vdev_id fails to handle complex device topologies

While expanding positional parameters shell requires non-single
digits to be enclosed in braces. When the SAS topology is
non-trivial the number of positional parameters generated internally
by vdev_id script (using set -- ...) easily crosses single digit limit
and vdev_id fails to generate links.

Signed-off-by: Ned Bass <bass6@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1119
Verify --with-linux source directory exists

Previously this check was only performed when ./configure was
attempting to autodetect your kernel source directory.  But we
should also handle the case where --with-linux was provided
and is obviously wrong.  This way we catch the error before
invoking make and compiling the source with an incorrect
autoconf results.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes zfsonlinux/spl#162
Disable page allocation warnings for super block

Due to the slightly increased size of the ZFS super block
caused by 30315d2 there are now allocation warnings.  The
allocation size is still small (just over 8k) and super
blocks are rarely allocated so we suppress the warning.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #1101
Allow GPT+EFI vdevs for root pools

Commit 57a4edd allows the bootfs property to be set on any pool.
However, many of the zpool commands still prevent you from using
EFI labeled devices for the root pool.  For example:

    # zpool attach rpool /dev/sda /dev/sdb
    cannot label 'sdb': EFI labeled devices are not supported on
    root pools. on root devices.

For non-Solaris builds such as Linux disable this error.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1077
Add load_nvlist() error handling

Add the missing error handling to load_nvlist().  There's no good
reason this needs to be fatal.  All callers of load_nvlist() do
correctly handle an error condition and it is preferable that an
error be returned.  This will allow 'zpool import -FX' to safely
attempt to rollback through previous txgs looking for a good one.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1120
Make zpool attach -o ashift=... actually work

Commit df83110856950c8e7b16a7e94cdf42b8531b9cc8 missed update to
getopt() call, while delivering all the rest. This commit adds
"o" to getopt().

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Issue #566
Implemented sharing datasets via SMB using libshare

Add the initial support for the 'smbshare' option using the
existing libshare infrastructure.  Because this implementation
relies on usershares samba version 3.0.23 is required.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #493
Directory xattr znodes hold a reference on their parent

Unlike normal file or directory znodes, an xattr znode is
guaranteed to only have a single parent.  Therefore, we can
take a refernce on that parent if it is provided at create
time and cache it.  Additionally, we take care to cache it
on any subsequent zfs_zaccess() where the parent is provided
as an optimization.

This allows us to avoid needing to do a zfs_zget() when
setting up the SELinux security xattr in the create path.
This is critical because a hash lookup on the directory
will deadlock since it is locked.

The zpl_xattr_security_init() call has also been moved up
to the zpl layer to ensure TXs to create the required
xattrs are performed after the create TX.  Otherwise we
run the risk of deadlocking on the open create TX.

Ideally the security xattr should be fully constructed
before the new inode is unlocked.  However, doing so would
require far more extensive changes to ZFS.

This change may also have the benefitial side effect of
ensuring xattr directory znodes are evicted from the cache
before normal file or directory znodes due to the extra
reference.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #671
vdev_id support for device link aliases

Add a vdev_id feature to map device names based on already defined
udev device links.  To increase the odds that vdev_id will run after
the rules it depends on, increase the vdev.rules rule number from 60
to 69.  With this change, vdev_id now provides functionality analogous
to zpool_id and zpool_layout, paving the way to retire those tools.

A defined alias takes precedence over a topology-derived name, but the
two naming methods can otherwise coexist. For example, one might name
drives in a JBOD with the sas_direct topology while naming an internal
L2ARC device with an alias.

For example, the following lines in vdev_id.conf will result in the
creation of links /dev/disk/by-vdev/{d1,d2}, each pointing to the same
target as the device link specified in the third field.

  #     by-vdev
  #     name     fully qualified or base name of device link
  alias d1       /dev/disk/by-id/wwn-0x5000c5002de3b9ca
  alias d2       wwn-0x5000c5002def789e

Also perform some minor vdev_id cleanup, such as removal of the unused
-s command line option.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #981
Fix 'zpool create' segfault due to bad syntax

Incorrect syntax should never cause a segfault.  In this case
listing multiple comma delimited options after '-o' triggered
the problem.  For example:

  zpool create -o ashift=12,listsnaps=on

This patch resolves the issue by wrapping the calls which use
hdr with a NULL test.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1118
Preserve inode mtime/ctime in .writepage()

When updating a file via mmap()'ed I/O preserve the mtime/ctime
which were updated when the page was made writable by the generic
callback filemap_page_mkwrite().

But more importantly than preserving the exact time add the missing
call to sa_bulk_update().  This ensures that the znode modifications
are written to disk as part of the transaction.  Without this the
inode may mistaken rollback to the previous on-disk znode state.

Additionally, for mmap()'ed znodes explicitly set the atime, mtime,
and ctime on close using the up to date values in the inode.  This
is critical because writepage() may occur after close and on close
we need to ensure the values are correct.

Original-patch-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #764
Revert "Fix unlink/xattr deadlock"

This reverts commit b00131d43ca344d4b205a03ab3eb771a060e5087 which
is no longer needed due to e89260a1c8851ce05ea04b23606ba438b271d890.

This change forces all xattr znodes to hold a reference on their
parent which ensures prune_icache() will never attempt to evict
both the parent and child concurrently.  This effectively prevents
the deadlock condition from ever occuring.

Therefore we can safely revert back to the upstream synchronous
cleanup code.  This is nice because it keeps our code base closer
to upstream and resolves the performance issues introduced by the
original deadlock fix.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #457