Add .zfs control directory

Add support for the .zfs control directory.  This was accomplished
by leveraging as much of the existing ZFS infrastructure as posible
and updating it for Linux as required.  The bulk of the core
functionality is now all there with the following limitations.

*) The .zfs/snapshot directory automount support requires a 2.6.37
   or newer kernel.  The exception is RHEL6.2 which has backported
   the d_automount patches.

*) Creating/destroying/renaming snapshots with mkdir/rmdir/mv
   in the .zfs/snapshot directory works as expected.  However,
   this functionality is only available to root until zfs
   delegations are finished.

      * mkdir - create a snapshot
      * rmdir - destroy a snapshot
      * mv    - rename a snapshot

The following issues are known defeciences, but we expect them to
be addressed by future commits.

*) Add automount support for kernels older the 2.6.37.  This should
   be possible using follow_link() which is what Linux did before.

*) Accessing the .zfs/snapshot directory via NFS is not yet possible.
   The majority of the ground work for this is complete.  However,
   finishing this work will require resolving some lingering
   integration issues with the Linux NFS kernel server.

*) The .zfs/shares directory exists but no futher smb functionality
   has yet been implemented.

Contributions-by: Rohan Puri <[email protected]>
Contributiobs-by: Andrew Barnes <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #173

12 files changed, 12 insertions, 0 deletions

diff --git a/lib/libspl/Makefile.in b/lib/libspl/Makefile.in
index 15c672074..2f94b5db6 100644
--- a/lib/libspl/Makefile.in
+++ b/lib/libspl/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libspl
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/asm-generic/Makefile.in b/lib/libspl/asm-generic/Makefile.in
index 6ad997114..66ec77b00 100644
--- a/lib/libspl/asm-generic/Makefile.in
+++ b/lib/libspl/asm-generic/Makefile.in
@@ -40,6 +40,7 @@ subdir = lib/libspl/asm-generic
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/asm-i386/Makefile.in b/lib/libspl/asm-i386/Makefile.in
index e68762c87..4c9f37fd3 100644
--- a/lib/libspl/asm-i386/Makefile.in
+++ b/lib/libspl/asm-i386/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(noinst_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/asm-x86_64/Makefile.in b/lib/libspl/asm-x86_64/Makefile.in
index 6b7f4beca..845e2ab90 100644
--- a/lib/libspl/asm-x86_64/Makefile.in
+++ b/lib/libspl/asm-x86_64/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(noinst_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/include/Makefile.in b/lib/libspl/include/Makefile.in
index 480b998be..d9f694485 100644
--- a/lib/libspl/include/Makefile.in
+++ b/lib/libspl/include/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(libspl_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/include/ia32/Makefile.in b/lib/libspl/include/ia32/Makefile.in
index 634415864..abb9a7b24 100644
--- a/lib/libspl/include/ia32/Makefile.in
+++ b/lib/libspl/include/ia32/Makefile.in
@@ -39,6 +39,7 @@ DIST_COMMON = $(srcdir)/Makefile.am $(srcdir)/Makefile.in
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/include/ia32/sys/Makefile.in b/lib/libspl/include/ia32/sys/Makefile.in
index c00dc4dce..a7e3f3cd9 100644
--- a/lib/libspl/include/ia32/sys/Makefile.in
+++ b/lib/libspl/include/ia32/sys/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(libspl_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/include/rpc/Makefile.in b/lib/libspl/include/rpc/Makefile.in
index 3513cb88e..6c3174da9 100644
--- a/lib/libspl/include/rpc/Makefile.in
+++ b/lib/libspl/include/rpc/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(libspl_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/include/sys/Makefile.in b/lib/libspl/include/sys/Makefile.in
index c02b3ea75..b226c8d4b 100644
--- a/lib/libspl/include/sys/Makefile.in
+++ b/lib/libspl/include/sys/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(libspl_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/include/sys/dktp/Makefile.in b/lib/libspl/include/sys/dktp/Makefile.in
index cadff828c..aa63471b7 100644
--- a/lib/libspl/include/sys/dktp/Makefile.in
+++ b/lib/libspl/include/sys/dktp/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(libspl_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/include/sys/sysevent/Makefile.in b/lib/libspl/include/sys/sysevent/Makefile.in
index 3e5f21946..29861385d 100644
--- a/lib/libspl/include/sys/sysevent/Makefile.in
+++ b/lib/libspl/include/sys/sysevent/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(libspl_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \
diff --git a/lib/libspl/include/util/Makefile.in b/lib/libspl/include/util/Makefile.in
index 3d49a92df..bb71a90d6 100644
--- a/lib/libspl/include/util/Makefile.in
+++ b/lib/libspl/include/util/Makefile.in
@@ -41,6 +41,7 @@ DIST_COMMON = $(libspl_HEADERS) $(srcdir)/Makefile.am \
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps =  \
 	$(top_srcdir)/config/always-no-unused-but-set-variable.m4 \
+	$(top_srcdir)/config/kernel-automount.m4 \
 	$(top_srcdir)/config/kernel-bdev-block-device-operations.m4 \
 	$(top_srcdir)/config/kernel-bdev-logical-size.m4 \
 	$(top_srcdir)/config/kernel-bdi-setup-and-register.m4 \