lvmlockd: idm: Introduce new locking scheme

Alongside the existed locking schemes of DLM and sanlock, this patch is
to introduce new locking scheme: In-Drive-Mutex (IDM).

With the IDM support in the drive, the locks are resident in the drive,
thus, the locking lease is maintained in a central place: the drive
firmware.  We can consider this is a typical client-server model,
every host (or node) in the server cluster launches the request for
leasing mutex to a drive firmware, the drive firmware works as an
arbitrator to grant the mutex to a requester and it can reject other
applicants if the mutex has been acquired.  To satisfy the LVM
activation for different modes, IDM supports two locking modes:
exclusive and shareable.

Every IDM is identified with two IDs, one is the host ID and another is
the resource ID.  The resource ID is a unique identifier for what the
resource it's protected, in the integration with lvmlockd, the resource
ID is combined with VG's UUID and LV's UUID; for the global locking,
the bytes in resource ID are all zeros, and for the VG locking, the
LV's UUID is set as zero.   Every host can generate a random UUID and
use it as the host ID for the SCSI command, this ID is used to clarify
the ownership for mutex.

For easily invoking the IDM commands to drive, like other locking
scheme (e.g. sanlock), a daemon program named IDM lock manager is
created, so the detailed IDM SCSI commands are encapsulated in the
daemon, and lvmlockd uses the wrapper APIs to communicate with the
daemon program.

This patch introduces the IDM locking wrapper layer, it forwards the
locking requests from lvmlockd to the IDM lock manager, and returns the
result from drives' responding.

One thing should be mentioned is the IDM's LVB.  IDM supports LVB to max
7 bytes when stores into the drive, the most significant byte of 8 bytes
is reserved for control bits.  For this reason, the patch maps the
timestamp in macrosecond unit with its cached LVB, essentially, if any
timestamp was updated by other nodes, that means the local LVB is
invalidate.  When the timestamp is stored into drive's LVB, it's
possbile to cause time-going-backwards issue, which is introduced by the
time precision or missing synchronization acrossing over multiple nodes.
So the IDM wrapper fixes up the timestamp by increment 1 to the latest
value and write back into drive.

Currently LVB is used to track VG changes and its purpose is to notify
lvmetad cache invalidation when detects any metadata has been altered;
but lvmetad is not used anymore for caching metadata, LVB doesn't
really work.  It's possible that the LVB functionality could be useful
again in the future, so let's enable it for IDM in the first place.

Signed-off-by: Leo Yan <leo.yan@linaro.org>

1 files changed, 173 insertions, 0 deletions

diff --git a/configure b/configure
index 7c6bd48d2..e2299ee91 100755
--- a/configure
+++ b/configure
@@ -747,6 +747,7 @@ BUILD_DMFILEMAPD
 BUILD_LOCKDDLM_CONTROL
 BUILD_LOCKDDLM
 BUILD_LOCKDSANLOCK
+BUILD_LOCKDIDM
 BUILD_LVMLOCKD
 BUILD_LVMPOLLD
 BUILD_LVMDBUSD
@@ -782,6 +783,8 @@ LOCKD_DLM_LIBS
 LOCKD_DLM_CFLAGS
 LOCKD_SANLOCK_LIBS
 LOCKD_SANLOCK_CFLAGS
+LOCKD_IDM_LIBS
+LOCKD_IDM_CFLAGS
 VALGRIND_LIBS
 VALGRIND_CFLAGS
 GENPNG
@@ -946,6 +949,7 @@ enable_lvmpolld
 enable_lvmlockd_sanlock
 enable_lvmlockd_dlm
 enable_lvmlockd_dlmcontrol
+enable_lvmlockd_idm
 enable_use_lvmlockd
 with_lvmlockd_pidfile
 enable_use_lvmpolld
@@ -1019,6 +1023,8 @@ LOCKD_DLM_CFLAGS
 LOCKD_DLM_LIBS
 LOCKD_DLM_CONTROL_CFLAGS
 LOCKD_DLM_CONTROL_LIBS
+LOCKD_IDM_CFLAGS
+LOCKD_IDM_LIBS
 NOTIFY_DBUS_CFLAGS
 NOTIFY_DBUS_LIBS
 BLKID_CFLAGS
@@ -1678,6 +1684,7 @@ Optional Features:
   --enable-lvmlockd-dlm   enable the LVM lock daemon using dlm
   --enable-lvmlockd-dlmcontrol
                           enable lvmlockd remote refresh using libdlmcontrol
+  --enable-lvmlockd-idm   enable the LVM lock daemon using idm
   --disable-use-lvmlockd  disable usage of LVM lock daemon
   --disable-use-lvmpolld  disable usage of LVM Poll Daemon
   --enable-dmfilemapd     enable the dmstats filemap daemon
@@ -1832,6 +1839,10 @@ Some influential environment variables:
               C compiler flags for LOCKD_DLM_CONTROL, overriding pkg-config
   LOCKD_DLM_CONTROL_LIBS
               linker flags for LOCKD_DLM_CONTROL, overriding pkg-config
+  LOCKD_IDM_CFLAGS
+              C compiler flags for LOCKD_IDM, overriding pkg-config
+  LOCKD_IDM_LIBS
+              linker flags for LOCKD_IDM, overriding pkg-config
   NOTIFY_DBUS_CFLAGS
               C compiler flags for NOTIFY_DBUS, overriding pkg-config
   NOTIFY_DBUS_LIBS
@@ -3124,6 +3135,7 @@ case "$host_os" in
 		LOCKDSANLOCK=no
 		LOCKDDLM=no
 		LOCKDDLM_CONTROL=no
+		LOCKDIDM=no
 		ODIRECT=yes
 		DM_IOCTLS=yes
 		SELINUX=yes
@@ -11192,6 +11204,167 @@ $as_echo "#define LOCKDDLM_CONTROL_SUPPORT 1" >>confdefs.h
 fi
 
 ################################################################################
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to build lvmlockdidm" >&5
+$as_echo_n "checking whether to build lvmlockdidm... " >&6; }
+# Check whether --enable-lvmlockd-idm was given.
+if test "${enable_lvmlockd_idm+set}" = set; then :
+  enableval=$enable_lvmlockd_idm; LOCKDIDM=$enableval
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $LOCKDIDM" >&5
+$as_echo "$LOCKDIDM" >&6; }
+
+BUILD_LOCKDIDM=$LOCKDIDM
+
+if test "$BUILD_LOCKDIDM" = yes; then
+
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for LOCKD_IDM" >&5
+$as_echo_n "checking for LOCKD_IDM... " >&6; }
+
+if test -n "$LOCKD_IDM_CFLAGS"; then
+    pkg_cv_LOCKD_IDM_CFLAGS="$LOCKD_IDM_CFLAGS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libseagate_ilm >= 0.1.0\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libseagate_ilm >= 0.1.0") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_LOCKD_IDM_CFLAGS=`$PKG_CONFIG --cflags "libseagate_ilm >= 0.1.0" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+if test -n "$LOCKD_IDM_LIBS"; then
+    pkg_cv_LOCKD_IDM_LIBS="$LOCKD_IDM_LIBS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"libseagate_ilm >= 0.1.0\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "libseagate_ilm >= 0.1.0") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_LOCKD_IDM_LIBS=`$PKG_CONFIG --libs "libseagate_ilm >= 0.1.0" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+
+
+
+if test $pkg_failed = yes; then
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        LOCKD_IDM_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "libseagate_ilm >= 0.1.0" 2>&1`
+        else
+	        LOCKD_IDM_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "libseagate_ilm >= 0.1.0" 2>&1`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$LOCKD_IDM_PKG_ERRORS" >&5
+
+	$bailout
+elif test $pkg_failed = untried; then
+	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+	$bailout
+else
+	LOCKD_IDM_CFLAGS=$pkg_cv_LOCKD_IDM_CFLAGS
+	LOCKD_IDM_LIBS=$pkg_cv_LOCKD_IDM_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+fi
+
+pkg_failed=no
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for BLKID" >&5
+$as_echo_n "checking for BLKID... " >&6; }
+
+if test -n "$BLKID_CFLAGS"; then
+    pkg_cv_BLKID_CFLAGS="$BLKID_CFLAGS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"blkid >= 2.24\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "blkid >= 2.24") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_BLKID_CFLAGS=`$PKG_CONFIG --cflags "blkid >= 2.24" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+if test -n "$BLKID_LIBS"; then
+    pkg_cv_BLKID_LIBS="$BLKID_LIBS"
+ elif test -n "$PKG_CONFIG"; then
+    if test -n "$PKG_CONFIG" && \
+    { { $as_echo "$as_me:${as_lineno-$LINENO}: \$PKG_CONFIG --exists --print-errors \"blkid >= 2.24\""; } >&5
+  ($PKG_CONFIG --exists --print-errors "blkid >= 2.24") 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; then
+  pkg_cv_BLKID_LIBS=`$PKG_CONFIG --libs "blkid >= 2.24" 2>/dev/null`
+		      test "x$?" != "x0" && pkg_failed=yes
+else
+  pkg_failed=yes
+fi
+ else
+    pkg_failed=untried
+fi
+
+
+
+if test $pkg_failed = yes; then
+   	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+if $PKG_CONFIG --atleast-pkgconfig-version 0.20; then
+        _pkg_short_errors_supported=yes
+else
+        _pkg_short_errors_supported=no
+fi
+        if test $_pkg_short_errors_supported = yes; then
+	        BLKID_PKG_ERRORS=`$PKG_CONFIG --short-errors --print-errors --cflags --libs "blkid >= 2.24" 2>&1`
+        else
+	        BLKID_PKG_ERRORS=`$PKG_CONFIG --print-errors --cflags --libs "blkid >= 2.24" 2>&1`
+        fi
+	# Put the nasty error message in config.log where it belongs
+	echo "$BLKID_PKG_ERRORS" >&5
+
+	$bailout
+elif test $pkg_failed = untried; then
+     	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+	$bailout
+else
+	BLKID_CFLAGS=$pkg_cv_BLKID_CFLAGS
+	BLKID_LIBS=$pkg_cv_BLKID_LIBS
+        { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+	HAVE_LOCKD_IDM=yes
+fi
+
+$as_echo "#define LOCKDIDM_SUPPORT 1" >>confdefs.h
+
+	BUILD_LVMLOCKD=yes
+fi
+
+################################################################################
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether to build lvmlockd" >&5
 $as_echo_n "checking whether to build lvmlockd... " >&6; }
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $BUILD_LVMLOCKD" >&5