[SCSI] iscsi: kill dtask mempools

Discovered by steven@hayter.me.uk and patch by michaelc@cs.wisc.edu

The dtask mempool is reserving 261120 items per session! Since we are now
sending headers with sendmsg there is no reason for the mempool and that
was causing us to us carzy amounts of mem. We can preallicate a header in
the r2t and task struct and reuse them

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index c591885..8083028 100644
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -118,11 +118,9 @@
 struct iscsi_data_task {
 	struct iscsi_data	hdr;			/* PDU */
 	char			hdrext[sizeof(__u32)];	/* Header-Digest */
-	struct list_head	item;			/* data queue item */
 	struct iscsi_buf	digestbuf;		/* digest buffer */
 	uint32_t		digest;			/* data digest */
 };
-#define ISCSI_DTASK_DEFAULT_MAX	ISCSI_SG_TABLESIZE * PAGE_SIZE / 512
 
 struct iscsi_tcp_mgmt_task {
 	struct iscsi_hdr	hdr;
@@ -144,7 +142,7 @@
 	int			data_count;	/* DATA-Out payload progress */
 	struct scatterlist	*sg;		/* per-R2T SG list */
 	int			solicit_datasn;
-	struct iscsi_data_task   *dtask;        /* which data task */
+	struct iscsi_data_task   dtask;        /* which data task */
 };
 
 struct iscsi_tcp_cmd_task {
@@ -167,14 +165,13 @@
 	struct iscsi_queue	r2tpool;
 	struct kfifo		*r2tqueue;
 	struct iscsi_r2t_info	**r2ts;
-	struct list_head	dataqueue;		/* Data-Out dataqueue */
-	mempool_t		*datapool;
 	uint32_t		datadigest;		/* for recover digest */
 	int			digest_count;
 	uint32_t		immdigest;		/* for imm data */
 	struct iscsi_buf	immbuf;			/* for imm data digest */
-	struct iscsi_data_task   *dtask;		/* data task in progress*/
-	int			digest_offset;		/* for partial buff digest */
+	struct iscsi_data_task	*dtask;		/* data task in progress*/
+	struct iscsi_data_task	unsol_dtask;	/* unsol data task */
+	int			digest_offset;	/* for partial buff digest */
 };
 
 #endif /* ISCSI_H */