glusterfs.git/xlators/mgmt/glusterd/src/glusterd-locks.c, branch v3.7.0beta1

Avoid conflict between contrib/uuid and system uuid

2015-04-04T17:48:35+00:00

glusterfs relies on Linux uuid implementation, which
API is incompatible with most other systems's uuid. As
a result, libglusterfs has to embed contrib/uuid,
which is the Linux implementation, on non Linux systems.
This implementation is incompatible with systtem's
built in, but the symbols have the same names.

Usually this is not a problem because when we link
with -lglusterfs, libc's symbols are trumped. However
there is a problem when a program not linked with
-lglusterfs will dlopen() glusterfs component. In
such a case, libc's uuid implementation is already
loaded in the calling program, and it will be used
instead of libglusterfs's implementation, causing
crashes.

A possible workaround is to use pre-load libglusterfs
in the calling program (using LD_PRELOAD on NetBSD for
instance), but such a mechanism is not portable, nor
is it flexible. A much better approach is to rename
libglusterfs's uuid_* functions to gf_uuid_* to avoid
any possible conflict. This is what this change attempts.

BUG: 1206587
Change-Id: I9ccd3e13afed1c7fc18508e92c7beb0f5d49f31a
Signed-off-by: Emmanuel Dreyfus 
Reviewed-on: http://review.gluster.org/10017
Tested-by: Gluster Build System 
Reviewed-by: Niels de Vos

glusterd: statedump support

2014-10-15T10:02:40+00:00

Although glusterd currently has statedump support but it doesn't dump its
context information. Implementing glusterd_dump_priv function to export per-node
glusterd information would be useful for debugging bugs. Once implemented, we
could enhance sos-report to fetch this information. This would potentially
reduce our time to root cause and data needed for debugability can be dumped
gradually.

Following is the main items of the dump list targeted in this patch :

    * Supported max/min op-version and current op-version
    * Information about peer list
    * Information about peer list involved while a transaction is going on
      (xaction_peers)
    * option dictionary in glusterd_conf_t
    * mgmt_v3_lock in glusterd_conf_t
    * List of connected clients
    * uuid of glusterd
    * A section of rpc related information like live connections and their
      statistics

There are couple of issues which were found during implementation and testing
phase:
 - xaction_peers of glusterd_conf_t was not initialized in init because of which
   traversing through this list head was crashing when there was no active
   transaction
 - gf_free was not setting the typestr to NULL if the the alloc count becomes 0
   for a mem-type earlier allocated.

Change-Id: Ic9bce2d57682fc1771cd2bc6af0b7316ecbc761f
BUG: 1139682
Signed-off-by: Atin Mukherjee 
Reviewed-on: http://review.gluster.org/8665
Tested-by: Gluster Build System 
Reviewed-by: Kaushal M

glusterd: Add last successful glusterd lock backtrace

2014-09-22T11:08:58+00:00

Also, moved the backtrace fetching logic to a separate function.
Modified the backtrace fetching logic able to work under memory pressure
conditions.

Change-Id: Ie38bea425a085770f41831314aeda95595177ece
BUG: 1138503
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/8584
Tested-by: Gluster Build System 
Reviewed-by: Jeff Darcy 
Reviewed-by: Atin Mukherjee

glusterd: Improve debugging experience for glusterd locks

2014-09-03T10:16:44+00:00

Today, when glusterd's internal locking mechanism fails
with invalid type or when another competing lock is being
held, the log message doesn't provide enough information
directly as to which command saw this (first). Following
is a snippet of how a failure would look in the log file.
This would greatly assist in debugging.

[2014-09-03 04:57:58.549418] E
[glusterd-locks.c:520:glusterd_mgmt_v3_lock]
(-->/usr/local/lib/glusterfs/3.7dev/xlator/mgmt/glusterd.so(__glusterd_handle_create_volume+0x801)
[0x7f30b071e651]
(-->/usr/local/lib/glusterfs/3.7dev/xlator/mgmt/glusterd.so(glusterd_op_begin_synctask+0x2c)
[0x7f30b072e19c]
(-->/usr/local/lib/glusterfs/3.7dev/xlator/mgmt/glusterd.so(gd_sync_task_begin+0x55d)
[0x7f30b072de6d]))) 0-management: Invalid entity. Cannot perform locking
operation on vol types

Change-Id: I0595f49d60e620e8b065f3506bdb147ccee383a7
Signed-off-by: Krishnan Parthasarathi 
Reviewed-on: http://review.gluster.org/8580
Reviewed-by: Atin Mukherjee 
Tested-by: Gluster Build System 
Reviewed-by: Kaushal M

gluster: GlusterFS Volume Snapshot Feature

2014-04-11T23:29:17+00:00

This is the initial patch for the Snapshot feature. Current patch
includes following features:
* Snapshot create
* Snapshot delete
* Snapshot restore
* Snapshot list
* Snapshot info
* Snapshot status
* Snapshot config

Change-Id: I2f46920c0d61c515f6a60e0f8b46fff886d9f6a9
BUG: 1061685
Signed-off-by: shishir gowda 
Signed-off-by: Sachin Pandit 
Signed-off-by: Vijaikumar M 
Signed-off-by: Raghavendra Bhat 
Signed-off-by: Rajesh Joseph 
Signed-off-by: Joseph Fernandes 
Signed-off-by: Avra Sengupta 
Reviewed-on: http://review.gluster.org/7128
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterd/Vol-Locks : Moving globals into glusterd priv and code refactoring

2014-02-14T15:05:30+00:00

Moved globals(vol_lock and txn_opinfo dicts and global_txn_id) into
glusterd priv

Moved glusterd_op_send_cli_response() out of gd_unlock_op_phase
as gd_unlock_op_phase and glusterd_clear_txn_opinfo should only
be called if the txn id has been successfully generated. The
cli resp should be sent irrespective of that.

Changed log levels from ERROR to WARNING for some volume lock logs
where the logs are expected and is not an error

Added logs for better transparency of transaction ids.

Change-Id: Ifac9b23aa9f1648c9ae252cfd3ac50bb2ed46728
BUG: 1011470
Signed-off-by: Avra Sengupta 
Reviewed-on: http://review.gluster.org/6976
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

glusterd: Volume locks and transaction specific opinfos

2014-02-11T07:25:40+00:00

With this patch we are replacing the existing cluster-wide
lock taken on glusterds across the cluster, with volume locks
which are also taken on glusterds across the cluster, but are
volume specific. So with the volume locks we are able to perform
more than one gluster operation at the same time, as long as the
operations are being performed on different volumes.

We maintain a global list of volume-locks (using a dict for a list)
where the key is the volume name, and which saves the uuid of the
originator glusterd. These locks are held and released per volume
transaction.

In order to acheive multiple gluster operations occuring at the
same time, we also separate opinfos in the op-state-machine, as a
part of this patch. To do so, we generate a unique transaction-id
(uuid) per gluster transaction. An opinfo is then associated with
this transaction id, which is used throughout the transaction. We
maintain a run-time global list(using a dict) of transaction-ids,
and their respective opinfos to achieve this.

Upstream Feature Page: http://www.gluster.org/community/documentation/index.php/Features/glusterd-volume-locks

Change-Id: Iaad505a854bac8de8f83beec0357eb6cde3f7ea8
BUG: 1011470
Signed-off-by: Avra Sengupta 
Reviewed-on: http://review.gluster.org/5994
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur