[LU-7304] ldiskfs bug when bigalloc feature enabled

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.8.0
• Labels: patch
• Environment: Centos7
• Severity: 3
• Assignee: Yang Sheng
• Reporter: Wang Shilong (Inactive)

Description

When trying to run benchmarking with bigalloc feature, mkfs always failed
and dmesg gave following errors:

LDISKFS-fs error (device sdb): ldiskfs_mb_check_ondisk_bitmap:3611: comm mkdir: on-disk bitmap for group 8corrupted: 0 blocks free in bitmap, 32768 - in gd

Comments

[Joseph Gmitter (Inactive)]

Landed for 2.8

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch http://review.whamcloud.com/16832/
Subject: LU-7304 ldiskfs: fix bug when bigalloc is enabled
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 26adc2e13a877507b483b2d3c3e873fbd13d2596

[Andreas Dilger]

Thank you for the patch. We have never tested Lustre with the bigalloc feature enabled, though in theory it could provide an improvement for OST performance for large file IO, and also to reduce directory block fragmentation.

This will cause small files to consume more space - a whole chunk will be allocated even for very small files. Fortunately, it will still only write 4KB blocks of data rather than the whole chunk.

There may be some assumptions in the osd-ldiskfs code about block sizes and chunks, so it is worthwhile to at least look through the block allocation routines to see if there are any problems. I don't think this will affect statfs() since the filesystem blocksize will still remain at 4KB.

[Joseph Gmitter (Inactive)]

Hi Yang Sheng,
Could you please have a look at this patch?
Thanks.
Joe

[Gerrit Updater]

Wang Shilong ([e-mail]) uploaded a new patch: http://review.whamcloud.com/16832
Subject: LU-7304 ldiskfs: fix bug when bigalloc is enabled
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: fedfa16aebe7c1a424f33adf3ef29b4944f1fcc1