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authorNicholas Bellinger <nab@linux-iscsi.org>2013-11-13 05:54:56 +0400
committerNicholas Bellinger <nab@linux-iscsi.org>2013-11-13 05:54:56 +0400
commit5e8e6b4b3adebf01a9d97056cbbfd8c44330df99 (patch)
tree26d9d918a3000c6a0f60a72ee0706004969429ad /drivers/target
parent0f59cc3fc1c04413eb1368b57f5e806ebd731ef8 (diff)
downloadlinux-5e8e6b4b3adebf01a9d97056cbbfd8c44330df99.tar.xz
iscsi-target: Fix mutex_trylock usage in iscsit_increment_maxcmdsn
This patch fixes a >= v3.10 regression bug with mutex_trylock() usage within iscsit_increment_maxcmdsn(), that was originally added to allow for a special case where ->cmdsn_mutex was already held from the iscsit_execute_cmd() exception path for ib_isert. When !mutex_trylock() was occuring under contention during normal RX/TX process context codepaths, the bug was manifesting itself as the following protocol error: Received CmdSN: 0x000fcbb7 is greater than MaxCmdSN: 0x000fcbb6, protocol error. Received CmdSN: 0x000fcbb8 is greater than MaxCmdSN: 0x000fcbb6, protocol error. This patch simply avoids the direct ib_isert callback in lio_queue_status() for the special iscsi_execute_cmd() exception cases, that allows the problematic mutex_trylock() usage in iscsit_increment_maxcmdsn() to go away. Reported-by: Moussa Ba <moussaba@micron.com> Tested-by: Moussa Ba <moussaba@micron.com> Cc: <stable@vger.kernel.org> # v3.10+ Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/iscsi/iscsi_target_configfs.c5
-rw-r--r--drivers/target/iscsi/iscsi_target_device.c6
2 files changed, 6 insertions, 5 deletions
diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index 1eec37c47662..fde3624dce7e 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -1790,6 +1790,11 @@ static int lio_queue_status(struct se_cmd *se_cmd)
struct iscsi_cmd *cmd = container_of(se_cmd, struct iscsi_cmd, se_cmd);
cmd->i_state = ISTATE_SEND_STATUS;
+
+ if (cmd->se_cmd.scsi_status || cmd->sense_reason) {
+ iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
+ return 0;
+ }
cmd->conn->conn_transport->iscsit_queue_status(cmd->conn, cmd);
return 0;
diff --git a/drivers/target/iscsi/iscsi_target_device.c b/drivers/target/iscsi/iscsi_target_device.c
index 6c7a5104a4cd..7087c736daa5 100644
--- a/drivers/target/iscsi/iscsi_target_device.c
+++ b/drivers/target/iscsi/iscsi_target_device.c
@@ -58,11 +58,7 @@ void iscsit_increment_maxcmdsn(struct iscsi_cmd *cmd, struct iscsi_session *sess
cmd->maxcmdsn_inc = 1;
- if (!mutex_trylock(&sess->cmdsn_mutex)) {
- sess->max_cmd_sn += 1;
- pr_debug("Updated MaxCmdSN to 0x%08x\n", sess->max_cmd_sn);
- return;
- }
+ mutex_lock(&sess->cmdsn_mutex);
sess->max_cmd_sn += 1;
pr_debug("Updated MaxCmdSN to 0x%08x\n", sess->max_cmd_sn);
mutex_unlock(&sess->cmdsn_mutex);