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

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 <ravishankar@redhat.com>
(cherry picked from commit 06453d77d056fbaa393a137ca277a20e38d2f67e)

5 files changed, 7 insertions, 15 deletions

diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c
index fb52b110f51..61f74e98bca 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -6594,7 +6594,7 @@ afr_fav_child_reset_sink_xattrs(void *opaque)
         ret = afr_selfheal_inodelk(heal_frame, this, inode, this->name, 0, 0,
                                    locked_on);
         {
-            if (ret < AFR_SH_MIN_PARTICIPANTS)
+            if (ret < priv->child_count)
                 goto data_unlock;
             ret = __afr_selfheal_data_prepare(
                 heal_frame, this, inode, locked_on, sources, sinks,
@@ -6611,7 +6611,7 @@ afr_fav_child_reset_sink_xattrs(void *opaque)
         ret = afr_selfheal_inodelk(heal_frame, this, inode, this->name,
                                    LLONG_MAX - 1, 0, locked_on);
         {
-            if (ret < AFR_SH_MIN_PARTICIPANTS)
+            if (ret < priv->child_count)
                 goto mdata_unlock;
             ret = __afr_selfheal_metadata_prepare(
                 heal_frame, this, inode, locked_on, sources, sinks,
diff --git a/xlators/cluster/afr/src/afr-self-heal-common.c b/xlators/cluster/afr/src/afr-self-heal-common.c
index 58b5d472968..2b8d0b1e963 100644
--- a/xlators/cluster/afr/src/afr-self-heal-common.c
+++ b/xlators/cluster/afr/src/afr-self-heal-common.c
@@ -1554,7 +1554,6 @@ afr_selfheal_find_direction(call_frame_t *frame, xlator_t *this,
     char *accused = NULL;      /* Accused others without any self-accusal */
     char *pending = NULL;      /* Have pending operations on others */
     char *self_accused = NULL; /* Accused itself */
-    int min_participants = -1;
 
     priv = this->private;
 
@@ -1578,12 +1577,7 @@ afr_selfheal_find_direction(call_frame_t *frame, xlator_t *this,
         }
     }
 
-    if (type == AFR_DATA_TRANSACTION || type == AFR_METADATA_TRANSACTION) {
-        min_participants = priv->child_count;
-    } else {
-        min_participants = AFR_SH_MIN_PARTICIPANTS;
-    }
-    if (afr_success_count(replies, priv->child_count) < min_participants) {
+    if (afr_success_count(replies, priv->child_count) < priv->child_count) {
         /* Treat this just like locks not being acquired */
         return -ENOTCONN;
     }
diff --git a/xlators/cluster/afr/src/afr-self-heal-entry.c b/xlators/cluster/afr/src/afr-self-heal-entry.c
index db4e73f899b..e34524391f2 100644
--- a/xlators/cluster/afr/src/afr-self-heal-entry.c
+++ b/xlators/cluster/afr/src/afr-self-heal-entry.c
@@ -583,7 +583,7 @@ afr_selfheal_entry_dirent(call_frame_t *frame, xlator_t *this, fd_t *fd,
     ret = afr_selfheal_entrylk(frame, this, fd->inode, this->name, NULL,
                                locked_on);
     {
-        if (ret < AFR_SH_MIN_PARTICIPANTS) {
+        if (ret < priv->child_count) {
             gf_msg_debug(this->name, 0,
                          "%s: Skipping "
                          "entry self-heal as only %d sub-volumes "
@@ -972,7 +972,7 @@ __afr_selfheal_entry(call_frame_t *frame, xlator_t *this, fd_t *fd,
     ret = afr_selfheal_entrylk(frame, this, fd->inode, this->name, NULL,
                                data_lock);
     {
-        if (ret < AFR_SH_MIN_PARTICIPANTS) {
+        if (ret < priv->child_count) {
             gf_msg_debug(this->name, 0,
                          "%s: Skipping "
                          "entry self-heal as only %d sub-volumes could "
@@ -1094,7 +1094,7 @@ afr_selfheal_entry(call_frame_t *frame, xlator_t *this, inode_t *inode)
     ret = afr_selfheal_tie_breaker_entrylk(frame, this, inode, priv->sh_domain,
                                            NULL, locked_on);
     {
-        if (ret < AFR_SH_MIN_PARTICIPANTS) {
+        if (ret < priv->child_count) {
             gf_msg_debug(this->name, 0,
                          "%s: Skipping "
                          "entry self-heal as only %d sub-volumes could "
diff --git a/xlators/cluster/afr/src/afr-self-heal-name.c b/xlators/cluster/afr/src/afr-self-heal-name.c
index aa20ad1b835..31319ef4d39 100644
--- a/xlators/cluster/afr/src/afr-self-heal-name.c
+++ b/xlators/cluster/afr/src/afr-self-heal-name.c
@@ -514,7 +514,7 @@ afr_selfheal_name_do(call_frame_t *frame, xlator_t *this, inode_t *parent,
     ret = afr_selfheal_entrylk(frame, this, parent, this->name, bname,
                                locked_on);
     {
-        if (ret < AFR_SH_MIN_PARTICIPANTS) {
+        if (ret < priv->child_count) {
             ret = -ENOTCONN;
             goto unlock;
         }
diff --git a/xlators/cluster/afr/src/afr-self-heal.h b/xlators/cluster/afr/src/afr-self-heal.h
index c756089e51d..c1d5e97b012 100644
--- a/xlators/cluster/afr/src/afr-self-heal.h
+++ b/xlators/cluster/afr/src/afr-self-heal.h
@@ -11,8 +11,6 @@
 #ifndef _AFR_SELFHEAL_H
 #define _AFR_SELFHEAL_H
 
-#define AFR_SH_MIN_PARTICIPANTS 2
-
 /* Perform fop on all UP subvolumes and wait for all callbacks to return */
 
 #define AFR_ONALL(frame, rfn, fop, args...)                                    \