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>

1 files changed, 104 insertions, 0 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);
+}