From aafc9d158b0039e600fc429246c7bb04a111fb26 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Fri, 31 May 2013 00:49:41 -0700 Subject: [PATCH] iscsi-target: Fix iscsit_free_cmd() se_cmd->cmd_kref shutdown handling With the introduction of target_get_sess_cmd() referencing counting for ISCSI_OP_SCSI_CMD processing with iser-target, iscsit_free_cmd() usage in traditional iscsi-target driver code now needs to be aware of the active I/O shutdown case when a remaining se_cmd->cmd_kref reference may exist after transport_generic_free_cmd() completes, requiring a final target_put_sess_cmd() to release iscsi_cmd descriptor memory. This patch changes iscsit_free_cmd() to invoke __iscsit_free_cmd() before transport_generic_free_cmd() -> target_put_sess_cmd(), and also avoids aquiring the per-connection queue locks for typical fast-path calls during normal ISTATE_REMOVE operation. Also update iscsit_free_cmd() usage throughout iscsi-target to use the new 'bool shutdown' parameter. This patch fixes a regression bug introduced during v3.10-rc1 in commit 3e1c81a95, that was causing the following WARNING to appear: [ 257.235153] ------------[ cut here]------------ [ 257.240314] WARNING: at kernel/softirq.c:160 local_bh_enable_ip+0x3c/0x86() [ 257.248089] Modules linked in: vhost_scsi ib_srpt ib_cm ib_sa ib_mad ib_core tcm_qla2xxx tcm_loop tcm_fc libfc iscsi_target_mod target_core_pscsi target_core_file target_core_iblock target_core_mod configfs ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi loop acpi_cpufreq freq_table mperf kvm_intel kvm crc32c_intel button ehci_pci pcspkr joydev i2c_i801 microcode ext3 jbd raid10 raid456 async_pq async_xor xor async_memcpy async_raid6_recov raid6_pq async_tx raid1 raid0 linear igb hwmon i2c_algo_bit i2c_core ptp ata_piix libata qla2xxx uhci_hcd ehci_hcd mlx4_core scsi_transport_fc scsi_tgt pps_core [ 257.308748] CPU: 1 PID: 3295 Comm: iscsi_ttx Not tainted 3.10.0-rc2+ #103 [ 257.316329] Hardware name: Intel Corporation S5520HC/S5520HC, BIOS S5500.86B.01.00.0057.031020111721 03/10/2011 [ 257.327597] ffffffff814c24b7 ffff880458331b58 ffffffff8138eef2 ffff880458331b98 [ 257.335892] ffffffff8102c052 ffff880400000008 0000000000000000 ffff88085bdf0000 [ 257.344191] ffff88085bdf00d8 ffff88085bdf00e0 ffff88085bdf00f8 ffff880458331ba8 [ 257.352488] Call Trace: [ 257.355223] [] dump_stack+0x19/0x1f [ 257.360963] [] warn_slowpath_common+0x62/0x7b [ 257.367669] [] warn_slowpath_null+0x15/0x17 [ 257.374181] [] local_bh_enable_ip+0x3c/0x86 [ 257.380697] [] _raw_spin_unlock_bh+0x10/0x12 [ 257.387311] [] iscsit_free_r2ts_from_list+0x5e/0x67 [iscsi_target_mod] [ 257.396438] [] iscsit_release_cmd+0x20/0x223 [iscsi_target_mod] [ 257.404893] [] lio_release_cmd+0x3a/0x3e [iscsi_target_mod] [ 257.412964] [] target_release_cmd_kref+0x7a/0x7c [target_core_mod] [ 257.421712] [] target_put_sess_cmd+0x5f/0x7f [target_core_mod] [ 257.430071] [] transport_release_cmd+0x59/0x6f [target_core_mod] [ 257.438625] [] transport_put_cmd+0x131/0x140 [target_core_mod] [ 257.446985] [] ? transport_wait_for_tasks+0xfa/0x1d5 [target_core_mod] [ 257.456121] [] transport_generic_free_cmd+0x4e/0x52 [target_core_mod] [ 257.465159] [] ? __migrate_task+0x110/0x110 [ 257.471674] [] iscsit_free_cmd+0x46/0x55 [iscsi_target_mod] [ 257.479741] [] iscsit_immediate_queue+0x301/0x353 [iscsi_target_mod] [ 257.488683] [] iscsi_target_tx_thread+0x1c6/0x2a8 [iscsi_target_mod] [ 257.497623] [] ? wake_up_bit+0x25/0x25 [ 257.503652] [] ? iscsit_ack_from_expstatsn+0xd5/0xd5 [iscsi_target_mod] [ 257.512882] [] kthread+0xb0/0xb8 [ 257.518329] [] ? kthread_freezable_should_stop+0x60/0x60 [ 257.526105] [] ret_from_fork+0x7c/0xb0 [ 257.532133] [] ? kthread_freezable_should_stop+0x60/0x60 [ 257.539906] ---[ end trace 5520397d0f2e0800 ]--- Signed-off-by: Nicholas Bellinger --- drivers/target/iscsi/iscsi_target.c | 12 +++--- drivers/target/iscsi/iscsi_target_erl2.c | 12 +++--- drivers/target/iscsi/iscsi_target_util.c | 50 ++++++++++++++++++------ drivers/target/iscsi/iscsi_target_util.h | 2 +- 4 files changed, 50 insertions(+), 26 deletions(-) diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c index 262ef1f23b38..d7705e5824fb 100644 --- a/drivers/target/iscsi/iscsi_target.c +++ b/drivers/target/iscsi/iscsi_target.c @@ -651,7 +651,7 @@ static int iscsit_add_reject( cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL); if (!cmd->buf_ptr) { pr_err("Unable to allocate memory for cmd->buf_ptr\n"); - iscsit_release_cmd(cmd); + iscsit_free_cmd(cmd, false); return -1; } @@ -697,7 +697,7 @@ int iscsit_add_reject_from_cmd( cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL); if (!cmd->buf_ptr) { pr_err("Unable to allocate memory for cmd->buf_ptr\n"); - iscsit_release_cmd(cmd); + iscsit_free_cmd(cmd, false); return -1; } @@ -1743,7 +1743,7 @@ int iscsit_handle_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd, return 0; out: if (cmd) - iscsit_release_cmd(cmd); + iscsit_free_cmd(cmd, false); ping_out: kfree(ping_data); return ret; @@ -2251,7 +2251,7 @@ iscsit_handle_logout_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd, if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) { pr_err("Received logout request on connection that" " is not in logged in state, ignoring request.\n"); - iscsit_release_cmd(cmd); + iscsit_free_cmd(cmd, false); return 0; } @@ -3665,7 +3665,7 @@ iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state list_del(&cmd->i_conn_node); spin_unlock_bh(&conn->cmd_lock); - iscsit_free_cmd(cmd); + iscsit_free_cmd(cmd, false); break; case ISTATE_SEND_NOPIN_WANT_RESPONSE: iscsit_mod_nopin_response_timer(conn); @@ -4122,7 +4122,7 @@ static void iscsit_release_commands_from_conn(struct iscsi_conn *conn) iscsit_increment_maxcmdsn(cmd, sess); - iscsit_free_cmd(cmd); + iscsit_free_cmd(cmd, true); spin_lock_bh(&conn->cmd_lock); } diff --git a/drivers/target/iscsi/iscsi_target_erl2.c b/drivers/target/iscsi/iscsi_target_erl2.c index ba6091bf93fc..45a5afd5ea13 100644 --- a/drivers/target/iscsi/iscsi_target_erl2.c +++ b/drivers/target/iscsi/iscsi_target_erl2.c @@ -143,7 +143,7 @@ void iscsit_free_connection_recovery_entires(struct iscsi_session *sess) list_del(&cmd->i_conn_node); cmd->conn = NULL; spin_unlock(&cr->conn_recovery_cmd_lock); - iscsit_free_cmd(cmd); + iscsit_free_cmd(cmd, true); spin_lock(&cr->conn_recovery_cmd_lock); } spin_unlock(&cr->conn_recovery_cmd_lock); @@ -165,7 +165,7 @@ void iscsit_free_connection_recovery_entires(struct iscsi_session *sess) list_del(&cmd->i_conn_node); cmd->conn = NULL; spin_unlock(&cr->conn_recovery_cmd_lock); - iscsit_free_cmd(cmd); + iscsit_free_cmd(cmd, true); spin_lock(&cr->conn_recovery_cmd_lock); } spin_unlock(&cr->conn_recovery_cmd_lock); @@ -248,7 +248,7 @@ void iscsit_discard_cr_cmds_by_expstatsn( iscsit_remove_cmd_from_connection_recovery(cmd, sess); spin_unlock(&cr->conn_recovery_cmd_lock); - iscsit_free_cmd(cmd); + iscsit_free_cmd(cmd, true); spin_lock(&cr->conn_recovery_cmd_lock); } spin_unlock(&cr->conn_recovery_cmd_lock); @@ -302,7 +302,7 @@ int iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(struct iscsi_conn *conn) list_del(&cmd->i_conn_node); spin_unlock_bh(&conn->cmd_lock); - iscsit_free_cmd(cmd); + iscsit_free_cmd(cmd, true); spin_lock_bh(&conn->cmd_lock); } spin_unlock_bh(&conn->cmd_lock); @@ -355,7 +355,7 @@ int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn) list_del(&cmd->i_conn_node); spin_unlock_bh(&conn->cmd_lock); - iscsit_free_cmd(cmd); + iscsit_free_cmd(cmd, true); spin_lock_bh(&conn->cmd_lock); continue; } @@ -375,7 +375,7 @@ int iscsit_prepare_cmds_for_realligance(struct iscsi_conn *conn) iscsi_sna_gte(cmd->cmd_sn, conn->sess->exp_cmd_sn)) { list_del(&cmd->i_conn_node); spin_unlock_bh(&conn->cmd_lock); - iscsit_free_cmd(cmd); + iscsit_free_cmd(cmd, true); spin_lock_bh(&conn->cmd_lock); continue; } diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c index 2cc6c9a3ffb8..08a3bacef0c5 100644 --- a/drivers/target/iscsi/iscsi_target_util.c +++ b/drivers/target/iscsi/iscsi_target_util.c @@ -676,40 +676,56 @@ void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn) void iscsit_release_cmd(struct iscsi_cmd *cmd) { - struct iscsi_conn *conn = cmd->conn; - - iscsit_free_r2ts_from_list(cmd); - iscsit_free_all_datain_reqs(cmd); - kfree(cmd->buf_ptr); kfree(cmd->pdu_list); kfree(cmd->seq_list); kfree(cmd->tmr_req); kfree(cmd->iov_data); - if (conn) { + kmem_cache_free(lio_cmd_cache, cmd); +} + +static void __iscsit_free_cmd(struct iscsi_cmd *cmd, bool scsi_cmd, + bool check_queues) +{ + struct iscsi_conn *conn = cmd->conn; + + if (scsi_cmd) { + if (cmd->data_direction == DMA_TO_DEVICE) { + iscsit_stop_dataout_timer(cmd); + iscsit_free_r2ts_from_list(cmd); + } + if (cmd->data_direction == DMA_FROM_DEVICE) + iscsit_free_all_datain_reqs(cmd); + } + + if (conn && check_queues) { iscsit_remove_cmd_from_immediate_queue(cmd, conn); iscsit_remove_cmd_from_response_queue(cmd, conn); } - - kmem_cache_free(lio_cmd_cache, cmd); } -void iscsit_free_cmd(struct iscsi_cmd *cmd) +void iscsit_free_cmd(struct iscsi_cmd *cmd, bool shutdown) { + struct se_cmd *se_cmd = NULL; + int rc; /* * Determine if a struct se_cmd is associated with * this struct iscsi_cmd. */ switch (cmd->iscsi_opcode) { case ISCSI_OP_SCSI_CMD: - if (cmd->data_direction == DMA_TO_DEVICE) - iscsit_stop_dataout_timer(cmd); + se_cmd = &cmd->se_cmd; + __iscsit_free_cmd(cmd, true, shutdown); /* * Fallthrough */ case ISCSI_OP_SCSI_TMFUNC: - transport_generic_free_cmd(&cmd->se_cmd, 1); + rc = transport_generic_free_cmd(&cmd->se_cmd, 1); + if (!rc && shutdown && se_cmd && se_cmd->se_sess) { + __iscsit_free_cmd(cmd, true, shutdown); + target_put_sess_cmd(se_cmd->se_sess, se_cmd); + } break; case ISCSI_OP_REJECT: /* @@ -718,11 +734,19 @@ void iscsit_free_cmd(struct iscsi_cmd *cmd) * associated cmd->se_cmd needs to be released. */ if (cmd->se_cmd.se_tfo != NULL) { - transport_generic_free_cmd(&cmd->se_cmd, 1); + se_cmd = &cmd->se_cmd; + __iscsit_free_cmd(cmd, true, shutdown); + + rc = transport_generic_free_cmd(&cmd->se_cmd, 1); + if (!rc && shutdown && se_cmd->se_sess) { + __iscsit_free_cmd(cmd, true, shutdown); + target_put_sess_cmd(se_cmd->se_sess, se_cmd); + } break; } /* Fall-through */ default: + __iscsit_free_cmd(cmd, false, shutdown); cmd->release_cmd(cmd); break; } diff --git a/drivers/target/iscsi/iscsi_target_util.h b/drivers/target/iscsi/iscsi_target_util.h index 4f8e01a47081..a4422659d049 100644 --- a/drivers/target/iscsi/iscsi_target_util.h +++ b/drivers/target/iscsi/iscsi_target_util.h @@ -29,7 +29,7 @@ extern void iscsit_remove_cmd_from_tx_queues(struct iscsi_cmd *, struct iscsi_co extern bool iscsit_conn_all_queues_empty(struct iscsi_conn *); extern void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *); extern void iscsit_release_cmd(struct iscsi_cmd *); -extern void iscsit_free_cmd(struct iscsi_cmd *); +extern void iscsit_free_cmd(struct iscsi_cmd *, bool); extern int iscsit_check_session_usage_count(struct iscsi_session *); extern void iscsit_dec_session_usage_count(struct iscsi_session *); extern void iscsit_inc_session_usage_count(struct iscsi_session *); -- 2.20.1