Fix taskq_wait_id()

The existing taskq_wait_id() function can incorrectly block
indefinitely.  Reimplement it more simply using wait_event()
in a similar fashion to taskq_wait_all().

This flaw was uncovered in the context of moving vn_rdwr() to
a taskq.  Previously taskq_wait_id() had no consumers outside
the SPLAT task framework which is why the issue went unnoticed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fix --enable-debug-kmem-tracking option

Re-order initialization in spl_kmem_init to allow for kmem tracing
to work.  The spl_kmem_init function calls taskq_create prior to
initializing the tracking (calling spl_kmem_init_tracking).  Since
taskq_create uses kmem_alloc, NULL dereferences occur because the
global kmem_list hasn't had its next & prev pointers initialized yet.

This commit moves the calls to spl_kmem_init_tracking earlier in the
spl_kmem_init function in order that the subsequent kmem_alloc calls
(by taskq_create) work properly.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #243
Add ASSERT0 and VERIFY0 macros

The Illumos code introduced the ASSERT0 and VERIFY0 macros which
are to be used instead of ASSERT3S(x, ==, 0) and VERIFY3S(x, ==, 0).

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Madhav Suresh <madhav.suresh@delphix.com>
Closes #246
Fix ASSERT0 and VERIFY0 macro typo

Ensure the value is cast to a 'long long' for printing purposes.  The
expectation is that ASSERT0/VERIFY0 are mostly used for validating
return values and thus may commonly be negative.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #246
Copy spl.release.in to kernel dir

Required when compiling ZFS in the kernel.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #253
Add --buildroot option to kmod build

This allows rpmbuild to define buildroot to point to where kernel
data is located.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #242
Linux 3.10 compat: struct vmalloc_info moved

Linux kernel commmit torvalds/linux@db3808c1 moved the
vmalloc_info structure from a private to a public header.
Now that it's available for kernel modules use it.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #257
Linux 3.10 compat: replace PDE()->data with PDE_DATA()

Linux kernel commit torvalds/linux@d9dda78b renamed PDE() to
PDE_DATA().  To handle this detect the prefered interface
and define a PDE_DATA() wrapper for consistency.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #257
Linux 3.10 compat: add missing include of linux/slab.h

Linux kernel commit torvalds/linux@0d01ff2 changes some
includes we were depending on through linux/proc_fs.h.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #257
Linux 3.10 compat: Do not rely on struct proc_dir_entry definition

Linux kernel commit torvalds/linux#59d8053f moved the definition of
struct proc_dir_entry from include/linux/proc_fs.h to the private
header fs/proc/internal.h. The SPL relied on that to map Solaris'
kstat to entries in /proc/spl/kstat.

Since the proc_dir_entry structure is now private the only safe
thing to do is wrap the opaque proc handle with our own structure.
This actually ends up simplify the code and is good because it
moves us away from depending on implementation details of /proc.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #257
Merge branch 'linux-3.10'

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #257
Fix --enable-debug-kmem-tracking option

This code has gotten something stale and no longer builds cleanly
against modern kernels.  The two issues addressed here are as
follows:

* The hlist_*_rcu interfaces in the kernel have been relatively
  unstable.  Since this isn't performance critical code just use
  the long standing hlist_* variants.

* In older kernels the hash_ptr() function takes a 'void *' but
  in newer kernels it expects a 'const void *'.  To silence the
  compiler warnings about this explicitly cast it to a 'void *'.
  The memset function is a similar case but it always expects
  a 'void *'.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #256
Fix bogus kmem leak warning

Commit 5c7a036 correctly relocated the creation of a taskq
and the registraction of the kmem_cache_shrinker after the
initialization of the kmem tracking code.  However, the
cleanup of these structures was not done before the leak
checks in spl_kmem_fini().  This resulted in an incorrect
'kmem leaked' warning even though there was no actual leak.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes zfsonlinux/zfs#1569
Improve build instructions

Make it clear that when building directly from the Git tree
the configure script must be manually generated by running the
autogen.sh script.  This requires that the GNU autotools packages
be installed for your distribution.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes zfsonlinux/zfs#1448
Modify gethrestime to use current_kernel_time()

This allows us to get nanosecond resolution. It also means
we use the same time source as utimensat(now) etc.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #255
Return -1 for generic kmem cache shrinker

It has been observed that it's possible to get in a state where
shrink_slabs() will spin repeated invoking the generic kmem cache
shrinker.  It fails to detect it's not making forward progress
reclaiming from the cache and doesn't give up.  To ensure this
never occurs we unconditionally return -1 after reclaiming what
we can.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Closes zfsonlinux/zfs#1276
Closes zfsonlinux/zfs#1598
Closes zfsonlinux/zfs#1432
Fix KMC_OFFSLAB type caches

Because spl_slab_size() was always returning -ENOSPC for caches of
type KMC_OFFSLAB the cache could never be created.  Additionally
the slab size is rounded up to a page which is what kv_alloc()
expects.  The kv_alloc() code will minimally allocate a page,
in the KMC_OFFSLAB case this could be reduced.

The basic regression tests kmem:slab_small, kmem:slab_large,
and kmem:slab_align regression were updated to test KMC_OFFSLAB.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ying Zhu <casualfisher@gmail.com>
Closes #266
Add kmod repo integration

When the kmod packaging infrastructure was originally added the
dependency on the rpmfusion yum repositories was disabled.  This
was done at the time in favour of getting local builds working.

Now the time has come to conditionally re-enable that functionality
so we can properly provide binary kmod packages.

  ./configure --with-config=srpm
  make SRPM_DEFINE_KMOD='--define="repo rpmfusion"' srpm-kmod
  mock rebuild spl-kmod-x.y.z-r.el6.src.rpm

One nice benefit of finishing this work is that the generic and
fedora spl-kmod spec files can be merged again.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Linux 3.11 compat: Replace num_physpages with totalram_pages

num_physpages was removed by
torvalds/linux@cfa11e08ed39eb28a9eff9a907b20913020c69b5, so lets replace
it with totalram_pages.

This is a bug fix as much as it is a compatibility fix because
num_physpages did not reflect the number of pages actually available to
the kernel:

http://lkml.indiana.edu/hypermail/linux/kernel/0908.2/01001.html

Also, there are known issues with memory calculations when ZFS is in a
Xen dom0. There is a chance that using totalram_pages could resolve
them. This conjecture is untested at the time of writing.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #273
Fix race in spl_kmem_cache_reap_now()

The current code contains a race condition that triggers when bit 2 in
spl.spl_kmem_cache_expire is set, spl_kmem_cache_reap_now() is invoked
and another thread is concurrently accessing its magazine.

spl_kmem_cache_reap_now() currently invokes spl_cache_flush() on each
magazine in the same thread when bit 2 in spl.spl_kmem_cache_expire is
set. This is unsafe because there is one magazine per CPU and the
magazines are lockless, so it is impossible to guarentee that another
CPU is not using its magazine when this function is called.

The solution is to only touch the local CPU's magazine and leave other
CPU's magazines to other CPUs.

Reported-by: DHE
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #274