afr: replace afr_more_important_error with afr_most_important_error

afr_more_important_error() is written to return whether a new errno
should override an existing errno for high-level operations that
could span multiple sub-operations. It specifically prioritizes
ESTALE over EIO over ENOENT, and otherwise defaults to the latest
error passed having priority.

This change preserves current behavior, but rewrites the logic to
return the higher priority error of the existing and new errno. The
purpose of the change is to make the logic a bit more clear and set
the stage for future changes to make the logic flexible based on
context.

BUG: 892730
Change-Id: Id1aa48855dfb0507abc9d1ef22f2259b30472576
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.org/4375
Reviewed-by: Jeff Darcy <jdarcy@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>

3 files changed, 18 insertions, 26 deletions

diff --git a/xlators/cluster/afr/src/afr-common.c b/xlators/cluster/afr/src/afr-common.c
index ee96944f827..ab1d9018c47 100644
--- a/xlators/cluster/afr/src/afr-common.c
+++ b/xlators/cluster/afr/src/afr-common.c
@@ -1638,8 +1638,8 @@ afr_self_heal_lookup_unwind (call_frame_t *frame, xlator_t *this,
 
         if (op_ret == -1) {
                 local->op_ret = -1;
-                if (afr_error_more_important (local->op_errno, op_errno))
-                        local->op_errno = op_errno;
+		local->op_errno = afr_most_important_error(local->op_errno,
+							   op_errno);
 
                 goto out;
         } else {
@@ -1990,25 +1990,19 @@ afr_lookup_done (call_frame_t *frame, xlator_t *this)
  * others in that they must be given higher priority while
  * returning to the user.
  *
- * The hierarchy is ESTALE > ENOENT > others
- *
+ * The hierarchy is ESTALE > EIO > ENOENT > others
  */
-
-gf_boolean_t
-afr_error_more_important (int32_t old_errno, int32_t new_errno)
+int32_t
+afr_most_important_error(int32_t old_errno, int32_t new_errno)
 {
-        gf_boolean_t ret = _gf_true;
+	if (old_errno == ESTALE || new_errno == ESTALE)
+		return ESTALE;
+	if (old_errno == EIO || new_errno == EIO)
+		return EIO;
+	if (old_errno == ENOENT || new_errno == ENOENT)
+		return ENOENT;
 
-        /* Nothing should ever overwrite ESTALE */
-        if (old_errno == ESTALE)
-                ret = _gf_false;
-
-        /* Nothing should overwrite ENOENT, except ESTALE/EIO*/
-        else if ((old_errno == ENOENT) && (new_errno != ESTALE)
-                 && (new_errno != EIO))
-                ret = _gf_false;
-
-        return ret;
+	return new_errno;
 }
 
 int32_t
@@ -2027,8 +2021,8 @@ afr_resultant_errno_get (int32_t *children,
                 } else {
                         child = i;
                 }
-                if (afr_error_more_important (op_errno, child_errno[child]))
-                                op_errno = child_errno[child];
+		op_errno = afr_most_important_error(op_errno,
+						    child_errno[child]);
         }
         return op_errno;
 }
@@ -2040,8 +2034,7 @@ afr_lookup_handle_error (afr_local_t *local, int32_t op_ret,  int32_t op_errno)
         if (op_errno == ENOENT)
                 local->enoent_count++;
 
-        if (afr_error_more_important (local->op_errno, op_errno))
-                local->op_errno = op_errno;
+	local->op_errno = afr_most_important_error(local->op_errno, op_errno);
 
         if (local->op_errno == ESTALE) {
                 local->op_ret = -1;
diff --git a/xlators/cluster/afr/src/afr-self-heal-common.c b/xlators/cluster/afr/src/afr-self-heal-common.c
index b5b42aecb0b..e7026081bda 100644
--- a/xlators/cluster/afr/src/afr-self-heal-common.c
+++ b/xlators/cluster/afr/src/afr-self-heal-common.c
@@ -112,8 +112,7 @@ void
 afr_sh_set_error (afr_self_heal_t *sh, int32_t op_errno)
 {
         sh->op_ret = -1;
-        if (afr_error_more_important (sh->op_errno, op_errno))
-                sh->op_errno = op_errno;
+	sh->op_errno = afr_most_important_error(sh->op_errno, op_errno);
 }
 
 void
diff --git a/xlators/cluster/afr/src/afr.h b/xlators/cluster/afr/src/afr.h
index 475e5dda43d..93bd92f25e7 100644
--- a/xlators/cluster/afr/src/afr.h
+++ b/xlators/cluster/afr/src/afr.h
@@ -953,8 +953,8 @@ afr_children_rm_child (int32_t *children, int32_t child,
                              int32_t child_count);
 void
 afr_reset_children (int32_t *children, int32_t child_count);
-gf_boolean_t
-afr_error_more_important (int32_t old_errno, int32_t new_errno);
+int32_t
+afr_most_important_error(int32_t old_errno, int32_t new_errno);
 int
 afr_errno_count (int32_t *children, int *child_errno,
                  unsigned int child_count, int32_t op_errno);