Move the code for handling disk events from genhd.c into a new file
as it isn't very related to the rest of the file while at the same
time requiring lots of forward declarations.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/Makefile | 3 +-
block/blk.h | 5 +
block/disk-events.c | 484 +++++++++++++++++++++++++++++++++++++++++++
block/genhd.c | 492 --------------------------------------------
4 files changed, 491 insertions(+), 493 deletions(-)
create mode 100644 block/disk-events.c
diff --git a/block/Makefile b/block/Makefile
index b9db5d4edfc8..bfbe4e13ca1e 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -8,7 +8,8 @@ obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-sysfs.o \
blk-exec.o blk-merge.o blk-timeout.o \
blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
blk-mq-sysfs.o blk-mq-cpumap.o blk-mq-sched.o ioctl.o \
- genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o
+ genhd.o ioprio.o badblocks.o partitions/ blk-rq-qos.o \
+ disk-events.o
obj-$(CONFIG_BOUNCE) += bounce.o
obj-$(CONFIG_BLK_SCSI_REQUEST) += scsi_ioctl.o
diff --git a/block/blk.h b/block/blk.h
index d3fa47af3607..f8d726429906 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -360,4 +360,9 @@ int bio_add_hw_page(struct request_queue *q, struct bio *bio,
struct request_queue *blk_alloc_queue(int node_id);
+void disk_alloc_events(struct gendisk *disk);
+void disk_add_events(struct gendisk *disk);
+void disk_del_events(struct gendisk *disk);
+void disk_release_events(struct gendisk *disk);
+
#endif /* BLK_INTERNAL_H */
diff --git a/block/disk-events.c b/block/disk-events.c
new file mode 100644
index 000000000000..1bc5dcb75e4e
--- /dev/null
+++ b/block/disk-events.c
@@ -0,0 +1,484 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Disk events - monitor disk events like media change and eject request.
+ */
+#include <linux/export.h>
+#include <linux/moduleparam.h>
+#include <linux/genhd.h>
+#include "blk.h"
+
+struct disk_events {
+ struct list_head node; /* all disk_event's */
+ struct gendisk *disk; /* the associated disk */
+ spinlock_t lock;
+
+ struct mutex block_mutex; /* protects blocking */
+ 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;
+
+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 if the POLL flag is set.
+ */
+ if (ev->poll_msecs >= 0)
+ intv_msecs = ev->poll_msecs;
+ else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
+ intv_msecs = disk_events_dfl_poll_msecs;
+
+ return msecs_to_jiffies(intv_msecs);
+}
+
+/**
+ * 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)
+{
+ struct disk_events *ev = disk->ev;
+ unsigned long flags;
+ bool cancel;
+
+ if (!ev)
+ return;
+
+ /*
+ * Outer mutex ensures that the first blocker completes canceling
+ * the event work before further blockers are allowed to finish.
+ */
+ mutex_lock(&ev->block_mutex);
+
+ spin_lock_irqsave(&ev->lock, flags);
+ cancel = !ev->block++;
+ spin_unlock_irqrestore(&ev->lock, flags);
+
+ if (cancel)
+ cancel_delayed_work_sync(&disk->ev->dwork);
+
+ mutex_unlock(&ev->block_mutex);
+}
+
+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;
+
+ intv = disk_events_poll_jiffies(disk);
+ if (check_now)
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, 0);
+ else if (intv)
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, intv);
+out_unlock:
+ spin_unlock_irqrestore(&ev->lock, flags);
+}
+
+/**
+ * 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, false);
+}
+
+/**
+ * disk_flush_events - schedule immediate event checking and flushing
+ * @disk: disk to check and flush events for
+ * @mask: events to flush
+ *
+ * Schedule immediate event checking on @disk if not blocked. Events in
+ * @mask are scheduled to be cleared from the driver. Note that this
+ * doesn't clear the events from @disk->ev.
+ *
+ * CONTEXT:
+ * If @mask is non-zero must be called with disk->open_mutex held.
+ */
+void disk_flush_events(struct gendisk *disk, unsigned int mask)
+{
+ struct disk_events *ev = disk->ev;
+
+ if (!ev)
+ return;
+
+ spin_lock_irq(&ev->lock);
+ ev->clearing |= mask;
+ if (!ev->block)
+ mod_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, 0);
+ spin_unlock_irq(&ev->lock);
+}
+
+static void disk_check_events(struct disk_events *ev,
+ unsigned int *clearing_ptr)
+{
+ struct gendisk *disk = ev->disk;
+ char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
+ unsigned int clearing = *clearing_ptr;
+ 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;
+ *clearing_ptr &= ~clearing;
+
+ intv = disk_events_poll_jiffies(disk);
+ if (!ev->block && intv)
+ queue_delayed_work(system_freezable_power_efficient_wq,
+ &ev->dwork, intv);
+
+ spin_unlock_irq(&ev->lock);
+
+ /*
+ * Tell userland about new events. Only the events listed in
+ * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
+ * is set. Otherwise, events are processed internally but never
+ * get reported to userland.
+ */
+ for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
+ if ((events & disk->events & (1 << i)) &&
+ (disk->event_flags & DISK_EVENT_FLAG_UEVENT))
+ envp[nr_events++] = disk_uevents[i];
+
+ if (nr_events)
+ kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
+}
+
+/**
+ * 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 cleared
+ *
+ * Disk events are synchronously checked and pending events in @mask
+ * are cleared and returned. This ignores the block count.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
+{
+ struct disk_events *ev = disk->ev;
+ unsigned int pending;
+ unsigned int clearing = mask;
+
+ if (!ev)
+ return 0;
+
+ disk_block_events(disk);
+
+ /*
+ * store the union of mask and ev->clearing on the stack so that the
+ * race with disk_flush_events does not cause ambiguity (ev->clearing
+ * can still be modified even if events are blocked).
+ */
+ spin_lock_irq(&ev->lock);
+ clearing |= ev->clearing;
+ ev->clearing = 0;
+ spin_unlock_irq(&ev->lock);
+
+ disk_check_events(ev, &clearing);
+ /*
+ * if ev->clearing is not 0, the disk_flush_events got called in the
+ * middle of this function, so we want to run the workfn without delay.
+ */
+ __disk_unblock_events(disk, ev->clearing ? true : false);
+
+ /* then, fetch and clear pending events */
+ spin_lock_irq(&ev->lock);
+ pending = ev->pending & mask;
+ ev->pending &= ~mask;
+ spin_unlock_irq(&ev->lock);
+ WARN_ON_ONCE(clearing & mask);
+
+ return pending;
+}
+
+/**
+ * bdev_check_media_change - check if a removable media has been changed
+ * @bdev: block device to check
+ *
+ * Check whether a removable media has been changed, and attempt to free all
+ * dentries and inodes and invalidates all block device page cache entries in
+ * that case.
+ *
+ * Returns %true if the block device changed, or %false if not.
+ */
+bool bdev_check_media_change(struct block_device *bdev)
+{
+ unsigned int events;
+
+ events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE |
+ DISK_EVENT_EJECT_REQUEST);
+ if (!(events & DISK_EVENT_MEDIA_CHANGE))
+ return false;
+
+ if (__invalidate_device(bdev, true))
+ pr_warn("VFS: busy inodes on changed media %s\n",
+ bdev->bd_disk->disk_name);
+ set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
+ return true;
+}
+EXPORT_SYMBOL(bdev_check_media_change);
+
+/*
+ * Separate this part out so that a different pointer for clearing_ptr can be
+ * passed in for disk_clear_events.
+ */
+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);
+
+ disk_check_events(ev, &ev->clearing);
+}
+
+/*
+ * 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
+ * (always empty, only for backwards compatibility)
+ * 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);
+
+ if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
+ return 0;
+ return __disk_events_show(disk->events, buf);
+}
+
+static ssize_t disk_events_async_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return 0;
+}
+
+static ssize_t disk_events_poll_msecs_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct gendisk *disk = dev_to_disk(dev);
+
+ if (!disk->ev)
+ return sprintf(buf, "-1\n");
+ 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;
+
+ if (!disk->ev)
+ return -ENODEV;
+
+ disk_block_events(disk);
+ disk->ev->poll_msecs = intv;
+ __disk_unblock_events(disk, true);
+ return count;
+}
+
+static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
+static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
+static const DEVICE_ATTR(events_poll_msecs, 0644,
+ 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/parameters/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_flush_events(ev->disk, 0);
+ 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_{alloc|add|del|release}_events - initialize and destroy disk_events.
+ */
+void disk_alloc_events(struct gendisk *disk)
+{
+ struct disk_events *ev;
+
+ if (!disk->fops->check_events || !disk->events)
+ return;
+
+ ev = kzalloc(sizeof(*ev), GFP_KERNEL);
+ if (!ev) {
+ pr_warn("%s: failed to initialize events\n", disk->disk_name);
+ return;
+ }
+
+ INIT_LIST_HEAD(&ev->node);
+ ev->disk = disk;
+ spin_lock_init(&ev->lock);
+ mutex_init(&ev->block_mutex);
+ ev->block = 1;
+ ev->poll_msecs = -1;
+ INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
+
+ disk->ev = ev;
+}
+
+void disk_add_events(struct gendisk *disk)
+{
+ /* FIXME: error handling */
+ 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);
+
+ if (!disk->ev)
+ return;
+
+ mutex_lock(&disk_events_mutex);
+ list_add_tail(&disk->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);
+}
+
+void disk_del_events(struct gendisk *disk)
+{
+ if (disk->ev) {
+ disk_block_events(disk);
+
+ 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);
+}
+
+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/block/genhd.c b/block/genhd.c
index 5f5628216295..4f879deede9a 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -33,13 +33,6 @@ static struct kobject *block_depr;
#define NR_EXT_DEVT (1 << MINORBITS)
static DEFINE_IDA(ext_devt_ida);
-static void disk_check_events(struct disk_events *ev,
- unsigned int *clearing_ptr);
-static void disk_alloc_events(struct gendisk *disk);
-static void disk_add_events(struct gendisk *disk);
-static void disk_del_events(struct gendisk *disk);
-static void disk_release_events(struct gendisk *disk);
-
void set_capacity(struct gendisk *disk, sector_t sectors)
{
struct block_device *bdev = disk->part0;
@@ -1367,488 +1360,3 @@ int bdev_read_only(struct block_device *bdev)
return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
}
EXPORT_SYMBOL(bdev_read_only);
-
-/*
- * 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;
-
- struct mutex block_mutex; /* protects blocking */
- 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;
-
-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 if the POLL flag is set.
- */
- if (ev->poll_msecs >= 0)
- intv_msecs = ev->poll_msecs;
- else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
- intv_msecs = disk_events_dfl_poll_msecs;
-
- return msecs_to_jiffies(intv_msecs);
-}
-
-/**
- * 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)
-{
- struct disk_events *ev = disk->ev;
- unsigned long flags;
- bool cancel;
-
- if (!ev)
- return;
-
- /*
- * Outer mutex ensures that the first blocker completes canceling
- * the event work before further blockers are allowed to finish.
- */
- mutex_lock(&ev->block_mutex);
-
- spin_lock_irqsave(&ev->lock, flags);
- cancel = !ev->block++;
- spin_unlock_irqrestore(&ev->lock, flags);
-
- if (cancel)
- cancel_delayed_work_sync(&disk->ev->dwork);
-
- mutex_unlock(&ev->block_mutex);
-}
-
-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;
-
- intv = disk_events_poll_jiffies(disk);
- if (check_now)
- queue_delayed_work(system_freezable_power_efficient_wq,
- &ev->dwork, 0);
- else if (intv)
- queue_delayed_work(system_freezable_power_efficient_wq,
- &ev->dwork, intv);
-out_unlock:
- spin_unlock_irqrestore(&ev->lock, flags);
-}
-
-/**
- * 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, false);
-}
-
-/**
- * disk_flush_events - schedule immediate event checking and flushing
- * @disk: disk to check and flush events for
- * @mask: events to flush
- *
- * Schedule immediate event checking on @disk if not blocked. Events in
- * @mask are scheduled to be cleared from the driver. Note that this
- * doesn't clear the events from @disk->ev.
- *
- * CONTEXT:
- * If @mask is non-zero must be called with disk->open_mutex held.
- */
-void disk_flush_events(struct gendisk *disk, unsigned int mask)
-{
- struct disk_events *ev = disk->ev;
-
- if (!ev)
- return;
-
- spin_lock_irq(&ev->lock);
- ev->clearing |= mask;
- if (!ev->block)
- mod_delayed_work(system_freezable_power_efficient_wq,
- &ev->dwork, 0);
- spin_unlock_irq(&ev->lock);
-}
-
-/**
- * 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 cleared
- *
- * Disk events are synchronously checked and pending events in @mask
- * are cleared and returned. This ignores the block count.
- *
- * CONTEXT:
- * Might sleep.
- */
-static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
-{
- struct disk_events *ev = disk->ev;
- unsigned int pending;
- unsigned int clearing = mask;
-
- if (!ev)
- return 0;
-
- disk_block_events(disk);
-
- /*
- * store the union of mask and ev->clearing on the stack so that the
- * race with disk_flush_events does not cause ambiguity (ev->clearing
- * can still be modified even if events are blocked).
- */
- spin_lock_irq(&ev->lock);
- clearing |= ev->clearing;
- ev->clearing = 0;
- spin_unlock_irq(&ev->lock);
-
- disk_check_events(ev, &clearing);
- /*
- * if ev->clearing is not 0, the disk_flush_events got called in the
- * middle of this function, so we want to run the workfn without delay.
- */
- __disk_unblock_events(disk, ev->clearing ? true : false);
-
- /* then, fetch and clear pending events */
- spin_lock_irq(&ev->lock);
- pending = ev->pending & mask;
- ev->pending &= ~mask;
- spin_unlock_irq(&ev->lock);
- WARN_ON_ONCE(clearing & mask);
-
- return pending;
-}
-
-/**
- * bdev_check_media_change - check if a removable media has been changed
- * @bdev: block device to check
- *
- * Check whether a removable media has been changed, and attempt to free all
- * dentries and inodes and invalidates all block device page cache entries in
- * that case.
- *
- * Returns %true if the block device changed, or %false if not.
- */
-bool bdev_check_media_change(struct block_device *bdev)
-{
- unsigned int events;
-
- events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE |
- DISK_EVENT_EJECT_REQUEST);
- if (!(events & DISK_EVENT_MEDIA_CHANGE))
- return false;
-
- if (__invalidate_device(bdev, true))
- pr_warn("VFS: busy inodes on changed media %s\n",
- bdev->bd_disk->disk_name);
- set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
- return true;
-}
-EXPORT_SYMBOL(bdev_check_media_change);
-
-/*
- * Separate this part out so that a different pointer for clearing_ptr can be
- * passed in for disk_clear_events.
- */
-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);
-
- disk_check_events(ev, &ev->clearing);
-}
-
-static void disk_check_events(struct disk_events *ev,
- unsigned int *clearing_ptr)
-{
- struct gendisk *disk = ev->disk;
- char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
- unsigned int clearing = *clearing_ptr;
- 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;
- *clearing_ptr &= ~clearing;
-
- intv = disk_events_poll_jiffies(disk);
- if (!ev->block && intv)
- queue_delayed_work(system_freezable_power_efficient_wq,
- &ev->dwork, intv);
-
- spin_unlock_irq(&ev->lock);
-
- /*
- * Tell userland about new events. Only the events listed in
- * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
- * is set. Otherwise, events are processed internally but never
- * get reported to userland.
- */
- for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
- if ((events & disk->events & (1 << i)) &&
- (disk->event_flags & DISK_EVENT_FLAG_UEVENT))
- 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
- * (always empty, only for backwards compatibility)
- * 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);
-
- if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
- return 0;
-
- return __disk_events_show(disk->events, buf);
-}
-
-static ssize_t disk_events_async_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- return 0;
-}
-
-static ssize_t disk_events_poll_msecs_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct gendisk *disk = dev_to_disk(dev);
-
- if (!disk->ev)
- return sprintf(buf, "-1\n");
-
- 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;
-
- if (!disk->ev)
- return -ENODEV;
-
- disk_block_events(disk);
- disk->ev->poll_msecs = intv;
- __disk_unblock_events(disk, true);
-
- return count;
-}
-
-static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
-static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
-static const DEVICE_ATTR(events_poll_msecs, 0644,
- 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/parameters/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_flush_events(ev->disk, 0);
-
- 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_{alloc|add|del|release}_events - initialize and destroy disk_events.
- */
-static void disk_alloc_events(struct gendisk *disk)
-{
- struct disk_events *ev;
-
- if (!disk->fops->check_events || !disk->events)
- return;
-
- ev = kzalloc(sizeof(*ev), GFP_KERNEL);
- if (!ev) {
- pr_warn("%s: failed to initialize events\n", disk->disk_name);
- return;
- }
-
- INIT_LIST_HEAD(&ev->node);
- ev->disk = disk;
- spin_lock_init(&ev->lock);
- mutex_init(&ev->block_mutex);
- ev->block = 1;
- ev->poll_msecs = -1;
- INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
-
- disk->ev = ev;
-}
-
-static void disk_add_events(struct gendisk *disk)
-{
- /* FIXME: error handling */
- 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);
-
- if (!disk->ev)
- return;
-
- mutex_lock(&disk_events_mutex);
- list_add_tail(&disk->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) {
- disk_block_events(disk);
-
- 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);
-}
--
2.30.2
