From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756967AbZFJDna (ORCPT ); Tue, 9 Jun 2009 23:43:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757436AbZFJDfu (ORCPT ); Tue, 9 Jun 2009 23:35:50 -0400 Received: from kroah.org ([198.145.64.141]:57178 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757466AbZFJDfs (ORCPT ); Tue, 9 Jun 2009 23:35:48 -0400 X-Mailbox-Line: From greg@blue.kroah.org Tue Jun 9 17:23:48 2009 Message-Id: <20090610002348.220859343@blue.kroah.org> User-Agent: quilt/0.48-1 Date: Tue, 09 Jun 2009 17:14:05 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.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, Eric Sandeen , linux-ext4@vger.kernel.org, Greg Kroah-Hartman Subject: [patch 37/60] ext4: fix ext4_free_inode() vs. ext4_claim_inode() race References: <20090610001328.251476848@blue.kroah.org> Content-Disposition: inline; filename=ext4-fix-ext4_free_inode-vs.-ext4_claim_inode-race.patch In-Reply-To: <20090610032135.GA19346@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -stable review patch. If anyone has any objections, please let us know. ------------------ From: Eric Sandeen (cherry picked from commit 7ce9d5d1f3c8736511daa413c64985a05b2feee3) I was seeing fsck errors on inode bitmaps after a 4 thread dbench run on a 4 cpu machine: Inode bitmap differences: -50736 -(50752--50753) etc... I believe that this is because ext4_free_inode() uses atomic bitops, and although ext4_new_inode() *used* to also use atomic bitops for synchronization, commit 393418676a7602e1d7d3f6e560159c65c8cbd50e changed this to use the sb_bgl_lock, so that we could also synchronize against read_inode_bitmap and initialization of uninit inode tables. However, that change left ext4_free_inode using atomic bitops, which I think leaves no synchronization between setting & unsetting bits in the inode table. The below patch fixes it for me, although I wonder if we're getting at all heavy-handed with this spinlock... Signed-off-by: Eric Sandeen Reviewed-by: Aneesh Kumar K.V Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ialloc.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -188,7 +188,7 @@ void ext4_free_inode (handle_t *handle, struct ext4_group_desc * gdp; struct ext4_super_block * es; struct ext4_sb_info *sbi; - int fatal = 0, err; + int fatal = 0, err, cleared; ext4_group_t flex_group; if (atomic_read(&inode->i_count) > 1) { @@ -242,10 +242,12 @@ void ext4_free_inode (handle_t *handle, goto error_return; /* Ok, now we can actually update the inode bitmaps.. */ - if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group), - bit, bitmap_bh->b_data)) - ext4_error (sb, "ext4_free_inode", - "bit already cleared for inode %lu", ino); + spin_lock(sb_bgl_lock(sbi, block_group)); + cleared = ext4_clear_bit(bit, bitmap_bh->b_data); + spin_unlock(sb_bgl_lock(sbi, block_group)); + if (!cleared) + ext4_error(sb, "ext4_free_inode", + "bit already cleared for inode %lu", ino); else { gdp = ext4_get_group_desc (sb, block_group, &bh2);