From eb7ae5e06bb6e6ac6bb86872d27c43ebab92f6b2 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 4 May 2020 14:47:54 +0200 Subject: bdi: move bdi_dev_name out of line bdi_dev_name is not a fast path function, move it out of line. This prepares for using it from modular callers without having to export an implementation detail like bdi_unknown_name. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Greg Kroah-Hartman Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe --- include/linux/backing-dev.h | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h index f88197c1ffc2..c9ad5c3b7b4b 100644 --- a/include/linux/backing-dev.h +++ b/include/linux/backing-dev.h @@ -505,13 +505,6 @@ static inline int bdi_rw_congested(struct backing_dev_info *bdi) (1 << WB_async_congested)); } -extern const char *bdi_unknown_name; - -static inline const char *bdi_dev_name(struct backing_dev_info *bdi) -{ - if (!bdi || !bdi->dev) - return bdi_unknown_name; - return dev_name(bdi->dev); -} +const char *bdi_dev_name(struct backing_dev_info *bdi); #endif /* _LINUX_BACKING_DEV_H */ -- cgit v1.2.3 From 6bd87eec23cbc9ed222bed0f5b5b02bf300e9a8d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 4 May 2020 14:47:56 +0200 Subject: bdi: add a ->dev_name field to struct backing_dev_info 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 Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe --- include/linux/backing-dev-defs.h | 1 + mm/backing-dev.c | 5 +++-- 2 files changed, 4 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h index ee577a83cfe6..7367150f962a 100644 --- a/include/linux/backing-dev-defs.h +++ b/include/linux/backing-dev-defs.h @@ -219,6 +219,7 @@ 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); -- cgit v1.2.3