CIFS: Fix credit computation for compounded requests (8544f4aa) · Commits · 戴 / test

fs/cifs/transport.c

+41 −18

Original line number	Diff line number	Diff line
		@@ -795,7 +795,8 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
		int i, j, rc = 0;
		int timeout, optype;
		struct mid_q_entry *midQ[MAX_COMPOUND];
		unsigned int credits = 0;
		bool cancelled_mid[MAX_COMPOUND] = {false};
		unsigned int credits[MAX_COMPOUND] = {0};
		char *buf;

		timeout = flags & CIFS_TIMEOUT_MASK;
		@@ -813,13 +814,31 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
		return -ENOENT;

		/*
		* Ensure that we do not send more than 50 overlapping requests
		* to the same server. We may make this configurable later or
		* use ses->maxReq.
		* Ensure we obtain 1 credit per request in the compound chain.
		* It can be optimized further by waiting for all the credits
		* at once but this can wait long enough if we don't have enough
		* credits due to some heavy operations in progress or the server
		* not granting us much, so a fallback to the current approach is
		* needed anyway.
		*/
		for (i = 0; i < num_rqst; i++) {
		rc = wait_for_free_request(ses->server, timeout, optype);
		if (rc)
		if (rc) {
		/*
		* We haven't sent an SMB packet to the server yet but
		* we already obtained credits for i requests in the
		* compound chain - need to return those credits back
		* for future use. Note that we need to call add_credits
		* multiple times to match the way we obtained credits
		* in the first place and to account for in flight
		* requests correctly.
		*/
		for (j = 0; j < i; j++)
		add_credits(ses->server, 1, optype);
		return rc;
		}
		credits[i] = 1;
		}

		/*
		* Make sure that we sign in the same order that we send on this socket
		@@ -835,8 +854,10 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
		for (j = 0; j < i; j++)
		cifs_delete_mid(midQ[j]);
		mutex_unlock(&ses->server->srv_mutex);

		/* Update # of requests on wire to server */
		add_credits(ses->server, 1, optype);
		for (j = 0; j < num_rqst; j++)
		add_credits(ses->server, credits[j], optype);
		return PTR_ERR(midQ[i]);
		}

		@@ -883,17 +904,16 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
		if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
		midQ[i]->mid_flags \|= MID_WAIT_CANCELLED;
		midQ[i]->callback = DeleteMidQEntry;
		spin_unlock(&GlobalMid_Lock);
		add_credits(ses->server, 1, optype);
		return rc;
		cancelled_mid[i] = true;
		}
		spin_unlock(&GlobalMid_Lock);
		}
		}

		for (i = 0; i < num_rqst; i++)
		if (midQ[i]->resp_buf)
		credits += ses->server->ops->get_credits(midQ[i]);
		if (!cancelled_mid[i] && midQ[i]->resp_buf
		&& (midQ[i]->mid_state == MID_RESPONSE_RECEIVED))
		credits[i] = ses->server->ops->get_credits(midQ[i]);

		for (i = 0; i < num_rqst; i++) {
		if (rc < 0)
		@@ -901,8 +921,9 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses,

		rc = cifs_sync_mid_result(midQ[i], ses->server);
		if (rc != 0) {
		add_credits(ses->server, credits, optype);
		return rc;
		/* mark this mid as cancelled to not free it below */
		cancelled_mid[i] = true;
		goto out;
		}

		if (!midQ[i]->resp_buf \|\|
		@@ -949,9 +970,11 @@ out:
		* This is prevented above by using a noop callback that will not
		* wake this thread except for the very last PDU.
		*/
		for (i = 0; i < num_rqst; i++)
		for (i = 0; i < num_rqst; i++) {
		if (!cancelled_mid[i])
		cifs_delete_mid(midQ[i]);
		add_credits(ses->server, credits, optype);
		add_credits(ses->server, credits[i], optype);
		}

		return rc;
		}

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