From patchwork Fri Nov 24 23:47:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Darrick J. Wong" X-Patchwork-Id: 13468248 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C0C082C86B for ; Fri, 24 Nov 2023 23:47:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NY2o3J9n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 456ECC433C8; Fri, 24 Nov 2023 23:47:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700869630; bh=HBA1eE8bA/NoEg+9WJLCkOf30isw2J/hGcyDoU/rfF0=; h=Date:Subject:From:To:Cc:In-Reply-To:References:From; b=NY2o3J9nLLqVVcJBbcPWQxd+b3Wzuiq4ej+/0n6+e+BxOIiWf9Z72aS3H+18pXqU+ Oq/AjCaBEHLhnivMV3K8QnMdPRyKwcog9ME9bIHcwnTmu5/oyFbNjbyoVFUdqFSEJD c2fcTTpj+UbSYSSfH4QLNU35srThIfzWVisDNpYMBoxg5gogbOYzSbhYyNAUhPTUEo eFK8HCj+9QtiWcE+zWReIg9bOGF2+wqfFME1Psvx+yNvo2nJC/k9iEfZ9XSriDDAGV lLi/pqZu/Mu7sHzgrVcZIWukdH0q7qmBcztJjdxwXfeVcOdZ8yYVyvivHJYztH6J5T 3f172J+ESu5jg== Date: Fri, 24 Nov 2023 15:47:09 -0800 Subject: [PATCH 1/7] xfs: don't append work items to logged xfs_defer_pending objects From: "Darrick J. Wong" To: djwong@kernel.org Cc: Dave Chinner , linux-xfs@vger.kernel.org Message-ID: <170086926145.2768790.15414309437495285174.stgit@frogsfrogsfrogs> In-Reply-To: <170086926113.2768790.10021834422326302654.stgit@frogsfrogsfrogs> References: <170086926113.2768790.10021834422326302654.stgit@frogsfrogsfrogs> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Darrick J. Wong When someone tries to add a deferred work item to xfs_defer_add, it will try to attach the work item to the most recently added xfs_defer_pending object attached to the transaction. However, it doesn't check if the pending object has a log intent item attached to it. This is incorrect behavior because we cannot add more work to an object that has already been committed to the ondisk log. Therefore, change the behavior not to append to pending items with a non null dfp_intent. In practice this has not been an issue because the only way xfs_defer_add gets called after log intent items have been committed is from the defer ops ->finish_item functions themselves, and the @dop_pending isolation in xfs_defer_finish_noroll protects the pending items that have already been logged. However, the next patch will add the ability to pause a deferred extent free object during online btree rebuilding, and any new extfree work items need to have their own pending event. While we're at it, hoist the predicate to its own static inline function for readability. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/libxfs/xfs_defer.c | 48 ++++++++++++++++++++++++++++++++++----------- 1 file changed, 36 insertions(+), 12 deletions(-) diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c index f71679ce23b95..6c283b30ea054 100644 --- a/fs/xfs/libxfs/xfs_defer.c +++ b/fs/xfs/libxfs/xfs_defer.c @@ -624,6 +624,40 @@ xfs_defer_cancel( xfs_defer_cancel_list(mp, &tp->t_dfops); } +/* + * Decide if we can add a deferred work item to the last dfops item attached + * to the transaction. + */ +static inline struct xfs_defer_pending * +xfs_defer_try_append( + struct xfs_trans *tp, + enum xfs_defer_ops_type type, + const struct xfs_defer_op_type *ops) +{ + struct xfs_defer_pending *dfp = NULL; + + /* No dfops at all? */ + if (list_empty(&tp->t_dfops)) + return NULL; + + dfp = list_last_entry(&tp->t_dfops, struct xfs_defer_pending, + dfp_list); + + /* Wrong type? */ + if (dfp->dfp_type != type) + return NULL; + + /* Already logged? */ + if (dfp->dfp_intent) + return NULL; + + /* Already full? */ + if (ops->max_items && dfp->dfp_count >= ops->max_items) + return NULL; + + return dfp; +} + /* Add an item for later deferred processing. */ void xfs_defer_add( @@ -637,19 +671,9 @@ xfs_defer_add( ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES); BUILD_BUG_ON(ARRAY_SIZE(defer_op_types) != XFS_DEFER_OPS_TYPE_MAX); - /* - * Add the item to a pending item at the end of the intake list. - * If the last pending item has the same type, reuse it. Else, - * create a new pending item at the end of the intake list. - */ - if (!list_empty(&tp->t_dfops)) { - dfp = list_last_entry(&tp->t_dfops, - struct xfs_defer_pending, dfp_list); - if (dfp->dfp_type != type || - (ops->max_items && dfp->dfp_count >= ops->max_items)) - dfp = NULL; - } + dfp = xfs_defer_try_append(tp, type, ops); if (!dfp) { + /* Create a new pending item at the end of the intake list. */ dfp = kmem_cache_zalloc(xfs_defer_pending_cache, GFP_NOFS | __GFP_NOFAIL); dfp->dfp_type = type;