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: bz#1804591
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 ec7e6456012..4bfaef9e86c 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -6681,7 +6681,7 @@ 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,
@@ -6698,7 +6698,7 @@ 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 fc00793322c..0341e4a0be0 100644
--- a/xlators/cluster/afr/src/afr-self-heal-common.c
+++ b/xlators/cluster/afr/src/afr-self-heal-common.c
@@ -1575,7 +1575,6 @@ 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;
 
@@ -1599,12 +1598,7 @@ 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 3ce882e8c4a..40be8988648 100644
--- a/xlators/cluster/afr/src/afr-self-heal-entry.c
+++ b/xlators/cluster/afr/src/afr-self-heal-entry.c
@@ -597,7 +597,7 @@ 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 "
@@ -991,7 +991,7 @@ __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 "
@@ -1115,7 +1115,7 @@ 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 36640b5456b..7d4f2080ec3 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 e0dfd7bdfb2..4190a46bd17 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...)                                    \