2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Jan Kara <[email protected]> commit 01ea50638bc04ca5259f5711fcdedefcdde1cf43 upstream. When a new disk is being discovered, add_disk() first ties the bdev to gendisk (via register_disk()->blkdev_get()) and only after that calls bdi_register_bdev(). Because register_disk() also creates disk's kobject, it can happen that userspace manages to open and modify the device's data (or inode) before its BDI is properly initialized leading to a warning in __mark_inode_dirty(). Fix the problem by registering BDI early enough. This patch addresses https://bugzilla.kernel.org/show_bug.cgi?id=16312 Reported-by: Larry Finger <[email protected]> Signed-off-by: Jan Kara <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Andi Kleen <[email protected]> --- block/genhd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) Index: linux/block/genhd.c =================================================================== --- linux.orig/block/genhd.c +++ linux/block/genhd.c @@ -541,13 +541,15 @@ void add_disk(struct gendisk *disk) disk->major = MAJOR(devt); disk->first_minor = MINOR(devt); + /* Register BDI before referencing it from bdev */ + bdi = &disk->queue->backing_dev_info; + bdi_register_dev(bdi, disk_devt(disk)); + blk_register_region(disk_devt(disk), disk->minors, NULL, exact_match, exact_lock, disk); register_disk(disk); blk_register_queue(disk); - bdi = &disk->queue->backing_dev_info; - bdi_register_dev(bdi, disk_devt(disk)); retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, "bdi"); WARN_ON(retval); _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
