mgmt/glusterd: perform store on only newly created snapshot

* Instead performing store on all the snaps of the volume when a new snap
  is created, store only the new snap's info. Otherwise with more and more
  snapshots in the volume, time creation for new snapshot becomes very large
  as glusterd has to store all the snapshots related info everytime (that too by
  doing fsyncs)

Change-Id: I0e005d1d4c044b07a8abde8e6ba55e66a1bbd590
BUG: 1059146
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-on: http://review.gluster.org/6841
Reviewed-by: Rajesh Joseph <rjoseph@redhat.com>
Tested-by: Rajesh Joseph <rjoseph@redhat.com>

1 files changed, 99 insertions, 11 deletions

diff --git a/xlators/mgmt/glusterd/src/glusterd-store.c b/xlators/mgmt/glusterd/src/glusterd-store.c
index 84682316d..5dfc96485 100644
--- a/xlators/mgmt/glusterd/src/glusterd-store.c
+++ b/xlators/mgmt/glusterd/src/glusterd-store.c
@@ -1522,20 +1522,108 @@ out:
 }
 
 int32_t
-glusterd_store_perform_snap_store (glusterd_volinfo_t *volinfo)
+glusterd_store_perform_snap_store (glusterd_volinfo_t *volinfo, char *snapname)
 {
-        int                         fd = -1;
-        int32_t                     ret = -1;
-        glusterd_snap_t            *entry = NULL;
-        glusterd_snap_t            *tmp = NULL;
-        uint64_t                    count = 0;
+        int                         fd            = -1;
+        int32_t                     ret           = -1;
+        glusterd_snap_t            *entry         = NULL;
+        glusterd_snap_t            *tmp           = NULL;
+        uint64_t                    count         = 0;
         char                        buf[PATH_MAX] = {0,};
+        xlator_t                   *this          = NULL;
 
         GF_ASSERT (volinfo);
+        GF_ASSERT (snapname);
+
+        this = THIS;
+        GF_ASSERT (this);
 
         ret = glusterd_store_create_snaps_dir (volinfo);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "failed to create the snaps "
+                        "directory for the volume %s (snap: %s)",
+                        volinfo->volname, snapname);
+                goto out;
+        }
+
+        ret = glusterd_store_create_snap_list_sh_on_absence (volinfo);
         if (ret)
                 goto out;
+        fd = gf_store_mkstemp (volinfo->snap_list_shandle);
+        if (fd <= 0) {
+                ret = -1;
+                goto out;
+        }
+
+        LOCK (&volinfo->lock);
+        {
+                list_for_each_entry_safe (entry, tmp, &volinfo->snaps,
+                                          snap_list) {
+                        if (!strcmp (entry->snap_name, snapname)) {
+                                ret = glusterd_store_snap_list_write (fd, entry,
+                                                                      count);
+                                if (ret) {
+                                        gf_log (this->name, GF_LOG_ERROR,
+                                                "Failed to write snap list to"
+                                                " store");
+                                        goto unlock;
+                                }
+                                ret = glusterd_store_snap_volume (volinfo,
+                                                                  entry);
+                                if (ret) {
+                                        gf_log (this->name, GF_LOG_ERROR,
+                                                "Failed to store snap volume");
+                                        goto unlock;
+                                }
+                        }
+                        count++;
+                }
+                GF_ASSERT (count == volinfo->snap_count);
+                snprintf (buf, sizeof(buf), "%"PRIu64, count);
+                ret = gf_store_save_value (fd, GLUSTERD_STORE_KEY_SNAP_COUNT,
+                                           buf);
+                if (ret)
+                        goto unlock;
+        }
+unlock:
+        UNLOCK (&volinfo->lock);
+
+        ret = gf_store_rename_tmppath (volinfo->snap_list_shandle);
+        if (ret)
+                goto out;
+
+out:
+        if (ret && (fd > 0))
+                gf_store_unlink_tmppath (volinfo->snap_list_shandle);
+        if (fd > 0)
+                close (fd);
+
+        gf_log (this->name, GF_LOG_TRACE, "Returning %d", ret);
+        return ret;
+}
+
+int32_t
+glusterd_store_perform_all_snap_store (glusterd_volinfo_t *volinfo)
+{
+        int                         fd            = -1;
+        int32_t                     ret           = -1;
+        glusterd_snap_t            *entry         = NULL;
+        glusterd_snap_t            *tmp           = NULL;
+        uint64_t                    count         = 0;
+        char                        buf[PATH_MAX] = {0,};
+        xlator_t                   *this          = NULL;
+
+        GF_ASSERT (volinfo);
+
+        this = THIS;
+        GF_ASSERT (this);
+
+        ret = glusterd_store_create_snaps_dir (volinfo);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR, "failed to create the snaps "
+                        "directory for the volume %s", volinfo->volname);
+                goto out;
+        }
 
         ret = glusterd_store_create_snap_list_sh_on_absence (volinfo);
         if (ret)
@@ -1552,13 +1640,13 @@ glusterd_store_perform_snap_store (glusterd_volinfo_t *volinfo)
                                           snap_list) {
                         ret = glusterd_store_snap_list_write (fd, entry, count);
                         if (ret) {
-                                gf_log (THIS->name, GF_LOG_ERROR, "Failed to "
+                                gf_log (this->name, GF_LOG_ERROR, "Failed to "
                                         "write snap list to store");
                                 goto unlock;
                         }
                         ret = glusterd_store_snap_volume (volinfo, entry);
                         if (ret) {
-                                gf_log (THIS->name, GF_LOG_ERROR, "Failed to "
+                                gf_log (this->name, GF_LOG_ERROR, "Failed to "
                                         "store snap volume");
                                 goto unlock;
                         }
@@ -1583,7 +1671,7 @@ out:
         if (fd > 0)
                 close (fd);
 
-        gf_log ("", GF_LOG_TRACE, "Returning %d", ret);
+        gf_log (this->name, GF_LOG_TRACE, "Returning %d", ret);
         return ret;
 }
 
@@ -1843,7 +1931,7 @@ glusterd_store_volinfo (glusterd_volinfo_t *volinfo, glusterd_volinfo_ver_ac_t a
         if (ret)
                 goto out;
 
-        ret = glusterd_store_perform_snap_store (volinfo);
+        ret = glusterd_store_perform_all_snap_store (volinfo);
         if (ret)
                 goto out;
 
@@ -3508,7 +3596,7 @@ glusterd_store_retrieve_volumes (xlator_t  *this)
                         ret = glusterd_volinfo_find (entry->d_name, &volinfo);
                         ret =
                         glusterd_store_create_snap_list_sh_on_absence (volinfo);
-                        ret = glusterd_store_perform_snap_store (volinfo);
+                        ret = glusterd_store_perform_all_snap_store (volinfo);
                         //ret = glusterd_store_perform_snap_list_store (volinfo); TODO: Fix this
 
                 }