From patchwork Fri Apr 17 15:08:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Brian Foster X-Patchwork-Id: 11495377 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 134811392 for ; Fri, 17 Apr 2020 15:09:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFF532223D for ; Fri, 17 Apr 2020 15:09:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Oi3ZV8Ri" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728193AbgDQPJI (ORCPT ); Fri, 17 Apr 2020 11:09:08 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:54979 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728858AbgDQPJG (ORCPT ); Fri, 17 Apr 2020 11:09:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587136144; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5wdHauiDbb2jHLjxtcDVlN4iLnrrzaREoLO8WLv72kc=; b=Oi3ZV8RirMpZeBbl/04uTj0Y2NPgtGV4kyfVeSad3ic272p6fdwIlWpSTWAVuVJpxoEfC5 8yRAHu/xSvyqjyMjiEhYK1V5ifkj2LHW0PW8lV4zWKhVyvq8GAjp5ybXnsj1J3aRpZ8/Ma 7W/DrBi4kV93gbp8nW/PpzEmbVrolzk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-296-OM_gzf75NWqSJEDzBUpq-g-1; Fri, 17 Apr 2020 11:09:01 -0400 X-MC-Unique: OM_gzf75NWqSJEDzBUpq-g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8F65C8017FE for ; Fri, 17 Apr 2020 15:09:00 +0000 (UTC) Received: from bfoster.bos.redhat.com (dhcp-41-2.bos.redhat.com [10.18.41.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id 499A360BE0 for ; Fri, 17 Apr 2020 15:09:00 +0000 (UTC) From: Brian Foster To: linux-xfs@vger.kernel.org Subject: [PATCH 01/12] xfs: refactor failed buffer resubmission into xfsaild Date: Fri, 17 Apr 2020 11:08:48 -0400 Message-Id: <20200417150859.14734-2-bfoster@redhat.com> In-Reply-To: <20200417150859.14734-1-bfoster@redhat.com> References: <20200417150859.14734-1-bfoster@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Flush locked log items whose underlying buffers fail metadata writeback are tagged with a special flag to indicate that the flush lock is already held. This is currently implemented in the type specific ->iop_push() callback, but the processing required for such items is not type specific because we're only doing basic state management on the underlying buffer. Factor the failed log item handling out of the inode and dquot ->iop_push() callbacks and open code the buffer resubmit helper into a single helper called from xfsaild_push_item(). This provides a generic mechanism for handling failed metadata buffer writeback with a bit less code. Signed-off-by: Brian Foster Reviewed-by: Allison Collins --- fs/xfs/xfs_buf_item.c | 39 --------------------------------------- fs/xfs/xfs_buf_item.h | 2 -- fs/xfs/xfs_dquot_item.c | 15 --------------- fs/xfs/xfs_inode_item.c | 15 --------------- fs/xfs/xfs_trans_ail.c | 41 +++++++++++++++++++++++++++++++++++++++++ 5 files changed, 41 insertions(+), 71 deletions(-) diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index 1545657c3ca0..8796adde2d12 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -1248,42 +1248,3 @@ xfs_buf_iodone( xfs_trans_ail_delete(ailp, lip, SHUTDOWN_CORRUPT_INCORE); xfs_buf_item_free(BUF_ITEM(lip)); } - -/* - * Requeue a failed buffer for writeback. - * - * We clear the log item failed state here as well, but we have to be careful - * about reference counts because the only active reference counts on the buffer - * may be the failed log items. Hence if we clear the log item failed state - * before queuing the buffer for IO we can release all active references to - * the buffer and free it, leading to use after free problems in - * xfs_buf_delwri_queue. It makes no difference to the buffer or log items which - * order we process them in - the buffer is locked, and we own the buffer list - * so nothing on them is going to change while we are performing this action. - * - * Hence we can safely queue the buffer for IO before we clear the failed log - * item state, therefore always having an active reference to the buffer and - * avoiding the transient zero-reference state that leads to use-after-free. - * - * Return true if the buffer was added to the buffer list, false if it was - * already on the buffer list. - */ -bool -xfs_buf_resubmit_failed_buffers( - struct xfs_buf *bp, - struct list_head *buffer_list) -{ - struct xfs_log_item *lip; - bool ret; - - ret = xfs_buf_delwri_queue(bp, buffer_list); - - /* - * XFS_LI_FAILED set/clear is protected by ail_lock, caller of this - * function already have it acquired - */ - list_for_each_entry(lip, &bp->b_li_list, li_bio_list) - xfs_clear_li_failed(lip); - - return ret; -} diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h index 30114b510332..c9c57e2da932 100644 --- a/fs/xfs/xfs_buf_item.h +++ b/fs/xfs/xfs_buf_item.h @@ -59,8 +59,6 @@ void xfs_buf_attach_iodone(struct xfs_buf *, struct xfs_log_item *); void xfs_buf_iodone_callbacks(struct xfs_buf *); void xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *); -bool xfs_buf_resubmit_failed_buffers(struct xfs_buf *, - struct list_head *); bool xfs_buf_log_check_iovec(struct xfs_log_iovec *iovec); extern kmem_zone_t *xfs_buf_item_zone; diff --git a/fs/xfs/xfs_dquot_item.c b/fs/xfs/xfs_dquot_item.c index baad1748d0d1..5a7808299a32 100644 --- a/fs/xfs/xfs_dquot_item.c +++ b/fs/xfs/xfs_dquot_item.c @@ -145,21 +145,6 @@ xfs_qm_dquot_logitem_push( if (atomic_read(&dqp->q_pincount) > 0) return XFS_ITEM_PINNED; - /* - * The buffer containing this item failed to be written back - * previously. Resubmit the buffer for IO - */ - if (test_bit(XFS_LI_FAILED, &lip->li_flags)) { - if (!xfs_buf_trylock(bp)) - return XFS_ITEM_LOCKED; - - if (!xfs_buf_resubmit_failed_buffers(bp, buffer_list)) - rval = XFS_ITEM_FLUSHING; - - xfs_buf_unlock(bp); - return rval; - } - if (!xfs_dqlock_nowait(dqp)) return XFS_ITEM_LOCKED; diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c index f779cca2346f..1d4d256a2e96 100644 --- a/fs/xfs/xfs_inode_item.c +++ b/fs/xfs/xfs_inode_item.c @@ -497,21 +497,6 @@ xfs_inode_item_push( if (xfs_ipincount(ip) > 0) return XFS_ITEM_PINNED; - /* - * The buffer containing this item failed to be written back - * previously. Resubmit the buffer for IO. - */ - if (test_bit(XFS_LI_FAILED, &lip->li_flags)) { - if (!xfs_buf_trylock(bp)) - return XFS_ITEM_LOCKED; - - if (!xfs_buf_resubmit_failed_buffers(bp, buffer_list)) - rval = XFS_ITEM_FLUSHING; - - xfs_buf_unlock(bp); - return rval; - } - if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) return XFS_ITEM_LOCKED; diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 564253550b75..0c709651a2c6 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -345,6 +345,45 @@ xfs_ail_delete( xfs_trans_ail_cursor_clear(ailp, lip); } +/* + * Requeue a failed buffer for writeback. + * + * We clear the log item failed state here as well, but we have to be careful + * about reference counts because the only active reference counts on the buffer + * may be the failed log items. Hence if we clear the log item failed state + * before queuing the buffer for IO we can release all active references to + * the buffer and free it, leading to use after free problems in + * xfs_buf_delwri_queue. It makes no difference to the buffer or log items which + * order we process them in - the buffer is locked, and we own the buffer list + * so nothing on them is going to change while we are performing this action. + * + * Hence we can safely queue the buffer for IO before we clear the failed log + * item state, therefore always having an active reference to the buffer and + * avoiding the transient zero-reference state that leads to use-after-free. + */ +static inline int +xfsaild_push_failed( + struct xfs_log_item *lip, + struct list_head *buffer_list) +{ + struct xfs_buf *bp = lip->li_buf; + + if (!xfs_buf_trylock(bp)) + return XFS_ITEM_LOCKED; + + if (!xfs_buf_delwri_queue(bp, buffer_list)) { + xfs_buf_unlock(bp); + return XFS_ITEM_FLUSHING; + } + + /* protected by ail_lock */ + list_for_each_entry(lip, &bp->b_li_list, li_bio_list) + xfs_clear_li_failed(lip); + + xfs_buf_unlock(bp); + return XFS_ITEM_SUCCESS; +} + static inline uint xfsaild_push_item( struct xfs_ail *ailp, @@ -365,6 +404,8 @@ xfsaild_push_item( */ if (!lip->li_ops->iop_push) return XFS_ITEM_PINNED; + if (test_bit(XFS_LI_FAILED, &lip->li_flags)) + return xfsaild_push_failed(lip, &ailp->ail_buf_list); return lip->li_ops->iop_push(lip, &ailp->ail_buf_list); }