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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Tested-by: Luca Boccassi <bluca@debian.org>
Link: https://lore.kernel.org/r/20210712230530.29323-6-mcroce@linux.microsoft.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Matteo Croce 2021-07-13 01:05:29 +02:00 committed by Jens Axboe
parent 13927b31b1
commit e6138dc12d
2 changed files with 47 additions and 15 deletions

View File

@ -163,15 +163,31 @@ void disk_flush_events(struct gendisk *disk, unsigned int mask)
spin_unlock_irq(&ev->lock); 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, static void disk_check_events(struct disk_events *ev,
unsigned int *clearing_ptr) unsigned int *clearing_ptr)
{ {
struct gendisk *disk = ev->disk; struct gendisk *disk = ev->disk;
char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
unsigned int clearing = *clearing_ptr; unsigned int clearing = *clearing_ptr;
unsigned int events; unsigned int events;
unsigned long intv; unsigned long intv;
int nr_events = 0, i;
/* check events */ /* check events */
events = disk->fops->check_events(disk, clearing); 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) if (events & DISK_EVENT_MEDIA_CHANGE)
inc_diskseq(disk); inc_diskseq(disk);
/* if (disk->event_flags & DISK_EVENT_FLAG_UEVENT)
* Tell userland about new events. Only the events listed in disk_event_uevent(disk, events);
* @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);
} }
/** /**
@ -284,6 +289,32 @@ bool bdev_check_media_change(struct block_device *bdev)
} }
EXPORT_SYMBOL(bdev_check_media_change); 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 * Separate this part out so that a different pointer for clearing_ptr can be
* passed in for disk_clear_events. * passed in for disk_clear_events.

View File

@ -237,6 +237,7 @@ extern void disk_block_events(struct gendisk *disk);
extern void disk_unblock_events(struct gendisk *disk); extern void disk_unblock_events(struct gendisk *disk);
extern void disk_flush_events(struct gendisk *disk, unsigned int mask); extern void disk_flush_events(struct gendisk *disk, unsigned int mask);
bool set_capacity_and_notify(struct gendisk *disk, sector_t size); 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 */ /* drivers/char/random.c */
extern void add_disk_randomness(struct gendisk *disk) __latent_entropy; extern void add_disk_randomness(struct gendisk *disk) __latent_entropy;