From 9fd966aa6879ac9867381629f82eca24b950d731 Mon Sep 17 00:00:00 2001

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

Date: Sun, 2 Jun 2019 01:36:33 +0530

Subject: [PATCH 175/178] ec/fini: Fix race between xlator cleanup and on going

 async fop

Problem:

While we process a cleanup, there is a chance for a race between

async operations, for example ec_launch_replace_heal. So this can

lead to invalid mem access.

Solution:

Just like we track on going heal fops, we can also track fops like

ec_launch_replace_heal, so that we can decide when to send a

PARENT_DOWN request.

> upstream patch : https://review.gluster.org/#/c/glusterfs/+/22798/

>Change-Id: I055391c5c6c34d58aef7336847f3b570cb831298

>fixes: bz#1703948

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

Change-Id: I055391c5c6c34d58aef7336847f3b570cb831298

BUG: 1714588

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

Reviewed-on: https://code.engineering.redhat.com/gerrit/172801

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

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

---

 xlators/cluster/ec/src/ec-common.c | 10 ++++++++++

 xlators/cluster/ec/src/ec-common.h |  2 ++

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

 xlators/cluster/ec/src/ec-heal.c   | 17 +++++++++++++++--

 xlators/cluster/ec/src/ec-types.h  |  1 +

 xlators/cluster/ec/src/ec.c        | 37 +++++++++++++++++++++++++------------

 6 files changed, 56 insertions(+), 15 deletions(-)

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

index e85aa8b..9cc6395 100644

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

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

@@ -2955,3 +2955,13 @@ ec_manager(ec_fop_data_t *fop, int32_t error)

     __ec_manager(fop, error);

 }

+

+gf_boolean_t

+__ec_is_last_fop(ec_t *ec)

+{

+    if ((list_empty(&ec->pending_fops)) &&

+        (GF_ATOMIC_GET(ec->async_fop_count) == 0)) {

+        return _gf_true;

+    }

+    return _gf_false;

+}

diff --git a/xlators/cluster/ec/src/ec-common.h b/xlators/cluster/ec/src/ec-common.h

index e948342..bf6c97d 100644

--- a/xlators/cluster/ec/src/ec-common.h

+++ b/xlators/cluster/ec/src/ec-common.h

@@ -204,4 +204,6 @@ void

 ec_reset_entry_healing(ec_fop_data_t *fop);

 char *

 ec_msg_str(ec_fop_data_t *fop);

+gf_boolean_t

+__ec_is_last_fop(ec_t *ec);

 #endif /* __EC_COMMON_H__ */

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

index 6ef9340..8d2d9a1 100644

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

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

@@ -202,11 +202,13 @@ ec_handle_last_pending_fop_completion(ec_fop_data_t *fop, gf_boolean_t *notify)

 {

     ec_t *ec = fop->xl->private;

+    *notify = _gf_false;

+

     if (!list_empty(&fop->pending_list)) {

         LOCK(&ec->lock);

         {

             list_del_init(&fop->pending_list);

-            *notify = list_empty(&ec->pending_fops);

+            *notify = __ec_is_last_fop(ec);

         }

         UNLOCK(&ec->lock);

     }

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

index 8844c29..237fea2 100644

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

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

@@ -2814,8 +2814,20 @@ int

 ec_replace_heal_done(int ret, call_frame_t *heal, void *opaque)

 {

     ec_t *ec = opaque;

+    gf_boolean_t last_fop = _gf_false;

+    if (GF_ATOMIC_DEC(ec->async_fop_count) == 0) {

+        LOCK(&ec->lock);

+        {

+            last_fop = __ec_is_last_fop(ec);

+        }

+        UNLOCK(&ec->lock);

+    }

     gf_msg_debug(ec->xl->name, 0, "getxattr on bricks is done ret %d", ret);

+

+    if (last_fop)

+        ec_pending_fops_completed(ec);

+

     return 0;

 }

@@ -2869,14 +2881,15 @@ ec_launch_replace_heal(ec_t *ec)

 {

     int ret = -1;

-    if (!ec)

-        return ret;

     ret = synctask_new(ec->xl->ctx->env, ec_replace_brick_heal_wrap,

                        ec_replace_heal_done, NULL, ec);

+

     if (ret < 0) {

         gf_msg_debug(ec->xl->name, 0, "Heal failed for replace brick ret = %d",

                      ret);

+        ec_replace_heal_done(-1, NULL, ec);

     }

+

     return ret;

 }

diff --git a/xlators/cluster/ec/src/ec-types.h b/xlators/cluster/ec/src/ec-types.h

index 1c295c0..4dbf4a3 100644

--- a/xlators/cluster/ec/src/ec-types.h

+++ b/xlators/cluster/ec/src/ec-types.h

@@ -643,6 +643,7 @@ struct _ec {

     uintptr_t xl_notify;      /* Bit flag representing

                                  notification for bricks. */

     uintptr_t node_mask;

+    gf_atomic_t async_fop_count; /* Number of on going asynchronous fops. */

     xlator_t **xl_list;

     gf_lock_t lock;

     gf_timer_t *timer;

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

index df5912c..f0d58c0 100644

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

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

@@ -355,6 +355,7 @@ ec_notify_cbk(void *data)

     ec_t *ec = data;

     glusterfs_event_t event = GF_EVENT_MAXVAL;

     gf_boolean_t propagate = _gf_false;

+    gf_boolean_t launch_heal = _gf_false;

     LOCK(&ec->lock);

     {

@@ -384,6 +385,11 @@ ec_notify_cbk(void *data)

              * still bricks DOWN, they will be healed when they

              * come up. */

             ec_up(ec->xl, ec);

+

+            if (ec->shd.iamshd && !ec->shutdown) {

+                launch_heal = _gf_true;

+                GF_ATOMIC_INC(ec->async_fop_count);

+            }

         }

         propagate = _gf_true;

@@ -391,13 +397,12 @@ ec_notify_cbk(void *data)

 unlock:

     UNLOCK(&ec->lock);

+    if (launch_heal) {

+        /* We have just brought the volume UP, so we trigger

+         * a self-heal check on the root directory. */

+        ec_launch_replace_heal(ec);

+    }

     if (propagate) {

-        if ((event == GF_EVENT_CHILD_UP) && ec->shd.iamshd) {

-            /* We have just brought the volume UP, so we trigger

-             * a self-heal check on the root directory. */

-            ec_launch_replace_heal(ec);

-        }

-

         default_notify(ec->xl, event, NULL);

     }

 }

@@ -425,7 +430,7 @@ ec_disable_delays(ec_t *ec)

 {

     ec->shutdown = _gf_true;

-    return list_empty(&ec->pending_fops);

+    return __ec_is_last_fop(ec);

 }

 void

@@ -603,7 +608,10 @@ ec_notify(xlator_t *this, int32_t event, void *data, void *data2)

         if (event == GF_EVENT_CHILD_UP) {

             /* We need to trigger a selfheal if a brick changes

              * to UP state. */

-            needs_shd_check = ec_set_up_state(ec, mask, mask);

+            if (ec_set_up_state(ec, mask, mask) && ec->shd.iamshd &&

+                !ec->shutdown) {

+                needs_shd_check = _gf_true;

+            }

         } else if (event == GF_EVENT_CHILD_DOWN) {

             ec_set_up_state(ec, mask, 0);

         }

@@ -633,17 +641,21 @@ ec_notify(xlator_t *this, int32_t event, void *data, void *data2)

             }

         } else {

             propagate = _gf_false;

+            needs_shd_check = _gf_false;

+        }

+

+        if (needs_shd_check) {

+            GF_ATOMIC_INC(ec->async_fop_count);

         }

     }

 unlock:

     UNLOCK(&ec->lock);

 done:

+    if (needs_shd_check) {

+        ec_launch_replace_heal(ec);

+    }

     if (propagate) {

-        if (needs_shd_check && ec->shd.iamshd) {

-            ec_launch_replace_heal(ec);

-        }

-

         error = default_notify(this, event, data);

     }

@@ -705,6 +717,7 @@ init(xlator_t *this)

     ec->xl = this;

     LOCK_INIT(&ec->lock);

+    GF_ATOMIC_INIT(ec->async_fop_count, 0);

     INIT_LIST_HEAD(&ec->pending_fops);

     INIT_LIST_HEAD(&ec->heal_waiting);

     INIT_LIST_HEAD(&ec->healing);

-- 

1.8.3.1