[Drbd-dev] [PATCH 12/18] drbd: drbd_adm_get_status needs to show some more detail
Philipp Reisner
philipp.reisner at linbit.com
Thu Sep 1 14:48:59 CEST 2011
From: Lars Ellenberg <lars.ellenberg at linbit.com>
We want to see existing connection objects, even if they do not
currently have volumes attached.
Change the .dumpit variant of drbd_adm_get_status to iterate not over
minor devices, but over connections + volumes.
Signed-off-by: Philipp Reisner <philipp.reisner at linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg at linbit.com>
---
drivers/block/drbd/drbd_int.h | 3 +-
drivers/block/drbd/drbd_main.c | 15 +++---
drivers/block/drbd/drbd_nl.c | 117 +++++++++++++++++++++++++++++++++-------
3 files changed, 107 insertions(+), 28 deletions(-)
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index f4c3c71..d84a073 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -171,6 +171,7 @@ drbd_insert_fault(struct drbd_conf *mdev, unsigned int type) {
extern struct ratelimit_state drbd_ratelimit_state;
extern struct idr minors;
extern struct list_head drbd_tconns;
+extern struct mutex drbd_cfg_mutex;
/* on the wire */
enum drbd_packet {
@@ -918,7 +919,7 @@ enum {
struct drbd_tconn { /* is a resource from the config file */
char *name; /* Resource name */
- struct list_head all_tconn; /* List of all drbd_tconn, prot by global_state_lock */
+ struct list_head all_tconn; /* linked on global drbd_tconns */
struct idr volumes; /* <tconn, vnr> to mdev mapping */
enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */
struct mutex cstate_mutex; /* Protects graceful disconnects */
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 64bf9b6..2e79032 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -120,6 +120,7 @@ module_param_string(usermode_helper, usermode_helper, sizeof(usermode_helper), 0
*/
struct idr minors;
struct list_head drbd_tconns; /* list of struct drbd_tconn */
+DEFINE_MUTEX(drbd_cfg_mutex);
struct kmem_cache *drbd_request_cache;
struct kmem_cache *drbd_ee_cache; /* peer requests */
@@ -2238,14 +2239,14 @@ struct drbd_tconn *conn_by_name(const char *name)
if (!name || !name[0])
return NULL;
- write_lock_irq(&global_state_lock);
+ mutex_lock(&drbd_cfg_mutex);
list_for_each_entry(tconn, &drbd_tconns, all_tconn) {
if (!strcmp(tconn->name, name))
goto found;
}
tconn = NULL;
found:
- write_unlock_irq(&global_state_lock);
+ mutex_unlock(&drbd_cfg_mutex);
return tconn;
}
@@ -2285,9 +2286,9 @@ struct drbd_tconn *drbd_new_tconn(const char *name)
drbd_thread_init(tconn, &tconn->worker, drbd_worker, "worker");
drbd_thread_init(tconn, &tconn->asender, drbd_asender, "asender");
- write_lock_irq(&global_state_lock);
- list_add(&tconn->all_tconn, &drbd_tconns);
- write_unlock_irq(&global_state_lock);
+ mutex_lock(&drbd_cfg_mutex);
+ list_add_tail(&tconn->all_tconn, &drbd_tconns);
+ mutex_unlock(&drbd_cfg_mutex);
return tconn;
@@ -2302,9 +2303,9 @@ fail:
void drbd_free_tconn(struct drbd_tconn *tconn)
{
- write_lock_irq(&global_state_lock);
+ mutex_lock(&drbd_cfg_mutex);
list_del(&tconn->all_tconn);
- write_unlock_irq(&global_state_lock);
+ mutex_unlock(&drbd_cfg_mutex);
idr_destroy(&tconn->volumes);
free_cpumask_var(tconn->cpu_mask);
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index b40c83d..c389995 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1577,6 +1577,10 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
new_my_addr = (struct sockaddr *)&new_conf->my_addr;
new_peer_addr = (struct sockaddr *)&new_conf->peer_addr;
+
+ /* No need to take drbd_cfg_mutex here. All reconfiguration is
+ * strictly serialized on genl_lock(). We are protected against
+ * concurrent reconfiguration/addition/deletion */
list_for_each_entry(oconn, &drbd_tconns, all_tconn) {
if (oconn == tconn)
continue;
@@ -2220,6 +2224,24 @@ int drbd_adm_outdate(struct sk_buff *skb, struct genl_info *info)
return drbd_adm_simple_request_state(skb, info, NS(disk, D_OUTDATED));
}
+int nla_put_drbd_cfg_context(struct sk_buff *skb, const char *conn_name, unsigned vnr)
+{
+ struct nlattr *nla;
+ nla = nla_nest_start(skb, DRBD_NLA_CFG_CONTEXT);
+ if (!nla)
+ goto nla_put_failure;
+ if (vnr != VOLUME_UNSPECIFIED)
+ NLA_PUT_U32(skb, T_ctx_volume, vnr);
+ NLA_PUT_STRING(skb, T_ctx_conn_name, conn_name);
+ nla_nest_end(skb, nla);
+ return 0;
+
+nla_put_failure:
+ if (nla)
+ nla_nest_cancel(skb, nla);
+ return -EMSGSIZE;
+}
+
int nla_put_status_info(struct sk_buff *skb, struct drbd_conf *mdev,
const struct sib_info *sib)
{
@@ -2248,12 +2270,8 @@ int nla_put_status_info(struct sk_buff *skb, struct drbd_conf *mdev,
/* We need to add connection name and volume number information still.
* Minor number is in drbd_genlmsghdr. */
- nla = nla_nest_start(skb, DRBD_NLA_CFG_CONTEXT);
- if (!nla)
+ if (nla_put_drbd_cfg_context(skb, mdev->tconn->name, mdev->vnr))
goto nla_put_failure;
- NLA_PUT_U32(skb, T_ctx_volume, mdev->vnr);
- NLA_PUT_STRING(skb, T_ctx_conn_name, mdev->tconn->name);
- nla_nest_end(skb, nla);
if (got_ldev)
if (disk_conf_to_skb(skb, &mdev->ldev->dc, exclude_sensitive))
@@ -2340,43 +2358,102 @@ int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb)
{
struct drbd_conf *mdev;
struct drbd_genlmsghdr *dh;
- int minor = cb->args[0];
-
- /* Open coded deferred single idr_for_each_entry iteration.
+ struct drbd_tconn *pos = (struct drbd_tconn*)cb->args[0];
+ struct drbd_tconn *tconn = NULL;
+ struct drbd_tconn *tmp;
+ unsigned volume = cb->args[1];
+
+ /* Open coded, deferred, iteration:
+ * list_for_each_entry_safe(tconn, tmp, &drbd_tconns, all_tconn) {
+ * idr_for_each_entry(&tconn->volumes, mdev, i) {
+ * ...
+ * }
+ * }
+ * where tconn is cb->args[0];
+ * and i is cb->args[1];
+ *
* This may miss entries inserted after this dump started,
* or entries deleted before they are reached.
- * But we need to make sure the mdev won't disappear while
- * we are looking at it. */
+ *
+ * We need to make sure the mdev won't disappear while
+ * we are looking at it, and revalidate our iterators
+ * on each iteration.
+ */
+ /* synchronize with drbd_new_tconn/drbd_free_tconn */
+ mutex_lock(&drbd_cfg_mutex);
+ /* synchronize with drbd_delete_device */
rcu_read_lock();
- mdev = idr_get_next(&minors, &minor);
- if (mdev) {
+next_tconn:
+ /* revalidate iterator position */
+ list_for_each_entry(tmp, &drbd_tconns, all_tconn) {
+ if (pos == NULL) {
+ /* first iteration */
+ pos = tmp;
+ tconn = pos;
+ break;
+ }
+ if (tmp == pos) {
+ tconn = pos;
+ break;
+ }
+ }
+ if (tconn) {
+ mdev = idr_get_next(&tconn->volumes, &volume);
+ if (!mdev) {
+ /* No more volumes to dump on this tconn.
+ * Advance tconn iterator. */
+ pos = list_entry(tconn->all_tconn.next,
+ struct drbd_tconn, all_tconn);
+ /* But, did we dump any volume on this tconn yet? */
+ if (volume != 0) {
+ tconn = NULL;
+ volume = 0;
+ goto next_tconn;
+ }
+ }
+
dh = genlmsg_put(skb, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, &drbd_genl_family,
NLM_F_MULTI, DRBD_ADM_GET_STATUS);
if (!dh)
- goto errout;
+ goto out;
+
+ if (!mdev) {
+ /* this is a tconn without a single volume */
+ dh->minor = -1U;
+ dh->ret_code = NO_ERROR;
+ if (nla_put_drbd_cfg_context(skb, tconn->name, VOLUME_UNSPECIFIED))
+ genlmsg_cancel(skb, dh);
+ else
+ genlmsg_end(skb, dh);
+ goto out;
+ }
- D_ASSERT(mdev->minor == minor);
+ D_ASSERT(mdev->vnr == volume);
+ D_ASSERT(mdev->tconn == tconn);
- dh->minor = minor;
+ dh->minor = mdev_to_minor(mdev);
dh->ret_code = NO_ERROR;
pr_info("dump: minor=%u, conn=%s[%u]\n",
dh->minor, mdev->tconn->name, mdev->vnr);
if (nla_put_status_info(skb, mdev, NULL)) {
genlmsg_cancel(skb, dh);
- goto errout;
+ goto out;
}
genlmsg_end(skb, dh);
}
-errout:
+out:
rcu_read_unlock();
- /* where to start idr_get_next with the next iteration */
- cb->args[0] = minor+1;
+ mutex_unlock(&drbd_cfg_mutex);
+ /* where to start the next iteration */
+ cb->args[0] = (long)pos;
+ cb->args[1] = (pos == tconn) ? volume + 1 : 0;
- /* No more minors found: empty skb. Which will terminate the dump. */
+ /* No more tconns/volumes/minors found results in an empty skb.
+ * Which will terminate the dump. */
return skb->len;
}
--
1.7.4.1
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