Public bug reported:
my environment: Ubuntu 22.04LTS with ext4 filesystem and extent maps
find(1) utility has a value for sparseness.
I wanted to understand the extent mapping and focused on files with sparseness
< 1.0
I have a shell script for filtering to "0.99" sparseness.
I use this file with "dd"
e.g.
root@prod:/home/bernie22# dd bs=512 if=/usr/lib/locale/locale-archive
of=/dev/null
11855+1 records in
11855+1 records out
6070224 bytes (6,1 MB, 5,8 MiB) copied, 0,0214176 s, 283 MB/s
next is a test c source code for statx(2)
root@prod:/home/bernie22# bin/test-statx /usr/lib/locale/locale-archive
statx(/usr/lib/locale/locale-archive) = 0
results=1fff (stx_blocks is mask 0x400U)
Size: 6070224 Blocks: 11784 IO Block: 4096 regular file
Device: 08:06 Inode: 132054 Links: 1
Access: (0644/-rw-r--r--) Uid: 0 Gid: 0
Access: 2026-01-04 19:13:05.892648968+0100
Modify: 2025-09-23 08:15:00.123602960+0200
Change: 2025-09-23 08:15:00.123602960+0200
Birth: 2025-09-23 08:14:18.109533887+0200
Attributes: 0000000000000000 (........ ........ ........ ........ ........
..--.... ..---... .---.-..)
Note: the block difference between "dd" and statx(2) return. the
statx(2) mask stx_mask reports a correcly filled in stx_blocks value
root@prod:/home/bernie22# filefrag -sv /usr/lib/locale/locale-archive
Filesystem type is: ef53
File size of /usr/lib/locale/locale-archive is 6070224 (1482 blocks of 4096
bytes)
ext: logical_offset: physical_offset: length: expected: flags:
0: 0.. 2: 6175232.. 6175234: 3:
1: 4.. 5: 6175236.. 6175237: 2:
2: 15.. 511: 6175247.. 6175743: 497:
3: 512.. 831: 5596672.. 5596991: 320: 6175744:
4: 832.. 833: 5571130.. 5571131: 2: 5596992:
5: 834.. 1466: 5580506.. 5581138: 633: 5571132:
6: 1467.. 1467: 5571241.. 5571241: 1: 5581139:
7: 1468.. 1468: 5571283.. 55712root@prod:/home/bernie22#
filefrag -sv /usr/lib/locale/locale-archive
Filesystem type is: ef53
File size of /usr/lib/locale/locale-archive is 6070224 (1482 blocks of 4096
bytes)
ext: logical_offset: physical_offset: length: expected: flags:
0: 0.. 2: 6175232.. 6175234: 3:
1: 4.. 5: 6175236.. 6175237: 2:
2: 15.. 511: 6175247.. 6175743: 497:
3: 512.. 831: 5596672.. 5596991: 320: 6175744:
4: 832.. 833: 5571130.. 5571131: 2: 5596992:
5: 834.. 1466: 5580506.. 5581138: 633: 5571132:
6: 1467.. 1467: 5571241.. 5571241: 1: 5581139:
7: 1468.. 1468: 5571283.. 5571283: 1: 5571242:
8: 1469.. 1469: 5571242.. 5571242: 1: 5571284:
9: 1470.. 1471: 5571280.. 5571281: 2: 5571243:
10: 1472.. 1473: 5571318.. 5571319: 2: 5571282:
11: 1474.. 1474: 5571243.. 5571243: 1: 5571320:
12: 1475.. 1476: 5571482.. 5571483: 2: 5571244:
13: 1477.. 1480: 5571132.. 5571135: 4: 5571484:
14: 1481.. 1481: 5571172.. 5571172: 1: 5571136: last,eof
/usr/lib/locale/locale-archive: 13 extents found
83: 1: 5571242:
8: 1469.. 1469: 5571242.. 5571242: 1: 5571284:
9: 1470.. 1471: 5571280.. 5571281: 2: 5571243:
10: 1472.. 1473: 5571318.. 5571319: 2: 5571282:
11: 1474.. 1474: 5571243.. 5571243: 1: 5571320:
12: 1475.. 1476: 5571482.. 5571483: 2: 5571244:
13: 1477.. 1480: 5571132.. 5571135: 4: 5571484:
14: 1481.. 1481: 5571172.. 5571172: 1: 5571136: last,eof
/usr/lib/locale/locale-archive: 13 extents found
Note: last line tells 13 extents, I see index ZERO up to 14 = 15 extents
adding up the length column gets 1472 blocks.
dividing the byte value by 4096 gives 1481.9883
1482 blocks times 8 gives 11856 blocks a 512 Bytes
ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: linux-image-6.8.0-90-generic 6.8.0-90.91~22.04.1
ProcVersionSignature: Ubuntu 6.8.0-90.91~22.04.1-generic 6.8.12
Uname: Linux 6.8.0-90-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.10
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: bernie 1638 F.... wireplumber
/dev/snd/seq: bernie 1636 F.... pipewire
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Mon Jan 5 18:46:13 2026
InstallationDate: Installed on 2022-05-31 (1315 days ago)
InstallationMedia: Ubuntu 22.04 LTS "Jammy Jellyfish" - Release amd64 (20220419)
IwConfig:
lo no wireless extensions.
enp0s25 no wireless extensions.
MachineType: Hewlett-Packard HP EliteBook 8560p
ProcFB: 0 i915drmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.8.0-90-generic
root=UUID=8c4a19fc-3a52-45a8-af0a-5ab87347db3a ro loglevel=5 nosmt noplymouth
security_lockdown_lsm_early lockdown=confidentiality ipv6.disable=1
initcall_blacklist=serial8250_init
RelatedPackageVersions:
linux-restricted-modules-6.8.0-90-generic N/A
linux-backports-modules-6.8.0-90-generic N/A
linux-firmware 20220329.git681281e4-0ubuntu3.40
RfKill:
SourcePackage: linux-hwe-6.8
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/06/2017
dmi.bios.release: 15.101
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68SCF Ver. F.65
dmi.board.name: 1618
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 97.4E
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.ec.firmware.release: 151.78
dmi.modalias:
dmi:bvnHewlett-Packard:bvr68SCFVer.F.65:bd04/06/2017:br15.101:efr151.78:svnHewlett-Packard:pnHPEliteBook8560p:pvrA0001D02:rvnHewlett-Packard:rn1618:rvrKBCVersion97.4E:cvnHewlett-Packard:ct10:cvr:skuLG731EA#ABD:
dmi.product.family: 103C_5336AN
dmi.product.name: HP EliteBook 8560p
dmi.product.sku: LG731EA#ABD
dmi.product.version: A0001D02
dmi.sys.vendor: Hewlett-Packard
** Affects: linux-hwe-6.8 (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug jammy
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/2137491
Title:
syscall statx(2) report wrong value for stx_blocks
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-hwe-6.8/+bug/2137491/+subscriptions
--
ubuntu-bugs mailing list
[email protected]
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
