From: Shlomo Pongratz <shlomop@xxxxxxxxxxxx>
Restructure the iscsi_tcp_r2t_rsp routine in order to avoid allocating
r2t from r2tpool.queue and returning it back in case the parameters
rhdr->data_length and or rhdr->data_offset prohibit the requing.
Since the values of these parameters are known prior to the allocation,
we can pre-check and thus avoid futile allocations.
Signed-off-by: Shlomo Pongratz <shlomop@xxxxxxxxxxxx>
Signed-off-by: Or Gerlitz <ogerlitz@xxxxxxxxxxxx>
Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx>
---
drivers/scsi/libiscsi_tcp.c | 43 ++++++++++++++++++++++---------------------
1 files changed, 22 insertions(+), 21 deletions(-)
diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index 1d58d53..7f59073 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -529,6 +529,8 @@ static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
struct iscsi_r2t_rsp *rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
struct iscsi_r2t_info *r2t;
int r2tsn = be32_to_cpu(rhdr->r2tsn);
+ u32 data_length;
+ u32 data_offset;
int rc;
if (tcp_conn->in.datalen) {
@@ -554,40 +556,39 @@ static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
return 0;
}
- rc = kfifo_out(&tcp_task->r2tpool.queue, (void*)&r2t, sizeof(void*));
- if (!rc) {
- iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. "
- "Target has sent more R2Ts than it "
- "negotiated for or driver has leaked.\n");
- return ISCSI_ERR_PROTO;
- }
-
- r2t->exp_statsn = rhdr->statsn;
- r2t->data_length = be32_to_cpu(rhdr->data_length);
- if (r2t->data_length == 0) {
+ data_length = be32_to_cpu(rhdr->data_length);
+ if (data_length == 0) {
iscsi_conn_printk(KERN_ERR, conn,
"invalid R2T with zero data len\n");
- kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t,
- sizeof(void*));
return ISCSI_ERR_DATALEN;
}
- if (r2t->data_length > session->max_burst)
+ if (data_length > session->max_burst)
ISCSI_DBG_TCP(conn, "invalid R2T with data len %u and max "
"burst %u. Attempting to execute request.\n",
- r2t->data_length, session->max_burst);
+ data_length, session->max_burst);
- r2t->data_offset = be32_to_cpu(rhdr->data_offset);
- if (r2t->data_offset + r2t->data_length > scsi_out(task->sc)->length) {
+ data_offset = be32_to_cpu(rhdr->data_offset);
+ if (data_offset + data_length > scsi_out(task->sc)->length) {
iscsi_conn_printk(KERN_ERR, conn,
"invalid R2T with data len %u at offset %u "
- "and total length %d\n", r2t->data_length,
- r2t->data_offset, scsi_out(task->sc)->length);
- kfifo_in(&tcp_task->r2tpool.queue, (void*)&r2t,
- sizeof(void*));
+ "and total length %d\n", data_length,
+ data_offset, scsi_out(task->sc)->length);
return ISCSI_ERR_DATALEN;
}
+ rc = kfifo_out(&tcp_task->r2tpool.queue, (void*)&r2t, sizeof(void*));
+ if (!rc) {
+ iscsi_conn_printk(KERN_ERR, conn, "Could not allocate R2T. "
+ "Target has sent more R2Ts than it "
+ "negotiated for or driver has leaked.\n");
+ return ISCSI_ERR_PROTO;
+ }
+
+ r2t->exp_statsn = rhdr->statsn;
+ r2t->data_length = data_length;
+ r2t->data_offset = data_offset;
+
r2t->ttt = rhdr->ttt; /* no flip */
r2t->datasn = 0;
r2t->sent = 0;
--
1.7.1
--
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