default to simple_setattr

With the new truncate sequence every filesystem that wants to support file
size changes on disk needs to implement its own ->setattr.  So instead
of calling inode_setattr which supports size changes call into a simple
method that doesn't support this.  simple_setattr is almost what we
want except that it does not mark the inode dirty after changes.  Given
that marking the inode dirty is a no-op for the simple in-memory filesystems
that use simple_setattr currently just add the mark_inode_dirty call.

Also add a WARN_ON for the presence of a truncate method to simple_setattr
to catch new instances of it during the transition period.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 3 insertions, 6 deletions

diff --git a/fs/attr.c b/fs/attr.c
index 1f6a895e24e9..aeac826f4774 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -237,13 +237,10 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
         if (ia_valid & ATTR_SIZE)
                 down_write(&dentry->d_inode->i_alloc_sem);
 
-        if (inode->i_op && inode->i_op->setattr) {
+        if (inode->i_op->setattr)
                 error = inode->i_op->setattr(dentry, attr);
-        } else {
-                error = inode_change_ok(inode, attr);
-                if (!error)
-                        error = inode_setattr(inode, attr);
-        }
+        else
+                error = simple_setattr(dentry, attr);
 
         if (ia_valid & ATTR_SIZE)
                 up_write(&dentry->d_inode->i_alloc_sem);