[SCSI] iscsi: fix writepsace race
We can race and misset the suspend bit if iscsi_write_space is
called then iscsi_send returns with a failure indicating
there is no space.
To handle this this patch returns a error upwards allowing xmitworker
to decide if we need to try and transmit again. For the no
write space case xmitworker will not retry, and instead
let iscsi_write_space queue it back up if needed (this relies
on the work queue code to properly requeue us if needed).
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.c b/drivers/scsi/iscsi_tcp.c
index 2abda80..7fa8593 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -1006,7 +1006,6 @@
tcp_conn->old_write_space(sk);
debug_tcp("iscsi_write_space: cid %d\n", conn->id);
- clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
scsi_queue_work(conn->session->host, &conn->xmitwork);
}
@@ -1056,7 +1055,7 @@
{
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct socket *sk = tcp_conn->sock;
- int offset = buf->sg.offset + buf->sent;
+ int offset = buf->sg.offset + buf->sent, res;
/*
* if we got use_sg=0 or are sending something we kmallocd
@@ -1067,10 +1066,22 @@
* slab case.
*/
if (buf->use_sendmsg)
- return sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
+ res = sock_no_sendpage(sk, buf->sg.page, offset, size, flags);
else
- return tcp_conn->sendpage(sk, buf->sg.page, offset, size,
- flags);
+ res = tcp_conn->sendpage(sk, buf->sg.page, offset, size, flags);
+
+ if (res >= 0) {
+ conn->txdata_octets += res;
+ buf->sent += res;
+ return res;
+ }
+
+ tcp_conn->sendpage_failures_cnt++;
+ if (res == -EAGAIN)
+ res = -ENOBUFS;
+ else
+ iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+ return res;
}
/**
@@ -1085,7 +1096,6 @@
static inline int
iscsi_sendhdr(struct iscsi_conn *conn, struct iscsi_buf *buf, int datalen)
{
- struct iscsi_tcp_conn *tcp_conn;
int flags = 0; /* MSG_DONTWAIT; */
int res, size;
@@ -1097,17 +1107,10 @@
res = iscsi_send(conn, buf, size, flags);
debug_tcp("sendhdr %d bytes, sent %d res %d\n", size, buf->sent, res);
if (res >= 0) {
- conn->txdata_octets += res;
- buf->sent += res;
if (size != res)
return -EAGAIN;
return 0;
- } else if (res == -EAGAIN) {
- tcp_conn = conn->dd_data;
- tcp_conn->sendpage_failures_cnt++;
- set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
- } else if (res == -EPIPE)
- iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+ }
return res;
}
@@ -1126,7 +1129,6 @@
iscsi_sendpage(struct iscsi_conn *conn, struct iscsi_buf *buf,
int *count, int *sent)
{
- struct iscsi_tcp_conn *tcp_conn;
int flags = 0; /* MSG_DONTWAIT; */
int res, size;
@@ -1141,19 +1143,12 @@
debug_tcp("sendpage: %d bytes, sent %d left %d sent %d res %d\n",
size, buf->sent, *count, *sent, res);
if (res >= 0) {
- conn->txdata_octets += res;
- buf->sent += res;
*count -= res;
*sent += res;
if (size != res)
return -EAGAIN;
return 0;
- } else if (res == -EAGAIN) {
- tcp_conn = conn->dd_data;
- tcp_conn->sendpage_failures_cnt++;
- set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
- } else if (res == -EPIPE)
- iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+ }
return res;
}
@@ -1342,6 +1337,7 @@
iscsi_tcp_mtask_xmit(struct iscsi_conn *conn, struct iscsi_mgmt_task *mtask)
{
struct iscsi_tcp_mgmt_task *tcp_mtask = mtask->dd_data;
+ int rc;
debug_scsi("mtask deq [cid %d state %x itt 0x%x]\n",
conn->id, tcp_mtask->xmstate, mtask->itt);
@@ -1355,12 +1351,13 @@
conn->hdrdgst_en)
iscsi_hdr_digest(conn, &tcp_mtask->headbuf,
(u8*)tcp_mtask->hdrext);
- if (iscsi_sendhdr(conn, &tcp_mtask->headbuf,
- mtask->data_count)) {
+ rc = iscsi_sendhdr(conn, &tcp_mtask->headbuf,
+ mtask->data_count);
+ if (rc) {
tcp_mtask->xmstate |= XMSTATE_IMM_HDR;
if (mtask->data_count)
tcp_mtask->xmstate &= ~XMSTATE_IMM_DATA;
- return -EAGAIN;
+ return rc;
}
}
@@ -1371,10 +1368,13 @@
* Virtual buffer could be spreaded across multiple pages...
*/
do {
- if (iscsi_sendpage(conn, &tcp_mtask->sendbuf,
- &mtask->data_count, &tcp_mtask->sent)) {
+ int rc;
+
+ rc = iscsi_sendpage(conn, &tcp_mtask->sendbuf,
+ &mtask->data_count, &tcp_mtask->sent);
+ if (rc) {
tcp_mtask->xmstate |= XMSTATE_IMM_DATA;
- return -EAGAIN;
+ return rc;
}
} while (mtask->data_count);
}
@@ -1396,16 +1396,19 @@
handle_xmstate_r_hdr(struct iscsi_conn *conn,
struct iscsi_tcp_cmd_task *tcp_ctask)
{
+ int rc;
+
tcp_ctask->xmstate &= ~XMSTATE_R_HDR;
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
(u8*)tcp_ctask->hdrext);
- if (!iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0)) {
+ rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, 0);
+ if (!rc) {
BUG_ON(tcp_ctask->xmstate != XMSTATE_IDLE);
return 0; /* wait for Data-In */
}
tcp_ctask->xmstate |= XMSTATE_R_HDR;
- return -EAGAIN;
+ return rc;
}
static inline int
@@ -1413,16 +1416,16 @@
struct iscsi_cmd_task *ctask)
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
+ int rc;
tcp_ctask->xmstate &= ~XMSTATE_W_HDR;
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &tcp_ctask->headbuf,
(u8*)tcp_ctask->hdrext);
- if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count)) {
+ rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->imm_count);
+ if (rc)
tcp_ctask->xmstate |= XMSTATE_W_HDR;
- return -EAGAIN;
- }
- return 0;
+ return rc;
}
static inline int
@@ -1430,17 +1433,19 @@
struct iscsi_cmd_task *ctask)
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
+ int rc;
tcp_ctask->xmstate &= ~XMSTATE_DATA_DIGEST;
debug_tcp("resent data digest 0x%x\n", tcp_ctask->datadigest);
- if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
- &tcp_ctask->datadigest, 0)) {
+ rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
+ &tcp_ctask->datadigest, 0);
+ if (rc) {
tcp_ctask->xmstate |= XMSTATE_DATA_DIGEST;
debug_tcp("resent data digest 0x%x fail!\n",
tcp_ctask->datadigest);
- return -EAGAIN;
}
- return 0;
+
+ return rc;
}
static inline int
@@ -1448,6 +1453,7 @@
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+ int rc;
BUG_ON(!ctask->imm_count);
tcp_ctask->xmstate &= ~XMSTATE_IMM_DATA;
@@ -1458,8 +1464,9 @@
}
for (;;) {
- if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &ctask->imm_count,
- &tcp_ctask->sent)) {
+ rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
+ &ctask->imm_count, &tcp_ctask->sent);
+ if (rc) {
tcp_ctask->xmstate |= XMSTATE_IMM_DATA;
if (conn->datadgst_en) {
crypto_digest_final(tcp_conn->data_tx_tfm,
@@ -1467,7 +1474,7 @@
debug_tcp("tx imm sendpage fail 0x%x\n",
tcp_ctask->datadigest);
}
- return -EAGAIN;
+ return rc;
}
if (conn->datadgst_en)
crypto_digest_update(tcp_conn->data_tx_tfm,
@@ -1480,11 +1487,12 @@
}
if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
- if (iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
- &tcp_ctask->immdigest, 1)) {
+ rc = iscsi_digest_final_send(conn, ctask, &tcp_ctask->immbuf,
+ &tcp_ctask->immdigest, 1);
+ if (rc) {
debug_tcp("sending imm digest 0x%x fail!\n",
tcp_ctask->immdigest);
- return -EAGAIN;
+ return rc;
}
debug_tcp("sending imm digest 0x%x\n", tcp_ctask->immdigest);
}
@@ -1497,6 +1505,7 @@
{
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct iscsi_data_task *dtask;
+ int rc;
tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
if (tcp_ctask->xmstate & XMSTATE_UNS_INIT) {
@@ -1507,10 +1516,12 @@
(u8*)dtask->hdrext);
tcp_ctask->xmstate &= ~XMSTATE_UNS_INIT;
}
- if (iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count)) {
+
+ rc = iscsi_sendhdr(conn, &tcp_ctask->headbuf, ctask->data_count);
+ if (rc) {
tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
tcp_ctask->xmstate |= XMSTATE_UNS_HDR;
- return -EAGAIN;
+ return rc;
}
debug_scsi("uns dout [itt 0x%x dlen %d sent %d]\n",
@@ -1524,6 +1535,7 @@
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct iscsi_data_task *dtask = tcp_ctask->dtask;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
+ int rc;
BUG_ON(!ctask->data_count);
tcp_ctask->xmstate &= ~XMSTATE_UNS_DATA;
@@ -1536,8 +1548,9 @@
for (;;) {
int start = tcp_ctask->sent;
- if (iscsi_sendpage(conn, &tcp_ctask->sendbuf,
- &ctask->data_count, &tcp_ctask->sent)) {
+ rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf,
+ &ctask->data_count, &tcp_ctask->sent);
+ if (rc) {
ctask->unsol_count -= tcp_ctask->sent - start;
tcp_ctask->xmstate |= XMSTATE_UNS_DATA;
/* will continue with this ctask later.. */
@@ -1547,7 +1560,7 @@
debug_tcp("tx uns data fail 0x%x\n",
dtask->digest);
}
- return -EAGAIN;
+ return rc;
}
BUG_ON(tcp_ctask->sent > ctask->total_length);
@@ -1574,12 +1587,13 @@
*/
if (ctask->unsol_count) {
if (conn->datadgst_en) {
- if (iscsi_digest_final_send(conn, ctask,
+ rc = iscsi_digest_final_send(conn, ctask,
&dtask->digestbuf,
- &dtask->digest, 1)) {
+ &dtask->digest, 1);
+ if (rc) {
debug_tcp("send uns digest 0x%x fail\n",
dtask->digest);
- return -EAGAIN;
+ return rc;
}
debug_tcp("sending uns digest 0x%x, more uns\n",
dtask->digest);
@@ -1589,12 +1603,13 @@
}
if (conn->datadgst_en && !(tcp_ctask->xmstate & XMSTATE_W_PAD)) {
- if (iscsi_digest_final_send(conn, ctask,
+ rc = iscsi_digest_final_send(conn, ctask,
&dtask->digestbuf,
- &dtask->digest, 1)) {
+ &dtask->digest, 1);
+ if (rc) {
debug_tcp("send last uns digest 0x%x fail\n",
dtask->digest);
- return -EAGAIN;
+ return rc;
}
debug_tcp("sending uns digest 0x%x\n",dtask->digest);
}
@@ -1610,7 +1625,7 @@
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct iscsi_r2t_info *r2t = tcp_ctask->r2t;
struct iscsi_data_task *dtask = &r2t->dtask;
- int left;
+ int left, rc;
tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
tcp_ctask->dtask = dtask;
@@ -1626,7 +1641,8 @@
if (!r2t->data_count)
goto data_out_done;
- if (iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent)) {
+ rc = iscsi_sendpage(conn, &r2t->sendbuf, &r2t->data_count, &r2t->sent);
+ if (rc) {
tcp_ctask->xmstate |= XMSTATE_SOL_DATA;
/* will continue with this ctask later.. */
if (conn->datadgst_en) {
@@ -1634,7 +1650,7 @@
(u8 *)&dtask->digest);
debug_tcp("r2t data send fail 0x%x\n", dtask->digest);
}
- return -EAGAIN;
+ return rc;
}
BUG_ON(r2t->data_count < 0);
@@ -1661,12 +1677,13 @@
left = r2t->data_length - r2t->sent;
if (left) {
if (conn->datadgst_en) {
- if (iscsi_digest_final_send(conn, ctask,
+ rc = iscsi_digest_final_send(conn, ctask,
&dtask->digestbuf,
- &dtask->digest, 1)) {
+ &dtask->digest, 1);
+ if (rc) {
debug_tcp("send r2t data digest 0x%x"
"fail\n", dtask->digest);
- return -EAGAIN;
+ return rc;
}
debug_tcp("r2t data send digest 0x%x\n",
dtask->digest);
@@ -1683,11 +1700,12 @@
*/
BUG_ON(tcp_ctask->r2t_data_count - r2t->data_length < 0);
if (conn->datadgst_en) {
- if (iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
- &dtask->digest, 1)) {
+ rc = iscsi_digest_final_send(conn, ctask, &dtask->digestbuf,
+ &dtask->digest, 1);
+ if (rc) {
debug_tcp("send last r2t data digest 0x%x"
"fail\n", dtask->digest);
- return -EAGAIN;
+ return rc;
}
debug_tcp("r2t done dout digest 0x%x\n", dtask->digest);
}
@@ -1713,15 +1731,16 @@
struct iscsi_tcp_cmd_task *tcp_ctask = ctask->dd_data;
struct iscsi_tcp_conn *tcp_conn = conn->dd_data;
struct iscsi_data_task *dtask = tcp_ctask->dtask;
- int sent;
+ int sent, rc;
tcp_ctask->xmstate &= ~XMSTATE_W_PAD;
iscsi_buf_init_iov(&tcp_ctask->sendbuf, (char*)&tcp_ctask->pad,
tcp_ctask->pad_count);
- if (iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
- &sent)) {
+ rc = iscsi_sendpage(conn, &tcp_ctask->sendbuf, &tcp_ctask->pad_count,
+ &sent);
+ if (rc) {
tcp_ctask->xmstate |= XMSTATE_W_PAD;
- return -EAGAIN;
+ return rc;
}
if (conn->datadgst_en) {
@@ -1729,22 +1748,24 @@
&tcp_ctask->sendbuf.sg, 1);
/* imm data? */
if (!dtask) {
- if (iscsi_digest_final_send(conn, ctask,
+ rc = iscsi_digest_final_send(conn, ctask,
&tcp_ctask->immbuf,
- &tcp_ctask->immdigest, 1)) {
+ &tcp_ctask->immdigest, 1);
+ if (rc) {
debug_tcp("send padding digest 0x%x"
"fail!\n", tcp_ctask->immdigest);
- return -EAGAIN;
+ return rc;
}
debug_tcp("done with padding, digest 0x%x\n",
tcp_ctask->datadigest);
} else {
- if (iscsi_digest_final_send(conn, ctask,
+ rc = iscsi_digest_final_send(conn, ctask,
&dtask->digestbuf,
- &dtask->digest, 1)) {
+ &dtask->digest, 1);
+ if (rc) {
debug_tcp("send padding digest 0x%x"
"fail\n", dtask->digest);
- return -EAGAIN;
+ return rc;
}
debug_tcp("done with padding, digest 0x%x\n",
dtask->digest);
@@ -1769,10 +1790,8 @@
if (ctask->mtask)
return rc;
- if (tcp_ctask->xmstate & XMSTATE_R_HDR) {
- rc = handle_xmstate_r_hdr(conn, tcp_ctask);
- return rc;
- }
+ if (tcp_ctask->xmstate & XMSTATE_R_HDR)
+ return handle_xmstate_r_hdr(conn, tcp_ctask);
if (tcp_ctask->xmstate & XMSTATE_W_HDR) {
rc = handle_xmstate_w_hdr(conn, ctask);
@@ -1824,10 +1843,11 @@
if (conn->hdrdgst_en)
iscsi_hdr_digest(conn, &r2t->headbuf,
(u8*)r2t->dtask.hdrext);
- if (iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count)) {
+ rc = iscsi_sendhdr(conn, &r2t->headbuf, r2t->data_count);
+ if (rc) {
tcp_ctask->xmstate &= ~XMSTATE_SOL_DATA;
tcp_ctask->xmstate |= XMSTATE_SOL_HDR;
- return -EAGAIN;
+ return rc;
}
debug_scsi("sol dout [dsn %d itt 0x%x dlen %d sent %d]\n",