Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755425Ab3JUJQc (ORCPT ); Mon, 21 Oct 2013 05:16:32 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:39568 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753076Ab3JUIvk (ORCPT ); Mon, 21 Oct 2013 04:51:40 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David Weber" , "Mark Fashen" , "Sunil Mushran" , "Linus Torvalds" , "Joel Becker" , "Jie Liu" Date: Mon, 21 Oct 2013 09:46:28 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 064/149] ocfs2: fix the end cluster offset of FIEMAP In-Reply-To: X-SA-Exim-Connect-IP: 212.20.242.100 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2488 Lines: 69 3.2.52-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Jie Liu commit 28e8be31803b19d0d8f76216cb11b480b8a98bec upstream. Call fiemap ioctl(2) with given start offset as well as an desired mapping range should show extents if possible. However, we somehow figure out the end offset of mapping via 'mapping_end -= cpos' before iterating the extent records which would cause problems if the given fiemap length is too small to a cluster size, e.g, Cluster size 4096: debugfs.ocfs2 1.6.3 Block Size Bits: 12 Cluster Size Bits: 12 The extended fiemap test utility From David: https://gist.github.com/anonymous/6172331 # dd if=/dev/urandom of=/ocfs2/test_file bs=1M count=1000 # ./fiemap /ocfs2/test_file 4096 10 start: 4096, length: 10 File /ocfs2/test_file has 0 extents: # Logical Physical Length Flags ^^^^^ <-- No extent is shown In this case, at ocfs2_fiemap(): cpos == mapping_end == 1. Hence the loop of searching extent records was not executed at all. This patch remove the in question 'mapping_end -= cpos', and loops until the cpos is larger than the mapping_end as usual. # ./fiemap /ocfs2/test_file 4096 10 start: 4096, length: 10 File /ocfs2/test_file has 1 extents: # Logical Physical Length Flags 0: 0000000000000000 0000000056a01000 0000000006a00000 0000 Signed-off-by: Jie Liu Reported-by: David Weber Tested-by: David Weber Cc: Sunil Mushran Cc: Mark Fashen Cc: Joel Becker Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- fs/ocfs2/extent_map.c | 1 - 1 file changed, 1 deletion(-) --- a/fs/ocfs2/extent_map.c +++ b/fs/ocfs2/extent_map.c @@ -782,7 +782,6 @@ int ocfs2_fiemap(struct inode *inode, st cpos = map_start >> osb->s_clustersize_bits; mapping_end = ocfs2_clusters_for_bytes(inode->i_sb, map_start + map_len); - mapping_end -= cpos; is_last = 0; while (cpos < mapping_end && !is_last) { u32 fe_flags; -- 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/