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-rw-r--r--drivers/block/drbd/drbd_int.h54
-rw-r--r--drivers/block/drbd/drbd_main.c7
-rw-r--r--drivers/block/drbd/drbd_req.c93
-rw-r--r--drivers/block/drbd/drbd_worker.c3
4 files changed, 119 insertions, 38 deletions
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 3f8281bbea53..08fa2dc8cdba 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -317,7 +317,59 @@ struct drbd_request {
struct list_head tl_requests; /* ring list in the transfer log */
struct bio *master_bio; /* master bio pointer */
- unsigned long start_time;
+
+ /* for generic IO accounting */
+ unsigned long start_jif;
+
+ /* for DRBD internal statistics */
+
+ /* Minimal set of time stamps to determine if we wait for activity log
+ * transactions, local disk or peer. 32 bit "jiffies" are good enough,
+ * we don't expect a DRBD request to be stalled for several month.
+ */
+
+ /* before actual request processing */
+ unsigned long in_actlog_jif;
+
+ /* local disk */
+ unsigned long pre_submit_jif;
+
+ /* per connection */
+ unsigned long pre_send_jif;
+ unsigned long acked_jif;
+ unsigned long net_done_jif;
+
+ /* Possibly even more detail to track each phase:
+ * master_completion_jif
+ * how long did it take to complete the master bio
+ * (application visible latency)
+ * allocated_jif
+ * how long the master bio was blocked until we finally allocated
+ * a tracking struct
+ * in_actlog_jif
+ * how long did we wait for activity log transactions
+ *
+ * net_queued_jif
+ * when did we finally queue it for sending
+ * pre_send_jif
+ * when did we start sending it
+ * post_send_jif
+ * how long did we block in the network stack trying to send it
+ * acked_jif
+ * when did we receive (or fake, in protocol A) a remote ACK
+ * net_done_jif
+ * when did we receive final acknowledgement (P_BARRIER_ACK),
+ * or decide, e.g. on connection loss, that we do no longer expect
+ * anything from this peer for this request.
+ *
+ * pre_submit_jif
+ * post_sub_jif
+ * when did we start submiting to the lower level device,
+ * and how long did we block in that submit function
+ * local_completion_jif
+ * how long did it take the lower level device to complete this request
+ */
+
/* once it hits 0, we may complete the master_bio */
atomic_t completion_ref;
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 3ab74619c8eb..0baec7a3fa81 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -29,6 +29,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
+#include <linux/jiffies.h>
#include <linux/drbd.h>
#include <asm/uaccess.h>
#include <asm/types.h>
@@ -264,7 +265,7 @@ bail:
/**
* _tl_restart() - Walks the transfer log, and applies an action to all requests
- * @device: DRBD device.
+ * @connection: DRBD connection to operate on.
* @what: The action/event to perform with all request objects
*
* @what might be one of CONNECTION_LOST_WHILE_PENDING, RESEND, FAIL_FROZEN_DISK_IO,
@@ -2228,7 +2229,7 @@ static void do_retry(struct work_struct *ws)
list_for_each_entry_safe(req, tmp, &writes, tl_requests) {
struct drbd_device *device = req->device;
struct bio *bio = req->master_bio;
- unsigned long start_time = req->start_time;
+ unsigned long start_jif = req->start_jif;
bool expected;
expected =
@@ -2263,7 +2264,7 @@ static void do_retry(struct work_struct *ws)
/* We are not just doing generic_make_request(),
* as we want to keep the start_time information. */
inc_ap_bio(device);
- __drbd_make_request(device, bio, start_time);
+ __drbd_make_request(device, bio, start_jif);
}
}
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 3824d5c737e6..1319beab1b37 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -52,7 +52,7 @@ static void _drbd_start_io_acct(struct drbd_device *device, struct drbd_request
static void _drbd_end_io_acct(struct drbd_device *device, struct drbd_request *req)
{
int rw = bio_data_dir(req->master_bio);
- unsigned long duration = jiffies - req->start_time;
+ unsigned long duration = jiffies - req->start_jif;
int cpu;
cpu = part_stat_lock();
part_stat_add(cpu, &device->vdisk->part0, ticks[rw], duration);
@@ -66,7 +66,7 @@ static struct drbd_request *drbd_req_new(struct drbd_device *device,
{
struct drbd_request *req;
- req = mempool_alloc(drbd_request_mempool, GFP_NOIO);
+ req = mempool_alloc(drbd_request_mempool, GFP_NOIO | __GFP_ZERO);
if (!req)
return NULL;
@@ -366,14 +366,18 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m,
atomic_inc(&req->completion_ref);
}
- if (!(s & RQ_NET_QUEUED) && (set & RQ_NET_QUEUED))
+ if (!(s & RQ_NET_QUEUED) && (set & RQ_NET_QUEUED)) {
atomic_inc(&req->completion_ref);
+ }
if (!(s & RQ_EXP_BARR_ACK) && (set & RQ_EXP_BARR_ACK))
kref_get(&req->kref); /* wait for the DONE */
- if (!(s & RQ_NET_SENT) && (set & RQ_NET_SENT))
- atomic_add(req->i.size >> 9, &device->ap_in_flight);
+ if (!(s & RQ_NET_SENT) && (set & RQ_NET_SENT)) {
+ /* potentially already completed in the asender thread */
+ if (!(s & RQ_NET_DONE))
+ atomic_add(req->i.size >> 9, &device->ap_in_flight);
+ }
if (!(s & RQ_COMPLETION_SUSP) && (set & RQ_COMPLETION_SUSP))
atomic_inc(&req->completion_ref);
@@ -401,15 +405,18 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m,
if ((s & RQ_NET_PENDING) && (clear & RQ_NET_PENDING)) {
dec_ap_pending(device);
++c_put;
+ req->acked_jif = jiffies;
}
if ((s & RQ_NET_QUEUED) && (clear & RQ_NET_QUEUED))
++c_put;
- if ((s & RQ_EXP_BARR_ACK) && !(s & RQ_NET_DONE) && (set & RQ_NET_DONE)) {
- if (req->rq_state & RQ_NET_SENT)
+ if (!(s & RQ_NET_DONE) && (set & RQ_NET_DONE)) {
+ if (s & RQ_NET_SENT)
atomic_sub(req->i.size >> 9, &device->ap_in_flight);
- ++k_put;
+ if (s & RQ_EXP_BARR_ACK)
+ ++k_put;
+ req->net_done_jif = jiffies;
}
/* potentially complete and destroy */
@@ -449,6 +456,19 @@ static void drbd_report_io_error(struct drbd_device *device, struct drbd_request
bdevname(device->ldev->backing_bdev, b));
}
+/* Helper for HANDED_OVER_TO_NETWORK.
+ * Is this a protocol A write (neither WRITE_ACK nor RECEIVE_ACK expected)?
+ * Is it also still "PENDING"?
+ * --> If so, clear PENDING and set NET_OK below.
+ * If it is a protocol A write, but not RQ_PENDING anymore, neg-ack was faster
+ * (and we must not set RQ_NET_OK) */
+static inline bool is_pending_write_protocol_A(struct drbd_request *req)
+{
+ return (req->rq_state &
+ (RQ_WRITE|RQ_NET_PENDING|RQ_EXP_WRITE_ACK|RQ_EXP_RECEIVE_ACK))
+ == (RQ_WRITE|RQ_NET_PENDING);
+}
+
/* obviously this could be coded as many single functions
* instead of one huge switch,
* or by putting the code directly in the respective locations
@@ -627,18 +647,16 @@ int __req_mod(struct drbd_request *req, enum drbd_req_event what,
case HANDED_OVER_TO_NETWORK:
/* assert something? */
- if (bio_data_dir(req->master_bio) == WRITE &&
- !(req->rq_state & (RQ_EXP_RECEIVE_ACK | RQ_EXP_WRITE_ACK))) {
+ if (is_pending_write_protocol_A(req))
/* this is what is dangerous about protocol A:
* pretend it was successfully written on the peer. */
- if (req->rq_state & RQ_NET_PENDING)
- mod_rq_state(req, m, RQ_NET_PENDING, RQ_NET_OK);
- /* else: neg-ack was faster... */
- /* it is still not yet RQ_NET_DONE until the
- * corresponding epoch barrier got acked as well,
- * so we know what to dirty on connection loss */
- }
- mod_rq_state(req, m, RQ_NET_QUEUED, RQ_NET_SENT);
+ mod_rq_state(req, m, RQ_NET_QUEUED|RQ_NET_PENDING,
+ RQ_NET_SENT|RQ_NET_OK);
+ else
+ mod_rq_state(req, m, RQ_NET_QUEUED, RQ_NET_SENT);
+ /* It is still not yet RQ_NET_DONE until the
+ * corresponding epoch barrier got acked as well,
+ * so we know what to dirty on connection loss. */
break;
case OOS_HANDED_TO_NETWORK:
@@ -1037,6 +1055,7 @@ drbd_submit_req_private_bio(struct drbd_request *req)
* stable storage, and this is a WRITE, we may not even submit
* this bio. */
if (get_ldev(device)) {
+ req->pre_submit_jif = jiffies;
if (drbd_insert_fault(device,
rw == WRITE ? DRBD_FAULT_DT_WR
: rw == READ ? DRBD_FAULT_DT_RD
@@ -1063,7 +1082,7 @@ static void drbd_queue_write(struct drbd_device *device, struct drbd_request *re
* Returns ERR_PTR(-ENOMEM) if we cannot allocate a drbd_request.
*/
static struct drbd_request *
-drbd_request_prepare(struct drbd_device *device, struct bio *bio, unsigned long start_time)
+drbd_request_prepare(struct drbd_device *device, struct bio *bio, unsigned long start_jif)
{
const int rw = bio_data_dir(bio);
struct drbd_request *req;
@@ -1078,7 +1097,7 @@ drbd_request_prepare(struct drbd_device *device, struct bio *bio, unsigned long
bio_endio(bio, -ENOMEM);
return ERR_PTR(-ENOMEM);
}
- req->start_time = start_time;
+ req->start_jif = start_jif;
if (!get_ldev(device)) {
bio_put(req->private_bio);
@@ -1095,6 +1114,7 @@ drbd_request_prepare(struct drbd_device *device, struct bio *bio, unsigned long
return NULL;
}
req->rq_state |= RQ_IN_ACT_LOG;
+ req->in_actlog_jif = jiffies;
}
return req;
@@ -1197,9 +1217,9 @@ out:
complete_master_bio(device, &m);
}
-void __drbd_make_request(struct drbd_device *device, struct bio *bio, unsigned long start_time)
+void __drbd_make_request(struct drbd_device *device, struct bio *bio, unsigned long start_jif)
{
- struct drbd_request *req = drbd_request_prepare(device, bio, start_time);
+ struct drbd_request *req = drbd_request_prepare(device, bio, start_jif);
if (IS_ERR_OR_NULL(req))
return;
drbd_send_and_submit(device, req);
@@ -1218,6 +1238,7 @@ static void submit_fast_path(struct drbd_device *device, struct list_head *incom
continue;
req->rq_state |= RQ_IN_ACT_LOG;
+ req->in_actlog_jif = jiffies;
}
list_del_init(&req->tl_requests);
@@ -1240,7 +1261,6 @@ static bool prepare_al_transaction_nonblock(struct drbd_device *device,
wake = 1;
if (err)
continue;
- req->rq_state |= RQ_IN_ACT_LOG;
list_move_tail(&req->tl_requests, pending);
}
spin_unlock_irq(&device->al_lock);
@@ -1302,6 +1322,8 @@ skip_fast_path:
drbd_al_begin_io_commit(device);
list_for_each_entry_safe(req, tmp, &pending, tl_requests) {
+ req->rq_state |= RQ_IN_ACT_LOG;
+ req->in_actlog_jif = jiffies;
list_del_init(&req->tl_requests);
drbd_send_and_submit(device, req);
}
@@ -1311,9 +1333,12 @@ skip_fast_path:
* requests to cold extents. In that case, prepare one request
* in blocking mode. */
list_for_each_entry_safe(req, tmp, &incoming, tl_requests) {
+ bool was_cold;
list_del_init(&req->tl_requests);
- req->rq_state |= RQ_IN_ACT_LOG;
- if (!drbd_al_begin_io_prepare(device, &req->i)) {
+ was_cold = drbd_al_begin_io_prepare(device, &req->i);
+ if (!was_cold) {
+ req->rq_state |= RQ_IN_ACT_LOG;
+ req->in_actlog_jif = jiffies;
/* Corresponding extent was hot after all? */
drbd_send_and_submit(device, req);
} else {
@@ -1330,9 +1355,9 @@ skip_fast_path:
void drbd_make_request(struct request_queue *q, struct bio *bio)
{
struct drbd_device *device = (struct drbd_device *) q->queuedata;
- unsigned long start_time;
+ unsigned long start_jif;
- start_time = jiffies;
+ start_jif = jiffies;
/*
* what we "blindly" assume:
@@ -1340,7 +1365,7 @@ void drbd_make_request(struct request_queue *q, struct bio *bio)
D_ASSERT(device, IS_ALIGNED(bio->bi_iter.bi_size, 512));
inc_ap_bio(device);
- __drbd_make_request(device, bio, start_time);
+ __drbd_make_request(device, bio, start_jif);
}
/* This is called by bio_add_page().
@@ -1453,13 +1478,13 @@ void request_timer_fn(unsigned long data)
* to expire twice (worst case) to become effective. Good enough.
*/
if (ent && req_peer &&
- time_after(now, req_peer->start_time + ent) &&
+ time_after(now, req_peer->start_jif + ent) &&
!time_in_range(now, connection->last_reconnect_jif, connection->last_reconnect_jif + ent)) {
drbd_warn(device, "Remote failed to finish a request within ko-count * timeout\n");
_drbd_set_state(_NS(device, conn, C_TIMEOUT), CS_VERBOSE | CS_HARD, NULL);
}
if (dt && req_disk &&
- time_after(now, req_disk->start_time + dt) &&
+ time_after(now, req_disk->start_jif + dt) &&
!time_in_range(now, device->last_reattach_jif, device->last_reattach_jif + dt)) {
drbd_warn(device, "Local backing device failed to meet the disk-timeout\n");
__drbd_chk_io_error(device, DRBD_FORCE_DETACH);
@@ -1467,10 +1492,10 @@ void request_timer_fn(unsigned long data)
/* Reschedule timer for the nearest not already expired timeout.
* Fallback to now + min(effective network timeout, disk timeout). */
- ent = (ent && req_peer && time_before(now, req_peer->start_time + ent))
- ? req_peer->start_time + ent : now + et;
- dt = (dt && req_disk && time_before(now, req_disk->start_time + dt))
- ? req_disk->start_time + dt : now + et;
+ ent = (ent && req_peer && time_before(now, req_peer->start_jif + ent))
+ ? req_peer->start_jif + ent : now + et;
+ dt = (dt && req_disk && time_before(now, req_disk->start_jif + dt))
+ ? req_disk->start_jif + dt : now + et;
nt = time_before(ent, dt) ? ent : dt;
spin_unlock_irq(&connection->resource->req_lock);
mod_timer(&device->request_timer, nt);
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 3978d9ec6f00..0ff8f4637741 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1368,6 +1368,7 @@ int w_send_out_of_sync(struct drbd_work *w, int cancel)
req_mod(req, SEND_CANCELED);
return 0;
}
+ req->pre_send_jif = jiffies;
/* this time, no connection->send.current_epoch_writes++;
* If it was sent, it was the closing barrier for the last
@@ -1398,6 +1399,7 @@ int w_send_dblock(struct drbd_work *w, int cancel)
req_mod(req, SEND_CANCELED);
return 0;
}
+ req->pre_send_jif = jiffies;
re_init_if_first_write(connection, req->epoch);
maybe_send_barrier(connection, req->epoch);
@@ -1426,6 +1428,7 @@ int w_send_read_req(struct drbd_work *w, int cancel)
req_mod(req, SEND_CANCELED);
return 0;
}
+ req->pre_send_jif = jiffies;
/* Even read requests may close a write epoch,
* if there was any yet. */
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 04:04:10 +0100