提交 81be24d2 编写于 作者: A Al Viro 提交者: Al Viro

Hang/soft lockup in d_invalidate with simultaneous calls

It's not hard to trigger a bunch of d_invalidate() on the same
dentry in parallel.  They end up fighting each other - any
dentry picked for removal by one will be skipped by the rest
and we'll go for the next iteration through the entire
subtree, even if everything is being skipped.  Morevoer, we
immediately go back to scanning the subtree.  The only thing
we really need is to dissolve all mounts in the subtree and
as soon as we've nothing left to do, we can just unhash the
dentry and bugger off.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
上级 32c1431e
......@@ -1494,7 +1494,7 @@ static void check_and_drop(void *_data)
{
struct detach_data *data = _data;
if (!data->mountpoint && !data->select.found)
if (!data->mountpoint && list_empty(&data->select.dispose))
__d_drop(data->select.start);
}
......@@ -1536,17 +1536,15 @@ void d_invalidate(struct dentry *dentry)
d_walk(dentry, &data, detach_and_collect, check_and_drop);
if (data.select.found)
if (!list_empty(&data.select.dispose))
shrink_dentry_list(&data.select.dispose);
else if (!data.mountpoint)
return;
if (data.mountpoint) {
detach_mounts(data.mountpoint);
dput(data.mountpoint);
}
if (!data.mountpoint && !data.select.found)
break;
cond_resched();
}
}
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册