[LU-1365] Implement ldiskfs LARGEDIR support for e2fsprogs

• Type: New Feature
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.12.4
• Affects Version/s: Lustre 2.3.0
• Labels: LTS12 e2fsprogs ldiskfs patch
• Story Points: 3
• Assignee: Artem Blagodarenko (Inactive)
• Reporter: Andreas Dilger

Description

This INCOMPAT_LARGEDIR feature allows larger directories to be created in ldiskfs, both with directory sizes over 2GB and and a maximum htree depth of 3 instead of the current limit of 2. These features are needed in order to exceed the current limit of approximately 10M entries in a single directory. The INCOMPAT_LARGEDIR feature was added to ldiskfs as part of the pdirops LU-50 coding, but was not part of that project. As there is currently no mke2fs, e2fsck, or tune2fs support for INCOMPAT_LARGEDIR, this feature is disabled by default when creating a new ldiskfs filesystem as it would otherwise make the filesystem unrecoverable in the case that e2fsck needs to be run on it.

Tasks that need to be completed before INCOMPAT_LARGEDIR can be used:

• add support for the INCOMPAT_LARGEDIR and "large_dir" features to mke2fs/tune2fs
• add conf-sanity.sh test LARGEDIR and 3-level htree for local ldiskfs with 1kB blocksize up to 100k entries with 255-byte names (3-level exceeded at 48k entries). This might be done using a smaller number of hard-linked inodes (nlink_max = 65000), to avoid overhead of accessing and caching a large number of different inodes.
• add parallel-scale.sh test LARGEDIR and >2GB directories with Lustre using 255-byte names and 10M entries (2GB exceeded at 4M entries, 4GB exceeded at 8M entries). This might be done using a smaller number of hard-linked inodes (nlink_max = 65000), to avoid overhead of accessing and caching a large number of different inodes.
• e2fsck support for 3-level htree
• e2fsck support for directories larger than 2GB (using i_size_hi consistently for S_IFDIR() inodes)
• e2fsprogs regression test test for 3-level/2GB+ htree e2fsck, corruptions
• e2fsprogs add LARGEDIR feature to "tests/f_random_corruption"
• port the ext4-large-dir.patch with the INCOMPAT_LARGEDIR features (>2GB, 3-level htree) to the upstream kernel and submit to linux-ext4 list for review
• submit e2fsprogs patches to linux-ext4 list for review
• solicit testing of feature from community
• some time after e2fsprogs is released and available for download, a patch is needed to enable large_dir on new filesystems with mkfs.lustre
• updates to the user manual and release notes to describe how to enable the large_dir feature with tune2fs

Issue Links

• is duplicated by: LU-896 change e2fsprogs to make it allow directories over 2GB
• is duplicated by: LU-7932 Patch e2fsprogs to allow set special flag to FS increase a hash tree levels
• is related to: LU-11915 conf-sanity test 115 is skipped or hangs
• is related to: LU-14345 e2fsck of very large directories is broken
• is related to: LU-14734 enable large_dir on existing MDTs
• is related to: LU-11546 enable large_dir support for MDTs
• is related to: LU-8974 Сhange force_over_256tb lustre mount option to force_over_512tb for ldiskfs
• is related to: LU-50 pdirops patch for ldiskfs

Comments

[Peter Jones]

We usually leave tickets as RESOLVED rather than CLOSED because then the ticket can be updated when needed (if landed to maintenance branches, say) without the extra email generated by having to go through the states REOPEN then RESOLVED then CLOSED again.

[Colin Faber [X] (Inactive)]

should this be closed?

[Peter Jones]

Landed for 2.13

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/33756/
Subject: LU-1365 tests: createmany outputs stat after 2 seconds
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 46125b6d9627d006087dfcc727e2cff0954e78c8

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/22009/
Subject: LU-1365 tests: LARGEDIR and 3-level htree for local ldiskfs
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 8048e216c16fa403da6fa2a755df8f718ab3105d

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/33757/
Subject: LU-1365 utils: allow set block size for ldiskfs backend
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 5f674667bfd1ab9a0e47d9f03f3e7eab37eb8e17

[Artem Blagodarenko (Inactive)]

Test conf_sanity 125 successfully passed on my local environment. It's took 1,5 hours. Full logs are attached to this issue.
Name creation rate didn't reduced dramatically. From 

 total: 60000 link in 119.82 seconds: 500.76 ops/second

in first iteration. To

total: 60000 link in 123.89 seconds: 484.31 ops/second 

I belive previous performance drop could be because we sent full directory name to createmany utility and lookup require more time for large directory. This time createmany acts on the current directory.

[Gerrit Updater]

Andreas Dilger ([e-mail]) merged in patch https://review.whamcloud.com/33813/
Subject: LU-1365 e2fsck: allow to check >2GB sized directory
Project: tools/e2fsprogs
Branch: master-lustre
Current Patch Set:
Commit: c5de396607efa2032bc32f7aa607b38d9e82dc6b

[Gerrit Updater]

Andreas Dilger ([e-mail]) merged in patch https://review.whamcloud.com/33814/
Subject: LU-1365 debugfs: output large directory size
Project: tools/e2fsprogs
Branch: master-lustre
Current Patch Set:
Commit: b3267b9f4f9037b84fa83e1296e7dad508a592ba

[Gerrit Updater]

Artem Blagodarenko ([e-mail]) uploaded a new patch: https://review.whamcloud.com/33814
Subject: LU-1365 debugfs: output large directory size
Project: tools/e2fsprogs
Branch: master-lustre
Current Patch Set: 1
Commit: d598fae184f1abdfd47b8396f21db217238ce220

[Gerrit Updater]

Artem Blagodarenko ([e-mail]) uploaded a new patch: https://review.whamcloud.com/33813
Subject: LU-1365 e2fsck: allow to check >2GB sized directory
Project: tools/e2fsprogs
Branch: master-lustre
Current Patch Set: 1
Commit: 7e77372d97aad810b651e680220d8168cd5bf54c