1 files changed, 50 insertions, 9 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 6b7652fb8050..6931308876c4 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -91,9 +91,12 @@ static ssize_t sysfs_kf_bin_read(struct kernfs_open_file *of, char *buf,
 			count = size - pos;
 	}
 
-	if (!battr->read)
+	if (!battr->read && !battr->read_new)
 		return -EIO;
 
+	if (battr->read_new)
+		return battr->read_new(of->file, kobj, battr, buf, pos, count);
+
 	return battr->read(of->file, kobj, battr, buf, pos, count);
 }
 
@@ -152,9 +155,12 @@ static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
 	if (!count)
 		return 0;
 
-	if (!battr->write)
+	if (!battr->write && !battr->write_new)
 		return -EIO;
 
+	if (battr->write_new)
+		return battr->write_new(of->file, kobj, battr, buf, pos, count);
+
 	return battr->write(of->file, kobj, battr, buf, pos, count);
 }
 
@@ -315,7 +321,7 @@ int sysfs_add_file_mode_ns(struct kernfs_node *parent,
 }
 
 int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
-		const struct bin_attribute *battr, umode_t mode,
+		const struct bin_attribute *battr, umode_t mode, size_t size,
 		kuid_t uid, kgid_t gid, const void *ns)
 {
 	const struct attribute *attr = &battr->attr;
@@ -323,13 +329,19 @@ int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
 	const struct kernfs_ops *ops;
 	struct kernfs_node *kn;
 
+	if (battr->read && battr->read_new)
+		return -EINVAL;
+
+	if (battr->write && battr->write_new)
+		return -EINVAL;
+
 	if (battr->mmap)
 		ops = &sysfs_bin_kfops_mmap;
-	else if (battr->read && battr->write)
+	else if ((battr->read || battr->read_new) && (battr->write || battr->write_new))
 		ops = &sysfs_bin_kfops_rw;
-	else if (battr->read)
+	else if (battr->read || battr->read_new)
 		ops = &sysfs_bin_kfops_ro;
-	else if (battr->write)
+	else if (battr->write || battr->write_new)
 		ops = &sysfs_bin_kfops_wo;
 	else
 		ops = &sysfs_file_kfops_empty;
@@ -340,7 +352,7 @@ int sysfs_add_bin_file_mode_ns(struct kernfs_node *parent,
 #endif
 
 	kn = __kernfs_create_file(parent, attr->name, mode & 0777, uid, gid,
-				  battr->size, ops, (void *)attr, ns, key);
+				  size, ops, (void *)attr, ns, key);
 	if (IS_ERR(kn)) {
 		if (PTR_ERR(kn) == -EEXIST)
 			sysfs_warn_dup(parent, attr->name);
@@ -463,6 +475,8 @@ struct kernfs_node *sysfs_break_active_protection(struct kobject *kobj,
 	kn = kernfs_find_and_get(kobj->sd, attr->name);
 	if (kn)
 		kernfs_break_active_protection(kn);
+	else
+		kobject_put(kobj);
 	return kn;
 }
 EXPORT_SYMBOL_GPL(sysfs_break_active_protection);
@@ -578,8 +592,8 @@ int sysfs_create_bin_file(struct kobject *kobj,
 		return -EINVAL;
 
 	kobject_get_ownership(kobj, &uid, &gid);
-	return sysfs_add_bin_file_mode_ns(kobj->sd, attr, attr->attr.mode, uid,
-					   gid, NULL);
+	return sysfs_add_bin_file_mode_ns(kobj->sd, attr, attr->attr.mode,
+					  attr->size, uid, gid, NULL);
 }
 EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
 
@@ -783,3 +797,30 @@ int sysfs_emit_at(char *buf, int at, const char *fmt, ...)
 	return len;
 }
 EXPORT_SYMBOL_GPL(sysfs_emit_at);
+
+/**
+ *	sysfs_bin_attr_simple_read - read callback to simply copy from memory.
+ *	@file:	attribute file which is being read.
+ *	@kobj:	object to which the attribute belongs.
+ *	@attr:	attribute descriptor.
+ *	@buf:	destination buffer.
+ *	@off:	offset in bytes from which to read.
+ *	@count:	maximum number of bytes to read.
+ *
+ * Simple ->read() callback for bin_attributes backed by a buffer in memory.
+ * The @private and @size members in struct bin_attribute must be set to the
+ * buffer's location and size before the bin_attribute is created in sysfs.
+ *
+ * Bounds check for @off and @count is done in sysfs_kf_bin_read().
+ * Negative value check for @off is done in vfs_setpos() and default_llseek().
+ *
+ * Returns number of bytes written to @buf.
+ */
+ssize_t sysfs_bin_attr_simple_read(struct file *file, struct kobject *kobj,
+				   const struct bin_attribute *attr, char *buf,
+				   loff_t off, size_t count)
+{
+	memcpy(buf, attr->private + off, count);
+	return count;
+}
+EXPORT_SYMBOL_GPL(sysfs_bin_attr_simple_read);