diff options
author | Mike Christie <mchristi@redhat.com> | 2017-11-28 19:40:40 +0100 |
---|---|---|
committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2018-01-13 00:07:19 +0100 |
commit | 9103575ae34e9d60d40940bebf47fc9e9652067a (patch) | |
tree | c4b6876c6ec96498a9ab435e8091a07ed49a617b /drivers/target | |
parent | tcmu: don't block submitting context for block waits (diff) | |
download | linux-9103575ae34e9d60d40940bebf47fc9e9652067a.tar.xz linux-9103575ae34e9d60d40940bebf47fc9e9652067a.zip |
tcmu: make ring buffer timer configurable
This adds a timer, qfull_time_out, that controls how long a
device will wait for ring buffer space to open before
failing the commands in the queue. It is useful to separate
this timer from the cmd_time_out and default 30 sec one,
because for HA setups cmd_time_out may be disbled and 30
seconds is too long to wait when some OSs like ESX will
timeout commands after as little as 8 - 15 seconds.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target')
-rw-r--r-- | drivers/target/target_core_user.c | 149 |
1 files changed, 115 insertions, 34 deletions
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 52fc1d440d23..c6a0c3198ccc 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -142,8 +142,12 @@ struct tcmu_dev { struct idr commands; - struct timer_list timeout; + struct timer_list cmd_timer; unsigned int cmd_time_out; + + struct timer_list qfull_timer; + int qfull_time_out; + struct list_head timedout_entry; spinlock_t nl_cmd_lock; @@ -741,18 +745,14 @@ static inline size_t tcmu_cmd_get_cmd_size(struct tcmu_cmd *tcmu_cmd, return command_size; } -static int tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd) +static int tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd, unsigned int tmo, + struct timer_list *timer) { struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; - unsigned long tmo = udev->cmd_time_out; int cmd_id; - /* - * If it was on the cmdr queue waiting we do not reset the timer - * for requeues and when it is finally sent to userspace. - */ if (tcmu_cmd->cmd_id) - return 0; + goto setup_timer; cmd_id = idr_alloc(&udev->commands, tcmu_cmd, 1, USHRT_MAX, GFP_NOWAIT); if (cmd_id < 0) { @@ -761,23 +761,38 @@ static int tcmu_setup_cmd_timer(struct tcmu_cmd *tcmu_cmd) } tcmu_cmd->cmd_id = cmd_id; - if (!tmo) - tmo = TCMU_TIME_OUT; - pr_debug("allocated cmd %u for dev %s tmo %lu\n", tcmu_cmd->cmd_id, udev->name, tmo / MSEC_PER_SEC); +setup_timer: + if (!tmo) + return 0; + tcmu_cmd->deadline = round_jiffies_up(jiffies + msecs_to_jiffies(tmo)); - mod_timer(&udev->timeout, tcmu_cmd->deadline); + mod_timer(timer, tcmu_cmd->deadline); return 0; } static int add_to_cmdr_queue(struct tcmu_cmd *tcmu_cmd) { struct tcmu_dev *udev = tcmu_cmd->tcmu_dev; + unsigned int tmo; int ret; - ret = tcmu_setup_cmd_timer(tcmu_cmd); + /* + * For backwards compat if qfull_time_out is not set use + * cmd_time_out and if that's not set use the default time out. + */ + if (!udev->qfull_time_out) + return -ETIMEDOUT; + else if (udev->qfull_time_out > 0) + tmo = udev->qfull_time_out; + else if (udev->cmd_time_out) + tmo = udev->cmd_time_out; + else + tmo = TCMU_TIME_OUT; + + ret = tcmu_setup_cmd_timer(tcmu_cmd, tmo, &udev->qfull_timer); if (ret) return ret; @@ -901,7 +916,8 @@ static sense_reason_t queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, int *scsi_err) } entry->req.iov_bidi_cnt = iov_cnt; - ret = tcmu_setup_cmd_timer(tcmu_cmd); + ret = tcmu_setup_cmd_timer(tcmu_cmd, udev->cmd_time_out, + &udev->cmd_timer); if (ret) { tcmu_cmd_free_data(tcmu_cmd, tcmu_cmd->dbi_cnt); mutex_unlock(&udev->cmdr_lock); @@ -1049,14 +1065,19 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev) handled++; } - if (mb->cmd_tail == mb->cmd_head && list_empty(&udev->cmdr_queue)) { - del_timer(&udev->timeout); - /* - * not more pending or waiting commands so try to reclaim - * blocks if needed. - */ - if (atomic_read(&global_db_count) > TCMU_GLOBAL_MAX_BLOCKS) - schedule_delayed_work(&tcmu_unmap_work, 0); + if (mb->cmd_tail == mb->cmd_head) { + /* no more pending commands */ + del_timer(&udev->cmd_timer); + + if (list_empty(&udev->cmdr_queue)) { + /* + * no more pending or waiting commands so try to + * reclaim blocks if needed. + */ + if (atomic_read(&global_db_count) > + TCMU_GLOBAL_MAX_BLOCKS) + schedule_delayed_work(&tcmu_unmap_work, 0); + } } return handled; @@ -1077,13 +1098,15 @@ static int tcmu_check_expired_cmd(int id, void *p, void *data) return 0; is_running = list_empty(&cmd->cmdr_queue_entry); - pr_debug("Timing out cmd %u on dev %s that is %s.\n", - id, udev->name, is_running ? "inflight" : "queued"); - - se_cmd = cmd->se_cmd; - cmd->se_cmd = NULL; if (is_running) { + /* + * If cmd_time_out is disabled but qfull is set deadline + * will only reflect the qfull timeout. Ignore it. + */ + if (!udev->cmd_time_out) + return 0; + set_bit(TCMU_CMD_BIT_EXPIRED, &cmd->flags); /* * target_complete_cmd will translate this to LUN COMM FAILURE @@ -1096,16 +1119,18 @@ static int tcmu_check_expired_cmd(int id, void *p, void *data) tcmu_free_cmd(cmd); scsi_status = SAM_STAT_TASK_SET_FULL; } + + pr_debug("Timing out cmd %u on dev %s that is %s.\n", + id, udev->name, is_running ? "inflight" : "queued"); + + se_cmd = cmd->se_cmd; + cmd->se_cmd = NULL; target_complete_cmd(se_cmd, scsi_status); return 0; } -static void tcmu_device_timedout(struct timer_list *t) +static void tcmu_device_timedout(struct tcmu_dev *udev) { - struct tcmu_dev *udev = from_timer(udev, t, timeout); - - pr_debug("%s cmd timeout has expired\n", udev->name); - spin_lock(&timed_out_udevs_lock); if (list_empty(&udev->timedout_entry)) list_add_tail(&udev->timedout_entry, &timed_out_udevs); @@ -1114,6 +1139,22 @@ static void tcmu_device_timedout(struct timer_list *t) schedule_delayed_work(&tcmu_unmap_work, 0); } +static void tcmu_cmd_timedout(struct timer_list *t) +{ + struct tcmu_dev *udev = from_timer(udev, t, cmd_timer); + + pr_debug("%s cmd timeout has expired\n", udev->name); + tcmu_device_timedout(udev); +} + +static void tcmu_qfull_timedout(struct timer_list *t) +{ + struct tcmu_dev *udev = from_timer(udev, t, qfull_timer); + + pr_debug("%s qfull timeout has expired\n", udev->name); + tcmu_device_timedout(udev); +} + static int tcmu_attach_hba(struct se_hba *hba, u32 host_id) { struct tcmu_hba *tcmu_hba; @@ -1151,6 +1192,7 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) udev->hba = hba; udev->cmd_time_out = TCMU_TIME_OUT; + udev->qfull_time_out = -1; mutex_init(&udev->cmdr_lock); @@ -1158,7 +1200,8 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name) INIT_LIST_HEAD(&udev->cmdr_queue); idr_init(&udev->commands); - timer_setup(&udev->timeout, tcmu_device_timedout, 0); + timer_setup(&udev->qfull_timer, tcmu_qfull_timedout, 0); + timer_setup(&udev->cmd_timer, tcmu_cmd_timedout, 0); init_waitqueue_head(&udev->nl_cmd_wq); spin_lock_init(&udev->nl_cmd_lock); @@ -1213,6 +1256,8 @@ static bool run_cmdr_queue(struct tcmu_dev *udev) goto done; } } + if (list_empty(&udev->cmdr_queue)) + del_timer(&udev->qfull_timer); done: return drained; } @@ -1712,7 +1757,8 @@ static void tcmu_destroy_device(struct se_device *dev) { struct tcmu_dev *udev = TCMU_DEV(dev); - del_timer_sync(&udev->timeout); + del_timer_sync(&udev->cmd_timer); + del_timer_sync(&udev->qfull_timer); mutex_lock(&root_udev_mutex); list_del(&udev->node); @@ -1893,6 +1939,40 @@ static ssize_t tcmu_cmd_time_out_store(struct config_item *item, const char *pag } CONFIGFS_ATTR(tcmu_, cmd_time_out); +static ssize_t tcmu_qfull_time_out_show(struct config_item *item, char *page) +{ + struct se_dev_attrib *da = container_of(to_config_group(item), + struct se_dev_attrib, da_group); + struct tcmu_dev *udev = TCMU_DEV(da->da_dev); + + return snprintf(page, PAGE_SIZE, "%ld\n", udev->qfull_time_out <= 0 ? + udev->qfull_time_out : + udev->qfull_time_out / MSEC_PER_SEC); +} + +static ssize_t tcmu_qfull_time_out_store(struct config_item *item, + const char *page, size_t count) +{ + struct se_dev_attrib *da = container_of(to_config_group(item), + struct se_dev_attrib, da_group); + struct tcmu_dev *udev = TCMU_DEV(da->da_dev); + s32 val; + int ret; + + ret = kstrtos32(page, 0, &val); + if (ret < 0) + return ret; + + if (val >= 0) { + udev->qfull_time_out = val * MSEC_PER_SEC; + } else { + printk(KERN_ERR "Invalid qfull timeout value %d\n", val); + return -EINVAL; + } + return count; +} +CONFIGFS_ATTR(tcmu_, qfull_time_out); + static ssize_t tcmu_dev_config_show(struct config_item *item, char *page) { struct se_dev_attrib *da = container_of(to_config_group(item), @@ -2038,6 +2118,7 @@ CONFIGFS_ATTR(tcmu_, emulate_write_cache); static struct configfs_attribute *tcmu_attrib_attrs[] = { &tcmu_attr_cmd_time_out, + &tcmu_attr_qfull_time_out, &tcmu_attr_dev_config, &tcmu_attr_dev_size, &tcmu_attr_emulate_write_cache, |