drbd: Basic refcounting for drbd_tconn

References hold by:
 * Each (running) drbd thread has a reference on tconn
 * Each mdev has a referenc on tconn
 * Beeing in the all_tconn list counts for one reference
 * Each after_conn_state_chg_work has a reference to tconn

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This commit is contained in:
Philipp Reisner 2011-04-22 15:23:32 +02:00
parent 1d04122599
commit 9dc9fbb357
4 changed files with 35 additions and 14 deletions

View File

@ -828,6 +828,7 @@ enum {
struct drbd_tconn { /* is a resource from the config file */ struct drbd_tconn { /* is a resource from the config file */
char *name; /* Resource name */ char *name; /* Resource name */
struct list_head all_tconn; /* linked on global drbd_tconns */ struct list_head all_tconn; /* linked on global drbd_tconns */
struct kref kref;
struct idr volumes; /* <tconn, vnr> to mdev mapping */ struct idr volumes; /* <tconn, vnr> to mdev mapping */
enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */ enum drbd_conns cstate; /* Only C_STANDALONE to C_WF_REPORT_PARAMS */
unsigned susp:1; /* IO suspended by user */ unsigned susp:1; /* IO suspended by user */
@ -1378,8 +1379,8 @@ extern int conn_lowest_minor(struct drbd_tconn *tconn);
enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr); enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor, int vnr);
extern void drbd_delete_device(struct drbd_conf *mdev); extern void drbd_delete_device(struct drbd_conf *mdev);
struct drbd_tconn *drbd_new_tconn(const char *name); struct drbd_tconn *conn_create(const char *name);
extern void drbd_free_tconn(struct drbd_tconn *tconn); extern void conn_destroy(struct kref *kref);
struct drbd_tconn *conn_by_name(const char *name); struct drbd_tconn *conn_by_name(const char *name);
extern void conn_free_crypto(struct drbd_tconn *tconn); extern void conn_free_crypto(struct drbd_tconn *tconn);

View File

@ -509,6 +509,8 @@ restart:
conn_info(tconn, "Terminating %s\n", current->comm); conn_info(tconn, "Terminating %s\n", current->comm);
/* Release mod reference taken when thread was started */ /* Release mod reference taken when thread was started */
kref_put(&tconn->kref, &conn_destroy);
module_put(THIS_MODULE); module_put(THIS_MODULE);
return retval; return retval;
} }
@ -546,6 +548,8 @@ int drbd_thread_start(struct drbd_thread *thi)
return false; return false;
} }
kref_get(&thi->tconn->kref);
init_completion(&thi->stop); init_completion(&thi->stop);
thi->reset_cpu_mask = 1; thi->reset_cpu_mask = 1;
thi->t_state = RUNNING; thi->t_state = RUNNING;
@ -558,6 +562,7 @@ int drbd_thread_start(struct drbd_thread *thi)
if (IS_ERR(nt)) { if (IS_ERR(nt)) {
conn_err(tconn, "Couldn't start thread\n"); conn_err(tconn, "Couldn't start thread\n");
kref_put(&tconn->kref, &conn_destroy);
module_put(THIS_MODULE); module_put(THIS_MODULE);
return false; return false;
} }
@ -2237,6 +2242,8 @@ static void drbd_release_all_peer_reqs(struct drbd_conf *mdev)
/* caution. no locking. */ /* caution. no locking. */
void drbd_delete_device(struct drbd_conf *mdev) void drbd_delete_device(struct drbd_conf *mdev)
{ {
struct drbd_tconn *tconn = mdev->tconn;
idr_remove(&mdev->tconn->volumes, mdev->vnr); idr_remove(&mdev->tconn->volumes, mdev->vnr);
idr_remove(&minors, mdev_to_minor(mdev)); idr_remove(&minors, mdev_to_minor(mdev));
synchronize_rcu(); synchronize_rcu();
@ -2272,6 +2279,8 @@ void drbd_delete_device(struct drbd_conf *mdev)
put_disk(mdev->vdisk); put_disk(mdev->vdisk);
blk_cleanup_queue(mdev->rq_queue); blk_cleanup_queue(mdev->rq_queue);
kfree(mdev); kfree(mdev);
kref_put(&tconn->kref, &conn_destroy);
} }
static void drbd_cleanup(void) static void drbd_cleanup(void)
@ -2409,7 +2418,7 @@ void conn_free_crypto(struct drbd_tconn *tconn)
tconn->int_dig_vv = NULL; tconn->int_dig_vv = NULL;
} }
struct drbd_tconn *drbd_new_tconn(const char *name) struct drbd_tconn *conn_create(const char *name)
{ {
struct drbd_tconn *tconn; struct drbd_tconn *tconn;
@ -2455,6 +2464,7 @@ struct drbd_tconn *drbd_new_tconn(const char *name)
}; };
down_write(&drbd_cfg_rwsem); down_write(&drbd_cfg_rwsem);
kref_init(&tconn->kref);
list_add_tail(&tconn->all_tconn, &drbd_tconns); list_add_tail(&tconn->all_tconn, &drbd_tconns);
up_write(&drbd_cfg_rwsem); up_write(&drbd_cfg_rwsem);
@ -2471,9 +2481,10 @@ fail:
return NULL; return NULL;
} }
void drbd_free_tconn(struct drbd_tconn *tconn) void conn_destroy(struct kref *kref)
{ {
list_del(&tconn->all_tconn); struct drbd_tconn *tconn = container_of(kref, struct drbd_tconn, kref);
idr_destroy(&tconn->volumes); idr_destroy(&tconn->volumes);
free_cpumask_var(tconn->cpu_mask); free_cpumask_var(tconn->cpu_mask);
@ -2503,7 +2514,9 @@ enum drbd_ret_code conn_new_minor(struct drbd_tconn *tconn, unsigned int minor,
if (!mdev) if (!mdev)
return ERR_NOMEM; return ERR_NOMEM;
kref_get(&tconn->kref);
mdev->tconn = tconn; mdev->tconn = tconn;
mdev->minor = minor; mdev->minor = minor;
mdev->vnr = vnr; mdev->vnr = vnr;
@ -2605,6 +2618,7 @@ out_no_disk:
blk_cleanup_queue(q); blk_cleanup_queue(q);
out_no_q: out_no_q:
kfree(mdev); kfree(mdev);
kref_put(&tconn->kref, &conn_destroy);
return err; return err;
} }

View File

@ -479,6 +479,7 @@ static int _try_outdate_peer_async(void *data)
conn_try_outdate_peer(tconn); conn_try_outdate_peer(tconn);
kref_put(&tconn->kref, &conn_destroy);
return 0; return 0;
} }
@ -486,9 +487,12 @@ void conn_try_outdate_peer_async(struct drbd_tconn *tconn)
{ {
struct task_struct *opa; struct task_struct *opa;
kref_get(&tconn->kref);
opa = kthread_run(_try_outdate_peer_async, tconn, "drbd_async_h"); opa = kthread_run(_try_outdate_peer_async, tconn, "drbd_async_h");
if (IS_ERR(opa)) if (IS_ERR(opa)) {
conn_err(tconn, "out of mem, failed to invoke fence-peer helper\n"); conn_err(tconn, "out of mem, failed to invoke fence-peer helper\n");
kref_put(&tconn->kref, &conn_destroy);
}
} }
enum drbd_state_rv enum drbd_state_rv
@ -2627,7 +2631,7 @@ int get_one_status(struct sk_buff *skb, struct netlink_callback *cb)
* on each iteration. * on each iteration.
*/ */
/* synchronize with drbd_new_tconn/drbd_free_tconn */ /* synchronize with conn_create()/conn_destroy() */
down_read(&drbd_cfg_rwsem); down_read(&drbd_cfg_rwsem);
/* revalidate iterator position */ /* revalidate iterator position */
list_for_each_entry(tmp, &drbd_tconns, all_tconn) { list_for_each_entry(tmp, &drbd_tconns, all_tconn) {
@ -2932,7 +2936,7 @@ int drbd_adm_create_connection(struct sk_buff *skb, struct genl_info *info)
goto out; goto out;
} }
if (!drbd_new_tconn(adm_ctx.conn_name)) if (!conn_create(adm_ctx.conn_name))
retcode = ERR_NOMEM; retcode = ERR_NOMEM;
out: out:
drbd_adm_finish(info, retcode); drbd_adm_finish(info, retcode);
@ -3005,10 +3009,6 @@ int drbd_adm_delete_minor(struct sk_buff *skb, struct genl_info *info)
down_write(&drbd_cfg_rwsem); down_write(&drbd_cfg_rwsem);
retcode = adm_delete_minor(adm_ctx.mdev); retcode = adm_delete_minor(adm_ctx.mdev);
up_write(&drbd_cfg_rwsem); up_write(&drbd_cfg_rwsem);
/* if this was the last volume of this connection,
* this will terminate all threads */
if (retcode == NO_ERROR)
conn_reconfig_done(adm_ctx.tconn);
out: out:
drbd_adm_finish(info, retcode); drbd_adm_finish(info, retcode);
return 0; return 0;
@ -3078,7 +3078,9 @@ int drbd_adm_down(struct sk_buff *skb, struct genl_info *info)
/* delete connection */ /* delete connection */
if (conn_lowest_minor(adm_ctx.tconn) < 0) { if (conn_lowest_minor(adm_ctx.tconn) < 0) {
drbd_free_tconn(adm_ctx.tconn); list_del(&adm_ctx.tconn->all_tconn);
kref_put(&adm_ctx.tconn->kref, &conn_destroy);
retcode = NO_ERROR; retcode = NO_ERROR;
} else { } else {
/* "can not happen" */ /* "can not happen" */
@ -3107,7 +3109,9 @@ int drbd_adm_delete_connection(struct sk_buff *skb, struct genl_info *info)
down_write(&drbd_cfg_rwsem); down_write(&drbd_cfg_rwsem);
if (conn_lowest_minor(adm_ctx.tconn) < 0) { if (conn_lowest_minor(adm_ctx.tconn) < 0) {
drbd_free_tconn(adm_ctx.tconn); list_del(&adm_ctx.tconn->all_tconn);
kref_put(&adm_ctx.tconn->kref, &conn_destroy);
retcode = NO_ERROR; retcode = NO_ERROR;
} else { } else {
retcode = ERR_CONN_IN_USE; retcode = ERR_CONN_IN_USE;

View File

@ -1460,6 +1460,7 @@ static int w_after_conn_state_ch(struct drbd_work *w, int unused)
//conn_err(tconn, STATE_FMT, STATE_ARGS("nms", nms)); //conn_err(tconn, STATE_FMT, STATE_ARGS("nms", nms));
after_all_state_ch(tconn); after_all_state_ch(tconn);
kref_put(&tconn->kref, &conn_destroy);
return 0; return 0;
} }
@ -1686,6 +1687,7 @@ _conn_request_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_
acscw->ns_max = ns_max; acscw->ns_max = ns_max;
acscw->flags = flags; acscw->flags = flags;
acscw->w.cb = w_after_conn_state_ch; acscw->w.cb = w_after_conn_state_ch;
kref_get(&tconn->kref);
acscw->w.tconn = tconn; acscw->w.tconn = tconn;
drbd_queue_work(&tconn->data.work, &acscw->w); drbd_queue_work(&tconn->data.work, &acscw->w);
} else { } else {