glusterfs.git/xlators/cluster/afr/src/afr.h, branch v3.8.12

afr: Avoid resetting event_gen when brick is always down

2017-01-17T10:31:57+00:00

Problem:
__afr_set_in_flight_sb_status(), which resets event_gen to zero, is
called if failed_subvols[i] is non-zero for any brick. But failed_subvols[i]
is true even if the brick was down *before* the transaction started.
Hence say if 1 brick is down in  a replica-3, every writev that comes
will trigger an inode refresh because of this resetting, as seen from
the no. of FSTATs in the profile info in the BZ.

Fix:
Reset event gen only if the brick was previously a valid read child and
the FOP failed on it the first time.

Also `s/afr_inode_read_subvol_reset/afr_inode_event_gen_reset` because
the function only resets event gen and not the data/metadata readable.

> Reviewed-on: http://review.gluster.org/16309
> Smoke: Gluster Build System 
> Reviewed-by: Pranith Kumar Karampuri 
> Tested-by: Pranith Kumar Karampuri 
> NetBSD-regression: NetBSD Build System 
> CentOS-regression: Gluster Build System 
(cherry picked from commit 522640be476a3f97dac932f7046f0643ec0ec2f2)

Change-Id: I603ae646cbde96995c35db77916e2ed80b602a91
BUG: 1412888
Signed-off-by: Ravishankar N 
Reviewed-on: http://review.gluster.org/16386
NetBSD-regression: NetBSD Build System 
Reviewed-by: Krutika Dhananjay 
Reviewed-by: Pranith Kumar Karampuri 
CentOS-regression: Gluster Build System 
Smoke: Gluster Build System

cluster/afr: Do not log of split-brain when there isn't one

2017-01-17T06:22:09+00:00

	Backport of: http://review.gluster.org/16362

* Even on errors like ENOENT, AFR logs split-brain after
  read-txn refresh, introduced by commit a07ddd8f.
  This can be a cause of much panic and confusion and needs to be fixed.

* Also fixed this issue in write-txns.

* Fixed afr read txns to log about split-brain only after knowing that
  there is no split-brain choice configured.

* Removed code duplication

* Fixed incorrect passing of error code in afr_write_txn_refresh_done()
  (the function was passing -0 as errno to gf_msg().

Change-Id: I21ac7f6e31840fe3da2f9eecccc495056ab46ece
BUG: 1412915
Signed-off-by: Krutika Dhananjay 
Reviewed-on: http://review.gluster.org/16393
Smoke: Gluster Build System 
Reviewed-by: Ravishankar N 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Pranith Kumar Karampuri

afr: Ignore event_generation checks post inode refresh for write txns

2017-01-08T11:15:27+00:00

Backport of http://review.gluster.org/#/c/16205/

Before http://review.gluster.org/#/c/16091/, after inode refresh, we
failed read txns in case of EIO or event_generation being zero. For
write transactions, the check was only for EIO. 16091 re-factored the
code to fail both read and write when event_generation=0. This seems to
have caused a regression as explained in the BZ.

This patch restores that behaviour in afr_txn_refresh_done().

Change-Id: Id763ed2d420b6d045d4505893a18959d998c91a3
BUG: 1378547
Signed-off-by: Ravishankar N 
Reviewed-on: http://review.gluster.org/16322
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos 
Smoke: Gluster Build System

cluster/afr: Prevent split-brain when bricks are brought off and on in cyclic order

2016-08-22T10:22:36+00:00

        Backport of: http://review.gluster.org/15080

When the bricks are brought offline and then online in cyclic
order while writes are in progress on a file, thanks to inode
refresh in write txns, AFR will mostly fail the write attempt
when the only good copy is offline. However, there is still a
remote possibility that the file will run into split-brain if
the brick that has the lone good copy goes offline *after* the
inode refresh but *before* the write txn completes (I call it
in-flight split-brain in the patch for ease of reference),
requiring intervention from admin to resolve the split-brain
before the IO can resume normally on the file. To get around this,
the patch does the following things:
i) retains the dirty xattrs on the file
ii) avoids marking the last of the good copies as bad (or accused)
    in case it is the one to go down during the course of a write.
iii) fails that particular write with the appropriate errno.

This way, we still have one good copy left despite the split-brain situation
which when it is back online, will be chosen as source to do the heal.

> Change-Id: I9ca634b026ac830b172bac076437cc3bf1ae7d8a
> BUG: 1363721
> Signed-off-by: Krutika Dhananjay 
> Reviewed-on: http://review.gluster.org/15080
> Tested-by: Pranith Kumar Karampuri 
> Smoke: Gluster Build System 
> CentOS-regression: Gluster Build System 
> Reviewed-by: Ravishankar N 
> Reviewed-by: Oleksandr Natalenko 
> NetBSD-regression: NetBSD Build System 
> Reviewed-by: Pranith Kumar Karampuri 
(cherry picked from commit fcb5b70b1099d0379b40c81f35750df8bb9545a5)

Change-Id: I157f1025aebd6624fa3d412abc69a4ae6f2fe9e0
BUG: 1367272
Signed-off-by: Krutika Dhananjay 
Signed-off-by: Oleksandr Natalenko 
Reviewed-on: http://review.gluster.org/15221
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Smoke: Gluster Build System 
Reviewed-by: Pranith Kumar Karampuri

afr: some coverity fixes

2016-07-28T13:54:49+00:00

Note: This is a backport of http://review.gluster.org/14895.
It contains:
i) fixes that prevent deadlocks (afr-common.c).
ii) fixes over-writing op-errno=ENOMEM with possible other values
(afr-inode-read.c).
iii) prevents doing further operations with a NULL dictionary if
allocation fails (afr-self-heal-data.c).
iv) prevents falsely marking a sink as healed if metadata heal fails
midway(afr-self-heal-metadata.c).
v) other minor fixes.

Considering the above are not trivial fixes, the patch is a good
candidate for merging in 3.8 branch.

Thanks to Krutika for a cleaner way to track inode refs in
afr_set_split_brain_choice().

Change-Id: I2d968d05b815ad764b7e3f8aa9ad95a792b3c1df
BUG: 1360556
Signed-off-by: Ravishankar N 
Reviewed-on: http://review.gluster.org/15018
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Krutika Dhananjay 
Reviewed-by: Pranith Kumar Karampuri

cluster/afr: Unwind with xdata in inode-write fops

2016-06-13T10:22:31+00:00

When there is a failure afr was not unwinding xdata to xlators above.
xdata need not be NULL on failures. So it is important to send it
to parent xlators.

 >Change-Id: Ic36aac10a79fa91121961932dd1920cb1c2c3a4c
 >BUG: 1340623
 >Signed-off-by: Pranith Kumar K 
 >Reviewed-on: http://review.gluster.org/14567
 >Smoke: Gluster Build System 
 >NetBSD-regression: NetBSD Build System 
 >CentOS-regression: Gluster Build System 
 >Reviewed-by: Jeff Darcy 

BUG: 1342178
Change-Id: Idd74d2bc898fe5aef537ab48c1754510030c8825
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/14618
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos

cluster/afr: Unwind xdata_rsp even in case of failures

2016-06-10T15:36:21+00:00

DHT expects GF_PREOP_CHECK_FAILED to be present in xdata_rsp in case of mkdir
failures because of stale layout. But AFR was unwinding null xdata_rsp in case
of failures. This was leading to mkdir failures just after remove-brick. Unwind
the xdata_rsp in case of failures to make sure the response from brick reaches
dht.

 >BUG: 1340623
 >Change-Id: Idd3f7b95730e8ea987b608e892011ff190e181d1
 >Signed-off-by: Pranith Kumar K 
 >Reviewed-on: http://review.gluster.org/14553
 >NetBSD-regression: NetBSD Build System 
 >Reviewed-by: Ravishankar N 
 >Smoke: Gluster Build System 
 >CentOS-regression: Gluster Build System 
 >Reviewed-by: Anuradha Talur 
 >Reviewed-by: Krutika Dhananjay 

BUG: 1342178
Change-Id: Iaacadcad0f76979fb250bd008b8e43f0e7acf642
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/14617
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Krutika Dhananjay 
Reviewed-by: Niels de Vos

afr: Automagic unsplit-brain by [ctime|mtime|size|majority]

2016-05-27T14:56:37+00:00

Backport of http://review.gluster.org/#/c/14026/

Introduce cluster.favorite-child-policy which when enabled with
[ctime|mtime|size|majority], automatically heals files that are in
split-brian.

The majority policy will not pick a source if there is no majority.
The other three policies pick the first brick with a valid reply and
non-zero ctime/mtime/size as source.

Change-Id: I93623a914dce2839957fce87b514050e9d274d4c
BUG: 1339639
Signed-off-by: Ravishankar N 
Reviewed-on: http://review.gluster.org/14535
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
CentOS-regression: Gluster Build System 
Reviewed-by: Pranith Kumar Karampuri

cluster/afr: Refresh inode for inode-write fops in need

2016-05-24T21:42:30+00:00

Problem:
If a named fresh-lookup is done on an loc and the fop fails on one of the
bricks or not sent on one of the bricks, but by the time response comes to afr,
if the brick is up, 'can_interpret' will be set to false in afr_lookup_done(),
this will lead to inode-ctx for that inode to be not set, this can lead to EIO
in case of a transaction as it depends on 'readable' array to be available by
that point.

Fix:
Refresh inode for inode-write fops for the ctx to be set if it is not already
done at the time of named fresh-lookup or if the file is in split-brain where
we need to perform one more refresh before failing the fop to check if the file
is still in split-brain or not.

 >BUG: 1336612
 >Change-Id: I5c50b62c8de06129b8516039f7c252e5008c47a5
 >Signed-off-by: Pranith Kumar K 
 >Reviewed-on: http://review.gluster.org/14368
 >Smoke: Gluster Build System 
 >NetBSD-regression: NetBSD Build System 
 >Reviewed-by: Ravishankar N 
 >CentOS-regression: Gluster Build System 

BUG: 1337822
Change-Id: I0f904ebaa78b99cbb11546e08c9fc1562e9a3eef
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/14449
Smoke: Gluster Build System 
NetBSD-regression: NetBSD Build System 
Reviewed-by: Krutika Dhananjay 
Reviewed-by: Anuradha Talur 
CentOS-regression: Gluster Build System 
Reviewed-by: Niels de Vos

cluster/afr: Entry self-heal performance enhancements

2016-04-30T01:21:56+00:00

Change-Id: I52da41dff5619492b656c2217f4716a6cdadebe0
BUG: 1269461
Signed-off-by: Krutika Dhananjay 
Reviewed-on: http://review.gluster.org/12442
Reviewed-by: Pranith Kumar Karampuri 
NetBSD-regression: NetBSD Build System 
Smoke: Gluster Build System 
CentOS-regression: Gluster Build System