Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes.

This bring huge amount of changes, I'll enumerate only user-visible changes:

- Delegated Administration

	Allows regular users to perform ZFS operations, like file system
	creation, snapshot creation, etc.

- L2ARC

	Level 2 cache for ZFS - allows to use additional disks for cache.
	Huge performance improvements mostly for random read of mostly
	static content.

- slog

	Allow to use additional disks for ZFS Intent Log to speed up
	operations like fsync(2).

- vfs.zfs.super_owner

	Allows regular users to perform privileged operations on files stored
	on ZFS file systems owned by him. Very careful with this one.

- chflags(2)

	Not all the flags are supported. This still needs work.

- ZFSBoot

	Support to boot off of ZFS pool. Not finished, AFAIK.

	Submitted by:	dfr

- Snapshot properties

- New failure modes

	Before if write requested failed, system paniced. Now one
	can select from one of three failure modes:
	- panic - panic on write error
	- wait - wait for disk to reappear
	- continue - serve read requests if possible, block write requests

- Refquota, refreservation properties

	Just quota and reservation properties, but don't count space consumed
	by children file systems, clones and snapshots.

- Sparse volumes

	ZVOLs that don't reserve space in the pool.

- External attributes

	Compatible with extattr(2).

- NFSv4-ACLs

	Not sure about the status, might not be complete yet.

	Submitted by:	trasz

- Creation-time properties

- Regression tests for zpool(8) command.

Obtained from:	OpenSolaris

1 files changed, 22 insertions, 9 deletions

diff --git a/sys/kern/vfs_lookup.c b/sys/kern/vfs_lookup.c
index c3e2e80..06682d5 100644
--- a/sys/kern/vfs_lookup.c
+++ b/sys/kern/vfs_lookup.c
@@ -189,14 +189,21 @@ namei(struct nameidata *ndp)
 	ndp->ni_rootdir = fdp->fd_rdir;
 	ndp->ni_topdir = fdp->fd_jdir;
 
-	if (cnp->cn_pnbuf[0] != '/' && ndp->ni_dirfd != AT_FDCWD) {
-		error = fgetvp(td, ndp->ni_dirfd, &dp);
-		FILEDESC_SUNLOCK(fdp);
-		if (error == 0 && dp->v_type != VDIR) {
-			vfslocked = VFS_LOCK_GIANT(dp->v_mount);
-			vrele(dp);
-			VFS_UNLOCK_GIANT(vfslocked);
-			error = ENOTDIR;
+	dp = NULL;
+	if (cnp->cn_pnbuf[0] != '/') {
+		if (ndp->ni_startdir != NULL) {
+			dp = ndp->ni_startdir;
+			error = 0;
+		} else if (ndp->ni_dirfd != AT_FDCWD)
+			error = fgetvp(td, ndp->ni_dirfd, &dp);
+		if (error != 0 || dp != NULL) {
+			FILEDESC_SUNLOCK(fdp);
+			if (error == 0 && dp->v_type != VDIR) {
+				vfslocked = VFS_LOCK_GIANT(dp->v_mount);
+				vrele(dp);
+				VFS_UNLOCK_GIANT(vfslocked);
+				error = ENOTDIR;
+			}
 		}
 		if (error) {
 			uma_zfree(namei_zone, cnp->cn_pnbuf);
@@ -206,10 +213,16 @@ namei(struct nameidata *ndp)
 #endif
 			return (error);
 		}
-	} else {
+	}
+	if (dp == NULL) {
 		dp = fdp->fd_cdir;
 		VREF(dp);
 		FILEDESC_SUNLOCK(fdp);
+		if (ndp->ni_startdir != NULL) {
+			vfslocked = VFS_LOCK_GIANT(ndp->ni_startdir->v_mount);
+			vrele(ndp->ni_startdir);
+			VFS_UNLOCK_GIANT(vfslocked);
+		}
 	}
 	vfslocked = VFS_LOCK_GIANT(dp->v_mount);
 	for (;;) {