This repository has been archived by the owner on Nov 7, 2019. It is now read-only.
9880 Race in ZFS parallel mount #700
Closed
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
citrus-it
force-pushed
the
oz_parallel
branch
from
7b87e7f
to
70468f0
Compare
jasonbking
suggested changes
Oct 10, 2018
citrus-it
force-pushed
the
oz_parallel
branch
from
70468f0
to
707f913
Compare
jasonbking
approved these changes
Oct 10, 2018
|
@sebroy could you take a look if you have time? |
|
@sebroy - it would be great if you could have a look please. I'm hoping to get this integrated in time for the next OmniOS and OpenIndiana release/snapshot - if necessary I can take it through review and RTI myself on the illumos side. TIA. |
sebroy
suggested changes
Oct 17, 2018
sebroy
approved these changes
Oct 17, 2018
|
Shall I submit this for RTI? I know that OpenIndiana want it too before preparing their October snapshot. |
|
@citrus-it sure, you can RTI this. |
|
Sent for RTI |
|
Thanks. I can approve if nobody else does in the next day or so. |
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There is a race condition in the ZFS parallel mount code which shows up if you have zoned datasets with the same mountpoint as those in the global zone. The code makes the incorrect assumption that mount points are globally unique. This results in mount failures during boot or pool import.
Take the following set of filesystems which have been sorted by mountpoint by the existing code - mountpoints followed by the dataset in brackets. The letters at the left are my annotations.
With this set of filesystems,
zfs_foreach_mountpoint()will create tasks a-h, task g will create A-D and D will create s-z. The problem is that, for example, t can run before B.The fix I've gone for at the moment is to change the sort so that filesystems with the
zonedattribute are sorted to the bottom. In the global zone, that results in the expected sorted list of filesystems and has the additional benefit that we can stop creating tasks once we see a zoned filesystem in the list. In a non-global zone, only the delegated filesystems are seen so the list is just traversed as normal.