glusterfs.git/xlators/cluster/dht/src/dht-common.h, branch v3.12.13

cluster/dht: Remove EIO from dht_inode_missing

2018-07-04T04:02:48+00:00

Removed EIO from the list of errnos that triggered
a migrate check task.

(cherry picked from commit c925962b91c67c8cd2391df7dd0251e0cbf66648)

Change-Id: I7f89c7a16056421588f1af2377cebe6affddcb47
BUG: 1579673
Signed-off-by: N Balachandran

cluster/dht: Fixed leak in dht_populate_inode_for_dentry

2018-02-07T06:24:57+00:00

Fixed an issue in dht_populate_inode_for_dentry where a layout is
set in the inode without checking if it is already set. This overwrites
the value each time without freeing the already existing layout.

Also includes the changes in https://review.gluster.org/19471

> Change-Id: I651bf539a0b82b4ddc4c355890c16a8e91f5f1fd
> BUG: 1541264
> Signed-off-by: N Balachandran 

Change-Id: I651bf539a0b82b4ddc4c355890c16a8e91f5f1fd
BUG: 1541267
Signed-off-by: N Balachandran

cluster/dht: Add migration checks to dht_(f)xattrop

2018-02-06T07:06:47+00:00

The dht_(f)xattrop implementation did not implement
migration phase1/phase2 checks which could cause issues
with rebalance on sharded volumes.
This does not solve the issue where fops may reach the target
out of order.

> Change-Id: I2416fc35115e60659e35b4b717fd51f20746586c
> BUG: 1471031
> Signed-off-by: N Balachandran 

Change-Id: I2416fc35115e60659e35b4b717fd51f20746586c
BUG: 1540224
Signed-off-by: N Balachandran

cluster/dht: make rebalance use truncate incase

2017-11-23T09:46:16+00:00

..
the brick file system does not support fallocate.

> Change-Id: Id76cda2d8bb3b223b779e5e7a34f17c8bfa6283c
> BUG: 1488103
> Signed-off-by: Susant Palai 

Change-Id: Id76cda2d8bb3b223b779e5e7a34f17c8bfa6283c
BUG: 1516691
Signed-off-by: Susant Palai

cluster/dht: Don't store the entire uuid for subvols

2017-10-12T18:25:29+00:00

Comparing the uuid string of the local node against that stored in the
local_subvol information is inefficient, especially as it is
done for every file to be migrated. The code has now been changed
to set the value of info to 1 if the nodeuuid is that of the node
making the comparison so this becomes an integer comparison.

> BUG: 1451434
> Signed-off-by: N Balachandran 
> https://review.gluster.org/#/c/17851

(cherry picked from commit c4a608799a577a4f38139f6bb8a47da8efb0fec3)
Change-Id: I7491d59caad3b71dbf5facc94dcde0cd53962775
BUG: 1500472
Signed-off-by: N Balachandran

cluster/dht: EBADF handling for fremovexattr and fsetxattr

2017-08-12T13:37:31+00:00

Add EBADF handling for dht_fremovexattr and dht_fsetxattr.

> BUG: 1476665
> Signed-off-by: N Balachandran 
> Reviewed-on: https://review.gluster.org/17999
> Smoke: Gluster Build System 
> Reviewed-by: Shyamsundar Ranganathan 
> CentOS-regression: Gluster Build System 
> Reviewed-by: Raghavendra G 
(cherry picked from commit 747a08d34e2a1e94d7fce68a3577370288bb1955)
Change-Id: Ide0d5812dae79655d2565157e5baabcd753b4309
BUG: 1479303
Signed-off-by: N Balachandran 
Reviewed-on: https://review.gluster.org/18012
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Shyamsundar Ranganathan

cluster/dht: Check for open fd only on EBADF

2017-08-09T11:29:50+00:00

DHT fd based fops used to check if the fd was open
on the cached subvol before winding the call. However,
this introduced a performance regression of about
30% for reads.

This check was introduced to handle cases where files
were migrated while IOs were happening. As this is not
the common case, dht will now check if the fd is
open on the cached subvol only if the call fails
with EBADF.

This will prevent a performance hit where a rebalance
is not running.

> BUG: 1476665
> Signed-off-by: N Balachandran 
> Reviewed-on: https://review.gluster.org/17976
> Smoke: Gluster Build System 
> CentOS-regression: Gluster Build System 
> Reviewed-by: Amar Tumballi 
> Reviewed-by: Susant Palai 
> Reviewed-by: Raghavendra G 

(cherry picked from commit cdca1cb26a0aba390c6d8485c0d6d95e22ffc8bd)
Change-Id: I2035a858d63c3fcd22bb634055bbb0ad01686808
BUG: 1479303
Signed-off-by: N Balachandran 
Reviewed-on: https://review.gluster.org/17995
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Shyamsundar Ranganathan

cluster/rebalance: Fix hardlink migration failures

2017-07-13T05:38:40+00:00

A brief about how hardlink migration works:
  - Different hardlinks (to the same file) may hash to different bricks,
but their cached subvol will be same. Rebalance picks up the first hardlink,
calculates it's  hash(call it TARGET) and set the hashed subvolume as an xattr
on the data file.
  - Now all the hardlinks those come after this will fetch that xattr and will
create linkto files on TARGET (all linkto files for the hardlinks will be hardlink
to each other on TARGET).
  - When number of hardlinks on source is equal to the number of hardlinks on
TARGET, the data migration will happen.

RACE:1
  Since rebalance is multi-threaded, the first lookup (which decides where the TARGET
subvol should be), can be called by two hardlink migration parallely and they may end
up creating linkto files on two different TARGET subvols. Hence, hardlinks won't be
migrated.

Fix: Rely on the xattr response of lookup inside gf_defrag_handle_hardlink since it
is executed under synclock.

RACE:2
  The linkto files on TARGET can be created by other clients also if they are doing
lookup on the hardlinks.  Consider a scenario where you have 100 hardlinks.  When
rebalance is migrating 99th hardlink, as a result of continuous lookups from other
client, linkcount on TARGET is equal to source linkcount. Rebalance will migrate data
on the 99th hardlink itself. On 100th hardlink migration, hardlink will have TARGET as
cached subvolume. If it's hash is also the same, then a migration will be triggered from
TARGET to TARGET leading to data loss.

Fix: Make sure before the final data migration, source is not same as destination.

RACE:3
  Since a hardlink can be migrating to a non-hashed subvolume, a lookup from other
client or even the rebalance it self, might delete the linkto file on TARGET leading
to hardlinks never getting migrated.

This will be addressed in a different patch in future.

Change-Id: If0f6852f0e662384ee3875a2ac9d19ac4a6cea98
BUG: 1469964
Signed-off-by: Susant Palai 
Reviewed-on: https://review.gluster.org/17755
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: N Balachandran 
Reviewed-by: Raghavendra G

cluster/dht: Use size to calculate estimates

2017-07-10T14:35:34+00:00

The earlier approach of using the number of files
to determine when the rebalance would complete did
not work well when file sizes differed widely.

The new approach now gets the total data size and
uses that information to determine how long
the rebalance is expected to take.

Change-Id: I84e80a0893efab72ff06130e4596fa71c9c8c868
BUG: 1467209
Signed-off-by: N Balachandran 
Reviewed-on: https://review.gluster.org/17668
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: MOHIT AGRAWAL 
Reviewed-by: Raghavendra G

cluster/dht: Check if fd is opened on dst subvol

2017-06-28T11:42:21+00:00

If an fd is opened on a file, the file is migrated
and the cached subvol is updated in the inode_ctx
before an fd based fop is sent, the fop is sent to
the dst subvol on which the fd is not opened.
This causes the FOP to fail with EBADF.

Now, every fd based fop will check to see that the fd
has been opened on the dst subvol before winding it down.

Change-Id: Id92ef5eb7a5b5226688e2d2868b15e383f5f240e
BUG: 1465075
Signed-off-by: N Balachandran 
Reviewed-on: https://review.gluster.org/17630
Smoke: Gluster Build System 
Reviewed-by: Raghavendra G 
Reviewed-by: Susant Palai 
CentOS-regression: Gluster Build System