glusterfs.git/xlators/performance/io-cache, branch v3.8dev

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

glfs_fini: Clean up all the resources allocated in glfs_new.

2015-03-04T15:15:12+00:00

Initially even after calling glfs_fini(), all the threads created
during init and many other resources like memory pool, iobuf pool,
event pool and other memory allocs were not being freed.
With this patch these resources are freed in glfs_fini().

The two thumb rules followed in this patch are:
- The threads are not killed, they are made to exit voluntarily,
once the queued tasks are completed. The main thread waits for
the other threads to exit.
- Free the memory pools and destroy the graphs only after all the
other threads are stopped, so that there are less chances of
hitting access after free.

Resources freed and its order:
1. Destroy the inode table of all the graphs - Call forget on all the inodes.
This will not be required when the cleanup during graph switch is
implemented to perform inode table destroy.
2. Deactivate the current graph, call fini of all the xlators.
3. Syncenv destroy - Join the synctask threads and cleanup syncenv resources
Sets the destroy mode, complete the existing synctasks, then join the
synctask threads.
After entering the destroy mode,
-if a new synctask is submitted, it fails.
-if syncenv_new() is called, it will end up creating new threads,
but this is called only during init.
4. Poller thread destroy
Register an event handler which sets the destroy mode for the poller.
Once the poller is done processing all the events, it exits.
5. Tear down the logging framework
The log file is closed and the log level is set to none, after this
point no log messages appear either in log file or in stderr.
6. Destroy the timer thread
Set the destroy bit, once the pending timer events are processed
the timer thread exits.
Note: Log infrastructure should be shutdown before destroying the timer
thread as gf_log uses timers.
7. Destroy the glusterfs_ctx_t
For all the graphs(active and passive), free graph, xlator structs and few other lists.
Free the memory pools - iobuf pool, event pool, dict, logbuf pool,
stub mem pool, stack mem pool, frame mem pool.

Few things not addressed in this patch:
1. rpc_transport object not destroyed, the PARENT_DOWN should have
destroyed this object but has not, needs to be addressed as a part
of different patch
2. Each xlator fini should clean up the local pool allocated by its xlator.
Needs to be addresses as a part of different patch.
3. Each xlator should implement forget to free its inode_ctx.
Needs to be addresses as a part of different patch.
3. Few other leaks reported by valgrind.
4. fd and fd contexts

The numbers:
The resource usage by the test case in this patch:
Without the fix, Memory: ~3GB; Threads: ~81
With this fix, Memory: 300MB; Threads: 1(main thread)

Change-Id: I96b9277541737aa8372b4e6c9eed380cb871e7c2
BUG: 1093594
Signed-off-by: Poornima G
Reviewed-on: http://review.gluster.org/7642
Tested-by: Gluster Build System
Reviewed-by: Rajesh Joseph
Reviewed-by: Raghavendra Talur
Reviewed-by: Krishnan Parthasarathi
Reviewed-by: Pranith Kumar Karampuri
Reviewed-by: Shyamsundar Ranganathan

build: MacOSX Porting fixes

2014-04-24T21:41:48+00:00

git@forge.gluster.org:~schafdog/glusterfs-core/osx-glusterfs

Working functionality on MacOSX

 - GlusterD (management daemon)
 - GlusterCLI (management cli)
 - GlusterFS FUSE (using OSXFUSE)
 - GlusterNFS (without NLM - issues with rpc.statd)

Change-Id: I20193d3f8904388e47344e523b3787dbeab044ac
BUG: 1089172
Signed-off-by: Harshavardhana 
Signed-off-by: Dennis Schafroth 
Tested-by: Harshavardhana 
Tested-by: Dennis Schafroth 
Reviewed-on: http://review.gluster.org/7503
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

io-cache: Unlock and then goto out in failure case.

2014-02-17T16:09:55+00:00

Fix for coverity bug CID:1124625

Change-Id: I76df453a17f2af7c48a80b6fc0ccd411ab96e371
BUG: 789278
Signed-off-by: Raghavendra Talur 
Reviewed-on: http://review.gluster.org/6949
Reviewed-by: Santosh Pradhan 
Tested-by: Gluster Build System

performance/io-cache: Fix dereferencing of freed pointer

2014-02-13T01:35:43+00:00

Change-Id: Ic4276c6d76c36f4eb77282dc06d2b8b212b58f08
BUG: 789278
Signed-off-by: Poornima 
Reviewed-on: http://review.gluster.org/6822
Reviewed-by: Raghavendra G 
Tested-by: Gluster Build System

performance/io-cache: Fix for the bugs reported by coverity

2014-02-11T01:05:20+00:00

Change-Id: I24c10d874511a2f24dda2fb84d31f5074da1616f
BUG: 789278
Signed-off-by: Poornima 
Reviewed-on: http://review.gluster.org/6869
Reviewed-by: Raghavendra G 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

performance/io-cache: reduce the severity of log-message

2014-01-03T16:02:43+00:00

During a genuine error condition like network outage, the log grows
with redundant information.

Change-Id: I5a4f2f62da10ef656f14200c4c84a6917b1f0ddd
Signed-off-by: Raghavendra G 
BUG: 1048084
Reviewed-on: http://review.gluster.org/6635
Reviewed-by: Pranith Kumar Karampuri 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

io-cache: handle iobref_merge() error gracefully

2013-11-26T18:31:48+00:00

.. by UNWINDing ENOMEM, rather than leaving pointer in vector pointing
to stale memory.

Change-Id: I7f3917ac056fae144f845c9d123233e91e278187
BUG: 1034398
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/6351
Tested-by: Gluster Build System 
Reviewed-by: Amar Tumballi

zerofill: Change the type of len argument of glfs_zerofill() to off_t

2013-11-15T07:29:48+00:00

glfs_zerofill() can be potentially called to zero-out entire file and
hence allow for bigger value of length parameter.

Change-Id: I75f1d11af298915049a3f3a7cb3890a2d72fca63
BUG: 1028673
Signed-off-by: Bharata B Rao 
Reviewed-on: http://review.gluster.org/6266
Tested-by: Gluster Build System 
Reviewed-by: M. Mohan Kumar 
Tested-by: M. Mohan Kumar 
Reviewed-by: Anand Avati

glusterfs: zerofill support

2013-11-11T05:25:49+00:00

Add support for a new ZEROFILL fop. Zerofill writes zeroes to a file in
the specified range. This fop will be useful when a whole file needs to
be initialized with zero (could be useful for zero filled VM disk image
provisioning or  during scrubbing of VM disk images).

Client/application can issue this FOP for zeroing out. Gluster server
will zero out required range of bytes ie server offloaded zeroing. In
the absence of this fop,  client/application has to repetitively issue
write (zero) fop to the server, which is very inefficient method because
of the overheads involved in RPC calls  and acknowledgements.

WRITESAME is a  SCSI T10 command that takes a block of data as input and
writes the same data to other blocks and this write is handled
completely within the storage and hence is known as offload . Linux ,now
has support for SCSI WRITESAME command which is exposed to the user in
the form of BLKZEROOUT ioctl.  BD Xlator can exploit BLKZEROOUT ioctl to
implement this fop. Thus zeroing out operations can be completely
offloaded to the storage device , making it highly efficient.

The fop takes two arguments offset and size. It zeroes out 'size' number
of bytes in an opened file starting from 'offset' position.

This patch adds zerofill support to the following areas:
	- libglusterfs
	- io-stats
	- performance/md-cache,open-behind
	- quota
	- cluster/afr,dht,stripe
	- rpc/xdr
	- protocol/client,server
	- io-threads
	- marker
	- storage/posix
	- libgfapi

Client applications can exloit this fop by using glfs_zerofill introduced in
libgfapi.FUSE support to this fop has not been added as there is no system call
for this fop.

Changes from previous version 3:
* Removed redundant memory failure log messages

Changes from previous version 2:
* Rebased and fixed build error

Changes from previous version 1:
* Rebased for latest master

TODO :
     * Add zerofill support to trace xlator
     * Expose zerofill capability as part of gluster volume info

Here is a performance comparison of server offloaded zeofill vs zeroing
out using repeated writes.

[root@llmvm02 remote]# time ./offloaded aakash-test log 20

real	3m34.155s
user	0m0.018s
sys	0m0.040s
[root@llmvm02 remote]# time ./manually aakash-test log 20

real	4m23.043s
user	0m2.197s
sys	0m14.457s
[root@llmvm02 remote]# time ./offloaded aakash-test log 25;

real	4m28.363s
user	0m0.021s
sys	0m0.025s
[root@llmvm02 remote]# time ./manually aakash-test log 25

real	5m34.278s
user	0m2.957s
sys	0m18.808s

The argument log is a file which we want to set for logging purpose and
the third argument is size in GB .

As we can see there is a performance improvement of around 20% with this
fop.

Change-Id: I081159f5f7edde0ddb78169fb4c21c776ec91a18
BUG: 1028673
Signed-off-by: Aakash Lal Das 
Signed-off-by: M. Mohan Kumar 
Reviewed-on: http://review.gluster.org/5327
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur