Bug 110111
| Summary: | btrfs fi usage reports bogus 16EiB free space | ||
|---|---|---|---|
| Product: | File System | Reporter: | Chris Murphy (bugzilla) |
| Component: | btrfs | Assignee: | Josef Bacik (josef) |
| Status: | RESOLVED CODE_FIX | ||
| Severity: | normal | CC: | dsterba |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 4.4.0-0.rc6.git0.1.fc24.x86_64 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
Regression testing.
With a new mkfs, and mounting the new empty fs, I get this:
[root@f23m ~]# btrfs fi usage /mnt/king
WARNING: MIXED blockgroups not handled
Overall:
Device size: 14.91GiB
Device allocated: 20.00MiB
Device unallocated: 14.89GiB
Device missing: 0.00B
Used: 60.00KiB
Free (estimated): 14.90GiB (min: 14.90GiB)
Data ratio: 1.00
Metadata ratio: 1.00
Global reserve: 4.00MiB (used: 0.00B)
Data+Metadata,single: Size:8.00MiB, Used:28.00KiB
/dev/sdd 8.00MiB
System,single: Size:4.00MiB, Used:4.00KiB
/dev/sdd 4.00MiB
Unallocated:
/dev/sdd 14.90GiB
And then after copying ~837MiB file, the problem still doesn't happen.
[root@f23m ~]# btrfs fi usage /mnt/king/
WARNING: MIXED blockgroups not handled
Overall:
Device size: 14.91GiB
Device allocated: 2.02GiB
Device unallocated: 12.89GiB
Device missing: 0.00B
Used: 1.64GiB
Free (estimated): 13.08GiB (min: 13.08GiB)
Data ratio: 1.00
Metadata ratio: 1.00
Global reserve: 20.00MiB (used: 0.00B)
Data+Metadata,single: Size:1.01GiB, Used:837.86MiB
/dev/sdd 1.01GiB
System,single: Size:4.00MiB, Used:4.00KiB
/dev/sdd 4.00MiB
Unallocated:
/dev/sdd 13.90GiB
However, the Used amount is off by a factor of 2x.
[root@f23m king]# btrfs fi df /mnt/king/
System, single: total=4.00MiB, used=4.00KiB
Data+Metadata, single: total=1.01GiB, used=837.86MiB
GlobalReserve, single: total=20.00MiB, used=0.00B
Around 48% used (per conventional df, which matches up reasonably well with btrfs fi df), "fi usage" flips from a sane looking (but still wrong) value to 16.00EiB.
This may be due to the lack of support for mixedbg by 'fi usage'.
Mixed block groups reporting in 'fi usage' should be fixed in devel, queued for 4.4. |
btrfs-progs-4.3.1-1.fc23.x86_64 1. Used f3write to test a USB stick formatted with mkfs.btrfs -M, this fills the entire device. 2. btrfs fi usage <mp> Actual results: [root@f23m ~]# btrfs fi usage /mnt/king WARNING: MIXED blockgroups not handled Overall: Device size: 14.91GiB Device allocated: 29.82GiB Device unallocated: 16.00EiB Device missing: 0.00B Used: 29.23GiB Free (estimated): 16.00EiB (min: 16.00EiB) !!!!!!! Data ratio: 1.00 Metadata ratio: 1.00 Global reserve: 300.00MiB (used: 0.00B) Data+Metadata,single: Size:14.91GiB, Used:14.62GiB /dev/sdd 14.91GiB System,single: Size:4.00MiB, Used:4.00KiB /dev/sdd 4.00MiB Unallocated: /dev/sdd 0.00B [root@f23m ~]# df -h Filesystem Size Used Avail Use% Mounted on [..snip...] /dev/sdd 15G 15G 301M 99% /mnt/king [root@f23m ~]# btrfs fi df /mnt/king/ System, single: total=4.00MiB, used=4.00KiB Data+Metadata, single: total=14.91GiB, used=14.62GiB GlobalReserve, single: total=300.00MiB, used=0.00B [root@f23m ~]# btrfs fi show /mnt/king Label: none uuid: 8040969d-6809-4c7a-9126-afbbb127a719 Total devices 1 FS bytes used 14.62GiB devid 1 size 14.91GiB used 14.91GiB path /dev/sdd Expected: Should report in the vicinity of 300MiB free, not 16.00EiB.