OpenZFS on Linux and FreeBSD
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Tony Hutter 9f4d64e711 Remove spa_namespace_lock from zpool status
This commit removes spa_namespace_lock from the zpool status codepath.
This means that zpool status will not hang if a pool fails while holding
the spa_namespace_lock.

Background:

The spa_namespace_lock was originally meant to protect the
spa_namespace_avl AVL tree.  The spa_namespace_avl tree held the
mappings from pool names to spa_t's.  So if you wanted to lookup the
spa_t for the "tank" pool, you would do an AVL search for "tank" while
holding spa_namespace_lock.

Over time though the spa_namespace_lock was re-purposed to protect other
critical codepaths in the spa subsystem as well.  In many cases we don't
know what the original authors meant to protect with it, or if they
needed it for read-only or read-write protection.  It is simply "too big
and risky to fix properly".

The workaround is to add a new lightweight version of the
spa_namespace_lock called spa_namespace_lite_lock.
spa_namespace_lite_lock only protects the AVL tree, and nothing else.
It can be used for read-only access to the AVL tree without requiring
the spa_namespace_lock.  Calls to spa_lookup_lite() and spa_next_lite()
only need to acquire a reader lock on spa_namespace_lite_lock; they do
not need to also acquire the old spa_namespace_lock.  This allows us to
still run zpool status even if the zfs module has spa_namespace_lock
held.  Note that these AVL tree locks only protect the tree, not the
actual spa_t contents.

Signed-off-by: Tony Hutter <hutter2@llnl.gov>
2024-09-10 14:29:19 -07:00
.github Github workflow: fix typo in `zloop` artifact 2024-08-09 16:49:19 -07:00
cmd spa_prop_get: require caller to supply output nvlist 2024-09-06 08:45:58 -07:00
config build: rename FORCEDEBUG_CPPFLAGS to LIBZPOOL_CPPFLAGS 2024-08-27 12:53:27 -07:00
contrib Add DDT prune command 2024-09-04 14:17:02 -07:00
etc etc/init.d: decide which variant to use at build time. 2024-04-08 16:52:24 -07:00
include Remove spa_namespace_lock from zpool status 2024-09-10 14:29:19 -07:00
lib libzstd: also build with LIBZPOOL_CPPFLAGS 2024-09-09 14:13:27 -07:00
man Add DDT prune command 2024-09-04 14:17:02 -07:00
module Remove spa_namespace_lock from zpool status 2024-09-10 14:29:19 -07:00
rpm Linux 6.10 compat: fix rpm-kmod and builtin 2024-08-15 14:00:18 -07:00
scripts disable automatic dependency tracking for dkms builds 2024-06-13 18:08:49 -07:00
tests Remove spa_namespace_lock from zpool status 2024-09-10 14:29:19 -07:00
udev udev: correctly handle partition #16 and later 2024-03-21 16:38:24 -07:00
.cirrus.yml CI: add FreeBSD build with Cirrus CI 2023-10-06 08:50:26 -07:00
.editorconfig Add an .editorconfig; document git whitespace settings 2020-01-27 13:32:52 -08:00
.gitignore Packaging: Auto-generate changelog during configure (#15528) 2023-11-16 08:58:47 -08:00
.gitmodules .gitmodules: link to openzfs github repository 2021-04-12 09:37:23 -07:00
.mailmap AUTHORS: refresh with recent new contributors (#16362) 2024-07-23 11:47:04 -07:00
AUTHORS AUTHORS: refresh with recent new contributors (#16362) 2024-07-23 11:47:04 -07:00
CODE_OF_CONDUCT.md Documentation corrections 2022-12-22 11:34:28 -08:00
COPYRIGHT Fix typos 2020-06-09 21:24:09 -07:00
LICENSE Update build system and packaging 2018-05-29 16:00:33 -07:00
META Linux 6.10 compat: META 2024-08-21 17:38:06 -07:00
Makefile.am Process `script` directory for all configs 2022-10-27 16:45:14 -07:00
NEWS Fix NEWS file 2020-08-26 21:44:41 -07:00
NOTICE Update build system and packaging 2018-05-29 16:00:33 -07:00
README.md FreeBSD: remove support for FreeBSD < 13.0-RELEASE (#16372) 2024-08-05 16:56:45 -07:00
RELEASES.md Add RELEASES.md file 2021-04-02 16:33:40 -07:00
TEST Remove spa_namespace_lock from zpool status 2024-09-10 14:29:19 -07:00
autogen.sh Ubuntu 22.04 integration: ShellCheck 2022-11-18 11:24:48 -08:00
configure.ac Packaging: Auto-generate changelog during configure (#15528) 2023-11-16 08:58:47 -08:00
copy-builtin copy-builtin: add hooks with sed/>> 2022-05-10 10:17:43 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

README.md

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OpenZFS is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community. This repository contains the code for running OpenZFS on Linux and FreeBSD.

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Official Resources

Installation

Full documentation for installing OpenZFS on your favorite operating system can be found at the Getting Started Page.

Contribute & Develop

We have a separate document with contribution guidelines.

We have a Code of Conduct.

Release

OpenZFS is released under a CDDL license. For more details see the NOTICE, LICENSE and COPYRIGHT files; UCRL-CODE-235197

Supported Kernels

  • The META file contains the officially recognized supported Linux kernel versions.
  • Supported FreeBSD versions are any supported branches and releases starting from 13.0-RELEASE.