Commit e6138dc1 authored by Matteo Croce's avatar Matteo Croce Committed by Jens Axboe
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block: add a helper to raise a media changed event 



Refactor disk_check_events() and move some code into disk_event_uevent().
Then add disk_force_media_change(), a helper which will be used by
devices to force issuing a DISK_EVENT_MEDIA_CHANGE event.

Co-developed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMatteo Croce <mcroce@microsoft.com>
Tested-by: default avatarLuca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-6-mcroce@linux.microsoft.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 13927b31

block/disk-events.c

+46 −15
Original line number Diff line number Diff line
@@ -163,15 +163,31 @@ void disk_flush_events(struct gendisk *disk, unsigned int mask) 
	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.

 */

static void disk_event_uevent(struct gendisk *disk, unsigned int events)

{

	char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };

	int nr_events = 0, i;



	for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)

		if (events & disk->events & (1 << i))

			envp[nr_events++] = disk_uevents[i];



	if (nr_events)

		kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);

}



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);
@@ -193,19 +209,8 @@ static void disk_check_events(struct disk_events *ev, 
	if (events & DISK_EVENT_MEDIA_CHANGE)

		inc_diskseq(disk);



	/*

	 * 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);

	if (disk->event_flags & DISK_EVENT_FLAG_UEVENT)

		disk_event_uevent(disk, events);

}



/**
@@ -284,6 +289,32 @@ bool bdev_check_media_change(struct block_device *bdev) 
}

EXPORT_SYMBOL(bdev_check_media_change);



/**

 * disk_force_media_change - force a media change event

 * @disk: the disk which will raise the event

 * @events: the events to raise

 *

 * Generate uevents for the disk. If DISK_EVENT_MEDIA_CHANGE is present,

 * attempt to free all dentries and inodes and invalidates all block

 * device page cache entries in that case.

 *

 * Returns %true if DISK_EVENT_MEDIA_CHANGE was raised, or %false if not.

 */

bool disk_force_media_change(struct gendisk *disk, unsigned int events)

{

	disk_event_uevent(disk, events);



	if (!(events & DISK_EVENT_MEDIA_CHANGE))

		return false;



	if (__invalidate_device(disk->part0, true))

		pr_warn("VFS: busy inodes on changed media %s\n",

			disk->disk_name);

	set_bit(GD_NEED_PART_SCAN, &disk->state);

	return true;

}

EXPORT_SYMBOL_GPL(disk_force_media_change);



/*

 * Separate this part out so that a different pointer for clearing_ptr can be

 * passed in for disk_clear_events.

include/linux/genhd.h

+1 −0
Original line number Diff line number Diff line
@@ -237,6 +237,7 @@ extern void disk_block_events(struct gendisk *disk); 
extern void disk_unblock_events(struct gendisk *disk);

extern void disk_flush_events(struct gendisk *disk, unsigned int mask);

bool set_capacity_and_notify(struct gendisk *disk, sector_t size);

bool disk_force_media_change(struct gendisk *disk, unsigned int events);



/* drivers/char/random.c */

extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;