Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758607AbcJQIPo (ORCPT ); Mon, 17 Oct 2016 04:15:44 -0400 Received: from mx2.suse.de ([195.135.220.15]:48793 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933730AbcJQINt (ORCPT ); Mon, 17 Oct 2016 04:13:49 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Ashish Samant , Mark Fasheh , Joel Becker , Junxiao Bi , Joseph Qi , Eric Ren , Andrew Morton , Linus Torvalds , Jiri Slaby Subject: [PATCH 3.12 05/84] ocfs2: fix start offset to ocfs2_zero_range_for_truncate() Date: Mon, 17 Oct 2016 09:50:52 +0200 Message-Id: <341ec0a305e2e64d67f346c09445c7328579f120.1476690493.git.jslaby@suse.cz> X-Mailer: git-send-email 2.10.1 In-Reply-To: <2d291fde5f706ac081e8cfc0ebe7e31dd534dfe7.1476690493.git.jslaby@suse.cz> References: <2d291fde5f706ac081e8cfc0ebe7e31dd534dfe7.1476690493.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3702 Lines: 109 From: Ashish Samant 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit d21c353d5e99c56cdd5b5c1183ffbcaf23b8b960 upstream. If we punch a hole on a reflink such that following conditions are met: 1. start offset is on a cluster boundary 2. end offset is not on a cluster boundary 3. (end offset is somewhere in another extent) or (hole range > MAX_CONTIG_BYTES(1MB)), we dont COW the first cluster starting at the start offset. But in this case, we were wrongly passing this cluster to ocfs2_zero_range_for_truncate() to zero out. This will modify the cluster in place and zero it in the source too. Fix this by skipping this cluster in such a scenario. To reproduce: 1. Create a random file of say 10 MB xfs_io -c 'pwrite -b 4k 0 10M' -f 10MBfile 2. Reflink it reflink -f 10MBfile reflnktest 3. Punch a hole at starting at cluster boundary with range greater that 1MB. You can also use a range that will put the end offset in another extent. fallocate -p -o 0 -l 1048615 reflnktest 4. sync 5. Check the first cluster in the source file. (It will be zeroed out). dd if=10MBfile iflag=direct bs= count=1 | hexdump -C Link: http://lkml.kernel.org/r/1470957147-14185-1-git-send-email-ashish.samant@oracle.com Signed-off-by: Ashish Samant Reported-by: Saar Maoz Reviewed-by: Srinivas Eeda Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Joseph Qi Cc: Eric Ren Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Jiri Slaby --- fs/ocfs2/file.c | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-) diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 1c01e723e780..54ba0afacf00 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1495,7 +1495,8 @@ static int ocfs2_zero_partial_clusters(struct inode *inode, u64 start, u64 len) { int ret = 0; - u64 tmpend, end = start + len; + u64 tmpend = 0; + u64 end = start + len; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); unsigned int csize = osb->s_clustersize; handle_t *handle; @@ -1527,18 +1528,31 @@ static int ocfs2_zero_partial_clusters(struct inode *inode, } /* - * We want to get the byte offset of the end of the 1st cluster. + * If start is on a cluster boundary and end is somewhere in another + * cluster, we have not COWed the cluster starting at start, unless + * end is also within the same cluster. So, in this case, we skip this + * first call to ocfs2_zero_range_for_truncate() truncate and move on + * to the next one. */ - tmpend = (u64)osb->s_clustersize + (start & ~(osb->s_clustersize - 1)); - if (tmpend > end) - tmpend = end; + if ((start & (csize - 1)) != 0) { + /* + * We want to get the byte offset of the end of the 1st + * cluster. + */ + tmpend = (u64)osb->s_clustersize + + (start & ~(osb->s_clustersize - 1)); + if (tmpend > end) + tmpend = end; - trace_ocfs2_zero_partial_clusters_range1((unsigned long long)start, - (unsigned long long)tmpend); + trace_ocfs2_zero_partial_clusters_range1( + (unsigned long long)start, + (unsigned long long)tmpend); - ret = ocfs2_zero_range_for_truncate(inode, handle, start, tmpend); - if (ret) - mlog_errno(ret); + ret = ocfs2_zero_range_for_truncate(inode, handle, start, + tmpend); + if (ret) + mlog_errno(ret); + } if (tmpend < end) { /* -- 2.10.1