<feed xmlns='http://www.w3.org/2005/Atom'>
<title>glusterfs.git/libglusterfs/src/defaults.c, branch v3.7.16</title>
<subtitle>GlusterFS is a distributed file-system capable of scaling to several petabytes. It aggregates various storage bricks over Infiniband RDMA or TCP/IP interconnect into one large parallel network file system.</subtitle>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/'/>
<entry>
<title>defaults,globals,iobuf,latency,logging,options,xlator/libglusterfs : porting to a new logging framework</title>
<updated>2015-07-13T13:10:58+00:00</updated>
<author>
<name>Mohamed Ashiq</name>
<email>ashiq333@gmail.com</email>
</author>
<published>2015-05-19T10:10:30+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=1e4cc18362df17f87001ec42605b51daf251e0db'/>
<id>1e4cc18362df17f87001ec42605b51daf251e0db</id>
<content type='text'>
        Backport of http://review.gluster.org/10826

Cherry picked from ef374774b8727b2f76915a1f88b26c83c77dde43
&gt;Change-Id: If6a55186cddc3d1c4d22e3d56b45358b84feeb49
&gt;BUG: 1194640
&gt;Signed-off-by: Mohamed Ashiq &lt;ashiq333@gmail.com&gt;
&gt;Reviewed-on: http://review.gluster.org/10826
&gt;Tested-by: NetBSD Build System &lt;jenkins@build.gluster.org&gt;
&gt;Reviewed-by: Pranith Kumar Karampuri &lt;pkarampu@redhat.com&gt;

Change-Id: If6a55186cddc3d1c4d22e3d56b45358b84feeb49
BUG: 1217722
Signed-off-by: Mohamed Ashiq &lt;ashiq333@gmail.com&gt;
Reviewed-on: http://review.gluster.org/11405
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Tested-by: NetBSD Build System &lt;jenkins@build.gluster.org&gt;
Reviewed-by: Niels de Vos &lt;ndevos@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
        Backport of http://review.gluster.org/10826

Cherry picked from ef374774b8727b2f76915a1f88b26c83c77dde43
&gt;Change-Id: If6a55186cddc3d1c4d22e3d56b45358b84feeb49
&gt;BUG: 1194640
&gt;Signed-off-by: Mohamed Ashiq &lt;ashiq333@gmail.com&gt;
&gt;Reviewed-on: http://review.gluster.org/10826
&gt;Tested-by: NetBSD Build System &lt;jenkins@build.gluster.org&gt;
&gt;Reviewed-by: Pranith Kumar Karampuri &lt;pkarampu@redhat.com&gt;

Change-Id: If6a55186cddc3d1c4d22e3d56b45358b84feeb49
BUG: 1217722
Signed-off-by: Mohamed Ashiq &lt;ashiq333@gmail.com&gt;
Reviewed-on: http://review.gluster.org/11405
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Tested-by: NetBSD Build System &lt;jenkins@build.gluster.org&gt;
Reviewed-by: Niels de Vos &lt;ndevos@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libglusterfs: Implement cluster-syncop</title>
<updated>2015-05-05T10:14:25+00:00</updated>
<author>
<name>Pranith Kumar K</name>
<email>pkarampu@redhat.com</email>
</author>
<published>2015-04-14T08:15:33+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=7dd7d6ce904661173bdbb156e23d096f9b02464e'/>
<id>7dd7d6ce904661173bdbb156e23d096f9b02464e</id>
<content type='text'>
        Backport of http://review.gluster.org/10240

This patch implements syncop equivalent for cluster of xlators. The xlators on
which the fop needs to be performed is taken in input arguments to the
functions and the responses are gathered and provided as the output.

This idea is taken from afr-v2 self-heal implementation by Avati.

BUG: 1216303
Change-Id: I189400ea5bb3205aae928a72afbb6c960968b65a
Signed-off-by: Pranith Kumar K &lt;pkarampu@redhat.com&gt;
Reviewed-on: http://review.gluster.org/10439
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Vijay Bellur &lt;vbellur@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
        Backport of http://review.gluster.org/10240

This patch implements syncop equivalent for cluster of xlators. The xlators on
which the fop needs to be performed is taken in input arguments to the
functions and the responses are gathered and provided as the output.

This idea is taken from afr-v2 self-heal implementation by Avati.

BUG: 1216303
Change-Id: I189400ea5bb3205aae928a72afbb6c960968b65a
Signed-off-by: Pranith Kumar K &lt;pkarampu@redhat.com&gt;
Reviewed-on: http://review.gluster.org/10439
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Vijay Bellur &lt;vbellur@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>every/where: add GF_FOP_IPC for inter-translator communication</title>
<updated>2015-03-17T14:02:15+00:00</updated>
<author>
<name>Jeff Darcy</name>
<email>jdarcy@redhat.com</email>
</author>
<published>2015-03-11T00:14:47+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=0d2bed70faed3c63f25ed9269dc55562973ef9b7'/>
<id>0d2bed70faed3c63f25ed9269dc55562973ef9b7</id>
<content type='text'>
Several features - e.g. encryption, erasure codes, or NSR - involve
multiple cooperating translators which sometimes need a "private" means
of communication amongst themselves.  Historically we've used virtual or
synthetic xattrs, but that's not very elegant and clutters up the
getxattr/setxattr path which must also handle real xattr requests.  This
new fop should address that.

The only argument is an int32_t "op" which should be recognized by the
target translator.  It is recommended that translators using these
feature follow some convention regarding the ops that they define, to
avoid conflicts.  Using a hash of the target translator's type string as
a base for a series of ops would probably be a good start.  Any other
information can be passed in both directions using xdata.

The default behavior for this fop, as with any other, is to pass through
to FIRST_CHILD.  That makes use of this fop "transparent" to other
translators that were written before it existed, but it also means that
it only really works with pass-through translators.  If a routing
translator (such as DHT) or a fan-out translator (such as AFR) is
involved, the IPC might not reach its intended destination unless those
translators are modified to forward IPC fops along all paths.

If an IPC gets all the way to storage/posix it is considered an error,
much like an uncaught exception.  We don't actually *do* anything in
that case, but we do log it send back an EOPNOTSUPP error.  This makes
the "unrecognized opcode" condition distinguishable from the "no IPC
support" condition (which would yield an RPC error instead) so clients
can probe for the presence of a handler for their own favorite opcode
and either use that or use old-school xattrs depending on the result.

BUG: 1158628
Signed-off-by: Venky Shankar &lt;vshankar@redhat.com&gt;
Signed-off-by: Jeff Darcy &lt;jdarcy@redhat.com&gt;
Change-Id: I84af1b17babe5b30ec03ecf027ae37d09b873968
Reviewed-on: http://review.gluster.org/8812
Reviewed-by: Vijay Bellur &lt;vbellur@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Several features - e.g. encryption, erasure codes, or NSR - involve
multiple cooperating translators which sometimes need a "private" means
of communication amongst themselves.  Historically we've used virtual or
synthetic xattrs, but that's not very elegant and clutters up the
getxattr/setxattr path which must also handle real xattr requests.  This
new fop should address that.

The only argument is an int32_t "op" which should be recognized by the
target translator.  It is recommended that translators using these
feature follow some convention regarding the ops that they define, to
avoid conflicts.  Using a hash of the target translator's type string as
a base for a series of ops would probably be a good start.  Any other
information can be passed in both directions using xdata.

The default behavior for this fop, as with any other, is to pass through
to FIRST_CHILD.  That makes use of this fop "transparent" to other
translators that were written before it existed, but it also means that
it only really works with pass-through translators.  If a routing
translator (such as DHT) or a fan-out translator (such as AFR) is
involved, the IPC might not reach its intended destination unless those
translators are modified to forward IPC fops along all paths.

If an IPC gets all the way to storage/posix it is considered an error,
much like an uncaught exception.  We don't actually *do* anything in
that case, but we do log it send back an EOPNOTSUPP error.  This makes
the "unrecognized opcode" condition distinguishable from the "no IPC
support" condition (which would yield an RPC error instead) so clients
can probe for the presence of a handler for their own favorite opcode
and either use that or use old-school xattrs depending on the result.

BUG: 1158628
Signed-off-by: Venky Shankar &lt;vshankar@redhat.com&gt;
Signed-off-by: Jeff Darcy &lt;jdarcy@redhat.com&gt;
Change-Id: I84af1b17babe5b30ec03ecf027ae37d09b873968
Reviewed-on: http://review.gluster.org/8812
Reviewed-by: Vijay Bellur &lt;vbellur@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Upcall: New xlator to store various states and send cbk events</title>
<updated>2015-03-17T12:08:07+00:00</updated>
<author>
<name>Soumya Koduri</name>
<email>skoduri@redhat.com</email>
</author>
<published>2015-02-15T18:05:56+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=2b97b57cd8c71cb07b7002cf3483e9cfc9403c58'/>
<id>2b97b57cd8c71cb07b7002cf3483e9cfc9403c58</id>
<content type='text'>
Framework on the server-side, to handle certain state of the files
accessed and send notifications to the clients connected.

A generic and extensible framework, used to maintain states in
the glusterfsd process for each of the files accessed
(including the clients info doing the fops) and send
notifications to the respective glusterfs clients incase of
any change in that state.

This patch handles "Inode Update/Invalidation" upcall event.

Feature page:
        URL: http://www.gluster.org/community/documentation/index.php/Features/Upcall-infrastructure

Below link has a writeup which explains the code changes done -
        URL: https://soumyakoduri.wordpress.com/2015/02/25/glusterfs-understanding-upcall-infrastructure-and-cache-invalidation-support/

Change-Id: Ie3d724be9a3419fcf18901a753e8ec2df2ac802f
BUG: 1200262
Signed-off-by: Soumya Koduri &lt;skoduri@redhat.com&gt;
Reviewed-on: http://review.gluster.org/9535
Reviewed-by: Kaleb KEITHLEY &lt;kkeithle@redhat.com&gt;
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Framework on the server-side, to handle certain state of the files
accessed and send notifications to the clients connected.

A generic and extensible framework, used to maintain states in
the glusterfsd process for each of the files accessed
(including the clients info doing the fops) and send
notifications to the respective glusterfs clients incase of
any change in that state.

This patch handles "Inode Update/Invalidation" upcall event.

Feature page:
        URL: http://www.gluster.org/community/documentation/index.php/Features/Upcall-infrastructure

Below link has a writeup which explains the code changes done -
        URL: https://soumyakoduri.wordpress.com/2015/02/25/glusterfs-understanding-upcall-infrastructure-and-cache-invalidation-support/

Change-Id: Ie3d724be9a3419fcf18901a753e8ec2df2ac802f
BUG: 1200262
Signed-off-by: Soumya Koduri &lt;skoduri@redhat.com&gt;
Reviewed-on: http://review.gluster.org/9535
Reviewed-by: Kaleb KEITHLEY &lt;kkeithle@redhat.com&gt;
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>defaults: add new symbol default_fops</title>
<updated>2014-04-21T01:06:57+00:00</updated>
<author>
<name>Anand Avati</name>
<email>avati@redhat.com</email>
</author>
<published>2014-03-26T17:59:27+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=a67630b3970f9ad035a1d1463d9c2a6c6e7de736'/>
<id>a67630b3970f9ad035a1d1463d9c2a6c6e7de736</id>
<content type='text'>
with members filled with pointers to appropriate default methods

Change-Id: I6cdc43e4f6776e2ad45cd5cbca5642e0c639ffde
BUG: 1089216
Signed-off-by: Anand Avati &lt;avati@redhat.com&gt;
Reviewed-on: http://review.gluster.org/7504
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Pranith Kumar Karampuri &lt;pkarampu@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
with members filled with pointers to appropriate default methods

Change-Id: I6cdc43e4f6776e2ad45cd5cbca5642e0c639ffde
BUG: 1089216
Signed-off-by: Anand Avati &lt;avati@redhat.com&gt;
Reviewed-on: http://review.gluster.org/7504
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Pranith Kumar Karampuri &lt;pkarampu@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>features/barrier: add barrier translator</title>
<updated>2014-04-07T07:59:50+00:00</updated>
<author>
<name>Varun Shastry</name>
<email>vshastry@redhat.com</email>
</author>
<published>2014-02-05T07:32:34+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=b69c4c843ce0c6a361c46fd53cbbbb9ce0e27cd8'/>
<id>b69c4c843ce0c6a361c46fd53cbbbb9ce0e27cd8</id>
<content type='text'>
gluster feature page:
http://www.gluster.org/community/documentation/index.php/Features/Server-side_Barrier_feature

Change-Id: Ia9f8802a54d1ffbd1cf789b80f5d30819bf65f64
BUG: 1060002
Signed-off-by: Varun Shastry &lt;vshastry@redhat.com&gt;
Reviewed-on: http://review.gluster.org/6928
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Krishnan Parthasarathi &lt;kparthas@redhat.com&gt;
Reviewed-by: Atin Mukherjee &lt;amukherj@redhat.com&gt;
Reviewed-by: Vijay Bellur &lt;vbellur@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
gluster feature page:
http://www.gluster.org/community/documentation/index.php/Features/Server-side_Barrier_feature

Change-Id: Ia9f8802a54d1ffbd1cf789b80f5d30819bf65f64
BUG: 1060002
Signed-off-by: Varun Shastry &lt;vshastry@redhat.com&gt;
Reviewed-on: http://review.gluster.org/6928
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Krishnan Parthasarathi &lt;kparthas@redhat.com&gt;
Reviewed-by: Atin Mukherjee &lt;amukherj@redhat.com&gt;
Reviewed-by: Vijay Bellur &lt;vbellur@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>performance/io-threads: Remove code duplication</title>
<updated>2014-02-25T02:56:06+00:00</updated>
<author>
<name>Pranith Kumar K</name>
<email>pkarampu@redhat.com</email>
</author>
<published>2014-02-15T12:24:38+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=868287aa5f70bdfcf7f56663e042d74fe1acf0db'/>
<id>868287aa5f70bdfcf7f56663e042d74fe1acf0db</id>
<content type='text'>
Change-Id: Ic905cc6074c796efce2972857b79ab53700a2de4
BUG: 1065657
Signed-off-by: Pranith Kumar K &lt;pkarampu@redhat.com&gt;
Reviewed-on: http://review.gluster.org/7010
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Anand Avati &lt;avati@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Change-Id: Ic905cc6074c796efce2972857b79ab53700a2de4
BUG: 1065657
Signed-off-by: Pranith Kumar K &lt;pkarampu@redhat.com&gt;
Reviewed-on: http://review.gluster.org/7010
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Anand Avati &lt;avati@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>zerofill: Change the type of len argument of glfs_zerofill() to off_t</title>
<updated>2013-11-15T07:29:48+00:00</updated>
<author>
<name>Bharata B Rao</name>
<email>bharata@linux.vnet.ibm.com</email>
</author>
<published>2013-11-15T04:41:58+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=884a668a9c3e12e17d64ebd5ccd9fbf3d203fd1e'/>
<id>884a668a9c3e12e17d64ebd5ccd9fbf3d203fd1e</id>
<content type='text'>
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 &lt;bharata@linux.vnet.ibm.com&gt;
Reviewed-on: http://review.gluster.org/6266
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: M. Mohan Kumar &lt;mohan@in.ibm.com&gt;
Tested-by: M. Mohan Kumar &lt;mohan@in.ibm.com&gt;
Reviewed-by: Anand Avati &lt;avati@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;bharata@linux.vnet.ibm.com&gt;
Reviewed-on: http://review.gluster.org/6266
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: M. Mohan Kumar &lt;mohan@in.ibm.com&gt;
Tested-by: M. Mohan Kumar &lt;mohan@in.ibm.com&gt;
Reviewed-by: Anand Avati &lt;avati@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>glusterfs: zerofill support</title>
<updated>2013-11-11T05:25:49+00:00</updated>
<author>
<name>M. Mohan Kumar</name>
<email>mohan@in.ibm.com</email>
</author>
<published>2013-11-09T09:21:53+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=c8fef37c5d566c906728b5f6f27baaa9a8d2a20d'/>
<id>c8fef37c5d566c906728b5f6f27baaa9a8d2a20d</id>
<content type='text'>
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 &lt;aakash@linux.vnet.ibm.com&gt;
Signed-off-by: M. Mohan Kumar &lt;mohan@in.ibm.com&gt;
Reviewed-on: http://review.gluster.org/5327
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Vijay Bellur &lt;vbellur@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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 &lt;aakash@linux.vnet.ibm.com&gt;
Signed-off-by: M. Mohan Kumar &lt;mohan@in.ibm.com&gt;
Reviewed-on: http://review.gluster.org/5327
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Vijay Bellur &lt;vbellur@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>glusterfs: discard (hole punch) support</title>
<updated>2013-06-13T21:37:43+00:00</updated>
<author>
<name>Brian Foster</name>
<email>bfoster@redhat.com</email>
</author>
<published>2013-05-23T16:19:42+00:00</published>
<link rel='alternate' type='text/html' href='https://fedorapeople.org/cgit/anoopcs/public_git/glusterfs.git/commit/?id=17f287172413dc04244781aa5302a0e4f10e2777'/>
<id>17f287172413dc04244781aa5302a0e4f10e2777</id>
<content type='text'>
Add support for the DISCARD file operation. Discard punches a hole
in a file in the provided range. Block de-allocation is implemented
via fallocate() (as requested via fuse and passed on to the brick
fs) but a separate fop is created within gluster to emphasize the
fact that discard changes file data (the discarded region is
replaced with zeroes) and must invalidate caches where appropriate.

BUG: 963678
Change-Id: I34633a0bfff2187afeab4292a15f3cc9adf261af
Signed-off-by: Brian Foster &lt;bfoster@redhat.com&gt;
Reviewed-on: http://review.gluster.org/5090
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Anand Avati &lt;avati@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add support for the DISCARD file operation. Discard punches a hole
in a file in the provided range. Block de-allocation is implemented
via fallocate() (as requested via fuse and passed on to the brick
fs) but a separate fop is created within gluster to emphasize the
fact that discard changes file data (the discarded region is
replaced with zeroes) and must invalidate caches where appropriate.

BUG: 963678
Change-Id: I34633a0bfff2187afeab4292a15f3cc9adf261af
Signed-off-by: Brian Foster &lt;bfoster@redhat.com&gt;
Reviewed-on: http://review.gluster.org/5090
Tested-by: Gluster Build System &lt;jenkins@build.gluster.com&gt;
Reviewed-by: Anand Avati &lt;avati@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
