From: Jarkko Lavinen <jarkko.lavinen@nokia.com>
To: linux-kernel@vger.kernel.org
Cc: David Woodhouse <david.woodhouse@intel.com>,
Maxim Levitsky <maximlevitsky@gmail.com>
Subject: MTD: mtd_blkdevs regression
Date: Fri, 10 Sep 2010 14:04:46 +0300 [thread overview]
Message-ID: <20100910110446.GA28045@angel.research.nokia.com> (raw)
In 2.6.34 modules using add_mtd_blktrans_dev() have reference
count 0 after loading and I can remove the module if it is not
being used.
In 2.6.34, using mtdblock as an example:
# modprobe nandsim
# modprobe mtdblock
# lsmod
Module Size Used by
mtdblock 2829 0
mtd_blkdevs 4217 1 mtdblock
nandsim 25811 0
nand 27184 1 nandsim
nand_ids 2666 2 nandsim,nand
nand_ecc 3392 1 nand
mtd 14794 5 mtd_blkdevs,nandsim,nand
# rmmod mtdblock
#
Since commit 048d871 (mtd: blktrans: Hotplug fixes) in 2.6.35-rc1
add_mtd_blktrans_dev() uses __get_module(tr->owner) to add reference
count to calling module.
Because of this the module cannot be removed and since module
exit cannot be called, del_mtd_blktrans_dev() will not be called,
which would do the module_put().
In 2.6.35:
# modprobe nandsim
# modprobe mtdblock
# lsmod
Module Size Used by
mtdblock 2721 1
mtd_blkdevs 4895 1 mtdblock
nandsim 25819 1
nand 28326 1 nandsim
nand_ids 2698 2 nandsim,nand
nand_ecc 3400 1 nand
mtd 15352 5 mtd_blkdevs,nandsim,nand
# rmmod mtdblock
ERROR: Module mtdblock is in use
#
Jarkko Lavinen
reply other threads:[~2010-09-10 11:05 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20100910110446.GA28045@angel.research.nokia.com \
--to=jarkko.lavinen@nokia.com \
--cc=david.woodhouse@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=maximlevitsky@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®