freebsd-nq/module/spl
Don Brady 186898bbb5 OpenZFS 9425 - channel programs can be interrupted
Problem Statement
=================
ZFS Channel program scripts currently require a timeout, so that hung or
long-running scripts return a timeout error instead of causing ZFS to get
wedged. This limit can currently be set up to 100 million Lua instructions.
Even with a limit in place, it would be desirable to have a sys admin
(support engineer) be able to cancel a script that is taking a long time.

Proposed Solution
=================
Make it possible to abort a channel program by sending an interrupt signal.In
the underlying txg_wait_sync function, switch the cv_wait to a cv_wait_sig to
catch the signal. Once a signal is encountered, the dsl_sync_task function can
install a Lua hook that will get called before the Lua interpreter executes a
new line of code. The dsl_sync_task can resume with a standard txg_wait_sync
call and wait for the txg to complete.  Meanwhile, the hook will abort the
script and indicate that the channel program was canceled. The kernel returns
a EINTR to indicate that the channel program run was canceled.

Porting notes: Added missing return value from cv_wait_sig()

Authored by: Don Brady <don.brady@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com>
Reviewed by: Matt Ahrens <matt@delphix.com>
Reviewed by: Sara Hartse <sara.hartse@delphix.com>
Reviewed by: Brian Behlendorf <behlendorf1@llnl.gov>
Approved by: Robert Mustacchi <rm@joyent.com>
Ported-by: Don Brady <don.brady@delphix.com>
Signed-off-by: Don Brady <don.brady@delphix.com>

OpenZFS-issue: https://www.illumos.org/issues/9425
OpenZFS-commit: https://github.com/illumos/illumos-gate/commit/d0cb1fb926
Closes #8904
2019-06-22 16:51:46 -07:00
..
Makefile.in Fixes for procfs files backed by linked lists 2018-09-26 11:08:12 -07:00
README.md Update build system and packaging 2018-05-29 16:00:33 -07:00
spl-atomic.c Fix cstyle warnings 2018-02-07 11:49:38 -08:00
spl-condvar.c OpenZFS 9425 - channel programs can be interrupted 2019-06-22 16:51:46 -07:00
spl-cred.c Fix cstyle warnings 2018-02-07 11:49:38 -08:00
spl-err.c Correct snprintf() size argument 2019-04-30 19:41:12 -07:00
spl-generic.c Add missing trailing '\n' in printk() messages 2019-05-08 16:43:55 -07:00
spl-kmem-cache.c Fix style of spl_kmem_cache_create() 2019-02-28 17:57:47 -08:00
spl-kmem.c Update build system and packaging 2018-05-29 16:00:33 -07:00
spl-kobj.c Fix cstyle warnings 2018-02-07 11:49:38 -08:00
spl-kstat.c Unbreak build on Linux kernel < 3.10 2019-04-08 14:59:24 -07:00
spl-mutex.c Fix cstyle warnings 2018-02-07 11:49:38 -08:00
spl-proc.c Create /proc/sys/kernel/spl/gitrev with git hash 2018-10-08 21:57:02 -07:00
spl-procfs-list.c Restrict kstats and print real pointers 2019-04-04 18:57:06 -07:00
spl-rwlock.c Linux 5.2 compat: rw_tryupgrade() 2019-05-23 13:46:33 -07:00
spl-taskq.c kernel timer API rework 2019-05-23 14:40:28 -07:00
spl-thread.c Fix more cstyle warnings 2018-02-24 10:05:37 -08:00
spl-tsd.c Remove all spin_is_locked calls 2017-10-30 11:16:56 -07:00
spl-vmem.c Prepare SPL repo to merge with ZFS repo 2018-05-29 14:51:39 -07:00
spl-vnode.c Remove vn_set_fs_pwd()/vn_set_pwd() (no need to be at / during insmod) 2019-05-29 16:18:14 -07:00
spl-xdr.c Update build system and packaging 2018-05-29 16:00:33 -07:00
spl-zlib.c Prepare SPL repo to merge with ZFS repo 2018-05-29 14:51:39 -07:00
THIRDPARTYLICENSE.gplv2 Prepare SPL repo to merge with ZFS repo 2018-05-29 14:51:39 -07:00
THIRDPARTYLICENSE.gplv2.descrip Prepare SPL repo to merge with ZFS repo 2018-05-29 14:51:39 -07:00

The Solaris Porting Layer, SPL, is a Linux kernel module which provides a compatibility layer used by the ZFS on Linux project.

Installation

The latest version of the SPL is maintained as part of this repository. Only when building ZFS version 0.7.x or earlier must an external SPL release be used. These releases can be found at:

Release

The SPL is released under a GPLv2 license.
For more details see the NOTICE and THIRDPARTYLICENSE files; UCRL-CODE-235197