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Date: Fri, 18 May 2018 14:55:54 +0200
From: Lars Ellenberg <lars.ellenberg@linbit.com>
To: Christoph Hellwig <hch@lst.de>
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Cc: linux-rtc@vger.kernel.org, Alessandro Zummo <a.zummo@towertech.it>,
	Alexandre Belloni <alexandre.belloni@bootlin.com>,
	devel@driverdev.osuosl.org, linux-scsi@vger.kernel.org,
	linux-acpi@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jslaby@suse.com>, megaraidlinux.pdl@broadcom.com,
	linux-kernel@vger.kernel.org,
	Alexey Dobriyan <adobriyan@gmail.com>, linux-ide@vger.kernel.org,
	netfilter-devel@vger.kernel.org,
	Alexander Viro <viro@zeniv.linux.org.uk>, netdev@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-ext4@vger.kernel.org, linux-afs@lists.infradead.org,
	jfs-discussion@lists.sourceforge.net, drbd-dev@lists.linbit.com
Subject: Re: [Drbd-dev] [PATCH 28/42] drbd: switch to proc_create_single
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On Wed, May 16, 2018 at 11:43:32AM +0200, Christoph Hellwig wrote:
> And stop messing with try_module_get on THIS_MODULE, which doesn't make
> any sense here.

The idea was to increase module count on /proc/drbd access.

If someone holds /proc/drbd open, previously rmmod would
"succeed" in starting the unload, but then block on remove_proc_entry,
leading to a situation where the lsmod does not show drbd anymore,
but /proc/drbd being still there (but no longer accessible).

I'd rather have rmmod fail up front in this case.
And try_module_get() seemed most appropriate.

    Lars