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 | 11 +++++++----
fs/cifs/cifsproto.h | 3 +++
fs/cifs/cifssmb.c | 10 +++++-----
fs/cifs/connect.c | 14 ++++++--------
fs/cifs/misc.c | 18 ++++++++++++++++++
fs/cifs/transport.c | 36 ++++++++++++++++++++----------------
6 files changed, 59 insertions(+), 33 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index fb78bc9..d55de96 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -250,8 +250,9 @@ struct TCP_Server_Info {
bool noblocksnd; /* use blocking sendmsg */
bool noautotune; /* do not autotune send buf sizes */
bool tcp_nodelay;
+ int credits; /* send no more requests at once */
unsigned int in_flight; /* number of requests on the wire to server */
- spinlock_t req_lock; /* protect the value above */
+ spinlock_t req_lock; /* protect the two values above */
struct mutex srv_mutex;
struct task_struct *tsk;
char server_GUID[16];
@@ -314,12 +315,14 @@ in_flight(struct TCP_Server_Info *server)
return num;
}
-static inline void
-dec_in_flight(struct TCP_Server_Info *server)
+static inline bool
+has_credits(struct TCP_Server_Info *server)
{
+ int num;
spin_lock(&server->req_lock);
- server->in_flight--;
+ num = server->credits;
spin_unlock(&server->req_lock);
+ return num > 0;
}
/*
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 6f4e243..47a769e 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -88,6 +88,9 @@ extern int SendReceiveBlockingLock(const unsigned int xid,
struct smb_hdr *in_buf ,
struct smb_hdr *out_buf,
int *bytes_returned);
+extern void cifs_add_credits(struct TCP_Server_Info *server,
+ const unsigned int add);
+extern void cifs_set_credits(struct TCP_Server_Info *server, const int val);
extern int checkSMB(struct smb_hdr *smb, __u16 mid, unsigned int length);
extern bool is_valid_oplock_break(struct smb_hdr *smb,
struct TCP_Server_Info *);
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index d7cbcfa..08c84a1 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -461,7 +461,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifs_ses *ses)
server->maxReq = min_t(unsigned int,
le16_to_cpu(rsp->MaxMpxCount),
cifs_max_pending);
- server->oplocks = server->maxReq > 1 ? enable_oplocks : false;
+ cifs_set_credits(server, server->maxReq);
server->maxBuf = le16_to_cpu(rsp->MaxBufSize);
server->max_vcs = le16_to_cpu(rsp->MaxNumberVcs);
/* even though we do not use raw we might as well set this
@@ -569,7 +569,7 @@ CIFSSMBNegotiate(unsigned int xid, struct cifs_ses *ses)
little endian */
server->maxReq = min_t(unsigned int, le16_to_cpu(pSMBr->MaxMpxCount),
cifs_max_pending);
- server->oplocks = server->maxReq > 1 ? enable_oplocks : false;
+ cifs_set_credits(server, server->maxReq);
/* probably no need to store and check maxvcs */
server->maxBuf = le32_to_cpu(pSMBr->MaxBufferSize);
server->max_rw = le32_to_cpu(pSMBr->MaxRawSize);
@@ -721,7 +721,7 @@ cifs_echo_callback(struct mid_q_entry *mid)
struct TCP_Server_Info *server = mid->callback_data;
DeleteMidQEntry(mid);
- dec_in_flight(server);
+ cifs_add_credits(server, 1);
wake_up(&server->request_q);
}
@@ -1674,7 +1674,7 @@ cifs_readv_callback(struct mid_q_entry *mid)
queue_work(system_nrt_wq, &rdata->work);
DeleteMidQEntry(mid);
- dec_in_flight(server);
+ cifs_add_credits(server, 1);
wake_up(&server->request_q);
}
@@ -2115,7 +2115,7 @@ cifs_writev_callback(struct mid_q_entry *mid)
queue_work(system_nrt_wq, &wdata->work);
DeleteMidQEntry(mid);
- dec_in_flight(tcon->ses->server);
+ cifs_add_credits(tcon->ses->server, 1);
wake_up(&tcon->ses->server->request_q);
}
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a7627f2..f3a0c49 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -642,14 +642,10 @@ static void clean_demultiplex_info(struct TCP_Server_Info *server)
spin_unlock(&GlobalMid_Lock);
wake_up_all(&server->response_q);
- /* Check if we have blocked requests that need to free. */
+ /* check if we have blocked requests that need to free */
spin_lock(&server->req_lock);
- if (server->in_flight >= server->maxReq)
- server->in_flight = server->maxReq - 1;
- /*
- * We do not want to set the max_pending too low or we could end up
- * with the counter going negative.
- */
+ if (server->credits <= 0)
+ server->credits = 1;
spin_unlock(&server->req_lock);
/*
* Although there should not be any requests blocked on this queue it
@@ -1906,7 +1902,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
tcp_ses->noautotune = volume_info->noautotune;
tcp_ses->tcp_nodelay = volume_info->sockopt_tcp_nodelay;
tcp_ses->in_flight = 0;
- tcp_ses->maxReq = 1; /* enough to send negotiate request */
+ tcp_ses->credits = 1;
init_waitqueue_head(&tcp_ses->response_q);
init_waitqueue_head(&tcp_ses->request_q);
INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
@@ -3756,9 +3752,11 @@ int cifs_negotiate_protocol(unsigned int xid, struct cifs_ses *ses)
if (server->maxBuf != 0)
return 0;
+ cifs_set_credits(server, 1);
rc = CIFSSMBNegotiate(xid, ses);
if (rc == -EAGAIN) {
/* retry only once on 1st time connection */
+ cifs_set_credits(server, 1);
rc = CIFSSMBNegotiate(xid, ses);
if (rc == -EAGAIN)
rc = -EHOSTDOWN;
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 703ef5c..5dc936b 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -690,3 +690,21 @@ backup_cred(struct cifs_sb_info *cifs_sb)
return false;
}
+
+void
+cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add)
+{
+ spin_lock(&server->req_lock);
+ server->credits += add;
+ server->in_flight--;
+ spin_unlock(&server->req_lock);
+}
+
+void
+cifs_set_credits(struct TCP_Server_Info *server, const int val)
+{
+ spin_lock(&server->req_lock);
+ server->credits = val;
+ server->oplocks = val > 1 ? enable_oplocks : false;
+ spin_unlock(&server->req_lock);
+}
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index e2673aa..e8a4fd3 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -262,16 +262,16 @@ wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
if (long_op == CIFS_ASYNC_OP) {
/* oplock breaks must not be held up */
server->in_flight++;
+ server->credits--;
spin_unlock(&server->req_lock);
return 0;
}
while (1) {
- if (server->in_flight >= server->maxReq) {
+ if (server->credits <= 0) {
spin_unlock(&server->req_lock);
cifs_num_waiters_inc(server);
- wait_event(server->request_q,
- in_flight(server) < server->maxReq);
+ wait_event(server->request_q, has_credits(server));
cifs_num_waiters_dec(server);
spin_lock(&server->req_lock);
} else {
@@ -280,12 +280,16 @@ wait_for_free_request(struct TCP_Server_Info *server, const int long_op)
return -ENOENT;
}
- /* can not count locking commands against total
- as they are allowed to block on server */
+ /*
+ * Can not count locking commands against total
+ * 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) {
+ server->credits--;
server->in_flight++;
+ }
spin_unlock(&server->req_lock);
break;
}
@@ -360,7 +364,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
mid = AllocMidQEntry(hdr, server);
if (mid == NULL) {
mutex_unlock(&server->srv_mutex);
- dec_in_flight(server);
+ cifs_add_credits(server, 1);
wake_up(&server->request_q);
return -ENOMEM;
}
@@ -393,7 +397,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
return rc;
out_err:
delete_mid(mid);
- dec_in_flight(server);
+ cifs_add_credits(server, 1);
wake_up(&server->request_q);
return rc;
}
@@ -565,7 +569,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
mutex_unlock(&ses->server->srv_mutex);
cifs_small_buf_release(in_buf);
/* Update # of requests on wire to server */
- dec_in_flight(ses->server);
+ cifs_add_credits(ses->server, 1);
wake_up(&ses->server->request_q);
return rc;
}
@@ -602,7 +606,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
midQ->callback = DeleteMidQEntry;
spin_unlock(&GlobalMid_Lock);
cifs_small_buf_release(in_buf);
- dec_in_flight(ses->server);
+ cifs_add_credits(ses->server, 1);
wake_up(&ses->server->request_q);
return rc;
}
@@ -613,7 +617,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
rc = cifs_sync_mid_result(midQ, ses->server);
if (rc != 0) {
- dec_in_flight(ses->server);
+ cifs_add_credits(ses->server, 1);
wake_up(&ses->server->request_q);
return rc;
}
@@ -638,7 +642,7 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
midQ->resp_buf = NULL;
out:
delete_mid(midQ);
- dec_in_flight(ses->server);
+ cifs_add_credits(ses->server, 1);
wake_up(&ses->server->request_q);
return rc;
@@ -689,7 +693,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
if (rc) {
mutex_unlock(&ses->server->srv_mutex);
/* Update # of requests on wire to server */
- dec_in_flight(ses->server);
+ cifs_add_credits(ses->server, 1);
wake_up(&ses->server->request_q);
return rc;
}
@@ -722,7 +726,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
/* no longer considered to be "in-flight" */
midQ->callback = DeleteMidQEntry;
spin_unlock(&GlobalMid_Lock);
- dec_in_flight(ses->server);
+ cifs_add_credits(ses->server, 1);
wake_up(&ses->server->request_q);
return rc;
}
@@ -731,7 +735,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
rc = cifs_sync_mid_result(midQ, ses->server);
if (rc != 0) {
- dec_in_flight(ses->server);
+ cifs_add_credits(ses->server, 1);
wake_up(&ses->server->request_q);
return rc;
}
@@ -748,7 +752,7 @@ SendReceive(const unsigned int xid, struct cifs_ses *ses,
rc = cifs_check_receive(midQ, ses->server, 0);
out:
delete_mid(midQ);
- dec_in_flight(ses->server);
+ cifs_add_credits(ses->server, 1);
wake_up(&ses->server->request_q);
return rc;
--
1.7.1
--
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