and send no more than credits value requests at once. For SMB/CIFS
it's trivial: increment this value by receiving any message and
decrement by sending one.
Signed-off-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
---
fs/cifs/cifsglob.h | 1 +
fs/cifs/cifssmb.c | 3 +++
fs/cifs/connect.c | 10 ++++------
fs/cifs/transport.c | 20 ++++++++++++++++----
4 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 76e7d8b..f96752a 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -256,6 +256,7 @@ struct TCP_Server_Info {
bool noautotune; /* do not autotune send buf sizes */
bool tcp_nodelay;
atomic_t inFlight; /* number of requests on the wire to server */
+ atomic_t credits; /* send no more requests at once */
struct mutex srv_mutex;
struct task_struct *tsk;
char server_GUID[16];
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 8b7794c..fbc4437 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -717,6 +717,7 @@ cifs_echo_callback(struct mid_q_entry *mid)
DeleteMidQEntry(mid);
atomic_dec(&server->inFlight);
+ atomic_inc(&server->credits);
wake_up(&server->request_q);
}
@@ -1670,6 +1671,7 @@ cifs_readv_callback(struct mid_q_entry *mid)
queue_work(system_nrt_wq, &rdata->work);
DeleteMidQEntry(mid);
atomic_dec(&server->inFlight);
+ atomic_inc(&server->credits);
wake_up(&server->request_q);
}
@@ -2111,6 +2113,7 @@ cifs_writev_callback(struct mid_q_entry *mid)
queue_work(system_nrt_wq, &wdata->work);
DeleteMidQEntry(mid);
atomic_dec(&tcon->ses->server->inFlight);
+ atomic_inc(&tcon->ses->server->credits);
wake_up(&tcon->ses->server->request_q);
}
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 602f77c..6b95304 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -648,12 +648,8 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
* time to as little as two.
*/
spin_lock(&GlobalMid_Lock);
- if (atomic_read(&server->inFlight) >= cifs_max_pending)
- atomic_set(&server->inFlight, cifs_max_pending - 1);
- /*
- * We do not want to set the max_pending too low or we could end up
- * with the counter going negative.
- */
+ if (atomic_read(&server->credits) == 0)
+ atomic_set(&server->credits, 1);
spin_unlock(&GlobalMid_Lock);
/*
* Although there should not be any requests blocked on this queue it
@@ -3759,9 +3755,11 @@ int cifs_negotiate_protocol(unsigned int xid, struct cifs_ses *ses)
if (server->maxBuf != 0)
return 0;
+ atomic_set(&ses->server->credits, cifs_max_pending);
rc = CIFSSMBNegotiate(xid, ses);
if (rc == -EAGAIN) {
/* retry only once on 1st time connection */
+ atomic_set(&ses->server->credits, cifs_max_pending);
rc = CIFSSMBNegotiate(xid, ses);
if (rc == -EAGAIN)
rc = -EHOSTDOWN;
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 0cc9584..f1f927f 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -260,17 +260,17 @@ static int wait_for_free_request(struct TCP_Server_Info *server,
if (long_op == CIFS_ASYNC_OP) {
/* oplock breaks must not be held up */
atomic_inc(&server->inFlight);
+ atomic_dec(&server->credits);
return 0;
}
spin_lock(&GlobalMid_Lock);
while (1) {
- if (atomic_read(&server->inFlight) >= cifs_max_pending) {
+ if (atomic_read(&server->credits) == 0) {
spin_unlock(&GlobalMid_Lock);
cifs_num_waiters_inc(server);
wait_event(server->request_q,
- atomic_read(&server->inFlight)
- < cifs_max_pending);
+ atomic_read(&server->credits) > 0);
cifs_num_waiters_dec(server);
spin_lock(&GlobalMid_Lock);
} else {
@@ -283,8 +283,10 @@ static int wait_for_free_request(struct TCP_Server_Info *server,
as they are allowed to block on server */
/* update # of requests on the wire to server */
- if (long_op != CIFS_BLOCKING_OP)
+ if (long_op != CIFS_BLOCKING_OP) {
atomic_inc(&server->inFlight);
+ atomic_dec(&server->credits);
+ }
spin_unlock(&GlobalMid_Lock);
break;
}
@@ -360,6 +362,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
if (mid == NULL) {
mutex_unlock(&server->srv_mutex);
atomic_dec(&server->inFlight);
+ atomic_inc(&server->credits);
wake_up(&server->request_q);
return -ENOMEM;
}
@@ -393,6 +396,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
out_err:
delete_mid(mid);
atomic_dec(&server->inFlight);
+ atomic_inc(&server->credits);
wake_up(&server->request_q);
return rc;
}
@@ -565,6 +569,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
cifs_small_buf_release(in_buf);
/* Update # of requests on wire to server */
atomic_dec(&ses->server->inFlight);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -602,6 +607,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
spin_unlock(&GlobalMid_Lock);
cifs_small_buf_release(in_buf);
atomic_dec(&ses->server->inFlight);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -613,6 +619,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
rc = cifs_sync_mid_result(midQ, ses->server);
if (rc != 0) {
atomic_dec(&ses->server->inFlight);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -638,6 +645,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
out:
delete_mid(midQ);
atomic_dec(&ses->server->inFlight);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
@@ -689,6 +697,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
mutex_unlock(&ses->server->srv_mutex);
/* Update # of requests on wire to server */
atomic_dec(&ses->server->inFlight);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -722,6 +731,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
midQ->callback = DeleteMidQEntry;
spin_unlock(&GlobalMid_Lock);
atomic_dec(&ses->server->inFlight);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -731,6 +741,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
rc = cifs_sync_mid_result(midQ, ses->server);
if (rc != 0) {
atomic_dec(&ses->server->inFlight);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -748,6 +759,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
out:
delete_mid(midQ);
atomic_dec(&ses->server->inFlight);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
--
1.7.1
--
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