From: Theodore Ts'o Subject: [PATCH,STABLE 2.6.29 03/18] ext4: return -EIO not -ESTALE on directory traversal through deleted inode Date: Tue, 2 Jun 2009 08:07:44 -0400 Message-ID: <1243944479-20574-3-git-send-email-tytso@mit.edu> References: <1243944479-20574-1-git-send-email-tytso@mit.edu> <1243944479-20574-2-git-send-email-tytso@mit.edu> Cc: linux-ext4@vger.kernel.org, Bryan Donlan , Andrew Morton , "Theodore Ts'o" To: stable@kernel.org Return-path: Received: from thunk.org ([69.25.196.29]:33515 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751668AbZFBMIK (ORCPT ); Tue, 2 Jun 2009 08:08:10 -0400 In-Reply-To: <1243944479-20574-2-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Bryan Donlan ext4_iget() returns -ESTALE if invoked on a deleted inode, in order to report errors to NFS properly. However, in ext4_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 ext4_lookup to return -EIO if it receives -ESTALE from ext4_iget(), as ext4 does for other filesystem metadata corruption; and also invokes the appropriate ext*_error functions when this case is detected. Signed-off-by: Bryan Donlan Cc: Signed-off-by: Andrew Morton Signed-off-by: "Theodore Ts'o" (cherry picked from commit e6f009b0b45220c004672d41a58865e94946104d) --- fs/ext4/namei.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index ba702bd..f787234 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, __func__, + "deleted inode referenced: %u", + ino); + return ERR_PTR(-EIO); + } else { + return ERR_CAST(inode); + } + } } return d_splice_alias(inode, dentry); } -- 1.6.3.1.1.g75fc.dirty