From f1d0b063d993527754f062c589b73f125024d216 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Tue, 2 Dec 2008 10:31:50 -0800 Subject: [PATCH] bdi: register sysfs bdi device only once per queue Devices which share the same queue, like floppies and mtd devices, get registered multiple times in the bdi interface, but bdi accounts only the last registered device of the devices sharing one queue. On remove, all earlier registered devices leak, stay around in sysfs, and cause "duplicate filename" errors if the devices are re-created. This prevents the creation of multiple bdi interfaces per queue, and the bdi device will carry the dev_t name of the block device which is the first one registered, of the pool of devices using the same queue. [akpm@linux-foundation.org: add a WARN_ON so we know which drivers are misbehaving] Tested-by: Peter Korsgaard Acked-by: Peter Zijlstra Signed-off-by: Kay Sievers Cc: David Woodhouse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/backing-dev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/backing-dev.c b/mm/backing-dev.c index f2e574dbc300..2a56124dbc28 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -176,6 +176,9 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, int ret = 0; struct device *dev; + if (WARN_ON(bdi->dev)) + goto exit; + va_start(args, fmt); dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args); va_end(args); -- 2.20.1