[PATCH v7 1/7] kernfs: clean up struct kernfs_iattrs

[Ondrej Mosnacek]

Right now, kernfs_iattrs embeds the whole struct iattr, even though it
doesn't really use half of its fields... This both leads to wasting
space and makes the code look awkward. Let's just list the few fields
we need directly in struct kernfs_iattrs.

Signed-off-by: Ondrej Mosnacek <omosnace at redhat.com>
---
 fs/kernfs/dir.c             | 10 ++++----
 fs/kernfs/inode.c           | 47 ++++++++++++++++---------------------
 fs/kernfs/kernfs-internal.h |  6 ++++-
 fs/kernfs/symlink.c         |  4 ++--
 4 files changed, 31 insertions(+), 36 deletions(-)

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 4ca0b5c18192..e3e00d9be70d 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -795,9 +795,8 @@ int kernfs_add_one(struct kernfs_node *kn)
 	/* Update timestamps on the parent */
 	ps_iattr = parent->iattr;
 	if (ps_iattr) {
-		struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
-		ktime_get_real_ts64(&ps_iattrs->ia_ctime);
-		ps_iattrs->ia_mtime = ps_iattrs->ia_ctime;
+		ktime_get_real_ts64(&ps_iattr->ia_ctime);
+		ps_iattr->ia_mtime = ps_iattr->ia_ctime;
 	}
 
 	mutex_unlock(&kernfs_mutex);
@@ -1329,9 +1328,8 @@ static void __kernfs_remove(struct kernfs_node *kn)
 
 			/* update timestamps on the parent */
 			if (ps_iattr) {
-				ktime_get_real_ts64(&ps_iattr->ia_iattr.ia_ctime);
-				ps_iattr->ia_iattr.ia_mtime =
-					ps_iattr->ia_iattr.ia_ctime;
+				ktime_get_real_ts64(&ps_iattr->ia_ctime);
+				ps_iattr->ia_mtime = ps_iattr->ia_ctime;
 			}
 
 			kernfs_put(pos);
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 80cebcd94c90..ffd1ef962728 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -35,7 +35,6 @@ static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
 {
 	static DEFINE_MUTEX(iattr_mutex);
 	struct kernfs_iattrs *ret;
-	struct iattr *iattrs;
 
 	mutex_lock(&iattr_mutex);
 
@@ -45,16 +44,14 @@ static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
 	kn->iattr = kzalloc(sizeof(struct kernfs_iattrs), GFP_KERNEL);
 	if (!kn->iattr)
 		goto out_unlock;
-	iattrs = &kn->iattr->ia_iattr;
 
 	/* assign default attributes */
-	iattrs->ia_mode = kn->mode;
-	iattrs->ia_uid = GLOBAL_ROOT_UID;
-	iattrs->ia_gid = GLOBAL_ROOT_GID;
+	kn->iattr->ia_uid = GLOBAL_ROOT_UID;
+	kn->iattr->ia_gid = GLOBAL_ROOT_GID;
 
-	ktime_get_real_ts64(&iattrs->ia_atime);
-	iattrs->ia_mtime = iattrs->ia_atime;
-	iattrs->ia_ctime = iattrs->ia_atime;
+	ktime_get_real_ts64(&kn->iattr->ia_atime);
+	kn->iattr->ia_mtime = kn->iattr->ia_atime;
+	kn->iattr->ia_ctime = kn->iattr->ia_atime;
 
 	simple_xattrs_init(&kn->iattr->xattrs);
 out_unlock:
@@ -66,29 +63,24 @@ out_unlock:
 int __kernfs_setattr(struct kernfs_node *kn, const struct iattr *iattr)
 {
 	struct kernfs_iattrs *attrs;
-	struct iattr *iattrs;
 	unsigned int ia_valid = iattr->ia_valid;
 
 	attrs = kernfs_iattrs(kn);
 	if (!attrs)
 		return -ENOMEM;
 
-	iattrs = &attrs->ia_iattr;
-
 	if (ia_valid & ATTR_UID)
-		iattrs->ia_uid = iattr->ia_uid;
+		attrs->ia_uid = iattr->ia_uid;
 	if (ia_valid & ATTR_GID)
-		iattrs->ia_gid = iattr->ia_gid;
+		attrs->ia_gid = iattr->ia_gid;
 	if (ia_valid & ATTR_ATIME)
-		iattrs->ia_atime = iattr->ia_atime;
+		attrs->ia_atime = iattr->ia_atime;
 	if (ia_valid & ATTR_MTIME)
-		iattrs->ia_mtime = iattr->ia_mtime;
+		attrs->ia_mtime = iattr->ia_mtime;
 	if (ia_valid & ATTR_CTIME)
-		iattrs->ia_ctime = iattr->ia_ctime;
-	if (ia_valid & ATTR_MODE) {
-		umode_t mode = iattr->ia_mode;
-		iattrs->ia_mode = kn->mode = mode;
-	}
+		attrs->ia_ctime = iattr->ia_ctime;
+	if (ia_valid & ATTR_MODE)
+		kn->mode = iattr->ia_mode;
 	return 0;
 }
 
@@ -171,14 +163,15 @@ static inline void set_default_inode_attr(struct inode *inode, umode_t mode)
 		inode->i_ctime = current_time(inode);
 }
 
-static inline void set_inode_attr(struct inode *inode, struct iattr *iattr)
+static inline void set_inode_attr(struct inode *inode,
+				  struct kernfs_iattrs *attrs)
 {
 	struct super_block *sb = inode->i_sb;
-	inode->i_uid = iattr->ia_uid;
-	inode->i_gid = iattr->ia_gid;
-	inode->i_atime = timespec64_trunc(iattr->ia_atime, sb->s_time_gran);
-	inode->i_mtime = timespec64_trunc(iattr->ia_mtime, sb->s_time_gran);
-	inode->i_ctime = timespec64_trunc(iattr->ia_ctime, sb->s_time_gran);
+	inode->i_uid = attrs->ia_uid;
+	inode->i_gid = attrs->ia_gid;
+	inode->i_atime = timespec64_trunc(attrs->ia_atime, sb->s_time_gran);
+	inode->i_mtime = timespec64_trunc(attrs->ia_mtime, sb->s_time_gran);
+	inode->i_ctime = timespec64_trunc(attrs->ia_ctime, sb->s_time_gran);
 }
 
 static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
@@ -191,7 +184,7 @@ static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
 		 * kernfs_node has non-default attributes get them from
 		 * persistent copy in kernfs_node.
 		 */
-		set_inode_attr(inode, &attrs->ia_iattr);
+		set_inode_attr(inode, attrs);
 		security_inode_notifysecctx(inode, attrs->ia_secdata,
 					    attrs->ia_secdata_len);
 	}
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 3d83b114bb08..388c1193c4fa 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -19,7 +19,11 @@
 #include <linux/kernfs.h>
 
 struct kernfs_iattrs {
-	struct iattr		ia_iattr;
+	kuid_t			ia_uid;
+	kgid_t			ia_gid;
+	struct timespec64	ia_atime;
+	struct timespec64	ia_mtime;
+	struct timespec64	ia_ctime;
 	void			*ia_secdata;
 	u32			ia_secdata_len;
 
diff --git a/fs/kernfs/symlink.c b/fs/kernfs/symlink.c
index 162f43b80c84..eb46c3a16e2f 100644
--- a/fs/kernfs/symlink.c
+++ b/fs/kernfs/symlink.c
@@ -33,8 +33,8 @@ struct kernfs_node *kernfs_create_link(struct kernfs_node *parent,
 	kgid_t gid = GLOBAL_ROOT_GID;
 
 	if (target->iattr) {
-		uid = target->iattr->ia_iattr.ia_uid;
-		gid = target->iattr->ia_iattr.ia_gid;
+		uid = target->iattr->ia_uid;
+		gid = target->iattr->ia_gid;
 	}
 
 	kn = kernfs_new_node(parent, name, S_IFLNK|S_IRWXUGO, uid, gid,
-- 
2.20.1