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

22 files changed, 25 insertions, 0 deletions

diff --git a/lib/Makefile.in b/lib/Makefile.in
index 8d57296c6..f40801f66 100644
--- a/lib/Makefile.in
+++ b/lib/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/libavl/Makefile.in b/lib/libavl/Makefile.in
index 8c2be9a28..5e31cc51a 100644
--- a/lib/libavl/Makefile.in
+++ b/lib/libavl/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libavl
 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/libefi/Makefile.in b/lib/libefi/Makefile.in
index 4f954417b..a2f425530 100644
--- a/lib/libefi/Makefile.in
+++ b/lib/libefi/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libefi
 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/libnvpair/Makefile.in b/lib/libnvpair/Makefile.in
index c736a500a..773278483 100644
--- a/lib/libnvpair/Makefile.in
+++ b/lib/libnvpair/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libnvpair
 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/libshare/Makefile.in b/lib/libshare/Makefile.in
index 65133e1bf..e1c1a2ce2 100644
--- a/lib/libshare/Makefile.in
+++ b/lib/libshare/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libshare
 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/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 \
diff --git a/lib/libunicode/Makefile.in b/lib/libunicode/Makefile.in
index d05c40a35..0b99b01a9 100644
--- a/lib/libunicode/Makefile.in
+++ b/lib/libunicode/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libunicode
 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/libuutil/Makefile.in b/lib/libuutil/Makefile.in
index 4aca16091..5e87e0114 100644
--- a/lib/libuutil/Makefile.in
+++ b/lib/libuutil/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libuutil
 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/libzfs/Makefile.in b/lib/libzfs/Makefile.in
index 720cf0729..5fc0ed98e 100644
--- a/lib/libzfs/Makefile.in
+++ b/lib/libzfs/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libzfs
 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/libzpool/Makefile.am b/lib/libzpool/Makefile.am
index d445d340d..cbe3acd34 100644
--- a/lib/libzpool/Makefile.am
+++ b/lib/libzpool/Makefile.am
@@ -97,6 +97,7 @@ libzpool_la_LDFLAGS = -pthread -version-info 1:1:0
 EXTRA_DIST = \
 	$(top_srcdir)/module/zfs/vdev_disk.c \
 	$(top_srcdir)/module/zfs/zfs_acl.c \
+	$(top_srcdir)/module/zfs/zfs_ctldir.c \
 	$(top_srcdir)/module/zfs/zfs_dir.c \
 	$(top_srcdir)/module/zfs/zfs_ioctl.c \
 	$(top_srcdir)/module/zfs/zfs_log.c \
@@ -105,6 +106,7 @@ EXTRA_DIST = \
 	$(top_srcdir)/module/zfs/zfs_rlock.c \
 	$(top_srcdir)/module/zfs/zfs_vfsops.c \
 	$(top_srcdir)/module/zfs/zfs_vnops.c \
+	$(top_srcdir)/module/zfs/zpl_ctldir.c \
 	$(top_srcdir)/module/zfs/zpl_export.c \
 	$(top_srcdir)/module/zfs/zpl_file.c \
 	$(top_srcdir)/module/zfs/zpl_inode.c \
diff --git a/lib/libzpool/Makefile.in b/lib/libzpool/Makefile.in
index 67130c315..d357fdd9e 100644
--- a/lib/libzpool/Makefile.in
+++ b/lib/libzpool/Makefile.in
@@ -41,6 +41,7 @@ subdir = lib/libzpool
 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 \
@@ -455,6 +456,7 @@ libzpool_la_LDFLAGS = -pthread -version-info 1:1:0
 EXTRA_DIST = \
 	$(top_srcdir)/module/zfs/vdev_disk.c \
 	$(top_srcdir)/module/zfs/zfs_acl.c \
+	$(top_srcdir)/module/zfs/zfs_ctldir.c \
 	$(top_srcdir)/module/zfs/zfs_dir.c \
 	$(top_srcdir)/module/zfs/zfs_ioctl.c \
 	$(top_srcdir)/module/zfs/zfs_log.c \
@@ -463,6 +465,7 @@ EXTRA_DIST = \
 	$(top_srcdir)/module/zfs/zfs_rlock.c \
 	$(top_srcdir)/module/zfs/zfs_vfsops.c \
 	$(top_srcdir)/module/zfs/zfs_vnops.c \
+	$(top_srcdir)/module/zfs/zpl_ctldir.c \
 	$(top_srcdir)/module/zfs/zpl_export.c \
 	$(top_srcdir)/module/zfs/zpl_file.c \
 	$(top_srcdir)/module/zfs/zpl_inode.c \