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, 94 insertions, 40 deletions

diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 402b6a2cd2c9..95bb33e41a76 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -17,7 +17,6 @@
 #include <linux/namei.h>
 #include <linux/mount.h>
 #include <linux/gfs2_ondisk.h>
-#include <linux/lm_interface.h>
 
 #include "gfs2.h"
 #include "incore.h"
@@ -627,13 +626,13 @@ static int map_journal_extents(struct gfs2_sbd *sdp)
 	return rc;
 }
 
-static void gfs2_lm_others_may_mount(struct gfs2_sbd *sdp)
+static void gfs2_others_may_mount(struct gfs2_sbd *sdp)
 {
-	if (!sdp->sd_lockstruct.ls_ops->lm_others_may_mount)
-		return;
-	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		sdp->sd_lockstruct.ls_ops->lm_others_may_mount(
-					sdp->sd_lockstruct.ls_lockspace);
+	char *message = "FIRSTMOUNT=Done";
+	char *envp[] = { message, NULL };
+	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
+	ls->ls_first_done = 1;
+	kobject_uevent_env(&sdp->sd_kobj, KOBJ_CHANGE, envp);
 }
 
 /**
@@ -793,7 +792,7 @@ static int init_journal(struct gfs2_sbd *sdp, int undo)
 			}
 		}
 
-		gfs2_lm_others_may_mount(sdp);
+		gfs2_others_may_mount(sdp);
 	} else if (!sdp->sd_args.ar_spectator) {
 		error = gfs2_recover_journal(sdp->sd_jdesc);
 		if (error) {
@@ -1002,7 +1001,6 @@ static int init_threads(struct gfs2_sbd *sdp, int undo)
 		goto fail_quotad;
 
 	sdp->sd_log_flush_time = jiffies;
-	sdp->sd_jindex_refresh_time = jiffies;
 
 	p = kthread_run(gfs2_logd, sdp, "gfs2_logd");
 	error = IS_ERR(p);
@@ -1030,6 +1028,17 @@ fail:
 	return error;
 }
 
+static const match_table_t nolock_tokens = {
+	{ Opt_jid, "jid=%d\n", },
+	{ Opt_err, NULL },
+};
+
+static const struct lm_lockops nolock_ops = {
+	.lm_proto_name = "lock_nolock",
+	.lm_put_lock = kmem_cache_free,
+	.lm_tokens = &nolock_tokens,
+};
+
 /**
  * gfs2_lm_mount - mount a locking protocol
  * @sdp: the filesystem
@@ -1041,31 +1050,73 @@ fail:
 
 static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
 {
-	char *proto = sdp->sd_proto_name;
-	char *table = sdp->sd_table_name;
-	int flags = LM_MFLAG_CONV_NODROP;
-	int error;
+	const struct lm_lockops *lm;
+	struct lm_lockstruct *ls = &sdp->sd_lockstruct;
+	struct gfs2_args *args = &sdp->sd_args;
+	const char *proto = sdp->sd_proto_name;
+	const char *table = sdp->sd_table_name;
+	const char *fsname;
+	char *o, *options;
+	int ret;
 
-	if (sdp->sd_args.ar_spectator)
-		flags |= LM_MFLAG_SPECTATOR;
+	if (!strcmp("lock_nolock", proto)) {
+		lm = &nolock_ops;
+		sdp->sd_args.ar_localflocks = 1;
+		sdp->sd_args.ar_localcaching = 1;
+#ifdef CONFIG_GFS2_FS_LOCKING_DLM
+	} else if (!strcmp("lock_dlm", proto)) {
+		lm = &gfs2_dlm_ops;
+#endif
+	} else {
+		printk(KERN_INFO "GFS2: can't find protocol %s\n", proto);
+		return -ENOENT;
+	}
 
 	fs_info(sdp, "Trying to join cluster \"%s\", \"%s\"\n", proto, table);
 
-	error = gfs2_mount_lockproto(proto, table, sdp->sd_args.ar_hostdata,
-				     gfs2_glock_cb, sdp,
-				     GFS2_MIN_LVB_SIZE, flags,
-				     &sdp->sd_lockstruct, &sdp->sd_kobj);
-	if (error) {
-		fs_info(sdp, "can't mount proto=%s, table=%s, hostdata=%s\n",
-			proto, table, sdp->sd_args.ar_hostdata);
-		goto out;
-	}
+	ls->ls_ops = lm;
+	ls->ls_first = 1;
+	ls->ls_id = 0;
 
-	if (gfs2_assert_warn(sdp, sdp->sd_lockstruct.ls_ops) ||
-	    gfs2_assert_warn(sdp, sdp->sd_lockstruct.ls_lvb_size >=
-				  GFS2_MIN_LVB_SIZE)) {
-		gfs2_unmount_lockproto(&sdp->sd_lockstruct);
-		goto out;
+	for (options = args->ar_hostdata; (o = strsep(&options, ":")); ) {
+		substring_t tmp[MAX_OPT_ARGS];
+		int token, option;
+
+		if (!o || !*o)
+			continue;
+
+		token = match_token(o, *lm->lm_tokens, tmp);
+		switch (token) {
+		case Opt_jid:
+			ret = match_int(&tmp[0], &option);
+			if (ret || option < 0) 
+				goto hostdata_error;
+			ls->ls_jid = option;
+			break;
+		case Opt_id:
+			ret = match_int(&tmp[0], &option);
+			if (ret)
+				goto hostdata_error;
+			ls->ls_id = option;
+			break;
+		case Opt_first:
+			ret = match_int(&tmp[0], &option);
+			if (ret || (option != 0 && option != 1))
+				goto hostdata_error;
+			ls->ls_first = option;
+			break;
+		case Opt_nodir:
+			ret = match_int(&tmp[0], &option);
+			if (ret || (option != 0 && option != 1))
+				goto hostdata_error;
+			ls->ls_nodir = option;
+			break;
+		case Opt_err:
+		default:
+hostdata_error:
+			fs_info(sdp, "unknown hostdata (%s)\n", o);
+			return -EINVAL;
+		}
 	}
 
 	if (sdp->sd_args.ar_spectator)
@@ -1074,22 +1125,25 @@ static int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent)
 		snprintf(sdp->sd_fsname, GFS2_FSNAME_LEN, "%s.%u", table,
 			 sdp->sd_lockstruct.ls_jid);
 
-	fs_info(sdp, "Joined cluster. Now mounting FS...\n");
-
-	if ((sdp->sd_lockstruct.ls_flags & LM_LSFLAG_LOCAL) &&
-	    !sdp->sd_args.ar_ignore_local_fs) {
-		sdp->sd_args.ar_localflocks = 1;
-		sdp->sd_args.ar_localcaching = 1;
+	fsname = strchr(table, ':');
+	if (fsname)
+		fsname++;
+	if (lm->lm_mount == NULL) {
+		fs_info(sdp, "Now mounting FS...\n");
+		return 0;
 	}
-
-out:
-	return error;
+	ret = lm->lm_mount(sdp, fsname);
+	if (ret == 0)
+		fs_info(sdp, "Joined cluster. Now mounting FS...\n");
+	return ret;
 }
 
 void gfs2_lm_unmount(struct gfs2_sbd *sdp)
 {
-	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		gfs2_unmount_lockproto(&sdp->sd_lockstruct);
+	const struct lm_lockops *lm = sdp->sd_lockstruct.ls_ops;
+	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)) &&
+	    lm->lm_unmount)
+		lm->lm_unmount(sdp);
 }
 
 /**