From: Lukas Herbolt <lukas@herbolt.com>
To: hch@infradead.org, aalbersh@redhat.com, cem@kernel.org
Cc: linux-xfs@vger.kernel.org, Lukas Herbolt <lukas@herbolt.com>
Subject: [PATCH 0/1] mkfs.xfs fix sunit size on 512e and 4kN disks.
Date: Thu, 19 Feb 2026 12:44:06 +0100 [thread overview]
Message-ID: <20260219114405.31521-3-lukas@herbolt.com> (raw)
Creating of XFS on 4kN or 512e disk result in suboptimal LSU/LSUNIT.
As of now we check if the sectorsize is bigger than XLOG_HEADER_SIZE
and so we set lsu to blocksize. But we do not check the the size if
lsunit can be bigger to fit the disk geometry.
It was laready discussed here:
- https://lore.kernel.org/linux-xfs/aOX_TzJIxJWWC63x@infradead.org/
but it somehow fell of the plate.
Before:
modprobe scsi_debug inq_vendor=XFS_TEST physblk_exp=3 sector_size=512 \
opt_xferlen_exp=9 opt_blks=512 dev_size_mb=100 virtual_gb=1000; \
lsblk -tQ 'VENDOR == "XFS_TEST"'; \
mkfs.xfs -f $(lsblk -Q 'VENDOR == "XFS_TEST"' -no path) 2>/dev/null; sleep 1; \
modprobe -r scsi_debug
NAME ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCHED RQ-SIZE RA WSAME
sda 0 262144 262144 4096 512 0 bfq 256 512 0B
meta-data=/dev/sda isize=512 agcount=32, agsize=8192000 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=1
= reflink=1 bigtime=1 inobtcount=1 nrext64=1
= exchange=0
data = bsize=4096 blocks=262144000, imaxpct=25
= sunit=64 swidth=64 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1, parent=0
log =internal log bsize=4096 blocks=128000, version=2
= sectsz=4096 sunit=1 blks, lazy-count=1
^^^^^^^^^^^^^^
realtime =none extsz=4096 blocks=0, rtextents=0
After:
modprobe scsi_debug inq_vendor=XFS_TEST physblk_exp=3 sector_size=512 \
opt_xferlen_exp=9 opt_blks=512 dev_size_mb=100 virtual_gb=1000; \
lsblk -tQ 'VENDOR == "XFS_TEST"'; \
mkfs.xfs -f $(lsblk -Q 'VENDOR == "XFS_TEST"' -no path) 2>/dev/null; sleep 1; \
modprobe -r scsi_debug
NAME ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCHED RQ-SIZE RA WSAME
sda 0 262144 262144 4096 512 0 bfq 256 512 0B
meta-data=/dev/sda isize=512 agcount=32, agsize=8192000 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=1
= reflink=1 bigtime=1 inobtcount=1 nrext64=1
= exchange=0 metadir=0
data = bsize=4096 blocks=262144000, imaxpct=25
= sunit=64 swidth=64 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1, parent=0
log =internal log bsize=4096 blocks=128000, version=2
= sectsz=4096 sunit=64 blks, lazy-count=1
^^^^^^^^^^^^^^
realtime =none extsz=4096 blocks=0, rtextents=0
= rgcount=0 rgsize=0 extents
= zoned=0 start=0 reserved=0
Lukas Herbolt (1):
mkfs.xfs fix sunit size on 512e and 4kN disks.
mkfs/xfs_mkfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--
2.53.0
next reply other threads:[~2026-02-19 11:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-19 11:44 Lukas Herbolt [this message]
2026-02-19 11:44 ` [PATCH 1/1] mkfs.xfs fix sunit size on 512e and 4kN disks Lukas Herbolt
2026-02-19 13:32 ` Christoph Hellwig
2026-03-04 19:49 ` Darrick J. Wong
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