Introduce a state enum into sdebug_defer objects to indicate which, if any, defer method has been used with the associated command. Also add 2 bools to indicate which of the defer methods has been initialized. Those objects are re-used but the initialization only needs to be done once. This simplifies command cancellation handling.
Now the delay associated with a deferred response of a command cannot be changed (once started) by changing the delay (and ndelay) parameters in sysfs. Command aborts and driver shutdown are still honoured immediately when received. Signed-off-by: Douglas Gilbert <[email protected]> --- drivers/scsi/scsi_debug.c | 72 ++++++++++++++++++++++++++++++----------------- 1 file changed, 46 insertions(+), 26 deletions(-) diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c index e4f037f0f38b..f5d0098b5a6a 100644 --- a/drivers/scsi/scsi_debug.c +++ b/drivers/scsi/scsi_debug.c @@ -263,12 +263,18 @@ struct sdebug_host_info { #define to_sdebug_host(d) \ container_of(d, struct sdebug_host_info, dev) +enum sdeb_defer_type {SDEB_DEFER_NONE = 0, SDEB_DEFER_HRT = 1, + SDEB_DEFER_WQ = 2}; + struct sdebug_defer { struct hrtimer hrt; struct execute_work ew; int sqa_idx; /* index of sdebug_queue array */ int qc_idx; /* index of sdebug_queued_cmd array within sqa_idx */ int issuing_cpu; + bool init_hrt; + bool init_wq; + enum sdeb_defer_type defer_t; }; struct sdebug_queued_cmd { @@ -3495,6 +3501,7 @@ static void sdebug_q_cmd_complete(struct sdebug_defer *sd_dp) struct scsi_cmnd *scp; struct sdebug_dev_info *devip; + sd_dp->defer_t = SDEB_DEFER_NONE; qc_idx = sd_dp->qc_idx; sqp = sdebug_q_arr + sd_dp->sqa_idx; if (sdebug_statistics) { @@ -3678,13 +3685,14 @@ static void scsi_debug_slave_destroy(struct scsi_device *sdp) } } -static void stop_qc_helper(struct sdebug_defer *sd_dp) +static void stop_qc_helper(struct sdebug_defer *sd_dp, + enum sdeb_defer_type defer_t) { if (!sd_dp) return; - if ((sdebug_jdelay > 0) || (sdebug_ndelay > 0)) + if (defer_t == SDEB_DEFER_HRT) hrtimer_cancel(&sd_dp->hrt); - else if (sdebug_jdelay < 0) + else if (defer_t == SDEB_DEFER_WQ) cancel_work_sync(&sd_dp->ew.work); } @@ -3694,6 +3702,7 @@ static bool stop_queued_cmnd(struct scsi_cmnd *cmnd) { unsigned long iflags; int j, k, qmax, r_qmax; + enum sdeb_defer_type l_defer_t; struct sdebug_queue *sqp; struct sdebug_queued_cmd *sqcp; struct sdebug_dev_info *devip; @@ -3717,8 +3726,13 @@ static bool stop_queued_cmnd(struct scsi_cmnd *cmnd) atomic_dec(&devip->num_in_q); sqcp->a_cmnd = NULL; sd_dp = sqcp->sd_dp; + if (sd_dp) { + l_defer_t = sd_dp->defer_t; + sd_dp->defer_t = SDEB_DEFER_NONE; + } else + l_defer_t = SDEB_DEFER_NONE; spin_unlock_irqrestore(&sqp->qc_lock, iflags); - stop_qc_helper(sd_dp); + stop_qc_helper(sd_dp, l_defer_t); clear_bit(k, sqp->in_use_bm); return true; } @@ -3733,6 +3747,7 @@ static void stop_all_queued(void) { unsigned long iflags; int j, k; + enum sdeb_defer_type l_defer_t; struct sdebug_queue *sqp; struct sdebug_queued_cmd *sqcp; struct sdebug_dev_info *devip; @@ -3751,8 +3766,13 @@ static void stop_all_queued(void) atomic_dec(&devip->num_in_q); sqcp->a_cmnd = NULL; sd_dp = sqcp->sd_dp; + if (sd_dp) { + l_defer_t = sd_dp->defer_t; + sd_dp->defer_t = SDEB_DEFER_NONE; + } else + l_defer_t = SDEB_DEFER_NONE; spin_unlock_irqrestore(&sqp->qc_lock, iflags); - stop_qc_helper(sd_dp); + stop_qc_helper(sd_dp, l_defer_t); clear_bit(k, sqp->in_use_bm); spin_lock_irqsave(&sqp->qc_lock, iflags); } @@ -4003,7 +4023,7 @@ static void setup_inject(struct sdebug_queue *sqp, * SCSI_MLQUEUE_HOST_BUSY if temporarily out of resources. */ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, - int scsi_result, int delta_jiff) + int scsi_result, int delta_jiff, int ndelay) { unsigned long iflags; int k, num_in_q, qdepth, inject; @@ -4081,7 +4101,12 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, spin_unlock_irqrestore(&sqp->qc_lock, iflags); if (unlikely(sdebug_every_nth && sdebug_any_injecting_opt)) setup_inject(sqp, sqcp); - if (delta_jiff > 0 || sdebug_ndelay > 0) { + if (sd_dp == NULL) { + sd_dp = kzalloc(sizeof(*sd_dp), GFP_ATOMIC); + if (sd_dp == NULL) + return SCSI_MLQUEUE_HOST_BUSY; + } + if (delta_jiff > 0 || ndelay > 0) { ktime_t kt; if (delta_jiff > 0) { @@ -4090,11 +4115,9 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, jiffies_to_timespec(delta_jiff, &ts); kt = ktime_set(ts.tv_sec, ts.tv_nsec); } else - kt = sdebug_ndelay; - if (NULL == sd_dp) { - sd_dp = kzalloc(sizeof(*sd_dp), GFP_ATOMIC); - if (NULL == sd_dp) - return SCSI_MLQUEUE_HOST_BUSY; + kt = ndelay; + if (!sd_dp->init_hrt) { + sd_dp->init_hrt = true; sqcp->sd_dp = sd_dp; hrtimer_init(&sd_dp->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED); @@ -4104,12 +4127,11 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, } if (sdebug_statistics) sd_dp->issuing_cpu = raw_smp_processor_id(); + sd_dp->defer_t = SDEB_DEFER_HRT; hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL_PINNED); } else { /* jdelay < 0, use work queue */ - if (NULL == sd_dp) { - sd_dp = kzalloc(sizeof(*sqcp->sd_dp), GFP_ATOMIC); - if (NULL == sd_dp) - return SCSI_MLQUEUE_HOST_BUSY; + if (!sd_dp->init_wq) { + sd_dp->init_wq = true; sqcp->sd_dp = sd_dp; sd_dp->sqa_idx = sqp - sdebug_q_arr; sd_dp->qc_idx = k; @@ -4117,6 +4139,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip, } if (sdebug_statistics) sd_dp->issuing_cpu = raw_smp_processor_id(); + sd_dp->defer_t = SDEB_DEFER_WQ; schedule_work(&sd_dp->ew.work); } if (unlikely((SDEBUG_OPT_Q_NOISE & sdebug_opts) && @@ -4360,9 +4383,6 @@ static ssize_t delay_store(struct device_driver *ddp, const char *buf, } } if (res > 0) { - /* make sure sdebug_defer instances get - * re-allocated for new delay variant */ - free_all_queued(); sdebug_jdelay = jdelay; sdebug_ndelay = 0; } @@ -4403,9 +4423,6 @@ static ssize_t ndelay_store(struct device_driver *ddp, const char *buf, } } if (res > 0) { - /* make sure sdebug_defer instances get - * re-allocated for new delay variant */ - free_all_queued(); sdebug_ndelay = ndelay; sdebug_jdelay = ndelay ? JDELAY_OVERRIDDEN : DEF_JDELAY; @@ -5420,12 +5437,15 @@ static int scsi_debug_queuecommand(struct Scsi_Host *shost, errsts = r_pfp(scp, devip); fini: - return schedule_resp(scp, devip, errsts, - ((F_DELAY_OVERR & flags) ? 0 : sdebug_jdelay)); + if (F_DELAY_OVERR & flags) + return schedule_resp(scp, devip, errsts, 0, 0); + else + return schedule_resp(scp, devip, errsts, sdebug_jdelay, + sdebug_ndelay); check_cond: - return schedule_resp(scp, devip, check_condition_result, 0); + return schedule_resp(scp, devip, check_condition_result, 0, 0); err_out: - return schedule_resp(scp, NULL, DID_NO_CONNECT << 16, 0); + return schedule_resp(scp, NULL, DID_NO_CONNECT << 16, 0, 0); } static struct scsi_host_template sdebug_driver_template = { -- 2.14.1
