ovl: copy up times

Copy up mtime and ctime to overlay inode after times in real object are
modified.  Be careful not to dirty cachelines when not necessary.

This is in preparation for moving overlay functionality out of the VFS.

This patch shouldn't have any observable effect.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

1 files changed, 24 insertions, 7 deletions

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index f480b1a2cd2e..4fa756c1b190 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -242,7 +242,7 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode,
 		.newinode = inode,
 	};
 
-	ovl_dentry_version_inc(dentry->d_parent, false);
+	ovl_dir_modified(dentry->d_parent, false);
 	ovl_dentry_set_upper_alias(dentry);
 	if (!hardlink) {
 		/*
@@ -722,7 +722,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry,
 	if (err)
 		goto out_d_drop;
 
-	ovl_dentry_version_inc(dentry->d_parent, true);
+	ovl_dir_modified(dentry->d_parent, true);
 out_d_drop:
 	d_drop(dentry);
 out_dput_upper:
@@ -767,7 +767,7 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir,
 		err = vfs_rmdir(dir, upper);
 	else
 		err = vfs_unlink(dir, upper, NULL);
-	ovl_dentry_version_inc(dentry->d_parent, ovl_type_origin(dentry));
+	ovl_dir_modified(dentry->d_parent, ovl_type_origin(dentry));
 
 	/*
 	 * Keeping this dentry hashed would mean having to release
@@ -797,6 +797,7 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
 	int err;
 	bool locked = false;
 	const struct cred *old_cred;
+	struct dentry *upperdentry;
 	bool lower_positive = ovl_lower_positive(dentry);
 	LIST_HEAD(list);
 
@@ -832,6 +833,17 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir)
 			drop_nlink(dentry->d_inode);
 	}
 	ovl_nlink_end(dentry, locked);
+
+	/*
+	 * Copy ctime
+	 *
+	 * Note: we fail to update ctime if there was no copy-up, only a
+	 * whiteout
+	 */
+	upperdentry = ovl_dentry_upper(dentry);
+	if (upperdentry)
+		ovl_copyattr(d_inode(upperdentry), d_inode(dentry));
+
 out_drop_write:
 	ovl_drop_write(dentry);
 out:
@@ -1138,10 +1150,15 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
 			drop_nlink(d_inode(new));
 	}
 
-	ovl_dentry_version_inc(old->d_parent, ovl_type_origin(old) ||
-			       (!overwrite && ovl_type_origin(new)));
-	ovl_dentry_version_inc(new->d_parent, ovl_type_origin(old) ||
-			       (d_inode(new) && ovl_type_origin(new)));
+	ovl_dir_modified(old->d_parent, ovl_type_origin(old) ||
+			 (!overwrite && ovl_type_origin(new)));
+	ovl_dir_modified(new->d_parent, ovl_type_origin(old) ||
+			 (d_inode(new) && ovl_type_origin(new)));
+
+	/* copy ctime: */
+	ovl_copyattr(d_inode(olddentry), d_inode(old));
+	if (d_inode(new) && ovl_dentry_upper(new))
+		ovl_copyattr(d_inode(newdentry), d_inode(new));
 
 out_dput:
 	dput(newdentry);