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[SCSI] libiscsi: handle immediate command rejections

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If we sent multiple pdus as immediate the target could be
rejecting some and we have just been dropping the rejection
notification. This adds code to handle nop-out rejections,
so if a nop-out was sent as a ping and rejected we do not
mark the connection bad. Instead we just clean up the timers
since we have pdu making a rount trip we know the connection
is good.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
This commit is contained in:
Mike Christie 2009-08-20 15:10:59 -05:00 committed by James Bottomley
parent d3305f3407
commit 8afa1439fc
1 changed files with 89 additions and 21 deletions
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110
drivers/scsi/libiscsi.c
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@ -857,27 +857,102 @@ static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
}
}
static int iscsi_nop_out_rsp(struct iscsi_task *task,
struct iscsi_nopin *nop, char *data, int datalen)
{
struct iscsi_conn *conn = task->conn;
int rc = 0;
if (conn->ping_task != task) {
/*
* If this is not in response to one of our
* nops then it must be from userspace.
*/
if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
data, datalen))
rc = ISCSI_ERR_CONN_FAILED;
} else
mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
return rc;
}
static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
char *data, int datalen)
{
struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
struct iscsi_hdr rejected_pdu;
int opcode, rc = 0;
conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
if (reject->reason == ISCSI_REASON_DATA_DIGEST_ERROR) {
if (ntoh24(reject->dlength) > datalen)
return ISCSI_ERR_PROTO;
if (ntoh24(reject->dlength) >= sizeof(struct iscsi_hdr)) {
memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
iscsi_conn_printk(KERN_ERR, conn,
"pdu (op 0x%x) rejected "
"due to DataDigest error.\n",
rejected_pdu.opcode);
}
if (ntoh24(reject->dlength) > datalen ||
ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
"pdu. Invalid data length (pdu dlength "
"%u, datalen %d\n", ntoh24(reject->dlength),
datalen);
return ISCSI_ERR_PROTO;
}
return 0;
memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
switch (reject->reason) {
case ISCSI_REASON_DATA_DIGEST_ERROR:
iscsi_conn_printk(KERN_ERR, conn,
"pdu (op 0x%x itt 0x%x) rejected "
"due to DataDigest error.\n",
rejected_pdu.itt, opcode);
break;
case ISCSI_REASON_IMM_CMD_REJECT:
iscsi_conn_printk(KERN_ERR, conn,
"pdu (op 0x%x itt 0x%x) rejected. Too many "
"immediate commands.\n",
rejected_pdu.itt, opcode);
/*
* We only send one TMF at a time so if the target could not
* handle it, then it should get fixed (RFC mandates that
* a target can handle one immediate TMF per conn).
*
* For nops-outs, we could have sent more than one if
* the target is sending us lots of nop-ins
*/
if (opcode != ISCSI_OP_NOOP_OUT)
return 0;
if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG))
/*
* nop-out in response to target's nop-out rejected.
* Just resend.
*/
iscsi_send_nopout(conn,
(struct iscsi_nopin*)&rejected_pdu);
else {
struct iscsi_task *task;
/*
* Our nop as ping got dropped. We know the target
* and transport are ok so just clean up
*/
task = iscsi_itt_to_task(conn, rejected_pdu.itt);
if (!task) {
iscsi_conn_printk(KERN_ERR, conn,
"Invalid pdu reject. Could "
"not lookup rejected task.\n");
rc = ISCSI_ERR_BAD_ITT;
} else
rc = iscsi_nop_out_rsp(task,
(struct iscsi_nopin*)&rejected_pdu,
NULL, 0);
}
break;
default:
iscsi_conn_printk(KERN_ERR, conn,
"pdu (op 0x%x itt 0x%x) rejected. Reason "
"code 0x%x\n", rejected_pdu.itt,
rejected_pdu.opcode, reject->reason);
break;
}
return rc;
}
/**
@ -1038,15 +1113,8 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
}
conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
if (conn->ping_task != task)
/*
* If this is not in response to one of our
* nops then it must be from userspace.
*/
goto recv_pdu;
mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
data, datalen);
break;
default:
rc = ISCSI_ERR_BAD_OPCODE;