On 11/28/20 5:14 PM, Christoph Hellwig wrote:
To simplify block device lookup and a few other upcoming areas, make sure that we always have a struct block_device available for each disk and each partition, and only find existing block devices in bdget. The only downside of this is that each device and partition uses a little more memory. The upside will be that a lot of code can be simplified.With that all we need to look up the block device is to lookup the inode and do a few sanity checks on the gendisk, instead of the separate lookup for the gendisk. For blk-cgroup which wants to access a gendisk without opening it, a new blkdev_{get,put}_no_open low-level interface is added to replace the previous get_gendisk use. Note that the change to look up block device directly instead of the two step lookup using struct gendisk causes a subtile change in behavior: accessing a non-existing partition on an existing block device can now cause a call to request_module. That call is harmless, and in practice no recent system will access these nodes as they aren't created by udev and static /dev/ setups are unusual. Signed-off-by: Christoph Hellwig <h...@lst.de> --- block/blk-cgroup.c | 42 ++++---- block/blk-iocost.c | 36 +++---- block/blk.h | 2 +- block/genhd.c | 210 +++++-------------------------------- block/partitions/core.c | 29 ++--- fs/block_dev.c | 177 +++++++++++++++++-------------- include/linux/blk-cgroup.h | 4 +- include/linux/blkdev.h | 6 ++ include/linux/genhd.h | 7 +- 9 files changed, 194 insertions(+), 319 deletions(-)
Reviewed-by: Hannes Reinecke <h...@suse.de> Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect h...@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel
