From e6138dc12de9df17cbda9c40314d69592855ac5e Mon Sep 17 00:00:00 2001 From: Matteo Croce Date: Tue, 13 Jul 2021 01:05:29 +0200 Subject: 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 Signed-off-by: Christoph Hellwig Signed-off-by: Matteo Croce Tested-by: Luca Boccassi Link: https://lore.kernel.org/r/20210712230530.29323-6-mcroce@linux.microsoft.com Signed-off-by: Jens Axboe --- block/disk-events.c | 61 ++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 46 insertions(+), 15 deletions(-) (limited to 'block/disk-events.c') diff --git a/block/disk-events.c b/block/disk-events.c index 04c52f3992ed..7445b8ff2775 100644 --- a/block/disk-events.c +++ b/block/disk-events.c @@ -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. -- cgit v1.2.3