This series of patches introduces changes to zoned block device handling code with the intent to simplify the code while optimizing run-time operation, particularly in the area of zone reporting. The first patch lifts the device zone check code out of the sd driver and reimplements these zone checks generically as part of blk_revalidate_disk_zones(). This avoids zoned block device drivers to have to implement these checks. The second patch simplifies this function code for the !zoned case. The third patch is a small cleanup of zone report processing in preparation for the fourth patch which removes support for partitions on zoned block devices. As mentioned in that patch commit message, none of the known partitioning tools support zoned devices and there are no known use case in the field of SMR disks being used with partitions. Dropping partition supports allows to significantly simplify the code for zone report as zone sector values remapping becomes unnecessary. Patch 5 to 6 are small cleanups and fixes of the null_blk driver zoned mode. The prep patch 7 optimizes zone report buffer allocation for the SCSI sd driver. Finally, patch 8 introduces a new interface for report zones handling using a callback function executed per zone reported by the device. This allows avoiding the need to allocate large arrays of blk_zone structures for the execution of zone reports. This can significantly reduce memory usage and pressure on the memory management system while significantly simplify the code all over. Overall, this series not only reduces significantly the code size, it also improves run-time memory usage for zone report execution. This series applies cleanly on the for-next block tree on top of the zone management operation series. It may however create a conflict with Christoph's reqork of disk size revalidation. Please consider this series for inclusion in the 5.5 kernel. As always, comments are welcome. Changes from V1: * Use __GFP_NORETRY in patch 8 as suggested by Bart. * Added reviewed-by tags. Christoph Hellwig (4): block: cleanup the !zoned case in blk_revalidate_disk_zones null_blk: clean up the block device operations null_blk: clean up report zones block: rework zone reporting Damien Le Moal (5): block: Enhance blk_revalidate_disk_zones() block: Simplify report zones execution block: Remove partition support for zoned block devices null_blk: Add zone_nr_conv to features scsi: sd_zbc: Cleanup sd_zbc_alloc_report_buffer() block/blk-core.c | 6 +- block/blk-zoned.c | 356 ++++++++++++++------------------- block/partition-generic.c | 74 +------ drivers/block/null_blk.h | 11 +- drivers/block/null_blk_main.c | 21 +- drivers/block/null_blk_zoned.c | 33 ++- drivers/md/dm-flakey.c | 18 +- drivers/md/dm-linear.c | 20 +- drivers/md/dm-zoned-metadata.c | 131 +++++------- drivers/md/dm.c | 130 +++++------- drivers/scsi/sd.h | 4 +- drivers/scsi/sd_zbc.c | 237 ++++++++-------------- fs/f2fs/super.c | 51 ++--- include/linux/blkdev.h | 15 +- include/linux/device-mapper.h | 24 ++- 15 files changed, 429 insertions(+), 702 deletions(-) -- 2.23.0
