From: Greg KH Subject: [patch 44/60] ext4: return -EIO not -ESTALE on directory traversal through deleted inode Date: Tue, 09 Jun 2009 17:14:12 -0700 Message-ID: <20090610002349.812972018@blue.kroah.org> References: <20090610001328.251476848@blue.kroah.org> Cc: Justin Forbes , Zwane Mwaikambo , Theodore Ts'o , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, linux-ext4@vger.kernel.org, Bryan Donlan , Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:57307 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757601AbZFJDgN (ORCPT ); Tue, 9 Jun 2009 23:36:13 -0400 Content-Disposition: inline; filename=ext4-return-eio-not-estale-on-directory-traversal-through-deleted-inode.patch In-Reply-To: <20090610032135.GA19346@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: -stable review patch. If anyone has any objections, please let us know. ------------------ From: Bryan Donlan (cherry picked from commit e6f009b0b45220c004672d41a58865e94946104d) 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" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/namei.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1055,8 +1055,16 @@ static struct dentry *ext4_lookup(struct 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); }