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-rw-r--r--fs/overlayfs/util.c32
1 files changed, 31 insertions, 1 deletions
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 5fdaa9408c84..10032f7c5aa3 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -470,7 +470,7 @@ static void ovl_dir_version_inc(struct dentry *dentry, bool impurity)
void ovl_dir_modified(struct dentry *dentry, bool impurity)
{
/* Copy mtime/ctime */
- ovl_copyattr(d_inode(ovl_dentry_upper(dentry)), d_inode(dentry));
+ ovl_copyattr(d_inode(dentry));
ovl_dir_version_inc(dentry, impurity);
}
@@ -1086,3 +1086,33 @@ int ovl_sync_status(struct ovl_fs *ofs)
return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq);
}
+
+/*
+ * ovl_copyattr() - copy inode attributes from layer to ovl inode
+ *
+ * When overlay copies inode information from an upper or lower layer to the
+ * relevant overlay inode it will apply the idmapping of the upper or lower
+ * layer when doing so ensuring that the ovl inode ownership will correctly
+ * reflect the ownership of the idmapped upper or lower layer. For example, an
+ * idmapped upper or lower layer mapping id 1001 to id 1000 will take care to
+ * map any lower or upper inode owned by id 1001 to id 1000. These mapping
+ * helpers are nops when the relevant layer isn't idmapped.
+ */
+void ovl_copyattr(struct inode *inode)
+{
+ struct path realpath;
+ struct inode *realinode;
+ struct user_namespace *real_mnt_userns;
+
+ ovl_i_path_real(inode, &realpath);
+ realinode = d_inode(realpath.dentry);
+ real_mnt_userns = mnt_user_ns(realpath.mnt);
+
+ inode->i_uid = i_uid_into_mnt(real_mnt_userns, realinode);
+ inode->i_gid = i_gid_into_mnt(real_mnt_userns, realinode);
+ inode->i_mode = realinode->i_mode;
+ inode->i_atime = realinode->i_atime;
+ inode->i_mtime = realinode->i_mtime;
+ inode->i_ctime = realinode->i_ctime;
+ i_size_write(inode, i_size_read(realinode));
+}