From 4d3895d5ea43cf40fd707692263c6f0988fe8d70 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 23 May 2017 16:48:39 -0700 Subject: target/tcm_loop: Merge struct tcm_loop_cmd and struct tcm_loop_tmr This patch simplifies the tcm_loop implementation but does not change any functionality. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: David Disseldorp Signed-off-by: Nicholas Bellinger --- drivers/target/loopback/tcm_loop.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) (limited to 'drivers/target/loopback/tcm_loop.c') diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c index 5091b31b3e56..79776b447b15 100644 --- a/drivers/target/loopback/tcm_loop.c +++ b/drivers/target/loopback/tcm_loop.c @@ -221,7 +221,6 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, struct se_portal_group *se_tpg; struct tcm_loop_nexus *tl_nexus; struct tcm_loop_cmd *tl_cmd = NULL; - struct tcm_loop_tmr *tl_tmr = NULL; int ret = TMR_FUNCTION_FAILED, rc; /* @@ -240,12 +239,7 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, return ret; } - tl_tmr = kzalloc(sizeof(struct tcm_loop_tmr), GFP_KERNEL); - if (!tl_tmr) { - pr_err("Unable to allocate memory for tl_tmr\n"); - goto release; - } - init_waitqueue_head(&tl_tmr->tl_tmr_wait); + init_waitqueue_head(&tl_cmd->tl_tmr_wait); se_cmd = &tl_cmd->tl_se_cmd; se_tpg = &tl_tpg->tl_se_tpg; @@ -257,7 +251,7 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, DMA_NONE, TCM_SIMPLE_TAG, &tl_cmd->tl_sense_buf[0]); - rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL); + rc = core_tmr_alloc_req(se_cmd, NULL, tmr, GFP_KERNEL); if (rc < 0) goto release; @@ -276,7 +270,7 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, * tcm_loop_queue_tm_rsp() to wake us up. */ transport_generic_handle_tmr(se_cmd); - wait_event(tl_tmr->tl_tmr_wait, atomic_read(&tl_tmr->tmr_complete)); + wait_event(tl_cmd->tl_tmr_wait, atomic_read(&tl_cmd->tmr_complete)); /* * The TMR LUN_RESET has completed, check the response status and * then release allocations. @@ -287,7 +281,6 @@ release: transport_generic_free_cmd(se_cmd, 1); else kmem_cache_free(tcm_loop_cmd_cache, tl_cmd); - kfree(tl_tmr); return ret; } @@ -669,14 +662,15 @@ static int tcm_loop_queue_status(struct se_cmd *se_cmd) static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd) { - struct se_tmr_req *se_tmr = se_cmd->se_tmr_req; - struct tcm_loop_tmr *tl_tmr = se_tmr->fabric_tmr_ptr; + struct tcm_loop_cmd *tl_cmd = container_of(se_cmd, + struct tcm_loop_cmd, tl_se_cmd); + /* * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead * and wake up the wait_queue_head_t in tcm_loop_device_reset() */ - atomic_set(&tl_tmr->tmr_complete, 1); - wake_up(&tl_tmr->tl_tmr_wait); + atomic_set(&tl_cmd->tmr_complete, 1); + wake_up(&tl_cmd->tl_tmr_wait); } static void tcm_loop_aborted_task(struct se_cmd *se_cmd) -- cgit v1.2.3 From d17203c41185a05ecd4d1fc647f16b17ab1b27ae Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 23 May 2017 16:48:40 -0700 Subject: target/tcm_loop: Replace a waitqueue and a counter by a completion This patch simplifies the implementation of the tcm_loop driver but does not change its behavior. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: David Disseldorp Signed-off-by: Nicholas Bellinger --- drivers/target/loopback/tcm_loop.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'drivers/target/loopback/tcm_loop.c') diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c index 79776b447b15..27f912747113 100644 --- a/drivers/target/loopback/tcm_loop.c +++ b/drivers/target/loopback/tcm_loop.c @@ -239,7 +239,7 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, return ret; } - init_waitqueue_head(&tl_cmd->tl_tmr_wait); + init_completion(&tl_cmd->tmr_done); se_cmd = &tl_cmd->tl_se_cmd; se_tpg = &tl_tpg->tl_se_tpg; @@ -270,7 +270,7 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, * tcm_loop_queue_tm_rsp() to wake us up. */ transport_generic_handle_tmr(se_cmd); - wait_event(tl_cmd->tl_tmr_wait, atomic_read(&tl_cmd->tmr_complete)); + wait_for_completion(&tl_cmd->tmr_done); /* * The TMR LUN_RESET has completed, check the response status and * then release allocations. @@ -665,12 +665,8 @@ static void tcm_loop_queue_tm_rsp(struct se_cmd *se_cmd) struct tcm_loop_cmd *tl_cmd = container_of(se_cmd, struct tcm_loop_cmd, tl_se_cmd); - /* - * The SCSI EH thread will be sleeping on se_tmr->tl_tmr_wait, go ahead - * and wake up the wait_queue_head_t in tcm_loop_device_reset() - */ - atomic_set(&tl_cmd->tmr_complete, 1); - wake_up(&tl_cmd->tl_tmr_wait); + /* Wake up tcm_loop_issue_tmr(). */ + complete(&tl_cmd->tmr_done); } static void tcm_loop_aborted_task(struct se_cmd *se_cmd) -- cgit v1.2.3 From 75f141aaf48e13812b4fee914a66f6fce28b543f Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 23 May 2017 16:48:41 -0700 Subject: target/tcm_loop: Use target_submit_tmr() instead of open-coding this function Use target_submit_tmr() instead of open-coding this function. The only functional change is that TMFs are now added to sess_cmd_list, something the current code does not do. This behavior change is a bug fix because it makes LUN RESETs wait for other TMFs that are in progress for the same LUN. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: David Disseldorp Signed-off-by: Nicholas Bellinger --- drivers/target/loopback/tcm_loop.c | 32 +++----------------------------- 1 file changed, 3 insertions(+), 29 deletions(-) (limited to 'drivers/target/loopback/tcm_loop.c') diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c index 27f912747113..8cf556b4c5ca 100644 --- a/drivers/target/loopback/tcm_loop.c +++ b/drivers/target/loopback/tcm_loop.c @@ -218,7 +218,6 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, { struct se_cmd *se_cmd = NULL; struct se_session *se_sess; - struct se_portal_group *se_tpg; struct tcm_loop_nexus *tl_nexus; struct tcm_loop_cmd *tl_cmd = NULL; int ret = TMR_FUNCTION_FAILED, rc; @@ -242,40 +241,15 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, init_completion(&tl_cmd->tmr_done); se_cmd = &tl_cmd->tl_se_cmd; - se_tpg = &tl_tpg->tl_se_tpg; se_sess = tl_tpg->tl_nexus->se_sess; - /* - * Initialize struct se_cmd descriptor from target_core_mod infrastructure - */ - transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0, - DMA_NONE, TCM_SIMPLE_TAG, - &tl_cmd->tl_sense_buf[0]); - rc = core_tmr_alloc_req(se_cmd, NULL, tmr, GFP_KERNEL); + rc = target_submit_tmr(se_cmd, se_sess, tl_cmd->tl_sense_buf, lun, + NULL, tmr, GFP_KERNEL, task, 0 /*flags*/); if (rc < 0) goto release; - - if (tmr == TMR_ABORT_TASK) - se_cmd->se_tmr_req->ref_task_tag = task; - - /* - * Locate the underlying TCM struct se_lun - */ - if (transport_lookup_tmr_lun(se_cmd, lun) < 0) { - ret = TMR_LUN_DOES_NOT_EXIST; - goto release; - } - /* - * Queue the TMR to TCM Core and sleep waiting for - * tcm_loop_queue_tm_rsp() to wake us up. - */ - transport_generic_handle_tmr(se_cmd); wait_for_completion(&tl_cmd->tmr_done); - /* - * The TMR LUN_RESET has completed, check the response status and - * then release allocations. - */ ret = se_cmd->se_tmr_req->response; + release: if (se_cmd) transport_generic_free_cmd(se_cmd, 1); -- cgit v1.2.3 From 4c1f0e65397f4e5768b955c32489d5b4b6b92a90 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Tue, 23 May 2017 16:48:42 -0700 Subject: target/tcm_loop: Make TMF processing slightly faster Target drivers must guarantee that struct se_cmd and struct se_tmr_req exist as long as target_tmr_work() is in progress. This is why the tcm_loop driver today passes 1 as second argument to transport_generic_free_cmd() from inside the TMF code. Instead of making the TMF code wait, make the TMF code obtain two references (SCF_ACK_KREF) and drop one reference from inside the .check_stop_free() callback. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: David Disseldorp Signed-off-by: Nicholas Bellinger --- drivers/target/loopback/tcm_loop.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) (limited to 'drivers/target/loopback/tcm_loop.c') diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c index 8cf556b4c5ca..b6a913e38b30 100644 --- a/drivers/target/loopback/tcm_loop.c +++ b/drivers/target/loopback/tcm_loop.c @@ -51,19 +51,7 @@ static int tcm_loop_queue_status(struct se_cmd *se_cmd); */ static int tcm_loop_check_stop_free(struct se_cmd *se_cmd) { - /* - * Do not release struct se_cmd's containing a valid TMR - * pointer. These will be released directly in tcm_loop_device_reset() - * with transport_generic_free_cmd(). - */ - if (se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB) - return 0; - /* - * Release the struct se_cmd, which will make a callback to release - * struct tcm_loop_cmd * in tcm_loop_deallocate_core_cmd() - */ - transport_generic_free_cmd(se_cmd, 0); - return 1; + return transport_generic_free_cmd(se_cmd, 0); } static void tcm_loop_release_cmd(struct se_cmd *se_cmd) @@ -244,18 +232,23 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg, se_sess = tl_tpg->tl_nexus->se_sess; rc = target_submit_tmr(se_cmd, se_sess, tl_cmd->tl_sense_buf, lun, - NULL, tmr, GFP_KERNEL, task, 0 /*flags*/); + NULL, tmr, GFP_KERNEL, task, + TARGET_SCF_ACK_KREF); if (rc < 0) goto release; wait_for_completion(&tl_cmd->tmr_done); ret = se_cmd->se_tmr_req->response; + target_put_sess_cmd(se_cmd); + +out: + return ret; release: if (se_cmd) - transport_generic_free_cmd(se_cmd, 1); + transport_generic_free_cmd(se_cmd, 0); else kmem_cache_free(tcm_loop_cmd_cache, tl_cmd); - return ret; + goto out; } static int tcm_loop_abort_task(struct scsi_cmnd *sc) -- cgit v1.2.3