Commit Graph

445 Commits

Author SHA1 Message Date
Mark Johnston
ee765c2d34 Don't try to use the 32-bit drti.o unless the data model is explicitly set
to ILP32. Otherwise dtrace -G will attempt to use it on amd64 if it can't
determine which data model to use, which happens when -64 is omitted and
no object files are provided, e.g. with

# dtrace -G -n BEGIN

This would result in a linker error, but now works properly.

Also remove an unnecessary #ifdef.

MFC after:	2 weeks
2013-11-09 04:38:16 +00:00
Sean Bruno
09d325677d Quiesce warning assigning to void * from const ctf_header_t * by explicity casting
to void * before assignment.

Submitted as Illumos issue 4287
2013-11-04 21:32:07 +00:00
Sean Bruno
538c3c05e7 spelling in comments fixup
Submitted by:		Joerg Sonnenberger <joerg@britannica.bec.de>
2013-11-04 19:32:35 +00:00
Sean Bruno
bf10ab6b9c Quiesce warning regarding %llf which has no effect.
Submitted as illumos issue #4284

Reviewed by:	delphij
2013-11-04 16:15:43 +00:00
Sean Bruno
6392bb4f3f This library uses macros to define fprintf behvavior for several object types
The compiler will see the non-string literal arguments to the fprintf calls and
omit warnings for them. Quiese these warnings in contrib code:

cddl/contrib/opensolaris/lib/libnvpair/libnvpair.c:743:12: warning: format
  string is not a string literal (potentially insecure) [-Wformat-security]
  ARENDER(pctl, nvlist_array, nvl, name, val, nelem);
2013-11-03 21:05:44 +00:00
Mark Johnston
5d76604145 If the initial attempt to open /dev/ksyms fails, kldload the ksyms module
and retry.
2013-10-27 16:18:48 +00:00
Mark Johnston
a10f58d076 Convert the lockstat(1) man page to mdoc and make sure that it gets
installed. Additionally, remove Solaris-specific sections and references,
and replace example outputs with output from lockstat on FreeBSD, since
lockstat's output contains stack traces.

This change also removes some examples that don't seem to work properly on
FreeBSD. The examples should be re-added when lockstat is fixed.

Reported by:	avg
MFC after:	1 week
2013-10-27 16:01:11 +00:00
Steven Hartland
818d321f67 Added support for the 'zfs list -t snap' and 'zfs snap' aliases which are
available under Oracle Solaris 11.

This includes an update to the ZFS(8) man page to reflect all the
available alias (snap, umount, and recv).

Initial changes obtained from ZFS On Linux + fixes for man page and cmd
help:
10b75496bb
cf81b00a73

Obtained from:	https://github.com/zfsonlinux/zfs
MFC after:	2 weeks
Sponsored by:	Multiplay
2013-10-23 18:22:27 +00:00
Mark Johnston
e572bc11ec Add a function, memstr, which can be used to convert a buffer of
null-separated strings to a single string. This can be used to print the
full arguments of a process using execsnoop (from the DTrace toolkit) or
with the following one-liner:

dtrace -n 'syscall::execve:return {trace(curpsinfo->pr_psargs);}'

Note that this relies on the process arguments being cached via the struct
proc, which means that it will not work for argvs longer than
kern.ps_arg_cache_limit. However, the following rather non-portable
script can be used to extract any argv at exec time:

fbt::kern_execve:entry
{
    printf("%s", memstr(args[1]->begin_argv, ' ',
        args[1]->begin_envv - args[1]->begin_argv));
}

The debug.dtrace.memstr_max sysctl limits the maximum argument size to
memstr(). Thanks to Brendan Gregg for helpful comments on freebsd-dtrace.

Tested by:	Fabian Keil (earlier version)
MFC after:	2 weeks
2013-10-16 01:39:26 +00:00
Justin Hibbits
30b318b92f Add fasttrap for PowerPC. This is the last piece of the dtrace/ppc puzzle.
It's incomplete, it doesn't contain full instruction emulation, but it should be
sufficient for most cases.

MFC after:	1 month
2013-10-15 15:00:29 +00:00
Mark Johnston
3f3c4e0b4a Convert the dtrace(1) man page to mdoc and fix up some aspects of it that
don't make sense on FreeBSD. In particular,

- remove the ATTRIBUTES section,
- remove references to the Solaris Dynamic Tracing Guide, except in the
  SEE ALSO section,
- update the description of the -A option for FreeBSD's implementation,
- remove references to Solaris-specific programs and configuration files,
  and replace them with FreeBSD equivalents where possible.

The content has not changed aside from this.

Approved by:	re (joel)
MFC after:	1 week
2013-10-10 03:50:23 +00:00
Robert Millan
8a675a6396 Fix implicit declaration of jail_getid()
Approved by:	re
2013-10-07 14:22:19 +00:00
Mark Johnston
8298c17c6c Add a separate translator for headers passed to the TCP probes in the
input path. These probes get some of the fields in host order, whereas the
output probes get them in network order, so a single translator isn't
enough. This workaround ensures that the problem is essentially invisble
to users: none of the probe arguments or their fields have changed.

Approved by:	re (hrs)
2013-10-02 17:14:12 +00:00
Xin LI
253aa02fc3 MFV r254750:
Add support of Illumos dumps on zvol over RAID-Z.

Note that this only adds the features.  FreeBSD would
still need more work to support dumping on zvols.

Illumos ZFS issues:
  2932 support crash dumps to raidz, etc. pools

MFC after:	1 month
Approved by:	re (ZFS blanket)
2013-09-21 00:17:26 +00:00
Mark Johnston
9feec372db Use the address of the inpcb rather than the tcpcb to identify TCP
connections. This keeps the tcp provider consistent with the other network
providers.

Approved by:	re (delphij)
2013-09-15 21:38:46 +00:00
Xin LI
e8de677c74 MFV r247844 (illumos-gate 13975:ef6409bc370f)
Illumos ZFS issues:
  3582 zfs_delay() should support a variable resolution
  3584 DTrace sdt probes for ZFS txg states

Provide a compatibility shim for Solaris's cv_timedwait_hires
to help aid future porting.

Approved by:	re (ZFS blanket)
2013-09-10 01:46:47 +00:00
Will Andrews
5a5347c3f1 Build all ZFS testing & debugging tools with -g.
These programs and everything using libzpool rely on the embedded asserts to
verify the correctness of operations.  Given that, the core dumps would be
useless without debug symbols.
2013-08-27 04:01:31 +00:00
Pedro F. Giffuni
d69c286983 Merge various CTF fixes from illumos
2942 CTF tools need to handle files which legitimately lack data
2978 ctfconvert still needs to ignore legitimately dataless files on SPARC

Illumos Revisions:	13745:6b3106b4250f
			13754:7231b684c18b

Reference:

https://www.illumos.org/issues/2942
https://www.illumos.org/issues/2978

MFC after:	3 weeks
2013-08-26 22:29:42 +00:00
Mark Johnston
57f6086735 Implement the ip, tcp, and udp DTrace providers. The probe definitions use
dynamic translation so that their arguments match the definitions for
these providers in Solaris and illumos. Thus, existing scripts for these
providers should work unmodified on FreeBSD.

Tested by:	gnn, hiren
MFC after:	1 month
2013-08-25 21:54:41 +00:00
Xin LI
83b6a67e66 MFV r254751:
Don't treat the parameter as a number (pool GUID) when there is
error converting it from string, instead, treat it as the pool
name.

Illumos ZFS issues:
  1765 assert triggered in libzfs_import.c trying to import pool
       name beginning with a number
2013-08-24 00:54:47 +00:00
Xin LI
b333d51d8f MFV r254748:
Fix memory leak in libzfs's iter_dependents_cb().

Illumos ZFS issues:
  4061 libzfs: memory leak in iter_dependents_cb()
2013-08-24 00:29:34 +00:00
Xin LI
cc16dea626 MFV r254746:
To quote original Illumos ticket:

libctf thinks that any ELF file containing more than 65536 sections is
corrupt, because it doesn't understand the SHN_XINDEX magic.

Illumos DTrace issues:
  4005 libctf can't deal with extended sections
2013-08-23 23:58:56 +00:00
Xin LI
3f0164abf3 MFV r254422:
Illumos DTrace issues:
  3089 want ::typedef
  3094 libctf should support removing a dynamic type
  3095 libctf does not validate arrays correctly
  3096 libctf does not validate function types correctly
2013-08-23 23:21:24 +00:00
Justin T. Gibbs
439d30d121 Enhance the ZFS vdev layer to maintain both a logical and a physical
minimum allocation size for devices.  Use this information to
automatically increase ZFS's minimum allocation size for new top-level
vdevs to a value that more closely matches the optimum device
allocation size.

Use GEOM's stripesize attribute, if set, as the physical sector
size of the GEOM.

Calculate the minimum blocksize of each metaslab class.  Use the
calculated value instead of SPA_MINBLOCKSIZE (512b) when determining
the likelyhood of compression yeilding a reduction in physical space
usage.

Report devices with sub-optimal block size configuration in "zpool
status".  Also properly fail attempts to attach devices with a
logical block size greater than 8kB, since this will cause corruption
to ZFS's label area.

Sponsored by:	Spectra Logic Corporaion
MFC after:	2 weeks

Background
==========
Many modern devices use physical allocation units that are much
larger than the minimum logical allocation size accessible by
external commands.  Two prevalent examples of this are 512e disk
drives (512b logical sector, 4K physical sector) and flash devices
(512b logical sector, 4K or larger allocation block size, and 128k
or larger erase block size).  Operations that modify less than the
physical sector size result in a costly read-modify-write or garbage
collection sequence on these devices.

Simply exporting the true physical sector of the device to ZFS would
yield optimal performance, but has two serious drawbacks:

1) Existing pools created with devices that have different logical
   and physical block sizes, but were configured to use the logical
   block size (e.g. because the OS version used for pool construction
   reported the logical block size instead of the physical block
   size) will suddenly find that the vdev allocation size has
   increased.  This can be easily tolerated for active members of
   the array, but ZFS would prevent replacement of a vdev with
   another identical device because it now appears that the smaller
   allocation size required by the pool is not supported by the new
   device.

2) The device's physical block size may be too large to be supported
   by ZFS.  The optimal allocation size for the vdev may be quite
   large.  For example, a RAID controller may export a vdev that
   requires read-modify-write cycles unless accessed using 64k
   aligned/sized requests.  ZFS currently has an 8k minimum block
   size limit.

Reporting both the logical and physical allocation sizes for vdevs
solves these problems.  A device may be used so long as the logical
block size is compatible with the configuration.  By comparing the
logical and physical block sizes, new configurations can be optimized
and administrators can be notified of any existing pools that are
sub-optimal.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/spa.h:
	Add the SPA_ASHIFT constant.  ZFS currently has a hard upper
	limit of 13 (8k) for ashift and this constant is used to
	both document and enforce this limit.

sys/cddl/contrib/opensolaris/uts/common/sys/fs/zfs.h:
	Add the VDEV_AUX_ASHIFT_TOO_BIG error code.

	Add fields for exporting the configured, logical, and
	physical ashift to the vdev_stat_t structure.

	Add VDEV_STAT_VALID() macro which can be used to verify the
	presence of required vdev_stat_t fields in nvlist data.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c:
	Provide a SYSCTL_PROC handler for "max_auto_ashift".  Since
	the limit is only referenced long after boot when a create
	operation occurs, there's no compelling need for it to be
	a boot time configurable tunable.  This also allows the
	validation code for the max_auto_ashift value to be contained
	within the sysctl handler.

	Populate the new fields in the vdev_stat_t structure.

	Fail vdev opens if the vdev reports an ashift larger than
	SPA_MAXASHIFT.

	Propogate vdev_logical_ashift and vdev_physical_ashift between
	child and parent vdevs as is done for vdev_ashift.

	In vdev_open(), restore code that fails opens for devices
	where vdev_ashift grows.  This can only happen now if the
	device's logical ashift grows, which means it really isn't
	safe to use the device.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/vdev_impl.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_file.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_geom.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_mirror.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_missing.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_raidz.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_root.c:
	Update the vdev_open() API so that both logical (what was
	just ashift before) and physical ashift are reported.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/vdev_impl.h:
	Add two new fields, vdev_physical_ashift and vdev_logical_ashift,
	to vdev_t.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_config.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa.c:
	Add vdev_ashift_optimize().  Call it anytime a new top-level
	vdev is allocated.

cddl/contrib/opensolaris/cmd/zpool/zpool_main.c:
	Add text for the VDEV_AUX_ASHIFT_TOO_BIG error.

	For each sub-optimally configured leaf vdev, report configured
	and native block sizes.

cddl/contrib/opensolaris/cmd/zpool/zpool_main.c:
cddl/contrib/opensolaris/lib/libzfs/common/libzfs.h:
cddl/contrib/opensolaris/lib/libzfs/common/libzfs_status.c:
	Introduce a new zpool status: ZPOOL_STATUS_NON_NATIVE_ASHIFT.
	This status is reported on healthy pools containing vdevs
	configured to use a block size smaller than their reported
	physical block size.

cddl/contrib/opensolaris/lib/libzfs/common/libzfs_status.c:
	Update find_vdev_problem() and supporting functions to
	provide the full vdev_stat_t structure to problem checking
	routines, and to allow decent into replacing vdevs.

	Add a vdev_non_native_ashift() validator which is used on
	the full vdev tree to check for ZPOOL_STATUS_NON_NATIVE_ASHIFT.

cddl/contrib/opensolaris/lib/libzpool/common/kernel.c:
cddl/contrib/opensolaris/lib/libzpool/common/sys/zfs_context.h:
	Enhance sysctl userland stubs now that a SYSCTL_PROC handler
	is used in vdev.c.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/metaslab.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/metaslab_impl.h:
	When the group membership of a metaslab class changes (i.e.
	when a vdev is added or removed from a pool), walk the group
	list to determine the smallest block size currently available
	and record this in the metaslab class.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/metaslab.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/metaslab.c:
	Add the metaslab_class_get_minblocksize() accessor.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/zio_compress.h:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio_compress.c:
sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c:
	In zio_compress_data(), take the minimum blocksize as an
	input parameter instead of assuming SPA_MINBLOCKSIZE.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/arc.c:
	In l2arc_compress_buf(), pass SPA_MINBLOCKSIZE as the minimum
	blocksize of the device.  The l2arc code performs has it's own
	code for deciding if compression is worth while, so this
	effectively disables zio_compress_data() from second guessing
	the original decision.

sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:
	In zio_write_bp_init(), use the minimum blocksize of the
	normal metaslab class when compressing data.
2013-08-21 04:10:24 +00:00
Xin LI
2640fb93f5 MFV r254421:
Illumos ZFS issues:
  3996 want a libzfs_core API to rollback to latest snapshot
2013-08-21 00:04:31 +00:00
Rui Paulo
f6ddb56a60 Load the dtraceall module if /dev/dtrace/dtrace doesn't exist.
MFC after:	3 days
2013-08-10 23:17:09 +00:00
Xin LI
43667c1f68 MFV r254079:
Illumos ZFS issues:
  3957 ztest should update the cachefile before killing itself
  3958 multiple scans can lead to partial resilvering
  3959 ddt entries are not always resilvered
  3960 dsl_scan can skip over dedup-ed blocks if
       physical birth != logical birth
  3961 freed gang blocks are not resilvered and can cause pool to suspend
  3962 ztest should print out zfs debug buffer before exiting
2013-08-08 23:38:31 +00:00
Xin LI
9d2f243aa6 MFV r254071:
Fix a regression introduced by fix for Illumos bug #3834.  Quote from
Matthew Ahrens on the Illumos issue:

ztest fails this assertion because ztest_dmu_read_write() does
        dmu_tx_hold_free(tx, bigobj, bigoff, bigsize);
and then
    dmu_object_set_checksum(os, bigobj,
        (enum zio_checksum)ztest_random_dsl_prop(ZFS_PROP_CHECKSUM), tx);

If the region to free is past the end of the file, the DMU assumes that there
will be nothing to do for this object.  However, ztest does set_checksum(),
which must modify the dnode.  The fix is for ztest to also call

    dmu_tx_hold_bonus(tx, bigobj);

so we can account for the dirty data associated with setting the checksum

Illumos ZFS issues:
  3955 ztest failure: assertion refcount_count(&tx->tx_space_written)
         + delta <= tx->tx_space_towrite
2013-08-07 22:21:00 +00:00
Xin LI
4f7b34578b MFV r254070:
Merge vendor bugfix for ZFS test suite that triggers false positives.

Illumos ZFS issues:
  3949 ztest fault injection should avoid resilvering devices
  3950 ztest: deadman fires when we're doing a scan
  3951 ztest hang when running dedup test
  3952 ztest: ztest_reguid test and ztest_fault_inject don't place nice together
2013-08-07 21:16:14 +00:00
Robert Millan
852bec83ed Fix implicit declaration of warnx(). 2013-08-04 16:25:46 +00:00
Xin LI
d637247e1f MFV r253781 + r253871:
Illumos ZFS issues:
  3894 zfs should not allow snapshot of inconsistent dataset

MFC after:	2 weeks
2013-07-30 21:02:09 +00:00
Steven Hartland
b79849e50c MFV r253784:
Fix zfs send -D hang after processing requiring a CTRL+C to interrupt due to
pthread_join prior to fd close.

This was introduced by r251646 (MFV r251644)

Illumos ZFS issue:
  3909 "zfs send -D" does not work

MFC after:	1 day
2013-07-30 20:45:27 +00:00
Pedro F. Giffuni
41840d7587 DTrace: re-apply r249426 now that the underlying issues have been solved.
Merge change from illumos:

3519 DTrace fails to resolve const types from fbt
3520 dtrace internal error -- token type 316 is not a valid D
     compilation token
3521 clean up dtrace unit tests

Illumos Revision:	e98f46c

Reference:
https://www.illumos.org/issues/3519
https://www.illumos.org/issues/3520
https://www.illumos.org/issues/3521

Tested by:	Fabian Keil
Obtained from:	Illumos
MFC after:	1 month
2013-07-28 01:02:17 +00:00
Pedro F. Giffuni
a98ff31738 DTrace: re-merge remainder of r249367 (original from Illumos).
Bring back some important fixes from Illumos:

3022 DTrace: keys should not affect the sort order when sorting by value
3023 it should be possible to dereference dynamic variables
3024 D integer narrowing needs some work

We particularly avoid the LD_NOLAZYLOAD changes that Illumos made
as those don't apply to FreeBSD and were causing problems in
interactive mode.

Illumos Revision:	13758:23432da34147

Reference:

https://www.illumos.org/issues/3022
https://www.illumos.org/issues/3023
https://www.illumos.org/issues/3024

MFC after:	1 month
Tested by:	markj
2013-07-28 00:45:20 +00:00
Mark Johnston
6e660824a8 Use kern_ioctl() rather than ioctl() for testing the FBT provider, since the
latter doesn't exist in FreeBSD. All the tests under fbtprovider pass now.
2013-07-27 21:31:48 +00:00
Pedro F. Giffuni
e75a1c78e0 Style issue in r253661.
Pointed out by:	avg
MFC after:	1 month
2013-07-26 14:37:23 +00:00
Pedro F. Giffuni
c7cdfecc89 Fix a segfault in ctfmerge due to a bug in gcc.
GCC can generate bogus dwarf attributes with DW_AT_byte_size
set to 0xFFFFFFFF.
The issue was originaly detected in NetBSD but it has been
adapted for portability and to avoid compiler warnings.

Reference:
https://www.illumos.org/issues/3776

Obtained from:	NetBSD
MFC after:	1 month
2013-07-26 00:28:19 +00:00
Xin LI
c92bc5e996 Manually merge part of vendor import r238583 from Illumos.
Illumos changeset: 13680:2bd022a765e2
Illumos ZFS issue:

    2671 zpool import should not fail if vdev ashift has increased

MFC after:	3 days
2013-07-18 00:22:42 +00:00
Martin Matuska
566081efdc Fix misleading or remove irrelevant illumos messages and manpage references
in the zfs command.

PR:		bin/178996
Submitted by:	Peter Schaefer <peter.schaefer@wilhelmheinrichs.de>
MFC after:	3 days
2013-07-04 22:26:38 +00:00
Xin LI
e33806a54a MFV r252215:
Restore a previous behavior before r251646, where when destructing
ZFS snapshot, the ioctl would return ENOENT when it hit any of
them in the errlist (the new behavior was only return ENOENT when
all returns error).

Illumos ZFS issues:
  3829 fix for 3740 changed behavior of zfs destroy/hold/release ioctl

MFC after:	1 week
2013-06-25 22:14:32 +00:00
Xin LI
302dc71948 Diff reduction against Illumos, no real change to code itself.
This marks vendor branch revision 252213 as merged, the actual code was
committed in r245479.

MFC after:	1 week
2013-06-25 21:51:52 +00:00
Steven Hartland
b7f3763e6c Fixed ZFS zpool freeze (debug command) not processing due to invalid ioctl call syntax.
MFC after:	1 week
2013-06-21 15:30:46 +00:00
Xin LI
9625321547 MFV r251644:
Poor ZFS send / receive performance due to snapshot
hold / release processing (by smh@)

Illumos ZFS issues:
  3740 Poor ZFS send / receive performance due to snapshot
       hold / release processing

MFC after:      2 weeks
2013-06-12 07:07:06 +00:00
Xin LI
3b245f3ee1 MFV r251624:
txg commit callbacks don't work

Illumos ZFS issues:
  3747 txg commit callbacks don't work

MFC after:      2 weeks
2013-06-11 19:29:31 +00:00
Xin LI
23fe4c8a55 MFV r251623:
zpool create should treat -O mountpoint and -m the same

Illumos ZFS issues:
  3745 zpool create should treat -O mountpoint and -m the same

MFC after:      2 weeks
2013-06-11 19:25:49 +00:00
Xin LI
4acaabea05 MFV r251619:
ZFS needs better comments.

Illumos ZFS issues:
  3741 zfs needs better comments

MFC after:      2 weeks
2013-06-11 19:02:36 +00:00
Mark Johnston
18161786c6 Port the SDT test now that it's possible to create SDT probes that take
seven arguments.

The original test uses Solaris' uadmin system call to trigger the test
probe; this change adds a sysctl to the dtrace_test module and gets the test
program to trigger the test probe via the sysctl handler.

The test is currently failing on amd64 because of some bugs in the way that
probe arguments beyond the first five are obtained - these bugs will be
fixed in a separate change.
2013-06-02 00:33:36 +00:00
Mark Johnston
f9a93b641a Remove a block of code that was not intended to be part of the previous
revision.

X-MFC with:	r250812
2013-05-20 02:10:18 +00:00
Mark Johnston
ba6cafe265 Re-introduce another part of r249367. This commit fixes a register leak in
dt_cg_ptrsize() and generally cleans up some of the error handling around
register allocation.

This change corresponds to part of illumos-gate commit e5803b76927480:
  3025 register leak in D code generation

Reviewed by:	pfg
Obtained from:	illumos
MFC after:	1 month
2013-05-19 17:14:36 +00:00
Mark Johnston
fa0deba90f Convert a couple of helper scripts used to test the ip provider to work on
FreeBSD. In the IPv6 case, try each interface before returning an error;
each IPv6-enabled interface will have a link-local address even if the link
isn't up.

MFC after:	1 week
2013-05-15 22:56:24 +00:00