it getting
flagged.

Also update the VMA tests to reflect this change.

Link: https://lkml.kernel.org/r/3a65ca23defb05060333f0586428fe279a484564.1772704455.git.ljs@kernel.org
Signed-off-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Babu Moger <babu.moger@amd.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Chatre, Reinette <reinette.chatre@intel.com>
Cc: Chunhai Guo <guochunhai@vivo.com>
Cc: Damien Le Maol <dlemoal@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: Gao Xiang <xiang@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hongbo Li <lihongbo22@huawei.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Morse <james.morse@arm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jeffle Xu <jefflexu@linux.alibaba.com>
Cc: Johannes Thumshirn <jth@kernel.org>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Naohiro Aota <naohiro.aota@wdc.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Sandeep Dhavale <dhavale@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yue Hu <zbestahu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

drivers/char/mem.c

@@ -520,7 +520,7 @@ static int mmap_zero_prepare(struct vm_area_desc *desc)
 #ifndef CONFIG_MMU
 	return -ENOSYS;
 #endif
-	if (vma_desc_test_any(desc, VMA_SHARED_BIT))
+	if (vma_desc_test(desc, VMA_SHARED_BIT))
 		return shmem_zero_setup_desc(desc);
 
 	desc->action.success_hook = mmap_zero_private_success;

fs/hugetlbfs/inode.c

@@ -164,7 +164,7 @@ static int hugetlbfs_file_mmap_prepare(struct vm_area_desc *desc)
 		goto out;
 
 	ret = 0;
-	if (vma_desc_test_any(desc, VMA_WRITE_BIT) && inode->i_size < len)
+	if (vma_desc_test(desc, VMA_WRITE_BIT) && inode->i_size < len)
 		i_size_write(inode, len);
 out:
 	inode_unlock(inode);

fs/ntfs3/file.c

@@ -276,7 +276,7 @@ static int ntfs_file_mmap_prepare(struct vm_area_desc *desc)
 	struct file *file = desc->file;
 	struct inode *inode = file_inode(file);
 	struct ntfs_inode *ni = ntfs_i(inode);
-	const bool rw = vma_desc_test_any(desc, VMA_WRITE_BIT);
+	const bool rw = vma_desc_test(desc, VMA_WRITE_BIT);
 	int err;
 
 	/* Avoid any operation if inode is bad. */

fs/resctrl/pseudo_lock.c

@@ -1044,7 +1044,7 @@ static int pseudo_lock_dev_mmap_prepare(struct vm_area_desc *desc)
 	 * Ensure changes are carried directly to the memory being mapped,
 	 * do not allow copy-on-write mapping.
 	 */
-	if (!vma_desc_test_any(desc, VMA_SHARED_BIT)) {
+	if (!vma_desc_test(desc, VMA_SHARED_BIT)) {
 		mutex_unlock(&rdtgroup_mutex);
 		return -EINVAL;
 	}

include/linux/dax.h

@@ -69,7 +69,7 @@ static inline bool daxdev_mapping_supported(const struct vm_area_desc *desc,
 					    const struct inode *inode,
 					    struct dax_device *dax_dev)
 {
-	if (!vma_desc_test_any(desc, VMA_SYNC_BIT))
+	if (!vma_desc_test(desc, VMA_SYNC_BIT))
 		return true;
 	if (!IS_DAX(inode))
 		return false;
@@ -115,7 +115,7 @@ static inline bool daxdev_mapping_supported(const struct vm_area_desc *desc,
 					    const struct inode *inode,
 					    struct dax_device *dax_dev)
 {
-	return !vma_desc_test_any(desc, VMA_SYNC_BIT);
+	return !vma_desc_test(desc, VMA_SYNC_BIT);
 }
 static inline size_t dax_recovery_write(struct dax_device *dax_dev,
 		pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i)

include/linux/mm.h

@@ -1192,6 +1192,17 @@ static inline void vma_set_flags_mask(struct vm_area_struct *vma,
 #define vma_set_flags(vma, ...) \
 	vma_set_flags_mask(vma, mk_vma_flags(__VA_ARGS__))
 
+/*
+ * Test whether a specific VMA flag is set in a VMA descriptor, e.g.:
+ *
+ * if (vma_desc_test(desc, VMA_READ_BIT)) { ... }
+ */
+static __always_inline bool vma_desc_test(const struct vm_area_desc *desc,
+		vma_flag_t bit)
+{
+	return vma_flags_test(&desc->vma_flags, bit);
+}
+
 /* Helper to test any VMA flags in a VMA descriptor. */
 static inline bool vma_desc_test_any_mask(const struct vm_area_desc *desc,
 		vma_flags_t flags)

mm/hugetlb.c

@@ -1194,7 +1194,7 @@ static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
 static void set_vma_desc_resv_map(struct vm_area_desc *desc, struct resv_map *map)
 {
 	VM_WARN_ON_ONCE(!is_vma_hugetlb_flags(&desc->vma_flags));
-	VM_WARN_ON_ONCE(vma_desc_test_any(desc, VMA_MAYSHARE_BIT));
+	VM_WARN_ON_ONCE(vma_desc_test(desc, VMA_MAYSHARE_BIT));
 
 	desc->private_data = map;
 }
@@ -1202,7 +1202,7 @@ static void set_vma_desc_resv_map(struct vm_area_desc *desc, struct resv_map *ma
 static void set_vma_desc_resv_flags(struct vm_area_desc *desc, unsigned long flags)
 {
 	VM_WARN_ON_ONCE(!is_vma_hugetlb_flags(&desc->vma_flags));
-	VM_WARN_ON_ONCE(vma_desc_test_any(desc, VMA_MAYSHARE_BIT));
+	VM_WARN_ON_ONCE(vma_desc_test(desc, VMA_MAYSHARE_BIT));
 
 	desc->private_data = (void *)((unsigned long)desc->private_data | flags);
 }
@@ -6602,7 +6602,7 @@ long hugetlb_reserve_pages(struct inode *inode,
 	 * to reserve the full area even if read-only as mprotect() may be
 	 * called to make the mapping read-write. Assume !desc is a shm mapping
 	 */
-	if (!desc || vma_desc_test_any(desc, VMA_MAYSHARE_BIT)) {
+	if (!desc || vma_desc_test(desc, VMA_MAYSHARE_BIT)) {
 		/*
 		 * resv_map can not be NULL as hugetlb_reserve_pages is only
 		 * called for inodes for which resv_maps were created (see
@@ -6636,7 +6636,7 @@ long hugetlb_reserve_pages(struct inode *inode,
 	if (err < 0)
 		goto out_err;
 
-	if (desc && !vma_desc_test_any(desc, VMA_MAYSHARE_BIT) && h_cg) {
+	if (desc && !vma_desc_test(desc, VMA_MAYSHARE_BIT) && h_cg) {
 		/* For private mappings, the hugetlb_cgroup uncharge info hangs
 		 * of the resv_map.
 		 */
@@ -6673,7 +6673,7 @@ long hugetlb_reserve_pages(struct inode *inode,
 	 * consumed reservations are stored in the map. Hence, nothing
 	 * else has to be done for private mappings here
 	 */
-	if (!desc || vma_desc_test_any(desc, VMA_MAYSHARE_BIT)) {
+	if (!desc || vma_desc_test(desc, VMA_MAYSHARE_BIT)) {
 		add = region_add(resv_map, from, to, regions_needed, h, h_cg);
 
 		if (unlikely(add < 0)) {
@@ -6737,7 +6737,7 @@ long hugetlb_reserve_pages(struct inode *inode,
 	hugetlb_cgroup_uncharge_cgroup_rsvd(hstate_index(h),
 					    chg * pages_per_huge_page(h), h_cg);
 out_err:
-	if (!desc || vma_desc_test_any(desc, VMA_MAYSHARE_BIT))
+	if (!desc || vma_desc_test(desc, VMA_MAYSHARE_BIT))
 		/* Only call region_abort if the region_chg succeeded but the
 		 * region_add failed or didn't run.
 		 */

tools/testing/vma/include/dup.h

@@ -922,6 +922,12 @@ static inline void vma_set_flags_mask(struct vm_area_struct *vma,
 #define vma_set_flags(vma, ...) \
 	vma_set_flags_mask(vma, mk_vma_flags(__VA_ARGS__))
 
+static __always_inline bool vma_desc_test(const struct vm_area_desc *desc,
+		vma_flag_t bit)
+{
+	return vma_flags_test(&desc->vma_flags, bit);
+}
+
 static inline bool vma_desc_test_any_mask(const struct vm_area_desc *desc,
 					    vma_flags_t flags)
 {