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drbd: rcu_read_[un]lock() for all idr accesses that do not sleep
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Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
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Philipp Reisner committed Nov 8, 2012
1 parent cd1d995 commit 695d08f
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Showing 5 changed files with 74 additions and 19 deletions.
12 changes: 8 additions & 4 deletions drivers/block/drbd/drbd_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -453,8 +453,10 @@ void tl_clear(struct drbd_tconn *tconn)
}

/* ensure bit indicating barrier is required is clear */
rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr)
clear_bit(CREATE_BARRIER, &mdev->flags);
rcu_read_unlock();

spin_unlock_irq(&tconn->req_lock);
}
Expand Down Expand Up @@ -634,13 +636,15 @@ char *drbd_task_to_thread_name(struct drbd_tconn *tconn, struct task_struct *tas

int conn_lowest_minor(struct drbd_tconn *tconn)
{
int vnr = 0;
struct drbd_conf *mdev;
int vnr = 0, m;

rcu_read_lock();
mdev = idr_get_next(&tconn->volumes, &vnr);
if (!mdev)
return -1;
return mdev_to_minor(mdev);
m = mdev ? mdev_to_minor(mdev) : -1;
rcu_read_unlock();

return m;
}

#ifdef CONFIG_SMP
Expand Down
41 changes: 29 additions & 12 deletions drivers/block/drbd/drbd_nl.c
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Original file line number Diff line number Diff line change
Expand Up @@ -372,12 +372,14 @@ static enum drbd_fencing_p highest_fencing_policy(struct drbd_tconn *tconn)
struct drbd_conf *mdev;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
if (get_ldev_if_state(mdev, D_CONSISTENT)) {
fp = max_t(enum drbd_fencing_p, fp, mdev->ldev->dc.fencing);
put_ldev(mdev);
}
}
rcu_read_unlock();

return fp;
}
Expand Down Expand Up @@ -1624,29 +1626,41 @@ int drbd_adm_detach(struct sk_buff *skb, struct genl_info *info)
static bool conn_resync_running(struct drbd_tconn *tconn)
{
struct drbd_conf *mdev;
bool rv = false;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
if (mdev->state.conn == C_SYNC_SOURCE ||
mdev->state.conn == C_SYNC_TARGET ||
mdev->state.conn == C_PAUSED_SYNC_S ||
mdev->state.conn == C_PAUSED_SYNC_T)
return true;
mdev->state.conn == C_PAUSED_SYNC_T) {
rv = true;
break;
}
}
return false;
rcu_read_unlock();

return rv;
}

static bool conn_ov_running(struct drbd_tconn *tconn)
{
struct drbd_conf *mdev;
bool rv = false;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
if (mdev->state.conn == C_VERIFY_S ||
mdev->state.conn == C_VERIFY_T)
return true;
mdev->state.conn == C_VERIFY_T) {
rv = true;
break;
}
}
return false;
rcu_read_unlock();

return rv;
}

int drbd_adm_net_opts(struct sk_buff *skb, struct genl_info *info)
Expand Down Expand Up @@ -1858,26 +1872,28 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
goto fail;
}

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, i) {
if (get_ldev(mdev)) {
enum drbd_fencing_p fp = mdev->ldev->dc.fencing;
put_ldev(mdev);
if (new_conf->wire_protocol == DRBD_PROT_A && fp == FP_STONITH) {
retcode = ERR_STONITH_AND_PROT_A;
goto fail;
goto fail_rcu_unlock;
}
}
if (mdev->state.role == R_PRIMARY && new_conf->want_lose) {
retcode = ERR_DISCARD;
goto fail;
goto fail_rcu_unlock;
}
if (!mdev->bitmap) {
if(drbd_bm_init(mdev)) {
retcode = ERR_NOMEM;
goto fail;
goto fail_rcu_unlock;
}
}
}
rcu_read_unlock();

if (new_conf->on_congestion != OC_BLOCK && new_conf->wire_protocol != DRBD_PROT_A) {
retcode = ERR_CONG_NOT_PROTO_A;
Expand Down Expand Up @@ -1991,15 +2007,19 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info)
retcode = _conn_request_state(tconn, NS(conn, C_UNCONNECTED), CS_VERBOSE);
spin_unlock_irq(&tconn->req_lock);

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, i) {
mdev->send_cnt = 0;
mdev->recv_cnt = 0;
kobject_uevent(&disk_to_dev(mdev->vdisk)->kobj, KOBJ_CHANGE);
}
rcu_read_unlock();
conn_reconfig_done(tconn);
drbd_adm_finish(info, retcode);
return 0;

fail_rcu_unlock:
rcu_read_unlock();
fail:
kfree(int_dig_in);
kfree(int_dig_vv);
Expand Down Expand Up @@ -2562,8 +2582,6 @@ int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb)

/* synchronize with drbd_new_tconn/drbd_free_tconn */
mutex_lock(&drbd_cfg_mutex);
/* synchronize with drbd_delete_device */
rcu_read_lock();
next_tconn:
/* revalidate iterator position */
list_for_each_entry(tmp, &drbd_tconns, all_tconn) {
Expand Down Expand Up @@ -2624,7 +2642,6 @@ int drbd_adm_get_status_all(struct sk_buff *skb, struct netlink_callback *cb)
}

out:
rcu_read_unlock();
mutex_unlock(&drbd_cfg_mutex);
/* where to start the next iteration */
cb->args[0] = (long)pos;
Expand Down
2 changes: 2 additions & 0 deletions drivers/block/drbd/drbd_receiver.c
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Original file line number Diff line number Diff line change
Expand Up @@ -4828,11 +4828,13 @@ static int tconn_finish_peer_reqs(struct drbd_tconn *tconn)
set_bit(SIGNAL_ASENDER, &tconn->flags);

spin_lock_irq(&tconn->req_lock);
rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, i) {
not_empty = !list_empty(&mdev->done_ee);
if (not_empty)
break;
}
rcu_read_unlock();
spin_unlock_irq(&tconn->req_lock);
} while (not_empty);

Expand Down
34 changes: 31 additions & 3 deletions drivers/block/drbd/drbd_state.c
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Original file line number Diff line number Diff line change
Expand Up @@ -55,15 +55,21 @@ static inline bool is_susp(union drbd_state s)
bool conn_all_vols_unconf(struct drbd_tconn *tconn)
{
struct drbd_conf *mdev;
bool rv = true;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
if (mdev->state.disk != D_DISKLESS ||
mdev->state.conn != C_STANDALONE ||
mdev->state.role != R_SECONDARY)
return false;
mdev->state.role != R_SECONDARY) {
rv = false;
break;
}
}
return true;
rcu_read_unlock();

return rv;
}

/* Unfortunately the states where not correctly ordered, when
Expand Down Expand Up @@ -91,8 +97,10 @@ enum drbd_role conn_highest_role(struct drbd_tconn *tconn)
struct drbd_conf *mdev;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr)
role = max_role(role, mdev->state.role);
rcu_read_unlock();

return role;
}
Expand All @@ -103,8 +111,10 @@ enum drbd_role conn_highest_peer(struct drbd_tconn *tconn)
struct drbd_conf *mdev;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr)
peer = max_role(peer, mdev->state.peer);
rcu_read_unlock();

return peer;
}
Expand All @@ -115,8 +125,10 @@ enum drbd_disk_state conn_highest_disk(struct drbd_tconn *tconn)
struct drbd_conf *mdev;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr)
ds = max_t(enum drbd_disk_state, ds, mdev->state.disk);
rcu_read_unlock();

return ds;
}
Expand All @@ -127,8 +139,10 @@ enum drbd_disk_state conn_lowest_disk(struct drbd_tconn *tconn)
struct drbd_conf *mdev;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr)
ds = min_t(enum drbd_disk_state, ds, mdev->state.disk);
rcu_read_unlock();

return ds;
}
Expand All @@ -139,8 +153,10 @@ enum drbd_disk_state conn_highest_pdsk(struct drbd_tconn *tconn)
struct drbd_conf *mdev;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr)
ds = max_t(enum drbd_disk_state, ds, mdev->state.pdsk);
rcu_read_unlock();

return ds;
}
Expand All @@ -151,8 +167,10 @@ enum drbd_conns conn_lowest_conn(struct drbd_tconn *tconn)
struct drbd_conf *mdev;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr)
conn = min_t(enum drbd_conns, conn, mdev->state.conn);
rcu_read_unlock();

return conn;
}
Expand Down Expand Up @@ -1406,21 +1424,25 @@ static int w_after_conn_state_ch(struct drbd_work *w, int unused)
/* case1: The outdate peer handler is successful: */
if (ns_max.pdsk <= D_OUTDATED) {
tl_clear(tconn);
rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
if (test_bit(NEW_CUR_UUID, &mdev->flags)) {
drbd_uuid_new_current(mdev);
clear_bit(NEW_CUR_UUID, &mdev->flags);
}
}
rcu_read_unlock();
conn_request_state(tconn,
(union drbd_state) { { .susp_fen = 1 } },
(union drbd_state) { { .susp_fen = 0 } },
CS_VERBOSE);
}
/* case2: The connection was established again: */
if (ns_min.conn >= C_CONNECTED) {
rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr)
clear_bit(NEW_CUR_UUID, &mdev->flags);
rcu_read_unlock();
spin_lock_irq(&tconn->req_lock);
_tl_restart(tconn, RESEND);
_conn_request_state(tconn,
Expand All @@ -1445,6 +1467,7 @@ void conn_old_common_state(struct drbd_tconn *tconn, union drbd_state *pcs, enum
struct drbd_conf *mdev;
int vnr, first_vol = 1;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
os = mdev->state;

Expand All @@ -1469,6 +1492,7 @@ void conn_old_common_state(struct drbd_tconn *tconn, union drbd_state *pcs, enum
if (cs.pdsk != os.pdsk)
flags &= ~CS_DC_PDSK;
}
rcu_read_unlock();

*pf |= CS_DC_MASK;
*pf &= flags;
Expand All @@ -1484,6 +1508,7 @@ conn_is_valid_transition(struct drbd_tconn *tconn, union drbd_state mask, union
struct drbd_conf *mdev;
int vnr;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
os = drbd_read_state(mdev);
ns = sanitize_state(mdev, apply_mask_val(os, mask, val), NULL);
Expand All @@ -1509,6 +1534,7 @@ conn_is_valid_transition(struct drbd_tconn *tconn, union drbd_state mask, union
if (rv < SS_SUCCESS)
break;
}
rcu_read_unlock();

if (rv < SS_SUCCESS && flags & CS_VERBOSE)
print_st_err(mdev, os, ns, rv);
Expand All @@ -1534,6 +1560,7 @@ conn_set_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state
if (mask.conn == C_MASK)
tconn->cstate = val.conn;

rcu_read_lock();
idr_for_each_entry(&tconn->volumes, mdev, vnr) {
os = drbd_read_state(mdev);
ns = apply_mask_val(os, mask, val);
Expand All @@ -1559,6 +1586,7 @@ conn_set_state(struct drbd_tconn *tconn, union drbd_state mask, union drbd_state
ns_min.disk = min_t(enum drbd_disk_state, ns.disk, ns_min.disk);
ns_min.pdsk = min_t(enum drbd_disk_state, ns.pdsk, ns_min.pdsk);
}
rcu_read_unlock();

ns_min.susp = ns_max.susp = tconn->susp;
ns_min.susp_nod = ns_max.susp_nod = tconn->susp_nod;
Expand Down
4 changes: 4 additions & 0 deletions drivers/block/drbd/drbd_worker.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1348,13 +1348,15 @@ static int _drbd_pause_after(struct drbd_conf *mdev)
struct drbd_conf *odev;
int i, rv = 0;

rcu_read_lock();
idr_for_each_entry(&minors, odev, i) {
if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
continue;
if (!_drbd_may_sync_now(odev))
rv |= (__drbd_set_state(_NS(odev, aftr_isp, 1), CS_HARD, NULL)
!= SS_NOTHING_TO_DO);
}
rcu_read_unlock();

return rv;
}
Expand All @@ -1370,6 +1372,7 @@ static int _drbd_resume_next(struct drbd_conf *mdev)
struct drbd_conf *odev;
int i, rv = 0;

rcu_read_lock();
idr_for_each_entry(&minors, odev, i) {
if (odev->state.conn == C_STANDALONE && odev->state.disk == D_DISKLESS)
continue;
Expand All @@ -1380,6 +1383,7 @@ static int _drbd_resume_next(struct drbd_conf *mdev)
!= SS_NOTHING_TO_DO) ;
}
}
rcu_read_unlock();
return rv;
}

Expand Down

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