Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.netapp.com ([216.240.18.38]:50733 "EHLO mx1.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753631Ab3ADSPL (ORCPT ); Fri, 4 Jan 2013 13:15:11 -0500 From: Trond Myklebust To: linux-nfs@vger.kernel.org Cc: Weston Andros Adamson , Tejun Heo , Bruce Fields Subject: [PATCH 2/3] NFS: Ensure that we free the rpc_task after read and write cleanups are done Date: Fri, 4 Jan 2013 13:15:01 -0500 Message-Id: <1357323302-12944-2-git-send-email-Trond.Myklebust@netapp.com> In-Reply-To: <1357323302-12944-1-git-send-email-Trond.Myklebust@netapp.com> References: <0EC8763B847DB24D9ADF5EBD9CD7B419125A16A9@SACEXCMBX02-PRD.hq.netapp.com> <1357323302-12944-1-git-send-email-Trond.Myklebust@netapp.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: This patch ensures that we free the rpc_task after the cleanup callbacks are done in order to avoid a deadlock problem that can be triggered if the callback needs to wait for another workqueue item to complete. Signed-off-by: Trond Myklebust Cc: Weston Andros Adamson Cc: Tejun Heo Cc: Bruce Fields Cc: stable@vger.kernel.org [>= 3.5] --- fs/nfs/read.c | 10 +++++++--- fs/nfs/write.c | 10 +++++++--- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/fs/nfs/read.c b/fs/nfs/read.c index b6bdb18..a5e5d98 100644 --- a/fs/nfs/read.c +++ b/fs/nfs/read.c @@ -91,12 +91,16 @@ void nfs_readdata_release(struct nfs_read_data *rdata) put_nfs_open_context(rdata->args.context); if (rdata->pages.pagevec != rdata->pages.page_array) kfree(rdata->pages.pagevec); - if (rdata != &read_header->rpc_data) - kfree(rdata); - else + if (rdata == &read_header->rpc_data) { rdata->header = NULL; + rdata = NULL; + } if (atomic_dec_and_test(&hdr->refcnt)) hdr->completion_ops->completion(hdr); + /* Note: we only free the rpc_task after callbacks are done. + * See the comment in rpc_free_task() for why + */ + kfree(rdata); } EXPORT_SYMBOL_GPL(nfs_readdata_release); diff --git a/fs/nfs/write.c b/fs/nfs/write.c index b673be3..c483cc5 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -126,12 +126,16 @@ void nfs_writedata_release(struct nfs_write_data *wdata) put_nfs_open_context(wdata->args.context); if (wdata->pages.pagevec != wdata->pages.page_array) kfree(wdata->pages.pagevec); - if (wdata != &write_header->rpc_data) - kfree(wdata); - else + if (wdata == &write_header->rpc_data) { wdata->header = NULL; + wdata = NULL; + } if (atomic_dec_and_test(&hdr->refcnt)) hdr->completion_ops->completion(hdr); + /* Note: we only free the rpc_task after callbacks are done. + * See the comment in rpc_free_task() for why + */ + kfree(wdata); } EXPORT_SYMBOL_GPL(nfs_writedata_release); -- 1.7.11.7