Commit 8a26f0f7 authored by Pavel Shilovsky's avatar Pavel Shilovsky Committed by Steve French
Browse files

CIFS: Fix credits calculation for cancelled requests 



If a request is cancelled, we can't assume that the server returns
1 credit back. Instead we need to wait for a response and process
the number of credits granted by the server.

Create a separate mid callback for cancelled request, parse the number
of credits in a response buffer and add them to the client's credits.
If the didn't get a response (no response buffer available) assume
0 credits granted. The latter most probably happens together with
session reconnect, so the client's credits are adjusted anyway.

Signed-off-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent b9a74cde

fs/cifs/cifsglob.h

+1 −0
Original line number Diff line number Diff line
@@ -1438,6 +1438,7 @@ struct mid_q_entry { 
	int mid_state;	/* wish this were enum but can not pass to wait_event */

	unsigned int mid_flags;

	__le16 command;		/* smb command code */

	unsigned int optype;	/* operation type */

	bool large_buf:1;	/* if valid response, is pointer to large buf */

	bool multiRsp:1;	/* multiple trans2 responses for one request  */

	bool multiEnd:1;	/* both received */

fs/cifs/transport.c

+26 −2
Original line number Diff line number Diff line
@@ -787,6 +787,24 @@ cifs_noop_callback(struct mid_q_entry *mid) 
{

}



static void

cifs_cancelled_callback(struct mid_q_entry *mid)

{

	struct TCP_Server_Info *server = mid->server;

	unsigned int optype = mid->optype;

	unsigned int credits_received = 0;



	if (mid->mid_state == MID_RESPONSE_RECEIVED) {

		if (mid->resp_buf)

			credits_received = server->ops->get_credits(mid);

		else

			cifs_dbg(FYI, "Bad state for cancelled MID\n");

	}



	DeleteMidQEntry(mid);

	add_credits(server, credits_received, optype);

}



int

compound_send_recv(const unsigned int xid, struct cifs_ses *ses,

		   const int flags, const int num_rqst, struct smb_rqst *rqst,
@@ -862,6 +880,7 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses, 
		}



		midQ[i]->mid_state = MID_REQUEST_SUBMITTED;

		midQ[i]->optype = optype;

		/*

		 * We don't invoke the callback compounds unless it is the last

		 * request.
@@ -896,15 +915,20 @@ compound_send_recv(const unsigned int xid, struct cifs_ses *ses, 


	for (i = 0; i < num_rqst; i++) {

		rc = wait_for_response(ses->server, midQ[i]);

		if (rc != 0)

			break;

	}

	if (rc != 0) {

		for (; i < num_rqst; i++) {

			cifs_dbg(VFS, "Cancelling wait for mid %llu cmd: %d\n",

				 midQ[i]->mid, le16_to_cpu(midQ[i]->command));

			send_cancel(ses->server, &rqst[i], midQ[i]);

			spin_lock(&GlobalMid_Lock);

			if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {

				midQ[i]->mid_flags |= MID_WAIT_CANCELLED;

				midQ[i]->callback = DeleteMidQEntry;

				midQ[i]->callback = cifs_cancelled_callback;

				cancelled_mid[i] = true;

				credits[i] = 0;

			}

			spin_unlock(&GlobalMid_Lock);

		}

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