From 76e74bbe0a38c6720217425ed64dbb448c643b9d Mon Sep 17 00:00:00 2001 From: Dwight Engen Date: Thu, 11 Dec 2014 12:26:17 -0500 Subject: [PATCH] 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 Reviewed-by: Chris Hyser Signed-off-by: David S. Miller --- drivers/block/sunvdc.c | 205 ++++++++++++++++++++++++++++++++++++----- 1 file 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 = ∁ 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);