Merge branch 'for-2.6.38/event-handling' into for-next

15 files changed, 779 insertions, 270 deletions

diff --git a/block/genhd.c b/block/genhd.c
index 5fa2b44a72ff..5465a824d489 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -18,6 +18,7 @@
 #include <linux/buffer_head.h>
 #include <linux/mutex.h>
 #include <linux/idr.h>
+#include <linux/log2.h>
 
 #include "blk.h"
 
@@ -35,6 +36,10 @@ static DEFINE_IDR(ext_devt_idr);
 
 static struct device_type disk_type;
 
+static void disk_add_events(struct gendisk *disk);
+static void disk_del_events(struct gendisk *disk);
+static void disk_release_events(struct gendisk *disk);
+
 /**
  * disk_get_part - get partition
  * @disk: disk to look partition from
@@ -502,6 +507,64 @@ static int exact_lock(dev_t devt, void *data)
         return 0;
 }
 
+void register_disk(struct gendisk *disk)
+{
+        struct device *ddev = disk_to_dev(disk);
+        struct block_device *bdev;
+        struct disk_part_iter piter;
+        struct hd_struct *part;
+        int err;
+
+        ddev->parent = disk->driverfs_dev;
+
+        dev_set_name(ddev, disk->disk_name);
+
+        /* delay uevents, until we scanned partition table */
+        dev_set_uevent_suppress(ddev, 1);
+
+        if (device_add(ddev))
+                return;
+        if (!sysfs_deprecated) {
+                err = sysfs_create_link(block_depr, &ddev->kobj,
+                                        kobject_name(&ddev->kobj));
+                if (err) {
+                        device_del(ddev);
+                        return;
+                }
+        }
+        disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
+        disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
+
+        /* No minors to use for partitions */
+        if (!disk_partitionable(disk))
+                goto exit;
+
+        /* No such device (e.g., media were just removed) */
+        if (!get_capacity(disk))
+                goto exit;
+
+        bdev = bdget_disk(disk, 0);
+        if (!bdev)
+                goto exit;
+
+        bdev->bd_invalidated = 1;
+        err = blkdev_get(bdev, FMODE_READ, NULL);
+        if (err < 0)
+                goto exit;
+        blkdev_put(bdev, FMODE_READ);
+
+exit:
+        /* announce disk after possible partitions are created */
+        dev_set_uevent_suppress(ddev, 0);
+        kobject_uevent(&ddev->kobj, KOBJ_ADD);
+
+        /* announce possible partitions */
+        disk_part_iter_init(&piter, disk, 0);
+        while ((part = disk_part_iter_next(&piter)))
+                kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
+        disk_part_iter_exit(&piter);
+}
+
 /**
  * add_disk - add partitioning information to kernel list
  * @disk: per-device partitioning information
@@ -551,18 +614,48 @@ void add_disk(struct gendisk *disk)
         retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
                                    "bdi");
         WARN_ON(retval);
-}
 
+        disk_add_events(disk);
+}
 EXPORT_SYMBOL(add_disk);
-EXPORT_SYMBOL(del_gendisk);     /* in partitions/check.c */
 
-void unlink_gendisk(struct gendisk *disk)
+void del_gendisk(struct gendisk *disk)
 {
+        struct disk_part_iter piter;
+        struct hd_struct *part;
+
+        disk_del_events(disk);
+
+        /* invalidate stuff */
+        disk_part_iter_init(&piter, disk,
+                             DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
+        while ((part = disk_part_iter_next(&piter))) {
+                invalidate_partition(disk, part->partno);
+                delete_partition(disk, part->partno);
+        }
+        disk_part_iter_exit(&piter);
+
+        invalidate_partition(disk, 0);
+        blk_free_devt(disk_to_dev(disk)->devt);
+        set_capacity(disk, 0);
+        disk->flags &= ~GENHD_FL_UP;
+
         sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
         bdi_unregister(&disk->queue->backing_dev_info);
         blk_unregister_queue(disk);
         blk_unregister_region(disk_devt(disk), disk->minors);
+
+        part_stat_set_all(&disk->part0, 0);
+        disk->part0.stamp = 0;
+
+        kobject_put(disk->part0.holder_dir);
+        kobject_put(disk->slave_dir);
+        disk->driverfs_dev = NULL;
+        if (!sysfs_deprecated)
+                sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
+        device_del(disk_to_dev(disk));
 }
+EXPORT_SYMBOL(del_gendisk);
 
 /**
  * get_gendisk - get partitioning information for a given device
@@ -1005,6 +1098,7 @@ static void disk_release(struct device *dev)
 {
         struct gendisk *disk = dev_to_disk(dev);
 
+        disk_release_events(disk);
         kfree(disk->random);
         disk_replace_part_tbl(disk, NULL);
         free_part_stats(&disk->part0);
@@ -1110,29 +1204,6 @@ static int __init proc_genhd_init(void)
 module_init(proc_genhd_init);
 #endif /* CONFIG_PROC_FS */
 
-static void media_change_notify_thread(struct work_struct *work)
-{
-        struct gendisk *gd = container_of(work, struct gendisk, async_notify);
-        char event[] = "MEDIA_CHANGE=1";
-        char *envp[] = { event, NULL };
-
-        /*
-         * set enviroment vars to indicate which event this is for
-         * so that user space will know to go check the media status.
-         */
-        kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
-        put_device(gd->driverfs_dev);
-}
-
-#if 0
-void genhd_media_change_notify(struct gendisk *disk)
-{
-        get_device(disk->driverfs_dev);
-        schedule_work(&disk->async_notify);
-}
-EXPORT_SYMBOL_GPL(genhd_media_change_notify);
-#endif  /*  0  */
-
 dev_t blk_lookup_devt(const char *name, int partno)
 {
         dev_t devt = MKDEV(0, 0);
@@ -1198,8 +1269,6 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
                 disk_to_dev(disk)->class = &block_class;
                 disk_to_dev(disk)->type = &disk_type;
                 device_initialize(disk_to_dev(disk));
-                INIT_WORK(&disk->async_notify,
-                        media_change_notify_thread);
         }
         return disk;
 }
@@ -1291,3 +1360,422 @@ int invalidate_partition(struct gendisk *disk, int partno)
 }
 
 EXPORT_SYMBOL(invalidate_partition);
+
+/*
+ * Disk events - monitor disk events like media change and eject request.
+ */
+struct disk_events {
+        struct list_head        node;           /* all disk_event's */
+        struct gendisk          *disk;          /* the associated disk */
+        spinlock_t              lock;
+
+        int                     block;          /* event blocking depth */
+        unsigned int            pending;        /* events already sent out */
+        unsigned int            clearing;       /* events being cleared */
+
+        long                    poll_msecs;     /* interval, -1 for default */
+        struct delayed_work     dwork;
+};
+
+static const char *disk_events_strs[] = {
+        [ilog2(DISK_EVENT_MEDIA_CHANGE)]        = "media_change",
+        [ilog2(DISK_EVENT_EJECT_REQUEST)]       = "eject_request",
+};
+
+static char *disk_uevents[] = {
+        [ilog2(DISK_EVENT_MEDIA_CHANGE)]        = "DISK_MEDIA_CHANGE=1",
+        [ilog2(DISK_EVENT_EJECT_REQUEST)]       = "DISK_EJECT_REQUEST=1",
+};
+
+/* list of all disk_events */
+static DEFINE_MUTEX(disk_events_mutex);
+static LIST_HEAD(disk_events);
+
+/* disable in-kernel polling by default */
+static unsigned long disk_events_dfl_poll_msecs = 0;
+
+static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
+{
+        struct disk_events *ev = disk->ev;
+        long intv_msecs = 0;
+
+        /*
+         * If device-specific poll interval is set, always use it.  If
+         * the default is being used, poll iff there are events which
+         * can't be monitored asynchronously.
+         */
+        if (ev->poll_msecs >= 0)
+                intv_msecs = ev->poll_msecs;
+        else if (disk->events & ~disk->async_events)
+                intv_msecs = disk_events_dfl_poll_msecs;
+
+        return msecs_to_jiffies(intv_msecs);
+}
+
+static void __disk_block_events(struct gendisk *disk, bool sync)
+{
+        struct disk_events *ev = disk->ev;
+        unsigned long flags;
+        bool cancel;
+
+        spin_lock_irqsave(&ev->lock, flags);
+        cancel = !ev->block++;
+        spin_unlock_irqrestore(&ev->lock, flags);
+
+        if (cancel) {
+                if (sync)
+                        cancel_delayed_work_sync(&disk->ev->dwork);
+                else
+                        cancel_delayed_work(&disk->ev->dwork);
+        }
+}
+
+static void __disk_unblock_events(struct gendisk *disk, bool check_now)
+{
+        struct disk_events *ev = disk->ev;
+        unsigned long intv;
+        unsigned long flags;
+
+        spin_lock_irqsave(&ev->lock, flags);
+
+        if (WARN_ON_ONCE(ev->block <= 0))
+                goto out_unlock;
+
+        if (--ev->block)
+                goto out_unlock;
+
+        /*
+         * Not exactly a latency critical operation, set poll timer
+         * slack to 25% and kick event check.
+         */
+        intv = disk_events_poll_jiffies(disk);
+        set_timer_slack(&ev->dwork.timer, intv / 4);
+        if (check_now)
+                queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
+        else if (intv)
+                queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
+out_unlock:
+        spin_unlock_irqrestore(&ev->lock, flags);
+}
+
+/**
+ * disk_block_events - block and flush disk event checking
+ * @disk: disk to block events for
+ *
+ * On return from this function, it is guaranteed that event checking
+ * isn't in progress and won't happen until unblocked by
+ * disk_unblock_events().  Events blocking is counted and the actual
+ * unblocking happens after the matching number of unblocks are done.
+ *
+ * Note that this intentionally does not block event checking from
+ * disk_clear_events().
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void disk_block_events(struct gendisk *disk)
+{
+        if (disk->ev)
+                __disk_block_events(disk, true);
+}
+
+/**
+ * disk_unblock_events - unblock disk event checking
+ * @disk: disk to unblock events for
+ *
+ * Undo disk_block_events().  When the block count reaches zero, it
+ * starts events polling if configured.
+ *
+ * CONTEXT:
+ * Don't care.  Safe to call from irq context.
+ */
+void disk_unblock_events(struct gendisk *disk)
+{
+        if (disk->ev)
+                __disk_unblock_events(disk, true);
+}
+
+/**
+ * disk_check_events - schedule immediate event checking
+ * @disk: disk to check events for
+ *
+ * Schedule immediate event checking on @disk if not blocked.
+ *
+ * CONTEXT:
+ * Don't care.  Safe to call from irq context.
+ */
+void disk_check_events(struct gendisk *disk)
+{
+        if (disk->ev) {
+                __disk_block_events(disk, false);
+                __disk_unblock_events(disk, true);
+        }
+}
+EXPORT_SYMBOL_GPL(disk_check_events);
+
+/**
+ * disk_clear_events - synchronously check, clear and return pending events
+ * @disk: disk to fetch and clear events from
+ * @mask: mask of events to be fetched and clearted
+ *
+ * Disk events are synchronously checked and pending events in @mask
+ * are cleared and returned.  This ignores the block count.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
+{
+        const struct block_device_operations *bdops = disk->fops;
+        struct disk_events *ev = disk->ev;
+        unsigned int pending;
+
+        if (!ev) {
+                /* for drivers still using the old ->media_changed method */
+                if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
+                    bdops->media_changed && bdops->media_changed(disk))
+                        return DISK_EVENT_MEDIA_CHANGE;
+                return 0;
+        }
+
+        /* tell the workfn about the events being cleared */
+        spin_lock_irq(&ev->lock);
+        ev->clearing |= mask;
+        spin_unlock_irq(&ev->lock);
+
+        /* uncondtionally schedule event check and wait for it to finish */
+        __disk_block_events(disk, true);
+        queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
+        flush_delayed_work(&ev->dwork);
+        __disk_unblock_events(disk, false);
+
+        /* then, fetch and clear pending events */
+        spin_lock_irq(&ev->lock);
+        WARN_ON_ONCE(ev->clearing & mask);      /* cleared by workfn */
+        pending = ev->pending & mask;
+        ev->pending &= ~mask;
+        spin_unlock_irq(&ev->lock);
+
+        return pending;
+}
+
+static void disk_events_workfn(struct work_struct *work)
+{
+        struct delayed_work *dwork = to_delayed_work(work);
+        struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
+        struct gendisk *disk = ev->disk;
+        char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
+        unsigned int clearing = ev->clearing;
+        unsigned int events;
+        unsigned long intv;
+        int nr_events = 0, i;
+
+        /* check events */
+        events = disk->fops->check_events(disk, clearing);
+
+        /* accumulate pending events and schedule next poll if necessary */
+        spin_lock_irq(&ev->lock);
+
+        events &= ~ev->pending;
+        ev->pending |= events;
+        ev->clearing &= ~clearing;
+
+        intv = disk_events_poll_jiffies(disk);
+        if (!ev->block && intv)
+                queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
+
+        spin_unlock_irq(&ev->lock);
+
+        /* tell userland about new events */
+        for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
+                if (events & (1 << i))
+                        envp[nr_events++] = disk_uevents[i];
+
+        if (nr_events)
+                kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
+}
+
+/*
+ * A disk events enabled device has the following sysfs nodes under
+ * its /sys/block/X/ directory.
+ *
+ * events               : list of all supported events
+ * events_async         : list of events which can be detected w/o polling
+ * events_poll_msecs    : polling interval, 0: disable, -1: system default
+ */
+static ssize_t __disk_events_show(unsigned int events, char *buf)
+{
+        const char *delim = "";
+        ssize_t pos = 0;
+        int i;
+
+        for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
+                if (events & (1 << i)) {
+                        pos += sprintf(buf + pos, "%s%s",
+                                       delim, disk_events_strs[i]);
+                        delim = " ";
+                }
+        if (pos)
+                pos += sprintf(buf + pos, "\n");
+        return pos;
+}
+
+static ssize_t disk_events_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        struct gendisk *disk = dev_to_disk(dev);
+
+        return __disk_events_show(disk->events, buf);
+}
+
+static ssize_t disk_events_async_show(struct device *dev,
+                                      struct device_attribute *attr, char *buf)
+{
+        struct gendisk *disk = dev_to_disk(dev);
+
+        return __disk_events_show(disk->async_events, buf);
+}
+
+static ssize_t disk_events_poll_msecs_show(struct device *dev,
+                                           struct device_attribute *attr,
+                                           char *buf)
+{
+        struct gendisk *disk = dev_to_disk(dev);
+
+        return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
+}
+
+static ssize_t disk_events_poll_msecs_store(struct device *dev,
+                                            struct device_attribute *attr,
+                                            const char *buf, size_t count)
+{
+        struct gendisk *disk = dev_to_disk(dev);
+        long intv;
+
+        if (!count || !sscanf(buf, "%ld", &intv))
+                return -EINVAL;
+
+        if (intv < 0 && intv != -1)
+                return -EINVAL;
+
+        __disk_block_events(disk, true);
+        disk->ev->poll_msecs = intv;
+        __disk_unblock_events(disk, true);
+
+        return count;
+}
+
+static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL);
+static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL);
+static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR,
+                         disk_events_poll_msecs_show,
+                         disk_events_poll_msecs_store);
+
+static const struct attribute *disk_events_attrs[] = {
+        &dev_attr_events.attr,
+        &dev_attr_events_async.attr,
+        &dev_attr_events_poll_msecs.attr,
+        NULL,
+};
+
+/*
+ * The default polling interval can be specified by the kernel
+ * parameter block.events_dfl_poll_msecs which defaults to 0
+ * (disable).  This can also be modified runtime by writing to
+ * /sys/module/block/events_dfl_poll_msecs.
+ */
+static int disk_events_set_dfl_poll_msecs(const char *val,
+                                          const struct kernel_param *kp)
+{
+        struct disk_events *ev;
+        int ret;
+
+        ret = param_set_ulong(val, kp);
+        if (ret < 0)
+                return ret;
+
+        mutex_lock(&disk_events_mutex);
+
+        list_for_each_entry(ev, &disk_events, node)
+                disk_check_events(ev->disk);
+
+        mutex_unlock(&disk_events_mutex);
+
+        return 0;
+}
+
+static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
+        .set    = disk_events_set_dfl_poll_msecs,
+        .get    = param_get_ulong,
+};
+
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX     "block."
+
+module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
+                &disk_events_dfl_poll_msecs, 0644);
+
+/*
+ * disk_{add|del|release}_events - initialize and destroy disk_events.
+ */
+static void disk_add_events(struct gendisk *disk)
+{
+        struct disk_events *ev;
+
+        if (!disk->fops->check_events || !(disk->events | disk->async_events))
+                return;
+
+        ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+        if (!ev) {
+                pr_warn("%s: failed to initialize events\n", disk->disk_name);
+                return;
+        }
+
+        if (sysfs_create_files(&disk_to_dev(disk)->kobj,
+                               disk_events_attrs) < 0) {
+                pr_warn("%s: failed to create sysfs files for events\n",
+                        disk->disk_name);
+                kfree(ev);
+                return;
+        }
+
+        disk->ev = ev;
+
+        INIT_LIST_HEAD(&ev->node);
+        ev->disk = disk;
+        spin_lock_init(&ev->lock);
+        ev->block = 1;
+        ev->poll_msecs = -1;
+        INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
+
+        mutex_lock(&disk_events_mutex);
+        list_add_tail(&ev->node, &disk_events);
+        mutex_unlock(&disk_events_mutex);
+
+        /*
+         * Block count is initialized to 1 and the following initial
+         * unblock kicks it into action.
+         */
+        __disk_unblock_events(disk, true);
+}
+
+static void disk_del_events(struct gendisk *disk)
+{
+        if (!disk->ev)
+                return;
+
+        __disk_block_events(disk, true);
+
+        mutex_lock(&disk_events_mutex);
+        list_del_init(&disk->ev->node);
+        mutex_unlock(&disk_events_mutex);
+
+        sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
+}
+
+static void disk_release_events(struct gendisk *disk)
+{
+        /* the block count should be 1 from disk_del_events() */
+        WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
+        kfree(disk->ev);
+}
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index af13c62dc473..1ea8f8d363c6 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -1348,7 +1348,10 @@ static int cdrom_select_disc(struct cdrom_device_info *cdi, int slot)
         if (!CDROM_CAN(CDC_SELECT_DISC))
                 return -EDRIVE_CANT_DO_THIS;
 
-        (void) cdi->ops->media_changed(cdi, slot);
+        if (cdi->ops->check_events)
+                cdi->ops->check_events(cdi, 0, slot);
+        else
+                cdi->ops->media_changed(cdi, slot);
 
         if (slot == CDSL_NONE) {
                 /* set media changed bits, on both queues */
@@ -1392,6 +1395,41 @@ static int cdrom_select_disc(struct cdrom_device_info *cdi, int slot)
         return slot;
 }
 
+/*
+ * As cdrom implements an extra ioctl consumer for media changed
+ * event, it needs to buffer ->check_events() output, such that event
+ * is not lost for both the usual VFS and ioctl paths.
+ * cdi->{vfs|ioctl}_events are used to buffer pending events for each
+ * path.
+ *
+ * XXX: Locking is non-existent.  cdi->ops->check_events() can be
+ * called in parallel and buffering fields are accessed without any
+ * exclusion.  The original media_changed code had the same problem.
+ * It might be better to simply deprecate CDROM_MEDIA_CHANGED ioctl
+ * and remove this cruft altogether.  It doesn't have much usefulness
+ * at this point.
+ */
+static void cdrom_update_events(struct cdrom_device_info *cdi,
+                                unsigned int clearing)
+{
+        unsigned int events;
+
+        events = cdi->ops->check_events(cdi, clearing, CDSL_CURRENT);
+        cdi->vfs_events |= events;
+        cdi->ioctl_events |= events;
+}
+
+unsigned int cdrom_check_events(struct cdrom_device_info *cdi,
+                                unsigned int clearing)
+{
+        unsigned int events;
+
+        cdrom_update_events(cdi, clearing);
+        events = cdi->vfs_events;
+        cdi->vfs_events = 0;
+        return events;
+}
+
 /* We want to make media_changed accessible to the user through an
  * ioctl. The main problem now is that we must double-buffer the
  * low-level implementation, to assure that the VFS and the user both
@@ -1403,15 +1441,26 @@ int media_changed(struct cdrom_device_info *cdi, int queue)
 {
         unsigned int mask = (1 << (queue & 1));
         int ret = !!(cdi->mc_flags & mask);
+        bool changed;
 
         if (!CDROM_CAN(CDC_MEDIA_CHANGED))
-            return ret;
+                return ret;
+
         /* changed since last call? */
-        if (cdi->ops->media_changed(cdi, CDSL_CURRENT)) {
+        if (cdi->ops->check_events) {
+                BUG_ON(!queue); /* shouldn't be called from VFS path */
+                cdrom_update_events(cdi, DISK_EVENT_MEDIA_CHANGE);
+                changed = cdi->ioctl_events & DISK_EVENT_MEDIA_CHANGE;
+                cdi->ioctl_events = 0;
+        } else
+                changed = cdi->ops->media_changed(cdi, CDSL_CURRENT);
+
+        if (changed) {
                 cdi->mc_flags = 0x3;    /* set bit on both queues */
                 ret |= 1;
                 cdi->media_written = 0;
         }
+
         cdi->mc_flags &= ~mask;         /* clear bit */
         return ret;
 }
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index eafeeda6e194..13bf89145b18 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1984,8 +1984,7 @@ EXPORT_SYMBOL(scsi_mode_sense);
  *              in.
  *
  *      Returns zero if unsuccessful or an error if TUR failed.  For
- *      removable media, a return of NOT_READY or UNIT_ATTENTION is
- *      translated to success, with the ->changed flag updated.
+ *      removable media, UNIT_ATTENTION sets ->changed flag.
  **/
 int
 scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
@@ -2012,16 +2011,6 @@ scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
         } while (scsi_sense_valid(sshdr) &&
                  sshdr->sense_key == UNIT_ATTENTION && --retries);
 
-        if (!sshdr)
-                /* could not allocate sense buffer, so can't process it */
-                return result;
-
-        if (sdev->removable && scsi_sense_valid(sshdr) &&
-            (sshdr->sense_key == UNIT_ATTENTION ||
-             sshdr->sense_key == NOT_READY)) {
-                sdev->changed = 1;
-                result = 0;
-        }
         if (!sshdr_external)
                 kfree(sshdr);
         return result;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index b9ab3a590e4b..b179b0e39a3b 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -991,30 +991,50 @@ out:
 
 static void set_media_not_present(struct scsi_disk *sdkp)
 {
+        if (sdkp->media_present)
+                sdkp->device->changed = 1;
         sdkp->media_present = 0;
         sdkp->capacity = 0;
-        sdkp->device->changed = 1;
+}
+
+static int media_not_present(struct scsi_disk *sdkp,
+                             struct scsi_sense_hdr *sshdr)
+{
+        if (!scsi_sense_valid(sshdr))
+                return 0;
+
+        /* not invoked for commands that could return deferred errors */
+        switch (sshdr->sense_key) {
+        case UNIT_ATTENTION:
+                sdkp->device->changed = 1;
+                /* fall through */
+        case NOT_READY:
+                /* medium not present */
+                if (sshdr->asc == 0x3A) {
+                        set_media_not_present(sdkp);
+                        return 1;
+                }
+        }
+        return 0;
 }
 
 /**
- *      sd_media_changed - check if our medium changed
- *      @disk: kernel device descriptor 
+ *      sd_check_events - check media events
+ *      @disk: kernel device descriptor
+ *      @clearing: disk events currently being cleared
  *
- *      Returns 0 if not applicable or no change; 1 if change
+ *      Returns mask of DISK_EVENT_*.
  *
  *      Note: this function is invoked from the block subsystem.
  **/
-static int sd_media_changed(struct gendisk *disk)
+static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
 {
         struct scsi_disk *sdkp = scsi_disk(disk);
         struct scsi_device *sdp = sdkp->device;
         struct scsi_sense_hdr *sshdr = NULL;
         int retval;
 
-        SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
-
-        if (!sdp->removable)
-                return 0;
+        SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_check_events\n"));
 
         /*
          * If the device is offline, don't send any commands - just pretend as
@@ -1024,7 +1044,6 @@ static int sd_media_changed(struct gendisk *disk)
          */
         if (!scsi_device_online(sdp)) {
                 set_media_not_present(sdkp);
-                retval = 1;
                 goto out;
         }
 
@@ -1045,34 +1064,30 @@ static int sd_media_changed(struct gendisk *disk)
                                               sshdr);
         }
 
-        /*
-         * Unable to test, unit probably not ready.   This usually
-         * means there is no disc in the drive.  Mark as changed,
-         * and we will figure it out later once the drive is
-         * available again.
-         */
-        if (retval || (scsi_sense_valid(sshdr) &&
-                       /* 0x3a is medium not present */
-                       sshdr->asc == 0x3a)) {
+        /* failed to execute TUR, assume media not present */
+        if (host_byte(retval)) {
                 set_media_not_present(sdkp);
-                retval = 1;
                 goto out;
         }
 
+        if (media_not_present(sdkp, sshdr))
+                goto out;
+
         /*
          * For removable scsi disk we have to recognise the presence
-         * of a disk in the drive. This is kept in the struct scsi_disk
-         * struct and tested at open !  Daniel Roche (dan@lectra.fr)
+         * of a disk in the drive.
          */
+        if (!sdkp->media_present)
+                sdp->changed = 1;
         sdkp->media_present = 1;
-
-        retval = sdp->changed;
-        sdp->changed = 0;
 out:
-        if (retval != sdkp->previous_state)
+        /* for backward compatibility */
+        if (sdp->changed)
                 sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
-        sdkp->previous_state = retval;
         kfree(sshdr);
+
+        retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0;
+        sdp->changed = 0;
         return retval;
 }
 
@@ -1165,7 +1180,7 @@ static const struct block_device_operations sd_fops = {
 #ifdef CONFIG_COMPAT
         .compat_ioctl           = sd_compat_ioctl,
 #endif
-        .media_changed          = sd_media_changed,
+        .check_events           = sd_check_events,
         .revalidate_disk        = sd_revalidate_disk,
         .unlock_native_capacity = sd_unlock_native_capacity,
 };
@@ -1301,23 +1316,6 @@ static int sd_done(struct scsi_cmnd *SCpnt)
         return good_bytes;
 }
 
-static int media_not_present(struct scsi_disk *sdkp,
-                             struct scsi_sense_hdr *sshdr)
-{
-
-        if (!scsi_sense_valid(sshdr))
-                return 0;
-        /* not invoked for commands that could return deferred errors */
-        if (sshdr->sense_key != NOT_READY &&
-            sshdr->sense_key != UNIT_ATTENTION)
-                return 0;
-        if (sshdr->asc != 0x3A) /* medium not present */
-                return 0;
-
-        set_media_not_present(sdkp);
-        return 1;
-}
-
 /*
  * spinup disk - called only in sd_revalidate_disk()
  */
@@ -1492,7 +1490,7 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
          */
         if (sdp->removable &&
             sense_valid && sshdr->sense_key == NOT_READY)
-                sdp->changed = 1;
+                set_media_not_present(sdkp);
 
         /*
          * We used to set media_present to 0 here to indicate no media
@@ -2347,8 +2345,10 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
 
         gd->driverfs_dev = &sdp->sdev_gendev;
         gd->flags = GENHD_FL_EXT_DEVT;
-        if (sdp->removable)
+        if (sdp->removable) {
                 gd->flags |= GENHD_FL_REMOVABLE;
+                gd->events |= DISK_EVENT_MEDIA_CHANGE;
+        }
 
         add_disk(gd);
         sd_dif_config_host(sdkp);
@@ -2430,7 +2430,6 @@ static int sd_probe(struct device *dev)
         sdkp->disk = gd;
         sdkp->index = index;
         atomic_set(&sdkp->openers, 0);
-        sdkp->previous_state = 1;
 
         if (!sdp->request_queue->rq_timeout) {
                 if (sdp->type != TYPE_MOD)
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 55488faf0815..c9d8f6ca49e2 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -55,7 +55,6 @@ struct scsi_disk {
         u8              media_present;
         u8              write_prot;
         u8              protection_type;/* Data Integrity Field */
-        unsigned        previous_state : 1;
         unsigned        ATO : 1;        /* state of disk ATO bit */
         unsigned        WCE : 1;        /* state of disk WCE bit */
         unsigned        RCD : 1;        /* state of disk RCD bit, unused */
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index d7b383c96d5d..be6baf8ad704 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -104,14 +104,15 @@ static void sr_release(struct cdrom_device_info *);
 static void get_sectorsize(struct scsi_cd *);
 static void get_capabilities(struct scsi_cd *);
 
-static int sr_media_change(struct cdrom_device_info *, int);
+static unsigned int sr_check_events(struct cdrom_device_info *cdi,
+                                    unsigned int clearing, int slot);
 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
 
 static struct cdrom_device_ops sr_dops = {
         .open                   = sr_open,
         .release                = sr_release,
         .drive_status           = sr_drive_status,
-        .media_changed          = sr_media_change,
+        .check_events           = sr_check_events,
         .tray_move              = sr_tray_move,
         .lock_door              = sr_lock_door,
         .select_speed           = sr_select_speed,
@@ -165,90 +166,96 @@ static void scsi_cd_put(struct scsi_cd *cd)
         mutex_unlock(&sr_ref_mutex);
 }
 
-/* identical to scsi_test_unit_ready except that it doesn't
- * eat the NOT_READY returns for removable media */
-int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr)
+static unsigned int sr_get_events(struct scsi_device *sdev)
 {
-        int retries = MAX_RETRIES;
-        int the_result;
-        u8 cmd[] = {TEST_UNIT_READY, 0, 0, 0, 0, 0 };
+        u8 buf[8];
+        u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
+                     1,                 /* polled */
+                     0, 0,              /* reserved */
+                     1 << 4,            /* notification class: media */
+                     0, 0,              /* reserved */
+                     0, sizeof(buf),    /* allocation length */
+                     0,                 /* control */
+        };
+        struct event_header *eh = (void *)buf;
+        struct media_event_desc *med = (void *)(buf + 4);
+        struct scsi_sense_hdr sshdr;
+        int result;
 
-        /* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
-         * conditions are gone, or a timeout happens
-         */
-        do {
-                the_result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL,
-                                              0, sshdr, SR_TIMEOUT,
-                                              retries--, NULL);
-                if (scsi_sense_valid(sshdr) &&
-                    sshdr->sense_key == UNIT_ATTENTION)
-                        sdev->changed = 1;
-
-        } while (retries > 0 &&
-                 (!scsi_status_is_good(the_result) ||
-                  (scsi_sense_valid(sshdr) &&
-                   sshdr->sense_key == UNIT_ATTENTION)));
-        return the_result;
+        result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
+                                  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
+        if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
+                return DISK_EVENT_MEDIA_CHANGE;
+
+        if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
+                return 0;
+
+        if (eh->nea || eh->notification_class != 0x4)
+                return 0;
+
+        if (med->media_event_code == 1)
+                return DISK_EVENT_EJECT_REQUEST;
+        else if (med->media_event_code == 2)
+                return DISK_EVENT_MEDIA_CHANGE;
+        return 0;
 }
 
 /*
- * This function checks to see if the media has been changed in the
- * CDROM drive.  It is possible that we have already sensed a change,
- * or the drive may have sensed one and not yet reported it.  We must
- * be ready for either case. This function always reports the current
- * value of the changed bit.  If flag is 0, then the changed bit is reset.
- * This function could be done as an ioctl, but we would need to have
- * an inode for that to work, and we do not always have one.
+ * This function checks to see if the media has been changed or eject
+ * button has been pressed.  It is possible that we have already
+ * sensed a change, or the drive may have sensed one and not yet
+ * reported it.  The past events are accumulated in sdev->changed and
+ * returned together with the current state.
  */
-
-static int sr_media_change(struct cdrom_device_info *cdi, int slot)
+static unsigned int sr_check_events(struct cdrom_device_info *cdi,
+                                    unsigned int clearing, int slot)
 {
         struct scsi_cd *cd = cdi->handle;
-        int retval;
-        struct scsi_sense_hdr *sshdr;
+        bool last_present;
+        struct scsi_sense_hdr sshdr;
+        unsigned int events;
+        int ret;
 
-        if (CDSL_CURRENT != slot) {
-                /* no changer support */
-                return -EINVAL;
-        }
+        /* no changer support */
+        if (CDSL_CURRENT != slot)
+                return 0;
 
-        sshdr =  kzalloc(sizeof(*sshdr), GFP_KERNEL);
-        retval = sr_test_unit_ready(cd->device, sshdr);
-        if (retval || (scsi_sense_valid(sshdr) &&
-                       /* 0x3a is medium not present */
-                       sshdr->asc == 0x3a)) {
-                /* Media not present or unable to test, unit probably not
-                 * ready. This usually means there is no disc in the drive.
-                 * Mark as changed, and we will figure it out later once
-                 * the drive is available again.
-                 */
-                cd->device->changed = 1;
-                /* This will force a flush, if called from check_disk_change */
-                retval = 1;
-                goto out;
-        };
+        events = sr_get_events(cd->device);
+        /*
+         * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
+         * is being cleared.  Note that there are devices which hang
+         * if asked to execute TUR repeatedly.
+         */
+        if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
+                goto skip_tur;
+
+        /* let's see whether the media is there with TUR */
+        last_present = cd->media_present;
+        ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
+
+        /*
+         * Media is considered to be present if TUR succeeds or fails with
+         * sense data indicating something other than media-not-present
+         * (ASC 0x3a).
+         */
+        cd->media_present = scsi_status_is_good(ret) ||
+                (scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
 
-        retval = cd->device->changed;
-        cd->device->changed = 0;
-        /* If the disk changed, the capacity will now be different,
-         * so we force a re-read of this information */
-        if (retval) {
-                /* check multisession offset etc */
-                sr_cd_check(cdi);
-                get_sectorsize(cd);
+        if (last_present != cd->media_present)
+                events |= DISK_EVENT_MEDIA_CHANGE;
+skip_tur:
+        if (cd->device->changed) {
+                events |= DISK_EVENT_MEDIA_CHANGE;
+                cd->device->changed = 0;
         }
 
-out:
-        /* Notify userspace, that media has changed. */
-        if (retval != cd->previous_state)
+        /* for backward compatibility */
+        if (events & DISK_EVENT_MEDIA_CHANGE)
                 sdev_evt_send_simple(cd->device, SDEV_EVT_MEDIA_CHANGE,
                                      GFP_KERNEL);
-        cd->previous_state = retval;
-        kfree(sshdr);
-
-        return retval;
+        return events;
 }
- 
+
 /*
  * sr_done is the interrupt routine for the device driver.
  *
@@ -533,10 +540,25 @@ out:
         return ret;
 }
 
-static int sr_block_media_changed(struct gendisk *disk)
+static unsigned int sr_block_check_events(struct gendisk *disk,
+                                          unsigned int clearing)
 {
         struct scsi_cd *cd = scsi_cd(disk);
-        return cdrom_media_changed(&cd->cdi);
+        return cdrom_check_events(&cd->cdi, clearing);
+}
+
+static int sr_block_revalidate_disk(struct gendisk *disk)
+{
+        struct scsi_cd *cd = scsi_cd(disk);
+        struct scsi_sense_hdr sshdr;
+
+        /* if the unit is not ready, nothing more to do */
+        if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
+                return 0;
+
+        sr_cd_check(&cd->cdi);
+        get_sectorsize(cd);
+        return 0;
 }
 
 static const struct block_device_operations sr_bdops =
@@ -545,7 +567,8 @@ static const struct block_device_operations sr_bdops =
         .open           = sr_block_open,
         .release        = sr_block_release,
         .ioctl          = sr_block_ioctl,
-        .media_changed  = sr_block_media_changed,
+        .check_events   = sr_block_check_events,
+        .revalidate_disk = sr_block_revalidate_disk,
         /* 
          * No compat_ioctl for now because sr_block_ioctl never
          * seems to pass arbitary ioctls down to host drivers.
@@ -618,6 +641,7 @@ static int sr_probe(struct device *dev)
         sprintf(disk->disk_name, "sr%d", minor);
         disk->fops = &sr_bdops;
         disk->flags = GENHD_FL_CD;
+        disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 
         blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
 
@@ -627,7 +651,7 @@ static int sr_probe(struct device *dev)
         cd->disk = disk;
         cd->capacity = 0x1fffff;
         cd->device->changed = 1;        /* force recheck CD type */
-        cd->previous_state = 1;
+        cd->media_present = 1;
         cd->use = 1;
         cd->readcd_known = 0;
         cd->readcd_cdda = 0;
@@ -780,7 +804,7 @@ static void get_capabilities(struct scsi_cd *cd)
         }
 
         /* eat unit attentions */
-        sr_test_unit_ready(cd->device, &sshdr);
+        scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 
         /* ask for mode page 0x2a */
         rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
diff --git a/drivers/scsi/sr.h b/drivers/scsi/sr.h
index 1e144dfdbd4b..e036f1dc83c8 100644
--- a/drivers/scsi/sr.h
+++ b/drivers/scsi/sr.h
@@ -40,7 +40,7 @@ typedef struct scsi_cd {
         unsigned xa_flag:1;     /* CD has XA sectors ? */
         unsigned readcd_known:1;        /* drive supports READ_CD (0xbe) */
         unsigned readcd_cdda:1; /* reading audio data using READ_CD */
-        unsigned previous_state:1;      /* media has changed */
+        unsigned media_present:1;       /* media is present */
         struct cdrom_device_info cdi;
         /* We hold gendisk and scsi_device references on probe and use
          * the refs on this kref to decide when to release them */
@@ -61,7 +61,6 @@ int sr_select_speed(struct cdrom_device_info *cdi, int speed);
 int sr_audio_ioctl(struct cdrom_device_info *, unsigned int, void *);
 
 int sr_is_xa(Scsi_CD *);
-int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr);
 
 /* sr_vendor.c */
 void sr_vendor_init(Scsi_CD *);
diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c
index 3cd8ffbad577..8be30554119b 100644
--- a/drivers/scsi/sr_ioctl.c
+++ b/drivers/scsi/sr_ioctl.c
@@ -307,7 +307,7 @@ int sr_drive_status(struct cdrom_device_info *cdi, int slot)
                 /* we have no changer support */
                 return -EINVAL;
         }
-        if (0 == sr_test_unit_ready(cd->device, &sshdr))
+        if (!scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
                 return CDS_DISC_OK;
 
         /* SK/ASC/ASCQ of 2/4/1 means "unit is becoming ready" */
diff --git a/fs/block_dev.c b/fs/block_dev.c
index c1c1b8c3fb99..6017389711ee 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -948,10 +948,11 @@ int check_disk_change(struct block_device *bdev)
 {
         struct gendisk *disk = bdev->bd_disk;
         const struct block_device_operations *bdops = disk->fops;
+        unsigned int events;
 
-        if (!bdops->media_changed)
-                return 0;
-        if (!bdops->media_changed(bdev->bd_disk))
+        events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE |
+                                   DISK_EVENT_EJECT_REQUEST);
+        if (!(events & DISK_EVENT_MEDIA_CHANGE))
                 return 0;
 
         flush_disk(bdev);
@@ -1158,9 +1159,10 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
 
         if (whole) {
                 /* finish claiming */
+                mutex_lock(&bdev->bd_mutex);
                 spin_lock(&bdev_lock);
 
-                if (res == 0) {
+                if (!res) {
                         BUG_ON(!bd_may_claim(bdev, whole, holder));
                         /*
                          * Note that for a whole device bd_holders
@@ -1180,6 +1182,20 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
                 wake_up_bit(&whole->bd_claiming, 0);
 
                 spin_unlock(&bdev_lock);
+
+                /*
+                 * Block event polling for write claims.  Any write
+                 * holder makes the write_holder state stick until all
+                 * are released.  This is good enough and tracking
+                 * individual writeable reference is too fragile given
+                 * the way @mode is used in blkdev_get/put().
+                 */
+                if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
+                        bdev->bd_write_holder = true;
+                        disk_block_events(bdev->bd_disk);
+                }
+
+                mutex_unlock(&bdev->bd_mutex);
                 bdput(whole);
         }
 
@@ -1353,12 +1369,23 @@ int blkdev_put(struct block_device *bdev, fmode_t mode)
 
                 spin_unlock(&bdev_lock);
 
-                /* if this was the last claim, holder link should go too */
-                if (bdev_free)
+                /*
+                 * If this was the last claim, remove holder link and
+                 * unblock evpoll if it was a write holder.
+                 */
+                if (bdev_free) {
                         bd_unlink_disk_holder(bdev);
+                        if (bdev->bd_write_holder) {
+                                disk_unblock_events(bdev->bd_disk);
+                                bdev->bd_write_holder = false;
+                        } else
+                                disk_check_events(bdev->bd_disk);
+                }
 
                 mutex_unlock(&bdev->bd_mutex);
-        }
+        } else
+                disk_check_events(bdev->bd_disk);
+
         return __blkdev_put(bdev, mode, 0);
 }
 EXPORT_SYMBOL(blkdev_put);
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index bdf8d3cc95a4..9a48d65d9855 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -516,65 +516,6 @@ out_put:
         return ERR_PTR(err);
 }
 
-/* Not exported, helper to add_disk(). */
-void register_disk(struct gendisk *disk)
-{
-        struct device *ddev = disk_to_dev(disk);
-        struct block_device *bdev;
-        struct disk_part_iter piter;
-        struct hd_struct *part;
-        int err;
-
-        ddev->parent = disk->driverfs_dev;
-
-        dev_set_name(ddev, disk->disk_name);
-
-        /* delay uevents, until we scanned partition table */
-        dev_set_uevent_suppress(ddev, 1);
-
-        if (device_add(ddev))
-                return;
-        if (!sysfs_deprecated) {
-                err = sysfs_create_link(block_depr, &ddev->kobj,
-                                        kobject_name(&ddev->kobj));
-                if (err) {
-                        device_del(ddev);
-                        return;
-                }
-        }
-        disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
-        disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
-
-        /* No minors to use for partitions */
-        if (!disk_partitionable(disk))
-                goto exit;
-
-        /* No such device (e.g., media were just removed) */
-        if (!get_capacity(disk))
-                goto exit;
-
-        bdev = bdget_disk(disk, 0);
-        if (!bdev)
-                goto exit;
-
-        bdev->bd_invalidated = 1;
-        err = blkdev_get(bdev, FMODE_READ, NULL);
-        if (err < 0)
-                goto exit;
-        blkdev_put(bdev, FMODE_READ);
-
-exit:
-        /* announce disk after possible partitions are created */
-        dev_set_uevent_suppress(ddev, 0);
-        kobject_uevent(&ddev->kobj, KOBJ_ADD);
-
-        /* announce possible partitions */
-        disk_part_iter_init(&piter, disk, 0);
-        while ((part = disk_part_iter_next(&piter)))
-                kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
-        disk_part_iter_exit(&piter);
-}
-
 static bool disk_unlock_native_capacity(struct gendisk *disk)
 {
         const struct block_device_operations *bdops = disk->fops;
@@ -737,33 +678,3 @@ fail:
 }
 
 EXPORT_SYMBOL(read_dev_sector);
-
-void del_gendisk(struct gendisk *disk)
-{
-        struct disk_part_iter piter;
-        struct hd_struct *part;
-
-        /* invalidate stuff */
-        disk_part_iter_init(&piter, disk,
-                             DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
-        while ((part = disk_part_iter_next(&piter))) {
-                invalidate_partition(disk, part->partno);
-                delete_partition(disk, part->partno);
-        }
-        disk_part_iter_exit(&piter);
-
-        invalidate_partition(disk, 0);
-        blk_free_devt(disk_to_dev(disk)->devt);
-        set_capacity(disk, 0);
-        disk->flags &= ~GENHD_FL_UP;
-        unlink_gendisk(disk);
-        part_stat_set_all(&disk->part0, 0);
-        disk->part0.stamp = 0;
-
-        kobject_put(disk->part0.holder_dir);
-        kobject_put(disk->slave_dir);
-        disk->driverfs_dev = NULL;
-        if (!sysfs_deprecated)
-                sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
-        device_del(disk_to_dev(disk));
-}
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index aae86fd10c4f..05667e6989f1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -643,7 +643,6 @@ static inline void rq_flush_dcache_pages(struct request *rq)
 
 extern int blk_register_queue(struct gendisk *disk);
 extern void blk_unregister_queue(struct gendisk *disk);
-extern void register_disk(struct gendisk *dev);
 extern void generic_make_request(struct bio *bio);
 extern void blk_rq_init(struct request_queue *q, struct request *rq);
 extern void blk_put_request(struct request *);
@@ -1252,6 +1251,9 @@ struct block_device_operations {
         int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
         int (*direct_access) (struct block_device *, sector_t,
                                                 void **, unsigned long *);
+        unsigned int (*check_events) (struct gendisk *disk,
+                                      unsigned int clearing);
+        /* ->media_changed() is DEPRECATED, use ->check_events() instead */
         int (*media_changed) (struct gendisk *);
         void (*unlock_native_capacity) (struct gendisk *);
         int (*revalidate_disk) (struct gendisk *);
diff --git a/include/linux/cdrom.h b/include/linux/cdrom.h
index 78e904796622..35eae4b67503 100644
--- a/include/linux/cdrom.h
+++ b/include/linux/cdrom.h
@@ -946,6 +946,8 @@ struct cdrom_device_info {
 /* device-related storage */
         unsigned int options    : 30;   /* options flags */
         unsigned mc_flags       : 2;    /* media change buffer flags */
+        unsigned int vfs_events;        /* cached events for vfs path */
+        unsigned int ioctl_events;      /* cached events for ioctl path */
         int use_count;                  /* number of times device opened */
         char name[20];                  /* name of the device type */
 /* per-device flags */
@@ -965,6 +967,8 @@ struct cdrom_device_ops {
         int (*open) (struct cdrom_device_info *, int);
         void (*release) (struct cdrom_device_info *);
         int (*drive_status) (struct cdrom_device_info *, int);
+        unsigned int (*check_events) (struct cdrom_device_info *cdi,
+                                      unsigned int clearing, int slot);
         int (*media_changed) (struct cdrom_device_info *, int);
         int (*tray_move) (struct cdrom_device_info *, int);
         int (*lock_door) (struct cdrom_device_info *, int);
@@ -993,6 +997,8 @@ extern int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev,
 extern void cdrom_release(struct cdrom_device_info *cdi, fmode_t mode);
 extern int cdrom_ioctl(struct cdrom_device_info *cdi, struct block_device *bdev,
                        fmode_t mode, unsigned int cmd, unsigned long arg);
+extern unsigned int cdrom_check_events(struct cdrom_device_info *cdi,
+                                       unsigned int clearing);
 extern int cdrom_media_changed(struct cdrom_device_info *);
 
 extern int register_cdrom(struct cdrom_device_info *cdi);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f48501563917..997d22efdef0 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -662,6 +662,7 @@ struct block_device {
         void *                  bd_claiming;
         void *                  bd_holder;
         int                     bd_holders;
+        bool                    bd_write_holder;
 #ifdef CONFIG_SYSFS
         struct gendisk *        bd_holder_disk; /* for sysfs slave linkng */
 #endif
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 7a7b9c1644e4..13893aa2ac9d 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -127,6 +127,11 @@ struct hd_struct {
 #define GENHD_FL_EXT_DEVT                       64 /* allow extended devt */
 #define GENHD_FL_NATIVE_CAPACITY                128
 
+enum {
+        DISK_EVENT_MEDIA_CHANGE                 = 1 << 0, /* media changed */
+        DISK_EVENT_EJECT_REQUEST                = 1 << 1, /* eject requested */
+};
+
 #define BLK_SCSI_MAX_CMDS       (256)
 #define BLK_SCSI_CMD_PER_LONG   (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
 
@@ -143,6 +148,8 @@ struct disk_part_tbl {
         struct hd_struct __rcu *part[];
 };
 
+struct disk_events;
+
 struct gendisk {
         /* major, first_minor and minors are input parameters only,
          * don't use directly.  Use disk_devt() and disk_max_parts().
@@ -154,6 +161,10 @@ struct gendisk {
 
         char disk_name[DISK_NAME_LEN];  /* name of major driver */
         char *(*devnode)(struct gendisk *gd, mode_t *mode);
+
+        unsigned int events;            /* supported events */
+        unsigned int async_events;      /* async events, subset of all */
+
         /* Array of pointers to partitions indexed by partno.
          * Protected with matching bdev lock but stat and other
          * non-critical accesses use RCU.  Always access through
@@ -171,9 +182,8 @@ struct gendisk {
         struct kobject *slave_dir;
 
         struct timer_rand_state *random;
-
         atomic_t sync_io;               /* RAID */
-        struct work_struct async_notify;
+        struct disk_events *ev;
 #ifdef  CONFIG_BLK_DEV_INTEGRITY
         struct blk_integrity *integrity;
 #endif
@@ -395,7 +405,6 @@ extern void part_round_stats(int cpu, struct hd_struct *part);
 /* block/genhd.c */
 extern void add_disk(struct gendisk *disk);
 extern void del_gendisk(struct gendisk *gp);
-extern void unlink_gendisk(struct gendisk *gp);
 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 
@@ -407,6 +416,11 @@ static inline int get_disk_ro(struct gendisk *disk)
         return disk->part0.policy;
 }
 
+extern void disk_block_events(struct gendisk *disk);
+extern void disk_unblock_events(struct gendisk *disk);
+extern void disk_check_events(struct gendisk *disk);
+extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
+
 /* drivers/char/random.c */
 extern void add_disk_randomness(struct gendisk *disk);
 extern void rand_initialize_disk(struct gendisk *disk);
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 216af8538cc9..86758618d4f8 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -104,6 +104,7 @@ struct scsi_cmnd;
 #define UNMAP                 0x42
 #define READ_TOC              0x43
 #define READ_HEADER           0x44
+#define GET_EVENT_STATUS_NOTIFICATION 0x4a
 #define LOG_SELECT            0x4c
 #define LOG_SENSE             0x4d
 #define XDWRITEREAD_10        0x53