Unionfs: update times in setattr

Needed to maintain Unix semantics via utimes(2).

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/inode.c b/fs/unionfs/inode.c
index 149f7032744d138ebee81e5aa40f0b0baacbded7..7cc75320dc08d1aa5b7b77a0b8980827627ed50e 100644 (file)
--- a/fs/unionfs/inode.c
+++ b/fs/unionfs/inode.c
@@ -910,6 +910,18 @@ static int unionfs_setattr(struct dentry *dentry, struct iattr *ia)
        /* get the size from the first lower inode */
        lower_inode = unionfs_lower_inode(inode);
        unionfs_copy_attr_all(inode, lower_inode);
+       /*
+        * unionfs_copy_attr_all will copy the lower times to our inode if
+        * the lower ones are newer (useful for cache coherency).  However,
+        * ->setattr is the only place in which we may have to copy the
+        * lower inode times absolutely, to support utimes(2).
+        */
+       if (ia->ia_valid & ATTR_MTIME_SET)
+               inode->i_mtime = lower_inode->i_mtime;
+       if (ia->ia_valid & ATTR_CTIME)
+               inode->i_ctime = lower_inode->i_ctime;
+       if (ia->ia_valid & ATTR_ATIME_SET)
+               inode->i_atime = lower_inode->i_atime;
        fsstack_copy_inode_size(inode, lower_inode);
        /* if setattr succeeded, then parent dir may have changed */
        unionfs_copy_attr_times(dentry->d_parent->d_inode);