Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/dlm:
  dlm: change rsbtbl rwlock to spinlock
  dlm: fix seq_file usage in debugfs lock dump

fs/dlm/debug_fs.c

@@ -1,7 +1,7 @@
 /******************************************************************************
 *******************************************************************************
 **
-**  Copyright (C) 2005-2008 Red Hat, Inc.  All rights reserved.
+**  Copyright (C) 2005-2009 Red Hat, Inc.  All rights reserved.
 **
 **  This copyrighted material is made available to anyone wishing to use,
 **  modify, copy, or redistribute it subject to the terms and conditions
@@ -25,19 +25,6 @@ static struct mutex debug_buf_lock;
 
 static struct dentry *dlm_root;
 
-struct rsb_iter {
-	int entry;
-	int format;
-	int header;
-	struct dlm_ls *ls;
-	struct list_head *next;
-	struct dlm_rsb *rsb;
-};
-
-/*
- * dump all rsb's in the lockspace hash table
- */
-
 static char *print_lockmode(int mode)
 {
 	switch (mode) {
@@ -60,13 +47,13 @@ static char *print_lockmode(int mode)
 	}
 }
 
-static void print_format1_lock(struct seq_file *s, struct dlm_lkb *lkb,
-			       struct dlm_rsb *res)
+static int print_format1_lock(struct seq_file *s, struct dlm_lkb *lkb,
+			      struct dlm_rsb *res)
 {
 	seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
 
-	if (lkb->lkb_status == DLM_LKSTS_CONVERT
-	    || lkb->lkb_status == DLM_LKSTS_WAITING)
+	if (lkb->lkb_status == DLM_LKSTS_CONVERT ||
+	    lkb->lkb_status == DLM_LKSTS_WAITING)
 		seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
 
 	if (lkb->lkb_nodeid) {
@@ -80,33 +67,42 @@ static void print_format1_lock(struct seq_file *s, struct dlm_lkb *lkb,
 	if (lkb->lkb_wait_type)
 		seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
 
-	seq_printf(s, "\n");
+	return seq_printf(s, "\n");
 }
 
 static int print_format1(struct dlm_rsb *res, struct seq_file *s)
 {
 	struct dlm_lkb *lkb;
 	int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
+	int rv;
 
 	lock_rsb(res);
 
-	seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
+	rv = seq_printf(s, "\nResource %p Name (len=%d) \"",
+			res, res->res_length);
+	if (rv)
+		goto out;
+
 	for (i = 0; i < res->res_length; i++) {
 		if (isprint(res->res_name[i]))
 			seq_printf(s, "%c", res->res_name[i]);
 		else
 			seq_printf(s, "%c", '.');
 	}
+
 	if (res->res_nodeid > 0)
-		seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
-			   res->res_nodeid);
+		rv = seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
+				res->res_nodeid);
 	else if (res->res_nodeid == 0)
-		seq_printf(s, "\"  \nMaster Copy\n");
+		rv = seq_printf(s, "\"  \nMaster Copy\n");
 	else if (res->res_nodeid == -1)
-		seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
-			   res->res_first_lkid);
+		rv = seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
+			   	res->res_first_lkid);
 	else
-		seq_printf(s, "\"  \nInvalid master %d\n", res->res_nodeid);
+		rv = seq_printf(s, "\"  \nInvalid master %d\n",
+				res->res_nodeid);
+	if (rv)
+		goto out;
 
 	/* Print the LVB: */
 	if (res->res_lvbptr) {
@@ -119,52 +115,66 @@ static int print_format1(struct dlm_rsb *res, struct seq_file *s)
 		}
 		if (rsb_flag(res, RSB_VALNOTVALID))
 			seq_printf(s, " (INVALID)");
-		seq_printf(s, "\n");
+		rv = seq_printf(s, "\n");
+		if (rv)
+			goto out;
 	}
 
 	root_list = !list_empty(&res->res_root_list);
 	recover_list = !list_empty(&res->res_recover_list);
 
 	if (root_list || recover_list) {
-		seq_printf(s, "Recovery: root %d recover %d flags %lx "
-			   "count %d\n", root_list, recover_list,
-			   res->res_flags, res->res_recover_locks_count);
+		rv = seq_printf(s, "Recovery: root %d recover %d flags %lx "
+				"count %d\n", root_list, recover_list,
+			   	res->res_flags, res->res_recover_locks_count);
+		if (rv)
+			goto out;
 	}
 
 	/* Print the locks attached to this resource */
 	seq_printf(s, "Granted Queue\n");
-	list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
-		print_format1_lock(s, lkb, res);
+	list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue) {
+		rv = print_format1_lock(s, lkb, res);
+		if (rv)
+			goto out;
+	}
 
 	seq_printf(s, "Conversion Queue\n");
-	list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
-		print_format1_lock(s, lkb, res);
+	list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue) {
+		rv = print_format1_lock(s, lkb, res);
+		if (rv)
+			goto out;
+	}
 
 	seq_printf(s, "Waiting Queue\n");
-	list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
-		print_format1_lock(s, lkb, res);
+	list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue) {
+		rv = print_format1_lock(s, lkb, res);
+		if (rv)
+			goto out;
+	}
 
 	if (list_empty(&res->res_lookup))
 		goto out;
 
 	seq_printf(s, "Lookup Queue\n");
 	list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
-		seq_printf(s, "%08x %s", lkb->lkb_id,
-			   print_lockmode(lkb->lkb_rqmode));
+		rv = seq_printf(s, "%08x %s", lkb->lkb_id,
+				print_lockmode(lkb->lkb_rqmode));
 		if (lkb->lkb_wait_type)
 			seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
-		seq_printf(s, "\n");
+		rv = seq_printf(s, "\n");
 	}
  out:
 	unlock_rsb(res);
-	return 0;
+	return rv;
 }
 
-static void print_format2_lock(struct seq_file *s, struct dlm_lkb *lkb,
-			       struct dlm_rsb *r)
+static int print_format2_lock(struct seq_file *s, struct dlm_lkb *lkb,
+			      struct dlm_rsb *r)
 {
 	u64 xid = 0;
 	u64 us;
+	int rv;
 
 	if (lkb->lkb_flags & DLM_IFL_USER) {
 		if (lkb->lkb_ua)
@@ -177,69 +187,82 @@ static void print_format2_lock(struct seq_file *s, struct dlm_lkb *lkb,
 	/* id nodeid remid pid xid exflags flags sts grmode rqmode time_us
 	   r_nodeid r_len r_name */
 
-	seq_printf(s, "%x %d %x %u %llu %x %x %d %d %d %llu %u %d \"%s\"\n",
-		   lkb->lkb_id,
-		   lkb->lkb_nodeid,
-		   lkb->lkb_remid,
-		   lkb->lkb_ownpid,
-		   (unsigned long long)xid,
-		   lkb->lkb_exflags,
-		   lkb->lkb_flags,
-		   lkb->lkb_status,
-		   lkb->lkb_grmode,
-		   lkb->lkb_rqmode,
-		   (unsigned long long)us,
-		   r->res_nodeid,
-		   r->res_length,
-		   r->res_name);
+	rv = seq_printf(s, "%x %d %x %u %llu %x %x %d %d %d %llu %u %d \"%s\"\n",
+			lkb->lkb_id,
+			lkb->lkb_nodeid,
+			lkb->lkb_remid,
+			lkb->lkb_ownpid,
+			(unsigned long long)xid,
+			lkb->lkb_exflags,
+			lkb->lkb_flags,
+			lkb->lkb_status,
+			lkb->lkb_grmode,
+			lkb->lkb_rqmode,
+			(unsigned long long)us,
+			r->res_nodeid,
+			r->res_length,
+			r->res_name);
+	return rv;
 }
 
 static int print_format2(struct dlm_rsb *r, struct seq_file *s)
 {
 	struct dlm_lkb *lkb;
+	int rv = 0;
 
 	lock_rsb(r);
 
-	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
-		print_format2_lock(s, lkb, r);
-
-	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
-		print_format2_lock(s, lkb, r);
+	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
+		rv = print_format2_lock(s, lkb, r);
+		if (rv)
+			goto out;
+	}
 
-	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
-		print_format2_lock(s, lkb, r);
+	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
+		rv = print_format2_lock(s, lkb, r);
+		if (rv)
+			goto out;
+	}
 
+	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) {
+		rv = print_format2_lock(s, lkb, r);
+		if (rv)
+			goto out;
+	}
+ out:
 	unlock_rsb(r);
-	return 0;
+	return rv;
 }
 
-static void print_format3_lock(struct seq_file *s, struct dlm_lkb *lkb,
-			       int rsb_lookup)
+static int print_format3_lock(struct seq_file *s, struct dlm_lkb *lkb,
+			      int rsb_lookup)
 {
 	u64 xid = 0;
+	int rv;
 
 	if (lkb->lkb_flags & DLM_IFL_USER) {
 		if (lkb->lkb_ua)
 			xid = lkb->lkb_ua->xid;
 	}
 
-	seq_printf(s, "lkb %x %d %x %u %llu %x %x %d %d %d %d %d %d %u %llu %llu\n",
-		   lkb->lkb_id,
-		   lkb->lkb_nodeid,
-		   lkb->lkb_remid,
-		   lkb->lkb_ownpid,
-		   (unsigned long long)xid,
-		   lkb->lkb_exflags,
-		   lkb->lkb_flags,
-		   lkb->lkb_status,
-		   lkb->lkb_grmode,
-		   lkb->lkb_rqmode,
-		   lkb->lkb_highbast,
-		   rsb_lookup,
-		   lkb->lkb_wait_type,
-		   lkb->lkb_lvbseq,
-		   (unsigned long long)ktime_to_ns(lkb->lkb_timestamp),
-		   (unsigned long long)ktime_to_ns(lkb->lkb_time_bast));
+	rv = seq_printf(s, "lkb %x %d %x %u %llu %x %x %d %d %d %d %d %d %u %llu %llu\n",
+			lkb->lkb_id,
+			lkb->lkb_nodeid,
+			lkb->lkb_remid,
+			lkb->lkb_ownpid,
+			(unsigned long long)xid,
+			lkb->lkb_exflags,
+			lkb->lkb_flags,
+			lkb->lkb_status,
+			lkb->lkb_grmode,
+			lkb->lkb_rqmode,
+			lkb->lkb_highbast,
+			rsb_lookup,
+			lkb->lkb_wait_type,
+			lkb->lkb_lvbseq,
+			(unsigned long long)ktime_to_ns(lkb->lkb_timestamp),
+			(unsigned long long)ktime_to_ns(lkb->lkb_time_bast));
+	return rv;
 }
 
 static int print_format3(struct dlm_rsb *r, struct seq_file *s)
@@ -247,18 +270,21 @@ static int print_format3(struct dlm_rsb *r, struct seq_file *s)
 	struct dlm_lkb *lkb;
 	int i, lvblen = r->res_ls->ls_lvblen;
 	int print_name = 1;
+	int rv;
 
 	lock_rsb(r);
 
-	seq_printf(s, "rsb %p %d %x %lx %d %d %u %d ",
-		   r,
-		   r->res_nodeid,
-		   r->res_first_lkid,
-		   r->res_flags,
-		   !list_empty(&r->res_root_list),
-		   !list_empty(&r->res_recover_list),
-		   r->res_recover_locks_count,
-		   r->res_length);
+	rv = seq_printf(s, "rsb %p %d %x %lx %d %d %u %d ",
+			r,
+			r->res_nodeid,
+			r->res_first_lkid,
+			r->res_flags,
+			!list_empty(&r->res_root_list),
+			!list_empty(&r->res_recover_list),
+			r->res_recover_locks_count,
+			r->res_length);
+	if (rv)
+		goto out;
 
 	for (i = 0; i < r->res_length; i++) {
 		if (!isascii(r->res_name[i]) || !isprint(r->res_name[i]))
@@ -273,7 +299,9 @@ static int print_format3(struct dlm_rsb *r, struct seq_file *s)
 		else
 			seq_printf(s, " %02x", (unsigned char)r->res_name[i]);
 	}
-	seq_printf(s, "\n");
+	rv = seq_printf(s, "\n");
+	if (rv)
+		goto out;
 
 	if (!r->res_lvbptr)
 		goto do_locks;
@@ -282,344 +310,294 @@ static int print_format3(struct dlm_rsb *r, struct seq_file *s)
 
 	for (i = 0; i < lvblen; i++)
 		seq_printf(s, " %02x", (unsigned char)r->res_lvbptr[i]);
-	seq_printf(s, "\n");
+	rv = seq_printf(s, "\n");
+	if (rv)
+		goto out;
 
  do_locks:
-	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
-		print_format3_lock(s, lkb, 0);
-
-	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
-		print_format3_lock(s, lkb, 0);
-
-	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
-		print_format3_lock(s, lkb, 0);
-
-	list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup)
-		print_format3_lock(s, lkb, 1);
-
-	unlock_rsb(r);
-	return 0;
-}
-
-static int rsb_iter_next(struct rsb_iter *ri)
-{
-	struct dlm_ls *ls = ri->ls;
-	int i;
-
-	if (!ri->next) {
- top:
-		/* Find the next non-empty hash bucket */
-		for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
-			read_lock(&ls->ls_rsbtbl[i].lock);
-			if (!list_empty(&ls->ls_rsbtbl[i].list)) {
-				ri->next = ls->ls_rsbtbl[i].list.next;
-				ri->rsb = list_entry(ri->next, struct dlm_rsb,
-							res_hashchain);
-				dlm_hold_rsb(ri->rsb);
-				read_unlock(&ls->ls_rsbtbl[i].lock);
-				break;
-			}
-			read_unlock(&ls->ls_rsbtbl[i].lock);
-		}
-		ri->entry = i;
-
-		if (ri->entry >= ls->ls_rsbtbl_size)
-			return 1;
-	} else {
-		struct dlm_rsb *old = ri->rsb;
-		i = ri->entry;
-		read_lock(&ls->ls_rsbtbl[i].lock);
-		ri->next = ri->next->next;
-		if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
-			/* End of list - move to next bucket */
-			ri->next = NULL;
-			ri->entry++;
-			read_unlock(&ls->ls_rsbtbl[i].lock);
-			dlm_put_rsb(old);
-			goto top;
-		}
-		ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
-		dlm_hold_rsb(ri->rsb);
-		read_unlock(&ls->ls_rsbtbl[i].lock);
-		dlm_put_rsb(old);
+	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue) {
+		rv = print_format3_lock(s, lkb, 0);
+		if (rv)
+			goto out;
 	}
 
-	return 0;
-}
-
-static void rsb_iter_free(struct rsb_iter *ri)
-{
-	kfree(ri);
-}
-
-static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
-{
-	struct rsb_iter *ri;
-
-	ri = kzalloc(sizeof *ri, GFP_KERNEL);
-	if (!ri)
-		return NULL;
-
-	ri->ls = ls;
-	ri->entry = 0;
-	ri->next = NULL;
-	ri->format = 1;
-
-	if (rsb_iter_next(ri)) {
-		rsb_iter_free(ri);
-		return NULL;
+	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue) {
+		rv = print_format3_lock(s, lkb, 0);
+		if (rv)
+			goto out;
 	}
 
-	return ri;
-}
-
-static void *rsb_seq_start(struct seq_file *file, loff_t *pos)
-{
-	struct rsb_iter *ri;
-	loff_t n = *pos;
-
-	ri = rsb_iter_init(file->private);
-	if (!ri)
-		return NULL;
-
-	while (n--) {
-		if (rsb_iter_next(ri)) {
-			rsb_iter_free(ri);
-			return NULL;
-		}
+	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue) {
+		rv = print_format3_lock(s, lkb, 0);
+		if (rv)
+			goto out;
 	}
 
-	return ri;
-}
-
-static void *rsb_seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
-{
-	struct rsb_iter *ri = iter_ptr;
-
-	(*pos)++;
-
-	if (rsb_iter_next(ri)) {
-		rsb_iter_free(ri);
-		return NULL;
+	list_for_each_entry(lkb, &r->res_lookup, lkb_rsb_lookup) {
+		rv = print_format3_lock(s, lkb, 1);
+		if (rv)
+			goto out;
 	}
-
-	return ri;
+ out:
+	unlock_rsb(r);
+	return rv;
 }
 
-static void rsb_seq_stop(struct seq_file *file, void *iter_ptr)
-{
-	/* nothing for now */
-}
+struct rsbtbl_iter {
+	struct dlm_rsb *rsb;
+	unsigned bucket;
+	int format;
+	int header;
+};
 
-static int rsb_seq_show(struct seq_file *file, void *iter_ptr)
+/* seq_printf returns -1 if the buffer is full, and 0 otherwise.
+   If the buffer is full, seq_printf can be called again, but it
+   does nothing and just returns -1.  So, the these printing routines
+   periodically check the return value to avoid wasting too much time
+   trying to print to a full buffer. */
+
+static int table_seq_show(struct seq_file *seq, void *iter_ptr)
 {
-	struct rsb_iter *ri = iter_ptr;
+	struct rsbtbl_iter *ri = iter_ptr;
+	int rv = 0;
 
 	switch (ri->format) {
 	case 1:
-		print_format1(ri->rsb, file);
+		rv = print_format1(ri->rsb, seq);
 		break;
 	case 2:
 		if (ri->header) {
-			seq_printf(file, "id nodeid remid pid xid exflags "
-					 "flags sts grmode rqmode time_ms "
-					 "r_nodeid r_len r_name\n");
+			seq_printf(seq, "id nodeid remid pid xid exflags "
+					"flags sts grmode rqmode time_ms "
+					"r_nodeid r_len r_name\n");
 			ri->header = 0;
 		}
-		print_format2(ri->rsb, file);
+		rv = print_format2(ri->rsb, seq);
 		break;
 	case 3:
 		if (ri->header) {
-			seq_printf(file, "version rsb 1.1 lvb 1.1 lkb 1.1\n");
+			seq_printf(seq, "version rsb 1.1 lvb 1.1 lkb 1.1\n");
 			ri->header = 0;
 		}
-		print_format3(ri->rsb, file);
+		rv = print_format3(ri->rsb, seq);
 		break;
 	}
 
-	return 0;
+	return rv;
 }
 
-static struct seq_operations rsb_seq_ops = {
-	.start = rsb_seq_start,
-	.next  = rsb_seq_next,
-	.stop  = rsb_seq_stop,
-	.show  = rsb_seq_show,
-};
+static struct seq_operations format1_seq_ops;
+static struct seq_operations format2_seq_ops;
+static struct seq_operations format3_seq_ops;
 
-static int rsb_open(struct inode *inode, struct file *file)
+static void *table_seq_start(struct seq_file *seq, loff_t *pos)
 {
-	struct seq_file *seq;
-	int ret;
-
-	ret = seq_open(file, &rsb_seq_ops);
-	if (ret)
-		return ret;
-
-	seq = file->private_data;
-	seq->private = inode->i_private;
-
-	return 0;
-}
-
-static const struct file_operations rsb_fops = {
-	.owner   = THIS_MODULE,
-	.open    = rsb_open,
-	.read    = seq_read,
-	.llseek  = seq_lseek,
-	.release = seq_release
-};
+	struct dlm_ls *ls = seq->private;
+	struct rsbtbl_iter *ri;
+	struct dlm_rsb *r;
+	loff_t n = *pos;
+	unsigned bucket, entry;
 
-/*
- * Dump state in compact per-lock listing
- */
+	bucket = n >> 32;
+	entry = n & ((1LL << 32) - 1);
 
-static struct rsb_iter *locks_iter_init(struct dlm_ls *ls, loff_t *pos)
-{
-	struct rsb_iter *ri;
+	if (bucket >= ls->ls_rsbtbl_size)
+		return NULL;
 
-	ri = kzalloc(sizeof *ri, GFP_KERNEL);
+	ri = kzalloc(sizeof(struct rsbtbl_iter), GFP_KERNEL);
 	if (!ri)
 		return NULL;
-
-	ri->ls = ls;
-	ri->entry = 0;
-	ri->next = NULL;
-	ri->format = 2;
-
-	if (*pos == 0)
+	if (n == 0)
 		ri->header = 1;
-
-	if (rsb_iter_next(ri)) {
-		rsb_iter_free(ri);
-		return NULL;
+	if (seq->op == &format1_seq_ops)
+		ri->format = 1;
+	if (seq->op == &format2_seq_ops)
+		ri->format = 2;
+	if (seq->op == &format3_seq_ops)
+		ri->format = 3;
+
+	spin_lock(&ls->ls_rsbtbl[bucket].lock);
+	if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
+		list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list,
+				    res_hashchain) {
+			if (!entry--) {
+				dlm_hold_rsb(r);
+				ri->rsb = r;
+				ri->bucket = bucket;
+				spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+				return ri;
+			}
+		}
 	}
+	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 
-	return ri;
-}
+	/*
+	 * move to the first rsb in the next non-empty bucket
+	 */
 
-static void *locks_seq_start(struct seq_file *file, loff_t *pos)
-{
-	struct rsb_iter *ri;
-	loff_t n = *pos;
+	/* zero the entry */
+	n &= ~((1LL << 32) - 1);
 
-	ri = locks_iter_init(file->private, pos);
-	if (!ri)
-		return NULL;
+	while (1) {
+		bucket++;
+		n += 1LL << 32;
 
-	while (n--) {
-		if (rsb_iter_next(ri)) {
-			rsb_iter_free(ri);
+		if (bucket >= ls->ls_rsbtbl_size) {
+			kfree(ri);
 			return NULL;
 		}
-	}
 
-	return ri;
+		spin_lock(&ls->ls_rsbtbl[bucket].lock);
+		if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
+			r = list_first_entry(&ls->ls_rsbtbl[bucket].list,
+					     struct dlm_rsb, res_hashchain);
+			dlm_hold_rsb(r);
+			ri->rsb = r;
+			ri->bucket = bucket;
+			spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+			*pos = n;
+			return ri;
+		}
+		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+	}
 }
 
-static struct seq_operations locks_seq_ops = {
-	.start = locks_seq_start,
-	.next  = rsb_seq_next,
-	.stop  = rsb_seq_stop,
-	.show  = rsb_seq_show,
-};
-
-static int locks_open(struct inode *inode, struct file *file)
+static void *table_seq_next(struct seq_file *seq, void *iter_ptr, loff_t *pos)
 {
-	struct seq_file *seq;
-	int ret;
-
-	ret = seq_open(file, &locks_seq_ops);
-	if (ret)
-		return ret;
-
-	seq = file->private_data;
-	seq->private = inode->i_private;
-
-	return 0;
-}
-
-static const struct file_operations locks_fops = {
-	.owner   = THIS_MODULE,
-	.open    = locks_open,
-	.read    = seq_read,
-	.llseek  = seq_lseek,
-	.release = seq_release
-};
-
-/*
- * Dump all rsb/lvb/lkb state in compact listing, more complete than _locks
- * This can replace both formats 1 and 2 eventually.
- */
+	struct dlm_ls *ls = seq->private;
+	struct rsbtbl_iter *ri = iter_ptr;
+	struct list_head *next;
+	struct dlm_rsb *r, *rp;
+	loff_t n = *pos;
+	unsigned bucket;
+
+	bucket = n >> 32;
+
+	/*
+	 * move to the next rsb in the same bucket
+	 */
+
+	spin_lock(&ls->ls_rsbtbl[bucket].lock);
+	rp = ri->rsb;
+	next = rp->res_hashchain.next;
+
+	if (next != &ls->ls_rsbtbl[bucket].list) {
+		r = list_entry(next, struct dlm_rsb, res_hashchain);
+		dlm_hold_rsb(r);
+		ri->rsb = r;
+		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+		dlm_put_rsb(rp);
+		++*pos;
+		return ri;
+	}
+	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+	dlm_put_rsb(rp);
 
-static struct rsb_iter *all_iter_init(struct dlm_ls *ls, loff_t *pos)
-{
-	struct rsb_iter *ri;
+	/*
+	 * move to the first rsb in the next non-empty bucket
+	 */
 
-	ri = kzalloc(sizeof *ri, GFP_KERNEL);
-	if (!ri)
-		return NULL;
+	/* zero the entry */
+	n &= ~((1LL << 32) - 1);
 
-	ri->ls = ls;
-	ri->entry = 0;
-	ri->next = NULL;
-	ri->format = 3;
+	while (1) {
+		bucket++;
+		n += 1LL << 32;
 
-	if (*pos == 0)
-		ri->header = 1;
+		if (bucket >= ls->ls_rsbtbl_size) {
+			kfree(ri);
+			return NULL;
+		}
 
-	if (rsb_iter_next(ri)) {
-		rsb_iter_free(ri);
-		return NULL;
+		spin_lock(&ls->ls_rsbtbl[bucket].lock);
+		if (!list_empty(&ls->ls_rsbtbl[bucket].list)) {
+			r = list_first_entry(&ls->ls_rsbtbl[bucket].list,
+					     struct dlm_rsb, res_hashchain);
+			dlm_hold_rsb(r);
+			ri->rsb = r;
+			ri->bucket = bucket;
+			spin_unlock(&ls->ls_rsbtbl[bucket].lock);
+			*pos = n;
+			return ri;
+		}
+		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 	}
-
-	return ri;
 }
 
-static void *all_seq_start(struct seq_file *file, loff_t *pos)
+static void table_seq_stop(struct seq_file *seq, void *iter_ptr)
 {
-	struct rsb_iter *ri;
-	loff_t n = *pos;
-
-	ri = all_iter_init(file->private, pos);
-	if (!ri)
-		return NULL;
+	struct rsbtbl_iter *ri = iter_ptr;
 
-	while (n--) {
-		if (rsb_iter_next(ri)) {
-			rsb_iter_free(ri);
-			return NULL;
-		}
+	if (ri) {
+		dlm_put_rsb(ri->rsb);
+		kfree(ri);
 	}
-
-	return ri;
 }
 
-static struct seq_operations all_seq_ops = {
-	.start = all_seq_start,
-	.next  = rsb_seq_next,
-	.stop  = rsb_seq_stop,
-	.show  = rsb_seq_show,
+static struct seq_operations format1_seq_ops = {
+	.start = table_seq_start,
+	.next  = table_seq_next,
+	.stop  = table_seq_stop,
+	.show  = table_seq_show,
 };
 
-static int all_open(struct inode *inode, struct file *file)
+static struct seq_operations format2_seq_ops = {
+	.start = table_seq_start,
+	.next  = table_seq_next,
+	.stop  = table_seq_stop,
+	.show  = table_seq_show,
+};
+
+static struct seq_operations format3_seq_ops = {
+	.start = table_seq_start,
+	.next  = table_seq_next,
+	.stop  = table_seq_stop,
+	.show  = table_seq_show,
+};
+
+static const struct file_operations format1_fops;
+static const struct file_operations format2_fops;
+static const struct file_operations format3_fops;
+
+static int table_open(struct inode *inode, struct file *file)
 {
 	struct seq_file *seq;
-	int ret;
+	int ret = -1;
+
+	if (file->f_op == &format1_fops)
+		ret = seq_open(file, &format1_seq_ops);
+	else if (file->f_op == &format2_fops)
+		ret = seq_open(file, &format2_seq_ops);
+	else if (file->f_op == &format3_fops)
+		ret = seq_open(file, &format3_seq_ops);
 
-	ret = seq_open(file, &all_seq_ops);
 	if (ret)
 		return ret;
 
 	seq = file->private_data;
-	seq->private = inode->i_private;
-
+	seq->private = inode->i_private; /* the dlm_ls */
 	return 0;
 }
 
-static const struct file_operations all_fops = {
+static const struct file_operations format1_fops = {
+	.owner   = THIS_MODULE,
+	.open    = table_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release
+};
+
+static const struct file_operations format2_fops = {
+	.owner   = THIS_MODULE,
+	.open    = table_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = seq_release
+};
+
+static const struct file_operations format3_fops = {
 	.owner   = THIS_MODULE,
-	.open    = all_open,
+	.open    = table_open,
 	.read    = seq_read,
 	.llseek  = seq_lseek,
 	.release = seq_release
@@ -689,7 +667,7 @@ int dlm_create_debug_file(struct dlm_ls *ls)
 						      S_IFREG | S_IRUGO,
 						      dlm_root,
 						      ls,
-						      &rsb_fops);
+						      &format1_fops);
 	if (!ls->ls_debug_rsb_dentry)
 		goto fail;
 
@@ -702,7 +680,7 @@ int dlm_create_debug_file(struct dlm_ls *ls)
 							S_IFREG | S_IRUGO,
 							dlm_root,
 							ls,
-							&locks_fops);
+							&format2_fops);
 	if (!ls->ls_debug_locks_dentry)
 		goto fail;
 
@@ -715,7 +693,7 @@ int dlm_create_debug_file(struct dlm_ls *ls)
 						      S_IFREG | S_IRUGO,
 						      dlm_root,
 						      ls,
-						      &all_fops);
+						      &format3_fops);
 	if (!ls->ls_debug_all_dentry)
 		goto fail;
 

fs/dlm/dlm_internal.h

@@ -105,7 +105,7 @@ struct dlm_dirtable {
 struct dlm_rsbtable {
 	struct list_head	list;
 	struct list_head	toss;
-	rwlock_t		lock;
+	spinlock_t		lock;
 };
 
 struct dlm_lkbtable {

fs/dlm/lock.c

@@ -412,9 +412,9 @@ static int search_rsb(struct dlm_ls *ls, char *name, int len, int b,
 		      unsigned int flags, struct dlm_rsb **r_ret)
 {
 	int error;
-	write_lock(&ls->ls_rsbtbl[b].lock);
+	spin_lock(&ls->ls_rsbtbl[b].lock);
 	error = _search_rsb(ls, name, len, b, flags, r_ret);
-	write_unlock(&ls->ls_rsbtbl[b].lock);
+	spin_unlock(&ls->ls_rsbtbl[b].lock);
 	return error;
 }
 
@@ -478,16 +478,16 @@ static int find_rsb(struct dlm_ls *ls, char *name, int namelen,
 		r->res_nodeid = nodeid;
 	}
 
-	write_lock(&ls->ls_rsbtbl[bucket].lock);
+	spin_lock(&ls->ls_rsbtbl[bucket].lock);
 	error = _search_rsb(ls, name, namelen, bucket, 0, &tmp);
 	if (!error) {
-		write_unlock(&ls->ls_rsbtbl[bucket].lock);
+		spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 		dlm_free_rsb(r);
 		r = tmp;
 		goto out;
 	}
 	list_add(&r->res_hashchain, &ls->ls_rsbtbl[bucket].list);
-	write_unlock(&ls->ls_rsbtbl[bucket].lock);
+	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 	error = 0;
  out:
 	*r_ret = r;
@@ -530,9 +530,9 @@ static void put_rsb(struct dlm_rsb *r)
 	struct dlm_ls *ls = r->res_ls;
 	uint32_t bucket = r->res_bucket;
 
-	write_lock(&ls->ls_rsbtbl[bucket].lock);
+	spin_lock(&ls->ls_rsbtbl[bucket].lock);
 	kref_put(&r->res_ref, toss_rsb);
-	write_unlock(&ls->ls_rsbtbl[bucket].lock);
+	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 }
 
 void dlm_put_rsb(struct dlm_rsb *r)
@@ -967,7 +967,7 @@ static int shrink_bucket(struct dlm_ls *ls, int b)
 
 	for (;;) {
 		found = 0;
-		write_lock(&ls->ls_rsbtbl[b].lock);
+		spin_lock(&ls->ls_rsbtbl[b].lock);
 		list_for_each_entry_reverse(r, &ls->ls_rsbtbl[b].toss,
 					    res_hashchain) {
 			if (!time_after_eq(jiffies, r->res_toss_time +
@@ -978,20 +978,20 @@ static int shrink_bucket(struct dlm_ls *ls, int b)
 		}
 
 		if (!found) {
-			write_unlock(&ls->ls_rsbtbl[b].lock);
+			spin_unlock(&ls->ls_rsbtbl[b].lock);
 			break;
 		}
 
 		if (kref_put(&r->res_ref, kill_rsb)) {
 			list_del(&r->res_hashchain);
-			write_unlock(&ls->ls_rsbtbl[b].lock);
+			spin_unlock(&ls->ls_rsbtbl[b].lock);
 
 			if (is_master(r))
 				dir_remove(r);
 			dlm_free_rsb(r);
 			count++;
 		} else {
-			write_unlock(&ls->ls_rsbtbl[b].lock);
+			spin_unlock(&ls->ls_rsbtbl[b].lock);
 			log_error(ls, "tossed rsb in use %s", r->res_name);
 		}
 	}
@@ -4224,7 +4224,7 @@ static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
 {
 	struct dlm_rsb *r, *r_ret = NULL;
 
-	read_lock(&ls->ls_rsbtbl[bucket].lock);
+	spin_lock(&ls->ls_rsbtbl[bucket].lock);
 	list_for_each_entry(r, &ls->ls_rsbtbl[bucket].list, res_hashchain) {
 		if (!rsb_flag(r, RSB_LOCKS_PURGED))
 			continue;
@@ -4233,7 +4233,7 @@ static struct dlm_rsb *find_purged_rsb(struct dlm_ls *ls, int bucket)
 		r_ret = r;
 		break;
 	}
-	read_unlock(&ls->ls_rsbtbl[bucket].lock);
+	spin_unlock(&ls->ls_rsbtbl[bucket].lock);
 	return r_ret;
 }
 

fs/dlm/lockspace.c

@@ -464,7 +464,7 @@ static int new_lockspace(char *name, int namelen, void **lockspace,
 	for (i = 0; i < size; i++) {
 		INIT_LIST_HEAD(&ls->ls_rsbtbl[i].list);
 		INIT_LIST_HEAD(&ls->ls_rsbtbl[i].toss);
-		rwlock_init(&ls->ls_rsbtbl[i].lock);
+		spin_lock_init(&ls->ls_rsbtbl[i].lock);
 	}
 
 	size = dlm_config.ci_lkbtbl_size;

fs/dlm/recover.c

@@ -726,7 +726,7 @@ int dlm_create_root_list(struct dlm_ls *ls)
 	}
 
 	for (i = 0; i < ls->ls_rsbtbl_size; i++) {
-		read_lock(&ls->ls_rsbtbl[i].lock);
+		spin_lock(&ls->ls_rsbtbl[i].lock);
 		list_for_each_entry(r, &ls->ls_rsbtbl[i].list, res_hashchain) {
 			list_add(&r->res_root_list, &ls->ls_root_list);
 			dlm_hold_rsb(r);
@@ -737,7 +737,7 @@ int dlm_create_root_list(struct dlm_ls *ls)
 		   but no other recovery steps should do anything with them. */
 
 		if (dlm_no_directory(ls)) {
-			read_unlock(&ls->ls_rsbtbl[i].lock);
+			spin_unlock(&ls->ls_rsbtbl[i].lock);
 			continue;
 		}
 
@@ -745,7 +745,7 @@ int dlm_create_root_list(struct dlm_ls *ls)
 			list_add(&r->res_root_list, &ls->ls_root_list);
 			dlm_hold_rsb(r);
 		}
-		read_unlock(&ls->ls_rsbtbl[i].lock);
+		spin_unlock(&ls->ls_rsbtbl[i].lock);
 	}
  out:
 	up_write(&ls->ls_root_sem);
@@ -775,7 +775,7 @@ void dlm_clear_toss_list(struct dlm_ls *ls)
 	int i;
 
 	for (i = 0; i < ls->ls_rsbtbl_size; i++) {
-		write_lock(&ls->ls_rsbtbl[i].lock);
+		spin_lock(&ls->ls_rsbtbl[i].lock);
 		list_for_each_entry_safe(r, safe, &ls->ls_rsbtbl[i].toss,
 					 res_hashchain) {
 			if (dlm_no_directory(ls) || !is_master(r)) {
@@ -783,7 +783,7 @@ void dlm_clear_toss_list(struct dlm_ls *ls)
 				dlm_free_rsb(r);
 			}
 		}
-		write_unlock(&ls->ls_rsbtbl[i].lock);
+		spin_unlock(&ls->ls_rsbtbl[i].lock);
 	}
 }