glusterd/snapshot : Provide enable/disable option for snapshot auto-delete feature.

This patch provides an interface to enable or disable
the auto-delete feature.
Syntax : gluster snapshot config auto-delete <enable/disable>

DETAILS :

1) When auto-delete feature is disabled, If the the soft-limit is
reached then user is given a warning about exceeding soft-limit
along with successful snapshot creation message (oldest snapshot is
not deleted). And upon reaching hard-limit further snapshot creation
is not allowed.

Example :
------------------------------------------------------------------
|Case - 1: Upon reaching soft-limit
|
|Snapshot create : snap successfully created.
|Warning : soft-limit of volume (vol) is reached. Snapshot creation
|is not possible once hard-limit is reached.
|
|-----------------------------------------------------
|Case - 2: Upon reaching hard-limit
|
|Snapshot create : snap creation failed.
|Error : hard-limit of volume (vol) is reached, Hence it is not
|possible to take further snapshots. Please delete few snapshots
|of the volume (vol) before taking another snapshot.
------------------------------------------------------------------

2) When auto-delete feature is enabled, then as soon as the soft-limit
is reached the oldest snapshot is deleted for every successful snapshot
creation (same as existing method), With this it is made sure that
number of snapshot created is not more than snap-max-hard-limit.

Change-Id: Ie3ca64bbd2c763371f541cd2e378314e73b695b4
BUG: 1105415
Signed-off-by: Sachin Pandit <spandit@redhat.com>
Reviewed-on: http://review.gluster.org/8017
Tested-by: Justin Clift <justin@gluster.org>
Reviewed-by: Rajesh Joseph <rjoseph@redhat.com>
Reviewed-by: Krishnan Parthasarathi <kparthas@redhat.com>
Tested-by: Krishnan Parthasarathi <kparthas@redhat.com>
Reviewed-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 35 insertions, 2 deletions

diff --git a/cli/src/cli-rpc-ops.c b/cli/src/cli-rpc-ops.c
index b998fff3f4c..348fbe4e2e5 100644
--- a/cli/src/cli-rpc-ops.c
+++ b/cli/src/cli-rpc-ops.c
@@ -7682,6 +7682,7 @@ cli_snapshot_config_display (dict_t *dict, gf_cli_rsp *rsp)
         uint64_t            soft_limit           = 0;
         uint64_t            i                    = 0;
         uint64_t            voldisplaycount      = 0;
+        char               *auto_delete          = NULL;
 
         GF_ASSERT (dict);
         GF_ASSERT (rsp);
@@ -7711,8 +7712,11 @@ cli_snapshot_config_display (dict_t *dict, gf_cli_rsp *rsp)
         /* Ignore the error, as the key specified is optional */
         ret = dict_get_uint64 (dict, "snap-max-soft-limit", &soft_limit);
 
+        ret = dict_get_str (dict, "auto-delete", &auto_delete);
+
         if (!hard_limit && !soft_limit
-                        && config_command != GF_SNAP_CONFIG_DISPLAY) {
+                        && config_command != GF_SNAP_CONFIG_DISPLAY
+                        && !auto_delete) {
                 ret = -1;
                 gf_log(THIS->name, GF_LOG_ERROR,
                        "Could not fetch config-key");
@@ -7733,6 +7737,10 @@ cli_snapshot_config_display (dict_t *dict, gf_cli_rsp *rsp)
                         cli_out ("snapshot config: %s "
                                  "for snap-max-soft-limit set successfully",
                                  volname);
+                } else if (auto_delete) {
+                        cli_out ("snapshot config: %s "
+                                 "auto-delete successfully %sd",
+                                 volname, auto_delete);
                 }
                 break;
 
@@ -7756,9 +7764,11 @@ cli_snapshot_config_display (dict_t *dict, gf_cli_rsp *rsp)
                         ret = -1;
                         goto out;
                 }
-                cli_out ("snap-max-soft-limit : %"PRIu64"%%\n",
+                cli_out ("snap-max-soft-limit : %"PRIu64"%%",
                          soft_limit);
 
+                cli_out ("auto-delete : %s\n", auto_delete);
+
                 cli_out ("Snapshot Volume Configuration:");
 
                 ret = dict_get_uint64 (dict, "voldisplaycount",
@@ -8501,6 +8511,8 @@ gf_cli_snapshot_cbk (struct rpc_req *req, struct iovec *iov,
         int32_t               type                     =  0;
         call_frame_t         *frame                    = NULL;
         gf_boolean_t         snap_driven               = _gf_false;
+        int8_t               soft_limit_flag           = -1;
+        char                 *volname                  = NULL;
 
         if (req->rpc_status == -1) {
                 ret = -1;
@@ -8550,8 +8562,29 @@ gf_cli_snapshot_cbk (struct rpc_req *req, struct iovec *iov,
                                 "Failed to get snap name");
                         goto out;
                 }
+
+                /* TODO : Instead of using volname1 directly use
+                 * volname$i in loop once snapshot of multiple
+                 * volumes are supported
+                 */
+                ret = dict_get_str (dict, "volname1", &volname);
+                if (ret) {
+                        gf_log ("cli", GF_LOG_ERROR,
+                                "Failed to get volume name");
+                        goto out;
+                }
+
                 cli_out ("snapshot create: success: Snap %s created "
                                         "successfully", snap_name);
+
+                ret = dict_get_int8 (dict, "soft-limit-reach",
+                                    &soft_limit_flag);
+                if (soft_limit_flag == 1) {
+                        cli_out ("Warning: Soft-limit of volume (%s) is "
+                                "reached. Snapshot creation is not possible "
+                                "once hard-limit is reached.", volname);
+                }
+                ret = 0;
                 break;
 
         case GF_SNAP_OPTION_TYPE_RESTORE: