Return-Path: linux-nfs-owner@vger.kernel.org Received: from casper.infradead.org ([85.118.1.10]:45775 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754072AbaHGHVh (ORCPT ); Thu, 7 Aug 2014 03:21:37 -0400 From: Christoph Hellwig To: Trond Myklebust Cc: linux-nfs@vger.kernel.org Subject: [PATCH 08/17] pnfs/blocklayout: reject pnfs blocksize larger than page size Date: Thu, 7 Aug 2014 09:23:40 +0200 Message-Id: <1407396229-4785-9-git-send-email-hch@lst.de> In-Reply-To: <1407396229-4785-1-git-send-email-hch@lst.de> References: <1407396229-4785-1-git-send-email-hch@lst.de> Sender: linux-nfs-owner@vger.kernel.org List-ID: The Linux VM subsystem can't support block sizes larger than page size for block based filesystems very well. While this can be hacked around to some extent for simple filesystems the read-modify-write cycles required for pnfs block invalid extents are extremly deadlock prone when operating on multiple pages. Reject this case early on instead of pretending to support it (badly). Signed-off-by: Christoph Hellwig --- fs/nfs/blocklayout/blocklayout.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index cbb1797..6c1a421 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -1115,6 +1115,12 @@ bl_set_layoutdriver(struct nfs_server *server, const struct nfs_fh *fh) dprintk("%s Server did not return blksize\n", __func__); return -EINVAL; } + if (server->pnfs_blksize > PAGE_SIZE) { + printk(KERN_ERR "%s: pNFS blksize %d not supported.\n", + __func__, server->pnfs_blksize); + return -EINVAL; + } + b_mt_id = kzalloc(sizeof(struct block_mount_id), GFP_NOFS); if (!b_mt_id) { status = -ENOMEM; -- 1.9.1