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, 53 insertions, 4 deletions

diff --git a/cli/src/cli-cmd-parser.c b/cli/src/cli-cmd-parser.c
index 7c6e3176dc6..d855dbf8a0a 100644
--- a/cli/src/cli-cmd-parser.c
+++ b/cli/src/cli-cmd-parser.c
@@ -197,7 +197,8 @@ cli_cmd_volume_create_parse (const char **words, int wordcount, dict_t **options
                                        "end-volume", "all", "volume_not_in_ring",
                                        "description", "force",
                                        "snap-max-hard-limit",
-                                       "snap-max-soft-limit", NULL};
+                                       "snap-max-soft-limit", "auto-delete",
+                                       NULL};
         char    *w = NULL;
         int      op_count = 0;
         int32_t  replica_count = 1;
@@ -3612,6 +3613,7 @@ cli_snap_config_parse (const char **words, int wordcount, dict_t *dict,
         int8_t                         config_type         = -1;
         const char                    *question            = NULL;
         unsigned int                    cmdi               = 2;
+        int8_t                         auto_delete         = -1;
         /* cmdi is command index, here cmdi is "2" (gluster snapshot config)*/
 
         GF_ASSERT (words);
@@ -3630,9 +3632,11 @@ cli_snap_config_parse (const char **words, int wordcount, dict_t *dict,
                 goto set;
         }
 
+        /* auto-delete cannot be a volume name */
         /* Check whether the 3rd word is volname */
         if (strcmp (words[cmdi], "snap-max-hard-limit") != 0
-             && strcmp (words[cmdi], "snap-max-soft-limit") != 0) {
+             && strcmp (words[cmdi], "snap-max-soft-limit") != 0
+             && strcmp (words[cmdi], "auto-delete") != 0) {
                 ret = dict_set_str (dict, "volname", (char *)words[cmdi]);
                 if (ret) {
                         gf_log ("cli", GF_LOG_ERROR, "Failed to set volname");
@@ -3690,7 +3694,52 @@ cli_snap_config_parse (const char **words, int wordcount, dict_t *dict,
                         goto out;
                 }
                 soft_limit = 1;
-        } else {
+                goto set;
+        }
+
+        if (hard_limit != 1 && (strcmp(words[cmdi], "auto-delete") == 0)) {
+                if (vol_presence == 1) {
+                        ret = -1;
+                        cli_err ("As of now, auto-delete option cannot be set "
+                                "to volumes");
+                        gf_log ("cli", GF_LOG_ERROR, "auto-delete option "
+                                "cannot be set to volumes");
+                        goto out;
+                }
+
+                if (++cmdi >= wordcount) {
+                        ret = -1;
+                        gf_log ("cli", GF_LOG_ERROR, "Invalid Syntax");
+                        goto out;
+                }
+
+                if ((strcmp (words[cmdi], "enable") == 0) ||
+                    (strcmp (words[cmdi], "disable") == 0)) {
+                        ret = dict_set_str (dict, "auto-delete",
+                                            (char *)words[cmdi]);
+                        if (ret) {
+                                gf_log ("cli", GF_LOG_ERROR, "Failed to set "
+                                        "value of auto-delete in request "
+                                        "dictionary");
+                                goto out;
+                        }
+                        auto_delete = 1;
+                } else {
+                        ret = -1;
+                        cli_err ("Please enter a valid value (enable/disable) "
+                                 "for auto-delete");
+                        gf_log ("cli", GF_LOG_ERROR, "Invalid value for "
+                                "auto-delete");
+                        goto out;
+                }
+
+                if (++cmdi != wordcount) {
+                        ret = -1;
+                        gf_log ("cli", GF_LOG_ERROR, "Invalid Syntax");
+                        goto out;
+                }
+        }
+        else {
                 ret = -1;
                 gf_log ("cli", GF_LOG_ERROR, "Invalid Syntax");
                 goto out;
@@ -3705,7 +3754,7 @@ set:
                 goto out;
         }
 
-        if (config_type == GF_SNAP_CONFIG_TYPE_SET) {
+        if (config_type == GF_SNAP_CONFIG_TYPE_SET && auto_delete != 1) {
                 conf_vals = snap_confopt_vals;
                 if (hard_limit && soft_limit) {
                         question = conf_vals[GF_SNAP_CONFIG_SET_BOTH].question;