Bug 1388318

+++ This bug was initially created as a clone of Bug #1378778 +++

Description of problem:
Same as summary.

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
1.
2.
3.

Actual results:


Expected results:


Additional info:

--- Additional comment from Krutika Dhananjay on 2016-09-23 06:58:22 EDT ---

All is not well in the compound fops world. I wrote and ran the following simple test on master:

<script>

  0 #!/bin/bash                                                    
  1 . $(dirname $0)/../../include.rc
  2 . $(dirname $0)/../../volume.rc
  3
  4 cleanup
  5
  6 TEST glusterd
  7 TEST pidof glusterd
  8 TEST $CLI volume create $V0 replica 3 $H0:$B0/${V0}{0,1,2}
  9 TEST $CLI volume start $V0
 10 TEST $GFS --volfile-id=$V0 --volfile-server=$H0 $M0
 11
 12 TEST dd if=/dev/urandom of=$M0/file bs=1024 count=10 2>/dev/null
 13 md5sum_file=$(md5sum $M0/file | awk '{print $1}')
 14
 15 TEST $CLI volume set $V0 cluster.use-compound-fops on
 16
 17 TEST dd if=$M0/file of=$M0/file-copy bs=1024 count=10 2>/dev/null
 18
 19 EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0
 20 TEST $GFS --volfile-id=$V0 --volfile-server=$H0 $M0
 21
 22 EXPECT "$md5sum_file" echo `md5sum $M0/file-copy | awk '{print $1}'`
 23
 24 EXPECT_WITHIN $UMOUNT_TIMEOUT "Y" force_umount $M0
 25 TEST $CLI volume stop $V0
 26 TEST $CLI volume delete $V0
 27
 28 cleanup

</script>


The md5sum comparison at line 22 fails. The script runs fine when I "comment out" line 15, implying the bug is in compound fops.

Will post my findings after the issue is RC'd.

-Krutika

--- Additional comment from Worker Ant on 2016-10-17 06:21:35 EDT ---

REVIEW: http://review.gluster.org/15654 (compound fops: Fix file corruption issue) posted (#1) for review on master by Krutika Dhananjay (kdhananj)

--- Additional comment from Worker Ant on 2016-10-17 08:59:33 EDT ---

REVIEW: http://review.gluster.org/15654 (compound fops: Fix file corruption issue) posted (#2) for review on master by Krutika Dhananjay (kdhananj)

--- Additional comment from Worker Ant on 2016-10-20 02:58:12 EDT ---

REVIEW: http://review.gluster.org/15654 (compound fops: Fix file corruption issue) posted (#3) for review on master by Krutika Dhananjay (kdhananj)

--- Additional comment from Worker Ant on 2016-10-20 06:55:36 EDT ---

REVIEW: http://review.gluster.org/15654 (compound fops: Fix file corruption issue) posted (#4) for review on master by Krutika Dhananjay (kdhananj)

--- Additional comment from Worker Ant on 2016-10-24 02:20:45 EDT ---

REVIEW: http://review.gluster.org/15654 (compound fops: Fix file corruption issue) posted (#5) for review on master by Krutika Dhananjay (kdhananj)

--- Additional comment from Worker Ant on 2016-10-24 05:25:59 EDT ---

REVIEW: http://review.gluster.org/15654 (compound fops: Fix file corruption issue) posted (#6) for review on master by Krutika Dhananjay (kdhananj)

--- Additional comment from Worker Ant on 2016-10-24 10:11:12 EDT ---

COMMIT: http://review.gluster.org/15654 committed in master by Atin Mukherjee (amukherj) 
------
commit 41dc5ee07ffba6d17459757abf13fae9f174e6b6
Author: Krutika Dhananjay <kdhananj>
Date:   Mon Oct 17 15:13:28 2016 +0530

    compound fops: Fix file corruption issue
    
    1. Address of a local variable @args is copied into state->req
    in server3_3_compound (). But even after the function has gone out of
    scope, in server_compound_resume () this pointer is accessed and
    dereferenced. This patch fixes that.
    
    2. Compound fops, by virtue of NOT having a vector sizer (like the one
    writev has), ends up having both the header and the data (in case one of
    its member fops is WRITEV) in the same hdr_iobuf. This buffer was not
    being preserved through the lifetime of the compound fop, causing it to
    be overwritten by a parallel write fop, even when the writev associated
    with the currently executing compound fop is yet to hit the desk, thereby
    corrupting the file's data. This is fixed by associating the hdr_iobuf with
    the iobref so its memory remains valid through the lifetime of the fop.
    
    3. Also fixed a use-after-free bug in protocol/client in compound fops cbk,
    missed by Linux but caught by NetBSD.
    
    Finally, big thanks to Pranith Kumar K and Raghavendra Gowdappa for their
    help in debugging this file corruption issue.
    
    Change-Id: I6d5c04f400ecb687c9403a17a12683a96c2bf122
    BUG: 1378778
    Signed-off-by: Krutika Dhananjay <kdhananj>
    Reviewed-on: http://review.gluster.org/15654
    NetBSD-regression: NetBSD Build System <jenkins.org>
    Reviewed-by: Raghavendra G <rgowdapp>
    Smoke: Gluster Build System <jenkins.org>
    CentOS-regression: Gluster Build System <jenkins.org>