From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: linux-xfs-owner@vger.kernel.org Received: from mail.kernel.org ([198.145.29.99]:43286 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727391AbfAaSJe (ORCPT ); Thu, 31 Jan 2019 13:09:34 -0500 From: Luis Chamberlain Subject: [PATCH 09/10] xfs: fix PAGE_MASK usage in xfs_free_file_space Date: Thu, 31 Jan 2019 10:09:18 -0800 Message-Id: <20190131180919.2500-10-mcgrof@kernel.org> In-Reply-To: <20190131180919.2500-1-mcgrof@kernel.org> References: <20190131180919.2500-1-mcgrof@kernel.org> Sender: linux-xfs-owner@vger.kernel.org List-ID: To: linux-xfs@vger.kernel.org, gregkh@linuxfoundation.org, Alexander.Levin@microsoft.com Cc: amir73il@gmail.com, hch@infradead.org, "Darrick J. Wong" , Luis Chamberlain From: "Darrick J. Wong" In commit e53c4b598, I *tried* to teach xfs to force writeback when we fzero/fpunch right up to EOF so that if EOF is in the middle of a page, the post-EOF part of the page gets zeroed before we return to userspace. Unfortunately, I missed the part where PAGE_MASK is ~(PAGE_SIZE - 1), which means that we totally fail to zero if we're fpunching and EOF is within the first page. Worse yet, the same PAGE_MASK thinko plagues the filemap_write_and_wait_range call, so we'd initiate writeback of the entire file, which (mostly) masked the thinko. Drop the tricky PAGE_MASK and replace it with correct usage of PAGE_SIZE and the proper rounding macros. Fixes: e53c4b598 ("xfs: ensure post-EOF zeroing happens after zeroing part of a file") Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Luis Chamberlain --- fs/xfs/xfs_bmap_util.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 9d1e5c3a661e..211b06e4702e 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1175,9 +1175,9 @@ xfs_free_file_space( * page could be mmap'd and iomap_zero_range doesn't do that for us. * Writeback of the eof page will do this, albeit clumsily. */ - if (offset + len >= XFS_ISIZE(ip) && ((offset + len) & PAGE_MASK)) { + if (offset + len >= XFS_ISIZE(ip) && offset_in_page(offset + len) > 0) { error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, - (offset + len) & ~PAGE_MASK, LLONG_MAX); + round_down(offset + len, PAGE_SIZE), LLONG_MAX); } return error; -- 2.18.0