Auke Kok 533f309aec Switch to .get_inode_acl() to avoid rcu corruption.
In el9.6, the kernel VFS no longer goes through xattr handlers to
retreive ACLs, but instead calls the FS drivers' .get_{inode_}acl
method.  In the initial compat version we hooked up to .get_acl given
the identical name that was used in the past.

However, this results in caching issues, as was encountered by customers
and exposed in the added test case `basic-acl-consistency`. The result
is that some group ACL entries may appear randomly missing. Dropping
caches may temporarily fix the issue.

The root cause of the issue is that the VFS now has 2 separate paths to
retreive ACL's from the FS driver, and, they have conflicting
implications for caching. `.get_acl` is purely meant for filesystems
like overlay/ecryptfs where no caching should ever go on as they are
fully passthrough only. Filesystems with dentries (i.e. all normal
filesystems should not expose this interface, and instead expose the
.get_inode_acl method. And indeed, in introducing the new interface, the
upstream kernel converts all but a few fs's to use .get_inode_acl().

The functional change in the driver is to detach KC_GET_ACL_DENTRY and
introduce KC_GET_INODE_ACL to handle the new (and required) interface.
KC_SET_ACL_DENTRY is detached due to it being a different changeset in
the kernel and we should separate these for good measure now.

Signed-off-by: Auke Kok <auke.kok@versity.com>
2026-01-30 11:31:43 -08:00
2020-12-07 09:47:12 -08:00
2020-12-07 10:39:20 -08:00
2021-11-05 11:16:57 -07:00
2026-01-15 14:21:53 -08:00

Introduction

scoutfs is a clustered in-kernel Linux filesystem designed to support large archival systems. It features additional interfaces and metadata so that archive agents can perform their maintenance workflows without walking all the files in the namespace. Its cluster support lets deployments add nodes to satisfy archival tier bandwidth targets.

The design goal is to reach file populations in the trillions, with the archival bandwidth to match, while remaining operational and responsive.

Highlights of the design and implementation include:

  • Fully consistent POSIX semantics between nodes
  • Atomic transactions to maintain consistent persistent structures
  • Integrated archival metadata replaces syncing to external databases
  • Dynamic seperation of resources lets nodes write in parallel
  • 64bit throughout; no limits on file or directory sizes or counts
  • Open GPLv2 implementation

Community Mailing List

Please join us on the open scoutfs-devel@scoutfs.org mailing list hosted on Google Groups

Description
No description provided
Readme 8 MiB
Languages
C 87.1%
Shell 9.2%
Roff 2.5%
TeX 0.8%
Makefile 0.4%