glusterfs.git/libglusterfs/src, branch exp

cluster/ec: Fix lk-owner set race in ec_unlock

2016-12-13T15:24:51+00:00

Problem:
Rename does two locks. There is a case where when it tries to unlock it sends
xattrop of the directory with new version, callback of these two xattrops can
be picked up by two separate epoll threads. Both of them will try to set the
lk-owner for unlock in parallel on the same frame so one of these unlocks will
fail because the lk-owner doesn't match.

Fix:
Specify the lk-owner which will be set on inodelk frame which will not be over
written by any other thread/operation.

BUG: 1402710
Change-Id: I666ffc931440dc5253d72df666efe0ef1d73f99a
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/16074
Reviewed-by: Xavier Hernandez 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

refcount: return pointer to the structure instead of a counter

2016-12-11T08:47:05+00:00

There are no real users of the counter. It was thought of a handy tool
to track and debug refcounting, but it is not used at all. Some parts of
the code would benefit from a pointer getting returned instead.

BUG: 1399780
Change-Id: I97e52c48420fed61be942ea27ff4849b803eed12
Signed-off-by: Niels de Vos 
Reviewed-on: http://review.gluster.org/15971
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Xavier Hernandez 
Reviewed-by: Kaleb KEITHLEY

syncop: fix conditional wait bug in parallel dir scan

2016-12-09T10:24:21+00:00

Problem:
The issue as seen by the user is detailed in the BZ but what is
happening is if the no. of items in the wait queue == max-qlen,
syncop_mt_dir_scan() does a pthread_cond_wait until the launched
synctask workers dequeue the queue. But if for some reason the worker
fails, the queue is never emptied due to which further invocations of
syncop_mt_dir_scan() are blocked forever.

Fix: Made some changes to _dir_scan_job_fn

- If a worker encounters error while processing an entry, notify the
  readdir loop in syncop_mt_dir_scan() of the error but continue to process
  other entries in the queue, decrementing the qlen as and when we dequeue
  elements, and ending only when the queue is empty.

- If the readdir loop in syncop_mt_dir_scan() gets an error form the
  worker, stop the readdir+queueing of further entries.

Change-Id: I39ce073e01a68c7ff18a0e9227389245a6f75b88
BUG: 1402841
Signed-off-by: Ravishankar N 
Reviewed-on: http://review.gluster.org/16073
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Pranith Kumar Karampuri

glusterd/geo-rep: Fix glusterd crash

2016-12-08T09:12:07+00:00

Problem:
glusterd crashes when geo-rep mountbroker setup is
created if the slave user length is more than
8 characters.

Cause:
_POSIX_LOGIN_NAME_MAX is used which is 9 including
NULL byte.

Analysis:
While the man page says it sufficient for portability, but
acutally it's not. Linux allows the creation of username
upto 32 characters by default where the max length is 256.
And NetBSD's max is 17.

Linux:
  #getconf LOGIN_NAME_MAX
   256
NetBSD:
  #getconf LOGIN_NAME_MAX
   17

Fix:
Use LOGIN_NAME_MAX instead of _POSIX_LOGIN_NAME_MAX

Change-Id: I26b7230433ecbbed6e6914ed39221a478c0266a8
BUG: 1368138
Signed-off-by: Kotresh HR 
Reviewed-on: http://review.gluster.org/16053
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Aravinda VK 
Reviewed-by: Atin Mukherjee

dht/md-cache: Filter invalidate if the file is made a linkto file

2016-12-02T10:46:58+00:00

Upcall as a part of setattr, sends an invalidation and the
invalidation carries the resulting stat value. When a file
is converted to linkto files, even then an invalidation
is set and as a result the mountpoint shows the sticky
bit in the stat of the file.
eg: ---------T. 945 root root 0 Nov  8 10:14 hardlink.999

Fix:
When dht recieves a notification of sticky bit change, it updates
the flag, to indicate md-cache to send the subsequent lookup.

Change-Id: Ic2fd7a5b196db0754f9b97072e644e6bf69da606
BUG: 1392713
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/15789
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Niels de Vos 
CentOS-regression: Gluster Build System 
Reviewed-by: Susant Palai 
Reviewed-by: Rajesh Joseph

cluster/tier: fix op-version for tier-query-limit

2016-12-02T04:06:59+00:00

Correct the op-version for tier-query-limit option from 3.9.0 to 3.9.1

Change-Id: I3a52a94c2708a97c18377e945d559a51d8025c41
BUG: 1366648
Signed-off-by: Milind Changire 
Reviewed-on: http://review.gluster.org/15990
Reviewed-by: Dan Lambright 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Atin Mukherjee

libglusterfs: Fix a read hang

2016-11-29T03:59:08+00:00

Issue:
=====
In certain cases, there was no unwind of read
from read-ahead xlator, thus resulting in hang.

RCA:
====
In certain cases, ioc_readv() issues STACK_WIND_TAIL() instead
of STACK_WIND(). One such case is when inode_ctx for that file
is not present (can happen if readdirp was called, and populates
md-cache and serves all the lookups from cache).

Consider the following graph:
...
io-cache (parent)
   |
readdir-ahead
   |
read-ahead
...

Below is the code snippet of ioc_readv calling STACK_WIND_TAIL:
ioc_readv()
{
...
 if (!inode_ctx)
   STACK_WIND_TAIL (frame, FIRST_CHILD (frame->this),
                    FIRST_CHILD (frame->this)->fops->readv, fd,
                    size, offset, flags, xdata);
   /* Ideally, this stack_wind should wind to readdir-ahead:readv()
      but it winds to read-ahead:readv(). See below for
      explaination.
    */
...
}

STACK_WIND_TAIL (frame, obj, fn, ...)
{
  frame->this = obj;
  /* for the above mentioned graph, frame->this will be readdir-ahead
   * frame->this = FIRST_CHILD (frame->this) i.e. readdir-ahead, which
   * is as expected
   */
  ...
  THIS = obj;
  /* THIS will be read-ahead instead of readdir-ahead!, as obj expands
   * to "FIRST_CHILD (frame->this)" and frame->this was pointing
   * to readdir-ahead in the previous statement.
   */
  ...
  fn (frame, obj, params);
  /* fn will call read-ahead:readv() instead of readdir-ahead:readv()!
   * as fn expands to "FIRST_CHILD (frame->this)->fops->readv" and
   * frame->this was pointing ro readdir-ahead in the first statement
   */
  ...
}

Thus, the readdir-ahead's readv() implementation will be skipped, and
ra_readv() will be called with frame->this = "readdir-ahead" and
this = "read-ahead". This can lead to corruption / hang / other problems.
But in this perticular case, when 'frame->this' and 'this' passed
to ra_readv() doesn't match, it causes ra_readv() to call ra_readv()
again!. Thus the logic of read-ahead readv() falls apart and leads to
hang.

Solution:
=========
Modify STACK_WIND_TAIL() as:
STACK_WIND_TAIL (frame, obj, fn, ...)
{
  next_xl = obj /* resolve obj as the variables passed in obj macro
                   can be overwritten in the further instrucions */
  next_xl_fn = fn /* resolve fn and store in a tmp variable, before
                     modifying any variables */
  frame->this = next_xl;
  ...
  THIS = next_xl;
  ...
  next_xl_fn (frame, next_xl, params);
  ...
}

As a part of http://review.gluster.org/15901/ the caller io-cache
was fixed.

BUG: 1388292
Change-Id: Ie662ac8f18fa16909376f1e59387bc5b886bd0f9
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/15923
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Rajesh Joseph 
CentOS-regression: Gluster Build System 
Reviewed-by: Raghavendra G

libglusterfs:Now mempool is added to ctx pool list under a lock

2016-11-22T12:45:34+00:00

mempool is added to ctx pool list without any lock. This can cause undefined
behaviour in case of multithreaded environment.

Fix: modify the list only under ctx->lock

Change-Id: I7bdbb3db48a899bb0e41427e149b13c0facaedba
Signed-off-by: Rajesh Joseph 
BUG: 1394719
Reviewed-on: http://review.gluster.org/15842
NetBSD-regression: NetBSD Build System 
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Raghavendra Talur 
Reviewed-by: Shyamsundar Ranganathan 
Reviewed-by: Poornima G 
Reviewed-by: Niels de Vos

afr,dht,ec: Replace GF_EVENT_CHILD_MODIFIED with event SOME_DESCENDENT_DOWN/UP

2016-11-21T09:32:05+00:00

Currently these are few events related to child_up/down:
GF_EVENT_CHILD_UP :  Issued when any of the protocol client
connects.
GF_EVENT_CHILD_MODIFIED : Issued by afr/dht/ec
GF_EVENT_CHILD_DOWN : Issued when any of the protocol client
disconnects.
These events get modified at the dht/afr/ec layers. Here is a
brief on the same.

DHT:
- All the subvolumes reported once, and atleast one child came
  up, then GF_EVENT_CHILD_UP is issued
- connect GF_EVENT_CHILD_UP is issued
- disconnect GF_EVENT_CHILD_MODIFIED is issued
- All the subvolumes disconnected, GF_EVENT_CHILD_DOWN is issued

AFR:
- First subvolume came up, then GF_EVENT_CHILD_UP is issued
- Subsequent subvolumes coming up, results in GF_EVENT_CHILD_MODIFIED
- Any of the subvolumes go down, then GF_EVENT_SOME_CHILD_DOWN is issued
- Last up subvolume goes down, then GF_EVENT_CHILD_DOWN is issued

Until the patch [1] introduced GF_EVENT_SOME_CHILD_UP,
GF_EVENT_CHILD_MODIFIED was issued by afr/dht when any of the subvolumes
go up or down.

Now with md-cache changes, there is a necessity to differentiate between
child up and down. Hence, introducing GF_EVENT_SOME_DESCENDENT_DOWN/UP and
getting rid of GF_EVENT_CHILD_MODIFIED.

[1] http://review.gluster.org/12573

Change-Id: I704140b6598f7ec705493251d2dbc4191c965a58
BUG: 1396038
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/15764
CentOS-regression: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Smoke: Gluster Build System 
Reviewed-by: N Balachandran 
Reviewed-by: Pranith Kumar Karampuri 
Reviewed-by: Rajesh Joseph

events: Add FMT_WARN for gf_event

2016-11-18T09:56:39+00:00

Raghavendra G found that posix is trying to print %s
but passing an int when HEALTH_CHECK fails in posix.
These are the kind of bugs that should be caught
at compilation itself.
Also fixed the problematic gf_event() callers.

BUG: 1386097
Change-Id: Id7bd6d9a9690237cec3ca1aefa2aac085e8a1270
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/15671
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Atin Mukherjee 
CentOS-regression: Gluster Build System