From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932841Ab1CZAEx (ORCPT ); Fri, 25 Mar 2011 20:04:53 -0400 Received: from kroah.org ([198.145.64.141]:41910 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932579Ab1CYXxC (ORCPT ); Fri, 25 Mar 2011 19:53:02 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Mar 25 16:45:13 2011 Message-Id: <20110325234513.104015172@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Fri, 25 Mar 2011 16:44:26 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jens Axboe Subject: [50/63] fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away In-Reply-To: <20110325234526.GA18017@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.38-stable review patch. If anyone has any objections, please let us know. ------------------ From: Jens Axboe commit 95f28604a65b1c40b6c6cd95e58439cd7ded3add upstream. We don't have proper reference counting for this yet, so we run into cases where the device is pulled and we OOPS on flushing the fs data. This happens even though the dirty inodes have already been migrated to the default_backing_dev_info. Reported-by: Torsten Hilbrich Tested-by: Torsten Hilbrich Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/super.c | 2 ++ fs/sync.c | 4 ++-- mm/backing-dev.c | 2 +- 3 files changed, 5 insertions(+), 3 deletions(-) --- a/fs/super.c +++ b/fs/super.c @@ -71,6 +71,7 @@ static struct super_block *alloc_super(s #else INIT_LIST_HEAD(&s->s_files); #endif + s->s_bdi = &default_backing_dev_info; INIT_LIST_HEAD(&s->s_instances); INIT_HLIST_BL_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); @@ -1003,6 +1004,7 @@ vfs_kern_mount(struct file_system_type * } BUG_ON(!mnt->mnt_sb); WARN_ON(!mnt->mnt_sb->s_bdi); + WARN_ON(mnt->mnt_sb->s_bdi == &default_backing_dev_info); mnt->mnt_sb->s_flags |= MS_BORN; error = security_sb_kern_mount(mnt->mnt_sb, flags, secdata); --- a/fs/sync.c +++ b/fs/sync.c @@ -33,7 +33,7 @@ static int __sync_filesystem(struct supe * This should be safe, as we require bdi backing to actually * write out data in the first place */ - if (!sb->s_bdi || sb->s_bdi == &noop_backing_dev_info) + if (sb->s_bdi == &noop_backing_dev_info) return 0; if (sb->s_qcop && sb->s_qcop->quota_sync) @@ -79,7 +79,7 @@ EXPORT_SYMBOL_GPL(sync_filesystem); static void sync_one_sb(struct super_block *sb, void *arg) { - if (!(sb->s_flags & MS_RDONLY) && sb->s_bdi) + if (!(sb->s_flags & MS_RDONLY)) __sync_filesystem(sb, *(int *)arg); } /* --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -604,7 +604,7 @@ static void bdi_prune_sb(struct backing_ spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) { if (sb->s_bdi == bdi) - sb->s_bdi = NULL; + sb->s_bdi = &default_backing_dev_info; } spin_unlock(&sb_lock); }