From: Christoph Hellwig <hch@infradead.org>
To: Matteo Croce <mcroce@linux.microsoft.com>
Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Jens Axboe <axboe@kernel.dk>,
linux-kernel@vger.kernel.org,
Lennart Poettering <lennart@poettering.net>,
Luca Boccassi <bluca@debian.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Damien Le Moal <damien.lemoal@wdc.com>, Tejun Heo <tj@kernel.org>,
Javier Gonz??lez <javier@javigon.com>,
Niklas Cassel <niklas.cassel@wdc.com>,
Johannes Thumshirn <johannes.thumshirn@wdc.com>,
Hannes Reinecke <hare@suse.de>,
Matthew Wilcox <willy@infradead.org>,
Christoph Hellwig <hch@infradead.org>,
JeffleXu <jefflexu@linux.alibaba.com>
Subject: Re: [PATCH v4 5/5] loop: raise media_change event
Date: Mon, 12 Jul 2021 07:54:44 +0100 [thread overview]
Message-ID: <YOvnNE6AVNwEh8uE@infradead.org> (raw)
In-Reply-To: <20210711175415.80173-6-mcroce@linux.microsoft.com>
So when I said plug into the disk events I did not mean that you need
to use all the polling stuff - we can just do the parts required
which are the uevents and invalidation with a new little helper
like this (needs the actual prototype and kerneldoc of course):
diff --git a/block/disk-events.c b/block/disk-events.c
index a75931ff5da4..0023ab1559b6 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);
@@ -190,19 +206,8 @@ static void disk_check_events(struct disk_events *ev,
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);
+ if (disk->event_flags & DISK_EVENT_FLAG_UEVENT)
+ disk_event_uevent(disk, events);
}
/**
@@ -281,6 +286,21 @@ bool bdev_check_media_change(struct block_device *bdev)
}
EXPORT_SYMBOL(bdev_check_media_change);
+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.
prev parent reply other threads:[~2021-07-12 7:09 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-11 17:54 [PATCH v4 0/5] block: add a sequence number to disks Matteo Croce
2021-07-11 17:54 ` [PATCH v4 1/5] block: add disk sequence number Matteo Croce
2021-07-12 6:25 ` Christoph Hellwig
2021-07-11 17:54 ` [PATCH v4 2/5] block: export the diskseq in uevents Matteo Croce
2021-07-12 6:26 ` Christoph Hellwig
2021-07-11 17:54 ` [PATCH v4 3/5] block: add ioctl to read the disk sequence number Matteo Croce
2021-07-12 6:28 ` Christoph Hellwig
2021-07-12 19:22 ` Elliott, Robert (Servers)
2021-07-12 23:25 ` Matteo Croce
2021-07-13 5:59 ` Christoph Hellwig
2021-07-11 17:54 ` [PATCH v4 4/5] block: export diskseq in sysfs Matteo Croce
2021-07-12 6:29 ` Christoph Hellwig
2021-07-11 17:54 ` [PATCH v4 5/5] loop: raise media_change event Matteo Croce
2021-07-12 6:54 ` Christoph Hellwig [this message]
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