This series improves zoned block device support (reduce overhead) and introduces many simplifications to the code (overall, there are more deletions than insertions). In more details: * Patches 1 to 3 are SCSI side (sd driver) cleanups and improvements reducing the overhead of report zones command execution during disk scan and revalidation. * Patches 4 to 9 improve the useability and user API of zoned block devices. * Patch 10 is the main part of this series. This patch replaces the REQ_OP_ZONE_REPORT BIO/request operation for executing report zones commands with a block device file operation, removing the need for the command reply payload in-place rewriting in the BIO buffer. This leads to major simplification of the code in many places. * Patch 11 further simplifies the code of low level drivers by providing a generic implementation of zoned block device request queue zone bitmaps initialization and revalidation. Please consider the addition of these patches in 4.20. Comments are as always welcome. Changes from v2: * Reworked patch 9 to preserve the declaration of struct request_queue nr_zones field being conditional on CONFIG_BLK_DEV_ZONED Changes from v1: * Addressed Christoph's and Bart's comments * Fixed several compilation errors with zoned block device support disabled * Rebased on latest rc including the most recent dm patches Christoph Hellwig (1): block: add a report_zones method Damien Le Moal (10): scsi: sd_zbc: Rearrange code scsi: sd_zbc: Reduce boot device scan and revalidate time scsi: sd_zbc: Fix sd_zbc_check_zones() error checks block: Introduce blkdev_nr_zones() helper block: Limit allocation of zone descriptors for report zones block: Introduce BLKGETZONESZ ioctl block: Introduce BLKGETNRZONES ioctl block: Improve zone reset execution block: Expose queue nr_zones in sysfs block: Introduce blk_revalidate_disk_zones() block/blk-core.c | 1 - block/blk-lib.c | 13 +- block/blk-mq-debugfs.c | 1 - block/blk-sysfs.c | 13 + block/blk-zoned.c | 359 +++++++++++++++--------- block/blk.h | 8 + block/ioctl.c | 4 + drivers/block/null_blk.h | 11 +- drivers/block/null_blk_main.c | 30 +- drivers/block/null_blk_zoned.c | 57 +--- drivers/md/dm-flakey.c | 30 +- drivers/md/dm-linear.c | 35 ++- drivers/md/dm-table.c | 10 + drivers/md/dm-zoned-target.c | 3 +- drivers/md/dm.c | 169 ++++++----- drivers/scsi/sd.c | 15 +- drivers/scsi/sd.h | 15 +- drivers/scsi/sd_zbc.c | 497 +++++++++------------------------ include/linux/blk_types.h | 2 - include/linux/blkdev.h | 22 +- include/linux/device-mapper.h | 12 +- include/trace/events/f2fs.h | 1 - include/uapi/linux/blkzoned.h | 3 + 23 files changed, 591 insertions(+), 720 deletions(-) -- 2.17.1 Christoph Hellwig (1): block: add a report_zones method Damien Le Moal (10): scsi: sd_zbc: Rearrange code scsi: sd_zbc: Reduce boot device scan and revalidate time scsi: sd_zbc: Fix sd_zbc_check_zones() error checks block: Introduce blkdev_nr_zones() helper block: Limit allocation of zone descriptors for report zones block: Introduce BLKGETZONESZ ioctl block: Introduce BLKGETNRZONES ioctl block: Improve zone reset execution block: Expose queue nr_zones in sysfs block: Introduce blk_revalidate_disk_zones() block/blk-core.c | 1 - block/blk-lib.c | 13 +- block/blk-mq-debugfs.c | 1 - block/blk-sysfs.c | 13 + block/blk-zoned.c | 359 +++++++++++++++--------- block/blk.h | 8 + block/ioctl.c | 4 + drivers/block/null_blk.h | 11 +- drivers/block/null_blk_main.c | 30 +- drivers/block/null_blk_zoned.c | 57 +--- drivers/md/dm-flakey.c | 30 +- drivers/md/dm-linear.c | 35 ++- drivers/md/dm-table.c | 10 + drivers/md/dm-zoned-target.c | 3 +- drivers/md/dm.c | 169 ++++++----- drivers/scsi/sd.c | 15 +- drivers/scsi/sd.h | 15 +- drivers/scsi/sd_zbc.c | 497 +++++++++------------------------ include/linux/blk_types.h | 2 - include/linux/blkdev.h | 30 +- include/linux/device-mapper.h | 12 +- include/trace/events/f2fs.h | 1 - include/uapi/linux/blkzoned.h | 3 + 23 files changed, 600 insertions(+), 719 deletions(-) -- 2.17.1