GFS2: Merge lock_dlm module into GFS2

This is the big patch that I've been working on for some time
now. There are many reasons for wanting to make this change
such as:
 o Reducing overhead by eliminating duplicated fields between structures
 o Simplifcation of the code (reduces the code size by a fair bit)
 o The locking interface is now the DLM interface itself as proposed
   some time ago.
 o Fewer lookups of glocks when processing replies from the DLM
 o Fewer memory allocations/deallocations for each glock
 o Scope to do further optimisations in the future (but this patch is
   more than big enough for now!)

Please note that (a) this patch relates to the lock_dlm module and
not the DLM itself, that is still a separate module; and (b) that
we retain the ability to build GFS2 as a standalone single node
filesystem with out requiring the DLM.

This patch needs a lot of testing, hence my keeping it I restarted
my -git tree after the last merge window. That way, this has the maximum
exposure before its merged. This is (modulo a few minor bug fixes) the
same patch that I've been posting on and off the the last three months
and its passed a number of different tests so far.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 54 insertions, 5 deletions

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index a0117d6eb145..0af7c24de6a1 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -12,6 +12,8 @@
 
 #include <linux/fs.h>
 #include <linux/workqueue.h>
+#include <linux/dlm.h>
+#include <linux/buffer_head.h>
 
 #define DIO_WAIT        0x00000010
 #define DIO_METADATA    0x00000020
@@ -26,6 +28,7 @@ struct gfs2_trans;
 struct gfs2_ail;
 struct gfs2_jdesc;
 struct gfs2_sbd;
+struct lm_lockops;
 
 typedef void (*gfs2_glop_bh_t) (struct gfs2_glock *gl, unsigned int ret);
 
@@ -121,6 +124,28 @@ struct gfs2_bufdata {
         struct list_head bd_ail_gl_list;
 };
 
+/*
+ * Internally, we prefix things with gdlm_ and GDLM_ (for gfs-dlm) since a
+ * prefix of lock_dlm_ gets awkward.
+ */
+
+#define GDLM_STRNAME_BYTES      25
+#define GDLM_LVB_SIZE           32
+
+enum {
+        DFL_BLOCK_LOCKS         = 0,
+};
+
+struct lm_lockname {
+        u64 ln_number;
+        unsigned int ln_type;
+};
+
+#define lm_name_equal(name1, name2) \
+        (((name1)->ln_number == (name2)->ln_number) && \
+         ((name1)->ln_type == (name2)->ln_type))
+
+
 struct gfs2_glock_operations {
         void (*go_xmote_th) (struct gfs2_glock *gl);
         int (*go_xmote_bh) (struct gfs2_glock *gl, struct gfs2_holder *gh);
@@ -162,6 +187,8 @@ enum {
         GLF_LFLUSH                      = 7,
         GLF_INVALIDATE_IN_PROGRESS      = 8,
         GLF_REPLY_PENDING               = 9,
+        GLF_INITIAL                     = 10,
+        GLF_FROZEN                      = 11,
 };
 
 struct gfs2_glock {
@@ -181,10 +208,9 @@ struct gfs2_glock {
         struct list_head gl_holders;
 
         const struct gfs2_glock_operations *gl_ops;
-        void *gl_lock;
-        char *gl_lvb;
-        atomic_t gl_lvb_count;
-
+        char gl_strname[GDLM_STRNAME_BYTES];
+        struct dlm_lksb gl_lksb;
+        char gl_lvb[32];
         unsigned long gl_stamp;
         unsigned long gl_tchange;
         void *gl_object;
@@ -447,6 +473,30 @@ struct gfs2_sb_host {
         char sb_locktable[GFS2_LOCKNAME_LEN];
 };
 
+/*
+ * lm_mount() return values
+ *
+ * ls_jid - the journal ID this node should use
+ * ls_first - this node is the first to mount the file system
+ * ls_lockspace - lock module's context for this file system
+ * ls_ops - lock module's functions
+ */
+
+struct lm_lockstruct {
+        u32 ls_id;
+        unsigned int ls_jid;
+        unsigned int ls_first;
+        unsigned int ls_first_done;
+        unsigned int ls_nodir;
+        const struct lm_lockops *ls_ops;
+        unsigned long ls_flags;
+        dlm_lockspace_t *ls_dlm;
+
+        int ls_recover_jid;
+        int ls_recover_jid_done;
+        int ls_recover_jid_status;
+};
+
 struct gfs2_sbd {
         struct super_block *sd_vfs;
         struct kobject sd_kobj;
@@ -520,7 +570,6 @@ struct gfs2_sbd {
         spinlock_t sd_jindex_spin;
         struct mutex sd_jindex_mutex;
         unsigned int sd_journals;
-        unsigned long sd_jindex_refresh_time;
 
         struct gfs2_jdesc *sd_jdesc;
         struct gfs2_holder sd_journal_gh;