<feed xmlns='http://www.w3.org/2005/Atom'>
<title>glusterfs.git/xlators/cluster/ec/src/ec-inode-write.c, branch v7.0alpha</title>
<subtitle></subtitle>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/'/>
<entry>
<title>multiple files: another attempt to remove includes</title>
<updated>2019-06-14T16:50:32+00:00</updated>
<author>
<name>Yaniv Kaul</name>
<email>ykaul@redhat.com</email>
</author>
<published>2019-06-09T10:31:31+00:00</published>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/commit/?id=0a6fe8551ac9807a8b6ad62241ec8048cf9f9025'/>
<id>0a6fe8551ac9807a8b6ad62241ec8048cf9f9025</id>
<content type='text'>
There are many include statements that are not needed.
A previous more ambitious attempt failed because of *BSD plafrom
(see https://review.gluster.org/#/c/glusterfs/+/21929/ )

Now trying a more conservative reduction.
It does not solve all circular deps that we have, but it
does reduce some of them. There is just too much to handle
reasonably (dht-common.h includes dht-lock.h which includes
dht-common.h ...), but it does reduce the overall number of lines
of include we need to look at in the future to understand and fix
the mess later one.

Change-Id: I550cd001bdefb8be0fe67632f783c0ef6bee3f9f
updates: bz#1193929
Signed-off-by: Yaniv Kaul &lt;ykaul@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There are many include statements that are not needed.
A previous more ambitious attempt failed because of *BSD plafrom
(see https://review.gluster.org/#/c/glusterfs/+/21929/ )

Now trying a more conservative reduction.
It does not solve all circular deps that we have, but it
does reduce some of them. There is just too much to handle
reasonably (dht-common.h includes dht-lock.h which includes
dht-common.h ...), but it does reduce the overall number of lines
of include we need to look at in the future to understand and fix
the mess later one.

Change-Id: I550cd001bdefb8be0fe67632f783c0ef6bee3f9f
updates: bz#1193929
Signed-off-by: Yaniv Kaul &lt;ykaul@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cluster/ec: fix fd reopen</title>
<updated>2019-04-23T11:28:58+00:00</updated>
<author>
<name>Xavi Hernandez</name>
<email>xhernandez@redhat.com</email>
</author>
<published>2019-04-12T15:54:44+00:00</published>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/commit/?id=4f0db1373be93e05b6fc451d2f07514704d3c4ca'/>
<id>4f0db1373be93e05b6fc451d2f07514704d3c4ca</id>
<content type='text'>
Currently EC tries to reopen fd's that have been opened while a brick
was down. This is done as part of regular write operations, just after
having acquired the locks, and it's sent as a sub-fop of the main write
fop.

There were two problems:

1. The reopen was attempted on all UP bricks, even if a previous lock
didn't succeed. This is incorrect because most probably the open will
fail.

2. If reopen is sent and fails, the error is propagated to the main
operation, causing it to fail when it shouldn't.

To fix this, we only attempt reopens on bricks where the current fop
owns a lock, and we prevent any error to be propagated to the main
fop.

To implement this behaviour an argument used to indicate the minimum
number of required answers has overloaded to also include some flags. To
make the change consistent, it has been necessary to rename the
argument, which means that a lot of files have been changed. However
there are no functional changes.

This change has also uncovered a problem in discard code, which didn't
correctely process requests of small sizes because no real discard fop
was being processed, only a write of 0's on some region. In this case
some fields of the fop remained uninitialized or with incorrect values.
To fix this, a new function has been created to simulate success on a
fop and it's used in the discard case.

Thanks to Pranith for providing a test script that has also detected an
issue in this patch. This patch includes a small modification of this
script to force data to be written into bricks before stopping them.

Change-Id: If272343873369186c2fb8f43c1d9c52c3ea304ec
Fixes: bz#1699866
Signed-off-by: Xavi Hernandez &lt;xhernandez@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently EC tries to reopen fd's that have been opened while a brick
was down. This is done as part of regular write operations, just after
having acquired the locks, and it's sent as a sub-fop of the main write
fop.

There were two problems:

1. The reopen was attempted on all UP bricks, even if a previous lock
didn't succeed. This is incorrect because most probably the open will
fail.

2. If reopen is sent and fails, the error is propagated to the main
operation, causing it to fail when it shouldn't.

To fix this, we only attempt reopens on bricks where the current fop
owns a lock, and we prevent any error to be propagated to the main
fop.

To implement this behaviour an argument used to indicate the minimum
number of required answers has overloaded to also include some flags. To
make the change consistent, it has been necessary to rename the
argument, which means that a lot of files have been changed. However
there are no functional changes.

This change has also uncovered a problem in discard code, which didn't
correctely process requests of small sizes because no real discard fop
was being processed, only a write of 0's on some region. In this case
some fields of the fop remained uninitialized or with incorrect values.
To fix this, a new function has been created to simulate success on a
fop and it's used in the discard case.

Thanks to Pranith for providing a test script that has also detected an
issue in this patch. This patch includes a small modification of this
script to force data to be written into bricks before stopping them.

Change-Id: If272343873369186c2fb8f43c1d9c52c3ea304ec
Fixes: bz#1699866
Signed-off-by: Xavi Hernandez &lt;xhernandez@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ec: fix truncate lock to cover the write in tuncate clean</title>
<updated>2019-04-12T11:37:45+00:00</updated>
<author>
<name>Kinglong Mee</name>
<email>kinglongmee@gmail.com</email>
</author>
<published>2019-04-12T03:35:55+00:00</published>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/commit/?id=0e1223491e964096384edfae5032ed0d50d028ad'/>
<id>0e1223491e964096384edfae5032ed0d50d028ad</id>
<content type='text'>
ec_truncate_clean does writing under the lock granted for truncate,
but the lock is calculated by ec_adjust_offset_up, so that,
the write in ec_truncate_clean is out of lock.

Updates: bz#1699189
Change-Id: Idbe1fd48d26afe49c36b77db9f12e0907f5a4134
Signed-off-by: Kinglong Mee &lt;kinglongmee@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ec_truncate_clean does writing under the lock granted for truncate,
but the lock is calculated by ec_adjust_offset_up, so that,
the write in ec_truncate_clean is out of lock.

Updates: bz#1699189
Change-Id: Idbe1fd48d26afe49c36b77db9f12e0907f5a4134
Signed-off-by: Kinglong Mee &lt;kinglongmee@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>libglusterfs: Move devel headers under glusterfs directory</title>
<updated>2018-12-05T21:47:04+00:00</updated>
<author>
<name>ShyamsundarR</name>
<email>srangana@redhat.com</email>
</author>
<published>2018-11-29T19:08:06+00:00</published>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/commit/?id=20ef211cfa5b5fcc437484a879fdc5d4c66bbaf5'/>
<id>20ef211cfa5b5fcc437484a879fdc5d4c66bbaf5</id>
<content type='text'>
libglusterfs devel package headers are referenced in code using
include semantics for a program, this while it works can be better
especially when dealing with out of tree xlator builds or in
general out of tree devel package usage.

Towards this, the following changes are done,
- moved all devel headers under a glusterfs directory
- Included these headers using system header notation &lt;&gt; in all
code outside of libglusterfs
- Included these headers using own program notation "" within
libglusterfs

This change although big, is just moving around the headers and
making it correct when including these headers from other sources.

This helps us correctly include libglusterfs includes without
namespace conflicts.

Change-Id: Id2a98854e671a7ee5d73be44da5ba1a74252423b
Updates: bz#1193929
Signed-off-by: ShyamsundarR &lt;srangana@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
libglusterfs devel package headers are referenced in code using
include semantics for a program, this while it works can be better
especially when dealing with out of tree xlator builds or in
general out of tree devel package usage.

Towards this, the following changes are done,
- moved all devel headers under a glusterfs directory
- Included these headers using system header notation &lt;&gt; in all
code outside of libglusterfs
- Included these headers using own program notation "" within
libglusterfs

This change although big, is just moving around the headers and
making it correct when including these headers from other sources.

This helps us correctly include libglusterfs includes without
namespace conflicts.

Change-Id: Id2a98854e671a7ee5d73be44da5ba1a74252423b
Updates: bz#1193929
Signed-off-by: ShyamsundarR &lt;srangana@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>all: fix warnings on non 64-bits architectures</title>
<updated>2018-10-10T05:50:29+00:00</updated>
<author>
<name>Xavi Hernandez</name>
<email>xhernandez@redhat.com</email>
</author>
<published>2018-09-25T11:22:47+00:00</published>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/commit/?id=2d96ce8faa277809c0c94aca54320483889f577d'/>
<id>2d96ce8faa277809c0c94aca54320483889f577d</id>
<content type='text'>
When compiling in other architectures there appear many warnings. Some
of them are actual problems that prevent gluster to work correctly on
those architectures.

Change-Id: Icdc7107a2bc2da662903c51910beddb84bdf03c0
fixes: bz#1632717
Signed-off-by: Xavi Hernandez &lt;xhernandez@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When compiling in other architectures there appear many warnings. Some
of them are actual problems that prevent gluster to work correctly on
those architectures.

Change-Id: Icdc7107a2bc2da662903c51910beddb84bdf03c0
fixes: bz#1632717
Signed-off-by: Xavi Hernandez &lt;xhernandez@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Land part 2 of clang-format changes</title>
<updated>2018-09-12T12:22:45+00:00</updated>
<author>
<name>Gluster Ant</name>
<email>bugzilla-bot@gluster.org</email>
</author>
<published>2018-09-12T12:22:45+00:00</published>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/commit/?id=e16868dede6455cab644805af6fe1ac312775e13'/>
<id>e16868dede6455cab644805af6fe1ac312775e13</id>
<content type='text'>
Change-Id: Ia84cc24c8924e6d22d02ac15f611c10e26db99b4
Signed-off-by: Nigel Babu &lt;nigelb@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Change-Id: Ia84cc24c8924e6d22d02ac15f611c10e26db99b4
Signed-off-by: Nigel Babu &lt;nigelb@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>All: run codespell on the code and fix issues.</title>
<updated>2018-07-22T14:40:16+00:00</updated>
<author>
<name>Yaniv Kaul</name>
<email>ykaul@redhat.com</email>
</author>
<published>2018-07-16T14:03:17+00:00</published>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/commit/?id=621138ce763eda8270d0a4f6d7209fd50ada8787'/>
<id>621138ce763eda8270d0a4f6d7209fd50ada8787</id>
<content type='text'>
Please review, it's not always just the comments that were fixed.
I've had to revert of course all calls to creat() that were changed
to create() ...

Only compile-tested!

Change-Id: I7d02e82d9766e272a7fd9cc68e51901d69e5aab5
updates: bz#1193929
Signed-off-by: Yaniv Kaul &lt;ykaul@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Please review, it's not always just the comments that were fixed.
I've had to revert of course all calls to creat() that were changed
to create() ...

Only compile-tested!

Change-Id: I7d02e82d9766e272a7fd9cc68e51901d69e5aab5
updates: bz#1193929
Signed-off-by: Yaniv Kaul &lt;ykaul@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://git.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: EC DISCARD doesn't punch hole properly</title>
<updated>2017-11-28T09:34:33+00:00</updated>
<author>
<name>Sunil Kumar Acharya</name>
<email>sheggodu@redhat.com</email>
</author>
<published>2017-11-22T09:42:26+00:00</published>
<link rel='alternate' type='text/html' href='http://git.gluster.org/cgit/glusterfs.git/commit/?id=bdd7ad3787beebcf55340f7ebb495d42002516d2'/>
<id>bdd7ad3787beebcf55340f7ebb495d42002516d2</id>
<content type='text'>
Problem:
DISCARD operation on EC volume was punching hole of lesser
size than the specified size in some cases.

Solution:
EC was not handling punch hole for tail part in some cases.
Updated the code to handle it appropriately.

BUG: 1516206
Change-Id: If3e69e417c3e5034afee04e78f5f78855e65f932
Signed-off-by: Sunil Kumar Acharya &lt;sheggodu@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Problem:
DISCARD operation on EC volume was punching hole of lesser
size than the specified size in some cases.

Solution:
EC was not handling punch hole for tail part in some cases.
Updated the code to handle it appropriately.

BUG: 1516206
Change-Id: If3e69e417c3e5034afee04e78f5f78855e65f932
Signed-off-by: Sunil Kumar Acharya &lt;sheggodu@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://git.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>
</feed>
