glusterfs.git/xlators/cluster/ec/src/ec.h, branch v3.6.3beta1

cluster/ec: Handle internal xattr get/set

2015-02-04T11:53:33+00:00

        Backport of http://review.gluster.org/9385

Problem:
Internal xattrs of EC like trusted.ec.size/config/version
can be modified by users and that can lead to misbehavior
in EC.

Fix:
Don't let the user modify the xattrs. Hide these xattrs
in getfattr outputs.

BUG: 1182490
Change-Id: Ie32ebb95ee67cabbb9488951097a517172b45bcf
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/9455
Reviewed-by: Xavier Hernandez 
Tested-by: Gluster Build System 
Reviewed-by: Raghavendra Bhat

ec: Fix self-healing issues.

2014-12-21T16:04:21+00:00

Three problems have been detected:

1. Self healing is executed in background, allowing the fop that
   detected the problem to continue without blocks nor delays.

   While this is quite interesting to avoid unnecessary delays,
   it can cause spurious failures of self-heal because it may
   try to recover a file inside a directory that a previous
   self-heal has not recovered yet, causing the file self-heal
   to fail.

2. When a partial self-heal is being executed on a directory,
   if a full self-heal is attempted, it won't be executed
   because another self-heal is already in process, so the
   directory won't be fully repaired.

3. Information contained in loc's of some fop's is not enough
   to do a complete self-heal.

To solve these problems, I've made some changes:

* Improved ec_loc_from_loc() to add all available information
  to a loc.

* Before healing an entry, it's parent is checked and partially
  healed if necessary to avoid failures.

* All heal requests received for the same inode while another
  self-heal is being processed are queued. When the first heal
  completes, all pending requests are answered using the results
  of the first heal (without full execution), unless the first
  heal was a partial heal. In this case all partial heals are
  answered, and the first full heal is processed normally.

* An special virtual xattr (not physically stored on bricks)
  named 'trusted.ec.heal' has been created to allow synchronous
  self-heal of files.

  Now, the recommended way to heal an entire volume is this:

    find  -d -exec getfattr -h -n trusted.ec.heal {} \;

Some minor changes:

* ec_loc_prepare() has been renamed to ec_loc_update().

* All loc management functions return 0 on success and -1 on
  error.

* Do not delay fop unlocks if heal is needed.

* Added basic ec xattrs initially on create, mkdir and mknod
  fops.

* Some coding style changes

This is a backport of http://review.gluster.org/9072/

Change-Id: I2a5fd9c57349a153710880d6ac4b1fa0c1475985
BUG: 1159484
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/9073
Tested-by: Gluster Build System 
Reviewed-by: Raghavendra Bhat

ec: Change license

2014-12-13T06:06:13+00:00

This is a backport of http://review.gluster.org/9201/

Change-Id: Iae90ade2421898417b53dec0417a610cf306c44b
BUG: 1170515
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/9233
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur 
Reviewed-by: Raghavendra Bhat 
Tested-by: Raghavendra Bhat

ec: Add config information in an xattr

2014-09-24T05:46:58+00:00

To simplify backward compatibility of the ec xlator when some
parameter or the implementation itself is changed, a new xattr
is added to each file with the configuration needed to recover
it.

The new attribute is called 'trusted.ec.config', and it's a 64-bit
value containing the following information:

    8 bits: version of the config information (currently always 0)
    8 bits: algorithm used to encode the file (currently always 0)
    8 bits: size of the galois field (currently always 8)
    8 bits: number of bricks
    8 bits: redundancy
   24 bits: chunk size (currently 512)

This new xattr could allow, in a future version, to have different
configurations per file.

This is a backport of http://review.gluster.org/8770/

Change-Id: I8c12d40ff546cc201fc66caa367484be3d48aeb4
BUG: 1140862
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/8825
Reviewed-by: Dan Lambright 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

ec: Optimize read/write performance

2014-09-16T17:14:28+00:00

This patch significantly improves performance of read/write
operations on a dispersed volume by reusing previous inodelk/
entrylk operations on the same inode/entry. This reduces the
latency of each individual operation considerably.

Inode version and size are also updated when needed instead
of on each request. This gives an additional boost.

This is a backport of http://review.gluster.org/8369/

Change-Id: I4b98d5508c86b53032e16e295f72a3f83fd8fcac
BUG: 1140844
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/8746
Tested-by: Gluster Build System 
Reviewed-by: Jeff Darcy 
Reviewed-by: Dan Lambright

cluster/ec: Added erasure code translator

2014-07-11T17:33:40+00:00

Change-Id: I293917501d5c2ca4cdc6303df30cf0b568cea361
BUG: 1118629
Signed-off-by: Xavier Hernandez 
Reviewed-on: http://review.gluster.org/7749
Reviewed-by: Krishnan Parthasarathi 
Reviewed-by: Jeff Darcy 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur