cluster/dht: Added logging of new layout for dir-selfheal

Added a log which logs the new layout which will be used
for the directory self healing

It prints:

a) Subvolume name
b) Error --> Is needed because layout healing depends on
             the error and having it in log will help in
             debugging
c) Start     Starting of the layout range
d) Stop      Ending of the layout range

Change-Id: I48c9c697716a899165ed29b737362a75c62e09b3
BUG: 1113066
Signed-off-by: Venkatesh Somyajulu <vsomyaju@redhat.com>
Reviewed-on: http://review.gluster.org/8173
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

4 files changed, 125 insertions, 1 deletions

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index 45450d5f383..d50b818cb16 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -5592,3 +5592,107 @@ dht_inode_ctx_layout_get (inode_t *inode, xlator_t *this, dht_layout_t **layout)
 
         return ret;
 }
+
+void
+dht_log_new_layout_for_dir_selfheal (xlator_t *this, loc_t *loc,
+                                 dht_layout_t *layout)
+{
+
+        char                    string[2048] = {0};
+        char                  *output_string = NULL;
+        int                              len = 0;
+        int                              off = 0;
+        int                                i = 0;
+        gf_loglevel_t             log_level = gf_log_get_loglevel();
+        int                              ret = 0;
+        int                   max_string_len = 0;
+
+        if (log_level < GF_LOG_INFO)
+                return;
+
+        if (!layout)
+                return;
+
+        if (!layout->cnt)
+                return;
+
+        if (!loc)
+                return;
+
+        if (!loc->path)
+                return;
+
+        max_string_len = sizeof (string);
+
+        ret = snprintf (string, max_string_len, "Setting layout of %s with ",
+                        loc->path);
+
+        if (ret < 0)
+                return;
+
+        len += ret;
+
+       /* Calculation  of total length of the string required to calloc
+        * output_string. Log includes subvolume-name, start-range, end-range and
+        * err value.
+        *
+        * This log will help to debug cases where:
+        * a) Different processes set different layout of a directory.
+        * b) Error captured in lookup, which will be filled in layout->err
+        * (like ENOENT, ESTALE etc)
+        */
+
+        for (i = 0; i < layout->cnt; i++) {
+
+                ret  = snprintf (string, max_string_len,
+                                 "[Subvol_name: %s, Err: %d , Start: "
+                                 "%"PRIu32 " , Stop: %"PRIu32 " ], ",
+                                 layout->list[i].xlator->name,
+                                 layout->list[i].err, layout->list[i].start,
+                                 layout->list[i].stop);
+
+                if (ret < 0)
+                        return;
+
+                len += ret;
+
+        }
+
+        len++;
+
+        output_string = GF_CALLOC (len, sizeof (char), gf_common_mt_char);
+
+        if (!output_string)
+                return;
+
+        ret = snprintf (output_string, len, "Setting layout of %s with ",
+                        loc->path);
+
+        if (ret < 0)
+                goto err;
+
+        off += ret;
+
+
+        for (i = 0; i < layout->cnt; i++) {
+
+                ret  =  snprintf (output_string + off, len - off,
+                                  "[Subvol_name: %s, Err: %d , Start: "
+                                  "%"PRIu32 " , Stop: %"PRIu32 " ], ",
+                                  layout->list[i].xlator->name,
+                                  layout->list[i].err, layout->list[i].start,
+                                  layout->list[i].stop);
+
+                if (ret < 0)
+                        goto err;
+
+                off += ret;
+
+        }
+
+        gf_msg (this->name, GF_LOG_INFO, 0, DHT_MSG_LOG_FIXED_LAYOUT,
+                "%s", output_string);
+
+err:
+        GF_FREE (output_string);
+}
diff --git a/xlators/cluster/dht/src/dht-common.h b/xlators/cluster/dht/src/dht-common.h
index e45418a73f6..5dee622a2a1 100644
--- a/xlators/cluster/dht/src/dht-common.h
+++ b/xlators/cluster/dht/src/dht-common.h
@@ -807,4 +807,7 @@ dht_inode_ctx_get1 (xlator_t *this, inode_t *inode, xlator_t **subvol);
 int
 dht_subvol_status (dht_conf_t *conf, xlator_t *subvol);
 
+void
+dht_log_new_layout_for_dir_selfheal (xlator_t *this, loc_t *loc,
+                                     dht_layout_t *layout);
 #endif/* _DHT_H */
diff --git a/xlators/cluster/dht/src/dht-messages.h b/xlators/cluster/dht/src/dht-messages.h
index 7668e91ac99..80b20a61efd 100644
--- a/xlators/cluster/dht/src/dht-messages.h
+++ b/xlators/cluster/dht/src/dht-messages.h
@@ -45,7 +45,7 @@
  */
 
 #define GLFS_DHT_BASE                   GLFS_MSGID_COMP_DHT
-#define GLFS_DHT_NUM_MESSAGES           35
+#define GLFS_DHT_NUM_MESSAGES           36
 #define GLFS_MSGID_END          (GLFS_DHT_BASE + GLFS_DHT_NUM_MESSAGES + 1)
 
 /* Messages with message IDs */
@@ -429,8 +429,17 @@
  * @recommendedaction  None
  *
  */
+
 #define DHT_MSG_LAYOUT_SET_FAILED     (GLFS_DHT_BASE + 35)
 
+/*!
+ * @messageid 109036
+ * @diagnosis Informational message regarding layout range distribution
+ *            for a directory across subvolumes
+ * @recommendedaction None
+ */
+
+#define DHT_MSG_LOG_FIXED_LAYOUT     (GLFS_DHT_BASE + 36)
 
 /*------------*/
 #define glfs_msg_end_x GLFS_MSGID_END, "Invalid: End of messages"
diff --git a/xlators/cluster/dht/src/dht-selfheal.c b/xlators/cluster/dht/src/dht-selfheal.c
index 1e2d7438350..4b64acc8793 100644
--- a/xlators/cluster/dht/src/dht-selfheal.c
+++ b/xlators/cluster/dht/src/dht-selfheal.c
@@ -236,6 +236,8 @@ dht_fix_dir_xattr (call_frame_t *frame, loc_t *loc, dht_layout_t *layout)
 
         local->call_cnt = count = conf->subvolume_cnt;
 
+        dht_log_new_layout_for_dir_selfheal (this, loc, layout);
+
         for (i = 0; i < layout->cnt; i++) {
                 dht_selfheal_dir_xattr_persubvol (frame, loc, layout, i, NULL);
 
@@ -306,6 +308,9 @@ dht_selfheal_dir_xattr (call_frame_t *frame, loc_t *loc, dht_layout_t *layout)
         }
 
         local->call_cnt = missing_xattr;
+
+        dht_log_new_layout_for_dir_selfheal (this, loc, layout);
+
         for (i = 0; i < layout->cnt; i++) {
                 if (layout->list[i].err != -1 || !layout->list[i].stop)
                         continue;
@@ -430,6 +435,9 @@ dht_selfheal_dir_xattr_for_nameless_lookup (call_frame_t *frame, loc_t *loc,
         }
 
         local->call_cnt = missing_xattr;
+
+        dht_log_new_layout_for_dir_selfheal (this, loc, layout);
+
         for (i = 0; i < layout->cnt; i++) {
                 if (layout->list[i].err != -1 || !layout->list[i].stop)
                         continue;