Create an 'overlay' property

Add a new 'overlay' property (default 'off') that controls whether the
filesystem should be mounted even if the mountpoint is busy or if it
should fail with a 'mountpoint not empty'.

Doing overlay mounts is the default mount behavior on Linux, but not
in ZFS. It have been decided that following the ZFS behavior should
be the default, but this overlay allows for site administrator to
override this decision on a per-dataset basis.

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #2503
Illumos 4976-4984 - metaslab improvements

4976 zfs should only avoid writing to a failing non-redundant top-level vdev
4978 ztest fails in get_metaslab_refcount()
4979 extend free space histogram to device and pool
4980 metaslabs should have a fragmentation metric
4981 remove fragmented ops vector from block allocator
4982 space_map object should proactively upgrade when feature is enabled
4983 need to collect metaslab information via mdb
4984 device selection should use fragmentation metric
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Adam Leventhal <adam.leventhal@delphix.com>
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

References:
  https://www.illumos.org/issues/4976
  https://www.illumos.org/issues/4978
  https://www.illumos.org/issues/4979
  https://www.illumos.org/issues/4980
  https://www.illumos.org/issues/4981
  https://www.illumos.org/issues/4982
  https://www.illumos.org/issues/4983
  https://www.illumos.org/issues/4984
  https://github.com/illumos/illumos-gate/commit/2e4c998

Notes:
    The "zdb -M" option has been re-tasked to display the new metaslab
    fragmentation metric and the new "zdb -I" option is used to control
    the maximum number of in-flight I/Os.

    The new fragmentation metric is derived from the space map histogram
    which has been rolled up to the vdev and pool level and is presented
    to the user via "zpool list".

    Add a number of module parameters related to the new metaslab weighting
    logic.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2595
Don't upgrade a metaslab when the pool is not writable

Illumos 4982 added code to metaslab_fragmentation() to proactively update
space maps when the spacemap_histogram feature is enabled.  This should
only happen when the pool is writeable.

References:
  https://www.illumos.org/issues/4982
  https://github.com/illumos/illumos-gate/commit/2e4c998

Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2595
Drive database update

The Intel DC S3500 and Intel DC S3700 are optimized to handle 4KB
sectors well despite of their 8KB page sizes, so we move them to a new
category for enterprise drives where they will receive ashift=12. They
are joined by the Intel 730 series, which uses the same disk controller,
as well as a San Disk enterprise drive. The drive IDs for these two were
obtained by myself with the drive_id utility. The drive ID for the 240GB
Intel 730 model was extrapolated from the drive ID for the 480GB model.

Lastly, we also add some Western Digital mobile drives.  ryuo in
\#zfsonlinux on freenode obtained "ATA     WDC WD2500BEVT-0" from
running drive_id on his own hardware. The additional drives in that
family were extrapolated from that identifer.

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2601
Illumos 4631 - zvol_get_stats triggering too many reads

4631 zvol_get_stats triggering too many reads

Reviewed by: Adam Leventhal <ahl@delphix.com>
Reviewed by: Sebastien Roy <sebastien.roy@delphix.com>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  https://www.illumos.org/issues/4631
  https://github.com/illumos/illumos-gate/commit/bbfa8ea

Ported-by: Boris Protopopov <bprotopopov@hotmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2612
Closes #2480
Fixed memory leaks in zevent handling

Some nvlist_t could be leaked in error handling paths.
Also make sure cb argument to zfs_zevent_post() cannnot
be NULL.

Signed-off-by: Isaac Huang <he.huang@intel.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2158
2493 change efi_rescan() to wait longer

Change efi_rescan() to loop 10 times instead of 5 on EBUSY and
to sleep at the end of each loop. This helps with some instances
where the kernel does not reload the partition table fast enough
for ZFS to detect.

Signed-off-by: Andrew Hamilton <ahamilto@tjhsst.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2493
Illumos 5034 - ARC's buf_hash_table is too small

5034 ARC's buf_hash_table is too small

Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: Saso Kiselkov <skiselkov.ml@gmail.com>
Reviewed by: Richard Elling <richard.elling@gmail.com>
Approved by: Gordon Ross <gwr@nexenta.com>

References:
  https://www.illumos.org/issues/5034
  https://github.com/illumos/illumos-gate/commit/63e911b

Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2615
Illumos 4970-4974 - extreme rewind enhancements

4970 need controls on i/o issued by zpool import -XF
4971 zpool import -T should accept hex values
4972 zpool import -T implies extreme rewind, and thus a scrub
4973 spa_load_retry retries the same txg
4974 spa_load_verify() reads all data twice
Reviewed by: Christopher Siden <christopher.siden@delphix.com>
Reviewed by: Dan McDonald <danmcd@omniti.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Robert Mustacchi <rm@joyent.com>

References:
  https://www.illumos.org/issues/4970
  https://www.illumos.org/issues/4971
  https://www.illumos.org/issues/4972
  https://www.illumos.org/issues/4973
  https://www.illumos.org/issues/4974
  https://github.com/illumos/illumos-gate/commit/e42d205

Notes:
    This set of patches adds a set of tunable parameters for the
    "extreme rewind" mode of pool import which allows control over
    the traversal performed during such an import.

Ported by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2598
Retire HAVE_IOCTL_* configure checks

The HAVE_IOCTL_* configure checks were originally added for
compatibility with an ancient version of glibc.  This support
and additional complexity is no longer needed and is therefore
being removed.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Closes #585
Add a pkgconfig file

Providing a pkg-config file makes is easy for 3rd party applications
to link against the libzfs libraries.  It also allows the libzfs
developers to modify the list of required libraries and cflags
without breaking existing applications.

The following example illustrates how pkg-config can be used:

cc `pkg-config --cflags --libs libzfs` -o myapp myapp.c

/*
 * myapp.c
 */
void main()
{
	libzfs_handle_t *hdl;

	hdl = libzfs_init();
	if (hdl)
		libzfs_fini(hdl);
}

Signed-off-by: Turbo Fredriksson <turbo@bayour.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes: #585
Add a missing > to AUTHORS

An email address in the AUTHORS file was missing its trailing >.
This patch fixes that typo.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Fix race condition with zed pidfile creation

When the zed is started as a forking daemon (by default),
a race-condition exists where the parent process can terminate before
the pidfile has been created by the grandchild process.  When invoked
as a Type=forking systemd service, this can result in the following:

  systemd[1]: Starting ZFS Event Daemon (zed)...
  systemd[1]: PID file /var/run/zed.pid not readable (yet?) after start.

This commit adds a daemonize pipe to allow the grandchild process to
signal the parent process that initialization is complete (and the
pidfile has been created).  The parent process will wait for this
notification before exiting.

Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2252
Cleanup zed logging

This is a set of minor cleanup changes related to zed logging:
- Remove the program identity prefix from messages written to stderr
  since systemd already prepends this output with the program name.
- Replace the copy of the program identity string with a ptr reference.
- Replace "pid" with "PID" for consistency in comments & strings.
- Rename the zed_log.c struct _ctx component "level" to "priority".
- Add the LOG_PID option for messages written to syslog.

Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #2252
Change startup mode of ZED

Change the startup mode of ZED to non-forking. While systemd can
track processes that detach from the terminal just fine, running
processes in non-forking mode is the preferred mode of operation.

Also remove user/group definitions as root/root is the default.

Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2252
Change delimiter for ZED email scripts

When the ZED_EMAIL_INTERVAL_SECS="3600" option is set in zed.rc
configuration file then notification emails should be rate limited.

Rate limiting is accomplished by maintaining a colon delimited state
file which includes the device name.  Unfortunately there are valid
device names which include a colon and therefore prevent the rate
limiting for working properly.  For this reason the delimiter has
been changed to a semi-colon.

Signed-off-by: louwrentius <louwrentius@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Chris Dunlap <cdunlap@llnl.gov>
Closes #2645
Improve handling of filesystem versions

Change mount code to diagnose filesystem versions that
are not supported by the current implementation.

Change upgrade code to do likewise and refuse to upgrade
a pool if any filesystems on it are a version which is
not supported by the current implementation.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Dan Swartzendruber <dswartz@druber.com>
Closes: #2616
Change the default 'zfs_dedup_prefetch' value to '0'

This gives a huge performance improvement in operations with deduped
datasets especially when the bottleneck is the amount of ram
available for zfs.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2639
Import zfs pools after cryptsetup

The zfs-import-cache.service and zfs-import-scan.service should
should be started after cryptsetup to ensure all LUKS devices have
been opened.

Signed-off-by: alteriks <alteriks@gmail.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1474
Fix invalid locking order in rename operation

This commit should prevent a deadlock on dp_config_rwlock when
running `zfs rename` by ensuring zvol_rename_minors() is not
called under this lock.

Signed-off-by: Stanislav Seletskiy <s.seletskiy@gmail.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Tim Chase <tim@chase2k.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #2652.
Closes #2525.