glusterfs.git/xlators/cluster/afr/src/afr-common.c, branch v5.13

afr: prevent spurious entry heals leading to gfid split-brain

2020-04-06T04:46:50+00:00

Problem:
In a hyperconverged setup with granular-entry-heal enabled, if a file is
recreated while one of the bricks is down, and an index heal is triggered
(with the brick still down), entry-self heal was doing a spurious heal
with just the 2 good bricks. It was doing a post-op leading to removal
of the filename from .glusterfs/indices/entry-changes as well as
erroneous setting of afr xattrs on the parent. When the brick came up,
the xattrs were cleared, resulting in the renamed file not getting
healed and leading to gfid split-brain and EIO on the mount.

Fix:
Proceed with entry heal only when shd can connect to all bricks of the replica,
just like in data and metadata heal.

fixes: #1103
Change-Id: I916ae26ad1fabf259bc6362da52d433b7223b17e
Signed-off-by: Ravishankar N 
(cherry picked from commit 06453d77d056fbaa393a137ca277a20e38d2f67e)

afr: wake up index healer threads

2020-02-27T07:16:20+00:00

Backport of https://review.gluster.org/#/c/glusterfs/+/23288/

...whenever shd is re-enabled after disabling or there is a change in
`cluster.heal-timeout`, without needing to restart shd or waiting for the
current `cluster.heal-timeout` seconds to expire.

See BZ 1743988 for more details.

Change-Id: Ia5ebd7c8e9f5b54cba3199c141fdd1af2f9b9bfe
fixes: bz#1807431
Reported-by: Glen Kiessling 
Signed-off-by: Ravishankar N

afr/lookup: Pass xattr_req in while doing a selfheal in lookup

2019-09-05T12:43:45+00:00

We were not passing xattr_req when doing a name self heal
as well as a meta data heal. Because of this, some xdata
was missing which causes i/o errors

Backport of>https://review.gluster.org/#/c/glusterfs/+/23024/
>Change-Id: Ibfb1205a7eb0195632dc3820116ffbbb8043545f
>Fixes: bz#1728770
>Signed-off-by: Mohammed Rafi KC 

Change-Id: I740ccdbfcf2667fe4a850c12ecdc4b9eeed08293
Fixes: bz#1749352
Signed-off-by: Mohammed Rafi KC

cluster/afr: Remove local from owners_list on failure of lock-acquisition

2019-05-08T14:07:12+00:00

When eager-lock lock acquisition fails because of say network failures, the
local is not being removed from owners_list, this leads to accumulation of
waiting frames and the application will hang because the waiting frames are
under the assumption that another transaction is in the process of acquiring
lock because owner-list is not empty. Handled this case as well in this patch.
Added asserts to make it easier to find these problems in future.

fixes bz#1699736
Change-Id: I3101393265e9827755725b1f2d94a93d8709e923
Signed-off-by: Pranith Kumar K

cluster/thin-arbiter: Consider thin-arbiter before marking new entry changelog

2019-02-18T14:39:55+00:00

If a fop to create an entry fails on one of the data brick,
we mark the pending changelog on the entry on brick for which
it was successful. This is done as part of post op phase to
make sure that entry gets healed even if it gets renamed to
some other path where its parent was not marked as bad.

As it happens as part of post op, we should consider thin-arbiter
to check if the brick, which was successful, is the good brick or not.
This will avoide split brain and other issues.

>Change-Id: I12686675be98f02f70a5186b3ed748c541514d53
>Signed-off-by: Ashish Pandey 

Change-Id: I12686675be98f02f70a5186b3ed748c541514d53
updates: bz#1672314
Signed-off-by: Ashish Pandey

afr: thin-arbiter 2 domain locking and in-memory state

2018-12-12T14:26:42+00:00

2 domain locking + xattrop for write-txn failures:
--------------------------------------------------
- A post-op wound on TA takes AFR_TA_DOM_NOTIFY range lock and
AFR_TA_DOM_MODIFY full lock, does xattrop on TA and releases
AFR_TA_DOM_MODIFY lock and stores in-memory which brick is bad.

- All further write txn failures are handled based on this in-memory
value without querying the TA.

- When shd heals the files, it does so by requesting full lock on
AFR_TA_DOM_NOTIFY domain. Client uses this as a cue (via upcall),
releases AFR_TA_DOM_NOTIFY range lock and invalidates its in-memory
notion of which brick is bad. The next write txn failure is wound on TA
to again update the in-memory state.

- Any incomplete write txns before the AFR_TA_DOM_NOTIFY upcall release
request is got is completed before the lock is released.

- Any write txns got after the release request are maintained in a ta_waitq.

- After the release is complete, the ta_waitq elements are spliced to a
separate queue which is then processed one by one.

- For fops that come in parallel when the in-memory bad brick is still
unknown, only one is wound to TA on wire. The other ones are maintained
in a ta_onwireq which is then processed after we get the response from
TA.

Change-Id: I32c7b61a61776663601ab0040e2f0767eca1fd64
updates: bz#1648205
Signed-off-by: Ravishankar N 
Signed-off-by: Ashish Pandey

cluster/afr: Use 2 domain locking in SHD for thin-arbiter

2018-11-29T15:33:37+00:00

With this change when SHD starts the index crawl it requests
all the clients to release the AFR_TA_DOM_NOTIFY lock so that
clients will know the in memory state is no more valid and
any new operations needs to query the thin-arbiter if required.

When SHD completes healing all the files without any failure, it
will again take the AFR_TA_DOM_NOTIFY lock and gets the xattrs on
TA to see whether there are any new failures happened by that time.
If there are new failures marked on TA, SHD will start the crawl
immediately to heal those failures as well. If there are no new
failures, then SHD will take the AFR_TA_DOM_MODIFY lock and unsets
the xattrs on TA, so that both the data bricks will be considered
as good there after.

>Change-Id: I037b89a0823648f314580ba0716d877bd5ddb1f1
>fixes: bz#1579788
>Signed-off-by: karthik-us 
(cherry picked from commit 5784a00f997212d34bd52b2303e20c097240d91c)

Change-Id: I037b89a0823648f314580ba0716d877bd5ddb1f1
fixes: bz#1648205

all: fix the format string exceptions

2018-11-09T14:03:02+00:00

Currently, there are possibilities in few places, where a user-controlled
(like filename, program parameter etc) string can be passed as 'fmt' for
printf(), which can lead to segfault, if the user's string contains '%s',
'%d' in it.

While fixing it, makes sense to make the explicit check for such issues
across the codebase, by making the format call properly.

Fixes: CVE-2018-14661

Fixes: bz#1647666
Change-Id: Ib547293f2d9eb618594cbff0df3b9c800e88bde4
Signed-off-by: Amar Tumballi

cluster/afr : Check for UP bricks before starting heal

2018-11-08T19:05:46+00:00

Problem:
Currently for replica volume, even if only one brick is UP
SHD will keep crawling index entries even if it can not
heal anything.

In thin-arbiter volume which is also a replica 2 volume,
this causes inode lock contention which in turn sends
upcall to all the clients to release notify locks, even
if it can not do anything for healing.

This will slow down the client performance and kills the
purpose of keeping in memory information about bad brick.

Solution: Before starting heal or even crawling, check if
sufficient number of children are UP and available to check
and heal entries.

(cherry picked from commit f73b4476b15f9d6d3dc3c8e20c9742aacd857f9f)

Change-Id: I011c9da3b37cae275f791affd56b8f1c1ac9255d
updates: bz#1644645
Signed-off-by: Ashish Pandey

afr/lease: Read child nodes from lease structure

2018-11-08T14:31:00+00:00

For lease operation, we allocate and store child nodes
data in lease structure. Use the same in afr_lease_cbk()
while checking for the quorum.

Change-Id: If1fdd5a0798888afd39ad3df57d96487baf9d1e6
updates: #350
Signed-off-by: Soumya Koduri