Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:51511 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753099Ab3ILQD0 (ORCPT ); Thu, 12 Sep 2013 12:03:26 -0400 Date: Thu, 12 Sep 2013 12:03:24 -0400 To: linux-fsdevel@vger.kernel.org Cc: Al Viro , linux-nfs@vger.kernel.org, sandeen@redhat.com Subject: why is i_ino unsigned long, anyway? Message-ID: <20130912160324.GE1462@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: Somebody noticed an "ls -l" over nfs failing on entries with inode numbers greater than 2^32 on a 32-bit NFS server. The cause is some code that tries to compare i_ino to the full 64-bit inode number. I think the following will fix it, but I'm curious: why is i_ino "unsigned long", anyway? Is there something know that depends on that, or is it just that the sheer number of users makes it too scary to change? --b. commit 0cc784eb430285535ae7a79dd5133ab66e9ce839 Author: J. Bruce Fields Date: Tue Sep 10 11:41:12 2013 -0400 exportfs: fix 32-bit nfsd handling of 64-bit inode numbers Symptoms were spurious -ENOENTs on stat of an NFS filesystem from a 32-bit NFS server exporting a very large XFS filesystem, when the server's cache is cold (so the inodes in question are not in cache). Signed-off-by: J. Bruce Fields diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 293bc2e..6a79bb8 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -215,7 +215,7 @@ struct getdents_callback { struct dir_context ctx; char *name; /* name that was found. It already points to a buffer NAME_MAX+1 is size */ - unsigned long ino; /* the inum we are looking for */ + u64 ino; /* the inum we are looking for */ int found; /* inode matched? */ int sequence; /* sequence counter */ }; @@ -255,10 +255,10 @@ static int get_name(const struct path *path, char *name, struct dentry *child) struct inode *dir = path->dentry->d_inode; int error; struct file *file; + struct kstat stat; struct getdents_callback buffer = { .ctx.actor = filldir_one, .name = name, - .ino = child->d_inode->i_ino }; error = -ENOTDIR; @@ -268,6 +268,16 @@ static int get_name(const struct path *path, char *name, struct dentry *child) if (!dir->i_fop) goto out; /* + * inode->i_ino is unsigned long, kstat->ino is u64, so the + * former would be insufficient on 32-bit hosts when the + * filesystem supports 64-bit inode numbers. So we need to + * actually call ->getattr, not just read i_ino: + */ + error = vfs_getattr(path, &stat); + if (error) + return error; + buffer.ino = stat.ino; + /* * Open the directory ... */ file = dentry_open(path, O_RDONLY, cred);