From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 7FBA67F6A for ; Tue, 15 Jul 2014 10:08:16 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id 745868F8081 for ; Tue, 15 Jul 2014 08:08:16 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id i1ZwzfLRVdXSVKHW (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Tue, 15 Jul 2014 08:08:12 -0700 (PDT) From: Brian Foster Subject: [PATCH] xfs: fix rounding error of fiemap length parameter Date: Tue, 15 Jul 2014 11:08:06 -0400 Message-Id: <1405436886-61287-1-git-send-email-bfoster@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Cc: Chandan Rajendra The offset and length parameters are converted from bytes to basic blocks by xfs_vn_fiemap(). The BTOBB() converter rounds the value up to the nearest basic block. This leads to unexpected behavior when unaligned offsets are provided to FIEMAP. Fix the conversions of byte values to block values to cover the provided offsets. Round down the start offset to the nearest basic block. Calculate the end offset based on the provided values, round up and calculate length based on the start block offset. Signed-off-by: Brian Foster Reported-by: Chandan Rajendra --- Here's another pass at this. I think this is consistent with what ext4 does... Brian fs/xfs/xfs_iops.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c index d75621a..7212949 100644 --- a/fs/xfs/xfs_iops.c +++ b/fs/xfs/xfs_iops.c @@ -1055,12 +1055,12 @@ xfs_vn_fiemap( return error; /* Set up bmap header for xfs internal routine */ - bm.bmv_offset = BTOBB(start); + bm.bmv_offset = BTOBBT(start); /* Special case for whole file */ if (length == FIEMAP_MAX_OFFSET) bm.bmv_length = -1LL; else - bm.bmv_length = BTOBB(length); + bm.bmv_length = BTOBB(start + length) - bm.bmv_offset; /* We add one because in getbmap world count includes the header */ bm.bmv_count = !fieinfo->fi_extents_max ? MAXEXTNUM : -- 1.8.3.1 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs