Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932155AbZFOSAo (ORCPT ); Mon, 15 Jun 2009 14:00:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765071AbZFOR76 (ORCPT ); Mon, 15 Jun 2009 13:59:58 -0400 Received: from cantor2.suse.de ([195.135.220.15]:50050 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765024AbZFOR75 (ORCPT ); Mon, 15 Jun 2009 13:59:57 -0400 From: Jan Kara To: LKML Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, npiggin@suse.de, Jan Kara Subject: [PATCH 07/11] vfs: Unmap underlying metadata of new data buffers only when buffer is mapped Date: Mon, 15 Jun 2009 19:59:54 +0200 Message-Id: <1245088797-29533-8-git-send-email-jack@suse.cz> X-Mailer: git-send-email 1.6.0.2 In-Reply-To: <1245088797-29533-1-git-send-email-jack@suse.cz> References: <1245088797-29533-1-git-send-email-jack@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1961 Lines: 56 When we do delayed allocation of some buffer, we want to signal to VFS that the buffer is new (set buffer_new) so that it properly zeros out everything. But we don't have the buffer mapped yet so we cannot really unmap underlying metadata in this state. Make VFS avoid doing unmapping of metadata when the buffer is not yet mapped. Signed-off-by: Jan Kara --- fs/buffer.c | 12 +++++++----- 1 files changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/buffer.c b/fs/buffer.c index 80e2630..7eb1710 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -1683,8 +1683,9 @@ static int __block_write_full_page(struct inode *inode, struct page *page, if (buffer_new(bh)) { /* blockdev mappings never come here */ clear_buffer_new(bh); - unmap_underlying_metadata(bh->b_bdev, - bh->b_blocknr); + if (buffer_mapped(bh)) + unmap_underlying_metadata(bh->b_bdev, + bh->b_blocknr); } } bh = bh->b_this_page; @@ -1869,8 +1870,9 @@ static int __block_prepare_write(struct inode *inode, struct page *page, if (err) break; if (buffer_new(bh)) { - unmap_underlying_metadata(bh->b_bdev, - bh->b_blocknr); + if (buffer_mapped(bh)) + unmap_underlying_metadata(bh->b_bdev, + bh->b_blocknr); if (PageUptodate(page)) { clear_buffer_new(bh); set_buffer_uptodate(bh); @@ -2683,7 +2685,7 @@ int nobh_write_begin(struct file *file, struct address_space *mapping, goto failed; if (!buffer_mapped(bh)) is_mapped_to_disk = 0; - if (buffer_new(bh)) + if (buffer_new(bh) && buffer_mapped(bh)) unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr); if (PageUptodate(page)) { set_buffer_uptodate(bh); -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/