From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: [patch 089/104] ext4: fix xattr deadlock Date: Wed, 3 Dec 2008 11:56:26 -0800 Message-ID: <20081203195626.GL8950@kroah.com> References: <20081203193901.715896543@mini.kroah.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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, Kalpak Shah , Ext4 Developers List To: linux-kernel@vger.kernel.org, stable@kernel.org Return-path: Received: from kroah.org ([198.145.64.141]:56667 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756102AbYLCT5y (ORCPT ); Wed, 3 Dec 2008 14:57:54 -0500 Content-Disposition: inline; filename="ext4-fix-xattr-deadlock.patch" In-Reply-To: <20081203194725.GA8950@kroah.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Kalpak Shah (cherry picked from commit 4d20c685fa365766a8f13584b4c8178a15ab7103) ext4_xattr_set_handle() eventually ends up calling ext4_mark_inode_dirty() which tries to expand the inode by shifting the EAs. This leads to the xattr_sem being downed again and leading to a deadlock. This patch makes sure that if ext4_xattr_set_handle() is in the call-chain, ext4_mark_inode_dirty() will not expand the inode. Signed-off-by: Kalpak Shah Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/xattr.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -959,6 +959,7 @@ ext4_xattr_set_handle(handle_t *handle, struct ext4_xattr_block_find bs = { .s = { .not_found = -ENODATA, }, }; + unsigned long no_expand; int error; if (!name) @@ -966,6 +967,9 @@ ext4_xattr_set_handle(handle_t *handle, if (strlen(name) > 255) return -ERANGE; down_write(&EXT4_I(inode)->xattr_sem); + no_expand = EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND; + EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND; + error = ext4_get_inode_loc(inode, &is.iloc); if (error) goto cleanup; @@ -1042,6 +1046,8 @@ ext4_xattr_set_handle(handle_t *handle, cleanup: brelse(is.iloc.bh); brelse(bs.bh); + if (no_expand == 0) + EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND; up_write(&EXT4_I(inode)->xattr_sem); return error; }