From: Randy Dunlap <rdunlap@infradead.org>
To: Danil Kipnis <danil.kipnis@cloud.ionos.com>,
linux-block@vger.kernel.org, linux-rdma@vger.kernel.org,
dledford@redhat.com, jgg@ziepe.ca
Cc: axboe@kernel.dk, bvanassche@acm.org, leon@kernel.org,
jinpu.wang@cloud.ionos.com, guoqing.jiang@cloud.ionos.com
Subject: Re: [PATCH] rnbd: fix compilation error when CONFIG_MODULES is disabled
Date: Thu, 21 May 2020 11:39:49 -0700 [thread overview]
Message-ID: <ca0729a1-2e4d-670d-2519-a175b3035b28@infradead.org> (raw)
In-Reply-To: <20200521175001.445208-1-danil.kipnis@cloud.ionos.com>
On 5/21/20 10:50 AM, Danil Kipnis wrote:
> module_is_live function is only defined when CONFIG_MODULES is enabled.
> Use try_module_get instead to check whether the module is being removed.
>
> When module unload and manuall unmapping is happening in parallel, we can
> try removing the symlink twice: rnbd_client_exit vs. rnbd_clt_unmap_dev_store.
>
> This is probably not the best way to deal with this race in general, but for
> now this fixes the compilation issue when CONFIG_MODULES is disabled and has
> no functional impact. Regression tests passed.
>
> Fixes: 1eb54f8f5dd8 block/rnbd: client: sysfs interface functions
The Fixes: line has a specific expected format. It should be like this:
Fixes: 1eb54f8f5dd8 ("block/rnbd: client: sysfs interface functions")
> Reported-by: Randy Dunlap <rdunlap@infradead.org>
> Suggested-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
> Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Thanks.
> ---
> drivers/block/rnbd/rnbd-clt-sysfs.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/block/rnbd/rnbd-clt-sysfs.c b/drivers/block/rnbd/rnbd-clt-sysfs.c
> index a4508fcc7ffe..73d7cb40abb3 100644
> --- a/drivers/block/rnbd/rnbd-clt-sysfs.c
> +++ b/drivers/block/rnbd/rnbd-clt-sysfs.c
> @@ -428,12 +428,14 @@ static struct attribute *rnbd_dev_attrs[] = {
> void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev)
> {
> /*
> - * The module_is_live() check is crucial and helps to avoid annoying
> - * sysfs warning raised in sysfs_remove_link(), when the whole sysfs
> - * path was just removed, see rnbd_close_sessions().
> + * The module unload rnbd_client_exit path is racing with unmapping of the
> + * last single device from the sysfs manually i.e. rnbd_clt_unmap_dev_store()
> + * leading to a sysfs warning because of sysfs link already was removed already.
> */
> - if (strlen(dev->blk_symlink_name) && module_is_live(THIS_MODULE))
> + if (strlen(dev->blk_symlink_name) && try_module_get(THIS_MODULE)) {
> sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name);
> + module_put(THIS_MODULE);
> + }
> }
>
> static struct kobj_type rnbd_dev_ktype = {
>
> base-commit: f11e0ec55f0c80ff47693af2150bad5db0e20387
>
--
~Randy
next prev parent reply other threads:[~2020-05-21 18:39 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <86962843-e786-4a3f-0b85-1e06fbdbd76a@infradead.org>
2020-05-21 17:50 ` [PATCH] rnbd: fix compilation error when CONFIG_MODULES is disabled Danil Kipnis
2020-05-21 18:39 ` Randy Dunlap [this message]
2020-05-21 18:59 ` Danil Kipnis
2020-05-23 0:24 ` Jason Gunthorpe
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=ca0729a1-2e4d-670d-2519-a175b3035b28@infradead.org \
--to=rdunlap@infradead.org \
--cc=axboe@kernel.dk \
--cc=bvanassche@acm.org \
--cc=danil.kipnis@cloud.ionos.com \
--cc=dledford@redhat.com \
--cc=guoqing.jiang@cloud.ionos.com \
--cc=jgg@ziepe.ca \
--cc=jinpu.wang@cloud.ionos.com \
--cc=leon@kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
/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;
as well as URLs for NNTP newsgroup(s).