From 998d9b8b5e271f407e1c654c34f45f0db36abc71 Mon Sep 17 00:00:00 2001

From: Mohammed Rafi KC <rkavunga@redhat.com>

Date: Tue, 21 May 2019 17:15:07 +0530

Subject: [PATCH 172/178] ec/fini: Fix race with ec_fini and ec_notify

During a graph cleanup, we first sent a PARENT_DOWN and wait for

a child down to ultimately free the xlator and the graph.

In the ec xlator, we cleanup the threads when we get a PARENT_DOWN event.

But a racing event like CHILD_UP or event xl_op may trigger healing threads

after threads cleanup.

So there is a chance that the threads might access a freed private variabe

Upstream patch: https://review.gluster.org/#/c/glusterfs/+/22758/

>Change-Id: I252d10181bb67b95900c903d479de707a8489532

>fixes: bz#1703948

>Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>

Change-Id: I84a10352d9fb3e68d4147b3791e3af45ab79050e

BUG: 1703434

Signed-off-by: Mohammed Rafi KC <rkavunga@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/172285

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

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

---

 libglusterfs/src/glusterfs/xlator.h |  3 +++

 libglusterfs/src/libglusterfs.sym   |  1 +

 libglusterfs/src/xlator.c           | 21 +++++++++++++++++++++

 xlators/cluster/ec/src/ec-heal.c    |  4 ++++

 xlators/cluster/ec/src/ec-heald.c   |  6 ++++++

 xlators/cluster/ec/src/ec.c         |  3 +++

 6 files changed, 38 insertions(+)

diff --git a/libglusterfs/src/glusterfs/xlator.h b/libglusterfs/src/glusterfs/xlator.h

index 8998976..09e463e 100644

--- a/libglusterfs/src/glusterfs/xlator.h

+++ b/libglusterfs/src/glusterfs/xlator.h

@@ -1092,4 +1092,7 @@ gluster_graph_take_reference(xlator_t *tree);

 gf_boolean_t

 mgmt_is_multiplexed_daemon(char *name);

+

+gf_boolean_t

+xlator_is_cleanup_starting(xlator_t *this);

 #endif /* _XLATOR_H */

diff --git a/libglusterfs/src/libglusterfs.sym b/libglusterfs/src/libglusterfs.sym

index ec474e7..7a2edef 100644

--- a/libglusterfs/src/libglusterfs.sym

+++ b/libglusterfs/src/libglusterfs.sym

@@ -1161,3 +1161,4 @@ glusterfs_process_svc_attach_volfp

 glusterfs_mux_volfile_reconfigure

 glusterfs_process_svc_detach

 mgmt_is_multiplexed_daemon

+xlator_is_cleanup_starting

diff --git a/libglusterfs/src/xlator.c b/libglusterfs/src/xlator.c

index 022c3ed..fbfbbe2 100644

--- a/libglusterfs/src/xlator.c

+++ b/libglusterfs/src/xlator.c

@@ -1486,3 +1486,24 @@ mgmt_is_multiplexed_daemon(char *name)

     }

     return _gf_false;

 }

+

+gf_boolean_t

+xlator_is_cleanup_starting(xlator_t *this)

+{

+    gf_boolean_t cleanup = _gf_false;

+    glusterfs_graph_t *graph = NULL;

+    xlator_t *xl = NULL;

+

+    if (!this)

+        goto out;

+    graph = this->graph;

+

+    if (!graph)

+        goto out;

+

+    xl = graph->first;

+    if (xl && xl->cleanup_starting)

+        cleanup = _gf_true;

+out:

+    return cleanup;

+}

diff --git a/xlators/cluster/ec/src/ec-heal.c b/xlators/cluster/ec/src/ec-heal.c

index 2fa1f11..8844c29 100644

--- a/xlators/cluster/ec/src/ec-heal.c

+++ b/xlators/cluster/ec/src/ec-heal.c

@@ -2855,6 +2855,10 @@ ec_replace_brick_heal_wrap(void *opaque)

         itable = ec->xl->itable;

     else

         goto out;

+

+    if (xlator_is_cleanup_starting(ec->xl))

+        goto out;

+

     ret = ec_replace_heal(ec, itable->root);

 out:

     return ret;

diff --git a/xlators/cluster/ec/src/ec-heald.c b/xlators/cluster/ec/src/ec-heald.c

index edf5e11..91512d7 100644

--- a/xlators/cluster/ec/src/ec-heald.c

+++ b/xlators/cluster/ec/src/ec-heald.c

@@ -444,6 +444,9 @@ unlock:

 int

 ec_shd_full_healer_spawn(xlator_t *this, int subvol)

 {

+    if (xlator_is_cleanup_starting(this))

+        return -1;

+

     return ec_shd_healer_spawn(this, NTH_FULL_HEALER(this, subvol),

                                ec_shd_full_healer);

 }

@@ -451,6 +454,9 @@ ec_shd_full_healer_spawn(xlator_t *this, int subvol)

 int

 ec_shd_index_healer_spawn(xlator_t *this, int subvol)

 {

+    if (xlator_is_cleanup_starting(this))

+        return -1;

+

     return ec_shd_healer_spawn(this, NTH_INDEX_HEALER(this, subvol),

                                ec_shd_index_healer);

 }

diff --git a/xlators/cluster/ec/src/ec.c b/xlators/cluster/ec/src/ec.c

index 264582a..df5912c 100644

--- a/xlators/cluster/ec/src/ec.c

+++ b/xlators/cluster/ec/src/ec.c

@@ -486,6 +486,9 @@ ec_set_up_state(ec_t *ec, uintptr_t index_mask, uintptr_t new_state)

 {

     uintptr_t current_state = 0;

+    if (xlator_is_cleanup_starting(ec->xl))

+        return _gf_false;

+

     if ((ec->xl_notify & index_mask) == 0) {

         ec->xl_notify |= index_mask;

         ec->xl_notify_count++;

-- 

1.8.3.1