cluster/afr: Do not log of split-brain when there isn't one

* Even on errors like ENOENT, AFR logs split-brain after
  read-txn refresh, introduced by commit a07ddd8f.
  This can be a cause of much panic and confusion and needs to be fixed.

* Also fixed this issue in write-txns.

* Fixed afr read txns to log about split-brain only after knowing that
  there is no split-brain choice configured.

* Removed code duplication

* Fixed incorrect passing of error code in afr_write_txn_refresh_done()
  (the function was passing -0 as errno to gf_msg().

Change-Id: I354f454ce5bf0e5f00bc27916eb597367cb7d927
BUG: 1411625
Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com>
Reviewed-on: http://review.gluster.org/16362
Smoke: Gluster Build System <jenkins@build.gluster.org>
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>

3 files changed, 21 insertions, 24 deletions

diff --git a/xlators/cluster/afr/src/afr-read-txn.c b/xlators/cluster/afr/src/afr-read-txn.c
index deb74445a55..7591b128578 100644
--- a/xlators/cluster/afr/src/afr-read-txn.c
+++ b/xlators/cluster/afr/src/afr-read-txn.c
@@ -48,17 +48,6 @@ afr_read_txn_next_subvol (call_frame_t *frame, xlator_t *this)
 	return 0;
 }
 
-#define AFR_READ_TXN_SET_ERROR_AND_GOTO(ret, errnum, index, label) \
-        do {                                                      \
-                local->op_ret = ret;                              \
-                local->op_errno = errnum;                          \
-                read_subvol = index;                              \
-                gf_msg (this->name, GF_LOG_ERROR, EIO, AFR_MSG_SPLIT_BRAIN,\
-                        "Failing %s on gfid %s: split-brain observed.",\
-                        gf_fop_list[local->op], uuid_utoa (inode->gfid));\
-                goto label;                                       \
-        } while (0)
-
 int
 afr_read_txn_refresh_done (call_frame_t *frame, xlator_t *this, int err)
 {
@@ -72,19 +61,16 @@ afr_read_txn_refresh_done (call_frame_t *frame, xlator_t *this, int err)
 	inode = local->inode;
 
         if (err) {
-                local->op_errno = -err;
-                local->op_ret = -1;
                 read_subvol = -1;
-                gf_msg (this->name, GF_LOG_ERROR, EIO, AFR_MSG_SPLIT_BRAIN,
-                        "Failing %s on gfid %s: split-brain observed.",
-                        gf_fop_list[local->op], uuid_utoa (inode->gfid));
                 goto readfn;
         }
 
 	read_subvol = afr_read_subvol_select_by_policy (inode, this,
 							local->readable, NULL);
-	if (read_subvol == -1)
-                AFR_READ_TXN_SET_ERROR_AND_GOTO (-1, EIO, -1, readfn);
+	if (read_subvol == -1) {
+                err = -EIO;
+                goto readfn;
+        }
 
 	if (local->read_attempted[read_subvol]) {
 		afr_read_txn_next_subvol (frame, this);
@@ -99,6 +85,10 @@ readfn:
                 if ((ret == 0) && spb_choice >= 0)
                         read_subvol = spb_choice;
         }
+
+        if (read_subvol == -1) {
+                AFR_SET_ERROR_AND_CHECK_SPLIT_BRAIN (-1, -err);
+        }
 	local->readfn (frame, this, read_subvol);
 
 	return 0;
diff --git a/xlators/cluster/afr/src/afr-transaction.c b/xlators/cluster/afr/src/afr-transaction.c
index 9cfd3bf89ec..cbfddf2009d 100644
--- a/xlators/cluster/afr/src/afr-transaction.c
+++ b/xlators/cluster/afr/src/afr-transaction.c
@@ -2614,14 +2614,9 @@ int
 afr_write_txn_refresh_done (call_frame_t *frame, xlator_t *this, int err)
 {
         afr_local_t   *local           = frame->local;
-        int           ret              = 0;
 
         if (err) {
-                local->op_errno = -err;
-                local->op_ret = -1;
-                gf_msg (this->name, GF_LOG_ERROR, -ret, AFR_MSG_SPLIT_BRAIN,
-                        "Failing %s on gfid %s: split-brain observed.",
-                        gf_fop_list[local->op], uuid_utoa (local->inode->gfid));
+                AFR_SET_ERROR_AND_CHECK_SPLIT_BRAIN(-1, -err);
                 goto fail;
         }
 
diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h
index 642d633f9c4..b38d4d92b58 100644
--- a/xlators/cluster/afr/src/afr.h
+++ b/xlators/cluster/afr/src/afr.h
@@ -53,6 +53,18 @@ typedef int (*afr_compound_cbk_t) (call_frame_t *frame, void *cookie,
 #define AFR_CMP(a1,a2,len) ({int __cmp = 0; int __i; for (__i = 0; __i < len; __i++) if (a1[__i] != a2[__i]) { __cmp = 1; break;} __cmp;})
 #define AFR_IS_ARBITER_BRICK(priv, index) ((priv->arbiter_count == 1) && (index == ARBITER_BRICK_INDEX))
 
+#define AFR_SET_ERROR_AND_CHECK_SPLIT_BRAIN(ret, errnum)                       \
+        do {                                                                   \
+                local->op_ret = ret;                                           \
+                local->op_errno = errnum;                                      \
+                if (local->op_errno == EIO)                                    \
+                        gf_msg (this->name, GF_LOG_ERROR, local->op_errno,     \
+                                AFR_MSG_SPLIT_BRAIN, "Failing %s on gfid %s: " \
+                                "split-brain observed.",                       \
+                                gf_fop_list[local->op],                        \
+                                uuid_utoa (local->inode->gfid));               \
+        } while (0)
+
 typedef enum {
         AFR_FAV_CHILD_NONE,
         AFR_FAV_CHILD_BY_SIZE,