[3.13.y.z extended stable] Patch "iser-target: Add missing se_cmd put for WRITE_PENDING in tx_comp_err" has been added to staging queue
Kamal Mostafa
kamal at canonical.com
Thu May 1 19:17:53 UTC 2014
This is a note to let you know that I have just added a patch titled
iser-target: Add missing se_cmd put for WRITE_PENDING in tx_comp_err
to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue
This patch is scheduled to be released in version 3.13.11.1.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
------
>From 84a55168984720ea73150a12d2ec2947524dc89d Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab at linux-iscsi.org>
Date: Sun, 30 Mar 2014 15:50:03 -0700
Subject: iser-target: Add missing se_cmd put for WRITE_PENDING in tx_comp_err
commit 03e7848a64ed535a30f5d7fc6dede2d5a6a2534b upstream.
This patch fixes a bug where outstanding RDMA_READs with WRITE_PENDING
status require an extra target_put_sess_cmd() in isert_put_cmd() code
when called from isert_cq_tx_comp_err() + isert_cq_drain_comp_llist()
context during session shutdown.
The extra kref PUT is required so that transport_generic_free_cmd()
invokes the last target_put_sess_cmd() -> target_release_cmd_kref(),
which will complete(&se_cmd->cmd_wait_comp) the outstanding se_cmd
descriptor with WRITE_PENDING status, and awake the completion in
target_wait_for_sess_cmds() to invoke TFO->release_cmd().
The bug was manifesting itself in target_wait_for_sess_cmds() where
a se_cmd descriptor with WRITE_PENDING status would end up sleeping
indefinately.
Acked-by: Sagi Grimberg <sagig at mellanox.com>
Cc: Or Gerlitz <ogerlitz at mellanox.com>
Signed-off-by: Nicholas Bellinger <nab at linux-iscsi.org>
[ kamal: backport to 3.13 (context) ]
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
drivers/infiniband/ulp/isert/ib_isert.c | 37 +++++++++++++++++++++++----------
1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 3b7bfc7..3e3b2a1 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -1434,7 +1434,7 @@ isert_unreg_rdma_frwr(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn
}
static void
-isert_put_cmd(struct isert_cmd *isert_cmd)
+isert_put_cmd(struct isert_cmd *isert_cmd, bool comp_err)
{
struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
struct isert_conn *isert_conn = isert_cmd->conn;
@@ -1450,8 +1450,21 @@ isert_put_cmd(struct isert_cmd *isert_cmd)
list_del_init(&cmd->i_conn_node);
spin_unlock_bh(&conn->cmd_lock);
- if (cmd->data_direction == DMA_TO_DEVICE)
+ if (cmd->data_direction == DMA_TO_DEVICE) {
iscsit_stop_dataout_timer(cmd);
+ /*
+ * Check for special case during comp_err where
+ * WRITE_PENDING has been handed off from core,
+ * but requires an extra target_put_sess_cmd()
+ * before transport_generic_free_cmd() below.
+ */
+ if (comp_err &&
+ cmd->se_cmd.t_state == TRANSPORT_WRITE_PENDING) {
+ struct se_cmd *se_cmd = &cmd->se_cmd;
+
+ target_put_sess_cmd(se_cmd->se_sess, se_cmd);
+ }
+ }
device->unreg_rdma_mem(isert_cmd, isert_conn);
transport_generic_free_cmd(&cmd->se_cmd, 0);
@@ -1506,7 +1519,7 @@ isert_unmap_tx_desc(struct iser_tx_desc *tx_desc, struct ib_device *ib_dev)
static void
isert_completion_put(struct iser_tx_desc *tx_desc, struct isert_cmd *isert_cmd,
- struct ib_device *ib_dev)
+ struct ib_device *ib_dev, bool comp_err)
{
if (isert_cmd->pdu_buf_dma != 0) {
pr_debug("Calling ib_dma_unmap_single for isert_cmd->pdu_buf_dma\n");
@@ -1516,7 +1529,7 @@ isert_completion_put(struct iser_tx_desc *tx_desc, struct isert_cmd *isert_cmd,
}
isert_unmap_tx_desc(tx_desc, ib_dev);
- isert_put_cmd(isert_cmd);
+ isert_put_cmd(isert_cmd, comp_err);
}
static void
@@ -1560,14 +1573,14 @@ isert_do_control_comp(struct work_struct *work)
iscsit_tmr_post_handler(cmd, cmd->conn);
cmd->i_state = ISTATE_SENT_STATUS;
- isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev);
+ isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev, false);
break;
case ISTATE_SEND_REJECT:
pr_debug("Got isert_do_control_comp ISTATE_SEND_REJECT: >>>\n");
atomic_dec(&isert_conn->post_send_buf_count);
cmd->i_state = ISTATE_SENT_STATUS;
- isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev);
+ isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev, false);
break;
case ISTATE_SEND_LOGOUTRSP:
pr_debug("Calling iscsit_logout_post_handler >>>>>>>>>>>>>>\n");
@@ -1581,7 +1594,7 @@ isert_do_control_comp(struct work_struct *work)
case ISTATE_SEND_TEXTRSP:
atomic_dec(&isert_conn->post_send_buf_count);
cmd->i_state = ISTATE_SENT_STATUS;
- isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev);
+ isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev, false);
break;
default:
pr_err("Unknown do_control_comp i_state %d\n", cmd->i_state);
@@ -1612,7 +1625,7 @@ isert_response_completion(struct iser_tx_desc *tx_desc,
atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
cmd->i_state = ISTATE_SENT_STATUS;
- isert_completion_put(tx_desc, isert_cmd, ib_dev);
+ isert_completion_put(tx_desc, isert_cmd, ib_dev, false);
}
static void
@@ -1693,7 +1706,8 @@ isert_cq_drain_comp_llist(struct isert_conn *isert_conn, struct ib_device *ib_de
wr = &t->isert_cmd->rdma_wr;
atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
- isert_completion_put(t, t->isert_cmd, ib_dev);
+
+ isert_completion_put(t, t->isert_cmd, ib_dev, true);
}
}
@@ -1712,14 +1726,15 @@ isert_cq_tx_comp_err(struct iser_tx_desc *tx_desc, struct isert_conn *isert_conn
wr = &t->isert_cmd->rdma_wr;
atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
- isert_completion_put(t, t->isert_cmd, ib_dev);
+
+ isert_completion_put(t, t->isert_cmd, ib_dev, true);
}
tx_desc->comp_llnode_batch = NULL;
if (!isert_cmd)
isert_unmap_tx_desc(tx_desc, ib_dev);
else
- isert_completion_put(tx_desc, isert_cmd, ib_dev);
+ isert_completion_put(tx_desc, isert_cmd, ib_dev, true);
}
static void
--
1.9.1
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