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authorMike Christie <mchristi@redhat.com>2017-11-28 12:40:31 -0600
committerNicholas Bellinger <nab@linux-iscsi.org>2018-01-12 15:07:13 -0800
commit488ebe4c355fdead39dbb3f6a51329c16cbfcc60 (patch)
treeb23d76cc19a8e4fd937ecf94ed517a8571cd17bc /drivers/target/target_core_user.c
parent9972cebb59a653cca735178a70c8ab09a5f4de1a (diff)
tcmu: move expired command completion to unmap thread
This moves the expired command completion handling to the unmap wq, so the next patch can use a mutex in tcmu_check_expired_cmd. Note: tcmu_device_timedout's use of spin_lock_irq was not needed. The commands_lock is used between thread context (tcmu_queue_cmd_ring and tcmu_irqcontrol (even though this is named irqcontrol it is not run in irq context)) and timer/bh context. In the timer/bh context bhs are disabled, so you need to use the _bh lock calls from the thread context callers. Signed-off-by: Mike Christie <mchristi@redhat.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/target/target_core_user.c')
-rw-r--r--drivers/target/target_core_user.c48
1 files changed, 39 insertions, 9 deletions
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index a9f5c52e8b1d..2ccc8e61449b 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -143,6 +143,7 @@ struct tcmu_dev {
struct timer_list timeout;
unsigned int cmd_time_out;
+ struct list_head timedout_entry;
spinlock_t nl_cmd_lock;
struct tcmu_nl_cmd curr_nl_cmd;
@@ -179,6 +180,9 @@ struct tcmu_cmd {
static DEFINE_MUTEX(root_udev_mutex);
static LIST_HEAD(root_udev);
+static DEFINE_SPINLOCK(timed_out_udevs_lock);
+static LIST_HEAD(timed_out_udevs);
+
static atomic_t global_db_count = ATOMIC_INIT(0);
static struct work_struct tcmu_unmap_work;
@@ -1057,18 +1061,15 @@ static int tcmu_check_expired_cmd(int id, void *p, void *data)
static void tcmu_device_timedout(struct timer_list *t)
{
struct tcmu_dev *udev = from_timer(udev, t, timeout);
- unsigned long flags;
- spin_lock_irqsave(&udev->commands_lock, flags);
- idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
- spin_unlock_irqrestore(&udev->commands_lock, flags);
+ pr_debug("%s cmd timeout has expired\n", udev->name);
- schedule_work(&tcmu_unmap_work);
+ spin_lock(&timed_out_udevs_lock);
+ if (list_empty(&udev->timedout_entry))
+ list_add_tail(&udev->timedout_entry, &timed_out_udevs);
+ spin_unlock(&timed_out_udevs_lock);
- /*
- * We don't need to wakeup threads on wait_cmdr since they have their
- * own timeout.
- */
+ schedule_work(&tcmu_unmap_work);
}
static int tcmu_attach_hba(struct se_hba *hba, u32 host_id)
@@ -1112,6 +1113,7 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
init_waitqueue_head(&udev->wait_cmdr);
mutex_init(&udev->cmdr_lock);
+ INIT_LIST_HEAD(&udev->timedout_entry);
idr_init(&udev->commands);
spin_lock_init(&udev->commands_lock);
@@ -1325,6 +1327,11 @@ static void tcmu_dev_kref_release(struct kref *kref)
vfree(udev->mb_addr);
udev->mb_addr = NULL;
+ spin_lock_bh(&timed_out_udevs_lock);
+ if (!list_empty(&udev->timedout_entry))
+ list_del(&udev->timedout_entry);
+ spin_unlock_bh(&timed_out_udevs_lock);
+
/* Upper layer should drain all requests before calling this */
spin_lock_irq(&udev->commands_lock);
idr_for_each_entry(&udev->commands, cmd, i) {
@@ -2041,8 +2048,31 @@ static void run_cmdr_queues(void)
mutex_unlock(&root_udev_mutex);
}
+static void check_timedout_devices(void)
+{
+ struct tcmu_dev *udev, *tmp_dev;
+ LIST_HEAD(devs);
+
+ spin_lock_bh(&timed_out_udevs_lock);
+ list_splice_init(&timed_out_udevs, &devs);
+
+ list_for_each_entry_safe(udev, tmp_dev, &devs, timedout_entry) {
+ list_del_init(&udev->timedout_entry);
+ spin_unlock_bh(&timed_out_udevs_lock);
+
+ spin_lock(&udev->commands_lock);
+ idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
+ spin_unlock(&udev->commands_lock);
+
+ spin_lock_bh(&timed_out_udevs_lock);
+ }
+
+ spin_unlock_bh(&timed_out_udevs_lock);
+}
+
static void tcmu_unmap_work_fn(struct work_struct *work)
{
+ check_timedout_devices();
find_free_blocks();
run_cmdr_queues();
}

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