gluster: GlusterFS Volume Snapshot Feature

This is the initial patch for the Snapshot feature. Current patch
includes following features:
* Snapshot create
* Snapshot delete
* Snapshot restore
* Snapshot list
* Snapshot info
* Snapshot status
* Snapshot config

Change-Id: I2f46920c0d61c515f6a60e0f8b46fff886d9f6a9
BUG: 1061685
Signed-off-by: shishir gowda <sgowda@redhat.com>
Signed-off-by: Sachin Pandit <spandit@redhat.com>
Signed-off-by: Vijaikumar M <vmallika@redhat.com>
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Signed-off-by: Rajesh Joseph <rjoseph@redhat.com>
Signed-off-by: Joseph Fernandes <josferna@redhat.com>
Signed-off-by: Avra Sengupta <asengupt@redhat.com>
Reviewed-on: http://review.gluster.org/7128
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

4 files changed, 489 insertions, 5 deletions

diff --git a/xlators/protocol/server/src/server-helpers.c b/xlators/protocol/server/src/server-helpers.c
index c11011abf9f..76c0036e08b 100644
--- a/xlators/protocol/server/src/server-helpers.c
+++ b/xlators/protocol/server/src/server-helpers.c
@@ -1092,3 +1092,327 @@ out:
 
         return ret;
 }
+
+int32_t
+gf_barrier_transmit (server_conf_t *conf, gf_barrier_payload_t *payload)
+{
+        gf_barrier_t            *barrier = NULL;
+        int32_t                  ret     = -1;
+        client_t                *client  = NULL;
+        gf_boolean_t             lk_heal = _gf_false;
+        call_frame_t            *frame   = NULL;
+        server_state_t          *state   = NULL;
+
+        GF_VALIDATE_OR_GOTO ("barrier", conf, out);
+        GF_VALIDATE_OR_GOTO ("barrier", conf->barrier, out);
+        GF_VALIDATE_OR_GOTO ("barrier", payload, out);
+
+        barrier = conf->barrier;
+
+        frame = payload->frame;
+        if (frame) {
+                state = CALL_STATE (frame);
+                frame->local = NULL;
+                client = frame->root->client;
+        }
+        /* currently lk fops are not barrier'ed. This is reflecting code in
+         * server_submit_reply */
+        if (client)
+                lk_heal = ((server_conf_t *) client->this->private)->lk_heal;
+
+        ret = rpcsvc_submit_generic (payload->req, &payload->rsp, 1,
+                                     payload->payload, payload->payload_count,
+                                     payload->iobref);
+        iobuf_unref (payload->iob);
+        if (ret == -1) {
+                gf_log_callingfn ("", GF_LOG_ERROR, "Reply submission failed");
+                if (frame && client && !lk_heal) {
+                        server_connection_cleanup (frame->this, client,
+                                                  INTERNAL_LOCKS | POSIX_LOCKS);
+                } else {
+                        /* TODO: Failure of open(dir), create, inodelk, entrylk
+                           or lk fops send failure must be handled specially. */
+                }
+                goto ret;
+        }
+
+        ret = 0;
+ret:
+        if (state) {
+                free_state (state);
+        }
+
+        if (frame) {
+                gf_client_unref (client);
+                STACK_DESTROY (frame->root);
+        }
+
+        if (payload->free_iobref) {
+                iobref_unref (payload->iobref);
+        }
+out:
+        return ret;
+}
+
+gf_barrier_payload_t *
+gf_barrier_dequeue (gf_barrier_t *barrier)
+{
+        gf_barrier_payload_t  *payload = NULL;
+
+        if (!barrier || list_empty (&barrier->queue))
+                return NULL;
+
+        payload = list_entry (barrier->queue.next,
+                              gf_barrier_payload_t, list);
+        if (payload) {
+                list_del_init (&payload->list);
+                barrier->cur_size--;
+        }
+
+        return payload;
+}
+
+
+void*
+gf_barrier_dequeue_start (void *data)
+{
+        server_conf_t           *conf = NULL;
+        gf_barrier_t            *barrier = NULL;
+        gf_barrier_payload_t    *payload = NULL;
+
+        conf = (server_conf_t *)data;
+        if (!conf || !conf->barrier)
+                return NULL;
+        barrier = conf->barrier;
+
+        LOCK (&barrier->lock);
+        {
+                while (barrier->cur_size) {
+                        payload = gf_barrier_dequeue (barrier);
+                        if (payload) {
+                                if (gf_barrier_transmit (conf, payload)) {
+                                        gf_log ("server", GF_LOG_WARNING,
+                                                "Failed to transmit");
+                                }
+                                GF_FREE (payload);
+                        }
+                }
+        }
+        UNLOCK (&barrier->lock);
+        return NULL;
+}
+
+void
+gf_barrier_timeout (void *data)
+{
+        server_conf_t *conf = NULL;
+        gf_barrier_t  *barrier = NULL;
+        gf_boolean_t   need_dequeue = _gf_false;
+
+        conf = (server_conf_t *)data;
+        if (!conf || !conf->barrier)
+                goto out;
+        barrier = conf->barrier;
+
+        gf_log ("", GF_LOG_INFO, "barrier timed-out");
+        LOCK (&barrier->lock);
+        {
+                need_dequeue = barrier->on;
+                barrier->on = _gf_false;
+        }
+        UNLOCK (&barrier->lock);
+
+        if (need_dequeue == _gf_true)
+                gf_barrier_dequeue_start (data);
+out:
+        return;
+}
+
+
+int32_t
+gf_barrier_start (xlator_t *this)
+{
+        server_conf_t *conf = NULL;
+        gf_barrier_t  *barrier = NULL;
+        int32_t        ret  = -1;
+        struct timespec time = {0,};
+
+        conf = this->private;
+
+        GF_VALIDATE_OR_GOTO ("server", this, out);
+        GF_VALIDATE_OR_GOTO (this->name, conf, out);
+        GF_VALIDATE_OR_GOTO (this->name, conf->barrier, out);
+
+        barrier = conf->barrier;
+
+        gf_log (this->name, GF_LOG_INFO, "barrier start called");
+        LOCK (&barrier->lock);
+        {
+                /* if barrier is on, reset timer */
+                if (barrier->on == _gf_true) {
+                        ret = gf_timer_call_cancel (this->ctx, barrier->timer);
+                        if (ret) {
+                                gf_log (this->name, GF_LOG_ERROR, "Failed to "
+                                        "unset timer, failing barrier start");
+                                goto unlock;
+                        }
+                }
+
+                barrier->on = _gf_true;
+                time.tv_sec = barrier->time_out;
+                time.tv_nsec = 0;
+
+                barrier->timer = gf_timer_call_after (this->ctx, time,
+                                                      gf_barrier_timeout,
+                                                      (void *)conf);
+                if (!barrier->timer) {
+                        gf_log (this->name, GF_LOG_ERROR, "Failed to set "
+                                "timer, failing barrier start");
+                        barrier->on = _gf_false;
+                }
+        }
+unlock:
+        UNLOCK (&barrier->lock);
+
+        ret = 0;
+out:
+        return ret;
+}
+
+int32_t
+gf_barrier_stop (xlator_t *this)
+{
+        server_conf_t *conf = NULL;
+        gf_barrier_t  *barrier = NULL;
+        int32_t        ret  = -1;
+        gf_boolean_t   need_dequeue = _gf_false;
+
+        conf = this->private;
+
+        GF_VALIDATE_OR_GOTO ("server", this, out);
+        GF_VALIDATE_OR_GOTO (this->name, conf, out);
+        GF_VALIDATE_OR_GOTO (this->name, conf->barrier, out);
+
+        barrier = conf->barrier;
+
+        gf_log (this->name, GF_LOG_INFO, "barrier stop called");
+        LOCK (&barrier->lock);
+        {
+                need_dequeue = barrier->on;
+                barrier->on = _gf_false;
+        }
+        UNLOCK (&barrier->lock);
+
+        if (need_dequeue == _gf_true) {
+                gf_timer_call_cancel (this->ctx, barrier->timer);
+                ret = gf_thread_create (&conf->barrier_th, NULL,
+                                        gf_barrier_dequeue_start,
+                                        conf);
+                if (ret) {
+                        gf_log (this->name, GF_LOG_CRITICAL,
+                                "Failed to start un-barriering");
+                        goto out;
+                }
+        }
+        ret = 0;
+out:
+        return ret;
+}
+
+int32_t
+gf_barrier_fops_configure (xlator_t *this, gf_barrier_t *barrier, char *str)
+{
+        int32_t         ret = -1;
+        char           *dup_str = NULL;
+        char           *str_tok = NULL;
+        char           *save_ptr = NULL;
+        uint64_t        fops = 0;
+
+        /* by defaul fsync & flush needs to be barriered */
+
+        fops |= 1 << GFS3_OP_FSYNC;
+        fops |= 1 << GFS3_OP_FLUSH;
+
+        if (!str)
+                goto done;
+
+        dup_str = gf_strdup (str);
+        if (!dup_str)
+                goto done;
+
+        str_tok = strtok_r (dup_str, ",", &save_ptr);
+        if (!str_tok)
+                goto done;
+
+        fops = 0;
+        while (str_tok) {
+                if (!strcmp(str_tok, "writev")) {
+                        fops |= ((uint64_t)1 << GFS3_OP_WRITE);
+                } else if (!strcmp(str_tok, "fsync")) {
+                        fops |= ((uint64_t)1 << GFS3_OP_FSYNC);
+                } else if (!strcmp(str_tok, "read")) {
+                        fops |= ((uint64_t)1 << GFS3_OP_READ);
+                } else if (!strcmp(str_tok, "rename")) {
+                        fops |= ((uint64_t)1 << GFS3_OP_RENAME);
+                } else if (!strcmp(str_tok, "flush")) {
+                        fops |= ((uint64_t)1 << GFS3_OP_FLUSH);
+                } else if (!strcmp(str_tok, "ftruncate")) {
+                        fops |= ((uint64_t)1 << GFS3_OP_FTRUNCATE);
+                } else if (!strcmp(str_tok, "fallocate")) {
+                        fops |= ((uint64_t)1 << GFS3_OP_FALLOCATE);
+                } else if (!strcmp(str_tok, "rmdir")) {
+                        fops |= ((uint64_t)1 << GFS3_OP_RMDIR);
+                }  else {
+                        gf_log ("barrier", GF_LOG_ERROR,
+                                "Invalid barrier fop %s", str_tok);
+                }
+
+                str_tok = strtok_r (NULL, ",", &save_ptr);
+        }
+done:
+        LOCK (&barrier->lock);
+        {
+                barrier->fops = fops;
+        }
+        UNLOCK (&barrier->lock);
+        ret = 0;
+
+        GF_FREE (dup_str);
+        return ret;
+}
+
+void
+gf_barrier_enqueue (gf_barrier_t *barrier, gf_barrier_payload_t *payload)
+{
+        list_add_tail (&payload->list, &barrier->queue);
+        barrier->cur_size++;
+}
+
+gf_barrier_payload_t *
+gf_barrier_payload (rpcsvc_request_t *req, struct iovec *rsp,
+                    call_frame_t *frame, struct iovec *payload_orig,
+                    int payloadcount, struct iobref *iobref,
+                    struct iobuf *iob, gf_boolean_t free_iobref)
+{
+        gf_barrier_payload_t *payload = NULL;
+
+        if (!rsp)
+                return NULL;
+
+        payload = GF_CALLOC (1, sizeof (*payload),1);
+        if (!payload)
+                return NULL;
+
+        INIT_LIST_HEAD (&payload->list);
+
+        payload->req = req;
+        memcpy (&payload->rsp, rsp, sizeof (struct iovec));
+        payload->frame = frame;
+        payload->payload = payload_orig;
+        payload->payload_count = payloadcount;
+        payload->iobref = iobref;
+        payload->iob = iob;
+        payload->free_iobref = free_iobref;
+
+        return payload;
+}
diff --git a/xlators/protocol/server/src/server-helpers.h b/xlators/protocol/server/src/server-helpers.h
index 3c257b3bcef..486048b8ad3 100644
--- a/xlators/protocol/server/src/server-helpers.h
+++ b/xlators/protocol/server/src/server-helpers.h
@@ -29,6 +29,10 @@
 
 #define IS_NOT_ROOT(pathlen) ((pathlen > 2)? 1 : 0)
 
+#define is_fop_barriered(fops, procnum) (fops & ((uint64_t)1 << procnum))
+
+#define barrier_add_to_queue(barrier) (barrier->on || barrier->cur_size)
+
 void free_state (server_state_t *state);
 
 void server_loc_wipe (loc_t *loc);
@@ -58,4 +62,15 @@ int auth_set_username_passwd (dict_t *input_params, dict_t *config_params,
 
 server_ctx_t *server_ctx_get (client_t *client, xlator_t *xlator);
 
+int32_t gf_barrier_start (xlator_t *this);
+int32_t gf_barrier_stop (xlator_t *this);
+int32_t gf_barrier_fops_configure (xlator_t *this, gf_barrier_t *barrier,
+                                   char *str);
+void gf_barrier_enqueue (gf_barrier_t *barrier, gf_barrier_payload_t *stub);
+gf_barrier_payload_t *
+gf_barrier_payload (rpcsvc_request_t *req, struct iovec *rsp,
+                    call_frame_t *frame, struct iovec *payload,
+                    int payloadcount, struct iobref *iobref,
+                    struct iobuf *iob, gf_boolean_t free_iobref);
+
 #endif /* !_SERVER_HELPERS_H */
diff --git a/xlators/protocol/server/src/server.c b/xlators/protocol/server/src/server.c
index 378aa393a50..7855170586a 100644
--- a/xlators/protocol/server/src/server.c
+++ b/xlators/protocol/server/src/server.c
@@ -130,8 +130,6 @@ ret:
         return iob;
 }
 
-
-
 int
 server_submit_reply (call_frame_t *frame, rpcsvc_request_t *req, void *arg,
                      struct iovec *payload, int payloadcount,
@@ -144,6 +142,10 @@ server_submit_reply (call_frame_t *frame, rpcsvc_request_t *req, void *arg,
         char                    new_iobref = 0;
         client_t               *client     = NULL;
         gf_boolean_t            lk_heal    = _gf_false;
+        server_conf_t          *conf       = NULL;
+        gf_barrier_t           *barrier    = NULL;
+        gf_barrier_payload_t   *stub       = NULL;
+        gf_boolean_t            barriered  = _gf_false;
 
         GF_VALIDATE_OR_GOTO ("server", req, ret);
 
@@ -151,6 +153,7 @@ server_submit_reply (call_frame_t *frame, rpcsvc_request_t *req, void *arg,
                 state = CALL_STATE (frame);
                 frame->local = NULL;
                 client = frame->root->client;
+                conf = (server_conf_t *) client->this->private;
         }
 
         if (client)
@@ -173,6 +176,32 @@ server_submit_reply (call_frame_t *frame, rpcsvc_request_t *req, void *arg,
 
         iobref_add (iobref, iob);
 
+        if (conf)
+                barrier = conf->barrier;
+        if (barrier) {
+                /* todo: write's with fd flags set to O_SYNC and O_DIRECT */
+                LOCK (&barrier->lock);
+                {
+                        if (is_fop_barriered (barrier->fops, req->procnum) &&
+                            (barrier_add_to_queue (barrier))) {
+                                stub = gf_barrier_payload (req, &rsp, frame,
+                                                           payload,
+                                                           payloadcount, iobref,
+                                                           iob, new_iobref);
+                                if (stub) {
+                                        gf_barrier_enqueue (barrier, stub);
+                                        barriered = _gf_true;
+                                } else {
+                                        gf_log ("", GF_LOG_ERROR, "Failed to "
+                                                " barrier fop %"PRIu64,
+                                                ((uint64_t)1 << req->procnum));
+                                }
+                        }
+                }
+                UNLOCK (&barrier->lock);
+                if (barriered == _gf_true)
+                        goto out;
+        }
         /* Then, submit the message for transmission. */
         ret = rpcsvc_submit_generic (req, &rsp, 1, payload, payloadcount,
                                      iobref);
@@ -214,7 +243,7 @@ ret:
         if (new_iobref) {
                 iobref_unref (iobref);
         }
-
+out:
         return ret;
 }
 
@@ -798,6 +827,8 @@ init (xlator_t *this)
         server_conf_t     *conf     = NULL;
         rpcsvc_listener_t *listener = NULL;
         char              *statedump_path = NULL;
+        gf_barrier_t      *barrier  = NULL;
+        char              *str      = NULL;
         GF_VALIDATE_OR_GOTO ("init", this, out);
 
         if (this->children == NULL) {
@@ -946,6 +977,37 @@ init (xlator_t *this)
                 }
         }
 #endif
+        /* barrier related */
+        barrier = GF_CALLOC (1, sizeof (*barrier),1);
+        if (!barrier) {
+                gf_log (this->name, GF_LOG_WARNING,
+                        "WARNING: Failed to allocate barrier");
+                ret = -1;
+                goto out;
+        }
+
+        LOCK_INIT (&barrier->lock);
+        INIT_LIST_HEAD (&barrier->queue);
+        barrier->on = _gf_false;
+
+        GF_OPTION_INIT ("barrier-queue-length", barrier->max_size,
+                        int64, out);
+        GF_OPTION_INIT ("barrier-timeout", barrier->time_out,
+                        uint64, out);
+
+        ret = dict_get_str (this->options, "barrier-fops", &str);
+        if (ret) {
+                gf_log (this->name, GF_LOG_DEBUG,
+                        "setting barrier fops to default value");
+        }
+        ret = gf_barrier_fops_configure (this, barrier, str);
+        if (ret) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "invalid barrier fops specified");
+                goto out;
+        }
+
+        conf->barrier = barrier;
         this->private = conf;
 
         ret = 0;
@@ -999,12 +1061,48 @@ int
 notify (xlator_t *this, int32_t event, void *data, ...)
 {
         int          ret = 0;
+        int32_t      val = 0;
+        dict_t      *dict = NULL;
+        dict_t      *output = NULL;
+        va_list      ap;
+
+        dict = data;
+        va_start (ap, data);
+        output = va_arg (ap, dict_t*);
+        va_end (ap);
+
         switch (event) {
+        case GF_EVENT_VOLUME_BARRIER_OP:
+               ret = dict_get_int32 (dict, "barrier", &val);
+               if (ret) {
+                       gf_log (this->name, GF_LOG_ERROR,
+                               "Wrong BARRIER event");
+                       goto out;
+               }
+               /* !val un-barrier, if val, barrier */
+               if (val) {
+                       ret = gf_barrier_start (this);
+                       if (ret)
+                                gf_log (this->name, GF_LOG_ERROR,
+                                        "Barrier start failed");
+               } else {
+                       ret = gf_barrier_stop (this);
+                       if (ret)
+                               gf_log (this->name, GF_LOG_ERROR,
+                                       "Barrier stop failed");
+               }
+               ret = dict_set_int32 (output, "barrier-status", ret);
+               if (ret)
+                       gf_log (this->name, GF_LOG_ERROR,
+                               "Failed to set barrier-status in dict");
+               break;
+
+               /* todo: call default_notify to make other xlators handle it.*/
         default:
                 default_notify (this, event, data);
                 break;
         }
-
+out:
         return ret;
 }
 
@@ -1128,6 +1226,23 @@ struct volume_options options[] = {
                          "overrides the auth.allow option. By default, all"
                          " connections are allowed."
         },
-
+        {.key  = {"barrier-timeout"},
+         .type = GF_OPTION_TYPE_INT,
+         .default_value = "60",
+         .min  = 0,
+         .max  = 360,
+         .description = "Barrier timeout in seconds",
+        },
+        {.key  = {"barrier-queue-length"},
+         .type = GF_OPTION_TYPE_INT,
+         .default_value = "4096",
+         .min  = 0,
+         .max  = 16384,
+         .description = "Barrier queue length",
+        },
+        {.key = {"barrier-fops"},
+         .type = GF_OPTION_TYPE_STR,
+         .description = "Allow a comma seperated fop lists",
+        },
         { .key   = {NULL} },
 };
diff --git a/xlators/protocol/server/src/server.h b/xlators/protocol/server/src/server.h
index 43e84921c8a..782327d775b 100644
--- a/xlators/protocol/server/src/server.h
+++ b/xlators/protocol/server/src/server.h
@@ -28,6 +28,34 @@
 #define GF_MAX_SOCKET_WINDOW_SIZE  (1 * GF_UNIT_MB)
 #define GF_MIN_SOCKET_WINDOW_SIZE  (0)
 
+struct _gf_barrier_payload {
+        rpcsvc_request_t        *req;
+        struct iovec            rsp;
+        call_frame_t            *frame;
+        struct iovec            *payload;
+        struct iobref           *iobref;
+        struct iobuf            *iob;
+        int                      payload_count;
+        gf_boolean_t             free_iobref;
+        struct list_head         list;
+};
+
+typedef struct _gf_barrier_payload gf_barrier_payload_t;
+
+struct _gf_barrier {
+        gf_lock_t               lock;
+        gf_boolean_t            on;
+        gf_boolean_t            force;
+        size_t                  cur_size;
+        int64_t                 max_size;
+        uint64_t                fops;
+        gf_timer_t             *timer;
+        uint64_t                time_out;
+        struct list_head        queue;
+};
+
+typedef struct _gf_barrier gf_barrier_t;
+
 typedef enum {
         INTERNAL_LOCKS = 1,
         POSIX_LOCKS = 2,
@@ -56,7 +84,9 @@ struct server_conf {
         struct timespec         grace_ts;
         dict_t                 *auth_modules;
         pthread_mutex_t         mutex;
+        gf_barrier_t           *barrier;
         struct list_head        xprt_list;
+        pthread_t               barrier_th;
 };
 typedef struct server_conf server_conf_t;