1 files changed, 41 insertions, 7 deletions

diff --git a/fs/stat.c b/fs/stat.c
index 6f65b3456cad..89ce1be56310 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -90,6 +90,37 @@ void generic_fill_statx_attr(struct inode *inode, struct kstat *stat)
 EXPORT_SYMBOL(generic_fill_statx_attr);
 
 /**
+ * generic_fill_statx_atomic_writes - Fill in atomic writes statx attributes
+ * @stat:	Where to fill in the attribute flags
+ * @unit_min:	Minimum supported atomic write length in bytes
+ * @unit_max:	Maximum supported atomic write length in bytes
+ *
+ * Fill in the STATX{_ATTR}_WRITE_ATOMIC flags in the kstat structure from
+ * atomic write unit_min and unit_max values.
+ */
+void generic_fill_statx_atomic_writes(struct kstat *stat,
+				      unsigned int unit_min,
+				      unsigned int unit_max)
+{
+	/* Confirm that the request type is known */
+	stat->result_mask |= STATX_WRITE_ATOMIC;
+
+	/* Confirm that the file attribute type is known */
+	stat->attributes_mask |= STATX_ATTR_WRITE_ATOMIC;
+
+	if (unit_min) {
+		stat->atomic_write_unit_min = unit_min;
+		stat->atomic_write_unit_max = unit_max;
+		/* Initially only allow 1x segment */
+		stat->atomic_write_segments_max = 1;
+
+		/* Confirm atomic writes are actually supported */
+		stat->attributes |= STATX_ATTR_WRITE_ATOMIC;
+	}
+}
+EXPORT_SYMBOL_GPL(generic_fill_statx_atomic_writes);
+
+/**
  * vfs_getattr_nosec - getattr without security checks
  * @path: file to get attributes from
  * @stat: structure to return attributes in
@@ -231,13 +262,13 @@ static int vfs_statx_path(struct path *path, int flags, struct kstat *stat,
 		stat->attributes |= STATX_ATTR_MOUNT_ROOT;
 	stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT;
 
-	/* Handle STATX_DIOALIGN for block devices. */
-	if (request_mask & STATX_DIOALIGN) {
-		struct inode *inode = d_backing_inode(path->dentry);
-
-		if (S_ISBLK(inode->i_mode))
-			bdev_statx_dioalign(inode, stat);
-	}
+	/*
+	 * If this is a block device inode, override the filesystem
+	 * attributes with the block device specific parameters that need to be
+	 * obtained from the bdev backing inode.
+	 */
+	if (S_ISBLK(stat->mode))
+		bdev_statx(path, stat, request_mask);
 
 	return error;
 }
@@ -670,6 +701,9 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer)
 	tmp.stx_dio_mem_align = stat->dio_mem_align;
 	tmp.stx_dio_offset_align = stat->dio_offset_align;
 	tmp.stx_subvol = stat->subvol;
+	tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
+	tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
+	tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;
 
 	return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }