glusterfs.git/xlators/cluster/afr/src/afr-self-heal-common.h, branch v4.0dev1

cluster/afr: refactor

2014-03-22T12:25:57+00:00

- Remove client side self-healing completely (opendir, openfd, lookup)
- Re-work readdir-failover to work reliably in case of NFS
- Remove unused/dead lock recovery code
- Consistently use xdata in both calls and callbacks in all FOPs
- Per-inode event generation, used to force inode ctx refresh
- Implement dirty flag support (in place of pending counts)
- Eliminate inode ctx structure, use read subvol bits + event_generation
- Implement inode ctx refreshing based on event generation
- Provide backward compatibility in transactions
- remove unused variables and functions
- make code more consistent in style and pattern
- regularize and clean up inode-write transaction code
- regularize and clean up dir-write transaction code
- regularize and clean up common FOPs
- reorganize transaction framework code
- skip setting xattrs in pending dict if nothing is pending
- re-write self-healing code using syncops
- re-write simpler self-heal-daemon

Change-Id: I1e4080c9796c8a2815c2dab4be3073f389d614a8
BUG: 1021686
Signed-off-by: Anand Avati 
Reviewed-on: http://review.gluster.org/6010
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

cluster/afr: Print self-heal log when self-heal succeeds

2013-07-31T08:41:45+00:00

Change-Id: I95e47e589419dc6a032cbd8ba01964b6c176c2d5
BUG: 927146
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/5408
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

cluster/afr: Refactor inodelk to handle multiple domains

2013-07-04T04:28:11+00:00

- afr_local_copy should not be memduping locked nodes, that would
  mean that lock is taken in self-heal on those nodes even before
  it actually takes the lock. So removed memdup code. Even entry
  lock related copying (lockee info) is also not necessary for
  self-heal functionality, so removing that as well. Since it is
  not local_copy anymore changed its name.

- My editor changed tabs to spaces.

Change-Id: I8dfb92cb8338e9a967c06907a8e29a8404782d61
BUG: 967717
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.org/5099
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

cluster/afr: Allow data/entry self heal for metadata split-brain

2013-07-02T17:25:17+00:00

Problem:
Currently whenever there is metadata split-brain, a variable
sh->op_failed is set to 1 to denote that self heal got failed.
But if we proceed for data self heal, even code-path of data
self heal also relies on the sh->op_failed variable. So if will
check for sh->op_failed variable and will eventually fails to
do data self heal. So needed a mechanism to allow data self heal
even if metadata is in split brain.

Fix:
Some data structure revamp is done in
http://review.gluster.com/#/c/5106/ fix and this patch is
based on the above fix. Now we can store which particular self-heal
got failed i.e GFID_OR_MISSING_ENTRY_SELF_HEAL, METADATA, DATA,
ENTRY. And we can do two types of self heal failure check.
1. Individual type check: We can check which among all four
   (Metadata, Data, Gfid or missing entry, entry self heal)
   got failed.

2. In afr_self_heal_completion_cbk, we need to make check
   based on the fact that if any specific self heal got failed treat
   the complete self heal as failure so that it will populate
   corresponding circular buffer of event history accordingly.

Change-Id: Icb91e513bcc752386fc8a78812405cfabe5cac2d
BUG: 977797
Signed-off-by: Venkatesh Somyajulu 
Reviewed-on: http://review.gluster.org/5253
Reviewed-by: Pranith Kumar Karampuri 
Tested-by: Gluster Build System 
Reviewed-by: Vijay Bellur

cluster/afr: Improvement in logging of self heal completion status

2013-06-14T01:52:10+00:00

Problem:
As the end of the self heal, message logged by
"afr_self_heal_completion_cbk" is inadequate to determine what exactly failed
during the course of afr self heal. It is worth to have knowledge of what all
types of self heal got triggered for an entity and whether the status is success
or failure.

Fix:
At the end of self heal, it will log information about out of 4 types of self
heal (gfid or missing entry self heal, metadata, data and entry self heal),
who all got triggered and who all got failed or successful at the end.

Change-Id: I5360762fbd7d391ac4c6af6706b4835c5801835a
BUG: 968301
Signed-off-by: Venkatesh Somyajulu 
Reviewed-on: http://review.gluster.org/5106
Reviewed-by: Pranith Kumar Karampuri 
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

cluster/afr: added logging of changelog for split-brain in glustershd.log file

2013-02-03T19:48:01+00:00

Change-Id: Iaf119f839cb2113b8f8efb7bf7636d471b6541bf
BUG: 866440
Signed-off-by: Venkatesh Somyajula 
Reviewed-on: http://review.gluster.org/4385
Reviewed-by: Pranith Kumar Karampuri 
Reviewed-by: Jeff Darcy 
Tested-by: Gluster Build System

afr: support self-heal data trylock mechanism

2012-12-04T22:45:06+00:00

Introduce a block flag to support an optional blocking or
non-blocking mode in the self-heal data locking mechanism. All
callers are modified to use blocking mode, which is the current
default behavior (no change in behavior is introduced by this
commit).

BUG: 874045
Change-Id: Ib7ff9984578fa11de4e3b6981508100cdddd37cd
Signed-off-by: Brian Foster 
Reviewed-on: http://review.gluster.org/4257
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

cluster/afr: Perform data self-heal for non regular files

2012-07-25T22:02:39+00:00

RCA:
Data self-heal for non regular files open the files
and then proceeds using that fd. This approach
does not work for symlinks because open on symlink opens
the file resolved by it.

Fix:
If the file is not a regular file then perform self-heal using
loc. It needs to get 'big' lock and then perform lookup to get
changelog then erase data part of chagelog, then unlock.

Test cases:
Automated at
https://github.com/pranithk/gluster-tests/blob/master/afr/special-file-self-heal-test.sh

Change-Id: I924a922f5135872efe2cccf2e712ada082c5689f
BUG: 811317
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.com/3724
Tested-by: Gluster Build System 
Reviewed-by: Jeff Darcy 
Reviewed-by: Anand Avati

cluster/afr: Enforce order in pre/post op

2012-05-19T03:30:30+00:00

The xattrop order in pre/post op on all the subvols
is client-0, client-1... client-n where n is (replica-count - 1).
This order can lead to invalid split-brains if the brick
dies in the middle of xattrops.

Example: transaction completed pre-op, so on all the subvolumes
xattrs have '1' changelog. Now post-op is sent to both the subvols.
On subvol-0 change-log of client-0 is decremented to 0, before
decrementing change-log of client-1 to 0 the brick dies.
This change-log status on subvol-0 gives the meaning that a
change is done on subvol-0 successfully but on subvol-1 it failed.
Which is not what happened.
Changes done when the subvol-0 was down will lead to pending
change-log on subvol-1 for subvol-0. Which is correct.
When the subvol-0 is brought back up, the change-log will be in
split-brain state even when it is not a legitimate split-brain.

If the brick dies in the middle of xattrops it should remain fool.
Pre-op should perform xattrop of the local change-log first and
post-op should perform xattrop of the local change-log last.
In case of optimistic changelogs txn_changelog should be done
last on local if it succeeds, first if it fails.

Change-Id: Ib6eeb20cdc49b0b1fd2f454f25a9c8e08388c6e7
BUG: 765194
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.com/3226
Tested-by: Gluster Build System 
Reviewed-by: Anand Avati

cluster/afr: Perform conservative merge on dir with xattr split-brain

2012-05-19T03:16:40+00:00

Change-Id: I96d59ad239c2c5efee14dd4b01a10a3f565d491e
BUG: 765587
Signed-off-by: Pranith Kumar K 
Reviewed-on: http://review.gluster.com/3091
Tested-by: Gluster Build System 
Reviewed-by: Jeff Darcy 
Reviewed-by: Anand Avati