glusterfs.git/xlators/cluster/dht/src/dht-common.c, branch v3.11dev

tier : Tier as a service

2017-01-17T04:49:47+00:00

tierd is implemented by separating from rebalance process.

The commands affected:

1) Attach tier will trigger this process instead of old one
2) tier start and tier start force will also trigger this process.
3) volume status [tier] will show tier daemon as a process instead
of task and normal tier status and tier detach status works.
4) tier stop implemented.
5) detach tier implemented separately along with new detach tier
status
6) volume tier volname status will work using the changes.
7) volume set works

This patch has separated the tier translator from the legacy
DHT rebalance code. It now sends the RPCs from the CLI
to glusterd separate to the DHT rebalance code.
The daemon is now a service, similar to the snapshot daemon,
and can be viewed using the volume status command.

The code for the validation and commit phase are the same
as the earlier tier validation code in DHT rebalance.

The “brickop” phase has been changed so that the status
command can use this framework.

The service management framework is now used.
DHT rebalance does not use this framework.

This service framework takes care of :

*) spawning the daemon, killing it and other such processes.
*) volume set options , which are written on the volfile.
*) restart and reconfigure functions. Restart is to restart
the daemon at two points
        1)after gluster goes down and comes up.
        2) to stop detach tier.
*) reconfigure is used to make immediate volfile changes.
By doing this, we don’t restart the daemon.
it has the code to rewrite the volfile for topological
changes too (which comes into place during add and remove brick).

With this patch the log, pid, and volfile are separated
and put into respective directories.

Change-Id: I3681d0d66894714b55aa02ca2a30ac000362a399
BUG: 1313838
Signed-off-by: hari gowtham 
Reviewed-on: http://review.gluster.org/13365
Smoke: Gluster Build System 
Tested-by: hari gowtham 
CentOS-regression: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Dan Lambright 
Reviewed-by: Atin Mukherjee

dht: At places needed use STACK_WIND_COOKIE

2017-01-09T18:37:02+00:00

Issue:
frame has a void * cookie pointer.
In case of STACK_WIND_COOKIE frame->cookie is assigned
to what is sent by the caller.
In case of STACK_WIND frame->cookie is assigned to point
point to the frame itself.

For ease of coding, at many places, the cookie in the cbk
is used to get the pointer to the next xl. This is
inconsistent when STACK_WIND_TAIL comes into picture.

Eg: dht_setxattr () {
    for (i = 0 ; i < conf->subvolume_cnt ; i++) {
       STACK_WIND (..dht_checking_pathinfo_cbk,
                   conf->subvolumes[i] ..);
    }

    dht_checking_pathinfo_cbk (...void *cookie...) {
        prev = cookie;
        ...
        for (i = 0; i < conf->subvolume_cnt; i++) {
            if (conf->subvolumes[i] == prev->this) {
                 ...
            }
        }
    }

    Consider the below graph:
    dht (parent)
    readdir-ahead  => Doesn't define setxattr and uses STACK_WIND_TAIL
    protocol-client

    With this graph, when dht_checking_pathinfo_cbk is called,
    cookie will have frame pointing to protocol-client.
    i.e. prev->this will be protocol-client. But dht was expecting
    it to be readdir-ahead as it has stored in conf->subvolumes[i]

Solution:
    Hence, as a thumb rule, if cbk is using cookie, then we explicitly
    call STACK_WIND_COOKIE.

Change-Id: I83aea1e24c809c5a91a0db7283e908e125471bd4
BUG: 1401812
Signed-off-by: Poornima G 
Reviewed-on: http://review.gluster.org/16039
Reviewed-by: Raghavendra G 
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System

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

dht/rename : Incase of failure remove linkto file properly

2016-12-01T15:47:34+00:00

Generally linkto file is created using root user. Consider following
case, a user is trying to rename a file which he is not permitted.
So the rename fails with EACESS and when rename tries to cleanup the
linkto file, it fails.

The above issue happens when rename/00.t test executed on nfs-ganesha
clients :
Steps executed in script
* create a file "abc" using root
* rename the file "abc" to "xyz" using a non root user, it fails with EACESS
* delete "abc"
* create directory "abc" using root
* again try ot rename "abc" to "xyz" using non root user, test hungs here
which slowly leds to OOM kill of ganesha process

RCA put forwarded by Du for OOM kill of ganesha
Note that when we hit this bug, we've a scenario of a dentry being
present as:
    * a linkto file on one subvol
    * a directory on rest of subvols

When a lookup happens on the dentry in such a scenario, the control flow
goes into an infinite loop of:

    dht_lookup_everywhere
    dht_lookup_everywhere_cbk
    dht_lookup_unlink_cbk
    dht_lookup_everywhere_done
    dht_lookup_directory (as local->dir_count > 0)
    dht_lookup_dir_cbk (sets to local->need_selfheal = 1 as the entry is a linkto file on one of the subvol)
    dht_lookup_everywhere (as need_selfheal = 1).

This infinite loop can cause increased consumption of memory due to:
1) dht_lookup_directory assigns a new layout to local->layout unconditionally
2)  Most of the functions in this loop do a stack_wind of various fops.

This results in growing of call stack (note that call-stack is destroyed only after lookup response is
received by fuse - which never happens in this case)

Thanks Du for root causing the oom kill and Sushant for suggesting the fix

Change-Id: I1e16bc14aa685542afbd21188426ecb61fd2689d
BUG: 1397052
Signed-off-by: Jiffin Tony Thottan 
Reviewed-on: http://review.gluster.org/15894
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Smoke: Gluster Build System 
Reviewed-by: Raghavendra G

cluster/dht Set layout after mkdir as root

2016-11-21T14:40:15+00:00

DHT does not set the layout for newly created
directories as root. This causes EPERM failures
when a non-root user with insufficient permissions
creates directories.

credit: srangana@redhat.com for RCA

Change-Id: Ia646e41665ce172c43c5f01d2707455e8eb374ed
BUG: 1392772
Signed-off-by: N Balachandran 
Reviewed-on: http://review.gluster.org/15794
Reviewed-by: Susant Palai 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Smoke: Gluster Build System 
Reviewed-by: Raghavendra G 
Reviewed-by: Jeff Darcy

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

cluster/dht: Check for null inode

2016-11-16T03:42:33+00:00

Check for NULL inode before attempting to
set dht inode ctx.

Change-Id: I7693c18445f138221d8417df5e95b118cedb818a
BUG: 1395261
Signed-off-by: N Balachandran 
Reviewed-on: http://review.gluster.org/15847
Smoke: Gluster Build System 
Reviewed-by: Shyamsundar Ranganathan 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Atin Mukherjee

trivial: correct some spelling mistakes in comments and logs

2016-10-18T10:27:12+00:00

BUG: 1385593
Change-Id: Icfae9e557a284182c6c22e9606fdd641528906f0
Reported-by: Patrick Matthäi 
Signed-off-by: Niels de Vos 
Reviewed-on: http://review.gluster.org/15656
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Atin Mukherjee 
Reviewed-by: jiffin tony Thottan 
Reviewed-by: Kotresh HR 
Smoke: Gluster Build System

xlators/{dht,tier}: fix unused variable warnings/errors

2016-09-14T04:08:36+00:00

http://review.gluster.org/14085 fixes a "pragma leak" where the
generated rpc/xdr headers have a pair of pragmas that disable these
warnings. With the warnings disabled, many unused variables have
crept into the code base.

And 14085 won't pass its own smoke test until all these warnings are
fixed.

BUG: 1369124
Change-Id: I6feee863927254ae9f59013112bcc297ad09e89b
Signed-off-by: Kaleb S. KEITHLEY 
Reviewed-on: http://review.gluster.org/15477
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Dan Lambright 
CentOS-regression: Gluster Build System 
Reviewed-by: N Balachandran

dht: "replica.split-brain-status" attribute value is not correct

2016-09-12T07:38:29+00:00

Problem: In a distributed-replicate volume attribute
         "replica.split-brain-status" value does not display split-brain
           condition though directory is in split-brain.
         If directory is in split brain on mutiple replica-pairs
         it does not show full list of replica pairs.

Solution: Update the dht_aggregate code to aggregate the xattr
          value in this specific condition.

Fix:      1) function getChoices returns the choices from split-brain
             status string.
          2) function add_opt adding the choices to local buffer to
             store in dictionary
          3) For the key "replica.split-brain-status" function dht_aggregate
             call dht_aggregate_split_brain_xattr to prepare the list.

Test:     To verify the patch followed below steps
          1) Create a distributed replica volume and create mount point
          2) Stop heal daemon
          3) Touch file and directories on mount point
             mkdir test{1..5};touch tmp{1..5}
          4) Down brick process on one of the replica set
             pkill -9 glusterfsd
          5) Change permission of dir on mount point
             chmod 755 test{1..5}
          6) Restart brick process on node with force option
          7) kill brick process on other node in same replica set
          8) Change permission of dir again on mount point
             chmod 766 test{1..5}
          9) Reexecute same step from 4-9 on other replica set also
          10) After check heal status on server it will show dir's are
              in split brain on all replica sets
          11) After check the replica.split-brain-status attr on mount
              point it will show wrong status of split brain.
          12) After apply the patch the attribute shows correct value.

BUG: 1368312
Change-Id: Icdfd72005a4aa82337c342762775a3d1761bbe4a
Signed-off-by: Mohit Agrawal 
Reviewed-on: http://review.gluster.org/15201
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Raghavendra G