This series implements probing and wiping of the superblock of zoned btrfs. Zoned btrfs is merged with this series: https://lore.kernel.org/linux-btrfs/20210222160049.GR1993@xxxxxxxxxxxxx/T/ And, superblock locations are finalized with this patch: https://lore.kernel.org/linux-btrfs/BL0PR04MB651442E6ACBF48342BD00FEBE7719@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/T/ A zoned block device consists of a number of zones. Zones are either conventional and accepting random writes or sequential and requiring that writes be issued in LBA order from each zone write pointer position. Superblock (and its copies) is the only data structure in btrfs with a fixed location on a device. Since we cannot overwrite in a sequential write required zone, we cannot place superblock in the zone. Thus, zoned btrfs use superblock log writing to update superblock on sequential write required zones. It uses two zones as a circular buffer to write updated superblocks. Once the first zone is filled up, start writing into the second buffer. When both zones are filled up and before start writing to the first zone again, it reset the first zone. This series first implements zone based detection of the magic location. Then, it adds magics for zoned btrfs and implements a probing function to detect the latest superblock. Finally, this series also implements zone-aware wiping by zone resetting. Naohiro Aota (3): blkid: implement zone-aware probing blkid: add magic and probing for zoned btrfs blkid: support zone reset for wipefs configure.ac | 1 + libblkid/src/blkidP.h | 5 + libblkid/src/probe.c | 91 ++++++++++++++-- libblkid/src/superblocks/btrfs.c | 178 ++++++++++++++++++++++++++++++- 4 files changed, 266 insertions(+), 9 deletions(-) -- 2.31.1
