From: Bryan Donlan Subject: [PATCH v2] ext[234]: Return -EIO not -ESTALE on directory traversal through deleted inode Date: Mon, 16 Feb 2009 20:10:03 -0500 Message-ID: <1234833003-19631-1-git-send-email-bdonlan@gmail.com> References: <20090214141411.GD26628@mini-me.lan> Cc: sct@redhat.com, akpm@linux-foundation.org, adilger@sun.com, tytso@mit.edu, Bryan Donlan To: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from satoko.is.fushizen.net ([207.192.69.114]:49642 "EHLO satoko.is.fushizen.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750721AbZBQBKH (ORCPT ); Mon, 16 Feb 2009 20:10:07 -0500 In-Reply-To: <20090214141411.GD26628@mini-me.lan> Sender: linux-ext4-owner@vger.kernel.org List-ID: The ext[234]_iget() functions in the ext[234] family of filesystems returns -ESTALE if invoked on a deleted inode, in order to report errors to NFS properly. However, in ext[234]_lookup(), this -ESTALE can be propagated to userspace if the filesystem is corrupted such that a directory entry references a deleted inode. This leads to a misleading error message - "Stale NFS file handle" - and confusion on the part of the admin. The bug can be easily reproduced by creating a new filesystem, making a link to an unused inode using debugfs, then mounting and attempting to ls -l said link. This patch thus changes ext[234]_lookup to return -EIO if it receives -ESTALE from ext[234]_iget(), as ext[234] does for other filesystem metadata corruption; and also invokes the appropriate ext*_error functions when this case is detected. Signed-off-by: Bryan Donlan --- fs/ext2/namei.c | 12 ++++++++++-- fs/ext3/namei.c | 12 ++++++++++-- fs/ext4/namei.c | 12 ++++++++++-- 3 files changed, 30 insertions(+), 6 deletions(-) diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c index 90ea179..e3d2d34 100644 --- a/fs/ext2/namei.c +++ b/fs/ext2/namei.c @@ -66,8 +66,16 @@ static struct dentry *ext2_lookup(struct inode * dir, struct dentry *dentry, str inode = NULL; if (ino) { inode = ext2_iget(dir->i_sb, ino); - if (IS_ERR(inode)) - return ERR_CAST(inode); + if (unlikely(IS_ERR(inode))) { + if (PTR_ERR(inode) == -ESTALE) { + ext2_error(dir->i_sb, "ext2_lookup", + "deleted inode referenced: %lu", + ino); + return ERR_PTR(-EIO); + } else { + return ERR_CAST(inode); + } + } } return d_splice_alias(inode, dentry); } diff --git a/fs/ext3/namei.c b/fs/ext3/namei.c index 4db4ffa..7a99af0 100644 --- a/fs/ext3/namei.c +++ b/fs/ext3/namei.c @@ -1047,8 +1047,16 @@ static struct dentry *ext3_lookup(struct inode * dir, struct dentry *dentry, str return ERR_PTR(-EIO); } inode = ext3_iget(dir->i_sb, ino); - if (IS_ERR(inode)) - return ERR_CAST(inode); + if (unlikely(IS_ERR(inode))) { + if (PTR_ERR(inode) == -ESTALE) { + ext3_error(dir->i_sb, "ext2_lookup", + "deleted inode referenced: %lu", + ino); + return ERR_PTR(-EIO); + } else { + return ERR_CAST(inode); + } + } } return d_splice_alias(inode, dentry); } diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index ba702bd..a61637b 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1052,8 +1052,16 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, stru return ERR_PTR(-EIO); } inode = ext4_iget(dir->i_sb, ino); - if (IS_ERR(inode)) - return ERR_CAST(inode); + if (unlikely(IS_ERR(inode))) { + if (PTR_ERR(inode) == -ESTALE) { + ext4_error(dir->i_sb, "ext2_lookup", + "deleted inode referenced: %u", + ino); + return ERR_PTR(-EIO); + } else { + return ERR_CAST(inode); + } + } } return d_splice_alias(inode, dentry); } -- 1.5.6.3