[Gluster-devel] Modifying GlusterFS to cope with C99 inline semantics

[Jeff Darcy]

> > My opinion: don't try to second guess the compiler/optimizer; stop using
> > inline. Full Stop.
> 
> To this end, I've submitted a patch which removes all instances in .c
> files.
> 
>     http://review.gluster.org/#/c/11769/


Regression tests blew up in snapshot code.  It's really hard to see how
this is related to anything in the patch itself, especially because only
one of the un-inlined functions was in snapshot code.  Here's a partial
backtrace:

#0  0x00007fe845d4ce2c in vfprintf () from /d/crap/lib64/libc.so.6
#1  0x00007fe845d74752 in vsnprintf () from /d/crap/lib64/libc.so.6
#2  0x00007fe845d54223 in snprintf () from /d/crap/lib64/libc.so.6
#3  0x00007fe83c62af79 in glusterd_volume_stop_glusterfs (volinfo=0x1f844b0,
    brickinfo=0x1f8e2b0, del_brick=_gf_false)
    at /home/jenkins/root/workspace/rackspace-regression-2GB/xlators/mgmt/glusterd/src/glusterd-utils.c:1757
#4  0x00007fe83c637e15 in glusterd_brick_stop (volinfo=0x1f844b0,
    brickinfo=0x1f8e2b0, del_brick=_gf_false)
    at /home/jenkins/root/workspace/rackspace-regression-2GB/xlators/mgmt/glusterd/src/glusterd-utils.c:5443
#5  0x00007fe83c6c286c in glusterd_snap_volume_remove (rsp_dict=0x7fe82800182c,
    snap_vol=0x1f844b0, remove_lvm=_gf_false, force=_gf_false)
    at /home/jenkins/root/workspace/rackspace-regression-2GB/xlators/mgmt/glusterd/src/glusterd-snapshot.c:2897
#6  0x00007fe83c6c2e17 in glusterd_snap_remove (rsp_dict=0x7fe82800182c,
    snap=0x1f7c1d0, remove_lvm=_gf_false, force=_gf_false)
    at /home/jenkins/root/workspace/rackspace-regression-2GB/xlators/mgmt/glusterd/src/glusterd-snapshot.c:3005
#7  0x00007fe83c6eee54 in glusterd_compare_and_update_snap (
    peer_data=0x7fe828005acc, snap_count=2, peername=0x7fe828003100 "127.1.1.1",
    peerid=0x7fe8280059b0 "\270\300\262u\233+ at Q\264U\325\177\367\261", <incomplete sequence \352\224>)
    at /home/jenkins/root/workspace/rackspace-regression-2GB/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c:1849
#8  0x00007fe83c6ef11b in glusterd_compare_friend_snapshots (
    peer_data=0x7fe828005acc, peername=0x7fe828003100 "127.1.1.1",
    peerid=0x7fe8280059b0 "\270\300\262u\233+ at Q\264U\325\177\367\261", <incomplete sequence \352\224>)
    at /home/jenkins/root/workspace/rackspace-regression-2GB/xlators/mgmt/glusterd/src/glusterd-snapshot-utils.c:1904

Based on how variables are set in frame 7, it looks like we must have
taken the "goto remove_my_data" path at line 1776, but *snap hasn't
really been initialized to a sufficient degree - hence the crash.

(gdb) p *snap
$1 = {lock = -1379869184, volumes = {next = 0x1f1ac6000, prev = 0xc100},
  snap_list = {next = 0x15800, prev = 0x1f7c1d000},
  snapname = "\000\336\300\255\336\000\000\000\000`\254\361\001\000\000\000\000\301\000\000\000\000\000\000\000X\001\000\000\000\000\000\000\320\301\367\001\000\000\000\000\336\300\255\336\000\000\000\000`\254\361\001\000\000\000\000\301\000\000\000\000\000\000\000X\001\000\000\000\000\000\000\320\301\367\001\000\000\000\000\336\300\255\336\000\000\000\000`\254\361\001\000\000\000\000\301\000\000\000\000\000\000\000X\001\000\000\000\000\000\000\320\301\367\001\000\000\000\000\336\300\255\336\000\000\000\000`\254\361\001\000\000\000\000\301\000\000\000\000\000\000\000X\001\000\000\000\000\000\000\320\301\367\001\000\000\000\000\336\300\255\336\000\000\000\000`\254\361\001\000\000\000\000\301\000\000\000\000\000\000\000X\001\000\000\000\000\000\000\320\301\367\001\000\000\000\000"...,
  snap_id = "\000\000\301\000\000\000\000\000\000\000X\001\000\000\000",
  description = 0x1f7c1d000 <error: Cannot access memory at address 0x1f7c1d000>,
  time_stamp = -256, snap_restored = (_gf_true | unknown: 4294967294),
  snap_status = 4294967295, shandle = 0xffffffffffffffff}

Were these code paths ever even tested?  I'm going to move on to
other things.  Perhaps somebody who knows the snapshot code could
figure out how it strangled itself this time.