e7a99dab2b
The Linux kernel's rwsem's have never provided an interface to allow a reader to be upgraded to a writer. Historically, this functionality has been implemented by a SPL wrapper function. However, this approach depends on internal knowledge of the rw_semaphore and is therefore rather brittle. Since the ZFS code must always be able to fallback to rw_exit() and rw_enter() when an rw_tryupgrade() fails; this functionality isn't critical. Furthermore, the only potentially performance sensitive consumer is dmu_zfetch() and no decrease in performance was observed with this change applied. See the PR comments for additional testing details. Therefore, it is being retired to make the build more robust and to simplify the rwlock implementation. Reviewed-by: Tony Hutter <hutter2@llnl.gov> Reviewed-by: Tomohiro Kusumi <kusumi.tomohiro@gmail.com> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #9029
ZFS on Linux is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community.
Official Resources
Installation
Full documentation for installing ZoL on your favorite Linux distribution can be found at our site.
Contribute & Develop
We have a separate document with contribution guidelines.
Release
ZFS on Linux is released under a CDDL license.
For more details see the NOTICE, LICENSE and COPYRIGHT files; UCRL-CODE-235197
Supported Kernels
- The
METAfile contains the officially recognized supported kernel versions.