libglusterfs: Add new fields to volume_options struct

The new fields are required to enable equivalent volume set and volgen
features, and some more additional features in GD2. GD2 does not use a
hard-coded volume options map like GD1, but builds such by reading the
options tables directly from the xlators.

The new fields being introduced into the volume options struct include
the following,
- op-version - version(s) the option was introduced in
- deprecated - version(s) the option was deprecated in
- flags - flags for the option (settable, client, global, force, doc etc.)
- tags - descriptive tags that apply to this option, can be used to
group options
- validate_fn - custom option validation function

Enums for currently available flags have also been defined. To avoid a
naming clashes, the flag enums in GD1 have been renamed.

Updates #302

Change-Id: Ic7e08aef9e051beb47e8dc17d7f7be211aed308a
Signed-off-by: Kaushal M <kaushal@redhat.com>
Reviewed-on: https://review.gluster.org/18059
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Amar Tumballi <amarts@redhat.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/libglusterfs/src/options.h b/libglusterfs/src/options.h
index 3154dcefc02..1d87e051cb4 100644
--- a/libglusterfs/src/options.h
+++ b/libglusterfs/src/options.h
@@ -44,8 +44,33 @@ typedef enum {
         GF_OPT_VALIDATE_MAX,
 } opt_validate_type_t;
 
+typedef enum {
+        OPT_FLAG_NONE        = 0,
+        OPT_FLAG_SETTABLE    = 1 << 0, /* can be set using volume set */
+        OPT_FLAG_CLIENT_OPT  = 1 << 1, /* affects clients */
+        OPT_FLAG_GLOBAL      = 1 << 2, /* affects all instances of the particular xlator */
+        OPT_FLAG_FORCE       = 1 << 3, /* needs force to be reset */
+        OPT_FLAG_NEVER_RESET = 1 << 4, /* which should not be reset */
+        OPT_FLAG_DOC         = 1 << 5, /* can be shown in volume set help */
+} opt_flags_t;
+
 #define ZR_VOLUME_MAX_NUM_KEY    4
 #define ZR_OPTION_MAX_ARRAY_SIZE 64
+/* The maximum number of releases that an option could be backported to
+ * based on the release schedule as in August 2017 (3), plus one more
+ * Refer comment on volume_options.op_version for more information.
+ */
+#define GF_MAX_RELEASES 4
+
+/* Custom validation functoins for options
+ * TODO: Need to check what sorts of validation is being done, and decide if
+ * passing the volinfo is actually required. If it is, then we should possibly
+ * try a solution in GD2 for this.
+ */
+/* typedef int (*option_validation_fn) (glusterd_volinfo_t *volinfo, dict_t *dict,
+                                       char *key, char *value, char **op_errstr);
+*/
+
 
 /* Each translator should define this structure */
 typedef struct volume_options {
@@ -64,6 +89,34 @@ typedef struct volume_options {
          * happen
          */
         opt_validate_type_t     validate;
+
+        /* The op-version at which this option was introduced.
+         * This is an array to support options that get backported to supported
+         * releases.
+         * Normally, an option introduced for a major release just has a single
+         * entry in the array, with op-version of the major release
+         * For an option that is backported, the op-versions of the all the
+         * releases it was ported to should be added, starting from the newest,
+         * to the oldest.
+         */
+        uint32_t op_version[GF_MAX_RELEASES];
+        /* The op-version at which this option was deprecated.
+         * Follows the same rules as above.
+         */
+        uint32_t deprecated[GF_MAX_RELEASES];
+        /* Additional flags for an option
+         * Check the OPT_FLAG_* enums for available flags
+         */
+        uint32_t flags;
+        /* Tags applicable to this option, which can be used to group similar
+         * options
+         */
+        char *tags[ZR_OPTION_MAX_ARRAY_SIZE];
+        /* A custom validation function if required
+         * TODO: See todo above for option_validation_fn
+         */
+        /* option_validation_fn validate_fn; */
+
 } volume_option_t;