From cb4bf2bb3721e66c28a01be6ffff54a6f8610f0e Mon Sep 17 00:00:00 2001

From: Sanju Rakonde <srakonde@redhat.com>

Date: Tue, 25 Sep 2018 23:36:48 +0530

Subject: [PATCH 386/387] glusterd: make sure that brickinfo->uuid is not null

Problem: After an upgrade from the version where shared-brick-count

option is not present to a version which introduced this option

causes issue at the mount point i.e, size of the volume at mount

point will be reduced by shared-brick-count value times.

Cause: shared-brick-count is equal to the number of bricks that

are sharing the file system. gd_set_shared_brick_count() calculates

the shared-brick-count value based on uuid of the node and fsid of

the brick. https://review.gluster.org/#/c/glusterfs/+/19484 handles

setting of fsid properly during an upgrade path. This patch assumed

that when the code path is reached, brickinfo->uuid is non-null.

But brickinfo->uuid is null for all the bricks, as the uuid is null

https://review.gluster.org/#/c/glusterfs/+/19484 couldn't reached the

code path to set the fsid for bricks. So, we had fsid as 0 for all

bricks, which resulted in gd_set_shared_brick_count() to calculate

shared-brick-count in a wrong way. i.e, the logic written in

gd_set_shared_brick_count() didn't work as expected since fsid is 0.

Solution: Before control reaches the code path written by

https://review.gluster.org/#/c/glusterfs/+/19484,

adding a check for whether brickinfo->uuid is null and

if brickinfo->uuid is having null value, calling

glusterd_resolve_brick will set the brickinfo->uuid to a

proper value. When we have proper uuid, fsid for the bricks

will be set properly and shared-brick-count value will be

caluculated correctly.

Please take a look at the bug https://bugzilla.redhat.com/show_bug.cgi?id=1632889

for complete RCA

Steps followed to test the fix:

1. Created a 2 node cluster, the cluster is running with binary

which doesn't have shared-brick-count option

2. Created a 2x(2+1) volume and started it

3. Mouted the volume, checked size of volume using df

4. Upgrade to a version where shared-brick-count is introduced

(upgraded the nodes one by one i.e, stop the glusterd, upgrade the node

and start the glusterd).

5. after upgrading both the nodes, bumped up the cluster.op-version

6. At mount point, df shows the correct size for volume.

updtream patch: https://review.gluster.org/#/c/glusterfs/+/21278/

> fixes: bz#1632889

> Change-Id: Ib9f078aafb15e899a01086eae113270657ea916b

> Signed-off-by: Sanju Rakonde <srakonde@redhat.com>

Change-Id: Ib9f078aafb15e899a01086eae113270657ea916b

BUG: 1630997

Signed-off-by: Sanju Rakonde <srakonde@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/151321

Tested-by: RHGS Build Bot <nigelb@redhat.com>

Reviewed-by: Atin Mukherjee <amukherj@redhat.com>

---

 xlators/mgmt/glusterd/src/glusterd-store.c | 3 ++-

 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xlators/mgmt/glusterd/src/glusterd-store.c b/xlators/mgmt/glusterd/src/glusterd-store.c

index 387e7e5..015f6c2 100644

--- a/xlators/mgmt/glusterd/src/glusterd-store.c

+++ b/xlators/mgmt/glusterd/src/glusterd-store.c

@@ -2609,6 +2609,8 @@ glusterd_store_retrieve_bricks (glusterd_volinfo_t *volinfo)

                  * snapshot or snapshot restored volume this would be done post

                  * creating the brick mounts

                  */

+                if (gf_uuid_is_null(brickinfo->uuid))

+                        (void)glusterd_resolve_brick(brickinfo);

                 if (brickinfo->real_path[0] == '\0' && !volinfo->is_snap_volume

                     && gf_uuid_is_null (volinfo->restored_from_snap)) {

                         /* By now if the brick is a local brick then it will be

@@ -2617,7 +2619,6 @@ glusterd_store_retrieve_bricks (glusterd_volinfo_t *volinfo)

                          * with MY_UUID for realpath check. Hence do not handle

                          * error

                          */

-                        (void)glusterd_resolve_brick (brickinfo);

                         if (!gf_uuid_compare(brickinfo->uuid, MY_UUID)) {

                                 if (!realpath (brickinfo->path, abspath)) {

                                         gf_msg (this->name, GF_LOG_CRITICAL,

-- 

1.8.3.1