From: Christoph Hellwig <hch@lst.de>
To: axboe@kernel.dk
Cc: yuyufen@huawei.com, tj@kernel.org, jack@suse.cz,
bvanassche@acm.org, tytso@mit.edu, gregkh@linuxfoundation.org,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/8] bdi: add a ->dev_name field to struct backing_dev_info
Date: Thu, 16 Apr 2020 18:54:48 +0200 [thread overview]
Message-ID: <20200416165453.1080463-4-hch@lst.de> (raw)
In-Reply-To: <20200416165453.1080463-1-hch@lst.de>
Cache a copy of the name for the life time of the backing_dev_info
structure so that we can reference it even after unregistering.
Fixes: 68f23b89067f ("memcg: fix a crash in wb_workfn when a device disappears")
Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/backing-dev-defs.h | 1 +
mm/backing-dev.c | 5 +++--
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index 4fc87dee005a..2849bdbb3acb 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -220,6 +220,7 @@ struct backing_dev_info {
wait_queue_head_t wb_waitq;
struct device *dev;
+ char dev_name[64];
struct device *owner;
struct timer_list laptop_mode_wb_timer;
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index c2c44c89ee5d..efc5b83acd2d 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -938,7 +938,8 @@ int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args)
if (bdi->dev) /* The driver needs to use separate queues per device */
return 0;
- dev = device_create_vargs(bdi_class, NULL, MKDEV(0, 0), bdi, fmt, args);
+ vsnprintf(bdi->dev_name, sizeof(bdi->dev_name), fmt, args);
+ dev = device_create(bdi_class, NULL, MKDEV(0, 0), bdi, bdi->dev_name);
if (IS_ERR(dev))
return PTR_ERR(dev);
@@ -1047,7 +1048,7 @@ const char *bdi_dev_name(struct backing_dev_info *bdi)
{
if (!bdi || !bdi->dev)
return bdi_unknown_name;
- return dev_name(bdi->dev);
+ return bdi->dev_name;
}
EXPORT_SYMBOL_GPL(bdi_dev_name);
--
2.25.1
next prev parent reply other threads:[~2020-04-16 16:55 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-16 16:54 bdi: fix use-after-free for dev_name(bdi->dev) v2 Christoph Hellwig
2020-04-16 16:54 ` [PATCH 1/8] bdi: move bdi_dev_name out of line Christoph Hellwig
2020-04-18 15:35 ` Bart Van Assche
2020-04-16 16:54 ` [PATCH 2/8] bdi: use bdi_dev_name() to get device name Christoph Hellwig
2020-04-18 15:37 ` Bart Van Assche
2020-04-16 16:54 ` Christoph Hellwig [this message]
2020-04-17 8:59 ` [PATCH 3/8] bdi: add a ->dev_name field to struct backing_dev_info Jan Kara
2020-04-17 13:01 ` Christoph Hellwig
2020-04-20 11:41 ` Hans de Goede
2020-04-20 11:58 ` Christoph Hellwig
2020-04-21 12:42 ` Hans de Goede
2020-04-18 15:40 ` Bart Van Assche
2020-04-19 7:58 ` Christoph Hellwig
2020-04-19 15:29 ` Bart Van Assche
2020-04-19 16:06 ` Christoph Hellwig
2020-04-20 7:48 ` Christoph Hellwig
2020-04-20 9:52 ` Jan Kara
2020-04-20 9:49 ` Jan Kara
2020-04-16 16:54 ` [PATCH 4/8] driver core: remove device_create_vargs Christoph Hellwig
2020-04-16 16:54 ` [PATCH 5/8] bdi: unexport bdi_register_va Christoph Hellwig
2020-04-18 15:41 ` Bart Van Assche
2020-04-16 16:54 ` [PATCH 6/8] bdi: remove bdi_register_owner Christoph Hellwig
2020-04-18 15:43 ` Bart Van Assche
2020-04-16 16:54 ` [PATCH 7/8] bdi: simplify bdi_alloc Christoph Hellwig
2020-04-18 15:44 ` Bart Van Assche
2020-04-16 16:54 ` [PATCH 8/8] bdi: remove the name field in struct backing_dev_info Christoph Hellwig
2020-04-18 15:45 ` Bart Van Assche
-- strict thread matches above, loose matches on Subject: below --
2020-04-16 7:15 bdi: fix use-after-free for dev_name(bdi->dev) Christoph Hellwig
2020-04-16 7:15 ` [PATCH 3/8] bdi: add a ->dev_name field to struct backing_dev_info Christoph Hellwig
2020-04-16 7:52 ` Greg KH
2020-04-16 8:34 ` Yufen Yu
2020-04-16 12:02 ` Jan Kara
2020-04-16 12:19 ` Christoph Hellwig
2020-04-16 12:22 ` Christoph Hellwig
2020-04-16 12:31 ` Jan Kara
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