Richard Yao 7809eb8b65 ztest: Switch to LWP rwlock interface ... ztest is intended to subject the ZFS code in userland to stress that it should be able to withstand. Any failures that occur when running it are failures that likely would occur inside the kernel. However, being in userland, it is much easier to debug them. In practice, this prevents a large number of problems from reaching production code. A design decision was made by the original authors of ztest to make a distinction between userland locking primitives and kernel locking primitives. The ztest code itself calls userland locking primitives while the kernel code being run in userland will call emulated kernel locking primitives that wrap the userland locking primitives. When ztest was first ported to Linux, a decision was made to use the emulated kernel interfaces everywhere. In effect, the userland rw_rdlock()/rw_wrlock() became the kernel rw_enter() and and the userland rw_unlock() became the kernel rw_exit(). This caused a regression because of an assertion in rw_enter() to catch recursive locking. That is permitted in userland, but not in the kernel. Consequently, the ztest code itself does recursive read locking. The use of the emulated kernel interfaces consequently caused the following failure: ztest: ../../lib/libzpool/kernel.c:384: Assertion `rwlp->rw_owner != zk_thread_current() (0x1c87150 != 0x1c87150)' failed. That occurs because ztest_dmu_objset_create_destroy() will take a read lock and call ztest_dmu_object_alloc_free(). That will call ztest_io(), which will take a readlock only when asked to do ZTEST_IO_REWRITE. This triggered the assertion. The pthreads rwlock interface was based on the LWP rwlock interface implemented in Illumos libc. Luckily enough, the subset used by ztest is almost identical, so we can solve this problem by switching to the LWP thread rwlock interface in ztest. This eliminates a point of divergence with Illumos and should make code sharing slightly easier. Signed-off-by: Richard Yao <ryao@gentoo.org> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Closes #1970		2014-05-01 15:53:58 -07:00
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.gitignore	Add .gitignore files to exclude build products	2010-01-08 11:35:17 -08:00
Makefile.am	Add missing libzfs_core to Makefiles	2013-11-20 15:44:15 -08:00
ztest.c	ztest: Switch to LWP rwlock interface	2014-05-01 15:53:58 -07:00