drbd: Implemented new commands to create/delete connections/minors

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

5 files changed, 120 insertions, 73 deletions

diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index a27e2a4e038d..535d503886d8 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -1258,7 +1258,6 @@ extern int drbd_bmio_clear_n_write(struct drbd_conf *mdev);
 extern void drbd_go_diskless(struct drbd_conf *mdev);
 extern void drbd_ldev_destroy(struct drbd_conf *mdev);
 
-
 /* Meta data layout
    We reserve a 128MB Block (4k aligned)
    * either at the end of the backing device
@@ -1476,8 +1475,9 @@ extern wait_queue_head_t drbd_pp_wait;
 extern rwlock_t global_state_lock;
 
 extern int conn_lowest_minor(struct drbd_tconn *tconn);
-extern struct drbd_conf *drbd_new_device(unsigned int minor);
+enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr);
 extern void drbd_free_mdev(struct drbd_conf *mdev);
+extern void drbd_delete_device(unsigned int minor);
 
 struct drbd_tconn *drbd_new_tconn(char *name);
 extern void drbd_free_tconn(struct drbd_tconn *tconn);
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 2bfd63058f40..ec7d0d98657c 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -614,13 +614,16 @@ char *drbd_task_to_thread_name(struct drbd_tconn *tconn, struct task_struct *tas
         return thi ? thi->name : task->comm;
 }
 
-#ifdef CONFIG_SMP
 int conn_lowest_minor(struct drbd_tconn *tconn)
 {
         int minor = 0;
-        idr_get_next(&tconn->volumes, &minor);
+
+        if (!idr_get_next(&tconn->volumes, &minor))
+                return -1;
         return minor;
 }
+
+#ifdef CONFIG_SMP
 /**
  * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs
  * @mdev:       DRBD device.
@@ -2078,15 +2081,16 @@ static void drbd_release_ee_lists(struct drbd_conf *mdev)
                 dev_err(DEV, "%d EEs in net list found!\n", rr);
 }
 
-/* caution. no locking.
- * currently only used from module cleanup code. */
-static void drbd_delete_device(unsigned int minor)
+/* caution. no locking. */
+void drbd_delete_device(unsigned int minor)
 {
         struct drbd_conf *mdev = minor_to_mdev(minor);
 
         if (!mdev)
                 return;
 
+        idr_remove(&mdev->tconn->volumes, minor);
+
         /* paranoia asserts */
         D_ASSERT(mdev->open_cnt == 0);
         D_ASSERT(list_empty(&mdev->tconn->data.work.q));
@@ -2101,7 +2105,6 @@ static void drbd_delete_device(unsigned int minor)
                 bdput(mdev->this_bdev);
 
         drbd_free_resources(mdev);
-        drbd_free_tconn(mdev->tconn);
 
         drbd_release_ee_lists(mdev);
 
@@ -2223,6 +2226,9 @@ struct drbd_tconn *drbd_new_tconn(char *name)
         if (!tconn->name)
                 goto fail;
 
+        if (!zalloc_cpumask_var(&tconn->cpu_mask, GFP_KERNEL))
+                goto fail;
+
         if (!tl_init(tconn))
                 goto fail;
 
@@ -2252,6 +2258,7 @@ struct drbd_tconn *drbd_new_tconn(char *name)
 
 fail:
         tl_cleanup(tconn);
+        free_cpumask_var(tconn->cpu_mask);
         kfree(tconn->name);
         kfree(tconn);
 
@@ -2265,6 +2272,7 @@ void drbd_free_tconn(struct drbd_tconn *tconn)
         write_unlock_irq(&global_state_lock);
         idr_destroy(&tconn->volumes);
 
+        free_cpumask_var(tconn->cpu_mask);
         kfree(tconn->name);
         kfree(tconn->int_dig_out);
         kfree(tconn->int_dig_in);
@@ -2272,32 +2280,31 @@ void drbd_free_tconn(struct drbd_tconn *tconn)
         kfree(tconn);
 }
 
-struct drbd_conf *drbd_new_device(unsigned int minor)
+enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr)
 {
         struct drbd_conf *mdev;
         struct gendisk *disk;
         struct request_queue *q;
-        char conn_name[9]; /* drbd1234N */
-        int vnr;
+        int vnr_got = vnr;
+
+        mdev = minor_to_mdev(minor);
+        if (mdev)
+                return ERR_MINOR_EXISTS;
 
         /* GFP_KERNEL, we are outside of all write-out paths */
         mdev = kzalloc(sizeof(struct drbd_conf), GFP_KERNEL);
         if (!mdev)
-                return NULL;
-        sprintf(conn_name, "drbd%d", minor);
-        mdev->tconn = drbd_new_tconn(conn_name);
-        if (!mdev->tconn)
-                goto out_no_tconn;
-        if (!idr_pre_get(&mdev->tconn->volumes, GFP_KERNEL))
-                goto out_no_cpumask;
-        if (idr_get_new(&mdev->tconn->volumes, mdev, &vnr))
-                goto out_no_cpumask;
-        if (vnr != 0) {
-                dev_err(DEV, "vnr = %d\n", vnr);
-                goto out_no_cpumask;
-        }
-        if (!zalloc_cpumask_var(&mdev->tconn->cpu_mask, GFP_KERNEL))
-                goto out_no_cpumask;
+                return ERR_NOMEM;
+
+        mdev->tconn = tconn;
+        if (!idr_pre_get(&tconn->volumes, GFP_KERNEL))
+                goto out_no_idr;
+        if (idr_get_new(&tconn->volumes, mdev, &vnr_got))
+                goto out_no_idr;
+        if (vnr_got != vnr) {
+                dev_err(DEV, "vnr_got (%d) != vnr (%d)\n", vnr_got, vnr);
+                goto out_no_q;
+        }
 
         mdev->minor = minor;
 
@@ -2354,7 +2361,10 @@ struct drbd_conf *drbd_new_device(unsigned int minor)
         INIT_LIST_HEAD(&mdev->current_epoch->list);
         mdev->epochs = 1;
 
-        return mdev;
+        minor_table[minor] = mdev;
+        add_disk(disk);
+
+        return NO_ERROR;
 
 /* out_whatever_else:
         kfree(mdev->current_epoch); */
@@ -2367,12 +2377,10 @@ out_no_io_page:
 out_no_disk:
         blk_cleanup_queue(q);
 out_no_q:
-        free_cpumask_var(mdev->tconn->cpu_mask);
-out_no_cpumask:
-        drbd_free_tconn(mdev->tconn);
-out_no_tconn:
+        idr_remove(&tconn->volumes, vnr_got);
+out_no_idr:
         kfree(mdev);
-        return NULL;
+        return ERR_NOMEM;
 }
 
 /* counterpart of drbd_new_device.
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 455a51dd364d..f2739fd188a0 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -443,40 +443,6 @@ drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, int force)
         return rv;
 }
 
-static struct drbd_conf *ensure_mdev(int minor, int create)
-{
-        struct drbd_conf *mdev;
-
-        if (minor >= minor_count)
-                return NULL;
-
-        mdev = minor_to_mdev(minor);
-
-        if (!mdev && create) {
-                struct gendisk *disk = NULL;
-                mdev = drbd_new_device(minor);
-
-                spin_lock_irq(&drbd_pp_lock);
-                if (minor_table[minor] == NULL) {
-                        minor_table[minor] = mdev;
-                        disk = mdev->vdisk;
-                        mdev = NULL;
-                } /* else: we lost the race */
-                spin_unlock_irq(&drbd_pp_lock);
-
-                if (disk) /* we won the race above */
-                        /* in case we ever add a drbd_delete_device(),
-                         * don't forget the del_gendisk! */
-                        add_disk(disk);
-                else /* we lost the race above */
-                        drbd_free_mdev(mdev);
-
-                mdev = minor_to_mdev(minor);
-        }
-
-        return mdev;
-}
-
 static int drbd_nl_primary(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
                            struct drbd_nl_cfg_reply *reply)
 {
@@ -1789,12 +1755,6 @@ static int drbd_nl_syncer_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *n
         if (!expect(sc.al_extents <= DRBD_AL_EXTENTS_MAX))
                 sc.al_extents = DRBD_AL_EXTENTS_MAX;
 
-        /* to avoid spurious errors when configuring minors before configuring
-         * the minors they depend on: if necessary, first create the minor we
-         * depend on */
-        if (sc.after >= 0)
-                ensure_mdev(sc.after, 1);
-
         /* most sanity checks done, try to assign the new sync-after
          * dependency.  need to hold the global lock in there,
          * to avoid a race in the dependency loop check. */
@@ -2184,13 +2144,73 @@ out:
         return 0;
 }
 
+static int drbd_nl_new_conn(struct drbd_nl_cfg_req *nlp, struct drbd_nl_cfg_reply *reply)
+{
+        struct new_connection args;
+
+        if (!new_connection_from_tags(nlp->tag_list, &args)) {
+                reply->ret_code = ERR_MANDATORY_TAG;
+                return 0;
+        }
+
+        reply->ret_code = NO_ERROR;
+        if (!drbd_new_tconn(args.name))
+                reply->ret_code = ERR_NOMEM;
+
+        return 0;
+}
+
+static int drbd_nl_new_minor(struct drbd_tconn *tconn,
+                      struct drbd_nl_cfg_req *nlp, struct drbd_nl_cfg_reply *reply)
+{
+        struct new_minor args;
+
+        args.vol_nr = 0;
+        args.minor = 0;
+
+        if (!new_minor_from_tags(nlp->tag_list, &args)) {
+                reply->ret_code = ERR_MANDATORY_TAG;
+                return 0;
+        }
+
+        reply->ret_code = conn_new_minor(tconn, args.minor, args.vol_nr);
+
+        return 0;
+}
+
+static int drbd_nl_del_minor(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
+                             struct drbd_nl_cfg_reply *reply)
+{
+        if (mdev->state.disk == D_DISKLESS &&
+            mdev->state.conn == C_STANDALONE &&
+            mdev->state.role == R_SECONDARY) {
+                drbd_delete_device(mdev_to_minor(mdev));
+                reply->ret_code = NO_ERROR;
+        } else {
+                reply->ret_code = ERR_MINOR_CONFIGURED;
+        }
+        return 0;
+}
+
+static int drbd_nl_del_conn(struct drbd_tconn *tconn,
+                            struct drbd_nl_cfg_req *nlp, struct drbd_nl_cfg_reply *reply)
+{
+        if (conn_lowest_minor(tconn) < 0) {
+                drbd_free_tconn(tconn);
+                reply->ret_code = NO_ERROR;
+        } else {
+                reply->ret_code = ERR_CONN_IN_USE;
+        }
+
+        return 0;
+}
+
 enum cn_handler_type {
         CHT_MINOR,
         CHT_CONN,
         CHT_CTOR,
         /* CHT_RES, later */
 };
-
 struct cn_handler_struct {
         enum cn_handler_type type;
         union {
@@ -2235,6 +2255,10 @@ static struct cn_handler_struct cnd_table[] = {
                                     sizeof(struct get_timeout_flag_tag_len_struct)},
         [ P_start_ov ]          = { CHT_MINOR, { &drbd_nl_start_ov },   0 },
         [ P_new_c_uuid ]        = { CHT_MINOR, { &drbd_nl_new_c_uuid }, 0 },
+        [ P_new_connection ]    = { CHT_CTOR,  { .constructor = &drbd_nl_new_conn }, 0 },
+        [ P_new_minor ]         = { CHT_CONN,  { .conn_based = &drbd_nl_new_minor }, 0 },
+        [ P_del_minor ]         = { CHT_MINOR, { &drbd_nl_del_minor },  0 },
+        [ P_del_connection ]    = { CHT_CONN,  { .conn_based = &drbd_nl_del_conn }, 0 },
 };
 
 static void drbd_connector_callback(struct cn_msg *req, struct netlink_skb_parms *nsp)
diff --git a/include/linux/drbd.h b/include/linux/drbd.h
index 7683b4ab6583..e192167e6145 100644
--- a/include/linux/drbd.h
+++ b/include/linux/drbd.h
@@ -156,6 +156,9 @@ enum drbd_ret_code {
         ERR_PIC_AFTER_DEP       = 156,
         ERR_PIC_PEER_DEP        = 157,
         ERR_CONN_NOT_KNOWN      = 158,
+        ERR_CONN_IN_USE         = 159,
+        ERR_MINOR_CONFIGURED    = 160,
+        ERR_MINOR_EXISTS        = 161,
 
         /* insert new ones above this line */
         AFTER_LAST_ERR_CODE
diff --git a/include/linux/drbd_nl.h b/include/linux/drbd_nl.h
index ab6159e4fcf0..1216c7a432c5 100644
--- a/include/linux/drbd_nl.h
+++ b/include/linux/drbd_nl.h
@@ -152,6 +152,18 @@ NL_PACKET(new_c_uuid, 26,
 NL_RESPONSE(return_code_only, 27)
 #endif
 
+NL_PACKET(new_connection, 28, /* CHT_CTOR */
+        NL_STRING(      85,     T_MANDATORY,    name, DRBD_NL_OBJ_NAME_LEN)
+)
+
+NL_PACKET(new_minor, 29, /* CHT_CONN */
+        NL_INTEGER(     86,     T_MANDATORY,    minor)
+        NL_INTEGER(     87,     T_MANDATORY,    vol_nr)
+)
+
+NL_PACKET(del_minor, 30, ) /* CHT_MINOR */
+NL_PACKET(del_connection, 31, ) /* CHT_CONN */
+
 #undef NL_PACKET
 #undef NL_INTEGER
 #undef NL_INT64