<feed xmlns='http://www.w3.org/2005/Atom'>
<title>glusterfs.git/xlators/cluster/ec/src/ec-common.c, branch release-4.1</title>
<subtitle></subtitle>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/'/>
<entry>
<title>cluster/ec: Fix pre-op xattrop management</title>
<updated>2018-05-25T02:06:11+00:00</updated>
<author>
<name>Xavi Hernandez</name>
<email>xhernandez@redhat.com</email>
</author>
<published>2018-05-15T09:37:16+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=16b3830c337acacc1155c6d463c3ced852603e12'/>
<id>16b3830c337acacc1155c6d463c3ced852603e12</id>
<content type='text'>
Multiple pre-op xattrop can be simultaneously being processed. On the cbk
it was checked if the fop was waiting for some specific data (like size and
version) and, if so, it was assumed that this answer should contain that
data.

This is not true, since a fop can be waiting for some data, but it may come
from the xattrop of another fop.

This patch differentiates between needing some information and providing it.

This is related to parallel writes. Disabling them fixed the problem, but
also prevented concurrent reads. A change has been made so that disabling
parallel writes still allows parallel reads.

Backport of:
&gt; BUG: 1578325

Fixes: bz#1582056
Change-Id: I74772ad6b80b7b37805da93d5ec3ae099e96b041
Signed-off-by: Xavi Hernandez &lt;xhernandez@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Multiple pre-op xattrop can be simultaneously being processed. On the cbk
it was checked if the fop was waiting for some specific data (like size and
version) and, if so, it was assumed that this answer should contain that
data.

This is not true, since a fop can be waiting for some data, but it may come
from the xattrop of another fop.

This patch differentiates between needing some information and providing it.

This is related to parallel writes. Disabling them fixed the problem, but
also prevented concurrent reads. A change has been made so that disabling
parallel writes still allows parallel reads.

Backport of:
&gt; BUG: 1578325

Fixes: bz#1582056
Change-Id: I74772ad6b80b7b37805da93d5ec3ae099e96b041
Signed-off-by: Xavi Hernandez &lt;xhernandez@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: Do lock conflict check correctly for wait-list</title>
<updated>2018-02-01T09:07:20+00:00</updated>
<author>
<name>Pranith Kumar K</name>
<email>pkarampu@redhat.com</email>
</author>
<published>2018-01-31T16:40:46+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=ce9055449477dd59f29de213d140c60b03e465eb'/>
<id>ce9055449477dd59f29de213d140c60b03e465eb</id>
<content type='text'>
Problem:
ec_link_has_lock_conflict() is traversing over only owner_list
but the function is also getting called with wait_list.

Fix:
Modify ec_link_has_lock_conflict() to traverse lists correctly.
Updated the callers to reflect the changes.

BUG: 1540669
Change-Id: Ibd7ea10f4498e7c2761f9a6faac6d5cb7d750c91
Signed-off-by: Pranith Kumar K &lt;pkarampu@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Problem:
ec_link_has_lock_conflict() is traversing over only owner_list
but the function is also getting called with wait_list.

Fix:
Modify ec_link_has_lock_conflict() to traverse lists correctly.
Updated the callers to reflect the changes.

BUG: 1540669
Change-Id: Ibd7ea10f4498e7c2761f9a6faac6d5cb7d750c91
Signed-off-by: Pranith Kumar K &lt;pkarampu@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locks: added inodelk/entrylk contention upcall notifications</title>
<updated>2018-01-16T10:37:22+00:00</updated>
<author>
<name>Xavier Hernandez</name>
<email>xhernandez@datalab.es</email>
</author>
<published>2016-06-15T12:42:19+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=7ba7a4b27d124f4ee16fe4776a4670cd5b0160c4'/>
<id>7ba7a4b27d124f4ee16fe4776a4670cd5b0160c4</id>
<content type='text'>
The locks xlator now is able to send a contention notification to
the current owner of the lock.

This is only a notification that can be used to improve performance
of some client side operations that might benefit from extended
duration of lock ownership. Nothing is done if the lock owner decides
to ignore the message and to not release the lock. For forced
release of acquired resources, leases must be used.

Change-Id: I7f1ad32a0b4b445505b09908a050080ad848f8e0
Signed-off-by: Xavier Hernandez &lt;xhernandez@datalab.es&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The locks xlator now is able to send a contention notification to
the current owner of the lock.

This is only a notification that can be used to improve performance
of some client side operations that might benefit from extended
duration of lock ownership. Nothing is done if the lock owner decides
to ignore the message and to not release the lock. For forced
release of acquired resources, leases must be used.

Change-Id: I7f1ad32a0b4b445505b09908a050080ad848f8e0
Signed-off-by: Xavier Hernandez &lt;xhernandez@datalab.es&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: OpenFD heal implementation for EC</title>
<updated>2018-01-05T06:55:44+00:00</updated>
<author>
<name>Sunil Kumar Acharya</name>
<email>sheggodu@redhat.com</email>
</author>
<published>2017-03-23T07:20:41+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=78d67da17356b48cf1d5a6595764650d5b200ba7'/>
<id>78d67da17356b48cf1d5a6595764650d5b200ba7</id>
<content type='text'>
Existing EC code doesn't try to heal the OpenFD to
avoid unnecessary healing of the data later.

Fix implements the healing of open FDs before
carrying out file operations on them by making an
attempt to open the FDs on required up nodes.

BUG: 1431955
Change-Id: Ib696f59c41ffd8d5678a484b23a00bb02764ed15
Signed-off-by: Sunil Kumar Acharya &lt;sheggodu@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Existing EC code doesn't try to heal the OpenFD to
avoid unnecessary healing of the data later.

Fix implements the healing of open FDs before
carrying out file operations on them by making an
attempt to open the FDs on required up nodes.

BUG: 1431955
Change-Id: Ib696f59c41ffd8d5678a484b23a00bb02764ed15
Signed-off-by: Sunil Kumar Acharya &lt;sheggodu@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: Fix possible shift overflow</title>
<updated>2017-12-22T16:19:53+00:00</updated>
<author>
<name>Xavier Hernandez</name>
<email>jahernan@redhat.com</email>
</author>
<published>2017-12-13T16:27:42+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=41120aa8bab4ca4496bb37b8986434be404ae255'/>
<id>41120aa8bab4ca4496bb37b8986434be404ae255</id>
<content type='text'>
A coverity scan has revelaed a potential shift overflow while scanning
the bitmap of available subvolumes. The actual overflow cannot happen,
but I've changed to test used to control the limit to make it explicit.

Change-Id: Ieb55f010bbca68a1d86a93e47822f7c709a26e83
BUG: 789278
Signed-off-by: Xavier Hernandez &lt;jahernan@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A coverity scan has revelaed a potential shift overflow while scanning
the bitmap of available subvolumes. The actual overflow cannot happen,
but I've changed to test used to control the limit to make it explicit.

Change-Id: Ieb55f010bbca68a1d86a93e47822f7c709a26e83
BUG: 789278
Signed-off-by: Xavier Hernandez &lt;jahernan@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: Change [f]getxattr to parallel-dispatch-one</title>
<updated>2017-12-22T09:25:29+00:00</updated>
<author>
<name>Pranith Kumar K</name>
<email>pkarampu@redhat.com</email>
</author>
<published>2017-12-06T02:29:53+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=c96a1338fe8139d07a0aa1bc40f0843d033f0324'/>
<id>c96a1338fe8139d07a0aa1bc40f0843d033f0324</id>
<content type='text'>
At the moment in EC, [f]getxattr operations wait to acquire a lock
while other operations are in progress even when it is in the same mount with a
lock on the file/directory. This happens because [f]getxattr operations
follow the model where the operation is wound on 'k' of the bricks and are
matched to make sure the data returned is same on all of them. This consistency
check requires that no other operations are on-going while [f]getxattr
operations are wound to the bricks. We can perform [f]getxattr in
another way as well, where we find the good_mask from the lock that is already
granted and wind the operation on any one of the good bricks and unwind the
answer after adjusting size/blocks to the parent xlator. Since we are taking
into account good_mask, the reply we get will either be before or after a
possible on-going operation. Using this method, the operation doesn't need to
depend on completion of on-going operations which could be taking long time (In
case of some slow disks and writes are in progress etc). Thus we reduce the
time to serve [f]getxattr requests.

I changed [f]getxattr to dispatch-one and added extra logic in
ec_link_has_lock_conflict() to not have any conflicts for fops with
EC_MINIMUM_ONE as fop-&gt;minimum to achieve the effect described above.
Modified scripts to make sure READ fop is received in EC to trigger heals.

Updates gluster/glusterfs#368
Change-Id: I3b4ebf89181c336b7b8d5471b0454f016cdaf296
Signed-off-by: Pranith Kumar K &lt;pkarampu@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
At the moment in EC, [f]getxattr operations wait to acquire a lock
while other operations are in progress even when it is in the same mount with a
lock on the file/directory. This happens because [f]getxattr operations
follow the model where the operation is wound on 'k' of the bricks and are
matched to make sure the data returned is same on all of them. This consistency
check requires that no other operations are on-going while [f]getxattr
operations are wound to the bricks. We can perform [f]getxattr in
another way as well, where we find the good_mask from the lock that is already
granted and wind the operation on any one of the good bricks and unwind the
answer after adjusting size/blocks to the parent xlator. Since we are taking
into account good_mask, the reply we get will either be before or after a
possible on-going operation. Using this method, the operation doesn't need to
depend on completion of on-going operations which could be taking long time (In
case of some slow disks and writes are in progress etc). Thus we reduce the
time to serve [f]getxattr requests.

I changed [f]getxattr to dispatch-one and added extra logic in
ec_link_has_lock_conflict() to not have any conflicts for fops with
EC_MINIMUM_ONE as fop-&gt;minimum to achieve the effect described above.
Modified scripts to make sure READ fop is received in EC to trigger heals.

Updates gluster/glusterfs#368
Change-Id: I3b4ebf89181c336b7b8d5471b0454f016cdaf296
Signed-off-by: Pranith Kumar K &lt;pkarampu@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: Fix bugs in stripe-cache feature</title>
<updated>2017-12-05T15:46:53+00:00</updated>
<author>
<name>Ashish Pandey</name>
<email>aspandey@redhat.com</email>
</author>
<published>2017-12-05T05:33:42+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=1889e2b42917a996cef6958ee3880344028d9d9a'/>
<id>1889e2b42917a996cef6958ee3880344028d9d9a</id>
<content type='text'>
1 - This patch fixes a bug in ec_update_stripe()
that prevented some stripes to be updated after a write.

2 - This patch also include code modification for the
case in which a file does not exist and we write on
unaligned offset and user size, the last stripe on
which "end" will fall should also be cached.

Change-Id: I069cb4be1c8d59c206e3b35a6991e1fbdbc9b474
BUG: 1520758
Signed-off-by: Ashish Pandey &lt;aspandey@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
1 - This patch fixes a bug in ec_update_stripe()
that prevented some stripes to be updated after a write.

2 - This patch also include code modification for the
case in which a file does not exist and we write on
unaligned offset and user size, the last stripe on
which "end" will fall should also be cached.

Change-Id: I069cb4be1c8d59c206e3b35a6991e1fbdbc9b474
BUG: 1520758
Signed-off-by: Ashish Pandey &lt;aspandey@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: Keep last written strip in in-memory cache</title>
<updated>2017-11-10T22:15:37+00:00</updated>
<author>
<name>Ashish Pandey</name>
<email>aspandey@redhat.com</email>
</author>
<published>2017-09-18T08:37:31+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=a87abbd42e8b02deabbdfe290b16ed0d2f2e4c45'/>
<id>a87abbd42e8b02deabbdfe290b16ed0d2f2e4c45</id>
<content type='text'>
Problem:
Consider an EC volume with configuration  4 + 2.
The stripe size for this would be 512 * 4 = 2048.
That means, 2048 bytes of user data stored in one
stripe. Let's say 2048 + 512 = 2560 bytes are
already written on this volume. 512 Bytes would
be in second stripe. Now, if there are sequential
writes with offset 2560 and of size 1 Byte, we have
to read the whole stripe, encode it with 1 Byte and
then again have to write it back. Next, write with
offset 2561 and size of 1 Byte will again
READ-MODIFY-WRITE the whole stripe. This is causing
bad performance because of lots of READ request
travelling over the network.

There are some tools and scenario's where such kind
of load is coming and users are not aware of that.
Example: fio and zip

Solution:
One possible solution to deal with this issue is to
keep last stripe in memory. This way, we need not to
read it again and we can save READ fop going over the
network. Considering the above example, we have to
keep last 2048 bytes (maximum) in memory per file.

Change-Id: I3f95e6fc3ff81953646d374c445a40c6886b0b85
BUG: 1471753
Signed-off-by: Ashish Pandey &lt;aspandey@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Problem:
Consider an EC volume with configuration  4 + 2.
The stripe size for this would be 512 * 4 = 2048.
That means, 2048 bytes of user data stored in one
stripe. Let's say 2048 + 512 = 2560 bytes are
already written on this volume. 512 Bytes would
be in second stripe. Now, if there are sequential
writes with offset 2560 and of size 1 Byte, we have
to read the whole stripe, encode it with 1 Byte and
then again have to write it back. Next, write with
offset 2561 and size of 1 Byte will again
READ-MODIFY-WRITE the whole stripe. This is causing
bad performance because of lots of READ request
travelling over the network.

There are some tools and scenario's where such kind
of load is coming and users are not aware of that.
Example: fio and zip

Solution:
One possible solution to deal with this issue is to
keep last stripe in memory. This way, we need not to
read it again and we can save READ fop going over the
network. Considering the above example, we have to
keep last 2048 bytes (maximum) in memory per file.

Change-Id: I3f95e6fc3ff81953646d374c445a40c6886b0b85
BUG: 1471753
Signed-off-by: Ashish Pandey &lt;aspandey@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: Remove possibility of NULL deref</title>
<updated>2017-11-05T04:11:37+00:00</updated>
<author>
<name>Ashish Pandey</name>
<email>aspandey@redhat.com</email>
</author>
<published>2017-11-03T10:29:00+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=1160ded99bf5fcd00bd0230dfc41336af1efbe6b'/>
<id>1160ded99bf5fcd00bd0230dfc41336af1efbe6b</id>
<content type='text'>
Coverity ID: 237

Problem: In ec_check_status we are trying to deref fop-&gt;answer
which could be NULL.

Solution: Check Null condition before using this pointer.

Change-Id: I4f9a73dc2f062ca9c62b4c4baf0a6fcadade88f2
BUG: 789278
Signed-off-by: Ashish Pandey &lt;aspandey@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Coverity ID: 237

Problem: In ec_check_status we are trying to deref fop-&gt;answer
which could be NULL.

Solution: Check Null condition before using this pointer.

Change-Id: I4f9a73dc2f062ca9c62b4c4baf0a6fcadade88f2
BUG: 789278
Signed-off-by: Ashish Pandey &lt;aspandey@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: create eager-lock option for non-regular files</title>
<updated>2017-11-05T03:41:46+00:00</updated>
<author>
<name>Xavier Hernandez</name>
<email>jahernan@redhat.com</email>
</author>
<published>2017-10-16T11:57:59+00:00</published>
<link rel='alternate' type='text/html' href='http://dev.gluster.org/cgit/glusterfs.git/commit/?id=0dcd5b2feeeec7c29bd2454d6ad950d094d02b0f'/>
<id>0dcd5b2feeeec7c29bd2454d6ad950d094d02b0f</id>
<content type='text'>
A new option is added to allow independent configuration of eager
locking for regular files and non-regular files.

Change-Id: I8f80e46d36d8551011132b15c0fac549b7fb1c60
BUG: 1502610
Signed-off-by: Xavier Hernandez &lt;jahernan@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
A new option is added to allow independent configuration of eager
locking for regular files and non-regular files.

Change-Id: I8f80e46d36d8551011132b15c0fac549b7fb1c60
BUG: 1502610
Signed-off-by: Xavier Hernandez &lt;jahernan@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
