Commit ddc8cf8f authored by Jeff Layton's avatar Jeff Layton Committed by Steve French
Browse files

cifs: move locked sections out of DeleteMidQEntry and AllocMidQEntry 



In later patches, we're going to need to have finer-grained control
over the addition and removal of these structs from the pending_mid_q
and we'll need to be able to call the destructor while holding the
spinlock. Move the locked sections out of both routines and into
the callers. Fix up current callers of DeleteMidQEntry to call a new
routine that dequeues the entry and then destroys it.

Reviewed-by: default avatarSuresh Jayaraman <sjayaraman@suse.de>
Reviewed-by: default avatarPavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: default avatarJeff Layton <jlayton@redhat.com>
Signed-off-by: default avatarSteve French <sfrench@us.ibm.com>
parent 8097531a

fs/cifs/transport.c

+24 −17
Original line number Diff line number Diff line
@@ -63,9 +63,6 @@ AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server) 


	atomic_inc(&midCount);

	temp->midState = MID_REQUEST_ALLOCATED;

	spin_lock(&GlobalMid_Lock);

	list_add_tail(&temp->qhead, &server->pending_mid_q);

	spin_unlock(&GlobalMid_Lock);

	return temp;

}
@@ -75,10 +72,7 @@ DeleteMidQEntry(struct mid_q_entry *midEntry) 
#ifdef CONFIG_CIFS_STATS2

	unsigned long now;

#endif

	spin_lock(&GlobalMid_Lock);

	midEntry->midState = MID_FREE;

	list_del(&midEntry->qhead);

	spin_unlock(&GlobalMid_Lock);

	atomic_dec(&midCount);

	if (midEntry->largeBuf)

		cifs_buf_release(midEntry->resp_buf);
@@ -103,6 +97,16 @@ DeleteMidQEntry(struct mid_q_entry *midEntry) 
	mempool_free(midEntry, cifs_mid_poolp);

}



static void

delete_mid(struct mid_q_entry *mid)

{

	spin_lock(&GlobalMid_Lock);

	list_del(&mid->qhead);

	spin_unlock(&GlobalMid_Lock);



	DeleteMidQEntry(mid);

}



static int

smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)

{
@@ -308,6 +312,9 @@ static int allocate_mid(struct cifsSesInfo *ses, struct smb_hdr *in_buf, 
	*ppmidQ = AllocMidQEntry(in_buf, ses->server);

	if (*ppmidQ == NULL)

		return -ENOMEM;

	spin_lock(&GlobalMid_Lock);

	list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);

	spin_unlock(&GlobalMid_Lock);

	return 0;

}
@@ -508,7 +515,7 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, 
			}

		}

		spin_unlock(&GlobalMid_Lock);

		DeleteMidQEntry(midQ);

		delete_mid(midQ);

		/* Update # of requests on wire to server */

		atomic_dec(&ses->server->inFlight);

		wake_up(&ses->server->request_q);
@@ -564,14 +571,14 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, 
		if ((flags & CIFS_NO_RESP) == 0)

			midQ->resp_buf = NULL;  /* mark it so buf will

						   not be freed by

						   DeleteMidQEntry */

						   delete_mid */

	} else {

		rc = -EIO;

		cFYI(1, "Bad MID state?");

	}



out:

	DeleteMidQEntry(midQ);

	delete_mid(midQ);

	atomic_dec(&ses->server->inFlight);

	wake_up(&ses->server->request_q);
@@ -699,7 +706,7 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses, 
			}

		}

		spin_unlock(&GlobalMid_Lock);

		DeleteMidQEntry(midQ);

		delete_mid(midQ);

		/* Update # of requests on wire to server */

		atomic_dec(&ses->server->inFlight);

		wake_up(&ses->server->request_q);
@@ -755,7 +762,7 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses, 
	}



out:

	DeleteMidQEntry(midQ);

	delete_mid(midQ);

	atomic_dec(&ses->server->inFlight);

	wake_up(&ses->server->request_q);
@@ -863,7 +870,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, 


	rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);

	if (rc) {

		DeleteMidQEntry(midQ);

		delete_mid(midQ);

		mutex_unlock(&ses->server->srv_mutex);

		return rc;

	}
@@ -880,7 +887,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, 
	mutex_unlock(&ses->server->srv_mutex);



	if (rc < 0) {

		DeleteMidQEntry(midQ);

		delete_mid(midQ);

		return rc;

	}
@@ -902,7 +909,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, 


			rc = send_nt_cancel(tcon, in_buf, midQ);

			if (rc) {

				DeleteMidQEntry(midQ);

				delete_mid(midQ);

				return rc;

			}

		} else {
@@ -914,7 +921,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, 
			/* If we get -ENOLCK back the lock may have

			   already been removed. Don't exit in this case. */

			if (rc && rc != -ENOLCK) {

				DeleteMidQEntry(midQ);

				delete_mid(midQ);

				return rc;

			}

		}
@@ -951,7 +958,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, 
			}

		}

		spin_unlock(&GlobalMid_Lock);

		DeleteMidQEntry(midQ);

		delete_mid(midQ);

		return rc;

	}
@@ -1001,7 +1008,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, 
		BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));



out:

	DeleteMidQEntry(midQ);

	delete_mid(midQ);

	if (rstart && rc == -EACCES)

		return -ERESTARTSYS;

	return rc;

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