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authorMike Christie <michaelc@cs.wisc.edu>2008-09-24 11:46:09 -0500
committerJames Bottomley <James.Bottomley@HansenPartnership.com>2008-10-13 09:28:58 -0400
commit1d9edf0270cb5a434d32e95279ce9493581906b3 (patch)
tree1b54cdd2c8b18e78a788d7f1f3c17c7b73043c24 /drivers/scsi/iscsi_tcp.c
parentcbdc14459bd7d99d20341ec057b8f4ffab2a7fb6 (diff)
downloadlinux-1d9edf0270cb5a434d32e95279ce9493581906b3.tar.bz2
[SCSI] libiscsi: fix data corruption when target has to resend data-in packets
iscsi_tcp was updating the exp_statsn (exp_statsn acknowledges status and tells the target it is ok to let the resources for a iscsi pdu to be reused) before it got all the data for pdu read into OS buffers. Data corruption was occuring if something happens to a packet and the network layer requests a retransmit, and the initiator has told the target about the udpated exp_statsn ack, then the target may be sending data from a buffer it has reused for a new iscsi pdu. This fixes the problem by having the LLD (iscsi_tcp in this case) just handle the transferring of data, and has libiscsi handle the processing of status (libiscsi completion processing is done after LLD data transfers are complete). Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Diffstat (limited to 'drivers/scsi/iscsi_tcp.c')
-rw-r--r--drivers/scsi/iscsi_tcp.c29
1 files changed, 5 insertions, 24 deletions
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 2a2f0094570f..e960f00da93a 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -523,22 +523,20 @@ iscsi_tcp_cleanup_task(struct iscsi_conn *conn, struct iscsi_task *task)
}
/**
- * iscsi_data_rsp - SCSI Data-In Response processing
+ * iscsi_data_in - SCSI Data-In Response processing
* @conn: iscsi connection
* @task: scsi command task
**/
static int
-iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
+iscsi_data_in(struct iscsi_conn *conn, struct iscsi_task *task)
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_tcp_task *tcp_task = task->dd_data;
struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)tcp_conn->in.hdr;
- struct iscsi_session *session = conn->session;
- struct scsi_cmnd *sc = task->sc;
int datasn = be32_to_cpu(rhdr->datasn);
- unsigned total_in_length = scsi_in(sc)->length;
+ unsigned total_in_length = scsi_in(task->sc)->length;
- iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
+ iscsi_update_cmdsn(conn->session, (struct iscsi_nopin*)rhdr);
if (tcp_conn->in.datalen == 0)
return 0;
@@ -558,23 +556,6 @@ iscsi_data_rsp(struct iscsi_conn *conn, struct iscsi_task *task)
return ISCSI_ERR_DATA_OFFSET;
}
- if (rhdr->flags & ISCSI_FLAG_DATA_STATUS) {
- sc->result = (DID_OK << 16) | rhdr->cmd_status;
- conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
- if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
- ISCSI_FLAG_DATA_OVERFLOW)) {
- int res_count = be32_to_cpu(rhdr->residual_count);
-
- if (res_count > 0 &&
- (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
- res_count <= total_in_length))
- scsi_in(sc)->resid = res_count;
- else
- sc->result = (DID_BAD_TARGET << 16) |
- rhdr->cmd_status;
- }
- }
-
conn->datain_pdus_cnt++;
return 0;
}
@@ -774,7 +755,7 @@ iscsi_tcp_hdr_dissect(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
if (!task)
rc = ISCSI_ERR_BAD_ITT;
else
- rc = iscsi_data_rsp(conn, task);
+ rc = iscsi_data_in(conn, task);
if (rc) {
spin_unlock(&conn->session->lock);
break;