From: Steve French <sfrench@xxxxxxxxxx>
Convert wait_for_free_request to wait on available credits
for SMB2 servers and decrement a credit number for every call.
Increment the credit number in smb2_sendrcv2 with every response
got from the server.
Signed-off-by: Pavel Shilovsky <piastry@xxxxxxxxxxx>
---
fs/cifs/cifsglob.h | 1 +
fs/cifs/cifsproto.h | 2 +-
fs/cifs/smb2transport.c | 6 ++++++
fs/cifs/transport.c | 20 ++++++++++++++++++--
4 files changed, 26 insertions(+), 3 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index bb2af48..e5f0b86 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -318,6 +318,7 @@ struct TCP_Server_Info {
atomic_t num_waiters; /* blocked waiting to get in sendrecv */
#endif
#ifdef CONFIG_CIFS_SMB2
+ atomic_t credits; /* send no more simultaneous requests than this */
__u64 current_smb2_mid; /* multiplex id - rotating counter */
#endif
};
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index d1e30d9..b6c784b 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -1,7 +1,7 @@
/*
* fs/cifs/cifsproto.h
*
- * Copyright (c) International Business Machines Corp., 2002,2008
+ * Copyright (c) International Business Machines Corp., 2002,2011
* Author(s): Steve French (sfrench@xxxxxxxxxx)
*
* This library is free software; you can redistribute it and/or modify
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index d7f1c05..b5702f3 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -148,6 +148,7 @@ smb2_sendrcv2(const unsigned int xid, struct cifs_ses *ses,
unsigned int receive_len;
struct mid_q_entry *midQ;
struct smb2_hdr *buf = iov[0].iov_base;
+ unsigned int credits = 1;
if (status)
*status = STATUS_SUCCESS;
@@ -186,6 +187,7 @@ smb2_sendrcv2(const unsigned int xid, struct cifs_ses *ses,
if (rc) {
mutex_unlock(&ses->server->srv_mutex);
cifs_small_buf_release(buf);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -222,6 +224,7 @@ smb2_sendrcv2(const unsigned int xid, struct cifs_ses *ses,
midQ->callback = cifs_delete_mid;
spin_unlock(&GlobalMid_Lock);
cifs_small_buf_release(buf);
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -232,6 +235,7 @@ smb2_sendrcv2(const unsigned int xid, struct cifs_ses *ses,
rc = cifs_sync_mid_result(midQ, ses->server);
if (rc) {
+ atomic_inc(&ses->server->credits);
wake_up(&ses->server->request_q);
return rc;
}
@@ -271,7 +275,9 @@ smb2_sendrcv2(const unsigned int xid, struct cifs_ses *ses,
/* mark it so buf will not be freed by free_smb2mid */
midQ->resp_buf = NULL;
+ credits = le16_to_cpu(buf->CreditRequest);
out:
+ atomic_add(credits, &ses->server->credits);
cifs_delete_mid(midQ);
wake_up(&ses->server->request_q);
return rc;
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index f7ac3f0..4414df8 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -287,7 +287,8 @@ cifs_wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
spin_lock(&GlobalMid_Lock);
while (1) {
- if (atomic_read(&server->inFlight) >= cifs_max_pending) {
+ if ((server->is_smb2 == false) &&
+ atomic_read(&server->inFlight) >= cifs_max_pending) {
spin_unlock(&GlobalMid_Lock);
cifs_num_waiters_inc(server);
wait_event(server->request_q,
@@ -295,6 +296,16 @@ cifs_wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
< cifs_max_pending);
cifs_num_waiters_dec(server);
spin_lock(&GlobalMid_Lock);
+#ifdef CONFIG_CIFS_SMB2
+ } else if (server->is_smb2 &&
+ (atomic_read(&server->credits) < 1)) {
+ spin_unlock(&GlobalMid_Lock);
+ cifs_num_waiters_inc(server);
+ wait_event(server->request_q,
+ atomic_read(&server->credits) > 0);
+ cifs_num_waiters_dec(server);
+ spin_lock(&GlobalMid_Lock);
+#endif /* CONFIG_CIFS_SMB2 */
} else {
if (server->tcpStatus == CifsExiting) {
spin_unlock(&GlobalMid_Lock);
@@ -305,8 +316,13 @@ cifs_wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
as they are allowed to block on server */
/* update # of requests on the wire to server */
- if (long_op != CIFS_BLOCKING_OP)
+ if (server->is_smb2 == false &&
+ long_op != CIFS_BLOCKING_OP)
atomic_inc(&server->inFlight);
+#ifdef CONFIG_CIFS_SMB2
+ else if (server->is_smb2)
+ atomic_dec(&server->credits);
+#endif
spin_unlock(&GlobalMid_Lock);
break;
}
--
1.7.1
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