glusterfs.git/xlators/features/sdfs/src/Makefile.am, branch v7.5 build: add --without-server option 2018-02-19T17:38:55+00:00 Niels de Vos ndevos@redhat.com 2018-01-31T15:38:34+00:00 8d9961e63786cf8a9bb9e2f4140ab9a77f1ccbe3 With Gluster 4.0 we will not provide the server components for EL6 and older. At one point Gluster 4.x will get GlusterD2, which requires Golang tools in the distribution. EL6 does not contain these at the moment. With this change, it is possible to `./configure --without-server` which prevents building glusterd and the xlators for the bricks. Building RPMs can pass `--without server` and the glusterfs-server sub-package will not be created. Change-Id: I97f5ccf9f2c76e60d9af83915fc59fae57ad6d25 BUG: 1074947 Signed-off-by: Niels de Vos <ndevos@redhat.com> 
With Gluster 4.0 we will not provide the server components for EL6 and
older. At one point Gluster 4.x will get GlusterD2, which requires
Golang tools in the distribution. EL6 does not contain these at the
moment.

With this change, it is possible to `./configure --without-server` which
prevents building glusterd and the xlators for the bricks. Building RPMs
can pass `--without server` and the glusterfs-server sub-package will
not be created.

Change-Id: I97f5ccf9f2c76e60d9af83915fc59fae57ad6d25
BUG: 1074947
Signed-off-by: Niels de Vos <ndevos@redhat.com>
dentry fop serializer: added new server side xlator for dentry fop serialization 2018-01-24T05:39:44+00:00 Sakshi Bansal sabansal@redhat.com 2018-01-22T09:08:17+00:00 78868033bc208bdb681266d0129e66f5627295a2 Problems addressed by this xlator : [1]. To prevent race between parallel mkdir,mkdir and lookup etc. Fops like mkdir/create, lookup, rename, unlink, link that happen on a particular dentry must be serialized to ensure atomicity. Another possible case can be a fresh lookup to find existance of a path whose gfid is not set yet. Further, storage/posix employs a ctime based heuristic 'is_fresh_file' (interval time is less than 1 second of current time) to check fresh-ness of file. With serialization of these two fops (lookup & mkdir), we eliminate the race altogether. [2]. Staleness of dentries This causes exponential increase in traversal time for any inode in the subtree of the directory pointed by stale dentry. Cause : Stale dentry is created because of following two operations: a. dentry creation due to inode_link, done during operations like lookup, mkdir, create, mknod, symlink, create and b. dentry unlinking due to various operations like rmdir, rename, unlink. The reason is __inode_link uses __is_dentry_cyclic, which explores all possible path to avoid cyclic link formation during inode linkage. __is_dentry_cyclic explores stale-dentry(ies) and its all ancestors which is increases traversing time exponentially. Implementation : To acheive this all fops on dentry must take entry locks before they proceed, once they have acquired locks, they perform the fop and then release the lock. Some documentation from email conversation: [1] http://www.gluster.org/pipermail/gluster-devel/2015-December/047314.html [2] http://www.gluster.org/pipermail/gluster-devel/2015-August/046428.html With this patch, the feature is optional, enable it by running: `gluster volume set $volname features.sdfs enable` Also the feature is tested for a month without issues in the experiemental branch for all the regression. Change-Id: I6e80ba3cabfa6facd5dda63bd482b9bf18b6b79b Fixes: #397 BUG: 1304962 Signed-off-by: Sakshi Bansal <sabansal@redhat.com> Signed-off-by: Amar Tumballi <amarts@redhat.com> Signed-off-by: Sunny Kumar <sunkumar@redhat.com> 
Problems addressed by this xlator :

[1]. To prevent race between parallel mkdir,mkdir and lookup etc.

Fops like mkdir/create, lookup, rename, unlink, link that happen on a
particular dentry must be serialized to ensure atomicity.

Another possible case can be a fresh lookup to find existance of a path
whose gfid is not set yet. Further, storage/posix employs a ctime based
heuristic 'is_fresh_file' (interval time is less than 1 second of current
time) to check fresh-ness of file. With serialization of these two fops
(lookup & mkdir), we eliminate the race altogether.

[2]. Staleness of dentries

This causes exponential increase in traversal time for any inode in the
subtree of the directory pointed by stale dentry.

Cause :  Stale dentry is created because of following two operations:

      a. dentry creation due to inode_link, done during operations like
         lookup, mkdir, create, mknod, symlink, create and
      b. dentry unlinking due to various operations like rmdir, rename,
         unlink.

       The reason is __inode_link uses __is_dentry_cyclic, which explores
       all possible path to avoid cyclic link formation during inode
       linkage. __is_dentry_cyclic explores stale-dentry(ies) and its
       all ancestors which is increases traversing time exponentially.

Implementation : To acheive this all fops on dentry must take entry locks
before they proceed, once they have acquired locks, they perform the fop
and then release the lock.

Some documentation from email conversation:
[1] http://www.gluster.org/pipermail/gluster-devel/2015-December/047314.html

[2] http://www.gluster.org/pipermail/gluster-devel/2015-August/046428.html

With this patch, the feature is optional, enable it by running:

 `gluster volume set $volname features.sdfs enable`

Also the feature is tested for a month without issues in the
experiemental branch for all the regression.

Change-Id: I6e80ba3cabfa6facd5dda63bd482b9bf18b6b79b
Fixes: #397
BUG: 1304962
Signed-off-by: Sakshi Bansal <sabansal@redhat.com>
Signed-off-by: Amar Tumballi <amarts@redhat.com>
Signed-off-by: Sunny Kumar <sunkumar@redhat.com>