| Message ID | 20200422073851.303714-5-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/9] vboxsf: don't use the source name in the bdi name | expand |
On Wed 22-04-20 09:38:46, Christoph Hellwig wrote: > 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> Looks good to me. You can add: Reviewed-by: Jan Kara <jack@suse.cz> Honza > --- > 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); > > -- > 2.26.1 >
On 4/22/20 12:38 AM, Christoph Hellwig wrote: > 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. Reviewed-by: Bart Van Assche <bvanassche@acm.org>
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);
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(-)