Andriy Tkachuk
33961142a2
vdev_rebuild() is always called with spa_config_lock held in
RW_WRITER mode. However, when it tries to call dmu_tx_assign()
the latter may hang on dmu_tx_wait() waiting for available txg.
But that available txg may not happen because txg_sync takes
spa_config_lock in order to process the current txg. So we have
a deadlock case here:
- dmu_tx_assign() waits for txg holding spa_config_lock;
- txg_sync waits for spa_config_lock not progressing with txg.
Here are the stacks:
__schedule+0x24e/0x590
schedule+0x69/0x110
cv_wait_common+0xf8/0x130 [spl]
__cv_wait+0x15/0x20 [spl]
dmu_tx_wait+0x8e/0x1e0 [zfs]
dmu_tx_assign+0x49/0x80 [zfs]
vdev_rebuild_initiate+0x39/0xc0 [zfs]
vdev_rebuild+0x84/0x90 [zfs]
spa_vdev_attach+0x305/0x680 [zfs]
zfs_ioc_vdev_attach+0xc7/0xe0 [zfs]
cv_wait_common+0xf8/0x130 [spl]
__cv_wait+0x15/0x20 [spl]
spa_config_enter+0xf9/0x120 [zfs]
spa_sync+0x6d/0x5b0 [zfs]
txg_sync_thread+0x266/0x2f0 [zfs]
The solution is to pass txg returned by spa_vdev_enter(spa)
at the top of spa_vdev_attach() to vdev_rebuild() and call
dmu_tx_create_assigned(txg) which doesn't wait for txg.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Akash B <akash-b@hpe.com>
Reviewed-by: Alek Pinchuk <apinchuk@axcient.com>
Signed-off-by: Andriy Tkachuk <andriy.tkachuk@seagate.com>
Closes #18210
Closes #18258
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.
Official Resources
- Documentation - for using and developing this repo
- ZoL site - Linux release info & links
- Mailing lists
- OpenZFS site - for conference videos and info on other platforms (illumos, OSX, Windows, etc)
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 and Distributions
Linux
Given the wide variety of Linux environments, we prioritize development and testing on stable, supported kernels and distributions.
Kernel (kernel.org)
All longterm kernels from kernel.org are supported. stable kernels are usually supported in the next OpenZFS release.
Supported longterm kernels: 6.18, 6.12, 6.6, 6.1, 5.15, 5.10.
Red Hat Enterprise Linux (RHEL)
All RHEL (and compatible systems: AlmaLinux OS, Rocky Linux, etc) on the full or maintenance support tracks are supported.
Supported RHEL releases: 8.10, 9.7, 10.1.
Ubuntu
All Ubuntu LTS releases are supported.
Supported Ubuntu releases: 24.04 “Noble”, 22.04 “Jammy”.
Debian
All Debian stable and LTS releases are supported.
Supported Debian releases: 13 “Trixie”, 12 “Bookworm”, 11 “Bullseye”.
Other Distributions
Generally, if a distribution is following an LTS kernel, it should work well with OpenZFS.
FreeBSD
All FreeBSD releases receiving security support are supported by OpenZFS.
Supported FreeBSD releases: 15.0, 14.3, 13.5.