dstripe: use Lustre layout swap to keep same inode
Nobody has claimed this yet.
- Dominant language
- C
- Stars
- 200
- Forks
- 85
- Avg merge
- 3d 21h
- Merged PRs (30d)
- 2
Description
Suggestion from @adilger
Even better would be to use the layout swap functionality (which has existed since Lustre 2.5), so that the visible inode doesn't change, and applications that have the file open for read are unaffected by the restriping. See lustre/utils/lfs.c::migrate_block() and migrate_nonblock() for how to verify that the file has not been modified during copy and then do the layout swap.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the dstripe restriping path and compare it with lustre/utils/lfs.c::migrate_block() and migrate_nonblock(). Follow how those functions verify that a file was not modified during copying and perform the layout swap. Done means restriping preserves the visible inode and does not disrupt applications reading the open file.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- c
- Domain
- operating-systems, performance
- Issue type
- Feature
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100