This patch implements the tmr_notify callback for tcmu.
When the callback is called, tcmu checks the list of aborted
commands it received as parameter:
- aborted commands in the qfull_queue are removed from
the queue and target_complete_command is called
- from the cmd_ids of aborted commands currently uncompleted
in cmd ring it creates a list of aborted cmd_ids.
Finally a TMR notification is written to cmd ring containing
TMR type and cmd_id list. If there is no space in ring, the
TMR notification is queued on a TMR specific queue.
The TMR specific queue 'tmr_queue' can be seen as a extension
of the cmd ring. At the end of each iexecution of
tcmu_complete_commands() we check, whether tmr_queue contains
TMRs and try to move them onto the ring. If tmr_queue is not
empty after that, we don't call run_qfull_queue() because
commands must not overtake TMRs.
Operating that way we guarantee that cmd_ids in TMR notification
received by userspace either match an active, not yet completed
command or are no longer valid due to userspace having complete
some cmd_ids meanwhile.
New commands that were assigned to an aborted cmd_id will always
appear on the cmd ring _after_ the TMR.
Signed-off-by: Bodo Stroesser <bstroesser@xxxxxxxxxxxxxx>
---
drivers/target/target_core_user.c | 226 ++++++++++++++++++++++++++++++++--
include/uapi/linux/target_core_user.h | 25 ++++
2 files changed, 242 insertions(+), 9 deletions(-)
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c
index 6adf4e7cc00b..e864706de977 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -137,6 +137,7 @@ struct tcmu_dev {
struct mutex cmdr_lock;
struct list_head qfull_queue;
+ struct list_head tmr_queue;
uint32_t dbi_max;
uint32_t dbi_thresh;
@@ -183,6 +184,15 @@ struct tcmu_cmd {
#define TCMU_CMD_BIT_EXPIRED 0
unsigned long flags;
};
+
+struct tcmu_tmr {
+ struct list_head queue_entry;
+
+ uint8_t tmr_type;
+ uint32_t tmr_cmd_cnt;
+ int16_t tmr_cmd_ids[0];
+};
+
/*
* To avoid dead lock the mutex lock order should always be:
*
@@ -844,6 +854,9 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd,
return false;
}
+ if (!data_needed)
+ return true;
+
/* try to check and get the data blocks as needed */
space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh);
if ((space * DATA_BLOCK_SIZE) < data_needed) {
@@ -1106,6 +1119,61 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err)
return 1;
}
+/*
+ * queue_tmr_ring - queue tmr info to ring or internally
+ *
+ * @dev: related tcmu_dev
+ * @tmr: tcmu_tmr containing tmr info to queue
+ *
+ * Returns:
+ * 0 success
+ * 1 internally queued to wait for ring memory to free.
+ */
+static int
+queue_tmr_ring(struct tcmu_dev *dev, struct tcmu_tmr *tmr)
+{
+ struct tcmu_tmr_entry *entry;
+ int cmd_size;
+ int id_list_sz;
+ struct tcmu_mailbox *mb = dev->mb_addr;
+ uint32_t cmd_head;
+
+ if (test_bit(TCMU_DEV_BIT_BROKEN, &dev->flags))
+ goto out_free;
+
+ id_list_sz = sizeof(tmr->tmr_cmd_ids[0]) * tmr->tmr_cmd_cnt;
+ cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE);
+
+ if (!list_empty(&dev->tmr_queue) ||
+ !is_ring_space_avail(dev, NULL, cmd_size, 0)) {
+ list_add_tail(&tmr->queue_entry, &dev->tmr_queue);
+ pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n",
+ tmr, dev->name);
+ return 1;
+ }
+
+ cmd_head = ring_insert_padding(dev, cmd_size);
+
+ entry = (void *)mb + CMDR_OFF + cmd_head;
+ memset(entry, 0, cmd_size);
+ tcmu_hdr_set_op(&entry->hdr.len_op, TCMU_OP_TMR);
+ tcmu_hdr_set_len(&entry->hdr.len_op, cmd_size);
+ entry->tmr_type = tmr->tmr_type;
+ entry->cmd_cnt = tmr->tmr_cmd_cnt;
+ memcpy(&entry->cmd_ids[0], &tmr->tmr_cmd_ids[0], id_list_sz);
+ tcmu_flush_dcache_range(entry, cmd_size);
+
+ UPDATE_HEAD(mb->cmd_head, cmd_size, dev->cmdr_size);
+ tcmu_flush_dcache_range(mb, sizeof(*mb));
+
+ uio_event_notify(&dev->uio_info);
+
+out_free:
+ kfree(tmr);
+
+ return 0;
+}
+
static sense_reason_t
tcmu_queue_cmd(struct se_cmd *se_cmd)
{
@@ -1141,6 +1209,85 @@ static void tcmu_set_next_deadline(struct list_head *queue,
del_timer(timer);
}
+static int
+tcmu_tmr_type(enum tcm_tmreq_table tmf)
+{
+ switch (tmf) {
+ case TMR_ABORT_TASK: return TCMU_TMR_ABORT_TASK;
+ case TMR_ABORT_TASK_SET: return TCMU_TMR_ABORT_TASK_SET;
+ case TMR_CLEAR_ACA: return TCMU_TMR_CLEAR_ACA;
+ case TMR_CLEAR_TASK_SET: return TCMU_TMR_CLEAR_TASK_SET;
+ case TMR_LUN_RESET: return TCMU_TMR_LUN_RESET;
+ case TMR_TARGET_WARM_RESET: return TCMU_TMR_TARGET_WARM_RESET;
+ case TMR_TARGET_COLD_RESET: return TCMU_TMR_TARGET_COLD_RESET;
+ case TMR_LUN_RESET_PRO: return TCMU_TMR_LUN_RESET_PRO;
+ default: return TCMU_TMR_UNKNOWN;
+ }
+}
+
+static void
+tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf,
+ struct list_head *cmd_list)
+{
+ int i = 0, cmd_cnt = 0;
+ bool unqueued = false;
+ uint16_t *cmd_ids = NULL;
+ struct tcmu_cmd *cmd;
+ struct se_cmd *se_cmd;
+ struct tcmu_tmr *tmr;
+ struct tcmu_dev *dev = TCMU_DEV(se_dev);
+
+ mutex_lock(&dev->cmdr_lock);
+
+ // First we check for aborted commands in qfull_queue
+ list_for_each_entry(se_cmd, cmd_list, state_list) {
+ i++;
+ if (!se_cmd->priv)
+ continue;
+ cmd = se_cmd->priv;
+ // Commands on qfull queue have no id yet
+ if (cmd->cmd_id) {
+ cmd_cnt++;
+ continue;
+ }
+ pr_debug("Removing aborted command %p from queue on dev %s.\n",
+ cmd, dev->name);
+
+ list_del_init(&cmd->queue_entry);
+ tcmu_free_cmd(cmd);
+ target_complete_cmd(se_cmd, SAM_STAT_TASK_ABORTED);
+ unqueued = true;
+ }
+ if (unqueued)
+ tcmu_set_next_deadline(&dev->qfull_queue, &dev->qfull_timer);
+
+ pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n",
+ tcmu_tmr_type(tmf), dev->name, i, cmd_cnt);
+
+ tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_KERNEL);
+ if (!tmr)
+ goto unlock;
+
+ tmr->tmr_type = tcmu_tmr_type(tmf);
+ tmr->tmr_cmd_cnt = cmd_cnt;
+
+ if (cmd_cnt != 0) {
+ cmd_cnt = 0;
+ list_for_each_entry(se_cmd, cmd_list, state_list) {
+ if (!se_cmd->priv)
+ continue;
+ cmd = se_cmd->priv;
+ if (cmd->cmd_id)
+ tmr->tmr_cmd_ids[cmd_cnt++] = cmd->cmd_id;
+ }
+ }
+
+ queue_tmr_ring(dev, tmr);
+
+unlock:
+ mutex_unlock(&dev->cmdr_lock);
+}
+
static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *entry)
{
struct se_cmd *se_cmd = cmd->se_cmd;
@@ -1208,11 +1355,43 @@ static void tcmu_handle_completion(struct tcmu_cmd *cmd, struct tcmu_cmd_entry *
tcmu_free_cmd(cmd);
}
+static int tcmu_run_tmr_queue(struct tcmu_dev *dev)
+{
+ struct tcmu_tmr *tmr, *tmp;
+ LIST_HEAD(tmrs);
+
+ if (list_empty(&dev->tmr_queue))
+ return 1;
+
+ pr_debug("running %s's tmr queue\n", dev->name);
+
+ list_splice_init(&dev->tmr_queue, &tmrs);
+
+ list_for_each_entry_safe(tmr, tmp, &tmrs, queue_entry) {
+ list_del_init(&tmr->queue_entry);
+
+ pr_debug("removing tmr %p on dev %s from queue\n",
+ tmr, dev->name);
+
+ if (queue_tmr_ring(dev, tmr)) {
+ pr_debug("ran out of space during tmr queue run\n");
+ /*
+ * tmr was requeued, so just put all tmrs back in
+ * the queue
+ */
+ list_splice_tail(&tmrs, &dev->tmr_queue);
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
{
struct tcmu_mailbox *mb;
struct tcmu_cmd *cmd;
- int handled = 0;
+ bool free_space = false;
if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags)) {
pr_err("ring broken, not handling completions\n");
@@ -1235,7 +1414,10 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
tcmu_flush_dcache_range(entry, ring_left < sizeof(*entry) ?
ring_left : sizeof(*entry));
- if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD) {
+ free_space = true;
+
+ if (tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_PAD ||
+ tcmu_hdr_get_op(entry->hdr.len_op) == TCMU_OP_TMR) {
UPDATE_HEAD(udev->cmdr_last_cleaned,
tcmu_hdr_get_len(entry->hdr.len_op),
udev->cmdr_size);
@@ -1256,9 +1438,9 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
UPDATE_HEAD(udev->cmdr_last_cleaned,
tcmu_hdr_get_len(entry->hdr.len_op),
udev->cmdr_size);
-
- handled++;
}
+ if (free_space)
+ free_space = tcmu_run_tmr_queue(udev);
if (atomic_read(&global_db_count) > tcmu_global_max_blocks &&
idr_is_empty(&udev->commands) && list_empty(&udev->qfull_queue)) {
@@ -1271,7 +1453,7 @@ static unsigned int tcmu_handle_completions(struct tcmu_dev *udev)
if (udev->cmd_time_out)
tcmu_set_next_deadline(&udev->inflight_queue, &udev->cmd_timer);
- return handled;
+ return free_space;
}
static void tcmu_check_expired_ring_cmd(struct tcmu_cmd *cmd)
@@ -1381,6 +1563,7 @@ static struct se_device *tcmu_alloc_device(struct se_hba *hba, const char *name)
INIT_LIST_HEAD(&udev->node);
INIT_LIST_HEAD(&udev->timedout_entry);
INIT_LIST_HEAD(&udev->qfull_queue);
+ INIT_LIST_HEAD(&udev->tmr_queue);
INIT_LIST_HEAD(&udev->inflight_queue);
idr_init(&udev->commands);
@@ -1455,8 +1638,8 @@ static int tcmu_irqcontrol(struct uio_info *info, s32 irq_on)
struct tcmu_dev *udev = container_of(info, struct tcmu_dev, uio_info);
mutex_lock(&udev->cmdr_lock);
- tcmu_handle_completions(udev);
- run_qfull_queue(udev, false);
+ if (tcmu_handle_completions(udev))
+ run_qfull_queue(udev, false);
mutex_unlock(&udev->cmdr_lock);
return 0;
@@ -1609,6 +1792,16 @@ static void tcmu_blocks_release(struct radix_tree_root *blocks,
}
}
+static void tcmu_remove_all_queued_tmr(struct tcmu_dev *dev)
+{
+ struct tcmu_tmr *tmr, *tmp;
+
+ list_for_each_entry_safe(tmr, tmp, &dev->tmr_queue, queue_entry) {
+ list_del_init(&tmr->queue_entry);
+ kfree(tmr);
+ }
+}
+
static void tcmu_dev_kref_release(struct kref *kref)
{
struct tcmu_dev *udev = container_of(kref, struct tcmu_dev, kref);
@@ -1631,6 +1824,8 @@ static void tcmu_dev_kref_release(struct kref *kref)
if (tcmu_check_and_free_pending_cmd(cmd) != 0)
all_expired = false;
}
+ // There can be left over TMR cmds. Remove them.
+ tcmu_remove_all_queued_tmr(udev);
if (!list_empty(&udev->qfull_queue))
all_expired = false;
idr_destroy(&udev->commands);
@@ -1885,7 +2080,9 @@ static int tcmu_configure_device(struct se_device *dev)
/* Initialise the mailbox of the ring buffer */
mb = udev->mb_addr;
mb->version = TCMU_MAILBOX_VERSION;
- mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC | TCMU_MAILBOX_FLAG_CAP_READ_LEN;
+ mb->flags = TCMU_MAILBOX_FLAG_CAP_OOOC |
+ TCMU_MAILBOX_FLAG_CAP_READ_LEN |
+ TCMU_MAILBOX_FLAG_CAP_TMR;
mb->cmdr_off = CMDR_OFF;
mb->cmdr_size = udev->cmdr_size;
@@ -2055,6 +2252,15 @@ static void tcmu_reset_ring(struct tcmu_dev *udev, u8 err_level)
del_timer(&udev->cmd_timer);
+ /*
+ * ring is empty and qfull queue never contains aborted commands.
+ * So TMRs in tmr queue do not contain relevant cmd_ids.
+ * After a ring reset userspace should do a fresh start, so
+ * even LUN RESET message is no longer relevant.
+ * Therefore remove all TMRs from qfull queue
+ */
+ tcmu_remove_all_queued_tmr(udev);
+
run_qfull_queue(udev, false);
mutex_unlock(&udev->cmdr_lock);
@@ -2607,6 +2813,7 @@ static struct target_backend_ops tcmu_ops = {
.destroy_device = tcmu_destroy_device,
.free_device = tcmu_free_device,
.parse_cdb = tcmu_parse_cdb,
+ .tmr_notify = tcmu_tmr_notify,
.set_configfs_dev_params = tcmu_set_configfs_dev_params,
.show_configfs_dev_params = tcmu_show_configfs_dev_params,
.get_device_type = sbc_get_device_type,
@@ -2633,7 +2840,8 @@ static void find_free_blocks(void)
}
/* Try to complete the finished commands first */
- tcmu_handle_completions(udev);
+ if (tcmu_handle_completions(udev))
+ run_qfull_queue(udev, false);
/* Skip the udevs in idle */
if (!udev->dbi_thresh) {
diff --git a/include/uapi/linux/target_core_user.h b/include/uapi/linux/target_core_user.h
index b7b57967d90f..95b1597f16ae 100644
--- a/include/uapi/linux/target_core_user.h
+++ b/include/uapi/linux/target_core_user.h
@@ -45,6 +45,7 @@
#define ALIGN_SIZE 64 /* Should be enough for most CPUs */
#define TCMU_MAILBOX_FLAG_CAP_OOOC (1 << 0) /* Out-of-order completions */
#define TCMU_MAILBOX_FLAG_CAP_READ_LEN (1 << 1) /* Read data length */
+#define TCMU_MAILBOX_FLAG_CAP_TMR (1 << 2) /* TMR notifications */
struct tcmu_mailbox {
__u16 version;
@@ -62,6 +63,7 @@ struct tcmu_mailbox {
enum tcmu_opcode {
TCMU_OP_PAD = 0,
TCMU_OP_CMD,
+ TCMU_OP_TMR,
};
/*
@@ -128,6 +130,29 @@ struct tcmu_cmd_entry {
} __packed;
+struct tcmu_tmr_entry {
+ struct tcmu_cmd_entry_hdr hdr;
+
+#define TCMU_TMR_UNKNOWN 0
+#define TCMU_TMR_ABORT_TASK 1
+#define TCMU_TMR_ABORT_TASK_SET 2
+#define TCMU_TMR_CLEAR_ACA 3
+#define TCMU_TMR_CLEAR_TASK_SET 4
+#define TCMU_TMR_LUN_RESET 5
+#define TCMU_TMR_TARGET_WARM_RESET 6
+#define TCMU_TMR_TARGET_COLD_RESET 7
+/* Pseudo reset due to received PR OUT */
+#define TCMU_TMR_LUN_RESET_PRO 128
+ __u8 tmr_type;
+
+ __u8 __pad1;
+ __u16 __pad2;
+ __u32 cmd_cnt;
+ __u64 __pad3;
+ __u64 __pad4;
+ __u16 cmd_ids[0];
+} __packed;
+
#define TCMU_OP_ALIGN_SIZE sizeof(__u64)
enum tcmu_genl_cmd {
--
2.12.3
