[LU-12125] Allow parallel rename of regular files

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.15.0
• Assignee: Andreas Dilger
• Reporter: Andreas Dilger

Description

In theory it should be possible to relax renaming rules and allow parallel renaming of regular (or non-directory) files.

• the easiest and most common case would be rename of files within the same parent directory, like "mv foo foo.old" where we would only need to lock the DLM resources of the source and target name hashes
• the next case would be to allow rename of files between directories

Probably the easiest is to order such locks by DLM resource (FID+hash) to avoid deadlocks between multiple threads doing renames. For directory renames, they still need to be serialized by the BFL and also take the name hash locks in the source and target dirs to avoid conflict with regular file renames. In theory it would also be possible to allow concurrent rename of directories within the same parent, but that could be done in a separate step.

For renames across shards within a single DNE striped directory they would be treated as renames across directories.

Issue Links

• is related to: LU-15913 rename stress test leads to REMOTE_PARENT_DIR corruption
• is related to: LU-15285 same dir rename deadlock
• is related to: LU-18843 allow parallel rename inside a single directory
• is related to: LU-17426 parallel cross-directory rename of regular files on single MDT
• is related to: LU-12037 Possible DNE issue leading to hung filesystem
• is related to: LU-6864 DNE3: Support multiple modify RPCs in flight for MDT-MDT connection

Comments

[Peter Jones]

Looks like everything has landed for 2.15

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/41231/
Subject: LU-12125 tests: allow racer to specify extra tasks
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: fe2663f18e50023ad5cfe5e07b695378dd27a68e

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/41230/
Subject: LU-12125 mds: allow parallel directory rename
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 90979ab390a72a084f6a77cf7fdc29a4329adb41

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/41186/
Subject: LU-12125 mds: allow parallel regular file rename
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: d76cc65d5d68ed3e04bfbd9b7527f64ab0ee0ca7

[Andreas Dilger]

Further improvements in this area beyond the patches already pushed for same-dir rename operations:

• instead of locking whole parent directory, just lock parent FID+source/target hash to allow parallel file (or directory) rename within a single directory
• allow rename between shards of a striped directory, given that we know source and target shards are not child/ancestor of each other (though there would still need to ordering for locking of individual shards)
• allow regular file rename between different source/target directories, which will need to get a fixed locking order to avoid deadlocks. That code already exists, so may be "only" a matter of dropping the BFL once the source/target are locked. With only regular file rename, there is no strong requirement to know the parent/child relationship of the parent directories, but the consistent locking order is still required to avoid AB/BA deadlocks with other concurrent operations.

I think the benefit of allowing arbitrary parallel directory rename is pretty small, and probably not worthwhile pursuing in the context of this ticket.

[Gerrit Updater]

Oleg Drokin ([e-mail]) merged in patch https://review.whamcloud.com/41184/
Subject: LU-12125 llite: send file mode with rename RPC
Project: fs/lustre-release
Branch: master
Current Patch Set:
Commit: 47576dc68cd90068cd5cbd5c889f04531fe6e682

[Gerrit Updater]

Andreas Dilger ([e-mail]) uploaded a new patch: https://review.whamcloud.com/41231
Subject: LU-12125 tests: allow racer to specify extra tasks
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 4a12916a0375d97fa67bdcdcf860fcf9b88f4192

[Gerrit Updater]

Andreas Dilger ([e-mail]) uploaded a new patch: https://review.whamcloud.com/41230
Subject: LU-12125 mds: allow parallel directory rename
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 8f50962fb02463d620163f9444a430ceca693368

[Gerrit Updater]

Andreas Dilger ([e-mail]) uploaded a new patch: https://review.whamcloud.com/41229
Subject: LU-12125 mds: allow parallel directory rename
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: 8ba0a64c75dbc69bf9de774b67a7e49419f3ba7d

[Gerrit Updater]

Andreas Dilger ([e-mail]) uploaded a new patch: https://review.whamcloud.com/41186
Subject: LU-12125 mds: allow parallel regular file rename
Project: fs/lustre-release
Branch: master
Current Patch Set: 1
Commit: bc1e773b4364dde14df17645dd4d27b1143d1ccf