SPARC64: UEK4 LDOMS DOMAIN SERVICES UPDATE 3

  This update provides the following fix for LDom domain services on UEK4.

  1. Add an event to the vlds driver which is used to signal
  process(es) using libds that the vlds /dev devices have been updated.
  When it receives this event, libds will refresh/update it's internal
  list of vlds devices allowing the list to stay immediately up-to-date
  when vlds devices have changed. This event fixes some DR related libds
  problems found during regression testing due to libds internal vlds
  device list becoming stale.

  Signed-off-by: Aaron Young <aaron.young@oracle.com>
  Reviewed-by: Alexandre Chartre <Alexandre.Chartre@oracle.com>
  Orabug: 22853109

(cherry picked from commit 1722beeac0278656731b8f0da394fb2f6a0b17b3)
(cherry picked from commit 80d160e808f283c1438e8681eedfee287f53a955)
Signed-off-by: Allen Pais <allen.pais@oracle.com>

diff --git a/drivers/char/vlds.c b/drivers/char/vlds.c
index 8d5498058187530fb21be0eddf1a606713b25e57..7f38f6e92b6a8b0984a0f8996efddb3548439ea3 100644 (file)
--- a/drivers/char/vlds.c
+++ b/drivers/char/vlds.c
@@ -1,7 +1,7 @@
 /*
  * vlds.c: Sun4v LDOMs Virtual Domain Services Driver
  *
- * Copyright (C) 2015 Oracle. All rights reserved.
+ * Copyright (C) 2015, 2016 Oracle. All rights reserved.
  */
 #include <linux/cdev.h>
 #include <linux/device.h>
@@ -289,47 +289,11 @@ static void vlds_remove_event_info(pid_t tgid)
 
 }
 
-static int vlds_add_event(pid_t tgid, struct vlds_service_info *svc_info,
-       u64 type, vlds_ver_t *neg_vers)
+static int vlds_signal_event(pid_t tgid, int fd)
 {
-       struct vlds_event_info *event_info;
-       struct vlds_event *event;
-       struct task_struct *utask;
        struct file *efd_file;
        struct eventfd_ctx *efd_ctx;
-       int rv;
-
-       mutex_lock(&vlds_event_info_list_mutex);
-
-       event_info = NULL;
-       rv = vlds_get_event_info(tgid, &event_info);
-       if (rv || event_info == NULL) {
-               /*
-                * If we failed to find an event_info, it probably just
-                * means the process did not register for events in favor
-                * of using polling - which is valid.
-                */
-               mutex_unlock(&vlds_event_info_list_mutex);
-               return 0;
-       }
-
-       event = kzalloc(sizeof(struct vlds_event), GFP_KERNEL);
-       if (unlikely(event == NULL)) {
-               dprintk("failed to allocate event for "
-                   "service %llx\n", svc_info->handle);
-               mutex_unlock(&vlds_event_info_list_mutex);
-               return -ENOMEM;
-       } else {
-               event->type = type;
-               event->svc_info = svc_info;
-               if (neg_vers != NULL)
-                       event->neg_vers = *neg_vers;
-
-               list_add_tail(&event->list,
-                   &event_info->event_list);
-       }
-
-       mutex_unlock(&vlds_event_info_list_mutex);
+       struct task_struct *utask;
 
        /*
         * Signal the process that there is an event pending
@@ -347,8 +311,8 @@ static int vlds_add_event(pid_t tgid, struct vlds_service_info *svc_info,
                return -EIO;
        }
 
-       /* Get the file corresponding to event_info->fd */
-       efd_file = fcheck_files(utask->files, event_info->fd);
+       /* Get the file corresponding to fd */
+       efd_file = fcheck_files(utask->files, fd);
        if (!efd_file) {
                rcu_read_unlock();
                return -EIO;
@@ -369,12 +333,89 @@ static int vlds_add_event(pid_t tgid, struct vlds_service_info *svc_info,
 
        rcu_read_unlock();
 
+       return 0;
+}
+
+/* vlds_dev_mutex must be held */
+static void vlds_add_event_all(struct vlds_dev *vlds, u64 type)
+{
+       struct vlds_event_info *event_info;
+       struct vlds_event *event;
+       int rv;
+
+       mutex_lock(&vlds_event_info_list_mutex);
+
+       list_for_each_entry(event_info, &vlds_event_info_list, list) {
+
+               event = kzalloc(sizeof(struct vlds_event), GFP_KERNEL);
+               if (unlikely(event == NULL)) {
+                       dprintk("failed to allocate event %llu for tgid=%u\n",
+                           type, event_info->tgid);
+               } else {
+                       event->type = type;
+                       list_add_tail(&event->list,
+                           &event_info->event_list);
+               }
+
+               rv = vlds_signal_event(event_info->tgid, event_info->fd);
+               if (rv) {
+                       /* just give an error if we failed to add the event */
+                       pr_err("%s: Failed to create %llu event for tgid=%u\n",
+                           vlds->int_name, type, event_info->tgid);
+               }
+       }
+
+       mutex_unlock(&vlds_event_info_list_mutex);
+}
+
+static int vlds_add_svc_event(pid_t tgid, struct vlds_service_info *svc_info,
+       u64 type, vlds_ver_t *neg_vers)
+{
+       struct vlds_event_info *event_info;
+       struct vlds_event *event;
+       int rv;
+
+       mutex_lock(&vlds_event_info_list_mutex);
+
+       event_info = NULL;
+       rv = vlds_get_event_info(tgid, &event_info);
+       if (rv || event_info == NULL) {
+               /*
+                * If we failed to find an event_info, it probably just
+                * means the process did not register for events in favor
+                * of using polling - which is valid.
+                */
+               mutex_unlock(&vlds_event_info_list_mutex);
+               return 0;
+       }
+
+       event = kzalloc(sizeof(struct vlds_event), GFP_KERNEL);
+       if (unlikely(event == NULL)) {
+               if (svc_info)
+                       dprintk("failed to allocate event for "
+                           "service %llx\n", svc_info->handle);
+               mutex_unlock(&vlds_event_info_list_mutex);
+               return -ENOMEM;
+       }
+
+       event->type = type;
+       event->svc_info = svc_info;
+       if (neg_vers != NULL)
+               event->neg_vers = *neg_vers;
+
+       list_add_tail(&event->list,
+           &event_info->event_list);
+
+       rv = vlds_signal_event(tgid, event_info->fd);
+
+       mutex_unlock(&vlds_event_info_list_mutex);
+
        return rv;
 
 }
 
 /* vlds_dev_mutex must be held */
-static void vlds_add_event_all(struct vlds_dev *vlds,
+static void vlds_add_event_svc_all(struct vlds_dev *vlds,
        struct vlds_service_info *svc_info, u64 type, vlds_ver_t *neg_vers)
 {
        struct vlds_tgid_info *tgid_info;
@@ -386,7 +427,7 @@ static void vlds_add_event_all(struct vlds_dev *vlds,
                if (!tgid_info->event_reg)
                        continue;
 
-               rv = vlds_add_event(tgid_info->tgid, svc_info,
+               rv = vlds_add_svc_event(tgid_info->tgid, svc_info,
                    type, neg_vers);
                if (rv) {
                        /* just give an error if we failed to add the event */
@@ -445,7 +486,7 @@ static void vlds_remove_svc_events_tgid(struct vlds_service_info *svc_info,
        if (rv == 0 && event_info != NULL) {
                list_for_each_entry_safe(event, next, &event_info->event_list,
                    list) {
-                       if (event->svc_info == svc_info)
+                       if (event->svc_info && event->svc_info == svc_info)
                                vlds_remove_event(event_info, event);
                }
        }
@@ -732,7 +773,7 @@ vlds_ds_reg_cb(ds_cb_arg_t arg, ds_svc_hdl_t hdl, ds_ver_t *ver)
         * For every process that has registered this service
         * in EVENT mode, register an event.
         */
-       vlds_add_event_all(vlds, svc_info, VLDS_EVENT_TYPE_REG,
+       vlds_add_event_svc_all(vlds, svc_info, VLDS_EVENT_TYPE_REG,
            &svc_info->neg_vers);
 
        dprintk("%s: service %s register version (%u.%u) hdl=%llx\n",
@@ -771,7 +812,7 @@ vlds_ds_unreg_cb(ds_cb_arg_t arg, ds_svc_hdl_t hdl)
         * For every process that has registered this service
         * in EVENT mode, register an event.
         */
-       vlds_add_event_all(vlds, svc_info, VLDS_EVENT_TYPE_UNREG, NULL);
+       vlds_add_event_svc_all(vlds, svc_info, VLDS_EVENT_TYPE_UNREG, NULL);
 
        dprintk("%s: service %s unregister hdl=%llx\n",
            vlds->int_name, svc_info->name, hdl);
@@ -812,7 +853,7 @@ vlds_ds_data_cb(ds_cb_arg_t arg, ds_svc_hdl_t hdl, void *buf, size_t buflen)
         * For every process that has registered this service
         * in EVENT mode, register an event.
         */
-       vlds_add_event_all(vlds, svc_info, VLDS_EVENT_TYPE_DATA, NULL);
+       vlds_add_event_svc_all(vlds, svc_info, VLDS_EVENT_TYPE_DATA, NULL);
 
        dprintk("%s: service %s: Received %lu bytes hdl=%llx\n",
            vlds->int_name, svc_info->name, buflen, hdl);
@@ -975,7 +1016,7 @@ static int vlds_svc_reg(struct vlds_dev *vlds, const void __user *uarg)
                 */
                if (is_event_reg &&
                    svc_info->state == VLDS_HDL_STATE_CONNECTED) {
-                       rv = vlds_add_event(tgid, svc_info,
+                       rv = vlds_add_svc_event(tgid, svc_info,
                            VLDS_EVENT_TYPE_REG, &svc_info->neg_vers);
                        if (rv) {
                                /* just give an error if add event fails */
@@ -1761,10 +1802,12 @@ static int vlds_get_next_event(struct vlds_dev *vlds, const void __user *uarg)
        }
 
        /* populate the return event handle */
-       if (put_user(event->svc_info->handle,
-           (u64 __user *)(next_event.vlds_hdlp)) != 0) {
-               rv = -EFAULT;
-               goto error_out2;
+       if (event->svc_info) {
+               if (put_user(event->svc_info->handle,
+                   (u64 __user *)(next_event.vlds_hdlp)) != 0) {
+                       rv = -EFAULT;
+                       goto error_out2;
+               }
        }
 
        /* populate the return event type */
@@ -2404,6 +2447,11 @@ static int vlds_probe(struct vio_dev *vdev, const struct vio_device_id *vio_did)
 
        dev_set_drvdata(&vdev->dev, vlds);
 
+       mutex_lock(&vlds->vlds_mutex);
+       /* Register a device update event */
+       vlds_add_event_all(vlds, VLDS_EVENT_TYPE_DEVICE_UPDATE);
+       mutex_unlock(&vlds->vlds_mutex);
+
        dprintk("%s: Probe successfful: cfg_handle=%llu, id=%llu\n",
            vlds->int_name, vdev->dev_no, *id);
 
@@ -2438,6 +2486,9 @@ static int vlds_remove(struct vio_dev *vdev)
        device_destroy(vlds_data.chrdev_class, vlds->devt);
        cdev_del(&vlds->cdev);
 
+       /* Register a device update event */
+       vlds_add_event_all(vlds, VLDS_EVENT_TYPE_DEVICE_UPDATE);
+
        /*
         * If there are still outstanding references (opens)
         * on this device, then set a flag and remove it on

diff --git a/include/uapi/linux/vlds.h b/include/uapi/linux/vlds.h
index bd064ef351226d3b1be6d3ad9f1aa64400bd5522..2c2f72d7dedd9963bafc89f691cbd5c7619636d5 100644 (file)
--- a/include/uapi/linux/vlds.h
+++ b/include/uapi/linux/vlds.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015 Oracle Corporation
+ * Copyright (C) 2015, 2016 Oracle. All rights reserved.
  */
 
 #ifndef _UAPI_VLDS_H
@@ -97,8 +97,8 @@ typedef struct vlds_set_event_fd_arg {
 } vlds_set_event_fd_arg_t;
 
 typedef struct vlds_get_next_event_arg {
-       u64     vlds_hdlp;      /* Event Service Handle (returned) */
-       u64     vlds_event_typep; /* Reg, Unreg or Data event? (returned) */
+       u64     vlds_hdlp;      /* Reg/Unreg/Data Service Handle (returned) */
+       u64     vlds_event_typep; /* Event type (returned) */
        u64     neg_versp;      /* reg event negotiated version (returned) */
        u64     vlds_bufp;      /* data event msg buffer (returned) */
        u64     vlds_buflen;    /* data event msg buffer size */
@@ -108,6 +108,7 @@ typedef struct vlds_get_next_event_arg {
 #define        VLDS_EVENT_TYPE_REG                     0x0
 #define        VLDS_EVENT_TYPE_UNREG                   0x1
 #define        VLDS_EVENT_TYPE_DATA                    0x2
+#define        VLDS_EVENT_TYPE_DEVICE_UPDATE           0x3
 
 #define VLDS_IOCTL_BASE                'D'