[dm-devel] [PATCH v2 1/1] add display of map information in JSON format

Christophe Varoqui christophe.varoqui at opensvc.com
Wed May 11 17:35:37 UTC 2016


Hi,

the json choice over xml is fine for me, so I'm ready to merge.

Before I do so, is there a second round of review pending ?

Are wannabe users of this new output happy with some fields being merged
(like vendor/product/rev) ?

Best regards,
Christophe Varoqui
OpenSVC


On Tue, May 10, 2016 at 9:05 PM, Todd Gill <tgill at redhat.com> wrote:

> The patch add these commands:
>
> multipathd show maps json
> multipathd show map $map json
>
> Each command will output the requested map(s) in JSON.
>
> For the "show maps json" command, the patch pre-allocates
> INITIAL_REPLY_LEN * PRINT_JSON_MULTIPLIER(5).  The JSON text
> is about 5x the size of the "show maps topology" text.
>
> Signed-off-by: Todd Gill <tgill at redhat.com>
> ---
>  libmultipath/print.c      | 163
> ++++++++++++++++++++++++++++++++++++++++++++++
>  libmultipath/print.h      |  63 ++++++++++++++++++
>  multipathd/cli.c          |   3 +
>  multipathd/cli.h          |   2 +
>  multipathd/cli_handlers.c |  93 ++++++++++++++++++++++++++
>  multipathd/cli_handlers.h |   2 +
>  multipathd/main.c         |   2 +
>  7 files changed, 328 insertions(+)
>
> diff --git a/libmultipath/print.c b/libmultipath/print.c
> index 7fec6e9..e92b534 100644
> --- a/libmultipath/print.c
> +++ b/libmultipath/print.c
> @@ -1000,6 +1000,169 @@ snprint_multipath_topology (char * buff, int len,
> struct multipath * mpp,
>  }
>
>  static int
> +snprint_json (char * line, int len, int indent, char *json_str)
> +{
> +       int fwd = 0, i;
> +
> +       for (i = 0; i < indent; i++) {
> +               fwd += snprintf(line + fwd, len - fwd, PRINT_JSON_INDENT);
> +               if (fwd > len)
> +                       return fwd;
> +       }
> +
> +       fwd += snprintf(line + fwd, len - fwd, "%s", json_str);
> +       return fwd;
> +}
> +
> +static int
> +snprint_json_header (char * line, int len)
> +{
> +       int fwd = 0;
> +
> +       fwd +=  snprint_json(line + fwd, len, 0, PRINT_JSON_START_ELEM);
> +       if (fwd > len)
> +               return fwd;
> +
> +       fwd +=  snprintf(line + fwd, len  - fwd, PRINT_JSON_START_VERSION,
> +                       PRINT_JSON_MAJOR_VERSION,
> PRINT_JSON_MINOR_VERSION);
> +       return fwd;
> +}
> +
> +static int
> +snprint_json_elem_footer (char * line, int len, int indent, int last)
> +{
> +       int fwd = 0, i;
> +
> +       for (i = 0; i < indent; i++) {
> +               fwd += snprintf(line + fwd, len - fwd, PRINT_JSON_INDENT);
> +               if (fwd > len)
> +                       return fwd;
> +       }
> +
> +       if (last == 1)
> +               fwd += snprintf(line + fwd, len - fwd, "%s",
> +                               PRINT_JSON_END_LAST);
> +       else
> +               fwd += snprintf(line + fwd, len - fwd, "%s",
> +                               PRINT_JSON_END_ELEM);
> +       return fwd;
> +}
> +
> +static int
> +snprint_multipath_fields_json (char * buff, int len,
> +               struct multipath * mpp, int last)
> +{
> +       int i, j, fwd = 0;
> +       struct path *pp;
> +       struct pathgroup *pgp;
> +
> +       fwd += snprint_multipath(buff + fwd, len - fwd, PRINT_JSON_MAP,
> mpp, 0);
> +       if (fwd > len)
> +               return fwd;
> +
> +       fwd += snprint_json(buff + fwd, len - fwd, 2,
> PRINT_JSON_START_GROUPS);
> +       if (fwd > len)
> +               return fwd;
> +
> +       vector_foreach_slot (mpp->pg, pgp, i) {
> +
> +               pgp->selector = mpp->selector;
> +               fwd += snprint_pathgroup(buff + fwd, len - fwd,
> PRINT_JSON_GROUP, pgp);
> +               if (fwd > len)
> +                       return fwd;
> +
> +               fwd += snprint_json(buff + fwd, len - fwd, 3,
> PRINT_JSON_START_PATHS);
> +               if (fwd > len)
> +                       return fwd;
> +
> +               vector_foreach_slot (pgp->paths, pp, j) {
> +
> +                       fwd += snprint_path(buff + fwd,
> +                                       len - fwd, PRINT_JSON_PATH, pp, 0);
> +                       if (fwd > len)
> +                               return fwd;
> +
> +                       fwd += snprint_json_elem_footer(buff + fwd,
> +                                       len - fwd, 3, j + 1 ==
> VECTOR_SIZE(pgp->paths));
> +                       if (fwd > len)
> +                               return fwd;
> +               }
> +
> +               fwd += snprint_json(buff + fwd, len - fwd, 0,
> PRINT_JSON_END_ARRAY);
> +               if (fwd > len)
> +                       return fwd;
> +
> +               fwd +=  snprint_json_elem_footer(buff + fwd,
> +                       len - fwd, 2, i + 1 == VECTOR_SIZE(mpp->pg));
> +               if (fwd > len)
> +                       return fwd;
> +       }
> +
> +       fwd += snprint_json(buff + fwd, len - fwd, 0,
> PRINT_JSON_END_ARRAY);
> +       if (fwd > len)
> +               return fwd;
> +
> +       fwd += snprint_json_elem_footer(buff + fwd, len - fwd, 1, last);
> +       return fwd;
> +}
> +
> +int
> +snprint_multipath_map_json (char * buff, int len,
> +               struct multipath * mpp, int last){
> +       int fwd = 0;
> +
> +       memset(buff, 0, len);
> +       fwd +=  snprint_json_header(buff + fwd, len);
> +       if (fwd > len)
> +               return len;
> +
> +       fwd +=  snprint_json(buff + fwd, len - fwd, 0,
> PRINT_JSON_START_MAP);
> +       if (fwd > len)
> +               return len;
> +
> +       fwd += snprint_multipath_fields_json(buff + fwd, len - fwd, mpp,
> 1);
> +       if (fwd > len)
> +               return len;
> +
> +       fwd +=  snprint_json(buff + fwd, len - fwd, 0,
> "\n"PRINT_JSON_END_LAST);
> +       if (fwd > len)
> +               return len;
> +       return fwd;
> +}
> +
> +int
> +snprint_multipath_topology_json (char * buff, int len, struct vectors *
> vecs)
> +{
> +       int i, fwd = 0;
> +       struct multipath * mpp;
> +
> +       memset(buff, 0, len);
> +       fwd +=  snprint_json_header(buff + fwd, len);
> +       if (fwd > len)
> +               return len;
> +
> +       fwd +=  snprint_json(buff + fwd, len  - fwd, 1,
> PRINT_JSON_START_MAPS);
> +       if (fwd > len)
> +               return len;
> +
> +       vector_foreach_slot(vecs->mpvec, mpp, i) {
> +               fwd += snprint_multipath_fields_json(buff + fwd, len - fwd,
> +                               mpp, i + 1 == VECTOR_SIZE(vecs->mpvec));
> +               if (fwd > len)
> +                       return len;
> +       }
> +
> +       fwd +=  snprint_json(buff + fwd, len - fwd, 0,
> PRINT_JSON_END_ARRAY);
> +       if (fwd > len)
> +               return len;
> +
> +       fwd +=  snprint_json(buff + fwd, len - fwd, 0,
> PRINT_JSON_END_LAST);
> +       if (fwd > len)
> +               return len;
> +       return fwd;
> +}
> +
> +static int
>  snprint_hwentry (char * buff, int len, struct hwentry * hwe)
>  {
>         int i;
> diff --git a/libmultipath/print.h b/libmultipath/print.h
> index 8bd0bbc..f8a383d 100644
> --- a/libmultipath/print.h
> +++ b/libmultipath/print.h
> @@ -7,6 +7,65 @@
>  #define PRINT_MAP_PROPS      "size=%S features='%f' hwhandler='%h' wp=%r"
>  #define PRINT_PG_INDENT      "policy='%s' prio=%p status=%t"
>
> +#define PRINT_JSON_MULTIPLIER     5
> +#define PRINT_JSON_MAJOR_VERSION  0
> +#define PRINT_JSON_MINOR_VERSION  1
> +#define PRINT_JSON_START_VERSION  "   \"major_version \": %d,\n" \
> +                                  "   \"minor_version \": %d,\n"
> +#define PRINT_JSON_START_ELEM     "{\n"
> +#define PRINT_JSON_START_MAP      "   \"map\":"
> +#define PRINT_JSON_START_MAPS     "\"maps\": ["
> +#define PRINT_JSON_START_PATHS    "\"paths\": ["
> +#define PRINT_JSON_START_GROUPS   "\"path_groups\": ["
> +#define PRINT_JSON_END_ELEM       "},"
> +#define PRINT_JSON_END_LAST       "}"
> +#define PRINT_JSON_END_ARRAY      "]\n"
> +#define PRINT_JSON_INDENT    "   "
> +#define PRINT_JSON_MAP       "{\n" \
> +                             "      \"name\" : \"%n\",\n" \
> +                             "      \"uuid\" : \"%w\",\n" \
> +                             "      \"sysfs\" : \"%d\",\n" \
> +                             "      \"failback\" : \"%F\",\n" \
> +                             "      \"queueing\" : \"%Q\",\n" \
> +                             "      \"paths\" : %N,\n" \
> +                             "      \"write_prot\" : \"%r\",\n" \
> +                             "      \"dm-st\" : \"%t\",\n" \
> +                             "      \"size\" : \"%S\",\n" \
> +                             "      \"features\" : \"%f\",\n" \
> +                             "      \"hwhandler\" : \"%h\",\n" \
> +                             "      \"action\" : \"%A\",\n" \
> +                             "      \"path_faults\" : %0,\n" \
> +                             "      \"vend/prod/rev\" : \"%s\",\n" \
> +                             "      \"switch_grp\" : %1,\n" \
> +                             "      \"map_loads\" : %2,\n" \
> +                             "      \"total_q_time\" : %3,\n" \
> +                             "      \"q_timeouts\" : %4,"
> +
> +#define PRINT_JSON_GROUP     "{\n" \
> +                             "         \"selector\" : \"%s\",\n" \
> +                             "         \"pri\" : %p,\n" \
> +                             "         \"dm_st\" : \"%t\","
> +
> +#define PRINT_JSON_PATH      "{\n" \
> +                             "            \"uuid\" : \"%w\",\n" \
> +                             "            \"hcil\" : \"%i\",\n" \
> +                             "            \"dev\" : \"%d\",\n"\
> +                             "            \"dev_t\" : \"%D\",\n" \
> +                             "            \"dm_st\" : \"%t\",\n" \
> +                             "            \"dev_st\" : \"%o\",\n" \
> +                             "            \"chk_st\" : \"%T\",\n" \
> +                             "            \"vend/prod/rev\" : \"%s\",\n" \
> +                             "            \"checker\" : \"%c\",\n" \
> +                             "            \"next_check\" : \"%C\",\n" \
> +                             "            \"pri\" : %p,\n" \
> +                             "            \"size\" : \"%S\",\n" \
> +                             "            \"serial\" : \"%z\",\n" \
> +                             "            \"host WWNN\" : \"%N\",\n" \
> +                             "            \"target WWNN\" : \"%n\",\n" \
> +                             "            \"host WWPN\" : \"%R\",\n" \
> +                             "            \"target WWPN\" : \"%r\",\n" \
> +                             "            \"host adapter\" : \"%a\""
> +
>  #define MAX_LINE_LEN  80
>  #define MAX_LINES     64
>  #define MAX_FIELD_LEN 64
> @@ -41,6 +100,10 @@ int snprint_path (char *, int, char *, struct path *,
> int);
>  int snprint_multipath (char *, int, char *, struct multipath *, int);
>  int snprint_multipath_topology (char *, int, struct multipath * mpp,
>                                 int verbosity);
> +int snprint_multipath_topology_json (char * buff, int len,
> +                               struct vectors * vecs);
> +int snprint_multipath_map_json (char * buff, int len,
> +                               struct multipath * mpp, int last);
>  int snprint_defaults (char *, int);
>  int snprint_blacklist (char *, int);
>  int snprint_blacklist_except (char *, int);
> diff --git a/multipathd/cli.c b/multipathd/cli.c
> index d991cd0..20ee3db 100644
> --- a/multipathd/cli.c
> +++ b/multipathd/cli.c
> @@ -207,6 +207,7 @@ load_keys (void)
>         r += add_key(keys, "setprstatus", SETPRSTATUS, 0);
>         r += add_key(keys, "unsetprstatus", UNSETPRSTATUS, 0);
>         r += add_key(keys, "format", FMT, 1);
> +       r += add_key(keys, "json", JSON, 0);
>
>         if (r) {
>                 free_keys(keys);
> @@ -537,8 +538,10 @@ cli_init (void) {
>         add_handler(LIST+MAPS+FMT, NULL);
>         add_handler(LIST+MAPS+RAW+FMT, NULL);
>         add_handler(LIST+MAPS+TOPOLOGY, NULL);
> +       add_handler(LIST+MAPS+JSON, NULL);
>         add_handler(LIST+TOPOLOGY, NULL);
>         add_handler(LIST+MAP+TOPOLOGY, NULL);
> +       add_handler(LIST+MAP+JSON, NULL);
>         add_handler(LIST+MAP+FMT, NULL);
>         add_handler(LIST+MAP+RAW+FMT, NULL);
>         add_handler(LIST+CONFIG, NULL);
> diff --git a/multipathd/cli.h b/multipathd/cli.h
> index 84ca40f..92cb41b 100644
> --- a/multipathd/cli.h
> +++ b/multipathd/cli.h
> @@ -36,6 +36,7 @@ enum {
>         __SETPRSTATUS,
>         __UNSETPRSTATUS,
>         __FMT,
> +       __JSON,
>  };
>
>  #define LIST           (1 << __LIST)
> @@ -74,6 +75,7 @@ enum {
>  #define SETPRSTATUS    (1ULL << __SETPRSTATUS)
>  #define UNSETPRSTATUS  (1ULL << __UNSETPRSTATUS)
>  #define FMT            (1ULL << __FMT)
> +#define JSON           (1ULL << __JSON)
>
>  #define INITIAL_REPLY_LEN      1200
>
> diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
> index 8b3cb9d..19cf2ff 100644
> --- a/multipathd/cli_handlers.c
> +++ b/multipathd/cli_handlers.c
> @@ -156,6 +156,70 @@ show_maps_topology (char ** r, int * len, struct
> vectors * vecs)
>  }
>
>  int
> +show_maps_json (char ** r, int * len, struct vectors * vecs)
> +{
> +       int i;
> +       struct multipath * mpp;
> +       char * c;
> +       char * reply;
> +       unsigned int maxlen = INITIAL_REPLY_LEN * PRINT_JSON_MULTIPLIER;
> +       int again = 1;
> +
> +       vector_foreach_slot(vecs->mpvec, mpp, i) {
> +               if (update_multipath(vecs, mpp->alias, 0)) {
> +                       return 1;
> +               }
> +       }
> +
> +       reply = MALLOC(maxlen);
> +
> +       while (again) {
> +               if (!reply)
> +                       return 1;
> +
> +               c = reply;
> +
> +               c += snprint_multipath_topology_json(c, reply + maxlen - c,
> +                               vecs);
> +               again = ((c - reply) == maxlen);
> +
> +               REALLOC_REPLY(reply, again, maxlen);
> +       }
> +       *r = reply;
> +       *len = (int)(c - reply + 1);
> +       return 0;
> +}
> +
> +int
> +show_map_json (char ** r, int * len, struct multipath * mpp,
> +                  struct vectors * vecs)
> +{
> +       char * c;
> +       char * reply;
> +       unsigned int maxlen = INITIAL_REPLY_LEN;
> +       int again = 1;
> +
> +       if (update_multipath(vecs, mpp->alias, 0))
> +               return 1;
> +       reply = MALLOC(maxlen);
> +
> +       while (again) {
> +               if (!reply)
> +                       return 1;
> +
> +               c = reply;
> +
> +               c += snprint_multipath_map_json(c, reply + maxlen - c,
> mpp, 1);
> +               again = ((c - reply) == maxlen);
> +
> +               REALLOC_REPLY(reply, again, maxlen);
> +       }
> +       *r = reply;
> +       *len = (int)(c - reply + 1);
> +       return 0;
> +}
> +
> +int
>  show_config (char ** r, int * len)
>  {
>         char * c;
> @@ -291,6 +355,35 @@ cli_list_maps_topology (void * v, char ** reply, int
> * len, void * data)
>  }
>
>  int
> +cli_list_map_json (void * v, char ** reply, int * len, void * data)
> +{
> +       struct multipath * mpp;
> +       struct vectors * vecs = (struct vectors *)data;
> +       char * param = get_keyparam(v, MAP);
> +
> +       param = convert_dev(param, 0);
> +       get_path_layout(vecs->pathvec, 0);
> +       mpp = find_mp_by_str(vecs->mpvec, param);
> +
> +       if (!mpp)
> +               return 1;
> +
> +       condlog(3, "list multipath json %s (operator)", param);
> +
> +       return show_map_json(reply, len, mpp, vecs);
> +}
> +
> +int
> +cli_list_maps_json (void * v, char ** reply, int * len, void * data)
> +{
> +       struct vectors * vecs = (struct vectors *)data;
> +
> +       condlog(3, "list multipaths json (operator)");
> +
> +       return show_maps_json(reply, len, vecs);
> +}
> +
> +int
>  cli_list_wildcards (void * v, char ** reply, int * len, void * data)
>  {
>         char * c;
> diff --git a/multipathd/cli_handlers.h b/multipathd/cli_handlers.h
> index 5d51018..e838f19 100644
> --- a/multipathd/cli_handlers.h
> +++ b/multipathd/cli_handlers.h
> @@ -13,6 +13,8 @@ int cli_list_maps_status (void * v, char ** reply, int *
> len, void * data);
>  int cli_list_maps_stats (void * v, char ** reply, int * len, void * data);
>  int cli_list_map_topology (void * v, char ** reply, int * len, void *
> data);
>  int cli_list_maps_topology (void * v, char ** reply, int * len, void *
> data);
> +int cli_list_map_json (void * v, char ** reply, int * len, void * data);
> +int cli_list_maps_json (void * v, char ** reply, int * len, void * data);
>  int cli_list_config (void * v, char ** reply, int * len, void * data);
>  int cli_list_blacklist (void * v, char ** reply, int * len, void * data);
>  int cli_list_devices (void * v, char ** reply, int * len, void * data);
> diff --git a/multipathd/main.c b/multipathd/main.c
> index 58e8854..33f38cd 100644
> --- a/multipathd/main.c
> +++ b/multipathd/main.c
> @@ -1120,9 +1120,11 @@ uxlsnrloop (void * ap)
>         set_handler_callback(LIST+MAPS+RAW+FMT, cli_list_maps_raw);
>         set_handler_callback(LIST+MAPS+TOPOLOGY, cli_list_maps_topology);
>         set_handler_callback(LIST+TOPOLOGY, cli_list_maps_topology);
> +       set_handler_callback(LIST+MAPS+JSON, cli_list_maps_json);
>         set_handler_callback(LIST+MAP+TOPOLOGY, cli_list_map_topology);
>         set_handler_callback(LIST+MAP+FMT, cli_list_map_fmt);
>         set_handler_callback(LIST+MAP+RAW+FMT, cli_list_map_fmt);
> +       set_handler_callback(LIST+MAP+JSON, cli_list_map_json);
>         set_unlocked_handler_callback(LIST+CONFIG, cli_list_config);
>         set_unlocked_handler_callback(LIST+BLACKLIST, cli_list_blacklist);
>         set_handler_callback(LIST+DEVICES, cli_list_devices);
> --
> 2.5.5
>
> --
> dm-devel mailing list
> dm-devel at redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>
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