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authorDwight Engen <dwight.engen@oracle.com>2014-12-11 20:26:17 +0300
committerDavid S. Miller <davem@davemloft.net>2014-12-12 05:52:45 +0300
commit76e74bbe0a38c6720217425ed64dbb448c643b9d (patch)
treee66d6c9c301acf4462e46c713fe072e8e167f907 /drivers/block/sunvdc.c
parent1678c2bd131313b58c7492487c00dca982be7f28 (diff)
downloadlinux-76e74bbe0a38c6720217425ed64dbb448c643b9d.tar.xz
sunvdc: reconnect ldc after vds service domain restarts
This change enables the sunvdc driver to reconnect and recover if a vds service domain is disconnected or bounced. By default, it will wait indefinitely for the service domain to become available again, but will honor a non-zero vdc-timout md property if one is set. If a timeout is reached, any in-progress I/O's are completed with -EIO. Signed-off-by: Dwight Engen <dwight.engen@oracle.com> Reviewed-by: Chris Hyser <chris.hyser@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/block/sunvdc.c')
-rw-r--r--drivers/block/sunvdc.c205
1 files changed, 183 insertions, 22 deletions
diff --git a/drivers/block/sunvdc.c b/drivers/block/sunvdc.c
index 65cec156cfb4..4b911ed96ea3 100644
--- a/drivers/block/sunvdc.c
+++ b/drivers/block/sunvdc.c
@@ -23,8 +23,8 @@
#define DRV_MODULE_NAME "sunvdc"
#define PFX DRV_MODULE_NAME ": "
-#define DRV_MODULE_VERSION "1.1"
-#define DRV_MODULE_RELDATE "February 13, 2013"
+#define DRV_MODULE_VERSION "1.2"
+#define DRV_MODULE_RELDATE "November 24, 2014"
static char version[] =
DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n";
@@ -40,6 +40,8 @@ MODULE_VERSION(DRV_MODULE_VERSION);
#define WAITING_FOR_GEN_CMD 0x04
#define WAITING_FOR_ANY -1
+static struct workqueue_struct *sunvdc_wq;
+
struct vdc_req_entry {
struct request *req;
};
@@ -60,6 +62,10 @@ struct vdc_port {
u64 max_xfer_size;
u32 vdisk_block_size;
+ u64 ldc_timeout;
+ struct timer_list ldc_reset_timer;
+ struct work_struct ldc_reset_work;
+
/* The server fills these in for us in the disk attribute
* ACK packet.
*/
@@ -71,6 +77,10 @@ struct vdc_port {
char disk_name[32];
};
+static void vdc_ldc_reset(struct vdc_port *port);
+static void vdc_ldc_reset_work(struct work_struct *work);
+static void vdc_ldc_reset_timer(unsigned long _arg);
+
static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio)
{
return container_of(vio, struct vdc_port, vio);
@@ -150,6 +160,21 @@ static const struct block_device_operations vdc_fops = {
.ioctl = vdc_ioctl,
};
+static void vdc_blk_queue_start(struct vdc_port *port)
+{
+ struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
+
+ /* restart blk queue when ring is half emptied. also called after
+ * handshake completes, so check for initial handshake before we've
+ * allocated a disk.
+ */
+ if (port->disk && blk_queue_stopped(port->disk->queue) &&
+ vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50) {
+ blk_start_queue(port->disk->queue);
+ }
+
+}
+
static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
{
if (vio->cmp &&
@@ -163,7 +188,11 @@ static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for)
static void vdc_handshake_complete(struct vio_driver_state *vio)
{
+ struct vdc_port *port = to_vdc_port(vio);
+
+ del_timer(&port->ldc_reset_timer);
vdc_finish(vio, 0, WAITING_FOR_LINK_UP);
+ vdc_blk_queue_start(port);
}
static int vdc_handle_unknown(struct vdc_port *port, void *arg)
@@ -281,10 +310,7 @@ static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
__blk_end_request(req, (desc->status ? -EIO : 0), desc->size);
- /* restart blk queue when ring is half emptied */
- if (blk_queue_stopped(port->disk->queue) &&
- vdc_tx_dring_avail(dr) * 100 / VDC_TX_RING_SIZE >= 50)
- blk_start_queue(port->disk->queue);
+ vdc_blk_queue_start(port);
}
static int vdc_ack(struct vdc_port *port, void *msgbuf)
@@ -317,17 +343,20 @@ static void vdc_event(void *arg, int event)
spin_lock_irqsave(&vio->lock, flags);
- if (unlikely(event == LDC_EVENT_RESET ||
- event == LDC_EVENT_UP)) {
+ if (unlikely(event == LDC_EVENT_RESET)) {
vio_link_state_change(vio, event);
- spin_unlock_irqrestore(&vio->lock, flags);
- return;
+ queue_work(sunvdc_wq, &port->ldc_reset_work);
+ goto out;
+ }
+
+ if (unlikely(event == LDC_EVENT_UP)) {
+ vio_link_state_change(vio, event);
+ goto out;
}
if (unlikely(event != LDC_EVENT_DATA_READY)) {
- printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event);
- spin_unlock_irqrestore(&vio->lock, flags);
- return;
+ pr_warn(PFX "Unexpected LDC event %d\n", event);
+ goto out;
}
err = 0;
@@ -371,6 +400,7 @@ static void vdc_event(void *arg, int event)
}
if (err < 0)
vdc_finish(&port->vio, err, WAITING_FOR_ANY);
+out:
spin_unlock_irqrestore(&vio->lock, flags);
}
@@ -403,6 +433,8 @@ static int __vdc_tx_trigger(struct vdc_port *port)
delay = 128;
} while (err == -EAGAIN);
+ if (err == -ENOTCONN)
+ vdc_ldc_reset(port);
return err;
}
@@ -690,12 +722,9 @@ static void vdc_free_tx_ring(struct vdc_port *port)
}
}
-static int probe_disk(struct vdc_port *port)
+static int vdc_port_up(struct vdc_port *port)
{
struct vio_completion comp;
- struct request_queue *q;
- struct gendisk *g;
- int err;
init_completion(&comp.com);
comp.err = 0;
@@ -703,10 +732,27 @@ static int probe_disk(struct vdc_port *port)
port->vio.cmp = &comp;
vio_port_up(&port->vio);
-
wait_for_completion(&comp.com);
- if (comp.err)
- return comp.err;
+ return comp.err;
+}
+
+static void vdc_port_down(struct vdc_port *port)
+{
+ ldc_disconnect(port->vio.lp);
+ ldc_unbind(port->vio.lp);
+ vdc_free_tx_ring(port);
+ vio_ldc_free(&port->vio);
+}
+
+static int probe_disk(struct vdc_port *port)
+{
+ struct request_queue *q;
+ struct gendisk *g;
+ int err;
+
+ err = vdc_port_up(port);
+ if (err)
+ return err;
if (vdc_version_supported(port, 1, 1)) {
/* vdisk_size should be set during the handshake, if it wasn't
@@ -819,6 +865,7 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
struct mdesc_handle *hp;
struct vdc_port *port;
int err;
+ const u64 *ldc_timeout;
print_version();
@@ -848,6 +895,16 @@ static int vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id)
VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26));
port->vdisk_size = -1;
+ /* Actual wall time may be double due to do_generic_file_read() doing
+ * a readahead I/O first, and once that fails it will try to read a
+ * single page.
+ */
+ ldc_timeout = mdesc_get_property(hp, vdev->mp, "vdc-timeout", NULL);
+ port->ldc_timeout = ldc_timeout ? *ldc_timeout : 0;
+ setup_timer(&port->ldc_reset_timer, vdc_ldc_reset_timer,
+ (unsigned long)port);
+ INIT_WORK(&port->ldc_reset_work, vdc_ldc_reset_work);
+
err = vio_driver_init(&port->vio, vdev, VDEV_DISK,
vdc_versions, ARRAY_SIZE(vdc_versions),
&vdc_vio_ops, port->disk_name);
@@ -902,6 +959,8 @@ static int vdc_port_remove(struct vio_dev *vdev)
blk_stop_queue(port->disk->queue);
spin_unlock_irqrestore(&port->vio.lock, flags);
+ flush_work(&port->ldc_reset_work);
+ del_timer_sync(&port->ldc_reset_timer);
del_timer_sync(&port->vio.timer);
del_gendisk(port->disk);
@@ -919,6 +978,102 @@ static int vdc_port_remove(struct vio_dev *vdev)
return 0;
}
+static void vdc_requeue_inflight(struct vdc_port *port)
+{
+ struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING];
+ u32 idx;
+
+ for (idx = dr->cons; idx != dr->prod; idx = vio_dring_next(dr, idx)) {
+ struct vio_disk_desc *desc = vio_dring_entry(dr, idx);
+ struct vdc_req_entry *rqe = &port->rq_arr[idx];
+ struct request *req;
+
+ ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies);
+ desc->hdr.state = VIO_DESC_FREE;
+ dr->cons = vio_dring_next(dr, idx);
+
+ req = rqe->req;
+ if (req == NULL) {
+ vdc_end_special(port, desc);
+ continue;
+ }
+
+ rqe->req = NULL;
+ blk_requeue_request(port->disk->queue, req);
+ }
+}
+
+static void vdc_queue_drain(struct vdc_port *port)
+{
+ struct request *req;
+
+ while ((req = blk_fetch_request(port->disk->queue)) != NULL)
+ __blk_end_request_all(req, -EIO);
+}
+
+static void vdc_ldc_reset_timer(unsigned long _arg)
+{
+ struct vdc_port *port = (struct vdc_port *) _arg;
+ struct vio_driver_state *vio = &port->vio;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vio->lock, flags);
+ if (!(port->vio.hs_state & VIO_HS_COMPLETE)) {
+ pr_warn(PFX "%s ldc down %llu seconds, draining queue\n",
+ port->disk_name, port->ldc_timeout);
+ vdc_queue_drain(port);
+ vdc_blk_queue_start(port);
+ }
+ spin_unlock_irqrestore(&vio->lock, flags);
+}
+
+static void vdc_ldc_reset_work(struct work_struct *work)
+{
+ struct vdc_port *port;
+ struct vio_driver_state *vio;
+ unsigned long flags;
+
+ port = container_of(work, struct vdc_port, ldc_reset_work);
+ vio = &port->vio;
+
+ spin_lock_irqsave(&vio->lock, flags);
+ vdc_ldc_reset(port);
+ spin_unlock_irqrestore(&vio->lock, flags);
+}
+
+static void vdc_ldc_reset(struct vdc_port *port)
+{
+ int err;
+
+ assert_spin_locked(&port->vio.lock);
+
+ pr_warn(PFX "%s ldc link reset\n", port->disk_name);
+ blk_stop_queue(port->disk->queue);
+ vdc_requeue_inflight(port);
+ vdc_port_down(port);
+
+ err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port);
+ if (err) {
+ pr_err(PFX "%s vio_ldc_alloc:%d\n", port->disk_name, err);
+ return;
+ }
+
+ err = vdc_alloc_tx_ring(port);
+ if (err) {
+ pr_err(PFX "%s vio_alloc_tx_ring:%d\n", port->disk_name, err);
+ goto err_free_ldc;
+ }
+
+ if (port->ldc_timeout)
+ mod_timer(&port->ldc_reset_timer,
+ round_jiffies(jiffies + HZ * port->ldc_timeout));
+ mod_timer(&port->vio.timer, round_jiffies(jiffies + HZ));
+ return;
+
+err_free_ldc:
+ vio_ldc_free(&port->vio);
+}
+
static const struct vio_device_id vdc_port_match[] = {
{
.type = "vdc-port",
@@ -938,9 +1093,13 @@ static int __init vdc_init(void)
{
int err;
+ sunvdc_wq = alloc_workqueue("sunvdc", 0, 0);
+ if (!sunvdc_wq)
+ return -ENOMEM;
+
err = register_blkdev(0, VDCBLK_NAME);
if (err < 0)
- goto out_err;
+ goto out_free_wq;
vdc_major = err;
@@ -954,7 +1113,8 @@ out_unregister_blkdev:
unregister_blkdev(vdc_major, VDCBLK_NAME);
vdc_major = 0;
-out_err:
+out_free_wq:
+ destroy_workqueue(sunvdc_wq);
return err;
}
@@ -962,6 +1122,7 @@ static void __exit vdc_exit(void)
{
vio_unregister_driver(&vdc_port_driver);
unregister_blkdev(vdc_major, VDCBLK_NAME);
+ destroy_workqueue(sunvdc_wq);
}
module_init(vdc_init);