Use a dedicated taskq for vdev_file

Originally, vdev_file used system_taskq. This would cause a deadlock,
especially on system with few CPUs. The reason is that the prefetcher
threads, which are on system_taskq, will sometimes be blocked waiting
for I/O to finish. If the prefetcher threads consume all the tasks in
system_taskq, the I/O cannot be served and thus results in a deadlock.

We fix this by creating a dedicated vdev_file_taskq for vdev_file I/O.

Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2270
Handle ZPOOL_STATUS_HOSTID_MISMATCH in zpool status

Verbatim imports can cause hostid mismatches, but things otherwise work. `zpool
status` does not handle this and will fail when assertions are enabled:

```
zpool: ../../cmd/zpool/zpool_main.c:4418: status_callback: Assertion `reason == ZPOOL_STATUS_OK' failed.

Program received signal SIGABRT, Aborted.
```

Lets instead add a case to display an informative message such as this:

```
  pool: rpool
 state: ONLINE
status: Mismatch between pool hostid and system hostid on imported pool.
        This pool was previously imported into a system with a different hostid,
        and then was verbatim imported into this system.
action: Export this pool on all systems on which it is imported.
        Then import it to correct the mismatch.
   see: http://zfsonlinux.org/msg/ZFS-8000-EY
  scan: scrub repaired 0 in 0h8m with 0 errors on Thu Apr 17 19:43:57 2014
config:

        NAME        STATE     READ WRITE CKSUM
        rpool       ONLINE       0     0     0
          sda       ONLINE       0     0     0

errors: No known data errors
```

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2342
Allow for lock-free reading zfsdev_state_list.

Restructure the zfsdev_state_list to allow for lock-free reading by
converting to a simple singly-linked list from which items are never
deleted and over which only forward iterations are performed.  It depends
on, among other things, the atomicity of accessing the zs_minor integer
and zs_next pointer.

This fixes a lock inversion in which the zfsdev_state_lock is used by
both the sync task (txg_sync) and indirectly by any user program which
uses /dev/zfs; the zfsdev_release method uses the same lock and then
blocks on the sync task.

The most typical failure scenerio occurs when the sync task is cleaning
up a user hold while various concurrent "zfs" commands are in progress.

Neither Illumos nor Solaris are affected by this issue because they use
DDI interface which provides lock-free reading of device state via the
ddi_get_soft_state() function.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Chunwei Chen <tuxoko@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2301
Calculate header size correctly in sa_find_sizes()

In the case where a variable-sized SA overlaps the spill block pointer and
a new variable-sized SA is being added, the header size was improperly
calculated to include the to-be-moved SA.  This problem could be
reproduced when xattr=sa enabled as follows:

	ln -s $(perl -e 'print "x" x 120') blah
	setfattr -n security.selinux -v blahblah -h blah

The symlink is large enough to interfere with the spill block pointer and
has a typical SA registration as follows (shown in modified "zdb -dddd"
<SA attr layout obj> format):

	[ ... ZPL_DACL_COUNT ZPL_DACL_ACES ZPL_SYMLINK ]

Adding the SA xattr will attempt to extend the registration to:

	[ ... ZPL_DACL_COUNT ZPL_DACL_ACES ZPL_SYMLINK ZPL_DXATTR ]

but since the ZPL_SYMLINK SA interferes with the spill block pointer, it
must also be moved to the spill block which will have a registration of:

	[ ZPL_SYMLINK ZPL_DXATTR ]

This commit updates extra_hdrsize when this condition occurs, allowing
hdrsize to be subsequently decreased appropriately.

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Issue #2214
Issue #2228
Issue #2316
Issue #2343
Honor zfs_nocacheflush for file vdevs

For consistency with disk vdevs honor the zfs_nocacheflush tunable.
This setting is available primarily for debugging and performance
analysis.

Signed-off-by: HC <mmttdebbcc@yahoo.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2336
Added INTEL SSD 530 Series

INTEL SSD 530 Series... SSDSC2BW24

Signed-off-by: John Albietz <inthecloud247@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2184
Omit compiler warning by sticking to RAII

Resolve gcc 4.9.0 20140507 warnings about uninitialized 'ptr' when
using -Wmaybe-uninitialized.  The first two cases appears appear
to be legitimate but not the second two.  In general this is a
good practice so they are all initialized.

Signed-off-by: Marcel Huber <marcelhuberfoo@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2345
Use default slab types

We should not override the default memory type of the kmem cache.  This
was done previously to force certain objects which were slightly over
object size limit cut off in to KMC_KMEM caches for better performance.

The zfsonlinux/spl#356 patch slightly increases the default cut off
from 511 bytes 1024 bytes for x86_64.  This means there is long longer
a need to override the default for the caches.  And since the default
values are now being used the new spl_kmem_cache_slab_limit and
spl_kmem_cache_kmem_limit tunables will apply to all kmem caches.

The following is a list of caches that will be impacted:

                  | object size   | forced type   | default type
----------------- | ------------- | ------------- | --------------
dnode_t           | 936 bytes     | KMC_KMEM      | KMC_KMEM
zio_cache         | 1104 bytes    | *KMC_KMEM     | *KMC_VMEM
zio_link_cache    | 48 bytes      | KMC_KMEM      | KMC_KMEM
zio_vdev_cache    | 131088 bytes  | KMC_VMEM      | KMC_VMEM
zio_buf_512       | 512 bytes     | KMC_KMEM      | KMC_KMEM
zio_data_buf_512  | 512 bytes     | KMC_KMEM      | KMC_KMEM
zio_buf_1024      | 1024 bytes    | KMC_KMEM      | KMC_KMEM
zio_data_buf_1024 | 1024 bytes    | +KMC_VMEM     | +KMC_KMEM

* Cache memory type will change from KMC_KMEM to KMC_VMEM.
+ Cache memory type will change from KMC_VMEM to KMC_KMEM.

This patch removes another slight point of divergence between ZoL
and Illumos.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Prakash Surya <surya1@llnl.gov>
Closes #2337
Restrict release number to META version

When creating packages in a git repository the release number
can be automatically set by 'git describe'.  This normally works
well but if your repository has newer tags which match the form
NAME-VERSION* the release may be incorrectly calculated.  To
prevent this the match patten has been restricted to the contents
of the META file, NAME-VERSION.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fix DKMS package upgrade and packager

Running 'yum upgrade zfs-dkms' package could appear to work properly
and still leave you with no zfs modules installed.  This will occur
when only the zfs release, and not the version, are incremented.
This may be the case for a fast moving zfs-testing repository.

During the upgrade process DKMS will realize that zfs-x.y.z is already
installed and remove it.  DKMS then correctly builds the new modules
for zfs-x.y.z.  However, as a final step when the old zfs-x.y.z-r is
removed the %preun script runs and removes the newly build modules.
To handle this case the %preun script has been updated to only run
when the installed version exactly matches the full spec file version.

This change also updated ChangeLog section based on the DKMS
reference spec file.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Allow building without ACLs

Some kernel definitions were buried inside the #if... #endif logic for
ACLs.  When ACLs are not available these definitions get lost causing
the build to fail.

Signed-off-by: Chris Wedgwood <cw@f00f.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2349
Fix memory leak in zpool_clear_label()

Clang's static analyzer reported a memory leak in zpool_clear_label().
Upon review, it turns out to be right. This should be a very short lived
leak because no daemons use this functionality, but that does not
preclude the possibility of third party daemons that do use it. Lets fix
it to be a good Samaritan.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2330
Remove superfluous statement

Clang's static analyzer reported that the value assigned to pcksum is
never used. That is because we initialize both zc and pcksum to {{ 0 }}
and then do `pcksum = zc;`. That is fairly pointless. However, it has
the effect of generating a false positive in Clang's static analyzer.
Since noise from false positives can obscure real issues, we fix it
anyway.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2330
Move the libraries into separate packages

From day one the various ZFS libraries should have been placed in their
own sub-packages.  Primarily this allows for multiple major versions of
the libraries to be concurrently installed.  It also facilitates a
smaller build environment by minimizing the required dependencies.

The specific changes required to split the libraries from the utilities
are as follows:

* libzpool2, libnvpair1, libuutil1, and libzfs2 packages were added
  and contain the versioned shared libraries.  The Fedora packaging
  guidelines discourage providing static libraries so they are not
  included in the packages.

  http://fedoraproject.org/wiki/Packaging:Guidelines#Packaging_Static_Libraries

* The zfs-devel package was renamed libzfs2-devel and the new package
  obsoletes the old zfs-devel package.   This package includes all
  the required headers for the libzpool2, libnvpair1, libuutil1, and
  libzfs2 libraries and their respective unversioned shared libraries.

  This package should eventually be split in to individual lib*-devel
  packages but it will still take some work to cleanly separate them.
  Therefore the libzfs2-devel package provides the expected lib*-devel
  packages so the all proper dependencies can still be created.

  http://fedoraproject.org/wiki/Packaging:Guidelines#Devel_Packages

* Moved '/sbin/ldconfig' execution from the zfs packge to each of the
  new library packages as described by the packaging guidelines.

  http://fedoraproject.org/wiki/Packaging:Guidelines#Shared_Libraries

* The /usr/share/doc/ files were moved in to the libzfs2-devel package.

* Updated config/deb.am to be aware of the packaging changes.  This
  ensures that 'deb-utils' make target converts all the resulting
  packages generated by the 'rpm-utils' target.

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #2329
Closes: #2341
Issue: #2145
Update spec file to enable systemd for RHEL7

Signed-off-by: Ben Allen <bsallen@alcf.anl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2355
Accept kernel source dir(s) specified by ./configure

This adds ability to set the location of the kernel via defines
when building from the spec files.  This is useful when building
against a kernel installed in a non-standard location.

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1874
Do not export pool to prevent cache from been removed

Signed-off-by: Derek Dai <daiderek@gmail.com>
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2353
Only automatically mount a clone when 'canmount == on'.

According to the man page, "When the noauto option is set, a dataset
can only be mounted and unmounted explicitly. The dataset is not
mounted automatically when the dataset is created or imported ...."

When cloning a dataset the canmount property was not being honored.
This patch adds the required check to achieve the behavior described
in the man page.

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2241
Document the fact that ashift is vdev specific, not a pool global.

Users need to be aware that when adding devices to an existing pool
they may need to override automatically detected ashift value.
This will all depend on the exact hardware they are using.

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #2024
Man page updates for 'zfs share'

* Remove the references to share(1M), unshare(1M) and dfstab(4)
  since they are not applicable to Linux.
* Add the exact exportfs command line used when setting sharenfs=on.

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue: #1641