| Message ID | 20210426055036.2103620-1-naohiro.aota@wdc.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | implement zone-aware probing/wiping for zoned btrfs | expand |
On Mon, Apr 26, 2021 at 02:50:33PM +0900, Naohiro Aota wrote: > Naohiro Aota (3): > blkid: implement zone-aware probing > blkid: add magic and probing for zoned btrfs > blkid: support zone reset for wipefs > > include/blkdev.h | 9 ++ > lib/blkdev.c | 29 ++++++ > libblkid/src/blkidP.h | 5 + > libblkid/src/probe.c | 99 +++++++++++++++++-- > libblkid/src/superblocks/btrfs.c | 159 ++++++++++++++++++++++++++++++- > 5 files changed, 292 insertions(+), 9 deletions(-) Merged to the "next" branch (on github) and it will be merged to the "master" later after v2.37 release. Thanks! (and extra thank for the examples :-) Karel
This series implements probing and wiping of the superblock of zoned btrfs. Changes: - v3: - Implement and use blkdev_get_zonereport() - Also modify blkid_clone_probe() for completeness - Drop temporary btrfs magic from the table - Do not try to aggressively copy-paste the kernel side code - Fix commit log - v2: - Fix zone alignment calculation - Fix the build without HAVE_LINUX_BLKZONED_H Zoned btrfs is merged with this series: https://lore.kernel.org/linux-btrfs/20210222160049.GR1993@twin.jikos.cz/T/ And, superblock locations are finalized with this patch: https://lore.kernel.org/linux-btrfs/BL0PR04MB651442E6ACBF48342BD00FEBE7719@BL0PR04MB6514.namprd04.prod.outlook.com/T/ Corresponding btrfs-progs is available here: https://github.com/naota/btrfs-progs/tree/btrfs-zoned 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. * Testing device You need devices with zone append writing command support to run ZONED btrfs. Other than real devices, null_blk supports zone append write command. You can use memory backed null_blk to run the test on it. Following script creates 12800 MB /dev/nullb0 filled with 4MB zones. sysfs=/sys/kernel/config/nullb/nullb0 size=12800 # MB zone_size= 4 # MB # drop nullb0 if [[ -d $sysfs ]]; then echo 0 > "${sysfs}"/power rmdir $sysfs fi lsmod | grep -q null_blk && rmmod null_blk modprobe null_blk nr_devices=0 mkdir "${sysfs}" echo "${size}" > "${sysfs}"/size echo 1 > "${sysfs}"/zoned echo "${zone_size}" > "${sysfs}"/zone_size echo 0 > "${sysfs}"/zone_nr_conv echo 1 > "${sysfs}"/memory_backed echo 1 > "${sysfs}"/power udevadm settle Zoned SCSI devices such as SMR HDDs or scsi_debug also support the zone append command as an emulated command within the SCSI sd driver. This emulation is completely transparent to the user and provides the same semantic as a NVMe ZNS native drive support. Also, there is a qemu patch available to enable NVMe ZNS device. Then, you can create zoned btrfs with the above btrfs-progs. $ mkfs.btrfs -d single -m single /dev/nullb0 btrfs-progs v5.11 See http://btrfs.wiki.kernel.org for more information. ERROR: superblock magic doesn't match /dev/nullb0: host-managed device detected, setting zoned feature Resetting device zones /dev/nullb0 (3200 zones) ... Label: (null) UUID: 1e5912a2-b5c3-46fb-aa9a-ee3d073ff600 Node size: 16384 Sector size: 4096 Filesystem size: 12.50GiB Block group profiles: Data: single 4.00MiB Metadata: single 4.00MiB System: single 4.00MiB SSD detected: yes Zoned device: yes Zone size: 4.00MiB Incompat features: extref, skinny-metadata, zoned Runtime features: Checksum: crc32c Number of devices: 1 Devices: ID SIZE PATH 1 12.50GiB /dev/nullb0 $ mount /dev/nullb0 /mnt/somewhere $ dmesg | tail ... [272816.682461] BTRFS: device fsid 1e5912a2-b5c3-46fb-aa9a-ee3d073ff600 devid 1 transid 5 /dev/nullb0 scanned by mkfs.btrfs (44367) [272883.678401] BTRFS info (device nullb0): has skinny extents [272883.686373] BTRFS info (device nullb0): flagging fs with big metadata feature [272883.699020] BTRFS info (device nullb0): host-managed zoned block device /dev/nullb0, 3200 zones of 4194304 bytes [272883.711736] BTRFS info (device nullb0): zoned mode enabled with zone size 4194304 [272883.722388] BTRFS info (device nullb0): enabling ssd optimizations [272883.731332] BTRFS info (device nullb0): checking UUID tree Naohiro Aota (3): blkid: implement zone-aware probing blkid: add magic and probing for zoned btrfs blkid: support zone reset for wipefs include/blkdev.h | 9 ++ lib/blkdev.c | 29 ++++++ libblkid/src/blkidP.h | 5 + libblkid/src/probe.c | 99 +++++++++++++++++-- libblkid/src/superblocks/btrfs.c | 159 ++++++++++++++++++++++++++++++- 5 files changed, 292 insertions(+), 9 deletions(-)