cluster/afr: Read-dir should wind to the read-child first

Signed-off-by: Pranith Kumar K <pranithk@gluster.com>
Signed-off-by: Anand Avati <avati@gluster.com>

BUG: 2840 (files not getting self-healed when the first child goes down)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2840

1 files changed, 33 insertions, 17 deletions

diff --git a/xlators/cluster/afr/src/afr-dir-read.c b/xlators/cluster/afr/src/afr-dir-read.c
index b2a001a198a..65adc566465 100644
--- a/xlators/cluster/afr/src/afr-dir-read.c
+++ b/xlators/cluster/afr/src/afr-dir-read.c
@@ -522,10 +522,10 @@ afr_readdirp_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         xlator_t **      children    = NULL;
         ino_t            inum        = 0;
         int              call_child  = 0;
+        int              first_call_child  = 0;
         int              ret         = 0;
         gf_dirent_t *    entry       = NULL;
         gf_dirent_t *    tmp         = NULL;
-        int              child_index = -1;
         uint64_t         ctx         = 0;
         afr_fd_ctx_t    *fd_ctx      = NULL;
         off_t            offset      = 0;
@@ -535,7 +535,12 @@ afr_readdirp_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 
         local = frame->local;
 
-        child_index = (long) cookie;
+        first_call_child = (long) cookie;
+        if (local->cont.readdir.last_tried == -1) {
+                call_child = (long) cookie;
+        } else {
+                call_child = local->cont.readdir.last_tried;
+        }
 
         if (priv->strict_readdir) {
                 ret = fd_ctx_get (local->fd, this, &ctx);
@@ -550,13 +555,15 @@ afr_readdirp_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 fd_ctx = (afr_fd_ctx_t *)(long) ctx;
 
                 if (child_went_down (op_ret, op_errno)) {
-                        if (all_tried (child_index, priv->child_count)) {
+                        if ((call_child + 1) % priv->child_count
+                                       == first_call_child) {
                                 gf_log (this->name, GF_LOG_INFO,
                                         "all options tried going out");
                                 goto out;
                         }
 
-                        call_child = ++child_index;
+                        call_child = (call_child + 1) % priv->child_count;
+                        local->cont.readdir.last_tried = call_child;
 
                         gf_log (this->name, GF_LOG_TRACE,
                                 "starting readdir afresh on child %d, offset %"PRId64,
@@ -565,7 +572,7 @@ afr_readdirp_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                         fd_ctx->failed_over = _gf_true;
 
                         STACK_WIND_COOKIE (frame, afr_readdirp_cbk,
-                                           (void *) (long) call_child,
+                                           (void *) (long) first_call_child,
                                            children[call_child],
                                            children[call_child]->fops->readdirp, local->fd,
                                            local->cont.readdir.size, 0);
@@ -576,10 +583,10 @@ afr_readdirp_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         if (op_ret != -1) {
                 list_for_each_entry_safe (entry, tmp, &entries->list, list) {
                         inum = afr_itransform (entry->d_ino, priv->child_count,
-                                               child_index);
+                                               call_child);
                         entry->d_ino = inum;
                         inum  = afr_itransform (entry->d_stat.ia_ino,
-                                                priv->child_count, child_index);
+                                                priv->child_count, call_child);
                         entry->d_stat.ia_ino = inum;
 
                         if ((local->fd->inode == local->fd->inode->table->root)
@@ -611,12 +618,12 @@ afr_readdirp_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                                 gf_log (this->name, GF_LOG_TRACE,
                                         "trying to fetch non-duplicate entries "
                                         "from offset %"PRId64", child %s",
-                                        offset, children[child_index]->name);
+                                        offset, children[call_child]->name);
 
                                 STACK_WIND_COOKIE (frame, afr_readdirp_cbk,
-                                                   (void *) (long) child_index,
-                                                   children[child_index],
-                                                   children[child_index]->fops->readdirp,
+                                                   (void *) (long) first_call_child,
+                                                   children[call_child],
+                                                   children[call_child]->fops->readdirp,
                                                    local->fd, local->cont.readdir.size, offset);
                                 return 0;
                         }
@@ -645,6 +652,7 @@ afr_do_readdir (call_frame_t *frame, xlator_t *this,
         int              ret        = -1;
         int32_t          op_ret     = -1;
         int32_t          op_errno   = 0;
+        int32_t          read_child = -1;
 
         VALIDATE_OR_GOTO (frame, out);
         VALIDATE_OR_GOTO (this, out);
@@ -662,12 +670,20 @@ afr_do_readdir (call_frame_t *frame, xlator_t *this,
 
         frame->local = local;
 
-        call_child = afr_first_up_child (priv);
-        if (call_child == -1) {
-                op_errno = ENOTCONN;
-                gf_log (this->name, GF_LOG_INFO,
-                        "no child is up");
-                goto out;
+        read_child = afr_read_child (this, fd->inode);
+
+        if ((read_child >= 0) && (priv->child_up[read_child])) {
+                call_child = read_child;
+                local->cont.readdir.last_tried = -1;
+        } else {
+                call_child = afr_first_up_child (priv);
+                if (call_child == -1) {
+                        op_errno = ENOTCONN;
+                        gf_log (this->name, GF_LOG_INFO,
+                                "no child is up");
+                        goto out;
+                }
+                local->cont.readdir.last_tried = call_child;
         }
 
         local->fd                  = fd_ref (fd);